• Title/Summary/Keyword: Short distance communication system

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Height Estimation of pedestrian based on image (영상기반 보행자 키 추정 방법)

  • Kim, Sung-Min;Song, Jong-Kwan;Yoon, Byung-Woo;Park, Jang-Sik
    • The Journal of the Korea institute of electronic communication sciences
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    • v.9 no.9
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    • pp.1035-1042
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    • 2014
  • Object recognition is one of the key technologies of the monitoring system for the prevention of various intelligent crimes. The height is one of the physical information of a person, and it may be important information for identification of the person. In this paper, a method which can detect pedestrians from CCTV images and estimate the height of the detected objects, is proposed. In this method, GMM (Gaussian Mixture Model) method was used to separate the moving object from the background and the pedestrian was detected using the conditions such as the width-height ratio and the size of the candidate objects. The proposed method was applied to the CCTV video, and the height of the pedestrian at far-distance, middle- distance, near-distance was estimated for the same person, and the accuracy was evaluated. Experimental results showed that the proposed method can estimate the height of the pedestrian as the accuracy of 97% for the short-range, 98% for the medium-range, and more than 97% for the far-range. The image sizes for the same pedestrian are different as the position of him in the image, it is shown that the proposed algorithm can estimate the height of pedestrian for various position effectively.

Design of 24GHz Patch Array Antenna for Detecting Obstacles (장애물 감지용 24GHz 대역 패치 배열 안테나 설계)

  • Lee, Kwang;Kim, Young-Su
    • The Journal of the Korea institute of electronic communication sciences
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    • v.16 no.6
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    • pp.1075-1080
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    • 2021
  • In this paper, we designed a 24.4GHz 2-channel TX and 4-channel RX patch array antenna mounted on a short-range vehicle radar system to simultaneously measure the range and speed of a single object within a single measurement cycle. The antenna was designed and fabricated using Rogers' RO4350B(εr=3.48, 0.5T) board. Through measurement, it was confirmed that the design specifications of antenna gain (> 10dBi or more) and radiation pattern (Elevation HPBW > 10deg.) were satisfied at 24.4 GHz frequency.

OFDM System for Wireless-PAN related short distance Maritime Data Communication (Wireless PAN기반의 근거리 해상통신용 OFDM 송수신회로에 관한 연구)

  • Cho, Seung-Il;Cha, Jae-Sang;Park, Gye-Kack;Yang, Chung-Mo;Kim, Seong-Kweon
    • Journal of the Korean Institute of Intelligent Systems
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    • v.19 no.1
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    • pp.145-151
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    • 2009
  • Orthogonal Frequency Division Multiplexing (OFDM) has been focused on as 4th generation communication method for realization of Ubiquitous Network in land mobile communications services, and has been a standard technology of Wireless Local Area Network (WLAN) for a High Date Rate communication. And in maritime data communication using high frequency (HF) band, 32-point FFT OFDM system is recommended by International Telecommunication Union (ITU). Maritime communication should be kept on connecting when maritime accident or the maritime disaster happen. Therefore, main device FFT should be operated with low power consumption. In this paper we propose a low power 32-point FFT algorithm using radix-2 and radix-4 for low power operation. The proposed algorithm was designed using VHSIC hardware description language (VHDL), and it was confirmed that the output value of Spartan-3 field-programmable gate array (FPGA) board corresponded to the output value calculated using Matlab. The proposed 32-point FFT algorithm will be useful as a leading technology in a HF maritime data communication.

A Study on Information Sharing Methods for Casualties in Maritime Emergency Scenes (해양응급현장에서의 사상자 정보 공유 방안에 관한 연구)

  • Seungyong Kim;Incheol Hwang;Dongsik Kim;Jungjae Shin
    • Journal of the Society of Disaster Information
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    • v.20 no.1
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    • pp.206-212
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    • 2024
  • Purpose: This study conducted research on the sharing of information to enhance the survival rate of emergency patients by swiftly transferring them to appropriate hospitals through sharing the patients' conditions, treatment histories, and transportation information with the Maritime Police Agency and relevant agencies when emergencies occur in the marine environment. Methods: In this study, emergency patient information classified in a smartphone app was received, stored, and transmitted using the LoRa communication method by electronic triage tags, and the transmitted emergency patient information was implemented to be collected in real-time through a hybrid triage system along with LoRa receivers. Results: Through the hybrid triage system, it was possible to receive emergency patient information according to the distance or confirm delayed reception. It was observed that most data were received when the distance was short, while data reception was unsuccessful in relatively longer distances. Conclusion: It was confirmed that in mass disaster environments where internet communication is impossible, rapid and accurate understanding of casualty information at disaster sites and appropriate disaster responses can be achieved using self-networking methods such as LoRa communication. However, limitations inherent in communication methods were also recognized. Further research on various communication methods is required to collect emergency patient information and transfer them to appropriate hospitals in situations where internet communication is unavailable.

A study on the datalink Interface between fighter jet RADAR and BVR AA guided missile (전투기 레이다의 시계 외 중거리 공대공 유도탄 데이터링크 연동방안 연구)

  • Yong-min Kim
    • Journal of Advanced Navigation Technology
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    • v.27 no.4
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    • pp.453-456
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    • 2023
  • Fighter jets employ guided missiles equipped with seekers to counter enemy air threats. Short range guided missiles(SRM) usually carry infrared(IR) seekers and are used to engage targets within visual range. On the other hand, medium range guided missiles(MRM) often utilize radio frequency(RF) seekers to engage targets beyond visual range. Medium range guided missiles do not activate their seekers until they reach the detection range of the seeker, and the aircraft's radar guides them for a certain distance. This guidance method is called Missile Data Link(MDL), and it can be implemented in either one-way or two-way communication modes, depending on the missile's communication system. In this paper, we discuss MDL based on these two communication modes, along with the integration of RADAR, mission computers, and guided missiles.

