• The Journal of the Korea Contents Association
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• v.13 no.5
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• pp.396-407
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• 2013

The role of influentials to maximize word-of-mouth effect can be seen to be very important. In this paper, we have the perspective of corporate marketing to understand Twitter influentials. We start from the point of view of who can induce eventually most exposure of tweets when he tweets the company's specific marketing messages. From this perspective, we observe both the follower influentials who have many followers and the retweet influentials who induce many retweets by visualizing graphs from network data collected via Twitter Search API. Although some users have small followers they may bring much more exposure than follower influentials if they can induce retweets by follower influentials. On the contrary, some retweet influentials who don't induce retweets by follower influentials may bring very little exposure. This suggests the fact that some small users who can induce retweets by influentials might have more important role than influentials themselves in order to increase the exposure of tweets. These users also are seen to have high centrality measures in the network structure.

• The Journal of the Korea Contents Association
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• v.3 no.3
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• pp.11-18
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• 2003

Error diffusion is a procedure for generating high quality bilevel images from continuous-tone images but blurs the edge information. To solve this problem, we propose the improved method appling edge enhanced weights based on local characteristic of the original images. We consider edge information as local characteristic. First, we produce edges by appling 3$\times$3 sobel operator to the original image. The edge is normalized from 0 to 1. Edge information weights are computed by using sinusoidal function and the normalized edge information. The edge enhanced weights are computed by using edge information weights multiplied input pixels. The proposed method is compared with conventional methods by measuring the edge correlation and quality of the recovered images from the halftoned images. The proposed method provides better quality than the conventional method due to the enhanced edge and represents efficiently the detail edge. Also, the proposed method is improved in edge representation than the conventional method.

• The Journal of the Korea Contents Association
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• v.15 no.9
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• pp.257-272
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• 2015

This study is to verify how the economic, social and moderating effect factors of baby boomer generation workers' affect the subjective health evaluation. The subjective of this study was 1,202 workers of baby boomer generation by using the 4th data of Korea longitudinal study of aging(KLoSA) from Korea Labor Institute in 2012. Economic and social factors were selected as scales to analyze if there is meaningful difference in subjective health evaluation. Method of frequency analysis, t-test, ANOVA and correlation analysis was used, and multi regression analysis was also conducted to verify whether the private health insurance has control effect over the relation between the subjective health evaluation and the economic & social factor. As a result of the study, age, education, home ownership, peer group meeting, overall satisfaction, private health insurance were major factors affecting the subjective health evaluation of baby boomer generation. Moreover private health care were turned out to have a moderation effect in relation between economic, social factor and subjective health evaluation.

• Journal of Periodontal and Implant Science
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• v.25 no.2
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• pp.372-385
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• 1995

본 연구의 목적은 비외과적 치주치료시 부가적으로 사용하기 위해 실험적으로 개발한 젤 형태의 테트라사이클린 및 테트라사이클린-구연산 혼합젤의 치근면에 대한 시간에 따른 활성도를 측정하고, 이를 용액 형태의 테트라사이클린 제제 또는 클로르헥시딘 들과 비교하는 것이다. 6명의 환자로 부터 18개의 발치된 치아를 실험대상으로 하였으며, 치아는 발치한 즉시 치석제거술과 치근활택술을 시행한 후 각 각 4개씩 4군으로 나누어 다옴과 같은 처치롤 하였다 ; 1) O.1% 클로르핵시딘 용액에 5분간 침전; 2) 50mg/ml의 테트라사이클린 용액에 5분간 침전; 3) 5% 테트라사이클린 젤에 5 분간 처리 ; 4) 테트라사이클린-구연산 혼합첼로 5 분간 처치; 5) 그리고 2개의 치아는 대조군으로서 멸균된 생리식염수에 5분간 처리하였다. 침전후 치아는 1ml의 tris-buffered saline이 담긴 용기에 옮겨 24시간 간격으로 탈착된 TBS용액올 교체하면서 실온에서 22일간 보관하였다. Porphyromonas gingivalis를 indicator organism으로 하여 microtiter assay를 이용하여 홉광도를 측정 함으로써 제거 된 용액 의 항 미생물 활성올 측정하였다. 1. 50mg/ml 의 테트라사이클린 수용액에 침전되었던 군은 생리식염수로 처리한 군에 비하여 17 일간 클로르헥시딘으로 처리한 군에 비하여는 16일간 항미생물 활성에 있어서 유의성 있는 차이를 보였다. 2. 테트라사이클린 젤과 테트라사이클린-구연산 혼합첼로 처리한 군은 대조군에 비하여 각 각 4일과 3일 까지 활성올 보였다. 3. 0.1% 클로르핵시딘 용액으로 처리한 군은 생리식염수로 처치한 군에 비하여 24시간 밖에 활성을 나타내지 못했다. 4. 전반척으로 테트라사이클린-구연산 혼합첼로 처리한 군에 비하여 테트라사이클린 첼로 처리한 군의 활성이 높았으나 유의성 있는 차이롤 보이지는 않았다.

