• Journal of the Korea Institute of Information and Communication Engineering
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• v.7 no.6
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• pp.1103-1108
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• 2003

In this paper, the characteristics of an inverted-F antenna for the 2.4GHz local wireless communication system have been analysed in terms of the variation of design parameters. The antenna can be integrated on printed circuit board, and the characteristics in terms of the variation of the gap between feed line and shorting stub, gap between antenna's leg and ground plane, antenna leg's width, substrate's height and dielectric constant are analysed. By using these characterization plot of design parameter, the tuning techniques are proposed to design optimum antenna. The designed antenna has 6.4 % frequency bandwidth for VSWR under 1.5 and 3dB gain.

• Proceedings of the Korean Information Science Society Conference
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• 2002.10d
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• pp.148-150
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• 2002

본 논문은 모바일 핸드셋이라는 제한적인 디스플레이 환경과 입력환경에서 필요한 라우트맵의 시각화에 따른 문제점과 그 해결방안을 제시한 논문이다. 자동차 네비게이션 시스템에서 널리 사용되는 경로표시 방법은 일반적으로 노트북이나, PDA, 전용 디스플레이 시스템등에서 구현되어 있으나, 모바일 핸드셋과 같이 제한된 디스플레이 환경에서의 경로표시 방법은 현재까지 많은 연구가 이루어지지 않고 있다. 본 논문은 인간의 인식능력이 임의의 경로를 회전방향점(turning point)의 연속으로 인식한다는 점에 착안하여 원래의 경로가 가진 축적을 변형하여 선분과 회전방향점으로 경로를 표시하는 라인 드라이브 시스템을 모바일 환경의 경로표시 방법으로 사용하였다. 본 논문에서 구현한 시스템은 GIS의 벡터 정보를 가지고 있는 서버와 Brew 플랫폼을 지원하는 모바일 핸드셋으로 구성된다. GIS 서버는 프로토타입 정보를 추출하여 모바일 핸드셋으로 전송하고, 이러한 정보는 모바일 핸드셋의 Brew 플랫폼에서 간략화, 도식화 과정을 거쳐서 시각화된다. 본 논문은 제한된 디스플레이 환경의 경로 확대표시를 위하여 계층별 경로 시각화 방법을 사용하여 가독성을 높이고 사용상의 편리함을 추구한다.

• Journal of the Korean Society of Marine Environment & Safety
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• v.10 no.1 s.20
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• pp.9-14
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• 2004

Many lighthouses have been built for safety navigation of vessel, but the management of lighthouses had to paid for maintenance costs. For that reason, the remote control system for the lighthouse is to be used, but the communication expense is very expensive because of the use of satellite communication network or the RF communication network Also, the state of lighthouse is difficult to analyze as transmit only measured data. Therefore, this paper embodied the remote control system for the lighthouse using CDMA method, that was extended to island area and we verified the effectiveness of the proposed system.

• Journal of Biomedical Engineering Research
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• v.30 no.3
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• pp.185-190
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• 2009

Biomedical mobile devices for ubiquitous healthcare consist of biomedical sensors and communication terminal. They have two types of configuration. One is the sensor-network type device using wired or wireless communication with intelligent sensors to acquire biomedical data. The other is the sensor embedded type device, where the data can be acquired directly by itself. There are many examples of sensor network type, such as, fall detection sensor, blood glucose sensor, and ECG sensors networked with commercial PDA phone and commercial phone terminal for ubiquitous healthcare. On the other hand, sensor embedded type mounts blood glucose sensor, accelerometer, and etc. on commercial phone. However, to enable true ubiquitous healthcare, motion sensing is essential, because users go around anywhere and their signals should be measured and monitored, when they are affected by the motion. Therefore, in this paper, two biomedical mobile devices with motion monitoring function were addressed. One is sensor-network type with motion monitoring function, which uses Zigbee communication to measure the ECG, PPG and acceleration. The other is sensor-embedded type with motion monitoring function, which also can measure the data and uses the built-in cellular phone network modem for remote connection. These devices are expected to be useful for ubiquitous healthcare in coming aged society in Korea.

• Journal of Korea Society of Industrial Information Systems
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• v.14 no.5
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• pp.169-185
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• 2009

This study set out to analyze the impacts of convergence products(cell phones, PDAs, IPTV, and portable game consoles) on the consumers' purchase intention and satisfaction. These results of the research model show that usefulness, perceived risk, and communication had significant influences on purchase intention, and usefulness, innovation, perceived risk, and communication on satisfaction. But there were differences according to the product kinds. The results indicate that usefulness, convenience, perceived risk, and communication are the major factors affecting the satisfaction and purchase intention of convergence products and that innovation didn't have much influence on them. And there were small differences among the influential factors according to the kinds of convergence products.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.11 no.2
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• pp.89-94
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• 2011

