Search results for " array"
showing 10 items of 895 documents
Development of a Fractional PI controller in an FPGA environment for a Robust High-Performance PMSM Electrical Drive
2021
This paper proposes the application of a Fractional Order PI (FOPI) in the speed loop of a high performance PMSM drive to obtain both speed tracking and load rejection performance with a 1-DOF Proportional Integral (PI) controller and 2-DOF Integral Proportional (IP) controller. Hardware validation was implemented in Field Programmable Gate Array on the LabVIEW environment, based on the National Instruments System-on-Module sbRIO-9651 with Xilinx Zynq-7020. Simulation and experimental results are presented to comparing the performance of a PI, IP and FOPI controllers in the speed loop of a Field Oriented Control (FOC) of a Permanent Magnet Synchronous Motor (PMSM).
MP2P Network in Collecting Data from Sensor Networks
2006
Wireless sensor networks provide numerous applications today. At the same time modern wireless short-range communication technologies combined with mobile users create environments for mobile peerto- peer networks. This paper discusses a concept of an application in which an MP2P network is used for collecting sensor network data. This model requires certain places with a high mobile user density in order to function. Simulation results indicate that the model can be used in environments where these requirements are met.
3D ERT for the study of an ancient wall covered by precious mosaics
2009
The DC electrical tomography (ERT) is still a method scarcely diffused for the study of masonry of recent and ancient buildings, in spite of the very high resolution power of this methodology. The major limitation on ERT applicability on precious surfaces (like masonries or floors with fresco or mosaic covering) depends on the method of current injection: usually it is necessary to drive electrodes (small nails) into small perforations on the surfaces, to obtain sufficiently high current values (to produce good signal to noise ratio). An interesting application of the MYG array (that reduces significantly, compared to other classical arrays, the number of electrodes utilized for current inj…
Light Curves of Radio Supernovae
2007
We present the results from the on-going radio monitoring of recent type II supernovae (SNe), including SNe 2004et, 2004dj, 2002hh, 2001em, and 2001gd. Using the Very Large Array to monitor these supernovae, we present their radio light-curves. From these data we are able to discuss parameterizations and modeling and make predictions of the nature of the progenitors based on previous research. Derived mass loss rates assume wind-established circumstellar medium, shock velocity ~10,000 km/s, wind velocity ~10 km/s, and CSM Temperature ~10,000 K.
Simultaneous radio and X-ray observations of the low-mass X-ray binary GX 13+1
2004
We present the results of two simultaneous X-ray/radio observations of the low-mass X-ray binary GX 13+1, performed in July/August 1999 with the Rossi X-ray Timing Explorer and the Very Large Array. In X-rays the source was observed in two distinct spectral states; a soft state, which had a corresponding 6 cm flux density of ~0.25 mJy, and a hard state, which was much brighter at 1.3-7.2 mJy. For the radio bright observation we measured a delay between changes in the X-ray spectral hardness and the radio brightness of ~40 minutes, similar to what has been found in the micro-quasar GRS 1915+105. We compare our results with those of GRS 1915+105 and the atoll/Z-type neutron star X-ray binarie…
Radio Emission from SN 2001gd in NGC 5033
2003
We present the results of monitoring the radio emission from the Type IIb supernova SN 2001gd between 2002 February 8 and 2002 October 28. Most of the data were obtained using the Very Large Array at the five wavelengths of $\lambda \lambda$1.3 cm (22.4 GHz), 2.0 cm (14.9 GHz), 3.6 cm (8.44 GHz), 6.2 cm (4.86 GHz), and 21 cm (1.4 GHz). Observations were also made with Giant Meterwave Radio Telescope at $\lambda$21 cm (1.4 GHz). The object was discovered optically well after maximum light, making any determination of the early radio evolution difficult. However, subsequent observations indicate that the radio emission has evolved regularly in both time and frequency and is well described by …
Fault Emulation for Dependability Evaluation of VLSI Systems
2008
Advances in semiconductor technologies are greatly increasing the likelihood of fault occurrence in deep-submicrometer manufactured VLSI systems. The dependability assessment of VLSI critical systems is a hot topic that requires further research. Field-programmable gate arrays (FPGAs) have been recently pro posed as a means for speeding-up the fault injection process in VLSI systems models (fault emulation) and for reducing the cost of fixing any error due to their applicability in the first steps of the development cycle. However, only a reduced set of fault models, mainly stuck-at and bit-flip, have been considered in fault emulation approaches. This paper describes the procedures to inje…
CIPRNG: A VLSI Family of Chaotic Iterations Post-Processings for $\mathbb {F}_{2}$ -Linear Pseudorandom Number Generation Based on Zynq MPSoC
2018
Hardware pseudorandom number generators are continuously improved to satisfy both physical and ubiquitous computing security system challenges. The main contribution of this paper is to propose two post-processing modules in hardware, to improve the randomness of linear PRNGs while succeeding in passing the TestU01 statistical battery of tests. They are based on chaotic iterations and are denoted by CIPRNG-MC and CIPRNG-XOR. They have various interesting properties, encompassing the ability to improve the statistical profile of the generators on which they iterate. Such post-processing have been implemented on FPGA and ASIC without inferring any blocs (RAM or DSP). A comparison in terms of …
Optimized FPGA-implementation of quadrature DDS
2003
This paper presents the optimized implementation of high performance quadrature direct digital synthesizers (DDS). Although VLSI designs and optimizations have already been discussed in the literature they may not be successfully translated into an FPGA-based technology. This work examines each phase-to-amplitude mapping technique, such as ROM compression and partitioning techniques and the CORDIC algorithm, and it proposes the most suitable structure for Virtex FPGAs in order to obtain the most efficient implementation in terms of area and throughput.
An Embedded Real-Time Lane-Keeper for Automatic Vehicle Driving
2008
Automatic vehicle driving involves several issues, such as the capability to follow the road and keep the right lane, to maintain the distance between vehicles, to regulate vehiclepsilas speed, to find the shortest route to a destination. In this paper a real-time automatic lane-keeper is proposed. The main features of the system are the lane markers location process as well as the computation of the vehiclepsilas steering lock. The above techniques require high elaboration speed to execute, check and complete an operation before a prearranged time. Clearly if system processing exceeds the deadline, the whole operation became meaningless or, in the meantime, the vehicle can reach a critical…