Analysis on the Studio System of Hollywood in the Golden Era Essay Example for Free

Analysis on the Studio System of Hollywood in the Golden Era Essay The Fall of Monopoly ‘As far as the filmmaking process is concerned, stars are essentially worthless and absolutely essential. ’ -William Goldman It started with Florence Lawrence as the ‘Biograph Girl’ in the early 1900’s, and bred into the formation of the Universal Studios by one smart producer by the name of Carl Laemmle. The birth of Hollywood had never experienced a joyful transition for editors and actors, who back in the day were treated like hired help by directors. The silent film era was not the commercial enterprise it is today; it was a mere impression of Vaudeville, and studios generated cheap and generic content, while actors remained anonymous and low paid. Florence was one of the popular actresses of the time who helped create a celebrity culture that was infact a farce used by Studios to promote their cinematographic content. And this farce became known in history as the Golden Age of Hollywood. The celebrity culture that is idolized today was in actuality a ploy used to attract an audience following. Stars were created, not born. The Studio System comprised of The Big Five (MGM, Paramount, Warner Brothers, RKO and Fox), who are credited for creating some of the most legendary stars of the time, thus leading to the term ‘star system’. Studios invested a great deal of time and money into grooming and publicizing an actor, and owning him in the process, simply by signing him to a contract. When an actor had inscribed his name on the formidable piece of paper, he had no future of his own. Depending on his talent and the response his image got from the audience, he was either crucial or dispensable to the Studio he had been employed by. The industry was relentless when it came to the treatment of actors. Fame, in all its shallow glory, was a high price to pay for the compensation of no personal life and no personal choice. Actors were required to play the roles they were assigned to without question or argument, made to indulge in publicity stints, and traded off or loaned to another Studio on mutually agreed upon arrangements without their consent. Performers were very similar to the posters their faces were displayed on because they had absolutely no control over their careers, just as a poster has no control over how it is used or interpreted. An example of the extent to which a Studio went to glamourize its artists is Rita Hayworth, who was coerced into changing her name from Margarita Casino and made to get plastic surgery performed (hairline electrolysis) to make her more marketable. However, that is not to say that actors were treated with any respect when the silent era fell off its crippling platform. The past was not a happy place for an actor before the term ‘celebrity’ came into being. The release of ‘The Jazz Singer’ is known to be the pedestal on which the studio era was founded upon because it was the first motion picture with a few minutes of synchronized sound. When sound entered the frame, Vaudeville rapidly depleted into obscurity, and former Vaudeville actors were faced with the bitter reality of unemployment, forcing them to migrate into the film industry. This immigration created a domino effect for the entertainers already present in the enterprise. They had never been exposed to the element of voice being incorporated into a motion picture, and could not adjust to the inclusion of sound. Various hurdles included bad voices, thick accents and the inability to remember dialogues. Moreover, the Big Five circulated their own theatre chains, and adopted specific genre as labels for their reputation and glory. In this process, actors were never given much flexibility to explore or expand their potential, but were in a constant state of repeating the same theme over and over again in each new production. On a more positive note, this repetition led to the recognition of some very creative artists, who explored a theme with such unabashed inquisition that no two films were ever shown in a tiresome cycle of alliteration. ‘One well-known actor in this situation was Gene Kelly. Gene Kelly was associated with musical films such as  An American in Paris,  Les Girls,  Brigadoon, and  Singin’ in the Rain. In virtually all of his movies, Kelly would sing and go through intricate dance numbers. MGM, the studio Kelly was contracted with, knew people expected this from Kelly, so the studio made sure to put Kelly in musical films. The few movies Kelly was in that weren’t musicals did not do nearly as well as the ones he sang and danced in. When people saw a trailer for a movie with Gene Kelly in it, they expected to see a musical; this expectation kept people coming back to see more of Kelly’s movies, which brought MGM more and more revenue. ’ The Studio System did not only control the lives of its performers within the confines of its sets or production houses. An employee had no concept of privacy or freedom of indulging in the luxuries offered outside the bubble of the world of film. Due to the incredulous amount of acclamation an actor received, he could not ruin his public image, even by making the mistakes a common citizen could afford to overlook. Studios had contracts drawn with ‘morality clauses’ that forbade an employee from engaging in the utility of drug abuse, divorce and adultery as these would lead to the consequence of a foiled public image, thus resulting in loss of annuity. However, even though such social control was oppressive, it retained a modest reputation and acted as a form of deterrence for the artists. However, the violation of these clauses led to no direct effect on the perpetrators, because the Studio they were assigned to would pay off the witnesses or offer exclusive stories to tabloids in exchange for not reporting on the truth of the matter. In this sense, actors were provided with free reign to do as they pleased. ‘Cinema is the culmination of the obsessive, mechanistic male drive in western culture. The movie projector is an Apollonian straight-shooter, demonstrating the link between aggression and art. Every pictorial framing is a ritual limitation, a barred precinct. -Camille Paglia Was it the male drive in western culture -if the term western culture can be deemed as appropriate- that led to the birth of explicit content in Hollywood, or the market demand for it? Censorship created a massive propaganda in the late 1920’s. It was one of the major reasons why The Motion Picture Commission was established in 1921, the strongest form of government that induced censorship on films for the next 44 years. It began with ‘The Kiss’ in 1896, in which a man and a woman shared a kiss that barely lasted half a minute, leading on to ‘Know Thy Husband’ (1919), in hich the protagonist contracted a horrible disease after indulging in his primal desires in the city, evolving further into ‘Outside the Law’ (1921), a crime film with the same connotations. Hollywood was never subtle with its aesthetic imagination, and actors, as a result, developed a notorious reputation. Infact, Hollywood itself was renowned to be a place infested with scandal and immoral behavior. This splintered imagery of the sensational mirror that reflected the flaws of Hollywood was not for the righteous offence of the general public alone. Celebrities suffered directly from the environment they presided in- literally in the fatal sense. For instance, one of the most tragic deaths a star faced was Thelma Todd, a young actress who had costarred in a number of classic comedies with the Marx Brothers, Laurel and Hardy, and Buster