• 제목/요약/키워드: Real Time Scheduling

검색결과 876건 처리시간 0.028초

시각물체 추적 시스템을 위한 멀티코어 프로세서 기반 태스크 스케줄링 방법 (A Task Scheduling Strategy in a Multi-core Processor for Visual Object Tracking Systems)

  • 이민채;장철훈;선우명호
    • 한국자동차공학회논문집
    • /
    • 제24권2호
    • /
    • pp.127-136
    • /
    • 2016
  • The camera based object detection systems should satisfy the recognition performance as well as real-time constraints. Particularly, in safety-critical systems such as Autonomous Emergency Braking (AEB), the real-time constraints significantly affects the system performance. Recently, multi-core processors and system-on-chip technologies are widely used to accelerate the object detection algorithm by distributing computational loads. However, due to the advanced hardware, the complexity of system architecture is increased even though additional hardwares improve the real-time performance. The increased complexity also cause difficulty in migration of existing algorithms and development of new algorithms. In this paper, to improve real-time performance and design complexity, a task scheduling strategy is proposed for visual object tracking systems. The real-time performance of the vision algorithm is increased by applying pipelining to task scheduling in a multi-core processor. Finally, the proposed task scheduling algorithm is applied to crosswalk detection and tracking system to prove the effectiveness of the proposed strategy.

RM 스케쥴링과 Lock-Free 공유개체에 의한 실시간 시뮬레이션 (The Real-Time Constructive Simulation With the RM scheduling and Lock-free Shared Objects)

  • 박현규
    • 대한전자공학회:학술대회논문집
    • /
    • 대한전자공학회 1998년도 추계종합학술대회 논문집
    • /
    • pp.519-522
    • /
    • 1998
  • The Constructive Battle simulation Model is very important to the recent military training for the substitution of the field training. However, real battlefield systems operate under rea-time conditions, they are inherently distributed, concurrent and dynamic. In order to reflect these properties by the computer-based simulation systems which represent real world processes, we have been developing constructive simulation model for several years. The constructive simulation system is one of the famous real-time system software, nd the one common feature of all real-time systems is defined as the correctness of the system depend not only on the logical result of computation, but also on the time at which the results are produced. Conventionally, scheduling and resource allocation activities which have timing constraints are major problem of real-time computing systems. To overcome these constraints, we elaborated on these issues and developed the simulation system on commercially available hardware and operating system with lock-free resource allocation scheme and rae monotonic scheduling.

  • PDF

Energy Join Quality Aware Real-time Query Scheduling Algorithm for Wireless Sensor Networks

  • Phuong, Luong Thi Thu;Lee, Sung-Young;Lee, Young-Koo
    • 한국정보처리학회:학술대회논문집
    • /
    • 한국정보처리학회 2011년도 춘계학술발표대회
    • /
    • pp.92-96
    • /
    • 2011
  • Nowadays, the researches study high rate and real-time query applications seem to be real-time query scheduling protocols and energy aware real time query protocols. Also the WSNs should provide the quality of data in real time query applications that is more and more popular for wireless sensor networks (WSNs). Thus we propose the quality of data function to merge into energy efficiency called energy join quality aware realtime query scheduling (EJQRTQ). Our work calculate the energy ratio that considers interference of queries, and then compute the expected quality of query and allocate slots to real-time preemptive query scheduler.

CAN기반 실시간 시스템을 위한 확장된 EDS 알고리즘 개발 (Development of an Extended EDS Algorithm for CAN-based Real-Time System)

  • 이병훈;김대원;김홍렬
    • 대한전기학회:학술대회논문집
    • /
    • 대한전기학회 2001년도 하계학술대회 논문집 D
    • /
    • pp.2369-2373
    • /
    • 2001
  • Usually the static scheduling algorithms such as DMS (Deadline Monotonic Scheduling) or RMS(Rate Monotonic Scheduling) are used for CAN scheduling due to its ease with implementation. However, due to their inherently low utilization of network media, some dynamic scheduling approaches have been studied to enhance the utilization. In case of dynamic scheduling algorithms, two considerations are needed. The one is a priority inversion due to rough deadline encoding into stricted arbitration fields of CAN. The other is an arbitration delay due to the non-preemptive feature of CAN. In this paper, an extended algorithm is proposed from an existing EDS(Earliest Deadline Scheduling) approach of CAN scheduling algorithm haying a solution to the priority inversion. In the proposed algorithm, the available bandwidth of network media can be checked dynamically by all nodes. Through the algorithm, arbitration delay causing the miss of their deadline can be avoided in advance. Also non real-time messages can be processed with their bandwidth allocation. The proposed algorithm can achieve full network utilization and enhance aperiodic responsiveness, still guaranteeing the transmission of periodic messages.

  • PDF

CAM에서의 사례의존규칙을 이용한 실시간 일정계획 (Real Time Scheduling for Computer-Aided Manufacturing ( CAM ) Systems with Instance-Based Rules)

  • 이종태
    • 대한산업공학회지
    • /
    • 제17권2호
    • /
    • pp.63-74
    • /
    • 1991
  • An expert scheduling system on real time basis for computer-aided manufacturing systems has been developed. In developing expert scheduling system, the most time-consuming job is to obtain rules from expert schedulers. An efficient process of obtaining rules directly form the schedules produced by expert schedulers is proposed. By the process, a set of complete and minimal set of rules is obtained. During a real time scheduling, when given information on possible values of elements, the rules produce possible values of decision elements, where logical explanations of the result may be offered in terms of chaining rules. The learning and scheduling processes have been simulated with an automated manufacturing line engaged in the production of circuit boards.

