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검색결과 778건 처리시간 0.026초

iPOJO-based Middleware Solutions for Self-Reconfiguration and Self-Optimization

  • Bellavista, Paolo;Corradi, Antonio;Fontana, Damiano;Monti, Stefano
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • 제5권8호
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    • pp.1368-1387
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    • 2011
  • In recent years, ubiquitous and pervasive scenarios have emerged as a complex ecosystem where differentiated software/hardware components interoperate wirelessly and seamlessly. The goal is to enable users to continuously access services and contents, and to always get the best out of their current environment and available resources. In such dynamic and flexible scenarios, the need emerges for flexible and general solutions for continuous runtime self-reconfiguration and self-optimization of ubiquitous support software systems. This paper proposes a fully reconfigurable middleware approach that aims at reconfiguring complex software systems made up of heterogeneous off-the-shelf components from both functional and non-functional perspectives. Our middleware can also extend already existing and non-reconfigurable middleware/applications in an easy and flexible way, with no need to re-design them. The proposed design principles have been practically applied to the implementation of a runtime self-reconfigurable middleware called Off-The-Shelf Ready To Go (OTS-RTG), implemented on top of iPOJO. The reported experimental results both exhibit a limited overhead and show the wide applicability of the proposed solution to many application scenarios, including complex, industrial, Enterprise Service Bus-based ones.

하이드로폰 송신 어레이를 이용한 수중 음향 통신 시스템의 성능 향상 (Performance Enhancement of Underwater Acoustic Communication System Using Hydrophone Transmit Array)

  • 이외형;손윤준;김기만
    • 한국음향학회지
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    • 제21권7호
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    • pp.606-613
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    • 2002
  • 본 논문에서는 수중에서 송신 빔 형성기를 이용한 고속 데이터 전송 기법을 연구하였다. 또한 범용 디지털 신호처리 프로세서와 다수의 디지탈-아날로그 변환기를 이용한 시험용 송신단을 설계 및 구현하였으며, 구현된 시스템을 이용하여 수조에서 실험을 수행하여 그 성능을 분석하였다. 이때 실험 과정을 단순화하기 위하여 채널 코딩 및 등화기 (equalizer) 등과 같은 과정은 생략하였고, 간장 간단한 디지털 통신 변조 기법인 OOK(On-Off keying) 기법을 사용하였다. 실험 결과 5개의 하이드로폰 송신 어레이를 사용한 경우에 1개만 사용했을 때보다 오차율 10/sup -2/을 기준으로 전송 속도가 약 3배 향상되었으며, 실험에 사용된 수조에서 음성 신호 전송을 위해 400 bps 정도까지 가능함을 확인하였다.

The Optical Characteristics of the Soft X-Ray Telescope Aboard Yohkoh : The On- and Off-Axis Point Spread Function

  • 신준호
    • 천문학회보
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    • 제38권1호
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    • pp.64.1-64.1
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    • 2013
  • The point spread function (PSF) of an optical system is in general defined as a two-dimensional intensity distribution which results from a single point source at infinity. It is an important key for the evaluation of the optical performance of an astronomical telescope. The PSFs of the soft X-ray telescope (SXT) aboard Yohkoh were measured in a wide range of the field-of-view under the in-flight configuration at White Sands Missile Range prior to launching the satellite. It has been known that the SXT PSF has a sharp peak at the core and the intensity drops very fast as it goes distant from the center. Due to the combination of this sharp peak at the PSF core and the effect of undersampling by a large pixel size, a carefully designed method is requested in the examination of the PSF data. The pattern of the SXT PSF is determined by the fitting of a mathematical functional form to the pre-launch experimental data. The elliptical Moffat function has been adopted for the evaluation of the SXT PSF. It is revealed from our study that the SXT PSF shows a peculiar characteristics, and thus a careful consideration on the undersampling effect and also a proper choice of statistics are necessary for the determination of the best fit function of the PSF. Details on the on- and off-axis SXT PSF in the field-of-view will be introduced and discussed in our presentation.

