INTEROPERABILITY FOR MODELING AND SIMULATION IN MARITIME EXTENDED FRAMEWORK

This thesis reports on the most relevant researches performed during the years of the Ph.D. at the Genova University and within the Simulation Team. The researches have been performed according to M&S well known recognized standards. The studies performed on interoperable simulation cover all the environments of the Extended Maritime Framework, namely Sea Surface, Underwater, Air, Coast & Land, Space and Cyber Space. The applications cover both the civil and defence domain. The aim is to demonstrate the potential of M&S applications for the Extended Maritime Framework, applied to innovative unmanned vehicles as well as to traditional assets, human personnel included. A variety of techniques and methodology have been fruitfully applied in the researches, ranging from interoperable simulation, discrete event simulation, stochastic simulation, artificial intelligence, decision support system and even human behaviour modelling

Natural experiments: An overview of methods, approaches, and contributions to public health intervention research

Population health interventions are essential to reduce health inequalities and tackle other public health priorities, but they are not always amenable to experimental manipulation. Natural experiment (NE) approaches are attracting growing interest as a way of providing evidence in such circumstances. One key challenge in evaluating NEs is selective exposure to the intervention. Studies should be based on a clear theoretical understanding of the processes that determine exposure. Even if the observed effects are large and rapidly follow implementation, confidence in attributing these effects to the intervention can be improved by carefully considering alternative explanations. Causal inference can be strengthened by including additional design features alongside the principal method of effect estimation.NEstudies often rely on existing (including routinely collected) data. Investment in such data sources and the infrastructure for linking exposure and outcome data is essential if the potential for such studies to inform decision making is to be realized

Extraction of moving objects from their background based on multiple adaptive thresholds and boundary evaluation

The extraction of moving objects from their background is a challenging task in visual surveillance. As a single threshold often fails to resolve ambiguities and correctly segment the object, in this paper, we propose a new method that uses three thresholds to accurately classify pixels as foreground or background. These thresholds are adaptively determined by considering the distributions of differences between the input and background images and are used to generate three boundary sets. These boundary sets are then merged to produce a final boundary set that represents the boundaries of the moving objects. The merging step proceeds by first identifying boundary segment pairs that are significantly inconsistent. Then, for each inconsistent boundary segment pair, its associated curvature, edge response, and shadow index are used as criteria to evaluate the probable location of the true boundary. The resulting boundary is finally refined by estimating the width of the halo-like boundary and referring to the foreground edge map. Experimental results show that the proposed method consistently performs well under different illumination conditions, including indoor, outdoor, moderate, sunny, rainy, and dim cases. By comparing with a ground truth in each case, both the classification error rate and the displacement error indicate an accurate detection, which show substantial improvement in comparison with other existing methods. © 2010 IEEE.published_or_final_versio

INTEROCC : Occupational exposure assessment for electromagnetic fields and risk of brain tumours. Development of a new source-based approach

Introducción: Con el fin de mejorar los métodos de evaluación de la exposición a campos electromagnéticos, desarrollamos un nuevo método basado en fuentes de exposición en lugar de códigos de ocupación. Mediciones obtenidas de la bibliografía fueron recopiladas, evaluadas y compiladas en una base de datos para ser posteriormente combinadas en forma de una matriz fuente-exposición. Esta matriz, junto a otros determinantes de la exposición, fue usada para calcular índices de exposición acumulada. El riesgo de mayor incidencia de tumores cerebrales, glioma y meningioma, se analizó usando estas estimaciones acumuladas. Los resultados del análisis mostraron un ligero incremento del riesgo de glioma en los grupos de trabajadores más expuestos a campos electromagnéticos de alta frecuencia en las ventanas de exposición más cercanas a la fecha de diagnóstico/referencia y en todas las ventanas para meningioma. En campos de frecuencia intermedia, se encontraron ligeros aumentos de riesgo solo en glioma en las ventanas de exposición más recientes. Estos resultados pueden reflejar que los campos electromagnéticos de alta frecuencia pueden tener un papel en las etapas más tardías de la carcinogénesis (promoción y progresión)Introduction: To improve exposure assessment methods for electromagnetic fields, we developed a methodology based on sources of exposure rather than job titles. Methods: Measurements collected from the literature were assessed and summarized into a source-exposure matrix (SEM). The SEM and personal determinants of exposure were combined to obtain individual indices cumulative exposure, which were used to assess risk of brain tumours, glioma an meningioma Results: Over 3,000 records were obtained and judged useful, creating a SEM with exposure estimates for 312 EMF sources. Overall the analysis yielded no association between glioma or meningioma risk and cumulative exposure to RF or IF EMF. However, some positive associations were identified for RF and IF EMF in the highest exposed groups in the 1- to 4-year exposure window for glioma, and in all windows for meningioma and RF only. These results might reflect a possible role of high frequency EMF in the later stages of carcinogenesis (promotion and progression)

