A Linux distribution is an operating system made from a software collection, based upon the Linux kernel and a package management system. Linux users obtain their operating system by downloading one of the Linux distributions, which are available for a wide variety of systems ranging from embedded devices and personal computers to powerful supercomputers. A typical Linux distribution comprises a Linux kernel, GNU tools and libraries, additional software, documentation, a window system, a window manager, a desktop environment. Most of the included software is free and open-source software made available both as compiled binaries and in source code form, allowing modifications to the original software. Linux distributions optionally include some proprietary software that may not be available in source code form, such as binary blobs required for some device drivers. A Linux distribution may be described as a particular assortment of application and utility software, packaged together with the Linux kernel in such a way that its capabilities meet the needs of many users.
The software is adapted to the distribution and packaged into software packages by the distribution's maintainers. The software packages are available online in so-called repositories, which are storage locations distributed around the world. Beside glue components, such as the distribution installers or the package management systems, there are only few packages that are written from the ground up by the maintainers of a Linux distribution. Six hundred Linux distributions exist, with close to five hundred out of those in active development; because of the huge availability of software, distributions have taken a wide variety of forms, including those suitable for use on desktops, laptops, mobile phones and tablets, as well as minimal environments for use in embedded systems. There are commercially backed distributions, such as Fedora, openSUSE and Ubuntu, community-driven distributions, such as Debian, Slackware and Arch Linux. Most distributions come ready to use and pre-compiled for a specific instruction set, while some distributions are distributed in source code form and compiled locally during installation.
Linus Torvalds developed the Linux kernel and distributed its first version, 0.01, in 1991. Linux was distributed as source code only, as a pair of downloadable floppy disk images – one bootable and containing the Linux kernel itself, the other with a set of GNU utilities and tools for setting up a file system. Since the installation procedure was complicated in the face of growing amounts of available software, distributions sprang up to simplify this. Early distributions included the following: H. J. Lu's "Boot-root", the aforementioned disk image pair with the kernel and the absolute minimal tools to get started, in late 1991 MCC Interim Linux, made available to the public for download in February 1992 Softlanding Linux System, released in 1992, was the most comprehensive distribution for a short time, including the X Window System Yggdrasil Linux/GNU/X, a commercial distribution first released in December 1992The two oldest and still active distribution projects started in 1993; the SLS distribution was not well maintained, so in July 1993 a new distribution, called Slackware and based on SLS, was released by Patrick Volkerding.
Dissatisfied with SLS, Ian Murdock set to create a free distribution by founding Debian, which had its first release in December 1993. Users were attracted to Linux distributions as alternatives to the DOS and Microsoft Windows operating systems on IBM PC compatible computers, Mac OS on the Apple Macintosh, proprietary versions of Unix. Most early adopters were familiar with Unix from school, they embraced Linux distributions for their low cost, availability of the source code for most or all of the software included. The distributions were a convenience, offering a free alternative to proprietary versions of Unix but they became the usual choice for Unix or Linux experts. To date, Linux has become more popular in server and embedded devices markets than in the desktop market. For example, Linux is used on over 50% of web servers, whereas its desktop market share is about 3.7%. Many Linux distributions provide an installation system akin to that provided with other modern operating systems. On the other hand, some distributions, including Gentoo Linux, provide only the binaries of a basic kernel, compilation tools, an installer.
Distributions are segmented into packages. Each package contains service. Examples of packages are a library for handling the PNG image format, a collection of fonts or a web browser; the package is provided as compiled code, with installation and removal of packages handled by a package management system rather than a simple file archiver. Each package intended for such a PMS contains meta-information such as a package description, "dependencies"; the package management system can evaluate this meta-information to allow package searches, to perform an automatic upgrade to a newer version, to check that all dependencies of a package are fulfilled, and/or to fulfill them automatically. Alth
Hürriyet is one of the major Turkish newspapers, founded in 1948. As of January 2018, it had the highest circulation of any newspaper in Turkey at around 319,000. Hürriyet has a mainstream and conservative outlook. Hürriyet's editorial line may be considered middle-market, combining entertainment value with comprehensive news coverage and a strong cadre of columnists. Hürriyet has regional offices in Istanbul, Izmir, Adana and Trabzon, as well as a news network comprising 52 offices and 600 reporters in Turkey and abroad, all affiliated with Doğan News Agency, which serves newspapers and television channels that are under the management of Doğan Media Group. Hürriyet is printed in Frankfurt, Germany; as of January 2017, according to Alexa, its website was the tenth most visited in Turkey, the second most visited of a newspaper and the fourth most visited news website. On 21 March 2018, Doğan Yayın Holding, the parent company of Hürriyet, was sold to Demirören Holding for $1.2 billion. The Demirören Group is known for its pro-government stance.
