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The Study on Reconnaissance Surveying Using Terrestrial Laser Scanner (지상 라이다를 활용한 현황측량 연구)

  • Lee, In-Su;Kang, Sang-Gu
    • Journal of Korean Society for Geospatial Information Science
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    • v.14 no.3
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    • pp.79-86
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    • 2006
  • Nowadays 3D terrestrial laser scanners record high precision three-dimensional coordinates of numerous points on an object surface in a short period of time. So terrestrial laser scanner is applied to a wide variety of fields including geodesy, and civil engineering, archaeology and architecture, and emergency service and defence, etc. This study deals with the potential application of terrestrial laser scanner in the reconnaissance surveying. The results shows that terrestrial laser scanner is possible to extract the linear features and the positioning accuracy of objects measured by total station surveying is comparative to that by terrestrial laser scanner. Thereafter, it is expected that the potential applications of terrestrial laser scanning will be more increased by combining terrestrial laser scanners with airborne LiDAR (Light Detection And Ranging) and photogrammetric technology.

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Studies on Food Safety Knowledge of College Students according to Mass-Media Impact (대중매체 영향에 따른 일부 대학생의 식품안전 지식 조사)

  • Choi, Byung-Bum
    • The Korean Journal of Food And Nutrition
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    • v.24 no.2
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    • pp.166-172
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    • 2011
  • This study was conducted to assess food safety knowledge of college students according to mass-media reports. To accomplish this, a survey was conducted to investigate the reliability, of primary mass-media sources on Bovine Spongiform Encephalopathy(BSE) as well as the preferences of college students. The most common sources of media consumed by male and female students were terrestrial television(TV)(60%), the internet(21%), and newspapers(11%) and terrestrial TV(60%), newspapers (18%), and the internet(17%), respectively. The preferences for media of major and non-major students were terrestrial TV(64%), newspapers(17%), and the internet(14%) and terrestrial TV(51%), the internet(22%), and newspapers(19%), respectively. The reliability of media as viewed by male students were as follows: terrestrial TV(53%) and the internet(40%), whereas for female students, these values were terrestrial TV(55%) and the internet(37%). The reliability of media as viewed by major and non-major students was as follows: terrestrial TV(67%) and the internet(28%), and terrestrial TV(44%) and the internet(44%), respectively. In the case of male students, the primary sources for information regarding BSE were terrestrial TV(54%) and the internet(38%), whereas for female students, the primary sources were terrestrial TV(57%) and internet (37%). In the case of major students, the primary sources for information regarding BSE were terrestrial TV(52%) and the Internet(40%), and for non-major students, the internet(47%) and terrestrial TV(39%). Both male and female students were found to have less knowledge regarding prions, SRM(Specified Risk Materials), MM(methionine-methionine) type genes, and cow above 30 months associated with BSE compared to the other factors associated with this disease. The BSE-related knowledge held by major and non-major students was revealed unknown more than the majority of responses. Based on these results, greater effort should be made to provide meaningful information to improve the food-safety knowledge of college students according to mass-media.

A Longitudinal Time Series Study on the Viewing Behavior of Digital Media VOD Service Focused on Terrestrial VOD of IPTV for 5 years (디지털미디어 VOD 서비스 시청행태의 종단 시계열추세 연구 - 5년간 지상파VOD의 실적을 중심으로)

  • Lee, Sang-Ho
    • Journal of the Korea Convergence Society
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    • v.8 no.9
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    • pp.277-283
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    • 2017
  • This paper deals with a longitudinal time series study on the viewing behavior of digital media service. After holdback of terrestrial broadcasting VOD service was extended in 2013, viewers' terrestrial broadcasting VOD viewing went down sharply. Researcher assumed that there was driven by watching alternative products such as movies, kids, etc. as the cause of the decline of the terrestrial broadcasting VOD viewing. In addition, researcher assumed that the decline of terrestrial broadcasting VOD viewing had an influence on the viewing rate of the terrestrial real-time broadcasting, and confirmed the cause of the decreasing of the terrestrial real-time broadcasting viewing rate. In order for terrestrial broadcasters to retrieve real-time broadcasting and VOD viewing, it is necessary to shorten the VOD holdback and reacquire viewers away from terrestrial broadcasting.

