Reasons why the Proof for the Existence of God is Necessary Research Paper

Reasons why the Proof for the Existence of God is Necessary - Research Paper Example The thesis of this paper is principally on religion and the analysis of the company. It looks down to exhibiting the purpose of God in the companies’ welfare. In addition, the essay is worth reading, as it brings out cordial relations of the different employees in different departments. Further, it is due to God that companies manage operations with fewer constraints. The thesis is worth arguing about because without God, all operations fail. The universe as wide as it is depends on God and all living beings in it should know how they came into being. There exist five principal proofs for the existence of God. These are namely the proof that the universe had a beginning, the universe exhibit designs, there is a common morality for all human beings, the resurrection of Jesus, and a suggestion for the experience of the claims of Jesus. To begin with, it is clear that everything should have a cause and this therefore denotes the reason why the universe had a foundation (Goswami, 2008). God is the super founder of all beings. In making the universe, God used several unique means to bring out a clear picture of His (God) real self to individuals inhabiting the world. This denotes the reason why managers should view all employees as individuals of dignity. Purposely, God had a common value for all beings in the universe. The same way individuals in an organization should set common goals attainable by all employees. Christians should be accountable for arguments regarding the nature of God. All Christians have a common believe that Jesus Christ resurrected from the dead. This is significant to managers in that it imparts knowledge that despite the loopholes impeding the growth of the company, there are ways of developing the overall output. Proving the existence of God necessitates individuals to claim what Jesus Christ has done in their lives. Therefore, it is worth noting that the companies should exhibit positive deeds of the analysis work based on religiou s background. The argument regarding the proof of existence of God Company analysis refers to a phase where individuals deepen their thought to establish the problems facing the companies and determine solutions to the problems. Religion refers to the belief of some individuals to work under the control of a supernatural ruling being, God or gods. Religion is vital for the survival of the operations of the businesses established by individuals. Through religion, God the Supreme Being prevails in the worship centers. People respond differently to the sacred places where the adoration of God takes place. This is a source of power to enhance them obtain the ability to carry out distinguished tasks. God is the supernatural being in the universe believed to work with human beings to bring out several realistic goals. God exists purposely as a weapon used by particular individuals to perform specific tasks as required. It is important to consider God before carrying out any operations. Go d helps individuals to win over the other competing elements. Performance of company analysis is better after a realization of the existence of God. This is because Christians determine the profits of the companies without considering their own personal interests because of believing that God is watching over them. Due to the reason that individuals associate with various groups talking about a common enlightening being, people should have a goal for their primary reason to work with companies (Horn, 2010). They should establish and bring to light the reasons for carrying out an analysis of the company. On the contrary, it is worth arguing that God does not help individuals to

Analyzing stories Essay Example | Topics and Well Written Essays - 500 words

Analyzing stories - Essay Example Another reason was it was important for young Tengo to know the kind of work he did. Tengo often wondered why his father amongst all people treated him with so much cruelty and if he had the power, he could change a lot of things his life, starting with his father’s cruelty. However, this was only a wish. The story is symbolic to a town of cats, which is a strange place that everyone including Tengo wanders into and is unable to escape. Tengo would have wished to grow up like a normal child, having to help his father only a little and using the rest of his time playing with other children. However, he found himself in a world where despite being a child, he had to work and most of the time, could only watch other children play as he worked. Murakami points out that for Tengo, â€Å"Sunday was like a misshapen moon that showed only its dark side† (newyorker.com). While other children had stories to give on Mondays regarding how they spent their weekends, Tengo used to have none. Just like the town of cats, this kind of life was very hard to escape. He once tried to change the situation, a moment that he remembers after reading the story about the town of cats, but he only succeeded in getting free time on Sundays. The other aspects in his life, such as having to experience a lot of cruelty from a man he knew as his father did not change. Another instance where Tengo seems to wish things were different is when he wished his father could be different. He grew up an unhappy boy and often wondered why he was so different from his father. He did not resemble him in any way and had a high intellectual ability compared to him. While Tengo was a very curious boy, â€Å"his father showed no sign at all of what might be called intellectual curiosity† (Murakami, newyorker.com). The reason behind this was the lack of a biological tie between the two, and if things had been different, there would be a biological tie that would bring in

Identity of African American Men Essay Example for Free

Identity of African American Men Essay â€Å"No metaphor can capture completely the complexity of ethnic dynamics in the U. S. ‘Melting pot’ ignores the persistence and reconfiguration of the ethnicity over the generations. ‘Mosaic,’ much more apt for pluralistic societies such as Kenya or India, is too static a metaphor; it fails to take in to account the easy penetration of many ethnic boundaries. Nor is ‘salad bowl’ appropriate; the ingredients of a salad bowl are mixed but do not change. ‘Rainbow’ is a tantalizing metaphor, but rainbows disappear. ‘Symphony,’ like ‘rainbow,’ implies near perfect harmony; both fail to take into account the variety and range of ethnic conflict in the United States. The most accurately descriptive metaphor, the one that best explains the dynamics of ethnicity, is ‘kaleidoscope. ’ American ethnicity is kaleidoscopic, i. e. ‘complex and varied, changing form, pattern, color†¦ continually shifting from one set of relations to another; rapidly changing. ’ When a kaleidoscope is in motion, the parts give the appearance of relationships. The viewer sees and endless variety of variegated patterns, just as takes place on the American ethnic landscape. †- Lawrence Fuchs (Literature for Composition 1032) â€Å"Identity in America† was the theme chosen by my English 201 study group. This theme was taken from chapter twenty two of the Literature for composition: Reading and Writing Argument text book. However, I focused the broad theme of â€Å"Identity in America† to the more narrowed theme of â€Å"The Display of African American men in the media. † I chose this theme or topic because I felt that I can relate to it and as a matter of fact, it was also interesting to me. But in order to conduct my research on the particular topic, I came up with the following question, â€Å"How has the identity of African American men been displayed by the media: negatively or positively? † This question was chosen in order to provoke an argument for discussion. I conducted several interviews in order to acquire information about my selected