• Journal of the Korean Association of Geographic Information Studies
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• v.26 no.4
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• pp.130-144
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• 2023

Recently, various positioning technologies are being researched based on signal-based positioning and image-based positioning to obtain accurate indoor location information. Among these, various studies are being conducted on image positioning technology that determines the location of a mobile terminal using images acquired through cameras and sensor data collected as needed. For video-based positioning, a method of determining indoor location is used by matching mobile terminal photos with virtual landmark images, and for this purpose, it is necessary to build indoor spatial information about various landmarks such as billboards, vending machines, and ATM machines. In order to construct indoor spatial information on various landmarks, a panoramic image in the form of a road view and accurate 3D survey results were obtained through c 13 buildings of the Electronics and Telecommunications Research Institute(ETRI). When comparing the 3D total station final result and the terrestrial lidar panoramic image coordinates, the coordinates and distance performance were obtained within about 0.10m, confirming that accurate landmark construction for use in indoor positioning was possible. By utilizing these terrestrial lidar achievements to perform 3D landmark modeling necessary for image positioning, it was possible to more quickly model landmark information that could not be constructed only through 3D modeling using existing as-built drawings.

• Korean journal of communication and information
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• v.48
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• pp.63-89
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• 2009

The contents provided by the terrestrial broadcasters have governed the market based on their excellent quality in Korea. In spite of the launching of various pay TV services focusing on multi-channel, it is not yet easy to find out the substitutionary pay TV channels for the terrestrial. Therefore, the real time retransmission of the terrestrial channels brings about the crucial effects on the pay TV's competency, especially on the new media as the invisible barrier. So it is frequently proposed to change the aim of the retransmission policy from the universal access to the promotion of media industries. The retransmission can be divided into two types as the must carry and retransmission consent. In Korean situation, keeping or reducing the must carry channel would be appropriate rather than expanding them. However, periodic investigation into the public effects of the must carry is necessary, instead of it. Moreover, the rational and fair monetary compensation for the commercial channels(MBC, SBS, KBS2) is arising as the bottle neck in the retransmission agreements between the broadcasters. The conjoint analysis was carried out to estimate the welfare growth from the retransmission, based on the stated preference from the audiences' point of view. For must carry channels, it was certified as the 'win-win' strategy for both sides and audiences. For the commercial channels, it is revealed to be beneficial to the audiences. Thereafter, the standards for the rational price were suggested to promote the retransmission. This can contribute for inspiring the dynamic vitality to the media industry by reinforcing the contents competencies and for establishing the long term growth strategies.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2018.10a
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• pp.457-460
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• 2018

The mobile communication based train control is the train control system by utilizing wireless communication rather than conventional wired communication. Traditional train control operates train occupation, safety integrity and moving authority using fixed block wired railway signal system. Since introduction of mobile communication in railway area, railway operators can provide improved passager services. Futhermore, it can replace inefficient train onboard equipments and railway ground facilities for economic benefits. In this paper we introduce mobile communication based railway system currently in operation around the world. Moreover, we provide the minimum requirements of the radio communication performance. Proposed minimum requirements of the radio communication improve more secure and efficient mobile communication based train control system.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.48 no.6
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• pp.35-47
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• 2011

A present experimental broadcasting is service compatible to delivery left view and right view of a dual stream for backward compatible with 2D device. It has a limitation of quality for a transmission of dual stream in terrestrial bandwidth 19 Mbps. This paper proposes adjunct terrestrial-3D broadcasting system which can provide a stable quality beyond a limitation of quality from fixed bandwidth. It proposes the system that composes a high quality stereoscopic video through synchronizing Real time broadcasting and Non Real Time broadcasting Regardless of the terrestrial bandwidth. So this paper tries to analyze each technique of Real-Time broadcasting and NRT broadcasting, and verify this proposal through the technique of an algorithm that we can implement NRT adjunct high quality 3DTV system and the experiments.

• Journal of Satellite, Information and Communications
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• v.7 no.3
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• pp.121-129
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• 2012

Any development plan of a Korean space-based navigational system has been neither designed nor introduced yet. However, the demand for the development of a domestic regional satellite navigation system can be originated from the outside of market. The growing dependency on satellite navigational systems in Korea eventually requires the retainment and the operation of a domestic navigational satellite system. There is not many choices on the orbit designs and the system design concepts of a regional augmented navigation satellite system or a regional navigation satellite system for the service on the vicinity of the Korean peninsular. Space situational awareness (SSA) has been a rising issue for both national security and more realistic space business in Korea. Also SSA related technologies in Korea is a newly inaugurated area and is necessary to generate a navigation messages and maintain a future Korean navigation satellite system. In this study, the availability of Japanese Quasi Zenith Satellite System (QZSS) expected to be deployed definitely sooner than Korean counter-part is analyzed. The availability of the similar configured system over Korea is investigated with assumed QZSS type orbit. Also, feasible configuration of orbits for domestic navigation satellite system is suggested. And the observability of a ground-based optical tracking system as a secondary tracking capability is analyzed.