Interference Mitigation Techniques for Satellite Downlink in Satellite and Terrestrial Integrated System (위성/지상 겸용망에서 위성 다운링크 수신 단말 간섭 완화 기법)

  • Kang, Kunseok;Hong, Tae Chul;Kim, Hee Wook;Ku, Bon-Jun
    • Journal of Satellite, Information and Communications
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    • v.8 no.4
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    • pp.81-88
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    • 2013
  • The satellite 2.1 GHz frequency bands, 1980-2010 MHz and 2170-2200MHz are allocated for mobile satellite service including satellite IMT, while it does not preclude the use of these bands for mobile services. The concept of an integrated satellite/terrestrial network has been introduced in worldwide because the terrestrial use in these bands adjacent to existing terrestrial IMT bands is attractive to provide mobile broadband services. The integrated satellite/terrestrial infrastructure with a high degree of spectrum utilization efficiency has the ability to provide both multimedia broadband services and public protection and disaster relief solutions. In addition, it is required to consider interference issues between the terrestrial and satellite components in order to reuse the same frequency band to both satellite and terrestrial component. This paper analyzes the interference for satellite downlink in the satellite/terrestrial integrated system and presents the interference mitigation techniques for satellite mobile earth station interfered by terrestrial base stations.

Analysis on Satellite Uplink Interference for Satellite/Terrestrial Integrated System (위성/지상 겸용망에서 위성 업링크 간섭 분석)

  • Kang, Kunseok;Hong, Tae Chul;Kim, Hee Wook;Ku, Bon-Jun;Chang, Dae-Ig
    • Journal of Satellite, Information and Communications
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    • v.9 no.1
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    • pp.107-114
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    • 2014
  • The satellite 2.1 GHz frequency bands, 1980-2010 MHz and 2170-2200MHz are allocated for mobile satellite service including satellite IMT, while it does not preclude the use of these bands for mobile services. The concept of an integrated satellite/terrestrial network has been introduced in worldwide because the terrestrial use in these bands adjacent to existing terrestrial IMT bands is attractive to provide mobile broadband services. The integrated satellite/terrestrial infrastructure with a high degree of spectrum utilization efficiency has the ability to provide both multimedia broadband services and public protection and disaster relief solutions. In addition, it is required to consider interference issues between the terrestrial and satellite components in order to reuse the same frequency band to both satellite and terrestrial component. This paper analyzes the interference for satellite uplink in the satellite/terrestrial integrated system and the interference reduction scheme for satellite uplink interfered by terrestrial user equipment.

Evaluation of Geometric Error Sources for Terrestrial Laser Scanner

  • Lee, Ji Sang;Hong, Seung Hwan;Park, Il Suk;Cho, Hyoung Sig;Sohn, Hong Gyoo
    • Journal of Korean Society for Geospatial Information Science
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    • v.24 no.2
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    • pp.79-87
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    • 2016
  • As 3D geospatial information is demanded, terrestrial laser scanners which can obtain 3D model of objects have been applied in various fields such as Building Information Modeling (BIM), structural analysis, and disaster management. To acquire precise data, performance evaluation of a terrestrial laser scanner must be conducted. While existing 3D surveying equipment like a total station has a standard method for performance evaluation, a terrestrial laser scanner evaluation technique for users is not established. This paper categorizes and analyzes error sources which generally occur in terrestrial laser scanning. In addition to the prior researches about categorizing error sources of terrestrial Laser scanning, this paper evaluates the error sources by the actual field tests for the smooth in-situ applications.The error factors in terrestrial laser scanning are categorized into interior error caused by mechanical errors in a terrestrial laser scanner and exterior errors affected by scanning geometry and target property. Each error sources were evaluated by simulation and actual experiments. The 3D coordinates of observed target can be distortedby the biases in distance and rotation measurement in scanning system. In particular, the exterior factors caused significant geometric errors in observed point cloud. The noise points can be generated by steep incidence angle, mixed-pixel and crosstalk. In using terrestrial laser scanner, elaborate scanning plan and proper post processing are required to obtain valid and accurate 3D spatial information.

