• The Transactions of The Korean Institute of Electrical Engineers
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• v.61 no.2
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• pp.324-328
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• 2012

A recovered jitter of CDR(Clock and Data Recovery) Circuit based on Dual-loop DLL(Delay Locked Loop) for data recovery in high speed serial data communication is changed by depending on the input data and reference clock frequency. In this paper, 2-step DPC which has constant jitter performance for wide-range input frequency is proposed. The designed prototype 2-step CDR using proposed 2-step DPC has operation frequency between 200Mbps and 4Gbps. Average delay step of 2-step DPC is 10ps. Designed CDR circuit was tested with 0.18um CMOS process.

• Proceedings of the KIEE Conference
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• 1994.07a
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• pp.556-558
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• 1994

This paper proposes a new converter that can reduce the harmonics like conventional 12-pulse dual thyrister converters with the input transformers. Both the bridges are controlled with the shifted firing angle and connected through current sharing reactors. Using the center tapped reactor, the DC link current is controlled with the different two values in order to make the input current waveform 12 pulses.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.39A no.12
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• pp.774-776
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• 2014

In this paper, we propose a multiple dual-polarized antenna system for multi-user transmission in line-of-sight (LoS) dominant channel environments. By exploiting space and polarization resources efficiently, the proposed system achieves a higher sum rate than the existing multi-user multiple input multiple output (MU-MIMO) system with uni-polarized antennas.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.63 no.4
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• pp.509-518
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• 2014

Though various techniques have been studied as a way of adjusting parameters of PID controllers, no perfect method of determining parameters is available to date. Especially the deign of PID controller for unstable processes with dead time(UPWDT) is even more difficult due to various reasons. Generally the existing design procedures for UPWDT involve deriving formulas to meet gain and phase margin specifications, or using inner loop to stabilize UPWDT before applying PID controller. In this paper, the dual-input describing function(DIDF) method is proposed, by which the performance and robustness of the closed-loop system can be improved. The method is based on moving the critical point (-1+j0) of Nyquist stability to a new position arbitrarily selected on the complex plane. This can be done by determining appropriate coefficients of the DIDF. As a result, we can easily determine parameters of PID-type controller by using existing conventional tuning methods for stable or unstable systems. Simulation results are included to show the effectiveness of the proposed method.

• The Transactions of the Korean Institute of Power Electronics
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• v.18 no.6
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• pp.515-522
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• 2013

In this paper, a new PCS is proposed which is consisted of high boost dual converter and single phase half-bridge inverter. The proposed PCS is configured in parallel input / serial output, using two interleaved voltage doubler converter. Converter of the proposed PCS is distribute input current by configuring parallel input and reduced turn ratio of transformer by configuring serial output. Also, compositions of the inverter are composed of serial output capacitor of converter and half-bridge inverter. The dual converter and single phase half-bridge inverter is designed and characteristic of the new PCS is analysed. The system of the 1.5[kW] PCS is verified through an experimental about operation and stability.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.51 no.7
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• pp.362-370
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• 2002

This paper describes the practical tuning method of dual-input PSS and its application to Muju P/P #2 with Proto PSS, which is based on DSP technology and uses both frequency and power. First, the model parameters of generator system used in this paper have been derived from the generator characteristic testing. Then, in the selection of PSS parameters, the Bode plot is plotted in order to tune the PSS's time constants which are able to compensate the phase lagging due to generator and excitation system. In addition, the eigenvalue analysis is also performed for determining a reliable PSS gain, $K_{s}$. Finally, the transient stability program has been utilized to verify the safe operation of Proto PSS against the predictable disturbances such as the AVR-step test and generator unloading test. In on-site test, the simulated results have been identically duplicated by implementing AVR step test in Muju P/P #2 with Proto PSS, which has the previously designed PSS parameters.s.

• 한국정보통신설비학회:학술대회논문집
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• 2007.08a
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• pp.432-435
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• 2007

In this paper, a dual band microstrip patch Antenna is designed for RFID Application. The antenna shows a good performance at the frequencies, 900MHz and 2.45GHz for the radiation characteristics and input impedance matching, as well. The reflection factor is lower than -25dB and a good directivity higher than 5dB is achieved for both frequency.

• Proceedings of the IEEK Conference
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• 2001.06b
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• pp.57-60
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• 2001

A readout circuit for Dual band IR detector was proposed and designed. Designed circuit provide to detector a stable diode bias and high injection efficiency using Buffered Direct Injection (BDI) input circuit. Then, amplifier in the unit cell is operated when cell is selected in order to minimize the power consumption. We could confirm through the simulation that designed circuit integrate and output simultaneously the signal generating from the dual band IR detector.

• Proceedings of the KIEE Conference
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• 2001.07d
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• pp.2277-2279
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• 2001

This paper describes a vision-based steering control method for AGV which use dual motor drive. We suggest an algorithm which can be detect the guideline quickly and exactly for real time vision processing, and control the steering through an assign the CP (Control - Point) of input image. This method is tested via a IAGV which dual motor drive with a single camera in laboratory environment.

• East Asian mathematical journal
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• v.38 no.5
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• pp.603-610
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• 2022

In [6, 7] they introduced a new finite element method for accurate numerical solutions of Poisson equations with corner singularities. They consider the Poisson equations with homogeneous boundary conditions, compute the finite element solutions using standard FEM and use the extraction formula to compute the stress intensity factor(s), then they posed new PDE with a regular solution by imposing the nonhomogeneous boundary condition using the computed stress intensity factor(s), which converges with optimal speed. From the solution they could get an accurate solution just by adding the singular part. They considered a partial differential equation with the input function f ∈ L²(Ω). In this paper we consider a PDE with the input function f ∈ H¹(Ω) and find the corresponding singular and dual singular functions. We also induce the corresponding extraction formula which are the basic element for the approach.