20th Annual Symposium on Foundations of Computer Science (sfcs 1979)最新文献

{"title":"Transforming static data structures to dynamic structures","authors":"J. Saxe, J. Bentley","doi":"10.1109/SFCS.1979.47","DOIUrl":"https://doi.org/10.1109/SFCS.1979.47","url":null,"abstract":"In this paper we will investigate transformations that serve as tools in the design of new data structures. Specifically, we study general methods for converting static structures (in which all elements are known before any searches are performed) to dynamic structures (in which the insertion of a new element can be mixed with searches). We will see three classes of such transformations (each based on a different counting scheme for representing the integers) and then use a combinatorial model to show the optimality of many of the transformations. Issues such as online data structures and deletion of elements are also examined. To demonstrate the applicability of these tools, we will study six new data structures that have been developed by applying the transformations.","PeriodicalId":311166,"journal":{"name":"20th Annual Symposium on Foundations of Computer Science (sfcs 1979)","volume":"39 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1979-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121572337","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Modeling communications protocols by automata","authors":"A. Aho, J. Ullman, M. Yannakakis","doi":"10.1109/SFCS.1979.23","DOIUrl":"https://doi.org/10.1109/SFCS.1979.23","url":null,"abstract":"Using a pair of finite-state automata to model the transmitter-receiver protocol in a data communications system, we derive lower bounds on the size of automata needed to achieve reliable communication across an error-phone channel. We also show that, at the cost of increasing the size of the automata, a transmission rate close to the theoretical maximum can be achieved.","PeriodicalId":311166,"journal":{"name":"20th Annual Symposium on Foundations of Computer Science (sfcs 1979)","volume":"4 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1979-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115262768","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Random walks, universal traversal sequences, and the complexity of maze problems","authors":"R. Aleliunas, R. Karp, R. Lipton, L. Lovász, C. Rackoff","doi":"10.1109/SFCS.1979.34","DOIUrl":"https://doi.org/10.1109/SFCS.1979.34","url":null,"abstract":"It is well known that the reachability problem for directed graphs is logspace-complete for the complexity class NSPACE(log n) , and thus holds the key to the open question of whether DSPACE(logn)= NSPACE(logn) ([3,4,5,6]). Here as usual OSPACE(logn) is the class of languages that are accepted in logn space by deterministic Turing Ma chi nes, wh i 1eNSPACE( log n) i s the c1ass 0 f 1anguages that are accepted in log n space by nondeterministic ones. The reachability problem for undirected graphs has also been considered ([5]), but it has remained an open question whether undirected graph reachability is logspace-complete for NSPACE(logn). Here we derive results suggesting that the undirected reachability problem is structurally different from, and easier than, the directed version. These results are an affirmative answer to a question of S. Cook.","PeriodicalId":311166,"journal":{"name":"20th Annual Symposium on Foundations of Computer Science (sfcs 1979)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1979-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131005315","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Some theoretical aspects of position-location problems","authors":"Y. Yemini","doi":"10.1109/SFCS.1979.39","DOIUrl":"https://doi.org/10.1109/SFCS.1979.39","url":null,"abstract":"The position-location problem is that of computing the coordinates of a set of objects in space (usually a plane) from a sparse set of distance measurements. Because the problem is analogous to that of constructing a pin-Jointed structure from rigid bars (of given respective lengths), it is intimately linked to problems of structural rigidity. In addition to its practical significance, the problem leads to a number of surprising results and intriguing theoretical problems in geometry, combinatorics, and algorithm design. This paper presents some of the theoretical algorithmic aspects of the position-location problem; its major objective is to attract researchers to complexity problems of structural rigidity. Among the major results presented is the discovery of a large class of geometrical decision problems, all of which are randomly decidable (i.e., decidable by a probabilistic polynomial-time algorithm), but many of which seem to be Intractable.","PeriodicalId":311166,"journal":{"name":"20th Annual Symposium on Foundations of Computer Science (sfcs 1979)","volume":"89 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1979-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126393857","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Explicit constructions of linear size superconcentrators","authors":"O. Gabber, Z. Galil","doi":"10.1109/SFCS.1979.16","DOIUrl":"https://doi.org/10.1109/SFCS.1979.16","url":null,"abstract":"We present an explicit construction of an infinite family of N-superconcentrators of density 44. The most economical previously known explicit graphs of this type have density around 60.","PeriodicalId":311166,"journal":{"name":"20th Annual Symposium on Foundations of Computer Science (sfcs 1979)","volume":"68 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1979-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114498805","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Formal languages: Origins and directions","authors":"S. Greibach","doi":"10.1109/SFCS.1979.19","DOIUrl":"https://doi.org/10.1109/SFCS.1979.19","url":null,"abstract":"1. IntIDduction My purpose is to survey the orlglns of the theory of formal languages and automata through 1964 and to indicate some of the main directions which the :-;ttldy of the sub4ect has takc::>n since tIlen. In the discussion of origins, I shall concentrate on those I know best: the work on mathematical linguistics and automatic translation of the 50s and early 60s, which led me into the field. I had hoped to trace the developments since 1964 thIDugh the papers presented at the IEEE Symposia on the FOill1dations of Computer Science (initia11v, Switching Circuit