• KSII Transactions on Internet and Information Systems (TIIS)
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• 제12권4호
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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.

• 한국정보과학회:학술대회논문집
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• 한국정보과학회 2005년도 가을 학술발표논문집 Vol.32 No.2 (1)
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• pp.583-585
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• 2005

WebDAV 프로토콜은 웹상의 공동 저작활동을 지원하기 위한 IETF 표준으로써, 원거리에 있는 사용자들 간에 파일을 공동 편집하고 관리할 수 있도록 해주는 HTTP 프로토콜의 확장이다. 이것은 웹상에서 가상의 작업공간을 구성함으로써, 원격 사용자들 간에 새로운 방식으로 공동작업을 가능하게 한다. 무선 네트워크 기술과 무선 장치의 발달로 이동을 하면서 WebDAV 서버에 접속한 후 협업을 수행한다면 유선 환경보다 효율적인 협업을 할 수 있을 것이다. 본 논문에서는 .NET Compact Framework 환경에서 동작하는 PDA WebDAV 클라이언트를 설계하였다. 본 클라이언트는 무선 네트워크를 지원하는 환경에서 PDA를 이용하여 WebDAV 서버와 HTTP 요청을 통하여 서버 자원을 확인할 수 있다. 이러한 PDA WebDAV 클라이언트는 PDA 환경에 맞는 인터페이스를 가져야 하고, 또한 WebDAV 명세를 따라야 한다. PDA WebDAV 클라이언트는 공간의 제약을 받지 않는 PDA를 이용함으로써 자료의 효율적인 공유 및 교환을 통하여 능동적인 협업 환경을 구축 할 수 있다.

• 제어로봇시스템학회논문지
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• 제12궈1호
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• pp.23-27
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• 2006

As a pervasive healthcare application to help medication of elderly patients, the smart compliance monitors have been recently proposed. In this paper, we present a new smart drug/medicine pack (SDP) for ubiquitous medication monitoring, for which the packaging is either paper packet or blister pack. This ubiquitous compliance monitor is composed of several SDPs and a Bluetooth equipped PDA phone. The SDP is a wireless module that monitors the medication consumption unobtrusively by transmitting the sensed data of 'drug removal' events to the medical center and by reminding patients when they take a dose on their mobile phone. The communication between SDP modules and PDA is realized via Bluetooth. The PDA is basically embedded to indicate the medication record and to alert every prescribed medication time during treatment. Experimental results show that the proposed system works exactly when the SDPs are far within about 2 [m] from PDA.

• 대한인간공학회지
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• 제22권4호
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• pp.27-45
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• 2003

PDAs(Personal Digital Assistants), one of the typical mobile devices, are examined in this study to identify the factors affecting their usability. This study focuses on the menu design of PDAs. Three factors including menu extension method, menu structure, and screen orientation were manipulated in a usability experiment. Task completion times, error rates, and degree of subjective satisfaction were measured. Guidelines for designing a PDA menu are proposed based on the experimental results.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2004년도 학술대회 논문집 정보 및 제어부문
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• pp.206-208
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• 2004

A new method to control a remote robot with PDA and wireless network is presented. The needs of remote control systems using a home network environments are increased in these days. To solve the shortage of IP address in network, authorized TCP/IP and unauthorized TCP/IP address are used. The unauthorized TCP/IP is obtained by using MAC Address in the system and Network Layer. The model in the system is similar to Sever&Client in structure. Using this system, it is very easy to combine one network device with other network system. A robot system and PDA are used to show the effectiveness of the control system in home network environments.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2005년도 춘계학술대회논문집
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• pp.945-948
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• 2005

Mobile computing devices are becoming increasingly prevalent in a huge range of physical area, offering a considerable market opportunity. The focus of this paper is on the development of a platform of fault diagnosis system integrating with personal digital assistant (PDA). An improvement of induction machine rotor fault diagnosis based on AI algorithms approach is presented. This network system consists of two parts; condition monitoring and fault diagnosis by using Artificial Intelligence algorithm. LabVIEW allows easy interaction between acquisition instrumentation and operators. Also it can easily integrate AI algorithm. This paper presents a development environment fur intelligent application for PDA. The introduced configuration is a LabVIEW application in PDA module toolkit which is LabVIEW software.

