• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.7 no.5
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• pp.122-130
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• 2008

Improving the transmission rates of multi-media delivery, such as moving pictures and internet services, has become increasingly important in modern society. To satisfy such high data rate requirements, the MIMO technique, which has the capacity to transmit large amounts of data using limited frequency resources, was developed. The Space Division Multiplexing (SDM) system is one of the MIMO techniques to be able to improve the transmission capacity. However, it is unable to achieve diversity gain because of interference due to the use of multiple antennas. In this paper, an SDM system that utilizes a Multi-Block method as an advanced transmission technique in a wireless communication system to obtain diversity gain is proposed and discussed fur the performance of the proposed system.

• The Journal of Korean Academic Society of Nursing Education
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• v.6 no.1
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• pp.7-22
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• 2000

The purpose of this study was to identified the level of the exposure to the PC Pornography and what's their post-exposure reactions to the PC pornography. The subjects were 423 middle school boys in Pusan. The survey was executed from July 12 through October 30, 1999. The collected data were analyzed by SPSS WIN using the %, mean, ANOVA. The results of this study were as follows: 1. 79.4%(336 boys) were exposed to the PC pornography. 46.3%(196 boys) answered that they experienced the published pornography prior to the PC pornography. 2. 78.5%(333 boys) answered that they had their PC in their homes. This ratio revealed the higher level of possession. 67.6% said that their PC were set in their own rooms. 57.9% of the subject answered they experienced the Internet Communications. 68.6% of the subject said that they tried PC communications once or twice in a week. 38.5% of the subject expressed that they used their own PC for 1-2 hours in a day. Most of them(82.7%) enjoyed the PC games or entertainment programs. 81.3% of the subject answered that their school performance didn't show the progress after the use of their own PC. 78.3% of the subject answered that they acquired information. 45.2% of the subject answered that they made their friend through the Internet communications. 78.7% of the subject answered that the time of family dialogue decreased. 70.7% of the subject answered that the time of their TV watching decreased. 3. As for their post-exposure reactions the subject who were exposed to the PC Pornography showed the point 2.93 in the item 'pleasure'. The point of 'sexual impulses' was 2.81. But the point of 'anxiety' was 2.75, the point of 'dislike or disgust' was 2.62, the point of 'guilty' was 2.59. 4. According to the frequency, the motivation and the companionship on the exposure to PC Pornography, their post-exposure reaction scores showed differences significantly. Finally, the post-exposure reaction had relation to the frequency, the motivation, the companionship and the place (F=3.28 ~ 8.40, p=.012 ~ .000).

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.15 no.3
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• pp.163-168
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• 2015

In this paper, 433/865MHz dual band antenna is proposed by using IFA structure of a PCB antenna, the performance was improved by changing of the space between the feed point and short strip, varying the gap between the radiator and the ground plane and adding the branch line in the proposed antenna. To confirm the characteristics of the antenna parameters, HFSS from ANSYS Inc. was used for the analysis. RFID frequency band of ISO-18000-7 is 433MHz and EU-RFID frequency band of ISO-18000-6 is from 865.5 to 867.5MHz. Each of the 433/865MHz bandwidth of the proposed antenna is 5.2MHz and 18.2MHz. The maximum 433MHz antenna gain is -5.74dBi, the maximum 865MHz antenna gain is -3.36dBi. The Jig size of the proposed antenna is $60{\times}44{\times}1mm$ and the size of the antenna area $44{\times}21mm$. The results proved the possibility of the practical use on 433/865MHz by using the IFA structure that came from comparing and analyzing the measured and simulated data of the antenna.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2002.05a
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• pp.130-133
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• 2002

As a society advances, an aging phenomenon and many diseases which did not exist in old times are happening. Especially, in case of the aged patient, because we cant know the time the condition of the patients health become worse, the study of the Tele-information system has been actively carried out by the necessity of a persistent observation. A ECG signal a kind of a vital signals has been widely used to the medical information system as an usual clinical diagnosis for the patients who possess heart diseases. BlueTooth is a close range wireless communication technology which uses a wireless frequency 2.4GHz and has a high trust and self - error correction technology according to a low power consumption quality and a high-speed frequency hopping. This makes get a high trust concerning a data transmission than an existing modem. In addition, though wireless modem is restricted by a minimal of a wireless terminal, It will be possible to coincide with the function of the portable with the low power consumption quality by using Bluetooth. And as the system on a chip of module progresses, the possibility of the small size is present According to this, Bluetooth module transmits the medical information, which is input from the outside among the operations that use the Bluetooth to the Bluetooth module that is connected the host PC. And the system that the host PC transmits the medical information from the connected Bluetooth module to the Internet has once embedded. this study let the host PC embedded in advance of the existing system and transmit the medical information by the addition of the Tcp/Ip protocol stark under all embedded environments to internet.

