Closing the performance gap between siamese networks for dissimilarity image classification and convolutional neural networks

In this paper, we examine two strategies for boosting the performance of ensembles of Siamese networks (SNNs) for image classification using two loss functions (Triplet and Binary Cross Entropy) and two methods for building the dissimilarity spaces (FULLY and DEEPER). With FULLY, the distance between a pattern and a prototype is calculated by comparing two images using the fully connected layer of the Siamese network. With DEEPER, each pattern is described using a deeper layer combined with dimensionality reduction. The basic design of the SNNs takes advantage of supervised k-means clustering for building the dissimilarity spaces that train a set of support vector machines, which are then combined by sum rule for a final decision. The robustness and versatility of this approach are demonstrated on several cross-domain image data sets, including a portrait data set, two bioimage and two animal vocalization data sets. Results show that the strategies employed in this work to increase the performance of dissimilarity image classification using SNN are closing the gap with standalone CNNs. Moreover, when our best system is combined with an ensemble of CNNs, the resulting performance is superior to an ensemble of CNNs, demonstrating that our new strategy is extracting additional information

Evoluzione geomorfologica della fascia costiera zona Foce Reno- Vene di Ancona/ Bellocchio (Parco del Delta del Po- RER) per gli intervalli 1814- 1999 (a) e 1954- 2020 (b)

Ricostruzioni evolutive del'area costiera circostante foce Reno ( litorale ferrarese- ravennate) e delle aree umide progressivamente formatesi ricostruibili sulla base di analisi ed elaborazione di dati cartografici ( sia pre- geodetica che moderna: intervallo 1814- 1978), telerilevati ( da foto aeree 1935- 2000 e foto da satellite ( 2000- 2005) e Lidar, abbinate con scenari previsionali di medio- termine (2020) definibili a partire da modelli numerici in grado di ricostruire e definire sia le caratteristiche della spiaggia emersa che sommersa

L\u2019Intrusione Salina negli Acquiferi Costieri Emiliano-Romagnoli

L\u2019assetto idrologico e idrogeologico della costa Emiliano-Romagnola \ue8 caratterizzato da bassissimi gradienti idraulici a causa della topografia soggiacente in pi\uf9 punti il livello marino e da forti gradienti di densit\ue0 dovuti a intrusione di acqua dal mare, dalle lagune, da fiumi e da canali aperti alle maree. In questo scenario, i problemi idrologici principali sono il difficile deflusso delle acque fluviali a mare e l\u2019intrusione d\u2019acqua salata nell\u2019acquifero freatico superficiale che \ue8 quasi completamente contaminato da acqua salata. Le possibilit\ue0 di intervento sono diverse ma limitate dall\u2019alta conduttivit\ue0 idraulica dell\u2019acquifero e dalla scarsa disponibilit\ue0 di acqua dolce. Possibili azioni di salvataggio includono la ricarica artificiale della falda, la ricostituzione dei cordoni di dune costiere, l\u2019ottimizzazione dei manufatti idraulici esistenti e lo sbarramento delle acque tidali marine lungo i corsi d\u2019acqua superficiali

Historical and recent evolution of the Reno river mouth and adjacent areas.

The Reno river mouth and the adjacent areas are characterized by sandy beaches, wide brackish lagoons and extended salt marshes. The study area belongs to the Po Delta Park of the Emilia Romagna Region. The study consists in a reconstruction of the coastal evolution from the beginning of the 19th century to the present. It is an analysis of the historical and geodetic cartography and of the photogrammetry. At the beginning of the XIX century the river mouth was oriented eastward but, after some human modifications to its terminal stretch, the river mouth showed a gradually northward shift, inducing the growth of a spit; in the last century the spit entered in an erosive phase, which caused the reduction and the thinning of its shape. At the same time the northward movement of the sediment coming from the Reno river caused the occlusion of the outlet of the Bellocchio Channel inducing a decrease of water exchange between the \u201cSacca di Bellocchio\u201d and the Adriatic sea. From a naturalistic point of view, the \u201cSacca di Bellocchio\u201d is one of the most important area of the Po Delta Park; the worrying forecasts for the next decades give uncertain expectation for this esteemed, sensitive ecosystem. The territorial setting suggests the possibility of increased intensification of flooding events, the amplifications of beach erosion, an instability in the water circulation and an enhanced intrusion of the saline wedge into the channels and into the coastal aquifers. Even in a short-term scale, all the above factors will be able to significantly modify this ecosystem

STUDIO 3D DELL’INTRUSIONE SALINA NELLE DUNE A NORD DI RAVENNA: MONITORAGGIO E MODELLIZAZIONE USANDO DATI LIDAR E SEAWAT

Nel lavoro si presenta un modello numerico 3D dell’intrusione salina di un tratto di litorale a nord-est di Marina Romea, Emilia-Romagna, Italia. Per il modello è stata utilizzata la topografia in tre dimensioni, basata su dati LIDAR, per verificare se lo sbancamento delle dune, a seguito della costruzione dei stabilimenti balneari, abbia incrementato l’intrusione salina nell’acquifero freatico. I risultati numerici sono raffrontati con i dati del monitoraggio dei livelli piezometrici e della conducibilità condotto su otto piezometri per un periodo di dodici mesi

Experiments of image classification using dissimilarity spaces built with siamese networks

