• 한국지능시스템학회논문지
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• 제16권2호
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• pp.191-197
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• 2006

본 논문에서는 원저 증기발생기 수위제어계통을 위한 고장검출 시스템을 설계한다. 이를 위하여 증기발생기 수위제어계통의 비선형 동적방정식을 미지의 매개변수를 갖는 T-S 퍼지시스템으로 모델링하고 좌 소인수 분해를 이용하여 오차발생기를 설계한다. 고장검출의 성능을 향상시키기 위하여 고장검출 필터의 설계법을 제안한다. 제시한 방법의 효용성을 컴퓨터 모의실험을 통하여 입증한다.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2006년도 하계종합학술대회
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• pp.965-966
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• 2006

As billion transistors system-on-chip (SoC) design becomes a reality, the productivity gap between rapidly increasing design complexity and designer productivity lagging behind is becoming a more serious problem to be solved. To reduce the gap, we present a system that generates executable transaction level models automatically. It speed up the SoC design space exploration process at various abstraction levels.

• 품질경영학회지
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• 제32권2호
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• pp.168-190
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• 2004

In these days of world-wide business environment, the characteristics of quality management are variety, specialty, decentralization, totality, etc. Thus nowadays quality management is demanded to incorporate these new concepts. We propose a web-bused distributed expert system for this purpose. The system consists of four expert systems for design of experiment, acceptance inspection, statistical process control and reliability management corresponding to design quality, incoming-material quality, manufacturing quality and usability quality, respectively, throughout the total product life cycle. Each distributed expert system at the horizontal level in the hierarchy carries out its own quality jobs independently. At the lower level in the hierarchy there is an expert system for measurement analysis to provide reliable data, and at the upper level, an expert system for total quality management to coordinate, integrate and make final decisions. A prototype has been developed and its application is presented.

• 대한전자공학회논문지SD
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• 제45권4호
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• pp.78-85
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• 2008

네트워크 SoC 칩을 대상으로 SystemC를 이용한 High-level 설계 방법을 연구하였다. 실제 Verilog RTL 모델과 비교하여 깊이있는 Architecture 구조탐색과 정확한 SystemC 모델 cycle 검증을 토대로 하여 High-level 설계를 강조할 것이다. 대다수 High-level 설계와 접근방법과 다르게, SystemC 모델과 Verilog RTL 모델의 성능을 비교해 보고, SystemC-based platform을 검증하기 위해 On-chip test board 측정 데이터를 이용하였다. 이 논문에서는 High-level 설계기법이 RTL 모델과 같은 정확성을 얻을 수 있을 뿐만 아니라, RTL 모델보다 100배 이상 빠른 시뮬레이션 속도를 달성할 수 있음을 보여 주었다. 그리고, 아키텍처 구조탐색을 통해서 시스템 성능하락의 원인을 파악하고, 대안을 찾아보았다.

• 한국실내디자인학회논문집
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• 제15권5호
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• pp.255-264
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• 2006

This study started from the premise that the satisfaction of visitors in large-scaled design-related fair has co-relation with the environmental and contextual factors such as contents, lighting, the number and location of rest area, crowdedness, ventilation and circulation. The research was made in Seoul Living Design Fair 2005. 102 samples from 132 who answered to the questionnaire with likert-scaled and open questions were selected for the data, which were statistically analyzed through SPSS 12.0 program to explore the co-relation between the environmental factors and the satisfaction level of visitors. The findings showed that overall satisfaction level was in the middle of the scale, which means satisfied nor unsatisfied. The visitors showed relatively high satisfaction in the two factors-the contents of the fair and lighting system compared to the other factors such as the number and location of rest area, sign system, ventilation crowdedness and circulation. Even though the visitors had difficulties in circulation and showed various types in circulation, it did not seem to have a significant influence on the overall satisfaction level because it might be offset by the contents of the fair. Also, the visitors showed similar satisfaction level regardless of the type of circulation. It can be concluded that the main factors mentioned above should be considered to achieve higher satisfaction level and provide better environment in the large-scaled fair.

