• Title/Summary/Keyword: 작업 할당 문제

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Semantic Computing-based Dynamic Job Scheduling Model and Simulation (시멘틱 컴퓨팅 기반의 동적 작업 스케줄링 모델 및 시뮬레이션)

  • Noh, Chang-Hyeon;Jang, Sung-Ho;Kim, Tae-Young;Lee, Jong-Sik
    • Journal of the Korea Society for Simulation
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    • v.18 no.2
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    • pp.29-38
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    • 2009
  • In the computing environment with heterogeneous resources, a job scheduling model is necessary for effective resource utilization and high-speed data processing. And, the job scheduling model has to cope with a dynamic change in the condition of resources. There have been lots of researches on resource estimation methods and heuristic algorithms about how to distribute and allocate jobs to heterogeneous resources. But, existing researches have a weakness for system compatibility and scalability because they do not support the standard language. Also, they are impossible to process jobs effectively and deal with a variety of computing situations in which the condition of resources is dynamically changed in real-time. In order to solve the problems of existing researches, this paper proposes a semantic computing-based dynamic job scheduling model that defines various knowledge-based rules for job scheduling methods adaptable to changes in resource condition and allocate a job to the best suited resource through inference. This paper also constructs a resource ontology to manage information about heterogeneous resources without difficulty as using the OWL, the standard ontology language established by W3C. Experimental results shows that the proposed scheduling model outperforms existing scheduling models, in terms of throughput, job loss, and turn around time.

Space-Sharing Scheduling Schemes for NOW with Heterogeneous Computing Power (이질적 계산 능력을 가진 NOW를 위한 공간 공유 스케쥴링 기법)

  • Kim, Jin-Sung;Shim, Young-Chul
    • Journal of KIISE:Computer Systems and Theory
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    • v.27 no.7
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    • pp.650-664
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    • 2000
  • NOW(Network of Workstations) is considered as a platform for running parallel programs by many people. One of the fundamental problems that must be addressed to achieve good performance for parallel programs on NOW is the determination of efficient job scheduling policies. Currently most research on NOW assumes that all the workstations in the NOW have the same processing power. In this paper we consider a NOW in which workstations may have different computing power. We introduce 10 classes of space sharing-based scheduling policies that can be applied to the NOW with heterogeneous computing power. We compare the performance of these scheduling policies by using the simulator which accepts synthetically generated sequential and parallel workloads and generates the response time and waiting time of parallel jobs as performance indices of various scheduling strategies. Through the experiments the case when a parallel program is partitioned heterogeneously in proportion to the computing power of workstations is shown to have better performance than when a parallel program is partitioned into parallel processes of the same size. When the owner returns to the workstation which is executing a parallel process, the policy which just lowers the priority of the parallel process shows better performance than the one which migrates the parallel process to a new idle workstation. Among the policies which use heterogeneous partitioning and process priority lowering, the adaptive policy performed best across the wide range of inter-arrival time of parallel programs but when the load imbalance among parallel processes becomes very high, the modified adaptive policy performed better.

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Scheduling of Parallel Offset Printing Process for Packaging Printing (패키징 인쇄를 위한 병렬 오프셋 인쇄 공정의 스케줄링)

  • Jaekyeong, Moon;Hyunchul, Tae
    • KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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    • v.28 no.3
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    • pp.183-192
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    • 2022
  • With the growth of the packaging industry, demand on the packaging printing comes in various forms. Customers' orders are diversifying and the standards for quality are increasing. Offset printing is mainly used in the packaging printing since it is easy to print in large quantities. However, productivity of the offset printing decreases when printing various order. This is because it takes time to change colors for each printing unit. Therefore, scheduling that minimizes the color replacement time and shortens the overall makespan is required. By the existing manual method based on workers' experience or intuition, scheduling results may vary for workers and this uncertainty increase the production cost. In this study, we propose an automated scheduling method of parallel offset printing process for packaging printing. We decompose the original problem into assigning and sequencing orders, and ink arrangement for printing problems. Vehicle routing problem and assignment problem are applied to each part. Mixed integer programming is used to model the problem mathematically. But it needs a lot of computational time to solve as the size of the problem grows. So guided local search algorithm is used to solve the problem. Through actual data experiments, we reviewed our method's applicability and role in the field.

