• 전자공학회논문지CI
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• 제37권4호
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• pp.26-36
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• 2000

본 논문은 실시간 멀티프로세서 스케줄링 문제를 효과적으로 해결하는 신경망 알고리즘을 제안한다. 제안된 알고리즘은 대표적인 신경망 모델인 홉 필드 네트워크를 근간으로 태스크의 처리요구에 대해 지정된 시간이내에 처리할 수 있는 실시간 시스템을 신경망의 장점인 병렬처리가 가능하도록 구현하였다. 본 알고리즘의 성능을 비교하기 위하여 기존에 실시간 멀티프로세서 스케줄링을 위해 연구되는 EDA와 LLA의 두 알고리즘과 비교한다. 제안된 알고리즘은 VHDL을 이용하여 하드웨어로 설계한다.

• ETRI Journal
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• 제39권1호
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• pp.13-20
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• 2017

A method is proposed for scheduling sensor accesses to the shared network in a networked control system. The proposed method determines the access order in which the sensors are granted medium access through minimization of the state estimation error covariance. Solving the problem by evaluating the error covariance for each possible ordered set of sensors is not practical for large systems. Therefore, a convex optimization problem is proposed, which yields approximate yet acceptable results. A state estimator is designed for the augmented system resulting from the incorporation of the optimally chosen communication sequence in the plant dynamics. A car suspension system simulation is conducted to test the proposed method. The results show promising improvement in the state estimation performance by reducing the estimation error norm compared to round-robin scheduling.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2000년도 추계학술대회 논문집
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• pp.86-92
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• 2000

The crew operation scheduling problem is divided into duty generation and duty allocation. The railway crew roster scheduling(duty allocation) is developed monthly for each crew's office, considering the car types and crew's driving ability. However, it is very difficult to make schedules which assign monthly working hours to each crew evenly. The purpose of this thesis is to minimize the differences between each crew's total duty times and make a rostering table. To minimize the differences among monthly working hours of each crews are grouped according to car type and crew's driving ability and a rostering table which could be shared by the group members is developed. Our approach is to apply the techniques of Constraint Programming in order to solve such problems efficiently. This algorithm is suitable to solve optimization problems which involve many complicated constraints. And including the concept of cost, we suggested the model which enable to make the rostering table with a minimum personnel.

• Journal of Information Processing Systems
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• 제11권1호
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• pp.116-124
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• 2015

Smart grids propose new solutions for electricity consumers as a means to help them use energy in an efficient way. In this paper, we consider the demand-side management issue that exists for a group of consumers (houses) that are equipped with renewable energy (wind turbines) and storage units (battery), and we try to find the optimal scheduling for their home appliances, in order to reduce their electricity bills. Our simulation results prove the effectiveness of our approach, as they show a significant reduction in electricity costs when using renewable energy and battery storage.

• 한국컴퓨터정보학회논문지
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• 제7권2호
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• pp.40-45
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• 2002

본 연구는 상위수준합성에서의 데이터패스합성을 위한 스케쥴링을 다루었다. 특히, 연산자 할당에 필요한 상호연결선을 최적화하기 위한 스케쥴링 방법을 제안하였다. 또한 최적의 스케쥴링 결과를 얻기 위하여 ILP 수식을 이용하였고 본 연구의 효용성을 검증하기 위하여 5차 디지털 웨이브 필터를 대상으로 실험한 결과 기존의 결과 보다 나은 결과를 나타내었다.

• 한국콘텐츠학회논문지
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• 제6권11호
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• pp.276-284
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• 2006

WRR 기법은 대역을 보장해야 하는 스케줄링 기법으로 개발되었다. 최근에는 무선 통신 네트워크에서 다양한 대역이나 지연과 같은 차등화 된 서비스들을 제공 할 수 있도록 각 큐에 다른 가중치를 지정함으로써 여러 큐들을 직접적으로 관리할 수 있도록 하였다. 또한, WRR 알고리즘은 DBSW 구조에 의해 효율적으로 구현할 수 있다. 본 논문은 WRR 구현의 대표적인 방법인 DBSW 구조의 수학적 분석을 수행하고 분석결과와 시뮬레이션 결과를 비교 분석한다. 분석 데이터와 시뮬레이션 데이터는 수학적 분석이 타당하게 전개되었음을 입증하는 성능 결과를 보여주고 있다.

• ETRI Journal
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• 제32권3호
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• pp.422-429
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• 2010

We present guaranteed dynamic priority assignment schemes for multiple real-time tasks subject to (m, k)-firm deadlines. The proposed schemes have two scheduling objectives: providing a bounded probability of missing (m, k)-firm constraints and maximizing the probability of deadline satisfactions. The second scheduling objective is especially necessary in order to provide the best quality of service as well as to satisfy the minimum requirements expressed by (m, k)-firm deadlines. We analytically establish that the proposed schemes provide a guarantee on the bounded probability of missing (m, k)-firm constraints. Experimental studies validate our analytical results and confirm the effectiveness and superiority of the proposed schemes with regard to their scheduling objectives.

• 제어로봇시스템학회논문지
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• 제7권7호
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• pp.567-573
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• 2001

A real-time HVAC system is proposed which implements real-time control of thermal environment for virtual reality. It consists of a pair of hot and cold loops that serve as thermal reservoirs, and a mixing box to mix hot and cold air streams flowing if from loops. Their flow rates are controlled in real-time to meet a set temperature and flow rate. A cascade control algorithm along with gain scheduling is applied to the system and test results shows that the closed-loop response approached set values within 3 to 4 seconds.

• International journal of advanced smart convergence
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• 제7권3호
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• pp.92-100
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• 2018

In this paper, we propose a fault-tolerant scheduling scheme with energy efficiency for real-time periodic tasks on DVFS-enabled multicore processors. The scheme provides the tolerance of a permanent fault with the primary-backup task model. Also the scheme reduces the energy consumption of real-time tasks with the fully overlapped execution between each primary task and its backup task, whereas most of previous methods tried to minimize the overlapped execution between the two tasks. In order to the leakage energy loss of idle cores, the scheme activates a part of available cores with rarely used cores powered off. Evaluation results show that the proposed scheme saves up to 82% energy consumption of the previous method.

• 한국CDE학회논문집
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• 제19권4호
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• pp.402-409
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• 2014

Presented in this paper is a scheduling method for semiconductor backend process considering the backward pegging. It is known that the pegging for frontend is a process of labeling WIP lots for target order which is specified by due date, quantity, and product specifications including customer information. As a result, it gives the release plan to meet the out target considering current WIP. However, the semiconductor backend process includes the multichip package and test operation for the product bin portion. Therefore, backward pegging method for frontend can't give the release plan for backend process in semiconductor. In this paper, we suggest backward pegging method considering the characteristics of multichip package and test operation in backend process. And we describe the backward pegging problem using the examples.