• Title/Summary/Keyword: multi forming

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MULTI-FREQUENCY RADIO OBSERVATIONS OF MOLECULAR CLOUDS IN THE IMMEDIATE VICINITIES OF HB3 (초신성 잔해 HB3와 인접 분자운의 다파장 전파관측)

  • KIM KWANG-TAE;LEE CHANG-WON
    • Publications of The Korean Astronomical Society
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    • v.13 no.1 s.14
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    • pp.149-166
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    • 1998
  • The structure and environments of the molecular clouds near the SNR $HB3(G132.7\pm1.3)$ are studied. The molecular complex which is located at the southern rim of HB3 was proposed by former investigators as the one interacting with HB3. This complex region of $2^{\circ}\times2^{\circ}\;at\;l=133^{\circ}$ has been observed at $^{12}CO,\;^{13}CO,\;J=1-0\;at\;a\;1'$, resolution with the 14-m radio telescope at Taeduk Radio Astronomy Observatory. We have reached to the following four conclusions. The possibility that these molecular complex and HB3 are interacting with each other cannot be supported with any of our data. The morphologies of the two show no similarities. Neither particular features for the interaction are found in the CO lines. The hypothetical 'Molecular wall' which was expected to exist on the northwestern rim of HB3 as a cause for the noncircular morphology of HB3 is turned out to be nonexistent in CO. The molecular complex which resembles a 'bar' at a low resolution is now resolved into a U-shaped shell. It seems that the U-shape is consist of two independent components. No peculiarities, such as unseen masses or bright stars capable of forming HlI regions, are found within the U-shape region. The total mass included in the complex is estimated to be $M_{total}\;=\;2.9\~8.4\times10^5\;M_\bigodot$, which is in good agreement with previous observations within errors. Considering about 12 clumps distinguishable within the complex, the total mass implies that masses of each of clumps are on the order of $10^4\;M_\bigodot$, which makes these good objects for further studies in relation to star-formation. Especially the clumps associated with W3 are worthy for more high resolution observations for better understanding of astrophysical phenomenon ongoing in them.

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An Analysis on Influences of Seasonal and Tidal Changes to Outfall Design and Management (조석이 방류관의 설계 및 운영에 미치는 영향 분석)

  • Kim, Ji-Yeon;Lee, Joong-Woo
    • Journal of Navigation and Port Research
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    • v.28 no.3
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    • pp.259-268
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    • 2004
  • For the last years, it has become hot issue such as disposal of the treated wastewater, which caused by increment of a population and industrial development at the coastal areas. The ocean outfall system discharges primary or secondary treated effluent into coastline or at the deep water, or between these two. The effluent, which has a density similar to that of fresh water, rises to the see, surface forming plume or jet, together with entraining the surrounding salt water and becomes very dilute. This paper deals ocean outfall design which effects to decision-making about marine environment management and wastewater treatment. In order to make predictions of dilution of discharged water and the trajectory of a plume, CORMIX has been used considering several elements including a seasonal and tidal changes. These solutions are strung together to provide basic data and general drawings for effective management of outfall.

A Study on the Formation of Working-Class Residential Areas md the Transformation of Housing Types of Firenze, Italy (이탈리아 피렌체의 서민주거지역의 형성과 주거형식의 변화에 관한 연구)

