• Title/Summary/Keyword: Priority Algorithm

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A maximal-Flow Scheduling Using time Expanded Network in a track (시간 전개형 네트워크를 이용한 선로의 최대흐름 스케쥴링)

  • 이달상;김만식
    • Journal of Korean Society of Transportation
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    • v.8 no.2
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    • pp.67-75
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    • 1990
  • This paper treats the problem to schedule for trains with how transit priority so as to maximizing the number that can be sent during given time periods without interfering with the fixed schedule for train with high transit priority in a track. We transform the this problem into Time Expanded Network without traverse time through application of Ford and Fulkerson Model and construct the Enumeration Algorithm for solutions using TENET Generator (TENETGEN). Finally, we compare our algorithm with Dinic's Maximal-Flow Algorithm and examine the avaliability of our procedures in personal computer.

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A Modified-DWRR Cell Scheduling Algorithm improved the QoS of Delay (지연 특성을 개선한 Modified-DWRR 셀 스케쥴링 알고리즘)

  • Gwak, Ji-Yeong;Nam, Ji-Seung
    • The KIPS Transactions:PartC
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    • v.8C no.6
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    • pp.805-814
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    • 2001
  • In this paper, we propose a new scheduling algorithm that guarantees the delay property of real-time traffic, not considered in previous DWRR(Dynamic Weighted Round Robin) algorithm and also transmits non-real-time traffic efficiently. The proposed scheduling algorithm is a variation of DWRR algorithm to guarantee the delay property of real-time traffic by adding cell transmission method based on delay priority. It also uses the threshold to prevent the cell loss of non-real-time traffic due to cell transmission method based on delay priority. Proposed scheduling algorithm may increase some complexity over conventional DWRR scheme because of cell transmission method based on delay priority. However, the consideration of delay priority can minimize cell delay and require less size of temporary buffer. Also, the results of our performance study shows that the proposed scheduling algorithm has better performance than conventional DWRR scheme due to reliable ABR service and congestion avoidance capacity.

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Downlink Wireless Adaptive Modulation and Coding Scheme (AMC)-based Priority Queuing Scheduling Algorithm for Multimedia Services

  • Park, Seung-Young;Kim, Dong-Hoi
    • Journal of Korea Multimedia Society
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    • v.10 no.12
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    • pp.1622-1631
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    • 2007
  • To realize the wireless packet scheduler which efficiently considers both the effect of adaptive modulation and coding (AMC) scheme due to variable wireless communication channel information from physical layer and the QoS differentiation of multimedia services from internet protocol (IP) layer, this paper proposes a new downlink AMC-based priority queuing (APQ) scheduler which combines AMC scheme and service priority method in multimedia services at the same time. The result of numerical analysis shows that the proposed APQ algorithm plays a role in increasing the number of services satisfying the mean waiting time requirements per each service in multimedia services because the APQ scheme allows the mean waiting time of each service to be reduced much more than existing packet scheduler having only user selection processor.

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Performance analysis of a loss priority control scheme in an input and output queueing ATM switch (입출력 단에 버퍼를 가지는 ATM 교환기의 손실우선순위 제어의 성능 분석)

  • 이재용
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.22 no.6
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    • pp.1148-1159
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    • 1997
  • In the broadband integrated service digital networks (B-ISDN), ATM switches hould be abld to accommodate diverse types of applications ith different traffic characteristics and quality ddo services (QOS). Thus, in order to increase the utilization of switches and satisfy the QOS's of each traffic type, some types of priority control schemes are needed in ATM switches. In this paper, a nonblocking input and output queueing ATm switch with capacity C is considered in which two classes of traffics with different loss probability constraints are admitted. 'Partial push-out' algorithm is suggested as a loss priority control schemes, and the performance of this algorithm is analyzed when this is adopted in input buffers of the switch. The quque length distribution of input buffers and loss probabilities of each traffic are obtained using a matrix-geometric solution method. Numerical analysis and simulation indicate that the utilization of the switch with partial push-out algorithm satisfying the QOS's of each traffic is much higher than that of the switch without control. Also, the required buffer size is reduced while satisfying the same QOS's.

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Multi-Item Inventory Problems Revisited Using Genetic Algorithm

  • Das, Prasun
    • Management Science and Financial Engineering
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    • v.13 no.2
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    • pp.29-46
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    • 2007
  • This paper makes an attempt to compare the two important methods for finding solutions of multi-item inventory problem with more than one conflicting objectives. Panda et al.[9] discusses a distance-based method to find the best possible compromise solution with variation of priority under the given weight structure. In this paper, the problem in [9] is revisited through the Pareto-optimal front of genetic algorithm with the help of a situation of retail stocking of FMCG business. The advantages of using the solutions from the perspective of the decision maker obtained through multi-objective optimization are highlighted in terms of population search, weighted goals and priority structure, cost, set of compromise solutions along with prevention of stock-out situation.

