• Proceedings of the Korea Water Resources Association Conference
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• 2021.06a
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• pp.343-343
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• 2021

최근 국내외적으로 발생되는 대규모의 가뭄에 대하여 여러 과학자들은 자연적인 현상의 가뭄이 아니라 인간의 영향으로 변형된 유역 상황으로 증발산과 토양수분량 그리고 하천유량 등이 자연적인 상태와 다르게 변화되면서 지속된 가뭄으로 평가하고 있다. 우리나라는 대부분의 지역에서 댐과 저류지를 중심으로 수자원 관리가 이루어지고 있으며, 자연적인 수문과정에 의한 유출에 따른 수문학적 가뭄과는 차이가 존재한다. 사회경제적 인자(인구밀도, 농업 및 산업 경제규모 등)는 댐 및 저수지의 용수사용에 큰 영향을 미치며, 저류지의 저류량을 활용하여 판단한 인위적 용수사용이 고려된 수문학적 가뭄(인위적 수문학적 가뭄)과 자연 상태로의 수문학적 가뭄의 특성은 크게 다를 수 있다. 하지만, 사회경제적 인자들이 수문학적 가뭄에 미치는 영향에 대하여 비교한 연구는 상관성 분석을 토대로한 연구가 대부분이다. 본 연구에서는 인자들이 인위적 수문학적 가뭄에 미치는 정도를 정량적으로 비교하기 위하여 베이지안 네크워크 모형을 활용하여 사회경제적 인자와 인위적 수문학적 가뭄과의 관계를 분석하였다. 해당 관계를 바탕으로 코플라 함수를 활용함으로써 베이지안 네트워크 내의 결합확률을 산정하였다. 다양한 사회경제적 인자들에 중에서 인과지도를 바탕으로 활용 가능한 인자로 농업용수 사용량, 생공용수 사용량 자료를 구축하였으며, 기상학적 가뭄지수를 추가적으로 고려하여 한강유역 충주댐 유역에 적용하였다. 그 결과 기상학적 가뭄과 농업용수 사용량과 생공용수 사용량은 값이 증가함에 따라 인위적 수문학적 가뭄의 발생확률이 증가하였다. 사회경제적 인자 중에서는 생공용수 사용량(0.39~0.49)이 전반적으로 농업용수 사용량(0.36~0.48)보다 인위적 수문학적 가뭄에 보다 큰 영향을 미치고 있으며, 값이 적을수록 생공용수 사용량의 영향이 보다 더 크다는 것이 확인되었다. 이를 바탕으로 인위적 수문학적 가뭄의 대응을 위해서는 농업용수 사용량보다 생공용수 사용량의 감축이 우선적으로 이루어져야 그 효과가 클 것으로 판단된다. 본 연구에서 제시한 모형은 베이지안 네트워크를 기반으로 하므로, 둘 이상의 인자에 대하여 복합적으로 가뭄에 영향을 미치는 영향에 대한 추가적인 연구가 가능하다.

• Convergence Security Journal
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• v.3 no.2
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• pp.85-97
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• 2003

At the end of last January, 2003, a domestic top-level domain name server (DNS) shut down the server and it caused the wired and wireless internet services to be completely paralyzed in the aftermath of a virus attack incurring a various range of losses nationwide. The main reason of this event is the lack of our awareness of cyber security. In particular, in the small-scale network, there are few security administrators and no operating devices to protect information as well. Under this circumstance, using ESM center to service real-time security supervision and correspondence for network, it can be one option. However, due to the economic efficiency, most of security systems have been being developed focusing on the large-scale network first. Therefore, ESM centers which inspect security state of network concentrate on IDC or large-scale network services. This dissertation studies economical ESM service by designing exclusive SnSA for small-scale network for widespread use. Firstly, network invasion feeler function N_SnSA and host invasion feeler function H_SnSA are embodied to collect more informations in the small-scale network. Secondarily, the existing vulnerability is studied to find the solutions linked with a low cost to a Public center such as Kyonggi Univ ESM center.

• Convergence Security Journal
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• v.16 no.2
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• pp.19-23
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• 2016

The design, management, and operation of network infrastructure have evolved during the last few years, leveraging on innovative technologies and architectures. With such a huge trend, due to the flexibility and significant economic potential of these technologies, software defined networking (SDN) and network functions virtualization (NFV) are emerging as the most critical key enablers. SDN/NFV enhancing the infrastructure agility, thus network operators and service providers are able to program their own network functions (e.g., gateways, routers, load balancers) on vendor independent hardware substrate. They facilitating the design, delivery and operation of network services in a dynamic and scalable manner. In NFV, the management and orchestration (MANO) orchestrates other specific managers such as the virtual infrastructure manager (VIM) and the VNF Manager (VNFM). In this paper, we examine the contents of these NFV MANO systematically and proposes a security system in a virtualized environment.