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MPEG-4 비디오 전송을 위한 결합 소스/채널 부호화에 관한 연구 (A Study on Joint Source/Channel Coding for MPEG-4 Video Transmission)

  • 이운문;손원;이수인
    • 방송공학회논문지
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    • 제8권2호
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    • pp.163-171
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    • 2003
  • 고정 및 이동수신환경에서 결합 소스/채널 부호화 기법을 MPEG-4(Moving picture Experts Group) 비디오 전송에 적용하여 대역폭 사용 효율을 높이는 방안에 대하여 논하였다. 채널환경은 랜덤잡음환경과 이동수신환경을 고려하였다. 소스부호화기는 MPEG-4 비디오, 채널부호화기는 RCPC(Rate Compatible Punctured Convolution) 그리고 변조방식은 QPSK(Quadrature Phase Shift Keying)를 적용하였다. 이 논문에서는 여러가지 채널상태(Es/No)에 따른 율-왜곡특성에 대해 분석하여 소스비트율과 채널부호율 간에 최적의 상충점(Trade-off point)을 결정하였고, 결합 소스/채널 부호화 기법과 일반적인 고정부호율 전송기법을 비교하여 결합 소스/채널부호화의 효율성을 보였다.

획의 방향 코드 조합에 의한 오프라인 필기체 숫자 인식 (Off-line Handwritten Digit Recognition by Combining Direction Codes of Strokes)

  • 이찬희;정순호
    • 한국정보과학회논문지:소프트웨어및응용
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    • 제31권12호
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    • pp.1581-1590
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    • 2004
  • 본 논문은 한 가지 특징 요소로서 획 방향 코드들만을 사용하는 강건한 오프라인 필기체 숫자 인식 방법을 제안한다. 이 방법은 입력된 숫자 이미지에 대하여 일반적인 8방향 코드를 생성하고 이 코드들의 조합을 다층 신경망에 학습하고 각 숫자를 인식하게 한다. 8방향 코드들은 다양하게 표현된 숫자들의 자기구성 그래프(SOG*:Improved Self-Organizing Graph) 세선화 결과에 의해 만들어지고 이 코드의 사용은 2개 이상의 특징점들을 처리하는 기존의 복합적인 단계들을 단순화시킨다. 실험결과는 모든 숫자 데이타베이스의 어떤 이미지들에 대해서도 인식률이 일관성 있게 98.85% 이상임을 보여준다.

직류링크전류를 기반으로 한 SRM 3상전류 추정법 (3-Phase Current Estimation of SRM Based on DC-Link Current)

  • 김주진;최재호;김태웅
    • 전력전자학회논문지
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    • 제11권4호
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    • pp.307-312
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    • 2006
  • 본 논문에서는 직류링크전류를 기반으로 SRM의 상전류를 추정하였고 이를 이용한 SRM 에 대한 속도제어법을 제안하였다. 또한 직류링크전류검출회로를 제안하여 전류검출분해능을 높일 수 있었으며 오프셋에 의한 영향을 최소화시킬 수 있는 장점을 가지고 있다. 상전류 정보를 이용한 SRM 구동방식과 직류링크전류정보를 이용한 SRM 구동방식을 실제실험을 통하여 비교함으로서 본 논문에서 제안한 상전류 추정알고리즘과 이에 관련된 직류링크전류 검출회로에 대한 유효성이 검증되었고 직류링크전류를 이용한 SRM 속도제어시스템은 속도응답이 3 상 전류정보를 이용한 시스템만큼 빠른 응답특성이 있음을 확인하였다.

A Flow Analysis of Small Craft by Using CFD

  • Park, Ji-Yong;Jeong, Jin-Hee;Hwang, Tea-Wook;Lee, Sol-Ah;Kim, Kyung-Sung
    • Journal of Multimedia Information System
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    • 제7권4호
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    • pp.269-276
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    • 2020
  • The small craft including jet-board for leisure are commonly smaller than the general commercial vessels. For the floating vessel, the motion analysis is significantly important component to design the shape. It is, however, hardly predicting its behavior by using conventional boundary element method due to violating small amplitude assumption for potential theory. The computational fluid dynamics method can afford to simulate such small craft, but its grid system was not able to calculate motion, because movable body disturbs the grid system by confliction. The dynamics fluid body interaction model with over-set mesh system can be dealt with movable floating body under irregular ocean wave. In this study, several cases were considered to reveal that DFBI is essential method to predict floating body motion. The single phase simulate was conducted to establish the shape perfection, and then the validated vessel was simulated with ocean waves weather DFBI option on or off. Through the comparison, the results between the cases of DFBI on and off shows significantly difference. It was claimed that the DFBI was necessary not only to calculation body motion, but also to predict accurate drag and lift force on the floating body for small size craft.

