• Title/Summary/Keyword: Continuum distribution

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대관령 가축시험장 지양에 있어서의 몇 개의 방목지에 대한 생태학적 연구

  • 박봉규
    • Journal of Plant Biology
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    • v.5 no.3
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    • pp.1-4
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    • 1962
  • A district (Sae-Bong) and 13 district (Sae-Jang Dong) grassland could be divided into four type of Community: Miscanthus-Community, Glyceria-Community, Festuca-Community, and Plantago-Community. Chose 17 or 20 stands from each district A and B and calculated F.I. with the Curtis method, finally vegetational continuum could be recognized while discontinuous boundary line of species distribution could not be recognized. As a rule the distributional curve of species was binominal or bell shaped. It had a distribution pattern peculiar to itself. As to the relationship of cattles' density and vegetation. I found that the tendency of F.I. moving from small to large paralleled that of disturbance-pressure from weak to strong. Found that the more the steepness of environmental factors be controlled by a rule " from large to small", the more F.I. might be controlled by a rule "from small to large" and that pH, soil-moisture-content, loss on ignition was in relation with the steepness. with the steepness.

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Analysis on the Flow Effect of the Twisted Nematic liquid Crystals (Twisted Nematic(TN) 액정에서의 흐름효과 해석)

  • Kim, Hoon;Park, Woo-Sang
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2005.07a
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    • pp.76-78
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    • 2005
  • We coupled fluid balance equation and director balance equation from Ericksen-Leslie's continuum theory and observed the motion of Twisted Nematic (TN) Liquid Crystals. We simulated flow velocity distribution and director distribution. We interpreted the dynamic response characteristic caused by the flow. As the result of the simulation, We could see the flow effect. And this flow caused abnormal twist to 4msec in switching off state. We could prove that this abnormal twist is a direct cause of optical bounce phenomenon known well until now with the result of simulation.

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Effects of porosity models on static behavior of size dependent functionally graded beam

  • Hamed, Mostafa A.;Sadoun, Ayman M.;Eltaher, Mohamed A.
    • Structural Engineering and Mechanics
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    • v.71 no.1
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    • pp.89-98
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    • 2019
  • In this study, the mechanical bending behaviors of functionally graded porous nanobeams are investigated. Four types of porosity which are, the classical power porosity function, the symmetric with mid-plane cosine function, bottom surface distribution and top surface distribution are proposed in analysis of nanobeam for the first time. A comparison between four types of porosity are illustrated. The effect of nano-scale is described by the differential nonlocal continuum theory of Eringen by adding the length scale into the constitutive equations as a material parameter comprising information about nanoscopic forces and its interactions. The graded material is designated by a power function through the thickness of nanobeam. The beam is simply-supported and is assumed to be thin, and hence, the kinematic assumptions of Euler-Bernoulli beam theory are held. The mathematical model is solved numerically using the finite element method. Numerical results show effects of porosity type, material graduation, and nanoscale parameters on the static deflection of nanobeam.

Microhabitat Characteristics Determine Fish Community Structure in a Small Stream (Yudeung Stream, South Korea)

  • Choi, Jong-Yun;Kim, Seong-Ki;Kim, Jeong-Cheol;Lee, Hyeon-Jeong;Kwon, Hyo-Jeong;Yun, Jong-Hak
    • Proceedings of the National Institute of Ecology of the Republic of Korea
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    • v.2 no.1
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    • pp.53-61
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    • 2021
  • Distribution of fish community depends largely on environmental disturbance such as habitat change. In this study, we evaluated the impact of environmental variables and microhabitat patch types on fish distribution in Yudeung Stream at 15 sites between early May and late June 2019. We used non-metric multidimensional scaling to examine the distribution patterns of fish in each site. Gnathopogon strigatus, Squalidus gracilis majimae, Zacco koreanus, and Zacco platypus were associated with riffle and boulder areas, whereas Iksookimia koreensis, Acheilognathus koreensis, Coreoleuciscus splendidus, Sarcocheilichthys nigripinnis morii, and Odontobutis interrupta were associated with large shallow areas. In contrast, Cyprinus carpio, Carassius auratus, Lepomis macrochirus, and Micropterus salmoides were found at downstream sites associated with large pool areas, sandy/clay-bottomed areas, and vegetated areas. On the basis of these results, we suggest that microhabitat patch types are important in determining the diversity and abundance of fish communities, since a mosaic of different microhabitats supports diverse fish species. As such, microhabitat patches are key components of freshwater stream ecosystem heterogeneity, and a suitable patch composition in stream construction or restoration schemes will support ecologically healthy food webs.

