Essay on Racial Inequality in America - 856 Words

In today’s world, the American still has barriers to overcome in the matter of racial equality. Whether it is being passed over for a promotion at the job or being underpaid, some people have to deal with unfair practice that would prevent someone of color or the opposite sex from having equal opportunity at the job. In 2004, Dukes vs. Wal-Mart Stores Incorporation was a civil rights class-action suite that ruled in favor of the women who worked and did not received promotions, pay and certain job assignments. This proves that some corporations ignore the 1964 Civil Rights Act, which protects workers from discrimination based on sex, race, religion or national origin. In the past, it is true that African American have suffered injustice,†¦show more content†¦Ã¢â‚¬Å"Some employers used tests for hiring or promotion that screened out African American at a higher rate than white applicants, making it nearly impossible for them to be hired in any substantial numbers† (Vertreace, 2010). In many cases white supervisors or managers would make sure they interview just enough minorities so they want to appear not to be bias toward other races. They even pretend to follow company’s rules, but instead they make their own rules and dare someone to cross them. Nevertheless, there are not enough opportunities for black people to advance. If the only available jobs are low-income jobs, then the chance of living in poverty will continue for minorities. In another sense, there are other minorities who have suffered a great deal due inequality in America. That would be the Hispanic culture, who will do most work other culture refuse to do for less pay. Some Mexican who comes from parts of Mexico that is so poor that they are willingly and ready to work for almost nothing. Many of them work here in the United States illegally, picking tomatoes or other crops. Although they earn less than the minimum wage, it is better than earning nothing back home. While it is true that Mexican immigrants worked very hard, it does not necessary mean that they should be subject to work for a very low wage. Above all, they work long hours in the hot beaming sun, until their skin turns three shades darker than it was before theyShow MoreRelatedCauses Of Racial Inequality In America1777 Words   |  8 Pages Racial inequality is one of the acute issues faced by contemporary American society. In many academic sources, this social issue is discussed by so ciologists as a serious national problem that requires the proper and prompt solutions (Hwang, J. Sampson, 2014; McCarthy, 1991; Williams Sternthal, 2010). It has been found that â€Å"race relations in America have undergone fundamental changes in recent years, so much so that now the life chances of individual blacks have more to do with their economicRead MoreRace And Health Inequality In America. . 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However, the truth is that racial groups have been segregated by the white-centric media or government of the American society, and that has widened the psychological and geographical distances between the two groups, Asian and black, and has encouraged ignorance andRead MoreThe Effects Of Islamophobia On The Past And Present1326 Words   |  6 Pagessocial inequality in the past or present lead to chaotic consequences. Individual freedom of begin equal among started to vanish. Islamophobia began when the 9/11 terrorist attack occurred. After the 9/11 attack the development of the fear of Islamophobia began. In September 11, 2001, there was a terrorist attack and that took down the Twin Towers (Holman Silver, 2011, p. 483). Thus, this is a point of significant because this was the beginning of the major crisis of Islamophobia in America. 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Race is not defined by the way an individual behaves or portrays themselfes; itRead MoreInequality Of The American Dream1368 Words   |  6 PagesInequality Do you think the American dream is still a concept today? If so, is it still possible to achieve this American dream? The American dream can be described as the success of life, and the goals achieved. Sometimes, these dreams can not be achieved due to obstacles. In this case, obstacles such as inequality. Many may view America has the land of opportunity and the greatest nation ever due to our vast diversity and freedom, but is this thought to be true in America itself? There has beenRead MoreSocial Inequality Is An Important Issue In Today’S Society.1595 Words   |  7 Pages â€Æ' Social inequality is an important issue in today’s society. Today, people face many inequalities based on their gender, race, religion, and disability status, yet there are many different ideologies and ongoing debate about social inequality. There are three perspectives concerning the issue of inequality in America. This paper will analyze an article about social inequality, â€Å"Gender, Race, and Income Gaps† by Richard Hogan and Carolyn Perrucci, and how it applies to the viewpoints concerningRead MoreAmerica Still Divided : Racism And Discrimination1091 Words   |  5 Pages Soc206 April 30, 2015 Final/Research Paper America Still Divided Racism and discrimination inequalities have become a major discussion throughout the years in our society. Inequalities has impacted every level of humanity on this earth. Education, tolerance and acceptance can be used to challenge one another in attempt to change the negative traditions that continue to exist in our culture. Racism and discrimination inequalities continues to be passed from generation to generation.

Hobbes, Locke and Rousseau on Classic Liberalism - 1091 Words

Everyone has their own very unique views on everything in the world. What’s right and what’s wrong is a good example of how humanity views different subjects let’s say a man kills another man to protect his family from harm he may see it as okay to do but in the bible it says â€Å"thou shall should not kill† so it’s all how you look at it. In this paper I will be discussing the different view point of Hobbes, Locke, and Rousseau on the most basic tenets of classical liberalism. For example the states of nature, the social contracts, and the sets of view of the rights and obligations of citizens and states. My first topic that I will be discussing is the different views of social contracts. It will go in order from Hobbes to Locke then to Rousseau. As I was pointing out in the intro I will be starting off with Hobbes perspective of social contract. Hobbes believes in a â€Å"civil society† which is humanity’s natural state that is ran by fear and ever-present insecurity. There is always a solution to every problem with this problem the solution is to go to war then see the fear of the society and their insecurities of that war, then the government using their reason to discover ways out of the conflict thus ending the war. Hobbes pretty much sums this up by saying â€Å"agreeing to end the war†. He says that â€Å"They come to see the fear and insecurity of their persons and possessions in the state of nature as undesirable, and peace and order as desirable.† Which means that they rejectShow MoreRelatedJohn Locke: Founding Father of Modern Era Liberalism1444 Words   |  6 PagesThomas Hobbes, Jean-Jacques Rousseau, and John Locke are all great thinkers who were greatly influential in forming phil osophies that would affect the future of politics. By analyzing each philosopher’s ideology, we can identify which thinker’s theory reflected modern era liberalism the most. For this paper I will be arguing that, John Locke provides a more compelling framework of modern era liberalism because of his perception of the state of nature, the social contract and the function of governmentRead MoreThe Social Contract Theory Since The United States1449 Words   |  6 Pagesthe point clear in two senses. First, the Framers of the Constitution realized the notion of social contract as the very nature of being a nation-state as emerged in the thinking of modern philosophers like Thomas Hobbes (1588-1679), John Locke (1632-1704), and Jean-Jacques Rousseau (1712-1778). In such contract, the people are the subject tough they do not directly involve in the process. Second, the word „weâ€Å" poses the meaning of democracy as the government ruled by the people (Greece, demos :Read MoreLiberal Perspective of a State7979 Words   |  32 PagesINTRODUCTION Liberalism has meant many things over the last 400 years and has provided significant benefits to the human race. Basically, liberalism is the belief in the importance of liberty and equal rights and so, the main theme of liberalism throughout the period of its development was that the purpose of state is the promotion and protection of human freedom and equality and ensuring of human happiness. Liberalism meant the removal of traditional distinctions that were imposed on people. Read MoreThe Contributions Of John Rawls Essay5959 Words   |  24 Pagesjustification to the use of coercive power by the state as it would take a form where the citizens under the conditions of freedom, give there give their consent. This theory is called Justice as fairness. THE ORIGINAL POSITION Like Locke, Hobbes, Kant and Rousseau, John Rawls also belongs to the social contract tradition where persons’ moral and/or political obligation help them to follow the provisions or agreements of a contract which states the duties and rights of the people in a civil societyRead MoreOrganisational Theory230255 Words   |  922 Pagesof organizations. The authors’ sound scholarship and transparent style of writing set the book apart, making it an ingenious read which invites reflexivity, criticalness and plurality of opinion from the audience. This is a book that will become a classic in organization studies. Mihaela L. Kelemen, Professor of Management Studies, Keele University, UK An unusually rich and deep philosophical book on organization theory with several new thinkers and ideas. Pedagogically a well-structured book with

The Myth of Sisyphus free essay sample

The Myth of Sisyphus In the essay of â€Å"The Myth of Sisyphus† Albert Camus suggests that there is a possibility that there is no real meaning to life and that as humans, it is a pointless gesture to go looking for this religious or universal meaning. Camus uses Sisyphus as his prime example of this. Sisyphus, a punished human for â€Å"certain levity in regard to the gods† has to do a pointless task of pushing a rock up a hill repeatedly. This punishment itself reflects the ideas of the absurd. Camus believes that death is at the end of every person’s life but people still go on looking for this purpose but it is pointless because the people all end up the same, dead, but the pursuit of the purpose can possibly hold meaning. Sisyphus along his endless task finds sadness and joy. According to Camus there’s no sun without shadow which is that there is no joy without pain. We will write a custom essay sample on The Myth of Sisyphus or any similar topic specifically for you Do Not WasteYour Time HIRE WRITER Only 13.90 / page Camus proposes that Sisyphus is happy when he acknowledges his consequences, the pain of what his life has come down to and accepts his fate. Individuals often try to comprehend and answer the question â€Å"What is our purpose in life? † and fail to speak out because they are constantly puzzled about what their purpose is in life, and so is Sisyphus. Sisyphus is constantly trying to find hope or meaning in his task, but he cannot find a meaning for his existence. The fate of Sisyphus’ is settled for eternity and until Sisyphus pushes the rock forward and up the hill, his purpose for that is just to roll the rock. Sisyphus small amount of hope keeps him content that he is able to have a solid purpose that he can see and feel the rock even though in the end of the task it is meaningless as the rock will drop back down the hill. I disagree with Camus’ view that there is no real meaning to life because, as a young Christian at an Evangelistic Church, to know God and enjoy him forever is the meaning of life. The reason this is the meaning of life is because God created us that way. God created a beautiful world and put humanity in it to live and prosper, but overall to have a relationship ith him. This was the purpose of our creation. We are most happy, fulfilled and complete when we are worshiping and being in a relationship with our Lord. By ignoring God and not having that relationship with him is a sin. Having that sin in your live is what makes your live less than what they could be. People live outside in the cold when God wants them to come into his house and live with him. It is the n when we turn back to God and stop ignoring him what he will find true happiness and fulfillment. Our role in this world is to seek out and encourage one another in love and walking in faith. This modern world is so focused on individualism that being part of and serving in a community loses its path leading people to feel alone. Our lives today are to live in a way that we serve God and the people he has put in our community. Camus believed that life was pointless because no matter what accomplishments you achieved you would die and that will be the end of them, but it’s not like that. God holds us responsible for our failure. Jesus teaches about a time in the future when we will all have to come before God in judgment and face the consequences for the way we have lived. If you confess with your mouth that Jesus is Lord and believe in your heart that God raised him from the dead, you’ll be saved and that will be your purpose for living. Camus’ introduced the option that life is meaningless by interpreting the idea of absurdity and how giving meaning to life in ways such as religiously, is inevitably pointless because in the end death is terminal. Camus’ suggests that happiness arises from absurdity when one learns and accepts death. Sisyphus is a happy man because he was able to come to terms with his punishment although it had to be eternal. Unlike, Camus’ idea being able to believe that the more you grow in your understanding of what God has done in your live, the more you will want others to know about it, and how God can change their lives for the better. As you relate to God, and live according to his direction, others will notice a difference in you. God has given us the great opportunity of sharing his love with others.

