San Antonio the City of San Antonio, is the seventh-most populous city in the United States, the second-most populous city in both Texas and the Southern United States, with more than 1.5 million residents. Founded as a Spanish mission and colonial outpost in 1718, the city became the first chartered civil settlement in present-day Texas in 1731; the area was still part of the Spanish Empire, of the Mexican Republic. Today it is the state's oldest municipality; the city's deep history is contrasted with its rapid recent growth during the past few decades. It was the fastest-growing of the top ten largest cities in the United States from 2000 to 2010, the second from 1990 to 2000. Straddling the regional divide between South and Central Texas, San Antonio anchors the southwestern corner of an urban megaregion colloquially known as the "Texas Triangle". San Antonio serves as the seat of Bexar County. Since San Antonio was founded during the Spanish Colonial Era, it has a church in its center, on the main civic plaza in front, a characteristic of many Spanish-founded cities and villages in Spain and Latin America.
As with many other urban centers in the Southwestern United States, areas outside the city limits are sparsely populated. San Antonio is the center of the San Antonio–New Braunfels metropolitan statistical area. Called Greater San Antonio, the metro area has a population of 2,473,974 based on the 2017 U. S. census estimate, making it the 24th-largest metropolitan area in the United States and third-largest in Texas. Growth along the Interstate 35 and Interstate 10 corridors to the north and east make it that the metropolitan area will continue to expand. San Antonio was named by a 1691 Spanish expedition for Saint Anthony of Padua, whose feast day is June 13; the city contains five 18th-century Spanish frontier missions, including The Alamo and San Antonio Missions National Historical Park, which together were designated UNESCO World Heritage sites in 2015. Other notable attractions include the River Walk, the Tower of the Americas, SeaWorld, the Alamo Bowl, Marriage Island. Commercial entertainment includes Morgan's Wonderland amusement parks.
According to the San Antonio Convention and Visitors Bureau, the city is visited by about 32 million tourists a year. It is home to the five-time NBA champion San Antonio Spurs, hosts the annual San Antonio Stock Show & Rodeo, one of the largest such events in the U. S; the U. S. Armed Forces have numerous facilities around San Antonio. Lackland Air Force Base, Randolph Air Force Base, Lackland AFB/Kelly Field Annex, Camp Bullis, Camp Stanley are outside the city limits. Kelly Air Force Base operated out of San Antonio until 2001, when the airfield was transferred to Lackland AFB; the remaining parts of the base were developed as Port San Antonio, an industrial/business park and aerospace complex. San Antonio is home to six Fortune 500 companies and the South Texas Medical Center, the only medical research and care provider in the South Texas region. At the time of European encounter, Payaya Indians lived near the San Antonio River Valley in the San Pedro Springs area, they called the vicinity Yanaguana, meaning "refreshing waters".
In 1691, a group of Spanish explorers and missionaries came upon the river and Payaya settlement on June 13, the feast day of St. Anthony of Padua, they named the river "San Antonio" in his honor. It was years. Father Antonio de Olivares visited the site in 1709, he was determined to found a mission and civilian settlement there; the viceroy gave formal approval for a combined mission and presidio in late 1716, as he wanted to forestall any French expansion into the area from their colony of La Louisiane to the east, as well as prevent illegal trading with the Payaya. He directed the governor of Coahuila y Tejas, to establish the mission complex. Differences between Alarcón and Olivares resulted in delays, construction did not start until 1718. Olivares built, with the help of the Payaya Indians, the Misión de San Antonio de Valero, the Presidio San Antonio de Bexar, the bridge that connected both, the Acequia Madre de Valero; the families who clustered around the presidio and mission were the start of Villa de Béjar, destined to become the most important town in Spanish Texas.
