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Sample records for fast tracking algorithm

  1. Study of hardware implementations of fast tracking algorithms

    NASA Astrophysics Data System (ADS)

    Song, Z.; De Lentdecker, G.; Dong, J.; Huang, G.; Léonard, A.; Robert, F.; Wang, D.; Yang, Y.

    2017-02-01

    Real-time track reconstruction at high event rates is a major challenge for future experiments in high energy physics. To perform pattern-recognition and track fitting, artificial retina or Hough transformation methods have been introduced in the field which have to be implemented in FPGA firmware. In this note we report on a case study of a possible FPGA hardware implementation approach of the retina algorithm based on a Floating-Point core. Detailed measurements with this algorithm are investigated. Retina performance and capabilities of the FPGA are discussed along with perspectives for further optimization and applications.

  2. A fast algorithm for muon track reconstruction and its application to the ANTARES neutrino telescope

    NASA Astrophysics Data System (ADS)

    Aguilar, J. A.; Al Samarai, I.; Albert, A.; André, M.; Anghinolfi, M.; Anton, G.; Anvar, S.; Ardid, M.; Assis Jesus, A. C.; Astraatmadja, T.; Aubert, J.-J.; Auer, R.; Baret, B.; Basa, S.; Bazzotti, M.; Bertin, V.; Biagi, S.; Bigongiari, C.; Bogazzi, C.; Bou-Cabo, M.; Bouwhuis, M. C.; Brown, A. M.; Brunner, J.; Busto, J.; Camarena, F.; Capone, A.; Cârloganu, C.; Carminati, G.; Carr, J.; Cecchini, S.; Charvis, Ph.; Chiarusi, T.; Circella, M.; Coniglione, R.; Costantini, H.; Cottini, N.; Coyle, P.; Curtil, C.; Decowski, M. P.; Dekeyser, I.; Deschamps, A.; Distefano, C.; Donzaud, C.; Dornic, D.; Dorosti, Q.; Drouhin, D.; Eberl, T.; Emanuele, U.; Ernenwein, J.-P.; Escoffier, S.; Fehr, F.; Flaminio, V.; Fritsch, U.; Fuda, J.-L.; Galatà, S.; Gay, P.; Giacomelli, G.; Gómez-González, J. P.; Graf, K.; Guillard, G.; Halladjian, G.; Hallewell, G.; van Haren, H.; Heijboer, A. J.; Hello, Y.; Hernández-Rey, J. J.; Herold, B.; Hößl, J.; Hsu, C. C.; de Jong, M.; Kadler, M.; Kalantar-Nayestanaki, N.; Kalekin, O.; Kappes, A.; Katz, U.; Kooijman, P.; Kopper, C.; Kouchner, A.; Kulikovskiy, V.; Lahmann, R.; Lamare, P.; Larosa, G.; Lefèvre, D.; Lim, G.; Lo Presti, D.; Loehner, H.; Loucatos, S.; Lucarelli, F.; Mangano, S.; Marcelin, M.; Margiotta, A.; Martinez-Mora, J. A.; Mazure, A.; Meli, A.; Montaruli, T.; Morganti, M.; Moscoso, L.; Motz, H.; Naumann, C.; Neff, M.; Palioselitis, D.; Păvălaş, G. E.; Payre, P.; Petrovic, J.; Picot-Clemente, N.; Picq, C.; Popa, V.; Pradier, T.; Presani, E.; Racca, C.; Reed, C.; Riccobene, G.; Richardt, C.; Richter, R.; Rostovtsev, A.; Rujoiu, M.; Russo, G. V.; Salesa, F.; Sapienza, P.; Schöck, F.; Schuller, J.-P.; Shanidze, R.; Simeone, F.; Spiess, A.; Spurio, M.; Steijger, J. J. M.; Stolarczyk, Th.; Taiuti, M.; Tamburini, C.; Tasca, L.; Toscano, S.; Vallage, B.; Van Elewyck, V.; Vannoni, G.; Vecchi, M.; Vernin, P.; Wijnker, G.; de Wolf, E.; Yepes, H.; Zaborov, D.; Zornoza, J. D.; Zúñiga, J.

    2011-04-01

    An algorithm is presented, that provides a fast and robust reconstruction of neutrino induced upward-going muons and a discrimination of these events from downward-going atmospheric muon background in data collected by the ANTARES neutrino telescope. The algorithm consists of a hit merging and hit selection procedure followed by fitting steps for a track hypothesis and a point-like light source. It is particularly well-suited for real time applications such as online monitoring and fast triggering of optical follow-up observations for multi-messenger studies. The performance of the algorithm is evaluated with Monte Carlo simulations and various distributions are compared with that obtained in ANTARES data.

  3. Fast tracking hospital construction.

    PubMed

    Quirk, Andrew

    2013-03-01

    Hospital leaders should consider four factors in determining whether to fast track a hospital construction project: Expectations of project length, quality, and cost. Whether decisions can be made quickly as issues arise. Their own time commitment to the project, as well as that of architects, engineers, construction managers, and others. The extent to which they are willing to share with the design and construction teams how and why decisions are being made.

  4. Fast Track Study

    NASA Technical Reports Server (NTRS)

    1996-01-01

    The NASA Fast Track Study supports the efforts of a Special Study Group (SSG) made up of members of the Advanced Project Management Class number 23 (APM-23) that met at the Wallops Island Management Education Center from April 28 - May 8, 1996. Members of the Class expressed interest to Mr. Vem Weyers in having an input to the NASA Policy Document (NPD) 7120.4, that will replace NASA Management Institute (NMI) 7120.4, and the NASA Program/Project Management Guide. The APM-23 SSG was tasked with assisting in development of NASA policy on managing Fast Track Projects, defined as small projects under $150 million and completed within three years. 'Me approach of the APM-23 SSG was to gather data on successful projects working in a 'Better, Faster, Cheaper' environment, within and outside of NASA and develop the Fast Track Project section of the NASA Program/Project Management Guide. Fourteen interviews and four other data gathering efforts were conducted by the SSG, and 16 were conducted by Strategic Resources, Inc. (SRI), including five interviews at the Jet Propulsion Laboratory (JPL) and one at the Applied Physics Laboratory (APL). The interviews were compiled and analyzed for techniques and approaches commonly used to meet severe cost and schedule constraints.

  5. A fast meteor detection algorithm

    NASA Astrophysics Data System (ADS)

    Gural, P.

    2016-01-01

    A low latency meteor detection algorithm for use with fast steering mirrors had been previously developed to track and telescopically follow meteors in real-time (Gural, 2007). It has been rewritten as a generic clustering and tracking software module for meteor detection that meets both the demanding throughput requirements of a Raspberry Pi while also maintaining a high probability of detection. The software interface is generalized to work with various forms of front-end video pre-processing approaches and provides a rich product set of parameterized line detection metrics. Discussion will include the Maximum Temporal Pixel (MTP) compression technique as a fast thresholding option for feeding the detection module, the detection algorithm trade for maximum processing throughput, details on the clustering and tracking methodology, processing products, performance metrics, and a general interface description.

  6. Large scale tracking algorithms

    SciTech Connect

    Hansen, Ross L.; Love, Joshua Alan; Melgaard, David Kennett; Karelitz, David B.; Pitts, Todd Alan; Zollweg, Joshua David; Anderson, Dylan Z.; Nandy, Prabal; Whitlow, Gary L.; Bender, Daniel A.; Byrne, Raymond Harry

    2015-01-01

    Low signal-to-noise data processing algorithms for improved detection, tracking, discrimination and situational threat assessment are a key research challenge. As sensor technologies progress, the number of pixels will increase signi cantly. This will result in increased resolution, which could improve object discrimination, but unfortunately, will also result in a significant increase in the number of potential targets to track. Many tracking techniques, like multi-hypothesis trackers, suffer from a combinatorial explosion as the number of potential targets increase. As the resolution increases, the phenomenology applied towards detection algorithms also changes. For low resolution sensors, "blob" tracking is the norm. For higher resolution data, additional information may be employed in the detection and classfication steps. The most challenging scenarios are those where the targets cannot be fully resolved, yet must be tracked and distinguished for neighboring closely spaced objects. Tracking vehicles in an urban environment is an example of such a challenging scenario. This report evaluates several potential tracking algorithms for large-scale tracking in an urban environment.

  7. Fast-Tracking Colostomy Closures.

    PubMed

    Nanavati, Aditya J; Prabhakar, Subramaniam

    2015-12-01

    There have been very few studies on applying fast-track principles to colostomy closures. We believe that outcome may be significantly improved with multimodal interventions in the peri-operative care of patients undergoing this procedure. A retrospective study was carried out comparing patients who had undergone colostomy closures by the fast-track and traditional care protocols at our centre. We intended to analyse peri-operative period and recovery in colostomy closures to confirm that fast-track surgery principles improved outcomes. Twenty-six patients in the fast-track arm and 24 patients in the traditional care arm had undergone colostomy closures. Both groups were comparable in terms of their baseline parameters. Patients in the fast-track group were ambulatory and accepted oral feeding earlier. There was a significant reduction in the duration of stay (4.73 ± 1.43 days vs. 7.21 ± 1.38 days, p = 0.0000). We did not observe a rise in complications or 30-day re-admissions. Fast-track surgery can safely be applied to colostomy closures. It shows earlier ambulation and reduction in length of hospital stay.

  8. TrackEye tracking algorithm characterization

    NASA Astrophysics Data System (ADS)

    Valley, Michael T.; Shields, Robert W.; Reed, Jack M.

    2004-10-01

    TrackEye is a film digitization and target tracking system that offers the potential for quantitatively measuring the dynamic state variables (e.g., absolute and relative position, orientation, linear and angular velocity/acceleration, spin rate, trajectory, angle of attack, etc.) for moving objects using captured single or dual view image sequences. At the heart of the system is a set of tracking algorithms that automatically find and quantify the location of user selected image details such as natural test article features or passive fiducials that have been applied to cooperative test articles. This image position data is converted into real world coordinates and rates with user specified information such as the image scale and frame rate. Though tracking methods such as correlation algorithms are typically robust by nature, the accuracy and suitability of each TrackEye tracking algorithm is in general unknown even under good imaging conditions. The challenges of optimal algorithm selection and algorithm performance/measurement uncertainty are even more significant for long range tracking of high-speed targets where temporally varying atmospheric effects degrade the imagery. This paper will present the preliminary results from a controlled test sequence used to characterize the performance of the TrackEye tracking algorithm suite.

  9. TrackEye tracking algorithm characterization.

    SciTech Connect

    Reed, Jack W.; Shields, Rob W; Valley, Michael T.

    2004-08-01

    TrackEye is a film digitization and target tracking system that offers the potential for quantitatively measuring the dynamic state variables (e.g., absolute and relative position, orientation, linear and angular velocity/acceleration, spin rate, trajectory, angle of attack, etc.) for moving objects using captured single or dual view image sequences. At the heart of the system is a set of tracking algorithms that automatically find and quantify the location of user selected image details such as natural test article features or passive fiducials that have been applied to cooperative test articles. This image position data is converted into real world coordinates and rates with user specified information such as the image scale and frame rate. Though tracking methods such as correlation algorithms are typically robust by nature, the accuracy and suitability of each TrackEye tracking algorithm is in general unknown even under good imaging conditions. The challenges of optimal algorithm selection and algorithm performance/measurement uncertainty are even more significant for long range tracking of high-speed targets where temporally varying atmospheric effects degrade the imagery. This paper will present the preliminary results from a controlled test sequence used to characterize the performance of the TrackEye tracking algorithm suite.

  10. FATRAS - the ATLAS Fast Track Simulation project

    NASA Astrophysics Data System (ADS)

    Mechnich, Jörg; ATLAS Collaboration

    2011-12-01

    The Monte Carlo simulation of the detector response is an integral component of any analysis performed with data from the LHC experiments. As these simulated data sets must be both large and precise, their production is a CPU-intensive task. ATLAS has developed full and fast detector simulation techniques to achieve this goal within the computing limits of the collaboration. At the current early stages of data-taking, it is necessary to reprocess the Monte Carlo event samples continuously, while integrating adaptations to the simulation modules in order to improve the agreement with data taken by means of the detector itself. FATRAS is a fast track simulation engine which produces a Monte Carlo simulation based on modules and the geometry of the standard ATLAS track reconstruction algorithm. It can be combined with a fast parametrized-response simulation of the calorimeters. This approach shows a high level of agreement with the full simulation, while achieving a relative timing gain of two orders of magnitude. FATRAS was designed to provide a fast feedback cycle for tuning the MC simulation with real data: this includes the material distribution inside the detector, the integration of misalignment and current conditions, as well as calibration at the hit level. We present the updated and calibrated version of FATRAS based on the first LHC data. Extensive comparisons of the fast track simulation with the full simulation and data at 900 GeV are shown.

  11. Fast track to 340B.

    PubMed

    Gricius, Robert F; Wong, Douglas

    2016-01-01

    Hospitals that are newly qualified for the 340B Drug Pricing Program may have an opportunity for fast-track approval to participate in the program. Three steps are required to seize this opportunity: Use data analytics to assess current and future percentages of Medicaid utilization and eligibility for federal SSI cash benefits. Determine the feasibility of early cost report filing. Prepare appropriate documentation and undertake the initial enrollment process.

  12. The Physics of Fast Track

    ERIC Educational Resources Information Center

    Kibble, Bob

    2007-01-01

    Toys can provide motivational contexts for learning and teaching about physics. A cheap car track provides an almost frictionless environment from which a quantitative study of conservation of energy and circular motion can be made.

  13. Math on the Fast Track

    ERIC Educational Resources Information Center

    Howe, Quincy

    2006-01-01

    In this article, the author relates how a math-assessment software has allowed his school to track the academic progress of its students. The author relates that in the first year that the software was deployed, schoolwide averages in terms of national standing on the math ITBS rose from the 42nd to 59th percentile. In addition, a significant…

  14. A Probabilistic Cell Tracking Algorithm

    NASA Astrophysics Data System (ADS)

    Steinacker, Reinhold; Mayer, Dieter; Leiding, Tina; Lexer, Annemarie; Umdasch, Sarah

    2013-04-01

    The research described below was carried out during the EU-Project Lolight - development of a low cost, novel and accurate lightning mapping and thunderstorm (supercell) tracking system. The Project aims to develop a small-scale tracking method to determine and nowcast characteristic trajectories and velocities of convective cells and cell complexes. The results of the algorithm will provide a higher accuracy than current locating systems distributed on a coarse scale. Input data for the developed algorithm are two temporally separated lightning density fields. Additionally a Monte Carlo method minimizing a cost function is utilizied which leads to a probabilistic forecast for the movement of thunderstorm cells. In the first step the correlation coefficients between the first and the second density field are computed. Hence, the first field is shifted by all shifting vectors which are physically allowed. The maximum length of each vector is determined by the maximum possible speed of thunderstorm cells and the difference in time for both density fields. To eliminate ambiguities in determination of directions and velocities, the so called Random Walker of the Monte Carlo process is used. Using this method a grid point is selected at random. Moreover, one vector out of all predefined shifting vectors is suggested - also at random but with a probability that is related to the correlation coefficient. If this exchange of shifting vectors reduces the cost function, the new direction and velocity are accepted. Otherwise it is discarded. This process is repeated until the change of cost functions falls below a defined threshold. The Monte Carlo run gives information about the percentage of accepted shifting vectors for all grid points. In the course of the forecast, amplifications of cell density are permitted. For this purpose, intensity changes between the investigated areas of both density fields are taken into account. Knowing the direction and speed of thunderstorm

  15. Accelerated Leadership Development: Fast Tracking School Leaders

    ERIC Educational Resources Information Center

    Earley, Peter; Jones, Jeff

    2010-01-01

    "Accelerated Leadership Development" captures and communicates the lessons learned from successful fast-track leadership programmes in the private and public sector, and provides a model which schools can follow and customize as they plan their own leadership development strategies. As large numbers of headteachers and other senior staff…

  16. Sequential algorithm for fast clique percolation.

    PubMed

    Kumpula, Jussi M; Kivelä, Mikko; Kaski, Kimmo; Saramäki, Jari

    2008-08-01

    In complex network research clique percolation, introduced by Palla, Derényi, and Vicsek [Nature (London) 435, 814 (2005)], is a deterministic community detection method which allows for overlapping communities and is purely based on local topological properties of a network. Here we present a sequential clique percolation algorithm (SCP) to do fast community detection in weighted and unweighted networks, for cliques of a chosen size. This method is based on sequentially inserting the constituent links to the network and simultaneously keeping track of the emerging community structure. Unlike existing algorithms, the SCP method allows for detecting k -clique communities at multiple weight thresholds in a single run, and can simultaneously produce a dendrogram representation of hierarchical community structure. In sparse weighted networks, the SCP algorithm can also be used for implementing the weighted clique percolation method recently introduced by Farkas [New J. Phys. 9, 180 (2007)]. The computational time of the SCP algorithm scales linearly with the number of k -cliques in the network. As an example, the method is applied to a product association network, revealing its nested community structure.

  17. A Reliability-Based Track Fusion Algorithm

    PubMed Central

    Xu, Li; Pan, Liqiang; Jin, Shuilin; Liu, Haibo; Yin, Guisheng

    2015-01-01

    The common track fusion algorithms in multi-sensor systems have some defects, such as serious imbalances between accuracy and computational cost, the same treatment of all the sensor information regardless of their quality, high fusion errors at inflection points. To address these defects, a track fusion algorithm based on the reliability (TFR) is presented in multi-sensor and multi-target environments. To improve the information quality, outliers in the local tracks are eliminated at first. Then the reliability of local tracks is calculated, and the local tracks with high reliability are chosen for the state estimation fusion. In contrast to the existing methods, TFR reduces high fusion errors at the inflection points of system tracks, and obtains a high accuracy with less computational cost. Simulation results verify the effectiveness and the superiority of the algorithm in dense sensor environments. PMID:25950174

  18. 40 CFR 72.82 - Fast-track modifications.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 16 2010-07-01 2010-07-01 false Fast-track modifications. 72.82... (CONTINUED) PERMITS REGULATION Permit Revisions § 72.82 Fast-track modifications. The following procedures shall apply to all fast-track modifications. (a) If the Administrator is the permitting authority,...

  19. 40 CFR 72.82 - Fast-track modifications.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 16 2011-07-01 2011-07-01 false Fast-track modifications. 72.82... (CONTINUED) PERMITS REGULATION Permit Revisions § 72.82 Fast-track modifications. The following procedures shall apply to all fast-track modifications. (a) If the Administrator is the permitting authority,...

  20. UWB Tracking Algorithms: AOA and TDOA

    NASA Technical Reports Server (NTRS)

    Ni, Jianjun David; Arndt, D.; Ngo, P.; Gross, J.; Refford, Melinda

    2006-01-01

    Ultra-Wideband (UWB) tracking prototype systems are currently under development at NASA Johnson Space Center for various applications on space exploration. For long range applications, a two-cluster Angle of Arrival (AOA) tracking method is employed for implementation of the tracking system; for close-in applications, a Time Difference of Arrival (TDOA) positioning methodology is exploited. Both AOA and TDOA are chosen to utilize the achievable fine time resolution of UWB signals. This talk presents a brief introduction to AOA and TDOA methodologies. The theoretical analysis of these two algorithms reveal the affecting parameters impact on the tracking resolution. For the AOA algorithm, simulations show that a tracking resolution less than 0.5% of the range can be achieved with the current achievable time resolution of UWB signals. For the TDOA algorithm used in close-in applications, simulations show that the (sub-inch) high tracking resolution is achieved with a chosen tracking baseline configuration. The analytical and simulated results provide insightful guidance for the UWB tracking system design.

  1. Fast autodidactic adaptive equalization algorithms

    NASA Astrophysics Data System (ADS)

    Hilal, Katia

    Autodidactic equalization by adaptive filtering is addressed in a mobile radio communication context. A general method, using an adaptive stochastic gradient Bussgang type algorithm, to deduce two low cost computation algorithms is given: one equivalent to the initial algorithm and the other having improved convergence properties thanks to a block criteria minimization. Two start algorithms are reworked: the Godard algorithm and the decision controlled algorithm. Using a normalization procedure, and block normalization, the performances are improved, and their common points are evaluated. These common points are used to propose an algorithm retaining the advantages of the two initial algorithms. This thus inherits the robustness of the Godard algorithm and the precision and phase correction of the decision control algorithm. The work is completed by a study of the stable states of Bussgang type algorithms and of the stability of the Godard algorithms, initial and normalized. The simulation of these algorithms, carried out in a mobile radio communications context, and under severe conditions on the propagation channel, gave a 75% reduction in the number of samples required for the processing in relation with the initial algorithms. The improvement of the residual error was of a much lower return. These performances are close to making possible the use of autodidactic equalization in the mobile radio system.

  2. UWB Tracking System Design with TDOA Algorithm

    NASA Technical Reports Server (NTRS)

    Ni, Jianjun; Arndt, Dickey; Ngo, Phong; Phan, Chau; Gross, Julia; Dusl, John; Schwing, Alan

    2006-01-01

    This presentation discusses an ultra-wideband (UWB) tracking system design effort using a tracking algorithm TDOA (Time Difference of Arrival). UWB technology is exploited to implement the tracking system due to its properties, such as high data rate, fine time resolution, and low power spectral density. A system design using commercially available UWB products is proposed. A two-stage weighted least square method is chosen to solve the TDOA non-linear equations. Matlab simulations in both two-dimensional space and three-dimensional space show that the tracking algorithm can achieve fine tracking resolution with low noise TDOA data. The error analysis reveals various ways to improve the tracking resolution. Lab experiments demonstrate the UWBTDOA tracking capability with fine resolution. This research effort is motivated by a prototype development project Mini-AERCam (Autonomous Extra-vehicular Robotic Camera), a free-flying video camera system under development at NASA Johnson Space Center for aid in surveillance around the International Space Station (ISS).

  3. ``Fast Track'' nuclear thermal propulsion concept

    NASA Astrophysics Data System (ADS)

    Johnson, Richard A.; Zweig, Herbert R.; Cooper, Martin H.; Wett, Jack

    1993-01-01

    The objective of the Space Exploration Initiative (``America at the Threshold...,'' 1991) is the exploration of Mars by man in the second decade of the 21st century. The NASA ``Fast Track'' approach (NASA-LeRC Presentation, 1992) could accelerate the manned exploration of Mars to 2007. NERVA-derived nuclear propulsion represents a viable near-term technology approach to accomplish the accelerated schedule. Key milestones in the progression to the manned Mars mission are (1) demonstration of TRL-6 for the man-rateable system by 1999, (2) a robotic lunar mission by 2000, (3) the first cargo mission to Mars by 2005, and (4) the piloted Mars mission in 2007. The Rocketdyne-Westinghouse concept for nuclear thermal propulsion to achieve these milestones combines the nuclear reactor technology of the Rover/NERVA programs and the state-of-the-art hardware designs from hydrogen-fueled rocket engine successes like the Space Shuttle Main Engine (SSME).

  4. Security market reaction to FDA fast track designations.

    PubMed

    Anderson, Christopher W; Zhang, Ying

    2010-01-01

    Pharmaceutical firms can apply for the Food and Drug Administration to 'fast track' research and de velopment on new drugs, accelerating clinical trials and expediting regulatory review required prior to marketing to consumers. We investigate security market reaction to more than 100 fast track designations from 1998 to 2004. Fast track designation appears to enhance investor recognition of firm value. Specifically, fast track designation coincides with abnormal trading volume and excess daily stock returns for sponsoring firms. Institutional ownership and analyst attention also increase. Market response is more pronounced for firms that are smaller, do not yet market products, and have low institutional ownership.

  5. The influence of preoperative risk stratification on fast-tracking patients after pulmonary resection.

    PubMed

    Bryant, Ayesha S; Cerfolio, Robert J

    2008-02-01

    Fast-tracking protocols or postoperative care computerized algorithms have been shown to reduce hospital length of stay and reduce costs; however, not all patients can be fast-tracked. Certain patient characteristics may put patients at increased risk to fail fast-tracking. Additionally some patients have multiple risk factors that have an additive effect that puts them at an even increased risk to fail fast-tracking, and more importantly, to significant morbidity. It is a mistake to force these protocols on all patients because it can lead to increased complications, readmissions, and low patient and family satisfaction. By carefully analyzing surgical results via accurate prospective databases, the types of patients who fail fast-tracking and the reasons they fail can be identified. Once these characteristics are pinpointed, specific changes to the postoperative algorithm can be implemented, and these alterations can lead to improved outcomes. The authors have shown that by using pain pumps instead of epidurals in elderly patients we can improve outcomes and still fast-track octogenarians with minimal morbidity and high-patient satisfaction. We have also shown that the increased use of physical therapy and respiratory treatments (important parts of the care of all patients after pulmonary resection, but a limited resource in most hospitals) may also lead to improved surgical results for those who have low FEV1% and DLco%. Further studies are needed. Although fast-tracking protocols cannot be applied to all, the vast majority of patients who undergo elective pulmonary resection, even those at high risk, can undergo safe, efficient, and cost-saving care via preset postoperative algorithms. When the typical daily events are convened each morning and the planned date of discharge is frequently communicated with the patient and family before surgery and each day in the hospital, most patients can be safely fast-tracked with high satisfaction and outstanding results.

  6. Fast Track: A Language Arts Program for Middle School Gifted

    ERIC Educational Resources Information Center

    Schneider, Jean

    2008-01-01

    "Fast Track" is a pseudonym for an accelerated, advanced language arts program for verbally gifted and high potential students in grades 6-8. The critical thinking model used for "Fast Track" was gleaned from Coalition of Essential Schools founder Ted Sizer's Habits of Mind: significance, evidence, connections, perspective, and supposition, as…

  7. Fast Track Teaching: Beginning the Experiment in Accelerated Leadership Development

    ERIC Educational Resources Information Center

    Churches, Richard; Hutchinson, Geraldine; Jones, Jeff

    2009-01-01

    This article provides an overview of the development of the Fast Track teaching programme and personalised nature of the training and support that has been delivered. Fast Track teacher promotion rates are compared to national statistics demonstrating significant progression for certain groups, particularly women. (Contains 3 tables and 3 figures.)

  8. Fixed Point Implementations of Fast Kalman Algorithms.

    DTIC Science & Technology

    1983-11-01

    fined point multiply. ve &geete a meatn ’C.- nero. variance N random vector s~t) each time weAfilter is said to be 12 Scaled if udae 8(t+11t0 - 3-1* AS...nl.v by bl ’k rn.b.) 20 AST iA C T ’Cnnin to .- a , o. a ide It .,oco ea ry and Idenuty by block number) In this paper we study scaling rules and round...realized in a -fast form that uses the so-called fast Kalman gain algorithm. The algorithm for the gain is fixed point. Scaling rules and expressions for

  9. Fast regional readout CMOS Image Sensor for dynamic MLC tracking

    NASA Astrophysics Data System (ADS)

    Zin, H.; Harris, E.; Osmond, J.; Evans, P.

    2014-03-01

    Advanced radiotherapy techniques such as volumetric modulated arc therapy (VMAT) require verification of the complex beam delivery including tracking of multileaf collimators (MLC) and monitoring the dose rate. This work explores the feasibility of a prototype Complementary metal-oxide semiconductor Image Sensor (CIS) for tracking these complex treatments by utilising fast, region of interest (ROI) read out functionality. An automatic edge tracking algorithm was used to locate the MLC leaves edges moving at various speeds (from a moving triangle field shape) and imaged with various sensor frame rates. The CIS demonstrates successful edge detection of the dynamic MLC motion within accuracy of 1.0 mm. This demonstrates the feasibility of the sensor to verify treatment delivery involving dynamic MLC up to ~400 frames per second (equivalent to the linac pulse rate), which is superior to any current techniques such as using electronic portal imaging devices (EPID). CIS provides the basis to an essential real-time verification tool, useful in accessing accurate delivery of complex high energy radiation to the tumour and ultimately to achieve better cure rates for cancer patients.

  10. Python algorithms in particle tracking microrheology

    PubMed Central

    2012-01-01

    Background Particle tracking passive microrheology relates recorded trajectories of microbeads, embedded in soft samples, to the local mechanical properties of the sample. The method requires intensive numerical data processing and tools allowing control of the calculation errors. Results We report the development of a software package collecting functions and scripts written in Python for automated and manual data processing, to extract viscoelastic information about the sample using recorded particle trajectories. The resulting program package analyzes the fundamental diffusion characteristics of particle trajectories and calculates the frequency dependent complex shear modulus using methods published in the literature. In order to increase conversion accuracy, segmentwise, double step, range-adaptive fitting and dynamic sampling algorithms are introduced to interpolate the data in a splinelike manner. Conclusions The presented set of algorithms allows for flexible data processing for particle tracking microrheology. The package presents improved algorithms for mean square displacement estimation, controlling effects of frame loss during recording, and a novel numerical conversion method using segmentwise interpolation, decreasing the conversion error from about 100% to the order of 1%. PMID:23186362

  11. Are Wait-Free Algorithms Fast

    DTIC Science & Technology

    1991-03-01

    AMASSACHUSETTSLABORATORY FOR INSTITUTE OFCOMPUTER SCIENCE TECHNOLOGY MIT/ILCS/TM-442 m ARE WAIT-FREE N ALGORITHMS FAST?I DTICSELECTE MAR27199111 ~D...Hagit Attiya Nancy Lynch Nir Shavit Approve to T - e eT A March 1991 545 TECHNOLOGY SQUARE, CAMBRIDGE, MASSACHUSETTS 02139 22 089 igclassified XICURITY...ADDRESS (City, State, and ZIP Code) 7b. ADDRESS (ft) State, and ZIP Code) 545 Technology Square Information Systems Program Cambridge, MA 02139

  12. Fast TracKer: A fast hardware track trigger for the ATLAS detector

    NASA Astrophysics Data System (ADS)

    Pandini, Carlo

    2016-07-01

    The trigger system at the ATLAS experiment is designed to lower the event rate occurring from the nominal bunch crossing rate of 40 MHz to about 1 kHz for a LHC luminosity of the order of 1034cm-2s-1. To achieve high background rejection while maintaining good efficiency for interesting physics signals, sophisticated algorithms are needed which require an extensive use of tracking information. The Fast TracKer (FTK) trigger system, part of the ATLAS trigger upgrade program, is a highly parallel hardware device designed to perform track-finding at 100 kHz. Modern, powerful Field Programmable Gate Arrays (FPGAs) form an important part of the system architecture, and the combinatorial problem of pattern recognition is solved by 8000 standard-cell ASICs used to implement an Associative Memory architecture. The availability of the tracking and subsequent vertex information within a short latency ensures robust selections and allows improved trigger performance for the most difficult signatures, such as b-jets and τ leptons.

  13. Fast-Acquisition/Weak-Signal-Tracking GPS Receiver for HEO

    NASA Technical Reports Server (NTRS)

    Wintemitz, Luke; Boegner, Greg; Sirotzky, Steve

    2004-01-01

    A report discusses the technical background and design of the Navigator Global Positioning System (GPS) receiver -- . a radiation-hardened receiver intended for use aboard spacecraft. Navigator is capable of weak signal acquisition and tracking as well as much faster acquisition of strong or weak signals with no a priori knowledge or external aiding. Weak-signal acquisition and tracking enables GPS use in high Earth orbits (HEO), and fast acquisition allows for the receiver to remain without power until needed in any orbit. Signal acquisition and signal tracking are, respectively, the processes of finding and demodulating a signal. Acquisition is the more computationally difficult process. Previous GPS receivers employ the method of sequentially searching the two-dimensional signal parameter space (code phase and Doppler). Navigator exploits properties of the Fourier transform in a massively parallel search for the GPS signal. This method results in far faster acquisition times [in the lab, 12 GPS satellites have been acquired with no a priori knowledge in a Low-Earth-Orbit (LEO) scenario in less than one second]. Modeling has shown that Navigator will be capable of acquiring signals down to 25 dB-Hz, appropriate for HEO missions. Navigator is built using the radiation-hardened ColdFire microprocessor and housing the most computationally intense functions in dedicated field-programmable gate arrays. The high performance of the algorithm and of the receiver as a whole are made possible by optimizing computational efficiency and carefully weighing tradeoffs among the sampling rate, data format, and data-path bit width.

  14. MATLAB tensor classes for fast algorithm prototyping.

    SciTech Connect

    Bader, Brett William; Kolda, Tamara Gibson

    2004-10-01

    Tensors (also known as mutidimensional arrays or N-way arrays) are used in a variety of applications ranging from chemometrics to psychometrics. We describe four MATLAB classes for tensor manipulations that can be used for fast algorithm prototyping. The tensor class extends the functionality of MATLAB's multidimensional arrays by supporting additional operations such as tensor multiplication. The tensor as matrix class supports the 'matricization' of a tensor, i.e., the conversion of a tensor to a matrix (and vice versa), a commonly used operation in many algorithms. Two additional classes represent tensors stored in decomposed formats: cp tensor and tucker tensor. We descibe all of these classes and then demonstrate their use by showing how to implement several tensor algorithms that have appeared in the literature.

  15. Fast deterministic algorithm for EEE components classification

    NASA Astrophysics Data System (ADS)

    Kazakovtsev, L. A.; Antamoshkin, A. N.; Masich, I. S.

    2015-10-01

    Authors consider the problem of automatic classification of the electronic, electrical and electromechanical (EEE) components based on results of the test control. Electronic components of the same type used in a high- quality unit must be produced as a single production batch from a single batch of the raw materials. Data of the test control are used for splitting a shipped lot of the components into several classes representing the production batches. Methods such as k-means++ clustering or evolutionary algorithms combine local search and random search heuristics. The proposed fast algorithm returns a unique result for each data set. The result is comparatively precise. If the data processing is performed by the customer of the EEE components, this feature of the algorithm allows easy checking of the results by a producer or supplier.

  16. TRACKING TESTS FOR THE SNS FAST INJECTION BUMP POWER SUPPLY

    SciTech Connect

    ENG,W.CUTLER,R.DEWAN,S.ET AL.

    2004-07-05

    The tracking requirement of the SNS Fast Injection Bump power supplies is described. In addition to the usual tracking between the load current and the input reference of a power supply, these power supplies must also track between pairs of units under slightly different loads. This paper describes the use of a current-null test to measure tracking performances. For the actual tests, a single dummy magnet load was used to measure the tracking between the first two production units at the manufacturer's facility. Using the Yokogawa WE7000 waveform. PC-based measurement instrument, input and output waveforms are digitized and stored in data files. A program written for this application is then used to extract data from these files to construct, analyze the waveforms and characterize the power supply performance. Results of the measurements of two SNS Fast Injection Bump power supplies will be presented in this paper.

  17. Fast box-counting algorithm on GPU.

    PubMed

    Jiménez, J; Ruiz de Miras, J

    2012-12-01

    The box-counting algorithm is one of the most widely used methods for calculating the fractal dimension (FD). The FD has many image analysis applications in the biomedical field, where it has been used extensively to characterize a wide range of medical signals. However, computing the FD for large images, especially in 3D, is a time consuming process. In this paper we present a fast parallel version of the box-counting algorithm, which has been coded in CUDA for execution on the Graphic Processing Unit (GPU). The optimized GPU implementation achieved an average speedup of 28 times (28×) compared to a mono-threaded CPU implementation, and an average speedup of 7 times (7×) compared to a multi-threaded CPU implementation. The performance of our improved box-counting algorithm has been tested with 3D models with different complexity, features and sizes. The validity and accuracy of the algorithm has been confirmed using models with well-known FD values. As a case study, a 3D FD analysis of several brain tissues has been performed using our GPU box-counting algorithm.

  18. Real time tracking with a silicon telescope prototype using the "artificial retina" algorithm

    NASA Astrophysics Data System (ADS)

    Abba, A.; Bedeschi, F.; Caponio, F.; Cenci, R.; Citterio, M.; Coelli, S.; Fu, J.; Geraci, A.; Grizzuti, M.; Lusardi, N.; Marino, P.; Monti, M.; Morello, M. J.; Neri, N.; Ninci, D.; Petruzzo, M.; Piucci, A.; Punzi, G.; Ristori, L.; Spinella, F.; Stracka, S.; Tonelli, D.; Walsh, J.

    2016-07-01

    We present the first prototype of a silicon tracker using the artificial retina algorithm for fast track finding. The algorithm is inspired by the neurobiological mechanism of recognition of edges in mammals visual cortex. It is based on extensive parallelization and is implemented on commercial FPGAs allowing us to reconstruct real time tracks with offline-like quality and < 1 μs latencies. The practical device consists of a telescope with 8 single-sided silicon strip sensors and custom DAQ boards equipped with Xilinx Kintex 7 FPGAs that perform the readout of the sensors and the track reconstruction in real time.

  19. Automatic face detection and tracking based on Adaboost with camshift algorithm

    NASA Astrophysics Data System (ADS)

    Lin, Hui; Long, JianFeng

    2011-10-01

    With the development of information technology, video surveillance is widely used in security monitoring and identity recognition. For most of pure face tracking algorithms are hard to specify the initial location and scale of face automatically, this paper proposes a fast and robust method to detect and track face by combining adaboost with camshift algorithm. At first, the location and scale of face is specified by adaboost algorithm based on Haar-like features and it will be conveyed to the initial search window automatically. Then, we apply camshift algorithm to track face. The experimental results based on OpenCV software yield good results, even in some special circumstances, such as light changing and face rapid movement. Besides, by drawing out the tracking trajectory of face movement, some abnormal behavior events can be analyzed.

  20. FOGSAA: Fast Optimal Global Sequence Alignment Algorithm

    NASA Astrophysics Data System (ADS)

    Chakraborty, Angana; Bandyopadhyay, Sanghamitra

    2013-04-01

    In this article we propose a Fast Optimal Global Sequence Alignment Algorithm, FOGSAA, which aligns a pair of nucleotide/protein sequences faster than any optimal global alignment method including the widely used Needleman-Wunsch (NW) algorithm. FOGSAA is applicable for all types of sequences, with any scoring scheme, and with or without affine gap penalty. Compared to NW, FOGSAA achieves a time gain of (70-90)% for highly similar nucleotide sequences (> 80% similarity), and (54-70)% for sequences having (30-80)% similarity. For other sequences, it terminates with an approximate score. For protein sequences, the average time gain is between (25-40)%. Compared to three heuristic global alignment methods, the quality of alignment is improved by about 23%-53%. FOGSAA is, in general, suitable for aligning any two sequences defined over a finite alphabet set, where the quality of the global alignment is of supreme importance.

  1. Fast computation algorithms for speckle pattern simulation

    SciTech Connect

    Nascov, Victor; Samoilă, Cornel; Ursuţiu, Doru

    2013-11-13

    We present our development of a series of efficient computation algorithms, generally usable to calculate light diffraction and particularly for speckle pattern simulation. We use mainly the scalar diffraction theory in the form of Rayleigh-Sommerfeld diffraction formula and its Fresnel approximation. Our algorithms are based on a special form of the convolution theorem and the Fast Fourier Transform. They are able to evaluate the diffraction formula much faster than by direct computation and we have circumvented the restrictions regarding the relative sizes of the input and output domains, met on commonly used procedures. Moreover, the input and output planes can be tilted each to other and the output domain can be off-axis shifted.

  2. Fast Markerless Tracking for Augmented Reality in Planar Environment

    NASA Astrophysics Data System (ADS)

    Basori, Ahmad Hoirul; Afif, Fadhil Noer; Almazyad, Abdulaziz S.; AbuJabal, Hamza Ali S.; Rehman, Amjad; Alkawaz, Mohammed Hazim

    2015-12-01

    Markerless tracking for augmented reality should not only be accurate but also fast enough to provide a seamless synchronization between real and virtual beings. Current reported methods showed that a vision-based tracking is accurate but requires high computational power. This paper proposes a real-time hybrid-based method for tracking unknown environments in markerless augmented reality. The proposed method provides collaboration of vision-based approach with accelerometers and gyroscopes sensors as camera pose predictor. To align the augmentation relative to camera motion, the tracking method is done by substituting feature-based camera estimation with combination of inertial sensors with complementary filter to provide more dynamic response. The proposed method managed to track unknown environment with faster processing time compared to available feature-based approaches. Moreover, the proposed method can sustain its estimation in a situation where feature-based tracking loses its track. The collaboration of sensor tracking managed to perform the task for about 22.97 FPS, up to five times faster than feature-based tracking method used as comparison. Therefore, the proposed method can be used to track unknown environments without depending on amount of features on scene, while requiring lower computational cost.

  3. A fast DFT algorithm using complex integer transforms

    NASA Technical Reports Server (NTRS)

    Reed, I. S.; Truong, T. K.

    1978-01-01

    Winograd's algorithm for computing the discrete Fourier transform is extended considerably for certain large transform lengths. This is accomplished by performing the cyclic convolution, required by Winograd's method, by a fast transform over certain complex integer fields. This algorithm requires fewer multiplications than either the standard fast Fourier transform or Winograd's more conventional algorithms.

  4. Global Linking of Cell Tracks Using the Viterbi Algorithm

    PubMed Central

    Jaldén, Joakim; Gilbert, Penney M.; Blau, Helen M.

    2016-01-01

    Automated tracking of living cells in microscopy image sequences is an important and challenging problem. With this application in mind, we propose a global track linking algorithm, which links cell outlines generated by a segmentation algorithm into tracks. The algorithm adds tracks to the image sequence one at a time, in a way which uses information from the complete image sequence in every linking decision. This is achieved by finding the tracks which give the largest possible increases to a probabilistically motivated scoring function, using the Viterbi algorithm. We also present a novel way to alter previously created tracks when new tracks are created, thus mitigating the effects of error propagation. The algorithm can handle mitosis, apoptosis, and migration in and out of the imaged area, and can also deal with false positives, missed detections, and clusters of jointly segmented cells. The algorithm performance is demonstrated on two challenging datasets acquired using bright-field microscopy, but in principle, the algorithm can be used with any cell type and any imaging technique, presuming there is a suitable segmentation algorithm. PMID:25415983

  5. Fast Track: Elementary School. What Works Clearinghouse Intervention Report

    ERIC Educational Resources Information Center

    What Works Clearinghouse, 2014

    2014-01-01

    "Fast Track" is a comprehensive intervention designed to reduce conduct problems and promote academic, behavioral, and social improvement. The program's components include the "Promoting Alternative THinking Strategies" curriculum, parent groups, parent-child sharing time, child social skills training, home visiting, child…

  6. Fast-Track Cleanup at Closing DoD Installations

    EPA Pesticide Factsheets

    The Fast-Track Cleanup program strives to make parcels available for reuse as quickly as possible by the transfer of uncontaminated or remediated parcels, the lease of contaminated parcels where cleanup is underway, or the 'early transfer' of contaminated property undergoing cleanup.

  7. Teacher Perspectives on Their Alternative Fast-Track Induction

    ERIC Educational Resources Information Center

    Haim, Orly; Amdur, Lisa

    2016-01-01

    The purpose of this study was to explore the professional challenges and concerns of 30 second career teachers (SCTs) participating in an alternative fast-track induction program during their first year of teaching. Additionally, the study investigated their perspectives of the institutional support provided to them. The main source of data was…

  8. Fast Track to Success: Top Young Trainers 2012

    ERIC Educational Resources Information Center

    Freifeld, Lorri

    2012-01-01

    Supercharged. High-performers. Leaders of the pack. This article presents "Training" magazine's 2012 Top Young Trainers--those high-potential training professionals who are on the fast track to success. For the fifth year, "Training" magazine is pleased to recognize the outstanding talents, accomplishments, and leadership exhibited by 40 learning…

  9. Education For All (EFA) - Fast Track Initiative Progress Report 30046

    ERIC Educational Resources Information Center

    World Bank Education Advisory Service, 2004

    2004-01-01

    Launched in June 2002, the Education For All-Fast Track Initiative (FTI) is a performance-based program focusing on the implementation of sustainable policies in support of universal primary completion (UPC) and the required resource mobilization. During its twenty months of implementation, FTI has delivered on results, which give reason for…

  10. Fast linear algorithms for machine learning

    NASA Astrophysics Data System (ADS)

    Lu, Yichao

    Nowadays linear methods like Regression, Principal Component Analysis and Canonical Correlation Analysis are well understood and widely used by the machine learning community for predictive modeling and feature generation. Generally speaking, all these methods aim at capturing interesting subspaces in the original high dimensional feature space. Due to the simple linear structures, these methods all have a closed form solution which makes computation and theoretical analysis very easy for small datasets. However, in modern machine learning problems it's very common for a dataset to have millions or billions of features and samples. In these cases, pursuing the closed form solution for these linear methods can be extremely slow since it requires multiplying two huge matrices and computing inverse, inverse square root, QR decomposition or Singular Value Decomposition (SVD) of huge matrices. In this thesis, we consider three fast algorithms for computing Regression and Canonical Correlation Analysis approximate for huge datasets.

  11. 4D fast tracking for experiments at high luminosity LHC

    NASA Astrophysics Data System (ADS)

    Neri, N.; Cardini, A.; Calabrese, R.; Fiorini, M.; Luppi, E.; Marconi, U.; Petruzzo, M.

    2016-11-01

    The full exploitation of the physics potential of the high luminosity LHC is a big challenge that requires new instrumentation and innovative solutions. We present here a conceptual design and simulation studies of a fast timing pixel detector with embedded real-time tracking capabilities. The system is conceived to operate at 40 MHz event rate and to reconstruct tracks in real-time, using precise space and time 4D information of the hit, for fast trigger decisions. This work is part of an R&D project aimed at building an innovative tracking detector with superior time (10 ps) and position (10 μm) resolutions to be used in very harsh radiation environments, for the ultimate flavour physics experiment at the high luminosity phase of the LHC.

  12. Region labeling algorithm based on boundary tracking for binary image

    NASA Astrophysics Data System (ADS)

    Chen, Li; Yang, Yang; Cen, Zhaofeng; Li, Xiaotong

    2010-11-01

    Region labeling for binary image is an important part of image processing. For the special use of small and multi-objects labeling, a new region labeling algorithm based on boundary tracking is proposed in this paper. Experiments prove that our algorithm is feasible and efficient, and even faster than some of other algorithms.

  13. Fast algorithm for computing complex number-theoretic transforms

    NASA Technical Reports Server (NTRS)

    Reed, I. S.; Liu, K. Y.; Truong, T. K.

    1977-01-01

    A high-radix FFT algorithm for computing transforms over FFT, where q is a Mersenne prime, is developed to implement fast circular convolutions. This new algorithm requires substantially fewer multiplications than the conventional FFT.

  14. Fast template matching based on grey prediction for real-time object tracking

    NASA Astrophysics Data System (ADS)

    Lv, Mingming; Hou, Yuanlong; Liu, Rongzhong; Hou, Runmin

    2017-02-01

    Template matching is a basic algorithm for image processing, and real-time is a crucial requirement of object tracking. For real-time tracking, a fast template matching algorithm based on grey prediction is presented, where computation cost can be reduced dramatically by minimizing search range. First, location of the tracked object in the current image is estimated by Grey Model (GM). GM(1,1), which is the basic model of grey prediction, can use some known information to foretell the location. Second, the precise position of the object in the frame is computed by template matching. Herein, Sequential Similarity Detection Algorithm (SSDA) with a self-adaptive threshold is employed to obtain the matching position in the neighborhood of the predicted location. The role of threshold in SSDA is important, as a proper threshold can make template matching fast and accurate. Moreover, a practical weighted strategy is utilized to handle scale and rotation changes of the object, as well as illumination changes. The experimental results show the superior performance of the proposed algorithm over the conventional full-search method, especially in terms of executive time.

  15. Modeling and performance analysis of GPS vector tracking algorithms

    NASA Astrophysics Data System (ADS)

    Lashley, Matthew

    This dissertation provides a detailed analysis of GPS vector tracking algorithms and the advantages they have over traditional receiver architectures. Standard GPS receivers use a decentralized architecture that separates the tasks of signal tracking and position/velocity estimation. Vector tracking algorithms combine the two tasks into a single algorithm. The signals from the various satellites are processed collectively through a Kalman filter. The advantages of vector tracking over traditional, scalar tracking methods are thoroughly investigated. A method for making a valid comparison between vector and scalar tracking loops is developed. This technique avoids the ambiguities encountered when attempting to make a valid comparison between tracking loops (which are characterized by noise bandwidths and loop order) and the Kalman filters (which are characterized by process and measurement noise covariance matrices) that are used by vector tracking algorithms. The improvement in performance offered by vector tracking is calculated in multiple different scenarios. Rule of thumb analysis techniques for scalar Frequency Lock Loops (FLL) are extended to the vector tracking case. The analysis tools provide a simple method for analyzing the performance of vector tracking loops. The analysis tools are verified using Monte Carlo simulations. Monte Carlo simulations are also used to study the effects of carrier to noise power density (C/N0) ratio estimation and the advantage offered by vector tracking over scalar tracking. The improvement from vector tracking ranges from 2.4 to 6.2 dB in various scenarios. The difference in the performance of the three vector tracking architectures is analyzed. The effects of using a federated architecture with and without information sharing between the receiver's channels are studied. A combination of covariance analysis and Monte Carlo simulation is used to analyze the performance of the three algorithms. The federated algorithm without

  16. Performance of a wavelength-diversified FSO tracking algorithm for real-time battlefield communications

    NASA Astrophysics Data System (ADS)

    Al-Akkoumi, Mouhammad K.; Harris, Alan; Huck, Robert C.; Sluss, James J., Jr.; Giuma, Tayeb A.

    2008-02-01

    Free-space optical (FSO) communications links are envisioned as a viable option for the provision of temporary high-bandwidth communication links between moving platforms, especially for deployment in battlefield situations. For successful deployment in such real-time environments, fast and accurate alignment and tracking of the FSO equipment is essential. In this paper, a two-wavelength diversity scheme using 1.55 μm and 10 μm is investigated in conjunction with a previously described tracking algorithm to maintain line-of-sight connectivity battlefield scenarios. An analytical model of a mobile FSO communications link is described. Following the analytical model, simulation results are presented for an FSO link between an unmanned aerial surveillance vehicle, the Global Hawk, with a mobile ground vehicle, an M1 Abrams Main Battle Tank. The scenario is analyzed under varying weather conditions to verify continuous connectivity is available through the tracking algorithm. Simulation results are generated to describe the performance of the tracking algorithm with respect to both received optical power levels and variations in beam divergence. Advances to any proposed tracking algorithm due to these power and divergence variations are described for future tracking algorithm development.

  17. Target classification algorithm based on feature aided tracking

    NASA Astrophysics Data System (ADS)

    Zhan, Ronghui; Zhang, Jun

    2013-03-01

    An effective target classification algorithm based on feature aided tracking (FAT) is proposed, using the length of target (target extent) as the classification information. To implement the algorithm, the Rao-Blackwellised unscented Kalman filter (RBUKF) is used to jointly estimate the kinematic state and target extent; meanwhile the joint probability data association (JPDA) algorithm is exploited to implement multi-target data association aided by target down-range extent. Simulation results under different condition show the presented algorithm is both accurate and robust, and it is suitable for the application of near spaced targets tracking and classification under the environment of dense clutters.

  18. A maximum power point tracking algorithm for photovoltaic applications

    NASA Astrophysics Data System (ADS)

    Nelatury, Sudarshan R.; Gray, Robert

    2013-05-01

    The voltage and current characteristic of a photovoltaic (PV) cell is highly nonlinear and operating a PV cell for maximum power transfer has been a challenge for a long time. Several techniques have been proposed to estimate and track the maximum power point (MPP) in order to improve the overall efficiency of a PV panel. A strategic use of the mean value theorem permits obtaining an analytical expression for a point that lies in a close neighborhood of the true MPP. But hitherto, an exact solution in closed form for the MPP is not published. This problem can be formulated analytically as a constrained optimization, which can be solved using the Lagrange method. This method results in a system of simultaneous nonlinear equations. Solving them directly is quite difficult. However, we can employ a recursive algorithm to yield a reasonably good solution. In graphical terms, suppose the voltage current characteristic and the constant power contours are plotted on the same voltage current plane, the point of tangency between the device characteristic and the constant power contours is the sought for MPP. It is subject to change with the incident irradiation and temperature and hence the algorithm that attempts to maintain the MPP should be adaptive in nature and is supposed to have fast convergence and the least misadjustment. There are two parts in its implementation. First, one needs to estimate the MPP. The second task is to have a DC-DC converter to match the given load to the MPP thus obtained. Availability of power electronics circuits made it possible to design efficient converters. In this paper although we do not show the results from a real circuit, we use MATLAB to obtain the MPP and a buck-boost converter to match the load. Under varying conditions of load resistance and irradiance we demonstrate MPP tracking in case of a commercially available solar panel MSX-60. The power electronics circuit is simulated by PSIM software.

  19. Fast left ventricle tracking using localized anatomical affine optical flow.

    PubMed

    Queirós, Sandro; Vilaça, João L; Morais, Pedro; Fonseca, Jaime C; D'hooge, Jan; Barbosa, Daniel

    2017-02-16

    In daily clinical cardiology practice, left ventricle (LV) global and regional function assessment is crucial for disease diagnosis, therapy selection and patient follow-up. Currently, this is still a time-consuming task, spending valuable human resources. In this work, a novel fast methodology for automatic LV tracking is proposed based on localized anatomically constrained affine optical flow. This novel method can be combined to previously proposed segmentation frameworks or manually delineated surfaces at an initial frame to obtain fully delineated datasets and, thus, assess both global and regional myocardial function. Its feasibility and accuracy was investigated in three distinct public databases, namely in realistically simulated 3D ultrasound (US), clinical 3D echocardiography and clinical cine cardiac magnetic resonance (CMR) images. The method showed accurate tracking results in all databases, proving its applicability and accuracy for myocardial function assessment. Moreover, when combined to previous state-of-the-art segmentation frameworks, it outperformed previous tracking strategies in both 3D US and CMR data, automatically computing relevant cardiac indices with smaller biases and narrower limits of agreement compared to reference indices. Simultaneously, the proposed localized tracking method showed to be suitable for online processing, even for 3D motion assessment. Importantly, although here evaluated for LV tracking only, this novel methodology is applicable for tracking of other target structures with minimal adaptations. This article is protected by copyright. All rights reserved.

  20. Automatic Tracking Algorithm in Coaxial Near-Infrared Laser Ablation Endoscope for Fetus Surgery

    NASA Astrophysics Data System (ADS)

    Hu, Yan; Yamanaka, Noriaki; Masamune, Ken

    2014-07-01

    This article reports a stable vessel object tracking method for the treatment of twin-to-twin transfusion syndrome based on our previous 2 DOF endoscope. During the treatment of laser coagulation, it is necessary to focus on the exact position of the target object, however it moves by the mother's respiratory motion and still remains a challenge to obtain and track the position precisely. In this article, an algorithm which uses features from accelerated segment test (FAST) to extract the features and optical flow as the object tracking method, is proposed to deal with above problem. Further, we experimentally simulate the movement due to the mother's respiration, and the results of position errors and similarity verify the effectiveness of the proposed tracking algorithm for laser ablation endoscopy in-vitro and under water considering two influential factors. At average, the errors are about 10 pixels and the similarity over 0.92 are obtained in the experiments.

  1. Fast-track drug approval in inflammatory bowel diseases

    PubMed Central

    Katsanos, Konstantinos H.; Koutroumpakis, Efstratios; Giagkou, Eftychia; Malakos, Zikos; Almpani, Eleni; Skamnelos, Alexandros; Christodoulou, Dimitrios K.

    2016-01-01

    Fast-track drug designation of safe regimens represents an emerging method of development and approval of new medications targeting debilitating diseases including inflammatory bowel diseases (IBD). The goal of accelerated drug approval pathways is to shorten the time between application and approval of therapies that treat diseases with significant morbidity and mortality. Recently, fast-track drug approval approaches were supported by data deriving from central reading of images, a method of clinical data interpretation that has significantly benefited patients with gastrointestinal disorders. Biological agents and other emerging therapies in IBD represent “game-changing” or “treat-to-target” drugs and have satisfied quite successfully some of the patients’ unmet needs. The development of biosimilars is an area where the Federal Drug Administration and the European Agency for Evaluation of Medicinal Products seem to have different approval processes. Biosimilars, including those for IBD, promise cost reductions and wide access to biologic therapies by patients, advantages similar to those already offered by generic drugs. Given the rapid development of IBD drugs and patients’ needs, a consensus among the academic community, clinicians, researchers, sponsors, patients and regulatory authorities is required to standardize better the IBD trials and create a productive environment for fast-track approval of any “changing-game” IBD drug. PMID:27708508

  2. Research of maneuvering target prediction and tracking technology based on IMM algorithm

    NASA Astrophysics Data System (ADS)

    Cao, Zheng; Mao, Yao; Deng, Chao; Liu, Qiong; Chen, Jing

    2016-09-01

    Maneuvering target prediction and tracking technology is widely used in both military and civilian applications, the study of those technologies is all along the hotspot and difficulty. In the Electro-Optical acquisition-tracking-pointing system (ATP), the primary traditional maneuvering targets are ballistic target, large aircraft and other big targets. Those targets have the features of fast velocity and a strong regular trajectory and Kalman Filtering and polynomial fitting have good effects when they are used to track those targets. In recent years, the small unmanned aerial vehicles developed rapidly for they are small, nimble and simple operation. The small unmanned aerial vehicles have strong maneuverability in the observation system of ATP although they are close-in, slow and small targets. Moreover, those vehicles are under the manual operation, therefore, the acceleration of them changes greatly and they move erratically. So the prediction and tracking precision is low when traditional algorithms are used to track the maneuvering fly of those targets, such as speeding up, turning, climbing and so on. The interacting multiple model algorithm (IMM) use multiple models to match target real movement trajectory, there are interactions between each model. The IMM algorithm can switch model based on a Markov chain to adapt to the change of target movement trajectory, so it is suitable to solve the prediction and tracking problems of the small unmanned aerial vehicles because of the better adaptability of irregular movement. This paper has set up model set of constant velocity model (CV), constant acceleration model (CA), constant turning model (CT) and current statistical model. And the results of simulating and analyzing the real movement trajectory data of the small unmanned aerial vehicles show that the prediction and tracking technology based on the interacting multiple model algorithm can get relatively lower tracking error and improve tracking precision

  3. Video tracking algorithm of long-term experiment using stand-alone recording system

    NASA Astrophysics Data System (ADS)

    Chen, Yu-Jen; Li, Yan-Chay; Huang, Ke-Nung; Jen, Sun-Lon; Young, Ming-Shing

    2008-08-01

    Many medical and behavioral applications require the ability to monitor and quantify the behavior of small animals. In general these animals are confined in small cages. Often these situations involve very large numbers of cages. Modern research facilities commonly monitor simultaneously thousands of animals over long periods of time. However, conventional systems require one personal computer per monitoring platform, which is too complex, expensive, and increases power consumption for large laboratory applications. This paper presents a simplified video tracking algorithm for long-term recording using a stand-alone system. The feature of the presented tracking algorithm revealed that computation speed is very fast data storage requirements are small, and hardware requirements are minimal. The stand-alone system automatically performs tracking and saving acquired data to a secure digital card. The proposed system is designed for video collected at a 640×480 pixel with 16 bit color resolution. The tracking result is updated every 30 frames/s. Only the locomotive data are stored. Therefore, the data storage requirements could be minimized. In addition, detection via the designed algorithm uses the Cb and Cr values of a colored marker affixed to the target to define the tracked position and allows multiobject tracking against complex backgrounds. Preliminary experiment showed that such tracking information stored by the portable and stand-alone system could provide comprehensive information on the animal's activity.

  4. DETECTORS AND EXPERIMENTAL METHODS: BESIII track fitting algorithm

    NASA Astrophysics Data System (ADS)

    Wang, Ji-Ke; Mao, Ze-Pu; Bian, Jian-Ming; Cao, Guo-Fu; Cao, Xue-Xiang; Chen, Shen-Jian; Deng, Zi-Yan; Fu, Cheng-Dong; Gao, Yuan-Ning; He, Kang-Lin; He, Miao; Hua, Chun-Fei; Huang, Bin; Huang, Xing-Tao; Ji, Xiao-Bin; Li, Fei; Li, Bai-Bo; Li, Wei-Dong; Liang, Yu-Tie; Liu, Chun-Xiu; Liu, Huai-Min; Liu, Suo; Liu, Ying-Jie; Ma, Qiu-Mei; Ma, Xiang; Mao, Ya-Jun; Mo, Xiao-Hu; Pan, Ming-Hua; Pang, Cai-Ying; Ping, Rong-Gang; Qin, Ya-Hong; Qiu, Jin-Fa; Sun, Sheng-Sen; Sun, Yong-Zhao; Wang, Liang-Liang; Wen, Shuo-Pin; Wu, Ling-Hui; Xie, Yu-Guang; Xu, Min; Yan, Liang; You, Zheng-Yun; Yuan, Chang-Zheng; Yuan, Ye; Zhang, Bing-Yun; Zhang, Chang-Chun; Zhang, Jian-Yong; Zhang, Xue-Yao; Zhang, Yao; Zheng, Yang-Heng; Zhu, Ke-Jun; Zhu, Yong-Sheng; Zhu, Zhi-Li; Zou, Jia-Heng

    2009-10-01

    A track fitting algorithm based on the Kalman filter method has been developed for BESIII of BEPCII. The effects of multiple scattering and energy loss when the charged particles go through the detector, non-uniformity of magnetic field (NUMF) and wire sag, etc., have been carefully handled. This algorithm works well and the performance satisfies the physical requirements tested by the simulation data.

  5. Multiple object tracking using the shortest path faster association algorithm.

    PubMed

    Xi, Zhenghao; Liu, Heping; Liu, Huaping; Yang, Bin

    2014-01-01

    To solve the persistently multiple object tracking in cluttered environments, this paper presents a novel tracking association approach based on the shortest path faster algorithm. First, the multiple object tracking is formulated as an integer programming problem of the flow network. Then we relax the integer programming to a standard linear programming problem. Therefore, the global optimum can be quickly obtained using the shortest path faster algorithm. The proposed method avoids the difficulties of integer programming, and it has a lower worst-case complexity than competing methods but better robustness and tracking accuracy in complex environments. Simulation results show that the proposed algorithm takes less time than other state-of-the-art methods and can operate in real time.

  6. Real-Time Robust Tracking for Motion Blur and Fast Motion via Correlation Filters

    PubMed Central

    Xu, Lingyun; Luo, Haibo; Hui, Bin; Chang, Zheng

    2016-01-01

    Visual tracking has extensive applications in intelligent monitoring and guidance systems. Among state-of-the-art tracking algorithms, Correlation Filter methods perform favorably in robustness, accuracy and speed. However, it also has shortcomings when dealing with pervasive target scale variation, motion blur and fast motion. In this paper we proposed a new real-time robust scheme based on Kernelized Correlation Filter (KCF) to significantly improve performance on motion blur and fast motion. By fusing KCF and STC trackers, our algorithm also solve the estimation of scale variation in many scenarios. We theoretically analyze the problem for CFs towards motions and utilize the point sharpness function of the target patch to evaluate the motion state of target. Then we set up an efficient scheme to handle the motion and scale variation without much time consuming. Our algorithm preserves the properties of KCF besides the ability to handle special scenarios. In the end extensive experimental results on benchmark of VOT datasets show our algorithm performs advantageously competed with the top-rank trackers. PMID:27618046

  7. An enhanced fast scanning algorithm for image segmentation

    NASA Astrophysics Data System (ADS)

    Ismael, Ahmed Naser; Yusof, Yuhanis binti

    2015-12-01

    Segmentation is an essential and important process that separates an image into regions that have similar characteristics or features. This will transform the image for a better image analysis and evaluation. An important benefit of segmentation is the identification of region of interest in a particular image. Various algorithms have been proposed for image segmentation and this includes the Fast Scanning algorithm which has been employed on food, sport and medical images. It scans all pixels in the image and cluster each pixel according to the upper and left neighbor pixels. The clustering process in Fast Scanning algorithm is performed by merging pixels with similar neighbor based on an identified threshold. Such an approach will lead to a weak reliability and shape matching of the produced segments. This paper proposes an adaptive threshold function to be used in the clustering process of the Fast Scanning algorithm. This function used the gray'value in the image's pixels and variance Also, the level of the image that is more the threshold are converted into intensity values between 0 and 1, and other values are converted into intensity values zero. The proposed enhanced Fast Scanning algorithm is realized on images of the public and private transportation in Iraq. Evaluation is later made by comparing the produced images of proposed algorithm and the standard Fast Scanning algorithm. The results showed that proposed algorithm is faster in terms the time from standard fast scanning.

  8. Novel automatic eye detection and tracking algorithm

    NASA Astrophysics Data System (ADS)

    Ghazali, Kamarul Hawari; Jadin, Mohd Shawal; Jie, Ma; Xiao, Rui

    2015-04-01

    The eye is not only one of the most complex but also the most important sensory organ of the human body. Eye detection and eye tracking are basement and hot issue in image processing. A non-invasive eye location and eye tracking is promising for hands-off gaze-based human-computer interface, fatigue detection, instrument control by paraplegic patients and so on. For this purpose, an innovation work frame is proposed to detect and tracking eye in video sequence in this paper. The contributions of this work can be divided into two parts. The first contribution is that eye filters were trained which can detect eye location efficiently and accurately without constraints on the background and skin colour. The second contribution is that a framework of tracker based on sparse representation and LK optic tracker were built which can track eye without constraint on eye status. The experimental results demonstrate the accuracy aspects and the real-time applicability of the proposed approach.

  9. Airborne target tracking algorithm against oppressive decoys in infrared imagery

    NASA Astrophysics Data System (ADS)

    Sun, Xiechang; Zhang, Tianxu

    2009-10-01

    This paper presents an approach for tracking airborne target against oppressive infrared decoys. Oppressive decoy lures infrared guided missile by its high infrared radiation. Traditional tracking algorithms have degraded stability even come to tracking failure when airborne target continuously throw out many decoys. The proposed approach first determines an adaptive tracking window. The center of the tracking window is set at a predicted target position which is computed based on uniform motion model. Different strategies are applied for determination of tracking window size according to target state. The image within tracking window is segmented and multi features of candidate targets are extracted. The most similar candidate target is associated to the tracking target by using a decision function, which calculates a weighted sum of normalized feature differences between two comparable targets. Integrated intensity ratio of association target and tracking target, and target centroid are examined to estimate target state in the presence of decoys. The tracking ability and robustness of proposed approach has been validated by processing available real-world and simulated infrared image sequences containing airborne targets and oppressive decoys.

  10. A Midsize Tokamak As Fast Track To Burning Plasmas

    SciTech Connect

    E. Mazzucato

    2010-07-14

    This paper presents a midsize tokamak as a fast track to the investigation of burning plasmas. It is shown that it could reach large values of energy gain (≥10) with only a modest improvement in confinement over the scaling that was used for designing the International Thermonuclear Experimental Reactor (ITER). This could be achieved by operating in a low plasma recycling regime that experiments indicate can lead to improved plasma confinement. The possibility of reaching the necessary conditions of low recycling using a more efficient magnetic divertor than those of present tokamaks is discussed.

  11. Ultra-Fast Silicon Detectors for 4D tracking

    NASA Astrophysics Data System (ADS)

    Sola, V.; Arcidiacono, R.; Bellora, A.; Cartiglia, N.; Cenna, F.; Cirio, R.; Durando, S.; Ferrero, M.; Galloway, Z.; Gruey, B.; Freeman, P.; Mashayekhi, M.; Mandurrino, M.; Monaco, V.; Mulargia, R.; Obertino, M. M.; Ravera, F.; Sacchi, R.; Sadrozinski, H. F.-W.; Seiden, A.; Spencer, N.; Staiano, A.; Wilder, M.; Woods, N.; Zatserklyaniy, A.