Keaton (Monkey Business’ ‘Horse Feathers’). She died at the age of 30, in 1935, believed to have committed an accidental suicide when she was found dead in her car, although the general opinion suggested suspicions of cold blooded murder. Film as dream, film as music. No art passes our conscience in the way film does, and goes directly to our feelings, deep down into the dark rooms of our souls. -Ingmar Bergman The Studio System gave rise to legendary personalities, faces of people that are remembered as icons of inspiration and unadulterated talent. It gave rise to films like ‘Casablanca’, ‘Gone with the Wind’, ’The Maltese Falcon’ and ‘Singin’ in the Rain’. It gave us Marilyn Monroe, Fred Astaire, and countless other idols to look up to and admire. However, with the emergence of Sound and Studio, even when Hollywood acquired so much recognition and wealth, it lost the sense of morality and the image of an honest corporation by degrading its own reputation, and that of its main components, the actors. Cinema is now associated with superficial glamour, it is a world that is infested with deceit and facade. A false pretense of joy through fame, a bubble of happiness that does not seem to exist in the first place. Ironically, the fall of the Studio System began with the reason for its accession. War brought people to theatres, and war became its undoing. After World War II legal, technological and social developments converged on the Hollywood film industry, undermining the economic foundation of the studio system. The antitrust suit against Paramount in 1948, combined with the increasing strength of unions, encouraged the growing practice of freelancing’. This decision not only outlawed the practice of block booking, it also forced the studios to sell their theater chains, and reduce the number of productions. What was once a monopoly of the ‘Big Five’ turned out to be a doorway for minor studios and independent filmmakers to thrive in. As far as the actors were concerned, they found the opportunity to become more genre savvy, and demand the right to refuse a contract, or opt to go to a free agency instead. They found the leeway to become more selective and demanding in their preferences regarding their professional services. The star system crumbled, but the stars found liberation. References: http://www.hollywoodmoviememories.com/articles/hollywood-history/hollywood-studio-system-golden.php http://www.moderntimes.com/palace/apex/ http://www.filmsite.org/30sintro2.html http://tvtropes.org/pmwiki/pmwiki.php/UsefulNotes/TheGoldenAgeOfHollywood?from=Main.GoldenAgeOfHollywood http://www.ritahayworth.com/ http://ivythesis.typepad.com/term_paper_topics/2009/09/the-rise-and-fall-of-hollywood-studio-system.html http://tvtropes.org/pmwiki/pmwiki.php/UsefulNotes/FallOfTheStudioSystem?from=Main.FallOfTheStudioSystem

Indo-pak relations

Indo-pak relations CHAPTER VII INDO-PAK RELATIONS Background 1.Indo-Pakistan relations are grounded in the political, geographic, cultural, and economic links between the Republic of India and the Islamic Republic of Pakistan. The two countries share much of their common geographic location, and religious demographics yet diplomatic relations between the two are prefaced by numerous military conflicts and territorial disputes. However, attempts to improve relations have been made. 2.Since independence, Pakistan owes much of its identity to its distinctness from India. It has engaged in three sizable wars with India, plus several major border skirmishes. The struggle over Kashmir has contributed to most of these conflicts. Pakistan has sponsored decades of proxy paramilitary operations undertaken in the name of freedom fighting designed to right or take revenge for cumulative wrongs. It has developed amd deployed nuclear weapons whose sole strategic purpose relates to India. And it has used its relations with other countries, particularly Afghanistan and China to promote its anti India interests. Recently also its perceived participation in the US led war on terror has been cunningly exploited to continue the proxy war against India with perpetual immunity from worldwide criticism.  Ã‚  Ã‚  Ã‚   3.Most of South Asia came under direct control of Great Britain in the late 18th century. The British rule over the Indian subcontinent lasted for almost 150 years. 95% of the people living in South Asia practiced either Hinduism or Islam. The Muslim League, headed by Jinnah, proposed the Two Nation Theory in the early 20th century. According to the theory, Muslims and others shared little in common, and British India should be divided into two separate countries, one for the Muslims and the other for the Hindu majority, which he feared would suppress the Muslim minority. The campaign gained momentum in early 1940s and by the end of World War II, British Indias partition was inevitable. The Partition of India in 1947 created two large countries independent from Britain: Pakistan as two wings in the East and West separated by India in the middle. After Independence, India and Pakistan had established diplomatic relations. Subsequent years were marked by bitter periodic conflict, and t he nations went to war four times. The war in 1971 ended in defeat and another partition of Pakistan. The eastern wing split off as a new country named Bangladesh, while the western wing continued as Pakistan. Stumbling Blocks 4.The Debris of partition of India in 1947 has clouded Indias relations with Pakistan. Pakistans tendency to assume the role of guardianship of Indian Muslims is one of the major irritants between India and Pakistan. Another matter which became source of irritant between two countries was the distribution of river waters. The divergent perception of both the countries on Indian Ocean as a zone of peace was yet another irritant including the sir creek issue. Pakistan threat perception, inspite of assurances by India, coupled with party syndrome gave shape to a proposal for Nuclear Weapon free zone in South-Asia (N.W.F.Z.S.A.); for it is believed that internal security will give the external powers an opportunity and justification to futher enhance their presence and prestige in the Indian Ocean region. So this perception of Pakistan and India on the Indian Ocean as a zone of peace led to differences in their strategic perception. 5.Another major issue which emerged between the two countries was the question of political status of the three princely states Junagarh, Hyderabad and Kashmir. But the most important issue which has marred the relations between the two countries has indeed been Kashmir. The dispute over Siachin glacier is an offshoot of the same problem. 6.Alleged interference in each others internal affairs is an irritant in Indo-Pak relations which has raised its head very seriously in the recent years. India considers Pakistan responsible for fomenting terrorism in Punjab and Kashmir. 7.Pakistan has always viewed Afghanistan through the prism of antagonistic relationship with India, attempting to use Afghanistan as its defence in depth and cultivating its Mujahedeen as paramilitary reservists against possible Indian threats. Subsequent to the fall of Taliban in Afghanistan, Indian humanitarian aid and development activity in the war ravaged country appeared to Pakistan as a threat to its support in Afghanistan and that inimical interests will have free reign in the country. Pakistan has viewed this activity with dismay, its fear of encirclement compounded by Indias establishment of a new airbase at Farkhor in Tajikistan. Current Challenges 8.A year after the Mumbai attack, two questions have persisted: was the ISI or any other state element of Pakistan an accomplice in the attacks? If ISI which had nurtured LeT to wage a proxy war against India, has cut itself from the group as claimed and was not involved in the attack, what stops Pakistan from effectively cracking on it? 9.In weeks after the attacks, the Pakistan government, under immense international pressure and scrutiny, took several steps. A raid on Lashkar camp at Muzaffarabad led to the arrest of Commander Zuikur Rehman Lakhvi. This is possibly also where Abdul Wajid, whose alias has been shown as Zarar Shah, was picked up. Both are alleged master minds of the attack. Next it placed Hafiz Saeed, LeT founder and leader of its front organization, Jammat ud Dawa (JuD), under house arrest. 