• ETRI Journal
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• 제16권4호
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• pp.1-11
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• 1995

A GaAs power metal semiconductor field effect transistor (MESFET) operating at a voltage as low as 3.3V has been developed with the best performance for digital handheld phone. The device has been fabricated on an epitaxial layer with a low-high doped structure grown by molecular beam epitaxy. The MESFET, fabricated using $0.8{\mu}m$ design rule, showed a maximum drain current density of 330 mA/mm at $V_{gs}$ =0.5V and a gate-to-drain breakdown volt-age of 28 V. The MESFET tested at a 3.3 V drain bias and a 900 MHz operation frequency displayed an output power of 32.5-dBm and a power added efficiency of 68%. The associate power gain at 20 dBm input power and the linear gain were 12.5dB and 16.5dB, respectively. Two tone testing measured at 900.00MHz and 900.03MHz showed that a third-order intercept point is 49.5 dBm. The power MESFET developed in this work is expected to be useful as a power amplifying device for digital hand-held phone because the high linear gain can deliver a high power added efficiency in the linear operation region of output power and the high third-order intercept point can reduce the third-order intermodulation.

• 한국콘텐츠학회:학술대회논문집
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• 한국콘텐츠학회 2006년도 추계 종합학술대회 논문집
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• pp.849-852
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• 2006

본 연구에서는 전자파를 차단 및 흡수하는 물질을 개발하는 추세에 발맞추어 전자파를 흡수할 수 있는 물질을 이용하여 상품화 시키는 것에 초점을 두었다. 예컨대 휴대폰에서 전자파가 많이 발생하게 되는데 전자파를 흡수할 수 있는 물질을 이용하여 만든 캐릭터를 핸드폰 밧테리 부분에 부착 사용하여 전자파를 차단하고자 하는 것이다. 이때 차단하는 부위를 전자파 차단이란 본래 기능외에 캐릭터 개념을 도입하여 악세사리 겸용으로 부착하여 사용할 수 있는 캐릭터를 연구하고자 한다. 캐릭터디자인은 소비자설문조사를 실시하여 선호도가 가장 높은 것을 적용 반영하여 마무리하였다.

• 대한산업공학회지
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• 제37권1호
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• pp.41-54
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• 2011

A central theme in recent IT (information technology) industry is a mobile ecosystem. While a concept of business ecosystem, which is an economic community of firms and individuals producing and consuming goods and services, has been around for about 20 years now, the recent spotlight is mainly caused by the enormous success of iPhone. Many hand-set makers or platform developers want to mimic Apple's iPhone ecosystem from which both application developers and hand-set users can benefit. In this study, a representation model of the business ecosystem is proposed for supporting systematic design and analysis of ecosystems. Whereas previous studies also proposed some representation models, they emphasized only on the value chain between participating players. The proposed model, which is named relation-based ecosystem model, represents an ecosystem with the requirement relationships between product and service components and the roles of players, as well as their value chain. Such comprehensive representation explicitly reveals the strategic difference between ecosystems. This advantage was illustrated by comparing a Korean traditional mobile ecosystem and an emerging smart-phone ecosystem represented by the proposed model.

• 유통과학연구
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• 제12권9호
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• pp.73-82
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• 2014

Purpose - This study aims to illustrate the relationship between demographic factors and perceived risk types, supposing that Korean customers tend to postpone buying or hesitate to purchase the new version of hand sets, because of an early buying risk. Research design, data, and methodology - In addition to existing perceived risk types, the authors introduced an early buying risk. In order to measure each variable, also, the study has employed a five-point Liker-scale. To increase research reliability and validity, the research adopted an exploratory factor analysis, a confirmatory factor analysis, and one-way ANOVA. Results - First, there were statistically significant differences between financial risk and the group. Second, there weren't any statistically significant differences between the group means among the four perceived risk types (Performance Risk, Social Risk, Psychological Risk, and Physical Risk) and 4 factors (Gender, Age, Job, and Education). Lastly, job is apparently differentiated from others (Gender, Age, and Education). Conclusions - The authors found that customers regarded an early buying risk as one of the important perceived risk types, when purchasing a hand set.

• 한국기계가공학회지
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• 제8권2호
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• pp.69-75
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• 2009

This study is analyzed by impact simulation according to material property at terminal case of hand phone. Maximum equivalent stress or strain at plastic is 40 times as great as that at magnesium alloy. And the next greatest stress or strain is shown at aluminium alloy. The value of maximum equivalent stress is shown as 6.5 Mpa in case of plastic, magnesium alloy and aluminium alloy. Maximum shear strain at plastic is 40 times as great as that at magnesium alloy. And the next greatest strain is shown at aluminium alloy. The value of deformation or strain at magnesium alloy and aluminium alloy is not different.