Hürriyet was founded by Sedat Simavi on 1 May 1948 with a staff of 48. Selling 50,000 in its first week, Hürriyet was Simavi's 59th and last publication, it is considered a high-circulation newspaper in Turkey. In February 2009, the newspaper received an 826.2 million TL fine for tax evasion by Doğan Group/Petrol Ofisi. Following this, the Istanbul Stock Exchange suspended Doğan Holding's shares, Fitch downgraded Hürriyet to'BB-'. Executives at the Doğan Group expressed the opinion that the tax fine was politically motivated "intimidation", caused by Hürriyet's linking of Prime Minister Recep Tayyip Erdoğan and his political party, AKP, to a charity scandal in Germany. In March 2009, Jose Manuel Barroso, president of the European Commission, expressed public concern about the fine, saying that it threatened "pluralism and freedom of the press."In September 2009, Doğan Group was fined a record US$2.5 billion, related to alleged past tax irregularities. The September fine caused further expressions of public concern from the European Commission, as well as the Organization for Security and Co-operation in Europe.
It caused some critics and global investors to compare the fines to then-Russian President Vladimir Putin's use of tax-evasion charges to bankrupt oil company Yukos for political reasons. In an interview, Erdoğan denied this charge, calling it "very ugly" and "disrespectful" to both himself and Putin. Official website Hürriyet USA Hürriyet Corporate Hürriyet news
TÜBİTAK National Observatory
TÜBİTAK National Observatory is a ground-based astronomical observatory operated by the TUG Institute of the Scientific and Technological Research Council of Turkey. Established in 1991, it is located at an altitude of 2,450 m in Bakırtepe, around 50 km west-southwest of Antalya in southern Turkey. There are five telescopes installed in Bakırtepe: RTT150 - Russian-Turkish 1.5-m Telescope T100 - 1.0 m Ritchey–Chrétien telescope T60 - 0.6 m Ritchey–Chrétien telescope YT40 - 0.4 m Schmidt–Cassegrain telescope ROTSEIIID Robotic Optical Transient Search Experiment Scientists led by a Turkish astronomer from Ankara University discovered an exoplanet orbiting the giant star HD 208897, located at a distance of some 210 light years from the Earth. The exoplanet has a minimum mass of 1.4 Jupiter masses, rotates its parent star from about 1.05 AU away in every 353 days on a nearly circular orbit. The discovery is the result of a ten-year-long research work of precise radial-velocity method carried out by using the Coude Echelle Spectrograph installed on the 1.5-meter Russian-Turkish Telescope.
Follow-up observations at the Okayama Astrophysical Observatory in Japan and the Ankara University Kreiken Observatory confirmed the discovery, made public on August 6, 2017
Middle East Technical University
Middle East Technical University is a public technical university located in Ankara, Turkey. The university puts special emphasis on research and education in engineering and natural sciences, offering about 40 undergraduate programs within 5 faculties, 97 masters and 62 doctorate programs within 5 graduate schools; the main campus of METU spans an area of 11,100 acres, comprising, in addition to academic and auxiliary facilities, a forest area of 7,500 acres, the natural lake Eymir. METU has more than 120,000 alumni worldwide; the official language of instruction at METU is English. Over one third of the 1,000 highest scoring students in the national university entrance examination choose to enroll in METU. METU had the greatest share in national research funding by the Scientific and Technological Research Council of Turkey in the last five years, it is the leading university in Turkey in terms of the number of European Union Framework Programme projects participation. Over 40% of METU's undergraduate alumni choose to pursue graduate studies.
