• Journal of Korea Multimedia Society
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• v.13 no.1
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• pp.1-9
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• 2010

Today's growth of the mobile communication infrastructure made mobile computing systems like cellular phones came next to or surpassed the desktop PCs in popularity due to their mobility. Although the performance of mobile devices is now being improved continuously, it is a current common sense that compute intensive large-scale applications can hardly run on any kind of mobile handset devices. To clear up this problem, we decided to exploit the mobile cluster computing system and surveyed the existing ones first. We found out, however, that most of them are not the actual implementations but a mobile cluster infrastructure proposal or idea suggestions for reliable mobile clustering. To make cell phones participated in cluster computing nodes, in this paper, we propose a redesigned JPVM cluster computing engine and a set of WIPI mobile runtime functions interfacing with it. And we also show the performance evaluation results of real parallel applications running on our Mobile-JPVM cluster computing systems. We find out by the performance evaluation that large-scale applications can sufficiently run on mobile devices such as cellular phones when using our mobile cluster computing engine.

• Journal of the Semiconductor & Display Technology
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• v.15 no.2
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• pp.20-25
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• 2016

The parallel computer cluster system has been known as the powerful tool to solve a complex physical phenomenon numerically. The numerical analysis of large size of Li-ion battery pack, which has a complex physical phenomenon, requires a large amount of computing time. In this study, the numerical analyses were conducted for comparing the computing efficiency between the single workstation and the parallel cluster system both with multicore CPUs'. The result shows that the parallel cluster system took the time 80 times faster than the single work station for the same battery pack model. The performance of cluster system was increased linearly with more CPU cores being increased.

• Structural Engineering and Mechanics
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• v.37 no.1
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• pp.17-37
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• 2011

This paper presents a new Internet-based computational framework for the realistic simulation of multi-scale response of structural systems. Two levels of parallel processing are involved in this frame work: multiple local distributed computing environments connected by the Internet to form a cluster-to-cluster distributed computing environment. To utilize such a computing environment for a realistic simulation, the simulation task of a structural system has been separated into a simulation of a simplified global model in association with several detailed component models using various scales. These related multi-scale simulation tasks are distributed amongst clusters and connected to form a multi-level hierarchy. The Internet is used to coordinate geographically distributed simulation tasks. This paper also presents the development of a software framework that can support the multi-level hierarchical simulation approach, in a cluster-to-cluster distributed computing environment. The architectural design of the program also allows the integration of several multi-scale models to be clients and servers under a single platform. Such integration can combine geographically distributed computing resources to produce realistic simulations of structural systems.

• 한국전산유체공학회:학술대회논문집
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• 2001.10a
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• pp.182-189
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• 2001

A project has been initiated at KISTI Supercomputing Center at year 1999 to build a Tflops cluster in order to support newly emerging demands for larger scale parallel computing resources. As a supportive substitute of traditional supercompters, the cluster systems are expected to play important role in supporting diversified computational needs. In this paper, KISTI Supercomputing Center's working status of building Tflops cluster system and future plans.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.8 no.5
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• pp.1618-1637
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• 2014

Clustering wireless sensor network is an efficient way to reduce the energy consumption of individual nodes in a cluster. In clustering, multihop routing techniques increase the load of the Cluster head near the sink. This unbalanced load on the Cluster head increases its energy consumption, thereby Cluster heads die faster and create an energy hole problem. In this paper, we propose an Energy Balancing Cluster Head (EBCH) in wireless sensor network. At First, we balance the intra cluster load among the cluster heads, which results in nonuniform distribution of nodes over an unequal cluster size. The load received by the Cluster head in the cluster distributes their traffic towards direct and multihop transmission based on the load distribution ratio. Also, we balance the energy consumption among the cluster heads to design an optimum load distribution ratio. Simulation result shows that this approach guarantees to increase the network lifetime, thereby balancing cluster head energy.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.14 no.3
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• pp.287-298
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• 2001

