• Proceedings of the Korean Information Science Society Conference
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• 2006.10d
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• pp.535-538
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• 2006

현재 많은 PVR SetTop Box가 시중에 나와있는데 그 가격은 만만치가 않다. 또한 요즈음은 PDA와 각 집에 컴퓨터가 널리 보급되어 있다. 이러한 요소들을 종합하여 가장 실용적이고 기능적인 저렴한 가격의 시스템을 구축하는데 그 의미가 있고 이러한 시스템을 제어하는데 큰 의미를 둔다. 본 논문은 저렴한 TV수신카드를 이용한 방송시스템의 구축과 PVR시스템 구현과 OSGi Framework를 이용한 서버 및 제어서버 구현, 그리고 PDA와 Servlet을 이용한 방송청취와 원격지에서 OSGi 서버를 통한 PVR의 제어 및 시청기능을 구현하였다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.12 no.4
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• pp.1594-1617
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• 2018

In this paper, we consider a spectrum access scenario which consists of two groups of users, namely Primary Users (PUs) and Secondary Users (SUs) in Cooperative Cognitive Radio Networks (CCRNs). SUs cooperatively relay PUs messages based on Amplify-and-Forward (AF) and Decode-and-Forward (DF) cooperative techniques, in exchange for accessing some of the spectrum for their secondary communications. From the literatures, we found that the Conventional Distributed Algorithm (CDA) and Pragmatic Distributed Algorithm (PDA) aim to maximize the PU sum-rate resulting in a lower sum-rate for the SU. In this contribution, we have investigated a suit of distributed matching algorithms. More specifically, we investigated SU-based CDA (CDA-SU) and SU-based PDA (PDA-SU) that maximize the SU sum-rate. We have also proposed the All User-based PDA (PDA-ALL), for maximizing the sum-rates of both PU and SU groups. A comparative study of CDA, PDA, CDA-SU, PDA-SU and PDA-ALL is conducted, and the strength of each scheme is highlighted. Different schemes may be suitable for different applications. All schemes are investigated under the idealistic scenario involving perfect coding and perfect modulation, as well as under practical scenario involving actual coding and actual modulation. Explicitly, our practical scenario considers the adaptive coded modulation based DF schemes for transmission flexibility and efficiency. More specifically, we have considered the Self-Concatenated Convolutional Code (SECCC), which exhibits low complexity, since it invokes only a single encoder and a single decoder. Furthermore, puncturing has been employed for enhancing the bandwidth efficiency of SECCC. As another enhancement, physical layer security has been applied to our system by introducing a unique Advanced Encryption Standard (AES) based puncturing to our SECCC scheme.

• Journal of KIISE:Computing Practices and Letters
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• v.8 no.5
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• pp.590-597
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• 2002

Currently, with the increasing demand for combining cellular phone and PDA, various kinds of PDA-phones are being developed. A typical PDA-phone consists of a CDMA processor and a PDA processor. Generally, a UART serial communication port is used for inter-processor communication. However, the CDMA standard will need more data bandwidth over 2Mbps with the emergence of IMT-2000. The bandwidth requirement is beyond the capability of UART. In this paper, several inter-processor communication mechanisms are analyzed and especially Dual Port Memory and USB were chosen as the candidates for the new communication mechanism. A prototype PDA-phone board has been implemented for experiment. The experimental result shows that Dual Port Memory is better than USB in cost performance.

• Journal of the Korean Institute of Intelligent Systems
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• v.15 no.3
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• pp.349-354
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• 2005

In this paper, we propose a mobile telemedicine system that acquires more easily and analyzes individual's bio-signal using PDA. It is not easy for modern people who live busily, disabled patients, or old people to visit hospital. The major goal of this study is to implement the mobile telemedicine systems that the captured bio-signal from remote hospital or other medical treatment device is transmitted via Bluetooth module in ubiquitous environment, PDA with built-in Bluetooth module receives its data and displays on the screen in various form. By implemented systems, it is possible to compare current bio-signal with historical bio-signal and analyze bio-signal, and it is able to make a self diagnosis and it is available to be examined and treated remote diagnosis by sending stored bio-signal to a medical doctor.

• 제어로봇시스템학회:학술대회논문집
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• 2004.08a
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• pp.1833-1837
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• 2004

The two-inertia system, which has the torsion vibration, is typically found in several industrial applications. This torsion vibration will effect the quality of the rolled material as well as the stability of the drive system. Thus the speed and torsion vibration of the system have to be properly controlled. This paper, I-PDA controller designed by Coefficient Diagram Method to control a two-inertia system is proposed. The experimental result shows that both of transient and steady state specification can be fulfilled but the transient response still has long rise time. In order to improve the speed of the system response, a phase lag structure of feedforward controller is introduced to I-PDA control system. It is shown that the performance of the I-PDA control system with suitable FFC has shorter rise and settling times, no overshoot and the torsion vibration can be suppressed.