topic. The media’s display of the identity of African American men can be discussed or looked at from two angles: negatively or positively. First, from my experience I can say that the media displays African American men in both lights, negatively and positively. But after conducting interviews with several individuals, my opinion has somewhat changed. I was always aware of the negative images of African/black men in the media. But I was not aware that this display had evolved overtime. My first interview was conducted with April T. Glasgow, a communications major at the University of the Virgin Islands on Wednesday 20th February 2008, at approximately ten o’clock in the morning. We conducted the interview at her dorm’s lobby. I had explained the topic prior to meeting with her, so she already had an idea about what issue the discussion would be addressing. Generally, her opinion was that black men were being exploited and portrayed negatively by the media. She also stated strongly that black men were too often portrayed or given the roles of thugs, gangsters, and pimps in films and magazines. In addition, a suggestion she made on how we could resolve this stereotype was that black people must unite and stand up against these negative portrayals especially those in rap music videos. The second interview was carried out that same day with Professor Alex Randall. His general statements were that the media has changed over the years. â€Å"The negative portrayals of the 1960’s and 1970’s have changed,† Randall stated. Randall felt that in modern times, people of color were treated more fairly and given a more positive portrayal in the media. Randall stated that there were many positive images in the media of African Americans, such as Denzel Washington, Barack Obama, Michael Jordan, and Bill Cosby. In addition, Randall said that in previous years no such image could have been seen in the media. â€Å"We are rational human beings and it’s our choice to choose what part of the spectrum of negative and positive images we would want to emulate,† said Randall. This statement impacted me and slightly changed my opinion on the topic. At that point in conducting my primary research for the paper, my position on the topic has somewhat been altered. After conducting the interviews with April T. Glasgow and Professor Alexander Randall I have become more open minded to the issue. I would admit that I was initially a bit biased and reserved on the topic prior to evaluating the topic from both sides; negatively and positively. In order to decide which position I was going to take I would have to do more secondary research on the topic. Since I started this research paper my observation and assessment of the media have taken a different turn. I now compare and contrast men of other races in the media to African American men. My secondary research was, for the most part, completed using internet sources. The articles that I discovered on the web were very useful and contributed greatly to my research. Three internet articles were analyzed to achieve the secondary data for my paper. The first article I examined was â€Å"The Media’s Bias against black men in America. † The article was basically a discussion of a piece written in the New York Times about the plight of American black men. The author, Armstrong Williams, stated that the New York Times article was another example of major media outlets using negative statistics to consistently cast black men as the scourge of this country. Williams made several strong and interesting statements throughout the article that I thought was beneficial to this research paper. For example, according to Williams, â€Å"The continual coverage of the black mans plight instead of his progress only hinders his growth, holds back our country from true equality, and hides the truth about the opportunities and challenges that we all face†(Williams  ¶4). Williams also suggested that the American public should challenge the lack of coverage of American black progress in this country (Williams  ¶5). â€Å"In the last century black men have literally gone from being slaves to business owners, government leaders, lawyers, doctors, firemen, generals, entertainers, and educators. No other oppressed class of people anywhere else in the world has advanced its standing in a society this quickly† (Williams  ¶6). I was really impressed by the way Armstrong used this statement to present his argument. In addition, Williams stated that the incidence of drug use, crime, scandal, divorce, and other social ills have increased dramatically for white men, but these statistics are not reported as problems about ‘white men in America (Williams  ¶6). â€Å"Approximately 9 out of 10 serial killers are white males between the ages of twenty and thirty five. Yet we never hear these statistics repeated over and over again in the mainstream press, making these crimes synonymous with one particular race as in this case with blacks† (Williams  ¶9). Later in the article Williams explained the image the media is creating internationally. The overseas media continuously places black men in negative positions such as school dropouts, irresponsible fathers, and victims of perpetual racism. The manner in which these stories are constructed and then, displayed to listeners and readers eliminates the possibility of believing that black men do not have positive roles (Williams  ¶10). Therefore, I agree with Williams that the repetitive negative articles can create a vicious cycle of harmful images and low expectations of black men. â€Å"The Black Image in the White Mind† is the title of the second internet article that I examined. The article was useful in constructing my opinion on the topic of how African American men are displayed in the media whether negatively or positively. The article presented some useful statistical data that was quite interesting and yet shocking to me. In this article by Robert M. Entman, he stated that a mug shot of a Black defendant is four times more likely to appear in a local television news report than of a White defendant (Entman  ¶2). He went on to say that the accused is two times more likely to be shown physically restrained in a local television news report than when the accused is a white man (Entman  ¶2). According to Entman, â€Å"The name of the accused is two times more likely to be shown on screen in a local TV news report if the defendant is black, rather than white† (Entman  ¶2). In addition, he stated that while black actors are now more visible in media, it is an open question as to how well they are being represented (Entman  ¶2). The Third article that I examined was â€Å"Black youth and mass media: current research and emerging questions† and I found it to be the most interesting of the three. This article was written by Craig Watkins, an Associate Professor of Sociology and Radio-Television- Film at the University of Texas at Austin. The article was basically an outline of some of the important research findings and emergent issues that examine the changing relationship between black American youth and the mass media industry (Watkins  ¶5). Watkins stated that for most of its history the mass media industry has produced images that distort and misrepresent the complexities of the African American experience (Watkins  ¶9). He stated that contemporary media representations of African Americans can be best described as paradoxical because blacks are simultaneously underrepresented and overrepresented in American media culture (Watkins  ¶9). According to Watkins, â€Å"blacks are underrepresented in many areas of mass media they are over represented in television sports broadcasts and crime and violence related portrayals† (Watkins  ¶13). Watkins said that images of blacks in magazines have increased but they are predominantly portrayed in athletic roles. According to Watkins, African American men are more likely to appear as athletes or musicians (Watkins  ¶14). The strongest