• JSTS:Journal of Semiconductor Technology and Science
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• v.14 no.5
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• pp.649-657
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• 2014

In this study, the effects of the frequency-dependent characteristics of through-silicon vias (TSVs) on the performance of 3D ICs are examined by evaluating a typical interconnection structure, which is composed of 32-nm CMOS inverter drivers and receivers connected through TSVs. The frequency-domain model of TSVs is extracted in S-parameter from a 3D electromagnetic (EM) method, where the dimensional variation effect of TSVs can be accurately considered for a comprehensive parameter sweep simulation. A parametric analysis shows that the propagation delay increases with the diameter and height of the TSVs but decreases with the pitch and liner thickness. We also investigate the crosstalk effect between TSVs by testing different signaling conditions. From the simulations, the worst signal integrity is observed when the signal experiences a simultaneously coupled transition in the opposite direction from the aggressor lines. Simulation results for nine-TSV bundles having regular and staggered patterns reveal that the proposed method can characterize TSV-based 3D interconnections of any dimensions and patterns.

• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.1583_1584
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• 2009

Reverberation chamber have become a common tool in radiated susceptibility and emission testing of electronic equipment. In a reverberation chamber, internal electromagnetic fields are mixed by metallic stirrer. Due to elimination of Polarization characteristic in reverberation chamber, electromagnetic wave reached to EUT all aspect angle. Hence, Field distribution in overmode reverberation chamber can be presented by chi-square distribution. Field uniformity in reverberation chamber have to satisfy standard deviation below 3dB and is influenced by mechanical stirrer. This paper investigates relationship between change of stirrer parameter and field uniformity in reverberation chamber.

• KIEE International Transactions on Power Engineering
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• v.5A no.4
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• pp.350-356
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• 2005

Earth equipments are essential to protect humans and other types of equipment from abnormal conditions. Earth resistance and potential must be restricted within a low value. An estimation algorithm of earth parameters and equivalent resistivity is introduced to calculate reliable earth resistance in this research. The proposed algorithm is based on the relationship between apparent resistances and earth parameters. The proposed algorithm, which approximates the non-linear characteristics of earth by using the Artificial Neural Network (ANN), estimates the earth parameters and equivalent resistivity. The effectiveness of the proposed method is verified with case studies.

• Proceedings of the KIEE Conference
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• 2006.07d
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• pp.1787-1788
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• 2006

In this paper, a noisy passive telemetry sensor system using Unscented Kalman Filter (UKF) is proposed. To overcome these trouble problems such as a power limitation and a estimation complexity that the general passive telemetry sensor system including IC chip has, the principle of inductive coupling was applied to the modelling of a passive telemetry sensor system (PTSS) and its noisy capacitive parameter was estimated by the UKF algorithm. Specialty, to show the effective tracking performance of the UKF, we compared with the tracking performance of Recursive Least Square Estimation (RLSE) using linearization

• Proceedings of the KIEE Conference
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• 1994.07a
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• pp.252-254
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• 1994

This paper describes the control method in order that output current of a voltage source inverter tracks reference sinusoidal current so that its harmonic current components are reduced. Operating character of this inverter is analyzed with normalized values of parameter. And the method that apply multilayed feedfoeward neural networks, which play excellent steady state operation in control system, to inverter control system and training method are presented. Then, the output current of inverter which is driven by the proposed method. is considered throughout computer simulation and safe operating range of inverter parameter is resented.

• Proceedings of the KIEE Conference
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• 1997.07f
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• pp.2078-2081
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• 1997

IP speed controller is used as a main controller and it makes the system low overshoot and easy controllability. Load torque is estimated by Kalman filter algorithm and parameter controller is used against a rotor inertia negative variations. Parameter Controller (PC) is equipped with a torque observer implemented by software of a digital signal Processor. PC is a parameter controller which selects a moment of inertia J in responding to a load torque to control the system response.

• Proceedings of the KIEE Conference
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• 1989.07a
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• pp.179-183
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• 1989

This study presents a methodology to choose the optimal parameter of controller by using the performance index sensitivity. The pro-posed method is to select the controller parameter to have the minimum sensitivity. It is shown that the optimal parameter proves the effectiveness in the dynamic stability of power system.

• Journal of IKEEE
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• v.19 no.1
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• pp.33-40
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• 2015

Inverse problem in electrical impedance tomography (EIT) is highly ill-posed therefore prior information is used to mitigate the ill-posedness. Regularization methods are often adopted in solving EIT inverse problem to have satisfactory reconstruction performance. In solving the EIT inverse problem, iterative Gauss-Newton method is generally used due to its accuracy and fast convergence. However, its performance is still suboptimal and mainly depends on the selection of regularization parameter. Although, there are few methods available to determine the regularization parameter such as L-curve method they are sometimes not applicable for all cases. Moreover, regularization parameter is a scalar and it is fixed during iteration process. Therefore, in this paper, a novel method is used to determine the regularization parameter to improve reconstruction performance. Conductivity norm is calculated at each iteration step and it used to obtain the regularization parameter which is a diagonal matrix in this case. The proposed method is applied to human thorax imaging and the reconstruction performance is compared with traditional methods. From numerical results, improved performance of proposed method is seen as compared to conventional methods.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.63 no.4
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• pp.290-294
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• 2014

PID(Proportional, Integral, Derivative) controller is the most popular process controllers in nuclear power plants. The optimized parameter setting of the process controller contributes to the stable operation and the efficiency of the operating nuclear power plants. PID parameter setting is tuned when new process control systems are installed or current process control systems are changed. When the nuclear plant is shut down, a lot of PID tuning methods such as the Trial and Error method, Ultimate Oscillation method operation, Ziegler-Nichols method, frequency method are used to tune the PID values. But inadequate PID parameter setting can be the cause of the unstable process of the operating nuclear power plant. Therefore the results of PID parameter setting should be simulated, optimized and finally verified. This paper introduces the simulation method of PID tuning to optimize the PID parameter setting and confirms them of the actual PID controller in the operating nuclear power plants. The simulation method provides the accurate process modeling and optimized PID parameter setting of the multi-loop control process in particular.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.24 no.8
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• pp.84-93
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• 2010

This paper describes a method of visualization and fast estimation of parameter in continuous time signal. The parameter estimation method of this paper directly estimate the parameters on the basis of the discrete Fourier transform. Also, this paper present to efficient visualization method of dominant parameters obtained in continuous time signal. The proposed methods are applied to test functions with three dominant modes. The results show that the proposed methods are highly applicable to parameter estimation and visualization in continuous time signal.