• The Journal of the Korea institute of electronic communication sciences
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• v.17 no.4
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• pp.695-702
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• 2022

Smart railway system, which has been actively studied in recent years, is entering the intelligent stage beyond the automation stage based on ICT (Information & Communication Technology) such as communication technology and information technology. ICT technology used in smart railways is generally supported by various information protection technologies as it is vulnerable to information infringement. As a means of high-speed/mass transportation, it is essential to devise an information protection plan for ICT technology that forms the basis for smartening the railway system. Therefore, this paper presents the necessity of step-by-step information protection that measures for smart railway communication by examining potential risk factors of smart railway communication base and considering information protection factors that can respond to them.

• The Journal of the Korea institute of electronic communication sciences
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• v.16 no.2
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• pp.371-378
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• 2021

In this study, in order to analyze the spatial distribution of cold water occurred in the Southeast Sea of Korea, the K-means clustering method was used to analyze the ocean observatory buoy of Gori and Yangpo and GHTSST Level 4 from 2016 to 2018. The buoy data was used to identify the change in sea water temperature and the cold water occurrence at Gori and Yangpo in the Southeast Sea. As a result, the sea water temperature of Gori and Yangpo decreased equally at the cold water occurrence. Therefore, the reciprocal of the sea water temperature and the variance of SST were compared to see the changes of SST when the cold water occurs. When the reciprocal of the sea water temperature increases, the dispersion of SST also increases. Through this, it can be seen that there is a change in the water temperature distribution of SST in the sea when the cold water occurs. After that, K-means clustering was used to classify the cold water. After analyzing the optimal K value for clustering by using the Elbow method, it was possible to classify a region with cold water. Through this, it is estimated that the spatial distribution and diffusion range of the cold water, and it can be estimated and used in future studies to identify damage caused by the cold water and predict spatial spread.

• International Journal of Contents
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• v.10 no.4
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• pp.18-22
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• 2014

Social network games (SNGs), a rapidly growing online game genre, are built and played on social network sites. SNGs provide an online world for enjoying leisure time and interpersonal communication, and an increasing numbers of college students are involved in such game-playing as a leisure time activity. Despite the popularity, relatively few studies have been conducted to investigate the nature of game players, especially the meaning of such leisure time behavior by college students. This paper's aim was to explore a subjective meaning structure of online social network game play. The means-end chain model was used to link attributes of SNGs to the underlying values of game playing as a leisure activity. The results revealed two emerging end-values: the need for bridging and a sense of belonging. This study sheds light on the meaning of college students' leisure activities when playing social network games.

• International journal of advanced smart convergence
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• v.8 no.2
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• pp.30-38
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• 2019

Recently, the spread of personal mobility has been rapidly increasing due to the development of environmentally friendly alternative transportation means. In addition, the level of battery technology is also rapidly developing, accelerating the popularization of personal mobility. Such personal mobility has convenience of location transfer, amusement, and high portability compared to other transportation devices. Most personal mobility, however, is made up of small wheels, which cannot overcome obstacles such as rugged roads or obstacles on the road. In this paper, to solve these problems, we tried to devise a device that can easily overcome obstacles by combining wheels with small moving means. The wheel size can be mounted on the front wheel of the small moving means in a protruding manner so that obstacles can be encountered before the front wheels and the safety and ride comfort of the running can be improved.

• Journal of information and communication convergence engineering
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• v.7 no.3
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• pp.383-391
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• 2009

In this paper, blind equalization using a modified Fuzzy C-Means algorithm with Gaussian Weights (MFCM_GW) is attempted to the heavy noise-corrupted channels. The proposed algorithm can deal with both of linear and nonlinear channels, because it searches for the optimal channel output states of a channel instead of estimating the channel parameters in a direct manner. In contrast to the common Euclidean distance in Fuzzy C-Means (FCM), the use of the Bayesian likelihood fitness function and the Gaussian weighted partition matrix is exploited in its search procedure. The selected channel states by MFCM_GW are always close to the optimal set of a channel even the additive white Gaussian noise (AWGN) is heavily corrupted in it. Simulation studies demonstrate that the performance of the proposed method is relatively superior to existing genetic algorithm (GA) and conventional FCM based methods in terms of accuracy and speed.

