• The KIPS Transactions:PartC
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• v.10C no.1
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• pp.111-118
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• 2003

Network reliability means network ability which perform normal operation of network components within defined time period, on the other hand, network survivability is the index of normal operation in nerwork failure. In occurrence of network failure, network operator is interested in the measurement of network survivability, but, in a view of subscribers, it is more interested in how many subscribers are out of service and how long the out of service state lasts. In this paper, a service outage evaluation model fitted for telecommunication network in Korea is proposed, which measures the impacts of subscribers in case of network failure which induces a service outage. The outage evaluation result of "Mobile to Land" service outage which has 30.000 subscribers affected for 30 minutes is 2.5. This value is 5 times larger than that of the same service outage which has 10,000 subscribers affected for 30 minutes, i.e, the impact of subscribers in the former case is 5 times larger than that of the latter case. If 30,000 subscribers have isolated in "Mobile to Land," "Local Mobile to Mobile" service for 30 minutes by the exchange out of order in PCS network, then the evaluation result of this service outage will be 3.75.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.25 no.11A
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• pp.1661-1671
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• 2000

본 고에서는 한국통신(Korea Telecom) IMT-2000 시험시스템(이하: Trial system 라고 함) 단말기용 전력증폭단으로 적용하기 위한 다단구동증폭기 및 전력증폭기를 GaAs MMIC로 설계 구현하는 기술을 제시하였다. 설계된 구동증폭기는 3단으로구성하여 RF(Radia Frequency) 송신신호(1955$\pm$70MHz)대역에서 2단 (중간단)의 이득 조정범위가 40 dB이상이 될 수 있도록 능동부품인 MESFET를 Cascade 형으로 구성하고 MESFET의 게이트(gate)에 조정전압을 인가하는 증폭기를 설계하여 GaAs MMIC화 1 침(크기4$\times$5 mm)으로 제작하였다. 아울러, 본 논문에서는 제시한 구동증폭기는 동작주파수 대역폭 범위기 3.5배이고 출력전력은 15dBmm 이며, 출력전력이득이 25~27dB이고 반사계수는 -15~20dB이며 이득평탄도 3dB(동작주파수 대역폭내)로써 Trial system용 단말기의 최종단인 전력증폭단의 출력단 특성을 효과적으로 나타내었다. 그리고, 전력 증폭기는 2개의 입력단에서 출력되는 신호를 분배하는 전력분배기와 병렬구조인 4개의 증폭단에서 출력되는 출력신호를 외부에서 접속하는 전력결합기를 접소하여 구성하였으며 RF(Radio Frequency) 주파수(1955 $\pm$70NHz)에서 대역폭을 4배로 설계하여 광대역인 대역폭을 구현하였고 출력전력은 570mW이며, 출력부가효율(PAE; Power Added Efficency)가 -15$\pm$20dB이고, 이득 평탄도(Gain flatness)는 동작주파수 대역내에서 0.5dB이며 입출력 전압정재파비(Input & Output VSWR)가 13이하인 고출력 전력증포기를 GaAs MMIC화 1칩 (크기; 3$\times$4mm)으로 제작하였다.의 다양성이나 편리성으로 변화하는 것이 국적을 바꾸는 것보다 어려운 시 대가 멀지 않은 미래에 도래할 것이다. 신세기 통신 과 SK 텔레콤에는 현재 1,300만명이 넘 는 고객이 있으며. 이들 고객은 어 이상 음성통화 중심의 이동전화 고객이 아니라 신세기 통신과 SK텔레콤이 함께 구축해 나갈 거대란 무선 네트워크 사회에서 정보화 시대를 살아 갈 회원들이다. '컨텐츠의 시대'가 개막되는 것이며, 신세기통신과 SK텔레콤은 선의의 경쟁 과 협력을 통해 이동인터넷 서비스의 컨텐츠를 개발해 나가게 될 것이다. 3배가 높았다. 효소 활성에 필수적인 물의 양에 따른 DIAION WA30의 라세미화 효율에 관하여 실험한 결과, 물의 양이 증가할수록 그 효율은 감소하였다. DIAION WA30을 라세미화 촉매로 사용하여 아이소옥탄 내에서 라세믹 나프록센 2,2,2-트리플로로에틸 씨오에스터의 효소적 DKR 반응을 수행해 보았다. 그 결과 DIAION WA30을 사용하지 않은 경우에 비해 반응 전환율과 생성물의 광학 순도는 급격히 향상되었다. 전통적 광학분할 반응의 최대 50%라는 전환율의 제한이 본 연구에서 찾은 DIAION WA30을 첨가함으로써 성공적으로 극복되었다. 또한 고체 염기촉매인 DIAION WA30의 사용은 라세미화 촉매의 회수 및 재사용이 가능하게 해준다.해준다.다. TN5 세포주를 0.2 L 규모 (1 L spinner flask)oJl에서 세포간의 응집현상 없이 부유배양에 적응,배양시킨 후 세포성장 시기에 따른 발현을 조사한 결과 1 MOI의 감염조건 하에서는 $0.6\times10^6$cell/mL의 early exponential시기의 세포밀도에서 72시간 배양하였을 대 최대 발현양을 나타내었다. 나타내었다. $\beta$4 integrin의 표현이 침투 능력을 높이는 역할을 하나 이때에는 laminin과 같은 리간드와의 특이

