• Title/Summary/Keyword: embedded real-time systems

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Power-aware Real-time Task Scheduling in Dependable Embedded Systems (신뢰도를 요구하는 임베디드 시스템에서의 저전력 태스크 스케쥴링)

  • Kim, Kyong Hoon;Kim, Yuna;Kim, Jong
    • IEMEK Journal of Embedded Systems and Applications
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    • v.3 no.1
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    • pp.25-29
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    • 2008
  • In this paper, we provide an adaptive power-aware checkpointing scheme for fixed priority-based DVS scheduling in dependable real-time systems. In the provided scheme, we analyze the minimum number of tolerable faults of a task and the optimal checkpointing interval in order to meet the deadline and guarantee its specified reliability. The energy-efficient voltage level at a fault arrival is also analyzed and used in the recovery of the faulty task.

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Real-Time Functional Reactive Program Translator for Embedded Systems (임베디드 시스템을 위한 실시간 함수형 반응적 프로그램 변환기)

  • Lee, Dong-Ju;Woo, Gyun
    • The KIPS Transactions:PartA
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    • v.13A no.6 s.103
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    • pp.481-488
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    • 2006
  • FRP(Functional Reactive Programming) is a kind of embedded language in Haskell, it declaratively program reactive system based on two essential high-order types named behavior and events. This Paper design and implementation RT-FRP(Real-time Functional Reactive Programming) translator for using FRP in embedded systems with many constraints. The RT-FRP translator generates a C Program from an RT-FRP program according to the operational semantics of the RT-FRP language. To show the effectiveness of the RT-FRP translator, we loaded and executed the test program generated by the translator onto a real embedded system, LEGO Mindstorm. According to the experimental result, the reactive system software can be programmed more concisely using RT-FRP than using an imperative counter part although the size of the binary code is rather increased.

VTF: A Timer Hypercall to Support Real-time of Guest Operating Systems (VIT: 게스트 운영체제의 실시간성 지원을 위한 타이머 하이퍼콜)

  • Park, Mi-Ri;Hong, Cheol-Ho;Yoo, See-Hwan;Yoo, Chuck
    • Journal of KIISE:Computer Systems and Theory
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    • v.37 no.1
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    • pp.35-42
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    • 2010
  • Guest operating systems running over the virtual machines share a variety of resources. Since CPU is allocated in a time division manner it consequently leads them to having the unknown physical time. It is not regarded as a serious problem in the server virtualization fields. However, it becomes critical in embedded systems because it prevents guest OS from executing real time tasks when it does not occupy CPU. In this paper we propose a hypercall to register a timer service to notify the timer request related real time. It enables hypervisor to schedule a virtual machine which has real time tasks to execute, and allows guest OS to take CPU on time to support real time. The following experiment shows its implementation on Xen-Arm and para-virtualized Linux. We also analyze the real time performance with response time of test application and frames per second of Mplayer.

Ajax interfaced web server for embedded Linux system (임베디드 리녹스 시스템 기반 Aiax 인터페이스 웹 서버 기법)

  • Hong, Hang-Seol;Kim, Seong-Hwan;Park, Jang-Hyeon
    • Proceedings of the Korean Institute of Intelligent Systems Conference
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    • 2007.11a
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    • pp.253-256
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    • 2007
  • The web server for the embedded Linux system(ELS), unlike the ones for the usual Linux or Windows, has some disadvantages such as small number of installable applications, low compatibility and limited extensibility. This fact raises some problems when data are transferred in real-time via the web server, which are mainly caused by a poor performance of the processor and small-sized memory. Conventional user interfaces adopted for the usual web servers are unsuitable for the ELS because they are platform-limited and their installations are done by the form of plug-ins. If the web server for the ELS has an Ajax engine that can be utilized without any installation procedure, the advantages of usability, accessibility and quick response time can be obtained. This paper presents the Ajax interface for the ELS web server. The efficiency of the proposed technology in the real-time remote monitoring is shown through an implementation.

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Designing of Network based Tiny Ubiquitous Networked Systems (네트워크 기반의 소형 유비쿼터스 시스템의 개발)

  • Hwang, Kwang-Il;Eom, Doo-Seop
    • Journal of KIISE:Computing Practices and Letters
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    • v.13 no.3
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    • pp.141-152
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    • 2007
  • In this paper, we present a network-oriented lightweight real-time system, which is composed of an event-driven operating system called the Embedded Lightweight Operating System (ELOS) and a generic multi hop ad hoc routing protocol suite. In the ELOS, a conditional preemptive FCFS scheduling method with a guaranteed time slot is designed for efficient real-time processing. For more elaborate configurations, we reinforce fault tolerance by supplementing semi-auto configuration using wireless agent nodes. The developed hardware platform is also introduced, which is a scalable prototype constructed using off-the-shelf components. In addition, in order to evaluate the performance of the proposed system, we developed a ubiquitous network test-bed on which several experiments with respect to various environments are conducted. The results show that the ELOS is considerably favorable for tiny ubiquitous networked systems with real-time constraints.