• The Journal of the Korea Contents Association
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• v.3 no.1
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• pp.47-57
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• 2003

The POS(Point Of Sales) system is S/W and H/W that enables to analyse and evaluate sales information that has been collected in the real-time at point of sales by each department in the store. However, existing POS systems are mainly aiming at the large scaled store with the specific high-priced equipment, so that in applying them to a store specializing in food have weak point to use them in the cost or scale respect. In this paper, we design and implement a web based POS system with PC(Personal Computer) and PDA/(Personal Digital Assistant) in wireless internet environment to apply POS system to a store specializing in food, without specific equipments.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• autumn
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• pp.553-558
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• 2003

The information of works performed by labors can be used for analyzing project status related to schedule, cost and productivity, etc. The purpose of this research is to develop a computer-based system by the application of PDA and barcode technology in order to measue and monitor the amount of workforce resources, works done and productivity. It is anticipated that the effective use of the devepoped system would be able to effectively assist the schedule planning and management for present and prospective construction projects.

• Proceedings of the Korean Information Science Society Conference
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• 2005.11a
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• pp.430-432
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• 2005

PDA는 작은 몸체로 이동성 및 편리성 등이 PC보다 뛰어나지만, 처리 속도가 상대적으로 느리기 때문에 해상도가 큰 이미지, 높은 처리 속도를 요구하는 작업 등을 처리하기에는 효율성이 낮은 문제점이 있다. 또한 정보를 Display할 수 있는 액정이 매우 작아서 환자와 관련된 의료 영상 즉, MRI 사진이나 X-ray 사진 등을 자세히 보기에는 현재의 기술력으로는 매우 어렵다. 그리고 특히 다수의 PDA와 PC 클라이언트의 데이터 요청으로 인한 서버의 과부하 문제 또한 모바일 진료시스템의 발전에 걸림돌이 되고 있다. 따라서 본 논문에서는 처리 속도와 Display의 제한을 대처하기 위하여 모바일 다중처리 시스템과 작업 이양 시스템을 구성하기 위한 하나의 방법론을 제안한다.

• Proceedings of the Korea Information Processing Society Conference
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• 2005.11a
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• pp.431-434
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• 2005

본 논문은 유비쿼터스 컴퓨팅 환경 기반에서의 서명인식 시스템 구현을 기술한다. 구현된 시스템은 PDA와 전자 서명입력기를 이용하여 서명데이터를 획득하고 이 데이터를 유비쿼터스 환경인 무선랜을 이용하여 인증 서버로 전송하여 서버로부터 인증된 결과를 받도록 하였다. 본 시스템의 구성은 터치 스크린을 통한 서명입력이 가능한 PDA와 전자서명입력기를 장착한 무선단말기를 사용하는 클라이언트 부분과 서명을 검증하는 서버 부분으로 나누어 구현 하였다. 본 논문에서 인식알고리즘으로는 서명영상을 구간분할한 후 PCA와 LDA를 사용하여 특징값을 추출한다. 학습과정에서 미리 구한 고유값을 이용하여 서명입력기로부터 획득한 서명데이터를 같은 공간에 투영시켜 서로간의 유사도를 비교하도록 하여 서명인식 속도 및 성능을 개선하였다.

• Proceedings of the Korea Information Processing Society Conference
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• 2002.11b
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• pp.1567-1570
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• 2002

PDA(Personal Digital Assistant)와 같은 Mobile 이동통신기기를 사용한 인터넷 쇼핑은 향후 E-Commerce 시장에서 가장 크게 확산되어질 한 분야로 부상되고 있다. 그러나 현재 인터넷상에 혼재 되어있는 수많은 정보에 대하여 Pocket PC 환경상의 제한된 Screen Size와 느린 통신 속도, 무선 인터넷 접속시의 높은 비용, 저장능력의 한계 등의 문제로 웹 브라우징을 통한 다량의 웹 데이터에 대한 확인과 검색이 어렵고, 사용자가 원하지 않는 정보 또한 산재되어 있어 개인화된 검색 서비스의 요구가 대두되고 있다. 본 연구에서는 PDA 및 Pocket PC를 이용하는 사용자의 관심도를 기준으로 보다 편리하고 효율적인 개인화 Interface의 제공 및 이를 이용한 손쉬운 웹 브라우징 방식을 제시한다. 또한 User 인터랙션 정보를 통해 피드백 함으로써 보다 완벽하게 사용자 개인별 취향에 접근할 수 있는 브라우징 기법을 제시한다.