Home About us Contact
|
Home About us Contact | ||
|
|
||
Illustrative Purposes (illustrative + purpose)
Selected AbstractsA finite element algorithm for parameter identification of material models for fluid saturated porous mediaINTERNATIONAL JOURNAL FOR NUMERICAL AND ANALYTICAL METHODS IN GEOMECHANICS, Issue 5 2001R. Mahnken Abstract In this contribution an algorithm for parameter identification of geometrically linear Terzaghi,Biot-type fluid-saturated porous media is proposed, in which non-uniform distributions of the state variables such as stresses, strains and fluid pore pressure are taken into account. To this end a least-squares functional consisting of experimental data and simulated data is minimized, whereby the latter are obtained with the finite element method. This strategy allows parameter identification based on in situ experiments. In order to improve the efficiency of the minimization process, a gradient-based optimization algorithm is applied, and therefore the corresponding sensitivity analysis for the coupled two-phase problem is described in a systematic manner. For illustrative purpose, the performance of the algorithm is demonstrated for a slope stability problem, in which a quadratic Drucker,Prager plasticity model for the solid and a linear Darcy law for the fluid are combined. Copyright © 2001 John Wiley & Sons, Ltd. [source] Waste management modeling with PC-based model , EASEWASTEENVIRONMENTAL PROGRESS & SUSTAINABLE ENERGY, Issue 1 2008Gurbakhash S. Bhander Abstract As life-cycle-thinking becomes more integrated into waste management, quantitative tools are needed for assessing waste management systems and technologies. This article presents a decision support model to deal with integrated solid waste management planning problems at a regional or national level. The model is called EASEWASTE (environmental assessment of solid waste systems and technologies). The model consists of a number of modules (submodels), each describing a process in a real waste management system, and these modules may combine to represent a complete waste management system in a scenario. EASEWASTE generates data on emissions (inventory), which are translated and aggregated into different environmental impact categories, e.g. the global warming, acidification, and toxicity. To facilitate a "first level" screening evaluation, default values for process parameters have been provided, wherever possible. The EASEWASTE model for life-cycle-assessment of waste management is described and applied to a case study for illustrative purposes. The case study involving hypothetical but realistic data demonstrates the functionality, usability, and flexibilities of the model. The design and implementation of the software successfully address the substantial challenges in integrating process modeling, life-cycle inventory (LCI), and impact assessment (LCIA) modeling, and optimization into an interactive decision support platform. © 2008 American Institute of Chemical Engineers Environ Prog, 2008 [source] Living with anorexia nervosa: the experience of a cohort of sufferers from anorexia nervosa 7.5 years after initial presentation to a specialized eating disorders serviceEUROPEAN EATING DISORDERS REVIEW, Issue 2 2001Eric J. Button Abstract Objective The main aim of the present study was to further understand how sufferers from anorexia nervosa view the disorder, how it affects their lives and how they experience treatment and help. Method A cohort of anorectic patients were followed up 7.5 years after presentation at a specialist locally-based eating disorders service for adults. All subjects were invited to take part in a semi-structured interview and complete a series of questionnaires. Results Thirty-six subjects were interviewed and the group as a whole showed marked improvement compared with initial presentation, but only 14 per cent were judged to be free of the disorder and about one-quarter remained entrenched in the world of anorexia nervosa. The main results focus on common themes which emerged from the interview and extensive quotes from subjects are used for illustrative purposes. Although each person expressed a very individual experience of the disorder, a common theme was of it emerging as a response to a sense of loss of control in one or more areas of their lives, often centering on their self-image and problems in relationships with others. Although the disorder was commonly experienced as having a devastating effect on their lives, the focus on weight and eating at least offered them some semblance of control. A wide range of experiences of treatment were reported, but there was considerable consensus regarding the importance of individual psychotherapy/counselling and of the quality of relationship with a therapist. Discussion This study confirms the often long-term psychological problems experienced by sufferers from anorexia nervosa and helps to illuminate the client's perspective on the disorder and other people's attempts to help. The individual views of the sufferer are an important consideration for those involved in the planning and delivery of services for these vulnerable people. Copyright © 2001 John Wiley & Sons, Ltd and Eating Disorders Association. [source] Sensitivity analysis of prior model probabilities and the value