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NUMERICAL SIMULATION OF FLOWS IN A CYCLONE CHAMBER WITH DIFFERENT CONDITIONS OF AIR INLET AND OUTLET

JOURNAL OF ENGINEERING PHYSICS AND THERMOPHYSICS 2014年第5期87卷 1022-1029页

作者： Pitsukha, E. A. Beloozersk Power Mech Plant Joint Stock Co 1 Zavodskaya Str Beloozersk 225215 BELARUS

A numerical investigation of flows in a cyclone chamber has been carried out at the fraction of bottom blast f = 0- 0.5, at the values of the dimensionless pinch diameter d(out)/D = 0.7 with different locations and confi gurations of nozzles for air intake. In the simulation of swirling fl ows, the well-known k-epsilon and k-omega. turbulence models, as well as the laminar flow model, were used. A satisfactory agreement between the results of numerical simulation and experimental data at d(out)/D = 0.5-0.7 is obtained. For a chamber with a relative pinch diameter d(out)/D = 0.3 the calculated flow parameters differ substantially from experimental values.

关键词： cyclone chamber turbulence model computational grid tangential velocity longitudinal velocity bottom blast total pressure

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Performance-Driven Load Balancing with a Primary-Backup Approach for computational grids with Low Communication Cost and Replication Cost

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IEEE TRANSACTIONS ON COMPUTERS 2013年第5期62卷 990-1003页

作者： Balasangameshwara, Jasma Raju, Nedunchezhian PES Inst Technol Dept Informat Sci & Engn Bangalore 560085 Karnataka India Sri Ramakrishna Engn Coll Dept Informat Technol Coimbatore 641022 Tamil Nadu India

computational grids provide a massive source of processing power, providing the means to support processor intensive applications. The strong burstiness and unpredictability of the available resources raise the need to make applications robust against the dynamics of grid environment. The two main techniques that are most suitable to cope with the dynamic nature of the grid are load balancing and job replication. In this work, we develop a load-balancing algorithm by juxtaposes the strong points of neighbor-based and cluster-based load-balancing methods. We then integrate the proposed load-balancing approach with fault-tolerant scheduling namely MinRC and develop a performance-driven fault-tolerant load-balancing algorithm or PD_MinRC for independent jobs. In order to improve system flexibility, reliability, and save system resource, PD_MinRC employs passive replication scheme. Our main objective is to arrive at job assignments that could achieve minimum response time, maximum resource utilization, and a well-balanced load across all the resources involved in a grid. Experiments were conducted to show the applicability of PD_MinRC. One advantage of our approach is the relatively low overhead and robust performance against resource failures and inaccuracies in performance prediction information.

关键词： computational grid load balancing fault tolerance job scheduling

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grid Architecture for Scheduling and Load Balancing - An Assessment

Grid Architecture for Scheduling and Load Balancing - An Ass...

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International Conference on Information Communication and Embedded Systems (ICICES)

作者： Priya, B. Gnanasekaran, T. Sri Sai Ram Engn Coll MCA Dept Chennai Tamil Nadu India RMK Coll Engn & Technol Dept IT Chennai Tamil Nadu India

ISBN: (纸本)9781479938346

grid Computing emerged as a wide scale distributed system to offer dynamic coordinated resources sharing and high performance computing. grid coordinates the resources that are not subject to centralized control. It uses standard open, general purpose protocols and its interfaces. grid delivers non-trivial qualities of service such as the response time, throughput, availability and security. grid computing is being adopted in various areas from academic, industry research to government use. grids are becoming platforms for high performance and distributed computing. grid computing is the next generation IT infrastructure that promises to transform the way organizations and individuals compute, communicate and collaborate. The goal of grid computing is to create the illusion of a simple but large and powerful self-managing virtual computer out of a large collection of connected heterogeneous systems sharing various combinations of resources. Scheduling is a set of rules and policies that control the order by which various jobs are executed in a system. Load balancing deals with the way by which the various tasks are assigned to the resources thereby improving the system performance. Scheduling of various tasks to the resources in a grid environment is an active research area. Resources are dynamic in nature so the load of resources varies with change in configuration of grid so the Load Balancing of the tasks in a grid environment can significantly influence grid's performance. A poor scheduling policy may leave many processors idle while a clever one may consume an unduly large portion of the total CPU cycles. In order to utilize the resources efficiently and to satisfy the requirement of the users, several scheduling algorithms have been proposed by researchers for various applications. This paper deals with the overview of the grid Computing concepts, the various standards associated with it, the terms associated with scheduling and load balancing and the tools as

关键词： computational grid grid Scheduler (GS) Load balancing OGSA XML

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A distributed framework for energy-efficient lightpaths in computational grids

