• 한국경영과학회:학술대회논문집
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• 한국경영과학회 2005년도 추계학술대회 및 정기총회
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• pp.189-206
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• 2005

Much of work on network externality assumed network effects are dependent on the network size. Therefore, very little consideration is given to the view that marginal benefits from joining the network may not increase with the network size if consumer benefits come from the direct interaction with neighbors, namely local network. In this study, we used the agent-based simulation method to reexamine the effectiveness of the traditional network market strategy under the presence of the local network where two incompatible technologies compete. We found that the strategy of growing an initial customer base is not effective under the presence of the local network. Our study also showed that targeting customers based on their technology Preference is not as effective as targeting customers within the same local network. As a result, the focus of a network market strategy should be directed to taking advantage of the customer network.

• KNOM Review
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• 제21권2호
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• pp.1-9
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• 2018

네트워크 가상화 (Network virtualization)는 물리 네트워크상에서 각 사용자 별로 독립된 가상의 네트워크 환경을 생성하는 기술을 지칭한다. 네트워크 가상화 기술은 물리 네트워크 자원을 공유하여 사용자 별로 네트워크를 구축하는 데 필요한 비용을 절감할 수 있으며, 네트워크 관리자가 요구사항에 따라 동적으로 네트워크를 관리할 수 있도록 돕는다. 하지만 동적으로 네트워크 관리를 수행할 수 있다는 장점에도 불구하고, 관리자가 여전히 직접 판단을 내리고 관리 기능을 실행하는 과정은 동일하다. 네트워크 관리 기능 실행 전까지 관리자에 의해 네트워크 상황을 파악하고 결정을 내리는 과정에는 많은 시간이 소요될 수 있기 때문에 네트워크 가상화로 얻을 수 있는 동적 네트워크 관리라는 장점을 최대화 하지 못하고 있다. 본 논문에서는 기계학습 (Machine Learning) 기술을 도입하여 사람의 도움 없이 네트워크가 스스로 학습하여 동적으로 네트워크 관리를 수행하는 방법을 제안한다. 제안하는 방법은 가상 네트워크 관리에서 핵심적이고 필수적인 문제인 자원관리 최적화 문제를 서비스 펑션 체인(Service Function Chaining) 문제로 정의하고, VNF의 자원 수요를 예측하여 적절한 자원을 동적으로 할당해 서비스 중단이 일어나는 것을 방지하면서 네트워크 운용비용을 절감하는 것을 목표로 한다.

• International Journal of Computer Science & Network Security
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• 제22권9호
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• pp.23-30
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• 2022

Glaucoma is a chronic neuropathy that affects the optic nerve which can lead to blindness. The detection and prediction of glaucoma become possible using deep neural networks. However, the detection performance relies on the availability of a large number of data. Therefore, we propose different frameworks, including a hybrid of a generative adversarial network and a convolutional neural network to automate and increase the performance of glaucoma detection. The proposed frameworks are evaluated using five public glaucoma datasets. The framework which uses a Deconvolutional Generative Adversarial Network (DCGAN) and a DenseNet pre-trained model achieves 99.6%, 99.08%, 99.4%, 98.69%, and 92.95% of classification accuracy on RIMONE, Drishti-GS, ACRIMA, ORIGA-light, and HRF datasets respectively. Based on the experimental results and evaluation, the proposed framework closely competes with the state-of-the-art methods using the five public glaucoma datasets without requiring any manually preprocessing step.

• 한국우주과학회:학술대회논문집(한국우주과학회보)
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• 한국우주과학회 2009년도 한국우주과학회보 제18권1호
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• pp.56.2-56.2
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• 2009

• Journal of information and communication convergence engineering
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• 제7권2호
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• pp.157-163
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• 2009

With the wide usage of internet in many fields, networks are being exposed to many security threats, such as DDoS attack and worm/virus. For enterprise network, prevention failure of network security causes the revealing of commercial information or interruption of network services. In this paper, we propose a method of prevention of DDoS attacks for enterprise network based on traceback and network traffic analysis. The model of traceback implements the detection of IP spoofing attacks by the cooperation of trusted adjacent host, and the method of network traffic analysis implements the detection of DDoS attacks by analyzing the traffic characteristic. Moreover, we present the result of the experiments, and compare the method with other methods. The result demonstrates that the method can effectively detect and block DDoS attacks and IP spoofing attacks.

