• Title/Summary/Keyword: tightly-coupled

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Real-time Fault Detection Method for an AGPS/INS Integration System

  • Oh, Sang-Heon;Yoon, Young-Seok;Hwang, Dong-Hwan
    • 제어로봇시스템학회:학술대회논문집
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    • 2003.10a
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    • pp.974-977
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    • 2003
  • The GPS/INS integration system navigation can provide improved navigation performance and has been widely used as a main navigation system for military and commercial vehicles. When two navigation systems are tightly coupled and the structure is complicated, a fault in either the GPS or the INS can lead to a disastrous failure of the whole integration system. This paper proposes a real-time fault detection method for an AGPS/INS integration system. The proposed fault detection method comprises a BIT and a fault detection algorithm based on chi-square test. It is implemented by real-time software modules to apply the AGPS/INS integration system and van test is carried out to evaluate its performance.

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Event Port Extension of OPRoS Framework for Inter-connecting with ROS Topic (ROS 토픽과 결합 가능한 OPRoS 프레임워크의 이벤트 포트 확장 개발)

  • Jang, Choulsoo;Song, Byoungyoul;Kim, Sunghoon
    • Journal of Institute of Control, Robotics and Systems
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    • v.20 no.12
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    • pp.1252-1258
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    • 2014
  • ROS is based on a graph architecture where processing takes place in nodes. Nodes communicate together by passing messages through topics based on the publish/subscribe model. On the other hand, OPRoS components know each other and are tightly-coupled via port connections, and different coupling schemes make the interoperation between two platforms difficult. This paper describes an extension of OPRoS framework to support the interoperation with the ROS topic.

Development of the Reliability Evaluation Model and the Analysis Tool for Embedded Softwares (임베디드 소프트웨어 신뢰성 평가 모델 분석 툴 개발)

  • Seo, Jang-Hoon;Kim, Sun-Ho
    • IE interfaces
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    • v.21 no.1
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    • pp.109-119
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    • 2008
  • Reliability of embedded softwares, as one of factors which affect system reliability, is the probability of failure-free software operation for a specified period of time in a specified environment. and Embedded software is different from general package software because hardware and operating system are tightly coupled to each other. Reliability evaluation models for embedded softwares currently used do not separate estimation and prediction models clearly, and even a standard model has not been proposed yet. In this respect, we choose a reliability estimation model suitable for embedded softwares among software evaluation models being used, and modified the model so as to accomodate recent software environments. In addtion, based on the model, the web-based reliability prediction tool RPX is developed. Finally, an embedded software is analyzed using the tool.

A Shared Library as an Active Memory Object for Application Software Development of Large Scale Real-time Systems (대형 실시간 시스템의 응용 소프트웨어 개발을 위한 능동적 메로리 개체로서의 공유 라이브러리)

  • 정부금;차영준김형환임동선
    • Proceedings of the IEEK Conference
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    • 1998.10a
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    • pp.233-236
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    • 1998
  • In this paper, we present a novel approach named a shared library as an active memory object for application software development of large-scale real-time systems. Unlike the general passive shared memory, shared library proposed in this paper can be activated as an execution object. Moreover this is not tightly coupled with application programs unlike the normal libraries. To implement this mechanism, operating system makes the shared memory as an active object and shared library realizes the indirect call structure. This mechanism enhanced the utilization of main memory and communication performance. And this is successfully applied to the HANbit ACE ATM switching system and the TDX-10 switching system.

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A Study on the Design of Ship's Distributed Remote Control System Using Dual-Microprocessor (이중마이크로프로세서의 이용과 분산처리기법을 도입한 선박용 원격제어 시스템의 설계에 관한 연구)

  • 홍순철;정경열;류길수
    • Journal of Advanced Marine Engineering and Technology
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    • v.18 no.5
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    • pp.78-87
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    • 1994
  • In this paper design and implementation of ship's distributed remote control system using dual-microprocessor is presented for real time process. The proposed system is implemented with the single chip microprocessors in tightly coupled mode and results in speed up of $s_p$=1.74. Under the assumption that the nodes are interconnected in multidrop, the overall system performance such as average throughout-delay characteristics and effective throughput are analyzed using M/G/1 queneing model, and results show that the proposed node can be used in medium sized distributed monitoring and control system.

