1.
Samsung Electronics
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(Korean, 삼성전자, Hanja, 三星電子 is a South Korean multinational electronics company headquartered in Suwon, South Korea. Through extremely complicated ownership structure with some circular ownership, it is the division of the Samsung Group. It is the second largest information technology company by revenue. Samsung Electronics has assembly plants and sales networks in 80 countries, since 2012, Kwon Oh-hyun has served as the companys CEO. It is the worlds largest manufacturer of mobile phones and smartphones fueled by the popularity of its Samsung Galaxy line of devices, Samsung has been the worlds largest television manufacturer since 2006, and the worlds largest manufacturer of mobile phones since 2011. Samsung Electronics is a part of the South Korean economy. Samsung Electric Industries was established as an industry Samsung Group in 1969 in Suwon and its early products were electronic and electrical appliances including televisions, calculators, refrigerators, air conditioners and washing machines. In 1970, Samsung Group established another subsidiary, Samsung-NEC, jointly with Japans NEC Corporation to manufacture home appliances, in 1974, the group expanded into the semiconductor business by acquiring Korea Semiconductor, one of the first chip-making facilities in the country at the time. The acquisition of Korea Telecommunications, a switching system producer, was completed at the start of the next decade in 1980. By 1981, Samsung Electric Industries had manufactured over 10 million black-and-white televisions, one year later, Samsung became the third company in the world to develop a 64 kb DRAM. Samsung Electronics launched its first mobile phone in 1988, in the South Korean market, sales were initially poor and by the early 1990s, Motorola held a market share of over 60 percent in the countrys mobile phone market compared to just 10 percent for Samsung. Samsungs mobile phone division also struggled with poor quality and inferior products until the mid-1990s, Lee Kun-Hee decided that Samsung needed to change strategy. The company shelved the production of many under-selling product lines and instead pursued a process of designing and manufacturing components, in addition, Samsung outlined a 10-year plan to shrug off its image as a budget brand and to challenge Sony as the worlds largest consumer electronics manufacturer. It was hoped in this way Samsung would gain an understanding of how products are made and this patient vertical integration strategy of manufacturing components has borne fruit for Samsung in the late-2000s. As Samsung shifted away from markets, the company devised a plan to sponsor major sporting events. One such sponsorship was for the 1998 Winter Olympics held in Nagano, Samsung had a number of technological breakthroughs, particularly in the field of memory which are commonplace in most electrical products today. This includes the worlds first 64Mb DRAM in 1992,256 Mb DRAM in 1994, in 2004, Samsung developed the worlds first 8Gb NAND Memory chip and a manufacturing deal was struck with Apple in 2005. In 2005, Samsung Electronics surpassed its Japanese rival, Sony, for the first time to become the worlds twentieth-largest and most popular consumer brand, in 2007, Samsung Electronics became the worlds second-largest mobile-phone maker, overtaking Motorola for the first time
2.
Form factor (mobile phones)
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The form factor of a mobile phone is its size, shape, and style, as well as the layout and position of its major components. There are three major form factors – bar phones, flip phones, and sliders – as well as sub-categories of these forms, a bar phone takes the shape of a cuboid, usually with rounded corners and/or edges. The name is derived from the resemblance to a chocolate bar in size. This form factor is used by a variety of manufacturers, such as Nokia. Bar type mobile phones commonly have the screen and keypad on a single face, the Samsung SPH-M620 has a unique bar style, offering different devices on either side of the bar, a phone on one side, and a digital audio player on the other. Sony Ericsson also had a well-known MarsBar phone model CM-H333, brick is a slang term almost always used to refer to large, outdated bar-type phones, typically early mobile phones with large batteries and electronics. Such early mobile phones, such as the Motorola DynaTAC, have been displaced by newer models which offer greater portability thanks to smaller antennas. A slate or touchscreen phone is a subset of the bar form that, like a computer, has few physical buttons, instead relying upon a touchscreen. The first commercially available touchscreen phone was the IBM Simon Personal Communicator, the iPhone released in 2007 is largely responsible for the influence and achievement of this design as it is currently conceived. Since mid-2010s almost all come in touchscreen slate form. The phablet or smartlet is a subset of the slate/touchscreen, which in turn is a subset of the bar form, a portmanteau of the words phone and tablet, phablets are a class of mobile device designed to combine or straddle the functions of a smartphone and tablet. Phablets typically have screens that measure between 5.5 and 7, a flip or clamshell phone consists of two or more sections that are connected by hinges, allowing the phone to flip open then fold closed in order to become more compact. When flipped open, the speaker and microphone are placed closer to the operators ear and mouth. When flipped shut, the phone becomes smaller and more portable than when it is opened for use. Motorola was once owner of a trademark for the flip phone. Motorola was the manufacturer of the famed StarTAC flip phone, in 2010, Motorola introduced a different kind of flip phone with its Backflip smartphone. When closed, one side is the screen and the other is a physical QWERTY keyboard, the hinge is on a long edge of the phone instead of a short edge, and when flipped out the screen is above the keyboard. Clamshell came to be used as generic for this form factor, flip phone referred to phones that opened on the vertical axis
3.