10.Some other corners of establishment may still hold the view that the LeT can be viewed as a strategic asset. The Pakistani governments reluctance to go all the way against LeT is too obvious. After six months of house arrest, Hafiz Saeed is a free man, and the government says it cannot act against him unless New Delhi provides concrete evidence linking him to Mumbai attacks. All other JuD activists have been released. The organization has not yet been banned and now operates under the name of Fallah-i- Insaniyat and was noticed in relief operations among the internally displaced in the Swat valley during the military operations there. 11.As the arrest of David Headley and Tahawwur Hussain Rana in the US has shown, the LeT also retains operational capabilities. The two men are said to have been in communication with the LeT, and though they were arrested for an alleged terror plot against the Danish newspaper, they were also said to be planning attacks on National Defence College at New Delhi. Latest probes in Mumbai have revealed their definite links with the Mumbai terror attacks and many such incidents across India in the past. Further arrest of a Pakistan army Major for his links with Headley and Rana are bound to raise questions on LeTs continuing links with the military as an institution, but with the sections within it, especially because the Major retired only two years ago. 12.Home Minister Chidamarams words point us in the direction of just why these issues need to be taken seriously: another major terrorist attack on India could have consequences that would destabilise both the countries and could conceivably precipitate a regional crisis. In both Islamabad and New Delhi Mr. Chidambarams speech was interpreted as warning that India would respond to future mass casualty attack by targeting jihadist bases and logistical facilities in Pakistan. That, in turn could snowball into a conflict that would bring misery to all the people of South Asia. 13.It is now accepted within the Pakistan Military that Al Qaeda, Taliban and their allies among Punjabi jihadis operate as a syndicate. But while they have included the Jaish-e-Mohammed, along with Lashkar-e-Jhangvi and the Sipah-e-Sahaba, in the syndicate, the LeT is still not considered part of it. 14.The threat to Indias security from Islamic fundamentalism and globalization of terror is immense. It is feared in some quarters that Pakistan is sending fundamentalist groups to Bangladesh as well. The Dhaka based extremist Islamic group, Harkatul-Jehad- Al-Islam (HJAI), is believed to be financed by Osama Bin Laden. The evidence suggests that ISI and Taliban are involved with Harkatul operations in Bangladesh. 15.On the other hand Pakistans Foreign Minister Shah Mehmood Qureshi  Ã‚   says Pakistan is compiling hard evidence of Indias involvement in terrorist attacks on Pakistans public and its armed forces 16.The Indian External affairs minister Mr SM Krishna assured of the fact that India has clean hands with respect to Baluchistan and Afghanistan. He also mentioned that Islamabads suspicion s of Indias ulterior motives in Afghanistan were unfounded. The only motive is to restore peace and stability in the war-torn country 17.During the period of excessive tension, India and Pakistan have growled at each other while meaningfully pointing towards their respective nuclear arsenal. Most recently following the Mumbai massacre, Pakistani troops were moved out of NWFP towards the eastern border. Baitullah Mehsuds offer to jointly fight India was welcomed by the Pakistani army. 18.India should derive no satisfaction from Pakistans predicament. Although religious extremists see ordinary Muslims as Munafiqs (hypocrites) and therefore free to be blown up in markets and mosques they hate Hindus even more. In their calculus, hurting India would buy even more tickets for heaven than hurting Pakistan. They dream about ripping apart both societies or starting a war preferably nuclear between Pakistan and India. 19.A common threat needs a common defence. But this is difficult unless Pakistan India conflict is reduced in intensity. In fact the extremist groups that threaten both countries today are an unintended consequence of Pakistans frustration at Indias obduracy in Kashmir.

Amplitude modulation

Amplitude modulation Amplitude modulation Amplitude modulation (AM) is a technique used in electronic communication, most commonly for transmitting information via a radio carrier wave. AM works by varying the strength of the transmitted signal in relation to the information being sent. For example, changes in the signal strength can be used to reflect the sounds to be reproduced by a speaker, or to specify the light intensity of television pixels. (Contrast this with frequency modulation, also commonly used for sound transmissions, in which the frequency is varied; and phase modulation, often used in remote controls, in which the phase is varied) In the mid-1870s, a form of amplitude modulation—initially called undulatory currents—was the first method to successfully produce quality audio over telephone lines. Beginning with Reginald Fessendens audio demonstrations in 1906, it was also the original method used for audio radio transmissions, and remains in use today by many forms of communication—AM is often used to refer to the mediumwave broadcast band (see AM radio). Forms of amplitude modulation As originally developed for the electric telephone, amplitude modulation was used to add audio information to the low-powered direct current flowing from a telephone transmitter to a receiver. As a simplified explanation, at the transmitting end, a telephone microphone was used to vary the strength of the transmitted current, according to the frequency and loudness of the sounds received. Then, at the receiving end of the telephone line, the transmitted electrical current affected an electromagnet, which strengthened and weakened in response to the strength of the current. In turn, the electromagnet produced vibrations in the receiver diaphragm, thus closely reproducing the frequency and loudness of the sounds originally heard at the transmitter. In contrast to the telephone, in radio communication what is modulated is a continuous wave radio signal (carrier wave) produced by a radio transmitter. In its basic form, amplitude modulation produces a signal with power concentrated at the carrier frequency and in two adjacent sidebands. This process is known as heterodyning. Each sideband is equal in bandwidth to that of the modulating signal and is a mirror image of the other. Amplitude modulation that results in two sidebands and a carrier is often called double sideband amplitude modulation (DSB-AM). Amplitude modulation is inefficient in terms of power usage and much of it is wasted. At least two-thirds of the power is concentrated in the carrier signal, which carries no useful information (beyond the fact that a signal is present); the remaining power is split between