Search results for " Simulation"

Physical Metaphor for Streaming Media Retargeting

2014

We here introduce an image/video retargeting method that operates arbitrary aspect ratios resizing achieved in real-time performances. Most of the literature retargeting approaches sacrifice real-time performances in behalf of quality. On the other hand, existing fast methods provide arguable results. We can obtain a valuable trade-off between effectiveness and efficiency. The method named Spring Simulation Retargeting (SSR) is mainly based on a physical springs-based simulation. The media are assumed as flexible objects composed of particles and springs with different local stiffness properties, related to the visual importance of the content. The variation of the object size generates ela…

A Framework for Parallel Assessment of Reputation Management Systems

2016

Several distributed applications running over the Internet use Reputation Management Systems (RMSs) to guarantee reliable interactions among unknown agents. Because of the heterogeneity of the existing RMSs, their assessment in terms of correctness and resistance to security attacks is not a trivial task. This work addresses this issue by presenting a novel parallel simulator aimed to support researchers in evaluating the performances of a RMS since the design phase. Preliminary results obtained by simulating two different attacks confirm the suitability of the proposed framework to evaluate different RMSs.

A Simulation Software for the Evaluation of Vulnerabilities in Reputation Management Systems

2019

Multi-agent distributed systems are characterized by autonomous entities that interact with each other to provide, and/or request, different kinds of services. In several contexts, especially when a reward is offered according to the quality of service, individual agents (or coordinated groups) may act in a selfish way. To prevent such behaviours, distributed Reputation Management Systems (RMSs) provide every agent with the capability of computing the reputation of the others according to direct past interactions, as well as indirect opinions reported by their neighbourhood. This last point introduces a weakness on gossiped information that makes RMSs vulnerable to malicious agents’ intent …

Human Mobility Simulator for Smart Applications

2019

Several issues related to Smart City development require the knowledge of accurate human mobility models, such as in the case of urban development planning or evacuation strategy definition. Nevertheless, the exploitation of real data about users' mobility results in severe threats to their privacy, since it allows to infer highly sensitive information. On the contrary, the adoption of simulation tools to handle mobility models allows to neglect privacy during the design of location-based services. In this work, we propose a simulation tool capable of generating synthetic datasets of human mobility traces; then, we exploit them to evaluate the effectiveness of algorithms which aim to detect…

Vulnerability evaluation of distributed reputation management systems

2017

In distributed environments, Reputation Management Systems (RMSs) aim to estimate agents' trustworthiness by exploiting different sources of information. The distributed nature of these systems makes them vulnerable to several types of security attacks, and the response provided by a specific RMS depends on various factors, such as the algorithms adopted for estimating the reputation values and the communication protocols used to enable the cooperation among agents. This work examines the most important security attacks against RMSs and proposes a set of metrics for a quantitative evaluation of the RMS vulnerabilities. A parallel simulation framework is used to automatically give a vulnerab…

Evaluating Correlations in IoT Sensors for Smart Buildings

2021

International audience; In this paper we introduce a dataset of environmental information obtained via indoor and outdoor sensors deployed in the SMART Infrastructure Facility of the University of Wollongong (Australia). The acquired dataset is also made open-sourced along with this paper. We also propose a novel approach based on an evolutionary algorithm to determine pairs of correlated sensors. We compare our approach with three other standard techniques on the same dataset: on average, the accuracy of the evolutionary method is about 62,92%. We also evaluate the computational time, assessing the suitability of the proposed pipeline for real-time applications.

Motor simulation via coupled internal models using sequential Monte Carlo

2011

We describe a generative Bayesian model for action understanding in which inverse-forward internal model pairs are considered 'hypotheses' of plausible action goals that are explored in parallel via an approximate inference mechanism based on sequential Monte Carlo methods. The reenactment of internal model pairs can be considered a form of motor simulation, which supports both perceptual prediction and action understanding at the goal level. However, this procedure is generally considered to be computationally inefficient. We present a model that dynamically reallocates computational resources to more accurate internal models depending on both the available prior information and the predic…

Robotic and virtual World Programming labs to Stimulate Reasoning and visual-spatial Abilities

2013

Abstract The individuals’ cognitive skills, academic performance and their relationship with programming of robots or virtual learning environment is a topic of particular interest in the area of human-robot interaction. This paper presents a pilot study performed on a group of 36 lower secondary school students involved in a 32-hours laboratory based on the combination of LEGO Mindstorm NXT and Microsoft Kodu Game Lab (KGL) and aimed at programming first a robot and further a more complete virtual world based on a narrative-designed scenario. The findings of the research will be discussed in the light of the effectiveness of using robotics and virtual world programming as a meaningful and …

A nonlinear System Model of Retirement Behavior in Italy

2010

Smoothed Particle Electromagnetics Modelling on HPC-GRID Environment

2012

In this paper a meshless approach on a high performance grid computing environment to run fast onerous electromagnetic numerical simulations, is presented. The grid computing and the message passing interface standard have been employed to improve the computational efficiency of the Smoothed Particle Electromagnetics meshless solver adopted. Applications involving an high number of particles can run on a grid computational environment simulating complex domains not accessible before and offer a promising approach for the coupling of particle models to continuous models. The used meshless solver is straightforward to program and fully parallelizable. The results of the parallel numerical sch…