• Proceedings of the Korea Multimedia Society Conference
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• 2003.05b
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• pp.310-313
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• 2003

PDA를 이용한 무선 네트워크에 대한 활용도가 높아짐에 따라, PDA상에서 이루어지는 무선 네트워크 보안에 대한 관심이 증가하고 있다. PDA 무선 네트워크 보안 문제를 해결하기 위해 많은 연구 및 솔루션 개발이 진행되고 있으나, 이들의 신뢰성을 검증할 만한 시스템 및 연구는 제대로 이루어지지 않고 있다. 본 논문에서는 PDA환경의 무선 네트워크 응용계층 보안모듈들이 무결성 기능을 제대로 제공하는지를 검증 및 관리할 수 있는 시스템을 설계 및 구현하였다.

• Proceedings of the Korea Multimedia Society Conference
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• 2004.05a
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• pp.49-52
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• 2004

M-Commerce에서 안전한 서비스를 제공하기 위해서는 보안 기능을 갖춘 결제 솔루션이 필수적이다. M-Commerce를 이응하기 위한 사용자의 이동 단말기는 핸드폰, PDA, 스마트폰 등으로 다양화 되어가고 있으며, 이 중에서도 PDA의 인터페이스와 이동 접속은 기존 핸드폰의 유선 인터넷의 정보 의존도가 높은 단점을 극복할 수 있다. 본 논문에서는 타원곡선 암호를 이용하여 PDA 기반의 신용카드 결제 시스템을 설계하였다. 제안된 시스템의 SECURE CARD 모듈은 PDA 단말기 자체에 개인정보, 배송정보, 카드정보를 암호화하여 안전하게 저장함으로써 단말기의 정보입력시에 필요한 불편함을 제거하였다. 또한 프로토콜은 M-Commerce에서 인증, 기밀성, 무결성, 부인봉쇄 서비스 둥의 보안기능을 제공하도록 설계되었다.

• Proceedings of the Korean Information Science Society Conference
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• 2001.10a
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• pp.556-558
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• 2001

프로젝트를 수행할 때 고객이 원하는 소프트웨어를 고객이 원하는 시간에 인도하는 것은 중요하다. 개발 기간의 엄수가 중요요소로서 각광을 받는 이유는 개발 기간의 엄수가 프로젝트의 성패를 좌우하기 때문이다. Extreme Programming 은 개발 주기의 단위를 작게 나누어 소프트웨어를 단기간에 개발하기 위한 방법론으로 현재 PDA 개발에 Pair Programming이라는 기법으로 자리잡아가고 있다. 본 논문에서는 PDA 프로그램을 고객인 원하는 품질로 단 기간에 개발하여 프로젝트의 성패에 중요 요소로 자리잡고 있는 개발 기간 엄수를 지킴으로써 PDA 개발 환경에 효과적으로 적용할 수 있는 PDA 프로그래밍을 위한 개발 프로세스를 제시하고자 한다.

• Proceedings of the Korean Information Science Society Conference
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• 2004.10b
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• pp.619-621
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• 2004

유비쿼터스 컴퓨팅에 대한 연구가 활발하게 전개되고 있는 지금, PC에서뿐만 아니라 언제 어디서나 가능한 모바일 환경에서 다양한 사용자 인터랙션에 중점을 두고 떨러 가지 기하객체들과 이미지, 텍스트 객체 등을 지원함으로써 PDA의 고유의 특성을 이용하고 또 이에 알맞은 PDA환경에서 전문적인 저작도구를 개발하는 것이 필요하다. 따라서 PDA와 같은 제한된 스크린 사이즈와 메모리 공간에서 작은 메모리를 사용하여 얼마나 풍부한 컨텐츠가 저작가능한가 하는 것이 아주 중요하다 본 논문은 PDA환경에서 기하객체와 텍스트, 이미지 등 객체들을 이용하여 MPEG-4 컨텐츠 저작함에 있어서 기존의 저작도구의 기초 위에서 PDA환경의 고유 특성을 고려하여 BIFS 텍스트 생성 모듈, BIFS 인코더 모듈. 멀티플렉서 모듈에 대한 최적화 기법을 연구하며 더 나아가서 PDA환경에 보다 적합하면서도 직접적이고도 시각적인 저작이 가능한 MPEG-4 컨텐츠 저작시스템을 제안하고 그 개발 결과를 보인다.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2002.05a
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• pp.105-108
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• 2002

This paper represents the mobile robot control system remote controlled by PDA(personal digital assistance). So far, owing to the development of internet technologies, lots of remote control methods through internet have been proposed. To control a mobile robot through internet and guide it under unknown environment, We propose a control method activated by PDA. In a proposed system, PDA acts as a user interface to communicate with notebook as a controller of the mobile robot system using TCP/IP protocol, and the notebook controls the mobile robot system. The information about the direction and velocity of the mobile robot feedbacks to the PDA and the PDA send new control method produced from the fuzzy inference engine.

