• 한국CDE학회논문집
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• 제11권5호
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• pp.384-392
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• 2006

In this research, the feasibility of distributed finite element analysis system with STEP and CORBA has been investigated. The enabling technologies such as CORBA and Java play key roles in the development of integrated and geographically distributed application software. In addition to the distribution of analysis modules, numerical solution process itself is again divided into parallel processes using multi-frontal method for computational efficiency. In contrast to the specially designed parallel process for specific hardware, CORBA-based parallel process is well suited for heterogeneous platforms over the network. The idea of Web-based distributed analysis system may be applied to the engineering ASP for design and analysis in the product development processes. We believe that the proposed approach for the analysis can be extended to the entire product development process for sharing and utilizing common product data in the distributed engineering environment, thus eventually provide basis for virtual enterprise.

• 전자공학회논문지CI
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• 제41권6호
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• pp.23-37
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• 2004

자바의 쓰레드는 다중 처리 환경에서 하나의 프로그램 공간 내의 독립적인 프로세스로 취급되는 객체 요소이므로 병렬처리를 위한 독립적인 프로세스로 활용할 수 있다. 또한, 자바의 동기화 메커니즘과 쓰레드를 활용하면 병렬 처리를 수행하는 응용프로그램을 쉽게 작성할 수 있다. 이에 따라, 자바의 병렬 처리 지원 기능을 분산된 컴퓨팅 환경에 적용하기 위한 많은 연구 결과가 있다. 본 논문에서는 레거시 자바 프로그램에 포함된 쓰레드를 분산된 컴퓨팅 환경에서 병렬 수행 하도록 지원하는 시스템 환경을 제안한다. TORB(Transparent Object Request Broker)라고 명명된 본 시스템은 프로그래밍 투명성을 지원하므로 이미 작성된 레거시 자바 프로그램을 간단한 변환 과정을 거친 후 병렬 수행 하도록 지원한다. TORB는 본 연구팀에서 이미 발표한 분산 프로그래밍 도구의 기능을 확장한 것이며, 이는 지정된 기능을 지정된 컴퓨터에서 수행하도록 지원하는 전형적인 분산처리 기능만을 보유하고 있었다.

• 한국시뮬레이션학회:학술대회논문집
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• 한국시뮬레이션학회 1992년도 제2회 정기총회 및 추계학술 발표회 발표논문 초록
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• pp.5-5
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• 1992

The DEVS(discrete event system specification) formalism describes a discrete event system in a hierarchical, modular form. DEVSIM++ is C++ based general purpose DEVS abstract simulator which can simulate systems to be modeled by the DEVS formalism in a sequential environment. We implement P-DEVSIM++ which is a parallel version of DEVSIM++. In P-DEVSIM++, the external and internal event of models can be processed in parallel. To process in parallel, we introduce a hierarchical distributed simulation technique and some optimistic distributed simulation techniques. But in our algorithm, the rollback of a model is localized itself in contrast to the Time Warp approach. To evaluate its performance, we simulate a single bus multiprocessor architecture system with an external common memory. Simulation result shows that significant speedup is made possible with our algorithm in a parallel environment.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2003년도 하계종합학술대회 논문집 V
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• pp.2561-2564
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• 2003

Data mining is an effective method of the discovery of useful information such as rules and previously unknown patterns existing in large databases. The discovery of association rules is an important data mining problem. We have developed a new parallel mining called Distributed Frequent Pattern Tree (abbreviated by DFPT) algorithm on a distributed shared nothing parallel system to detect association rules. DFPT algorithm is devised for parallel execution of the FP-growth algorithm. It needs only two full disk data scanning of the database by eliminating the need for generating the candidate items. We have achieved good workload balancing throughout the mining process by distributing the work equally to all processors. We implemented the algorithm on a PC cluster system, and observed that the algorithm outperformed the Improved Count Distribution scheme.

• International Journal of Computer Science & Network Security
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• 제21권12spc호
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• pp.570-578
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• 2021

Recently, in the field of engineering and scientific and technical calculations, problems of mathematical modeling, real-time problems, there has been a tendency towards rejection of sequential solutions for single-processor computers. Almost all modern application packages created in the above areas are focused on a parallel or distributed computing environment. This is primarily due to the ever-increasing requirements for the reliability of the results obtained and the accuracy of calculations, and hence the multiply increasing volumes of processed data [2,17,41]. In addition, new methods and algorithms for solving problems appear, the implementation of which on single-processor systems would be simply impossible due to increased requirements for the performance of the computing system. The ubiquity of various types of parallel systems also plays a positive role in this process. Simultaneously with the growing demand for parallel programs and the proliferation of multiprocessor, multicore and cluster technologies, the development of parallel programs is becoming more and more urgent, since program users want to make the most of the capabilities of their modern computing equipment[14,39]. The high complexity of the development of parallel programs, which often does not allow the efficient use of the capabilities of high-performance computers, is a generally accepted fact[23,31].