    2017-02-01

    We review the progress toward the development of a novel type of silicon detectors suited for tracking with a picosecond timing resolution, the so called Ultra-Fast Silicon Detectors. The goal is to create a new family of particle detectors merging excellent position and timing resolution with GHz counting capabilities, very low material budget, radiation resistance, fine granularity, low power, insensitivity to magnetic field, and affordability. We aim to achieve concurrent precisions of ~ 10 ps and ~ 10 μm with a 50 μm thick sensor. Ultra-Fast Silicon Detectors are based on the concept of Low-Gain Avalanche Detectors, which are silicon detectors with an internal multiplication mechanism so that they generate a signal which is factor ~ 10 larger than standard silicon detectors.

  12. First results of the silicon telescope using an 'artificial retina' for fast track finding

    SciTech Connect

    Neri, N.; Abba, A.; Caponio, F.; Geraci, A.; Grizzuti, M.; Lusardi, N.; Citterio, M.; Coelli, S.; Fu, J.; Monti, M.; Petruzzo, M.; Bedeschi, F.; Ninci, D.; Piucci, A.; Spinella, F.; Walsh, J.; Cenci, R.; Marino, P.; Morello, M. J.; Stracka, S.; Punzi, G.; Tonelli, D.; Ristori, L.

    2015-07-01

    We present the first results of the prototype of a silicon tracker with trigger capabilities based on a novel approach for fast track finding. The working principle of the 'artificial retina' is inspired by the processing of visual images by the brain and it is based on extensive parallelization of data distribution and pattern recognition. The algorithm has been implemented in commercial FPGAs in three main logic modules: a switch for the routing of the detector hits, a pool of engines for the digital processing of the hits, and a block for the calculation of the track parameters. The architecture is fully pipelined and allows the reconstruction of real-time tracks with a latency less then 100 clock cycles, corresponding to 0.25 microsecond at 400 MHz clock. The silicon telescope consists of 8 layers of single-sided silicon strip detectors with 512 strips each. The detector size is about 10 cm x 10 cm and the strip pitch is 183 μm. The detectors are read out by the Beetle chip, a custom ASICs developed for LHCb, which provides the measurement of the hit position and pulse height of 128 channels. The 'artificial retina' algorithm has been implemented on custom data acquisition boards based on FPGAs Xilinx Kintex 7 lx160. The parameters of the tracks detected are finally transferred to host PC via USB 3.0. The boards manage the read-out ASICs and the sampling of the analog channels. The read-out is performed at 40 MHz on 4 channels for each ASIC that corresponds to a decoding of the telescope information at 1.1 MHz. We report on the first results of the fast tracking device and compare with simulations. (authors)

  13. Infrared image guidance for ground vehicle based on fast wavelet image focusing and tracking

    NASA Astrophysics Data System (ADS)

    Akiyama, Akira; Kobayashi, Nobuaki; Mutoh, Eiichiro; Kumagai, Hideo; Yamada, Hirofumi; Ishii, Hiromitsu

    2009-08-01

    We studied the infrared image guidance for ground vehicle based on the fast wavelet image focusing and tracking. Here we uses the image of the uncooled infrared imager mounted on the two axis gimbal system and the developed new auto focusing algorithm on the Daubechies wavelet transform. The developed new focusing algorithm on the Daubechies wavelet transform processes the result of the high pass filter effect to meet the direct detection of the objects. This new focusing gives us the distance information of the outside world smoothly, and the information of the gimbal system gives us the direction of objects in the outside world to match the sense of the spherical coordinate system. We installed this system on the hand made electric ground vehicle platform powered by 24VDC battery. The electric vehicle equips the rotary encoder units and the inertia rate sensor units to make the correct navigation process. The image tracking also uses the developed newt wavelet focusing within several image processing. The size of the hand made electric ground vehicle platform is about 1m long, 0.75m wide, 1m high, and 50kg weight. We tested the infrared image guidance for ground vehicle based on the new wavelet image focusing and tracking using the electric vehicle indoor and outdoor. The test shows the good results by the developed infrared image guidance for ground vehicle based on the new wavelet image focusing and tracking.

  14. Visual tracking method based on cuckoo search algorithm

    NASA Astrophysics Data System (ADS)

    Gao, Ming-Liang; Yin, Li-Ju; Zou, Guo-Feng; Li, Hai-Tao; Liu, Wei

    2015-07-01

    Cuckoo search (CS) is a new meta-heuristic optimization algorithm that is based on the obligate brood parasitic behavior of some cuckoo species in combination with the Lévy flight behavior of some birds and fruit flies. It has been found to be efficient in solving global optimization problems. An application of CS is presented to solve the visual tracking problem. The relationship between optimization and visual tracking is comparatively studied and the parameters' sensitivity and adjustment of CS in the tracking system are experimentally studied. To demonstrate the tracking ability of a CS-based tracker, a comparative study of tracking accuracy and speed of the CS-based tracker with six "state-of-art" trackers, namely, particle filter, meanshift, PSO, ensemble tracker, fragments tracker, and compressive tracker are presented. Comparative results show that the CS-based tracker outperforms the other trackers.

  15. An object tracking algorithm with embedded gyro information

    NASA Astrophysics Data System (ADS)

    Zhang, Yutong; Yan, Ding; Yuan, Yating

    2017-01-01

    The high speed attitude maneuver of Unmanned Aerial Vehicle (UAV) always causes large motion between adjacent frames of the video stream produced from the camera fixed on the UAV body, which will severely disrupt the performance of image object tracking process. To solve this problem, this paper proposes a method that using a gyroscope fixed on the camera to measure the angular velocity of camera, and then the object position's substantial change in the video stream is predicted. We accomplished the object tracking based on template matching. Experimental result shows that the object tracking algorithm's performance is improved in its efficiency and robustness with embedded gyroscope information.

  16. Geometric Transforms for Fast Geometric Algorithms.

    DTIC Science & Technology

    1979-12-01

    approximation algorithm extends the ideas of the first by defining a transform based on a " pie -slice" diagram and Use Of the floor function. 8.1 .1...2. The second (-approxinate algorithm reduces the time from O(N/(()I/") to O(N + 1 /() by using a tr’nisformu hascd on a " pie -slic e" diagram (Figure...N + 1/).) Bentley, Weide, and Yao [18] have used a simple " pie -slice" diagram for their Voronoi diagram algorithm and Weide [09] has used the floor

  17. X-33 Environmental Impact Statement: A Fast Track Approach

    NASA Technical Reports Server (NTRS)

    McCaleb, Rebecca C.; Holland, Donna L.

    1998-01-01

    NASA is required by the National Environmental Policy Act (NEPA) to prepare an appropriate level environmental analysis for its major projects. Development of the X-33 Technology Demonstrator and its associated flight test program required an environmental impact statement (EIS) under the NEPA. The EIS process is consists of four parts: the "Notice of Intent" to prepare an EIS and scoping; the draft EIS which is distributed for review and comment; the final ETS; and the "Record of Decision." Completion of this process normally takes from 2 - 3 years, depending on the complexity of the proposed action. Many of the agency's newest fast track, technology demonstration programs require NEPA documentation, but cannot sustain the lengthy time requirement between program concept development to implementation. Marshall Space Flight Center, in cooperation with Kennedy Space Center, accomplished the NEPA process for the X-33 Program in 13 months from Notice of Intent to Record of Decision. In addition, the environmental team implemented an extensive public involvement process, conducting a total of 23 public meetings for scoping and draft EIS comment along with numerous informal meetings with public officials, civic organizations, and Native American Indians. This paper will discuss the fast track approach used to successfully accomplish the NEPA process for X-33 on time.

  18. Fast Track intervention effects on youth arrests and delinquency

    PubMed Central

    2010-01-01

    This paper examines the effects of the Fast Track preventive intervention on youth arrests and self-reported delinquent behavior through age 19. High-risk youth randomly assigned to receive a long-term, comprehensive preventive intervention from 1st grade through 10th grade at four sites were compared to high-risk control youth. Findings indicated that random assignment to Fast Track reduced court-recorded juvenile arrest activity based on a severity weighted sum of juvenile arrests. Supplementary analyses revealed an intervention effect on the reduction in the number of court-recorded moderate-severity juvenile arrests, relative to control children. In addition, among youth with higher initial behavioral risk, the intervention reduced the number of high-severity adult arrests relative to the control youth. Survival analyses examining the onset of arrests and delinquent behavior revealed a similar pattern of findings. Intervention decreased the probability of any juvenile arrest among intervention youth not previously arrested. In addition, intervention decreased the probability of a self-reported high-severity offense among youth with no previous self-reported high-severity offense. Intervention effects were also evident on the onset of high-severity court-recorded adult arrests among participants, but these effects varied by site. The current findings suggest that comprehensive preventive intervention can prevent juvenile arrest rates, although the presence and nature of intervention effects differs by outcome. PMID:20577576

  19. Object tracking algorithm based on contextual visual saliency

    NASA Astrophysics Data System (ADS)

    Fu, Bao; Peng, XianRong

    2016-09-01

    As to object tracking, the local context surrounding of the target could provide much effective information for getting a robust tracker. The spatial-temporal context (STC) learning algorithm proposed recently considers the information of the dense context around the target and has achieved a better performance. However STC only used image intensity as the object appearance model. But this appearance model not enough to deal with complicated tracking scenarios. In this paper, we propose a novel object appearance model learning algorithm. Our approach formulates the spatial-temporal relationships between the object of interest and its local context based on a Bayesian framework, which models the statistical correlation between high-level features (Circular-Multi-Block Local Binary Pattern) from the target and its surrounding regions. The tracking problem is posed by computing a visual saliency map, and obtaining the best target location by maximizing an object location likelihood function. Extensive experimental results on public benchmark databases show that our algorithm outperforms the original STC algorithm and other state-of-the-art tracking algorithms.

  20. Solar Load Voltage Tracking for Water Pumping: An Algorithm

    NASA Astrophysics Data System (ADS)

    Kappali, M.; Udayakumar, R. Y.

    2014-07-01

    Maximum power is to be harnessed from solar photovoltaic (PV) panel to minimize the effective cost of solar energy. This is accomplished by maximum power point tracking (MPPT). There are different methods to realise MPPT. This paper proposes a simple algorithm to implement MPPT lv method in a closed loop environment for centrifugal pump driven by brushed PMDC motor. Simulation testing of the algorithm is done and the results are found to be encouraging and supportive of the proposed method MPPT lv .

  1. System and Method for Tracking Vehicles Using Random Search Algorithms.

    DTIC Science & Technology

    1997-01-31

    patent application is available for licensing. Requests for information should be addressed to: OFFICE OF NAVAL RESEARCH DEPARTMENT OF THE NAVY...relates to a system and a method for 22 tracking vehicles using random search algorithm methodolgies . 23 (2) Description of the Prior Art 24 Contact...algorithm methodologies for finding peaks in non-linear 14 functions. U.S. Patent No. 5,148,513 to Koza et al., for 15 example, relates to a non-linear

  2. Cumulative Reconstructor: fast wavefront reconstruction algorithm for Extremely Large Telescopes.

    PubMed

    Rosensteiner, Matthias

    2011-10-01

    The Cumulative Reconstructor (CuRe) is a new direct reconstructor for an optical wavefront from Shack-Hartmann wavefront sensor measurements. In this paper, the algorithm is adapted to realistic telescope geometries and the transition from modified Hudgin to Fried geometry is discussed. After a discussion of the noise propagation, we analyze the complexity of the algorithm. Our numerical tests confirm that the algorithm is very fast and accurate and can therefore be used for adaptive optics systems of Extremely Large Telescopes.

  3. A fast algorithm for image defogging

    NASA Astrophysics Data System (ADS)

    Wang, Xingyu; Guo, Shuai; Wang, Hui; Su, Haibing

    2016-09-01

    For the low visibility and contrast of the foggy image, I propose a single image defogging algorithm. Firstly, change the foggy image from the space of RGB to HSI and divide it into a plurality of blocks. Secondly, elect the maximum point of S component of each block and correct it, keeping H component constant and adjusting I component, so we can estimate fog component through bilinear interpolation. Most importantly, the algorithm deals with the sky region individually. Finally, let the RGB values of all pixels in the blocks minus the fog component and adjust the brightness, so we can obtain the defogging image. Compared with the other algorithms, its efficiency is improved greatly and the image clarity is enhanced. At the same time, the scene is not limited and the scope of application is wide.

  4. Fast tracking of a given heart rate profile in treadmill exercise.

    PubMed

    Weng, Kaili; Turk, Basil; Dolores, Louis; Nguyen, Tuan N; Celler, Branko; Su, Steven; Nguyen, Hung T

    2010-01-01

    This paper investigates the application of a multi-loop PID controller in an automated treadmill exercise machine. The approach is to design a computer-controlled treadmill control system for the regulation of heart rate (HR) during treadmill exercise. A single-input and multiple-output (SIMO) controller was implemented to fast track a given heart rate profile in treadmill exercise. Two separate single-input and single-output (SISO) PID control systems are initially implemented to modify either the treadmill speed or its angle of inclination in order to achieve a desired HR. The purpose of this paper is to apply a SIMO control system by implementing a control algorithm which includes the two PID controllers working simultaneously to track the desired HR profile. The performance of the SIMO and SISO control systems are compared through the closed loop responses recorded during experimentation. This would also help future development of safe treadmill exercise system.

  5. FastDIRC: a fast Monte Carlo and reconstruction algorithm for DIRC detectors

    NASA Astrophysics Data System (ADS)

    Hardin, J.; Williams, M.

    2016-10-01

    FastDIRC is a novel fast Monte Carlo and reconstruction algorithm for DIRC detectors. A DIRC employs rectangular fused-silica bars both as Cherenkov radiators and as light guides. Cherenkov-photon imaging and time-of-propagation information are utilized by a DIRC to identify charged particles. GEANT4-based DIRC Monte Carlo simulations are extremely CPU intensive. The FastDIRC algorithm permits fully simulating a DIRC detector more than 10 000 times faster than using GEANT4. This facilitates designing a DIRC-reconstruction algorithm that improves the Cherenkov-angle resolution of a DIRC detector by ≈ 30% compared to existing algorithms. FastDIRC also greatly reduces the time required to study competing DIRC-detector designs.

  6. Multi-expert tracking algorithm based on improved compressive tracker

    NASA Astrophysics Data System (ADS)

    Feng, Yachun; Zhang, Hong; Yuan, Ding

    2015-12-01

    Object tracking is a challenging task in computer vision. Most state-of-the-art methods maintain an object model and update the object model by using new examples obtained incoming frames in order to deal with the variation in the appearance. It will inevitably introduce the model drift problem into the object model updating frame-by-frame without any censorship mechanism. In this paper, we adopt a multi-expert tracking framework, which is able to correct the effect of bad updates after they happened such as the bad updates caused by the severe occlusion. Hence, the proposed framework exactly has the ability which a robust tracking method should process. The expert ensemble is constructed of a base tracker and its formal snapshot. The tracking result is produced by the current tracker that is selected by means of a simple loss function. We adopt an improved compressive tracker as the base tracker in our work and modify it to fit the multi-expert framework. The proposed multi-expert tracking algorithm significantly improves the robustness of the base tracker, especially in the scenes with frequent occlusions and illumination variations. Experiments on challenging video sequences with comparisons to several state-of-the-art trackers demonstrate the effectiveness of our method and our tracking algorithm can run at real-time.

  7. Fast algorithm for probabilistic bone edge detection (FAPBED)

    NASA Astrophysics Data System (ADS)

    Scepanovic, Danilo; Kirshtein, Joshua; Jain, Ameet K.; Taylor, Russell H.

    2005-04-01

    The registration of preoperative CT to intra-operative reality systems is a crucial step in Computer Assisted Orthopedic Surgery (CAOS). The intra-operative sensors include 3D digitizers, fiducials, X-rays and Ultrasound (US). FAPBED is designed to process CT volumes for registration to tracked US data. Tracked US is advantageous because it is real time, noninvasive, and non-ionizing, but it is also known to have inherent inaccuracies which create the need to develop a framework that is robust to various uncertainties, and can be useful in US-CT registration. Furthermore, conventional registration methods depend on accurate and absolute segmentation. Our proposed probabilistic framework addresses the segmentation-registration duality, wherein exact segmentation is not a prerequisite to achieve accurate registration. In this paper, we develop a method for fast and automatic probabilistic bone surface (edge) detection in CT images. Various features that influence the likelihood of the surface at each spatial coordinate are combined using a simple probabilistic framework, which strikes a fair balance between a high-level understanding of features in an image and the low-level number crunching of standard image processing techniques. The algorithm evaluates different features for detecting the probability of a bone surface at each voxel, and compounds the results of these methods to yield a final, low-noise, probability map of bone surfaces in the volume. Such a probability map can then be used in conjunction with a similar map from tracked intra-operative US to achieve accurate registration. Eight sample pelvic CT scans were used to extract feature parameters and validate the final probability maps. An un-optimized fully automatic Matlab code runs in five minutes per CT volume on average, and was validated by comparison against hand-segmented gold standards. The mean probability assigned to nonzero surface points was 0.8, while nonzero non-surface points had a mean

  8. Genetic algorithm tracking technique for particle image velocimetry and comparison with other tracking models

    SciTech Connect

    Yoon, C.; Hassan, Y.A.; Ortiz-Villafuerte, J.; Schmidl, W.D.

    1996-12-31

    Particle Image Velocimetry (PIV) is a nonintrusive measurement technique, which can be used to study the structure of various fluid flows. PIV is a very efficient measurement technique since it can obtain both qualitative and quantitative spatial information about the flow field being studied. This information can be further processed into information such as vorticity and pathlines. Other flow measurement techniques (Laser Doppler Velocimetry, Hot Wire Anemometry, etc...) only provide quantitative information at a single point. A study on the performance of the Sub-Grid Genetic Tracking Algorithm for use in Particle Image Velocimetry was performed. A comparison with other tracking routines as the Cross Correlation, Spring Model and Neural Network tracking techniques was conducted. All four algorithms were used to track with synthetic data, and the results are compared with those obtained from a Large Eddy simulation computational fluid dynamics program. The simulated vectors were compared with the results from the four tracking techniques, to determine the yield and reliability of each tracking algorithm.

  9. A fast algorithm for numerical solutions to Fortet's equation

    NASA Astrophysics Data System (ADS)

    Brumen, Gorazd

    2008-10-01

    A fast algorithm for computation of default times of multiple firms in a structural model is presented. The algorithm uses a multivariate extension of the Fortet's equation and the structure of Toeplitz matrices to significantly improve the computation time. In a financial market consisting of M[not double greater-than sign]1 firms and N discretization points in every dimension the algorithm uses O(nlogn·M·M!·NM(M-1)/2) operations, where n is the number of discretization points in the time domain. The algorithm is applied to firm survival probability computation and zero coupon bond pricing.

  10. Tracking Southern Hemisphere extratropical cyclones using different algorithms

    NASA Astrophysics Data System (ADS)

    Tilinina, Natalia; Rudeva, Irina; Gulev, Sergey; Simmonds, Ian; Keay, Kevin

    2010-05-01

    We attempt to estimate strengths and weaknesses of the two cyclone tracking algorithms - of the University of Melbourne (UM) and of IORAS (SAIL). The UM scheme is using geostrophic vorticity for tracking cyclones and SAIL tracking is based on sea level pressure. Furthermore, there are many other conceptual differences in the algorithm performance. The SAIL scheme was applied to the NCEP-NCAR reanalysis output for the Southern Hemisphere (1948-2009), the period of intercomparison with the results based on UM scheme was 1990-1999. During time period 1990-1999 the UM scheme identifies 45% more cyclones than the SAIL scheme. The UM tracking output consists of all cyclones which are found by the SAIL scheme and also many short-living vortices, which do not have their imprints in the pressure fields. Many of these vortices are not characterized by the minimum central pressure and the closed isobar - the two major characteristics of cyclone - and require the extension of cyclone definition to be considered as cyclones. Spatial distribution of cyclone counts over Southern Hemisphere clearly shows the two main storm tracks: the Southern (close to the Antarctic) represented by deep and moderate cyclones with minimum central pressure typically lower than 965 hPa and the Northern track primarily associated with the shallow cyclones (central pressure is typically higher than 980hPa). Using the time series of the number of cyclones derived from the SAIL tracking we estimated linear trends in the cyclones counts. The number of deep cyclones (<960 hPa) growths during 1948-2009 by 0,8 cyclones per year, while the number of shallow cyclones (>980 hPa) decreases by 1,3 cyclones per year. Changes in a number of deep cyclones are significantly correlated with the Southern Oscillation Index (e.g. 0,57 in the autumn).

  11. Computer program for fast Karhunen Loeve transform algorithm

    NASA Technical Reports Server (NTRS)

    Jain, A. K.

    1976-01-01

    The fast KL transform algorithm was applied for data compression of a set of four ERTS multispectral images and its performance was compared with other techniques previously studied on the same image data. The performance criteria used here are mean square error and signal to noise ratio. The results obtained show a superior performance of the fast KL transform coding algorithm on the data set used with respect to the above stated perfomance criteria. A summary of the results is given in Chapter I and details of comparisons and discussion on conclusions are given in Chapter IV.

  12. Fast prediction algorithm for multiview video coding

    NASA Astrophysics Data System (ADS)

    Abdelazim, Abdelrahman; Mein, Stephen James; Varley, Martin Roy; Ait-Boudaoud, Djamel

    2013-03-01

    The H.264/multiview video coding (MVC) standard has been developed to enable efficient coding for three-dimensional and multiple viewpoint video sequences. The inter-view statistical dependencies are utilized and an inter-view prediction is employed to provide more efficient coding; however, this increases the overall encoding complexity. Motion homogeneity is exploited here to selectively enable inter-view prediction, and to reduce complexity in the motion estimation (ME) and the mode selection processes. This has been accomplished by defining situations that relate macro-blocks' motion characteristics to the mode selection and the inter-view prediction processes. When comparing the proposed algorithm to the H.264/MVC reference software and other recent work, the experimental results demonstrate a significant reduction in ME time while maintaining similar rate-distortion performance.

  13. Fast algorithm for relaxation processes in big-data systems

    NASA Astrophysics Data System (ADS)

    Hwang, S.; Lee, D.-S.; Kahng, B.

    2014-10-01

    Relaxation processes driven by a Laplacian matrix can be found in many real-world big-data systems, for example, in search engines on the World Wide Web and the dynamic load-balancing protocols in mesh networks. To numerically implement such processes, a fast-running algorithm for the calculation of the pseudoinverse of the Laplacian matrix is essential. Here we propose an algorithm which computes quickly and efficiently the pseudoinverse of Markov chain generator matrices satisfying the detailed-balance condition, a general class of matrices including the Laplacian. The algorithm utilizes the renormalization of the Gaussian integral. In addition to its applicability to a wide range of problems, the algorithm outperforms other algorithms in its ability to compute within a manageable computing time arbitrary elements of the pseudoinverse of a matrix of size millions by millions. Therefore our algorithm can be used very widely in analyzing the relaxation processes occurring on large-scale networked systems.

  14. Patch Based Multiple Instance Learning Algorithm for Object Tracking

    PubMed Central

    2017-01-01

    To deal with the problems of illumination changes or pose variations and serious partial occlusion, patch based multiple instance learning (P-MIL) algorithm is proposed. The algorithm divides an object into many blocks. Then, the online MIL algorithm is applied on each block for obtaining strong classifier. The algorithm takes account of both the average classification score and classification scores of all the blocks for detecting the object. In particular, compared with the whole object based MIL algorithm, the P-MIL algorithm detects the object according to the unoccluded patches when partial occlusion occurs. After detecting the object, the learning rates for updating weak classifiers' parameters are adaptively tuned. The classifier updating strategy avoids overupdating and underupdating the parameters. Finally, the proposed method is compared with other state-of-the-art algorithms on several classical videos. The experiment results illustrate that the proposed method performs well especially in case of illumination changes or pose variations and partial occlusion. Moreover, the algorithm realizes real-time object tracking. PMID:28321248

  15. Patch Based Multiple Instance Learning Algorithm for Object Tracking.

    PubMed

    Wang, Zhenjie; Wang, Lijia; Zhang, Hua

    2017-01-01

    To deal with the problems of illumination changes or pose variations and serious partial occlusion, patch based multiple instance learning (P-MIL) algorithm is proposed. The algorithm divides an object into many blocks. Then, the online MIL algorithm is applied on each block for obtaining strong classifier. The algorithm takes account of both the average classification score and classification scores of all the blocks for detecting the object. In particular, compared with the whole object based MIL algorithm, the P-MIL algorithm detects the object according to the unoccluded patches when partial occlusion occurs. After detecting the object, the learning rates for updating weak classifiers' parameters are adaptively tuned. The classifier updating strategy avoids overupdating and underupdating the parameters. Finally, the proposed method is compared with other state-of-the-art algorithms on several classical videos. The experiment results illustrate that the proposed method performs well especially in case of illumination changes or pose variations and partial occlusion. Moreover, the algorithm realizes real-time object tracking.

  16. "Eztrack": A single-vehicle deterministic tracking algorithm

    SciTech Connect

    Carrano, C J

    2007-12-20

    A variety of surveillance operations require the ability to track vehicles over a long period of time using sequences of images taken from a camera mounted on an airborne or similar platform. In order to be able to see and track a vehicle for any length of time, either a persistent surveillance imager is needed that can image wide fields of view over a long time-span or a highly maneuverable smaller field-of-view imager is needed that can follow the vehicle of interest. The algorithm described here was designed for the persistence surveillance case. In turns out that most vehicle tracking algorithms described in the literature[1,2,3,4] are designed for higher frame rates (> 5 FPS) and relatively short ground sampling distances (GSD) and resolutions ({approx} few cm to a couple tens of cm). But for our datasets, we are restricted to lower resolutions and GSD's ({ge}0.5 m) and limited frame-rates ({le}2.0 Hz). As a consequence, we designed our own simple approach in IDL which is a deterministic, motion-guided object tracker. The object tracking relies both on object features and path dynamics. The algorithm certainly has room for future improvements, but we have found it to be a useful tool in evaluating effects of frame-rate, resolution/GSD, and spectral content (eg. grayscale vs. color imaging ). A block diagram of the tracking approach is given in Figure 1. We describe each of the blocks of the diagram in the upcoming sections.

  17. "Fast Track" and "Traditional Path" Coaches: Affordances, Agency and Social Capital

    ERIC Educational Resources Information Center

    Rynne, Steven

    2014-01-01

    A recent development in large-scale coach accreditation (certification) structures has been the "fast tracking" of former elite athletes. Former elite athletes are often exempted from entry-level qualifications and are generally granted access to fast track courses that are shortened versions of the accreditation courses undertaken by…

  18. Multimode algorithm for detection and tracking of point targets

    NASA Astrophysics Data System (ADS)

    Venkateswarlu, Ronda; Er, Meng H.; Deshpande, Suyog D.; Chan, Philip

    1999-07-01

    This paper deals with the problem of detection and tracking of point-targets from a sequence of IR images against slowly moving clouds as well as structural background. Many algorithms are reported in the literature for tracking sizeable targets with good result. However, the difficulties in tracking point-targets arise from the fact that they are not easily discernible from point like clutter. Though the point-targets are moving, it is very difficult to detect and track them with reduced false alarm rates, because of the non-stationary of the IR clutter, changing target statistics and sensor motion. The focus of research in this area is to reduce false alarm rate to an acceptable level. In certain situations not detecting a true target is acceptable, but declaring a false target as a true one may not be acceptable. Although, there are many approaches to tackle this problem, no single method works well in all the situations. In this paper, we present a multi-mode algorithm involving scene stabilization using image registration, 2D spatial filtering based on continuous wavelet transform, adaptive threshold, accumulation of the threshold frames and processing of the accumulated frame to get the final target trajectories. It is assumed that most of the targets occupy a couple of pixels. Head-on moving and maneuvering targets are not considered. It has been tested successfully with the available database and the results are presented.

  19. A fast directional algorithm for high-frequency electromagnetic scattering

    SciTech Connect

    Tsuji, Paul; Ying Lexing

    2011-06-20

    This paper is concerned with the fast solution of high-frequency electromagnetic scattering problems using the boundary integral formulation. We extend the O(N log N) directional multilevel algorithm previously proposed for the acoustic scattering case to the vector electromagnetic case. We also detail how to incorporate the curl operator of the magnetic field integral equation into the algorithm. When combined with a standard iterative method, this results in an almost linear complexity solver for the combined field integral equations. In addition, the butterfly algorithm is utilized to compute the far field pattern and radar cross section with O(N log N) complexity.

  20. Fast image matching algorithm based on projection characteristics

    NASA Astrophysics Data System (ADS)

    Zhou, Lijuan; Yue, Xiaobo; Zhou, Lijun

    2011-06-01

    Based on analyzing the traditional template matching algorithm, this paper identified the key factors restricting the speed of matching and put forward a brand new fast matching algorithm based on projection. Projecting the grayscale image, this algorithm converts the two-dimensional information of the image into one-dimensional one, and then matches and identifies through one-dimensional correlation, meanwhile, because of normalization has been done, when the image brightness or signal amplitude increasing in proportion, it could also perform correct matching. Experimental results show that the projection characteristics based image registration method proposed in this article could greatly improve the matching speed, which ensuring the matching accuracy as well.

  1. MATLAB tensor classes for fast algorithm prototyping : source code.

    SciTech Connect

    Bader, Brett William; Kolda, Tamara Gibson

    2004-10-01

    We present the source code for three MATLAB classes for manipulating tensors in order to allow fast algorithm prototyping. A tensor is a multidimensional or Nway array. This is a supplementary report; details on using this code are provided separately in SAND-XXXX.

  2. The New Algorithm for Fast Probabilistic Hypocenter Locations

    NASA Astrophysics Data System (ADS)

    Dębski, Wojciech; Klejment, Piotr

    2016-12-01

    The spatial location of sources of seismic waves is one of the first tasks when transient waves from natural (uncontrolled) sources are analysed in many branches of physics, including seismology, oceanology, to name a few. It is well recognised that there is no single universal location algorithm which performs equally well in all situations. Source activity and its spatial variability in time, the geometry of recording network, the complexity and heterogeneity of wave velocity distribution are all factors influencing the performance of location algorithms. In this paper we propose a new location algorithm which exploits the reciprocity and time-inverse invariance property of the wave equation. Basing on these symmetries and using a modern finite-difference-type eikonal solver, we have developed a new very fast algorithm performing the full probabilistic (Bayesian) source location. We illustrate an efficiency of the algorithm performing an advanced error analysis for 1647 seismic events from the Rudna copper mine operating in southwestern Poland.

  3. Fast-convergence superpixel algorithm via an approximate optimization

    NASA Astrophysics Data System (ADS)

    Nakamura, Kensuke; Hong, Byung-Woo

    2016-09-01

    We propose an optimization scheme that achieves fast yet accurate computation of superpixels from an image. Our optimization is designed to improve the efficiency and robustness for the minimization of a composite energy functional in the expectation-minimization (EM) framework where we restrict the update of an estimate to avoid redundant computations. We consider a superpixel energy formulation that consists of L2-norm for the spatial regularity and L1-norm for the data fidelity in the demonstration of the robustness of the proposed algorithm. The quantitative and qualitative evaluations indicate that our superpixel algorithm outperforms SLIC and SEEDS algorithms. It is also demonstrated that our algorithm guarantees the convergence with less computational cost by up to 89% on average compared to the SLIC algorithm while preserving the accuracy. Our optimization scheme can be easily extended to other applications in which the alternating minimization is applicable in the EM framework.

  4. Semisynthetic photoprotein reporters for tracking fast Ca(2+) transients.

    PubMed

    Malikova, Natalia P; Borgdorff, Aren J; Vysotski, Eugene S

    2015-12-01

    Changes in the intracellular concentration of free ionized calcium ([Ca(2+)]i) control a host of cellular processes as varied as vision, muscle contraction, neuronal signal transmission, proliferation, apoptosis etc. The disturbance in Ca(2+)-signaling causes many severe diseases. To understand the mechanisms underlying the control by calcium and how disorder of this regulation relates to pathological conditions, it is necessary to measure [Ca(2+)]i. The Ca(2+)-regulated photoproteins which are responsible for bioluminescence of marine coelenterates have been successfully used for this purpose over the years. Here we report the results on comparative characterization of bioluminescence properties of aequorin from Aequorea victoria, obelin from Obelia longissima, and clytin from Clytia gregaria charged by native coelenterazine and coelenterazine analogues f, i, and hcp. The comparison of specific bioluminescence activity, stability, emission spectra, stopped-flow kinetics, sensitivity to calcium, and effect of physiological concentrations of Mg(2+) establishes obelin-hcp as an excellent semisynthetic photoprotein to keep track of fast intracellular Ca(2+) transients. The rate of rise of its light signal on a sudden change of [Ca(2+)] is almost 3- and 11-fold higher than those of obelin and aequorin with native coelenterazine, respectively, and 20 times higher than that of the corresponding aequorin-hcp. In addition, obelin-hcp preserves a high specific bioluminescence activity and displays higher Ca(2+)-sensitivity as compared to obelin charged by native coelenterazine and sensitivity to Ca(2+) comparable with those of aequorin-f and aequorin-hcp.

  5. Error-Based Observer of a Charge Couple Device Tracking Loop for Fast Steering Mirror

    PubMed Central

    Tang, Tao; Deng, Chao; Yang, Tao; Zhong, Daijun; Ren, Ge; Huang, Yongmei; Fu, Chengyu

    2017-01-01

    The charge couple device (CCD) tracking loop of a fast steering mirror (FSM) is usually used to stabilize line of sight (LOS). High closed-loop bandwidth facilitates good performance. However, low-rate sample and time delay of the CCD greatly limit the high control bandwidth. This paper proposes an error-based observer (EBO) to improve the low-frequency performance of the CCD tracking system. The basic idea is by combining LOS error from the CCD and the controller output to produce the high-gain observer, forwarding into the originally closed-loop control system. This proposed EBO can improve the system both in target tracking and disturbance suppression due to LOS error from the CCD’s sensing of the two signals. From a practical engineering view, the closed-loop stability and robustness of the EBO system are investigated on the condition of gain margin and phase margin of the open-loop transfer function. Two simulations of CCD experiments are provided to verify the benefits of the proposed algorithm. PMID:28264504

  6. Validation of a track repeating algorithm for intensity modulated proton therapy: clinical cases study

    NASA Astrophysics Data System (ADS)

    Yepes, Pablo P.; Eley, John G.; Liu, Amy; Mirkovic, Dragan; Randeniya, Sharmalee; Titt, Uwe; Mohan, Radhe

    2016-04-01

    Monte Carlo (MC) methods are acknowledged as the most accurate technique to calculate dose distributions. However, due its lengthy calculation times, they are difficult to utilize in the clinic or for large retrospective studies. Track-repeating algorithms, based on MC-generated particle track data in water, accelerate dose calculations substantially, while essentially preserving the accuracy of MC. In this study, we present the validation of an efficient dose calculation algorithm for intensity modulated proton therapy, the fast dose calculator (FDC), based on a track-repeating technique. We validated the FDC algorithm for 23 patients, which included 7 brain, 6 head-and-neck, 5 lung, 1 spine, 1 pelvis and 3 prostate cases. For validation, we compared FDC-generated dose distributions with those from a full-fledged Monte Carlo based on GEANT4 (G4). We compared dose-volume-histograms, 3D-gamma-indices and analyzed a series of dosimetric indices. More than 99% of the voxels in the voxelized phantoms describing the patients have a gamma-index smaller than unity for the 2%/2 mm criteria. In addition the difference relative to the prescribed dose between the dosimetric indices calculated with FDC and G4 is less than 1%. FDC reduces the calculation times from 5 ms per proton to around 5 μs.

  7. Validation of a track repeating algorithm for intensity modulated proton therapy: clinical cases study.

    PubMed

    Yepes, Pablo P; Eley, John G; Liu, Amy; Mirkovic, Dragan; Randeniya, Sharmalee; Titt, Uwe; Mohan, Radhe

    2016-04-07

    Monte Carlo (MC) methods are acknowledged as the most accurate technique to calculate dose distributions. However, due its lengthy calculation times, they are difficult to utilize in the clinic or for large retrospective studies. Track-repeating algorithms, based on MC-generated particle track data in water, accelerate dose calculations substantially, while essentially preserving the accuracy of MC. In this study, we present the validation of an efficient dose calculation algorithm for intensity modulated proton therapy, the fast dose calculator (FDC), based on a track-repeating technique. We validated the FDC algorithm for 23 patients, which included 7 brain, 6 head-and-neck, 5 lung, 1 spine, 1 pelvis and 3 prostate cases. For validation, we compared FDC-generated dose distributions with those from a full-fledged Monte Carlo based on GEANT4 (G4). We compared dose-volume-histograms, 3D-gamma-indices and analyzed a series of dosimetric indices. More than 99% of the voxels in the voxelized phantoms describing the patients have a gamma-index smaller than unity for the 2%/2 mm criteria. In addition the difference relative to the prescribed dose between the dosimetric indices calculated with FDC and G4 is less than 1%. FDC reduces the calculation times from 5 ms per proton to around 5 μs.

  8. Making an ED fast track exactly that--fast and efficient.

    PubMed

    Guido, Kathy

    2007-01-01

    Medical facilities must streamline their processes if they want to maintain quality care while reducing costs. In 2005, Benedictine Hospital's struggle to operate more productively, efficiently, and profitably dissipated when it streamlined the administrative process of billing patients for chemotherapy treatments. In 2006, it applied similar changes to effectively treat patients while efficiently processing them through its fast track emergency department. Over the last two decades, The Hudson Valley Technology Development Center (HVTDC) has worked primarily with manufacturing- and technology-based companies to help them adopt new business practices in order to grow and to work more efficiently, effectively, and profitably by streamlining daily operations. In recent years, HVTDC has chosen to introduce the long-established and widely proven principles of lean manufacturing to medical facilities.

  9. Fast Three-Dimensional Single-Particle Tracking in Natural Brain Tissue

    PubMed Central

    Sokoll, Stefan; Prokazov, Yury; Hanses, Magnus; Biermann, Barbara; Tönnies, Klaus; Heine, Martin

    2015-01-01

    Observation of molecular dynamics is often biased by the optical very heterogeneous environment of cells and complex tissue. Here, we have designed an algorithm that facilitates molecular dynamic analyses within brain slices. We adjust fast astigmatism-based three-dimensional single-particle tracking techniques to depth-dependent optical aberrations induced by the refractive index mismatch so that they are applicable to complex samples. In contrast to existing techniques, our online calibration method determines the aberration directly from the acquired two-dimensional image stream by exploiting the inherent particle movement and the redundancy introduced by the astigmatism. The method improves the positioning by reducing the systematic errors introduced by the aberrations, and allows correct derivation of the cellular morphology and molecular diffusion parameters in three dimensions independently of the imaging depth. No additional experimental effort for the user is required. Our method will be useful for many imaging configurations, which allow imaging in deep cellular structures. PMID:26445447

  10. An Application of a Kalman Filter Fixed Interval Smoothing Algorithm to Underwater Target Tracking

    DTIC Science & Technology

    1989-03-01

    FIXED INTERVAL SMOOTHING ALGORITHM TO UNDERWATER TARGET TRACKING 12 Personal Author(s) Richard B. Nicidas 13a Type of Report 13b Time Covered 14 Date of...Terms (cnrln. on e’ rze ifnecessary and idewiify by block number) Field Group Subgroup Kalman Filter, smoothing algorithm, torpedo tracking. 19 Abstract... Smoothing Algorithm to optimally smooth data tracks generated by the short base-line tracking ranges at the Naval Torpedo Station, Keyport, Washington. The

  11. A generic sun-tracking algorithm for on-axis solar collector in mobile platforms

    NASA Astrophysics Data System (ADS)

    Lai, An-Chow; Chong, Kok-Keong; Lim, Boon-Han; Ho, Ming-Cheng; Yap, See-Hao; Heng, Chun-Kit; Lee, Jer-Vui; King, Yeong-Jin

    2015-04-01

    This paper proposes a novel dynamic sun-tracking algorithm which allows accurate tracking of the sun for both non-concentrated and concentrated photovoltaic systems located on mobile platforms to maximize solar energy extraction. The proposed algorithm takes not only the date, time, and geographical information, but also the dynamic changes of coordinates of the mobile platforms into account to calculate the sun position angle relative to ideal azimuth-elevation axes in real time using general sun-tracking formulas derived by Chong and Wong. The algorithm acquires data from open-loop sensors, i.e. global position system (GPS) and digital compass, which are readily available in many off-the-shelf portable gadgets, such as smart phone, to instantly capture the dynamic changes of coordinates of mobile platforms. Our experiments found that a highly accurate GPS is not necessary as the coordinate changes of practical mobile platforms are not fast enough to produce significant differences in the calculation of the incident angle. On the contrary, it is critical to accurately identify the quadrant and angle where the mobile platforms are moving toward in real time, which can be resolved by using digital compass. In our implementation, a noise filtering mechanism is found necessary to remove unexpected spikes in the readings of the digital compass to ensure stability in motor actuations and effectiveness in continuous tracking. Filtering mechanisms being studied include simple moving average and linear regression; the results showed that a compound function of simple moving average and linear regression produces a better outcome. Meanwhile, we found that a sampling interval is useful to avoid excessive motor actuations and power consumption while not sacrificing the accuracy of sun-tracking.

  12. Parallel Detection Algorithm for Fast Frequency Hopping OFDM

    NASA Astrophysics Data System (ADS)

    Kun, Xu; Xiao-xin, Yi

    2011-05-01

    Fast frequency hopping OFDM (FFH-OFDM) exploits frequency diversity in one OFDM symbol to enhance conventional OFDM performance without using channel coding. Zero-forcing (ZF) and minimum mean square error (MMSE) equalization were first used to detect FFH-OFDM signal with a relatively poor bit error rate (BER) performance compared to QR-based detection algorithm. This paper proposes a parallel detection algorithm (PDA) to further improve the BER performance with parallel interference cancelation (PIC) based on MMSE criterion. Our proposed PDA not only improves the BER performance at high signal to noise ratio (SNR) regime but also possesses lower decoding delay property with respect to QR-based detection algorithm while maintaining comparable computation complexity. Simulation results indicate that at BER = 10-3 the PDA achieves 5 dB SNR gain over QR-based detection algorithm and more as SNR increases.

  13. Fast algorithm for transient current through open quantum systems

    NASA Astrophysics Data System (ADS)

    Cheung, King Tai; Fu, Bin; Yu, Zhizhou; Wang, Jian

    2017-03-01

    Transient current calculation is essential to study the response time and capture the peak transient current for preventing meltdown of nanochips in nanoelectronics. Its calculation is known to be extremely time consuming with the best scaling T N3 where N is the dimension of the device and T is the number of time steps. The dynamical response of the system is usually probed by sending a steplike pulse and monitoring its transient behavior. Here, we provide a fast algorithm to study the transient behavior due to the steplike pulse. This algorithm consists of two parts: algorithm I reduces the computational complexity to T0N3 for large systems as long as T algorithm II employs the fast multipole technique and achieves scaling T0N3 whenever T algorithm allows us to tackle many large scale transient problems including magnetic tunneling junctions and ferroelectric tunneling junctions.

  14. 42 CFR 422.626 - Fast-track appeals of service terminations to independent review entities (IREs).

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 42 Public Health 3 2010-10-01 2010-10-01 false Fast-track appeals of service terminations to... Grievances, Organization Determinations and Appeals § 422.626 Fast-track appeals of service terminations to independent review entities (IREs). (a) Enrollee's right to a fast-track appeal of an MA...

  15. 42 CFR 422.626 - Fast-track appeals of service terminations to independent review entities (IREs).

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 42 Public Health 3 2011-10-01 2011-10-01 false Fast-track appeals of service terminations to... Grievances, Organization Determinations and Appeals § 422.626 Fast-track appeals of service terminations to independent review entities (IREs). (a) Enrollee's right to a fast-track appeal of an MA...

  16. Fast polarization-state tracking scheme based on radius-directed linear Kalman filter.

    PubMed

    Yang, Yanfu; Cao, Guoliang; Zhong, Kangping; Zhou, Xian; Yao, Yong; Lau, Alan Pak Tao; Lu, Chao

    2015-07-27

    We propose and experimentally demonstrate a fast polarization tracking scheme based on radius-directed linear Kalman filter. It has the advantages of fast convergence and is inherently insensitive to phase noise and frequency offset effects. The scheme is experimentally compared to conventional polarization tracking methods on the polarization rotation angular frequency. The results show that better tracking capability with more than one order of magnitude improvement is obtained in the cases of polarization multiplexed QPSK and 16QAM signals. The influences of the filter tuning parameters on tracking performance are also investigated in detail.

  17. Tracking algorithms using log-polar mapped image coordinates

    NASA Technical Reports Server (NTRS)

    Weiman, Carl F. R.; Juday, Richard D.

    1990-01-01

    The use of log-polar image sampling coordinates rather than conventional Cartesian coordinates offers a number of advantages for visual tracking and docking of space vehicles. Pixel count is reduced without decreasing the field of view, with commensurate reduction in peripheral resolution. Smaller memory requirements and reduced processing loads are the benefits in working environments where bulk and energy are at a premium. Rotational and zoom symmetries of log-polar coordinates accommodate range and orientation extremes without computational penalties. Separation of radial and rotational coordinates reduces the complexity of several target centering algorithms, described below.

  18. A fast hidden line algorithm for plotting finite element models

    NASA Technical Reports Server (NTRS)

    Jones, G. K.

    1982-01-01

    Effective plotting of finite element models requires the use of fast hidden line plot techniques that provide interactive response. A high speed hidden line technique was developed to facilitate the plotting of NASTRAN finite element models. Based on testing using 14 different models, the new hidden line algorithm (JONES-D) appears to be very fast: its speed equals that for normal (all lines visible) plotting and when compared to other existing methods it appears to be substantially faster. It also appears to be very reliable: no plot errors were observed using the new method to plot NASTRAN models. The new algorithm was made part of the NPLOT NASTRAN plot package and was used by structural analysts for normal production tasks.

  19. Fast wavelet based algorithms for linear evolution equations

    NASA Technical Reports Server (NTRS)

    Engquist, Bjorn; Osher, Stanley; Zhong, Sifen

    1992-01-01

    A class was devised of fast wavelet based algorithms for linear evolution equations whose coefficients are time independent. The method draws on the work of Beylkin, Coifman, and Rokhlin which they applied to general Calderon-Zygmund type integral operators. A modification of their idea is applied to linear hyperbolic and parabolic equations, with spatially varying coefficients. A significant speedup over standard methods is obtained when applied to hyperbolic equations in one space dimension and parabolic equations in multidimensions.

  20. Development of algorithm for single axis sun tracking system

    NASA Astrophysics Data System (ADS)

    Yi, Lim Zi; Singh, Balbir Singh Mahinder; Ching, Dennis Ling Chuan; Jin, Calvin Low Eu

    2016-11-01

    The output power from a solar panel depends on the amount of sunlight that is intercepted by the photovoltaic (PV) solar panel. The value of solar irradiance varies due to the change of position of sun and the local meteorological conditions. This causes the output power of a PV based solar electricity generating system (SEGS) to fluctuate as well. In this paper, the focus is on the integration of solar tracking system with performance analyzer system through the development of an algorithm for optimizing the performance of SEGS. The proposed algorithm displays real-time processed data that would enable users to understand the trend of the SEGS output for maintenance prediction and optimization purposes.

  1. The Block V Receiver fast acquisition algorithm for the Galileo S-band mission

    NASA Technical Reports Server (NTRS)

    Aung, M.; Hurd, W. J.; Buu, C. M.; Berner, J. B.; Stephens, S. A.; Gevargiz, J. M.

    1994-01-01

    A fast acquisition algorithm for the Galileo suppressed carrier, subcarrier, and data symbol signals under low data rate, signal-to-noise ratio (SNR) and high carrier phase-noise conditions has been developed. The algorithm employs a two-arm fast Fourier transform (FFT) method utilizing both the in-phase and quadrature-phase channels of the carrier. The use of both channels results in an improved SNR in the FFT acquisition, enabling the use of a shorter FFT period over which the carrier instability is expected to be less significant. The use of a two-arm FFT also enables subcarrier and symbol acquisition before carrier acquisition. With the subcarrier and symbol loops locked first, the carrier can be acquired from an even shorter FFT period. Two-arm tracking loops are employed to lock the subcarrier and symbol loops parameter modification to achieve the final (high) loop SNR in the shortest time possible. The fast acquisition algorithm is implemented in the Block V Receiver (BVR). This article describes the complete algorithm design, the extensive computer simulation work done for verification of the design and the analysis, implementation issues in the BVR, and the acquisition times of the algorithm. In the expected case of the Galileo spacecraft at Jupiter orbit insertion PD/No equals 14.6 dB-Hz, R(sym) equals 16 symbols per sec, and the predicted acquisition time of the algorithm (to attain a 0.2-dB degradation from each loop to the output symbol SNR) is 38 sec.

  2. Fast algorithm for calculating chemical kinetics in turbulent reacting flow

    NASA Technical Reports Server (NTRS)

    Radhakrishnan, K.; Pratt, D. T.

    1986-01-01

    This paper addresses the need for a fast batch chemistry solver to perform the kinetics part of a split operator formulation of turbulent reacting flows, with special attention focused on the solution of the ordinary differential equations governing a homogeneous gas-phase chemical reaction. For this purpose, a two-part predictor-corrector algorithm which incorporates an exponentially fitted trapezoidal method was developed. The algorithm performs filtering of ill-posed initial conditions, automatic step-size selection, and automatic selection of Jacobi-Newton or Newton-Raphson iteration for convergence to achieve maximum computational efficiency while observing a prescribed error tolerance. The new algorithm, termed CREK1D (combustion reaction kinetics, one-dimensional), compared favorably with the code LSODE when tested on two representative problems drawn from combustion kinetics, and is faster than LSODE.

  3. A fast image encryption algorithm based on chaotic map

    NASA Astrophysics Data System (ADS)

    Liu, Wenhao; Sun, Kehui; Zhu, Congxu

    2016-09-01

    Derived from Sine map and iterative chaotic map with infinite collapse (ICMIC), a new two-dimensional Sine ICMIC modulation map (2D-SIMM) is proposed based on a close-loop modulation coupling (CMC) model, and its chaotic performance is analyzed by means of phase diagram, Lyapunov exponent spectrum and complexity. It shows that this map has good ergodicity, hyperchaotic behavior, large maximum Lyapunov exponent and high complexity. Based on this map, a fast image encryption algorithm is proposed. In this algorithm, the confusion and diffusion processes are combined for one stage. Chaotic shift transform (CST) is proposed to efficiently change the image pixel positions, and the row and column substitutions are applied to scramble the pixel values simultaneously. The simulation and analysis results show that this algorithm has high security, low time complexity, and the abilities of resisting statistical analysis, differential, brute-force, known-plaintext and chosen-plaintext attacks.

  4. Fast stochastic algorithm for simulating evolutionary population dynamics

    NASA Astrophysics Data System (ADS)

    Tsimring, Lev; Hasty, Jeff; Mather, William

    2012-02-01

    Evolution and co-evolution of ecological communities are stochastic processes often characterized by vastly different rates of reproduction and mutation and a coexistence of very large and very small sub-populations of co-evolving species. This creates serious difficulties for accurate statistical modeling of evolutionary dynamics. In this talk, we introduce a new exact algorithm for fast fully stochastic simulations of birth/death/mutation processes. It produces a significant speedup compared to the direct stochastic simulation algorithm in a typical case when the total population size is large and the mutation rates are much smaller than birth/death rates. We illustrate the performance of the algorithm on several representative examples: evolution on a smooth fitness landscape, NK model, and stochastic predator-prey system.

  5. A fast algorithm for sparse matrix computations related to inversion

    SciTech Connect

    Li, S.; Wu, W.; Darve, E.

    2013-06-01

    We have developed a fast algorithm for computing certain entries of the inverse of a sparse matrix. Such computations are critical to many applications, such as the calculation of non-equilibrium Green’s functions G{sup r} and G{sup <} for nano-devices. The FIND (Fast Inverse using Nested Dissection) algorithm is optimal in the big-O sense. However, in practice, FIND suffers from two problems due to the width-2 separators used by its partitioning scheme. One problem is the presence of a large constant factor in the computational cost of FIND. The other problem is that the partitioning scheme used by FIND is incompatible with most existing partitioning methods and libraries for nested dissection, which all use width-1 separators. Our new algorithm resolves these problems by thoroughly decomposing the computation process such that width-1 separators can be used, resulting in a significant speedup over FIND for realistic devices — up to twelve-fold in simulation. The new algorithm also has the added advantage that desired off-diagonal entries can be computed for free. Consequently, our algorithm is faster than the current state-of-the-art recursive methods for meshes of any size. Furthermore, the framework used in the analysis of our algorithm is the first attempt to explicitly apply the widely-used relationship between mesh nodes and matrix computations to the problem of multiple eliminations with reuse of intermediate results. This framework makes our algorithm easier to generalize, and also easier to compare against other methods related to elimination trees. Finally, our accuracy analysis shows that the algorithms that require back-substitution are subject to significant extra round-off errors, which become extremely large even for some well-conditioned matrices or matrices with only moderately large condition numbers. When compared to these back-substitution algorithms, our algorithm is generally a few orders of magnitude more accurate, and our produced round

  6. 77 FR 1697 - Agency Information Collection Activities: Fast Track Generic Clearance for the Collection of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-01-11

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF HEALTH AND HUMAN SERVICES Indian Health Service Agency Information Collection Activities: Fast Track Generic Clearance for the Collection of Qualitative Feedback on Agency Service Delivery: IHS Web Site...

  7. Study of image matching algorithm and sub-pixel fitting algorithm in target tracking

    NASA Astrophysics Data System (ADS)

    Yang, Ming-dong; Jia, Jianjun; Qiang, Jia; Wang, Jian-yu

    2015-03-01

    Image correlation matching is a tracking method that searched a region most approximate to the target template based on the correlation measure between two images. Because there is no need to segment the image, and the computation of this method is little. Image correlation matching is a basic method of target tracking. This paper mainly studies the image matching algorithm of gray scale image, which precision is at sub-pixel level. The matching algorithm used in this paper is SAD (Sum of Absolute Difference) method. This method excels in real-time systems because of its low computation complexity. The SAD method is introduced firstly and the most frequently used sub-pixel fitting algorithms are introduced at the meantime. These fitting algorithms can't be used in real-time systems because they are too complex. However, target tracking often requires high real-time performance, we put forward a fitting algorithm named paraboloidal fitting algorithm based on the consideration above, this algorithm is simple and realized easily in real-time system. The result of this algorithm is compared with that of surface fitting algorithm through image matching simulation. By comparison, the precision difference between these two algorithms is little, it's less than 0.01pixel. In order to research the influence of target rotation on precision of image matching, the experiment of camera rotation was carried on. The detector used in the camera is a CMOS detector. It is fixed to an arc pendulum table, take pictures when the camera rotated different angles. Choose a subarea in the original picture as the template, and search the best matching spot using image matching algorithm mentioned above. The result shows that the matching error is bigger when the target rotation angle is larger. It's an approximate linear relation. Finally, the influence of noise on matching precision was researched. Gaussian noise and pepper and salt noise were added in the image respectively, and the image

  8. A fast marching algorithm for the factored eikonal equation

    NASA Astrophysics Data System (ADS)

    Treister, Eran; Haber, Eldad

    2016-11-01

    The eikonal equation is instrumental in many applications in several fields ranging from computer vision to geoscience. This equation can be efficiently solved using the iterative Fast Sweeping (FS) methods and the direct Fast Marching (FM) methods. However, when used for a point source, the original eikonal equation is known to yield inaccurate numerical solutions, because of a singularity at the source. In this case, the factored eikonal equation is often preferred, and is known to yield a more accurate numerical solution. One application that requires the solution of the eikonal equation for point sources is travel time tomography. This inverse problem may be formulated using the eikonal equation as a forward problem. While this problem has been solved using FS in the past, the more recent choice for applying it involves FM methods because of the efficiency in which sensitivities can be obtained using them. However, while several FS methods are available for solving the factored equation, the FM method is available only for the original eikonal equation. In this paper we develop a Fast Marching algorithm for the factored eikonal equation, using both first and second order finite-difference schemes. Our algorithm follows the same lines as the original FM algorithm and requires the same computational effort. In addition, we show how to obtain sensitivities using this FM method and apply travel time tomography, formulated as an inverse factored eikonal equation. Numerical results in two and three dimensions show that our algorithm solves the factored eikonal equation efficiently, and demonstrate the achieved accuracy for computing the travel time. We also demonstrate a recovery of a 2D and 3D heterogeneous medium by travel time tomography using the eikonal equation for forward modeling and inversion by Gauss-Newton.

  9. Studies of the possibility to use Gas Pixel Detector as a fast trigger tracking device

    NASA Astrophysics Data System (ADS)

    Sinev, N.; Bashindzhagyan, G.; Korotkova, N.; Romaniouk, A.; Tikhomirov, V.

    2016-02-01

    Gas Pixel Detector (GPD) technology offers new possibilities, which make them very attractive for application in existing and future accelerator experiments and beyond. GPDs combine advantages of silicon and gaseous detectors. They can be produced radiation hard and with low power consumption using relatively cheap technology. Low capacitance of the individual pixel channel allows us to obtain a large signal to noise ratio. Using a time projection method for GPD readout one obtains 3D track image with precise coordinate (31 µm) and angular information (0.40°). This feature would allow us to achieve performance of one GPD layer equal to a few layers of silicon detectors. Implementation of a fast readout and data processing at the front-end level allows one to reconstruct a track segment in less than 1 μs, and to use this information for the first level trigger generation. The relevant algorithms of data acquisition and analysis are described and the results of simulations are presented in this paper.

  10. A novel robust and efficient algorithm for charge particle tracking in high background flux

    NASA Astrophysics Data System (ADS)

    Fanelli, C.; Cisbani, E.; Del Dotto, A.

    2015-05-01

    The high luminosity that will be reached in the new generation of High Energy Particle and Nuclear physics experiments implies large high background rate and large tracker occupancy, representing therefore a new challenge for particle tracking algorithms. For instance, at Jefferson Laboratory (JLab) (VA,USA), one of the most demanding experiment in this respect, performed with a 12 GeV electron beam, is characterized by a luminosity up to 1039cm-2s-1. To this scope, Gaseous Electron Multiplier (GEM) based trackers are under development for a new spectrometer that will operate at these high rates in the Hall A of JLab. Within this context, we developed a new tracking algorithm, based on a multistep approach: (i) all hardware - time and charge - information are exploited to minimize the number of hits to associate; (ii) a dedicated Neural Network (NN) has been designed for a fast and efficient association of the hits measured by the GEM detector; (iii) the measurements of the associated hits are further improved in resolution through the application of Kalman filter and Rauch- Tung-Striebel smoother. The algorithm is shortly presented along with a discussion of the promising first results.

  11. A fast algorithm for reordering sparse matrices for parallel factorization

    SciTech Connect

    Lewis, J.G.; Peyton, B.W.; Pothen, A.

    1989-01-01

    Jess and Kees introduced a method for ordering a sparse symmetric matrix A for efficient parallel factorization. The parallel ordering is computed in two steps. First, the matrix A is ordered by some fill-reducing ordering. Second, a parallel ordering of A is computed from the filled graph that results from factoring A using the initial fill-reducing ordering. Among all orderings whose fill lies in the filled graph, this parallel ordering achieves the minimum number of parallel steps in the factorization of A. Jess and Kees did not specify the implementation details of an algorithm for either step of this scheme. Liu and Mirzaian (1987) designed an algorithm implementing the second step, but it has time and space requirements higher than the cost of computing common fill-reducing orderings. We present here a new fast algorithm that implements the parallel ordering step by exploiting the clique tree representation of a chordal graph. We succeed in reducing the cost of the parallel ordering step well below that of the fill-reducing step. Our algorithm has time and space complexity linear in the number of compressed subscripts of L, i.e., the sum of the sizes of the maximal cliques of the filled graph. Empirically we demonstrate running times nearly identical to Liu's heuristic Composite Rotations algorithm that approximates the minimum number of parallel steps. 21 refs., 3 figs., 4 tabs.

  12. A fast contour descriptor algorithm for supernova imageclassification

    SciTech Connect

    Aragon, Cecilia R.; Aragon, David Bradburn

    2006-07-16

    We describe a fast contour descriptor algorithm and its application to a distributed supernova detection system (the Nearby Supernova Factory) that processes 600,000 candidate objects in 80 GB of image data per night. Our shape-detection algorithm reduced the number of false positives generated by the supernova search pipeline by 41% while producing no measurable impact on running time. Fourier descriptors are an established method of numerically describing the shapes of object contours, but transform-based techniques are ordinarily avoided in this type of application due to their computational cost. We devised a fast contour descriptor implementation for supernova candidates that meets the tight processing budget of the application. Using the lowest-order descriptors (F{sub 1} and F{sub -1}) and the total variance in the contour, we obtain one feature representing the eccentricity of the object and another denoting its irregularity. Because the number of Fourier terms to be calculated is fixed and small, the algorithm runs in linear time, rather than the O(n log n) time of an FFT. Constraints on object size allow further optimizations so that the total cost of producing the required contour descriptors is about 4n addition/subtraction operations, where n is the length of the contour.

  13. Fast neutron detection with coincidence counting of recoil tracks in CR-39

    NASA Astrophysics Data System (ADS)

    Lengar, I.; Skvarč, J.; Ilić, R.

    2002-06-01

    Unpredictable background is often the major drawback in the assessment of low fluences of fast neutrons with solid state nuclear track detectors. The problem can be effectively solved by counting coincidence tracks in two detector foils that are in close contact during the irradiation. The detection of fast neutrons performed with a pair of CR-39 detector foils, subsequent chemical etching and evaluation of the etched tracks by an automatic track counting system was studied. After counting, only tracks produced by the same recoil nuclei in the surface layers of both detector foils were taken into account. In this way, the background due to objects that cannot be separated from tracks by an automatic counting system was drastically reduced. Emphasis was given to determining the properties of such a coincidence fast neutron detector based on utilisation of CR-39. The response of the coincidence detector was found to be 3×10 -5 tracks/neutron and is comparable with a detector based on counting tracks in a single foil of CR-39. The lower neutron detection limit was found to be 2×10 4 cm -2 with a counting area of 10 cm 2, and is two orders of magnitude lower than that obtained with a detector based on counting tracks in a single foil of CR-39.

  14. Multifrequency and multidirection optimizations of antenna arrays using heuristic algorithms and the multilevel fast multipole algorithm

    NASA Astrophysics Data System (ADS)

    Önol, Can; Alkış, Sena; Gökçe, Özer; Ergül, Özgür

    2016-07-01

    We consider fast and efficient optimizations of arrays involving three-dimensional antennas with arbitrary shapes and geometries. Heuristic algorithms, particularly genetic algorithms, are used for optimizations, while the required solutions are carried out accurately and efficiently via the multilevel fast multipole algorithm (MLFMA). The superposition principle is employed to reduce the number of MLFMA solutions to the number of array elements per frequency. The developed mechanism is used to optimize arrays for multifrequency and/or multidirection operations, i.e., to find the most suitable set of antenna excitations for desired radiation characteristics simultaneously at different frequencies and/or directions. The capabilities of the optimization environment are demonstrated on arrays of bowtie and Vivaldi antennas.

  15. Detection of a faint fast-moving near-Earth asteroid using the synthetic tracking technique

    SciTech Connect

    Zhai, Chengxing; Shao, Michael; Nemati, Bijan; Werne, Thomas; Zhou, Hanying; Turyshev, Slava G.; Sandhu, Jagmit; Hallinan, Gregg; Harding, Leon K.

    2014-09-01

    We report a detection of a faint near-Earth asteroid (NEA) using our synthetic tracking technique and the CHIMERA instrument on the Palomar 200 inch telescope. With an apparent magnitude of 23 (H = 29, assuming detection at 20 lunar distances), the asteroid was moving at 6.°32 day{sup –1} and was detected at a signal-to-noise ratio (S/N) of 15 using 30 s of data taken at a 16.7 Hz frame rate. The detection was confirmed by a second observation 77 minutes later at the same S/N. Because of its high proper motion, the NEA moved 7 arcsec over the 30 s of observation. Synthetic tracking avoided image degradation due to trailing loss that affects conventional techniques relying on 30 s exposures; the trailing loss would have degraded the surface brightness of the NEA image on the CCD down to an approximate magnitude of 25 making the object undetectable. This detection was a result of our 12 hr blind search conducted on the Palomar 200 inch telescope over two nights, scanning twice over six (5.°3 × 0.°046) fields. Detecting only one asteroid is consistent with Harris's estimates for the distribution of the asteroid population, which was used to predict a detection of 1.2 NEAs in the H-magnitude range 28-31 for the two nights. The experimental design, data analysis methods, and algorithms are presented. We also demonstrate milliarcsecond-level astrometry using observations of two known bright asteroids on the same system with synthetic tracking. We conclude by discussing strategies for scheduling observations to detect and characterize small and fast-moving NEAs using the new technique.

  16. The Fleet Application for Scheduling and Tracking (FAST) Management Website

    NASA Technical Reports Server (NTRS)

    Marrero-Perez, Radames J.

    2014-01-01

    The FAST application was designed to replace the paper and pen method of checking out and checking in GSA Vehicles at KSC. By innovating from a paper and pen based checkout system to a fully digital one, not only the resources wasted by printing the checkout forms have been reduced, but it also reduces significantly the time that users and fleet managers need to interact with the system as well as improving the record accuracy for each vehicle. The vehicle information is pulled from a centralized database server in the SPSDL. In an attempt to add a new feature to the FAST application, the author of this report (alongside the FAST developers) has been designing and developing the FAST Management Website. The GSA fleet managers had to rely on the FAST developers in order to add new vehicles, edit vehicles and previous transactions, or for generating vehicles reports. By providing an easy-to-use FAST Management Website portal, the GSA fleet managers are now able to easily move vehicles, edit records, and print reports.

  17. A Fast Algorithm for Exonic Regions Prediction in DNA Sequences

    PubMed Central

    Saberkari, Hamidreza; Shamsi, Mousa; Heravi, Hamed; Sedaaghi, Mohammad Hossein

    2013-01-01

    The main purpose of this paper is to introduce a fast method for gene prediction in DNA sequences based on the period-3 property in exons. First, the symbolic DNA sequences were converted to digital signal using the electron ion interaction potential method. Then, to reduce the effect of background noise in the period-3 spectrum, we used the discrete wavelet transform at three levels and applied it on the input digital signal. Finally, the Goertzel algorithm was used to extract period-3 components in the filtered DNA sequence. The proposed algorithm leads to decrease the computational complexity and hence, increases the speed of the process. Detection of small size exons in DNA sequences, exactly, is another advantage of the algorithm. The proposed algorithm ability in exon prediction was compared with several existing methods at the nucleotide level using: (i) specificity - sensitivity values; (ii) receiver operating curves (ROC); and (iii) area under ROC curve. Simulation results confirmed that the proposed method can be used as a promising tool for exon prediction in DNA sequences. PMID:24672762

  18. Peak detection in fiber Bragg grating using a fast phase correlation algorithm

    NASA Astrophysics Data System (ADS)

    Lamberti, A.; Vanlanduit, S.; De Pauw, B.; Berghmans, F.

