• Title/Summary/Keyword: Initial distribution

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Initial Size Distribution of the Milky Way Globular Clusters

  • Shin, Ji-Hye;Kim, Sung-Soo S.
    • The Bulletin of The Korean Astronomical Society
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    • v.35 no.2
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    • pp.35.1-35.1
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    • 2010
  • Unlike the initial mass function, the initial size distribution of globular cluster (GC) systems is not well known. We calculate the evolution of the mass function (MF), radial distribution (RD), and size distribution (SD) of the Galactic GC system. By comparing the results from this calculation and the present-day MF, RD, and SD of the Galactic GC system, we infer the initial SD of the GC system. We find that a Gaussian distribution of the half-mass radius and a Gaussian distribution of the half-mass to Jacobi radius ratio are the best-fit initial SDs of the Galactic GC system.

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Measurement of Joint Aperture Using 3-D Laser Profilometer (3차원 레이저 측정기를 이용한 절리 간극의 측정)

  • 이희석;이연규;이희근
    • Economic and Environmental Geology
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    • v.33 no.4
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    • pp.309-320
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    • 2000
  • Aperture is an important parameter for determining the hydraulic characteristics of fractured media. In this study the topography of artificial rock joint surface was measured using 3D laser profilometer to analyze the aperture distribution. The initial aperture distribution was determined when the contact area became one percent of total joint surface. The initial aperture distribution of granite joint, with the mean value of 0.78 mm and the standard deviation of 0.34 mm was much different from that of the marble joint, with the mean value of 0.57 mm and the standard deviation of 0.26 mm. Apertures of both granite and marble showed normal distributions. Aperture distribution with the contact area of 25% was also analyzed. Mean value was decreased to one third compared to the initial aperture, but the standard deviation was decreased slightly. To determine the spatial correlation of the aperture distribution variogram analysis was carried out on the initial aperture data. Most experimental variograms were fitted well with exponential model. It is expected that the measured aperture characteristics can be used for stochastic analysis of fluid flow through rock joints.

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Statistical Analysis for Fatigue Lifetime of Ceramics (세라믹스의 피로수명에 대한 통계적 분석)

  • 박성은;김성욱;이홍림
    • Journal of the Korean Ceramic Society
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    • v.34 no.9
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    • pp.927-934
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    • 1997
  • Static and cyclic fatigue tests were carried out for alumina specimen to study the statistical analyses (normal, lognormal and Weibull distribution) of fatigue lifetime data and nominal initial crack length data. Fatigue lifetime data followed Weibull distribution better than normal or lognormal distribution, for the shape parameter of the notched specimen was larger than that of the unnotched specimen. The nominal initial crack length data obtained from fatigue lifetime followed the lognormal and Weibull distribution better than normal distribution, for the coefficient of variation of the unnotched specimen was larger than that of the notched specimen, and shape parameter of unnotched specimen was smaller than that of the notched specimen.

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The Initial Magnetic Field Decay of the Superconducting Magnet in the Persistent Current Mode (초전도자석의 영구전류모드 운전시 초기자장감쇠)

  • 배준환;심기덕;권영길
    • Progress in Superconductivity and Cryogenics
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    • v.2 no.1
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    • pp.31-34
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    • 2000
  • this paper deals with the initial magnetic field decay for a large scale superconducting magnet e.g. NMR/MRI magnet. The high resolution image can not be obained during the periods of the initial field decay. It is known that all superconducting materials have the property of diamagnetism. This diamagnetism is usually explained with the concept of screening current. We assumed that the existence of the screening currebt. we assumed that the existence of the screening current makes the current distribution in the superconducting wire non-uniform. And the initial magnetic field decay is caused steady current state in the view of its pattern. The initial magnetic field decay is caused by the change of the current distribution between the energizing state and persistent current mode. in this paper the theoretical analysis for the current distributions has been introduced for each state. The experiments have been carried out to verify transport currents in order to veperiments, it small at the higher transport current.

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Blank Design for Optimized Thickness Distribution for Axi-symmetric Superplastic Blow Forming (축대칭 초소성 블로성형의 두께분포 최적화를 위한 블랭크 설계)

  • 이정민;홍성석;김용환
    • Transactions of Materials Processing
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    • v.8 no.1
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    • pp.92-100
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    • 1999
  • A procedure is proposed for determining the initial thickness distribution in oder to produce a specified final thickness distribution for the axisymmetrical superplastic blow forming processes. Weighted parameter is introduced to improve the simple ad $d_traction method and the initial blank thickness distribution is obtained by optimizing the weighted parameter. This method is applied to superplastic free bulging process with the uniform thickness distribution of final shape to confirm its validity. The optimum initial blank thickness distributions is obtained from arbitrary axisymmetrical superplastic blow forming processes such as dome, cone and cylindrical cup forming with die contact. It is concluded that the ad $d_traction method with weighted parameter is an effective method for an optimum blank thickness distribution design.esign.