• Journal of Korean Home Economics Education Association
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• v.33 no.4
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• pp.1-13
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• 2021

The purpose of this study is to identify trends and potential themes of research on consumption of children and adolescents for 20 years by analyzing keywords. The keywords of 869 studies on consumption of children and adolescents published in journals listed in Korean Citation Index were analyzed using text mining techniques. The most frequent keywords were found in the order of youth, youth consumers, consumer education, conspicuous consumption, consumption behavior, and character. As a result of analyzing the frequency of keywords by dividing into five-year periods, it was confirmed that the frequency of consumer education was significantly higher betwn 2006 and 2010. Research on ethical consumption has been active since 2011, and research has been conducted on various topics instead of without a prominent keyword during the most recent 5-year period. Looking at the keywords based on the TF-IDF, the keywords related to the environment and the Internet were the main keywords between 2001 and 2005. From 2006 to 2010, the TF-IDF values of media use, advertisement education, and Internet items were high. From 2011 to 2015, fair trade, green growth, green consumption, North Korean defector youths, social media, and from 2016 to 2020, text mining, sustainable development education, maker education, and the 2015 revised curriculum appeared as important themes. As a result of topic modeling, eight topics were derived: consumer education, mass media/peer culture, rational consumption, Hallyu/cultural industry, consumer competency, economic education, teaching and learning method, and eco-friendly/ethical consumption. As a result of network analysis, it was found that conspicuous consumption and consumer education are important topics in consumption research of children and adolescents.

• Journal of Internet Computing and Services
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• v.25 no.1
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• pp.109-121
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• 2024

In various manufacturing processes such as textiles and automobiles, when equipment breaks down or stops, the machines do not work, which leads to time and financial losses for the company. Therefore, it is important to detect equipment abnormalities in advance so that equipment failures can be predicted and repaired before they occur. Most equipment failures are caused by bearing failures, which are essential parts of equipment, and detection bearing anomaly is the essence of PHM(Prognostics and Health Management) research. In this paper, we propose a preprocessing algorithm called SWT-SVD, which analyzes vibration signals from bearings and apply it to an anomaly transformer, one of the time series anomaly detection model networks, to implement bearing anomaly detection model. Vibration signals from the bearing manufacturing process contain noise due to the real-time generation of sensor values. To reduce noise in vibration signals, we use the Stationary Wavelet Transform to extract frequency components and perform preprocessing to extract meaningful features through the Singular Value Decomposition algorithm. For experimental validation of the proposed SWT-SVD preprocessing method in the bearing anomaly detection model, we utilize the PHM-2012-Challenge dataset provided by the IEEE PHM Conference. The experimental results demonstrate significant performance with an accuracy of 0.98 and an F1-Score of 0.97. Additionally, to substantiate performance improvement, we conduct a comparative analysis with previous studies, confirming that the proposed preprocessing method outperforms previous preprocessing methods in terms of performance.

• International Journal of Computer Science & Network Security
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• v.21 no.5
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• pp.151-159
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• 2021

This article addresses the issue of finding optimal solutions using the information technologies of accounting and analysis in modern companies. The aim of the study is to reveal available information technologies for the needs of small, medium and large businesses operating in modern conditions. This goal is achieved by using systematization, comparison, and analysis of information, obtained under the survey and open management statistics. For the first time, the paper systematizes up-to-date information of 2021 about the most popular programs, online services, platforms and cloud services that are used to improve accounting and analytical processes in enterprises of various sizes. The main global trends in software development in terms of COVID-19 pandemic have been identified. In particular, the study defines the countries that occupy the leading positions in the informatization of business processes. An attempt was made to classify information technologies by their use by various volume of businesses. The analysis of research results of the Internet search query frequency regarding the use of information technologies enabled to determine the most popular software products worldwide. The peculiarities of information technologies, their advantages and disadvantages were examined and the common and distinctive features were compared. It was determined that for the new enterprises to implement information technologies, it is necessary to conduct a step-by-step study of all available software products. The software evaluation algorithm was described to help select the optimal software for the specific business processes. The paper also describes the way to solve the problem of using accounting and analysis software for the businesses of a specific kind of activity.

