• 한국지구과학회:학술대회논문집
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• 2005.09a
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• pp.124-131
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• 2005

A GDS (Geomagnetic Depth Sounding) method, one of extremely low-frequency EM methods, has been carried out to examine deep geo-electrical structures of the Korean peninsula. In this study, five additive GDS sites acquired in south-eastern area of the Korea were integrated into twelve previous GDS results. In addition, 3-D MT modeling considering the surrounding seas of the Korean peninsula was performed to evaluate sea effect at each GDS site quantitatively. As a result, Observed real induction arrows was not explained by solely sea effect, two conductive structures that are able to explain differences between observed and calculated induction arrows, was suggested. The first conductive structure is the Imjingang Belt, which is thought as a extension of Quiling-Dabie-sulu continental collision belt. The effects of the Imjingang Belt clearly appear at YIN and ICHN sites. The second one is the HCL (Highly Conductive Layer), which is considered as a conductive anomaly by mantle upwelling generated in back-basin region. The effects of the HCL are also confirmed at KZU, KMT101, 107 sites, in the south-eastern of the Korean peninsula.

• Economic and Environmental Geology
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• v.14 no.3
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• pp.193-201
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• 1981

The problem of automatic inversion of apparent resistivity sounding curves resulting from horizontally layered earth models is solved using the least-squares technique. This method, which makes use of damped least-squares algorithm in conjunction with digital filtering technique, is found to be speedier and more accurate than the conventional curve-matching method. Four sounding curves were chosen to test the inversion scheme. The analysis of the theoretical sounding data associated with a three-layer model illustrates clear advantages over the conventional curve-matching method. The usefulness of the inversion method is also shown when applied to the actual field data. It was found that the best fit earth models coincide with the subsurface structures confirmed by drilling.

• Journal of Satellite, Information and Communications
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• v.8 no.3
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• pp.1-5
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• 2013

In this paper, we present a conversion algorithm of the oblique ionogram obtained from Jeju and Icheon to the equivalent vertical ionogram of the path mid-point, based on some equivalence theorems between the vertical sounding and the oblique sounding for the ionosphere. And in order to verify the conversion algorithm under the condition of no vertical ionosonde at the mid-point on the test path, the equivalent vertical ionograms are compared to the real vertical ionograms measured adjacently in space-time. The comparison results show that the conversion algorithm performs well for the short-path oblique ionogram and the equivalent vertical ionograms could be applied to get the electron density profiles at the mid-point.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2011.06a
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• pp.34-36
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• 2011

ENCs is edited based on the numerical charts for publishing paper charts and serviced in forms of grid styles. For this reason, the density of sounding information of ENCs is not consistent and was required for improvement. In this study, K-Means, ISODATA clustering algorithm as classification methods for satellite image was reviewed and adopted to case study. The developed results include loading module of ENC data, improvement algorithm of sounding information, writing module of ENC data. According to the results of algorithm, we could confirm the improved result.

• Journal of Korean Society for Geospatial Information Science
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• v.10 no.1 s.19
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• pp.27-35
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• 2002

The dam made reservoir, a major means to overcome the problems caused by water resource's uneven supply by time and space, plays an important role, particularly, of water supply. The role of water supply will get more important, considering the usage of water resource becomes more intensive. Therefore, it is continuously required to construct new dams securing water supply and to study on effective operation plans of the dam. The size of reservoir needs to be measured according to possible supply estimation in the pre-design stage. The depth of water, at this point, should be taken. Among many ways of sounding, echo sounding has been frequently used recently. This study, therefore, presents a new way of sounding that takes less time with stronger accuracy, uniting GPS and echo sounder to apply a means of obtaining three dimensional position data. This enables the designer to escape from the conventional way of sounding in the estimation of reservoir to design and redesign a new dam.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.32 no.3
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• pp.88-94
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• 2004

The KSR-III rocket is a liquid propellant sounding rocket and thrust vector control actuators and cold gas thrusters are used to control pitch and yaw, roll attitude respectively during thrusting phase. In this paper, the structure of designed attitude controller and gain scheduling, results of stability analysis for KSR-III rocket are presented. The attitude controller is implemented with flight software in the domestically developed INS and successfully performed its function in the flight test. The flight data are coincident with simulation results.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.31 no.2
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• pp.80-88
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• 2003

This paper describes the development of an ozone detector and an electron probe as parts of scientific payloads for sounding rockets such as the KSR-III. Each detector consists of sensor parts and electronic parts. We successfully carried out the calibration tests with developed ozone detector and the space plasma simulation chamber tests with electron detector. These payloads could be onboard the KSR-III and with measured data, it is expected and temperature profile over the Korean Peninsular.

• Journal of the Korean Geophysical Society
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• v.5 no.3
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• pp.219-231
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• 2002

Single beam echo sounding was used to delineate bathymetry sea bottom in the area of hydrography and marine navigation. This research was aimed at measuring the thickness of floating silty clay sediment with dual frequencies echo sounding system. There occur discrepancies in penetrating depth through sea beds between high frequency(200 KHz) and low(33 KHz) frequency. RI density logging was employed to characterize the floating silty clay sediment of Guangyang bay, which was chosen to investigate the proposed site for reclamation field. The volume of floating silty clay sediment was used to design by estimating size of reclamation site. The estimation strategies developed in this study will be readily applicable to measure the Pattern of sedimentation via regular hydrographic survey in the future.

• Atmosphere
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• v.13 no.4
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• pp.71-79
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• 2003

We present a pre processing system for the Atmospheric Infrared Sounder (AIRS) sounding suite onboard Aqua satellite. With its unprecedented 2378 channels in IR bands, AIRS aims at achieving the sounding accuracy [s1]of a radiosonde (1 K in 1-km layer for temperature and 10% in 2-km layer for humidity). The core of the pre p rocessor is the International MODIS/AIRS Processing Package (IMAPP) that performs the geometric and radiometric correction to compute the Earth's radiance. Then we remove spurious data and retrieve the brightness temperature (Tb). Since we process the direct-broadcast data almost for the first time among the AIRS directbroadcast community, special attention is needed to understand and verify the products. This includes the pixel-to-pixel verification of the direct-broadcast product with reference to the fullorbit product, which shows the difference of less than $10^{-3}$ K in IR Tb.

• Journal of Biosystems Engineering
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• v.14 no.4
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• pp.251-261
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• 1989

The amount of grain loss incurred during harvesting operation through the chaff-outlet of combine may not be negligible. To minimize this grain loss and optimize condition of combining, it may be necessary that the amount of chaff-outlet loss dependent on varying crop condition is to be estimated as exactly as possible. This study was thus intended to develop the monitor that could indicate the amount of grain loss occurred through the chaff-outlet of combine during harvesting operation. The function of this monitor is to measure at the sounding board the impact sound of paddy kernels which could be distinguished from those of other threshing products through chaff-outlet, and from vibration or noise created by the combine engine and other moving parts. To develop such monitor, the frequency distributions of each sound generated by the impact of grain and chaff, the sound generated by the impact of the mixture of grain and chaff, and vibration or noise created by the combine engine and other moving parts were investigated experimentally. From the results of frequency analyses, the trainsducer adequate for the monitering system was selected and sounding board was constructed. The grain loss monitor thus obtained was tested by attaching the sounding board to the chaff-outlet of combine.