    2014-05-01

    Fiber Bragg grating sensing principle is based on the exact tracking of the peak wavelength location. Several peak detection techniques have already been proposed in literature. Among these, conventional peak detection (CPD) methods such as the maximum detection algorithm (MDA), do not achieve very high precision and accuracy, especially when the Signal to Noise Ratio (SNR) and the wavelength resolution are poor. On the other hand, recently proposed algorithms, like the cross-correlation demodulation algorithm (CCA), are more precise and accurate but require higher computational effort. To overcome these limitations, we developed a novel fast phase correlation algorithm (FPC) which performs as well as the CCA, being at the same time considerably faster. This paper presents the FPC technique and analyzes its performances for different SNR and wavelength resolutions. Using simulations and experiments, we compared the FPC with the MDA and CCA algorithms. The FPC detection capabilities were as precise and accurate as those of the CCA and considerably better than those of the CPD. The FPC computational time was up to 50 times lower than CCA, making the FPC a valid candidate for future implementation in real-time systems.

  19. The ATLAS Fast Tracker and Tracking at the High-Luminosity LHC

    NASA Astrophysics Data System (ADS)

    Ilic, N.

    2017-02-01

    The increase in centre-of-mass energy and luminosity of the Large Hadron Collider makes controlling trigger rates with high efficiency challenging. The ATLAS Fast TracKer is a hardware processor built to reconstruct tracks at a rate of up to 100 kHz and provide them to the high level trigger. The tracker reconstructs tracks by matching incoming detector hits with pre-defined track patterns stored in associative memory on custom ASICs. Inner detector hits are fitted to these track patterns using modern FPGAs. This proceeding describe the electronics system used for the massive parallelization performed by the Fast TracKer. An overview of the installation, commissioning and running of the system is given. The ATLAS upgrades planned to enable tracking at the High-Luminosity Large Hadron Collider are also discussed.

  20. A fast algorithm for finding point sources in the Fermi data stream: FermiFAST

    NASA Astrophysics Data System (ADS)

    Asvathaman, Asha; Omand, Conor; Barton, Alistair; Heyl, Jeremy S.

    2017-04-01

    We present a new and efficient algorithm for finding point sources in the photon event data stream from the Fermi Gamma-Ray Space Telescope, FermiFAST. The key advantage of FermiFAST is that it constructs a catalogue of potential sources very fast by arranging the photon data in a hierarchical data structure. Using this structure, FermiFAST rapidly finds the photons that could have originated from a potential gamma-ray source. It calculates a likelihood ratio for the contribution of the potential source using the angular distribution of the photons within the region of interest. It can find within a few minutes the most significant half of the Fermi Third Point Source catalogue (3FGL) with nearly 80 per cent purity from the 4 yr of data used to construct the catalogue. If a higher purity sample is desirable, one can achieve a sample that includes the most significant third of the Fermi 3FGL with only 5 per cent of the sources unassociated with Fermi sources. Outside the Galactic plane, all but eight of the 580 FermiFAST detections are associated with 3FGL sources. And of these eight, six yield significant detections of greater than 5σ when a further binned likelihood analysis is performed. This software allows for rapid exploration of the Fermi data, simulation of the source detection to calculate the selection function of various sources and the errors in the obtained parameters of the sources detected.

  1. Fast Field Calibration of MIMU Based on the Powell Algorithm

    PubMed Central

    Ma, Lin; Chen, Wanwan; Li, Bin; You, Zheng; Chen, Zhigang

    2014-01-01

    The calibration of micro inertial measurement units is important in ensuring the precision of navigation systems, which are equipped with microelectromechanical system sensors that suffer from various errors. However, traditional calibration methods cannot meet the demand for fast field calibration. This paper presents a fast field calibration method based on the Powell algorithm. As the key points of this calibration, the norm of the accelerometer measurement vector is equal to the gravity magnitude, and the norm of the gyro measurement vector is equal to the rotational velocity inputs. To resolve the error parameters by judging the convergence of the nonlinear equations, the Powell algorithm is applied by establishing a mathematical error model of the novel calibration. All parameters can then be obtained in this manner. A comparison of the proposed method with the traditional calibration method through navigation tests shows the classic performance of the proposed calibration method. The proposed calibration method also saves more time compared with the traditional calibration method. PMID:25177801

  2. Algorithms for High-Speed Noninvasive Eye-Tracking System

    NASA Technical Reports Server (NTRS)

    Talukder, Ashit; Morookian, John-Michael; Lambert, James

    2010-01-01

    Two image-data-processing algorithms are essential to the successful operation of a system of electronic hardware and software that noninvasively tracks the direction of a person s gaze in real time. The system was described in High-Speed Noninvasive Eye-Tracking System (NPO-30700) NASA Tech Briefs, Vol. 31, No. 8 (August 2007), page 51. To recapitulate from the cited article: Like prior commercial noninvasive eyetracking systems, this system is based on (1) illumination of an eye by a low-power infrared light-emitting diode (LED); (2) acquisition of video images of the pupil, iris, and cornea in the reflected infrared light; (3) digitization of the images; and (4) processing the digital image data to determine the direction of gaze from the centroids of the pupil and cornea in the images. Most of the prior commercial noninvasive eyetracking systems rely on standard video cameras, which operate at frame rates of about 30 Hz. Such systems are limited to slow, full-frame operation. The video camera in the present system includes a charge-coupled-device (CCD) image detector plus electronic circuitry capable of implementing an advanced control scheme that effects readout from a small region of interest (ROI), or subwindow, of the full image. Inasmuch as the image features of interest (the cornea and pupil) typically occupy a small part of the camera frame, this ROI capability can be exploited to determine the direction of gaze at a high frame rate by reading out from the ROI that contains the cornea and pupil (but not from the rest of the image) repeatedly. One of the present algorithms exploits the ROI capability. The algorithm takes horizontal row slices and takes advantage of the symmetry of the pupil and cornea circles and of the gray-scale contrasts of the pupil and cornea with respect to other parts of the eye. The algorithm determines which horizontal image slices contain the pupil and cornea, and, on each valid slice, the end coordinates of the pupil and cornea

  3. A fast, robust algorithm for power line interference cancellation in neural recording

    NASA Astrophysics Data System (ADS)

    Keshtkaran, Mohammad Reza; Yang, Zhi

    2014-04-01

    Objective. Power line interference may severely corrupt neural recordings at 50/60 Hz and harmonic frequencies. The interference is usually non-stationary and can vary in frequency, amplitude and phase. To retrieve the gamma-band oscillations at the contaminated frequencies, it is desired to remove the interference without compromising the actual neural signals at the interference frequency bands. In this paper, we present a robust and computationally efficient algorithm for removing power line interference from neural recordings. Approach. The algorithm includes four steps. First, an adaptive notch filter is used to estimate the fundamental frequency of the interference. Subsequently, based on the estimated frequency, harmonics are generated by using discrete-time oscillators, and then the amplitude and phase of each harmonic are estimated by using a modified recursive least squares algorithm. Finally, the estimated interference is subtracted from the recorded data. Main results. The algorithm does not require any reference signal, and can track the frequency, phase and amplitude of each harmonic. When benchmarked with other popular approaches, our algorithm performs better in terms of noise immunity, convergence speed and output signal-to-noise ratio (SNR). While minimally affecting the signal bands of interest, the algorithm consistently yields fast convergence (<100 ms) and substantial interference rejection (output SNR >30 dB) in different conditions of interference strengths (input SNR from -30 to 30 dB), power line frequencies (45-65 Hz) and phase and amplitude drifts. In addition, the algorithm features a straightforward parameter adjustment since the parameters are independent of the input SNR, input signal power and the sampling rate. A hardware prototype was fabricated in a 65 nm CMOS process and tested. Software implementation of the algorithm has been made available for open access at https://github.com/mrezak/removePLI. Significance. The proposed

  4. The first 6 weeks of recovery after primary total hip arthroplasty with fast track

    PubMed Central

    Klapwijk, Lisette C M; Mathijssen, Nina M C; Van Egmond, Jeroen C; Verbeek, Bianca M; Vehmeijer, Stephan B W

    2017-01-01

    Background and purpose Fast-track protocols have been introduced worldwide to improve the recovery after total hip arthroplasty (THA). These protocols have reduced the length of hospital stay (LOS), and THA in an outpatient setting is also feasible. However, less is known regarding the first weeks after THA with fast track. We examined patients’ experiences of the first 6 weeks after hospital discharge following inpatient and outpatient THA with fast track. Patients and methods In a prospective cohort study, 100 consecutive patients who underwent THA surgery in a fast-track setting between February 2015 and October 2015 received a diary for 6 weeks. This diary contained various internationally validated questionnaires including HOOS-PS, OHS, EQ-5D, SF-12, and ICOAP. In addition, there were general questions regarding pain, the wound, physiotherapy, and thrombosis prophylaxis injections. Results 94 patients completed the diary, 42 of whom were operated in an outpatient setting. Pain and use of pain medication had gradually decreased during the 6 weeks. Function and quality of life gradually improved. After 6 weeks, 91% of all patients reported better functioning and less pain than preoperatively. Interpretation Fast track improves early functional outcome, and the PROMs reported during the first 6 weeks in this study showed continued improvement. They can be used as a baseline for future studies. The PROMs reported could also serve as a guide for staff and patients alike to modify expectations and therefore possibly improve patient satisfaction. PMID:28079428

  5. Fast and long term lipid droplet tracking with CARS microscopy.

    PubMed

    Jüngst, Christian; Winterhalder, Martin J; Zumbusch, Andreas

    2011-06-01

    Photobleaching of organic fluorophores commonly used in fluorescence microscopy puts a limit to the number of images which can be acquired. Label-free imaging techniques therefore offer advantages both for rapid image acquisition and for long-term observations. CARS microscopy is a label-free imaging technique offering molecule specific contrast. Here we demonstrate that CARS microscopy allows video-rate tracking of intracellular transport of lipid droplets, but also continuous long-term observation of cells over several hours.

  6. Open-source feature-tracking algorithm for sea ice drift retrieval from Sentinel-1 SAR imagery

    NASA Astrophysics Data System (ADS)

    Muckenhuber, Stefan; Andreevich Korosov, Anton; Sandven, Stein

    2016-04-01

    A computationally efficient, open-source feature-tracking algorithm, called ORB, is adopted and tuned for sea ice drift retrieval from Sentinel-1 SAR (Synthetic Aperture Radar) images. The most suitable setting and parameter values have been found using four Sentinel-1 image pairs representative of sea ice conditions between Greenland and Severnaya Zemlya during winter and spring. The performance of the algorithm is compared to two other feature-tracking algorithms, namely SIFT (Scale-Invariant Feature Transform) and SURF (Speeded-Up Robust Features). Having been applied to 43 test image pairs acquired over Fram Strait and the north-east of Greenland, the tuned ORB (Oriented FAST and Rotated BRIEF) algorithm produces the highest number of vectors (177 513, SIFT: 43 260 and SURF: 25 113), while being computationally most efficient (66 s, SIFT: 182 s and SURF: 99 s per image pair using a 2.7 GHz processor with 8 GB memory). For validation purposes, 314 manually drawn vectors have been compared with the closest calculated vectors, and the resulting root mean square error of ice drift is 563 m. All test image pairs show a significantly better performance of the HV (horizontal transmit, vertical receive) channel due to higher informativeness. On average, around four times as many vectors have been found using HV polarization. All software requirements necessary for applying the presented feature-tracking algorithm are open source to ensure a free and easy implementation.

  7. A versatile pitch tracking algorithm: from human speech to killer whale vocalizations.

    PubMed

    Shapiro, Ari Daniel; Wang, Chao

    2009-07-01

    In this article, a pitch tracking algorithm [named discrete logarithmic Fourier transformation-pitch detection algorithm (DLFT-PDA)], originally designed for human telephone speech, was modified for killer whale vocalizations. The multiple frequency components of some of these vocalizations demand a spectral (rather than temporal) approach to pitch tracking. The DLFT-PDA algorithm derives reliable estimations of pitch and the temporal change of pitch from the harmonic structure of the vocal signal. Scores from both estimations are combined in a dynamic programming search to find a smooth pitch track. The algorithm is capable of tracking killer whale calls that contain simultaneous low and high frequency components and compares favorably across most signal to noise ratio ranges to the peak-picking and sidewinder algorithms that have been used for tracking killer whale vocalizations previously.

  8. Fast Dating Using Least-Squares Criteria and Algorithms.

    PubMed

    To, Thu-Hien; Jung, Matthieu; Lycett, Samantha; Gascuel, Olivier

    2016-01-01

    Phylogenies provide a useful way to understand the evolutionary history of genetic samples, and data sets with more than a thousand taxa are becoming increasingly common, notably with viruses (e.g., human immunodeficiency virus (HIV)). Dating ancestral events is one of the first, essential goals with such data. However, current sophisticated probabilistic approaches struggle to handle data sets of this size. Here, we present very fast dating algorithms, based on a Gaussian model closely related to the Langley-Fitch molecular-clock model. We show that this model is robust to uncorrelated violations of the molecular clock. Our algorithms apply to serial data, where the tips of the tree have been sampled through times. They estimate the substitution rate and the dates of all ancestral nodes. When the input tree is unrooted, they can provide an estimate for the root position, thus representing a new, practical alternative to the standard rooting methods (e.g., midpoint). Our algorithms exploit the tree (recursive) structure of the problem at hand, and the close relationships between least-squares and linear algebra. We distinguish between an unconstrained setting and the case where the temporal precedence constraint (i.e., an ancestral node must be older that its daughter nodes) is accounted for. With rooted trees, the former is solved using linear algebra in linear computing time (i.e., proportional to the number of taxa), while the resolution of the latter, constrained setting, is based on an active-set method that runs in nearly linear time. With unrooted trees the computing time becomes (nearly) quadratic (i.e., proportional to the square of the number of taxa). In all cases, very large input trees (>10,000 taxa) can easily be processed and transformed into time-scaled trees. We compare these algorithms to standard methods (root-to-tip, r8s version of Langley-Fitch method, and BEAST). Using simulated data, we show that their estimation accuracy is similar to that

  9. Fast imaging system and algorithm for monitoring microlymphatics

    NASA Astrophysics Data System (ADS)

    Akl, T.; Rahbar, E.; Zawieja, D.; Gashev, A.; Moore, J.; Coté, G.

    2010-02-01

    The lymphatic system is not well understood and tools to quantify aspects of its behavior are needed. A technique to monitor lymph velocity that can lead to flow, the main determinant of transport, in a near real time manner can be extremely valuable. We recently built a new system that measures lymph velocity, vessel diameter and contractions using optical microscopy digital imaging with a high speed camera (500fps) and a complex processing algorithm. The processing time for a typical data period was significantly reduced to less than 3 minutes in comparison to our previous system in which readings were available 30 minutes after the vessels were imaged. The processing was based on a correlation algorithm in the frequency domain, which, along with new triggering methods, reduced the processing and acquisition time significantly. In addition, the use of a new data filtering technique allowed us to acquire results from recordings that were irresolvable by the previous algorithm due to their high noise level. The algorithm was tested by measuring velocities and diameter changes in rat mesenteric micro-lymphatics. We recorded velocities of 0.25mm/s on average in vessels of diameter ranging from 54um to 140um with phasic contraction strengths of about 6 to 40%. In the future, this system will be used to monitor acute effects that are too fast for previous systems and will also increase the statistical power when dealing with chronic changes. Furthermore, we plan on expanding its functionality to measure the propagation of the contractile activity.

  10. Note: Fast neutron efficiency in CR-39 nuclear track detectors

    SciTech Connect

    Cavallaro, S.

    2015-03-15

    CR-39 samples are commonly employed for fast neutron detection in fusion reactors and in inertial confinement fusion experiments. The literature reported efficiencies are strongly depending on experimental conditions and, in some cases, highly dispersed. The present note analyses the dependence of efficiency as a function of various parameters and experimental conditions in both the radiator-assisted and the stand-alone CR-39 configurations. Comparisons of literature experimental data with Monte Carlo calculations and optimized efficiency values are shown and discussed.

  11. Restoring integrity-A grounded theory of coping with a fast track surgery programme.

    PubMed

    Jørgensen, Lene Bastrup; Fridlund, Bengt

    2016-01-01

    Aims and objectives The aim of this study was to generate a theory conceptualizing and explaining behavioural processes involved in coping in order to identify the predominant coping types and coping type-specific features. Background Patients undergoing fast track procedures do not experience a higher risk of complications, readmission, or mortality. However, such programmes presuppose an increasing degree of patient involvement, placing high educational, physical, and mental demands on the patients. There is a lack of knowledge about how patients understand and cope with fast track programmes. Design The study design used classical grounded theory. Methods The study used a multimodal approach with qualitative and quantitative data sets from 14 patients. Results Four predominant types of coping, with distinct physiological, cognitive, affective, and psychosocial features, existed among patients going through a fast track total hip replacement programme. These patients' main concern was to restore their physical and psychosocial integrity, which had been compromised by reduced function and mobility in daily life. To restore integrity they economized their mental resources, while striving to fulfil the expectations of the fast track programme. This goal was achieved by being mentally proactive and physically active. Three out of the four predominant types of coping matched the expectations expressed in the fast track programme. The non-matching behaviour was seen among the most nervous patients, who claimed the right to diverge from the programme. Conclusion In theory, four predominant types of coping with distinct physiological, cognitive, affective, and psychosocial features occur among patients going through a fast track total hip arthroplasty programme.

  12. Restoring integrity—A grounded theory of coping with a fast track surgery programme

    PubMed Central

    Jørgensen, Lene Bastrup; Fridlund, Bengt

    2016-01-01

    Aims and objectives The aim of this study was to generate a theory conceptualizing and explaining behavioural processes involved in coping in order to identify the predominant coping types and coping type-specific features. Background Patients undergoing fast track procedures do not experience a higher risk of complications, readmission, or mortality. However, such programmes presuppose an increasing degree of patient involvement, placing high educational, physical, and mental demands on the patients. There is a lack of knowledge about how patients understand and cope with fast track programmes. Design The study design used classical grounded theory. Methods The study used a multimodal approach with qualitative and quantitative data sets from 14 patients. Results Four predominant types of coping, with distinct physiological, cognitive, affective, and psychosocial features, existed among patients going through a fast track total hip replacement programme. These patients’ main concern was to restore their physical and psychosocial integrity, which had been compromised by reduced function and mobility in daily life. To restore integrity they economized their mental resources, while striving to fulfil the expectations of the fast track programme. This goal was achieved by being mentally proactive and physically active. Three out of the four predominant types of coping matched the expectations expressed in the fast track programme. The non-matching behaviour was seen among the most nervous patients, who claimed the right to diverge from the programme. Conclusion In theory, four predominant types of coping with distinct physiological, cognitive, affective, and psychosocial features occur among patients going through a fast track total hip arthroplasty programme. PMID:26751199

  13. Fast Variable Structure Stochastic Automaton for Discovering and Tracking Spatiotemporal Event Patterns.

    PubMed

    Zhang, Junqi; Wang, Yuheng; Wang, Cheng; Zhou, MengChu

    2017-04-05

    Discovering and tracking spatiotemporal event patterns have many applications. For example, in a smart-home project, a set of spatiotemporal pattern learning automata are used to monitor a user's repetitive activities, by which the home's automaticity can be promoted while some of his/her burdens can be reduced. Existing algorithms for spatiotemporal event pattern recognition in dynamic noisy environment are based on fixed structure stochastic automata whose state transition function is fixed and predesigned to guarantee their immunity to noise. However, such design is conservative because it needs continuous and identical feedbacks to converge, thus leading to its very low convergence rate. In many real-life applications, such as ambient assisted living, consecutive nonoccurrences of an elder resident's routine activities should be treated with an alert as quickly as possible. On the other hand, no alert should be output even for some occurrences in order to diminish the effects caused by noise. Clearly, confronting a pattern's change, slow speed and low accuracy may degrade a user's life security. This paper proposes a fast and accurate leaning automaton based on variable structure stochastic automata to satisfy the realistic requirements for both speed and accuracy. Bias toward alert is necessary for elder residents while the existing method can only support the bias toward ``no alert.'' This paper introduces a method to allow bias toward alert or no alert to meet a user's specific bias requirement. Experimental results show its better performance than the state-of-the-art methods.

  14. Track gauge optimisation of railway switches using a genetic algorithm

    NASA Astrophysics Data System (ADS)

    Pålsson, Björn A.; Nielsen, Jens C. O.

    2012-01-01

    A methodology for the optimisation of a prescribed track gauge variation (gauge widening) in the switch panel of a railway turnout (switch and crossing, S&C) is presented. The aim is to reduce rail profile degradation. A holistic approach is applied, where both routes and travel directions (moves) of traffic in the switch panel are considered simultaneously. The problem is formulated as a multi-objective minimisation problem which is solved using a genetic-type optimisation algorithm which provides a set of Pareto optimal solutions. The dynamic vehicle-turnout interaction is evaluated using a multi-body simulation tool and the energy dissipation in the wheel-rail contacts is used for the assessment of gauge parameters. Two different vehicle models are used, one freight car and one passenger train set, and a stochastic spread in wheel profile and wheel-rail friction coefficient is accounted for. It is found that gauge configurations with a large gauge-widening amplitude for the stock rail on the field side are optimal for both the through and diverging routes, while the results for the gauge side show a larger route dependence. The optimal gauge configurations are observed to be similar for both vehicle types.

  15. Research on video target tracking technology based on improved SIFT algorithm

    NASA Astrophysics Data System (ADS)

    Zhuang, Zhemin; Guo, Zhijie; Yuang, Ye

    2017-01-01

    A novel target tracking algorithm based on improved SIFT (Scale Invariant Feature Transform (SIFT) algorithm is proposed in this paper. In order to improve real-time performance, the processing neighborhood of SIFT has been improved to decrease the complexity of calculation, and the dimension of the SIFT vector is set from 128 to 40. Simulations and experiments show this improved algorithm brings us low computation complexity and high tracking accuracy and robustness.

  16. Tracking at CDF: algorithms and experience from Run I and Run II

    SciTech Connect

    Snider, F.D.; /Fermilab

    2005-10-01

    The authors describe the tracking algorithms used during Run I and Run II by CDF at the Fermilab Tevatron Collider, covering the time from about 1992 through the present, and discuss the performance of the algorithms at high luminosity. By tracing the evolution of the detectors and algorithms, they reveal some of the successful strategies used by CDF to address the problems of tracking at high luminosities.

  17. A simple backscattering microscope for fast tracking of biological molecules

    NASA Astrophysics Data System (ADS)

    Sowa, Yoshiyuki; Steel, Bradley C.; Berry, Richard M.

    2010-11-01

    Recent developments in techniques for observing single molecules under light microscopes have helped reveal the mechanisms by which molecular machines work. A wide range of markers can be used to detect molecules, from single fluorophores to micron sized markers, depending on the research interest. Here, we present a new and simple objective-type backscattering microscope to track gold nanoparticles with nanometer and microsecond resolution. The total noise of our system in a 55 kHz bandwidth is ˜0.6 nm per axis, sufficient to measure molecular movement. We found our backscattering microscopy to be useful not only for in vitro but also for in vivo experiments because of lower background scattering from cells than in conventional dark-field microscopy. We demonstrate the application of this technique to measuring the motion of a biological rotary molecular motor, the bacterial flagellar motor, in live Escherichia coli cells.

  18. Measuring fast-neutron flux by track-etch technique

    SciTech Connect

    Not Available

    1981-01-01

    The method covers the measurement of neutron flux by the use of fissionable materials. Fission fragments emitted by the fissionable materials during neutron bombardment penetrate a suitable recording medium, such as plastic, glass, or mica, that is in contact with the fissionable material. Appropriate etching techniques render the path of the fragment in the recording medium visible under an optical microscope. Since measurement of the decay of radioisotopes is not involved in this method, irradiation times are limited only by the maximum number of fission fragment tracks that can be clearly distinguished without pile up: approximately 2 x 10/sup 5//cm/sup 2/. The method includes a discussion of apparatus, reagents and materials, procedure, calculations, precision, and accuracy. (JMT)

  19. Tracking Changing Environments: Innovators Are Fast, but Not Flexible Learners

    PubMed Central

    Griffin, Andrea S.; Guez, David; Lermite, Françoise; Patience, Madeleine

    2013-01-01

    Behavioural innovations are increasingly thought to provide a rich source of phenotypic plasticity and evolutionary change. Innovation propensity shows substantial variation across avian taxa and provides an adaptive mechanism by which behaviour is flexibly adjusted to changing environmental conditions. Here, we tested for the first time the prediction that inter-individual variation in innovation propensity is equally a measure of behavioural flexibility. We used Indian mynas, Sturnus tristis, a highly successful worldwide invader. Results revealed that mynas that solved an extractive foraging task more quickly learnt to discriminate between a cue that predicted food, and one that did not more quickly. However, fast innovators were slower to change their behaviour when the significance of the food cues changed. This unexpected finding appears at odds with the well-established view that avian taxa with larger brains relative to their body size, and therefore greater neural processing power, are both faster, and more flexible learners. We speculate that the existence of this relationship across taxa can be reconciled with its absence within species by assuming that fast, innovative learners and non innovative, slow, flexible learners constitute two separate individual strategies, which are both underpinned by enhanced neural processing power. This idea is consistent with the recent proposal that individuals may differ consistently in ‘cognitive style’, differentially trading off speed against accuracy in cognitive tasks. PMID:24391981

  20. A fast heuristic algorithm for a probe mapping problem.

    PubMed

    Mumey, B

    1997-01-01

    A new heuristic algorithm is presented for mapping probes to locations along the genome, given noisy pairwise distance data as input. The model considered is quite general: The input consists of a collection of probe pairs and a confidence interval for the genomic distance separating each pair. Because the distance intervals are only known with some confidence level, some may be erroneous and must be removed in order to find a consistent map. A novel randomized technique for detecting and removing bad distance intervals is described. The technique could be useful in other contexts where partially erroneous data is inconsistent with the remaining data. These algorithms were motivated by the goal of making probe maps with inter-probe distance confidence intervals estimated from fluorescence in-situ hybridization (FISH) experiments. Experimentation was done on synthetic data sets (with and without errors) and FISH data from a region of human chromosome 4. Problems with up to 100 probes could be solved in several minutes on a fast workstation. In addition to FISH mapping, we describe some other possible applications that fall within the problem model. These include: mapping a backbone structure in folded DNA, finding consensus maps between independent maps covering the same genomic region, and ordering clones in a clone library.

  1. Fast pulse detection algorithms for digitized waveforms from scintillators

    NASA Astrophysics Data System (ADS)

    Krasilnikov, V.; Marocco, D.; Esposito, B.; Riva, M.; Kaschuck, Yu.

    2011-03-01

    Advanced C++ programming methods as well as fast Pulse Detection Algorithms (PDA) have been implemented in order to increase the computing speed of a LabVIEW™ data processing software developed for a Digital Pulse Shape Discrimination (DPSD) system for liquid scintillators. The newly implemented PDAs are described and compared: the most efficient method has been implemented in the data processing software, which has also been ported into C++. The comparison of the computing speeds of the new and old versions of the PDAs are presented. Program summaryProgram title: DPDS - Digital Pulse Detection Software Catalogue identifier: AEHQ_v1_0 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AEHQ_v1_0.html Program obtainable from: CPC Program Library, Queen's University, Belfast, N. Ireland Licensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.html No. of lines in distributed program, including test data, etc.: 454 070 No. of bytes in distributed program, including test data, etc.: 20 987 104 Distribution format: tar.gz Programming language: C++ (Borland Visual C++) Computer: IBM PC Operating system: MS Windows 2000 and later… RAM: <50 Mbytes, highly depends on settings Classification: 4.12 External routines: Only standard Borland Visual C++ libraries Nature of problem: A very slow pulse detection algorithm, used as standard in LABView, is preventing the ability to process achieved data during the pause between plasma discharges in modern tokamaks. Solution method: Simple yet precise pulse detection algorithms implemented and the whole data processing software translated from LABView into C++. This speeded up the elaboration up to 30 times. Restrictions: Windows system decimal separator must be ".", not ",". Additional comments: Processing 300 MB data file should not take longer then 10 minutes. Running time: From 1 minute to 1 hour.

  2. Passive radar tracking of a maneuvering target using variable structure multiple-model algorithm

    NASA Astrophysics Data System (ADS)

    Mao, Yunxiang; Zhou, Xiaohui; Zhang, Jin

    2013-03-01

    The variable structure multiple-model (VSMM) algorithm to passive radar maneuvering target tracking problem is considered. A new VSMM design, expected mode augmentation based on likely model set (LMS-EMA) algorithm is presented. The LMS-EMA algorithm adaptively determines the fixed grid model set using likely model set (LMS) algorithm, and generates the expected mode based on this set. Then, the union of fixed grid model set and expected model is used to perform multiple-model estimation. The performance of the LMS-EMA algorithm is evaluated via simulation of a highly maneuvering target tracking problem.

  3. Fast Flux Test Facility Asbestos Location Tracking Program

    SciTech Connect

    REYNOLDS, J.A.

    1999-04-13

    Procedure Number HNF-PRO-408, revision 0, paragraph 1.0, ''Purpose,'' and paragraph 2.0, ''Requirements for Facility Management of Asbestos,'' relate building inspection and requirements for documentation of existing asbestos-containing building material (ACBM) per each building assessment. This documentation shall be available to all personnel (including contractor personnel) entering the facility at their request. Corrective action was required by 400 Area Integrated Annual Appraisal/Audit for Fiscal Year 1992 (IAA-92-0007) to provide this notification documentation. No formal method had been developed to communicate the location and nature of ACBM to maintenance personnel in the Fast Flux Test Facility (FFTF) 400 Area. The scope of this Data Package Document is to locate and evaluate any ACBM found at FFTF which constitutes a baseline. This includes all buildings within the protected area. These findings are compiled from earlier reports, numerous work packages and engineering evaluations of employee findings.

  4. L1Track: A fast Level 1 track trigger for the ATLAS high luminosity upgrade

    NASA Astrophysics Data System (ADS)

    Cerri, Alessandro

    2016-07-01

    With the planned high-luminosity upgrade of the LHC (HL-LHC), the ATLAS detector will see its collision rate increase by approximately a factor of 5 with respect to the current LHC operation. The earliest hardware-based ATLAS trigger stage ("Level 1") will have to provide a higher rejection factor in a more difficult environment: a new improved Level 1 trigger architecture is under study, which includes the possibility of extracting with low latency and high accuracy tracking information in time for the decision taking process. In this context, the feasibility of potential approaches aimed at providing low-latency high-quality tracking at Level 1 is discussed.

  5. The research of moving objects behavior detection and tracking algorithm in aerial video

    NASA Astrophysics Data System (ADS)

    Yang, Le-le; Li, Xin; Yang, Xiao-ping; Li, Dong-hui

    2015-12-01

    The article focuses on the research of moving target detection and tracking algorithm in Aerial monitoring. Study includes moving target detection, moving target behavioral analysis and Target Auto tracking. In moving target detection, the paper considering the characteristics of background subtraction and frame difference method, using background reconstruction method to accurately locate moving targets; in the analysis of the behavior of the moving object, using matlab technique shown in the binary image detection area, analyzing whether the moving objects invasion and invasion direction; In Auto Tracking moving target, A video tracking algorithm that used the prediction of object centroids based on Kalman filtering was proposed.

  6. New Medical-School Programs Put Students on a Fast Track to the White Coat

    ERIC Educational Resources Information Center

    Mangan, Katherine

    2009-01-01

    California's lieutenant governor has proposed a fast-track medical school that would shave three years off the training needed to become a physician. It is not the first time such an idea has been offered. The proposal, for a hoped-for medical school at the University of California at Merced, struck some medical educators as both unrealistic and…

  7. The Effects of the Fast Track Preventive Intervention on the Development of Conduct Disorder across Childhood

    ERIC Educational Resources Information Center

    Child Development, 2011

    2011-01-01

    The impact of the Fast Track intervention on externalizing disorders across childhood was examined. Eight hundred-ninety-one early-starting children (69% male; 51% African American) were randomly assigned by matched sets of schools to intervention or control conditions. The 10-year intervention addressed parent behavior-management, child social…

  8. Fast Track Randomized Controlled Trial to Prevent Externalizing Psychiatric Disorders: Findings from Grades 3 to 9

    ERIC Educational Resources Information Center

    Journal of the American Academy of Child & Adolescent Psychiatry, 2007

    2007-01-01

    Objective: This study tests the efficacy of the Fast Track Program in preventing antisocial behavior and psychiatric disorders among groups varying in initial risk. Method: Schools within four sites (Durham, NC; Nashville, TN; Seattle, WA; and rural central Pennsylvania) were selected as high-risk institutions based on neighborhood crime and…

  9. Private health insurance in Sweden: Fast-track lanes and the alleged attempts to stop them.

    PubMed

    Lapidus, John

    2017-04-01

    According to the Health and Medical Services Act (1982:763), those who have the greatest need for healthcare shall be given priority. This is being challenged by the rapid emergence of private health insurance which increases the share of private funding and creates fast-track lanes where some people get faster access to healthcare than others. The Stop Law, implemented by a Social Democratic government in 2006, was generally regarded as a way to put an end to the fast-track lanes in Swedish healthcare. Based on a thorough examination of the law and its legislative history - official reports, propositions, comments on official reports - this article argues that the Stop Law was so full of exceptions and loopholes that it did not threaten the existence of fast-track lanes. The same goes for a similar Social Democratic proposal from 2016, which is also examined in the article. Further, the article analyses centre-right wing positions on fast-track lanes in Swedish healthcare. In summary, it is argued that politicians of all stripes have allowed the development to proceed in spite of unanimous support for the idea that Swedish healthcare shall be provided to all on equal terms.

  10. The Status of Girls' Education in Education for All Fast Track Initiative Partner Countries

    ERIC Educational Resources Information Center

    Clarke, Prema

    2011-01-01

    This viewpoint examines girls' performance in primary education in the countries that joined the Education for All Fast Track Initiative between 2002 and 2008. At the time they joined the initiative, a first group of countries (high performers) had already achieved high and equal enrollment of girls and boys. Significant progress is evident in a…

  11. Tracking Algorithm of Multiple Pedestrians Based on Particle Filters in Video Sequences

    PubMed Central

    Liu, Yun; Wang, Chuanxu; Zhang, Shujun; Cui, Xuehong

    2016-01-01

    Pedestrian tracking is a critical problem in the field of computer vision. Particle filters have been proven to be very useful in pedestrian tracking for nonlinear and non-Gaussian estimation problems. However, pedestrian tracking in complex environment is still facing many problems due to changes of pedestrian postures and scale, moving background, mutual occlusion, and presence of pedestrian. To surmount these difficulties, this paper presents tracking algorithm of multiple pedestrians based on particle filters in video sequences. The algorithm acquires confidence value of the object and the background through extracting a priori knowledge thus to achieve multipedestrian detection; it adopts color and texture features into particle filter to get better observation results and then automatically adjusts weight value of each feature according to current tracking environment. During the process of tracking, the algorithm processes severe occlusion condition to prevent drift and loss phenomena caused by object occlusion and associates detection results with particle state to propose discriminated method for object disappearance and emergence thus to achieve robust tracking of multiple pedestrians. Experimental verification and analysis in video sequences demonstrate that proposed algorithm improves the tracking performance and has better tracking results. PMID:27847514

  12. Tracking Algorithm of Multiple Pedestrians Based on Particle Filters in Video Sequences.

    PubMed

    Li, Hui; Liu, Yun; Wang, Chuanxu; Zhang, Shujun; Cui, Xuehong

    2016-01-01

    Pedestrian tracking is a critical problem in the field of computer vision. Particle filters have been proven to be very useful in pedestrian tracking for nonlinear and non-Gaussian estimation problems. However, pedestrian tracking in complex environment is still facing many problems due to changes of pedestrian postures and scale, moving background, mutual occlusion, and presence of pedestrian. To surmount these difficulties, this paper presents tracking algorithm of multiple pedestrians based on particle filters in video sequences. The algorithm acquires confidence value of the object and the background through extracting a priori knowledge thus to achieve multipedestrian detection; it adopts color and texture features into particle filter to get better observation results and then automatically adjusts weight value of each feature according to current tracking environment. During the process of tracking, the algorithm processes severe occlusion condition to prevent drift and loss phenomena caused by object occlusion and associates detection results with particle state to propose discriminated method for object disappearance and emergence thus to achieve robust tracking of multiple pedestrians. Experimental verification and analysis in video sequences demonstrate that proposed algorithm improves the tracking performance and has better tracking results.

  13. A guidance and control algorithm for scent tracking micro-robotic vehicle swarms

    SciTech Connect

    Dohner, J.L.

    1998-03-01

    Cooperative micro-robotic scent tracking vehicles are designed to collectively sniff out locations of high scent concentrations in unknown, geometrically complex environments. These vehicles are programmed with guidance and control algorithms that allow inter cooperation among vehicles. In this paper a cooperative guidance and control algorithm for scent tracking micro-robotic vehicles is presented. This algorithm is comprised of a sensory compensation sub-algorithm using point source cancellation, a guidance sub-algorithm using gradient descent tracking, and a control sub-algorithm using proportional feedback. The concepts of social rank and point source cancellation are new concepts introduced within. Simulation results for cooperative vehicles swarms are given. Limitations are discussed.

  14. A new fast algorithm for computing a complex number: Theoretic transforms

    NASA Technical Reports Server (NTRS)

    Reed, I. S.; Liu, K. Y.; Truong, T. K.

    1977-01-01

    A high-radix fast Fourier transformation (FFT) algorithm for computing transforms over GF(sq q), where q is a Mersenne prime, is developed to implement fast circular convolutions. This new algorithm requires substantially fewer multiplications than the conventional FFT.

  15. Fast neutrons detection in CR-39 and DAM-ADC nuclear track detectors

    NASA Astrophysics Data System (ADS)

    Abdalla, A. M.; Ashraf, O.; Rammah, Y. S.; Ashry, A. H.; Eisa, M.; Tsuruta, T.

    2015-03-01

    Fast detection of neutrons in CR-39 and DAM-ADC nuclear track detectors were investigated using new etching conditions. The neutron irradiation is performed using a 5 mCi Am-Be source present at the National Institute of Standards (NIS) of Egypt. Using the new etching condition, irradiated CR-39 samples were etched for 4 h and DAM-ADC samples for 80 min. Suitable analyzing software has been used to analyze experimental data.The dependence of neutrons track density on the neutrons fluence is investigated. When etched under optimum conditions, the relationship between track density and fluence is determined which is found to be linear. Detection efficiency has been represented for both SSNTDs and found to be constant with fluence, which reflects the importance of using CR-39 and DAM-ADC detectors in the field of neutron dosimetry. Linear relationship between track density and effective dose is determined.

  16. Modal analysis of rotating plate using tracking laser Doppler vibrometer: algorithm modification

    NASA Astrophysics Data System (ADS)

    Khalil, Hossam; Kim, Dongkyu; Nam, Joonsik; Park, Kyihwan

    2015-07-01

    A modified algorithm for tracking laser Doppler vibrometer (TLDV) is introduced to measure the vibration of rotating objects. The proposed algorithm unlike the old algorithm for TLDV can be used when the speed of the object to be tracked varies continuously or alternating in a small range. The proposed algorithm is to use encoder only as a position sensor. The position from the encoder is used to calculate the driving signals to the galvanometers. To verify the proposed method, experimental modal analysis of the circular plate in stationary and rotating cases are made.

  17. A fast algorithm for estimating actions in triaxial potentials

    NASA Astrophysics Data System (ADS)

    Sanders, Jason L.; Binney, James

    2015-03-01

    We present an approach to approximating rapidly the actions in a general triaxial potential. The method is an extension of the axisymmetric approach presented by Binney, and operates by assuming that the true potential is locally sufficiently close to some Stäckel potential. The choice of Stäckel potential and associated ellipsoidal coordinates is tailored to each individual input phase-space point. We investigate the accuracy of the method when computing actions in a triaxial Navarro-Frenk-White potential. The speed of the algorithm comes at the expense of large errors in the actions, particularly for the box orbits. However, we show that the method can be used to recover the observables of triaxial systems from given distribution functions to sufficient accuracy for the Jeans equations to be satisfied. Consequently, such models could be used to build models of external galaxies as well as triaxial components of our own Galaxy. When more accurate actions are required, this procedure can be combined with torus mapping to produce a fast convergent scheme for action estimation.

  18. Geometry-Of-Fire Tracking Algorithm for Direct-Fire Weapon Systems

    DTIC Science & Technology

    2015-09-01

    TRACKING ALGORITHM FOR DIRECT -FIRE WEAPON SYSTEMS by Caleb K. Khan September 2015 Thesis Advisor: Zachary Staples Co-Advisor: Xiaoping...2015 3. REPORT TYPE AND DATES COVERED Master’s Thesis 4. TITLE AND SUBTITLE GEOMETRY-OF-FIRE TRACKING ALGORITHM FOR DIRECT -FIRE WEAPON SYSTEMS... direct -fire weapon systems. This is the first attempt to develop technology for this specific application. Prototyping the system’s overall design

  19. Optimal Local Searching for Fast and Robust Textureless 3D Object Tracking in Highly Cluttered Backgrounds.

    PubMed

    Seo, Byung-Kuk; Park, Jong-Il; Hinterstoisser, Stefan; Ilic, Slobodan

    2013-06-13

    Edge-based tracking is a fast and plausible approach for textureless 3D object tracking, but its robustness is still very challenging in highly cluttered backgrounds due to numerous local minima. To overcome this problem, we propose a novel method for fast and robust textureless 3D object tracking in highly cluttered backgrounds. The proposed method is based on optimal local searching of 3D-2D correspondences between a known 3D object model and 2D scene edges in an image with heavy background clutter. In our searching scheme, searching regions are partitioned into three levels (interior, contour, and exterior) with respect to the previous object region, and confident searching directions are determined by evaluating candidates of correspondences on their region levels; thus, the correspondences are searched among likely candidates in only the confident directions instead of searching through all candidates. To ensure the confident searching direction, we also adopt the region appearance, which is efficiently modeled on a newly defined local space (called a searching bundle). Experimental results and performance evaluations demonstrate that our method fully supports fast and robust textureless 3D object tracking even in highly cluttered backgrounds.

  20. Optimal local searching for fast and robust textureless 3D object tracking in highly cluttered backgrounds.

    PubMed

    Seo, Byung-Kuk; Park, Hanhoon; Park, Jong-Il; Hinterstoisser, Stefan; Ilic, Slobodan

    2014-01-01

    Edge-based tracking is a fast and plausible approach for textureless 3D object tracking, but its robustness is still very challenging in highly cluttered backgrounds due to numerous local minima. To overcome this problem, we propose a novel method for fast and robust textureless 3D object tracking in highly cluttered backgrounds. The proposed method is based on optimal local searching of 3D-2D correspondences between a known 3D object model and 2D scene edges in an image with heavy background clutter. In our searching scheme, searching regions are partitioned into three levels (interior, contour, and exterior) with respect to the previous object region, and confident searching directions are determined by evaluating candidates of correspondences on their region levels; thus, the correspondences are searched among likely candidates in only the confident directions instead of searching through all candidates. To ensure the confident searching direction, we also adopt the region appearance, which is efficiently modeled on a newly defined local space (called a searching bundle). Experimental results and performance evaluations demonstrate that our method fully supports fast and robust textureless 3D object tracking even in highly cluttered backgrounds.

  1. Research on target tracking based on improved SURF algorithm and Kalman prediction

    NASA Astrophysics Data System (ADS)

    Hu, Dandan; Nan, Jiang

    2016-07-01

    For the problem of ignoring color information and computing complexity and so on, a new target tracking algorithm based on improved SURF(Speed Up Robust Features) algorithm and Kalman filter fusion is studied. First, the color invariants are added in the generation process of SURF. And then the current position is predicted by using the Kalman filter and establishing the search window. Finally, the feature vectors in the search window are extracted by using the improved SURF algorithm for matching. The experiments prove that the algorithm can always track targets stably when the target appears scale changed, rotation and partial occlusion, and the tracking speed is greatly improved than that of the SURF algorithm.

  2. Visual Tracking Based on an Improved Online Multiple Instance Learning Algorithm.

    PubMed

    Wang, Li Jia; Zhang, Hua

    2016-01-01

    An improved online multiple instance learning (IMIL) for a visual tracking algorithm is proposed. In the IMIL algorithm, the importance of each instance contributing to a bag probability is with respect to their probabilities. A selection strategy based on an inner product is presented to choose weak classifier from a classifier pool, which avoids computing instance probabilities and bag probability M times. Furthermore, a feedback strategy is presented to update weak classifiers. In the feedback update strategy, different weights are assigned to the tracking result and template according to the maximum classifier score. Finally, the presented algorithm is compared with other state-of-the-art algorithms. The experimental results demonstrate that the proposed tracking algorithm runs in real-time and is robust to occlusion and appearance changes.

  3. Fast TPC Online Tracking on GPUs and Asynchronous Data Processing in the ALICE HLT to facilitate Online Calibration

    NASA Astrophysics Data System (ADS)

    Rohr, David; Gorbunov, Sergey; Krzewicki, Mikolaj; Breitner, Timo; Kretz, Matthias; Lindenstruth, Volker

    2015-12-01

    ALICE (A Large Heavy Ion Experiment) is one of the four major experiments at the Large Hadron Collider (LHC) at CERN, which is today the most powerful particle accelerator worldwide. The High Level Trigger (HLT) is an online compute farm of about 200 nodes, which reconstructs events measured by the ALICE detector in real-time. The HLT uses a custom online data-transport framework to distribute data and workload among the compute nodes. ALICE employs several calibration-sensitive subdetectors, e.g. the TPC (Time Projection Chamber). For a precise reconstruction, the HLT has to perform the calibration online. Online- calibration can make certain Offline calibration steps obsolete and can thus speed up Offline analysis. Looking forward to ALICE Run III starting in 2020, online calibration becomes a necessity. The main detector used for track reconstruction is the TPC. Reconstructing the trajectories in the TPC is the most compute-intense step during event reconstruction. Therefore, a fast tracking implementation is of great importance. Reconstructed TPC tracks build the basis for the calibration making a fast online-tracking mandatory. We present several components developed for the ALICE High Level Trigger to perform fast event reconstruction and to provide features required for online calibration. As first topic, we present our TPC tracker, which employs GPUs to speed up the processing, and which bases on a Cellular Automaton and on the Kalman filter. Our TPC tracking algorithm has been successfully used in 2011 and 2012 in the lead-lead and the proton-lead runs. We have improved it to leverage features of newer GPUs and we have ported it to support OpenCL, CUDA, and CPUs with a single common source code. This makes us vendor independent. As second topic, we present framework extensions required for online calibration. The extensions, however, are generic and can be used for other purposes as well. We have extended the framework to support asynchronous compute

  4. Active structured learning for cell tracking: algorithm, framework, and usability.

    PubMed

    Lou, Xinghua; Schiegg, Martin; Hamprecht, Fred A

    2014-04-01

    One distinguishing property of life is its temporal dynamics, and it is hence only natural that time lapse experiments play a crucial role in modern biomedical research areas such as signaling pathways, drug discovery or developmental biology. Such experiments yield a very large number of images that encode complex cellular activities, and reliable automated cell tracking emerges naturally as a prerequisite for further quantitative analysis. However, many existing cell tracking methods are restricted to using only a small number of features to allow for manual tweaking. In this paper, we propose a novel cell tracking approach that embraces a powerful machine learning technique to optimize the tracking parameters based on user annotated tracks. Our approach replaces the tedious parameter tuning with parameter learning and allows for the use of a much richer set of complex tracking features, which in turn affords superior prediction accuracy. Furthermore, we developed an active learning approach for efficient training data retrieval, which reduces the annotation effort to only 17%. In practical terms, our approach allows life science researchers to inject their expertise in a more intuitive and direct manner. This process is further facilitated by using a glyph visualization technique for ground truth annotation and validation. Evaluation and comparison on several publicly available benchmark sequences show significant performance improvement over recently reported approaches. Code and software tools are provided to the public.

  5. A fast and memory-sparing probabilistic selection algorithm for the GPU

    SciTech Connect

    Monroe, Laura M; Wendelberger, Joanne; Michalak, Sarah

    2010-09-29

    A fast and memory-sparing probabilistic top-N selection algorithm is implemented on the GPU. This probabilistic algorithm gives a deterministic result and always terminates. The use of randomization reduces the amount of data that needs heavy processing, and so reduces both the memory requirements and the average time required for the algorithm. This algorithm is well-suited to more general parallel processors with multiple layers of memory hierarchy. Probabilistic Las Vegas algorithms of this kind are a form of stochastic optimization and can be especially useful for processors having a limited amount of fast memory available.

  6. A fast look-up algorithm for detecting repetitive DNA sequences

    SciTech Connect

    Guan, X.; Uberbacher, E.C.

    1996-12-31

    We have presented a fast linear time algorithm for recognizing tandem repeats. Our algorithm is a one pass algorithm. No information about the periodicity of tandem repeats is needed. The use of the indices calculated from non-continuous and overlapping {kappa}-tuples allow tandem repeats with insertions and deletions to be recognized.

  7. TrackNTrace: A simple and extendable open-source framework for developing single-molecule localization and tracking algorithms.

    PubMed

    Stein, Simon Christoph; Thiart, Jan

    2016-11-25

    Super-resolution localization microscopy and single particle tracking are important tools for fluorescence microscopy. Both rely on detecting, and tracking, a large number of fluorescent markers using increasingly sophisticated computer algorithms. However, this rise in complexity makes it difficult to fine-tune parameters and detect inconsistencies, improve existing routines, or develop new approaches founded on established principles. We present an open-source MATLAB framework for single molecule localization, tracking and super-resolution applications. The purpose of this software is to facilitate the development, distribution, and comparison of methods in the community by providing a unique, easily extendable plugin-based system and combining it with a novel visualization system. This graphical interface incorporates possibilities for quick inspection of localization and tracking results, giving direct feedback of the quality achieved with the chosen algorithms and parameter values, as well as possible sources for errors. This is of great importance in practical applications and even more so when developing new techniques. The plugin system greatly simplifies the development of new methods as well as adapting and tailoring routines towards any research problem's individual requirements. We demonstrate its high speed and accuracy with plugins implementing state-of-the-art algorithms and show two biological applications.

  8. TrackNTrace: A simple and extendable open-source framework for developing single-molecule localization and tracking algorithms

    PubMed Central

    Stein, Simon Christoph; Thiart, Jan

    2016-01-01

    Super-resolution localization microscopy and single particle tracking are important tools for fluorescence microscopy. Both rely on detecting, and tracking, a large number of fluorescent markers using increasingly sophisticated computer algorithms. However, this rise in complexity makes it difficult to fine-tune parameters and detect inconsistencies, improve existing routines, or develop new approaches founded on established principles. We present an open-source MATLAB framework for single molecule localization, tracking and super-resolution applications. The purpose of this software is to facilitate the development, distribution, and comparison of methods in the community by providing a unique, easily extendable plugin-based system and combining it with a novel visualization system. This graphical interface incorporates possibilities for quick inspection of localization and tracking results, giving direct feedback of the quality achieved with the chosen algorithms and parameter values, as well as possible sources for errors. This is of great importance in practical applications and even more so when developing new techniques. The plugin system greatly simplifies the development of new methods as well as adapting and tailoring routines towards any research problem’s individual requirements. We demonstrate its high speed and accuracy with plugins implementing state-of-the-art algorithms and show two biological applications. PMID:27885259

  9. Lightning Jump Algorithm and Relation to Thunderstorm Cell Tracking, GLM Proxy and other Meteorological Measurements

    NASA Technical Reports Server (NTRS)

    Schultz, Christopher J.; Carey, Larry; Cecil, Dan; Bateman, Monte; Stano, Geoffrey; Goodman, Steve

    2012-01-01

    Objective of project is to refine, adapt and demonstrate the Lightning Jump Algorithm (LJA) for transition to GOES -R GLM (Geostationary Lightning Mapper) readiness and to establish a path to operations Ongoing work . reducing risk in GLM lightning proxy, cell tracking, LJA algorithm automation, and data fusion (e.g., radar + lightning).

  10. FAST-PT: a novel algorithm to calculate convolution integrals in cosmological perturbation theory

    NASA Astrophysics Data System (ADS)

    McEwen, Joseph E.; Fang, Xiao; Hirata, Christopher M.; Blazek, Jonathan A.

    2016-09-01

    We present a novel algorithm, FAST-PT, for performing convolution or mode-coupling integrals that appear in nonlinear cosmological perturbation theory. The algorithm uses several properties of gravitational structure formation—the locality of the dark matter equations and the scale invariance of the problem—as well as Fast Fourier Transforms to describe the input power spectrum as a superposition of power laws. This yields extremely fast performance, enabling mode-coupling integral computations fast enough to embed in Monte Carlo Markov Chain parameter estimation. We describe the algorithm and demonstrate its application to calculating nonlinear corrections to the matter power spectrum, including one-loop standard perturbation theory and the renormalization group approach. We also describe our public code (in Python) to implement this algorithm. The code, along with a user manual and example implementations, is available at https://github.com/JoeMcEwen/FAST-PT.

  11. Preventing Serious Conduct Problems in School-Age Youths: The Fast Track Program

    PubMed Central

    Slough, Nancy M.; McMahon, Robert J.; Bierman, Karen L.; Coie, John D.; Dodge, Kenneth A.; Foster, E. Michael; Greenberg, Mark T.; Lochman, John E.; McMahon, Robert J.; Pinderhughes, Ellen E.

    2009-01-01

    Children with early-starting conduct Problems have a very poor prognosis and exact a high cost to society. The Fast Track project is a multisite, collaborative research project investigating the efficacy of a comprehensive, long-term, multicomponent intervention designed to prevent the development of serious conduct problems in high-risk children. In this article, we (a) provide an overview of the development model that serves as the conceptual foundation for the Fast Track intervention and describe its integration into the intervention model; (b) outline the research design and intervention model, with an emphasis on the elementary school phase of the intervention; and (c) summarize findings to dale concerning intervention outcomes. We then provide a case illustration, and conclude with a discussion of guidelines for practitioners who work with children with conduct problems. PMID:19890487

  12. Developmental Mediation of Genetic Variation in Response to the Fast Track Prevention Program

    PubMed Central

    Albert, Dustin; Belsky, Daniel W.; Crowley, D. Max; Bates, John E.; Pettit, Gregory S.; Lansford, Jennifer E.; Dick, Danielle; Dodge, Kenneth A.

    2015-01-01

    We conducted a developmental analysis of genetic moderation of the effect of the Fast Track intervention on adult externalizing psychopathology. The Fast Track intervention enrolled 891 children at high risk to develop externalizing behavior problems when they were in kindergarten. Half of the enrolled children were randomly assigned to receive 10 years of treatment with a range of services and resources provided to the children and their families and the other half to usual care (controls). We previously showed that the effect of the Fast Track intervention on participants’ risk of externalizing psychopathology at age 25 years was moderated by a variant in the Glucocorticoid Receptor Gene (NR3C1). Children who carried copies of the A-allele of the single-nucleotide polymorphism rs10482672 had the highest risk of externalizing psychopathology if they were in the control arm of the trial and the lowest risk of externalizing psychopathology if they were in the treatment arm. In this study, we test a developmental hypothesis about the origins of this for-better-and-for-worse gene-by-intervention interaction (GxI): That the observed GxI effect on adult psychopathology is mediated by the proximal impact of intervention on childhood externalizing problems and adolescent substance use and delinquency. We analyzed longitudinal data tracking the 270 European-American children in the Fast Track RCT with available genetic information (129 intervention children and 141 control-group peers, 69% male) from kindergarten through age 25 years. Results show that the same pattern of “for-better-and-for-worse” susceptibility to intervention observed at the age-25 follow-up was evident already during childhood. At the elementary school follow-ups and at the middle/high-school follow-ups, rs10482672 predicted better adjustment among children receiving the Fast Track intervention, and worse adjustment among children in the control condition. In turn, these proximal GxI effects

  13. Telemedicine support shortens length of stay after fast-track hip replacement.

    PubMed

    Vesterby, Martin Svoldgaard; Pedersen, Preben Ulrich; Laursen, Malene; Mikkelsen, Søren; Larsen, Jens; Søballe, Kjeld; Jørgensen, Lene Bastrup

    2017-02-01

    Background and purpose - Telemedicine could allow patients to be discharged more quickly after surgery and contribute to improve fast-track procedures without compromising quality, patient safety, functionality, anxiety, or other patient-perceived parameters. We investigated whether using telemedicine support (TMS) would permit hospital discharge after 1 day without loss of self-assessed quality of life, loss of functionality, increased anxiety, increased rates of re-admission, or increased rates of complications after hip replacement. Patients and methods - We performed a randomized controlled trial involving 72 Danish patients in 1 region who were referred for elective fast-track total hip replacement between August 2009 and March 2011 (654 were screened for eligibility). Half of the patients received a telemedicine solution connected to their TV. The patients were followed until 1 year after surgery. Results - Length of stay was reduced from 2.1 days (95% CI: 2.0-2.3) to 1.1 day (CI: 0.9-1.4; p < 0.001) with the TMS intervention. Health-related quality of life increased in both groups, but there were no statistically significant differences between groups. There were also no statistically significant differences between groups regarding timed up-and-go test and Oxford hip score at 3-month follow-up. At 12-month follow-up, the rates of complications and re-admissions were similar between the groups, but the number of postoperative hospital contacts was lower in the TMS group. Interpretation - Length of postoperative stay was shortened in patients with the TMS solution, without compromising patient-perceived or clinical parameters in patients undergoing elective fast-track surgery. These results indicate that telemedicine can be of value in fast-track treatment of patients undergoing total hip replacement.

  14. Transformed Governance and the Education for All-Fast Track Initiative. Policy Brief 2010-02

    ERIC Educational Resources Information Center

    Gartner, David

    2010-01-01

    The Education for All-Fast Track Initiative (FTI) grew out of the "New Focus on Education for All" communique of the G-8 when Canada hosted the summit in 2002 at Kananaskis. As Canada prepares again to host the G-8, and Korea assumes leadership of the newly-empowered G-20, it is a valuable moment to revisit and re-think the current…

  15. Fast left ventricle tracking in CMR images using localized anatomical affine optical flow

    NASA Astrophysics Data System (ADS)

    Queirós, Sandro; Vilaça, João. L.; Morais, Pedro; Fonseca, Jaime C.; D'hooge, Jan; Barbosa, Daniel

    2015-03-01

    In daily cardiology practice, assessment of left ventricular (LV) global function using non-invasive imaging remains central for the diagnosis and follow-up of patients with cardiovascular diseases. Despite the different methodologies currently accessible for LV segmentation in cardiac magnetic resonance (CMR) images, a fast and complete LV delineation is still limitedly available for routine use. In this study, a localized anatomically constrained affine optical flow method is proposed for fast and automatic LV tracking throughout the full cardiac cycle in short-axis CMR images. Starting from an automatically delineated LV in the end-diastolic frame, the endocardial and epicardial boundaries are propagated by estimating the motion between adjacent cardiac phases using optical flow. In order to reduce the computational burden, the motion is only estimated in an anatomical region of interest around the tracked boundaries and subsequently integrated into a local affine motion model. Such localized estimation enables to capture complex motion patterns, while still being spatially consistent. The method was validated on 45 CMR datasets taken from the 2009 MICCAI LV segmentation challenge. The proposed approach proved to be robust and efficient, with an average distance error of 2.1 mm and a correlation with reference ejection fraction of 0.98 (1.9 +/- 4.5%). Moreover, it showed to be fast, taking 5 seconds for the tracking of a full 4D dataset (30 ms per image). Overall, a novel fast, robust and accurate LV tracking methodology was proposed, enabling accurate assessment of relevant global function cardiac indices, such as volumes and ejection fraction

  16. FAST: A fully asynchronous and status-tracking pattern for geoprocessing services orchestration

    NASA Astrophysics Data System (ADS)

    Wu, Huayi; You, Lan; Gui, Zhipeng; Gao, Shuang; Li, Zhenqiang; Yu, Jingmin

    2014-09-01

    Geoprocessing service orchestration (GSO) provides a unified and flexible way to implement cross-application, long-lived, and multi-step geoprocessing service workflows by coordinating geoprocessing services collaboratively. Usually, geoprocessing services and geoprocessing service workflows are data and/or computing intensive. The intensity feature may make the execution process of a workflow time-consuming. Since it initials an execution request without blocking other interactions on the client side, an asynchronous mechanism is especially appropriate for GSO workflows. Many critical problems remain to be solved in existing asynchronous patterns for GSO including difficulties in improving performance, status tracking, and clarifying the workflow structure. These problems are a challenge when orchestrating performance efficiency, making statuses instantly available, and constructing clearly structured GSO workflows. A Fully Asynchronous and Status-Tracking (FAST) pattern that adopts asynchronous interactions throughout the whole communication tier of a workflow is proposed for GSO. The proposed FAST pattern includes a mechanism that actively pushes the latest status to clients instantly and economically. An independent proxy was designed to isolate the status tracking logic from the geoprocessing business logic, which assists the formation of a clear GSO workflow structure. A workflow was implemented in the FAST pattern to simulate the flooding process in the Poyang Lake region. Experimental results show that the proposed FAST pattern can efficiently tackle data/computing intensive geoprocessing tasks. The performance of all collaborative partners was improved due to the asynchronous mechanism throughout communication tier. A status-tracking mechanism helps users retrieve the latest running status of a GSO workflow in an efficient and instant way. The clear structure of the GSO workflow lowers the barriers for geospatial domain experts and model designers to

  17. Telemedicine support shortens length of stay after fast-track hip replacement

    PubMed Central

    Vesterby, Martin Svoldgaard; Pedersen, Preben Ulrich; Laursen, Malene; Mikkelsen, Søren; Larsen, Jens; Søballe, Kjeld; Jørgensen, Lene Bastrup

    2017-01-01

    Background and purpose — Telemedicine could allow patients to be discharged more quickly after surgery and contribute to improve fast-track procedures without compromising quality, patient safety, functionality, anxiety, or other patient-perceived parameters. We investigated whether using telemedicine support (TMS) would permit hospital discharge after 1 day without loss of self-assessed quality of life, loss of functionality, increased anxiety, increased rates of re-admission, or increased rates of complications after hip replacement. Patients and methods — We performed a randomized controlled trial involving 72 Danish patients in 1 region who were referred for elective fast-track total hip replacement between August 2009 and March 2011 (654 were screened for eligibility). Half of the patients received a telemedicine solution connected to their TV. The patients were followed until 1 year after surgery. Results — Length of stay was reduced from 2.1 days (95% CI: 2.0–2.3) to 1.1 day (CI: 0.9–1.4; p < 0.001) with the TMS intervention. Health-related quality of life increased in both groups, but there were no statistically significant differences between groups. There were also no statistically significant differences between groups regarding timed up-and-go test and Oxford hip score at 3-month follow-up. At 12-month follow-up, the rates of complications and re-admissions were similar between the groups, but the number of postoperative hospital contacts was lower in the TMS group. Interpretation — Length of postoperative stay was shortened in patients with the TMS solution, without compromising patient-perceived or clinical parameters in patients undergoing elective fast-track surgery. These results indicate that telemedicine can be of value in fast-track treatment of patients undergoing total hip replacement. PMID:28097941

  18. Error analysis of the de-crosstalk algorithm for the multianode-PMT-based quadrant tracking sensor.

    PubMed

    Ma, Xiaoyu; Rao, Changhui; Wei, Kai; Guo, Youming; Rao, Xuejun

    2012-12-31

    For the multianode-PMT-based quadrant tracking sensor, one of the tracking error sources is the crosstalk. The crosstalk can be reduced by de-crosstalk algorithm, so the tracking error of the de-crosstalk algorithm for the multianode-PMT-based quadrant tracking sensor are analyzed in theory and verified by experiments. Both the theoretical analysis and the experimental results showed that the spot displacement sensitivity could be improved by the de-crosstalk algorithm, but the spot centroid detecting error increased at the same time. So the de-crosstalk algorithm could not improve the tracking accuracy effectively.

  19. Nonuniform fast Fourier transform-based fast back-projection algorithm for stepped frequency continuous wave ground penetrating radar imaging

    NASA Astrophysics Data System (ADS)

    Qu, Lele; Yin, Yuqing

    2016-10-01

    Stepped frequency continuous wave ground penetrating radar (SFCW-GPR) systems are becoming increasingly popular in the GPR community due to the wider dynamic range and higher immunity to radio interference. The traditional back-projection (BP) algorithm is preferable for SFCW-GPR imaging in layered mediums scenarios for its convenience and robustness. However, the existing BP imaging algorithms are usually very computationally intensive, which limits their practical applications to SFCW-GPR imaging. To solve the above problem, a fast SFCW-GPR BP imaging algorithm based on nonuniform fast Fourier transform (NUFFT) technique is proposed in this paper. By reformulating the traditional BP imaging algorithm into the evaluations of NUFFT, the computational efficiency of NUFFT is exploited to reduce the computational complexity of the imaging reconstruction. Both simulation and experimental results have verified the effectiveness and improvement of computational efficiency of the proposed imaging method.

  20. Fast inverse scattering solutions using the distorted Born iterative method and the multilevel fast multipole algorithm

    PubMed Central

    Hesford, Andrew J.; Chew, Weng C.

    2010-01-01

    The distorted Born iterative method (DBIM) computes iterative solutions to nonlinear inverse scattering problems through successive linear approximations. By decomposing the scattered field into a superposition of scattering by an inhomogeneous background and by a material perturbation, large or high-contrast variations in medium properties can be imaged through iterations that are each subject to the distorted Born approximation. However, the need to repeatedly compute forward solutions still imposes a very heavy computational burden. To ameliorate this problem, the multilevel fast multipole algorithm (MLFMA) has been applied as a forward solver within the DBIM. The MLFMA computes forward solutions in linear time for volumetric scatterers. The typically regular distribution and shape of scattering elements in the inverse scattering problem allow the method to take advantage of data redundancy and reduce the computational demands of the normally expensive MLFMA setup. Additional benefits are gained by employing Kaczmarz-like iterations, where partial measurements are used to accelerate convergence. Numerical results demonstrate both the efficiency of the forward solver and the successful application of the inverse method to imaging problems with dimensions in the neighborhood of ten wavelengths. PMID:20707438

  1. Fast inverse scattering solutions using the distorted Born iterative method and the multilevel fast multipole algorithm.

    PubMed

    Hesford, Andrew J; Chew, Weng C

    2010-08-01

    The distorted Born iterative method (DBIM) computes iterative solutions to nonlinear inverse scattering problems through successive linear approximations. By decomposing the scattered field into a superposition of scattering by an inhomogeneous background and by a material perturbation, large or high-contrast variations in medium properties can be imaged through iterations that are each subject to the distorted Born approximation. However, the need to repeatedly compute forward solutions still imposes a very heavy computational burden. To ameliorate this problem, the multilevel fast multipole algorithm (MLFMA) has been applied as a forward solver within the DBIM. The MLFMA computes forward solutions in linear time for volumetric scatterers. The typically regular distribution and shape of scattering elements in the inverse scattering problem allow the method to take advantage of data redundancy and reduce the computational demands of the normally expensive MLFMA setup. Additional benefits are gained by employing Kaczmarz-like iterations, where partial measurements are used to accelerate convergence. Numerical results demonstrate both the efficiency of the forward solver and the successful application of the inverse method to imaging problems with dimensions in the neighborhood of ten wavelengths.

