• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제49권4호
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• pp.249-257
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• 2000

In this paper, we propose the use of stochastic finite element method, that is popularly employed in mechanical structure analysis, for more practical designing purpose of RF device. The proposed method is formulated based on the vector finite element method cooperated by pertubation analysis. The method utilizes sensitivity analysis algorithm with covariance matrix of the random variables that represent for uncertain physical quantities such as length or various electrical constants to compute the probabilities of the measure of performance of the structure. For this computation one need to know the variance and covariance of the random variables that might be determined by practical experiences. The presenting algorithm has been verified by analyzing several device with different be determined by practical experiences. The presenting algorithm has been verified by analysis several device with different measure of performanes. For the convenience of formulation, two dimensional analysis has been performed to apply it into waveguide with dielectric slab. In the problem the dielectric constant of the dielectric slab is considered as random variable. Another example is matched waveguide and cavity problem. In the problem, the dimension of them are assumed to be as random variables and the expectations and variances of quality factor have been computed.

• Journal of the Korean Wood Science and Technology
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• 제44권2호
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• pp.204-217
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• 2016

Modified poplar has emerged as a potential raw material for furniture production. Lack of specific modified poplar strength information; however, restricts applications in the furniture industry especially as related to strength in corner-joints. Optimization of strength in L-shaped corner dowel modified poplar joints under compression loads utilizing finite element analysis (FEA) by Taguchi method with the focus of this study. Four experiment factors (i.e., Structure Style, Tenon Length, Tenon Diameter, and Tenon Gap), each at three levels, were conducted by adopting a $L_9-3^4$ Taguchi orthodoxy array (OA) to determine the optimal combination of factors and levels for the von Mises stress utilizing ANSYS software. Results of Signal-to-Noise ratio (S/N) analysis and the analysis of variance (ANOVA) revealed the optimal L-shaped corner dowel joint in modified poplar is $45^{\circ}$ Bevel Butt in structure style, 24 mm in tenon length, 6 mm in tenon diameter, and 20 mm in tenon gap. Tenon length and tenon gap are determined to be significant design factors for affecting von Mises Stress. Confirmation tests with optimal levels and experimental test indicated the predicted optimal condition is comparable to the actual experimental optimal condition.

• 대한간호학회지
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• 제45권5호
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• pp.650-660
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• 2015

Purpose: The purpose of this study was to develop an instrument to measure the parenting behavior of primary caregivers of children in early childhood. Methods: An instrument was developed according to Devellis's instrument development process. The participants in this study who completed the main survey were 370 mothers and grandmothers. The survey was conducted from June 1 to July 30, 2014, and collected data were analyzed using item analysis, half-split reliability and Cronbach's ${\alpha}$ coefficient, exploratory and confirmatory factor analysis, convergent validity. Results: The factor structure of the instrument showed the cumulative variance as 55.7% in the factor analysis. As a result of a confirmatory factor analysis, a four-factor structure was found to be appropriate, and the construct validity and convergent validity of the instrument were thereby confirmed. The finalized parenting behavior instrument consisted of 26 items and four independent factors: affectionate, laissez-faire, educational and impulsive. A five-point Likert scale was employed, and a higher score in a particular factor showed that most of the behaviors belonged to the factor. Conclusion: The instrument developed in this study was found to be reliable and valid, and can be used to develop parent-child relationship building.

• Bulletin of the Korean Chemical Society
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• 제32권12호
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• pp.4341-4346
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• 2011

Impact sensitivity, one of the most important screening factors for novel high energy density materials (HEDMs), was predicted by use of quantitative structure-property relationship (QSPR) based on the electrostatic potential (ESP) values calculated on the van der Waals molecular surface (MSEP). Among various 3D descriptors derived from MSEP, we utilized total and positive variance of MSEP, and devised a new QSPR equation by combining three other parameters. We employed 37 HEDMs bearing a benzene scaffold and nitro substituents, which were also utilized by Rice and Hare. All the molecular structures were optimized at the B3LYP/6-31G(d) level of theory and confirmed as minima by the frequency calculations. Our new QSPR equation provided a good result to predict the impact sensitivities of the molecules in the training set including zwitterionic molecules.

• 한국농촌생활과학회지
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• 제7권1호
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• pp.69-80
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• 1996

The purpose of this study is to offer basic data of education to improve farm lives though investigating rural homemakers' life style. The results of this study are as follows : 1. The life structure of rural homemakers was classified into two structures as a material resources and human resources. The life style of rural homemakers was classified into systematical life style, traditional value style, social active style, and progressive active style. 2. The life styles of rural homemakers according to social population variance were as follows. The lower of age, homemakers whose family incomes more 30 million won or below 10 million won, who has religions, who employed in livestock were showed at very systematical life style. The homemakers who live in mountain village, higher the much age becomes, and the education level become lower, have showed traditional value style. Rural homemakers the lower of age, the higher incomes, composed of single parent ＋ children who remain single were appeared social active style. Rural homemakers the lower of age, the more shortened farm life periods, who employed in livestock were appeared progressive active style. 3. Systematical life style was more affected by material resources structure, traditional value style was affected by material resources. And social active style was more affected by human resources, progressive active style was affected by human resources.