• 한국디자인학회:학술대회논문집
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• 한국디자인학회 2003년도 가을학술발표대회
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• pp.36-37
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• 2003

• 대한산업공학회지
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• 제36권3호
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• pp.146-153
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• 2010

The purposes of this are (1) to present representative five hand dimensions by measurement year, (2) to investigate hand characteristics based on relative ratios of varying hand dimensions and (3) to compare Korean hand dimensions to other countries' data. Comparing to those of 1979, statures of 2004 increased by 3.0~3.5%, while males' hand dimensions of hand length, medius finger length, hand circumference, hand breadth and hand thickness decreased by 2.0~5.0%. Ratios of hand dimensions to those of medius finger were not significantly different depending upon age group and gender, but were significantly different depending upon races of Korean and American. Hand lengths of Koreans were shorter by about 4.0% than those of Japanese irrespective of gender, while the other compared dimensions for Koreans were larger than those of Japanese. Hand dimensions used in this study of Koreans were generally smaller that those of Americans. It is recommended from this study that when designing hand relevant things including glove, computer keyboard, smart phone key pad, etc., the different hand characteristics found in this study be fully reflected to develop competitive products.

• 한국인터넷방송통신학회논문지
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• 제17권5호
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• pp.143-150
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• 2017

본 논문에서는 스마트 폰 추적 및 색상 통신을 이용한 새로운 동작인식 플랫폼을 개발한다. 카메라가 탑재된 PC 혹은 스마트 TV와 개인 스마트 폰 가지고 영상을 기반으로 한 객체 인식 기술을 이용하여 동작 인식 유저 인터페이스를 제공한다. 사용자는 손으로 스마트 폰을 움직여 모션 컨트롤러처럼 사용할 수 있으며, 플랫폼에서는 이 스마트폰을 실시간으로 검출하고, 3차원 거리와 각도를 추정하여 사용자의 동작을 인식한다. 또한, 스마트 폰과 서버의 통신을 위하여 색상 디지털 코드를 이용한 통신 시스템이 사용된다. 사용자들은 색상 통신 방법을 이용하여 텍스트 데이터를 자유자재로 주고받을 수 있으며, 동작을 취하는 도중에도 끊임없이 데이터를 전송할 수 있다. 제안한 동작인식 플랫폼 기반의 실행 가능한 콘텐츠를 구현하여 결과를 제시한다.

• 가족자원경영과 정책
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• 제13권3호
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• pp.281-305
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• 2009

The purpose of this study was to investigate the effect of use motivation type for mobile phones and the degree of loss perception related to mobile phone consumption consciousness in adolescents. The subjects of this study were 503 students in middle and high school in Daegu. A questionnaire was used for the survey. Factor analysis, cluster analysis, and MANOVA were employed for the data analysis and the $Scheff\acute{e}$ test was used for post-hoc analysis. The results are as follows: First, there are significant differences in mobile phone consumption consciousness in all sub-dimension areas according to use motivation type for mobile phone. Second, adolescents with high economic loss perception for mobile phones show high consumption consciousness in sub-dimension area, and adolescents with high academic loss perception show high relation-oriented consumption consciousness. Adolescents with high physical loss perception show high health-oriented, relation-oriented, and function-oriented consumption consciousness. Adolescents with high psychological loss perception, on the other hand, show high relation-oriented consumption consciousness. Third, there are significant differences in mobile phone consumption consciousness according to use motivation type for mobile phones and the degree of overall loss perception. However, there are no significant differences in the mobile phone consumption consciousness according to use motivation type for mobile phones and the degree of overall loss perception.

• 대한기계학회논문집A
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• 제25권4호
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• pp.695-702
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• 2001

In this paper, the drop/impact simulation for a mobile phone has been carried out with the explicit code LS-DYNA and its validation has been experimentally verified. The small size of this kind of electronics products makes it time-consuming, and difficult to conduct drop tests to detect the failure mechanism and identify their drop behaviors. Strict drop/impact performance criteria of such hand held electronic products as mobile phones play an important role in their design because these products must withstand both normal and unexpected shock. Usually, the product durability on drop impact depends on designers experience. The present reliable methodology of drop/impact simulation provides an efficient and powerful vehicle to improve the design quality and reduce the design period.