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International Journal of digital Earth 2023年第1期16卷 3810-3837页

作者： Nicola Montaldo Andrea Gaspa Roberto Corona dipartimento di Ingegneria civile ambientale e architetturaUniversita di CagliariCagliariItaly

Periodic observations of vegetation index,such as the normalized difference vegetation index(NDVI),can be used for data assimilation in heterogenous ***,the new Sentinel 2 Multispectral instrument and Landsat 8 Operational Land Imager sensor data are available at such high temporal and spatial resolutions that can be used to detect the patches of the main vegetation components(grass and trees)of heterogenous ecosystems,and capture their *** demonstrate the possibility to merge grass and tree NDVI observations and models,to optimally provide robust predictions of grass and tree leaf area *** proposed assimilation approach assimilates NDVI data through the Ensemble Kalman filter(EnKF)and dynamically calibrates a key vegetation dynamic model parameter,the maintenance respiration coeffcient(ma).In the presence of large bias of the grass and tree ma base values,only the use of the proposed assimilation approach removes the large bias in the biomass balance,dynamically calibrating maintenance respiration coefficients,and corrects the *** performance of a land surface-vegetation model was improved by assimilating observations of *** effective impact of the proposed assimilation approach on the evapotranspiration and CO_(2) uptake predictions in the heterogenous ecosystem is also demonstrated.

关键词： Data assimilation leaf area index heterogenous ecosystem vegetation dynamic model Landsat 8 Sentinel 2

Updating the orbital ephemeris of the dipping source XB 1254–690 and the distance to the source

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Research in Astronomy and Astrophysics 2017年第10期17卷 97-108页

作者： Angelo F.Gambino Rosario Iaria Tiziana di Salvo Marco Matranga Luciano Burderi Fabio Pintore Alessandro Riggio Andrea Sanna universita degli Studi di Palermo Dipartimento di Fisica e Chimica universita degli Studi di cagliari Dipartimento di Fisica INAF-Istituto di Astrofisica Spaziale e Fisica Cosmica - Milano

XB 1254-690 is a dipping low mass X-ray binary system hosting a neutron star and showing type I X-ray bursts. We aim at obtaining a more accurate orbital ephemeris and at constraining the orbital period derivative of the system for the first time. In addition, we want to better constrain the distance to the source in order to locate the system in a well defined evolutive scenario. We apply, for the first time, an orbital timing technique to XB 1254-690, using the arrival times of the dips present in the light curves that have been collected during 26 yr of X-ray pointed observations acquired from different space missions. We estimate the dip arrival times using a statistical method that weights the count-rate inside the dip with respect to the level of persistent emission outside the dip. We fit the obtained delays as a function of the orbital cycles both with a linear and a quadratic function. We infer the orbital ephemeris of XB 1254-690, improving the accuracy of the orbital period with respect to previous estimates. We infer a mass of M2 = 0.42 ± 0.04 M for the donor star, in agreement with estimations already present in literature, assuming that the star is in thermal equilibrium while it transfers part of its mass via the inner Lagrangian point, and assuming a neutron star mass of 1.4 Mo. Using these assumptions, we also constrain the distance to the source, finding a value of 7.6±0.8 kpc. Finally, we discuss the evolution of the system, suggesting that it is compatible with a conservative mass transfer driven by magnetic braking.

关键词： stars: neutron -- stars: individual (XB 1254-690) -- X-rays: binaries -- X-rays: stars --Astrometry and celestial mechanics: ephemerides

A Weierstrass Representation Formula for Minimal Surfaces in H_3 and H^2×R

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Acta Mathematica Sinica,English Series 2006年第6期22卷 1603-1612页

作者： Francesco MERCURI StefanoMONTALDO PaolaPIU Departamento de Matematica.C.P.6065 IMECCUNICAMP UniversitàdegliStudi di cagliari Dipartimento di Matematica

We give a general setting for constructing a Weierstrass representation formula for simply connected minimal surfaces in a Riemannian manifold. Then, we construct examples of minimal surfaces in the three dimensional ... 详细信息

关键词： Minimal immersions Weierstrass representation Heisenberg group Hyperbolic space

Rehabilitation of Abandoned Monumental Hospitals： Tools for Urban Liveability

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Journal of Civil Engineering and Architecture 2016年第6期10卷 643-650页

作者： Pier Francesco Cherchi dipartimento di Ingegneria Civile Ambientale e Architettura Universita degli Studi di Cagliari Cagliari 09123 Italy

This proposal is intended to be a contribution toward achieving more liveable cities through the revitalization of inner areas based on the restoration and rehabilitation of historic facilities in order to meet current needs. The research starts by posing the following questions. Can we claim, in a general perspective of improvement of the quality of life in towns and cities, that the recovery of abandoned historic buildings could be a key-factor in conservation and innovation policies of the historical heart of towns？ What relationship, if any, is there between the adaptive-reuse design of ancient hospitals and the effects of such action, not only in terms of heritage conservation but also in terms of economic and social regeneration of the surrounding context？ The complexity of this issue is addressed by analyzing related cases, relevant for their design solutions and effects, and proposes answers to the opening questions by correlating the main characters of relevant case studies in Europe.