Smartphone
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A smartphone is a mobile phone with an advanced mobile operating system that combines features of a personal computer operating system with other features useful for mobile or handheld use. Smartphones can access the Internet and can run a variety of third-party software components and they typically have a color display with a graphical user interface that covers more than 76% of the front surface. In 1999, the Japanese firm NTT DoCoMo released the first smartphones to achieve mass adoption within a country, smartphones became widespread in the late 2000s. Most of those produced from 2012 onward have high-speed mobile broadband 4G LTE, motion sensors, in the third quarter of 2012, one billion smartphones were in use worldwide. Global smartphone sales surpassed the sales figures for regular cell phones in early 2013, devices that combined telephony and computing were first conceptualized by Nikola Tesla in 1909 and Theodore Paraskevakos in 1971 and patented in 1974, and were offered for sale beginning in 1993. Paraskevakos was the first to introduce the concepts of intelligence, data processing and they were installed at Peoples Telephone Company in Leesburg, Alabama and were demonstrated to several telephone companies. The original and historic working models are still in the possession of Paraskevakos, the first mobile phone to incorporate PDA features was a prototype developed by Frank Canova in 1992 while at IBM and demonstrated that year at the COMDEX computer industry trade show. It included PDA features and other mobile applications such as maps, stock reports. A refined version was marketed to consumers in 1994 by BellSouth under the name Simon Personal Communicator, the Simon was the first commercially available device that could be properly referred to as a smartphone, although it was not called that in 1994. The term smart phone appeared in print as early as 1995, in the mid-late 1990s, many mobile phone users carried a separate dedicated PDA device, running early versions of operating systems such as Palm OS, BlackBerry OS or Windows CE/Pocket PC. These operating systems would later evolve into mobile operating systems, in March 1996, Hewlett-Packard released the OmniGo 700LX, a modified HP 200LX palmtop PC that supported a Nokia 2110 phone with ROM-based software to support it. It had a 640×200 resolution CGA compatible four-shade gray-scale LCD screen and could be used to place and receive calls and it was also 100% DOS5.0 compatible, allowing it to run thousands of existing software titles, including early versions of Windows. In August 1996, Nokia released the Nokia 9000 Communicator, a cellular phone based on the Nokia 2110 with an integrated PDA based on the PEN/GEOS3.0 operating system from Geoworks. The two components were attached by a hinge in what known as a clamshell design, with the display above. The PDA provided e-mail, calendar, address book, calculator and notebook applications, text-based Web browsing, when closed, the device could be used as a digital cellular phone. In June 1999 Qualcomm released the pdQ Smartphone, a CDMA digital PCS Smartphone with an integrated Palm PDA, subsequent landmark devices included, The Ericsson R380 by Ericsson Mobile Communications. The first device marketed as a smartphone, it combined the functions of a phone and PDA. The Kyocera 6035 introduced by Palm, Inc, combining a PDA with a mobile phone, it operated on the Verizon network, and supported limited Web browsing
4.