  2. Fixed Interval Smoothing Algorithm for an Extended Kalman Filter for Over-the-Horizon Ship Tracking

    DTIC Science & Technology

    1989-03-01

    accurate than an estimate based only on the estimates up to time k, (.k,). Meditch [Ref. 10: p. 193] categorizes smoothing algorithms into three...NAVAL POSTGRADUATE SCHOOL Monterey, California DTIC ELECTE A JUN0 89 * TEESIS In * FIXED INTERVAL SMOOTHING ALGORITHM FOR A\\ EXTENDED KALMAN 0 FILTER...track a maneuvering surface target using HFDF lines-of-bearing is sub -tantially improved by implementing a fixed interval smoothing algorithm and a

  3. Fuzzy Neural Network-Based Interacting Multiple Model for Multi-Node Target Tracking Algorithm

    PubMed Central

    Sun, Baoliang; Jiang, Chunlan; Li, Ming

    2016-01-01

    An interacting multiple model for multi-node target tracking algorithm was proposed based on a fuzzy neural network (FNN) to solve the multi-node target tracking problem of wireless sensor networks (WSNs). Measured error variance was adaptively adjusted during the multiple model interacting output stage using the difference between the theoretical and estimated values of the measured error covariance matrix. The FNN fusion system was established during multi-node fusion to integrate with the target state estimated data from different nodes and consequently obtain network target state estimation. The feasibility of the algorithm was verified based on a network of nine detection nodes. Experimental results indicated that the proposed algorithm could trace the maneuvering target effectively under sensor failure and unknown system measurement errors. The proposed algorithm exhibited great practicability in the multi-node target tracking of WSNs. PMID:27809271

  4. Online Tracking Algorithms on GPUs for the P̅ANDA Experiment at FAIR

    NASA Astrophysics Data System (ADS)

    Bianchi, L.; Herten, A.; Ritman, J.; Stockmanns, T.; Adinetz, A.; Kraus, J.; Pleiter, D.

    2015-12-01

    P̅ANDA is a future hadron and nuclear physics experiment at the FAIR facility in construction in Darmstadt, Germany. In contrast to the majority of current experiments, PANDA's strategy for data acquisition is based on event reconstruction from free-streaming data, performed in real time entirely by software algorithms using global detector information. This paper reports the status of the development of algorithms for the reconstruction of charged particle tracks, optimized online data processing applications, using General-Purpose Graphic Processing Units (GPU). Two algorithms for trackfinding, the Triplet Finder and the Circle Hough, are described, and details of their GPU implementations are highlighted. Average track reconstruction times of less than 100 ns are obtained running the Triplet Finder on state-of- the-art GPU cards. In addition, a proof-of-concept system for the dispatch of data to tracking algorithms using Message Queues is presented.

  5. An efficient Lagrangean relaxation-based object tracking algorithm in wireless sensor networks.

    PubMed

    Lin, Frank Yeong-Sung; Lee, Cheng-Ta

    2010-01-01

    In this paper we propose an energy-efficient object tracking algorithm in wireless sensor networks (WSNs). Such sensor networks have to be designed to achieve energy-efficient object tracking for any given arbitrary topology. We consider in particular the bi-directional moving objects with given frequencies for each pair of sensor nodes and link transmission cost. This problem is formulated as a 0/1 integer-programming problem. A Lagrangean relaxation-based (LR-based) heuristic algorithm is proposed for solving the optimization problem. Experimental results showed that the proposed algorithm achieves near optimization in energy-efficient object tracking. Furthermore, the algorithm is very efficient and scalable in terms of the solution time.

  6. Space debris tracking based on fuzzy running Gaussian average adaptive particle filter track-before-detect algorithm

    NASA Astrophysics Data System (ADS)

    Torteeka, Peerapong; Gao, Peng-Qi; Shen, Ming; Guo, Xiao-Zhang; Yang, Da-Tao; Yu, Huan-Huan; Zhou, Wei-Ping; Zhao, You

    2017-02-01

    Although tracking with a passive optical telescope is a powerful technique for space debris observation, it is limited by its sensitivity to dynamic background noise. Traditionally, in the field of astronomy, static background subtraction based on a median image technique has been used to extract moving space objects prior to the tracking operation, as this is computationally efficient. The main disadvantage of this technique is that it is not robust to variable illumination conditions. In this article, we propose an approach for tracking small and dim space debris in the context of a dynamic background via one of the optical telescopes that is part of the space surveillance network project, named the Asia-Pacific ground-based Optical Space Observation System or APOSOS. The approach combines a fuzzy running Gaussian average for robust moving-object extraction with dim-target tracking using a particle-filter-based track-before-detect method. The performance of the proposed algorithm is experimentally evaluated, and the results show that the scheme achieves a satisfactory level of accuracy for space debris tracking.

  7. Fast Fourier transform for Voigt profile: Comparison with some other algorithms

    NASA Astrophysics Data System (ADS)

    Abousahl, S.; Gourma, M.; Bickel, M.

    1997-02-01

    There are different algorithms describing the Voigt profile. This profile is encountered in many areas of physics which could be limited by the resolution of the instrumentation used to measure it and by other phenomena like the interaction between the emitted waves and matter. In nuclear measurement field, the codes used to characterise radionucleides rely on algorithms resolving the Voigt profile equation. The Fast Fourier Transform (FFT) algorithm allows the validation of some algorithms.

  8. The research on algorithms for optoelectronic tracking servo control systems

    NASA Astrophysics Data System (ADS)

    Zhu, Qi-Hai; Zhao, Chang-Ming; Zhu, Zheng; Li, Kun

    2016-10-01

    The photoelectric servo control system based on PC controllers is mainly used to control the speed and position of the load. This paper analyzed the mathematical modeling and the system identification of the servo system. In the aspect of the control algorithm, the IP regulator, the fuzzy PID, the Active Disturbance Rejection Control (ADRC) and the adaptive algorithms were compared and analyzed. The PI-P control algorithm was proposed in this paper, which not only has the advantages of the PI regulator that can be quickly saturated, but also overcomes the shortcomings of the IP regulator. The control system has a good starting performance and the anti-load ability in a wide range. Experimental results show that the system has good performance under the guarantee of the PI-P control algorithm.

  9. International collaborative project to compare and track the nutritional composition of fast foods

    PubMed Central

    2012-01-01

    Background Chronic diseases are the leading cause of premature death and disability in the world with over-nutrition a primary cause of diet-related ill health. Excess quantities of energy, saturated fat, sugar and salt derived from fast foods contribute importantly to this disease burden. Our objective is to collate and compare nutrient composition data for fast foods as a means of supporting improvements in product formulation. Methods/design Surveys of fast foods will be done in each participating country each year. Information on the nutrient composition for each product will be sought either through direct chemical analysis, from fast food companies, in-store materials or from company websites. Foods will be categorized into major groups for the primary analyses which will compare mean levels of saturated fat, sugar, sodium, energy and serving size at baseline and over time. Countries currently involved include Australia, New Zealand, France, UK, USA, India, Spain, China and Canada, with more anticipated to follow. Discussion This collaborative approach to the collation and sharing of data will enable low-cost tracking of fast food composition around the world. This project represents a significant step forward in the objective and transparent monitoring of industry and government commitments to improve the quality of fast foods. PMID:22838731

  10. A video demonstration of the Li's anastomosis-the key part of the "non-tube no fasting" fast track program for resectable esophageal carcinoma.

    PubMed

    Zheng, Yan; Li, Yin; Wang, Zongfei; Sun, Haibo; Zhang, Ruixiang

    2015-07-01

    The main obstacle of fast track surgery for esophagectomy is early oral feeding. The main concern of early oral feeding is the possibility of increasing the incidence of anastomotic leakage. Dr. Yin Li used the Li's anastomosis to ensure oral feeding at will the first day after esophagectomy. This safe and efficient anastomosis method significantly reduced the anastomotic leak rate, the number of post-operative days and stricture. Importantly, the "non-tube no fasting" fast track program for esophageal cancer patients was conducted smoothly with Li's anastomosis. This article was focused on the surgical procedure of Li's anastomosis.

  11. [A fast non-local means algorithm for denoising of computed tomography images].

    PubMed

    Kang, Changqing; Cao, Wenping; Fang, Lei; Hua, Li; Cheng, Hong

    2012-11-01

    A fast non-local means image denoising algorithm is presented based on the single motif of existing computed tomography images in medical archiving systems. The algorithm is carried out in two steps of prepossessing and actual possessing. The sample neighborhood database is created via the data structure of locality sensitive hashing in the prepossessing stage. The CT image noise is removed by non-local means algorithm based on the sample neighborhoods accessed fast by locality sensitive hashing. The experimental results showed that the proposed algorithm could greatly reduce the execution time, as compared to NLM, and effectively preserved the image edges and details.

  12. A fast algorithm for functional mapping of complex traits.

    PubMed Central

    Zhao, Wei; Wu, Rongling; Ma, Chang-Xing; Casella, George

    2004-01-01

    By integrating the underlying developmental mechanisms for the phenotypic formation of traits into a mapping framework, functional mapping has emerged as an important statistical approach for mapping complex traits. In this note, we explore the feasibility of using the simplex algorithm as an alternative to solve the mixture-based likelihood for functional mapping of complex traits. The results from the simplex algorithm are consistent with those from the traditional EM algorithm, but the simplex algorithm has considerably reduced computational times. Moreover, because of its nonderivative nature and easy implementation with current software, the simplex algorithm enjoys an advantage over the EM algorithm in the dynamic modeling and analysis of complex traits. PMID:15342547

  13. Interacting with target tracking algorithms in a gaze-enhanced motion video analysis system

    NASA Astrophysics Data System (ADS)

    Hild, Jutta; Krüger, Wolfgang; Heinze, Norbert; Peinsipp-Byma, Elisabeth; Beyerer, Jürgen

    2016-05-01

    Motion video analysis is a challenging task, particularly if real-time analysis is required. It is therefore an important issue how to provide suitable assistance for the human operator. Given that the use of customized video analysis systems is more and more established, one supporting measure is to provide system functions which perform subtasks of the analysis. Recent progress in the development of automated image exploitation algorithms allow, e.g., real-time moving target tracking. Another supporting measure is to provide a user interface which strives to reduce the perceptual, cognitive and motor load of the human operator for example by incorporating the operator's visual focus of attention. A gaze-enhanced user interface is able to help here. This work extends prior work on automated target recognition, segmentation, and tracking algorithms as well as about the benefits of a gaze-enhanced user interface for interaction with moving targets. We also propose a prototypical system design aiming to combine both the qualities of the human observer's perception and the automated algorithms in order to improve the overall performance of a real-time video analysis system. In this contribution, we address two novel issues analyzing gaze-based interaction with target tracking algorithms. The first issue extends the gaze-based triggering of a target tracking process, e.g., investigating how to best relaunch in the case of track loss. The second issue addresses the initialization of tracking algorithms without motion segmentation where the operator has to provide the system with the object's image region in order to start the tracking algorithm.

  14. Vision-based measurement for rotational speed by improving Lucas-Kanade template tracking algorithm.

    PubMed

    Guo, Jie; Zhu, Chang'an; Lu, Siliang; Zhang, Dashan; Zhang, Chunyu

    2016-09-01

    Rotational angle and speed are important parameters for condition monitoring and fault diagnosis of rotating machineries, and their measurement is useful in precision machining and early warning of faults. In this study, a novel vision-based measurement algorithm is proposed to complete this task. A high-speed camera is first used to capture the video of the rotational object. To extract the rotational angle, the template-based Lucas-Kanade algorithm is introduced to complete motion tracking by aligning the template image in the video sequence. Given the special case of nonplanar surface of the cylinder object, a nonlinear transformation is designed for modeling the rotation tracking. In spite of the unconventional and complex form, the transformation can realize angle extraction concisely with only one parameter. A simulation is then conducted to verify the tracking effect, and a practical tracking strategy is further proposed to track consecutively the video sequence. Based on the proposed algorithm, instantaneous rotational speed (IRS) can be measured accurately and efficiently. Finally, the effectiveness of the proposed algorithm is verified on a brushless direct current motor test rig through the comparison with results obtained by the microphone. Experimental results demonstrate that the proposed algorithm can extract accurately rotational angles and can measure IRS with the advantage of noncontact and effectiveness.

  15. Fast multiresolution search algorithm for optimal retrieval in large multimedia databases

    NASA Astrophysics Data System (ADS)

    Song, Byung C.; Kim, Myung J.; Ra, Jong Beom

    1999-12-01

    Most of the content-based image retrieval systems require a distance computation for each candidate image in the database. As a brute-force approach, the exhaustive search can be employed for this computation. However, this exhaustive search is time-consuming and limits the usefulness of such systems. Thus, there is a growing demand for a fast algorithm which provides the same retrieval results as the exhaustive search. In this paper, we prose a fast search algorithm based on a multi-resolution data structure. The proposed algorithm computes the lower bound of distance at each level and compares it with the latest minimum distance, starting from the low-resolution level. Once it is larger than the latest minimum distance, we can exclude the candidates without calculating the full- resolution distance. By doing this, we can dramatically reduce the total computational complexity. It is noticeable that the proposed fast algorithm provides not only the same retrieval results as the exhaustive search, but also a faster searching ability than existing fast algorithms. For additional performance improvement, we can easily combine the proposed algorithm with existing tree-based algorithms. The algorithm can also be used for the fast matching of various features such as luminance histograms, edge images, and local binary partition textures.

  16. Lightning Jump Algorithm and Relation to Thunderstorm Cell Tracking, GLM Proxy and Other Meteorological Measurements

    NASA Technical Reports Server (NTRS)

    Schultz, Christopher J.; Carey, Lawrence D.; Cecil, Daniel J.; Bateman, Monte

    2012-01-01

    The lightning jump algorithm has a robust history in correlating upward trends in lightning to severe and hazardous weather occurrence. The algorithm uses the correlation between the physical principles that govern an updraft's ability to produce microphysical and kinematic conditions conducive for electrification and its role in the development of severe weather conditions. Recent work has demonstrated that the lightning jump algorithm concept holds significant promise in the operational realm, aiding in the identification of thunderstorms that have potential to produce severe or hazardous weather. However, a large amount of work still needs to be completed in spite of these positive results. The total lightning jump algorithm is not a stand-alone concept that can be used independent of other meteorological measurements, parameters, and techniques. For example, the algorithm is highly dependent upon thunderstorm tracking to build lightning histories on convective cells. Current tracking methods show that thunderstorm cell tracking is most reliable and cell histories are most accurate when radar information is incorporated with lightning data. In the absence of radar data, the cell tracking is a bit less reliable but the value added by the lightning information is much greater. For optimal application, the algorithm should be integrated with other measurements that assess storm scale properties (e.g., satellite, radar). Therefore, the recent focus of this research effort has been assessing the lightning jump's relation to thunderstorm tracking, meteorological parameters, and its potential uses in operational meteorology. Furthermore, the algorithm must be tailored for the optically-based GOES-R Geostationary Lightning Mapper (GLM), as what has been observed using Very High Frequency Lightning Mapping Array (VHF LMA) measurements will not exactly translate to what will be observed by GLM due to resolution and other instrument differences. Herein, we present some of

  17. Fast leaf-fitting with generalized underdose/overdose constraints for real-time MLC tracking

    SciTech Connect

    Moore, Douglas Sawant, Amit; Ruan, Dan

    2016-01-15

    Purpose: Real-time multileaf collimator (MLC) tracking is a promising approach to the management of intrafractional tumor motion during thoracic and abdominal radiotherapy. MLC tracking is typically performed in two steps: transforming a planned MLC aperture in response to patient motion and refitting the leaves to the newly generated aperture. One of the challenges of this approach is the inability to faithfully reproduce the desired motion-adapted aperture. This work presents an optimization-based framework with which to solve this leaf-fitting problem in real-time. Methods: This optimization framework is designed to facilitate the determination of leaf positions in real-time while accounting for the trade-off between coverage of the PTV and avoidance of organs at risk (OARs). Derived within this framework, an algorithm is presented that can account for general linear transformations of the planned MLC aperture, particularly 3D translations and in-plane rotations. This algorithm, together with algorithms presented in Sawant et al. [“Management of three-dimensional intrafraction motion through real-time DMLC tracking,” Med. Phys. 35, 2050–2061 (2008)] and Ruan and Keall [Presented at the 2011 IEEE Power Engineering and Automation Conference (PEAM) (2011) (unpublished)], was applied to apertures derived from eight lung intensity modulated radiotherapy plans subjected to six-degree-of-freedom motion traces acquired from lung cancer patients using the kilovoltage intrafraction monitoring system developed at the University of Sydney. A quality-of-fit metric was defined, and each algorithm was evaluated in terms of quality-of-fit and computation time. Results: This algorithm is shown to perform leaf-fittings of apertures, each with 80 leaf pairs, in 0.226 ms on average as compared to 0.082 and 64.2 ms for the algorithms of Sawant et al., Ruan, and Keall, respectively. The algorithm shows approximately 12% improvement in quality-of-fit over the Sawant et al

  18. Data Association and Bullet Tracking Algorithms for the Fight Sight Experiment

    SciTech Connect

    Breitfeller, E; Roberts, R

    2005-10-07

    Previous LLNL investigators developed a bullet and projectile tracking system over a decade ago. Renewed interest in the technology has spawned research that culminated in a live-fire experiment, called Fight Sight, in September 2005. The experiment was more complex than previous LLNL bullet tracking experiments in that it included multiple shooters with simultaneous fire, new sensor-shooter geometries, large amounts of optical clutter, and greatly increased sensor-shooter distances. This presentation describes the data association and tracking algorithms for the Fight Sight experiment. Image processing applied to the imagery yields a sequence of bullet features which are input to a data association routine. The data association routine matches features with existing tracks, or initializes new tracks as needed. A Kalman filter is used to smooth and extrapolate existing tracks. The Kalman filter is also used to back-track bullets to their point of origin, thereby revealing the location of the shooter. It also provides an error ellipse for each shooter, quantifying the uncertainty of shooter location. In addition to describing the data association and tracking algorithms, several examples from the Fight Sight experiment are also presented.

  19. The new approach for infrared target tracking based on the particle filter algorithm

    NASA Astrophysics Data System (ADS)

    Sun, Hang; Han, Hong-xia

    2011-08-01

    Target tracking on the complex background in the infrared image sequence is hot research field. It provides the important basis in some fields such as video monitoring, precision, and video compression human-computer interaction. As a typical algorithms in the target tracking framework based on filtering and data connection, the particle filter with non-parameter estimation characteristic have ability to deal with nonlinear and non-Gaussian problems so it were widely used. There are various forms of density in the particle filter algorithm to make it valid when target occlusion occurred or recover tracking back from failure in track procedure, but in order to capture the change of the state space, it need a certain amount of particles to ensure samples is enough, and this number will increase in accompany with dimension and increase exponentially, this led to the increased amount of calculation is presented. In this paper particle filter algorithm and the Mean shift will be combined. Aiming at deficiencies of the classic mean shift Tracking algorithm easily trapped into local minima and Unable to get global optimal under the complex background. From these two perspectives that "adaptive multiple information fusion" and "with particle filter framework combining", we expand the classic Mean Shift tracking framework .Based on the previous perspective, we proposed an improved Mean Shift infrared target tracking algorithm based on multiple information fusion. In the analysis of the infrared characteristics of target basis, Algorithm firstly extracted target gray and edge character and Proposed to guide the above two characteristics by the moving of the target information thus we can get new sports guide grayscale characteristics and motion guide border feature. Then proposes a new adaptive fusion mechanism, used these two new information adaptive to integrate into the Mean Shift tracking framework. Finally we designed a kind of automatic target model updating strategy

  20. Improving GPU-accelerated adaptive IDW interpolation algorithm using fast kNN search.

    PubMed

    Mei, Gang; Xu, Nengxiong; Xu, Liangliang

    2016-01-01

    This paper presents an efficient parallel Adaptive Inverse Distance Weighting (AIDW) interpolation algorithm on modern Graphics Processing Unit (GPU). The presented algorithm is an improvement of our previous GPU-accelerated AIDW algorithm by adopting fast k-nearest neighbors (kNN) search. In AIDW, it needs to find several nearest neighboring data points for each interpolated point to adaptively determine the power parameter; and then the desired prediction value of the interpolated point is obtained by weighted interpolating using the power parameter. In this work, we develop a fast kNN search approach based on the space-partitioning data structure, even grid, to improve the previous GPU-accelerated AIDW algorithm. The improved algorithm is composed of the stages of kNN search and weighted interpolating. To evaluate the performance of the improved algorithm, we perform five groups of experimental tests. The experimental results indicate: (1) the improved algorithm can achieve a speedup of up to 1017 over the corresponding serial algorithm; (2) the improved algorithm is at least two times faster than our previous GPU-accelerated AIDW algorithm; and (3) the utilization of fast kNN search can significantly improve the computational efficiency of the entire GPU-accelerated AIDW algorithm.

  1. Fast Nonparametric Machine Learning Algorithms for High-Dimensional Massive Data and Applications

    DTIC Science & Technology

    2006-03-01

    Mapreduce : Simplified data processing on large clusters . In Symposium on Operating System Design and Implementation, 2004. 6.3.2 S. C. Deerwester, S. T...Fast Nonparametric Machine Learning Algorithms for High-dimensional Massive Data and Applications Ting Liu CMU-CS-06-124 March 2006 School of...4. TITLE AND SUBTITLE Fast Nonparametric Machine Learning Algorithms for High-dimensional Massive Data and Applications 5a. CONTRACT NUMBER 5b

  2. A fast quantum algorithm for the affine Boolean function identification

    NASA Astrophysics Data System (ADS)

    Younes, Ahmed

    2015-02-01

    Bernstein-Vazirani algorithm (the one-query algorithm) can identify a completely specified linear Boolean function using a single query to the oracle with certainty. The first aim of the paper is to show that if the provided Boolean function is affine, then one more query to the oracle (the two-query algorithm) is required to identify the affinity of the function with certainty. The second aim of the paper is to show that if the provided Boolean function is incompletely defined, then the one-query and the two-query algorithms can be used as bounded-error quantum polynomial algorithms to identify certain classes of incompletely defined linear and affine Boolean functions respectively with probability of success at least 2/3.

  3. Recent numerical and algorithmic advances within the volume tracking framework for modeling interfacial flows

    DOE PAGES

    François, Marianne M.

    2015-05-28

    A review of recent advances made in numerical methods and algorithms within the volume tracking framework is presented. The volume tracking method, also known as the volume-of-fluid method has become an established numerical approach to model and simulate interfacial flows. Its advantage is its strict mass conservation. However, because the interface is not explicitly tracked but captured via the material volume fraction on a fixed mesh, accurate estimation of the interface position, its geometric properties and modeling of interfacial physics in the volume tracking framework remain difficult. Several improvements have been made over the last decade to address these challenges.more » In this study, the multimaterial interface reconstruction method via power diagram, curvature estimation via heights and mean values and the balanced-force algorithm for surface tension are highlighted.« less

  4. Low-Complexity Saliency Detection Algorithm for Fast Perceptual Video Coding

    PubMed Central

    Liu, Pengyu; Jia, Kebin

    2013-01-01

    A low-complexity saliency detection algorithm for perceptual video coding is proposed; low-level encoding information is adopted as the characteristics of visual perception analysis. Firstly, this algorithm employs motion vector (MV) to extract temporal saliency region through fast MV noise filtering and translational MV checking procedure. Secondly, spatial saliency region is detected based on optimal prediction mode distributions in I-frame and P-frame. Then, it combines the spatiotemporal saliency detection results to define the video region of interest (VROI). The simulation results validate that the proposed algorithm can avoid a large amount of computation work in the visual perception characteristics analysis processing compared with other existing algorithms; it also has better performance in saliency detection for videos and can realize fast saliency detection. It can be used as a part of the video standard codec at medium-to-low bit-rates or combined with other algorithms in fast video coding. PMID:24489495

  5. A fast Fourier transform on multipoles (FFTM) algorithm for solving Helmholtz equation in acoustics analysis.

    PubMed

    Ong, Eng Teo; Lee, Heow Pueh; Lim, Kian Meng

    2004-09-01

    This article presents a fast algorithm for the efficient solution of the Helmholtz equation. The method is based on the translation theory of the multipole expansions. Here, the speedup comes from the convolution nature of the translation operators, which can be evaluated rapidly using fast Fourier transform algorithms. Also, the computations of the translation operators are accelerated by using the recursive formulas developed recently by Gumerov and Duraiswami [SIAM J. Sci. Comput. 25, 1344-1381(2003)]. It is demonstrated that the algorithm can produce good accuracy with a relatively low order of expansion. Efficiency analyses of the algorithm reveal that it has computational complexities of O(Na), where a ranges from 1.05 to 1.24. However, this method requires substantially more memory to store the translation operators as compared to the fast multipole method. Hence, despite its simplicity in implementation, this memory requirement issue may limit the application of this algorithm to solving very large-scale problems.

  6. Visual saliency-based fast intracoding algorithm for high efficiency video coding

    NASA Astrophysics Data System (ADS)

    Zhou, Xin; Shi, Guangming; Zhou, Wei; Duan, Zhemin

    2017-01-01

    Intraprediction has been significantly improved in high efficiency video coding over H.264/AVC with quad-tree-based coding unit (CU) structure from size 64×64 to 8×8 and more prediction modes. However, these techniques cause a dramatic increase in computational complexity. An intracoding algorithm is proposed that consists of perceptual fast CU size decision algorithm and fast intraprediction mode decision algorithm. First, based on the visual saliency detection, an adaptive and fast CU size decision method is proposed to alleviate intraencoding complexity. Furthermore, a fast intraprediction mode decision algorithm with step halving rough mode decision method and early modes pruning algorithm is presented to selectively check the potential modes and effectively reduce the complexity of computation. Experimental results show that our proposed fast method reduces the computational complexity of the current HM to about 57% in encoding time with only 0.37% increases in BD rate. Meanwhile, the proposed fast algorithm has reasonable peak signal-to-noise ratio losses and nearly the same subjective perceptual quality.

  7. Effects of a fast-track area on emergency department performance.

    PubMed

    Sanchez, Miquel; Smally, Alan J; Grant, Robert J; Jacobs, Lenworth M

    2006-07-01

    To determine if a fast-track area (FTA) would improve Emergency Department (ED) performance, a historical cohort study was performed in the ED of a tertiary care adult hospital in the United States. Two 1-year consecutive periods, pre fast track area (FTA) opening-from February 1, 2001 to January 31, 2002 and after FTA opening-from February 1, 2002 to January 31, 2003 were studied. Daily values of the following variables were obtained from the ED patient tracking system: 1) To assess ED effectiveness: waiting time to be seen (WT), length of stay (LOS); 2) To assess ED care quality: rate of patients left without being seen (LWBS), mortality, and revisits; 3) To assess determinants of patient homogeneity between periods: daily census, age, acuity index, admission rate and emergent patient rate. For comparisons, the Wilcoxon test and the Student's t-test were used to analyze the data. Results showed that despite an increase in the daily census (difference [diff] 8.71, 95% confidence interval [CI] 6 to 11.41), FTA was associated with a decrease in WT (diff -51 min, 95% CI [-56 to -46]), LOS (diff -28 min, 95% CI [-31 to -23]) and LWBS (diff -4.06, 95% CI [-4.48 to -3.46]), without change in the rates of mortality or revisits. In conclusion, the opening of a FTA improved ED effectiveness, measured by decreased WT and LOS, without deterioration in the quality of care provided, measured by rates of mortality and revisits.

  8. GPU-Based Tracking Algorithms for the ATLAS High-Level Trigger

    NASA Astrophysics Data System (ADS)

    Emeliyanov, D.; Howard, J.

    2012-12-01

    Results on the performance and viability of data-parallel algorithms on Graphics Processing Units (GPUs) in the ATLAS Level 2 trigger system are presented. We describe the existing trigger data preparation and track reconstruction algorithms, motivation for their optimization, GPU-parallelized versions of these algorithms, and a “client-server” solution for hybrid CPU/GPU event processing used for integration of the GPU-oriented algorithms into existing ATLAS trigger software. The resulting speed-up of event processing times obtained with high-luminosity simulated data is presented and discussed.

  9. Development of Fast Algorithms Using Recursion, Nesting and Iterations for Computational Electromagnetics

    NASA Technical Reports Server (NTRS)

    Chew, W. C.; Song, J. M.; Lu, C. C.; Weedon, W. H.

    1995-01-01

    In the first phase of our work, we have concentrated on laying the foundation to develop fast algorithms, including the use of recursive structure like the recursive aggregate interaction matrix algorithm (RAIMA), the nested equivalence principle algorithm (NEPAL), the ray-propagation fast multipole algorithm (RPFMA), and the multi-level fast multipole algorithm (MLFMA). We have also investigated the use of curvilinear patches to build a basic method of moments code where these acceleration techniques can be used later. In the second phase, which is mainly reported on here, we have concentrated on implementing three-dimensional NEPAL on a massively parallel machine, the Connection Machine CM-5, and have been able to obtain some 3D scattering results. In order to understand the parallelization of codes on the Connection Machine, we have also studied the parallelization of 3D finite-difference time-domain (FDTD) code with PML material absorbing boundary condition (ABC). We found that simple algorithms like the FDTD with material ABC can be parallelized very well allowing us to solve within a minute a problem of over a million nodes. In addition, we have studied the use of the fast multipole method and the ray-propagation fast multipole algorithm to expedite matrix-vector multiplication in a conjugate-gradient solution to integral equations of scattering. We find that these methods are faster than LU decomposition for one incident angle, but are slower than LU decomposition when many incident angles are needed as in the monostatic RCS calculations.

  10. Fast track in colo-rectal surgery. Preliminary experience in a rural hospital

    PubMed Central

    FRONTERA, D.; ARENA, L.; CORSALE, I.; FRANCIOLI, N.; MAMMOLITI, F.; BUCCIANELLI, E.

    2014-01-01

    Background “Fast Track surgery” is a therapeutic program of large application, despite some doubts about its applicability and real validity. Literature review shows that this approach to colo-rectal surgery, particularly video-assisted, can allow a rapid recovery, better performance and a faster postoperative functional autonomy of the work, which can be discharged without cause additional welfare costs; in addition it can be reproducible in different health reality. Purpose To analyze the possibility to apply the Fast Truck protocol in patients undergoing colorectal surgery in a rural hospital and non specialistic Unit of Surgery. Patients and methods We have conducted a prospective, randomized study on 80 patients subjected to colorectal surgery in the last year. Results The protocol was observed in 95% of cases, compliance with the Fast Track was high and general morbidity was limited (7.8%). Conclusion This “aggressive” approach, which has fundamentally altered the usual surgical behavior, seems to allow a mean length of stay significantly lower than in controls (p < 0.05) with positive implications for patients and containment of health care costs, even after discharge (no need for home care in 92% of cases, no early re-admittance to the hospital). Homogeneous protocols are desirable, as well as an increased enrollment, to consolidate these rehabilitation programs in order to provide a reference for all hospitals. PMID:25644732

  11. A sequential Monte Carlo probability hypothesis density algorithm for multitarget track-before-detect

    NASA Astrophysics Data System (ADS)

    Punithakumar, K.; Kirubarajan, T.; Sinha, A.

    2005-09-01

    In this paper, we present a recursive track-before-detect (TBD) algorithm based on the Probability Hypothesis Density (PHD) filter for multitarget tracking. TBD algorithms are better suited over standard target tracking methods for tracking dim targets in heavy clutter and noise. Classical target tracking, where the measurements are pre-processed at each time step before passing them to the tracking filter results in information loss, which is very damaging if the target signal-to-noise ratio is low. However, in TBD the tracking filter operates directly on the raw measurements at the expense of added computational burden. The development of a recursive TBD algorithm reduces the computational burden over conventional TBD methods, namely, Hough transform, dynamic programming, etc. The TBD is a hard nonlinear non-Gaussian problem even for single target scenarios. Recent advances in Sequential Monte Carlo (SMC) based nonlinear filtering make multitarget TBD feasible. However, the current implementations use a modeling setup to accommodate the varying number of targets where a multiple model SMC based TBD approach is used to solve the problem conditioned on the model, i.e., number of targets. The PHD filter, which propagates only the first-order statistical moment (or the PHD) of the full target posterior, has been shown to be a computationally efficient solution to multitarget tracking problems with varying number of targets. We propose a PHD filter based TBD so that there is no assumption to be made on the number of targets. Simulation results are presented to show the effectiveness of the proposed filter in tracking multiple weak targets.

  12. Multi-User Identification-Based Eye-Tracking Algorithm Using Position Estimation

    PubMed Central

    Kang, Suk-Ju

    2016-01-01

    This paper proposes a new multi-user eye-tracking algorithm using position estimation. Conventional eye-tracking algorithms are typically suitable only for a single user, and thereby cannot be used for a multi-user system. Even though they can be used to track the eyes of multiple users, their detection accuracy is low and they cannot identify multiple users individually. The proposed algorithm solves these problems and enhances the detection accuracy. Specifically, the proposed algorithm adopts a classifier to detect faces for the red, green, and blue (RGB) and depth images. Then, it calculates features based on the histogram of the oriented gradient for the detected facial region to identify multiple users, and selects the template that best matches the users from a pre-determined face database. Finally, the proposed algorithm extracts the final eye positions based on anatomical proportions. Simulation results show that the proposed algorithm improved the average F1 score by up to 0.490, compared with benchmark algorithms. PMID:28035979

  13. Vectorized Rebinning Algorithm for Fast Data Down-Sampling

    NASA Technical Reports Server (NTRS)

    Dean, Bruce; Aronstein, David; Smith, Jeffrey

    2013-01-01

    A vectorized rebinning (down-sampling) algorithm, applicable to N-dimensional data sets, has been developed that offers a significant reduction in computer run time when compared to conventional rebinning algorithms. For clarity, a two-dimensional version of the algorithm is discussed to illustrate some specific details of the algorithm content, and using the language of image processing, 2D data will be referred to as "images," and each value in an image as a "pixel." The new approach is fully vectorized, i.e., the down-sampling procedure is done as a single step over all image rows, and then as a single step over all image columns. Data rebinning (or down-sampling) is a procedure that uses a discretely sampled N-dimensional data set to create a representation of the same data, but with fewer discrete samples. Such data down-sampling is fundamental to digital signal processing, e.g., for data compression applications.

  14. Joint tracking algorithm using particle filter and mean shift with target model updating

    NASA Astrophysics Data System (ADS)

    Zhang, Bo; Tian, Weifeng; Jin, Zhihua

    2006-10-01

    Roughly, visual tracking algorithms can be divided into two main classes: deterministic tracking and stochastic tracking. Mean shift and particle filter are their typical representatives, respectively. Recently, a hybrid tracker, seamlessly integrating the respective advantages of mean shift and particle filter (MSPF) has achieved impressive success in robust tracking. The pivot of MSPF is to sample fewer particles using particle filter and then those particles are shifted to their respective local maximum of target searching space by mean shift. MSPF not only can greatly reduce the number of particles that particle filter required, but can remedy the deficiency of mean shift. Unfortunately, due to its inherent principle, MSPF is restricted to those applications with little changes of the target model. To make MSPF more flexible and robust, an adaptive target model is extended to MSPF in this paper. Experimental results show that MSPF with target model updating can robustly track the target through the whole sequences regardless of the change of target model.

  15. Context exploitation in intelligence, surveillance, and reconnaissance for detection and tracking algorithms

    NASA Astrophysics Data System (ADS)

    Tucker, Jonathan D.; Stanfill, S. Robert

    2015-05-01

    Intelligence, Surveillance, and Reconnaissance (ISR) missions involve complex analysis of sensor data that can benefit from the exploitation of geographically aligned context. In this paper we discuss our approach to utilizing geo-registered imagery and context for the purpose of aiding ISR detection and tracking applications. Specifically this includes rendering context masks on imagery, increasing the speed at which detection algorithms process data, providing a way to intelligently control detection density for given ground areas, identifying difficult traffic terrain, refining peak suppression for congested areas, reducing target center of mass location errors, and increasing track coverage and duration through track prediction error robustness.

  16. Fast algorithm for automatically computing Strahler stream order

    USGS Publications Warehouse

    Lanfear, Kenneth J.

    1990-01-01

    An efficient algorithm was developed to determine Strahler stream order for segments of stream networks represented in a Geographic Information System (GIS). The algorithm correctly assigns Strahler stream order in topologically complex situations such as braided streams and multiple drainage outlets. Execution time varies nearly linearly with the number of stream segments in the network. This technique is expected to be particularly useful for studying the topology of dense stream networks derived from digital elevation model data.

  17. [Fast volume rendering of echocardiogram with shear-warp algorithm].

    PubMed

    Yang, Liu; Wang, Tianfu; Lin, Jiangli; Li, Deyu; Zheng, Yi; Zheng, Changqiong; Song, Haibo; Tang, Hong; Wang, Xiaoyi

    2004-04-01

    Shear-warp is a volume rendering technology based on object-order. It has the characteristics of high speed and high image quality by comparison with the conventional visualization technology. The authors introduced the principle of this algorithm and applied it to the visualization of 3-D data obtained by interpolating rotary scanning echocardiogram. The 3-D reconstruction of the echocardiogram was efficiently completed with high image quality. This algorithm has a prospective application in medical image visualization.

  18. Fast parallel algorithms for short-range molecular dynamics

    SciTech Connect

    Plimpton, S.

    1993-05-01

    Three parallel algorithms for classical molecular dynamics are presented. The first assigns each processor a subset of atoms; the second assigns each a subset of inter-atomic forces to compute; the third assigns each a fixed spatial region. The algorithms are suitable for molecular dynamics models which can be difficult to parallelize efficiently -- those with short-range forces where the neighbors of each atom change rapidly. They can be implemented on any distributed-memory parallel machine which allows for message-passing of data between independently executing processors. The algorithms are tested on a standard Lennard-Jones benchmark problem for system sizes ranging from 500 to 10,000,000 atoms on three parallel supercomputers, the nCUBE 2, Intel iPSC/860, and Intel Delta. Comparing the results to the fastest reported vectorized Cray Y-MP and C90 algorithm shows that the current generation of parallel machines is competitive with conventional vector supercomputers even for small problems. For large problems, the spatial algorithm achieves parallel efficiencies of 90% and the Intel Delta performs about 30 times faster than a single Y-MP processor and 12 times faster than a single C90 processor. Trade-offs between the three algorithms and guidelines for adapting them to more complex molecular dynamics simulations are also discussed.

  19. Atom ejection from a fast-ion track: A molecular-dynamics study

    SciTech Connect

    Urbassek, H.M. ); Kafemann, H. ); Johnson, R.E. )

    1994-01-01

    As a model for atom ejection from fast-ion tracks, molecular-dynamics simulations of a cylindrical track of energized particles are performed. An idealized situation is studied where every atom in a cylindrical track of radius [ital R][sub 0] is energized with energy [ital E][sub 0]. The emission yield [ital Y]([ital E][sub 0],[ital R][sub 0]) shows the existence of two ejection regimes. If the particle energy [ital E][sub 0] is below the sublimation energy [ital U] of the material, a threshold regime is seen in which [ital Y] rises roughly like the third power of [ital E][sub 0]; for high-energy densities [ital E][sub 0][approx gt][ital U], the yield rises much more slowly, roughly linearly. In both cases, ejected particles mostly originate from the track, rather than from its surroundings, and from the first or the first few monolayers. The behavior found is interpreted here in terms of emission due to a pressure-driven jet (linear regime) or due to a pressure pulse (threshold regime). These both behave differently from the often-used thermal-spike sputtering model.

  20. Fast detection of alpha particles in DAM-ADC nuclear track detectors

    NASA Astrophysics Data System (ADS)

    Rammah, Y. S.; Ashraf, O.; Abdalla, A. M.; Eisa, M.; Ashry, A. H.; Tsuruta, T.

    2015-02-01

    Fast detection of alpha particles in DAM-ADC nuclear track detectors using a new chemical etchant was investigated. 252Cf and 241Am sources were used for irradiating samples of DAM-ADC SSNTDs with fission fragments and alpha particles in air at normal temperature and pressure. A series of experimental chemical etching are carried out using new etching solution (8 ml of 10 N NaOH+ 1 ml CH3OH) at 60 °C to detect alpha particle in short time in DAM-ADC detectors. Suitable analyzing software has been used to analyze experimental data. From fission and alpha track diameters, the value of bulk etching rate is equal to 8.52 μm/h. Both of the sensitivity and etching efficiency were found to vary with the amount of methanol in the etching solution and etching time. The DAM-ADC detectors represent the best efficiency applicable in detectors in the entire range of alpha energies (from 1 to 5 MeV). The activation energies of this etchant have been calculated; track activation energy, ET, has been found to be lower than the bulk activation energy, EB, for the DAM-ADC nuclear track detectors. These results are in more agreement with the previous work.

  1. Algorithm For Simplified Robotic Tracking Of Weld Seams

    NASA Technical Reports Server (NTRS)

    Gutow, David A.; Paternoster, Vincent Y.

    1992-01-01

    Algorithm computes small cross-seam corrections to programmed path of welding robot. Intended for use with add-on vision system loosely coupled to robot, transmitting small amount of information about weld seam ahead of torch. Position of welding torch in reference frame of moving window estimated on basis of data on weld seam and speed of torch. Does not need data on position of torch, and does not transform data on seam to another reference frame.

  2. Does BMI influence hospital stay and morbidity after fast-track hip and knee arthroplasty?

    PubMed

    Husted, Henrik; Jørgensen, Christoffer C; Gromov, Kirill; Kehlet, Henrik

    2016-10-01

    Background and purpose - Body mass index (BMI) outside the normal range possibly affects the perioperative morbidity and mortality following total hip arthroplasty (THA) and total knee arthroplasty (TKA) in traditional care programs. We determined perioperative morbidity and mortality in such patients who were operated with the fast-track methodology and compared the levels with those in patients with normal BMI. Patients and methods - This was a prospective observational study involving 13,730 procedures (7,194 THA and 6,536 TKA operations) performed in a standardized fast-track setting. Complete 90-day follow-up was achieved using national registries and review of medical records. Patients were grouped according to BMI as being underweight, of normal weight, overweight, obese, very obese, and morbidly obese. Results - Median length of stay (LOS) was 2 (IQR: 2-3) days in all BMI groups. 30-day re-admission rates were around 6% for both THA (6.1%) and TKA (5.9%), without any statistically significant differences between BMI groups in univariate analysis (p > 0.4), but there was a trend of a protective effect of overweight for both THA (p = 0.1) and TKA (p = 0.06). 90-day re-admission rates increased to 8.6% for THA and 8.3% for TKA, which was similar among BMI groups, but there was a trend of lower rates in overweight and obese TKA patients (p = 0.08 and p = 0.06, respectively). When we adjusted for preoperative comorbidity, high BMI in THA patients (very obese and morbidly obese patients only) was associated with a LOS of >4 days (p = 0.001), but not with re-admission. No such relationship existed for TKA. Interpretation - A fast-track setting resulted in similar length of hospital stay and re-admission rates regardless of BMI, except for very obese and morbidly obese THA patients.

  3. An algorithm for unfolding neutron dose and dose equivalent from digitized recoil-particle tracks

    SciTech Connect

    Bolch, W.E.; Turner, J.E.; Hamm, R.N.

    1986-10-01

    Previous work had demonstrated the feasibility of a digital approach to neutron dosimetry. A Monte Carlo simulation code of one detector design utilizing the operating principles of time-projection chambers was completed. This thesis presents and verifies one version of the dosimeter's computer algorithm. This algorithm processes the output of the ORNL simulation code, but is applicable to all detectors capable of digitizing recoil-particle tracks. Key features include direct measurement of track lengths and identification of particle type for each registered event. The resulting dosimeter should allow more accurate determinations of neutron dose and dose equivalent compared with conventional dosimeters, which cannot measure these quantities directly. Verification of the algorithm was accomplished by running a variety of recoil particles through the simulated detector volume and comparing the resulting absorbed dose and dose equivalent to those unfolded by the algorithm.

  4. A High-Speed Vision-Based Sensor for Dynamic Vibration Analysis Using Fast Motion Extraction Algorithms.

    PubMed

    Zhang, Dashan; Guo, Jie; Lei, Xiujun; Zhu, Changan

    2016-04-22

    The development of image sensor and optics enables the application of vision-based techniques to the non-contact dynamic vibration analysis of large-scale structures. As an emerging technology, a vision-based approach allows for remote measuring and does not bring any additional mass to the measuring object compared with traditional contact measurements. In this study, a high-speed vision-based sensor system is developed to extract structure vibration signals in real time. A fast motion extraction algorithm is required for this system because the maximum sampling frequency of the charge-coupled device (CCD) sensor can reach up to 1000 Hz. Two efficient subpixel level motion extraction algorithms, namely the modified Taylor approximation refinement algorithm and the localization refinement algorithm, are integrated into the proposed vision sensor. Quantitative analysis shows that both of the two modified algorithms are at least five times faster than conventional upsampled cross-correlation approaches and achieve satisfactory error performance. The practicability of the developed sensor is evaluated by an experiment in a laboratory environment and a field test. Experimental results indicate that the developed high-speed vision-based sensor system can extract accurate dynamic structure vibration signals by tracking either artificial targets or natural features.

  5. A High-Speed Vision-Based Sensor for Dynamic Vibration Analysis Using Fast Motion Extraction Algorithms

    PubMed Central

    Zhang, Dashan; Guo, Jie; Lei, Xiujun; Zhu, Changan

    2016-01-01

    The development of image sensor and optics enables the application of vision-based techniques to the non-contact dynamic vibration analysis of large-scale structures. As an emerging technology, a vision-based approach allows for remote measuring and does not bring any additional mass to the measuring object compared with traditional contact measurements. In this study, a high-speed vision-based sensor system is developed to extract structure vibration signals in real time. A fast motion extraction algorithm is required for this system because the maximum sampling frequency of the charge-coupled device (CCD) sensor can reach up to 1000 Hz. Two efficient subpixel level motion extraction algorithms, namely the modified Taylor approximation refinement algorithm and the localization refinement algorithm, are integrated into the proposed vision sensor. Quantitative analysis shows that both of the two modified algorithms are at least five times faster than conventional upsampled cross-correlation approaches and achieve satisfactory error performance. The practicability of the developed sensor is evaluated by an experiment in a laboratory environment and a field test. Experimental results indicate that the developed high-speed vision-based sensor system can extract accurate dynamic structure vibration signals by tracking either artificial targets or natural features. PMID:27110784

  6. "Fast-Tracking": Ain't No Golden Parachute So Don't Slide off the Rainbow.

    ERIC Educational Resources Information Center

    Newburger, Craig; Butler, Jerry

    Awareness of the corporate cultural phenomenon of fast-tracking, a process whereby executives are advanced within and among organizations, should assist communication students and practicing professionals to become more effective corporate communicators. A critical distinction between self-directed fast-trackers and their corporately-sanctioned…

  7. Assessing the accuracy of image tracking algorithms on visible and thermal imagery using a deep restricted Boltzmann machine

    NASA Astrophysics Data System (ADS)

    Won, Stephen; Young, S. Susan

    2012-06-01

    Image tracking algorithms are critical to many applications including image super-resolution and surveillance. However, there exists no method to independently verify the accuracy of the tracking algorithm without a supplied control or visual inspection. This paper proposes an image tracking framework that uses deep restricted Boltzmann machines trained without external databases to quantify the accuracy of image tracking algorithms without the use of ground truths. In this paper, the tracking algorithm is comprised of the combination of flux tensor segmentation with four image registration methods, including correlation, Horn-Schunck optical flow, Lucas-Kanade optical flow, and feature correspondence methods. The robustness of the deep restricted Boltzmann machine is assessed by comparing between results from training with trusted and not-trusted data. Evaluations show that the deep restricted Boltzmann machine is a valid mechanism to assess the accuracy of a tracking algorithm without the use of ground truths.

  8. Fast Combinatorial Algorithm for the Solution of Linearly Constrained Least Squares Problems

    DOEpatents

    Van Benthem, Mark H.; Keenan, Michael R.

    2008-11-11

    A fast combinatorial algorithm can significantly reduce the computational burden when solving general equality and inequality constrained least squares problems with large numbers of observation vectors. The combinatorial algorithm provides a mathematically rigorous solution and operates at great speed by reorganizing the calculations to take advantage of the combinatorial nature of the problems to be solved. The combinatorial algorithm exploits the structure that exists in large-scale problems in order to minimize the number of arithmetic operations required to obtain a solution.

  9. Fast Track to the Cloud: Design Patterns for 12-Factor Earth Sciences Applications

    NASA Technical Reports Server (NTRS)

    Pawloski, Andrew; McLaughlin, Brett; Lynnes, Christopher

    2016-01-01

    As expanding service offerings and decreasing prices make the cloud increasingly attractive to Earth Science applications, there are nontrivial practical considerations which can hinder its meaningful use. In this talk, we will discuss architectural recommendations and lessons learned while working on EOSDIS' cloud efforts, particularly the NASA-compliant General Application Platform (NGAP) and its associated applications. Prominent in our findings is the importance of 12-factor design patterns and the powerful "wins" they enable in the cloud. We will share our strategies for "fast-tracking" applications to the cloud --whether they be legacy, planned for the future, or somewhere in between.

  10. Fast computation algorithm for the Rayleigh-Sommerfeld diffraction formula using a type of scaled convolution.

    PubMed

    Nascov, Victor; Logofătu, Petre Cătălin

    2009-08-01

    We describe a fast computational algorithm able to evaluate the Rayleigh-Sommerfeld diffraction formula, based on a special formulation of the convolution theorem and the fast Fourier transform. What is new in our approach compared to other algorithms is the use of a more general type of convolution with a scale parameter, which allows for independent sampling intervals in the input and output computation windows. Comparison between the calculations made using our algorithm and direct numeric integration show a very good agreement, while the computation speed is increased by orders of magnitude.

  11. How Does the Fast Track Intervention Prevent Adverse Outcomes in Young Adulthood?

    PubMed Central

    Sorensen, Lucy C.; Dodge, Kenneth A.

    2015-01-01

    Numerous studies have shown that childhood interventions can foster improved outcomes in adulthood. Less well understood is precisely how – that is, through which developmental pathways – these interventions work. This study assesses mechanisms by which the Fast Track project (n=891), a randomized intervention in the early 1990s for high-risk children in four communities (Durham, NC; Nashville, TN; rural PA; and Seattle, WA), reduced delinquency, arrests, and health and mental health service utilization in adolescence through young adulthood (ages 12–20). A decomposition of treatment effects indicates that about a third of Fast Track’s impact on later crime outcomes can be accounted for by improvements in social and self-regulation skills during childhood (ages 6–11), such as prosocial behavior, emotion regulation and problem solving. These skills proved less valuable for the prevention of mental and physical health problems. PMID:26670938

  12. Fast Outlier Detection Using a Grid-Based Algorithm.

    PubMed

    Lee, Jihwan; Cho, Nam-Wook

    2016-01-01

    As one of data mining techniques, outlier detection aims to discover outlying observations that deviate substantially from the reminder of the data. Recently, the Local Outlier Factor (LOF) algorithm has been successfully applied to outlier detection. However, due to the computational complexity of the LOF algorithm, its application to large data with high dimension has been limited. The aim of this paper is to propose grid-based algorithm that reduces the computation time required by the LOF algorithm to determine the k-nearest neighbors. The algorithm divides the data spaces in to a smaller number of regions, called as a "grid", and calculates the LOF value of each grid. To examine the effectiveness of the proposed method, several experiments incorporating different parameters were conducted. The proposed method demonstrated a significant computation time reduction with predictable and acceptable trade-off errors. Then, the proposed methodology was successfully applied to real database transaction logs of Korea Atomic Energy Research Institute. As a result, we show that for a very large dataset, the grid-LOF can be considered as an acceptable approximation for the original LOF. Moreover, it can also be effectively used for real-time outlier detection.

  13. A target group tracking algorithm for wireless sensor networks using azimuthal angle of arrival information

    NASA Astrophysics Data System (ADS)

    Zhang, Chun; Fei, Shu-Min; Zhou, Xing-Peng

    2012-12-01

    In this paper, we explore the technology of tracking a group of targets with correlated motions in a wireless sensor network. Since a group of targets moves collectively and is restricted within a limited region, it is not worth consuming scarce resources of sensors in computing the trajectory of each single target. Hence, in this paper, the problem is modeled as tracking a geographical continuous region covered by all targets. A tracking algorithm is proposed to estimate the region covered by the target group in each sampling period. Based on the locations of sensors and the azimuthal angle of arrival (AOA) information, the estimated region covering all the group members is obtained. Algorithm analysis provides the fundamental limits to the accuracy of localizing a target group. Simulation results show that the proposed algorithm is superior to the existing hull algorithm due to the reduction in estimation error, which is between 10% and 40% of the hull algorithm, with a similar density of sensors. And when the density of sensors increases, the localization accuracy of the proposed algorithm improves dramatically.

  14. Outline of a fast hardware implementation of Winograd's DFT algorithm

    NASA Technical Reports Server (NTRS)

    Zohar, S.

    1980-01-01

    The main characteristics of the discrete Fourier transform (DFT) algorithm considered by Winograd (1976) is a significant reduction in the number of multiplications. Its primary disadvantage is a higher structural complexity. It is, therefore, difficult to translate the reduced number of multiplications into faster execution of the DFT by means of a software implementation of the algorithm. For this reason, a hardware implementation is considered in the current study, taking into account a design based on the algorithm prescription discussed by Zohar (1979). The hardware implementation of a FORTRAN subroutine is proposed, giving attention to a pipelining scheme in which 5 consecutive data batches are being operated on simultaneously, each batch undergoing one of 5 processing phases.

  15. Fast parallel algorithms: from images to level sets and labels

    NASA Astrophysics Data System (ADS)

    Nguyen, H. T.; Jung, Ken K.; Raghavan, Raghu

    1990-07-01

    Decomposition into level sets refers to assigning a code with respect to intensity or elevation while labeling refers to assigning a code with respect to disconnected regions. We present a sequence of parallel algorithms for these two processes. The process of labeling includes re-assign labels into a natural sequence and compare different labeling algorithm. We discuss the difference between edge-based and region-based labeling. The speed improvements in this labeling scheme come from the collective efficiency of different techniques. We have implemented these algorithms on an in-house built Geometric Single Instruction Multiple Data (GSIMD) parallel machine with global buses and a Multiple Instruction Multiple Data (MIMD) controller. This allows real time image interpretation on live data at a rate that is much higher than video rate. The performance figures will be shown.

  16. Gradient maintenance: A new algorithm for fast online replanning

    SciTech Connect

    Ahunbay, Ergun E. Li, X. Allen

    2015-06-15

    Purpose: Clinical use of online adaptive replanning has been hampered by the unpractically long time required to delineate volumes based on the image of the day. The authors propose a new replanning algorithm, named gradient maintenance (GM), which does not require the delineation of organs at risk (OARs), and can enhance automation, drastically reducing planning time and improving consistency and throughput of online replanning. Methods: The proposed GM algorithm is based on the hypothesis that if the dose gradient toward each OAR in daily anatomy can be maintained the same as that in the original plan, the intended plan quality of the original plan would be preserved in the adaptive plan. The algorithm requires a series of partial concentric rings (PCRs) to be automatically generated around the target toward each OAR on the planning and the daily images. The PCRs are used in the daily optimization objective function. The PCR dose constraints are generated with dose–volume data extracted from the original plan. To demonstrate this idea, GM plans generated using daily images acquired using an in-room CT were compared to regular optimization and image guided radiation therapy repositioning plans for representative prostate and pancreatic cancer cases. Results: The adaptive replanning using the GM algorithm, requiring only the target contour from the CT of the day, can be completed within 5 min without using high-power hardware. The obtained adaptive plans were almost as good as the regular optimization plans and were better than the repositioning plans for the cases studied. Conclusions: The newly proposed GM replanning algorithm, requiring only target delineation, not full delineation of OARs, substantially increased planning speed for online adaptive replanning. The preliminary results indicate that the GM algorithm may be a solution to improve the ability for automation and may be especially suitable for sites with small-to-medium size targets surrounded by

  17. A fast non-local image denoising algorithm

    NASA Astrophysics Data System (ADS)

    Dauwe, A.; Goossens, B.; Luong, H. Q.; Philips, W.

    2008-02-01

    In this paper we propose several improvements to the original non-local means algorithm introduced by Buades et al. which obtains state-of-the-art denoising results. The strength of this algorithm is to exploit the repetitive character of the image in order to denoise the image unlike conventional denoising algorithms, which typically operate in a local neighbourhood. Due to the enormous amount of weight computations, the original algorithm has a high computational cost. An improvement of image quality towards the original algorithm is to ignore the contributions from dissimilar windows. Even though their weights are very small at first sight, the new estimated pixel value can be severely biased due to the many small contributions. This bad influence of dissimilar windows can be eliminated by setting their corresponding weights to zero. Using the preclassification based on the first three statistical moments, only contributions from similar neighborhoods are computed. To decide whether a window is similar or dissimilar, we will derive thresholds for images corrupted with additive white Gaussian noise. Our accelerated approach is further optimized by taking advantage of the symmetry in the weights, which roughly halves the computation time, and by using a lookup table to speed up the weight computations. Compared to the original algorithm, our proposed method produces images with increased PSNR and better visual performance in less computation time. Our proposed method even outperforms state-of-the-art wavelet denoising techniques in both visual quality and PSNR values for images containing a lot of repetitive structures such as textures: the denoised images are much sharper and contain less artifacts. The proposed optimizations can also be applied in other image processing tasks which employ the concept of repetitive structures such as intra-frame super-resolution or detection of digital image forgery.

  18. A Simple and Fast Spline Filtering Algorithm for Surface Metrology.

    PubMed

    Zhang, Hao; Ott, Daniel; Song, John; Tong, Mingsi; Chu, Wei

    2015-01-01

    Spline filters and their corresponding robust filters are commonly used filters recommended in ISO (the International Organization for Standardization) standards for surface evaluation. Generally, these linear and non-linear spline filters, composed of symmetric, positive-definite matrices, are solved in an iterative fashion based on a Cholesky decomposition. They have been demonstrated to be relatively efficient, but complicated and inconvenient to implement. A new spline-filter algorithm is proposed by means of the discrete cosine transform or the discrete Fourier transform. The algorithm is conceptually simple and very convenient to implement.

  19. TRACC: Algorithm for Predicting and Tracking Barges on Inland Waterways

    SciTech Connect

    Randeniya, Duminda I.B.

    2010-04-23

    Algorithm developed in this work is used to predict the location and estimate the traveling speed of a barge moving in inland waterway network. Measurements obtained from GPS or other systems are corrupted with measurement noise and reported at large, irregular time intervals. Thus, creating uncertainty about the current location of the barge and minimizing the effectiveness of emergency response activities in case of an accident or act of terrorism. Developing a prediction algorithm become a non-trivial problem due to estimation of speed becomes challenging, attributed to the complex interactions between multiple systems associated in the process. This software, uses systems approach in modeling the motion dynamics of the barge and estimates the location and speed of the barge at next, user defined, time interval. In this work, first, to estimate the speed a non-linear, stochastic modeling technique was developed that take local variations and interactions existing in the system. Output speed is then used as an observation in a statistically optimal filtering technique, Kalman filter, formulated in state-space to minimize numerous errors observed in the system. The combined system synergistically fuses the local information available with measurements obtained to predict the location and speed of traveling of the barge accurately.

  20. Performance Evaluation of Algorithms in Lung IMRT: A comparison of Monte Carlo, Pencil Beam, Superposition, Fast Superposition and Convolution Algorithms

    PubMed Central

    Verma, T.; Painuly, N.K.; Mishra, S.P.; Shajahan, M.; Singh, N.; Bhatt, M.L.B.; Jamal, N.; Pant, M.C.

    2016-01-01

    Background: Inclusion of inhomogeneity corrections in intensity modulated small fields always makes conformal irradiation of lung tumor very complicated in accurate dose delivery. Objective: In the present study, the performance of five algorithms via Monte Carlo, Pencil Beam, Convolution, Fast Superposition and Superposition were evaluated in lung cancer Intensity Modulated Radiotherapy planning. Materials and Methods: Treatment plans for ten lung cancer patients previously planned on Monte Carlo algorithm were re-planned using same treatment planning indices (gantry angel, rank, power etc.) in other four algorithms. Results: The values of radiotherapy planning parameters such as Mean dose, volume of 95% isodose line, Conformity Index, Homogeneity Index for target, Maximum dose, Mean dose; %Volume receiving 20Gy or more by contralateral lung; % volume receiving 30 Gy or more; % volume receiving 25 Gy or more, Mean dose received by heart; %volume receiving 35Gy or more; %volume receiving 50Gy or more, Mean dose to Easophagous; % Volume receiving 45Gy or more, Maximum dose received by Spinal cord and Total monitor unit, Volume of 50 % isodose lines were recorded for all ten patients. Performance of different algorithms was also evaluated statistically. Conclusion: MC and PB algorithms found better as for tumor coverage, dose distribution homogeneity in Planning Target Volume and minimal dose to organ at risks are concerned. Superposition algorithms found to be better than convolution and fast superposition. In the case of tumors located centrally, it is recommended to use Monte Carlo algorithms for the optimal use of radiotherapy. PMID:27853720

  1. Dim moving target tracking algorithm based on particle discriminative sparse representation

    NASA Astrophysics Data System (ADS)

    Li, Zhengzhou; Li, Jianing; Ge, Fengzeng; Shao, Wanxing; Liu, Bing; Jin, Gang

    2016-03-01

    The small dim moving target usually submerged in strong noise, and its motion observability is debased by numerous false alarms for low signal-to-noise ratio (SNR). A target tracking algorithm based on particle filter and discriminative sparse representation is proposed in this paper to cope with the uncertainty of dim moving target tracking. The weight of every particle is the crucial factor to ensuring the accuracy of dim target tracking for particle filter (PF) that can achieve excellent performance even under the situation of non-linear and non-Gaussian motion. In discriminative over-complete dictionary constructed according to image sequence, the target dictionary describes target signal and the background dictionary embeds background clutter. The difference between target particle and background particle is enhanced to a great extent, and the weight of every particle is then measured by means of the residual after reconstruction using the prescribed number of target atoms and their corresponding coefficients. The movement state of dim moving target is then estimated and finally tracked by these weighted particles. Meanwhile, the subspace of over-complete dictionary is updated online by the stochastic estimation algorithm. Some experiments are induced and the experimental results show the proposed algorithm could improve the performance of moving target tracking by enhancing the consistency between the posteriori probability distribution and the moving target state.

  2. "Fast track surgery" in the north-west of Italy: influence on the orientation of surgical practice.

    PubMed

    Pozzi, G; Falcone, A; Sabbatino, F; Solej, M; Nano, M

    2012-06-01

    Fast track surgery is a peri-operative management model, including different strategies to improve patients' convalescence, avoid metabolic alterations, reduce complications, and shorten hospital stay. Prerequisite is coordination between different practitioners (surgeon, anaesthetist, nurse, nutritionist, physiotherapist). The purpose of our investigation is to understand the level of fast track surgery application in Piedmont and to evidence analogies and differences among departments. We projected an investigation proposing, to every surgery department in Piedmont, a multiple-choice questionnaire evaluating the level of fast track surgery peri-operative interventions' application. Data analysis was conducted in two points of view: the transversal one with an overview of answer's percentages, the longitudinal one correlating data through Pearson's index (r). We collected answers by 78 % of balloted departments (38 on 49). Transversal analysis, including the evaluation of percentages of each question, shows that intra-operative period is the most influenced by fast track principles, and that only 12 departments of 38 apply complete protocols. Longitudinal analysis, estimating the whole of each department's answers, demonstrates the absence of statistical significance in the correlation between fast track surgery application and territorial (r = 0.18), economic (r = 0.31), or age (r = 0.06) variables. Influence of fast track surgery is significantly present in our territory, even though it is not fully concretized in protocols. The choice of fast track depends on the instruction, the environment and the sensibility of each surgeon. Knowledge of geographic distribution of departments applying this model can be useful to organize common protocols, starting from more experienced hospitals.

  3. Fast Quantum Algorithms for Numerical Integrals and Stochastic Processes

    NASA Technical Reports Server (NTRS)

    Abrams, D.; Williams, C.

    1999-01-01

    We discuss quantum algorithms that calculate numerical integrals and descriptive statistics of stochastic processes. With either of two distinct approaches, one obtains an exponential speed increase in comparison to the fastest known classical deterministic algotithms and a quadratic speed increase incomparison to classical Monte Carlo methods.

  4. Attitude determination using vector observations - A fast optimal matrix algorithm

    NASA Technical Reports Server (NTRS)

    Markley, F. L.

    1993-01-01

    The attitude matrix minimizing Wahba's loss function is computed directly by a method that is competitive with the fastest known algorithm for finding this optimal estimate. The method also provides an estimate of the attitude error covariance matrix. Analysis of the special case of two vector observations identifies those cases for which the TRIAD or algebraic method minimizes Wahba's loss function.

  5. Attitude determination using vector observations: A fast optimal matrix algorithm

    NASA Technical Reports Server (NTRS)

    Markley, F. Landis

    1993-01-01

    The attitude matrix minimizing Wahba's loss function is computed directly by a method that is competitive with the fastest known algorithm for finding this optimal estimate. The method also provides an estimate of the attitude error covariance matrix. Analysis of the special case of two vector observations identifies those cases for which the TRIAD or algebraic method minimizes Wahba's loss function.

  6. An Iterative CT Reconstruction Algorithm for Fast Fluid Flow Imaging.

    PubMed

    Van Eyndhoven, Geert; Batenburg, K Joost; Kazantsev, Daniil; Van Nieuwenhove, Vincent; Lee, Peter D; Dobson, Katherine J; Sijbers, Jan

    2015-11-01

    The study of fluid flow through solid matter by computed tomography (CT) imaging has many applications, ranging from petroleum and aquifer engineering to biomedical, manufacturing, and environmental research. To avoid motion artifacts, current experiments are often limited to slow fluid flow dynamics. This severely limits the applicability of the technique. In this paper, a new iterative CT reconstruction algorithm for improved a temporal/spatial resolution in the imaging of fluid flow through solid matter is introduced. The proposed algorithm exploits prior knowledge in two ways. First, the time-varying object is assumed to consist of stationary (the solid matter) and dynamic regions (the fluid flow). Second, the attenuation curve of a particular voxel in the dynamic region is modeled by a piecewise constant function over time, which is in accordance with the actual advancing fluid/air boundary. Quantitative and qualitative results on different simulation experiments and a real neutron tomography data set show that, in comparison with the state-of-the-art algorithms, the proposed algorithm allows reconstruction from substantially fewer projections per rotation without image quality loss. Therefore, the temporal resolution can be substantially increased, and thus fluid flow experiments with faster dynamics can be performed.

