• Industrial Engineering and Management Systems
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• 제7권2호
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• pp.113-125
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• 2008

This paper presents a model for designing cellular manufacturing systems (CMS) by integrating system cost, machine reliability, and preventive maintenance (PM) planning. In a CMS, a part is processed using alternative process routes, each consisting of a sequence of visits to machines. Thus, a level of 'system reliability' is associated with the machines along the process route assigned to a part type. Assuming machine reliabilities to follow the Weibull distribution, the model assigns the machines to cells, and selects, for each part type, a process route which maximizes the overall system reliability and minimizes the total costs of manufacturing operations, machine underutilization, and inter-cell material handling. The model also incorporates a reliability based PM plan and an algorithm to implement the plan. The algorithm determines effective PM intervals for the CMS machines based on a group maintenance policy and thus minimizes the maintenance costs subject to acceptable machine reliability thresholds. The model is a large mixed integer linear program, and is solved using LINGO. The results point out that integrating PM in the CMS design improves the overall system reliability markedly, and reduces the total costs significantly.

• Journal of Advanced Marine Engineering and Technology
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• 제32권2호
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• pp.336-342
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• 2008

Simple tuning methods of PI, PD and PID controller are proposed for an integrating process with time delay. This is based on matching the coefficients of corresponding powers of s in the numerator and that in the denominator of the closed-loop transfer function. For set-point tracking problem, the derived controller is found to be a PD controller which is shown by Lee's tuning rule based on minimizing the performance indexes (ISE, IAE, ITAE) using a real-coded genetic algorithm. A method can be also proposed PI, PID controllers according to tuning parameter lambda $({\lambda})$ similar to IMC method. Simulation example is given to illustrate the set-point tracking and disturbance rejection performance of the proposed method.

• 한국정밀공학회지
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• 제20권11호
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• pp.180-187
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• 2003

A CAD-based seamless design system for MEMS named DS/MEMS was developed which performs coupled-field analysis, optimal and robust design. DS/MEMS has been developed by means of integrating commercial codes and inhouse code-SolidWorks, FEMAP, ANSYS and CA/MEMS. This strategy results in versatility that means to include various analysis model, corresponding analyses and approximated design sensitivity analysis and user friendliness that design variables are taken to be selectable directly from a CAD model, that the problem is formulated under a window environment and that the manual job during optimization process is almost eliminated. DS/MEMS works on a parametric CAD platform, integrating CAD modeling, analysis, and optimization. Nonlinear programming algorithms, the Taguchi method, and response surface method are made available for optimization. One application problem is taken to illustrate the proposed methodology and show the feasibility of DS/MEMS as a practical tool.

• 한국안광학회지
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• 제2권1호
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• pp.91-95
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• 1997

균일하지 않게 코팅된 적분구의 효율성에 대한 일반적인 방정식이 제시되었다. 제시한 가정은 적분구 내부는 완전한 구형이고 모든 구내벽은 입사된 광선에 대해 완전하게 확산적으로 반사한다는 것이다. 제시한 방정식을 절대반사율 측정과 반구 반사율 측정이 혼합된 적분구에 대해서 기본적인 응용성을 시험하였다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년도 추계학술대회 논문집 전력기술부문
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• pp.375-377
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• 2006

This paper presents a method to calculate generation power for integrating Sihwa tidal power into power systems. The sea levels of 1 minute interval using cubic interpolation based on the forecasted levels of high and low water offered from Nori(National Oceanographic Research Institute) are calculated. If the sea level is greater than the lake level and the difference between sea level and lake level at high tide is over the default value, it begins to calculate the tidal power. It is seen that tidal power can supply power to demand side stably and economically from assessment of effect for integrating tidal power into power systems.

• JSTS:Journal of Semiconductor Technology and Science
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• 제14권2호
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• pp.227-234
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• 2014

A transceiver for a high-speed inductive-coupling link is proposed. The bi-phase modulation (BPM) signaling scheme is used due to its good noise immunity. The transmitter utilizes a complementary switching method to remove glitches in transmitted data. To increase the timing margin on the receiver side, an integrating receiver with a pre-charging equalizer is employed. The proposed transceiver was implemented via a 130-nm CMOS process. The measured timing window for a $10^{-12}$ bit error rate (BER) at 1.8 Gb/s was 0.33 UI.

• JSTS:Journal of Semiconductor Technology and Science
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• 제16권1호
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• pp.112-117
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• 2016

This paper presents a half-rate current-integrating DFE receiver with sub-unit interval (sub-UI) inter-symbol interference (ISI) cancellation. By having a single additional DFE tap in each data path, the proposed DFE receiver can minimize BER degradation due to input pattern dependency and feedback tap latency problems in conventional current-integrating DFE receivers. The proposed DFE receiver was designed and fabricated in a 45 nm CMOS process, whose measurement results indicated that the BER bathtub width is increased from 0.235 UI to 0.315 UI (34% improvement) at $10^{-12}$ BER level.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2006년도 춘계학술대회 논문집
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• pp.47-48
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• 2006

A roughness measuring system which comprises an integrating sphere and a stabilized laser has been fabricated with the aim of measuring the roughness correction value which is necessary in gauge block measurement by optical interferometry. To calibrate the system, a Newton's ring interferometer has been introduced. The method how to calibrate the roughness measurement system has been described.

• 인터넷정보학회논문지
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• 제8권2호
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• pp.137-146
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• 2007

본 논문에서는 지능형 로봇의 효율적인 제어를 위해 작업계획 생성기와 계획 실행기간의 연동방식을 제안한다. 이를 위해 본 논문에서는 먼저 작업계획 생성기와 실행기의 대표적인 유형과 연동방식들을 살펴본다. 그리고 BDI 구조의 계획 실행기에 주문형 작업계획 생성기를 연동하는 새로운 접근법을 소개하며, 이러한 연동방식에 기초한 지능형 로봇 제어구조를 설명한다. 또한 AIBO 로봇을 이용한 데모시스템의 구현을 통해 본 논문에서 제안한 이러한 연동방식과 제어구조의 유연성과 견고성을 분석해본다.

• 한국전자거래학회지
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• 제3권1호
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• pp.23-41
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• 1998

In a centralized database system, all system components reside at a single platform. In recent years there has been a rapid trend toward the integration of information systems over multiple sites that are interconnected via a communication network, and users' needs are changed to integration of multiple information sites. Multi database System is one of solutions for integrating distributed heterogeneous databases. However the problems in multi database system are restriction in distributed environment support, limitation in integrating heterogeneous media type data, static integration, and data-only of integration. In order to solve these problems, we propose a hybrid database integration model, HyDIM. HyDIM is used for the integrating legacy multimedia data, adopting CORBA, MDS, and mediator. We demonstrate a prototype system far PDM application domain.