Mean Field Games models of segregation

This paper introduces and analyses some models in the framework of Mean Field Games describing interactions between two populations motivated by the studies on urban settlements and residential choice by Thomas Schelling. For static games, a large population limit is proved. For differential games with noise, the existence of solutions is established for the systems of partial differential equations of Mean Field Game theory, in the stationary and in the evolutive case. Numerical methods are proposed, with several simulations. In the examples and in the numerical results, particular emphasis is put on the phenomenon of segregation between the populations.Comment: 35 pages, 10 figure

Mean field games models of segregation

This paper introduces and analyzes some models in the framework of mean field games (MFGs) describing interactions between two populations motivated by the studies on urban settlements and residential choice by Thomas Schelling. For static games, a large population limit is proved. For differential games with noise, the existence of solutions is established for the systems of partial differential equations of MFG theory, in the stationary and in the evolutive case. Numerical methods are proposed with several simulations. In the examples and in the numerical results, particular emphasis is put on the phenomenon of segregation between the populations. </jats:p

Thermal response of jointed rock masses inferred from infrared thermographic surveying (Acuto test-site, Italy)

The Mediterranean region is affected by considerable daily and seasonal temperature variations due to intense solar radiation. In mid-seasons, thermal excursions can exceed tens of degrees thus influencing the long-term behaviour of jointed rock masses acting as a preparatory factor for rock slope instabilities. In order to evaluate the thermal response of a densely jointed rock-block, monitoring has been in operation since 2016 by direct and remote sensing techniques in an abandoned quarry in Acuto (central Italy). Monthly InfraRed Thermographic (IRT) surveys were carried out on its exposed faces and along sections of interest across monitored main joints. The results highlight the daily and seasonal cyclical behaviour, constraining amplitudes and rates of heating and cooling phases. The temperature time-series revealed the effect of sun radiation and exposure on thermal response of the rock-block, which mainly depends on the seasonal conditions. The influence of opened joints in the heat propagation is revealed by the differential heating experienced across it, which was verified under 1D and 2D analysis. IRT has proved to be a valid monitoring technique in supporting traditional approaches, for the definition of the surficial temperature distribution on rock masses or stone building materials

Why Are We Here? On the (Philosophical) Value of Documents

What does a philosopher do with documents? The most natural answer to this question would probably be that philosophers, as writers, produce documents. What would appear as less intuitive, though, is a philosopher producing documents about documents. But philosophy—and in particular ontology—has always been interested in what there is out there in the world. And documents are a peculiar class of objects, the stuff the world is filled with. This year, the Annual Meeting of the Document Academy has been hosted by a philosophy department for the first time: by the Department of Philosophy of the University of Turin. This editorial introduces the proceedings from this meeting

Organizing and Promoting Value Services in Public Sector by a New E-government Approach

To strengthen democracy, promote government efficiency and effectiveness, discourage wastes and misuses of government resources, public administrations have to promote a new stronger level of openness in government. The purpose of this manuscript is to describe an innovative approach for the governance of public systems and services, currently applied in the Italian public administration domain, which could be easily replicated in other countries as well. Two initiatives, to collect and provide relevant public information gathered from different and heterogeneous public organizations, to improve government processes and increase quality of services for citizens and companies, are described. The cases adopted have been validated through a case analysis approach involving the Italian Agency for the public administration digitalization to understand new e-government scenarios within the context of governmental reforms heavily influenced by the principles of Open Government Model.To strengthen democracy, promote government efficiency and effectiveness, discourage wastes and misuses of government resources, public administrations have to promote a new stronger level of openness in government. The purpose of this manuscript is to describe an innovative approach for the governance of public systems and services, currently applied in the Italian public administration domain, which could be easily replicated in other countries as well. Two initiatives, to collect and provide relevant public information gathered from different and heterogeneous public organizations, to improve government processes and increase quality of services for citizens and companies, are described. The cases adopted have been validated through a case analysis approach involving the Italian Agency for the public administration digitalization to understand new e-government scenarios within the context of governmental reforms heavily influenced by the principles of Open Government Model.Invited Submission

Impact of Access Line Capacity on Adaptive Video Streaming Quality - A Passive Perspective

Adaptive streaming over HTTP is largely used to deliver live and on-demand video. It works by adjusting video quality according to network conditions. While QoE for different streaming services has been studied, it is still unclear how access line capacity impacts QoE of broadband users in video sessions. We make a first step to answer this question by characterizing parameters influencing QoE, such as frequency of video adaptations. We take a passive point of view, and analyze a dataset summarizing video sessions of a large population for one year. We first split customers based on their estimated access line capacity. Then, we quantify how the latter affects QoE metrics by parsing HTTP requests of Microsoft Smooth Streaming (MSS) services. For selected services, we observe that at least 3~Mbps of downstream capacity is needed to let the player select the best bitrate, while at least 6~Mbps are required to minimize delays to retrieve initial fragments. Surprisingly, customers with faster access lines obtain limited benefits, hinting to restrictions on the design of services

Measuring Web Speed From Passive Traces

Understanding the quality of Experience (QoE) of web brows- ing is key to optimize services and keep users’ loyalty. This is crucial for both Content Providers and Internet Service Providers (ISPs). Quality is subjective, and the complexity of today’s pages challenges its measurement. OnLoad time and SpeedIndex are notable attempts to quantify web performance with objective metrics. However, these metrics can only be computed by instrumenting the browser and, thus, are not available to ISPs. We designed PAIN: PAssive INdicator for ISPs. It is an automatic system to monitor the performance of web pages from passive measurements. It is open source and available for download. It leverages only flow-level and DNS measurements which are still possible in the network despite the deployment of HTTPS. With unsupervised learn- ing, PAIN automatically creates a machine learning model from the timeline of requests issued by browsers to render web pages, and uses it to measure web performance in real- time. We compared PAIN to indicators based on in-browser instrumentation and found strong correlations between the approaches. PAIN correctly highlights worsening network conditions and provides visibility into web performance. We let PAIN run on a real ISP network, and found that it is able to pinpoint performance variations across time and groups of users