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Climate change impacts on streamflow,water quality,and best management practices for the Shell and Logan Creek Watersheds in Nebraska,USA

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International Journal of Agricultural and Biological Engineering 2012年第1期5卷 13-34页

作者： Michael W.Van Liew Song Feng Tapan B.Pathak Department of Biological Systems Engineering University of Nebraska-LincolnNEUSA School of Natural Resources University of Nebraska-LincolnNEUSA

Improvements in the management of water,sediment,and nutrients under future climatic conditions are needed to ensure increased crop and livestock production to meet greater global needs and the future availability of water for competing demands and protection against adverse water quality *** study determined the impacts of future climate change scenarios on streamflow,water quality,and best management practices(BMPs)for two watersheds in Nebraska,*** Soil and Water Assessment Tool(SWAT)was employed to simulate streamflow,sediment,total nitrogen(N)and total phosphorus(P)from the Shell Creek Watershed near Columbus,Nebraska and the Logan Creek Watershed near Sioux City,*** streamflow and water quality records for the two watersheds were used to calibrate model parameters that govern streamflow,sediment,and nutrient responses in *** each watershed,precipitation,air temperature,and CO2 concentrations were input to SWAT for four climatic conditions:a baseline condition for the 1980 to 2000 period and the SRES A2,A1B,and B1 climate scenarios for a future period from 2040 to *** from this study suggest that under the three future climate change scenarios,sediment losses are expected to be about 1.2 to 1.5 times greater than the baseline condition for Shell Creek and 2 to 2.5 times greater for Logan Creek;total N losses are expected to be about 1.2 to 1.4 times greater for Shell Creek and 1.7 to 1.9 times greater for Logan *** to the baseline,total P losses under the future climate scenarios are projected to be about the same for Shell Creek and 1.5 to 1.7 times greater for Logan *** from this study also suggest that future projected increases in both precipitation and CO2 concentration account for net increases in streamflow,but in different ways on each watershed.

关键词： hydrology water quality model calibration climate change SWAT

A primer on model selection using the Akaike Information Criterion

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Infectious Disease modelling 2020年第1期5卷 111-128页

作者： Stéphanie Portet Department of Mathematics University of ManitobaWinnipegManitobaR3T 2N2Canada

A powerful investigative tool in biology is to consider not a single mathematical model but a collection of models designed to explore different working hypotheses and select the best model in that *** these lecture notes,the usual workflow of the use of mathematical models to investigate a biological problem is described and the use of a collection of model is *** depend on parameters that must be estimated using observations;and when a collection of models is considered,the best model has then to be identified based on available ***,model calibration and selection,which are intrinsically linked,are essential steps of the ***,some procedures for model calibration and a criterion,the Akaike Information Criterion,of model selection based on experimental data are *** derivation,practical technique of computation and use of this criterion are detailed.

关键词： Collection of models model calibration model selection Akaike information criterion

Switched forced SEIRDV compartmental models to monitor COVID-19 spread and immunization in Italy

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Infectious Disease modelling 2022年第1期7卷 1-15页

作者： Erminia Antonelli Elena Loli Piccolomini Fabiana Zama Department of Mathematics University of BolognaItaly Department of Computer Science and Engineering University of BolognaItaly

This paper presents a new hybrid compartmental model for studying the COVID-19 epidemic evolution in Italy since the beginning of the vaccination campaign started on 2020/12/27 and shows forecasts of the epidemic evolution in Italy in the first six *** proposed compartmental model subdivides the population into six compartments and extends the SEIRD model proposed in[*** and ***,PLOS ONE,15(8):1e17,082020]by adding the vaccinated population and framing the global model as a hybridswitched dynamical *** to represent the quantities that characterize the epidemic behaviour from an accurate fit to the observed data,we partition the observation time interval into *** model parameters change according to a switching rule depending on the data behaviour and the infection rate continuity *** particular,we study the representation of the infection rate both as linear and exponential piecewise continuous *** choose the length of sub-intervals balancing the data fit with the model complexity through the Bayesian Information *** tested the model on italian data and on local data from Emilia-Romagna *** calibration of the model shows an excellent representation of the epidemic behaviour in both *** days forecasts have proven to well reproduce the infection spread,better for regional than for national *** models produce accurate predictions of infected,but the exponential-based one perform better in most of the ***,we discuss different possible forecast scenarios obtained by simulating an increased vaccination rate.

