• The Bulletin of The Korean Astronomical Society
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• v.43 no.1
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• pp.34.2-35
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• 2018

Galaxy transition from star-forming to quiescent, accompanied with morphology transformation, is one of the key unresolved issues in extragalactic astronomy. Although several environmental mechanisms have been proposed, a deeper understanding of the impact of environment on galaxy transition still requires much exploration. My Ph.D. thesis focuses on which environmental mechanisms are primarily responsible for galaxy transition in different environments and looks at what happens during the transition phase using multi-wavelength photometric/spectroscopic data, from UV to mid-infrared (MIR), derived from several large surveys (GALEX, SDSS, and WISE) and our GMOS-North IFU observations. Our multi-wavelength approach provides new insights into the *late* stages of galaxy transition with a definition of the MIR green valley different from the optical green valley. I will present highlights from three areas in my thesis. First, through an in-depth study of environmental dependence of various properties of galaxies in a nearby supercluster A2199 (Lee et al. 2015), we found that the star formation of galaxies is quenched before the galaxies enter the MIR green valley, which is driven mainly by strangulation. Then, the morphological transformation from late- to early-type galaxies occurs in the MIR green valley. The main environmental mechanisms for the morphological transformation are galaxy-galaxy mergers and interactions that are likely to happen in high-density regions such as galaxy groups/clusters. After the transformation, early-type MIR green valley galaxies keep the memory of their last star formation for several Gyr until they move on to the next stage for completely quiescent galaxies. Second, compact groups (CGs) of galaxies are the most favorable environments for galaxy interactions. We studied MIR properties of galaxies in CGs and their environmental dependence (Lee et al. 2017), using a sample of 670 CGs identified using a friends-of-friends algorithms. We found that MIR [3.4]-[12] colors of CG galaxies are, on average, bluer than those of cluster galaxies. As CGs are located in denser regions, they tend to have larger early-type galaxy fractions and bluer MIR color galaxies. These trends can also be seen for neighboring galaxies around CGs. However, CG members always have larger early-type fractions and bluer MIR colors than their neighboring galaxies. These results suggest that galaxy evolution is faster in CGs than in other environments and that CGs are likely to be the best place for pre-processing. Third, post-starburst galaxies (PSBs) are an ideal laboratory to investigate the details of the transition phase. Their spectra reveal a phase of vigorous star formation activity, which is abruptly ended within the last 1 Gyr. Numerical simulations predict that the starburst, and thus the current A-type stellar population, should be localized within the galaxy's center (< kpc). Yet our GMOS IFU observations show otherwise; all five PSBs in our sample have Hdelta absorption line profiles that extend well beyond the central kpc. Most interestingly, we found a negative correlation between the Hdelta gradient slopes and the fractions of the stellar mass produced during the starburst, suggesting that stronger starbursts are more centrally-concentrated. I will discuss the results in relation with the origin of PSBs.

• The Bulletin of The Korean Astronomical Society
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• v.43 no.1
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• pp.59.4-60
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• 2018

To investigate the impact of the high-redshift quasars on cosmic reionization, the faint end slope of the quasars luminosity function has to be determined precisely. More quasars with low luminosity are needed to constrain the contribution to reionization in the early universe. However, finding these quasars has been regarded as tough process owing to the improper shallow depth of imaging data. In recent days, the release data of Subaru Hyper Suprime-Cam (HSC) Strategic Program survey which provide the deep images reaching ~ 25 mag facilitates searching the faint quasars candidates. To find faint quasar candidates in ELAIS-N1 field, along with the HSC data, two near-infrared (NIR) data sets also be used : The Infrared Medium-deep Survey (IMS) and The UKIRT Infrared Deep Sky Survey (UKIDSS) - Deep Extragalactic Survey (DXS). Quasar candidates selected from the multi-band color cut were observed by the SED camera for QUasars in EArly uNiverse (SQUEAN) instrument. To trace the redshifted Lyman break efficiently, appropriate medium bands comparable to targeted redshift range are chosen. The most reliable quasar candidates are finally determined through SED fitting. Using this less luminous quasars candidates, we can speculate the relation between the quasar growth and the host galaxy unbiasedly and estimate the contribution to the cosmic reionization.

