• 한국전자거래학회지
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• 제18권2호
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• pp.205-222
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• 2013

최근 IT분야의 중요한 화두인 융합은 이전까지는 단순히 기술의 기능적인 융합에서 이루어져 왔다면, 최근에는 비즈니스 측면, 서비스 측면에서의 융합도 이루어지고 있다. 이러한 대표적인 유형으로서 방송통신융합은 방송산업의 디지털 전환으로 인하여 다매체, 다채널화 등과 같은 방송기술이 통신산업의 네트워크 광대역화와 융합이 가능해지면서 IPTV와 같은 융합서비스들을 출현시키게 되었다. IPTV는 방송과 통신의 융합이 본격화되면서 네트워크, 콘텐츠, 단말기의 융합이 종합적으로 결합된 새로운 서비스이다. 그럼에도 불구하고 IPTV가 인터넷TV와 무엇이 다르고 IPTV를 통해 소비자가 얻을 수 있는 편익이 무엇인지 등 새로운 융합서비스의 범위와 가치에 대해 논란이 제기되고 있다. 본 연구는 N-Screen 기반 IPTV서비스의 요구기능을 확인하기 위하여 해당 서비스에 대한 기대수준과 사용 후의 인지수준을 측정하기 위해 서비스에 대한 중요도와 만족도의 차이를 분석하고, IPA분석을 통해 각 항목별로 우선순위를 제시하였다. 이를 토대로 방송통신융합서비스 기능에 대해 제공자와 사용자 간의 인식수준 차이(Gap)를 규명하고, 사용자 만족도 제고를 위한 방안을 제시하고자 한다.

• 유통과학연구
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• 제15권12호
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• pp.53-60
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• 2017

Purpose - This paper analyzes the effect of the handset subsidy and the Mobile Number Portability subscriber subsidy regulation, which are the main regulation adopted in "Law on the Improvement of the Mobile Terminal Distribution System" (Mobile Terminal Distribution Act), on the social surplus, the consumer surplus and profits of telecommunications carriers. We focus our analysis on whether the service charge competition is stimulated enough so that it can compensate for the loss of subsidies. Research design, data, and methodology - We use simple economic model to assess the impact of the handset subsidy and the Mobile Number Portability subscriber subsidy regulation. Unlike the former researches on this topic, we depart from using Hotelling model, and instead use the switching cost model, which uses switching cost as a parameter of market powers of telecommunications carriers. We also study the effect of the two different regulations when they are adopted both independently and concurrently. Results - If the market powers of telecommunications carriers are over certain threshold, contrary to the regulatory agency's assertion, the service charge competition would not be stimulated enough to compensate for the deduction in the subsidies, and thus the consumer surplus is compromised. Number Portability subsidy, especially, undermines the rival's market power and thus reduces the service charge. On the other hand, the regulations will also increase the profits of telecommunications carriers. However, social surplus is maximized when both of the regulations are present because the regulations reduces the frequency of switching handsets inefficiently. Conclusions - In enacting the Mobile Terminal Distribution Act, the telecommunications regulatory agency asserted that the regulation on subsidies will stimulate service charge competition, and in the long run, enhance the consumer surplus. However, contrary to the regulatory agency's assertion, subsidy regulation, especially the regulation on Number Portability subsidy, reduces consumer surplus. On the other hand, the Mobile Terminal Distribution Act can also increase the profits of telecommunications carriers because it decreases competition among the telecommunications carriers. However, the Mobile Terminal Distribution Act can increase the social surplus because it reduces inefficient switching of handsets.

• ETRI Journal
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• 제21권3호
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• pp.6-15
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• 1999

Many studies in the software reliability have attempted to develop a model for predicting the faults of a software module because the application of good prediction models provides the optimal resource allocation during the development period. In this paper, we consider the change request data collected from the field test of the software module that incorporate a functional relation between the faults and some software metrics. To this end, we discuss the general aspect if regression method, the problem of multicollinearity and the measures of model evaluation. We consider four possible regression models including two stepwise regression models and two nonlinear models. Four developed models are evaluated with respect to the predictive quality.

• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 2006년도 International Symposium on GPS/GNSS Vol.1
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• pp.109-113
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• 2006

This paper presents an in-flight alignment method for strapdown inertial navigation systems based on the line-of-sight information. Unlike the existing methods, the proposed method utilizes only the 2-axis angle measurements of the onboard image sensor and does not require any explicit range measurements between the vehicle and landmarks. To improve the accuracy of all the position, velocity, and attitude estimates through the in-flight alignment, an error model of the image-sensor-aided SDINS is derived. A simulation study demonstrates that the accuracy of SDINS can be improved by the line-of-sight information only.

• 항공우주산업기술동향
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• 제8권1호
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• pp.112-117
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• 2010

본 논문에서는 2007년도에 국제전기통신연합에서 주최한 세계전파통신회의에서 의결 사항인 항공 이동용 텔레메트리 주파수 스펙트럼 국제 분배 내용과 분배이후에 국제사회 동향과 국내 주파수 정책의 변화에 대하여 자세히 기술하였다. 또한, 전 세계적으로 주파수 분배기구인 국제전기통신연합과 주파수 관련 회의인 세계전파통신회의에 대해서 간략하게 설명하였다.

