Market Risk Management Through The Use Of Options - Free Essay Example

Sample details Pages: 8 Words: 2422 Downloads: 6 Date added: 2017/06/26 Category Finance Essay Type Research paper Did you like this example? What is the role played by options, futures and forward contracts in managing market risks? The research critically analyzes this through the case study of Vodafone Group Plc. It first identifies the various factors that determine these risks since market risk includes different types of risks like commodity price risks, interest rate fluctuations risks and currency risks. Through the case study, it further aims to evaluate the effectiveness of using above derivatives, in managing market risks. Don’t waste time! Our writers will create an original "Market Risk Management Through The Use Of Options" essay for you Create order By considering the portfolio of company designed to hedge a particular amount of risk; the research also aims to critically evaluate the individual contributions of each of the above in risk management and also of the portfolio as whole. Introduction: Oxford dictionary defines risk as à ¢Ã¢â€š ¬Ã…“a situation involving exposure to dangerà ¢Ã¢â€š ¬? or à ¢Ã¢â€š ¬Ã…“expose (someone or something valued) to danger, harm, or lossà ¢Ã¢â€š ¬? (Oxford Dictionary). For a business entity à ¢Ã¢â€š ¬Ã…“Risksà ¢Ã¢â€š ¬? are connected to possible uncertainties that can result in negative effect on the entity. With the emergence of World Markets and various types of risks, risk management has become an integrated part of firms today. Different types of risks require different methods to handle, prevent or sometimes to absorb and benefit from risks. The downfall of risks has always been highlighted however they do have some arbitrage that results in potential gains. The Basel Committee that was formed in 1974 laid the regulatory framework for Financial Risk Management. (McNeil, Frey and Embrechts, 2005). Basel II (2001) defines Financial Risk Management to be formed of 4 steps: à ¢Ã¢â€š ¬Ã…“identification of risks into market, credit, operational and other risks; assessment of risks using data and risk model; monitoring and reporting of risk assessments on a timely basis and controlling these identified risks by senior management.à ¢Ã¢â€š ¬?(Alexander, 2005). It thus determines the probability of a negative event taking place and its effects on the entity. Once identified risk can be treated in following manners: Eliminated altogether by simple business practices. These are the risks that are detrimental to the business entity. Transferred to other participants. Actively managed at firm level. (Alexander, 1996). The risks basically depend on the time value of assets. Moreover with the increased level of multinational functioning of business entities and the highly volatile nature of markets, risk management has now become a critical part of running the business. It therefore becomes essential to understand as well as analyze the various factors that determine risks and the preventive measure s implemented against them. Also the hedging techniques being considered do not always ensure profits. The research would thereby include a detail study of the effectiveness of the methods implemented. One more important factor is the cost incurred. Risk management incurs certain costs and the process would therefore prove to be futile if the costs incurred donà ¢Ã¢â€š ¬Ã¢â€ž ¢t offer proportionally benefits. Literature Review: Market Risk constitutes of commodity risk, interest risk and currency risks. Commodity price risk includes the potential change in the price of a commodity. The rising or falling commodity prices affect the producers, traders and the end-users of the various commodities. Moreover if they are traded in foreign currency, there arises the risk of currency exchange rate. These are normally hedged by offering forward or future contracts at fixed rates. This is especially important for commodities like oil, natural gas, gold, electricity etc whose prices are highly volatile in nature. (Berk and Demarzo, 2010) Interest Risk relates to the change in interest rates of bonds, stocks or loans. A rising rate of interest would effectively reduce the price of a bond. Increased interest rates result in increasing the borrowing costs of the firm and thereby reduce its profitability. It is hedged by swaps or by investing in short term securities. Currency risks arise from the exceedingly vola tile exchange rates between the currencies of different countries. For e.g. Airbus, an aircraft manufacturing company based in France requires oil for its production. Oil being traded in US dollars and the company doing trading in Euros, has a foreign exchange risk. It would be therefore beneficial for Airbus to enter a forward contract with its oil suppliers. Options are another way of hedging against currency risks. (Berk and Demarzo, 2010). Forward contracts, Futures and Options are called the Financial Derivatives and are used largely to reduce market risks. Walsh David (1995) explains that if two securities have same payoffs in future, they must have same price today. Thus the value of a derivative moves in the same way as that of underlying asset. This is called arbitrage. Hedging of risks is nothing but the holder of an asset has two positions in opposite directions. One is of the derivative and opposite position is on the under-lying asset respectively. As such if t he value if the asset decreases then value of the derivative will also decrease. But the change in value is off-set by the opposite positions to each other. Thus risk is reduced. This is called hedging. Long Hedge refers when an investor anticipates increase in market price and therefore buys future contracts. Short Hedge is when an investor already has a futures contract and expects the value of asset to fall and therefore sells it beforehand. (Dubofsky and Miller, 2003) Long Hedge Short Hedge Change in value of position Change in price Change in value of position Change in price Fig.1 Hedging (Dubofsky, D and Miller, T. Jr. 2003) Forward Contracts- These involve buying or selling specific asset at a specific price at a specified time. It is basically a contract between two parties to trade a particular commodity or asset at a particular rate on a specified time. The buyer is said to be in à ¢Ã¢â€š ¬Ã‹Å"long positionà ¢Ã¢â€š ¬Ã¢â€ž ¢ while the seller hols the à ¢Ã¢â€š ¬Ã‹Å"short positionà ¢Ã¢â€š ¬Ã¢â€ž ¢. These are Over the Counter (OTC) Derivatives. These are used for locking-in the price and require no cash transfers in the beginning, thereby involve credit risks. Their main feature is the flexibility as forward contracts can be tailored as per the requirements of the traders. They are typically used to hedge the exchange rate risks. (Claessens, 1993) Futures- These are more standardized than the Forward contracts. They are traded at Foreign Exchanges. The standardized contract specifying the asset, price and delivery time is either bought or sold through broker. The delivery price depends on market and determined by the exchange. The default risk in futures is minimized due to clearinghouse. It acts as centred party and does the à ¢Ã¢â€š ¬Ã‹Å"marking to marketà ¢Ã¢â€š ¬Ã¢â€ž ¢ of tradersà ¢Ã¢â€š ¬Ã¢â€ž ¢ account; by doing profit-loss calculations daily. Initial margin amount is required and futures hence involve margin calls. Minimum credit risk is involved; but being standardized contracts, these cannot be tailored to individual demands. (Hinkelmann and  Swidler, 2004). Futures could be contracts on real assets for e.g. gold, oil, corn etc. or they could also be contracts of financial nature for e.g. currency, interest rates etc. (Tamiso and Freedman, 1995). Fig.2: Hedging through Futures. (Walsh, D. 1995) Options- The holder can buy from or sell to, the asset at a strike rate at a future maturity date. However the holder of the option has no moral obligation to do so. The cost of buying the option involves a premium which is to be paid up front. The option that enables the holder to buy an asset is called Call option while in Put option the holder is able to sell the asset. (Claessens, 1993) These can be bought Over the Counter (OTC) at a bank or can be exchange traded options. An American option could be exercised at any time before it expires. On the contrary, a European option has to b e exercised on maturity. Option is normally executed when its strike price is less than price of the stock. However, is the price of the stock is less than the strike price; the holder will not execute the option. Black and Scholes (1973) gave the formula to determine the price of a European option. According to the formula, the value of Call option is given by: where The value of Put option is given by: P = Ke-r (T-t) à ¢Ã¢â€š ¬Ã¢â‚¬Å" S + C = N(-d2) Ke-r (T-t) à ¢Ã¢â€š ¬Ã¢â‚¬Å" N(-d1) S. Where N (.) is a cumulative normal distribution function s- standard deviation of the share price, rf- risk-free interest rate per annum and t- time to expiry (in years). The above formula, also known as the Black-Scholes option pricing model; is based on the assumptions that the stock doesnà ¢Ã¢â€š ¬Ã¢â€ž ¢t pay any dividends, it is possible to buy or sell even a single share, there are no costs incurred in these transactions and that arbitrage opportunity doesnà ¢Ã¢â€ š ¬Ã¢â€ž ¢t exist. According to Black and Scholes (1973), à ¢Ã¢â€š ¬Ã…“the option value as a function of the stock price is independent of the expected return of the stock. The expected return of the option, however, will depend upon the expected return of the stock.à ¢Ã¢â€š ¬? Hence as the price of underlying asset increases, the price of option will also increase owing to their linear relationship. Black and Scholes (1972) further carried on various empirical tests to validity of the formula. They observed that price paid by the buyers of the option was higher than that shown by the formula. This was mainly because the transaction costs that are incurred are always paid by the buyers of the options. These costs were found to be high for options of high risks and vice-versa. The sellers of options thus got the price that was predicted by the formula. The case study would make use of this formula to determine the value of options held by the company. Walsh David (1995) exp lains that options have a non-linear relation with payoff. Its payoff increases with the price of the asset if it is in-the-money and has a constant payoff which is the option premium if it is out-of-the-money. On the contrary, futures and forward contracts have a linear relation with the payoffs in both, profit as well as loss. Therefore options might be preferred over futures and forwards for hedging. He further highlights the difference between hedging through futures and forward contracts. While in forward contracts, the company merely sets up a rate for future trading, it doesnà ¢Ã¢â€š ¬Ã¢â€ž ¢t involve any monetary transfer. Futures however make use of margin account and marking to market is done daily. Hence the results of futures over their time span vary greatly with those of forward contracts. Hence the individual contributions of each to risk management would be calculated during the research. The case study would also include a study the similarities and differences in futures, forward contracts and options and their individual effects on risk management. Data and Methodology: Objectives: The research aims to: Increase the understanding of the factors that determine market risks. Understand the haven provided by financial derivatives against these risks. Have a clear understanding of the methods or risk management techniques. Understand the process of risk management. Understand the intricacies of derivative markets. Data and Methodology: The Research is essentially a case study of Vodafone Group Plc. Primary data would include the information of the forward contracts with service providers, options and futures of the company in the market. Secondary data would be Qualitative in nature, comprising online journals, relative case studies and books. The research would be carried out in the following steps: Depending upon the nature of company, determine that factors that would affect the risk faced by the company. Evaluate the percentage of risk faced by the company. Determine the amount of this risk, which the company would want to hedge. The data would then be utilised to determine the amount of risk hedged by each of the above and then determine the total risk hedged by portfolio as whole. Calculate the cost of hedging the risk. Compare and contrast the findings with the defined à ¢Ã¢â€š ¬Ã‹Å"Effective Risk Management.à ¢Ã¢â€š ¬Ã¢â€ž ¢ Critically analyze the results. Suggest improvements if any, in the portfolio. Calculate the risk hedged with the suggested changes. Proposed Timetable: Date Activity 6th May, 2011 Submission of final proposal (By) 20th June, 2011 Collection of data as required by case study and start working on calculations. 1st July, 2011 Define the parameters for à ¢Ã¢â€š ¬Ã‹Å"effective risk managementà ¢Ã¢â€š ¬Ã¢â€ž ¢ and complete calculations. Complete the initial declaration pages of report. 15th July, 2011 Complete the literature review pertaining to case study. Finish report writing till that part. (up to 5000 words) 1st August, 2011 Compare and contrast the findings to the established parameters. Evaluate results. Some more relative literature review. 15th August, 2011 Finish writing the calculations, explaining results. Complete up to 10,000 words of report. 1st September, 2011 Complete the report and submit the first draft for feedback. 15th September, 2011 Redraft using the suggested changes. Final draft for submission 19th September, 2011 Final submission of the report. REFERENCES Alexander, C. (1996). The Handbook of Risk Management and Analysis. West Sussex: John Wiley Sons. Alexander, C. (2005). à ¢Ã¢â€š ¬Ã‹Å"The Present and Future of Financial Risk Management.à ¢Ã¢â€š ¬Ã¢â€ž ¢ Journal of Financial Econometrics, 3 (1), pp. 3-25. JSTOR (Online). Available at https://jfec.oxfordjournals.org/ (Accessed: 8th March, 2011). Berk, J and Demarzo, P. (2010). Corporate Finance. 2nd edn. Boston: Pearson. Black, F. and Scholes, M. (May Jun., 1973). à ¢Ã¢â€š ¬Ã‹Å"The Pricing of Options and Corporate Liabilities.à ¢Ã¢â€š ¬Ã¢â€ž ¢ The Journal of Political Economy.81 (3) pp. 637-654. JSTOR (Online). Available at https://www.jstor.org/stable/pdfplus/1831029.pdf?acceptTC=true (Accessed: 5th May, 2011). Black, F. and Scholes, M. (May 1972). à ¢Ã¢â€š ¬Ã‹Å"The Valuation of Option Contracts and a Test of Market Efficiency.à ¢Ã¢â€š ¬Ã¢â€ž ¢ The Journal of Finance.27 (2) pp 399-417. JSTOR (Online). Available at https://www.jstor.org/stable/2978484 (Accessed: 5th May, 2011). Claessens, S (1993). World Bank Technical Paper no 235.Washington DC: The World Bank. Dubofsky, D and Miller, T. Jr. (2003). Derivatives: Valuation and Risk Management. Oxford: Oxford University Press. Hinkelmann, C  Ãƒâ€šÃ‚  Swidler, S.  (2004). à ¢Ã¢â€š ¬Ã‹Å"Using futures contracts to hedge macroeconomic risk in the public sector.à ¢Ã¢â€š ¬Ã¢â€ž ¢ Derivatives Use, Trading Regulation.  10(1),  pp. 54-69. ABI/INFORM Global (Online) available at https://proquest.umi.com/pqdweb?index=0did=679304171SrchMode=2sid=1Fmt=6VInst=PRODVType=PQDRQT=309VName=PQDTS=1304643921clientId=18060 (Accessed: 21st March, 2011). McNeil, A.J., Frey, R., Embrechts, P. (2005) Quantitative Risk Management. Princeton and Oxford: Princeton University Press. Oxford Dictionary (Online) available at https://oxforddictionaries.com/?attempted=true (Accessed: 21st March, 2011). Tamiso, R. Freedman, R. (1995). à ¢Ã¢â€š ¬Ã‹Å"Confronting Uncertainty: Int elligent Risk Management with Futures.à ¢Ã¢â€š ¬Ã¢â€ž ¢ Artificial Intelligence in the Capital Markets: State-of-the-Art Applications for Institutional Investors, Bankers and Traders, Probus Publishing, Chicago. pp. 209-222. Available at https://www.inductive.com/RMR-FUT.pdf . (Accessed: 4th May, 2011). Walsh, David.   (1995). à ¢Ã¢â€š ¬Ã‹Å"Risk management using derivative securities.à ¢Ã¢â€š ¬Ã¢â€ž ¢Ãƒâ€šÃ‚  Managerial Finance.  21(1),  pp. 43. ABI/INFORM Global (Online).  Available at https://proquest.umi.com/pqdweb?index=6did=4708471SrchMode=2sid=3Fmt=6VInst=PRODVType=PQDRQT=309VName=PQDTS=1301258415clientId=18060 (Accessed: 27th March, 2011).

