• 한국통신학회논문지
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• 제27권4C호
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• pp.316-325
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• 2002

This paper investigates the restoration schemes which are applied to the MPLS domain upon a network failure. We define the following three restoration service models by combining the various restoration schemes: "FIS-based protection service" (FIS: failure indication signal), "inversion traffic protection service" and "1+1 protection service". After a qualitative analysis of the performance in them, we have analyzed it on quantitative basis by the simulation. According to the simulation results, "1+1 protection service" guarantees the fastest and most lossless restoration service among them; however, it results in consuming considerable bandwidth and producing an amount of control traffic, which means poor network utilization. On the other hand, "FIS-based protection service" spends less bandwidth and generates less control traffic, which means better network utilization, but produces poor restoration service. "Inversion traffic protection service" provides the medium restoration service and utilization between "1+1 protection service" and "FIS-based protection service."

• Journal of Communications and Networks
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• 제12권6호
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• pp.624-631
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• 2010

Effective traffic matrix estimation is the basis of efficient traffic engineering, and therefore, quality of service provision support in IP networks. In this study, traffic matrix estimation is investigated in IP networks and an Elman neural network-based traffic matrix inference (ENNTMI) method is proposed. In ENNTMI, the conventional Elman neural network is modified to capture the spatio-temporal correlations and the time-varying property, and certain side information is introduced to help estimate traffic matrix in a network accurately. The regular parameter is further introduced into the optimal equation. Thus, the highly ill-posed nature of traffic matrix estimation is overcome effectively and efficiently.

• 한국통신학회논문지
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• 제29권7B호
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• pp.641-649
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• 2004

홈 네트워크에서 다양한 응용(application) 트래픽(traffic) 간의 차등화 된 서비스를 제공하기 위해서 트래픽 변화에 따라 적응적으로 우선순위(priority)를 재할당하는 알고리즘을 제안하고, FPGA를 이용하여 구현하였다. 제안된 구조는 QoS를 위한 부가적인 시그널링 프로토콜이 없이도 네트워크 트래픽 조절이 가능하도록 설계되었고, 또한 홈 네트워크 트래픽을 그 특징에 따라 제어 데이터 트래픽, 일반 인터넷이나 데이터 트래픽, 그리고 멀티미디어 데이터 트래픽으로 분류하고 이를 네트워크 트래픽 상황에 적응적으로 차등화 서비스를 제공할 수 있도록 설계되었다. 시뮬레이션을 통하여 제시한 알고리즘의 성능을 검증하고 FPGA구현을 통하여 실현가능성을 제시하였다.

• 한국ITS학회:학술대회논문집
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• 한국ITS학회 2007년도 제6회 추계학술대회 및 정기총회
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• pp.244-250
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• 2007

• Journal of information and communication convergence engineering
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• 제5권2호
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• pp.171-176
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• 2007

To give a guarantee a consistently high level of quality and reliability of Telematics traffic service, traffic flow forecasting is very important issue. In this paper, we proposed an adaptable integrated prediction model to predict the traffic flow in the future. Our model combines two methods, short-term prediction model and long-term prediction model with different combining coefficients to reflect current traffic condition. Short-term model uses the Kalman filtering technique to predict the future traffic conditions. And long-term model processes accumulated speed patterns which means the analysis results for all past speeds of each road by classifying the same day and the same time interval. Combining two models makes it possible to predict future traffic flow with higher accuracy over a longer time range. Many experiments showed our algorithm gives a better precise prediction than only an accumulated speed pattern that is used commonly. The result can be applied to the car navigation to support a dynamic shortest path. In addition, it can give users the travel information to avoid the traffic congestion areas.