  7. Hierarchical data visualization using a fast rectangle-packing algorithm.

    PubMed

    Itoh, Takayuki; Yamaguchi, Yumi; Ikehata, Yuko; Kajinaga, Yasumasa

    2004-01-01

    This paper presents a technique for the representation of large-scale hierarchical data which aims to provide good overviews of complete structures and the content of the data in one display space. The technique represents the data by using nested rectangles. It first packs icons or thumbnails of the lowest-level data and then generates rectangular borders that enclose the packed data. It repeats the process of generating rectangles that enclose the lower-level rectangles until the highest-level rectangles are packed. This paper presents two rectangle-packing algorithms for placing items of hierarchical data onto display spaces. The algorithms refer to Delaunay triangular meshes connecting the centers of rectangles to find gaps where rectangles can be placed. The first algorithm places rectangles where they do not overlap each other and where the extension of the layout area is minimal. The second algorithm places rectangles by referring to templates describing the ideal positions for nodes of input data. It places rectangles where they do not overlap each other and where the combination of the layout area and the distances between the positions described in the template and the actual positions is minimal. It can smoothly represent time-varying data by referring to templates that describe previous layout results. It is also suitable for semantics-based or design-based data layout by generating templates according to the semantics or design.

  8. Fast Multiscale Algorithms for Information Representation and Fusion

    DTIC Science & Technology

    2012-07-01

    4 5.1 Experiment: LIDAR Dataset (MSVD using nearest neighbors...implementation of the new multiscale SVD (MSVD) algorithms. We applied the MSVD to a publicly available LIDAR dataset for the purposes of distinguishing...between vegetation and the forest floor. The final results are presented in this report (initial results were reported in the previous quarterly report

  9. An application of fast algorithms to numerical electromagnetic modeling

    SciTech Connect

    Bezvoda, V.; Segeth, K.

    1987-03-01

    Numerical electromagnetic modeling by the finite-difference or finite-element methods leads to a large sparse system of linear algebraic equations. Fast direct methods, requiring an order of at most q log q arithmetic operations to solve a system of q equations, cannot easily be applied to such a system. This paper describes the iterative application of a fast method, namely cyclic reduction, to the numerical solution of the Helmholtz equation with a piecewise constant imaginary coefficient of the absolute term in a plane domain. By means of numerical tests the advantages and limitations of the method compared with classical direct methods are discussed. The iterative application of the cyclic reduction method is very efficient if one can exploit a known solution of a similar (e.g., simpler) problem as the initial approximation. This makes cyclic reduction a powerful tool in solving the inverse problem by trial-and-error.

  10. Through-Wall Multiple Targets Vital Signs Tracking Based on VMD Algorithm

    PubMed Central

    Yan, Jiaming; Hong, Hong; Zhao, Heng; Li, Yusheng; Gu, Chen; Zhu, Xiaohua

    2016-01-01

    Targets located at the same distance are easily neglected in most through-wall multiple targets detecting applications which use the single-input single-output (SISO) ultra-wideband (UWB) radar system. In this paper, a novel multiple targets vital signs tracking algorithm for through-wall detection using SISO UWB radar has been proposed. Taking advantage of the high-resolution decomposition of the Variational Mode Decomposition (VMD) based algorithm, the respiration signals of different targets can be decomposed into different sub-signals, and then, we can track the time-varying respiration signals accurately when human targets located in the same distance. Intensive evaluation has been conducted to show the effectiveness of our scheme with a 0.15 m thick concrete brick wall. Constant, piecewise-constant and time-varying vital signs could be separated and tracked successfully with the proposed VMD based algorithm for two targets, even up to three targets. For the multiple targets’ vital signs tracking issues like urban search and rescue missions, our algorithm has superior capability in most detection applications. PMID:27537880

  11. Tracking Problem Solving by Multivariate Pattern Analysis and Hidden Markov Model Algorithms

    ERIC Educational Resources Information Center

    Anderson, John R.

    2012-01-01

    Multivariate pattern analysis can be combined with Hidden Markov Model algorithms to track the second-by-second thinking as people solve complex problems. Two applications of this methodology are illustrated with a data set taken from children as they interacted with an intelligent tutoring system for algebra. The first "mind reading" application…

  12. Least average residual algorithm (LARA) for tracking the motion of Arctic sea ice

    SciTech Connect

    Das Peddada, S.; McDevitt, R.

    1996-07-01

    Suppose one has two images A and B of a collection of ice floes taken at times t{sub 0} and t{sub 1}, respectively. Given an ice flow 1 in A, the authors develop a new automated tracking algorithm to track the position of A in image B. The proposed least average residual algorithm (LARA) performs a constrained search for matching ice floes by determining an appropriate search space for each floe to be tracked. LARA takes a stepwide approach with suitable decision rules at various stages. It takes into account various distinguishing characteristics such as: (i) the geometry of the ice field; (ii) size of an ice floe; and (iii) geometry of the floe. LARA also attempts to detect broken floes and amalgamated floes.

  13. A quality-guided displacement tracking algorithm for ultrasonic elasticity imaging.

    PubMed

    Chen, Lujie; Treece, Graham M; Lindop, Joel E; Gee, Andrew H; Prager, Richard W

    2009-04-01

    Displacement estimation is a key step in the evaluation of tissue elasticity by quasistatic strain imaging. An efficient approach may incorporate a tracking strategy whereby each estimate is initially obtained from its neighbours' displacements and then refined through a localized search. This increases the accuracy and reduces the computational expense compared with exhaustive search. However, simple tracking strategies fail when the target displacement map exhibits complex structure. For example, there may be discontinuities and regions of indeterminate displacement caused by decorrelation between the pre- and post-deformation radio frequency (RF) echo signals. This paper introduces a novel displacement tracking algorithm, with a search strategy guided by a data quality indicator. Comparisons with existing methods show that the proposed algorithm is more robust when the displacement distribution is challenging.

  14. A Linac Simulation Code for Macro-Particles Tracking and Steering Algorithm Implementation

    SciTech Connect

    sun, yipeng

    2012-05-03

    In this paper, a linac simulation code written in Fortran90 is presented and several simulation examples are given. This code is optimized to implement linac alignment and steering algorithms, and evaluate the accelerator errors such as RF phase and acceleration gradient, quadrupole and BPM misalignment. It can track a single particle or a bunch of particles through normal linear accelerator elements such as quadrupole, RF cavity, dipole corrector and drift space. One-to-one steering algorithm and a global alignment (steering) algorithm are implemented in this code.

  15. Modeling optical pattern recognition algorithms for object tracking based on nonlinear equivalent models and subtraction of frames

    NASA Astrophysics Data System (ADS)

    Krasilenko, Vladimir G.; Nikolskyy, Aleksandr I.; Lazarev, Alexander A.

    2015-12-01

    We have proposed and discussed optical pattern recognition algorithms for object tracking based on nonlinear equivalent models and subtraction of frames. Experimental results of suggested algorithms in Mathcad and LabVIEW are shown. Application of equivalent functions and difference of frames gives good results for recognition and tracking moving objects.

  16. A Fast Implementation of the ISODATA Clustering Algorithm

    NASA Technical Reports Server (NTRS)

    Memarsadeghi, Nargess; Mount, David M.; Netanyahu, Nathan S.; LeMoigne, Jacqueline

    2005-01-01

    Clustering is central to many image processing and remote sensing applications. ISODATA is one of the most popular and widely used clustering methods in geoscience applications, but it can run slowly, particularly with large data sets. We present a more efficient approach to ISODATA clustering, which achieves better running times by storing the points in a kd-tree and through a modification of the way in which the algorithm estimates the dispersion of each cluster. We also present an approximate version of the algorithm which allows the user to further improve the running time, at the expense of lower fidelity in computing the nearest cluster center to each point. We provide both theoretical and empirical justification that our modified approach produces clusterings that are very similar to those produced by the standard ISODATA approach. We also provide empirical studies on both synthetic data and remotely sensed Landsat and MODIS images that show that our approach has significantly lower running times.

  17. A new fast scanning system for the measurement of large angle tracks in nuclear emulsions

    NASA Astrophysics Data System (ADS)

    Alexandrov, A.; Buonaura, A.; Consiglio, L.; D'Ambrosio, N.; De Lellis, G.; Di Crescenzo, A.; Di Marco, N.; Galati, G.; Lauria, A.; Montesi, M. C.; Pupilli, F.; Shchedrina, T.; Tioukov, V.; Vladymyrov, M.

    2015-11-01

    Nuclear emulsions have been widely used in particle physics to identify new particles through the observation of their decays thanks to their unique spatial resolution. Nevertheless, before the advent of automatic scanning systems, the emulsion analysis was very demanding in terms of well trained manpower. Due to this reason, they were gradually replaced by electronic detectors, until the '90s, when automatic microscopes started to be developed in Japan and in Europe. Automatic scanning was essential to conceive large scale emulsion-based neutrino experiments like CHORUS, DONUT and OPERA. Standard scanning systems have been initially designed to recognize tracks within a limited angular acceptance (θ lesssim 30°) where θ is the track angle with respect to a line perpendicular to the emulsion plane. In this paper we describe the implementation of a novel fast automatic scanning system aimed at extending the track recognition to the full angular range and improving the present scanning speed. Indeed, nuclear emulsions do not have any intrinsic limit to detect particle direction. Such improvement opens new perspectives to use nuclear emulsions in several fields in addition to large scale neutrino experiments, like muon radiography, medical applications and dark matter directional detection.

  18. Generic architecture for real-time multisensor fusion tracking algorithm development and evaluation

    NASA Astrophysics Data System (ADS)

    Queeney, Tom; Woods, Edward

    1994-10-01

    Westinghouse has developed and demonstrated a system for the rapid prototyping of Sensor Fusion Tracking (SFT) algorithms. The system provides an object-oriented envelope with three sets of generic software objects to aid in the development and evaluation of SFT algorithms. The first is a generic tracker model that encapsulates the idea of a tracker being a series of SFT algorithms along with the data manipulated by those algorithms and is capable of simultaneously supporting multiple, independent trackers. The second is a set of flexible, easily extensible sensor and target models which allows many types of sensors and targets to be used. Live, recorded and simulated sensors and combinations thereof can be utilized as sources for the trackers. The sensor models also provide an easily extensible interface to the generic tracker model so that all sensors provide input to the SFT algorithms in the same fashion. The third is a highly versatile display and user interface that allows easy access to many of the performance measures for sensors and trackers for easy evaluation and debugging of the SFT algorithms. The system is an object-oriented design programmed in C++. This system with several of the SFT algorithms developed for it has been used with live sensors as a real-time tracking system. This paper outlines the salient features of the sensor fusion architecture and programming environment.

  19. A fast MPP algorithm for Ising spin exchange simulations

    NASA Technical Reports Server (NTRS)

    Sullivan, Francis; Mountain, Raymond D.

    1987-01-01

    A very efficient massively parallel processor (MPP) algorithm is described for performing one important class of Ising spin simulations. Results and physical significance of MPP calculations using the method described is discussed elsewhere. A few comments, however, are made on the problem under study and results so far are reported. Ted Einstein provided guidance in interpreting the initial results and in suggesting calculations to perform.

  20. Fast automatic algorithm for bifurcation detection in vascular CTA scans

    NASA Astrophysics Data System (ADS)

    Brozio, Matthias; Gorbunova, Vladlena; Godenschwager, Christian; Beck, Thomas; Bernhardt, Dominik

    2012-02-01

    Endovascular imaging aims at identifying vessels and their branches. Automatic vessel segmentation and bifurcation detection eases both clinical research and routine work. In this article a state of the art bifurcation detection algorithm is developed and applied on vascular computed tomography angiography (CTA) scans to mark the common iliac artery and its branches, the internal and external iliacs. In contrast to other methods our algorithm does not rely on a complete segmentation of a vessel in the 3D volume, but evaluates the cross-sections of the vessel slice by slice. Candidates for vessels are obtained by thresholding, following by 2D connected component labeling and prefiltering by size and position. The remaining candidates are connected in a squared distanced weighted graph. With Dijkstra algorithm the graph is traversed to get candidates for the arteries. We use another set of features considering length and shape of the paths to determine the best candidate and detect the bifurcation. The method was tested on 119 datasets acquired with different CT scanners and varying protocols. Both easy to evaluate datasets with high resolution and no apparent clinical diseases and difficult ones with low resolution, major calcifications, stents or poor contrast between the vessel and surrounding tissue were included. The presented results are promising, in 75.7% of the cases the bifurcation was labeled correctly, and in 82.7% the common artery and one of its branches were assigned correctly. The computation time was on average 0.49 s +/- 0.28 s, close to human interaction time, which makes the algorithm applicable for time-critical applications.

  1. Control Algorithms for a Shape-shifting Tracked Robotic Vehicle Climbing Obstacles

    DTIC Science & Technology

    2008-12-01

    conduits sur Ie vrai robot afin de verifier la fiabilite et la robust esse des controleurs avec de vrais environnements, capteurs et actuateurs...perception, control and learning algorithms that are widely applicable , fast to compute and adaptive to changing ground conditions. The development of...navigation tasks [11-201. There has been limited application of learning algorithms to shape-shifting platforms for choice of geometry based on

  2. Fast motion prediction algorithm for multiview video coding

    NASA Astrophysics Data System (ADS)

    Abdelazim, Abdelrahman; Zhang, Guang Y.; Mein, Stephen J.; Varley, Martin R.; Ait-Boudaoud, Djamel

    2011-06-01

    Multiview Video Coding (MVC) is an extension to the H.264/MPEG-4 AVC video compression standard developed with joint efforts by MPEG/VCEG to enable efficient encoding of sequences captured simultaneously from multiple cameras using a single video stream. Therefore the design is aimed at exploiting inter-view dependencies in addition to reducing temporal redundancies. However, this further increases the overall encoding complexity In this paper, the high correlation between a macroblock and its enclosed partitions is utilised to estimate motion homogeneity, and based on the result inter-view prediction is selectively enabled or disabled. Moreover, if the MVC is divided into three layers in terms of motion prediction; the first being the full and sub-pixel motion search, the second being the mode selection process and the third being repetition of the first and second for inter-view prediction, the proposed algorithm significantly reduces the complexity in the three layers. To assess the proposed algorithm, a comprehensive set of experiments were conducted. The results show that the proposed algorithm significantly reduces the motion estimation time whilst maintaining similar Rate Distortion performance, when compared to both the H.264/MVC reference software and recently reported work.

  3. Calculation of Computational Complexity for Radix-2 (p) Fast Fourier Transform Algorithms for Medical Signals.

    PubMed

    Amirfattahi, Rassoul

    2013-10-01

    Owing to its simplicity radix-2 is a popular algorithm to implement fast fourier transform. Radix-2(p) algorithms have the same order of computational complexity as higher radices algorithms, but still retain the simplicity of radix-2. By defining a new concept, twiddle factor template, in this paper, we propose a method for exact calculation of multiplicative complexity for radix-2(p) algorithms. The methodology is described for radix-2, radix-2 (2) and radix-2 (3) algorithms. Results show that radix-2 (2) and radix-2 (3) have significantly less computational complexity compared with radix-2. Another interesting result is that while the number of complex multiplications in radix-2 (3) algorithm is slightly more than radix-2 (2), the number of real multiplications for radix-2 (3) is less than radix-2 (2). This is because of the twiddle factors in the form of which need less number of real multiplications and are more frequent in radix-2 (3) algorithm.

  4. Design and implementation of a vision-based hovering and feature tracking algorithm for a quadrotor

    NASA Astrophysics Data System (ADS)

    Lee, Y. H.; Chahl, J. S.

    2016-10-01

    This paper demonstrates an approach to the vision-based control of the unmanned quadrotors for hover and object tracking. The algorithms used the Speed Up Robust Features (SURF) algorithm to detect objects. The pose of the object in the image was then calculated in order to pass the pose information to the flight controller. Finally, the flight controller steered the quadrotor to approach the object based on the calculated pose data. The above processes was run using standard onboard resources found in the 3DR Solo quadrotor in an embedded computing environment. The obtained results showed that the algorithm behaved well during its missions, tracking and hovering, although there were significant latencies due to low CPU performance of the onboard image processing system.

  5. Real Time Optima Tracking Using Harvesting Models of the Genetic Algorithm

    NASA Technical Reports Server (NTRS)

    Baskaran, Subbiah; Noever, D.

    1999-01-01

    Tracking optima in real time propulsion control, particularly for non-stationary optimization problems is a challenging task. Several approaches have been put forward for such a study including the numerical method called the genetic algorithm. In brief, this approach is built upon Darwinian-style competition between numerical alternatives displayed in the form of binary strings, or by analogy to 'pseudogenes'. Breeding of improved solution is an often cited parallel to natural selection in.evolutionary or soft computing. In this report we present our results of applying a novel model of a genetic algorithm for tracking optima in propulsion engineering and in real time control. We specialize the algorithm to mission profiling and planning optimizations, both to select reduced propulsion needs through trajectory planning and to explore time or fuel conservation strategies.

  6. Separated Representations and Fast Algorithms for Materials Science

    DTIC Science & Technology

    2007-10-29

    The public reporting burden for this collection of information is estimated to average 1 hour per response, including the time for reviewing...separable functions, the so-called separated representations. Our approach is different from the Fast U 1 . REPORT DATE (DD-MM-YYYY) 4. TITLE AND SUBTITLE...5f. WORK UNIT NUMBER 5c. PROGRAM ELEMENT NUMBER 5b. GRANT NUMBER 5a. CONTRACT NUMBER W911NF-06- 1 -0254 6D10S7 Form Approved OMB NO. 0704-0188 50966

  7. Fast time-reversible algorithms for molecular dynamics of rigid-body systems

    NASA Astrophysics Data System (ADS)

    Kajima, Yasuhiro; Hiyama, Miyabi; Ogata, Shuji; Kobayashi, Ryo; Tamura, Tomoyuki

    2012-06-01

    In this paper, we present time-reversible simulation algorithms for rigid bodies in the quaternion representation. By advancing a time-reversible algorithm [Y. Kajima, M. Hiyama, S. Ogata, and T. Tamura, J. Phys. Soc. Jpn. 80, 114002 (2011), 10.1143/JPSJ.80.114002] that requires iterations in calculating the angular velocity at each time step, we propose two kinds of iteration-free fast time-reversible algorithms. They are easily implemented in codes. The codes are compared with that of existing algorithms through demonstrative simulation of a nanometer-sized water droplet to find their stability of the total energy and computation speeds.

  8. Fast and accurate image recognition algorithms for fresh produce food safety sensing

    NASA Astrophysics Data System (ADS)

    Yang, Chun-Chieh; Kim, Moon S.; Chao, Kuanglin; Kang, Sukwon; Lefcourt, Alan M.

    2011-06-01

    This research developed and evaluated the multispectral algorithms derived from hyperspectral line-scan fluorescence imaging under violet LED excitation for detection of fecal contamination on Golden Delicious apples. The algorithms utilized the fluorescence intensities at four wavebands, 680 nm, 684 nm, 720 nm, and 780 nm, for computation of simple functions for effective detection of contamination spots created on the apple surfaces using four concentrations of aqueous fecal dilutions. The algorithms detected more than 99% of the fecal spots. The effective detection of feces showed that a simple multispectral fluorescence imaging algorithm based on violet LED excitation may be appropriate to detect fecal contamination on fast-speed apple processing lines.

  9. Integration of an On-Axis General Sun-Tracking Formula in the Algorithm of an Open-Loop Sun-Tracking System

    PubMed Central

    Chong, Kok-Keong; Wong, Chee-Woon; Siaw, Fei-Lu; Yew, Tiong-Keat; Ng, See-Seng; Liang, Meng-Suan; Lim, Yun-Seng; Lau, Sing-Liong

    2009-01-01

    A novel on-axis general sun-tracking formula has been integrated in the algorithm of an open-loop sun-tracking system in order to track the sun accurately and cost effectively. Sun-tracking errors due to installation defects of the 25 m2 prototype solar concentrator have been analyzed from recorded solar images with the use of a CCD camera. With the recorded data, misaligned angles from ideal azimuth-elevation axes have been determined and corrected by a straightforward changing of the parameters' values in the general formula of the tracking algorithm to improve the tracking accuracy to 2.99 mrad, which falls below the encoder resolution limit of 4.13 mrad. PMID:22408483

  10. A constrained tracking algorithm to optimize plug patterns in multiple isocenter Gamma Knife radiosurgery planning

    SciTech Connect

    Li Kaile; Ma Lijun

    2005-10-15

    We developed a source blocking optimization algorithm for Gamma Knife radiosurgery, which is based on tracking individual source contributions to arbitrarily shaped target and critical structure volumes. A scalar objective function and a direct search algorithm were used to produce near real-time calculation results. The algorithm allows the user to set and vary the total number of plugs for each shot to limit the total beam-on time. We implemented and tested the algorithm for several multiple-isocenter Gamma Knife cases. It was found that the use of limited number of plugs significantly lowered the integral dose to the critical structures such as an optical chiasm in pituitary adenoma cases. The main effect of the source blocking is the faster dose falloff in the junction area between the target and the critical structure. In summary, we demonstrated a useful source-plugging algorithm for improving complex multi-isocenter Gamma Knife treatment planning cases.

  11. Investigation of Control Algorithms for Tracked Vehicle Mobility Load Emulation for a Combat Hybrid Electric Power System

    DTIC Science & Technology

    2009-07-30

    Investigation of Control Algorithms for Tracked Vehicle Mobility Load Emulation for a Combat Hybrid Electric Power System Jarrett Goodell and...TITLE AND SUBTITLE Investigation of Control Algorithms for Tracked Vehicle Mobility Load Emulation for a Combat Hybrid Electric Power System 5a...for ~ 22 ton tracked vehicle • Tested and Developed: – Motors, Generators, Batteries, Inverters, DC-DC Converters , Thermal Management, Pulse Power

  12. Fast Huffman encoding algorithms in MPEG-4 advanced audio coding

    NASA Astrophysics Data System (ADS)

    Brzuchalski, Grzegorz

    2014-11-01

    This paper addresses the optimisation problem of Huffman encoding in MPEG-4 Advanced Audio Coding stan- dard. At first, the Huffman encoding problem and the need of encoding two side info parameters scale factor and Huffman codebook are presented. Next, Two Loop Search, Maximum Noise Mask Ratio and Trellis Based algorithms of bit allocation are briefly described. Further, Huffman encoding optimisation are shown. New methods try to check and change scale factor bands as little as possible to estimate bitrate cost or its change. Finally, the complexity of old and new methods is calculated, compared and measured time of encoding is given.

  13. Fast algorithm for calculating optical binary amplitude filters

    NASA Astrophysics Data System (ADS)

    Knopp, Jerome; Matalgah, Mustafa M.

    1995-08-01

    A new geometric viewpoint is presented for optimizing a binary amplitude filter based on finding an ordered set of phasors, the uncoiled phasor set (UPS), from the filter object's discrete Fourier transform that determines a convex polygon. The maximum distance across the polygon determines the value of the correlation peak and the set of frequencies that the optimal filter should pass. Algorithms are presented for finding the UPS and the maximum distance across the polygon that are competititve with optimization approaches that use the binning (Farn and Goodman). The new viewpoint provides a simple way to establish a bound on binning error.

  14. Single-Cell Tracking with PET using a Novel Trajectory Reconstruction Algorithm

    PubMed Central

    Lee, Keum Sil; Kim, Tae Jin

    2015-01-01

    Virtually all biomedical applications of positron emission tomography (PET) use images to represent the distribution of a radiotracer. However, PET is increasingly used in cell tracking applications, for which the “imaging” paradigm may not be optimal. Here we investigate an alternative approach, which consists in reconstructing the time-varying position of individual radiolabeled cells directly from PET measurements. As a proof of concept, we formulate a new algorithm for reconstructing the trajectory of one single moving cell directly from list-mode PET data. We model the trajectory as a 3D B-spline function of the temporal variable and use non-linear optimization to minimize the mean-square distance between the trajectory and the recorded list-mode coincidence events. Using Monte Carlo simulations (GATE), we show that this new algorithm can track a single source moving within a small-animal PET system with <3 mm accuracy provided that the activity of the cell [Bq] is greater than four times its velocity [mm/s]. The algorithm outperforms conventional ML-EM as well as the “minimum distance” method used for positron emission particle tracking (PEPT). The new method was also successfully validated using experimentally acquired PET data. In conclusion, we demonstrated the feasibility of a new method for tracking a single moving cell directly from PET list-mode data, at the whole-body level, for physiologically relevant activities and velocities. PMID:25423651

  15. Fast Quantum Algorithm for Predicting Descriptive Statistics of Stochastic Processes

    NASA Technical Reports Server (NTRS)

    Williams Colin P.

    1999-01-01

    Stochastic processes are used as a modeling tool in several sub-fields of physics, biology, and finance. Analytic understanding of the long term behavior of such processes is only tractable for very simple types of stochastic processes such as Markovian processes. However, in real world applications more complex stochastic processes often arise. In physics, the complicating factor might be nonlinearities; in biology it might be memory effects; and in finance is might be the non-random intentional behavior of participants in a market. In the absence of analytic insight, one is forced to understand these more complex stochastic processes via numerical simulation techniques. In this paper we present a quantum algorithm for performing such simulations. In particular, we show how a quantum algorithm can predict arbitrary descriptive statistics (moments) of N-step stochastic processes in just O(square root of N) time. That is, the quantum complexity is the square root of the classical complexity for performing such simulations. This is a significant speedup in comparison to the current state of the art.

  16. A fast algorithm for the simulation of arterial pulse waves

    NASA Astrophysics Data System (ADS)

    Du, Tao; Hu, Dan; Cai, David

    2016-06-01

    One-dimensional models have been widely used in studies of the propagation of blood pulse waves in large arterial trees. Under a periodic driving of the heartbeat, traditional numerical methods, such as the Lax-Wendroff method, are employed to obtain asymptotic periodic solutions at large times. However, these methods are severely constrained by the CFL condition due to large pulse wave speed. In this work, we develop a new numerical algorithm to overcome this constraint. First, we reformulate the model system of pulse wave propagation using a set of Riemann variables and derive a new form of boundary conditions at the inlet, the outlets, and the bifurcation points of the arterial tree. The new form of the boundary conditions enables us to design a convergent iterative method to enforce the boundary conditions. Then, after exchanging the spatial and temporal coordinates of the model system, we apply the Lax-Wendroff method in the exchanged coordinate system, which turns the large pulse wave speed from a liability to a benefit, to solve the wave equation in each artery of the model arterial system. Our numerical studies show that our new algorithm is stable and can perform ∼15 times faster than the traditional implementation of the Lax-Wendroff method under the requirement that the relative numerical error of blood pressure be smaller than one percent, which is much smaller than the modeling error.

  17. Fast algorithms for glassy materials: methods and explorations

    NASA Astrophysics Data System (ADS)

    Middleton, A. Alan

    2014-03-01

    Glassy materials with frozen disorder, including random magnets such as spin glasses and interfaces in disordered materials, exhibit striking non-equilibrium behavior such as the ability to store a history of external parameters (memory). Precisely due to their glassy nature, direct simulation of models of these materials is very slow. In some fortunate cases, however, algorithms exist that exactly compute thermodynamic quantities. Such cases include spin glasses in two dimensions and interfaces and random field magnets in arbitrary dimensions at zero temperature. Using algorithms built using ideas developed by computer scientists and mathematicians, one can even directly sample equilibrium configurations in very large systems, as if one picked the configurations out of a ``hat'' of all configurations weighted by their Boltzmann factors. This talk will provide some of the background for these methods and discuss the connections between physics and computer science, as used by a number of groups. Recent applications of these methods to investigating phase transitions in glassy materials and to answering qualitative questions about the free energy landscape and memory effects will be discussed. This work was supported in part by NSF grant DMR-1006731. Creighton Thomas and David Huse also contributed to much of the work to be presented.

  18. Fast-SNP: a fast matrix pre-processing algorithm for efficient loopless flux optimization of metabolic models

    PubMed Central

    Saa, Pedro A.; Nielsen, Lars K.

    2016-01-01

    Motivation: Computation of steady-state flux solutions in large metabolic models is routinely performed using flux balance analysis based on a simple LP (Linear Programming) formulation. A minimal requirement for thermodynamic feasibility of the flux solution is the absence of internal loops, which are enforced using ‘loopless constraints’. The resulting loopless flux problem is a substantially harder MILP (Mixed Integer Linear Programming) problem, which is computationally expensive for large metabolic models. Results: We developed a pre-processing algorithm that significantly reduces the size of the original loopless problem into an easier and equivalent MILP problem. The pre-processing step employs a fast matrix sparsification algorithm—Fast- sparse null-space pursuit (SNP)—inspired by recent results on SNP. By finding a reduced feasible ‘loop-law’ matrix subject to known directionalities, Fast-SNP considerably improves the computational efficiency in several metabolic models running different loopless optimization problems. Furthermore, analysis of the topology encoded in the reduced loop matrix enabled identification of key directional constraints for the potential permanent elimination of infeasible loops in the underlying model. Overall, Fast-SNP is an effective and simple algorithm for efficient formulation of loop-law constraints, making loopless flux optimization feasible and numerically tractable at large scale. Availability and Implementation: Source code for MATLAB including examples is freely available for download at http://www.aibn.uq.edu.au/cssb-resources under Software. Optimization uses Gurobi, CPLEX or GLPK (the latter is included with the algorithm). Contact: lars.nielsen@uq.edu.au Supplementary information: Supplementary data are available at Bioinformatics online. PMID:27559155

  19. A fast double template convolution isocenter evaluation algorithm with subpixel accuracy

    SciTech Connect

    Winey, Brian; Sharp, Greg; Bussiere, Marc

    2011-01-15

    Purpose: To design a fast Winston Lutz (fWL) algorithm for accurate analysis of radiation isocenter from images without edge detection or center of mass calculations. Methods: An algorithm has been developed to implement the Winston Lutz test for mechanical/radiation isocenter agreement using an electronic portal imaging device (EPID). The algorithm detects the position of the radiation shadow of a tungsten ball within a stereotactic cone. The fWL algorithm employs a double convolution to independently find the position of the sphere and cone centers. Subpixel estimation is used to achieve high accuracy. Results of the algorithm were compared to (1) a human observer with template guidance and (2) an edge detection/center of mass (edCOM) algorithm. Testing was performed with high resolution (0.05mm/px, film) and low resolution (0.78mm/px, EPID) image sets. Results: Sphere and cone center relative positions were calculated with the fWL algorithm for high resolution test images with an accuracy of 0.002{+-}0.061 mm compared to 0.042{+-}0.294 mm for the human observer, and 0.003{+-}0.038 mm for the edCOM algorithm. The fWL algorithm required 0.01 s per image compared to 5 s for the edCOM algorithm and 20 s for the human observer. For lower resolution images the fWL algorithm localized the centers with an accuracy of 0.083{+-}0.12 mm compared to 0.03{+-}0.5514 mm for the edCOM algorithm. Conclusions: A fast (subsecond) subpixel algorithm has been developed that can accurately determine the center locations of the ball and cone in Winston Lutz test images without edge detection or COM calculations.

  20. Sunspots and Coronal Bright Points Tracking using a Hybrid Algorithm of PSO and Active Contour Model

    NASA Astrophysics Data System (ADS)

    Dorotovic, I.; Shahamatnia, E.; Lorenc, M.; Rybansky, M.; Ribeiro, R. A.; Fonseca, J. M.

    2014-02-01

    In the last decades there has been a steady increase of high-resolution data, from ground-based and space-borne solar instruments, and also of solar data volume. These huge image archives require efficient automatic image processing software tools capable of detecting and tracking various features in the solar atmosphere. Results of application of such tools are essential for studies of solar activity evolution, climate change understanding and space weather prediction. The follow up of interplanetary and near-Earth phenomena requires, among others, automatic tracking algorithms that can determine where a feature is located, on successive images taken along the period of observation. Full-disc solar images, obtained both with the ground-based solar telescopes and the instruments onboard the satellites, provide essential observational material for solar physicists and space weather researchers for better understanding the Sun, studying the evolution of various features in the solar atmosphere, and also investigating solar differential rotation by tracking such features along time. Here we demonstrate and discuss the suitability of applying a hybrid Particle Swarm Optimization (PSO) algorithm and Active Contour model for tracking and determining the differential rotation of sunspots and coronal bright points (CBPs) on a set of selected solar images. The results obtained confirm that the proposed approach constitutes a promising tool for investigating the evolution of solar activity and also for automating tracking features on massive solar image archives.

  1. Automatic recognition of harmonic bird sounds using a frequency track extraction algorithm.

    PubMed

    Heller, Jason R; Pinezich, John D

    2008-09-01

    This paper demonstrates automatic recognition of vocalizations of four common bird species (herring gull [Larus argentatus], blue jay [Cyanocitta cristata], Canada goose [Branta canadensis], and American crow [Corvus brachyrhynchos]) using an algorithm that extracts frequency track sets using track properties of importance and harmonic correlation. The main result is that a complex harmonic vocalization is rendered into a set of related tracks that is easily applied to statistical models of the actual bird vocalizations. For each vocalization type, a statistical model of the vocalization was created by transforming the training set frequency tracks into feature vectors. The extraction algorithm extracts sets of frequency tracks from test recordings that closely approximate harmonic sounds in the file being processed. Each extracted set in its final form is then compared with the statistical models generated during the training phase using Mahalanobis distance functions. If it matches one of the models closely, the recognizer declares the set an occurrence of the corresponding vocalization. The method was evaluated against a test set containing vocalizations of both the 4 target species and 16 additional species as well as background noise containing planes, cars, and various natural sounds.

  2. Fast-Track Surgery in Gynaecology and Gynaecologic Oncology: A Review of a Rolling Clinical Audit

    PubMed Central

    Carter, Jonathan

    2012-01-01

    Clinical audit is the process by which clinicians are able to demonstrate to themselves, their patients, hospital administrators, and healthcare financial providers the outcome and safety of their clinical practice. It is a process by which the public can be assured of safety and outcomes. A fast-track surgery program was initiated in January 2008, and this paper represents a rolling clinical audit of the outcomes of that program until the end of June 2012. Three hundred and eighty-nine patients underwent fast track surgical management after having a laparotomy for suspected or confirmed gynaecological cancer. There were no exclusions and the data presented represents the practice and outcomes of all patients referred to a single gynaecological oncologist. The majority of patients were deemed to have complex surgical procedures performed usually through a vertical midline incision. One third of patients had a nonzero performance status, median weight was 68 kilograms, and median BMI was 26.5 with 31% being classified as obese. Median operating time was 2.25 hours, and the median estimated blood loss was 175 mL. Overall the median length of stay (LOS) was 3 days with 95% of patients tolerating early oral feeding. Four percent of patients required readmission, and 0.5% were required to return to the operating room. Whilst the wound infection rate was 2.6%, there were no ureteric, bowel or neurovascular injuries. Overall there were 2 bladder injuries (0.5%), and the incidence of venous thromboembolism was 1%. Subset analysis was also undertaken. Whilst a number of variables were associated with reduced LOS, on multivariate analysis, benign pathology, shorter operating time, and the ability to tolerate early oral feeding were found to be significant. The data and experience presented is the largest and most extensive reported in the literature relating to fast-track surgery in gynaecology and gynaecologic oncology. The public can be reassured of the safety and

  3. Fast and parallel spectral transform algorithms for global shallow water models. Doctoral thesis

    SciTech Connect

    Jakob, R.

    1993-01-01

    The dissertation examines spectral transform algorithms for the solution of the shallow water equations on the sphere and studies their implementation and performance on shared memory vector multiprocessors. Beginning with the standard spectral transform algorithm in vorticity divergence form and its implementation in the Fortran based parallel programming language Force, two modifications are researched. First, the transforms and matrices associated with the meridional derivatives of the associated Legendre functions are replaced by corresponding operations with the spherical harmonic coefficients. Second, based on the fast Fourier transform and the fast multipole method, a lower complexity algorithm is derived that uses fast transformations between Legendre and interior Fourier nodes, fast surface spherical truncation and a fast spherical Helmholz solver. Because the global shallow water equations are similar to the horizontal dynamical component of general circulation models, the results can be applied to spectral transform numerical weather prediction and climate models. In general, the derived algorithms may speed up the solution of time dependent partial differential equations in spherical geometry.

  4. Fast algorithms for numerical, conservative, and entropy approximations of the Fokker-Planck-Landau equation

    SciTech Connect

    Buet, C.; Cordier; Degond, P.; Lemou, M.

    1997-05-15

    We present fast numerical algorithms to solve the nonlinear Fokker-Planck-Landau equation in 3D velocity space. The discretization of the collision operator preserves the properties required by the physical nature of the Fokker-Planck-Landau equation, such as the conservation of mass, momentum, and energy, the decay of the entropy, and the fact that the steady states are Maxwellians. At the end of this paper, we give numerical results illustrating the efficiency of these fast algorithms in terms of accuracy and CPU time. 20 refs., 7 figs.

  5. Prediction of engine performance and wall erosion due to film cooling for the 'fast track' ablative thrust chamber

    NASA Technical Reports Server (NTRS)

    Trinh, Huu P.

    1994-01-01

    Efforts have been made at the Propulsion Laboratory (MSFC) to design and develop new liquid rocket engines for small-class launch vehicles. Emphasis of the efforts is to reduce the engine development time with the use of conventional designs while meeting engine reliability criteria. Consequently, the engine cost should be reduced. A demonstrative ablative thrust chamber, called 'fast-track', has been built. To support the design of the 'fast-track' thrust chamber, predictions of the wall temperature and ablation erosion rate of the 'fast-track' thrust chamber have been performed using the computational fluid dynamics program REFLEQS (Reactive Flow Equation Solver). The analysis is intended to assess the amount of fuel to be used for film cooling so that the erosion rate of the chamber ablation does not exceed its allowable limit. In addition, the thrust chamber performance loss due to an increase of the film cooling is examined.

  6. Fast Parabola Detection Using Estimation of Distribution Algorithms

    PubMed Central

    Sierra-Hernandez, Juan Manuel; Avila-Garcia, Maria Susana; Rojas-Laguna, Roberto

    2017-01-01

    This paper presents a new method based on Estimation of Distribution Algorithms (EDAs) to detect parabolic shapes in synthetic and medical images. The method computes a virtual parabola using three random boundary pixels to calculate the constant values of the generic parabola equation. The resulting parabola is evaluated by matching it with the parabolic shape in the input image by using the Hadamard product as fitness function. This proposed method is evaluated in terms of computational time and compared with two implementations of the generalized Hough transform and RANSAC method for parabola detection. Experimental results show that the proposed method outperforms the comparative methods in terms of execution time about 93.61% on synthetic images and 89% on retinal fundus and human plantar arch images. In addition, experimental results have also shown that the proposed method can be highly suitable for different medical applications. PMID:28321264

  7. Fast Parabola Detection Using Estimation of Distribution Algorithms.

    PubMed

    Guerrero-Turrubiates, Jose de Jesus; Cruz-Aceves, Ivan; Ledesma, Sergio; Sierra-Hernandez, Juan Manuel; Velasco, Jonas; Avina-Cervantes, Juan Gabriel; Avila-Garcia, Maria Susana; Rostro-Gonzalez, Horacio; Rojas-Laguna, Roberto

    2017-01-01

    This paper presents a new method based on Estimation of Distribution Algorithms (EDAs) to detect parabolic shapes in synthetic and medical images. The method computes a virtual parabola using three random boundary pixels to calculate the constant values of the generic parabola equation. The resulting parabola is evaluated by matching it with the parabolic shape in the input image by using the Hadamard product as fitness function. This proposed method is evaluated in terms of computational time and compared with two implementations of the generalized Hough transform and RANSAC method for parabola detection. Experimental results show that the proposed method outperforms the comparative methods in terms of execution time about 93.61% on synthetic images and 89% on retinal fundus and human plantar arch images. In addition, experimental results have also shown that the proposed method can be highly suitable for different medical applications.

  8. Ultra-fast fluence optimization for beam angle selection algorithms

    NASA Astrophysics Data System (ADS)

    Bangert, M.; Ziegenhein, P.; Oelfke, U.

    2014-03-01

    Beam angle selection (BAS) including fluence optimization (FO) is among the most extensive computational tasks in radiotherapy. Precomputed dose influence data (DID) of all considered beam orientations (up to 100 GB for complex cases) has to be handled in the main memory and repeated FOs are required for different beam ensembles. In this paper, the authors describe concepts accelerating FO for BAS algorithms using off-the-shelf multiprocessor workstations. The FO runtime is not dominated by the arithmetic load of the CPUs but by the transportation of DID from the RAM to the CPUs. On multiprocessor workstations, however, the speed of data transportation from the main memory to the CPUs is non-uniform across the RAM; every CPU has a dedicated memory location (node) with minimum access time. We apply a thread node binding strategy to ensure that CPUs only access DID from their preferred node. Ideal load balancing for arbitrary beam ensembles is guaranteed by distributing the DID of every candidate beam equally to all nodes. Furthermore we use a custom sorting scheme of the DID to minimize the overall data transportation. The framework is implemented on an AMD Opteron workstation. One FO iteration comprising dose, objective function, and gradient calculation takes between 0.010 s (9 beams, skull, 0.23 GB DID) and 0.070 s (9 beams, abdomen, 1.50 GB DID). Our overall FO time is < 1 s for small cases, larger cases take ~ 4 s. BAS runs including FOs for 1000 different beam ensembles take ~ 15-70 min, depending on the treatment site. This enables an efficient clinical evaluation of different BAS algorithms.

  9. The small-voxel tracking algorithm for simulating chemical reactions among diffusing molecules

    NASA Astrophysics Data System (ADS)

    Gillespie, Daniel T.; Seitaridou, Effrosyni; Gillespie, Carol A.

    2014-12-01

    Simulating the evolution of a chemically reacting system using the bimolecular propensity function, as is done by the stochastic simulation algorithm and its reaction-diffusion extension, entails making statistically inspired guesses as to where the reactant molecules are at any given time. Those guesses will be physically justified if the system is dilute and well-mixed in the reactant molecules. Otherwise, an accurate simulation will require the extra effort and expense of keeping track of the positions of the reactant molecules as the system evolves. One molecule-tracking algorithm that pays careful attention to the physics of molecular diffusion is the enhanced Green's function reaction dynamics (eGFRD) of Takahashi, Tănase-Nicola, and ten Wolde [Proc. Natl. Acad. Sci. U.S.A. 107, 2473 (2010)]. We introduce here a molecule-tracking algorithm that has the same theoretical underpinnings and strategic aims as eGFRD, but a different implementation procedure. Called the small-voxel tracking algorithm (SVTA), it combines the well known voxel-hopping method for simulating molecular diffusion with a novel procedure for rectifying the unphysical predictions of the diffusion equation on the small spatiotemporal scale of molecular collisions. Indications are that the SVTA might be more computationally efficient than eGFRD for the problematic class of non-dilute systems. A widely applicable, user-friendly software implementation of the SVTA has yet to be developed, but we exhibit some simple examples which show that the algorithm is computationally feasible and gives plausible results.

  10. Fast estimation of defect profiles from the magnetic flux leakage signal based on a multi-power affine projection algorithm.

    PubMed

    Han, Wenhua; Shen, Xiaohui; Xu, Jun; Wang, Ping; Tian, Guiyun; Wu, Zhengyang

    2014-09-04

    Magnetic flux leakage (MFL) inspection is one of the most important and sensitive nondestructive testing approaches. For online MFL inspection of a long-range railway track or oil pipeline, a fast and effective defect profile estimating method based on a multi-power affine projection algorithm (MAPA) is proposed, where the depth of a sampling point is related with not only the MFL signals before it, but also the ones after it, and all of the sampling points related to one point appear as serials or multi-power. Defect profile estimation has two steps: regulating a weight vector in an MAPA filter and estimating a defect profile with the MAPA filter. Both simulation and experimental data are used to test the performance of the proposed method. The results demonstrate that the proposed method exhibits high speed while maintaining the estimated profiles clearly close to the desired ones in a noisy environment, thereby meeting the demand of accurate online inspection.

  11. Fast Estimation of Defect Profiles from the Magnetic Flux Leakage Signal Based on a Multi-Power Affine Projection Algorithm

    PubMed Central

    Han, Wenhua; Shen, Xiaohui; Xu, Jun; Wang, Ping; Tian, Guiyun; Wu, Zhengyang

    2014-01-01

    Magnetic flux leakage (MFL) inspection is one of the most important and sensitive nondestructive testing approaches. For online MFL inspection of a long-range railway track or oil pipeline, a fast and effective defect profile estimating method based on a multi-power affine projection algorithm (MAPA) is proposed, where the depth of a sampling point is related with not only the MFL signals before it, but also the ones after it, and all of the sampling points related to one point appear as serials or multi-power. Defect profile estimation has two steps: regulating a weight vector in an MAPA filter and estimating a defect profile with the MAPA filter. Both simulation and experimental data are used to test the performance of the proposed method. The results demonstrate that the proposed method exhibits high speed while maintaining the estimated profiles clearly close to the desired ones in a noisy environment, thereby meeting the demand of accurate online inspection. PMID:25192314

  12. SIML: a fast SIMD algorithm for calculating LINGO chemical similarities on GPUs and CPUs.

    PubMed

    Haque, Imran S; Pande, Vijay S; Walters, W Patrick

    2010-04-26

    LINGOs are a holographic measure of chemical similarity based on text comparison of SMILES strings. We present a new algorithm for calculating LINGO similarities amenable to parallelization on SIMD architectures (such as GPUs and vector units of modern CPUs). We show that it is nearly 3x as fast as existing algorithms on a CPU, and over 80x faster than existing methods when run on a GPU.

  13. A preliminary report on the development of MATLAB tensor classes for fast algorithm prototyping.

    SciTech Connect

    Bader, Brett William; Kolda, Tamara Gibson

    2004-07-01

    We describe three MATLAB classes for manipulating tensors in order to allow fast algorithm prototyping. A tensor is a multidimensional or N-way array. We present a tensor class for manipulating tensors which allows for tensor multiplication and 'matricization.' We have further added two classes for representing tensors in decomposed format: cp{_}tensor and tucker{_}tensor. We demonstrate the use of these classes by implementing several algorithms that have appeared in the literature.

  14. On fading probability density functions of fast-tracked and untracked free-space optical communication channels

    NASA Astrophysics Data System (ADS)

    Zhao, Zhijun; Liao, Rui

    2011-03-01

    Free-space optical (FSO) communication systems suffer from average power loss and instantaneous power fading due to the atmospheric turbulence. The channel fading probability density function (pdf) is of critical importance for FSO communication system design and evaluation. The performance and reliability of FSO communication systems can be greatly enhanced if fast-tacking devices are employed at the transmitter in order to compensate laser beam wander at the receiver aperture. The fast-tracking method is especially effective when communication distance is long. This paper studies the fading probability density functions of both fast-tracked and untracked FSO communication channels. Large-scale wave-optics simulations are conducted for both tracked and untracked lasers. In the simulations, the Kolmogorov spectrum is adopted, and it is assumed that the outer scale is infinitely large and the inner scale is negligibly small. The fading pdfs of both fast-tracked and untracked FSO channels are obtained from the simulations. Results show that the fast-tracked channel fading can be accurately modeled as gamma-distributed if receiver aperture size is smaller than the coherence radius. An analytical method is given for calculating the untracked fading pdfs of both point-like and finite-size receiver apertures from the fast-tracked fading pdf. For point-like apertures, the analytical method gives pdfs close to the well-known gamma-gamma pdfs if off-axis effects are omitted in the formulation. When off-axis effects are taken into consideration, the untracked pdfs obtained using the analytical method fit the simulation pdfs better than gamma-gamma distributions for point-like apertures, and closely fit the simulation pdfs for finite-size apertures where gamma-gamma pdfs deviate from those of the simulations significantly.

  15. A Fast Elitism Gaussian Estimation of Distribution Algorithm and Application for PID Optimization

    PubMed Central

    Xu, Qingyang; Zhang, Chengjin; Zhang, Li

    2014-01-01

    Estimation of distribution algorithm (EDA) is an intelligent optimization algorithm based on the probability statistics theory. A fast elitism Gaussian estimation of distribution algorithm (FEGEDA) is proposed in this paper. The Gaussian probability model is used to model the solution distribution. The parameters of Gaussian come from the statistical information of the best individuals by fast learning rule. A fast learning rule is used to enhance the efficiency of the algorithm, and an elitism strategy is used to maintain the convergent performance. The performances of the algorithm are examined based upon several benchmarks. In the simulations, a one-dimensional benchmark is used to visualize the optimization process and probability model learning process during the evolution, and several two-dimensional and higher dimensional benchmarks are used to testify the performance of FEGEDA. The experimental results indicate the capability of FEGEDA, especially in the higher dimensional problems, and the FEGEDA exhibits a better performance than some other algorithms and EDAs. Finally, FEGEDA is used in PID controller optimization of PMSM and compared with the classical-PID and GA. PMID:24892059

  16. Electric eels use high-voltage to track fast-moving prey

    PubMed Central

    Catania, Kenneth C.

    2015-01-01

    Electric eels (Electrophorus electricus) are legendary for their ability to incapacitate fish, humans, and horses with hundreds of volts of electricity. The function of this output as a weapon has been obvious for centuries but its potential role for electroreception has been overlooked. Here it is shown that electric eels use high-voltage simultaneously as a weapon and for precise and rapid electrolocation of fast-moving prey and conductors. Their speed, accuracy, and high-frequency pulse rate are reminiscent of bats using a ‘terminal feeding buzz' to track insects. Eel's exhibit ‘sensory conflict' when mechanosensory and electrosensory cues are separated, striking first toward mechanosensory cues and later toward conductors. Strikes initiated in the absence of conductors are aborted. In addition to providing new insights into the evolution of strongly electric fish and showing electric eels to be far more sophisticated than previously described, these findings reveal a trait with markedly dichotomous functions. PMID:26485580

  17. Health Preemption Behind Closed Doors: Trade Agreements and Fast-Track Authority

    PubMed Central

    Crosbie, Eric; Gonzalez, Mariaelena

    2014-01-01

    Noncommunicable diseases result from consuming unhealthy products, including tobacco, which are promoted by transnational corporations. The tobacco industry uses preemption to block or reverse tobacco control policies. Preemption removes authority from jurisdictions where tobacco companies’ influence is weak and transfers it to jurisdictions where they have an advantage. International trade agreements relocate decisions about tobacco control policy to venues where there is little opportunity for public scrutiny, participation, and debate. Tobacco companies are using these agreements to preempt domestic authority over tobacco policy. Other transnational corporations that profit by promoting unhealthy foods could do the same. “Fast-track authority,” in which Congress cedes ongoing oversight authority to the President, further distances the public from the debate. With international agreements binding governments to prioritize trade over health, transparency and public oversight of the trade negotiation process is necessary to safeguard public health interests. PMID:25033124

  18. Health preemption behind closed doors: trade agreements and fast-track authority.

    PubMed

    Crosbie, Eric; Gonzalez, Mariaelena; Glantz, Stanton A

    2014-09-01

    Noncommunicable diseases result from consuming unhealthy products, including tobacco, which are promoted by transnational corporations. The tobacco industry uses preemption to block or reverse tobacco control policies. Preemption removes authority from jurisdictions where tobacco companies' influence is weak and transfers it to jurisdictions where they have an advantage. International trade agreements relocate decisions about tobacco control policy to venues where there is little opportunity for public scrutiny, participation, and debate. Tobacco companies are using these agreements to preempt domestic authority over tobacco policy. Other transnational corporations that profit by promoting unhealthy foods could do the same. "Fast-track authority," in which Congress cedes ongoing oversight authority to the President, further distances the public from the debate. With international agreements binding governments to prioritize trade over health, transparency and public oversight of the trade negotiation process is necessary to safeguard public health interests.

  19. Tracking Down a Fast Instability in the PEP-II LER

    SciTech Connect

    Wienands, U.; Akre, R.; Curry, S.; DeBarger, S.; Decker, F.J.; Ecklund, S.; Fisher, A.S.; Heifets, S.A.; Krasnykh, A.; Kulikov, A.; Novokhatski, A.; Seeman, J.; Sullivan, M.K.; Teytelman, D.; Van Winkle, D.; Yocky, G.; /SLAC

    2007-05-18

    During Run 5, the beam in the PEP-II Low Energy Ring (LER) became affected by a predominantly vertical instability with very fast growth rate of 10...60/ms and varying threshold. The coherent amplitude of the oscillation was limited to approx. 1 mm peak and would damp down over a few tens of turns, however, beam loss set in even as the amplitude signal damped, causing a beam abort. This led to the conclusion that the bunches were actually blowing up. The appearance of a 2{nu}{sub S} line in the spectrum suggested a possible head-tail nature of the instability, although chromaticity was not effective in changing the threshold. The crucial hints in tracking down the cause turned out to be vacuum activity near the rf cavities and observance of signals on the cavity probes of certain rf cavities.

  20. The Effects of the Fast Track Preventive Intervention on the Development of Conduct Disorder Across Childhood

    PubMed Central

    2013-01-01

    The impact of the Fast Track intervention on externalizing disorders across childhood was examined. Eight hundred-ninety-one early-starting children (69% male; 51% African American) were randomly assigned by matched sets of schools to intervention or control conditions. The 10-year intervention addressed parent behavior-management, child social cognitive skills, reading, home visiting, mentoring, and classroom curricula. Outcomes included psychiatric diagnoses after grades 3, 6, 9, and 12 for conduct disorder, oppositional defiant disorder, attention deficit hyperactivity disorder, and any externalizing disorder. Significant interaction effects between intervention and initial risk level indicated that intervention prevented the lifetime prevalence of all diagnoses, but only among those at highest initial risk, suggesting that targeted intervention can prevent externalizing disorders to promote the raising of healthy children. PMID:21291445

  1. The Vanderbilt University fast track to IAIMS: transition from planning to implementation.

    PubMed Central

    Stead, W W; Borden, R; Bourne, J; Giuse, D; Giuse, N; Harris, T R; Miller, R A; Olsen, A J

    1996-01-01

    Vanderbilt University Medical Center is implementing an Integrated Advanced Information Management System (IAIMS) using a fast-track approach. The elapsed time between start-up and completion of implementation will be 7.5 years. The Start-Up and Planning phases of the project are complete. The Implementation phase asks one question: How does an organization create an environment that redirects and coordinates a variety of individual activities so that they come together to provide an IAIMS? Four answers to this question are being tested. First, design resources to be "scalable"--i.e., capable of supporting enterprise-wide use. Second, provide information technology planning activities as ongoing core functions that direct local efforts. Third, design core infrastructure resources to be both reusable and expandable at the local level. Fourth, use milestones to measure progress toward selected endpoints to permit early refinement of plans and strategies. PMID:8880678

  2. Locational Sensitivity Investigation on PV Hosting Capacity and Fast Track PV Screening

    SciTech Connect

    Ding, Fei; Mather, Barry; Ainsworth, Nathan; Gotseff, Peter; Baker, Kyri

    2016-05-05

    A 15% PV penetration threshold is commonly used by utilities to define photovoltaic (PV) screening methods where PV penetration is defined as the ratio of total solar PV capacity on a line section to peak load. However, this method doesn't take into account PV locational impact or feeder characteristics that could strongly change the feeder's capability to host PVs. This paper investigates the impact of PV location and phase connection type on PV hosting capacity, and then proposes a fast-track PV screening approach that leverages various PV hosting capacity metric responding to different PV locations and types. The proposed study could help utilities to evaluate PV interconnection requests and also help increase the PV hosting capacity of distribution feeders without adverse impacts on system voltages.

  3. Fast cine-magnetic resonance imaging point tracking for prostate cancer radiation therapy planning

    NASA Astrophysics Data System (ADS)

    Dowling, J.; Dang, K.; Fox, Chris D.; Chandra, S.; Gill, Suki; Kron, T.; Pham, D.; Foroudi, F.

    2014-03-01

    The analysis of intra-fraction organ motion is important for improving the precision of radiation therapy treatment delivery. One method to quantify this motion is for one or more observers to manually identify anatomic points of interest (POIs) on each slice of a cine-MRI sequence. However this is labour intensive and inter- and intra- observer variation can introduce uncertainty. In this paper a fast method for non-rigid registration based point tracking in cine-MRI sagittal and coronal series is described which identifies POIs in 0.98 seconds per sagittal slice and 1.35 seconds per coronal slice. The manual and automatic points were highly correlated (r>0.99, p<0.001) for all organs and the difference generally less than 1mm. For prostate planning peristalsis and rectal gas can result in unpredictable out of plane motion, suggesting the results may require manual verification.

  4. Fast algorithm for calculation of the moving tsunami wave height

    NASA Astrophysics Data System (ADS)

    Krivorotko, Olga; Kabanikhin, Sergey

    2014-05-01

    One of the most urgent problems of mathematical tsunami modeling is estimation of a tsunami wave height while a wave approaches to the coastal zone. There are two methods for solving this problem, namely, Airy-Green formula in one-dimensional case ° --- S(x) = S(0) 4 H(0)/H (x), and numerical solution of an initial-boundary value problem for linear shallow water equations ( { ηtt = div (gH (x,y)gradη), (x,y,t) ∈ ΩT := Ω ×(0,T); ( η|t=0 = q(x,y), ηt|t=0 = 0, (x,y ) ∈ Ω := (0,Lx)× (0,Ly ); (1) η|δΩT = 0. Here η(x,y,t) is the free water surface vertical displacement, H(x,y) is the depth at point (x,y), q(x,y) is the initial amplitude of a tsunami wave, S(x) is a moving tsunami wave height at point x. The main difficulty problem of tsunami modeling is a very big size of the computational domain ΩT. The calculation of the function η(x,y,t) of three variables in ΩT requires large computing resources. We construct a new algorithm to solve numerically the problem of determining the moving tsunami wave height which is based on kinematic-type approach and analytical representation of fundamental solution (2). The wave is supposed to be generated by the seismic fault of the bottom η(x,y,0) = g(y) ·θ(x), where θ(x) is a Heaviside theta-function. Let τ(x,y) be a solution of the eikonal equation 1 τ2x +τ2y = --, gH (x,y) satisfying initial conditions τ(0,y) = 0 and τx(0,y) = (gH (0,y))-1/2. Introducing new variables and new functions: ° -- z = τ(x,y), u(z,y,t) = ηt(x,y,t), b(z,y) = gH(x,y). We obtain an initial-boundary value problem in new variables from (1) ( 2 2 (2 bz- ) { utt = uzz + b uyy + 2b τyuzy + b(τxx + τyy) + 2b + 2bbyτy uz+ ( +2b(bzτy + by)uy, z,y- >2 0,t > 0,2 -1/2 u|t 0,t > 0. Then after some mathematical transformation we get the structure of the function u(x,y,t) in the form u(z,y,t) = S(z,y)·θ(t - z) + ˜u(z,y,t). (2) Here Å©(z,y,t) is a smooth function, S(z,y) is the solution of the problem: { S + b2τ S + (1b2(τ +

  5. An Improved Interacting Multiple Model Filtering Algorithm Based on the Cubature Kalman Filter for Maneuvering Target Tracking.

    PubMed

    Zhu, Wei; Wang, Wei; Yuan, Gannan

    2016-06-01

    In order to improve the tracking accuracy, model estimation accuracy and quick response of multiple model maneuvering target tracking, the interacting multiple models five degree cubature Kalman filter (IMM5CKF) is proposed in this paper. In the proposed algorithm, the interacting multiple models (IMM) algorithm processes all the models through a Markov Chain to simultaneously enhance the model tracking accuracy of target tracking. Then a five degree cubature Kalman filter (5CKF) evaluates the surface integral by a higher but deterministic odd ordered spherical cubature rule to improve the tracking accuracy and the model switch sensitivity of the IMM algorithm. Finally, the simulation results demonstrate that the proposed algorithm exhibits quick and smooth switching when disposing different maneuver models, and it also performs better than the interacting multiple models cubature Kalman filter (IMMCKF), interacting multiple models unscented Kalman filter (IMMUKF), 5CKF and the optimal mode transition matrix IMM (OMTM-IMM).

  6. On the Impact of Localization and Density Control Algorithms in Target Tracking Applications for Wireless Sensor Networks

    PubMed Central

    Campos, Andre N.; Souza, Efren L.; Nakamura, Fabiola G.; Nakamura, Eduardo F.; Rodrigues, Joel J. P. C.

    2012-01-01

    Target tracking is an important application of wireless sensor networks. The networks' ability to locate and track an object is directed linked to the nodes' ability to locate themselves. Consequently, localization systems are essential for target tracking applications. In addition, sensor networks are often deployed in remote or hostile environments. Therefore, density control algorithms are used to increase network lifetime while maintaining its sensing capabilities. In this work, we analyze the impact of localization algorithms (RPE and DPE) and density control algorithms (GAF, A3 and OGDC) on target tracking applications. We adapt the density control algorithms to address the k-coverage problem. In addition, we analyze the impact of network density, residual integration with density control, and k-coverage on both target tracking accuracy and network lifetime. Our results show that DPE is a better choice for target tracking applications than RPE. Moreover, among the evaluated density control algorithms, OGDC is the best option among the three. Although the choice of the density control algorithm has little impact on the tracking precision, OGDC outperforms GAF and A3 in terms of tracking time. PMID:22969329

  7. On the impact of localization and density control algorithms in target tracking applications for wireless sensor networks.

    PubMed

    Campos, Andre N; Souza, Efren L; Nakamura, Fabiola G; Nakamura, Eduardo F; Rodrigues, Joel J P C

    2012-01-01

    Target tracking is an important application of wireless sensor networks. The networks' ability to locate and track an object is directed linked to the nodes' ability to locate themselves. Consequently, localization systems are essential for target tracking applications. In addition, sensor networks are often deployed in remote or hostile environments. Therefore, density control algorithms are used to increase network lifetime while maintaining its sensing capabilities. In this work, we analyze the impact of localization algorithms (RPE and DPE) and density control algorithms (GAF, A3 and OGDC) on target tracking applications. We adapt the density control algorithms to address the k-coverage problem. In addition, we analyze the impact of network density, residual integration with density control, and k-coverage on both target tracking accuracy and network lifetime. Our results show that DPE is a better choice for target tracking applications than RPE. Moreover, among the evaluated density control algorithms, OGDC is the best option among the three. Although the choice of the density control algorithm has little impact on the tracking precision, OGDC outperforms GAF and A3 in terms of tracking time.

  8. Fast Grid Search Algorithm for Seismic Source Location

    SciTech Connect

    ALDRIDGE,DAVID F.

    2000-07-01

    The spatial and temporal origin of a seismic energy source are estimated with a first grid search technique. This approach has greater likelihood of finding the global rninirnum of the arrival time misiit function compared with conventional linearized iterative methods. Assumption of a homogeneous and isotropic seismic velocity model allows for extremely rapid computation of predicted arrival times, but probably limits application of the method to certain geologic environments and/or recording geometries. Contour plots of the arrival time misfit function in the vicinity of the global minimum are extremely useful for (i) quantizing the uncertainty of an estimated hypocenter solution and (ii) analyzing the resolving power of a given recording configuration. In particular, simultaneous inversion of both P-wave and S-wave arrival times appears to yield a superior solution in the sense of being more precisely localized in space and time. Future research with this algorithm may involve (i) investigating the utility of nonuniform residual weighting schemes, (ii) incorporating linear and/or layered velocity models into the calculation of predicted arrival times, and (iii) applying it toward rational design of microseismic monitoring networks.

  9. Fast registration algorithm using a variational principle for mutual information

    NASA Astrophysics Data System (ADS)

    Alexander, Murray E.; Summers, Randy

    2003-05-01

    A method is proposed for cross-modal image registration based on mutual information (MI) matching criteria. Both conventional and "normalized" MI are considered. MI may be expressed as a functional of a general image displacement field u. The variational principle for MI provides a field equation for u. The method employs a set of "registration points" consisting of a prescribed number of strongest edge points of the reference image, and minimizes an objective function D defined as the sum of the square residuals of the field equation for u at these points, where u is expressed as a sum over a set of basis functions (the affine model is presented here). D has a global minimum when the images are aligned, with a "basin of attraction" typically of width ~0.3 pixels. By pre-filtering with a low-pass filter, and using a multiresolution image pyramid, the basin may be significantly widened. The Levenberg-Marquardt algorithm is used to minimize D. Tests using randomly distributed misalignments of image pairs show that registration accuracy of 0.02 - 0.07 pixels is achieved, when using cubic B-splines for image representation, interpolation, and Parzen window estimation.

  10. Eye-Tracking Verification of the Strategy Used to Analyse Algorithms Expressed in a Flowchart and Pseudocode

    ERIC Educational Resources Information Center

    Andrzejewska, Magdalena; Stolinska, Anna; Blasiak, Wladyslaw; Peczkowski, Pawel; Rosiek, Roman; Rozek, Bozena; Sajka, Miroslawa; Wcislo, Dariusz

    2016-01-01

    The results of qualitative and quantitative investigations conducted with individuals who learned algorithms in school are presented in this article. In these investigations, eye-tracking technology was used to follow the process of solving algorithmic problems. The algorithmic problems were presented in two comparable variants: in a pseudocode…

  11. Quantitative evaluation of image processing algorithms for ill-structured road detection and tracking

    NASA Astrophysics Data System (ADS)

    Dufourd, Delphine; Dalgalarrondo, Andre

    2003-09-01

    In a previous presentation at AeroSense 2002, we described a methodology to assess the results of image processing algorithms for ill-structured road detection and tracking. In this paper, we present our first application of this methodology on sixedge detectors and a database counting about 20,000 images. Our evaluation approach is based on the use of video image sequences, ground truth - reference results established by human experts - and assessment metrics which measure the quality of the image processing results. We need a quantitative, comparative and repetitive evaluation of many algorithms in order to direct future developments. The main scope of this paper consists in presenting the lessons learned from applying our methodology. More precisely, we describe the assessment metrics, the algorithms and the database. Then we describe how we manage to extract the qualities and weaknesses of each algorithm and to establish a global scoring. The insight we gain for the definition of assessment metrics is also presented. Finally, we suggest some promising directions for the development of road tracking algorithms and complementarities that must be sought after. To conclude, we describe future improvements for the database constitution, the assessment tools and the overall methodology.

  12. Experiments of two pupil lateral motion tracking algorithms using a Shack-Hartmann sensor

    NASA Astrophysics Data System (ADS)

    Dai, Xiaolin; Hippler, Stefan; Gendron, Eric

    2017-01-01

    Pupil stability is one of the factors which limit the performance and operational stability of adaptive optics (AO) systems. This paper analyses two pupil-tracking methods to measure the lateral pupil shift: the first one utilizes the fluxes in all outer edge sub-apertures of a Shack-Hartmann sensor and the second one utilizes the real-time interaction matrix used in an AO system. Experiments with 9×9 Shack-Hartmann sensor are conducted to verify both pupil-tracking algorithms. The results show that both algorithms are effective, after two correction steps, the residual pupil shift is reduced to less than 5% of a Shack-Hartmann sub-aperture.

  13. Multiple target tracking algorithm research on IR fish-eye lens system

    NASA Astrophysics Data System (ADS)

    Li, Gang; Lu, Xuguang; He, Yongqiang; Shen, HongBin; Xu, ChunMei; Wang, Yuanbo

    2009-11-01

    The paper presents the algorithms of data process on multi-target tracking and threat level sequence in large visual area IR (infrared ray) fish-eye system. The targeting information is associated and filtered with the polar coordinates. Firstly,The characteristic point of every target is picked up and tracked with special restriction for each of them. Secondly,the parameters of fairway, which are gained by aberration revising and researching the characters of temperature area, are picked up from serial images. The threat level of attacking objects is sorted by the speed, acceleration and direction of all targets. Finding out the most prior target which is in the certain distance in order to make sure that effective warning information is emitted in time. The algorithms are proved to be quick and effective through simulation and the muiti-target experiment system developed by the writers.