On May 1, the governor transferred ownership of the Mission San Antonio de Valero to Fray Antonio de Olivares. On May 5, 1718 he commissioned the Presidio San Antonio de Béxar on the west side of the San Antonio River, one-fourth league from the mission. On February 14, 1719, the Marquis of San Miguel de Aguayo proposed to the king of Spain that 400 families be transported from the Canary Islands, Galicia, or Havana to populate the province of Texas, his plan was approved, notice was given the Canary Islanders to furnish 200 families. By June 1730, 25 families had reached Cuba, 10 families had been sent to Veracruz before orders from Spain came to stop the re-settlement. Under the leadership of Juan Leal Goraz, the group marched overland from Veracruz to the Presidio San Antonio de Béxar, where they arrived on March 9, 1731. Due to marriages along the way, the party now included a total of 56 persons, they joined the military community established in 1718. The immigrants f
Digital image processing
In computer science, digital image processing is the use of computer algorithms to perform image processing on digital images. As a subcategory or field of digital signal processing, digital image processing has many advantages over analog image processing, it allows a much wider range of algorithms to be applied to the input data and can avoid problems such as the build-up of noise and signal distortion during processing. Since images are defined over two dimensions digital image processing may be modeled in the form of multidimensional systems. Many of the techniques of digital image processing, or digital picture processing as it was called, were developed in the 1960s at the Jet Propulsion Laboratory, Massachusetts Institute of Technology, Bell Laboratories, University of Maryland, a few other research facilities, with application to satellite imagery, wire-photo standards conversion, medical imaging, character recognition, photograph enhancement; the cost of processing was high, with the computing equipment of that era.
That changed in the 1970s, when digital image processing proliferated as cheaper computers and dedicated hardware became available. Images could be processed in real time, for some dedicated problems such as television standards conversion; as general-purpose computers became faster, they started to take over the role of dedicated hardware for all but the most specialized and computer-intensive operations. With the fast computers and signal processors available in the 2000s, digital image processing has become the most common form of image processing and is used because it is not only the most versatile method, but the cheapest. Digital image processing technology for medical applications was inducted into the Space Foundation Space Technology Hall of Fame in 1994. Digital image processing allows the use of much more complex algorithms, hence, can offer both more sophisticated performance at simple tasks, the implementation of methods which would be impossible by analog means. In particular, digital image processing is the only practical technology for: Classification Feature extraction Multi-scale signal analysis Pattern recognition ProjectionSome techniques which are used in digital image processing include: Anisotropic diffusion Hidden Markov models Image editing Image restoration Independent component analysis Linear filtering Neural networks Partial differential equations Pixelation Principal components analysis Self-organizing maps Wavelets Digital filters are used to blur and sharpen digital images.
Filtering can be performed in the spatial domain by convolution with designed kernels, or in the frequency domain by masking specific frequency regions. The following examples show both methods: Images are padded before being transformed to the Fourier space, the highpass filtered images below illustrate the consequences of different padding techniques: Notice that the highpass filter shows extra edges when zero padded compared to the repeated edge padding. MATLAB example for spatial domain highpass filtering. Affine transformations enable basic image transformations including scale, translate and shear as is shown in the following examples: To apply the affine matrix to an image, the image is converted to matrix in which each entry corresponds to the pixel intensity at that location; each pixel's location can be represented as a vector indicating the coordinates of that pixel in the image, where x and y are the row and column of a pixel in the image matrix. This allows the coordinate to be multiplied by an affine-transformation matrix, which gives the position that the pixel value will be copied to in the output image.
However, to allow transformations that require translation transformations, 3 dimensional homogeneous coordinates are needed. The third dimension is set to a non-zero constant 1, so that the new coordinate is; this allows the coordinate vector to be multiplied by a 3 by 3 matrix. So the third dimension, the constant 1, allows translation; because matrix multiplication is associative, multiple affine transformations can be combined into a single affine transformation by multiplying the matrix of each individual transformation in the order that the transformations are done. This results in a single matrix that, when applied to a point vector, gives the same result as all the individual transformations performed on the vector in sequence, thus a sequence of affine transformation matrices can be reduced to a single affine transformation matrix. For example, 2 dimensional coordinates only allow rotation about the origin, but 3 dimensional homogeneous coordinates can be used to first translate any point to perform the rotation, lastly translate the origin back to the original point.
