Filters








25,729 Hits in 4.9 sec

OR-parallel theorem proving with random competition [chapter]

Wolfgang Ertel
Logic Programming and Automated Reasoning  
With random competition we propose a method for parallelizing backtracking search. We can prove high efficiency of random competition on highly parallel architectures with thousands of processors.  ...  OR-parallel search in general.  ...  The basic idea of random competition is to use a set of independent parallel processors, each of them executing a different randomized search strategy for proving a theorem.  ... 
doi:10.1007/bfb0013064 dblp:conf/lpar/Ertel92 fatcat:fvf4x4q7q5hqno7v4cdjgsczr4

Randomized algorithms for on-line scheduling problems: how low can't you go?

Leen Stougie, Arjen P.A. Vestjens
2002 Operations Research Letters  
Theorem 4.4 Any randomized algorithm for the on-line makespan problem on identical parallel machines has a competitive ratio against an oblivious adversary greater or equal to 4 -2V2.  ...  Theorem 4. 3 3 Any randomized algorithm for the on-line maximum delivery time problem on identical parallel machines has a competitive ratio against an oblivious adversary greater or equal to 1.265.  ... 
doi:10.1016/s0167-6377(01)00115-8 fatcat:7fdmz66ngjhsjccqmebpmjn4oq

A $$o(n)$$ -Competitive Deterministic Algorithm for Online Matching on a Line [chapter]

Antonios Antoniadis, Neal Barcelo, Michael Nugent, Kirk Pruhs, Michele Scquizzato
2015 Lecture Notes in Computer Science  
Online matching on a line involves matching an online stream of items of various sizes to stored items of various sizes, with the objective of minimizing the average discrepancy in size between matched  ...  The best previously known upper and lower bounds on the optimal deterministic competitive ratio are linear in the number of items, and constant, respectively.  ...  We note that, in a manner similar to that presented in Section 4, it is possible to extend the Parallel Cows algorithm for k-LCWA to OML directly and obtain an O p log 2 (3+ )−1 / -competitive algorithm  ... 
doi:10.1007/978-3-319-18263-6_2 fatcat:chcry2oecfbdzkvnhossx65mam

Page 7794 of Mathematical Reviews Vol. , Issue 95m [page]

1995 Mathematical Reviews  
The authors first prove two theorems, the pattern limit theorem and the collective limit theorem.  ...  In a similar way we prove that the competitive ratio for the randomized case is k’ = In(m) (up to an additive 1).  ... 

Lower bounds for on-line scheduling with precedence constraints on identical machines [chapter]

Leah Epstein
1998 Lecture Notes in Computer Science  
2=(m+1) on the competitive ratio of any randomized algorithm (with or without preemption). The lower bounds for the cases that preemption is allowed require arbitrarily long sequences.  ...  1=m on the competitive ratio of any deterministic algorithm (with or without preemption) and a lower bound of 2 ?  ...  We use the sequence from Theorem 2 with k = 1.  ... 
doi:10.1007/bfb0053966 fatcat:knvtij4r5zd7fei4r5xdgbpyqi

The matroid secretary problem for minor-closed classes and random matroids [article]

Tony Huynh, Peter Nelson
2019 arXiv   pre-print
We also note that for asymptotically almost all matroids, the matroid secretary algorithm that selects a random basis, ignoring weights, is (2+o(1))-competitive.  ...  We prove that for every proper minor-closed class M of matroids representable over a prime field, there exists a constant-competitive matroid secretary algorithm for the matroids in M.  ...  Finally, in Section 8, we prove our results on random matroids.  ... 
arXiv:1603.06822v5 fatcat:q3dfe33ctfdizdadd2qoyhruby

Matroid Secretary Problem in the Random Assignment Model [article]

José A. Soto
2010 arXiv   pre-print
Our main result is the first constant competitive algorithm for the matroid secretary problem in the random assignment model. This solves an open question of Babaioff et al.  ...  When an element is revealed, the algorithm learns its weight and decides whether or not to select it under the restriction that the selected elements form an independent set in the matroid.  ...  To prove Theorem 4.3, we compare the weight of the set ALG returned by Algorithm 2 with the optimum of the partition matroid P defined above.  ... 
arXiv:1007.2152v1 fatcat:eccprmcek5dcfjmfawhlamxuju

Online Scheduling of Task Graphs on Heterogeneous Platforms

Louis-Claude Canon, Loris Marchal, Bertrand Simon, Frederic Vivien
2019 IEEE Transactions on Parallel and Distributed Systems  
We prove that no online algorithm can have a competitive ratio smaller than m/k.  ...  We also study how adding flexibility on task processing, such as task migration or spoliation, or increasing the knowledge of the scheduler by providing it with information on the task graph, influences  ...  Theorem 3. The lower bounds proved in Theorems 1 and 2 on the competitive ratio of deterministic algorithms not using migration hold for randomized algorithms, divided by a factor 2. Proof.  ... 
doi:10.1109/tpds.2019.2942909 fatcat:glyainqq6rf4vn37zqhkxwlxca

