• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.2
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• pp.268-276
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• 2017

The aim of this study was to verify the theoretical relationship between sports ability beliefs, achievement goal orientation, exercise flow, and athletic performance in college golf athletes. The results of the Statistical Package for Social Sciences (SPSS) 18.0 and Analysis of MOment Structures (AMOS) 18.0 performed on the data collected from 211 participants are as follows. First, hypothesis testing showed that college golf athletes with incremental beliefs set task-oriented goals (C.R.=3.780, p<.001). Second, the task-oriented goals (C.R.=4,082, p<.001) and ego-oriented goals (C.R.=3.819, p<.001) in achievement goal orientation raised the level of flow during golf. Third, in achieving goal orientation, only task orientation led to a higher perceived level of golf performance (C.R.=3.020, p<.01). Fourth, a higher level of flow led to higher levels of golf performance (C.R.=4.642, p<.001). Other sub-factors were not statistically significant in the current study. These results could be applied in the field of sports as they show what results can be achieved depending on the athlete's belief in their sports ability.

• Journal of the Korean Society for information Management
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• v.18 no.3
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• pp.265-284
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• 2001

The aim of this study was to discover the correlation between users cognitive style and their attitude towards evaluating the system. Postgraduate students cognitive styles were defined as Verbaliser/Imager and Wholist/Analytic, and the functionality and ease of learning features of a Web-based OPAC(Online Public Access Catalogue) system were evaluated using a combined evaluation methods: interviews for the preliminary survey, a questionnaire far the central data collection, and a psychometric approach for the judgement of students cognitive style using Ridings CSA(Cognitive Style Assessment) tool. Forty-four postgraduate student volunteers responded and data was analysed using SPSS(Statistical Package for Social Science) for Windows. The statistical analysis of each feature of the evaluation, the correlation between the variables, and the features were explored using Pearsons correlation coefficients(r). In exploring the effects of the cognitive styles of individuals, this study has failed to reveal a significant (P < 0.05) correlations in the interactive Web-based OPACs evaluation. It could be said that the contribution of cognitive styles to evaluating Web-based OPACs is likely to be weaker than that of non-cognitive (or demographic) variables.

• Korean Journal of Food Science and Technology
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• v.23 no.2
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• pp.217-223
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• 1991

A capillary method was used to evaluate the properties of mass transfer process and diffusion coefficients in the gel food. Amaranth dye was selected as a diffusant material to visualize the degree of diffusion procedure easily. After contacting cylinder containing agar gel with amaramth dye solution for some hours, the gel was cut to five segments by 0.5 cm in length. The diffusant concentration from the segments were measured by the spectrophotometer at 523 nm. Prediction models for the diffused quantities in gel food were established by the regression program of SPSS package program. Generally, diffusion coefficient can be calculated by Fick's second law, however, it will be determined by using numerical analysis method more easily. Finally the diffusion coefficients in this research were calculated by arithmetic mean of the measured values. As raising gel agent concentration, the mean diffusion coefficient tended to decrease because the obstruction effect came to become significant.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.06a
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• pp.158-158
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• 2008

모바일 정보통신기기를 중심으로 실장모듈의 초소형화, 고집적화로 인해 접속단자의 피치가 점점 미세화 됨에 따라 플립칩 본딩용 접착제에 함유되는 무기충전제인 실리카 필러의 크기도 미세화되고 있다. 본 연구에서는 NCP (non-conductive paste)의 실리카 필러의 크기가 COB(chip-on-board) 플립칩 패키지의 신뢰성에 미치는 영향을 조사하였다. 실험에 사용된 실리카 필러는 Fused silica 3 종과 Fumed silica 3종이며 response surface 실험계획법에 따라 혼합하여 최적의 혼합비를 정하였다. 테스트베드로 사용된 실리콘 다이는 투께 $700{\mu}m$, 면적 5.2$\times$7.2mm로 $50\times50{\mu}m$ 크기의 Au 도금범프를 $100{\mu}m$ 피치, peripheral 방식으로 형성시켰으며, 기판은 패드를 Sn으로 finish 하였다. 기판을 플라즈마 전처리 후 Panasonic FCB-3 플립칩 본더를 이용하여 플립칩 본딩을 수행하였다. 패키지의 신뢰성 평가를 위해 $-40^{\circ}C{\sim}80^{\circ}C$의 열충격시험과 $85^{\circ}C$/85%R.H.의 고온고습시험을 수행하였으며 Die shear를 통한 접합 강도와 4-point probe를 통한 접속저항을 측정하였다.

