Proceedings of the nineteenth annual ACM symposium on Theory of computing最新文献_第2页

Size-time complexity of Boolean networks for prefix computations 用于前缀计算的布尔网络的大小时间复杂度

Proceedings of the nineteenth annual ACM symposium on Theory of computing Pub Date : 1987-01-01 DOI: 10.1145/28395.28442

G. Bilardi, F. Preparata

引用次数: 12

A new graphy triconnectivity algorithm and its parallelization 一种新的图形三连通算法及其并行化

Proceedings of the nineteenth annual ACM symposium on Theory of computing Pub Date : 1987-01-01 DOI: 10.1145/28395.28431

G. Miller, V. Ramachandran

引用次数: 66

Approximation algorithms for shortest path motion planning 最短路径运动规划的近似算法

Proceedings of the nineteenth annual ACM symposium on Theory of computing Pub Date : 1987-01-01 DOI: 10.1145/28395.28402

K. Clarkson

{"title":"Approximation algorithms for shortest path motion planning","authors":"K. Clarkson","doi":"10.1145/28395.28402","DOIUrl":"https://doi.org/10.1145/28395.28402","url":null,"abstract":"This paper gives approximation algorithms of solving the following motion planning problem: Given a set of polyhedral obstacles and points s and t, find a shortest path from s to t that avoids the obstacles. The paths found by the algorithms are piecewise linear, and the length of a path is the sum of the lengths of the line segments making up the path. Approximation algorithms will be given for versions of this problem in the plane and in three-dimensional space. The algorithms return an &egr;-short path, that is, a path with length within (1 + &egr;) of shortest. Let n be the total number of faces of the polyhedral obstacles, and &egr; a given value satisfying &Ogr; < &egr; ≤ &pgr;. The algorithm for the planar case requires &Ogr;(n log n)/&egr; time to build a data structure of size &Ogr;(n/&egr;). Given points s and t, and &egr;-short path from s to t can be found with the use of the data structure in time &Ogr;(n/&egr; + n log n). The data structure is associated with a new variety of Voronoi diagram. Given obstacles S ⊂ &Egr;3 and points s, t &egr; E3, an &egr;-short path between s and t can be found in &Ogr;(n2&lgr;(n) log(n/&egr;)/&egr;4 + n2 lognp log(n logp)) time, where p is the ratio of the length of the longest obstacle edge to the distance between s to t. The function &lgr;(n) = &agr;(n)&Ogr;(&agr;(n)&Ogr;(1)), where the &agr;(n) is a form of inverse of Ackermann's function. For log(1/&egr;) and log p that are &Ogr;(log n), this bound is &Ogr;(log n2(n)&lgr;(n)/&egr;4).","PeriodicalId":161795,"journal":{"name":"Proceedings of the nineteenth annual ACM symposium on Theory of computing","volume":"21 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1987-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133834491","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: 264

A random NC algorithm for depth first search 深度优先搜索的随机NC算法

Proceedings of the nineteenth annual ACM symposium on Theory of computing Pub Date : 1987-01-01 DOI: 10.1145/28395.28430

A. Aggarwal, Richard J. Anderson

引用次数: 92

Single-factor Hensel lifting and its application to the straight-line complexity of certain polynomials 单因素Hensel提升及其在某些多项式直线复杂度中的应用

Proceedings of the nineteenth annual ACM symposium on Theory of computing Pub Date : 1987-01-01 DOI: 10.1145/28395.28443