Design and Evaluation Method of Linux Based Soft Real-Time Kernel for Information Devices (정보기기들을 위한 리눅스 기반 연성 실시간 커널의 설계 및 평가 방법)

  • Jung, YungJoon;Lim, Donghyouk;Lim, Chaedeok;Choi, Hoon
    • IEMEK Journal of Embedded Systems and Applications
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    • v.6 no.6
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    • pp.393-400
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    • 2011
  • Recently, demands of information devices are increasing as we can find so many information devices around us such as smartphone, MID(Mobile Internet Device), Tablet. These characteristics of information devices services should support soft real-time based time guaranteed multimedia services and control internet appliances. In this situation, soft real-time supported system should be developed to consider as a total aspect of hardware, kernel, middleware, application. But this paper will describe soft real-time supporting and evaluation methods for information device as an aspect of only kernel.

Development of Unmanned Driving Technologies for Speed Sprayer in Orchard Environment (과수원 환경에서의 방제기 무인주행 기술 개발)

  • Li, Song;Kang, Dongyeop;Lee, Hae-min;An, Su-yong;Kwon, Wookyong;Chung, Yunsu
    • IEMEK Journal of Embedded Systems and Applications
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    • v.15 no.6
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    • pp.269-279
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    • 2020
  • This paper presents the design and implementation of embedded systems and autonomous path generation for autonomous speed sprayer. Autonomous Orchard Systems can be divided into embedded controller and path generation module. Embedded controller receives analog sensor data, on/off switch data and control linear actuator, break, clutch and steering module. In path generation part, we get 3D cloud point using Velodyne VLP16 LIDAR sensor and process the point cloud to generate maps, do localization, generate driving path. Then, it finally generates velocity and rotation angle in real time, and sends the data to embedded controller. Embedded controller controls steering wheel based on the received data. The developed autonomous speed sprayer is verified in test-bed with apple tree-shaped artworks.

A Study on Data Structure and Processing for Battlefield Information Management (전장정보관리를 위한 데이터 구조 및 처리에 관한 연구)

  • Baek, Joo-Hyun
    • Journal of the Korea Institute of Military Science and Technology
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    • v.10 no.2
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    • pp.5-11
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    • 2007
  • In digital warfare, communications between combat vehicles should be managed and synchronized in order to ensure the survivability of vehicles. Embedded battle management systems is designed to share battle information with combat vehicles in real-time. In this study, the details of embedded battle management systems which are successfully implemented in combat vehicles are presented.

The Design and Implementation of a Real-Time Database Engine For Embedded Systems (내장형 시스템을 위한 실시간 데이터베이스 엔진 설계 및 구현)

  • 김흥섭;문승진
    • Journal of Internet Computing and Services
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    • v.3 no.5
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    • pp.19-29
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    • 2002
  • With the progress of information-oriented society, many device with advanced technologies invented by many companies. However, the current firmware technologies have many problems to meet such high level of new Technologies, Recently it become necessary new manufactures of information-oriented society to require such embedded operating system as their system-level platform. Embedded linux, which could be on alternative proposal of existing high-cost embedded operating system, become available commercially by many companies Linux has many programs, But, embedded databases require very high cost. In this paper, we suggest ERT DE which has a small size and is suitable for embedded real-time technologies.

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Real-time Reagent Management System Using NFC / Sensor (NFC/센서를 이용한 실시간 시약 관리 시스템)

  • Kim, Ho-Sung;Jang, Jae-Myung;Jung, Hoe-Kyung
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.20 no.2
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    • pp.421-426
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    • 2016
  • Recent developments in internet technologies has enabled widespread growth of embedded systems like Arduino, Raspberry Pi and other smart home systems. A research in the industrial sector on the utilization of the board has been made. The development needs of the embedded board in a reagent bottle case system has been highlighted. Current reagent Management System has to hold and manage the reagent itself is mostly to save the program using handwritten or machine. In addition, there is a risk to the system during the vulnerable zone administrator to manage the situation of the reagent bottle case can lead to a massive fire. In this paper, reagent bottle case RFID readers and data in real-time is monitored by attaching a sensor management through the database and sends a warning message to the mobile device of the administrator in real time during hazardous situations in the reagent bottle case. This is improve the reliability and efficiency of reagent bottle case.