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Shmuel Safra
Shmuel Safra ( he, שמואל ספרא) is an Israeli computer scientist. He is a Professor of Computer Science at Tel Aviv University, Israel. He was born in Jerusalem. Safra's research areas include Computational complexity theory, complexity theory and automata theory. His work in complexity theory includes the classification of Approximation algorithm, approximation problems—showing them NP-hard even for weak factors of approximation—and the theory of PCP (complexity), probabilistically checkable proofs (PCP) and the PCP theorem, which gives stronger characterizations of the class NP (complexity), NP, via a membership proof that can be verified reading only a constant number of its bits. His work on automata theory investigates determinization and complementation of Finite state machine, finite automata over Omega language, infinite strings, in particular, the complexity of such translation for Büchi automaton, Büchi automata, Streett automaton, Streett automata and Rab ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jerusalem
Jerusalem (; he, יְרוּשָׁלַיִם ; ar, القُدس ) (combining the Biblical and common usage Arabic names); grc, Ἱερουσαλήμ/Ἰεροσόλυμα, Hierousalḗm/Hierosóluma; hy, Երուսաղեմ, Erusałēm. is a city in Western Asia. Situated on a plateau in the Judaean Mountains between the Mediterranean Sea, Mediterranean and the Dead Sea, it is one of the List of oldest continuously inhabited cities, oldest cities in the world and is considered to be a holy city for the three major Abrahamic religions: Judaism, Christianity, and Islam. Both Israelis and Palestinians claim Jerusalem as their Capital city, capital, as Israel maintains its primary governmental institutions there and the State of Palestine ultimately foresees it as its seat of power. Because of this dispute, Status of Jerusalem, neither claim is widely recognized internationally. Throughout History of Jerusalem, its long history, Jerusalem has been destroyed at least twice, Sie ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Büchi Automaton
In computer science and automata theory, a deterministic Büchi automaton is a theoretical machine which either accepts or rejects infinite inputs. Such a machine has a set of states and a transition function, which determines which state the machine should move to from its current state when it reads the next input character. Some states are accepting states and one state is the start state. The machine accepts an input if and only if it will pass through an accepting state infinitely many times as it reads the input. A non-deterministic Büchi automaton, later referred to just as a Büchi automaton, has a transition function which may have multiple outputs, leading to many possible paths for the same input; it accepts an infinite input if and only if some possible path is accepting. Deterministic and non-deterministic Büchi automata generalize deterministic finite automata and nondeterministic finite automata to infinite inputs. Each are types of ω-automata. Büchi automata rec ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Theoretical Computer Scientists
A theory is a rational type of abstract thinking about a phenomenon, or the results of such thinking. The process of contemplative and rational thinking is often associated with such processes as observational study or research. Theories may be scientific, belong to a non-scientific discipline, or no discipline at all. Depending on the context, a theory's assertions might, for example, include generalized explanations of how nature works. The word has its roots in ancient Greek, but in modern use it has taken on several related meanings. In modern science, the term "theory" refers to scientific theories, a well-confirmed type of explanation of nature, made in a way consistent with the scientific method, and fulfilling the criteria required by modern science. Such theories are described in such a way that scientific tests should be able to provide empirical support for it, or empirical contradiction ("falsify") of it. Scientific theories are the most reliable, rigorous, and compr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
People From Jerusalem
A person ( : people) is a being that has certain capacities or attributes such as reason, morality, consciousness or self-consciousness, and being a part of a culturally established form of social relations such as kinship, ownership of property, or legal responsibility. The defining features of personhood and, consequently, what makes a person count as a person, differ widely among cultures and contexts. In addition to the question of personhood, of what makes a being count as a person to begin with, there are further questions about personal identity and self: both about what makes any particular person that particular person instead of another, and about what makes a person at one time the same person as they were or will be at another time despite any intervening changes. The plural form "people" is often used to refer to an entire nation or ethnic group (as in "a people"), and this was the original meaning of the word; it subsequently acquired its use as a plural form of per ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Israeli Jews
