• 한국공간구조학회논문집
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• 제1권2호
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• pp.111-116
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• 2001

This paper is a study on the elasto-plastic analysis of reinforced concrete precast large panel connections by rigid element spring model. In the analysis of rigid element spring model, each collapsed part or piece of structures at limiting state of loading is assumed to behave like rigid bodies. The present author propose new elements for the improement and expansion of the rigid element spring model. In this study, it is proposed how the rigid element method can be applied to the elesto-plastic analysis of precat large panel connections. Some numerical results of analytical modeling and load displacement curves are shown.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2004년도 춘계학술대회
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• pp.513-518
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• 2004

KARI(Korea Aerospace Research Institute) has developed smart unmaned aerial vehicle(UAV) since 2002. Smart UAV has tilt rotor configuration which can take off and land vertically. For designing and developing smart UAV, it is necessary to obtain design loads. ARGON which use the panel method is multidisciplinary aircraft design program developed and modified by KARI and TsAGI. Panel method is very useful to obtain aerodynamic loads, so it have been used widely for aircraft loads analysis. For flight loads analysis, we have to prepare regulations and load conditions, and then design aerodynamic panel model, mass model and structure model. In this paper, we introduce the flight loads analysis procedure briefly, and show the smart UAV loads analysis procedure and result using ARGON.

• 한국컴퓨터정보학회논문지
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• 제22권10호
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• pp.145-150
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• 2017

This study aims to analyze panel data using OECD Health data of 34 years to examine how significant the inequality of income is to the inequality of health. The data was from OECD's pooled Health data of 32 countries from 1980 to 2013. The process of determining analysis model was as follows; First, through the descriptive statistics, we examined averages and standard deviation of variables. Second, Lagrange multiplier test has done. Third, through the F-test, we compared Least squares method and Fixed effect model. Lastly, by Hausman test, we determined proper model and examined effective factor using the model. As a result, rather than Pooled OLS Model, Fixed Effect Model was shown as effective in order to consider the characteristics of individual in the panel. The results are as follows: First, as relative poverty rate(${\beta}=-19.264$, p<.01) grows, people's life expectancy decreases. Second, as the rate of smoking(${\beta}=-.125$, p<.05) and the rate of unemployment (${\beta}=-.081$, p<.01) grows, people's life expectancy decreases. Third, as health expenditure(${\beta}=.414$, p<.01) shares more amount of GDP and as the number of hospital beds(${\beta}=-.190$, p<.05) grows, people's life expectancy increases.

• 의정연구
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• 제23권2호
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• pp.147-177
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• 2017

한국 선거에서 정치 이념의 역할에 대해 그동안 수많은 연구가 이루어졌으나, 지금까지의 연구들은 예외 없이 횡단면 데이터(cross-sectional data) 분석에 전적으로 의존하였다. 기존의 연구들과 달리 이 연구는 지난 제18대 대통령 선거에서 나타난 이념 투표의 영향을 패널 데이터 분석(panel data analysis)을 통해 보다 엄밀하게 검증한다. 구체적으로, "EAI 총선대선패널조사, 2012"를 이용하여 지난 18대 대통령 선거 시기(2012년 4월 중순-12월 하순)에 정치적이념이 유권자들의 후보 호오도(candidate evaluation)와 후보 선택(vote choice)에 미친 영향을 고정 효과(fixed effects) 분석과 변동 효과(random effect) 분석 등 표준적인 패널 데이터 분석을 통해 살펴보았다. 또한 이념투표의 대표적 설명 모형인 근접성 모형(proximity model)과 방향성 모형(directional change model)을 적용한 결과를 비교 분석하였다. 분석 결과, 지난 18대 대통령 선거에서 진보와 보수의 정치적 이념은 박근혜와 문재인후보에 대한 호오도 및 이들에 대한 지지에 독립적이고 유의미한 영향을 미쳤다고 할 수 있다. 즉, 유권자들은 특정 후보와의 이념적 차이가 크다고 느낄수록 그후보에 대한 지지 확률 및 호오도가 상대적으로 낮아졌다. 그리고 이러한 이념투표의 영향은 근접성 모형보다 방향성 모형에서 상대적으로 뚜렷하게 나타났다.

• International Journal of Aeronautical and Space Sciences
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• 제17권4호
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• pp.476-490
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• 2016

This paper defines mode shape function of a composite solar panel assumed as Kirchhoff-Love plate for considering a torsional mode of composite solar panel. It then goes on to define dynamic model of a high-agility satellite considering the flexibility of composite solar panel as well as stiffness of a solar panel's hinge using Lagrange's theorem, Ritz method and the mode shape function. Furthermore, this paper verifies the validity of dynamic model by comparing numerical results from the finite element analysis. In addition, this paper performs a dynamic response analysis of a rigid satellite which includes only natural modes for solar panel's hinges and a flexible satellite which includes not only natural modes of solar panel's hinges, but also structural modes of composite solar panels. According to the results, we confirm that the torsional mode of solar panel should be considered for the structural design of high-agility satellite. Finally, we performed optimization of high-agility satellite for minimizing mass with solar panel's area limit using the defined dynamic model. Consequently, we observed that the defined dynamic model for a high-agility satellite and result of the optimal design are very useful not only because of their optimal structural design but also because of the dynamic analysis of the satellite.

