• Journal of the Institute of Electronics and Information Engineers
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• v.52 no.1
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• pp.148-154
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• 2015

Reports show that global system for mobile communication (GSM) mobile phones, or two-generation (2G) mobile phones, could affect functions of pacemakers and implantable cardioverter defibrillators (ICDs). In this study, we evaluated the effects of radio frequency electromagnetic fields (RF-EMFs) emitted by wideband code division multiple access (WCDMA) mobile phones, which were third-generation (3G) mobile phones, on pacemakers and ICDs. Five pacemakers and three ICDs were subjected to in-vitro test using a ECG simulator. We used a WCDMA module (average power : 0.25 W, frequency band : 1950 MHz) instead of a real WCDMA mobile phone. To assess the effects of the WCDMA module on pacemakers and ICDs, each implantable device was placed in close proximity (within 3 mm) to the WCDMA module for 5 min. As a result, no effects were observed on the five pacemakers and three ICDs for the RF-EMFs emitted by the WCDMA module. Because WCDMA mobile phones have the higher frequency band (1800-2200 MHz) and lower power output (0.01-0.25 W) than GSM moboile phone, the RF-EMFs emitted by WCDMA mobile phones do not affect patients with pacemaker or ICD.

• The Journal of the Korea Contents Association
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• v.16 no.4
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• pp.45-55
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• 2016

The purpose of this study was to identify the relation between mobile phone use and visual display terminal syndrome symptom experience in female students from middle school and high school. The convenience sample consisted of 349 female students in four schools. The data were collected from May to June in 2013 using VDTS Subjective Symptom Questionnaire. Descriptive statistics, Kruskal-Wallis test, and Mann-Whitney U test were used to analyze the data using SPSS 21.0. Almost all (96.3%) female students use mobile phone. Among them, 87.7% of the subjects experienced more than one VDTS symptom and the average score was $.39{\pm}.41$ in VDTS symptom experience. Eye related symptom was most experienced and musculoskeletal symptom was the highest in severity among five subdomain of VDTS symptoms. There were significant differences in VDTS symptom scores in accordance with posture, hours of use, and break type during mobile phone use. These findings suggest that the education program for adolescents would be necessary, and the development of checklist would be useful for adolescents to check themselves.

• Journal of Digital Convergence
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• v.14 no.12
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• pp.293-302
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• 2016

The study explores how academic strain, unhappiness, and mobile phone dependency among adolescents have changed over time. And we conducted the longitudinal and complex analysis on the influence of academic strain on unhappiness and mobile phone dependency in order to search the ways to prevent a vicious circle among them. We used general strain theory as a conceptual research frame and analysed the data of 1,589 respondents of the 2nd~4th Korean Children and Youth Panel with latent growth modeling. It was found that the levels of academic strain, unhappiness, and mobile phone dependency among adolescents were linearly increased across time. Academic strain initial status positively affected unhappiness initial status and both the initial status and change rate of mobile phone dependency. The change rate of unhappiness positively affected that of mobile phone dependency. Academic strain change rate positively influenced that of mobile phone dependency mediated by unhappiness change rate. We provided useful implications to academic activities, negative emotions, and mobile phone dependency for adolescents and suggested future studies about reasons of the changes of those variables.

• Korean Journal of Social Welfare Studies
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• v.47 no.3
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• pp.251-277
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• 2016

The purpose of this study was to examine the effects of adolescents' mobile phone dependency on depression and aggression and to identify mediating effects of parenting attitudes and peer relationships. This study used data from the 4th and 5th waves of 2010 KCYPS (Korean Children and Youth Panel Survey). Structural Equation Model(SEM) was conducted to examine the mediating effects of parenting attitudes and peer relationships. The results showed that adolescents' mobile phone dependency had positive effects on depression and aggression. In addition, the relationship between adolescents' mobile phone dependency and depression was partially mediated by parenting attitudes and peer relationships. The relationship between adolescents' mobile phone dependency and aggression was also partially mediated by parenting attitudes and peer relationships. Based on these findings, further suggestions are provided to reduce adolescents' depression and aggression by decreasing mobile phone dependency and improving parenting attitudes and peer relationships.