Freeway Design Capacity Estimation through the Analysis of Time Headway Distribution (차두시간분포 분석을 통한 고속도로 설계용량 산정모형의 개발)

  • Kim, Jum San;Park, Chang Ho
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.26 no.2D
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    • pp.251-258
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    • 2006
  • This study is to develop an estimation method of freeway design capacity through the analysis of time headway distribution in continuum flow. Traffic flow-speed diagram and time headway distribution plotted from individual vehicle data shows: a) a road capacity is not deterministic but stochastic, b) time headway distribution for each vehicle speed group follows pearson type V distribution. The freeway design capacity estimation model is developed by determining a minimum time headway for capacity with stochastic method. The estimated capacity values for each design speed are lower when design speed ${\leq}80km/h$, and higher when design speed ${\geq}106km/h$ in comparison with HCM(2000)'s values. In addition, The distinguish difference is that this model leads flexible application in planning level by defining the capacity as stochastic distribution. In detail, this model could prevent a disutility to add a lane for only one excess demand in a road planning level.

The Current Status of 3D Printing Use in Fashion Industry and Utilization Strategies for Fashion Design Departments (패션 산업 내 3D 프린팅 사용 현황 및 패션디자인과 내의 활용방안)

  • Jeong, Hwa-Yeon
    • Journal of the Korea Fashion and Costume Design Association
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    • v.18 no.3
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    • pp.245-260
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    • 2016
  • This study explored cases of 3D printing utilization in domestic and overseas fashion industries, and presented utilization strategies for fashion design departments in universities in future by grasping characteristics of newly appearing distribution types through 3D printing. Cases of producing costumes using 3D printing in fashion industry comprised a bikini using the material of Nylon12 that continuum fashion demonstrated, innovative 3D costumes by Iris Van Herpen, Tweed Suit using the material that Chanel manufactured with 3D printing technology, but they were limited to experimental fashion works due to limitations of 3D printer material and printing size. On the other hand, in fashion accessories, with jewelry and shoes at the head of the list, MCM and Kipling also demonstrated bags using this technology, and Elvis Pompilio and Gabriela Ligenza demonstrated 3D printing hat products as well. Except the above, as in glasses and neckties utilizing 3D printing, owing to reduced limitations of time, size and material, 3D printing was found to be utilized in fashion accessories other than costumes. Recently there has been a new consumption and distribution structure coming up focusing on 3D printing technology. That is, in overseas countries, content platforms sharing products modeled by oneself has rapidly appeared, and in our country as well, funnypoly, a 3D content platform appeared in 2015. The appearance of these new types of distribution structures means that the common people can produce design contents, and we believe that it may bring about a change in the traditional way of distribution structure. To walk in step with this change, it is believed that it is necessary for fashion design departments to raise college faculty members who can educate 3D printing, develop curriculum to educate 3D printing, and develop experiential programs connected with middle and high schools.

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LARGE-SCALE [OIII] AND [CII] DISTRIBUTIONS OF THE LARGE MAGELLANIC CLOUD WITH FIS-FTS

  • Takahashi, A.;Yasuda, A.;Kaneda, H.;Kawada, M.;Kiriyama, Y.;Mouri, A.;Mori, T.;Okada, Y.;Takahashi, H.
    • Publications of The Korean Astronomical Society
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    • v.27 no.4
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    • pp.219-220
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    • 2012
  • We present the results of far-infrared spectroscopic observations of the Large Magellanic Cloud (LMC) with FIS-FTS. We covered a large area across the LMC, including 30 Doradus (30 Dor) and N44 star-forming regions, by 191 pointings in total. As a result, we detect the [OIII] and [CII] line emission as well as far-infrared dust continuum emission throughout the LMC. We find that the [OIII] emission is widely distributed around 30 Dor. The observed size of the distribution is too large to be explained by massive stars in 30 Dor, which are assumed to be enshrouded by clouds with the constant gas density estimated from the [OIII] line intensities. Therefore the surrounding structure is likely to be highly clumpy. We also find a global correlation between the [OIII] and the far-infrared continuum emission, suggesting that the gas and dust are well mixed in the highly-ionized region where the dust survives in clumpy dense clouds shielded from energetic photons. Furthermore we find that the ratios of [CII]/CO are as high as 110,000 in 30 Dor, and 45,000 even on average, while they are typically 6,000 for star-forming regions in our Galaxy. The unusually high [CII]/CO is also consistent with the picture of clumpy small dense clouds.

