499 research outputs found
High resolution satellite imagery orientation accuracy assessment by leave-one-out method: accuracy index selection and accuracy uncertainty
The Leave-one-out cross-validation (LOOCV) was recently applied to the evaluation of High Resolution Satellite Imagery orientation accuracy and it has proven to be an effective method alternative with respect to the most common Hold-out-validation (HOV), in which ground points are split into two sets, Ground Control Points used for the orientation model estimation and Check Points used for the model accuracy assessment.
On the contrary, the LOOCV applied to HRSI implies the iterative application of the orientationmodel using all the known ground points as GCPs except one, different in each iteration, used as a CP. In every iteration the residual between imagery derived coordinates with respect to CP coordinates (prediction error of the model on CP coordinates) is calculated; the overall spatial accuracy achievable from the oriented image may be estimated by computing the usual RMSE or, better, a robust accuracy index like the mAD (median Absolute Deviation) of prediction errors on all the iterations.
In this way it is possible to overcome some drawbacks of the HOV: LOOCVis a reliable and robustmethod, not dependent on a particular set of CPs and on possible outliers, and it allows us to use each known ground point both as a GCP and as a CP, capitalising all the available ground information. This is a crucial problem in current situations, when the number of GCPs to be collected must be reduced as much as possible for obvious budget problems. The fundamentalmatter to deal with was to assess howwell LOOCVindexes (mADand RMSE) are able to represent the overall accuracy, that is howmuch they are stable and close to the corresponding HOV RMSE assumed as reference. Anyway, in the first tests the indexes comparison was performed in a qualitative way, neglecting their uncertainty. In this work the analysis has been refined on the basis of Monte Carlo simulations, starting from the actual accuracy of ground points and images coordinates, estimating the desired accuracy indexes (e.g. mAD and RMSE) in several trials, computing their uncertainty (standard deviation) and accounting for them in the comparison.
Tests were performed on a QuickBird Basic image implementing an ad hoc procedure within the SISAR software developed by the Geodesy and Geomatics Team at the Sapienza University of Rome. The LOOCV method with accuracy evaluated by mAD seemed promising and useful for practical case
Key performance indicators of ‘good practices’ of energy efficiency in industry: application to real cases in Italy and in the European Union
With the publication of the Energy Efficiency Directive (EED) in 2012, energy savings in the Industry processes have gained more and more importance in the European Union (EU). Industry (with building and transport) is one of the three main sectors where Energy consumption and efficiency play a fundamental role, to accomplish the EU energy objectives. Many countries in EU have already adopted schemes and mechanisms to implement the Directive: however deep differences of approaches still remain among the Member States (MSs), especially with respect to the identification of the real benefits of measures and to the assessment of their efficiency and sustainability. As a consequence, a huge amount of the efficiency potential still remains untapped. This paper proposes some criteria for the evaluation of the applied Energy Efficiency measures, leading to the identification of Good Practices of Energy Efficiency. These criteria are taken from the ‘real world’ of industry, and are susceptible to be replicated in other contexts (e.g. different sectors or other countries). The proposed criteria have been developed in the EU H2020 project EU MERCI (nr 693845) and through a national research (part of the ‘Ricerca di Sistema’ national funding system) both coordinated by RSE. The starting point is the harmonization of data sets related to projects developed in different EU countries within local efficiency implementation schemes. The second step is the definition of Key Performance Indicators (KPIs) reflecting the impact of measures against Energy, Environment and Economic aspects. The last step is the extraction of efficiency ‘Good Practices’ ranked according to the identified KPIs and other factors, including social elements. The real added value of this approach is that it is full based on tangibly implemented projects, in opposition to similar attempts, essentially theoretical. Ultimately, it offers a key of assessment of the effectiveness of efficiency measures implementing local and EU policies
ALMA Band 9 upgrade: a feasibility study
We present the results of a study on the feasibility of upgrading the
existing ALMA Band 9 receivers (602-720 GHz). In the current configuration,
each receiver is a dual channel heterodyne system capable of detecting
orthogonally polarized signals through the use of a wire grid and a compact
arrangement of mirrors. The main goals of the study are the upgrade of the
mixer architecture from Double-Sideband (DSB) to Sideband-separating (2SB), the
extension of the IF and RF bandwidth, and the analysis of the possibilities of
improving the polarimetric performance. We demonstrate the performance of 2SB
mixers both in the lab and on-sky with the SEPIA660 receiver at APEX, which
shows image rejection ratios exceeding 20 dB and can perform successful
observations of several spectral lines close to the band edges. The same
architecture in ALMA Band 9 would lead to an increase in the effective spectral
sensitivity and a gain of a factor two in observation time. We set up also an
electromagnetic model of the optics to simulate the polarization performance of
the receivers, which is currently limited by the cross-polar level and the beam
squint, i.e. pointing mismatch between the two polarizations. We present the
results of the simulations compared to the measurements and we conclude that
the use of a polarizing grid is the main responsible of the limitations.Comment: to appear in Proc. of the mm Universe 2023 conference, Grenoble
(France), June 2023, published by F. Mayet et al. (Eds), EPJ Web of
conferences, EDP Science
Fluorescence suppression using micro-scale spatially offset Raman spectroscopy