• Journal of the Korean Society for Precision Engineering
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• v.11 no.5
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• pp.25-32
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• 1994

A nonlinear control algorithm for the depth control of underwater vehicles is presented. In order to consider the deadzone effect of the flow control valve, a nonlinear fuzzy logic controller (FLC) is synthesized and combined with a linear proportional-derivative-acceleration (PDA) controller, which is called the PDA/FLC controller. And to show the effectiveness of the PDA/FLC control system, it is compared with the linear PDA control system through computer simulation. It is found that the PDA/FLC control system is suitable one to maintain the desirable depth of underwater vehicles with deadzone.

• The Journal of the Korea Contents Association
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• v.12 no.3
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• pp.373-381
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• 2012

Due to IT(information technology) development, various ITs have been applied to tourism. Since June 2010, PDA guide service was launched in Kyungbok palace. This study tried to find how effectively the service is operated by comparing flow, satisfaction and reuse intention of PDA users with those of who have received guide service by professional interpreter. The result indicates that those who have received professional interpretation showed to be more involved, satisfied and have more intention to reuse. The paper explored the composing factors of PDA guide service, which are 'interpretation', 'design', 'ease of use', and 'stability of operation'. Among these factors, interpretation was analyzed to be only factor what affects users' involvement and also most influential attribute explaining users' satisfaction and reuse intention. 'Interpretation', 'stability' and 'ease of use' are shown to have impact on satisfaction, while 'interpretation' and 'stability' have significant effect on users' reuse intention of PDA guide service. The operational implications from these results are suggested.

• Journal of Veterinary Clinics
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• v.26 no.2
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• pp.123-129
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• 2009

Patent ductus arteriosus(PDA) is an abnormal shunt between the descending aorta and pulmonary artery through the incompletely closed ductus arteriosus and is the most common congenital heart defect in dogs. Recent human genetic studies found that a the gene mutation in transcription factor AP-2 beta(TFAP2B) was responsible for syndromic cases of PDA. Mutations in the TFAP2B gene are associated with certain congenital cardiac defects in humans that include PDA. In this study, we isolated the entire coding exons of canine TFAP2B gene for genetic screening in dogs with PDA. Analysis of the deduced amino acid sequence suggested that the canine TFAP2B are phylogenetically closer to the human TFAP2B(100% identity in amino acid sequence) than mouse and rat. In cTFAP2B gene screening, one single c.936+203G>A base change was found in affected Maltese dogs with PDA. However, further screening found the same base change in one unaffected control dog, suggesting this base change might be polymorphism. No other base changes were found in other dog breeds enrolled in this study. Because the base change was located in the intronic region and found in an unaffected control dog, TFAP2B might not be responsible for familial PDA in Malteses and sporadic cases of other dog breeds, although the gene promoter region should be investigated before reaching to this conclusion. A future study that may take this study further would be to collect more samples and to screen TFAP2B in various breeds of dogs with PDA and other various congenital heart defects.

• Journal of Information Processing Systems
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• v.2 no.2
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• pp.76-81
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• 2006

A PDA is used mainly for downloading data from a stationary server such as a desktop PC in an infrastructure network based on wireless LAN. Thus, the overall performance depends heavily on the performance of such downloading with PDA. Unfortunately, for a PDA the time taken to receive data from a PC is longer than the time taken to send it by 53%. Thus, we measured and analyzed all possible factors that could cause the receiving time of a PDA to be delayed with a test bed system. There are crucial factors: the TCP window size, file access time of a PDA, and the inter-packet delay that affects the receiving time of a PDA. The window size of a PDA during the downstream is reduced dramatically to 686 bytes from 32,581 bytes. In addition, because flash memory is embedded into a PDA, writing data into the flash memory takes twice as long as reading the data from it. To alleviate these, we propose three distinct remedies: First, in order to keep the window size at a sender constant, both the size of a socket send buffer for a desktop PC and the size of a socket receive buffer for a PDA should be increased. Second, to shorten its internal file access time, the size of an application buffer implemented in an application should be doubled. Finally, the inter-packet delay of a PDA and a desktop PC at the application layer should be adjusted asymmetrically to lower the traffic bottleneck between these heterogeneous terminals.

• Survey Research
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• v.6 no.1
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• pp.63-81
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• 2005

A survey method in Korea has being developed rapidly since a survey company was established in 1968. In latest, the CATI, internet survey, Notebook, PDA survey methods are being utilized in accordance with communication development. This article focuses on the practical use and the strength and weakness of the PDA survey solution which employs 'KISS' system designed by KRIVET itself. The survey using PDA has, on the one hand, such strengths as follows : 1) efficient field control, 2) reduction of time for verifying data and generation of proper data 3) shortening survey duration from intial survey to data completion, 4) cutting down survey personnel and cost. On the other hand, survey using PDA has the following weakness: 1) limitation of questionnaire expression, 2) increasing time for survey, 3) communication barrier in some regions.