• Journal of Digital Convergence
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• v.14 no.6
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• pp.119-132
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• 2016

This study examined the concept and usage moderated mediating model in structural equation modeling. The theoretical model and hypothesis were developed based on the Location-Based application's Expectancy disconfirmation, Location-Based application's satisfaction, Location-Based application's continuous usage intention, service trust. The statistical results of the two model were compared: one was free model(positive/negative) and the other was the Moderated Mediating Model(positive/negative). A structure equation model analysis was carried out to test the research model. Further studies are necessary to Ssupport the research hypotheses.

• Journal of Digital Convergence
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• v.14 no.6
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• pp.425-430
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• 2016

The goal of this study is to explore the factors that influence on intention to use UHDTV Service. Research problems has been designed to Structural equation model by Technology Acceptance Model. The Perceived quality, Price sensitivity, Innovativeness are adopted as independent variables. And Perceived usefulness, Perceived ease of use are adopted as intervening variables. A result of analysis, Perceived quality and Price sensitivity influenced the Intention to use via Perceived usefulness and Perceived ease of use. But in case of Innovativeness, it did not influence the Perceived usefulness while it influenced the Perceived ease of use. Meanwhile, the influence of Perceived quality to Perceived usefulness had more impact than the other path between the other factors.

• Journal of the Korean Institute of Telematics and Electronics S
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• v.36S no.7
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• pp.50-61
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• 1999

\In this paper, we consider the optimal scheduling of detection and tracking parameters in phased array radars to minimize the radar energy required for track maintenance in a cluttered environment. We develop a mathematical model of target detection induced by a search process in phased array radars. In the mathematical development, we take into account the effect of unwanted measurements that may have originated from clutter or false alarms in the detection process. We use and analytic approximation of the modified Riccati equation of the probabilistic data association (PDA) filter to take into account the effect of clutter interference in tracking. Based on the search process and the tracking models, we formulate the optimal scheduling problem into a nonlinear optimal control problem. We solve a constrained nonlinear optimization problem to obtain the solution of the optimal control problem.

• Journal of The Korean Society of Agricultural Engineers
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• v.52 no.1
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• pp.25-31
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• 2010

네덜란드 브리젠빈 하폐수처리장 최종방류수의 $NH_4$-N 및 TN(Total Nitrogen)농도를 방류수 수질기준인 각각 4 mg/L와 10 mg/L에 맞추기 위한 최적의 운전조건을 도출하기 위해 다양한 제어시스템이 시뮬레이션 되었다. 본 연구에 사용된 모델은 IWA(International Water Association) 활성슬러지 모델 No.1 (ASM No.1)이었고, GPS-X가 시뮬레이터로 사용되었다. 모델링을 위한 매개변수 민감도 분석결과 ASM No.1의 총 19개 매개변수 중 8개 변수 ($Y_H$, ksh, koh, $b_H$, ${\mu}_a$, $k_{NA}$, kh, ka)가 방류수 수질에 영향을 미치는 것으로 조사되었고 이들 매개변수에 대해 보정을 수행하여 사용하였다. SRT, 호기/무산소기간, 외부탄소원 주입시간 변화에 따른 방류수질 변화를 시뮬레이션하였는데, 호기/무산소 11h/1h인 조건에서 SRT가 20일에서 25일로 증가되면 $NH_4$-N가 5.0 mg/L에서 2.9 mg/L로 감소되었고 호기/무산소 2h/1h의 조건에서는 SRT증가에 따라 $NH_4$-N은 큰 감소를 보이지만, 바이패스되는 유입수량의 감소로 탈질율이 낮아 방류수 TN이 11.1~11.5 mg/L로 예측되는 결과가 도출되었다. 탈질율을 높이기 위한 아세트산 주입은 동일한 양의 아세트산을 무산소 전기간 (1h)동안 균일 주입하는 것 보다는 무산소 초기 15분내에 주입하는 것이 효율적인 것으로 나타났다.

• Journal of Broadcast Engineering
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• v.24 no.2
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• pp.264-272
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• 2019

In this paper, we propose a 3D human body reconstruction and refinement method from the frames extracted from a video to obtain natural and smooth motion in temporal domain. Individual frames extracted from the video are fed into convolutional neural network to estimate the location of the joint and the silhouette of the human body. This is done by projecting the parameter-based 3D deformable model to 2D image and by estimating the value of the optimal parameters. If the reconstruction process for each frame is performed independently, temporal consistency of human pose and shape cannot be guaranteed, yielding an inaccurate result. To alleviate this problem, the proposed method analyzes and interpolates the principal component parameters of the 3D morphable model reconstructed from each individual frame. Experimental result shows that the erroneous frames are corrected and refined by utilizing the relation between the previous and the next frames to obtain the improved 3D human reconstruction result.

