• KIEE International Transactions on Power Engineering
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• 제4A권3호
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• pp.134-140
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• 2004

This paper presents an improved group of energy functions reflecting generator damping effects for multi-machine power systems by using Center of Inertia (COI) formulation as an extension of the previous work. Since rotor angles at the Stable Equilibrium Point (SEP) of post-fault systems are generally calculated in COI, system transient energy can be found without assumption of infinite or slack bus, which is a crucial drawback of the absolute rotor angle frame approach. The developed energy functions have a structure preserving property with which it is very flexible to incorporate various models of power system components, especially various load and generator models. The proposed damping-reflected energy functions are applied to the Potential Energy Boundary Surface (PEBS) method, one of the direct methods. Numerical simulation of WSCC 9-bus shows that conservativeness of the PEBS method can be considerably reduced.

• 대한안전경영과학회:학술대회논문집
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• 대한안전경영과학회 2001년도 추계학술대회
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• pp.151-155
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• 2001

This paper presents the interrelationship chart between software quality characteristics and engineering attributes. The software quality characteristics and their subcharacteristics are excerpted front IS0/1EC 9126 standards, and the engineering attributes are from Deutsch and Willis[4]. Based on the previous studies and subjective judgement, trisected interrelationship(strong, medium, weak) between these two groups are derived. The results are summarized in a table, and can be used as a quick reference guide to the software quality engineering applications such as quality evaluations for software products, selection of key engineering attributes for high-quality software production, and so forth.

• International Journal of Naval Architecture and Ocean Engineering
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• 제6권4호
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• pp.1111-1129
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• 2014

A 9300 TEU container carrier was equipped in 2006 with instrumentation aimed at wave induced accelerations, and motions. In 2010 the system was extended with strain sensors to include structural loads. Section loads for vertical bending could be readily obtained but the originally intended derivation of horizontal bending and torsion from the measured strains was found to be unreliable. This paper addresses an alternative approach that was adopted in the post processing of results. In particular the concept to use acceleration sensors to capture global hull deformations along the length of the hull, and the use of a data fusion procedure to obtain section loads from combined sensor data and finite element calculations. The approach is illustrated by comparison of actually measured accelerations and local strains with values obtained from the data fusion model. It is concluded that the approach is promising but in need of further validation and development. In particular the number and shapes of the modes used may not have been sufficient to represent the true deflection and thus strain distributions along the high loaded areas.

• 동국한의학연구소논문집
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• 제4권
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• pp.147-160
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• 1995

The aim of this studies was to elucidate the derivation, meaning and use of the special points of MADANYANG. The results obtained were as follows : The remedial cases of special points of MADANYANG came within the category in that of literature cited. So, it was considerable that a method of selection of remedial points in MADANYANG was not creative but universal at that time. The special points of MADANYANG did not have a fixed organizing rule against it's medrian, visera and bowel in contrast to source points, connecting points, five element points etc. And it was only organized on the basis of remedial value.

• 전산구조공학
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• 제11권4호
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• pp.187-196
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• 1998

불연속 갤러킨 정식화에 기초를 둔 시간적분법에 대하여 시간을 변수로 한 유한요소적 접근법을 시도하였다. 단일 형상함수와 두 형상함수 정식화에 대해 각각 선형, 이차 형상함수를 적용하여 모두 네 종류의 시간적분법을 유도하였으며, 각 방법에 대하여 시간시텝의 증가에 따른 변위와 속도의 관계를 나타내는 증폭행렬을 계산하였다. 유도된 방법들의 성능을 평가하기 위하여 부하가 갑자기 변화는 진동 문제를 해석하고 변위의 오차를 비교하였다. 네 가지의 방법에 대하여 국부 오차 추정치를 개발하였으며, 오차 추정치의 정확도를 수치예를 이용하여 평가하였다. 단일 형상함수 정식화에서 이차 형상함수를 이용한 오차 추정치가 실제 국부오차를 잘 나타내었으며 유도된 오차 추정치는 시간간격제어 기법에서 시간간격의 크기를 결정하는 척도로 이용 가능하다.

