• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2001년도 ICCAS
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• pp.40.1-40
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• 2001

In this paper, control theoretic approaches are proposed to guarantee QoS (Quality of Series) such as packet delay and packet loss of real-time traffic in high-speed communication network. Characteristics of variable rate real-time traÆc in communication networks are described. The mathematical model describing networks including source and destination nodes are suggested. By a traffic control mechanism, it is shown that worst-case end-to-end transfer delay of traffic can be controlled and packet loss can be prevented. The simulation shows results of delay control and buer level control to raise QoS in realtime traffic.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제12권6호
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• pp.2492-2512
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• 2018

Multicast communication can effectively reduce network resources consumption in contrast with unicast. With the advent of SDN, current researches on multicast traffic are mainly conducted in the SDN scenario, thus to mitigate the problems of IP multicast such as the unavoidable difficulty in traffic engineering and high security risk. However, migration to SDN cannot be achieved in one step, hybrid SDN emerges as a transitional networking form for ISP network. In hybrid SDN, for acquiring similar TE and security performance as in SDN multicast, we redirect every multicast traffic to an appropriate SDN node before reaching the destinations of the multicast group, thus to build up a core-based multicast tree substantially which is first introduced in CBT. Based on the core SDN node, it is possible to realize dynamic control over the routing paths to benefit traffic engineering (TE), while multicast traffic manageability can also be obtained, e.g., access control and middlebox-supported network services. On top of that, multiple core-based multicast trees are constructed for each multicast group by fully taking advantage of the routing flexibility of SDN nodes, in order to further enhance the TE performance. The multicast routing and splitting (MRS) algorithm is proposed whereby we jointly and efficiently determine an appropriate core SDN node for each group, as well as optimizing the traffic splitting fractions for the corresponding multiple core-based trees to minimize the maximum link utilization. We conduct simulations with different SDN deployment rate in real network topologies. The results indicate that, when 40% of the SDN switches are deployed in HSDN as well as calculating 2 trees for each group, HSDN multicast adopting MRS algorithm can obtain a comparable TE performance to SDN multicast.

• International Journal of Internet, Broadcasting and Communication
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• 제12권4호
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• pp.71-82
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• 2020

Traffic accidents due to excessive speed frequently occur in places where traffic signal controllers are installed, places where sharp curves exist, or places where the traffic signal cycle does not match the current time. These traffic accidents cause economic loss due to the destruction of road facilities and structures, and cause a big problem of increasing the number of traffic accident deaths. When a traffic accident occurs, leaving a tire mark before or after a car crash, pre-collision speed of the car is calculated using the law of conservation of momentum or the skid mark formula. In the skip skid mark generated in ABS brake vehicles and the combshaped yaw mark generated by tire trace caused by lateral sliding, there is a difference of 30-40% in the reliability of the vehicle speed calculated by the smite mark. In this paper, we propose an algorithm that can improve the calculation reliability in vehicle speed by using skid marks in order to compensate for this problem. In addition, we present an intelligent speed calculation algorithm for traffic safety and a computer simulation in order to prevent traffic accidents by estimating the speed of a vehicle, using Skid marks, Yaw marks, and ABS brake characteristics and fuzzy rules.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2005년도 춘계종합학술대회
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• pp.105-108
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• 2005

최근 급속히 증가하는 데이터 트래픽을 지원할 수 있도록 네트웍을 관리해야 할 뿐만 아니라 안정적인 인프라를 유지하기 위해 트래픽 엔지니어링을 지원할 수 있는 MPLS가 필요하게 되었다. 트래픽 엔지니어링은 대규모 사용자가 트래픽을 네트웍 상의 특정 노드를 지나는 사전 지정된 경로로 이동시키는 방법으로 트래픽 플로우를 물리적인 네트웍 토폴로지에 매핑시키는 작업이라고 할 수 있다. 본 논문에서는 기존 RSVP의 트래픽 엔지니어링의 단점을 보완하고 보다 안정된 인프라를 구축하기 위해 ERSVP 시그널링 프로토콜에 대한 진화방향을 제시하고져 한다.

• Journal of Information Processing Systems
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• 제6권3호
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• pp.307-322
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• 2010

Traffic classification is an essential task for network management. Many researchers have paid attention to initial sub-flow features based classifiers for traffic classification. However, the existing classifiers cannot classify traffic effectively in mobile IP networks. The classifiers depend on initial sub-flows, but they cannot always capture the sub-flows at a point of attachment for a variety of elements because of seamless mobility. Thus the ideal classifier should be capable of traffic classification based on not only initial sub-flows but also various types of sub-flows. In this paper, we propose a classifiable sub-flow selection method to realize the ideal classifier. The experimental results are so far promising for this research direction, even though they are derived from a reduced set of general applications and under relatively simplifying assumptions. Altogether, the significant contribution is indicating the feasibility of the ideal classifier by selecting not only initial sub-flows but also transition sub-flows.