Middle East Technical University was founded under the name "Orta Doğu Teknoloji Enstitüsü" on November 15, 1956, to contribute to the development of Turkey and the surrounding countries of the Middle East and Caucasus, by creating a skilled workforce in the natural and social sciences. "Arrangements and Procedures as for the Foundation of METU, Law No 6213" was enacted on January 22, 1957, whereby the current name "Orta Doğu Teknik Üniversitesi" was adopted. The "Foundation Act No 7907", setting forth the particular standing of METU and establishing it as a juridical entity, was enacted on May 27, 1959. In the early years following its foundation, METU was temporarily hosted in a small building that belonged to the Social Security Office of Retirees in Kızılay and another building near the Grand National Assembly of Turkey. In 1963, the university moved to its current location west of Ankara city center, creating the first university campus of Turkey. In 1956, the Department of Architecture initiated the first academic program at METU, followed by the Department of Mechanical Engineering in the spring of 1957.
At the start of the 1957–1958 academic year, the Faculty of Architecture, the Faculty of Engineering, the Faculty of Administrative Sciences were established. In 1959, the establishment of the Faculty of Arts and Sciences was completed; the Faculty of Education launched its academic program in 1982. METU has 42 academic departments; these are responsible for the undergraduate programs. Faculty of Architecture: Architecture and Regional Planning, Industrial Design Faculty of Arts and Sciences: Biology, History, Molecular Biology and Genetics, Physics, Sociology, Statistics Faculty of Economic and Administrative Sciences: Business Administration, International Relations, Political Science and Public Administration Faculty of Education: Computer Education and Instructional Technology, Educational Sciences, Elementary Education, Foreign Language Education, Physical Education and Sports, Secondary Science and Mathematics Education Faculty of Engineering: Aerospace Engineering, Chemical Engineering, Civil Engineering, Computer Engineering and Electronics Engineering, Engineering Sciences, Environmental Engineering, Food Engineering, Geological Engineering, Industrial Engineering, Mechanical Engineering and Materials Engineering, Mining Engineering and Natural Gas Engineering In addition to these, there are the Department of Basic English and the Department of Modern Languages in the School of Foreign Languages.
The 5 graduate schools present in METU are responsible for the graduate programs. Graduate School of Applied Mathematics Graduate School of Informatics Graduate School of Marine Sciences Graduate School of Natural and Applied Sciences Graduate School of Social Sciences As of 2010, METU has 23,000 students, of which 15,800 are enrolled in undergraduate programs, 4,500 in masters, 2,700 in doctorate programs. A further 1,500 students are attending programs in the new Northern Cyprus Campus. Over 40% of METU's students go on to graduate school; each academic year, METU hosts over 1,500 regular international students from nearly 80 different countries. As of 2010, the university employs 2,500 faculty, 500 academic instructors, over 2,000 research assistants; the number of the alumni exceeds 500,000. METU has about 40 undergraduate programs within the faculties of Engineering, Architecture and Sciences, Economic and Administrative Sciences, Education, there are 97 masters and 62 doctorate programs available in the graduate schools of Natural and Applied Sciences, Social Sciences, Applied Mathematics, Marine Sciences.
METU ranks close to the top among research universities in Turkey, with over one third of the 1,000 highest scoring students in the nati
TÜBİTAK Defense Industries Research and Development Institute
TÜBİTAK Defense Industries Research and Development Institute, shortly TÜBİTAK SAGE, is a Turkish institution carrying out research and development projects on defense industry technology. It was established in 1972 at Beşevler neighborhood in central Ankara under the name "Guided Vehicles Technology and Measurement Center" by the Scientific and Technological Research Council of Turkey. In 1983, the institution was renamed to "Ballistics Research Institute", in 1988 it took its current name; the organization conducts research and development activities to meet the needs of the Turkish Armed Forces and national defense industry. SAGE moved in 1993 to its new location in Lalahan village of Elmadağ district, 30 km northeast of Ankara; the facility in Beşevler serves as Ankara Wind Tunnel. The institute runs a site within the Middle East Technical University. SOM cruise missileThe Stand-off Missile is a high-precision long-range cruise missile, which can be launched from land and air platforms. Certification efforts are in progress to enable the SOM missile for integration with both Turkish Air Force F-35 Lightning II and NATO allied F-35.
