• 전기의세계
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• 제32권11호
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• pp.664-669
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• 1983

대규모 system을 취급하는 공학분야에 있어서 Matrix의 demension이 커짐에 따라 전산부담을 줄이기 위한 소요기억용량 절감 및 계산시간의 단축이 주된 관심사 중의 하나가 되어 왔다. LP(Linear Programming)기법 역시 대규모 선형 system에 적용될 경우 Basic Matrix 에 대한 dimensionality 문제를 포함하고 있으며 이에 대한 효과적인 해결방법으로 Bartels-Golub Decomposition 방법이 연구되어 있다. 이 방법은 Chan과 Yip등이 LSGA(Load Shedding and Generator Rescheduling) 문제에의 적용을 시도한 바 있으며, 일반적인 선형최적화 문제뿐만 아니라, dimensionality가 큰 Matrix의 Inverse 계산을 요하는 문제에 널리 적용될 수 있으므로 그 개요를 소개하고자 한다.

• 한국시뮬레이션학회논문지
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• 제18권3호
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• pp.147-154
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• 2009

본 연구에서는 자동차 도장 공장의 가장 큰 낭비 요소인 상도 공정의 세정 비용의 절감 및 환경 보호를 목적으로 상도 공정 이전의 각 컨베이어 연결점에서의 운영 알고리즘 변경시의 셋업 감소 효과를 시뮬레이션 모델링을 통해 분석하였다. 또한 본 연구의 동기가 된 도장 공정에서의 세정 비용 최소화 프로젝트 및 도장 공장 현황에 대해 설명하였다. 시뮬레이션 결과 컨베이어 연결점에서의 운영 알고리즘 개선시 현재 1.8대의 그룹화 효율을 2.5대 수준으로 향상시킬 수 있음을 알 수 있었다. 본 연구에서 적용한 접근법을 사용할 경우 그룹화 효율 향상에 별도 설비 투자가 필요 없고, CRS(Color Rescheduling Storage) 설치와 병행 적용하여 그룹화 효율을 더욱 향상시킬 수 있는 이점을 가지고 있다.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2002년도 ITC-CSCC -1
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• pp.212-215
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• 2002

In this paper, we present an intermediate representation CDFG(Control Data Flow Graph) and an efficient scheduling technique for low power circuit design. The proposed CDFG represents control flow, data dependency and such constraints as resource constraints and timing constraints. In the scheduling technique, the constraints are substituted by subgraphs, and then the number of subgraphs is minimized by using the inclusion and overlap relation efficiently. Also, iterative rescheduling process are performed in a minimum bound estimation, starting with the as soon as possible as scheduling result, so as to reduce the power consumption in low power design. The effectiveness of the proposed algorithm has been proven by the experiment with the benchmark examples.

• JSTS:Journal of Semiconductor Technology and Science
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• 제17권3호
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• pp.333-340
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• 2017

In this paper, we describe HW/SW co-optimizations for reconfigurable application specific instruction-set processors (ASIPs). Based on our previous very long instruction word (VLIW) ASIP, the proposed framework realizes various forward error-correction (FEC) algorithms for wireless communication systems. In order to enhance the energy efficiency, we newly introduce several design methodologies including high-radix algorithms, task-level out-of-order executions, and intensive resource allocations with loop-level rescheduling. The case study on the radix-4 turbo decoding shows that the proposed techniques improve the energy efficiency by 3.7 times compared to the previous architecture.

• 대한산업공학회지
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• 제21권3호
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• pp.409-428
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• 1995

Job shop scheduling with m different machines and n different jobs is a NP-hard problem of combinatorial optimization. The purpose of the paper is to develop the heuristic method using tabu search for job shop scheduling to minimize makespan or mean flowtime. To apply tabu search to job shop scheduling problem, in this paper we propose the several move methods that employ insert moves in order to generate the neighbor solutions, and present the efficient rescheduling procedure that yields active schedule for a changed operation sequence by a move of operations. We also discuss the tabu search techniques of diversifying the search of solution space as well as the simple tabu search. By experiments, we find the appropriate tabu list size and tabu attributes, and analyze the proposed tabu search techniques with respect to the quality of solutions and the efforts of computation. The experimental results show that the proposed tabu search techniques using long-term memory function have the ability to search a good solution, and are more efficient in the mean flowtime minimization problem than in the makespan minimization.

