• 대한기계학회논문집A
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• 제28권7호
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• pp.1038-1046
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• 2004

In order to acquire high-speed and high-precision performances in servomechanisms, an integrated design method have been proposed. Based on strict mathematical modeling and analysis of system performance according to design and operating parameters, a nonlinear constrained optimization problem including the relevant subsystem parameters of the servomechanism is formulated. Optimum design results of mechanical and electrical parameters are obtained according to the design parameters specified by designers through the integrated design processes. Motors are optimally selected from the servo motor database. Both the geometric errors referring to Abbe offset and the contour errors are minimized while required constraints such as stability conditions and saturated conditions are satisfied. This design methodology both offers the improved possibility to evaluate and optimize the dynamic motion performance of the servomechanism and improves the quality of the design process to achieve the required performance for high-speed/precision servomechanisms.

• 한국정보시스템학회지:정보시스템연구
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• 제13권1호
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• pp.77-95
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• 2004

According to the increase of organizational complexity and the change of rapid information technology environment, many firms have shifted their information technology(IT) strategy from developing information systems in-house to purchasing application software such as Enterprise Resource Planning(ERP) Systems. Marketing and Sales functions within a Korean automotive part company include developing new assembly products, determining pricing, taking customer's orders, and shipping assembly products to customers. Marketing and Sales Information System(MSIS) in ERP system plays an important role in next Production Planning process. MSIS also makes management reporting and decision making faster and more uniform throughout an organization. MSIS promotes thinking about corporate goals, as opposed to thinking only about the goals of a single department or functional area. This paper intends to design and implement a MSIS in ERP systems for Korean automotive part company using object-oriented methodology In order to accomplish the implementation of MSIS in ERP system, we employed UML as its standard modeling language. In this study, four diagramming techniques such as use case diagram, sequence diagram, class diagram, component diagram among eight modeling techniques are used for analyzing hierarchical business process. In traditional marketing and sales function, a company with an unintegrated information system can have marketing and sales data that is data redundant or inaccurate. MSIS integrated in ERP system can solve the sales forecast problem, which minimizes the total costs of production, inventory, and transportation under constraints of production capacity. Also, the use of UML methodology makes S/W programmers shorten the phase of analysis and design in the implementation of MSIS system, and increase the reuse of software and the interoperability with corporate internal Information system.

• Nuclear Engineering and Technology
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• 제51권8호
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• pp.1916-1938
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• 2019

The objective of this paper is to discuss the modeling principles of phenomena governing core degradation/melting and in-vessel melt relocation during severe accidents in light water reactors. The proposed modeling approach has been applied in the development of a new accident simulation package, COMPASS (COre Meltdown Progression Accident Simulation Software). COMPASS can be used either as a stand-alone tool to simulate in-vessel meltdown progression up to and including RPV failure, or as a component of an integrated simulation package being developed in Korea for the APR1400 reactor. Interestingly, since the emphasis in the development of COMPASS modeling framework has been on capturing generic mechanistic aspects of accident progression in light water reactors, several parts of the overall model should be useful for future accident studies of other reactor designs, both PWRs and BWRs. The issues discussed in the paper include the overall structure of the model, the rationale behind the formulation of the governing equations and the associated simplifying assumptions, as well as the methodology used to verify both the physical and numerical consistencies of the overall solver. Furthermore, the results of COMPASS validation against two experimental data sets (CORA and PHEBUS) are shown, as well as of the predicted accident progression at TMI-2 reactor.

• 인터넷정보학회논문지
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• 제5권3호
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• pp.87-98
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• 2004

일반 가입자들에게 초고속 인터넷 서비스를 제공하기 위해서 구성되는 가입자 망은ADSL, VDSL, DOCSIS 등 다양한 종류의 접속방식과 그에 따른 이기종(이기종)의 장비들로 이루어져 있다. 이러한 가입자 망은 전국적으로 분산되어 있으며, 분산된 가입자 망은 효과적이며 집중화된 형태로 관리하기 위해서는 다양한 형태의 접속방식을 지원하는 이기종 장비 및 단말들의 상위 개념으로서 추상적이며 논리적인 객체 관리모델이 필요하다. 본 논문은 통합된 계층적 망관리를 가능하게 하는 인터넷 가입자 망에 대한 모델링 구조론 RM-ODP흘 이용하여 제시하였다. 그리고 가입자 망의 예로서 UML을 이용한 객체지향 방법론을 채택하여 DOCSIS의 HFC 가입자망에 대한 관리 시스템을 설계하고 구현하였다.

• 품질경영학회지
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• 제30권4호
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• pp.58-67
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• 2002

Since the inception of off-line quality control, it has drawn a particular attention from research community and it has been implemented in a wide variety of industries mainly due to its extensive applicability to numerous real situations. Emphasizing design issues rather than control issues related to manufacturing processes, off-line quality control has been recognized as a cost-effective approach to quality improvement. It mainly consists of three design stages: system design, parameter design, and tolerance design which are implemented in a sequential manner. Utilizing experimental designs and optimization techniques, off-line quality control is aimed at achieving product performance insensitive to external noises by reducing process variability. In spite of its conceptual soundness and practical significance, however, off-line quality control has also been criticized to a great extent due to its heuristic nature of investigation. In addition, it has also been pointed out that the process optimization procedures are inefficient. To enhance the current practice of off-line quality control, this study proposes an integrated optimization model by utilizing a well-established statistical tool, so called response surface methodology (RSM), and a tolerance - cost relationship.

