• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.39A no.8
• /
• pp.474-480
• /
• 2014

In this paper, we propose a study for the next generation terrestrial broadcasting technology based on SFN(Single Frequency Networks), which applies multiple receiving antenna to improve receiving performance of cloud transmission system. By applying multiple receiving antenna, the received broadcast signals at the boundary of different SFN broadcasting area could be modelled by distributed MIMO system. Due to the interference cancellation effect of the MIMO detector, the proposed scheme could suppress the adjacent area interference more efficiently compared to the single receiving antenna case. Simulation results show that receiving performance can be improved dramatically in overlapping area of SFN by applying multiple antenna receivers in cloud transmission system.

• The Journal of the Korea Contents Association
• /
• v.13 no.11
• /
• pp.636-643
• /
• 2013

The current media and content situation is increasingly more competitive and under the radical environment changes, the social & financial position of regional broadcasting companies has been threatened. The internet & mobile based platforms and smart media, however, bring a new opportunity of content distribution. This study analyzes the current status of MBCNET which is the superstation of regional MBC stations and specialists interviews to develop the content distribution strategies of regional broadcasting companies. According to the following: finance, ratings, and new media distribution analysis, the MBCNET outcome is deemed successful based on the content library and regional power. MBCNET utilized opportunity to develop strong content resources and distribution power. In order to maintain its competitive edge, MBCNET needs to adopt the following strategies: content and platform marketing power, research & development of competitive content based on user behavior analysis, and reorganization that is able to counteract N-screen circumstances.

• Proceedings of the Korea Water Resources Association Conference
• /
• 2016.05a
• /
• pp.168-168
• /
• 2016

도시화는 수문학적으로 산림이나 농경지와 같은 투수지역을 건물, 도로 등의 불투수 지역으로 변화시키는 것이며, 이로 인하여 홍수파의 도달시간이 줄어들고 첨두유량이 증가하는 등의 수문변화를 수반하게 된다. 도로나 건물 등이 대부분을 차지하고 있는 도시지역에서는 지표면이나 식생으로부터 대기 중으로 방출되는 증발산량이 농촌이나 산림지역보다 상대적으로 적으며, 강우시 토양중의 침투량과 지표면의 저류량도 도시지역에서는 매우 적게 나타난다. 도시화 전 후의 물순환특성을 평가하기 위해서는 도시 개발 전 후의 장단기 수문 관측 결과를 기초로 물순환계를 구성하는 인자간의 관계를 정량적으로 분석하고 물순환계 구성요소의 일부 변화가 다른 부분에 미치는 영향을 평가할 필요가 있다. 즉, 도시화가 물순환 구조 변동에 미치는 영향을 정량적으로 평가함으로써 유역 전체의 건전한 물순환 체계를 유지할 수 있는 대책 수립이 가능하다. 본 연구에서는 판교신도시 개발에 따른 유역에서의 홍수 및 유출특성 변화의 정량적 규명을 목적으로 두고 집중형 모형인 HEC-HMS모형과 물리적 기반의 준분포형 모형인 CAT을 이용하여 판교신도시 개발전의 정량적 물순환 특성을 평가하였다. 대상유역은 지방 2급 하천 탄천의 지류인 운중천, 금토천이 포함된 판교유역이며, 유역면적은 약 $25km^2$이다. 이 중 유역면적의 38 %에 해당하는 지역이 개발되었으며 개발된 지역은 하류부근에 위치한다. 강우자료는 지상 강우관측소인 수원 관측소의 지점강우 자료를 이용하였다. 도시 개발 전 단계에 해당하는 2006년, 2007년 호우사상 중 누적강우량 50 mm 이상인 호우사상을 추출하여 모의를 수행하였다. 유출 특성 분석을 위해 12개의 소유역과 5개의 하도로 구성하였으며 HEC-HMS의 손실량 산정방법으로는 SCS Curve Number법을 사용하였고, 단위도는 Clark 단위 도법을 적용하였다. CAT모형에서 침투는 Rainfall Excess방법, 하도추적은 Muskingum 방법을 적용하였다. 관측치와 모의치의 적합도 검증을 위해 RMSE (Root Mean Square Error), NSE (Nash Sutcliffe Efficiency), $R^2$값을 산정하여 비교 분석하였다.

