... during the cold war in 1969. It was developed by the US Department of Defense's (DOD) research people in conjunction with a number of military contractors and universities to explore the possibility of a communication network that could survive a nuclear attack. It continued simply because the DOD, DOD's contractors, and the universities found that it provided a very convenient way to communicate (Wendell). The ARPANET was a success from the very beginning. Although originally designed to allow scientists to share data and access remote computers, e-mail quickly becomes the most popular application. The ARPANET became a high-speed digital post-office as people ...
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... general pattern for the wireless link is as follows. Physical layer An RF carrier signal that is digitally modulated to create a bit stream. This bit stream incorporates forward error correction, interleaving and other techniques to mitigate the effects of interference and weak signals that can produce high-bit-error rates. Link layer Usually a specialized radio protocol that employs a form of medium access optimized for the radio environment. Most link protocols involve interactions between the wireless modem and a base station, and mobile units do not communicate directly with each other. Network layer Some wireless WANs, such as RAM Mobile Data and A ...
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... glass rods to illuminate the bodies' cavities. In 1895, french engineer Henry Saint-Rene designed a system of bent glass rods for guiding light images in an attempt at early television. In 1898, American David Smith applied for a patent on a bent glass rod device to be used as a surgical lamp. In the 1920's, Englishmen John Logie Baird and American Clarence W. Hansell patented the idea of using arrays of transparent rods to transmit images for television and facsimiles respectively. In 1930, German medical student, Heinrich Lamm was the first person to assemble a bundle of optical fibers to carry an image. Lamm's goal was to look inside inaccessible parts o ...
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... as they are, nanostructures require fine particles that can only be seen with the STM, or Scanning Tunneling Microscope (Dowie 4). Moreover the STM allows the scientists to not only see things at the molecular level, but it can pick up and move atoms as well (Port 128). Unfortunately the one device that is giving nanoscientists something to work with is also one of the many obstacles restricting the development of nanotech. The STM has been regarded as too big to ever produce nanotech structures (Port 128). Other scientists have stated that the manipulation of atoms, which nanotech relies on, ignores atomic reality. Atoms simply don't fit together in ways which ...
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... advantage of this force. Wings may be attached at the top, middle, or lower portion of the fuselage. These designs are referred to as high-, mid-, and low-wing, respectively. The number of wings can also vary. Airplanes with a single set of wings are referred to as monoplanes, while those with two sets are called biplanes. To help fly the airplane, the wings have two types of control surfaces attached to the rear, or trailing, edges. They are referred to as ailerons and flaps. Ailerons extend from about the midpoint of each wing outward to the tip. They move in opposite directions - when one aileron goes up, the other goes down. Flaps extend outward from ...
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... used. ORIGIN OF FIBER OPTICS Information (data and voice) is transmitted through the fiber digitally by the use of high speed LASERs (Light Amplification through the Simulated Emission of Radiation) or LEDs (Light Emitting Diodes). Each of these methods create a highly focused beam of light that is cycled on and off at very high speeds. Computers at the transmitting end convert data or voice into "bits" of information. The information is then sent through the fiber by the presence, or lack, of light. So, all of the data is sent light pulses. Computers on the receiving end convert the light back into data or voice, so it can be ...
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... layers of steel or a very hard ceramic, boron carbide. However, the discovery that numerous layers of nylon fabric could dissipate the energy of the bullet revolutionized the use of modern body armor. The function of steel or hard plastic armor is to be impervious to a bullet. The function of ceramic armor is to slow the bullet abruptly by the hardness of the ceramic and to dissipate the bullet's energy as it destroys the armor at the point of impact; the tiles or plates of ceramic bulletproof vest thus have to be replaced once they have stopped a bullet. The textile vest deforms the bullet and then dissipates its energy, entangling it in the vest's ...
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... engines and compression-ignition engines. In the former, a spark ignites a combustible mixture of air and fuel; in the latter, high compression raises the temperature of the air in the chamber and ignites the injected fuel without a spark. The diesel engine is a compression-ignition engine. This article emphasizes the spark-ignition engine. The invention and early development of internal-combustion engines are usually credited to three Germans. Nikolaus Otto patented and built (1876) the first such engine; Karl Benz built the first automobile to be powered by such an engine (1885); and Gottlieb Daimler designed the first high-speed internal- combu ...
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... utilities lays a far deeper, more involved problem than that of the other utilities. Each of these utilities have a high dependency on devices that have a high probability for not being Y2K compliant. These devices very nearlyd waste) are very much affected by Y2K. Problemed areas are found throughout the water infrastructure. Most obviously water utilities' computer systems will be affected by Y2K unless compliance is fulfilled. If the computers fail, the main areas affected would include customer service, accounts payable and receivable, databases, and management systems. Problems of this type are usually easily fixed, however the computer ...
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... or a view into a database. The user can interact with the world and directly manipulate objects within the world. Some worlds are animated by other processes, perhaps physical simulations, or simple animation scripts. Interaction with the virtual world, at least with near real time control of the viewpoint, in my opinion, is a critical test for a 'virtual reality'. Some people object to the term "Virtual Reality", saying it is an oxymoron. Other terms that have been used are Synthetic Environments, Cyberspace, Artificial Reality, Simulator Technology, etc. VR is the most common and sexiest. It has caught the attention of the media. The applications being d ...
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