two identical sidebands, though only one of these is needed since they contain identical information. To increase transmitter efficiency, the carrier can be removed (suppressed) from the AM signal. This produces a reduced-carrier transmission or double-sideband suppressed-carrier (DSBSC) signal. A suppressed-carrier amplitude modulation scheme is three times more power-efficient than traditional DSB-AM. If the carrier is only partially suppressed, a double-sideband reduced-carrier (DSBRC) signal results. DSBSC and DSBRC signals need their carrier to be regenerated (by a beat frequency oscillator, for instance) to be demodulated using conventional techniques. Even greater efficiency is achieved—at the expense of increased transmitter and receiver complexity—by completely suppressing both the carrier and one of the sidebands. This is single-sideband modulation, widely used in amateur radio due to its efficient use of both power and bandwidth. A simple form of AM often used for digital communications is on-off keying, a type of amplitude-shift keying by which binary data is represented as the presence or absence of a carrier wave. This is commonly used at radio frequencies to transmit Morse code, referred to as continuous wave (CW) operation. In 1982, the International Telecommunication Union (ITU) designated the various types of amplitude modulation as follows: Designation Description A3E double-sideband full-carrier the basic AM modulation scheme R3E single-sideband reduced-carrier H3E single-sideband full-carrier J3E single-sideband suppressed-carrier B8E independent-sideband emission C3F vestigial-sideband Lincompex linked compressor and expander Example: double-sideband AM A carrier wave is modeled as a simple sine wave, such as: c(t) = Ccdot sin(omega_c t + phi_c),, where the radio frequency (in Hz) is given by: omega_c / (2pi)., For generality, C,and phi_c,are arbitrary constants that represent the carrier amplitude and initial phase. For simplicity, we set their respective values to 1 and 0. Let m(t) represent an arbitrary waveform that is the message to be transmitted. And let the constant M represent its largest magnitude. For instance: m(t) = Mcdot cos(omega_m t + phi)., Thus, the message might be just a simple audio tone of frequency omega_m / (2pi)., It is generally assumed that omega_m ll omega_c, and that min[ m(t) ] = -M., Then amplitude modulation is created by forming the product: y(t), = [A + m(t)]cdot c(t),, = [A + Mcdot cos(omega_m t + phi)]cdot sin(omega_c t). A,represents another constant we may choose. The values A=1, and M=0.5, produce a y(t) depicted by the graph labelled 50% Modulation in 4. For this simple example, y(t) can be trigonometrically manipulated into the following equivalent form: y(t) = Acdot sin(omega_c t) + begin{matrix}frac{M}{2} end{matrix} left[sin((omega_c + omega_m) t + phi) + sin((omega_c omega_m) t phi)right]., Therefore, the modulated signal has three components, a carrier wave and two sinusoidal waves (known as sidebands) whose frequencies are slightly above and below omega_c., Also notice that the choice A=0 eliminates the carrier component, but leaves the sidebands. That is the DSBSC transmission mode. To generate double-sideband full carrier (A3E), we must choose: A ge M., For more general forms of m(t), trigonometry is not sufficient. But if the top trace of 2 depicts the frequency spectrum, of m(t), then the bottom trace depicts the modulated carrier. It has two groups of components: one at positive frequencies (centered on + ωc) and one at negative frequencies (centered on − ωc). Each group contains the two sidebands and a narrow component in between that represents the energy at the carrier frequency. We need only be concerned with the positive frequencies. The negative ones are a mathematical artifact that contains no additional information. Therefore, we see that an AM signals spectrum consists basically of its original (2-sided) spectrum shifted up to the carrier frequency. For those interested in the mathematics of 2, it is a result of computing the Fourier transform of: [A + m(t)]cdot sin(omega_c t),,using the following transform pairs: begin{align} m(t) quad stackrel{mathcal{F}}{Longleftrightarrow}quad M(omega) \ sin(omega_c t) quad stackrel{mathcal{F}}{Longleftrightarrow}quad i pi cdot [delta(omega +omega_c)-delta(omega-omega_c)] \ Acdot sin(omega_c t) quad stackrel{mathcal{F}}{Longleftrightarrow}quad i pi A cdot [delta(omega +omega_c)-delta(omega-omega_c)] \ m(t)cdot sin(omega_c t) quad stackrel{mathcal{F}}{Longleftrightarrow} frac{1}{2pi}cdot {M(omega)} * {i pi cdot [delta(omega +omega_c)-delta(omega-omega_c)]} \ = frac{i}{2}cdot [M(omega +omega_c) M(omega -omega_c)] end{align} In terms of the positive frequencies, the transmission bandwidth of AM is twice the signals original (baseband) bandwidth—since both the positive and negative sidebands are shifted up to the carrier frequency. Thus, double-sideband AM (DSB-AM) is spectrally inefficient, meaning that fewer radio stations can be accommodated in a given broadcast band. The various suppression methods in Forms of AM can be readily understood in terms of the diagram in 2. With the carrier suppressed there would be no energy at the center of a group. And with a sideband suppressed, the group would have the same bandwidth as the positive frequencies of M(omega)., The transmitter power efficiency of DSB-AM is relatively poor (about 33%). The benefit of this system is that receivers are cheaper to produce. The forms of AM with suppressed carriers are found to be 100% power efficient, since no power is wasted on the carrier signal which conveys no information. Modulation index As with other modulation indices, in AM, this quantity, also called modulation depth, indicates by how much the modulated variable varies around its original level. For AM, it relates to the variations in the carrier amplitude and is defined as: h = frac{mathrm{peak value of } m(t)}{A} = frac{M}{A}, where M,and A,were introduced above. So if h = 0.5, the carrier amplitude varies by 50% above and below its unmodulated level, and for h = 1.0 it varies by 100%. To avoid distortion in the A3E transmission mode, modulation depth greater than 100% must be avoided. Practical transmitter systems will usually incorporate some kind of limiter circuit, such as a VOGAD, to ensure this. Variations of modulated signal with percentage modulation are shown below. In each image, the maximum amplitude is higher than in the previous image. Note that the scale changes from one image to the next. Amplitude modulator designs This section does not cite any references or sources. Please help improve this article by adding citations to reliable sources. Unsourced material may be challenged and removed. (October 2008) This article only describes one highly specialized aspect of its associated subject. Please help improve this article by adding more general information. (October 2009) Circuits A wide range of different circuits have been used for AM, but one of the simplest circuits uses anode or collector modulation applied via a transformer. While it is perfectly possible to create good designs using solid-state electronics, valved (vacuum tube) circuits are shown here. In general, valves are able to more easily yield RF powers, in excess of what can be easily achieved using solid-state transistors. Most high-power broadcast stations still use valves. Anode modulation using a transformer. The tetrode is supplied with an anode supply (and screen grid supply) which is modulated via the transformer. The resistor R1 sets the grid bias; both the input and outputs are tuned LC circuits which are tapped into by inductive coupling