A military technology

A military technology CDMA is a military technology first used during World War II by English allies to foil German attempts at jamming transmissions. The allies decided to transmit over several frequencies, instead of one, making it difficult for the Germans to pick up the complete signal. Because Qualcomm created communications chips for CDMA technology, it was privy to the classified information. Once the information became public, Qualcomm claimed patents on the technology and became the first to commercialize it. Code Division Multiple Access technology emerged as an alternative to the GSM cellular architecture and has shared in the past decades explosive growth in the wireless market. CDMA, like GSM, has seen incremental improvements in capacity throughout this period. Now both types of networks are making a transition to third-generation (3G) systems around the globe, offering yet more capacity and data services. INTRODUCTION With the advent of wireless communication there was the advent of the two technologies for the cellular communication. They were the CDMA and the GSM technology. Both the technologies have their own mechanisms of working and their own pros and cons for which they have their own different utilizations and implications.   Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  The technology on which our group has proposed to research is the CDMA (Code Division Multiple Access) technology. Though the total users of the CDMA technology around the globe are approximately 14% yet it has many advantages over the GSM technology which has enormous number of users. Actually the GSM technology is easy to manage and to handle rather than CDMA but that doesnt mean that it has got no future. Truly speaking the CDMA technology is the technology of the future. Gradually its gaining popularity in the European market. What is CDMA? CDMA (Code-Division Multiple Access) refers to any of several protocols used in so-called second-generation (2G) and third-generation (3G) wireless communications. As the term implies, CDMA is a form of multiplexing, which allows numerous signals to occupy a single transmission channel, optimizing the use of available bandwidth. The technology is used in ultra-high-frequency (UHF) cellular telephone systems in the 800-MHz and 1.9-GHz bands. CDMA employs analog-to-digital conversion (ADC) in combination with spread spectrum technology. Audio input is first digitized into binary elements. The frequency of the transmitted signal is then made to vary according to a defined pattern (code), so it can be intercepted only by a receiver whose frequency response is programmed with the same code, so it follows exactly along with the transmitter frequency. There are trillions of possible frequency-sequencing codes, which enhance privacy and makes cloning difficult. The CDMA channel is nominally 1.23 MHz wide. CDMA networks use a scheme called soft handoff, which minimizes signal breakup as a handset passes from one cell to another. The combination of digital and spread-spectrum modes supports several times as many signals per unit bandwidth as analog modes. CDMA is compatible with other cellular technologies; this allows for nationwide roaming. The original CDMA standard, also known as CDMA One and still common in cellular telephones in the U.S., offers a transmission speed of only up to 14.4 Kbps in its single channel form and up to 115 Kbps in an eight-channel form. CDMA2000 and wideband CDMA deliver data many times faster. Code Division Multiple Access (CDMA) is a digital air interface standard, claiming eight to fifteen times the capacity of traditional analog cellular systems. It employs a commercial adaptation of a military spread-spectrum technology. Based on spread spectrum theory, it gives essentially the same services and qualities as wireline service. The primary difference is that access to the local exchange carrier (LEC) is provided via a wireless phone. Though CDMAs application in cellular telephony is relatively new, it is not a new technology. CDMA has been used in many military applications, such as: Anti-jamming (because of the spread signal, it is difficult to jam or interfere with a CDMA signal). Ranging (measuring the distance of the transmission to know when it will be received). Secure communications (the spread spectrum signal is very hard to detect). CDMA is a spread spectrum technology, which means that it spreads the information contained in a particular signal of interest over a much greater bandwidth than the original signal. With CDMA, unique digital codes, rather than separate RF frequencies or channels, are used to differentiate subscribers. The codes are shared by both the mobile station (cellular phone) and the base station, and are called pseudo-random code sequences. Since each user is separated by a unique code, all users can share the same frequency band (range of radio spectrum). This gives many unique advantages to the CDMA technique over other RF techniques in cellular communication. CDMA is a digital multiple access technique and this cellular aspect of the protocol is specified by the Telecommunications Industry Association (TIA) as IS-95. In CDMA, the BSSAP is divided into the DTAP and BSMAP (which corresponds to BSSMAP in GSM). Generating a CDMA signal There are five steps in generating a CDMA signal. analog to digital conversion vocoding encoding