Frequency modulation the amplitude

Frequency modulation the amplitude INTRODUCTION In frequency modulation the amplitude is kept constant and the frequency is modulated by the amplitude of the modulating signal. The modulation index for fm is m = maximum frequency deviation/modulating frequency. FM signal can be represented as:- v = ac sin(wct + m sin wmt ) ABSTRACT Frequency modulation is a type of modulation where the frequency of the carrier is varied in accordance with the modulating signal. The amplitude of the carrier remains constant. The information-bearing signal (the modulating signal) changes the instantaneous frequency of the carrier. Since the amplitude is kept constant, FM modulation is a low-noise process and provides a high quality modulation technique which is used for music and speech in hi-fidelity broadcasts. In addition to hi-fidelity radio transmission, FM techniques are used for other important consumer applications such as audio synthesis and recording the luminance portion of a video signal with less distortion. There are several devices that are capable of generating FM signals, such as a VCO or a reactance modulator. Frequency Modulation is abbreviated FM. Definitions An important concept in the understanding of FM is that of frequency deviation. The amount of frequency deviation a signal experiences is a measure of the change in transmitter output frequency from the rest frequency of the transmitter. The rest frequency of a transmitter is defined as the output frequency with no modulating signal applied. For a transmitter with linear modulation characteristics, the frequency deviation of the carrier is directly proportional to the amplitude of the applied modulating signal. Mathematical Analysis of FM As was done with AM, a mathematical analysis of a high-frequency sine wave, modulated by a single tone or frequency, will be used to yield information about the frequency components in an FM wave, FM power relations, and the bandwidth of an FM signal. From the definition of frequency deviation, an equation can be written for the signal frequency of an FM wave as a function of time: fsignal = fC + kf eM(t) = fC + kf EM sin?Mt And substitution of d = kf EM yields: fsignal = fC + d sin?Mt But what does this equation indicate? It seems to be saying that the frequency of the transmitter is varying with time. This brings up the same type of problem that was observed when we looked at a time display of AM and then performed a mathematical analysis in an attempt to determine its frequency content. With AM, the signal appeared to be a sine wave thats amplitude was changing with time. At the time, it was pointed out that a sine wave, by definition, has a constant peak amplitude, and thus cannot have a peak amplitude that varies with time. What about the sine waves frequency? It also must be a constant and cannot be varying with time. As was the case with AM, where it turned out that our modulated wave was actually the vector sum of three sine waves, a similar situation is true for FM. An FM wave will consist of three or more frequency components vectorially added together to give the appearance of a sine wave thats frequency is varying with time when displayed in the time domain. A somewhat complex mathematical analysis will yield an equation for the instantaneous voltage of an FM wave of the form shown here: eFM(t) = EC sin(?Ct + mf sin?Mt) where EC is the rest-frequency peak amplitude, ?C and ?M represent the rest and modulating frequencies, and mf is the index of modulation. This equation represents a single low-frequency sine wave, fM, frequency modulating another high-frequency sine wave, fC. Note that this equation indicates that the argument of the sine wave is itself a sine wave. The Index of Modulation The index of modulation, mf, is given by the following relationship: A few more comments about the index of modulation, mf, are appropriate. As can be seen from the equation, mf is equal to the peak deviation caused when the signal is modulated by the frequency of the modulating signal; therefore, mf is a function of both the modulating signal amplitude and frequency. Furthermore, mf can take on any value from 0 to infinity. Its range is not limited as it is for AM. FM Power Relations Recall that for an FM wave the amplitude of the signal, and hence the power, remains constant. This means that the power in the individual frequency components of the wave must add up to the transmitter output power. Furthermore, if the modulation index changes, the total power must redistribute itself over the resulting frequency components. If there is no modulation, then mf = 0 and J0 = 1.0. Mathematically, this can be shown by the following: Prest freq = J0 power 2 Ptrans or Prest freq = Ptrans for mf = 0.0. To determine the power for any individual frequency component, we can use the following relation: Pn = Jn 2(mf) Ptrans 4.11 Furthermore, the total signal power will be given by: Ptotal = (J0power2 + 2J1power2 + 2J2power2 + 2J3power2 + ) Ptrans. The Effect of Noise on FM Recall AM and the effect of noise on it. Random electrical variations added to the AM signal altered the original modulation of the signal. For FM, noise still adds to the signal, but because the information