• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 학술대회 논문집 정보 및 제어부문
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• pp.415-417
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• 2005

This paper proposes tracking control method using pseudo-backstepping control for wheeled mobile robots with nonholonomic constraints. First, the pseudo commands for forward linear velocity and angular velocity are chosen based on the kinematics. Then, the actual torque control inputs are designed to make the actual forward linear velocity and angular velocity follow the pseudo commands. Both semi-global practical posture(position and heading direction angle) stabilization and trajectory tracking are achieved for reference trajectories such as straight line and sinusoidal curve. The stability and performance analysed and numerical simulations are performed to confirm the effectiveness of the proposed scheme.

• Geomechanics and Engineering
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• 제17권2호
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• pp.207-214
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• 2019

Dams have a great importance on energy and irrigation. Dams must be evaluated statically and dynamically even after construction. For this purpose, Torul dam built between years 2000 and 2007 Harsit River in Gümüşhane province, Turkey, is selected as an application. The Torul dam has 137 m height and 322 GWh annual energy production capacity. Torul dam is a kind of concrete face rock fill dam (CFRD). In this study, static and pseudo seismic stability of Torul dam was investigated using finite element method. Torul dam model is constituted by numerical stress analysis named Phase2 which is based on finite element method. The dam was examined under 11 different water filling levels. Thirteenth stage of the numerical model is corresponding full reservoir condition which water filled up under crest line. Besides, pseudo static coefficients for dynamic condition applied to the dam in fourteenth stage of the model. Stability assessment of the Torul dam has been discussed according to the displacement throughout the dam body. For static and pseudo seismic cases, the displacements in the dam body have been compared. The total displacements of the dam according to its the empty state increase dramatically at the height of the water level of about 70 m and above. Compared to the pseudo-seismic analysis, the displacement of dam at the full reservoir condition is approximately two times as high as static analysis.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1999년도 제14차 학술회의논문집
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• pp.309-312
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• 1999

This paper proposed a novel method for pseudo-on-line scheme using look-up table based on the genetic algorithm The technique is an pseudo-on-line method that optimally estimate the parameters of FPID controller for systems with non-linearity using the genetic algorithm which does not use the gradient and finds the global optimum of an unconstraint optimization problem. The proposed controller is applied to speed control of 3-phase induction motor and its computer simulation is carried out. Simulation results show that the proposed method is more excellent then conventional FPID and PID controllers.

• JSTS:Journal of Semiconductor Technology and Science
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• 제15권5호
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• pp.455-462
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• 2015

H-field EMI measurements have been performed for the single-ended, the differential, and the pseudo-differential signaling on a 11" FR4 microstrip line. The pseudo-differential signaling reduces EMI by more than 10 dB compared to the single-ended signaling if the delay mismatch is lower than 5% of a period for a 3 GHz clock signal. Empirical H-field equations for both differential and single-ended signaling showed fair agreements with measurements.

• 대한기계학회논문집A
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• 제28권1호
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• pp.70-78
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• 2004

This paper presents study of efficiency of wavelet transformation for on-line chatter detection during hard fuming process. From comparison with other time series and statistical methods such as fast fourier transformation (FFT), Kurtosis and standard deviation (STD), wavelet transform is better than others in on-line chatter detection. With using wavelet function with pseudo frequency corresponding to chatter frequency, chatter could be detected more sensitively. And for both force signal from dynamometer and displacement signal from capacitance type cylindrical sensor (CCS), wavelet transform with DB2 function on level 4 could be well used for chatter detection in hard turning process.

• 한국유체기계학회 논문집
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• 제6권1호
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• pp.44-50
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• 2003

Flow through a turbine flow meter is simulated by solving the incompressible Navier-Stokes equations. The solution method is based on the pseudo-compressibility approach and uses an implicit-upwind differencing scheme together with the Gauss-Seidel line relaxation method. The equations are solved steadily in rotating reference frames, and the centrifugal force and the Coriolis force are added to the equation of motion. The standard $k-{\epsilon}$model is employed to evaluate turbulent viscosity. Computational results yield quantitative as well as qualitative information on the design of turbine flow meters by showing the distributions of pressure and velocity around the turbine blades.