and interleaving channelizing the signals conversion of the digital signal to a Radio Frequency (RF) signal The use of codes is a key part of this process. How CDMA is altering the face of cellular and PCS communication? CDMA is altering the face of cellular and PCS communication by: Dramatically improving the telephone traffic capacity Dramatically improving the voice quality and eliminating the audible effects of multipath fading Reducing the incidence of dropped calls due to handoff failures Providing reliable transport mechanism for data communications, such as facsimile and internet traffic Reducing the number of sites needed to support any given amount of traffic Simplifying site selection Reducing deployment and operating costs because fewer cell sites are needed Reducing average transmitted power Reducing interference to other electronic devices Reducing potential health risks Commercially introduced in 1995, CDMA quickly became one of the worlds fastest-growing wireless technologies. In 1999, the International Telecommunications Union selected CDMA as the industry standard for new third-generation (3G) wireless systems. Many leading wireless carriers are now building or upgrading to 3G CDMA networks in order to provide more capacity for voice traffic, along with high-speed data capabilities. CDMA is a form of Direct Sequence Spread Spectrum communications. In general, Spread Spectrum communications is distinguished by three key elements: The signal occupies a bandwidth much greater than that which is necessary to send the information. This results in many benefits, such as immunity to interference and jamming and multi-user access, which well discuss later on. The bandwidth is spread by means of a code which is independent of the data. The independence of the code distinguishes this from standard modulation schemes in which the data modulation will always spread the spectrum somewhat. The receiver synchronizes to the code to recover the data. The use of an independent code and synchronous reception allows multiple users to access the same frequency band at the same time. In order to protect the signal, the code used is pseudo-random. It appears random, but is actually deterministic, so that the receiver can reconstruct the code for synchronous detection. This pseudo-random code is also called pseudo-noise (PN). There are three ways to spread the bandwidth of the signal: Frequency hopping. The signal is rapidly switched between different frequencies within the hopping bandwidth pseudo-randomly, and the receiver knows before hand where to find the signal at any given time. Time hopping. The signal is transmitted in short bursts pseudo-randomly, and the receiver knows beforehand when to expect the burst. Direct sequence. The digital data is directly coded at a much higher frequency. The code is generated pseudo-randomly, the receiver knows how to generate the same code, and correlates the received signal with that code to extract the data. HOW SPREAD SPECTRUM WORKS? Spread Spectrum uses wide band, noise-like signals. Because Spread Spectrum signals are noise-like, they are hard to detect. Spread Spectrum signals are also hard to Intercept or demodulate. Further, Spread Spectrum signals are harder to jam (interfere with) than narrowband signals. These Low Probability of Intercept (LPI) and anti-jam (AJ) features are why the military has used Spread Spectrum for so many years. Spread signals are intentionally made to be much wider band than the information they are carrying to make them more noise-like. Spread Spectrum signals use fast codes that run many times the information bandwidth or data rate. These special Spreading codes are called Pseudo Random or Pseudo Noise codes. They are called Pseudo because they are not real Gaussian noise. Spread Spectrum transmitters uses similar transmit power levels to narrow band transmitters. Because Spread Spectrum signals are so wide, they transmit at a much lower spectral power density, measured in Watts per Hertz, than narrowband transmitters. This lower transmitted power density characteristic gives spread signals a big plus. Spread and narrow band signals can occupy the same band, with little or no interference. This capability is the main reason for all the interest in Spread Spectrum today. IMPLEMENTATION OF CDMA TECHNOLOGY Now a day, in large organization the communication process has to be fast and efficient. There are the major points that have to be taken care in the modern corporate culture. Over time, more and more demands have been made on the capabilities of corporate networks. Workers want more mobility; secure, high-speed access; and an extension of applications across the enterprise, all of which can strain current IT capabilities. The first and foremost of all is protecting corporate network assets is an ongoing task for IT professionals. Increased worker mobility and mobile workers needs for immediate, secure access to critical business information add challenges to maintaining network security Some of todays top security issues and concerns are: Unauthorized systems and network access Auditability and compliance Customer data breaches Internal and external sabotage Theft of intellectual property and confidential business information Cost of mobile device administration The following diagram illustrates many elements critical to mobile data security. DIFFERENCE BETWEEN GSM