• KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
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• v.3B no.1
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• pp.52-58
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• 2003

The application of a sliding mode control for improving the dynamic response of an induction motor based speed control system is presented in this paper and provides attractive features, such as fast response, good transient performance, and insensitivity to variations in plant parameters and external disturbance. However, chattering is a difficult problem for which the sliding mode control is a popular solution. This paper presents a new fuzzy-sliding mode controller for a sensorless vector-controlled induction motor servo system to practically eliminate the chattering problem for traction applications. A DSP based implementation of the speed control system is employed. Experimental results are presented using a propulsion system simulator. The performance of the drive is shown to be practically free from chattering.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.8 no.3
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• pp.59-65
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• 1999

To reduce the particulate matter and nitrogen oxides from diesel engine, many studies are proceeding and being accomplished practically. In this situation, LNG engine has important meaning as a clean fuel and alternative energy. In this reason, we try to understand the property of LNG fuel and predict the performance with using LNG engine simulation program and practical test. It could help to lead and apply practically LNG engine was studied in performance and other parameter related with engine performance and compared with current diesel engine. The simulation program was proved to be good in describing the experimental result. This means current heavy duty vehicle could be modified to LNG engine.

• Proceedings of the Korean Society of Marine Engineers Conference
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• 2006.06a
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• pp.135-136
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• 2006

There are several Disputes relating to the delimitation of maritime boundary and the policy of maritime jurisdiction of the states around the Korea Peninsula. These disputes are connected with the place of 'Tokdo' dominated practically by Korea, 'Senkaku islands' dominated practically by Japan, and 'Kurile islands' that is under disputing between Russia and Japan. North Korea has also the problem. The delimitation of Maritime Boundary among these States would be concluded in very near future. Therefore, we need to understand the maritime jurisdiction policy of these states. South Korea also has to set the policy.

• 전기의세계
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• v.27 no.5
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• pp.69-75
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• 1978

3 phase induction motor applied in the method of connecting it directly across the line needs large current when it starts. At that time, leakage magnetic pathes of interior of the motor are severely saturated and leakage reactances are decreased because of saturation. Consequently, increased current and raised powerfactor yield increase of starting torque. The author, noticing those phenomena, derived experimentally the raion of decreasing leakage reactance from the fact that when voltage applied to motor is increased under locked condition the magnitude of current and phase angle are varied, and determined tha equations of starting current and starting torque, considering the decrease of leakage reactance by the large starting current. The author calculated the characteristics of Current-Time and Speed-Time with the determined equation at specific load conditions, and compared the values obtained from above calculations with those from circle diagram's method and the practically recorded values at same load conditions. Therefore, the authos got a confidience that the results of the derived theory coincide with the practically measured values more well than circle diagram's results and circle diagram's equation should be modified in order to analize the starting status of a induction motor.

• Educational Technology International
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• v.8 no.1
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• pp.1-16
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• 2007

The general aim of this article is to explicate what can be researched in our field based on the new understanding on the ability of human visual intelligence. To follow this aim, three key discussions were followed. The first is to explain why the human visual intelligence research is so important in our field and how it was neglected. The basic orientations of the research questions used in its framing and in answering are reviewed. After reviewing traditional research orientations, as the second discussion, alternative, more useful perspective for thinking about human visual intelligence is suggested. And the possibility of contribution for the future research in general is discussed. In doing so, human visual intelligence was defined in rather practically oriented ways rather than theoretically oriented ones. More practical perspectives were suggested. The third discussion is to show how to use the alternative perspectives of human visual intelligence in the areas of educational technology research. It was hoped that the article lays out conceptual groundwork for generation of educational technology research frameworks which can be used for the research conduct, reproduction and sharing by adopting practically oriented views on human visual intelligence as a new territory of educational technology research.

• Journal for History of Mathematics
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• v.15 no.1
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• pp.109-114
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• 2002

By showing that several evidences from the history of mathematics do not follows the naturalness emerging in human being, the teaming principles of history of mathematics oriented teaming should be replaced both theoretically and practically by the principle of teaming from constructivism.

• Fiber Technology and Industry
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• v.1 no.1
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• pp.37-63
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• 1997

• Korean Journal of Acupuncture
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• v.23 no.2
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• pp.19-27
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• 2006

Objectives: Although Korean Acupuncture (KA) in Korean Medicine (KM) shares its origins with Traditional Chinese Medicine (TCM), it has made its own contribution to the field of acupuncture and general medicine. This study reviews characteristics of KA. Methods: Representative theories of KA were reviewed in light of a constitutionally individualized and practically integrated approach. Individualized approach in KA is based on constitutional energy traits recognized in Saam, Taegeuk, and Eight Constitution acupuncture theories. New practically integrated therapeutic modalities, such as herbal, and bee venom acupunctures, have also been developed in KA. Results: As a form of natural medicine, KA along with KM put emphasis on the vitality and self-correcting mechanism of an individual, which led to the refinement of constitutional approach. KA along with KM theories features a summarized understanding and practical application of integrated therapeutics, which produced creative development of new modalities. Conclusions: KA is expected to make significant contributions to the individualized and practical medicine, based on basic research and clinical trials.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 1992.03a
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• pp.1-10
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• 1992

Press is one of the most dangerous machine among the hazardous machinery. So, the apparatus of low cost automation is suggested to supply circumferential workpieces to press. And the apparatus is mocked up to apply practically.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2006.05a
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• pp.22-34
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• 2006

o GA-BF approach for improvement of learning and optimization in GA o GA-BF has better response on various test functions o Satisfactory PID controller tuning in AVR, motor vector control systems o Potentially useful in many practically important engineering optimization problems