• The Journal of Korean Society for School & Community Health Education
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• v.12 no.1
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• pp.45-58
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• 2011

Objectives: The purpose of this study is to analyze the fators affecting Internet addiction among adolescents in an area. Methods: By using cluster sampling, 2,479 participants representing 22 elementary school, 11 middle school, 7 high school students in a county of the Chungcheongnam-do. Data was analyzed by SPSS 12.0. using t-test, F-test, chi-square test, Pearson correlation coefficient and multiple regression. Results: Internet addiction positively correlated with high school students(dummy variable), Internet-connected computers in PC Game Room(dummy variable), Internet using time(weekday) and Internet using time(weekend). Internet addiction negatively correlated with Internet-connected computers in school(dummy variable), Internet-connected computers in friend's house(dummy variable). For the male students, Significant factors affecting Internet addiction were eating habits, Internet-connected computers in friend's house, Internet using time(weekend). For the female students, Internet using time(weekday) and Internet using time(weekend) were significant. For the elementary school students, Significant factors affecting Internet addiction were Internet using tine(weekday) and Internet using time(weekend). In the case of the middle school students, Internet using tine(weekday), Internet using time(weekend) and eating habits were significant. but, the high school students, Internet using time(weekend) was significant. Conclusions: Students who spend more time in the internet have higher tendency to become addicted to the internet. Therefore, it would be necessary to develop program to prevent internet addiction.

• International Journal of Fuzzy Logic and Intelligent Systems
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• v.2 no.3
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• pp.179-184
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• 2002

Recently, internet-based applications can be found easily in various felds. Internet-based telerobot system becomes one of important applications of internet. Among many important technological issues on the internet-based telerobot, time-delay is inherently critical problem to be solved. Time-delay is classified as micro time-delay and macro time-delay in this paper. Algorithms for compensation of path-error and time-error are proposed for the both types of time-delays using fuzzy logic since fuzzy logic is one of the best tools to represent expert's knowledge. Simulation results show the validity of the proposed algorithms.

• Journal of Institute of Control, Robotics and Systems
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• v.9 no.3
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• pp.196-203
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• 2003

Recent increase in accessibility to the internet makes it easy to use the internet-connected devices. The internet could allow any user can reach and command any device that is connected to the network. But these teleoperation systems using the internet connected device have several problems such as the network time delay, data loss and development cost of an application for the communication with each other. One feasible solution is to use local and external network line for the network time delay, transmission control protocol for data loss and Java language to reduce the development period and cost. In this study, web-based remote control system using Java language is newly proposed and implemented to a pneumatic servo control system to solve the time delay, data loss and development cost. We have conducted several experiments using pneumatic rodless cylinder through the internet and verified that the proposed remote control system was very effective.

• Korean Journal of Human Ecology
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• v.6 no.1
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• pp.1-13
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• 2003

This study attempts to investigate attitude toward internet shopping. internet purchase behavior. and purchase satisfaction of college student consumers. The data used for this study were collected from 361 college students who is living the southern part of Korea. and purchased goods and services on the internet at least one time during the previous 12 months. in Autumn, 2001. Data analysis were carried out using SAS package. Statistics used for data analysis were Cronbach'$\alpha$, Pearson's correlation analysis, and multiple regression. The results were summarized as follows : First, college student consumers in general are favorable to the internet shopping. The variable that has significant influence on the attitude toward the internet shopping was the web searching competence. Second, the variables that have significant influence on the internet purchases were the number of site visits, internet using time, credit card possession. personal income, and web searching competence. Third, the variables that have significant influence on the amount of internet purchases were personal income, internet using time, number of site visits. and credit card possession. Fourth, the variables that have significant influence on the satisfaction with internet shopping were internet shopping attitude and web searching competence.

• International Journal of Internet, Broadcasting and Communication
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• v.8 no.2
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• pp.75-80
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• 2016

Objectives : The objective of this study is to examine the experiences of Internet game experience targeting to University students in Korea. Research topics was "What is meaning of internet game to the University students?" Methods : Classical phenomenology underpinned this study. Seven qualitative studies of University students were conducted between 20 and 23 years old. Semi-structured interviews were conducted. Interviews were audio recorded and transcribed verbatim. Phenomenological thematic analysis of data was undertaken. Results : The findings pivot around three interconnected themes :[Expectations for the emotional needs], [Spend time in the cyberspace], [Relieve stress throughout the game], [Instead of satisfaction from virtual reality], [Internet gaming repeat and desires]. The basic need for getting into internet game was [satisfaction from virtual reality was identified]. While internet games was eliminated stress, [Expectations for the emotional needs] and [Spend time in the cyberspace] were the catalyst that makes them repeatedly getting into Internet the game. Based on the result, I suggest that Internet gaming should be recognized as a tool to relieve stress for college students, But it is not satisfied with the reality in virtual space. Therefore, the strategy must be to recognize reality accompanying. And Using a lot of time in cyberspace make them cause of internet game addiction. Therefore, it requires a systematic strategy for the Internet using time limits. Also the emotional needs met were motivated to repeat an Internet game. So another way to meet the emotional needs to college students should be sought.