• Journal of Mechanical Science and Technology
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• v.20 no.2
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• pp.251-261
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• 2006

The objective of this work is to apply artificial neural networks for solving inverse problems in the structural optimization of a fiber optic pressure sensor. For the sensor under investigation to achieve a desired accuracy, the change in the distance between the tips of the two fibers due to the applied pressure should not interfere with the phase change due to the change in the density of the air between the two fibers. Therefore, accurate dynamic analysis and structural optimization of the sensor is essential to ensure the accuracy of the measurements provided by the sensor. To this end, a normal mode analysis and a transient response analysis of the sensor were performed by combining commercial finite element analysis package, MSC/NASTRAN, and MATLAB. Furthermore, a parametric study on the design of the sensor was performed to minimize the size of the sensor while fulfilling a number of constraints. In performing the parametric study, the need for a relationship between the design parameters and the response of the sensor was fulfilled by using a neural network. The whole process of the dynamic analysis using commercial finite element analysis package and the parameter optimization of the sensor were automated within the MATLAB environment.

• Coupled systems mechanics
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• v.1 no.2
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• pp.165-182
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• 2012

Macroscopic hot spots formed due to the large thermal gradients at the surface of the disc brake rotor, make the rotor to fail or wear out early. Thermo-elastic deformation results in contact concentration, leading to the non uniform distribution of temperature making the disc susceptible to hot spot formation. The formation of one hot spot event will predispose the system to future hot spotting at the same location. This leads to the complete thermo-elastic instability in the disc brakes; multitude parameters are responsible for the thermo elastic instability. The predominant factor is the sliding velocity and above a certain sliding velocity the instability of the brake system occurs and hot spots is formed in the surface of the disc brake. Commercial finite element package ABAQUS(R) is used to find the temperature distribution and the result is validated using Rowson's analytical model. A coupled analysis methodology is evolved for the automotive disc brake from the transient thermo-elastic contact analysis. Temperature variation is studied under different sliding speeds within the operation range.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2001.11a
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• pp.45-53
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• 2001

Copper bus-bar is made by drawing process and used in many part of industry. When design drawing die for copper bus-bar, design factor is focused on the deformation of die-land by drawing force and shrink fit. In this paper, to determine shrink fit value is analyzed by automatic shrink fit analysis program, APDL/UIDL language in a commercial FEM package, ANSYS, has been developed that enables optimal design of the dies taking into account the elastic deflections generated in shrink fitting the die inserts and that caused by the stresses generated in the process and by using DEFORM software for drawing process analysis. This data can be processed as load input data for a finite element die-stress analysis. Process simulation and stress analysis are thus combined during the drawing die design. The stress analysis of the dies is used to determine optimized dimension of die-land.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2007.11a
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• pp.71-76
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• 2007

본 논문에서는 고 연색성의 실시간으로 색온도 제어 가능한 승강기용 조명제품 개발을 위하여 제품에 사용될 LED Package를 제작하고 고연색성 실현을 위한 색온도 제어 기초실험을 행하였다. 그리고 20W 급의 LED 광원모듈 구동회로와 색온도 제어를 위한 제어회로를 설계하였다. 또한 음영 제거 및 글레어 차단, 효과적인 광색혼합을 위하여 확산배광을 달성하기 위한 R, G, B, A, W LED의 최적 배치 및 렌즈의 광학설계를 수행하였고 LED에서 발생하는 열을 효과적으로 발산하여 LED 조명모듈의 온도를 낮추기 위한 방열설계를 실시하였다.

• Journal of Ocean Engineering and Technology
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• v.25 no.2
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• pp.127-133
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• 2011

The following Technology Report was written with respect to recent offshore technology development. This report was prepared with the purpose of suggesting recent offshore technology and upcoming visions by describing the principles of an offshore drilling operation, the NL Tensioner Cylinder Package R & D, and the general technology related to three offshore patent areas, as major contents.

• Journal of electromagnetic engineering and science
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• v.10 no.3
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• pp.150-157
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• 2010

We proposed a $4{\times}8$ array antenna with aperture-coupled patch antenna elements. The antenna was designed for 60 GHz operation and fabrication on the low-temperature cofired ceramic(LTCC) substrate($\varepsilon_r$=5.8). The feedline with the stub was designed to enhance the radiating element bandwidth and the transition characteristics between the waveguide (WG) and microstrip line(MSL). Through the optimization of the antenna and feedline geometry, the antenna gain and the performance of the 10 dB bandwidth were 20.2 dBi and 13 % up, respectively. The measured results agreed with the simulated ones.