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Carl Adam Petri
Carl Adam Petri (12 July 1926 in Leipzig – 2 July 2010 in Siegburg) was a German mathematician and computer scientist. Life and work Petri created his major scientific contribution, the concept of the Petri net, in 1939 at the age of 13, for the purpose of describing chemical processes. In 1941, his father told him about Konrad Zuse's work on computing machines and Carl Adam started building his own analog computer. After earning his Abitur at Thomasschule in 1944, he was drafted into the Wehrmacht. He was taken into British captivity until 1949, when he departed England. Petri started studying mathematics at the Technische Hochschule Hannover (today, the Leibniz University Hannover) in 1950. He documented Petri nets in 1962 as part of his dissertation, (Communication with automata). From 1959 until 1962 he worked at the University of Bonn and received his PhD degree in 1962 from the Technische Universität Darmstadt. From 1963 to 1968 he established and directed the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Leipzig
Leipzig ( , ; Upper Saxon: ) is the most populous city in the German state of Saxony. Leipzig's population of 605,407 inhabitants (1.1 million in the larger urban zone) as of 2021 places the city as Germany's eighth most populous, as well as the second most populous city in the area of the former East Germany after (East) Berlin. Together with Halle (Saale), the city forms the polycentric Leipzig-Halle Conurbation. Between the two cities (in Schkeuditz) lies Leipzig/Halle Airport. Leipzig is located about southwest of Berlin, in the southernmost part of the North German Plain (known as Leipzig Bay), at the confluence of the White Elster River (progression: ) and two of its tributaries: the Pleiße and the Parthe. The name of the city and those of many of its boroughs are of Slavic origin. Leipzig has been a trade city since at least the time of the Holy Roman Empire. The city sits at the intersection of the Via Regia and the Via Imperii, two important medieval trad ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Analog Computer
An analog computer or analogue computer is a type of computer that uses the continuous variation aspect of physical phenomena such as electrical, mechanical, or hydraulic quantities (''analog signals'') to model the problem being solved. In contrast, digital computers represent varying quantities symbolically and by discrete values of both time and amplitude (digital signals). Analog computers can have a very wide range of complexity. Slide rules and nomograms are the simplest, while naval gunfire control computers and large hybrid digital/analog computers were among the most complicated. Complex mechanisms for process control and protective relays used analog computation to perform control and protective functions. Analog computers were widely used in scientific and industrial applications even after the advent of digital computers, because at the time they were typically much faster, but they started to become obsolete as early as the 1950s and 1960s, although they remaine ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Network Theory
Network theory is the study of graphs as a representation of either symmetric relations or asymmetric relations between discrete objects. In computer science and network science, network theory is a part of graph theory: a network can be defined as a graph in which nodes and/or edges have attributes (e.g. names). Network theory has applications in many disciplines including statistical physics, particle physics, computer science, electrical engineering, biology, archaeology, economics, finance, operations research, climatology, ecology, public health, sociology, and neuroscience. Applications of network theory include logistical networks, the World Wide Web, Internet, gene regulatory networks, metabolic networks, social networks, epistemological networks, etc.; see List of network theory topics for more examples. Euler's solution of the Seven Bridges of Königsberg problem is considered to be the first true proof in the theory of networks. Network optimization Network pr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Workflow Management System
A workflow management system (WfMS or WFMS) provides an infrastructure for the set-up, performance and monitoring of a defined sequence of tasks, arranged as a workflow application. International standards There are several international standards-setting bodies in the field of workflow management: * Workflow Management Coalition * World Wide Web Consortium * Organization for the Advancement of Structured Information Standards * WS-BPEL 2.0 (integration-centric) and WS-BPEL4People (human task-centric) published by OASIS Standards Body. The underlying theoretical basis of workflow management is the mathematical concept of a Petri net. Each of the workflow models has tasks (nodes) and dependencies between the nodes. Tasks are activated when the dependency conditions are fulfilled. Workflows for people WfMS allow the user to define different workflows for different types of jobs or processes. For example, in a manufacturing setting, a design document might be automatically routed fro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Complex System
A complex system is a system composed of many components which may interact with each other. Examples of complex systems are Earth's global climate, organisms, the human brain, infrastructure such as power grid, transportation or communication systems, complex software and electronic systems, social and economic organizations (like cities), an ecosystem, a living cell, and ultimately the entire universe. Complex systems are systems whose behavior is intrinsically difficult to model due to the dependencies, competitions, relationships, or other types of interactions between their parts or between a given system and its environment. Systems that are "complex" have distinct properties that arise from these relationships, such as nonlinearity, emergence, spontaneous order, adaptation, and feedback loops, among others. Because such systems appear in a wide variety of fields, the commonalities among them have become the topic of their independent area of research. In many cases, i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Distributed Computing
