Game Theoretic Strategies for Spacecraft Rendezvous and Motion Synchronization

The rendezvous problem between two active spacecraft is formulated as a two player nonzero-sum differential game. The local-vertical local-horizontal (LVLH) rotating reference frame is used to describe the dynamics of the game. Linear quadratic cooperative and noncooperative differential games are applied to obtain a feedback control law. A comparison between Pareto and Nash equilibria was then performed. The state-dependent Riccati equation (SDRE) method is applied to extend the Linear Quadratic differential game theory to obtain a feedback controller in the case of nonlinear relative motion dynamics. Finally, a multiplayer sequential game strategy is synthesized to extend the control law to the relative motion synchronization of multiple vehicles

Pianificare la mobilità urbana attraverso la cooperazione internazionale: l’esperienza del piano urbano della mobilità sostenibile di Herat

This paper deals with the planning process that led to the development of the Sustainable Urban Mobility Plan (SUMP) for the city of Herat, Afghanistan. Such planning experience is illustrated here with the aim of highlighting how the cooperative approach is applied to this case study, while trying to match the planning process to the local culture and to the essence of the Islamic city. If on one hand, the international cooperation brought a modern vision of urban mobility, aimed at increasing the levels of social, economic, and environmental sustainability, on the other hand the peculiarity of Herat’s urban context essentially influenced the planning process, for what concerned both methodology and results

The use of Open Data for estimating rail accessibility in Europe

Accessibility is a greatly significant concept for evaluating spatial interactions and transport systems attractiveness. The ability to accurately measure accessibility is becoming more and more crucial for setting up policies aimed to increase the competitiveness of a transport system by fostering resource efficient modes such as rail. Nevertheless, several rail accessibility studies consider only static variables, such as distance, average speed and travel time, neglecting the temporal components of the considered variables. These limitations are often due to the lack of detailed data. In order to overcome the mentioned weaknesses, this paper presents a comprehensive methodology aimed to evaluate passenger rail accessibility using open data from both time-based GTFS sources and Eurostat geographical layers. Based on passenger train timetable, a set of accessibility indicators are built for allowing a comprehensive analysis of railway connections. The analysis is performed taking into account the Eurostat Local Administrative Units (LAU level 2, municipalities or equivalent units) and the main urban centers definition based on the concept of Greater City established by EC DG REGIO and OECD. The developed methodology is then applied to three European countries (Netherlands, Great Britain and France) where GTFS data are currently available.JRC.J.1-Economics of Climate Change, Energy and Transpor

Measuring the impact of institutional and territorial drivers for an efficient and smooth Mobility as a Service (MaaS) implementation : a global analysis

Published online: May 2024Urban mobility plays a key role for the promotion of the socio-economic development of a country. Particularly, MaaS platforms are important for those daily journeys made by travellers that must be in a place by a certain time. Although, MaaS is the natural evolution of older supply models, it has a revolutionary impact on people’s lives. MaaS can optimize resources, urban space, reduce time spent travelling, lower costs and pollution. The present study aims at estimating the impact of a set of political and territorial drivers on MaaS implementation. The research is carried out using a composite set of indicators – 70 MaaS platforms in over 30 countries – for measuring how MaaS platforms perform in different territories. Results demonstrate a positive relationship between policies incentivising mobility services and business performance on those territories, and string territorial differences across the regions analysed

Detecting the gravito-magnetic field of the dark halo of the Milky Way - the LaDaHaD mission concept

We propose to locate transponders and atomic clocks in at least three of the Lagrange points of the Sun-Earth pair, with the aim of exploiting the time of flight asymme- try between electromagnetic signals travelling in opposite directions along polygonal loops having the Lagrange points at their vertices. The asymmetry is due to the pres- ence of a gravito-magnetic field partly caused by the angular momentum of the Sun, partly originating from the angular momentum of the galactic dark halo in which the Milky Way is embedded. We list also various opportunities which could be associated with the main objective of this Lagrange Dark Halo Detector (LaDaHaD)

Ultrasound-guided approach to surgery for nodal recurrence following lateral neck dissection for differentiated thyroid carcinoma. A single institution experience