• 대한기계학회논문집A
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• 제30권9호
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• pp.1070-1077
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• 2006

In the present study, sizing and shape optimizations are performed based on the reduced system of large-scaled problem. In the analysis part to achieve efficiency and reliability of computation, two-level condensation scheme is applied. In the construction of reduced system of large scaled problems, it is much more efficient to use sub-domain method. Thus, in the present paper, two-level reduction method combined with sub-domain method is employed. Once the reduced system is constructed, it is straightforward to obtain design sensitivities from the analysis results of the reduced system We use semi-analytic method to obtain design sensitivities. Performance of the efficiency and reliability of the present reduction method in the structural optimization problem is demonstrated through the numerical examples. The present framework of reduction method should serve as a fast and reliable design tool in analysis and design of large-scaled dynamic problems.

• 대한산업공학회지
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• 제29권3호
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• pp.230-238
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• 2003

The configuration design of a mechanical product can be efficiently performed when it is based on the functional modeling. There are methodologies, which decompose function from the abstract level to the concrete level and match the functions to physical parts. But it is difficult to carry out an innovative design when the function is matched only to a pre-detined part. This paper describes the configuration design process of a mechanical product with a design expert system, which uses function taxonomy and TRIZ theory. The expert system can propose a functional modeling of a new part. which is not in the existing parts list. The abstraction levels of design knowledge are introduced, which describe the operation of mechanical product in the levels of abstraction. This is the theoretical background of using knowledge of function and TRIZ for configuration design. The expert system is adequate to control this design knowledge. which expresses knowledge of functional modeling, mapping rules between functions and parts, selection of parts, and TRIZ theory. The hierarchy of functions and machine parts are properly expressed by classes and objects in the expert system. A design expert system has been implemented for the configuration design of a train bogie, and a new brake system of the bogie is introduced with the aid of TRIZ's 30 function groups.

• 유체기계공업학회:학술대회논문집
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• 유체기계공업학회 1998년도 유체기계 연구개발 발표회 논문집
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• pp.159-165
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• 1998

Bearing design of turbo type geared centrifugal air compressor for low vibration level has been studied. The Transfer Matrix Method was used in this paper to analyze the air-compressor consisting of impellers, multi-stage geared rotors, and oil-film hearings. We have to consider this air-compressor as multi-geared rotating system, because characteristics of rotor-bearing system are different from conventional characteristics of non-rotating system. From the view point of Rotordynamics, the stiffness and damping coefficient of oil-film bearing in case of compressor system are more sensitive than other design parameters such as shaft length, shaft diameter and the weight of impellers, etc. Therefore, the stiffness and damping coefficients on each bearing were considered as design parameters. As the result of this study, turbo type air compressor with low vibration level can be achieved.

• 전자공학회논문지C
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• 제34C권3호
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• pp.11-22
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• 1997

This paper presents the design and implementation of an efficient algorithm for detecting untestable paths in multi-level circuits. Transforming multi-level circuit into a multiplexor-based one through BDD(binary decision diagram)construction, the proposed algorithm detects untestable paths in the transformed circuits. By constructing ENF (equivalent normal form) only for reconvergent paths, the proposed system detects and removes untestable paths efficiently in terms of the run-time and memory usage. Experimental results for MCNC/ISCAS benchmark circuits show that the system efficiently detects and removes untestable paths. The run-time and memory usage have been reduced by 37.7% and 60/9%, respectively, comapred to the previous methods.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2001년도 제14회 신호처리 합동 학술대회 논문집
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• pp.963-966
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• 2001

The wideband DS-CDMA (W-CDMA) system is one of the candidates for the next generation mobile communication system known as IMT-2000. The important concept of W-CDMA is the introduction of intercell asynchronous operation. In this paper, we design and analyze the system level simulator for the International Mobile Tele communication - 2000 (IMT-2000) 3-rd generation partnership project (3GPP) system. We confirm how the simulator works by BER over different Eb/NO. This study will be expected to use as reference data in the development of asynchronous IMT-2000. In this paper, we analyze a physical layer of W-CDMA system and design a transmitter and receiver by using ADS (Advanced Design System). Also, we simulated a link level performance in Rayleigh fading channel environment. This study will be useful in the analysis and design of W-CDMA system.