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Comparison of parameter estimation methods for normal inverse Gaussian distribution

  • Yoon, Jeongyoen;Kim, Jiyeon;Song, Seongjoo
    • Communications for Statistical Applications and Methods
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    • v.27 no.1
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    • pp.97-108
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    • 2020
  • This paper compares several methods for estimating parameters of normal inverse Gaussian distribution. Ordinary maximum likelihood estimation and the method of moment estimation often do not work properly due to restrictions on parameters. We examine the performance of adjusted estimation methods along with the ordinary maximum likelihood estimation and the method of moment estimation by simulation and real data application. We also see the effect of the initial value in estimation methods. The simulation results show that the ordinary maximum likelihood estimator is significantly affected by the initial value; in addition, the adjusted estimators have smaller root mean square error than ordinary estimators as well as less impact on the initial value. With real datasets, we obtain similar results to what we see in simulation studies. Based on the results of simulation and real data application, we suggest using adjusted maximum likelihood estimates with adjusted method of moment estimates as initial values to estimate the parameters of normal inverse Gaussian distribution.

Probabilistic Distribution of Penetration and Break Fatigue Life of Surface Crack (표면크랙의 관통 및 파단 피로수명의 확률분포)

  • 윤한용
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.18 no.10
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    • pp.2495-2500
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    • 1994
  • A method of prediction for the fatigue life of surface crack, that is, initial cracks grow and penetrate through the thickness, was presented in the previous study of the author. Effects of parameters such as the initial crack length, material factors, etc., for the life were discussed. In this paper, the probabilistic distribution of the life is calculated. Effects of the distribution of parameters for the distribution of life were also discussed.

Initial Growth Mode and Nanostructure of Bulk Heterojunction Layers in Planar Type Metal Pthanlocyanine Molecules

  • Kim, Hyo-Jung;Kima, Ji-Whan;Lee, Hyun-Hwi;Lee, Byeon-Du;Kim, Jang-Joo
    • Proceedings of the Korean Vacuum Society Conference
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    • 2012.08a
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    • pp.162-162
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    • 2012
  • ZnPc and CuPc molecules stacked similar way in the film, but showed different growth modes in thermal evaporation. The distribution of CuPc crystals did not change by the film thickness, whereas the distribution of ZnPc became random as the increase of the film thickness. The disc type nanograins of CuPc were quite regularly distributed at the initial growth regime and the regular distribution of nanograins was kept during the film growth. On the other hand, ZnPc consisted in ellipsoid shaped nanograins and the distribution of nanograins was not regular in the initial growth regime. The irregular distribution of nanograins changed to the regular mode at the later growth regime by showing structure factor in GISAXS measurement. The different initial nanograin distribution in ZnPc and CuPc was related to the different nanostructure in the mixed layer with C60 to form the bulk heterojunction.

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Prenatal effect of pyrantel pamoate on several hematological parameter of offspring in mice

  • Abdulwahab.A.Noorwall;Ghazi M. Al-Hachim;Award -Omar
    • Archives of Pharmacal Research
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    • v.9 no.2
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    • pp.87-91
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    • 1986
  • In attempt to develop a drug delivery system using serum albumin microspheres, bovine serum albumin microspheres containing antitumar agent. Cytarabine, were prepared. The shape, surface characteristics, size distribution, behavior of in vivo distribution, drug release behavior, and degradation of albumin microsphers in animal liver issue homogenate and proteolytic enzyme were investigated. The shape of albumin microspheres was spherical and the surface was smooth and compact. The size distribution of the albumin microspheres was effected by dispertion forces during emulsification and albumin concentration. Distribution of albumin microspheres after imtravenous administration in rabbit was achieved immediately. In vitro, albumin microsphere matrix was so hard that it retained most of cytarabine except initial burst during the first 10 minutes, and the level of drug release during the initial burst was affected by heating temperature, drug/albumin microsphere matrix was so hard that it retained most of cytarabine except initial burst during the first 10 minutes, and the level of drug release during the initial burst was affected by heating temperature, drug/albumin concentration ratio and size distribution. After drug release test, the morphology of albumin microspheres was not changed. Albumin microsphere matrix was degraded by the animal liver issue homogenate and proteolytic enzyme. The degree of degradation was affected by heating temperature.

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Dynamics of Global Distribution after Initial Entry

  • Park, Young-Eun
    • Journal of Distribution Science
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    • v.15 no.12
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    • pp.5-19
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    • 2017
  • Purpose - This study involves the following questions: "Does internalization theory fully explain reality?" and "Which additional factors may add extra value to the theory?" To answer these, this study divides market entry mode into two steps, initial and subsequent and then, focuses on the subsequent distribution step; that is, the post-entry strategy after initial entry. In addition, this study relies on finding strategic orientations that affect the decision of post-entry into foreign markets. Research design, data, and methodology - To investigate this, this study examines 252 cases of Korean online games for each foreign market and the distribution mode at the product-team level. Results - The result shows that companies use different distribution strategies as a post-entry mode, like licensing, or joint distribution rather than exclusive distribution, through subsidiaries even if they already have wholly owned local subsidiaries which have enough experience and resources to select the entry modes among various types and then provide full commitment and control. Additionally, it finds that strategic orientation affects post-entry strategies differently. Conclusions - Therefore, this study is noteworthy and significant, as it practically extends the existing theories such as an internalization and distribution for decision making regarding the overseas expansion of entertainment businesses.