• Title/Summary/Keyword: small universe

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The Horizon Run 5 Cosmological Hydrodynamical Simulation: Probing Galaxy Formation from Kilo- to Giga-parsec Scales

  • Lee, Jaehyun;Shin, Jihey;Snaith, Owain N.;Kim, Yonghwi;Few, C. Gareth;Devriendt, Julien;Dubois, Yohan;Cox, Leah M.;Hong, Sungwook E.;Kwon, Oh-Kyoung;Park, Chan;Pichon, Christophe;Kim, Juhan;Gibson, Brad K.;Park, Changbom
    • The Bulletin of The Korean Astronomical Society
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    • v.45 no.1
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    • pp.38.2-38.2
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    • 2020
  • Horizon Run 5 (HR5) is a cosmological hydrodynamical simulation which captures the properties of the Universe on a Gpc scale while achieving a resolution of 1 kpc. This enormous dynamic range allows us to simultaneously capture the physics of the cosmic web on very large scales and account for the formation and evolution of dwarf galaxies on much smaller scales. Inside the simulation box. we zoom-in on a high-resolution cuboid region with a volume of 1049 × 114 × 114 Mpc3. The subgrid physics chosen to model galaxy formation includes radiative heating/cooling, reionization, star formation, supernova feedback, chemical evolution tracking the enrichment of oxygen and iron, the growth of supermassive black holes and feedback from active galactic nuclei (AGN) in the form of a dual jet-heating mode. For this simulation we implemented a hybrid MPI-OpenMP version of the RAMSES code, specifically targeted for modern many-core many thread parallel architectures. For the post-processing, we extended the Friends-of-Friend (FoF) algorithm and developed a new galaxy finder to analyse the large outputs of HR5. The simulation successfully reproduces many observations, such as the cosmic star formation history, connectivity of galaxy distribution and stellar mass functions. The simulation also indicates that hydrodynamical effects on small scales impact galaxy clustering up to very large scales near and beyond the baryonic acoustic oscillation (BAO) scale. Hence, caution should be taken when using that scale as a cosmic standard ruler: one needs to carefully understand the corresponding biases. The simulation is expected to be an invaluable asset for the interpretation of upcoming deep surveys of the Universe.

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A Study on the Space Composition of Renaissance Monastery Certosa - Based on the Cell Space in Certosa di Pavia (르네상스 수도원 체르토사의 공간 구성에 관한 연구 - 체르토사 디 파비아의 셀 공간을 중심으로 -)

  • Lim, Jong-Yup
    • Korean Institute of Interior Design Journal
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    • no.34
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    • pp.106-113
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    • 2002
  • Certosa, a representative Monastic Architecture of Renaissance era, has been well preserved. And it has worked as a symbol of the space form & style revealed by monad, sell, arcade and court, which are characteristic of a monastery. A court is divided into large court and small one, and it connects each units and each sells through the annex with clarifying each space identities. And arcade and pillar is not only to derive a unitary space from entire space, but also to try openness and extension applying a different height in spite of physical closure of style. Especially planned by monad and cell, the routine space of monks, a structure of rational space is a yardstick of moderation and frugality, showing affluent space which occupy essential areas without extra space. And the space appears self-sufficiency, honest poverty, and affluence with order and eternity based on elementary principles of the Cartusio order in composition and plan of the space. Keeping strong linking with entire sells in the monastery, Each sell symbolizes entire sells, and the inverse is the same. And it is the universe advocating eternity and it is also a small city which provides the monks with accurate modules and scales in the very recluse space.

Kyung Hee University Automatic Observing Software for 10 cm Telescope (KAOS10)

  • Kim, Changgon;Han, Jimin;Ji, Tae-Geun;Lee, Hye-In;Pak, Soojong;Im, Myungshim
    • The Bulletin of The Korean Astronomical Society
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    • v.44 no.1
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    • pp.72.3-72.3
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    • 2019
  • The observation of transient objects such as supernovae or variable stars requires a survey of the wide sky and quickly extracting the results. In accordance with this purpose, we have been developing an automatic observing software, KAOS (Kyung Hee University Automatic Observing Software) as a series. KAOS30 was the first series of KAOS and it was applied to the 30-inch platform at the McDonald Observatory in the United States of America. KAOS76 controls the 76-cm telescope at Kyung Hee Astronomical Observatory. In this poster, we introduce KAOS10 for controlling a portable telescope with a small aperture size attaching a guiding camera as QHY-5L II. Kyung Hee University auto-guiding package which includes the auto-guiding function for small aperture size telescope was also developed. Additionally, the Telescope Control Package(TCP) can communicate with the main server to do astrometry for pointing and identifying targets efficiently. KAOS10 has a universal interface that will be useful for the research of both amateurs and professionals.