These 3 affine transformations can be combined into a single matrix, thus allowing rotation around any point in the image. Digital cameras include specialized digital image processing hardware – either dedicated chips or added circuitry on other chips – to convert the raw data from their image sensor into a color-corrected image in a standard image file format. Westworld was the first feature film to use the digital image processing to pixellate photography to simulate an android's point of view. Computer graphics Computer vision CVIPtools Digitizing Free boundary condition GPGPU Homomorphic filtering Image analysis IEEE Intelligent Transportation Systems Society Multidimensional systems Remote sensing software Standard test image Superresolution Solomon, C. J.. P.. Fundamentals of Digital Image Processing: A Practical Approach with Exa
The Alamodome is a 64,000-seat multi-purpose stadium in San Antonio, Texas. It is located on the southeastern fringe of downtown San Antonio; the facility opened on May 1993, having been constructed at a cost of $186 million. The multi-purpose facility was intended to increase the city's convention traffic and attract a professional football franchise, it placated the San Antonio Spurs' demands for a larger arena. The Spurs played in the Alamodome for a decade became disenchanted with the facility and convinced Bexar County to construct a new arena for them, now called the AT&T Center; the Alamodome's regular tenants are the UTSA Roadrunners and the San Antonio Commanders of the Alliance of American Football. The facility is a rectilinear 5-level stadium which can seat up to 64,000 spectators for a typical football game and is expandable to hold 72,000 spectators; the stadium was designed to convert into a basketball or hockey arena. Converting the stadium for basketball and hockey takes 12–18 hours to set up retractable seating and installing the playing surface.
In this configuration only the two lower levels at one or both ends are used. The arena configuration seats 20,662 spectators, but is expandable to 39,500 when the upper level is opened; the stadium can be adapted into a smaller auditorium space, with an intimate, enclosed setting, seating upwards of 11,000 using floor space and the north grandstand. The Alamodome opened with 6,000 club level seats; the original design specifications called for 66 luxury suites. However, since the Spurs were the only full-time tenant at the time, only 38 luxury suites in the north end of the facility were built; the footprints for the 28 unbuilt luxury suites were open floor space just behind the club level seats that surround the south end of the facility. In 2006, the Alamodome underwent an expansion to accommodate 14 new luxury suites; the Sports Club and the Top of the Dome restaurant received renovations in 2004. The Alamodome has two permanent Olympic-size ice rinks that can be used for NHL games, figure skating and speed skating.
The facility contains 30,000 square feet of meeting rooms and 160,000 square feet of continuous exhibit space. The Alamodome is the home of the University of Texas at San Antonio Roadrunners and the San Antonio Commanders of the Alliance of American Football beginning in February 2019, it was home to the San Antonio Spurs of the NBA from 1993 to 2002, the San Antonio Texans of the CFL in 1995. The facility hosts special events such as the annual Alamo Bowl football game, UTSA's graduation ceremonies, as well as most of Northside ISD's high school graduation ceremonies. UIL State Football Playoff games are held in the Alamodome, including State Quarterfinals/Region 4 Finals and championship games in 2006, 2007 and 2009 The Alamodome's ability to accommodate basketball made it attractive to then-Spurs owner Red McCombs, looking for some time for a larger arena to replace their longtime home, HemisFair Arena; the Spurs moved to the Alamodome after the 1992–93 NBA season. They played nine seasons in the Alamodome from 1993 to 2002, including their first NBA championship season, played against the New York Knicks in 1999.
During the regular season, most of the upper level was curtained off. However, on certain weekends and when popular opponents came to town, the Spurs expanded the Alamodome's capacity to 35,000 by opening three portions of the upper level. More sections of the upper level were opened for the playoffs, expanding capacity to 39,500. Attendance was 39,514 for Game 1 of the 1999 NBA Finals and 39,554 for Game 2. Though the late 1990s saw the Spurs soar in popularity, the decision was made to move the team out of the spacious stadium and build a new arena. While the Alamodome had been designed to accommodate basketball, it was a football stadium; as the years passed, Spurs management and fans grew dissatisfied with its poor sight lines and cavernous feel. Part of the problem was the manner; the basketball court was at one end of the venue with temporary stands on one side of the court, leaving over half of the stadium curtained off. Television broadcast trucks were set up on the unused half of the playing surface.
By comparison, more modern domed stadiums that can accommodate basketball, such as AT&T Stadium in Arlington, place the basketball court in the center of where the football field would be, allowing for much larger attendances. Additionally, the Spurs tied up the Alamodome for most of the winter and spring due to their deep playoff runs. With the Alamodome booked solid well into April, it was difficult to accommodate conventions, concerts or a prospective football team. Moving the Spurs out of the Alamodome opened up more contiguous dates allowing the facility to schedule more events, though it has yet to host a Super Bowl; the Spurs moved to the new SBC Center after the 2001–02 season. The 1996 NBA All-Star Game was played in the Alamodome; the Alamodome is the site of the annual Alamo Bowl, which matches the second-choice teams from the Pac-12 Conference and the Big 12 Conference. The 2006 Alamo Bowl between the Texas Longhorns and the Iowa Hawkeyes was attended by 65,875, which set a facility-record crowd for a sporting event, only to have that record broken by an Alamo Bowl event the next year between Texas A&M and Penn State, which drew 66,166 attendees.
