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

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

• Proceedings of the Korean Society for Language and Information Conference
• /
• 2002.02a
• /
• pp.177-186
• /
• 2002

Korean predicative verb forms obligatorily denote the three categories speech level, mood and sentence type which are not handled by most of the automatic word form recognition systems for this language. These categories are marked by special endings. This paper examines predicative verb forms concentrating on the lexical description of these endings in the framework of Left-Associative Grammar (LAG). Additionally this paper suggests a system to analyse verb forms in these aspects. The results of this study have been implemented using Malaga$^2$ and integrated into an automatic word form recognition system for Korerin called KMM (Korean Malaya Morphology).

• Journal of Korean Institute of Industrial Engineers
• /
• v.28 no.1
• /
• pp.1-13
• /
• 2002

We study a multi-component production/inventory system in which individual components are made to meet various demand types. We assume that the demands arrive according to a Poisson process, but there is a fixed probability that a demand requests a particular kit of different components. Each component is produced by a flow line with several stations. The production of each component is operated by the CONWIP control mechanism. To analyse this system, we propose an approximation method based on aggregation method. In application of the aggregation method, a product-form approximation technique as well as a matrix-geometric method is used. Comparisons with simulation show that the approximation method provides fairly good results.

• 한국전산유체공학회:학술대회논문집
• /
• 1995.10a
• /
• pp.43-48
• /
• 1995

A numerical computation is carried out to analyse characteristics of flow fields around Air Supported Ships having arbitrary form. The computations are performed in a rectangular grid system with MAC(Marker And Cell) method. The governing equations are represented in a Finite Difference form by forward differencing in time and centered differencing in space except for convection terms. For validation of this numerical analysis method, the computation of flow fields around Catamaran and ACV(Air Cushion Vehicle) with pressure distribution on free surface are done, and that around Surface Effect Ship is also carried out. The results of the computations are compared with the those of existed numerical computation and experimental results with the same condition.

• Journal of Korean Association for Spatial Structures
• /
• v.13 no.1
• /
• pp.59-67
• /
• 2013

This paper presents a new numerical method to analyse tensegrity structures by using singular value decomposition and force method. The tensegrity system consisting of compressive and tensle elements are pin-jointed system. Tensegrity structures, unlike the general structure should be preceded by form-finding. Tensegrity structures form-finding of the self-equilibrium stress stability, seeking to have the process. In this study, tensegrity structures when subjected to external loads, find the optimal pre-stress values was studied.

• Journal of the Korean Home Economics Association
• /
• v.37 no.1
• /
• pp.1-13
• /
• 1999

The purpose of this study is to find how the mate selection and sex consciousness reflected in Samhuk Yusa. We set up the following two questions for aim of this study. First, how are the real aspects and specific characters of mate selection reflected in Samguk Yusa? Second, how are the real aspects and specific characters of sex consciousness reflected in Samguk Yusa? The results can be summarized as follows; 1. Mate selection reflected in Samguk Yusa discussed into two major domains, one is spouse conditions and the other is marriage form. Men and Women are married at teenages, but the greater part of case is unidentified, so in order to approach this we need to analyse other historical documents. In men and women, standard of appearance and personality is difference. Analyzed case about appearance is a few, also we need to analyse other historical materials. More valued personality is wisdom in men, and in women more valued personality is virtue, brightness, graceful and mild. Through in case of to overcome the cultural gabs, the society must be open in every area. The marriage form is diversity, examples, free marriage, a marriage of convenience type, etc. Especially in aspects remarriage of man and woman is free in every class. 2. Sex consciousness reflected in Samguk Yusa discussed into three major domains, first is discussion about sex, second is premarital sexual behavior, third is extramarital. Through the case of discussion about sex is opened so there is not existence double blinded in sexual norms. Also through the case of premarital sexual behavior and extramarital, fidelity ideology does not yet come into existence.

• The Research Journal of the Costume Culture
• /
• v.18 no.5
• /
• pp.872-891
• /
• 2010

This study was an exploratory research to classify the types of green fashion marketing of the fashion companies in South Korea and analyse the present cases of each type. To analyse the current cases of green fashion marketing strategies, we researched all sorts of newspapers, magazines, publications of fashion companies, and web sites from 2008 to 2009. As a result, we categorized 5 types of green fashion marketing as follows ; eco-friendly fabrics (natural fabrics, recycled fabrics, biodegradable fabrics), re-use or re-form(reuse after cleaning and/or repairing and reformation through transformation and combination of raw materials), green certifications(ISO 14001, GOTS, OES, etc.), eco-friendly management and operation, and green marketing promotions. Based on the results, we proposed the green marketing strategies for fashion companies to progress toward the proper direction of green marketing. First of all, companies should escape from the narrow view point limited to the product itself. Then they have to focus on developing and execution of sustainable merchandising, manufacturing, logistics, and waste strategies.

• The Transactions of the Korean Institute of Electrical Engineers B
• /
• v.54 no.9
• /
• pp.403-407
• /
• 2005

Most of the loads in industrial power distribution systems are balanced and connected to three power systems. However, voltage unbalance is generated at the user's 3-phase 4-wire distribution systems with single & three phase. Voltage unbalance is mainly affected by load system rather than power system. Unbalanced voltage will draws a highly unbalanced current and results in the temperature rise and the low output characteristics at the machine. It is necessary to analyse correct voltage unbalance factor for reduction of side effects in the industrial sites. Voltage unbalance is usually defined by the maximum percent deviation of voltages from their average value, by the method of symmetric components or by the expression in a more user-friendly form which requires only the three line voltage readings. If the neutral point is moved by the unbalanced load at the 3-phase 4-wire system. Line and phase voltage unbalance leads to different results due to zero-sequence component. So that it is difficult to analyse voltage unbalance factor by the conventional analytical method, This paper presents a new analytical method for phase and line voltage unbalance factor in 4-wire systems. Two methods indicate exact results.

• Journal of the Korean School Mathematics Society
• /
• v.9 no.2
• /
• pp.195-208
• /
• 2006

Among different geometrical representations of a mathematical concept, learners are likely to form their geometrical concept image of the given concept based on a specific one. A learner's image is not always in accord with the definition of a concept. This can induce his or her errors in mathematical problem solving. We need to analyse types of such errors and the cause of the errors. In this study, we analyse learners' geometrical concept images for geometrical concepts and errors related to such images. Furthermore we propose a theoretical framework for error analysis related to a learner's concept image for a general mathematical concept in mathematical problem solving.