statement throughout the article was when Watkins stated that the ‘athleticization’ of the black men in the media reproduces and popularizes long-standing myths about biological and intellectual differences between blacks and whites (Watkins  ¶15). Further analysis of Watkins’ article indicated that when African Americans are portrayed in television news it is generally in aggressive, violent, or criminal roles. Also, a recent analysis of the film industry asserts that blacks tend to be restricted to low budget features that focus disproportionately on crime, violence, and youth delinquency. The repetitious display of blacks in athletic roles creates a limited range of adult and professional role models for young black males being that they are faced with only few media images of successful African American men. The internet articles that I examined clearly showed that there is strong evidence to prove that African American men are negatively and unfairly displayed in the media. After examining these internet articles, I felt that even though they were some positive images of African American men in the media the majority of images are in some way biased or negative. After evaluating and examining my internet sources, I turned back my attention to my English 201 text book, Literature for Composition: Reading and Writing Arguments to get some more insight on the matter. While reading through chapter twenty-three, I came up on a quote from Lawrence Fuchs that I found to be tied in well with my overall all theme of identity in America. I decided to place this quote at the beginning of the research paper a sort of introduction to the overall theme. I chose this quote because it describes the complexity and internal conflicts of identity in America. Speaking of conflicts between identities, Hotel Rwanda is a film that displays such conflict to the extreme. This film was shown in class by my English professor because she said that it was in some way related to our theme and that it could also be used as a part of our secondary research. I did not really understand the connection with our theme until I saw the film. Hotel Rwanda is a historical drama about the hotel manager Paul Rusesabagina played by Don Cheadle during the Rwandan genocide and was directed by Terry George in 2004. The movie is actually based on the Rwandan genocide that occurred in 1994 where almost one million of both Tutsi and Hutu individuals were killed. In the movie which is a reflection of what actually took place, the media was used to instigate conflicts between the Tutsi and Hutu. Throughout the actual conflict the media was used as a tool to falsely display Tutsi’s as the scourge of Rwanda. For example, the radio station, RTLM was used to spread negative and hate messages about the Tutsis such as â€Å"Why do we hate the Tutsis? They are cockroaches†¦Rwanda is Hutu land. †(United Arts. Dir. Terry George. United States, 2004) All in all, it is quite evident from the primary and secondary research that there are both negative and positive displays of African American men in the media. Since the interviews I am more aware that the display of African Americans has changed over time for the better. However, from the Internet articles I have discovered that there are still a lot of negative images of African American men in the media. In addition, I learned that there are still many biases when presenting African American men in media whether on radio, television, or magazines. Overall, the research was very interesting and informative. April T. Glasgow and Professor Alexander Randall were very helpful in making my research paper a success. From carrying out this research paper I was able to conduct some interesting interviews, especially with Professor Randall. I was truly able to critically interpret and analyze the investigation in addition to improving my overall research skills. The research process was a learning experience that I will never forget. Works Cited Barnet, Sylvan, Burto William and Cain E. William. Literature for Composition. New York: Longman, 2007. Entman, Robert and Rojecki, Andrew. â€Å"Media and its Portrayal of Black Americans. † racerelations. about. com. New York. 2008. . Glasgow, April T. Personal Interview. 20 Feb. 2008. Hotel Rwanda. Dir. Terry George. Lions Gate Films and United Artists, 2004. Randall, Alexander. Personal Interview. 20 Feb. 2008. Watkins, S. Craig, â€Å"Black Youth and Mass Media: Current Research and Emerging Questions. † http://www. rcgd. isr. umich. edu/prba/perspectives/winter2000/cwatkins. pdf. Williams, Armstrong. â€Å"The Media’s Bias Against Black Men in America. † 31 March 2006. .

Free Space Optical (FSO) Communication

Free Space Optical (FSO) Communication INTRODUCTION Free Space Optical (FSO) communication involves the transmission of data through a wireless medium using modulated near infrared light beam (with wavelength between 800 nm-1700 nm) [1] as carrier wave. FSO communication links can be used for satellite-to-satellite cross links [2] [3], up-and-down links between space platforms- aircraft, ships, and other ground platforms, and among mobile and stationary terminals within the atmosphere [3]. Light as a medium of communication is not a recent innovation as it was used in the Roman era, where polished metal plates where used as mirrors to reflect sunlight for long-range signaling. A similar sunlight-powered device was used by the U.S. military to send telegraph information between mountain tops in the early 1800s [4]. Additional optical communication developments occurred during the World War II, and the post-war era experienced further developments in this field fueled by electronic innovations such as the transistors, vacuum tubes and i ntegrated circuits, and most especially the invention of the laser in the early 1960s [1]. The unique characteristics of laser such as its powerful coherent light beam, the possibility of modulating it at high frequency and the low beam divergence has made it the preferred light source for enhanced FSO applications. FSO communication is considered to be one of the key technologies for realizing very-high-speed multi-gigabit-per-second large-capacity communications when fibre optic cable is neither practical nor feasible [4]. FSO communication can be of crucial advantage particularly because of its wireless nature and several applications, making it a viable alternative to the laying of fiber cable underground which is expensive and has environmental consequences. Unlike radio and microwave systems, FSO has higher data rate due to its high carrier frequency, low power requirements, no frequency license required and much smaller packaging [4]. In FSO links, atmospheric turbulence is capable of degrading the wave-front quality of a signal-carrying laser beam, resulting in signal loss at the receiver and thereby impairing the link performance [4],[5]. In addition, fog, snow, rain, dust, smoke and other aerosol particles contribute to the attenuation of the signal-carrying beam and eventual degradation of the FSO link. Several studies have been done on the atmospheric turbulence channels of a FSO system [3], [5]. The real performance measure of an FSO communication system is provided by the binary error probability also referred to as Bit Error Rate (BER).FSO communication involve the use of optical amplifiers either as an optical booster or optical preamplification. Amplification is achieved by stimulated emission of photons from dopant ions in the dopant fibre by using a pump laser as used in Erbium Doped Fibre Amplifiers (EDFA) or electrically as used in semiconductor lasers, due to the excitation of ions from a higher ene rgy state to a lower energy state. The excited ions can also decay spontaneously (spontaneous emission) or even through non-radioactive processes involving interactions with phonons of the glass matrix. These last two decay mechanisms compete with stimulated emission reducing the efficiency of light