1,135 research outputs found

    A long-term hydrological modelling of an extensive green roof by means of SWMM

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    Green roofs provide multiple environmental and social benefits, among which the opportunity to control storm water runoff as they limit the rate of runoff after urbanization to the rate that would have occurred before urban development. The hydrological behaviour of a green roof is site specific, thus the local environmental parameters, the characteristics of the vegetation and the physical properties of its layers have to be considered in the evaluation of its performance. Furthermore, the hydrological performance of a green roof is influenced by the size of the plot (full-scale vs small scale), by the definition of “event”, and by the number of events included in the research. From this broader context this paper first provides a review of the scientific literature, with a focus on the hydrological behaviour of experimental full-scale installations and on hydrological modelling of green roof performance. Second, the study presents the results of a monitoring activity of a full-scale extensive green roof in Bologna (Italy). Continuous weather data and runoff were collected between January and December 2014, resulting in 69 storm events suitable for the study. Experimental data show that single event rainfall attenuation ranged from 6.4% to 100% with an annual average value of 51.9% which is consistent with other author's findings. Last, the study uses the field data to calibrate and validate a numerical model realized with the commercial software SWMM 5.1. The model was used to simulate the long-term hydrologic response, over one year, of the same full-scale extensive green roof and to compare it to an adjacent impervious roof of the same size. Modelling results confirm the role of green roofs in restoring the natural water regime by reducing the annual runoff volume. The comparison of the results between the experimental green roof monitoring and the SWMM simulation proved that the suggested model has good capabilities in simulating the hydrograph of stormwater runoff from green roofs along the year, as demonstrated by the quite high values of NSE and the low value of RSR in both the calibration and validation phase. Furthermore, the low difference (< 9%) in total retention between the 69 measured and simulated events confirms the suitability of the model for long term simulations. The proposed modelling approach demonstrates that SWMM can be used for assessing the performance of LID systems (Low Impact Development), and consequently for supporting local authorities or designers in the evaluation of the hydrological efficiency of green roofs

    Experimental Infiltration Tests on Existing Permeable Pavement Surfaces

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    This study describes a field investigation that compares water infiltration rates of eight permeable parking lots located in Rimini City, Italy. In the experiment a single ring infiltrometer test was used to analyze the influence of the surface type, filling material, location in the parking stall, pavement age, and antecedent dry weather days on the infiltration capacity of the pavements. The results show that the permeability values are mostly affected by the position of the ring in the parking lot, filling material, and surface type rather than by the antecedent dry weather time and pavement age. The surface infiltration rate of the eight pavements ranges between a minimum of 123mm/h (site 6, permeable interlocking concrete paver, 2005) and a maximum of 20 137mm/h (site 4, concrete grid paver, 2005), exceeding the 97.2mm/h minimum design infiltration rate required by selected European authorities. The results also show that compaction decreases the infiltration rate. Therefore, the study could be useful in setting the standard test procedure to evaluate the performance of permeable pavements over time in the Mediterranean climate

    Fabrication strategies towards hydrogels for biomedical application: chemical and mechanical insights

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    This review aims at giving selected chemical and mechanical insights on design criteria that should be taken into account in hydrogel production for biomedical applications. Particular emphasis will be given to the chemical aspects involved in hydrogel design: macromer chemical composition, cross-linking strategies and chemistry towards “conventional” and smart/stimuliresponsive hydrogels. Mechanical properties of hydrogels in view of regenerative medicine applications will also be considered

    X-MAN: Explaining multiple sources of anomalies in video

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    Our objective is to detect anomalies in video while also automatically explaining the reason behind the detector's response. In a practical sense, explainability is crucial for this task as the required response to an anomaly depends on its nature and severity. However, most leading methods (based on deep neural networks) are not interpretable and hide the decision making process in uninterpretable feature representations. In an effort to tackle this problem we make the following contributions: (1) we show how to build interpretable feature representations suitable for detecting anomalies with state of the art performance, (2) we propose an interpretable probabilistic anomaly detector which can describe the reason behind it's response using high level concepts, (3) we are the first to directly consider object interactions for anomaly detection and (4) we propose a new task of explaining anomalies and release a large dataset for evaluating methods on this task. Our method competes well with the state of the art on public datasets while also providing anomaly explanation based on objects and their interactions

