• 대한인간공학회지
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• 제26권2호
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• pp.15-20
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• 2007

The purpose of this study is to compare assessment techniques for Korean characters entry methods of mobile phones. This study was performed based on survey of relevant existing studies. The assessment techniques were classified into three: 1) predicting entry time using conceptual models such as Fitts' law, Hick-Hyman's law and KLM-GOMS model (conceptual model); 2) counting the number of pressing button(number of pressing button); and 3) measuring performance or rating subjective measures using real mobile phones(real mobile phone). The comparison revealed that the assessment results were different depending upon the techniques used. The results from the conceptual model using only Fitts' law and the number of pressing button were opposite to those from techniques of the real mobile phone and conceptual model using Fitts' and Hick-Hyman's laws. Based on this result and suggestions provided by the literature, it is recommended that for more precisely assessing interfaces of mobile phones such as Korean characters entry method, real mobile phones be used instead of the conceptual models.

• 디지털융복합연구
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• 제13권8호
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• pp.267-279
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• 2015

본 연구는 초등학생의 휴대전화 중독적 사용과 학습활동의 종단적 관계를 분석함으로써 (1)시간의 경과에 따른 휴대전화 중독적 사용과 학습활동의 변화와 (2)상기 두 변수 간의 관계 방향성을 검증하고, (3)성별 간 다집단 복합 분석을 수행하였다. 이를 위하여 제 1~3차 한국아동 청소년패널 초4 데이터와 자기회귀교차지연모형 분석을 사용하였다. 분석 결과, 시간의 경과에 따라 초등학생의 휴대전화 중독적 사용과 학습활동은 지속적으로 정적 영향을 미치고, 이전 시점의 휴대전화 중독적 사용이 이후 시점의 학습활동에 부적으로 영향을 미치는 것으로 나타났다. 단, 학습활동은 휴대전화 중독적 사용에 종단적으로 유의한 영향을 미치지 않았고, 두 변수 간 종단적 관계 검정 결과에 대한 성별 간 차이는 유의하지 않았다. 본 연구는 연구결과를 바탕으로 초등학생의 휴대전화 중독적 사용 방지를 위한 지침 마련에 유용한 기초자료를 제공하였다.

• Asian Pacific Journal of Cancer Prevention
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• 제13권11호
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• pp.5857-5863
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• 2012

Introduction: Mobile phones are in extensive use worldwide and concerns regarding their role in tumor formation were raised. Over the years multiple studies were published in order to investigate this issue using several approaches. The current study looks at secular trends of brain gliomas (low and high grade) incidence and changes in tumor's laterality over 30 years in a population extensively using this technology with a possible correlation to the spread of use of mobile phones. Materials and Methods: All brain gliomas that were diagnosed from 1980-2009 were included and subdivided into two groups - low and high grade. Secular and periodic time trend analyses of incidence rates and changes in laterality were performed. Preferred side of head using mobile phones was assessed with a questionnaire in a sample of adult individuals. Results: A decrease in incidence of low grade giomas (LGG) that correlated with introduction of mobile technology was found from 2.57, 2.34 and 2.79 for every 100,000 in the period 1980 to the end of 1994 to 1.72, 1.82 and 1.57, respectively, over the last three 5-years periods (1995-2009). High-grade glioma incidences increased significantly from 1980-2009 but in the period after mobile phones were introduced (1994-2009) a lower, non significant, rate of increase was observed in males and a lower one (significant) in females. A shift towards left sided tumor location for all adult gliomas combined and separately for LGG and HGG was noted from 1995 onward. The shift was more marked for those who were diagnosed in ages 20-49 (p=0.03). Conclusions: We found a statistically significant decrease in LGG's over 30-years period that correlates with introducing of mobile phones technology and a shift in laterality towards left-sided tumors, the latter occurred in both low and high-grade gliomas.

