• 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.

• Journal of Korean Library and Information Science Society
• /
• v.14
• /
• pp.217-240
• /
• 1987

The purpose of this study is to analyse the current theses acquisition in university libraries and to suggest some useful findings for the more efficient acquisition of the theses. The results of the study can be summarized as follows (1) Depositary copies of each thesis in the libraries should be increased. (2) Under cooperative efforts, libraries must establish the exchange system of the theses by region or subject or characteristics of universities. (3) Each library should set up concrete selection criteria for the receiving of theses. (4) Development of purchase system would be necessary for economic and prompt acquisition of theses. (5) Theses should be microformed so as to save their storage space. (6) To give su n.0, pport to effective acquisition activity, various bibliographies about theses should be published.

• 제어로봇시스템학회:학술대회논문집
• /
• 1996.10b
• /
• pp.482-485
• /
• 1996

We design a homing guidance law based on the proportional navigation for the fast-rolling, single-axis control missiles and analyse the misdistance of the designed guidance system. The guidance law includes a compensation scheme which compensates for the phase-shift between the commanded and achieved acceleration which is peculiar to the fast rolling airframe with single-axis control. In the error analysis of the guidance system, we calculate the misdistance with respect to the target maneuver on the 3-dimensional space via direct simulations. Also, we conduct adjoint simulation on the 2-dimensional plane in case that phase-shift is perfectly compensated. Finally we approximate the linear time-varying dynamics of the missile with autopilot to a linear time-invarient system, and as a result we can find the misdistance as a closed-form.

• Journal of the Korean housing association
• /
• v.17 no.1
• /
• pp.67-75
• /
• 2006

Multi-family housings caused several problems related to physical form such as isolation of housing estate, inhumanity of the exterior space, and mismatch with the urban structure. To handle these problems, the purpose of this study is to analyse density elements which have a direct impact on physical forms, thereby understand the characteristics of physical form and also identify a meaning of inter-relationships between them. Therefore both formal constituents and density elements are reformed into respective analyzing indices. From the analysis, physical form and the spatial layout of buildings were more uniform in large-scale housing estates than in medium or small housing estates. However, small-scale housing estates showed various form and the spatial layout of buildings in order to increase the building density.

• Journal of the Korean housing association
• /
• v.14 no.1
• /
• pp.29-40
• /
• 2003

The purpose of this research is to document and analyse spatial transformation of an unauthorized dwelling units on a peculiar site of Seoul. It's physically attached to the behind part of the west boundary wall of Chang-Duk Palace. These dwelling units took not only the site, the narrow street which had been a stream, but also the two parallel walls of others for their home. The two walls, one from the palace wall and the other from the wall of a house which distanced itself from the palace wall about 3.5 m for the reason of the Cultural Properties Protection Law, have been held as the main structural members in forming the shelter. With examining the realm of time which provide the base of the spatial realm, this research shows how the multiple linkages tangled in an illegal shack did gain and actualize an architectural language of idiosyncrasy with spontaneous order inherent in inhabitants.

• KIEAE Journal
• /
• v.3 no.1
• /
• pp.37-44
• /
• 2003

The purpose of this study is to analyse the attitude of Environmental Friendly Factors for proper environmental friendly model that is adapted to whole life-space. For this study, 25 factors were used from published thesis, reports, and news items. etc.. The results of this study are that our environmental problem is more serious than the world. The respondents prefer natural environmental friendly factors to artificial. Further study of environmental friendly planing will make rapid progress not only housing estates but other building for factory, entertainment establishment, and office building.

• 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.

• 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 the Korean housing association
• /
• v.8 no.3
• /
• pp.131-139
• /
• 1997

The purpose of this study is to analyse the housing values of the university student. The data is collected through the self-entry questionnaire that designed for this study. The 512 data obtained were analysed by Frequencies. Mean, Factor analysis, t-test, oneway ANOVA, $\chi$$^2$-test. Duncan's Multiple Range Test. The major findings are as follows: 1) The Housing Value was classified of 5 factors which Location-Environment. Social - Psychology, Physical factor of Housing, Life-Conciousness and Investmental of Value. 2) Their relevance variables of Housing value were sex, the educational course and occupation of their father and income. 3) Their preference trend of Housing appeared to the apartment and One-room system, and green tract of the space etc.

• Computers and Concrete
• /
• v.14 no.1
• /
• pp.41-57
• /
• 2014

Modern trend in structural design is to use smaller elements in order to ensure several purposes such as economy, functionality and aesthetic in appearance. However, because of decreasing rigidity of the structural elements, the system displacements increases and displacements become an important subject in this kind of structures takes into account both geometrical changes and the carrying capacity of the material after linear-elastic boundary. In this study, a method is proposed to calculate the failure loads and to analyse the reinforced concrete space frame systems. The numerical examples gathered from the literature survey are solved with this method utilising the prepared computer program and the comparable results are presented. The results show that the method is sufficiently accurate.