• 한국음향학회지
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• 제20권1호
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• pp.62-67
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• 2001

직선집속 PVDF 초음파 트랜스듀서를 이용하여 누설탄성표면파 (Leaky Surface Acoustic Wave: LSAW)의 전파속도를 측정하고, 그 결과를 이론해석 결과와 비교하였다. 시료로는 등방성 재료인 구리, 알루미늄 및 용융석영, 이방성 재료인 Z-cut α/sup-/수정을 사용하였다. 측정방법으로는 초점면에 위치한 시료를 트랜스듀서 쪽으로 접근시켰을 때 LSAW가 트랜스듀서의 중심축을 통과한 후 시료표면에서 직접 반사되어오는 종파와 분리되어지는 현상을 이용하였다. 음속의 측정결과는 이론 해석결과와 오차 1％이내에서 잘 일치하였으며,α/sup-/수정의 (0,0,1)면에서는 LSAW 외에 의사누설탄성표면파 (Leaky Pseudo Surface Acoustic Wave : LPSAW)가 전형적인 6-fold 이방성을 가지고 전파됨을 알 수 있었다.

• 한국해양공학회지
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• 제19권5호
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• pp.71-77
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• 2005

This paper presents an integrated underwater navigational algorithm for unmanned underwater vehicles, using additional two-range transducers. This paper proposes a measurement model, using two range measurements, to improve the performance of an IMU-DVL (inertial measurement unit - Doppler velocity log) navigation system for long-time operation of underwater vehicles, excluding DVL measurement. Extended Kalman filter was adopted to propagate the error covariance, to update the measurement errors, and to correct the state equation when the external measurements are available. Simulation was conducted with the 6-d.o.f nonlinear numerical model of an AUV in lawn-mowing survey mode, at current flaw, where the velocity information is unavailable. Simulations illustrate the effectiveness of the integrated navigation system, assisted by the additional range measurements without DVL sensing.

• 제어로봇시스템학회논문지
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• 제13권9호
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• pp.896-902
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• 2007

This paper proposes a vision-based kinematic control method for mobile robots with camera-on-board. In the previous literature on the control of mobile robots using camera vision information, the forward velocity is set to be a constant, and only the rotational velocity of the robot is controlled. More efficient motion, however, is needed by controlling the forward velocity, depending on the position in the corridor. Thus, both forward and rotational velocities are controlled in the proposed method such that the mobile robots can move faster when the comer of the corridor is far away, and it slows down as it approaches the dead end of the corridor. In this way, the smooth turning motion along the corridor is possible. To this end, visual information using the camera is used to obtain the perspective lines and the distance from the current robot position to the dead end. Then, the vanishing point and the pseudo desired position are obtained, and the forward and rotational velocities are controlled by the LOS(Line Of Sight) guidance law. Both numerical and experimental results are included to demonstrate the validity of the proposed method.

• 한국원자력학회:학술대회논문집
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• 한국원자력학회 1996년도 춘계학술발표회논문집(1)
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• pp.459-464
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• 1996

The 3-D power distribution synthesis scheme was implemented in Totally Integrated Core Operation Monitoring System (TICOMS), which is under development as the next generation core monitoring system. The on-line 3-D core power distribution obtained from the measured fixed incore detector readings is used to construct the hot pin power as well as the core average axial power distribution. The core average axial power distribution and the hot pin power of TICOMS were compared with those of the current digital on-line core monitoring system, COLSS, which construct the core average axial power distribution and the pseudo hot pin power. The comparison shows that TICOMS results in the slightly more accurate core average axial power distribution and the less conservative hot pin power. Therefore, these results increased the core operating margins. In addition, the on-line 3-D power distribution is expected to be very useful for the core operation in the future.