• 제목/요약/키워드: wireless technology

검색결과 4,886건 처리시간 0.032초

Wireless Channel Identification Algorithm Based on Feature Extraction and BP Neural Network

  • Li, Dengao;Wu, Gang;Zhao, Jumin;Niu, Wenhui;Liu, Qi
    • Journal of Information Processing Systems
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    • 제13권1호
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    • pp.141-151
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    • 2017
  • Effective identification of wireless channel in different scenarios or regions can solve the problems of multipath interference in process of wireless communication. In this paper, different characteristics of wireless channel are extracted based on the arrival time and received signal strength, such as the number of multipath, time delay and delay spread, to establish the feature vector set of wireless channel which is used to train backpropagation (BP) neural network to identify different wireless channels. Experimental results show that the proposed algorithm can accurately identify different wireless channels, and the accuracy can reach 97.59%.

VERIFICATION OF ELECTROMAGNETIC EFFECTS FROM WIRELESS DEVICES IN OPERATING NUCLEAR POWER PLANTS

  • YE, SONG-HAE;KIM, YOUNG-SIK;LYOU, HO-SUN;KIM, MIN-SUK;LYOU, JOON
    • Nuclear Engineering and Technology
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    • 제47권6호
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    • pp.729-737
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    • 2015
  • Wireless communication technologies, especially smartphones, have become increasingly common. Wireless technology is widely used in general industry and this trend is also expected to grow with the development of wireless technology. However, wireless technology is not currently applied in any domestic operating nuclear power plants (NPPs) because of the highest priority of the safety policy. Wireless technology is required in operating NPPs, however, in order to improve the emergency responses and work efficiency of the operators and maintenance personnel during its operation. The wired telephone network in domestic NPPs can be simply connected to a wireless local area network to use wireless devices. This design change can improve the ability of the operators and personnel to respond to an emergency situation by using important equipment for a safe shutdown. IEEE 802.11 smartphones (Wi-Fi standard), Internet Protocol (IP) phones, personal digital assistant (PDA) for field work, notebooks used with web cameras, and remote site monitoring tablet PCs for on-site testing may be considered as wireless devices that can be used in domestic operating NPPs. Despite its advantages, wireless technology has only been used during the overhaul period in Korean NPPs due to the electromagnetic influence of sensitive equipment and cyber security problems. This paper presents the electromagnetic verification results from major sensitive equipment after using wireless devices in domestic operating NPPs. It also provides a solution for electromagnetic interference/radio frequency interference (EMI/RFI) from portable and fixed wireless devices with a Wi-Fi communication environment within domestic NPPs.

Fly-By-Wireless 비행제어 기술의 연구 동향 (A Survey on Fly-By-Wireless Flight Control Technology)

  • 한정수;하철수;오수헌;강승은;고상호
    • 한국항공운항학회지
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    • 제22권1호
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    • pp.7-14
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    • 2014
  • This paper deals with recent research cases and directions of Fly-By-Wireless (FBWLS) flight control technology. FBWLS is a new type of flight control system technology with the aim of solving the problems mainly caused by the increasing amount of wires in aircraft to which Fly-By-Wire (FBW) technology applies. Therefore, in FBWLS flight control system the wired communication system is replaced with a wireless communication system. Currently the FBWLS flight control technology is at an initial development stage and thus this paper surveys deals with the cases in the viewpoint of technology feasibility. In this context, this paper analyzes technology that needs further studies to secure the reliability, stability and accuracy to the similar level of the corresponding FBW system. Since the major problems of FBWLS technology are packet losses and time delays so that this paper suggests the research direction of wireless communication protocol selection, optimization of wireless communication network and controller design considered communication environment.

Koinonia 기반 무선 DVR 시스템의 구현 (Implementations of Wireless DVR System on Koinonia Technology)

  • 김용성;조진웅;홍대기
    • 반도체디스플레이기술학회지
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    • 제12권1호
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    • pp.9-14
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    • 2013
  • In this paper, we first introduce a Koinonia technology. Then we present a wireless Digital Video Recorder (DVR) system based on the Koinonia technology. In addition we implement the wireless DVR system, which is composed of Wireless DVR-Slave (WDVR-S), Wireless DVR-Access Point (WDVR-AP), and Wireless DVR-Emergence Management System (WDVR-EMS). Also we present the acquired Korea Communication Commission (KCC) mark for the last products. The developed system will give a hint that the Koinonia technology can be adopted in wireless DVR systems to handle safety and security issues.

특허분석을 통한 무선충전 기술방향 분석 (Research on the Development Direction of Wireless Charging Technology Using Patent Analysis)

  • 양동원;이행병
    • 한국IT서비스학회지
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    • 제19권3호
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    • pp.89-100
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    • 2020
  • The wireless power transmission market is growing at an average annual rate of 51.5% from $ 16.4 billion in 2015 to $ 131.1 billion in 2020. However, there are limitations to commercialization due to the development of standards and technologies. Thus, this study identified trends in standards and regulations by market and by country. The research collected and filtered a total of 69,488 worldwide wireless power transfer patents by June 2019 and extracted a total of 28,555 patents. Based on this, technology development status was analyzed and predicted. In this study, long-distance and short-range technology development with high technology development difficulty and low technology development ratio could lead to growth of the entire wireless charging market. It is analyzed that investment and policy preparation are necessary to secure source technology for long-distance / near technology development than China, Japan and Europe.

Binary CDMA 기술을 이용한 무선 원격검침 시스템 구현 (Implementation of Wireless AMR System using Binary CDMA)

  • 권대길;조진웅;홍대기
    • 반도체디스플레이기술학회지
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    • 제12권4호
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    • pp.1-7
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    • 2013
  • This paper presents the AMR (Automatic Meter Reading) system using the binary CDMA (Code Division Multiple Access) radio technology. The binary CDMA is the new radio technology in domestic research. Main implementation topics includes the binary CDMA remote meter reading system, the wireless piconet configuration for the wireless automatic meter reading, and the transmission scheduling for sending and receiving data. Also, the wireless packet data encryption is very important topics for the wireless automatic meter reading. The proposed AMR system is implemented as a pilot project in Jeju and Gangwon. It can be seen that the wireless remote reading using the binary CDMA wireless technology can be applied to the AMR system.

개인 무선네트워크에서 CSS 방식과 RSSI 를 이용한 거리측정에 관한 연구 (A Study on Distance Measurement using CSS and RSSI in WPAN)

  • 권대길;조진웅;임승옥;이장연;이현석;원윤재
    • 대한전자공학회:학술대회논문집
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    • 대한전자공학회 2008년도 하계종합학술대회
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    • pp.321-322
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    • 2008
  • CSS(Chirp Spread Spectrum) technology adopt SDS-TWR algorithms of TOA(Time of Arrival) using velocity of specific medium and ToF(Time of Flight) to measure a distance, but this method always has a regular error on distance regardless of a real distance, as a result, in far distance, it decrease a error on distance relatively, but in near distance, it increase a error on distance relatively. in this paper, we propose and test new method measuring a distance more precisely in near distance using CSS and RSSI

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