Search results for "virtu"
showing 10 items of 1987 documents
Tuning Java to Run Interactive Multiagent Simulations over Jason
2010
Java-based simulation environments are currently used by many multiagent systems (MAS), since they mainly provide portability as well as an interesting reduction of the development cost. However, this kind of MAS are rarely considered when developing interactive applications with time response constraints. This paper analyses the performance provided by Jason, a well-known Java-based MAS platform, as a suitable framework for developing interactive multiagent simulations. We show how to tune both the heap size and the garbage collection of the Java Virtual Machine in order to achieve a good performance while executing a simple locomotion benchmark based on crowd simulations. Furthermore, the…
The hyplet : Joining a Program and a Nanovisor for real-time and Performance
2020
This paper presents the concept of sharing a hyper-visor address space with a standard Linux program. In this work, we add hypervisor awareness to the Linux kernel and execute code in the HYP exception level through using the hyplet. The hyplet is an innovative way to code interrupt service routines and remote procedure calls under ARM. The hyplet provides high performance and run-time predictability. We demonstrate the hyplet implementation using the C programming language on an ARM8v-a platform and under the Linux kernel. We then provide performance measurements, use cases, and security scenarios. peerReviewed
Nuove ricerche a Solunto (2021)
2021
New researches in Solunto (2021) · The paper presents an overview of the ongoing researches in Solunto by the University of Palermo. In 2021 stratigraphical sondages were undertaken in two areas of the town: 1) in the great sanctuary above the theatre, in the frame of a major project aimed at addressing several still unresolved issues. That area, as a matter of fact, has never been considered as a whole; the sacred buildings have not been studied, and their mutual relationships and the links with the adjacent terraces have never been properly examined; 2) in the North Baths near the agora, as a corollary of the systematic study of water management, some sondages were made by G. Polizzi. Fin…
The Old Guard Under a New Order: K. O. Friedrichs Meets Felix Klein
2018
Constance Reid’s recent tribute to K. O. Friedrichs (Reid 1983) undoubtedly brought back fond memories to those who knew the man and his many achievements (see also Reid 1986). It was a great pleasure for me to interview Friedrichs in January 1982, only about a year before his death. He was already in very delicate health. His wife Nellie (see Biegel 2012) was kind enough to arrange the interview, but warned me beforehand that her husband tired rather easily and was somewhat hard of hearing. Nevertheless, he was extremely forthcoming in discussing his early career with me, and quick to dismiss some of my faulty misconceptions regarding Gottingen mathematics in the 1920s, which was the main …
Study of 3D sound for an audio-visual interaction in enriched virtual environment
2011
Most of the applications integrating 3D sound in virtual environment are limited to acoustic simulation. The objective of this thesis is to study the added value of 3D sound in the interaction with virtual environment. We developed an audio stimulation technique called "Artificial Spatial Audio Sensation: (ASAS)" based on the creation of audio effects. This technique conveys the sensations of spatialized sound that allows accurate sound source localization in azimuth and in elevation. In order to improve the localization time we also developed a model that integrates Head-Related Transfer Function (HRTF) with the ASAS technique. For the simulation of the depth of spatial sound sources, we d…
Linearizing Auditory Distance Estimates by Means of Virtual Acoustics
2008
Auditory distance estimates are not linearly related to physical distances: people tend to overestimate close physical distances, and underestimate far distances [I]. We have modeled a virtual listening environment whose objective is to provide a linear relationship between perceived and physical distance. The simulated environment consists of a trapezoidal membrane with specific absorbing properties at the boundaries. A physics-based model simulates acoustic wave propagation in this virtual space and provides auditory distance cues, namely intensity and direct-to-reverberant energy ratio. Simulations predict the linearity of the psychophysical function relating physical distance to perceiv…
Increasing GP Computing Power for Free via Desktop GRID Computing and Virtualization
2009
This paper presents how it is possible to increase the Genetic Programming (GP) Computing Power (CP) for free, via Volunteer Computing (VC), using the well known framework BOINC plus a new ``virtualization'' layer which adds all the benefits from the virtualization paradigm. Two different experiments, employing a standard GP tool and a complex GP system, are performed --with distributed PCs over several cities-- to show the free achieved CP by means of VC, without the necessity of modifying or adapting the original GP source code. The methodology can be easily extended to Evolutionary Algorithms (EAs).
Virtual Reality Based Simulators for Neurosurgeons - What We Have and What We Hope to Have in the Nearest Future
2018
High levels of manual skills, good visual-motor coordination, excel‐lent imagination and spatial awareness are the main factors determining the success of neurosurgeons. Proficiency in neurosurgical skills used to be acquired through hands-on training in cadaver labs and in real operating theatres under master neurosurgeon supervision. Most recently, virtual reality (VR) and augmented reality (AR) computer simulations have also been considered as tools for education in the neurosurgical training. The authors review existing solutions and present their own concept of a simulator which could become the useful tool for planning, simulation and training of a specific neurosurgical procedure usi…
A method to transform a nonlocal model into a gradient one within elasticity and plasticity
2014
Abstract A method based on the principle of the virtual power (PVP) is presented, by which a mechanical problem of nonlocal elasticity, or plasticity, is transformed into one of gradient nature. Different Taylor series expansion techniques are applied to the driving local strain fields of the nonlocal problem, either full spatial expansion within the bulk volume, or uni-directional expansion along the normal to the thin boundary layer. This, at the limit when the boundary layer thickness tends to zero, makes the PVP of the nonlocal model transform itself into one featuring a counterpart gradient model. Also, for a class of “associated” nonlocal and gradient elasticity models (i.e. the kerne…
Using an adaptive display for the treatment of emotional disorders
2006
A preliminary study on the use of an adaptive display for treating emotional disorders is presented. This adaptive display (named EMMA) varies the contents that are presented depending on the emotions of the user at each moment. The application has been designed to help in the treatment of Post-Traumatic Stress Disorder (PTSD) and Adjustment Disorder (AD). The specific objective of the present work is to test the effectiveness of this adaptive display, specifically the acceptance of the treatment by patients. EMMA's tools are compared with the standard of care for PTSD and AD. Results showed differences only for the variable aversiveness. Participants in the EMMA condition evaluated the tre…