• 한국컴퓨터산업학회논문지
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• 제9권3호
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• pp.121-128
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• 2008

본 논문에서는 TPEG와 GIS를 이용한 위치기반 교통정보 서비스 시스템을 제안하여 구현한다. 위치기반 서비스를 제공하기 위하여 측정기술과 위치서버, 응용서비스기술, DB와의 연동기술 등을 사용한다, TPEG-RTM 메시지는 위치정보 및 도로교통 메시지를 포함하고 있다. 각 메시지에 포함되는 위치정보는 도로의 특정지점, 구간 또는 지역범위 등으로 나타난다. 따라서, 본 논문을 구현함에 있어서 TPEG 수신기를 사용한 데이터 수신이 불가능하므로 임의의 DB를 생성하고 이를 읽어들이는 방식을 사용한다. TPEG 메시지와 수신한 WGS84 좌표의 매칭 테스트를 위해서 지도상에 TPEG 이벤트 발생시점을 표시하고 차량이 이벤트 발생시점으로 다가가는 예제를 가지고 검증한다.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2004년도 Proceedings of ISRS 2004
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• pp.280-282
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• 2004

According as IT environment changes from client/server system to the open system based on web service technologies, the exchange of data and services between independent applications and service servers in web environment is observed Recently. In this points, it is necessary that Geographic Information Systems, Spatial Imagery Information Systems, Intelligent Transportation Systems, and Global Navigation Satellite Systems based on the location and geometry information are inter-related each other. But, the inter-relation of these systems is very difficult because of the closed system architecture, different information format, and the absence of interoperability technologies. In this Paper, we describe 4S integration system based web service technologies that accept the international standard as WFS, WCS, WRS of OGC (OpenGIS Consortium) and UDDI, SOAP, WSDL of W3C. In detail, we study the system architecture design and implementation of traffic information service, routing service, and tracing service. These services are consisting of the data schema based on XML and GML, various functions of each layered service, each server platform, and web server. Specially, we represent that GML is being applied to a wide range of location-based services, telematics, and intelligent transportation

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 1998년도 하계종합학술대회논문집
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• pp.86-89
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• 1998

Multiple types of information in a multimedia service are delivered though multiple virtual connections on ATM network, while each virtual connection may be controlled independently. A multimedia service requires an associative relationship among multiple information streams to provide required harmonization. There may be required additional traffic descriptors to guarantee the required harmonization among multiple information streams in a multimedia service. For buffering of large bandwidth information stream(e.g., video), extremely large buffer size is necessary, but this approach should not be efficient way to compensate a severely delayed cells/blocks experienced at network. The best way to solve this problem will be minimization of relative-delayed-transfer of cells/blocks to application processes through ATM network control. To minimize a delayed transfer the mapping between relative delay parameter(i.e., associative Group QoS parameters) and per-VC traffic descriptor will be necessary. This paper is present additional functions and parameters to interpret the mapping between relative delay parameters(i.e., associative Group QoS parameters) and per-VC traffic descriptors in ATM API for multimedia application services.

• 한국정보통신설비학회:학술대회논문집
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• 한국정보통신설비학회 2005년도 하계학술대회
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• pp.109-112
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• 2005

In this thesis, we recommend the method for VOD service traffic modeling. By the analysis of service traffic, we verify that the process of VOD service is the POISSON process. So it is important to determine the probability of the user's existence in the system. But, because it is difficult to measure, we recommend proper using of arrival rate and service rate.

• 한국컴퓨터정보학회논문지
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• 제14권6호
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• pp.153-164
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• 2009

본 연구의 목적은 일반국도를 대상으로 첨단교통정보서비스(ATIS: Advanced Traffic Information Services)를 제공하는 일환으로 노변방송시스템 구축방안을 제시하는데 있다. 노변방송은 소통 정보 제공을 통한 통행의 분산유도 뿐 만 아니라 전방의 홍수, 폭설, 낙석, 도로유실, 붕괴 등과 같은 자연재해 및 긴급상황 발생시 관련 정보를 시의 적절하게 제공함으로써 운전자의 안전한 도로운행을 지원하게 된다. 따라서 노변방송은 대부분의 국민들에게 편리하게 사용할 수 있는 대국민 교통정보서비스 구축으로 안전지향형 도로관리체계에 일조할 것이다.