• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2010년도 추계학술대회 초록집
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• pp.65.1-65.1
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• 2010

Thermal performance tests of solar thermal collectors include determination of coefficient parameters in an efficiency equation. The parameters can be estimated using regression method to minimize an objective function as sum of differences between measured efficiency data and regressed efficiency equation. However, this conventional approach doesn't consider measurement uncertainties. In this presentation, a method to determine regression parameters in the efficiency equation and uncertainties of the parameters is described with mainly mathematical expressions based on literature reviews. In the method, parameters in the equation for collector efficiency can be determined using regression analysis with a weighting factor in the objective function. The weighting factor can be uncertainties of the differences between measured and fitted efficiencies. To evaluate the approach, performance estimation of a solar collector using the efficiency equation with uncertainties is compared to the result using the conventional efficiency equation by a simulated way for a case in one of previous studies.

• 한국지진공학회:학술대회논문집
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• 한국지진공학회 2002년도 춘계 학술발표회 논문집
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• pp.327-334
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• 2002

This paper develops an optimized torsional design method of asymmetric wall structures considering deformation capacities of walls. Contrary to the current torsional provisions, a deformation based torsional design is based on the assumption that stiffness and strength are dependent. Current torsional provisions specify two design eccentricity of stiffness to calculate the design forces of members. But such a methodology leads to an excessive over-strength of some members and an optimal torsional behavior is not ensured. Deformation-based torsional design uses displacement and rotation angle as design parameters and calculates base shear for inelastic torsional response directly. Because optimal torsional behavior can be defined based on the deformation of members, deformation based torsional design procedure can be applied to the optimal and performance-based torsional design. To consider the effect of accidental eccentricity, an over-strength factor is defined. The over-strength factor is determined from performance level, torsional resistance and arrangement of walls.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2004년도 하계종합학술대회 논문집(1)
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• pp.23-26
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• 2004

This paper analyzed time delay and phase distortion that generates in multipath and the degree of distortion due to power attenuation factor when UWB system is applied at indoor environment and the effects of indoor structure and material on distortion factors. Based on these distortion factors, channel model similar to actual environment is mathematically described and multipath and the degree of signal distortion generated when UWB system is applied to random environment is tested through channel model simulation and varies distortion factor that UWB system needs to consider in different indoor environment is analyzed.

• 한국건강관리협회지
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• 제2권1호
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• pp.71-76
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• 2004

The Metabolic syndrome is a constellation of lipid and non-lipid factors of metabolic origin. The presence of any 3 of the following factors is considered sufficient for diagnosis : hypertension(BP <130/85mmHg), low HDL-cholesterol (<40mg% in men, <50mg% in woman), high triglyceride(>150mg%) and abdominal obesity(abdominal girth >102cm in men, 88cm in woman). The major adverse consequence of the metabolic syndrome is cardiovascular disease. Several studies have shown an association between metabolic syndrome and increased cardiovascular events. In Korea, the prevalence of the factor of metabolic syndrome has been increasing since 20 years previously when the Korean economy began to grow rapidly, with a resultant change in lifestyle, toward that of western countries. Thus, the management of the metabolic syndrome is an important social and medical issue in terms of the national health problem. This review will consider each factor in turn, providing insight for health care providers in an effort to prevention of cardiovascular events and maintenance of quality of life in persons with metabolic syndrome was discussed.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2004년도 추계학술대회
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• pp.1028-1033
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• 2004

The heat and flow characteristics in a single-phase parallel-flow heat exchanger was examined numerically to obtain its optimal shape. A response surface method was introduced to predict its performance approximately with respect to design parameters over design domain. Design parameters are inflow and outflow angle of the working fluid and horizontal and vertical location of inlet and outlet. The evaluation of the relative priority of the design parameters was performed to choose three important parameters in order to use a response surface method. A JF factor was used as an evaluation characteristic value to consider the heat transfer and the pressure drop simultaneously. The JF factor of the optimum model, compared to that of the base model, was increased by about 5.3%.