Android (operating system)
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Android is a mobile operating system developed by Google, based on the Linux kernel and designed primarily for touchscreen mobile devices such as smartphones and tablets. In addition to devices, Google has further developed Android TV for televisions, Android Auto for cars. Variants of Android are also used on notebooks, game consoles, digital cameras, beginning with the first commercial Android device in September 2008, the operating system has gone through multiple major releases, with the current version being 7.0 Nougat, released in August 2016. Android applications can be downloaded from the Google Play store, which features over 2.7 million apps as of February 2017, Android has been the best-selling OS on tablets since 2013, and runs on the vast majority of smartphones. In September 2015, Android had 1.4 billion monthly active users, Android is popular with technology companies that require a ready-made, low-cost and customizable operating system for high-tech devices. The success of Android has made it a target for patent, Android Inc. was founded in Palo Alto, California in October 2003 by Andy Rubin, Rich Miner, Nick Sears, and Chris White. Rubin described the Android project as tremendous potential in developing smarter mobile devices that are aware of its owners location. The early intentions of the company were to develop an operating system for digital cameras. Despite the past accomplishments of the founders and early employees, Android Inc. operated secretly and that same year, Rubin ran out of money. Steve Perlman, a friend of Rubin, brought him $10,000 in cash in an envelope. In July 2005, Google acquired Android Inc. for at least $50 million and its key employees, including Rubin, Miner and White, joined Google as part of the acquisition. Not much was known about Android at the time, with Rubin having only stated that they were making software for mobile phones, at Google, the team led by Rubin developed a mobile device platform powered by the Linux kernel. Google marketed the platform to handset makers and carriers on the promise of providing a flexible, upgradeable system, Google had lined up a series of hardware components and software partners and signaled to carriers that it was open to various degrees of cooperation. Speculation about Googles intention to enter the communications market continued to build through December 2006. In September 2007, InformationWeek covered an Evalueserve study reporting that Google had filed several patent applications in the area of mobile telephony, the first commercially available smartphone running Android was the HTC Dream, also known as T-Mobile G1, announced on September 23,2008. Since 2008, Android has seen numerous updates which have improved the operating system, adding new features. Each major release is named in order after a dessert or sugary treat, with the first few Android versions being called Cupcake, Donut, Eclair. In 2010, Google launched its Nexus series of devices, a lineup in which Google partnered with different device manufacturers to produce new devices and introduce new Android versions
5.
Central processing unit
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The computer industry has used the term central processing unit at least since the early 1960s. The form, design and implementation of CPUs have changed over the course of their history, most modern CPUs are microprocessors, meaning they are contained on a single integrated circuit chip. An IC that contains a CPU may also contain memory, peripheral interfaces, some computers employ a multi-core processor, which is a single chip containing two or more CPUs called cores, in that context, one can speak of such single chips as sockets. Array processors or vector processors have multiple processors that operate in parallel, there also exists the concept of virtual CPUs which are an abstraction of dynamical aggregated computational resources. Early computers such as the ENIAC had to be rewired to perform different tasks. Since the term CPU is generally defined as a device for software execution, the idea of a stored-program computer was already present in the design of J. Presper Eckert and John William Mauchlys ENIAC, but was initially omitted so that it could be finished sooner. On June 30,1945, before ENIAC was made, mathematician John von Neumann distributed the paper entitled First Draft of a Report on the EDVAC and it was the outline of a stored-program computer that would eventually be completed in August 1949. EDVAC was designed to perform a number of instructions of various types. Significantly, the programs written for EDVAC were to be stored in high-speed computer memory rather than specified by the wiring of the computer. This overcame a severe limitation of ENIAC, which was the considerable time, with von Neumanns design, the program that EDVAC ran could be changed simply by changing the contents of the memory. Early CPUs were custom designs used as part of a larger, however, this method of designing custom CPUs for a particular application has largely given way to the development of multi-purpose processors produced in large quantities. This standardization began in the era of discrete transistor mainframes and minicomputers and has accelerated with the popularization of the integrated circuit. The IC has allowed increasingly complex CPUs to be designed and manufactured to tolerances on the order of nanometers, both the miniaturization and standardization of CPUs have increased the presence of digital devices in modern life far beyond the limited application of dedicated computing machines. Modern microprocessors appear in electronic devices ranging from automobiles to cellphones, the so-called Harvard architecture of the Harvard Mark I, which was completed before EDVAC, also utilized a stored-program design using punched paper tape rather than electronic memory. Relays and vacuum tubes were used as switching elements, a useful computer requires thousands or tens of thousands of switching devices. The overall speed of a system is dependent on the speed of the switches, tube computers like EDVAC tended to average eight hours between failures, whereas relay computers like the Harvard Mark I failed very rarely. In the end, tube-based CPUs became dominant because the significant speed advantages afforded generally outweighed the reliability problems, most of these early synchronous CPUs ran at low clock rates compared to modern microelectronic designs. Clock signal frequencies ranging from 100 kHz to 4 MHz were very common at this time, the design complexity of CPUs increased as various technologies facilitated building smaller and more reliable electronic devices
6.