关键词： Adaptive reuse sustainable preservation sustainable preservation historic hospitals recycling.

On the Boundary Behaviour,Including Second Order Effects,of Solutions to Singular Elliptic Problems

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Acta Mathematica Sinica,English Series 2007年第3期23卷 479-486页

作者： S.BERHANU F.CUCCU G.PORRU Department of Mathematics Temple UniversityPhiladelphiaPA 19122USA dipartimento di Matematica e Informatica University of Cagliarivia Ospedale 72 09124 CagliariItaly

For γ≥1 we consider the solution u=u（x） of the dirichlet boundary value problem Δu ＋ u^-γ=0 in Ω, u=0 on δΩ. For γ= 1 we find the estimate u（x）=p（δ（x））[1＋A（x）（log 1/δ（x）^-6],where p（r） ≈ r r√2 log（1/r） near r = 0,δ（x） denotes the distance from x to δΩ, 0 〈ε 〈 1/2, and A（x） is a bounded function. For 1 〈 γ 〈 3 we findu（x）=（γ＋1/√2（γ-1）δ（x））^2/γ＋[1＋A（x）（δ（x））2γ-1/γ＋1]For γ3= we prove thatu（x）=（2δ（x））^1/2[1＋A（x）δ（x）log 1/δ（x）]

关键词： elliptic problems singular equations boundary behaviour

Deep panoramic depth prediction and completion for indoor scenes

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Computational Visual Media 2024年第5期10卷 903-922页

作者： Giovanni Pintore Eva Almansa Armando Sanchez Giorgio Vassena Enrico Gobbetti Visual and Data-intensive Computing CRS4Cagliari 09134Italy Gexcel srl Elmas(CA)09097Italy Department of Civil EnvironmentArchitectural Engineeringand Mathematics(DICATAM)Universita degli Studi di Brescia(UNIBS)Brescia(BS)25123Italy.

We introduce a novel end-to-end deeplearning solution for rapidly estimating a dense spherical depth map of an indoor *** input is a single equirectangular image registered with a sparse depth map,as provided by a variety of common capture *** is inferred by an efficient and lightweight single-branch network,which employs a dynamic gating system to process together dense visual data and sparse geometric *** exploit the characteristics of typical man-made environments to efficiently compress multiresolution features and find short-and long-range relations among scene ***,we introduce a new augmentation strategy to make the model robust to different types of sparsity,including those generated by various structured light sensors and LiDAR *** experimental results demonstrate that our method provides interactive performance and outperforms stateof-the-art solutions in computational efficiency,adaptivity to variable depth sparsity patterns,and prediction accuracy for challenging indoor data,even when trained solely on synthetic data without any fine tuning.

关键词： machine learning image processing and computervision visionand scene understanding 3D stereo scene analysis

Complete pancreatic heterotopia of gallbladder with hypertrophic duct simulating an adenomyoma

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World Journal of Gastroenterology 2006年第11期12卷 1786-1787页

作者： Luca Pilloni Alessandro Cois Alessandro Uccheddu Rossano Ambu Pierpaolo Coni Gavino Faa Istituto di Anatomia Patologica dipartimento di Citomorfologia Universita degli Studi di CagliariItaly Semeiotica Chirurgica dipartimento Chirurgico Materno Infantile e di Scienze delle Immagini Università degli Studi di CagliariItaly Istituto di Anatomia Patologica dipartimento di Citomorfologia Università degli Studi di CagliariItaly

The gallbladder is an unusual location of pancreatic heterotopia, defined as the presence of pancreatic tissue lacking anatomical and vascular continuity with the main body of the gland. A 28-year-old man presented with anorexia, nausea and pain in the right upper abdomen. On physical examination, the abdomen was tender to palpation and Murphy sign was positive. The patient underwent a cholecystecomy. This case, in our opinion, is very interesting since it permits to consider a controversial issue in the pathology of the gallbladder. The histological appearance of ductal structure in pancreatic heterotopia resembles the histological picture of both Aschoff-Rokitansky （AR） sinuses and adenomyomas. This finding suggests that these lesions are linked by a common histogenetic origin. We suggest that the finding of an adenomyoma in the gallbladder should prompt an extensive sampling of the organ in order to verify the coexistence of pancreatic rests.

