• 한국항해학회지
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• 제14권1호
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• pp.21-38
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• 1990

This paper discusses the various modes of operations of cargo ships which are liner operations, tramp shipping and industrial operations, and mathematical programming, simulation , and heuristic method that can be used to solve ships routing and scheduling problems for each of these operations. In particular, this paper put emphasis on a crude oil tanker scheduling problem. The problem is to achieve an optimal sequence of cargoes or an optimal schedule for each ship in a given fleet during a given period. Each cargo is characterized by its type, size, loading and discharging ports, loading and discharging dates, cost, and revenue. Our approach is to enumerate all feasible candidate schedate schedules for each ship, where a candidate schedule specifies a set of cargoes that can be feasibly carried by a ship within the planning horizon , together with loading and discharging dates for each cargo in the set. Provided that candidate schedules have been generated for each ship, the problem of choosing from these an optimal schedule for each ship is formulated as a set partitioning problem, a set packing problem, and a integer generalized network problem respectively. We write the PASCAL programs for schedule generator and apply our approach to the crude oil tanker scheduling problem similar to a realistic system.

• 융합신호처리학회논문지
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• 제6권1호
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• pp.39-44
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• 2005

스케줄링은 CDFG 내의 각 연산에 우선순위 관계를 유지하면서 연산이 수행될 제어스텝을 할당하는 과정으로 합성된 하드웨어의 성능에 직접적인 영향을 미치는 중요한 단계이다. 본 논문에서는 자원제한 스케줄링 알고리즘을 제안한다. 제안된 알고리즘은 주어진 그래프를 분석하여 연산유닛의 개수를 결정하고 이에 따라 각 연산을 제어스텝에 할당한다. 스케줄링 과정 중에 상대적으로 부족한 연산유닛과 여유 있는 연산유닛을 구별하여 연산유닛의 수를 조절한 후 반복적으로 성능개선을 시도하게 된다. 제안된 알고리즘의 성능을 평가하기 위하여 모의실험을 수행하였고 그 결과는 기존의 방법들에 비해 우수함을 알 수 있었다.

• 정보처리학회논문지A
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• 제9A권4호
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• pp.511-518
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• 2002

대칭형 다중프로세서(SMP : Symmetric Multiprocessors) 시스템은 고성능의 병렬 연산을 위한 중요하고 효과적인 기반환경을 제공하고 있다. SMP에서 병렬 태스크와 통신을 위한 스케줄링 기법의 선택은 시스템의 성능에 큰 영향을 미치므로 효과적으로 스케줄링 기법에 대한 연구가 필요하다. 본 논문에서는 버스 기반의 SMP를 위한 태스크 중복을 기반으로 하는 스케줄링 기법을 소개한다. 제안한 스케줄링 기법은 잠재하는 통신 충돌을 방지하기 위하여 네트워크 통신 자원을 사전에 할당한다. 제안한 스케줄링 기법의 성능을 비교하기 위하여 프로세서 수와 통신비용의 변화에 대한 스케줄링 길이를 시뮬레이션을 통하여 조사하였다.

• International Journal of Computer Science & Network Security
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• 제21권1호
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• pp.19-26
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• 2021

CPU is considered the main and most important resource in the computer system. The CPU scheduling is defined as a procedure that determines which process will enter the CPU to be executed, and another process will be waiting for its turn to be performed. CPU management scheduling algorithms are the major service in the operating systems that fulfill the maximum utilization of the CPU. This article aims to review the studies on the CPU scheduling algorithms towards comparing which is the best algorithm. After we conducted a review of the Round Robin, Shortest Job First, First Come First Served, and Priority algorithms, we found that several researchers have suggested various ways to improve CPU optimization criteria through different algorithms to improve the waiting time, response time, and turnaround time but there is no algorithm is better in all criteria.

• 전기학회논문지
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• 제68권3호
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• pp.405-415
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• 2019

The considerations of the electrical device' characteristics and the customers' satisfaction have been important criteria for efficient smart grid systems. In general, an electrical device is classified into a non-interruptible device or an interruptible device. The consideration of the type is an essential information for the efficient smart grid scheduling. In addition, customers' scheduling preferences or satisfactions have to be considered simultaneously. However, the existing research studies failed to consider both criteria. This paper proposes a new and efficient smart grid scheduling framework considering both criteria. The framework consists of two modules - 1) A day-head smart grid scheduling algorithm and 2) Real-time sudden demand negotiation framework. The first method generates the smart grid schedule efficiently using an embedded genetic algorithm with the consideration of the device's characteristics. Then, in case of sudden electrical demands, the second method generates the more efficient real-time smart grid schedules considering both criteria. In order to show the effectiveness of the proposed framework, comparisons with the existing relevant research studies are provided under various electricity demand scenarios.