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Worldview ten Commandments and God free essay sample

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Oceanography Chapter 7 Essay Example

Oceanography Chapter 7 Paper An indirect method of measuring ocean current is the use of __________. radar altimeters A large system of rotating ocean currents, usually driven by the major wind belts, is called a(n) gyre The current in the northwestern part of the North Atlantic Subtropical Gyre that transports warm water toward the North Atlantic is called the Gulf Stream The loss of heat from the ocean surface, resulting in a lowered temperature, causes ocean water to become denser A deep and powerful southward subsurface current that flows under the Gulf Stream in the North Atlantic is the North Atlantic Deep Water Thermohaline circulation in the ocean is driven primarily by differences in __________ and __________ among water masses. temperature; salinity To produce a surface current of 1.6 knots in the open ocean, a steady wind of _____ knots would be required. 80 The actual movement of surface water due to Ekman transport in the Northern Hemisphere is about __________. 45 degrees to the right of the wind direction Of the following statements about subtropical gyres, which is/are true? 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South Pacific Subtropical Gyre Indian Ocean Subtropical Gyre South Atlantic Subtropical Gyre Of the following statements about Ekman spiral and Ekman transport, which is/are true? -within the ekman spiral, deeper water can move in a direction exactly opposite of the wind direction -The two factors that affect the ekman spiral are the wind direction and the Coriolis effect-because of the coriolis effect, surface waters move at an angle to the wind direction-connecting the arrows of water movement from the surface into deeper waters shows the spiral pattern-ekman transport is to the right of the wind direction in the northern hemisphere Of the following currents, which ones are parts of the South Atlantic Subtropical Gyre? Benguela Current We will write a custom essay sample on Oceanography Chapter 7 specifically for you for only $16.38 $13.9/page Order now We will write a custom essay sample on Oceanography Chapter 7 specifically for you FOR ONLY $16.38 $13.9/page Hire Writer We will write a custom essay sample on Oceanography Chapter 7 specifically for you FOR ONLY $16.38 $13.9/page Hire Writer West Wind Drift South Equatorial Current Brazil Current Downwelling can result from converging surface currents Of the following locations, where would upwelling be expected to occur? -where there is a sharp bend in a coastline-where there is a shallowly submerged sea floor obstruction, such as a tablemount-in areas of diverging surface currents,such as along the equator-in areas of offshore winds The thermocline is _________________. a steep temperature gradient in the ocean that separates deeper cold water from warmer upper water What is the Walker Circulation Cell? It is the path that air takes as it moves from high to low pressure, and back to high pressure, in the South Pacific under normal conditions. Why does upwelling occur along the west coast of South America under normal conditions? Winds moving westward in the South Pacific drive ocean currents toward the west; deep water rises to replace water driven westward. What would you expect weather to be like on the eastern coast of Australia if the western coast of South America were experiencing unusually warm, wet weather? What would you expect weather to be like on the eastern coast of Australia if the western coast of South America were experiencing unusually warm, wet weather?The eastern coast of Australia would be experiencing unusually dry weather.The eastern coast of Australia would be experiencing unusually wet weather.The eastern coast of Australia would be experiencing unusually cool weather.The eastern coast of Australia would be experiencing unusually warm weather. The eastern coast of Australia would be experiencing unusually dry weather. Which direction do ocean currents in the South Pacific move under El Nino conditions? Eastward What is the Southern Oscillation? What is the Southern Oscillation? Under which conditions are droughts and wildfires common in Australia? under El Nino conditions What is the overall effect of the stronger than normal trade winds typical of La Nina conditions? lowering of the South Pacific ocean temperature from normal conditions One of the world’s most powerful currents, located off the east coast of the United States, is the Gulf Stream The Gulf Stream transports warm water into the North Atlantic Fluctuations in the flow of the Gulf Stream current result in curving loops of water known as meanders Ocean frontal systems that spin off from currents such as the Gulf Stream, akin to atmospheric storms, are known as eddies When a meander from the Gulf Stream pinches off into the warm water south of the current, the eddy is called a cold-core eddy or ring The largest of the great ocean surface currents is the West Wind Drift Warm core rings and cold core rings are associated with western boundary currents Indian Ocean currents that are generated by seasonal changes in weather patterns are the __________ and __________ Currents. Somali/Southwest Monsoon During a strong El Nino event, the news media might be expected to cover a tropical cyclone in Hawaii or Tahiti Of the following conditions, which is/are related to strong El Nino events? -increase in sea surface temp. and destruction of coral reefs in the eastern pacific ocean-higher sea levels in the eastern pacific ocean associated with warmer water-increased abundance of hurricanes in the eastern pacific ocean Deep ocean current movement is also known as thermohaline flow Records indicate that the ocean is warming faster in the Arctic polar regions than elsewhere. If that continues, a possible consequence could be slowing of deep ocean circulation, resulting in lower oxygen levels in deep water Of the following statements about deep-ocean currents, which is/are true? -Deep-ocean currents contain water that is high in oxygen. -Deep-ocean circulation is often referred to as thermohaline flow. -The volume of water involved in the downward movement of deep-ocean currents is equal to the flow of 100 Amazon-sized rivers. -Deep-ocean currents are important regulators of global climate.-Deep-ocean currents are initiated by downwelling of cold, dense water near Antarctica and in the North Atlantic Ocean. (deep ocean currents often travel faster than surface currents) The coastlines with the greatest tsunami hazard are most commonly associated with what type of plate boundary? convergent Which of the following statements about earthquakes and tsunami hazards is most accurate? A relatively high number of earthquakes and the greatest tsunami hazard occur along the western coast of South America. Which of the following statements is most accurate about tsunami hazards and the number of people at risk? A low tsunami hazard and a high number of people at risk are present along the coast of the eastern United States. Which body of water is shown to have the greatest amount of coastal pollution? Baltic Sea Surface ocean currents ___. form large rotating gyres in the major ocean basinsare driven by windsare influenced by Coriolis effect Equatorial currents that are part of the subtropical gyres flow ___. Equatorial counter currents between the gyres flow ___ . east-to-west; west-to-east Warm ocean currents ___. are warming than the surrounding water Cool ocean currents ___. generally flow from high latitudes towards the equator The subtropical gyres ___. play a large role in climate Deep ocean currents ___. Deep ocean currents ___.

