• The Transactions of the Korean Institute of Electrical Engineers A
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• v.54 no.2
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• pp.67-72
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• 2005

In conventional small signal stability analysis, system is assumed to be invariant and the state space equations are used to calculate the eigenvalues of state matrix. However, when a system contains switching elements such as FACTS devices, it becomes non-continuous system. In this case, a mathematically rigorous approach to system small signal stability analysis is by means of eigenvalue analysis of the system periodic transition matrix based on discrete system analysis method. In this paper, RCF(Resistive Companion Form) method is used to analyse small signal stability of a non-continuous system including switching elements. Applying the RCF method to the differential and integral equations of power system, generator, controllers and FACTS devices including switching elements should be modeled in the form of state transition equations. From this state transition matrix eigenvalues which are mapped to unit circle can be calculated.

• Steel and Composite Structures
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• v.13 no.1
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• pp.1-13
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• 2012

In this study, a new structural bracing system named 'Hat Knee Bracing' (HKB) is presented. In this structural system, a special form of diagonal braces, which is connected to the knee elements instead of beam-column joints, is investigated. The diagonal elements provide lateral stiffness during moderate earthquakes. However the knee elements, which is a fuse-like component, is designed to have one plastic joint in the knee elements for dissipation of the energy caused by strong earthquake. First, a suitable shape for brace and knee elements is proposed through elastic studying of the system and several practical parameters are established. Afterward, by developing applicable and highly accurate models in Drain-2DX, the inelastic behavior of the system is carefully considered. In addition, with inelastic study of the new bracing system and comparison with the prevalent Knee Bracing Frame system (KBF model) in nonlinear static and dynamic analysis, the seismic behavior of the new bracing system is reasonably evaluated.

• Korean Institute of Interior Design Journal
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• v.14 no.6 s.53
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• pp.168-176
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• 2005

This study is a understanding on technological specific expression to reflect of a research institute in modern architecture. For this study, it separately reduce space program, plan program, design elements of elevation, structural system, mechanical system, building material program to its expressional elements of research institute. Also, it's arranged about a specificity that is expressed for technology each plan elements of a research institute. As a result, elements what is expressive of technology on research institute are influenced an aesthetic expression, expression of an arrangement system, structural expression, expression of architectural organization, and it influences more getting feels technological specificity expressed an aesthetic, structural system, architectural composition, mechanical distribution system in order of their magnitude. This is offered suggestion what must be an achievable complex both a simply technological expression and aesthetic expression.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.21 no.5
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• pp.800-808
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• 1997

Decision process for length dimension in the mechanical system design process has been studied with a washing machine transmission as a model. The results are, (i) the length dimensions of the non-shaft elements are independent of other elements, (ii) the length dimensions of the shaft elements are dependent on the dimensions of the non-shaft elements located inside and outside of that elements, (iii) the length dimensions of the inner shaft elements are dependent on those of the outer shaft elements located parallel, (iv) the length dimensions of the shaft elements located serial are independent of each other.

• KIEAE Journal
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• v.16 no.3
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• pp.35-46
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• 2016

Purpose: This paper aims to analyse the composition system of architectural elements including shape, kinetic and material elements of kinetic facades and establish the design parameter system as a common conceptual and practical knowledge sharing platform with mechanical and electrical experts. Method: This research has been conducted in a three steps. At first, 120 cases of external shading devices are analyzed and their classification criteria have been established. Secondly geometric, kinetic and material elements are categorized in a common kinetic facade coordinates system considering environmental effects and operation method, and the applicability of combination of each element are tested. Lastly core design parameters for each element have been established in a common office building installation coordinate. Result: Geometry elements are categorized into seven geometric shapes and kinetic elements is categorized into basic linear and rotational motion and combinational folding and rolling motion. The combined set of parameters for three elements composes the whole design parameters for architectural elements of kinetic façade. Design parameters of shape elements are composed of shape, installation and arrangement parameters; design parameters for kinetic elements are composed of axis and range parameters; and design parameters of material elements are composed of thermal, lighting and color parameters.