September 16, 2006, marked the fir
Mechanical engineering is the discipline that applies engineering, engineering mathematics, materials science principles to design, analyze and maintain mechanical systems. It is one of the broadest of the engineering disciplines; the mechanical engineering field requires an understanding of core areas including mechanics, thermodynamics, materials science, structural analysis, electricity. In addition to these core principles, mechanical engineers use tools such as computer-aided design, computer-aided manufacturing, product life cycle management to design and analyze manufacturing plants, industrial equipment and machinery and cooling systems, transport systems, watercraft, medical devices and others, it is the branch of engineering that involves the design and operation of machinery. Mechanical engineering emerged as a field during the Industrial Revolution in Europe in the 18th century. In the 19th century, developments in physics led to the development of mechanical engineering science.
The field has continually evolved to incorporate advancements. It overlaps with aerospace engineering, metallurgical engineering, civil engineering, electrical engineering, manufacturing engineering, chemical engineering, industrial engineering, other engineering disciplines to varying amounts. Mechanical engineers may work in the field of biomedical engineering with biomechanics, transport phenomena, bionanotechnology, modelling of biological systems; the application of mechanical engineering can be seen in the archives of various ancient and medieval societies. In ancient Greece, the works of Archimedes influenced mechanics in the Western tradition and Heron of Alexandria created the first steam engine. In China, Zhang Heng improved a water clock and invented a seismometer, Ma Jun invented a chariot with differential gears; the medieval Chinese horologist and engineer Su Song incorporated an escapement mechanism into his astronomical clock tower two centuries before escapement devices were found in medieval European clocks.
He invented the world's first known endless power-transmitting chain drive. During the Islamic Golden Age, Muslim inventors made remarkable contributions in the field of mechanical technology. Al-Jazari, one of them, wrote his famous Book of Knowledge of Ingenious Mechanical Devices in 1206 and presented many mechanical designs. Al-Jazari is the first known person to create devices such as the crankshaft and camshaft, which now form the basics of many mechanisms. During the 17th century, important breakthroughs in the foundations of mechanical engineering occurred in England. Sir Isaac Newton formulated Newton's Laws of Motion and developed Calculus, the mathematical basis of physics. Newton was reluctant to publish his works for years, but he was persuaded to do so by his colleagues, such as Sir Edmond Halley, much to the benefit of all mankind. Gottfried Wilhelm Leibniz is credited with creating Calculus during this time period. During the early 19th century industrial revolution, machine tools were developed in England and Scotland.
This allowed mechanical engineering to develop as a separate field within engineering. They brought with them manufacturing machines and the engines to power them; the first British professional society of mechanical engineers was formed in 1847 Institution of Mechanical Engineers, thirty years after the civil engineers formed the first such professional society Institution of Civil Engineers. On the European continent, Johann von Zimmermann founded the first factory for grinding machines in Chemnitz, Germany in 1848. In the United States, the American Society of Mechanical Engineers was formed in 1880, becoming the third such professional engineering society, after the American Society of Civil Engineers and the American Institute of Mining Engineers; the first schools in the United States to offer an engineering education were the United States Military Academy in 1817, an institution now known as Norwich University in 1819, Rensselaer Polytechnic Institute in 1825. Education in mechanical engineering has been based on a strong foundation in mathematics and science.