Oedipus the King

Introduction This is an Athenian tragedy by Sophocles. The main character Oedipus is the King of Thebes. Oedipus’ own fault brings him down and in an embarrassing way. The literature work presents a perfect example of tragedy. King Oedipus is the protagonist in the play. His tragic error is linked to a natural curse on his biological father.Advertising We will write a custom essay sample on Oedipus the King specifically for you for only $16.05 $11/page Learn More Analysis of the tragic error The chronology of events begins when a young man learns about a rumor that King Polybus and Queen Merope are not his biological parents. Innocently, Oedipus sets out on a journey with the intention of permanently moving away to thwart the Oracle, which is unknown to him. Oedipus feels that if he is far away then he may not harm his foster parents whom he now believes are his biological parents. The first part of his tragic error occurs during this journey. Oed ipus meets a stranger, who unknown to him is his biological father, Laius. A quarrel ensues which eventually leads to a fight. By the end of the war, Oedipus kills everybody except one person in the stranger’s entourage (Storr, 2008)). The cause of disagreement was a very simple argument between them over who had the right-of-way. All This takes place while the two, King Laius and his Son Oedipus are unaware of their identities. Oedipus did not even know that the stranger he was fighting was a King. The second part of King Oedipus tragic error, ironically occurs after Oedipus uses his wisdom to free the Kingdom of Thebes. It is interesting to see how wisdom and the wish to rescue Thebes drive Oedipus into a classic tragedy. Oedipus answers the riddle from Sphinx to deliver the Kingdom of Thebes from a curse.† What is the creature that walks on four in the morning walks on two at noon and walks on three in the evening?† The Sphinx asked,  ´ Man,† Oedipus re sponded. The reward for this work was for Oedipus to be made the King of Thebes. He was then given the Queen of Thebes, Jocasta, to marry. The Queen incidentally was his biological mother. This opens both ends of the tragic error. The Oracle he ran away from was then fulfilled. Oedipus is a victim of fate, killing his father and his mother. The order of events is guided by his brilliance in which Oedipus attempt to unravel the truth. This is in addition to control his destiny .This however, climaxes into the tragedy that leads to his embarrassing downfall.Advertising Looking for essay on art and design? Let's see if we can help you! Get your first paper with 15% OFF Learn More When he discovers that he has a curse following him, just like ant other human being and King for that matter, sends Creon his brother-in-law to seek advice from Apollo. â€Å"King Apollo! May his joyous looks be presage of the joyous news he brings!† He says. The news from Apollo seems to bring the expected joy and hope. Creon, â€Å"Good news, for even intolerable ills. Finding right issue, tend to naught but good.† Creon explains that evasion will only come after the murderer of Laius; the former King is found and prosecuted. With determination to avert his curse, Oedipus commits himself to apprehend the murderer and make sure justice is done. Ironically, Oedipus is the killer himself. Further complications arise when Jocasta disapproves the blind prophet’s prophesy that King Oedipus killed the former King Laius. The news from the prophet is in fact true but a mystery to understand. Jocasta advises Oedipus not to be bothered by looking for the murderer. She says who the man is. Let it be. Twere wastes of thought to weigh such idle words.† However, Oedipus is not convinced and insists to pursue the matter. However, an obscurity in itself regenerates in Oedipus memory regarding a babyhood story of him being an adopted youngster. Jocasta’s flow of the story looked very similar to the one the old man told him in his childhood. Members of his Kingdom through the song continue to persuade him further but he resists (Storr, 2008) He continues his probe to know the murderer of Laius, the former King. The fatal chronology of events fulfills the prophesy of the tragic error when Jocasta discovers that her second husband is actually her son and a child whom together her first husband King Laius dumped in the forest to avert a curse. To her surprise the child was a live, a King and worst of all her husband whom they had four children together. With glaring in her face and because the situation then was an abomination, Queen Jocasta kills herself by committing suicide. This happens shortly before King Oedipus also discovers the truth. Oedipus realizes that he in deed killed King Laius, his biological father that he was married to his biological mother, and together they have four children (Grene, 2010). The events of the situat ion become unbearable. Oedipus, in accepting his mistake requests for punishment. He ends up being a beggar who wanders all over. The moral lessons Athenians learnt a lot from the tragic error by their King, Oedipus. Among the lessons, the Athenians learnt that destiny could never be thwarted. Oedipus in quest to know the truth and his wish to control his destiny ended disastrously. His father, Laius and his mother Jocasta conspired to kill their son in an attempt to evade destiny.Advertising We will write a custom essay sample on Oedipus the King specifically for you for only $16.05 $11/page Learn More This never worked as Oedipus was eventually rescued and he lived to fulfill what fate dictated. The curse that turned to be fate for the generations was brought by Laius’ moral decadence. In his youth, he raped a young woman he was teaching. Rape is a vice that is not condoned by the society. This was the source of the curse. The two Kings, Laius, and Oedipus, tried to thwart it but never succeeded. The Athenians learnt that destiny has its mechanisms of ensuring that it is never avoided. Their King had sort advice from Apollo in trying to avoid a terrible curse that had befallen him. The response circumvented things back to King without his knowledge. Oedipus, then on following up the matter destroyed himself (Berg, 2011). It was clear to them that if something were predestined to happen, it will happen no matter what takes place. Athenians believed in the fulfillment of prophesy. The tragic events of their King, Oedipus simply reinforced their belief. Their two Kings should have believed in fate. To the Athenians it would never have come in such a torturous way. King Laius and Queen Jocasta would not have conspired to kill their son. This means that King Polybus and Queen Merope would never have brought up Oedipus. This would have reorganized the way fate would have happened. Most important being that Oedipus would never h ave bothered to unravel the mystery of his birth. When the Athenians analyzed the order of events through the tragic error by King Oedipus, it was clear that the cause was an immoral behavior. Laius had been offered an opportunity to tutor a young woman. Laius forgot the good reception he had been given, he instead of concentrating on his job became immoral. The society and especially in Athena upheld morals. The whole tragedy would have been avoided at the tiptop. It would be easy for Laius to uphold simple but important ethics than letting the entire generation go through pain and embarrassment. Application In comparison with the modern world, there is great difference in the beliefs and a change between that generation and the current one. In the modern world, leadership is learnt and the leaders do not run their countries alone. Decisions are never unilateral, to am extent that even the foreign nations influence internal affairs of other countries. Forms of leadership have also changed. Analysis of those seeking leadership including their history are done.Advertising Looking for essay on art and design? Let's see if we can help you! Get your first paper with 15% OFF Learn More Religion also plays a great role in the difference. Though religion existed in the Athena, the difference is in the faith. The judicial system takes the opportunity to rehabilitate those with moral decadence. Laius would have been jailed for rape. He would never have had a chance to rule since his behavior would never allow him. In the modern society, Hitler, the former Chancellor of Germany represents a leader with a tragic error. He started the Second World War and died a painful and embarrassing death. References Berg, S. (2011). Oedipus the King. New York: Oxford University press. Grene, D. (2010). Oedipus the King by Sophocles. Chicago: University of Chicago press. Storr, S (2008). Oedipus the King: Original play. New York: Internet classic commentary. This essay on Oedipus the King was written and submitted by user Grayson Carson to help you with your own studies. You are free to use it for research and reference purposes in order to write your own paper; however, you must cite it accordingly. You can donate your paper here. Oedipus the King Table of Contents Introduction Man versus man conflict Man versus nature Man versus himself Conclusion Works Cited Introduction ‘Oedipus the King’ is a play written by Sophocles in Ancient Greek at around 430 B.C. set in a fabulous past of the ancient Greek. Throughout the play, the king is determined to understand several issues about the community and himself.Advertising We will write a custom essay sample on Oedipus the King specifically for you for only $16.05 $11/page Learn More As a result, he seeks help from the Theban chorus; Tiresias, the blind prophet; Creon, his brother in-law; Jocasta, the Oedipus wife and the shepherd. Throughout the play, conflict stands out as the main theme as exposited by exploring the three elements of conflict from the play viz. man versus man, man versus himself and man versus nature. Man versus man conflict A conflict exists between the king and the prophet Tiresias. The play begins by investigation into the cause of death of Laius, the former Theban king. When the Oedipus King seeks advice from the prophet Tiresias, to his surprise, the prophet tells him that Oedipus was responsible for the murderer of Laius. In disbelief, the King becomes annoyed with Tiresias and they end up into a heated argument. The king blames the prophet for accusing him for the murder (Sophocles 306). While the King maintains his innocence, Tiresias holds that the murderer of Laius is a Theban citizen whom they have a blood relationship. The manner in which Tiresias leaves the palace evidences unhidden conflict between him and the Oedipus King. In addition, the king is in conflict with his brother in-law, Creon. When the prophet accuses Oedipus for the murder, the king blames Creon for masterminding the accusations. The king believes that Creon is determined to undermine him. As a result, the king calls for Creon’s execution. Another conflict exists between Jocasta and the prophets. Jocasta beli eves that prophets are liars and the king should take none of their advice. â€Å"Listen and I’ll convince thee that no truth in these prophets† (Sophocles 316). This quote reveals that Jocasta does not believe in prophets any more. There is also conflict between the king and the shepherd. When the shepherd refuses to give information on murder, the king threatens to execute him. Man versus nature Theban community is in conflict with nature. Oedipus king is determined to fight the plague, which has affected the community. As Sophocles indicates in the Creon’s conversation with the king, the leadership of Theban community is investigating the cause of the plague: â€Å"Let me report then all what god declared.Advertising Looking for essay on literature languages? Let's see if we can help you! Get your first paper with 15% OFF Learn More King Phoebus bids us straightly extirpate Fell pollution that infests the land, and no more harbor an inveterate sore† (Sophocles 315). From this quotation, it is clear that the people of Theban are determined to fight to the end the plague that runs through the community. As illustrated on the first scene, the priest and the Theban choir have also visited the palace to seek aid for the plague. The king gives them hope by noting that â€Å"but I grieve at once both for the general, myself and you† (Sophocles 267). To grieve in ancient Greek meant cooperation with the suffering. Plague is a natural disease and therefore fighting it evidences this kind of conflict. Man versus himself The king is in conflict with himself. The community expects exemplary behavior from their king, especially in such ancient setting. As the play illustrates, the king killed his father and slept with his mother. The king’s behavior is in conflict with the character of Oedipus king. It is therefore vivid that the king is in conflict with himself. The shepherd is also in conflict with himself. Once requested to come and testify on the murder of Laius, he agrees and in fact provides some information to the king; however, after sometime, he begs to leave without further questions (Sophocles 300). This illustrates the shepherd’s conflict with himself. Conclusion The major conflict arises when the prophet accuses the Oedipus for the murder of the former king. Since the entire play revolves about the murder, it is therefore justifiable that conflict is the major theme in the play ‘Oedipus the King’. King’s conflict with the prophet and Creon illustrates man versus man conflict while the community’s battle with the plague evidences the man versus nature conflict. The king’s behavior is in conflict with what is expected of him thus underscoring the man versus man conflict. Works Cited Sophocles. â€Å"Oedipus the King.† The Collection. Trans. Francis Storr. Chicago: University of Chicago Press, 1912. This essay on Oedipus the King was written and submitted by user Nylah U. to help you with your own studies. You are free to use it for research and reference purposes in order to write your own paper; however, you must cite it accordingly. You can donate your paper here. Oedipus the King There is a variety of elements of drama that writers can choose from, when writing their works. These elements include theme, plot, characters, and language among others. In Oedipus the King, Sophocles uses the element of theme to produce a thrilling composition. The three important themes here include the power of conventional law, disposition to disregard the truth and confines of free will.Advertising We will write a custom essay sample on Oedipus the King specifically for you for only $16.05 $11/page Learn More Themes Sophocles uses the theme of power of conventional law. The need to bury the dead surpasses any law regardless of how the dead person was evil or unpopular. This comes out clearly for Creon after assuming power in Thebes. After losing his power to Creon, Polynices dies. Unfortunately, Creon being the king commands that Polynices corpse be left unburied for dogs and birds to feed on him and everyone; who had been wronged by this wicked ma n, see him. (Sophocles 98). Because Polynices was a wicked man, Creon assumes this fact justifies his acts. It is true that Polynices had insulted everything and everyone including religion and power. However, as the play unfolds, the audience realizes that burying the dead is not tied to state rules and it has nothing to do with citizenship and loyalty, but has everything to do with humanity. Creon comes to learn, though late; that, the rotting body of Polynices was more of lewdness than punishment. Even though there was no written law in Greece customs to bury the dead, the conventional laws, tied to humanity had power over the state. Again, Sophocles shows how people have the disposition to disregard the truth. Even though Oedipus knows the truth concerning Laius’s murder, he does all he can to exculpate himself. Oedipus knows very clearly that he killed Laius single-handedly; however, he is clinging to the side of the story that claims that Laius died in the hands of st rangers. On the same basis, Oedipus chooses to ignore the oracle while Jocasta overlooks the fact that her son was to kill her husband. Oedipus knows this very well but in an attempt to feel good they deliberately choose to ignore the truth. The ironical part of this part notwithstanding; the audience cannot fail to see the vehement denial of truth. People have eyes; they see but choose not to acknowledge and accept the truth. Finally, freewill has limits and this comes out clearly in this story. Prophecy and oracles were respected amongst Greek people during this era. This same oracle had predicted that Oedipus was going to murder his own father and take his mother to bed. On the other hand, prophecy had let Jocasta know that her son would kill her husband and sleep with her. Advertising Looking for essay on art and design? Let's see if we can help you! Get your first paper with 15% OFF Learn More As events unravel, it is clear to Oedipus that he is that boy talked o f in Jocasta’s story; however, he cannot use his freewill to change things. Things have gone out of hand such that, they cannot be restored; not even by freewill. Conclusion Sophocles employs the element of theme to communicate with the audience. The theme of this story was to address issues that were affecting the people of Thebes during this time and even in times to come. The audience can easily know what Sophocles meant by writing this script. This is because even as the audience looks back in real life, the issues addressed here are easy to identify with in the society today. These are not foreign events happening to Oedipus only; no, they are happening in real life, right under the watch of the audience. This element of drama comes out strongly and makes the play compelling. Works Cited Sophocles. â€Å"Oedipus the King.† Berg, Stephen Clay, Diskin. Ed. New York: Oxford University Press, 1978. This essay on Oedipus the King was written and submitted by user Eugene L. to help you with your own studies. You are free to use it for research and reference purposes in order to write your own paper; however, you must cite it accordingly. You can donate your paper here.