  14. "Mtrack 1.0": A multi-vehicle, deterministic tracking algorithm

    SciTech Connect

    Carrano, C J

    2008-05-22

    As overhead persistent surveillance sensors become more capable at acquiring wide-field image sequences for longer time-spans, the need to exploit such data becomes ever greater. A desirable use of such sensors is to be able to track all the observable vehicles while they persist in the imagery. Typically, this imagery is characterized by lower resolutions (e.g. >= 0.5 m/pixel ) and lower frame rates (e.g. {approx} few Hz). We describe our initial implementation of a multiple-vehicle tracking algorithm for overhead persistent surveillance imagery. Subsequent reports will then present results of applying this tracker to specific persistent surveillance imagery as well as algorithm improvements and extensions for dealing with wider-field imagery.

  15. Modified fast frequency acquisition via adaptive least squares algorithm

    NASA Technical Reports Server (NTRS)

    Kumar, Rajendra (Inventor)

    1992-01-01

    A method and the associated apparatus for estimating the amplitude, frequency, and phase of a signal of interest are presented. The method comprises the following steps: (1) inputting the signal of interest; (2) generating a reference signal with adjustable amplitude, frequency and phase at an output thereof; (3) mixing the signal of interest with the reference signal and a signal 90 deg out of phase with the reference signal to provide a pair of quadrature sample signals comprising respectively a difference between the signal of interest and the reference signal and a difference between the signal of interest and the signal 90 deg out of phase with the reference signal; (4) using the pair of quadrature sample signals to compute estimates of the amplitude, frequency, and phase of an error signal comprising the difference between the signal of interest and the reference signal employing a least squares estimation; (5) adjusting the amplitude, frequency, and phase of the reference signal from the numerically controlled oscillator in a manner which drives the error signal towards zero; and (6) outputting the estimates of the amplitude, frequency, and phase of the error signal in combination with the reference signal to produce a best estimate of the amplitude, frequency, and phase of the signal of interest. The preferred method includes the step of providing the error signal as a real time confidence measure as to the accuracy of the estimates wherein the closer the error signal is to zero, the higher the probability that the estimates are accurate. A matrix in the estimation algorithm provides an estimate of the variance of the estimation error.

  16. Fast one-pass algorithm to label objects and compute their features

    NASA Astrophysics Data System (ADS)

    Thai, Tan Q.

    1991-12-01

    In many image processing applications, labeling objects and computing their features for recognition are crucial steps for further analysis. In general these two steps are done separately. This paper proposes a new approach to label all objects and computer their features (such as moments, best fit ellipse, major and minor axis) in one pass. The basic idea of the algorithm is to detect interval overlaps among the line segments as the image is scanned from left to right, top to bottom. Ambiguity about an object's connectivity can also be resolved with the proposed algorithm. It is a fast algorithm and can be implemented on either serial or parallel processors.

  17. Residual Elimination Algorithm Enhancements to Improve Foot Motion Tracking During Forward Dynamic Simulations of Gait.

    PubMed

    Jackson, Jennifer N; Hass, Chris J; Fregly, Benjamin J

    2015-11-01

    Patient-specific gait optimizations capable of predicting post-treatment changes in joint motions and loads could improve treatment design for gait-related disorders. To maximize potential clinical utility, such optimizations should utilize full-body three-dimensional patient-specific musculoskeletal models, generate dynamically consistent gait motions that reproduce pretreatment marker measurements closely, and achieve accurate foot motion tracking to permit deformable foot-ground contact modeling. This study enhances an existing residual elimination algorithm (REA) Remy, C. D., and Thelen, D. G., 2009, “Optimal Estimation of Dynamically Consistent Kinematics and Kinetics for Forward Dynamic Simulation of Gait,” ASME J. Biomech. Eng., 131(3), p. 031005) to achieve all three requirements within a single gait optimization framework. We investigated four primary enhancements to the original REA: (1) manual modification of tracked marker weights, (2) automatic modification of tracked joint acceleration curves, (3) automatic modification of algorithm feedback gains, and (4) automatic calibration of model joint and inertial parameter values. We evaluated the enhanced REA using a full-body three-dimensional dynamic skeletal model and movement data collected from a subject who performed four distinct gait patterns: walking, marching, running, and bounding. When all four enhancements were implemented together, the enhanced REA achieved dynamic consistency with lower marker tracking errors for all segments, especially the feet (mean root-mean-square (RMS) errors of 3.1 versus 18.4 mm), compared to the original REA. When the enhancements were implemented separately and in combinations, the most important one was automatic modification of tracked joint acceleration curves, while the least important enhancement was automatic modification of algorithm feedback gains. The enhanced REA provides a framework for future gait optimization studies that seek to predict subject

  18. Comparing precorrected-FFT and fast multipole algorithms for solving three-dimensional potential integral equations

    SciTech Connect

    White, J.; Phillips, J.R.; Korsmeyer, T.

    1994-12-31

    Mixed first- and second-kind surface integral equations with (1/r) and {partial_derivative}/{partial_derivative} (1/r) kernels are generated by a variety of three-dimensional engineering problems. For such problems, Nystroem type algorithms can not be used directly, but an expansion for the unknown, rather than for the entire integrand, can be assumed and the product of the singular kernal and the unknown integrated analytically. Combining such an approach with a Galerkin or collocation scheme for computing the expansion coefficients is a general approach, but generates dense matrix problems. Recently developed fast algorithms for solving these dense matrix problems have been based on multipole-accelerated iterative methods, in which the fast multipole algorithm is used to rapidly compute the matrix-vector products in a Krylov-subspace based iterative method. Another approach to rapidly computing the dense matrix-vector products associated with discretized integral equations follows more along the lines of a multigrid algorithm, and involves projecting the surface unknowns onto a regular grid, then computing using the grid, and finally interpolating the results from the regular grid back to the surfaces. Here, the authors describe a precorrectted-FFT approach which can replace the fast multipole algorithm for accelerating the dense matrix-vector product associated with discretized potential integral equations. The precorrected-FFT method, described below, is an order n log(n) algorithm, and is asymptotically slower than the order n fast multipole algorithm. However, initial experimental results indicate the method may have a significant constant factor advantage for a variety of engineering problems.

  19. Fast pattern recognizer for autonomous target recognition and tracking for advanced naval attack missiles

    NASA Astrophysics Data System (ADS)

    Hastbacka, Al

    2001-10-01

    A FPR System under development for the Naval Air Warfare Center, China Lake, CA is funded under a SBIR, Phase II contract as an automatic target recognizer and tracker candidate for Navy fast-reaction, subsonic and supersonic, stand-off weapons. The FPR will autonomously detect, identify, correlate, and track complex surface ship and land based targets in hostile, high-clutter environments in real time. The novel FPR system is proven technology that uses an electronic implementation analogous to an optical correlator system, where the Fourier transform of the incoming image is compared against known target images stored as matched filter templates. FPR demonstrations show that unambiguous target identification is achievable in a ninety-five percent fog obscuration for over ninety-percent of target images tested. The FPR technology employs an acoustic dispersive delay line (DDL) to achieve ultra-fast image correlations in 90 microseconds or 11,000 correlations per second. The massively scalable FPR design is capable of achieving processing speeds of an order of magnitude faster using available ASIC technology. Key benefits of the FPR are dramatically reduced power, size, weight, and cost with increased durability, robustness, and performance - which makes the FPR ideal for onboard missile applications.

  20. Constructing Fast Carrier Tracks into Flexible Perovskite Photodetectors To Greatly Improve Responsivity.

    PubMed

    Li, Xiaoming; Yu, Dejian; Chen, Jun; Wang, Yue; Cao, Fei; Wei, Yi; Wu, Ye; Wang, Lin; Zhu, Ying; Sun, Zhiguo; Ji, Jianping; Shen, Yalong; Sun, Handong; Zeng, Haibo

    2017-02-28

    Intrinsically high mobility and large absorption coefficient endow inorganic halide perovskites (IHPs) with great promise for high-performance photodetectors (PDs), which, however, are being hindered by the low carrier extraction and transport efficiency of the solution assembled films. Here, we report on a general strategy to enhance the perovskite film conductivity that carbon nanotubes (CNTs) conductive nanonets are constructed from to provide fast carrier tracks. Resultantly, the CsPbBr3 nanosheet/CNT composite films exhibit both high light harvesting and high conductivity, such advantages are demonstrated by the high performances of corresponding planar PDs. Specifically, the highest external quantum efficiency (EQE) of 7488% and the highest responsivity of 31.1 A W(-1) under a bias of 10 V among IHP PDs with planar structure are achieved, which are almost 125-fold over the previous best results. Besides, the efficient charge extraction and transport also remarkably contribute to the fast response speed where a rise time of 16 μs is achieved, which is also superior to state-of-the-art IHP PDs. Furthermore, the composite films exhibit impressive flexibility due to the ultrathin 2D and 1D structural characteristic of perovskites and CNTs. By deploying the PD as a point-like detector, we acquire clear images. The results indicate the promising potentials of the perovskite/CNT composites for solution and ambient condition processed flexible devices, and this strategy is general for all kinds of perovskite optoelectronic devices including photodetectors, phototransistors, and even LEDs.

  1. PTM Along Track Algorithm to Maintain Spacing During Same Direction Pair-Wise Trajectory Management Operations

    NASA Technical Reports Server (NTRS)

    Carreno, Victor A.

    2015-01-01

    Pair-wise Trajectory Management (PTM) is a cockpit based delegated responsibility separation standard. When an air traffic service provider gives a PTM clearance to an aircraft and the flight crew accepts the clearance, the flight crew will maintain spacing and separation from a designated aircraft. A PTM along track algorithm will receive state information from the designated aircraft and from the own ship to produce speed guidance for the flight crew to maintain spacing and separation

  2. A Parallelization Scheme of the Periodic Signals Tracking Algorithm for Isochronous Mass Spectrometry on GPUs

    NASA Astrophysics Data System (ADS)

    Chen, Ruijiu; Wang, Meng; Yan, Xinliang; Yang, Qiong; Lam, Yihua; Yang, Lei; Zhang, Yuhu

    We developed a new program by using a parallelization scheme of the periodic signals tracking algorithm for isochronous mass spectrometry on GPUs. The computing time of data analysis can be reduced by a factor of ˜71 and ˜346 by using our new program on Tesla C1060 GPU and Tesla K20c GPU, compared to using old program on Xeon E5540 CPU. We succeed in performing real-time data analysis by using this new program.

  3. A Matrix Computation View of the FastMap and RobustMap Dimension Reduction Algorithms

    SciTech Connect

    Ostrouchov, George

    2009-01-01

    Given a set of pairwise object distances and a dimension $k$, FastMap and RobustMap algorithms compute a set of $k$-dimensional coordinates for the objects. These metric space embedding methods implicitly assume a higher-dimensional coordinate representation and are a sequence of translations and orthogonal projections based on a sequence of object pair selections (called pivot pairs). We develop a matrix computation viewpoint of these algorithms that operates on the coordinate representation explicitly using Householder reflections. The resulting Coordinate Mapping Algorithm (CMA) is a fast approximate alternative to truncated principal component analysis (PCA) and it brings the FastMap and RobustMap algorithms into the mainstream of numerical computation where standard BLAS building blocks are used. Motivated by the geometric nature of the embedding methods, we further show that truncated PCA can be computed with CMA by specific pivot pair selections. Describing FastMap, RobustMap, and PCA as CMA computations with different pivot pair choices unifies the methods along a pivot pair selection spectrum. We also sketch connections to the semi-discrete decomposition and the QLP decomposition.

  4. Preliminary versions of the MATLAB tensor classes for fast algorithm prototyping.

    SciTech Connect

    Bader, Brett William; Kolda, Tamara Gibson

    2004-07-01

    We present the source code for three MATLAB classes for manipulating tensors in order to allow fast algorithm prototyping. A tensor is a multidimensional or Nway array. This is a supplementary report; details on using this code are provided separately in SAND-XXXX.

  5. A fast algorithm for depth migration by the Gaussian beam summation method

    NASA Astrophysics Data System (ADS)

    Gao, Zhenghui; Sun, Jianguo; Sun, Xu; Wang, Xueqiu; Sun, Zhangqing; Liu, Zhiqiang

    2017-02-01

    Depth migration by the Gaussian beam summation method has no limitation on the seismic acquisition configuration. In the past, this migration method applied the steepest descent approximation to reduce the dimension of the integrals over the ray parameters at the cost of a precision loss. However, the simplified formula was still in the frequency domain, thereby impairing the computational efficiency. We present a new fast algorithm which can increase the computational efficiency without losing precision. To develop the fast algorithm, we change the order of the integrals and treat the two innermost integrals as a couple of two-dimensional continuous functions with respect to the real and imaginary parts of the total traveltime. A couple of lookup tables corresponding to the values of the two innermost integrals are constructed at the sampling points. The results of the two innermost integrals at a certain imaging point can be obtained through interpolation in the two constructed lookup tables. Both the numerical analysis and examples validate the precision and efficiency of the fast algorithm. With the advantage of handling rugged topography, we apply the fast algorithm to the 2D Canadian Foothills velocity model.

  6. A fast-initializing digital equalizer with on-line tracking for data communications

    NASA Technical Reports Server (NTRS)

    Houts, R. C.; Barksdale, W. J.

    1974-01-01

    A theory is developed for a digital equalizer for use in reducing intersymbol interference (ISI) on high speed data communications channels. The equalizer is initialized with a single isolated transmitter pulse, provided the signal-to-noise ratio (SNR) is not unusually low, then switches to a decision directed, on-line mode of operation that allows tracking of channel variations. Conditions for optimal tap-gain settings are obtained first for a transversal equalizer structure by using a mean squared error (MSE) criterion, a first order gradient algorithm to determine the adjustable equalizer tap-gains, and a sequence of isolated initializing pulses. Since the rate of tap-gain convergence depends on the eigenvalues of a channel output correlation matrix, convergence can be improved by making a linear transformation on to obtain a new correlation matrix.

  7. Predictive filtering-based fast reacquisition approach for space-borne acquisition, tracking, and pointing systems.

    PubMed

    Bai, Shuai; Wang, Jianyu; Qiang, Jia; Zhang, Liang; Wang, Juanjuan

    2014-11-03

    We propose a novel approach for recapturing targets as quickly as possible after the space-borne ATP (Acquisition, Tracking, and Pointing) system target loss in free-space laser communication. The approach uses past angular information to predict the target trajectory. An optimized finite memory filter is designed as the prediction algorithm. To obtain optimal prediction performance, the designed filter determines the filter parameters of different curve parts during offline training, and the parameters are adjusted according to the curve characteristics during predictive filtering. Simulation results indicate prediction accuracy above 0.1 degrees within 5 seconds. An experimental system was constructed in the lab to simulate the reacquisition process using a dynamic target and a real ATP system. Experimental results show that, compared with the classical orbit prediction method, this approach can effectively yield shorter acquisition times.

  8. Fast, Conservative Algorithm for Solving the Transonic Full-Potential Equation

    NASA Technical Reports Server (NTRS)

    Holst, Terry L.

    1980-01-01

    A fast, fully implicit approximate factorization algorithm designed to solve the conservative, transonic, full-potential equation in either two or three dimensions is described. The algorithm uses an upwind bias of the density coefficient for stability in supersonic regions. This provides an effective upwind difference of the streamwise terms for any orientation of the velocity vector (i.e., rotated differencing), thereby greatly enhancing the reliability of the present algorithm. A numerical transformation is used to establish an arbitrary body-fitted, finite-difference mesh. Computed results for both airfoils and simplified wings demonstrate substantial improvement in convergence speed for the new algorithm relative to standard successive-line over-relaxation algorithms.

  9. A fast iterative recursive least squares algorithm for Wiener model identification of highly nonlinear systems.

    PubMed

    Kazemi, Mahdi; Arefi, Mohammad Mehdi

    2017-03-01

    In this paper, an online identification algorithm is presented for nonlinear systems in the presence of output colored noise. The proposed method is based on extended recursive least squares (ERLS) algorithm, where the identified system is in polynomial Wiener form. To this end, an unknown intermediate signal is estimated by using an inner iterative algorithm. The iterative recursive algorithm adaptively modifies the vector of parameters of the presented Wiener model when the system parameters vary. In addition, to increase the robustness of the proposed method against variations, a robust RLS algorithm is applied to the model. Simulation results are provided to show the effectiveness of the proposed approach. Results confirm that the proposed method has fast convergence rate with robust characteristics, which increases the efficiency of the proposed model and identification approach. For instance, the FIT criterion will be achieved 92% in CSTR process where about 400 data is used.

  10. a Fast and Robust Algorithm for Road Edges Extraction from LIDAR Data

    NASA Astrophysics Data System (ADS)

    Qiu, Kaijin; Sun, Kai; Ding, Kou; Shu, Zhen

    2016-06-01

    Fast mapping of roads plays an important role in many geospatial applications, such as infrastructure planning, traffic monitoring, and driver assistance. How to extract various road edges fast and robustly is a challenging task. In this paper, we present a fast and robust algorithm for the automatic road edges extraction from terrestrial mobile LiDAR data. The algorithm is based on a key observation: most roads around edges have difference in elevation and road edges with pavement are seen in two different planes. In our algorithm, we firstly extract a rough plane based on RANSAC algorithm, and then multiple refined planes which only contains pavement are extracted from the rough plane. The road edges are extracted based on these refined planes. In practice, there is a serious problem that the rough and refined planes usually extracted badly due to rough roads and different density of point cloud. To eliminate the influence of rough roads, the technology which is similar with the difference of DSM (digital surface model) and DTM (digital terrain model) is used, and we also propose a method which adjust the point clouds to a similar density to eliminate the influence of different density. Experiments show the validities of the proposed method with multiple datasets (e.g. urban road, highway, and some rural road). We use the same parameters through the experiments and our algorithm can achieve real-time processing speeds.

  11. A fast inter mode decision algorithm in H.264/AVC for IPTV broadcasting services

    NASA Astrophysics Data System (ADS)

    Kim, Geun-Yong; Yoon, Bin-Yeong; Ho, Yo-Sung

    2007-01-01

    The new video coding standard H.264/AVC employs the rate-distortion optimization (RDO) method for choosing the best coding mode. However, since it increases the encoder complexity tremendously, it is not suitable for real-time applications, such as IPTV broadcasting services. Therefore we need a fast mode decision algorithm to reduce its encoding time. In this paper, we propose a fast mode decision algorithm considering quantization parameter (QP) because we have noticed that the frequency of best modes depends on QP. In order to consider these characteristics, we use the coded block pattern (CBP) that has "0" value when all quantized discrete cosine transform (DCT) coefficients are zero. We also use both the early SKIP mode and early 16x16 mode decisions. Experimental results show that the proposed algorithm reduces the encoding time by 74.6% for the baseline profile and 72.8% for the main profile, compared to the H.264/AVC reference software.

  12. An evolutionary computation based algorithm for calculating solar differential rotation by automatic tracking of coronal bright points

    NASA Astrophysics Data System (ADS)

    Shahamatnia, Ehsan; Dorotovič, Ivan; Fonseca, Jose M.; Ribeiro, Rita A.

    2016-03-01

    Developing specialized software tools is essential to support studies of solar activity evolution. With new space missions such as Solar Dynamics Observatory (SDO), solar images are being produced in unprecedented volumes. To capitalize on that huge data availability, the scientific community needs a new generation of software tools for automatic and efficient data processing. In this paper a prototype of a modular framework for solar feature detection, characterization, and tracking is presented. To develop an efficient system capable of automatic solar feature tracking and measuring, a hybrid approach combining specialized image processing, evolutionary optimization, and soft computing algorithms is being followed. The specialized hybrid algorithm for tracking solar features allows automatic feature tracking while gathering characterization details about the tracked features. The hybrid algorithm takes advantages of the snake model, a specialized image processing algorithm widely used in applications such as boundary delineation, image segmentation, and object tracking. Further, it exploits the flexibility and efficiency of Particle Swarm Optimization (PSO), a stochastic population based optimization algorithm. PSO has been used successfully in a wide range of applications including combinatorial optimization, control, clustering, robotics, scheduling, and image processing and video analysis applications. The proposed tool, denoted PSO-Snake model, was already successfully tested in other works for tracking sunspots and coronal bright points. In this work, we discuss the application of the PSO-Snake algorithm for calculating the sidereal rotational angular velocity of the solar corona. To validate the results we compare them with published manual results performed by an expert.

  13. A fast and accurate algorithm for high-frequency trans-ionospheric path length determination

    NASA Astrophysics Data System (ADS)

    Wijaya, Dudy D.

    2015-12-01

    This paper presents a fast and accurate algorithm for high-frequency trans-ionospheric path length determination. The algorithm is merely based on the solution of the Eikonal equation that is solved using the conformal theory of refraction. The main advantages of the algorithm are summarized as follows. First, the algorithm can determine the optical path length without iteratively adjusting both elevation and azimuth angles and, hence, the computational time can be reduced. Second, for the same elevation and azimuth angles, the algorithm can simultaneously determine the phase and group of both ordinary and extra-ordinary optical path lengths for different frequencies. Results from numerical simulations show that the computational time required by the proposed algorithm to accurately determine 8 different optical path lengths is almost 17 times faster than that required by a 3D ionospheric ray-tracing algorithm. It is found that the computational time to determine multiple optical path lengths is the same with that for determining a single optical path length. It is also found that the proposed algorithm is capable of determining the optical path lengths with millimeter level of accuracies, if the magnitude of the squared ratio of the plasma frequency to the transmitted frequency is less than 1.33× 10^{-3}, and hence the proposed algorithm is applicable for geodetic applications.

  14. Speed-up hyperspheres homotopic path tracking algorithm for PWL circuits simulations.

    PubMed

    Ramirez-Pinero, A; Vazquez-Leal, H; Jimenez-Fernandez, V M; Sedighi, H M; Rashidi, M M; Filobello-Nino, U; Castaneda-Sheissa, R; Huerta-Chua, J; Sarmiento-Reyes, L A; Laguna-Camacho, J R; Castro-Gonzalez, F

    2016-01-01

    In the present work, we introduce an improved version of the hyperspheres path tracking method adapted for piecewise linear (PWL) circuits. This enhanced version takes advantage of the PWL characteristics from the homotopic curve, achieving faster path tracking and improving the performance of the homotopy continuation method (HCM). Faster computing time allows the study of complex circuits with higher complexity; the proposed method also decrease, significantly, the probability of having a diverging problem when using the Newton-Raphson method because it is applied just twice per linear region on the homotopic path. Equilibrium equations of the studied circuits are obtained applying the modified nodal analysis; this method allows to propose an algorithm for nonlinear circuit analysis. Besides, a starting point criteria is proposed to obtain better performance of the HCM and a technique for avoiding the reversion phenomenon is also proposed. To prove the efficiency of the path tracking method, several cases study with bipolar (BJT) and CMOS transistors are provided. Simulation results show that the proposed approach can be up to twelve times faster than the original path tracking method and also helps to avoid several reversion cases that appears when original hyperspheres path tracking scheme was employed.

  15. Detailed Evaluation of Five 3D Speckle Tracking Algorithms Using Synthetic Echocardiographic Recordings.

    PubMed

    Alessandrini, Martino; Heyde, Brecht; Queiros, Sandro; Cygan, Szymon; Zontak, Maria; Somphone, Oudom; Bernard, Olivier; Sermesant, Maxime; Delingette, Herve; Barbosa, Daniel; De Craene, Mathieu; ODonnell, Matthew; Dhooge, Jan

    2016-08-01

    A plethora of techniques for cardiac deformation imaging with 3D ultrasound, typically referred to as 3D speckle tracking techniques, are available from academia and industry. Although the benefits of single methods over alternative ones have been reported in separate publications, the intrinsic differences in the data and definitions used makes it hard to compare the relative performance of different solutions. To address this issue, we have recently proposed a framework to simulate realistic 3D echocardiographic recordings and used it to generate a common set of ground-truth data for 3D speckle tracking algorithms, which was made available online. The aim of this study was therefore to use the newly developed database to contrast non-commercial speckle tracking solutions from research groups with leading expertise in the field. The five techniques involved cover the most representative families of existing approaches, namely block-matching, radio-frequency tracking, optical flow and elastic image registration. The techniques were contrasted in terms of tracking and strain accuracy. The feasibility of the obtained strain measurements to diagnose pathology was also tested for ischemia and dyssynchrony.

  16. Raw data based image processing algorithm for fast detection of surface breaking cracks

    NASA Astrophysics Data System (ADS)

    Sruthi Krishna K., P.; Puthiyaveetil, Nithin; Kidangan, Renil; Unnikrishnakurup, Sreedhar; Zeigler, Mathias; Myrach, Philipp; Balasubramaniam, Krishnan; Biju, P.

    2017-02-01

    The aim of this work is to illustrate the contribution of signal processing techniques in the field of Non-Destructive Evaluation. A component's life evaluation is inevitably related to the presence of flaws in it. The detection and characterization of cracks prior to damage is a technologically and economically significant task and is of very importance when it comes to safety-relevant measures. The Laser Thermography is the most effective and advanced thermography method for Non-Destructive Evaluation. High capability for the detection of surface cracks and for the characterization of the geometry of artificial surface flaws in metallic samples of laser thermography is particularly encouraging. This is one of the non-contacting, fast and real time detection method. The presence of a vertical surface breaking crack will disturb the thermal footprint. The data processing method plays vital role in fast detection of the surface and sub-surface cracks. Currently in laser thermographic inspection lacks a compromising data processing algorithm which is necessary for the fast crack detection and also the analysis of data is done as part of post processing. In this work we introduced a raw data based image processing algorithm which results precise, better and fast crack detection. The algorithm we developed gives better results in both experimental and modeling data. By applying this algorithm we carried out a detailed investigation variation of thermal contrast with crack parameters like depth and width. The algorithm we developed is applied for various surface temperature data from the 2D scanning model and also validated credibility of algorithm with experimental data.

  17. A Fast Algorithm for Denoising Magnitude Diffusion-Weighted Images with Rank and Edge Constraints

    PubMed Central

    Lam, Fan; Liu, Ding; Song, Zhuang; Schuff, Norbert; Liang, Zhi-Pei

    2015-01-01

    Purpose To accelerate denoising of magnitude diffusion-weighted images subject to joint rank and edge constraints. Methods We extend a previously proposed majorize-minimize (MM) method for statistical estimation that involves noncentral χ distributions and joint rank and edge constraints. A new algorithm is derived which decomposes the constrained noncentral χ denoising problem into a series of constrained Gaussian denoising problems each of which is then solved using an efficient alternating minimization scheme. Results The performance of the proposed algorithm has been evaluated using both simulated and experimental data. Results from simulations based on ex vivo data show that the new algorithm achieves about a factor of 10 speed up over the original Quasi-Newton based algorithm. This improvement in computational efficiency enabled denoising of large data sets containing many diffusion-encoding directions. The denoising performance of the new efficient algorithm is found to be comparable to or even better than that of the original slow algorithm. For an in vivo high-resolution Q-ball acquisition, comparison of fiber tracking results around hippocampus region before and after denoising will also be shown to demonstrate the denoising effects of the new algorithm. Conclusion The optimization problem associated with denoising noncentral χ distributed diffusion-weighted images subject to joint rank and edge constraints can be solved efficiently using an MM-based algorithm. PMID:25733066

  18. Catalyzing Country Ownership and Aid Effectiveness: Role of the Education for All-Fast Track Initiative Catalytic Fund

    ERIC Educational Resources Information Center

    Bashir, Sajitha

    2009-01-01

    This article examines the contribution of the Education for All-Fast Track Initiative (EFA-FTI) global partnership in strengthening aid effectiveness in the education sector, and specifically how the implementation modalities of the EFA-FTI Catalytic Fund (CF) have contributed to this strengthening. The empirical findings are based on a review…

  19. Real-time image-processing algorithm for markerless tumour tracking using X-ray fluoroscopic imaging

    PubMed Central

    2014-01-01

    Objective: To ensure accuracy in respiratory-gating treatment, X-ray fluoroscopic imaging is used to detect tumour position in real time. Detection accuracy is strongly dependent on image quality, particularly positional differences between the patient and treatment couch. We developed a new algorithm to improve the quality of images obtained in X-ray fluoroscopic imaging and report the preliminary results. Methods: Two oblique X-ray fluoroscopic images were acquired using a dynamic flat panel detector (DFPD) for two patients with lung cancer. The weighting factor was applied to the DFPD image in respective columns, because most anatomical structures, as well as the treatment couch and port cover edge, were aligned in the superior–inferior direction when the patient lay on the treatment couch. The weighting factors for the respective columns were varied until the standard deviation of the pixel values within the image region was minimized. Once the weighting factors were calculated, the quality of the DFPD image was improved by applying the factors to multiframe images. Results: Applying the image-processing algorithm produced substantial improvement in the quality of images, and the image contrast was increased. The treatment couch and irradiation port edge, which were not related to a patient's position, were removed. The average image-processing time was 1.1 ms, showing that this fast image processing can be applied to real-time tumour-tracking systems. Conclusion: These findings indicate that this image-processing algorithm improves the image quality in patients with lung cancer and successfully removes objects not related to the patient. Advances in knowledge: Our image-processing algorithm might be useful in improving gated-treatment accuracy. PMID:24661056

  20. Fast-track extreme event attribution: How fast can we disentangle thermodynamic (forced) and dynamic (internal) contributions?

    NASA Astrophysics Data System (ADS)

    Haustein, Karsten; Otto, Friederike; Uhe, Peter; Allen, Myles; Cullen, Heidi

    2016-04-01

    provide sufficient guidance to determine the dynamic contribution to the event on the basis of monthly mean values. No such link can be made (North Atlantic/Western Europe region) for shorter time-scales, unless the observed state of the circulation is taken as reference for the model analysis (e.g. Christidis et al. 2014). We present results from our most recent attribution analysis for the December 2015 UK floods (Storm Desmond and Eva), during which we find a robust teleconnection link between Pacific SSTs and North Atlantic Jetstream anomalies. This is true for both experiments, with forecast and observed SSTs. We propose a fast and simple analysis method based on the comparison of current climatological circulation patterns with actual and natural conditions. Alternative methods are discussed and analysed regarding their potential for fast-track attribution of the role of dynamics. Also, we briefly revisit the issue of internal vs forced dynamic contributions.

  1. A ground track control algorithm for the Topographic Mapping Laser Altimeter (TMLA)

    NASA Technical Reports Server (NTRS)

    Blaes, V.; Mcintosh, R.; Roszman, L.; Cooley, J.

    1993-01-01

    The results of an analysis of an algorithm that will provide autonomous onboard orbit control using orbits determined with Global Positioning System (GPS) data. The algorithm uses the GPS data to (1) compute the ground track error relative to a fixed longitude grid, and (2) determine the altitude adjustment required to correct the longitude error. A program was written on a personal computer (PC) to test the concept for numerous altitudes and values of solar flux using a simplified orbit model including only the J sub 2 zonal harmonic and simple orbit decay computations. The algorithm was then implemented in a precision orbit propagation program having a full range of perturbations. The analysis showed that, even with all perturbations (including actual time histories of solar flux variation), the algorithm could effectively control the spacecraft ground track and yield more than 99 percent Earth coverage in the time required to complete one coverage cycle on the fixed grid (220 to 230 days depending on altitude and overlap allowance).

  2. A coded aperture compressive imaging array and its visual detection and tracking algorithms for surveillance systems.

    PubMed

    Chen, Jing; Wang, Yongtian; Wu, Hanxiao

    2012-10-29

    In this paper, we propose an application of a compressive imaging system to the problem of wide-area video surveillance systems. A parallel coded aperture compressive imaging system is proposed to reduce the needed high resolution coded mask requirements and facilitate the storage of the projection matrix. Random Gaussian, Toeplitz and binary phase coded masks are utilized to obtain the compressive sensing images. The corresponding motion targets detection and tracking algorithms directly using the compressive sampling images are developed. A mixture of Gaussian distribution is applied in the compressive image space to model the background image and for foreground detection. For each motion target in the compressive sampling domain, a compressive feature dictionary spanned by target templates and noises templates is sparsely represented. An l(1) optimization algorithm is used to solve the sparse coefficient of templates. Experimental results demonstrate that low dimensional compressed imaging representation is sufficient to determine spatial motion targets. Compared with the random Gaussian and Toeplitz phase mask, motion detection algorithms using a random binary phase mask can yield better detection results. However using random Gaussian and Toeplitz phase mask can achieve high resolution reconstructed image. Our tracking algorithm can achieve a real time speed that is up to 10 times faster than that of the l(1) tracker without any optimization.

  3. Determining residual reduction algorithm kinematic tracking weights for a sidestep cut via numerical optimization.

    PubMed

    Samaan, Michael A; Weinhandl, Joshua T; Bawab, Sebastian Y; Ringleb, Stacie I

    2016-12-01

    Musculoskeletal modeling allows for the determination of various parameters during dynamic maneuvers by using in vivo kinematic and ground reaction force (GRF) data as inputs. Differences between experimental and model marker data and inconsistencies in the GRFs applied to these musculoskeletal models may not produce accurate simulations. Therefore, residual forces and moments are applied to these models in order to reduce these differences. Numerical optimization techniques can be used to determine optimal tracking weights of each degree of freedom of a musculoskeletal model in order to reduce differences between the experimental and model marker data as well as residual forces and moments. In this study, the particle swarm optimization (PSO) and simplex simulated annealing (SIMPSA) algorithms were used to determine optimal tracking weights for the simulation of a sidestep cut. The PSO and SIMPSA algorithms were able to produce model kinematics that were within 1.4° of experimental kinematics with residual forces and moments of less than 10 N and 18 Nm, respectively. The PSO algorithm was able to replicate the experimental kinematic data more closely and produce more dynamically consistent kinematic data for a sidestep cut compared to the SIMPSA algorithm. Future studies should use external optimization routines to determine dynamically consistent kinematic data and report the differences between experimental and model data for these musculoskeletal simulations.

  4. Fast noninvasive eye-tracking and eye-gaze determination for biomedical and remote monitoring applications

    NASA Astrophysics Data System (ADS)

    Talukder, Ashit; Morookian, John M.; Monacos, Steve P.; Lam, Raymond K.; Lebaw, C.; Bond, A.

    2004-04-01

    Eyetracking is one of the latest technologies that has shown potential in several areas including human-computer interaction for people with and without disabilities, and for noninvasive monitoring, detection, and even diagnosis of physiological and neurological problems in individuals. Current non-invasive eyetracking methods achieve a 30 Hz rate with possibly low accuracy in gaze estimation, that is insufficient for many applications. We propose a new non-invasive visual eyetracking system that is capable of operating at speeds as high as 6-12 KHz. A new CCD video camera and hardware architecture is used, and a novel fast image processing algorithm leverages specific features of the input CCD camera to yield a real-time eyetracking system. A field programmable gate array (FPGA) is used to control the CCD camera and execute the image processing operations. Initial results show the excellent performance of our system under severe head motion and low contrast conditions.

  5. Fast phase unwrapping algorithm based on region partition for structured light vision measurement

    NASA Astrophysics Data System (ADS)

    Lu, Jun; Su, Hang

    2014-04-01

    Phase unwrapping is a key problem of phase-shifting profilometry vision measurement for complex object surface shapes. The simple path-following phase unwrapping algorithm is fast but has serious unwrapping error for complex shapes. The Goldstein+flood phase unwrapping algorithm can handle some complex shape object measurement; however, it is time consuming. We propose a fast phase unwrapping algorithm based on region partition according to a quality map of wrapped phase. In this algorithm, wrapped phase image is divided into several regions using partition thresholds, which are determined according to histogram of quality value. Each region is unwrapped by using a simple path-following phase algorithm and several groups with different priorities are generated. These groups are merged according to their priorities from high to low order and a final absolute phase is obtained. The proposed method is applied to wrapped phase images of three objects with and without noise. Experiments show that the proposed method is much faster, more accurate, and robust to noise than the Goldstein+flood algorithm in unwrapping complex phase image.

  6. Image Artifacts Resulting from Gamma-Ray Tracking Algorithms Used with Compton Imagers

    SciTech Connect

    Seifert, Carolyn E.; He, Zhong

    2005-10-01

    For Compton imaging it is necessary to determine the sequence of gamma-ray interactions in a single detector or array of detectors. This can be done by time-of-flight measurements if the interactions are sufficiently far apart. However, in small detectors the time between interactions can be too small to measure, and other means of gamma-ray sequencing must be used. In this work, several popular sequencing algorithms are reviewed for sequences with two observed events and three or more observed events in the detector. These algorithms can result in poor imaging resolution and introduce artifacts in the backprojection images. The effects of gamma-ray tracking algorithms on Compton imaging are explored in the context of the 4π Compton imager built by the University of Michigan.

  7. SU-E-T-764: Track Repeating Algorithm for Proton Therapy Applied to Intensity Modulated Proton Therapy for Head-And-Neck Patients

    SciTech Connect

    Yepes, P; Mirkovic, D; Mohan, R

    2015-06-15

    Purpose: To determine the suitability of fast Monte Carlo techniques for dose calculation in particle therapy based on track-repeating algorithm for Intensity Modulated Proton Therapy, IMPT. The application of this technique will make possible detailed retrospective studies of large cohort of patients, which may lead to a better determination of Relative Biological Effects from the analysis of patient data. Methods: A cohort of six head-and-neck patients treated at the University of Texas MD Anderson Cancer Center with IMPT were utilized. The dose distributions were calculated with the standard Treatment Plan System, TPS, MCNPX, GEANT4 and FDC, a fast track-repeating algorithm for proton therapy for the verification and the patient plans. FDC is based on a GEANT4 database of trajectories of protons in a water. The obtained dose distributions were compared to each other utilizing the g-index criteria for 3mm-3% and 2mm-2%, for the maximum spatial and dose differences. The γ-index was calculated for voxels with a dose at least 10% of the maximum delivered dose. Dose Volume Histograms are also calculated for the various dose distributions. Results: Good agreement between GEANT4 and FDC is found with less than 1% of the voxels with a γ-index larger than 1 for 2 mm-2%. The agreement between MCNPX with FDC is within the requirements of clinical standards, even though it is slightly worse than the comparison with GEANT4.The comparison with TPS yielded larger differences, what is also to be expected because pencil beam algorithm do not always performed well in highly inhomogeneous areas like head-and-neck. Conclusion: The good agreement between a track-repeating algorithm and a full Monte Carlo for a large cohort of patients and a challenging, site like head-and-neck, opens the path to systematic and detailed studies of large cohorts, which may yield better understanding of biological effects.

  8. Meanie3D - a mean-shift based, multivariate, multi-scale clustering and tracking algorithm

    NASA Astrophysics Data System (ADS)

    Simon, Jürgen-Lorenz; Malte, Diederich; Silke, Troemel

    2014-05-01

    Project OASE is the one of 5 work groups at the HErZ (Hans Ertel Centre for Weather Research), an ongoing effort by the German weather service (DWD) to further research at Universities concerning weather prediction. The goal of project OASE is to gain an object-based perspective on convective events by identifying them early in the onset of convective initiation and follow then through the entire lifecycle. The ability to follow objects in this fashion requires new ways of object definition and tracking, which incorporate all the available data sets of interest, such as Satellite imagery, weather Radar or lightning counts. The Meanie3D algorithm provides the necessary tool for this purpose. Core features of this new approach to clustering (object identification) and tracking are the ability to identify objects using the mean-shift algorithm applied to a multitude of variables (multivariate), as well as the ability to detect objects on various scales (multi-scale) using elements of Scale-Space theory. The algorithm works in 2D as well as 3D without modifications. It is an extension of a method well known from the field of computer vision and image processing, which has been tailored to serve the needs of the meteorological community. In spite of the special application to be demonstrated here (like convective initiation), the algorithm is easily tailored to provide clustering and tracking for a wide class of data sets and problems. In this talk, the demonstration is carried out on two of the OASE group's own composite sets. One is a 2D nationwide composite of Germany including C-Band Radar (2D) and Satellite information, the other a 3D local composite of the Bonn/Jülich area containing a high-resolution 3D X-Band Radar composite.

  9. Moment feature based fast feature extraction algorithm for moving object detection using aerial images.

    PubMed

    Saif, A F M Saifuddin; Prabuwono, Anton Satria; Mahayuddin, Zainal Rasyid

    2015-01-01

    Fast and computationally less complex feature extraction for moving object detection using aerial images from unmanned aerial vehicles (UAVs) remains as an elusive goal in the field of computer vision research. The types of features used in current studies concerning moving object detection are typically chosen based on improving detection rate rather than on providing fast and computationally less complex feature extraction methods. Because moving object detection using aerial images from UAVs involves motion as seen from a certain altitude, effective and fast feature extraction is a vital issue for optimum detection performance. This research proposes a two-layer bucket approach based on a new feature extraction algorithm referred to as the moment-based feature extraction algorithm (MFEA). Because a moment represents the coherent intensity of pixels and motion estimation is a motion pixel intensity measurement, this research used this relation to develop the proposed algorithm. The experimental results reveal the successful performance of the proposed MFEA algorithm and the proposed methodology.

  10. A fast and accurate frequency estimation algorithm for sinusoidal signal with harmonic components

    NASA Astrophysics Data System (ADS)

    Hu, Jinghua; Pan, Mengchun; Zeng, Zhidun; Hu, Jiafei; Chen, Dixiang; Tian, Wugang; Zhao, Jianqiang; Du, Qingfa

    2016-10-01

    Frequency estimation is a fundamental problem in many applications, such as traditional vibration measurement, power system supervision, and microelectromechanical system sensors control. In this paper, a fast and accurate frequency estimation algorithm is proposed to deal with low efficiency problem in traditional methods. The proposed algorithm consists of coarse and fine frequency estimation steps, and we demonstrate that it is more efficient than conventional searching methods to achieve coarse frequency estimation (location peak of FFT amplitude) by applying modified zero-crossing technique. Thus, the proposed estimation algorithm requires less hardware and software sources and can achieve even higher efficiency when the experimental data increase. Experimental results with modulated magnetic signal show that the root mean square error of frequency estimation is below 0.032 Hz with the proposed algorithm, which has lower computational complexity and better global performance than conventional frequency estimation methods.

  11. Strain estimation by a Fourier Series-based extrema tracking algorithm for elastography.

    PubMed

    Wang, Wenxia; Hu, Danfeng; Wang, Jiajun; Zou, Wei

    2015-09-01

    In this paper, a new strain estimator using extrema tracking based on Fourier Series expansion (ETBFS) is proposed for ultrasonic elastography. In this method, the extremum is determined by solving an equation constructed by obtaining the first order derivative of the Fourier Series expansion and setting it to zero. Unlike other tracking algorithms, the ETBFS method can locate the extrema of radio frequency (RF) signals exactly between two adjacent sampling points and achieve a sub-sample accuracy without additional explicit interpolation. The correspondence between the located extrema in the pre- and post-compressed RF signal segments are constructed with a fine matching technique, with which the displacements and strains are estimated. Experimental results on a finite-element-modeling (FEM) simulation phantom show that the new proposed method can provide a more accurate displacement estimation than the standard cross-correlation (CC)-based method and the scale-invariant keypoints tracking (SIKT) algorithm. Moreover, performance analysis in terms of elastographic signal-to-noise ratio (SNRe), elastographic contrast-to-noise ratio (CNRe) and the real-versus-estimated strain error (RESE) also indicate that the dynamic range of the strain filter and its sensitivity can be improved with this new method.

  12. "Mtrack 2.0": An ultra-scale tracking algorithm for low-resolution overhead imagery

    SciTech Connect

    Carrano, C J

    2008-09-26

    Overhead persistent surveillance systems are becoming more capable at acquiring wide-field image sequences for long time-spans. The need to exploit this data is becoming ever greater. The ability to track a single vehicle of interest or to track all the observable vehicles, which may number in the thousands, over large, cluttered regions while they persist in the imagery is very desirable. Typically, this imagery has many thousands of pixels on a side and is characterized by lower resolutions (e.g. {approx}0.5 meters/pixel to {approx}2.0 meters/pixel) and lower frame rates (e.g. {approx} sub-Hz to several Hz). We describe our ultra-scale capable implementation of a multiple-vehicle tracking algorithm for overhead persistent surveillance imagery. This work builds upon an earlier report, where now the algorithm has been modified for improved performance and has been substantially improved to handle much larger datasets in a much shorter time.

  13. Temporal Gillespie Algorithm: Fast Simulation of Contagion Processes on Time-Varying Networks

    PubMed Central

    Vestergaard, Christian L.; Génois, Mathieu

    2015-01-01

    Stochastic simulations are one of the cornerstones of the analysis of dynamical processes on complex networks, and are often the only accessible way to explore their behavior. The development of fast algorithms is paramount to allow large-scale simulations. The Gillespie algorithm can be used for fast simulation of stochastic processes, and variants of it have been applied to simulate dynamical processes on static networks. However, its adaptation to temporal networks remains non-trivial. We here present a temporal Gillespie algorithm that solves this problem. Our method is applicable to general Poisson (constant-rate) processes on temporal networks, stochastically exact, and up to multiple orders of magnitude faster than traditional simulation schemes based on rejection sampling. We also show how it can be extended to simulate non-Markovian processes. The algorithm is easily applicable in practice, and as an illustration we detail how to simulate both Poissonian and non-Markovian models of epidemic spreading. Namely, we provide pseudocode and its implementation in C++ for simulating the paradigmatic Susceptible-Infected-Susceptible and Susceptible-Infected-Recovered models and a Susceptible-Infected-Recovered model with non-constant recovery rates. For empirical networks, the temporal Gillespie algorithm is here typically from 10 to 100 times faster than rejection sampling. PMID:26517860

  14. A fast and high performance multiple data integration algorithm for identifying human disease genes

    PubMed Central

    2015-01-01

    Background Integrating multiple data sources is indispensable in improving disease gene identification. It is not only due to the fact that disease genes associated with similar genetic diseases tend to lie close with each other in various biological networks, but also due to the fact that gene-disease associations are complex. Although various algorithms have been proposed to identify disease genes, their prediction performances and the computational time still should be further improved. Results In this study, we propose a fast and high performance multiple data integration algorithm for identifying human disease genes. A posterior probability of each candidate gene associated with individual diseases is calculated by using a Bayesian analysis method and a binary logistic regression model. Two prior probability estimation strategies and two feature vector construction methods are developed to test the performance of the proposed algorithm. Conclusions The proposed algorithm is not only generated predictions with high AUC scores, but also runs very fast. When only a single PPI network is employed, the AUC score is 0.769 by using F2 as feature vectors. The average running time for each leave-one-out experiment is only around 1.5 seconds. When three biological networks are integrated, the AUC score using F3 as feature vectors increases to 0.830, and the average running time for each leave-one-out experiment takes only about 12.54 seconds. It is better than many existing algorithms. PMID:26399620

  15. Temporal Gillespie Algorithm: Fast Simulation of Contagion Processes on Time-Varying Networks.

    PubMed

    Vestergaard, Christian L; Génois, Mathieu

    2015-10-01

    Stochastic simulations are one of the cornerstones of the analysis of dynamical processes on complex networks, and are often the only accessible way to explore their behavior. The development of fast algorithms is paramount to allow large-scale simulations. The Gillespie algorithm can be used for fast simulation of stochastic processes, and variants of it have been applied to simulate dynamical processes on static networks. However, its adaptation to temporal networks remains non-trivial. We here present a temporal Gillespie algorithm that solves this problem. Our method is applicable to general Poisson (constant-rate) processes on temporal networks, stochastically exact, and up to multiple orders of magnitude faster than traditional simulation schemes based on rejection sampling. We also show how it can be extended to simulate non-Markovian processes. The algorithm is easily applicable in practice, and as an illustration we detail how to simulate both Poissonian and non-Markovian models of epidemic spreading. Namely, we provide pseudocode and its implementation in C++ for simulating the paradigmatic Susceptible-Infected-Susceptible and Susceptible-Infected-Recovered models and a Susceptible-Infected-Recovered model with non-constant recovery rates. For empirical networks, the temporal Gillespie algorithm is here typically from 10 to 100 times faster than rejection sampling.

  16. Comparison of Two Wire Chamber Track Reconstruction Algorithms Used in Hall A at Jefferson Lab

    SciTech Connect

    Dobbs, S.; Hansen, J.O.

    2003-01-01

    The Hall A collaboration at Jefferson Lab is currently in the process of redesigning and rewriting its physics analysis software in C++, using the ROOT libraries developed at CERN, to replace the Fortran-based ESPACE analyzer. In this paper, we carry out a detailed comparison of the wire chamber tracking results of both software packages. To this end, reconstruction of target quantities from detected tracks through the Vertical Drift Chambers (VDCs) in both spectrometer arms has been recently added to the C++ analyzer, to bring it to the same level as ESPACE. A study of the differences in the outputs of both analysis programs shows that while the output of the C++ analyzer is suitable for calibrations and studies that do not require high resolution, there are still many subtle differences that need to be resolved before it is ready for a productionquality release. The problems are most likely due to different cluster matching and track fitting algorithms used by both programs for tracks through the VDCs, as well as certain corrections missing from the C++ code. These problems and some possible solutions are discussed.

  17. Mass tracking and material accounting in the Integral Fast Reactor (IFR)

    SciTech Connect

    Orechwa, Y.; Adams, C.H.; White, A.M.

    1991-01-01

    The Integral Fast Reactor (IFR) is a generic advanced liquid metal cooled reactor concept being developed at Argonne National Laboratory (ANL). There are a number of technical features of the IFR which contribute to its potential as a next-generation reactor. These are associated with large safety margins with regard to off-normal events involving the heat transport system, and the use of metallic fuel which makes possible the utilization of innovative fuel cycle processes. The latter feature permits fuel cycle closure the compact, low-cost reprocessing facilities, collocated with the reactor plant. These primary features are being demonstrated in the facilities at ANL-West, utilizing Experimental Breeder Reactor 2 and the associated Fuel Cycle Facility (FCF) as an IFR prototype. The demonstration of this IFR prototype includes the design and implementation of the Mass-Tracking System (MTG). In this system, data from the operations of the FCF, including weights and batch-process parameters, are collected and maintained by the MTG running on distributed workstations. The components of the MTG System include: (1) an Oracle database manager with a Fortran interface, (2) a set of MTG Tasks'' which collect, manipulate and report data, (3) a set of MTG Terminal Sessions'' which provide some interactive control of the Tasks, and (4) a set of servers which manage the Tasks and which provide the communications link between the MTG System and Operator Control Stations, which control process equipment and monitoring devices within the FCF.

  18. [Anxiety in patients undergoing fast-track knee arthroplasty in the light of recent literature].

    PubMed

    Ziętek, Paweł; Ziętek, Joanna; Szczypiór, Karina

    2014-01-01

    The rapid progress in knee implants technology and operational techniques go together with more and more modem medical programs, designed to optimize the patients' care and shorten their stay in hospital. However, this does not guarantee any elimination ofperioperative stress in patients. Anxiety is a negative emotional state arising from stressful circumstances accompanied by activation of the autonomous nervous system. Anxiety causes negative physiological changes, including wound healing, resistance to anesthetic induction, it is associated with an increased perioperative pain and prolong recovery period. The purpose of this work is to present the current state of knowledge on the preoperative anxiety and discuss its impact on pain and other parameters in patients undergoing fast-track arthroplasty of big joints. The work also shows selected issues of anxiety pathomechanism, and actual methods reducing preoperative anxiety in hospitalized patients. The common prevalence of anxiety in patients undergoing surgery induces the attempt to routinely identify patients with higher anxiety, which may be a predictive factor of worse results after TKA. Undertaking widely understood psychological support in these patients before and after the operation could be a favorable element, which would influence thefinal result of the treatment of patients after big joints arthroplasties.

  19. Pivotal role of ATP in macrophages fast tracking wound repair and regeneration.

    PubMed

    Kotwal, Girish J; Sarojini, Harshini; Chien, Sufan

    2015-09-01

    Chronic wounds occurring during aging or diabetes pose a significant burden to patients. The classical four-phase wound healing process has a 3-6 day lag before granulation starts to appear and it requires an intermediate step of activation of resident fibroblasts during the remodeling phase for production of collagen. This brief communication discusses published articles that demonstrate how the entire wound healing process can be fast tracked by intracellular ATP delivery, which triggers a novel pathway where alternatively activated macrophages play absolutely critical and central roles. This novel pathway involves an increase in proinflammatory cytokines (TNF, IL-1β, IL-6) and a chemokine (MCP-1) release. This is followed by activation of purinergic receptor (a family of plasma membrane receptors found in almost all mammalian cells), production of platelets and platelet microparticles, and activation of ATP-dependent chromatin remodeling enzymes. The end result is a massive influx and in situ proliferation of macrophages, increases in vascular endothelial growth factors that promote neovascularization, and most prominently, the direct production of collagen.

  20. A Fast Color Image Encryption Algorithm Using 4-Pixel Feistel Structure

    PubMed Central

    Yao, Wang; Wu, Faguo; Zhang, Xiao; Zheng, Zhiming; Wang, Zhao; Wang, Wenhua; Qiu, Wangjie

    2016-01-01

    Algorithms using 4-pixel Feistel structure and chaotic systems have been shown to resolve security problems caused by large data capacity and high correlation among pixels for color image encryption. In this paper, a fast color image encryption algorithm based on the modified 4-pixel Feistel structure and multiple chaotic maps is proposed to improve the efficiency of this type of algorithm. Two methods are used. First, a simple round function based on a piecewise linear function and tent map are used to reduce computational cost during each iteration. Second, the 4-pixel Feistel structure reduces round number by changing twist direction securely to help the algorithm proceed efficiently. While a large number of simulation experiments prove its security performance, additional special analysis and a corresponding speed simulation show that these two methods increase the speed of the proposed algorithm (0.15s for a 256*256 color image) to twice that of an algorithm with a similar structure (0.37s for the same size image). Additionally, the method is also faster than other recently proposed algorithms. PMID:27824894

  1. A Fast Color Image Encryption Algorithm Using 4-Pixel Feistel Structure.

    PubMed

    Yao, Wang; Wu, Faguo; Zhang, Xiao; Zheng, Zhiming; Wang, Zhao; Wang, Wenhua; Qiu, Wangjie

    2016-01-01

    Algorithms using 4-pixel Feistel structure and chaotic systems have been shown to resolve security problems caused by large data capacity and high correlation among pixels for color image encryption. In this paper, a fast color image encryption algorithm based on the modified 4-pixel Feistel structure and multiple chaotic maps is proposed to improve the efficiency of this type of algorithm. Two methods are used. First, a simple round function based on a piecewise linear function and tent map are used to reduce computational cost during each iteration. Second, the 4-pixel Feistel structure reduces round number by changing twist direction securely to help the algorithm proceed efficiently. While a large number of simulation experiments prove its security performance, additional special analysis and a corresponding speed simulation show that these two methods increase the speed of the proposed algorithm (0.15s for a 256*256 color image) to twice that of an algorithm with a similar structure (0.37s for the same size image). Additionally, the method is also faster than other recently proposed algorithms.

  2. A fast optimization algorithm for multicriteria intensity modulated proton therapy planning

    SciTech Connect

    Chen Wei; Craft, David; Madden, Thomas M.; Zhang, Kewu; Kooy, Hanne M.; Herman, Gabor T.

    2010-09-15

    Purpose: To describe a fast projection algorithm for optimizing intensity modulated proton therapy (IMPT) plans and to describe and demonstrate the use of this algorithm in multicriteria IMPT planning. Methods: The authors develop a projection-based solver for a class of convex optimization problems and apply it to IMPT treatment planning. The speed of the solver permits its use in multicriteria optimization, where several optimizations are performed which span the space of possible treatment plans. The authors describe a plan database generation procedure which is customized to the requirements of the solver. The optimality precision of the solver can be specified by the user. Results: The authors apply the algorithm to three clinical cases: A pancreas case, an esophagus case, and a tumor along the rib cage case. Detailed analysis of the pancreas case shows that the algorithm is orders of magnitude faster than industry-standard general purpose algorithms (MOSEK's interior point optimizer, primal simplex optimizer, and dual simplex optimizer). Additionally, the projection solver has almost no memory overhead. Conclusions: The speed and guaranteed accuracy of the algorithm make it suitable for use in multicriteria treatment planning, which requires the computation of several diverse treatment plans. Additionally, given the low memory overhead of the algorithm, the method can be extended to include multiple geometric instances and proton range possibilities, for robust optimization.

  3. Fast weighted K-view-voting algorithm for image texture classification

    NASA Astrophysics Data System (ADS)

    Liu, Hong; Lan, Yihua; Wang, Qian; Jin, Renchao; Song, Enmin; Hung, Chih-Cheng

    2012-02-01

    We propose an innovative and efficient approach to improve K-view-template (K-view-T) and K-view-datagram (K-view-D) algorithms for image texture classification. The proposed approach, called the weighted K-view-voting algorithm (K-view-V), uses a novel voting method for texture classification and an accelerating method based on the efficient summed square image (SSI) scheme as well as fast Fourier transform (FFT) to enable overall faster processing. Decision making, which assigns a pixel to a texture class, occurs by using our weighted voting method among the ``promising'' members in the neighborhood of a classified pixel. In other words, this neighborhood consists of all the views, and each view has a classified pixel in its territory. Experimental results on benchmark images, which are randomly taken from Brodatz Gallery and natural and medical images, show that this new classification algorithm gives higher classification accuracy than existing K-view algorithms. In particular, it improves the accurate classification of pixels near the texture boundary. In addition, the proposed acceleration method improves the processing speed of K-view-V as it requires much less computation time than other K-view algorithms. Compared with the results of earlier developed K-view algorithms and the gray level co-occurrence matrix (GLCM), the proposed algorithm is more robust, faster, and more accurate.

  4. SMG: Fast scalable greedy algorithm for influence maximization in social networks

    NASA Astrophysics Data System (ADS)

    Heidari, Mehdi; Asadpour, Masoud; Faili, Hesham

    2015-02-01

    Influence maximization is the problem of finding k most influential nodes in a social network. Many works have been done in two different categories, greedy approaches and heuristic approaches. The greedy approaches have better influence spread, but lower scalability on large networks. The heuristic approaches are scalable and fast but not for all type of networks. Improving the scalability of greedy approach is still an open and hot issue. In this work we present a fast greedy algorithm called State Machine Greedy that improves the existing algorithms by reducing calculations in two parts: (1) counting the traversing nodes in estimate propagation procedure, (2) Monte-Carlo graph construction in simulation of diffusion. The results show that our method makes a huge improvement in the speed over the existing greedy approaches.

  5. Fast maximum intensity projection algorithm using shear warp factorization and reduced resampling.

    PubMed

    Fang, Laifa; Wang, Yi; Qiu, Bensheng; Qian, Yuancheng

    2002-04-01

    Maximal intensity projection (MIP) is routinely used to view MRA and other volumetric angiographic data. The straightforward implementation of MIP is ray casting that traces a volumetric data set in a computationally expensive manner. This article reports a fast MIP algorithm using shear warp factorization and reduced resampling that drastically reduced the redundancy in the computations for projection, thereby speeding up MIP by more than 10 times.

  6. Fast algorithm of byte-to-byte wavelet transform for image compression applications

    NASA Astrophysics Data System (ADS)

    Pogrebnyak, Oleksiy B.; Sossa Azuela, Juan H.; Ramirez, Pablo M.

    2002-11-01

    A new fast algorithm of 2D DWT transform is presented. The algorithm operates on byte represented images and performs image transformation with the Cohen-Daubechies-Feauveau wavelet of the second order. It uses the lifting scheme for the calculations. The proposed algorithm is based on the "checkerboard" computation scheme for non-separable 2D wavelet. The problem of data extension near the image borders is resolved computing 1D Haar wavelet in the vicinity of the borders. With the checkerboard splitting, at each level of decomposition only one detail image is produced that simplify the further analysis for data compression. The calculations are rather simple, without any floating point operation allowing the implementation of the designed algorithm in fixed point DSP processors for fast, near real time processing. The proposed algorithm does not possesses perfect restoration of the processed data because of rounding that is introduced at each level of decomposition/restoration to perform operations with byte represented data. The designed algorithm was tested on different images. The criterion to estimate quantitatively the quality of the restored images was the well known PSNR. For the visual quality estimation the error maps between original and restored images were calculated. The obtained simulation results show that the visual and quantitative quality of the restored images is degraded with number of decomposition level increasing but is sufficiently high even after 6 levels. The introduced distortion are concentrated in the vicinity of high spatial activity details and are absent in the homogeneous regions. The designed algorithm can be used for image lossy compression and in noise suppression applications.

  7. Experimental investigation of a moving averaging algorithm for motion perpendicular to the leaf travel direction in dynamic MLC target tracking

    SciTech Connect

    Yoon, Jai-Woong; Sawant, Amit; Suh, Yelin; Cho, Byung-Chul; Suh, Tae-Suk; Keall, Paul

    2011-07-15

    Purpose: In dynamic multileaf collimator (MLC) motion tracking with complex intensity-modulated radiation therapy (IMRT) fields, target motion perpendicular to the MLC leaf travel direction can cause beam holds, which increase beam delivery time by up to a factor of 4. As a means to balance delivery efficiency and accuracy, a moving average algorithm was incorporated into a dynamic MLC motion tracking system (i.e., moving average tracking) to account for target motion perpendicular to the MLC leaf travel direction. The experimental investigation of the moving average algorithm compared with real-time tracking and no compensation beam delivery is described. Methods: The properties of the moving average algorithm were measured and compared with those of real-time tracking (dynamic MLC motion tracking accounting for both target motion parallel and perpendicular to the leaf travel direction) and no compensation beam delivery. The algorithm was investigated using a synthetic motion trace with a baseline drift and four patient-measured 3D tumor motion traces representing regular and irregular motions with varying baseline drifts. Each motion trace was reproduced by a moving platform. The delivery efficiency, geometric accuracy, and dosimetric accuracy were evaluated for conformal, step-and-shoot IMRT, and dynamic sliding window IMRT treatment plans using the synthetic and patient motion traces. The dosimetric accuracy was quantified via a {gamma}-test with a 3%/3 mm criterion. Results: The delivery efficiency ranged from 89 to 100% for moving average tracking, 26%-100% for real-time tracking, and 100% (by definition) for no compensation. The root-mean-square geometric error ranged from 3.2 to 4.0 mm for moving average tracking, 0.7-1.1 mm for real-time tracking, and 3.7-7.2 mm for no compensation. The percentage of dosimetric points failing the {gamma}-test ranged from 4 to 30% for moving average tracking, 0%-23% for real-time tracking, and 10%-47% for no compensation

  8. A Universal Fast Algorithm for Sensitivity-Based Structural Damage Detection

    PubMed Central

    Yang, Q. W.; Liu, J. K.; Li, C. H.; Liang, C. F.

    2013-01-01

    Structural damage detection using measured response data has emerged as a new research area in civil, mechanical, and aerospace engineering communities in recent years. In this paper, a universal fast algorithm is presented for sensitivity-based structural damage detection, which can quickly improve the calculation accuracy of the existing sensitivity-based technique without any high-order sensitivity analysis or multi-iterations. The key formula of the universal fast algorithm is derived from the stiffness and flexibility matrix spectral decomposition theory. With the introduction of the key formula, the proposed method is able to quickly achieve more accurate results than that obtained by the original sensitivity-based methods, regardless of whether the damage is small or large. Three examples are used to demonstrate the feasibility and superiority of the proposed method. It has been shown that the universal fast algorithm is simple to implement and quickly gains higher accuracy over the existing sensitivity-based damage detection methods. PMID:24453815

  9. Track-Before-Detect Algorithm for Faint Moving Objects based on Random Sampling and Consensus

    NASA Astrophysics Data System (ADS)

    Dao, P.; Rast, R.; Schlaegel, W.; Schmidt, V.; Dentamaro, A.

    2014-09-01

    There are many algorithms developed for tracking and detecting faint moving objects in congested backgrounds. One obvious application is detection of targets in images where each pixel corresponds to the received power in a particular location. In our application, a visible imager operated in stare mode observes geostationary objects as fixed, stars as moving and non-geostationary objects as drifting in the field of view. We would like to achieve high sensitivity detection of the drifters. The ability to improve SNR with track-before-detect (TBD) processing, where target information is collected and collated before the detection decision is made, allows respectable performance against dim moving objects. Generally, a TBD algorithm consists of a pre-processing stage that highlights potential targets and a temporal filtering stage. However, the algorithms that have been successfully demonstrated, e.g. Viterbi-based and Bayesian-based, demand formidable processing power and memory. We propose an algorithm that exploits the quasi constant velocity of objects, the predictability of the stellar clutter and the intrinsically low false alarm rate of detecting signature candidates in 3-D, based on an iterative method called "RANdom SAmple Consensus” and one that can run real-time on a typical PC. The technique is tailored for searching objects with small telescopes in stare mode. Our RANSAC-MT (Moving Target) algorithm estimates parameters of a mathematical model (e.g., linear motion) from a set of observed data which contains a significant number of outliers while identifying inliers. In the pre-processing phase, candidate blobs were selected based on morphology and an intensity threshold that would normally generate unacceptable level of false alarms. The RANSAC sampling rejects candidates that conform to the predictable motion of the stars. Data collected with a 17 inch telescope by AFRL/RH and a COTS lens/EM-CCD sensor by the AFRL/RD Satellite Assessment Center is

  10. A Real-Time Position-Locating Algorithm for CCD-Based Sunspot Tracking

    NASA Technical Reports Server (NTRS)

    Taylor, Jaime R.

    1996-01-01

    NASA Marshall Space Flight Center's (MSFC) EXperimental Vector Magnetograph (EXVM) polarimeter measures the sun's vector magnetic field. These measurements are taken to improve understanding of the sun's magnetic field in the hopes to better predict solar flares. Part of the procedure for the EXVM requires image motion stabilization over a period of a few minutes. A high speed tracker can be used to reduce image motion produced by wind loading on the EXVM, fluctuations in the atmosphere and other vibrations. The tracker consists of two elements, an image motion detector and a control system. The image motion detector determines the image movement from one frame to the next and sends an error signal to the control system. For the ground based application to reduce image motion due to atmospheric fluctuations requires an error determination at the rate of at least 100 hz. It would be desirable to have an error determination rate of 1 kHz to assure that higher rate image motion is reduced and to increase the control system stability. Two algorithms are presented that are typically used for tracking. These algorithms are examined for their applicability for tracking sunspots, specifically their accuracy if only one column and one row of CCD pixels are used. To examine the accuracy of this method two techniques are used. One involves moving a sunspot image a known distance with computer software, then applying the particular algorithm to see how accurately it determines this movement. The second technique involves using a rate table to control the object motion, then applying the algorithms to see how accurately each determines the actual motion. Results from these two techniques are presented.

  11. Fast and fully automatic phalanx segmentation using a grayscale-histogram morphology algorithm

    NASA Astrophysics Data System (ADS)

    Hsieh, Chi-Wen; Liu, Tzu-Chiang; Jong, Tai-Lang; Chen, Chih-Yen; Tiu, Chui-Mei; Chan, Din-Yuen

    2011-08-01

    Bone age assessment is a common radiological examination used in pediatrics to diagnose the discrepancy between the skeletal and chronological age of a child; therefore, it is beneficial to develop a computer-based bone age assessment to help junior pediatricians estimate bone age easily. Unfortunately, the phalanx on radiograms is not easily separated from the background and soft tissue. Therefore, we proposed a new method, called the grayscale-histogram morphology algorithm, to segment the phalanges fast and precisely. The algorithm includes three parts: a tri-stage sieve algorithm used to eliminate the background of hand radiograms, a centroid-edge dual scanning algorithm to frame the phalanx region, and finally a segmentation algorithm based on disk traverse-subtraction filter to segment the phalanx. Moreover, two more segmentation methods: adaptive two-mean and adaptive two-mean clustering were performed, and their results were compared with the segmentation algorithm based on disk traverse-subtraction filter using five indices comprising misclassification error, relative foreground area error, modified Hausdorff distances, edge mismatch, and region nonuniformity. In addition, the CPU time of the three segmentation methods was discussed. The result showed that our method had a better performance than the other two methods. Furthermore, satisfactory segmentation results were obtained with a low standard error.

