Fourth International Conference on the Quantitative Evaluation of Systems (QEST 2007)最新文献

A business-oriented load dispatching framework for online auction sites 面向业务的在线拍卖站点负载调度框架

Fourth International Conference on the Quantitative Evaluation of Systems (QEST 2007) Pub Date : 2007-09-17 DOI: 10.1109/QEST.2007.28

D. Menascé, V. Akula

{"title":"A business-oriented load dispatching framework for online auction sites","authors":"D. Menascé, V. Akula","doi":"10.1109/QEST.2007.28","DOIUrl":"https://doi.org/10.1109/QEST.2007.28","url":null,"abstract":"Online auction sites have unique workloads and user behavior characteristics that do not exist in other e-commerce sites. Earlier studies by the authors identified i) significant changes in the workload depending on time of day and ii) the presence of heavy-tailed distributions involving bidder and seller behavior. Other studies indicate that a small fraction or power users, among millions of registered users, contribute to the majority of the site's revenue. Poor quality of service to power users may imply in loss of business and cause significant loss of revenue to an auction site. This problem could be mitigated by dedicating resources in an exclusive manner to this small group of users in order to improve the quality of service they receive. However, this approach can lead to i) under utilization of these dedicated resources and ii) overloading of resources allocated to regular users when the load from power users is low. In this paper, we propose a scheme whereby resources are primarily dedicated to power users, but regular users can take advantage of these dedicated resources when spare capacity is available. This paper provides a business-oriented framework for dispatching requests to the various servers of an online auction site. Our approach uses a controller that can dynamically shift the load to different types of servers as the workload changes. Experimental evaluation showed, among other things, that the total number of bids processed using a dynamic controller to allocate resources can be improved under heavy load conditions compared to using a load balancing technique that does not differentiate among users.","PeriodicalId":249627,"journal":{"name":"Fourth International Conference on the Quantitative Evaluation of Systems (QEST 2007)","volume":"112 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131089306","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: 6

Qualitative Logics and Equivalences for Probabilistic Systems 概率系统的定性逻辑和等价

Fourth International Conference on the Quantitative Evaluation of Systems (QEST 2007) Pub Date : 2007-09-17 DOI: 10.2168/LMCS-5(2:7)2009

L. D. Alfaro, K. Chatterjee, M. Faella, Axel Legay

{"title":"Qualitative Logics and Equivalences for Probabilistic Systems","authors":"L. D. Alfaro, K. Chatterjee, M. Faella, Axel Legay","doi":"10.2168/LMCS-5(2:7)2009","DOIUrl":"https://doi.org/10.2168/LMCS-5(2:7)2009","url":null,"abstract":"We present qualitative randomized CTL (QRCTL), a qualitative version of pCTL, for specifying properties of Markov decision processes (MDPs). QRCTL formulas can express the fact that certain temporal properties hold with probability 0 or 1, but they do not distinguish other probabilities values. We present a symbolic, polynomial time model-checking algorithm for QRCTL on MDPs. Then, we study the equivalence relation induced by QRCTL, called qualitative equivalence. We show that for finite alternating MDPs, where nondeterministic and probabilistic choice occur in different states, qualitative equivalence coincides with alternating bisimulation, and can thus be computed via efficient partition-refinement algorithms. Surprisingly, the result does not hold for non-alternating MDPs. Indeed, we show that no local partition refinement algorithm can compute qualitative equivalence on non-alternating MDPs. Finally, we consider QRCTL*, that is the \"star extension\" of QRCTL. We show that QRCTL and QRCTL* induce the same qualitative equivalence on alternating MDPs, while on non-alternating MDPs, the equivalence arising from QRCTL* can be strictly finer. We also provide a full characterization of the relation between qualitative equivalence, bisimulation, and alternating bisimulation, according to whether the MDPs are finite, and to whether their transition relations are finite-branching.","PeriodicalId":249627,"journal":{"name":"Fourth International Conference on the Quantitative Evaluation of Systems (QEST 2007)","volume":"25 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115434368","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: 12

A framework to design and solve Markov Decision Well-formed Net models 一个设计和求解马尔可夫决策良构网络模型的框架

