• Title/Summary/Keyword: ATLAS 9

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Determining the stellar parameters of solar-like stars using synthetic spectra

  • Kang, Won-Seok;Lee, Sang-Gak
    • The Bulletin of The Korean Astronomical Society
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    • v.36 no.2
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    • pp.151.2-151.2
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    • 2011
  • IGRINS (Immersion GRating INfrared Spectrometer) will provide the spectra with high-resolution and an instantaneous spectral coverage of H and K band in NIR region. Therefore, it is expected that the wide coverage of wavelength would make a production of an extensive NIR high-resolution spectra of standard stars as a prior program of IGRINS. As a counter part of these NIR spectra, we have planned to obtain the high-resolution spectra of those standard stars in optical band. These optical high-resolution spectra would give us an opportunity to produce the library of high-resolution stellar spectra covering from optical to NIR band, and to confirm the method to determine the stellar parameters and chemical abundances from the NIR high-resolution spectra. Before using the NIR high-resolution spectra, we have tested the method to determine the stellar parameters by comparing between the observed spectra and the synthetic spectra in optical band. In order to make the synthetic spectra, we have used the Kurucz ATLAS9 model grids and the SYNTH code described by Fiorella Castelli (http://wwwuser.oat.ts.astro.it/castelli/). For the cross-check against the parameters that would be derived from the NIR spectra, the stellar parameters such as effective temperature and surface gravity were determined using the optical spectra of the solar-like stars, as preliminary results.

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Stellar surface gravity extracted from Wilson-Bappu effect

  • Park, Sun-Kyung;Kang, Wonseok;Lee, Jeong-Eun;Lee, Sang-Gak
    • The Bulletin of The Korean Astronomical Society
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    • v.37 no.2
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    • pp.139.1-139.1
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    • 2012
  • Wilson and Bappu (1957) found a significant relationship (WBR) between the absolute magnitude ($M_v$) and the width of the Ca II K emission line (W) for late type stars. In this study, we revisit the WBR to claim that WBR can be an excellent indicator of stellar surface gravity. We analyze 95 high-resolution spectra of G, K and M type stars obtained with UVES and BOES. WBR found in this work is $M_v$=34.22-18.34logW. In addition, stellar atmospheric parameters ($T_{eff}$, logg, [Fe/H], ${\xi}_{tur}$) are determined with the MOOG code and the Kurucz ATLAS9 model grids for G and K type stars. For M type stars, the method of Belle et al. (1999) is used to derive effective temperature which shows good agreement with other methods. Using the derived $T_{eff}$ and the measured logW,we find the relationship between logg and [logW, logT]; ${\log}g-_{fit}=-25.051-5.527{\log}W+10.254{\log}T_{eff}$. This relation can be applied to estimate the surface gravity of M type stars, which is difficult to be determined by other methods.

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Molecular Cloning and Bioinformatic Analysis of SPATA4 Gene

  • Liu, Shang-Feng;Ai, Chao;Ge, Zhong-Qi;Liu, Hai-Luo;Liu, Bo-Wen;He, Shan;Wang, Zhao
    • BMB Reports
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    • v.38 no.6
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    • pp.739-747
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    • 2005
  • Full-length cDNA sequences of four novel SPATA4 genes in chimpanzee, cow, chicken and ascidian were identified by bioinformatic analysis using mouse or human SPATA4 cDNA fragment as electronic probe. All these genes have 6 exons and have similar protein molecular weight and do not localize in sex chromosome. The mouse SPATA4 sequence is identified as significantly changed in cryptorchidism, which shares no significant homology with any known protein in swissprot databases except for the homologous genes in various vertebrates. Our searching results showed that all SPATA4 proteins have a putative conserved domain DUF1042. The percentages of putative SPATA4 protein sequence identity ranging from 30% to 99%. The high similarity was also found in 1 kb promoter regions of human, mouse and rat SPATA4 gene. The similarities of the sequences upstream of SPATA4 promoter also have a high proportion. The results of searching SymAtlas (http://symatlas.gnf.org/SymAtlas/) showed that human SPATA4 has a high expression in testis, especially in testis interstitial, leydig cell, seminiferous tubule and germ cell. Mouse SPATA4 was observed exclusively in adult mouse testis and almost no signal was detected in other tissues. The pI values of the protein are negative, ranging from 9.44 to 10.15. The subcellular location of the protein is usually in the nucleus. And the signal peptide possibilities for SPATA4 are always zero. Using the SNPs data in NCBI, we found 33 SNPs in human SPATA4 gene genomic DNA region, with the distribution of 29 SNPs in the introns. CpG island searching gives the data about CpG island, which shows that the regions of the CpG island have a high similarity with each other, though the length of the CpG island is different from each other.This research is a fundamental work in the fields of the bioinformational analysis, and also put forward a new way for the bioinformatic analysis of other genes.