• Kyungpook Mathematical Journal
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• 제47권4호
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• pp.529-548
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• 2007

The purpose of this article is to find a relation between the finite difference method and the boundary element method, and propose a new approach deriving a discrete approximation formula as like that of the finite difference method for harmonic functions. We develop a discrete approximation formula on a uniform grid based on the boundary integral formulations. We consider three different boundary integral formulations and derive one discrete approximation formula on the uniform grid for the harmonic function. We show that the proposed discrete approximation formula has the same computational molecules with that of the finite difference formula for the Laplace operator ${\nabla}^2$.

• 가족자원경영과 정책
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• 제4권1호
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• pp.15-28
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• 2000

The purpose of this study was to examine the knowledge about savings of customers who utilize Investment Trust Company and to analyze the factors affecting it. The data for the analysis were collected by structured questionnaires and consisted of 191 customers who utilize Investment Trust Company. Descriptive. Descriptive Statistics including percentage, frequency, means, and standard derivation, t-test, one-way ANOVA with Scheffe test, multiple regression analysis were used to analyze the data. The following is a summary of major findings. 1) The customers knowledge about savings showed generally low-level. Especially the knowledge about tax and regulation of savings were the areas shown the lowest level. 2) The age, marital status, education and occupation of customers and total period of utilizing company were the factors affecting the knowledge of customers in the one-way ANOVA analysis. 3) The result of regression analysis indicated that age of customers and total periods of utilizing company were the significant predictors of customers’knowledge. These two variables explained 25.77% of variance of customers’knowledge about savings.

• Journal of Advanced Marine Engineering and Technology
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• 제23권4호
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• pp.583-592
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• 1999

In order to control systems which contain nonlinearities control strategies must deal with the effects of them. Since most of control methods based on system mathematical models have been mainly developed focused on stability robustness against nonlinearities or uncertainties under the assumption that controlled systems are linear time invariant they have certain amount of limita-tions to smartly improve control perfomances of systems disturbed by nonlinearities or uncertainties. In this paper the fuzzy PID control law is suggested which can improve control performances of the nonlinear heavy load hydraulic systems disturbed by nonlinearities and uncertainties. Although the derivation process is based on the design process similar to general fuzzy logic con-troller resultant control law has analytical forms with time varying PID gains rather than linguis-tic forms so that implementation using commn-used versatile microprocessors can be achieved easily and effectively in real-time control aspect.

• 통합자연과학논문집
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• 제1권1호
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• pp.1-4
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• 2008

We developed quantification method based on the concept of candela in physics. The measurement of fluorescence signal from a nude mouse in the research of molecular biology. In the measurement of the optical signal with CCD, the quantification method for photon counts based on bio-luminescence imaging technique can provide comparative reference data. In this paper, we described theoretical derivation of our proposed concept. We hope this method could be a useful standard reference for quantitative date analysis in optical imaging.

• 한국결정학회지
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• 제13권2호
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• pp.73-81
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• 2002

Triclinic system에는 2개의 point group들 1,(equation omitted), 그리고 monoclinic system에는 3개의 point groups, 2, m, 2/m 가 있는데/sup 1)/ point group들 1, 2, m은 polar point group이고 이 중의 1, 2는 enantiomorphous point group이며 point group들 (equation omitted)와 2/m은 centric point group으로 Laue group이라 일컬어진다./sup 2-4)/ 본 해설문에서는 point group들 1, (equation omitted)에서 나오는 2개의 space group들과 point group들 2, m, 2/m에서 유도되는 13개의 space group들의 좌표들을 유도하였다 . Monoclinic system에서는 unique axis b 만을 다루었고, 그리고 space group No. 14은 3가지로 해석하였으며 나머지는 standard space group만을 다루었다. 모든 space group diagram은 “International Tables for Crystallography, Volume A edited by Theo Hahn, Third revised edition published for The International Union of Crystallography by Kluwer Academic Publishers, 1992”에 기재되어 있다.