History of Hong Kong Report essays

History of Hong Kong Report essays "Tourism and the Hong Kong economy" is basically describing the relations between the tourism and economy in Hong Kong. There are many different resources can cause the influence on economy by tourism, such as, the export of services, industries, and policy etc. The present monograph introduces the issues, the source markets which how they affect the tourism. Also analysis of the economic impact of tourism and addresses the strategic importance of aviation industry and the airport capacity problem. Furthermore, the studies of the hotel industry are another key industry in the tourism sector. Also, the retail sector, and the building of new tourist attractions and the policy are all had been mentioned from the book. As the book state, a significant proportion of visitors to Hong Kong are business travelers, not tourists. Of course, Hong Kong has managed to attract visitors who come purely for pleasure. Exports provide a powerful stimulus for growth. Domestic demand is much less powerful in this regard. Basically, exports represent a direct injection of purchasing power into the economy. Without incomes earned from export, purchasing power has to come from within the economy. Also, the source markets can be affcting the tourism. The present institutional constraints on the inflow of China tourists, which is a complex issue. The consequence of direct air links between Taiwan and the People's Republic of China, which some people find worrisome, is expected to be slight for obvious reasons. The benefits of the convention business and the marketing concept of the integrated Pearl River Delta, which vastly expands the scope of tourist attractions to visitors' markets and the growing con vention business are two new aspects of the tourism industry that deserve mention. Hong Kong has always been well known for its openness to work drade. It has also captured a large share of the global revenue that international travel gen...

Going It Alone

Going It Alone For some reason, todays quote resonated with me. Whether introverted or extroverted, a writer has to feel comfortable being alone for hours and days on end. While we see lots of blog posts about how a writer needs his tribe or his team, the bottom line is he writes alone. Hes rejected alone. Hes accepted alone. Theres a tremendous amount of alone time in his career, and he has to accept, maybe even enjoy, that experience or he wont last long. All this alone time is probably why writers are indeed so introverted. We enjoy keeping company with ourselves, inside our thoughts. Its safer there. But that also explains why writers, when they venture out of their seclusion, tend to congregate with other writers. This is a trend that is helpful . . . only to a point. After that point, however, its detrimental. In case after case, I see writers pitching their books to other writers when they ought to be pursuing readers. Unless they write FOR writers, in how-to books, or their fiction is about a writer, they are not reaching their targeted audience. Writers are an incestuous lot. Conferences, promoting their books, chatting online. They gravitate to each other, but it becomes a habit because its so comfortable, and we tend to overdo it. And theres been a trend of late to host events where dozens of writers appear at a festival of sorts. Ive been invited to several of them. This is my opinion, keep in mind, but I see these events as not being very effective, possibly even handicapping or detrimental. At least depressing. And this is why: 1) Appearing with thirty or forty authors dilutes you, your voice, your work. The faces start to blur. Attendees remember you as part of a mass, not as you. 2) Attendees can only buy so many books. Lets say two books per attendee. Do the math. Thirty authors x 2 books per attendee = 60 attendees minimum. But lets say a productive day for you means ten books. That means 300 attendees minimum assuming one or two authors dont run away with the show. 3) Such events try to snare one or two well-known authors. Those names draw readers . . . to them, not you. Thats the name that will be remembered when the readers go home. Branding doesnt mean you and others. It means you. Dare to appear alone. Dare to promote yourself as unique, powerful, intriguing and worth reading. Embrace your aloneness. Theres nothing wrong with being alone. Like I preach to shy writers across the country, learn to love who you are. Be unique, be confident in your own skin. Because attempting to blend into dozens, even hundreds, of like souls will only make you fade into the masses. You are better than that.

Software Process Models Essay Example | Topics and Well Written Essays - 750 words

Software Process Models - Essay Example this scenario, the hospital will be using this information system to keep a record of the patient, such as their personal information, information regarding their disease and so on. The software development team has decided to adopt prototyping model for the development of this information system. This approach will allow the software development team to build a prototype of the system in order that the users of the system could identify the working of the proposed system. Basically, the majority of system analysts nowadays makes use of prototypes all the way through the system design. A prototype is a functioning model of the planned system (Whitten, Bentley, & Dittman, 2000; Shelly, Cashman, & Vermaat, 2005). The system analyst basically constructs a useful structure of the solution throughout the design. Prototyping allows the software development team to develop a functional system quickly and reasonably for end users to weigh up. By communicating with the prototype users can search out an improved suggestion of the information requirements. The prototype authorized by the users can be used as a model to build the ultimate system. In this scenario, the prototype can be acknowledged as a functioning adaptation of software or an element of the software, but it is intended to be no more than a development model. Additionally, once prepared, the prototype will be additionally developed until it obeys the rules accurately to user’s requirements. Once the design has been completed, the prototype can be transformed into a sophisticated development system. The method of developing a foundational design, making use of it, refining it and trying again has been acknowledged an iterative method of systems development for the reason that the steps essential to develop a system can be repetitive over and over again (Laudon & Laudon, 1999; Whitten, Bentley, & Dittman, 2000). In addition, prototyping is further openly iterative than the traditional life cycle, and it

Request For Proposal Assignment Example | Topics and Well Written Essays - 750 words

Request For Proposal - Assignment Example The identified company goes by the name Go Daddy taking the package on unlimited hosting space. Workers at the information technology department will be trained on ways of updating the website (Stephen, 2010). Our Company has worked with a number of nongovernmental organizations. Their websites are up and running while positive recommendations have been provided by the companies. The listings of the websites are the: The above websites were fully implemented by our company from design to provision of hosting services. The profile holds a mixture of nongovernmental, corporate and governmental websites. This makes our company to have wide experience in dealing with the wide global diverse clientele. Dealing with these clients leaves us being the best company of developing the European Union Website (Lydia, 2003). Our company has been in the business for 10 years specializing in design and implementation of web based systems. The company has grown from five employers to 50 employees in a period of two years. The number working in web site design is 30 people among the hundred workers within the company. Upon receiving this job we will dedicate ten of our best designer which will add to 10% of the company workforce to ensure timely delivery of the website. Our company is located in San Francisco city street 234 Zip 20300. The telephone number that can be used to contact us is 0100-2033-5567. The lines are open 24 hours a day for clients to make any enquiries (Dennis, 2007). The company will employ the prototype model in delivering the project to ensure its reliability and usability. The prototyping model will allow development of the first release of the website which is delivered to users to elicit their opinion on the website. Their opinion will be taken and included in the next release of the software which will be a half finished website with some of the functionalities fully working. The final prototype will

Attitudes Towards Women In World War II Essay Example for Free

Attitudes Towards Women In World War II Essay 1. Source C is written by a Historian, this means that she will have had a long time to gather together her facts, and write using a variety of sources. This will give the source more depth, and it could also include information from more than one source. However, it is written by a woman, who is commenting on the history of women, so it could therefore be slightly bias. This woman could be writing to prove a point, or get recognition for women (i. e. for a feminist movement). On the other hand, source D was a speech made by the Deputy Prime minister of Britain in 1942. It is highly likely that this speech would have been used as a form of propaganda in Britain to keep the moral of women up during the war. They needed to do this to encourage the women to sign up to work in the factories, as the men were away fighting on the battlefields. It is evident in the tone of the source that the government were falsely praising the women to keep them happy. It was a very dull job, and they were trying to make the work they did sound positive, preformed with dead accuracy by girls.. It is evident that in source C the author is analysing the source, and giving her opinion. Such derogatory remarks. It seems that she is giving a very opposed opinion to the magazine article she is commenting on, and all the information that this gives the reader is her opinion of they way women were portrayed at that time. Despite the fact that we do get some quotes from the source she is analysing, we are only given the selection she chooses, and she has chosen those particular parts to back up her opinion. It does appear that women were depicted during the Second World War as empty-headed frivolous creatures. However, this is only part of the source, and we cannot get the full picture, as the author has picked out certain parts to back up her opinion. The original might depict a different opinion, but we are unable to find that, as we are not given that here in source C. Source D gives us the impression that women were viewed as very skilled, and they could pick up things very quickly, precise engineering jobs would have made a skilled turners hair stand on end are preformed with dead accuracy by girls who had no industrial experience. However this seems very strange, because the general opinion by men during the Second World War was that women were un-skilled and should stay in the home, so it appears that the government were lying to women (i.e. propaganda) so that they could fill in the jobs for men when they were away. The speech was made at the peak of the war, and it would have been crucial that they had enough women to work in the factories. To summarise, I think that source C is more useful as evidence about attitudes towards women in the First World War, as it depicts a more realistic view of what people thought at the time. Women were viewed as insignificant, and more concerned about how they looked. Although it is a bias opinion from a female historian trying to back up her views, it does seem a more historically accurate. Source D could not be used as an accurate view, as it is government propaganda, purposely being used to keep the moral of women high. 2. Source G is being used as an advertisement for Female wardens, and Mrs Peeks pudding. It also seems to be being used to make men more comfortable with their wifes going into service. It appears to be a form of propaganda; therefore, it is less reliable as a source of information. The first window in the cartoon strip shows a man sitting at the table with his wife eating a meal. In most situations this would not be the case, as men were usually sent away to fight. This does appear to make the advert less accurate. This source shows that men only thought women were useful for putting the meal on the table, or at least it was their duty to do so. The husband in the first caption states cold dinner again! as if it was his wifes duty to provide him with a hot meal every night. The following caption quotes the wife saying oh dear, Ill have to resign from the post, I just cant get Jim a hot meal at night. Here we see that the woman is hanging on by every word that the man tells her, as if he was superior to her. This very much depicts the attitude that men had to their wives at that time. The last box on the cartoon strip quotes the man saying I guess youve resigned your job? here we find the man expecting the woman to drop everything that she does, so that she may be of service to him. The woman replies, Mrs Peek is looking after your dinner. Again we find the man being superior to the woman. I think that overall this source depicts well the attitude of men towards women in the Second World War. The man expects the woman to drop everything so that she may be of service to him, and that her job does not mean any thing, and the woman seems to agree with it as she knows no other. The only thing that makes the source less reliable is that it seems to be a form of propaganda. 3. When World War II came around, every man In Britain was encouraged to sign up to the forces, and fight for their country, or join some line of service. Originally only men had been asked to sign up, and it was out of the question to ask women to, as they had no skills in work, they were just useful around the home. However, it had not occurred to them that there was going to be a shortage of people to work on the farms, and in the factories when the men had left to go and fight. The government were left with no other option than get the women to fill in the spaces; the women were conductors on the buses taking over until the men came home again (source F) Before the war women had fought hard for equal rites, and when the war started it seemed like a great opportunity had opened up. Most women were happy to start with, but then they were treat badly, and they were most definitely not treat with the same respect men were. The people in the country were very resentful, they didnt make it easy for you, we werent really welcome. It was hard work for the women, they had been put into hard jobs with no training, but they seemed to manage it, preformed with dead accuracy by girls who had no industrial training. It was a new experience for women, and they had been launched straight into it unexpectedly. Before the war a lot of women were happy not to work, but due to the war, they were forced to sign up. This came as a shock to a lot of women. Source J is evidence of this, it shows a copy of an official government announcement to women stating: there must no longer be any doubt in anybodys mind that every available woman in Britain will have to serve to win this war. It wasnt a decision they could make themselves any more, it was a duty to their country. Despite all of the new opportunities that had been given to women, after the war the men started coming back, and they took back their jobs too. The end o this war brought many unheard and undreamt changes. All of the opportunities they had been given had been taken away from them, and it became clear to women that they had only been there to fill in the gaps when the men were away fighting. At first, the war seemed a great opportunity for women to get recognition, and they thought that they had eventually earned what they were fighting for. However they soon realised that they were just there to fill in the space of the men, and when the men got back, they were pushed out of the jobs. It did bring about changes for them at first, but only during the war. When the war was over, everything went back as it had originally been, however, it had made people realise that women were actually capable of doing the work that the men did, and it opened a lot of paths for the future.

