• Title/Summary/Keyword: divergence time

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Reliability-Based Design of Vertical Drain Method Considering Uncertainties in Geotechnical Property (연약지반의 불확실성을 고려한 연직배수공법의 신뢰성 설계)

  • Kim, Byung-Il;Sah, Sang-Ho;Kim, Bang-Sig;Kim, Soo-Sam
    • Proceedings of the Korean Geotechical Society Conference
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    • 2006.03a
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    • pp.1148-1154
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    • 2006
  • Composite discharge capacity tests and smear effect tests are carried out to estimate the parameters for the reliability-based design of vertical drain method. Also the probabilistic and deterministic solutions of radial consolidation theory are presented. It compared to the result of reliability-based design and that of deterministic design using the tested and estimated parameters. The results indicated that the drain spacing is larger the deterministic method than the probabilistic method because the former is not considered the uncertainties in the properties of soil. The divergence of methods is dependent on the probability of achieving target degree of consolidation by a given time and the coefficient of variation(COV) of the coefficient of horizontal consolidation$(c_h)$.

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Spatio-temporal Distributions of the Wind Stress and the Thermocline in the East Sea of Korea

  • NA Jung-Yul;HAN Sang-Kyu
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.21 no.6
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    • pp.341-350
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    • 1988
  • The wind stress distribution over the East Sea of Korea was obtained from the shipboard observations of the Fisheries Research and Development Agency along the serial observation lines. These monthly and annual mean wind stress distributions were put into the simplified interface model which describes the latitudinal variations of the upper-layer thickness as function of the curl of the wind stress. The observed variations of the surface, zonally averaged winds indeed caused the upper-layer flow convergent and divergent at the latitudes that produced a tone of thick upper-layer or a deep permanent thermocline and the shallower depth with divergence. Thus, the wind field contributes positively to maintain the almost time-independent distribution of the interface of 'saddle like' feature in north-south direction over the study area.

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Dynamic Stability and Vibration of a Drum Brake Shoe under a Distributed Frictional Force (분포 마찰력을 받는 드럼 브레이크-슈의 동적안정성과 진동)

  • Ryu, Bong-Jo;Ryu, Si-Ung;Yoshihiko Sugiyama;Oh, Boo-Jin
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2001.05a
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    • pp.207-212
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    • 2001
  • In this paper, dynamic stability and vibration characteristics of a flexible shoe in drum brake systems are investigated. The frictional force between the drum and the shoe is assumed as a distributed frictional force, while the shoe is modeled as an elastic beam supported by two translational springs at both ends and elastic foundations. Governing equations of motion are derived by energy expressions, and numerical results are calculated by finite element method. Through the numerical simulation, critical distributed frictional forces are calculated by changing the stiffness of two translational springs and elastic foundation parameters. It is also shown that the beam loses its stability by flutter and divergence depending on the stiffness of elastic supports and elastic foundation parameters. Finally, the time responses of the beam corresponding to their instability types are demonstrated.

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A Computational Study on Vortex Shedding around a Hydrofoil (날개 주위의 비정상 박리 현상에 관한 연구)

  • Wu-Joan Kim
    • Journal of the Society of Naval Architects of Korea
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    • v.32 no.3
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    • pp.51-61
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    • 1995
  • A numerical method was developed to solve the Navies-Stokes equations for unsteady laminar flow around a hydrofoil. The present method used the finite-difference scheme in the collocated grid system and the pressure-Poisson method was employed to obtain divergence-free velocity field each time step. The numerical method was applied at first to laminar flow around a circular cylinder to confirm capability of the code. In the next, calculations were carried out for a hydrofoil in an unbounded fluid at the Reynolds number of $10^4$ in order to investigate unsteady phenomena with vortex shedding. The calculate results showed reasonable features about laminar vortex shedding around a streamlined body.

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Duality of Photonic Crystal Radiative Structures and Antenna Arrays

  • Bozorgi, Mahdieh;Granpayeh, Nosrat
    • Journal of the Optical Society of Korea
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    • v.14 no.4
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    • pp.438-443
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    • 2010
  • In this paper, behaviors of photonic crystal (PC) radiative structures and antenna arrays have been compared for two types of uniform and binomial excitations. Appropriate duality has been shown between them. These results can be generalized to other types of excitation and arrangement of photonic crystal radiative arrays such as linear, planar and circular arrays of three dimensional (3D) photonic crystal termination resonators. Using these results in designing photonic circuits has some advantages for shaping a particular radiative beam at the photonic crystal exit, for instance reducing the divergence angle of the main lobe in order to enhance the directivity, for better coupling, or for splitting the emitted beam, for dividing the output beam to the next devices in photonic integrated circuits (PIC). For analysis and simulation of the photonic crystal structures, the finite difference time domain (FDTD) method has been employed.

