• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1998.11a
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• pp.137-140
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• 1998

An active-matrix LCD using thin film transistors (TFT) has been widely recognized as having potential for high-quality color flat-panel displays. Pixel-Design Array Simulation Tool (PDAST) was used to profoundly understand the gate si후미 distortion and pixel charging capability. which are the most critical limiting factors for high-quality TFT-LCDs. Since PDAST can simulate the gate, data and pixel voltages of a certain pixel on TFT array at any time and at any location on an array, the effect of the resistivity of gate line material on the pixel operations can be effectively analyzed. The gate signal delay, pixel charging ratio and level-shift of the pixel voltage were simulated with varying the parameters. The information obtained from this study could be utilized to design the larger area and finer image quality panel.

• 한국정보디스플레이학회:학술대회논문집
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• 2008.10a
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• pp.408-411
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• 2008

In an attempt to enhance luminance efficiency and to reduce discharge delays of test panels with aluminum fence-electrodes, various designs of the electrodes were prepared by chemically etching the aluminum foils bonded to soda-lime glass substrate via anodic bonding process. The effects of fence design on luminance and discharge characteristics were investigated and compared with conventional ac-PDPs. These results showed a possibility of using fence-type aluminum electrode at front plates of ac-PDDs without sacrificing its performance.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.7 no.3
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• pp.411-416
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• 2003

In this paper, We analysed performance of adaptive modulation system with STTD. Transmission error of system is increased by ISI according to delay wave in wireless channel environment. Therefore, We analysed performance that it is applied adaptive modulation system with STTD to reduce ISI's effect. As a results, Data transmission of high speedㆍhigh quality could know possible by applying adaptive modulation system with STTD. Because of selected high modulation mode in low SNR.

• Proceedings of the KIEE Conference
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• 1989.07a
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• pp.129-133
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• 1989

In this paper, a robust controller of state delayed systems is presented. The suggested controller stabilizes the closed loop system independently of the delay time. It is shown that the controller reduces the effect of disturbances on the output of the given system to a pre-specified level. The proposed controller will stabilize the closed loop system in the presence of plant perturbations whose size are less than a pre-specified value.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.49 no.2
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• pp.123-129
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• 2000

This paper proposes a novel current control method of three-phase PWM rectifiers using estimated currents without phase current sensors. The phase currents are reconstructed from switching states of the rectifier and the measured dc output currents. To eliminate the calculation time delay effect of the microprosessor, the current at the next sampling instant are predicted by a predictive state observer and then are used for feedback control. Experimental results show that the control performance of the proposed system is almost the same as that of the phase current sensor-based system.

• Proceedings of the KIEE Conference
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• 2005.10b
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• pp.315-318
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• 2005

This paper characterizes the performance for a remote path tracking control of the mobile robot in IP network viamiddleware. The middleware is used to alleviate the effect of the delay time on a mobile robot path tracking in Network-Based Control environment. The middleware also can be implemented in a modular structure. Thus, a controller upgrade or modification for other types of network protocols or different control objectives can be achieved easily. A case study on a mobile robot path-tracking with IP network delays is described. The effectiveness of the proposed approach is verified by experimental results.

• Journal of the Korean Institute of Telematics and Electronics
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• v.25 no.1
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• pp.101-107
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• 1988

This paper proposes a circuit extractor which extracts a netlist from the CIF input file cntaining the layout mask artwork informations. The circuit extractor extracts transistors and their interconnections, and calculates circuit parameter such as parasitic resistance and parasitic capacitance from the mask informations. When calculating the parasitic resistance, we consider the current flow path to reduce the errors caused by the resistance approximation. Similarly, we consider the coupling capacitance which has an effect on the circuit characteristics, when the parasitic capacitances are calculated. Therefore, using these parameter values as an input to circuit simulation, the circuit characteristics such as delay time can be estimated accurately. The presented circuit extraction algorithm uses a multiple storage quad tree as a data sturucture for storing and searching the 2-dimensional geometric data of mask artwork. Also, the proposed algorithm is technologically independent to work across a wide range of MOS technologies without any change in the algorihm.

• Journal of the Korean Society for Nondestructive Testing
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• v.28 no.2
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• pp.199-204
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• 2008

The generation of axisymmetric Lamb waves and interaction with wall thinning (corrosion) defects in hollow cylinders are simulated using the finite element method. Guided wave interaction with defects in cylinders is challenged by the multi-mode dispersion and the mode conversion. In this paper, two longitudinal, axisymmetric modes are generated using the concept of a time-delay periodic ring arrays (TDPRA), which makes use of the constructive/destructive interference concept to achieve the unidirectional emission and reception of guided waves. The axisymmetric scattering by the wall thinning extending in full circumference of a cylinder is studied with a two-dimensional FE simulation. The effect of wall thinning depth, axial extension, and the edge shape on the reflections of guided waves is discussed.

• Journal of the Korean Institute of Telematics and Electronics C
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• v.35C no.5
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• pp.1-10
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• 1998

In this paper, a new hardware-software patitioning algorithm is presented, in which the system behavioral description containing a mixture of hardware and softwae components is partitioned into the hardware part and the software part. In this research, new techniques to optimally partition a mixed system under certain specified constaints such as performance, area, and delay, have been developed. During the partitioning process, the overhead due to the communication between the hardware and software parts are considered. New featues have been added to adjust the hierarchical level of partitioning. Power consumption, memory cost, and the effect of pipelining can also be considered during partitioning. Another new feature is the ability to partition a DSP system under throughput constraints. This feature is important for real time processing. The developed partitioning system can also be used to evaluate various design alternatives and architectures.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.12 no.7
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• pp.632-641
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• 2000

The present study concerns the simulation of supply-air control in a variable air volume (VAV) system. A stratified lumped thermal model (multi-zone model) is suggested to predict local thermal response of an air-conditioned space. The effects of various thermal parameters such as the cooling system capacity, the thermal mass of air-conditioned space, the time delay of thermal effect, and the building envelope heat transmission are investigated in detail. Further, the influence of control parameters, PI control factor and the sensor location on a VAV system is quantitatively delineated. The results obtained show that the previous homogeneous lumped thermal model (1-zone model) may predict a significantly different thermal response in the air-conditioned space according to the sensor location.