resides in frequency changes instead of amplitude changes, the noise tends to have less of an effect. Expanding upon this idea a bit, one notes that the random electrical variations encountered by the FM signal will indeed cause distortion by jittering the frequency of the FM signal. However, the change in frequency modulation caused by the jittering usually turns out to be less than the change in the amplitude modulation caused by the same relative amplitude noise variations on an AM signal. Also unlike AM, the effect of the frequency jittering becomes progressively worse as the modulating frequency increases. In other words, the effect of noise increases with modulation frequency. Pre-Emphasis and De-Emphasis To compensate for this last effect, FM communication systems have incorporated a noise-combating system of pre-emphasis and de-emphasis FM Generation Techniques FM signals can be generated using either direct or indirect frequency modulation. Direct FM modulation can be achieved by directly feeding the message into the input of a VCO. For indirect FM modulation, the message signal is integrated to generate a phase modulated signal. This is used to modulate a crystal controlled oscillator, and the result is passed through a frequency multiplier to give an FM signal DIRECT FM GENERATION The simplest method for generating FM directly is to vary the frequency of an oscillator. A capacitance microphone or a varactor diode may be used as part of the oscillators frequency determining network. The capacitor microphones capacitance varies in response to the intensity of the sound waves striking it, making the oscillators frequency vary as the amplitude of the sound varies. The varactor diodes capacitance depends on the voltage across it. Audio signals placed across the diode cause its capacitance to change, which in turn, causes the frequency of the oscillator to vary. INDIRECT FM GENERATION While it is not possible to vary the frequency of a crystal oscillator directly, it is possible to vary its phase. The resulting PM signal can be used to create FM. This is the basis of the Armstrong modulator.The mathematics required to analyze the Armstrong modulator completely are complex, so we will discuss only the basic circuit operation. An audio signal is passed through a preemphasis network and then an integrator, a special network whose output is the time integral of the input signal.. In this way an FM signal is generated.The Armstrong modulator cannot produce much deviation, so combination of multipliers and mixers are used to raise the carrier frequency and the deviation. The multipliers are used to multiply the carrier and the deviation. The mixers are used to decrease the carrier, while keeping the deviation constant so that additional multiplier stages can be used to obtain more deviation. FM Performance FM Spectrum A spectrum represents the relative amounts of different frequency components in any signal. Its like the display on the graphic-equalizer in your stereo which has leds showing the relative amounts of bass, midrange and treble. These correspond directly to increasing frequencies (treble being the high frequency components). It is a well-know fact of mathematics, that any function (signal) can be decomposed into purely sinusoidal components (with a few pathological exceptions) . In technical terms, the sines and cosines form a complete set of functions, also known as a basis in the infinite-dimensional vector space of real-valued functions (gag reflex). Given that any signal can be thought to be made up of sinusoidal signals, the spectrum then represents the recipe card of how to make the signal from sinusoids. Like: 1 part of 50 Hz and 2 parts of 200 Hz. Pure sinusoids have the simplest spectrum of all, just one component: In this example, the carrier has 8 Hz and so the spectrum has a single component with value 1.0 at 8 Hz . The FM spectrum is considerably more complicated. The spectrum of a simple FM signal looks like: The carrier is now 65 Hz, the modulating signal is a pure 5 Hz tone, and the modulation index is 2. What we see are multiple side-bands (spikes at other than the carrier frequency) separated by the modulating frequency, 5 Hz. There are roughly 3 side-bands on either side of the carrier. The shape of the spectrum may be explained using a simple heterodyne argument: when you mix the three frequencies (fc, fm and Df) together you get the sum and difference frequencies. The largest combination is fc + fm + Df, and the smallest is fc fm Df. Since Df = b fm, the frequency varies (b + 1) fm above and below the carrier. A more realistic example is to use an audio spectrum to provide the modulation: In this example, the information signal varies between 1 and 11 Hz. The carrier is at 65 Hz and the modulation index is 2. The individual side-band spikes are replaced by a more-or-less continuous spectrum. However, the extent of the side-bands is limited (approximately) to (b + 1) fm above and below. Here, that would be 33 Hz above and below, making the bandwidth about 66 Hz. We see the side-bands extend from 35 to 90 Hz, so out observed bandwidth is 65 Hz. You may have wondered why we ignored the smooth humps at the extreme ends of the spectrum. The truth is that they