AND CDMA TECHNOLOGY In cellular service there are two main competing network technologies: Global System for Mobile Communications (GSM) and Code Division Multiple Access (CDMA). Cellular carriers including Sprint PCS, Cingular Wireless, Verizon and T-Mobile use one or the other. Understanding the difference between GSM and CDMA will allow you to choose a carrier that uses the preferable network technology for your needs. The GSM Association is an international organization founded in 1987, dedicated to providing, developing, and overseeing the worldwide wireless standard of GSM. CDMA, a proprietary standard designed by Qualcomm in the United States, has been the dominant network standard for North America and parts of Asia. However, GSM networks continue to make inroads in the United States, as CDMA networks make progress in other parts of the world. There are camps on both sides that firmly believe either GSM or CDMA architecture is superior to the other. That said, to the non-invested consumer who simply wants bottom line information to make a choice, the following considerations may be helpful. Coverage The most important factor is getting service in the areas you will be using your phone. Upon viewing competitors coverage maps you may discover that only GSM or CDMA carriers offer cellular service in your area. If so, there is no decision to be made, but most people will find that they do have a choice. Data Transfer Speed With the advent of cellular phones doing double and triple duty as streaming video devices, podcast receivers and email devices, speed is important to those who use the phone for more than making calls. CDMA has been traditionally faster than GSM, though both technologies continue to rapidly leapfrog along this path. Both boast 3G standards, or 3rd generation technologies. EVDO, also known as CDMA2000, is CDMAs answer to the need for speed with a downstream rate of about 2 megabits per second, though some reports suggest real world speeds are closer to 300-700 kilobits per second (kbps). This is comparable to basic DSL. As of fall 2005, EVDO is in the process of being deployed. It is not available everywhere and requires a phone that is CDMA2000 ready. GSMs answer is EDGE (Enhanced Data Rates for GSM Evolution), which boasts data rates of up to 384 kbps with real world speeds reported closer to 70-140 kbps. With added technologies still in the works that include UMTS (Universal Mobile Telephone Standard) and HSDPA (High Speed Downlink Packet Access), speeds reportedly increase to about 275à ¢Ãƒ ¢Ã¢â‚¬Å¡Ã‚ ¬380 kbps. This technology is also known as W-CDMA, but is incompatible with CDMA networks. An EDGE-ready phone is required. In the case of EVDO, theoretical high traffic can degrade speed and performance, while the EDGE network is more susceptible to interference. Both require being within close range of a cell to get the best speeds, while performance decreases with distance. Subscriber Identity Module (SIM) cards In the United States only GSM phones use SIM cards. The removable SIM card allows phones to be instantly activated, interchanged, swapped out and upgraded, all without carrier intervention. The SIM itself is tied to the network, rather than the actual phone. Phones that are card-enabled can be used with any GSM carrier. The CDMA equivalent, a R-UIM card, is only available in parts of Asia but remains on the horizon for the U.S. market. CDMA carriers in the U.S. require proprietary handsets that are linked to one carrier only and are not card-enabled. To upgrade a CDMA phone, the carrier must deactivate the old phone then activate the new one. The old phone becomes useless. Roaming For the most part, both networks have fairly concentrated coverage in major cities and along major highways. GSM carriers, however, have roaming contracts with other GSM carriers, allowing wider coverage of more rural areas, generally speaking, often without roaming charges to the customer. CDMA networks may not cover rural areas as well as GSM carriers, and though they may contract with GSM cells for roaming in more rural areas, the charge to the customer will generally be significantly higher. International Roaming If you need to make calls to other countries, a GSM carrier can offer international roaming, as GSM networks dominate the world market. If you travel to other countries you can even use your GSM cell phone abroad, providing it is a quad-band phone (850/900/1800/1900 MHz). By purchasing a SIM card with minutes and a local number in the country you are visiting, you can make calls against the card to save yourself international roaming charges from your carrier back home. CDMA phones that are not card-enabled do not have this capability, however there are several countries that use CDMA networks. Check with your CDMA provider for your specific requirements. According CDG.org, CDMA networks support over 270 million subscribers worldwide, while GSM.org tallies up their score at over 1 billion. As CDMA phones become R-UIM enabled and roaming contracts between networks improve, integration of the standards might eventually make differences all but transparent to the consumer. The chief GSM carriers in the United States are Cingular Wireless, recently merged with ATT Wireless, and T-Mobile USA. Major CDMA carriers are Sprint PCS, Verizon and Virgin Mobile. There are also several smaller cellular companies on both networks.

