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A fortran program to produce minimum relative entropy distributions

COMPUTERS & GEOSCIENCES 2004年第1期30卷 131-138页

作者： Woodbury, AD Univ Manitoba Dept Civil & Geol Engn Winnipeg MB R3T 3V5 Canada

Relative entropy minimization is a general approach of inferring a probability density function (pdf) from constraints which do not uniquely determine that density. In this paper, a general purpose computer program written in fortran is provided that produces a univariate pdf from a series of constraints and a prior probability. Some guidelines for the selection of the prior are presented. The fortran code is based on an algorithm that utilize, a Newton-Raphson approach. In addition, we use Gauss-Legendre quadrature for the determination of the integrals, Gauss elimination for matrix solution and a line search for the most optimal Newton step. We present examples of relative entropy minimization involving functions that are geometric moments of a variable x. With a uniform prior p(x), classic solutions of statistics are obtained. We also varied the nature of the prior for illustrative purposes. For the case where the constraints resemble powers of x and logarithmic transformations, minimum relative entropy produces the Gamma distribution. (C) 2003 Elsevier Ltd. All rights reserved.

关键词： relative entropy probabilistic inversion fortran code

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Cython: The Best of Both Worlds

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COMPUTING IN SCIENCE & ENGINEERING 2011年第2期13卷 31-39页

作者： Behnel, Stefan Bradshaw, Robert Citro, Craig Dalcin, Lisandro Seljebotn, Dag Sverre Smith, Kurt Senacor Technol AG Nurnberg Germany Google Mountain View CA USA Natl Council Sci & Technol Res Buenos Aires DF Argentina Univ Oslo Inst Theoret Astrophys N-0316 Oslo Norway Univ Wisconsin Madison Dept Phys Madison WI USA

Cython is a Python language extension that allows explicit type declarations and is compiled directly to C. As such, it addresses Python's large overhead for numerical loops and the difficulty of efficiently using... 详细信息

关键词： C language Cython Cython language fortran code Python Python language extension numerical analysis numerical loops numerics programming language scientific computing

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FALL3D: A computational model for transport and deposition of volcanic ash

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COMPUTERS & GEOSCIENCES 2009年第6期35卷 1334-1342页

作者： Folch, A. Costa, A. Macedonio, G. Ist Nazl Geofis & Vulcanol Osservatorio Vesuviano Naples Italy

FALL3D is a 3-D time-dependent Eulerian model for the transport and deposition of volcanic ashes and lapilli. The model solves the advection-diffusion-sedimentation (ADS) equation on a structured terrain-following grid using a second-order finite differences (FD) explicit scheme. Different parameterizations for the eddy diffusivity tensor and for the particle terminal settling velocities can be used. The code, written in fortran 90, is available in both serial and parallel versions for Windows and Unix/Linux/Mac X operating systems (OS). A series of pre- and post-process utility programs and OS-dependent scripts to launch them are also included in the FALL3D distribution package. Although the model has been designed to forecast volcanic ash concentration in the atmosphere and ash loading at ground, it can also be used to model the transport of any kind of airborne solid particles. The model inputs are meteorological data, topography, grain-size distribution, shape and density of particles, and mass rate of particle injected into the atmosphere. Optionally, FALL3D can be coupled with the output of the meteorological processor CALMET, a diagnostic model which generates 3-D time-dependent zero-divergence wind fields from mesoscale forecasts incorporating local terrain effects. The FALL3D model can be a too[ for short-term ash deposition forecasting and for volcanic fallout hazard assessment. As an example, an application to the 22 July 1998 Etna eruption is also presented. (C) 2008 Elsevier Ltd. All rights reserved.

关键词： Volcanic ash Fallout Computational model fortran code

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A T-matrix method and computer code for randomly oriented, axially symmetric coated scatterers

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JOURNAL OF QUANTITATIVE SPECTROSCOPY & RADIATIVE TRANSFER 2005年第3期92卷 373-381页

作者： Quirantes, A Univ Granada Dept Fis Aplicada E-18071 Granada Spain

A computer code is described for the calculation of light-scattering properties of randomly oriented, axially symmetric coated particles, in the framework of the T-matrix theory. The underlying mathematical background is outlined briefly and convergence procedures are discussed. After outlining the input-output interaction between user and code, benchmark results are presented for two distinct shapes: coated, centered spheroids and offset coated spheres. (C) 2004 Elsevier Ltd. All rights reserved.