• Journal of Korean Society for Quality Management
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• v.44 no.4
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• pp.713-733
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• 2016

Purpose: The primary objective of this case study is to establish a COQ(Cost of Quality) management system for power generation industries. Key topics of this study include collecting COQ elements, their classifications, COQ computation formula, and determining COQ improvement projects. Results: A comprehensive set of COQ elements have been isolated for electric power generation companies. The COQ elements were classified in such a way that they could be managed according to the PAF model as well as the SIPOC diagram. This study showed that a systematic approach could be established for monitoring the COQ elements and using them in the process of improving quality competitiveness. Methods: The PAF(Prevention-Appraisal-Failure) model has been employed in the process of collecting COQ elements for a power generation company. All the cost of quality elements were first examined through an extensive review of articles and books in the field of quality. The cost elements were then refined and augmented by conducting a comparative study with international standards. The COQ elements have been verified by a group of quality managers and classified according to both the PAF model and the SIPOC diagram for better understanding in the entire organization. An improvement strategy has been also proposed by using a typical COQ level of power generation companies. Conclusion: The conventional PAF model was used in establishing a COQ management system for power generation industries. This case study illustrates the procedure about identification, classification and computation of quality costs, including selection of improvement projects. The system can be used not only for observing the current state of cost elements related to quality, but also for planning an improvement strategy using the ratio of cost classification.

• Korean Institute of Interior Design Journal
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• v.14 no.1
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• pp.64-72
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• 2005

The purpose of this study was to analyze the flexible system in a typological way that develops and promotes the various methods of flexible system. The main method of this study was literature review and content analysis on various flexible systems and a case study of flexible housing. The flexible system in this typological analysis was classified into two categories: 'Elements of Flexibility' and 'Variation'. The category of Flexibility Elements was categorized into 'Primary Elements'(e.g., walls, floors, and ceilings),'Secondary Elements'(e.g., doors, windows, and furniture), and 'Tertiary Elements'(e.g., lighting, hues and finishing materials). Variation Effect was classified into 'Visual Variation', 'AppBicative Variation', and 'Layout Variation'. Also, Variation could be classified into 'Finish-centered', 'Application-centered', and 'Layout-centered' The flexible system developed in this study is a basis for further concrete flexible methods.

• Journal of Korea Multimedia Society
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• v.24 no.9
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• pp.1299-1310
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• 2021

Under the background of the rapid development of digital educational games, we have to evidently research the elements of the achievement system of children's DEG (Digital Educational Game), and analyze the relations between the elements and make a profound study on the achievement system and its components on the impact of player's attitude. Compared with the existing research, the research contents and methods are innovative and reliable. The results show that players have a positive attitude towards the DEG achievement system, DEG achievement system has important value and role for educational games. Which is made of five elements: symbol, reward, logic, social interaction, and knowledge. The five elements interact with each other and have a positive impact on players' attitudes. DEG achievement system with five elements will bring players a positive experience. These findings provide a detailed study of the components of the achievement system. With all of these, we can explain the role and relationship of the components, and provide new ideas and empirical evidence for the design and development of children's educational game achievement system. The above findings provide a detailed description of the components of the DEG achievement system, explain the role and value of each component, and the relationships and patterns among the components, it provides a new perspective and empirical evidence for the design and development of the children's system DEG results.

• KIEE International Transactions on Power Engineering
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• v.5A no.4
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• pp.344-349
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• 2005

In conventional small signal stability analysis, the system is assumed to be invariant and the state space equations are used to calculate the eigenvalues of the state matrix. However, when a system contains switching elements such as FACTS equipments, it becomes a non-continuous system. In this case, a mathematically rigorous approach to system small signal stability analysis is performed by means of eigenvalue analysis of the system's periodic transition matrix based on the discrete system analysis method. In this paper, the RCF (Resistive Companion Form) method is used to analyze the small signal stability of a non-continuous system including switching elements. Applying the RCF method to the differential and integral equations of the power system, generator, controllers and FACTS equipments including switching devices should be modeled in the form of state transition equations. From this state transition matrix, eigenvalues that are mapped into unit circles can be computed precisely.

• Proceedings of the KIEE Conference
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• summer
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• pp.342-344
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• 2004

In conventional small signal stability analysis, system is assumed to be invariant and the state space equations are used to calculate the eigenvalues of state matrix. However, when a system contains switching elements such as FACTS devices, it becomes non-continuous system. In this case, a mathematically rigorous approach to system small signal stability analysis is by means of eigenvalue analysis of the system periodic transition matrix based on discrete system analysis method. In this research, RCF(Resistive Companion Form) method is used to analyse small signal stability of a non-continuous system including switching elements'. Applying the RCF method to the differential and integral equations of power system, generator, controllers and FACTS devices including switching elements should be modeled in the form of state transition matrix. From this state transition matrix eigenvalues which are mapped to unit circle can be calculated.