Response of Simulated Upflow from Shallow Water Tables to Variations in Model Parameter Values

Author(s):  
Peter J. Thorburn ◽  
Wayne S. Meyer
Robotica ◽  
2005 ◽  
Vol 23 (1) ◽  
pp. 21-33 ◽  
Author(s):  
Katja D. Mombaur ◽  
Richard W. Longman ◽  
Hans Georg Bock ◽  
Johannes P. Schlöder

We present simulated monopedal and bipedal robots that are capable of open-loop stable periodic running motions without any feedback even though they have no statically stable standing positions. Running as opposed to walking involves flight phases which makes stability a particularly difficult issue. The concept of open-loop stability implies that the actuators receive purely periodic torque or force inputs that are never altered by any feedback in order to prevent the robot from falling. The design of these robots and the choice of model parameter values leading to stable motions is a difficult task that has been accomplished using newly developed stability optimization methods.


2001 ◽  
Vol 55 (4) ◽  
pp. 38-43 ◽  
Author(s):  
Khaled M. Bali ◽  
Mark E. Grismer ◽  
Richard L. Snyder

2013 ◽  
Vol 49 (10) ◽  
pp. 6700-6715 ◽  
Author(s):  
José-Luis Guerrero ◽  
Ida K. Westerberg ◽  
Sven Halldin ◽  
Lars-Christer Lundin ◽  
Chong-Yu Xu

1963 ◽  
Vol 43 (1) ◽  
pp. 135-140 ◽  
Author(s):  
J. C. van Schaik ◽  
R. A. Milne

Considerable salt accumulation occurred in a grass-covered soil in southern Alberta where the saline groundwater was maintained at a depth of 3 feet. The SAR values of the saturation extract increased significantly under grass, and indications are that this increase was mainly due to precipitation of calcium. A fallow soil did not show a significant salt accumulation above the water table.It is suggested that a leaching program is necessary to maintain low salinity where shallow water tables are present and shallow tile drains are used.


2011 ◽  
Vol 24 (5) ◽  
pp. 1480-1498 ◽  
Author(s):  
Andrew H. MacDougall ◽  
Gwenn E. Flowers

Abstract Modeling melt from glaciers is crucial to assessing regional hydrology and eustatic sea level rise. The transferability of such models in space and time has been widely assumed but rarely tested. To investigate melt model transferability, a distributed energy-balance melt model (DEBM) is applied to two small glaciers of opposing aspects that are 10 km apart in the Donjek Range of the St. Elias Mountains, Yukon Territory, Canada. An analysis is conducted in four stages to assess the transferability of the DEBM in space and time: 1) locally derived model parameter values and meteorological forcing variables are used to assess model skill; 2) model parameter values are transferred between glacier sites and between years of study; 3) measured meteorological forcing variables are transferred between glaciers using locally derived parameter values; 4) both model parameter values and measured meteorological forcing variables are transferred from one glacier site to the other, treating the second glacier site as an extension of the first. The model parameters are transferable in time to within a <10% uncertainty in the calculated surface ablation over most or all of a melt season. Transferring model parameters or meteorological forcing variables in space creates large errors in modeled ablation. If select quantities (ice albedo, initial snow depth, and summer snowfall) are retained at their locally measured values, model transferability can be improved to achieve ≤15% uncertainty in the calculated surface ablation.


2000 ◽  
Vol 126 (4) ◽  
pp. 223-233 ◽  
Author(s):  
R. Ali ◽  
R. L. Elliott ◽  
J. E. Ayars ◽  
E. W. Stevens

Total hip metal arthroplasty (THA) model-parameters for a group of commonly used ones is optimized and numerically studied. Based on previous ceramic THA optimization software contributions, an improved multiobjective programming method/algorithm is implemented in wear modeling for THA. This computational nonlinear multifunctional optimization is performed with a number of THA metals with different hardnesses and erosion in vitro experimental rates. The new software was created/designed with two types of Sytems, Matlab and GNU Octave. Numerical results show be improved/acceptable for in vitro simulations. These findings are verified with 2D Graphical Optimization and 3D Interior Optimization methods, giving low residual-norms. The solutions for the model match mostly the literature in vitro standards for experimental simulations. Numerical figures for multifunctional optimization give acceptable model-parameter values with low residual-norms. Useful mathematical consequences/calculations are obtained for wear predictions, model advancements and simulation methodology. The wear magnitude for in vitro determinations with these model parameter data constitutes the advance of the method. In consequence, the erosion prediction for laboratory experimental testing in THA add up to the literature an efficacious usage-improvement. Results, additionally, are extrapolated to efficient Medical Physics applications and metal-THA Bioengineering designs.


2021 ◽  
Vol 2 ◽  
Author(s):  
Esther M. Sundermann ◽  
Maarten Nauta ◽  
Arno Swart

Dose-response models are an important part of quantitative microbiological risk assessments. In this paper, we present a transparent and ready-to-use version of a published dose-response model that estimates the probability of infection and illness after the consumption of a meal that is contaminated with the pathogen Campylobacter jejuni. To this end, model and metadata are implemented in the fskx-standard. The model parameter values are based on data from a set of different studies on the infectivity and pathogenicity of Campylobacter jejuni. Both, challenge studies and outbreaks are considered, users can decide which of these is most suitable for their purpose. We present examples of results for typical ingested doses and demonstrate the utility of our ready-to-use model re-implementation by supplying an executable model embedded in this manuscript.


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