• 센서학회지
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• 제13권6호
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• pp.454-461
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• 2004

We have designed a portable electronic nose (e-nose) system using an array of commercial gas sensors and personal digital assistants (PDA) for the recognition and analysis of volatile organic compounds (VOC) in the field. Field screening of pollutants has been a target of instrumental development during the past years. A portable e-nose system was advantageous to localize the special extent of a pollution or to find pollutants source. The employment of PDA improved the user-interface and data transfer by Internet from on-site to remote computer. We adapted the Lavenberg-Marquardt algorithm based on the back-propagation and proposed the method that could predict the concentration levels of VOC gases after classification by separating neural network into two parts.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2006년도 춘계종합학술대회
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• pp.792-795
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• 2006

본 논문에서는 주정차 단속을 위해 PDA를 이용하여 자동차 번호판을 인식하는 방법을 제시한다. 현재까지 도입되어 사용 중인 세 종류의 자동차 번호판의 특징을 이용하여 번호판의 종류를 구분하고, 지역명, 지역코드, 용도문자 및 일련번호를 영역화하여 자동차번호판을 인식하였다. PDA를 이용해 영상을 획득하여 번호판 인식 시스템 실험 결과 88.7%의 인식률을 보였다.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2008년도 추계학술대회B
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• pp.2692-2695
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• 2008

Polydiacetylene (PDA) is chemosensor materials that exhibit non-fluorescent-to-fluorescent transition as well as blue-to-red visible color change upon chemical or thermal stress. They have been studied in forms of film or microarray chip, so far. In this paper, we provide a novel technique to fabricate continuous micro-fiber PDA sensor using in-situ laser-polymerization technique and 3-D hydrodynamic focusing on a microfluidic chip. The flow of a monomer solution with diacetylene (DA) monomer is focused by a sheath flow on a 3-D microfluidic chip. The focused flow is exposed to 365 nm UV laser beam for in-situ polymerization which generates a continuous fiber containing DA monomers. Then, the fiber is exposed to 254 nm UV light to polymerize DA monomers to PDA. Preliminary results indicate that the fiber size can be controlled by the flow rates of the monomer solution and sheath flows and that a PDA sensor fiber successively responds to chemical and thermal stress.

• Clinical and Experimental Pediatrics
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• 제46권11호
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• pp.1080-1084
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• 2003

목 적 : 저자들은 RDS 환아의 임상 경과 중에서 PDA가 동반되는 군과 동반되지 않은 군을 비교하여, 이들의 주산기 병력의 특성, 임상 양상과 경과를 비교 관찰하여 두 군 사이에 차이점이 있는지를 검토함으로서, 향후 RDS 환아의 관리에서 PDA 동반에 따른 효율적인 관리의 정보를 얻기 위하여 본 연구를 실시하였다. 방 법 : 2000년 1월부터 2002년 12월까지 경희대학교병원 신생아 집중치료실에서 신생아 RDS로 진단되어 치료한 총 83례를 대상으로 하였다. 총 83례 중에서 PDA를 동반한 군(A군)은 17례, PDA를 동반하지 않은 군(B군)은 66례였다. PDA는 울혈성 심부전의 임상증상을 보이거나, 청진상 심잡음이 들리며, 방사선 소견상에서 폐부종이 심해지거나 CT ratio가 증가되는 경우에 심초음파를 하여 진단하였다. 후향적 방법으로 증례들의 임상 기록지를 검토하여, 두 군 사이의 임상적 양상과 경과의 차이점을 분석하였다. 결 과: A군에서 B군에 비해 재태기간이 짧고 출생 체중이 낮아 미숙의 정도가 심할수록 PDA의 발생 빈도가 높았다. 주산기 가사의 빈도는 A군에서 의미있게 높았다. 만성 폐질환, 뇌실 내출혈, 괴사성 장염, 미숙아 망막증, 구루병, 패혈증, 담즙성 황달의 빈도가 B군에 비하여 A군에서 높았다. 결 론 : 두 군의 주산기 병력의 특성은 유의한 차이를 보임을 알 수 있었고 만성 폐질환 등의 합병증의 발생이 유의한 차이를 보였으나 후자의 경우 재태기간을 포함한 여러 인자를 고려하여야 하므로 앞으로 더 많은 연구가 이루어져야 한다고 사료된다.