The impenetrability of life

An Interpretation of the Morals of Heinrich von Kleist’s The Earthquake in Chile Akin to most writers of the Romantic Movement, Heinrich von Kleist eschewed the Enlightenment’s belief in reason, science and progress. He believed that life was too complex for it to be interpreted by reason and science. The impenetrability of life, particularly com/literary-analysis-skills-lesson-structure/">human nature, is the central theme of Von Kleist’s short story The Earthquake in Chile (1807). Set in the wake of a fictitious earthquake in Chile, the short story reveals how man-made norms prove to be useless in moments of disaster.Thus, it is only in times of crisis that the true nature of individuals and or institutions is bared (Allan, 108). The earthquake is traditionally used as a metaphor for massive social upheaval. The manner in which it inflicts damage – from the bottom, destroying the foundations of edifices – renders it a suitable allegory of public c ataclysm. Reactionary priests interpreted the Lisbon earthquake of 1755 as a â€Å"punishment† for the supposed sins of its populace.The French philosopher Voltaire wrote in his novella Candide (1759) that the Roman Catholic Church used the said catastrophe as an excuse to burn more alleged heretics at the stake (The Internationalist, n. pag. ). The Scottish historian, essayist and satirist Thomas Carlyle referred to the French Revolution as â€Å"(an) earthquake of Insurrection† (Carlyle, 409). In The Earthquake in Chile, an earthquake temporarily halted the implacable operation of social, civil, moral and ecclesiastical law over society (Fenves, 313).Subsequent events exposed the futility of searching for assurance in life through reliance on loosely-argued metaphysical biases such as morals (Allan, 108). In the context of the short story, morals are detrimental to human society and relationships. It merely results in prejudices that allow the powerful to subjugate t he weak. From the outset, it is already clear to the reader that patriarchal structures of authority control Santiago. Power lies primarily in the hands of the viceroy, the Archbishop and the paterfamilias.In addition, women are perceived as valued sexual possessions and individuals whose intellect and morality must be dictated by men. But, ironically, it is women who are expected to control the sexual ardor of men (Allan, 109). Under the guise of â€Å"morality,† women are supposed to exhibit behavior that will protect her from unwanted sexual advances from men. If a woman is subjected to inappropriate sexual conduct by a man, it is believed to be her fault – she is a â€Å"loose† woman who does not deserve respect from men.When, for instance, Don Asteron discovered that Jeronimo is having an illicit affair with his daughter, Josephe, he sternly warned her instead of Jeronimo to end the relationship. And when Don Asteron later found out through Josephe’s brother that she and Jeronimo continued their liaison, he had her banished to a convent. Josephe’s new â€Å"spiritual father,† the Archbishop, proved to be more unforgiving – he insisted that she be put to trial and condemned to death after she gave birth during the religious procession.Both Don Asteron and the Abbess strongly opposed the death sentence, to no avail (Allan, 110). The decision to commute Josephe’s sentence from burning at the stake to beheading resulted in â€Å"indignation (from) the matrons and maidens of Santiago† (Von Kleist, 175). Because they committed themselves to the patriarchal values of feminine innocence and impeccable chastity, they believed that no punishment could be too severe for a woman like her. Furthermore, a gory execution for Josephe would allow them to bask in the illusory sense of their own moral superiority.Her burning at the stake would affirm their belief that they were â€Å"good† women and she w as an â€Å"indecent† woman (Allan, 111). The earthquake, however, transformed Santiago into an entirely different society. The catastrophe destroyed the bastions of patriarchal authority – the cathedral, the Viceroy’s palace, the court, the house of Josephe’s father and the prison. As a result, the people finally learned to work side by side in order to survive. Differences