• Title/Summary/Keyword: Transport functions

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A Study on Prediction of Sediment and Riverbed Variation According to Sediment Transportation Functions (유사량 산정공식에 따른 유사 및 하상변동 예측에 관한 연구)

  • Go, Su Hyeon;Song, In Ryeol;Kim, Chang Seok
    • Journal of Environmental Science International
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    • v.13 no.3
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    • pp.263-277
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    • 2004
  • The purpose of this study is to analyze the characteristics of riverbed variation due to the sediment protection weir located on the estuary of the main stream of Taehwa river using I-D finite difference model, HEC-6 model, and the followings are the results of estimating sediment transport rate, amount of scour or deposition, and accumulated amount of deposit according to before and after of the sediment protection weir removal with various flow rates in the channel. Ackers-White transport function produced the greatest sediment transport rate while Meyer-Peter showed the smallest sediment transport rate at the most down stream area of the watershed through the sediment transport rate analyses for various flow rates according to the existence or nonexistence of the sediment protection weir. Toffaleti's and Colby transport function were closest to the average value, and the difference among the results of the sediment transport functions showed up to 8~9 times. Duboy's transport function produced the greatest riverbed variation while Toffaleti's showed the smallest variation through the riverbed variation analyses according to the existence or nonexistence of the sediment protection weir. Yang's was closest to the average value, and the difference among the results of the riverbed variation analyses ranged from 1.4 times to 11 times. It is thought that a sediment transport function must be selected very carefully with respect to the criteria of sediment yield estimation because the analysis results of the sediment transport rate and riverbed variation according to flow rates showed significant differences among the sediment transport functions, and the differences of sediment transport rate and riverbed variation according to the various sediment transport functions decreased as the flow rate increased.

Equilibrium Molecular Dynamics Simulation Study for Transport Properties of Noble Gases: The Green-Kubo Formula

  • Lee, Song Hi
    • Bulletin of the Korean Chemical Society
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    • v.34 no.10
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    • pp.2931-2936
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    • 2013
  • This paper presents results for the calculation of transport properties of noble gases (He, Ne, Ar, Kr, and Xe) at 273.15 K and 1.00 atm using equilibrium molecular dynamics (EMD) simulations through a Lennard-Jones (LJ) intermolecular potential. We have utilized the revised Green-Kubo formulas for the stress (SAC) and the heat-flux auto-correlation (HFAC) functions to estimate the viscosities (${\eta}$) and thermal conductivities (${\lambda}$) of noble gases. The original Green-Kubo formula was employed for diffusion coefficients (D). The results for transport properties (D, ${\eta}$, and ${\lambda}$) of noble gases at 273.15 and 1.00 atm obtained from our EMD simulations are in a good agreement with the rigorous results of the kinetic theory and the experimental data. The radial distribution functions, mean square displacements, and velocity auto-correlation functions of noble gases are remarkably different from those of liquid argon at 94.4 K and 1.374 $g/cm^3$.

Genome wide identification of Staufen2-bound mRNAs in embryonic rat brains

  • Maher-Laporte, Marjolaine;DesGroseillers, Luc
    • BMB Reports
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    • v.43 no.5
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    • pp.344-348
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    • 2010
  • Messenger ribonucleoprotein particles (mRNPs) are used to transport mRNAs along neuronal dendrites to their site of translation. Staufen2 is an mRNA-binding protein expressed in the cell bodies and cellular processes of different brain cells. It is notably involved in the transport of dendritic mRNAs along microtubules. Its knockdown expression was shown to change spine morphology and impair synaptic functions. However, the identity of Staufen2-bound mRNAs in brain cells is still completely unknown. As a mean to identify these mRNAs, we immunoprecipitated Staufen2-containing mRNPs from embryonic rat brains and used a genome wide approach to identify Staufen2-associated mRNAs. The genome wide approach identified 1780 mRNAs in Staufen2-containing mRNPs that code for proteins involved in cellular processes such as post-translational protein modifications, RNA metabolism, intracellular transport and translation. These results represent an additional and important step in the characterization of Staufen2- mediated neuronal functions in rat brains.

Functional analysis of air transport mission (항공 수송 임무의 기능 분석에 관한 연구)

  • Song, Youn-Seob
    • Journal of the Korean Society for Aviation and Aeronautics
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    • v.16 no.4
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    • pp.41-48
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    • 2008
  • Functional analysis of air transport mission is conducted to establish the performance requirements of the commercial transport designs. The analysis process begins by making a top-down analysis to the aircraft system level mission functions. Correctly interpreting the top-level performance requirements is the first step in designing and building an aircraft system. Each function and sub-function is allocated and examined to the aircraft level and flight operations phase to optimize the system performance and design requirements, such that these lower-level requirements can be traced back to the top-level requirements they are designed to fulfill. Special attention is given to making sure all interfaces, both internal and external, are addressed. The results are also in good resources of functional hazard assessment involved in certification processes.