  12. Fast Contour-Tracing Algorithm Based on a Pixel-Following Method for Image Sensors.

    PubMed

    Seo, Jonghoon; Chae, Seungho; Shim, Jinwook; Kim, Dongchul; Cheong, Cheolho; Han, Tack-Don

    2016-03-09

    Contour pixels distinguish objects from the background. Tracing and extracting contour pixels are widely used for smart/wearable image sensor devices, because these are simple and useful for detecting objects. In this paper, we present a novel contour-tracing algorithm for fast and accurate contour following. The proposed algorithm classifies the type of contour pixel, based on its local pattern. Then, it traces the next contour using the previous pixel's type. Therefore, it can classify the type of contour pixels as a straight line, inner corner, outer corner and inner-outer corner, and it can extract pixels of a specific contour type. Moreover, it can trace contour pixels rapidly because it can determine the local minimal path using the contour case. In addition, the proposed algorithm is capable of the compressing data of contour pixels using the representative points and inner-outer corner points, and it can accurately restore the contour image from the data. To compare the performance of the proposed algorithm to that of conventional techniques, we measure their processing time and accuracy. In the experimental results, the proposed algorithm shows better performance compared to the others. Furthermore, it can provide the compressed data of contour pixels and restore them accurately, including the inner-outer corner, which cannot be restored using conventional algorithms.

  13. Burst suppression probability algorithms: state-space methods for tracking EEG burst suppression

    NASA Astrophysics Data System (ADS)

    Chemali, Jessica; Ching, ShiNung; Purdon, Patrick L.; Solt, Ken; Brown, Emery N.

    2013-10-01

    Objective. Burst suppression is an electroencephalogram pattern in which bursts of electrical activity alternate with an isoelectric state. This pattern is commonly seen in states of severely reduced brain activity such as profound general anesthesia, anoxic brain injuries, hypothermia and certain developmental disorders. Devising accurate, reliable ways to quantify burst suppression is an important clinical and research problem. Although thresholding and segmentation algorithms readily identify burst suppression periods, analysis algorithms require long intervals of data to characterize burst suppression at a given time and provide no framework for statistical inference. Approach. We introduce the concept of the burst suppression probability (BSP) to define the brain's instantaneous propensity of being in the suppressed state. To conduct dynamic analyses of burst suppression we propose a state-space model in which the observation process is a binomial model and the state equation is a Gaussian random walk. We estimate the model using an approximate expectation maximization algorithm and illustrate its application in the analysis of rodent burst suppression recordings under general anesthesia and a patient during induction of controlled hypothermia. Main result. The BSP algorithms track burst suppression on a second-to-second time scale, and make possible formal statistical comparisons of burst suppression at different times. Significance. The state-space approach suggests a principled and informative way to analyze burst suppression that can be used to monitor, and eventually to control, the brain states of patients in the operating room and in the intensive care unit.

  14. How Fast Is Your Body Motion? Determining a Sufficient Frame Rate for an Optical Motion Tracking System Using Passive Markers.

    PubMed

    Song, Min-Ho; Godøy, Rolf Inge

    2016-01-01

    This paper addresses how to determine a sufficient frame (sampling) rate for an optical motion tracking system using passive reflective markers. When using passive markers for the optical motion tracking, avoiding identity confusion between the markers becomes a problem as the speed of motion increases, necessitating a higher frame rate to avoid a failure of the motion tracking caused by marker confusions and/or dropouts. Initially, one might believe that the Nyquist-Shannon sampling rate estimated from the assumed maximal temporal variation of a motion (i.e. a sampling rate at least twice that of the maximum motion frequency) could be the complete solution to the problem. However, this paper shows that also the spatial distance between the markers should be taken into account in determining the suitable frame rate of an optical motion tracking with passive markers. In this paper, a frame rate criterion for the optical tracking using passive markers is theoretically derived and also experimentally verified using a high-quality optical motion tracking system. Both the theoretical and the experimental results showed that the minimum frame rate is proportional to the ratio between the maximum speed of the motion and the minimum spacing between markers, and may also be predicted precisely if the proportional constant is known in advance. The inverse of the proportional constant is here defined as the tracking efficiency constant and it can be easily determined with some test measurements. Moreover, this newly defined constant can provide a new way of evaluating the tracking algorithm performance of an optical tracking system.

  15. How Fast Is Your Body Motion? Determining a Sufficient Frame Rate for an Optical Motion Tracking System Using Passive Markers

    PubMed Central

    Song, Min-Ho; Godøy, Rolf Inge

    2016-01-01

    This paper addresses how to determine a sufficient frame (sampling) rate for an optical motion tracking system using passive reflective markers. When using passive markers for the optical motion tracking, avoiding identity confusion between the markers becomes a problem as the speed of motion increases, necessitating a higher frame rate to avoid a failure of the motion tracking caused by marker confusions and/or dropouts. Initially, one might believe that the Nyquist-Shannon sampling rate estimated from the assumed maximal temporal variation of a motion (i.e. a sampling rate at least twice that of the maximum motion frequency) could be the complete solution to the problem. However, this paper shows that also the spatial distance between the markers should be taken into account in determining the suitable frame rate of an optical motion tracking with passive markers. In this paper, a frame rate criterion for the optical tracking using passive markers is theoretically derived and also experimentally verified using a high-quality optical motion tracking system. Both the theoretical and the experimental results showed that the minimum frame rate is proportional to the ratio between the maximum speed of the motion and the minimum spacing between markers, and may also be predicted precisely if the proportional constant is known in advance. The inverse of the proportional constant is here defined as the tracking efficiency constant and it can be easily determined with some test measurements. Moreover, this newly defined constant can provide a new way of evaluating the tracking algorithm performance of an optical tracking system. PMID:26967900

  16. Traditional healers and the "Fast-Track" HIV response: is success possible without them?

    PubMed

    Leclerc-Madlala, Suzanne; Green, Edward; Hallin, Mary

    2016-07-01

    The rapid scale-up of effective HIV prevention strategies is a central theme of the post-2015 health and development agenda. All major global HIV and AIDS funders have aligned their policies and plans to achieve sharp reductions in new HIV infections and reach epidemic control by 2030. In these "fast-track" plans, increased antiretroviral treatment coverage and the attainment of viral suppression are pivotal, and there is firm recognition of the need for countries to mobilise more domestic resources and build stronger community clinic systems. There is little in these bold plans, however, to suggest that the now 30-year-old call by the World Health Organization (WHO) and other organisations to establish systematic collaborations with the traditional health sector will finally be heeded. In the context of sub-Saharan Africa's HIV epidemic, a significant body of literature demonstrates the critical role that traditional healers can play in improving the success of health programmes, including those for HIV prevention. This paper provides a brief history of collaboration with traditional healers for HIV followed by a description of several successful collaborations and discussion of key elements for success. We argue that the traditional health sector is a major resource that has yet to be sufficiently mobilised against HIV. As we shift from a short-term HIV response to a longer-term and more sustainable response, there is an urgent need to accelerate efforts to leverage and partner with the hundreds of thousands of traditional health practitioners who are already providing health services in communities. Failure to better attune our work to the medical pluralism of communities affected by HIV will continue to hinder HIV programming success and help assure that ambitious post-2015 HIV prevention and control goals are not realised.

  17. A fusion nuclear science facility for a fast-track path to DEMO

    DOE PAGES

    Garofalo, A. M.; Abdou, M. A.; Canik, John M.; ...

    2014-04-24

    An accelerated fusion energy development program, a fast-track approach, requires proceeding with a nuclear and materials testing program in parallel with research on burning plasmas, ITER. A Fusion Nuclear Science Facility (FNSF) would address many of the key issues that need to be addressed prior to DEMO, including breeding tritium and completing the fuel cycle, qualifying nuclear materials for high fluence, developing suitable materials for the plasma-boundary interface, and demonstrating power extraction. The Advanced Tokamak (AT) is a strong candidate for an FNSF as a consequence of its mature physics base, capability to address the key issues, and the directmore » relevance to an attractive target power plant. The standard aspect ratio provides space for a solenoid, assuring robust plasma current initiation,and for an inboard blanket, assuring robust tritium breeding ratio (TBR) >1 for FNSF tritium self-sufficiency and building of inventory needed to start up DEMO. An example design point gives a moderate sized Cu-coil device with R/a = 2.7 m/0.77 κ = 2.3, BT= 5.4 T, IP = 6.6 MA, βN = 2.75, Pfus = 127 MW. The modest bootstrap fraction of fBS = 0.55 provides an opportunity to develop steady state with sufficient current drive for adequate control. Lastly, proceeding with a FNSF in parallel with ITER provides a strong basis to begin construction of DEMO upon the achievement of Q ~ 10 in ITER.« less

  18. A fusion nuclear science facility for a fast-track path to DEMO

    SciTech Connect

    Garofalo, A. M.; Abdou, M. A.; Canik, John M.; Chan, Vincent S.; Hyatt, A. W.; Hill, D. N.; Morley, N. B.; Navratil, G. A.; Sawan, M. E.; Taylor, T. S.; Wong, C. P. C.; Wu, W.; Ying, Alice

    2014-04-24

    An accelerated fusion energy development program, a fast-track approach, requires proceeding with a nuclear and materials testing program in parallel with research on burning plasmas, ITER. A Fusion Nuclear Science Facility (FNSF) would address many of the key issues that need to be addressed prior to DEMO, including breeding tritium and completing the fuel cycle, qualifying nuclear materials for high fluence, developing suitable materials for the plasma-boundary interface, and demonstrating power extraction. The Advanced Tokamak (AT) is a strong candidate for an FNSF as a consequence of its mature physics base, capability to address the key issues, and the direct relevance to an attractive target power plant. The standard aspect ratio provides space for a solenoid, assuring robust plasma current initiation,and for an inboard blanket, assuring robust tritium breeding ratio (TBR) >1 for FNSF tritium self-sufficiency and building of inventory needed to start up DEMO. An example design point gives a moderate sized Cu-coil device with R/a = 2.7 m/0.77 κ = 2.3, BT= 5.4 T, IP = 6.6 MA, βN = 2.75, Pfus = 127 MW. The modest bootstrap fraction of fBS = 0.55 provides an opportunity to develop steady state with sufficient current drive for adequate control. Lastly, proceeding with a FNSF in parallel with ITER provides a strong basis to begin construction of DEMO upon the achievement of Q ~ 10 in ITER.

  19. Study of cluster reconstruction and track fitting algorithms for CGEM-IT at BESIII

    NASA Astrophysics Data System (ADS)

    Guo, Yue; Wang, Liang-Liang; Ju, Xu-Dong; Wu, Ling-Hui; Xiu, Qing-Lei; Wang, Hai-Xia; Dong, Ming-Yi; Hu, Jing-Ran; Li, Wei-Dong; Li, Wei-Guo; Liu, Huai-Min; Qun, Ou-Yang; Shen, Xiao-Yan; Yuan, Ye; Zhang, Yao

    2016-01-01

    Considering the effects of aging on the existing Inner Drift Chamber (IDC) of BESIII, a GEM-based inner tracker, the Cylindrical-GEM Inner Tracker (CGEM-IT), is proposed to be designed and constructed as an upgrade candidate for the IDC. This paper introduces a full simulation package for the CGEM-IT with a simplified digitization model, and describes the development of software for cluster reconstruction and track fitting, using a track fitting algorithm based on the Kalman filter method. Preliminary results for the reconstruction algorithms which are obtained using a Monte Carlo sample of single muon events in the CGEM-IT, show that the CGEM-IT has comparable momentum resolution and transverse vertex resolution to the IDC, and a better z-direction resolution than the IDC. Supported by National Key Basic Research Program of China (2015CB856700), National Natural Science Foundation of China (11205184, 11205182) and Joint Funds of National Natural Science Foundation of China (U1232201)

  20. Nonlinear estimation algorithm and its optical implementation for target tracking in clutter environment

    NASA Astrophysics Data System (ADS)

    Chun, Joohwan; Kailath, Thomas; Son, Jung-Young

    2000-03-01

    The systems such as infrared search and trackers (IRST's), forward looking infrared systems (FLIR's), sonars, and 2-D radars consist of two functional blocks; a detection unit and a tracker. The detection unit which has matched filters followed by a threshold device generates a set of multiple two-dimensional points or detects at every sampling time. For a radar or sonar, each generated detect has polar coordinates, the range and azimuth while an IRST or FLIR produces detects in cartesian coordinates. In practice, the detection unit always has a non-zero false alarm rate, and therefore, the set of detects usually contains clutter points as well as the target. In this paper, we shall present a new target tracking algorithm for clutter environment applicable to a wide range of tracking systems. More specifically, the two-dimensional tracking problem in clutter environment is solved in the discrete-time Bayes optimal (nonlinear, and non-Gaussian) estimation framework. The proposed method recursively finds the entire probability density functions of the target position and velocity. With our approach, the nonlinear estimation problem is converted into simpler linear convolution operations, which can efficiently be implemented with optical devices such as lenses, CCD's (charge coupled devices), SLM's (spatial light modulators) and films.

  1. Assessing the performance of vessel wall tracking algorithms: the importance of the test phantom

    NASA Astrophysics Data System (ADS)

    Ramnarine, K. V.; Kanber, B.; Panerai, R. B.

    2004-01-01

    There is widespread clinical interest in assessing the mechanical properties of tissues and vessel walls. This study investigated the importance of the test phantom in providing a realistic assessment of clinical wall tracking performance for a variety of ultrasound modalities. B-mode, colour Doppler and Tissue Doppler Imaging (TDI) cineloop images were acquired using a Philips HDI5000 scanner and L12-5 probe. In-vivo longitudinal sections of 30 common carotid arteries and in-vitro images of pulsatile flow of a blood mimicking fluid through walled and wall-less tissue and vessel mimicking flow phantoms were analysed. Vessel wall tracking performance was assessed for our new probabilistic B-mode algorithm (PROBAL), and 3 different techniques implemented by Philips Medical Systems, based on B-mode edge detection (LDOT), colour Doppler (CVIQ) and TDI (TDIAWM). Precision (standard deviation/mean) of the peak systole dilations for respective PROBAL, LDOT, CVIQ and TDIAWM techniques were: 15.4 +/- 8.4%, 23 +/- 12.7%, 10 +/- 10% and 10.3 +/- 8.1% for the common carotid arteries; 6.4%, 22%, 11.6% and 34.5% for the wall-less flow phantom, 5.3%, 9.8%, 23.4% and 2.7% for the C-flex walled phantom and 3.9%, 2.6%, 1% and 3.2% for the latex walled phantom. The test phantom design and construction had a significant effect on the measurement of wall tracking performance.

  2. Designs and Algorithms to Map Eye Tracking Data with Dynamic Multielement Moving Objects

    PubMed Central

    Mandal, Saptarshi

    2016-01-01

    Design concepts and algorithms were developed to address the eye tracking analysis issues that arise when (1) participants interrogate dynamic multielement objects that can overlap on the display and (2) visual angle error of the eye trackers is incapable of providing exact eye fixation coordinates. These issues were addressed by (1) developing dynamic areas of interests (AOIs) in the form of either convex or rectangular shapes to represent the moving and shape-changing multielement objects, (2) introducing the concept of AOI gap tolerance (AGT) that controls the size of the AOIs to address the overlapping and visual angle error issues, and (3) finding a near optimal AGT value. The approach was tested in the context of air traffic control (ATC) operations where air traffic controller specialists (ATCSs) interrogated multiple moving aircraft on a radar display to detect and control the aircraft for the purpose of maintaining safe and expeditious air transportation. In addition, we show how eye tracking analysis results can differ based on how we define dynamic AOIs to determine eye fixations on moving objects. The results serve as a framework to more accurately analyze eye tracking data and to better support the analysis of human performance. PMID:27725830

  3. Mechanics of swimming of multi-body bacterial swarmers using non-labeled cell tracking algorithm

    NASA Astrophysics Data System (ADS)

    Phuyal, Kiran; Kim, Min Jun

    2013-01-01

    To better understand the survival strategy of bacterial swarmers and the mechanical advantages offered by the linear chain (head-tail) attachment of the multiple bacterial bodies in an individual swarmer cell at low Reynolds number, a non-labeled cell tracking algorithm was used to quantify the mechanics of multi-body flagellated bacteria, Serratia marcescens, swimming in a motility buffer that originally exhibited the swarming motility. Swarming is a type of bacterial motility that is characterized by the collective coordinated motion of differentiated swarmer cells on a two-dimensional surface such as agar. In this study, the bacterial swarmers with multiple cell bodies (2, 3, and 4) were extracted from the swarm plate, and then tracked individually after resuspending in the motility medium. Their motion was investigated and compared with individual undifferentiated swimming bacterial cells. The swarmers when released into the motility buffer swam actively without tumbles. Their speeds, orientations, and the diffusive properties were studied by tracking the individual cell trajectories over a short distance in two-dimensional field when the cells are swimming at a constant depth in a bulk aqueous environment. At short time scales, the ballistic trajectory was dominant for both multi-body swarmers and undifferentiated cells.

  4. A comparative study of automatic image segmentation algorithms for target tracking in MR-IGRT.

    PubMed

    Feng, Yuan; Kawrakow, Iwan; Olsen, Jeff; Parikh, Parag J; Noel, Camille; Wooten, Omar; Du, Dongsu; Mutic, Sasa; Hu, Yanle

    2016-03-08

    On-board magnetic resonance (MR) image guidance during radiation therapy offers the potential for more accurate treatment delivery. To utilize the real-time image information, a crucial prerequisite is the ability to successfully segment and track regions of interest (ROI). The purpose of this work is to evaluate the performance of different segmentation algorithms using motion images (4 frames per second) acquired using a MR image-guided radiotherapy (MR-IGRT) system. Manual con-tours of the kidney, bladder, duodenum, and a liver tumor by an experienced radiation oncologist were used as the ground truth for performance evaluation. Besides the manual segmentation, images were automatically segmented using thresholding, fuzzy k-means (FKM), k-harmonic means (KHM), and reaction-diffusion level set evolution (RD-LSE) algorithms, as well as the tissue tracking algorithm provided by the ViewRay treatment planning and delivery system (VR-TPDS). The performance of the five algorithms was evaluated quantitatively by comparing with the manual segmentation using the Dice coefficient and target registration error (TRE) measured as the distance between the centroid of the manual ROI and the centroid of the automatically segmented ROI. All methods were able to successfully segment the bladder and the kidney, but only FKM, KHM, and VR-TPDS were able to segment the liver tumor and the duodenum. The performance of the thresholding, FKM, KHM, and RD-LSE algorithms degraded as the local image contrast decreased, whereas the performance of the VP-TPDS method was nearly independent of local image contrast due to the reference registration algorithm. For segmenting high-contrast images (i.e., kidney), the thresholding method provided the best speed (< 1 ms) with a satisfying accuracy (Dice = 0.95). When the image contrast was low, the VR-TPDS method had the best automatic contour. Results suggest an image quality determination procedure before segmentation and a combination of

  5. Fast-track rapid warfarin reversal for elective surgery: extending the efficacy profile to high-risk patients with cancer.

    PubMed

    Byrne, T J; Riedel, B; Ismail, H M; Heriot, A; Dauer, R; Westerman, D; Seymour, J F; Kenchington, K; Burbury, K

    2015-11-01

    Periprocedural management of patients on long-term warfarin therapy remains a common and important clinical issue, with little high-quality data to guide this complex process. The current accepted practice is cessation of warfarin five days preoperatively, but this is not without risk and can be complicated, particularly if bridging is required. An alternative method utilising low-dose intravenous vitamin K the day before surgery has been shown previously to be efficacious, safe and convenient in an elective surgical population receiving chronic warfarin therapy. The efficacy and utility of this 'fast-track' warfarin reversal protocol in surgical patients with cancer, who were at high risk of both thromboembolism and bleeding was investigated in a prospective, single-arm study at a dedicated cancer centre. Seventy-one patients underwent 82 episodes of fast-track warfarin reversal (3 mg intravenous vitamin K 18 to 24 hours before surgery). No patient suffered an adverse reaction to intravenous vitamin K, all but one achieved an International Normalized Ratio =1.5 on the day of surgery, and no surgery was deferred. Assays of vitamin K-dependent factor levels pre- and post-vitamin K demonstrated restoration of functional activity to within an acceptable range for surgical haemostasis. While this alternative method requires further validation in a larger prospective randomised study, we have now extended our use of fast-track warfarin reversal using vitamin K to patients with cancer, on the basis of our experience of its safety, convenience, reliability and efficacy.

  6. The Implementation of the Fast Track Program: An Example of a Large-Scale Prevention Science Efficacy Trial

    PubMed Central

    2009-01-01

    In 1990, the Fast Track Project was initiated to evaluate the feasibility and effectiveness of a comprehensive, multicomponent prevention program targeting children at risk for conduct disorders in four demographically diverse American communities (Conduct Problems Prevention Research Group [CPPRG], 1992). Representing a prevention science approach toward community-based preventive intervention, the Fast Track intervention design was based upon the available data base elucidating the epidemiology of risk for conduct disorder and suggesting key causal developmental influences (R. P. Weissberg & M. T. Greenberg, 1998). Critical questions about this approach to prevention center around the extent to which such a science-based program can be effective at (1) engaging community members and stakeholders, (2) maintaining intervention fidelity while responding appropriately to the local norms and needs of communities that vary widely in their demographic and cultural/ethnic composition, and (3) maintaining community engagement in the long-term to support effective and sustainable intervention dissemination. This paper discusses these issues, providing examples from the Fast Track project to illustrate the process of program implementation and the evidence available regarding the success of this science-based program at engaging communities in sustainable and effective ways as partners in prevention programming. PMID:11930968

  7. Error analysis and algorithm implementation for an improved optical-electric tracking device based on MEMS

    NASA Astrophysics Data System (ADS)

    Sun, Hong; Wu, Qian-zhong

    2013-09-01

    In order to improve the precision of optical-electric tracking device, proposing a kind of improved optical-electric tracking device based on MEMS, in allusion to the tracking error of gyroscope senor and the random drift, According to the principles of time series analysis of random sequence, establish AR model of gyro random error based on Kalman filter algorithm, then the output signals of gyro are multiple filtered with Kalman filter. And use ARM as micro controller servo motor is controlled by fuzzy PID full closed loop control algorithm, and add advanced correction and feed-forward links to improve response lag of angle input, Free-forward can make output perfectly follow input. The function of lead compensation link is to shorten the response of input signals, so as to reduce errors. Use the wireless video monitor module and remote monitoring software (Visual Basic 6.0) to monitor servo motor state in real time, the video monitor module gathers video signals, and the wireless video module will sent these signals to upper computer, so that show the motor running state in the window of Visual Basic 6.0. At the same time, take a detailed analysis to the main error source. Through the quantitative analysis of the errors from bandwidth and gyro sensor, it makes the proportion of each error in the whole error more intuitive, consequently, decrease the error of the system. Through the simulation and experiment results shows the system has good following characteristic, and it is very valuable for engineering application.

  8. Evaluation of Real-Time Hand Motion Tracking Using a Range Camera and the Mean-Shift Algorithm

    NASA Astrophysics Data System (ADS)

    Lahamy, H.; Lichti, D.

    2011-09-01

    Several sensors have been tested for improving the interaction between humans and machines including traditional web cameras, special gloves, haptic devices, cameras providing stereo pairs of images and range cameras. Meanwhile, several methods are described in the literature for tracking hand motion: the Kalman filter, the mean-shift algorithm and the condensation algorithm. In this research, the combination of a range camera and the simple version of the mean-shift algorithm has been evaluated for its capability for hand motion tracking. The evaluation was assessed in terms of position accuracy of the tracking trajectory in x, y and z directions in the camera space and the time difference between image acquisition and image display. Three parameters have been analyzed regarding their influence on the tracking process: the speed of the hand movement, the distance between the camera and the hand and finally the integration time of the camera. Prior to the evaluation, the required warm-up time of the camera has been measured. This study has demonstrated the suitability of the range camera used in combination with the mean-shift algorithm for real-time hand motion tracking but for very high speed hand movement in the traverse plane with respect to the camera, the tracking accuracy is low and requires improvement.

  9. Improvements in fast-response flood modeling: desktop parallel computing and domain tracking

    SciTech Connect

    Judi, David R; Mcpherson, Timothy N; Burian, Steven J

    2009-01-01

    It is becoming increasingly important to have the ability to accurately forecast flooding, as flooding accounts for the most losses due to natural disasters in the world and the United States. Flood inundation modeling has been dominated by one-dimensional approaches. These models are computationally efficient and are considered by many engineers to produce reasonably accurate water surface profiles. However, because the profiles estimated in these models must be superimposed on digital elevation data to create a two-dimensional map, the result may be sensitive to the ability of the elevation data to capture relevant features (e.g. dikes/levees, roads, walls, etc...). Moreover, one-dimensional models do not explicitly represent the complex flow processes present in floodplains and urban environments and because two-dimensional models based on the shallow water equations have significantly greater ability to determine flow velocity and direction, the National Research Council (NRC) has recommended that two-dimensional models be used over one-dimensional models for flood inundation studies. This paper has shown that two-dimensional flood modeling computational time can be greatly reduced through the use of Java multithreading on multi-core computers which effectively provides a means for parallel computing on a desktop computer. In addition, this paper has shown that when desktop parallel computing is coupled with a domain tracking algorithm, significant computation time can be eliminated when computations are completed only on inundated cells. The drastic reduction in computational time shown here enhances the ability of two-dimensional flood inundation models to be used as a near-real time flood forecasting tool, engineering, design tool, or planning tool. Perhaps even of greater significance, the reduction in computation time makes the incorporation of risk and uncertainty/ensemble forecasting more feasible for flood inundation modeling (NRC 2000; Sayers et al

  10. Involuntary motion tracking for medical dynamic infrared thermography using a template-based algorithm

    PubMed Central

    Herman, Cila

    2013-01-01

    In medical applications, Dynamic Infrared (IR) Thermography is used to detect the temporal variation of the skin temperature. Dynamic Infrared Imaging first introduces a thermal challenge such as cooling on the human skin, and then a sequence of hundreds of consecutive frames is acquired after the removal of the thermal challenge. As a result, by analyzing the temporal variation of the skin temperature over the image sequence, the thermal signature of skin abnormality can be examined. However, during the acquisition of dynamic IR imaging, the involuntary movements of patients are unavoidable, and such movements will undermine the accuracy of diagnosis. In this study, based on the template-based algorithm, a tracking approach is proposed to compensate the motion artifact. The affine warping model is adopted to estimate the motion parameter of the image template, and then the Lucas-Kanade algorithm is applied to search for the optimized parameters of the warping function. In addition, the weighting mask is also incorporated in the computation to ensure the robustness of the algorithm. To evaluate the performance of the approach, two sets of IR image sequences of a subject’s hand are analyzed: the steady-state image sequence, in which the skin temperature is in equilibrium with the environment, and the thermal recovery image sequence, which is acquired after cooling is applied on the skin for 60 seconds. By selecting the target region in the first frame as the template, satisfactory tracking results were obtained in both experimental trials, and the robustness of the approach can be effectively ensured in the recovery trial. PMID:24392205

  11. Fast Fourier transform based direct integration algorithm for the linear canonical transform

    NASA Astrophysics Data System (ADS)

    Wang, Dayong; Liu, Changgeng; Wang, Yunxin; Zhao, Jie

    2011-03-01

    The linear canonical transform(LCT) is a parameterized linear integral transform, which is the general case of many well-known transforms such as the Fourier transform(FT), the fractional Fourier transform(FRT) and the Fresnel transform(FST). These integral transforms are of great importance in wave propagation problems because they are the solutions of the wave equation under a variety of circumstances. In optics, the LCT can be used to model paraxial free space propagation and other quadratic phase systems such as lens and graded-index media. A number of algorithms have been presented to fast compute the LCT. When they are used to compute the LCT, the sampling period in the transform domain is dependent on that in the signal domain. This drawback limits their applicability in some cases such as color digital holography. In this paper, a Fast-Fourier-Transform-based Direct Integration algorithm(FFT-DI) for the LCT is presented. The FFT-DI is a fast computational method of the Direct Integration(DI) for the LCT. It removes the dependency of the sampling period in the transform domain on that in the signal domain. Simulations and experimental results are presented to validate this idea.

  12. Fast Fourier transform based direct integration algorithm for the linear canonical transform

    NASA Astrophysics Data System (ADS)

    Wang, Dayong; Liu, Changgeng; Wang, Yunxin; Zhao, Jie

    2010-07-01

    The linear canonical transform(LCT) is a parameterized linear integral transform, which is the general case of many well-known transforms such as the Fourier transform(FT), the fractional Fourier transform(FRT) and the Fresnel transform(FST). These integral transforms are of great importance in wave propagation problems because they are the solutions of the wave equation under a variety of circumstances. In optics, the LCT can be used to model paraxial free space propagation and other quadratic phase systems such as lens and graded-index media. A number of algorithms have been presented to fast compute the LCT. When they are used to compute the LCT, the sampling period in the transform domain is dependent on that in the signal domain. This drawback limits their applicability in some cases such as color digital holography. In this paper, a Fast-Fourier-Transform-based Direct Integration algorithm(FFT-DI) for the LCT is presented. The FFT-DI is a fast computational method of the Direct Integration(DI) for the LCT. It removes the dependency of the sampling period in the transform domain on that in the signal domain. Simulations and experimental results are presented to validate this idea.

  13. Statistical iterative reconstruction using fast optimization transfer algorithm with successively increasing factor in Digital Breast Tomosynthesis

    NASA Astrophysics Data System (ADS)

    Xu, Shiyu; Zhang, Zhenxi; Chen, Ying

    2014-03-01

    Statistical iterative reconstruction exhibits particularly promising since it provides the flexibility of accurate physical noise modeling and geometric system description in transmission tomography system. However, to solve the objective function is computationally intensive compared to analytical reconstruction methods due to multiple iterations needed for convergence and each iteration involving forward/back-projections by using a complex geometric system model. Optimization transfer (OT) is a general algorithm converting a high dimensional optimization to a parallel 1-D update. OT-based algorithm provides a monotonic convergence and a parallel computing framework but slower convergence rate especially around the global optimal. Based on an indirect estimation on the spectrum of the OT convergence rate matrix, we proposed a successively increasing factor- scaled optimization transfer (OT) algorithm to seek an optimal step size for a faster rate. Compared to a representative OT based method such as separable parabolic surrogate with pre-computed curvature (PC-SPS), our algorithm provides comparable image quality (IQ) with fewer iterations. Each iteration retains a similar computational cost to PC-SPS. The initial experiment with a simulated Digital Breast Tomosynthesis (DBT) system shows that a total 40% computing time is saved by the proposed algorithm. In general, the successively increasing factor-scaled OT exhibits a tremendous potential to be a iterative method with a parallel computation, a monotonic and global convergence with fast rate.

  14. Fast automated yeast cell counting algorithm using bright-field and fluorescence microscopic images

    PubMed Central

    2013-01-01

    Background The faithful determination of the concentration and viability of yeast cells is important for biological research as well as industry. To this end, it is important to develop an automated cell counting algorithm that can provide not only fast but also accurate and precise measurement of yeast cells. Results With the proposed method, we measured the precision of yeast cell measurements by using 0%, 25%, 50%, 75% and 100% viability samples. As a result, the actual viability measured with the proposed yeast cell counting algorithm is significantly correlated to the theoretical viability (R2 = 0.9991). Furthermore, we evaluated the performance of our algorithm in various computing platforms. The results showed that the proposed algorithm could be feasible to use with low-end computing platforms without loss of its performance. Conclusions Our yeast cell counting algorithm can rapidly provide the total number and the viability of yeast cells with exceptional accuracy and precision. Therefore, we believe that our method can become beneficial for a wide variety of academic field and industries such as biotechnology, pharmaceutical and alcohol production. PMID:24215650

  15. Fast algorithm for scaling analysis with higher-order detrending moving average method

    NASA Astrophysics Data System (ADS)

    Tsujimoto, Yutaka; Miki, Yuki; Shimatani, Satoshi; Kiyono, Ken

    2016-05-01

    Among scaling analysis methods based on the root-mean-square deviation from the estimated trend, it has been demonstrated that centered detrending moving average (DMA) analysis with a simple moving average has good performance when characterizing long-range correlation or fractal scaling behavior. Furthermore, higher-order DMA has also been proposed; it is shown to have better detrending capabilities, removing higher-order polynomial trends than original DMA. However, a straightforward implementation of higher-order DMA requires a very high computational cost, which would prevent practical use of this method. To solve this issue, in this study, we introduce a fast algorithm for higher-order DMA, which consists of two techniques: (1) parallel translation of moving averaging windows by a fixed interval; (2) recurrence formulas for the calculation of summations. Our algorithm can significantly reduce computational cost. Monte Carlo experiments show that the computational time of our algorithm is approximately proportional to the data length, although that of the conventional algorithm is proportional to the square of the data length. The efficiency of our algorithm is also shown by a systematic study of the performance of higher-order DMA, such as the range of detectable scaling exponents and detrending capability for removing polynomial trends. In addition, through the analysis of heart-rate variability time series, we discuss possible applications of higher-order DMA.

  16. A fast rank-reduction algorithm for three-dimensional seismic data interpolation

    NASA Astrophysics Data System (ADS)

    Jia, Yongna; Yu, Siwei; Liu, Lina; Ma, Jianwei

    2016-09-01

    Rank-reduction methods have been successfully used for seismic data interpolation and noise attenuation. However, highly intense computation is required for singular value decomposition (SVD) in most rank-reduction methods. In this paper, we propose a simple yet efficient interpolation algorithm, which is based on the Hankel matrix, for randomly missing traces. Following the multichannel singular spectrum analysis (MSSA) technique, we first transform the seismic data into a low-rank block Hankel matrix for each frequency slice. Then, a fast orthogonal rank-one matrix pursuit (OR1MP) algorithm is employed to minimize the low-rank constraint of the block Hankel matrix. In the new algorithm, only the left and right top singular vectors are needed to be computed, thereby, avoiding the complexity of computation required for SVD. Thus, we improve the calculation efficiency significantly. Finally, we anti-average the rank-reduction block Hankel matrix and obtain the reconstructed data in the frequency domain. Numerical experiments on 3D seismic data show that the proposed interpolation algorithm provides much better performance than the traditional MSSA algorithm in computational speed, especially for large-scale data processing.

  17. A Fast Sphere Decoding Algorithm for Space-Frequency Block Codes

    NASA Astrophysics Data System (ADS)

    Safar, Zoltan; Su, Weifeng; Liu, K. J. Ray

    2006-12-01

    The recently proposed space-frequency-coded MIMO-OFDM systems have promised considerable performance improvement over single-antenna systems. However, in order to make multiantenna OFDM systems an attractive choice for practical applications, implementation issues such as decoding complexity must be addressed successfully. In this paper, we propose a computationally efficient decoding algorithm for space-frequency block codes. The central part of the algorithm is a modulation-independent sphere decoding framework formulated in the complex domain. We develop three decoding approaches: a modulation-independent approach applicable to any memoryless modulation method, a QAM-specific and a PSK-specific fast decoding algorithm performing nearest-neighbor signal point search. The computational complexity of the algorithms is investigated via both analysis and simulation. The simulation results demonstrate that the proposed algorithm can significantly reduce the decoding complexity. We observe up to 75% reduction in the required FLOP count per code block compared to previously existing methods without noticeable performance degradation.

  18. Fast dose algorithm for generation of dose coverage probability for robustness analysis of fractionated radiotherapy

    NASA Astrophysics Data System (ADS)

    Tilly, David; Ahnesjö, Anders

    2015-07-01

    A fast algorithm is constructed to facilitate dose calculation for a large number of randomly sampled treatment scenarios, each representing a possible realisation of a full treatment with geometric, fraction specific displacements for an arbitrary number of fractions. The algorithm is applied to construct a dose volume coverage probability map (DVCM) based on dose calculated for several hundred treatment scenarios to enable the probabilistic evaluation of a treatment plan. For each treatment scenario, the algorithm calculates the total dose by perturbing a pre-calculated dose, separately for the primary and scatter dose components, for the nominal conditions. The ratio of the scenario specific accumulated fluence, and the average fluence for an infinite number of fractions is used to perturb the pre-calculated dose. Irregularities in the accumulated fluence may cause numerical instabilities in the ratio, which is mitigated by regularisation through convolution with a dose pencil kernel. Compared to full dose calculations the algorithm demonstrates a speedup factor of ~1000. The comparisons to full calculations show a 99% gamma index (2%/2 mm) pass rate for a single highly modulated beam in a virtual water phantom subject to setup errors during five fractions. The gamma comparison shows a 100% pass rate in a moving tumour irradiated by a single beam in a lung-like virtual phantom. DVCM iso-probability lines computed with the fast algorithm, and with full dose calculation for each of the fractions, for a hypo-fractionated prostate case treated with rotational arc therapy treatment were almost indistinguishable.

  19. A Fast and Precise Indoor Localization Algorithm Based on an Online Sequential Extreme Learning Machine †

    PubMed Central

    Zou, Han; Lu, Xiaoxuan; Jiang, Hao; Xie, Lihua

    2015-01-01

    Nowadays, developing indoor positioning systems (IPSs) has become an attractive research topic due to the increasing demands on location-based service (LBS) in indoor environments. WiFi technology has been studied and explored to provide indoor positioning service for years in view of the wide deployment and availability of existing WiFi infrastructures in indoor environments. A large body of WiFi-based IPSs adopt fingerprinting approaches for localization. However, these IPSs suffer from two major problems: the intensive costs of manpower and time for offline site survey and the inflexibility to environmental dynamics. In this paper, we propose an indoor localization algorithm based on an online sequential extreme learning machine (OS-ELM) to address the above problems accordingly. The fast learning speed of OS-ELM can reduce the time and manpower costs for the offline site survey. Meanwhile, its online sequential learning ability enables the proposed localization algorithm to adapt in a timely manner to environmental dynamics. Experiments under specific environmental changes, such as variations of occupancy distribution and events of opening or closing of doors, are conducted to evaluate the performance of OS-ELM. The simulation and experimental results show that the proposed localization algorithm can provide higher localization accuracy than traditional approaches, due to its fast adaptation to various environmental dynamics. PMID:25599427

  20. A fast and precise indoor localization algorithm based on an online sequential extreme learning machine.

    PubMed

    Zou, Han; Lu, Xiaoxuan; Jiang, Hao; Xie, Lihua

    2015-01-15

    Nowadays, developing indoor positioning systems (IPSs) has become an attractive research topic due to the increasing demands on location-based service (LBS) in indoor environments. WiFi technology has been studied and explored to provide indoor positioning service for years in view of the wide deployment and availability of existing WiFi infrastructures in indoor environments. A large body of WiFi-based IPSs adopt fingerprinting approaches for localization. However, these IPSs suffer from two major problems: the intensive costs of manpower and time for offline site survey and the inflexibility to environmental dynamics. In this paper, we propose an indoor localization algorithm based on an online sequential extreme learning machine (OS-ELM) to address the above problems accordingly. The fast learning speed of OS-ELM can reduce the time and manpower costs for the offline site survey. Meanwhile, its online sequential learning ability enables the proposed localization algorithm to adapt in a timely manner to environmental dynamics. Experiments under specific environmental changes, such as variations of occupancy distribution and events of opening or closing of doors, are conducted to evaluate the performance of OS-ELM. The simulation and experimental results show that the proposed localization algorithm can provide higher localization accuracy than traditional approaches, due to its fast adaptation to various environmental dynamics.

  1. Accelerated fast iterative shrinkage thresholding algorithms for sparsity-regularized cone-beam CT image reconstruction

    PubMed Central

    Xu, Qiaofeng; Yang, Deshan; Tan, Jun; Sawatzky, Alex; Anastasio, Mark A.

    2016-01-01

    Purpose: The development of iterative image reconstruction algorithms for cone-beam computed tomography (CBCT) remains an active and important research area. Even with hardware acceleration, the overwhelming majority of the available 3D iterative algorithms that implement nonsmooth regularizers remain computationally burdensome and have not been translated for routine use in time-sensitive applications such as image-guided radiation therapy (IGRT). In this work, two variants of the fast iterative shrinkage thresholding algorithm (FISTA) are proposed and investigated for accelerated iterative image reconstruction in CBCT. Methods: Algorithm acceleration was achieved by replacing the original gradient-descent step in the FISTAs by a subproblem that is solved by use of the ordered subset simultaneous algebraic reconstruction technique (OS-SART). Due to the preconditioning matrix adopted in the OS-SART method, two new weighted proximal problems were introduced and corresponding fast gradient projection-type algorithms were developed for solving them. We also provided efficient numerical implementations of the proposed algorithms that exploit the massive data parallelism of multiple graphics processing units. Results: The improved rates of convergence of the proposed algorithms were quantified in computer-simulation studies and by use of clinical projection data corresponding to an IGRT study. The accelerated FISTAs were shown to possess dramatically improved convergence properties as compared to the standard FISTAs. For example, the number of iterations to achieve a specified reconstruction error could be reduced by an order of magnitude. Volumetric images reconstructed from clinical data were produced in under 4 min. Conclusions: The FISTA achieves a quadratic convergence rate and can therefore potentially reduce the number of iterations required to produce an image of a specified image quality as compared to first-order methods. We have proposed and investigated

  2. A Fast Robot Identification and Mapping Algorithm Based on Kinect Sensor

    PubMed Central

    Zhang, Liang; Shen, Peiyi; Zhu, Guangming; Wei, Wei; Song, Houbing

    2015-01-01

    Internet of Things (IoT) is driving innovation in an ever-growing set of application domains such as intelligent processing for autonomous robots. For an autonomous robot, one grand challenge is how to sense its surrounding environment effectively. The Simultaneous Localization and Mapping with RGB-D Kinect camera sensor on robot, called RGB-D SLAM, has been developed for this purpose but some technical challenges must be addressed. Firstly, the efficiency of the algorithm cannot satisfy real-time requirements; secondly, the accuracy of the algorithm is unacceptable. In order to address these challenges, this paper proposes a set of novel improvement methods as follows. Firstly, the ORiented Brief (ORB) method is used in feature detection and descriptor extraction. Secondly, a bidirectional Fast Library for Approximate Nearest Neighbors (FLANN) k-Nearest Neighbor (KNN) algorithm is applied to feature match. Then, the improved RANdom SAmple Consensus (RANSAC) estimation method is adopted in the motion transformation. In the meantime, high precision General Iterative Closest Points (GICP) is utilized to register a point cloud in the motion transformation optimization. To improve the accuracy of SLAM, the reduced dynamic covariance scaling (DCS) algorithm is formulated as a global optimization problem under the G2O framework. The effectiveness of the improved algorithm has been verified by testing on standard data and comparing with the ground truth obtained on Freiburg University’s datasets. The Dr Robot X80 equipped with a Kinect camera is also applied in a building corridor to verify the correctness of the improved RGB-D SLAM algorithm. With the above experiments, it can be seen that the proposed algorithm achieves higher processing speed and better accuracy. PMID:26287198

  3. A Fast Robot Identification and Mapping Algorithm Based on Kinect Sensor.

    PubMed

    Zhang, Liang; Shen, Peiyi; Zhu, Guangming; Wei, Wei; Song, Houbing

    2015-08-14

    Internet of Things (IoT) is driving innovation in an ever-growing set of application domains such as intelligent processing for autonomous robots. For an autonomous robot, one grand challenge is how to sense its surrounding environment effectively. The Simultaneous Localization and Mapping with RGB-D Kinect camera sensor on robot, called RGB-D SLAM, has been developed for this purpose but some technical challenges must be addressed. Firstly, the efficiency of the algorithm cannot satisfy real-time requirements; secondly, the accuracy of the algorithm is unacceptable. In order to address these challenges, this paper proposes a set of novel improvement methods as follows. Firstly, the ORiented Brief (ORB) method is used in feature detection and descriptor extraction. Secondly, a bidirectional Fast Library for Approximate Nearest Neighbors (FLANN) k-Nearest Neighbor (KNN) algorithm is applied to feature match. Then, the improved RANdom SAmple Consensus (RANSAC) estimation method is adopted in the motion transformation. In the meantime, high precision General Iterative Closest Points (GICP) is utilized to register a point cloud in the motion transformation optimization. To improve the accuracy of SLAM, the reduced dynamic covariance scaling (DCS) algorithm is formulated as a global optimization problem under the G2O framework. The effectiveness of the improved algorithm has been verified by testing on standard data and comparing with the ground truth obtained on Freiburg University's datasets. The Dr Robot X80 equipped with a Kinect camera is also applied in a building corridor to verify the correctness of the improved RGB-D SLAM algorithm. With the above experiments, it can be seen that the proposed algorithm achieves higher processing speed and better accuracy.

  4. TANGO—New tracking AlGOrithm for gamma-rays

    NASA Astrophysics Data System (ADS)

    Tashenov, S.; Gerl, J.

    2010-10-01

    For spectroscopy, polarimetry and imaging purposes a new γ-ray tracking algorithm has been developed featuring identification of Compton escape events. The rejection of these events results in a significant increase of the Peak/Total ratio. The initial photon energy is restored for these events. Although the energy resolution in the spectrum reconstructed from the escape events is lower than the one from the full-energy events, the Monte-Carlo simulations show that the combined spectrum has an increased detector full-energy efficiency of up to 130% compared to its intrinsic full-energy efficiency. The assumed geometrical origin of the photons is verified event-by-event. This enables separation of photons emitted from a target and from background sources. A linear polarization analysis of the γ-lines can be performed. The efficiency of the algorithm and the Peak/Total ratio depending on the detector properties is discussed along with the proposed optimization schemes. The influence of the intrinsic properties of the scattering process like Compton profile and electron recoiling is discussed as well. The described algorithm deals with single photon events with energies of ≈100 keV up to a few MeV.

  5. Exhausting Attentional Tracking Resources with a Single Fast-Moving Object

    ERIC Educational Resources Information Center

    Holcombe, Alex O.; Chen, Wei-Ying

    2012-01-01

    Driving on a busy road, eluding a group of predators, or playing a team sport involves keeping track of multiple moving objects. In typical laboratory tasks, the number of visual targets that humans can track is about four. Three types of theories have been advanced to explain this limit. The fixed-limit theory posits a set number of attentional…

  6. A fast and frugal algorithm to strengthen diagnosis and treatment decisions for catheter-associated bacteriuria

    PubMed Central

    Naik, Aanand D.; Skelton, Felicia; Amspoker, Amber B.; Glasgow, Russell A.; Trautner, Barbara W.

    2017-01-01

    Objectives Guidelines for managing catheter-associated urinary tract infection (CAUTI) and asymptomatic bacteria (ASB) are poorly translated into routine care due in part to cognitive diagnostic errors. This study determines if the accuracy for CAUTI and ASB diagnosis and treatment improves after implementation of a fast and frugal algorithm compared with traditional education methods. Materials and methods A pre and post-intervention with contemporaneous comparison site involving inpatient and long term care wards at two regional Veterans Affairs Systems in United States. Participants included 216 internal medicine residents and 16 primary care clinicians. Intervention clinicians received training with a fast and frugal algorithm. Comparison site clinicians received guidelines education. Diagnosis and treatment accuracy compared with a criterion standard was assessed during similar three-month, pre- and post-intervention periods. Sensitivity, specificity, and likelihood ratios were compared for both periods at each site. Results Bacteriuria management was evaluated against criterion standard in 196 cases pre-implementation and 117 cases post-implementation. Accuracy of bacteriuria management among intervention participants was significantly higher, post-implementation, than those at the comparison site (Intervention: positive likelihood ratio (LR+) = 8.5, specificity = 0.89, 95% confidence interval (CI) = 0.78−1.00; comparison: LR+ = 4.62, specificity (95%CI) = 0.79 (0.63−0.95). Further, improvements at the intervention site were statistically significant (pre-implementation: LR+ = 2.1, specificity (95%CI) = 0.60 (0.50−0.71); post-implementation: LR+ = 8.5, specificity (95%CI) = 0.89 (0.78−1.00). At both sites, there were similar improvements in negative LR from pre- to post-implementation: [Intervention site = 0.28 to 0.08; comparison site = 0.13 to 0.04]. Inappropriate management of ASB declined markedly from 32 (40%) to 3 (11%) cases at the intervention

  7. Fast mapping algorithm of lighting spectrum and GPS coordinates for a large area

    NASA Astrophysics Data System (ADS)

    Lin, Chih-Wei; Hsu, Ke-Fang; Hwang, Jung-Min

    2016-09-01

    In this study, we propose a fast rebuild technology for evaluating light quality in large areas. Outdoor light quality, which is measured by illuminance uniformity and the color rendering index, is difficult to conform after improvement. We develop an algorithm for a lighting quality mapping system and coordinates using a micro spectrometer and GPS tracker integrated with a quadcopter or unmanned aerial vehicle. After cruising at a constant altitude, lighting quality data is transmitted and immediately mapped to evaluate the light quality in a large area.

  8. Radiation-hardened fast acquisition/weak signal tracking system and method

    NASA Technical Reports Server (NTRS)

    Winternitz, Luke (Inventor); Boegner, Gregory J. (Inventor); Sirotzky, Steve (Inventor)

    2009-01-01

    A global positioning system (GPS) receiver and method of acquiring and tracking GPS signals comprises an antenna adapted to receive GPS signals; an analog radio frequency device operatively connected to the antenna and adapted to convert the GPS signals from an analog format to a digital format; a plurality of GPS signal tracking correlators operatively connected to the analog RF device; a GPS signal acquisition component operatively connected to the analog RF device and the plurality of GPS signal tracking correlators, wherein the GPS signal acquisition component is adapted to calculate a maximum vector on a databit correlation grid; and a microprocessor operatively connected to the plurality of GPS signal tracking correlators and the GPS signal acquisition component, wherein the microprocessor is adapted to compare the maximum vector with a predetermined correlation threshold to allow the GPS signal to be fully acquired and tracked.

  9. ADaM: augmenting existing approximate fast matching algorithms with efficient and exact range queries

    PubMed Central

    2014-01-01

    Background Drug discovery, disease detection, and personalized medicine are fast-growing areas of genomic research. With the advancement of next-generation sequencing techniques, researchers can obtain an abundance of data for many different biological assays in a short period of time. When this data is error-free, the result is a high-quality base-pair resolution picture of the genome. However, when the data is lossy the heuristic algorithms currently used when aligning next-generation sequences causes the corresponding accuracy to drop. Results This paper describes a program, ADaM (APF DNA Mapper) which significantly increases final alignment accuracy. ADaM works by first using an existing program to align "easy" sequences, and then using an algorithm with accuracy guarantees (the APF) to align the remaining sequences. The final result is a technique that increases the mapping accuracy from only 60% to over 90% for harder-to-align sequences. PMID:25079667

  10. A fast sorting algorithm for a hypersonic rarefied flow particle simulation on the connection machine

    NASA Technical Reports Server (NTRS)

    Dagum, Leonardo

    1989-01-01

    The data parallel implementation of a particle simulation for hypersonic rarefied flow described by Dagum associates a single parallel data element with each particle in the simulation. The simulated space is divided into discrete regions called cells containing a variable and constantly changing number of particles. The implementation requires a global sort of the parallel data elements so as to arrange them in an order that allows immediate access to the information associated with cells in the simulation. Described here is a very fast algorithm for performing the necessary ranking of the parallel data elements. The performance of the new algorithm is compared with that of the microcoded instruction for ranking on the Connection Machine.

  11. Lazy skip-lists: An algorithm for fast hybridization-expansion quantum Monte Carlo

    NASA Astrophysics Data System (ADS)

    Sémon, P.; Yee, Chuck-Hou; Haule, Kristjan; Tremblay, A.-M. S.

    2014-08-01

    The solution of a generalized impurity model lies at the heart of electronic structure calculations with dynamical mean field theory. In the strongly correlated regime, the method of choice for solving the impurity model is the hybridization-expansion continuous-time quantum Monte Carlo (CT-HYB). Enhancements to the CT-HYB algorithm are critical for bringing new physical regimes within reach of current computational power. Taking advantage of the fact that the bottleneck in the algorithm is a product of hundreds of matrices, we present optimizations based on the introduction and combination of two concepts of more general applicability: (a) skip lists and (b) fast rejection of proposed configurations based on matrix bounds. Considering two very different test cases with d electrons, we find speedups of ˜25 up to ˜500 compared to the direct evaluation of the matrix product. Even larger speedups are likely with f electron systems and with clusters of correlated atoms.

  12. Statistical properties of an algorithm used for illicit substance detection by fast-neutron transmission

    SciTech Connect

    Smith, D.L.; Sagalovsky, L.; Micklich, B.J.; Harper, M.K.; Novick, A.H.

    1994-06-01

    A least-squares algorithm developed for analysis of fast-neutron transmission data resulting from non-destructive interrogation of sealed luggage and containers is subjected to a probabilistic interpretation. The approach is to convert knowledge of uncertainties in the derived areal elemental densities, as provided by this algorithm, into probability information that can be used to judge whether an interrogated object is either benign or potentially contains an illicit substance that should be investigated further. Two approaches are considered in this paper. One involves integration of a normalized probability density function associated with the least-squares solution. The other tests this solution against a hypothesis that the interrogated object indeed contains illicit material. This is accomplished by an application of the F-distribution from statistics. These two methods of data interpretation are applied to specific sets of neutron transmission results produced by Monte Carlo simulation.

  13. A new cross-diamond search algorithm for fast block motion estimation

    NASA Astrophysics Data System (ADS)

    Zhu, Shiping; Shen, Xiaodong

    2008-10-01

    In block motion estimation, search patterns have a large impact on the searching speed and quality of performance. Based on motion vector distribution characteristics of real world video sequences, we propose a new cross-diamond search algorithm (NCDS) using cross-search patterns before large/small diamond search patterns in this paper. NCDS employs halfway technique to achieve significant speedup on sequence with (quasi-) stationary blocks. NCDS employs Modified Partial Distortion Criterion (MPDC), which results in fewer search points with similar distortion. Experimental results show that the improvements of NCDS over CDS can be up to a 16% gain on speedup while similar prediction accuracy is maintained, and NCDS provides faster searching speed and smaller distortions than other popular fast block-matching algorithms.

  14. Adaptation of a Fast Optimal Interpolation Algorithm to the Mapping of Oceangraphic Data

    NASA Technical Reports Server (NTRS)

    Menemenlis, Dimitris; Fieguth, Paul; Wunsch, Carl; Willsky, Alan

    1997-01-01

    A fast, recently developed, multiscale optimal interpolation algorithm has been adapted to the mapping of hydrographic and other oceanographic data. This algorithm produces solution and error estimates which are consistent with those obtained from exact least squares methods, but at a small fraction of the computational cost. Problems whose solution would be completely impractical using exact least squares, that is, problems with tens or hundreds of thousands of measurements and estimation grid points, can easily be solved on a small workstation using the multiscale algorithm. In contrast to methods previously proposed for solving large least squares problems, our approach provides estimation error statistics while permitting long-range correlations, using all measurements, and permitting arbitrary measurement locations. The multiscale algorithm itself, published elsewhere, is not the focus of this paper. However, the algorithm requires statistical models having a very particular multiscale structure; it is the development of a class of multiscale statistical models, appropriate for oceanographic mapping problems, with which we concern ourselves in this paper. The approach is illustrated by mapping temperature in the northeastern Pacific. The number of hydrographic stations is kept deliberately small to show that multiscale and exact least squares results are comparable. A portion of the data were not used in the analysis; these data serve to test the multiscale estimates. A major advantage of the present approach is the ability to repeat the estimation procedure a large number of times for sensitivity studies, parameter estimation, and model testing. We have made available by anonymous Ftp a set of MATLAB-callable routines which implement the multiscale algorithm and the statistical models developed in this paper.

  15. A Fast Algorithm for 2D DOA Estimation Using an Omnidirectional Sensor Array.

    PubMed

    Nie, Weike; Xu, Kaijie; Feng, Dazheng; Wu, Chase Qishi; Hou, Aiqin; Yin, Xiaoyan

    2017-03-04

    The traditional 2D MUSIC algorithm fixes the azimuth or the elevation, and searches for the other without considering the directions of sources. A spectrum peak diffusion effect phenomenon is observed and may be utilized to detect the approximate directions of sources. Accordingly, a fast 2D MUSIC algorithm, which performs azimuth and elevation simultaneous searches (henceforth referred to as AESS) based on only three rounds of search is proposed. Firstly, AESS searches along a circle to detect the approximate source directions. Then, a subsequent search is launched along several straight lines based on these approximate directions. Finally, the 2D Direction of Arrival (DOA) of each source is derived by searching on several small concentric circles. Unlike the 2D MUSIC algorithm, AESS does not fix any azimuth and elevation parameters. Instead, the adjacent point of each search possesses different azimuth and elevation, i.e., azimuth and elevation are simultaneously searched to ensure that the search path is minimized, and hence the total spectral search over the angular field of view is avoided. Simulation results demonstrate the performance characters of the proposed AESS over some existing algorithms.

  16. A fast 3D image simulation algorithm of moving target for scanning laser radar

    NASA Astrophysics Data System (ADS)

    Li, Jicheng; Shi, Zhiguang; Chen, Xiao; Chen, Dong

    2014-10-01

    Scanning Laser Radar has been widely used in many military and civil areas. Usually there are relative movements between the target and the radar, so the moving target image modeling and simulation is an important research content in the field of signal processing and system design of scan-imaging laser radar. In order to improve the simulation speed and hold the accuracy of the image simulation simultaneously, a novel fast simulation algorithm is proposed in this paper. Firstly, for moving target or varying scene, an inequation that can judge the intersection relations between the pixel and target bins is obtained by deriving the projection of target motion trajectories on the image plane. Then, by utilizing the time subdivision and approximate treatments, the potential intersection relations of pixel and target bins are determined. Finally, the goal of reducing the number of intersection operations could be achieved by testing all the potential relations and finding which of them is real intersection. To test the method's performance, we perform computer simulations of both the new proposed algorithm and a literature's algorithm for six targets. The simulation results show that the two algorithm yield the same imaging result, whereas the number of intersection operations of former is equivalent to only 1% of the latter, and the calculation efficiency increases a hundredfold. The novel simulation acceleration idea can be applied extensively in other more complex application environments and provide equally acceleration effect. It is very suitable for the case to produce a great large number of laser radar images.

  17. Fast-kick-off monotonically convergent algorithm for searching optimal control fields

    SciTech Connect

    Liao, Sheng-Lun; Ho, Tak-San; Rabitz, Herschel; Chu, Shih-I

    2011-09-15

    This Rapid Communication presents a fast-kick-off search algorithm for quickly finding optimal control fields in the state-to-state transition probability control problems, especially those with poorly chosen initial control fields. The algorithm is based on a recently formulated monotonically convergent scheme [T.-S. Ho and H. Rabitz, Phys. Rev. E 82, 026703 (2010)]. Specifically, the local temporal refinement of the control field at each iteration is weighted by a fractional inverse power of the instantaneous overlap of the backward-propagating wave function, associated with the target state and the control field from the previous iteration, and the forward-propagating wave function, associated with the initial state and the concurrently refining control field. Extensive numerical simulations for controls of vibrational transitions and ultrafast electron tunneling show that the new algorithm not only greatly improves the search efficiency but also is able to attain good monotonic convergence quality when further frequency constraints are required. The algorithm is particularly effective when the corresponding control dynamics involves a large number of energy levels or ultrashort control pulses.

  18. A Fast Algorithm of Convex Hull Vertices Selection for Online Classification.

    PubMed

    Ding, Shuguang; Nie, Xiangli; Qiao, Hong; Zhang, Bo

    2017-01-20

    Reducing samples through convex hull vertices selection (CHVS) within each class is an important and effective method for online classification problems, since the classifier can be trained rapidly with the selected samples. However, the process of CHVS is NP-hard. In this paper, we propose a fast algorithm to select the convex hull vertices, based on the convex hull decomposition and the property of projection. In the proposed algorithm, the quadratic minimization problem of computing the distance between a point and a convex hull is converted into a linear equation problem with a low computational complexity. When the data dimension is high, an approximate, instead of exact, convex hull is allowed to be selected by setting an appropriate termination condition in order to delete more nonimportant samples. In addition, the impact of outliers is also considered, and the proposed algorithm is improved by deleting the outliers in the initial procedure. Furthermore, a dimension convention technique via the kernel trick is used to deal with nonlinearly separable problems. An upper bound is theoretically proved for the difference between the support vector machines based on the approximate convex hull vertices selected and all the training samples. Experimental results on both synthetic and real data sets show the effectiveness and validity of the proposed algorithm.

  19. A Fast Algorithm for 2D DOA Estimation Using an Omnidirectional Sensor Array

    PubMed Central

    Nie, Weike; Xu, Kaijie; Feng, Dazheng; Wu, Chase Qishi; Hou, Aiqin; Yin, Xiaoyan

    2017-01-01

    The traditional 2D MUSIC algorithm fixes the azimuth or the elevation, and searches for the other without considering the directions of sources. A spectrum peak diffusion effect phenomenon is observed and may be utilized to detect the approximate directions of sources. Accordingly, a fast 2D MUSIC algorithm, which performs azimuth and elevation simultaneous searches (henceforth referred to as AESS) based on only three rounds of search is proposed. Firstly, AESS searches along a circle to detect the approximate source directions. Then, a subsequent search is launched along several straight lines based on these approximate directions. Finally, the 2D Direction of Arrival (DOA) of each source is derived by searching on several small concentric circles. Unlike the 2D MUSIC algorithm, AESS does not fix any azimuth and elevation parameters. Instead, the adjacent point of each search possesses different azimuth and elevation, i.e., azimuth and elevation are simultaneously searched to ensure that the search path is minimized, and hence the total spectral search over the angular field of view is avoided. Simulation results demonstrate the performance characters of the proposed AESS over some existing algorithms. PMID:28273851

  20. A videofluoroscopy-based tracking algorithm for quantifying the time course of human intervertebral displacements.

    PubMed

    Balkovec, Christian; Veldhuis, Jim H; Baird, John W; Brodland, G Wayne; McGill, Stuart M

    2017-03-15

    The motions of individual intervertebral joints can affect spine motion, injury risk, deterioration, pain, treatment strategies, and clinical outcomes. Since standard kinematic methods do not provide precise time-course details about individual vertebrae and intervertebral motions, information that could be useful for scientific advancement and clinical assessment, we developed an iterative template matching algorithm to obtain this data from videofluoroscopy images. To assess the bias of our approach, vertebrae in an intact porcine spine were tracked and compared to the motions of high-contrast markers. To estimate precision under clinical conditions, motions of three human cervical spines were tracked independently ten times and vertebral and intervertebral motions associated with individual trials were compared to corresponding averages. Both tests produced errors in intervertebral angular and shear displacements no greater than 0.4° and 0.055 mm, respectively. When applied to two patient cases, aberrant intervertebral motions in the cervical spine were typically found to correlate with patient-specific anatomical features such as disc height loss and osteophytes. The case studies suggest that intervertebral kinematic time-course data could have value in clinical assessments, lead to broader understanding of how specific anatomical features influence joint motions, and in due course inform clinical treatments.

  1. Fast double-phase retrieval in Fresnel domain using modified Gerchberg-Saxton algorithm for lensless optical security systems.

    PubMed

    Hwang, Hone-Ene; Chang, Hsuan T; Lie, Wen-Nung

    2009-08-03

    A novel fast double-phase retrieval algorithm for lensless optical security systems based on the Fresnel domain is presented in this paper. Two phase-only masks are efficiently determined by using a modified Gerchberg-Saxton algorithm, in which two cascaded Fresnel transforms are replaced by one Fourier transform with compensations to reduce the consumed computations. Simulation results show that the proposed algorithm substantially speeds up the iterative process, while keeping the reconstructed image highly correlated with the original one.

  2. Fast and Accurate Cell Tracking by a Novel Optical-Digital Hybrid Method

    NASA Astrophysics Data System (ADS)

    Torres-Cisneros, M.; Aviña-Cervantes, J. G.; Pérez-Careta, E.; Ambriz-Colín, F.; Tinoco, Verónica; Ibarra-Manzano, O. G.; Plascencia-Mora, H.; Aguilera-Gómez, E.; Ibarra-Manzano, M. A.; Guzman-Cabrera, R.; Debeir, Olivier; Sánchez-Mondragón, J. J.

    2013-09-01

    An innovative methodology to detect and track cells using microscope images enhanced by optical cross-correlation techniques is proposed in this paper. In order to increase the tracking sensibility, image pre-processing has been implemented as a morphological operator on the microscope image. Results show that the pre-processing process allows for additional frames of cell tracking, therefore increasing its robustness. The proposed methodology can be used in analyzing different problems such as mitosis, cell collisions, and cell overlapping, ultimately designed to identify and treat illnesses and malignancies.

  3. FAST-PT II: an algorithm to calculate convolution integrals of general tensor quantities in cosmological perturbation theory

    NASA Astrophysics Data System (ADS)

    Fang, Xiao; Blazek, Jonathan A.; McEwen, Joseph E.; Hirata, Christopher M.

    2017-02-01

    Cosmological perturbation theory is a powerful tool to predict the statistics of large-scale structure in the weakly non-linear regime, but even at 1-loop order it results in computationally expensive mode-coupling integrals. Here we present a fast algorithm for computing 1-loop power spectra of quantities that depend on the observer's orientation, thereby generalizing the FAST-PT framework (McEwen et al., 2016) that was originally developed for scalars such as the matter density. This algorithm works for an arbitrary input power spectrum and substantially reduces the time required for numerical evaluation. We apply the algorithm to four examples: intrinsic alignments of galaxies in the tidal torque model; the Ostriker-Vishniac effect; the secondary CMB polarization due to baryon flows; and the 1-loop matter power spectrum in redshift space. Code implementing this algorithm and these applications is publicly available at https://github.com/JoeMcEwen/FAST-PT.

  4. Performance Evaluation of Block Acquisition and Tracking Algorithms Using an Open Source GPS Receiver Platform

    NASA Technical Reports Server (NTRS)

    Ramachandran, Ganesh K.; Akopian, David; Heckler, Gregory W.; Winternitz, Luke B.

    2011-01-01

    Location technologies have many applications in wireless communications, military and space missions, etc. US Global Positioning System (GPS) and other existing and emerging Global Navigation Satellite Systems (GNSS) are expected to provide accurate location information to enable such applications. While GNSS systems perform very well in strong signal conditions, their operation in many urban, indoor, and space applications is not robust or even impossible due to weak signals and strong distortions. The search for less costly, faster and more sensitive receivers is still in progress. As the research community addresses more and more complicated phenomena there exists a demand on flexible multimode reference receivers, associated SDKs, and development platforms which may accelerate and facilitate the research. One of such concepts is the software GPS/GNSS receiver (GPS SDR) which permits a facilitated access to algorithmic libraries and a possibility to integrate more advanced algorithms without hardware and essential software updates. The GNU-SDR and GPS-SDR open source receiver platforms are such popular examples. This paper evaluates the performance of recently proposed block-corelator techniques for acquisition and tracking of GPS signals using open source GPS-SDR platform.

