• The Transactions of the Korea Information Processing Society
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• v.5 no.10
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• pp.2567-2574
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• 1998

Many software engineering tools and techniques rely on fraphic representations of software, such as control flow graphs, program dependene graphs, or system dependence graphs. Existing graphic representations for object-oriented programs are compkicated, reduplicated. We thus propose a new graphic representation for object-oriented programs. Object-oriented Program Dependency Graph (OPDG). An OPDG consists of class dependence graph, class hierarchy graph and procedure dependence graph. Other features of OPDG are (1) the representation is compact; (2) the representation is easy to extend for the incremental development of a program; and (3) the repreesentation can be extended to provide dynamic information.

• Korean Journal of Ecology and Environment
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• v.33 no.2 s.90
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• pp.80-108
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• 2000

This paper deals with floristic and taxonomic accounts of 47 taxa of the genus Trachelomonas collected from 58 waters in Korea. Of these, 19 taxa are added to the Korean Trachelomonas flora, and 4 taxa, T. curta var. reticulata, T. koreana, T. planctonica var. papillosa, and T. spina are newly recorded in the world flora of the euglenoids. Detailed description and illustrations are given for each species. Since 23 taxa are previously reported in the Korean freshwaters, a total of 70 taxa are listed up in the Korean Trachelomonas flora. Trachelomonas species are abundant and diverse in old or stagnant swamps or ponds, where is enriched with organic matters and nutrient salts. T. bacillifera, T. hispida, and T. volvocina formed water blooming in the natural swamps or fishery ponds in spring and summer.

• The Journal of the Korea Contents Association
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• v.5 no.4
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• pp.204-211
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• 2005

This paper introduces three loop splitting methods such as minimum dependence distance method, Polychronopoulous' method, and first dependence method for exploiting parallelism from single loop which already developed. And it also Indicates their several problems. We extend the first dependence method which is the most effective one among three loop splitting methods, and propose more powerful loop splitting method to enhance parallelism on single loop. The proposed algorithm solves several problems, such as anti-flow dependence and g=gcd(a,c) > 1, that the first dependence method has.

• The Transactions of the Korea Information Processing Society
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• v.5 no.10
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• pp.2479-2497
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• 1998

하이퍼미디어시스템을 모델링하기 위해 제공되는 기존의 표준 모델들이나 SGML을 이용하여 설계된 하이퍼미디어 시스템들은 저마다 서로 다른 정보기술 및 저장 방법론을 제시하고 있어 이질적인 시스템간의 문서 교환이나 프리젠테이션을 어렵게 만들고 있다. 그리고 사용자 인터랙션의 처리나 시간종속적 멀티미디어 객체(time-dependent multimedia object)들의 표현에 있어서도 많은 제한점들을 가진다. 본 논문에서는 시간종속적 멀티미디어 객체들을 효율적으로 표현할 수 있고 사용자의 인터랙션에 따라 멀티미디어 객체들을 서로 다른 정보 영역으로 링크시키며 시간종속적 링크를 제공해 주는 시간종속적 하이퍼미디어 시스템(Time-dependent Hypermedia System)을 모델링하고, 그러한 하이퍼미디어 시스템을 기술하기 위한 SGML 문서타입 정의부(Document Type Definition : DTD)를 설계한다. DTD의 설계에 있어서는 멀티미디어 객체들의 동기화를 위한 스케줄링 메커니즘과 다양한 노드 형태의 기술에 중점을 두고, 사용자들에게 구조 및 개념 파악의 용이성을 제공하기 위해 모듈 개념을 적용하였다.

• Journal of KIISE:Computer Systems and Theory
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• v.28 no.8
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• pp.379-389
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• 2001

