• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.26 no.6
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• pp.59-65
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• 2012

This paper presents a digital control solution which can extract the reactor parameters in atmosphere plasma power supply. The critical issue of the atmosphere plasma power supply is a impedance matching. For the impedance matching, the reactor parameters should be known, but the parameters depend on the reactors. Therefore, the reactor parameters have to measure for the impedance matching. The proposed method is performed by detection of phase difference between inverter voltage and current, and extraction of impedance through active, reactive power.

• 제어로봇시스템학회:학술대회논문집
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• 1993.10a
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• pp.156-160
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• 1993

This paper presents a controller design to coordinate a robot manipulator under unknown system parameters and bounded disturbance inputs. To control the motion of the manipulator, an inverse dynamics control scheme is applied. Since parameters of the robot manipulators such as mass and inertia are not perfectly known, the difference between the actual and estimated parameters works as a disturbance force. To identify the unknown parameters, an inproved adaptive control algorithm is directly derived from a chosen Lyapunov's function candidate based on the Lyapunov's Second Method. A robust control algorithm is devised to counteract the bounded disturbance inputs such as contact forces and disturbing force coming from the difference between th actual and the estimated system parameters. Numerical examples are shown using three degree-of-freedom planar arm.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.17 no.11
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• pp.1112-1118
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• 2007

It was discussed to identify Thiele Small Parameters for Pseudo loudspeaker within 10mm grade microspeaker attached to closed-box using known dynamic mass of moving parts. Also, enhanced circuit model for vented-box micro speaker system was used to more accurately simulate electrical impedance curves for real vented-box microspeaker system and compared to test results. Consequently, it showed that micro speaker could be modeled by pseudo loudspeaker TS parameters similar to general loudspeaker. Vented-box microspeaker model with pseudo loudspeaker TS parameters was well suited to describe real microspeaker. Also, it was proposed to estimate volume of rear closed-box of microspeaker without design specifications.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 1999.03b
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• pp.84-87
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• 1999

This paper presents a preform design method that combines the analytic method and inference of known knowledge with neural network. The analytic method is a finite element method that is used to simulate backward extrusion with pre-defined process parameters. The multi-layer network and back-propagation algorithm are utilized to learn the training examples from the simulation results. The design procedures are utilized to learn the training examples from the simulation results. The design procedures are two methods the first the neural network infer the deformed shape from the pre-defined processes parameters. The other the network infer the processes parameters from deformed shape. Especially the latest method is very useful to design the preform From the desired feature it is possible to determine the processes parameters such as friction stroke and tooling geometry. The proposed method is useful for shop floor to decide the processes parameters and preform shapes for producing sound product.

• Journal of Korean Institute of Industrial Engineers
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• v.33 no.2
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• pp.166-173
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• 2007

In this paper, we propose a model-based approach to estimating production parameters of semiconductor FAB equipment. For FAB scheduling, for example, we need to know equipment's production parameters such as flow time, tact time, setup time, and down time. However, these data are not available, and they have to be estimated from material move data such as loading times and unloading times that are automatically collected in modern automated semiconductor FAB. The proposed estimation method may be regarded as a Bayes estimation method because we use additional information about the production parameters. Namely, it is assumed that the technical ranges of production parameters are known. The proposed estimation method has been applied to a LCD FAB, and found to be valid and useful.

• 제어로봇시스템학회:학술대회논문집
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• 2000.10a
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• pp.410-410
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• 2000

Impedance control is recognised as one of the most proper control scheme to carry out the assembly tasks, since it can control the dynamic relationship between the manipulator and environment directly. However, it is well known that the contact force cannot be controlled directly using the impedance control. Also impedance parameters should be properly defined depending on the task to be performed. We propose a new position based impedance control, which has self-adjusted impedance parameters and can control the contact force explicitly, Impedance parameters, as time-varying parameters, are adjusted automatically based on the measured contact force and the position error during the task. A proposed algorithm was implemented on the peg-in-hole task with the industrial manipulator. We shows the effectiveness of proposed control method experimentally.

• Journal of Environmental Science International
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• v.12 no.10
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• pp.1109-1116
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• 2003

The genetic algorithm is investigated fer parameters estimation of SED (storage - effective drainage) model from the Wi-stream watershed in Nakdong river basin. In the practical application of model, as a number of watershed parameters do not measure directly, it is desirable to make a good estimation from the known rainfall and runoff data. For the estimation of parameters of the SED model using the genetic algorithm, parameters of Green-Ampt equation(SM, K$\_$s/) for the estimation of an effective rainfall and initial storage(y$\_$in/) used in SED model are obtained a regression equation with 5, 10, 20 days antecedent precipitation. And as a consequence of computation, the parameters were obtained to satisfy the proposed objective function. From the comparison of observed and computed hydrographs, it shows a good agreement in the shape and the rising limb, peak, falling limb of hydrograph, so the SED model using the genetic algorithm shows a suitable model for runoff analysis in river basin.

• Journal of Applied Reliability
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• v.11 no.3
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• pp.225-234
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• 2011

In the fields of reliability application, the most commonly used test methods for reliability qualification are zero-failure acceptance tests since they require fewer test samples and less test time compared to other test methods that guarantee the same reliability with a given confidence level. Usually values of shape parameters are assumed to be known in designing reliability qualification tests for Weibull lifetime distribution. It is important to select correct values of shape parameters to guarantee the specified reliability with given confidence level exactly. The effect of using wrong values of shape parameters in designing reliability qualification test for products with Weibull lifetime distribution is examined and selecting proper values of shape parameters for conservative reliability qualification is discussed.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.4 no.4
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• pp.895-899
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• 2000

A method of measuring Q of a two port cavity by scattering parameters is proposed. The scattering parameters of a two port cavity resonator are derived by a lumped equivalent circuit model as a function of cavity parameters, including the cavity Q. These can be also obtained by direct measurement with a modern network analyzer, The results show good agreement with those from other well-known methods. This two port measurement can provide additional information such as the coupled power ratio, which is one of the important parameters for the beam accelerating cavities.

• Journal of the Korean Society for Precision Engineering
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• v.17 no.1
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• pp.27-33
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• 2000

This paper presents a method for determining machining parameters in 3-dimentional electrical discharge machining(EDM). The parameters are the peak value of currents, the pulse-on time, and the pulse-off time. It is known that they influence the performance of EDM more than the other else. The parameters are determined from the discharge area between a tool electrode and a work piece. The discharge area is directly influenced by the geometry of a tool surface and the tool discharge position. The discharge area on a tool discharge position is calculated from intersection curves between the tool surface and a horizontal plane. The grid search method is applied to determine the intersection curves. An example is introduced to show that the machining parameters are obtained from the surface geometry of a tool electrode.