54 research outputs found

    Efficient Human Facial Pose Estimation

    Get PDF
    Pose estimation has become an increasingly important area in computer vision and more specifically in human facial recognition and activity recognition for surveillance applications. Pose estimation is a process by which the rotation, pitch, or yaw of a human head is determined. Numerous methods already exist which can determine the angular change of a face, however, these methods vary in accuracy and their computational requirements tend to be too high for real-time applications. The objective of this thesis is to develop a method for pose estimation, which is computationally efficient, while still maintaining a reasonable degree of accuracy. In this thesis, a feature-based method is presented to determine the yaw angle of a human facial pose using a combination of artificial neural networks and template matching. The artificial neural networks are used for the feature detection portion of the algorithm along with skin detection and other image enhancement algorithms. The first head model, referred to as the Frontal Position Model, determines the pose of the face using two eyes and the mouth. The second model, referred to as the Side Position Model, is used when only one eye can be viewed and determines pose based on a single eye, the nose tip, and the mouth. The two models are presented to demonstrate the position change of facial features due to pose and to provide the means to determine the pose as these features change from the frontal position. The effectiveness of this pose estimation method is examined by looking at both the manual and automatic feature detection methods. Analysis is further performed on how errors in feature detection affect the resulting pose determination. The method resulted in the detection of facial pose from 30 to -30 degrees with an average error of 4.28 degrees for the Frontal Position Model and 5.79 degrees for the Side Position Model with correct feature detection. The Intel(R) Streaming SIMD Extensions (SSE) technology was employed to enhance the performance of floating point operations. The neural networks used in the feature detection process require a large amount of floating point calculations, due to the computation of the image data with weights and biases. With SSE optimization the algorithm becomes suitable for processing images in a real-time environment. The method is capable of determining features and estimating the pose at a rate of seven frames per second on a 1.8 GHz Pentium 4 computer

    Comparisons between Chemical Mapping and Binding to Isoenergetic Oligonucleotide Microarrays Reveal Unexpected Patterns of Binding to the Bacillus subtilis RNase P RNA Specificity Domain†

    Get PDF
    ABSTRACT: Microarrays with isoenergetic pentamer and hexamer 20-O-methyl oligonucleotide probes with LNA (locked nucleic acid) and 2,6-diaminopurine substitutions were used to probe the binding sites on theRNase P RNA specificity domain of Bacillus subtilis. Unexpected binding patterns were revealed. Because of their enhanced binding free energies, isoenergetic probes can break short duplexes, merge adjacent loops, and/or induce refolding. This suggests new approaches to the rational design of short oligonucleotide therapeutics but limits the utility of microarrays for providing constraints for RNA structure determination. The microarray results are compared to results from chemical mapping experiments, which do provide constraints. Results from both types of experiments indicate that the RNase P RNA folds similarly in 1MNaĂŸ and 10 mMMg2ĂŸ. Binding of RNA to RNA is important for many natural func-tions, includingproteinsynthesis (1,2), translationregulation (3,4), gene silencing (5, 6), metabolic regulation (7), RNAmodification (8, 9), etc. (10-13). Binding of oligonucleotides toRNAs is impor-tant for therapeutic approaches, such as siRNA, ribozymes, and antisense therapy (14, 15).Much remains to bediscovered, however, of the rules for predicting binding sites andpotential therapeutics

    Letter of intent for KM3NeT 2.0

    Get PDF
    The main objectives of the KM3NeT Collaboration are ( i ) the discovery and subsequent observation of high-energy neutrino sources in the Universe and ( ii ) the determination of the mass hierarchy of neutrinos. These objectives are strongly motivated by two recent important discoveries, namely: ( 1 ) the high- energy astrophysical neutrino signal reported by IceCube and ( 2 ) the sizable contribution of electron neutrinos to the third neutrino mass eigenstate as reported by Daya Bay, Reno and others. To meet these objectives, the KM3NeT Collaboration plans to build a new Research Infrastructure con- sisting of a network of deep-sea neutrino telescopes in the Mediterranean Sea. A phased and distributed implementation is pursued which maximises the access to regional funds, the availability of human resources and the syner- gistic opportunities for the Earth and sea sciences community. Three suitable deep-sea sites are selected, namely off-shore Toulon ( France ) , Capo Passero ( Sicily, Italy ) and Pylos ( Peloponnese, Greece ) . The infrastructure will consist of three so-called building blocks. A building block comprises 115 strings, each string comprises 18 optical modules and each optical module comprises 31 photo-multiplier tubes. Each building block thus constitutes a three- dimensional array of photo sensors that can be used to detect the Cherenkov light produced by relativistic particles emerging from neutrino interactions. Two building blocks will be sparsely con fi gured to fully explore the IceCube signal with similar instrumented volume, different methodology, improved resolution and complementary fi eld of view, including the galactic plane. One building block will be densely con fi gured to precisely measure atmospheric neutrino oscillations. Original content from this work may be used under the ter

    Letter of intent for KM3NeT 2.0

    Get PDF

    Seismic velocity anomalies beneath SE Brazil from and wave travel time inversions

    No full text
    We present the result from teleseismic travel time inversions for P and S wave data mainly recorded at portable broadband stations in SE Brazil. The stations were deployed at 45 sites within an area 1000 × 1700 km during the years 1992–1999. More than 10,000 relative P and S wave arrival times, including core phases, were obtained from the waveforms using a new coherence functional. These P and S relative phase times are independently inverted for slowness perturbations, earthquake relocations, and station corrections. The final models represent the least amount of structure required to explain the residuals within a defined standard error. The robust and consistent features in the velocity anomaly models are interpreted and their resolution is tested with synthetic case inversions. We confirm the existence of a cylindrical low-velocity anomaly beneath the Paraná basin, which has been interpreted by VanDecar et al. [1995] as the fossil conduit through which the initial Tristan da Cunha plume head traveled to generate the Paraná–Etendeka flood basalts about 130 Ma. We now show that this low-velocity cylindrical structure seems to be confined to the upper mantle. Beneath the upper mantle, the velocity anomalies show a N-S oriented pattern, which we interpret as due to the Nazca plate subducted slab. At lithospheric depths, the Archean, southern part of the São Francisco craton, shows high velocities down to 200–300 km. All areas with Late Cretaceous postrift alkaline intrusions are characterized by low velocities at lithospheric depths.Peer reviewe
    • 

    corecore