• Journal of the Korean Institute of Telematics and Electronics B
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• v.33B no.8
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• pp.124-133
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• 1996

This paper presents the implementation of variable structure control system for a linear or nonlinear system using neural networks. The overall control system consists of neural network controller and a reaching mode controller. While the former approximates the equivalent control input on the sliding surface, the latter is used to bring the entire system trajectories toward the sliding surface. No supervised learning procedures are needed and the weights of the neural network are tuned on-line automatically. The neural netowrk-based variable structure control system is applied to a nonlinare unstable inverted pendulum system through computer simulations, and implemented using a microcomputer (80486-50MHz) and applied to the DC servomotor position control system. Simulation and experimental results show the expected approximation sliding property is occurred. The proposed controller is compared with a PID controller and shows better performance than the PID controller in abrupt plant parameter change.

• Proceedings of the Korean Institute of Resources Recycling Conference
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• 2006.09a
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• pp.3-12
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• 2006

The main feature of these total technologies is that we can constitute the optimum treatment scheme fitting to the property of wastes, amount of wastes and energy requirement. For high moisture content wastes or biomass resources, high pressure steam process (MMCS) for crush, dry and deodorize wastes to produce high quality fertilizer of fuel is most appropriate. For dry or semi-dry solid wastes, the STAR-MEET system can be applied to produce low-BTU gases for power generation using duel fueled diesel engines of Stirling engines, and the REPRES and HyPR-MEET systems can be applied to produce hydrogen rich medium-BTU gas. For waste plastics and oils, liquefaction technology is best fit to produce light oil or kerosene equivalent fuel oils. These total technologies are completely different from the existent waste treatment technologies based on land-filling or incineration, and are expected to disseminate all over the world in the near future.

• Proceedings of the KIEE Conference
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• 2000.07d
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• pp.2280-2282
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• 2000

This paper presents a simple and new digital redesign algorithm for fussy-model-based controllers. In the first stage, a continuous-time TS fuzzy model is constructed for a given continuous-time nonlinear system and a corresponding continuous-time fuzzy-model-based controller is established based on the existing controller synthesis algorithms. In the second stage, the continuous-time fuzzy-model-based controller is converted to equivalent discrete-time fuzzy-model-based controller, aiming at maintaining the property of the analogue controlled system, which are called intelligent digital redesign. Finally, the proposed method is applied to the digital control of inverted pendulum system to shows the effectiveness and the feasibility of the method.

• Journal of applied mathematics & informatics
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• v.9 no.1
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• pp.135-150
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• 2002

The present paper discusses non-deterministic finite Rabin-scott's automate. The majority of works recently dealing with this subject were, in fact, concerned only with properties of a canonical term automata or of some objects equivalent to it. This article continues the series of works in which the authors state a different point of view, describing the finite automata as just another invariant of the given regular language called basis finite automaton. In this article the authors argue on some new properties for the basis finite automaton. One of them is included into basis automaton's table of binary relations. It is stated that this table can not contain either identical strings or identical columns. Another property depicts a possibility to obtain any finite automaton for a given regular language by the process of duplicating or combining some of its states.

• Research in Mathematical Education
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• v.18 no.2
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• pp.149-170
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• 2014

The Vietnamese language has a specific property related to the zero in the name-number system. This study was conducted to examine the impact of linguistic differences and of the zero's position in a number on a transcoding task (verbal number into Arabic number). Vietnamese children and French-speaking Belgian children, from grades 3 to 6, participated in the study. The success rate and the type of errors they made varied, depending on their grade and language. At Grade 4, Vietnamese children showed performances equivalent to Grade 6 Belgian children. Our results confirmed the support provided by language to the understanding and performances in a transcoding task. Results also showed that a syntactic zero is easier to manipulate than a lexical zero for Vietnamese children. The relative influence of language and the source of errors are discussed.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.54 no.4
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• pp.174-180
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• 2005

Linear pulse motor (LPM) has the vibration during the operation because of magnetic characteristic which is caused by the mechanical configuration and the electromagnetic property. This paper proposes the calculation of thrust on the base of magnetic equivalent circuit for the purpose of the vibration minimization of LPM. The permeance of LPM is calculated and simulated from the construction tooth. The thrust is compared with the analytical method, the 3D finite element method (FEM) and the experimental values. The vibration of LPM is measured and estimated to select the input current wave for an optimal operation condition.

