Papers published on a yearly basis
Papers
More filters
••
TL;DR: This paper presents a tutorial on the implementation and use of biased random-key genetic algorithms for solving combinatorial optimization problems, illustrating the ease in which sequential and parallel heuristics based on biased Random-Key genetic algorithms can be developed.
Abstract: Random-key genetic algorithms were introduced by Bean (ORSA J. Comput. 6:154---160, 1994) for solving sequencing problems in combinatorial optimization. Since then, they have been extended to handle a wide class of combinatorial optimization problems. This paper presents a tutorial on the implementation and use of biased random-key genetic algorithms for solving combinatorial optimization problems. Biased random-key genetic algorithms are a variant of random-key genetic algorithms, where one of the parents used for mating is biased to be of higher fitness than the other parent. After introducing the basics of biased random-key genetic algorithms, the paper discusses in some detail implementation issues, illustrating the ease in which sequential and parallel heuristics based on biased random-key genetic algorithms can be developed. A survey of applications that have recently appeared in the literature is also given.
432 citations
••
19 Oct 2005TL;DR: An analysis of representative Bit-Torrent traffic provides several new findings regarding the limitations of BitTorrent systems: due to the exponentially decreasing peer arrival rate in reality, service availability in such systems becomes poor quickly, after which it is difficult for the file to be located and downloaded.
Abstract: Existing studies on BitTorrent systems are single-torrent based, while more than 85% of all peers participate in multiple torrents according to our trace analysis. In addition, these studies are not sufficiently insightful and accurate even for single-torrent models, due to some unrealistic assumptions. Our analysis of representative Bit-Torrent traffic provides several new findings regarding the limitations of BitTorrent systems: (1) Due to the exponentially decreasing peer arrival rate in reality, service availability in such systems becomes poor quickly, after which it is difficult for the file to be located and downloaded. (2) Client performance in the BitTorrent-like systems is unstable, and fluctuates widely with the peer population. (3) Existing systems could provide unfair services to peers, where peers with high downloading speed tend to download more and upload less. In this paper, we study these limitations on torrent evolution in realistic environments. Motivated by the analysis and modeling results, we further build a graph based multi-torrent model to study inter-torrent collaboration. Our model quantitatively provides strong motivation for inter-torrent collaboration instead of directly stimulating seeds to stay longer. We also discuss a system design to show the feasibility of multi-torrent collaboration.
432 citations
••
TL;DR: This paper analytically evaluating the two main types of FFR deployments - Strict FFR and Soft Frequency Reuse - using a Poisson point process to model the base station locations and observes that FFR provides an increase in the sum-rate as well as the well-known benefit of improved coverage for cell-edge users.
Abstract: Fractional frequency reuse (FFR) is an interference management technique well-suited to OFDMA-based cellular networks wherein the bandwidth of the cells is partitioned into regions with different frequency reuse factors. To date, FFR techniques have been typically been evaluated through system-level simulations using a hexagonal grid for the base station locations. This paper instead focuses on analytically evaluating the two main types of FFR deployments - Strict FFR and Soft Frequency Reuse (SFR) - using a Poisson point process to model the base station locations. The results are compared with the standard grid model and an actual urban deployment. Under reasonable special cases for modern cellular networks, our results reduce to simple closed-form expressions, which provide insight into system design guidelines and the relative merits of Strict FFR, SFR, universal reuse, and fixed frequency reuse. Finally, a SINR-proportional resource allocation strategy is proposed based on the analytical expressions and we observe that FFR provides an increase in the sum-rate as well as the well-known benefit of improved coverage for cell-edge users.
432 citations
•
27 Jul 1997TL;DR: This work presents two statistical measures of the local search process that allow one to quickly find the optimal noise settings, and applies these principles to the problem of evaluating new search heuristics, and discovered two promising new strategies.
Abstract: It is well known that the performance of a stochastic local search procedure depends upon the setting of its noise parameter, and that the optimal setting varies with the problem distribution. It is therefore desirable to develop general priniciples for tuning the procedures. We present two statistical measures of the local search process that allow one to quickly find the optimal noise settings. These properties are independent of the fine details of the local search strategies, and appear to be relatively independent of the structure of the problem domains. We applied these principles to the problem of evaluating new search heuristics, and discovered two promising new strategies.
431 citations
••
TL;DR: In this article, the electronic wavefunctions of small crystallites are discussed within the effective mass approximation, and luminescence is observed from trapped carriers that may be in localized surface states.
Abstract: Semiconductor crystallites of characteristic dimension \sim20-100 A can be made by precipitation in liquids and dielectrics. These crystallites have bulk-like internal lattices. The optical spectra show partially resolved discrete features that result from carrier spatial confinement in three dimensions. Spectral shifts of more than 1 eV are observed. The electronic wavefunctions of small crystallites are discussed within the effective mass approximation. The pattern of discrete hole states is qualitatively different in small crystallites than in slab superlattices. In small CdS crystallites, luminescence is observed from trapped carriers that may be in localized surface states. The recombination emission is strongly coupled to crystallite phonons.
429 citations
Authors
Showing all 1881 results
Name | H-index | Papers | Citations |
---|---|---|---|
Yoshua Bengio | 202 | 1033 | 420313 |
Scott Shenker | 150 | 454 | 118017 |
Paul Shala Henry | 137 | 318 | 35971 |
Peter Stone | 130 | 1229 | 79713 |
Yann LeCun | 121 | 369 | 171211 |
Louis E. Brus | 113 | 347 | 63052 |
Jennifer Rexford | 102 | 394 | 45277 |
Andreas F. Molisch | 96 | 777 | 47530 |
Vern Paxson | 93 | 267 | 48382 |
Lorrie Faith Cranor | 92 | 326 | 28728 |
Ward Whitt | 89 | 424 | 29938 |
Lawrence R. Rabiner | 88 | 378 | 70445 |
Thomas E. Graedel | 86 | 348 | 27860 |
William W. Cohen | 85 | 384 | 31495 |
Michael K. Reiter | 84 | 380 | 30267 |