Expression and Perception in Huckleberry Finn essays

Expression and Perception in Huckleberry Finn essays Taking advantage of the immense popularity of an earlier novel, "The Adventures of Tom Sawyer (1876)," Mark Twain began working on its sequel, "The Adventures of Huckleberry Finn (1884)." The second work focused less on adventure and more on the slavery problem that then raged in the South, but put the work aside when it did not blend with the optimism of the Gilded Age that followed the Civil War. This optimism, however, began falling apart in the 1880s when the political program of reconstruction - whereby the defeated South would be reintegrated into the Union as a slavery-free region- collapsed because of the severe impositions of the North that embittered the South. Many Southern politicians tried to maintain power by controlling and oppressing black men and women whom the "The Adventures of Huckleberry Finn" became even more famous than Twain's earlier novel and enshrined him as one of America's preeminent writers. At the same time, it was the object of huge controversy because of its treatment of the slavery issue and his expression of rage over the injustices of his time. The novel was banned by the trustees of the Concord Massachusetts public library (March 18, 1885), while others criticized it as vulgar and racist, particularly for its use of the word "nigger." The public library committee refused to include the novel in its shelves, because it found the work not fit for "respectable people." The Boston Daily Globe (April 2, 1885) pictured Twain as a writer "of grotesque sketches that were coarse and strong and humorous." It deplored that he made a reputation and a fortune out of humor, and out of this, he became " a walking sign, a literary sandwich, placarded all over with advertisements of his wares." It noted how Twain had abused the public's acceptance of the fun he offered them by now asking the world to help him with h...

Learn About Causative Verbs

Learn About Causative Verbs In English grammar, a causative verb  is a verb  used to indicate that some person or thing makes s of causative verbs  include make, cause, allow, help, have, enable, keep, hold, let, force, and require, which can also be referred to as causal verbs or simply causatives. A causative verb, which can be in any tense, is generally followed by an object and another verb form- often an infinitive or a  participle  - and are used to describe something that happens because of a person, place, or thing whose actions bring about change in another entity. Interestingly enough, the word cause isnt the prototypical causative verb in English because cause has a much more specific and less frequently used definition than make, which is used most frequently to indicate someone making something happen. Allows vs. Lets English grammar is full of small rules that help speakers understand the vast  subtleties of correct usage and style. Such is the case with the rules pertaining to the causative verbs allows and lets, wherein both convey the same meaning - a person permits another to do something - but require different noun-verb form pairings to follow them. The word allows is almost always followed by an object, which in turn is followed by the infinitive form of the verb allows is modifying. Such is the case in the sentence Corey allows his friends to chat with him, wherein allows is the causative verb, his friends the object of the phrase, and to chat the infinitive form of what Corey is allowing his friends to do. On the other hand, the causative verbs lets is almost always followed by an object then the base form of the verb thats being modified. Such is the case in the sentence Corey lets his friends chat with him, wherein lets is the causative verb, his friends the object of the phrase, and chat the base form of the verb Corey lets his friends do. The Most Popular Causative Verb One would think that cause would be the most frequently used and typical example of causative verbs, but thats simply not the case. Francis Katamba explains in Morphology that the word cause is a causative verb but it has a more specialized meaning (implying direct causation) than make and it is much less common.   Instead, make is the most common causative verb, which also differs from other causative verbs in that it omits the word to from complementary verb clauses that follow while in the active form (make), but do require the word to while in the passive form of made. For example, Jill makes me run daily and I was made to run daily by Jill. In both senses, the causative verb make still implies that someone causes the subject to run, but English grammar dictates that the accompanying verb phrase for make differs for that of made. Rules like these abound in usage and style, and its important for English as an Alternative Language (EAL) students to commit these types of guidelines to memory - as they dont often appear in other forms.

The corporation Essay Example | Topics and Well Written Essays - 750 words

The corporation - Essay Example Furthermore, these facts and features of our economic and social development can support global economic and natural crisis which will be rather difficult to overcome. This paper will discuss such issues as economic growth problems, business ethics, consumerism, social and cultural critique, real consumer needs, social consequences of new technological opportunities, better distribution of resources, and some others. 2. Contemporary industry uses different methods to generate interest and reliance on various products, but these methods and strategies are not always supported by business ethics. These methods are: spam, infiltration, stealth marketing, incorrect information and many others. These methods fail business ethics and brake people's trust to corporations which make all possible efforts to promote their goods. Corporations should also take into account real needs of consumers. There are many goods which are not necessary for consumers to have them, such as glass ceilings and some others. Such consumer goods usually need great amount of natural resources and energy to produce them, and sometimes corporations waste these resources just to satisfy consumers' needs, and the consuming excess is clearly visible while natural resources are diminishing. ... We are taught as soon as we are old enough to comprehend images on TV that wanting things and buying things is good and healthy" (Capitalism, Consumerism, and Corporate Greed). Government attempts to resolve global economical and social problems have no positive effects. The misuse of government contracts for political and corporate gain supports deep consuming and social crisis which affect all sides of our life. Science and technology tries to resolve actual problems of our society. Science is rapidly developing, and such scientific innovations as findings of new sources of energy, nanotechnology, plastic surgery possibilities, new approaches to diagnostics and recovery and some others can bring benefit to our society. So, technological innovations can even save lives in extreme situations. But many scientific findings are of ambiguous effect, such as cloning, nuclear findings and different explorations in many areas of science, and it needs to use scientific achievements attentive ly and correctly. Incorrect and unethical use of technological innovations can result numerous global social problems, and they already can be visible in our society - people became more dependent on technological innovations. Global warming, many kinds of animals and plants petering are some of the most dangerous effects of technological progress abusing. There are still a lot of problems concerning our scientific knowledge, their influence on the environment and psychological aspects of our attitude to the environment and to ourselves, but it is obviously that new technologies can bring some kinds of benefit in case of safe and ethical use of these technologies. People gave up on materialism and look for new approaches for better distribution of resources. Materialism means

Compare and contrast the role of a Nurse Practitioner and a Essay

Compare and contrast the role of a Nurse Practitioner and a Physician's Assistant - Essay Example Physician assistants carry out their practice in partnership with medical practitioners and work in almost all specialties in the field of medicine. Physician assistants are trained in such a way that they can play the roles of a physician if need be. Creation of the physician assistant unit was crucial in many regions since the number of medical practitioners is considerably low. Additionally, this helped many countries provide health care in rural areas, inner sections of the city, as well as other areas where there are shortages of medical practitioners. As opposed to physician assistants, nurse practitioners tend to be somehow independent on their practice and are less reliant on physicians. Just like physician assistants, nurse practitioners can play most of the roles played by a physician. This paper focuses on comparing nurse practitioners and physician assistants by considering aspects such as their roles, education, job description, and scope of practice, job opportunities, and the scope of the practice. Education Education wise, a physician assistant is required to undergo a training program that takes about 26 months. Additionally, the physician assistants are required to have passed the national certified exam and holder of practice license. Furthermore, physician assistants are supposed to have accomplished clinical rotation in different specialties (Buppert, 2005; Miller & Kelli, 2012). A nurse practitioner is a registered nurse who has attained a master’s degree in nursing in addition to extensive clinical experience. The extensive clinical experience should be gained during the 12 to 16 months that nurse practitioners are supposed to spend treating mild as well as serious illnesses while under an instructors observation (Hooker, Cawley, & Leinweber, 2010; Buppert, 2005). Job Description Physician assistants are trained and certified health care professional that are supposed to work under the supervision of medical physician. On the other hand, nurse practitioners are trained and registered nurses who are certified and can thus conduct medical as well as operational tasks with minimal or no supervision from a physician. Physician assistants work in a wide range of medical fields. Majority of them are involved in providing primary care. Other duties may fall in other units such as assisting in surgical procedures, practicing internal medicine, emergency medicine, as well as in pediatric subspecialties. They may practice in hospitals, group physician practice, in rural or community health centers or as solo physician practice (Hooker, Cawley, & Leinweber, 2010; Buppert, 2005). Nurse practitioners are free to practice as private physicians after being certified. They also serve in the hospital inpatient and outpatient. Additionally, nurse practitioners work in rural health clinic where they offer community-based primary care. They can also work in the emergency department (Buppert, 2005). Role Responsibility Physician assistants practice in association with medical practitioners or physicians. Their role is interdependent with that of the physicians in what is described as â€Å"negotiated performance autonomy.† The roles of a physician assistant include taking the medical history of a patient and carrying out other investigations regarding the patients’ health. They are also responsible of examining the patients, assisting the physician in offering treatment to the patients, ordering

