• Proceeding of EDISON Challenge
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• 2014.03a
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• pp.1-13
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• 2014

Potential Energy Surface(PES)를 양자 계산을 통해 알아내는 것은 화학 반응을 이해하는 데에 큰 도움이 된다. 이를테면 Transition State(TS)의 configuration을 알 수 있고, 따라서 reaction path와 활성화 에너지 값을 예측하여, 진행시키고자 하는 화학반응의 이해를 도울 수 있다. 하지만 PES를 그리기 위해서는 해당 분자의 다양한 configuration에 대한 singlet point energy 계산이 필요하기 때문에, 계산적인 측면에서 많은 비용을 요구한다. 따라서 product와 reactant의 구조와 같은 critical point의 정보를 이용하여 최소한의 configuration을 sampling하여 전체 PES를 재구성하는 기계학습 알고리즘을 개발하여 다차원 PES 상에서의 화학반응의 예측을 가능하게 하고자 한다. 본 연구에서는 Barbaralane의 두 안정화 된 구조의 critical point로 하여 이 주변을 random normal distribution하여, B3LYP/6-31G(d) level의 DFT 계산을 통해 relaxed scanning하여 구조와 에너지를 구하였으며, 이 정보를 Support Vector Regression(SVR) 알고리즘을 적용하여 PES를 재구현하였으며, 반응경로와 TS의 구조 그리고 활성화 에너지를 구하였다. 또한 본 기계학습 알고리즘을 바닥상태에서 일어나는 반응이 아닌, 들뜬 상태와 전자 구조가 변하는 화학반응, avoid crossing, conical intersection과 같은 Non-adiabatic frame에서 일어나는 현상에 적용 가능성을 논하고자 한다.

• Journal of The Korean Society of Agricultural Engineers
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• v.60 no.4
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• pp.83-91
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• 2018

Land reclamation, coastal construction, coastline extension and port construction, all of which involve dredging, are increasingly required to meet the growing economic and societal demands in the coastal zone. During the land reclamation, a portion of landfills are lost from the desired location due to a variety of causes, and therefore prediction of sediment transport is very important for economical and efficient land reclamation management. In this study, laboratory disposal tests were performed using an open channel, and suspended sediment transport was analyzed according to flow velocity and grain size. The relationships between the average and standard deviation of the deposition distance and the flow velocity were almost linear, and the relationships between the average and standard deviation of deposition distance and the grain size were found to have high non-linearity in the form of power law. The deposition distribution of sediments was demonstrated to have log-normal distributions regardless of the flow velocity. Based on the experimental results, modeling of suspended sediment transport was performed using deep neural network, one of deep learning techniques, and the deposition distribution was reproduced through log-normal distribution.

• Proceedings of the KIEE Conference
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• 2001.11b
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• pp.293-295
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• 2001

This paper describes an interactive educational software developed at Konkuk University. This software provides an educational opportunity for electrical engineering students at the junior level to expand their knowledge about fault analysis in power systems. The developed educational software has three main modules: 1) Z-building, 2) setting the type and location of the fault, 3) displaying the calculated fault currents, according to the given simulation options. The main features of this tool are the diversification of acquisition network data, the function of learning about the z-building procedures, and the dynamic display function of state vectors-all voltage/current phasor. To verity the effectiveness of the developed educational software, some case studies are performed.

• Proceedings of the KIEE Conference
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• 2002.07d
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• pp.2407-2409
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• 2002

강화학습이란 에이전트가 알려지지 않은 미지의 환경에서 행위와 보답을 주고받으며, 임의의 상태에서 가장 적절한 행위를 학습하는 방법이다. 만약 강화학습 중에 에이전트가 과거 문제들을 해결하면서 학습한 환경에 대한 지식을 이용할 수 있는 능력이 있다면 새로운 문제를 빠르게 해결할 수 있다. 이런 문제를 풀기 위한 방법으로 에이전트가 과거에 학습한 여러 문제들에 대한 환경 지식(Domain Knowledge)을 Local state feature라는 기억공간에 학습한 후 행위함수론 학습할 때 지식을 활용하는 방법이 연구되었다. 그러나 기존의 연구들은 주로 2차원 공간에 대한 연구가 진행되어 왔다. 본 논문에서는 환경 지식을 이용한 강화학습 알고리즘을 3차원 공간에 대해서도 수행 할 수 있도록하는 개선된 알고리즘을 제안하였으며, 제안된 알고리즘의 유효성을 검증하기 위해 초소형 비행체의 항공운항 학습에 대해 모의실험을 수행하였다.

• Research in Community and Public Health Nursing
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• v.17 no.4
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• pp.552-562
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• 2006

Purpose: This study was conducted to describe the state of middle school students' addicted use of a cellular phone and their psychosocial characteristics and to examine differences in psychosocial factors as impulsivity, stress, anxiety and classroom attitudes according to the level of addiction. Method: As the subjects of this study, 747 middle school students who use a cellular phone in B Metropolitan City were selected through stratified random sampling, and they were asked to answer a self-administered study questionnaire. Data were analyzed using frequency, descriptive statistics, $x^2-test$, t-test, and one-way ANOVA. Results Among the respondents, 15.7% fell into the addicted user group while 56.0% fell into the dependent user group and 28.3% turned out to be non-addicted users. The levels of impulsivity, stress and anxiety were higher in the addicted user group than in the dependent user group and the non-addicted user group. The addicted user group also showed a very bad learning attitude. Conclusion: Addiction to the use of a cellular phone, which may have negative influences on the users' psychosocial characteristics, needs to be detected earlier, and preventive education should be offered in order to prevent such addiction.