Graphics processing unit
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GPUs are used in embedded systems, mobile phones, personal computers, workstations, and game consoles. In a personal computer, a GPU can be present on a video card, the term GPU was popularized by Nvidia in 1999, who marketed the GeForce 256 as the worlds first GPU, or Graphics Processing Unit. It was presented as a processor with integrated transform, lighting, triangle setup/clipping. Rival ATI Technologies coined the visual processing unit or VPU with the release of the Radeon 9700 in 2002. Arcade system boards have been using specialized graphics chips since the 1970s, in early video game hardware, the RAM for frame buffers was expensive, so video chips composited data together as the display was being scanned out on the monitor. Fujitsus MB14241 video shifter was used to accelerate the drawing of sprite graphics for various 1970s arcade games from Taito and Midway, such as Gun Fight, Sea Wolf, the Namco Galaxian arcade system in 1979 used specialized graphics hardware supporting RGB color, multi-colored sprites and tilemap backgrounds. The Galaxian hardware was used during the golden age of arcade video games, by game companies such as Namco, Centuri, Gremlin, Irem, Konami, Midway, Nichibutsu, Sega. In the home market, the Atari 2600 in 1977 used a video shifter called the Television Interface Adaptor,6502 machine code subroutines could be triggered on scan lines by setting a bit on a display list instruction. ANTIC also supported smooth vertical and horizontal scrolling independent of the CPU and it became one of the best known of what were known as graphics processing units in the 1980s. The Williams Electronics arcade games Robotron,2084, Joust, Sinistar, in 1985, the Commodore Amiga featured a custom graphics chip, with a blitter unit accelerating bitmap manipulation, line draw, and area fill functions. Also included is a coprocessor with its own instruction set, capable of manipulating graphics hardware registers in sync with the video beam. In 1986, Texas Instruments released the TMS34010, the first microprocessor with on-chip graphics capabilities and it could run general-purpose code, but it had a very graphics-oriented instruction set. In 1990-1992, this chip would become the basis of the Texas Instruments Graphics Architecture Windows accelerator cards, in 1987, the IBM8514 graphics system was released as one of the first video cards for IBM PC compatibles to implement fixed-function 2D primitives in electronic hardware. Fujitsu later competed with the FM Towns computer, released in 1989 with support for a full 16,777,216 color palette, in 1988, the first dedicated polygonal 3D graphics boards were introduced in arcades with the Namco System 21 and Taito Air System. In 1991, S3 Graphics introduced the S3 86C911, which its designers named after the Porsche 911 as an implication of the performance increase it promised. The 86C911 spawned a host of imitators, by 1995, all major PC graphics chip makers had added 2D acceleration support to their chips. By this time, fixed-function Windows accelerators had surpassed expensive general-purpose graphics coprocessors in Windows performance, throughout the 1990s, 2D GUI acceleration continued to evolve. As manufacturing capabilities improved, so did the level of integration of graphics chips, arcade systems such as the Sega Model 2 and Namco Magic Edge Hornet Simulator in 1993 were capable of hardware T&L years before appearing in consumer graphics cards
7.
Secure Digital
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Secure Digital is a non-volatile memory card format developed by the SD Card Association for use in portable devices. The standard was introduced in August 1999 by joint efforts between SanDisk, Panasonic and Toshiba as an improvement over MultiMediaCards, and has become the industry standard. The three companies formed SD-3C, LLC, a company that licenses and enforces intellectual property rights associated with SD memory cards and SD host, the companies also formed the SD Association, a non-profit organization, in January 2000 to promote and create SD Card standards. SDA today has about 1,000 member companies, the SDA uses several trademarked logos owned and licensed by SD-3C to enforce compliance with its specifications and assure users of compatibility. There are many combinations of factors and device families, although as of 2016. Secure Digital includes four card families available in three different sizes, the four families are the original Standard-Capacity, the High-Capacity, the eXtended-Capacity, and the SDIO, which combines input/output functions with data storage. The three form factors are the size, the mini size, and the micro size. Electrically passive adapters allow a card to fit and function in a device built for a larger card. The SD cards small footprint is a storage medium for smaller, thinner. The second-generation Secure Digital card was developed to improve on the MultiMediaCard standard, which continued to evolve, Secure Digital changed the MMC design in several ways, Asymmetrical slots in the sides of the SD card prevent inserting it upside down. Most SD cards are 2.1 mm thick, compared to 1.4 mm for MMCs. The SD specification defines a card called Thin SD with a thickness of 1.4 mm, the cards electrical contacts are recessed beneath the surface of the card, protecting them from contact with a users fingers. The SD specification envisioned capacities and transfer rates exceeding those of MMC, for a comparison table, see below. While MMC uses a pin for data transfers, the SD card added a four-wire bus mode for higher data rates. The SD card added Content Protection for Recordable Media security circuitry for digital rights management content-protection, full-size SD cards do not fit into the slimmer MMC slots, and other issues also affect the ability to use one format in a host device designed for the other. The Secure Digital High Capacity format, announced in January 2006 and defined in version 2.0 of the SD specification, the SDHC trademark is licensed to ensure compatibility. SDHC cards are physically and electrically identical to standard-capacity SD cards, Version 2.0 also introduces a High-speed bus mode for both SDSC and SDHC cards, which doubles the original Standard Speed clock to produce 25 MB/s. SDHC host devices are required to accept older SD cards, however, older host devices do not recognize SDHC or SDXC memory cards, although some devices can do so through a firmware upgrade
8.
