Search results for " Computer Science"
showing 10 items of 3983 documents
Deep Convolutional Neural Network Based Object Detection Inference Acceleration Using FPGA
2022
Object detection is one of the most challenging yet essential computer vision research areas. It means labeling and localizing all known objects of interest on an input image using tightly fit rectangular bounding boxes around the objects. Object detection, having passed through several evolutions and progressions, nowadays relies on the successes of image classification networks based on deep convolutional neural networks. However, as the depth and complication of convolutional neural networks increased, detection speed reduced, and accuracy increased. Unfortunately, most computer vision applications, such as real-time object tracking on an embedded system, requires lightweight, fast and a…
Hybrid CPU–GPU implementation of the transformed spatial domain channel estimation algorithm for mmWave MIMO systems
2022
Abstract Hybrid platforms combining multicore Central Processing Units (CPU) with many-core hardware accelerators such as Graphic Processing Units (GPU) can be smartly exploited to provide efficient parallel implementations of wireless communication algorithms for Fifth Generation (5G) and beyond systems. Massive Multiple-Input Multiple-Output (MIMO) systems are a key element of the 5G standard, involving several tens or hundreds of antenna elements for communication. Such a high number of antennas has a direct impact on the computational complexity of some MIMO signal processing algorithms. In this work, we focus on the channel estimation stage. In particular, we develop a parallel impleme…
SYSTOLIC GENERATION OF k-ARY TREES
1999
The only parallel generating algorithms for k-ary trees are those of Akl and Stojmenović in 1996 and of Vajnovszki and Phillips in 1997. In the first of them, trees are represented by an inversion table and the processor model is a linear aray multicomputer. In the second, trees are represented by bitstrings and the algorithm executes on a shared memory multiprocessor. In this paper we give a parallel generating algorithm for k-ary trees represented by generalized P–sequences for execution on a linear array multicomputer.
A Novel Systolic Parallel Hardware Architecture for the FPGA Acceleration of Feedforward Neural Networks
2019
New chips for machine learning applications appear, they are tuned for a specific topology, being efficient by using highly parallel designs at the cost of high power or large complex devices. However, the computational demands of deep neural networks require flexible and efficient hardware architectures able to fit different applications, neural network types, number of inputs, outputs, layers, and units in each layer, making the migration from software to hardware easy. This paper describes novel hardware implementing any feedforward neural network (FFNN): multilayer perceptron, autoencoder, and logistic regression. The architecture admits an arbitrary input and output number, units in la…
<title>Managing compressed multimedia data in a memory hierarchy: fundamental issues and basic solutions</title>
1998
The purpose of the work is to discuss the fundamental issues and solutions in managing compressed and uncompressed multimedia data, especially voluminous continuous mediatypes (video, audio) and text in a memory hierarchy with four levels (main memory, magnetic disk, (optical or magnetic) on-line/near-line low-speed memory, and slow off-line memory, i.e. archive). We view the multimedia data in such a database to be generated, (compressed), and stored into the memory hierarchy (at the lowest non-archiving level), and subsequently retrieved, (decompressed), and presented. If unused, the data either travels down in the memory hierarchy or it is compressed and stored at the same level. We firs…
Optimizing the Performance of Data Warehouse by Query Cache Mechanism
2022
Fast access of data from Data Warehouse (DW) is a need for today’s Business Intelligence (BI). In the era of Big Data, the cache is regarded as one of the most effective techniques to improve the performance of accessing data. DW has been widely used by several organizations to manage data and use it for Decision Support System (DSS). Many methods have been used to optimize the performance of fetching data from DW. Query cache method is one of those methods that play an effective role in optimization. The proposed work is based on a cache-based mechanism that helps DW in two aspects: the first one is to reduce the execution time by directly accessing records from cache memory, and th…
Simple method for limiting delay of optimized interleavers for turbo-codes
2000
An iterative interleaver growth algorithm is extended to allow the delay and required memory of designed interleavers to be halved with negligible performance loss. The original algorithm is efficient for two-component parallel concatenated turbo-codes with given constituent encoders that are optimum with regard to a cost function satisfying some mild conditions. However, it is only actually optimum if the selected set of patterns is representative of low-weight turbo-codewords. The new interleaver uses all terminating error patterns having an input weight not greater than a fixed IWX and single-coder output weight not greater than WX is proposed.
Synthetic individual binaural audio delivery by pinna image processing
2014
Purpose – The purpose of this paper is to present a system for customized binaural audio delivery based on the extraction of relevant features from a 2-D representation of the listener’s pinna. Design/methodology/approach – The most significant pinna contours are extracted by means of multi-flash imaging, and they provide values for the parameters of a structural head-related transfer function (HRTF) model. The HRTF model spatializes a given sound file according to the listener’s head orientation, tracked by sensor-equipped headphones, with respect to the virtual sound source. Findings – A preliminary localization test shows that the model is able to statically render the elevation of a vi…
Spectral Density Estimate for Stable Processes Observed with an Additive Error
2018
International audience; In this paper, a symmetric alpha stable process where its spectral representation has an additive error is considered. The error is supposed to be constant. A periodogram as estimator of the spectral density and its rate of convergence are given. In order to give an asymptotically unbiased and consistent estimate of the spectral density, this periodogram is smoothed by an adapted spectral window. The rate of convergence is given.
Numerical Solution of Foodstuff Freezing Problems Using Radial Basis Functions
2013
This work presents a novel numerical approach for the solution of time dependent non-linear freezing processes in terms of radial basis function Hermite approach. The proposed scheme is applied to a mashed potato sample during its freezing; evaluation of time evolution of the temperature profile at the core of the sample is carried out. Food thermal properties are highly dependent on temperature and the mathematical problem becomes highly non-linear and therefore particularly difficult to solve. Incorporating a Kirchhoff transformation significantly reduces the non-linearity. The robustness of the scheme is tested by comparison with experimental results available in literature.