  • PDF

Event-Driven Real-Time Simulation Based On The RM Scheduling and Lock-free Shared Objects

  • Park, Hyun Kyoo
    • 한국국방경영분석학회지
    • /
    • 제25권1호
    • /
    • pp.199-214
    • /
    • 1999
  • The Constructive Battle Simulation Model is very important to the recent military training for the substitution of the field training. However, real battlefield systems operate under real-time conditions, they are inherently distributed, concurrent and dynamic. In order to reflect these properties by the computer-based simulation systems which represent real world processes, we have been developing constructive simulation model for several years. Conventionally, scheduling and resource allocation activities which have timing constraints, we elaborated on these issues and developed the simulation system on commercially available hardware and operating system with lock-free resource allocation scheme and rate monotonic scheduling.

  • PDF

한정된 전력량을 가진 멀티프로세서 시스템에서 (m,k)-firm 데드라인 태스크를 위한 실시간 스케줄링 기법 (Real-time Scheduling for (m,k)-firm Deadline Tasks on Energy-constrained Multiprocessors)

  • 공연화;조현중
    • 정보처리학회논문지:컴퓨터 및 통신 시스템
    • /
    • 제2권6호
    • /
    • pp.237-244
    • /
    • 2013
  • 본 연구에서는 전력량 제약을 가진 멀티프로세서 시스템에서 (m,k)-firm 데드라인을 갖는 실시간 태스크를 효율적으로 스케줄링 할 수 있는 방법으로 EMRTS-MK(Energy-constrained Multiprocessor Real-Time Scheduling algorithms for (m,k)-firm deadline constrained tasks) 를 제안한다. EMRTS-MK는 단지 전력 소모량을 최소로 줄이는 것이 목표가 아니라 한정된 전력량을 고려하여 시스템이 주어진 임무 시간(Mission Time) 동안 최소한의 서비스 품질을 보장하고 동시에 가능하면 최대한의 서비스 품질을 제공함을 목표로 한다. 본 연구에서는 상용멀티코어 환경에서 EMRTS-MK를 구현하여 성능을 평가하였으며, 제안된 알고리즘이 (m,k)-firm 데드라인을 갖는 멀티미디어 서비스를 효과적으로 지원해 줄 수 있다는 것을 보였다.

반도체 자동화 생산을 위한 실시간 일정계획 시스템 재 구축에 관한 연구 : 300mm 반도체 제조라인 적용 사례 (Real-Time Scheduling System Re-Construction for Automated Manufacturing in a Korean 300mm Wafer Fab)

  • 최성우;이정승
    • 지능정보연구
    • /
    • 제15권4호
    • /
    • pp.213-224
    • /
    • 2009
  • 본 연구는 국내 300mm 웨이퍼를 이용하여 반도체 제품의 제조라인을 대상으로 수행 되었던 자동화 생산을 위한 일정계획 시스템 재 구축 프로젝트에 관한 내용이다. 본 프로젝트의 주요 목적은 반도체 제조라인 내의 세정, 확산, 포토, 증착과 같은 주요공정들을 대상으로 효율적인 일정계획 수립 알고리듬을 개발하고 그것을 실시간 일정계획 시스템에 구현함으로써 반도체 제조라인의 자동화 생산률을 향상시키는 것이다. 본 논문에서는 여러가지 주요 공정들 중 제한된 대기시간 제약과 배치공정의 특성이 존재하는 세정과 확산으로 이루어진 연속공정 구간을 대상으로 개발된 일정계획 알고리듬과 실시간 일정계획 시스템의 개발에 대한 내용에 초점을 두었다. 일정계획 시스템 재 구축 프로젝트가 시작 될 시점에 세정과 확산 공정의 자동화 생산률은 각각 50%와 10% 정도 였으나, 프로젝트 수행 완료 후에는 각각 91%와 83% 까지 자동화 생산률이 향상 되었다. 자동화 생산률의 향상은 작업자의 인건비 절감, 생산성의 향상, 지속적이고 편차 없는 생산을 의미한다.

  • PDF

Energy-efficient Scheduling of Periodic Real-time Tasks on Heterogeneous Grid Computing Systems

  • Lee, Wan Yeon;Choi, Yun-Seok
    • International Journal of Internet, Broadcasting and Communication
    • /
    • 제9권2호
    • /
    • pp.78-86
    • /
    • 2017
  • In this paper, we propose an energy-efficient scheduling scheme for real-time periodic tasks on a heterogeneous Grid computing system. The Grid system consists of heterogeneous processors providing the DVFS mechanism with a finite set of discrete clock frequencies. In order to save energy consumption, the proposed scheduling scheme assigns each real-time task to a processor with the least energy increment. Also the scheme activates a part of all available processors with unused processors powered off. Evaluation shows that the proposed scheme saves up to 70% energy consumption of the previous method.

주문형 생산에서의 실시간 납기 산정 (Real-time Delivery Estimation in Build-to-order Manufacturing)

  • 홍태영;강무진;박세형;이상봉
    • 한국정밀공학회:학술대회논문집
    • /
    • 한국정밀공학회 2002년도 추계학술대회 논문집
    • /
    • pp.101-104
    • /
    • 2002
  • Leading companies have embraced the new economy with new and innovative BTO models. Instead of conventional company-oriented manufacturing scheduling, customer-oriented scheduling method attracts more and more attention. To evaluate the delivery of customer order in advance, the real production capacity as well as procurement lead time should be taken into account. This paper describes a quasi-real-time order delivery estimation system using TOC(Theory of Constraints) based scheduling method.

  • PDF