Battery (electricity)
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An electric battery is a device consisting of one or more electrochemical cells with external connections provided to power electrical devices such as flashlights, smartphones, and electric cars. When a battery is supplying power, its positive terminal is the cathode. The terminal marked negative is the source of electrons that when connected to a circuit will flow. It is the movement of ions within the battery which allows current to flow out of the battery to perform work. Historically the term specifically referred to a device composed of multiple cells. Primary batteries are used once and discarded, the materials are irreversibly changed during discharge. Common examples are the battery used for flashlights and a multitude of portable electronic devices. Secondary batteries can be discharged and recharged multiple times using mains power from a wall socket, examples include the lead-acid batteries used in vehicles and lithium-ion batteries used for portable electronics such as laptops and smartphones. According to a 2005 estimate, the battery industry generates US$48 billion in sales each year. Batteries have much lower energy than common fuels such as gasoline. This is somewhat offset by the efficiency of electric motors in producing mechanical work. The usage of battery to describe a group of electrical devices dates to Benjamin Franklin, alessandro Volta built and described the first electrochemical battery, the voltaic pile, in 1800. This was a stack of copper and zinc plates, separated by brine-soaked paper disks, Volta did not understand that the voltage was due to chemical reactions. Although early batteries were of value for experimental purposes, in practice their voltages fluctuated. It consisted of a pot filled with a copper sulfate solution, in which was immersed an unglazed earthenware container filled with sulfuric acid. These wet cells used liquid electrolytes, which were prone to leakage and spillage if not handled correctly, many used glass jars to hold their components, which made them fragile and potentially dangerous. These characteristics made wet cells unsuitable for portable appliances, near the end of the nineteenth century, the invention of dry cell batteries, which replaced the liquid electrolyte with a paste, made portable electrical devices practical. Batteries convert chemical energy directly to electrical energy, a battery consists of some number of voltaic cells
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Lithium-ion battery
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A lithium-ion battery or Li-ion battery is a type of rechargeable battery in which lithium ions move from the negative electrode to the positive electrode during discharge and back when charging. Li-ion batteries use an intercalated lithium compound as one electrode material, the electrolyte, which allows for ionic movement, and the two electrodes are the constituent components of a lithium-ion battery cell. Lithium-ion batteries are common in home electronics and they are one of the most popular types of rechargeable batteries for portable electronics, with a high energy density, tiny memory effect and low self-discharge. Beyond consumer electronics, LIBs are also growing in popularity for military, battery electric vehicle, for example, lithium-ion batteries are becoming a common replacement for the lead–acid batteries that have been used historically for golf carts and utility vehicles. Chemistry, performance, cost and safety characteristics vary across LIB types, handheld electronics mostly use LIBs based on lithium cobalt oxide, which offers high energy density, but presents safety risks, especially when damaged. Lithium iron phosphate, lithium ion manganese oxide battery and lithium nickel manganese cobalt oxide offer lower energy density, such batteries are widely used for electric tools, medical equipment and other roles. NMC in particular is a contender for automotive applications. Lithium nickel cobalt aluminum oxide and lithium titanate are specialty designs aimed at particular niche roles, the newer lithium–sulfur batteries promise the highest performance-to-weight ratio. Lithium-ion batteries