• 제어로봇시스템학회:학술대회논문집
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• 1994.10a
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• pp.634-637
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• 1994

This paper presents a CMAC network based controller on the basis of Lyapunov theory. CMAC network is employed to approximate and to compensate the uncertainties induced by inaccurate modelling of the system. For the improvement of robustness under the bounded disturbances and the approximation error of the CMAC, the adaptation scheme with a deadzone and an additional control input are developed.

• Proceedings of the KIEE Conference
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• 1989.11a
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• pp.397-400
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• 1989

This study is to design a method of parameter estimation for a second order linear time invarient system of self-tuning controller utilizing the neural network theory proposed by Hopfield. The result is compared with the other methods which are commonly used in controller theories.

• Journal of the Korean Data and Information Science Society
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• v.24 no.3
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• pp.659-667
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• 2013

If the regression model or the propensity model is correct, the unbiasedness of the estimator using doubly robust imputation can be guaranteed. Using a neural network instead of a logistic regression model for the propensity model, the estimators using doubly robust imputation are approximately unbiased even though both assumed models fail. We also propose a doubly robust estimator of ratio form using population information of an auxiliary variable. We prove some properties of proposed theory by restricted simulations.

• International Journal of Fuzzy Logic and Intelligent Systems
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• v.9 no.4
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• pp.294-300
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• 2009

The neural network with radial basis function is introduced for position tracking control of AC servo drive with the existence of system uncertainties. An adaptive robust term is applied to overcome the external disturbances. The proposed controller is implemented on a high performance digital signal processing DSP TMS320C6713-300. The stability and the convergence of the system are proved by Lyapunov theory. The validity and robustness of the controller are verified through simulation and experimental results

• Journal of the Korean Physical Society
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• v.73 no.9
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• pp.1385-1392
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• 2018

A network with coupled biological neurons provides various forms of collective synchronous dynamics. Such phase-locking dynamics states resemble eigenvectors in a linear coupling system in that the forms are determined by the symmetry of the coupling strengths. However, the states behave as attractors in a nonlinear dynamics system. We here study the collective synchronous dynamics in a neural system by using a novel theory. We exhibit how the period and the stability of individual phase-locking dynamics states are determined by the characteristics of synaptic couplings. We find that, contrary to common sense, the firing rate of a synchronized state decreases with increasing synaptic coupling strength.

• Journal of Korea Game Society
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• v.15 no.1
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• pp.171-184
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• 2015

Looking at the existing game-related research, innumerable researches such as game acceptance, user satisfaction, continuance intention, wold-of-mouse intention have been carried out. However, there was no cases that applying the concept of service recovery in game researches. The purpose of this study is to evaluate the impact on the characteristic of the mobile social network game that based on domestic mobile social network game platform which focusing on KakaoTalk games on the service recovery. In addition, the study analyzed the characteristic factors of mobile social network game on the basis of Organizational Equity Theory and Innovation Diffusion Theory to identified the causal relationship between those factors and service recovery. As a result, except the independent variable-compatibility, all of the characteristics factors of mobile social network game showed direct or indirect effects on service recovery. The results of this study are expected as a reference for presenting a new business model, reducing risk factors and enriching the related research of the gaming industry.

• 한국HCI학회:학술대회논문집
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• 2009.02a
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• pp.799-810
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• 2009

전 세계적으로 노령화 문제가 사회적 이슈로 대두되고 있는 가운데, 노인이 느끼는 전반적인 삶의 질 (Quality of Life, QoL) 이 하락하는 문제가 사회 전반에 걸쳐 중요한 문제로 인식되고 있다. 이에 다양한 형태로 발생하고 있는 노인들의 문제를 해결하기 위하여 노인학, 사회 복지학 등의 분야에서 많은 연구가 진행되고 있다. 이 중 노인의 사회적 관계 (Social Network, SN) 를 강화, 확장하여 노인의 삶의 만족도 향상을 추구하고자 하는 연구를 찾아볼 수 있다. 이러한 관점에서 노인의 사회적 관계를 인터넷을 이용해 개선함으로써, 노인의 삶의 질을 향상시키고자 하는 것이 본 연구의 궁극적인 목표이다. 이에 본 연구의 세부적인 목적은 현재 젊은 층을 중심으로 많이 사용되고 있는 SNS 를 노인들이 사용하지 않는 이유에 대한 분석, 노인을 위한 SNS 의 핵심적인 기능적, 서비스적 요소를 파악하는데 있다. 이를 위해 현재 인터넷을 잘 활용하고 있는 60 세 이상의 노인 22 명을 대상으로 개별 인터뷰, 참가자가 사용하는 서비스 분석, FGI 의 3 가지 방식으로 데이터를 수집하였다. 이후 수집한 데이터를 이용하여 정성적 분석 방법으로 Casual Network 를 도출하였으며, 정량적 분석 방법인 Laddering 분석으로 Hierarchical Map 도출하여 비교하였다. 또한 도출된 결과가 노인들만의 특징인지를 파악하기 위하여 대학생, 직장인 각 10 명씩을 대상으로 노인을 대상으로 한 연구 방식과 동일한 방법으로 데이터를 수집, 분석 하였다. 최종적으로 본 연구는 사회감성적 선택 이론 (Socioemotional Selectivity Theory, SST)를 바탕으로 인터넷에서의 Social Network 활동도 오프라인과 유사한 특징을 가지고 있으며, 현재 친하게 지내고 있는 사람들을 중심으로 SN 을 강화시키려 하는 강화형 타입과 새로운 SN을 생성하기 위하여 노력하는 확장형 타입으로 구분할 수 있었다. 추후 이러한 특징들을 반영하여 노인들을 위한 SNS 가 지녀야 할 기능적, 시스템적 요소를 제안하고, 추후 연구 및 SNS 개발과 관련한 계획을 정리하였다.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.3
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• pp.2178-2184
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• 2015

