Search results for "Rankin"
showing 10 items of 259 documents
Parameter subset selection for the dynamic calibration of activated sludge models (ASMs): experience versus systems analysis.
2007
In this work we address the issue of parameter subset selection within the scope of activated sludge model calibration. To this end, we evaluate two approaches: (i) systems analysis and (ii) experience-based approach. The evaluation has been carried out using a dynamic model (ASM2d) calibrated to describe nitrogen and phosphorus removal in the Haaren WWTP (The Netherlands). The parameter significance ranking shows that the temperature correction coefficients are among the most influential parameters on the model output. This outcome confronts the previous identifiability studies and the experience based approaches which excluded them from their analysis. Systems analysis reveals that parame…
A novel hybrid polygeneration system supplying energy and desalinated water by renewable sources in Pantelleria Island
2017
Abstract In this paper a thermoeconomic analysis of a novel hybrid Renewable Polygeneration System connected to a district heating and cooling network is presented. The plant is powered simultaneously by solar and geothermal sources, producing electricity, desalinated water, heat and cooling energy. System layout includes Parabolic Through Collector (PTC) field, geothermal wells, Organic Rankine Cycle (ORC) unit and a Multi-Effect Desalination (MED) system. Cooling and thermal demands are calculated by suitable building dynamic simulation models, calibrated for Pantelleria Island. Electrical demand is obtained by measured data. A detailed control strategy has been implemented in order to pr…
Success factors for information technology supported international technology transfer: Finding expert consensus
2006
Information technology (IT)-supported international technology transfer (ITT) is complex, risky, and fails often. No empirical studies are available on the factors that affect the success of IT-supported ITT. We review applicable theories (i.e. diffusion of innovation theory) and empirical research in conventional technology transfer to develop such a model. We carry out a multiple focus group method to rank factors that affect the success of IT-supported ITT and then apply a branch and bound method to derive a consensus ranking of these factors. The identified consensus ranking sheds light on factors that are similar to those of DOI theory and suggests a pattern of factors that affect IT-s…
The Multicriteria Electre III Model Applied to the Evaluation of the Placement of University Graduates
2010
During the last years the Italian university system has been undergoing a reform process regarding issues of governance such as the progressive financial autonomy of the University (art. 5, law 537/24 December 1993) and the reshape of the academic curricula (law 509/99 and 270/04). The most obvious result of this complex process has been the challenging attempt to manage a necessary change in a context of limited financial resources. In order to encompass the composite features of an efficient and effective management of resources, features of high relevance for the full accomplishment of the reform benchmarks, one has to take into account the academic organisation’s objectives, so that to …
fuzzy approach to the robust facility layout in uncertain production environments
2001
The proposed method approaches the problem of the optimal facility layout using fuzzy theory. The optimal layout is a robust layout that minimizes the total material handling cost, when the product market demands are uncertain variables, which are defined as fuzzy numbers. Since each department has a limited production capacity, not all possible combinations, deriving from each product's market demand, are taken into account because some combination could exceed the overall department's productivity. Therefore, the optimal solution results by solving a 'constrained' fuzzy optimization problem, in which the fuzzy material handling costs corresponding to the layouts are evaluated, and a ranki…
Application of the Morris method for screening the influential parameters of fuzzy controllers applied to wastewater treatment plants
2011
In this paper,we evaluate the application of a sensitivity analysis to help fine-tuning a fuzzy controller for a biological nitrogen and phosphorus removal (BNPR) plant. TheMorris Screeningmethod is proposed and evaluated as a prior step to obtain the parameter significance ranking. First, an iterative procedure has been performed in order to find out the proper repetition number of the elementary effects (r) of the method. The optimal repetition number found in this study (r = 60) is in direct contrast to previous applications of the Morris method, which usually use low repetition number, e.g. r = 10 ~ 20. Working with a non-proper repetition number (r) could lead to Type I error (identify…
A novel solar-geothermal trigeneration system integrating water desalination: Design, dynamic simulation and economic assessment
2016
Abstract In this paper, an innovative solar-geothermal polygeneration system is investigated. The system supplies a small community with electricity, desalinated water and space heating and cooling through a district network. The hybrid multi-purpose plant, based on an Organic Rankine Cycle (ORC) supplied by medium-enthalpy geothermal energy and by solar energy; this latter is provided by Parabolic Trough Collectors (PTC). The geothermal brine is first used to drive the ORC loop, then to provide space heating at around 85÷90 °C (in the winter), or cooling (in the summer, by means of a single-effect absorption chiller). Finally, the geothermal brine drives a Multi-Effect Distillation (MED) s…
A combined multi-criteria approach to support FMECA analyses: A real-world case
2018
[EN] The paper proposes an approach that combines reliability analyses and multi-criteria decision methods to optimize maintenance activities of complex systems. A failure mode, effects, and criticality analysts (FMECA) is initially performed and the fuzzy TOPSIS (FTOPSIS) method is then applied to rank previously identified failure modes. For prioritization, failure modes are assessed against three evaluation criteria that differ from those traditionally involved in risk priority number (RPN) computation (i.e. severity, occurrence and detection). Two criteria refer to the maintenance management reflecting the operational time taken by the maintenance activity performed after the occurrence…
Decision making in energy planning: The electre multicriteria analysis approach compared to a fuzzy-sets methodology
1998
Every planning activity generally requires to make some choices. After a preliminary analysis of the sector under examination, a forecast of trends of input-output items, the planner must define an action plan voted to arrange all the strategies and specific interventions able to fit demand and supply during the planned time. The redaction of an action plan implies a strong effort in order to synthesize either suggestions coming from the analysis phases either all the constraints linked to technical choices. In the same time, a large number of "external" variables plays a role in orienting decision making. Some of these can be handled by numerical models (economic cost-benefit analyses, mar…
Ensemble methods for item-weighted label ranking: a comparison
2022
Label Ranking (LR), an emerging non-standard supervised classification problem, aims at training preference models that order a finite set of labels based on a set of predictor features. Traditional LR models regard all labels as equally important. However, in many cases, failing to predict the ranking position of a highly relevant label can be considered more severe than failing to predict a trivial one. Moreover, an efficient LR classifier should be able to take into account the similarity between the items to be ranked. Indeed, swapping two similar elements should be less penalized than swapping two dissimilar ones. The contribution of the present paper is to formulate more flexible item…