• Proceedings of the IEEK Conference
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• 1999.06a
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• pp.319-322
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• 1999

In this paper, we report characteristics of a internal chip of LiNbO$_3$ modulator with low-driving-voltage at 150nm wavelength. A Ti diffusion method for LiNbO$_3$ optical waveguide and a buffer layer for improving phase velocity mismatch between optical and microwave waves were employed. The traveling-wave coplanar waveguide electrode of 35mm is used for reducing the driving voltage. From this work, wideband modulation of 10㎓ and low-driving voltage of 3.9volts are realized.

• Proceedings of the IEEK Conference
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• 1999.11a
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• pp.1057-1060
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• 1999

For efficient storage and retrieval of large video data sets, automatic video scene change detection is a necessary tool. Video scene changes fall into two categories, namely fast and gradual scene changes. The gradual scene change effects include, dissolves, wipes, fades, etc. Although currently existing algorithms are able to detect fast scene changes quite accurately, the detection of gradual scene changes continue to remain a difficult problem. In this paper, among various gradual scene changes, we focus on dissolves. The algorithm uses a subset of the entire video, namely the sequence of DC images, for improvement of detection velocity

• Proceedings of the IEEK Conference
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• 1999.11a
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• pp.464-467
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• 1999

Usually, more reference signatures result in better performance in signature verification. However, registering .many signatures may be a tedious work for users, so algorithms that use less signatures for the registration without increasing error rate is needed. In this paper, we find the features such as pen-down duration, the number of locally minimum velocity points, and the number of locally maximum curvature points. Then we find the relationship between these features and the optimal decision boundary. We apply this relationship in deciding threshold for signature verification. Experimental results show that the method using three reference signatures has almost same error rate as algorithms with many references.

• Proceedings of the IEEK Conference
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• 2000.11c
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• pp.149-152
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• 2000

We propose simple analog MOS circuits producing the one-dimensional compact motion-sensing circuits. In the proposed circuit, the optical flow is computed by a number of local motion sensors which are based on biological motion detectors. Mimicking the structure of biological motion detectors made the circuit structure quite simple, compared with conventional velocity sensing circuits. Extensive simulation results by a simulation program of integrated circuit emphasis (SPICE) indicated that the proposed circuits could compute local velocities of a moving light spot and showed direction selectivity for the moving spot

• Journal of the Korean Institute of Telematics and Electronics D
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• v.35D no.2
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• pp.40-51
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• 1998

Electron transport properties are investigated by Monte Carlo simulation in n-HgCdTe. The material is easily degenerated at low temperature or being slightly doped, and is characterized by small band gap and large nonparabolic factor. The degeneracy is incorporated in the Monte Carlo simulation by taking into account the electron-electron scattering and the pauli exclusion principle. In the conventional method, however, the electron-electron scattering rate was developed under the assumption of parabolic conduction band. A new formulation of the electron-electron scattering rate is develop considering the band nonparabolicity and overlap integral. The electron-electron scattering effects on the electron distribution,impact ionization coefficienty, electron temperature, drift velocity and electron energy are presented.

• Journal of the Korean Institute of Telematics and Electronics B
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• v.32B no.7
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• pp.1010-1024
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• 1995

An intelligent trajectory control method that controls a direction and a average velocity for a prosthetic arm by force and direction estimations using EMG signals is proposed. 3 stage linear filters are used as a real time joint trajectory planner to minimize the impact to human body induced by arm motions and to reduce muscle fatigues. We use combination of MLP and fuzzy filter for a limb direction estimation and a time model of force for determining a cartesian trajectory control parameter. EMG signals are acquired by using a amputation simulator and 2 dimensional joystick motion. Simulation results of the proposed method show that the arm is effectively followed the desired trajectory by estimated foreces and directions. This method reduces the number of electrodes and attatched sites compared with the method using Hogan's impedance control.

• Journal of the Korean Institute of Telematics and Electronics B
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• v.31B no.9
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• pp.150-158
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• 1994

In this paepr, Fuzzy Constraint Line Clustering (FCLC) method for optical flow estimation is proposed. FCLC represents the spatical and temporal gradients as fuzzy sets. Based on these sets, several constraint lines with different membership values are generated for the poxed whose velocity is to be estimated. We describe the process for obtaining the membership values of the spatial and temporal gradients and that of the corresponding constraint line. We also show the process for deciding the tightest cluster of point formalated by intersection between constraint lines. For the synthetic and real images, the results of FCLC are compared with of CLC.

• Journal of the Korean Institute of Telematics and Electronics B
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• v.31B no.10
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• pp.44-52
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• 1994

In this paper, we assume that the dynamics of DC motor and nonlinear load are unknown. We propose an inverse dynamic model of DC motor and nonlinear load using the artificial neural network and construck speed control system based on the proposed dynamic model. We also propose another dynamic model with speed prediction scheme using the artificial neural network that removes the undesirable time delay effect caused by the computation time during the real-time control. We suggest a dynamic model which has arbitrary number of speed arguments and is especially effective when the motor and load has large moment of inertia. Next, we suggest a controller that combine the neurocontrol and PID control with constant gain. We show that the proposed neurocontrol systems have capabilities of noise rejection and generalization to have good velocity tracking through computer simulations and experiments.

• Proceedings of the KSR Conference
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• 2000.11a
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• pp.271-281
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• 2000

A number of variables and environment are concerned for the basic design of train. The design of train ran be optimized by the ruining simulation. And using the simulation result the consuming energy, regenerating power, adhesion coefficient, train traction control capacity are respectable. Considering these variables and for more information operating time, operating period, standard velocity and limit speed, the all factors of train are optimized. The light-tail tram is mainly divided into linear motor train, road surface train, iron wheel train and rubber tire train, and the most profitable one for adhesion coefficient is rubber tire train and the train will be designed.

• Proceedings of the KSR Conference
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• 2007.05a
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• pp.387-394
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• 2007

This study area located in HoNam High-Speed railway soft ground section. So it carried out the boring survey, field survey and test of laboratory. It collected the engineering data of ground and the data for the establishment arrangement. The investigation did a soil investigation in Nonsan. The investigation item excuted seismic piezocone penetration test, s-wave seismic refraction survey, ps logging test, density logging test which is a physical exploration and boring. Eventually, results of geotechnical and shear-wave survey are useful for ground information in soft ground that has identified the characteristics of geological responses and elastic modulus.