• Title/Summary/Keyword: stopping point

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Efficient Strategies to Verify VHDL Model (VHDL 모델의 효율적인 검증 방법)

  • 김강철
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2003.05a
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    • pp.526-529
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    • 2003
  • This paper presents two strategies to refute clock cycles when using stopping rule in VHDL model verification. The first method is that a semi-random variable is defined and the data that stay in the range of semi-random variable are skipped when stopping rule is running. The second one is to keep the old values of parameters when phases are changed. 12 VHDL models are examined to observe the effectiveness of strategies.

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Efficient Methods for Reducing Clock Cycles in VHDL Model Verification (VHDL 모델 검증의 효율적인 시간단축 방법)

  • Kim, Kang-Chul
    • Journal of the Institute of Electronics Engineers of Korea SD
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    • v.40 no.12
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    • pp.39-45
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    • 2003
  • Design verification of VHDL models is getting difficult and has become a critical and time-consuming process in hardware design. Recent]y the methods using Bayesian estimation and stopping rule have been introduced to verify behavioral models and to reduce clock cycles. This paper presents two strategies to reduce clock cycles when using stopping rule in a VHDL model verification. The first method is that a semi-random variable is defined and the data that stay in the range of semi-random variable are skipped when stopping rule is running. The second one is to keep the old values of parameters when phases of stopping rule are changed. 12 VHDL models are examined to observe the effectiveness of strategies, and the simulation results show that more than about 25% of clock cycles is reduced by using the two proposed strategies with 0.6% losses of branch coverage rate.

A study on the estimation of impact velocity of crashed vehicles in tunnel using computer simulation(PC-CRASH) (컴퓨터 시뮬레이션(PC-CRASH)을 이용한 터널 내 피추돌 차량의 충돌 속도 추정에 관한 연구)

  • Han, Chang-Pyoung;Choi, Hong-Ju
    • Design & Manufacturing
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    • v.14 no.4
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    • pp.40-45
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    • 2020
  • In a vehicle-to-vehicle accident, the impact posture, braking status, final stopping position, collision point and collision speed are important factors for accident reconstruction. In particular, the speed of collision is the most important issue. In this study, the collision speed and the final stopping position in the tunnel were estimated using PC-CRASH, a vehicle crash analysis program used for traffic accident analysis, and the final stopping position of the simulation and the final stopping position of the traffic accident report were compared. When the Pride speed was 0km/h or 30km/h and the Sorento speed was 100m/h, the simulation results and reports matched the final stopping positions and posture of the two vehicles. As a result of the simulation, it can be estimated that Pride was collided in an almost stationary state.

A Study on the precious stopping control for the automatic electric rail cars (도시철도 전차의 정위치 정차 제어에 관한 연구)

  • Park, Mun-Gyu;Kim, Gyu-Sik
    • Proceedings of the KIEE Conference
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    • 2006.04a
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    • pp.228-230
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    • 2006
  • While trains perform a complete precision stopping control at stop point, it is essential to keep better commuters comfort in prompt. Because a train's brake force tends to increase a brake effort in a low speed and a low brake effort, a brake force in motor cars must be increased to keep better passenger comfort, to control the special braking qua1ities and to prevent the impact of the automatic coupler rather than trailer's, Rail cars must have a special braking process for the train stopping control. In the train stop mode, the train stopping control is designed to start at 20km/h. It starts by Dynamic brake blending, and then finally stops by only the friction. If these process are not exactly activated, the train may fail a complete precision stop. In this report, it studied the electric and friction brake processing during the precious stopping control. To achieve exact test results, the speed reference has to be reduced the calculated difference. In the precision stopping control. the ways of the keeping brake force in motor car was analyzed and some solutions of controling air pressure was brought up by means of direct test in main line, This study was based on line 5 in Seoul Metropolitan subway.

