• Title/Summary/Keyword: Scheduling

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Worst-case Guaranteed Scheduling Algorithm for HR-WPAN (HR-WPAN을 위한 Worst-case Guaranteed Scheduling Algorithm)

  • Kim, Je-Min;Lee, Jong-Kyu
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.32 no.5B
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    • pp.270-276
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    • 2007
  • The proposed LDS(Link-status Dependent Scheduling) algorithm in HR-WPAN(High Rate-Wireless Personal Area Network) up to now aims at doing only throughput elevation of the whole network, when the crucial device is connected with worst-link relatively, throughput of this device becomes aggravation. The proposed the WGS(Worst-case Guaranteed Scheduling) algorithm in this paper guarantees throughput of the device which is connected with worst-link in a certain degree as maintaining throughput of all devices identically even if a link-status changes, decreases delay of the whole network more than current LDS algorithm. Therefore proposed WGS algorithm in this paper will be useful in case of guaranteeing throughput of a device which is connected worst-link in a certain degree in a design of HR-WPAN hereafter.

The techniques of object-based reservation scheduling (객체에 근거한 예약 스케줄링 기법)

  • 김진봉;백청호
    • Journal of the Korea Computer Industry Society
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    • v.5 no.2
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    • pp.227-233
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    • 2004
  • Complex scheduling problems are related to planning, scheduling, constraint satisfaction problems, object-oriented concepts, and agent systems. Human preference-driven scheduling technique was to solve complex scheduling problems using constraint satisfaction problems and object-oriented concepts. We have tried to apply human preference-driven scheduling technique to reservation problems. For customer's satisfaction, we have considered customer's preferences in the reservation scheduling. The technique of reservation scheduling proposed in this thesis is based on object-oriented concepts. 1'o consider the over all satisfaction, the events of every object are alloted to the board along its priority. Constraints to reservation scheduling are classified to global and local. The definition of board and information of every event are global constraints and the preferences to object's board slots are local constraints. We have applied look-ahead technology to reservation scheduling in order to minimize backtracking not to fail the allotment of events.

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Analysis of Boundary Conditions for Activities' Relationships in Linear Scheduling Model (선형 공정계획 모델의 액티비티 관계의 경계조건 분석)

  • Ryu, Han-Guk;Kim, Tae-Hui
    • Korean Journal of Construction Engineering and Management
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    • v.12 no.1
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    • pp.23-32
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    • 2011
  • Domestic leading construction companies has been establishing and performing TACT scheduling method, similar to linear scheduling model such as line of balance and repetitive schedule, and etc. in which repetitive construction works are involved like high-rise building. Linear scheduling model has been researched as a visual scheduling method presenting the work space and time information. Likewise scheduling constraints of CPM network such as finish-to-finish, start-to-start, finish-to-start, start-to-start, linear scheduling model also has the relationships constraints, namely boundary conditions, between activities. It is especially necessary to define the boundary conditions of the activities' relationships in order to apply the linear scheduling model to be compatible with the network schedule. Therefore, this research considers the boundary conditions between activities for establishing the linear scheduling model. This paper also applies the proposed boundary conditions to TACT schedule and then deduces the main considerations in order to establish and perform TACT schedule.

A Study on Low Power Force-Directed scheduling for Optimal module selection Architecture Synthesis (최적 모듈 선택 아키텍쳐 합성을 위한 저전력 Force-Directed 스케쥴링에 관한 연구)

  • Choi Ji-young;Kim Hi-seok
    • Proceedings of the IEEK Conference
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    • 2004.06b
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    • pp.459-462
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    • 2004
  • In this paper, we present a reducing power consumption of a scheduling for module selection under the time constraint. A a reducing power consumption of a scheduling for module selection under the time constraint execute scheduling and allocation for considering the switching activity. The focus scheduling of this phase adopt Force-Directed Scheduling for low power to existed Force-Directed Scheduling. and it constructs the module selection RT library by in account consideration the mutual correlation of parameters in which the power and the area and delay. when it is, in this paper we formulate the module selection method as a multi-objective optimization and propose a branch and bound approach to explore the large design space of module selection. Therefore, the optimal module selection method proposed to consider power, area, delay parameter at the same time. The comparison experiment analyzed a point of difference between the existed FDS algorithm and a new FDS_RPC algorithm.

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A Study on Method for solving Fuzzy Environment-based Job Shop Scheduling Problems (퍼지 환경을 고려한 Job Shop에서의 일정계획 방법에 관한 연구)

  • 홍성일;남현우;박병주
    • Journal of the Society of Korea Industrial and Systems Engineering
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    • v.20 no.41
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    • pp.231-242
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    • 1997
  • This paper describe an approximation method for solving the minimum makespan problem of job shop scheduling with fuzzy processing time. We consider the multi-part production scheduling problem in a job shop scheduling. The job shop scheduling problem is a complex system and a NP-hard problem. The problem is more complex if the processing time is imprecision. The Fuzzy set theory can be useful in modeling and solving scheduling problems with uncertain processing times. Lee-Li fuzzy number comparison method will be used to compare processing times that evaluated under fuzziness. This study propose heuristic algorithm solving the job shop scheduling problem under fuzzy environment. In This study the proposed algorithm is designed to treat opinions of experts, also can be used to solve a job shop environment under the existence of alternate operations. On the basis of the proposed method, an example is presented.