With the development of wireless network technologies, mobile users may use various networks easily and expect more advanced services. On the other hand, it may bring on some problems with network resource management that should lead the service provider to improve the current service quality and manage the network resource efficiently. This paper proposes the optimized radio resource management (RRM) scheme that integrates the Grey Relational Analysis (GRA) and game theory. The first applies the GRA to determine the Grey Relation Coefficient (GRC) factors that represent the network preference, and the network provider then selects the requested service that provide maximum payoff through Nash Equilibrium. Six requested services that have one application service among four different types of service classes were considered and the game was played repeatedly. In WiMAX, WLAN 1 and WLAN 2 game, the maximum payoff of each players was 93, 90.6 and 92.8 respectively. The experimental results show that every requested service can be selected by the network provider. Consequently, the proposed radio resource management mechanism is more effective in heterogeneous wireless networks.

• Journal of the Korean Association of Geographic Information Studies
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• v.11 no.3
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• pp.80-91
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• 2008

The Purpose of this study is the applicaion of social network analysis for expanding the use of spatial data in local government. Spatial data generated from UIS projects play very important roles as a means of supporting decision making and solving complicated urban problems, but the utilization of the spatial data has not reach the expected level, considering to the huge amount of investment. Accordingly, there should be efforts in efficient management of spatial data, establishment of a sharing system, and expanded utilization of spatial data. Social network analysis applied to this research is a theory that explains the behaviors and patterns of units forming the system and measures distances between nodes, strength, etc. based on relations among nodes forming the network and the structural characteristics of the network. According to the results of surveying civil servants who were using spatial data on Busan Metropolitan City, obstacles to the sharing of spatial data were mostly non technical factors related to data users' attitude and their relations with circumstances. In order to expand the use of spatial data, this study performed social network analysis that applied the theory of planned behavior and examined the flow of spatial data, and by doing so, we analyzed related personnel's perception, identified obstacles to data sharing, and suggested a framework for promoting the expanded utilization of spatial data.

• The Journal of Korean Academic Society of Nursing Education
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• v.10 no.1
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• pp.54-63
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• 2004

The purpose of this study is to identify the factors that influence stress experienced by nursing students and to provide a perceived causal structure model among these variables. The ultimate goal of this study is to develop efficient guidance to clinical nursing education in this population. This study intends to apply perceived causal structure: network analysis method which was developed by Kelly(1983), and has been applied in nursing research. This method is selected to show dynamic relationship of stressor using network method. Data was collected from convenient sample of 186 junior college nursing students who had the clinical practice experience during 10 weeks. Data collection and analysis was conducted in 2 steps from December, 9, 2002 to February, 8, 2003. Step 1.: Data was collected using literature review(10 articles) to identify the causes of stress. Nine causes of stress were extracted. Step 2.: As perceived casual structure network study, data was collected using questionnaires which included 9 extracted cause and stress. The questionnaire contained a 10 X 10 grid table with 10 causes and effects printed. In network analysis, 'Yes' was scored as 1, 'No' was scored as 0, and the mean(maximum 1, minimum 0) was calculated. Construction of the network under inductive eliminative analysis which stopped the construction of the network when the consensual agreement level dropped near 50% was proceeded by adding causes in order of the mean rating level. In this study, construction of the final network was stopped by consensual agreement level of 52% of the total subjects. The results are summarized as follows : Step 1: Investigation of the causes of stress ; The extracted causes of stress from quality data was identified 9 categories ; negative nurse, lack of clinical practice opportunity, ambiguous role, negative patient, lack of nursing knowledge and skill, difficult of personal relations, inefficient clinical practice guidance, gap of theory and practice, lack of support. Step 2 : Construction of the perceived causal structure model ; 1) The most central cause of stress is ambiguous role in the systems of causation. 2) The distal cause of stress is inefficient clinical practice guidance 3) The causes that have a number of outgoing link are negative nurse, ambiguous role. 4) The causes that have a number of incoming link are ambiguous role, gap of theory- practice, lack of clinical practice opportunity, lack of nursing knowledge- skill. 5) There is a mutual relationship between stress and difficult of personal relations, stress and ambiguous role, ambiguous role and negative nurse, ambiguous role and lack of clinical practice opportunity, ambiguous role and lack of nursing knowledge-skill, lack of nursing knowledge-skill and gap of theory- practice. In conclusion, the network suggests that the first centre cause is related on ambiguous role and the second on negative nurse, inefficient clinical practice guidance in the systems of causation