• Journal of Positioning, Navigation, and Timing
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• 제12권3호
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• pp.307-314
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• 2023

Wide-Area Differential Global Positioning System (WADGPS) is a system that operates a number of reference stations to provide correction information to improve the accuracy of GPS users, and it is available to service users within the area where the wide-area reference stations are installed. Recently, as positioning information has been used in various applications, the need for WADGPS for precise navigation in long-distance spaced areas where the wide-area reference stations cannot be installed has been raised. This paper tested the user navigation performance outside the wide-area reference stations of the WADGPS system, which serves both GPS Precise Positioning Service (PPS) and Standard Positioning Service (SPS) users. Static and dynamic tests were conducted using vehicles, and as a result, position accuracy improvement through WADGPS was confirmed even at points hundreds of kilometers outside the network area of the wide-area reference stations. Through this, the performance of the PPS/SPS correction system and the possibility of expanding the service area were confirmed.

• 환경영향평가
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• 제11권4호
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• pp.289-309
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• 2002

Solutions of many landscape problems depend on area-wide assessment and interpretation of spatial and physical characteristics over the study area. The authors argue that the public awareness for an area-wide urban landscape appears to be very low due to limited chance to the information. Acknowledging these constraints, an operational, user-friendly information system has been developed by combining internet technology with GIS. In particular, integration among satellite data and digital maps takes advantage of each component, and enables the landscape structure to be visualized, interacted with and deployed all on the Web. The 1m resolution IKONOS data realistically identified the major type of landscape by large scale spatial precision while TM data revealed successfully the major parameters that influence an area-wide spatial structure in the study area. This system would play a crucial role in improving the public awareness for area-wide landscape information if it is operationally introduced into the Government since the highly user-friendly interface based on image maps provides a completely new means for disseminating information for area-wide landscape in a visual and interactive manner to the general public.

• 대한원격탐사학회지
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• 제17권3호
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• pp.189-197
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• 2001

원격탐사의 장점 중 하나는 넓은 지역의 정보를 신속하게 추출할 수 있다는 것이다. 이러한 장점은 광역지대의 토지피복을 분류하여 자원 및 환경을 신속하게 파악하고자 하는 수요에 부응할 수 있는 효과적인 수단이다. 이 연구에서는 다량의 위성영상을 이용하여 넓은 지역의 토지피복분류를 효율적으로 수행하는 방법을 제안하였다. 이를 위해 한반도를 대상으로 Landsat TM 및 ETM+ 위성영상 23 scene을 이용하여 공간해상도 100m인 토지피복분류를 수행하였다. 기존의 정형화된 위성영상처리 및 분류기법을 적용하여 다량의 위성영상을 처리하고 광역 토지피복분류를 효율적으로 수행하였다. 이러한 방법은 국토계획이나 광역 지역계획 등에서 필요한 전반적인 자원현황을 신속하고 효과적으로 제공할 수 있는 수단이 될 것으로 판단된다.

• 대한전자공학회논문지SD
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• 제39권6호
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• pp.19-25
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• 2002

규칙적인 가상 연결방법을 이용하면 노드에서 라우팅을 위한 프로세싱 시간이 단축되어 고속의 네트워크에 적용이 가능하다. 규칙적인 가상 연결방법의 하나인 셔플넷은 일반적으로 p개의 연결이 다른 노드들과 이루어진다. 그러나 우리가 제안한 하나 걸른 행과 연결된 이중층 셔플넷 토폴로지를 이용하면 2p개의 노드들과 동시에 연결되므로 더욱 효과적인 광역 통신망에 적용할 수 있다. 이 하나 걸른 행과 연결된 이중층 셔플넷 토폴로지를 이용하여 물리적 토폴로지에 가상 토폴로지를 imbedding하는 방법을 본 논문에서 연구하였다. 전체 지연 시간을 최소화하는 것을 목표로 네트워크를 최적화하였다.

• 디지털융복합연구
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• 제5권2호
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• pp.59-70
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• 2007

Recently, rising of the convergence of technologies such as IT, GIS, GPS, and Sensors is developing the new information environment which enables man-to-man, man-to-object and object-to-object to exchange information anywhere and anytime. The Korean government has made great efforts to implement the virtual government with development of the next generation technologies continually and dynamically. These efforts for implementing e-government can be summarized by the citizen centered, integrated services, the customized personalization, the intellectual services, and the integration and cooperation between each offices for providing those services. Therefore, we wish to present the model of wide-area intelligent information systems which can provide services to form the future of this virtual government with GIS infrastructure in this study.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2008년도 제39회 하계학술대회
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• pp.273-274
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• 2008

Recently, the most wide-area blackout in North America, Canada and Europe had shown us indirectly the importance of Wide-Area Power System Protection and had influence on the direction of domestic electric power industry. After reorganization of the electric power industry in 2001, market incentives controls the power generation, transmission and distribution rather than stability of power grid, and moreover it produce bad results like inefficient facility management and too much competition. In addition, we can easily predict the massive loss of social and economic when the wide-area outage occurs by north direction load flow which is a pending problems of domestic power system and in a changed industry likes hi-tech manufacture and information technology industries. This paper introduces the development of infra systems for prevent wide-area blackout in situations of the power system operations.

• 전기학회논문지
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• 제60권7호
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• pp.1347-1353
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• 2011

While most of the existing protection schemes have been designed with local information around individual components, these local schemes are not considered capable of protecting the modern electric power gird with growing complexity. Recent blackouts in North America and Europe have renewed the emphasis on coordinated protection and control actions to avoid systemwide blackouts, utilizing all of the available grid information. Thus, this paper proposes a new methodology, Agent-based Colored Petri Net (ACPN) modeling for systematically representing, modeling and analyzing information flows and interactions among the entities of the electric power grid. The paper demonstrates its efficacy and accuracy by investigating an ACPN model of a wide area protection system for a typical power grid. The proposed modeling and analysis schemes may further provide a framework to help assure reliability and interoperability of diverse smart grid components.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2011년도 제42회 하계학술대회
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• pp.178-179
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• 2011

The exchange of information with legacy systems is a main issue in the era of SMARTGRID. Because WAMAC(Wide Area Monitoring and Control) system has monitoring function, as well as control function, it is very necessary for WAMAC to exchange data and information with SCADA(Supervisory Control and Data Acquisition) / EMS(Energy Management System). IEC 61970 CIM(Common Information Model) is an abstract model that represents all the major objects in an electric utility enterprise typically involved in utility operations. In this paper, a proposal that adopting CIM to WAMAC model be submitted so that the integration of various legacy system and application for itself be able to be flexible.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제10권5호
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• pp.2267-2285
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• 2016

Information Centric Networking that uses content name instead of IP address as routing identifier can handle challenges such as traffic explosion and user mobility, but it also suffers from scalability and incompatibility problems. In this paper by combining the concept of software defined networking and Internet end to end arguments, we propose a wide area deployable software defined information centric networking service model named SD-ICN. SD-ICN employs a dual space structure that separates edge service network and core transmission network. The enhanced SDN techniques are used in edge service network in order to implement intelligent data routing and caching, while traditional IP technique is reserved in core transmission network so as to provide wide area high speed data transmission. Besides, a distributed name resolution system based on the cooperation of different controllers is also presented. The prototype experiments in our campus network show that SD-ICN can be deployed in a scalable and incremental way with no modification of the core network, and can support typical communication modes such as multicast, mobility, multihoming, load balancing, and multipath data transmission effectively.