• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1994년도 추계학술대회 논문집
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• pp.784-789
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• 1994

In the mobile robot research, monitoring the present status and self-navigating the robot in various environment are signifiant. This paper treates a navigation algorithm using a fuzzy logic and a sensor system - laser range finder. The navigation algorithm using a fuzzy logic is achieved by organizing the knoweledge base for self-navigation of mobile robot. In order that mobile robot is economically arrived the goal, the knowledge base is applied to acquire the informations of moving distance, direction, and velocity in every cycle time.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2004년도 Proceedings of ISRS 2004
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• pp.452-455
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• 2004

MSC (Multi-Spectral Camera) system is a remote sensing instrument to obtain high resolution ground image. EOS (Electro-Optic System) for MSC mainly consists of PMA (Primary Mirror Assembly), SMA (Secondary Mirror Assembly), HSTS (High Stability Telescope Structure) and DFPA (Detector Focal Plane Assembly). High performance of EOS makes it possible for MSC system to provide high resolution and high quality ground images. Temperature of the EOS needs to be controlled to be in a specific range in order not to have any thermal distortion which can cause performance degradation. It is controlled by full redundant CPU based electronics. The validity of thermistor readings can be checked because a few thermistors are installed on each control point on EOS. Various kinds of thermal control logics are used to prevent 'Single Point Failure'. Control logic has a few set of database in order not to be corrupted by SEU (Single Event Upset). Even though the thermal control logic is working automatically, it can also be monitored and controlled by ground-station operator. In this paper, various ways of thermal control logic for EOS in MSC will be presented, which include thermal control mode and logic, redundancy design and status monitoring and reporting scheme.

• 한국정보통신학회논문지
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• 제20권6호
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• pp.1203-1208
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• 2016

자신이 느끼는 것이나 보는 것, 경험하는 것을 언어로 표현하는 것이 서툰 아동들에게 있어 미술 활동은 감정을 표현할 수 있는 방법 중 하나이며 미술 치료를 위한 중요한 분석 대상이기도 하다. PC의 그림판 기능 등을 통한 디지털 그림이 일상화된 최근에는 기존의 색채학 이론과 미술 치료 이론이 접목되고 있으며 자동 분석 기능의 필요성이 대두되고 있다. 본 논문에서는 아동이 그린 그림에 대해 주조색 분석을 하고 ART2 알고리즘을 적용하여 색채 정보를 군집화한다. 군집화된 각각의 중심 벡터값을 기반으로 색채 빈도수를 소속 함수에 적용하여 퍼지화한다. 퍼지화된 중심 벡터 값을 퍼지 추론 규칙에 적용한 후에 비퍼지화를 수행한다. 비퍼지화된 값을 분석한 후에 주조색과 보조색을 결정하여 알슈울러와 해트윅의 단일 색채에 따른 심리 상태와 색상 조합의 심리상태와 비교한 결과, 거의 비슷한 결과가 도출되는 것을 확인하였다.

• 전력전자학회논문지
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• 제27권2호
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• pp.142-149
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• 2022

In increasing the safety and usage of lithium-ion battery packs, reducing the parameter deviation between cells, such as voltage and temperature within the battery pack, is important. In this study, we propose a screening method to reduce parameter deviation between cells in battery packs. Screening algorithms are constructed based on Fuzzy logic and quantitatively express the similarities between battery cells. Screening is applied by utilizing series resistance components after experiments of electrical characteristics that consider the operation status of battery packs. After screening, the standard deviation of series resistance components according to the similarity ranking is compared and analyzed, and their conformity are verified with the algorithm parameters.

• Industrial Engineering and Management Systems
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• 제7권1호
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• pp.99-107
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• 2008

This paper is concerned with scheduling in Flexible Manufacturing Systems (FMS) using a Fuzzy Logic (FL) approach. Four fuzzy input variables: machine allocated processing time, machine priority, machine available time and transportation priority are defined. The job priority is the output fuzzy variable, showing the priority status of a job to be selected for the next operation on a machine. The model will first select the machines and then assign operations based on a multi-criteria scheduling scheme. System/machine utilization, minimizing mean flow time and balancing machine usage will be covered. Experimental and comparative tests indicate the superiority of this fuzzy based scheduling model over the existing approaches.