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JOURNAL OF HIGH SPEED NETWORKS 2013年第1期19卷 1-18页

作者： Tafani, Daniele Kantarci, Burak Mouftah, Hussein McArdle, Conor Barry, Liam Dublin City Univ Dublin Ireland Univ Ottawa Ottawa ON Canada

Over the past decade, the ever-increasing energy demands of IT infrastructures have posed significant challenges for the research community in terms of reducing their total power consumption and minimizing their environmental impact. Optical communication networks are envisioned to be promising candidates to help preventing this problem affecting the Internet backbone, as well as for distributed applications such as computational grids. In this paper, we propose an adaptive and distributed scheme for the establishment of energy-efficient lightpaths in computational grids. The grid is deployed over an optical circuit-switched backbone network, defining an optical grid network. Each node of the backbone network maintains two different dynamic thresholds values and estimates the changes in network performance by evaluating the moving average of the total wavelength channel occupancy on all its input/output links. The nodes have the ability of reducing the energy consumption by entering into an Energy Saving Mode (ESM) on the basis of a comparison between their channel occupancy and the thresholds. Furthermore, we extend our framework by allowing the thresholds to be dynamically adapted depending on the network performance in terms of blocking probability. We show that the proposed method achieves considerable energy savings when compared to a normal energy-unaware operational mode and still allows to maintain an acceptable level of network performance in terms of blocking probability and end-to-end delay. Numerical results are obtained with a Java event-driven simulator of two different optical network topologies.

关键词： Optical grid network computational grid energy efficiency optical lightpath dynamic sleep mode

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New Fault Tolerant Scheduling Algorithm Implemented using Check Pointing in grid Computing Environment

New Fault Tolerant Scheduling Algorithm Implemented using Ch...

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International Conference on Optimization, Reliabilty, and Information Technology (ICROIT)

作者： Jain, Sumant Chaudhary, Jyoti MDU Univ Rohtak Haryana India

ISBN: (纸本)9781479929955

Job checkpointing is a common technique for providing fault tolerance in grid computing environment. The effectiveness of checkpointing depends on the selection of the number of checkpoint interval and the duration of checkpoint interval. Fluctuating checkpointing interval can delay job execution. In this paper, a new fault-tolerant job scheduling algorithm based on checkpointing technique is presented and evaluated. While scheduling the job, the system uses RFOH to have both average failure time and failure rate of grid resources combined with resources latency to generate scheduling decisions. In RFOH, the system uses the tendency of failure of the previously assigned resources to calculate the checkpoint interval for each job. Various simulated experiments are conducted to quantify the performance of the proposed system in the grid simulator. Experiments have shown that the proposed system can considerably improve latency.

关键词： Check pointing computational grid scheduling fault rate latency RFOH

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A Real-Time Intrusion Detection and Protection System at System Call Level under the Assistance of a grid

A Real-Time Intrusion Detection and Protection System at Sys...

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2nd IFIP TC5/8 International Conference on ICT-EurAsia

作者： Leu, Fang-Yie Hsiao, Yi-Ting Yim, Kangbin You, Ilsun Tunghai Univ Dept Comp Sci Taichung 40704 Taiwan Soonchunyang Univ Soonchunhyang South Korea Korean Bible Univ Seoul South Korea

ISBN: (纸本)9783642550324;9783642550317

In this paper, we propose a security system, named the Intrusion Detection and Protection System (IDPS for short) at system call level, which creates personal profiles for users to keep track of their usage habits as the forensic features, and determines whether a legally login users is the owner of the account or not by comparing his/her current computer usage behaviors with the user's computer usage habits collected in the account holder's personal profile. The IDPS uses a local computational grid to detect malicious behaviors in a real-time manner. Our experimental results show that the IDPS's user identification accuracy is 93%, the accuracy on detecting its internal malicious attempts is up to 99% and the response time is less than 0.45 sec., implying that it can prevent a protected system from internal attacks effectively and efficiently.