Scalable and Dynamically Reconfigurable Internet Service System Based on Clustered System (확장과 동적재구성 가능한 클러스터기반의 인터넷서비스 시스템)

  • Kim Dong Keun;Park Se Myung
    • Journal of Korea Multimedia Society
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    • v.7 no.10
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    • pp.1400-1411
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    • 2004
  • Recently, explosion of internet user requires fundamental changes on the architecture of Web service system, from single server system to clustered server system, in parallel with the effort for improving the scalability of the single internet server system. But current cluster-based server systems are dedicated to the single application, for example, One-IP server system. One-IP server system has a clustered computing node with the same function and tries to distribute each request based on the If to the clustered node evenly. In this paper, we implemented the more useful application service platform. It works on shared clustered server(back-end server) with an application server(front-end server) for a particular service. An application server provides a particular service at a low load by itself, but as the load increases, it reconfigures itself with one or more available server from the shared cluster and distributes the load on selected server evenly We used PVM for an effective management of the clustered server. We found the implemented application service platform provides more stable and scalable operation characteristics and has remarkable performance improvement on the dynamic load changes.

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Continuous improvement plan of manufacturing process through real-time data acquisition (실시간 정보획득을 통한 제조공정의 지속적인 개선 방안 연구)

  • Jo, Sung-Ho;Chang, Tai-Woo;Shin, Ki-Tae;Na, Hong-Bum;Park, Jin-Woo
    • Journal of Korea Society of Industrial Information Systems
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    • v.14 no.4
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    • pp.75-90
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    • 2009
  • Improvement of productivity and efficient process management need to define the problem of the previous work. If it takes long time to gather necessary information, it becomes difficult to continuously manage processes to satisfy customers' needs and to enhance business efficiency. This paper proposes methods and a context awareness system for decision making to solve problems originated in management of manufacturing process through real-time information acquisition. We implement the context awareness by suggesting decision logics that automatically classify works with acquired information. And we also implement a system for case study which makes workers recognize problems and notifies instructions to them. Consistency between real object and stored data and continuous process monitoring with this system could find inefficient resources or delayed works, resolve them and improve processes efficiency.

A Study on the Interference Effects between UWB and T-DMB Systems (UWB 시스템과 T-DMB 시스템간의 간섭 영향에 관한 연구)

  • Koo, Sung-Wan;Kim, Jin-Young
    • The Journal of The Korea Institute of Intelligent Transport Systems
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    • v.8 no.6
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    • pp.82-87
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    • 2009
  • Recently, a great variety of radio services are provided and interference problem between radio systems is being watched remarkably. Therefore, a study of interference between radio systems is needed. In this paper, compatibility between Ultra Wideband (UWB) and Terestrial Digital Multi-media Broadcasting (T-DMB) is analyzed and then distance between them is computed. UWB systems have a very broad frequency characteristic. A big advantage is to share frequency that is already allocated to other systems. T-DMB is a good point that while L-Band is already used for DAB, T_DMB is free of charge. AT-DMB (Advanced T-DMB) is being standardized recently. The result which is analyzed for the interference effects between UWB and T-DMB Systems is 10 [dB], which is value calculated by C/(N0+I), at 80 [m] and then the value is saturated at 150 [m].