• International Journal of Computer Science & Network Security
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• 제23권7호
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• pp.219-230
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• 2023

Wireless Body Area Networks (WBANs) have made it easier for healthcare workers and patients to monitor patients' status continuously in real time. WBANs have complex and diverse network structures; thus, management and control can be challenging. Therefore, considering emerging Software-defined networks (SDN) with WBANs is a promising technology since SDN implements a new network management and design approach. The SDN concept is used in this study to create more adaptable and dynamic network architectures for WBANs. The study focuses on comparing the performance of two SDN controllers, POX and Ryu, using Mininet, an open-source simulation tool, to construct network topologies. The performance of the controllers is evaluated based on bandwidth, throughput, and round-trip time metrics for networks using an OpenFlow switch with sixteen nodes and a controller for each topology. The study finds that the choice of network controller can significantly impact network performance and suggests that monitoring network performance indicators is crucial for optimizing network performance. The project provides valuable insights into the performance of SDN-based WBANs using POX and Ryu controllers and highlights the importance of selecting the appropriate network controller for a given network architecture.

• Journal of Information Processing Systems
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• 제17권4호
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• pp.801-817
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• 2021

Network virtualization technologies have played efficient roles in deploying cloud, Internet of Things (IoT), big data, and 5G network. We have conducted a survey on network virtualization technologies, such as software-defined networking (SDN), network functions virtualization (NFV), and network virtualization overlay (NVO). For each of technologies, we have explained the comprehensive architectures, applied technologies, and the advantages and disadvantages. Furthermore, this paper has provided a summarized view of the latest research works on challenges and solutions of security issues mainly focused on DDoS attack and encryption.

• 한국자기공명학회:학술대회논문집
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• 한국자기공명학회 2002년도 제20회 학술발표회
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• pp.25-25
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• 2002

• International Journal of Computer Science & Network Security
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• 제22권10호
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• pp.303-309
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• 2022

Software Defined Networking (SDN) is a novel approach that have accelerated the development of numerous technologies such as policy-based access control, network virtualization, and others. It allows to boost network architectural flexibility and expedite the return on investment. However, this increases the system's complexity, necessitating the expenditure of dollars to assure the system's security. Network Function Virtualization (NFV) opens up new possibilities for network engineers, but it also raises security concerns. A number of Internet service providers and network equipment manufacturers are grappling with the difficulty of developing and characterizing NFVs and related technologies. Through Moodle's efforts to maintain security, this paper presents a detailed review of security-related challenges in software-defined networks and network virtualization services.

• 융합보안논문지
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• 제16권7호
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• pp.3-11
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• 2016

최근 광네트워킹 기술의 급격한 발전, SDN (Software-Defined Network) 및 NFV (Network Function Virtualization)로 대두되는 네트워크의 소프트웨어화, 그리고 단순한 고성능연결서비스를 포함한 연구협업을 가능하게 하는 플랫폼으로써의 연구망 등 인터넷 서비스을 포함한 연구망에서는 급격한 변화가 진행되고 있다. 이에 슈퍼컴과 함께 국가과학기술경쟁력을 대표하는 국가연구망의 향후 발전방향을 선진 국가연구망의 비교분석 및 사회가 요구하는 연구망의 역할 변화에 맞추어 조망해본다. 또한 국가연구망 백본의 40Gbps 및 100Gbps급 초광대역 네트워크화, 대용량의 데이터를 고속으로 전송하기 위한 Science DMZ 기반의 망분리, 마지막으로 BRO 기반 프로그래머블 가능한 캠퍼스 네트워크 Lastmile 보안 환경 구축 방안을 제시한다.