• Current Optics and Photonics
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• v.1 no.4
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• pp.315-324
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• 2017

In recent years, multicast services such as high-definition television (HDTV), video conferencing, interactive distance learning, and distributed games have increased exponentially, and wavelength-division multiplexing (WDM) networks are considered to be a promising technology due to their support for multicast applications. Multicast survivability in WDM networks has been the focus of extensive attention since a single-link failure in an optical network may result in a massive loss of data. But the improvement of network survivability increases energy consumption due to more resource allocation for protection. In this paper, an energy-efficient multicast algorithm (EEMA) is proposed to reduce energy consumption in WDM networks. Two cost functions are defined based on the link state to determine both working and protection paths for a multicast request in WDM networks. To increase the number of sleeping links, the link cost function of the working path aims to integrate new working path into the links with more working paths. Sleeping links indicate the links in sleep mode, which do not have any working path. To increase bandwidth utilization by sharing spare capacity, the cost function of the protection path is defined to use sleeping fibers for establishing new protection paths. Finally, the performance of the proposed algorithm is evaluated in terms of energy consumption, and also the blocking probability is evaluated under various traffic environments through OPNET. Simulation results show that our algorithm reduces energy consumption while maintaining the quality of service.

• Journal of Biomedical Engineering Research
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• v.17 no.3
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• pp.387-394
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• 1996

This paper presents a Neural Network Identification(NNI) method for modeling of highly complicated nonlinear and time varing human system with a pneumatically driven mock circulatory system of Left Ventricular Assist Device(LVAD). This system consists of electronic circuits and pneumatic driving circuits. The initiation of systole and the pumping duration can be determined by the computer program. The line pressure from a pressure transducer inserted in the pneumatic line was recorded System modeling is completed using the adaptively trained backpropagation learning algorithms with input variables, heart rate(HR), systole-diastole rate(SDR), which can vary state of system. Output parameters are preload, afterload which indicate the systemic dynamic characteristics. Consequently, the neural network shows good approximation of nonlinearity, and characteristics of left Ventricular Assist Device. Our results show that the neural network leads to a significant improvement in the modeling of highly nonlinear Left Ventricular Assist Device.

• Journal of the Korean earth science society
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• v.28 no.5
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• pp.620-634
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• 2007

The purpose of this study was to investigate the effectiveness of EarthComm implementation in the U.S. high schools in terms of demographic background including school size, urban/rural area, and teachers' teaching experiences. In addition, this study examined impact of students' higher-order thinking skills by using the visions of National Science Education Standards. Two modular of the EarthComm curriculum were used for this purpose with thirty one teachers and around thousand students involved across four states. Findings were that EarthComm did not significantly impact student achievement differentially in schools of varying sizes and school location, i.e., urban and rural areas. The years of teaching experiences did not impact student achievement scores for Module I but did significantly impact for Module II. It is noted that the two results seemingly conflict with each other similar to other research findings (Ferguson, 1998; Yager et al., 1988). Student higher-order thinking skills, on the other hand, were significantly improved as a result of studying with EarthComm. Implications were discussed at the end of the paper.

• Journal of Family Resource Management and Policy Review
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• v.18 no.2
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• pp.37-54
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• 2014

This study investigates fathers' demands for fathering education. Data from eight married, working men was collected through in-depth interviews. The interviews were intended to examine their father-role, working life, balance between work and family, and demand for the educational programs for fathers with particular regard to the themes, contents, and arrangement strategies they desire of the programs. The results show that fathers have a high demand for learning detailed methods of childrearing such as how to effectively sooth and play with their child(ren). Further, it was discovered that job flexibility is the major variable that determines a man's satisfaction with his parental role. Various information about possible arrangements of fathering education was collected from the interview data, such as desired themes, number of sessions, size of the educational program, volunteer role of participants, and focus of the course (e.g., many indicated interest in focusing on gender equality). This study reveals that greater detail, more effective contents, and efficient managerial strategies are required in fathering education in order to impart broader perspectives and knowledge about how to enhance the relationship between father and child(ren).

• Proceedings of the KIEE Conference
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• 1995.07b
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• pp.705-709
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• 1995

The objective of this study is to design a multi-layer neural network which controls the position of excavator's attachment. In this paper, a dynamic controller has been developed based on an error back-propagation(BP) neural network. Since the neural network can model an arbitrary nonlinear mapping, it was used as a commanded feedforward input generator. A PD feedback controller is used in parallel with the feedforward neural network to train the system. The neural network was trained by the current state of the excavator as well as the PD feedback error. By using the BP network as a feedforward controller, no a priori knowledge on system dynamics is need. Computer simulation results demonstrate such powerful characteristics of the proposed controller as adaptation to changing environment, robustness to disturbancen and performance improvement with the on-line learning in the position control of excavator attachment.