• 제목/요약/키워드: catalogues

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Cosmological constraints using BAO - From spectroscopic to photometric catalogues

  • Sridhar, Srivatsan
    • 천문학회보
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    • 제44권1호
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    • pp.56.2-56.2
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    • 2019
  • Measurement of the location of the baryon acoustic oscillation (BAO) feature in the clustering of galaxies has proven to be a robust and precise method to measure the expansion of the Universe. The best constraints so far have been provided from spectroscopic surveys because the errors on the redshift obtained from spectroscopy are minimal. This in turn means that the errors along the line-of-sight are reduced and so one can expect constraints on both angular diameter distance $D_A$ and expansion rate $H^{-1}$. But, future surveys will probe a larger part of the sky and go to deeper redshifts, which correspond to more number of galaxies. Analysing each galaxy using spectroscopy, which is a time consuming task, will not be practically possible. So, photometry will be the most convenient way to measure redshifts for future surveys such as LSST, Euclid, etc. The advantage of photometry is measuring the redshift of vast number of galaxies in a single exposure, but the disadvantage are the errors associated with the measured redshifts. Using a wedge approach, wherein the clustering is split into different wedges along the line-of-sight ${\pi}$ and across the line-of-sight ${\sigma}$, we show that the BAO information can be recovered even for photometric catalogues with errors along the line-of-sight. This means that we can get cosmological distance constraints even if we don't have spectroscopic information.

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Detecting the Baryon Acoustic Oscillations in the N-point Spatial Statistics of SDSS Galaxies

  • Hwang, Se Yeon;Kim, Sumi;Sabiu, Cristiano G.;Park, In Kyu
    • 천문학회보
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    • 제46권2호
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    • pp.72.3-73
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    • 2021
  • Baryon Acoustic Oscillations (BAO) are caused by acoustic density waves in the early universe and act as a standard ruler in the clustering pattern of galaxies in the late Universe. Measuring the BAO feature in the 2-point correlation function of a sample of galaxies allows us to estimate cosmological distances to the galaxies mean redshift, , which is important for testing and constraining the cosmology model. The BAO feature is also expected to appear in the higher order statistics. In this work we measure the generalized spatial N-point point correlation functions up to 4th order. We made measurements of the 2, 3, and 4-point correlation functions in the SDSS-III DR12 CMASS data, comprising of 777,202 galaxies. The errors and covariances matrices were estimated from 500 mock catalogues. We created a theoretical model for these statistics by measuring the N-point functions in halo catalogues produced by the approximate Lagrangian perturbation theory based simulation code, PINOCCHIO. We created simulations using initial conditions with and without the BAO feature. We find that the BAO is detected to high significance up to the 4-point correlation function.

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선진 유통업체 전자 카탈로그 활용 사례 (Use of Electronic Catalog in Retail Industry)

  • 최문실
    • 한국전자거래학회:학술대회논문집
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    • 한국전자거래학회 2001년도 International Conference CALS/EC KOREA
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    • pp.439-448
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    • 2001
  • Data Alignment is achieved when all trading partners information systems are maintained automatically synchronising with the suppliers information systems on a continuing basis. Electronic catalogues facilitate the ongoing synchronisation of data between trading partners and large retailers in United States and Canada use electronic catalog in order to get rid of non-value added paperwork and manual reconciliation. Data Alignment will dramatically improve the effectiveness of E-Commerce and Supply Chain initiatives including electronic Marketplaces, Collaborative Planning and Forecasting and continuous replenishment processes.

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Electronic Catalogues the Foundation for Electronic Commerce

  • Spinks, Colin
    • 한국전자거래학회:학술대회논문집
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    • 한국전자거래학회 2001년도 e-Biz World Conference
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    • pp.457-476
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    • 2001
  • ● Provide a central point for all Supply Chain Product Information for all industries. ● Create total Data alignment between ALL members of a Logical Trading Community. The management of content is a key element in the implementation of an e-procurement solution As a buyer are you able to maintain your own catalogue? As a supplier are you able to maintain a catalogue that can be accessed by buyers? A Managed Catalogue is an option that should be considered(omitted)

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국내 4년제 대학의 MIS학과 교과과정의 운영실태에 관한 연구 (A Study on the MIS Curriculum in Domestic Four-year Universities)

  • 김영문
    • Asia pacific journal of information systems
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    • 제4권1호
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    • pp.47-73
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    • 1994
  • This paper investigated the MIS curriculum of fifteen four-year universities in South Korea. The data for analyses was collected from the university catalogues, questionnaire, and telephone interviews. Based on the data collected, this paper reported the current status of domestic MIS departments and analyzd the curriculum using the conceptual framework. The research results were discussed in terms of three issues : (1) the operations of MIS curriculum, (2) the sequences of selected MIS courses, (3) the course titles. This papers finally discussed the limitations of the current study and the future research directions.