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Analysis and Advice on Cache Algorithms of SSD FTL (SSD FTL 캐시 알고리즘 분석 및 제언)

  • Hyung Bong, Lee;Tae Yun, Chung
    • KIPS Transactions on Computer and Communication Systems
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    • v.12 no.1
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    • pp.1-8
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    • 2023
  • It is impossible to overwrite on an already allocated page in SSDs, so whenever a write operation occurs a page replacement with a clean page is required. To resolve this problem, SSDs have an internal flash translation layer called FTL that maps logical pages managed by a file system of operating system to currently allocated physical pages. SSD pages discarded due to write operations must be recycled through initialization, but since the number of initialization times is limited the FTL provides a caching function to reduce the number of writes in addition to the page mapping function, which is a core function. In this study, we focus on the FTL cache methodologies reducing the number of page writes and analyze the related algorithms, and propose a write-only cache strategy. As a result of experimenting with the write-only cache using a simulator, it showed an improvement of up to 29%.

Development of a Fleet Management System for Cooperation Among Construction Equipment (건설장비 협업을 위한 플릿관리 시스템 개발)

  • Ahn, Seo-Hyun;Kim, Sung-Keun;Lee, Kwan-Hoon
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.36 no.3
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    • pp.573-586
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    • 2016
  • In construction jobs, a combination of various kinds of machinery is used to perform earthworks at a large-scale site. Individual equipments essentially cooperate with each other on task such as excavation, load, transfer and compaction. While other area have studied cooperation system, related study in domestic construction is in poor condition. In this study, construction equipment fleet management system is developed for solving this problem and find way to improving efficiency in earthworks site. The entire concept of the fleet management system, including its components and process, has been systematically outlined in this paper. An operational methodology has also been suggested, where a number of machines, such as the excavators, trucks and compactors, are chosen and further grouped into a cluster. A case study verify fleet management system's effectiveness on performing task package by comparing existing work method with methodology in this study. Fleet management system in this study is expected to curtail fuel consumption by the reduction of working time and moving distance. Furthermore, it can be anticipated to declining carbon emission effect.

An Efficient Cleaning Scheme for File Defragmentation on Log-Structured File System (로그 구조 파일 시스템의 파일 단편화 해소를 위한 클리닝 기법)

  • Park, Jonggyu;Kang, Dong Hyun;Seo, Euiseong;Eom, Young Ik
    • Journal of KIISE
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    • v.43 no.6
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    • pp.627-635
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    • 2016
  • When many processes issue write operations alternately on Log-structured File System (LFS), the created files can be fragmented on the file system layer although LFS sequentially allocates new blocks of each process. Unfortunately, this file fragmentation degrades read performance because it increases the number of block I/Os. Additionally, read-ahead operations which increase the number of data to request at a time exacerbates the performance degradation. In this paper, we suggest a new cleaning method on LFS that minimizes file fragmentation. During a cleaning process of LFS, our method sorts valid data blocks by inode numbers before copying the valid blocks to a new segment. This sorting re-locates fragmented blocks contiguously. Our cleaning method experimentally eliminates 60% of file fragmentation as compared to file fragmentation before cleaning. Consequently, our cleaning method improves sequential read throughput by 21% when read-ahead is applied.

A Reliable Broadcast Scheme for Wireless Sensor Networks (무선 센서 네트워크를 위한 신뢰적 브로드캐스팅 기법)

  • Choi, Won-Suk;Cho, Sung-Rae
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.33 no.4B
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    • pp.165-173
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    • 2008
  • In this paper, we propose a new reliable broadcast protocol referred to as timer-based reliable broadcast (TRB) for wireless sensor networks (WSNs). The proposed TRB scheme exploits (1) bitmap based explicit ACK to effectively reduce the unnecessary error control messages and (2) randomized timer for ACK transmission to substantially reduce the possibility of contentions. Although it has been argued that 100% reliability is not necessary in WSNs, there should be messages (such as mission-critical message, task assignment, software updates, etc.) that need to be reliably delivered to the entire sensor field. We propose to use the TRB algorithm for such cases. Performance evaluation shows that the TRB scheme achieves 100 % reliability significantly better than other schemes with expense of slightly increased energy consumption.