are in fact a by-product of frequency modulation (there is no random noise in this example). However, they may be safely ignored because they are have only a minute fraction of the total power. In practice, the random noise would obscure them anyway. Frequency Response Frequency response is a specification used in amplifiers, pre-amplifiers, CD players, tape decks and other audio components to measure how uniformly it reproduces sounds from the lowest tones to the highest. An amplifier or other component should preserve the loudness relationship between various instruments and voices and should not over or under-emphasize any frequency or tone. This is known as flat frequency response. Bandwidth As we have already shown, the bandwidth of a FM signal may be predicted using: BW = 2 (b + 1 ) fm where b is the modulation index and fm is the maximum modulating frequency used. FM radio has a significantly larger bandwidth than AM radio, but the FM radio band is also larger. The combination keeps the number of available channels about the same. The bandwidth of an FM signal has a more complicated dependency than in the AM case (recall, the bandwidth of AM signals depend only on the maximum modulation frequency). In FM, both the modulation index and the modulating frequency affect the bandwidth. As the information is made stronger, the bandwidth also grows. Applications of frequency modulation: Broadcasting: FM is commonly used at VHF radio frequencies for high-fidelity broadcasts of music and speech . Normal (analog) TV sound is also broadcast using FM. A narrow band form is used for voice communications in commercial and amateur radio settings. The type of FM used in broadcast is generally called wide-FM, or W-FM. In two-way radio, narrowband narrow-fm (N-FM) is used to conserve bandwidth. In addition, it is used to send signals into space. Sound: FM is also used at audio frequencies to synthesize sound. This technique, known as FM synthesis, was popularized by early digital synthesizers and became a standard feature for several generations of personal computer sound cards. Radio: An example of frequency modulation. This diagram shows the modulating, or message, signal, xm(t), superimposed on the carrier wave, xc(t) The modulated signal, y(t), produced from frequency-modulating xc(t) with xm(t). A Method of Reducing Disturbances in Radio Signaling by a System of Frequency Modulation called radio FM. As , wideband FM (W-FM) requires a wider signal bandwidth than amplitude modulation by an equivalent modulating signal, but this also makes the signal more robust against noise and interference. Frequency modulation is also more robust against simple signal amplitude fading phenomena. As a result, FM was chosen as the modulation standard for high frequency, high fidelity radio transmission: hence the term FM radio (although for many years the BBC called it VHF radio, because commercial FM broadcasting uses a well-known part of the VHF band; in certain countries, expressions referencing the more familiar wavelength notion are still used in place of the more abstract modulation technique name).A high-efficiency radio-frequency switching amplifier can be used to transmit FM signals (and other constant-amplitude signals). For a given signal strength (measured at the receiver antenna), switching amplifiers use less battery power and typically cost less than a linear amplifier. This gives FM another advantage over other modulation schemes that require linear amplifiers, such as AM and QAM. REFRENCES; http://en.wikipedia.org/wiki/Frequency_modulation http://www.tech-faq.com/frequency-modulation.shtml http://www.fas.org/man/dod-101/navy/docs/es310/FM.htm http://www.answers.com/topic/frequency-modulation

Chinas Economy Essay

Discuss the possible implications of such a development for (a) the world trading system, (b) the world monetary system (c) the business strategy of today’s European and U. S. global corporations, and (d) global commodity prices. A) The implications of such a development for the world trading system is that China will basically will be the root of trading. From my perspective, China’s growth of economic will benefit overall economy of world. In the trading system, China will play a major role on deciding the policy and implications how the trading should be done. With its sophisticated export increase do to the rapid increase in technology; China is sharply stepping up exports. With China’s dominant imports and exports trading and taking a big part in WTO, trade as a percent of GDP has grown dramatically, rising to a level far greater than for any country of similar size. B) With its high output of economic growth, in world monetary system, I think China’s currency might be powerful than U. S. dollar or equal or more than other world currency. In monetary system, China’s demands for its large economic development, will put pressure on other global countries how its plays a leading role. The Chinese Yuan will be in the near future a major international currency, benefitting from the strong position and of the Chinese economy and the latest arrangements, and the stability of the Yuan’s value when it is compared to other major currencies. C) The implications in European and U. S. lobal