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A Randomized Algorithm for Two Servers on the Line

Yair Bartal, Marek Chrobak, Lawrence L Larmore
2000 Information and Computation  
Then we give a 155 78 -competitive algorithm for the (6, 3)-server problem on the real line. Our algorithm is  ...  This implies that one unbiased random bit is not sufficient to improve the ratio of 2 for the two-server problem.  ...  K FINAL COMMENTS We have presented a 155 78 -competitive randomized online algorithm for two servers on the real line.  ... 
doi:10.1006/inco.1999.2809 fatcat:q76iehd6vvb23ln5b6vdpr4cwi

A Randomized Algorithm for Two Servers on the Line (Extended Abstract) [chapter]

Yair Bartal, Marek Chrobak, Lawrence L. Larmore
1998 Lecture Notes in Computer Science  
Then we give a 155 78 -competitive algorithm for the (6; 3)-server problem on the real line. Our algorithm is simple and memoryless.  ...  We give a positive answer to this problem when the underlying metric space is a real line, by providing a randomized online algorithm for this case with competitive ratio at most 155 78 1:987.  ...  The main contribution of this paper is a randomized online algorithm for two servers on the line whose competitive ratio is at most 155 78 1:987.  ... 
doi:10.1007/3-540-68530-8_21 fatcat:6hm45wz4mzcyxhhehmwa65bqra

Competitive paging algorithms

Amos Fiat, Richard M Karp, Michael Luby, Lyle A McGeoch, Daniel D Sleator, Neal E Young
1991 Journal of Algorithms  
This paper introduces the marking algorithm, a simple randomized on-line algorithm for the paging problem, and gives a proof that its performance guarantee (competitive ratio) is O(log k).  ...  In contrast, no deterministic on-line algorithm can have a performance guarantee better than k.  ...  ACKNOWLEDGMENT The authors thank Jorge Stolfi and an anonymous referee for many helpful suggestions.  ... 
doi:10.1016/0196-6774(91)90041-v fatcat:p2xsfvlzhzhyrkhkrtnwyyezom

Competitive algorithms for the weighted server problem

Amos Fiat, Moty Ricklin
1994 Theoretical Computer Science  
Fiat, A. and M. Ricklin, Competitive algorithms for the weighted server problem, Theoretical Computer Science 130 (1994) 85-99.  ...  Acknowledgements We wish to thank Oded Goldreich for the excellent comments he gave to the extended abstract of this paper, presented at the 3rd ISTCS.  ...  We also wish to thank the two anonymous reviewers whose excellent work and efforts greatly helped us in improving this presentation.  ... 
doi:10.1016/0304-3975(94)90154-6 fatcat:ghd2czev2jc43cbi3cugzajnkm

EMULATION OF THE POX CONTROLLER AS A LOAD BALANCER

Sally A. Al-Hasnawi, Mahmood K. Ibrahem
2021 Iraqi Journal of Information & Communications Technology  
The following parts constitute two servers, four clients, a pox controller, and an open virtual switch.  ...  Abstract- The servers' nature of having bottleneck situations makes the load balancing one of the essential services in the networks, particularly with the users' increasing load.  ...  Weighted Round-Robin Algorithm The weight for server one equals 1, the weight for server two equals 2, and the weight for server three equals 3.  ... 
doi:10.31987/ijict.4.2.138 fatcat:yveylk4cjrayngmd7f2ieq355e

R–LINE: A better randomized 2-server algorithm on the line

Lucas Bang, Wolfgang Bein, Lawrence L. Larmore
2015 Theoretical Computer Science  
A randomized on-line algorithm is given for the 2-server problem on the line, with competitiveness less than 1.901 against the oblivious adversary.  ...  This improves the previously best known competitiveness of 155 78 ≈ 1.987 for the problem. The algorithm uses a new approach and defines a potential in terms of isolation indices from T-theory.  ...  Acknowledgement Part of the work of author Wolfgang Bein was supported by National Science Foundation grant IIA 1427584.  ... 
doi:10.1016/j.tcs.2015.08.043 fatcat:uyn2nh2id5cevdin5sqlugrpou

R–LINE: A Better Randomized 2-Server Algorithm on the Line [chapter]

Lucas Bang, Wolfgang Bein, Lawrence L. Larmore
2013 Lecture Notes in Computer Science  
A randomized on-line algorithm is given for the 2-server problem on the line, with competitiveness less than 1.901 against the oblivious adversary.  ...  This improves the previously best known competitiveness of 155 78 ≈ 1.987 for the problem. The algorithm uses a new approach and defines a potential in terms of isolation indices from T-theory.  ...  Acknowledgement Part of the work of author Wolfgang Bein was supported by National Science Foundation grant IIA 1427584.  ... 
doi:10.1007/978-3-642-38016-7_11 fatcat:mllli7t52fdrrnjwk3xfxady4i

Page 1283 of Mathematical Reviews Vol. , Issue 2001B [page]

2001 Mathematical Reviews  
algorithm for two servers on the line.  ...  Then we give a ve competitive algorithm for the (6,3)-server problem on the real line. Our algorithm is simple and memoryless.  ... 