  • Sohn, Sei-Kwan
    • Journal of architectural history
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    • v.13 no.2 s.38
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    • pp.21-38
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    • 2004
  • This study provides a descriptive and analytical account of major aspects of urban development and transformation of housing types of Italian Firenze from the 13th century to the 19th century. It is a typo-morphological depiction of urban spatial structure of the extraordinary city, Firenze, the center of Italian Renaissance. And this study has proceeded on the assumption that the evolving form of the urban structure and housing types cannot be understood without reference to the larger context of political, economic, and social life. Based on these backgrounds, the purpose of this study is threefold: to provide a comprehensive discussion of general characteristics of urban spatial structure of Firenze, and to explain the process of formation of working-class neighborhoods by constructing new city wall in later 13th century, and to discuss transformation of housing types of the working-class neighborhood with understanding the mechanism of existence of housing in the newly formed residential neighborhoods. The development of residential neighborhoods was pursued by 'planned' manner through forming square-shaped blocks, and characterized by the subdivision of larger properties into standardized building lots for the construction of houses. On the bases of documentary evidences, several ecclesiastical institutions are identified as the agents of a distinctive type of development. While the institutions did the major role for developing lands, the construction of houses was done by small scale construction agents with moderate amount of properties. The major housing type of working-class neighborhoods of Firenze has been the 'casa a schiera' characterized by the form of narrow front and long depth. The type was generalized by the newly formed middle and working-class of Firenze which grew their body very rapidly, Even though the type assumed very uniform in its fen there were many variations. And through passing time, the casa a schiera developed to be multi-family housing, and the level of variation became deepen. Eventually, transformation of housing type of Firenze was ended by appearance of the 'casa in linea', which was very similar to modern apartment in its spatial organization.

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Multiculturalism and Socio-Spatial Segregation of Honolulu in the 1920s (1920년대 호놀룰루의 다문화주의와 집단간 사회-공간적 분리)

  • Lee, Young-Min
    • Journal of the Korean Geographical Society
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    • v.42 no.5
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    • pp.675-690
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    • 2007
  • It has been widely believed that the ethnic relations in Honolulu and Hawai'i in the early twentieth century were little associated with racist ideology because the white race was minority in terms of the racial composition. In reality, however, the racial and ethnic issues have played a major role in forming the past and present relations among ethnic groups. This study shows that the white-supremacy ideology exerted a strong influence on minority groups in Honolulu throughout the immigration and settling-down process, as much as in the mainland U.S. Clear occupational stratification and residential segregation among the ethnic groups in Honolulu represented almost the same situation as in mainland cities. The social segregation and spatial propinquity of their residential neighborhoods facilitated the construction of dichotomized identity: "Local" versus "Haole". Such transformed identities were a product of on-going inter-ethnic negotiation process embedded in the non-white multi-ethnic neighborhoods.

Characteristics and response of mouse bone marrow derived novel low adherent mesenchymal stem cells acquired by quantification of extracellular matrix

  • Zheng, Ri-Cheng;Kim, Seong-Kyun;Heo, Seong-Joo;Koak, Jai-Young;Lee, Joo-Hee;Park, Ji-Man
    • The Journal of Advanced Prosthodontics
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    • v.6 no.5
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    • pp.351-360
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    • 2014
  • PURPOSE. The aim of present study was to identify characteristic and response of mouse bone marrow (BM) derived low-adherent bone marrow mesenchymal stem cells (BMMSCs) obtained by quantification of extracellular matrix (ECM). MATERIALS AND METHODS. Non-adherent cells acquired by ECM coated dishes were termed low-adherent BMMSCs and these cells were analyzed by in vitro and in vivo methods, including colony forming unit fibroblast (CFU-f), bromodeoxyuridine (BrdU), multi-potential differentiation, flow cytometry and transplantation into nude mouse to measure the bone formation ability of these low-adherent BMMSCs. Titanium (Ti) discs with machined and anodized surfaces were prepared. Adherent and low-adherent BMMSCs were cultured on the Ti discs for testing their proliferation. RESULTS. The amount of CFU-f cells was significantly higher when non-adherent cells were cultured on ECM coated dishes, which was made by 7 days culturing of adherent BMMSCs. Low-adherent BMMSCs had proliferation and differentiation potential as adherent BMMSCs in vitro. The mean amount bone formation of adherent and low-adherent BMMSCs was also investigated in vivo. There was higher cell proliferation appearance in adherent and low-adherent BMMSCs seeded on anodized Ti discs than machined Ti discs by time. CONCLUSION. Low-adherent BMMSCs acquired by ECM from non-adherent cell populations maintained potential characteristic similar to those of the adherent BMMSCs and therefore could be used effectively as adherent BMMSCs in clinic.