• Proceedings of the Korea Water Resources Association Conference
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• 2023.05a
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• pp.150-150
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• 2023

기작기반의 역학적 모델과 자료기반의 딥러닝 모델은 수질예측에 다양하게 적용되고 있으나, 각각의 모델은 고유한 구조와 가정으로 인해 장·단점을 가지고 있다. 특히, 딥러닝 모델은 우수한 예측 성능에도 불구하고 훈련자료가 부족한 경우 오차와 과적합에 따른 분산(variance) 문제를 야기하며, 기작기반 모델과 달리 물리법칙이 결여된 예측 결과를 생산할 수 있다. 본 연구의 목적은 주요 상수원인 댐 저수지를 대상으로 수심별 수온과 탁도를 예측하기 위해 기작기반과 자료기반 모델의 장점을 융합한 PGDL(Process-Guided Deep Learninig) 모델을 개발하고, 물리적 법칙 만족도와 예측 성능을 평가하는데 있다. PGDL 모델 개발에 사용된 기작기반 및 자료기반 모델은 각각 CE-QUAL-W2와 순환 신경망 딥러닝 모델인 LSTM(Long Short-Term Memory) 모델이다. 각 모델은 2020년 1월부터 12월까지 소양강댐 댐 앞의 K-water 자동측정망 지점에서 실측한 수온과 탁도 자료를 이용하여 각각 보정하고 훈련하였다. 수온 및 탁도 예측을 위한 PGDL 모델의 주요 알고리즘은 LSTM 모델의 목적함수(또는 손실함수)에 실측값과 예측값의 오차항 이외에 역학적 모델의 에너지 및 질량 수지 항을 제약 조건에 추가하여 예측결과가 물리적 보존법칙을 만족하지 않는 경우 penalty를 부가하여 매개변수를 최적화시켰다. 또한, 자료 부족에 따른 LSTM 모델의 예측성능 저하 문제를 극복하기 위해 보정되지 않은 역학적 모델의 모의 결과를 모델의 훈련자료로 사용하는 pre-training 기법을 활용하여 실측자료 비율에 따른 모델의 예측성능을 평가하였다. 연구결과, PGDL 모델은 저수지 수온과 탁도 예측에 있어서 경계조건을 통한 에너지와 질량 변화와 저수지 내 수온 및 탁도 증감에 따른 공간적 에너지와 질량 변화의 일치도에 있어서 LSTM보다 우수하였다. 또한 역학적 모델 결과를 LSTM 모델의 훈련자료의 일부로 사용한 PGDL 모델은 적은 양의 실측자료를 사용하여도 CE-QUAL-W2와 LSTM 보다 우수한 예측 성능을 보였다. 연구결과는 다차원의 역학적 수리수질 모델과 자료기반 딥러닝 모델의 장점을 결합한 새로운 모델링 기술의 적용 가능성을 보여주며, 자료기반 모델의 훈련자료 부족에 따른 예측 성능 저하 문제를 극복하기 위해 역학적 모델이 유용하게 활용될 수 있음을 시사한다.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.12
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• pp.8157-8164
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• 2015

The purpose of this study is to find out how a parents' mental characteristics with preschool children(self-esteem, self-efficacy, depression) has effect on a mother's parenting stress by the medium of a father's parenting stress. The fourth year data of The Korean Children Panel of the KICCE(2011) was used, and the collected data was fathers and mothers with 1,754 children who are more than 35 months but not more than 42 months. For data analysis, analysis of frequency and correlation analysis were carried out using SPSS 18.0, and they were analysed with Structural Model to observe the relationship of each variable and influence, and it was found that the goodness of fit of the model was outstanding. As a result, the psychological traits of fathers impact directly on mothers' parenting stress. Mothers' psychological features increased mothers' parenting stress by a medium of fathers' parenting stress. The study showed that fathers' parenting stress that is a mediator variable performed a role as a mediator variable.

• The Journal of the Korea Contents Association
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• v.16 no.2
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• pp.566-579
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• 2016

The purpose of this study was to analyze mediating effect of resilience and daily spiritual experiences in the relationship of stress situations and subjective well-being of Christian college students. The subjects of this study were 157 Christian college students in a certain University which is located in Seoul, and mediating effect were analyzed through structural equation model. As a result of the analysis, first, there was a significant negative correlation between perceived stress and subject well-being. Second, resilience and spiritual experience had a full mediating effect on the relationship of perceived stress and subjective well-being. Third, in the relationship of perceived stress and subjective well-being, indirect effect through resilience has a greater mediating effect than spiritual daily experience. Implications of these results were concluded that spiritual daily experience of Christian college students is a significant variable in terms of stress and happiness. Apart from spiritual experience, however, resilience also could be a very important variable that mediates stress and happiness for Christian college students. In addition, suggestions for future research were discussed.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.8
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• pp.200-209
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• 2017

This study examined the mediating effect of depression on the relationship between over-control parenting styles and mobile phone dependency among children. The 5th-year longitudinal data from the Korean Children & Youth Panel Survey (KCYPS) were collected from 4th grade elementary school students. The data were analyzed by the structural equation modeling and bootstrapping. The results of this study were as follows. First, there is a positive path from over-control parenting styles to depression, from depression to mobile phone dependency, and from over-control parenting styles to mobile phone dependency. Second, depression had a mediating effect on the association between over-control parenting styles and mobile phone dependency. Based on these results, more study of elementary school students' reliance on cell phones is needed.

• Journal of Convergence for Information Technology
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• v.10 no.10
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• pp.150-160
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• 2020

The purpose of this study was to test the effect of socially-perfectionism on depression by mediating ambivalence over emotional expressiveness and experiential avoidance. For this purpose, 201 participants across the country conducted the survey, a measure of MPS, AEQ-K, AAQ-II, CES-D. The descriptive statistics, Pearson correlation, path coefficient were conducted using SPSS 23.0. The indirect effect was examined using bootstrap in PROCESS Macro. The results of the study are as follows. First, all the variables had meaningful positive correlations. Secondly, When socially-perfectionism affects depression, ambivalence over emotional expressiveness, and experiential avoidance were mediated. As a result, the implications and limitations of the study were discussed.