• Korean Security Journal
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• no.39
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• pp.269-294
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• 2014

Korea is concerned with information security industry due to recent leak-out private information of 3 card companies. Executives are aware of damage from breach of security such as personal data spill, is more dangerous than any other financial risks. The information security industry, which was limited in physical security and network security formerly, is evolving into convergence security of public and facility security industry. The field of interest has also been changed into security of smart phone and intelligence image recently, from firewall or Anti-virus. The convergence security is originally about access control of facility, but recently its demand has been increased mostly by public institutions and major companies. The scope of the industry also varies from finance, education, distribution, national defense, medical care to automobile industry. The market of convergence security has been expanded and new various products and services of security of intelligent vehicle, 'U' healthcare, finance, smart grid and key industries are also developed. It is required to create and enhance of new curriculum and cultivate human resources for the development of knowledge information security industry. Raising standard of education and security consciousness of the nation is also necessary to strengthen the global competitiveness.

• Korean Security Journal
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• no.51
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• pp.153-170
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• 2017

The purpose of this study is to rediscover the operation of anti-terrorism system focusing on the system approach and crisis management approach for counter terrorism in Korea. According to the results of this study, it is required to establish a link between open systems and integrative system focusing on functional linkage of counter-terrorism systems, and cooperative measures with private sectors in the dimension of governance activation. Further, it is necessary to prepare legal foundations for the cooperation with private sectors and then promote open consciousness transformation through the partnership with private security for anti-terrorism activities. In addition, in its preventive stage, it is required to prepare legal systems related to biochemical terrorism for stronger regulations through crisis-managerial approach. Next, in its preparatory stage, it is necessary to prepare education and enact named Terror Prevention Day for increasing terror safety consciousness, and then extend citizen reporting reward systems to enable citizens to participate and become interested voluntarily in terror prevention. Also, it is essential to establish the substantial training system for preparing for terror occurrence. Moreover, in its response stage, it is urgent to construct networks between related institutions to manage field and spot responses with integrative management systems through information sharing. Furthermore, in its restoration stage, it is indispensible to prepare long-term management systems for injured persons and families of the deceased from terror incidents.

• Journal of the Korean Society for Library and Information Science
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• v.48 no.4
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• pp.267-295
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• 2014

The purpose of this study is to analyze empirically relationships between learners' psychological factors, knowledge sourcing behavior and knowledge utilization outcomes and to analyze the mediation effect of social learning and relationships among learners. Another purpose is to understand learners' attitude on social learning and knowledge sourcing behavior. The main results of this study are as follows: First, regression results on relationships among learners' psychological factors, knowledge sourcing behavior, knowledge utilization outcomes show that learners' self-efficacy has a positive effect on social learning activity participation, and goal orientation has a positive influence on group knowledge sourcing and social learning activity participation. Users' experiences of social media has a positive effect on group knowledge sourcing, social learning activity participation and social learning interaction. From a knowledge utilization perspective, published knowledge sourcing positively affects knowledge reuse, knowledge application and knowledge innovation. Dyadic knowledge sourcing has positive influence on knowledge reuse. Group knowledge sourcing affects positively knowledge application and knowledge innovation. Second, social learning activity participation factor has full mediation effect on relationship between learners' goal orientation and group knowledge sourcing, and the relationship between users' experiences of social media and group knowledge sourcing. A relationship among members factor has full mediation effect on the relationship between published knowledge sourcing and knowledge reuse, and relationship between published knowledge sourcing and knowledge innovation. Third, the results of in-depth interview show that learners trust and easily collect knowledge from social network services in general. Also, they get a variety of idea for solving information problem from interaction among members in social learning community.

• The Korean Journal of Applied Statistics
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• v.29 no.1
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• pp.13-25
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• 2016

High-speed railway (Korea Train Express) has had a deep impact on the regional economy of Korea. Current high-speed rail research is mostly theoretical, there is a lack of quantitative research using a precise algorithm to study the effect of high-speed railway on the regional economy. This paper analyses the influence of high-speed rail on the regional economy, with a focus on the Daegu area. Quantitative analysis using department store indexes and regional medical records is performed to calculate the economic influence of high-speed rail. The result shows that high-speed railway effects the regional economy though regional consumption growth and medical care trends.

