• Title/Summary/Keyword: slack time

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A Soft Aperiodic Real-Time Task Scheduling Algorithm Supporting Maximum Slack Time (최대여유시간 제공 연성 비주기 실시간 태스크 스케줄링 알고리즘)

  • Im, Deok-Ju;Park, Seong-Han
    • Journal of the Institute of Electronics Engineers of Korea CI
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    • v.37 no.4
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    • pp.9-15
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    • 2000
  • The purpose of this paper is to minimize the a slack computation time of the scheduling of a soft aperiodic real-time tasks in a fixed priority real-time system. The proposed algorithm reduces the computation overhead at on-line time and supports the maximum slack time assigned for aperiodic real-time tasks. The proposed algorithm has 10~20% more response time for aperiodic real-time tasks than that of Slack Stealing Algorithm that offers optimal response time in fixed priority real-time system. However, the performance of the proposed algorithm is seven times better in a scheduling overhead.

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Extended Slack Stealing Algorithm for Improve Response Time of Aperiodic Tasks (비주기 태스트의 응답시간을 개선하기 위해 확장한 슬랙 스틸링 알고리즘)

  • Choi, Man-Uk;Han, Dae-Man;Koo, Yong-Wan
    • The Transactions of the Korea Information Processing Society
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    • v.7 no.7
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    • pp.2229-2237
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    • 2000
  • This paper intends to improve the problems of the slack stealing algorithm scheduling for periodic tasks with fixed priority and aperiodic tasks which occur dynamically. The Slack stealing algorithm reduces unnecessary waiting time by making the service possible immediately when the slack stealing server gives suitable priority to aperiodic tasks according to the status of aperiodic tasks arrivals at runtime. But no performs the slack stealing, we must calculate execution time of periodic tasks till the point of random. And, execution time of periodic tasks is being repeatedly every hours while the slack algorithm is applied. We show time complexity hen is used as to O(n) if the nubmer of tasks which is applied to the calculation is n. In this appear, due to stored in tables slack times and the execution times of the scheduled periodic tasks, the complexity of aperiodic tasks which is occurring dynamically reduced to O(log n) and improves the responses times. We prove the algorithm proposed in this paper through the simulation.

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Mitigation of Budgetary Slack Behavior Through Islamic Religiosity and Budget Control: An Empirical Study of Indonesian Local Companies

  • LAKASSE, Syarifuddin;HAMZAH, Muh. Nasir;ABDULLAH, M. Wahyuddin;SYAHRUDDIN, Syahruddin
    • The Journal of Asian Finance, Economics and Business
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    • v.8 no.8
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    • pp.355-363
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    • 2021
  • This study aims to obtain empirical evidence about the cognitive effect of Islamic religiosity and budget control in reducing budgetary slack behavior. This study involved 176 managers as respondents in 10 local companies in Eastern Indonesia. Managers who are respondents in thus study work and are spread across 14 provinces in Indonesia. Probability sampling method has been used for this study from the total population with certain criteria. Data analysis has been done using Warp PLS-SEM technique. The results showed that Islamic religiosity cognitive and budget control had a direct negative effect on budgetary slack behavior. The two variables also fully mediate the relationship between participatory budgeting and budget-based compensation schemes on the behavior of budgetary slack in a negative and significant way. These results mean that the two variables are proven to reduce budgetary slack behavior. This empirical evidence at the same time corrects the agency theory's assumptions about opportunistic human nature and always maximizes every potential economic profit. In addition, the results also show that Islamic religiosity cognitive is stronger in reducing budgetary slack behavior. These results can be used to improve the company's budget control system by incorporating elements that motivate religious goals so that it is more effective in reducing budgetary slack behavior.

Dynamic Voltage Scaling Algorithms for Hard Real-Time Systems Using Efficient Slack Time Analysis (효율적인 슬랙 분석 방법에 기반한 경성 실시간 시스템에서의 동적 전압 조절 방안)

  • 김운석;김지홍;민상렬
    • Journal of KIISE:Computer Systems and Theory
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    • v.30 no.12
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    • pp.736-748
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    • 2003
  • Dynamic voltage scaling(DVS), which adjusts the clock speed and supply voltage dynamically, is an effective technique in reducing the energy consumption of embedded real-time systems. The energy efficiency of a DVS algorithm largely depends on the performance of the slack estimation method used in it. In this paper, we propose novel DVS algorithms for periodic hard real-time tasks based on an improved slack estimation algorithm. Unlike the existing techniques, the proposed method can be applied to most priority-driven scheduling policies. Especially, we apply the proposed slack estimation method to EDF and RM scheduling policies. The experimental results show that the DVS algorithms using the proposed slack estimation method reduce the energy consumption by 20∼40 % over the existing DVS algorithms.

Energy-aware Management in Wireless Body Area Network System

  • Zhang, Xu;Xia, Ying;Luo, Shiyan
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.7 no.5
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    • pp.949-966
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    • 2013
  • Recently, Wireless Body Area Network (WBAN) has promise to revolutionize human daily life. The need for multiple sensors and constant monitoring lead these systems to be energy hungry and expensive with short operating lifetimes. In this paper, we offer a review of existing work of WBAN and focus on energy-aware management in it. We emphasize that nodes computation, wireless communication, topology deployment and energy scavenging are main domains for making a long-lived WBAN. We study the popular power management technique Dynamic Voltage and Frequency Scaling (DVFS) and identify the impact of slack time in Dynamic Power Management (DPM), and finally propose an enhanced dynamic power management method to schedule scaled jobs at slack time with the goal of saving energy and keeping system reliability. Theoretical and experimental evaluations exhibit the effectiveness and efficiency of the proposed method.