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A Bayesian Diagnostic Measure and Stopping Rule for Detecting Influential Observations in Discriminant Analysis

  • Kim, Myung-Cheol;Kim, Hea-Jung
    • Journal of the Korean Statistical Society
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    • v.29 no.3
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    • pp.337-350
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    • 2000
  • This paper suggests a new diagnostic measure and a stopping rule for detecting influential observations in multiple discriminant analysis (MDA). It is developed from a Bayesian point of view using a default Bayes factor obtained from the fractional Bayes factor methodology. The Bayes factor is taken as a discriminatory information in MDA. It is shown that the effect of an observation over the discriminatory information is fully explained by the diagnostic measure. Based on the measure, we suggest a stopping rule for detecting influential observations in a given training sample. As a tool for interpreting the measure a graphical method is sued. Performance of the method is used. Performance of the method is examined through two illustrative examples.

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Optimal stopping in sampling from a multivariate distribution

  • Jorn, Hong-Suk;Chung, Han-Young
    • Journal of the Korean Operations Research and Management Science Society
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    • v.1 no.1
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    • pp.147-150
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    • 1976
  • Optimal stopping problem without recall from a multivariate distribution is solved by using the concept of an equilibrium point which was introduced by J. Nash. The solution is derived for the two cases: 1. The case where the observation cost C is positive and the given upper bound K on the number of observations is infinite. 2. The case where the observation cost C is zero and the given upper bound K on the number of observations is finite.

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Computational enhancement to the augmented lagrange multiplier method for the constrained nonlinear optimization problems (구속조건식이 있는 비선형 최적화 문제를 위한 ALM방법의 성능향상)

  • 김민수;김한성;최동훈
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.15 no.2
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    • pp.544-556
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    • 1991
  • The optimization of many engineering design problems requires a nonlinear programming algorithm that is robust and efficient. A general-purpose nonlinear optimization program IDOL (Interactive Design Optimization Library) is developed based on the Augmented Lagrange Mulitiplier (ALM) method. The ideas of selecting a good initial design point, using resonable initial values for Lagrange multipliers, constraints scaling, descent vector restarting, and dynamic stopping criterion are employed for computational enhancement to the ALM method. A descent vector is determined by using the Broydon-Fletcher-Goldfarb-Shanno (BFGS) method. For line search, the Incremental-Search method is first used to find bounds on the solution, then the bounds are reduced by the Golden Section method, and finally a cubic polynomial approximation technique is applied to locate the next design point. Seven typical test problems are solved to show IDOL efficient and robust.

Some Properties of Sequential Point Estimation of the Mean

  • Choi, Ki-Heon
    • Journal of the Korean Data and Information Science Society
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    • v.16 no.3
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    • pp.657-663
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    • 2005
  • Under the minimum risk point estimation formulation of Robbins(1959), we consider the sequential point estimation problem for normal population $N({\theta},\;{\theta})$ with unknown parameter ${\theta}$. In the case of completely unknown ${\theta}$, Stein's(1945) two-stage procedure is known to enjoy the consistency property, but it is not even first-order efficient. In the case when ${\theta}>{\theta}_L\;where\;{\theta}_L(>0)$ is known, the revised two-stage procedure is shown to enjoy all the usual second-order properties.

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Capturing and Modeling of Driving Skills Under a Three Dimensional Virtual Reality System Based on Hybrid System

  • Kim, Jong-Hae;Hayakawa, Soichiro;Suzuki, Tatsuya;Hirana, Kazuaki;Matsui, Yoshimichi;Okuma, Shigeru;Tsuchida, Nuio
    • 제어로봇시스템학회:학술대회논문집
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    • 2003.10a
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    • pp.2747-2752
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    • 2003
  • This paper has develops a new framework to understand the human’s driving maneuver based on the expression as HDS focusing on the driver’s stopping maneuver. The driving data has been collected by using the three-dimensional driving simulator based on CAVE, which provides three-dimensional visual information. In our modeling, the relationship between the measured information such as distance to the stop line, its first and second derivatives and the braking amount has been expressed by the PWPS model, which is a class of HDS. The key idea to solve the identification problem was to formulate the problem as the MILP with replacing the switching conditions by binary variables. From the obtained results, it is found that the driver appropriately switches the ‘control law’ according to the following scenario: At the beginning of the stopping behavior (just after finding the stopping point), the driver decelerate the vehicle based on the acceleration information, and then switch to the control law based on the distance to the stop line.

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