• Title, Summary, Keyword: Real-time Computation

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A Theoretic Foundation of Imprecise Computation (근사값 계산 방안에 대한 이론적 연구)

  • Park, Dong-Won
    • The Journal of Natural Sciences
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    • v.7
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    • pp.115-120
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    • 1995
  • Imprecise computation has been suggested as a promising model of real-time computing in order to deal with timing constraints imposed by the environment. However, the theoretical foundation of the technique has not been fully explored. To address this, a decision-theoretic foundation of imprecise computation is proposed. The main benefit of such a treatment is that it enables the qualitative assumptions underlying imprecise computation techniques to be explicitly stated in a formal way. The theoretical foundation laid out in this paper, hence, will not only enable the justification of using imprecise computation techniques for a real-time application, but will also facilitate the development of extended techniques for more complexs real-time systems.

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Dynamic Model of PEM Fuel Cell Using Real-time Simulation Techniques

  • Jung, Jee-Hoon;Ahmed, Shehab
    • Journal of Power Electronics
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    • v.10 no.6
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    • pp.739-748
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    • 2010
  • The increased integration of fuel cells with power electronics, critical loads, and control systems has prompted recent interest in accurate electrical terminal models of the polymer electrolyte membrane (PEM) fuel cell. Advancement in computing technologies, particularly parallel computation techniques and various real-time simulation tools have allowed the prototyping of novel apparatus to be investigated in a virtual system under a wide range of realistic conditions repeatedly, safely, and economically. This paper builds upon both advancements and provides a means of optimized model construction boosting computation speeds for a fuel cell model on a real-time simulator which can be used in a power hardware-in-the-loop (PHIL) application. Significant improvement in computation time has been achieved. The effectiveness of the proposed model developed on Opal RT's RT-Lab Matlab/Simulink based real-time engineering simulator is verified using experimental results from a Ballard Nexa fuel cell system.

Efficiency of a Symbolic Computation Method for the Real Time Simulation (실시간 시뮬레이션을 위한 기호연산기법의 유용성 검증에 관한 연구)

  • Choe, Dae-Han;Yu, Wan-Seok
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.24 no.7
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    • pp.1878-1884
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    • 2000
  • In multibody dynamic analysis, one of the most important problems is to reduce computation times for real time simulation. In this paper, a symbolic computation method is implemented and tested for each dynamic analysis step. Applying symbolic formulations to the vehicle dynamics program AutoDyn7, the effectiveness of the symbolic computation method is verified.

A Study on the Real-Time Analysis of a 6×6 Autonomous Vehicle (6×6 자율주행 차량의 실시간 해석을 위한 연구)

  • Cho, Du-Ho;Lee, Jung-Han;Yi, Ki-Chang;Yoo, Wan-Suk
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.33 no.12
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    • pp.1433-1441
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    • 2009
  • In multibody dynamic analysis, one of the most important problems is to reduce computation times for real-time simulation. This paper presents the derivation procedure of equations of motion of a 6${\times}$6 autonomous vehicle in terms of chassis local coordinates which do not require coordinates transformation matrix to enhance efficiency for real-time dynamic analysis. Also, equations of motion are derived using the VT(velocity transformation) technique and symbolic computation method coded by MATLAB. The Jacobian matrix of the equations of motion of a system is derived from symbolic operations to apply the implicit integration method. The analysis results were compared with ADAMS results to verify the accuracy and approve the feasibility of real time analysis.

Stability of Time Delay Systems Using Numerical Computation of Argument Principles

  • Suh, Young-Soo
    • International Journal of Control, Automation, and Systems
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    • v.1 no.1
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    • pp.127-133
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    • 2003
  • This paper proposes a new numerical method to check the stability of a general class of time delay systems. The proposed method checks whether there are characteristic roots whose real values are nonnegative through two steps. Firstly, rectangular bounds of characteristic roots whose real values are nonnegative are computed. Secondly, the existence of roots inside the bounds are checked using the numerical computation of argument principles. An adaptive discretization is proposed for the numerical computation of argument principles.