Image System Using Dual Energy Detector (이중 에너지 검출기를 이용한 영상 시스템)

  • Yeo, Hwa-Yeon
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.11 no.9
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    • pp.3517-3523
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    • 2010
  • Single exposure dual X-ray imaging can be used to separate soft and dense-material images for medical and industrial applications. This study keep focusing baggage inspection system(BIS) specifically. New detector modules for single exposure dual X-ray imaging are consisted of low energy detector (LED) and high energy detector (HED). First, the optimized thickness of copper filter coupled HED to separate low energy and high energy was simulated by the given X-ray energy (140 kVp, 1 mA) using Monte Carlo simulation codes, MCNPX. So as a result of simulation, the copper filter thickness is 0.7 mm. For the design of PIN photodiode, ATLAS device simulation tool was used. 16 channels PIN photodiode of 1.5 mm ${\times}$ 3.2 mm for Dual X-ray imaging detector was fabricated in the process of ETRI. And its dark current and quantum efficiency, terminal capacitance were measured. It was proven that the Lanex Fast B coupled HED were a sufficient candidate to replace the CsI(Tl) commerced in dual X-ray system, since these give a strong signal, overcoming system noise. Finally dual X-ray image was acquired through correction of the LED X-ray Image and the HED X-ray Image.

Evaluation of Therapeutic Efficacy using [18F]FP-CIT in 6-OHDA-induced Parkinson's Animal Model

  • Jang Woo Park;Yi Seul Choi;Dong Hyun Kim;Eun Sang Lee;Chan Woo Park;Hye Kyung Chung;Ran Ji Yoo
    • Journal of Radiopharmaceuticals and Molecular Probes
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    • v.9 no.1
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    • pp.3-8
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    • 2023
  • Parkinson's disease is a neurodegenerative disease caused by damage to brain neurons related to dopamine. Non-clinical animal models mainly used in Parkinson's disease research include drug-induced models of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine and 6-hydroxydopamine, and genetically modified transgenic animal models. Parkinson's diagnosis can be made using brain imaging of the substantia nigra-striatal dopamine system and using a radiotracer that specifically binds to the dopamine transporter. In this study, 18F-N-(3-fluoropropyl)-2β-carboxymethoxy-3β-(4-iodophenyl) nortropane was used to confirm the image evaluation cutoff between normal and parkinson's disease models, and to confirm model persistence over time. In addition, the efficacy of single or combined administration of clinically used therapeutic drugs in parkinson's animal models was evaluated. Image analysis was performed using the PMOD software. Converted to standardized uptake value, and analyzed by standardized uptake value ratio by dividing the average value of left striatum by the average value of right striatum obtained by applying positron emission tomography images to the atlas magnetic resonance template. The image cutoff of the normal and the parkinson's disease model was calculated as SUVR=0.829, and it was confirmed that it was maintained during the test period. In the three-drug combination administration group, the right and left striatum showed a high symmetry of more than 0.942 on average and recovered significantly. Images using 18F-N-(3-fluoropropyl)-2β-carboxymethoxy-3β-(4-iodophenyl) nortropane are thought to be able to diagnose and evaluate treatment efficacy of non-clinical Parkinson's disease.

Quality Characteristics and Variation of Wheat Breeding Lines (소맥육성계통의 품질특성과 변이에 관하여)

  • Chang, H.G.;Ryu, I.S.;Cho, C.H.;Bae, S.H.
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.24 no.1
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    • pp.37-45
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    • 1979
  • Experiments were conducted to determine the physicochemical properties for 1.382 tested wheat harvested in 1977. All the tested wheats had a milling yield rate of 49 to 71.5 percent. The cross combination involving S.son, Caprock and CI 12703 was generally the higher in flour yield-Flour protein content ranged from about 7 percent up to about 17 percent and sedimentation values ranged from below 20 cc to 70 cc. The cross combinations involving Bb #1 gave higher protein content and higher sedimentation values than the other combinations. The distribution of the Pelshenke value was from less 20 min. to more than 180 min. Specific sedimentation values of the 329 tested wheats showed 8.1 percent to be hard quality, while 54.4 percent were of soft quality. Intermediate wheats accounted for 37.5 percent. The lines having high milling yield rate, protein content and sedimentation value from the 329 tested wheats were Strampelli \times 69D-3607/Jogwang. S.son \times Caprock. Suweon #185 \times Toropi and Suweon #185 \times Ciano. The varieties or lines including Pribog, CI 14496 and Sturdy \times Scout/ Strampelli \times Bb-Cno showed high milling yield but low protein content and low sedimentation values. being under 9 percent and 30 cc respectively.

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Hippocampal Sparing Whole Brain Radiotherapy and Integrated Simultaneous Boost vs Stereotactic Radiosurgery Boost: A Comparative Dosimetric Planning Study