• Asia pacific journal of information systems
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• 제14권3호
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• pp.1-22
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• 2004

Technology acceptance model(TAM) has been widely used to predict the end-user's acceptance of a new IT/IS. We used TAM as a theoretical foundation to explain user's intention to use an Internet shopping mall. The theoretical model is tested with the questionnaires from 308 users of an Internet shopping mall. Results show that several individual characteristics such as Internet skills and self-efficacy have a significant impact on user's perception of usefulness and ease of use. Results also show that both perceived enjoyment and perceived usefulness of Internet shopping mall strongly predict intention to use the Internet shopping mall. However, perceived ease of use has no direct influence on intention to use the Internet shopping mall. Personal innovativeness and Internet skills also have a positive effect on perceived enjoyment. Therefore, Internet shopping mall managers have to consider intrinsic motivational factor(enjoyment) as well as extrinsic motivational factor(usefulness). In addition, individual characteristics should be emphasized to form the positive beliefs about using the Internet shopping mall.

• 대한지질공학회:학술대회논문집
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• 대한지질공학회 2003년도 정기총회 및 학술발표회
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• pp.153-158
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• 2003

Traditionally, the statistical methods has been used to analyze the relationship between landslide occurrence and related factors(soil depth, soil strength, slope angle, vegetation, etc.) in GIS technique. However, the method have no mechanical meaning. Therefore, the mechanical model is suggested in this research. The method analyzes the mechanical equilibrium of a potential slide block and then calculates a slope safety factor. Since this method is able to consider the balance of forces applied to the slope and is a more reasonable method for an individual site. In this research, the spatial data is obtained, managed and analyzed using GIS technique, and the infinite slope model is used to evaluate factor of safety and analyze the slope stability.

• 감성과학
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• 제4권1호
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• pp.33-42
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• 2001

The purpose of this study was to construct the scale in fashion sensibility. Base on the Fashion Magazines and free word association method, 919 affective words were condensed into 36 semantic differential bi-polar scales. 128 male and 128 female in Pusan rated their Fashion Sensibility by 87 kinds of costume samples from photographs divided into four types according to color, detail and trimming, pattern, textile. The obtained data analyzed by Cronbach ${\alpha}$, Factor analysis, Cluster analysis to consider of the reliability, tranquility, and resemblance among the meaning. The results of the analysis, it was found cleary that aesthetics, maturity character, and femininity masculinity etc were consisted of Fashion Sensibility and 25 item of affective words of Fashion Sensibility and 25 item of affective words of Fashion Sensibility were constructed.

• 한국정보통신설비학회:학술대회논문집
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• 한국정보통신설비학회 2007년도 학술대회
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• pp.436-439
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• 2007

This paper describes the optimization of PGS(Patterned Ground Shield) of 5.5 turns rectangular spiral inductor using Taguchi's method. PGS is decrease method of parasite component by silicon substrate among dielectric loss reduction method. By using the taguchi's method, each parameter is fixed upon that PGS high poison(A), slot spacing(B), strip width(C) and overlap turn number(D) of PGS design parameter. Then we verified that percentage contribution and design sensitivity analysis of each parameter and level by signal to noise ratio of larger-the-better type. We consider percentage contribution and design sensitivity of each parameter and level, and then verify that model of optimization for PGS is lower inductance decreasing ratio and higher Q-factor increasing ratio by EM simulation.

• Composites Research
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• 제15권4호
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• pp.37-42
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• 2002

면외전단하중(anti-plane shear loading)을 받는 기능경사 압전 세라믹 무한 스트립(functionally graded piezoelectric ceramic strip)의 상하 양쪽 끝단의 중앙에 평행하게 존재하는 유한한 크기의 균열(Griffith crack)에 대한 특이응력(singular stress)과 전기장(electric field)을 선형 압전 이론(theory of linear piezoelectricity)을 이용하여 결정한다. 푸리에 변환(Fourier transform)을 이용하여 복합적분 방정식을 구성하며, 이를 제2종 Fredholm 적분 방정식(Fredholm integral equation of the second kind) 으로 표현한다. 또한 응력세기계수(stress intensity factor)와 에너지 해방률(energy release rate)에 대한 수치 결과를 제시하였다.