• Journal of the Institute of Electronics Engineers of Korea TC
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• v.40 no.2
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• pp.47-55
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• 2003

In this paper, the performance of DS-CDMA system with smart antenna is analyzed for different bandwidths (1.25MHz,5MHz) and different channel environments (rural, urban) in wideband multipath channel. For the analysis of smart antenna system, the vector channel having the spatio-temporal correlation is modeled as a time-variant linear filter in time, and each multipath is assumed as a reflective wave from only one direction (only one cluster) in space. Several multipath is within one chip are distingushed into each one and the strongest signal is selected, DS-CDMA system with smart antenna using wider bandwidth present better performance than that using narrow bandwidth. It is shown that the smart antenna is more effective in urban area when using 2D-RAKE receiver.

• 전자공학회논문지 IE
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• v.45 no.3
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• pp.13-19
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• 2008

In this paper, we propose a new IPC(Interlace to Progressive Conversion) method based on ELA(EDge Line based Average) interpolation using detecting the reliable edge direction. Existing ELA algorithms execute linear interpolation using edge direction without considering noises. In noisy images, these algorithms degrade quality because if interpolation based on the wrong edge direction. Out scheme is able to solve the problem of existing ELA algorithms in noisy images. First, filter a noisy pixel and estimate sizes of the noiseless orginal pixed and the noise, repectively. Then, considering the size of the noise, calculate weights of ELA and vertical interpolation. If noises exist after IPC, these could be eliminated by post filtering. The experimental results show that our proposed algorithm has about $1{\sim}2$ dB better performance than those of existing ELA algorithms.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.19 no.1
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• pp.61-70
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• 2008

This paper presents the flexible MEMS transmitter based on flexible printed circuit board or FPCB, which can be transformed to arbitrary shape. The FPCB is suitable to fabricate light weight and small size modules with the help of its thin thickness. Moreover a module based on FPCB can be attached on the arbitrary curved surface due to its flexible enough to be lolled up like paper. In this paper, the flexible MEMS transmitter integrated on FPCB for a short-distance sensor network which is based on orthogonal frequency division multiplexing(OFDM) communication system is proposed. The active device of the proposed flexible MEMS transmitter is fabricated on InGaP/GaAs HBT process which has been used for power amplifier design to take advantages of high linear and high efficient characteristics. Moreover, the passive devices such as the filter and signal lines are integrated and fabricated on the FPCB board. The performance of the fabricated flexible MEMS transmitter is analyzed with EVM characteristics of the output signal.

• KIPS Transactions on Software and Data Engineering
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• v.3 no.7
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• pp.277-284
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• 2014

The detection method of curves for the lanes which is powerful for the variation by utilizing the lane variation vector and cardinal spline on the inverse perspective transformation screen images which do not required the camera parameters are suggested in this paper. This method detects the lane area by setting the expected lane area in the s frame and next s+1 frame where the inverse perspective transformation and entire process of the lane filter are adapted, and expects the points of lane location in the next frames with the lane variation vector calculation from the detected lane areas. The scan area is set from the nextly expected lane position and new lane positions are detected within these areas, and the lane variation vectors are renewed with the detected lane position and the lanes are detected with application of cardinal spline for the control points inside the lane areas. The suggested method is a powerful method for curved lane detection, but it was adopted to the linear lanes too. It showed an excellent lane detection speed of about 20ms in processing a frame.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.34 no.4C
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• pp.363-370
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• 2009

Image interpolation addresses the problem of generating a high-resolution image from its low-resolution version. Classical linear interpolation algorithms are simple and popular, but they produce interpolated image with blurred edges and annoying artifacts, Thus, many edge-based interpolation algorithms have been proposed to improve the subjective quality of the interpolated image, especially around edges on the image. In this paper, we propose a new interpolation algorithm which uses edges extracted from binary image. The proposed algorithm is applied to the image after interpolating using 6-Tap FIR filter. The values of interpolation pixels on edges extracted from binary image are modified using neighborhood pixels on the same edge. Experimental results for various images show that the proposed method provides better performance than existing methods.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.48 no.2
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• pp.75-82
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• 1999

A compensation method of the motor parameters using zero sequence third harmonic voltage is presented for the speed sensorless vector control of the induction motor considering saturation of the flux. Generally, the air-gap flux of the saturated induction motor contains the space harmonic components rotating with the synchronous frequency of the motor. Because the EMF of the saturated induction motor contains the zero sequence harmonic voltages at the neutral point of the motor, those harmonic voltages can be used as a saturation index. In this work, the rotor flux observer is firstly designed for the speed sensorless vector control of induction motor. And a novel measurement method of the space harmonic voltage and a compensation method of th LPF(Low Pass Filter) are proposed. For compensating the non-linear variations of the magnetizing inductance depending on the saturation level of the motor, the dominant third harmonic voltage of the motor is used as a saturation function of the air-gap flux. And the variation of the stator resistance owing to the motor temperature can also be measured with the phase angle between the impressed voltage vector and the zero sequence voltage. The validity of the proposed parameter compensation scheme in the speed sensorless vector control using rotor flux observer is verified by the result of the simulations and the experiments.

