• The Journal of Society for e-Business Studies
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• v.8 no.3
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• pp.165-176
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• 2003

Instead of existing cell phones, PDAs are observed as leading wireless Internet devices recently Numerous applications are developed by extended usage of PDAs and it should be installed appropriately according to devices. Furthermore, when battery is discharged, all data stored in RAM(Random Access Memory) becomes obsolete. So it should be recovered or reinstalled from flash memory, backup media or something. In this paper, we present an automatic application installation system(PAIS : PDA Automatic Installation System) to solve problems that users have to install applications by themselves whenever it is necessary. With this system, users feel comfortable by saving time and effort to install each applications and application development companies save cost needed to make materials illustrating installation process. Consequently PAIS may flourish wireless Internet business.

• Journal of Korea Multimedia Society
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• v.7 no.12
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• pp.1719-1728
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• 2004

The fusion of Internet technology and applications with wireless communication provides a new business model and promises to extend the possibilities of commerce to what is popularly called mobile commerce, or m-commerce. In mobile Internet banking service through wireless local area network, security is a most important factor to consider. We describe the development of security service for mobile Internet banking on Personal Digital Assistants (PDAs). Banking Server and Authentication Server were developed to simulate banking business and to support certificate management of authorized clients, respectively. To increase security, we took hybrid approach in implementation: symmetric block encryption and public-key encryption. Hash function and random number generation were exploited to generate a secret key. The data regarding banking service were encrypted with symmetric block encryption, RC4, and the random number sequence was done with public-key encryption. PDAs communicate through IEEE 802.IIb wireless LAN (Local Area Network) to access banking service. Several banking services and graphic user interfaces, which emulatedthe services of real bank, were developed to verity the working of each security service in PDA, the Banking Server, and the Authentication Server.

• Korean Management Science Review
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• v.23 no.1
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• pp.21-41
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• 2006

Given the growing deployment of mobile offices, we need to understand the fectors which affect their successful use and implementation. We in this paper present a parsimonious model which integrates the IS success model and the TAM. The main feature of the model is that it allows one to explore the role of mobility of mobile office systems in determining the level of system usage and dependence. Although the mobility is the key property of any mobile system, there is little research effort exerted to understand how mobility affects the traditional IS factors such as perceived ease of use and usefulness. In addition to the system usage, this model also uses dependence as the dependent variable. This is expected to provide richer understanding of the study context. We collected survey data from 1,614 field service workers of a major domestic electronic company. They use PDAs to retrieve information regarding the specifics of the customer service requests and to report what has been done for each service job. The results from SEM analysis show that mobility improves the perceived ease of use which then leads the field service workers to depend more on the PDA systems. Interestingly enough, however, the workers' satisfaction does not cause more frequent use of the system.

• Journal of Environmental Science International
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• v.13 no.10
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• pp.891-902
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• 2004

In order to predict air pollution and Yellow-sand dispersion precisely, it is necessary to clarify the sensitivity of meteorological field input interval. Therefore numerical experiment by atmospheric dynamic model(RAMS) and atmospheric dispersion model(PDAS) was performed for evaluating the effect of temporal and spatial resolution of meteorological data on particle dispersion. The results are as follows: 1) Base on the result of RAMS simulation, surface wind direction and speed can either synchronize upper wind or not. If surface wind and upper wind do not synchronize, precise prediction of Yellow-sand dispersion is strongly associated with upwelling process of sand of particle. 2) There is no significant discrepance in distribution of particle under usage of difference temporal resolution of meteorological information at early time of simulation, but the difference of distribution of particles become large as time goes by. 3) There is little difference between calculated particles distributions in dispersion experiments with high temporal resolution of meteorological data. On the other hand, low resolution of meteorological data occur the quantitative difference of particle density and there is strong tendency to the quantitative difference.

• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.519-520
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• 2007

본 논문은 무인화 변전소 확대와 디지털보호계전기의 지속적인 적용에 따라 상시 보호계전기 상태 확인 및 필요시 정정치 변경과 전력계통 고장시 동작한 보호계전기의 동작사항을 신속히 파악하여 보호계전기 정동작 여부를 판단하여 전력계통의 신뢰도 제고하는 보호계전기 데이터 원격 취득 분석시스템 구축 방안을 연구하였다. PDAS 설치후 고장데이터 수집에 따른 출동시간을 절약하여 고장분석업무를 집중하고 절감시간을 타 업무에 활용할 수 있었으며 고장인지 후 즉시 보호계전기 데이터를 취득 분석하여 고장현상 파악 및 긴급복구 시간을 단축할 수 있는 효과를 거둘 수 있었다. PDAS 시스템 시범운영결과 발생한 문제점을 분석한 결과 고도화된 고장분석 서비스를 구축하기 위해서는 정전고장관리시스템과의 연계, 보안성 강화, 사용자 편의성향상, 신규서비스 지원이 되도록 하여 송변전 통합정보시스템과의 통합이 필요하다.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.16 no.2
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• pp.3-12
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• 2006

The spread of mobile devices, PDAs and sensors has enabled the construction of ubiquitous computing environments, transforming regular physical spaces into 'smart space' augmented with intelligence and enhanced with services. However, unless privacy concerns are taken into account early in the design process of various ubiquitous devices(e.g. mobile devices, PDAs, sensors, etc.). we will end up crating ubiquitous surveillance infrastructure. Also, it may inappropriate to use public key techniques for computational constrained devices in ubiquitous computing environment. In this paper, we propose efficient user authentication and ky agreement protocol not only to preserve anonymity for protecting personal privacy but also to be suitable for computational constrained devices in ubiquitous computing environments.

• Journal of Aerospace System Engineering
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• v.4 no.2
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• pp.32-37
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• 2010

Use of wireless portable devices, like mobile phones, PDAs and Laptops is explosively increasing. Used in the aircraft, these PEDs can introduce EMI problem to aircraft Com/Nav systems. This paper addresses some foreign research result on interference caused by PEDs which are used onboard and policy of Japan and USA to limit use of PED on board.

• Proceedings of the Korean Information Science Society Conference
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• 2002.04a
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• pp.457-459
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• 2002

본 논문에서는 고정된 공간에서 유선 인터넷망에 접속하던 환경에서 벗어나 휴대성과 이동성의 특징을 갖는 개인 휴대 단말기(PDA)에 무선 랜 카드를 장착하여 이동 중에도 무선 인터넷에 접속하여 실시간으로 영상을 전송 받아 원하는 장소를 감시 할 수 있는 시스템을 구축하여 공간적 한계를 극복하는데 초점을 맞추고 있다.

• Proceedings of the Korean Information Science Society Conference
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• 2001.10c
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• pp.193-195
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• 2001

본 논문에서는 데스크탑 환경에서의 공동작업 시스템을 Windows CE환경에 적합하게 고안한 MoCoS 시스템에 대해 설명한다. Windows CE를 기반으로 하는 이동단말기의 경우, 사용할 수 있는 리소스가 데스크탑에 비해 상당히 제한적인 점등의 특성을 가지고 있다. MoCoS 시스템은 세션관리와 공동작업 어플리케이션을 클라이언트-서버구조로 분리하여 처리함으로써 이러한 제 한 사항을 해결하였다. 또한 클라이언트 모듈은 Java언어로 작성함으로써 향후 다양한 플랫폼 및 05를 사용하는 단말기로의 확장도 용이하도록 하였다.

• Proceedings of the Korean Institute of Communication Sciences Conference
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• 2004.07a
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• pp.265-265
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• 2004