1,720,959 research outputs found
FAST TEMPLATE MATCHING FOR UMTS CODE KEYS WITH GRAPHICS HARDWARE
No full textTemplate matching is a milestone application in Digital Signal Processing, and sets its roots in fundamental numeric filtering theory, as well as in time and frequency domain analysis. Radio signals, with mass spreading of high bandwidth cellular networks, have become in recent years much more critical to handle in terms of QoS (Quality of Service), QoE (Quality of Experience) and SLA (Service Level Agreement), putting mobile carriers in the need to monitor their network status in a more detailed and efficient way than in past. Here an efficient use case of GPU computing applied to fast signal processing will be illustrated, with particular interest in study and development of a SIMD Linear and FFT-based cross correlation of multiple code keys in air-captured streams for UMTS networks. Developed techniques have been used with success in a commercial available 3G geotagged scanning equipment.
Modelling a fast BLAS level-1 inspired vectorized FPU for ARM devices
No full textAbstract
Modern collections of algorithms for DSP and multimedia often rely on linear algebra operators to perform massive numerical transformations on vectorized data. Embedded developers often experience the worst condition of having no FPU at all in their low-power systems, as many device producers consider FP-math as an expensive option in terms of gates and power consumption. Main aim of this work is to propose a lightweight structure, designed to be used in an ARM-based environment but easily retargetable to different architectures, capable to perform efficiently vectorized FP operations as described in BLAS Level 1 specification. Peculiar feature is the capability of such a coprocessor to work in a fully pipelined mode. Both single and double precision calculations can be performed. Many different CPU offloading techniques have been implemented, in order to enable reactive power management policies during idle/waiting time slices. An implementation in VHDL is presented as result, showing synthesis and placement results in different technologies. FPGA+ARM9 prototype is presented and benchmarked. Results have been compared to functionally equivalent solutions running in different environments and using different sets of processing primitives (up to x86's SSE2/3/4). Finally, a complex application for Hidden Markov Model (HMM) training and evaluation is used as test case to evaluate real-world performance of the proposed approach
Algorithm and processor co-design for fast computation in real time HD motion estimation
No full textAbstract
High resolution video (720p, 1080i and 1080p frame sizes, up to 60 fps), even if widespread in prosumer/consumer markets, still represents an absolute challenge in the embedded and low power devices, especially due to the increasing complexity of compression schemes. H.264/AVC represents actual de facto standard for both excellent quality and low-bandwidth results. Motion estimation step (ME), for FullHD video, needs up to 80% time of the whole compression demands, if tuned to achieve optimal PSNR ratios. Simplest algorithms, often used to reduce the total computing time, don't meet the requirements in terms of final quality of motion prediction, while “early stopping” schemes suffer of local minima issues when not properly initialized. In this work we present a customizable solution for ME, tailored for SoC/MPSoC inclusion, able to perform different classes of search algorithms, reprogrammable from host CPU even when the coprocessor is encoding. Particular focus has been placed on the processing elements, designed to be easily reconfigured to implement different math and/or logical and/or routing operations. Phase oriented early stopping technique is proposed. Finally, the architecture designed in VHDL has been tested with the UMHEX algorithm for H.264 ME, as proof of concept. FPGA synthesis results are reported
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
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