• Journal of Communications and Networks
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• v.18 no.6
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• pp.948-961
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• 2016

Internet protocol (IP) spoofing is a serious problem on the Internet. It is an attractive technique for adversaries who wish to amplify their network attacks and retain anonymity. Many approaches have been proposed to prevent IP spoofing attacks; however, they do not address a significant deployment issue, i.e., filtering inefficiency caused by a lack of deployment incentives for adopters. To defeat attacks effectively, one mechanism must be widely deployed on the network; however, the majority of the anti-spoofing mechanisms are unsuitable to solve the deployment issue by themselves. Each mechanism can work separately; however, their defensive power is considerably weak when insufficiently deployed. If we coordinate partially deployed mechanisms such that they work together, they demonstrate considerably superior performance by creating a synergy effect that overcomes their limited deployment. Therefore, we propose a universal anti-spoofing (UAS) mechanism that incorporates existing mechanisms to thwart IP spoofing attacks. In the proposed mechanism, intermediate routers utilize any existing anti-spoofing mechanism that can ascertain if a packet is spoofed and records this decision in the packet header. The edge routers of a victim network can estimate the forgery of a packet based on this information sent by the upstream routers. The results of experiments conducted with real Internet topologies indicate that UAS reduces false alarms up to 84.5% compared to the case where each mechanism operates individually.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.41 no.3
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• pp.162-169
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• 2018

Net neutrality, which has not been a problem, has recently become a problem for ISPs (Internet Service Providers), and their complaints have been paid by domestic platform companies, but overseas global IT companies such as Google and YouTube, generate huge revenues from domestic markets. In this situation, domestic IT companies claim that it is natural to impose more expensive charges or restrict speed on users who generate huge traffic. On the other side, however, the telecommunication network has become an essential public good that is essential to our everyday life, and because it has been given a monopoly position by a private company to efficiently respond to the explosive demand for telecommunication services, It is necessary to provide equal and universal service and fulfill public duty. In this paper, we deal with the network neutrality problem, focusing on the price elasticity between the CP (Contents Provider) and the ISP, rather than the user who is one side of the two-sided market for the already saturated satellites communication market. We present a game model that determines the optimal price for each platform by Nash equilibrium and analyze how the net neutrality affects CP according to the change of exogenous variables through the proposed game model.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2002.11a
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• pp.924-927
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• 2002

In (equation omitted) 2002, Study Croup on Long-Run Incremental Cost(LRIC) Model of Japan compiled its report. In this (equation omitted) shows there are three ways of inter-islands and island to land telecommunication service, radio communication, suboptical, communication satellite. Analysis of Japanese island network model is helpful in developing Korean island network model. The development of Korean island network model will make use of local loop unbundling, universal service fund and access charge.

• ETRI Journal
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• v.39 no.5
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• pp.695-706
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• 2017

This paper presents a caching algorithm that offers better reconstructed data quality to the requesters than a probabilistic caching scheme while maintaining comparable network performance. It decides whether an incoming data packet must be cached based on the dynamic caching probability, which is adjusted according to the priorities of content carried by the data packet, the uncertainty of content popularities, and the records of cache events in the router. The adaptation of caching probability depends on the priorities of content, the multiplication factor adaptation, and the addition factor adaptation. The multiplication factor adaptation is computed from an instantaneous cache-hit ratio, whereas the addition factor adaptation relies on a multiplication factor, popularities of requested contents, a cache-hit ratio, and a cache-miss ratio. We evaluate the performance of the caching algorithm by comparing it with previous caching schemes in network simulation. The simulation results indicate that our proposed caching algorithm surpasses previous schemes in terms of data quality and is comparable in terms of network performance.

• ETRI Journal
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• v.29 no.5
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• pp.569-595
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• 2007

Particularly in wireless communications, link errors severely affect the quality of the services due to the high error probability and the specific error characteristics (burst errors) in the radio access part of the network. In this work, we show that thorough analysis and appropriate modeling of radio-link error behavior are essential to evaluate and optimize higher layer protocols and services. They are also the basis for finding network-aware cross-layer processing algorithms which are capable of exploiting the specific properties of the link error statistics, such as predictability. This document presents the analysis of the radio link errors based on measurements in live Universal Mobile Telecommunication System (UMTS) radio access networks as well as new link error models originating from that analysis. It is shown that the knowledge of the specific link error characteristics leads to significant improvements in the quality of streamed video by applying the proposed novel network- and content-aware cross-layer scheduling algorithms. Although based on live UMTS network experience, many of the conclusions in this work are of general validity and are not limited to UMTS only.