关键词： T-matrix nonspherical scatterers coated particles fortran code

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A numerical study on characteristics of heat transfer in hydrogen filling storage vessel by charging conditions

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INTERNATIONAL JOURNAL OF HYDROGEN ENERGY 2022年第61期47卷 25679-25695页

作者： Oh, Seung Jun Yoon, Jeong Hwan Jeon, Kyung Sook Choi, JeongJu Dong A Univ Tech Ctr High Performance Valves 37 Nakdong Daero 550 Beon Gil Busan South Korea Dong A Univ Dept Mech Engn 37 Nakdong Daero 550 Beon Gil Busan South Korea

Recently, studies on alternative energy and new energy has been actively conducted due to environmental pollution issues. In particular, hydrogen, which is new energy, has no greenhouse gas emissions and can be produced from compounds such as water and organic matter and has no regional bias. Hydrogen electric vehicles have advantages such as high energy density and low charging time compared to electric vehicles based on battery. Many studies are being conducted on storage vessels because hydrogen is charged in storage vessel. Therefore, in this study, first, we compared experimental data with numerical analysis data to verify the numerical method and identify the relationship between Nu and Re numbers. As a result, the relationship of Nu = 0:015Re(0.9) was derived. Second, we applied the relationship of dimensionless number to the fortran code to verify the results of the coded program by comparing them with those of the commercial program. Third, based on the developed fortran code, the variables were set such as APRR(Average pressure ramp rate), inflow temperature, initial pressure and ambient air temperature. As a result of the analysis, the final charging temperature increases as the APRR rises and the final charging temperature decreases as the inflow temperature decreases. Furthermore, the increase in initial pressure has a small effect on the final temperature reduction and the effect of ambient air temperature on the final charge temperature was minimal. It is considered that the final charging temperature of the hydrogen charging storage vessel can be effectively adjusted according to the APRR and inflow temperature setting through the main effect analysis. (C) 2022 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.

关键词： Heat transfer Hydrogen Hydrogen storage vessel Numerical analysis fortran code

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FeynHiggs:: a program for the calculation of the masses of the neutral CP-even Higgs bosons in the MSSM

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COMPUTER PHYSICS COMMUNICATIONS 2000年第1期124卷 76-89页

作者： Heinemeyer, S Hollik, W Weiglein, G DESY Theorie D-22603 Hamburg Germany Univ Karlsruhe Inst Theoret Phys D-76128 Karlsruhe Germany CERN Div Theoret Phys CH-1211 Geneva Switzerland

FeynHiggs is a fortran code for the calculation of the masses of the neutral CP-even Higgs bosons in the MSSM up to two-loop order. It is based on the complete diagrammatic on-shell result at the one-loop level, the leading diagrammatic two-loop QCD contributions and further improvements taking into account leading electroweak two-loop and lending higher-order QCD corrections. The Higgs-boson masses are calculated as functions of the MSSM parameters for general mixing in the scaler top sector and arbitrary choices of the parameters in the Higgs sector of the model. (C) 2000 Elsevier Science B.V. All rights reserved.

关键词： Higgs-boson masses MSSM fortran code higher order corrections Feynman-diagrammatic calculation

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SEDTRANS92 - A SEDIMENT TRANSPORT MODEL FOR CONTINENTAL SHELVES

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COMPUTERS & GEOSCIENCES 1995年第4期21卷 533-554页

作者： LI, MZ AMOS, CL Geological Survey of Canada Bedford Institute of Oceanography P.O. Box 1006 Dartmouth N.S. B2Y 4A2 Canada

The Atlantic Geoscience Centre sediment transport model (SEDTRANSB2) is an ANSI standard fortran-77 numerical model that has been under development for the last 9 years. For given input data of wave, current, and seabed conditions, SEDTRANS92 applies combined wave-current bottom boundary layer theories to derive enhanced bottom shear stresses. Then it calculates sediment transport rates for a given grain size using one of seven algorithms: Engelund and Hansen, total load equation;Einstein-Brown, bedload equation;Bagnold, total load equation;Yalin, bedload equation;Ackers and White, total load equation;Smith, suspended load method;and the cohesive sediment transport algorithm of Amos and Greenberg. This model adopts new advances of bottom boundary layer theory and recently available field measurements of sediment transport rates on the Scotian Shelf. The model gives reasonable predictions compared to the field measurements.