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Simulation Models for Investigation of Multiuser Scheduling in MIMO Broadcast Channels

  • Lee, Seung-Hwan;Thompson, John S.
    • ETRI Journal
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    • v.30 no.6
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    • pp.765-773
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    • 2008
  • Spatial correlation is a result of insufficient antenna spacing among multiple antenna elements, while temporal correlation is caused by Doppler spread. This paper compares the effect of spatial and temporal correlation in order to investigate the performance of multiuser scheduling algorithms in multiple-input multiple-output (MIMO) broadcast channels. This comparison includes the effect on the ergodic capacity, on fairness among users, and on the sum-rate capacity of a multiuser scheduling algorithm utilizing statistical channel state information in spatio-temporally correlated MIMO broadcast channels. Numerical results demonstrate that temporal correlation is more meaningful than spatial correlation in view of the multiuser scheduling algorithm in MIMO broadcast channels. Indeed, the multiuser scheduling algorithm can reduce the effect of the Doppler spread if it exploits the information of temporal correlation appropriately. However, the effect of spatial correlation can be minimized if the antenna spacing is sufficient in rich scattering MIMO channels regardless of the multiuser scheduling algorithm used.

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An Excel-Based Scheduling System for a Small and Medium Sized Manufacturing Factory (중소 제조기업을 위한 엑셀기반 스케쥴링 시스템)

  • Lee, Chang-Su;Choe, Kyung-Il;Song, Young-Hyo
    • Journal of Korean Society for Quality Management
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    • v.36 no.2
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    • pp.28-35
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    • 2008
  • This study deals with an Excel-based scheduling system for a small and medium sized manufacturing factory without sufficient capability for managing full-scale information systems. The factory has the bottleneck with identical machines and unique batching characteristics. The scheduling problem is formulated as a variation of the parallel-machine scheduling system. It can be solved by a two-phase method: the first phase with an ant colony optimization (ACO) heuristic for order grouping and the second phase with a mixed integer programming (MIP) algorithm for scheduling groups on machines.

Personnel Scheduling of Restaurant using Integer Programming (정수계획법을 이용한 외식인력 스케줄링)

  • Choi, Kyu-Wan
    • Korean Journal of Community Nutrition
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    • v.12 no.5
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    • pp.630-638
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    • 2007
  • The purpose of this study is to investigate an efficient use of labor in personnel scheduling for the restaurant industry. More specifically, this study attends to reduce overall labor cost while not sacrificing both full-time and part-time employees' schedules. The customers' demands were measured by sales in this analysis. Historically, server scheduling in the restaurant has been practiced by manager's experience and intuition; however, those practices provided drawbacks because managers often fail to consider external factors such as a employees' working conditions and change in a restaurant's size. The result of a new method in personnel scheduling provided significant cost saving compared to a previous scheduling technique. This study found that a new method in personnel scheduling allowed the restaurant to save labor cost. The outcome of this study should of for important strategic implication for the restaurant managers.

Agent-Based Scheduling for Semiconductor Wafer Fabrication Facilities (반도체 웨이퍼 팹의 에이전트 기반 스케쥴링 방법)

  • Yoon, Hyun Joong
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.29 no.11 s.242
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    • pp.1463-1471
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    • 2005
  • This paper proposes an agent-based scheduling method fur semiconductor wafer fabrication facilities with hard inter-operation temporal constraints. The scheduling problem is to find the feasible schedules that guarantee both logical and temporal correctness. A proposed multi-agent based architecture is composed of scheduling agents, workcell agents, and machine agents. A scheduling agent computes optimal schedules through bidding mechanisms with a subset or entire set of the workcell agents. A dynamic planning-based approach is adopted for the scheduling mechanism so that the dynamic behaviors such as aperiodic job arrivals and reconfiguration can be taken into consideration.

LSB 스케줄링기법의 소개

  • Park Chang Gyu;Kim Hyeon Jun
    • Proceedings of the Korean Operations and Management Science Society Conference
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    • 2002.05a
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    • pp.944-948
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    • 2002
  • In industrial production setting scheduling problems of detalied day-to-day operations are often ordeals to production practitioners. For those who have scheduling experience with the Gantt Chart, the job oriented heuristic scheduling has illustrated its merits in solving practically large stale scheduling problems. It schedules all operations of a job within a finite capacity before considering the next job. This paper introduces a new LSB (load smoothing backward) scheduling algorithm for the job oriented heuristic scheduling. Through the computer simulation in a hypothetical setting, this paper provides a comparison of LSB scheduling with existing algorithms and a guideline for selecting the suitable algorithm for certain industrial setting.

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