关键词： Compartmental model with vaccine SEIRDV Switched model Hybrid model Forcing function model calibration

Seismic Vulnerability Assessment from Earthquake Damages Historical Data Using Constrained Optimization Technique

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Journal of Geoscience and Environment Protection 2018年第2期6卷 89-111页

作者： Abed Benaichouche Caterina Negulescu Olivier Sedan Zohra Boutaraa BRGM(French Geological Survey) OrléansFrance Materials Sciences and Environment Laboratory Hassiba Ben Bouali University of ChlefChlefAlgeria

This present work falls within the context of efforts that have been made over the past many years, aimed in improving the seismic vulnerability modelling of structures when using historical data. The historical data describe the intensity and the damages, but do not give information about the vulnerability, since only in the ’90 the concept of vulnerability classes was introduced through the EMS92 and EMS98 scales. Considering EMS98 definitions, RISK-UE project derived a method for physical damage estimation. It introduced an analytical equation as a function of an only one parameter (Vulnerability Index), which correlates the seismic input, in term of Macroseismic Intensity, with the physical damage. In this study, we propose a methodology that uses optimization algorithms allowing a combination of theoretical-based with expert opinion-based assessment data. The objective of this combination is to estimate the optimal Vulnerability Index that fits the historical data, and hence, to give the minimum error in a seismic risk scenario. We apply the proposed methodology to the El Asnam earthquake (1980), but this approach remains general and can be extrapolated to any other region, and more, it can be applied to predictive studies (before each earthquake scenarios). The mathematical formulation gives choice for regarding, to the optic of minimizing the error, either for the: 1) very little damaged building (D0-D2 degree) or 2) highly damaged building (D4-D5 degree). These two different kinds of optics are adapted for the people who make organizational decisions as for mitigation measures and urban planning in the first case and civil protection and urgent action after a seismic event in the second case. The insight is used in the framework of seismic scenarios and offers advancing of damage estimation for the area in which no recent data, or either no data regarding vulnerability, are available.

关键词： Seismic Damage Scenario Damage Database Vulnerability Assessment Inverse Optimization model calibration El Asnam Earthquake RISK-UE

Assessment of the Sensitivity of Streamflow Simulations to Changes in Patch Resolution Using GIS Based Hydro-Ecologic model

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Open Journal of Modern Hydrology 2016年第2期6卷 66-78页

作者： Samson G. Mengistu Melkamu A. Ali Fuad A. Yassin National Hydrology Research Center Environment Canada Saskatoon Canada Global Institute for Water Security University of Saskatchewan Saskatoon Canada

Eight different patch configurations were investigated to analyze the effect of patch characterization/formation in streamflow simulation, using the Regional Hydro-Ecologic Simulation Systems (RHESSys) model. It is investigated for eight different patch configurations of a subcatchment of the Turkey Lakes Watershed, Ontario. The model’s hydrological parameters are calibrated for each of these patch configurations and the performance of the simulations is evaluated. Results indicate that both the nature of the flow simulation and the calibrated parameter values are sensitive to patch configuration. The best simulation results were obtained for the patch configuration with the highest spatial variation of climate, stream network and hillslope conditions across the subcatchment. Different patch configurations also lead to markedly different calibrations of the model’s hydrological parameters (54.26 < k < 119.13;and 1.02 < m < 2.28), which has implications for the physical interpretation and transferability of the calibrated parameter values.

关键词： RHESSys Patch model calibration Flow Simulation

modeling Preparative Chromatographic Separation of Heavy Rare Earth Elements and Optimization of Thulium Purification

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Advances in Materials Physics and Chemistry 2015年第5期5卷 151-160页

作者： Mark Max-Hansen Hans-Kristian Knutson Christian Jonsson Marcus Degerman Bernt Nilsson Department of Chemical Engineering Lund UniversityLundSweden

Rare Earth Elements are in growing demand globally. This paper presents a case study of applied mathematical modeling and multi objective optimization to optimize the separation of heavy Rare Earth Elements, Terbium-Lutetium, by means of preparative solid phase extraction chromatography, which means that an extraction ligand, HDEHP, is immobilized on a C18 silica phase, and nitric acid is used as an eluent. An ICP-MS was used for online detection of the Rare Earths. A methodology for calibration and optimization is presented, and applied to an industrially relevant mixture. Results show that Thulium is produced at 99% purity, with a productivity of 0.2 - 0.5 kg Tm per m3 stationary phase and second, with Yields from 74% to 99%.

关键词： Rare Earth Elements Chromatography model calibration Optimization Multi-Objective HDEHP

A Distance Measurement Method Based on Dual-parallel-line Projection for A Non-parameter Shooting System

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A Distance Measurement Method Based on Dual-parallel-line Pr...