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All-In-One Observing Software for Small Telescope

  • Han, Jimin;Pak, Soojong;Ji, Tae-Geun;Lee, Hye-In;Byeon, Seoyeon;Ahn, Hojae;Im, Myungshin
    • The Bulletin of The Korean Astronomical Society
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    • v.43 no.2
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    • pp.57.2-57.2
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    • 2018
  • In astronomical observation, sequential device control and real-time data processing are important to maximize observing efficiency. We have developed series of automatic observing software (KAOS, KHU Automatic Observing Software), e.g. KAOS30 for the 30 inch telescope in the McDonald Observatory and KAOS76 for the 76 cm telescope in the KHAO. The series consist of four packages: the DAP (Data Acquisition Package) for CCD Camera control, the TCP (Telescope Control Package) for telescope control, the AFP (Auto Focus Package) for focusing, and the SMP (Script Mode Package) for automation of sequences. In this poster, we introduce KAOS10 which is being developed for controlling a small telescope such as aperture size of 10 cm. The hardware components are the QHY8pro CCD, the QHY5-II CMOS, the iOptron CEM 25 mount, and the Stellarvue SV102ED telescope. The devices are controlled on ASCOM Platform. In addition to the previous packages (DAP, SMP, TCP), KAOS10 has QLP (Quick Look Package) and astrometry function in the TCP. QHY8pro CCD has RGB Bayer matrix and the QLP transforms RGB images into BVR images in real-time. The TCP includes astrometry function which adjusts the telescope position by comparing the image with a star catalog. In the future, We expect KAOS10 be used on the research of transient objects such as a variable star.

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Near-Infrared Imaging Spectroscopic Survey in Space

  • Jeong, Woong-Seob;Park, Sung-Joon;Moon, Bongkon;Lee, Dae-Hee;Park, Won-Kee;Lee, Duk-Hang;Ko, Kyeongyeon;Pyo, Jeonghyun;Kim, Il-Joong;Park, Youngsik;Nam, Ukwon;Kim, Minjin;Ko, Jongwan;Song, Yong-Seon;Im, Myungshin;Lee, Hyung Mok;Lee, Jeong-Eun;Shin, Goo-Hwan;Chae, Jangsoo;Matsumoto, Toshio
    • The Bulletin of The Korean Astronomical Society
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    • v.40 no.1
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    • pp.54.3-54.3
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    • 2015
  • To probe the star formation in local and early Universe, the NISS with a capability of imaging spectroscopy in the near-infrared is being developed by KASI. The main scientific targets are nearby galaxies, galaxy clusters, star-forming regions and low background regions. The off-axis optical design of the NISS with 15cm aperture was optimized to obtain a wide field of view (FoV) of $2deg.{\times}2deg.$ as well as a wide spectral coverage from 0.9 to $3.8{\mu}m$. The opto-mechanical structure was designed to be safe enough to endure in both the launching condition and the space environment. The dewar will operate $1k{\times}1k$ infrared sensor at 80K stage. The NISS will be launched in 2017 and explore the large areal near-infrared sky up to $200deg.^2$ in order to get both spatial and spectral information for astronomical objects. As an extension of the NISS, KASI is planning to participate in a new small space mission together with NASA. The promising candidate, SPHEREx (Spectro-Photometer for the History of the Universe Epoch of Reionization, and Ices Explorer) is an all-sky survey satellite designed to reveal the origin of the Universe and water in the planetary systems and to explore the evolution of galaxies. Though the survey concept is similar to that of the NISS, the SPHEREx will perform the first near-infrared all-sky imaging spectroscopic survey with the wider spectral range from 0.7 to $5{\mu}m$ and the wider FoV of $3.5deg.{\times}7deg.$ Here, we report the current status of the NISS and introduce new mission for the near-infrared imaging spectroscopic survey.

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Perceptual Change of Undergraduate Students Majored in Theology about the Origins of Universe and Life (우주와 생명의 기원에 대한 신학 전공 대학생의 관점 변화)

  • Ahn, Yu-Min;Jung, Jae-Hoon;Choe, Seung-Urn
    • Journal of the Korean earth science society
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    • v.30 no.3
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    • pp.317-329
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    • 2009
  • By comparing the understandings of theology major with science major in a college, this study investigates how theology major students view the origin of universe and life and how they portray the view of sciences. In addition, this study examines how theology majors change their viewpoints through a series of lectures related to understanding of the modem sciences. Twenty six theology majors and nineteen science education majors participated in the survey investigation. For theology majors, questionnaire data revealed that 42% of theology majors support theistic evolution, while 42% responses with young and old Earth creation and none with evolutionism. On the other hand, most respondents in science education major espoused evolutionism and no one with extreme creationism. Most respondents with creationism shared the insights that science is an instrument for describing the creator's work, whereas most with evolutionisms perceived science as a logical and descriptive system of the natural world. After taking science courses, the theology majors' support of an extreme view like young Earth creationism has decreased by 4% (was 23%), while their support of the theistic evolution increased by a small percentage. This result lends support to the idea that science related courses helps theology major undergraduate students to understand the scientific evolutionism based on their theological backgrounds.

