• Journal of Korean Society for Geospatial Information Science
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• v.14 no.3 s.37
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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.

• 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.

• 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.

• 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.

• 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.

• 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.

• Journal of Environmental Science International
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• v.31 no.6
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• pp.479-490
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• 2022

This study was to evaluate the utilization of terrestrial light detection and ranging for forest inventory in coniferous forests. Heights and diameter of the stand trees were measured manually using the traditional measurement method and the method using terrestrial LiDAR. The results of two methods were compared and analyzed to evaluate accuracy and feasibility. The terrestrial LiDAR used fixed and handy types to compare the accuracy between different operational methods. Comparative analyses used a paired t-test and Bland-Altman plot analysis. In the case of tree heights, the average of difference between the traditional method and terrestrial LiDAR for each plot was 0.81 m, -0.07 m, and 0.13 m for fixed type; 2.88 m, 1.19 m, and 0.93 m for the handy type. In the case of tree diameter at breast height, the average value of the difference between traditional methods and terrestrial LiDAR for each plot was 0.13 cm, -0.66 cm, and -0.03 cm for fixed type; 2.36 cm, 2.13 cm, and 1.92 cm for the handy type. The values from the method using the fixed type was highly consistent with that using the traditional measurement methods; the average difference was closer to zero. The crown density influences the precision of the height measurement using terrestrial LiDAR in coniferous forests. Therefore, future studies should focus on verifying the accuracy of terrestrial LiDAR in forests and on expanding the utilization of terrestrial LiDARs according to their operational methods.

• ETRI Journal
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• v.46 no.2
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• pp.238-249
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• 2024

Equivalent-time sampling can improve measurement or sensing systems because it enables a broader frequency band and higher delay resolution for periodic signals with lower sampling rates than a Nyquist receiver. Meanwhile, a digital down-conversion (DDC) technique can be implemented using a straightforward radio frequency (RF) circuit. It avoids timing skew and in-phase/quadrature gain imbalance instead of requiring a high-speed analog-to-digital converter to sample an intermediate frequency (IF) signal. Therefore, when equivalent-time sampling and DDC techniques are combined, a significant synergy can be achieved. This study provides a parameter design methodology for optimal equivalent-time sampling using DDC.

• The Journal of the Korea institute of electronic communication sciences
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• v.8 no.12
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• pp.1825-1832
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• 2013

Since domestic terrestrial DTV transition introduces the need for a multi-channel service as raised again to multi-channel service is being promoted. Current terrestrial broadcasters to realize multi-channel services are provided jointly countermeasures. Multi-channel services also active in policy-making of Korea Communications Commission. Therefore, in this article, terrestrial technical issues that arise in multi-channel services and services for the implementation of policy measures were proposed. Therefore, in this article terrestrial technical issues that arise in multi-channel services and services for the implementation of policy measures by looking at the future terrestrial multi-channel service to pursue the direction and policies of regulatory agencies aims to help.

• 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.