• 한국화재소방학회논문지
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• 제25권6호
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• pp.21-26
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• 2011

본 논문에서는 에너지원에 따른 이동전화기(SCH_W830) 배터리의 소손 패턴을 제시함으로써 소비자분쟁 해결의 자료로 활용하고자 한다. 실험이 진행될 때의 주위 온도는 $22{\pm}2^{\circ}C$, 습도는 40~60 %를 유지함으로써 신뢰성을 확보하였다. 실험에 사용된 이동전화기의 배터리 전압은 양극(+)과 음극 (1)(-) 사이의 전압은 4.19 V이며, 양극(+)과 음극 (2)(-) 사이의 전압은 4.18 V로 측정되었다. 일반화염 인가에 의한 이동 전화기의 난연성 시험은 한국산업규격(KS)을 적용하였으며, 일반화염이 30 sec 동안 외함에 인가되어도 내장된 배터리의 소손은 없는 것으로 확인되었다. 생리 식염수(NaCl, 0.9%)에 이동전화기를 180 sec 침수시킨 결과 배터리 단자 사이에 누설전류에 의한 발열로 탄화 및 용융이 발생한 흔적을 확인할 수 있었다. 전자레인지(MWO)를 이용하여 70 sec 동안 이동전화기를 가열하면 금속홀더, 충전용 커넥터, 안테나 등이 내장된 부분에서 용융 및 변색이 확인되며, 그 밖의 부분은 특이사항이 없는 것을 알 수 있다. 즉, 인가된 에너지원의 종류에 따라 이동전화기 외형의 탄화, 내장된 금속 및 유전체, 배터리 단자대의 손상 및 변형 등이 다르게 발생하지만 전압은 비교적 일정한 특성을 보이는 것으로 보아 연소의 확산 패턴, 금속의 용융 및 변형 부분의 특성을 종합적으로 고려하여 해석하면 소손 원인 판정이 가능하다.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2004년도 ICCAS
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• pp.181-184
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• 2004

There are reports showing that electromagnetic fields (EMFs) emitted at non-thermal levels may be associated with biological alterations in target cells. In this study it is objected to assess the potential influences of EMFs produced by cellular phones on fetal heart rate. Non Stress Test (NST) is a widely used method of fetal monitoring and assessing fetal health and well-being. Sixty volunteers with uncomplicated term pregnancies were studied by a Spacelabs AM-67 Doppler ultrasound monitor. Fetal Heart Rate recordings were obtained while there were no Cellular Phone around for 10 minutes. Afterwards, all patients were exposed to EMFs for 10 minutes. NST was performed while they were holding the CP on stand-by mode and then on dialing mode, each for 5 minutes. The recordings were analyzed with respect to baseline heart rate, accelerations and decelerations. The Wilcoxon matched-pairs signed-ranks test was used to compare these variables. The results indicate that EMFs emitted by CP do not cause any demonstrable effects on baseline FHR, acceleration or deceleration.

• 가정과삶의질연구
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• 제31권6호
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• pp.83-96
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• 2013

The aim of this study was to identify the differences in cellular phone dependency and its use levels of usage purposes according to children's gender, and also to analyze the differences in individual and interpersonal relations development due to cellular phone dependency in children based on gender. Using the first year data of the Korean Child and Youth Panel Survey(KCYPS) 2010, this study analyzed 1,604 fourth graders who have their own cellular phones. For statistical analysis, descriptive statistics were calculated and mean difference analyses were conducted. The results showed that there was no difference between boys and girls in cellular phone dependency. The girls' total phone use level was higher than that of boys and meaningful gender differences in the phone use levels were found in the five phone usage purposes. In both boys and girls, the higher phone dependency groups demonstrated higher levels of phone use in more than eight usage purposes, lower self-resilience and self-regulating learning ability, and less positive peer and teacher relations. These findings show the importance of being concerned about and educating children in the fourth grade about the proper uses of cellular phones.

• Water Engineering Research
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• 제4권4호
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• pp.187-192
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• 2003

The rainfall observation systems have largely been improved in Japan. The Japan Meteorological Agency, prefecture governments, and other administrative bodies have also increased the number of rain gauges thru out the country. The density of observatories is now one per several $\km^2$. Heavy rainfall information systems have been improved. Besides it, the Internet was popularized in the late 1990s, and has been used to transmit data of heavy rainfall. Internet accessible cellular phones have been popular in Japan since 1999. Such phones are expected to be useful in the field of disaster warning announcements, because they can automatically notify users bye-mail of pending disasters. The use of the Internet during natural disasters is groundbreaking in Japan today. However, in order to use disaster information effectively on Internet it is necessary to investigate how to use the information during the rainfall disaster. Therefore in our study we suggest methods on the effective construction and their use of information technology on Internet.

