• Title/Summary/Keyword: real-time scheduling

Search Result 871, Processing Time 0.031 seconds

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

  • Lee, Minchae;Jang, Chulhoon;Sunwoo, Myoungho
    • Transactions of the Korean Society of Automotive Engineers
    • /
    • v.24 no.2
    • /
    • 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.

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

  • 박현규
    • Proceedings of the IEEK Conference
    • /
    • 1998.10a
    • /
    • 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
    • Proceedings of the Korea Information Processing Society Conference
    • /
    • 2011.04a
    • /
    • 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.

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

  • Lee, Byong-Hoon;Kim, Dae-Won;Kim, Hong-Ryeol
    • Proceedings of the KIEE Conference
    • /
    • 2001.07d
    • /
    • 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

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

  • Rhee, Jong-Tae
    • Journal of Korean Institute of Industrial Engineers
    • /
    • v.17 no.2
    • /
    • 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
    • Journal of the military operations research society of Korea
    • /
    • v.25 no.1
    • /
    • 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

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

  • Kong, Yeonhwa;Cho, Hyeonjoong
    • KIPS Transactions on Computer and Communication Systems
    • /
    • v.2 no.6
    • /
    • pp.237-244
    • /
    • 2013
  • We propose Energy-constrained Multiprocessor Real-Time Scheduling algorithms for (m,k)-firm deadline constrained tasks (EMRTS-MK). Rather than simply saving as much energy as possible, we consider energy as hard constraint under which the system remains functional and delivers an acceptable performance at least during the prescribed mission time. We evaluate EMRTS-MKs in several experiments, which quantitatively show that they achieve the scheduling objectives.

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

  • Choi, Seong-Woo;Lee, Jung-Seung
    • Journal of Intelligence and Information Systems
    • /
    • v.15 no.4
    • /
    • pp.213-224
    • /
    • 2009
  • This paper describes a real-time scheduling system re-construction project for automated manufacturing at a 300mm wafer fab of Korean semiconductor manufacturing company. During executing this project, for each main operation such as clean, diffusion, deposition, photolithography, and metallization, each adopted scheduling algorithm was developed, and then those were implemented in a real-time scheduling system. In this paper, we focus on the scheduling algorithms and real-time scheduling system for clean and diffusion operations, that is, a serial-process block with the constraint of limited queue time and batch processors. After this project was completed, the automated manufacturing utilizations of clean and diffusion operations became around 91% and 83% respectively, which were about 50% and 10% at the beginning of this project. The automated manufacturing system reduces direct operating costs, increased throughput on the equipments, and suggests continuous and uninterrupted processings.

  • 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
    • /
    • v.9 no.2
    • /
    • 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.

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

  • 홍태영;강무진;박세형;이상봉
    • Proceedings of the Korean Society of Precision Engineering Conference
    • /
    • 2002.10a
    • /
    • 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