Optimistic Concurrency Control considering Slack Time in RTDB (RTDB에서의 여유시간을 고려한 낙관적 동시성 제어 기법 연구)

  • 김병곤;이순미;임해철
    • Proceedings of the Korean Information Science Society Conference
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    • 1998.10b
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    • pp.66-68
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    • 1998
  • 실시간 데이터베이스 시스템에 있어서 동시성 제어는 제한시간을 달성하기 위한 중요한 요소중의 하나이다. 본 연구에서는 효율적인 실시간 데이터베이스 동시성 제어를 위한 알고리즘을 제안하다. 이 알고리즘은 실시간 데이터베이스에 적합한 낙관적 동시성 제어 기법(Optimistic Concurrency Control)을 근간으로 하며, 종료 트랜잭션의 여유시간(slack time)을 고려하여 좀더 많은 수행 트랜잭션의 마감시간 달성에 목표를 두었다.

Optimal Signal Times for Active Bus Signal Priority on Median Bus Lane Using Deterministic Delay Model (중앙버스전용차로상에서 결정적 지체모형을 이용한 능동형 버스우선신호의 최적 신호시간 산출방안)

  • Kim, Tae-Woon;Jeong, Young-Je;Kim, Young-Chan
    • The Journal of The Korea Institute of Intelligent Transport Systems
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    • v.13 no.1
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    • pp.15-25
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    • 2014
  • Bus signal priority is a name for various techniques to speed up bus public transport services at intersections with traffic signals. In this study propose methodology to optimize signal times for Early green, Green extension out of the active bus signal priority using deterministic delay model in isolated intersection on median bus lane. Fluctuation is found in the vehicle delay and person delay in the event that using this methodology redistributed to green time and checking slack green time is correct value by sensitivity analysis. As a result of the study, car delay is increased a little and person delay is decreased. As a result of slack green time sensitivity, delay is not much in it if variation of slack green time under 30%. But this methodology effectiveness is under claimed capacity if variation of slack green time over 30%.

A Study on the Heuristic Solution for n/m Job-Shop Scheduling Problems of Slack Degree (Slack Degree에 의한 n/m Job-Shop 스케줄링 문제의 발견적 해법에 관한 연구)

  • 김제홍;조남호
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.19 no.39
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    • pp.275-284
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    • 1996
  • It can be made a definition that scheduling is a imposition of machinery and equipment to perform a collection of tasks. Ultimately scheduling is an assessment of taking order for which would be perform. So it is called "sequencing" in other words. In a job shop scheduling, the main object is to making delivery in accordance with the due date and order form customer, not to producing lots of quantity with minimizing mean flow time in a given time. Actually, in a company, they concentrate more in the delivery than minimizing the mean flow time. Therefore this paper suggest a new priority dispatching rule under consideration as below in a n/m job shop scheduling problem with due date. 1. handling/transportation time, 2. the size of customer order With this algorithm, we can make a scheduling for minimizing the tardiness of delivery which satisfy a goal of production.roduction.

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A Frequency Selection Algorithm for Power Consumption Minimization of Processor in Mobile System (이동형 시스템에서 프로세서의 전력 소모 최소화를 위한 주파수 선택 알고리즘)

  • Kim, Jae Jin;Kang, Jin Gu;Hur, Hwa Ra;Yun, Choong Mo
    • Journal of Korea Society of Digital Industry and Information Management
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    • v.4 no.1
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    • pp.9-16
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    • 2008
  • This paper presents a frequency selection algorithm for minimization power consumption of processor in Mobile System. The proposed algorithm has processor designed low power processor using clock gating method. Clock gating method has improved the power dissipation by control main clock through the bus which is embedded clock block applying the method of clock gating. Proposed method has compared power consumption considered the dynamic power for processor, selected frequency has considered energy gain and energy consumption for designed processor. Or reduced power consumption with decreased processor speed using slack time. This technique has improved the life time of the mobile systems by clock gating method, considered energy and using slack time. As an results, the proposed algorithm reduce average power saving up to 4% comparing to not apply processor in mobile system.

Post-Silicon Tuning Based on Flexible Flip-Flop Timing

  • Seo, Hyungjung;Heo, Jeongwoo;Kim, Taewhan
    • JSTS:Journal of Semiconductor Technology and Science
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    • v.16 no.1
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    • pp.11-22
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    • 2016
  • Clock skew scheduling is one of the essential steps to be carefully performed during the design process. This work addresses the clock skew optimization problem integrated with the consideration of the inter-dependent relation between the setup and hold times, and clock to-Q delay of flip-flops, so that the time margin is more accurately and reliably set aside over that of the previous methods, which have never taken the integrated problem into account. Precisely, based on an accurate flexible model of setup time, hold time, and clock-to-Q delay, we propose a stepwise clock skew scheduling technique in which at each iteration, the worst slack of setup and hold times is systematically and incrementally relaxed to maximally extend the time margin. The effectiveness of the proposed method is shown through experiments with benchmark circuits, demonstrating that our method relaxes the worst slack of circuits, so that the clock period ($T_{clk}$) is shortened by 4.2% on average, namely the clock speed is improved from 369 MHz~2.23 GHz to 385 MHz~2.33 GHz with no time violation. In addition, it reduces the total numbers of setup and hold time violations by 27.7%, 9.5%, and 6.7% when the clock periods are set to 95%, 90%, and 85% of the value of Tclk, respectively.