corporations would be from my perspective that more corporation business will shift to China. With so many corporation works being sent overseas, there is no doubt that China will be leading part in these corporations. China will generally set polices in what is better interest for corporation and China’s economic growth. I think that business strategy will be more controlled by China do to the resources that it’s going to provide and how it will be distributed th roughout the global economy. D) I think this is going to be the most impact throughout the whole world with economic growth of China. Global commodity price changes can affect inflation and the terms of trade at the global level, with possibly large effects on other emerging and developing economies. In upcoming growth, China will set benchmarks in commodity pricing along with U. S. at side. Chapter 2 question 4 What are the risks facing foreign firms that do business in Indonesia? What is required to reduce these risks? The risks that I personally believe firms that do business in Indonesia would be loss of income to bribes. Moreover, jail time for foreign enterprises on flimsiest of pretext as well and long waits to establish a business are the risks that foreign firms are facing. In order to reduce or say minimize these risks, a radical change is required. Indonesia has an anticorruption drive, which may or may not work. As stated in the case, Indonesia has launched an anticorruption drive; it just needs to implement better ways of putting that law into affect. A more assertive policy needs to take affect on people in order to make the country better and bring out the resources that it has to offer like Oil production. Moreover, political elites need to get involvement with each other and foreign countries in shaping and assisting to rebuild a better Indonesia. As for business firm, businesses must take a pro-active approach to security and risk management. Doing so reduces the chances of a company becoming a victim, but also minimizes the likely fallout in the event an incident was to occur. An effective risk prevention and mitigation plan will enable the company to effectively respond, recover and resume normal business operations within the shortest time frame possible so as to minimize the potential business impact either financially or from a reputation standpoint.

Vietnam War and the Media

Write an essay that offers a critical examination of the concept of the ‘guilty media’ thesis in respect of any war of your choice Natasa Perdiou The Vietnam War was the first war that allowed uncensored media coverage resulting in images and accounts of horrific events that served to shape public opinion of the war like nothing that had been seen before. This portrayal by the media led to a separation between the press and the U. S. government, as much of what was reported defied the intentions of government policy.The media has fell blame by many for the result of the war, as it is widely believed that the war could not have been won under the scrutiny that came from the American people as a result of the media coverage. From the beginning of the Vietnam War to the present, the media has been an immeasurable factor in the perception of the war as the stories, true or false, that were reported gave the American people a face to an ugly war. The question over how much, i f any, the media had affected the outcome of the war has been an unrelenting one and is likely to continue for a long time to come.But one fact that cannot be doubted is that the dreadfulness of war entered the living rooms of Americans for the first time during the Vietnam War. For nearly a decade the American public could watch villages being destroyed, Vietnamese children burning to death, and American body bags being sent home. Although early coverage mainly supported U. S involvement in the war, television news dramatically changed its frame of the war after the Tet Offensive. Images of the U. S led massacre at My Lai dominated the television, yet the daily atrocities committed by North Vietnam and the Viet Cong rarely made the evening news.Moreover, the anti-war movement at home gained increasing media attention while the U. S soldier was forgotten in Vietnam. There was a stable build up of US military support activity in Vietnam during the period 1954 to 1965, but the first c ombat troops did not emerge until March 1965. During this period, media attention in the war was slow in building up, the first resident TV correspondent, NBC’s Garrick Utley, only arriving in late 1964. The media did build up and as the war became progressively more aggressive, journalists were sent out in increasing numbers.It would be fair to say that reporting of Vietnam increased approximately in proportion to the military presence. Prior to the involvement of ground troops in Vietnam, media coverage was concentrated to the political dimension of the war of stabilizing a non-communist regime in South Vietnam. The media at this time was committed to reporting news that reflected the common anti-communist stance, which was so † powerful in the early 60's that as long as the Vietnam War remained small, the administration had little trouble with the press† (Hallin 28). [4]By 1965 media coverage of Vietnam increased as the U. S. was becoming more part of an aggres sive war. Reporting began to shift from the intention of eradication the world of communism to the frustration of the men in the field. After the heavy use of ground troops, a shift in coverage occurred that â€Å"put much of the attention on the military situation† of the war. (Wyatt 133). [9] An increasing number of reports began to emerge about a lack of incentive and motivation on the part of the South Vietnamese troops. This brought to question the whole role of American interference, as the U.S. was proposed to support the South Vietnamese in their effort against the North, not the other way around. 