ASIAA EXTRAGALACTIC STUDY WITH THE SMA

  • MATSUSHITA SATOKI;MAO RUI-QING;MULLER SEBASTIEN;CHOU CHUEN- YI;SAWADA-SATOH SATOKO;TRUNG DINH-VAN;LIM JEREMY;HSIEH PEI-YING;PECK ALISON B.
    • Journal of The Korean Astronomical Society
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    • v.38 no.2
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    • pp.169-172
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    • 2005
  • We present CO(3-2), CO(2-1), and 230 GHz (1.3 mm) continuum images of nearby galaxies taken with the Submillimeter Array (SMA). Our main topic is to study the relation between higher-J molecular gas (e.g., CO J=3-2, 2-1) and nuclear activities (e.g., active galactic nuclei [AGNs] and starbursts). The nearby Seyfert 2 galaxy M51 shows strong CO(3-2) emission from the circumnuclear molecular gas, with an intensity twice as strong as that of the CO(1-0) emission. Strong CO(3-2) emission enhancement suggests that the circum nuclear molecular gas in M51 is warm and dense, which may be related to the AGN activities. Molecular gas in the nearby moderate starburst galaxy NGC 6946 is distributed along the large-scale bar or spiral arms and along the minibar, and the multi-J CO line images show very similar distribution to each other. For this galaxy, there is no clear enhancement in higher-J lines as seen in M51, which may be because NGC 6946 does not have clear AGN activities. Based on the results of these two galaxies, the physical conditions of the circum nuclear molecular gas may be related to the AGN activities. We also observed the nearby edge-on starburst galaxy NGC 3628 and the starburst/Seyfert composite galaxy NGC 4945 with the CO(2-1) line and 230 GHz (1.3 mm) continuum emission. These information will give us some hints for understanding the relation between nuclear activities and circum nuclear molecular gas and dust.

Molecular environments of a Planck Cold Clump: G108.8-00.8

  • Kim, Jungha;Lee, Jeong-Eun;Liu, Tie;Kim, Kee-Tae;Menten, Karl;Wu, Yuefang;Thompson, Mark;Yuan, Sheng
    • The Bulletin of The Korean Astronomical Society
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    • v.40 no.2
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    • pp.53.2-53.2
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    • 2015
  • We present preliminary results from a series of observations toward G108.8-00.8, which is one of Planck Cold Clumps and a promising candidate of massive prestellar cores. In the integrated intensity map of SCUBA 850 micron dust continuum emission, highly fragmented structures appear. These are distributed along one long filamentary structure seen in the CO 1-0 and 13CO 1-0 integrated intensity maps obtained with the PMO 13.7 m telescope. The northern part of the filament is divided into two parts, as seen in the CO 2-1, 13CO 2-1, and C18O 2-1 integrated intensity maps obtained with the CSO 10 m telescope. The observations of HCO+ 1-0, N2H+ 1-0, and HCN 1-0 with the IRAM 30 m telescope focus on the northern part of the CSO maps, which show a head-tail structure. NH3 (1,1) also shows similar distribution with IRAM maps. The depletion factors, derived by the comparison between the dust continuum and C18O 2-1 emission, varies from 1.5 to 6 over the region, suggesting different evolutionary status of each component. To study the chemical and physical environments of G108.8-00.8, more detailed analysis is in progress.

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OASIS Spectral Images of the Seyfert galaxy NGC 5728 (시이펏 은하 NGC 5728의 OASIS 분광 영상)

  • Hyung, Siek;Son, Dong-Hoon;Ferruit, Pierre;Lee, Woo-Baik
    • Journal of the Korean earth science society
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    • v.27 no.5
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    • pp.569-578
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    • 2006
  • The distribution and kinematic information of the continuum, $H{\alpha},\;H{\beta}$, [O III], & [N II] images based on spectroscopic data secured with the OASIS at the Hawaii CFHT 3.6m telescope have been analyzed to study the physical characteristics of NGC 5728. The three bright regions-northwestern knot, southeastern knot, and the nucleus-exist within a $15"{\times}12"$ sky area which seem to indicate gas flows along the northwestern or western direction from the nucleus. We find that the center of a 10" diameter ring is at the northwestern knot, not at the galactic center. To further analyze the formation mechanism of such a ring, the kinematics of the nucleus and knot have been studied and the central structure of the Active Galactic Nuclei has been investigated by comparing various emission images.