• The Southeast Asian review
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• v.28 no.1
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• pp.173-218
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• 2018

This study focuses on the healthcare sector in Vietnam which is promoting universal health insurance for the achievement of Universal Health Coverage (UHC) under Sustainable Development Goals (SDGs). The purpose of this study is to examine the characteristics of the reform process of the health care system and the law on health insurance through the historical and cultural contexts and its implications from the perspective of development. Based on the three dimensions of UHC - extension of protection for population, provision of various medical services, and financial protection, the current status of the Vietnam healthcare sector is summarized respectively as follows. First, according to the revised Health Insurance law which came into effect in 2015, the mandatory health insurance premiums are calculated based on household units. Second, there is a medical network that can provide preventive and healthcare services centered on primary health care facilities, for example commune health stations (trạm y $t{\hat{e}}$ $X{\tilde{a}}$). Third, out-of-pocket expenditure is still a large proportion although public spending has increased and private spending has decreased since the enforcement of the health insurance law and various schemes. Vietnam is currently striving towards a universal health care system. The development of institutions and systems should be designed in a way that is appropriate for the members of the society rather than efficiency. This article findings shed light on the role of social values, family culture, and informal institutions.

• Journal of Digital Convergence
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• v.18 no.2
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• pp.103-110
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• 2020

The fire incident of KT's Ahyun branch occurred last year indicates that hyper-connected society led by 5G technology would be a dystopia instead of a utopia unless seamless connection of 5G service is well secured. Looking backward on 1999, we could peacefully and happily greet the new millennium by making a great effort to prevent the millennium bugs(Y2K) from causing the catastrophe such as a shut-down of banking system. Likewise, we should make a great effort to keep 5G networks and 5G service continuously working without the disruption of even just a second, which would enable us to avoid facing any catastrophes caused by the disruption of 5G service. As a way to do so, it can be considered that 5G service is designated as universal service because it has the key features of public goods like telephone and high-speed internet services.

• IMMUNE NETWORK
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• v.24 no.3
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• pp.19.1-19.15
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• 2024

The influenza virus poses a global health burden. Currently, an annual vaccine is used to reduce influenza virus-associated morbidity and mortality. Most influenza vaccines have been developed to elicit neutralizing Abs against influenza virus. These Abs primarily target immunodominant epitopes derived from hemagglutinin (HA) or neuraminidase (NA) of the influenza virus incorporated in vaccines. However, HA and NA are highly variable proteins that are prone to antigenic changes, which can reduce vaccine efficacy. Therefore, it is essential to develop universal vaccines that target immunodominant epitopes derived from conserved regions of the influenza virus, enabling cross-protection among different virus variants. The internal proteins of the influenza virus serve as ideal targets for universal vaccines. These internal proteins are presented by MHC class I molecules on Ag-presenting cells, such as dendritic cells, and recognized by CD8 T cells, which elicit CD8 T cell responses, reducing the likelihood of disease and influenza viral spread by inducing virus-infected cell apoptosis. In this review, we highlight the importance of CD8 T cell-mediated immunity against influenza viruses and that of viral epitopes for developing CD8 T cell-based influenza vaccines.

• Proceedings of the Korea Institutes of Information Security and Cryptology Conference
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• 2006.06a
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• pp.506-510
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• 2006

3G 이동통신기술중 하나인 UMTS(Universal Mobile Telecommunications System)에서는 무선 구간의 안전한 통신을 위해 UMTS-AKA(Authentication and Key Agreement) 프로토콜이 사용된다. 그러나 SN(Serving Network)과 HN(Home Network)의 통신량 소비 문제, SQN(SeQuence Number) 동기화 문제 등 여러 가지 문제점이 제기되었다. 본 논문에서는 기존 프로토콜의 문제점과 IMSI(International Mobile Subscriber Identity)의 노출로 인한 프라이버시 문제점을 해결하고, ECDH(Elliptic Curve Diffie Hellman) 기법으로 완전한 전방향 안전성을 제공하는 프로토콜을 제안한다.

• Journal of Korea Technology Innovation Society
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• v.3 no.2
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• pp.33-47
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• 2000

We focus on the investigations of the effect of social networks on the diffusion of innovations, in order to successfully bring innovations into markets. We begin with consideration of social system from Rogers(1995)' perspective, which includes the fifty-year sequential tradition of diffusion studies, and expand the conceptualization into a framework for thinking about the effect of social networks on the diffusion of innovations. We draw upon basic ideas from the research traditions of social network theory in sociology, and social identity theory in social psychology. Finally, we offer propositions for the future empirical researches. A better understanding of social networks can complement research on the diffusion of innovations and help in the development of a universal model of consumer response to innovations.