• Archives of design research
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• v.14 no.3
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• pp.145-154
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• 2001

These days, the products like Walkman, mobile phone, notebook PC, PDA are moving together with our body, and in the imaginary world like internet, our other self, Avatar is moving in place of our body on the cyber world. These products are related with our human body, and when considering the ones, attached to the human body, and having the meaning of mental combination like these, as the combination of the human and the products, it is necessary to examine these products in approaching them with respect to the combination relation between the human and the products. As a result of examining we can understand that the products, said to combine with the human body, are coming oui steadily. and recently, the inclination on the combination and the movement appears strongly. As this background, there are a breakdown of dichotomy thought, mixed sexual imitation, cyber culture, techno culture. concept of informative nomands, phenomenon which the division of human and machine becomes vague. and the miniaturization of products. imitation of human, phenomenon that the Inclination on the combination with human is more accelerated by networking. These products combine with human body at each wearing type in the various forms. Its functions become multi-layered, and closer to the human body physically. or its communication becomes high·graded and, they have the recombined form through the existing products which the human has And, they communicate each other. have the strong fashionable property, and the characteristics like the imaginary product to imitate the human body and substitute for the human behave.

• Journal of Internet Computing and Services
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• v.12 no.6
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• pp.171-187
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• 2011

Due to the vitalization of the smart phones, mobile revolution has been started. The mobile revolution has elevated SNS service, which was once considered as just one of many communication tools, to the single most important communication method as well as diffusion of social commerce. Yet, there has not been an adequate study of the roles of SNS in the domestic social commerce market, which has gotten a lot of spotlights. Therefore, the purpose of this study is to investigate the influence of various characteristics of social commerce that it has an impact on the purchase intension as well as the moderating effects of SNS. For these purposes, this study has drawn up the characteristics of social commerce in cost cutting, impulse buy, social influence, decision support, word of mouth effect and etc. to prove the interaction effect of SNS. The regression analysis showed that the characteristics of all the social commerce are related to the dependent variable. As a result of drawing up the interaction effect of SNS, it has shown that the cost cutting and word of mouth have significant influence in the social commerce diffusion as the usage of SNS increased. In conclusion, the main implication of this study is to provide the basic grounds for social commerce business strategy as it investigated the characteristics of SNS and its relation.

• Journal of KIISE:Information Networking
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• v.32 no.3
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• pp.415-426
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• 2005

Wireless internet, which becomes a hot social issue, has limitations due to the following characteristics, as different from wired internet. It has low bandwidth, frequent disconnection, low computing power, and small screen in user terminal. Also, it has technical issues to Improve in terms of user mobility, network protocol, security, and etc. Wireless internet server should be scalable to handle a large scale traffic due to rapidly growing users. In this paper, wireless internet proxy server clusters are used for the wireless Internet because their caching, distillation, and clustering functions are helpful to overcome the above limitations and needs. TranSend was proposed as a clustering based wireless internet proxy server but it has disadvantages; 1) its scalability is difficult to achieve because there is no systematic way to do it and 2) its structure is complex because of the inefficient communication structure among modules. In our former research, we proposed the All-in-one structure which can be scalable in a systematic way but it also has disadvantages; 1) data sharing among cache servers is not allowed and 2) its communication structure among modules is complex. In this paper, we proposed its improved scheme which has an efficient communication structure among modules and allows data to be shared among cache servers. We performed experiments using 16 PCs and experimental results show 54.86$\%$ and 4.70$\%$ performance improvement of the proposed system compared to TranSend and All-in-one system respectively Due to data sharing amount cache servers, the proposed scheme has an advantage of keeping a fixed size of the total cache memory regardless of cache server numbers. On the contrary, in All-in-one, the total cache memory size increases proportional to the number of cache servers since each cache server should keep all cache data, respectively.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.8
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• pp.4831-4843
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• 2014

Magazines on specific genres have been operating collaborative, co-working and collective production systems for value maximization using an adaptation strategy on the dynamic, complex and uncertain value network of the magazine industry. The study used a case study method, and data collection was performed by observational research, depth interviews and survey research. The subjects of the study were 'magazine industry', 'magazine firm and community', and 'collaboration system within creative users'. According to the research results, the ecosystem of magazines on a specific genre has been evolving into an innovative value network system, which is combined with the magazine firm, community users and magazine platform. Second, the rapid introduction of smart device environment changes the way of the collaborating system, in which an action and interaction came out within the community, creative users and magazine firms. Third, the production agency shows strong action and interaction, which fits the magazine platform within the ecosystem of a magazine on a specific genre well. This model has a similar fractal structure to the game, publishing, drama, movie, comic, and animation contents industry, converging to an innovative technology-based-creative-industry.