Theory and Logical Design; later, Switching and Automata TI1eory) and the companion, parvenu, AC11 Symposia on the Theory of Computing. This good intention was impossible to sustain, particularly as I moved fIDm the exuberant 60s into the grim 7 Os. LDng gone are the days in which abstracts of one's summer research and the theses of one's best students automatically appeared at the next Conference! Still I shall give pride of place to such cont1'ibutions where possible. There (:il'e at least five (not altogether distinct) sources foY' the ideas developed in fonnal language theory. They Eire: elogic and recursive function theory • svitching cil'cuit trleory c]IKl emodeling of biological systems., developm::ntal systems and eITBthematical and computational linguistics ·computer prograrmning and the of ALGOL and other Problem Qr)iented lrl.nguages Recursive function theory is ;:3urveyed elsewhel'C in these Proceedings so I shall mention relevant ideas only in passing. The emphasis of this paper is on formal languages, so I shall descrilR only the l'e-lated parts of the development of finite automata theory, skimping 01' skipping purely machine 01' system oriented topics. Phrase structure gpammars wen=? originally cle-scribed by Chomsky [l959a] as a forrna.lization of the Irrrrnediate Constituent (IC) analysis used by lin-tWists ~\"'1 describing thp morpholog:/-aDd syntax' of natural languages. The work on :rn::lchine translation at various institutions used various theories as bases for automatic syntactic analysis t Th ·. and appropriate programming techniques were devised. At the same time, similar methods of syntax specification and programming techniques were used in the definition and implementation of Problem Oriented Programming Languages. In the early 60s, all of these various threads were brought together as it was recognized, and then formally proved, that all these models defined the same class of languages, namely, the family of context-free (CF) phrase structure languages. the publication of the tentative definition of …","PeriodicalId":311166,"journal":{"name":"20th Annual Symposium on Foundations of Computer Science (sfcs 1979)","volume":"20 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1979-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134085332","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Efficient algorithms for simple matroid intersection problems","authors":"H. Gabow, R. Tarjan","doi":"10.1109/SFCS.1979.14","DOIUrl":"https://doi.org/10.1109/SFCS.1979.14","url":null,"abstract":"Given a matroid, where each element has a realvalued cost and is colored red or green; we seek a minimum cost base with exactly q red elements. This is a simple case of the matroid intersection problem. A general algorithm is presented. Its efficiency is illustrated in the special case of finding a minimum spanning tree with q red edges; the time is O(m log log n + n α (n,n) log n). Efficient algorithms are also given for job scheduling matroids and partition matroids. An algorithm is given for finding a minimum spanning tree where a vertex r has prespecified degree; it shows this problem is equivalent to finding a minimum spanning tree, without the degree constraint. An algorithm is given for finding a minimum spanning tree on a directed graph, where the given root r has prespecified degree; the time is O(m log n), the same as for the problem without the degree constraint.","PeriodicalId":311166,"journal":{"name":"20th Annual Symposium on Foundations of Computer Science (sfcs 1979)","volume":"339 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1979-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123404512","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Computational complexity in algebraic function fields","authors":"N. Pippenger","doi":"10.1109/SFCS.1979.11","DOIUrl":"https://doi.org/10.1109/SFCS.1979.11","url":null,"abstract":"The problem solved in this paper is the following. Let x I' xn be indeterminates; let [I' ... , rk be simple radicals, by which is meant let rl' ... , rk be the square roots of rational functions of x I' ... , xn ; and let f I' , fm be simple algebraic Junctions, by which is meant let f I' , fm be rational functions of rl' ... , rk and xI' ... , x(l\" What is the minimum possible cost of computing f I' ... , fm from x I' ... , xn ' if rational operations have cost zero and square root extractions (the only irrational operations allowed) have cost one?","PeriodicalId":311166,"journal":{"name":"20th Annual Symposium on Foundations of Computer Science (sfcs 1979)","volume":"42 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1979-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123438061","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Bijective A-transducers","authors":"H. Maurer, M. Nivat","doi":"10.1109/SFCS.1979.7","DOIUrl":"https://doi.org/10.1109/SFCS.1979.7","url":null,"abstract":"In this paper we study bijective a-transducers. We derive necessary and sufficient conditions on pairs of regular sets (R,S) such that a bijective a-transducer, mapping R cnto S exists. The results obtained allow the systematic construction of an a-transducer, mapping a set R onto a set S bijectively for surprisingly \"different\" regular sets R and S.","PeriodicalId":311166,"journal":{"name":"20th Annual Symposium on Foundations of Computer Science (sfcs 1979)","volume":"29 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1979-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122584255","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Orderings for term-rewriting systems","authors":"N. Dershowitz","doi":"10.1109/SFCS.1979.32","DOIUrl":"https://doi.org/10.1109/SFCS.1979.32","url":null,"abstract":"Methods of proving that a term-rewriting system terminates are presented. They are based on the notion of \"simplification orderings\", orderings in which any term that is homeomorphically embeddable in another is smaller than the other. A particularly useful class of simplification orderings, the \"recursive path orderings\", is defined. Several examples of the use of such orderings in termination proofs are given.","PeriodicalId":311166,"journal":{"name":"20th Annual Symposium on Foundations of Computer Science (sfcs 1979)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1979-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129834860","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}