• Title/Summary/Keyword: compact groups

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ALMA/ACA CO (1-0) observations of group galaxies

  • Lee, Bumhyun;Wang, Jing;Chung, Aeree;Ho, Luis C.;Wang, Ran;Shao, Li;Michiyama, Tomonari;Wang, Shun;Peng, Eric W.;Kilborn, Virginia
    • The Bulletin of The Korean Astronomical Society
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    • v.45 no.1
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    • pp.64.1-64.1
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    • 2020
  • Galaxy groups are the place where many galaxies feel the impact of the surroundings (e.g., merging, tidal interaction, ram pressure stripping) before joining bigger structures like (sub)clusters. A significant fraction of galaxies is quenched in the group environment. Such "pre-processing" of galaxies in groups is likely to affect galaxy evolution tremendously. To better understand how environmental processes in galaxy groups affect molecular gas, star formation activity, and galaxy evolution, we carried out CO imaging observations of group galaxies, using the Atacama Compact Array (ALMA/ACA). We selected all the targets that have been detected in the GEMS-HI survey for two groups, making the sample of 40 galaxies (18 galaxies in IC 1459 group and 22 galaxies in NGC 4636 group). Our ALMA/ACA observation is the first CO imaging survey for two groups. In this work, we present CO images of group galaxies, together with their star formation maps and HI images. Our ACA CO data show the asymmetric distribution of molecular gas in some of our samples. We discuss the impact of the group environment on molecular gas and star formation activity.

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HARMONIC HOMOMORPHISMS BETWEEN TWO LIE GROUPS

  • Son, Heui-Sang;Kim, Hyun Woong;Park, Joon-Sik
    • Honam Mathematical Journal
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    • v.38 no.1
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    • pp.1-8
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    • 2016
  • In this paper, we get a complete condition for a group homomorphism of a compact Lie group with an arbitrarily given left invariant Riemannian metric into another Lie group with a left invariant metric to be a harmonic map, and then obtain a necessary and sufficient condition for a group homomorphism of (SU(2), g) with a left invariant metric g into the Heisenberg group (H, $h_0$) to be a harmonic map.

Scalable Data Visualization with Various Functional Representations (다양한 함수를 이용한 확장성 있는 데이터 가시화)

  • Jang, Yun
    • Proceedings of the Korean Information Science Society Conference
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    • 2012.06c
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    • pp.413-414
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    • 2012
  • Currently the amount and variety of data being generated is unprecedented and dramatically changes the way individuals, groups, and societies act and make decisions. Visualization is one of the most important commonly used methods of analyzing and interpreting digital assets and the interactive environments are necessary to enable effective discovery and decision making. In this paper we present several examples and approaches to scalable functional representations and interactive visualization and analysis. The functional representations provide us unified, compact, continuous, multi-scale, and compressed representations in the data domain.

Effects of Polyphosphate on Skin Wound Healing in Rabbits (토끼 피부창상 치유에 있어서 Polyphosphate의 효과)

  • 이광인;한정희;채수경;김홍렬;이창훈;정성목;서강문
    • Journal of Veterinary Clinics
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    • v.20 no.2
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    • pp.198-206
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    • 2003
  • The purpose of the present study was to investigate the effect of polyphosphate on healing of skin wound in rabbits. Four skin wounds of 8mm in diameter were induced bilaterally(4 wounds/rabbit) on the dorsolateral aspect of the trunk of 15 male New Zealand white rabbits. Ten percent polyphosphate(poly P) type 25, 10% poly P type 35, 10% poly P type 25+10% poly P type 35 and 0.85% sterile saline solution were applied on the wound area and examined grossly and histopathologically. The rate of wound contraction and histopathological changes after poly P application on the skin wound were investigated. In gross findings, the wound contraction rates of 10% poly P 25 group were significantly decreased from day 2 to day 7 after operation than those of 0.85% sterile saline solution treated group (p < 0.01). Although the hemorrhage and inflammation were observed on days 3, 6 and 9 after operation in all groups, but in 10% poly P 25 was gradually decreased. Revascularization and reepithelialization were seen 3, 6 and 9 days after operation in all groups, especially in 10% poly P 25 was formed completely on 9 days. Fibroplasia were seen 3. 6 and 9 days after operation in all groups, especially in 10% poly P 25 was compact than other groups on 9 days. The results suggested that polyphosphate, especially 10% poly P 25 would be effective on healing of skin wound in rabbits through decrease of would contraction rate, increase of revascularization, reepithelialization and fibroplasia.

The Effect of the UV irridation on the Cornea (UV조사가 각막에 미치는 영향)

  • Kim, Douk Hoon;Mun, Jung Hak
    • Journal of Korean Ophthalmic Optics Society
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    • v.1 no.2
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    • pp.19-35
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    • 1996
  • This study was performed on the mouse to estimate the effect of UV radiation on the cornea in UV clean bench by LM & SEM. The results are as follows In the control groups, The cornea tissue have relatively compact and each layer have well identify, and the thick of cornea have constant. In the increasing experimental time, the experimental result have very different. The early experimental groups results have not severely degeneration. But, some substrate layer have a swelling and some epithelial tissue have not normal shape. The middle experimental groups results have very swelling of the stroma, the vacoule of some region the condensation of the epithelium, and the irregular arrangement of the endothelium. The last experimental groups results have shirinking of cornea tissue, the swelling and vacoule of the end endothelium, the partially disruption of epithelium, the irregular thick of the corneal tissue.