• Journal of Korean Academy of Nursing
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• v.33 no.1
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• pp.104-112
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• 2003

Purpose: While most psychiatrists diagnose Hwa-Byung as a chronic psychogenic disorder associated with familial, financial and personality, the purpose of study was to shed light on the nature of Hwa-Byung through pragmatics. Hwa-Byung is characterized as ‘Hwa’ which means fire ‘Byung’ which means disease. This condition cannot be empirically experienced, rather it is represented by suffering internally (in the mind). It also could find an aspect of somatization, and self-diagnosing. Method: As patients themselves diagnose Hwa-Byung, pragmatical approach was taken to analyze the context of the learning through their communication with others. The case examples resulted from in-depth telephone counseling with a client who is housewife with Hwa-Byung over a period of time at the Women's Hot Line. Result: The study showed that the client experienced continuous improper attacks by her husband. She expressed improperness by applying her personal emotions to social-justice reasoning. Conclusion: ‘Hwa’ means lack of mutual intimacy in this research. By expressing this ‘Hwa’, the client would like to recover mutual intimacy with her husband.

• Journal of information and communication convergence engineering
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• v.15 no.1
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• pp.49-52
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• 2017

Ganglion cysts are benign soft tissues usually encountered in the wrist. In this paper, we propose a method to extract a ganglion cyst region from ultrasonography images by using image segmentation. The proposed method using the possibilistic c-means (PCM) clustering method is applicable to ganglion cyst extraction. The methods considered in this thesis are fuzzy stretching, median filter, PCM clustering, and connected component labeling. Fuzzy stretching performs well on ultrasonography images and improves the original image. Median filter reduces the speckle noise without decreasing the image sharpness. PCM clustering is used for categorizing pixels into the given cluster centers. Connected component labeling is used for labeling the objects in an image and extracting the cyst region. Further, PCM clustering is more robust in the case of noisy data, and the proposed method can extract a ganglion cyst area with an accuracy of 80% (16 out of 20 images).

• International journal of advanced smart convergence
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• v.1 no.2
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• pp.30-33
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• 2012

This paper propose a new design of fuzzy neural networks based on hard partition to generate the rules of the networks. For this we use hard c-means (HCM) clustering algorithm. The premise part of the rules of the proposed networks is realized with the aid of the hard partition of input space generated by HCM clustering algorithm. The consequence part of the rule is represented by polynomial functions. And the coefficients of the polynomial functions are learned by BP algorithm. The number of the hard partition of input space equals the number of clusters and the individual partitioned spaces indicate the rules of the networks. Due to these characteristics, we may alleviate the problem of the curse of dimensionality. The proposed networks are evaluated with the use of numerical experimentation.

• Journal of Communications and Networks
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• v.11 no.4
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• pp.384-389
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• 2009

Optical wireless communication (OWC) systems are rapidly gaining popularity as effective means of transferring data at high rates over short distances. OWC facilitates rapidly deployable, lightweight, high-capacity communication without licensing fees and tariffs. Nevertheless, the performance of this new technology depends strongly on the atmospheric conditions and the characteristics of the link. In this work, we study the influence of these parameters on both the average (ergodic) capacity and the outage capacity of an OWC system over moderate to strong turbulence channels modeled by gamma-gamma distribution. Moreover, we compare the results that we obtain estimating the average and outage capacities.

• International Journal of Computer Science & Network Security
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• v.21 no.11
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• pp.287-293
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• 2021

The purpose of this article is to consider the distance education system, its principles, features and means. One of its existing and promising tools is video conferencing. The article discusses the types of video conferencing, hardware and software, features and requirements for communication channels, types of information transmitted through these channels.