IntroductionTotal thyroidectomy (TT) and central neck dissection (CND) had a significant effect on the reduction of local recurrence compared with TT alone. Lateral Neck Dissection (LND) was performed in all the cases with therapeutic intent. The suspicion of nodal recurrence is provided by the appearance of one or more enlarged nodes in the central and/or laterocervical compartment during the follow up period.MethodsFrom January 2018 to November 2023, 16 patients at the University General Surgery unit of the Polyclinic of Foggia underwent reoperation due to nodal recurrence after previously undergoing total thyroidectomy with central and lateral cervical dissection.ResultsAll surgical interventions were approached with intraoperative ultrasound performed by the operating surgeon. In all cases, ultrasound identification of the suspicious lymph node led to histological confirmation of malignancy. In only two cases it was necessary to carry out an extemporaneous intraoperative histological examination. No complications were recorded during the operations.ConclusionsSurgical reintervention in patients with nodal recurrence is challenging and requires an assessment by members of the interdisciplinary team. The ideal method should be economically convenient, easy to practice, with a quick learning curve, easily reproducible, and safe for patients. Intraoperative, ultrasound-guided, is a safe and effective technique. It facilitates tumor localization and removal, especially in patients requiring re-operative neck surgery

Gastroduodenal Lesions Associated with Portal Hypertension: An Extensive Review

The block of the portal flow by obstacles in prehepatic, hepatic or posthepatic site and alterations of the splanchnic blood flow are the pathological conditions that lead to portal hypertension. The portal hypertension can cause also others gastroduodenal lesions, potentially hemorrhagic, in addition to esophageal varices commonly developed and habitual source of bleeding in these patients. The gastroduodenal lesions associated with portal hypertension, usually encountered in the clinical practice, are portal hypertensive gastropaty, gastric antral vascular ectasia, gastric and duodenal ulcer, isolated gastric varices. The pathophysiology and clinical, diagnostic and therapeutic features of these lesions are examined

Transcriptomic differences in MSA clinical variants

Background: Multiple system atrophy (MSA) is a rare oligodendroglial synucleinopathy of unknown etiopathogenesis including two major clinical variants with predominant parkinsonism (MSA-P) or cerebellar dysfunction (MSA-C). Objective: To identify novel disease mechanisms we performed a blood transcriptomic study investigating differential gene expression changes and biological process alterations in MSA and its clinical subtypes. Methods: We compared the transcriptome from rigorously gender and age-balanced groups of 10 probable MSA-P, 10 probable MSA-C cases, 10 controls from the Catalan MSA Registry (CMSAR), and 10 Parkinson Disease (PD) patients. Results: Gene set enrichment analyses showed prominent positive enrichment in processes related to immunity and inflammation in all groups, and a negative enrichment in cell differentiation and development of the nervous system in both MSA-P and PD, in contrast to protein translation and processing in MSA-C. Gene set enrichment analysis using expression patterns in different brain regions as a reference also showed distinct results between the different synucleinopathies. Conclusions: In line with the two major phenotypes described in the clinic, our data suggest that gene expression and biological processes might be differentially affected in MSA-P and MSA-C. Future studies using larger sample sizes are warranted to confirm these results

Shake‐table tests on steel moment‐resisting frames with detachable yielding zones

AbstractThis article presents an experimental campaign based on shake table tests conducted as part of the European research project FUTURE, funded in the framework of the H2020‐INFRAIA SERA program. Three steel moment‐resisting frame structures equipped with replaceable dissipative elements were tested. The experimental mockups were scaled two thirds from a reference building archetype designed per the latest draft of the upcoming version of Eurocode 8. Each mockup has different bolted end‐plate beam‐to‐column joints, namely reduced beam section (RBS), extended stiffened endplate (ESEP), and Haunched types, designed with European seismic prequalification rules. Additionally, detachable column segments at the base were designed with Reduced Column Sections (RCS) to localize the plastic deformation and enforce the intended global dissipation mechanism. The slab was detailed with reduced areas around the columns to minimize the direct composite action at beam‐to‐column joints. The mockups were subjected to incremental near‐field excitations with combined horizontal and vertical components. In this article, the experimental campaign is first described, providing details on the mockup's geometry, design, scaling, ground excitations, and sensor distribution. Then, the observed global and local responses are discussed. The results demonstrate that the global response of the mockups was significantly influenced by the type of beam‐to‐column joints, which exhibited the expected damage. The RCS configuration in the column bases also showed satisfactory behavior without leading to local or global instabilities throughout the performed tests.</jats:p