• Title/Summary/Keyword: Queuing theory

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A Multi-Class Task Scheduling Strategy for Heterogeneous Distributed Computing Systems

  • El-Zoghdy, S.F.;Ghoneim, Ahmed
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.10 no.1
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    • pp.117-135
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    • 2016
  • Performance enhancement is one of the most important issues in high performance distributed computing systems. In such computing systems, online users submit their jobs anytime and anywhere to a set of dynamic resources. Jobs arrival and processes execution times are stochastic. The performance of a distributed computing system can be improved by using an effective load balancing strategy to redistribute the user tasks among computing resources for efficient utilization. This paper presents a multi-class load balancing strategy that balances different classes of user tasks on multiple heterogeneous computing nodes to minimize the per-class mean response time. For a wide range of system parameters, the performance of the proposed multi-class load balancing strategy is compared with that of the random distribution load balancing, and uniform distribution load balancing strategies using simulation. The results show that, the proposed strategy outperforms the other two studied strategies in terms of average task response time, and average computing nodes utilization.

Optimal Design of Silo System for Drying and Storage of Grains (I)-Simulation Modeling with SLAMSYSTEM

  • Chung, Jong-Hoon
    • Proceedings of the Korean Society for Agricultural Machinery Conference
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    • 1993.10a
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    • pp.952-965
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    • 1993
  • A simulation modeling is necessary for the optimal design of a rice processing plant, which consists of a facility (a silo system) of rice drying and storage and a rice mill plant. In a rice processing plant, the production scheduling and the decision on capcity of each unit based on a queuing theory is very important and difficult. In this study a process-oriented simulation model was developed for the design of a rice drying and storage system with SLAMSYSTEM. The simulation model is capable of simulating virtually all the processing activities and provides work schedules which minimize total processing time , mean flow time and bottleneck of the plant system and estimate drying time for a batch in a drying silo. Model results were used for determination the size and capacity of each processing unit and for analyzing the performance of the plant . The developed model was actually applied to construct a grain silo system for rice drying and storage.

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Evaluation of Packet Loss Rate in Optical Burst Switching equipped with Optic Delay Lines Buffer

  • To, Hoang-Linh;Bui, Dang-Quang;Hwang, Won-Joo
    • Proceedings of the Korea Multimedia Society Conference
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    • 2012.05a
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    • pp.166-167
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    • 2012
  • High packet loss rate and impatience of messages passing through optical switches are essential characteristics in Optical Burst Switching system equipped with Optic Delay Lines buffer, which have not been solved efficiently yet by current existing models. In order to capture both effects, this paper introduces an analytical model from the viewpoint of classical queuing theory with impatient customers. We then apply it to evaluate and compare two wavelength-sharing cases, (1) all delay lines share a common wavelength resource and (2) each wavelength is associated with a number of delay lines. Our numerical results suggest to implement the first case because of lower packet loss rate for a fairly broad range of traffic load.

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A Study on Applied Orientations of Management Science Technique in Police Audit Planning Process (경찰감사 기획과정시 관리과학기법 응용방안)

  • Kim, Jeong-Heon;Song, Keon-Sup
    • Korean Security Journal
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    • no.5
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    • pp.109-130
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    • 2002
  • As proceeding Munmin and Kukmin's government, it is to bring in regionalism of genernal public administration and police administration, specialization, efficiency issue, demand inventing of audit technique to meet this trends. Especially, according to supporting qualitative improvement of the audit, its environment faced that orienting performance audit emphasis on not the legality but the efficiency more systematic and scientific theory or technique. In order to attain police audit's efficiency through performance audit, this study discussed that scientific management techniques should be applied police audit. Accordingly, the primary purpose of this study is to apply public audit to scientific management technique, bring to light limits in public sector(especially, police sector). To be efficiency audit(namely, performance audit), 1) OR techniques are explained linear programming, network modeling, PERT/CPM, queuing matrix model, simulation, 2) Statistical analysis methods are argued delphi technique, data envelopment analysis(DEA), analytic hierarchical process(AHP), time series analysis models etc.

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Maximum penalized likelihood estimation for a stress-strength reliability model using complete and incomplete data

  • Hassan, Marwa Khalil
    • Communications for Statistical Applications and Methods
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    • v.25 no.4
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    • pp.355-371
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    • 2018
  • The two parameter negative exponential distribution has many practical applications in queuing theory such as the service times of agents in system, the time it takes before your next telephone call, the time until a radioactive practical decays, the distance between mutations on a DNA strand, and the extreme values of annual snowfall or rainfall; consequently, has many applications in reliability systems. This paper considers an estimation problem of stress-strength model with two parameter negative parameter exponential distribution. We introduce a maximum penalized likelihood method, Bayes estimator using Lindley approximation to estimate stress-strength model and compare the proposed estimators with regular maximum likelihood estimator for complete data. We also introduce a maximum penalized likelihood method, Bayes estimator using a Markov chain Mote Carlo technique for incomplete data. A Monte Carlo simulation study is performed to compare stress-strength model estimates. Real data is used as a practical application of the proposed model.