Today, the utilization of communication devices is being increased including information terminals, cell phones, handheld personal digital assistants (PDA) caused by the development of information and communication technology. The development of information and services is speeding up, whereas most communication devices have provided a inefficient hierarchical menu and sequential searching structure. In this study, the Adaptive User Interface is applied to the Bus Information Terminal(BIT) which is one of communication equipment installed in the bus stop. It will be based on analysis of unspecified individuals' preferences and user's directly personalization in the BIT prototype. We expect the results of this study to be possible to provide users with efficient and convenient information acquisition and contribute to the development of public transport use by improving the accessibility and usability of BIT.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.20 no.1
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• pp.63-72
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• 2010

RFID is one of useful identification technology in ubiquitous environments which can be a replacement of bar code. RFID is basically consisted of tag, reader, which is for perception of the tag, and back-end-database for saving the information of tags. Although the usage of mobile readers in cellular phone or PDA increases, related studies are not enough to be secure for practical environments. There are many factors for using mobile leaders, instead of static leaders. In mobile reader environments, before constructing the secure protocol, we must consider these problems: 1) easy to lose the mobile reader 2) hard to keep the connection with back-end-database because of communication obstacle, the limitation of communication range, and so on. To find the solution against those problems, Han et al. suggest RFID mutual authentication protocol without back-end-database environment. However Han et al.'s protocol is able to be traced tag location by using eavesdropping, spoofing, and replay attack. Passive tag based on low cost is required lots of communication unsuitably. Hence, we analyze some vulnerabilities of Han et al.'s protocol and suggest RFID mutual authentication protocol without online back-end-database in aspect of efficiency and security.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.12 no.2
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• pp.243-249
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• 2012

These days it is becoming more and more common to find electronic medical screening systems installed in Oriental hospitals and clinics. This is a relatively new development for the practice of traditional Oriental medicine. Specifically, Pulse detection machines are being utilized in order to help determine a patient's disease scientifically. However, identifying and diagnosing the specific disease correctly for each patient is still very difficult in Oriental medicine. The intention of this paper is to propose a solution which uses two separate Electronic systems working together to produce a better likelihood of finding the correct diagnosis for each patient. It is proposed that an EMR intelligent electronic chart system be developed and employed, which would utilize both Pulse wave system and a tongue detection system at the same time, in order to solve the problem. Computer simulation results have proven to show that EMR systems used in hospitals and clinics are more efficient and yield a more accurate diagnosis than traditional methods.

• 한국HCI학회:학술대회논문집
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• 2009.02a
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• pp.846-850
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• 2009

본 논문은 픽토그램(Pictogram)의 시각전달 요소를 재해석하고 증강현실 환경에서의 효율적 전달 방법에 대하여 제안한다. 픽토그램은 국경을 넘어 남녀노소 모두가 인지할 수 있어야 함이 규칙이며 불특정 다수라는 사용자들을 위해 정확한 정보를 담고 있는 시각전달 매체로서 공정성, 객관성을 가지고 디자인 되어야 한다. 사용자에게 정보전달 인식을 높이기 위해 표준 픽토그램 과 문화 속에서 발견할 수 있는 행위들을 접목하여 애니메이션으로 제작하고, 이를 다양한 연구분야에서 응용되고 있는 증강현실 (Augmented Reality 또는 AR) 기술에 적용하여 표현하였다. 증강현실은 사용자-콘텐츠 정보전달 매체로서 현실 환경을 기반으로 하는 3 차원공간의 시각정보에 대한 사용자의 인식을 향상시킬 수 있는 방법으로 인간-컴퓨터 상호작용(Human-Computer Interaction)을 제공한다. 본 논문에서 제시된 픽토메이션은 기존 공공장소 어디서나 만날 수 있는 다양한 픽토그램을 패턴화하여 마커로 활용하고 사용자는 현재 널리 보급되고 있는 UMPC 혹은 PDA를 통하여 증강현실 환경에서 제작된 픽토메이션 콘텐츠를 경험해 볼 수 있다. 픽토메이션은 시각커뮤니케이션의 효과를 증가 시킬 수 있고, 정보습득의 주체인 사용자에게 콘텐츠의 종류를 예측할 수 있는 선택의 자유를 준다. 본 논문에서는 멀티미디어디자인 요소를 포함한 콘텐츠와의 실시간 상호작용을 통하여 유희적 요소의 접목을 시도하고 증강현실환경에서 Pictomation을 통하여 사용자들과의 효과적 커뮤니케이션을 위한 방법을 모색하고자 한다.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2003.05a
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• pp.100-103
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• 2003

In this paper, the characteristics of an inverted-F antenna for the 2.4GHz local wireless communication system have been analysed in terms of the variation of design parameters. The antenna can be integrated on printed circuit board, and the characteristics in terms of the variation of the gap between feed line and shorting stub, gap between antenna's leg and ground plane, antenna leg's width, substrate's height and dielectric constant are analysed. By using these characterization plot of design parameter, the tuning techniques are proposed to design optimum antenna. The designed antenna has 6.4% frequency bandwidth for VSWR under 1.5 and 3dB gain.