HGK guidance kit The HGK guidance kit is a GPS/INS guidance kit with flap out wings that converts 2000-lb Mark 84 bombs into smart weapons. It enables precision strike talent in all weather conditions with long range at a deviation of 6 m. KGK smart wing adapter kit The KGK guidance kit a precision guidance wing kit that converts 1000-lb Mark 83 bombs and 500-lb Mark 82 bombs into long range fire-and-forget smart weapons. TOROS artillery rocket systemThe TOROS artillery rocket system is an artillery rocket system consisting of both 230 and 260 mm caliber rockets fired from a launcher vehicle. Thermal batteryNEB bunker buster The NEB Bunker Buster is a bomb able to destroy the reinforced concrete fixed and buried targets by penetrating to them with desired time delay, it is compatible with HGK and GBU-10 Paveway II
A semiconductor material has an electrical conductivity value falling between that of a metal, like copper, etc. and an insulator, such as glass. Their resistance decreases as their temperature increases, behaviour opposite to that of a metal, their conducting properties may be altered in useful ways by the deliberate, controlled introduction of impurities into the crystal structure. Where two differently-doped regions exist in the same crystal, a semiconductor junction is created; the behavior of charge carriers which include electrons and electron holes at these junctions is the basis of diodes and all modern electronics. Some examples of semiconductors are silicon and gallium arsenide. After silicon, gallium arsenide is the second most common semiconductor used in laser diodes, solar cells, microwave frequency integrated circuits, others. Silicon is a critical element for fabricating most electronic circuits. Semiconductor devices can display a range of useful properties such as passing current more in one direction than the other, showing variable resistance, sensitivity to light or heat.
Because the electrical properties of a semiconductor material can be modified by doping, or by the application of electrical fields or light, devices made from semiconductors can be used for amplification and energy conversion. The conductivity of silicon is increased by adding a small amount of trivalent atoms; this process is known as doping and resulting semiconductors are known as doped or extrinsic semiconductors. Apart from doping, the conductivity of a semiconductor can be improved by increasing its temperature; this is contrary to the behaviour of a metal in which conductivity decreases with increase in temperature. The modern understanding of the properties of a semiconductor relies on quantum physics to explain the movement of charge carriers in a crystal lattice. Doping increases the number of charge carriers within the crystal; when a doped semiconductor contains free holes it is called "p-type", when it contains free electrons it is known as "n-type". The semiconductor materials used in electronic devices are doped under precise conditions to control the concentration and regions of p- and n-type dopants.
A single semiconductor crystal can have many p- and n-type regions. Although some pure elements and many compounds display semiconductor properties, silicon and compounds of gallium are the most used in electronic devices. Elements near the so-called "metalloid staircase", where the metalloids are located on the periodic table, are used as semiconductors; some of the properties of semiconductor materials were observed throughout the mid 19th and first decades of the 20th century. The first practical application of semiconductors in electronics was the 1904 development of the cat's-whisker detector, a primitive semiconductor diode used in early radio receivers. Developments in quantum physics in turn allowed the development of the transistor in 1947 and the integrated circuit in 1958. Variable electrical conductivity Semiconductors in their natural state are poor conductors because a current requires the flow of electrons, semiconductors have their valence bands filled, preventing the entry flow of new electrons.
There are several developed techniques that allow semiconducting materials to behave like conducting materials, such as doping or gating. These modifications have two outcomes: p-type; these refer to the shortage of electrons, respectively. An unbalanced number of electrons would cause a current to flow through the material. Heterojunctions Heterojunctions occur when two differently doped semiconducting materials are joined together. For example, a configuration could consist of n-doped germanium; this results in an exchange of electrons and holes between the differently doped semiconducting materials. The n-doped germanium would have an excess of electrons, the p-doped germanium would have an excess of holes; the transfer occurs until equilibrium is reached by a process called recombination, which causes the migrating electrons from the n-type to come in contact with the migrating holes from the p-type. A product of this process is charged ions. Excited electrons A difference in electric potential on a semiconducting material would cause it to leave thermal equilibrium and create a non-equilibrium situation.
This introduces electrons and holes to the system, which interact via a process called ambipolar diffusion. Whenever thermal equilibrium is disturbed in a semiconducting material, the number of holes and electrons changes; such disruptions can occur as a result of a temperature difference or photons, which can enter the system and create electrons and holes. The process that creates and annihilates electrons and holes are called generation and recombination. Light emission In certain semiconductors, excited electrons can relax by emitting light instead of producing heat; these semiconductors are used in the construction of light-emitting diodes and fluorescent quantum dots. High thermal conductivitySemiconductors with high thermal conductivity can be used for heat dissipation and improving thermal management of electronics. Thermal energy conversion Semiconductors have large thermoelectric power factors making them useful in thermoelectric generators, as well as high thermoelectric figures of merit making them useful in thermoelectric coolers.
