• Journal of the Korean Data and Information Science Society
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• 제17권2호
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• pp.543-557
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• 2006

This paper is concerned with the applicability of the chi-square approximation to the six disparity statistics: the Pearson chi-square, the generalized likelihood ratio, the power divergence, the blended weight chi-square, the blended weight Hellinger distance, and the negative exponential disparity statistic. Three dimensional contingency tables of small and moderate sample sizes are generated to be fitted to all possible hierarchical log-linear models: the completely independent model, the conditionally independent model, the partial association models, and the model with one variable independent of the other two. For models with direct solutions of expected cell counts, point estimates and confidence intervals of the 90 and 95 percentage points of six statistics are explored. For model without direct solutions, the empirical significant levels and the empirical powers of six statistics to test the significance of the three factor interaction are computed and compared.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
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• 제26권3호
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• pp.226-235
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• 2015

Objectives : The purpose of this study was to examine the factor structure of the Adolescent Personality Assessment Inventory (PAI-A) in a standardized adolescent sample using exploratory factor analysis (EFA) and confirmatory factor analysis (CFA). Methods : For this purpose, three models about factor structure of the PAI-A were explored with EFA in 490 adolescents and then were evaluated with CFA in 268 young offenders. Results : The results showed that the five factor model was considered to be most appropriate for factor structures of the PAI-A in EFA. However, none of the factor models were appropriate for the factor structures of the PAI-A in CFA. Conclusion : These findings suggest that the "five factor model" is thought to explain the PAI-A the best, but further studies are needed.

• Journal of international Conference on Electrical Machines and Systems
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• 제1권4호
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• pp.472-476
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• 2012

In this paper, a sensorless control scheme for a three-phase bi-directional voltage-type PWM rectifier in wind power generation system that operates without the input AC voltage sensors (generator side) is described. The basic principles and classification of the PWM rectifier are analyzed, and then the three-phase mathematical model of the input AC voltage sensorless PWM rectifier control system is established. The proposed scheme has been developed in order to lower the cost of the three-phase PWM rectifier but still achieve excellent output voltage regulation, limited current harmonic content, and unity input power factor.

• 소음진동
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• 제9권1호
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• pp.206-213
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• 1999

선박의 보-유추 진동해석에 있어 2차원 부가수질량의 3차원 효과를 고려하기 위해서 3차원 수정계수(J-factor)를 계산해야 하는데 광폭선의 경우에는 J-factor의 계산이 부정확하고 번거롭다. 이 논문에서는 이를 개선하기 위해 새로운 선박의 보-유추 접수진동해석 방법을 소개하였다. 이 방법은 선박에 접수된 유체에 대해 BEM 기법을 이용하여 3차원 유체력을 직접 계산하고 이를 일정 간격으로 나눈 각 스트립에 집중질량으로 평가한 후에 선체의 보모델과 결합하여 보-유추 진동해석을 수행하는 방법이다. 오픈탑 컨테이너선의 모델에 대해 기존의 보-유추 진동해석방법과 이 논문에서 제시한 새로운 진동해석방법을 이용하여 진동해석을 수행하고 가진 실험에 의한 진동계측결과와 상호 비교함으로써 새로운 방법의 유용성을 검증하였다.

• 환경영향평가
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• 제2권1호
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• pp.39-55
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• 1993

The importance of urban and regional natural park increases because of the needs for preserving the natural resources and providing with natural recreation space in nature. This planning of natural park management should be established based on the research of the various natural resources in the park. But for the lack of effective data synthesizing methods and concepts, only some restricted factors for zoning plan are considered even though GIS computer system for large complex simulation is used. Therefore, in this study three ecological zoning models such as Basic Factor Model (BFM), Visual Landscape Model (VLM) and Comprehensive Ecological Model (CEM) are proposed and applied to Byounsan Peninsula Nature Park(BPNP) for comparison with the current natural park zoning. The BFM has three components -elevation, slope and vegetation. The VLM has applied with six components -elevation, slope, vegetation, road type, and the visual distance. Finally the CEM's modelling factors have included all of BFM, VLM components are added with the land use type, nature and historic resource factors. The zoning concept of BPNP was based on "Minimization" focused on the specific factors. But introduced modelling concept is "Optimization" based on the total ecological environment. So the result of the modelling has larger area for preservation and development zoning compared with the current zoning whose characteristics are ambiguous which allows the environmental destruction. The future study issues will be the determination of the weighting factor, component reconsideration based on the ground truth data and the agriculture residential area zoning.