• International Journal of Computer Science & Network Security
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• 제24권1호
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• pp.215-225
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• 2024

Predictive maintenance has been considered fundamental in the industrial applications in the last few years. It contributes to improve reliability, availability, and maintainability of the systems and to avoid breakdowns. These breakdowns could potentially lead to system shutdowns and to decrease the production efficiency of the manufacturing plants. The present article aims to study how predictive maintenance could be planed into the production scheduling, through a systematic review of literature. . The review includes the research articles published in international journals indexed in the Scopus database. 165 research articles were included in the search using #predictive maintenance# AND #production scheduling#. Press articles, conference and non-English papers are not considered in this study. After careful evaluation of each study for its purpose and scope, 50 research articles are selected for this review by following the 2020 Preferred Reporting Items for Systematic Review and Meta-Analysis Protocols (PRISMA) statement. A benchmarking of predictive maintenance methods was used to understand the parameters that contributed to improve the production scheduling. The results of the comparative analysis highlight that artificial intelligence is a promising tool to anticipate breakdowns. An additional impression of this study is that each equipment has its own parameters that have to be collected, monitored and analyzed.

• 품질경영학회지
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• 제28권1호
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• pp.196-209
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• 2000

In order to intensify an enterprise competition, quality inspection controls are very important issue. An organization or division of a company hopes which to acquire the quality inspection information be updated in real-time with respect to shop floor. In this paper, we develop a quality inspection control system for a Turbine/Generator production industry. The system compromises inspection scheduling module related to shop floor control (SFC) system, formal documentation control module, and formal inspection control module. In the quality inspection control system, ORACLE RDBMS is used for the database management system and ORACLE DEVELOPER 2000 is used for system development tool. The characteristic of this system is to support so it can enhance productivity and quality through inspection plans related to production scheduling.

• 한국군사과학기술학회지
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• 제2권2호
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• pp.83-91
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• 1999

Dynamic characteristic of manufacturing stage is understood and the utilization of each machine is maximized by developing on-line dynamic CAPP system to consider the overloads in the aircraft part manufacturing line. In this paper, a scheme of production planning and scheduling system was proposed through inspection about some predeveloped CAPP system. Developed production planning and scheduling system included process planning module. After precise inspection of some FMS line schema at domestic heavy industry, optimized FMS line was applied to aircraft part manufacturing and repairing factory. By virtue of considering overloads of factory and machine through on-line dynamic CAPP system, the utilization of resources is maximized and manufacturing lead time is minimized.

• 한국정보통신학회논문지
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• 제20권1호
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• pp.52-57
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• 2016

다중 경로 약한 산란 (poor scattering) 전 이중 (full-duplex) 시스템에서 혼성 스케줄링을 소개한다. 제안하는 시스템은 다중 안테나를 갖는 하나의 전 이중 기지국과 수 많은 단일 안테나 반 이중 (half-duplex) 단말로 구성된다. 혼성 스케줄링은 송신기에서의 부분적 채널 정보만을 활용한다. 특별히, 상향링크 및 하향링크에서 모두 기회적 송신 기술을 사용하는 기존 스케줄링 방법과는 달리, 제안하는 기술은 하향링크에서의 랜덤 송신 빔형성 및 상향링크에서의 간섭 제거 빔형성을 결합하여 사용한다. 주요 결과로써, 컴퓨터 모의실험을 통해 제안한 기술이 기존 스케줄링 방법보다 특정 신호 대 잡음비 영역 이상에서 훨씬 더 우수한 합 용량 성능을 가짐을 보인다.

• 방송공학회논문지
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• 제10권1호
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• pp.83-102
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• 2005

The problem of video scheduling is analyzed in the framework of divisible load scheduling. A divisible load can be divided into any number of fractions (parts) and can be processed/computed independently on the processors in a distributed computing system/network, as there are no precedence relationships. In the video scheduling, a frame can be split into any number of fractions (tiles) and can be processed independently on the processors in the network, and then the results are collected to recompose the single processed frame. The divisible load arrives at one of the processors in the network (root processor) and the results of the computation are collected and stored in the same processor. In this problem communication delay plays an important role. Communication delay is the time to send/distribute the load fractions to other processors in the network. and the time to collect the results of computation from other processors by the root processors. The objective in this scheduling problem is that of obtaining the load fractions assigned to each processor in the network such that the processing time of the entire load is a minimum. We derive closed-form expression for the processing time by taking Into consideration the communication delay in the load distribution process and the communication delay In the result collection process. Using this closed-form expression, we also obtain the optimal number of processors that are required to solve this scheduling problem. This scheduling problem is formulated as a linear pro-gramming problem and its solution using neural network is also presented. Numerical examples are presented for ease of understanding.