• Journal of Korean Neurosurgical Society
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• v.29 no.6
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• pp.800-804
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• 2000

Cerebral paragonimiasis is an important parasitic infestation found in Eastern Asia, West Africa, and Central/South America. It is frequently associated with abscess, granuloma or cystic lesions in chronic stage. Chronic symptoms include seizure, visual disturbance, movement and perception disorders, usually resulting from the spaceoccupying lesions. The authors report a case of chronic cerebral paragonimiasis combined with meningioma. A 69-year-old man presented with generalized seizure and impaired consciousness. CT scan and MR image of the brain revealed two intracranial lesions ; one was cerebral paragonimiasis in the left temporo-occipital lobe, and the other a huge falx meningioma. Two lesions were successfully removed in staged operations and the generalized seizure was controlled after removal of the cerebral paragonimiasis.

• Proceedings of the KIEE Conference
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• 2000.11d
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• pp.679-681
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• 2000

This thesis presents a analysis method of hybrid synthesis petri net for automated manufacturing systems in discrete event dynamic system. There are many errors that can happen to petri net modeling of complex systems because petri net modeling process has so many steps. A new matrix analysis method presented in this thesis can confirm the property of petri net such as boundedness, liveness and reversibility, modify errors which can be occurred in modeling.

• Proceedings of the KIEE Conference
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• 2000.11d
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• pp.615-617
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• 2000

Temporal Logic Frameworks is convenient to represent temporal relation. It is useful to represent a dynamic properties of Discrete Event Dynamic Systems. Also, it is convenient to express a current and next state of event using logical representation. Because the teachability tree of the Temporal Logic Frameworks is very complexity it is difficult to understand. In this paper, we defined some rules to represent Temporal Logic Frameworks by Petri Net and proposed am method of the representation of them Petri Net for the Temporal Logic Frameworks. An example are used to demonstrate the feasibility of this method.

• Proceedings of the KIEE Conference
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• 2001.11c
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• pp.212-214
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• 2001

Siphons and traps are special structures of Petri nets with closely related to liveness for the deadlock analysis of Discrete Event Dynamic Systems. It can analysis the liveness of Petri nets using the siphon and trap without to check reachability.[1] Deadlock analysis approach we proposed is based on the notion of potential deadlock which are siphons that eventually become empty. And in this paper, we proposed a initial marking method by siphon to avoid and to prevent deadlock. It is shown that our approach is more efficient than classical state enumeration approach.

• Proceedings of the KIEE Conference
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• 1999.07f
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• pp.2632-2634
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• 1999

In this paper, we analyze the characteristics of Motor Noise according to PWM method, especially in the case of 2-phase conduction method. There are two types of PWM methods used usually. One is Lower-PWM and the other is Upper&Lower PWM. Because there is a difference between freewheeling path of both methods, Current profiles of two methods are different. This makes the difference of Torque Ripple and so difference of Noise Performance. In this paper, the path will be analyzed and the comparison of Noise performance of two types of PWM methods will be showed by experiment results.

• Proceedings of the Korean Environmental Sciences Society Conference
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• 2006.05a
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• pp.414-416
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• 2006

도축 부산물인 우모는 높은 영양적 가치를 가짐에도 불구하고 현재 사용하는 물리화학적 처리법의 여러 단점으로 효율적으로 이용되지 못하고 있어서 경제적 방법인 생물 공학적 처리에 대한 연구의 필요성이 커지고 있다. 본 연구에서는 그러한 방법 중 대표적인 방법으로 미생물이 생산하는 keratinase 를 이용한 생분해에 대해 연구를 하기 위해 퇴비화 볏짚에서 keratinolytic protease 생성능이 우수한 균주를 분리하였고 생화학적 동정법과 16S rDNA를 이용한 동정결과 B. pumilus로 동정되었다 본 실험에서 분리된 B. pumilus는 기존에 활발히 연구되어 있지 않는 균주로서 native feather 분해도가 기존에 알려진 Bacillus 속들이 3일 정도에서 분해가 완료되는 것과는 달리 36시간$\sim$48시간 내에 깃대까지 완전히 분해하였다.

• Journal of Korea Foundry Society
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• v.29 no.2
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• pp.59-63
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• 2009

Effects of Ti on damping capacity and mechanical properties are investigated in hot rolled Fe-17%Mn alloy. The existing damping alloy with Fe-Mn binary system was limited the use by high production cost, however in case of using scrap iron instead of pure iron although the content of carbon is higher it is possible to be applied wider field especially construction items because the production cost is lower. However, the excellent specific damping capacity is dropped due to the high content of carbon, we developed advanced type of damping alloy included Ti. TiC is formed with added Ti and it holds the specific damping capacity similar to existing damping alloy. The effect of Ti on damping capacity is found to be beneficial in carbon-containing alloy, which is attributed to the depletion of carbon solute due to the formation of TiC.

• Journal of Institute of Control, Robotics and Systems
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• v.8 no.6
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• pp.439-444
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• 2002

In this paper, a new model reduction method is proposed to obtain a reduced order model in the frequency domain. The method is developed based on the second-order plus dead time modeling technique. The initial value of the reduced model parameters can be obtained using this method coinciding four point(0, -$\pi$/2, -$\pi$, -3$\pi$/2) on the Nyquist curve. The optimal parameters of the reduced model is obtained through calculation procedure with three steps. It is shown that Nyquist curves and unit step responses of the reduced models of numerical examples closely agree with those of original models.

• Proceedings of the KSR Conference
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• 2007.11a
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• pp.1599-1604
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• 2007

LIMs propelling the MAGLEV which has been developed in Korea have 3-series and 2-parallel connection, so that 6 LIMs per one vehicle are fed by one inverter. Thrust performance of the parallel-operated LIMs can be different from each other because of variant magnetic air gaps and electrical impedance. The thrust difference between the parallel LIMs cause a twist force on the vehicle. This paper proposes an algorithm to measure thrust of the parallel-operated LIMs. The method uses a digital signal processor(TMS320F2812), voltage and current sensors. As a result, thrust, flux and currents of the parallel-operated small LIMs which are manufactured in our laboratory are monitored by the developed measurement system.

• Proceedings of the KSR Conference
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• 2007.11a
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• pp.1460-1465
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• 2007

In this paper, the conventional linear induction motor(LIM) used in propelling the MAGLEV in Korea is redesigned in order to reduce its weight. The specifications of the newly designed model for base speed, acceleration, rated thrust and maximum output is respectively 45km/h, 4.0km/h/sec, 5,200[N] and 65 [kW]. Weight reduction effect of the LIM according to the change of pole number from 8 to 6 is shown. Equivalent circuit analysis considering end effect and finite element method are used for the analysis of the redesigned model. Finally the weight reduction ratio of the newly designed LIM to the conventional model, thrust, attraction force, line current, temperature rise, flux density distribution are presented.