• Educational Technology International
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• 제15권2호
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• pp.89-115
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• 2014

This research aims to develop an elementary school English e-learning system based on the 'Self-determination theory (SDT)', which is widely applied to traditional face-to-face foreign language classes. The study also attempts to verify whether SDT-a traditional motivational theory that has been applied to face-to-face classes- is effective in an e-Learning environment with students who use this newly developed system. For the purposes of this project, the following three actions were carried out. First, a motivational strategy based on SDT was deduced. In SDT, the needs for autonomy, competence, and relatedness were introduced as basic psychological needs, and assumed that these three needs provided the natural motivation for learning, growth, and development. Second, an e-Learning system was created based on the deduced motivational strategy. Third, the system was implemented in 115 private tuition academies, and education was provided to 1,400 users for one year across the country. Afterwards, by surveying users, correlation between the role of the three psychological needs in learning English, and also the correlation between each need and motivation were investigated. Research results showed that traditional motivational theories used in face-to-face classes so far were effective in an e-Learning environment.

• 한국지능시스템학회논문지
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• 제7권1호
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• pp.45-53
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• 1997

This paper presents hybrid expert system for diagnosis of electric power transformer faults. The expert system diagnose and detect faults in oil-filled power transformers based on dissolved gas analysis. As the preprocessing stage, fuzzy information theory is used to manage the uncertainty in transformer fault diagnosis using dissolved gas analysis. The Kohonen neural network takes the interim results by applying fuzzy informations theory as inputs, and performs the transformer fault diagnosis. The Proposed system tested gas records of power transformers from Korea Electric Power Corporation to verify the diagnosis performance of transformer faults.

• 동력기계공학회지
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• 제7권1호
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• pp.60-67
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• 2003

This paper introduces basic study how to restrain the vibration of a four story shear structure. We have modeled a four story shear structure mathematically and have identified each parameters by experiment. We have gotten a reduced nominal model through modal analyzing method and the $H_{\infty}$ control theory is used in the control system design to get the robust controller. It's shown that the desirable performances is confirmed through the mathematical simulation. And a designed controller applying the $H_{\infty}$ control theory shows the good performance for the impulse disturbance through the simulation results. That is, the robustness of this control system is confirmed for the ability of disturbance rejection and modeling error.

• International Journal of Precision Engineering and Manufacturing
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• 제4권2호
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• pp.5-12
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• 2003

This study presents a solution to control a PMSM without sensors. The control method is the presented superposition principle. This method of sensorless theory is very simple to compute estimated angle. Therefore, computing time to estimate angle is shorter than other sensorless methods. The use of this system yields enhanced operations, fewer system components, lower system costs, efficient energy control system designs and increased efficiencies. A practical solution is described and its results are given in this study. The performance of a sensorless architecture allows an intelligent approach to reduce the complete system costs of digital motion control applications using the cheaper electrical sensorless motors. This paper deals with an overview of solutions in the sensorless PHSM control applications, whereby the focus will be the new sensorless controller and its applications.

• Geomechanics and Engineering
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• 제16권2호
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• pp.159-168
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• 2018

In this study, a real-time grouting management system based on the clogging theory was established to manage injection procedure in real time. This system is capable of estimating hydraulic permeability with the passage of time as the grout permeates through the ground, and therefore, capable of estimating real time injection distance and flow rate. By adopting the Controlled Injection Pressure (CoIP) model, it was feasible to predict the grout permeation status with the elapse of time by consecutively updating the hydraulic gradient and flow rate estimated from a clogging-induced alteration of pore volume. Moreover, a method to estimate the volume of the fractured gap according to the reduction in injection pressure was proposed. The validity of the proposed system was successfully established by comparing the estimated values with the measured field data.

• 한국통신학회논문지
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• 제32권4A호
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• pp.373-378
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• 2007

본 논문에서는 CR(Cognitive Radio)의 가장 적합한 인공지능 기술로 주목받고 있는 게임이론을 전력 제어 방식에 적용해 OFDM 시스템 기반의 사용효율과 효용에 대한 성능 평가 결과를 제시하였다. 사용자와 네트워크 동시 최적화를 위한 효용함수식을 정의했으며 모의실험을 통해 FOM(Figure of Merit)과 형평성(Fairness)에서 기존의 전력제어 방식보다 월등한 성능을 입증하였다. 또한 게임이론을 이용한 전력 제어 방식은 통신 환경을 인지하고 연산하여 적합한 최적의 서비스를 제공하는 CR의 여러 분야에 확장 적용 가능성을 제시하였다.

