• 방송공학회논문지
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• 제13권1호
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• pp.92-98
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• 2008

네트워크 데이터 모델링은 침입 탐지 시스템의 성능 평가, 네트워크 모니터링, 네트워크 데이터 분석 기법 연구에 있어서 반드시 필요한 연구이다. 네트워크 데이터의 모델링에는 반드시 네트워크의 실제 데이터를 분석하고, 분석된 데이터를 이용하여 효과적으로 데이터를 구성하여야만, 실제 네트워크 데이터의 충분한 정보를 모델링 된 데이터에 반영할 수 있다. 본 연구에서는 대규모의 네트워크 데이터에서 실제 네트워크에서 사용 가능한 모든 성분에 대해 수량화하였으며, 수량화 된 데이터를 통계적 분석방법을 통하여 모델링 데이터에서 가장 효과적인 분류 기준으로 작용할 수 있는 성분을 분석하였다.

• 한국방송∙미디어공학회:학술대회논문집
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• 한국방송공학회 1996년도 Proceedings International Workshop on New Video Media Technology
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• pp.1-6
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• 1996

To promote academic researches on earth environment utilizing satellite data, research infrastructure such as satellite data reception processing, distribution and archival systems should be fully provided. The means to enhance the infrastructure were discussed by a working group and“Satellite Data Center via Network”has been proposed. This concept has three principles; (1) To realize necessary functions by organizing experts distributed all over Japan and connecting them by network, (2) To realize“Satellite Data Center via Network”for GMS and NOAA Satellites, which are widely used for research, and (3) Satellite data set oriented to specific research area should be generated by researchers having definite research purposes of sensor algorithms and hugh volume data processing. Utilization of the Science Information Network (SINET) has been discussed to realize this concept, and to accelerate this project an experiment“Network Utilization for Wide Area Use of Satellite Image Data”under“Cooperative Experiment on Multimedia Communication”has been introduced. And the roles of the Institute of Industrial Science, University of Tokyo to contribute this project has been described.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제11권11호
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• pp.5243-5263
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• 2017

Data center networks provide critical bandwidth for the continuous growth of cloud computing, multimedia storage, data analysis and other businesses. The problem of low link bandwidth utilization in data center network is gradually addressed in more hot fields. However, the current scheduling strategies applied in data center network do not adapt to the real-time dynamic change of the traffic in the network. Thus, they fail to distribute resources due to the lack of intelligent management. In this paper, we present an improved adaptive traffic scheduling strategy utilizing the simulated annealing genetic algorithm (SAGA). Inspired by the idea of software defined network, when a flow arrives, our strategy changes the bandwidth demand dynamically to filter out the flow. Then, SAGA distributes the path for the flow by considering the scheduling of the different pods as well as the same pod. It is implemented through software defined network technology. Simulation results show that the bisection bandwidth of our strategy is higher than state-of-the-art mechanisms.

• 한국정보통신설비학회:학술대회논문집
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• 한국정보통신설비학회 2006년도 하계학술대회
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• pp.39-42
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• 2006

There are various analysis functions(including prediction of path loss, analyzing of capacity and coverage, etc.) of simulation tool to design and optimize the mobile communication network. Its reliability absolutely effects the performance of mobile communication network. Especially as the wireless network highly advancing focused on data service, it more needs to research and develop on the standard establishment of reliability of the simulation tool. Also it is important the systematic research how to improve the reliability of simulation tool. In this paper, to give the concrete process and skill about how to improve reliability, we define the kinds of reliability at first. And then we explain the comparison results between real field measurement data and theoretic simulation data.

• KNOM Review
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• 제22권2호
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• pp.39-47
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• 2019

과학기술연구망(KREONET)에서는 기상기후 정보, 고에너지물리, 천문연구, 위성정보데이터, 유전체 연구데이터 등의 빅데이터 중심 첨단 연구 활동을 지원을 수행하고 있다. 기존의 네트워크 보안장비들이 있는 환경에서는 성능 저하가 발생하기 때문에, 고성능 연구전용 네트워크 상에서 성능저하를 방지하고, 고속 연구협업을 위한 방안들이 연구되고 있다. 또한 최근 이슈가 되는 양자컴퓨터의 등장으로 기존 암호체계를 활용한 보안성에 위협이 되고 있다. 본 논문에서는 단대단(End-to-End)의 고속 연구전용 네트워크상에서 양자암호기반의 통신망 구축을 통하여 물리적 보안성을 강화시키는 환경구축과 고성능 전송테스트를 통하여 양자암호기반 통신망을 구성한다. 물리적 암호화 수행시에 망 성능에 미치는 영향을 분석하여, 고성능 연구협업 네트워크 구축을 위한 기초 자료로 활용하고자 한다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제11권2호
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• pp.1250-1264
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• 2017