• International Journal of Computer Science & Network Security
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• 제21권12호
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• pp.9-20
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• 2021

Abstraction applied in computer networking hides network details behind a well-defined representation by building a model that captures an essential aspect of the network system. Two current methods of representation are available, one based on graph theory, where a network node is reduced to a point in a graph, and the other the use of non-methodological iconic depictions such as human heads, walls, towers or computer racks. In this paper, we adopt an abstract representation methodology, the thinging machine (TM), proposed in software engineering to model computer networks. TM defines a single coherent network architecture and topology that is constituted from only five generic actions with two types of arrows. Without loss of generality, this paper applies TM to model the area of network monitoring in packet-mode transmission. Complex network documents are difficult to maintain and are not guaranteed to mirror actual situations. Network monitoring is constant monitoring for and alerting of malfunctions, failures, stoppages or suspicious activities in a network system. Current monitoring systems are built on ad hoc descriptions that lack systemization. The TM model of monitoring presents a theoretical foundation integrated with events and behavior descriptions. To investigate TM modeling's feasibility, we apply it to an existing computer network in a Kuwaiti enterprise to create an integrated network system that includes hardware, software and communication facilities. The final specifications point to TM modeling's viability in the computer networking field.

• 한국컴퓨터정보학회논문지
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• 제23권2호
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• pp.45-51
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• 2018

In this paper, we propose a Designed and Developed home router management system. Through the fourth industrial revolution and development of IoT technology, now people can experience a wide range of IoT related services at their workplace or daily lives. At the industrial site, IoT devices are used to improve productivity such as factory automation, and at home, IoT technology is used to control home appliances from a remote distance. Usually IoT device is integrated and controlled by the router. Home router connects different IoT devices together at home, however when security issues arise, it can invade personal privacy. Even though these threats exist, the perception for home router security is still insufficient. In this paper, we have designed and developed home router management system using DEVS methodology to promote the safe use of home router. Through the DEVS methodology, we have designed the system and developed the mobile application. This management system enables users to set up security options for home router easily.

• 국제학술발표논문집
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• The 7th International Conference on Construction Engineering and Project Management Summit Forum on Sustainable Construction and Management
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• pp.14-23
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• 2017

In high-density high-rise cities such as Hong Kong, buildings account for nearly 90% of energy consumption and 61% of carbon emissions. Therefore, it is important to study the design of buildings, especially high-rise buildings, to achieve lower carbon emissions in the city. The carbon emissions of a building consist of embodied carbon from the production of construction materials and operational carbon from energy consumption during daily operation (e.g., air-conditioning and lighting). An integrated analysis of both types of carbon emissions can strengthen the design of low carbon buildings, but most of the previous studies concentrated mainly on either embodied or operational carbon. Therefore, the primary objective of this study is to develop a holistic methodology framework considering both embodied and operational carbon, in order to enhance the sustainable design of low carbon high-rise buildings. The framework will be based on the building information modeling (BIM) technology because BIM can be integrated with simulation systems and digital models of different disciplines, thereby enabling a holistic design and assessment of low carbon buildings. Structural analysis program is first coupled with BIM to validate the structural performance of a building design. The amounts of construction materials and embodied carbon are then quantified by a BIM-based program using the Dynamo programming interface. Operational carbon is quantified by energy simulation software based on the green building extensible Markup Language (gbXML) file from BIM. Computational fluid dynamics (CFD) will be applied to analyze the ambient wind effect on indoor temperature and operational carbon. The BIM-based framework serves as a decision support tool to compare and explore more environmentally-sustainable design options to help reduce the carbon emissions in buildings.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2008년 영문 학술대회
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• pp.311-319
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• 2008

We present an innovative method of multi physics application involving energetic materials. Energetic materials are related to reacting flows in extreme environments such as fires and explosions. They typically involve high pressure, high temperature, strong shock waves and high strain rate deformation of metals. We use an Eulerian methodology to address these problems. Our approach is naturally free from large deformation of materials that make it suitable for high strain rate multi-material interacting problems. Furthermore we eliminate the possible interface smearing by using the level sets. We heave devised a new level set based tracking framework that can elegantly handle large gradients typically found in reacting gases and metals. We show several work-in-progress application of our integrated framework.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2000년도 봄 학술발표회논문집
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• pp.397-404
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• 2000

The research of the computer-aided analysis and design of steel structures has continuously evolved. Despite the importance of connection in steel structures, the design process of connections is inefficient in present. The purpose of this study is to help engineer in connection design process. In this paper, prototype of automatic connection design module in integrated system for steel structures is proposed. The main methodology is based on bottom-up approach to simplify and formalize product model. Expert system is used to help engineer for selecting steel connection type. Object-oriented analysis and modeling will improve the expansion of knowledge-base. The design for connection was done according to the design specifications of connections of AISC