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VLBI MEASUREMENT OF WEAK SOURCES WITH IMPROVED SENSITIVITY

  • SHU, FENGCHUN;JIANG, WU
    • 천문학논총
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    • 제30권2호
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    • pp.651-653
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    • 2015
  • Compared with traditional analog system, the Chinese VLBI Data Acquisition System (CDAS) is a digital one with better bandpass and wider bandwidth which allow weaker sources to be detected and measured by VLBI techniques. After optimizing and verifying the performance of CDAS in wide bandwidth observing mode, we performed an experiment by observing 85 weak sources along the ecliptic with Chinese VLBI stations located at Shanghai, Kunming and Urumqi. The capability of CDAS has been demonstrated for the detection of weak sources with improved sensitivity.

조선시대 여성 폐면용 쓰개의 특징 - 박물관 유물을 중심으로 - (The Characteristic of Women's Veils in Chosun Dynasty Period - Focusing on the Museum Collection -)

  • 류보영;임상임
    • 한국의류학회지
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    • 제26권10호
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    • pp.1424-1435
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    • 2002
  • This study is about women's veils from Chosen period housed in various museums and see how they reflect the escalating inequality between the two sexes based on Confucianism and its social ramifications including the strict rules that kept women from freely communicating or staying in same quarters with men from tender age. I first visited various museums to see what kind of veils they had in their collections and then looked at reproductions, museum catalogues, and other studies to get a better understanding of the designs, colors, and fabrics of the veils in each collection and came to following conclusions:. 1. I looked at 26 veils of 7 different sues both in person and in museum catalogues, and they included a Neouls,3 Myunsas, l2Jahngots,4 Chuneuis,1 Sahkgat 3Junmos, and 1 Garima. Various documents attest to the existence of one more style of veil,1. e. skirt-shaped veil, but there was no specimen of the type. 2. Museums had various types of veils for women, but most of them dated from late Chosun period. 3. Female veils in Chosun period had dearly-defined characteristics depending on their wearers. Each type had its own fabric color, and form, so one could tell the status of the wearer just by looking at it 4. The veils that I found at museums around the country had following characteristics: . Neoul was worn by high-class women and it covered up the face better than other types of veils. Myunsa was also caned Myunsapo, and it featured brilliant gold foils to mark the salted status of the wearer. Jahngot was originally a robe for both sexes but it turned into a type of veil for low-class females in late am period and there were more Jangots in museum collections than my other type of veils. Chuneui has various styles and it has a cotton lining so low-class women wore it to both cover the face and to stay worn Sahkgat was worn by low-class women for its convenience. Junmo was elaborately decorated and showy, and it was worn by courtesans. Garima was worn by courtesans or professional women in medicine, and unlike other type of veils, it showed the face of the wearer.

산개성단 M50 영역의 변광성 (VARIABLE STARS IN THE REGION OF AN OPEN CLUSTER M50)

  • 전영범
    • 천문학논총
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    • 제23권2호
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    • pp.17-23
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    • 2008
  • From the short-period variability survey (SPVS), we obtained time-series BV CCD images in the region of an open cluster M50 (NGC 2323) for 10 nights from 2008 February 9 to 27. The observation was performed using a small refracting telescope (${\phi}$=155mm, f=1050mm) in Bohyunsan Optical Astronomy Observatory (BOAO). M50 is included in the observing field of ASAS (The All Sky Automated Survey). In the region of M50, we found 8 new variable stars including two ${\delta}$ Scuti stars with short-periods and very small amplitudes. There are known nine variable stars by the catalogues of ASAS and GCVS in the region. We confirmed the variability of the known variable stars for six and non-variability for three.

디지털 라이브러리 모형에 관한 연구 (A Study on Modeling of Digital Libraries)

  • 이창열
    • 한국문헌정보학회지
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    • 제32권4호
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    • pp.117-140
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    • 1998
  • 전통적 도서관은 인터넷 기술의 발달로 인하여 새로운 형태의 디지털 라이브러리로 변모하고 있다. 책은 디지털 파일로, 목록은 메타데이타로, 이용자는 네트워크가 접속되는 전세계 이용자로, 자료는 무한정 복사할 수 있는 형태로 바뀌고 있다. 국가 정보 하부구조를 위한 디지털 라이브러리 구축은 미래 정보화 사회에 매우 중요한 것으로 본 논문에서는 기존의 디지털 라이브러리 기술에 대한 분석을 통하여 앞으로 추진할 디지털 라이브러리의 모습을 모델링한다.

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