A Solar Stationary Type IV Radio Burst and Its Radiation Mechanism

  • Liu, Hongyu;Chen, Yao;Cho, Kyungsuk;Feng, Shiwei;Vasanth, Veluchamy;Koval, Artem;Du, Guohui;Wu, Zhao;Li, Chuanyang
    • The Bulletin of The Korean Astronomical Society
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    • v.43 no.1
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    • pp.52.2-53
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    • 2018
  • A stationary Type IV (IVs) radio burst was observed on September 24, 2011. Observations from the Nançay RadioHeliograph (NRH) show that the brightness temperature (TB ) of this burst is extremely high, over 10^11K at 150 MHz and over 10^8K in general. The degree of circular polarization (q ) is between -60%~-100%, which means that it is highly left-handed circularly polarized. The flux-frequency spectrum follows a power-law distribution, and the spectral index is considered to be roughly -3~-4 throughout the IVs. Radio sources of this event are located in the wake of the coronal mass ejection and are spatially dispersed. They line up to present a formation in which lower-frequency sources are higher. Based on these observations, it is suggested that the IVs was generated through electron cyclotron maser emission.

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Reserch on the bamboo in Korea -Studies on the terrestrial stem of the bamboo (한국산(韓國産)의 죽류(竹類)에 관(關)한 연구(硏究) -죽(竹)의 지하경(地下莖)에 대하여-)

  • Chong, Hyon Pae
    • Journal of Korean Society of Forest Science
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    • v.2 no.1
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    • pp.10-16
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    • 1962
  • The following are what this auther concluded in his recent research of bamboo cultivation. 1. The bamboo logging should be prohibited during the months of July and August, for during that season the growth of the terrestrial stem is most vigorous and active. 2. The growth of terrestrial stem of the phyllotachys pubescens is not likely to be affected the soil texture on which it grows and it is sappling sprout out well enough in any kind of soil, but it was found out that it grows in the best condition on the sand-clay soil and in next best condition on the clay-soil. 3. The bamboo blossoming takes always most of the nutritions needed for the growth of the terrestrial stem and causes to decay 90 percent of the next year buds which await in the terrestrial stem to sprout as the sappling. The remaining 10 percent of the buds is to be the "re-incarnated bamboos" 4. The terrestrial thin roots of blossoming bamboo are negative in their growth, too weak in absorbing the nutrition. The above stated facts show, to be brief, that growth of bamboo depends largely upon that of the terrestrial stem.

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Interference-Limited Dynamic Resource Management for an Integrated Satellite/Terrestrial System

  • Park, Unhee;Kim, Hee Wook;Oh, Dae Sub;Ku, Bon-Jun
    • ETRI Journal
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    • v.36 no.4
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    • pp.519-527
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    • 2014
  • An integrated multi-beam satellite and multi-cell terrestrial system is an attractive means for highly efficient communication due to the fact that the two components (satellite and terrestrial) make the most of each other's resources. In this paper, a terrestrial component reuses a satellite's resources under the control of the satellite's network management system. This allows the resource allocation for the satellite and terrestrial components to be coordinated to optimize spectral efficiency and increase overall system capacity. In such a system, the satellite resources reused in the terrestrial component may bring about severe interference, which is one of the main factors affecting system capacity. Under this consideration, the objective of this paper is to achieve an optimized resource allocation in both components in such a way as to minimize any resulting inter-component interference. The objective of the proposed scheme is to mitigate this inter-component interference by optimizing the total transmission power - the result of which can lead to an increase in capacity. The simulation results in this paper illustrate that the proposed scheme affords a more energy-efficient system to be implemented, compared to a conventional power management scheme, by allocating the bandwidth uniformly regardless of the amount of interference or traffic demand.