Fourth International Conference on the Quantitative Evaluation of Systems (QEST 2007) Pub Date : 2007-09-17 DOI: 10.1109/QEST.2007.32

M. Beccuti, D. Raiteri, G. Franceschinis, S. Haddad

引用次数: 12

Probabilistic Model Checking Modulo Theories 概率模型检验模理论

Fourth International Conference on the Quantitative Evaluation of Systems (QEST 2007) Pub Date : 2007-09-17 DOI: 10.1109/QEST.2007.10

Björn Wachter, Lijun Zhang, H. Hermanns

引用次数: 52

Design of Experiments within the Mobius Modeling Environment Mobius建模环境下的实验设计

Fourth International Conference on the Quantitative Evaluation of Systems (QEST 2007) Pub Date : 2007-09-17 DOI: 10.1109/QEST.2007.36

T. Courtney, Shravan Gaonkar, M. McQuinn, Eric Rozier, W. Sanders, P. Webster

引用次数: 6

ProbDiVinE: A Parallel Qualitative LTL Model Checker ProbDiVinE:一个并行定性LTL模型检查器

Fourth International Conference on the Quantitative Evaluation of Systems (QEST 2007) Pub Date : 2007-09-17 DOI: 10.1109/QEST.2007.13

J. Barnat, L. Brim, I. Cerná, Milan Ceska, Jana Tumova

引用次数: 6

CUT : Combining stochastic ordering and censoring to bound steady-state rewards and first passage time CUT:结合随机排序和审查来约束稳态奖励和首次通过时间

Fourth International Conference on the Quantitative Evaluation of Systems (QEST 2007) Pub Date : 2007-09-17 DOI: 10.1109/QEST.2007.35

J. Fourneau, N. Pekergin, S. Younès

引用次数: 4

Interchange Formats for Performance Models: Experimentation and Ouput 性能模型的交换格式:实验和输出

Fourth International Conference on the Quantitative Evaluation of Systems (QEST 2007) Pub Date : 2007-09-17 DOI: 10.1109/QEST.2007.24

C. U. Smith, Catalina M. Lladó, R. Puigjaner, L. Williams

引用次数: 17

A Petri Net Model for Evaluating Packet Buffering Strategies in a Network Processor 网络处理器中数据包缓冲策略评估的Petri网模型

Fourth International Conference on the Quantitative Evaluation of Systems (QEST 2007) Pub Date : 2007-09-17 DOI: 10.1109/QEST.2007.29

C. GirishB., R. Govindarajan

{"title":"A Petri Net Model for Evaluating Packet Buffering Strategies in a Network Processor","authors":"C. GirishB., R. Govindarajan","doi":"10.1109/QEST.2007.29","DOIUrl":"https://doi.org/10.1109/QEST.2007.29","url":null,"abstract":"Previous studies have shown that buffering packets in DRAM is a performance bottleneck. In order to understand the impediments in accessing the DRAM, we developed a detailed Petri net model of IP forwarding application on IXP2400 that models the different levels of the memory hierarchy. The cell based interface used to receive and transmit packets in a network processor, leads to some small size DRAM accesses. Such narrow accesses to the DRAM expose the bank access latency, reducing the bandwidth that can be realized. With real traces up to 30% of the accesses are smaller than the cell size, resulting in 7.7% reduction in DRAM bandwidth. To overcome this problem, we propose buffering these small chunks of data in the on chip scratchpad memory. This scheme also exploits greater degree of parallelism between different levels of the memory hierarchy. Using real traces from the internet, we show that the transmit rate can be improved by an average of 21% over the base scheme without the use of additional hardware. Further, the impact of different traffic patterns on the network processor resources is studied. Under real traffic conditions, we show that the data bus which connects the off-chip packet buffer to the micro- engines, is the obstacle in achieving higher throughput.","PeriodicalId":249627,"journal":{"name":"Fourth International Conference on the Quantitative Evaluation of Systems (QEST 2007)","volume":"196 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126558289","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: 1

Symbolic Bisimulations for Probabilistic Systems 概率系统的符号双模拟

Fourth International Conference on the Quantitative Evaluation of Systems (QEST 2007) Pub Date : 2007-09-17 DOI: 10.1109/QEST.2007.11

Peng Wu, C. Palamidessi, Huimin Lin

引用次数: 25