• Korean Journal of Human Ecology
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• v.13 no.6
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• pp.861-874
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• 2004

The goal of this study is to investigate the relationship between maternal rearing behavior characteristics and elementary school children's Internet use, and to utilize the results as the basic data to develop a program, in which parents learn how to educate their children for better use of the Internet. The subjects were 713 children whose grade are in fourth through sixth in an elementary school. Data were obtained with questionnaires. The instruments employed were Children's Internet Use and Addiction, and maternal rearing behavior characteristics-Rational Guidance, Affection, Authoritarian Control, Overprotection, Achievement Encouragement, and Active Involvement-Scales. The data were analyzed with the SPSS program. They were analyzed by Frequency, Percentage, ANOVA, Duncan's test, and Pearson correlation. The results of this study are as follows: First, 30.2% of the subjects has used Internet for more than three years. 55.6% of the subjects spend less than an hour per day in using the Internet. The two major types of Internet use were playing games(49.9%) and sending e-mails(25.4%). The main reason for playing Internet games was escape from stress(34.7%). 34.5% of the subjects also said that their parents usually encourage them to use the Internet. Second, maternal affection, authoritarian control, and active involvement were significantly different in the types of Internet use. Maternal authoritarian control and overprotection were significantly different in the reasons of doing Internet game. The rational guidance and active involvement of mothers were correlated negatively with children's Internet using time, but their authoritarian control and overprotection were correlated positively with children's Internet using time. Maternal overprotection was correlated positively with parents' encouragement level in the Internet use. Third, the rational guidance, affection, and active involvement of mothers were correlated negatively with children's Internet addiction. In the other hand, maternal authoritarian control and overprotection were correlated positively with children's Internet addiction. Lastly, children's Internet addiction was significantly different by the types of Internet Use and the reasons for doing internet game. Children's Internet using time was correlated positively with children's Internet addiction.

• International journal of advanced smart convergence
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• v.9 no.1
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• pp.109-112
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• 2020

Many devices are connected on the internet to give functionalities for interconnected services. In 2020', The number of devices connected to the internet will be reached 5.8 billion. Moreover, many connected service provider such as Google and Amazon, suggests edge computing and mesh networks to cope with this situation which the many devices completely connected on their networks. This paper introduces the current state of the introduction of the wireless mesh network and edge cloud in order to efficiently manage a large number of nodes in the exploding Internet of Things (IoT) network and introduces the existing Network Time Protocol (NTP). On the basis of this, we propose a relatively accurate time synchronization method, especially in heterogeneous mesh networks. Using this NTP, multiple time coordinators can be placed in a mesh network to find the delay error using the average delay time and the delay time of the time coordinator. Therefore, accurate time can be synchronized when implementing IoT, remote metering, and real-time media streaming using IoT mesh network.

• Journal of Preventive Medicine and Public Health
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• v.45 no.1
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• pp.37-46
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• 2012

Objectives: This study was performed to consider the association between Internet using time for non-educational purposes and adolescent health, and to examine how health status differs between Internet users and non-users. Methods: We analyzed 2009 data from the Korea Adolescent Risk Behavior Web-Based Survey, conducted on a nationally representative sample of students in grades 7 to 12. A total of 75 066 adolescents were categorized into four groups according to their Internet using time excluding using for educational purposes: non-Internet users (NIUs), occasional Internet users (OIUs) (<1 h/d), moderate Internet users (MIUs) (${\geq}1$ and <2 h/d), and heavy Internet users (HIUs) (${\geq}2$ h/d). Health factors included eight health risk behavior indices, four mental health indices and six physical health indices. Results: The distribution of Internet use was as follows: NIUs 17.4%, OIUs 68.1%, MIUs 12.7%, and HIUs 1.7%. In multivariate analysis, using OIUs as a reference, U- or J-shaped associations were observed for five health risk behavior indices (current smoking, current drinking, drug abuse, sexual intercourse, sedentary behavior on weekdays) and four mental health indices (stressed, depressed, suicidal ideation, attempted suicide) in both genders. After removing confounding effects, including age, region, school type, subjective school record, subjective economic status, presence of parents, living with family, and sedentary behavior, these associations were still observed. Conclusions: Health professionals should consider both Internet non-users (for non-educational purposes) and heavy users to be high-risk groups in terms of health status. Also, more well-designed studies are needed to clarify what factors are working in these nonlinear associations.

• International Journal of Precision Engineering and Manufacturing
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• v.6 no.3
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• pp.29-36
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• 2005

With the rapid growth of the Internet, the Internet-based robot has been realized by connecting off-line robot to the Internet. However, because the Internet is often irregular and unreliable, the varying time delay in data transmission is a significant problem for the construction of the Internet-based robot system. Thus, this paper is concerned with the development of an Internet-based robot system, which is insensitive to the Internet time delay. For this purpose, the PPS (Position Prediction Simulator) is suggested and implemented on the system. The PPS consists of two parts : the robot position prediction part and the projective virtual scene part. In the robot position prediction part, the robot position is predicted for more accurate operation of the mobile robot, based on the time at which the user's command reaches the robot system. The projective virtual scene part shows the 3D visual information of a remote site, which is obtained through image processing and position prediction. For the verification of this proposed PPS, the robot was moved to follow the planned path under the various network traffic conditions. The simulation and experimental results showed that the path error of the robot motion could be reduced using the developed PPS.

• The KIPS Transactions:PartC
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• v.10C no.6
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• pp.711-716
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• 2003

We propose a new Interet time synchronization model using danamic linear model and introduce the characteristics of internet transmission delays. SNTP(Simple Network Time Protocol) has been widely used as a time synchronization method on the Internet. While SNTP provides a very simple usage, SNTP may not provide the stable services, since SNTP does not consider the several essential error factors. In order to overcome the instabitily of SNTP, we analyze the process of time estimation of SNTP and find the difference between forward transmission delay and backward transmission delay operates the main error on the estimation of an time offset.