Analysis of the Open Source Software Sector in China

  • Wu Qiong;Klincewicz Krzysztof;Miyazaki Kmiko
    • Journal of Technology Innovation
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    • v.14 no.2
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    • pp.117-141
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    • 2006
  • The paper describes the status and context of the Chinese Open Source Software (OSS) industry and ecosystem based on the analysis of the components of the China OSS Promotion Union. The analysis involves comparisons of several main Chinese developers of Linux operating system and makers of open source counterpart of the popular Microsoft Office package as well as several main Chinese OSS communities. Comparisons concern the technological and business aspect. The findings reveal peculiarities of the divergence of innovative activities of Chinese companies, as well as indicate that the strong government support may at the same time limit the technology selection under rigid competition, especially as foreign open source companies are found to be more focused on hobbyist developers and are able to maintain larger independent communities. Implications of the paper include the need to coordinate global development efforts and adjust science & technology policies in order to stimulate both the development and the diffusion of open source among Chinese companies and individual hobbyists.

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The Genetic Diversity of Seven Pig Breeds in China, Estimated by Means of Microsatellites

  • Li, X.;Li, K.;Fan, B.;Gong, Y.;Zhao, S.;Peng, Z.;Liu, B.
    • Asian-Australasian Journal of Animal Sciences
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    • v.13 no.9
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    • pp.1193-1195
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    • 2000
  • The polymorphisms of six microsatellites were investigated in four indigenous pig breeds (Erhualian, Tongcheng, Qingping and Wannanhua) and three introduced breeds (Large White, Landrace and Duroc) in China, and the genetic variations within and among populations were analyzed. The results showed that genetic diversity of Chinese indigenous pig breeds is higher than that of the introduced pig breeds. The clustering of seven breeds is consistent with their geographical distribution approximately. Estimated time of breed divergence ranged from 653 to 1856 years.

An Analysis of Capacitance in Multi-electrode System by Surface-Contacted Elements (표면접촉요소에 의한 다중 전극계의 정전용량 해석)

  • Park, Pil-Yong;Choi, Seung-Kil;Shim, Jae-Hak;Kang, Hyung-Boo
    • Proceedings of the KIEE Conference
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    • 1999.07e
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    • pp.2287-2289
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    • 1999
  • In this paper, a new method for calculating capacitance in multi-electrode system with arbitrarily shape is presented. This new approach based on divergence theorem and Gauss's law is achieved by Surface-Contacted Element(SCE) for Gaussian surface. To evaluate capacitance in multi-electrode system, two dimensional finite element method using only the elements which is contacted one nod (PE: Point-Element) or two nod (FE: Face-Element) with surface is employed. The proposed SCE method has short computing time to calculate capacitance which is because it uses only SCE elements and needs one calculation loop while exiting FEM method in servral loops. This method is verified by application in calculating capacitance using potential detection device model which is composed with anode, cathode, and floating electrode.

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THE WORLD ENERGY OUTLOOK : CONVERGENCE AND DIVERGENCE

  • Korea Energy Forum
    • 에너지협의회보
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    • s.76
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    • pp.61-64
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    • 2006
  • Ladies and gentlemen, dear friends and colleagues, it is an honour and a pleasure for me to introduce this event dedicated to the world energy outlook. For a Group like EDF, decisions taken today will have a very long range impact, well into the century (2060-2100). Thinking about the future is therefore a truly useful exercise in the decision-making process. We are at a crossroads. It has been somewhat perplexing to see how widely future scenarios have tended to diverge. So, which path should be taken if all seem equally viable? Thankfully, it seems to me that we are in fact moving towards greater convergence on core issues. I ’m going to attempt to draw out the main points as to why this may be the case. I will first discuss the various scenarios, then the time, technological and political dimensions of the energy outlook.

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Robust CUSUM test for time series of counts and its application to analyzing the polio incidence data

  • Kang, Jiwon
    • Journal of the Korean Data and Information Science Society
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    • v.26 no.6
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    • pp.1565-1572
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    • 2015
  • In this paper, we analyze the polio incidence data based on the Poisson autoregressive models, focusing particularly on change-point detection. Since the data include some strongly deviating observations, we employ the robust cumulative sum (CUSUM) test proposed by Kang and Song (2015) to perform the test for parameter change. Contrary to the result of Kang and Lee (2014), our data analysis indicates that there is no significant change in the case of the CUSUM test with strong robustness and the same result is obtained after ridding the polio data of outliers. We additionally consider the comparison of the forecasting performance. All the results demonstrate that the robust CUSUM test performs adequately in the presence of seemingly outliers.