• 대한기계학회논문집A
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• 제25권4호
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• pp.748-755
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• 2001

This paper concerns rotor vibration reduction using magnetic damper system. The fuzzy control logic is utilized to fulfill desired motion. The fuzzy system structure and membership function were first determined by simulation results. The researched control logic contains two fuzzy controller : reference position variation according to the rotor whirling status and error compensation algorithm to minimize the rotor vibration due to unbalance and unstable fluid film force. The Sugeno type output membership function was utilized by several trials and optimized membership function constants were selected from experiments. The experimental results show that the proposed method effectively control and reduce the rotor vibration with fluid film bearings.

• 한국과학교육학회지
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• 제7권2호
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• pp.1-14
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• 1987

To examine the effect of students' Cognitive level upon their achievement on Science. the students' cognitive levels were tested by using GALT(Group Assessment of Logical Thinking) and examined the Correlation between the cognitive level and achievement According to the results, most students were still in the conerete level. Only 60% of 9th grade students could handle the logic of displacement volume. In case of proportional logic and logic of probability, only 40% of 9th graders could handle them. Only 10% of the students could understand Correlational logic. Cognitive level and students achievement were estimated to be in a very closely related. Students who were in a high cognitive level showed better achievement scores on knowledge, comprehensive, inquiry, and application items than those who were in low cognitive level. Therefore, this study suggests that the content of the current middle school science should be revised in away to match the students' cognitive level.

• 한국자동차공학회논문집
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• 제21권6호
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• pp.40-48
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• 2013

Recently, many types of electric vehicles including a heavy duty vehicle have been developed and released because of the better fuel economy and less gas products. In this study, research about an electric bus which utilizes the wheel motor drive system was conducted. The wheel motor is a motor connected to the wheel directly only with a simple gear so that the developer can utilize the space efficiently and the whole system efficiency will be better because of simple structure. However, because it is different from former types of vehicles which use the differential gear, the development of the integrated control logic is required in order to meet the vehicle stability and driving performance. The developed control logic is composed with direct yaw moment control, regenerative braking control and slip control logics. It is compared to the control logics which does not consist of direct yaw moment control and slip control when the vehicle is exposed in tough situations. For the unification of the control logic, a few maps were developed and applied to determine the output torque of each motor according to the driving status. As a result, it is shown that the developed control logic is more safe and well follow the target speed than the other control logic applied simulations.

• International Journal of Fuzzy Logic and Intelligent Systems
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• 제3권1호
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• pp.112-120
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• 2003

This paper reports the development work carried out in respect of a proposed application of Neural Network approach for the Korean Next generation Reactor (KNGR) now referred as APR-1400. The emphasis is on establishing the methodology and the approach to be adopted towards realizing this application in the next generation reactors. Keeping in view the advantages and limitation of Artificial Neural Network Approach, the role of ANN has been limited to plant status or to be more precise plant transient monitoring. The simulation work carried out so far and the results obtained shows that artificial neural network approach caters to the requirements of plant status monitoring and qualifies to be incorporated as a part of proposed operator support systems of the referenced nuclear power plant.

• 한국항행학회논문지
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• 제24권4호
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• pp.285-290
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• 2020

본 논문에서는 텔레메트리 시스템에 적용하기 위한 PLL 기반의 시각동기 알고리즘을 제시하고 FPGA 로직을 구현하였다. 텔레메트리 시스템에서 대형 비행체의 경우 각각의 분산 획득 장치들을 통해 상태정보를 계측하여 실시간으로 비행 상태를 분석해야하므로 정밀도 향상을 위한 장치 및 시스템 간의 시각 동기의 중요성이 커지고 있다. 이 때문에 시각동기 기법으로 타 시각동기 방법보다 복잡도가 적고, 동기를 위한 추가적인 메시지 전송을 최소화하여 데이터 처리에 적은 시간이 소요되는 PLL 기반의 시각동기 알고리즘을 제안하였다. 타당성을 확인하기 위해 python 시뮬레이션을 수행하였으며 최종적으로 FPGA 내에 VHDL 로직을 구현하여 시각 동기 성능을 확인하였다.