Distributed Antenna System for Intra-vehicle Wireless Energy Transfer (차량 내 무선 에너지 전송을 위한 분산 안테나 시스템)

  • Kim, Yeonghwan;Kwon, Kuhyung;Lee, Chungyong
    • Journal of the Institute of Electronics and Information Engineers
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    • v.54 no.2
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    • pp.3-8
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    • 2017
  • This paper considers an application of distributed antenna system (DAS) to a system of intra-vehicle wireless energy transfer (WET). The intra-vehicle WET system has features such as limited mobility of energy receiver, static channel environment and short distance between transmitter and human body. Under these conditions, location of transmitter highly affects the amount of energy received by human body and the energy received by energy receiving devices. We compare centralized antenna system (CAS) and the DAS in intra-vehicle WET system by simulation. The results show the DAS has superior performance to the CAS.

Implementation of Multipurpose PCI Express Adapter Cards with On-Board Optical Module

  • Koo, Kyungmo;Yu, Junglok;Kim, Sangwan;Choi, Min;Cha, Kwangho
    • Journal of Information Processing Systems
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    • v.14 no.1
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    • pp.270-279
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    • 2018
  • PCI Express (PCIe) bus, which was only used as an internal I/O bus of a computer system, has expanded its function to outside of a system, with progress of PCIe switching processor. In particular, advanced features of PCIe switching processor enable PCIe bus to serve as an interconnection network as well as connecting external devices. As PCIe switching processors more advanced, it is required to consider the different adapter card architecture. This study developed multipurpose adapter cards by applying an on-board optical module, a latest optical communications element, in order to improve transfer distance and utilization. The performance evaluation confirmed that the new adapter cards with long cable can provide the same bandwidth as that of the existing adapter cards with short copper cable.

A Study on the Development of Next Generation Wireless PAN Algorithms with Location Awareness Technique (위치인식기반의 차세대 무선 PAN 알고리즘 개발에 관한 연구)

  • Cho, Juphil
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.16 no.10
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    • pp.2095-2100
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    • 2012
  • In this paper, we propose the channel sounding scheme which is made for ideal communication between some application as well as the short distance of high speed data transmission in MIMO-OFDM system for Wireless PAN. This method is able to perceive the duration of the impulse response through the delaying of power delay profile, modeled a power delay profile which has an attenuate characteristic, and obtained the coefficient of channel response by ML (maximum likelihood). Through the amplitudes, phases and delays associated with each multipath component which were acquired from this channel sounding scheme, we can describe the wave propagation characteristics of channels between the transmitter and receiver so that the receiver could enhance not only the reliability but also the ability of communication link. Multi agent system models can be used to analyze the path of the system within any time frame. Further, parameter values can be perturbed to examine how the path of the system changes in response to exogenous shocks.

A Dosimeter System using a short distance radio communication (근거리 무선 통신을 이용한 선량계 구현)

  • Seo, Yong-Chil;Son, Jong-Dae;Lee, Heung-Ho;Kim, Seung-Ho
    • Proceedings of the KIEE Conference
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    • 2004.11c
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    • pp.571-573
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    • 2004
  • 본 논문에서는 휴대용 선량계 시스템에 거리 무선 통신 방식중 Bluetooth를 이용하여 선량계를 구현한 것에 대해 논하였다. 휴대용 선량계란 감마선과 속중성자 및 열중성자를 현장에서 실시간으로 측정 할 수 있는 기기이다. 휴대용 선량계는 선랑계의 소형화를 위해 모듈별로 구성하여 공간의 최적화를 취하였다. 모듈의 구성은 시스템의 전반적인 제어를 하는 CPU부 센서로부터 측정한 데이터를 처리하는 신호처리부 방사선량을 측정하는 센서부로 구성되어졌다. 센서 모들의 PIN 다이오드와 MODFET 센서를 이용하여 감마선, 속중성자, 열중성자를 측정한다. 휴대용 선량계를 관리하고 측정한 데이터의 백업 및 분석을 위하여 PC용 관리프로그램과 근거리 무선 통신(Bluetooth)을 사용하여 통신하도록 만들어 사용하였다. 측정 지역의 방사선량을 휴대용 선량계로 측정하여 PC용 관리프로그램에서 실시간으로 방사선량을 확인 할 수 있다.

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A Low-Power Low-Complexity Transmitter for FM-UWB Systems

  • Zhou, Bo;Wang, Jingchao
    • JSTS:Journal of Semiconductor Technology and Science
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    • v.15 no.2
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    • pp.194-201
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    • 2015
  • A frequency modulated ultra-wideband (FM-UWB) transmitter with a high-robust relaxation oscillator for subcarrier generation and a dual-path Ring VCO for RF FM is proposed, featuring low power and low complexity. A prototype 3.65-4.25 GHz FM-UWB transceiver employing the presented transmitter is fabricated in $0.18{\mu}m$ CMOS for short-range wireless data transmission. Experimental results show a bit error rate (BER) of $10^{-6}$ at a data rate of 12.5 kb/s with a communication distance of 60 cm is achieved and the power dissipation of 4.3 mW for the proposed transmitter is observed from a 1.8 V supply.