3,122 research outputs found
Earthquake forecasting: a possible solution considering the GPS ionospheric delay
Abstract. The recent earthquakes in L'Aquila (Italy) and in Japan have dramatically emphasized the problem of natural disasters and their correct forecasting. One of the aims of the research community is to find a possible and reliable forecasting method, considering all the available technologies and tools. Starting from the recently developed research concerning this topic and considering that the number of GPS reference stations around the world is continuously increasing, this study is an attempt to investigate whether it is possible to use GPS data in order to enhance earthquake forecasting. In some cases, ionospheric activity level increases just before to an earthquake event and shows a different behaviour 5–10 days before the event, when the seismic event has a magnitude greater than 4–4.5 degrees. Considering the GPS data from the reference stations located around the L'Aquila area (Italy), an analysis of the daily variations of the ionospheric signal delay has been carried out in order to evaluate a possible correlation between seismic events and unexpected variations of ionospheric activities. Many different scenarios have been tested, in particular considering the elevation angles, the visibility lengths and the time of day (morning, afternoon or night) of the satellites. In this paper, the contribution of the ionospheric impact has been shown: a realistic correlation between ionospheric delay and earthquake can be seen about one week before the seismic event
Oil Spill Detection Analyzing “Sentinel 2“ Satellite Images: A Persian Gulf Case Study
Oil spills near exploitation areas and oil loading ports are often related to the ambitions of governments to get more oil market share and the negligence at the time of the loading in large tankers or ships. The present study investigates one oil spill event using multi sensor satellite images in the Al Khafji (between Kuwait and Saudi Arabia) zone. Oil slicks have been characterized with multi sensor satellite images over the Persian Gulf and then analyzed in order to detect and classify oil spills in this zone. In particular this paper discusses oil pollution detection in the Persian Gulf by using multi sensor satellite images data. Oil spill images have been selected by using Sentinel 2 images pinpointing oil spill zones.
ENVI software for analysing satellite images and ADIOS (Automated Data Inquiry for Oil Spills) for oil weathering modelling have been used.
The obtained results in Al Khafji zone show that the oil spill moves towards the coastline firstly increasing its surface and then
decreasing it until reaching the coastline
A Narrative Literature Review on the Role of Exercise Training in Managing Type 1 and Type 2 Diabetes Mellitus
Diabetes mellitus (DM) is a metabolic disease characterized by chronic hyperglycemia associated with impaired carbohydrate, lipid, and protein metabolism, with concomitant absence of insulin secretion or reduced sensitivity to its metabolic effects. Patients with diabetes mellitus have a 30% more risk of developing heart failure and cardiovascular disease compared to healthy people. Heart and cardiovascular problems are the first cause of death worldwide and the main complications which lead to high healthcare costs. Such complications can be delayed or avoided by taking prescribed medications in conjunction with a healthy lifestyle (i.e., diet and physical activity). The American College of Sports Medicine and the American Diabetes Association recommend that diabetic people reduce total sedentary time by incorporating physical activity into their weekly routine. This narrative literature review aims to summarize and present the main guidelines, pre-exercise cardiovascular screening recommendations, and considerations for patients with diabetes and comorbidities who are planning to participate in physical activity programs
Applying acceptance requirements to requirements modeling tools via gamification: a case study on privacy and security.
Requirements elicitation, analysis and modeling are critical activities for software success. However, software systems are increasingly complex, harder to develop due to an ever-growing number of requirements from numerous and heterogeneous stakeholders, concerning dozens of requirements types, from functional to qualitative, including adaptation, security and privacy, ethical, acceptance and more. In such settings, requirements engineers need support concerning such increasingly complex activities, and Requirements Engineering (RE) modeling tools have been developed for this. However, such tools, although effective, are complex, time-consuming and requiring steep learning curves. The consequent lack of acceptance and abandonment in using such tools, by engineers, paves the way to the application of RE techniques in a more error-prone, low-quality way, increasing the possibility to have failures in software systems delivered. In this paper, we identify main areas of lack of acceptance, affecting RE engineers, for such tools, and propose an approach for making modeling tools more effective in engaging the engineer in performing RE in a tool-based way, receiving adequate feedback and staying motivated to use modeling tools. This is accomplished by performing acceptance requirements analysis (through the Agon Framework) and using gamification to increase the engagement of engineers during the usage of RE modeling tools. Towards this end, we performed a case study, within the VisiOn European Project, for enhancing a tool for modeling privacy and security requirements. Our case study provides preliminary evidence that our approach supports in making RE modeling tools more engaging from the engineer perspective
Il gioco della logica tra uso del linguaggio e costruzione della scienza.