E. Kaltofen

{"title":"Single-factor Hensel lifting and its application to the straight-line complexity of certain polynomials","authors":"E. Kaltofen","doi":"10.1145/28395.28443","DOIUrl":"https://doi.org/10.1145/28395.28443","url":null,"abstract":"Three theorems are presented that establish polynomial straight-line complexity for certain operations on polynomials given by straight-line programs of unbounded input degree. The first theorem shows how to compute a higher order partial derivative in a single variable. The other two theorems impose the degree of the output polynomial as a parameter of the length of the output program. First it is shown that if a straight-line program computes an arbitrary power of a multivariate polynomial, that polynomial also admits a polynomial bounded straight-line computation. Second, any factor of a multivariate polynomial given by a division-free straight-line program with relatively prime co-factor also admits a straight-line computation of length polynomial in the input length and the degree of the factor. This result is based on a new Hensel lifting process, one where only one factor image is lifted back to the original factor. As an application we get that the greatest common divisor of polynomials given by a division-free straight-line program has polynomial straight-line complexity in terms of the input length and its own degree.","PeriodicalId":161795,"journal":{"name":"Proceedings of the nineteenth annual ACM symposium on Theory of computing","volume":"32 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1987-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121073151","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: 41

On hiding information from an oracle 关于对oracle隐藏信息

Proceedings of the nineteenth annual ACM symposium on Theory of computing Pub Date : 1987-01-01 DOI: 10.1145/28395.28417

M. Abadi, J. Feigenbaum, J. Kilian

{"title":"On hiding information from an oracle","authors":"M. Abadi, J. Feigenbaum, J. Kilian","doi":"10.1145/28395.28417","DOIUrl":"https://doi.org/10.1145/28395.28417","url":null,"abstract":"We consider the problem of computing with encrypted data. Player A wishes to know the value ƒ(x) for some x but lacks the power to compute it. Player B has the power to compute ƒ and is willing to send ƒ(y) to A if she sends him y, for any y. Informally, an encryption scheme for the problem ƒ is a method by which A, using her inferior resources, can transform the cleartext instance x into an encrypted instance y, obtain ƒ(y) from B, and infer ƒ(x) from ƒ(y) in such a way that B cannot infer x from y. When such an encryption scheme exists, we say that ƒ is encryptable. The framework defined in this paper enables us to prove precise statements about what an encrypted instance hides and what it leaks, in an information-theoretic sense. Our definitions are cast in the language of probability theory and do not involve assumptions such as the intractability of factoring or the existence of one-way functions. We use our framework to describe encryption schemes for some natural problems in NP ⋒ CoNP. We also consider the following generalization of encryption schemes. Player A, who is limited to probabilistic polynomial time, wishes to guess the value ƒ(x) with probability at least 1/2 + 1/|x|c of being correct, for some constant c. Player B can compute any function and generate arbitrary probability distributions. Players A and B can interact for a polynomial number of rounds by sending polynomial-sized messages. We prove a strong negative result: there is no such generalized encryption scheme for SAT that leaks no more than the size of x (unless the polynomial hierarchy collapses at the second level).","PeriodicalId":161795,"journal":{"name":"Proceedings of the nineteenth annual ACM symposium on Theory of computing","volume":"45 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1987-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121157916","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: 316

Realistic analysis of some randomized algorithms 一些随机化算法的现实分析

Proceedings of the nineteenth annual ACM symposium on Theory of computing Pub Date : 1987-01-01 DOI: 10.1145/28395.28444

E. Bach

引用次数: 66

The complexity of cutting convex polytypes 切割凸型的复杂性

Proceedings of the nineteenth annual ACM symposium on Theory of computing Pub Date : 1987-01-01 DOI: 10.1145/28395.28403

B. Chazelle, H. Edelsbrunner, L. Guibas

引用次数: 7

Efficiency considerations in using semi-random sources 使用半随机源时的效率考虑

Proceedings of the nineteenth annual ACM symposium on Theory of computing Pub Date : 1987-01-01 DOI: 10.1145/28395.28413

U. Vazirani

引用次数: 67

Analysis of backoff protocols for multiple access channels 多接入信道退避协议分析

Proceedings of the nineteenth annual ACM symposium on Theory of computing Pub Date : 1987-01-01 DOI: 10.1145/28395.28422

J. Håstad, F. Leighton, B. Rogoff

引用次数: 225