CrisMap: A Big Data Crisis Mapping System Based on Damage Detection and Geoparsing

Natural disasters, as well as human-made disasters, can have a deep impact on wide geographic areas, and emergency responders can benefit from the early estimation of emergency consequences. This work presents CrisMap, a Big Data crisis mapping system capable of quickly collecting and analyzing social media data. CrisMap extracts potential crisis- related actionable information from tweets by adopting a classification technique based on word embeddings and by exploiting a combination of readily-available semantic annotators to geoparse tweets. The enriched tweets are then visualized in customizable, Web-based dashboards, also leveraging ad-hoc quantitative visualizations like choropleth maps. The maps produced by our system help to estimate the impact of the emergency in its early phases, to identify areas that have been severely struck, and to acquire a greater situational awareness. We extensively benchmark the performance of our system on two Italian natural disasters by validating our maps against authoritative data. Finally, we perform a qualitative case-study on a recent devastating earthquake occurred in Central Italy

Nowcasting of Earthquake Consequences Using Big Social Data

Messages posted to social media in the aftermath of a natural disaster have value beyond detecting the event itself. Mining such deliberately dropped digital traces allows a precise situational awareness, to help provide a timely estimate of the disaster’s consequences on the population and infrastructures. Yet, to date, the automatic assessment of damage has received little attention. Here, the authors explore feeding predictive models by tweets conveying on-the-ground social sensors’ observations, to nowcast the perceived intensity of earthquakes

Performance evaluation of the barycentric server model for mobile ad-hoc networks

By adopting code mobility techniques, distributed applications can make better use of network resources. This makes logical mobility particularly attractive in a mobile computing scenario, where the level of network resources changes continuously. However, it is sometimes difficult to express quantitatively the benefits, and also the overhead, introduced by logical mobility. In this paper, we present the performance evaluation of a migration model where the central component of the application, the server, moves towards the physical barycenter of a network made of mobile hosts. We evaluated both application-level metrics, such as the percentage of delivered messages and communication latency, and network-level metrics, such as the number of routed messages. In many cases, logical mobility contributed to a significant improvement of the considered performance indexes

Internet Emulation for Java Applications through Socket Factories

Network emulation provides the capability of evaluating distributed applications on a stand-alone system: Applications can be exposed to adverse and repeatable network conditions without requiring complex testbeds. This paper describes the design and implementation of a portable and object-oriented network emulator targeted to the development and test of Java-based Internet applications. The emulator is based on instrumented sockets, say EmuSockets, able to emulate the behavior of links with a given bandwidth and communication delay. The emulator is organized modularly, so that it is possible to plug-in user-defined classes for bandwidth and delay figures generation. Carrying out experiments with EmuSockets is as simple as running the tested application code on a single host

MobileRMI: a toolkit for enhancing Java Remote Method Invocation with mobility

The benefits introduced by the use of mobile code and mobile objects have been highlighted in numerous research works, but their adoption in real-world applications is still missing. We argue that the lack of integration between the language support for mobility and the usual programming environment, can reduce the advantages and limit the diffusion of such design paradigms. We try to contribute to bridge this gap by proposing MobileRMI, a toolkit that enhances the UnicastRemoteObject class of Java RMI by adding methods for creating objects in a remote address space, as well as of moving them from an address space to another. After migration, a remote object is still reachable from any client application that holds a reference to it