Career Summary Of A Dietician Essay -- essays research papers

RESEARCH & FACTS The career I researched was that of a dietician. Someone who wishes to become a dietician must first obtain a bachelor’s degree, which would be considered a minimal requirement. Most dieticians will tell you that it would be within the best interests of a student wishing to become a dietician to get a master’s degree. Dieticians must have a love for science (chemistry in particular) and algebra as these skills are practiced routinely in the profession. It would also be a good idea for someone wishing to become a dietician to take some kind of accounting or book-keeping class, as dieticians must work on and file multiple records for each of their patients.   Ã‚  Ã‚  Ã‚  Ã‚  To become a dietician you must be willing to research every day. New scientific breakthroughs are made on a regular basis that are constantly changing the shape of the practice. Dieticians must also be willing to regularly meet with patients and physicians to accurately determine if their current dietary plan is working or not and what steps they should take to reach their final goal. Hospital dieticians correspond with the kitchen staff to make sure healthy diets are supplied for each patient in the hospital, as well as on an individual level.   Ã‚  Ã‚  Ã‚  Ã‚  In a hospital environment there are typically a group of dieticians to handle all of the inpatient diets. These dieticians in turn answer to their department manager, who works under a chairman. In the dietary department there are also several filing and appointment clerks who help the dieticians to manage their work and keep them on track. These clerks are required because of the high-volume of work a hospital dietician is responsible for. Even though dieticians must regularly meet with patients and physicians, schedules for dieticians are very loose, and they can usually pick their own hours as long as they are at work for a certain amount of time each week.   Ã‚  Ã‚  Ã‚  Ã‚  Dieticians are typically very friendly and social people. In the mornings, a dietary department will usually spend an hour or so casually talking about their current cases or new dietary breakthroughs. In these sessions, dieticians will discuss important new knowledge about their field and about their patients while they drink a cup of coffee.   Ã‚  Ã‚  Ã‚  Ã‚  Dieticians will usually ge... ...of us want to help other people, and both of us are concerned with our own health and nutrition.   Ã‚  Ã‚  Ã‚  Ã‚  There are many positive reasons for me to become a dietician. As a dietician I would make a good amount of money, and could find work almost anywhere in the country. I would also be able to feed my love for science and researching skills. The only problem I could find with becoming a dietician is that I am a very mechanical person. This has been proven by the tests, but it is also backed by my own beliefs. Unfortunately, there is little hands-on physical work to be done by dietitians. Perhaps I could volunteer to rearrange the furniture once a week.   Ã‚  Ã‚  Ã‚  Ã‚  Educationally I am on the right path. In several weeks I will graduate high school with almost thirty college credit hours. I will need to take more chemistry, biology, and math classes. I plan on earning a masters degree in nutrition.   Ã‚  Ã‚  Ã‚  Ã‚  Overall, this is a very fitting choice for me. A dietitian has been something I have always wanted to become. After researching the job more and interviewing an actual dietitian, I have decided that it a sure bet for me. Career Summary Of A Dietician Essay -- essays research papers RESEARCH & FACTS The career I researched was that of a dietician. Someone who wishes to become a dietician must first obtain a bachelor’s degree, which would be considered a minimal requirement. Most dieticians will tell you that it would be within the best interests of a student wishing to become a dietician to get a master’s degree. Dieticians must have a love for science (chemistry in particular) and algebra as these skills are practiced routinely in the profession. It would also be a good idea for someone wishing to become a dietician to take some kind of accounting or book-keeping class, as dieticians must work on and file multiple records for each of their patients.   Ã‚  Ã‚  Ã‚  Ã‚  To become a dietician you must be willing to research every day. New scientific breakthroughs are made on a regular basis that are constantly changing the shape of the practice. Dieticians must also be willing to regularly meet with patients and physicians to accurately determine if their current dietary plan is working or not and what steps they should take to reach their final goal. Hospital dieticians correspond with the kitchen staff to make sure healthy diets are supplied for each patient in the hospital, as well as on an individual level.   Ã‚  Ã‚  Ã‚  Ã‚  In a hospital environment there are typically a group of dieticians to handle all of the inpatient diets. These dieticians in turn answer to their department manager, who works under a chairman. In the dietary department there are also several filing and appointment clerks who help the dieticians to manage their work and keep them on track. These clerks are required because of the high-volume of work a hospital dietician is responsible for. Even though dieticians must regularly meet with patients and physicians, schedules for dieticians are very loose, and they can usually pick their own hours as long as they are at work for a certain amount of time each week.   Ã‚  Ã‚  Ã‚  Ã‚  Dieticians are typically very friendly and social people. In the mornings, a dietary department will usually spend an hour or so casually talking about their current cases or new dietary breakthroughs. In these sessions, dieticians will discuss important new knowledge about their field and about their patients while they drink a cup of coffee.   Ã‚  Ã‚  Ã‚  Ã‚  Dieticians will usually ge... ...of us want to help other people, and both of us are concerned with our own health and nutrition.   Ã‚  Ã‚  Ã‚  Ã‚  There are many positive reasons for me to become a dietician. As a dietician I would make a good amount of money, and could find work almost anywhere in the country. I would also be able to feed my love for science and researching skills. The only problem I could find with becoming a dietician is that I am a very mechanical person. This has been proven by the tests, but it is also backed by my own beliefs. Unfortunately, there is little hands-on physical work to be done by dietitians. Perhaps I could volunteer to rearrange the furniture once a week.   Ã‚  Ã‚  Ã‚  Ã‚  Educationally I am on the right path. In several weeks I will graduate high school with almost thirty college credit hours. I will need to take more chemistry, biology, and math classes. I plan on earning a masters degree in nutrition.   Ã‚  Ã‚  Ã‚  Ã‚  Overall, this is a very fitting choice for me. A dietitian has been something I have always wanted to become. After researching the job more and interviewing an actual dietitian, I have decided that it a sure bet for me.

Male Versus Female

The battle of the sexes has been going on since the beginning of mankind. Women were once stereotyped as mere housewives, and the men were labeled as breadwinners. Over time, the title given to the so-called weaker sex has evolved up to par with that of men. Now, they almost stand on equal footing as them. When it comes to leadership though, I believe that females outshine their male counterparts in almost every measure. According to Rochelle Sharpe (2003), it has been approximately twenty-five years since women have started pouring into the labor force and have been trying to be more like men in every way. They now wear power suits and go out on golf luncheons with board executives, but despite them doing all the copying, new research is beginning suggest that men ought to be the ones doing more of the imitating. As discovered in an in-depth performance evaluation conducted on the year 2002 by Hagberg Consulting Group in Foster City, California – out of the four hundred twenty-five high-level executives that were evaluated, the women executives got higher ratings on fourty-two of the fifty-two skills measured. Despite all of this growing progress for females everywhere, it is still obvious that men have continued to dominate a majority of the business world. According to the Labor Department, as of the year 2004, only two of the nations five hundred biggest companies have female CEO’s and of the one thousand largest corporations, only six were being run by women. The reason for this male dominance is simply because women are not given an equal stand as men when it comes to job opportunities. Some businesses view women only as workhorses, or in a sense that they are well suited for demanding careers in middle management, but not for prime jobs. As a result of this, most women get stuck in jobs that involve human resources or public relations – posts that rarely lead to the top. (Sharpe, 2003) Both men and women have different styles of leadership, and the actual difference lies between how much listening is done. When it comes to women, they are naturally more open about sharing information and take the time to communicate with people and to hear what their inputs are. It is through this that they are able to gather more information that they can effectively analyze then implement into a plan that uses the best of the ideas presented. On the other hand, men do not take time to stop and smell the flowers – instead, they have the tendency to go straight to their point of view and present it in a ‘as a matter of fact’ manner. This way, they save time and have everyone agreeing to their plan of action. Well this is because men are not as flexible or willing to interact with others. (Grenberg, 2004) As a result, male leaders may actually tend to force their perspective and use their position influence others. Despite this being the quicker way of getting things done in a non-sloppy manner, it ironically does not make it as efficient as the way the opposite sex works. The manner that females work is by most of the time, simply listening. They take the initiative to gather ideas, research, and so forth from the people they are working with. They do not force their ideas on them, but rather, improve them with teamwork. It is because of this that they are able to produce better outputs and are more effective leaders than males. From the very start, women have often been associated with being a mother figure; therefore, even female leaders tend to be seen more as caring mothers rather than strong-willed heads. In relation to this, there are companies who assume that people skills are not business skills, which basically undermines their strengths. (Fletcher, 2002). Men though, are then associated with being the breadwinners of the family – a person who knows how to lead. Male leaders are seen as powerful members of society who have a good head on their shoulders and are tough enough to handle anything that comes their way. The notion that women are not as tough, is only something that is assumed. Although the majority may not be as physically strong as their counterpart, they are on the same level in terms of intellect. Women are associated with mothers, which means that they know how to take care of those working for them. Because they know how to deal with the most energetic of children, they can put their motherly instincts into motivating people – they are gifted with inborn people skills. According to the book Disappearing Acts: Gender, Power and Relational Practice at Work, written by Joyce Fletcher in 2002, employees that feel cared about by their bosses or are inspired by them, often produce higher-quality work; and supervisors who know how to deal with conflicts get better results. The conclusion can only be that by taking care of their employees, they are not only taking charge of them subtly but producing greater output in the process. In the present, the number of women that posses high-ranking positions may only add up to a mere fraction of the male population in the same position but it does not prove that the latter is more competent but rather that the former is being viewed as incompetent. The never-ending bias against female leaders has been going on forever, but they have been fighting back little by little. Women have come a long way from being a gender with no equality with the other sex, a gender that had no rights to vote, and a gender that had been stereotyped as a housewife. They have fought hard all these decades, and still continue to fight for the equality that they deserve. But despite the evident inequality, I still believe that female leaders outshine their male counterparts in almost every measure.

Racism in the Work Place

Racial discrimination at the workplace is, unfortunately, becoming common. It exists in workplaces across the world. With globalization and better work opportunities, people are traveling across to other countries and settling down. Their culture, traditions, interests, beliefs differ from that of the locals and this leads to a conflict of interest, of sorts. This can lead to racial discrimination at places of work, community, schools and so on. On April 14, 2005, the class action lawsuit Gonzalez v. Abercrombie & Fitch, was granted final approval settlement. The settlement requires the retail clothing giant to pay $50 million, less attorneys' fees and costs, to Latino, African American, Asian American and female applicants and employees who charged the company with discrimination. The settlement also requires the company to institute a range of policies and programs to promote diversity among its workforce and to prevent discrimination based on race or gender. Abercrombie & Fitch is a clothing retailer marketing to young adults, teenagers and children. It employs over 22,000 employees, most of whom are college-age adults, in over 700 stores throughout the United States. The settlement agreement also contains provisions related to the recruitment, hiring, job assignment, training, and promotion of Abercrombie & Fitch, Hollister, and Abercrombie Kids employees. The provisions include; †¢ A new Office and Vice President of Diversity, responsible for reporting to the CEO on Abercrombie’s progress toward fair employment practices. †¢ The hiring of 25 recruiters who will focus on and seek women and minority employees. Equal Employment Opportunity (EEO) and Diversity Training for all employees with hiring authority. †¢ A new internal complaint procedure. †¢ Abercrombie marketing materials that will reflect diversity by including members of minority racial and ethnic groups. In addition, Abercrombie created a $40 million Settlement Fund for distribution to individual class members. This will total approximately $ 10 million, bringing the total amount Abercrombie must pay to approximately $50 million. The young men and women who applied to work at Abercrombie should have been judged on their qualifications, and not their skin color or gender. The class action settlement compensates class members for being subjected to the challenged practices and ensures that Abercrombie will improve its employment practices and diversity efforts nationwide. Given that Abercrombie is a nationwide store, only proves that even today discrimination is very common and everyone should take a stand against it.

SPace and Religion the relationship essays

SPace and Religion the relationship essays For a lot of people the word science refers to the set of knowledge pertaining to the physical world, not just animate but also inanimate objects. But an actual definition would also have to include the attitudes and methods through which this group of knowledge is formed. An actual definition of science is, science is a branch of knowledge or study dealing with a body of facts or truths systematically arranged and showing the operation of generals laws(Random House Websters College Dictionary, 1178). Science is both a particular kind of activity and also the results of that activity. Theory and experiment work together in science, with experiments leading to new theories that in turn lead to further experiments. Although scientists generally share these methods and feelings, they do not provide a guaranteed means of scientific discovery. Every scientist uses their own way to research, experiment, and theorize, but they all try to invent one thing, a systematic way to go about provin g things. When something is proved or discovered it leads to new developments everywhere, especially in the field of technology. New scientific results may lead to new and more effective technology. Technology has been around much longer than science. As technology developed so did science. Technology is the branch of knowledge that deals with applied science, engineering, the industrial, arts and etc. The application of knowledge for practical ends(Random House Websters College Dictionary, 1343). Technology is considered to be a form of applied science. The scientific work is prepared and then applied to the technology. Everything you can think of has been a production of science and technology. Whether it has been developed from the scientific method or simply through trial and error. Many people that have used scientific technology include the wheel makers, ship builders, and todays engineers. Long...

