• 한국공간구조학회논문집
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• 제19권1호
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• pp.101-108
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• 2019

Recently, measuring instruments for SHM of structures has been developed. In general, the wireless transmission of sensor signals, compared to its wired counterpart, is preferable due to the absence of triboelectric noise and elimination of the requirement of a cumbersome cable. However, the low-cost wireless MEMS sensor has high noise density and transmits the signal wirelessly, so data transmission delay occurs during measurement. Therefore, the footbridges that was previously measured by a mobile phone in 2014 was remeasured using G-Link-200, iPad and iPhone to compare their performance.

• 대한임베디드공학회논문지
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• 제14권3호
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• pp.143-150
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• 2019

In this paper, we have developed a module that prevents a driver from using mobile phone while driving. The module is equipped with a vibration sensor to determine if the vehicle is running, a BLE module to transmit the status of the module and a speaker to transmit audible/unaudible sound to the mobile terminal where GUI application is installed. If the vehicle is judged to be moving, the application is activated and the touch function of the mobile phone is blocked. Other data are also transmitted depending on the state of the module, which informs forced module removal, battery failure, or sleep mode of the module.

• 한국경영과학회지
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• 제34권4호
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• pp.185-204
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• 2009

The USIM(universal subscriber identity module)-unlock introducing in July 1, 2008 might be led to a significant change that mobile service provider's dominance is considerably dispersed to the handset manufacturer and distributor. Under USIM-unlock environment, mobile service provider, handset manufacturer, and distributor have to make their decisions on their handset distribution channel strategies: the closed distribution channel strategy or the open distribution channel strategy. The change of distribution channel strategy between members in distribution channel can be understood as a matter of strategy choice, and we have developed a theoretical model and analyzed how to make a decision for the member's optimal distribution strategy based on 3-person game model between members of mobile phone distribution channel, under both of '1 subscriber-1 handset' and '1 subscriber-multiple handset' assumptions. Under '1 subscriber-1 handset' assumption, the closed strategy controlled by mobile service provider is all players' optimal solution because the maximum size of the mobile phone market is limited by subscribers. But, as total expected profit by the handset and distribution subsides is a deficit, mobile service provider have to choose the open strategy and consider the conversion to MNO(mobile network operator). Under '1 subscriber-multiple handset' assumption, mobile service provider is trying to find the way how to lock-in its service and mobile phone and how to maximize ARPU(average revenue per unit), while handset manufacturer and distributor have to look for the way how to maximize the mobile phone market using their own marketing efforts, because it is expected that total mobile handset demand for the open market is bigger than demand for the closed market under '1 subscriber-multiple handset' assumption.

• 한국전자파학회논문지
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• 제26권3호
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• pp.248-256
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• 2015

본 논문에서는 4G 이동 통신을 위한 메탈 폰용 보조 슬롯 하이브리드 MIMO 안테나를 설계하고, 이를 제작하였다. 보조 슬롯은 단말기 후면 메탈 커버에 슬롯을 내어 LTE class 40 대역을 담당하게 하였다. 보조 슬롯은 모노폴 안테나와 함께 하이브리드로 동작한다. 제안 안테나는 LTE class 13/ LTE class 14/ CDMA/ GSM/ DCS/ PCS/ W-CDMA/ LTE class 40 대역에서 VSWR 3:1 이하의 조건을 만족하였다. MIMO 동작을 위한 ECC(Envelope Correlation Coefficient)는 전 대역에서 0.2 이하의 특성을 보였다. MTG 무반사실 측정한 안테나의 평균 이득은 -5.57~-1.45 dBi이고, 효율은 27.75~71.6%로 측정되었다.

• 아태비즈니스연구
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• 제3권1호
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• pp.10-16
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• 2012

India is having a high growth rate of Mobile subscribers which has opened up a new marketing channel of communication with customers. There is a need to study the factors affecting Mobile user's attitude towards Mobile marketing and the relationship between these factors. To study the mobile users attitude towards mobile marketing 489 mobile users opinion is taken on 12 statements for a period of 5 months. Using factor analysis method these 12 statements are grouped into 5 groups they are Mobile advertisement, Mobile Usability, Mobile Promotions, Mobiles shopping and Mobile Marketing. Confirmatory Factor Analysis (CFA) was performed to confirm the findings. SPSS Statistics 17.0 is used to conduct factor analysis and the validity of the model. Once the model was validated, SPSS Amos 18.0 was used to fit a model based on Structure Equation Model to analyze the factors affecting Mobile user's attitude and the relationship between these factors. The present study revealed that Mobile Advertisement and Mobile Sales Promotion are having positive effect on Mobile Marketing where as Mobile Shopping and Mobile Phone Usability is having negative effect on Mobile Marketing. The impact of indicators like Mobile Phone user's permission and personalization of Mobile Phone communication on Mobile Marketing are also discussed in this article.