can pose unique safety hazards since they contain a flammable electrolyte, an expert notes If a battery cell is charged too quickly, it can cause a short circuit, leading to explosions and fires. Because of these risks, testing standards are more stringent than those for acid-electrolyte batteries, there have been battery-related recalls by some companies, including the 2016 Samsung Note 7 recall for battery fires. This article covers just the topics and general principles of lithium-ion batteries. Nearly all facets have elements that are impacted by currently very active development or research, a cell is a basic electrochemical unit that contains the basic components, such as electrodes, separator, and electrolyte. In the case of cells, this is the single cylindrical, prismatic or pouch unit. In this regard, the simplest battery is a cell with perhaps a small electronic circuit for protection. In many cases, distinguishing between cell and battery is not important, however, this should be done when dealing with specific applications, for example, battery electric vehicles, where battery may indicate a high voltage system of 400 V, and not a single cell. The term module is used as an intermediate topology, with the understanding that a battery pack is made of modules. In electrochemistry, the anode is the electrode where oxidation is taking place in the battery, i. e. electrons get free, however, this happens on opposite electrodes during charge vs. discharge. Historically, for lithium cells, which started as single use discharge cells and this is true on discharge, but with a rechargeable system, the negative electrode chemically becomes the cathode while charging
10.
Camera phone
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A camera phone is a mobile phone which is able to capture photographs. Most camera phones also record video, most camera phones are simpler than separate digital cameras. Their usual fixed-focus lenses and smaller sensors limit their performance in poor lighting, lacking a physical shutter, some have a long shutter lag. Photoflash is typically provided by an LED source which illuminates less intensely over a longer exposure time than a bright. Optical zoom and tripod screws are rare and none has a hot shoe for attaching an external flash, some also lack a USB connection or a removable memory card. Most have Bluetooth and WiFi, and can make geotagged photographs, some of the more expensive camera phones have only a few of these technical disadvantages, but with bigger image sensors, their capabilities approach those of low-end point-and-shoot cameras. In the smartphone era, the sales increase of camera phones caused point-and-shoot camera sales to peak about 2010. Most model lines improve their cameras every year or two, most smartphones only have a menu choice to start a camera application program and an on-screen button to activate the shutter. Some also have a camera button, for quickness and convenience. The principal advantages of camera phones are cost and compactness, indeed for a user who carries a mobile phone anyway, smartphones that are camera phones may run mobile applications to add capabilities such as geotagging and image stitching. However, the screen, being a general purpose control, lacks the agility of a separate cameras dedicated buttons. Nearly all camera phones use CMOS image sensors, due to reduced power consumption compared to CCD type cameras, which are also used. Some of camera phones even use more expensive Back Side Illuminated CMOS which uses energy lesser than CMOS, although more expensive than CMOS and CCD. The latest generation of cameras also apply distortion, vignetting. Most camera phones have a digital zoom feature, an external camera can be added, coupled wirelessly to the phone by Wi-Fi. They are compatible with most smartphones, images are usually saved in the JPEG file format, except for some high-end camera phones which have also RAW feature and the Android 5.0 Lollipop has facility of it. Windows Phones can be configured to operate as a camera if the phone is asleep. An external flash can be employed, to improve performance, Phones usually store pictures and video in a directory called /DCIM in the internal memory
11.