A Study for a Methodology to Analyze Container Delays versus Security (보안대비 컨테이너 지연분석을 위한 방법론적 연구)

  • Yoon, Dae-Gwun
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.13 no.1 s.28
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    • pp.47-54
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    • 2007
  • After September 11, 2001, the United State's Customs and Border Protection (CBP) has set up inspection stations in seaport terminals. The inspection station, however, may directly and indirectly affect delay time in the seaports, increasing by especially high and severe level of security. This paper studies for a methodology to analyze container delays versus security incurring by the various layouts of the inspection station in the United States.

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Fitting acyclic phase-type distributions by orthogonal distance

  • Pulungan, Reza;Hermanns, Holger
    • Advances in Computational Design
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    • v.7 no.1
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    • pp.37-56
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    • 2022
  • Phase-type distributions are the distributions of the time to absorption in finite and absorbing Markov chains. They generalize, while at the same time, retain the tractability of the exponential distributions and their family. They are widely used as stochastic models from queuing theory, reliability, dependability, and forecasting, to computer networks, security, and computational design. The ability to fit phase-type distributions to intractable or empirical distributions is, therefore, highly desirable for many practical purposes. Many methods and tools currently exist for this fitting problem. In this paper, we present the results of our investigation on using orthogonal-distance fitting as a method for fitting phase-type distributions, together with a comparison to the currently existing fitting methods and tools.

The Performance Analysis of Distributed Reorder Buffer in Superscalar Processor using Analytical Model (해석적 모델을 이용한 분산된 리오더 버퍼 슈퍼스칼라 프로세서의 성능분석)

  • Yoon, Wan-Oh;Shin, Kwang-Sik;Kim, Kyeong-Seob;Lee, Yun-Sub;Choi, Sang-Bang
    • Journal of the Institute of Electronics Engineers of Korea SD
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    • v.45 no.12
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    • pp.73-82
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    • 2008
  • There are several approaches for reducing the ROB(Reorder Buffer) complexity in processors. The one technique that makes the simplest ROB ports relies on a distributed implementation that spreads the centralized ROB structure across the functional units(FUs). Each distributed buffers are decided on the size of them by workload of the functional units. The performance of the processor depends on the size of distributed ROB. However, most of previous works have depended on the simulation results to decide the optimsize of distributed ROB. In this Paper, we use an analytical model based on the M/M/1 Queuing theory to determine the optimum size of each distributed ROB. Our schemes are evaluated by using the simulation performed by the CPU2000 benchmarks. We are able to choose the optimum size of distributed ROB showing the 99.2% performance compared with existing superscalar processors. We can save 82% hardware resources in ports and reduce more than 30% of delay when ROB and distributed ROB proposed in this paper are designed by HDL.

An Exposed-Terminal-Eliminated Dual-Channel MAC Protocol for Exploiting Concurrent Transmissions in Multihop Wireless Networks

  • Liu, Kai;Zhang, Yupeng;Liu, Feng
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.8 no.3
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    • pp.778-798
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    • 2014
  • This paper proposes a novel exposed-terminal-eliminated medium access control (ETE-MAC) protocol by combining channel reservation, collision avoidance and concurrent transmissions to improve multi-access performance of the multihop wireless networks. Based on the proposed slot scheduling scheme, each node senses the control channel (CCH) or the data channel (DCH) to accurately determine whether it can send or receive the corresponding packets without collisions. Slot reservation on the CCH can be simultaneously executed with data packet transmissions on the DCH. Therefore, it resolves the hidden-terminal type and the exposed-terminal type problems efficiently, and obtains more spatial reuse of channel resources. Concurrent packet transmissions without extra network overheads are maximized. An analytical model combining Markov model and M/G/1 queuing theory is proposed to analyze its performance. The performance comparison between analysis and simulation shows that the analytical model is highly accurate. Finally, simulation results show that, the proposed protocol obviously outperforms the link-directionality-based dual-channel MAC protocol (DCP) and WiFlex in terms of the network throughput and the average packet delay.

RFID Agent based User Mobility Support Mechanism for Secure Information Transmission (안전한 정보 전송을 위한 RFID 네트워크 에이전트 기반의 사용자 이동성 제공 방안)

  • Yun, Dong-Geun;Seo, Chang-Ho;Choi, Seong-Gon
    • The Journal of the Korea Contents Association
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    • v.10 no.10
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    • pp.45-53
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    • 2010
  • In this paper, we propose RFID network agent based user mobility support mechanism for secure information transmissions. When a user with RFID tag who enjoys service moves to different attachment points, the user mobility is supported to provide continuously service and the information can be securely transmitted. Although there is an existing study for providing user mobility, it has a problem which the handover latency time is long. To settle this problem, we present a scheme for minimizing handover latency time and compare handover latency time of existing and proposed scheme. We confirm that proposed mechanism has low latency time than existing mechanism by mathematical analysis using the queuing theory and show that proposed mechanism is more superior to the existing mechanism.