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Zoom Lens Design for a 10x Slim Camera using Successive Procedures

  • Park, Sung-Chan;Lee, Sang-Hun
    • Journal of the Optical Society of Korea
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    • v.17 no.6
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    • pp.518-524
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    • 2013
  • This study presents a new design method for a zoom lens, in which real lens groups are designed successively to combine to form a lens modules zoom system. The lens modules and aberrations are applied to the initial design for a four-group inner-focus zoom system. An initial design with a focal length range of 4.2 to 39.9 mm is derived by assigning the first-order quantities and third-order aberrations to each module along with the constraints required for optimum solutions. After obtaining the lens module zoom system, the real lens groups are successively, not separately, designed to get a zoom lens system. Compared to the separately designed real lens groups, this approach can give a better starting zoom lens and save time. The successively designed groups result in a zoom system that satisfies the basic properties of the zoom system consisting of the original lens modules. In order to have a slim system, we directly inserted the right-angle prism in front of the first group. This configuration resulted in a compact zoom system with a depth of 12 mm. The finally designed zoom lens has an f-number of 3.5 to 4.5 and is expected to fulfill the requirements for a mobile zoom camera having high zoom ratio of 10x.

Ultra-Compact Zoom Lens Design for Phone Camera Using Hybrid Lens System (복합렌즈계를 이용한 폰 카메라용 초소형 줌렌즈 설계)

  • Park, Sung-Chan;You, Byoung-Taek
    • Korean Journal of Optics and Photonics
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    • v.19 no.5
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    • pp.349-359
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    • 2008
  • For an inner-focusing 3-groups zoom lens system, this study suggests a new initial design method which applies the process that changes thin lenses into thick ones effectively and quickly, using the hybrid lens system(thin lens+thick lens). In other words, the hybrid lens system is the semi-automatic design process that makes the thin lens of one group change into a thick one while the other groups are composed of thin lenses. Keeping the total power of the system fixed, the power of each group and the distance between principal planes can be fixed. Of course, the other groups composed of thin lenses could be changed into thick lenses sequentially by this process. This design conception results in the 1/4" 5 M inner-focusing 3-groups 2x zoom lens system satisfying the specifications and performances of zoom lens for phone cameras. Also aspherization on lens elements of glass and plastic material enhanced the resolution and reduced the lens size. As a result, we have an ultra-compact inner-focusing 3-groups 2x zoom lens system for a phone camera, with a slim size with TTL of 9.8 mm.

The Study of Reaction Bonded Silicon Nitride Fabricated Under Static Nitrogen Pressure (일정 질소압에서 제조된 반응결합 질화규소에 관한 연구)

  • Choi, Myoung-Je;Roh, Tae-Wook;Park, Chan;Park, Dong-Soo;Kim, Hai-Doo
    • Journal of the Korean Ceramic Society
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    • v.37 no.5
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    • pp.505-510
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    • 2000
  • In this investigation, we fabricated RBSN (Reaction Bonded Silicon Nitride) using the static nitriding system which could be advantageous for commercialization. Firstly, Si compacts of different sizes were made, and then nitridation rates were investigated as a function of added static gas pressure. The reaction schedule was obtained by pre-experiments. In case of small samples, the variation of ${\alpha}$, ${\beta}$ phases between the inside and the outside region of the specimens was examined after the samples were nitrided under 1 bar and 1.5 bar reaction pressure. On the other hand, large samples of Si compact with the size of 36 mm for diameter and 23 mm for thickness were nitrided for 26 hours of the total nitridation time, which showed a complete and homogeneous nitriding reaction from the outside to the inside of the samples, although the time was considerably shorter than that needed for convertional nitridation. Nitridation rates obtained at the early stage of reaction were proportional to the reaction gas pressures. The sequences of the nitridation reaction with the thickness were as follows 1) the outside, 2) the inside and 3) the intermediate area of the specimen. These results wer eobtained from the coloration of cross sectioned specimens that had various nitridation rates. Total nitriding reaction kinetics was controlled by chemical reaction, not by diffusion of the nitrogen gas.

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Zoom lens design for compact digital camera using lens modules (렌즈모듈을 이용한 컴팩트 디지털 카메라용 줌 렌즈 설계)

  • Park, Sung-Chan;Lee, Sang-Hun
    • Korean Journal of Optics and Photonics
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    • v.16 no.1
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    • pp.34-42
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    • 2005
  • This paper presents the optimum initial design containing the first and third order properties of the three-group zoom system using lens modules, and the real lens design of the system. The optimum initial design with focal length range of 4.3 mm to 8.6 mm is derived by assigning appropriate first and third order quantities to each module along with the specific constraints required for the system. An initial real lens selected for each group has been designed to match its focal length and the first orders into those of the each lens modules, and then combined to establish an actual zoom system by adjusting the air space between the groups at all zoom positions. The combination of the separately designed groups results in a system which satisfies the first order properties of the zoom system composed of the original lens modules. As a result, by residual aberration correction, we could obtain a zoom system useful in compact digital zoom cameras and mobile phone cameras employing the rear focus method.