Online Routing in Triangulations

Prosenjit Bose, Pat Morin
2004 SIAM journal on computing (Print)  
Our results include (1) two deterministic memoryless routing algorithms, one that works for all Delaunay triangulations and the other that works for all regular triangulations; (2) a randomized memoryless  ...  memory algorithm that works for all convex subdivisions; (4) an O(1) memory algorithm that approximates the shortest path in Delaunay triangulations; and (5) theoretical and experimental results on the competitiveness  ...  We refer to the combination of the Voronoi routing algorithm with this parallel search algorithm as the parallel Voronoi routing algorithm. Theorem 3.6.  ... 
doi:10.1137/s0097539700369387 fatcat:zqgjya3ho5fwth2rtfnob2nsfi

Matroid Secretary Problem in the Random Assignment Model [chapter]

José A. Soto
2011 Proceedings of the Twenty-Second Annual ACM-SIAM Symposium on Discrete Algorithms  
As the main result of this article, we devise the first constant competitive algorithm for the model in which both the order and the weight assignment are selected uniformly at random, achieving a competitive  ...  for the stronger random-assignment adversarial-order model.  ...  Every color is successful with probability at least p(1−p)q(1−q). Before proving this proposition, let's use it to prove the main theorem of this section. Theorem 3.6.  ... 
doi:10.1137/1.9781611973082.97 dblp:conf/soda/Soto11 fatcat:wvy3s4seqfb5zop52ayutdncm4

Matroid Secretary Problem in the Random-Assignment Model

José A. Soto
2013 SIAM journal on computing (Print)  
As the main result of this article, we devise the first constant competitive algorithm for the model in which both the order and the weight assignment are selected uniformly at random, achieving a competitive  ...  for the stronger random-assignment adversarial-order model.  ...  Every color is successful with probability at least p(1−p)q(1−q). Before proving this proposition, let's use it to prove the main theorem of this section. Theorem 3.6.  ... 
doi:10.1137/110852061 fatcat:y2hd6hftr5enfccc2uy55g2yiy

On-line scheduling to minimize max flow time: an optimal preemptive algorithm

Christoph Ambühl, Monaldo Mastrolilli
2005 Operations Research Letters  
Moreover, when the algorithm must schedule jobs one by one in the order they are released, we prove that there is no randomized on-line algorithm with a better competitive ratio.  ...  We derive an on-line algorithm with competitive ratio 2 − 1/m.  ...  We prove the theorem by giving a lower bound of 2 − 1/m − ε on the competitive ratio, for any fixed ε > 0.  ... 
doi:10.1016/j.orl.2004.10.006 fatcat:tlxij7utune3ljeigezxziueiu

Online Routing in Triangulations [chapter]

Prosenjit Bose, Pat Morin
1999 Lecture Notes in Computer Science  
Our results include (1) two deterministic memoryless routing algorithms, one that works for all Delaunay triangulations and the other that works for all regular triangulations, (2) a randomized memoryless  ...  memory algorithm that works for all convex subdivisions, (4) an O(1) memory algorithm that approximates the shortest path in Delaunay triangulations, and (5) theoretical and experimental results on the competitiveness  ...  They also describes an O(1) memory routing algorithm that is not defeated by any connected planar graph, thus proving a stronger result than Theorem 2.7.  ... 
doi:10.1007/3-540-46632-0_12 fatcat:sfmqahv6lrbcxk5af7kqca3t7y

Witness indistinguishable and witness hiding protocols

U. Feige, A. Shamir
1990 Proceedings of the twenty-second annual ACM symposium on Theory of computing - STOC '90  
Proof (sketch): Consider polynomially many protocols carried out concurrently (sequentially, in parallel, or with interleaved steps).  ...  The probability space is that of the random choices of c~ together with P's random coin tosses. <~ Theorem 5.2: Any NIZK proof system is also a NIWI proof system.  ... 
doi:10.1145/100216.100272 dblp:conf/stoc/FeigeS90 fatcat:zsg4g67tzrbjpfekhg2lt6n2ui

LP-Based Online Scheduling: From Single to Parallel Machines [chapter]

José R. Correa, Michael R. Wagner
2005 Lecture Notes in Computer Science  
Additionally, we show how to combine randomization techniques with the linear programming approach to obtain randomized algorithms for both versions of the problem with competitive ratio strictly smaller  ...  Specifically, we look at deterministic and randomized algorithms for the problem of scheduling jobs with release dates on identical parallel machines, to minimize the sum of weighted completion times:  ...  We specially thank another anonymous referee for pointing out an error in a preliminary version of Theorem 5.3.  ... 
doi:10.1007/11496915_15 fatcat:x44sqaggxje4vg2xu6futo6koi
« Previous Showing results 1 — 15 out of 25,729 results