• 디지털융복합연구
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• 제15권9호
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• pp.87-97
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• 2017

본 연구는 언론보도에 따라 소비자들의 이동통신비에 대한 인식에 어떤 변화가 발생하는지를 실험 연구를 통해 검증하고 이에 대한 정책적 시사점을 제시하였다. 무작위로 선발된 대상자를 4개의 집단(통제집단, 고비용 언론보도 노출 집단, 저비용 언론보도 노출 집단, 동시 노출 집단)에 배정한 후 언론보도에 대한 신뢰성 및 중립성, 자신의 생각과의 일치정도, 이동통신비에 대한 인식을 측정하였다. 분산분석 결과, 소비자들은 저비용 언론보도보다 고비용 언론보도를 더 신뢰하고 중립적이라고 평가하였다. 그러나 공변량 분석으로 통해 언론보도와 자신의 생각과의 일치 정도를 제거할 경우, 분산분석에서 나타났던 신뢰성과 중립성의 차이는 사라짐을 확인하였다. 또한 소비자들은 언론보도와 무관하게 이동통신비가 비싸다는 인식을 가지고 있었으며, 이동통신비가 비싸다는 기존의 인식이 새로운 정보를 받아들이지 못하게 방해하고 있음을 확인할 수 있었다. 따라서 가계통신비 인하에 대한 사회적 압력을 해소하기 위해서는 이동통신비가 비싸다는 소비자들의 고정관념을 변화시켜야 할 것이며, 프레이밍을 활용한 향후 연구도 고려할 수 있다.

• 교육시설
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• 제5권2호
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• pp.16-29
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• 1998

Bell Laboratory introduced the sound and visual system for the first time in 1927. Since then, the development of telecommunication technology made it possible for people located far away to communicate each other watching through the TV screen. Over the period different types of telelecturing systems have prospered in line with the development of telecommunication technology. Therefore, it is quite natural that telelecturing/conferending system attracts the attention of many people as a new way of educating people located in a long distance. In the industrial sector, telelecturing systems already come into wide use to save time and training and travelling expense. In this study, I examine the concept and characteristics of telelecturing/conferencing system and introduce different types telelecturing system developed in parallel with the development of communication technology. Then, I analyze how those merits of the telelecturing system can be applied to educational purpose. Finally, I propose and design ideal telelectuirng/conference facilities consisting of telelecturing rooms, bilateral movie system, seats, ceilings, color, TV screen, lighting, acoustics, humidities and temperature control, security system, projection system to maximize the educational purpose and effectiveness.

• Journal of information and communication convergence engineering
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• 제4권4호
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• pp.162-165
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• 2006

This paper presents a bandwidth efficient self-cancellation scheme for interchannel interference (ICI) in OFDM transmission systems. Conventional self-cancellation schemes provide an excellent cancellation capability of ICI for relatively low frequency offsets. However, this capability is achieved at the expense of bandwidth efficiency and thus a higher modulation level is often used to compensate for desired throughput. By applying a partial differential coding (PDC) to the transmit data prior to the ICI self-cancellation, bandwidth efficiency is greatly improved by a factor of 2, while maintaining a string of data (+1, -1) alternately for the ICI. self-cancellation in OFDM systems. Computer simulations show that the performance of the proposed scheme is comparable to the conventional self-cancellation scheme with slight performance degradation for relatively lower frequency offsets.

• 한국정보통신설비학회:학술대회논문집
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• 한국정보통신설비학회 2007년도 학술대회
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• pp.223-226
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• 2007

This paper first outlines the technology used in Power Line Communications(PLC) systems, and the political support being offered to the technology, from the point of view of its effect on electromagnetic compatibility (EMC). The radio spectrum needs protection from other interferers, and there is a regime in place to provide this interference avoidance/mitigation. Nevertheless, PLC has several features that mean that it is capable of creating such interference. These features are discussed, and some published field trial results are reviewed. Difficulties in achieving compatibility between the requirements for radio protection and the requirements for operation of the PLC system mean that there is no consensus as yet as to how PLC system components can be made compliant with EMC requirements. It is concluded that there is little prospect of an accommodation between the competing demands, so that if PLC is to become widespread it will be at the expense of the radio environment.

