• Title/Summary/Keyword: wireless data communication

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Real-time Water Supply Facilities Monitoring System based on the USN (USN 기반의 실시간 수도설비 모니터링 시스템)

  • Kim, Yong-Tae;Yoo, Neung-Hwan;Park, Gil-Cheol;Kim, Seok-Soo;Kim, Tai-Hoon;Lee, Sang-Ho
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.11 no.6
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    • pp.1207-1213
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    • 2007
  • This paper has researched water supply facilities management using real-time water utility monitoring system based on USN(Ubiquitous Sensor Network) which is consisted of wireless sensors transferring waterworks facilities md treatment information about a valve-room and flowmeter-room of water supply installation. In the manholes, it was installed with flowmeter, pressure sensors, vibration sensors, Co-sensors, and hydro-thermograph sensors. These measurement values which are received by PDA are used for facilities operation on the spot safely and conveniently. It has also provided safe installation management via CDMA(Code Division Multiple Access) network which transfers data to remote servers to monitoring at a distance place. With safety management system of water supply facilities on USN technology convenience and safety is increased in real situation, and it is expected that we can supply clean water to people as much safer and more effective water supply installation management.

An Enhanced Routing Protocol for Supporting Node Mobility in Multi-hop Ad-hoc Networks (다중 홉 Ad-hoc 네트워크에서 노드이동성을 고려한 라우팅 프로토콜에 관한 연구)

  • Kim, Kwan-Woong;Kim, Byun-Gon;Kim, Yong-Kab
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.11 no.9
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    • pp.1665-1671
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    • 2007
  • Mobile Ad hoc Networks (MANETs) refer to autonomous networks in which wireless data communications are established between multiple nodes in a given coverage area without a base station or centralized administration. Because of node mobility and limited battery life, the network topology may changes frequently. Selecting the most reliable path during route discovery process is important to improve performance in ad-hoc networks. In this study, we proposed an enhanced routing protocol based on AODV by monitoring variation of receiving signal strength. New metric function that consists of node mobility and hops of path is used for routing decision. From extensive experiments by using NS-2, The performance of the proposed routing scheme has been imp개ved by comparison to AODV protocol.

Development of On-board Computer Module for Formation Flying and Cluster Operation Nano-satellites (초소형 위성의 편대 및 군집 운용을 위한 모듈형 온보드 컴퓨터 개발)

  • Oh, Hyungjik;Kim, Do-hyun;Park, Ki-Yun;Lee, Ju-in;Jung, Insun;Lee, Seonghwan;Park, Jae-Pil
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.47 no.10
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    • pp.728-737
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    • 2019
  • In this study, the minimized on-board computer (OBC) module for integrated navigation is developed, which provides satellites' relative position information in formation flying and cluster operation situations. The scalability is considered to apply the user-selected wireless communication module and Global Positioning System (GPS) receiver for navigation, while considering to meet the structural design standard of nano-satellites. As a result of the product development and production, the processing speed of integrated navigation and real-time data synchronization is satisfied for cluster operation nano-satellites by using micro controller unit (MCU). From a heat/vacuum, vibration and radiation test, the OBC was confirmed to be operated in space environments. From these results, a mass production system of OBC was made which is a key part of development on satellite formation flying and cluster/constellation missions that the community demands are increasing.

Establishment of electronic attendance using PCA face recognition (PCA 얼굴인식을 활용한 전자출결 환경 구축)

  • Park, Bu-Yeol;Jin, Eun-Jeong;Lee, Boon-Giin;Lee, Su-Min
    • Journal of the Institute of Convergence Signal Processing
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    • v.19 no.4
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    • pp.174-179
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    • 2018
  • Currently, various security technologies such as fingerprint recognition and face recognition are being developed. However, although many technologies have been developed, the field of incorporating technologies is quite limited. In particular, it is easy to adapt modern security technologies into existing digital systems, but it is difficult to introduce new digital technologies in systems using analog systems. However, if the system can be widely used, it is worth replacing the analog system with the digital system. Therefore, the selected topic is the electronic attendance system. In this paper, a camera is installed to a door to perform a Haar-like feature training for face detecting and real-time face recognition with a Eigenface in principal component analysis(PCA) based face recognition using raspberry pi. The collected data was transmitted to the smartphone using wireless communication, and the application for the viewer who can receive and manage the information on the smartphone was completed.

A Study on Noise Cancellation Model in VLC Channel caused by High Luminance of RGB LED, Using Band-Pass Optical Filters (밴드패스 광 필터를 이용한 VLC 채널의 고휘도 RGB LED 잡음 제거 모델에 관한 연구)

  • Nugmanov, Said;Khudaybergenov, Timur;Cha, Jae Sang
    • The Journal of The Korea Institute of Intelligent Transport Systems
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    • v.18 no.1
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    • pp.83-90
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    • 2019
  • LED lighting is spreading on the strength of LED lighting, and various government policies are being implemented. VLC research which is a wireless communication technology using lighting has been actively conducted, and it has been proven through many studies that a general LED light source such as a high-speed data transmitter can be used. But from now on, one of the main problems is the noise from side lights, which can be compared to the noise of radio broadcasts. So in this paper, we proposed a noise canceling model to remove the interference of ambient light by using an optical filter for a detachable VLC channel. In order to verify the proposed model, various high brightness RGB LED modules were used for comparative analysis. In addition, the applicability was verified through experiments using High Luminance LED lighting which is applied in real life.

