• 제목/요약/키워드: local star

검색결과 229건 처리시간 0.027초

효과적 지식창출을 위한 조직능력 요건: 퀴놀론계 항생제 개발 사례를 중심으로 (Organizational Capabilities for Effective Knowledge Creation: An In-depth Case Analysis of Quinolone Antibacterial Drug Discovery Process)

  • 이춘근;김인수
    • 지식경영연구
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    • 제2권1호
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    • pp.109-132
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    • 2001
  • The purpose of this article is to develop a dynamic model of organizational capabilities and knowledge creation, and at the same time identify the organizational capability factors for effective knowledge creation, by empirically analyzing the history of new Quinolone antibacterial drug compound (LB20304a) discovery process at LG, as a case in point. Major findings of this study are as follows. First, in a science-based area such as drug development, the core of successful knowledge creation lies in creative combination of different bodies of scientific explicit knowledge. Second, the greater the difficulty of learning external knowledge, the more tacit knowledge is needed for the recipient firm to effectively exploit that knowledge. Third, in science-based sector such as pharmaceutical industry, the key for successful knowledge creation lies in the capability of recruiting and retaining star scientists. Finally, for effective knowledge creation, a firm must keep its balance among three dimensions of organizational capabilities: local, process, architectural capabilities.

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실내 환경에서의 경비로봇용 주행시스템 (A Navigation System for a Patrol Robot in Indoor Environments)

  • 최병욱;이영민;박정호;신동관
    • 로봇학회논문지
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    • 제1권2호
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    • pp.117-124
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    • 2006
  • In this paper, we develope the navigation system for patrol robots in indoor environment. The proposed system consists of PDA map modelling, a localization algorithm based on a global position sensor and an automatic charging station. For the practical use in security system, the PDA is used to build object map on the given indoor map. And the builded map is downloaded to the mobile robot and used in path planning. The global path planning is performed with a localization sensor and the downloaded map. As a main controller, we use PXA270 based hardware platform in which embedded linux 2.6 is developed. Data handling for various sensors and the localization algorithm are performed in the linux platform. Also, we implemented a local path planning algorithm for object avoidance with ultra sonar sensors. Finally, for the automatic charging, we use an infrared ray system and develop a docking algorithm. The navigation system is experimented with the two-wheeled mobile robot using North-Star localization system.

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Molecular gas content of HI Monsters

  • 정애리;이철종;윤민수
    • 천문학회보
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    • 제38권1호
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    • pp.33.2-33.2
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    • 2013
  • We present 12CO ($J=1{\rightarrow}0$) observations of a set of local galaxies (0.04 < z < 0.08) with a large cool gas reservoir, dubbed "HI Monsters". The data were obtained using the Redshift Search Receiver (RSR) on the Five College Radio Astronomy Observatory (FCRAO) 14 m telescope. The sample consists of 20 galaxies with $M_{HI}$ > $3{\times}10^{10}M_{\odot}$ identified by the ALFALFA survey and 8 additional objects with comparable HI mass from a separate LSB galaxy study ($M_{HI}$ > $1.5{\times}10^{10}M_{\odot}$). Our sample selection is purely based on the amount of neutral hydrogen in galaxies, thereby providing a chance to study how atomic and molecular gas relate to each other in these extremely HI-rich systems. We have detected CO in 15 out of 20 ALFALFA selected HI Monsters and 4 out of 8 LSB HI Monsters. We present the global molecular gas properties of the sample and discuss how their molecular gas properties correlate with their star formation activities.

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에너지 균등 하이브리드 WSN 프로토콜 기반 국지 기상 관측 시스템 (A Weather Monitoring System for Local Area Using an Energy-balanced Hybrid WSN Protocol)

  • 이형봉;정태윤
    • 대한임베디드공학회논문지
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    • 제9권4호
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    • pp.193-203
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    • 2014
  • This paper implements a weather monitoring system based on wireless sensor network. The wireless sensor network protocol proposed in this paper adopts a TDMA styled MAC. The protocol is designed to balance the energy consumption among sensor nodes. Other purposes of the protocol are to avoid the hidden terminal problem in 2-hop star topology, and to allow a CSMA styled communication in a given time slot to support emergent messages. Also, this paper develops the hardware of sensor node, gateway and electric generator based on solar and windy energy. The test results on the implemented system show that the time slot of each node is shifted in circular manner to balance the waiting time for transmission, and the reliability of wireless communication is over 99%.

THE COSMIC EVOLUTION OF LUMINOUS INFRARED GALAXIES: STRONG INTERACTIONS/MERGERS OF GAS-RICH DISKS

  • SANDERS D. B.
    • 천문학회지
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    • 제36권3호
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    • pp.149-158
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    • 2003
  • Deep surveys at mid-infared through submillimeter wavelengths indicate that a substantial fraction of the total luminosity output from galaxies at high redshift (z > 1) emerges at wavelengths 30 - 300${\mu}m$. In addition, much of the star formation and AGN activity associated with galaxy building at these epochs appears to reside in a class of luminous infrared galaxies (LIGs), often so heavily enshrouded in dust that they appear as 'blank-fields' in deep optical/UV surveys. Here we present an update on the state of our current knowledge of the cosmic evolution of LIGs from z = 0 to z $\~$ 4 based on the most recent data obtained from ongoing ground-based redshift surveys of sources detected in ISO and SCUBA deep fields. A scenario for the origin and evolution of LIGs in the local Universe (z < 0.3), based on results from multiwavelength observations of several large complete samples of luminous IRAS galaxies, is then discussed.

