Embedded system

An embedded system is a computer system—a combination of a computer processor, computer memory, input/output peripheral devices—that has a dedicated function within a larger mechanical or electrical system. It is embedded as part of a complete device including electrical or electronic hardware and mechanical parts; because an embedded system controls physical operations of the machine that it is embedded within, it has real-time computing constraints. Embedded systems control many devices in common use today. Ninety-eight percent of all microprocessors manufactured are used in embedded systems. Modern embedded systems are based on microcontrollers, but ordinary microprocessors are common in more complex systems. In either case, the processor used may be types ranging from general purpose to those specialized in a certain class of computations, or custom designed for the application at hand. A common standard class of dedicated processors is the digital signal processor. Since the embedded system is dedicated to specific tasks, design engineers can optimize it to reduce the size and cost of the product and increase the reliability and performance.

Some embedded systems are mass-produced. Embedded systems range from portable devices such as digital watches and MP3 players, to large stationary installations like traffic light controllers, programmable logic controllers, large complex systems like hybrid vehicles, medical imaging systems, avionics. Complexity varies from low, with a single microcontroller chip, to high with multiple units and networks mounted inside a large equipment rack; the origins of the microprocessor and the microcontroller can be traced back to the MOS integrated circuit, an integrated circuit chip fabricated from MOSFETs and was developed in the early 1960s. By 1964, MOS chips had reached higher transistor density and lower manufacturing costs than bipolar chips. MOS chips further increased in complexity at a rate predicted by Moore's law, leading to large-scale integration with hundreds of transistors on a single MOS chip by the late 1960s; the application of MOS LSI chips to computing was the basis for the first microprocessors, as engineers began recognizing that a complete computer processor system could be contained on several MOS LSI chips.

The first multi-chip microprocessors, the Four-Phase Systems AL1 in 1969 and the Garrett AiResearch MP944 in 1970, were developed with multiple MOS LSI chips. The first single-chip microprocessor was the Intel 4004, released in 1971, it was developed by Federico Faggin, using his silicon-gate MOS technology, along with Intel engineers Marcian Hoff and Stan Mazor, Busicom engineer Masatoshi Shima. One of the first recognizably modern embedded systems was the Apollo Guidance Computer, developed ca. 1965 by Charles Stark Draper at the MIT Instrumentation Laboratory. At the project's inception, the Apollo guidance computer was considered the riskiest item in the Apollo project as it employed the newly developed monolithic integrated circuits to reduce the size and weight. An early mass-produced embedded system was the Autonetics D-17 guidance computer for the Minuteman missile, released in 1961; when the Minuteman II went into production in 1966, the D-17 was replaced with a new computer, the first high-volume use of integrated circuits.

Since these early applications in the 1960s, embedded systems have come down in price and there has been a dramatic rise in processing power and functionality. An early microprocessor for example, the Intel 4004, was designed for calculators and other small systems but still required external memory and support chips. In 1978 National Engineering Manufacturers Association released a "standard" for programmable microcontrollers, including any computer-based controllers, such as single board computers and event-based controllers; as the cost of microprocessors and microcontrollers fell it became feasible to replace expensive knob-based analog components such as potentiometers and variable capacitors with up/down buttons or knobs read out by a microprocessor in consumer products. By the early 1980s, memory and output system components had been integrated into the same chip as the processor forming a microcontroller. Microcontrollers find applications. A comparatively low-cost microcontroller may be programmed to fulfill the same role as a large number of separate components.

Although in this context an embedded system is more complex than a traditional solution, most of the complexity is contained within the microcontroller itself. Few additional components may be needed and most of the design effort is in the software. Software prototype and test can be quicker compared with the design and construction of a new circuit not using an embedded processor. Embedded systems are found in consumer, automotive, home appliances, medical and military applications. Telecommunications systems employ numerous embedded systems from telephone switches for the network to cell phones at the end user. Computer networking uses dedicated routers and network bridges to route data. Consumer electronics include MP3 players, mobile phones, video game consoles, digital cameras, GPS receivers, printers. Household appliances, such as microwave ovens, washing machines and dishwashers, include embedded systems to provide flexibility and features. Advanced HVAC systems use networked thermostats to more and

2008 Kazan gas explosion

The Kazan gas explosion occurred on January 9, 2008, destroying an entire corner of a three-story khrushchyovka-style apartment building on Malaya Pechyorskaya Street in the Aviastroitelny District of Kazan, Russia. The explosion took place at 0:28 a.m. local time. The blast destroyed 12 apartments and killed ten residents, including one woman who died of blast-related trauma in a hospital after being rescued from the rubble. Additionally, two were non-fatally wounded. Rescue efforts were complicated by low temperatures of -30 °C, raising concerns that victims trapped in the destroyed building might freeze before being reached by rescuers. Three of the building residents, including one child, were not accounted for. However, several body parts were found in the ruins, subsequent DNA analyses determined that the young girl and her grandfather were both among those killed in the explosion; the girl's grandmother thought to have been in the apartment, is still counted missing. The exact cause of the blast has not been established.

While a criminal investigation was initiated, city authorities suspect that the cause may have been improper use of gas appliances. The Kazan city government arranged for residents of the building destroyed in the blast to receive apartments in newly constructed buildings. On July 10, 2008, the first nine affected families received keys to new apartments in a building on Amirkhan Street; the residents received the apartments in exchange for their destroyed ones, an arrangement set up by the city-held OAO Residential Investment Company of the City of Kazan and supported by Kazan mayor Ilsur Metshin and the district administration. Families were given the opportunity to pay for larger apartments at a discounted price per square meter

Daniel Toribio

Daniel Toribio Gutiérrez is a Spanish professional footballer who plays for Racing de Santander on loan from AD Alcorcón as a midfielder. Born in Girona, Toribio was a product of FC Barcelona's youth academy, he joined Atlético Malagueño in 2009, from where he was promoted to Málaga CF's first team midway through the season, his La Liga debut coming on 7 November 2009 in a 2–2 away draw against CD Tenerife. On 17 August 2010, Toribio and Javi López joined SD Ponferradina of the Segunda División on loan for the campaign. On 6 July 2011, he terminated his two-year contract with Málaga and signed for another team in that level, Villarreal CF B. Toribio continued to compete in the second tier in the following years, representing Real Murcia, Deportivo Alavés, AD Alcorcón and Racing de Santander. Daniel Toribio at BDFutbol Daniel Toribio at Futbolme Daniel Toribio at La Preferente Daniel Toribio at Soccerway