• Title/Summary/Keyword: space formation

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Recent Star Formation History of M31 and M33

  • Kang, Yongbeom;Bianchi, Luciana;Rey, Soo-Chang
    • The Bulletin of The Korean Astronomical Society
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    • v.38 no.2
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    • pp.45.2-45.2
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    • 2013
  • We studied recent evolution of M31 and M33 with star-forming regions and hot massive stars. We use GALEX far-UV and near-UV imaging to detect the star-forming regions and trace the recent star formation across the entire disk of galaxies. The GALEX imaging, combining deep sensitivity and entire coverage of these galaxies, provides a complete picture of the recent star formation in M31 and M33, and its variation with environment throughout these galaxies. We also show results from recent extensive surveys in M31 and M33 with Hubble Space Telescope multi-wavelength data including UV filters, which imaged several regions at a linear resolution of less than half a pc in these galaxies. Both datasets allow us to study the hierarchical structure of star formation: the youngest stellar groups are the most compact, and are often arranged withing broader, sparser structures. The derived recent star-formation rates are rather similar for the two galaxies, when scaled for the respective areas.

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Modification of a cosmological hydrodynamic code for more realistic baryonic physics

  • Chun, Kyungwon;Shin, Jihye;Kim, Sungsoo S.
    • The Bulletin of The Korean Astronomical Society
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    • v.39 no.2
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    • pp.45.1-45.1
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    • 2014
  • structure of matters of Lambda cold dark matter (CDM) cosmology on detailed numerical simulations. To accomplish our research goal, we have added the following baryonic physics on the existing cosmological hydrodynamic code, Gadget-2: 1) radiative heating and cooling, 2) reionization of the Universe and UV shielding, 3) star formation, 4) energy and metallicity feedback by supernova. In addition, we included cluster formation to distinguish clustered star formation inside the very high density gas clumps from the field star formation. Our simulations cover a cubic box of a side length 4Mpc/h with 130 million particles. The mass of each particles is $3.4{\times}104Msun$, thus the GCs can be resolved with more than hundreds particles. We discuss various properties of the GCs such as mass function, specific frequency, baryon-to-dark matter ratio, metallicity, spatial distribution, and orbit eccentricity distribution as functions of redshift. We also discuss how the formation and evolution of the GCs are affected by UV shielding.

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A Study on Building Envelope and Formation of Flexible Boundary - Focused on Contemporary Architecture of Toyo Ito and SANAA - (외피 구조를 통한 경계의 유연성 형성에 관한 연구 - 토요 이토와 SANAA의 현대 건축을 중심으로 -)

  • Choe, San-Ki
    • Korean Institute of Interior Design Journal
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    • v.19 no.2
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    • pp.81-89
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    • 2010
  • The problem of defining the relationship between interior space and exterior envelope of a building has long been a challenging task in the field of architecture throughout its history. This research chronologically reviews some of the important turning points in various schools of thoughts concerning construction of exterior envelope, with focus on how they influenced and altered the formation of our interior environment. This research also stipulates on how technological advance in the late 20th century laid grounds for a new type of interior-exterior relations in architecture through creation of flexible and ambiguous boundary conditions. The focus of this qualitative research will be on contemporary works of Japanese architects Toyo Ito, SANAA, and related group of architects who address the issues of transparency, flexible interior layout, buffer zones, structural facade, and neutralized (homogeneous) space that produces spatial quality of non-linear, non-hierarchical, and de-materialized space as a direct alternative to modern principles of space making.

Star Formation Histories of the Globular Clusters with Multiple Stellar Populations

  • Joo, Seok-Joo;Lee, Young-Wook;Yoon, Suk-Jin;Han, Sang-Il
    • Bulletin of the Korean Space Science Society
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    • 2009.10a
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    • pp.29.3-29.3
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    • 2009
  • Recent observations for the Galactic globular clusters (GCs) have shown that a number of GCs have characteristic features of multiple stellar populations, such as multiple main-sequences (MSs), splits in sub-giant branch (SGB), bimodal and/or extended horizontal branches (HBs). Based on the population synthesis models, we investigate star formation histories of the GCs with multiple populations, $\omega$ Cen, M54, NGC 1851, NGC 6388, NGC 6441, and NGC 2808, by comparing synthetic model color-magnitude diagrams (CMDs) with observations. We adopt most up-to-date Yonsei-Yale (Y2) stellar evolutionary tracks and isochrones from MS to post-HB, as well as improved color-temperature transformations from the recent stellar atmosphere libraries. Our models show that the observed features can be naturally explained by assuming the presence of helium-enhanced subpopulations.