Modulation circuit designs can be broadly divided into low and high level. Low level Here a small audio stage is used to modulate a low power stage; the output of this stage is then amplified using a linear RF amplifier. Advantages The advantage of using a linear RF amplifier is that the smaller early stages can be modulated, which only requires a small audio amplifier to drive the modulator. Disadvantages The great disadvantage of this system is that the amplifier chain is less efficient, because it has to be linear to preserve the modulation. Hence Class C amplifiers cannot be employed. An approach which marries the advantages of low-level modulation with the efficiency of a Class C power amplifier chain is to arrange a feedback system to compensate for the substantial distortion of the AM envelope. A simple detector at the transmitter output (which can be little more than a loosely coupled diode) recovers the audio signal, and this is used as negative feedback to the audio modulator stage. The overall chain then acts as a linear amplifier as far as the actual modulation is concerned, though the RF amplifier itself still retains the Class C efficiency. This approach is widely used in practical medium power transmitters, such as AM radiotelephones. High level With high level modulation, the modulation takes place at the final amplifier stage where the carrier signal is at its maximum Advantages One advantage of using class C amplifiers in a broadcast AM transmitter is that only the final stage needs to be modulated, and that all the earlier stages can be driven at a constant level. These class C stages will be able to generate the drive for the final stage for a smaller DC power input. However, in many designs in order to obtain better quality AM the penultimate RF stages will need to be subject to modulation as well as the final stage. Disadvantages A large audio amplifier will be needed for the modulation stage, at least equal to the power of the transmitter output itself. Traditionally the modulation is applied using an audio transformer, and this can be bulky. Direct coupling from the audio amplifier is also possible (known as a cascode arrangement), though this usually requires quite a high DC supply voltage (say 30 V or more), which is not suitable for mobile units. See also * AM radio * Mediumwave band used for AM broadcast radio * Longwave band used for AM broadcast radio * Frequency modulation * Shortwave radio almost universally uses AM, narrow FM occurring above 25MHz. * Modulation, for a list of other modulation techniques * Amplitude modulation signalling system (AMSS), a digital system for adding low bitrate information to an AM signal. * Sideband, for some explanation of what this is. * Types of radio emissions, for the emission types designated by the ITU * Airband * Quadrature amplitude modulation References * Newkirk, David and Karlquist, Rick (2004). Mixers, modulators and demodulators. In D. G. Reed (ed.), The ARRL Handbook for Radio Communications (81st ed.), pp.15.1-15.36. Newington: ARRL. ISBN 0-87259-196-4. Pulse-amplitude modulation From Wikipedia, the free encyclopedia Principle of PAM; (1) original Signal, (2) PAM-Signal, (a) Amplitude of Signal, (b) Time Overview Pulse-amplitude modulation, acronym PAM, is a form of signal modulation where the message information is encoded in the amplitude of a series of signal pulses. Example: A two bit modulator (PAM-4) will take two bits at a time and will map the signal amplitude to one of four possible levels, for example −3 volts, −1 volt, 1 volt, and 3 volts. Demodulation is performed by detecting the amplitude level of the carrier at every symbol period. Pulse-amplitude modulation is widely used in baseband transmission of digital data, with non-baseband applications having been largely superseded by pulse-code modulation, and, more recently, by pulse-position modulation. In particular, all telephone modems faster than 300 bit/s use quadrature amplitude modulation (QAM). (QAM uses a two-dimensional constellation). Usage of Pulse-amplitude modulation in Ethernet It should be noted, however, that some versions of the widely popular Ethernet communication standard are a good example of PAM usage. In particular, the Fast Ethernet 100BASE-T2 medium, running at 100Mb/s, utilizes 5 level PAM modulation (PAM-5) running at 25 megapulses/sec over two wire pairs. A special technique is used to reduce inter-symbol interference between the unshielded pairs. Later, the gigabit Ethernet 1000BASE-T medium raised the bar to use 4 pairs of wire running each at 125 megapulses/sec to achieve 1000Mb/s data rates, still utilizing PAM-5 for each pair. The IEEE 802.3an standard defines the wire-level modulation for 10GBASE-T as a Tomlinson-Harashima Precoded (THP) version of pulse-amplitude modulation with 16 discrete levels (PAM-16), encoded in a two-dimensional checkerboard pattern known as DSQ128. Several proposals were considered for wire-level modulation, including PAM with 12 discrete levels (PAM-12), 10 levels (PAM-10), or 8 levels (PAM-8), both with and without Tomlinson-Harashima Precoding (THP). amplitude modulation DEFINITION- Also see modulation. Amplitude modulation (AM) is a method of impressing data onto an alternating-current (AC) carrier waveform.The highest frequency of the modulating data is normally less than 10 percent of the carrier frequency.The instantanous amplitude (overall signal power) varies depending on the instantaneous amplitude of the modulating data. In AM, the carrier itself does not fluctuate in amplitude.Instead, the modulating data appears in the form of signal components at frequencies slightly higher and lower than that of the carrier.These components are called sidebands. The lower sideband (LSB) appears at frequencies below the carrier frequency; the upper sideband (USB) appears at frequencies above the carrier frequency.The LSB and USB are essentially mirror images of each other in a graph of signal amplitude versus frequency, as shown in the illustration.The sideband power accounts for the variations in the overall amplitude of the signal. When a carrier is amplitude-modulated with a pure sine wave, up to 1/3 (33 percent) of the overall signal power is contained in the sidebands.The other 2/3 of the signal power is contained in the carrier, which does not contribute to the transfer of data.With a complex modulating signal such as voice, video, or music, the sidebands generally contain 20 to 25 percent of the overall signal power; thus the carrier consumes 75 to 80 percent of the power.This makes AM an inefficient mode.If an attempt is made to increase the modulating data input amplitude beyond these limits, the signal will become distorted, and will occupy a much greater bandwidth than it should.This is called overmodulation, and can result in interference to signals on nearby frequencies. Analog modulation methods A low-frequency message signal (top) may be carried by an AM or FM radio wave. Common analog modulation techniques are: * Amplitude modulation (AM) (here the amplitude of the carrier signal is varied in accordance to the instantaneous amplitude of the modulating signal) o Double-sideband modulation (DSB) Â § Double-sideband modulation with unsuppressed carrier (DSB-WC) (used on the AM radio broadcasting band) Â § Double-sideband suppressed-carrier transmission (DSB-SC) Â § Double-sideband reduced carrier transmission (DSB-RC) o Single-sideband modulation (SSB, or SSB-AM), Â § SSB with carrier (SSB-WC) Â § SSB suppressed carrier modulation (SSB-SC) o Vestigial sideband modulation (VSB, or VSB-AM) o Quadrature amplitude modulation (QAM) * Angle modulation o Frequency modulation (FM) (here