1965 did not only mark the increase of ground troops into Vietnam, it also brought the emergence of television into the realm of media coverage, while the government was trying to maintain the idea that that the U. S was making encouraging progress, that the Vietnam War was necessary and that victory was not inevitable. While a small percentage of coverage was dedicated to w arfare and death, what was seen was not forgotten by the American people.The famous General William Westmoreland states that â€Å"[the coverage was] almost exclusively violent, miserable or controversial; guns firing, men falling, helicopters crashing, buildings toppling, huts burning, refugees fleeing, women wailing. A shot of a single building in ruins could give the impression of an entire town destroyed. † [7] So, in spite of continuous reports of victory, the public had a hard time coming to grips with what they saw their troops involved in Vietnam. Such coverage, along with the vivid images that emerge on T. V. ed to a serious rise in anti-war protest that was merely strengthened by the events of 1968. The Tet Offensive of 1968 marked the greatest conflict in beliefs of the United Stated government and the media. In January, North Vietnamese troops attacked the North cities of South Vietnam and the U. S. embassy in Saigon. The media and the television, however, portray ed the attack as a brutal defeat for the U. S, totally altering the outcome of the war at the very moment when government officials were publicly stating that victory in Vietnam was â€Å"just around the corner† (Wyatt 167)[8].The media covered all the events that immediately followed the Tet Offensive and the American public began wondering whether this war could be won. Don Oberdorfer a Washington reporter said that â€Å"there’s no doubt Tet was one of the biggest events in contemporary American history, within two months the, American body politically turned around on the war. And they were significantly influenced by events they saw on television†. [2] The Tet offensive was not totally unpredicted by the US military.In reality, the final result was a success, in military terms, for the US as the Vietnamese did undergo serious casualties and were driven back. However, the America media were not expectant of the attack and assumed that the military did not ei ther. Seeing the US embassy being undertaken by the Vietnamese presented the event as a defeat, ‘television fell prey to its chronic lust for drama. ’[1] After the Tet offensive the media began to attack the American involvement in Vietnam.It became clear to the American public that there was no clear way to win the war. Also, in reaction to public mood the media started sending damaging reports from the frontlines; they suggested that American troops lacked the specific training for the terrain and the type of warfare they were subjected to. They also gave the idea to people that the new rebellious generation and the great pressures of the war meant that many soldiers were drug abusers and carrying out atrocities. The media concentrated on civilian casualties and incidents such as the one in My Lai,These images on people’s televisions, left people in outrage, many had lost faith in the war and saw no military plan capable of wining such a war. They were outraged by their country’s conduct in the war and were set into a moral panic, seeing brutal scenes of civilian casualties committed by their own troops. The war was now seen as a shameful one and the government was seen to be at fault, forcing many young men to their death or to commit the atrocities they saw on their TV screens.The former Vietnam correspondent Robert Elegant of the Los Angeles times said that â€Å"for the first time in modern history the outcome of a war is seemed destined to be determined not on the battlefield but on the printed page and, above all, on the television screen† [3] The reporting of the actual war was deteriorating, just at the moment when the American military advisers hoped to push for victory. The North Vietnamese causalities following the Tet offensive had left them vulnerable and it was expected that an immediate attack to cut the Ho Chi Minh trail would permit the US troops the chance for total success.The news, though, was almost tota lly concentrating on the rising anti-war division in the US and stories of low morale and indiscipline among the US troops. The media were responsible for the American withdrawal from Vietnam because of the poor quality of reporting which lacked in validity in its facts about events and