• Journal of the Korean Institute of Intelligent Systems
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• v.21 no.4
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• pp.469-474
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• 2011

This paper presents the intelligent tracking method for maneuvering target using the positional error compensation of the maneuvering target. The difference between measured point and predict point is separated into acceleration and noise. K-means clustering and TS fuzzy system are used to get the optimal acceleration value. The membership function is determined for acceleration and noise which are divided by K-means clustering and the characteristics of the maneuvering target is figured out. Divided acceleration and noise are used in the tracking algorithm to compensate computational error. While calculating expected value, the non-linearity of the maneuvering target is recognized as linear one by dividing acceleration and the capability of Kalman filter is kept in the filtering process. The error for the non-linearity is compensated by approximated acceleration. The proposed system improves the adaptiveness and the robustness by adjusting the parameters in the membership function of fuzzy system. Procedures of the proposed algorithm can be implemented as an on-line system. Finally, some examples are provided to show the effectiveness of the proposed algorithm.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.28 no.2C
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• pp.181-192
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• 2003

Blind equalization of communication channel is important because it does not need training signal, nor does it require a priori channel information. So, we can increase the bandwidth efficiency. The linear prediction error method is perhaps the most attractive in practice due to the insensitive to blind channel equalizer length mismatch as well as for its simple adaptive implementation. Unfortunately, the previous one-step prediction error method is known to be limited in arbitrary decision delay. In this paper, we propose method for fractionally spaced blind equalizer with arbitrary decision delay using one-step forward prediction error filter from second-order statistics of the received signals for SIMO channel. Our algorithm utilizes the forward prediction error as training signal and computes the best decision delay from all possible decision delay. Simulation results are presented to demonstrate the performance of our proposed algorithm.

• Fire Science and Engineering
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• v.29 no.6
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• pp.91-97
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• 2015

Skyscrapers, large business buildings, and IT consumers use many appliances, and the electrical power stems can cause fires by overheating. This can result in damaged capacitors, lost data, rising ground potential, and communication obstacles from linear or nonlinear high frequency. To make sure of that we investigated 7 spots of a building, among which 6-spots were fair but the other one needed high frequency control. Spots 3, 6, and 7 needed diagnostic workup, and spots 2, 3, and 5 considered 5 high frequency currents. A phase is all of good but the high frequency current is greater than the standard level except for spot 1. As a result, a zigzag transformer or active filter needs to be installed, and the efficiency needs to be upgraded by investigating load unbalance factors and power factors.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.46 no.4
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• pp.296-302
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• 2001

Winter cereals are acclimated during wintering, and thereafter their freezing resistance is increased. In order to analyze inheritance and heritabilities for photoinhibition of photosynthesis by high light intensity under low temperature, and to evaluate the relationship between low temperature-induced photoinhibition and winter survival, 4 parental half diallel crosses were used. The detached leaves of 7-8cm long from plants grown for 35 and 55 days were placed on wet filter paper and placed in trays at 5$^{\circ}C$ cold room with 1,200 $\mu$mol $m^{-2}$ $s^{-1}$ PPFD. Chlorophyll fluorescence was measured with a chlorophyll fluorescence system after dark adaptation for 30 min. The Fv/Fm of 35day old plants was reduced from 0.714 in the control leaves to 0.409 and 0.368 following photoinhibitory treatment of 6h and 8h and the CVs were increased from 0.8% to 22.2-22.3%. The Fv/Fm of 55-day old plants was reduced from 0.775 in the control leaves to 0.485 and 0.439 following photoinhibitory treatment of 10h and 12h, respectively. According to half diallel cross analysis, Reno and Dongbori 1 (highly resistant to photoinhibition) was dominant, but Oweolbori (susceptible to photoinhibition) was recessive, and photoinhibition showed partial dominance with highly additive gene action. Dongbori 1 showed the greatest GCA effects for photoinhibition, and GCA/SCA ratios (8.7-22.3 times) indicated that the additive variance for the character was more important. Winter survival in barley crosses was positively correlated with resistance to photoinhibition and significantly fitted by linear regression ($R^2$=0.751$^{**}$-0.779$^{**}$). The chlorophyll fluorescence measured by Fv/Fm has been found to be highly inheritable and very useful in evaluating relative levels of freezing resistance in barley.ley.