The Weather Hazards Associated With Hurricanes

The Weather Hazards Associated With Hurricanes Every year, from June 1 to November 30, the threat of a hurricane strike looms in the minds of vacationers  and residents of  U.S.  coastlines. And its no wonder why. Because of its ability to travel across ocean  and land, a hurricane is almost impossible to outrun. In addition to having an evacuation plan in place, your best line of defense against hurricanes  is to know and recognize its  main hazards, of which there are four: high winds, storm surge, inland flooding, and tornadoes. High Winds As pressure drops inside of a hurricane, air from the surrounding atmosphere rushes into the storm, generating one of its trademark characteristics: winds. A hurricanes winds are among the first conditions to be felt during its approach. Tropical storm-force winds can extend as far as 300 miles (483 km) and hurricane-force winds can extend 25-150 miles (40-241 km) from the storm center. Sustained winds pack enough force to cause structural damage and carry loose debris. Remember that hidden within maximum sustained winds are isolated gusts that actually blow much faster than this. Storm Surge In addition to being a threat in and of itself, wind also contributes to another danger: storm surge. While a hurricane is out to sea, its winds blow across the ocean surface, gradually pushing water out ahead of it. A hurricane’s low pressure assists in this. By the time the storm nears the coast, water has â€Å"piled up† into a dome several hundred miles wide and 15 to 40 feet (4.5-12 m) high. This ocean swell then travels onshore, inundating the coast and eroding beaches. It is the primary cause of loss of life within a hurricane. If a hurricane approaches during high tide, an already risen sea level will lend additional height to a storm surge. The resulting event is referred to as a storm tide. Rip currents are another wind-induced marine hazard to watch for. As winds push water outward toward the shore, water is forced against and along the shoreline, creating a fast current. If there are channels or sandbars leading back out to sea, the current flows violently through these, whisking along anything in its path - including beachgoers and swimmers. Rip currents can be recognized by the following signs: A channel of churning, choppy waterAn area with a noticeable difference in color when compared to the surrounding oceanA line of foam or debris moving out to seaA break in the incoming wave pattern Inland Flooding While storm surge is the main cause of coastal inundation, excessive rains are responsible for the flooding of inland areas. A hurricanes rainbands can dump up to several inches of rain per hour, especially if a storm is moving slowly. This water overwhelms rivers and low-lying areas. When rainbands release water for several consecutive hours or days, this leads to flash and urban flooding.   Because tropical cyclones of all intensities (not just hurricanes) can produce excessive rains, freshwater flooding is considered the most wide-reaching of all tropical cyclone-related dangers. Tornadoes Embedded in a hurricanes rainbands are thunderstorms, some of which are strong enough to spawn tornadoes. Tornadoes produced by hurricanes are typically weaker (usually EF-0s and EF-1s) and shorter-lived than those occurring across the central and midwestern U.S. As a precaution, a tornado watch is usually issued when a tropical cyclone is forecast to make landfall. Beware the Right Front Quadrant A number of factors, including storm strength and track, influence damage levels caused by each of the above. But you may be surprised to learn that something as seemingly insignificant as which one of a hurricanes sides first makes landfall can also greatly increase (or lower) the risk of related hazards, especially storm surge and tornadoes. A direct hit from the right-front quadrant of a hurricane (left-front in the Southern Hemisphere) is considered the most severe. Thats because its here where the storms winds blow in the same direction as the atmospheric steering wind, causing a net gain in wind speed. For example, if a hurricane has sustained winds of 90 mph (category 1 strength) and is moving at 25 mph, its right front region would effectively have winds up to category 3 strength (90 25 mph 115 mph). Conversely, because winds on the left side oppose steering winds, a reduction in speed is felt there. Using the previous example, a 90 mph storm with 25 mph steering winds becomes a 65 mph effective wind. Since hurricanes continually spiral counter-clockwise (clockwise in the Southern Hemisphere) as they travel, it can be difficult to distinguish one side of the storm from another. Heres a tip: pretend youre standing directly behind the storm with your back in the direction its traveling. Its right side will be the same as your right. So if a storm is traveling due west, the right front quadrant would actually be its northern region.

Technology for Learning Article Example | Topics and Well Written Essays - 500 words

Technology for Learning - Article Example For young students the mind map and the systems based thinking can be quite simple as discussed in the article, but for more mature students, the system can be as complex as required. This is certainly a positive aspect of this manner of thinking since it has inherent scalability depending on the situation the teacher finds him/herself in. If the recommendations given by Coulter (2006) are used in the classroom, technology would become an intrinsic part of teaching as children use software and mind mapping tools to show their understanding of the systems around them. Further, it would also develop the idea of independent thought and individual creativity since the systemic understanding of a given situation could be different for individual children from varied backgrounds. For example, a child who comes from a very religious house may create a mind map in which a divine entity causes plants to grow rather than sunlight. Thus, with regard to the content of the article, a question can be asked if such liberties and a rather independent approach to teaching and learning could be managed effectively with children who are in very junior classes? If yes, then how would the problems associated with such learning be solved and if No, how could mind mapping tools be better used in the class

Exam Assignment Example | Topics and Well Written Essays - 250 words - 2

Exam - Assignment Example Dependency theory sees the world in the perspective of making poor nations or countries poorer, and enriching those that are already rich and wealthy. In other words, the inequality of countries across the world results in dominance by wealthy nations over poor nations. For example, developing countries like those in Latin America depend on the developed ones for aid among other things. With this, the developed economies deplete African resources in the name of the aids provided. The integration of weak economies is unfair relative to weak and string economies or countries in the world system. Trade agreement between the United States and Latin America would be seen as a means for United States to exploit Latin America. In the modernization theory, trade agreement between the United States and Latin America would be seen in a whole new perspective. The agreement would be treated as a bid to enhance economic relations between United States and Latin America. The move would be welcome in business and commerce terms relative to international interdependency that is based on the fact that no single nation is self-sufficient. On the other hand, the third way would see this agreement as a trail towards optimizing the welfare of both nations, in the consideration of their differences. Emerging economies like China are threatening the position of other strong nations in the world. Realism and liberalism would treat China’s rise in a global context. That is to say that China’s mode of interaction with the rest of the world would be evaluated in a global context. Given that China is more oriented towards a socialist political system, its position in realism would be characterized by the concept relations that only benefits China, a scenario that is likely to influence close associates of China like Brazil. On the other hand, liberalism would view China as a rather static nation in reforms, due to its high urge

Transport Authority Police Research Paper Example | Topics and Well Written Essays - 2500 words

Transport Authority Police - Research Paper Example In fact, without efficient leadership policies, plans, and practices, any changes in the management and the organization of the agency would not translate into improved service delivery (Burman & Evans, 2008). One of the major challenges faced by the Maryland Transport Authority Police for which a reformed leadership plan is recommended is the demographic differences between the agency and the department. A leadership plan that would incorporate strategies that address these demographic differences thus comes highly welcome for the benefit of the Maryland Transport Authority Police’s customers. The proposed leadership plan for the agency should support a culture that would contribute to the tackling of the major challenges the agency faces in its daily operations. In respect of the challenges it faces, this paper outlines a leadership plan for the Maryland Transport Authority Police with regards to its cultures, management, assessment, change, and crime statistics analysis. This leadership plan would also be quite influential in the manner the agency will investigate and interpret state, county, and city laws and codes violation within the confines and the jurisdiction of the Maryl and Transport Authority Police, including their stations, property, and vehicles. With this new millennium, increased globalization, and ease of transportation, the agency has encountered new types of challenges, which require that new and foolproof leadership plans and strategies are put in place (Burman & Evans, 2008). For instance, the current ease of movement has allowed more people to access ports and other modes of transports, implying the agency has to employ more officers (Burman & Evans, 2008). Hence, the leadership of the agency must ensure that the increased number of customers are well served and are satisfied. Protection must thus be provided to all the agency’s clientele who use the light