• The Transactions of the Korean Institute of Electrical Engineers D
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• v.50 no.10
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• pp.457-463
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• 2001

This paper presents a simple and new digital redesign algorithm for fuzzy-model-based controllers. In the first stage, a continuous-time TS fuzzy model is constructed for a given continuous-time nonlinear system and a corresponding continuous-time fuzzy-model-based controller is established based on the existing controller synthesis algorithms. In the second stage, the continuous-time fuzzy-model-based controller is converted to equivalent discrete-time fuzzy-model-based controller, aiming at maintaining the property of the analogue controlled system, which are called intelligent digital redesign. Finally, the proposed method is applied to the digital control of inverted pendulum system to shows the effectiveness and the effectiveness and the feasibility of the method.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.50 no.6
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• pp.276-280
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• 2001

This paper presents the result of a study on the distribution characteristics of salt contaminants in the west coast region, from Inchon to Yearsoo, of South Korea. To evaluate the distribution characteristics of salt contaminants, we had measured the equivalent salt deposit density(ESDD) with brush wiping method for thirteen month(from May 1999 to June 2000). Under the consideration on the measuring interval and method, normalization method was applied for the ESDD data. Besides the measurement, the chemical analysis (chromatography) was carried to investigate the relationship, between the electrical property and the amount of specific ingredient, such as sodium, magnesium and chloride. From the result, we could get the representative value of contamination for each site and distribution characteristics of salt contaminants with the distance from sea in the west coast.

• Proceeding of EDISON Challenge
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• 2016.03a
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• pp.190-194
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• 2016

자연에서 안정적이고 경제성이 높은 구조로 벌집 구조가 많이 언급이 된다. 이러한 벌집 구조의 특징으로 인해 많은 공학자들이 그 구조를 모방하여 적용하고 있다. 벌집 구조에도 다양한 종류가 존재하지만 그 중 음의 푸아송 비(Poisson's ratio)를 갖는 Chiral Honeycomb 구조가 많이 연구되고 있다. 푸아송 비는 물질이나 구조의 고유한 물성치로 종, 횡 방향의 변형율로 나타내며 이 값으로 외부 조건으로부터의 변형을 예측 할 수 있게 된다. 흔히 푸아송 비는 양의 값을 가지지만 Chiral Honeycomb 구조는 음의 푸아송 비를 가져 기존의 구조와는 다른 기계적 성질을 가지게 된다. 이 논문에서는 Chiral Honeycomb 구조 중에서도 4개의 관절(ligament)를 가지는 Tetra Chiral Honeycomb 구조에 대해 EDISON용 CASADsovler 프로그램을 통해 유한 요소 해석을 수행하여 등가 물성치를 구해 보았으며 기존 실험의 값들과 비교를 통해 해석을 위해 필요한 적절한 대표 체적에 대해 확인해 보았다.

• Proceedings of the Korean Society of Disaster Information Conference
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• 2017.11a
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• pp.251-252
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• 2017

현재 우리나라는 자동차 수의 폭발적인 증가에도 불구하고 전체적인 교통사고 건수는 감소되는 추세를 보이고 있는데 반해 고속도로에서 발생하는 사고는 증가 추세를 보이고 있다. 따라서 고속도로의 사고 특성을 파악하여 사고를 감소시키기 위한 다양한 연구가 많이 진행되고 있다. 하지만 다양한 사고 유발요인들과 사고 데이터 제공의 한계로 인해 고속도로 교통사고의 특성에 대해 명확히 규명한 연구는 부족한 실정이다. 본 연구에서는 전국고속도로 3개년도(2013~2015)의 자료를 활용하여 전국 고속도로 교통사고의 특성을 파악하고 사고건당 EPDO(Equivalent Property Damage Only)를 계산하여 EPDO 값과 사고원인별, 도로 기하구조별, 기상조건, 운전자 성별, 나이대별 등 여러 사고 조건과의 상관관계를 회귀분석을 통해 분석하였다.