Traditionally, classifiers are trained to predict patterns within a feature space. The image classification system presented here trains classifiers to predict patterns within a vector space by combining the dissimilarity spaces generated by a large set of Siamese Neural Networks (SNNs). A set of centroids from the patterns in the training data sets is calculated with supervised k-means clustering. The centroids are used to generate the dissimilarity space via the Siamese networks. The vector space descriptors are extracted by projecting patterns onto the similarity spaces, and SVMs classify an image by its dissimilarity vector. The versatility of the proposed approach in image classification is demonstrated by evaluating the system on different types of images across two domains: two medical data sets and two animal audio data sets with vocalizations represented as images (spectrograms). Results show that the proposed system's performance competes competitively against the best-performing methods in the literature, obtaining state-of-the-art performance on one of the medical data sets, and does so without ad-hoc optimization of the clustering methods on the tested data sets

Climate and water budget change of a Mediterranean coastal watershed, Ravenna, Italy

It is generally difficult to quantify exactly the freshwater going in or out of the coastal watersheds along the northern Adriatic Sea because, on one hand, excess water is drained and pumped into the sea to prevent flooding but, on the other hand, water is brought onto the land from far away for irrigation. Fragmentation of water authorities makes it difficult to collect all the necessary information. Climate change and increasing salinization of the coastal aquifers make it imperative, however, to better know the quantities of freshwater involved in these small basins. The water budget of a small coastal agricultural watershed along the Adriatic Sea in Italy (The Quinto Basin near Ravenna) is presented here considering different land uses. The evaporation of open water and the evapotranspiration of wetlands, pine forests, bare soil and irrigated agriculture are calculated based on the Penman\u2013Monteith equation and the Cropwat program. The current water budget is based on average climate data from 1989 to 2008 and drainage and irrigation data. Predictions for future evapotranspiration, net irrigation and hydrologic deficit are calculated with climate data from IPCC (The Fourth Assessment Report (AR4) 200, Climate change 2007). From the study results, the soil type may determine whether or not a crop will need more or less irrigation in the future. Regulations on land use should therefore consider which crop type can be grown on a specific soil type. Water budget analysis in scenarios A1b and A2 both show an increase of water deficits in the summer and an increase of water surplus in the winter. This is explained by the fact that a larger percentage of the rain will fall in winter and not during the growth season. The open water evaporation will decrease under future climate scenarios as a result of increased relative humidity in winter and decreased wind velocity. This may have a positive effect on the water cycle. The current irrigation is very abundant, but has beneficial effects in contrasting soil salinization and saltwater intrusion into the coastal aquifer

Coastal dunes as a resilient factor: a new challenge for coastal system management: exemple from Bevano River (Ravenna, Italy).

Coastal dunes are natural accumulations of sand formed by winds. Their occurrence, size and shape mainly depend on: winds strength and direction, grain size, beach amplitude and vegetation cover. Another factor that has a very strong (and negative) impact on coastal dunes is Human exploitation of the coast. Past policies of coastal bad management have brought about a very damaged system, where dunes are often stressed or even absent. This work aims at describing the function of dunes along an exploited tract of coast where dunes act as a natural defence against storms, erosion and wave attack; but they also have a very important role in defending landward areas against saltwater intrusion. The Province of Ravenna is particularly affected by subsidence that causes lowering of already depressed areas and worsens the saltwater intrusion phenomenon. Along this coast, dunes are the only elements that lay above the ground. Moreover, dunes have a great infiltration capacity (Tsoar, 2005) and they can accumulate fresh groundwater, the water table, standing above sea level, that acts as a hydrostatic control on saltwater intrusion, by contrasting the seawater density head. We evaluated the influence of dunes in minimizing saltwater intrusion by comparing different data obtained from groundwater table height and salinity

The role of dunes in coastal hydrology and integrated coastal zone management.

Dune characterization in coastal zones is important for planning coastal defenses, groundwater management, and tourism development. Dune protection should be one of the main goals of any Integrated Coastal Zone Management Plan (ICZM). Coastal dunes efficiently oppose saltwater intrusion: their topographic elevation and their excellent infiltration capacity provide freshwater recharge and a hydraulic head that protect from saline intrusion according to the Ghyben-Herzberg principle (Fetter, 2001). The lateral continuity of the dunes system is also important for creating a continuous freshwater lens along the coast. As part of the Interreg IIIc Beachmed – “PosiDune project”, a monitoring campaign for groundwater levels and quality is being conducted on some test sites along stretches of the Ravenna coast: P.to Corsini, Marina Romea, Marina di Ravenna, Bevano river mouth. Dunes are still preserved in these areas and they act as natural defenses against storms, erosion and wave attack (Caruso et al., 2004; Caruso et al. 2006). A monitoring network has been established in each test site by placing piezometers both on the back and the crest of the dune and by carrying out a VES (Vertical Electri Sounding) geophysical campaign. The two methods (giving the chance to compare direct – piezometers - and indirect – geoelectric - data) has allowed to characterize the thickness of the fresh groundwater lens and the depth of the freshwater-saltwater interface. These actions have been integrated using: 1. a G.I.S. for data management; 2. a topographic and bathymetric reconstruction of the area using a LIDAR (Light detection and Ranging) survey; 3. a systematic seasonal update of the topography base and geomorphology using DGPS and theodolite surveys; 4. a survey of the geomorphologic evolution of the area through the periodical (monthly) acquisition of aerial images (flight height at 300m). The techniques employed are aimed at a precise charactetrization of the morphologic and hydrogeologic framework of the study areas. In addition, the maintenance of the monitoring system in future years will allow a better understanding of the effects of vegetation, dune restoration, and climate change to coastal hydrology and to ecosystem development (Gabbianelli & Sangiorgi, 2004; Ranjan et al. 2006). A clear comprehension of the role of dunes, achieved with this project, will be helpful for the management of the sites studied, especially considering their naturalistic values and peculiarities (they all belong to the Ramsar Zones list, SIC/ZPS sites list, Regional Po Delta Park – Emilia Romagna Region areas)