• Journal of the Korean Society of Clothing and Textiles
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• v.30 no.12 s.159
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• pp.1747-1758
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• 2006

Rapid development of the information technology has influenced on the changes in every sector of human environments. One prominent change in retail market is an increase of electronic stores, which has prompted practical and research interest in the product and store attributes that include consumer to purchase products from the electronic shopping. Therefore many marketers are paying much attention to the criteria of evaluating clothing and web service on internet shopping malls. The purpose of this study is to examine differences of clothing and web service criteria of consumer groups (High-Involvement & High-Ability, Low-Involvement & High-Ability, High-Involvement & Low-Ability, and Low-Involvement & Low-Ability) who are classified into consumer involvement and internet use ability. The subjects of this study were 305 people aged between 19 and 39s, living in Seoul and Gyeonggi-do area, and having experiences in buying products on the internet shopping. Statistical analyses used for this study were the frequency, percentage, factor analysis, ANOVA and Duncan test. The results of this study were as follows: Regarded on the criteria of evaluating clothing, the low different groups had significant differences in the esthetic, the quality performance and the extrinsic criterion. Both HIHA group and HILA group showed the similar results. They considered every criterion of evaluating clothing more important, compared with other groups. Regarded on the criteria of evaluating web service related to the low different groups, there were significant differences in the factors related to the shopping mall reliance, the product, the satisfaction after purchase, and the promotion and policy criterion. Both HIHA group and HILA group showed the similar results as well. They considered every criterion of evaluating web service more important, compared with other groups. In conclusion, HI groups perceive relatively more dangerous factors which can be occurred during internet shopping. Therefore, internet shopping malls need to provide clothing that can satisfy the HI groups as well as make efforts to remove the dangerous factors on the internet.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.14 no.1
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• pp.179-187
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• 2014

The underlay protocol is a cognitive radio method in which secondary or cognitive users use the same frequency without affecting the quality of service (QoS) for the primary users. In addition, because of the broadcast characteristics of the wireless environment, some nodes, which are called eavesdropper nodes, want to illegally receive information that is intended for other communication links. Hence, Physical Layer Security is applied considering the achievable secrecy rate (ASR) to prevent this from happening. In this paper, a performance analysis of the amplify-and-forward scheme under an interference constraint and Physical Layer Security is investigated in the cooperative communication mode. In this model, the relays use an amplify-and- forward method to help transmit signals from a source to a destination. The best relay is chosen using an opportunistic relay selection method, which is based on the end-to-end ASR. The system performance is evaluated in terms of the outage probability of the ASR. The lower and upper bounds of this probability, based on the global statistical channel state information (CSI), are derived in closed form. Our simulation results show that the system performance improves when the distances from the relays to the eavesdropper are larger than the distances from the relays to the destination, and the cognitive network is far enough from the primary user.

• Journal of Internet of Things and Convergence
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• v.7 no.4
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• pp.85-94
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• 2021

This study verified what differences in screen golf content characteristics, intention to reuse, customer satisfaction and economic value experienced by consumers according to the image feeling, expression method, and image color provided by screen golf graphic content. In addition, the purpose of this study was to analyze what kind of influence the content characteristics of screen golf have on the economic value and what kind of influence the intention to reuse and customer satisfaction have in this process. From September 1, 2021 to September 30, 2021, a survey of 225 copies of consumers using the screen golf course was conducted. For data processing, frequency analysis, factor analysis, reliability analysis, cluster analysis, chi-square analysis and 3-step mediated regression analysis were performed. The research results are as follows. First, the preferred image feeling showed a high level of clean and sophisticated feeling and the preferred expression method showed a high realistic image. In addition, the preferred image color showed a high level of green color. Second, there were differences in competitiveness, ease of use, sense of solidarity and realism according to the degree of consideration of graphic content and differences in consumer's intention to reuse, customer satisfaction, and economic value. Third, in the relationship between screen golf content characteristics and economic value, customer satisfaction and re-use intention had a mediating effect. Through this study, by providing basic data to derive the graphic design model of screen golf, the operating entity suggested a way to improve economic benefits and tried to contribute to the growth of the screen golf industry.