• Title/Summary/Keyword: 무선통신망

Search Result 899, Processing Time 0.023 seconds

Fan-shaped Search Zone Routing Protocol for Ship Ad Hoc Networks (선박 애드 혹 네트워크를 위한 부채꼴 탐색구역 경로배정 프로토콜)

  • Son, Joo-Young
    • Journal of KIISE:Information Networking
    • /
    • v.35 no.6
    • /
    • pp.521-528
    • /
    • 2008
  • Such conventional maritime communication technologies as radio have short some comings in their transmission quality. It can be overcome by wireless channels provided by satellites such as INMARSAT, which nevertheless suffer from the high costs. In this paper, we propose a novel technology resolving the above problems, featuring in the establishment of maritime communication networks with multi-hop structures. The inter vessel and ship-to- shore networks previously modeled after MANET are remodeled by SANET (Ship Ad Hoc Networks) in the present work. Fan-shaped Search Zone Routing (FSR) protocol also is presented, which utilizes not only static geographical information including the locations of ports and the navigations of courses but also the unique characteristics of ships in terms of mobile nodes. The FSR finds the fan-shaped search zone on which the shortest path is located. The performance of LAR protocol is compared with that of FSR in several ways. First, FSR does not make use of a type of control packets as beaconing data, resulting in a full utilization of the bandwidth of the wireless channels. Second, the delivery rate by the FSR is 100% for the fan-shaped search zone includes at least one route between source and destination nodes on its border line, where as that of LAR has been turned out to be 64%. Third, the optimality of routes searched by the FSR is on a 97% level. Of all, the FSR shows a better performance than LAR by about 50%.

A study on the new developmental direction for Intelligent Network Service (지능망서비스의 발전방향에 관한 연구)

  • 박민수;최수길
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
    • /
    • 2000.05a
    • /
    • pp.43-49
    • /
    • 2000
  • That modem society is an information society, information society has placed a high value on information and knowledge. Therefore, modem civilization depends largely on information and knowlege so the most valuable sources of all intelligence activities. This paper was studied on the new developmental direction for intelligent network service. The results of this study is as follow: first, intelligent network service must be systematic development. Second, intelligent network service must be promoted, presenting the development and establishment direction in future society. Third, intelligent network service must be able to unify ail the networks. Fourth, intelligent network service must be development for customers. Fifth, the cost of intelligent network service is determined by Telecommunication Reguration Commission. Sixth, the number system of intelligent network service must be accomplished by number system for future

  • PDF

An Adaptive Load Control Scheme in Hierarchical Mobile IPv6 Networks (계층적 모바일 IP 망에서의 적응형 부하 제어 기법)

  • Pack Sang heon;Kwon Tae kyoung;Choi Yang hee
    • The Journal of Korean Institute of Communications and Information Sciences
    • /
    • v.29 no.10A
    • /
    • pp.1131-1138
    • /
    • 2004
  • In Hierarchical Mobile Ipv6 (HMIPv6) networks, the mobility anchor point (MAP) handles binding update (BU) procedures locally to reduce signaling overhead for mobility. However, as the number of mobile nodes (MNs) handled by the MAP increases, the MAP suffers from the overhead not only to handle signaling traffic but also to Process data tunneling traffic. Therefore, it is important to control the number of MNs serviced by the MAP, in order to mitigate the burden of the MAP. We propose an adaptive load control scheme, which consists of two sub-algorithms: threshold-based admission control algorithm and session-to-mobility ratio (SMR) based replacement algorithm. When the number of MNs at a MAP reaches to the full capacity, the MAP replaces an existing MN at the MAP, whose SMR is high, with an MN that just requests binding update. The replaced MN is redirected to its home agent. We analyze the proposed load control scheme using the .Markov chain model in terms of the new MN and the ongoing MN blocking probabilities. Numerical results indicate that the above probabilities are lowered significantly compared to the threshold-based admission control alone.

