Proceedings 39th Annual Symposium on Foundations of Computer Science (Cat. No.98CB36280)最新文献_第4页

Concurrent reachability games 并发可达性游戏

Proceedings 39th Annual Symposium on Foundations of Computer Science (Cat. No.98CB36280) Pub Date : 1998-11-08 DOI: 10.1109/SFCS.1998.743507

L. D. Alfaro, T. Henzinger, O. Kupferman

{"title":"Concurrent reachability games","authors":"L. D. Alfaro, T. Henzinger, O. Kupferman","doi":"10.1109/SFCS.1998.743507","DOIUrl":"https://doi.org/10.1109/SFCS.1998.743507","url":null,"abstract":"An open system can be modeled as a two-player game between the system and its environment. At each round of the game, player 1 (the system) and player 2 (the environment) independently and simultaneously choose moves, and the two choices determine the next state of the game. Properties of open systems can be modeled as objectives of these two-player games. For the basic objective of reachability-can player 1 force the game to a given set of target states?-there are three types of winning states, according to the degree of certainty with which player 1 can reach the target. From type-1 states, player 1 has a deterministic strategy to always reach the target. From type-2 states, player 1 has a randomized strategy to reach the target with probability 1. From type-3 states, player 1 has for every real /spl epsi/>0 a randomized strategy to reach the target with probability greater than 1-/spl epsi/. We show that for finite state spaces, all three sets of winning states can be computed in polynomial time: type-1 states in linear time, and type-2 and type-3 states in quadratic time. The algorithms to compute the three sets of winning states also enable the construction of the winning and spoiling strategies. Finally, we apply our results by introducing a temporal logic in which all three kinds of winning conditions can be specified, and which can be model checked in polynomial time. This logic, called Randomized ATL, is suitable for reasoning about randomized behavior in open (two-agent) as well as multi-agent systems.","PeriodicalId":228145,"journal":{"name":"Proceedings 39th Annual Symposium on Foundations of Computer Science (Cat. No.98CB36280)","volume":"110 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1998-11-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133658111","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}

引用次数: 228

An improved exponential-time algorithm for k-SAT 一种改进的k-SAT指数时间算法

Proceedings 39th Annual Symposium on Foundations of Computer Science (Cat. No.98CB36280) Pub Date : 1998-11-08 DOI: 10.1109/SFCS.1998.743513

R. Paturi, P. Pudlák, M. Saks, F. Zane

{"title":"An improved exponential-time algorithm for k-SAT","authors":"R. Paturi, P. Pudlák, M. Saks, F. Zane","doi":"10.1109/SFCS.1998.743513","DOIUrl":"https://doi.org/10.1109/SFCS.1998.743513","url":null,"abstract":"We propose and analyze a simple new algorithm for finding satisfying assignments of Boolean formulae in conjunctive normal form. The algorithm, ResolveSat, is a randomized variant of the DDL procedure by M. Davis et al. (1962) or Davis-Putnam procedure. Rather than applying the DLL procedure to the input formula F, however; ResolveSat enlarges F by adding additional clauses using limited resolution before performing DLL. The basic idea behind our analysis is the same as by R. Paturi (1997): a critical clause for a variable at a satisfying assignment gives rise to a unit clause in the DLL procedure with sufficiently high probability, thus increasing the probability of finding a satisfying assignment. In the current paper, we analyze the effect of multiple critical clauses (obtained through resolution) in producing unit clauses. We show that, for each k, the running time of ResolveSat on a k-CNF formula is significantly better than 2/sup n/, even in the worst case. In particular we show that the algorithm finds a satisfying assignment of a general 3-CNF in time O(2/sup .446n/) with high probability; where the best previous algorithm has running time O(2/sup .582n/). We obtain a better upper bound of O(2/sup (2ln2-1)/n+0(n))=O(2/sup 0.387n/) for 3-CNF that have at most one satisfying assignment (unique k-SAT). For each k, the bounds for general k-CNF are the best known for the worst-case complexity of finding a satisfying solution for k-SAT, the idea of succinctly encoding satisfying solutions can be applied to obtain lower bounds on circuit site. Here, we exhibit a function f such that any depth-3 AND-OR circuit with bottom fan-in bounded by k requires /spl Omega/(2(c/sub k/n/k)) gates (with c/sub k/>1). This is the first such lower bound with c/sub k/>1.","PeriodicalId":228145,"journal":{"name":"Proceedings 39th Annual Symposium on Foundations of Computer Science (Cat. No.98CB36280)","volume":"104 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1998-11-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132120018","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}

引用次数: 335

Pattern matching for spatial point sets 空间点集的模式匹配

Proceedings 39th Annual Symposium on Foundations of Computer Science (Cat. No.98CB36280) Pub Date : 1998-11-08 DOI: 10.1109/SFCS.1998.743439

David E. Cardoze, L. Schulman

引用次数: 70

Local divergence of Markov chains and the analysis of iterative load-balancing schemes 马尔可夫链的局部散度及迭代负载均衡方案分析