A distributed system is a system whose components are located on different computer network, networked computers, which communicate and coordinate their actions by message passing, passing messages to one another from any system. Distributed computing is a field of computer science that studies distributed systems. The components of a distributed system interact with one another in order to achieve a common goal. Three significant challenges of distributed systems are: maintaining concurrency of components, overcoming the clock synchronization, lack of a global clock, and managing the independent failure of components. When a component of one system fails, the entire system does not fail. Examples of distributed systems vary from service-oriented architecture, SOA-based systems to massively multiplayer online games to peer-to-peer, peer-to-peer applications. A computer program that runs within a distributed system is called a distributed program, and ''distributed programming' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Parallel Computing
Parallel computing is a type of computation in which many calculations or processes are carried out simultaneously. Large problems can often be divided into smaller ones, which can then be solved at the same time. There are several different forms of parallel computing: bit-level, instruction-level, data, and task parallelism. Parallelism has long been employed in high-performance computing, but has gained broader interest due to the physical constraints preventing frequency scaling.S.V. Adve ''et al.'' (November 2008)"Parallel Computing Research at Illinois: The UPCRC Agenda" (PDF). Parallel@Illinois, University of Illinois at Urbana-Champaign. "The main techniques for these performance benefits—increased clock frequency and smarter but increasingly complex architectures—are now hitting the so-called power wall. The computer industry has accepted that future performance increases must largely come from increasing the number of processors (or cores) on a die, rather than m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Academia Europaea
The Academia Europaea is a pan-European Academy of Humanities, Letters, Law, and Sciences. The Academia was founded in 1988 as a functioning Europe-wide Academy that encompasses all fields of scholarly inquiry. It acts as co-ordinator of European interests in national research agencies. History The concept of a 'European Academy of Sciences' was raised at a meeting in Paris of the European Ministers of Science in 1985. The initiative was taken by the Royal Society (United Kingdom) which resulted in a meeting in London in June 1986 of Arnold Burgen (United Kingdom), Hubert Curien (France), Umberto Colombo (Italy), David Magnusson (Sweden), Eugen Seibold (Germany) and Ruurd van Lieshout (the Netherlands) – who agreed to the need for a new body. The two key purposes of Academia Europaea are: * express ideas and opinions of individual scientists from Europe * act as co-ordinator of European interests in national research agencies It does not aim to replace existing national a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
University Of Hamburg
The University of Hamburg (german: link=no, Universität Hamburg, also referred to as UHH) is a public research university in Hamburg, Germany. It was founded on 28 March 1919 by combining the previous General Lecture System ('' Allgemeines Vorlesungswesen''), the Hamburg Colonial Institute ('' Hamburgisches Kolonialinstitut''), and the Academic College ('' Akademisches Gymnasium''). The main campus is located in the central district of Rotherbaum, with affiliated institutes and research centres distributed around the city-state. The university has been ranked in the top 200 universities worldwide by the ''Times Higher Education Ranking'', the Shanghai Ranking and the CWTS Leiden Ranking, placing it among the top 1% of global universities. Seven Nobel Prize winners and one Wolf Prize winner are affiliated with UHH. On a national scale, '' U.S. News & World Report'' ranks UHH 7th and ''QS World University Rankings'' 14th out of a total of 426 German institutions of higher educa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gesellschaft Für Mathematik Und Datenverarbeitung
The Fraunhofer Society (german: Fraunhofer-Gesellschaft zur Förderung der angewandten Forschung e.V., lit=Fraunhofer Society for the Advancement of Applied Research) is a German research organization with 76institutes spread throughout Germany, each focusing on different fields of applied science (as opposed to the Max Planck Society, which works primarily on basic science). With some 29,000 employees, mainly scientists and engineers, and with an annual research budget of about €2.8billion, it is the biggest organization for applied research and development services in Europe. Some basic funding for the Fraunhofer Society is provided by the state (the German public, through the federal government together with the states or ''Länder'', "owns" the Fraunhofer Society), but more than 70% of the funding is earned through contract work, either for government-sponsored projects or from industry. It is named after Joseph von Fraunhofer who, as a scientist, an engineer, and an entr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Doctor Of Philosophy
A Doctor of Philosophy (PhD, Ph.D., or DPhil; Latin: or ') is the most common Academic degree, degree at the highest academic level awarded following a course of study. PhDs are awarded for programs across the whole breadth of academic fields. Because it is an earned research degree, those studying for a PhD are required to produce original research that expands the boundaries of knowledge, normally in the form of a Thesis, dissertation, and defend their work before a panel of other experts in the field. The completion of a PhD is often a requirement for employment as a university professor, researcher, or scientist in many fields. Individuals who have earned a Doctor of Philosophy degree may, in many jurisdictions, use the title ''Doctor (title), Doctor'' (often abbreviated "Dr" or "Dr.") with their name, although the proper etiquette associated with this usage may also be subject to the professional ethics of their own scholarly field, culture, or society. Those who teach at ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