• 대한인간공학회지
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• 제30권1호
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• pp.265-273
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• 2011

Objective: The aim of this study is to investigate the attributing factors influencing usability of the mobile phones specifically designed for the elderly users. Efforts to identify factors that cause usability problems for the elderly users in using mobile phones can provide the groundwork for changes aimed at usability enhancement and design of interfaces of mobile phones. Background: It became important to understand the behaviors and tendencies of the elderly in communication as the society became older. The problems in digital divide is contributed to mainly lack of understanding in terms of the use pattern of the elderly and lack of consideration of their characteristics in designing user interfaces of most ICT devices. Method: A total of 30 elderly users who were over 65 years in age participated in usability evaluation test experiment and performed seven different tasks using a widely accepted model of universally designed mobile phone. Their performance was compared with that of contrast group that consisted of 10 younger participants who were on their 20s. Results: It was found that the elderly users had hard times in using mobile phones, especially in keypad manipulation among search, understanding, and manipulation subtasks. Conclusion: Older users seemed to have difficulty in all the subtasks of search, recognition, and manipulation. It was suggested that designers of mobile phones need to give careful consideration into designing visual interfaces for search tasks and keypads for easier control and input for the elderly users. Application: The study is expected to provide guidelines for the universal design of mobile phones and their interfaces for enhancing usability of the mobile phone for elderly users.

• 한국컴퓨터정보학회논문지
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• 제25권10호
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• pp.231-240
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• 2020

이미 세계 여러나라는 핸드폰 전자파의 위험성을 경고하며 조치를 실시하여왔다. 반면 우리나라는 휴대폰 사용으로 인한 문제보다 학생들조차 핸드폰을 사용하지 못하게 하면 인권침해라고 항의하는 분위기이다. 인간의 뇌세포도 핸드폰 전자파에 더 많이 노출되고 있어 인체의 유해가능성에 대해 세계 여러나라에서 연구하고 있으며 최근의 연구한 발표결과들은 강력히 경고하고 있다. 현재 국내의 전자파 등급표시로는 국민에게 경각심을 불러일으키기에는 너무나 부족하다. IT 강국이라는 명성에 발맞추어 국립 전자파연구센터를 조직·운영하고 일반대중에게 핸드폰 전자파의 유해성을 경고하고 업계에 직접적인 의무를 부과할 수 있는 전파법제의 개정이 필요하다고 생각된다.

• 한국산업융합학회 논문집
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• 제10권3호
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• pp.171-177
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• 2007

It is well known that mobile phones have been a indispensable communication tool for human life. The spiral springs are used as the main component of the semi-auto sliding mechanism of mobile phones. The characteristic of axiomatic approach is scientific and analytical method, and axiomatic approach is different from other design methods in offering the systematic method at an early stage of design. The axiomatic approach could determine design parameter and arrange the order of design and estimate the optimum design in good order. In axiomatic approach, the composition is divided by customer requirement, functional requirement, design parameter, and design matrix in large portion. This paper presents design in sliding mechanism for mobile phones by finite element method and axiomatic design.

• 한국컴퓨터정보학회논문지
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• 제22권4호
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• pp.91-97
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• 2017

In this paper, we propose a Recently, the use of Smart phones surge in youth the youth are becoming a big addiction social problems Mobile Messenger. The prevalence of Smart phones is Mobile Messenger, access time, spatial constraints for assured. As a result, pc room, with a focus on traditional Internet addiction is to be reduced, whereas with a focus on Mobile Messenger Smartphone addiction level is rapidly on the rise. Korea information agency of Internet addiction and mobile addiction risk appeared to be well over 10 percent of the rate of 35% is gaming and mobile addiction unfolds exemplifies the seriousness of Messenger. Addiction is the individual's psychosocial problems such as negative consequences can result, causing the addiction, because it is necessary for an understanding of the mechanism. In this study, Mobile Messenger, the leading factors affecting the addiction said. Mobile Messenger is a major factor causing the addiction habit and consider the user's satisfaction. And social relations and the formation of plougastel Wu Mobile Messenger and its impact on the cause of addiction.