• 한국전기전자재료학회논문지
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• 제17권9호
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• pp.936-941
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• 2004

In recent years, the rapid growth of portable electronic devices requires the high-energy density characteristics of batteries. Zinc air batteries have specific capacity as high as 820mAh/g. However, Zinc air batteries used for hearing aid applications only so far, because the atmosphere could affect it, and it has weakness in the rate capability. However, recent developments of electrode manufacturing technologies made us to overcome that weakness. And the efforts of applying zinc air batteries to portable electronic devices, especially in cellular phone application have been increased. In this paper, the effects of conducting material and polymer binder in cathode on the electrochemical characteristics were investigated. Our research team succeeded in producing 2.4Ah class zinc air battery for cellular phone application. Its volumetric energy density was 920 wh/l, and gravimetric energy density was 308 wh/kg. The volumetric energy density of our zinc air battery is two times higher than one of lithium secondary battery, and three times higher than that of alkaline manganese battery.

• 한국컴퓨터정보학회논문지
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• 제23권2호
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• pp.117-123
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• 2018

This article is to investigate the possibility that project-based classes introducing mobile phones can replace the monotony of traditional classes led by teachers as well as they can encourage students to take active part in the classes to some extent. The students in groups choose a genre for their own video projects (e.g., movie, drama, news, documentary, and commercial) and produce the video contents using a mobile phone for presentation made at the end of a semester. In the sense that the students are allowed to do video-based mobile phone projects, they can work independently outside of class, where time and space are more flexible and students are free from the anxiety of speaking or acting in front of an audience. A mobile phone project consists of around five stages done both in and outside of the classroom. All of these stages can be graded independently, including genre selection, drafting of scripts, peer review and revision, rehearsals, and presentation of the video. Feedback is given to students. After the presentation, students filled out a survey questionnaire sheet devised to analyze students' responses toward preferences and level of difficulty of the project activity. Finally, proposals are made for introduction of a better mobile phone-based project classes.

• 한국컴퓨터정보학회논문지
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• 제22권6호
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• pp.33-40
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• 2017

This article is to investigate the possibility that project-based classes introducing mobile phones can replace the monotony of traditional classes led by teachers as well as they can encourage students to take active part in the classes to some extent. The students in groups choose a genre for their own video projects (e.g., movie, drama, news, documentary, and commercial) and produce the video contents using a mobile phone for presentation made at the end of a semester. In the sense that the students are allowed to do video-based mobile phone projects, they can work independently outside of class, where time and space are more flexible and students are free from the anxiety of speaking or acting in front of an audience. A mobile phone project consists of around five stages done both in and outside of the classroom. All of these stages can be graded independently, including genre selection, drafting of scripts, peer review and revision, rehearsals, and presentation of the video. Feedback is given to students. After the presentation, students filled out a survey questionnaire sheet devised to analyze students' responses toward preferences and level of difficulty of the project activity. Finally, proposals are made for introduction of a better mobile phone-based project classes.

• 한국컴퓨터정보학회논문지
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• 제25권3호
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• pp.229-234
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• 2020

본 연구에서는 부모의 양육태도와 청소년에 대한 사회적지지 및 휴대전화 의존 간의 구조적 관계에 대한 실증분석을 하는데 연구목적이 있다. 이를 위해 G광역시 소재의 청소년들을 대상으로 설문조사를 하였으며, 수집된 자료는 Amos 18.0을 이용하여 분석하였다. 연구결과를 살펴보면 부모의 양육태도는 청소년에 대한 사회적 지지에 유의한 영향을 미치며, 청소년에 대한 부모의 양육태도와 부모의 사회적 지지는 휴대전화 의존에 유의한 영향을 미치는 것으로 나타났다. 그리고 사회적 지지는 부모의 양육태도와 청소년의 휴대전화 의존 간의 영향관계에 있어서 매개효과가 있는 것으로 나타났다. 따라서 부모의 양육태도와 사회적 지지는 청소년의 휴대전화 의존수준을 낮추어 주는 중요한 변인이라는 시사점을 도출하였다.

• 한국전자파학회논문지
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• 제9권4호
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• pp.491-498
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• 1998

본 논문은 유한차분 시간영역 해석법(Finite-Difference Time-Domain method)을 사용하여 1.8 GHz용 휴대폰으로부터 방출된 전파의 인체 두부에 흡수된 전력량을 산출하였다. 이를 위하여 인체 두부를 7층 매질로 모델령하였고, 휴대폰은 금속상자에 부착된 모노폴 안테나로 모텔링하였다. 모델링에 사용된 인체 두부와 휴대폰의 크기는 상용의 크기를 갖도록 하였다. 이를 위하여 모노폴 안테나의 길이는 4.5 em으로 하였다. 설정된 모텔링하에서 인체의 위해 정도를 알려주는 지수인 비흡수율(SAR-Specific Absorption Rat te)의 분포를 계산하였고 그 결과 비홉수율이 최대가 되는 지점은 인체 두뇌의 깊숙한 점이 아닌 두부의 표피근 방임을 알게 되었다. 그리고 설정된 조건하에서 그 최대치는 1.4 mW/g이었는데, 이는 국제 권고치인 1.6 mW/g보다 약간 작은 값이었다.