Advanced programming methods and data structures for computational modelling using edge‐based finite volume methods     

I. Masters  I. Rees  R.W. Lewis 《国际地质力学数值与分析法杂志》2004,28(15):1521-1532

The generation of a numerical model must consider the separate issues of the governing equations, the numerical representation of those equations, the data structure that describes the model, the choice of programming language and finally the implementation and code management issues. These issues are considered as a whole in this paper and as a consequence, 10 golden rules for numerical modelling are proposed. By way of application, a saturated–unsaturated flow problem is modelled using the Richards equation and an innovative edge‐based finite volume method. The implementation uses a novel data structure. This is shown to have over 91% code re‐use and hence code written in this way is highly flexible and applicable to many different problems. By way of example, a compacted core earth filled dam problem has been solved. Finally, we conclude that this advanced programming method can significantly reduce code development time. Copyright © 2004 John Wiley & Sons, Ltd.  相似文献   

Afterglow light curves, viewing angle and the jet structure of γ-ray bursts     

Elena Rossi  Davide Lazzati  Martin J. Rees 《Monthly notices of the Royal Astronomical Society》2002,332(4):945-950

Gamma-ray bursts are often modelled as jet-like outflows directed towards the observer; the cone angle of the jet is then commonly inferred from the time at which there is a steepening in the power-law decay of the afterglow. We consider an alternative model in which the jet has a beam pattern where the luminosity per unit solid angle (and perhaps also the initial Lorentz factor) decreases smoothly away from the axis, rather than having a well-defined cone angle within which the flow is uniform. We show that the break in the afterglow light curve then occurs at a time that depends on the viewing angle. Instead of implying a range of intrinsically different jets – some very narrow, and others with a similar power spread over a wider cone – the data on afterglow breaks could be consistent with a standardized jet, viewed from different angles. We discuss the implication of this model for the luminosity function.  相似文献   

Dynamo processes and activity cycles of the active stars AB Doradus, LQ Hydrae and HR 1099     

J.-F. Donati  A. Collier Cameron  M. Semel  G. A. J. Hussain  P. Petit  B. D. Carter  S. C. Marsden  M. Mengel  A. López Ariste  S. V. Jeffers  D. E. Rees 《Monthly notices of the Royal Astronomical Society》2003,345(4):1145-1186

  相似文献   

SOURCES FOR THE STUDY OF MEXICAN URBANISM*     

Peter W. Rees 《The Professional geographer》1974,26(4):399-406

  相似文献   

Using GIS and a digital elevation model to assess the effectiveness of variable grade flow diversion terraces in reducing soil erosion in northwestern New Brunswick,Canada     

Qi Yang  Zhengyong Zhao  Thien Lien Chow  Herb W. Rees  Charles P.‐A. Bourque  Fan‐Rui Meng 《水文研究》2009,23(23):3271-3280

Flow diversion terraces (FDT) are commonly used beneficial management practice (BMP) for soil conservation on sloped terrain susceptible to water erosion. A simple GIS‐based soil erosion model was designed to assess the effectiveness of the FDT system under different climatic, topographic, and soil conditions at a sub‐basin level. The model was used to estimate the soil conservation support practice factor (P‐factor), which inherently considered two major outcomes with its implementation, namely (1) reduced slope length, and (2) sediment deposition in terraced channels. A benchmark site, the agriculture‐dominated watershed in northwestern New Brunswick (NB), was selected to test the performance of the model and estimated P‐factors. The estimated P‐factors ranged from 0·38–1·0 for soil conservation planning objectives and ranged from 0·001 to 0·45 in sediment yield calculations for water‐quality assessment. The model estimated that the average annual sediment yield was 773 kg ha^?1 yr ^?1 compared with a measured value of 641 kg ha^?1 yr^?1. The P‐factors estimated in this study were comparable with predicted values obtained with the revised universal soil loss equation (RUSLE2). The P‐factors from this study have the potential to be directly used as input in hydrological models, such as the soil and water assessment tool (SWAT), or in soil conservation planning where only conventional digital elevation models (DEMs) are available. Copyright © 2009 John Wiley & Sons, Ltd.  相似文献   

Reply to I.C. McDade and E.J. Llewellyn's comments on proposed mechanisms for the excitation of 0(1S) in the Aurora     

M.H. Rees 《Planetary and Space Science》1984,32(9):1199-1200

  相似文献   

Geomagnetism in marine geology: V. Vacquier. Elsevier,Amsterdam, 1972, 185 pp., Dfl. 42.50     

A.I. Rees 《Journal of Geochemical Exploration》1973,2(3):301-302

  相似文献   

Evidence on neutron star structure from pulsars and related objects     

M. J. Rees 《Astrophysics and Space Science》1976,39(1):3-7

Properties of pulsars and binary X-ray sources which seem particularly relevant to theories of neutron star structure and strong magnetic fields are reviewed and discussed.Paper presented at the Symposium on Solid State Astrophysics, held at the University College, Cardiff, Wales, between 9–12 July, 1974.  相似文献   

Paleoclimate, paleomagnetism, and continental drift: AAPG studies in geology, 9. J.K.A. Habicht. The American Association of Petroleum Geologists, tulsa, okla., 1979, 30 pp. with 11 fold-out diagrams, US $ 15.00     

A.I. Rees 《Tectonophysics》1981,74(3-4)

  相似文献   

Excitation of O(¹S) and emission of 5577 Å radiation in aurora     

M.H. Rees 《Planetary and Space Science》1984,32(3):373-378

The results of recent laboratory experiments suggest that the reaction N⁺ + O₂ → NO⁺ + O(¹S) is the principal source of O(¹S) in aurora. A negligible time delay between auroral ionization and O(¹S) production is associated with this indirect process, which is a necessary condition for a viable mechanism. The $\text{5577}\text{A}\text{?}\text{3914}\text{A}\text{?}$ volume emission rate ratio associated with this production source remains constant with altitude. The problems encountered by the currently accepted source of O(¹S), the reaction of N₂(A³Σ) molecules with atomic oxygen are explored, and the contributions of this and other reactions to the auroral green line emission are reevaluated.  相似文献