Modelling of Meromorphic Retina

Modelling of Meromorphic Retina CHAPTER 1 INTRODUCTION and literature review 1. INTRODUCTION The world depends on how we sense it; perceive it and how we act is according to our perception of this world. But where from this perception comes? Leaving the psychological part, we perceive by what we sense and act by what we perceive. The senses in humans and other animals are the faculties by which outside information is received for evaluation and response. Thus the actions of humans depend on what they sense. Aristotle divided the senses into five, namely: Hearing, Sight, Smell, Taste and Touch. These have continued to be regarded as the classical five senses, although scientists have determined the existence of as many as 15 additional senses. Sense organs buried deep in the tissues of muscles, tendons, and joints, for example, give rise to sensations of weight, position of the body, and amount of bending of the various joints; these organs are called proprioceptors. Within the semicircular canal of the ear is the organ of equilibrium, concerned with the sense of balance. General senses, which produce information concerning bodily needs (hunger, thirst, fatigue, and pain), are also recognized. But the foundation of all these is still the list of five that was given by Aristotle. Our world is a visual world. Visual perception is by far the most important sensory process by which we gather and extract information from our environment. Vision is the ability to see the features of objects we look at, such as color, shape, size, details, depth, and contrast. Vision is achieved when the eyes and brain work together to form pictures of the world around us. Vision begins with light rays bouncing off the surface of objects. Light reflected from objects in our world forms a very rich source of information and data. The light reflected has a short wavelength and high transmission speed that allow us a spatially accurate and fast localization of reflecting surfaces. The spectral variations in wavelength and intensity in the reflected light resemble the physical properties of object surfaces, and provide means to recognize them. The sources that light our world are usually inhomogeneous. The sun, our natural light source, for example, is in good approximation a point sou rce. Inhomogeneous light sources cause shadows and reflections that are highly correlated with the shape of objects. Thus, knowledge of the spatial position and extent of the light source enables further extraction of information about our environment. Our world is also a world of motion. We and most other animals are moving creatures. We navigate successfully through a dynamic environment, and we use predominantly visual information to do so. A sense of motion is crucial for the perception of our own motion in relation to other moving and static objects in the environment. We must predict accurately the relative dynamics of objects in the environment in order to plan appropriate actions. Take for example the following situation that illustrates the nature of such a perceptual task: the batsman a cricket team is facing a bowler. In order to get the boundary on the ball, he needs an accurate estimate of the real motion trajectory of the ball such that he can precisely plan and orchestrate his body movements to hit the ball. There is little more than just visual information available to him in order to solve the task. And once he is in motion the situation becomes much more complicated because visual motion information now represents the relative motion between him and the ball while the important coordinate frame remains static. Yet, despite its difficulty, with appropriate training some of us become astonishingly good at performing this task. High performance is important because we live in a highly competitive world. The survival of the fittest applies to us as to any other living organism, although the fields of competition might have slightly shifted and diverted during recent evolutionary trends. This competitive pressure not only promotes a visual motion perception system that can determine quickly what is moving where, in which direction, and at what speed; but it also forces this system to be efficient. Efficiency is crucial in biological systems. It encourages solutions that consume the smallest amount of resources of time, substrate, and energy. The requirement for efficiency is advantageous because it drives the system to be quicker, to go further, to last longer, and to have more resources left to solve and perform other tasks at the same time. Thus, being the complex sensory-motor system as the batsman is, he cannot dedicate all of the resources available to solve a single task. Compared to human perceptual abilities, nature provides us with even more astonishing examples of efficient visual motion perception. Consider the various flying insects that navigate by visual perception. They weigh only fractions of grams, yet they are able to navigate successfully at high speeds through complicated environments in which they must resolve visual motions up to 2000 deg/s. 1.1 ARTIFICIAL SYSTEMS What applies to biological systems applies also to a large extent to any artificial autonomous system that behaves freely in a real-world environment. When humankind started to build artificial autonomous systems, it was commonly accepted that such systems would become part of our everyday life by the year 2001. Numberless science-fiction stories and movies have encouraged visions of how such agents should behave and interfere with human society. And many of these scenarios seem realistic and desirable. Briefly, we have a rather good sense of what these agents should be capable of. But the construction is still eluding. The semi- autonomous rover of NASAs recent Mars missions or demonstrations of artificial pets are the few examples. Remarkably the progress in this field is slow than the other fields of electronics. Unlike transistor technology in which explosion of density is defined by the Moores law and also in terms of the computational powers the performance of autonomous systems is still not to the par. To find out the reason behind it we have to understand the limitation of traditional approaches. The autonomous system is the one that perceives, takes decision and plans action at a cognitive level, in doing so it must show some degree of intelligence. Returning back to the batsman example, he knows exactly what he has to do to dispatch the ball to the boundary, he has to get into a right position and then hit the ball with a precise timing. In this process, the photons hit the retina and then muscle force is applied. The batsman is not aware that this much is going on into his body. The batsman has a nervous system, and one of its many functions is to instantiate a transformation layerbetween the environme nt and his cognitive mind. The brain reduces and preprocesses the huge amount of noisy sensory data, categorizes and extracts the relevant information, and translates it into a form that is accessible to cognitive reasoning. Thus it is clear here that the there is cluster of process that takes place in a biological cognitive system in a very short time duration. And also that an important part of this whole process is transduction although it is not the one that can solely perform the whole complex task. Thus perception is the interpretationof sensory information with respect to the perceptual goal. The process is shown in the fig-1. 1.2 DIFFERENCE BETWEEN BIOLOGICAL SYSTEMS AND COMPUTERS The brain is fundamentally differently organized than a computer and science is still a long way from understanding how the whole thing works. A computer is really easy to understand by comparison. Features (or organization principles) that clearly distinguish a brain from a computer are: Massive parallelism, Distributed storage, Asynchronous processing, and Self organization. The computer is still a basically serially driven machine with a centralized storage and minimal self organization. The table 1.1 enlists these differences. Table 1.1 Differences in the organization principles and operation of computer and brain The digital computation may become so fast that it may solve the present problems and also it may become possible that the autonomous systems are made by digital components that are as powerful as efficient and as intelligent as we may imagine in our wildest dreams. However there are doubts in it and so we have to switch to an implementation framework that can realize all these things. 1.3 NEURAL COMPUTATIONS WITH THE HELP OF ANALOG INTEGRATED CIRCUITS It was Carver Mead who, inspired by the course â€Å"The Physics of Computation† he jointly taught with John Hopfield and Richard Feynman at Caltech in 1982, first proposed the idea of embodying neural computation in silicon analog very large-scale integrated (aVLSI) circuits. Biological neural networks are examples of wonderfully engineered and efficient computational systems. When researchers first began to develop mathematical models for how nervous systems actually compute and process information, they very soon realized that one of the main reasons for the impressive computational power and efficiency of neural networks is the collective computation that takes place among their highly connected neurons. And in researches, it is also well established that these computations are not undertaken digitally although the digital way is much simpler. Real neurons have a cell membrane with a capacitance that acts as a low-pass filter to the incoming signal through its dendrites; they have dendritic trees that non-linearly add signals from other neurons, and so forth. Network structure and analog processing seem to be two key properties of nervous systems providing them with efficiency and computational power, but nonetheless two properties that digital compute rs typically do not share or exploit. 1.4 LITERATURE REVIEW 1. Biological information-processing systems operate on completely different principles from those with which most engineers are familiar. For many problems, particularly those in which the input data are ill-conditioned and the computation can be specified in a relative manner, biological solutions are many orders of magnitude more effective than those we have been able to implement using digital methods. This advantage can be attributed principally to the use of elementary physical phenomena as computational primitives, and to the representation of information by the relative values of analog signals, rather than by the absolute values of digital signals. This approach requires adaptive techniques to mitigate the effects of component differences. This kind of adaptation leads naturally to systems that learn about their environment. Large-scale adaptive analog systems are more robust to component degradation and failure than are more conventional systems, and they use far less power . For this reason, adaptive analog technology can be expected to utilize the full potential of wafer scale silicon fabrication 2. The architecture and realization of microelectronic components for a retina-implant system that will provide visual sensations to patients suffering from photoreceptor degeneration. Special circuitry has been developed for a fast single-chip CMOS image sensor system, which provides high dynamic range of more than seven decades (without any electronic or mechanical shutter) corresponding to the performance of the human eye. This image sensor system is directly coupled to a digital filter and a signal processor that compute the so-called receptive-field function for generation of the stimulation data. These external components are wireless, linked to an implanted flexible silicon multielectrode stimulator, which generates electrical signals for electro stimulation of the intact ganglion cells. All components, including additional hardware for digital signal processing and wireless data and power transmission, have been fabricated using in-house standard CMOS technology 3. The circuits inspired by the nervous system that either help verifying neuron physiological models, or that are useful components in artificial perception/action systems. Research also aims at using them in implants. These circuits are computational devices and intelligent sensors that are very differently organized than digital processors. Their storage and processing capacity is distributed. They are asynchronous and use no clock signal. They are often purely analog and operate time continuous. They are adaptive or can even learn on a basic level instead of being programmed. A short introduction into the area of brain research is also included in the course. The students will learn to exploit mechanisms employed by the nervous system for compact energy efficient analog integrated circuits. They will get insight into a multidisciplinary research area. The students will learn to analyze analog CMOS circuits and acquire basic knowledge in brain research methods. 4. Smart vision systems will be an inevitable component of future intelligent systems. Conventional vision systems, based on the system level integration (or even chip level integration) of an image (usually a CCD) camera and a digital processor, do not have the potential for application in general purpose consumer electronic products. This is simply due to the cost, size, and complexity of these systems. Because of these factors conventional vision systems have mainly been limited to specific industrial and military applications. Vision chips, which include both the photo sensors and parallel processing elements (analog or digital), have been under research for more than a decade and illustrate promising capabilities. 5. Dr. Carver Mead, professor emeritus of California Institute of Technology (Caltech), Pasadena pioneered this field. He reasoned that biological evolutionary trends over millions of years have produced organisms that engineers can study to develop better artificial systems. By giving senses and sensory-based behavior to machines, these systems can possibly compete with human senses and brings an intersection between biology, computer science and electrical engineering. Analog circuits, electrical circuits operated with continuous varying signals, are used to implement these algorithmic processes with transistors operated in the sub-threshold or weak inversion region (a region of operation in which transistors are designed to conduct current though the gate voltage is slightly lower than the minimum voltage, called threshold voltage, required for normal conduction to take place) where they exhibit exponential current voltage characteristics and low currents. This circuit paradigm pr oduces high density and low power implementations of some functions that are computationally intensive when compared with other paradigms (triode and saturation operational regions). {A triode region is operating transistor with gate voltage above the threshold voltage but with the drain-source voltage lower than the difference between the gate-source voltage and threshold voltage. For saturation region, the gate voltage is still above the threshold voltage but with the drain-source voltage above the difference between the gate-source voltage and threshold voltage. Transistor has four terminals: drain, gate, source and bulk. Current flows between the drain and the source when enough voltage is applied through the gate that enables conduction. The bulk is the body of the transistor.}. As the systems mature, human parts replacements would become a major application area of the Neuromorphic electronics. The fundamental principle is by observing how biological systems perform these func tions robust artificial systems are designed. 6. In This proposed work a circuit level model of Neuromorphic Retina, this is a crude electronic model of biologically inspired smart visual sensors. These visual sensors have integrated image acquisition and parallel processing. Having these features neuromorphic retina mimics the neural circuitry of bionic eye. The proposed electronic model contains adaptive photoreceptors as light sensors and other circuit components such as averaging circuits, circuits representing ganglion cells, neuronal firing circuits etc that junction to sense brightness, size, orientation and shape to distinguish objects in closer proximity. Although image-processing features are available with modern robots but most of the issues related to image processing are taken care by software resources. Whereas machine vision with the help of neuromorphic retina is empowered with image processing at the front end. With added hardware resources, processing at the front end can reduce a lot of engineering resources for making electronic devices with sense of vision. 1.5 OBJECTIVES OF THE PRESENT WORK This project work describes a circuit level model of Neuromorphic Retina, which is a crude electronic model of biologically inspired smart visual sensors. These visual sensors have integrated image acquisition and parallel processing. Having these features neuromorphic retina mimics the neural circuitry of bionic eye. The proposed electronic model contains adaptive photoreceptors as light sensors and other neural firing circuits etc at junction to sense brightness, size, orientation and shape to distinguish objects in closer proximity. Although, image processing features are available with modern robots but most of the issues related to image processing are taken care by software resources. Whereas, machine vision with the help of neuromorphic retina is empowered with image processing at the front end. In this paper it has been shown that with added hardware resources, processing at the front end it can reduce a lot of engineering resources as well as time for making electronic devic es with sense of vision. . The objectives of present work are: Modelling of Neuromorphic Retina The photoreceptor block The horrizontal cell block The transistor mesh implemented with cmos technology The integerated block The integrated block of prs, horizontal cells and bipolar cells The spike generation circuit 1.6 Concluding Remarks In this chapter, the function of the artificial system, difference between brain and computer work is described. The present work is focused on designing of neuromorphic retina layer circuits. Many successful studies have been carried out by the researchers to study the behavior and failure of neuromorphic retina. Some investigators have performed the experimental work to study the phenomenon of the neuromorphic retina. Chapter 2 conations the biological neurons and the electronics of neuromorphic retina in this the descriptions of silicon neurons, electrical nodes as neurons, perceptrons, integrate fire neurons, biological significance of neuromorphic systems, neuromorphic electronics engineering methods, process of developing a neuromorphic chip. Chapter 3 describes the artificial silicon retina, physiology of vision, the retina, photon to electrons, why we require the neuromorphic retina?, the equivalent electronic structure, visual path to brain. In chapter 4 designing and implementation of neuromorphic retina in this the description of the photoreceptor block, the horrizontal cell block, the integerated block, the integrated block of photoreceptors, horizontal cells and bipolar cells, the spike generation circuit. In chapter 5 the design analyses and test results of neuromorphic retina layers. The results are summarized in the form of conclusion in Chapter 6 CHAPTER-2 BIOLOGICAL neurons AND neuromorphic electronics 2.1 INTRODUCTION Neuromorphic systems are inspired by the structure, function and plasticity of biological nervous systems. They are artificial neural systems that mimic algorithmic behavior of the biological animal systems through efficient adaptive and intelligent control techniques. They are designed to adapt, learn from their environments, and make decisions like biological systems and not to perform better than them. There