• 제목/요약/키워드: Safe Network

검색결과 596건 처리시간 0.024초

4대강 주변 하천모니터링을 위한 무선 메쉬 네트워크 전파환경 분석 및 구축(합천보 중심으로) (Propagation Environment Analysis and Wireless Mesh Network Implementation for monitoring the Four Rivers (based on Hapcheon weir))

  • 홍성택;진력민
    • 한국인터넷방송통신학회논문지
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    • 제12권6호
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    • pp.127-134
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    • 2012
  • 우리나라의 4대강 사업은 홍수피해와 물부족을 근본적으로 해결하고 수질개선과 하천복원으로 건전한 수생태계 조성은 물론 국민 여가문화 수준 및 삶의 질 향상을 도모하고자 하였으며, 안정적인 하천관리를 위해서 수십 km ~ 수백 km에 이르는 하천지역의 각종 관측데이터를 모니터링하는 것이 필수적이다. 4대강 사업중 낙동강 권역의 합천보는 총 21.21 km 구간으로 무선 네트워크의 하나인 무선 메쉬망을 자체망을 구축하였다. 망 구축시 주변 지역의 특성을 고려하여 최소비용으로 안정적인 서비스를 구현하기 위하여 LOS 시험 및 수신레벨 분석, 통신속도 측정 등 전파 환경 분석을 실시하였으며, 모든 개소에서 수신레벨이 -55 dBm ~ -70 dBm 되는 것을 확인하였으며, 데이터 전송속도도 20 Mbps 이상이 되는 것을 확인하였다. 이는 기존 상용망이 가지는 전송속도, 음영지역의 문제를 해결할 수 있을 뿐만 아니라 망관리시스템을 통하여 상시 망 관리를 통하여 안정적인 서비스를 구현할 수 있도록 함으로써 무선 메쉬 네트워크가 하천 모니터링 서비스와 같은 국가 Infra에도 널리 이용 가능함을 보여주고 있다.

장애물 패턴을 이용한 자율이동로봇의 예측주행 및 충돌회피 알고리즘 개발 (Development of an Algorithm for Predictable Navigation and Collision Avoidance Using Pattern Recognition of an Obstacle in Autonomous Mobile Robot)

  • 이민철;김범재;이석
    • 한국정밀공학회지
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    • 제17권7호
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    • pp.113-123
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    • 2000
  • In the navigation for a mobile robot, the collision avoidance with unexpected obstacles is essential for the safe navigation and it is independent of the technique used to control the mobile robot. This paper presents a new collision avoidance algorithm using neural network for the safe navigation of the autonomous mobile robot equipped with CAN and ultrasonic sensors. A tracked wheeled mobile robot has a stability and an efficiency to move on a rough ground. And its mechanism is simple. However it has difficulties to recognize its surroundings. Because the shape of the tracked wheeled mobile robot is a square type, sensor modules are generally located on the each plane surface of 4 sides only. In this paper, the algorithm using neural network is proposed in order to avoid unexpected obstacles. The important character of the proposed algorithm is to be able to detect the distance and the angle of inclination of obstacles. Only using datum of the distance and the angle, informations about the location and shape of obstacles are obtained, and then the driving direction is changed. Consequently, this algorithm is capable of real time processing and available for a mobile robot which has few sensor modules or the limited sensing range such as a tracked wheeled mobile robot. Effectiveness of the proposed algorithm is illustrated through a computer simulation and an experiment using a real robot.

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Reliable Ethernet Architecture with Redundancy Scheme for Railway Signaling Systems

  • Hwang, Jong-Gyu;Jo, Hyun-Jeong
    • Journal of Electrical Engineering and Technology
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    • 제2권3호
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    • pp.379-385
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    • 2007
  • Recently, vital devices of the railway signaling systems have been computerized in order to ensure safe train operation. Due to this computerization, we have gradually come to need networking interfaces between these devices. Thus it is important that there be reliable communication links in the signaling systems. Network technologies are applied in the real-time industrial control system, and there are numerous studies to be carried out on the computer network technology for vital control systems such as railway signaling systems. For deploying the studies, we consider costs, reliability, safety assurance technique, compatibility, and etc. In this paper, we propose the Ethernet for railway signaling systems and also precisely describe the computer network characteristics of vital railway signaling systems. Then we demonstrate the experimental results of the proposed network algorithm, which is based on switched Ethernet technology with redundancy scheme.

Development of integrated marine monitoring network on southern coastline of Caspian sea

  • Najafi-Jilani, A.;Nik-Khah, A.
    • International Journal of Naval Architecture and Ocean Engineering
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    • 제3권2호
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    • pp.136-140
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    • 2011
  • Monitoring of water surfaces through permanent measurement of hydrodynamic and meteorological data is one of the main requirements in safe and sustainable water management. The Caspian Sea, the major surface water body in Iran, significantly affects more than 600 km of urban and industrial coastline. In the present work, an integrated marine monitoring network for the entire southern coastline of the Caspian Sea was developed. The main design concerns centered on the network measuring components and data recording, checking, filtering, gap recognition, and transferring systems. Four coastal monitoring stations were assigned, along with two regional collecting stations and one central data station for gathering, checking and delivering recorded data at different access levels. Applicable guidelines on selection of measuring devices for both shallow and deep water zones are presented herein.