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TRAO-TIMES: Investigating Turbulence and Chemistry in Two Star-forming Molecular clouds

  • Yun, Hyeong-Sik;Lee, Jeong-Eun;Choi, Yunhee;Evans, Neal J. II;Offner, Stella S.R.;Baek, Giseon;Lee, Yong-Hee;Choi, Minho;Kang, Hyunwoo;Cho, Jungyeon;Lee, Seokho;Tatematsu, Ken'ichi;Heyer, Mark H.;Gaches, Brandt A.L.;Yang, Yao-Lun
    • The Bulletin of The Korean Astronomical Society
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    • v.46 no.2
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    • pp.37.2-37.2
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    • 2021
  • Turbulence produces the density and velocity fluctuations in molecular clouds, and dense regions within the density fluctuation are the birthplace of stars. Also, turbulence can produce non-thermal pressure against gravity. Thus, turbulence plays a crucial roles in controlling star formation. However, despite many years of study, the detailed relation between turbulence and star formation remain poorly understood. As part of the Taeduk Radio Astronomy Observatory (TRAO) Key Science Program (KSP), "mapping Turbulent properties In star-forming MolEcular clouds down to the Sonic scale (TIMES; PI: Jeong-Eun Lee)", we mapped two star-forming molecular clouds, the Orion A and the ρ Ophiuchus molecular clouds, in six molecular lines (13CO 1-0/C18O 1-0, HCN 1-0/HCO+ 1-0, and CS 2-1/N2H+ 1-0) using the TRAO 14-m telescope. We applied the Principal Component Analysis (PCA) to the observed data in two different ways. The first method is analyzing the variation of line intensities in velocity space to evaluate the velocity power spectrum of underlying turbulence. We investigated the relation between the star formation activities and properties of turbulence. The other method is analyzing the variation of the integrated intensities between the molecular lines to find the characteristic correlation between them. We found that the HCN, HCO+, and CS lines well correlate with each other in the integral shaped filament in the Orion A cloud, while the HCO+ line is anti-correlate with the HCN and CS lines in L1688 of the Ophiuchus cloud.

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Urban Regeneration of Old Town in the Rural City by the Recovery of Publicness - Focused on the Example of the History, Culture, Eco City, Gosan, Wanjoo - (공공성 회복을 통한 지방 소도시 구도심재생 연구 - 역사, 문화, 생태 도시 완주군 고산을 사례로 -)

  • Yoon, Sung-Hoon;Yun, Hee-Jin
    • KIEAE Journal
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    • v.15 no.3
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    • pp.83-92
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    • 2015
  • Purpose: The purpose of this study is to propose a methodology for the urban regeneration by constructing contemporary publicness. Beginning with researching on the theoretical fundamentals about publicness and urban regeneration, it introduces the examples to analyze the spatial characteristics of publicness in the contemporary urban architecture, and finally simulates a model for the formation of space through a real work. Method: The study is partially based on the Executive Urban Project, 'Masterplan to make New Taekrigi : Gosan', which was planned in 2013 to suggest a strategic settlement layout for urban regeneration. Making architectural ideas permeated into the model of urban planing, throughout the design process of initially pursued concepts to the design development stage, we could encounter a new type of formation of urban space, coinciding with the historical, cultural ecological contexts. Result: The expected result of the study intends to enhance the relationship between the formation of public space and urban structure, also ultimately to produce a urban system as 'space generator' to fulfill the social needs and its requirements.

