environmental model Articles | Environmental XPRT

Space, economy and the environment: Danish studies

The paper makes a brief presentation of selected research in the field of space, economy and the environment, as of 1998. The paper first reviews the reasons for strong Danish interest in these issues. Then, spatial issues are reviewed and Danish studies presented. In particular, distinction is made between environment-economy models as pre-models which treat environmental change and regulation ...

Feb. 4, 2004

By Inderscience Publishers

Probability density estimation in stochastic environmental models using reverse representations

The estimation of probability densities of variables described by stochastic differential equations has long been done using forward time estimators, which rely on the generation of forward in time realizations of the model. Recently, an estimator based on the combination of forward and reverse time estimators has been developed. This estimator has a higher order of convergence than the classical ...

Nov. 20, 2005

By Springer-Verlag GmbH

A survey of material flows in economic models

Various types of economic model address environmental problems. This article examines whether these can be applied to the analysis of material flows. It is important to know which types of model are most suitable to deal with particular economic, environmental or physical aspects of material flows. For this purpose five main categories of models are considered, namely economic models of natural ...

May 11, 2004

By Inderscience Publishers

On the numerical asymmetry in calculating Coriolis terms through the splitting method in a mesoscale model

The asymmetry in calculating the Coriolis terms by Marchuk's splitting method is discussed. It was found that although some asymmetry is required for linear stability, this asymmetry should be kept to a minimum. Otherwise, for instance, if the diffusion terms are calculated in between the Coriolis terms in the u and v equations of motion, one gets cross-isobaric low-level winds, which are ...

Feb. 14, 2008

By Inderscience Publishers

Improved environmental multimedia modeling and its sensitivity analysis

Modeling of multimedia environmental issues is extremely complex due to the intricacy of the systems with the consideration of many factors. In this study, an improved environmental multimedia modeling is developed and a number of testing problems related to it are examined and compared with each other with standard numerical and analytical methodologies. The results indicate the flux output of ...

Jan. 1, 2011

By IWA Publishing

Environmental modelling for blue collars

Model complexity and the breakpoint of diminishing returns; physical vs. conceptual modelling; the relevance and limits of the heuristic solutions; screening vs. analytical modelling; perceptions of uncertainties, calibration and sensitivity analysis; and the ethics in modelling – are only a few issues outstanding in the volatile philosophy of the environmental modelling. Glossing on ...

Feb. 20, 2012

By Inderscience Publishers

A grey-encoded hybrid accelerating genetic algorithm for parameter optimisation of environmental models

A new method, grey-encoded hybrid accelerating genetic algorithm, is presented for the parameter optimisation of environmental models. With the shrinking of searching range, the method gradually directs to optimal result with the excellent individuals obtained by grey genetic algorithm embedding Nelder-Mead simplex searching operator. The convergence theorem is given for guaranteeing the global ...

Nov. 7, 2006

By Inderscience Publishers

Chapter 5: Energy-economy-environmental models with special reference to CO_{2 emission control}

As a consequence of the modelling exercise in Chapters 2–4, the question arises as to how these models could be extended and improved for large-scale use in the analysis of more detailed, more specific policy options. Before we suggest extensions, generalisations and ramifications of such models for more policy-directed use, we review the state of the art of energy modelling and attempt to derive ...

Jan. 26, 2004

By Inderscience Publishers

Multi-variable sensitivity and identifiability analysis for a complex environmental model in view of integrated water quantity and water quality modeling

Environmental models are often over-parameterized. A sensitivity analysis can identify influential model parameters for, e.g. the parameter estimation process, model development, research prioritization and so on. This paper presents the results of an extensive study of the Latin-Hypercube–One-factor-At-a-Time (LH-OAT) procedure applied to the Soil and Water Assessment Tool (SWAT). The LH-OAT is ...

Jan. 1, 2012

By IWA Publishing

Application of model trees and other machine learning techniques for algal growth prediction in Yongdam reservoir, Republic of Korea

A promising new approach for eco-environmental modelling, such as algal growth prediction, is the data-driven modeling using machine learning techniques: an artificial neural network (ANN) being a typical method. Another method growing in popularity, based on the M5 model tree (MT) algorithm, is the use of piecewise linear regression models at the leaf nodes of the tree. M5 MTs using partial ...

