Proceedings 2001 IEEE International Conference on Cluster Computing最新文献

The complexity of factors of multivariate polynomials 多元多项式因子的复杂性

Proceedings 2001 IEEE International Conference on Cluster Computing Pub Date : 2018-12-17 DOI: 10.1109/SFCS.2001.959912

Peter Burgisser

引用次数: 58

Compact oracles for reachability and approximate distances in planar digraphs 用于平面有向图的可达性和近似距离的紧凑指示符

Proceedings 2001 IEEE International Conference on Cluster Computing Pub Date : 2001-10-14 DOI: 10.1109/SFCS.2001.959898

M. Thorup

引用次数: 315

Approximate shape fitting via linearization 通过线性化近似形状拟合

Proceedings 2001 IEEE International Conference on Cluster Computing Pub Date : 2001-10-14 DOI: 10.1109/SFCS.2001.959881

Sariel Har-Peled, Kasturi R. Varadarajan

引用次数: 30

Randomly colouring graphs with lower bounds on girth and maximum degree 随机上色图形与下界的周长和最大程度

Proceedings 2001 IEEE International Conference on Cluster Computing Pub Date : 2001-10-14 DOI: 10.1109/SFCS.2001.959934

M. Dyer, A. Frieze

引用次数: 72

"Planar" tautologies hard for resolution “平面”重言式难以分辨

Proceedings 2001 IEEE International Conference on Cluster Computing Pub Date : 2001-10-14 DOI: 10.1109/SFCS.2001.959896

Stefan S. Dantchev, Søren Riis

引用次数: 26

Semi-direct product in groups and zig-zag product in graphs: connections and applications 群中的半直积与图中的之字形积:联系与应用

Proceedings 2001 IEEE International Conference on Cluster Computing Pub Date : 2001-10-14 DOI: 10.1109/SFCS.2001.959939

N. Alon, A. Lubotzky, A. Wigderson

{"title":"Semi-direct product in groups and zig-zag product in graphs: connections and applications","authors":"N. Alon, A. Lubotzky, A. Wigderson","doi":"10.1109/SFCS.2001.959939","DOIUrl":"https://doi.org/10.1109/SFCS.2001.959939","url":null,"abstract":"We consider the standard semi-direct product A/spl times/B of finite groups A, B. We show that with certain choices of generators for these three groups, the Cayley graph of A/spl times/B is (essentially) the zigzag product of the Cayley graphs of A and B. Thus, using the results of O. Reingold et al. (2000), the new Cayley graph is an expander if and only if its two components are. We develop some general ways of using this construction to obtain large constant-degree expanding Cayley graphs from small ones. A. Lubotzky and B. Weiss (1993) asked whether expansion is a group property; namely, is being an expander for (a Cayley graph of) a group G depend solely on G and not on the choice of generators. We use the above construction to answer the question in the negative, by showing an infinite family of groups A/sub i//spl times/B/sub i/ which are expanders with one choice of a (constant-size) set of generators and are not with another such choice. It is interesting to note that this problem is still open, though for \"natural\" families of groups like the symmetric groups S/sub n/ or the simple groups PSL(2, p).","PeriodicalId":378126,"journal":{"name":"Proceedings 2001 IEEE International Conference on Cluster Computing","volume":"232 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123361709","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: 72

Designing networks for selfish users is hard 为自私的用户设计网络是困难的

Proceedings 2001 IEEE International Conference on Cluster Computing Pub Date : 2001-10-14 DOI: 10.1109/SFCS.2001.959923

T. Roughgarden

{"title":"Designing networks for selfish users is hard","authors":"T. Roughgarden","doi":"10.1109/SFCS.2001.959923","DOIUrl":"https://doi.org/10.1109/SFCS.2001.959923","url":null,"abstract":"We consider a directed network in which every edge possesses a latency function specifying the time needed to traverse the edge given its congestion. Selfish, noncooperative agents constitute the network traffic and wish to travel from a source s to a sink t as quickly as possible. Since the route chosen by one network user affects the congestion (and hence the latency) experienced by others, we model the problem as a noncooperative game. Assuming each agent controls only a negligible portion of the overall traffic, Nash equilibria in this noncooperative game correspond to s-t flows in which all flow paths have equal latency. We give optimal inapproximability results and approximation algorithms for several network design problems of this type. For example, we prove that for networks with n nodes and continuous, nondecreasing latency functions, there is no approximation algorithm for this problem with approximation ratio less than n/2 (unless P = NP). We also prove this hardness result to be best possible by exhibiting an n/2-approximation algorithm. For networks in which the latency of each edge is a linear function of the congestion, we prove that there is no (4/3 - /spl epsi/)-approximation algorithm for the problem (for any /spl epsi/ > 0, unless P = NP); the existence of a 4/3-approximation algorithm follows easily from existing work, proving this hardness result sharp.","PeriodicalId":378126,"journal":{"name":"Proceedings 2001 IEEE International Conference on Cluster Computing","volume":"26 3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116628548","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: 127

How to go beyond the black-box simulation barrier 如何超越黑盒模拟的障碍

Proceedings 2001 IEEE International Conference on Cluster Computing Pub Date : 2001-10-14 DOI: 10.1109/SFCS.2001.959885