• Journal of the Korean Society of Costume
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• v.62 no.8
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• pp.1-18
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• 2012

The purpose of the study was to offer in-depth understanding of the women's wear research trend in South Korea and thus to provide insights from the findings throughout the study to set appropriate directions for further development of women's wear related researches in the clothing and textile study area. The study considered research papers published by the 6 major apparel related journals listed on the KCI(Korea Citation Index) i.e. journals of the Korean Society of Clothing and Textiles(KSCT), the Korean Society of Costume(KSC), the Costume Culture Association (CCA), the Korean Society of Fashion Business(KSFB), the Korean Home Economics Association (KHEA) and the Korean Society for Clothing Industry(KSCI). A total of 380 research papers that were related with women's wear published from 2001 to 2010 were selected for the study and analyzed in the form of descriptive statistics using the SPSS Software ver. 18.0. The analysis was categorized according to the journals, years and research theme. The research themes were divided into various categories such as, clothing construction, textile science, fashion aesthetics and design, costume history and culture, apparel psychology and fashion marketing. The results derived from the research were: (1) the ratio of the research papers on the women's wear to the total papers published from 2001 to 2010 by the 6 subject journals was 380 to 6,815, i.e. 5.6% of the total papers; (2) journal of KSCT published the most women's wear research papers (N=149, 39.2%) and then the rest in order were the journal of CCA (N=69, 18.2%), the journal of KSC (N=68, 17.9%), the journal of KSFB (N=52, 13.7%), the journal of KHEA (N=39, 10.3%) and the journal of KSCI (N=3, 0.7%); (3) the proportions of the research themes for the women's wear study were in the order of the case study in marketing (N=135, 35.5%), body measurements and sizing systems in clothing construction (N=88, 23.2%), fashion design and aesthetics (N=83, 21.8%), pattern-making (N=63, 16.6%), and color study (N=11, 2.9%) and so on.

• Conservation Science in Museum
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• v.20
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• pp.77-92
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• 2018

A stone seated bodhisattva (Sinsu5971) was discovered in Pyeongchang-gun, Gangwon-do in 1974 and was transferred to the Chuncheon National Museum upon its opening in 2002. The statue had damage to wide areas and was thus difficult to restore. This study utilized 3D scanning and 3D printing technologies to identify the overall form of the statue and the degree of damage, which allowed the restoration of lost portions that otherwise could not have been accurately restored to their original shape. Prior to the conservation treatment, the pigments used to decorate the surface were investigated using an optical microscope, and their main components were analyzed with a p-XRF (Potable X-ray Fluorescence Analyzer). The deteriorated lacquered surface was stabilized using animal glue and consolidated with stone strengthener (OH-100). The investigation found that the surface of the statue was made of zeolite that was lacquered and then gilded. As for pigments, white lead was used for the white color and red lead and cinnabar were used for red. The lost portions were redesigned by mirroring the remaining parts with 3D technologies. However, it was difficult to affix the 3D printing outputs to the statue without visible gaps since the damaged parts suffered flection. The portions of the outputs to be connected to the statue were thus modified and supplemented. It was also difficult to collect data on the properties of 3D printing materials due to the lack of previous in-depth study. These obstacles are subjects for further study.

• The KIPS Transactions:PartD
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• v.14D no.4 s.114
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• pp.447-458
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• 2007

The objective of this study is to provide faster mobile web service by improving performance of Contents Cache used for mobile web service in the existing Mobile Gate System. It was found that two elements existed in Mark-Up page transcoded by Contents Generator. One of the elements was dependent only on the requested DIDL page and Mark-Up type. The other was dependent on each of the requested DIDL page, Mark-Up type, size of mobile display 모바일 장치 to request service, type of images available and color depth count of the images available. The conventional Contents Cache saved the entire Mark-Up page to hold both of the two elements. This caused the problem where storage space was not effectively used because reusable elements were repetitively saved in cache memory domain due to change in one of the elements even though all the other elements were the same. As a result, a larger number of transcoded Mark-Up pages could not be saved in the same cache memory size. Therefore, in this study, Mark-Up pages transcoded by Contents Generator were divided into two elements and were separately saved. Also, in order to respond to the demand for replacing data in cache with new data, this study applied two algorithms of LFU and LRU. This study proposed the method to implement cache performance of faster speed by enabling to save more number of the transcoded Mark-Up pages in the same cache storage space.

• Journal of the Korea institute for structural maintenance and inspection
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• v.20 no.3
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• pp.111-121
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• 2016

In this study, measurements were conducted by image processing to do an in-depth evaluation of strain of rebar in a uniaxial tension test. The distribution of strain and the necking region were evaluated. The image processing is used to analyze the color information of a colored image, so that the parts consistent with desired targets can be distinguished from the other parts. After this process, the image was converted to a binary one. Centroids of each target region are obtained in the binary images. After repeating such process on the images from starting point to the finishing point of the test, elongation between targets is calculated based on the centroid of each target. The tensile test were conducted on grade 60 #7(D22) and #9(D29) rebars fabricated in accordance with ASTM A615 standards. Strain results from image processing were compared to the results from a conventional strain gauge, in order to see the validity of the image processing. With the image processing, the measuring was possible in not only the initial elastic region but also the necking region of more than 0.5(50%) strain. The image processing can remove the measuring limits as long as the targets can be video recorded. It also can measure strain at various spots because the targets can easily be attached and detached. Thus it is concluded that the image processing helps overcome limits in strain measuring and will be used in various ways.

