• 대한기계학회:학술대회논문집
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• 대한기계학회 2000년도 춘계학술대회논문집A
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• pp.797-802
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• 2000

Flow shop scheduling problem involves processing several jobs on common facilities where a setup time Is incurred whenever there is a switch of jobs. Practical aspect of scheduling focuses on finding a near-optimum solution within a feasible time rather than striving for a global optimum. In this paper, a hybrid meta-heuristic method called tabu-genetic algorithm(TGA) is suggested, which combines the genetic algorithm(GA) with tabu list. The experiment shows that the proposed TGA can reach the optimum solution with higher probability than GA or SA(Simulated Annealing) in less time than TS(Tabu Search). It also shows that consideration of setup time becomes more important as the ratio of setup time to processing time increases.

• 한국정보처리학회논문지
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• 제7권4호
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• pp.1201-1210
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• 2000

In order to tolerate faults which may occur during the execution of distributed tasks in high-performance parallel computer systems, tasks are duplicated on different processors. In this paper, by utilizing the task duplication based scheduling algorithm, a new task scheduling algorithm which duplicates each task on more than two different processors with the minimum schedule length is presented, and the number of processors required for the duplication is analyzed with the ratio of communication cost to computation time and the workload of the system. A simulation with various task graphs reveals that the number of processors required for the full-duplex fault-tolerant task scheduling with the obtainable minimum schedule length increases about 30% to 75% when compared with that of the task duplication based scheduling algorithm.

• 한국통신학회논문지
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• 제34권6B호
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• pp.641-647
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• 2009

본 논문은 임베디드 시스템에서 불필요한 전력 소모를 감소하기 위해 개선된 예측 동적 전력 관리 구조와 태스크 스케줄링 알고리듬을 제안한다. 제안된 알고리듬은 불필요한 전력 소모를 최소화하기 위해 미리 스케줄링을 한다. 제안된 예측 동적 전력 관리는 수행 오버 헤드를 경감하기 위해서 스케줄링 라이브러리를 제공한다. 실험 결과 제안된 알고리듬은 동적 전력 관리를 적용한 LLF 알고리듬과 비교하여 평균 22.3% 전력 소모 감소를 보인다.

• 전기학회논문지P
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• 제59권3호
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• pp.245-252
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• 2010

This paper proposes a constrained multi-area dispatch scheduling algorithm applicable to interconnected power system operations. The dispatch scheduling formulated as an MIP problem can be efficiently computed by GBD algorithm. GBD guarantees adequate computation speed and solution convergence by reducing the dimension of the dispatch scheduling problem. In addition, the regional decomposition technique based on ADM is introduced to obtain efficient inter-temporal OPF solution. It can find the most economic dispatch schedule incorporating power transactions without each regional utility's private information open.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2002년도 하계종합학술대회 논문집(1)
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• pp.81-84
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• 2002

The WRR scheduling algorithm is widely used in ATM networks due to its simplicity and the low cost of hardware implementation. It guarantees minimum cell rate according to the weight of each queue. The fairness is a important factor for ABR service. That is, Scheduling algorithm allocates network resources fairly to each VC. In this paper, we propose a scheduling algorithm for satisfying the two fairness criteria, MCR plus equal share and Maximum of MCR or Max-Min share, among the six criteria defined by ATM Forum TM 4.1 specification. The WRR, Nabeshima et al, and the proposed scheduling algorithms are compared with respect to fairness and convergence time throughout experimental simulation.

• Journal of Communications and Networks
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• 제6권2호
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• pp.147-155
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• 2004

In this paper, we propose an efficient sequencing technique, namely minimum Row time scheduling (MFTS), to manage variable-Iength message transmissions for single-hop passive starcoupled WDM optical networks. By considering not only the message length but also the state of the receivers and the tuning latency, the proposed protocol can reduce the average delay of the network greatly. This paper also introduces a new channel assignment technique latency minimizing scheduling (LMS), which aims to reduce the scheduling latency. We evaluate the proposed algorithm, using extensive discrete-event simulations, by comparing its performance with shortest job first (SJF) algorithm. We find that significant improvement in average delay could be achieved by MFTS algorithm. By combining the proposed message sequencing technique with the channel selection technique, the performance of the optical network could be further improved.

• 한국경영과학회:학술대회논문집
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• 한국경영과학회 2000년도 추계학술대회 및 정기총회
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• pp.149-152
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• 2000

The chartered bus scheduling is to determine the allocation of buses to customer service requests. For the scheduling, we first represent the scheduling problem using a graph and develop a mathematical model. Second, we develop an algorithm for the scheduling problem including heuristic methods. We tested the performance of the algorithm on instances with real data. As a result, the total empty load driving time is reduced over 10% comparing with that of current practice at the company

• 한국통신학회논문지
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• 제25권10B호
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• pp.1665-1674
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• 2000

This paper treats the interworking of LAN-based networks like TCP over the ATM protocol stack in an ATM multicast session. Multicast connection will cause CIP since multicast group members form a connection tree by some tree methods and share the connected tree. The paper solve the CIP problem through a block-by-block transmission using ABT/IT method. ABT/IT RM cell is modified and block scheduling algorithm considering the traffic types is applied to each ATM switch using the enhanced RM cell. Block scheduling algorithm will avoid the indiscriminate discard of UBR traffic when congestion occurs and it can provide an efficient and fair service. The paper builds a block scheduler system and suggests the block scheduling algorithm for a multicast session in an ATM switch. UBR traffics arriving at the switch trough each VC is classified by the traffic type and stored at class buffer and thereafter indisciminately transmitted. When block scheduling algorithm is applied it will improve the UBR traffic performance such as end-to-end delay cell block loss ration etc. This paper evaluated the performance of block scheduling algorithm through the simulation using the C language and data structure.

• 대한조선학회논문집
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• 제45권6호
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• pp.646-655
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• 2008

A main issue about production management of shipyards is to efficiently manage the work in process and logistics. However, so far the management of a transporter for moving building blocks has not been efficiently performed. To solve the issues, optimal block transporting scheduling system is developed for minimizing of the travel distance without overload of a transporter. To implement the developed system, a hybrid optimization algorithm for an optimal block transportation scheduling is proposed by combining the genetic algorithm and the ant algorithm. Finally, to evaluate the applicability of the developed system, it is applied to a block transportation scheduling problem of shipyards. The result shows that the developed system can generate the optimal block transportation scheduling of a transporter which minimizes the travel distance without overload of the transporter.

• 대한안전경영과학회지
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• 제25권4호
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• pp.131-140
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• 2023

This paper proposes an algorithm for the Unrelated Parallel Machine Scheduling Problem(UPMSP) without setup times, aiming to minimize total tardiness. As an NP-hard problem, the UPMSP is hard to get an optimal solution. Consequently, practical scenarios are solved by relying on operator's experiences or simple heuristic approaches. The proposed algorithm has adapted two methods: a policy network method, based on Transformer to compute the correlation between individual jobs and machines, and another method to train the network with a reinforcement learning algorithm based on the REINFORCE with Baseline algorithm. The proposed algorithm was evaluated on randomly generated problems and the results were compared with those obtained using CPLEX, as well as three scheduling algorithms. This paper confirms that the proposed algorithm outperforms the comparison algorithms, as evidenced by the test results.