Star-formation Properties of High-redshift (z~1) Galaxy Clusters Connected to the Large-scale Structure

  • Lee, Seong-Kook;Im, Myungshin;Hyun, Minhee;Park, Bomi;Kim, Jae-woo;Kim, Dohyung;Kim, Yongjung
    • The Bulletin of The Korean Astronomical Society
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    • v.42 no.2
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    • pp.40.2-40.2
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    • 2017
  • At local, majority of galaxies in the dense environment, such as galaxy cluster, are red and quiescent with little star-formation (SF) activity. However, a different picture emerges as we go to high redshift: (1) there exist non-negligible fraction of galaxies still forming stars actively even in dense environment, and (2) there is a significant cluster-by-cluster variation in the SF properties, such as quiescent galaxy fraction. In this presentation, we show the results of our study about the variation of quiescent galaxy fraction among high-redshift (z~1) galaxy clusters, based on the multi-object spectroscopic (MOS) observation with IMACS on the Magellan telescope. Our main result is that galaxy clusters which are connected with significant large-scale structure (LSS), well beyond the cluster scale, are more active in their SF activity, i.e., the quiescent galaxy fraction for these clusters is lower compared to the clusters which are detached from LSS.

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The Grey Box of Technoscientific Practices: Laboratory as a Heterotopic Space where In/visible Collaborations Take Place (과학적 실행의 회색상자(grey box): 비/가시적 협력의 헤테로토피아(heterotopia)로서의 실험실 공간)

  • Lee, June Seok
    • Journal of Science and Technology Studies
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    • v.13 no.1
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    • pp.1-39
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    • 2013
  • How would technoscientists collaborate in their technoscientific practices? Based on the ethnographic research done at NRI(Neuroscience Research Institute), this research shows how collaboration occurs in/outside the interdisciplinary laboratory. As previous studies show, collaboration makes researches possible that otherwise would have been impossible. Korean technoscientists who are situated in the scientific periphery, practice contextualized collaboration in their labs. These collaborations are invisible before opening the black box of the lab. But it acquires visibility after certain incidents such as collaborations, debates and discussions, malfunctioning of the instruments, and networking with other actors occur. These networks again become invisible after the certain incidents end. However these blackboxing and whiteboxing (opening the blackbox) processes occur simultaneously in various levels, it is almost impossible to identify them separately. In real technoscientific practices, blackboxing and whiteboxing do not occur distinctively. They almost always occur at the same time on multi-layered levels, hence forming the 'grey box' of technoscientific practices. Lastly, collaborations inside laboratory have in/visible features, because laboratories function as Foucauldian heterotopias.

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FUNS - Filaments, the Universal Nursery of Stars. I. Physical Properties of Filaments and Dense Cores in L1478

  • Chung, Eun Jung;Kim, Shinyoung;Soam, Archana;Lee, Chang Won
    • The Bulletin of The Korean Astronomical Society
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    • v.43 no.1
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    • pp.45.1-45.1
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    • 2018
  • Formation of filaments and subsequent dense cores in ISM is one of the essential questions to address in star formation. To investigate this scenario in detail, we recently started a molecular line survey namely 'Filaments, the Universal Nursery of Stars (FUNS)' toward nearby filamentary clouds in Gould Belt using TRAO 14m single dish telescope equipped with a 16 multi-beam array. In the present work, we report the first look results of kinematics of a low mass star forming region L1478 of California molecular cloud. This region is found to be consisting of long filaments with a hub-filament structure. We performed On-The-Fly mapping observations covering ~1.1 square degree area of this region using C18O(1-0) as a low density tracer and 0.13 square degree area using N2H+(1-0) as a high density tracer, respectively. CS (2-1) and SO (32-21) were also used simultaneously to map ~290 square arcminute area of this region. We identified 10 filaments applying Dendrogram technique to C18O data-cube and 13 dense cores using FellWalker and N2H+ data set. Basic physical properties of filaments such as mass, length, width, velocity field, and velocity dispersion are derived. It is found that filaments in L~1478 are velocity coherent and supercritical. Especially the filaments which are highly supercritical are found to have dense cores detected in N2H+. Non-thermal velocity dispersions derived from C18O and N2H+ suggest that most of the dense cores are subsonic or transonic while the surrounding filaments are transonic or supersonic. We concluded that filaments in L~1478 are gravitationally unstable which might collapse to form dense cores and stars. We also suggest that formation mechanism can be different in individual filament depending on its morphology and environment.

