• Journal of the Institute of Electronics Engineers of Korea TC
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• v.47 no.2
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• pp.47-55
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• 2010

The power line communication channel has characteristic variation problems which are caused by load. The spread spectrum technique has been used to overcome these problems. One of that is the direct sequence spread spectrum(DS/SS) system which is not necessary to additional hardwares. The BER of DS/SS system is decreased by longer length of PN code, but data transfer rate is decreases, so data transfer rate is hard to satisfies their own specifications especially in narrowband PLC systems. Spread Spectrum system with Dual-processing Gain tries to reflect cyclic characteristics of power line noise. But that system assumes that shapes of power line channel are symmetrical with respect to the 1/4 point of main frequency(60Hz in Korea), therefore cannot achieves various shapes of real power line noise. Thus in this paper, noise adaptive DS/SS system which PN code is changed by noise levels for various channel noises is proposed and simulated. The different kinds of noises are modeled and measured for simulation, the proposed system is verified that has lower data transfer rate and lower error rate than conventional system by simulation results.

• Journal of the Institute of Electronics and Information Engineers
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• v.53 no.4
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• pp.142-148
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• 2016

Recently, human identification using various biological signals has been studied and human identification based on the gait has been actively studied. In this paper, we propose a human identification based on the EMG(Electromyography) signal of the thigh muscles that are used when walking. Various features such as RMS, MAV, VAR, WAMP, ZC, SSC, IEMG, MMAV1, MMAV2, MAVSLP, SSI, WL are extracted from EMG signal data and ANN(Artificial Neural Network) classifier is used for human identification. When we evaluated the recognition ratio per channel and features to select approptiate channels and features for human identification. The experimental results show that the rectus femoris, semitendinous, vastus lateralis are appropriate muscles for human identification and MAV, ZC, IEMG, MMAV1, MAVSLP are adaptable features for human identification. Experimental results also show that the average recognition ratio of method of using all channels and features is 99.7% and that of using selected 3 channels and 5 features is 96%. Therefore, we confirm that the EMG signal can be applied to gait based human identification and EMG signal based human identification using small number of adaptive muscles and features shows good performance.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.48 no.4
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• pp.98-106
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• 2011

Since prediction processes such as motion estimation motion compensation are not at the WZ video encoder but at its decoder, WZ video compression cannot have better performance than that of conventional video encoder. In order to implement the prediction process with low complexity at the encoder, WZ residual coding was proposed. Instead of original WZ frames, WZ residual coding encodes the residual signal between key frames and WZ frames. Although the proposed WZ residual coding has good performance in pixel domain, it does not have any improvements in transform domain compared to transform domain WZ coding. The WZ residual coding in transform domain is difficult to have better performance, because pre-defined quantization matrices in WZ coding are not compatible with WZ residual coding. In this paper, we propose a new quantization method modifying quantization matrix and quantization step size adaptively for transform domain WZ residual coding. Experimental result shows 22% gain in BDBR and 1.2dB gain in BDPSNR.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.44 no.1
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• pp.26-39
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• 2007

In recent years, rate control is an important technique in real time video communication applications using H.264/AVC. Many existing rate control algorithms employ the quadratic rate-distortion model, which is determine the target bits for each P frame. In this paper, a new rate control algorithm for transmission of H.264/AVC video bit stream through CBR(Constant Bit Rate) channel is proposed. The proposed algorithm predicts an adaptive QP(Quantization Parameter) for improving video distortion, due to high motion and abruptly scene change, which target bit rate and MAD(Mean of Absolute Difference) for current frame considering image complexity variance between previous and current frames. Additionally, it uses frame skip technique to maintain bit stream within a manageable range and protect buffer from overflow or underflow. Experimental results show that the proposed method gives a quality improvement of about 0.5dB when compared to previous rate control algorithm. Also our proposed algorithm encodes the video sequences with less frame skipping compared to the existing rate control for H.264/AVC.

• Journal of the Institute of Electronics and Information Engineers
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• v.50 no.9
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• pp.136-143
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• 2013

In this paper, a algorithm to find joints of a small animal like a lizard from the multiple-view silhouette images is presented. The proposed algorithm is able to calculate the 3D coordinates so that the locomotion of the lizard is markerlessly reconstructed. The silhouette images of the lizard was obtained by a adaptive threshold algorithm. The skeleton image of the silhouette image was obtained by Zhang-Suen method. The back-bone line, head and tail point were detected with the A* search algorithm and the elimination of the ortho-diagonal connection algorithm. Shoulder joints and hip joints of a lizard were found by $3{\times}3$ masking of the thicked back-bone line. Foot points were obtained by morphology calculation. Finally elbow and knee joint were calculated by the ortho distance from the lines of foot points and shoulder/hip joint. The performance of the suggested algorithm was evaluated through the experiment of detecting joints of a small lizard.

• The Journal of the Acoustical Society of Korea
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• v.19 no.1
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• pp.16-24
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• 2000

In this paper the performance of a closed-loop power control scheme using variable step size decision method for DS/CDMA based-low earth orbit(LEO) mobile satellite systems in which the long round trip delay is a dominant performance degradation factor is evaluated. Because there are fundamental differences in the characteristics between the LEO mobile satellite channel and terrestrial mobile channel, such as long round trip delay and different elevation angle, these factors are considered in channel modeling based on the European Space Agency(ESA) measurement data. Since the round trip delay (from the mobile terminal to the gateway station via satellite) is typically 10∼20ms in low altitude satellite channels, closed-loop power control is much less effective than it is on a terrestrial channel. Thus, the adaptive power control scheme using a variable step size control is essential for overcoming the long round trip delay and fading due to the elevation angle. It is shown that the standard deviation of signal to interference ratio(SIR) adopting a variable step size closed-loop power control scheme is much less than that of a fixed step size closed-loop power control. Furthermore, we have driven the conclusion that the measurement interval of power control commands is optimal choice when it is twice the round trip delay.