Degrees in mechanical engineering are offered at various universities worldwide. Mechanical engineering programs take four to five years of study and result in a Bachelor of Engineering, Bachelor of Science, Bachelor of Science Engineering, Bachelor of Technology, Bachelor of Mechanical Engineering, or Bachelor of Applied Science degree, in or with emphasis in mechanical engineering. In Spain and most of South America, where neither B. Sc. nor B. Tech. Programs have been adopted, the formal name for the degree is "Mechanical Engineer", the course work is based on five or six years of training. In Italy the course work is based on five years of education, training, but in order to qualify as an Engineer one has to pass a state exam at the end of the course. In Greece, the coursework is based on a five-year curriculum and the requirement of a'Diploma' Thesis, which upon completion a'Diploma' is awarded rather than a B. Sc. In the United States, most undergraduate mechanical engineering programs are accredited by the Accreditation Board for Engineering and Technology to ensure similar course requirements and standards a
American Society for Engineering Education
The American Society for Engineering Education is a non-profit member association, founded in 1893, dedicated to promoting and improving engineering and engineering technology education. The purpose of ASEE is the advancement of education in all of its functions which pertain to engineering and allied branches of science and technology, including the processes of teaching and learning, research, extension services and public relations. A full reading of the history of ASEE can be found in a 1993 centennial article in the Journal of Engineering Education. Founded as the Society for the Promotion of Engineering Education in 1893, the society was created at a time of great growth in American higher education. In 1862, Congress passed the Morrill Land-Grant Act, which provided money for states to establish public institutions of higher education; these institutions focused on providing practical skills "for the benefit of Agriculture and the Mechanic Arts". As a result of available higher education, more Americans started entering the workforce with advanced training in applied fields of knowledge.
However, they lacked grounding in the science and engineering principles underlying this practical knowledge. After a generation of students had passed through these new public universities, professors of engineering began to question whether they should adopt a more rigorous approach to teaching the fundamentals of their field, they concluded that engineering curricula should stress fundamental scientific and mathematical principles, not hands-on apprenticeship experiences. To organize support for this approach to engineering education, SPEE was formed in the midst of the 1893 Chicago World’s Fair. Known as the World's Columbian Exposition, this event heralded the promise of science and engineering by introducing many Americans, for example, to the wonders of electricity. Emerging out of the Fair’s World Engineering Congress, SPEE members dedicated themselves to improving engineering education at the classroom level. Over its history, the society has put out several reports on the subject, such as the Mann Report, the Wickenden Study, the Grinter Report.
During World War II, the federal government started to place more emphasis on research, prompting SPEE to form the Engineering College Research Association, more concerned with research than SPEE had been. The ECRA spoke for most engineering researchers, sought federal funds, collected and published information on academic engineering research. After the war, the desire to integrate the less research-oriented SPEE with the ECRA resulted in the disbanding of SPEE and the formation of ASEE in 1946. ASEE was a volunteer-run organization through the 1950s. In 1961, ASEE established a staff headquarters in Washington, DC, undertook a more activist posture. However, through the 1960s, the Vietnam War and social unrest in general made the mood on many campuses anti-technology, anti-business, anti-establishment. In the 1960s and 1970s, ASEE presidents Merritt Williams and George Hawkins reorganized ASEE to better represent its members and return its focus to teaching; as a result of this new focus, ASEE began to administer several teaching-related government contracts, including NASA's summer faculty fellowships and the Defense Department's Civil Defense Summer Institutes and Fellowships.
ASEE administers over ten government contracts, including the prestigious National Science Foundation's Graduate Research Fellowship Program. Another result of the renewed emphasis on teaching was ASEE’s initiative for recruiting minorities and women into engineering. ASEE created the Black Engineering College Development program which used industry funding to upgrade engineering faculty in traditionally black colleges and to develop public information on these schools. ASEE received several grants in the 1970s to research the status of women and American Indians and develop programs to attract more of these students to enter engineering. Since ASEE has continued to release studies on the subject in its Journal of Engineering Education, has created divisions devoted to developing programs and research in this area. ASEE produces many publications on the topic of engineering education, including the general-interest Prism, a monthly magazine covering the pervasive role of engineering in the world, the journals Journal of Engineering Education and Advances in Engineering Education, peer-reviewed journals covering research in engineering education, Profiles of Engineering and Technology Colleges, providing data on engineering colleges and universities, the eGFI: Engineering, Go For It! magazine and associated website, designed to attract high school students and their parents and teachers to engineering.