Technical Advances in Robotic Pavement Crack Sealing Machines and Lessons Learned from the Field (도로면 유지보수를 위한 크랙실링 자동화 로봇의 개발과 응용 -현장적용을 통한 실험 결과 분석을 중심으로-)

  • Kim Young-Suk;Carl T. Haas;Sung Baek-Jun;Oh Se-Wook
    • Korean Journal of Construction Engineering and Management
    • /
    • v.1 no.1 s.1
    • /
    • pp.87-94
    • /
    • 2000
  • Crack sealing, a routine and necessary part of pavement maintenance, is a dangerous, costly, and labor-intensive operation. Within the North America, about ${\$}200$ million is spent annually on crack sealing, with the Texas Department of Transportation (TxDOT) spending about ${\$}7$ million annually (labor alone accounts for over 50 percent of these costs). Prompted by concerns of safety and cost, the University of Texas at Austin, in cooperation with TxDOT and the Federal Highway Administration (FHWA) has developed a unique computer-guided Automated Road Maintenance Machine (ARMM) for pavement crack sealing. In 1999, successful field tests have been undertaken in 8 States around the U.S. This paper first describes significance of the automated crack sealing and technical advances in automated crack sealers including the ARMM, developed in the U.S. It then discusses the ARMM's field implementation and performance evaluation results, and improvements and modifications suggested through the technology evaluation during the field trials. Current research efforts and future work plans in its further development are also presented in this paper.

  • PDF

Real-Time Construction Resource Monitoring using RFID/USN Inter-working System (RFID/USN 연동 시스템을 활용한 건설자원 실시간 모니터링 시스템)

  • Ryu, Jeoung-Pil;Kim, Hyoung-Kwan;Kim, Chang-Yoon;Kim, Chang-Wan;Han, Seung-Heon;Kim, Moon-Kyum
    • Proceedings of the Korean Institute Of Construction Engineering and Management
    • /
    • 2007.11a
    • /
    • pp.90-94
    • /
    • 2007
  • Location tracking automation of resources in construction industry is one of the most important procedures to improve construction project performance and reduce the period of construction. Recently, location tracking technologies have proven to be effective in tracking construction materials and equipment in real time through the instrumentality of RFID (Radio Frequency Identification). By using wireless communication and inter-working system between RFID and USN, it is possible that construction engineers receive the location information of construction resources without additional efforts that move the RFID reader to read tags periodically. In the inter-working system, RFID reader delivers the acquired materials information to sensor node which is connected by serial interface. Then sensor node transmits the received data to the data aggregation terminal that is a sink node. The data aggregation terminal can transmit collected data to construction manager who is out of construction site using infrastructure such as CDMA(Code Division Multiple Access) network. The combination model of the two system and field test scenarios are presented in this paper.

  • PDF

Studies of the possibility of external threats of the automotive ECU through simulation test environment (자동차용 ECU의 CAN 메시지를 통한 자동차 공격 방법 연구)

  • Lee, Hye-Ryun;Kim, Kyoung-Jin;Jung, Gi-Hyun;Choi, Kyung-Hee;Park, Seung-Kyu;Kwon, Do-Keun
    • Journal of the Korea Society of Computer and Information
    • /
    • v.18 no.11
    • /
    • pp.39-49
    • /
    • 2013
  • In this paper, security mechanism of internal network(CAN) of vehicle is a very incomplete state and the possibility of external threats as a way to build a test environment that you can easily buy from the market by the vehicle's ECU(Electric Control Unit) to verify and obtain a CAN message. Then, by applying it to ECU of the real car to try to attack is proposed. A recent study, Anyone can see plain-text status of the CAN message in the vehicle. so that in order to verify the information is vulnerable to attack from outside, analyze the data in a vehicle has had a successful attack, but attack to reverse engineering in the stationary state and buying a car should attempt has disadvantages that spatial, financial, and time costs occurs. Found through the car's ECU CAN message is applied to a real car for Potential threats outside of the car to perform an experiment to verify and equipped with a wireless network environment, the experimental results, proposed method through in the car to make sure the attack is possible. As a result, reduce the costs incurred in previous studies and in the information absence state of the car, potential of vehicle's ECU attack looks.