Analysis of nonlinear behavior of prestressed concrete frame structures on PC is a time-consuming computing job if the problem size increase to a certain degree. Cluster system has emerged as one of promising computing environments due to its good extendibility, portability, and cost-effectiveness, comparing it with high-end work-stations or servers. In this paper, a parallel nonlinear analysis procedure of prestressed concrete frame structure is presented using cluster computing. Cluster system is configured with readily available pentium III class PCs under Win98 or Linux and fast ethernet. Parallel computing algorithms on element-wise processing parts including the calculation of stiffness matrix, element stresses and determination of material states, check of material failure and calculation of unbalanced loads are developed using MPL. Validity of the method is discussed through typical numerical examples. For the case of 4 node system, maximum speedup is 3.15 and 3.74 for Win98 and Linux, respectively. Important issues for the efficient use of cluster computing system based un PCs and ethernet are addressed.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.28 no.5
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• pp.604-611
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• 2004

Simulation of three-dimensional turbulent flow with LES and DNS lakes much time and expense with currently available computing resources and requires big computing resources especially for high Reynolds number. The emerging alternative to provide the required computing power and working environment is the Grid computing technology. We developed the CFD code which carries out the parallel computing under the Grid environment. We constructed the Grid environment by connecting different PC-cluster systems located at two different institutes of Pusan National University in Busan and KISTI in Daejeon. The specification of PC-cluster located at two different institutes is not uniform. We run our parallelized computer code under the Grid environment and compared its performance with that obtained using the homogeneous computing environment. When we run our code under the Grid environment, the communication time between different computer nodes takes much larger time than the real computation time. Thus the Grid computing requires the highly fast network speed.

• Journal of KIISE:Computing Practices and Letters
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• v.12 no.1
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• pp.21-30
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• 2006

As the amount of information to be processed by computers has recently been increased, there has been cluster computing systems developed by connecting PCs and workstations using high-speed networks. hs a result, the studies on a cluster-based DBMS have been done with a wide range and it is necessary to develop a cluster manager for monitoring and managing cluster-based DBMSs. But, a cluster manager for efficiently managing cluster-based DBMSs has been studied in a first step. In this paper, we design and implement a high-availability cluster manager for a cluster-based DBMS. It monitors the status of nodes in cluster systems as well as the status of DBMS instances in a node, by using a graphic user interface (GUI). Our cluster manager supports the high-availability for a cluster-based DBMS by perceiving errors and recovering them, based on the monitored information on the status of a server.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.9 no.7
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• pp.2649-2666
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• 2015

In the dynamic cloud computing environment, to ensure, under the terms of service-level agreements, the maximum efficiency of resource utilization, it is necessary to investigate the online dynamic management of virtual machine resources and their operational application systems/components. In this study, the feasibility and properties of the division of virtual machine resources on the cloud platform, using the virtual machine cluster as the management unit, are investigated. First, the definitions of virtual machine clusters are compared, and our own definitions are presented. Then, the feasibility of division using the virtual machine cluster as the management unit is described, and the isomorphism and reconfigurability of the clusters are proven. Lastly, from the perspectives of clustering and cluster segmentation, the dynamics of virtual machines are described and experimentally compared. This study aims to provide novel methods and approaches to the optimization management of virtual machine resources and the optimization configuration of the parameters of virtual machine resources and their application systems/components in large-scale cloud computing environments.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.31 no.5
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• pp.37-43
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• 2003

Parallel computing method is widely used in the computational fluid dynamics for efficient numerical analysis. Nowadays, low cost Linux cluster computers substitute for traditional supercomputers with parallel computing shcemes. The performance of nemerical solvers on an Linux cluster computer is highly dependent not on the performance of processors but on the performance of network devices in the cluster system. In this paper, we investigated the effects of the network devices such as Myrinet2000, gigabit ethernet, and fast ethernet on the performance of the cluster system by using some benchmark programs such as Netpipe, LINPACK, NAS NPB, and MPINS2D Navier-Stokes solvers. Finally, upon this investigation, we will suggest the method for building high performance low cost Linux cluster system in the computational fluid dynamics analysis.