Search results for "Parallel"
showing 10 items of 667 documents
Film and digital periapical radiographs for the measurement of apical root shortening
2012
Objectives: The aim of this study was to compare the accuracy and agreement of scanned film and digital periapical radiographs for the measurement of apical root shortening. Study design: Twenty-four film and digital [phosphor plate sensor (PPS)] periapical radiographs were taken using the long-cone paralleling technique for six extracted teeth before and after 1mm of apical root trimming. All teeth were mounted using a typodont and the radiographs were recorded using a film holder and polysiloxane occlusal index for each tooth to ensure standardization during the different radiographic exposures. The film radiographs were scanned and the tooth length measurements for the scanned film and d…
Testing Taxonomic and Biogeographical Relationships in a Narrow Mediterranean Endemic Complex (Hippocrepis balearica) using RAPD Markers
2002
Analyses of RAPD profiles from 17 populations of the Hippocrepis balearica complex revealed a highly structured geographic pattern, not only among continental–insular areas but also within the eastern Balearic islands. In marked contrast to previous morphometric results, a clear separation between continental and insular samples was found, and intermediates between H. balearica and H. valentina samples were not detected. Molecular data indicated that western and eastern Balearic populations of the complex (H. grosii and H. balearica) were more closely related to each other than to continental populations (H. valentina). Multivariate analyses of the RAPD data clearly indicated that the simil…
A block access unit for 2D memory access
2007
Many of the coding tools in the H.264/AVC video coding standard are based on 2D processing resulting in rowwise and column-wise memory accesses starting from arbitrary memory addresses. This paper discusses a low-cost hardware realization of these accesses on sub-word parallel processors. The proposed block access unit is placed between the processor and memory. It supports unaligned 2D block accesses according to several 2D access patterns. The 2D block accesses are pipelinable and they result in minimum number of memory accesses required to deliver the desired data.
Analyzing the Energy Efficiency of the Memory Subsystem in Multicore Processors
2014
In this paper we analyze the energy overhead incurred when operating with data stored in different levels of the memory subsystem (cache levels and DDR chips) of current multicore architectures. Our approach builds upon servet, a portable framework for the memory characterization of multicore processors, extending this suite with a power-related test that, when applied to a platform equipped with a power measurement mechanism, provides information on the efficiency of memory energy usage. As additional contributions, i) we provide a complete experimental study of the impact that the CPU performance states (also known as P-states) exert on the memory energy efficiency of a collection of rece…
HECTOR : a parallel multistage homopolymer spectrum based error corrector for 454 sequencing data
2014
Background Current-generation sequencing technologies are able to produce low-cost, high-throughput reads. However, the produced reads are imperfect and may contain various sequencing errors. Although many error correction methods have been developed in recent years, none explicitly targets homopolymer-length errors in the 454 sequencing reads. Results We present HECTOR, a parallel multistage homopolymer spectrum based error corrector for 454 sequencing data. In this algorithm, for the first time we have investigated a novel homopolymer spectrum based approach to handle homopolymer insertions or deletions, which are the dominant sequencing errors in 454 pyrosequencing reads. We have evaluat…
Multithreaded Peripheral Processor for a Multicore Embedded System
2012
Multithreaded and multicore architectures represent a good solution used for increasing of parallelism degree exploited in modern computing systems and they can reduce the power dissipated in the chip by using low-frequency clock signals. These advantages recommend these parallel architectures for integration in the embedded systems, with restrictions imposed by the relatively small integration area. Particularities of embedded applications require hardware support able to handling in real time the peripheral interrupt requests. The performance of this hardware influences the performance of the entire parallel system. The current trend is to integrate in one microcontroller more processors …
Towards a Formal Analysis of MQtt Protocol in the Context of Communicating Vehicles
2017
International audience; The paper presents a formal approach to model, analyze, and verify a variant of Message Queue Telemetry Transport protocol (MQtt), dedicated to communicating vehicles (MQtt-CV) that send collected data to automotive infrastructures(subscribers). Our formal approach is based on Promela language and its system verification tool, the model checker SPIN. We propose a slight modification of MQtt protocol to reduce the big volume of data collected and sent by vehicles to infrastructures. Indeed, in the original version of MQtt protocol, when a broker receives data from publishers, it sends them directly to its subscribers without any filtration. As consequence, subscribers…
High-resolution solution NMR structure of the Z domain of staphylococcal protein A
1997
Staphylococcal protein A (SpA) is a cell-wall-bound pathogenicity factor from the bacterium Staphylococcus aureus. Because of their small size and immunoglobulin (IgG)-binding activities, domains of protein A are targets for protein engineering efforts and for the development of computational approaches for de novo protein folding. The NMR solution structure of an engineered IgG-binding domain of SpA, the Z domain (an analog of the B domain of SpA), has been determined by simulated annealing with restrained molecular dynamics on the basis of 671 conformational constraints. The Z domain contains three well-defined alpha-helices corresponding to polypeptide segments Lys7 to Leu17 (helix 1), G…
Conformational and structural analysis of the equilibrium between single- and double-strand ?-helix of aD,L-alternating oligonorleucine
2004
Alternating sequences of D and L residues in peptides are directly related to the formation of several kinds of regular helical conformations usually called beta-helices. The major feature of these structures is that they can be associated with the transmembrane ion-conducting channel activity in some natural antibacterial peptides. The study of alternating D,L synthetic peptides is critical to understand how factors such as surrounding media, main chain length, type of side chain and terminal groups, among others, can determine the adoption of a specific kind of beta-helix. Early studies pointed out that the peptides Boc-(D-NLeu-L-NLeu)(6)-D-MeNLe-L-Nl-D-Nl-L-Nl-OMe (Boc: tert-butyloxycarb…
Solution structure of aD,L-alternating oligonorleucine as a model of double-stranded antiparallel ?-helix
2002
Conformational characteristics of alternating D,L linear peptides are of particular interest because of their capacity to form transmembrane channels with different transport properties, as some natural antibiotics do. Single- and double-stranded beta-helical structures are common for alternating D,L peptides. The stability of the beta-helix depends on several structural factors, such as the backbone peptide length, type and position of side chains, and nature of terminal groups. The NMR and molecular dynamics solution conformation of a synthetic alternating D,L-oligopeptide with 15 norleucines (XVMe) has been used as a model to get insight in to the conformational features of double-strand…