• Asia pacific journal of information systems
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• v.11 no.2
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• pp.121-139
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• 2001

VOQL* query language, recently proposed, is a visual language for object-oriented databases. It is based on Ven Diagram and graph, so that the underlying schema structure can be naturally implied in query expressions. In VOQL*, structural relationship among the objects used in a query expression is represented graphically and thus it has formal semantics that can be inductively defined, as well as it can be used with ease. In this paper, we proposed revised VOQL* and introduced its query processor, InQs(Intelligent Querying System). While retaining the merit of VOQL* that it allows the structural relationship among the objects to be represented visually, the revised VOQL* has another merit that users can formulate a query interactively using various forms supplied by InQs. As a query processor that translates queries in revised VOQL into those in ODMG OQL, InQs provides an environment in which users express queries in revised VOQL* and then the system automatically translates them into those in ODMG OQL. Translation algorithm of InQs is much simpler and intuitive than other algorithms used in QUIVER and other systems, since it reflects the formal semantics of VOQL*, which is defined inductively.

• The Transactions of the Korea Information Processing Society
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• v.6 no.12
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• pp.3523-3529
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• 1999

In this paper, we propose an improved regression testing method, which use method as the basic unit of changing. The testing method consists of three steps. We represent the relationship of classes using the notation of UML(Unified Modeling Language), find the nodes of the modified methods and affected methods by node analysis, and then select changed test cases from the original test cases. The proposed object-oriented regression testing method can reduce the number of test cases, testing time and cost through reuse of test cases.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.29 no.10C
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• pp.1363-1369
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• 2004

LDPC(Low Density Parity Check) codes are described by bipartite graphs with bit nodes and parity-check nodes. Tanner derived minimum distance bounds of the regular LDPC code in terms of the eigenvalues of the associated adjacency matrix. In this paper we generalize the Tanner's results. We derive minimum distance bounds applicable to both regular and blockwise-irregular LDPC codes. The first bound considers the relation between bit nodes in a minimum-weight codeword, and the second one considers the connectivity between parity nodes adjacent to a minimum-weight codeword. The derived bounds make it possible to describe the distance property of the code in terms of the eigenvalues of the associated matrix.

• Journal of KIISE:Computing Practices and Letters
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• v.5 no.6
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• pp.719-726
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• 1999

본 논문은 교통 신호 제어 알고리즘들의 성능을 비교하기 위한 복합교차로 시뮬레이터를 구현하였다. 기존의 교통 시뮬레이터들은 단일교차로를 대상으로 하거나 텍스트 모드로 동작하는 경우가 많았다. 논문의 시뮬레이터는 Visual C++의 MFC 라이브러리를 사용하여 n $\times$ n 형태를 갖는 복합교차로에 적합하도록 객체지향적으로 구현되었으며, 성능 비교를 위하여 제어 알고리즘들을 별개의 윈도우에서 처리하기 쉽도록 MDI 방식을 사용하였다. 개발한 시뮬레이터는 그래프 윈도우와 맵 윈도우의 편리한 사용자 인터페이스, 논리시간 설정을 통한 다목적 시뮬레이션, 다양한 성능평가 출력 등의 특징을 갖는다. Abstract In this paper, we implemented a multiple crossroad simulator to evaluate the performance of the traffic signal control algorithms. Most of existing traffic simulators were operated in text-mode or at a single intersection. We developed the object-oriented simulator suitable for multiple crossroads with n $\times$ n intersections by using MFC (Microsoft Foundation Class) library in Visual C++. The simulator was implemented by using MDI (Multiple Document Interface) scheme in order to process both control algorithms in separate windows respectively. Our simulator has the following features: user friendly interface with graph window and map window, multi-purpose simulations by setting logical time, and various forms of performance evaluation.