A Study on the Analysis of R&D Trends and the Development Plan of Electronic Attack System (전자공격체계 연구개발 동향 분석과 발전방안에 대한 연구)

  • Sim, Jaeseong;Park, Byoung-Ho
    • Journal of the Korea Academia-Industrial cooperation Society
    • /
    • v.22 no.6
    • /
    • pp.469-476
    • /
    • 2021
  • An electronic attack (EA) system is an essential weapon system for performing electronic warfare missions that contain signal tracking and jamming against multiple threats using electromagnetic waves, such as air defense radars, wireless command and communication networks, and guided missiles. The combat effectiveness can be maximized, and the survivability of militarily protecting combat power can be enhanced through EA mission operations, such as disabling the functions of multiple threats. The EA system can be used as a radio frequency jamming system to respond to drone attacks on the core infrastructure, such as airports, power plants, and communication broadcasting systems, in the civilian field. This study examined the criteria for classification according to the electronic attack missions of foreign EA systems based on an aviation platform. The foreign R&D trends by those criteria were investigated. Moreover, by analyzing the R&D trends of domestic EA systems and future battlefields in the domestic security environments, this paper proposes technological development plans of EA systems suitable for the future battlefield environments compared to the foreign R&D trends.

Improvement of Encoding Detection Algorithm for Multi-byte Encoded Data with Errors (오류가 발생한 멀티바이트 인코딩 데이터의 인코딩 기법 판별 알고리즘 개선)

  • Bae, Junwoo;Kim, Seonbeom;Park, Heejin
    • The Journal of Korean Institute of Next Generation Computing
    • /
    • v.13 no.2
    • /
    • pp.18-25
    • /
    • 2017
  • In computer science, an encoding is a standardization of converting information to one format for audio, video or text. Therefore, the encoding information of the data should be known to open and read it and there are algorithms detecting encoder of the data. However, some informations of data could be disappeared by packet loss when transmitted on network, especially, if the data is snatched by packet sniffing or eavesdropping from wireless communications. In this paper, we improve the performance of encoding detection algorithm of 'uchardet' program for multi-byte encoded data with errors based on bit-shift algorithm. To simulate the performance, we generated Korean and Japanese text data with errors that is removed some random bits at random positions. Then the detection algorithm are tested using the data and 'uchardet-bitshift' showed better performance than 'uchardet'. When Korean texts are used, 'uchardet' could detect perfectly with ≤0.005% errors but it showed 0% detection rate with ≥1% errors while 'uchardet-bitshift' detected perfectly with ≤0.05% errors and it showed correct detection cases with ≥1% errors. Japanese texts with errors tend to report falsely as Chinese encoding because Japanese texts include lots of Chinese characters. As a results, we improved encoding detection algorithms by applying bit shift operation.

Performance Evaluation of Advance Warning System for Transporting Hazardous Materials (위험물 운송을 위한 조기경보시스뎀 성능평가)

  • Oh Sei-Chang;Cho Yong-Sung
    • The Journal of The Korea Institute of Intelligent Transport Systems
    • /
    • v.4 no.1 s.6
    • /
    • pp.15-29
    • /
    • 2005
  • Truck Shipment Safety Information, which is a part of the development of NERIS is divided into Optimal Route Guidance System and Emergency Response System. This research is for establishing an advance warning system, which aims for preventing damages(fire, explosion, gas-escape etc.) and detecting incidents that are able to happen during transporting hazardous materials in advance through monitoring the position of moving vehicles and the state of hazardous materials in real-time. This research is peformed to confirm the practical possibility of application of the advance warning system that monitors whether the hazardous materials transport vehicles move the allowed routes, finds the time and the location of incidents of the vehicles promptly and develops the emergency system that is able to respond to the incidents as well by using the technologies of CPS, CDMA and CIS with testing the ability of performance. As the results of the test, communication accuracies are 99$\%$ in freeway, 96$\%$ in arterial, 97$\%$ in hilly sections, 99$\%$ in normal sections, 96$\%$ in local sections, 99$\%$ in urban sections and 98$\%$ in tunnels. According to those results, the system has been recorded a high success rate of communication that enough to apply to the real site. However, the weak point appeared through the testing is that the system has a limitation of communication that is caused in the rural areas and certain areas where are fewer antennas that make communication possible between on-board unit and management server. Consequently, for the practical use of this system, it is essential to develop the exclusive en-board unit for the vehicles and find the method that supplements the receiving limitation of the GPS coordinates inside tunnels. Additionally, this system can be used to regulate illegal acts automatically such as illegal negligence of hazardous materials. And the system can be applied to the study about an application scheme as a guideline for transporting hazardous materials because there is no certain management system and act of toxic substances in Korea.

  • PDF