Search results for "Frame"
showing 10 items of 1767 documents
A Synchronous Reference Frame Robust Predictive Current Control for Three-Phase Grid-Connected Inverters
2010
This paper presents a new predictive current control for three-phase grid-connected inverters in the synchronous reference frame. The control combines a deadbeat control law with a diagonal Luenberger observer to estimate the future value of the grid currents. It provides a decoupled control of the active and reactive power and offers robustness against the computational delay inherent in the digital implementation and against filter and grid-impedance uncertainties. This control exhibits a very fast current response while widely improving the gain and phase margins of the traditional predictive controllers.
Product Placement Bibliometric Study: Generic Journals Versus Specific-Communication Journals
2021
Media fragmentation represents new challenges for product placement strategies to become an increasingly effective way to reach consumers and non-users. In this frame, this paper has been developed with three main objectives: (i) to carry on a performance analysis to measure the visibility/impact of the scientific product in product placement (most cited authors, journals, and themes), (ii) to visually present the scientific structure by topics of research in product placement as well as its evolution to identify future research lines, and (iii) to compare both objectives in generic journals and specific communication ones. To this end, the resources in the Web of Science Citation Index wer…
Measuring the weather’s impact on MAC layer over 2.4GHz outdoor radio links
2015
The weather s impact on the performance of a radio link at the 2.4 GHz ISM (Industry, Scientific and Medical) band had not been yet studied in great detail up to now as it is generally believed that the ultra-high frequency band is not significantly affected by weather conditions. However, our study shows significant correlations between meteorological variables and control frame errors at MAC (Medium Access Control) layer of the IEEE 802.11b/g standard. This study is performed over an outdoor radio link setting which has been monitored for several months. Moreover, we check if link distance and so modulation scheme and data rate are also decisive features of such impact. Our real scenario …
Structural performances of pultruded GFRP emergency structures – Part 2: Full-scale experimental testing
2019
Abstract This paper presents an experimental testing of a pultruded glass fiber reinforced polymer (FRP) structure used for emergency applications continuing the discussion presented in a previous paper (part 1) where the study of the characteristics of material and elements are presented. First, the design of the composite structure and components and the evaluation of the structural behavior by means of numerical and analytical approach according to current regulatory codes are described. In this frame, the global and local response was observed according to load paths deriving from the design loads at limit states. Then, the experimental test on a full-scale 2D model is presented at diff…
Intertwining operators between different Hilbert spaces: connection with frames
2009
In this paper we generalize a strategy recently proposed by the author concerning intertwining operators. In particular we discuss the possibility of extending our previous results in such a way to construct (almost) isospectral self-adjoint operators living in different Hilbert spaces. Many examples are discussed in details. Many of them arise from the theory of frames in Hilbert spaces, others from the so-called g-frames.
Progress in EU Breeding Blanket design and integration
2018
Abstract In Europe (EU), in the frame of the EUROfusion consortium activities, four Breeding Blanket (BB) concepts are being developed with the aim of fulfilling the performances required by a near-term fusion power demonstration plant (DEMO) in terms of tritium self-sufficiency and electricity production. The four blanket options cover a wide range of technological possibilities, as water and helium are considered as possible coolants and solid ceramic breeder in combination with beryllium and PbLi as tritium breeder and neutron multipliers. The strategy for the BB selection and operation has to account for the challenging schedule of the EU DEMO, the ambitious operational requirements of …
Do Videogames Simulate? Virtuality and Imitation in the Philosophy of Simulation
2015
Simulation. The concept of simulation has been contested in academia since its proliferation in the 1960s. This is hardly the case in videogame research, the subject of which is commonly discussed as a simulation or something that simulates with little analytical consideration of the term’s other scientific roles. Comparison. The article compares the simulation of videogame research to the ways in which other scientific sectors utilize the term. Problematic science communication. It turns out that videogame research has found an eccentric use for simulation with none or little relation to the term’s scientific (knowledge-driven) and etymological (imitational) predecessors. This becomes a p…
An Embedded Real-Time Automatic Lane-Keeping System
2007
Advanced Driver Assistance Systems (ADAS) are safety systems capable of identifying an unavoidable dangerous scenario and reacting coherently. An automatic lane-keeping system is designed to prevent dangerous events when the driver left inadvertently his/her own lane. In this paper a real-time automatic lane-keeping system is proposed. The main features of the system are the lane markers location process as well as the generation of the vehicle's steering angle. The system has been prototyped using the Celoxica RC203 board, equipped with a Xilinx Virtex II FPGA, for real-time processing of real motorway scenes coming from a CCD camera on a moving vehicle. The required processing time is 25,…
Design of a Time Dissemination System Using Chirp Modulation for Medium Voltage Smart Grid Applications
2020
The monitoring and the management of smart grid require an advanced communication infrastructure. The time synchronization is among the most important services such an infrastructure should offer. Several solutions are available to disseminate the time information in a distributed system; for instance, most of the times a global positioning system (GPS) receiver is used to recover accurate time information. However, GPS receivers need a clear view of the sky. Other solutions, like the use of a network-based synchronization mechanism, require a dedicated communication infrastructure, which is not always feasible for economical reason. Thus, the use of the power grid itself to disseminate a t…
ErrorSense: Characterizing WiFi Error Patterns for Detecting ZigBee Interference
2014
Recent years have witnessed the increasing adoption of heterogeneous wireless networks working in unlicensed ISM bands, thus creating serious problems of spectrum overcrowding. Although ZigBee, Bluetooth and WiFi networks have been natively designed for working in presence of interference, it has been observed that several performance impairments may occur because of heterogeneous sensitivity to detect or react to the presence of other technologies. In this paper we focus on the WiFi capability to detect interfering ZigBee links. Despite of the narrowband transmissions performed by ZigBee, in emerging scenarios ZigBee interference can have a significant impact on WiFi performance. Therefore…