• 대한토목학회논문집
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• 제32권1A호
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• pp.39-48
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• 2012

본 논문에서는 V형 노치 및 반원형 노치 균열을 갖는 패치보강 적층판의 응력확대계수 산정을 위하여 수치해석적 방법을 사용한다. p-수렴 비등매개변수 모델이 고려되고, 이와 같은 비등매개변수 모델의 결과를 활용한 3차원 가상균열닫힘법에 대한 식이 표현된다. 1차원 로바토 함수로부터 확장된 3차원 계층적 형상함수를 가지고서, 임의의 요소에서의 변위장의 변위-변형률 관계와 3차원 구성방정식이 표현된다. 원형경계의 기하형상을 나태내기 위해 초유한사상기법을 사용한다. 응력집중계수, 응력분포, 자유도, 그리고 무차원 응력확대계수 등의 항목에 대해서, 제안된 모델의 정확도와 단순성이 기존의 결과들과의 비교를 통해 설명된다. 균열 적층판의 폭, 높이, 노치근입부의 반경, V형 노치의 경사각, 균열길이 등의 변화에 따른 응력확대계수가 산정된다.

• 산업기술연구
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• 제18권
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• pp.323-328
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• 1998

A current controlled VSI-PWM rectifier and inverter with capacitor dc link is regarded as one of the most promising structures for three-phase to three-phase to three-phase power conversion. This type of converter normally requires twelve switches for a rectifier and inverter composed of self turn-off switch such as a bi-polar transistor or IGBT with an anti-parallel diode. In this paper, a new three-phase to three-phase converter for ac motor drives is proposed. The proposed converter employs only eight switches and has the capability of delivering sinusoidal input currents with unity power factor and bidirectional power flow. This paper describes the feasibility and the operational limitations of the proposed structure. A mathematical model of the system is derived using generalized modulation theory and experimental results for steady state and dynamic behavior are presented to verify the developed model.

• Steel and Composite Structures
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• 제7권2호
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• pp.119-133
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• 2007

Based on stability theory of current rigid steel frames and using the three-column subassemblage model, the governing equations for determining the effective length factor (${\mu}$-factor) of the columns in semirigid composite frames are derived. The effects of the nonlinear moment-rotation characteristics of beam-to-column connections and composite action of slab are considered. Furthermore, using a two-bay three-storey composite frame with semi-rigid connections as an example, the effects of the non-linear moment-rotation characteristics of connections and load value on the ${\mu}$-factor are numerically studied and the ${\mu}$-factors obtained by the proposed method and Baraket-Chen's method are compared with those obtained by the exact finite element method. It was found that the proposed method has good accuracy and can be used in stability analysis of semi-rigid composite frames.

• 대한기계학회논문집A
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• 제24권9호
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• pp.2252-2258
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• 2000

In order to investigate the effect of nozzle on stress concentration in pressure vessels, three dimensional finite element analyses were performed. The results were compared with those for corresponding two dimensional axisymmetric finite element analyses. A three dimensional finite element model with a surface crack was also designed to evaluate the effect of internal pressure and heat transfer on crack face, and the resulting stress intensity factors from the finite element analyses were compared with those for ASME Sec. XI and Raju-Newman's stress intensity factor solution. As a result, the validity of currently available stress intensity factor solutions for a surface crack was reviewed in the presence of geometrical complexity, heat transfer and internal pressure.

• 한국심리학회지 : 문화 및 사회문제
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• 제24권3호
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• pp.385-410
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• 2018

물질주의 가치 추구는 한국인의 정신건강 및 심리적 안녕감을 이해하는 데 중요한 변인일 수 있다. 이 연구는 물질주의 연구를 활성화하고 신뢰로운 측정을 하고자 물질주의 가치 척도로 가장 자주 사용되는 Richins와 Dawson(1992)의 물질주의 가치 척도(Material Values Scale)를 한국어로 번안하여 타당화하기 위해 실시하였다. 연구 1은 번안한 한국판 물질주의척도의 요인구조를 확인하고 신뢰도 및 타당도를 검증하였다. 이를 위해 대학생 417명(표본 1)을 대상으로 확인적 요인분석을 실시하였고, 그 결과 원척도의 요인과 동일한 3요인을 확인하였다. 원척도가 제시한 하위요인을 한국어로 번역하여 성공판단, 소유중심, 행복추구라 명명하였다. 이 과정에서 요인부하량이 낮은 3개의 문항은 물질주의 가치 척도의 다른 언어로의 타당화 연구를 참조하여 삭제하였고, 총 15문항으로 한국판 물질주의척도를 구성하였다. 연구 2에서는 표본 1과 유사한 성격을 지닌 대학생 650명(표본 2)을 대상으로 한국판 물질주의척도를 검증한 결과 수렴 및 변별타당도, 동시타당도, 예측타당도가 양호한 것으로 밝혀졌다. 또한 경제활동을 하는 직장인 392명(표본 3)과 대학생(표본 2)을 대상으로 다집단 요인분석을 실시한 결과 한국판 물질주의척도를 대학생과 직장인에게 동일하게 사용할 수 있는 것으로 나타났다. 직장인(표본 3)을 대상으로 검증한 결과 예측타당도가 양호한 것으로 나타났다. 여자 대학생 408명(표본 4)을 대상으로 6개월 간격으로 설문을 실시한 결과 검사-재검사 신뢰도 또한 양호한 수준으로 확인되었다. 이러한 결과는 한국판 물질주의척도가 성인을 대상으로 한 개인의 물질주의 가치 수준을 신뢰롭고 타당하게 평가하는 도구임을 의미한다.