HUBBLE SPACE TELESCOPE IMAGING OF GLOBULAR CLUSTERS IN TWO FACE-ON LOW SURFACE BRIGHTNESS GALAXIES UGC 5981 AND UGC 6614

  • Kim, Ji-Hoon
    • Journal of The Korean Astronomical Society
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    • v.44 no.5
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    • pp.151-160
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    • 2011
  • We present a study searching for globular cluster systems (GCSs) of two face-on low surface bright- ness galaxies (LSBGs), UGC 5981 and UGC 6614. Based on HSTWFPC2 images of F555Wand F814W filters, we detect 12 and 18 GC candidates for UGC 5981 and UGC 6614, respectively. Although these two LSBGs have very different bulge properties, they have very similar specific frequencies ($S_N$) of 0.1. However, $S_N$ ~ 0.1 is quite small even for their late morphological types, albeit within errors. This suggests that LSBGs have had star formation histories lacking dominant initial starburst events while accumulating their stellar masses through sporadic star formation activities.

A Study on the Korean Traditional Landscape in the View of the Meaning of Contemporary Landscape (현대 경관 의미에서 조명해 본 한국의 전통경관 -곡과 선을 중심으로-)

  • 최기수
    • Journal of the Korean Institute of Landscape Architecture
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    • v.17 no.2
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    • pp.57-68
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    • 1989
  • This paper is studied on the korean traditional landscape in the view of the meaning of the contemporary landscape. The landscape architecture is expanding in the various research field of landscape. The seven concept of landscape can be divided as a regional concept, a land- form concept, an ecological concept, a land use concept, a heritage concept, a scenery concept, and a park and garden concept. This paper is deal with 985 kyoung(景) in 104 places and 16 Gok(曲) in 16 places as the korean traditional landscape. The object of landscape is generally focus on a reality as well as an unreality. In kyoung and Gok, the landscape is organized as an order of a small universe. The expression of the structure of korean traditional landscape is the fifth dimensional space which is organized by the third dimensional space with a time, an image and a feeling.

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Ultra-Fast Flash Observatory (UFFO) for early photon measurements from Gamma Ray Bursts

  • Park, Il H.
    • The Bulletin of The Korean Astronomical Society
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    • v.37 no.2
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    • pp.66-66
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    • 2012
  • We describe the space project of Ultra-Fast Flash Observatory (UFFO), which will observe early optical photons from gamma-ray bursts (GRBs) with a sub-second optical response, for the first time. The UFFO will probe the early optical rise of GRBs, opening a completely new frontier in GRB and transient studies, using a fast-response rotatable mirror system which redirects opitical path to telescope instead of slewing of telescopes or spacecraft. In our small UFFO-Pathfinder experiment, scheduled to launch aboard the Lomonosov satellite in June 2012, we use a motorized mirror in our Slewing Mirror Telescope instrument to achieve less than one second optical response after X-ray trigger. We describe the science and the mission of the UFFO project, including a serious version called UFFO-100 which will be launched in 2014. With our program of ultra-fast optical response GRB observatories, we aim to gain a deeper understanding of GRB mechanisms, and potentially open up the z>10 universe to study via GRB as point source emission probes.

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Formation of First Astrophysical Objects under the Influence of Large-Scale Density and Velocity Environment

  • Ahn, Kyungjin;Smith, Britton D.
    • The Bulletin of The Korean Astronomical Society
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    • v.44 no.1
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    • pp.55.5-55.5
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    • 2019
  • We present our first attempt at understanding the dual impact of the large-scale density and velocity environment on the formation of very first astrophysical objects in the Universe. Following the recently developed quasi-linear perturbation theory on this effect, we introduce the publicly available initial condition generator of ours, BCCOMICS (Baryon Cold dark matter COsMological Inital Condition generator for Small scales), which provides so far the most self-consistent treatment of this physics beyond the usual linear perturbation theory. From a suite of uniform-grid simulations of N-body+hydro+BCCOMICS, we find that the formation of first astrophysical objects is strongly affected by both the density and velocity environment. Overdensity and streming-velocity (of baryon against cold dark matter) are found to give positive and negative impact on the formation of astrophysical objects, which we quantify in terms of various physical variables.

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