• International Journal of Advanced Culture Technology
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• 제10권3호
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• pp.397-403
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• 2022

The world is paying a lot of attention to digital twins to preoccupy future technological competitiveness. Digital twins can be used in various fields such as manufacturing, medical care, and cities. Various market research institutes predict that the market size of digital twins will gradually expand. Korea has also selected digital twin as one of the representative tasks of the Korean version of the New Deal and is promoting related policies. However, a common platform or standard for building digital twins is not enough. Interoperability is a very important characteristic for the purpose of creating new value through interconnection between digital twins rather than independently developing and utilizing digital twins. The Digital Twin Consortium is an international council for the effective development and utilization of digital twins, and is working to solve the problem of digital twin interoperability. The Digital Twin Consortium recently published the 'Digital Twin System Interoperability Framework', and this paper analyzes the digital twin interoperability based on it.

• 한국정보기술학회 영문논문지
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• 제9권2호
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• pp.99-105
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• 2019

In this paper, we describe the procedure of simulation design and measured results of a compact planar antenna for handset applications. The broad bandwidth covering the interested frequency band for mobile handset is achieved by introduction of an open ended L-shaped slot which is newly proposed and corresponds to the monopole slot. In order to minimize the impact on circuit part placement, the proposed antenna is placed on the ground plane edge of PCB with size of 60×65 mm². The measurement result for 10dB impedance bandwidths is 640 MHz (1.7~2.34 GHz), covering the required bandwidths for DCS (Digital Cellular System)-1800 (1710 ~ 1880 MHz) / IMT (International Mobile Telecommunication)-2000 (1885 ~ 2200 MHz) bands. In particular, we would like to emphasize the proposed antenna has an omnidirectional radiation pattern suitable for commercial wireless communication.

• 한국통신학회논문지
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• 제42권4호
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• pp.703-715
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• 2017

본 논문은 장거리 공중-지상 가시선 링크에서 대용량 영상정보용 데이터링크의 무선채널 특성을 분석하고 공중-지상 채널의 협대역 및 광대역 간섭이 대용량 데이터링크의 수신 신호에 미치는 영향을 수학적으로 분석하는 방법을 제안한다. 제안된 성능분석 방법을 이용하여 통신거리에 따른 수신성능을 분석하였고 지면 반사파의 협대역 및 광대역 간섭에 의해 통신거리가 제한됨을 확인하였다. 또한 수신 안테나를 상향으로 제어하는 방법의 성능분석 결과, 협대역뿐만 아니라 광대역 간섭도 효과적으로 제거함으로써 별도의 등화기를 포함하지 않은 기존 대용량 데이터링크 장비로도 통신거리를 증가시킬 수 있음을 확인하였다.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2013년도 추계학술대회
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• pp.823-826
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• 2013

구내 통신 선로에 유입되는 낙뢰나 유도에 의한 서지로부터 통신 설비 및 이용자를 보호하기 위하여 국선과 구내 케이블의 접속 지점에 외부로부터의 과전압 또는 과전류를 차단하기 위한 보호기를 설치하고 있다. 국내에서 이러한 보호기에 대한 설치 의무 및 성능 기준 등을 기술기준으로서 규정하고 있으나 현행 기술기준은 PSTN 서비스에 기반을 두어 수립된 기준으로 통신 기술의 발전에 따른 서비스의 다변화에 대응하고 있지 못하고 있다. 지난 연구에서 이러한 구내통신설비의 가입자 보호기 기술기준에 대한 개선 방향에 대한 제언을 한 바 있으며 이에 본 논문에서는 구내 통신용 보호기의 성능 기준 중 과전압 제한 성능 기준을 개정안을 마련하고 이의 검증을 위한 시험을 통해 개정안에 대한 타당성을 제시한다.

• 한국군사과학기술학회지
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• 제24권6호
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• pp.645-654
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• 2021

In this paper, we proposed a protocol to convert 2W telephone analog signals to Ethernet data in a private PSTN 2W tactical voice system. There are several kinds of operational problems in the tactical telephone network where 2W telephone copper lines are installed hundreds of meters away from the PBX in a headquarter site. The reason is that it is difficult to install and maintain the 2W telephone copper cable in severe operational fields and to meet safety and stability operational requirements of the telephone line under lighting and electromagnetic environments. In order to solve these challenging demands, we proposed an efficient method that the 2W analog interface signals between a private PBX system and a 2W telephone is converted to Ethernet messages using the optical Ethernet data communication network already deployed in the tactical weapon system. Thus, it is not necessary to install an additional optic cable for the ethernet telephone line and to maintain the private PSTN 2W telephone network. Also it provides safe and secure telecommunication operation under lightning and electromagnetic environments. This paper presents the conversion protocol from 2W telephone signals over Ethernet interface between PBX systems and 2W telephones, the mutual exchange protocol of ethernet messages between two converters, and the rule to process analog signal interface. Finally, we demonstrate that the proposed technique can provide a feasible solution in the tactical weapon system by analyzing its performance and experimental results such as the bandwidth of 2W telephone ethernet network and the transmission latency of voice signal, and the stability of optic ethernet voice network along with the ethernet data network.