A State-of-the-art Integrated Transportation Simulation Platform

Nowadays, universities and companies have a huge need for simulation and modelling methodologies. In the particular case of traffic and transportation, making physical modifications to the real traffic networks could be highly expensive, dependent on political decisions and could be highly disruptive to the environment. However, while studying a specific domain or problem, analysing a problem through simulation may not be trivial and may need several simulation tools, hence raising interoperability issues. To overcome these problems, we propose an agent-directed transportation simulation platform, through the cloud, by means of services. We intend to use the IEEE standard HLA (High Level Architecture) for simulators interoperability and agents for controlling and coordination. Our motivations are to allow multiresolution analysis of complex domains, to allow experts to collaborate on the analysis of a common problem and to allow co-simulation and synergy of different application domains. This paper will start by presenting some preliminary background concepts to help better understand the scope of this work. After that, the results of a literature review is shown. Finally, the general architecture of a transportation simulation platform is proposed

Densifying the sparse cloud SimSaaS: The need of a synergy among agent-directed simulation, SimSaaS and HLA

Modelling & Simulation (M&S) is broadly used in real scenarios where making physical modifications could be highly expensive. With the so-called Simulation Software-as-a-Service (SimSaaS), researchers could take advantage of the huge amount of resource that cloud computing provides. Even so, studying and analysing a problem through simulation may need several simulation tools, hence raising interoperability issues. Having this in mind, IEEE developed a standard for interoperability among simulators named High Level Architecture (HLA). Moreover, the multi-agent system approach has become recognised as a convenient approach for modelling and simulating complex systems. Despite all the recent works and acceptance of these technologies, there is still a great lack of work regarding synergies among them. This paper shows by means of a literature review this lack of work or, in other words, the sparse Cloud SimSaaS. The literature review and the resulting taxonomy are the main contributions of this paper, as they provide a research agenda illustrating future research opportunities and trends

Gas clumping in galaxy clusters

The reconstruction of galaxy cluster's gas density profiles is usually performed by assuming spherical symmetry and averaging the observed X-ray emission in circular annuli. In the case of a very inhomogeneous and asymmetric gas distribution, this method has been shown to return biased results in numerical simulations because of the $n^2$ dependence of the X-ray emissivity. We propose a method to recover the true density profiles in the presence of inhomogeneities, based on the derivation of the azimuthal median of the surface brightness in concentric annuli. We demonstrate the performance of this method with numerical simulations, and apply it to a sample of 31 galaxy clusters in the redshift range 0.04-0.2 observed with ROSAT/PSPC. The clumping factors recovered by comparing the mean and the median are mild and show a slight trend of increasing bias with radius. For $R<R_{500}$, we measure a clumping factor $\sqrt{C}<1.1$, which indicates that the thermodynamic properties and hydrostatic masses measured in this radial range are only mildly affected by this effect. Comparing our results with three sets of hydrodynamical numerical simulations, we found that non-radiative simulations significantly overestimate the level of inhomogeneities in the ICM, while the runs including cooling, star formation, and AGN feedback reproduce the observed trends closely. Our results indicate that most of the accretion of X-ray emitting gas is taking place in the diffuse, large-scale accretion patterns rather than in compact structures.Comment: 12 pages, 11 figures, accepted for publication in MNRAS. Largely-improved version compared to v1, method and comparison with simulations update

Radio polarimetry of compact steep spectrum sources at sub-arcsecond resolution

Aims - We report new Very Large Array polarimetric observations of Compact Steep-Spectrum (CSS) sources at 8.4, 15, and 23GHz. Methods - Using multi-frequency VLA observations we have derived sub-arcsecond resolution images of the total intensity, polarisation, and rotation measure (RM) distributions. Results heading - We present multi-frequency VLA polarisation observations of CSS sources. About half of the sources are point-like even at the resolution of about 0.1x0.1 arcseconds. The remaining sources have double or triple structure. Low values for the percentage of polarised emission in CSS sources is confirmed. On the average, quasars are more polarised than galaxies. A wide range of RM values have been measured. There are clear indications of very large RMs up to 5\,585 rad m**(-2). CSS galaxies are characterized by RM values that are larger than CSS quasars. The majority of the objects show very large values of RM. Conclusions - The available data on sub-arcsecond-scale rest-frame RM estimates for CSS sources show that these have a wide range of values extending up to about 36,000 rad m**(-2). RM estimates indicate an overall density of the magneto-ionic medium larger than classical radio sources.Comment: Accepted for publication by Astronomy & Astrophysic