the frequency of the carrier signal is varied in accordance to the instantaneous frequency of the modulating signal) o Phase modulation (PM) (here the phase shift of the carrier signal is varied in accordance to the instantaneous phase shift of the modulating signal) AMPLITUDE MODULATION How it works. We know that something as simple as a crystal diode (rectifier) can be used to capture sound from the air and put it into a pair of earphones or an amplifier and speaker. How can this work? We will cover that here and now. All AM (Amplitude Modulation) detectors work basically the same way. What is AM? What we can hear as audio is classically considered to be the frequency range between 20 and 20,000 cycles per second (here after referred to as cycles and abandoning hertz) which I have never liked). In reality most adults can only hear up to about 13,000 cycles. Most speakers cant reproduce anything lower than 30 cycles in spite of the exaggerated claims of proud owners. So lets be generous and call audio 30 to 15,000 cycles. Radio frequencies are between 8,000 cycles and 50,000 megacycles. Thats right there is a range of frequencies that depending on how they are treated can be audio or radio. The AM radio band begins at 540 kilocycles. For simplicity lets say that we want to transmit a 10,000 cycle tone on a radio transmitter operating on 250 kilocycles. The 250 kc transmitting frequency is called the carrier wave because it may be thought of as carrying the audio. The 10,000 cycle audio frequency is called the modulating frequency. We may get into side-bands later. In the above the upper wave is the modulating wave and three cycles of it can be seen. The lower wave is the modulated carrier wave and 75 cycles are visible. (You can count them for yourself or take my word for it.) Notice as the modulating wave goes up the total amplitude of the carrier wave (measured from negative peak to positive peak) goes up. As the modulating wave goes down the amplitude of the carrier wave goes down. When the modulating wave is at zero (the point where it begins and ends) the carrier wave is at its middle or unmodulated value. Think of the modulating wave as controlling a valve that the carrier wave is passing through. (I have direct conformation from England, thats why the British call tubes valves.) The carrier wave can then be sent to an antenna which radiates it out for all the world to hear. Detecting the signal Detection is the word applied to the process of recovering the audio frequencies from the radio frequency carrier. In the case of amplitude modulation it is very simple. All we need to do is to rectify the signal. Rectification is the process used in power supplies to change AC to DC. Its really quite similar for detecting radio signals. Compare the carrier wave in the below with the one in the above. The wave has been run through a rectifier which removed the bottom half of every cycle. If we draw a line connecting the peaks we have the original modulating signal back again. Connecting the peaks is done by using a capacitor to charge up to the peak value and discharge through a resistor just fast enough to follow the modulating frequency but not so fast as to cause a large variation at the carrier frequency. The frequencies chosen for this drawing are fairly close together to make it possible to see the individual cycles on your computer screen. When dealing with the AM broadcast band the carrier frequencies range from 540 kc to 1600 kc. 10,000 cycles is the absolute upper limit for audio on AM and most transmitters only make it to about 8,000 cycles. Look back at the diagram of the crystal set. Use your back button to return here. If you are familiar with power supply circuits you will recognize it as a half wave rectifier with a capacitor to filter out ripple. The resistor makes the capacitor discharge just fast enough but not too fast. A much more rigorous discussion of AM, including side bands, is available by clicking here. This includes not only AM but SSB and FM. AMPLITUDE MODULATION Amplitude modulation or AM as it is often called, is a form of modulation used for radio transmissions for broadcasting and two way radio communication applications. Although one of the earliest used forms of modulation it is still in widespread use today. The first amplitude modulated signal was transmitted in 1901 by a Canadian engineer named Reginald Fessenden. He took a continuous spark transmission and placed a carbon microphone in the antenna lead. The sound waves impacting on the microphone varied its resistance and in turn this varied the intensity of the transmission. Although very crude, signals were audible over a distance of a few hundred metres, although there was a rasping sound caused by the spark. With the introduction of continuous sine wave signals, transmissions improved significantly, and AM soon became the standard for voice transmissions. Nowadays, amplitude modulation, AM is used for audio broadcasting on the long medium and short wave bands, and for two way radio communication at VHF for aircraft. However as there now are more efficient and convenient methods of modulating a signal, its use is declining, although it will still be very many years before it is no longer used. What is amplitude modulation? In order that a radio signal can carry audio or other information for broadcasting or for two way radio communication, it must be modulated or changed in some way. Although there are a number of ways in which a radio signal may be modulated, one of the easiest, and one of the first methods to be used was to change its amplitude in line with variations of the sound. The basic concept surrounding what is amplitude modulation, AM, is quite straightforward. The amplitude of the signal is changed in line with the instantaneous intensity of the sound. In this way the radio frequency signal has a representation of the sound wave superimposed in it. In view of the way the basic signal carries the sound or modulation, the radio frequency signal is often termed the carrier. What is amplitude modulation, AM Amplitude Modulation, AM When a carrier is modulated in any way, further signals are created that carry the actual modulation information. It is found that when a carrier is amplitude modulated, further signals are generated above and below the main carrier. To see how this happens, take the example of a carrier on a frequency of 1 MHz which is modulated by a steady tone of 1 kHz. The process of modulating a carrier is exactly the same as mixing two signals together, and as a result both sum and difference frequencies are produced. Therefore when a tone of 1 kHz is mixed with a carrier of 1 MHz, a sum frequency is produced at 1 MHz + 1 kHz, and a difference frequency is produced at 1 MHz 1 kHz, i.e. 1 kHz above and below the carrier. If the steady state tones are replaced with audio like that encountered with speech of music, these comprise many different frequencies and an audio spectrum with frequencies over a band of frequencies is seen. When modulated onto the carrier, these spectra are seen above and below the carrier. It can be seen that if the top frequency that is modulated onto the carrier is 6 kHz, then the top spectra will extend to 6 kHz above and below the signal. In other words the bandwidth occupied by the AM signal is twice the maximum frequency of the signal that is used to modulated the carrier, i.e. it is twice the bandwidth of the audio signal to be carried. Amplitude demodulation Amplitude modulation, AM, is one of the most straightforward ways of modulating a radio signal or carrier. The process of demodulation, where the audio signal is removed from the radio