Search results for "Bma"
showing 10 items of 241 documents
Preliminary data concerning the morphology of a Calabrian Ionian margin area: Caulonia and Marina di Gioiosa canyons
2008
In the framework of the Vector National Italian Project (VulCost line), aimed to study the role of the morphology and the geology of the Ionian Calabrian margin in the coastline evolution, an oceanographic cruise was planned to collect geophysical data along two canyon systems: Caulonia and Marina di Gioiosa. The survey explored the continental shelf and slope from a depth of 15 m to more than 1150 m, using Multibeam Echosounder to investigate the seafloor topography. This work provides an outline of the erosive feature of the slope, shaped mostly by seasonal river input and by the connection to the structural and geological characteristics of the margin, made interesting by a narrow shelf …
Submarine Mass Movements Along a Sediment Starved Margin: The Menorca Channel (Balearic Islands - Western Mediterranean)
2014
6th International Symposium on Submarine Mass Movements and Their Consequences (ISSMMTC), 23-25 September 2013, Kiel, Germany.-- 10 pages, 5 figures
Submarine canyons of north-western Sicily (Southern Tyrrhenian Sea): Variability in morphology, sedimentary processes and evolution on a tectonically…
2014
Special issue Submarine Canyons: Complex Deep-Sea Environments Unravelled by Multidisciplinary Research.-- 13 pages, 11 figures, 2 tables
Potential Cyclic Steps in a Gully System of the Gulf of Palermo (Southern Tyrrhenian Sea)
2016
Multibeam bathymetric data revealed the occurrence of atrain of bedforms along a gully system in the Gulf of Palermo, Southern Tyrrhenian Sea. The observed gullies, located in the westernmost sector of the Gulf of Palermo, incise the outer shelf at a depth of 120 m and converge at the Zafferano Canyon, connecting to the Palermo Basin at a the depth of 1300 m. Bedforms develop along these gullies and along the thalweg of the canyon, displaying an average wavelength of 200 m, with maximum values of 340 m. Their gully floor location combined with their wave length, upslope asymmetry and crescent shape point to a possible cyclic steporigin of these bedforms. Preliminary numerical modeling sugge…
Long-term zoobenthos variability in the Gulf of Riga in relation to climate variability
2001
Abstract Macrozoobenthos data were collected three times a year from 1979 to 1996 in the Gulf of Riga, Eastern Baltic Sea. Interannual variability of the abundance and biomass of benthic fauna at coastal and offshore areas was related to climate variability using a multivariate regression model. The results suggest that the interannual variability of macrozoobenthos biomass at the offshore station in spring is controlled by the climate variability during winter-time. No correlations to large-scale climate pattern have been detected for other seasons and for the coastal region. An analysis of river runoff, nitrogen, and phosphorus data of the River Daugava indicates that the anthropogenic in…
A low power and high resolution data logger for submarine seismic monitoring
2010
The design, implementation and characterization of a digital waveform recorder for ocean bottom seismic monitoring is here reported. The system is capable of synchronously acquiring, and logging on a flash memory bank, four high resolution signals. Thanks to a very careful design of the system architecture and by using robust digital signal processing techniques, two main conflicting issues have been addressed: a high dynamic range, better than 120 dB, usually obtained with high energy demanding converters, and a power consumption as low as 250 mW, hence allowing to easily increase the time of a continuous submarine monitoring session up to 3 months.
A Damage Identification Approach for Offshore Jacket Platforms Using Partial Modal Results and Artificial Neural Networks
2018
This paper presents a damage identification method for offshore jacket platforms using partially measured modal results and based on artificial intelligence neural networks. Damage identification indices are first proposed combining information of six modal results and natural frequencies. Then, finite element models are established, and damages in structural members are assumed by reducing the structural elastic modulus. From the finite element analysis for a training sample, both the damage identification indices and the damages are obtained, and neural networks are trained. These trained networks are further tested and used for damage prediction of structural members. The calculation res…
Design optimization of mooring system: An application to a vessel-shaped offshore fish farm
2019
Abstract Design optimization of mooring systems of offshore floating structures is a challenging task, partly because of the large number of design variables, complicated design constraints, nonlinear system behavior, and time-consuming numerical simulations. For engineering designs, efficient yet accurate approaches are needed. This paper proposes an integrated optimization methodology for design of mooring systems. The methodology integrates the design of experiments, screening analysis, time-domain simulations, and a metamodel-based optimization procedure. To demonstrate the methodology, the mooring system of a vessel-shaped offshore fish farm was designed considering the ultimate limit …
Interobserver and intraobserver variability in the radiological assessment of sialolithiasis using cone beam computed tomography
2021
Background Data regarding the inter- and intraobserver variability in the radiological assessment of sialolithiasis using cone beam computed tomography are missing in the current literature. This study assessed the inter- and intraobserver variability in the radiological assessment of sialolithiasis using cone beam computed tomography (CBCT). Material and Methods In 107 patients, 130 salivary glands (65 parotid and 65 submandibular) with clinical signs of obstruction were assessed by four independent observers; 2 residents OMFS and 2 experienced OMFS. The observers analyzed the CBCT images and determined the absence or presence of one or more salivary stones in the affected gland. This proc…
Topology guaranteeing manifold reconstruction using distance function to noisy data
2006
Given a smooth compact codimension one submanifold S of Rk and a compact approximation K of S, we prove that it is possible to reconstruct S and to approximate the medial axis of S with topological guarantees using unions of balls centered on K. We consider two notions of noisy-approximation that generalize sampling conditions introduced by Amenta & al. and Dey & al. Our results are based upon critical point theory for distance functions. For the two approximation conditions, we prove that the connected components of the boundary of unions of balls centered on K are isotopic to S. Our results allow to consider balls of different radii. For the first approximation condition, we also prove th…