• The Journal of the Korea institute of electronic communication sciences
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• v.15 no.3
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• pp.553-562
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• 2020

S-band, C-band and X-band radars are used for weather observation purposes. Since the Meteorological Administration, the Ministry of Environment, and Republic of Korea Air Force operate radars according to the purpose of observation by departments, the installation site and observation characteristics are different. From a meteorological point of view, blind observational areas in the low level with an elevation of less than 1 km around the mountainous terrain near Jirisan and Taebaeksan. Assuming a small radar installation, we simulated low-level observations. In order to monitor dangerous weather in North Korea, we analyzed the precipitation of North Korea and simulated a large radar network. Finally, a radar network for Korean Peninsula was proposed.

• The Journal of Engineering Geology
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• v.32 no.2
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• pp.281-293
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• 2022

Time series analysis was performed on data from 2009 to 2018 from the Chuncheon groundwater observation network to understand the characteristics of groundwater level fluctuations in the network. There are five observatories, all of which are installed in rock aquifers, and periodic inspections and management are performed by the relevant operating organization. Auto-correlation, spectral density, and cross-correlation analysis was performed.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.33 no.2
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• pp.103-110
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• 2015

This paper planned for the adjustment of unified control points by compared adjusted software for integrated network and the national integrated network. There may be some errors in the survey date and interpretation of data processing due to applying different software each year. To minimize errors, we performed a precision network adjustment by consolidating control points per observation session over years. Prior to perform the integrated network adjustment with the GPS analysis program (GLOBK) for the final integrated network adjustment, the Quasi-Observation Combination Analysis(QOCA), the Global Kalman filter VLBI and the GLOBK were compared and analyzed to perform an integrated network adjustment. The integrated network adjustment result indicates that the RMSE was rather big with ±0.03m along the vertical axis, but ±0.006m along the horizontal, that is not much different from the existing result.

• Journal of the Korean Institute of Telematics and Electronics C
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• v.35C no.11
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• pp.89-98
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• 1998

The enhanced resource-allocating network(ERAN) that adaptively generates hidden units of radial basis function(RBF) network for systems modeling has been proposed. The ERAN is an improved version of the resource-allocating network(RAN) that allocates new hidden units based on the novelty of observation data. The learning process of the ERAN involves allocation of new hidden units and adjusting the network parameters. The network starts with no hidden units. As observation data are received, the network adds a hidden units only if the three network growth criteria are satisfied. The network parameters are adjusted by the LMS algorithm. The performance of the ERAN is compared with the RAN for nonlinear static systems modeling problem with sequential and random learning. For two simulations, the ERAN has been shown to realize RBF networks with better accuracy with fewer hidden units.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.23 no.9
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• pp.1139-1145
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• 2019

In order to efficiently use defined satellite network resources, it is a priority to understand the performance and usage of the network. In this paper, in order to analyze the operational efficiency and stability of the system in the satellite communication system operated by K-water flood forecast and alarm network, FTP and ping testing and network traffic analysis methods of measuring download and upload speed between central and observational countries were introduced. As a result of measuring the transmission speed by the introduced test method, the effects of TCP accelerators have been improved by 120% upon download from the observational station. Through the performance test and traffic analysis of the satellite hydrologic observation system introduced, environmental improvement and improvement points of the satellite communication system were derived so that the operational efficiency and stability of the communication network could be expected.

• Journal of Korean Society for Geospatial Information Science
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• v.14 no.1 s.35
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• pp.65-74
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• 2006

A rapidly developed satellite technology is used in comprehensive fields such as spatial data aquisition and applications. Especially a GPS positioning is expected to reinvigorate at the national reference system changes to ITRF(International Terrain Reference Frame). Currently the National Geographic Information Institute(NGII) issues a triangulation point coordinate by separating old and new coordinates and in the year of 2007 it will be scheduled to be changed ITRF. The triangulation point coordinate in Cheju area causes some problems due to the difference original observation and re-observation. Thus in this study a GPS observation is conducted after re-organizing geodetic network based on 1st and 2nd order triangulation in order to check the current triangulation points in Cheju area. After the GPS observation data analysis, stable points were extracted, proposed a geodetic network and its application.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• v.1
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• pp.151-156
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• 2006

Accurate vessel traffic observation is indispensable to carry out vessel traffic management, design of vessel traffic route, planning of port construction, etc. In order to observe the vessel traffic accurately without many efforts such as the use of a ship or car equipped with special radar observation system and the preparation of observation staff, the authors have been developing completely automated remote radar/AIS network system covering the main traffic area in Tokyo Bay. The composite radar image observed at Yokosuka and Kawasaki radar stations with AIS information can be seen on web site of Internet. In addition to the development of radar/AIS observation system, the software to analyze observed vessel traffic flow has been developed. This software has various functions such as automatic tracking of ship's positions, automatic estimation of ship's size, automatic integration of radar image and AIS data, animation of ships' movements, extraction of dangerous ship encounters, etc. The configuration and functions of the developed remote radar/AIS network system are shown first in this paper. Then various functions of the software to analyze vessel traffic are introduced, and some analyzed results on the vessel traffic in Tokyo Bay are described demonstrating the effectiveness of the developed system.

• Proceedings of the KSRS Conference
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• 2003.11a
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• pp.955-958
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• 2003

Nepal is a country of mountains The higher order geodetic points were mostly established on the top of mountains and these points were used for the geodetic network extension. Lower order geodetic control networks were established at different times and used for the surveying and mapping activities of the country.. It has been found that the rate of convergence between north and south borders of Nepal to be 21${\pm}$2 mm each year and the rate translation of Kathmandu to 55${\pm}$3 mm/year to the plates. The most intense deformation in Nepal occurs along the belt of high mountains along its northern border res ulting in a strain contraction rate normal to the Himalayan Arc. This belt is approximately 40 km wide and extends into southern Tibet.( 13). Recently Survey Department of Nepal has lunched a program of strengthening the existing geodetic network of Nepal and re-observed the position of higher order geodetic points by using geodetic GPS receivers to evaluate their position and thus to define the precision of the control points once again. This paper describes the observation procedure and the adjustment results of the existing higher order control network of Nepal established in different time using different types of equipment and techniques; and highlights the observation procedure and the result obtained after the post processing of the GPS observation results. Attempt has been made to give the procedure and identify the methodology for the re observation of existing higher order geodetic points by using GPS receiver and post processing the observed data so that the existing higher order geodetic points are within the given accuracy standard.

• The Bulletin of The Korean Astronomical Society
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• v.34 no.1
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• pp.185.2-185.2
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• 2009

• Publications of The Korean Astronomical Society
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• v.22 no.4
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• pp.189-199
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• 2007

In this paper, we describe the proposed KVN (Korean VLBI Network) clock system in order to make the observation of the VLBI effectively. In general, the GPS system is widely used for the time information in the single dish observation. In the case of VLBI observation, a very high precise frequency standard is needed to perform the observation in accordance with the observation frequency using the radio telescope with over 100km distance. The objective of the high precise clock system is to insert the time-tagging information to the observed data and to synchronize it with the same clock in overall equipments which used in station. The AHM (Active Hydrogen Maser) and clock system are basically used as a frequency standard equipments at VLBI station. This system is also adopted in KVN. The proposed KVN clock system at each station consists of the AHM, GPS time comparator, standard clock system, time distributor, and frequency standard distributor. The basic experiments were performed to check the AHM system specification and to verify the effectiveness of implemented KVN clock system. In this paper, we briefly introduce the KVN clock system configuration and experimental results.