• Journal of Korea Water Resources Association
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• v.40 no.1 s.174
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• pp.25-38
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• 2007

A grid-based urban surface runoff model for simulating the temporal variation and spatial distribution of overland flow in a drainage area was developed. The process of routing of overland flow is modeled by the nonlinear storage equation which is composed of the continuity equation and the Manning's equation. For model operation, the drainage area is divided into grid areas, and spatially distributed topographical and hydrological information for model inputs is provided. Then overland flow is routed for each of the discretized cells of the area. In order to test the applicability of this model, temporal variations and spatial distributions of flow depth and overland flow was simulated in a fictitious and a real urbanized Kunja drainage area. Results indicate that the model can simulate reasonably well the urban runoff hydrograph.

• Korean journal of communication and information
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• v.36
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• pp.254-286
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• 2006

The purpose of the present study is to examine how visitors of personal web sites evaluate self presentation styles. We hypothesized that visitors' gender, self construals, and self esteem would influence the evaluation (likeability and perceived competence) of the self presentation styles (bragging or positive presentation). The hypothesized models were tested with structural equation modeling. Gender differences among the constructs were also examined through latent mean analysis. The results revealed that females tended to have higher interdependent self construal than males. And the male and the female students showed higher likeability toward the self presentations of the other gender. Regarding perceived competence, women and men perceived the other gender more competent, and especially, women perceived men's bragging presentation more competent. Self construals and self esteem, however, did not show any significant effects, which were inconsistent with the results of the previous studies conducted with offline self presentation styles. One of the main implications of this study is that visitors' gender, among other things, is the most infueltial factor in perceiving and evaluating others' self presentation through personal web sites.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.18 no.3
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• pp.291-302
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• 2005

Due to the importance of the parameter in structural response, the uncertain elastic modulus was located at the center of stochastic analysis, where the response variability caused by the uncertain system parameters is pursued. However when we analyze the so-called stochastic systems, as many parameters as possible must be included in the analysis if we want to obtain the response variability that can reach a true one, even in an approximate sense. In this paper, a formulation to determine the statistical behavior of in-plane structures due to multiple uncertain material parameters, i.e., elastic modulus and Poisson's ratio, is suggested. To this end, the polynomial expansion on the coefficients of constitutive matrix is employed. In constructing the modified auto-and cross-correlation functions, use is made of the general equation for n-th moment. For the computational purpose, the infinite series of stochastic sub-stiffness matrices is truncated preserving required accuracy. To demons4rate the validity of the proposed formulation, an exemplary example is analyzed and the results are compared with those obtained by means of classical Monte Carlo simulation, which is based on the local averaging scheme.

• Journal of the Korean Data and Information Science Society
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• v.26 no.2
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• pp.323-334
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• 2015

he current VaR model based on the J.P. Morgan's RiskMetrics structurally can not reflect the future economic situation. In this study, we propose a One-factor model resulting from the Wiener stochastic process decomposed into a systematic risk factor and an idiosyncratic risk factor. Therefore, we are able to perform a preemptive risk management by means of reflecting the predicted common risk factors in the model. Stocks in the portfolio are satisfied with the independence to each other because the common factors are fixed by the predicted value. Therefore, we can easily determine the investment in each stock to minimize the variance of the portfolio. In addition, the portfolio VaR is decomposed into the sum of the individual VaR. So we can effectively implement the constitution of the portfolio to meet the target maximum losses.