Proceedings 39th Annual Symposium on Foundations of Computer Science (Cat. No.98CB36280) Pub Date : 1998-11-08 DOI: 10.1109/SFCS.1998.743520

Y. Rabani, A. Sinclair, R. Wanka

引用次数: 148

The security of individual RSA bits 单个RSA位的安全性

Proceedings 39th Annual Symposium on Foundations of Computer Science (Cat. No.98CB36280) Pub Date : 1998-11-08 DOI: 10.1109/SFCS.1998.743502

J. Håstad, M. Näslund

引用次数: 48

Local search in smooth convex sets 光滑凸集的局部搜索

Proceedings 39th Annual Symposium on Foundations of Computer Science (Cat. No.98CB36280) Pub Date : 1998-11-08 DOI: 10.1109/SFCS.1998.743446

R. Kannan, Andreas Nolte

引用次数: 4

Approximating a finite metric by a small number of tree metrics 用少量的树形度量来近似有限的度量

Proceedings 39th Annual Symposium on Foundations of Computer Science (Cat. No.98CB36280) Pub Date : 1998-11-08 DOI: 10.1109/SFCS.1998.743488

M. Charikar, C. Chekuri, Ashish Goel, S. Guha, Serge A. Plotkin

{"title":"Approximating a finite metric by a small number of tree metrics","authors":"M. Charikar, C. Chekuri, Ashish Goel, S. Guha, Serge A. Plotkin","doi":"10.1109/SFCS.1998.743488","DOIUrl":"https://doi.org/10.1109/SFCS.1998.743488","url":null,"abstract":"Y. Bartal (1996, 1998) gave a randomized polynomial time algorithm that given any n point metric G, constructs a tree T such that the expected stretch (distortion) of any edge is at most O (log n log log n). His result has found several applications and in particular has resulted in approximation algorithms for many graph optimization problems. However approximation algorithms based on his result are inherently randomized. In this paper we derandomize the use of Bartal's algorithm in the design of approximation algorithms. We give an efficient polynomial time algorithm that given a finite n point metric G, constructs O(n log n) trees and a probability distribution /spl mu/ on them such that the expected stretch of any edge of G in a tree chosen according to /spl mu/ is at most O(log n log log n). Our result establishes that finite metrics can be probabilistically approximated by a small number of tree metrics. We obtain the first deterministic approximation algorithms for buy-at-bulk network design and vehicle routing; in addition we subsume results from our earlier work on derandomization. Our main result is obtained by a novel view of probabilistic approximation of metric spaces as a deterministic optimization problem via linear programming.","PeriodicalId":228145,"journal":{"name":"Proceedings 39th Annual Symposium on Foundations of Computer Science (Cat. No.98CB36280)","volume":"275 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1998-11-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122918137","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}

引用次数: 202

Approximation of diameters: randomization doesn't help 直径的近似:随机化没有帮助

Proceedings 39th Annual Symposium on Foundations of Computer Science (Cat. No.98CB36280) Pub Date : 1998-11-08 DOI: 10.1109/SFCS.1998.743451

A. Brieden, P. Gritzmann, R. Kannan, V. Klee, L. Lovász, M. Simonovits

引用次数: 34

Satisfiability of word equations with constants is in exponential space 具有常数的词方程在指数空间中是可满足的

Proceedings 39th Annual Symposium on Foundations of Computer Science (Cat. No.98CB36280) Pub Date : 1998-11-08 DOI: 10.1109/SFCS.1998.743434

C. Gutiérrez

引用次数: 41

Protocols for asymmetric communication channels 非对称通信通道的协议

Proceedings 39th Annual Symposium on Foundations of Computer Science (Cat. No.98CB36280) Pub Date : 1998-11-08 DOI: 10.1109/SFCS.1998.743503

M. Adler, B. Maggs

{"title":"Protocols for asymmetric communication channels","authors":"M. Adler, B. Maggs","doi":"10.1109/SFCS.1998.743503","DOIUrl":"https://doi.org/10.1109/SFCS.1998.743503","url":null,"abstract":"In this paper we examine the problem of sending an n-bit data item from a client to a server across an asymmetric communication channel. We demonstrate that there are scenarios in which a high-speed link from the server to the client can be used to greatly reduce the number of bits sent from the client to the server across a slower link. In particular, we assume that the data item is drawn from a probability distribution D that is known to the server but not to the client. We present several protocols in which the expected number of bits transmitted by the server and client are O(n) and O(H(D)+1), respectively, where H(D) is the binary entropy of D (and can range from 0 to n). These protocols are within a small constant factor of optimal in terms of the number of bits sent by the client. The expected number of rounds of communication between the server and client in the simplest of our protocols is O(H(D)). We also give a protocol for which the expected number of rounds is only 0(1), but which requires more computational effort on the part of the server. A third technique provides a tradeoff between the computational effort and the number of rounds.","PeriodicalId":228145,"journal":{"name":"Proceedings 39th Annual Symposium on Foundations of Computer Science (Cat. No.98CB36280)","volume":"6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1998-11-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122461785","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}

引用次数: 36