• Journal of the Korean Society for Precision Engineering
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• v.21 no.2
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• pp.100-107
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• 2004

The development of a Web-based powertrain performance simulation system is introduced. The development approach of system architecture and each module is introduced along with the H/W and S/W used. The interface with all users is developed via a JAVA Applet. The powertrain modeling and other job history data of a user is managed systematically on the server by database to increase the reusability of the data. A self-developed program using object-oriented programming is used as a solver for the performance simulation. The graph tool for the analysis of simulation results has the collaboration support developed based on JAVA so that synchronous users can view the same result. As a result, the powertrain simulation is possible only with Web-browser for the user and the collaboration support among the relevant engineers is possible.

• The Transactions of the Korea Information Processing Society
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• v.7 no.11
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• pp.3372-3383
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• 2000

객체지향 패러다임에서 응집도가 높은 클래스들은 단 하나의 데이터 요소만이 정의되고 모든 메소드(또는 연산)들이 그 데이터 요소 상에서 수행되거나, 메소드와 데이터 요소간에 최대연결이 이루어진 클래스이다. 따라서 데이터 요소의 증가와 최대연결을 저해하는 연산들은 클래스의 응집을 저해하는 주 요인들이다. 본 연구에서는 이러한 저해요인들에 근거하여, 응집도에 관한 우리의 직관과 더욱 일치하는 측정을 할 수 있는 새로운 클래스 응집도 척도인 CM(Cohesion Metric)을 제안하였다. 본 연구에서는 응집도를 저해하는 요인의 식별을 위해 참조 그래프(reference graph)를 이용하고, 참조 그래프의 분석을 기초로 하여 클래스의 응집도를 측정하였다. 또한 제한된 CM 측정값이 응집도 척도가 만족해하는 특성들을 만족함을 보였고, 기존 응집도 척도들과의 비교평가를 통해서 CM이 기존의 척도들보다 향상된 측정을 제시함을 보였다.

• Proceedings of the IEEK Conference
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• 2002.06b
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• pp.353-356
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• 2002

Due to the increased complexity and size of digital system and the need of the H/W-S/W co-design, C/C++ based system design methodology gains more Interests than ever in EDA field. This paper suggests the methodology in which handshake module corresponding to each basic statement of C is provided of the form of STG(Signal Transition Graph) and then, C statements is synthesized into asynchronous circuit through syntax-oriented translation. The 4-phase handshaking protocol is used for the communications between modules, and the modules are synthesized by the Petrify which is asynchronous logic synthesis CAD tool.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.06a
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• pp.1747-1750
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• 2003

The development of a Web-based powertrain performance simulation system is introduced. The development approach of system architecture and each module is introduced along with the H/W and S/W used. The interface with all users is developed via a JAVA applet. The powertrain modeling and other job history data of a user is managed systematically on the server by database to increase the reusability of the data. A self-developed program using object-oriented programming is used as a solver for the performance simulation. The graph tool for the analysis of simulation results has the collaboration support developed based on JAVA so that synchronous users can view the same result. As a result, the powertrain simulation is possible only with Web-browser for the user and the collaboration support among the relevant engineers is possible.

• Journal of the Korea Society for Simulation
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• v.21 no.2
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• pp.103-112
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• 2012

Traditional system-oriented measures are no longer adequate to describe the availability perceived by the user. In this paper we investigate the service availability model and the user behavior graph. And we propose the simulation model, which determines the sevice availability considering user model, system model and service model at the same time. Through the example, we show how to construct the UBG of user model, system model and service model. And we investigate the effect of the parameters of system model and UBG on the service availability.

• Proceedings of the KSRS Conference
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• 2008.10a
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• pp.72-75
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• 2008

Image segmentation techniques becoming increasingly important in the field of remote sensing image analysis in areas such as object oriented image classification. This paper presents a new method for image segmentation in High Resolution Remote Sensing Image based on Seeded Region Growing (SRG) and Edge Information. Firstly, multi-spectral edge detection was done using an entropy operator in pan-sharpened QuickBird imagery. Then, the initial seeds were automatically selected from the obtained edge map. After automatic selection of significant seeds, an initial segmentation was achieved by applying SRG. Finally the region merging process, using region adjacency graph (RAG), was carried out to get the final segmentation result. Experimental results demonstrated that the proposed method has good potential for application in the segmentation of high resolution satellite images.