Israeli Jews or Jewish Israelis ( he, יהודים ישראלים, translit=Yehudim Yisraelim) are Israeli citizens and nationals who are Jewish through either their Jewish ethnicity and/or their adherence to Judaism. The term also includes the descendants of Jewish Israelis who have emigrated and settled outside of the State of Israel. Alongside Samaritans and populations from the Jewish diaspora scattered outside of the Land of Israel, Jewish Israelis comprise the modern descendants of the ancient Israelites and Hebrews. They are predominantly found in Israel and the Western world, as well as in other countries worldwide in smaller numbers. The overwhelming majority of Israeli Jews speak Hebrew, a Semitic language, as their native tongue. Israel, the Jewish state, is the only country that has a Jewish-majority population, and is currently home to approximately half of the world's Jews. The Jewish population in Israel comprises all of the communities of the Jewish diaspo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Israeli Computer Scientists
Israeli may refer to: * Something of, from, or related to the State of Israel * Israelis, citizens or permanent residents of the State of Israel * Modern Hebrew, a language * ''Israeli'' (newspaper), published from 2006 to 2008 * Guni Israeli (born 1984), Israeli basketball player See also * Israelites, the ancient people of the Land of Israel * List of Israelis Israelis ( he, ישראלים ''Yiśraʾelim'') are the citizens or permanent residents of the State of Israel, a multiethnic state populated by people of different ethnic backgrounds. The largest ethnic groups in Israel are Jews (75%), foll ... {{disambiguation Language and nationality disambiguation pages ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Living People
Related categories * :Year of birth missing (living people) / :Year of birth unknown * :Date of birth missing (living people) / :Date of birth unknown * :Place of birth missing (living people) / :Place of birth unknown * :Year of death missing / :Year of death unknown * :Date of death missing / :Date of death unknown * :Place of death missing / :Place of death unknown * :Missing middle or first names See also * :Dead people * :Template:L, which generates this category or death years, and birth year and sort keys. : {{DEFAULTSORT:Living people 21st-century people People by status ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vertex Cover Problem
In graph theory, a vertex cover (sometimes node cover) of a graph is a set of vertices that includes at least one endpoint of every edge of the graph. In computer science, the problem of finding a minimum vertex cover is a classical optimization problem. It is NP-hard, so it cannot be solved by a polynomial-time algorithm if P ≠ NP. Moreover, it is hard to approximate – it cannot be approximated up to a factor smaller than 2 if the unique games conjecture is true. On the other hand, it has several simple 2-factor approximations. It is a typical example of an NP-hard optimization problem that has an approximation algorithm. Its decision version, the vertex cover problem, was one of Karp's 21 NP-complete problems and is therefore a classical NP-complete problem in computational complexity theory. Furthermore, the vertex cover problem is fixed-parameter tractable and a central problem in parameterized complexity theory. The minimum vertex cover problem can be formulated as ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Set Cover Problem
The set cover problem is a classical question in combinatorics, computer science, operations research, and complexity theory. It is one of Karp's 21 NP-complete problems shown to be NP-complete in 1972. Given a set of elements (called the universe) and a collection of sets whose union equals the universe, the set cover problem is to identify the smallest sub-collection of whose union equals the universe. For example, consider the universe and the collection of sets Clearly the union of is . However, we can cover all of the elements with the following, smaller number of sets: More formally, given a universe \mathcal and a family \mathcal of subsets of \mathcal, a ''cover'' is a subfamily \mathcal\subseteq\mathcal of sets whose union is \mathcal. In the set covering decision problem, the input is a pair (\mathcal,\mathcal) and an integer k; the question is whether there is a set covering of size k or less. In the set covering optimization problem, the input is a pair (\ma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bull Graph
In the mathematical field of graph theory, the bull graph is a planar undirected graph with 5 vertices and 5 edges, in the form of a triangle with two disjoint pendant edges. It has chromatic number 3, chromatic index 3, radius 2, diameter 3 and girth 3. It is also a self-complementary graph, a block graph, a split graph, an interval graph, a claw-free graph, a 1- vertex-connected graph and a 1- edge-connected graph. Bull-free graphs A graph is bull-free if it has no bull as an induced subgraph. The triangle-free graphs are bull-free graphs, since every bull contains a triangle. The strong perfect graph theorem was proven for bull-free graphs long before its proof for general graphs, and a polynomial time recognition algorithm for Bull-free perfect graphs is known. Maria Chudnovsky and Shmuel Safra have studied bull-free graphs more generally, showing that any such graph must have either a large clique or a large independent set (that is, the Erdős–Hajnal conjecture hol ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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