Changes in the Industrial Structure caused by the IoT and AI (사물인터넷과 AI가 가져올 산업구조의 변화)

  • Kim, Jang-Hwan
    • Convergence Security Journal
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    • v.17 no.5
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    • pp.93-99
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    • 2017
  • Recently IoT(Internet of Things) service industry has grown very rapidly. In this paper, we investigated the changes in IoT service industry as well as new direction of human life in future global society. Under these changing market conditions, competition has been also changed into global and ecological competition. But compared to the platform initiatives and ecological strategies of global companies, Korean companies' vision of building ecosystems is still unclear. In addition, there is a need of internetworking between mobile and IoT services. IoT security Protocol has weakness of leaking out information from Gateway which connected wire and wireless communication. As such, we investigate the structure of IoT and AI service ecosystem in order to gain strategic implications and insights for the security industry in this paper.

Stream Cipher Algorithm using the Modified S-box (변형된 S박스를 이용한 스트림 암호 알고리즘)

  • 박미옥;최연희;전문석
    • Journal of the Korea Institute of Information Security & Cryptology
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    • v.13 no.5
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    • pp.137-145
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    • 2003
  • Nowadays, people can communicate with each other on any time at my place by development of wireless communications. But, the openness of mobile communications Poses serious security threats and the security is necessary on mobile communications to support the secure communication channel. The most commonly method is stream cipher for mobile communications. Generally, this stream cipher is implemented by LFSR(Linear Feedback Shift Register). On this paper proposes the modified mechanism of the S box is usually used in block cipher to advance security og the stream cipher and this mechanism is the modified three one in consideration og the randomness. Generally, S box that is function with nonlinear property makes data more strong by attack. The randomness test of the proposed algorithm is used Ent Pseudorandom Number Sequence Test Program and by the test result it proves that it has better randomness and serial correlation value than the based stream cipher on respective test.

Improvement of Indoor Positioning Accuracy using Smart LED System Implementation (스마트 LED 시스템을 이용한 실내위치인식 정밀도 개선)

  • Lee, Dong Su;Huh, Hyeong Seok
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.22 no.1
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    • pp.786-791
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    • 2021
  • In this paper, in order to minimize limitations such as signal interference and positioning errors in existing indoor positioning systems, a smart LED-based positioning system for excellent line-of-sight radio environments and precise location tracking is proposed to improve accuracy. An IEEE 802.4 Zigbee module is mounted on the SMPS board of a smart LED; RSSI and LQI signals are received from a moving tag, and the system is configured to transmit the measured data to the positioning server through a gateway. For the experiment, the necessary hardware, such as the gateway and the smart LED module, were separately designed, and the experiment was conducted after configuring the system in an external field office. The positioning error was within 70cm as a result of performing complex calculations in the positioning server after transmitting a vector value of the moving object obtained from the direction sensor, together with a signal from the moving object received by the smart LED. The result is a significantly improved positioning error, compared to an existing short-range wireless communications-based system, and shows the level at which commercial products can be implemented.

Dual Band Microstrip Antenna for Design Wimax/LTE 5G for Ship Radio Communication (선박 무선통신을 위한 Wimax/LTE 5G 용 이중대역 마이크로스트립 안테나 설계)

  • Lee, Chang Young
    • Journal of Advanced Navigation Technology
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    • v.24 no.6
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    • pp.601-606
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    • 2020
  • In this paper, we designed a microstrip patch antenna that can be applied to the Wimax/LTE 5G system among wireless media usable in coastal ships. The substrate of the proposed antenna is FR-4 (er=4.3), the size is 22 mm × 30 mm, and it can be used in the 3.5 GHz and 5.8 GHz bands of Wimax/LTE 5G by constructing a simple structure using a microstrip patch antenna. CST Microwave Studio 2014 was used for simulation, and the gain of the simulation result is 2.41dB at 2.4 GHz and 3.96 dB at 3.5 GHz. S-Parameter also showed a result of less than -10 dB (VSWR 2:1) in the desired frequency band, and designed a small variable and a miniaturized antenna so that the antenna can be used in mobile phones or electronic devices.

A Study on Activation Policy of Smart Construction Safety Cost by Analyzing Actually Estimated Amount in Safety Management Plan (스마트건설안전 비용의 안전관리계획서 계상 현황 분석을 통한 활성화 방안 연구)

  • Won, Jeong-Hun;Jang, Nam Gwon;Yu, Ji Young
    • Journal of the Korean Society of Safety
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    • v.37 no.3
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    • pp.34-44
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    • 2022
  • This study analyzed the smart construction safety cost included in safety management plans that are approved before construction. Specifically, it refers to the cost incurred in constructing and operating a safety management system using wireless communication and facilities. Based on the obtained statistical results, an activation policy for the inclusion of the smart construction safety cost in building safety management plans was proposed. The smart construction safety cost must be included in the safety management cost; notably, this is mandated by the Construction Technology Promotion Act. However, there are some problems with the inclusion of smart construction safety costs. To analyze the problems encountered when calculating the smart construction safety cost and including it in safety management plans, in this study, statistical analysis was performed using the data of 1,334 safety management plans received at the Construction Safety Management Integrated Information (CSI) from June to August 2021. The results show that only 50.7% of the safety management plans included the smart construction safety cost although the current law mandates 100% inclusion of these costs. Thus, it is apparent that the smart construction safety costs are only included in a low proportion of sites. In addition, the calculated smart construction safety costs were shown to have a small correlation with the construction cost; moreover, they appeared to be distributed at a constant cost level. In this context, it is believed that perfunctory cost calculations were performed at most sites since the effect of the construction cost on the smart construction safety cost was negligible. Therefore, it is necessary to improve the inclusion of smart construction safety costs by strengthening the authorization process of the approval institute of safety management plans. In addition, institutional support, such as guidelines that promote the calculation and inclusion of appropriate smart construction safety costs according to the characteristics of sites, are needed.