amplification introducing what is known as the Amplified Spontaneous Emission (ASE) noise. Digital Pulse Position Modulation (DPPM) with direct-detection is the preferred modulation technique for FSO communication systems because of the lack of dispersion over the free space channel [2] , none requirement of threshold for detection [3] and the complexity associated with phase or frequency modulation [5]. At the moment, the benefits of FSO communications have not been fully exploited, hence more applied researches are needed at the laboratory to help transfer the performance of FSO optical systems into real life applications. CHAPTER TWO LITERATURE REVIEW 2.1 FSO – PRINCIPLES AND CLASSIFICATION A FSO system consists basically of a transmitter, usually a modulated laser or light emitting diode (LED) which produces light for conveying data through space, and a receiver such as a photodetector which receives close to collimated radiation independent of the transmitter pointing concentrated lens [1]. Other components include beam control optics, collection lens, optical amplifier, solar radiation filters and other electronics [6]. In general, FSO systems can be classified into indoor and outdoor FSO communication [4], [7] based on the distance covered for communication and the absence of environmental effects in the indoor FSO link. The basic operating principles of indoor point to point systems are not different from outdoor communication links but the designs are very different to accommodate various requirements. Some research on transmitter and receiver designs for long-range FSO communication systems, [8] like satellite and atmospheric optical communications, have already been reported, which might be beneficial to short-range systems. Recently, many indoor communication systems employ laser diode as light sources [8]. 2.1.1 INDOOR FSO COMMUNICATION The indoor FSO communication link can be further classified as point and shoot links which are subdivided into infrared data association (IRDA) and retro-reflect links; and networks which have two types namely the diffuse networks and line of sight networks [4],[7]. Indoor FSO applications are confined to short distances; hence it is appropriate to optical FSO systems that use wide divergence beams rather than narrow beams which are suitable for point to point systems. Such systems are sometimes referred to as optical telepoint systems [7]. Due to the fact that indoor FSO systems are not affected by atmospheric effects, the power budget depends solely on the transmitter launch power, free space loss, and receiver sensitivity. As reported in Mahdiraji and Zahedi [9], the use of infrared frequencies for short-range wireless communications has received extensive interest over the decade, and many potential applications of this technology have been suggested. Some of the applications inc lude portable device such as laptop computers, personal digital assistants, and portable telephones. Many indoor communication systems employing infrared LED wireless links have been reported in [7], [9]. Using pure diffuse link, a high speed and power efficient indoor wireless infrared communication using code combining was reported in Majumdar and Ricklin [4], where a multiple transmitter link design was used with a narrow field of view direction diversity receiver. The design goal was to eliminate the effect of inter symbol interference (ISI) so that power efficient signalling schemes such as DPPM can be employed at a very high data rate. A portable transceiver for indoor FSO link was reported by Jiang et al [8] .The system employs a transmitter of eye safe infrared LEDs and a receiver of photodiode arrays with multi channel trans-impedance-summer architecture. The received signal achieved a BER of 10-4 at a plane of 2 m away from the transmitter, even at a point 50 degree off the transmitters vertical axis. The bit rate of the transceiver was up to 40 Mbit/sec in an indoor non-directed infrared FSO link to be extended to 100 Mbit/s using LEDs with higher cut frequency. 2.2.2 OUTDOOR FSO COMMUNICATION Unlike the indoor FSO communication link, the outdoor link covers a long distance over 500 m [7] using the atmosphere as its natural medium of communication. It is unlikely that long distance point-to-point systems will exceed the 4-5 km range due to atmospheric channel degradation. Outdoor point-to-point systems use high power lasers that operate in the Class 3B eye safety band to achieve optimum power link budget, particularly if high bit rate (e.g., 155 Mb/s) is required [7]. In order to achieve an improved power budget, an experiment was carried out by Heatley et al [8] to achieve a trial 155 Mb/s link that cover a 4 km distance between Imperial College and University College London. The aim of the experiment was to minimize the overall propagation loss focussing on the free space loss and the receiver sensitivity as little could be done to reduce the atmospheric losses. A low power laser coupled to an erbium doped fibre amplifier (EDFA) was used as the source; two astronomical t elescopes (Schmidt-Cassegrain, 20 cm aperture) were used at both the source and receiver ends, and an Avalanche photodiode (APD) was used as receiver. The result of the experiment was that the diameter at the receiver was reduced to 0.5 m which corresponds to 8 dB free space loss from a beam diameter of 2 m (20 dB free space loss). The major problem encountered was maintaining the beam alignment which depends on temperature changes. Although the APD receiver is relatively costly, it helped to improve the receiver sensitivity and they are generally used for long distance systems. FSO is well established for intersatellite and deep-space communications [3] but it can also be used in ground-to-space link, Unmanned-Aerial-Vehicle (UAV) to ground link, and among mobile and stationary terminals within the atmosphere [10]. New areas of application include quantum key, traffic and telematics [6]. It has been predicted that FSO can be fruitfully utilized as alternative for last-mile problem [3], [10], [11]. According to Majumdar and Ricklin [4], a group of researchers reported the design and development of acquisition, tracking and pointing subsystem for UAV to ground free space optical communications link. The communication link was developed from a UAV to stationary ground stations located at Wrightwood, California and Maui, Hawaii. The range of the UAV was 50 km. the downlink laser transmitter wavelength was 1550 nm and had power of 200 mW for developing a 2.5 Gbps data rate communication for a BER of 10-9. Furthermore researchers have presented results from exper imental demonstrations using a very lightweight optical wavelength communication without laser in space (LOWCAL) [4] between ground based telescope and a space shuttle. The uplink/downlink established at 852 nm wavelength and 852 nm signal beam. Some of the specifications for the experiment were: range of 640 km, data rate of 10 kbps, telescope diameter of 0.6 m, modular weight of 2-4 kg and retro-reflector area of 70-180 cm2. For the downlink, differential circular polarization keying (DCPK) format was used while Frequency Shift keying was used for the uplink. Both the downlink and uplink achieved a BER 2.2 FSO- TECHNOLOGICAL ADVANTAGES AND CHALLENGES Theoretically, the wavelength range of the near infrared electromagnetic spectrum (800 nm and 1700 nm [1]) used in optical communication implies it offers extremely high bandwidth, hereby providing higher data rates compared to other communication media such as the radio (1 mm-100 Mm ) and microwave (1 mm-1 m) systems [1]. Further, this technology requires no spectrum licensing requirements i.e. traffic free bands, no mutual interference between the FSO systems (high spatial selectivity of the beam), no Fresnel Zone requirement and difficult to eavesdrop on transmitted data [4], [6], [10]. The integration of the optical wireless and fibre is a research area been worked on