• Information and Communications Magazine
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• v.33 no.3
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• pp.46-52
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• 2016

통합공공용 주파수로 분배된LTE(Long Term Evolution) 718~728Mhz(상향) 및 773~783MHz(하향)에서 재난안전 통신망, 철도무선 통신망, 차세대 해상무선 통신망 등과 같은 LTE기반의 공공통신망(Public Network, 이하 공공망)이 상호 공존하여 사용하는 방안에 대하여 연구하였다. 두 개 이상의 복수의 LTE 네트워크가 동일 주파수를 사용하여 서비스하는 경우 통신 커버리지가 겹치는 영역에서의 간섭은 불가피하다. 셀 간 간섭에 의하여Mission Critical한 요구사항이 중요시되는 공공망에서의 품질 열화가 야기되며, 경우에 따라 심각한 상황을 초래할 수 있다. 본고에서는 국내 공공망의 현황을 살펴보고 네트워크 공유방식에 대한 기술 및 표준화 동향, 그리고 해외의 사례를 알아보았다. 국내 통합공공용 주파수에서 동일 주파수를 사용하게 될 공공망 간의 간섭을 최소화 하여 네트워크를 구축 및 연계를 위해서 개별 공공망간의 네트워크를 공유하는 방안을 고려하였다. 국내 공공망의 효율적인 네트워크 연계를 위해서는 개별 공공망의 서비스 특성과 내부 환경을 반영 할 수 있는 연계 방식이 추가적으로 필요하다.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.21 no.10
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• pp.1833-1839
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• 2017

Korea Railway is enhancing the railway wireless communication system from VHF and TRS which have been used for 100 years to LTE-R starting with Ministry of Science and ICT's allocation of Integrated Public Network Frequency on December 2014. LTE-R has advantages on technology performance, also on ease of evolution based on standardization compared to existing technologies. However there are few problems that need to be solved to provide stable railway wireless services in the future. Due to national spectrum policy, LTE-R has frequency interference with Integrated Public Networks (PS-LTE, LTE-M ) and UHD-TV which was commercialized in 2017. This paper introduces performance changes caused by interferences which were founded from the test bed in Wonju~Gangneung LTE-R project and the result of RAN-Sharing. In addition, this paper suggests the standard for LTE-R cell planning in the case of sharing the Integrated Public Network Frequency by analyzing the changes of designed link-budget factor based on the test result.

• Information and Communications Magazine
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• v.33 no.3
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• pp.53-65
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• 2016

통합공공통신망 주파수 700MHz(상향: 718~728MHz, 하향: 773~783MHz) 대역에서 국민안전처 주관으로 'PS-LTE 재난안전통신망'구축, 국토교통부 주관 '무선통신 철도제어시스템 LTE-R'구축, 해양수산부 주관 '연안 해상통신망 LTE-M'구축이 추진되고 있다. 동일 주파수 대역을 사용하지만, 서로 다른 용도로 추진되는 3개 공공통신망의 특징을 조사하여 각각의 망이 제공하고자 하는 고유한 기능, 서비스를 만족시키며 동일 주파수 대역에서 공존하기 위한 방안을, 망간 단말 이동 사례와 서비스 연동 시나리오 관점에서 분석하고 3개 공공통신망의 경제적이고 효율적인 망연동 구축방안을 제안한다.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.25 no.10
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• pp.1028-1039
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• 2014

After DTV transition, frequency allocation to efficiently utilize 700 MHz band, which is remained as Digital Dividend, is in progress domestically and internationally. This paper investigates global frequency allocation of 700 MHz band and utilization of the band, and analyzes domestic wireless technology methods and requested frequency bandwidth by use. In addition, the paper suggests what needs to be considered in case of building public integrated radio network that focuses on disaster and safety network; the integrated radio network also includes railway network and e-Navigation.

• Information and Communications Magazine
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• v.33 no.3
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• pp.66-73
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• 2016

본고에서는 미래창조과학부 공공통합망 주파수 (700MHz대역)를 사용하는 철도통합 무선통신망 (LTE-R)의 호남고속철도 익산~정읍간 시험선 구축을 통한 실용화 계획과 함께 국가 철도망 적용을 위한 노선별, 지역별 중장기 구축 계획과 최초로 사업화를 준비중인 원주-강릉 복선전철 시범사업에 대한 내용을 소개한다.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.48 no.2
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• pp.57-64
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• 2011

The NGN (Next Generation Network) means the kernel infrastructure technology to provide information and communication services which are able to be used at present and future when a ubiquitous computing era has been realized. In other words, NGN can be the frame providing the same information and communication services anytime and anywhere regardless of wire and wireless. The broadband convergence network that has been built in the public institution has established a broadband multimedia communication network supporting voice telephone, task net, internet network, video conference network, voice over IP (VoIP) network and etc. It is possible for a requested bandwidth and services to be served, only if a broadband convergence network provide the interoperability between the various classes which include a transport network layer, network control layer, service control layer and other layers. In this paper, we analyzed the interoperability issues of the present broadband convergence network and propose a guideline for the future one.