• 한국정보통신설비학회:학술대회논문집
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• 한국정보통신설비학회 2003년도 하계학술대회
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• pp.385-387
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• 2003

인터넷 이용자의 폭발적인 증가는 통신망 및 서비스 전반에 걸쳐 많은 변화를 야기하고 있다. 액세스계의 경우 음성전화 위주의 PSTN 시대에서는 동선을 기반으로 한 비교적 단순한 구조를 하고 있었으나 초고속 인터넷의 보급 확산에 따라 다양한 대안기술들이 등장하고 이에 따라 설비 등을 관리하기 위한 여러 종류의 시스템들이 개발 활용되고 있다. 또한 초고속망의 등장과 유무선 복합화의 추세에 따라 이용자의 Needs를 충족시키기 위한 다양한 서비스들이 출현함에 따라 고객서비스의 처리 등을 위한 관리 시스템들이 서비스에 종속적으로 개발 운용되고 있는 실정이다. 통신망 기술 및 서비스에 종속적인 형태로 개발 운용되는 기존의 OSS들로서는 현재와 같은 통신 사업자 자간의 극심한 경쟁과 서비스간의 carnivalism이 존재하는 사업환경에서는 지속적인 운용비용(Operating Expense ; OPEX)의 증가는 물론 상품/서비스의 적기 시장 출하에도 많은 지장을 초래하여 그 개선대책이 절실한 현실이다. 본고에서는 초고속인터넷 시대에서 기존의 운용관리 시스템들이 지닌 문제점을 고찰하고 이에 대한 개선 방안을 논한 후에 새로운 체계로 전환해 가기 위한 시스템의 구현시 선택 가능한 기술에 관하여 서술할 것이다.

• 한국정보통신설비학회:학술대회논문집
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• 한국정보통신설비학회 2009년도 정보통신설비 학술대회
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• pp.99-103
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• 2009

Recently, as wired and wireless communication services have rapidly developed and multimodal mobile devices which have various characteristics have widely spread, the need for new convergence services increases. The growing population of VoIP technologies and the high communication expense yield that the market of IP based telephony such as WiFi phone and IP phone is substituted for one of the conventional PSTN telephony. With the help of this trend, the wireline network operators desire to find a market in mobile networks. Therefore, they focus on Fixed Mobile Convergence (FMC) service as one of the key factors to accomplish this goal. FMC services are able to provide the mobility of voice services between circuit switched and packet switched networks. IP Multimedia Subsystem (IMS) based Voice Call Continuity (VCC) is one of the schemes to embody FMC services. As Application Server (AS) which has this VCC function provides seamless handover of services between heterogeneous networks, FMC subscribers can communicate seamlessly with others m WiFi domain and COMA domain using WiFi-COMA dual phone. Most of enterprises have already introduced IP network infrastructure and IP-PBX (Private Branch eXchange) for telephony. However, the problems of high communication cost and work inefficiency due to frequent outside jobs or business trips have remained. In order to solve these problems, demands for enterprise FMC services increase. In this paper, we introduce a new IP-PBX based VCC model that can provide seamless handover of voice services between WiFi and COMA networks for enterprise users and we investigate some interworking and security issues between Soft Switch (SSW) and IMS, or between IMSs. In addition, we introduce a new service that can provide the continuity of voice sessions as well as video sessions using Multimedia Session Continuity (MMSC) technology which has evolved from VCC. This service is expected to be one of the next-generation personalized services based on user's context.

• 공학교육연구
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• 제12권2호
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• pp.63-70
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• 2009

본 논문에서는 현재 대학 현장에서 적용하고 있는 학습성과 평가체계를 분석하여, 이를 개선한 평가체계의 모형을 국제성함양 학습성과를 예로 들어 제시하였다. 제시된 학습성과 평가체계는 PC별로 수행수준을 제시하고, 수행수준에 근거한 달성목표를 프로그램 차원에서 설정하여, 학생이 졸업 시점에서 학습성과 달성 여부를 용이하게 입증하는 체계를 갖추고 있다. 이렇게 평가체계를 구축함으로서 PC별로 CQI를 운영할 수 있어 교육현장에서의 업무를 감소할 수 있을 것이다. 또한 이러한 평가체계 수립에서 고려해야할 중요한 측면은 평가체계를 논리적이고 객관적으로 구성해야 한다는 사실을 논의하였다. 본 논문에서 제시한 학습성과 평가체계 모형은 대학 현장에서 학생의 학습성과 달성을 입증할 수 있는 용이한 모형이 될 것이라 판단된다.

• 세라미스트
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• 제21권4호
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• pp.427-432
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• 2018

In this study, the aspherical lens for optical communications produced not with an one-step pneumatic type of external pressurization system (existed GMP process) but a constant weight of self-loaded mold put up to upper core. So the lens is molding with self-loaded weight molding and it calls Weight Molding process. In self-loaded molding process, we measured changes of center thickness molding lenses with each variable molding temperatures and time to find the effect of center of lens thickness to search key factors. As experimental results, the center thickness reach to targeted lenses step time value was changed drastically and it depends by molding temperature. If the molding temperature gets higher, the targeted lens that is reaching to the center thickness step time value was decreased. To find the effect of life improvement on mold core by imposing the self-loaded molding process we molded with GMP(Glass molding press) method and self-loaded molding method for 9,000 times and measured the lenses shape accuracy and surface roughness to evaluate the core life. As a result the self-loaded molding method core has 2,000 times longer that GMP (Glass molding press) method. If we adopt self-loaded molding method of the optical aspherical lens molding in the future, we expect that it would reduce the expense of changing the molds by molding core life improvements.