• Journal of Korean Society of Coastal and Ocean Engineers
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• v.4 no.2
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• pp.121-129
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• 1992

A two-dimensional numerical tidal model is formulated to reproduce tides in the northeastern Yellow-Sea, Seohan Bay. The model was formulated on spherical grid system with mesh resolution of 1' latitude by 4/3' longitude. As a first step, tidal distribution of four major tidal constituents are computed and compared with coastal observation. Independent tidal charts for the M$_2$, S$_2$, $K_1$, and $O_1$ tides were presented. Residual tidal currents and tidal energy flux were also computed.

• Journal of Korea Multimedia Society
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• v.15 no.12
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• pp.1430-1441
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• 2012

In this paper, we present an algorithm that quickly and effectively estimates orthogonal vanishing points in equirectangular images of urban environment. Our algorithm is based on the RANSAC (RANdom SAmple Consensus) algorithm and on the characteristics of the line segment in the spherical panorama image of the $360^{\circ}$ longitude and $180^{\circ}$ latitude field of view. These characteristics can be used to reduce the geometric ambiguity in the line segment classification as well as to improve the robustness of vanishing point estimation. The proposed algorithm is validated experimentally on a wide set of images. The results show that our algorithm provides excellent levels of accuracy for the vanishing point estimation as well as line segment classification.

• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.2382-2386
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• 2003

The Global Positioning System(GPS) is a satellite based precise positioning system avaliable worldwide. The GPS have many error sources. The earth's ionosphere and atmosphere cause delays in the GPS signal that translate into position errors. Some errors can be factored out using mathematics and modeling. The configuration of the satellites in the sky can magnify other errors. The problem of accuracy on GPS measurement data can be meaningful. In this study, we propose the method for GPS positioning accuracy improvement. The FUZZY set theory on PDOP(Position Dilution of Precision) and SNR(Signal to Noise Ratio) provide improved for measured positioning data. The accuracy of positioning has been improved by selecting data from original using the FUZZY set theory on PDOP and SNR.

• Journal of international Conference on Electrical Machines and Systems
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• v.3 no.4
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• pp.472-480
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• 2014

The In solar power system, the height and azimuth of the sun are important parameters which control generated power magnitude. The tracking method that controls the daily generation magnitude according to latitude and longitude using the two axles is often used in the existing sunlight tracking system today. In this two-axle PV track control system, the self-load is concentrated on one FRAME. It is influenced of the regular load, snow load and the wind load, etc. It is difficult to set up the system in the conventional building. This research is a development about the small-scale economy track device of independent load-dispersing solar generation system. The position tracking algorithm is through new coordinates transformation calculating the height and azimuth of the sun.

• Journal of Astronomy and Space Sciences
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• v.32 no.4
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• pp.311-315
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• 2015

In this study, we estimated the topside scale height of plasma density (Hm) using the Swarm constellation and ionosondes in Korea. The Hm above Korean Peninsula is generally around 50 km. Statistical distributions of the topside scale height exhibited a complex dependence upon local time and season. The results were in general agreement with those of Tulasi Ram et al. (2009), who used the same method to calculate the topside scale height in a mid-latitude region. On the contrary, our results did not fully coincide with those obtained by Liu et al. (2007), who used electron density profiles from Arecibo Incoherent Scatter Radar (ISR) between 1966 and 2002. The disagreement may result from the limitations in our approximation method and data coverage used for estimations, as well as the inherent dependence of Hm on Geographic LONgitude (GLON).

• The Korean Journal of Ecology
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• v.20 no.6
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• pp.423-438
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• 1997

The structure and variation of the mating call in Rana nigromaculata was studied in a population at Da-rak, Chong-won, Chung-buk (36$\circ$ 37' latitude, 127$\circ$ 21' longitude) in Korea. The mating call consists of 3 to 8 pulse groups divided by clear silent intervals. Each pulse group is also composed of fine pulses. Temperature and body size affect the temporal and spectral characteristics of the mating call. Pulse, pulse group repetition rate and dominant frequency rise with increasing temperature, whereas pulse grouprepetition rate and dominant frequency decrease with increasing body size. A playback experiment was designed to establish the effect of a potential intruder on male calling. During the stimulus periods, resident males markedly decreased the pulse repetition rate, and icreased the rate of pulse groups, dominant frequency, and the number of call groups. This results indicate that this species responds in a graded fashion when interacting with other individuals.

• Journal of The Korean Astronomical Society
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• v.46 no.4
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• pp.151-159
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• 2013

We discuss the orbital period changes of the Algol semi-detached eclipsing binary DI Peg by constructing the (O-C) residual diagram via using all the available precise minima times. We conclude that the period variation can be explained by a sine-like variation due to the presence of a third body orbiting the binary, together with a long-term orbital period increase (dP/dt=0.17 sec/century) that can be interpreted to be due to mass transfer from the evolved secondary component (of rate $1.52{\times}10^{-8}M_{\odot}/yr$) to the primary one. The detected low-mass third body ($M_{3min.}=0.22{\pm}0.0006M_{\odot}$) is responsible for a periodic variation of about 55 years light time effect. We have determined the orbital parameters of the third component which show a considerable eccentricity $e_3=0.77{\pm}0.07$ together with a longitude of periastron ${\omega}_3=300^{\circ}{\pm}10^{\circ}$.

• ETRI Journal
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• v.30 no.6
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• pp.774-782
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• 2008

An operational orbit determination (OD) and prediction system for the geostationary Communication, Ocean, and Meteorological Satellite (COMS) mission requires accurate satellite positioning knowledge to accomplish image navigation registration on the ground. Ranging and tracking data from a single ground station is used for COMS OD in normal operation. However, the orbital longitude of the COMS is so close to that of satellite tracking sites that geometric singularity affects observability. A method to solve the azimuth bias of a single station in singularity is to periodically apply an estimated azimuth bias using the ranging and tracking data of two stations. Velocity increments of a wheel off-loading maneuver which is performed twice a day are fixed by planned values without considering maneuver efficiency during OD. Using only single-station data with the correction of the azimuth bias, OD can achieve three-sigma position accuracy on the order of 1.5 km root-sum-square.

• Journal of the Korean Society of Costume
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• v.50 no.5
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• pp.159-169
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• 2000

The purpose of this study Is to research the clothing and textiles recorded in Heikemonokatary which was written from 1131 to 1198. The research materials are 36 kinds of men's clothes and ornaments, 6 kinds of women's things, 10 kinds of colorings and 6 kinds of textiles. The results of this study are as follow : 1. There were many advanced warriors' clothes. Especially the helmets and armors were very gorgeous. The shapes of warriors' knives, arrows, shields were concretely described. The women's clothes were mostly unchanged from Nara period and Heian period. Women wore clothes on their heads when they went out. 2. One particular thing in color is that the brown color of that period was navy blue which is symbolic of victory. There were some textiles which was woven with the boiled silk thread in the latitude and the raw silk thread in the longitude. Besides, the blackening of teeth, the bobbed haler of boys, and the celebration of one's corning of age were described in the book.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.5 no.1
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• pp.1-12
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• 1987

Using double-measurmented gravity values which observed by Lacoste instrument, drifts and MSE are analized after TIDE correction and Bouguer reduction is investigation. As the result of this study, it is possible to calculation a latitude, longitude, gravity and elevation at unknown point, and perphaps will be used as a fundamental data for application in the earth's crust structural analysis and geophysics.