• Journal of the Institute of Electronics Engineers of Korea TC
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• v.45 no.10
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• pp.90-98
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• 2008

PKI (Public Key Infrastructure) which is used for the security of E-commerce (Electronic-commerce) in wired internet is not suitable for the mobile phone because of the fundamental limitation of performance such as less memory and less powerful CPU. Therefore, we need to develop a wireless PKI (WPKI) that provides the similar security level as the wired PKI supporting mobile phone. In this paper, we propose a lightweight and secure Wireless Certificate Management Protocol (WCMP) that is executable to the mobile phone that has a constrained communication environment and limitation of performance, and show the implementation results of the scheme based on the mobile phone. We minimize data sizes processed in mobile phone, and optimize protocols for the certificate management. This results in the reduced module sizes to be able to install in mobile phone and shows as the same level as the wired CMP.

• The Journal of the Korea Contents Association
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• v.13 no.6
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• pp.412-424
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• 2013

Due to the rapid increase in mobile-phone use, various kinds of malfunctions have occurred recently. Among them, the mobile-phone addiction causes serious social problems. In particular, since teenagers are immature, they are easily addicted to new technology. In order to prevent from the mobile-phone addiction, a lot of research has been performed in various ways. This paper focuses on the differences in gender and time perspectives of adolescent and analyze the relationships between time perspectives and self-efficacy for preventing mobile-phone addiction. In order to achieve our research goals, we firstly survey on 1,224 secondary school students to analyze the gender differences about time perspectives. And then, we secondly survey on 269 high school students to examine the mediation role of self-efficacy between time perspectives and mobile-phone addiction by a structural equation model. Based on the results of our analyses, we provide an educational guide that can prevent mobile-phone addiction from secondary school students.

• Anxiety and mood
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• v.8 no.2
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• pp.127-132
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• 2012

Objective : This study aims to investigate the relationship between addictive mobile phone use and post-traumatic stress disorder (PTSD) symptoms in bullies who experienced school violence. Methods : The study subjects consisted of 97 adolescents in The Foundation for Preventing Youth Violence after school violence. The participants conducted self-report questionnaire for addictive mobile phone use and Impacted Event Scale-revised-Korean version (IES-R-K). Partial correlation and multiple logistic regressions were performed. Results : The scores related to addictive mobile phone use were correlated with total score (r=0.21, p=0.04), avoidance score (r=0.21, p=0.04) and intrusive score (r=0.26, p=0.01) related to PTSD symptoms on the IES-R-K. Intrusive score related to PTSD symptoms on the IES-R-K were significant risk factor for addictive mobile phone use (O.R=1.25, 95% CI=1.12-1.39). Conclusion : This data supports that PTSD intrusive symptoms could be predictable factor of addictive mobile phone use. An appropriate intervention about PTSD symptoms might play a useful role in preventing addictive mobile phone use in bullies of school violence.

• Proceedings of the IEEK Conference
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• 2005.11a
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• pp.1101-1104
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• 2005

As intelligence of robot is developed, consumer of robot changes by ordinary people. Intelligent service robot is produced to a target of ordinary people. It is risen that need the most service robot business. Among the control mobile robot because using network by real time. Do to appear on mobile phone LCD screen being transmitted image from device that acquire transmit of mobile phone user interface development and real time mobile robot in this study. Use the BREW that is Qualcomm's Mobile platform for mobile phone user interface development. Mobile phone JPEG compression function chooses excellent camera phone and display transmit image which send connection setting screen and mobile robot on LCD screen by real time. At the same time, materialize to make screen that can process button input that can control transfer of robot. Also, Relay Server used to help processing of protocol to control direction of mobile robot.

• Journal of Digital Convergence
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• v.4 no.2
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• pp.127-142
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• 2006

This paper uses a Mobilans case based on software system to derive the results of our study. Recently, the mobile phone payment entered its matured stage and became most frequently used payment method in all internet sites. And, in order to prepare for the future ubiquitous market, every mobile phone payment methods has different speed of development, market status and target segments in the market. This paper also discusses about the background and current status of Korean mobile phone payment market using SMS(Short Message Service) to purchase items on internet which is growing sharply every year. Also, we try find the key factors to succeed in this growing market. In addition to safety, delayed payment and the immediateness for use of mobile phone, we also suggest that a highly developed hardware system is an additional factor under the increased demands for the convenience with various applications.

• Journal of Korea Society of Digital Industry and Information Management
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• v.4 no.4
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• pp.63-69
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• 2008

Recently, every student would take lessons without knowing no lecture in campus life. And, If you are a university student, you tired a course to register in a crowded. For solving this problem, we choose the cellular phone. Nowadays peoples have one cellular phone to one person in korea. Using cellular phone, you can use cellular phone anywhere any time. In this paper, we studied mobile synthesis system using mobile cellular phone. According to use mobile campus system, the university and students can use easy an one to one service in ubiquitous.

• Transactions of Materials Processing
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• v.20 no.1
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• pp.54-59
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• 2011

Optical properties in injection molded plastic lenses for mobile phone camera have been simulated using commercial program, 3D TIMON. Four plastic lenses are being used in mobile phone camera. The quality of photographs taken by mobile phone camera is strongly depends upon optical characteristics of lenses. The variety of optical properties has been investigated according to the injection conditions through the computer simulation. Consequently optimal injection conditions for four lenses have been determined and simulation results of birefringence have been compared with experiments.

• The Journal of the Acoustical Society of Korea
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• v.19 no.6
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• pp.23-27
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• 2000

Noise can be defined as any undesired or loud sound. The sound level of mobile phone ring tones could be considered as noise if it is too loud on a specific situation. To classify a specific sound level of mobile phone ring tones as noise, it is useful to evaluate the mean opinion scores(MOS) on sound levels under some specific situations. The paper evaluates MOS on various sound levels (in dBA) of mobile phone ring tones, types of ring tone(bell/melody), and gender(male/female), location (street/office).

• Transactions of Materials Processing
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• v.15 no.1 s.82
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• pp.76-81
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• 2006

In this study, warpage characteristics of mobile phone cover through injection molding process were investigated using design of experiments in injection molding process. Warpage in plastic injection molding has a significant effect on quality of product. Effects of injection time, packing pressure, packing time, mold temperature and melt temperature on the warpage of mobile phone cover were considered by numerical analysis and experiment with Taguchi method. The degree of warpage for the injection molded part was measured by using three dimensional coordinate measurement machine. It was shown that temperature control factor has more significant effect on the warpage of mobile phone cover than pressure control factor.

• International Journal of Human Ecology
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• v.5 no.2
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• pp.93-110
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• 2004

The purpose of this study is to investigate the money management behavior according to the consumption value for consumers, especially for adolescents. Using 502 samples of middle school adolescents, a survey was conducted from May 10 to May 20, 2004. The main results were as follows: 1) The consumption value for adolescent consumers was categorized conspicuous-consumption value, brand-oriented value, mental-oriented value and advertising-dependent value. 2) Female adolescent, with more private spending money, with mobile phone, with importance on brand when purchasing mobile phone, paying more for using mobile phone, having conspicuous-consumption value, with more importance for brand when purchasing mobile phone and having more advertising-oriented value. Adolescent consumers with less private spending money, less payment for mobile phone and having mental-oriented value. 3) Female, with more educated mother, with less spending private money and having better money management behavior. 4) With less conspicuous-consumption value, more mental-oriented value, adolescent consumers have better for money management behavior.