are no efforts to eliminate deficiencies inherent in biological systems. This field, called Neuromorphic engineering, is evolving a new era in computing with a great promise for future medicine, healthcare delivery and industry. It relies on plenty of experiences which nature offers to develop functional, reliable and effective artificial systems. Neuromorphic computational circuits, designed to mimic biological neurons, are primitives based on the optical and electronic properties of semiconductor materials 2.1 BIOLOGICAL NEURONS Biological neurons have a fairly simple large-scale structure, although their operation and small-scale structure is immensely complex. Neurons have three main parts: a central cell body, called the soma, and two different types of branched, treelike structures that extend from the soma, called dendrites and axons. Information from other neurons, in the form of electrical impulses, enters the dendrites at connection points called synapses. The information flows from the dendrites to the soma, where it is processed. The output signal, a train of impulses, is then sent down the axon to the synapses of other neurons. The dendrites send impulses to the soma while the axon sends impulses away from the soma. Functionally, there are three different types of neurons: Sensory neurons They carry information from sense receptors (nerves that help us see, smell, hear taste and feel) to the central nervous system which includes the brain and the spinal cord. Motor neurons They carry information from the CNS to effectors (muscles or glands that release all kind of stuff, from water to hormones to ear wax) Interneuron They connect sensory neurons and motor neurons. It has a cell body (or soma) and root-like extensions called mygdale. Amongst the mygdale, one major outgoing trunk is the axon, and the others are dendrites. The signal processing capabilities of a neuron is its ability to vary its intrinsic electrical potential (membrane potential) through special electro-physical and chemical processes. The portion of axon immediately adjacent to the cell body is called axon hillock. This is the point at which action potentials are usually generated. The branches that leave the main axon are often called collaterals. Certain types of neurons have axons or dendrites coated with a fatty insulating substance called myelin. The coating is called the myelin sheath and the fiber is said to be myelinated. In some cases, the myelin sheath is surrounded by another insulating layer, sometimes called neurilemma. This layer, thinner than the myelin sheath and continuous over the nodes of Ranvier, is made up o thin cells called Schwann cells. Now, how do these things work? Inside and just outside of the neurons are sodium ions (Na+) and potassium ions (K+). Normally, when the neuron is just sitting not sending any messages, K+ accumulate inside the neuron while Na+ is kicked out to the area just outside the neuron. Thus, there is a lot of K+ in the neuron and a lot of Na+ just outside of it. This is called the resting potential. Keeping the K+ in and the Na+ is not easy; it requires energy from the body to work. An impulse coming in from the dendrites, reverses this balance, causing K+ to leave the neuron and Na+ to come in. This is known as depolarization. As K+ leave Na+ enter the neuron, energy is released, as the neuron no longer is doing any work to keep K+ in and Na+ out. This energycreates an electrical impulse or action potential that is transmitted from the soma to axon. As the impulse leaves the axon, the neuron repolarizes, that is it takes K+ back in and kicks Na+ out and restores itself to resting potential, ready to send another impulse. This process occurs extremely quickly. A neuron theoretically can send roughly 266 messages in one second. The electrical impulse may stimulate other neurons from its synaptic knobs to propagate the message. Experiments have shown that the membrane voltage variation during the generation of an action potential is generally in a form of a spike (a short pulse figure 2.2), and the shape of this pulse in neurons is rather stereotype and mathematically predictable. 2.2 SILICON NEURONS Neuromorphic engineers are more interested in the physiological rather than the anatomical model of a neuron though, which is concerned with the functionality rather than only classifying its parts. And their preference lies with models that can be realized in aVLSI circuits. Luckily many of the models of neurons have always been formulated as electronic circuits since many of the varying observables in biological neurons are voltages and currents. So it was relatively straight forward to implement them in VLSI electronic circuits. There exist now many aVLSI models of neurons which can be classified by their level of detail that is represented in them. A summary can be found in table 3.1. The most detailed ones are known as ‘silicon neurons. A bit cruder on the level of detail are ‘integrate and fire neurons and even more simplifying are ‘Perceptrons also known as ‘Mc Culloch Pitts neurons. The simplest way however of representing a neuron in electronics is to represent neurons as electrical nodes. Table 2.1 VLSI models of neurons 2.2.1 Electrical Nodesasneurons The most simple of all neuronal models is to just represent a neurons activity by a voltage or a current in an electrical circuit, and input and output are identical, with no transfer function in-between. If a voltage node represents a neuron, excitatory bidirectional connections can be realized simply by resistive elements between the neurons. If you want to add the possibility for inhibitory and mono directional connections, followers can be used instead of resistors. Or if a current represents neuronal activity then a simple current mirror can implement a synapse. Many useful processing networks can be implemented in this manner or in similar ways. For example a resistive network can compute local averages of current inputs. 2.2.2 Perceptrons A perceptron is a simple mathematical model of a neuron. As real neurons it is an entity that is connected to others of its kind by one output and several inputs. Simple signals pass through these connections. In the case of the perceptron these signals are not action potentials but real numbers. To draw the analogy to real neurons these numbers may represent average frequencies of action potentials. The output of a perceptron is a monotonic function (referred to as activation function) of the weighted sum of its inputs (see figure 3.3). Perceptrons are not so much implemented in analog hardware. They have originally been formulated as a mathematical rather than an electronic model and traditional computers are good at those whereas it is not so straight forward to implement simple mathematics into aVLSI. Still there exist aVLSI implementations of perceptrons since they still promise the advantage of a real fully parallel, energy and space conservative implementation. A simple aVLSI implementation of a perceptron is given in the schematics in figure 3.4. This particular implementation works well enough in theory, in practice however it is on one hand not flexible enough (particularly the activation function), on the other already difficult to tune by its bias voltages and prone to noise on the a chip. Circuits that have really been used are based on this one but were more extensive to deal with the problems. 2.2.3 Integrate Fire Neurons This model of a neuron sticks closer to the original in terms of its signals. Its output and its inputs are pulse signals. In terms of frequencies it actually can be modeled by a perceptron and vice versa. It is however much better suited to be implemented in aVLSI. And the spike communication also has distinct advantages in noise robustness. That is also thought to be a reason, why the nervous system uses that kind of communication. An integrate and fire neuron integrates weighted charge inputs triggered by presynaptic action potentials. If the integrated voltage reaches a threshold, the neuron fires a short output pulse and the integrator is reset. These basic properties are depicted in figure 2.5. 2.3 BIOLOGICAL SIGNIFICANCE OF NEUROMORPHIC SYSTEMS The fundamental philosophy of neuromorphic engineering is to utilize algorithmic inspiration of biological systems to engineer artificial systems. It is a kind of technology transfer from biology to engineering that involves the understanding of the functions and forms of the biological systems and consequent morphinginto silicon chips. The fundamental biological unit mimicked in the design of neuromorphic systems is the neurons. Animal brain is composed of these individual units of computation, called neurons and the neurons are the elementary signaling parts of the nervous systems. By examining the retina for instance, artificial neurons that mimic the retinal neurons and chemistry are fabricated on silicon (most common material), gallium arsenide (GaAs) or possibly prospective organic semiconductor materials. 2.4 NEUROMORPHIC ELECTRONICS ENGINEERING METHODS Neuromorphic systems design methods involves the mapping of models of perfection and sensory processing in biological systems onto analog VLSI systems which emulate the biological functions at the same time resembling their structural architecture. These systems are mainly designed with complementary metal oxide semiconductors (CMOS) transistors that enable low power consumption, higher chip density and integration, lower cost. These transistors are biased to operate in the sub-threshold region to enable the realizations of high dynamic range of currents which are very important for neural systems design. Elements of adaptation and learning (a sort of higher level of adaptation in which past experience is used to effectively readjust the response of a system to previously unseen input stimuli) are incorporated into neuromorphic systems since they are expected to emulate the behavior of the biological systems and compensate for imperfections in t Modelling of Meromorphic Retina Modelling of Meromorphic Retina CHAPTER 1 INTRODUCTION and literature review 1. INTRODUCTION The world depends on how we sense it; perceive it and how we act is according to our perception of this world. But where from this perception comes? Leaving the psychological part, we perceive by what we sense and act by what we perceive. The senses in humans and other animals are the faculties by which outside information is received for evaluation and response. Thus the actions of humans depend on what they sense. Aristotle divided the senses into five, namely: Hearing, Sight, Smell, Taste and Touch. These have continued to be regarded as the classical five senses, although scientists have determined the existence of as many as 15 additional senses. Sense organs buried deep in the tissues of muscles, tendons, and joints, for example, give rise to sensations of weight, position of the body, and amount of bending of the various joints; these organs are called proprioceptors. Within the semicircular canal of the ear is the organ of equilibrium, concerned with the sense of balance. General senses, which produce information concerning bodily needs (hunger, thirst, fatigue, and pain), are also recognized. But the foundation of all these is still the list of five that was given by Aristotle. Our world is a visual world. Visual perception is by far the most important sensory process by which we gather and extract information from our environment. Vision is the ability to see the features of objects we look at, such as color, shape, size, details, depth, and contrast. Vision is achieved when the eyes and brain work together to form pictures of the world around us. Vision begins with light rays bouncing off the surface of objects. Light reflected from objects in our world forms a very rich source of information and data. The light reflected has a short wavelength and high transmission speed that allow us a spatially accurate and fast localization of reflecting surfaces. The spectral variations in wavelength and intensity in the reflected light resemble the physical properties of object surfaces, and provide means to recognize them. The sources that light our world are usually inhomogeneous. The sun, our natural light source, for example, is in good approximation a point sou rce. Inhomogeneous light sources cause shadows and reflections that are highly correlated with the shape of objects. Thus, knowledge of the spatial position and extent of the light source enables further extraction of information about our environment. Our world is also a world of motion. We and most other animals are moving creatures. We navigate successfully through a dynamic environment, and we use predominantly visual information to do so. A sense of motion is crucial for the perception of our own motion in relation to other moving and static objects in the environment. We must predict accurately the relative dynamics of objects in the environment in order to plan appropriate actions. Take for example the following situation that illustrates the nature of such a perceptual task: the batsman a cricket team is facing a bowler. In order to get the boundary on the ball, he needs an accurate estimate of the real motion trajectory of the ball such that he can precisely plan and orchestrate his body movements to hit the ball. There is little more than just visual information available to him in order to solve the task. And once he is in motion the situation becomes much more complicated because visual motion information now represents the relative motion between him and the ball while the important coordinate frame remains static. Yet, despite its difficulty, with appropriate training some of us become astonishingly good at performing this task. High performance is important because we live in a highly competitive world. The survival of the fittest applies to us as to any other living organism, although the fields of competition might have slightly shifted and diverted during recent evolutionary trends. This competitive pressure not only promotes a visual motion perception system that can determine quickly what is moving where, in which direction, and at what speed; but it also forces this system to be efficient. Efficiency is crucial in biological systems. It encourages solutions that consume the smallest amount of resources of time, substrate, and energy. The requirement for efficiency is advantageous because it drives the system to be quicker, to go further, to last longer, and to have more resources left to solve and perform other tasks at the same time. Thus, being the complex sensory-motor system as the batsman is, he cannot dedicate all of the resources available to solve a single task. Compared to human perceptual abilities, nature provides us with even more astonishing examples of efficient visual motion perception. Consider the various flying insects that navigate by visual perception. They weigh only fractions of grams, yet they are able to navigate successfully at high speeds through complicated environments in which they must resolve visual motions up to 2000 deg/s. 1.1 ARTIFICIAL SYSTEMS What applies to biological systems applies also to a large extent to any artificial autonomous system that behaves freely in a real-world environment. When humankind started to build artificial autonomous systems, it was commonly accepted that such systems would become part of our everyday life by the year 2001. Numberless science-fiction stories and movies have encouraged visions of how such agents should behave and interfere with human society. And many of these scenarios seem realistic and desirable. Briefly, we have a rather good sense of what these agents should be capable of. But the construction is still eluding. The semi- autonomous rover of NASAs recent Mars missions or demonstrations of artificial pets are the few examples. Remarkably the progress in this field is slow than the other fields of electronics. Unlike transistor technology in which explosion of density is defined by the Moores law and also in terms of the computational powers the performance of autonomous systems is still not to the par. To find out the reason behind it we have to understand the limitation of traditional approaches. The autonomous system is the one that perceives, takes decision and plans action at a cognitive level, in doing so it must show some degree of intelligence. Returning back to the batsman example, he knows exactly what he has to do to dispatch the ball to the boundary, he has to get into a right position and then hit the ball with a precise timing. In this process, the photons hit the retina and then muscle force is applied. The batsman is not aware that this much is going on into his body. The batsman has a nervous system, and one of its many functions is to instantiate a transformation layerbetween the environme nt and his cognitive mind. The brain reduces and preprocesses the huge amount of noisy sensory data, categorizes and extracts the relevant information, and translates it into a form that is accessible to cognitive reasoning. Thus it is clear here that the there is cluster of process that takes place in a biological cognitive system in a very short time duration. And also that an important part of this whole process is transduction although it is not the one that can solely perform the whole complex task. Thus perception is the interpretationof sensory information with respect to the perceptual goal. The process is shown in the fig-1. 1.2 DIFFERENCE BETWEEN BIOLOGICAL SYSTEMS AND COMPUTERS The brain is fundamentally differently organized than a computer and science is still a long way from understanding how the whole thing works. A computer is really easy to understand by comparison. Features (or organization principles) that clearly distinguish a brain from a computer are: Massive parallelism, Distributed storage, Asynchronous processing, and Self organization. The computer is still a basically serially driven machine with a centralized storage and minimal self organization. The table 1.1 enlists these differences. Table 1.1 Differences in the organization principles and operation of computer and brain The digital computation may become so fast that it may solve the present problems and also it may become possible that the autonomous systems are made by digital components that are as powerful as efficient and as intelligent as we may imagine in our wildest dreams. However there are doubts in it and so we have to switch to an implementation framework that can realize all these things. 1.3 NEURAL COMPUTATIONS WITH THE HELP OF ANALOG INTEGRATED CIRCUITS It was Carver Mead who, inspired by the course â€Å"The Physics of Computation† he jointly taught with John Hopfield and Richard Feynman at Caltech in 1982, first proposed the idea of embodying neural computation in silicon analog very large-scale integrated (aVLSI) circuits. Biological neural networks are examples of wonderfully engineered and efficient computational systems. When researchers first began to develop mathematical models for how nervous systems actually compute and process information, they very soon realized that one of the main reasons for the impressive computational power and efficiency of neural networks is the collective computation that takes place among their highly connected neurons. And in researches, it is also well established that these computations are not undertaken digitally although the digital way is much simpler. Real neurons have a cell membrane with a capacitance that acts as a low-pass filter to the incoming signal through its dendrites; they have dendritic trees that non-linearly add signals from other neurons, and so forth. Network structure and analog processing seem to be two key properties of nervous systems providing them with efficiency and computational power, but nonetheless two properties that digital compute rs typically do not share or exploit. 