AAA가 적용된 네트워크의 인증에 대한 검증 사례연구 (A Verification Case Study about the Authentication of a Network using AAA)

  • 박성배;김노환
    • 한국전자통신학회논문지
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    • 제12권2호
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    • pp.295-300
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    • 2017
  • AAA는 사용자에 대한 안전하고 신뢰성 있는 인증(Authentication)을 통해 사용자에게 주어진 권한과 서비스 수준을 결정하여 인가(Authorization)하고, 사용자 자원의 사용정보를 과금, 감사, 리포팅 등을 위한 계정관리(accounting) 기능을 체계적으로 통합 관리하는 정보보호 프로토콜이다. 본 논문에서는 RADIUS와 TACACS+가 적용된 라우터와 서버 기반의 네트워크를 설계하기 위해 토폴로지를 설계한 후 패킷 트레이서를 이용하여 공통 가상 망을 구현한 다음, 시뮬레이션을 통해서 인증에 대한 검증구현 사례를 제시하였다.

Adaptive Wireless Sensor Network Technology for Ubiquitous Container Logistics Development

  • Chai, Bee-Lie;Yeoh, Chee-Min;Kwon, Tae-Hong;Lee, Ki-Won;Lim, Hyotaek;Kwark, Gwang-Hoon
    • 한국정보통신학회:학술대회논문집
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    • 한국해양정보통신학회 2009년도 춘계학술대회
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    • pp.317-320
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    • 2009
  • At the present day, the use of containers crisscrossing seven seas and intercontinental transport has significantly increased and bringing the change on the shape of the world economy which we cannot be neglected. Additionally, with the recent technological advances in wireless sensor network (WSN) technologies, has providing an economically feasible monitoring solution to diverse application that allow us to envision the intelligent containers represent the next evolutionary development step in order to increase the efficiency, productivity, utilities, security and safe of containerized cargo shipping. This paper we present a comprehensive containerized cargo monitoring system which has adaptively embedded WSN technology into cargo logistic technology. We share the basic requirement for an autonomous logistic network that could provide optimum performance and a suite of algorithms for self-organization and bi-directional communication of a scalable large number of sensor node apply on container regardless inland and maritime transportation.

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Predicting the Saudi Student Perception of Benefits of Online Classes during the Covid-19 Pandemic using Artificial Neural Network Modelling

  • Beyari, Hasan
    • International Journal of Computer Science & Network Security
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    • 제22권2호
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    • pp.145-152
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    • 2022
  • One of the impacts of Covid-19 on education systems has been the shift to online education. This shift has changed the way education is consumed and perceived by students. However, the exact nature of student perception about online education is not known. The aim of this study was to understand the perceptions of Saudi higher education students (e.g., post-school students) about online education during the Covid-19 pandemic. Various aspects of online education including benefits, features and cybersecurity were explored. The data collected were analysed using statistical techniques, especially artificial neural networks, to address the research aims. The key findings were that benefits of online education was perceived by students with positive experience or when ensured of safe use of online platforms without the fear cyber security breaches for which recruitment of a cyber security officer was an important predictor. The issue of whether perception of online education as a necessity only for Covid situation or a lasting option beyond the pandemic is a topic for future research.

SmartX-mini Playground 상의 IoT-Cloud 서비스에 대한 SDN 기반 모니터링 데이터 수집 경로 설정 (SDN-Based Collection-path Steering for IoT-Cloud Service Monitoring Data over SmartX-mini Playground)

  • 윤희범;김승룡;김종원
    • 한국통신학회논문지
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    • 제41권11호
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    • pp.1598-1607
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    • 2016
  • 부상하는 IoT-Cloud 서비스들을 효율적으로 지원하기 위해서는 IoT-Cloud 간의 안정적이고 지속적인 데이터 전송이 필수적이다. 본 논문에서는 초융합형 SmartX Box에 기반한 SmartX-mini Playground 상에서 IoT-Cloud 서비스를 위한 다양한 모니터링 데이터를 보다 안정되게 수집/전송함에 있어서 오픈소스 메시징 시스템인 Kafka를 활용하고 ONOS(Open Network Operation System) SDN 제어기에 기반한 SDN 응용을 적용함으로써 실제적인 IoT-SDN-Cloud 환경에서의 안정적인 IoT-Cloud 서비스에 대응하는 모니터링 데이터 전송을 위한 유연한 수집 경로 설정이 가능함을 확인한다.