carrier in the receiver is also quite simple as well. The easiest method of achieving amplitude demodulation is to use a simple diode detector. This consists of just a handful of components:- a diode, resistor and a capacitor. AM diode detector AM Diode Detector In this circuit, the diode rectifies the signal, allowing only half of the alternating waveform through. The capacitor is used to store the charge and provide a smoothed output from the detector, and also to remove any unwanted radio frequency components. The resistor is used to enable the capacitor to discharge. If it were not there and no other load was present, then the charge on the capacitor would not leak away, and the circuit would reach a peak and remain there. Advantages of Amplitude Modulation, AM There are several advantages of amplitude modulation, and some of these reasons have meant that it is still in widespread use today: * It is simple to implement * it can be demodulated using a circuit consisting of very few components * AM receivers are very cheap as no specialised components are needed. Disadvantages of amplitude modulation Amplitude modulation is a very basic form of modulation, and although its simplicity is one of its major advantages, other more sophisticated systems provide a number of advantages. Accordingly it is worth looking at some of the disadvantages of amplitude modulation. * It is not efficient in terms of its power usage * It is not efficient in terms of its use of bandwidth, requiring a bandwidth equal to twice that of the highest audio frequency * It is prone to high levels of noise because most noise is amplitude based and obviously AM detectors are sensitive to it. Summary AM has advantages of simplicity, but it is not the most efficient mode to use, both in terms of the amount of space or spectrum it takes up, and the way in which it uses the power that is transmitted. This is the reason why it is not widely used these days both for broadcasting and for two way radio communication. Even the long, medium and short wave broadcasts will ultimately change because of the fact that amplitude modulation, AM, is subject to much higher levels of noise than are other modes. For the moment, its simplicity, and its wide usage, mean that it will be difficult to change quickly, and it will be in use for many years to come

Genetically Engineered Food Essay -- GMOs Genetically Modified Foods

Genetically Engineered Food As Scientists commence the unraveling of genetic mysteries the food we eat is undergoing significant changes. From supermarket produce, milk and eggs to tofu, sprouts and garden burgers most have genetically altered ingredients. As with all new products tests are necessary. Guinea pigs, used in those tests, show the effects of the Genetically Engineered (GE) feed. So far the tests have shown elevated breast cancer from ingesting milk from cows consuming (GE) hormones. Others tests have shown possible deadly allergic reactions to foods altered with proteins from peanuts or shellfish. Most dramatically in 1989 and 1990, a (GE) brand of L-tryptophan, a common dietary supplement, killed more than thirty. Animal rights groups would normally protest these immoral experiments exposing them for what they are, wrong. Unfortunately, the guinea pigs, that are being fed this altered diet, have no voice, they are you and I. Americans are unknowingly consumer tons of (GE) food daily. Science and f ood have collided in the worst possible way. In just this last decade scientist have made epic strides altering plants and animals. Genetically altered products are found in our food, clothing and beverages. The lab has become the place where agricultural improvements are made. What all this means for the consumer is that we are allowed to make informed decisions and that must cease. The customer must at least be allowed to make a choice as to which food or beverage products they will consume. Currently foods that contain genetically altered ingredients are not required to differentiate themselves from non-altered foods. Manufactures continue to refuse all requests to label (GE) products. Genetically altered plants ... ... engineered crops threaten monarch butterflies." 21 Apr. 2000. http://www.bckweb.com/nerage/home.html Organic Gardening. Genetic Engineering: Answers and Actions One quarter of all U.S. farmland is growing GE crops, 93.75 million acres. Actions the organic gardener must take to stem the tide of altered crops. http://205.181.115.212/watchdog/geneng_Jan00.html Rifkin, Jeremy. Biotech Century: Playing Ecological Roulette with Mother Nature's Designs. The Presence of Others. Ed. Andrea Lunsford and John Ruszkiewicz. Boston: Bedford/ St. Martin, 2000. 244 - 254. Shelley, Mary. Frankenstein. New York, Tor books and 1805. Specter, Michael. "The Pharmageddon Riddle." The New Yorker. Apr. 10, 2000: 58 - 71. Steinbrecher, Dr. Ricarda. "What is Genetic Engineering?" Synthesis/Regeneration: A Magazine of Green Social Thought, Vol. 18. Winter 1999: 9 - 12.

Drinking and Driving Essay -- Drunk Driving, DUI, Alcohol

â€Å"Have one drink for the road† was, until recently, a commonly used phrase in American culture. It has only been within the past 20 years that as a nation, we have begun to recognize the dangers associated with drunk driving (Sutton 463). According to the National Highway Traffic Safety Administration, this year 519,000 people, or one person per minute, will be injured in alcohol-related accidents. 10,839 people will die in drunk-driving crashes this year – that is one death every 50 minutes. The heartbreaking part is, every injury and lost life due to driving after drinking can be prevented. Drinking while driving â€Å"accidents† are not merely â€Å"accidents.† Getting in a vehicle after consuming alcohol, which severely affects the function of the brain, is not an accident. It is lack of responsibility. Individuals that consume alcohol irresponsibly must begin to take responsibility for themselves and for other innocent drivers on the road. Unfort unately, in spite of great progress, alcohol-impaired driving remains a serious national problem that tragically affects many victims annually (Hanson). It is time that laws and consequences for drinking while driving strengthen and people begin to think twice before driving a vehicle after drinking. Individuals who make the decision to drive after consuming alcohol, not only put themselves in a dangerous situation, they also put an entire community at risk. Current laws, which are not strict or powerful enough, must be increased in order to keep our neighborhoods around the nation safe. Although many people think current drinking while driving limits and laws are strict enough, the rising number of individuals who continue to make an irresponsible decision to get behind the wheel of a vehicle ... ...king & Driving." WWW2 Webserver. State University of New York Sociology Department. Web. 5 Apr. 2011. Lightner, Candy. "Campaign to Eliminate Drunk Driving." Mothers Against Drunk Driving. 2011. Web. 01 Apr. 2011. Saunders, Carol Silverman. "'It's suicide.'(Drinking and Driving)." Current Health 2, a Weekly Reader publication Feb. 1996: 26+. Gale Opposing Viewpoints In Context. Web. 20 Apr. 2011. Sutton, Amy L. "Drinking and Driving." Alcoholism Sourcebook. Detroit, MI: Omnigraphics, 2007. 463. Print. "Update: Drunk Driving." Issues & Controversies On File: n. pag. Issues & Controversies. Facts On File News Services, 21 Sept. 2007. Web. 20 Apr. 2011. Wagner, Heather Lehr. Alcohol. Philadelphia: Chelsea House, 2003. Print. "What Is a Drink?" Arizona Department of Public Safety (DPS), Arizona Highway Patrol - State of Arizona. 2011. Web. 12 Apr. 2011.

