• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2000.04a
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• pp.141-145
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• 2000

A systematic method to find the optimal blank shape for sheet forming is proposed by coupling the numerical simulation technique. A weighted parameter was introduced in order to simplify the multi-variable optimization problem to a single-variable problem. The proposed method has been applied to the blank design of drawing processes to obtain the near-net shape within the required error bound after forming, Excellent results have been obtained between the numerical results and the target contour shapes. Through the investigation the proposed systematic method for optimal blank design is found to be effective in the practical forming processes

• Communications for Statistical Applications and Methods
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• v.16 no.4
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• pp.707-711
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• 2009

We propose new cointegration tests using signs of the regressors as instrumental variable. Our tests have the asymptotic standard normal distribution and are free from the dimension of regressors under the null hypothesis of no cointegration. A Monte-Carlo simulation shows that the proposed tests have a stable size and an improved power. Particulary, the tests have better power for small numbers of observations.

• 제어로봇시스템학회:학술대회논문집
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• 1987.10b
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• pp.218-222
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• 1987

The continuously variable transmission (C.V.T.) has been introduced for many years, however, the application of C.V.T. system has been used rather restrictively because of the problems such as reliability, durability, efficiency and, controllability. In this paper, some of the research trends about the control algorithms and the system design method involving C.V.T. is introduced. An engine is assumed in operation along the ideal operating line and it is also considered to be controlled independently to the C.V.T. system. The control simulation has been carried out to confirm it and also the operation performance of the system is investigated.

• 제어로봇시스템학회:학술대회논문집
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• 1987.10b
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• pp.566-569
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• 1987

The primary difficulties encountered in the use of step motors are underdamped response when stopping at a specified position and dynamic instability during high-speed slewing. This paper proposes a speed and position detection scheme using the back EMF generated by the rotating permanent magnet field of a two-phase 1.8.deg. hybrid step motor, and presents its application to the state-variable feedback control of the hybrid step motor. All simulation results in a single step response show that the hybrid step motor performances such as peak overshoot and settling time are greatly improved.

• Communications for Statistical Applications and Methods
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• v.8 no.1
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• pp.219-227
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• 2001

Another approach (multi-parameter measurement method) of interlaboratory studies of test methods is presented. When the unrestricted normal likelihood for the fixed latent variable model is unbounded, we propose a me쇙 of restricting the parameter space by formulating realistic alternative hypothesis under which the likelihood is bounded. A simulation study verified the claim of conservatism of level of significance based on assumptions about central chi-square distributed test statistics and on Bonferroni approximations. We showed a randomization approach that furnished empirical significance levels would be better than a Bonferroni adjustment.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.35 no.4
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• pp.156-162
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• 1986

The last few years have seen a rapid development of so-called lattice algorithms for the fast solution of finite date algorithms. So far, most of the work on ladder form has been done for the prewindowed case. In this paper, the covariance lattice algorithm for instrumental variable recusions is presented. This algorithm can be used in various areas of adaptive signal processing, spectral estimation and system identification. The behavior of the proposed algorithm is illustrated by some simulation results for spectral estimation.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.41 no.6
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• pp.625-632
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• 1992

This paper presents a new dc-motor position control approached by Variable Structure System. In order to eliminate a steady-state position error, we propose a switching function composed of position error, velocity, and current ripple. The switching function has an advantage compared to other ones. To determine the control signal voltage, we use a fuzzy logic method. The simulation results show expected performances.

• Journal of the Korea Institute of Military Science and Technology
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• v.6 no.1
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• pp.9-20
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• 2003

In this study, the performance of a semi-active suspension system for heavy duty tracked vehicles has been investigated. To this end, continuous and on-off Sky-Hook control law have been evaluated for a 1/4 car model. Simulation results show that the semi-active suspension system has potential to improve ride quality of the vehicle. And we proposed a method for improving of variable damper performance.

• Proceedings of the KIPE Conference
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• 2020.08a
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• pp.373-374
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• 2020

This paper proposes an optimal control algorithm which determines active damping resistor values considering load variation and grid side current THD. Proposed optimal control algorithm improves grid side current THD of the interlinking converter without passive damping resistor and is verified by simulation under variable load conditions.

• Proceedings of the Korea Society for Simulation Conference
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• 2005.11a
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• pp.102-107
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• 2005

PMS(Plant Monitoring System) for simulation is the program for training that users such as instructor, operator, and supervisor can operate the plant virtually. Presented in this paper, are some lessons learned from implementation of PMS for simulation. First, this PMS fer simulation is based on LINUX instead of UNIX. These two OS(Operating System) have different platform and compiler version on it, so debugging needs to be done about variable defining part. Second, In LINUX system, the size of shared memory and message queue is already designated as a default value that user has to set up and use the RTAP DB. Third, to decrease the dummy data size, it has to be changed into binary formation. Lastly, PMS software for simulation provides several environments according to the command, so considered should be status monitoring, alarm, system organization, point and group monitoring, history storage and searching function.