in social class, gender and religion were disregarded to attain the common goal of survival:And, indeed, in the midst of these awful moments, in which all the earthly goods of man were destroyed and all of nature was threatened with burial, the human spirit seemed to open out like a beautiful flower. In the fields, as far as the eye could reach, people of all ranks could be seen mingled together, princes and beggars, matrons and peasant women, bureaucrats and laborers, monks and nuns. They sympathized with one another, assisted one another and cheerfully shared whatever they had been able to save to keep themselves alive, as if the universal calamity had made a single family of all who had escaped it.(180) For Jeronimo, Josephe and their son Philipp, help came in the form of Don Fernando and his wife Dona Elvira. After Josephe agreed to Don Fernando’s request that she be the wet nurse of his son Juan (Dona Elvira was badly injured in the earthquake), he welcomed her, Jeronimo and Philipp into his family. Don Fernando and Dona Elvira treated them well despite their background: Don Fernando was very grateful for this kindness (Josephe’s consent to become Juan’s wet nurse) and asked whether they did not wish to accompany him to that group of people who were just preparing a small breakfast by the fire.Josephe replied that she would accept that invitation with pleasure, and, since Jeronimo had no objection either, she followed Don Fernando to his family and was received most heartily and tenderly by his two sisters-in-law, whom she knew to be ve ry respectable young ladies. (179) Dona Elvira, to whose wounds Josephe was busily attending, had at one point – just when these stories were arriving most quickly, each interrupting the other – taken the opportunity to ask her how she had fared on that terrible day. And when, withanguished heart, Josephe recounted some of the main features of her story, she was delighted to see tears well up in that lady’s eyes; Dona Elvira seized her hand and squeezed it and gestured her to be silent. (180) Unfortunately, the rest of the town retained its bigotry. In the afternoon of the earthquake, a service was held at Santiago’s remaining cathedral. The sermon of the officiating priest likened the calamity to God’s annihilation of Sodom and Gomorrah. The earthquake, according to him, was God’s â€Å"punishment† to Santiago for Jeronimo and Josephe’s sin:He castigated it (the city) for abominations such as Sodom and Gomorrah had not known, and ascribed it only to God’s infinite forbearance that Santiago had not been totally obliterated from the face of the earth†¦he†¦digressed, with copious imprecations, to mention the two sinners themselves by name and to consign their souls to all the princes in hell. (183-184) The heady rhetoric of the sermon, along with emotional intensity generated by the devastating effects of the earthquake, resulted in violence. When a member of the congregation recognized Josephe in the service, an angry mob went after her and her companions.When the crowd dispersed, Jeronimo, Josephe, Juan and Dona Constancia (Don Fernando’s sister-in-law) lay dead. The Earthquake in Chile was Von Kleist’s explanation for his disbelief in the ability of science, reason and progress to influence life and humanity. He believed that science, reason and progress governed life and humanity through morals that were in favor of the powerful. The powerful, in turn, used these morals to exploit the weak and the helpless. Thus, when the powerful loses their ability to subjugate, they resort to diabolical means to regain this capability. In doing so, their real nature is exposed.Works Cited Allan, Sean. The Stories of Heinrich von Kleist: Fictions of Security. New York: Boydell & Brewer, 2001. Carlyle, Thomas. The French Revolution: A History. New York: Modern Library, 2002. Fenves, Peter David. Arresting Language: From Leibniz to Benjamin. Palo Alto: Stanford University Press, 2001. â€Å"Lisbon, 1755: The Earth Shook. † January 2005. The Internationalist. 17 September 2008. <http://www. internationalist. org/lisbon1755. html>. Von Kleist, Heinrich. â€Å"The Earthquake in Chile. † Great German Short Stories. Ed. Evan Bates. New York: Courier Dover Publications, 2003.