1.4 LITERATURE REVIEW 1. Biological information-processing systems operate on completely different principles from those with which most engineers are familiar. For many problems, particularly those in which the input data are ill-conditioned and the computation can be specified in a relative manner, biological solutions are many orders of magnitude more effective than those we have been able to implement using digital methods. This advantage can be attributed principally to the use of elementary physical phenomena as computational primitives, and to the representation of information by the relative values of analog signals, rather than by the absolute values of digital signals. This approach requires adaptive techniques to mitigate the effects of component differences. This kind of adaptation leads naturally to systems that learn about their environment. Large-scale adaptive analog systems are more robust to component degradation and failure than are more conventional systems, and they use far less power . For this reason, adaptive analog technology can be expected to utilize the full potential of wafer scale silicon fabrication 2. The architecture and realization of microelectronic components for a retina-implant system that will provide visual sensations to patients suffering from photoreceptor degeneration. Special circuitry has been developed for a fast single-chip CMOS image sensor system, which provides high dynamic range of more than seven decades (without any electronic or mechanical shutter) corresponding to the performance of the human eye. This image sensor system is directly coupled to a digital filter and a signal processor that compute the so-called receptive-field function for generation of the stimulation data. These external components are wireless, linked to an implanted flexible silicon multielectrode stimulator, which generates electrical signals for electro stimulation of the intact ganglion cells. All components, including additional hardware for digital signal processing and wireless data and power transmission, have been fabricated using in-house standard CMOS technology 3. The circuits inspired by the nervous system that either help verifying neuron physiological models, or that are useful components in artificial perception/action systems. Research also aims at using them in implants. These circuits are computational devices and intelligent sensors that are very differently organized than digital processors. Their storage and processing capacity is distributed. They are asynchronous and use no clock signal. They are often purely analog and operate time continuous. They are adaptive or can even learn on a basic level instead of being programmed. A short introduction into the area of brain research is also included in the course. The students will learn to exploit mechanisms employed by the nervous system for compact energy efficient analog integrated circuits. They will get insight into a multidisciplinary research area. The students will learn to analyze analog CMOS circuits and acquire basic knowledge in brain research methods. 4. Smart vision systems will be an inevitable component of future intelligent systems. Conventional vision systems, based on the system level integration (or even chip level integration) of an image (usually a CCD) camera and a digital processor, do not have the potential for application in general purpose consumer electronic products. This is simply due to the cost, size, and complexity of these systems. Because of these factors conventional vision systems have mainly been limited to specific industrial and military applications. Vision chips, which include both the photo sensors and parallel processing elements (analog or digital), have been under research for more than a decade and illustrate promising capabilities. 5. Dr. Carver Mead, professor emeritus of California Institute of Technology (Caltech), Pasadena pioneered this field. He reasoned that biological evolutionary trends over millions of years have produced organisms that engineers can study to develop better artificial systems. By giving senses and sensory-based behavior to machines, these systems can possibly compete with human senses and brings an intersection between biology, computer science and electrical engineering. Analog circuits, electrical circuits operated with continuous varying signals, are used to implement these algorithmic processes with transistors operated in the sub-threshold or weak inversion region (a region of operation in which transistors are designed to conduct current though the gate voltage is slightly lower than the minimum voltage, called threshold voltage, required for normal conduction to take place) where they exhibit exponential current voltage characteristics and low currents. This circuit paradigm pr oduces high density and low power implementations of some functions that are computationally intensive when compared with other paradigms (triode and saturation operational regions). {A triode region is operating transistor with gate voltage above the threshold voltage but with the drain-source voltage lower than the difference between the gate-source voltage and threshold voltage. For saturation region, the gate voltage is still above the threshold voltage but with the drain-source voltage above the difference between the gate-source voltage and threshold voltage. Transistor has four terminals: drain, gate, source and bulk. Current flows between the drain and the source when enough voltage is applied through the gate that enables conduction. The bulk is the body of the transistor.}. As the systems mature, human parts replacements would become a major application area of the Neuromorphic electronics. The fundamental principle is by observing how biological systems perform these func tions robust artificial systems are designed. 6. In This proposed work a circuit level model of Neuromorphic Retina, this is a crude electronic model of biologically inspired smart visual sensors. These visual sensors have integrated image acquisition and parallel processing. Having these features neuromorphic retina mimics the neural circuitry of bionic eye. The proposed electronic model contains adaptive photoreceptors as light sensors and other circuit components such as averaging circuits, circuits representing ganglion cells, neuronal firing circuits etc that junction to sense brightness, size, orientation and shape to distinguish objects in closer proximity. Although image-processing features are available with modern robots but most of the issues related to image processing are taken care by software resources. Whereas machine vision with the help of neuromorphic retina is empowered with image processing at the front end. With added hardware resources, processing at the front end can reduce a lot of engineering resources for making electronic devices with sense of vision. 1.5 OBJECTIVES OF THE PRESENT WORK This project work describes a circuit level model of Neuromorphic Retina, which is a crude electronic model of biologically inspired smart visual sensors. These visual sensors have integrated image acquisition and parallel processing. Having these features neuromorphic retina mimics the neural circuitry of bionic eye. The proposed electronic model contains adaptive photoreceptors as light sensors and other neural firing circuits etc at junction to sense brightness, size, orientation and shape to distinguish objects in closer proximity. Although, image processing features are available with modern robots but most of the issues related to image processing are taken care by software resources. Whereas, machine vision with the help of neuromorphic retina is empowered with image processing at the front end. In this paper it has been shown that with added hardware resources, processing at the front end it can reduce a lot of engineering resources as well as time for making electronic devic es with sense of vision. . The objectives of present work are: Modelling of Neuromorphic Retina The photoreceptor block The horrizontal cell block The transistor mesh implemented with cmos technology The integerated block The integrated block of prs, horizontal cells and bipolar cells The spike generation circuit 1.6 Concluding Remarks In this chapter, the function of the artificial system, difference between brain and computer work is described. The present work is focused on designing of neuromorphic retina layer circuits. Many successful studies have been carried out by the researchers to study the behavior and failure of neuromorphic retina. Some investigators have performed the experimental work to study the phenomenon of the neuromorphic retina. Chapter 2 conations the biological neurons and the electronics of neuromorphic retina in this the descriptions of silicon neurons, electrical nodes as neurons, perceptrons, integrate fire neurons, biological significance of neuromorphic systems, neuromorphic electronics engineering methods, process of developing a neuromorphic chip. Chapter 3 describes the artificial silicon retina, physiology of vision, the retina, photon to electrons, why we require the neuromorphic retina?, the equivalent electronic structure, visual path to brain. In chapter 4 designing and implementation of neuromorphic retina in this the description of the photoreceptor block, the horrizontal cell block, the integerated block, the integrated block of photoreceptors, horizontal cells and bipolar cells, the spike generation circuit. In chapter 5 the design analyses and test results of neuromorphic retina layers. The results are summarized in the form of conclusion in Chapter 6 CHAPTER-2 BIOLOGICAL neurons AND neuromorphic electronics 2.1 INTRODUCTION Neuromorphic systems are inspired by the structure, function and plasticity of biological nervous systems. They are artificial neural systems that mimic algorithmic behavior of the biological animal systems through efficient adaptive and intelligent control techniques. They are designed to adapt, learn from their environments, and make decisions like biological systems and not to perform better than them. There are no efforts to eliminate deficiencies inherent in biological systems. This field, called Neuromorphic engineering, is evolving a new era in computing with a great promise for future medicine, healthcare delivery and industry. It relies on plenty of experiences which nature offers to develop functional, reliable and effective artificial systems. Neuromorphic computational circuits, designed to mimic biological neurons, are primitives based on the optical and electronic properties of semiconductor materials 2.1 BIOLOGICAL NEURONS Biological neurons have a fairly simple large-scale structure, although their operation and small-scale structure is immensely complex. Neurons have three main parts: a central cell body, called the soma, and two different types of branched, treelike structures that extend from the soma, called dendrites and axons. Information from other neurons, in the form of electrical impulses, enters the dendrites at connection points called synapses. The information flows from the dendrites to the soma, where it is processed. The output signal, a train of impulses, is then sent down the axon to the synapses of other neurons. The dendrites send impulses to the soma while the axon sends impulses away from the soma. Functionally, there are three different types of neurons: Sensory neurons They carry information from sense receptors (nerves that help us see, smell, hear taste and feel) to the central nervous system which includes the brain and the spinal cord. Motor neurons They carry information from the CNS to effectors (muscles or glands that release all kind of stuff, from water to hormones to ear wax) Interneuron They connect sensory neurons and motor neurons. It has a cell body (or soma) and root-like extensions called mygdale. Amongst the mygdale, one major outgoing trunk is the axon, and the others are dendrites. The signal processing capabilities of a neuron is its ability to vary its intrinsic electrical potential (membrane potential) through special electro-physical and chemical processes. The portion of axon immediately adjacent to the cell body is called axon hillock. This is the point at which action potentials are usually generated. The branches that leave the main axon are often called collaterals. Certain types of neurons have axons or dendrites coated with a fatty insulating substance called myelin. The coating is called the myelin sheath and the fiber is said to be myelinated. In some cases, the myelin sheath is surrounded by another insulating layer, sometimes called neurilemma. This layer, thinner than the myelin sheath and continuous over the nodes of Ranvier, is made up o thin cells called Schwann cells. Now, how do these things work? Inside and just outside of the neurons are sodium ions (Na+) and potassium ions (K+). Normally, when the neuron is just sitting not sending any messages, K+ accumulate inside the neuron while Na+ is kicked out to the area just outside the neuron. Thus, there is a lot of K+ in the neuron and a lot of Na+ just outside of it. This is called the resting potential. Keeping the K+ in and the Na+ is not easy; it requires energy from the body to work. An impulse coming in from the dendrites, reverses this balance, causing K+ to leave the neuron and Na+ to come in. This is known as depolarization. As K+ leave Na+ enter the neuron, energy is released, as the neuron no longer is doing any work to keep K+ in and Na+ out. This energycreates an electrical impulse or action potential that is transmitted from the soma to axon. As the impulse leaves the axon, the neuron repolarizes, that is it takes K+ back in and kicks Na+ out and restores itself to resting potential, ready to send another impulse. This process occurs extremely quickly. A neuron theoretically can send roughly 266 messages in one second. The electrical impulse may stimulate other neurons from its synaptic knobs to propagate the message. Experiments have shown that the membrane voltage variation during the generation of an action potential is generally in a form of a spike (a short pulse figure 2.2), and the shape of this pulse in neurons is rather stereotype and mathematically predictable. 2.2 SILICON NEURONS Neuromorphic engineers are more interested in the physiological rather than the anatomical model of a neuron though, which is concerned with the functionality rather than only classifying its parts. And their preference lies with models that can be realized in aVLSI circuits. Luckily many of the models of neurons have always been formulated as electronic circuits since many of the varying observables in biological neurons are voltages and currents. So it was relatively straight forward to implement them in VLSI electronic circuits. There exist now many aVLSI models of neurons which can be classified by their level of detail that is represented in them. A summary can be found in table 3.1. The most detailed ones are known as ‘silicon neurons. A bit cruder on the level of detail are ‘integrate and fire neurons and even more simplifying are ‘Perceptrons also known as ‘Mc Culloch Pitts neurons. The simplest way however of representing a neuron in electronics is to represent neurons as electrical nodes. Table 2.1 VLSI models of neurons 2.2.1 Electrical Nodesasneurons The most simple of all neuronal models is to just represent a neurons activity by a voltage or a current in an electrical circuit, and input and output are identical, with no transfer function in-between. If a voltage node represents a neuron, excitatory bidirectional connections can be realized simply by resistive elements between the neurons. If you want to add the possibility for inhibitory and mono directional connections, followers can be used instead of resistors. Or if a current represents neuronal activity then a simple current mirror can implement a synapse. Many useful processing networks can be implemented in this manner or in similar ways. For example a resistive network can compute local averages of current inputs. 2.2.2 Perceptrons A perceptron is a simple mathematical model of a neuron. As real neurons it is an entity that is connected to others of its kind by one output and several inputs. Simple signals pass through these connections. In the case of the perceptron these signals are not action potentials but real numbers. To draw the analogy to real neurons these numbers may represent average frequencies of action potentials. The output of a perceptron is a monotonic function (referred to as activation function) of the weighted sum of its inputs (see figure 3.3). Perceptrons are not so much implemented in analog hardware. They have originally been formulated as a mathematical rather than an electronic model and traditional computers are good at those whereas it is not so straight forward to implement simple mathematics into aVLSI. Still there exist aVLSI implementations of perceptrons since they still promise the advantage of a real fully parallel, energy and space conservative implementation. A simple aVLSI implementation of a perceptron is given in the schematics in figure 3.4. This particular implementation works well enough in theory, in practice however it is on one hand not flexible enough (particularly the activation function), on the other already difficult to tune by its bias voltages and prone to noise on the a chip. Circuits that have really been used are based on this one but were more extensive to deal with the problems. 2.2.3 Integrate Fire Neurons This model of a neuron sticks closer to the original in terms of its signals. Its output and its inputs are pulse signals. In terms of frequencies it actually can be modeled by a perceptron and vice versa. It is however much better suited to be implemented in aVLSI. And the spike communication also has distinct advantages in noise robustness. That is also thought to be a reason, why the nervous system uses that kind of communication. An integrate and fire neuron integrates weighted charge inputs triggered by presynaptic action potentials. If the integrated voltage reaches a threshold, the neuron fires a short output pulse and the integrator is reset. These basic properties are depicted in figure 2.5. 2.3 BIOLOGICAL SIGNIFICANCE OF NEUROMORPHIC SYSTEMS The fundamental philosophy of neuromorphic engineering is to utilize algorithmic inspiration of biological systems to engineer artificial systems. It is a kind of technology transfer from biology to engineering that involves the understanding of the functions and forms of the biological systems and consequent morphinginto silicon chips. The fundamental biological unit mimicked in the design of neuromorphic systems is the neurons. Animal brain is composed of these individual units of computation, called neurons and the neurons are the elementary signaling parts of the nervous systems. By examining the retina for instance, artificial neurons that mimic the retinal neurons and chemistry are fabricated on silicon (most common material), gallium arsenide (GaAs) or possibly prospective organic semiconductor materials. 2.4 NEUROMORPHIC ELECTRONICS ENGINEERING METHODS Neuromorphic systems design methods involves the mapping of models of perfection and sensory processing in biological systems onto analog VLSI systems which emulate the biological functions at the same time resembling their structural architecture. These systems are mainly designed with complementary metal oxide semiconductors (CMOS) transistors that enable low power consumption, higher chip density and integration, lower cost. These transistors are biased to operate in the sub-threshold region to enable the realizations of high dynamic range of currents which are very important for neural systems design. Elements of adaptation and learning (a sort of higher level of adaptation in which past experience is used to effectively readjust the response of a system to previously unseen input stimuli) are incorporated into neuromorphic systems since they are expected to emulate the behavior of the biological systems and compensate for imperfections in t