Conventional virtual coupling is designed mainly for stabilizing the virtual environment (VE) and it thus may have poor performances. This paper proposes a novel adaptive virtual coupling design approach for haptic display in passive or time-delayed non-passive virtual environment. According to the performance errors, the virtual coupling can be adaptively tuned through some fuzzy logic based l...

In this paper we deal with a scheduling algorithm that creates several virtual links on one physical link by switching the service between the virtual links. The switching is done in such a way that the physical link is available for each virtual link for a constant time, what provides full performance isolation between virtual links. Firstly, we present a detailed analysis of the scheduler, in...

Network virtualization allows cloud infrastructure providers to accommodate multiple virtual networks on a single physical network. However, mapping multiple virtual network resources to physical network components, called virtual network embedding (VNE), is known to be non-deterministic polynomial-time hard (NP-hard). Effective virtual network embedding increases the revenue by increasing the ...

In searching for methods to distinguish knots and links, recent work has focussed on the more general virtual knots and links, introduced by Kauffman in [2]. If we ignore the over/under information at each crossing, we obtain a flat virtual knot or link (still called a knot or a link), sometimes called the universe of the original virtual knot or link. It is a triviality that if the original vi...

background: the i-space is a radiological imaging system in which computed tomography (ct)-scans can be evaluated as a three dimensional hologram. the aim of this study is to analyze the value of virtual reality (i-space) in diagnosing acute occult scaphoid fractures.   methods: a convenient cohort of 24 patients with a ct-scan from prior studies, without a scaphoid fracture on radiograph, yet ...

the purpose of this study was to evaluate the rate of using standards of designing electronic courses in educational contents of state-virtual universities in iran. the method of the study was a descriptive-survey one. the statistical population was the educational content of electronic courses in state-virtual universities such as university of science and technology, and shiraz university. da...

Very few virtual environment design tools have been developed for non-programmers. Most non-programmers rely on programmers to produce their environments, or produce static environments using traditional geometrical modelers. Non-programmers, including artists and designers, have a lot to contribute to the development of virtual environments. In addition, tools developed to assist this user gro...