• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2003년도 하계종합학술대회 논문집 Ⅲ
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• pp.1661-1664
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• 2003

The transcoding is a method which converts a multimedia stream to an adaptive format, such as frame rate and resolution, that can be played in the mobile devices. Due to the heavy consumption of CPU power for transcoding, the server in charge cannot supply all streams requested from clients if it is already occupied by several streams. The load balancing among proxies is a common approach for solving such problem. In addition to collaborative works for load balancing, the mobility must be taken into account in the mobile environments. Thus, the wired-network based algorithm is not suitable for the streams service in the mobile environments. In this paper, we propose an alternative scheme for cooperative proxy architecture that considers the case in which mobile devices are moving over other zones.

• 디지털융복합연구
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• 제9권1호
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• pp.115-124
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• 2011

The property of the mobile phone is taking important role to choose it. In the present situation, exploring, comparing and analyzing the important properties of regular mobile phone(feature phone) and smart phone are very meaningful study. Therefore, the survey was carried out to get the properties of feature phone and smart phone and analyze the difference of those phones. And proposed the important variables for customer satisfaction which must be given priority. The result showed that 'design' and 'Quality' are important to both mobile phone user groups. The problems with mobile phones currently in use were 'poor performance' to feature phone users and 'expensive charge' and 'poor A/S' to smart phone users. Two groups also showed significant difference with the customer satisfactions, and smart phone user group showed higher satisfaction. For smart phone user group, four factors are induced from the properties but 'Hardware Quality' (representing 'call Quality', 'A/S', 'Convenience to use', 'Battery life') and 'Design & Function'(representing 'Internet', 'Convergence Functions', 'Design, 'Color') have significant and positive effects on Customer Satisfaction.

• 한국의류학회지
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• 제33권7호
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• pp.1164-1179
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• 2009

This study presented the characteristics of a mobile fashion shopping mall as perceived by those in charge of fashion brands, clarified the effect of the characteristics on the intention 'Of introduction, and indicated the differences in the intention of introduction according to the characteristics of brands. This study surveyed individuals in charge of fashion & clothing brands. It utilized SPSS 12.0 program for data analysis and performed frequency analysis, validity analysis, reliability analysis, multi regression analysis, ANOVA, and hierarchical adjustment regression analysis. A summary of the results of this study are as follows: First, the results of the factor analysis are shown to clarify the characteristics of mobile fashion shopping mall; four factors such as facility/usefulness, instant accessibility, personalization, and playfulness were also represented. Second, it showed that facility/usefulness, instant accessibility and personalization generate a positive influence on the intention of introduction. Of the factors, facility/usefulness displayed the highest influence. Third, regarding the effect of the characteristics of a mobile fashion shopping mall on the intention of introduction according to the characteristics of brands (in the case of women's wear) the intention of introduction is strong as instant accessibility and facility/usefulness is highly recognized. Lastly, there is a difference in the intention of introduction according to the characteristics of brands. According to items, casual wear shows the highest intention of introduction as followed by women's wear and sportswear. According to age, brands targeting a 24-29 year old group show a higher intention. Companies with average sales of 50 billion won to 750 billion won (or more) for three years showed a high intention. In addition, the possibility of introduction as a new distribution line was investigated.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2007년도 제38회 하계학술대회
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• pp.1984-1985
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• 2007

Polyimide is widely used as a high-temperature insulating material. Space charge distributions in polyimide (PI) films strongly depend upon electric field, temperature, water content and so on. We observed space charge distributions in PI films with various water contents. When a dc field was applied to as-received PI films or water-treated PI films, positive and negative homo space charges were observed near the respective electrodes at 333 K. In dried PI films, the homo space charges were much reduced, and positive and negative hetero space charges in the bulk were clearly observed. The space charge amounts in water-treated PI films were smaller than in as-received ones, while the current density in water-treated PI film was larger than that in as-received one by two or more orders of magnitude. These suggest not only that the charge injection from the electrode is enhanced by absorbed water but also that absorbed water makes carriers mobile. The decay of space charge was also faster in water-treated PI than in as-received or dried one. This also supports the enhancement of apparent mobilities of carriers in PI by absorbed water.

• 대한임베디드공학회논문지
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• 제7권2호
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• pp.95-101
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• 2012

In order to supply emotion service depending on user's emotional change in a mobile environment, various researches have been carried. This paper discusses a protocol for wireless charging and an embedded platform of the mobile emotional sensing device which supports that. Wireless charging process relieves user's vexatious task to charge the emotional sensing device. To support wireless charging, there are one basestation and several mobile devices. Basestation coordinates and controls the devices over wireless communication, as well as supplies energy. For 1:N communication we defines the network whose superframe is classified into four categories: a network join superframe, a charging request superframe, a charging superframe and an inactive superframe. Physical layer provides how to supply energy to the devices and communicate physically. Mobile device is equipped with energy charged circuits, which correspond with the defined energy supplying method, as well as bidirectional communication circuits. Mobile device monitors and analyzes its own battery status, and is able to send a request packet to basestation. Therefore, it can be charged before its battery is exhausted without user's perception.