by my many researchers [4]. This integration is possible because the two optical technologies offer high—speed optical bandwidth to meet market needs. They both use the same optical transmission wavelength (800 nm – 1700 nm) [1]. In addition the two optical technologies both share the same system compo nents and can transmit digital information using a range of protocols. The business advantages of FSO communications for network extensions include the reduction of cost incurred on fibre-optic cable and other associated costs, as well as time for deployments [4]. Despite its potentials, FSO communication link is affected by atmospheric attenuation owing to aerosol particles such as fog, haze, rain and snow which causes fluctuations in both the intensity and the phase of the received light signal hereby limiting the availability of FSO for a given transmission range and increasing the systems bit error rate [5]. These includes the fine mode with diameter, less than 2.5  µm, the accumulation mode with particle diameters 0.1  µm  µm and the coarse mode with diameter > 2.5  µm [12]. These particles can grow in size in regions of high humidity, and shrink by evaporation as humidity decreases. The effect of atmospheric aerosols in the channel on laser beam propagation can be determined using the Mie theory which depends critically on wavelength and particle size [13]. The dimensionless size parameter illustrates the nature of the Mie calculation as it gives the relationship between the particle size and radiation wavelength. This is given m athematically in equation 2.1[13] as where is wave number, is particle radius and is particle wavelength. Table 2.1 adapted from Ricklin et al [13] show some sources of aerosol in the atmosphere. Aerosol particles can be classified into three modes based on the diameter of the particles. Table 2.2 adapted from OBrien et al [6] shows the attenuations caused by rain, snow and fog. Table 2.1 Estimates of particles smaller than 20 micron radius emitted into or formed in the atmosphere (106 metric tons/year) (adapted from [13]) *Includes unknown amounts of indirect man-made contributions. Table 2.2 Attenuations caused by rain, snow and fog (adapted from [6]) Extinction is a term which describes the attenuation of a laser beam as it passes through a medium containing atoms, molecules, and particles. As reported in Ricklin et al [13], Goody and Yung defined the fundamental law of extinction as that of Lambert, which states that â€Å"the extinction is linear in both intensity of radiation and in the amount of matter, provided that the physical state (i.e., temperature, pressure, composition) is held constant†. Intensive researches [3], [4], [5], [13] have been conducted on the effects of atmospheric losses, most especially atmospheric scintillation, on FSO communication and some solutions have been proffered to reduce these effects. 2.2.1 PROPAGATION LOSS This atmospheric loss is associated with the distance covered by the laser beam. According to Prokes [12], free space propagation loss can be expressed as shown in equation 2.2 [dB] (2.2) where L is the link path distance, is the beam divergence full angle and is the diameter of transmitting circular aperture. For the Gaussian beam and a sufficiently long link distance ( >>) the additional gain is = 3.7 dB. In Heatley et al [7], it was reported that for a point-to-point system that operate with a slightly diverging beam, the free space propagation loss would be 20 dB whereas in an indoor system using wide angle beam, the free space loss would be 40 dB or more. At very short link distances, the total transmitted power is detected at the receiver because the beam spot diameter at the receiver position is lower than the diameter of the receiver lens [12]. 2.2.2 PHYSICAL OBSTACLES Physical obstructions such as birds, insects, tree limbs, buildings or other factors can temporarily or permanently block the laser line-of-sight [6], [13]. Platform/building motion due to wind, differential heating and cooling, or ground motion over time can result in serious misalignment of fixed-position laser communication systems [13]. Proper planning and site measurements are ways of avoiding this effect [6]. 2.2.3 ABSORPTION AND SCATTERING Molecular absorption process which is wavelength dependent is a major factor in beam attenuation. At wavelengths greater than 1 µm, the effect of molecular extinction can be negligible as atoms couple weakly with electromagnetic field [4]. Furthermore, molecular absorptions at these wavelengths are due to absorption of incident radiation with only minor scattering contributions [4]. Aerosol scattering effect is caused by rain, fog, mist and snow. This effect accounts for the degradation in quality of service experienced during snow, rain, fog and mist as reported in a detailed measurement take by [7] over a period of one year in both rural and urban areas. The results also reported in Heatley et al [7], showed a similar trend but with rather less variability between seasons and higher average attenuations. For many molecules, the absorption spectra have been measured experimentally in the laboratory and the respective extinction ratios of specific molecules have been made available for evaluation [4]. Molecular absorption can be minimized by appropriate selection of the optical wavelength [4]. It has also been suggested in [7] that the attenuation effects due to scattering can be minimized by reducing the link range and/or reducing the optical power budget. The attenuation caused by scattering in decibel scale A10, scat is given by the product of the atmospheric attenuation coefficient ÃŽ ±10, scat and the link distance in kilometres. The mathematical expressions are shown in equations (2.3), (2.4) and (2.5) [12]. [dB/km] (2.3) Where is the particle size distribution coefficient defined as: [dB] (2.5) 2.2.4 ATMOSPHERIC SCINTILLATION Scintillation is caused by solar energy heating up small air pockets inhomogenously, thereby creating varying refractive index along the FSO link [7]. This results in the scattering of laser beams at various angles along the propagation path and a resultant fluctuation in both the intensity and phase of the received light [5], [7].Atmospheric scintillation is less significant at distances less than 500 m [7], [12], but degrades performance of a FSO link at ranges of the order of 1km or longer [5]. The intensity I of an optical wave propagating through turbulent atmosphere is a random variable. The normalized variance of optical wave intensity, referred to as the scintillation index, is defined by equation (2.6) [12] where the angular brackets denote an ensemble average. The scintillation index indicates the strength of intensity fluctuations. For weak fluctuations, it is proportional and, for strong fluctuations, it is inversely proportional to the Rytov variance for a plane which is shown in equation (2.7) [12] where is the refractive-index structure parameter. This parameter is dependent on temperature, humidity, atmospheric pressure, altitude and wind strength [12]. Beam wander is another occurrence in an atmospheric channel which causes similar effects as atmospheric scintillation. This is characterized by the deflection of the entire laser beam by optical tubules of larger diameter than the beam, resulting in a random movement of the light beam about the target point. Atmospheric scintillation is a major impairment of FSO communications systems, as it can produce large transient dips in the optical signal. It has been studied extensively with various theoretical models already proposed to describe the signal fading [3], [5], [11]. In addition, several communication techniques have been described to mitigate the signal fading effect [5], [6], [12], [13]. In [3], the error performance of terrestrial FSO links were modelled as PPM/Poisson channels in turbulent atmosphere. The scintillation effects were modelled as lognormal for weak turbulence and as exponential