• Title/Summary/Keyword: analysis methods

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Analysis and Reduction Methods of Sheath Circulating Current in Underground Transmission Systems (지중송전계통에서 시스순환전류 해석 및 저감방안)

  • Jeong, Chae-Gyun;Lee, Jong-Beom;Gang, Ji-Won;Jang, Tae-In
    • The Transactions of the Korean Institute of Electrical Engineers A
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    • v.50 no.11
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    • pp.537-545
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    • 2001
  • This paper describes the analysis of sheath circulating current and various methods to reduce the large circulating current in case of operating cable system using EMTP/ATPDraw. And also, possible methods are proposed through a detailed analysis regarding cable systems by considering various electrical and environmental factors. It is evaluated that the proposed reduction methods can be effectively applied to reduce the large sheath circulating over current with the minimized electrical problems.

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Comparisons of Empirical Methods with Numerical Analysis on Lateral Flow in Soft Soils (측방유동에 관한 경험식 및 수치해석의 비교)

  • Kim Dae-Kyu
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.7 no.4
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    • pp.665-670
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    • 2006
  • In this paper, the results of empirical methods and the numerical analysis were compared and investigated on the lateral displacement due to embankment in soft soil. The empirical methods gave different results so the possibility of lateral displacement could not be determined only by the empirical methods. The numerical analysis could be used so effectively that its result showed useful lateral and vertical displacements with depth and distance.

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Development of a Tool to Support Learning Tasks Analysis Using the Knowledge Space Theory (지식공간론을 활용한 학습과제분석 지원도구의 개발)

  • Jo, Hyeong-Cheol;Lim, Jin-Sook;Kim, Seong-Sik
    • The Journal of Korean Association of Computer Education
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    • v.7 no.1
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    • pp.129-139
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    • 2004
  • This society is rapidly changing into an information-oriented society. As such, revolutionary and efficient teaching methods are needed in school education rather than traditional methods. To be an efficient teaching lesson, teaching plans based on learners' prior knowledge are needed. The knowledge-space theory provides the methods of efficient analysis about learners' status of knowledge. This study designs and implements the support-learning tool based on the knowledge-space theory to increase the efficiency in classroom lessons through the development of various methods of analysis of learners' knowledge status.

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Nonparametric Method using Placement in an Analysis of a Covariance Model

  • Hwang, Dong-Min;Kim, Dong-Jae
    • Communications for Statistical Applications and Methods
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    • v.19 no.5
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    • pp.721-729
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    • 2012
  • Various methods control the influence of a covariate on a response variable. These methods are analysis of covariance(ANCOVA), RANK ANCOVA, ANOVA of (covariate-adjusted) residuals, and Kruskal-Wallis tests on residuals. Covariate-adjusted residuals are obtained from the overall regression line fit to the entire data set that ignore the treatment levels or factors. It is demonstrated that the methods on covariate-adjusted residuals are only appropriate when the regression lines are parallel and covariate means are equal for all treatments. In this paper, we proposed the new nonparametric method on the ANCOVA model, as applying joint placement in a one-way layout on residuals as described in Chung and Kim (2007). A Monte Carlo simulation study is adapted to compare the power of the proposed procedure with those of the previous procedure.

Comparison on Thermal Analysis Methods for Multi-Layer Insulation (다층박막단열재 열해석 방법 비교 연구)

  • Hyun, Bum-Seok;Kim, Hui-Kyung;Choi, Joon-Min
    • Proceedings of the KSME Conference
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    • 2003.11a
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    • pp.290-295
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    • 2003
  • Among the thermal analysis methods for Multi-Layer Insulation(MLI), effective emittance, diffusion MLI node and arithmetic MLI node methods are compared. The methods have been applied to the aluminum panel under the low earth orbit environment. TRASYS program is used for geometrical math modeling and SINDA program for thermal math modeling and temperature calculation. Test cases are selected according to MLI area on the panel. Temperature results are calculated and compared under the ratio of absorptivity and emissivity.