• Journal of the Korea Society of Computer and Information
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• v.18 no.5
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• pp.121-131
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• 2013

The Internet website has become an effective marketing vehicle for travel agencies. The objective of this study is to examine theoretical relationships between travel agency's website quality, customer satisfaction, and repurchase intention. Usable data was obtained from the 373 respondents using travel agency's website within one year. Hypotheses are tested using structural equation modeling. The results indicate that travel agency's website quality has an effect on customer satisfaction as well as repurchase intention. The impact of information quality on customer satisfaction and repurchase intention is the most important factor, followed by service quality and design quality among the factors of the quality of a travel agency's website.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2006.05a
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• pp.265-269
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• 2006

본 논문에서는 간헐성 카오스를 이용한 장해물 회피 문제를 다루었다. 본 본문은 Chua's 방정식을 이용한 카오스 회로를 이동 로봇에 내장하여 카오스 이동 로봇을 구성하고 이 카오스 이동 로봇이 어느 임의 평면을 카오스 궤적을 가지고 주행하다가 고정 장애물, 또는 은닉 이동 장애물을 만나면 이를 회피하는 알고리즘을 제시하였다. 간헐성 카오스 로봇의 장애물 회피의 경우 고정 장애 and, 이동 장애물, 장애물 위험에 따른 로봇의 접근 등에서 잘 회피됨을 확인하였으며 만족할 만한 결과를 얻었다.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.6
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• pp.2700-2706
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• 2013

The purpose of this study was to investigate the casual relationship between school adjustment, self-esteem and life satisfaction and academic achievement in elementary school students. This study utilized the NYPI's longitudinal data collected on elementary school students nationwide for 2012. Equation Modeling analysis was used to analyze 2,254 5th grade students' data. It was found that school adjustment was positively correlated with self-esteem, life satisfaction and academic achievement. School adjustment was directly associated with academic achievement. It was also confirmed that school adjustment indirectly explained academic achievement through self-esteem and life satisfaction. Future research directions and implications to teacher and institutions were discussed.

• Journal of Digital Convergence
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• v.16 no.1
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• pp.103-116
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• 2018

In this study, we investigated the influence of smart factory's implementing energy management system on innovation resistance and work performance. We surveyed and analyzed 211 employees of system construction companies in the metropolitan area. In order to increase the introduction performance through diffusion of the energy management system, it is found that it is important to support the organizational-level management strategy to reduce the user's resistance to innovation. In conclusion, this study has implications for positively leading to the efficiency and management performance of the manufacturing process of the manufacturing enterprises, and it is necessary to follow - up studies considering the characteristics of the energy management system and the expansion of the research scope in the future.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.30 no.6
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• pp.21-30
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• 2002

A preconditioned Navier-Stokes code was parallelized by the domain decomposition technique, and the accuracy of the parallelized code was verified through a comparison with the result of a sequential code and experimental data. Parallel performance of the code was examined on a Myrinet based PC-cluster and a Fast-Ethernet system. Speed-up ratio was examined as a major performance parameter depending on the number of processor and the network communication topology. In this test, Myrinet system shows a superior parallel performance to the Fast-Ethernet system as was expected. A test for the dependency on problem size also shows that network communication speed in a crucial factor for parallel performance, and the Myrinet based PC-cluster is a plausible candidate for high performance parallel computing system.

• Proceedings of the KIEE Conference
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• 1997.07a
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• pp.174-176
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• 1997

편미분 방정식의 형태로 나타나는 많은 전자기장 문제들을 유한요소법이나 유한차분법 등의 수치해석적 방법으로 해결하려는 경우 시스템 행렬을 구성하게 된다. 이때 해석영역의 요소수가 많을수록 행렬의 조건수(condition number)는 다항식(polynomial) 증가를 갖게 되며, 이는 풀어야 할 선형시스템에서 반복 연산 과정의 속도를 떨어뜨리는 결과를 야기한다. 이러한 결과를 wavelet을 기저 함수로 쓰게 되면, 더 높은 분해능(resolution)의 해를 유한 요소법이나 유한 차분법에서와 같은 요소 분할 과정이 없이 Mallat 변환이라는 간단한 과정을 통해 구할 수 있으며, 본 논문에서는 Daubechies의 wavelet 함수를 기저 함수로 사용하여 전자기장 문제에 적용함으로서 수치해석에 있어서 wavelet 함수의 적용이 많은 장점을 갖고 있음을 보인다.