1,310 research outputs found
A Grid architectural approach applied for backward compatibility to a production system for events simulation.
No full textDistributed systems paradigm gained in popularity during the last 15 years, thanks also to the broad diffusion of distributed frameworks proposed for the Internet plat form. In the late ’90s a new concept started to play a main role in the field of distributed computing: the Grid.
This thesis presents a study related to the integration between the BaBar’s framework, an experiment belonging to the High Energy Physics field, and a grid system like the one implemented by the Italian National Institute for Nuclear Physics (INFN), the INFNGrid project, which provides
support for several research domains. The main goal was to succeed in adapt an already well established system, like the one implemented into the BaBar pipeline and based on local centers not interconnected between themselves, to a kind of technology that was not ready by the time the
experiment’s framework was designed. Despite this new approach was related just to some aspects of the experiment, the production of simulated events by using MonteCarlo methods, the efforts here described represent an example of how an old experiment can bridge the gap toward the Grid computing, even adopting solutions designed for more recent projects.
The complete evolution of this integration will be explained starting from the earlier stages until the
actual development to state the progresses achieved, presenting results that are comparable with
production rates gained using the conventional BaBar’s approach, in order to examine the potentially benefits and drawbacks on a concrete case study
New microscopic indicators for evaluating traffic efficiency and safety
No full textImproving both safety and efficiency in traffic systems remains a central challenge, especially in the context of increasingly mixed traffic with autonomous and human-driven vehicles. Although many indicators assess either safety or efficiency, few capture both dimensions simultaneously at a microscopic level. This paper introduces two new traffic indicators: Efficiency Index (EI), which measures local speed and spacing regularity, and Safety and Efficiency Index (SEI), which combines EI with a time-to-collision safety component. A tunable version, SEMI, allows greater sensitivity to risk by penalizing safety-critical interactions. Using real-world traffic flow data and simulation via SUMO, we tested these indicators in varying penetration rates of autonomous vehicles. The results show that while AVs improve efficiency across the board, the safety gains become especially pronounced in dense traffic. These findings offer a flexible and interpretable tool for researchers and practitioners in traffic engineering, vehicle automation, and public policy. The proposed indicators can inform the design of AV control models, traffic management strategies, and infrastructure planning where safety-efficiency trade-offs must be explicitly addressed
Expanding the role of coagulation in arterial thrombosis: evidence from animal models using a new factor Xa inhibitor
No full textN/
Potential impact of autonomous vehicles in mixed traffic from simulation using real traffic flow
No full textThis work focuses on the potential impacts of the autonomous vehicles in a mixed traffic condition represented in traffic simulator Simulation of Urban MObility (SUMO) with real traffic flow. Specifically, real traffic flow and speed data collected in 2002 and 2019 in Gothenburg were used to simulate daily flow variation in SUMO. In order to predict the most likely drawbacks during the transition from a traffic consisting only manually driven vehicles to a traffic consisting only fully-autonomous vehicles, this study focuses on mixed traffic with different percentages of autonomous and manually driven vehicles. To realize this aim, several parameters of the car following and lane change models of autonomous vehicles are investigated in this paper. Along with the fundamental diagram, the number of lane changes and the number of conflicts are analyzed and studied as measures for improving road safety and efficiency. The study highlights that the autonomous vehicles\u27 features that improve safety and efficiency in 100% autonomous and mixed traffic are different, and the ability of autonomous vehicles to switch between mixed and autonomous driving styles, and vice versa depending on the scenario, is necessary
Modelling Ecological Systems from a Niche Theory to Lotka-Volterra Equations