关键词： COMBINED WAVE-CURRENT FLOWS SHELF SEDIMENT TRANSPORT fortran code COMPUTER SIMULATION PREDICTIONS AND FIELD DATA

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Multicanonical simulations step by step

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COMPUTER PHYSICS COMMUNICATIONS 2003年第3期153卷 397-406页

作者： Berg, BA Florida State Univ Dept Phys Tallahassee FL 32306 USA

The purpose of this article is to provide a starter kit for multicanonical simulations in statistical physics. fortran code for the q-state Potts model in d = 2, 3,... dimensions can be downloaded from the Web and this paper describes simulation results, which are in all details reproducible by running prepared programs. To allow for comparison with exact results, the internal energy, the specific heat, the free energy and the entropy are calculated for the d = 2 Ising (q = 2) and the q = 10 Potts model. Analysis programs, relying on an all-log jackknife technique, which is suitable for handling sums of very large numbers, are introduced to calculate our final estimators. (C) 2003 Elsevier B.V. All rights reserved.

关键词： multicanonical algorithm fortran code all-log jackknife technique internal energy free energy entropy

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TWODEE-2: A shallow layer model for dense gas dispersion on complex topography

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COMPUTERS & GEOSCIENCES 2009年第3期35卷 667-674页

作者： Folch, A. Costa, A. Hankin, R. K. S. Ist Nazl Geofis & Vulcanol Sez Napoli I-80124 Naples Italy Natl Oceanog Ctr Southampton SO14 3ZH Hants England

TWODEE-2 is a fortran 90 code based on previous code (TWODEE). It is designed to solve the shallow water equations for fluid depth, depth-averaged horizontal velocities and depth-averaged fluid density. The shallow layer approach used by TWODEE-2 is a compromise between the complexity of CFD models and the simpler integral models. It can be used for forecasting gas dispersion near the ground and/or for hazard assessment over complex terrains. The inputs to the model are topography, terrain toughness, wind measurements from meteorological stations and gas flow rate from the ground sources. Optionally the model can be coupled with the output of a meteorological processor which generates a zero-divergence wind field incorporating terrain effects. Model outputs are gas concentration, depth-averaged velocity, averaged cloud thickness and dose. The model can be a useful tool for gas hazard assessment by evaluating where and when lethal concentrations for humans and animals can be reached. (C) 2008 Elsevier Ltd. All rights reserved.

关键词： Dense gas transport fortran code Gas hazard Computational model

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A computer model for volcanic ash fallout and assessment of subsequent hazard

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COMPUTERS & GEOSCIENCES 2005年第7期31卷 837-845页

作者： Macedonio, G Costa, A Longo, A Osserv Vesuviano INGV I-80124 Naples Italy Univ Pisa Dipartimento Sci Terra I-56100 Pisa Italy INGV Sez Pisa Pisa Italy

HAZMAP is a fortran code for the solution of the equations of diffusion, transport and sedimentation of small particles, in order to model the dispersion of ash generated by a convective column. The model was developed simplifying the advection-diffusion-sedimentation equation for volcanic ash transport in the atmosphere from three to two dimensions and using a semi-analytical computational method to greatly reduce the required computer time and memory. HAZMAP can be used either to simulate the mass distribution of the deposit if a wind profile is given ("deposit mode"), or to define the probability of a given accumulation of mass on the ground if a statistical set of wind profiles is provided ("probability mode"). The model needs the definition of the physical system (spatial distribution of the point sources, total erupted mass, settling velocity distribution, wind velocity profile, atmospheric turbulent diffusion coefficients), and of a computational grid. The output values of mass accumulation on the ground or the probability of mass accumulation are computed on a regular grid, suitable for further analysis. (C) 2005 Elsevier Ltd. All rights reserved.

关键词： ash fall fortran code volcanology volcanic hazard semi-analytical model

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