• Educational Technology International
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• v.15 no.2
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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.

• Journal of the Korean Institute of Intelligent Systems
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• v.7 no.1
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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.

• Journal of Power System Engineering
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• v.7 no.1
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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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• v.4 no.2
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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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• v.16 no.2
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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.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.32 no.4A
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• pp.373-378
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• 2007

In this paper, the Game Theory based power control for OFDM system is studied, which has attained intensive interest as a core artificial intelligent technology for Cognitive Radio and its efficiency is evaluated using performance metrics such as system throughput and fairness. Utility Function for joint user centric and network centric power control is defined and simulation results show that game theory based power control is far better than closed loop power control. The contribution of this paper is to formalize the game theory based power control toward the Cognitive Radio that recognizes and adapts to the radio communication environments.

• The korean journal of orthodontics
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• v.26 no.3
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• pp.281-290
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• 1996

Determination of force system and prediction of side effects from unbent straight wire engaged in edgewise bracket is clinically very difficult because it is statically indeterminate system. This study is to develop a linear beam theory that explains the force system for straight wire engaged in edgewise bracket regardless of geometry(a/b), material, cross section of wire, and interbracket distance. 1. Formula for force system of bilateral fixed end beam was derived. 2. It is possible to calculate force system of each tooth engaged in continuous straight wire. 3. The possibility and location of permanent deformation can be predicted.

• Ocean and Polar Research
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• v.28 no.2
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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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• v.24 no.5
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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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• v.5 no.2
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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.