• 한국인터넷방송통신학회논문지
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• 제16권1호
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• pp.209-214
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• 2016

IEC 61850은 변전소 자동화 시스템의 설계, 설치 및 유지하는 비용을 줄이는 프로토콜이다. IEC 61850에서 사용되는 GOOSE 트래픽은 변전소 제어, 보호, 자동화를 위해 중요한 역할을 담당한다. 본 논문에서는 네트워크 시뮬레이터인 NS-3에서 제공하는 프로토콜과 실제 통신장비에서 제공하는 프로토콜을 함께 사용하여, NS-3의 네트워크 에뮬레이션 기능을 이용한 GOOSE 트래픽 발생기를 구현하였다. 발생한 GOOSE 트래픽을 Wireshark으로 분석하였고, 정확히 발생됨을 확인하였다. 네트워크 토폴로지의 스위치 수에 따른 GOOSE 트래픽 지연 측정을 하였다. 본 논문에서의 GOOSE 트래픽 발생기는 실제 변전소 환경을 실험할 때 유용하게 활용될 수 있을 것이다.

• 한국인터넷방송통신학회논문지
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• 제22권6호
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• pp.13-20
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• 2022

겨울철 도로에서 발생하는 안개 및 결빙구간 교통사고 사망률의 경우는 도로조건 및 기상조건이 매우 중요한 요소 이다. 본 논문에서는 교통사고 예측 데이터를 가정하고 교통사고 위험율을 에측 하는 모의실험을 수행하였다. 그뿐만 아니라, 본 논문에서는 교통사고를 줄이고 교통사고를 예방하기 위해서, 교통공단에서 제공하는 교통사고 사망자 데이터를 WEKA 데이터 마이닝 기법 및 TENSOR FLOW 공개 소스를 이용해서 요인 분석 및 교통사고 치사율 사망을 예측하였다. 추가적인 기능으로는 지도 표시 기능을 이용해서, 운전자가 WEB 기반에서, 안개 및 결빙구간 정보를 운전자에게 제공하는 모의실험 및 교통사고 사진을 실시간으로 전송하는 모의실험 결과를 설명하였다.

• 한국정보통신학회논문지
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• 제26권12호
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• pp.1934-1937
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• 2022

The meaning of crosswalks and traffic lights in modern society has changed a lot as the enforcement of traffic signal violations has been strengthened. In this paper, we present a new next-generation traffic light method using radar and Can-bus communication methods suitable for the new traffic signal enforcement system. This method is a system that prevents accidents by transmitting information on the entry of a person and a car to a traffic light in a place where a person and a car passing through a mutually invisible traffic light cannot be seen. Since this system has only been developed for a month, it may be somewhat lacking in experimentation. However, in just one month, there have been no incidents except for a few people where the system has been installed.

• 한국ITS학회 논문지
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• 제18권6호
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• pp.43-59
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• 2019

현재 국내에서 사용되고 있는 교통신호제어기는 220V의 고전압을 신호등에 일대일로 직접 전달하는 스위치 제어 방식이다. 이러한 방식은 교통신호제어기와 신호등들을 연결하는 데 상대적으로 많은 케이블이 소요되고, 또한 감전에 대한 우려가 있다. 이에 따라 도로교통공단에서는 경찰청 교통신호제어기 표준규격서에 디지털 통신 방식을 이용한 디지털 교통신호제어기의 규격을 추가하였다. 본 연구에서는 이러한 표준규격서를 바탕으로 디지털 교통신호제어기를 개발하고자 하였다. 또한 디지털 교통신호제어기와 아날로그 교통신호제어기가 혼재되어 있어도 현재 운영 중인 신호제어시스템에서 운영이 가능함을 검증하였다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제15권1호
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• pp.114-130
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• 2021

With the drastic growth of Information and Communication Technology (ICT) industry, global energy consumption is exponentially increased by mobile communications. The huge energy consumption and increased environmental awareness have triggered great interests on the research of dynamic distribution of cell user and traffic, and then designing the energy efficient cellular network. In this paper, we explore the temporal and spatial characteristics of human mobility and traffic distribution using real data set. The analysis results of cell traffic illustrate the tidal effect in temporal and spatial dimensions and obvious periodic characteristics which can be used to design Base Station (BS) dynamic with sleeping or shut-down strategy. At the same time, we designed a new Cell Zooming and BS cooperation mode. Through simulation experiments, we found that running in this mode can save about 35% of energy consumption and guarantee the required quality of service.