for heavy turbulence. In Kiasaleh [11], the performance of a direct-detection, APD-based PPM FSO communication system in atmospheric turbulence was characterized. Here the weak turbulence link was investigated by modelling the received signal as a log-normal random process and also as a negative exponentially distributed received signal intensity. The binary PPM was used as the modulation sch eme for the system. It was assumed that the receiver thermal noise is non-negligible and the average signal intensity was large enough to justify as Gaussian approximation. It was concluded that the performance of the APD-based PPM FSO system was severely affected by turbulence and that the optimum APD gain must be used to avoid excessive APD noise at the receiver. It was also concluded that the negative exponential channel scintillation affected the systems performance with only large signal power capable of influencing the performance. Zhu and Kahn [5] employed the statistical properties of signal fading, as a function of both temporal and spatial coordinates as an approach of mitigating turbulence-induced intensity fluctuation. In spatial domain technique, at least two receivers are used to collect the signal light at different angles. In temporal domain techniques, only one receiver is used. Here signal-by-signal maximum likelihood detector (ML) is used to optimize performance w hen the receiver knows only the marginal statistics of the fading while maximum-likelihood sequence detection (MLSD) is used when the receiver knows the temporal correlation of the fading. The investigation showed that BER has greater degradation when the standard deviation of the turbulence induced fading is large. Furthermore, the diversity reception with the two receivers can improve the performance than a single receiver. According to Prokes [12], the receiver lens area causes an integration of various intensities incident on particular parts of the lens. It was reported in [12] that optical scintillations can be reduced by increasing the collection area of the receiver lens. This phenomenon is known as aperture averaging and the aperture averaging factor for a spherical wave is shown in equation (2.8) [12] where is the power scintillation index and is the Rytov variance for the spherical wave. An experiment was carried out by Prokes [12] to investigate the effect of the aperture averaging factor on the power scintillation index using two different refractive index structure parameters for the calculation. The result showed that the influence of both the lens diameter and refractive-index structure parameter on the scintillation level was relatively large. The power link budget of a FSO communication link was given in [12] based on statistical analysis of the atmospheric attenuation. Figure 2.1 shows a power level diagram of FSO deployed at a distance of about 1 km. According to figure 1, the total received optical power, was given by Prokes [12] in equation (2.9) as where is the mean optical power of a laser diode, includes the coupling loss between the laser and the transmitter lens and the attenuation loss in the lens, is the beam attenuation due to propagation loss, includes random losses caused by atmospheric phenomena (scattering and turbulence), and represents the coupling lens between the receiver lens and photodiode and the attenuation and reflection at the lens. 2.2.5 AMPLIFIED SPONTANEOUS EMISSION (ASE) Optical amplifiers are important components in communication links, as they are used to boost output power levels in the order of one Watt and higher. Due to the atmosphere medium used in FSO, only optical booster and pre-amplification schemes can be used [14]. Apart from the desired optical signal amplification, the optical booster amplifier constitutes a source of background radiation that can exceed the background radiation from the sun. This radiation is called amplified spontaneous emission (ASE). The ASE power spectral density is represented in equation (2.10) [14] as where is one photon energy, denotes the optical amplifier gain, and is the amplifiers noise figure which ideally should be 3 dB. Equation (2.10) is valid for a single spatial mode (including polarization modes); in multimode applications has to be multiplied by the number of emitted modes to arrive at the total ASE power spectral density [14]. The effect of ASE radiation in optical booster and preamplification in FSO communication link was investigated by [14] using on/off keying (OOK) as the modulation technique. In the case of the booster amplifier, considering the fact that the maximum on-axis gain of a central unobscured optical transmit antenna with respect to an isolator radiator equals where is the diameter of the telescope optics and is the optical transmit wavelength .The value 0.81 is the optimum value of the fraction of incident power that can be coupled to an optical fibre from an incident plane wave. On inserting into equation (2.10), the ASE power spectral density generated by the booster amplifier and coupled to the receiver is given in equation (2.11) [14] as [W/Hz] (2.11) where is the transmitter gain, is the transmitter noise figure and and are the transmitter and receiver telescope diameter respectively. Also the signal power coupled to the receiver was given in equation (2.12) [14] as [W] (2.12) where is the transmit optical power at the output of the booster amplifier. Figure 2.2 [14] shows the general setup of an optically boosted FSO system. Modulated TX data Optical Receiver Optical booster amplifier GTX, FTX Telescope optics DTX Amplified data signal transmit booster ASE DRX R Using Erbium-doped booster amplifiers with specifications, telescope diameters, and a communication distance of , Winzer et al [14] arrived at which is of the order of the magnitude of the background radiation per mode produced by the sun. It also was reported that the booster ASE constitutes the dominating background radiation term up to communication distances of 600 000 km. In the optically preamplified FSO communication system, (see Figure 2.3) the received signal passes through polarization filter and optical bandpass which reduces the detected preamplifier ASE power. The preamplification introduces additional noise terms such as the shot noise, ASE-shot beat noise, signal-background beat noise, signal-ASE beat noise, background-preamplifier ASE beat noise, background-background beat noise and the ASE-ASE beat noise. It was reported by Winzer et al [14] that up to a link distance of 1000 km the beating of the signal and the transmit booster ASE dominates all other noise terms, c ausing the signal-to-noise ratio (SNR) to become independent of R. The communication quality does not in this case increase with decreasing communication distance. It was thus concluded that the optical booster ASE has significant impact on the performance of a FSO communication link, especially at short link distances [14]. Optical preamplifier POL- filter (optional) Optical bandpass Decision logic RX data In Winzer et al [14], the use of the pointing, acquisition and tracking (PAT) system (see figure 2.4) to reduce the optical booster ASE at the receiver was presented. The proposed patent-pending PAT system eliminates the need for the using separate power or hardware for beacon lasers, taking care of alignment procedures between the beacon-laser and the transmit or receive telescopes, and splitting off a certain fraction of the information carrying data signal for PAT purposes [14].The booster ASE is applicable to the PAT system because the ASE spectrum exceeds that of the data signal by orders of magnitude and also the ASE has the same spatial modes as the data signal. Figure 2.4 The PAT system retrieving pointing/tracking information from ASE emitted by the booster amplifier at the transmitter [14] Phillips et al[2] carried out an analysis of the optically preamplified intersatellite pulse position modulation (PPM) receiver employing maximum likelihood detection (MLD) using Gaussian approximation (GA) and Chernoff bound (CB) techniques. The results from the calculations carried out at a wavelength of and bit rate of 25 Mb/s showed that this mentioned receiver configuration is approximately 1.5 dB more sensitive than the optically preamplified OOK non-return-to zero (NRZ) signalling. This method is proposed to have future implementation in future laser intersatellite communication systems. This paper has been reviewed in my report, with special interest in the BER evaluation. 2.2.6 EYE SAFETY FSO systems involve the emission of high power optical power which can be unsafe, especially if operated incorrectly [7]. As a result of this, laser safety standards have been established and classified based on the amount of power emitted by the transmitter source. Table 2.3 (adapted from [7]) summarizes the principal classifications. Table 2.3 Laser safety classifications for point-to-source emitter (adapted from [7]) 650 nm (visible) 880 nm (infrared) 1310 nm (infrared) 1550 nm (infrared)