• 디지털융복합연구
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• 제7권2호
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• pp.35-41
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• 2009

The information technology, in the digital economy era, does a very important role not only for the country's administrative management innovation but also for the business and for the everyday life. Specifically, the e-business for the company or organization is defined as "using the Internet and IT, rescheduling of business process management activities to increase productivity and efficiency and to create new business opportunities." Thanks to the Korea's recent efforts, overall level of informatization and digitalization is able to receive high praise. But the e-business readiness (e-readiness) level is still expected a lot of room for improvement. In this paper, I try to analyze the informatization level of Korea's by the EIU's e-business readiness index and IT industry competitiveness index, to prepare a full-scale e-business era of global competitiveness through any preparation that could do to improve the situation from the analysis of statistical data.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2005년도 춘계학술대회 논문집
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• pp.153-156
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• 2005

Real-time monitoring and controlling manufacturing process is important because of the unexpected events. When unexpected event like mechanical trouble occurs, prior plan becomes unacceptable and a new schedule must be generated though manufacturing schedule is already decided for order. Regenerating the whole schedule, however, spends much time and cost. Thus automated system which monitors and controls manufacturing process is required. In this paper, we present a system which uses radio-frequency identification and computer vision system. The system collect real-time information about manufacturing conditions and generates new schedule quickly with those information.

• 산업공학
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• 제9권2호
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• pp.143-158
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• 1996

This paper deals with the development of a software module for production planning and scheduling activities of an actual die-production management system. Scheduling problems, such as master schedule and detailed schedule, are the focal point of the whole article and they are considered in terms of operation procedures. Schedule-explosion module and load levelling module are the essential components of schedule management. The scheduling module allocates the resources, determines the process priority and the planned start and completion dates of processes. Rescheduling can be done to manipulate unforeseen situations that schedule is delayed owing to inducing defectives, machine breakdowns and lumpy demands. This study indicates a practical model for the die-producation management and helps to apply it for jobs in the real situation.

• 한국조명전기설비학회지:조명전기설비
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• 제8권5호
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• pp.70-75
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• 1994

본 논문은 상정사고에 기인한 선로의 과부하 해소 대책을 수립함에 있어서 가능한 한 부하차단없이 발전력재배분만으로 과부하해소를 시도하는 새로운 앨고리즘을 제시한다. 신속한 발전력 변화분을 계산하기 위하여 선로 과부하량과 상태변수($\Delta$$\theta$) 및 상태변수($\Delta$$\theta$)와 발전력 사이의 선형적인 관계를 이용하여 우선 과부하선로 양단모선 전압의 위상각 변화분을 계산하고 이에 대한 발전력 변화분을 계산하였다. 이 때 모든 Jacobian요소를 계산하지 아니하고 과부하선로 양단 모선번호에 해당하는 2열의 요소중 발전기 모선(slack 모선 제외)번호에 해당하는 행의 요소만 구함으로써 최소한의 요소를 이용하여 신속하게 계산토록 하였다.

• 산업공학
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• 제7권2호
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• pp.107-120
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• 1994

This study introduces a scheduling policy to achieve unmanned operations in machining shops representing the feature of both FMS and machining centers. The proposed policy considers the practical constraints in the machining shops such as lot sizes, multiple pallets, and jig/fixtures. In addition, rescheduling to cope with extraordinary events(eg., arrival of high-priority jobs and breakdown of machines) is included. Basically, the scheduling policy consists of four procedures; (1) selection of a job according to dispatching rule, (2) selection of a machine, (3) assignment of jobs to a multiple pallet for the unmanned operation during a certain shift, and (4) prevention of unexpected machine idle caused by constraints on jig/fixture.