• Journal of Conservation Science
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• v.27 no.4
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• pp.345-356
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• 2011

To remove metal stains of the ceramics, chemical cleaning is essential case by case. This study investigated the removal characteristics of iron stains by oxalic acid and citric acid including their application methods of soaking and poultice. The soaking method in cleaning agents showed removal process by color difference and released iron contents from iron stains on ceramics. Iron stains were removed successfully from ceramics, which soaked in oxalic acid for 60 hours. However, it is recommendable to soak in 0.25M oxalic acid for one to three hours because most iron stains were disappeared in 3 hours soaking. Citric acid is less effective than oxalic acid in removing iron stains because of heavy molecular weight and low acidity. Poultices (bentonite, sepiolite, activated carbon fiber and celite) with oxalic acid were applied on contaminated ceramics. After ten hours, iron stains on ceramics were removed successfully by poultice. Among them, bentonite and sepiolite have better application. Therefore, sepiolite with 0.25M oxalic acid was applied on the iron stains of whiteware and celadon from Ma Island, and then stains were removed. However, it is judged that the application methods can be varied according to the form and depth of contaminant. In addition, the residues of poultice on the ceramics will be considered for preventing contamination.

• Journal of the Mineralogical Society of Korea
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• v.24 no.3
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• pp.179-188
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• 2011

In order to investigate absolute age of marine sediment in the KR5 region, northeastern Pacific, we measured the Be isotope ($^{10}Be$ and $^{9}Be$) of box core (BC08-02-13) sediment with depth. Core sediment is divided into three sedimentary facies (Facies I, Facies II, FaciesIII). Facies I mainly consists of brown to dark brown (10YR4/3) homogeneous mud with high water content. Facies II shows brownish yellow (10YR6/6) color. The unconformity is recognized at the boundary between Facies I and Facies II, Facies III consists of very dark brown (10YR2/2) mud. Many bioturbated burrows are observed at FaciesII and FaciesIII. Based on Be dating results, FaciesIII and Facies II had been deposited before 3.7 Ma and 2.3 Ma, respectively. After 2.3 Ma, the upper part of Facies II was eroded due to the change of sedimenary environment. Facies I has been deposited since 1.8 Ma. The unconformity located at the boundary between Facies I and Facies II may be driven by the envrionmental change due to the migration of Intertropical Convergence Zone.

• Journal of Internet Computing and Services
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• v.18 no.6
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• pp.85-92
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• 2017

Recently, in the field of video surveillance, a Deep Learning based learning method has been applied to a method of detecting a moving person in a video and analyzing the behavior of a detected person. The human activity recognition, which is one of the fields this intelligent image analysis technology, detects the object and goes through the process of detecting the body keypoint to recognize the behavior of the detected object. In this paper, we propose a method for Body Keypoint Localization based on Object Detection using RGB-D information. First, the moving object is segmented and detected from the background using color information and depth information generated by the two cameras. The input image generated by rescaling the detected object region using RGB-D information is applied to Convolutional Pose Machines for one person's pose estimation. CPM are used to generate Belief Maps for 14 body parts per person and to detect body keypoints based on Belief Maps. This method provides an accurate region for objects to detect keypoints an can be extended from single Body Keypoint Localization to multiple Body Keypoint Localization through the integration of individual Body Keypoint Localization. In the future, it is possible to generate a model for human pose estimation using the detected keypoints and contribute to the field of human activity recognition.

• Journal of Digital Contents Society
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• v.17 no.1
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• pp.23-31
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• 2016

This study aims to develop a stereoscopic image authoring tool to effectively produce e-Book content that enhances user's sense of immersion in 3D environments. The proposed authoring tool consists of three core systems; 3D object editing, stereoscopic image, and image media production systems. First, the object editing system arranges and produces diverse objects that constitute virtual 3D spaces to fit the purpose of the content. In this case, commercial graphic authoring tools are utilized to design efficient data structures that can include produced external models. In addition, the material and textures of objects are made to be revisable and editable into the form wanted by the user. Thereafter, a stereoscopic image system will be implemented to produce the generated virtual scenes into stereoscopic images. This study uses the Anaglyph method so that the user can implement and use stereoscopic image scenes more easily. This method include functions to change the color of stereo cameras and control depth scaling. Finally, an image media production system will be implemented that will enable producing the produced stereoscopic images into single images or videos so that they can be effectively utilized in e-Book content.