• Journal of the Korean Solar Energy Society
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• v.26 no.3
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• pp.45-51
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• 2006

Recently, various kinds of daylight system are recognized as an important and useful strategy in energy-efficient building designs. However, a large amount of direct sunlight can make many problems. Therefore, it is necessary to control daylighting through louver systems for high quality visual environment. The purpose of this study is to analyze daylighting performance in the reading room of a library according to different azimuths and louver systems. The results evaluated daylight performance based on the RADIANCE lighting software.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.38A no.9
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• pp.782-791
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• 2013

This paper proposes the location estimation techniques of distributed targets with the multi-sensor data perceived through IR sensors of the military robots. In order to match up targets with measured azimuths, we apply the maximum likelihood (ML), depth-first, and breadth-first tree search algorithms, in which we use the measured azimuths and the number of pixels on IR screen for pruning branches and selecting candidates. After matching up targets with azimuths, we estimate the coordinate of each target by obtaining the intersection point of the azimuths with the least square error (LSE) algorithm. The experimental results show the probability of missing target, mean of the number of calculating nodes, and mean error of the estimated coordinates of the proposed algorithms.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.38C no.12
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• pp.1207-1215
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• 2013

This paper proposes the location estimation techniques of distributed targets with the multi-sensor data perceived through IR sensors of the military robots in consideration of obstacles. In order to match up targets with measured azimuths, to add to the depth-first search (DFS) algorithms in free-obstacle environment, we suggest the expanded DFS (EDS) algorithm including bypass path search, partial path search, middle level ending, and the supplementation of decision metric. After matching up targets with azimuths, we estimate the coordinate of each target by obtaining the intersection point of the azimuths with the least square error (LSE) algorithm. The experimental results show the error rate of estimated location, mean number of calculating nodes, and mean distance between real coordinates and estimated coordinates of the proposed algorithms.

• Proceedings of the Optical Society of Korea Conference
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• 2001.02a
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• pp.256-259
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• 2001

Rotating-compensator type ellipsometer was developed for spectroscopic measurements. For accurate data reduction, the azimuths of transmission axises of polarizer and analyzer, and the angular position of the fast axis of compensator should be determined through calibration process. In this paper, we present various calibration methods.

• 한국지구물리탐사학회:학술대회논문집
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• 2008.10a
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• pp.155-165
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• 2008

A method to determine the azimuth of a baseline by using the measured apparent directions of the Sun, the measurement time and the latitude and the longitude of the survey point. Comparing the azimuths determined by this method and those determined by the PDGPS(Post Processed Differential GPS) on 3 different baselines, the differences (this method - PDGPS) between the azimuths determined by two methods were -13", +45" and +24" respectively. This method can be used as an effective and rapid tool in cases that require the accuracy lower than 1 arc-min.

• Geophysics and Geophysical Exploration
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• v.18 no.2
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• pp.64-73
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• 2015

Recently, hydraulic fracturing is used in various fields and microseismic monitoring is one of the best methods for judging where hydraulic fractures exist and how they are developing. When locating microseismic events using single vertical well data, distances from the vertical array and depths from the surface are generally decided using time differences between compressional (P) wave and shear (S) wave arrivals and azimuths are calculated using P wave hodogram analysis. However, in field data, it is sometimes hard to acquire P wave data which has smaller amplitude than S wave because microseismic data often have very low signal to noise (S/N) ratio. To overcome this problem, in this study, we developed a grid search algorithm which can find event location using all combinations of arrival times recorded at receivers. In addition, we introduced and analyzed the method which calculates azimuths using S wave. The tests of synthetic data show the inversion method using all combinations of arrival times and receivers can locate events without considering the origin time even using only single phase. In addition, the method can locate events with higher accuracy and has lower sensitivity on first arrival picking errors than conventional method. The method which calculates azimuths using S wave can provide reliable results when the dip between event and receiver is relatively small. However, this method shows the limitation when dip is greater than about $20^{\circ}$ in our model test.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.22 no.4
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• pp.411-418
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• 2004

This paper is the study about a method for determining the azimuth of a baseline by measuring the apparent direction of the Sun. It is simple to realize this method, as it requires, in addition to the apparent direction of the Sun already measured, the observation time and the latitude and the longitude of the survey point. Comparing the azimuths determined by this method and those determined by the PDGPS(Post Processed Differential GPS) on 3 different baselines, the differences(PDGPS - this method) between the azimuths determined by two methods were -13", +45" and +24" respectively. It can be an effective and rapid tool in cases that require the accuracy lower than 1 arc-min.than 1 arc-min.

• Korean Journal of Optics and Photonics
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• v.8 no.1
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• pp.7-13
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• 1997

This paper describes the automation of an object generator and an image analyser in a knife scan OTF equipment to enhance the accuracy of OTF measurement. Pinholes and slits of various size in the object generator are used as an objects. A fishtail edge is mounted to the image analyzer and is translated to the direction of 45 degree angle with the horizontal to measure MTF simultaneously in the radial and tangential azimuths. The stepping motor control unit and software for the image analyzer are modified and the accuracy of this equipment is evaluated by measuring the OTF of SIRA group 50 mm standard lens.

• KIEAE Journal
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• v.10 no.5
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• pp.95-100
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• 2010

Buildings receive solar radiation through windows and the solar radiation helps to save heating energy in winter. Therefore the bigger the glazing ratio is, the larger the amount of solar radiation we can receive. In this study we analysed the glazing ratio of Certified Green Building Apartments. And we verified whether the glazing ratio reflects energy saving through accepting solar radiation with correlation analysis. For glazing ratio analysis, we selected 116 apartment buildings of 19 apartment complexes that certified in 2008-2009 and took pictures of outside windows of the buildings. After that, we analysed the building's glazing ratio with 4 azimuth and checked distinction of the glazing ratio between 6 coupled azimuths. And we analysed the correlation between importance order of azimuth for energy saving and the glazing ratio change with the azimuth. The analysis showed that the glazing ratio does not reflect energy saving through accepting solar radiation.

• Journal of the Korean Institute of Navigation
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• v.6 no.2
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• pp.1-12
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• 1982

The tedious work, connected to the traditional computation of altitudes and azimuths and the plotting of the position lines, has been a severe objection to celestial fixes. But recently computers have become to be used generally for computations of altitudes and aximuths and the computing objection seems to be practically overruled. Now it seems appropriate to concentrate on other problems which are the procedure of improving accuracy of ship's position and the design of a general computing procedure to determine the coordinates of the optimally estimated ship's position. In this paper, such procedures as an application of Kalman filter and the results of the Digital simulation conducted under various noise conditiions are presented. The positions estimated by Kalman filter are compared with the running fixes and the most probable positions obtained from a single position line, and it is confirmed that the resutls of the proposed method is evidently accurate than others.