Competitive k-server algorithms

Amos Fiat, Yuval Rabani, Yiftach Ravid
1994 Journal of computer and system sciences (Print)  
This settles the k-server conjecture up to the competitive ratio, The best previous result for general metric spaces was a three-server randomized competitive algorithm and a nonconstructive proof that  ...  a deterministic three-server competitive algorithm exists.  ...  The immediate problem is that on-line algorithms are incomparable; on-line algorithm A may be better than on-line algorithm B for one sequence of events and algorithm B may be better than A for another  ... 
doi:10.1016/s0022-0000(05)80060-1 fatcat:ubdqin3jq5eqtptdlfampocfca

A strongly competitive randomized paging algorithm

Lyle A. McGeoch, Daniel D. Sleator
1991 Algorithmica  
We develop the partitioning algorithm, a randomized on-line algorithm for the paging problem. We prove that its expected cost on any sequence of requests is within a factor of if* of optimum.  ...  (Hk is the k th harmonic number, which is about ln(fc).) No on-line algorithm can perform better by this measure. Our result improves by a factor of two the best previous algorithm.  ...  (The cost of OPT actually equals D{o), because OPT has no other costs.) • An On-Line Algorithm We can now describe the partitioning algorithm, a randomized ^-competitive algorithm for the uniform fc-server  ... 
doi:10.1007/bf01759073 fatcat:bgsbvzsktrfxdo7qvclmq4b54q

Random walks on weighted graphs, and applications to on-line algorithms

D. Coppersmith, P. Doyle, P. Raghavan, M. Snir
1990 Proceedings of the twenty-second annual ACM symposium on Theory of computing - STOC '90  
We develop a theory for the synthesis of such walks, and employ it to design competitive on-line algorithms.  ...  We study the design and analysis of randomized on-line algorithms. We show that this problem is closely related to the synthesis of random walks on graphs with positive real costs on their edges.  ...  Acknowledgements We thank Allan Borodin and Gil Strang for their helpful comments and suggestions.  ... 
doi:10.1145/100216.100266 dblp:conf/stoc/CoppersmithDRS90 fatcat:sumfy2hprzbyjmc2qobtfzpz5m

Efficient Deployment of Web Service Workflows

Konstantinos Stamkopoulos, Evaggelia Pitoura, Panos Vassiliadis
2007 2007 IEEE 23rd International Conference on Data Engineering Workshop  
We study different topologies for the workflow structure and the server connectivity and propose a suite of greedy algorithms for each combination.  ...  Efficiency is measured in terms of two cost functions that concern the execution time of the workflow and the fairness of the load distribution among the servers.  ...  This research was co-funded by the European Union in the framework of the program "Pythagoras IΙ" of the "Operational Program for Education and Initial Vocational Training" of the 3rd Community Support  ... 
doi:10.1109/icdew.2007.4401012 dblp:conf/icde/StamkopoulosPV07 fatcat:bua4wmrzwfbypf4bgfhezz425u

Random walks on weighted graphs and applications to on-line algorithms

Don Coppersmith, Peter Doyle, Prabhakar Raghavan, Marc Snir
1993 Journal of the ACM  
We develop a theory for the synthesis of such w alks, and employ it to design competitive on-line algorithms.  ...  We study the design and analysis of randomized on-line algorithms. We show that this problem is closely related to the synthesis of random walks on graphs with positive real costs on their edges.  ...  Acknowledgements We thank Allan Borodin and Gil Strang for their helpful comments and suggestions.  ... 
doi:10.1145/174130.174131 fatcat:eww5qvq3a5eszgtgpolhiurmym

A Collection of Lower Bounds for Online Matching on the Line [chapter]

Antonios Antoniadis, Carsten Fischer, Andreas Tönnis
2018 Lecture Notes in Computer Science  
The distance metric between any two points in R ∪ S is a line metric and the objective for the online algorithm is to minimize the sum of distances between matched server-request pairs.  ...  In the online matching on the line problem, the task is to match a set of requests R online to a given set of servers S.  ...  Lines show to which server each request is matched to. For a clearer representation we will often arrange servers and requests on different lines.  ... 
doi:10.1007/978-3-319-77404-6_5 fatcat:qmscmph4f5dmnleloysxynbk7y

Page 3328 of Mathematical Reviews Vol. , Issue 93f [page]

1993 Mathematical Reviews  
For the so-called k-server problem, the authors present two formalizations of on-line algorithms: on-line games and metrical service systems.  ...  The main part of the paper deals with two new algorithms for the k-server preblem. In particular, it is proved that both algorithms are 2-competitive for k = 2.  ... 
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