• 경영과학
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• 제24권2호
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• pp.127-142
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• 2007

This study deals with the optimal design of mobile access network connecting base stations(BSs) and mobile switching centers(MSCs). Generally mobile operators constitute their access networks by leasing communication lines. Using the characteristic of leased line rate based on administration region, we build an optimization model for mobile access network design which has much smaller number of variables than the existing researches. And we develop a GUI based optimization tool integrating the well-known softwares such as MS EXCEL. MS VisualBasic, MS PowerPoint and Ip_solve, a freeware optimization software. Employing the current access network configuration of a Korean mobile carrier, this study using the optimization tool obtain an optimal solution for both single MSC access network and nation-wide access network. Each optimal access network achieves 7.45% and 9.49% save of lease rate, respectively. Considering the monthly charge and total amount of lease line rate, our optimization tool provides big amount of save in network operation cost. Besides the graphical representation of access networks makes the operator easily understand and compare current and optimal access networks.

• 한국정보통신학회논문지
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• 제19권4호
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• pp.933-939
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• 2015

일반전원이 공급되지 않은 광파표지는 태양광을 이용한 전력공급시스템을 사용하고 있다. 이러한 전력공급시스템에서는 충 방전조절기의 역할이 매우 중요하다. 항로표지의 효과적인 관리를 위해 도입된 IT기술(AIS통신 등)은 광파표지에 전력을 사용하는 장치를 추가하게 됨으로써 충 방전조절기의 중요성이 증가하고 있다. 현재 운용되는 충 방전조절기는 항로표지 내부에 부착되어 해상환경에 따라 점검 및 확인하는데 어려움이 있다. 이를 해결하기 위해서 본 논문에서는 충 방전조절기에 블루투스 모듈을 구성하여 근거리 점검이 가능한 모니터링 시스템을 제안하였다. 제안한 시스템은 도입 비용이 적고, 구성이 간편하여 다양한 항로표지에 응용가능한 장점이 있다. 또한 근거리에서 충 방전조절기의 실시간 상태정보를 확인할 수 있어서 점검 비용을 절감하고, 점검 시 발생 가능한 위험요소를 줄일 수 있다.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2002년도 추계종합학술대회
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• pp.102-105
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• 2002

본 고에서는 이동망 착신접속료 규제 필요성과 다양한 착신 접속료 산정 대안을 살펴보고 소매시장 경쟁측면, 접속시장 효율성 측면, 접속제공자 수지보전 측면, 그리고 접속원가 배분측면 등의 회계적인 측면에서 가장 합리적인 이동망 착신접속료 산정방안을 살펴보고자 한다.

• 한국공간정보시스템학회 논문지
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• 제4권2호
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• pp.35-40
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• 2002

본 연구에서는 현재 개발되고 있는 차량측량시스템(또는 Mobile Mapping System)에서 사용하기 위한 CCD(Charge Coupled Device) 카메라 영상을 취득하는 프로그램을 개발하였다. 특히 2개의 고해상도 칼라영상을 동시에 취득하여 저장할 수 있도록 하여 수치사진측량 기법의 적용이 가능하도록 하였다. 본 연구에서 개발한 프로그램은 GPS-IMU의 장비와 결합하여 차량측량시스템을 이용한 각종 시설물의 3차원 위치 결정, 보존상태 파악 등에 보다 효율적으로 이유될 수 있을 것이다. 특히 현재까지 개발되어 활용중인 프로그램들이 흑백영상을 대상으로 하고 있는 반면 본 연구에서 사용하고 있는 영상은 고해상도의 칼라영상이기 때문에 대상물의 판독력을 높일 수 있어 차량측량시스템의 활용분야를 넓일 수 있을 것으로 기대된다.

• 한국멀티미디어학회논문지
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• 제6권2호
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• pp.267-275
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• 2003

무선 이동 통신은 발전을 거듭하면서 그 활용 범위가 음성 위주에서 인터넷을 지원하는 데이터 중심의 서비스로 확대되고 있다 이에 따라 무선 단말기로 보다 효율적으로 인터넷에 접근하기 위한 데이터 전송방법 연구가 활발히 이루어지고 있다. 무선 이동 통신은 휴대가 간편하고 이동이 쉬워 사용자가 급증하고 있다 이와 함께 유선통신을 기반으로 하는 인터넷상의 정보들도 무선 인터넷 통신용으로 빠르게 바뀌어가고 있다 네트워크 확장에 따른 무선 데이터 용량의 급속한 증가와 무선 인터넷으로 언제 어느 곳에서나 인터넷을 이용할 수 있는 환경이 무선 컨텐츠의 증가를 요구하고 있는 것이다 이러한 요구를 수용하기 위해서는 다양한 단말 특성에 따라 컨텐츠를 재 작성해야 한다. 하지만 무선 컨텐츠를 새로 개발하는데 개발비용이 많이 투입된 다. 본 논문에서는 이러한 문제점을 해결하기 위해서 유선 인터넷상에 있는 Web문서 형태의 컨텐츠를 XML Parser를 통하여 변환, 가공하여 새로운 모바일 컨텐츠를 설계하는 방법을 소개한다. 이 시스템을 이용해 서비스를 제공 할 수 있는 모바일 컨텐츠 개발의 생산성을 향상시키고 개발기간과 비용을 단축해 신속한 무선 인터넷을 제공 하는데 그 목적이 있다.