B. Barak

{"title":"How to go beyond the black-box simulation barrier","authors":"B. Barak","doi":"10.1109/SFCS.2001.959885","DOIUrl":"https://doi.org/10.1109/SFCS.2001.959885","url":null,"abstract":"The simulation paradigm is central to cryptography. A simulator is an algorithm that tries to simulate the interaction of the adversary with an honest party, without knowing the private input of this honest party. Almost all known simulators use the adversary's algorithm as a black-box. We present the first constructions of non-black-box simulators. Using these new non-black-box techniques, we obtain several results that were previously proven to be impossible to obtain using black-box simulators. Specifically, assuming the existence of collision resistent hash functions, we construct a new zero-knowledge argument system for NP that satisfies the following properties: 1. This system has a constant number of rounds with negligible soundness error. 2. It remains zero knowledge even when composed concurrently n times, where n is the security parameter. Simultaneously obtaining 1 and 2 has been recently proven to be impossible to achieve using black-box simulators. 3. It is an Arthur-Merlin (public coins) protocol. Simultaneously obtaining 1 and 3 was known to be impossible to achieve with a black-box simulator. 4. It has a simulator that runs in strict polynomial time, rather than in expected polynomial time. All previously known constant-round, negligible-error zero-knowledge arguments utilized expected polynomial-time simulators.","PeriodicalId":378126,"journal":{"name":"Proceedings 2001 IEEE International Conference on Cluster Computing","volume":"82 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121688935","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: 487

Unique sink orientations of cubes 立方体的独特下沉方向

Proceedings 2001 IEEE International Conference on Cluster Computing Pub Date : 2001-10-14 DOI: 10.1109/SFCS.2001.959931

Tibor Szabó, E. Welzl

{"title":"Unique sink orientations of cubes","authors":"Tibor Szabó, E. Welzl","doi":"10.1109/SFCS.2001.959931","DOIUrl":"https://doi.org/10.1109/SFCS.2001.959931","url":null,"abstract":"Suppose we are given (the edge graph of) an n-dimensional hypercube with its edges oriented so that every face has a unique sink. Such an orientation is called a unique sink orientation, and we are interested in finding the unique sink of the whole cube, when the orientation is given implicitly. The basic operation available is the so-called vertex evaluation, where we can access an arbitrary vertex of the cube, for which we obtain the orientations of the incident edges. Unique sink orientations occur when the edges of a deformed geometric n-dimensional cube (i.e., a polytope with the combinatorial structure of a cube) are oriented according to some generic linear function. These orientations are easily seen to be acyclic. The main motivation for studying unique sink orientations are certain linear complementarity problems, which allow this combinatorial abstraction (due to Stickney and Watson, 1978), where orientations with cycles can arise. Similarly, some quadratic optimization problems, like computing the smallest enclosing ball of a finite point set, can be formulated as finding a sink in a unique sink orientation (with cycles possible). For acyclic unique sink orientations, randomized procedures due to Bernd Gartner (1998, 2001) with an expected number of at Most e/sup 2/spl radic/n/ vertex evaluations have been known. For the general case, a simple randomized (3/2)/sup n/ procedure exists (without explicit mention in the literature). We present new algorithms, a deterministic O(1.61/sup n/) procedure and a randomized O((43/20)/sup n/2/)=O(1.47/sup n/) procedure for unique sink orientations. An interesting aspect of these algorithms is that they do not proceed on a path to the sink (in a simplex-like fashion), but they exploit the potential of random access (in the sense of arbitrary access) to any vertex of the cube. We consider this feature the main contribution of the paper. We believe that unique sink orientations have a rich structure, and there is ample space for improvement on the bounds given above.","PeriodicalId":378126,"journal":{"name":"Proceedings 2001 IEEE International Conference on Cluster Computing","volume":"33 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121535078","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: 82

Vickrey prices and shortest paths: what is an edge worth? Vickrey价格和最短路径:一条边值多少钱?

Proceedings 2001 IEEE International Conference on Cluster Computing Pub Date : 2001-10-14 DOI: 10.1109/SFCS.2001.959899

J. Hershberger, S. Suri

{"title":"Vickrey prices and shortest paths: what is an edge worth?","authors":"J. Hershberger, S. Suri","doi":"10.1109/SFCS.2001.959899","DOIUrl":"https://doi.org/10.1109/SFCS.2001.959899","url":null,"abstract":"We solve a shortest path problem that is motivated by recent interest in pricing networks or other computational resources. Informally, how much is an edge in a network worth to a user who wants to send data between two nodes along a shortest path? If the network is a decentralized entity, such as the Internet, in which multiple self-interested agents own different parts of the network, then auction-based pricing seems appropriate. A celebrated result from auction theory shows that the use of Vickrey pricing motivates the owners of the network resources to bid truthfully. In Vickrey's scheme, each agent is compensated in proportion to the marginal utility he brings to the auction. In the context of shortest path routing, an edge's utility is the value by which it lowers the length of the shortest path, i.e., the difference between the shortest path lengths with and without the edge. Our problem is to compute these marginal values for all the edges of the network efficiently. The naive method requires solving the single-source shortest path problem up to n times, for an n-node network. We show that the Vickrey prices for all the edges can be computed in the same asymptotic time complexity as one single-source shortest path problem. This solves an open problem posed by N. Nisan and A. Ronen (1999).","PeriodicalId":378126,"journal":{"name":"Proceedings 2001 IEEE International Conference on Cluster Computing","volume":"129 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124232945","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: 254