본 논문에서는 루프 반복들 간에 종속 관계가 존재하는 루프의 효율적 수행을 위한 새로운 루프 할당 기법을 제안한다. 그리고, 중앙 큐를 사용하여 공유 메모리 다중처리기에 루프 반복을 할당하는 기존 셀프 스케쥴링 기법들을 루프 캐리 종속성(loop-carried dependence)을 가진 루프의 할당에 적용하기 위해 제안한 기법을 이용한 그들의 변형에 대해 알아본다. 종속 거리를 고려하여 루프를 세 단계별로 할당하는 제안된 CDSS(Carried-Dependence Self-Scheduling) 기법 또한, 중앙 작업 큐를 기반으로 한 것이며 별도의 스케쥴러가 필요 없는 셀프 스케쥴링 알고리즘이다. 종속거리, 프로세서 수, 반복 수, 스케쥴링 연산 시간 등을 다양하게 하여 변형된 할당 기법들과 비교 분석한 결과, 제안한 기법은 양호한 부하 균형을 유지하였으며 변형된 다른 기법들에 비해 루프 수행 시간을 줄여 효율적임을 알 수 있었다. 다양한 실험 환경에서 평균적으로 제안한 CDSS, 변형된 SS, Factoring, GSS, CSS 기법 순으로 루프 수행 시간 측면에서 좋은 성능을 보였다.

• The Transactions of the Korea Information Processing Society
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• v.5 no.6
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• pp.1494-1506
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• 1998

본 논문에서는 루프구조의 효율적인 병렬수행을 위한 병렬성 추출에 대하여 불변과 가변 종속거리에 모두적용할 수 있는 통합된 새로운 기법을 제시한다. 이것은 컴파일시간에 순차 루프를 중첩된 DOALL 루프로의 자동 변환에 대한 절차로서, 중첩 루프의 전체적인 병렬화를 하기 위하여 문장들을 반복적으로 수행시키는 것에 의해서 자료 종속을 효과적으로 제거하는 알고리즘이다. 본 논문에 제시된 방법은 성능평가에서도 매우 뛰어난 방법임을 보였다.

• The Transactions of the Korea Information Processing Society
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• v.6 no.2
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• pp.261-274
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• 1999

Recently, automated business processing systems, so called workflow systems, have been studied. have been studied. even though each task has noticible duration inherently, most of previous models regard it as a simple finite automation where state transitions occur instantly. In this paper, we propose a modeling method for workflow each of whose component task has minimum processing time and due-date. Firstly we provide a priority function to choose the proper alternatives when tasks fail before their due-date. The priority function considers the time-relevant factor and the semantic compatibility level to decide the best alternative. secondly, we identify six different types of execution requirements for tasks with noticible durations. They are serial, parallel, simultaneous start simultaneous termination, interleaved and nested dependency. Note that previous models deal with only serial execution and parallel execution. Lastly, we also propose graph-based methods to detect logical conflicts in time constraint-based workflow specifications.

• The Journal of Korean Association of Computer Education
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• v.8 no.1
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• pp.93-103
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• 2005

Since the most program execution time is consumed in a loop structure, extracting parallelism from sequential loop programs is critical for the faster program execution. Conventional studies for extracting the parallelism are focused mostly on a uniform data dependence distance. In this paper, we proposed data dependency elimination method for a nested loop and extended data dependency elimination method to extract parallelism from the loop with procedure calls. The data dependency elimination method and the extended data dependency elimination method can be applied to uniform and non-uniform data dependency distance. We compared our method with conventional methods using CRAY-T3E for the performance evaluation. The results show that the proposed algorithms are very effective.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.37 no.7
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• pp.427-433
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• 1988

This paper presents a partitioned state estimation algorithm on the basis of network reduction by using a estimation technique of boundary line flows. The network is partitioned into several subnetworks, which generates boundary lines. The accurate estimation of boundary line flows enables us to perform state estimation on each sub-system independently. A precise method to estimate boundary line flows is presented for the partitioned state estimation. The proposed algorithm redices computation time and memory requirements remarkably. The proposed algorithm have been tested for IEEE sample system and verified to be applicable to practical power systems.

• Journal of the Korea Computer Industry Society
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• v.6 no.2
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• pp.365-372
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• 2005

Generally, In a application program the core part for parallel processing is a loop. therefore exist data dependencies between the array index variables of a loop. The data dependence relations between statements which from variable or constant dependence distance are specially complex. Therefore extracting parallelism for those statements at compile time is very difficult. in this paper, among the proposed methods of extracting parallelism, analysis the unimodular method and non-unimodular method and grasping the merits and demerits of them. hereafter, this method will go far toward solving the effectively extracting parallelism of the loop.