This paper presents the architecture design, implement, experimental validation of a bistatic backscatter wireless communication system in Wi-Fi network. The operating principle is to communicate a tag's data by detecting the power level of the power modulated Wi-Fi packets to be reflected or absorbed by backscatter tag, in interconnecting with Wi-Fi device and Wi-Fi AP. This system is able to provide the identification and sensor data of tag on the internet connectivity without requiring extra device for reading data, because this uses an existing Wi-Fi AP infrastructure. The backscatter tag consists of Wi-Fi energy harvesting part and a backscatter transmitter/a power-detecting receiver part. This tag can operate by harvesting and generating energy from Wi-Fi signal power. Wi-Fi device decodes information of the tag data by recognizing the power level of the backscattered Wi-Fi packets. Wi-Fi device receives the backscattered Wi-Fi packets and generates the tag's data pattern in the time-series of channel state information (CSI) values. We believe that this system can be achieved wireless connectivity for ultra- low-power IoT and wearable device.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제11권3호
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• pp.1510-1532
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• 2017

In smart grid, privacy implications to individuals and their families are an important issue because of the fine-grained usage data collection. Wireless communications are utilized by many utility companies to obtain information. Network coding is exploited in smart grids, to enhance network performance in terms of throughput, delay, robustness, and energy consumption. However, random linear network coding introduces a new challenge for privacy preserving due to the encoding of data and updating of coefficients in forwarder nodes. We propose a distributed privacy preserving scheme for random linear network coding in smart grid that considers the converged flows character of the smart grid and exploits a homomorphic encryption function to decrease the complexities in the forwarder node. It offers a data confidentiality privacy preserving feature, which can efficiently thwart traffic analysis. The data of the packet is encrypted and the tag of the packet is encrypted by a homomorphic encryption function. The forwarder node random linearly codes the encrypted data and directly processes the cryptotext tags based on the homomorphism feature. Extensive security analysis and performance evaluations demonstrate the validity and efficiency of the proposed scheme.

• 대한전자공학회논문지
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• 제22권6호
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• pp.103-113
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• 1985

본 론문은 packet 교환 방식의 computer 통신망인 KORNET 개발에 판한 4편의 논문중 제1부로서 KORNET의 전체적인 개요와 network management center(NMC)의 개발에 관하여 기술하였다. NMC는 operator dialogue를 통하여 network내 여러 소자의 상태를 감지 하고 가입자와 network의 운용을 담당하며 routing의 관리를 담당하는등 network의 중추적 기능을 구행한다 본 KORNET의 구현에 있어서 통신 protocol은 CCITT의 권고사항을 충실히 따랐으며 NMC의 응용 software인 operator interface, prinary/secondary부, session layer차 packet level adaptor는 자체적으로 개발하였고, packet, link 및 physical level protocol은 Data Goner각사에서 개발한 XODIAC X.25를 응용하여 개발하였다.

• 한국조리학회지
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• 제23권3호
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• pp.257-270
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• 2017

The purpose of this study was to visualize the semantic network with big data related to food exhibition at convention center. For this, this study collected data containing 'coex food exhibition/bexco food exhibition' keywords from web pages and news on Google during one year from January 1 to December 31, 2016. Data were collected by using TEXTOM, a data collecting and processing program. From those data, degree centrality, closeness centrality, betweenness centrality and eigenvector centrality were analyzed by utilizing packaged NetDraw along with UCINET 6. The result showed that the web visibility of hospitality and destinations was high. In addition, the web visibility was also high for convention center programs, such as festival, exhibition, k-pop and event; hospitality related words, such as tourists, service, hotel, cruise, cuisine, travel. Convergence of iterated correlations showed 4 clustered named "Coex", "Bexco", "Nations" and "Hospitality". It is expected that this diagnosis on food exhibition at convention center according to changes in domestic environment by using these web information will be a foundation of baseline data useful for establishing convention marketing strategies.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제13권3호
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• pp.1164-1183
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• 2019

The rapid development of cloud computing and high requirements of operators requires strong support from the underlying Data Center Networks. Therefore, the effectiveness of using resources in the data center networks becomes a point of concern for operators and material for research. In this paper, we discuss the online virtual-cluster provision problem for multiple tenants with an aim to decide when and where the virtual cluster should be placed in a data center network. Our objective is maximizing the total revenue for the data center networks under the constraints. In order to solve this problem, this paper divides it into two parts: online multi-tenancy scheduling and virtual cluster placement. The first part aims to determine the scheduling orders for the multiple tenants, and the second part aims to determine the locations of virtual machines. We first approach the problem by using the variational inequality model and discuss the existence of the optimal solution. After that, we prove that provisioning virtual clusters for a multi-tenant data center network that maximizes revenue is NP-hard. Due to the complexity of this problem, an efficient heuristic algorithm OMS (Online Multi-tenancy Scheduling) is proposed to solve the online multi-tenancy scheduling problem. We further explore the virtual cluster placement problem based on the OMS and propose a novel algorithm during the virtual machine placement. We evaluate our algorithms through a series of simulations, and the simulations results demonstrate that OMS can significantly increase the efficiency and total revenue for the data centers.