• Title/Summary/Keyword: Real-Time Scheduling System

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A Study on the Expanded R/R Scheduling in Priority-based $\mu{C/OS-II}$ Kernel (우선순위 기반의 $\mu{C/OS-II}$ 커널에서 확장된 R/R 스케줄링 연구)

  • 김태호;김창수
    • Journal of Korea Multimedia Society
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    • v.5 no.3
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    • pp.323-330
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    • 2002
  • Recently, the existing embedded real-time operating systems(RTOSs) are being developed in terms of various modified versions in every application fields. Major characteristics and difference of these OSs lie in their distinct development of mechanisms which can be used in various environment and task-scheduling function which can control time-limited contingencies. In this paper, we design and implement round/robin scheduling algorithm based on time-sharing with equal-priority for multiple tasks which are provided preemptive and priority task allocation function in $\mu{C/OS-II}$ version 2.03. We propose the most important event-ready list structure in $\mu{C/OS-II}$; kernel, and provide the running result for multiple tasks with equal priority for the proposed structure.

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Design and Implementation of Real-Time Progress Management System Using UML (Unified Modeling Language) - The Focus on Steel Structural Construction - (UML을 이용한 실시간 진도관리 시스템의 설계 및 구현 - 로봇 크레인 기반 철골공사를 중심으로 -)

  • Park, Jung-Lo;Kim, Kyung-Hwan;Kim, Jael-Jun
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2009.05b
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    • pp.163-166
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    • 2009
  • All sorts of technique for schedule progress management is being developed recently, These can change and develop the abstractive concept model to a detailed model that describes the visual 3D image about a schedule plan. but, this technique is troublesome, because this requires the handwork by means of connection between 3D-CAD and scheduling Program. In this study, the process of real-time schedule progress control system using the integrated database by 3D-CAD object information system and schedule module is presented. This study present the process of a schedule progress management using UML, and the process of real-time schedule progress management using RFID system. Through this study, we want to realize the rapid generation of estimated schedule information and to simulate and analyze actual schedule information by real-time.

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Mechanism for Managing Fault-Tolerant Embedded Real-Time Tasks (결함허용이 가능한 임베디드 실시간 태스크 관리 메커니즘)

  • Jung, Kyung-Hoon;Tak, Sung-Woo;Kim, Chang-Soo
    • Journal of Korea Multimedia Society
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    • v.10 no.7
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    • pp.882-892
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    • 2007
  • In this paper, we propose a mechanism for both scheduling the hybrid-task set which consists of periodic and aperiodic tasks and recovering tasks with transient faults on the level of the operating system. Existing embedded operating systems would not provide the scheduling of both periodic and aperiodic tasks. Also because of not supporting the recovery of task failures, they can not prevent system failure from transient task faults. Proposed method, on the level of operating system, is able to not only meet the deadlines of all periodic tasks but also complete the execution of aperiodic tasks. In addition, it is able to prevent the system failure from transient task faults by recovering the task faults.

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A study on the trend and selection for scheduling technology of embedded operating system (임베디드 운영체제의 스케줄링 기술 동향 및 선정에 관한 연구)

  • Min, Jae-Hong;Cho, Pyung-Dong;Hahm, Jin-Ho
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2011.05a
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    • pp.629-632
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    • 2011
  • Embedded operation system is core software technology which will be able to implement the ubiquitous environment. Also, it is basic technology which has a great ripple effect. Therefore, it is advanced and greatly changed for recent several years. Especially, a lot of studies have been done on real-time supporting technology relating to embedded operating system. In this paper, I analyze the characteristics of real-time embedded system and the trend of scheduling technique in order to support them. As a result, I suggest selection technique for selecting scheduling algorithm through considering the characteristics of embedded system.

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A Study on the Sway Control of a Container Crane Based on $H^{\infty}$ Gain-Scheduling Approach ($H^{\infty}$ Gain-Scheduling 기법을 이용한 컨테이너 크레인의 흔들임 제어에 관한 연구)

  • Kim, Yeong-Bok;Jeong, Yong-Gil
    • Journal of Institute of Control, Robotics and Systems
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    • v.7 no.7
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    • pp.559-566
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    • 2001
  • The sway control problem of the pendulum motion of a container hanging on the trolly, which transports containers from a container ship to trucks, is considered in the paper. In the container crane control problem, suppressing the residual swing motion of the container at the end of acceleration, deceleration or the case of that the unexpected disturbance input exists is main issue. For this problem, in general, the trolley motion control strategy is introduced and applied. In this paper, we introduce and synthesize a new type of swing motion control system in which a small auxiliary mass is installed on the spreader. The actuator reacting against the auxiliary mall applies inertial control forces to the container to reduce the swing motion in the desired manner. In this paper, we apply the $H^{\infty}$ based gain-scheduling control technique to the anti-swing motion control system design problem of the controlled plant. In this control system, the controller dynamics are adjusted in real-time according to time-varying plant parameters. And the simulation result shows that the proposed control strategy is shown to be useful for the case of time-varying system and, robust to disturbances such as winds and initial sway motion.