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A Multi-Level Simulation Technique for Large-ScaleAnalog Integrated Circuits

  • Yang Jeemo
    • Proceedings of the Korea Society for Industrial Systems Conference
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    • 1998.10a
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    • pp.827-834
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    • 1998
  • This paper describes a multi-level simulation technique and its implementation, which accurately solve voltages and currents of circuits descreibed at mixed levels of abstractions. A metho to form a tightly coupled simulation environment is proposed and, starting from a description of a circuit, simulation set-up and analysis procedure of the multi-level simulator for a transient response are presented. Circuit and behavioral simulation techniques and their implementations composing the multi-level simulation are explained in detail. Most of the algorithms implemented in the simulation are based upon the standard simulation techniques in order to obtain the reliability and accuracy of conventinoal simulators. Simulation examples show that the multi-level simulator can analyze circuits containing highly nonlinear behavioral models without loss of accuracy provided the behavioral models are accurate enough.

Testing Method of Embedded Software tightly coupled with Hardware (하드웨어와 결합도가 높은 임베디드 소프트웨어의 단위 테스팅 기법)

  • Sim, Jae-Hwan;Lee, Jin-Ho;Choi, Jin-Young
    • Proceedings of the Korean Information Science Society Conference
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    • 2011.06b
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    • pp.208-211
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    • 2011
  • 하드웨어와 결합도가 높은 임베디드 소프트웨어는 플랫폼의 다양하여 기존의 자동화동 테스팅 도구나 기법을 그대로 적용하기에 어려움이 있다. 특히 단위 테스팅의 경우 디버깅으로 대체 대는 경우가 많아 이후의 단계에서 오류가 탐지 되더라도 오류의 위치를 추정하기에는 어려움이 많다. 본 논문에서는 임베디드 소프트웨어의 테스팅 난점 중 하드웨어와의 결합력과 관련한 어려움을 극복하는 것에 중점을 두고 임베디드 테스팅을 위한 기법을 제시한다.

A Neural Network-Driven Decision Tree Classifier Approach to Time Series Identification (인공신경망 기초 의사결정트리 분류기에 의한 시계열모형화에 관한 연구)

  • 오상봉
    • Journal of the Korea Society for Simulation
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    • v.5 no.1
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    • pp.1-12
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    • 1996
  • We propose a new approach to classifying a time series data into one of the autoregressive moving-average (ARMA) models. It is bases on two pattern recognition concepts for solving time series identification. The one is an extended sample autocorrelation function (ESACF). The other is a neural network-driven decision tree classifier(NNDTC) in which two pattern recognition techniques are tightly coupled : neural network and decision tree classfier. NNDTc consists of a set of nodes at which neural network-driven decision making is made whether the connecting subtrees should be pruned or not. Therefore, time series identification problem can be stated as solving a set of local decisions at nodes. The decision values of the nodes are provided by neural network functions attached to the corresponding nodes. Experimental results with a set of test data and real time series data show that the proposed approach can efficiently identify the time seires patterns with high precision compared to the previous approaches.

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Efficient Data Distribution Service in CPS (CPS에서 효율적인 데이터분배 기술)

  • Lee, Soo-Hyung;Kim, Won-Tae;Ryou, Jae-Cheol
    • IEMEK Journal of Embedded Systems and Applications
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    • v.7 no.5
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    • pp.241-246
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    • 2012
  • As the convergence between the conventional physical systems and IT computing resource is increased, the new paradigm of embedded system called Cyber Physical System (CPS) emerged. CPSs have many sensors, actuators and computing devices to understand and to control the physical system. As these all components are tightly coupled each other, standardized middleware such as Data Distribution Service (DDS) is considered to be deployed. But DDS takes too long time to discover each other in the large-scal CPS environment and has not precise specification of its execution architecture to provide efficient data exchange. In this paper, we design the efficient DDS architecture for development with interoperability to provide the high reliable data distribution. in real-time and propose the communication entity discovery procedure.

Development of WNS/GPS System Using Tightly Coupled Method

  • Yun, Cho-Seong;Park, Chan-Gook;Jee, Gyu-In;Lee, Young-Jea
    • 제어로봇시스템학회:학술대회논문집
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    • 2001.10a
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    • pp.114.5-114
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    • 2001
  • In this paper, the model for personal navigation system using low-cost inertial sensors and error compensation method with GPS are proposed. Simulation is accomplished for the performance test. WNS(Walking Navigation System) is a kind of personal navigation using the number of a walk, stride and azimuth. Because the accuracy of these variables determines the navigational performance, computational methods have been investigated. The step is detected using the motion pattern by walking motion, stride is determined by neural network and azimuth is calculated with gyro´s output. The neural network filters off unnecessary motions. However, error compensation method is needed, because the error of navigation information increases with time ...

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