Search results for "Virtual"
showing 10 items of 1485 documents
The Virtual Reconstruction of the Aesculapius and Hygeia Statues from the Sanctuary of Isis in Lilybaeum: Methods and Tools for Ancient Sculptures’ E…
2022
Thanks to recent technological developments in 3D surveys, computer graphics and virtual reality, new scenarios have been opened for the documentation and enhancement of ancient sculptures. When not totally preserved, sculptures can be digitally reproduced, modified and visualized to simulate their physical or virtual reconstruction in a non-invasive way for specialists or for dissemination aims. The virtual sculptural reconstruction process starts usually from the 3D survey of real fragments, and then continues by integrating missing parts with 3D modelling techniques by means of source evaluation. Along with primary data sources (reality-based model), secondary data sources (photos, drawi…
Virtual Synchronous Machine Control of RES Plants in Isolated Power Systems
2022
Because of the increase in renewable energy sources (RESs) share, new control strategies of isolated power systems have been developed to improve the frequency and voltage stability of inverter-interfaced RESs. A voltage source converter (VSC) with a virtual synchronous machine (VSM) is among the most promising control schemes. This paper demonstrates how VSM control of inverter-interfaced RES can be efficiently used to improve the dynamic stability in small isolated power systems. In the proposed analysis, the RESs of a Mediterranean island are assumed interfaced to the grid by VSCs with a swing controller and a vector-current controller (VCC) with two different options for the reference c…
H-KPP : Hypervisor-Assisted Kernel Patch Protection
2022
We present H-KPP, hypervisor-based protection for kernel code and data structures. H-KPP prevents the execution of unauthorized code in kernel mode. In addition, H-KPP protects certain object fields from malicious modifications. H-KPP can protect modern kernels equipped with BPF facilities and loadable kernel modules. H-KPP does not require modifying or recompiling the kernel. Unlike many other systems, H-KPP is based on a thin hypervisor and includes a novel SLAT switching mechanism, which allows H-KPP to achieve very low (≈6%) performance overhead compared to baseline Linux.
Nanovised Control Flow Attestation
2022
This paper presents an improvement of control flow attestation (C-FLAT) for Linux. C-FLAT is a control attestation system for embedded devices. It was implemented as a software executing in ARM’s TrustZone on bare-metal devices. We extend the design and implementation of C-FLAT through the use of a type 2 Nanovisor in the Linux operating system. We call our improved system “C-FLAT Linux”. Compared to the original C-FLAT, C-FLAT Linux reduces processing overheads and is able to detect the SlowLoris attack. We describe the architecture of C-FLAT Linux and provide extensive measurements of its performance in benchmarks and real-world scenarios. In addition, we demonstrate the…
HyperIO: A Hypervisor-Based Framework for Secure IO
2023
Malware often attempts to steal input and output through human interface devices to obtain confidential information. We propose to use a thin hypervisor, called “HyperIO”, to realize a secure path between input and output devices using a partial implementation of device drivers. We apply our approach using two security systems built on HyperIO: FireSafe and ClipCrypt. FireSafe is a web browser extension which allows a remote web server to display and receive sensitive user information securely. ClipCrypt enables the user to securely enter and view their confidential information in commodity Windows applications.
A virtual laboratory designed for teaching diffractive lenses
2010
[EN] We present a virtual laboratory generated in Matlab GuiQc (Graphical User Interface) for its use in Optics courses as an informatic tool for teaching the focusing properties of a diffractive lens. This Gui allows the students to learn easily and rapidly about the influence on the focal volume of the lens construction parameters. As an example in this work we analyze fractal diffractive lenses because we found that fractal geometry is a highly motivating topic for students since it is related to a wide range of scientific and technological phenomena.
Guest Editorial: Advanced Motion Control for Mechatronic Applications With Precision and Force Requirements
2021
The articles in this special section focus on advanced motion control for mechatronic applications with precision and force requirements. Motion control is concerned with all the issues arising in the control of the movement of a physical device. This means that MC is not limited to the use of proper devices for sensing and actuation, in addition to suitable control algorithms, but it also deals with all the possible interactions of the controlled devices with the environment. This is the most remarkable aspect of MC, nowadays deployed in numerous mechatronic systems, especially those which are dynamically acting in heterogenous, time-varying, active, and human-accessible environments. With…
Virtual reality for driving simulation
1996
In this paper, the authors describe the data structure necessary to provide real time simulation and visualization of complex environments and situations. Through the SIRCA project, the development of driving oriented simulators, using Virtual Reality (VR) and evaluating it in comparison with convention technologies, has taken place. Focus is on some of the algorithms and data structure required to provide real time simulation of the complex urban environment and its visualization under the conditions of VR devices.
Optimization of Cultural Heritage Virtual Environments for Gaming Applications
2020
Serious games are games with a purpose beyond entertainment and are widely acknowledged as fruitful tools for learning and developing skills across multiple domains, including educational enhancement. In the last few years, the world of serious games has widely increased. The use of these types of games can aid in classrooms to not only help the students learn concepts but also to improve their motivation to do so. However, designing games necessitates very specialized personnel and the process can often be costly and slow. The adaptions of the design to the implantation phase are also difficult and the process needs more focus. The challenge of this study was to create a game within the co…
Computer-supported collaboration in a scripted 3-D game environment
2005
The particular focus of this paper is on scripting collaboration in a 3-D virtual game environment intended to make learning more effective, but also take into account the risk of over-scripting learning. The empirical experiment eScape, which encourages learners to solve problems collaboratively, is also presented. This study attempts to find out whether the features of 3-D games can be used to create meaningful scripted collaborative learning environments. The results indicated that scripting persuaded student teams to enter into collaboration, but the actual processes varied.