• The KIPS Transactions:PartD
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• v.11D no.6
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• pp.1259-1268
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• 2004

To organize training in limited training area for an actuai combat, realistic training simulation plugged in by various battle conditions is essential. In this paper, we propose a virtual target overlay technique which does not use a virtual image, but Projects a virtual target on ground-based CCD image by appointed scenario for a realistic training simulation. In the proposed method, we create a realistic 3D model (for an instructor) by using high resolution Geographic Tag Image File Format(GeoTIFF) satellite image and Digital Terrain Elevation Data (DTED), and extract the road area from a given CCD image (for both an instructor and a trainee). Satellite images and ground-based sensor images have many differences in observation position, resolution, and scale, thus yielding many difficulties in feature-based matching. Hence, we propose a moving synchronization technique that projects the target on the sensor image according to the marked moving path on 3D satellite image by applying Thin-Plate Spline(TPS) interpolation function, which is an image warping function, on the two given sets of corresponding control point pair. To show the experimental result of the proposed method, we employed two Pentium4 1.8MHz personal computer systems equipped with 512MBs of RAM, and the satellite and sensor images of Daejoen area are also been utilized. The experimental result revealed the effective-ness of proposed algorithm.

• Broadcasting and Media Magazine
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• v.20 no.4
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• pp.46-57
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• 2015

ATSC 3.0은 세계 최초의 IP 기반 지상파 방송 시스템으로 전통적인 방송 시스템에서 고려되지 않았던 혁신적인 기술들을 포함하고 있다. ATSC 3.0 표준을 준수하는 방송 시스템은 유연한 서비스 구성 및 개인형 서비스의 공급이 가능하여 미디어 환경 변화에 따른 시청자들의 다양한 요구를 충족시킬 수 있을 것으로 기대되고 있다. 본 논문에서는 ATSC 3.0의 IP 기반 하이브리드 전송 기술 및 컴페니온 스크린 기술에 대하여 분석한다.

• Broadcasting and Media Magazine
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• v.8 no.2
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• pp.44-57
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• 2003

최근 ATSC DASE 기반의 지상파 데이터방송 실험방송의 성공적인 수행 및 DVB MHP 기반의 위성 데이터 방송에 대한 일반인의 관심이 급속히 증대되고 있는 반면, 매체간 규격이 상이한 관계로 데이터방송 콘텐츠의 메체간 재전송 및 콘텐츠의 재사용에는 어려움이 예상되고 있다. 이에 매체간 호환성을 확보하기 위한 노력으로 공통 규격을 만들려는 Harmonization 활동이 본격적으로 이루어지고 있다. 따라서 본 고에서는 최근의 데이터방송 표준화 동향을 살펴보고 현재 진행중인 Harmonization 현황과 향후 전망을 살펴본다.

• Information and Communications Magazine
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• v.33 no.7
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• pp.18-24
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• 2016

본고에서는 MPEG에서 설계하여 ISO 표준화한 실시간/저지연 미디어 전송 기술인 MMT (MPEG Media Transport) 에 대해 알아본다. MMT는 인터넷 환경과 통합된 차세대 방송 시스템에의 적용을 목표로 설계된 기술로, IP 기반 전송 프로토콜의 사용과 HTML5 기반 서비스 제공을 가정하여 MPEG2-TS의 장점을 계승하면서 이종망 및 다기기 서비스의 지원을 고려하여 설계 되었다. 따라서 MMT는 고품질의 UHD TV서비스를 안정적으로 제공함과 동시에 인터넷 활용 부가 서비스 제공을 목적으로 하는 차세대 지상파 방송에 있어 최적화된 표준 기술이라 할 수 있다.

• Korean Journal of Remote Sensing
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• v.35 no.5_1
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• pp.705-714
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• 2019

Precision positioning is necessary for various use of high-resolution UAV images. Basically, GCP is used for this purpose, but in case of emergency situations or difficulty in selecting GCPs, the data shall be obtained without GCPs. This study proposed a method of improving positional accuracy for x, y coordinate of UAV based 3 dimensional point cloud data generated without GCPs. Road vector file by the public data (Open Data Portal) was used as reference data for improving location accuracy. The geometric correction of the 2 dimensional ortho-mosaic image was first performed and the transform matrix produced in this process was adopted to apply to the 3 dimensional point cloud data. The straight distance difference of 34.54 m before the correction was reduced to 1.21 m after the correction. By confirming that it is possible to improve the location accuracy of UAV images acquired without GCPs, it is expected to expand the scope of use of 3 dimensional spatial objects generated from point cloud by enabling connection and compatibility with other spatial information data.