关键词： Pancreatic heterotopia Gallbladder Hypertrophic duct Adenomyoma Aschoff-Rokitansky sinuses

Ligninolytic Peroxidase-Like Activity of a Synthetic Metalloporphine Immobilized onto Mercapto-Grafted Crosslinked PVA Inspired by the Active Site of Cytochrome P450

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催化学报 2011年第11期32卷 1663-1666页

作者： Paolo ZUCCA Antonio RESCIGNO Enrico SANJUST dipartimento di Scienze e Tecnologie Biomediche Università di Cagliari Monserrato 09042 Italy Consorzio per lo Sviluppo dei Sistemi a Grande Interfase Sesto Fiorentino 50019 Italy

A synthetic metalloporphine was immobilized onto a PVA-based and mercapto-grafted solid support, emulating the active site of cytochrome P450. Its ligninolytic peroxidase-like catalytic activity was studied. The coordinated mercapto ligand significantly affected the catalytic features of the catalyst because the oxidation of lignin-model compounds was very slow by comparison with imidazoleand pyridine-coordinated immobilized metalloporphines. Conversely, the catalyst efficiently bleached several industrial dyes and thus demonstrated promising activity for this application. Based on this altered substrate specificity the oxygen-donor catalytic route seems to be more favorable than a single electron oxidation pathway.

关键词： porphine porphyrin lignin peroxidase cytochrome P450 biomimetic

Road-Spine versus Road-Tube： Roads as Space Generators

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Journal of Civil Engineering and Architecture 2016年第8期10卷 901-911页

作者： Alfonso Annunziata diCAAR (dipartimento di Ingegneria Civile Ambientaleed Architettura) Universita degli Studidi Cagliari Cagliari 1-09123 Italy

Arteries devoted to sustain streams of users, resources and debris, are a foremost factor and pre-condition of the development of urban areas and of the transformation of landscapes. Roadscapes reflect outcomes related to super urbanization tendencies. Often conceived as isolated tubes, roads cut and obscure form, structure, biotic and abiotic factors of sites, urban fabrics and spaces. A broad vision of landscape is a basis for reconceiving roads. The concept of road-spine emerges： the road is conceived as the basis of a bundle of routes, nodes, surfaces, poles and tiles, devised to frame and shape a mosaic of open spaces, crops, farms, stores, basins and service areas. The road-spine entails the idea of a permeable infrastructure devised to integrate diverse functions： from serving various forms of motion, by ordering an isotropic grid of routes, to framing a porous urbanscape; from disposing surfaces meant to preserve biocenosis and biotopes, to favoring osmosis amid land uses. It also prefigures a distribution of land uses dependent on site vocations, and a mosaic of scenarios open to encounter, evasion, rest, amusement, participation, and to spontaneous practices of space.

关键词： Infrastructure landscape open space edge road.

Deep Learning and Time Series-to-Image Encoding for Financial Forecasting

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IEEE/CAA Journal of Automatica Sinica 2020年第3期7卷 683-692页

作者： Silvio Barra Salvatore Mario Carta Andrea Corriga Alessandro Sebastian Podda diego Reforgiato Recupero Department of Mathematics and Computer Science University of CagliariCagliari 09121Italy

In the last decade,market financial forecasting has attracted high interests amongst the researchers in pattern ***,the data used for analysing the market,and then gamble on its future trend,are provided as time series;this aspect,along with the high fluctuation of this kind of data,cuts out the use of very efficient classification tools,very popular in the state of the art,like the well known convolutional neural networks(CNNs)models such as Inception,Res Net,Alex Net,and so *** forces the researchers to train new tools from *** operations could be very time *** paper exploits an ensemble of CNNs,trained over Gramian angular fields(GAF)images,generated from time series related to the Standard&Poor's 500 index future;the aim is the prediction of the future trend of the ***.A multi-resolution imaging approach is used to feed each CNN,enabling the analysis of different time intervals for a single observation.A simple trading system based on the ensemble forecaster is used to evaluate the quality of the proposed *** method outperforms the buyand-hold(B&H)strategy in a time frame where the latter provides excellent *** quantitative and qualitative results are provided.

关键词： Convolutional neural networks(CNNs) ensemble of CNNs financial forecasting Gramian angular fields(GAF)imaging