• Transactions of the Korean Society of Mechanical Engineers A
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• v.33 no.9
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• pp.892-902
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• 2009

An efficient sequential optimization approach for metamodel was presented by Choi et al. This paper describes a new approach of the multilevel optimization method studied in Refs. [2] and [20,21]. The basic idea is concerned with multilevel iterative methods which combine a descent scheme with a hierarchy of auxiliary problems in lower dimensional subspaces. After fitting a metamodel based on an initial space filling design, this model is sequentially refined by the expected improvement criterion. The advantages of the method are that it does not require optimum sensitivities, nonlinear equality constraints are not needed, and the method is relatively easy to understand and use. As a check on effectiveness, the proposed method is applied to an engineering example.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.30A no.10
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• pp.67-76
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• 1993

This paper presents the design and implementation of SVSIM (Sogang VHDL SIMulator), a multi-level VHDL simulator, designed for the construction of an integrated VGDL design environment. The internal model of SVSIM is the hierarchical C/DFG which is extended from C/DFG to include the network hierarchy and local/glabal control informations. Hierarchical network is not flattened for simulation, resulting in the reduction of space complexity. The predufined/user-defined types except for the record type and the predefined/user-defined attributes are supported in SVSIM. Algorithmic-level descriptions can be siumlated by the support of recursive procedure/function calls. Input stimuli can be generated by command script in stimuli file or in VHDL source code. Experimential results show SVSIM can be efficiently used for the simulation of the pure behavioral descriptions, structural descriptions or mixture of these.

• Journal of the Korean housing association
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• v.16 no.5
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• pp.83-90
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• 2005

This study aimed to examine the possibility of remodeled nursing home utilizing a closed school in Kunsan, where the number of closed schools increases and the ratio of elderly population grows. Major contents of research were understanding architectural characteristics of closed school and elderly housing in the sample area, and a suggestion of remodeling a closed school into nursing home. Conclusions can be summarized as follows; understanding the high ratio of elderly population and increases of closed schools in sample area, verification of overall possibility in remodeling a closed school into elderly facility, confirmation of availability in changing regular class room to residential rooms, and some proposals of principal points in floor planning - homelike atmosphere by small scaled residential units(10 persons), spatial hierarchy for residents' mental comfort, sliding door for accessibility, kitchen and dining space in residential unit for the residents' participation in houseworks.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2003.05a
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• pp.999-1006
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• 2003

This research presents efficient operation schemes that is emphasized on mailing center's automation parts. We utilized the automation indicator to analyzed the mailing center system. For automation of the mailing center, we proposed the sorting automation alternative of registered mail, automation of conveyance system between workshops and the Up-Grade scheme for process improvement in mailing center. The selection of the registered mailing f s automation alternatives is composed of the AHP(Analytic Hierarchy Process) method. Through the analysis of the space and the quantity of materials, the simulation experiments are conducted to examine conveyance equipment possibility of the mailing center. By simplifying the mailing center conceptually, we proposed the upgrade of process for the mailing center system. The result of this research can give some ideas to people who are formulating a policy for the mailing center operation.

• Proceedings of the KSRS Conference
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• 2008.10a
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• pp.406-409
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• 2008

Clustering data streams has an importance over many applications like sensor networks. Existing hierarchical methods follow a semi fuzzy clustering that yields duplicate clusters. In order to solve the problems, we propose an extended online divisive agglomerative clustering on data streams. It builds a tree-like top-down hierarchy of clusters that evolves with data streams using geometric time frame for snapshots. It is an enhancement of the Online Divisive Agglomerative Clustering (ODAC) with a pruning strategy to avoid duplicate clusters. Our main features are providing update time and memory space which is independent of the number of examples on data streams. It can be utilized for clustering sensor data and network monitoring as well as web click streams.

• Proceedings of the KSME Conference
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• 2008.11a
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• pp.1198-1203
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• 2008

An efficient sequential optimization approach for metamodel was presented by Choi et al [6]. This paper describes a new approach of the multilevel optimization method studied in Refs. [5] and [21-25]. The basic idea is concerned with multilevel iterative methods which combine a descent scheme with a hierarchy of auxiliary problems in lower dimensional subspaces. After fitting a metamodel based on an initial space filling design, this model is sequentially refined by the expected improvement criterion. The advantages of the method are that it does not require optimum sensitivities, nonlinear equality constraints are not needed, and the method is relatively easy to understand and use. As a check on effectiveness, the proposed method is applied to a classical cantilever beam.

• Journal of Korean Society of Rural Planning
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• v.6 no.1 s.11
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• pp.44-49
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• 2000

The purpose of this study is to develop a rural stream environment management system (RUSEMS) using Object Oriented Programming (OOP). In this study, the management goals of RUSEMS were conceptualized and systemized. The objects which required in RUSEMS were developed, then the method and the attribute of the objects were also devised, and the hierarchy of the objects was constructed by OMT method in this study. The results of the system application showed that RUSEMS was enable to manage, to analyze, and to offer the information about the monitoring, analyzing of the rural stream pollution, and managing pollution source of the watershed and the rural stream environment management for the friendly water space.

• Journal of the Korea Safety Management & Science
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• v.1 no.1
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• pp.159-169
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• 1999

This paper applies the Analytic Hierarchy Process(AHP) to analyzing the causes and countermeasures of the accidents by the dangerous machines. The AHP is the decision supporting tool considering several objectives and criteria, and synthesizing a number of decision makers' opinions to find the best alternative. It has the merit to be able to consider not only quantitative factors but also qualitative factors. Because this paper focuses the thoughts of the workers about the dangerous factors in working space including machines, work environment and tools, the AHP is the most suitable method for this study. This study using the AHP can be used as useful tool analyzing the important causes of the accidents by the dangerous machines and deciding the urgent countermeasures.

• Journal of information and communication convergence engineering
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• v.1 no.2
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• pp.82-87
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• 2003

We are able to work on the shared virtual space in Web-based Collaborative Design System using only Internet and Web browser. Then the users will share 3D objects and must be able to pick the objects effectively which they want to manipulate. In this paper, picking is implemented not only by computing intersection of mouse pointer with the objects of the virtual world, but also by using capabilities and attributes of scene graph node, by setting bounds intersection testing instead of geometric intersection testing, by limiting the scope of the pick testing, using Java 3D. These methods can reduce the computation of picking and can pick 3D objects effectively and easily using the system of hierarchy.

• Proceedings of the Korean Society of Rural Planning Conference
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• 1998.10a
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• pp.12-15
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• 1998

The purpose of this study is to develop a rural stream environment management system (RUSEMS) using Object Oriented Programming (OOP). In this study, the management goals of RUSEMS were conceptualized and systemized. The objects which required in RUSEMS were developed, then the method and the attribute of the objects were also devised, and the hierarchy of the objects was constructed by OMT method in this study. The results of the system application showed that RUSEMS was enable the manager of the rural stream to analyze and offer the information about the monitoring and analysis of the rural stream pollution, the management of the watershed pollution source and the rural stream environment management for the friendly water space.