Unrealistic Optimism Gender and Culture Essay Example for Free

Unrealistic Optimism Gender and Culture Essay Several studies have been conducted to determine the influence that unrealistic optimism has over gender differences and culture. Unrealistic optimism is defined as the belief that positive (negative) events are more (less) likely to happen to one ’s self-versus others. Researchers have reported that both men and women from across cultures tend to be influenced by this bias. Nevertheless, they’ve found that Western cultures (such as Americans or Canadians) are identified by being independent and individualist, whereas Eastern cultures (such as Japanese) tend to focus on interdependence and collectivism. Given this basic traits, experimenters have discovered that Canadians tend to believe that positive events are more likely to happen to them, whereas Japanese tend to believe that they are more likely to experience negative events. In the other hand, both men and women have revealed to be unrealistically optimistic. However, men have reported higher levels of unrealistic bias compared to women around the world. Introduction Unrealistic optimism or optimistic bias is defined as the tendency for people to believe that they are more likely to experience positive events and less likely to experience negative events compared to others. (Weinsten, 1980). Taylor and Brown stated that almost 121 studies have demonstrated this phenomenon. Various findings have confirmed that American college students think that they were more likely than others to experience positive events such as getting a good job or forming a family. In opposition, most people think that they are less likely than others of experiencing negative events such as having a drinking problem or being fired from a job. The purpose of this essay is to determine the extent to which cultural and gender differences are influenced by unrealistic optimism. Unrealistic Optimism Unrealistic optimism could cause a negative effect over an individual’s life as it can distort their perception about reality. However, unrealistic optimism has also shown favorable effects over and individual’s well-being. This bias is significantly important because it can impact people’s intentions to engage in preventive behaviors. In addition, it can also affect the way in which people process information to update their beliefs. Furthermore, it has been demonstrated that optimistic bias appears to be motivated by threat. In other words, if a negative future event is perceived to be particularly serious, it’s more likely that the person will feel invulnerable toward that particular event. Western vs. Eastern Cultures The tendency of believing that one has better-than-average attributes has been researched and discussed lately. Researchers have found that people from Western cultures tend to be more unrealistically optimistic than people from Eastern cultures when comparing their chances of experiencing negative events to the average’s person. Markys and Kitayama stated that this bias influences every culture in a different way because they emphasize to tasks relevant to everyday life in different forms; independence and interdependence. Additionally, they stated that the cultures that have developed an independent construal of self are characterized by having an autonomous sense of self that’s different from others and the environment, whereas cultures that have fostered an interdependent construal of self are mutually reliant on each other and don’t attribute their individuality and uniqueness separately from the social world. Study #1 Cultural differences in unrealistic optimism and pessimism For this particular study participants form Japan and the United States responded to questions about negative health events that varied in event frequency and severity. The overall purpose of this study was to examine cultural differences in unrealistic optimism and pessimism through the direct versus the indirect method. The direct method involved a question in which participants compared themselves to the average group (e.g., â€Å"How likely are you to have a heart attack, relative to the average student of your age/sex?†). In the other hand, the indirect method involved a single question in which participants made absolute separate ratings for themselves (e.g., â€Å"How likely are you to have a heart attack?†). For the indirect method, the researchers predicted that participants across cultures would present different patterns. For instance, they expected that Japanese participants would report equal or higher risk estimates than for the average student for most events. In the other hand, they predicted that U.S participants would present higher risk estimates for themselves than for the average student for most events. In contrast, for the direct method investigators predicted that participants across cultures would report similar patterns of unrealistic optimism since cognitive biases such as egocentrism on direct comparisons will have a significant influence over respondents. After 127 students from the University of Iowa (United States) and 123 students from Kansai University (Japan) were tested through both the direct and the indirect methods, researchers acknowledged that in order to determine whether there are cross-cultural differences in unrealistic optimism they needed to take in consideration on whether direct or indirect comparisons were made. Considering the direct method, there was evidence that both Japanese and U.S. participants displayed high levels of unrealistic optimism about avoiding infrequent/negative events but, unrealistically pessimistic about avoiding frequent/negative events. However when measuring unrealistic optimism or pessimism through the indirect method the Japanese participants reported to have a tendency towards being less unrealistically optimistic than the U.S. participants. Contrarily, U.S participants showed that they tend to be more optimistic about themselves than for the average student for the majority of the events. Study#2 Does the West feel more vulnerable than the East?. At the same time, Steven J. Heine and Damn R. Lehman from the University of British Columbia compared the levels of unrealistic optimism between Canadians and Japanese through two different studies. The first study examined levels of unrealistic optimism exhibited by a sample typical of an independent construal of self (Canadians) and a sample typical of an interdependent construal of self (Japanese). Three different hypotheses were stated by the researchers. The first hypothesis anticipated that Canadians would show significantly more unrealistic optimism than Japanese; the second hypothesis drawn expected that constructs that have been shown to sustain the optimism bias, and availability of stereotypes, would be more pronounced in Canadians than in Japanese. And the last hypothesis predicted that Japanese’s optimism judgments will be less strongly related to threat whereas, Canadians unrealistic optimism would increase with perceived threat. For this particular study a total of 510 students who were taking different introductory psychology courses participated. Respondents were evenly separated between each of the Japanese and the Canadian samples. Moreover, in order to obtain membership in the westernized Canadian sample, respondents had to meet each of the following criteria: (a) the respondent had to be born in either Canada or the United States; (b) both of the respondents parents had to be born in Canada, the United States, or in a European country; (c) the respondent had to declare his or her ethnic descent to be that of a European culture; and (d) to keep the age range of the Canadian sample comparable to that of the Japanese sample, the respondent had to be between the ages of 18 and 25. All participants completed a questionnaire packet that included 15 future life events. Unrealistic optimism was measured for both negative and positive events through two methods: within-groups measure and between-groups measure. In the within-groups measure, participants had to respond questions about the chances they thought they had about experiencing a particular future event compared to other university students. In the other hand, through the between-groups measure the experimenters measured unrealistic optimism between groups. Participants received two different versions of the questionnaire. In the first version, beneath each future life event respondents were asked to estimate the absolute percentage chance that this event would happen to them. Contrarily, in the second version of the questionnaire, beneath each future life event, participants had to estimate the absolute percentage chance that a future event would happen to another same-sex student from their university. The assumptions made by Heine and Lehman about Study 1 were strongly supported since Japanese showed less unrealistic optimism than Canadians in all instances, regardless the methodology used. Surprisingly, experimenters found an in teresting pattern among participants’ estimates for themselves and others. Their findings suggested that Canadians tend to believe that positive events are more likely to occur to themselves in comparison to Japanese that reported to believe that positive events are less likely to happen to them than to others. Conversely, compared to Japanese, Canadians reported that the negative events were non significantly less likely to happen to themselves and significantly more likely to happen to others. Similarly, the main purpose for Study 2 was to examine only future life events. Researchers wanted to determine if Japanese would self-enhance more in cases in which their interdependence is threatened. Their findings were done through two subsets of future life events that we believed would be particularly threatening to people with independent and interdependent construals of self, respectively. Furthermore, Heine and Lehman anticipated that independent events would be perceived as more threatening than interdependent events for Canadians whereas interdependent ev ents would be perceived more threatening than independent events for Japanese. 215 introductory psychology students were taken in consideration for Study 2, including Japanese and Canadian students divided evenly within samples. All respondents completed a questionnaire which contained 10 questions about negative independent future events and 10 questions about interdependent future life events. These events were selected based on reasoning that independent events will threaten the individual; whereas interdependent events will threaten the individual’s relations with close others such as co-workers, friends or family members. The researchers’ findings revealed that comparing across cultures, Japanese perceived interdependent events to be more threatening than Canadians. Control and stereotype ratings were also examined in terms in how these independent and interdependent events would be rated. With respect to control, Canadians found that both independent and especially, independent events are more controllable. However, Japanese reported that in terdependent events are more controllable than independent events. Taken together both the controllability and severity findings, ratings suggest that negative future events were perceived differently by both cultures. As a result, Canadians and Japanese showed unrealistic optimism for both independent and interdependent events. In brief, Canadians were more unrealistically optimistic than Japanese for both independent and, especially, interdependent events whereas Japanese actually showed significant unrealistic pessimism for both types of events. Similarly, recent findings have shown several differences in the way in which genders (feminine and masculine) are influenced by unrealistic optimism. Most predictions suggest that men would show greater levels of unrealistic optimism than women. In fact, as women have a more interdependent self-construal of the self and men possess a more independent construal of the self, unrealistic optimism should be stronger and more resistant for men than for women. Furthermore, gender research has shown that men an d women have different expectations of marital quality; specifically different definitions of what constitutes a happy marriage Study #3 Gender differences in unrealistic optimism Two different studies held by Ying-Ching Lin and Priya Raghubir examined gender differences in optimistic bias, and their beliefs about marriage using a Taiwanese population. Study 1 tested the strength of the optimistic bias for men compared to women with respect to their expectations for a happy marriage or divorce. They hypothesised men to report higher levels of unrealistic optimism than women. In the other hand, Study 2 examined the bias’s resilience among men and women, and expected men’s beliefs to be less likely to be influenced by base rates compared to women. 309 students from a Taiwanese university were part of the study in which they had to respond to different questions regarding a target person (self, same-sex best friend, average undergraduate, and average person) and their likelihood of getting divorced or having a happy marriage. Half of the participants answered questions regarding the likelihood of having a happy marriage and the other half answered q uestions regarding the likelihood of getting divorced. Finally, they were asked to estimate the likelihood of an event occurring in the future from 0% to 100% for each of the four target persons. The results of this study suggested that Taiwanese men and Taiwanese women are unrealistically optimistic with respect to their relationships, and that men think that positive events, such as a happy marriage, are more likely to happen to them compared to an average person than women do. Similarly, they believe that negative events, such as divorce, are less likely to happen to them than to another person compared to women. 188 students participated in Study 2. They were divided into two groups assigned randomly to one of the two event conditions: happy marriage or divorce and were asked to estimate their own likelihood for that particular event. Subsequently, all participants were given base rate information for the event to which they were assigned (divorce = 25%, happy marriage = 60%). These base rates were based on an official publication of the Government Statistical Reports: Monthly Bulletin of Statistics. After being exposed to base rate information, all respondents were asked to estimate the likelihood of the event occurring to them, and to estimate the likelihood of the event occurring to someone else. The findings for this study reported, that both men and women show high levels of unrealistic optimism regarding a happy marriage and a divorce. Compared to men, women with a positive prior were influenced by the base rate information regarding a happy marriage. However, neither women nor men updated their estimates about their own divorce. In the other hand, men’s answers with a negative prior got influenced by the provided base rates at the beginning of the study whereas women’s answers were only influenced when talking about a happy marriage, but not about divorce. In general terms, both studies showed that both men and women tend to be influenced by optimistic bias about their expectations of their marriage. However, men showed greater levels of unrealistic optimism than women did. Regarding base rate information, women were more realistic in their estimates about a happy marriage compared to their estimates of getting divorced. Finally, only men with a negative initial prior were influenced by base rates whereas men with a positive initial prior do not updated their self- estimates. Gender vs. Culture The data used in both studies was collected using a Taiwanese sample (collectivist culture). However, the experimenters found that this bias is a universal phenomenon that occurs to both individualist and collectivist cultures. Moreover, recent work has reported that the bias is lower for participants who belong to collectivist cultures such as Japanese compared to individualist cultures such as Canadians. Because marriage is considered a relational aspect, consistent with a collectivist attribute, the population under this domain should show unrealistic levels of optimism. Conclusion Unrealistic optimism is a universal phenomenon that affects both gender and cultural differences around the world. Recent findings have demonstrated that both men and women across cultures (Eastern vs. Western) tend to be unrealistically optimistic about avoiding frequent/negative events, and unrealistically pessimistic about avoiding infrequent/negative events. However, the extent to which men vs. women and Eastern vs. Western cultures are affected by the bias varies among them. Being the West an independent and individualist culture, they report a higher tendency to be unrealistically optimistic. In contrast, being the East an interdependent and collectivist culture they present lower levels of unrealistic bias. At the same time, men and women have reported to be biased to some extent. Men have reported higher levels of unrealistic optimism, whereas women have shown to be less likely influenced by this threat. Now the question is: have you ever felt influenced by unrealistic bias?

America a Country Made by Africans :: essays papers

America a Country Made by Africans The development of Colonial America was based on the fundamental of slavery. Without the labor power of the first African/ Americans the existence of America would be incomprehensible. Countryman's statement, " Their story is "no exception" to what was otherwise a tale of success- it is absolutely fundamental to the history of colonial America." Countryman's statement is in fact correct. This country is was found upon the backbone of African Americans it is evident in the three essays of Countryman's book " How Did American Slavery Begin?" The three essays, which support Countryman's bold statement, are "Ancestry of Inferiority" by A. Leon Higginbotham Jr. "Gullah Roots" by Margaret Washington "Slavery and Freedom" by Edmund Morgan These essays specifically explain how the African Americans helped our founding fathers build this country physically economically and politically When the first African American set foot on this land he was here for one purpose and that was to serve someone, but that was also the same with a Caucasian American. Even though both black and white were treated the same it was obvious that being black was a disadvantage, 'sin'. Englishmen at that time believed that the color black was considered as "the handmaid of and symbol of baseness and evil†¦" (pg.88). Each servant when coming to America was to serve a master for a certain amount of years. The white servants served the masters for seven years because it was written in their contract which was made in England, but since the blacks came from Africa and had no sort of contract they were kept longer as servants (pg.88). This I believe is the bases for slavery, the more labors they had the more work could be done on plantation making more money. This is the physical part of the, which was built by Africans. The absolute economic success of this country was built on the back of an African American. Blacks were the actually labors and engineers who matched the amount of the world's demand on goods produced in America such as rice, indigo, tobacco, and cotton (pg.75). Certain blacks on the coasts of Guinea were adopted due to the fact they knew how to already ingeniously harvest rice and indigo (pg.73). This Coast became know as 'The Gold Coast'. This though was not the main reason for African Americans to be a major portion of the American labor system.