of prior knowledge in the assessment of conceptual model uncertainty in groundwater modellingHYDROLOGICAL PROCESSES, Issue 8 2009Rodrigo Rojas Abstract A key point in the application of multi-model Bayesian averaging techniques to assess the predictive uncertainty in groundwater modelling applications is the definition of prior model probabilities, which reflect the prior perception about the plausibility of alternative models. In this work the influence of prior knowledge and prior model probabilities on posterior model probabilities, multi-model predictions, and conceptual model uncertainty estimations is analysed. The sensitivity to prior model probabilities is assessed using an extensive numerical analysis in which the prior probability space of a set of plausible conceptualizations is discretized to obtain a large ensemble of possible combinations of prior model probabilities. Additionally, the value of prior knowledge about alternative models in reducing conceptual model uncertainty is assessed by considering three example knowledge states, expressed as quantitative relations among the alternative models. A constrained maximum entropy approach is used to find the set of prior model probabilities that correspond to the different prior knowledge states. For illustrative purposes, a three-dimensional hypothetical setup approximated by seven alternative conceptual models is employed. Results show that posterior model probabilities, leading moments of the predictive distributions and estimations of conceptual model uncertainty are very sensitive to prior model probabilities, indicating the relevance of selecting proper prior probabilities. Additionally, including proper prior knowledge improves the predictive performance of the multi-model approach, expressed by reductions of the multi-model prediction variances by up to 60% compared with a non-informative case. However, the ratio between-model to total variance does not substantially decrease. This suggests that the contribution of conceptual model uncertainty to the total variance cannot be further reduced based only on prior knowledge about the plausibility of alternative models. These results advocate including proper prior knowledge about alternative conceptualizations in combination with extra conditioning data to further reduce conceptual model uncertainty in groundwater modelling predictions. Copyright © 2009 John Wiley & Sons, Ltd. [source] Localization , an alternative to corporate-led globalizationINTERNATIONAL JOURNAL OF CONSUMER STUDIES, Issue 4 2003Caroline Lucas In the aftermath of 11 September, there has been a growing recognition that an increasingly unequal world is not only morally unacceptable but also deeply insecure. This paper defines globalization as economic, corporate-led globalization, a process that impacts every facet of our life. For illustrative purposes, this paper will briefly examine the role played by the globalization process in exacerbating the gap between rich and poor. It will make the case that, contrary to popular wisdom, there is nothing inevitable about this process. One such alternative is localization , a set of interrelated and self-reinforcing policies that actively discriminate in favour of the more local, whenever it is feasible and reasonable. [source] Quantifying Fluid Mixing with the Shannon EntropyMACROMOLECULAR THEORY AND SIMULATIONS, Issue 8 2006Marco Camesasca Abstract Summary: We introduce a methodology to quantify the quality of mixing in various systems, including polymeric ones, by adapting the Shannon information entropy. For illustrative purposes we use particle advection of two species in a two-dimensional cavity flow. We compute the entropy by using the probability of finding a suitable chosen group/complex of particles of a given species, at a given location. By choosing the size of the group to be in direct proportion to the overall concentration of the components in the mixture we ensure that the entropic measure is maximized for the case of perfect mixing, that is, when at each location the component concentration is equal to the corresponding overall component concentrations. The scale of observation role in evaluating mixing is analyzed using the entropic methodology. We also illustrate the effect of initial conditions on mixing in a laminar system, typical in operations involving polymers. [source] Robust Design of Fault Detection and Isolation SystemsQUALITY AND RELIABILITY ENGINEERING INTERNATIONAL, Issue 5 2006Daniele Romano Abstract Inspired by the rationale of Robust Design, a novel methodology is presented for the design of diagnostic systems for fault detection and isolation (FDI). Detection/isolation capability and robustness, i.e. sensitivity to faults and insensitivity to noise, are addressed in an integrated way within a fully stochastic framework. Although FDI is a classical problem in control engineering, this new approach improves the current state of the art both in terms of general applicability and optimality of the design solution. It demonstrates the potential of robust design in fostering innovation in a variety of technical sectors. For illustrative purposes, the methodology is applied to the design of a FDI system for a fluid mixer. Copyright © 2006 John Wiley & Sons, Ltd. [source] | ||||||||||