  • Cheah, Soon Keat;Matthews, Thomas;Teh, Bin Sing
    • Asian Pacific Journal of Cancer Prevention
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    • v.17 no.9
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    • pp.4233-4235
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    • 2016
  • Background: Whole brain radiotherapy (WBRT) and stereotactic radiosurgery were frequently used to palliate patients with brain metastases. It remains controversial which modality or combination of therapy is superior especially in the setting of limited number of brain metastases. The availability of newer medical therapy that improves survival highlighted the importance of reducing long term radiation toxicity associated with WBRT. In this study, we aim to demonstrate the hippocampal sparing technique with whole brain and integrated simultaneous boost Materials and Methods: Planning data from 10 patients with 1-5 brain metastases treated with SRS were identified. Based on the contouring guideline from RTOG atlas, we identified and contoured the hippocampus with 5mm isocentric expansion to form the hippocampal avoidance structure. The plan was to deliver hippocampal sparing whole brain radiotherapy (HSWBRT) of 30 Gy in 10 fractions and simultaneous boost to metastatic lesions of 30 Gy in 10 fractions each. Results: The PTV, hippocampus and hippocampal avoidance volumes ranges between 1.00 - 39.00 cc., 2.50 - 5.30 cc and 26.47 - 36.30 cc respectively. The mean hippocampus dose for the HSWBRT and HSWBRT and SIB plans was 8.06 Gy and 12.47 respectively. The max dose of optic nerve, optic chiasm and brainstem were kept below acceptable range of 37.5 Gy. Conclusions: The findings from this dosimetric study demonstrated the feasibility and safety of treating limited brain metastases with HSWBRT and SIB. It is possible to achieve the best of both worlds by combining HSWBRT and SIB to achieve maximal local intracranial control while maintaining as low a dose as possible to the hippocampus thereby preserving memory and quality of life.

Simulation of Threshold Voltages for Charge Trap Type SONOS Memory Devices as a Function of the Memory States (기억상태에 따른 전하트랩형 SONOS 메모리 소자의 문턱전압 시뮬레이션)

  • Kim, Byung-Cheul;Kim, Hyun-Duk;Kim, Joo-Yeon
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • v.9 no.1
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    • pp.981-984
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    • 2005
  • This study is to realize its threshold voltage shift after programming operation in charge trap type SONOS memory by simulation. SONOS devices are charge trap type nonvolatile memory devices in which charge storage takes place in traps in the nitride-blocking oxide interface and the nitride layer. For simulation of their threshold voltage as a function of the memory states, traps in the nitride layer have to be defined. However, trap models in the nitride layer are not developed in commercial simulator. So, we propose a new method that can simulate their threshold voltage shift by an amount of charges induced to the electrodes as a function of a programming voltages and times as define two electrodes in the tunnel oxide-nitride interface and the nitride-blocking oxide interface of SONOS structures.

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Influences of Environmental Factors on Wheat Quality II. Effects of Regional Climatic Factors on Protein Content and Sedimentation Value of Wheat Flour (재배 환경조건이 소맥품질에 미치는 영향 II. 지역별 기상조건이 소맥분 단백질함량 및 침전가에 미치는 영향)

  • Ryu, I.S.;Shin, H.K.;Cho, C.H.;Bae, S.H.
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.22 no.2
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    • pp.65-70
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    • 1977
  • The effects of regional climatic factors on wheat quality were discussed. The most important climatic factor on wheat quality during the ripening period of wheat was air temperature during the ripening period of wheat. The protein content and sedimentation value were higher in northern parts of Korea compared to southern parts in Korea. The varietal effects of ripening temperature on protein content and sedimentation value of wheat were varied in nine tested varieties.

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Properties of Galaxies in Cosmic Filaments around the Virgo Cluster

  • Lee, Youngdae;Kim, Suk;Rey, Soo-Chang;Chung, Jiwon
    • The Bulletin of The Korean Astronomical Society
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    • v.45 no.1
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    • pp.64.2-64.2
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    • 2020
  • We present the properties of galaxies in filaments around the Virgo cluster with respect to their vertical distance from the filament spine. Using the NASA-Sloan Atlas and group catalogs, we select galaxies that do not belong to groups in filaments. The filament member galaxies are then defined as those located within 3.5 scale length from the filament spine. The filaments are mainly (~86%) composed of low-mass dwarf galaxies of logh2M∗/M⊙ < 9 dominantly located on the blue cloud in color-magnitude diagrams. We observe that the g - r color and stellar mass of galaxies correlate with their vertical distance from the filament spine in which the color becomes red and stellar mass decreases with increasing vertical filament distance. The galaxies were divided into two subsamples in different stellar mass ranges, with lower-mass (logh2M∗/M⊙ ≤ 8) galaxies showing a clear negative g-r color gradient, whereas higher-mass (logh2M∗/M⊙ > 8) galaxies have a flat distribution against the vertical filament distance. We observe a negative EW(Hα) gradient for higher-mass galaxies, whereas lower-mass galaxies show no distinct variation in EW(Hα) against the vertical filament distance. In contrast, the NUV - r color distribution of higher-mass galaxies shows no strong dependence on the vertical filament distance, whereas the lower-mass galaxies show a distinct negative NUV - r color gradient. We do not witness clear gradients of HI fraction in either the higher- or lower-mass subsamples. We propose that the negative color and stellar mass gradients of galaxies can be explained by mass assembly from past galaxy mergers at different vertical filament distances. In addition, galaxy interactions might be responsible for the contrasting features of EW(Hα) and NUV - r color distributions between the higher- and lower-mass subsamples. The HI fraction distributions of the two subsamples suggest that ram-pressure stripping and gas accretion could be ignorable processes in the Virgo filaments.

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