The magazine reports about cutting-edge technology and other important trends in engineering education, including: New instructional methods Innovative curricula Lifelong learning Research opportunities and developments Education and research projects with government and industry K-12 outreach activities that encourage youth to pursue studies and careers in engineering. The Journal of Engineering Education is a peer-reviewed academic journal published quarterly in partnership with a global community of engineering education societies and associations; the journal is a founding member of the International Federation of Engineering Education Societies. Advances in Engineering Education covers engineering education practice the creative use of multimedia; this directory provides profiles of United States and Canadian schools offering undergraduate and graduate engineering, as well as engineering technology programs with the intent of preparing prospective students for their future
Civil engineering is a professional engineering discipline that deals with the design and maintenance of the physical and built environment, including public works such as roads, canals, airports, sewerage systems, structural components of buildings, railways. Civil engineering is traditionally broken into a number of sub-disciplines, it is considered the second-oldest engineering discipline after military engineering, it is defined to distinguish non-military engineering from military engineering. Civil engineering takes place in the public sector from municipal through to national governments, in the private sector from individual homeowners through to international companies. Civil engineering is the application of physical and scientific principles for solving the problems of society, its history is intricately linked to advances in the understanding of physics and mathematics throughout history; because civil engineering is a wide-ranging profession, including several specialized sub-disciplines, its history is linked to knowledge of structures, materials science, geology, hydrology, environment and other fields.
Throughout ancient and medieval history most architectural design and construction was carried out by artisans, such as stonemasons and carpenters, rising to the role of master builder. Knowledge was retained in guilds and supplanted by advances. Structures and infrastructure that existed were repetitive, increases in scale were incremental. One of the earliest examples of a scientific approach to physical and mathematical problems applicable to civil engineering is the work of Archimedes in the 3rd century BC, including Archimedes Principle, which underpins our understanding of buoyancy, practical solutions such as Archimedes' screw. Brahmagupta, an Indian mathematician, used arithmetic in the 7th century AD, based on Hindu-Arabic numerals, for excavation computations. Engineering has been an aspect of life since the beginnings of human existence; the earliest practice of civil engineering may have commenced between 4000 and 2000 BC in ancient Egypt, the Indus Valley Civilization, Mesopotamia when humans started to abandon a nomadic existence, creating a need for the construction of shelter.
During this time, transportation became important leading to the development of the wheel and sailing. Until modern times there was no clear distinction between civil engineering and architecture, the term engineer and architect were geographical variations referring to the same occupation, used interchangeably; the construction of pyramids in Egypt were some of the first instances of large structure constructions. Other ancient historic civil engineering constructions include the Qanat water management system the Parthenon by Iktinos in Ancient Greece, the Appian Way by Roman engineers, the Great Wall of China by General Meng T'ien under orders from Ch'in Emperor Shih Huang Ti and the stupas constructed in ancient Sri Lanka like the Jetavanaramaya and the extensive irrigation works in Anuradhapura; the Romans developed civil structures throughout their empire, including aqueducts, harbors, bridges and roads. In the 18th century, the term civil engineering was coined to incorporate all things civilian as opposed to military engineering.
The first self-proclaimed civil engineer was John Smeaton. In 1771 Smeaton and some of his colleagues formed the Smeatonian Society of Civil Engineers, a group of leaders of the profession who met informally over dinner. Though there was evidence of some technical meetings, it was little more than a social society. In 1818 the Institution of Civil Engineers was founded in London, in 1820 the eminent engineer Thomas Telford became its first president; the institution received a Royal Charter in 1828, formally recognising civil engineering as a profession. Its charter defined civil engineering as:the art of directing the great sources of power in nature for the use and convenience of man, as the means of production and of traffic in states, both for external and internal trade, as applied in the construction of roads, aqueducts, river navigation and docks for internal intercourse and exchange, in the construction of ports, moles and lighthouses, in the art of navigation by artificial power for the purposes of commerce, in the construction and application of machinery, in the drainage of cities and towns.