The Buddha, Two Lessons Essay -- essays research papers

Almost everybody I have ever met can recognize a Buddha statue, but few folks who I have ever associated with understand the meaning of the Buddha. Myself included was one of those folks blessed with such ignorance. When the term Buddha was brought up, all I thought about was the pudgy bellies of myself and fellow offensive lineman on my high school football team. Nirvana! Hey isn’t that one of the great rock bands of the early nineties? Right? In this paper, I will explain who the Buddha was and the deep meaning of the message that Prince Guatama preached. The Buddha defined the Middle Path as a way that leads to insight, which leads to wisdom, which conduces to calm, to knowledge, to the Sambodhi, to Nirvana (76). These words meant that all else was linked to some sort of suffering, that true peace and happiness could only be achieved through your mind and true pain and suffering could be achieved through reality. The Buddha illustrated this idea through his Four Noble Truths. The first of these is the Noble Truth of Suffering. These sufferings included natural situations of life, including birth, decay, death, presence of objects we hate not to obtain what we want, and finally, mere existence (76). There is a pattern that is developed in this order. Birth is the beginning of reality that has its good as well as bad times. The Buddha appears to focus on the hardships of reality that Prince Guatama knew of in this world. As life would carry onward, the hardships woul...

Cloud Computing Descends Essay -- Cloud Technology, United States, Job

An upgrade to cloud technology over the United States will potentially affect its workplace. It will lead to an increase in job creation all over the world, mostly due to its implementation at various institutions and companies globally and via many other services that will emerge to enhance or regulate this technology. In comparison to the initial machined technology, cloud computing offers instant delivery, simple & customizable usage, easy accessibility, cost reduction, thus increasing efficiency and demand and its wide range of acceptability. This technology, like any other, also has its disadvantages, though they are seemingly negligible in comparison. Cloud Technology is creating many jobs due to its implementation at most of the institutions such as the schools, companies, and even the government. This is to save expenses while increasing the overall efficiency and quality of their services. This will led to the formation of various additional services such as course instructions and certifications at educational institutions, and new companies to ensure the safety of cloud, thus creating more jobs. Even though its critics claim that this technology is decreasing the amount of jobs present in this field, but they fail to notice that the same amount of jobs are required to run the cloud technology and even more are created due to many of the cloud’s additional maintenance requirements. This is properly verified through many of the surveys including those of Microsoft which suggest that a large percentage of the hiring conducted by many tech companies are due to the Cloud Technology. The value of this market is also predicted to increase by six times its current value. As most people are aware of, there are various possibil... ...T Workforce."ZDNet.com. 2011. Opposing Viewpoints in Context. Web. 19 Feb. 2014. Stallman, Richard M. "Cloud Computing Threatens User Freedom and Should Be Avoided." Technology and the Cloud. Ed. David Haugen and Susan Musser. Detroit: Greenhaven Press, 2013. At Issue. Rpt. from "What Does that Server Really Serve?" Boston Review (18 Mar. 2010). Opposing Viewpoints in Context. Web. 19 Feb. 2014. "Year for business to look to the heavens - PREDICTIONS 2014 -." Australian [National, Australia] 25 Feb. 2014: 27. Opposing Viewpoints in Context. Web. 2 Mar. 2014. McClure, David. "Federal Policy Fosters Government Adoption of Secure Cloud Computing." Technology and the Cloud. Ed. David Haugen and Susan Musser. Detroit: Greenhaven Press, 2013. At Issue. Rpt. from "Cloud Computing: What Are the Security Implications." 2011. Opposing Viewpoints in Context. Web. 2 Mar. 2014. Cloud Computing Descends Essay -- Cloud Technology, United States, Job An upgrade to cloud technology over the United States will potentially affect its workplace. It will lead to an increase in job creation all over the world, mostly due to its implementation at various institutions and companies globally and via many other services that will emerge to enhance or regulate this technology. In comparison to the initial machined technology, cloud computing offers instant delivery, simple & customizable usage, easy accessibility, cost reduction, thus increasing efficiency and demand and its wide range of acceptability. This technology, like any other, also has its disadvantages, though they are seemingly negligible in comparison. Cloud Technology is creating many jobs due to its implementation at most of the institutions such as the schools, companies, and even the government. This is to save expenses while increasing the overall efficiency and quality of their services. This will led to the formation of various additional services such as course instructions and certifications at educational institutions, and new companies to ensure the safety of cloud, thus creating more jobs. Even though its critics claim that this technology is decreasing the amount of jobs present in this field, but they fail to notice that the same amount of jobs are required to run the cloud technology and even more are created due to many of the cloud’s additional maintenance requirements. This is properly verified through many of the surveys including those of Microsoft which suggest that a large percentage of the hiring conducted by many tech companies are due to the Cloud Technology. The value of this market is also predicted to increase by six times its current value. As most people are aware of, there are various possibil... ...T Workforce."ZDNet.com. 2011. Opposing Viewpoints in Context. Web. 19 Feb. 2014. Stallman, Richard M. "Cloud Computing Threatens User Freedom and Should Be Avoided." Technology and the Cloud. Ed. David Haugen and Susan Musser. Detroit: Greenhaven Press, 2013. At Issue. Rpt. from "What Does that Server Really Serve?" Boston Review (18 Mar. 2010). Opposing Viewpoints in Context. Web. 19 Feb. 2014. "Year for business to look to the heavens - PREDICTIONS 2014 -." Australian [National, Australia] 25 Feb. 2014: 27. Opposing Viewpoints in Context. Web. 2 Mar. 2014. McClure, David. "Federal Policy Fosters Government Adoption of Secure Cloud Computing." Technology and the Cloud. Ed. David Haugen and Susan Musser. Detroit: Greenhaven Press, 2013. At Issue. Rpt. from "Cloud Computing: What Are the Security Implications." 2011. Opposing Viewpoints in Context. Web. 2 Mar. 2014.

