Search results for " Monitoring"
showing 10 items of 3129 documents
Proof of Concept of an Irradiance Estimation System for Reconfigurable Photovoltaic Arrays
2015
In order to reduce the mismatch effect caused by non-uniform shadows in PV arrays, reconfigurable interconnections approaches have been recently proposed in the literature. These systems usually require the knowledge of the solar radiation affecting every solar module. The aim of this work is to evaluate the effectiveness of three irradiance estimation approaches in order to define which can be well suited for reconfigurable PV arrays. It is presented a real-time solar irradiance estimation device (IrradEst), implementing the three different estimation methods. The proposed system is based on mathematical models of PV modules enabling to estimate irradiation values by sensing a combination …
Compressive sensing for direct time of flight estimation in ultrasound-based NDT
2017
This paper presents an approach for estimation of ultrasonic time-of-flight (TOF) within a Non Destructive Testing (NDT) and Structural Health Monitoring (SHM) context. The presented method leverages recent advances in the field of Compressive Sensing (CS), which makes use of sparsity in a transform domain of a signal in order to reduce the number of samples required to store it. CS achieves this through a two key ideas: random matrix projections, and l1-penalised linear regression. In this case, sparsity arises from the observation that in a pulse-echo ultrasound test, the number of echoes is relatively small compared to the number of measurement points in a waveform. This sparsity is evid…
The potential of rotorcraft for intercity passenger transport
2007
Abstract There are many high-speed rail projects in Europe at different stages of development. They are supported on environmental grounds and as a means of reducing congestion on other modes, including aviation. High-speed rail, however requires major investment costs, takes a long time to come online, and involves considerable financial risks. A potential alternative that overcomes some of these problems makes use of rotorcrafts. This paper assesses the potentiality of civil rotorcrafts as part of the air transport system. Discrete mode choice models are used to forecast traveller choice behaviour when the rotorcraft is introduced and financial evaluations performed looking at the operati…
Effects of circular openings on the compressive behaviour of R.C. columns
2014
Core-drilling technique is nowadays always more frequently performed in existing reinforced concrete (RC) structures in order to investigate on the mechanical properties of concrete and for structural health monitoring purposes. Even if the engineering practice discourages to drill columns, this can be often unavoidable. In this last case the presence of the circular opening influences the compressive behavior of the column in terms of load-carrying capacity and axial deformability. The goal of this investigation was the experimental evaluation of the effects induced by circular openings on the behavior of RC columns. Twenty-four reinforced and plain concrete prisms in presence of circular …
The effectiveness of the Finnish EIA system — What works, what doesn't, and what could be improved?
2011
Abstract The article summarises the results of a multidisciplinary research project on the effectiveness of the Finnish EIA system. It examines the main strengths and weaknesses of EIA as a preventive and participatory environmental management tool. The study concludes that EIA has achieved a meaningful role in the environmental policy toolbox in Finland and has clearly enhanced the possibilities for high-quality environmental decision making. The research cites the liaison authority system as a clear strength of the Finnish EIA system in its enabling a single regional authority to specialise in and gain wide experience on EIA issues. In examining potential weaknesses of the regime, the art…
Testing the usability of the Rapid Impact Assessment Matrix (RIAM) method for comparison of EIA and SEA results
2008
Abstract This study examines how the results of Environmental Impact Assessment (EIA) and Strategic Environmental Assessment (SEA) could be compared using the Rapid Impact Assessment Matrix (RIAM) method. There are many tools and techniques that have been developed for use in impact assessment processes, including scoping, checklists, matrices, qualitative and quantitative models, literature reviews, and decision-support systems. While impact assessment processes have become more technically complicated, it is recognized that approaches including simpler applications of available tools and techniques are also appropriate. The Rapid Impact Assessment Matrix (RIAM) is a tool for organizing, a…
Applying complexity science to air traffic management
2015
Versión aceptada obtenida del archivo digital en línea WestminsterResearch de la Universidad de Westminster. Complexity science is the multidisciplinary study of complex systems. Its marked network orientation lends itself well to transport contexts. Key features of complexity science are introduced and defined, with a specific focus on the application to air traffic management. An overview of complex network theory is presented, with examples of its corresponding metrics and multiple scales. Complexity science is starting to make important contributions to performance assessment and system design: selected, applied air traffic management case studies are explored. The important contexts of…
Efficiency assessment of wastewater treatment plants: A data envelopment analysis approach integrating technical, economic, and environmental issues
2015
The assessment of the efficiency of wastewater treatment plants (WWTPs) is essential to compare their performance and consequently to identify the best operational practices that can contribute to the reduction of operational costs. Previous studies have evaluated the efficiency of WWTPs using conventional data envelopment analysis (DEA) models. Most of these studies have considered the operational costs of the WWTPs as inputs, while the pollutants removed from wastewater are treated as outputs. However, they have ignored the fact that each pollutant removed by a WWTP involves a different environmental impact. To overcome this limitation, this paper evaluates for the first time the efficien…
Life cycle assessment of Italian citrus-based products. Sensitivity analysis and improvement scenarios
2009
Though many studies concern the agro-food sector in the EU and Italy, and its environmental impacts, literature is quite lacking in works regarding LCA application on citrus products. This paper represents one of the first studies on the environmental impacts of citrus products in order to suggest feasible strategies and actions to improve their environmental performance. In particular, it is part of a research aimed to estimate environmental burdens associated with the production of the following citrus-based products: essential oil, natural juice and concentrated juice from oranges and lemons. The life cycle assessment of these products, published in a previous paper, had highlighted sign…
Assessing the productivity change of water companies in England and Wales: A dynamic metafrontier approach
2017
The assessment of productivity change and its drivers across water companies and over time is a powerful tool for both regulators and companies when setting water tariffs. Water and sewerage companies (WaSCs) and water only companies (WoCs) provide different services. Hence, their productivity change cannot directly be evaluated jointly. In this paper and for the first time, we provide a pioneering approach to assess and compare the dynamics of productivity change of WaSCs and WoCs. To achieve this, both the traditional Malmquist productivity index and the metafrontier Malmquist productivity index and its components are computed to assess the productivity change for a sample of English and …