• 보건행정학회지
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• 제29권3호
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• pp.332-341
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• 2019

Background: This study analyzes the effects of the individual's health behavior on the health and the medical demand for the management of health and medical expenses. Methods: This study uses the Korea Health Panel Survey data from 2010 to 2015. We utilize the panel ordered logit model and the panel Tobit model with the subjective health status and the medical expenses as the dependent variables. Results: Chronic diseases would cause the deterioration of his or her health and the increase in medical expenses. Smoking and drinking alcohol would deteriorate one's health. The total amount of cigarettes increases medical expenses. Exercises could make people healthier, whereas excessive exercise might increase medical expenses. Private health insurance would increase medical expenses. Conclusion: Since health could reduce the medical expenses, people should promote one's health by changing one's behavior for health.

• 소음진동
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• 제9권4호
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• pp.785-794
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• 1999

The panel contribution analysis to reduce interior booming noise of a passenger car is carried out using both experimental method and numerical one. The accelerations of panels are measured on the outer surface of car body during operation. The acoustic characteristic of cavity is represented by two different ways. One is the acoustic transfer function obtained by experiment with reciprocal manner. The other is the boundary element model and numerical results of the model are calculated using SYSNOISE. The results from numerical method show more good agreement with measured sound pressure levels than the experimental one. Contributions of panels for interior noise are ranked and structure of the car is reinforced according to the results, which shows that the panel contribution analysis is a powerful tool to lessen structure-borne noise of passenger vehicle.

• Communications for Statistical Applications and Methods
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• 제26권4호
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• pp.371-383
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• 2019

Panel data sets have been developed in various areas, and many recent studies have analyzed panel, or longitudinal data sets. Maximum likelihood (ML) may be the most common statistical method for analyzing panel data models; however, the inference based on the ML estimate will have an inflated Type I error because the ML method tends to give a downwardly biased estimate of variance components when the sample size is small. The under estimation could be severe when data is incomplete. This paper proposes the restricted maximum likelihood (REML) method for a random effects panel data model with a censored dependent variable. Note that the likelihood function of the model is complex in that it includes a multidimensional integral. Many authors proposed to use integral approximation methods for the computation of likelihood function; however, it is well known that integral approximation methods are inadequate for high dimensional integrals in practice. This paper introduces to use the moments of truncated multivariate normal random vector for the calculation of multidimensional integral. In addition, a proper asymptotic standard error of REML estimate is given.

• 한국공간구조학회논문집
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• 제12권1호
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• pp.51-58
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• 2012

압출성형 ECC 패널을 활용한 철근콘크리트 복합 슬래브 구조에 대한 비선형 휨 해석 모델을 새롭게 제시하였다. ECC 패널은 직접인장시험 결과로부터 균열 이후에 고인성 인장거동을 하는 재료로 모델링하였다. 개발 모델을 기존 철근콘크리트 슬래브 및 ECC 패널 철근콘크리트 복합슬래브 실험체의 휨 실험결과와 비교하였다. 예측결과는 실험결과와 잘 일치하였으며, ECC 패널 적용 철근콘크리트 복합슬래브는 균열제어, 휨내력 및 휨변형능력 개선에 장점이 있는 것으로 판단되었다.

• Steel and Composite Structures
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• 제16권4호
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• pp.417-436
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• 2014

During an earthquake, steel frame columns can be subjected to high axial forces combined with inelastic rotation demand resulting from story drift. Generally, the whole beam or component can be represented with one element. In elasto-plastic analysis, subdivision is necessary if the plastic deformation occurs within two ends of beams. If effects of the joint panel are necessarily considered in the analysis, the joint panel should be represented with an independent element. It is a special element to represent the shear deformation of the joint panel in the beam-column connection zone. Several analytical models for panel zone (PZ) behavior exist, in terms of shear force-shear distortion relationships. Among these models, the Krawinkler PZ model is the most popular one which is used in the AISC code. Some studies have pointed out that Krawinkler's model gives good results for the range of thin to medium column flanges thickness. This paper, introduces a new model to estimate the response of shear force-shear distortion for the PZ including column axial force. The model is applicable to both thin and thick column flange. To achieve an appropriate PZ mathematical model first, the effects of PZ strength and stiffness on connection response are parametrically studied using finite element models. More than one thousand and four-hundred beam-column connections are included in the parametric study, with varied parameters; then based on analytical results a simple mathematical model is presented. A comparison between the results of proposed method herein with FE analyses shows the average error especially in thick column flange is significantly reduced which demonstrates the accuracy, efficiency, and simplicity of the proposed model.