A large number of elements and compounds have semiconducting properties, including: Certain pure elements are found in Group 14 of the p
Electromagnetic compatibility is the branch of electrical engineering concerned with the unintentional generation and reception of electromagnetic energy which may cause unwanted effects such as electromagnetic interference or physical damage in operational equipment. It is the ability of an equipment or system to function satisfactorily in its electromagnetic environment without introducing intolerable electromagnetic disturbances to anything in that environment; the goal of EMC is the correct operation of different equipment in a common electromagnetic environment. EMC pursues three main classes of issue. Emission is the generation of electromagnetic energy, whether deliberate or accidental, by some source and its release into the environment. EMC studies the unwanted emissions and the countermeasures which may be taken in order to reduce unwanted emissions; the second class, susceptibility, is the tendency of electrical equipment, referred to as the victim, to malfunction or break down in the presence of unwanted emissions, which are known as Radio frequency interference.
Immunity is the opposite of susceptibility, being the ability of equipment to function in the presence of RFI, with the discipline of "hardening" equipment being known as susceptibility or immunity. A third class studied is coupling, the mechanism by which emitted interference reaches the victim. Interference mitigation and hence electromagnetic compatibility may be achieved by addressing any or all of these issues, i.e. quieting the sources of interference, inhibiting coupling paths and/or hardening the potential victims. In practice, many of the engineering techniques used, such as grounding and shielding, apply to all three issues. While electromagnetic interference is a phenomenon - the radiation emitted and its effects - electromagnetic compatibility is an equipment characteristic or property - not to behave unacceptably in the EMI environment. EMC ensures the correct operation, in the same electromagnetic environment, of different equipment items which use or respond to electromagnetic phenomena, the avoidance of any interference effects.
Another way of saying this is. Besides understanding the phenomena in themselves, EMC addresses the countermeasures, such as control regimes and measurement, which should be taken in order to prevent emissions from causing any adverse effect. Electromagnetic interference divides into several categories according to the source and signal characteristics; the origin of interference called "noise" in this context, can be man-made or natural. Continuous, or continuous wave, interference arises where the source continuously emits at a given range of frequencies; this type is divided into sub-categories according to frequency range, as a whole is sometimes referred to as "DC to daylight". Audio frequency, from low frequencies up to around 20 kHz. Frequencies up to 100 kHz may sometimes be classified as audio. Sources include: Mains hum from: power supply units, nearby power supply wiring, transmission lines and substations. Audio processing equipment, such as audio power amplifiers and loudspeakers. Demodulation of a high-frequency carrier wave such as an FM radio transmission.
Radio frequency interference, from 20 kHz to an upper limit which increases as technology pushes it higher. Sources include: Wireless and radio frequency transmissions Television and radio receivers Industrial and medical equipment Digital processing circuitry such as microcontrollers Broadband noise may be spread across parts of either or both frequency ranges, with no particular frequency accentuated. Sources include: Solar activity Continuously operating spark gaps such as arc welders CDMA mobile telephony An electromagnetic pulse, sometimes called a transient disturbance, arises where the source emits a short-duration pulse of energy; the energy is broadband by nature, although it excites a narrow-band damped sine wave response in the victim. Sources divide broadly into repetitive events. Sources of isolated EMP events include: Switching action of electrical circuitry, including inductive loads such as relays, solenoids, or electric motors. Electrostatic discharge, as a result of two charged objects coming into close contact.
Lightning electromagnetic pulse, although a short series of pulses. Geomagnetic storm, causing a geomagnetically induced current. Nuclear electromagnetic pulse from a high-altitude nuclear explosion, designed to create the pulse as its primary destructive effect. Non-nuclear electromagnetic pulse weapons. Power line surges/pulses Sources of repetitive EMP events, sometimes as regular pulse trains, include: Electric motors Electrical ignition systems, such as in gasoline engines. Continual switching actions of digital electronic circuitry; some of the technical words which are employed can be used with differing meanings. These terms are used here in a accepted way, consistent with other articles in the encyclopedia; the basic arrangement of noise source, coupling path and victim, receptor or sink is shown in the figure below. Source and victim are electronic hardware devices, though the source may be a natural phenomenon such as a lightning strike, electrostatic discharge or, in one famous case, the Big Bang at the origin of the Universe.
There are four basic coupling mechanisms: conductive, magnetic or inductive, radiative. Any coupling path can be broken down into one or more of these coupling mechanisms working together. For example the lower path in the dia