• Journal of KIISE:Software and Applications
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• v.32 no.3
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• pp.192-201
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• 2005

For the past ten years, the goal of ubiquitous computing research has been the establishment of a new technology system with the aim 'Anytime, Anywhere, and Any form'. The needs for agent technology innovations such as ontology-based structure, ontology-based agent communication language, and multi-agents frameworks have been identified. This paper proposes a noble multi-agents architecture for ubiquitous systems. We suggest four major steps in the interaction between human and agents which enable ubiquitous agents to process by themselves to provide adaptive service to meet human's needs. First, we propose a semantic web technology to represent the association between information resources more explicitly Second, we construct a semantic ontology so that agents can recognize web contents.'Third, we propose a method to communicate between agents using OWL ontologies. Finally, we suggest a multi-agents structure based on the JADE of FIPA to analyze messages and get information. The semantic multi-agents framework proposed in this paper infers semantic situations using semantic web technology based on ontologies. A service provided is inferred differently according to user state because the multi-agents communicate by using OWL ontology language. Therefore, our system better infers context information than other without ontologies.

• The Korean Journal of Rehabilitation Nursing
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• v.2 no.1
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• pp.95-108
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• 1999

The purpose of this study was to identify the effect of the humor intervention program, administred to the hemodialysis patient as an adaptive coping mechanism. The research design was non-equivalent control group non-synchronized design. The study method had been done by investigating the experimental group and control group through the questionnaire on 36 patients who had been out patient hemodialysis room at B hospital in Pusan from August 18 to September 15, 1998. The humor intervention program consisted of 1 TV comedy, 1 home video and 1 comedy film. The humor intervention program was provided to the experimental group for 20-30 minute 3 times every other day at hemodialysis room. Dependent variables were measured by Spielberger's State Anxiety Inventory, Zung's Self Rating Depression Scale, Lefcourt & s Humor Coping Scale. The analysis of the collected data had been done for the hemogeneity test in which general characteristics of the experimental group and the control group had been tested by $X^2$-test and the hemogeneity test had been tested by t-test before using the humor intervention program which is for anxiety, depression and coping of humor. To test the hypothesis the t-test had been given for the difference of anxiety, depression and coping of humor between the two groups. The result were summarized as follows : 1. Anxiety score in the experimental group and control group was not significant difference. 2. Depression score in the experimental group and control group was not significant difference. 3. Coping of humor score in the experimental group and control group was not significant difference. In conclusion, even though humor intervention program did not have any efficient effect on hemodialysis patients in reacting to anxiety, depression and coping humor, it caused very positive reactions from patients, and it also reducted anxiety of patients among the experimental group a little bit. If this program could be sufficiently applied ac cording to the character of every patients with a little bit different appliences such as selection of humor intervention program, frequency and period, it will be used as an efficient the humor intervention program.

• Journal of Korea Water Resources Association
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• v.49 no.8
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• pp.685-692
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• 2016

This study aimed to develop the indicator-based approach to assess water use vulnerability in watersheds and applied to the unit watershed within the Han River watershed. Vulnerability indices were comprised of three sub-components (exposure, sensitivity, adaptive capacity) with respect to water use. The indicators were made up of 16 water use indicators. Then we estimated vulnerability indices using the Technique for Order of Preference by Similarity to Ideal Solution approach (TOPSIS). We collected environmental and socio-economic data from national statistics database, and used them for simulated results by the Soil and Water Assessment Tool (SWAT) model. For estimating the weighted values for each indicator, expert surveys for subjective weight and data-based Shannon's entropy method for objective weight were utilized. With comparing the vulnerability ranks and analyzing rank correlation between two methods, we evaluated the vulnerabilities for the Han River watershed. For water use, vulnerable watersheds showed high water use and the water leakage ratio. The indices from both weighting methods showed similar spatial distribution in general. Such results suggests that the approach to consider different weighting methods would be important for reliably assessing the water use vulnerability in watersheds.

• Journal of Internet Computing and Services
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• v.16 no.1
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• pp.29-37
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• 2015

In this paper, we propose a robust pre-processing module for camera-based Optical Music Score Recognition (OMR) on mobile device. The captured images likely suffer for recognition from many distortions such as illumination, blur, low resolution, etc. Especially, the complex background music sheets recognition are difficult. Through any symbol recognition system, the staff line height and staff line space are used many times and have a big impact on recognition module. A robust and accurate staff line height and staff line space are essential. Some staff line height and staff line space are proposed for binary image. But in case of complex background music sheet image, the binarization results from common binarization algorithm are not satisfactory. It can cause incorrect staff line height and staff line space estimation. We propose a robust staff line height and staff line space estimation by using run-length encoding technique on edge image. Proposed method is composed of two steps, first step, we conducted the staff line height and staff line space estimation based on edge image using by Sobel operator on image blocks. Each column of edge image is encoded by run-length encoding algorithm Second step, we detect the staff line using by Stable Path algorithm and removal the staff line using by adaptive Line Track Height algorithm which is to track the staff lines positions. The result has shown that robust and accurate estimation is possible even in complex background cases.