• The Bulletin of The Korean Astronomical Society
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• v.35 no.1
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• pp.28.1-28.1
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• 2010

Ground-based solar observations have several merits such as wider field of view and higher time cadence than those of satellite observations. The Domeless Solar Telescope of Hida Observatory is designed to acquire solar surface images at the highest possible spatial resolution using two types of spectrographs: a vertical spectrograph with the highest wavelength resolution in the world, and a horizontal spectrograph that can take images of the sun in multi-wavelength over the entire visible solar spectrum. The temporal variation of fine features such as chromospheric grains in the supergranulation cells and facular points in the network region has been obtained using DST Ca II K lines compared with Hinode Ca II H lines. This analysis is expected to provide a fundamental tool for research of diverse phenomena on the solar surface.

• Proceedings of the KSRS Conference
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• 2007.10a
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• pp.422-425
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• 2007

Traditionally, surface energy fluxes are obtained by model simulations or empirical equations with auxiliary meteorological data. These methods may not effectively represent the surface heat fluxes in a regional scale due to scene variability. On the other hand, remote sensing has the advantage to acquire data of a large area in an instantaneous view. The remotely sensed data can be further used to retrieve surface radiation and heat fluxes over a large area. In this study, the airborne and satellite images in conjunction with meteorological data and ground observations were used to estimate the surface heat fluxes over Taiwan's Chaiyi Plain. The results indicate that surface heat fluxes can be properly determined from both airborne and satellite images. The correlation coefficient of surface heat fluxes with in situ corresponding observations is over 0.60. We also observe that the remotely sensed data can efficiently provide a long term monitoring of surface heat fluxes over Taiwan's Chaiyi Plain.

• Korean Institute of Interior Design Journal
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• v.16 no.6
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• pp.172-180
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• 2007

As library have become changed. Beyond conventional simple functions such as data storing and recording, the functions of modern public libraries are expended to various directions, for example functions of encouraging residents to utilize information and participate in cultural activities and also a function of life-long education, resulting in playing a role as complex space. As the role of public libraries changes into a complex one, spatial planning reflecting this change is required. Spatial arrangements, furniture arrangements and interior images in 12 public libraries in Seoul were analyzed. As a result of the study, it was found that in spatial arrangements, many public libraries linked spaces by functions. Furniture arrangements have been changing from the closed arrangement to the open arrangement. Interior images were identified as static and simple except digital information space. Accordingly, public libraries have became needed to play a proper role of community facilities for local residents by planning furniture arrangements and conducting interior designs taking characteristics of many different users into consideration.

• Proceedings of the KSRS Conference
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• 2003.11a
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• pp.687-689
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• 2003

High resolution satellite images have huge amount of pixels in common. Thus, an efficient method is required for the generation of orthoimages. Patch backprojection method is a feasible way to improve the efficiency with respect to the point-by-point patch backprojection. We will propose an Adaptive Patch that optimizes the patch size for different terrain variations. The essence of the patch optimization is quadrate structuring for terrain variations. The area of interest is, thus, sequentially subdivided to four quadrate tiles until a preset criterion is met. The experiment results indicated that the proposed method is efficient without losing accuracy.

• The Bulletin of The Korean Astronomical Society
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• v.44 no.1
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• pp.61.4-61.4
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• 2019

The key science goal of the KMTNet Supernova Program (KSP) is to detect and study the early explosions of supernovae using one fifth of the KMTNet time. The BVI-band observations of the nearby target fields mostly closer than 30 Mpc distance and the follow-up spectroscopy provide valuable information on the early phase of the supernovae. These data can also be used for the studies of optical transients such as novae, dwarf novae, variable stars, and active galactic nuclei. Stacked images of several hundred images obtained from the time domain observations can be used for the search of low surface brightness galaxies reaching $28mag\;arcsec^{-2}$. Results and status of the KSP including ${\geq}20$ infant supernovae and ${\geq}100$ faint dwarf galaxies will be presented in this talk.

• The Bulletin of The Korean Astronomical Society
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• v.35 no.2
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• pp.62.1-62.1
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• 2010

CQUEAN (Camera for QUasars in EArly uNiverse) is an optical CCD camera system that consists of a science CCD camera, a guide CCD camera, and seven filters. In addition, a focal reducer is installed in front of the science camera to secure a larger field of view for the system. Engineering run of the system was carried out from Aug. 10, 2010 to Aug. 17, 2010, with 2.1m Otto Struve telescope at McDonald Observatory, USA, from which we investigated the characteristics and performance of the system. Bias and dark images were taken under various temperature conditions to examine the system behavior, and both twilight and dome flat images were obtained to investigate the appropriate preprocessing procedures of the data. Crude initial estimate indicated one hour integration would reach limiting magnitude of 24.2 in i-band with S/N ratio of 5, with CQUEAN at 2.1m telescope. The detailed results of the engineering run will be presented.

