• 제어로봇시스템학회:학술대회논문집
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• 1991.10a
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• pp.589-594
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• 1991

Group Technology (GT) is a technique for identifying and bringing together related or similar components in a production process in order to take advantage of their similarities by making use of, for example, the inherent economies of flow production methods. The process of identification, from large variety and total of components, of the part families requiring similar manufacturing operations and forming the associated groups of machines is referred as 'machine-component grouping'. First part of this paper is devoted to describing a hierarchical divisive algorithm based on graph theory to find the natural part families. The objective is to form components into part families such that the degree of inter-relations is high among components within the same part family and low between components of different part families. Second part of this paper focuses on establishing cell design procedures. The aim is to create cells in which the most expensive and important machines-called key machine - have a reasonably high utilization and the machines should be allocated to minimize the intercell movement of machine loads. To fulfil the above objectives, 0-1 integer programming model is developed and the solution procedures are found. Next an attempt is made to test the feasibility of the proposed method. Several different problems appearing in the literature are chosen and the results air briefly showed.

• Journal of KIISE:Computer Systems and Theory
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• v.30 no.12
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• pp.691-698
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• 2003

In this paper, we propose a problem, called one-to-one disjoint path cover problem, whether or not there exist k disjoint paths joining a pair of vertices which pass through all the vertices other than the two exactly once. A graph which for an arbitrary k, has a one-to-one disjoint path cover between an arbitrary pair of vertices has a hamiltonian property stronger than hamiltonian-connectedness. We investigate this problem on recursive circulants and prove that for an arbitrary k $k(1{\leq}k{\leq}m)$$ G(2^m,4)$,$m{\geq}3$, has a one-to-one disjoint path cover consisting of k paths between an arbitrary pair of vortices.

• Journal of KIISE:Computer Systems and Theory
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• v.28 no.7
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• pp.331-340
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• 2001

이 논문은 인과적 메시지 로깅 기법에서 결함 포용을 목적으로 안전 저장 장치(stable storage)에 저장되는 메시지 내용 로그와 메시지 순서 로그의 쓰레기 처리 기법을 제안한다. 기존의 인과적 메시지 로깅을 기반으로 한 메시지 로그 쓰레기 처리 기법은 메시지 순서 로그의 쓰레기만을 처리하였다. 메시지 내용 로그는 불필요한 복귀를 피하기 위해 유지해야 하며, 메시지내용 로그의 쓰레기 처리를 위해서는 부가적인 메시지를 필요로 하였다. 이 논문은 인과적 메시지 로깅 기법에서 메시지 내용 로그와 메시지 순서 로그가 쓰레기 처리되어지기 위해 필요한 조건을 새롭게 정의하며, 이 정의를 기반으로 한 메시지 내용 로그와 메시지 순서 로그의 쓰레기 처리 알고리즘을 제안한다. 제시된 조건을 기반으로 한 메시지 내용 로그와 메시지 순서 로그의 쓰레기 처리는 송수신 메시지에 부가된 MAG(Modified Antecednce Graph)를 이용하므로 쓰레기 처리를 위한 부가적인 메시지를 발생시키지 않는다. 하지만 제안된 기법은 일반 메시지가 송수신되기 전까지 쓰레기 처리가 지연되는 '지연 쓰레기 처리 현상(lazy garbage collection)'을 발생시킨다. 하지만 '지연 쓰레기 처리 현상'은 분산 시스템의 일관성을 위배하지 않으며, 쓰레기 처리를 위한 부가적인 메시지 교환을 필요로 하지 않는다.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.55 no.9
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• pp.351-358
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• 2006

In this paper, DSPOCS(Digital Switchgear-Panel Operation and Control Solution) is designed, which is the intelligent inference based operation and control solution to obtain the safety and reliability of electric power supply in substation based on IED. DSPOCS is designed as a scheduled monitoring and control task and a real-time alarm inference task, and is interlinked with BRES(Bus Reconfiguration Expert System) in the required case. The intelligent alarm inference task consists of the alarm knowledge generation part and the real-time pattern matching part. The alarm knowledge generation part generates automatically alarm knowledge from DB saves it in alarm knowledge base. On the other hand, the pattern matching part inferences the real-time event by comparing the real-time event information furnished from IEDs of substation with the patterns of the saved alarm knowledge base.; Especially, alarm knowledge base includes the knowledge patterns related with fault alarm, the overload alarm and the diagnosis alarm. In order to design the database independently in substation structure, busbar is represented as a connectivity node which makes the more generalized graph theory possible. Finally, DSPOCS is implemented in MS Visual $C^{++}$, MFC, the effectiveness and accuracy of the design is verified by simulation study to the typical distribution substation.