E tanto più intendo tanto più ignoro, motto di Tommaso Campanella, può servire a spiegare, bene, le virgolette messe attorno alla parola: gioco, ed il suo carattere, ambiguo e contraddittorio, essendo tutto ciò vero tanto nello uso del linguaggio, quanto nella costruzione della scienza. Quanto segue si dipana in alcuni meandri della filosofia analitica, a partire dal positivismo logico, dove molto forte è l’accanirsi contro la metafisica. A riguardo, avendo presente l’uso rinnovato del termine, fatto da giovani filosofi contemporanei, corre il dovere di precisare la sua validità , se significa andare oltre le cose fisiche, con le assunzioni necessarie per pensare e fare scienza. Al contrario, validissimo è il rigetto della metafisica, quando questa voglia dire, come nella tradizione della storia del pensiero, rifarsi a principi primi indiscutibili ed assoluti. Rudolf Carnap e Karl Raimund Popper sono i maggiori esponenti delle scuole filosofiche, prese in esame. La trattazione collega linguaggio e costruzione della scienza, perché una concezione moderna descrive la scienza come un linguaggio, capace di leggere la realtà fisica, dove la complessità della analisi cresce al crescere della complessità della modellazione adottata. Infatti oltre a muoversi liberamente nello spazio, parametrizzato con righe, colonne e pile, è spesso necessario muoversi congiuntamente nel tempo e/o nel cosiddetto spazio delle scale, entrambi parametrizzati con pioli e montanti, a seconda che si permanga ad un dato livello, oppure si passi da un livello ad un altro. Da altra parte, un esempio musicale dà il segno della complessità : le cinque note pentatoniche (la si do re mi fa sol) permettono 720 permutazioni, mentre le dodici note (mettendo insieme i tasti bianchi e neri del pianoforte) permettono 479.001.600 permutazioni e, anche limitandosi alle ventiquattro scale armoniche, maggiori e minori (sulle sette note del clavicembalo ben temperato), il numero di permutazioni è 120.960. In questo contesto, il superamento della empiria fa passare dalla capacità di verificazione alla sola possibilità di falsificazione, dove è possibile dire quello che è errato, ma non è possibile certificare quello che è esatto. Infatti la verità è sempre provvisoria e precaria, valida fino ad una possibile smentita, più o meno prossima, e le costruzioni tecniche, sociali, economiche e politiche sono, sempre e solo, governate dal dubbio ed altrettanto precarie e provvisorie. Infine con un salto notevole di contenuto, ma affatto estraneo alla vita ed alle concezioni dei pensatori (qui già citati e/o citati nel seguito), è davvero difficile, soprattutto in questi tempi così tanto travagliati, separare il parlare alto di ricerca scientifica e tecnologica, nonché di storia della scienza e della tecnica, e di epistemologia, dai casi della vita quotidiana, vari e diversi. Di fronte a tutti questi è davvero difficile scegliere la strada migliore, in ogni caso, ben sapendo come occorra, sempre ed ovunque, il coraggio e lo impegno e talvolta anche la ribellione
Smartphone-based photogrammetry for the 3D modeling of a geomorphological structure
The geomatic survey in the speleological field is one of the main activities that allows for the adding of both a scientific and popular value to cave exploration, and it is of fundamental importance for a detailed knowledge of the hypogean cavity. Today, the available instruments, such as laser scanners and metric cameras, allow us to quickly acquire data and obtain accurate three-dimensional models, but they are still expensive, require a careful planning phase of the survey, as well as some operator experience for their management. This work analyzes the performance of a smartphone device for a close-range photogrammetry approach for the extraction of accurate three-dimensional information of an underground cave. The image datasets that were acquired with a high-end smartphone were processed using the Structure from Motion (SfM)-based approach for dense point cloud generation: different image-matching algorithms implemented in a commercial and an open source software and in a smartphone application were tested. In order to assess the reachable accuracy of the proposed procedure, the achieved results were compared with a reference dense point cloud obtained with a professional camera or a terrestrial laser scanner. The approach has shown a good performance in terms of geometrical accuracies, computational time and applicability
CHARACTERIZATION OF A MOBILE MAPPING SYSTEM FOR SEAMLESS NAVIGATION
Abstract. Mobile Mapping Systems (MMS) are multi-sensor technologies based on SLAM procedure, which provides accurate 3D measurement and mapping of the environment as also trajectory estimation for autonomous navigation. The major limits of these algorithms are the navigation and mapping inconsistence over the time and the georeferencing of the products. These issues are particularly relevant for pose estimation regardless the environment like in seamless navigation. This paper is a preliminary analysis on a proposed multi-sensor platform integrated for indoor/outdoor seamless positioning system. In particular the work is devoted to analyze the performances of the MMS in term of positioning accuracy and to evaluate its improvement with the integration of GNSS and UWB technology. The results show that, if the GNSS and UWB signal are not degraded, using the correct weight to their observations in the Stencil estimation algorithm, is possible to obtain an improvement in the accuracy of the MMS navigation solution as also in the global consistency of the final point cloud. This improvement is measured in about 7 cm for planimetric coordinate and 34 cm along the elevation with respect to the use of the Stencil system alone
Vulnerability assessment of concrete bridges using different methods of visual inspection
This paper shows the comparisons between different methods of visual inspection used in European Countries. These methodologies are applied to the deck bridge located near Cagliari, along the SS 195 road to Capoterra. From a strategic point of view, this structure plays a key role ensuring a direct connection to different structures related to industrial and local productions and to an important touristic district. This is a prestressed concrete bridge in an aggressive marine environment, which in October 2008 was hit by a flood that caused subsidence in the foundations. The aim of our inspection is to obtain a real measure of the vulnerability through different procedures and to determine which is the best method able to give objective results
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