• Environmental Analysis Health and Toxicology
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• 제30권
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• pp.15.1-15.11
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• 2015

Objectives There has been a growing concern about the possible carcinogenic effects of the electromagnetic radiofrequency fields emitted from mobile phones. The purpose of this study was to investigate the association between mobile phone use and the development of gliomas in Korea. Methods Our study methods were based on the International Interphone study that aimed to evaluate possible adverse effects of mobile phone use. This study included 285 histologically-confirmed Korean patients 15 to 69 years of age, with gliomas diagnosed between 2002 and 2007 in 9 hospitals. The 285 individually matched controls were healthy individuals that had their medical check-up in the same hospitals. Unconditional logistic regression was used to calculate the adjusted odds ratios (aORs) and 95% confidence intervals (CIs) for use of mobile phones. Results For the entire group, no significant relationship was investigated between gliomas and regular use of mobile phones, types of mobile phones, lifetime years of use, monthly service fee, and the other exposure indices. Analyses restricted to self-respondents showed similar results. For ipsilateral users, whose the body side for usual mobile phone use match the location of glioma, the aORs (95% CIs) for lifetime years of use and cumulative hours of use were 1.25 (0.55 to 2.88) and 1.77 (0.32 to 1.84), respectively. However, the contralateral users showed slightly lower risk than ipsilateral users. Conclusions Our results do not support the hypothesis that the use of mobile phones increases the risk of glioma; however, we found a non-significant increase in risk among ipsilateral users. These findings suggest further evaluation for glioma risk among longterm mobile phone users.

• 한국전자파학회:학술대회논문집
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• 한국전자파학회 2002년도 종합학술발표회 논문집 Vol.12 No.1
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• pp.232-236
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• 2002

In this paper, a new compact PIFA, applicable to PCS system, is described. The central aim in design is to broaden the bandwidth within limited height of mobile phones. To overcome the narrow bandwidth characteristics, which is typical of a patch antenna, tapered type radiation patch is employed. The antenna is designed using CST microwave studio and its characteristics are compared with a basic PIFA with similar volume.

• 한국환경보건학회지
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• 제42권4호
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• pp.255-265
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• 2016

Objectives: Mobile phones have become one of the most essential accessories in daily life. However, they may act as reservoir of infectious pathogens if they are used without hygienic practices in their handling. Therefore, this study aimed to isolate food-borne pathogens from mobile phones and investigate the characteristics of toxin genes and antibiotic susceptibility patterns. Methods: A total of 146 mobile phones were collected from 83 middle- and 63 high-school students in Busan. The surfaces of the mobile phones were aseptically swabbed. Results: Among the food-borne pathogens, Staphylococcus aureus, Bacillus cereus and Escherichia coli were detected in 26 (17.8%), 20 (13.7%) and four (2.7%) samples, respectively. There were no statistically significant differences according to school level, gender or phone type. None of four E. coli strains had pathogenic toxic genes. All of the B. cereus strains carried at least three different toxin genes among the nine enterotoxin and emetic toxin genes. Three out of 20 B. cereus strains (15%) possessed emetic toxin genes, which are rarely detected in food-poisoning cases in Korea. Among the 26 strains of S. aureus, the detection rate of staphylococcal enterotoxin genes, toxic shock syndrome toxin (tsst) and factors essential for methicillin resistance (femA) were 84.6%, 7.7% and 100%, respectively. In the antibiotic susceptibility test, there was no methicillin-resistant S. aureus (MRSA) or vancomycin-resistant S. aureus (VRSA). Conclusion: The results show that students' mobile phones in Busan were contaminated by food-borne pathogens which carried various toxic genes. Therefore, regular phone disinfection and hand hygiene is important in order to reduce cross-contamination.