We present a new concept of fluorescence suppression in Raman microscopy based on micro-spatially offset Raman spectroscopy which is applicable to thin stratified turbid (diffusely scattering) matrices permitting the retrieval of the Raman signals of sublayers below intensely fluorescing turbid over-layers. The method is demonstrated to yield good quality Raman spectra with dramatically suppressed fluorescence backgrounds enabling the retrieval of Raman sublayer signals even in situations where conventional Raman microscopy spectra are fully overwhelmed by intense fluorescence. The concept performance was studied theoretically using Monte Carlo simulations indicating the potential of up to an order or two of magnitude suppression of overlayer fluorescence backgrounds relative to the Raman sublayer signals. The technique applicability was conceptually demonstrated on layered samples involving paints, polymers and stones yielding fluorescence suppression factors between 12 to above 430. The technique has potential applications in a number of analytical areas including cultural heritage, archaeology, polymers, food, pharmaceutical, biological, biomedical, forensics and catalytic sciences and quality control in manufacture
Analytical capability of defocused μ-SORS in the chemical interrogation of thin turbid painted layers
© The Author(s) 2015. A recently developed micrometer-scale spatially offset Raman spectroscopy (m-SORS) method provides a new analytical capability for investigating non-destructively the chemical composition of sub-surface, micrometer-scale thickness, diffusely scattering layers at depths beyond the reach of conventional confocal Raman microscopy. Here, we demonstrate experimentally, for the first time, the capability of μ-SORS to determine whether two detected chemical components originate from two separate layers or whether the two components are mixed together in a single layer. Such information is important in a number of areas, including conservation of cultural heritage objects, and is not available, for highly turbid media, from conventional Raman microscopy, where axial (confocal) scanning is not possible due to an inability to facilitate direct imaging within the highly scattering sample. This application constitutes an additional capability for μ-SORS in addition to its basic capacity to determine the overall chemical make-up of layers in a turbid system
‘Good Practices’ to Improve Energy Efficiency in the Industrial Sector
Since the introduction of the International Pollution Prevention and Control (IPPC) directive and of the Best Available Techniques Reference (BREF) documents, the best available techniques (BATs) have become a reference both for policies and for companies to compare performance and to identify investment opportunities. Due to the environmental core of the IPPC and the Industrial Emissions Directive (IED), energy efficiency (EE) BATs are not always detailed and often lack energy-performance indicators. The H2020 EU-MERCI project is aimed at fostering and facilitating the implementation of EE projects in the manufacturing industry sectors by selecting and disseminating technological and policy best practices. A set of EE ‘Good Practices’ (GPs) was developed considering both BREF indications and literature analysis, and as innovative approach the outcomes of EE obligation and support measures aimed at the industrial sector. This was implemented through an in-depth analysis of the existing schemes in four countries (Austria, Italy, Poland and UK) and a thorough activity to normalise and compare the data made available by the different schemes. The outcome is available through the European Industrial Energy Efficiency good Practices platform implemented by EU-MERCI Partners. On the platform, a database of EE projects implemented in industry under the existing schemes is available. The database is searchable by country, sector, supporting scheme, implementation year and company size. The complete list is also downloadable as Excel file. Besides, a library divided by sectors is available, in which it is possible to look for the available GPs (both BATs and projects implemented under the national schemes) for each phase of the manufacturing processes. Sectoral and national analyses are finally available. This article will illustrate the methodology used for the project and the main outcomes.This work has been funded partially by the Research Fund for Italian Electric System under the Contract Agreement between RSE and the Italian Ministry of Economic Development and partially by the European Commission under Grant Agreement No. 693845 (EU-MERCI project). The authors would like to thank the other project partners, especially AEA, KAPE, Carbon Trust, CRES and FIRE and the colleagues from RSE for the constant support
Sustainable but not spontaneous: Co-operatives and the solidarity funds in Italy
This paper aims to highlight the role of solidarity funds in the development and support of national co-operative movements. Those are financial institutions specialized in supporting the start-up and growth of co-operatives. By adopting a case study approach, our analysis shows that solidarity funds emerged globally with similar objectives. Our international comparison focuses on Italy but includes France, the United Kingdom and Québec as a specific Canadian province with a French institutional environment. Despite their crucial importance, there is limited available research on this subject. To this end, our paper has policy implications; we need to consider establishing such institutions in countries where co-operatives are lagging behind as traditional financial institutions are often unable to finance co-operatives because of their property rights regime
ALMA Band 9 upgrade: A feasibility study
We present the results of a study on the feasibility of upgrading the existing ALMA Band 9 receivers (602-720 GHz). In the current configuration, each receiver is a dual channel heterodyne system capable of detecting orthogonally polarized signals through the use of a wire grid and a compact arrangement of mirrors. The main goals of the study are the upgrade of the mixer architecture from Double-Sideband (DSB) to Sideband-separating (2SB), the extension of the IF and RF bandwidth, and the analysis of the possibilities of improving the polarimetric performance. We demonstrate the performance of 2SB mixers both in the lab and on-sky with the SEPIA660 receiver at APEX, which shows image rejection ratios exceeding 20 dB and can perform successful observations of several spectral lines close to the band edges. The same architecture in ALMA Band 9 would lead to an increase in the effective spectral sensitivity and a gain of a factor two in observation time. We set up also an electromagnetic model of the optics to simulate the polarization performance of the receivers, which is currently limited by the cross-polar level and the beam squint, i.e. pointing mismatch between the two polarizations. We present the results of the simulations compared to the measurements and we conclude that the use of a polarizing grid is the main responsible of the limitations
- …