Cultural difference between US & China

The relative differences in the American and Chinese business background may well predict how transaction costs will be evaluated. On the part of the Chinese business criterion, it seems that the contrasting attitude of their business scheme may define a larger cost in trade investments for the American counterparts. The promising good trade partnership between American companies doing business with its Chinese segments may bring huge monetary concerns on the part of the former.The most significant attribute in the Chinese business core is the fact that their business structure is purely based on experience. This is very much evident since most of the companies are family-based businesses. As a result, there is no exact business trend that will make the companies adhere to the normal business plan as compared to the companies in the United States. This fact contributes largely to the aspect of limiting the flow of investment within a specific domain of the family owned business.One d isadvantage when it comes to costs is that an American company may not be able to induce its influence on the transaction if they are to deal with the Chinese based companies. The structured and well organized scheme employed by American companies may not be useful at all since the transaction will purely be based on the way the Chinese handle its business. The unpredictability of the financial aspect might take its toll in the American company’s investments. These will likely to happen even if the labor and commodity cost in china is very cheap.Also, there is not even a comparison of the Chinese and U. S. factory labor costs because reliable statistics from the Asian giant don't exist (News Analysis). This is a somewhat big drawback if the American company needs to assess the appropriate wage that it should set aside from its capital. Another big concern that will predict a very large cost discrepancy would be in the aspect of formal agreement. The Chinese tend to use fewer contracts when involving other sources of investment.This is very contrasting to the attitude of American companies where everything is settled on paper even before the activity proceeds. The Chinese companies tend to rely on trusted partnerships and loyalty of their background workforce for their own survival in the trade world. This could equate to a very high cost for the American company especially if the agreement will not be implemented according to the drafted plan. It is very possible that one segment of the production line will experience problems in business processing.Such scenario will eventually take effect on both the Chinese and American company in partnership. However, the larger cost will be incurred on the American company’s account. This is so because of the large dependency in a specified business plan. Moreover, there will be a waste in monetary values together with the production time frame just to take full recovery of the lost trade opportunity. This i s the most discouraging factor when it comes to unspecified productivity dilemmas.The global economy is starting to implement a rather large opportunity for all markets. Apparently, because of this global merchandising capacity of various countries, it would be very much accepted that the efficiency and survival of a certain business lies directly on the trading partners where it seems to be compatible with. On the case of the American and Chinese business relationship, it should first consider how the financial cost of partnership will eventually influence each other’s trading posts.A complete analysis of the cost attributes should be taken into consideration. Apparently, the behavior of Chinese business is very difficult to understand (Chen, 1999-2007). References: Chen, Ming-Jer. 1999-2007. Inside Chinese Business. QuickMBA. Retrieved May 8, 2007 from http://www. quickmba. com/mgmt/intl/china/. News Analysis. 2004. Just How Cheap Is Chinese Labor?. Businessweek. Retrieved May 8, 2007 form http://www. businessweek. com/bwdaily/dnflash/dec2004/nf2004122_6762_db039. htm.

Complex Relationships in Emily Bronte’s Wuthering Heights

Wuthering Heights Essay Rewrite: Within the novel Wuthering Heights, written by Emily Bronte, readers are confronted with many complex relationships. At times it is hard to understand these due to the range of relationships that occur, from interactions of hatred to relationships that show true passion. One such complex relationship is between Hareton Earnshaw and Catherine.As the novel progresses, we see love develop between these two characters that is best explained by how they are brought together, the problems that their relationship poses and how this relationship affects the other characters in the novel and the plot of the novel itself. The first way to understand this relationship is to examine how these two characters are brought together. In the novel, there is a real sense that fate has a lot to do with the union between the lovers, as Catherine and Hareton are reunited at the symbolic Penistone Crags.Catherine has a burning desire to go to the crags, the symbol of maturi ty, natural erotic desire and wild temptation. She asks Nelly and her father â€Å"Now, am I old enough to go to Penistone Crags? †(Bronte 147) As Catherine reaches teenage years, she desires to travel outside of Thrushcross Grange and ascend the large Penistone Crags, which are close to Wuthering Heights and Hareton. Catherine and Hareton spend the whole day near the Crags until Nelly fetches them.Bronte then describes the interaction between Hareton and Catherine as joyful, describing that â€Å"Her hat was hung against the wall, and she seemed perfectly at home laughing and chattering, in best spirits imaginable, to Hareton, now a great, strong lad of eighteen, who stared at her with considerable curiosity and astonishment† ( Bronte 149). This quote shows how there is an underlying connection between them; Hareton and Catherine begin to show similar characteristics in their relationship that Heathcliff and Cathy had in theirs, and this foreshadows how the relationsh ip will end up.The next interaction between the two is one day when Catherine meets Hareton and Heathcliff while on a stroll; Heathcliff makes it clear that Hareton is not his son. It is then insisted that she must come to Wuthering Heights to meet his son who she has met before, Linton. As Hareton and Catherine run off to play, Linton stays in seclusion as he is feeble and weak. The notion of Catherine running away with Hareton shows her natural tendencies and attraction for Hareton, because he allows her to be free and expressive. Ultimately, the two characters seem to be brought together by fate.In order for Hareton and Catherine to come together, they have to overcome many obstacles. The first problem that they run into is after Catherine is enlightened to the fact that Hareton is her cousin, she is disgusted by him. â€Å"†¦ she stopped and wept outright; upset at the bare notion of relationship with such a clown† (Bronte 152). This quote describes how Catherine thi nks of Hareton as a peasant or a servant and this devastates Hareton. The next problem that their relationship has is that Catherine is being forcibly courted by Linton, at the hand of his father.Heathcliff will do anything in order to fulfill his revenge, and thus will do anything to push the marriage between Catherine and Linton. An example of this is when Heathcliff literally kidnaps Catherine and refuses to let her leave Wuthering Heights until she agrees to marry Linton. It is obvious that Heathcliff is a major problem, preventing the love between Catherine and Hareton from materializing. Catherine realizes that Linton is vastly more educated than Hareton and that she can live a more refined lifestyle with Linton.Linton causes Hareton to feel great shame about his social and educational standing. A prime example of this is when Hareton and Catherine have run off, and Linton finds them standing below the inscription carved above the door. As â€Å"Hareton scared up, and scratch ed his head like a true clown. ‘It’s some damnable writing,’ he answered. ‘I cannot read it’† (Bronte 169). And almost immediately Linton takes the opportunity to degrade him in front of Catherine, laughing at him and calling him a â€Å"colossal dunce† (Bronte 170).This is the moment where Catherine seems to push away from Hareton, and lean towards Linton. Also not helping the situation is the declining health of Linton, as this draws Catherine more emotionally towards Linton and it completely devastates her. Bronte expresses through Nelly that â€Å"I couldn’t bear to witness her sorrow, to see her pale, dejected countenance, and heavy eyes† (Bronte 181). All the while, Hareton is barely mentioned, and later revealed that he has been teaching himself to read and write his own name, in an attempt to impress Catherine.As Hareton correctly identifies his name, he still cannot read the numbers, which causes Catherine to †Å"laugh heartily at his failure† and triggers the hot headed Hareton to â€Å"skull off† (Bronte 191). They are falling for each other, but there is a constant bickering between them due to Hareton’s lack of education—as he is not as accomplished as Linton. The deep burning desire to be together seems to be blocked by any and every character and event in the novel, yet the connection between Hareton and Catherine is easy to see.The final way to understand this relationship is to understand how it affects the characters in the play and how it drives the plot forward. Throughout the novel there had always been a sense that the relationship between Cathy and Heathcliff never died. And this relationship is kept alive by Hareton and Catherine. Whenever Heathcliff looks are Hareton, he sees Cathy, and it drives him insane, and this is a problem because Heathcliff’s motivation in life was to get revenge on the Linton family.This revenge is what propelled t he novel forward, and when Heathcliff sees that Hareton and Catherine are happy, things within him click and he no longer desires to fulfill his plans. â€Å"†¦his society is no benefit, rather an aggravation of the constant torment that I suffer and it partly contributes to render me regardless how he and his cousin go together. I can give them no attention, anymore† (Bronte 248). This quote shows how Heathcliff no longer wants to give attention to his plans of revenge, because Hareton and Catherine are happy.This helps understand their relationship because even though Heathcliff was the mastermind behind everything, they were still able to find love and be happy, something that Heathcliff was never able to do with Cathy. It is as though the relationship was destined to happen, to fulfill not only the lives of Hareton and Catherine, but the souls of Heathcliff and Cathy. Even though the relationship between Hareton and Cathy was hard to understand, an explanation for th eir love can be made by examining the interactions them and characters in the novel and the overall plot of the story.This relationship served as an the final chapter to a cycle of revenge that Heathcliff started by showing him that even under pressure love can prevail. The complex relationship between Hareton and Catherine ultimately expelled the tension between the two estates and rid Heathcliff of his vengeful plots. Overall, this relationship was exemplified by how fate dictated their love, their interactions and their representation for a love of a previous generation.

Antoinette Johnson essays

Antoinette Johnson essays All month long in honor of Black History Month, we've been bringing you profiles in courage. Tonight, a woman who helps make the "American Dream" come true for people across South Florida. (WSVN) It's one thing for someone to tell you that you're going to get a house. But to actually see your house ..I think that was the thing that really got huh...." Tears trickle from the eyes of thirty-three year old Antoinette Johnson as she tells a story that flows from her heart. A story about her trials ... and her triumphs. Antoinette Johnson says, "They are tears of joy and happiness .. remembering where I've come from and where I am now." For Antoinette Johnson, there once was a time when the thought of owning her own home seemed impossible. But now, this single mother of two knows *anything* is possible. She says, "I've been through a lot .. trying to raise two daughters is very hard. It was very hard." It was difficult for Antoinette to raise her daughters, fourteen year-old Jasmine and eleven year-old Jalissa. Antoinette says, "I'm not saying it's not hard now. But it's a little bit easier. It's a little bit easier." Easier, because Antoinette and her children have found safety in their home here in Fort Lauderdale....Away from the danger they once found at this apartment complex in Lauderhill. She says, "People chasing my kids down the street coming home from school. The kids were terrified to even walk home from the bus stop which was right down the street." For Antoinette and her daughters there really is no place like home. A house made possible by Habitat For Humanity of Broward County two years ago. now, Antoinette sits on the Habitat For Humanity board of directors and two committees committed to selecting and helping others each achieve the same dream. Antoinette says, "If I don't do anything but help another family to get a home I'm happy." She adds, "I enjoy seeing them when the ...