A Pilot Study for CO of BUDHIES Galaxies

  • 정애리
    • 천문학회보
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    • 제37권2호
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    • pp.87.1-87.1
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    • 2012
  • The fraction of blue galaxies in clusters is found to dramatically increase with redshift. This trend has been known as the Butcher-Oemler (B-O) effect which implies a significant evolution among the cluster galaxy population with time. It has been proposed that the blue galaxies in B-O clusters are at their last stage of star formation, probably using up the gas, which then might have evolved into red and passive cluster galaxies as found in the Local Universe. To test this hypothesis and ultimately to understand the evolution of cluster galaxy population as a function of redshift, we have embarked a multi-wavelength study of two carefully selected galaxy clusters at z~0.2 where the B-O effect becomes first noticeable. In this talk, I will introduce the Blind Ultra-deep Distant HI Environmental Survey (BUDHIES) on those two clusters and relevant multi-wavelength observations. Also, I will present the preliminary results of our recent Nobeyama CO observations of two galaxies selected among the BUHDIES sample.

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원자로 냉각재 펌프의 과도 상태의 유동 및 열전달 해석 연구 (Flow and Heat Transfer Analysis of Reactor Coolant Pump in Transient Conditions)

  • 허남건;김성원;유기풍;김승태
    • 유체기계공업학회:학술대회논문집
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    • 유체기계공업학회 1999년도 유체기계 연구개발 발표회 논문집
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    • pp.245-251
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    • 1999
  • The structural analysis of a reactor coolant pump(RCP) of a nuclear power plant is very important for the safety assessment of the plant. Accurate boundary conditions for the heat transfer coefficient are required for reliable thermal stress analysis of the pump casing, especially in transient operations of the pump since the coolant properties are largely dependent on operational conditions. In the present study, a 3D mixed flow type coolant pump was modeled from the RCP drawings and analyzed in the steady state and number of transient flow conditions by using a commercial code STAR-CD. From the result of the computation, it is seem that the average heat transfer coefficients for the cases considered are found to be the suggested values of the manufacturer, Westinghouse Energy System. The unevenness in local heat transfer coefficients, however, is found to be considerable so that the use of average heat transfer coefficients in all boundaries might not give reliable thermal stresses.

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PLANK PROBLEMS, POLARIZATION AND CHEBYSHEV CONSTANTS

  • Revesz, Szilard-Gy.;Sarantopoulos, Yannis
    • 대한수학회지
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    • 제41권1호
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    • pp.157-174
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    • 2004
  • In this work we discuss "plank problems" for complex Banach spaces and in particular for the classical $L^{p}(\mu)$ spaces. In the case $1\;{\leq}\;p\;{\leq}\;2$ we obtain optimal results and for finite dimensional complex Banach spaces, in a special case, we have improved an early result by K. Ball [3]. By using these results, in some cases we are able to find best possible lower bounds for the norms of homogeneous polynomials which are products of linear forms. In particular, we give an estimate in the case of a real Hilbert space which seems to be a difficult problem. We have also obtained some results on the so-called n-th (linear) polarization constant of a Banach space which is an isometric property of the space. Finally, known polynomial inequalities have been derived as simple consequences of various results related to plank problems.

Environmental Dependence of High-redshift Galaxies in CFHTLS W2 Field

  • 백인수;임명신;김재우
    • 천문학회보
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    • 제43권2호
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    • pp.36.1-36.1
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    • 2018
  • Star formation activity of galaxies, along with color and morphology, show significant environmental dependence in local universe, where galaxies in dense environment tend to be more quiescent and redder. However, many studies show that such environmental dependence does not continue at higher redshifts beyond z~1. The question of how the environmental dependence of galactic properties have developed over time is crucial to understanding cosmic galactic evolution. By combining data from Canada-France-Hawaii Telescope Legacy Survey(CFHTLS), Infrared Medium-Deep Survey(IMS), and other surveys, the photometric redshifts of galaxies in CFHTLS W2 field were estimated by fitting spectral energy distribution. The distribution of galaxies was mapped in redshift bins of 0.05 interval from 0.6 to 1.4. For each redshift bin, the number density was mapped. The galaxies in high density regions were grouped into clusters using friend-of-friend method. The color of galaxies were analyzed to study the correlation with redshift as well as environmental difference between field galaxies and cluster member galaxies.

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Environmental Dependence of Galaxy Properties in the Framework of the Cosmic Web

  • Hwang, Ho Seong;Park, Changbom;Pichon, Christophe;Kraljic, Katarina;Song, Hyunmi;Laigle, Clotilde
    • 천문학회보
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    • 제43권2호
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    • pp.37.3-38
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    • 2018
  • There is growing observational evidence from several galaxy surveys that the cosmic web plays an important role in shaping galaxy properties in addition to the effects of isotropic environment including local density. To study the distinctive effects of anisotropic and isotropic environments on galaxy properties, we simultaneously examine the galaxy properties as functions of anisotropic and isotropic environments using the SDSS data. We focus on galaxy morphology and star formation/nuclear activity, and find the importance of both anisotropic and isotropic environments in determining galaxy properties.

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