ACT Score Comparison for Admission to Kentucky Colleges

The Hippocampus in the Limbic System

The hippocampus is the part of the brain that is involved in forming, organizing, and storing memories. It is a limbic system structure that is particularly important in forming new memories and connecting emotions and senses, such as smell and sound, to memories. The hippocampus is a horseshoe shaped  structure, with an arching band of nerve fibers (fornix) connecting the hippocampal structures in the left and right brain hemispheres. The hippocampus is found in the brains temporal lobes and acts as a memory indexer by sending memories out to the appropriate part of the cerebral hemisphere for long-term storage and retrieving them when necessary. Anatomy The hippocampus is the main structure of the hippocampal formation, which is composed of two gyri (brain folds) and the subiculum. The two gyri, the dentate gyrus and Ammons horn (cornu ammonis), form interlocking connections with one another. The dentate gyrus is folded and nestled within the hippocampal sulcus (brain indentation). Neurogenesis (new neuron formation) in the adult brain occurs in the dentate gyrus, which receives input from other brain areas and aids in new memory formation, learning, and spacial memory. Ammons horn is another name for the hippocampus major or hippocampus proper. It is divided into three fields (CA1, CA2, and CA3) that process, send, and receive input from other brain regions. Ammons horn is continuous with the subiculum, which acts as the main output source of the hippocampal formation. The subiculum connects with the parahippocampal gyrus, a region of the cerebral cortex that surrounds the hippocampus. The parahippocampal gyrus is involved in memor y storage and recall. Function The hippocampus is involved in several functions of the body including: Consolidation of New MemoriesEmotional ResponsesNavigationSpatial Orientation The hippocampus is important for converting short-term memories into long-term memories. This function is necessary for learning, which relies on memory retention and proper consolidation of new memories. The hyppocampus plays a role in spatial memory as well, which involves taking in information about ones surroundings and remembering locations. This ability is necessary in order to navigate ones environment. The hippocampus also works in concert with the amygdala to consolidate our emotions and long-term memories. This process is critical for evaluating information in order to respond appropriately to situations. Location Directionally, the hippocampus is located within the  temporal lobes, adjacent to the  amygdala. Disorders As the hippocampus is linked to cognitive ability and memory retention, people who experience damage to this area of the brain have difficulty recalling events.  The hippocampus has been the focus of attention for the medical community as it relates to memory disorders such as Post Traumatic Stress Disorder, epilepsy, and Alzheimers disease. Alzheimers disease,  for example, damages the hippocampus by causing tissue loss. Studies have shown that Alzheimers patients who maintain their cognitive ability have a larger hippocampus than those with dementia. Chronic seizures, as experienced by individuals with epilepsy, also damage the hippocampus, causing amnesia and other memory-related problems.  Prolonged emotional stress negatively impacts the hippocampus as stress causes the body to release cortisol, which can damage neurons of the hippocampus. Alcohol is also thought to negatively impact the hippocampus when consumed in excess. Alcohol influences certain neurons in the hippocampus, inhibiting some brain receptors and activating others. These neurons manufacture steroids which interfere with learning and memory formation resulting in alcohol-related blackouts. Heavy long term drinking has also been shown to lead to tissue loss in the hippocampus. MRI scans of the brain indicate that alcoholics tend to have a smaller hippocampus than those who are not heavy drinkers. Divisions of the Brain Forebrain - encompasses the cerebral cortex and brain lobes.Midbrain - connects the forebrain to the hindbrain.Hindbrain - regulates autonomic functions and coordinates movement. References Alcoholism: Clinical Experimental Research. (2006, October 25). Heavy, Chronic Drinking Can Cause Significant Hippocampal Tissue Loss. ScienceDaily. Retrieved August 29, 2017 from www.sciencedaily.com/releases/2006/10/061025085513.htmWashington University School of Medicine. (2011, July 10). The biology behind alcohol-induced blackouts. ScienceDaily. Retrieved August 28, 2017 from www.sciencedaily.com/releases/2011/07/110707092439.htm