The Early History of Flight

The Early History of Flight   Around 400 BC - Flight in China The Chinese’s discovery of a kite that could fly in the air started humans thinking about flying. Kites were used by the Chinese in religious ceremonies. They built many colorful kites for fun, also. More sophisticated kites were used to test weather conditions. Kites have been important to the invention of flight as they were the forerunner to balloons and gliders. Humans Try to Fly like Birds For many centuries, humans have tried to fly just like the birds and have studied the flight of winged creatures. Wings made of feathers or light weight wood have been attached to arms to test their ability to fly. The results were often disastrous as the muscles of the human arms are not like a birds and cannot move with the strength of a bird. Hero and the Aeolipile The ancient Greek engineer, Hero of Alexandria, worked with air pressure and steam to create sources of power. One experiment that he developed was the aeolipile, which used jets of steam to create rotary motion. To do this, Hero mounted a sphere on top of a water kettle. A fire below the kettle turned the water into steam, and the gas traveled through pipes to the sphere. Two L-shaped tubes on opposite sides of the sphere allowed the gas to escape, which gave a thrust to the sphere that caused it to rotate. The importance of the aeolipile is that it marks the start of engine created movement will later prove essential in the history of flight. 1485 Leonardo da Vinci’s Ornithopter and the Study of Flight. Leonardo da Vinci  made the first real studies of flight in the 1480s. He had over 100 drawings that illustrated his theories on bird and mechanical flight. The drawings illustrated the wings and tails of birds, ideas for man carrying machines and devices for the testing of wings. His Ornithopter flying machine was never actually created. It was a design that Leonardo da Vinci created to show how man could fly. The modern day helicopter is based on this concept. Leonardo da Vincis notebooks on flight were re-examined in the 19th century by aviation pioneers. 1783 - Joseph and Jacques Montgolfier and The Flight of the First Hot Air Balloon Two brothers,  Joseph Michel and Jacques Etienne Montgolfier, were inventors of the first hot air balloon. They used the smoke from a fire to blow hot air into a silk bag. The silk bag was attached to a basket. The hot air then rose and allowed the balloon to be lighter than air. In 1783, the first passengers in the colorful balloon were a sheep, rooster and duck. It climbed to a height of about 6,000 feet and traveled more than one mile. After this initial success, the brothers began to send men up in hot air balloons. The first manned hot air balloon flight was carried out on November 21, 1783 and the passengers were Jean-Francois Pilatre de Rozier and Francois Laurent. 1799-1850s - George Cayley’s Gliders Sir George Cayley is considered the father of aerodynamics. Cayley experimented with wing design, distinguished between lift and drag and formulated the concepts of vertical tail surfaces, steering rudders, rear elevators and air screws. He also designed many different versions of gliders that used the movements of the body for control. A young boy, whose name is not known, was the first to fly one of Cayleys gliders. It was the first glider capable of carrying a human. For over 50 years, George Cayley made improvements to his gliders. Cayley changed the shape of the wings so that the air would flow over the wings correctly. He also designed a tail for the gliders to help with the stability. He then tried a biplane design to add strength to the glider. Additionally, Cayley recognized that there would be a need for machine power if the flight was to be in the air for a long time.

Sustainable Development in Business Case Study Example | Topics and Well Written Essays - 3500 words

Sustainable Development in Business - Case Study Example (Organisational Sustainability, n.d.) Andrew Mangan, an environmental entrepreneur promoted BPS or by-product synergy programs as a means to achieve the goals of sustainable development. It is a process that helps the companies to discover new ways in order to convert the waste products into saleable commodities. The goal of Mangan is actually twofold - to promote the wider adoption of BPS programs and also to create business out of helping the companies adopt such by-product synergy programs. (Anderson T., and Mackenzie S., n.d.) There has been a lot of research in the field of sustainable technology and design along with the adaptation of business tools, but in most of the instances, the well designed technologies fail to become broadly adopted, not due to the fact that there are flaws in the technology but due to the reason that there is inadequate sustainable method of servicing, distributing, and improving the technology. Any business needs start up capital in order to fund the design of technology and its development along with a self sustaining revenue stream, which would support the growth as well as be meaningful in terms of reducing pollution. The reason behind the development of EnviroFit International business model was to allow for the design, development along with the dissemination of environment friendly technologies all over the world. This model leverages the participation of the local in country stakeholders in order to ease acceptance and the implementation of RetroFit technology. The key components of this model are using donations for the development of technology as well as operating profits from the product sales to growth, support operations, emissions trading, microfinance and also local partnerships. This business model is till in progress and is executing the business plan along with reducing the perceived risks, by making progress against the value setting milestones like raising investment capital, field tests and developing important partners in supply chain; these would increase the credibility of the business model and also its management. This business model would be highly beneficial for those environmental technologies that lack necessary profit margins in order to make them attractive to the traditional for-profit model. This would provide sufficient margins in order to sustain a particular enterprise without continued infusions of donations or capital. This business model would also in effective in reducing the environmental pollution. (Hudnut P., B auer T. and Lorenz N., n.d.) Triple Bottom Line was originated among the investors seeking a way of putting their money in those enterprises that are economically profitable, socially just and environmentally sound. It is the need of the time to model the systems properties or the ecological characteristic of various domains of productivity and also to design the institutions of monetary and financial services, which can optimize the productivity in these domains. The theory and the institutions should base on the concepts of triple bottom line. The concept of

What do we mean by navigating another culture Essay - 1

What do we mean by navigating another culture - Essay Example When people from another culture interact with that particular society, they have to understand the cultural behavior of the host society and refrain from offending them by any indication that they do not respect the other culture. For this, they have to examine various characteristics and ramifications of another culture. As per the experts, all cultures share four major characteristics which are common in different cultures (Sarkar, 2010). It includes symbols which reflect on the art, religion, language and finance of that particular culture. When dealing with people from other culture, it is necessary to keep the open mind and learn the nuances of the other culture for a successful social outcome. When navigation of other culture is concerned, it is also necessary for a person to learn the core philosophy of that culture’s values (Hofstede et al, 2010). He or she should also understand various geo-political, socio-economic and cross-cultural factors such as traditions, customs, religious and social values such as taboos and ethos at the time of navigation in another culture. The person while navigating another culture, should always remember that something such as lack of respect, appreciation or ignorance about another cultural milieu can lead to breakdown in communication and goodwill from the people of another culture. In fact, if one tries to understand or imitate their ways while with them, it will lead to wholehearted support as well as enhancement of goodwill. Sarkar, A,N. Navigating the Rough Seas of Global Business Negotiation: Reflection on Cross-Cultural Issues and Some Corporate Experiences, UBIT [Online], Volume 3 issue 2, 48, 2010. Available at: https://commons.esc.edu/globalissues/wp-content/uploads/sites/1354/2014/05/navigating-global-negotiations.pdf [Accessed 07 February

Computer Crime Research Paper Example | Topics and Well Written Essays - 750 words

Computer Crime - Research Paper Example In July 2012 a major security breach took place against Yahoo that resulted in 450,000 usernames and passwords to be disclosed (Gonsalves, 2012). This event raised many questions regarding the precautionary measures taken by Yahoo to protect the security of its users. Instead of storing the passwords cryptographically they were stored as plain texts which made it very easy for hackers to gain access to this confidential data. Usually usernames and passwords are stored using the cryptography technique which encrypts the data thereby hiding the information. This encryption prevents hackers from deciphering the data. Yahoo refused to give an interview but confirmed the breach saying that the data was stolen via its Contributor Network, which is one of the websites owned by Yahoo. Yahoo Contributor Network is a Yahoo website for freelance content writers that write articles for another of its website Yahoo Voice. Although only five percent of the stolen data had valid passwords, Yahoo an nounced that they were taking prompt action to fix the susceptibility that led to the exposure of the passwords. Yahoo notified the other companies about the accounts that had been hacked including LinkedIn, Gmail, Hotmail, AOL, and so on (Gonsalves, 2012). The hacker group called D33Ds Company admitted to be responsible for the breach through a statement that they published on their website. The hackers said that the security breach was meant to be a warning for Yahoo and not a threat. They also alleged to having used the program SQL injection which is normally used to send instructions using the search field or a URL to breach a badly secured website. The SQL injection allowed the hackers to gain access to the database containing the usernames and passwords (Gonsalves, 2012). The event happened just before the annual shareholder’s meetings at Yahoo and the temporary CEO Ross Levinsohn said that they were looking for a transparent strategy in order to bring back their invest or confidence (Chaykowski & Robertson, 2012). According to Jordan Robertson in an interview given to Bloomberg (Yahoo Investigating Security Breach), it is not very embarrassing for a company like Yahoo because the stolen usernames and passwords were of mostly old and inactive accounts and the number 450,000 was not huge because it represented only a small fraction of people who were affected. A spokesperson from Yahoo also previously mentioned that these numbers only made up about only one percent of the total Yahoo active users (Chaykowski & Robertson, 2012). Robertson said that the humiliating factor was the susceptibility of a company like Yahoo through a method called SQL injection. This is because it only involved very basic security measures to be prevented and Yahoo’s inability to create such a security protocol was embarrassing. As a result of the whole security breach event, Yahoo closed at $15.69 in New York and its shares slid down by 2.7% in the same year (Chayko wski & Robertson, 2012). The Yahoo event did not only affect Yahoo Mail users but because its users signed up for the content writing website Contributor Network, the breach also resulted in retrieval of password for email accounts other than Yahoo such as Gmail, Hotmail, and AOL mail. One way this event could have been