• The Journal of the Acoustical Society of Korea
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• v.20 no.3
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• pp.48-55
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• 2001

A novel method to reduce additive non-stationary noise is proposed. The method requires neither the information about noise nor the estimate of the noise statistics from any pause regions. The enhancement is performed on a band-by-band basis for each time frame. Based on both the decision on whether a particular band in a frame is speech or noise dominant and the masking property of the human auditory system, an appropriate amount of noise is reduced using spectral subtraction. The proposed method was tested on various noisy conditions (car noise, Fl6 noise, white Gaussian noise, pink noise, tank noise and babble noise) and on the basis of comparing segmental SNR with spectral subtraction method and visually inspecting the enhanced spectrograms and listening to the enhanced speech, the method was able to effectively reduce various noise while minimizing distortion to speech.

• Journal of Digital Convergence
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• v.18 no.5
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• pp.505-512
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• 2020

This study is done to provide basic data on the effective operation of the new policies by examining the satisfaction level of the elderly with dementia visiting dementia care centers located in 25 autonomous districts of S city. Self-administered questionnaires were distributed to 217 elderly with dementia who visited the above dementia care center from July 1 to September 30, 2019. The satisfaction tool is a chart score scale that displays negative-positive expressions at both ends of a straight line. The result shows that satisfaction level is significantly higher in the group with trust in the visiting institutions than in the group with distrust (t=9.74, p<.001), higher in cognitive impairment group than in dementia group (t=0.13, p=.034), and higher in mild depression group than in more severe depression group (t=2.31, p=.022). Satisfaction ratios analyzed by logistic regression shows significant differences in factors like gender, age, education, and walking pattern. In conclusion, it is important to run health support programs that consider user characteristics to improve the satisfaction of newly introduced dementia care centers.

• Journal of KIISE:Computer Systems and Theory
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• v.33 no.12
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• pp.885-893
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• 2006

The Bayesian network(BN) has emerged in recent years as a powerful technique for handling uncertainty iii complex domains. Parameter learning of BN to find the most proper network from given data set has been investigated to decrease the time and effort for designing BN. Off-line learning needs much time and effort to gather the enough data and since there are uncertainties in real world, it is hard to get the complete data. In this paper, we propose an online learning method of Bayesian network parameters from incomplete data. It provides higher flexibility through learning from incomplete data and higher adaptability on environments through online learning. The results of comparison with Voting EM algorithm proposed by Cohen at el. confirm that the proposed method has the same performance in complete data set and higher performance in incomplete data set, comparing with Voting EM algorithm.

• Journal of the Korean Chemical Society
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• v.52 no.1
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• pp.7-15
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• 2008

Molecular motion influencing the absorption spectrum of a chromophore in liquid is theoretically described by a quantum mechanical time correlation function. In the present paper, we developed a theoretical method to calculate such a quantum mechanical time-correlation function from a classical time-correlation function using semi-classical approximations. The calculated time-correlation function was combined with the second order cumulant expansion method to calculate the absorption spectrum of nile blue in acetonitrile. Reasonably good agreement with experimental spectrum was obtained. From the comparison with experimental spectrum, we concluded that the time scale of solvation dynamics of the system should be longer then 1ps and the first shell of solvent is the major contribution to the solvation dynamics.

• Journal of the Korean Institute of Intelligent Systems
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• v.12 no.5
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• pp.467-472
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• 2002

In this paper, we propose a Fuzzy Cellular Neural Network(FCNN) that is based on a-Least Trimmed Square Hausdorff distance(a-LTSHD) which applies Hausdorff distance(HD) to the FCNN structure in order to remove the impulse noise of images effectively and also improve the speed of operation. FCNN incorporates Fuzzy set theory to Cellular Neural Network(CNN) structure and HD is used as a scale which computes the distance between set or two pixels in binary images without confrontation of the feature object. This method has been widely used with the adjustment of the object. For performance evaluation, our proposed method is analyzed in comparison with the conventional FCNN, with the Opening-Closing(OC) method, and the LTSHD based FCNN by using Mean Square Error(MSE) and Signal to Noise Ratio(SNR). As a result, the performance of our proposed network structure is found to be superior to the other algorithms in the removal of impulse noise.

• Journal of the Korean Data and Information Science Society
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• v.27 no.4
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• pp.899-910
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• 2016

Asymptotic tests are often not suitable for the analysis of sparse ordered contingency tables as asymptotic p-values may either overestimate or underestimate the true pvalues. In this pater, we describe permutation procedures in which we compute exact or resampling p-values for a weighted specific-category agreement in ordered $k{\times}k$ contingency tables. We use the weighted specific-category kappa proposed by $Kv{\dot{a}}lseth$ to measure the extent to which two independent raters agree on the specific categories. We carried out comparison studies between exact p-values, resampling p-values and asymptotic p-values using $3{\times}3$ contingency data (real and artificial data sets) and $4{\times}4$ artificial contingency data.