• The Journal of the Korea Contents Association
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• v.16 no.6
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• pp.671-679
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• 2016

We investigated subgroups within a global communication network to improve the empirical understanding of global communication phenomenon from the social network perspective. We collected global communication data from Twitter and constructed a global communication network. We also added countries' geographic and economic properties used in the United Nations and the World Economic Forum. We analyzed the subgroups' structure within the global communication network using centrality analysis, core-peripheral analysis, and cohesion analysis. We also detected communities embedded within the global communication network with modularity-based community detection methods. We found that the core countries occupy central positions in the global communication network and there is a hierarchical communication structure among the economic subgroups. Futhermore, we discovered some communities within the global communication network and found that countries within the communities can have homophily such as economy, geography, history, culture, and religion.

• Proceedings of the Korea Multimedia Society Conference
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• 2004.05a
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• pp.82-85
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• 2004

휴대 단말기 보유율의 급격한 증가는 새롭고 다양한 형태의 무선 통신 기술의 개발을 촉진시키는 계기가 되었으며, 특히 국내의 경우 이동통신 시장의 경제적이나 양적으로 급속한 성장을 이루어 사회 전반에 걸쳐서 새로운 가치를 생산해 내어 생활 모습을 크게 바꾸어 놓고 있다. 따라서 이러한 환경의 변화는 사용자 중심의 다양한 서비스를 제공할 수 있는 차세대 무선 통신 기술의 연구가 필수적으료 요구된다. 본 논문에서는 RF Tag 기반의 안전한 네트워크 방식을 제안하고자 한다. 제안된 방식은 안전한 네트워크를 형성한 뒤 불법적 Tag에 대한 보안 서비스와 다양한 서비스를 제공한다.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.36 no.12B
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• pp.1481-1488
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• 2011

Recently, Hacking Attacks are appearing as a various Attack techniques with evolution of the Network. and most of the network through a Various Security Systems are responding to an attack. In addition, it should be placed adding the Security Systems to protect the Internal Network's Information assets from External attacks. But, The use of Security Systems inside the network makes a significant impact on Security and Performance, as well as a result causes Economic Additional Costs. Therefore, In this paper, it will be to analyze by associated a case study and experimental results about the Additional Costs Factors(Variable situations difficult to predict and Information Security Recognition levels, Security Systems, Information Asset Assessment). This is expected to serve as a valuable Information for the Reduction of an Costs in a Network deployment and Design in a future.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.39 no.3
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• pp.132-139
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• 2002

The implementation of passive optical network in the access network will result in design of the network that have characteristics of broadband, long distance transmission, transparency. Particularly, optical technologies of WDM and WGR have made a new access network of WDM-PON. This paper proposes the algorithm that determines structural elements of a survivable optical access network, and simulates the cost of various scheme of proposed network architectures. Our results show that multistage star is the most cost effective scheme than the other architectures and show that network architecture designed by proposed algorithm provides survivability with single link and 1st node failure.

• Journal of Navigation and Port Research
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• v.32 no.1
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• pp.65-72
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• 2008

This study is aimed to contribute in establishing new port policy by research and analysis in design of global port logistics network in the East Asia region. In order to build such port logistics network, 21 ports located in East Asia among the world's 50th largest ports were selected in this study. Furthermore, the amount of container cargo and the ports of call were analyzed to categorize the subject ports in East Asia. Finally, this study tries to find economic network between the base port in East Asia, EU or North America and feeder ports in terms of logistics cost. As a result, Singapore, Hong Kong, Shanghai, and Busan ports were found as the representative ports in the East Asia that may connect North America and Europe with the minimum logistics expenses. Therefore, to maintain the stable cargo volume in ports, Korea should promote not only the overseas terminal operation which links to the Singapore, Hong Kong, and Shanghai ports, but also establish the global port logistic network connecting the Busan port.

• Journal of the Institute of Electronics and Information Engineers
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• v.51 no.6
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• pp.169-174
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• 2014

Practical deployment methods for sensor nodes are demanding as applications using sensor nodes increase. In particular, node connectivity is crucial not only for the network longevity but also for direct impacts on sensing and data collection capability. Economic requirement at building sensor networks and often limited access for sensor fields due to hostile environment force to remain at random deployment from air. However, random deployment often result in lost connection problem and inefficient network topology issue due to node irregularity. In this paper, mixed deployment of key nodes that have better communication capability is proposed to support the original deployment into working in an efficient way. Node irregularity is improved by introducing mixed nodes and an efficient mixed node density is also analyzed. Simulation results show that the mixed deployment method has better performance than the existing deployment methods.

• Korean Journal of Construction Engineering and Management
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• v.5 no.3 s.19
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• pp.120-127
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• 2004

In May 2004, Poland with nine other Eastern European countries joined the European Union(EU). After accession to the EU, Poland will accelerate the realization of investment in road sector, and wants to achieve important development of its road network condition in year 2005. Polish government is not able to afford the whole investment needed for construction of its motorways, so it wants to develop effective techniques of project funding based on the Public Private Partnerships(PPP). Without having high-performance transport networks, one country's economy cannot be competitive. It was the reason for establishing the Trans European Network(TEN) in the European Union. It creates the links, which are still missing between the fifteen countries of Western Europe and the new member countries like Poland. Consequently, Poland will also need to establish a proper transport infrastructure network. This paper will discuss how the PPP scheme can be applied for the transport infrastructure development in Poland as a EU member.