• Transactions of the Korean Society of Mechanical Engineers
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• v.17 no.6
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• pp.1330-1341
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• 1993

The kinematic synthesis deals with the systematic design of mechanisms for a given performance. The area of synthesis may be grouped into two categories to determine the type and to size the dimensions of a mechanism for a specified task. In this paper, using a database of mechanisms a designer can determine the type of mechanism conveniently and design equations are automatically generated for a given input performance. The solving method of design equations utilizes an optimization routine to obtain roots effectively. The linkages of 4, 6, and 8bars with revolute joints are considered in this study but may be extended to linkages of more bars.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.17 no.3
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• pp.75-86
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• 2014

An urban ecosystem is a complex system that includes social, economic and ecosystems. Therefore, it is important to consider its environmental capacity while developing a city plan. Most of the plans, however, consider only the social aspects, which fragments the green spaces and disturbs the movement of species. Sungnam has approximately 100 parks with unexecuted development plans and with great potential to contribute towards urban ecosystem enhancement. Therefore, this study applied network analysis to prioritize the development of city parks and contribute towards improving the green network, with Parus spp. as the target species. To compensate for the drawbacks of binary and possibility-based network analysis, this study included two indices, namely $BC^{PC}_K$, $BC^{IIC}_K$, $dPCconnector_k$ and $dIICconnector_k$. These indices make it possible to find patches that could play an important role in green network enhancement. The urban park with greater value gets a higher priority to be transformed into a park. Thus, our methodology could prove to be very useful in prioritizing the undeveloped parks, thereby supporting decision-making.

• Journal of The Korean Digital Architecture Interior Association
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• v.10 no.1
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• pp.57-63
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• 2010

This study examines the correlations of crime-prone locations with the urban space configuration in residential district. CPTED(Crime Prevention Through Environmental Design) is applied to this study and it is intended to control the architectural environment in order to restrain criminal activities. For this reason, an objective analysis for explaining the spatial characteristics of the places where the crimes have occurred is more important than statistical and descriptive approach for analyzing the criminal data. Visibility graph analysis (VGA) supports the CPTED theory in this study for objective interpretation of crime-prone locations and quantitative analysis for built environment. The comparative analysis on object streets and areas are used and the results are followings. The analysis by streets showed that street crimes are correlated with connectivity, control, integration, and integration(r=3) and burglary cases are correlated with control. The analysis by areas showed that street crimes are correlated with connectivity and integration. The T-tests results of crime area and whole area showed that street crimes are correlated with integration and burglary cases have negative correlation with connectivity. Several localized environmental design for crime prevention are also proposed on the basis of this study.

• Journal of Information Science Theory and Practice
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• v.2 no.2
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• pp.6-15
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• 2014

Initial based disambiguation of author names is a common data pre-processing step in bibliometrics. It is widely accepted that this procedure can introduce errors into network data and any subsequent analytical results. What is not sufficiently understood is the precise impact of this step on the data and findings. We present an empirical answer to this question by comparing the impact of two commonly used initial based disambiguation methods against a reasonable proxy for ground truth data. We use DBLP, a database covering major journals and conferences in computer science and information science, as a source. We find that initial based disambiguation induces strong distortions in network metrics on the graph and node level: Authors become embedded in ties for which there is no empirical support, thus increasing their sphere of influence and diversity of involvement. Consequently, networks generated with initial-based disambiguation are more coherent and interconnected than the actual underlying networks, and individual authors appear to be more productive and more strongly embedded than they actually are.

• The Transactions of the Korean Institute of Electrical Engineers D
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• v.49 no.5
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• pp.278-286
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• 2000

A new large-scale network geometric analysis is introduced. For a large-scale circuit, it must be analyzed with a geometric diagram and figure. So many equations are induced from a geometric loop-node diagram. The results are arranged into a simple matrix, of course. In case of constructing a network diagram, it is not easy to handle voltage and current sources together. Geometric loop analysis is related to voltage sources, and node analysis is to current sources. The reciprocal transfer is possible only to have series or parallel impedance. If not having this impedance, in order to obtain equivalent circuit, many equations must be derived. In this paper a loop-reduction method is proposed. With this method current source branch is included into the other branch, and disappears in circuit diagram. So the number of independent circuit equations are reduced as much as that of current sources. The number is not (b-n+1), but (b-n+1-p). Where p is the number of current sources. The reduction procedure is verified with a geometric principle and circuit theory. A resultant matrix can be constructed directly from this diagram structure, not deriving circuit equations. We will obtain the last results with the help of a computer.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.22 no.8
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• pp.573-578
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• 2010

Topological matrix which reflects characteristics of network connectivity has been widely used in efficient solving for complicated flow network. Using topological matrix, one can easily define continuity at each node of flow network and make algorithm to automatically generate continuity equation of matrix form. In order to analyze flow network completely it is required to satisfy energy conservation in closed loops of flow network. Fundamental cycle retrieving algorithm based on graph theory automatically constructs energy conservation equation in closed loops. However, it is often accompanied by NP-complete problem. In addition, it always needs fundamental cycle retrieving procedure for every structural change of flow network. This paper proposes alternative mathematical method to analyze flow network without fundamental cycle retrieving algorithm. Consequently, the new mathematical method is expected to reduce solving time and prevent error occurrence by means of simplifying flow network analysis procedure.