• Journal of Information Processing Systems
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• 제12권1호
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• pp.149-168
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• 2016

The Active Appearance Model (AAM) is a class of deformable models, which, in the segmentation process, integrates the priori knowledge on the shape and the texture and deformation of the structures studied. This model in its sequential form is computationally intensive and operates on large data sets. This paper presents another framework to implement the standard version of the AAM model. We suggest a distributed and parallel approach justified by the characteristics of the model and their potentialities. We introduce a schema for the representation of the overall model and we study of operations that can be parallelized. This approach is intended to exploit the benefits build in the area of advanced image processing.

• 한국전산구조공학회논문집
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• 제12권3호
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• pp.385-396
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• 1999

최근 공학분야에서 다루어지고 있는 문제의 규모가 대형화하고 있으며 이러한 대형구조물의 구조설계는 부재의 강도설계 및 절점의 변위조절을 위하여 많은 수의 구조해석을 요구한다. 한 대의 개인용 컴퓨터에 의한 대형구조물의 구조해석은 대용량의 기억장치와 많은 계산 시간이 요구되므로 반복적 해석이 필요한 대형구조물의 설계에 효율적으로 이용되기 어려운 실정이다. 따라서, 본 논문에서는 이러한 문제에 대한 대안으로 다수의 개인용 컴퓨터들을 네트워크로 연결하여 고성능 병렬연산시스템을 구성하고 이에 적합한 두 가지 형태의 분산구조방정식해법들을 반복법인 PCG 알고리즘을 이용하여 개발하였다. 대형구조물을 위한 분산구조해석법은 구조해석 과정에 요구되는 각 컴퓨터 상호 간의 통신회수와 통신량을 최소화할 수 있도록 개발되었다. 분산구조해석법의 성능은 대규모 3차원 트러스 구조물 및 144층 가새 튜브구조물의 구조해석에 적용하여 분석하였다.

• International Journal of Internet, Broadcasting and Communication
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• 제4권1호
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• pp.13-17
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• 2012

Indexing allows converting raw document collection into easily searchable representation. Web searching by Google or Yahoo provides subsecond response time which is made possible by efficient indexing of web-pages over the entire Web. Indexing process gets challenging when the scale gets bigger. Parallel techniques, such as MapReduce framework can assist in efficient large-scale indexing process. In this paper we propose PDFindexer, system for indexing scientific papers in PDF using MapReduce programming model. Unlike Web search engines, our target domain is scientific papers, which has pre-defined structure, such as title, abstract, sections, references. Our proposed system enables parsing scientific papers in PDF recreating their structure and performing efficient distributed indexing with MapReduce framework in a cluster of nodes. We provide the overview of the system, their components and interactions among them. We discuss some issues related with the design of the system and usage of MapReduce in parsing and indexing of large document collection.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2000년도 ITC-CSCC -1
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• pp.314-317
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• 2000

Cluster system provides attractive scalability in terms of computation power and memory size. With the advances in high speed computer network technology, cluster systems are becoming increasingly competitive compared to expensive parallel machines. In parallel processing program, each task load is difficult to predict before running the program and each task is interdependent each other in many ways. Load imbalancing induces an obstacle to system performance. Most of researches in load balancing were concerned with distributed system but researches in cluster system are few. In cluster system, the dynamic load balancing algorithm which evaluates each processor's load in runtime is purpose that the load of each node are evenly distributed. But, if communication cost or node complexity becomes high, it is not effective method for all nodes to attend load balancing process. In that circumstances, it is good to reduce the number of node which attend to load balancing process. We have modeled cluster systems and proposed marginal dynamic load balancing algorithms suitable for that circumstances.

• ETRI Journal
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• 제15권3_4호
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• pp.1-26
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• 1994

Simulated annealing is an attractive, but expensive, heuristic method for approximating the solution to combinatorial optimization problems. Attempts to parallel simulated annealing, particularly on distributed memory multicomputers, are hampered by the algorithm's requirement of a globally consistent system state. In a multicomputer, maintaining the global state S involves explicit message traffic and is a critical performance bottleneck. To mitigate this bottleneck, it becomes necessary to amortize the overhead of these state updates over as many parallel state changes as possible. By using this technique, errors in the actual cost C(S) of a particular state S will be introduced into the annealing process. This paper places analytically derived bounds on this error in order to assure convergence to the correct optimal result. The resulting parallel simulated annealing algorithm dynamically changes the frequency of global updates as a function of the annealing control parameter, i.e. temperature. Implementation results on an Intel iPSC/2 are reported.