• Asian-Australasian Journal of Animal Sciences
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• 제19권6호
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• pp.763-768
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• 2006

Genetic and pharmacological studies in mice have demonstrated a complementary role for the melanocortin 4 receptor (MC4R) in the control of food intake, energy balance and body weight. This study was designed to investigate the associations of a MC4R gene polymorphism on chicken growth and body composition traits in broiler lines divergently selected for abdominal fat. A SNP (G54C) was found in CDS region of chicken MC4R gene. The analysis of the least squares and variance revealed a significant association between the G54C SNP and BW, CW and SL at 7 wk of age, and there were significant differences in different genotypes (p<0.05). The results from protein secondary structure prediction and tertiary structure prediction showed that it appeared a helix in $13^{th}$ amino acid and two strands at $14^{th}$ and $15^{th}$ amino acid in mutant protein, respectively. It maybe induce the change of the activity or function of MC4R gene in poultry.

• 한국정보통신학회논문지
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• 제5권5호
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• pp.848-852
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• 2001

생체신호인 심전도(ECG), 근전도(EMG), 뇌파(EEG)는 환자진단에 있어 매우 중요한 신호이다. 이 신호는 많은 잡음이 혼합되어 있고, 시변과 비선형적인 특정을 가지고 있어 잡음제거가 어렵다. 따라서 환자 또는 시스템의 환경에 따라 적응하여 필터링을 하여야 한다 그러나 현재 적응필터는 고정된 필터 차수를 설정하여 잡음을 제거하기 때문에 과도한 필터 차수는 시스템의 출력인 생체신호의 왜곡을 발생시킨다. 따라서 본 논문에서는 생체신호처리를 위한 적응필터의 구조와 성능을 개선시키기 위한 알고리즘을 제안하고 실험한 결과 최적의 필터 차수를 구하였다.

• 노동경제논집
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• 제34권2호
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• pp.29-52
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• 2011

본고는 1990년대 후반 이후 한국기업에 급속히 도입되어 온 연봉제가 실제로 성과에 따른 임금격차를 가져왔는지에 대하여 분석하였다. 노동부 "임금구조기본통계조사" 1996년부터 2006년까지 100인 이상 기업 대졸 사무직에 대한 자료를 활용하였고, 기업내 임금격차 변수로는 개인 속성에 대한 영향을 배제할 수 있도록 임금함수를 추정하고 잔차의 분산을 기업수준의 변수로 활용하여 분석하였다. 분석 결과, 연봉제의 도입은 기업내 임금격차를 확대시키는 것으로 나타났다. 그러나 연봉제 적용 비중과 임금격차 간의 관계는 비선형관계($\bigcap$)임을 시사하는 결과가 나타났다.

• 응용통계연구
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• 제15권1호
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• pp.45-55
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• 2002

미국 통계국(Bureau of Census)에서 실시하고 있는 소매동태조사(Monthly Retail Trade Survey)를 중심으로 3개의 교체그룹을 갖는 2수준 교체표본설계를 설명하고, 특성치의 추정을 위한 복합추정량을 다루었다. 설계 간격 (design gap)이 존재하는 2수준 교체표본설계에서의 일반화복합추정량(generalized composite estimator)과 순환복합 추정량(recursive composite estimator)을 제시하였고, 각 추정량의 분산식을 유도하였다. 또한 공분산구조와 관련된 응답변동(response variability)과 반복응답으로 부터 연유되는 상관관계를 고려하여 복합추정량 사이의 효율을 비교하였다.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2001년도 봄 학술발표회 논문집
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• pp.102-109
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• 2001

In order to take account of the statistical properties of probability variables used in the structural analysis, the conventional approach using the safety factor based on past experience usually estimated the safety of a structure. The real structures could only be analyzed with the error in estimation of loads, material characters and the dimensions of the members. But the errors should be considered systematically in the structural analysis. Structural safety could not precisely be appraised by the traditional structural design concept. Recently, new approach based on the probability concept has been applied to the assessment of structural safety using the reliability concept. Thus, the computer program by the Probabilistic FEM is developed by incorporating the probabilistic concept into the conventional FEM method. This paper estimated for the reliability of a plane stress structure by Advanced First-Order Second Moment method using von Mises, Tresca and Mohr-Coulomb failure criterions. The reliability index and failure probability of attained by the Monte Carlo Simulation method with the von Mises criterion were same as PFEM, but the Monte Carlo Simulation were very time-consuming. The variance of member thickness and load could influence the reliability and failure probability most sensitively among the design variables from the results of the parameter analysis. And proper failure criterion must be used to design safely.