• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.12B
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• pp.1076-1086
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• 2006

In providing video-on-demand (VoD) services to a number of clients through networks, the bandwidth requirements of video transmission restrict VoD services. For this reason, many significant broadcasting-based VoD schemes have been proposed to efficiently support services. However, the broadcasting-based VoD schemes approach needs frequency channel hopping, using many channels at the same time and managing many segments of a video. These make it difficult to implement. In this paper, we propose a Harmonic Staggered broadcasting scheme which has a simple structure and substantially improved VoD efficiency. The numerical results demonstrate that the viewer's waiting time of the Harmonic Staggered broadcasting scheme is close to the harmonic broadcasting scheme and the maximum buffer requirements of this can be adapted for demanding rate by adjusting the short front part of a video sizes.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.46 no.1
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• pp.55-62
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• 2009

In this paper, we propose a method on the training sequence based on channel estimation issues for relay networks that employ amplify-and-forward(AF) transmission scheme. In $^{[1]}$ and $^{[2]}$, we have to point out that jointly estimating the channel from source to relay and from relay to destination suffers from many drawbacks in fast fading case because the estimation of previous pilots is not suitable for current channel. In this paper, we consider a new joint estimation of overall channel impulse response(CIR) using one OFDM signal without pilots. Using the maximum likelihood(ML) function, we derive a channel estimator by taking the frequency domain of transmitted signal as Gaussian and averaging the ML function over the resulting Gaussian distribution. Simulation results show that our proposed channel estimator performs a fraction of 1dB compared with $^{[1]}$ in high SNR region.

• Proceedings of the Korean Geotechical Society Conference
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• 2007.09a
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• pp.266-292
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• 2007

Round Robin Test (RRT) on ground response analyses was conducted for three sites in Korea based on several site investigation data, which include borehole logs with the N values from standard penetration test (SPT) for all three sites and additionally cone tip resistance profiles for two sites. Three input earthquake motions together with the site investigation data were provided for the RRT. A total of 12 teams participating in this RRT presented the results of ground response analyses using equivalent-linear and/or nonlinear method. Each team determined input geotechnical properties by using empirical relationships and literatures based on own judgment, with the exception of the input motions. Herein, the characteristics of input motions were compared in terms of the frequency and period, and the selection of the depth to bedrock, on which the motions is impinged, was discussed considering geologic conditions in Korea. Furthermore, a variety of geotechnical properties such as shear wave velocity profiles and soil nonlinear curves were investigated with the input properties used in this RRT.

• Child Health Nursing Research
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• v.10 no.1
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• pp.37-47
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• 2004

Purpose: This study aimed to identify the alcohol drinking pattern of parents and to analyze drinking related factors in problem drinking among adolescent's parents. Method: This study was conducted through a structured questioning from November 5th to 22th in 2002. Those are 2,522 parents of the students of the 1st and 2nd grade who were selected randomly among 26 middle and high schools located in Socho-gu, Seoul. Data was analyzed using SAS program that included descriptive statistics, Chi-square test, and multiple logistic regression analysis. Result: 1. For frequency of drinking, 33.1％ of the subjects responded to drink two-four times a month, 26.0％ drink more than two times a week. 2. For the amount of drinking, 29.6％ drink one or two glasses while 9.4％ drink over ten glasses at a time. 3. The mean AUDIT score was 8.27 7.02(score of range: 0- 40). 4. Based on AUDIT score, drinkers with less than eight point from AUDIT(normal group) were 55.1％, from more than eight point to less than twelve point from AUDIT(problematic drinker) were 16.3％, and more than twelve point from AUDIT(alcohol abuse and dependency) were 28.6％. 5. Based on more than twelve point from AUDIT, female(mother), high school and, have religion, housekeeper were the significantly higher score than counter parts. Conclusion: Alcohol drinking pattern and level of drinking of their parents links to their children's drinking and results in family, social, and national loss. Active prevention is needed. Specially, pertinent education about drinking and public education for mothers who are housekeepers should be carried out with concentrated intervention programs for the problematic drinker so alcohol abuse and dependency can be reduced.

• Journal of Korean Public Health Nursing
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• v.21 no.1
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• pp.5-14
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• 2007

Purpose: The purpose of this study was to examine the effects of a group walking exercise on body composition, blood lipid profiles and psychological factors. Also this study was to examine the satisfaction of walking exercise and characteristics of the exercise behavior among participants. Method: The subjects, aged 30 to 77 years, were 138 participants in a 24-week, group walking exercise. A walking exercise protocol and education was given to the participants, which was to do walking over three times a week and over thirty minutes each time. We compared the participants' body composition (BMI, PBF, BFM, FFM, WHR and VFA), blood lipid profiles (HDL-C, LDL-C, total cholesterol, triglyceride), exercise self-efficacy and quality of life before and after group walking excercise. Collected data were analyzed through paired t-test using the SAS program. Results: Mean walking frequency was 11.4 times per month and mean walking time was 71.5 min. BMI, PBF, BFM, WHR, and VFA were significantly decreased. FFM increased significantly (p=.0002). There were significant decreased in TC, LDL-C and TG.. Exercise self-efficacy did not increase significantly, but quality of life increased significantly(p=.0088). Conclusion: Community-Based 24 weeks group walking exercise program had positive effects on body composition, blood lipids and quality of life.