Jul. 1, 2010

By IWA Publishing

Different splitting techniques with application to air pollution models

Splitting techniques are commonly used when large-scale models, which appear in different fields of science and engineering, are treated numerically. Four types of splitting procedures are defined and discussed. The problem of the choice of a splitting procedure is investigated. Several numerical tests, by which the influence of the splitting errors on the accuracy of the results is studied, are ...

Feb. 14, 2008

By Inderscience Publishers

State of the art of air pollution models, needs and trends

This paper summarises the results of the investigations within task MA3-2 carried out by the European Topic Centre on Air Quality. The main aim of this task is to describe the state of the art of air pollution models, with special emphasis on needs for model application and trends in model development. From the results it can be inferred to what extent the needs are met by available models and ...

Sep. 15, 2009

By Inderscience Publishers

Canarina RADIA · electromagnetic pollution modelling · introduction 1

1. Introduction Software for analysis of electromagnetic pollution in environment: environmental modeling, environmental impact assessment, environmental engineering, environmental consultancy service and environment simulation. RADIA is a electromagnetic pollution modeling software. The program calculates the elecromagnetic pollution in each point of the air considering each one of the ...

Nov. 27, 2011

By Canarina Environmental Software

What's in a Model? More Than You Think

Untitled Document The use of complex mathematical models is central to the U.S. Environmental Protection Agency’s (EPA’s) decision-making process. It is generally impractical to obtain measured data to support the many scenarios involved in environmental decision-making. Thus, EPA relies heavily upon models for a host of applications, including estimating ...

Dec. 1, 2003

By Bergeson & Campbell, P.C.

Environmental effects of transport: a model of optimal pricing and investment for the UK

This paper models the effects of imposing efficient pricing on interurban passenger travel in the United Kingdom and passenger travel in London. Both the internal and external costs of the main modes are estimated. The resulting efficient prices are used to predict the changes in demand for each mode, together with implied tax revenues, operators' aggregate surplus or deficit, and the implied ...

Sep. 16, 2009

By Inderscience Publishers

On efficient numerical solution of one-dimensional convection?diffusion equations in modelling atmospheric processes

A new approach is proposed to the numerical solution of one-dimensional convection?diffusion equations that arise in modelling atmospheric processes and air pollution modelling. The technique is based on upstream-type difference approximations for first-order derivatives and non-standard difference approximations for second-order derivatives of convection?diffusion equations. This approach leads ...

Feb. 14, 2008

By Inderscience Publishers

Probabilistic policy experiments: the use of energy economic environmental models in the climate change policy process

This paper uses the Edmonds-Reilly model to explore an alternative approach for using energy-economic-environmental models when analyzing future CO2 emissions. This approach – conducting probabilistic policy experiments – can be used to investigate the effectiveness of various policy options in the context of uncertainty. The analysis builds on work by Nordhaus and Yohe (1983) and ...

Sep. 17, 2009

By Inderscience Publishers

Canarina CUSTIC software · environmental noise modeling · algorithms 4

In the railway case, we shall calculate the noise level in a similar way. For airports, we shall use the next equation Leq=Leq(300m)-20Log(r/300) where Leq(300m) is the noise level at 300m from the airport. This model performs satisfactorily for simple sound propagations with no ground interaction or attachment. The application will not consider sound reflections in the ground surface. ...

Nov. 20, 2011

By Canarina Environmental Software

Histo-blood group antigen assay for detecting noroviruses in water

We evaluated a novel, magnetic-bead-based histo-blood group antigen assay for the recovery of low numbers of norovirus particles. Using this assay, with Norwalk virus seeded in environmental waters as a model, we were able to recover 30 to 300 genomic copies of the virus. ...

Aug. 28, 2008

By American Society for Microbiology (ASM)

On numerical solver selection and related uncertainty terminology

Mathematical models provide insight into numerous biological, physical and chemical systems. They can be used in process design, optimisation, control and decision support, as acknowledged in many different fields of scientific research. Mathematical models do not always yield reliable results and uncertainty should be taken into account. At present, it is possible to identify some factors ...

Jan. 7, 2010

By IWA Publishing