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Changes in Renal Brush-Border Sodium-Dependent Transport Systems in Gentamicin-Treated Rats

  • Suhl, Soong-Yong;Ahn, Do-Whan;Kim, Kyoung-Ryong;Kim, Jee-Yeun;Park, Yang-Saeng
    • The Korean Journal of Physiology and Pharmacology
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    • v.1 no.4
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    • pp.403-411
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    • 1997
  • To elucidate the mechanism of gentamicin induced renal dysfunction, renal functions and activities of various proximal tubular transport systems were studied in gentamicin-treated rats (Fisher 344). Gentamicin nephrotoxicity was induced by injecting gentamicin sulfate subcutaneously at a dose of 100 $mg/kg{\cdot}day$ for 7 days. The gentamicin injection resulted in a marked polyuria, hyposthenuria, proteinuria, glycosuria, aminoaciduria, phosphaturia, natriuresis, and kaliuresis, characteristics of aminoglycoside nephropathy. Such renal functional changes occurred in the face of reduced GFR, thus tubular transport functions appeared to be impaired. The polyuria and hyposthenuria were partly associated with a mild osmotic diuresis, but mostly attributed to a reduction in free water reabsorption. In renal cortical brush-border membrane vesicles isolated from gentamicin-treated rats, the $Na^+$ gradient dependent transport of glucose, alanine, phosphate and succinate was significantly attenuated with no changes in $Na^+-independent$ transport and the membrane permeability to $Na^+$. These results indicate that gentamicin treatment induces a defect in free water reabsorption in the distal nephron and impairs various $Na^+-cotransport$ systems in the proximal tubular brush-border membranes, leading to polyuria, hyposthenuria, and increased urinary excretion of $Na^+$ and other solutes.

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Molecular Dynamics Simulation Study of Transport Properties of Diatomic Gases

  • Lee, Song Hi;Kim, Jahun
    • Bulletin of the Korean Chemical Society
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    • v.35 no.12
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    • pp.3527-3531
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    • 2014
  • In this paper, we report thermodynamic and transport properties (diffusion coefficient, viscosity, and thermal conductivity) of diatomic gases ($H_2$, $N_2$, $O_2$, and $Cl_2$) at 273.15 K and 1.00 atm by performing molecular dynamics simulations using Lennard-Jones intermolecular potential and modified Green-Kubo formulas. The results of self-diffusion coefficients of diatomic gases obtained from velocity auto-correlation functions by Green-Kubo relation are in good agreement with those obtained from mean square displacements by Einstein relation. While the results for viscosities of diatomic gases obtained from stress auto-correlation functions underestimate the experimental results, those for thermal conductivities obtained from heat flux auto-correlation functions overestimate the experimental data except $H_2$.

A radial point interpolation method for 1D contaminant transport modelling through landfill liners

  • Praveen Kumar, R.;Dodagoudar, G.R.
    • Geomechanics and Engineering
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    • v.2 no.2
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    • pp.141-156
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    • 2010
  • In the framework of meshfree methods, a new methodology is developed based on radial point interpolation method (RPIM). This methodology is applied to a one-dimensional contaminant transport modelling in the saturated porous media. The one-dimensional form of advection-dispersion equation involving reactive contaminant is considered in the analysis. The Galerkin weak form of the governing equation is formulated using 1D meshfree shape functions constructed using thin plate spline radial basis functions. MATLAB code is developed to obtain the numerical solution. Numerical examples representing various phenomena, which occur during migration of contaminants, are presented to illustrate the applicability of the proposed method and the results are compared with those obtained from the analytical and finite element solutions. The proposed RPIM has generated results with no oscillations and they are insensitive to Peclet constraints. In order to test the practical applicability and performance of the RPIM, three case studies of contaminant transport through the landfill liners are presented. A good agreement is obtained between the results of the RPIM and the field investigation data.

Protocol-independent Information Modeling and Web Services Implementation for Resource Management in NGN Transport Stratum (NGN 전송 층의 자원 관리를 위한 프로토콜 중립적인 정보 모델링과 웹 서비스 구현)

  • Yim, Young-Eun;Kwon, Tae-Hyun;Kim, Choon-Hee;Han, Tae-Man;Jeong, You-Hyeon;Cha, Young-Wook
    • The KIPS Transactions:PartC
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    • v.14C no.5
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    • pp.453-462
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    • 2007
  • NGN is a packet-based converged network to support session and non-session based services in QoS-enabled broadband transport technologies. Resource and admission control functions(RACF) of NGN have been considering COPS and SNMP as resource management protocols to collect network topology and resource status information of transport network. This paper defines requirements of resource management in NGN transport network, and proposes protocol independent information model to keep consistency of data models of each resource management protocol. Based on this information model described with UML class diagram, we designed and implemented NGN resource management system on Web Services.

Simulation Methods for Prediction of Membrane Protein Structure

  • Son, Hyeon-S.
    • Proceedings of the Korean Biophysical Society Conference
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    • 1998.06a
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    • pp.10-10
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    • 1998
  • IMPs are important to cells in functions such as transport, energy transduction and signalling. Three dimensional molecular structures of such proteins at atomic level are needed to understand such processes. Prediction of such structures (and functions) is necessary especially because there are only a small number of membrane protein structures determined in atomic resolution.(omitted)

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Design of enhanced communications transport service for multimedia applications (멀티미디어 응용을 위한 향상된 트랜스포트 서비스 설계)

  • 강신각;김대영
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.22 no.10
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    • pp.2150-2164
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    • 1997
  • Two distinct features required in transport service and protocol to meet new multimedia applications requirements are multicast transmission capability and enhanced QoS facility. In this paper, we presents major functions and facilities of enhanced communications transport service definition supporting these requirements. At first, major fundamental issues, that should be handled to design multi-peer communcation service and protocol, are resoved and applied to design service definition. Secondly, we proposed several new functions for enhanced transport service such as heterogeneous TC establishment, invitation capability, TC-ownership transfer, restriction of transmit concurrency. The detils of proposed enhanced transport service are TC creation, TC invitation, TC join, multicase data transfer, pause of data transfer, resulme of data transfer, report of specific status, TC leave, TC termination, TC-ownership transfer, Token transfer services. The proposed transport service was submitted and accepted as a draft text for committee draft of international standard by the international standradization body such as JTC1/SC6 and ITU-T SG 7.

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