• Survey Research
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• v.10 no.2
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• pp.45-69
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• 2009

This paper explores how multiple facets of social capital in Korea affects social conflict. The notion of social capital is composed of several elements including (1) social trust in generalized others (2) confidence in public sector fairness and the principles of democracy (3) social networks and closures and (4) community spirit and collective norms. We particularly examine how these multiple dimensions of social capital affect an individual`s tendency of social conflict orientation. The findings address the following four points. First, an individual, who trusts generalized others in a society, is less likely to be exclusive and conflict-oriented. Second, the more an individual has confidence in the efficacy of democratic processes and public sector fairness, the more (s)he is likely to be social integration oriented. When an individual, in contrast, gives strong support to a particular party (or government in power), the person is more likely to be conflict oriented. Third, an individual who mobilizes exclusive social closures to solve a problem is more likely to be conflict oriented. However, an individual who maintains a variety of inclusive social networks is more likely to be social integration oriented. Finally, the internalization of collective norms does not affect directly the tendency of individual's social conflict orientation. Increasing social capital at the individual level does not automatically guarantee societal level conflict resolutions. Rather, building extensive social closures based on strong family or hometown ties, school connections, political interests has detrimental effects on social integration and conflict resolutions. More, constructive social integration in a society requires higher level of open social networks, consistent administrative and democratic procedures, and social trust in generalized others.

• TTA Journal
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• s.112
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• pp.46-54
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• 2007

본 고에서는 u-City를 구현할 때 가장 핵심적인 부가 서비스를 제공할 수 있는 대표적인 서비스의 종류를 소개하고 이 서비스들이 필요로 하는 공통적인 요구 사항을 정리한 후, 이 서비스 구현에 필요한 핵심 기술에 대해 소개하였다. 2007년 7월 현재 u-City Forum 기술 분과 위원회에서 표준화된 핵심 기술은 u-City 통합운영센터 기술과 근거리 무선 통신 기술로서 최적의 USN 아키텍처인 WiBEEM (Wireless Beacon-enabled Energy Efficient Mesh Network) 기술이다. 이 외에도 유비쿼터스 통합단말기 플랫폼 표준과 u-City를 위한 통합 코드체계 기술, 그리고 센서 데이터 포맷 표준화, u-City 시설물 관리 기술 표준화, USN 미들웨어 표준화, u-City 백본망과의 인터페이스 표준화, u-City 데이터 전송을 위한 정보 보호 표준화 등이 앞으로 추진해야 할 대상이다.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.18 no.6
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• pp.233-240
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• 2019

In this paper, due to the development of 5G communication technology, an antenna capable of covering both LTE and 5G bands is currently needed. In addition, we designed and manufactured a single feed antenna for the integrated public network (LTE) and 5G frequency dual band cover to satisfy the frequency bandwidth of more than 10% in each band. The antenna designed by adopting the dipole of the basic dipole antenna in a planar structure is a form in which the radiating element is vertically extended at all of the 700 MHz antennas and folded into a 'ㄷ' shape. In addition, the radiating element of the 700MHz band serves as a reflector of the 3.5GHz band radiating element. As a result, the 700 MHz band -10 dB bandwidth 104 MHz(14.8%) and 3.5 GHz band -10 dB bandwidth 660 MHz(18.8%) were obtained and the radiation pattern characteristic resulted in gains of 8.46 dBi, beam width E-plane 55°, H-plane 81° and 3.5 GHz bands 6.14 dBi, beamwidth E-plane 79°, H-Plane 49°.

• Journal of Korean Library and Information Science Society
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• v.35 no.1
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• pp.19-49
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• 2004

This study intends to develop a model of nation-wide library cooperative system for Korea. It analyzes and investigates the definitions, types and models of library cooperation; and current status and problems in operations of major cooperative systems in Korea and other nations. There are some cooperative systems such as cooperative system for public libraries operated by the National Library of Korea and other systems based on their regions or library types in Korea. New model of nationwide cooperative system can improve library functions through many cooperative plans.