incidents in the war. It seems with all these misreports or blatant lies, which was meant to purposely damage the image of the American fighting forces in Vietnam public opinion of the war was very low in America. However the question is to what extent, if any, did this coverage change the outcome of the war?It would be reasonable to suggest that the Tet offensive was the most significant incident in shaping the outcome of the war. The media certainly reported the assault in the most inaccurate way for the US army. Activist young journalists, who had not in the past witness any real fighting were all of a sudden bounded by fighting supposed that the North Vietnamese had won a great victory. The US go vernment and army were to a degree guilty since they were aware the assault was going to happen and did not inform the media for reasons of national security.There was a succeeding recovery by the Americans and the media did not report this. Moreover, fragile leadership, mainly from Lyndon Johnson, did not motivate confidence in the war effort. Evidence does also indicate that there was no absolute public support for the war, even earlier than the negative coverage by media began. The reasons for the war, to ceased the spreading of communism (the Domino Theory), were not clearly demonstrated and maintained. Some Americans began to realise that the Communist threat was used as a scapegoat to hide imperialistic intentions.After the media’s massive blunder of reporting the Tet offensive as a major psychological defeat, and not having the sophistication, integrity or courage to admit their error opposition to war rose sharply. These innumerable domestic divisions gave the chance to high ranking members of Johnson’s administration to begin expressing their disapproval of Johnson’s actions to the media. This put pressure on government into engaging in to a more defensive military strategy that may have altered the likelihood of victory for the US.President Johnson was under fire from anti-war ‘doves’ and submitted to both ceasing the bombing of North Vietnam and beginning the Paris Peace talks. As expected, he also announced his decision not to stand for re-election. To make things worse, the war cost two-thousand-million dollars every month. The price of many goods in the United States began to rise. The value of the dollar began to drop. The result was inflation. Then economic activity slowed, and the result was recession. Opposition to the war and to the Administration's war policies led to bigger and bigger anti-war demonstrations. Johnson’s successor, Richard Nixon, in an effort to gain the public support back announced a plan of ‘Vietnamization’ of the war. This involved swapping US troops with more South Vietnamese troops, trained and armed by the US, after the first US troop withdrawals from Vietnam started in June 1969. Unluckily for Nixon, this did not discourage the anti-war protest who demonstrated in record numbers (250,000) in Washington in November 1969. [10] Images in television in every living room in America were showing the true dreadfulness of war for the first time.Reports of military failure (especially Tet) and slaughter such as the My Lai event shaped an air of scepticism. The media at home were also reporting the rising number and intensity of anti-war protest, legitimising opposition to war. A thing television was guilty of was only placing emphasis on the US troops. The stories that made the news were always about US troops in combat, US troops doing civil action, sometimes US troops in trouble (desertion, drugs, fragging). The allies, whose losses (280,000 South Vietnamese dead) far exceeded those of American troops, were invisible to the American crews.This gave the American public the feeling that the war was being waged mostly by the Americans and it was probably this, more than the almost exclusively violent coverage which gave the public a sense of disillusionment and war weariness. Additionally, media coverage of the war in Vietnam shook the faith of citizens at home. The media was the catalyst, which promoted the rising American anti-war movement. They were to a great degree accountable for the American troops’ withdrawal from Vietnam because of its poor quality of reporting which lacked in accuracy about the facts and events of the war.It is obvious that this kind of misinformation seriously destroyed both the image and the morale of the American soldier in Vietnam. There’s no wonder public opinion of the war was very low in America. But the truth is that the media only sunk a slowly sinking politically based ship, as public opinion of the war was already falling. The public were already starting to see through the government’s political talk that they had no definite military plan for victory or a justifiable reason to fight against a nation of infantrymen.The American media just dramatised the events to entirely destroy the very political principles which started the war. The media caused such a moral alarm in America at the time, people lost trust in its own government. The media left t America in such a chaos that its own government had to surrender to public opinion. So to what extend are the media guilty for the loss of the war? The media played a key