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POWER SYSTEM TRANSIENT STABILITY ANALYSIS USING TRANSITION MATRIX AND VOLTAGE DERIVATIVES (천이행렬과 전압 미분을 이용한 전력계통의 과도 안정도 해석)

  • Park, Young-Moon;Kim, Gwang-Won
    • Proceedings of the KIEE Conference
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    • 1990.07a
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    • pp.135-138
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    • 1990
  • For transient stability analysis of a power system, the new method using transition matrix is introduced in this paper. At the present the, Runge-Kutta, Modified-Euler and Trapezoidal methods have been very popular in most stability programs, Modified-Euler and Trapezoidal methods are inferior in accuracy and Runge-Kutta method has problems in computation time. The proposed algorithm requires transition matrix and its integrated values with derivatives of nonlinear parts in nonlinear differential equations for stability analysis. The method presented in this paper is between Modified-Euler and Runge-Kutta methods from the view point of computation time and is superior to the other methods in accuracy.

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Techniques of Selection of Landslide Hazard Area on Analysis of Topographical Data (지형 데이타 해석에 따른 산사태 위험지역 선정 기법)

  • 강인준;최철웅;장용구
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.12 no.2
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    • pp.147-154
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    • 1994
  • Landslides in the close residential area occur loss of life and properties. Usually soil mechanical methods and multi-statistical methods used to analysis the landslide. The factors of landslide analysis by multi-statistical methods are composite operations of geology, topography, vegetation, and climate etc. In this study, existing landslide areas are cheesed to extract the characteristics of their geographical data for adaption of Multi-statical methods. Authors give a weight to their values and analyze the some area using technique of overlap on GSIS.

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Evaluationn of the Accuracy for Regional Input Coefficients Estimated by Non-survey Methods (지역투입계수의 정확성 평가에 관한 연구)

  • 고석남;곽철홍
    • Journal of the Korean Regional Science Association
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    • v.12 no.2
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    • pp.1-19
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    • 1996
  • The purpose of this paper is to evaluate the accuracy of input coefficients which are usually estimated by various non-survey methods. The resulting analysis showed that there were considerable differences employed. One of the interesting findings was that the simple LQ method was shown to be better then the other non-survey methods with respect to the degree of accuracy. And from a sensitivity analysis which was to show the effect of changes in input coefficients on the level of production by industry, an increase of 10% in the value of input coefficient (machinary and equipment setor) resulted up to 500billion Won in GRP for the case region. Therfore one of the implications which we can derive from the resulting analysis is that it necessary to pay attention to the key coefficients first to save out time and money, while retaining a certain level of accuracy. One thing to be noted, however, is that the key coefficients but the total effects which are calculated through the Leontief inverse matrices. Therfore to enhance the accuracty of input coefficients estimated by nonsurvey methods it is required to handle the relevant setoral data more carefully or to employ semi-survey method in part.

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A Critical Review of Nurse Demand Forecasting Methods in Empirical Studies 1991~2014 (간호사 인력의 수요추계 방법론에 대한 비판적 검토: 1991~2014년간의 실증연구를 중심으로)

  • Jeong, Suyong;Kim, Jinhyun
    • Perspectives in Nursing Science
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    • v.13 no.2
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    • pp.81-87
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    • 2016
  • Purpose: The aim of this study is to review the nurse demand forecasting methods in empirical studies published during 1991~2014 and suggest ideas to improve the validity in nurse demand forecasting. Methods: Previous studies on nurse demand forecasting methodology were categorized into four groups: time series analysis, top-down approach of workforce requirement, bottom-up approach of workforce requirement, and labor market analysis. Major methodological properties of each group were summarized and compared. Results: Time series analysis and top-down approach were the most frequently used forecasting methodologies. Conclusion: To improve decision-making in nursing workforce planning, stakeholders should consider a variety of demand forecasting methods and appraise the validity of forecasting nurse demand.

Comparative research on calculation methods (point standpoint and area standpoint) of sunshine duration for building (건물 일조시간 계산방법(점,면)에 관한 비교연구)

  • Lee, Duck-Hyung;Choi, Chang-Ho;Lee, Hyun-Woo
    • Journal of the Korean Solar Energy Society
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    • v.24 no.3
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    • pp.9-17
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    • 2004
  • Nowadays, a concern of building environment has been arousing. Furthermore, according to this trend, the social concern has expended continuously. Especially, the right of daylight is essential for both the pleasant life and building maintenance. In this reason, it has dealt as like property right. Therefore, the Infringement on the right of daylight can be applicable to the infringement of property right. However, few un-notarized calculation methods have been used without careful examination about daylight duration calculation methods which can be used for determine sunshine infringement as the dispute solution, therefore. In this thesis We analyzed and concluded the differentiations of two calculation methods which are using nowadays.