关键词： Forensic Features Intrusion Detection and Protection Data Mining Identifying Malicious behaviors computational grid

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Utility-driven solution for optimal resource allocation in computational grid

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COMPUTER LANGUAGES SYSTEMS & STRUCTURES 2009年第4期35卷 406-421页

作者： Li, Zhi-jie Cheng, Chun-tian Huang, Fei-xue Dalian Univ Technol Inst Hydropower Syst & Hydroinformat Dalian 116024 Liaoning Peoples R China Dalian Univ Technol Dept Comp Sci & Engn Dalian 116024 Liaoning Peoples R China Dalian Nationalities Univ Res Inst Nonlinear Informat Technol Dalian 116600 Peoples R China Dalian Univ Technol Dept Econ Dalian 116024 Liaoning Peoples R China

Optimal resource allocation is a complex undertaking due to large-scale heterogeneity present in computational grid. Traditionally, the decision based on certain cost functions has been used in allocating grid resource as a standard method that does not take resource access cost into consideration. In this paper, the utility function is presented as a promising method for grid resource allocation. To tackle the issue of heterogeneous demand, the user's preference is represented by utility function, which is driven by a user-centric scheme rather than system-centric parameters adopted by cost functions. The goal of each grid user is to maximize its own utility under different constraints. In order to allocate a common resource to multiple bidding users. the optimal solution is achieved by searching the equilibrium point of resource price such that the total demand fora resource exactly equals the total amount available to generate a set of optimal user bids. The experiments run on a Java-based discrete-event grid simulation toolkit called gridSim are made to study characteristics of the utility-driven resource allocation strategy under different constraints. Results show that utility optimization under budget constraint outperforms deadline constraint in terms of time spent, whereas deadline constraint outperforms budget constraint in terms of cost spent. The conclusion indicates that the utility-driven method is a very potential candidate for the optimal resource allocation in computational grid. (C) 2008 Elsevier Ltd. All rights reserved.

关键词： Resource allocation Utility function computational grid gridSim

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Ga Based Scheduling Model for computational grid to Minimize Turnaround Time

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INTERNATIONAL JOURNAL OF grid AND HIGH PERFORMANCE COMPUTING 2009年第4期1卷 70-90页

作者： Raza, Zahid Vidyarthi, Deo P. Jawaharlal Nehru Univ Sch Comp & Syst Sci New Delhi India

Scheduling on distributed systems is an NP hard problem and grid being a wide heterogeneous expandable system makes scheduling even a tougher job. Genetic algorithm, based on natural selection and evolution has gained popularity in recent times because of its effectiveness in handling optimization problems. In this article, a job-scheduling model for a computational grid with the objective of minimizing the turnaround time using genetic algorithm is proposed. The model evaluates various clusters in the grid to find the most suitable one with minimum turnaround time for the job-scheduling. Simulation studies compare the performance of this model with other similar models.

关键词： computational grid Genetic Algorithm Hard Problems Job Precedence Graph NP Scheduling

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A novel resource co-allocation model with constraints to budget and deadline in computational grid

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Journal of Central South University 2009年第3期16卷 458-466页

作者：胡志刚肖鹏 School of Information Science and Engineering Central South University School of Software Central South University

To address the issue of resource co-allocation with constraints to budget and deadline in grid environments, a novel co-allocation model based on virtual resource agent was proposed. The model optimized resources deployment and price scheme through a three-side co-allocation mechanism, and applied queuing system to model the work of grid resources for providing quantitative deadline guarantees for grid applications. The validity and solutions of the model were presented theoretically. Extensive simulations were conducted to examine the effectiveness and the performance of the model by comparing with other co-allocation policies in terms of deadline violation rate, resource benefit and resource utilization. Experimental results show that compared with the three typical co-allocation policies, the proposed model can reduce the deadline violation rate to about 3.5% for the grid applications with constraints to budget and deadline. Also, the system benefits can be increased by about 30% compared with the those widely-used co-allocation policies.

关键词： co-allocation computational grid grid economy queuing theory deadline

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Adaptive Processor Allocation for Moldable Jobs in computational grid

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INTERNATIONAL JOURNAL OF grid AND HIGH PERFORMANCE COMPUTING 2009年第1期1卷 10-21页

作者： Huang, Kuo-Chan Shih, Po-Chi Chung, Yeh-Ching Natl Taichung Univ Comp & Informat Sci Dept Taichung Taiwan Natl Tsing Hua Univ Comp Sci Hsinchu Taiwan Natl Tsing Hua Univ Dept Comp Sci Hsinchu Taiwan

In a computational grid environment, a common practice is try to allocate an entire parallel job onto a single participating site. Sometimes a parallel job, upon its submission, cannot fit in any single site due to the occupation of some resources by running jobs. How the job scheduler handles such situations is an important issue which has the potential to further improve the utilization of grid resources as well as the performance of parallel jobs. This article develops adaptive processor allocation policies based on the moldable property of parallel jobs to deal with such situations in a heterogeneous computational grid environment. The proposed policies are evaluated through a series of simulations using real workload traces. The results indicate that the proposed adaptive processor allocation policies can further improve the system performance of a heterogeneous computational grid significantly.

关键词： adaptive processor allocation computational grid job scheduling moldable property

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