Evolution or Ignorance of Education

Throughout recent history creationists and evolutionists have argued whether evolution should be a part of America's public education. Whether evolution is science fact, or science fiction. Evolution being a science based on statistics has some faults, although many concepts in science or math do. The process of learning about evolution is a necessary part of a well-rounded student's education due to the fact that it is a statistically proven science and removing it in turn revokes certain student's rights. In a student's academic career that a student is most likely at one time or another going to have to take a science class. Science, being the main topic of discussion in this class, should at one point include evolution, because that is what evolution is, a science. Although to truly understand evolution in its fullest context, one must not look to a dictionary, for dictionary definitions just are too vague. One of the most respected evolutionary biologists has defined biological evolution as follows: â€Å"In the broadest sense, evolution is merely change, and so is all-pervasive; galaxies, languages, and political systems all evolve. Biological evolution †¦ is change in the properties of populations of organisms that transcend the lifetime of a single individual. The ontogeny of an individual is not considered evolution; individual organisms do not evolve. The changes in populations that are considered evolutionary are those that are inheritable via the genetic material from one generation to the next. Biological evolution may be slight or substantial; it embraces everything from slight changes in the proportion of different alleles within a population (such as those determining blood types) to the successive alterations that led from the earliest protoorganism to snails, bees, giraffes, and dandelions. † – Douglas J. Futuyma in Evolutionary Biology, Sinauer Associates 1986 All sciences are based on some form of proof. Whether it being living proof such as in Biology where one can observe cell division, mathematical proof such as in calculating air-resistance in Physics, or statistical proof as in all science experiments when a predicted result occurs again and again. All sciences have at least one of these qualities, including evolution. The proof of evolution's existence has been on this earth ever since life was formed from carbon based atom structures. Humans, however, have not been in existence long enough to observe properly the phenomena of evolution. Although by using the latest technology we can accurately observe the process of evolution as it occurred over time long ago and is still happening today. Charles Darwin, a British naturalist, made the first major step in classifying evolution during his studies in the Galapagos Archipelago in 1831 when he was only 22 years of age. Due to this he is credited with first forming a structured theory of evolution. During his studies in the Galapagos Archipelago he found a multitude of flora and fauna that had complete isolation from the rest of the world. One particular type of animal that he paid close attention to be a small bird called a Finch. This was thought as being simple at first, but as he traveled to the different islands he noticed many different species of finches. These finches probably descended from one type of ancestor and then, due to isolation and through chance, different climates and natural forces such as food availability and type, they evolved into many different types of finches. Some finches had different colorings, wingspan, and even beak style. In total he found thirteen different varieties of finches. Later on in Charles' life he formed many theories on the origins of man. This was directly related to his studies in the Galapagos Archipelago. In his book â€Å"Decent of Man† written in 1871 he declares why man had been so ignorant by denying evolution in the final parts of chapter one. â€Å"Thus we can understand how it has come to pass that man and all other vertebrate animals have been constructed on the same general model, why they pass through the same early stages of development, and why they retain certain rudiments in common. Consequently we ought rankly to admit their community of descent: to take any other view, is to admit that our own structure, and that of all the animals around us, is a mere snare laid to entrap our judgment. This conclusion is greatly strengthened, if we look to the members of the whole animal series, and consider the evidence derived from their affinities or classification, their geographical distribution and geological succession. It is only our natural prejudice, and that arrogance which made our forefathers declare that they were descended from demigods, which leads us to demur to this conclusion. But the time will before ong come, when it will be thought wonderful that naturalists, who were well acquainted with the comparative structure and development of man, and other mammals, should have believed that each was the work of a separate act of creation. † (Darwin) As seen in the above text, Charles Darwin explains how statistically man did evolve from a lower form of life. This is directly related to the finches due to that the same forces that caused them to evolve may have caused humans to evolve as well. Yet still some schools in America have tried banning the teaching of evolution in the classroom. Every student in a United States public school has a constitutional right to hear the whole story when it comes to evolution. It is called the first amendment in the Bill of Rights. According to the American Civil Liberties Union or ACLU, the authority on civil rights, states that every student has the right to a non-biased education (ACLU Urges†¦ ). In the Supreme Court decision Edwards v. Aguillard, 482 U. S. 578 (1987), the Court ruled that to compromise by omitting evolution and creationism from the science curriculum would â€Å"undermine the provision of a comprehensive scientific education. On this point, the law is very clear, and the Supreme Court put its foot down — the First Amendment forbids a state to alter its curriculum simply in order to defend a religious belief. That's an establishment of religion, and it's unconstitutional. (Edwards) So not only is removing evolution from the classroom unjustified, but it is against the law. Creationism has its place in the classroom as well as Evolutionism, although not the same classroom. Creationism belongs in a class like Theology or History of Religion. This is because creationism is the belief in the biblical account of the creation of the world. Biblical meaning the Bible, restricting it only to a group of religions. So-called â€Å"Creation Science† is not a science at all. Lately it has been more of a political movement than a science. Sure creationists may have facilities like the â€Å"Institute for Creation Research† (a church that does no scientific research at all) and the â€Å"Creation Research Society† (another church that also does no scientific research), but in the end there is not a shred of science in creation. Recently many science teachers in public schools have tried to work their way around teaching evolution by teaching a so called â€Å"intelligent design theory† (Washington State). This is just one of the many guises of creation science, and it does not change the fact that states and school districts may not adopt religious theories as standards in school curricula. Creationists will always exist, since ignorance will always exist, although evolution will always have a place in science curriculum. Creationists believe in creation because their masters have told them to believe in Creationism as a tool to their â€Å"salvation†. They do not care that evolution is an observed fact: they have â€Å"faith† that Creationism is true, and that's all they need. They consider facts and truth to be a hindrance to their ticket to Heaven. The teachings of these people should have no place, and will have no place in our children's science classrooms, only evolution and other proven sciences have the right to be present. Therefore, the process of learning about evolution is a necessary part of a well-rounded student's education due to the fact that it is a statistically proven science and removing it in turn revokes certain student's rights.