The first private college to teach civil engineering in the United States was Norwich University, founded in 1819 by Captain Alden Partridge. The first degree in civil engineering in the United States was awarded by Rensselaer Polytechnic Institute in 1835; the first such degree to be awarded to a woman was granted by Cornell University to Nora Stanton Blatch in 1905. In the UK during the early 19th century, the division between civil engineering and military engineering, coupled with the demands of the Industrial Revolution, spawned new engineering education initiatives: the Class of Civil Engineering and Mining was founded at King's College London in 1838 as a response to the growth of the railway system and the need for more qualified engineers, the private College for Civil Engineers in Putney was established in 1839, the UK's first Chair of Engineering was established at the University of Glasgow in 1840. Civil engineers possess an academic degree in civil engineering; the length of study is three to five years, the completed degree is designated as a bachelor
Digital electronics or digital circuits are electronics that operate on digital signals. In contrast, analog circuits manipulate analog signals whose performance is more subject to manufacturing tolerance, signal attenuation and noise. Digital techniques are helpful because it is a lot easier to get an electronic device to switch into one of a number of known states than to reproduce a continuous range of values. Digital electronic circuits are made from large assemblies of logic gates, simple electronic representations of Boolean logic functions; the binary number system was refined by Gottfried Wilhelm Leibniz and he established that by using the binary system, the principles of arithmetic and logic could be joined. Digital logic. In an 1886 letter, Charles Sanders Peirce described how logical operations could be carried out by electrical switching circuits. Vacuum tubes replaced relays for logic operations. Lee De Forest's modification, in 1907, of the Fleming valve can be used as an AND gate.
Ludwig Wittgenstein introduced a version of the 16-row truth table as proposition 5.101 of Tractatus Logico-Philosophicus. Walther Bothe, inventor of the coincidence circuit, shared the 1954 Nobel Prize in physics, for the first modern electronic AND gate in 1924. Mechanical analog computers started appearing in the first century and were used in the medieval era for astronomical calculations. In World War II, mechanical analog computers were used for specialized military applications such as calculating torpedo aiming. During this time the first electronic digital computers were developed, they were the size of a large room, consuming as much power as several hundred modern personal computers. The Z3 was an electromechanical computer designed by Konrad Zuse. Finished in 1941, it was the world's first working programmable automatic digital computer, its operation was facilitated by the invention of the vacuum tube in 1904 by John Ambrose Fleming. At the same time that digital calculation replaced analog, purely electronic circuit elements soon replaced their mechanical and electromechanical equivalents.
The bipolar junction transistor was invented in 1947. From 1955 onwards, transistors replaced vacuum tubes in computer designs, giving rise to the "second generation" of computers. Compared to vacuum tubes, transistors have many advantages: they are smaller, require less power than vacuum tubes, so give off less heat. Silicon junction transistors were much more reliable than vacuum tubes and had longer, service life. Transistorized computers could contain tens of thousands of binary logic circuits in a compact space. At the University of Manchester, a team under the leadership of Tom Kilburn designed and built a machine using the newly developed transistors instead of vacuum tubes, their first transistorised computer and the first in the world, was operational by 1953, a second version was completed there in April 1955. While working at Texas Instruments in July 1958, Jack Kilby recorded his initial ideas concerning the integrated circuit successfully demonstrated the first working integrated on 12 September 1958.
This new technique allowed for quick, low-cost fabrication of complex circuits by having a set of electronic circuits on one small plate of semiconductor material silicon. In the early days of integrated circuits, each chip was limited to only a few transistors, the low degree of integration meant the design process was simple. Manufacturing yields were quite low by today's standards; as the technology progressed, millions billions of transistors could be placed on one chip, good designs required thorough planning, giving rise to new design methods. An advantage of digital circuits when compared to analog circuits is that signals represented digitally can be transmitted without degradation caused by noise. For example, a continuous audio signal transmitted as a sequence of 1s and 0s, can be reconstructed without error, provided the noise picked up in transmission is not enough to prevent identification of the 1s and 0s. In a digital system, a more precise representation of a signal can be obtained by using more binary digits to represent it.
While this requires more digital circuits to process the signals, each digit is handled by the same kind of hardware, resulting in an scalable system. In an analog system, additional resolution requires fundamental improvements in the linearity and noise characteristics of each step of the signal chain. With computer-controlled digital systems, new functions to be added through software revision and no hardware changes; this can be done outside of the factory by updating the product's software. So, the product's design errors can be corrected. Information storage can be easier in digital systems; the noise immunity of digital systems permits data to be retrieved without degradation. In an analog system, noise from aging and wear degrade. In a digital system, as long as the total noise is below a certain level, the information can be recovered perfectly; when more significant noise is present, the use of redundancy permits the recovery of the original data provided too many errors do not occur. In some cases, digital circuits use more energy than analog circuits to accomplish the same tasks, thus producing more heat which increases the complexity of the circuits such as the inclusion of heat sinks.
In portable or battery-powered systems this can limit use of digital systems. For example, battery-powered cellular telephones use