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Modeling of surface roughness in electro-discharge machining using artificial neural networks

  • Cavaleri, Liborio;Chatzarakis, George E.;Trapani, Fabio Di;Douvika, Maria G.;Roinos, Konstantinos;Vaxevanidis, Nikolaos M.;Asteris, Panagiotis G.
    • Advances in materials Research
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    • v.6 no.2
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    • pp.169-184
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    • 2017
  • Electro-Discharge machining (EDM) is a thermal process comprising a complex metal removal mechanism. This method works by forming of a plasma channel between the tool and the workpiece electrodes leading to the melting and evaporation of the material to be removed. EDM is considered especially suitable for machining complex contours with high accuracy, as well as for materials that are not amenable to conventional removal methods. However, several phenomena can arise and adversely affect the surface integrity of EDMed workpieces. These have to be taken into account and studied in order to optimize the process. Recently, artificial neural networks (ANN) have emerged as a novel modeling technique that can provide reliable results and readily, be integrated into several technological areas. In this paper, we use an ANN, namely, the multi-layer perceptron and the back propagation network (BPNN) to predict the mean surface roughness of electro-discharge machined surfaces. The comparison of the derived results with experimental findings demonstrates the promising potential of using back propagation neural networks (BPNNs) for getting a reliable and robust approximation of the Surface Roughness of Electro-discharge Machined Components.

International Legislative Trends on Responsible Business Conduct (RBC) and its Implications on Policy (기업책임경영(RBC)의 국제입법동향과 정책적 시사점)

  • AHN, Keon-Hyung;JOE, In-Ho;KWON, Hee-Hwan
    • THE INTERNATIONAL COMMERCE & LAW REVIEW
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    • v.75
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    • pp.199-224
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    • 2017
  • As Multi-National Enterprises expanded their investments to foreign countries, numerous controversies and disputes arose from their negative impacts, such as violations of human rights and damage to the environment of the host countries. In response, International Organizations such as the OECD have considered various ways to prevent these negative impacts and search for more efficient dispute resolution methods. It is recognized that the OECD Guideline is one of the tools they created for this purpose. The OECD Guideline is contrastable from Corporate Social Responsibility (CSR) initiatives which are regarded as a corporation's charity activities apart from their core business functions. However, Responsible Business Conduct (RBC) like the OECD Guideline can be understood as a concept moving forward from CSR, due to its requirements that corporations carry out their duties in a responsible manner within the field of their core business, such as tax, global supply chain or consumer protection. RBC which is binding in nature, has even been implemented through legislation in developed countries such as the USA, France, Switzerland, and the UK. The discussion in Korea, however, has not reached that level. Discussions for legislation center singularly on CSR efforts, with a dialogue only recently forming around the topic of legislation concerning RBC. Small and medium sized enterprises (SMEs) who lack certain financial and other resources to adequately develop RBC initiatives may find this more obstacles to implementation through legislated RBC, than if it were presented in Korea through other means. It's necessary to admit that RBC is a critical issue in international business. However, time is required to consider its application directly to SMEs.

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