Environ Int

Introduction:In 2011, the International Agency for Research on Cancer evaluated the epidemiological evidence for the association between occupational exposure to radiofrequency (RF) electromagnetic fields (EMF) and cancer as inadequate, due in part to limitations in exposure assessment. This study examines the relation between both occupational RF and intermediate frequency (IF) EMF exposure and brain tumour risk in the INTEROCC multinational case-control study population (nearly 10,000 subjects), using a novel exposure assessment approach.Methods:Individual indices of cumulative exposure to RF and IF-EMF were assigned to study participants using a source-exposure matrix and detailed interview data on work with or nearby EMF sources, both overall and in specific exposure time windows. Conditional logistic regression models were used to investigate associations with glioma and meningioma risk.Results:Overall, there was no clear evidence for an association between RF or IF-EMF and the brain tumours studied, with the vast majority of analyses showing no associations and in fact odds ratios (ORs) below one. The largest adjusted ORs were obtained for RF magnetic fields in the highest exposed category for the most recent exposure time window (1\u20134 years before the diagnosis or reference date) for both glioma (OR=1.62 (95% confidence interval (CI): 0.86, 3.01)) and meningioma (1.52 (CI: 0.65, 3.55)). Similar results were obtained using a continuous analysis.Conclusion:Despite the individualized approach used in this study, the largest case-control on brain tumours and EMF occupational exposures, no clear associations were identified. However, RF magnetic fields should be further investigated using more exposed participants and alternative exposure/dose metrics.CC999999/ImCDC/Intramural CDC HHSUnited States/R01 CA124759/CA/NCI NIH HHSUnited States/DH_/Department of HealthUnited Kingdom/MOP-42525/CIHRCanada/2022-02-17T00:00:00Z29996112PMC885138110973vault:4090

An Extended Macro-Finance Model with Financial Factors

This paper extends the benchmark Macro-Finance model by introducing, next to the standard macroeconomic factors, additional liquidity-related and return forecasting factors. Liquidity factors are obtained from a decomposition of the TED spread while the return-forecasting (risk premium) factor is extracted by imposing a single factor structure on the one-period expected excess holding returns. The model is estimated on US data using MCMC techniques. Two findings stand out. First, the model outperforms significantly most structural and non-structural Macro-Finance yield curve models in terms of cross-sectional fit of the yield curve. Second, we find that financial shocks, either in the form of liquidity or risk premium shocks, have a statistically and economically significant impact on the yield curve. The impact of financial shocks extends throughout the yield curve but is most pronounced at the high and intermediate frequencies.yield curve, affine models, macroeconomics and financial factors, Bayesian estimation

MODELLING VIRTUAL ENVIRONMENT FOR ADVANCED NAVAL SIMULATION

This thesis proposes a new virtual simulation environment designed as element of an interoperable federation of simulator to support the investigation of complex scenarios over the Extended Maritime Framework (EMF). Extended Maritime Framework is six spaces environment (Underwater, Water surface, Ground, Air, Space, and Cyberspace) where parties involved in Joint Naval Operations act. The amount of unmanned vehicles involved in the simulation arise the importance of the Communication modelling, thus the relevance of Cyberspace. The research is applied to complex cases (one applied to deep waters and one to coast and littoral protection) as examples to validate this approach; these cases involve different kind of traditional assets (e.g. satellites, helicopters, ships, submarines, underwater sensor infrastructure, etc.) interact dynamically and collaborate with new autonomous systems (i.e. AUV, Gliders, USV and UAV). The use of virtual simulation is devoted to support validation of new concepts and investigation of collaborative engineering solutions by providing a virtual representation of the current situation; this approach support the creation of dynamic interoperable immersive framework that could support training for Man in the Loop, education and tactical decision introducing the Man on the Loop concepts. The research and development of the Autonomous Underwater Vehicles requires continuous testing so a time effective approach can result a very useful tool. In this context the simulation can be useful to better understand the behaviour of Unmanned Vehicles and to avoid useless experimentations and their costs finding problems before doing them. This research project proposes the creation of a virtual environment with the aim to see and understand a Joint Naval Scenario. The study will be focusing especially on the integration of Autonomous Systems with traditional assets; the proposed simulation deals especially with collaborative operation involving different types of Autonomous Underwater Vehicles (AUV), Unmanned Surface Vehicles (USV) and UAV (Unmanned Aerial Vehicle). The author develops an interoperable virtual simulation devoted to present the overall situation for supervision considering also the sensor capabilities, communications and mission effectiveness that results dependent of the different asset interaction over a complex heterogeneous network. The aim of this research is to develop a flexible virtual simulation solution as crucial element of an HLA federation able to address the complexity of Extended Maritime Framework (EMF). Indeed this new generation of marine interoperable simulation is a strategic advantage for investigating the problems related to the operational use of autonomous systems and to finding new ways to use them respect to different scenarios. The research deal with the creation of two scenarios, one related to military operations and another one on coastal and littoral protection where the virtual simulation propose the overall situation and allows to navigate into the virtual world considering the complex physics affecting movement, perception, interaction and communication. By this approach, it becomes evident the capability to identify, by experimental analysis within the virtual world, the new solutions in terms of engineering and technological configuration of the different systems and vehicles as well as new operational models and tactics to address the specific mission environment. The case of study is a maritime scenario with a representation of heterogeneous network frameworks that involves multiple vehicles both naval and aerial including AUVs, USVs, gliders, helicopter, ships, submarines, satellite, buoys and sensors. For the sake of clarity aerial communications will be represented divided from underwater ones. A connection point for the latter will be set on the keel line of surface vessels representing communication happening via acoustic modem. To represent limits in underwater communications, underwater signals have been considerably slowed down in order to have a more realistic comparison with aerial ones. A maximum communication distance is set, beyond which no communication can take place. To ensure interoperability the HLA Standard (IEEE 1516 evolved) is adopted to federate other simulators so to allow its extensibility for other case studies. Two different scenarios are modelled in 3D visualization: Open Water and Port Protection. The first one aims to simulate interactions between traditional assets in Extended Maritime Framework (EMF) such as satellite, navy ships, submarines, NATO Research Vessels (NRVs), helicopters, with new generation unmanned assets as AUV, Gliders, UAV, USV and the mutual advantage the subjects involved in the scenario can have; in other word, the increase in persistence, interoperability and efficacy. The second scenario models the behaviour of unmanned assets, an AUV and an USV, patrolling a harbour to find possible threats. This aims to develop an algorithm to lead patrolling path toward an optimum, guaranteeing a high probability of success in the safest way reducing human involvement in the scenario. End users of the simulation face a graphical 3D representation of the scenario where assets would be represented. He can moves in the scenario through a Free Camera in Graphic User Interface (GUI) configured to entitle users to move around the scene and observe the 3D sea scenario. In this way, players are able to move freely in the synthetic environment in order to choose the best perspective of the scene. The work is intended to provide a valid tool to evaluate the defencelessness of on-shore and offshore critical infrastructures that could includes the use of new technologies to take care of security best and preserve themselves against disasters both on economical and environmental ones