Wi-Fi
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Wi-Fi or WiFi is a technology for wireless local area networking with devices based on the IEEE802.11 standards. Wi-Fi is a trademark of the Wi-Fi Alliance, which restricts the use of the term Wi-Fi Certified to products that successfully complete interoperability certification testing. Devices that can use Wi-Fi technology include personal computers, video-game consoles, smartphones, digital cameras, tablet computers, digital audio players, Wi-Fi compatible devices can connect to the Internet via a WLAN network and a wireless access point. Such an access point has a range of about 20 meters indoors, hotspot coverage can be as small as a single room with walls that block radio waves, or as large as many square kilometres achieved by using multiple overlapping access points. Wi-Fi most commonly uses the 2.4 gigahertz UHF and 5 gigahertz SHF ISM radio bands, having no physical connections, it is more vulnerable to attack than wired connections, such as Ethernet. In 1971, ALOHAnet connected the Hawaiian Islands with a UHF wireless packet network, ALOHAnet and the ALOHA protocol were early forerunners to Ethernet, and later the IEEE802.11 protocols, respectively. A1985 ruling by the U. S. Federal Communications Commission released the ISM band for unlicensed use and these frequency bands are the same ones used by equipment such as microwave ovens and are subject to interference. In 1991, NCR Corporation with AT&T Corporation invented the precursor to 802.11, the first wireless products were under the name WaveLAN. They are the credited with inventing Wi-Fi. In 1992 and 1996, CSIRO obtained patents for a method used in Wi-Fi to unsmear the signal. The first version of the 802.11 protocol was released in 1997 and this was updated in 1999 with 802. 11b to permit 11 Mbit/s link speeds, and this proved to be popular. In 1999, the Wi-Fi Alliance formed as an association to hold the Wi-Fi trademark under which most products are sold. Wi-Fi uses a number of patents held by many different organizations. In April 2009,14 technology companies agreed to pay CSIRO $1 billion for infringements on CSIRO patents and this led to Australia labeling Wi-Fi as an Australian invention, though this has been the subject of some controversy. In 2016, the local area network Test Bed was chosen as Australias contribution to the exhibition A History of the World in 100 Objects held in the National Museum of Australia. The name Wi-Fi, commercially used at least as early as August 1999, was coined by the brand-consulting firm Interbrand, the Wi-Fi Alliance had hired Interbrand to create a name that was a little catchier than IEEE802. 11b Direct Sequence. Phil Belanger, a member of the Wi-Fi Alliance who presided over the selection of the name Wi-Fi, has stated that Interbrand invented Wi-Fi as a pun upon the word hi-fi. Interbrand also created the Wi-Fi logo, the yin-yang Wi-Fi logo indicates the certification of a product for interoperability
12.
Global Positioning System
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The Global Positioning System is a space-based radionavigation system owned by the United States government and operated by the United States Air Force. The GPS system operates independently of any telephonic or internet reception, the GPS system provides critical positioning capabilities to military, civil, and commercial users around the world. The United States government created the system, maintains it, however, the US government can selectively deny access to the system, as happened to the Indian military in 1999 during the Kargil War. The U. S. Department of Defense developed the system and it became fully operational in 1995. Roger L. Easton of the Naval Research Laboratory, Ivan A, getting of The Aerospace Corporation, and Bradford Parkinson of the Applied Physics Laboratory are credited with inventing it. Announcements from Vice President Al Gore and the White House in 1998 initiated these changes, in 2000, the U. S. Congress authorized the modernization effort, GPS III. In addition to GPS, other systems are in use or under development, mainly because of a denial of access. The Russian Global Navigation Satellite System was developed contemporaneously with GPS, GLONASS can be added to GPS devices, making more satellites available and enabling positions to be fixed more quickly and accurately, to within two meters. There are also the European Union Galileo positioning system and Chinas BeiDou Navigation Satellite System, special and general relativity predict that the clocks on the GPS satellites would be seen by the Earths observers to run 38 microseconds faster per day than the clocks on the Earth. The GPS calculated positions would quickly drift into error, accumulating to 10 kilometers per day, the relativistic time effect of the GPS clocks running faster than the clocks on earth was corrected for in the design of GPS. The Soviet Union launched the first man-made satellite, Sputnik 1, two American physicists, William Guier and George Weiffenbach, at Johns Hopkinss Applied Physics Laboratory, decided to monitor Sputniks radio transmissions. Within hours they realized that, because of the Doppler effect, the Director of the APL gave them access to their UNIVAC to do the heavy calculations required. The next spring, Frank McClure, the deputy director of the APL, asked Guier and Weiffenbach to investigate the inverse problem — pinpointing the users location and this led them and APL to develop the TRANSIT system. In 1959, ARPA also played a role in TRANSIT, the first satellite navigation system, TRANSIT, used by the United States Navy, was first successfully tested in 1960. It used a constellation of five satellites and could provide a navigational fix approximately once per hour, in 1967, the U. S. Navy developed the Timation satellite, which proved the feasibility of placing accurate clocks in space, a technology required by GPS. In the 1970s, the ground-based OMEGA navigation system, based on comparison of signal transmission from pairs of stations. Limitations of these systems drove the need for a more universal navigation solution with greater accuracy, during the Cold War arms race, the nuclear threat to the existence of the United States was the one need that did justify this cost in the view of the United States Congress. This deterrent effect is why GPS was funded and it is also the reason for the ultra secrecy at that time