Bandwidth Tracing Arbitration Algorithm for Mixed-Clock Systems with Dynamic Priority Adaptation

  • Kwon, Young-Su;Kyung, Chong-Min
    • Proceedings of the IEEK Conference
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    • 2003.07b
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    • pp.959-962
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    • 2003
  • At the processing capabilities and operating frequency of embedded system are growing, so is the needed data bandwidth to fully utilize the processing capability. The ability to transfer huge amount of data between the embedded core and external devices is required for efficient system operation. In this paper, the data communication architecture for the mixed-clock system is proposed. The dynamic priority adaptation algorithm for bus arbitration is proposed for bandwidth guarantee. The communication architecture that incorporates the proposed arbitration algorithm adapts the priority of communication components dynamically based on the information from FIFO. The experiments show that the measured bandwidth of each component traces the required bandwidth well compared to the other arbitration algorithms

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A Two-Step Job Scheduling Algorithm Based on Priority for Cloud Computing

  • Kim, Jeongwon
    • Journal of information and communication convergence engineering
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    • v.11 no.4
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    • pp.235-240
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    • 2013
  • Cloud systems are popular computing environment because they can provide easy access to computing resources for users as well as efficient use of resources for companies. The resources of cloud computing are heterogeneous and jobs have various characteristics. One such issue is effective job scheduling. Scheduling in the cloud system may be defined as a multiple criteria decision model. To address this issue, this paper proposes a priority-based two-step job scheduling algorithm. On the first level, jobs are classified based on preference. Resources are dedicated to a job if a deadline failure would cause severe results or critical business losses. In case of only minor discomfort or slight functional impairment, the job is scheduled using a best effort approach. On the second level, jobs are allocated to adequate resources through their priorities that are calculated by the analytic hierarchic process model. We then analyze the proposed algorithm and make a scheduling example to confirm its efficiency.

Hybrid Priority-based Genetic Algorithm for Multi-stage Reverse Logistics Network

  • Lee, Jeong-Eun;Gen, Mitsuo;Rhee, Kyong-Gu
    • Industrial Engineering and Management Systems
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    • v.8 no.1
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    • pp.14-21
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    • 2009
  • We formulate a mathematical model of remanufacturing system as multi-stage reverse Logistics Network Problem (mrLNP) with minimizing the total costs for reverse logistics shipping cost and inventory holding cost at disassembly centers and processing centers over finite planning horizons. For solving this problem, in the 1st and the 2nd stages, we propose a Genetic Algorithm (GA) with priority-based encoding method combined with a new crossover operator called as Weight Mapping Crossover (WMX). A heuristic approach is applied in the 3rd stage where parts are transported from some processing centers to one manufacturer. Computer simulations show the effectiveness and efficiency of our approach. In numerical experiments, the results of the proposed method are better than pnGA (Prufer number-based GA).

Deciding the Maintenance Priority of Power Distribution System using Time-varying Failure Rate (시변 고장률을 이용한 배전계통 유지보수 우선순위 결정)

  • Lee, Hee-Tae;Moon, Jong-Fil;Kim, Jae-Chul
    • The Transactions of the Korean Institute of Electrical Engineers A
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    • v.55 no.11
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    • pp.476-484
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    • 2006
  • The failure prediction and preventive maintenance for the equipment of nuclear power plant area using reliability-centered maintenance have been grown. On the other hand, the maintenance for power distribution system consists of time-based maintenance mainly. In this paper, the new maintenance algorithms for power distribution system are developed considering reliability indices. First of all, Time-varying failure rates are extracted from data accumulated at KEPCO using exponential distribution function and weibull distribution function. Next, based on the extracted failure rate, reliability for real power distribution system is evaluated for applying the effective maintenance algorithm which is the analytic method deciding the maintenance point of time and searching the feeder affecting the specific customer. Also the algorithm deciding the maintenance priority order are presented based on sensitivity analysis and equipment investment plan are analyzed through the presented algorithm at real power distribution system.

An Analysis of Network Resource Wasteness for a Priority Control Algorithm using Hop Count in ATM-based Connectionless Networks (ATM 기반 비연결형 망에서 홉 카운터를 이용한 우선 순위 제어 알고리즘의 망 자원 손실 비용 분석)

  • Cha, Hyeon-Cheol
    • Journal of KIISE:Computer Systems and Theory
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    • v.26 no.1
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    • pp.64-71
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    • 1999
  • 본 논문에서는 공중 광역 ATM망 환경에서 비연결형 서비스 제공에 사용되는 CLS에 적용될 수 있는 홉 카운터를 이용한 우선 순위 제어 알고리즘(Priority Control Algorithm using Hop-Count : HC-PC)의 망 자원 손실 비용을 분석하였다. 분석을 통해 우선 순위가 없을 경우 (No Priority Controls Algorithm: NO-Pc) 의 평균 셀 손실률이 HC-PC 의 평균 셀 손실률의 가중 평균보다 크거나 같은 경우 항상 NO-PC 이 평균 망 자원 손실 비용이 HC-PC 의 평균 망 자원 손실 비용에 비해 크다는 사실을 보였다. 시뮬레이션 결과는 분석에 의해 찾아진 조건이 만족됨을 보여주며 HC-PC가 NO-PC에 비해 어떠한 환경에서든지 항상 낮은 평균 망 자원 손실 비용을 가짐을 보여 준다.