Fit-for-Purpose Information for Offshore Wind Farming Applications—Part-I: Identification of Needs and Solutions

The rapid expansion of offshore wind farms (OWFs) in European seas is accompanied by many challenges, including efficient and safe operation and maintenance, environmental protection, and biodiversity conservation. Effective decision-making for industry and environmental agencies relies on timely, multi-disciplinary marine data to assess the current state and predict the future state of the marine system. Due to high connectivity in space (land–estuarial–coastal sea), socioeconomic (multi-sectoral and cross-board), and environmental and ecological processes in sea areas containing OWFs, marine observations should be fit for purpose in relation to multiple OWF applications. This study represents an effort to map the major observation requirements (Part-I), identify observation gaps, and recommend solutions to fill those gaps (Part-II) in order to address multi-dimension challenges for the OWF industry. In Part-I, six targeted areas are selected, including OWF operation and maintenance, protection of submarine cables, wake and lee effects, transport and security, contamination, and ecological impact assessments. For each application area, key information products are identified, and integrated modeling–monitoring solutions for generating the information products are proposed based on current state-of-the-art methods. The observation requirements for these solutions, in terms of variables and spatial and temporal sampling needs, are therefore identified.publishedVersio

Prospective Safety Analysis and the Complex Aviation System

Fatal accident rates in commercial passenger aviation are at historic lows yet have plateaued and are not showing evidence of further safety advances. Modern aircraft accidents reflect both historic causal factors and new unexpected "Black Swan" events. The ever-increasing complexity of the aviation system, along with its associated technology and organizational relationships, provides fertile ground for fresh problems. It is important to take a proactive approach to aviation safety by working to identify novel causation mechanisms for future aviation accidents before they happen. Progress has been made in using of historic data to identify the telltale signals preceding aviation accidents and incidents, using the large repositories of discrete and continuous data on aircraft and air traffic control performance and information reported by front-line personnel. Nevertheless, the aviation community is increasingly embracing predictive approaches to aviation safety. The "prospective workshop" early assessment tool described in this paper represents an approach toward this prospective mindset-one that attempts to identify the future vectors of aviation and asks the question: "What haven't we considered in our current safety assessments?" New causation mechanisms threatening aviation safety will arise in the future because new (or revised) systems and procedures will have to be used under future contextual conditions that have not been properly anticipated. Many simulation models exist for demonstrating the safety cases of new operational concepts and technologies. However the results from such models can only be as valid as the accuracy and completeness of assumptions made about the future context in which the new operational concepts and/or technologies will be immersed. Of course that future has not happened yet. What is needed is a reasonably high-confidence description of the future operational context, capturing critical contextual characteristics that modulate both the likelihood of occurrence of hazards, and the likelihood that those hazards will lead to negative safety events. Heuristics extracted from scenarios, questionnaires, and observed trends from scanning the aviation horizon may be helpful in capturing those future changes in a way conducive to safety assessment. What is also needed is a checklist of potential sources of emerging risk that arise from organizational features that are frequently overlooked. The ultimate goal is to develop a pragmatic, workable method for using descriptions of the future aviation context, to generate valid predictions of safety risks