• 한국멀티미디어학회논문지
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• 제11권12호
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• pp.1706-1715
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• 2008

In a super-peer based P2P network, the network is clustered and each cluster is managed by a special peer, which is called a super-peer. A Super-peer has information of all the peers in its cluster. This type of clustered P2P model is known to have efficient information search and less traffic load than unclustered P2P model. In this paper, we compute the message traffic cost incurred by peers' query, join and update actions within a cluster as well as between the clusters. With these values, we estimate the optimal number of super-peers that minimizes the traffic cost for the various size of super-peer based P2P networks.

• 한국전자통신학회논문지
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• 제5권2호
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• pp.185-192
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• 2010

P2P 기술은 분산 환경에서 자원을 보유한 개인은 효율적으로 공유하는 측면에서 활용도 높은 분야이다. P2P 시스템은 자원 검색, 전송 재전송 작업이 발생됨으로 인해 네트워크 트래픽이 과다하게 발생된다. 이에 관한 성능 향상을 목표로 많은 연구가 진행되고 있다. 이러한 성능 향상의 다양한 방향성 가운데 사용자 입장에서의 사용성 개선 측면이 최근 중요한 부분으로 대두되고 있다. 이에 본 연구에서는 사용성 개선을 위한 P2P 그룹 검색 알고리즘을 제안한다.

• 한국경영과학회지
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• 제30권1호
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• pp.1-15
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• 2005

In this paper, we deal with a mesh network design problem arising from the deployment of WDM for the optical internet. The mesh network consists of mesh topology for satisfying traffic demand while minimizing the cost of WDM, OXC, and fiber cables. The problem seeks to find an optimal routing of traffic demands in the network such that the total cost is minimized. We formulate the problem as a mixed-integer programming model and devise a tabu search heuristic procedure. Also we develop an optical internet design system that implements the proposed tabu search heuristic procedure. We demonstrate the computational efficacy of the proposed algorithm, compared with CPLEX 8.0.

• 정보기술과데이타베이스저널
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• 제7권1호
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• pp.42-53
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• 2000

The major goal of this research is to develop an optimal route search algorithm for an intelligent route guidance system, one sub-area of ITS. ITS stands for intelligent Transportation System. ITS offers a fundamental solution to various issues concerning transportation and it will eventually help comfortable and swift moves of drivers by receiving and transmitting information on humans, roads and automobiles. Genetic algorithm, and fuzzy logic are utilized in order to implement the proposed algorithm. Using genetic algorithm, the proposed algorithm searches shortest routes in terms of travel time in consideration of stochastic traffic volume, diverse turn constraints, etc. Then using fuzzy logic, it selects driver-preference optimal route among the candidate routes searched by GA, taking into account various driver's preferences such as difficulty degree of driving and surrounding scenery of road, etc. In order to evaluate this algorithm, a virtual road-traffic network DB with various road attributes is simulated, where the suggested algorithm promptly produces the best route for a driver with reference to his or her preferences.

• 한국컴퓨터정보학회논문지
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• 제24권7호
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• pp.9-17
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• 2019

As the artificial intelligence technology has developed recently, researches on chatbots that provide information and contents desired by users through an interactive interface have become active. Since chatbots require a variety of natural language processing technology and domain knowledge including typos and slang, it is currently limited to develop chatbots that can carry on daily conversations in a general-purpose domain. In this study, we propose an artificial intelligence chatbot that can provide real-time public traffic information and route information. The proposed chatbot has an advantage that it can understand the intention and requirements of the user through the conversation on the messenger platform without map application.