• 한국전자파학회논문지
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• 제12권2호
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• pp.165-175
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• 2001

본 논문에서는 집중정수형 아이솔레이터의 특성분석을 위하여 페라이트 포화자계, 외부 DC자계, 스트립선로 규격등을 고려한 산란행렬을 이용하여 프로그램을 작성하여 정량적으로 분석하였으며, 이동통신 단말기에 사용할 수 있는 소형 아이솔레이터를 설계하고, 설계된 최적 피라미터를 이용하여 셀룰라 단말기용 소형 아이솔레이터를 제작하고 실험하였다. 수치해석 결과 외부, R, C 스트립선로 길이와 폭, 페라이트 두께, 포화자화에 의해서 임피던스와 산란계수와 위상특성이 민감하게 변화함을 확인하였다. 최적화된 프로그램을 이용하여 셀룰라, PCS 단말기용 소형 아이솔레이터의 규격을 제시하였으며, 셀룰라 단말기용 아이솔레이터를 제작 실험하여 삽입손실 0.7 dB 이하, 반사손실 20 dB 이상, 격리도 20dB에서 밴드폭이 44MHz로 측정되여, 기존의 제품에 비하여 우수한 특성을 가지고 있음을 확인하였다.

• 대한임상검사과학회지
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• 제44권3호
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• pp.118-123
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• 2012

Nosocomial infection and community-acquired infection with Staphylococcus aureus, especially methicillin-resistant S. aureus (MRSA), has become a strong concern in human body sites and related effects. The aim of this study is investigate the isolation rate of MRSA from nasal cavity inferior regions and cellular phones to assess the risk factor of nosocomial infection and community-acquired infection. 34.7% and 37.2% isolates were MRSA from the nasal cavity inferior regions and cellular phones according to a Mannitol salt agar (added oxacillin $6{\mu}g/mL$) culture and PCR according to S. aureus specific 16S rRNA and mecA primers. Thus, the distribution of S. aureus and the isolation rate of MRSA represent a very high risk factor regards nosocomial infection and community-acquired infection.

• 안보군사학연구
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• 통권9호
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• pp.257-282
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• 2011

In this paper, we propose an architecture design of military operation system utilizing cellular networks. The main contribution of this paper is to provide a cost-effective military operation solution for ground forces, which is based on IT(information technology). By employing the cellular phones of officers' and non-commissioned officers' as the tools of operational communication, the proposed system can be constructed in the minimum duration and be built on the four components: command and control system, gateway, security system, and terminal(cell phone). This system is most effective for the warfare of limited area, but the effectiveness does not decrease under the total war covering the whole land of Korea. For the environmental change of near future, expanded architecture is also provided to utilize the functionalities of smart phones.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2007년도 춘계학술대회 논문집
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• pp.60-65
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• 2007

According to the customers' demands, cellular phones are getting thinner and thinner in spite that their functions are getting more complex and flexible. Based on this trend, we are willing to propose new design of ultra slim cellular phone with multi-hinges which can provide thinner feature and wider active area than the current merchandised one. To make it come true, smaller and stronger mechanical parts would be necessary and more researches would be carried out in the near future. Moreover, the new frame of ultra slim cellular phone has the problem in heat propagation due to its thin feature and multi function. In this paper, slim heat-spreader would be proposed as a candidate to resolve the problem of heat transfer in the new cellular phone. To investigate the applicability of heat-spreader to cellular phones, prototypes were fabricated and verified.

• 한국생산제조학회지
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• 제23권6호
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• pp.580-589
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• 2014

Demands for automation in the cell production process of IT products are becoming increasingly sophisticated. In particular, the dual-arm robot has drawn attention as a solution because it has a flexibility and works similarly to humans. In this paper, we propose an automation system for cellular phone packing processes using two dual-arm robots. Applied robots are designed with specifications to meet the requirements of cellular phone packing jobs. In addition, a robotic cell production system is proposed by applying a method of task allocation for efficient packing of cellular phones. Specifically, a task is assigned to reduce takt-time and to avoid collision between two robots. Finally, we discuss some experimental results that include the packing job of five unit boxes with seven kinds of accessories.

• 한국전자파학회논문지
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• 제16권1호
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• pp.84-91
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• 2005

본 논문에서는 PIFA(Planar Inverted F Antenna)의 방사부에 H형 슬릿을 부가하여 이중대 역 휴대이동전화기의 안테나 특성에 관하여 연구하였다. 안테나 방사부에 위치한 슬릿의 형태에 의하여 안테나의 임피던스의 리액턴스 성분에 영향과 공진 메카니즘을 변형함으로써 안테나의 공진특성에 영향을 준다. 그러므로 안테나는 이중대역(셀룰라 대역, 한국형 PCS 대역)에서 공진하며, 슬릿의 길이와 모양에 의해서 안테나의 대역폭, 입력 임피던스, 방사패턴 등에 영향을 미친다. 따라서 본 논문에서 제시한 이론의 타당성 및 객관성을 증명하기 위해서 H형의 슬릿을 이용하여 4종류의 안테나를 제작하여 실험한 결과 반사손실의 -5 dB 대역폭은 셀룰라 대역과 한국형 PCS 대역을 만족하였고, 안테나 이득은 약 -8$\~$-1 dB이며, x, y 편파에 대한 방사패턴은 대체적으로 전방향 방사패턴을 형성하였다. 따라서 본 논문의 결과를 이용함으로써 단말기용 내장용 안테나로 사용할 수 있음을 확인하였다.