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Cross-layer Dynamic Subcarrier Allocation with Adaptive Service Rate Control in SC-FDMA System

  • Ye, Fang;Su, Chunxia;Li, Yibing;Zhang, Xu
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.11 no.10
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    • pp.4823-4843
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    • 2017
  • In this paper, an improved utility-based cross-layer dynamic subcarrier allocation (DSA) algorithm is proposed for single carrier frequency division multiple access (SC-FDMA) system, which adopts adaptive service rate control (ASRC) to eliminate the service rate waste and improve the spectral efficiency in heterogeneous network including non-real-time traffic and real-time traffic. In this algorithm, furthermore, a first in first out (FIFO) queuing model with finite space is established on the cross-layer scheduling framework. Simulation results indicate that by taking the service rate constraint as the necessary condition for optimality, the ASRC algorithm can effectively eliminate the service rate waste without compromising the scheduling performance. Moreover, the ASRC algorithm is able to further improve the quality of service (QoS) performance and transmission throughput by contributing an attractive performance trade-off between real-time and non-real-time applications.

[ ${\mu}TMO$ ] Model based Real-Time Operating System for Sensor Network (${\mu}TMO$ 모델 기반 실시간 센서 네트워크 운영체제)

  • Yi, Jae-An;Heu, Shin;Choi, Byoung-Kyu
    • Journal of KIISE:Computer Systems and Theory
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    • v.34 no.12
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    • pp.630-640
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    • 2007
  • As the range of sensor network's applicability is getting wider, it creates new application areas which is required real-time operation, such as military and detection of radioactivity. However, existing researches are focused on effective management for resources, existing sensor network operating system cannot support to real-time areas. In this paper, we propose the ${\mu}TMO$ model which is lightweight real-time distributed object model TMO. We design the real-time sensor network operation system ${\mu}TMO-NanoQ+$ which is based on ETRI's sensor network operation system Nano-Q+. We modify the Nano-Q+'s timer module to support high resolution and apply Context Switch Threshold, Power Aware scheduling techniques to realize lightweight scheduler which is based on EDF. We also implement channel based communication way ITC-Channel and periodic thread management module WTMT.

Real-Time Scheduling Method to assign Virtual CPU in the Multocore Mobile Virtualization System (멀티코아 모바일 가상화 시스템에서 가상 CPU 할당 실시간 스케줄링 방법)

  • Kang, Yongho;Keum, Kimoon;Kim, Seongjong;Jin, Kwangyoun;Kim, Jooman
    • Journal of Digital Convergence
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    • v.12 no.3
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    • pp.227-235
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    • 2014
  • Mobile virtualization is an approach to mobile device management in which two virtual platforms are installed on a single wireless device. A smartphone, a single wireless device, might have one virtual environment for business use and one for personal use. Mobile virtualization might also allow one device to run two different operating systems, allowing the same phone to run both RTOS and Android apps. In this paper, we propose the techniques to virtualize the cores of a multicore, allowing the reassign any number of vCPUs that are exposed to a OS to any subset of the pCPUs. And then we also propose the real-time scheduling method to assigning the vCPUs to the pCPU. Suggested technology in this paper solves problem that increases time of real-time process when interrupt are handled, and is able more to fast processing than previous algorithm.

A Construction of TMO Object Group Model for Distributed Real-Time Services (분산 실시간 서비스를 위한 TMO 객체그룹 모델의 구축)

  • 신창선;김명희;주수종
    • Journal of KIISE:Computer Systems and Theory
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    • v.30 no.5_6
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    • pp.307-318
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    • 2003
  • In this paper, we design and construct a TMO object group that provides the guaranteed real-time services in the distributed object computing environments, and verify execution power of its model for the correct distributed real-time services. The TMO object group we suggested is based on TINA's object group concept. This model consists of TMO objects having real-time properties and some components that support the object management service and the real-time scheduling service in the TMO object group. Also TMO objects can be duplicated or non-duplicated on distributed systems. Our model can execute the guaranteed distributed real-time service on COTS middlewares without restricting the specially ORB or the of operating system. For achieving goals of our model. we defined the concepts of the TMO object and the structure of the TMO object group. Also we designed and implemented the functions and interactions of components in the object group. The TMO object group includes the Dynamic Binder object and the Scheduler object for supporting the object management service and the real-time scheduling service, respectively The Dynamic Binder object supports the dynamic binding service that selects the appropriate one out of the duplicated TMO objects for the clients'request. And the Scheduler object supports the real-time scheduling service that determines the priority of tasks executed by an arbitrary TMO object for the clients'service requests. And then, in order to verify the executions of our model, we implemented the Dynamic Binder object and the Scheduler object adopting the binding priority algorithm for the dynamic binding service and the EDF algorithm for the real-time scheduling service from extending the existing known algorithms. Finally, from the numerical analyzed results we are shown, we verified whether our TMO object group model could support dynamic binding service for duplicated or non-duplicated TMO objects, also real-time scheduling service for an arbitrary TMO object requested from clients.