Analyses of Computation Time on Snakes and Gradient Vector Flow

  • Kwak, Young-Tae
    • Journal of the Korean Data and Information Science Society
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    • v.18 no.2
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    • pp.439-445
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    • 2007
  • GVF can solve two difficulties with Snakes that are on setting initial contour and have a hard time processing into boundary concavities. But GVF takes much longer computation time than the existing Snakes because of their edge map and partial derivatives. Therefore this paper analyzed the computation time between GVF and Snakes. As a simulation result, both algorithms took almost similar computation time in simple image. In real images, GVF took about two times computation than Snakes.

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The Real-time Self-tuning Learning Control based on Evolutionary Computation (진화 연산을 이용한 실시간 자기동조 학습제어)

  • Chang, Sung-Quk;Lee, Jin-Kul
    • Proceedings of the KSME Conference
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    • pp.105-109
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    • 2001
  • This paper discuss the real-time self-tuning learning control based on evolutionary computation, which proves its the superiority in the finding of the optimal solution at the off-line learning method. The individuals are reduced in order to learn the evolutionary strategy in real-time, and new method that guarantee the convergence of evolutionary mutations are proposed. It possible to control the control object varied as time changes. As the state value of the control object is generated, applied evolutionary strategy each sampling time because the learning process of an estimation, selection, mutation in real-time. These algorithms can be applied, the people who do not have knowledge about the technical tuning of dynamic systems could design the controller or problems in which the characteristics of the system dynamics are slightly varied as time changes.

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Real-time small target detection method Using multiple filters and IPP Libraries in Infrared Images

  • Kim, Chul Joong;Kim, Jae Hyup;Jang, Kyung Hyun
    • Journal of the Korea Society of Computer and Information
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    • v.21 no.8
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    • pp.21-28
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    • 2016
  • In this paper, we propose a fast small target detection method using multiple filters, and describe system implementation using IPP libraries. To detect small targets in Infra-Red images, it is mandatory that you should apply a filter to eliminate a background and identify the target information. Moreover, by using a suitable algorithm for the environments and characteristics of the target, the filter must remove the background information while maintaining the target information as possible. For this reason, in the proposed method we have detected small targets by applying multi area(spatial) filters in a low luminous environment. In order to apply the multi spatial filters, the computation time can be increased exponentially in case of the sequential operation. To build this algorithm in real-time systems, we have applied IPP library to secure a software optimization and reduce the computation time. As a result of applying real environments, we have confirmed a detection rate more than 90%, also the computation time of the proposed algorithm have been improved about 90% than a typical sequential computation time.

Real-time Dynamic Simulation Using Multibody Vehicle Model (다물체 차량모델을 이용한 실시간 동역학 시뮬레이션)

  • Choe, Gyu-Jae;No, Gi-Han;Yu, Yeong-Myeon
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.25 no.3
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    • pp.486-494
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    • 2001
  • This paper presents a real-time multibody vehicle dynamic analysis method using recursive Kanes formulation and suspension composite joints. To shorten the computation time of simulation, relative coordinate system is used and the equations of motion are derived using recursive Kanes formulation. Typical suspension systems of vehicles such as MacPherson strut suspension system is modeled by suspension composite joints. The joints are derived and utilized to reduce the computation time of simulation without any degradation of kinematical accuracy of the suspension systems. Using the develop program, a multibody vehicle dynamic model is formed and simulations are performed. Accuracy of the simulation results is compared to the real vehicle field test results. It is found that the simulation results using the proposed method are very accurate and real-time simulation is achieved on a computer with single PowerPC 604 processor.

A study on the extended fixed-point arithmetic computation for MPEG audio data processing (MPEG Audio 데이터 처리를 위한 확장된 고정소수점 연산처리에 관한 연구)

  • 한상원;공진흥
    • Proceedings of the IEEK Conference
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    • pp.250-253
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    • 2000
  • In this paper, we Implement a new arithmetic computation for MPEG audio data to overcome the limitations of real number processing in the fixed-point arithmetics, such as: overheads in processing time and power consumption. We aims at efficiently dealing with real numbers by extending the fixed-point arithmetic manipulation for floating-point numbers in MPEG audio data, and implementing the DSP libraries to support the manipulation and computation of real numbers with the fixed-point resources.

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