No full textThis paper is an attempt to analyze the notion of ecological niche as a community of different species and of ecosystem as a set of niches in order to formulate a dynamical model for an ecosystem. Our assumption is that the concept of fitness landscape allows to model the phenotype dynamics of an ensemble of species as a stochastic process. To take into account the interaction structure of different communities in the niches and the environment we introduce an ecological fitness potential to formulate a Lotka-Volterra system which describes the evolution of a mutual ecosystem in presence of finite resources. To explicitly consider the effect of fluctuations in the numerousness of the species, we associate a master equation to the average Lotka-Volterra system and we study the conditions of existence of a detailed balance equilibrium (i.e. a thermodynamic equilibrium) for the ecosystem. The explicit solution for the equilibrium probability distribution is a multinomial negative distribution and we discuss the relation between the detailed balance condition and relative species abundance distribution in the framework of Hubbell’s neutral theory. Moreover the theoretical distribution implies the existence of a correlation among the relative species distribution associated to the different communities. We use numerical simulations to illustrate the results on simple models
On the cospectrality between graphs and pseudographs
No full textIn this paper we introduce a spectrum-preserving relation between graphs with loops and graphs without loops. Our approach generalizes the spectral results obtained on
stars to a wider class of graphs, namely
stars with or without loops. The proposed equivalence of the two classes of graphs allows to study pseudographs as simple graphs, by extending the techniques developed for simple graphs to pseudographs, without losing information, and it could be relevant for applications of graph theory to complex systems physics and neural networks. Finally, in order to make the demonstrated results easily applicable, we have provided a public Github repository where Python code that allows straightforward implementations of the outcomes is made available
Safety-centred analysis of transition stages to traffic with fully autonomous vehicles
No full textThe aim of this paper is to highlight and investigate the effects of increasing presence rate of autonomous vehicles (AVs) in terms of traffic safety and traffic flow characteristics. For this purpose, using existing driver models in traffic simulator SUMO we identify and analyze those parameters that characterize and distinguish AVs' driving from manual driving in a heterogeneous traffic context. While it is essential to identify the parameters for traffic flow characteristics of heterogeneous fleets compared to homogeneous ones comprising manually driven vehicles (MV) only (i.e. current status), the safety aspects must be also accounted for. In order to combine these two fundamental aspects of heterogeneous traffic, we used a complete description of a highway driving scenario. The scenario integrates the perceptions of different type of vehicles (i.e. AV and MV) involved and the reaction times of human drivers and decision-making units of autonomous vehicles, to explore the impact of both the rate of AV presence and the perturbation in perception capabilities in highway scenarios
Simulated Events Production on the Grid for the BaBar Experiment
No full textThe BaBar experiment uses data since 1999 in examining the violation of charge and parity (CP) symmetry in the field of high energy physics. This event simulation experiment is a compute intensive task due to the complexity of the Monte-Carlo simulation implemented on the GEANT engine. Data needed as input for the simulation (stored in the ROOT format), are classified into two categories: conditions data for describing the detector status when data are recorded, and background triggers data for noise signal necessary to obtain a realistic simulation. In this chapter, the grid approach is applied to the BaBar production framework using the INFN-GRID network.</jats:p
Signless Normalized Laplacian for Hypergraphs
No full textThe spectral theory of the normalized Laplacian for chemical hypergraphs is
further investigated. The signless normalized Laplacian is introduced and it is
shown that its spectrum for classical hypergraphs coincides with the spectrum
of the normalized Laplacian for bipartite chemical hypergraphs. Furthermore,
the spectra of special families of hypergraphs are established
“but I am also influenced by no such thing”-The Radical Pietist and Theological Author Johanna Eleonora Petersen
No full textJohanna Eleonora von und zu Merlau, verheiratete Petersen, von jeher tief gläubig, veränderte die religiöse Welt des 17. Jahrhunderts. Sie bekannte sich zur Bewegung des Pietismus und vertrat radikale Ansichten, nicht nur im privaten Kreis, sondern als anerkannte und heftig kritisierte theologische Autorin. Ihrem Werk ist eine Studie gewidmet, in der neue Forschungsergebnisse vorgestellt und Leben und Werk dieser bedeutenden Autorin in zeitgenössische Diskurse eingebunden werden.The deeply devout Johanna Eleonora Petersen, whose maiden name was „von und zu Merlau,” changed the religious world of the seventeenth century. She avowed herself to Pietism and held radical views, not only in private but also as an acknowledged and sharply criticized theological author. This study attends to her work. It presents new research results and weaves the life and work of this important author into contemporary discourses
- …