Performance Evaluation of a Medium-temperature Solar Cooling Plant

AbstractSolar cooling plants represent today an interesting solution for air conditioning and primary energy savings. However, the plant configurations are still on development and the different solutions are tested in pilot plants. In this paper, a study on a possible high-efficiency configuration has been conducted. This solar cooling plant is based on a linear parabolic collectors solar field operating at 160- 180°C and coupled with a double effect absorption chiller. This solution could lead to an energy performance near to the DEC technology but with lower investment costs. A numerical model in TRNSYS has been developed in order to evaluate the performance and the possibility to build a pilot plant in the RSE experimental area. Thanks to the model, the system design process was studied and were identified the most important parameters (area of the solar field, nominal power of the absorption chillers, and volumes of the heat storage). The way how these parameters affect the overall performance of the plant has been investigated and a sizing procedure for solar cooling plant with a nominal refrigeration power of 20 – 45kW was developed. A building in the RSE area was chosen and the procedure has been applied in order to design a dedicated solar cooling plant

“Narrating” bodies : physical “reflexive” activities between gender images and socio-pedagogical processes : research on the yoga’s representations

This article intends to offer a reflection on how reflexive physical activities can support a socio-pedagogical approach to educating about gender diversity through media communication. We use the term “reflexive” to refer to all those activities aimed at enhancing the person and his relationships, self-realization, selfknowledge, and self-improvement: in other terms, a circuit of bodily experiences that determine bodily knowledge as a social construction (as described by Connel, 2005). These activities focus mainly on ethical purposes, rather than on performative ones. An example of such disciplines can be considered the practice of yoga which is a currently growing phenomenon both in Europe and in the United States. Yoga is practiced today in the USA by 35.2 million adults, by over 2.5 million people in Italy, and is garnering scientific interest in its contributions to balanced, healthy growth of children and adults. The World Health Organization, in its global action plan on physical activity 2018-2030: More Active People for a Healthier World, calls it a means to improve health. The diffusion of these disciplines responds to a personal and social search for meaning that weighs especially heavily on highly secularized Western culture. This diffusion also portrays a media phenomenon, whose images and messages validate and reinforce capitalist ethics. From this point of view, the “mediated” representation of sports bodies appears to apply to the world of consumers. The images of women practicing yoga, oriented toward alternative values rather than beauty and sexuality, are above all confirmed by the purchase of goods and services that are not related to outward personal appearance. Using the results of an analysis carried out in 2021 of two main international yoga magazines, we are going to discuss the role of yoga as a “reflexive” physical activity and its pedagogical potential oriented to the body as a “primary place of experience”, not just a consumer item, but also a tool for education about gender diversity

Back and forth from cool core to non-cool core: clues from radio-halos

X-ray astronomers often divide galaxy clusters into two classes: "cool core" (CC) and "non-cool core" (NCC) objects. The origin of this dichotomy has been the subject of debate in recent years, between "evolutionary" models (where clusters can evolve from CC to NCC, mainly through mergers) and "primordial" models (where the state of the cluster is fixed "ab initio" by early mergers or pre-heating). We found that in a well-defined sample (clusters in the GMRT Radio halo survey with available Chandra or XMM-Newton data), none of the objects hosting a giant radio halo can be classified as a cool core. This result suggests that the main mechanisms which can start a large scale synchrotron emission (most likely mergers) are the same that can destroy CC and therefore strongly supports "evolutionary" models of the CC-NCC dichotomy. Moreover combining the number of objects in the CC and NCC state with the number of objects with and without a radio-halo, we estimated that the time scale over which a NCC cluster relaxes to the CC state, should be larger than the typical life-time of radio-halos and likely shorter than about 3 Gyr. This suggests that NCC transform into CC more rapidly than predicted from the cooling time, which is about 10 Gyr in NCC systems, allowing the possibility of a cyclical evolution between the CC and NCC states.Comment: Accepted for publication in A&