• Journal of Digital Convergence
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• v.15 no.1
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• pp.1-9
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• 2017

The purpose of this study is to investigate the differences of the mobile phone overuse by gender and school levels. For this study, 565 middle and high school students in Gyeonggi province answered the self-report survey, 253 students were extracted as an overuse group, and the data were analyzed by one-way MANOVA. The results showed that 'daily disturbance' was a common major factor in gender and school level difference and 'school life disturbance', 'with draw' and 'tolerance' were added in school level difference. Based on the results, this study suggested users' characteristics such as gender and school level should be taken into prevention and treatment of mobile phone overuse.

• TTA Journal
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• s.36
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• pp.95-104
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• 1994

간이형 휴대전화 시스템 실용화실험 협의회는 국내 전기통신 사업자, 통신장비 제조업체, 관련 정부기관 및 관련단체의 협조와 참여를 통하여 1993년 7월 6일 설립되었다. 이 협의회는 간이형 휴대전화 시스템(PHS)에 대한 실용화실험의 여러 형태에 관련된 정보의 교환을 조정하고, 실용화의 원활한 구현을 촉진하기 위하여 구성되었다. 이들의 활동을 통하여 협의회는 이 새로운 통신 서비스에 대한 공공의 합의를 토대로 실질적인 PHS의 개념을 설정하는 업무를 처리한다. 이 최종보고서는 협의회에 의해서 1993년 10월부터 1994년 10월까지 1년여 기간동안 일본 도처의 여러지역에서 실시된 실용화실험의 결과로 제출되었다. 이 보고서가 더 나은 PHS의 구현에 도움이 될 것을 희망한다.

• Digital Contents
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• no.10 s.149
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• pp.58-61
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• 2005

휴대전화의 모바일 뱅킹 기능과 모바일 증권 트레이딩 기능은 이제 낯선 개념이 아니다. 그 기능들을한 번도 사용해보지않은사람일지라도‘ 휴대전화로은행업무를볼수있다는거알아? 주식거래도하고?’라고말을 건네면‘ 당연히되는거아냐?’라고반문해온다. TV 모바일뱅킹CF에익숙해진탓일까? 아니면, 모바일만능시대이다보니모든게휴대전화에서일어나는게당연하게여겨지기때문일까? 이번호에서는‘ 당연한’개념인 모바일 금융을 다뤄 보고자 한다. 아직 모바일 금융의 대중화를 위해서는 넘어서야 할 몇몇 사항이 남아있긴 하지만, 이제‘ 당연한’서비스가 되기 위해 진일보하고 있는 모바일 금융을 남들보다 일찍 접하고 이를 통해재테크를할수있는기회를가졌으면한다.

• Korean Journal of Child Studies
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• v.29 no.4
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• pp.181-197
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• 2008

A mobile phone usage survey was administered to a nationwide sample of 3,617 adolescents. Major motivations of mobile phone usage were mobility/real-time connection, show off, information acquisition, entertainment, dialogue, schedule management, and advice. Maintenance of social relationship with the peer group was most important in mobile phone use. Motivations influenced mobile phone dependency : show off had the strongest influence on anxiety/paranoia followed by dialogue, entertainment, mobility/real-time connection. Without their phones, fashion-oriented adolescents showed mobile phone dependency and anxiety. Stronger dialogue and entertainment motivations were associated with weaker real time connection motivation and stronger paranoia symptoms. Mobile phone dependent adolescents had lower grades, showed lack of attention, had little dialogue with their parents and showed withdrawal from the peer group.

• Proceedings of the Korea Society of Information Technology Applications Conference
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• 2007.11a
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• pp.103-103
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• 2007

• Korean Journal of Cognitive Science
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• v.22 no.1
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• pp.1-18
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• 2011

With rapid spread of handheld devices like cellular or smart phones, a short message service (SMS) comes on the public as a communication means. SMS is very cheap and can be easily written down on the storage in order not to forget it, hence it is widely used to inform schedules (time and place). In this paper, we develop a system for automatically registering schedules extracted from SMS text messages. SMS text messages are very short and concise, but include a lot of Internet words like slangs and abbreviations. These have made it difficult to extract information on schedules from them. Also handheld devices have some limitations on computing power and storage and then applying general natural language processing modules like morphological analysis to the devices are somewhat hard. To relax these burdens, we extract schedule informations from SMS messages using machine learning methods like condition random field (CRF) without using any language processing modules and register the informations on the schedule management system of handheld devices. Our proposed automatic schedule registration system has implemented on Samsung Omnia phone for experiments.