Teen Britain: The shocking Truth(TM) article

Bullying, drugs, alcohol and sex were a few of the issues raised in this article, published on the 27th November 2005 as facing teenagers in today's society. As one of these young adults in our civilisation, I feel that it is my duty to defend myself and others like me in the face of such criticism. Firstly some of the points mentioned in your article I fully understand and agree with. For example, I agree that there are too many teenagers in society who are taking drugs or drinking alcohol whilst roaming our streets. You state that, â€Å"72% of 14 year olds have consumed alcohol†. This growing incidence of alcohol and drug use could also be a factor in the rise of the crime rate. However, I don't think that the press or general public can put all of the blame for this on today's teenagers, their families or the area in which they live. I think that the media has had a part to play in this and so should accept some of the blame. One of the reasons I think this, is that it wasn't so long ago that many newspapers and television documentaries claimed that cannabis didn't have any side effects or create long term damage; however, we are now being told by the media that there are serious side effects to cannabis, such as, that it the effects the quickness of the brain and how well you learn in class. Cannabis is proven to affect concentration spans so therefore pupils will not be able to take as much in during lessons. This may be one of the reasons for teenagers becoming addicted to drugs as they have been given mixed messages about the use and effects of them. In my opinion, the media is to blame for some of the negative behaviour that we are seeing from the teenagers of today. The main reason for my belief is that the media publicise a lot of the bad behaviour of teenagers; for example, young teenagers getting pregnant or drunk. However, I feel that the media very rarely praise teenagers for good behaviour and the achievement of some amazing goals. For example, good exam results, helping charities or helping out at home in difficult situations. Furthermore, some negative teenage behaviour, like smoking and drinking are activities shown on many popular television programmes, such as ‘Footballers Wives' and ‘Bad Girls'. After watching such programmes, some teenagers see these activities as cool and copy what they have watched. The media may also be influencing some teenagers to behave badly, as some of them crave to be famous and they feel that the only way to achieve this ambition is to do something delinquent, as they see these sorts of things getting attention every day. However, the media plays its part in the negative behaviour of teenagers in Britain today, so do a lot of people living in our country and indeed the laws we follow. It isn't the teenagers' fault that they believe that drinking alcohol will not harm them, as this is what they have been led to believe by our new licensing laws; These allow pubs and clubs to open for much longer and therefore make alcohol more readily available. Also the companies that are selling alcohol are partly to blame as they create new drinks which appeal to a younger market by making them taste more like soft drinks. Instead of marketing alcohol to teenagers people should be making young people aware of the dangers of alcohol and binge drinking. Adolescents should be advised to drink in small amounts and not go out binge drinking like these laws may encourage. Your article is extremely negative with its facts. You suggest that a percentage of teenagers have done something disapproving rather than celebrating the percentage of teenagers who have not. For example, instead of saying that â€Å"32% of 14 year olds have had sexual intercourse†, you could have said that 68% of 14 year olds have not had sexual intercourse. By being so negative you make teenagers sound as bad as you can, rather than praising the ones who aren't like this. This makes it far easier for the people reading your article to stereotype teenagers and jump to conclusions; however we are not all like you suggest. Finally, I would like to question the facts and statistics presented in this article as I don't always fully agree. I don't think that you have taken a big enough sample of teenagers in Britain, also I don't think that you have asked teenagers to complete your surveys in enough areas of Britain. Therefore, I question how you can support some of your statements as you seem to are stereotype all teenagers in Britain to be like the few you have spoken to. Would you like someone to go and speak to one or two people in your street and say you were the same as them? No, I didn't think you would. Well, is it fair that you have done this to the teenagers of Britain?

Good Soldiers Essay

Causes and Consequences In War and the Iliad, Simons well(p) and Rachel Bespangle offer opposing examine editions of the use of physical violence ( take up) against another(prenominal) person. The Good Soldiers considers force within the mount of the Iraq War. In response to these texts, what question or questions do you have about the causes and consequences of force in contemporary life, particularly in fight?For our first major essay, imitate a line of inquiry that explores the occupation of hysterical violence, particularly as it bring ups to our by nature texts. What leads us to use for CE? What are the consequences that follow from that choice? What role does caller plan y In our impartingness to digest or kill others? Are soldiers, who spring up paid to use force to simplicity Love conflict, heroes or victims in war? Offer these questions as examples of what you could study. Ultimately, you a creditworthy for the question that you final examize to explore.My only labour y our inquiry must(prenominal)iness relate to our course readings. Whatever question you decide to address, please incorporate at least(prenominal) two Of 0 our three authors into your essay. In addition, you must also incorporate at least five o outside(a) sources, either in support of your perspective or to help clarify the intellection of 10th note that your are meet to include anecdotes from your own life in your essay -? possibly in its introduction. press that you use templates from They Say, I Say in your body appear aphis to summarize, to quote, and/ r to comment on your evidence.You are composition for an audience that is unfamiliar with our texts, so you will need to summarize the m as you present your case, where necessary. Beyond that, the essay must follow MEAL and class change requirements. A forage rough plan is due on Tuesday, November 4. A gunk draft is due on Friday, November 7. The final draft is due at the bloodline of class on Tuesday, Nove mber 1 1, and must be at least octad pages long not including y our kit and boodle Cited page.