Design Of Wifi Based Tdma Protocol Information Technology Essay

Design Of Wifi Based Tdma Protocol Information Technology Essay Time division multiple access is a multiple access method for shared the channel by dividing the signal into different time slots. TDMA is successful works in cellular mobile communication for several years ago. Recently has been combined with OFDM to introduce OFDMA. TDMA also ensure fairness between nodes in the network. In vehicular scenario, we proposed TDMA protocol to work with CSMA/CA to mitigate and cope with some of the challenges in vehicular communications. In this chapter we will discuss the design of the protocol, connection messages, protocol flow and cross intercommunication between the new TDMA sublayer with CSMA/CA and PHY layers. In section 3.2 a general explanation of proposed TDMA protocol, the design of Wi-Fi-based 802.11p is discussed in Section 3.3. In Section 3.4, implementations of TDMA protocol in the simulation environment is presented. Simulation problems and implementation improvements is discussed in Section 3.5. The chapter summarization is given in Sec tion 3.6. 4.2. EXPLANATIONS OF TDMA PROTOCOL The TDMA protocol is representing as a provider client protocol, which means the protocol is centralized. The other possibility is to define a distributed or an ad hoc protocol as it is done in (Fan Yu, 2007) and (Katrin, 2009). We mean by centralized that the provider will be the only one handles the information that has given in both channels. This does not mean that all communication is going to be only unidirectional (from the provider to the client), but sometimes is going to be bidirectional communication. The provider in our case here is the RSU (Road Side Unit) and the client/station is OBUs (Onboard Units). Form now we may always use the term RSU to provider or centralized node and the OBU to client or mobile station. Here we need to implement frame of 10 ms, those frame consist of two main time slots, one of them for the control and the second one for the service or data channel, and both are using different duration. Why we chose value of 10 ms because this is currently used in many TDMA implementations i.e. WIMAX. 4.3. DESIGN OF WI-FI BASED TDMA PROTOCOL IEEE802.11 has two modes DCF and PCF. Distributed Coordination Function (DCF) relies on CSMA/CA distributed algorithm and an optional virtual carrier sense using RTS and CTS control frames (IEEE Std 802.11, 1999). If the channel is busy during the DIFS (DCF Interframe Space) interval, the station defers its transmission. Point Coordination Function (PCF) is used for infrastructure mode, which provides contention-free frame transfer for processing time-critical information transfers (W. Wang, 2003). PCF is optional in the standard and only few vendors implemented it in their adapters. Two different periods defined at PCF mode: contention-free period (CFP) and contention Period (CP). CFP uses contention free-poll frames to give stations the permission to transmit. However, PCF has many drawbacks and limitations in long distance applications (i.e. up to tens of kilometers) this due to sensitivity of the acknowledgement (ACK) messages to propagation delay which is designed for contention -free local area networks purposes. Also, once a station reserves the access to the medium, it may occupy the medium for long time without any station can interrupt its transmissions even in the high priority traffics case; i.e. if the remote station has lower data rate due to the distance, then it will take long time to release the channel (Pravin, 2003). Consequently, it has been shown that (S. Sharma, 2002) (Sridhar, 2006) TDMA based MAC is suitable for long distance propagation delay. Most of the implemented solution for long distance Wi-Fi-based network was used WiMAX like TDMA frame for conducting the PMP scenario. However, using WiMAX/TDMA above Wi-Fi is increasing the system complexity and overhead since the WiMAX/TDMA has been built for the licensed-based and Wi-Fi is built with unlicensed environment. In this research a design of TDMA over the 802.11 is presented. The function of the proposed TDMA is to disable the contention behavior of 802.11 (CSMA/CA) for contention-less MAC. In this research a new cross layer design is introduced between CSMA/CA and new logical TDMA layer, which the Wi-Fi MAC frame is encapsulated in a logical TDMA header before forwarded to IP layer. The proposed protocol stack is shown in Figure4.1. The CSMA/CA peer-to-peer protocol is disabled and replaced with TDMA peer-to-peer protocol as shown with the dot-lines. Figure.4.1. Protocol flow of the TDMA-based PMP The logical TDMA header is added between IP header and MAC header. The function of the new header is to disable the random access feature of the CSMA/CA in 802.11 and replace it by logical TDMA function, which is maintains the synchronization of the local timers in the stations and delivers protocol related parameters. The frame is shown in Figure 4.2. The proposed TDMA header contains BCCH (broadcast control channel), FCCH (frame control channel) and RA (random access). BCCH: contains general information i.e. timestamp through time_stamp_update(), SSID, BS-node capabilities and random access time interval ra_interval(). All this parameters (except the RA time interval) is prepared and copied from the beacon frame (using beacon_content()) from the Wi-Fi MAC device driver. The BCCH information helps the APs in the sleep, wakeup, transmitting and receiving times. Figure.4.2. Additional TDMA header is added to Wi-Fi frame FCCH: carries the information about the structure and format of the ongoing frame i.e. scheduler () and time_slot_builder(); containing the exact position of all slots and Tx/Rx times and guard time between them and scheduling. RACH: contains a number of random access channels (RCH). This field is uses when no schedule has been assigned to the APs in the UL fields. Non-associated APs use RA for the first contact with an AP using slot_time_request(). The flow diagram of logical control and data channels is shown in Figure 4.3. Figure 4.3: the flow of the virtual channels for the TDMA frame, First, the RACH frame is receiving if there any connection request from APs to BS. Then, BCCH, FCCH and AGCH broadcast their information, then transmit and receive users payload. Timer is controlling all the transmitted and received signals. Although, the new TDMA header is introduced at the cost of the performance due to the overhead, however, in the long distance applications with point-to-multiple-point infrastructure scenarios usually the numbers of stations are not too high compared with end-user part. In our scenario we consider 4 remote access points and one central access point (BS-node). By implementing TDMA_module() each APs would assigned with time slot within the TDMA frame. TDMA also saves power because each STA only needs to wake-up during these time slots in each frame. If new node (AP) wants to join the network it listens to the BCCH frame to get the initial parameters from the BS-node. Then it uses the RA period to send time_slot_request() request to the BS-node to r equest for time slot. The BS-node uses the FCCH field to update the new scheduling table in scheduler(). The TDMA_module() assigns time slots for APs by taking copy of the NAV (network allocation vector) information (NAV_update()) from the Wi-Fi MAC layer and modifying it according to the schedule scheme. NAV is considered as virtual carrier sensing which is limits the need for contention-based physical carrier sensing. This is done by setting new back_off_counter() and NAV_new() in the TDMA_module() which indicates the amount of time that medium will be reserved for each time slots. The BS-node set the NAV value to the frame length time plus any other necessary messages to complete the current operation to make sure that no station (AP) will access the channel during the frame transmission. Other stations count down from the NAV to 0. When the NAV has nonzero value, the scheduler () send back to the Wi-Fi MAC that indication that the medium is busy; before the NAV reaches 0, the ba ck_off() and NAV_new() update the Wi-Fi MAC with the new NAV. The destination address (DA) and source address (SA) in the MAC frame header and in the SSID is modified according to the new NAV and RR scheduling information. Figure4.4 shows illustrate the flow of the process in cross-layer concept, which is consisting of three layers: TDMA source code, wireless driver and hardware abstraction layer (HAL). The cross layer is performed between wireless driver and the source code. HAL is different for each hardware platform. The procedure of this approach is also below: Core Module: Repoint the WiFi_MAC_SAP to TDMA_MAC Point the MAC-TDMA_SAP to IP TDMA_module() { //modify the NAV vector for virtual (fake) busy network busy If NAV() not_equal_to_zero then { //copy the NAV value to new place to use it for new AP Network_entry Copy CSMA/CA/NAV() to CSMA/CA/NAV_old() Copy TDMA()/NAV_new() to CSMA/CA/NAV() } If NAV()=0 then { // call NAV_update() TDMA/NAV_update() Set back-off counter() Send the NAV_new() to scheduler() } Scheduler(){ //using round robin queue scheme Round_robin() } //time_slot_builderà ¢Ã¢â€š ¬Ã‚ ¦ Time_slot_builder(){ random_access(){ // See if there are any time slot request If time_slot_request(){ Time_slot()++ } else traffic(); } } //add the new TDMA header // send the broadcast control channel (BCCH) bcch(){timestamp(); ra_interval; SSID;BS-node capability}; //for the RA using the same etiquettes used by contention period (CP) at the MAC level fcch() { slots_time_builder() Set frame_format(){ Slot_time_interval; } 4.3.1 TDMA Protocol Flowchart In Vehicular Environment The RSU sends the beacon frame periodically with the free slots available in the TDMA frame. The OBU scans for the RSU beacon. If more than one RSU respond, comparisons are made on their (received signal strength indicator) RSSIs and the best one is selected after which the order of merits are applied on the other RSUs as first, second, etc candidates according to their RSSI signal strength. The OBU uses the beacon to synchronize its frame with the RSU after which the OBU sends the data in the free slots (in the coming uplink frame). A check is performed to find if the RSSI Figure.4.4. Implementation and incorporating TDMA in 802.11p protocol stack. OBU scan for the RSUs Beacon frame More than one Beacon frame Are received No Compare the different RSSIs and select the best and > threshold Yes Synchronization and clock Exchange with RSU Send data in the free slots In the UL sub-frame RSSI No Yes Figure4.5 TDMA Protocol Flowchart The TDMA frame structure is shown in Figure4. 3. The TDMA frame encapsulates the 802.11 frames in the payload subsection. The frame is repeated periodically for every 20msec (which is the length of the frame). Each frame contains the beacon filed, i.e. the broadcast control channel (BCCH) which comprises timestamp, SSID, and BS-node capabilities. The frame also contains the frame control channels which carries information on the structure and format of the ongoing frame, i.e. the slots scheduler which contains the exact position of all the slots and the Tx/Rx times and guard times. The GACH and the RACH are used for random access channel when the OBU needs to join the WBSS. The RACH is the channel that the OBUs use for association request. The GACH is the grant access channel that contains all the OBUs accepted for transmission in the next frame. The TDMA is using transmission opportunities (TXOPs) mechanism originally provided by the IEEE 802.11e to calculate the DL and UL time slots duration. The TXOP is a predefined start time and a maximum duration for the station to access the medium. A RSU will set its own NAV to prevent its transmission during a TXOP that has been granted through the OBU (Figure4. 6). Rather than categorizing the data traffic based on the voice, the data and the video as in the 802.11e, the data traffic priority categories are based on the OBUs channel quality. The RSU gives high priority to vehicles with high speed to send more frames before it leaves the WBSS. The vehicle with the high channel fading will get more number of slots. Of course, this mechanism will introduce performance anomaly, however, we can use any of the solutions available in the literature for the performance anomaly (Tavanti, 2007) (IEEE P802.11p/D3.0,2007). DCD feedback TDMA DCF EDCA PMD and PLCP Figure4.6 Channel fading parameters feedback for vehicles transmission priority and TXOP setting. 4.4. IMPLEMENTATIONS OF TDMA PROTOCOL IN THE SIMULATION ENVIRONMENT In the previous section, we theoretically describe the main characteristics of the protocol which we want to design. This section explains how we implemented the ideas of this thesis by the modification Code of C++ in the Network Simulation. Although the protocol that we want to design is basically a protocol of MAC, we have to put in mind that is not only changes to be made in the MAC layer will be done. We will also have to deal with the physical and application layer. From the point of view of the provider of MAC layer is the one which is responsible to handle the various types of packages (from service and control channel). In fact, the MAC layer in the side of the provider is the one which carries the multiplexing of TDMA between the two channels (and also between various services to the interior of the channel of the service). The application, in this case, will produce the packages which will be presented in each channel. From the point of view of the client layers, MAC and application are simple. The MAC layer basically responsible; to send to application the packages which the client wants to receive (packages which belong to the channel or from desire service) or throwing the packages that not requested by the client (packets from a broadcast or unicast service the client is not interested in). The application layer will be the one that which produces the packages of the request from clients to send to the provider when they are interested by a service unicast. Well as we described in detail the characteristics of the MAC protocol designed earlier, we may carry out this idea described theirs corresponds to the last version of our protocol, to reach this execution that we programmed and examined before simple versions, the changes of the force and improvements made between the versions are related to the definition of the various services offered in the section of channel service: The first version only considered a unidirectional communication between provider and client. The reason was that we only define broadcast services in the service channel. A second version consisted in defining unicast services and hence introducing a bidirectional communication between provider and client. This new version was more complex than the previous one so we decided to divide the application we had until now (called pbc3) into two sides: the application in the provider side (pbc3) and the application in the client side (pbc3Sink). This idea of defining two sides of an application or protocol layer (to simplify its implementation) is already used in other applications or protocol layers included in the simulator as TCP. The third and last