• Journal of the Korea Society of Computer and Information
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• v.21 no.6
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• pp.21-28
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• 2016

Circle detection has long been studied as one of fundamental image processing applications. It is used in divers areas including industrial inspection, medial image analysis, radio astronomy data analysis, and other object recognition applications. The most widely used class of circle detection techniques is the circle Hough transform and its variants. Management of 3 dimensional parameter histogram used in these methods brings about spatial and temporal overheads, and a lot of studies have dealt the problem. This paper proposes a robust circle detection method using maximal symmetry property of circle. The basic idea is that if perpendicular bisectors of pairs of edges are accumulated in image space, center of circle is determined to be the location of highest accumulation. However, directly implementing the idea in image space requires a lot of calculations. The method of this paper reduces the number of calculations by mapping the perpendicular bisectors into parameter space, selecting small number of parameters, and mapping them inversely into image space. Test on 22 images shows the calculations of the proposed method is 0.056% calculations of the basic idea. The test images include simple circles, multiple circles with various sizes, concentric circles, and partially occluded circles. The proposed method detected circles in various situations successfully.

• Journal of Broadcast Engineering
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• v.27 no.7
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• pp.999-1010
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• 2022

The increase in vehicle purchases worldwide is having a very significant impact on the availability of parking spaces. In particular, since it is difficult to secure a parking space in an urban area, it may be of great help to the driver to check vehicle parking information in advance. However, the current parking lot information is still operated semi-manually, such as notifications. Therefore, in this study, we propose a system for detecting a parking space using a relatively simple image processing method based on an image taken from the sky and evaluate its performance. The proposed method first converts the captured RGB image into a black-and-white binary image. This is to simplify the calculation for detection using discrete information. Next, a morphological operation is applied to increase the clarity of the binary image, and a template mask in the form of a bounding box indicating a parking space is applied to check the parking state. Twelve image samples and 2181 total of test, were used for the experiment, and a threshold of 40% was used to detect each parking space. The experimental results showed that information on the availability of parking spaces for parking users was provided with an accuracy of 95%. Although the number of experimental images is somewhat insufficient to address the generality of accuracy, it is possible to confirm the possibility of parking space detection with a simple image processing method.

• The Bulletin of The Korean Astronomical Society
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• v.44 no.2
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• pp.70.4-70.4
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• 2019

Image super-resolution (SR) is a technique that enhances the resolution of a low resolution image. In this study, we use three SR models (RCAN, ProSRGAN and Bicubic) for enhancing solar SDO/HMI magnetograms using deep learning. Each model generates a high resolution HMI image from a low resolution HMI image (4 by 4 binning). The pixel resolution of HMI is about 0.504 arcsec. Deep learning networks try to find the hidden equation between low resolution image and high resolution image from given input and the corresponding output image. In this study, we trained three models with HMI images in 2014 and test them with HMI images in 2015. We find that the RCAN model achieves higher quality results than the other two methods in view of both visual aspects and metrics: 31.40 peak signal-to-noise ratio(PSNR), Correlation Coefficient (0.96), Root mean square error (RMSE) is 0.004. This result is also much better than the conventional bi-cubic interpolation. We apply this model to a full-resolution SDO/HMI image and compare the generated image with the corresponding Hinode NFI magnetogram. As a result, we get a very high correlation (0.92) between the generated SR magnetogram and the Hinode one.

• Journal of the Korean Institute of Landscape Architecture
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• v.44 no.4
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• pp.75-85
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• 2016

In recent years, natural healing space studies have been done in health care and forestry. However, previous studies have focused on healing effects of natural elements in interior space or natural landscape view. And there is a limit to using the evidence for healing space design. The aim of this study is to discover the relationship between types and effects of healing space for evidence-based design. This study compares and analyzes the mayor images, psychological restorativeness, and satisfaction to identify the effects and differences of natural trail, designed trail, natural shelter, and designed shelter by types of forest space. Collected data is analyzed with a factorial analysis, valiance analysis and multiple regression analysis in SPSS 18.0. The results of this study are as follows: 1) Among five factors consisting psychological restorativeness, natural trail can be achieved with 'being away' and 'compatibility' and designed shelter can be achieved with 'fascination' and 'coherence'., 2) Psychological restorativeness values higher in images with higher excitement, brightness, vitality, and beautifulness as well as in images with lower level of disorder., 3) Among five factors consisting psychological restorativeness, higher forest satisfaction can be achieved with a higher level of 'being away' and 'coherence'. In conclusion, this study contributes to providing fundamental information for design guidelines of healing spaces through identifying the characteristics of healing environment by types of forest space.