Magnetic Field Structure and Formation Scenario of the N159/N160 Star-Forming Complex in the Large Magellanic Cloud

  • Kim, Jaeyeong;Jeong, Woong-Seob;Pyo, Jeonghyun;Pak, Soojong;Park, Won-Kee;Kwon, Jungmi;Tamura, Motohide
    • The Bulletin of The Korean Astronomical Society
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    • v.42 no.1
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    • pp.38.3-39
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    • 2017
  • The N159 and N160 ionized regions in the Large Magellanic Cloud are an important extragalactic star-forming complex. The physical environments and the star formation stages are different in N159 and N160. We performed near-infrared polarimetry to those star forming regions with IRSF/SIRPOL 1.4-m telescope. Near-infrared polarization enabled us to trace the detailed structure of magnetic fields in star-forming regions. Through the polarimetric data of J, H, and Ks bands, we examined the magnetic field structures in the N159/N160 complex. In this presentation, we show complex distribution of the magnetic fields associated with dust and gas structures. We verify the local magnetic fields in each star-forming region, which appear to be related with local environments, such as interior and boundary of shell structure, star-forming HII regions, and boundaries between HII regions and dense dark clouds. We discuss the formation scenario of the N159/N160 complex suggested from the magnetic field structure.

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Multiple Molecular Line Analysis in the Planck Cold Clumps with KVN Follow-up Observations.

  • Kang, Sung-ju;Liu, Tie;Kim, Kee-Tae;Choi, Minho;Kang, Miju;Lee, Jeong-Eun;Evans, Neal J.
    • The Bulletin of The Korean Astronomical Society
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    • v.42 no.1
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    • pp.32.2-32.2
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    • 2017
  • Stars form in dense core within the molecular clouds. The prestellar cores provide information of the physical characteristics at the very early stages of star formation. The low dust temperature (<14K) of Planck cold clumps/cores (PGCCs) make them likely to be prestellar objects or at the very initial stage of protostellar collapse. We have been conducting the legacy surveys of Planck cold clumps with the JCMT, the TRAO 14-m and many other telescopes. We aim to study of the initial conditions of star formation and chemical evolutions of the cores in the different environments. From JCMT SCUBA-2 $850{\mu}m$ survey (SCOPE), we have already identified hundreds of dense cores, which may be at the earliest phase of star formation. Therefore in order to explore the chemical evolution of these dense cores, we used KVN telescopes in order to observe 75 well selected SCUBA-2 cores in many molecules as the follow-up project of KVN Pilot Observation of SCUBA-2. These observations will help advance our understanding of the propoerties of these SCUBA-2 cores in PGCCs.

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A Study on the Expression Tendency in Contemporary Interior Architecture based on the Concept of the Placeness (장소성 개념이 적용된 실내건축의 표현 양상에 관한 연구)

  • Lee, Yu-Hwa;Kim, Jong-Jin
    • Proceedings of the Korean Institute of Interior Design Conference
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    • 2008.05a
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    • pp.134-138
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    • 2008
  • In modern society, the place we live and reside decides quality of our lives and pattern of behaviors, and it appears with indeterminative and circulating forms. The place provides different experiences and restrictions to us as intentions of human being and order of nature merges into each other. Formation of such place decides the character depending on its relationship of orders. There would be various methods to prescribe for the ability, that is, characteristics, of space. It is the purpose of this research to classify different components defining the character of the space based on a general notion of place and to find out how it is reflected in the space itself. It is to analyze difference case studies by finding out the relationship between the factors affecting the formation of places and aspects of different expressions within the space. The research would assist in forming different harmonious places reflecting the phases of this modern time as designing interior spaces, and it is also to provide footstone for the formation of space which is not only growing but also future oriented.

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An Analysis of Multi-View Fashion Design Reflected in the Perception of Time and Space (연속적 시·공간관이 반영된 다(多)시점 패션디자인 분석)

  • Kim, Minji;Kan, Hosup
    • Journal of Fashion Business
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    • v.19 no.2
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    • pp.136-148
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    • 2015
  • The purpose of this thesis is to study multi-view fashion design with an analysis of multi-view art's formation and philosophical perspective. The production of unique artwork is dependent on how we see, think and represent what is around us. Multi-view art has great potential as a concept related to the continuity of time and space, it is not limited to space and time but it extends to infinitely, according to the artist's will and imagination. The study of time and space has been used as principles for deriving the formative of multi-view art, and the principles applied for analyzing multi-view fashion design. And the formation of multi-view art is reflected in fashion design. Simultaneity, deconstructivity, continuity and virtuality in terms of multi-view art are support the formation of multi-view fashion design, such as fabrication, expandability, concealment and transparency. As such, it is important to study multi-view fashion design as a creative design method with immense potential for further development.