• Journal of Korean Academy of Nursing
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• v.37 no.1
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• pp.72-80
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• 2007

Purpose: This study was to analyze the trend of research on intervention for patients with metabolic syndrome. Method: Using Pubmed, Medline, and CINAHL search engines, a randomized controlled trial(RCT) researching titles such as 'metabolic syndrome', 'intervention', 'lifestyle modification', or 'community-based' were collected. A total of 16 researches were analyzed based on the guidelines of the National Cholesterol Education Program - Adult Treatment Panel(NCEP-ATP III). Results: 1) The total period of the intervention was from 12 to 24 weeks, the frequency was 3 to 5 times per week, and the duration of each session was from 45 to 60 minutes. The types of intervention included exercise, diet, and medication. Among these types, diet was performed most frequently. 2) The outcomes of the intervention was measured with physical aspects such as anthropometric measures, body composition, or biological markers. No studies have evaluated psychosocial outcomes such as quality of life. 3) In terms of effectiveness of the intervention, anthropometric indicators, body composition, or serological markers showed positive effects, whereas results on endothelial or urine indicators were inconsistent. Conclusion: Methodological research developing comprehensive therapeutic lifestyle modification programs and intervention studies are needed for patients with metabolic syndrome. In addition, effects should be evaluated with multidimensional perspectives.

• Journal of IKEEE
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• v.23 no.4
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• pp.1302-1308
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• 2019

This paper presents an approach for classifying image made by acquired position data from a 2D Lidar sensor with a convolutional neural network (CNN). Lidar sensor has been widely used for unmanned devices owing to advantages in term of data accuracy, robustness against geometry distortion and light variations. A CNN algorithm consists of one or more convolutional and pooling layers and has shown a satisfactory performance for image classification. In this paper, different types of CNN architectures based on training methods, Gradient Descent(GD) and Levenberg-arquardt(LM), are implemented. The LM method has two types based on the frequency of approximating Hessian matrix, one of the factors to update training parameters. Simulation results of the LM algorithms show better classification performance of the image data than that of the GD algorithm. In addition, the LM algorithm with more frequent Hessian matrix approximation shows a smaller error than the other type of LM algorithm.

• Journal of the Korean Institute of Intelligent Systems
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• v.8 no.2
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• pp.9-20
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• 1998

In this paper, a new distance relaying scheme is proposed. Artificial neural networks are applied to the distance relaying system composed of pattern recognition based. The proposed distance relaying scheme has two blocks of pattern recognition stages to estimate the fundamental frequency and to classify the fault types. In the first block, a filtering method using neural networks called a neural networks mapping filter(NMF) is presented to efficiently extract the features. And in the sec'ond block, the estimator called neural networks fault pattern estimator(NFPE) is also presented to classify the fault types by the extracted effective features obtained from NMF. Each block of these applied schemes is trained by back-propagation algorithm of multilayer perceptron and show the fast and accurate pattern recognition by ability of multilayer neural networks. The test result of this approach are obtained the good performance from the fault transient wave signals of EMTP(e1ectromagnetic transients program) in the various fault conditions of power systems.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.39 no.3
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• pp.32-43
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• 2002

In this paper, we propose a pattern classification system for digital signal which is based on neural networks. The proposed system consists of two models of neural network. The first part is a wavelet neural network whose role is a feature extraction. For this part, we compare existing models of wavelet networks and propose a new model for feature extraction. The other part is a wavelet network for pattern classification. We modify the structure of previous wavelet network for pattern classification and propose a learning method. The inputs of the pattern classification wavelet network is connection weights, dilation and translation parameters in hidden nodes of feature extraction network. And the output is a class of the signal which is input of feature extraction network. The proposed system is, applied to classification of EEG signal based on frequency.

• Journal of the Korean Society of Costume
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• v.24
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• pp.217-233
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• 1995

The ultimate purpose of this study is to suggest the most effective marketing strategy for the clothing consumer market based on the new generation consumer's clothing selection behavior analysis. In this thesis, it is appempted to make a progress in the new gen-eration consumer's clothing life style types, in clothing purchase behavior analysis among the clothing life style, and also in the marketing strategy for marketers. The subjects selected for the final analysis are 412 the new gerneration women of age 20 thru 34 in seoul and satellite town area. Data were processed the spss package program. As for the analytic method, factor analysis, clustering analysis, XCross-tubulation, F-test with ANOVA, frequency and percentage were applied in the survey. The major findings are as following : life style is classified into four types : The characteristic fashion-directory type(25.7%) ; The reason traditional type(9.0%) ; The sen-sitivity fashion-following type(11.0%) ; The community brand-conscious type(54.3%). 2 Clothing life style types characteristic of the new generation consumer proved that clothing life style types are a significant difference according to the life style, the fashion consciousness and the average monthly spend-ing on clothing. 3. There is an important discrimination according to the clothing life style types in their clothing purchase behavior such as infor-mation usage, clothing choice criterion and brand loyalty. 4. Based on the result of our analysis and the review of literature, the marketing strategy is suggested that characteristic and new design development is efficient way to consumer's purchase need. Therefore apparel industary which pursue an added value must frame marketing strategy on the basis of the target consumer's sensitivity characteristic according to the life style and fashion consciousness.