• International journal of advanced smart convergence
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• 제10권3호
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• pp.72-80
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• 2021

Metaverse is an immersive 3D virtual environment, a true virtual artificial community in which avatars act as the user's alter ego and interact with each other. If we do not manage the hype for the metaverse, which has recently been receiving a surge in interest, the metaverse will fail to cross the chasm. In this study, to provide stakeholders with insights for the successful introduction and growth of the 3D immersive next-generation virtual world, metaverse, we analyzed user-side interest, media-side interest, and research-side interest. For this purpose, in this study, search traffic, news frequency and topic, and research article frequency and topic were analyzed. The methodology and results of this study are expected to provide insight for the stable success of metaverse transformation and the coexistence of the real world and the virtual world through hyper-connection and hyper-convergence.

• 한국ITS학회 논문지
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• 제16권1호
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• pp.78-89
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• 2017

기존 경로 탐색 알고리즘은 최단거리, 최단시간 등 교통지표를 계수로 활용한 최단경로탐색 알고리즘에 국한되어 있다. 본 연구에서는 이용자 선호도에 따른 안전, 환경 비용을 추가한 대중교통 경로 탐색 알고리즘을 도출하였다. 알고리즘 적용 및 평가 방안으로 Macro Simulation인 VISUM으로 분석을 시행하였다. 안전, 환경 저항값에 따라 버스보다 지하철을 이용한 경로를 더 선호하였으며, 우회하더라도 안전하고 환경적인 경로를 선택하는 것으로 분석되었다. 본 연구는 안전, 환경을 고려한 타 경로탐색 알고리즘 검증 시 활용이 가능하며, 향후 스마트폰 Application에 이용자 선호에 따른 경로탐색 알고리즘을 도입할 시 안전, 환경에 대한 경로를 선택하여 이용자들에게 매우 유용한 정보를 제공할 수 있으며, 이를 통해 이용자 친화적인 측면의 정보제공 질 향상을 도모할 수 있다.

• Journal of Communications and Networks
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• 제15권5호
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• pp.514-526
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• 2013

With a long sensing period, the inter-frame spectrum sensing in IEEE 802.22 standard is vulnerable to the effect of the traffic of the primary user (PU). In this article, we address the two degrading factors that affect the inter-frame sensing performance with respect to the random arrival/leaving of the PU traffic. They are the noise-only samples under the random arrival traffic, and the PU-signal-contained samples under the random leaving traffic. We propose the model in which the intra-frame sensing cooperates with the inter-frame one, and the inter-frame sensing uses the time-of-arrival (ToA), and time-of-leave (ToL) detectors to reduce the two degrading factors in the inter-frame sensing time. These ToA and ToL detectors are used to search for the sample which contains either the ToA or ToL of the PU traffic, respectively, which allows the partial cancelation of the unnecessary samples. At the final stage, the remaining samples are input into a primary user detector, which is based on the energy detection scheme, to determine the status of PU traffic in the inter-frame sensing time. The analysis and the simulation results show that the proposed scheme enhances the spectrum-sensing performance compared to the conventional counter-part.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2003년도 하계종합학술대회 논문집 Ⅲ
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• pp.1299-1302
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• 2003

In this paper, we propose new method which can provide user the path to the target place efficiently. It stores the state of roads to target place as the form of Q-table and finds the proper path using Q-table.0-table is updated by the information about real traffic which is reported by users. This method can provides the proper path, using less storage and less computation time than the conventional method which stores entire road traffic information and finds the path by graph search algorithm.

• 경영과학
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• 제23권2호
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• pp.161-174
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• 2006

In this paper, we consider a network optimization problem arising from the deployment of BcN access network. BcN convergence services requires that access networks satisfy QoS meausres. BcN services have two types of traffics : stream traffic and elastic traffic. Stream traffic uses blocking probability as a QoS measure, while elastic traffic uses delay factor as a QoS measure. Incorporating the QoS requirements, we formulate the problem as a nonlinear mixed-integer Programming model. The Proposed model seeks to find a minimum cost dimensioning solution, while satisfying the QoS requirement. We propose two local search heuristic algorithms for solving the problem, and develop a network design system that implements the developed heuristic algorithms. We demonstrate the computational efficacy of the proposed algorithm by solving a realistic network design problem.