• Journal of Navigation and Port Research
• /
• v.45 no.1
• /
• pp.26-32
• /
• 2021

In ocean field, the spread of the Fourth Industrial Revolution based on information and communication technology requires high precision and stable PNT&D (Position, Navigation, Timing and Data). As the IMO (International Maritime Organization) and IALA (The International Association of Marine Aids to Navigation and Lighthouse Authorities) are requiring backup systems due to mitigate vulnerabilities and the increase of dependency on GNSS (Global Navigation Satellite System), Korea is conducting a research & development of R-Mode. An DGPS (Differentiate Global Positioning System) reference station that uses MF, an existing maritime infrastructure, and AIS (Automatic Identification System) base stations that use 34 integrity station and VHF will be utilized in this study to avoid redundant investment. Because there are radio shadow areas that display low signal levels in the west sea, the establishment of new R-Mode reference and integrity station will be intended to resolve problems regrading the radio shadow area. Because the frequency has a characteristic in that radio wave transmits well along the ground (water surface) in low frequency band, simulation and measurement were conducted therefore this paper to propose candidate sites for R-Mode reference and integrity station resulted through p wave's propagation characteristics analysis. Using this paper, R-Mode reference and integrity station can be established at appropriate locations to resolve radio shadow areas in other regions.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
• /
• v.28 no.2
• /
• pp.217-222
• /
• 2010

The geoid is the level surface that closely approximates mean sea level and usually used for the origin of vertical datum. For the computation of geoid, various sources of gravity measurements are used in South Korea and, as a consequence, the geoid models may show different results. however, a limited analysis has been performed due to a lack of controlled data, namely the GPS/Leveling data. Therefore, in this study, the gravimetric geoids are compared with the geodetic geoid which is obtained through the GPS/Leveling procedures. The gravimetric geoids are categorized into geoid from airborne gravimetry, geoid from the terrestrial gravimetry, NGII geoid(geoids published by National Geographic Information Institute) and NORI geoid(geoi published by National Oceanographic Research Institute), respectively. For the analysis, the geometric geoid is obtained at each unified national control point and the difference between geodetic and gravimetric geoid is computed. Also, the geoid height data is gridded on a regular $10{\times}10-km$ grid so that the FFT method can be applied to analyze the geoid height differences in frequency domain. The results show that no significant differences in standard deviation are observed when the geoids from the airborne and terrestrial gravimetry are compared with the geomertric geoid while relatively large difference are shown when NGII geoid and NORI geoid are compared with geometric geoid. Also, NGII geoid and NORI geoid are analyzed in frequency domain and the deviations occurs in long-wavelength domain.

• The Journal of the Institute of Internet, Broadcasting and Communication
• /
• v.15 no.1
• /
• pp.95-103
• /
• 2015

The Korea terrestrial broadcasting has TV and Radio, DMB. The TV broadcasting was converted from the analogue method to the digital method at the end of 2012. However the radio broadcasting is still in analogue method. The introduction of digital radio technology will bring many benefits such as high-quality of sound, various additional services and increase of efficiency in frequency utilization. In many countries, the radio broadcasting is been servicing in digital method. The discussion was begun on this year for the introduction of digital radio technology in Korea. So, to prepare against introduction of DAB system among digital radio technology, this paper proposes channel allocation method for each local radio broadcasting and the composition of national SFN, and proves the proposed method through the interference analysis.