• 대한치과교정학회지
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• 제26권3호
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• pp.281-290
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• 1996

Edgewise bracket에 continuous straight archwire를 장착 했을 때 각 bracket에 발생 하는 force system은 statically indeterminate system이기 때문에 임상적으로 측정이 어렵다. 이에 본 연구는 linear beam theory를 도입하여 full arch에 straight wire가 장착된 경우 geometry(a/b), 재질, 단면의 모양, interbracket distance에 관계없이 발생 가능한 모든 상태를 설명할 수 있는 식을 유도하고 일례의 분석을 통하여 다음과 같은 결과를 얻었다. 1. Bilateral fixed beam의 양끝에서 발생하는 force system을 알 수 있는 계산식을 얻었다. 2. 이를 이용하여 continuous straight archwire가 장착된 경우 각 치아에 발생하는 force system을 알 수 있다. 3. Continuous straight archwire장착시 영구변형의 발생여부와 발생위치를 예측 할 수 있다.

• Ocean and Polar Research
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• 제28권2호
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• pp.163-173
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• 2006

The so called Antarctic Treaty System, started from the Antarctic Treaty in 1959, has gradually been enlarged into the concept of an international environmental regime, which has been included in not a few international institutions, treaties, conventions, and international non-governmental organizations (INGO). This kind of movement, as in the role of an international environmental regime, has recently been highlighted in the Protocol on Environmental Protection to the Antarctic Treaty. This Protocol is taking appropriate measures as an international environmental regime in regulating its member nations by enforcing principles in protecting Antarctic resources and environment, regulating member nations' Antarctic activities, establishing norms in the adoption of international and domestic laws, and devising regulations for deciding administrative actions through the member nations' collective decision-making procedures. h this context, this paper is to test a few questions; firstly, how the Antarctic Treaty System can be related with the role of international environmental regime; secondly, how the theories of international environmental regime, such as the hegemony theory, rational choice theory, and international morality theory, can be tested in the role of Antarctic Treaty System as an international environmental regime. Finally, this paper provides a solution for the future problems of the Antarctic Treaty System as an international environmental regime regarding the regime's principle (conflict between the environmental principle and the right of nation-state), norms and regulations (the conflict between the developed and underdeveloped nations in terms of the concept of 'common but differentiated environmental responsibility'), cooperation directions (the leadership problems between hegemonic nation and multilateral leading groups), and management methods (cooperation and arrangement problems among expert institutions, observer groups, and INGO).

• Journal of Acupuncture Research
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• 제24권5호
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• pp.33-41
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• 2007

Objectives : In oriental medicine, many researchers have studied Myofascial Pain Syndrome and Twelve-Meridian Muscle system in correlation with the orthodox form of muscular anatomy. In this study, the authors compared Myofascial Pain Syndrome with Twelve-Meridian Muscle system and interpreted Myofascial Pain Syndrome through Yook Kyoung theory to reveal the similarity between Myofascial Pain Syndrome and Twelve-Meridian Muscle system, as well as to suggest another useful therapeutics. Methods : The authors investigated several literatures related with Myofascial Pain Syndrome, Twelve-Meridian Muscle system and Yook Kyoung theory. Conclusions : 1. Myofascial Pain Syndrome and Twelve-Meridian Muscle system have many similar features in their theory, concept, physiological function, pathological symptom, therapeutic principal, etc., also have some different features. 2. Myofascial Pain Syndrome is thought to be induced by the unbalance between the upregulated-Kwelum energy and the downregulated-Soyang energy in a viewpoint of Yook Kyoung theory, therefore, it is requisite to control the unbalanced energy between Kwelum and Soyang.

• Journal of the Korean Society for Industrial and Applied Mathematics
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• 제5권2호
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• pp.149-156
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• 2001

Sufficient conditions for boundary controllability of semilinear systems in Banach spaces are established. The results are obtained by using the analytic semigroup theory and the Banach contraction principle. An example is provided to illustrate the theory.