    Hashimoto ThYroiditis Coexistent with Papillary Thyroid Carcinoma

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    Several studies report a higher rate of papillary thyroid carcinomas (PTC) in patients with Hashimoto thyroiditis (HT), indicating a possible correlation between the two diseases. We studied a group of 89 subjects undergoing surgery for thyroid carcinomas compared with a control group of 89 subjects operated on for normofunctioning goiter, and a second group of 47 patients undergoing total thyroidectomy for HT. Association with HT was found in 19 of the 71 PTC subjects (26.7%) and in 8 goiter patients (8.9%), which was a significant difference (P < 0.02). Thirteen of the HT patients, mostly with the nodular form, showed coexistent PTC (27.6%). HT and PTC coexisted in several morphological, immunohistochemical, and biomolecular aspects; increased incidence of PTC in HT patients might therefore indicate that HT is a precursor of thyroid cancer. Further studies are required, however, in order to confirm this hypothesis; until then, HT patients should undergo careful clinical and technical follow-up

    A variation of Broyden Class methods using Householder adaptive transforms

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    In this work we introduce and study novel Quasi Newton minimization methods based on a Hessian approximation Broyden Class-\textit{type} updating scheme, where a suitable matrix B~k\tilde{B}_k is updated instead of the current Hessian approximation BkB_k. We identify conditions which imply the convergence of the algorithm and, if exact line search is chosen, its quadratic termination. By a remarkable connection between the projection operation and Krylov spaces, such conditions can be ensured using low complexity matrices B~k\tilde{B}_k obtained projecting BkB_k onto algebras of matrices diagonalized by products of two or three Householder matrices adaptively chosen step by step. Extended experimental tests show that the introduction of the adaptive criterion, which theoretically guarantees the convergence, considerably improves the robustness of the minimization schemes when compared with a non-adaptive choice; moreover, they show that the proposed methods could be particularly suitable to solve large scale problems where LL-BFGSBFGS performs poorly

    Combining single view recognition and multiple view stereo for architectural scenes

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    ©2001 IEEE. Personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution to servers or lists, or to reuse any copyrighted component of this work in other works must be obtained from the IEEE.This paper describes a structure from motion and recognition paradigm for generating 3D models from 2D sets of images. In particular we consider the domain of architectural photographs. A model based approach is adopted with the architectural model built from a “Lego kit” of parameterised parts. The approach taken is different from traditional stereo or shape from X approaches in that identification of the parameterised components (such as windows, doors, buttresses etc) from one image is combined with parallax information in order to generate the 3D model. This model based approach has two main benefits: first, it allows the inference of shape and texture where the evidence from the images is weak; and second, it recovers not only geometry and texture but also an interpretation of the model, which can be used for automatic enhancement techniques such as the application of reflective textures to windowsDick, A.R., Torr, P.H.S., Ruffle, S.J., Cipolla, R

    Metastatic seeding of colon adenocarcinoma manifesting as synchronous breast and chest wall localization: report of a case.

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    Colon carcinoma rarely metastasizes to the breast and it is usually associated with a poor prognosis. Even rarer is metastatic seeding of colon cancer cells in an intramammary location after surgery. Including a primary breast malignancy in the differential diagnosis of such cases is mandatory. We report a rare case of double seeding implantation of colon adenocarcinoma inside the breast parenchyma and intercostal muscles 6 years after resection of a pulmonary metastasis from colon adenocarcinoma. The metastasis was revealed by the presence of bone metaplasia in the intercostal muscles. We discuss how negative immunostaining for estrogen receptors, progesterone receptors, and HER-2, along with the immunohistochemical pattern of cytokeratin (CK) 20+/7-/5- and CDX2-positive immunostaining, excludes a primary breast malignancy, namely, a "matrix-producing" carcinoma, from the differential diagnosis. We also present the hypothesis of a paracrine pathogenetic mechanism to explain the bone metaplasia
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