• Journal of the Korea Society for Simulation
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• v.17 no.4
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• pp.229-239
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• 2008

A Distributed File System (DFS) provides a mechanism in which a file can be stored across several physical computer nodes ensuring replication transparency and failure transparency. Applications that process large volumes of data (such as, search engines, grid computing applications, data mining applications, etc.) require a backend infrastructure for storing data. And the distributed file system is the central component for such storing data infrastructure. There have been many projects focused on network computing that have designed and implemented distributed file systems with a variety of architectures and functionalities. In this paper, we describe a complete distributed file system which can be used in large-scale search-oriented systems.

• KIISE Transactions on Computing Practices
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• v.21 no.8
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• pp.537-542
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• 2015

Database Shard is a technique that can be queried and stored by dividing one logical table into multiple databases horizontally. In order to analyze the shard data with aggregate or analysis functions, a process is required that integrates partial results on each shard database. In this paper, we introduce the design and implementation of a distributed processing system for aggregation and analysis on the CUBRID Shard distributed database, which is an open source database management system. The implemented system can accelerate the analysis onto multiple shards of partitioned tables; it shows efficient aggregation on shard distributed databases compared to stand-alone databases.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.15 no.6
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• pp.440-448
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• 2022

Recently, due to the introduction of distributed energy resources, the optimal resource allocation problem of the power network is more and more important, and the distributed resource allocation method is required to process huge amount of data in large-scale power networks. In the optimal resource allocation problem, many studies have been conducted on the case when the supply-demand balance is satisfied due to the limitation of the generation capacity of each generator, but the studies considering the supply-demand imbalance, that total demand exceeds the maximum generation capacity, have rarely been considered. In this paper, we propose the consensus-based distributed algorithm for the optimal resource allocation of power network considering the supply-demand imbalance condition as well as the supply-demand balance condition. The proposed distributed algorithm is designed to allocate the optimal resources when the supply-demand balance condition is satisfied, and to measure the amount of required resources when the supply-demand is imbalanced. Finally, we conduct the simulations to verify the performance of the proposed algorithm.

• Communications for Statistical Applications and Methods
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• v.22 no.1
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• pp.95-103
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• 2015

We introduce a surplus process which follows a diffusion process with positive drift and is subject to two types of claim. We assume that type I claim occurs more frequently, however, its size is stochastically smaller than type II claim. We obtain the ruin probability that the level of the surplus becomes negative, and then, decompose the ruin probability into three parts, two ruin probabilities caused by each type of claim and the probability that the level of the surplus becomes negative naturally due to the diffusion process. Finally, we illustrate a numerical example, when the sizes of both types of claim are exponentially distributed, to compare the impacts of two types of claim on the ruin probability of the surplus along with that of the diffusion process.

• Journal of the Korean Data and Information Science Society
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• v.27 no.1
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• pp.265-274
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• 2016

In this paper, we consider a diffusion risk process, in which, its surplus process behaves like a Brownian motion in-between adjacent epochs of claims. We assume that the claims occur following a Poisson process and their sizes are independent and exponentially distributed with the same intensity. Our main goal is to derive the exact formula of the joint moment generating function of the ruin time and the total amount of aggregated claim sizes until ruin in the diffusion risk process. We also provide a method for computing the related first and second moments using the joint moment generating function and the augmented matrix exponential function.

• Journal of Korea Society of Digital Industry and Information Management
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• v.8 no.4
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• pp.167-175
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• 2012

Service-oriented Architecture(SOA) is one of the most recent trends in IT solutions. SOA is a paradigm for organizing and utilizing distributed capabilities that may be under the control of different ownership domains and implemented using various technology stacks. From a technical perspective SOA, can be considered a method for designing and developing IT systems where applications are constructed from loosely coupled and autonomous building blocks. And SOA is a very effective response to the problems faced by companies in terms of reusability, interoperability and reduce coupling between systems that implement their information systems. To exploit these advantages many organizations have decided to evolve their legacy systems towards this architecture. This paper proposes a modeling for SOA based business process generation and testing, and introduces its implementation in the BPEL. And we analyze business process between enterprises, modeling the service-oriented business process with BPEL to realization level. Also, we suggests that UML is used from high-level business problems to the process of low-level problem for Visual and effectively.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.35 no.3
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• pp.163-172
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• 2012

Regarding project management, many organizations have developed and distributed general project management knowledge systems, and application fields use the knowledge systems to apply the process suitable for characteristics of a project. This study suggests project management process models to apply to system integration projects. This system integration project management process model is composed of six top processes of initiation, preparation for contract, planning, implementation management, coordination and control, and termination and transfer. The five processes are re-divided into 25 bottom processes. These processes are expressed as input, control, output, and mechanism by using the IDEF0 model. For this model development, it has chosen the items which constituted a process through a questionnaire of experts.

• Journal of the Korean Mathematical Society
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• v.33 no.4
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• pp.983-992
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• 1996

Let p(x, dy) be a transition probability function on $(S, \rho)$, where S is a complete separable metric space. Then a Markov process $X_n$ which has p(x, dy) as its transition probability may be generated by random iterations of the form $X_{n+1} = f(X_n, \varepsilon_{n+1})$, where $\varepsilon_n$ is a sequence of independent and identically distributed random variables (See, e.g., Kifer(1986), Bhattacharya and Waymire(1990)).

• Communications for Statistical Applications and Methods
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• v.15 no.6
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• pp.959-967
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• 2008

In this paper we show the weak convergence of the linear random(multistochastic process) field generated by identically distributed 2-parameter array of associated random variables. Our result extends the result in Newman and Wright (1982) to the linear 2-parameter processes as well as the result in Kim and Ko (2003) to the 2-parameter case.

• Industrial Engineering and Management Systems
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• v.14 no.1
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• pp.32-43
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• 2015

This study suggests an electronic brokerage system that has the capability of efficiently matching dispatching delivery tasks with trucks. In the brokerage system, individual truck drivers and shippers are allowed to participate in the dispatching process through the internet or wireless communication. An auction-based dispatching method for the electronic brokerage system is suggested. The basic rationale of the auction-based dispatching method-which is a distributed decision-making process-is discussed. The performance of the suggested algorithms is evaluated by a simulation study.