Korean Brain Tumor Society Consensus Review for the Practical Recommendations on Glioma Management in Korea

  • Chul-Kee Park;Jong Hee Chang
    • Journal of Korean Neurosurgical Society
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    • 제66권3호
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    • pp.308-315
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    • 2023
  • Recent updates in genomic-integrated glioma classification have caused confusion in current clinical practice, as management protocols and health insurance systems are based on evidence from previous diagnostic classifications. The Korean Brain Tumor Society conducted an electronic questionnaire for society members, asking for their ideas on risk group categorization and preferred treatment for each individual diagnosis listed in the new World Health Organization (WHO) classification of gliomas. Additionally, the current off-label drug use (OLDU) protocols for glioma management approved by the Health Insurance Review and Assessment Service (HIRA) in Korea were investigated. A total of 24 responses were collected from 20 major institutes in Korea. A consensus was reached on the dichotomic definition of risk groups for glioma prognosis, using age, performance status, and extent of resection. In selecting management protocols, there was general consistency in decisions according to the WHO grade and the risk group, regardless of the individual diagnosis. As of December 2022, there were 22 OLDU protocols available for the management of gliomas in Korea. The consensus and available options described in this report will be temporarily helpful until there is an accumulation of evidence for effective management under the new classification system for gliomas.

무게 감지와 경보시스템을 갖춘 스마트 캐리어 개발 (Development of Smart Carrier with Weight Sensing and Alarm System)

  • 조준수;김승겸;서동섭;곽세영;김재욱
    • 한국전자통신학회논문지
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    • 제17권2호
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    • pp.317-324
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    • 2022
  • 본 논문에서는 일반 캐리어의 기능을 고려하여 캐리어의 단점 및 이용할 때의 불편한 점의 내용을 토대로 보완 및 개선을 위해 다양한 편리성 기능을 가진 스마트 캐리어를 연구하였다. 스마트폰 앱을 통해 캐리어에 LED와 모터잠금장치를 설치하고 on/off로 간단하게 제어하는 블루투스 인식 및 제어기능, 로드셀 센서를 캐리어 내부에 설치하여 물품을 넣었을 때 무게를 감지하여 LCD panel에 측정된 값을 보여주는 무게감지 기능, 블루투스와 경보기를 캐리어에 설치하고, 비콘과 거리를 설정하여 설정 거리 값을 벗어나면 경보시스템이 발생하여 도난 및 분실을 방지하는 기능을 갖춘 스마트 캐리어를 제작 및 실험하였다.

공동주택 거주자의 에너지 사용행태 및 에너지 절약의식 분석 (Analysis on the Characteristics of Energy Use Behaviors and Energy Saving Consciousness of Multi-family Housing Residents)

  • 이윤재;이현수;박소윤
    • 한국주거학회논문집
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    • 제22권6호
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    • pp.31-42
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    • 2011
  • The purpose of the study was to investigate the characteristics of energy use behaviors and energy saving consciousness of multi-family housing residents. The energy referred to in this study includes electric energy, heating energy and water usage. This study was conducted from a survey carried out in Seoul and Gyeonggi-do. The results of the study are as follows: First, among the survey questions, the only positive energy saving behaviors shown by the occupants was turning off the lights and the television, and in the use of kitchen appliances; it could therefore be concluded that, in general, energy saving attitude and consciousness were not sufficient to reduce energy consumption. Second, the results showed high mean scores for the behaviors which were easy to control, such as turning off lights and televisions, and low mean scores for the behaviors which required extra effort to completely cut off electricity energy such as pulling out the plugs of electronic appliances. Third, it was found that the occupants generally showed the tendency to save heating energy. However, in cases where the occupants were required to continuously and directly experience indoor temperatures, they expressed passive attitudes toward saving energy. Fourth, they showed wasteful attitudes toward water usage by leaving the tap running when taking showers and washing their faces. Fifth, while they showed a strong energy saving consciousness, they also showed a passive attitude about putting this into practice; there was therefore some gap between attitude and behavior. Lastly, among the socio-demographic factors, age and family lifecycle were very important factors affecting energy use and energy saving consciousness.