role in American withdrawal from Vietnam. It might as well be proper to suggest that with American support for the war, America forces effort into the war may have been better and the outcome of the war may have been different.Nevertheless, the chief reality is that the America forces in Vietnam had no apparent military strategy to be s uccessful in its political mean. So consequently the media can not be solely guilty for the American withdrawal. Yet, the question is, would have American forces been withdraw from Vietnam with no media negative reporting of the war? The answer is that we will never know for sure. But we can undoubtedly say that Americans’ support for the war would have mostly remained high all over the war, the pressure on the American troops and government wouldn’t have appeared.Without all of the these factors the American troops may have had the time to adjust to the style of warfare and topography and resolve the behavioural and discipline troubles they were facing which highly attracted the media attention. This could mean that America would have continued the war in Vietnam, which may, but not definitely would have created a different outcome. Despite this, you still can’t say that the media is totally responsible for the withdrawal of American fighting forces in Vietnam. It was the longest war in American history which resulted in nearly 60,000 American deaths and an estimated 2 million Vietnamese deaths.The financial cost to the United States was just as deep. Even today, many Americans still ask whether the American effort in Vietnam was a sin, a blunder, a necessary war, or a noble cause, or an idealistic, if failed, effort to protect the South Vietnamese from totalitarian government. Nicholas Hopkinson’s statement is the one that probably best reflects the situation of the media in Vietnam: As public enthusiasm faded, reporting became more and more critical[†¦] but to single the media out as the decisive element in declining public opinion is incorrect.US opinion turned against the war because it was long unsuccessful, costly in terms of human life and expenditure. ’[6] Words: 2314 References Bibliography: 1. Braestrup, Peter. â€Å"The News Media and the War in Vietnam: Myths and Realities† 2. Don Oberdorfer, Tet! , S eptember 1, 1971 3. Elegant, Robert, ‘How to Lose a War', Encounter, 57, 2 (1981), 73 89 4. Hallin, Daniel C. , The Uncensored War: The Media and Vietnam. Los Angles: California University of California Press, 1986. 5. George Herring, America's Longest War: The United States in Vietnam, 1950-1975 (1986) . Nicholas Hopkinson, â€Å"War and the media’’ Wilton Paper 55 (London: HMSO, 1992): 6-7 7. Westmoreland, William C. A Soldier Reports (Garden City, N. Y. , Doubleday, 1976) 8. William M. Hammond, Public Affairs: The Military and the Media, 1962-1968 (1989) and Public Affairs: The Military and the Media, 1968-1973 (1996). 9. Wyatt, Clarence R. Paper Soldiers: The American Press and the Vietnam War. Chicago: University of Chicago Press, 1995. Internet sources : 10. www. nytimes. com/learning/general/onthisday/big/1115. html

Technology And Farming During The World - 809 Words

Technology and Farming Introduction Many advances in farming have helped the world grow and prosper, for example, technology has changed farming drastically by enabling farm equipment to be motorized, allowing farmers to be able to farm more land and more crops, and by allowing scientists to experiment and make hybrid crops. Advances in science has enabled a massive growth in animal care and how animals are raised. Motorized Equipment To begin with, the equipment used for farming has dramatically changed from horses pulling plows to tractors being computerized and automatically created to do the all the work. â€Å"Agricultural technology is among of the most revolutionary and impactful areas of modern technology† (Agricultural†¦show more content†¦Around 1700, Jethro Tull invented a horse-drawn seed drill, this allowed farmers to stop hand sowing (How Modern Farming Has Changed the World, 2016). â€Å"Farmers cut crops with scythes and manually removed the seeds before bundling the stalks†(Dove, 2016, p.1). â€Å"Through the use of technology, each farmer is able to feed 155 people today, compared to 1940, when one farmer could feed only 19 people†(Comparing Agriculture of the Past with Today, 2016, p.1). Automatic milkers and computerized feeders allow dairy farmers to take care of up to 200 cows (How Modern Farming Has Changed the World). Even the simplest of inventions made the biggest impact, barbed wired made it easy for farmers to keep their cattle in their land (The Science and Technology of Agriculture, 2016), barbed wire allowed cows to transition from grazing to cattle raising (The Science and Technology of Agriculture, 2016). Advances in technology made the industrial revolution possible by farmers being able to provide cheap food for towns (How Modern Farming Has Changed the World, 2016). Advances in Science and Animal Care â€Å"Commercial fertilizer, a blend of nitrogen, phosphate, and potash, allows farmers to realize high yields on their crops and to use the same plot of land year upon year for their crops† (Dove, 2016, p.1). â€Å"Between 1890 and 1899, American farmers