version consisted in implementing the algorithm which handles the access of more than one client to the same unicast service. This was not considered in version two. When we are programming our MAC protocol, several problems raised, which are not only in our side, but also of the limitations or the restrictions of the Network Simulation. Well, in the next section4.5 we describe and explained all, it is worth to mention a principal limitation in so much it deeply influenced the execution of our protocol. The limitation comes like more parallel flow of the data in the same node started to appear (the node can be client or provider). In our case we decided to have only one provider, this provider will produce the data of both services. This means that the provider will have more application to the function in parallel and more file test in the MAC layer (see Figure 3.2), each one associated to a different data flow. That is the reason why we are interested in parallelizing. The problem is, in so far as we know, installing parallel flows in same node; is not a task easy to make in the simulator. The most common solution is composed to use nodes as parallel flows as much of an idea used when a protocol stack is defined on the two aircraft or more (like the plan of the data and management represented on Figure 2.3). This is Explained in (GMPLS, 2006), or when we wish to have a node of multi-interface, in (NS2 Notebook). The idea is: if we cannot have more than one application function in parallel in the same node, what would be the possible solution? The answer to that, like also accentuated in section4.5, is to have only one application to function in the provider, which produces various types of packages according to the time execution. This approximation also solves the problem to have more than one queue (in parallel) in the MAC layer. We will not need various queues to store various packages due to these packages arrive at the MAC layer already in the order; they must be sent. This solution simplifies the definition of the MAC layer but made the definition of the application layer to be more complex. Although the solution taken could seem rudimentary; the fact is that the difference between the theoretical solution and rectifies is not also large particularly when to think that what we want with once examine with the protocol is implemented. After the mention and explanation of this problem we can now specify how the protocol was made. We will start to explain how application is defined in all both, client and provider. Both sides application have two principal functions: one is responsible for creation and sending of the packages to the lower layers and the other is responsible to receive the packages of the lower layer. The application in the side of the provider calls the pbc3 and has two principal functions: one for send and other for receive frame. While sending the frame we basically have to create a package (by defining its title) and send it. The provider will send various types of packages according to the execution time. Basically we will have two types of packages: the packages of management in the control channel of inspection mark and the packages of the data in the excavation of service of the channel timeslot. These packages will have various headers. In case of the packages of the zones information of the header are as in Figure 4.7: Type Service_id Time_slot seqNum lastPacket node_id Send_time Payload Figure 4.7: Fields of the application header for data frames. Service_id: Field used by the provider to indicate the service whose payload is included in the frame. Time_slot: Field that shows the subtime slot when the service is offered. SeqNum: Sequence number of the packet sent. Nowadays is only used in data packets which belong to unicast services, it is used by the provider when more than one client want to receive the same private information. LastPacket: This field is related to seqNum. It is used to indicate that the packet sent is the last one. In case of management frames the header is defined by the following fields in Figure 4.8. Type Services_ Num_services node_id Send_time Payload Information Figure4.8. Fields of the application header for management frames. services_information: It is only used in management frames. It is a vector which contains the basic information about the services offered by the provider. This basic information is defined by three fields: the first field is the identifier of the service, the second field is the subtimeslot identifier and the third field is the type of the service (as we said already before the type of the service means if the service is broadcast or if it is unicast). These three fields must be defined for each service available in the provider, the Figure 4.9 shows that. Service 1 Time Slot where Type of Service 1 Service 2 Time Slot when Type of service 2 Identifier Service 1 is offered Identifier Service 2 is offered Figure 4.9: Example of the services_information buffer when two services offered. Although in our implementation the identifier of the service and the identifier of the timeslot is the same (which means the service whose identifier is the number one will be offered in the subtime slot number one), we decided to define two variables because they would have different values in future versions of the protocol. Num_services: Value used to indicate the total number of services which are going to be offered by the provider during the service channel timeslot. Once we have explained how our application works in both sides (provider and client) we must explain the main changes done in the MAC layer. When we download the NS2.33 version there was already included an implementation of IEEE802.11a protocol. We didnt want to make use of this code because it was totally oriented to guaranty the CSMA/CA with virtual carries sense mechanism, we are not interested in. there was also simple TDMA implementation included. We decided to adapt into our requirements. We basically had to change the definition of the TDMA frame and to set up both data and management MAC headers. In contrast to the application layer there are no variables defended to make use of the MAC layer through the Tcl script. If we concentrate on the physical layer, we will see that in our version of Network Simulation NS2, there were already two physical layers for wireless communications applied: the first one called the wirelessPHY and the second one called WirelessPhyExt. We are interested to use this last version of the physical channel basically it presented an important concept for us: it supports multiple arrangements of the modulation. WirelessPhyExt leaves the function with BPSK, QPSK, QAM16 and QAM64 as it is described in (Qi Chen, 2008). The modulation influences certain important characteristics such as the rate of header information and minimum sensitivity of the receiver, according to the indications the Figure 3.3 of, and consequently the period of the data of transmission and SINR necessary to receive it and to decode it. The only problem is that this new version of the wireless channel must be used together with an extension of the MAC layer called Mac802_11Ext. We were not interested in using that one for the same reason we were not interested in using the Mac802_11 version; and for that we decided to introduce the multiple modulation schemes in the WirelessPhy layer. Another important point when working low layers of the WAVE protocol stack is to think about how the channel is modelled in NS2. There are four different types of channel propagation defined and include in NS2.33, The free space model, the Two-Ray Ground reflection model, the Shadowing model and the Nakagami model. The first three models are well described in (The NS manual, 2008). 4.5 SIMULATION PROBLEMS AND IMPLIMENTATION IMPROVEMENTS Here we explained the reason for which we are interested to study the technology of TDMA in the V2I communications and the process followed to define and apply our protocol. By creating a new protocol, sometimes it is not possible to design the theoretical idea that we had because of some limitations presented by the simulator. It is also possible that our execution could be improved at the points given. We must realize that although the protocol seems to be complex sometimes, many improvements could be made to obtain the best and more specific results. The idea of this section is just to explain the main problems found when elaborating our protocol and to suggest some future improvements. If we refer first to the problems found when we were working we must clarify that most of them are not really problems (in the sense of bugs found when executing the protocol) but limitations the simulator has which do not allow us to define the protocol as we wanted to. There are three main limitations we want to point out: The first is already mentioned in the previous section. The problem is related to the parallel data flows in a node. We were interested by this fact of being able not only to have more application to the function in parallel in the same node (as explained in the section 4.4) but to also define the two planes of protocol, data and planes of management, in the same node (that we can see Figure 2.3) although this last idea was thrown it required of much work to make. In section 4.4 we adopted easy and the fast solution which does not have affected the results obtained. But there is other solutions, simplest is composed to define nodes as many, in the code of TCL, as data flows we need and link these nodes through a router. To explain it easily: we will have one node per each data queue (see Figure 3.3) and one router that handle the information from each node. This solution is based in the actual implementation of the Diffserv queues in the NS (Definition of physical queues) where virtual and physical queues are used (Implementing multiqueue). In our case we will need at least two nodes: one for the data of the control channel and the other for the data of the service channel, in case only one service is offered. We must realize this solution involves changes in the Tcl code which leads to a simple C++ implementation. Another solution, which could be considered as an improvement is to have only one application running on the provider that generates different types of packets but instead of doing it as a function of the execution time, it could generate them randomly and give the work of organize them to the link layer. In this case we will need to define an algorithm in charge of finding the desired packets in the unique queue that exists in the link layer and sending them in the correct order to the MAC layer. There is a third solution which allows having an implementation closer to the one specified in the standards ((IEEE 802.11, 2007) and (Implementing multiqueue)). The idea consists of adapting the definition of the queue done nowadays in the implementation 802.11e standard which is included in the simulator. As we can see in (Design and verification, 2003) this implementation requires changes in the definition of the class queue which allows having multiples queues by creating them in an array (Evaluation of IEEE 802.11e). The source code of this new type of queue can be found in (Evaluation of IEEE 802.11e). The second limitation is related to the synchronization of the nodes. Those nodes can be an OBU or a RSU. The NS is a simulator based in events controlled by timers. The fact is, as it is pointed out in IEEE 1609.4 standard in (Yunpeng, 2007) all the nodes require to be synchronized before communication. The synchronization is especially important when using TDMA technology and it is a process which will be carried on when any OBU enters in the communication area of a new RSU in a centralized system. The fact is that in the NS tool all the nodes implemented (in the Tcl code) have the same time basis which means they do not need any synchronization because they are already synchronized. If we are interested in defining the synchronization process we should first desynchronize the nodes by manipulating their timers. In our case we will consider the RSU time basis to be the one the other nodes must to synchronize on. Each OBU will have to follow a synchronization process before receiving data frames from the RSU. The idea could be the following: the first time an OBU receives frames from a new RSU it gets the timestamp of the RSU and, after adding the delay produced by the propagation of the frame to this timestamp, adjusts its timers. Calculate the delay or time difference between the RSU and the OBU is not complicated. The only idea which does not seem clear is how to set up different time basis in the nodes. The third and last limitation is related to the anti-collisions mechanism used in the MAC layer mainly based in CSMA/CA algorithm. We detected the problem when executing our code: we found there were collisions between request frames when a considered number of OBUs were interested in receiving information about the same unicast service. Those collisions should not take place if we keep in mind each node is supposed to be able of sense the medium to see whether it is busy before sending any kind of frame. Why this type of collisions is produced? As we explained earlier, it is necessary to present intervals of guard to the end of each time slit to avoid collisions between the reinforcements produced by various devices (OBUs and RSU in our case) but in this case the collisions due are produced to different OBUs send braces of request really narrowly in time and, because of them cannot detect if the medium is with vacuum or not, a collision is produced and detected by the RSU. When working with the NS tool we are not able to do all the things we want to, not only because of some restrictions or limitations the tool has (as we explained before) but also because of time we did not implement all the ideas which came to our mind and we must simplify and focus our work. Because of this lack of time there exist a lot of points in our protocol which could be improved. Some of these points are explained in the following paragraphs. If we focus in the implementation of the control channel the most important improvement which could be done is to introduce critical frames and implement the process each node has to follow when receiving those frames. Introducing those types of frames will be really interesting because we can see how to handle both types of information (critical and no critical) and we would make a better use of the control channel than we do in our actual implementation. If we pay attention to the service channel there are some things which could be improved, the ideas are summarized in the following points: In the actual implementation there is not any prioritization between nodes, which means when two or more nodes want to receive the same information (which is unicast) the first who ask for it is the first which receives the data. One possibility is to define the priority as a function of the position of each OBU with respect to the RSU. It sounds coherent to give higher priority to the nodes that are closer to the RSU because of their small latency (time necessary to consume a service). Basically the latency is smaller because the propagation time (one of the terms