• Proceedings of the Korean Society of Broadcast Engineers Conference
• /
• 2008.11a
• /
• pp.145-148
• /
• 2008

방송에서의 광고의 비중이 높아짐에 따라 광고 수익을 극대화하기 위한 기술의 발전이 활발히 이루어지고 있다. 최근의 이러한 광고 관련 기술들을 일반적으로 Advanced Advertising 이라고 하며 그 중 시청자의 선호에 맞는 광고만을 시청자에게 제공하는 타깃광고(Targeted Advertising) 방식 등 수신기별로 특화된 광고를 제공하는 기술을 클라이언트 기반 광고 삽입 방식이라고 한다. 북미의 인터랙티브 케이블방송 규격인 OCAP(OpenCable Application Platform)은 OCAP DPI(Digital Program Insertion) 라는 명칭의 클라이언트 기반 광고 삽입 방식에 대한 북미 일부 지역에서의 시험 방송의 성공한 후 관련 규격을 OCAP1.1-I01 에 발표하기에 이르렀다. 조만간 상용화되면 OCAP DPI 를 통해 북미 케이블방송 사업자들의 광고 수익 향상에 기여할 것은 물론이고 시청자들의 만족도를 향상시킬 것이다. 이런 움직임은 케이블 진영뿐만 아니라 Open IPTV Forum, ATSC 등 IPTV 나 지상파 TV 진영에서도 이 기술에 대한 타당성 검증 및 표준화가 논의가 활발히 진행되고 있는 실정이다. 본 논문은 클라이언트 기반 광고 삽입 기술에 대해 OCAP DPI 를 구현한 경험을 바탕으로 그 원리 및 동작을 설명하고, DVR(Digital Video Recorder) 또는 PVR(Personal Video Recorder)의 주요 기능인 스토리지에 방송스트림을 저장하고 재생하는 기능을 이용하는 광고 삽입 방법에 대해 제안하며, Cable-IPTV Hybrid 의 웹 접근성을 이용하여 웹 서버에 저장되어 관리 및 운용되는 광고컨텐츠의 스트리밍을 통한 광고 삽입 방법에 대한 제안하고, 마지막으로 실제 이러한 광고 삽입 기술을 적용하는 데에 있어 발생되는 문제점들을 언급하고 그 해결에 대한 의견을 제시한다.

• The Journal of the Korea Contents Association
• /
• v.17 no.10
• /
• pp.686-695
• /
• 2017

Advancement in media technology has brought about changes to the scene of ethnic minority media. As now platforms started to convey information about mother country as well as new nation. This study examines the actual status of Korean minority broadcasting companies and promoting its competitiveness through interviews and survey of media companies. The result shows that Korean ethnic broadcasting market is facing severe competition and decrease in profit by entering Korean terrestrial TV companies. Therefore, supports of Korean government is essential for promoting competitiveness of Korean minority media companies. Through voces of Korean minority media companies, we will search for find out solutions : support of production cost, supply of Korean programs, and training programs for promoting the capability of production staffs.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.22 no.1
• /
• pp.38-46
• /
• 2011

In this paper, we propose a calculation methodology of the service distance to assure the satisfactory quality of service for analogue and digital TV receivers. Using the field strength formulation for TV receiver based upon Rec. ITU-R P.1546, computational results are presented and discussed for both systems, and some important factors are reviewed in terms of the equivalent level of service, which must be kept due to ATV to DTV conversion. The presented method provides the predicted values of field strength at receiver areas to check whether transmission quality can be satisfied or not, and it can be also used for obtaining the protection ratio or separated distance from co-channel or adjacent interference signal.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.18 no.10
• /
• pp.1181-1188
• /
• 2007

This paper presents the measured signal performances in the urban environment for the DVB-H parameters such as code rate, burst size, FFT mode and modulation technique to analyze the DVB-H signal performance avaible for the embodiment of single frequency network to improve the frequency efficiency. Measurements were performed for the case for applying and non-applying MPE-FEC technique simultaneously. Results show that the most outstanding performance are found in the case of QPSK modulation, 1/2 code rate, 2 k FFT mode and 512 burst size. In addition, the signal performance by the SFN with 1/8 guard interval becomes superiour in comparision with the measured data from each site and the data from SFN with 1/32 guard interval. The analysis of the results can be instructive for the improvement of the signal performance and broadcasting quality for the terrestrial digital mobile broadcasting service.