  5. A proposed Fast algorithm to construct the system matrices for a reduced-order groundwater model

    NASA Astrophysics Data System (ADS)

    Ushijima, Timothy T.; Yeh, William W.-G.

    2017-04-01

    Past research has demonstrated that a reduced-order model (ROM) can be two-to-three orders of magnitude smaller than the original model and run considerably faster with acceptable error. A standard method to construct the system matrices for a ROM is Proper Orthogonal Decomposition (POD), which projects the system matrices from the full model space onto a subspace whose range spans the full model space but has a much smaller dimension than the full model space. This projection can be prohibitively expensive to compute if it must be done repeatedly, as with a Monte Carlo simulation. We propose a Fast Algorithm to reduce the computational burden of constructing the system matrices for a parameterized, reduced-order groundwater model (i.e. one whose parameters are represented by zones or interpolation functions). The proposed algorithm decomposes the expensive system matrix projection into a set of simple scalar-matrix multiplications. This allows the algorithm to efficiently construct the system matrices of a POD reduced-order model at a significantly reduced computational cost compared with the standard projection-based method. The developed algorithm is applied to three test cases for demonstration purposes. The first test case is a small, two-dimensional, zoned-parameter, finite-difference model; the second test case is a small, two-dimensional, interpolated-parameter, finite-difference model; and the third test case is a realistically-scaled, two-dimensional, zoned-parameter, finite-element model. In each case, the algorithm is able to accurately and efficiently construct the system matrices of the reduced-order model.

  6. The performance analysis of three-dimensional track-before-detect algorithm based on Fisher-Tippett-Gnedenko theorem

    NASA Astrophysics Data System (ADS)

    Cho, Hoonkyung; Chun, Joohwan; Song, Sungchan

    2016-09-01

    The dim moving target tracking from the infrared image sequence in the presence of high clutter and noise has been recently under intensive investigation. The track-before-detect (TBD) algorithm processing the image sequence over a number of frames before decisions on the target track and existence is known to be especially attractive in very low SNR environments (⩽ 3 dB). In this paper, we shortly present a three-dimensional (3-D) TBD with dynamic programming (TBD-DP) algorithm using multiple IR image sensors. Since traditional two-dimensional TBD algorithm cannot track and detect the along the viewing direction, we use 3-D TBD with multiple sensors and also strictly analyze the detection performance (false alarm and detection probabilities) based on Fisher-Tippett-Gnedenko theorem. The 3-D TBD-DP algorithm which does not require a separate image registration step uses the pixel intensity values jointly read off from multiple image frames to compute the merit function required in the DP process. Therefore, we also establish the relationship between the pixel coordinates of image frame and the reference coordinates.

  7. Design of a fast echo matching algorithm to reduce crosstalk with Doppler shifts in ultrasonic ranging

    NASA Astrophysics Data System (ADS)

    Liu, Lei; Guo, Rui; Wu, Jun-an

    2017-02-01

    Crosstalk is a main factor for wrong distance measurement by ultrasonic sensors, and this problem becomes more difficult to deal with under Doppler effects. In this paper, crosstalk reduction with Doppler shifts on small platforms is focused on, and a fast echo matching algorithm (FEMA) is proposed on the basis of chaotic sequences and pulse coding technology, then verified through applying it to match practical echoes. Finally, we introduce how to select both better mapping methods for chaotic sequences, and algorithm parameters for higher achievable maximum of cross-correlation peaks. The results indicate the following: logistic mapping is preferred to generate good chaotic sequences, with high autocorrelation even when the length is very limited; FEMA can not only match echoes and calculate distance accurately with an error degree mostly below 5%, but also generates nearly the same calculation cost level for static or kinematic ranging, much lower than that by direct Doppler compensation (DDC) with the same frequency compensation step; The sensitivity to threshold value selection and performance of FEMA depend significantly on the achievable maximum of cross-correlation peaks, and a higher peak is preferred, which can be considered as a criterion for algorithm parameter optimization under practical conditions.

  8. A fast density-based clustering algorithm for real-time Internet of Things stream.

    PubMed

    Amini, Amineh; Saboohi, Hadi; Wah, Teh Ying; Herawan, Tutut

    2014-01-01

    Data streams are continuously generated over time from Internet of Things (IoT) devices. The faster all of this data is analyzed, its hidden trends and patterns discovered, and new strategies created, the faster action can be taken, creating greater value for organizations. Density-based method is a prominent class in clustering data streams. It has the ability to detect arbitrary shape clusters, to handle outlier, and it does not need the number of clusters in advance. Therefore, density-based clustering algorithm is a proper choice for clustering IoT streams. Recently, several density-based algorithms have been proposed for clustering data streams. However, density-based clustering in limited time is still a challenging issue. In this paper, we propose a density-based clustering algorithm for IoT streams. The method has fast processing time to be applicable in real-time application of IoT devices. Experimental results show that the proposed approach obtains high quality results with low computation time on real and synthetic datasets.

  9. A fast calculating two-stream-like multiple scattering algorithm that captures azimuthal and elevation variations

    NASA Astrophysics Data System (ADS)

    Fiorino, Steven T.; Elmore, Brannon; Schmidt, Jaclyn; Matchefts, Elizabeth; Burley, Jarred L.

    2016-05-01

    Properly accounting for multiple scattering effects can have important implications for remote sensing and possibly directed energy applications. For example, increasing path radiance can affect signal noise. This study describes the implementation of a fast-calculating two-stream-like multiple scattering algorithm that captures azimuthal and elevation variations into the Laser Environmental Effects Definition and Reference (LEEDR) atmospheric characterization and radiative transfer code. The multiple scattering algorithm fully solves for molecular, aerosol, cloud, and precipitation single-scatter layer effects with a Mie algorithm at every calculation point/layer rather than an interpolated value from a pre-calculated look-up-table. This top-down cumulative diffusivity method first considers the incident solar radiance contribution to a given layer accounting for solid angle and elevation, and it then measures the contribution of diffused energy from previous layers based on the transmission of the current level to produce a cumulative radiance that is reflected from a surface and measured at the aperture at the observer. Then a unique set of asymmetry and backscattering phase function parameter calculations are made which account for the radiance loss due to the molecular and aerosol constituent reflectivity within a level and allows for a more accurate characterization of diffuse layers that contribute to multiple scattered radiances in inhomogeneous atmospheres. The code logic is valid for spectral bands between 200 nm and radio wavelengths, and the accuracy is demonstrated by comparing the results from LEEDR to observed sky radiance data.

  10. A New Fast Algorithm to Completely Account for Non-Lambertian Surface Reflection of The Earth

    NASA Technical Reports Server (NTRS)

    Qin, Wen-Han; Herman, Jay R.; Ahmad, Ziauddin; Einaudi, Franco (Technical Monitor)

    2000-01-01

    Surface bidirectional reflectance distribution function (BRDF) influences not only radiance just about the surface, but that emerging from the top of the atmosphere (TOA). In this study we propose a new, fast and accurate, algorithm CASBIR (correction for anisotropic surface bidirectional reflection) to account for such influences on radiance measured above TOA. This new algorithm is based on a 4-stream theory that separates the radiation field into direct and diffuse components in both upwelling and downwelling directions. This is important because the direct component accounts for a substantial portion of incident radiation under a clear sky, and the BRDF effect is strongest in the reflection of the direct radiation reaching the surface. The model is validated by comparison with a full-scale, vector radiation transfer model for the atmosphere-surface system. The result demonstrates that CASBIR performs very well (with overall relative difference of less than one percent) for all solar and viewing zenith and azimuth angles considered in wavelengths from ultraviolet to near-infrared over three typical, but very different surface types. Application of this algorithm includes both accounting for non-Lambertian surface scattering on the emergent radiation above TOA and a potential approach for surface BRDF retrieval from satellite measured radiance.

  11. Automatic building detection based on Purposive FastICA (PFICA) algorithm using monocular high resolution Google Earth images

    NASA Astrophysics Data System (ADS)

    Ghaffarian, Saman; Ghaffarian, Salar

    2014-11-01

    This paper proposes an improved FastICA model named as Purposive FastICA (PFICA) with initializing by a simple color space transformation and a novel masking approach to automatically detect buildings from high resolution Google Earth imagery. ICA and FastICA algorithms are defined as Blind Source Separation (BSS) techniques for unmixing source signals using the reference data sets. In order to overcome the limitations of the ICA and FastICA algorithms and make them purposeful, we developed a novel method involving three main steps: 1-Improving the FastICA algorithm using Moore-Penrose pseudo inverse matrix model, 2-Automated seeding of the PFICA algorithm based on LUV color space and proposed simple rules to split image into three regions; shadow + vegetation, baresoil + roads and buildings, respectively, 3-Masking out the final building detection results from PFICA outputs utilizing the K-means clustering algorithm with two number of clusters and conducting simple morphological operations to remove noises. Evaluation of the results illustrates that buildings detected from dense and suburban districts with divers characteristics and color combinations using our proposed method have 88.6% and 85.5% overall pixel-based and object-based precision performances, respectively.

  12. Accuracy of tumor motion compensation algorithm from a robotic respiratory tracking system: A simulation study

    SciTech Connect

    Seppenwoolde, Yvette; Berbeco, Ross I.; Nishioka, Seiko; Shirato, Hiroki; Heijmen, Ben

    2007-07-15

    The Synchrony{sup TM} Respiratory Tracking System (RTS) is a treatment option of the CyberKnife robotic treatment device to irradiate extra-cranial tumors that move due to respiration. Advantages of RTS are that patients can breath normally and that there is no loss of linac duty cycle such as with gated therapy. Tracking is based on a measured correspondence model (linear or polynomial) between internal tumor motion and external (chest/abdominal) marker motion. The radiation beam follows the tumor movement via the continuously measured external marker motion. To establish the correspondence model at the start of treatment, the 3D internal tumor position is determined at 15 discrete time points by automatic detection of implanted gold fiducials in two orthogonal x-ray images; simultaneously, the positions of the external markers are measured. During the treatment, the relationship between internal and external marker positions is continuously accounted for and is regularly checked and updated. Here we use computer simulations based on continuously and simultaneously recorded internal and external marker positions to investigate the effectiveness of tumor tracking by the RTS. The Cyberknife does not allow continuous acquisition of x-ray images to follow the moving internal markers (typical imaging frequency is once per minute). Therefore, for the simulations, we have used data for eight lung cancer patients treated with respiratory gating. All of these patients had simultaneous and continuous recordings of both internal tumor motion and external abdominal motion. The available continuous relationship between internal and external markers for these patients allowed investigation of the consequences of the lower acquisition frequency of the RTS. With the use of the RTS, simulated treatment errors due to breathing motion were reduced largely and consistently over treatment time for all studied patients. A considerable part of the maximum reduction in treatment error

  13. High-dynamic GPS tracking

    NASA Technical Reports Server (NTRS)

    Hinedi, S.; Statman, J. I.

    1988-01-01

    The results of comparing four different frequency estimation schemes in the presence of high dynamics and low carrier-to-noise ratios are given. The comparison is based on measured data from a hardware demonstration. The tested algorithms include a digital phase-locked loop, a cross-product automatic frequency tracking loop, and extended Kalman filter, and finally, a fast Fourier transformation-aided cross-product frequency tracking loop. The tracking algorithms are compared on their frequency error performance and their ability to maintain lock during severe maneuvers at various carrier-to-noise ratios. The measured results are shown to agree with simulation results carried out and reported previously.

  14. Evaluation of a photovoltaic energy mechatronics system with a built-in quadratic maximum power point tracking algorithm

    SciTech Connect

    Chao, R.M.; Ko, S.H.; Lin, I.H.; Pai, F.S.; Chang, C.C.

    2009-12-15

    The historically high cost of crude oil price is stimulating research into solar (green) energy as an alternative energy source. In general, applications with large solar energy output require a maximum power point tracking (MPPT) algorithm to optimize the power generated by the photovoltaic effect. This work aims to provide a stand-alone solution for solar energy applications by integrating a DC/DC buck converter to a newly developed quadratic MPPT algorithm along with its appropriate software and hardware. The quadratic MPPT method utilizes three previously used duty cycles with their corresponding power outputs. It approaches the maximum value by using a second order polynomial formula, which converges faster than the existing MPPT algorithm. The hardware implementation takes advantage of the real-time controller system from National Instruments, USA. Experimental results have shown that the proposed solar mechatronics system can correctly and effectively track the maximum power point without any difficulties. (author)

  15. Quantitative measurement of Parkinsonian gait from walking in monocular image sequences using a centroid tracking algorithm.

    PubMed

    Lin, Sheng-Huang; Chen, Shih-Wei; Lo, Yu-Chun; Lai, Hsin-Yi; Yang, Chich-Haung; Chen, Shin-Yuan; Chang, Yuan-Jen; Chen, Chin-Hsing; Huang, Wen-Tzeng; Jaw, Fu-Shan; Chen, You-Yin; Tsang, Siny; Liao, Lun-De

    2016-03-01

    Parkinson's disease (PD) is a neurodegenerative disease of the central nervous system that results from the degeneration of dopaminergic neurons in the substantia nigra. Abnormal gait begins in the early stage and becomes severe as the disease progresses; therefore, the assessment of gait becomes an important issue in evaluating the progression of PD and the effectiveness of treatment. To provide a clinically useful gait assessment in environments with budget and space limitations, such as a small clinic or home, we propose and develop a portable method utilizing the monocular image sequences of walking to track and analyze a Parkinsonian gait pattern. In addition, a centroid tracking algorithm is developed and used here to enhance the method of quantifying kinematic gait parameters of PD in different states. Twelve healthy subjects and twelve mild patients with PD participate in this study. This method requires one digital video camera and subjects with two joint markers attached on the fibula head and the lateral malleolus of the leg. All subjects walk with a natural pace in front of a video camera during the trials. Results of our study demonstrate the stride length and walking velocity significantly decrease in PD without drug compared to PD with drug in both proposed method and simultaneous gait assessment performed by GAITRite(®) system. In gait initiation, step length and swing velocity also decrease in PD without drug compared to both PD with drug and controls. Our results showed high correlation in gait parameters between the two methods and prove the reliability of the proposed method. With the proposed method, quantitative measurement and analysis of Parkinsonian gait could be inexpensive to implement, portable within a small clinic or home, easy to administer, and simple to interpret. Although this study is assessed Parkinsonian gait, the proposed method has the potential to help clinicians and researchers assess the gait of patients with other

  16. Pre-Hardware Optimization and Implementation Of Fast Optics Closed Control Loop Algorithms

    NASA Technical Reports Server (NTRS)

    Kizhner, Semion; Lyon, Richard G.; Herman, Jay R.; Abuhassan, Nader

    2004-01-01

    One of the main heritage tools used in scientific and engineering data spectrum analysis is the Fourier Integral Transform and its high performance digital equivalent - the Fast Fourier Transform (FFT). The FFT is particularly useful in two-dimensional (2-D) image processing (FFT2) within optical systems control. However, timing constraints of a fast optics closed control loop would require a supercomputer to run the software implementation of the FFT2 and its inverse, as well as other image processing representative algorithm, such as numerical image folding and fringe feature extraction. A laboratory supercomputer is not always available even for ground operations and is not feasible for a night project. However, the computationally intensive algorithms still warrant alternative implementation using reconfigurable computing technologies (RC) such as Digital Signal Processors (DSP) and Field Programmable Gate Arrays (FPGA), which provide low cost compact super-computing capabilities. We present a new RC hardware implementation and utilization architecture that significantly reduces the computational complexity of a few basic image-processing algorithm, such as FFT2, image folding and phase diversity for the NASA Solar Viewing Interferometer Prototype (SVIP) using a cluster of DSPs and FPGAs. The DSP cluster utilization architecture also assures avoidance of a single point of failure, while using commercially available hardware. This, combined with the control algorithms pre-hardware optimization, or the first time allows construction of image-based 800 Hertz (Hz) optics closed control loops on-board a spacecraft, based on the SVIP ground instrument. That spacecraft is the proposed Earth Atmosphere Solar Occultation Imager (EASI) to study greenhouse gases CO2, C2H, H2O, O3, O2, N2O from Lagrange-2 point in space. This paper provides an advanced insight into a new type of science capabilities for future space exploration missions based on on-board image processing

  17. Algorithms for searching Fast radio bursts and pulsars in tight binary systems.

    NASA Astrophysics Data System (ADS)

    Zackay, Barak

    2017-01-01

    Fast radio bursts (FRB's) are an exciting, recently discovered, astrophysical transients which their origins are unknown.Currently, these bursts are believed to be coming from cosmological distances, allowing us to probe the electron content on cosmological length scales. Even though their precise localization is crucial for the determination of their origin, radio interferometers were not extensively employed in searching for them due to computational limitations.I will briefly present the Fast Dispersion Measure Transform (FDMT) algorithm,that allows to reduce the operation count in blind incoherent dedispersion by 2-3 orders of magnitude.In addition, FDMT enables to probe the unexplored domain of sub-microsecond astrophysical pulses.Pulsars in tight binary systems are among the most important astrophysical objects as they provide us our best tests of general relativity in the strong field regime.I will provide a preview to a novel algorithm that enables the detection of pulsars in short binary systems using observation times longer than an orbital period.Current pulsar search programs limit their searches for integration times shorter than a few percents of the orbital period.Until now, searching for pulsars in binary systems using observation times longer than an orbital period was considered impossible as one has to blindly enumerate all options for the Keplerian parameters, the pulsar rotation period, and the unknown DM.Using the current state of the art pulsar search techniques and all computers on the earth, such an enumeration would take longer than a Hubble time. I will demonstrate that using the new algorithm, it is possible to conduct such an enumeration on a laptop using real data of the double pulsar PSR J0737-3039.Among the other applications of this algorithm are:1) Searching for all pulsars on all sky positions in gamma ray observations of the Fermi LAT satellite.2) Blind searching for continuous gravitational wave sources emitted by pulsars with

  18. Can Genetics Predict Response to Complex Behavioral Interventions? Evidence from a Genetic Analysis of the Fast Track Randomized Control Trial.

    PubMed

    Albert, Dustin; Belsky, Daniel W; Crowley, D Max; Latendresse, Shawn J; Aliev, Fazil; Riley, Brien; Sun, Cuie; Dick, Danielle M; Dodge, Kenneth A

    2015-01-01

    Early interventions are a preferred method for addressing behavioral problems in high-risk children, but often have only modest effects. Identifying sources of variation in intervention effects can suggest means to improve efficiency. One potential source of such variation is the genome. We conducted a genetic analysis of the Fast Track randomized control trial, a 10-year-long intervention to prevent high-risk kindergarteners from developing adult externalizing problems including substance abuse and antisocial behavior. We tested whether variants of the glucocorticoid receptor gene NR3C1 were associated with differences in response to the Fast Track intervention. We found that in European-American children, a variant of NR3C1 identified by the single-nucleotide polymorphism rs10482672 was associated with increased risk for externalizing psychopathology in control group children and decreased risk for externalizing psychopathology in intervention group children. Variation in NR3C1 measured in this study was not associated with differential intervention response in African-American children. We discuss implications for efforts to prevent externalizing problems in high-risk children and for public policy in the genomic era.

  19. Automatic brain tumor segmentation with a fast Mumford-Shah algorithm

    NASA Astrophysics Data System (ADS)

    Müller, Sabine; Weickert, Joachim; Graf, Norbert

    2016-03-01

    We propose a fully-automatic method for brain tumor segmentation that does not require any training phase. Our approach is based on a sequence of segmentations using the Mumford-Shah cartoon model with varying parameters. In order to come up with a very fast implementation, we extend the recent primal-dual algorithm of Strekalovskiy et al. (2014) from the 2D to the medically relevant 3D setting. Moreover, we suggest a new confidence refinement and show that it can increase the precision of our segmentations substantially. Our method is evaluated on 188 data sets with high-grade gliomas and 25 with low-grade gliomas from the BraTS14 database. Within a computation time of only three minutes, we achieve Dice scores that are comparable to state-of-the-art methods.

  20. Program for the analysis of time series. [by means of fast Fourier transform algorithm

    NASA Technical Reports Server (NTRS)

    Brown, T. J.; Brown, C. G.; Hardin, J. C.

    1974-01-01

    A digital computer program for the Fourier analysis of discrete time data is described. The program was designed to handle multiple channels of digitized data on general purpose computer systems. It is written, primarily, in a version of FORTRAN 2 currently in use on CDC 6000 series computers. Some small portions are written in CDC COMPASS, an assembler level code. However, functional descriptions of these portions are provided so that the program may be adapted for use on any facility possessing a FORTRAN compiler and random-access capability. Properly formatted digital data are windowed and analyzed by means of a fast Fourier transform algorithm to generate the following functions: (1) auto and/or cross power spectra, (2) autocorrelations and/or cross correlations, (3) Fourier coefficients, (4) coherence functions, (5) transfer functions, and (6) histograms.

  1. Fast conical surface evaluation via randomized algorithm in the null-screen test

    NASA Astrophysics Data System (ADS)

    Aguirre-Aguirre, D.; Díaz-Uribe, R.; Villalobos-Mendoza, B.

    2017-01-01

    This work shows a method to recover the shape of the surface via randomized algorithms when the null-screen test is used, instead of the integration process that is commonly performed. This, because the majority of the errors are added during the reconstruction of the surface (or the integration process). This kind of large surfaces are widely used in the aerospace sector and industry in general, and a big problem exists when these surfaces have to be tested. The null-screen method is a low-cost test, and a complete surface analysis can be done by using this method. In this paper, we show the simulations done for the analysis of fast conic surfaces, where it was proved that the quality and shape of a surface under study can be recovered with a percentage error < 2.

  2. Fast String Search on Multicore Processors: Mapping fundamental algorithms onto parallel hardware

    SciTech Connect

    Scarpazza, Daniele P.; Villa, Oreste; Petrini, Fabrizio

    2008-04-01

    String searching is one of these basic algorithms. It has a host of applications, including search engines, network intrusion detection, virus scanners, spam filters, and DNA analysis, among others. The Cell processor, with its multiple cores, promises to speed-up string searching a lot. In this article, we show how we mapped string searching efficiently on the Cell. We present two implementations: • The fast implementation supports a small dictionary size (approximately 100 patterns) and provides a throughput of 40 Gbps, which is 100 times faster than reference implementations on x86 architectures. • The heavy-duty implementation is slower (3.3-4.3 Gbps), but supports dictionaries with tens of thousands of strings.

  3. Correlated image set compression system based on new fast efficient algorithm of Karhunen-Loeve transform

    NASA Astrophysics Data System (ADS)

    Musatenko, Yurij S.; Kurashov, Vitalij N.

    1998-10-01

    The paper presents improved version of our new method for compression of correlated image sets Optimal Image Coding using Karhunen-Loeve transform (OICKL). It is known that Karhunen-Loeve (KL) transform is most optimal representation for such a purpose. The approach is based on fact that every KL basis function gives maximum possible average contribution in every image and this contribution decreases most quickly among all possible bases. So, we lossy compress every KL basis function by Embedded Zerotree Wavelet (EZW) coding with essentially different loss that depends on the functions' contribution in the images. The paper presents new fast low memory consuming algorithm of KL basis construction for compression of correlated image ensembles that enable our OICKL system to work on common hardware. We also present procedure for determining of optimal losses of KL basic functions caused by compression. It uses modified EZW coder which produce whole PSNR (bitrate) curve during the only compression pass.

  4. Simulation of Anderson localization in a random fiber using a fast Fresnel diffraction algorithm

    NASA Astrophysics Data System (ADS)

    Davis, Jeffrey A.; Cottrell, Don M.

    2016-06-01

    Anderson localization has been previously demonstrated both theoretically and experimentally for transmission of a Gaussian beam through long distances in an optical fiber consisting of a random array of smaller fibers, each having either a higher or lower refractive index. However, the computational times were extremely long. We show how to simulate these results using a fast Fresnel diffraction algorithm. In each iteration of this approach, the light passes through a phase mask, undergoes Fresnel diffraction over a small distance, and then passes through the same phase mask. We also show results where we use a binary amplitude mask at the input that selectively illuminates either the higher or the lower index fibers. Additionally, we examine imaging of various sized objects through these fibers. In all cases, our results are consistent with other computational methods and experimental results, but with a much reduced computational time.

  5. A multi-threaded mosaicking algorithm for fast image composition of fluorescence bladder images

    NASA Astrophysics Data System (ADS)

    Behrens, Alexander; Bommes, Michael; Stehle, Thomas; Gross, Sebastian; Leonhardt, Steffen; Aach, Til

    2010-02-01

    The treatment of urinary bladder cancer is usually carried out using fluorescence endoscopy. A narrow-band bluish illumination activates a tumor marker resulting in a red fluorescence. Because of low illumination power the distance between endoscope and bladder wall is kept low during the whole bladder scan, which is carried out before treatment. Thus, only a small field of view (FOV) of the operation field is provided, which impedes navigation and relocating of multi-focal tumors. Although off-line calculated panorama images can assist surgery planning, the immediate display of successively growing overview images composed from single video frames in real-time during the bladder scan, is well suited to ease navigation and reduce the risk of missing tumors. Therefore we developed an image mosaicking algorithm for fluorescence endoscopy. Due to fast computation requirements a flexible multi-threaded software architecture based on our RealTimeFrame platform is developed. Different algorithm tasks, like image feature extraction, matching and stitching are separated and applied by independent processing threads. Thus, different implementation of single tasks can be easily evaluated. In an optimization step we evaluate the trade-off between feature repeatability and total processing time, consider the thread synchronization, and achieve a constant workload of each thread. Thus, a fast computation of panoramic images is performed on a standard hardware platform, preserving full input image resolution (780x576) at the same time. Displayed on a second clinical monitor, the extended FOV of the image composition promises high potential for surgery assistance.

  6. Fast and accurate auto focusing algorithm based on two defocused images using discrete cosine transform

    NASA Astrophysics Data System (ADS)

    Park, Byung-Kwan; Kim, Sung-Su; Chung, Dae-Su; Lee, Seong-Deok; Kim, Chang-Yeong

    2008-02-01

    This paper describes the new method for fast auto focusing in image capturing devices. This is achieved by using two defocused images. At two prefixed lens positions, two defocused images are taken and defocused blur levels in each image are estimated using Discrete Cosine Transform (DCT). These DCT values can be classified into distance from the image capturing device to main object, so we can make distance vs. defocused blur level classifier. With this classifier, relation between two defocused blur levels can give the device the best focused lens step. In the case of ordinary auto focusing like Depth from Focus (DFF), it needs several defocused images and compares high frequency components in each image. Also known as hill-climbing method, the process requires about half number of images in all focus lens steps for focusing in general. Since this new method requires only two defocused images, it can save lots of time for focusing or reduce shutter lag time. Compared to existing Depth from Defocus (DFD) which uses two defocused images, this new algorithm is simple and accurate as DFF method. Because of this simplicity and accuracy, this method can also be applied to fast 3D depth map construction.

  7. Hybrid-dual-fourier tomographic algorithm for a fast three-dimensionial optical image reconstruction in turbid media

    NASA Technical Reports Server (NTRS)

    Alfano, Robert R. (Inventor); Cai, Wei (Inventor)

    2007-01-01

    A reconstruction technique for reducing computation burden in the 3D image processes, wherein the reconstruction procedure comprises an inverse and a forward model. The inverse model uses a hybrid dual Fourier algorithm that combines a 2D Fourier inversion with a 1D matrix inversion to thereby provide high-speed inverse computations. The inverse algorithm uses a hybrid transfer to provide fast Fourier inversion for data of multiple sources and multiple detectors. The forward model is based on an analytical cumulant solution of a radiative transfer equation. The accurate analytical form of the solution to the radiative transfer equation provides an efficient formalism for fast computation of the forward model.

  8. Analysis of Tracking Measuring Method of Focus Cabin of Five-hundred-meter Aperture Spherical radio Telescope(FAST)

    NASA Astrophysics Data System (ADS)

    Yuan, Hui; Zhu, Lichun

    2015-08-01

    FAST (Five-hundred-meter Aperture Spherical radio Telescope) project is one of the Chinese mega-Science Projects to build the largest single dish radio telescope in the world. FAST has three outstanding innovation aspects: in the karst depression which is large to host the 500-meter telescope, an active main reflector correcting for spherical aberration on the ground to achieve a full polarization is being built, the light-weight feed focus cabin in which a parallel robot as a secondary adjustable system to move with high precision is driven by cables and servomechanism plus. The part of main reflector which is illuminated by the feed is continually adjusted to fit the paraboloid of revolution in real time when tracking the radio source. How to get high precise real-time feedback data of moving focus cabin’s position when tracking the source is one of the crucial problems for the astronomical observation.At present 24 steady basis pillars for measurement whose position coordinates are already known, have been built in the construction field of FAST. Total stations will be installed on one of those pillars, and prisms will be installed on focus cabin. The purpose of this study was to assess the accuracy and reliability of two measuring method: the space distance intersection calculation method and polar measuring method. The space distance intersection calculation method is only using multiple measuring distances between three pillars and prism and known coordinates of pillars to calculate the prism’s coordinates, the polar measurement is using the measuring distance and angles to get the prism’s coordinate.

  9. The Impact of Standardized Acuity Assessment and a Fast-Track on Length of Stay in Obstetric Triage: A Quality Improvement Study.

    PubMed

    Smithson, David S; Twohey, Rachel; Watts, Nancy; Gratton, Robert J

    To prospectively assess the impact of a standardized 5-category Obstetrical Triage Acuity Scale (OTAS) and a fast-track for lower-acuity patients on patient flow. Length of stay (LOS) data of women presenting to obstetric triage were abstracted from the electronic medical record prior to (July 1, 2011, to March 30, 2012) and following OTAS implementation (April 1 to December 31, 2012). Following computerized simulation modeling, a fast-track for lower acuity women was implemented (January 1, 2013, to February 28, 2014). Prior to OTAS implementation (8085 visits), the median LOS was 105 (interquartile range [IQR] = 52-178) minutes. Following OTAS implementation (8131 visits), the median LOS decreased to 101 (IQR = 49-175) minutes (P = .04). The LOS did not correlate well with acuity. Simulation modeling predicted that a fast-track for OTAS 4 and 5 patients would reduce the LOS. The LOS for lower-acuity patients in the fast-track decreased to 73 (IQR = 40-140) minutes (P = .005). In addition, the overall LOS (12 576 visits) decreased to 98 (IQR = 47-172) minutes (6.9% reduction; P < .001). Standardized assessment of acuity and a fast-track for lower acuity pregnant women decreased the overall LOS and the LOS of lower-acuity patients.

  10. Simultaneous multi-vehicle detection and tracking framework with pavement constraints based on machine learning and particle filter algorithm

    NASA Astrophysics Data System (ADS)

    Wang, Ke; Huang, Zhi; Zhong, Zhihua

    2014-11-01

    Due to the large variations of environment with ever-changing background and vehicles with different shapes, colors and appearances, to implement a real-time on-board vehicle recognition system with high adaptability, efficiency and robustness in complicated environments, remains challenging. This paper introduces a simultaneous detection and tracking framework for robust on-board vehicle recognition based on monocular vision technology. The framework utilizes a novel layered machine learning and particle filter to build a multi-vehicle detection and tracking system. In the vehicle detection stage, a layered machine learning method is presented, which combines coarse-search and fine-search to obtain the target using the AdaBoost-based training algorithm. The pavement segmentation method based on characteristic similarity is proposed to estimate the most likely pavement area. Efficiency and accuracy are enhanced by restricting vehicle detection within the downsized area of pavement. In vehicle tracking stage, a multi-objective tracking algorithm based on target state management and particle filter is proposed. The proposed system is evaluated by roadway video captured in a variety of traffics, illumination, and weather conditions. The evaluating results show that, under conditions of proper illumination and clear vehicle appearance, the proposed system achieves 91.2% detection rate and 2.6% false detection rate. Experiments compared to typical algorithms show that, the presented algorithm reduces the false detection rate nearly by half at the cost of decreasing 2.7%-8.6% detection rate. This paper proposes a multi-vehicle detection and tracking system, which is promising for implementation in an on-board vehicle recognition system with high precision, strong robustness and low computational cost.

  11. A fast image encryption algorithm based on only blocks in cipher text

    NASA Astrophysics Data System (ADS)

    Wang, Xing-Yuan; Wang, Qian

    2014-03-01

    In this paper, a fast image encryption algorithm is proposed, in which the shuffling and diffusion is performed simultaneously. The cipher-text image is divided into blocks and each block has k ×k pixels, while the pixels of the plain-text are scanned one by one. Four logistic maps are used to generate the encryption key stream and the new place in the cipher image of plain image pixels, including the row and column of the block which the pixel belongs to and the place where the pixel would be placed in the block. After encrypting each pixel, the initial conditions of logistic maps would be changed according to the encrypted pixel's value; after encrypting each row of plain image, the initial condition would also be changed by the skew tent map. At last, it is illustrated that this algorithm has a faster speed, big key space, and better properties in withstanding differential attacks, statistical analysis, known plaintext, and chosen plaintext attacks.

  12. Fast Detection Anti-Collision Algorithm for RFID System Implemented On-Chip

    NASA Astrophysics Data System (ADS)

    Sampe, Jahariah; Othman, Masuri

    This study presents a proposed Fast Detection Anti-Collision Algorithm (FDACA) for Radio Frequency Identification (RFID) system. Our proposed FDACA is implemented on-chip using Application Specific Integrated Circuit (ASIC) technology and the algorithm is based on the deterministic anti-collision technique. The FDACA is novel in terms of a faster identification by reducing the number of iterations during the identification process. The primary FDACA also reads the identification (ID) bits at once regardless of its length. It also does not require the tags to remember the instructions from the reader during the communication process in which the tags are treated as address carrying devices only. As a result simple, small, low cost and memoryless tags can be produced. The proposed system is designed using Verilog HDL. The system is simulated using Modelsim XE II and synthesized using Xilinx Synthesis Technology (XST). The system is implemented in hardware using Field Programmable Grid Array (FPGA) board for real time verification. From the verification results it can be shown that the FDACA system enables to identify the tags without error until the operating frequency of 180 MHZ. Finally the FDACA system is implemented on chip using 0.18 μm Library, Synopsys Compiler and tools. From the resynthesis results it shows that the identification rate of the proposed FDACA system is 333 Mega tags per second with the power requirement of 3.451 mW.

  13. A fast pyramid matching algorithm for infrared object detection based on region covariance descriptor

    NASA Astrophysics Data System (ADS)

    Yin, Li-hua; Wang, Xiao; Xie, Jiang-rong

    2016-11-01

    In order to achieve the purpose of infrared object detection, two phases are essential, including feature selection and matching strategy. Good Features should be discriminative, robust and easy to compute. The matching strategy affects the accuracy and efficiency of matching. In the first stage, instead of the joint distribution of the image statistics, we use region covariance descriptor and calculate region covariance using integral images. The idea presented here is more general than the image sums or histograms, which were already published before. In the second feature matching stage, we describe a new and fast pyramid matching algorithm under the distance metric, which performed extremely rapidly than a brute force search. We represent an object with five covariance matrices of the image features computed inside the object region. Instead of brute force matching, we constructed the image pyramid and decomposed the source image and object image into several levels, which included different image resolutions. After the completion of coarse match, fine-match is essential. The performance of region covariance descriptor is superior to other methods, and the pyramid matching algorithm performs extremely rapidly and accurately, as it is shown, and the large rotations and illumination changes are also absorbed by the covariance matrix.

  14. Character-embedded watermarking algorithm using the fast Hadamard transform for satellite images

    NASA Astrophysics Data System (ADS)

    Ho, Anthony T. S.; Shen, Jun; Tan, Soon H.

    2003-01-01

    In this paper, a character-embedded watermarking algorithm is proposed for copyright protection of satellite images based on the Fast Hadamard transform (FHT). By using a private-key watermarking scheme, the watermark can be retrieved without using the original image. To increase the invisibility of the watermark, a visual model based on original image characteristics, such as edges and textures are incorporated to determine the watermarking strength factor. This factor determines the strength of watermark bits embedded according to the region complexity of the image. Detailed or coarse areas will be assigned more strength and smooth areas with less strength. Error correction coding is also used to increase the reliability of the information bits. A post-processing technique based on log-polar mapping is incorporated to enhance the robustness against geometric distortion attacks. Experiments showed that the proposed watermarking scheme was able to survive more than 70% of attacks from a common benchmarking tool called Stirmark, and about 90% against Checkmark non-geometric attacks. These attacks were performed on a number of SPOT images of size 512×512×8bit embedded with 32 characters. The proposed FHT algorithm also has the advantage of easy software and hardware implementation as well as speed, comparing to other orthogonal transforms such as Cosine, Fourier and wavelet transform.

  15. Fast Track Teacher Education: A Review of the Research Literature on "Teach For All" Schemes

    ERIC Educational Resources Information Center

    McConney, Andrew; Price, Anne; Woods-McConney, Amanda

    2012-01-01

    This review of the research literature was commissioned by the New Zealand Post-Primary Teachers Association (PPTA) Te Wehengarua as a means of informing the decision-making of the Association and its members about the Teach For All (TFA) scheme seeking to prepare teachers for New Zealand's schools. The systematic review is about fast track…

  16. Load Balancing and Data Locality in the Parallelization of the Fast Multipole Algorithm

    NASA Astrophysics Data System (ADS)

    Banicescu, Ioana

    Scientific problems are often irregular, large and computationally intensive. Efficient parallel implementations of algorithms that are employed in finding solutions to these problems play an important role in the development of science. This thesis studies the parallelization of a certain class of irregular scientific problems, the N -body problem, using a classical hierarchical algorithm: the Fast Multipole Algorithm (FMA). Hierarchical N-body algorithms in general, and the FMA in particular, are amenable to parallel execution. However, performance gains are difficult to obtain, due to load imbalances that are primarily caused by the irregular distribution of bodies and of computation domains. Understanding application characteristics is essential for obtaining high performance implementations on parallel machines. After surveying the available parallelism in the FMA, we address the problem of exploiting this parallelism with partitioning and scheduling techniques that optimally map it onto a parallel machine, the KSR1. The KSR1 is a parallel shared address-space machine with a hierarchical cache-only architecture. The tension between maintaining data locality and balancing processor loads requires a scheduling scheme that combines static techniques (that exploit data locality) with dynamic techniques (that improve load balancing). An effective combined scheduling scheme that balances processor loads and maintains locality, by exploiting self-similarity properties of fractals, is Fractiling. Fractiling is based on a probabilistic analysis. It thus accommodates load imbalances caused by predictable events (such as irregular data) as well as unpredictable events (such as data access latency). Fractiling adapts to algorithmic and system induced load imbalances while maximizing data locality. We used Fractiling to schedule a parallel FMA on the KSR1. Our parallel 2-d and 3-d FMA implementations were run using uniform and nonuniform data set distributions under a

  17. A fast algorithm based on the domain decomposition method for scattering analysis of electrically large objects

    NASA Astrophysics Data System (ADS)

    Yin, Lei; Hong, Wei

    2002-01-01

    By combining the finite difference (FD) method with the domain decomposition method (DDM), a fast and rigorous algorithm is presented in this paper for the scattering analysis of extremely large objects. Unlike conventional methods, such as the method of moments (MOM) and FD method, etc., the new algorithm decomposes an original large domain into small subdomains and chooses the most efficient method to solve the electromagnetic (EM) equations on each subdomain individually. Therefore the computational complexity and scale are substantially reduced. The iterative procedure of the algorithm and the implementation of virtual boundary conditions are discussed in detail. During scattering analysis of an electrically large cylinder, the conformal band computational domain along the circumference of the cylinder is decomposed into sections, which results in a series of band matrices with very narrow band. Compared with the traditional FD method, it decreases the consumption of computer memory and CPU time from O(N2) to O(N/m) and O(N), respectively, where m is the number of subdomains and Nis the number of nodes or unknowns. Furthermore, this method can be easily applied for the analysis of arbitrary shaped cylinders because the subdomains can be divided into any possible form. On the other hand, increasing the number of subdomains will hardly increase the computing time, which makes it possible to analyze the EM scattering problems of extremely large cylinders only on a PC. The EM scattering by two-dimensional cylinders with maximum perimeter of 100,000 wavelengths is analyzed. Moreover, this method is very suitable for parallel computation, which can further promote the computational efficiency.

  18. A fast algorithm for voxel-based deterministic simulation of X-ray imaging

    NASA Astrophysics Data System (ADS)

    Li, Ning; Zhao, Hua-Xia; Cho, Sang-Hyun; Choi, Jung-Gil; Kim, Myoung-Hee

    2008-04-01

    Deterministic method based on ray tracing technique is known as a powerful alternative to the Monte Carlo approach for virtual X-ray imaging. The algorithm speed is a critical issue in the perspective of simulating hundreds of images, notably to simulate tomographic acquisition or even more, to simulate X-ray radiographic video recordings. We present an algorithm for voxel-based deterministic simulation of X-ray imaging using voxel-driven forward and backward perspective projection operations and minimum bounding rectangles (MBRs). The algorithm is fast, easy to implement, and creates high-quality simulated radiographs. As a result, simulated radiographs can typically be obtained in split seconds with a simple personal computer. Program summaryProgram title: X-ray Catalogue identifier: AEAD_v1_0 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AEAD_v1_0.html Program obtainable from: CPC Program Library, Queen's University, Belfast, N. Ireland Licensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.html No. of lines in distributed program, including test data, etc.: 416 257 No. of bytes in distributed program, including test data, etc.: 6 018 263 Distribution format: tar.gz Programming language: C (Visual C++) Computer: Any PC. Tested on DELL Precision 380 based on a Pentium D 3.20 GHz processor with 3.50 GB of RAM Operating system: Windows XP Classification: 14, 21.1 Nature of problem: Radiographic simulation of voxelized objects based on ray tracing technique. Solution method: The core of the simulation is a fast routine for the calculation of ray-box intersections and minimum bounding rectangles, together with voxel-driven forward and backward perspective projection operations. Restrictions: Memory constraints. There are three programs in all. A. Program for test 3.1(1): Object and detector have axis-aligned orientation; B. Program for test 3.1(2): Object in arbitrary orientation; C. Program for test 3.2: Simulation of X-ray video

  19. A Comparative Study of Postoperative Pulmonary Complications Using Fast Track Regimen and Conservative Analgesic Treatment: A Randomized Clinical Trial

    PubMed Central

    Aghdam, Babak Abri; Golzari, Samad Eslam Jamal; Moghadaszadeh, Majid

    2011-01-01

    Background Postoperative pulmonary complications and pain are important causes of postoperative morbidity following thoracotomy. This study aimed to compare the effects of fast track and conservative treatment regimens on patients undergoing thoracotomy. Materials and Methods In this randomized controlled clinical trial, we recruited 60 patients admitted to the thoracic ICU of Imam Reza Hospital in two matched groups of 30 patients each. Group 1 patients received fast track regimen randomly; whereas, group 2 cases randomly received conservative analgesic regimen after thoracotomy and pulmonary resection. The outcome was determined based on the incidence of pulmonary complications and reduction of post-thoracotomy pain in all patients with forced expiratory volume in one second (FEV1) <75% predicted value which was measured while the patients were in ICU. The length of ICU stay, thoracotomy pain, morbidity, pulmonary complications and mortality were compared in two groups. Results A total of 60 patients, 45 (75%) males and 15(25%) females with ASA class I-III were recruited in this study. Postoperative pulmonary complications were observed in 5 (16.7%) patients in group 1 versus 17 (56.7%) patients in group 2. There were statistically significant differences in development of postoperative pulmonary complications such as atelectasis and prolonged air leak between both groups (P< 0.001 and P = 0.003). There was also a statistically significant difference in the rate of preoperative FEV1 (p = 0.001) and ASA scoring (p = 0.01) and value of FEV1 < 75% predicted in the two groups. The difference in length of ICU stay in two groups was statistically significant (P= 0.003 and P = 0.017 in FEV1 < 75% group). Four patients in group 1 and 9 patients in group 2 had FEV1reduced to less than 75% of predicted value (p = 0.03). Conclusion Using fast track regimen reduced postoperative pain and incidence of some pulmonary complications significantly when compared to the

  20. Finite interval tracking algorithm for nonlinear multi-agent systems with communication delays

    NASA Astrophysics Data System (ADS)

    Dong, Lijing; Chai, Senchun; Zhang, Baihai; Li, Xiangshun; Kiong Nguang, Sing

    2016-11-01

    We propose an iterative learning control (ILC) tracking strategy to solve the tracking problem of multi-agent systems with nonlinear dynamics and time-varying communication delays. The distributed tracking strategy, in which each tracking agent only utilises its own and neighbours' information, enables the tracking agents successfully track a maneuvering target in a finite time interval although with presence of time delays. Compared with the existing related work, the quantitative relationship between the boundary of tracking errors and the estimation of time delays is derived. Furthermore, in many practical control problems, identical initialisation condition may not be satisfied, which is called initial-shift problem. Hence, a forgetting factor is introduced to deal with that problem. It is proved that the presented results are effective via conducting numerical examples.

  1. A fast 3-D object recognition algorithm for the vision system of a special-purpose dexterous manipulator

    NASA Technical Reports Server (NTRS)

    Hung, Stephen H. Y.

    1989-01-01

    A fast 3-D object recognition algorithm that can be used as a quick-look subsystem to the vision system for the Special-Purpose Dexterous Manipulator (SPDM) is described. Global features that can be easily computed from range data are used to characterize the images of a viewer-centered model of an object. This algorithm will speed up the processing by eliminating the low level processing whenever possible. It may identify the object, reject a set of bad data in the early stage, or create a better environment for a more powerful algorithm to carry the work further.

  2. A prospective study to assess the implementation of a fast-track system to meet the two-week target for colorectal cancer in Somerset.

    PubMed

    Davies, R. J.; Ewings, P.; Welbourn, R.; Collins, C.; Kennedy, R.; Royle, C.

    2002-01-01

    OBJECTIVE: This prospective study assesses the introduction of a fast-track referral system for patients with suspected colorectal cancer. PATIENTS AND METHODS: The referral system was initiated in Yeovil District Hospital and Taunton and Somerset Hospital using six screening criteria to select high-risk patients. Data on all high-risk patients from 1 November 1999 to 30 April 2000 was recorded prospectively. Patients with proven colorectal cancer diagnosed between 1 November 1998 and 30 April 1999 have been identified for comparison. RESULTS: There were 158 new cases of colorectal cancer in total (111 elective, 47 emergency). 59 cases of colorectal cancer were diagnosed from 433 fast-track referrals (53% of total elective cases). Median time from referral to diagnosis in the fast-track group was 11 days vs. 32.5 days for nonfast-track elective patients (P < 0.001). Median time from referral to diagnosis for all elective cases was 17 days vs. 38.5 days for patients presenting one year earlier (P < 0.001). 75% of fast-track patients were diagnosed with colorectal cancer within two weeks, compared with 17% of nonfast-track elective patients (P < 0.001). The proportion of emergency admissions was reduced from 40% to 30% (P=0.07) following the introduction of this system. CONCLUSION: Data from the first six months reveal that over half of the elective cases of colorectal cancer were diagnosed within the fast-track system. The median time from referral to diagnosis in these patients was within two weeks and there has been a significant reduction in the time to diagnosis associated with the introduction of this service.

  3. Indirect Effects of the Fast Track Intervention on Conduct Disorder Symptoms and Callous-Unemotional Traits: Distinct Pathways Involving Discipline and Warmth

    PubMed Central

    Pasalich, Dave S.; Witkiewitz, Katie; McMahon, Robert J.; Pinderhughes, Ellen E.

    2016-01-01

    Little is known about intervening processes that explain how prevention programs improve particular youth antisocial outcomes. We examined whether parental harsh discipline and warmth in childhood differentially account for Fast Track intervention effects on conduct disorder (CD) symptoms and callous-unemotional (CU) traits in early adolescence. Participants included 891 high-risk kindergarteners (69% male; 51% African American) from urban and rural United States communities who were randomized into either the Fast Track intervention (n = 445) or non-intervention control (n = 446) groups. The 10-year intervention included parent management training and other services (e.g., social skills training, universal classroom curriculum) targeting various risk factors for the development of conduct problems. Harsh discipline (Grades 1 through 3) and warmth (Grades 1 and 2) were measured using parent responses to vignettes and direct observations of parent-child interaction, respectively. Parents reported on children’s CD symptoms in Grade 6 and CU traits in Grade 7. Results demonstrated indirect effects of the Fast Track intervention on reducing risk for youth antisocial outcomes. That is, Fast Track was associated with lower scores on harsh discipline, which in turn predicted decreased levels of CD symptoms. In addition, Fast Track was associated with higher scores on warmth, which in turn predicted reduced levels of CU traits. Our findings inform developmental and intervention models of youth antisocial behavior by providing evidence for the differential role of harsh discipline and warmth in accounting for indirect effects of Fast Track on CD symptoms versus CU traits, respectively. PMID:26242993

  4. Indirect Effects of the Fast Track Intervention on Conduct Disorder Symptoms and Callous-Unemotional Traits: Distinct Pathways Involving Discipline and Warmth.

    PubMed

    Pasalich, Dave S; Witkiewitz, Katie; McMahon, Robert J; Pinderhughes, Ellen E

    2016-04-01

    Little is known about intervening processes that explain how prevention programs improve particular youth antisocial outcomes. We examined whether parental harsh discipline and warmth in childhood differentially account for Fast Track intervention effects on conduct disorder (CD) symptoms and callous-unemotional (CU) traits in early adolescence. Participants included 891 high-risk kindergarteners (69% male; 51% African American) from urban and rural United States communities who were randomized into either the Fast Track intervention (n = 445) or non-intervention control (n = 446) groups. The 10-year intervention included parent management training and other services (e.g., social skills training, universal classroom curriculum) targeting various risk factors for the development of conduct problems. Harsh discipline (Grades 1 to 3) and warmth (Grades 1 and 2) were measured using parent responses to vignettes and direct observations of parent-child interaction, respectively. Parents reported on children's CD symptoms in Grade 6 and CU traits in Grade 7. Results demonstrated indirect effects of the Fast Track intervention on reducing risk for youth antisocial outcomes. That is, Fast Track was associated with lower scores on harsh discipline, which in turn predicted decreased levels of CD symptoms. In addition, Fast Track was associated with higher scores on warmth, which in turn predicted reduced levels of CU traits. Our findings inform developmental and intervention models of youth antisocial behavior by providing evidence for the differential role of harsh discipline and warmth in accounting for indirect effects of Fast Track on CD symptoms versus CU traits, respectively.

  5. Research on fast Fourier transforms algorithm of huge remote sensing image technology with GPU and partitioning technology.

    PubMed

    Yang, Xue; Li, Xue-You; Li, Jia-Guo; Ma, Jun; Zhang, Li; Yang, Jan; Du, Quan-Ye

    2014-02-01

    Fast Fourier transforms (FFT) is a basic approach to remote sensing image processing. With the improvement of capacity of remote sensing image capture with the features of hyperspectrum, high spatial resolution and high temporal resolution, how to use FFT technology to efficiently process huge remote sensing image becomes the critical step and research hot spot of current image processing technology. FFT algorithm, one of the basic algorithms of image processing, can be used for stripe noise removal, image compression, image registration, etc. in processing remote sensing image. CUFFT function library is the FFT algorithm library based on CPU and FFTW. FFTW is a FFT algorithm developed based on CPU in PC platform, and is currently the fastest CPU based FFT algorithm function library. However there is a common problem that once the available memory or memory is less than the capacity of image, there will be out of memory or memory overflow when using the above two methods to realize image FFT arithmetic. To address this problem, a CPU and partitioning technology based Huge Remote Fast Fourier Transform (HRFFT) algorithm is proposed in this paper. By improving the FFT algorithm in CUFFT function library, the problem of out of memory and memory overflow is solved. Moreover, this method is proved rational by experiment combined with the CCD image of HJ-1A satellite. When applied to practical image processing, it improves effect of the image processing, speeds up the processing, which saves the time of computation and achieves sound result.

  6. Using a new algorithm to track mixed-Rossby gravity waves (MRG) waves in reanalysis data

    NASA Astrophysics Data System (ADS)

    Au-Yeung, A. Y. M.; Tam, C. Y.

    2015-12-01

    A new algorithm has been developed to track westward travelling mixed-Rossby gravity waves (MRG) waves in the western Pacific based on the theoretical meridional wind structure stated in the shallow water equation (SWE) solutions. Applied to space-time filtered (period=3 to 8 days and wavenumber =-20 to 0), asymmetric meridional wind data at the 850hPa level from the NCEP CFS reanalysis, the algorithm finds locations with Gaussian-shaped meridional wind structure stated in SWE solutions through space and time. Two groups of MRG waves were found: one with higher wavenumber (11) and another one with lower-wavenumber (6). Moreover, the MRG waves show very different dispersive properties and occurrence behavior in the western and eastern equatorial Pacific. While both groups appear in the western Pacific, mainly 6 waves were found in the eastern Pacific. The fact that both 6 and 11 waves appear in the western Pacific agrees with past discussions on the co-existence of MRG waves and tropical-disturbance type (TD-type) waves. Also, the high wavenumber wave activities mainly appear west of the dateline, meaning that some triggering process may have taken place there. Northwestward wave train movement was found west of 140E in the low-level wind composites. On the other hand, negative correlation between meridional wind and temperature (negative) found in the vertical composites indicates downward vertical wave activity flux prior to the occurrences of MRG waves. Finally, in the western Pacific, kinetic energy energetics suggests that energy source of transient eddies is from the confluent background flow and also the zonal wind shear terms in the western Pacific. Overall, our method provides a way to identify the MRG waves instantaneously; in contrast, most of the methods employed in the past (e.g., spectral analysis or lag correlation/regression) are based on aggregates of data and they can only examine wave properties averaged over a certain period of time. Since MRG

  7. An accelerated photo-magnetic imaging reconstruction algorithm based on an analytical forward solution and a fast Jacobian assembly method

    NASA Astrophysics Data System (ADS)

    Nouizi, F.; Erkol, H.; Luk, A.; Marks, M.; Unlu, M. B.; Gulsen, G.

    2016-10-01

    We previously introduced photo-magnetic imaging (PMI), an imaging technique that illuminates the medium under investigation with near-infrared light and measures the induced temperature increase using magnetic resonance thermometry (MRT). Using a multiphysics solver combining photon migration and heat diffusion, PMI models the spatiotemporal distribution of temperature variation and recovers high resolution optical absorption images using these temperature maps. In this paper, we present a new fast non-iterative reconstruction algorithm for PMI. This new algorithm uses analytic methods during the resolution of the forward problem and the assembly of the sensitivity matrix. We validate our new analytic-based algorithm with the first generation finite element method (FEM) based reconstruction algorithm previously developed by our team. The validation is performed using, first synthetic data and afterwards, real MRT measured temperature maps. Our new method accelerates the reconstruction process 30-fold when compared to a single iteration of the FEM-based algorithm.

  8. [Optimization of the management of acute heart failure. New concept of fast-track].

    PubMed

    Andrieu, S; Jouve, B; Pansieri, M

    2016-11-01

    The acute heart failure generates a very important number of hospitalizations for a high cost. A recent reflection on optimizing its management is ongoing, based on the fastest management in the emergency department, with a distinction between which patient should remain and who returns at home, and under what conditions, allowing to limit the number of hospitalizations. It will require a reorganization of emergency department and updating of decision algorithms and new guidelines of care.

  9. The impact of a fast track area on quality and effectiveness outcomes: A Middle Eastern emergency department perspective

    PubMed Central

    Devkaran, Subashnie; Parsons, Howard; Van Dyke, Murray; Drennan, Jonathan; Rajah, Jaishen

    2009-01-01

    Background Emergency department (ED) overcrowding is a ubiquitous problem with serious public health implications. The fast track area is a novel method which aims to reduce waiting time, patient dissatisfaction and morbidity. |The study objective was to determine the impact of a fast track area (FTA) on both effectiveness measures (i.e. waiting times [WT] and length of stay [LOS]) and quality measures (i.e. LWBS rates and mortality rates) in non-urgent patients. The secondary objective was to assess if a FTA negatively impacted on urgent patients entering the ED. Methods The study took place in a 500 bed, urban, tertiary care hospital in Abu Dhabi, United Arab Emirates. This was a quasi-experimental, which examined the impact of a FTA on a pre-intervention control group (January 2005) (n = 4,779) versus a post-intervention study group (January 2006) (n = 5,706). Results Mean WTs of Canadian Triage Acuity Scale (CTAS) 4 patients decreased by 22 min (95% CI 21 min to 24 min, P < 0.001). Similarly, mean WTs of CTAS 5 patients decreased by 28 min (95% CI 19 min to 37 min, P < 0.001) post FTA. The mean WTs of urgent patients (CTAS 2/3) were also significantly reduced after the FTA was opened (P < 0.001). The LWBS rate was reduced from 4.7% to 0.7% (95% CI 3.37 to 4.64; P < 0.001). Opening a FTA had no significant impact on mortality rates (P = 0.88). Conclusion The FTA improved ED effectiveness (WTs and LOS) and quality measures (LWBS rates) whereas mortality rate remained unchanged. PMID:19534787

  10. Which patient characteristics influence length of hospital stay after primary total hip arthroplasty in a 'fast-track' setting?

    PubMed

    den Hartog, Y M; Mathijssen, N M C; Hannink, G; Vehmeijer, S B W

    2015-01-01

    After implementation of a 'fast-track' rehabilitation protocol in our hospital, mean length of hospital stay for primary total hip arthroplasty decreased from 4.6 to 2.9 nights for unselected patients. However, despite this reduction there was still a wide range across the patients' hospital duration. The purpose of this study was to identify which specific patient characteristics influence length of stay after successful implementation of a 'fast-track' rehabilitation protocol. A total of 477 patients (317 female and 160 male, mean age 71.0 years; 39.3 to 92.6, mean BMI 27.0 kg/m(2);18.8 to 45.2) who underwent primary total hip arthroplasty between 1 February 2011 and 31 January 2013, were included in this retrospective cohort study. A length of stay greater than the median was considered as an increased duration. Logistic regression analyses were performed to identify potential factors associated with increased durations. Median length of stay was two nights (interquartile range 1), and the mean length of stay 2.9 nights (1 to 75). In all, 266 patients had a length of stay ≤ two nights. Age (odds ratio (OR) 2.46; 95% confidence intervals (CI) 1.72 to 3.51; p < 0.001), living situation (alone vs living together with cohabitants, OR 2.09; 95% CI 1.33 to 3.30; p = 0.002) and approach (anterior approach vs lateral, OR 0.29; 95% CI 0.19 to 0.46; p < 0.001) (posterolateral approach vs lateral, OR 0.24; 95% CI 0.10 to 0.55; p < 0.001) were factors that were significantly associated with increased length of stay in the multivariable logistic regression model.

  11. Evaluation of the influence of pulmonary hypertension in ultra-fast-track anesthesia technique in adult patients undergoing cardiac surgery

    PubMed Central

    da Silva, Paulo Sérgio; Cartacho, Márcio Portugal Trindade; de Castro, Casimiro Cardoso; Salgado Filho, Marcello Fonseca; Brandão, Antônio Carlos Aguiar

    2015-01-01

    Objective To evaluate the influence of pulmonary hypertension in the ultra-fast-track anesthesia technique in adult cardiac surgery. Methods A retrospective study. They were included 40 patients divided into two groups: GI (without pulmonary hypertension) and GII (with pulmonary hypertension). Based on data obtained by transthoracic echocardiography. We considered as the absence of pulmonary hypertension: a pulmonary artery systolic pressure (sPAP) <36 mmHg, with tricuspid regurgitation velocity <2.8 m/s and no additional echocardiographic signs of PH, and PH as presence: a sPAP >40 mmHg associated with additional echocardiographic signs of PH. It was established as influence of pulmonary hypertension: the impossibility of extubation in the operating room, the increase in the time interval for extubation and reintubation the first 24 hours postoperatively. Univariate and multivariate analyzes were performed when necessary. Considered significant a P value <0.05. Results The GI was composed of 21 patients and GII for 19. All patients (100%) were extubated in the operating room in a medium time interval of 17.58±8.06 min with a median of 18 min in GII and 17 min in GI. PH did not increase the time interval for extubation (P=0.397). It required reintubation of 2 patients in GII (5% of the total), without statistically significant as compared to GI (P=0.488). Conclusion In this study, pulmonary hypertension did not influence on ultra-fast-track anesthesia in adult cardiac surgery. PMID:27163419

  12. FastTagger: an efficient algorithm for genome-wide tag SNP selection using multi-marker linkage disequilibrium

    PubMed Central

    2010-01-01

    Background Human genome contains millions of common single nucleotide polymorphisms (SNPs) and these SNPs play an important role in understanding the association between genetic variations and human diseases. Many SNPs show correlated genotypes, or linkage disequilibrium (LD), thus it is not necessary to genotype all SNPs for association study. Many algorithms have been developed to find a small subset of SNPs called tag SNPs that are sufficient to infer all the other SNPs. Algorithms based on the r2 LD statistic have gained popularity because r2 is directly related to statistical power to detect disease associations. Most of existing r2 based algorithms use pairwise LD. Recent studies show that multi-marker LD can help further reduce the number of tag SNPs. However, existing tag SNP selection algorithms based on multi-marker LD are both time-consuming and memory-consuming. They cannot work on chromosomes containing more than 100 k SNPs using length-3 tagging rules. Results We propose an efficient algorithm called FastTagger to calculate multi-marker tagging rules and select tag SNPs based on multi-marker LD. FastTagger uses several techniques to reduce running time and memory consumption. Our experiment results show that FastTagger is several times faster than existing multi-marker based tag SNP selection algorithms, and it consumes much less memory at the same time. As a result, FastTagger can work on chromosomes containing more than 100 k SNPs using length-3 tagging rules. FastTagger also produces smaller sets of tag SNPs than existing multi-marker based algorithms, and the reduction ratio ranges from 3%-9% when length-3 tagging rules are used. The generated tagging rules can also be used for genotype imputation. We studied the prediction accuracy of individual rules, and the average accuracy is above 96% when r2 ≥ 0.9. Conclusions Generating multi-marker tagging rules is a computation intensive task, and it is the bottleneck of existing multi-marker based tag

  13. A Fast parallel tridiagonal algorithm for a class of CFD applications

    NASA Technical Reports Server (NTRS)

    Moitra, Stuti; Sun, Xian-He

    1996-01-01

    The parallel diagonal dominant (PDD) algorithm is an efficient tridiagonal solver. This paper presents for study a variation of the PDD algorithm, the reduced PDD algorithm. The new algorithm maintains the minimum communication provided by the PDD algorithm, but has a reduced operation count. The PDD algorithm also has a smaller operation count than the conventional sequential algorithm for many applications. Accuracy analysis is provided for the reduced PDD algorithm for symmetric Toeplitz tridiagonal (STT) systems. Implementation results on Langley's Intel Paragon and IBM SP2 show that both the PDD and reduced PDD algorithms are efficient and scalable.

  14. A fast video clip retrieval algorithm based on VA-file

    NASA Astrophysics Data System (ADS)

    Liu, Fangjie; Dong, DaoGuo; Miao, Xiaoping; Xue, XiangYang

    2003-12-01

    Video clip retrieval is a significant research topic of content-base multimedia retrieval. Generally, video clip retrieval process is carried out as following: (1) segment a video clip into shots; (2) extract a key frame from each shot as its representative; (3) denote every key frame as a feature vector, and thus a video clip can be denoted as a sequence of feature vectors; (4) retrieve match clip by computing the similarity between the feature vector sequence of a query clip and the feature vector sequence of any clip in database. To carry out fast video clip retrieval the index structure is indispensable. According to our literature survey, S2-tree [17] is the one and only index structure having been applied to support video clip retrieval, which combines the characteristics of both X-tree and Suffix-tree and converts the series vectors retrieval to string matching. But S2-tree structure will not be applicable if the feature vector's dimension is beyond 20, because the X-tree itself cannot be used to sustain similarity query effectively when dimensions of vectors are beyond 20. Furthermore, it cannot support flexible similarity definitions between two vector sequences. VA-file represents the vector approximately by compressing the original data and it maintains the original order when representing vectors in a sequence, which is a very valuable merit for vector sequences matching. In this paper, a new video clip similarity model as well as video clip retrieval algorithm based on VA-File are proposed. The experiments show that our algorithm incredibly shortened the retrieval time compared to sequential scanning without index structure.

  15. An algorithm for computing the 2D structure of fast rotating stars

    SciTech Connect

    Rieutord, Michel; Espinosa Lara, Francisco; Putigny, Bertrand

    2016-08-01

    Stars may be understood as self-gravitating masses of a compressible fluid whose radiative cooling is compensated by nuclear reactions or gravitational contraction. The understanding of their time evolution requires the use of detailed models that account for a complex microphysics including that of opacities, equation of state and nuclear reactions. The present stellar models are essentially one-dimensional, namely spherically symmetric. However, the interpretation of recent data like the surface abundances of elements or the distribution of internal rotation have reached the limits of validity of one-dimensional models because of their very simplified representation of large-scale fluid flows. In this article, we describe the ESTER code, which is the first code able to compute in a consistent way a two-dimensional model of a fast rotating star including its large-scale flows. Compared to classical 1D stellar evolution codes, many numerical innovations have been introduced to deal with this complex problem. First, the spectral discretization based on spherical harmonics and Chebyshev polynomials is used to represent the 2D axisymmetric fields. A nonlinear mapping maps the spheroidal star and allows a smooth spectral representation of the fields. The properties of Picard and Newton iterations for solving the nonlinear partial differential equations of the problem are discussed. It turns out that the Picard scheme is efficient on the computation of the simple polytropic stars, but Newton algorithm is unsurpassed when stellar models include complex microphysics. Finally, we discuss the numerical efficiency of our solver of Newton iterations. This linear solver combines the iterative Conjugate Gradient Squared algorithm together with an LU-factorization serving as a preconditioner of the Jacobian matrix.

  16. Robust digital image-in-image watermarking algorithm using the fast Hadamard transform

    NASA Astrophysics Data System (ADS)

    Ho, Anthony T. S.; Shen, Jun; Tan, Soon H.

    2003-01-01

    In this paper, we propose a robust image-in-image watermarking algorithm based on the fast Hadamard transform (FHT) for the copyright protection of digital images. Most current research makes use of a normally distributed random vector as a watermark and where the watermark can only be detected by cross-correlating the received coefficients with the watermark generated by secret key and then comparing an experimental threshold value. However, the FHT image-in-image method involves a "blind" watermarking process that retrieves the watermark without the need for an original image present. In the proposed approach, a number of pseudorandom selected 8×8 sub-blocks of original image and a watermark image are decomposed into Hadamard coefficients. To increase the invisibility of the watermark, a visual model based on original image characteristics, such as edges and textures are incorporated to determine the watermarking strength factor. All the AC Hadamard coefficients of watermark image is scaled by the watermarking strength factor and inserted into several middle and high frequency AC components of the Hadamard coefficients from the sub-blocks of original image. To further increase the reliability of the watermarking against the common geometric distortions, such as rotation and scaling, a post-processing technique is proposed. Understanding the type of distortion provides a mean to apply a reversal of the attack on the watermarked image, enabling the restoration to the synchronization of the embedding positions. The performance of the proposed algorithm is evaluated using Stirmark. The experiment uses container image of size 512×512×8bits and the watermark image of size 64×64×8bits. It survives about 60% of all Stirmark attacks. The simplicity of Hadamard transform offers a significant advantage in shorter processing time and ease of hardware implementation than the commonly used DCT and DWT techniques.

  17. Adaptive AFM scan speed control for high aspect ratio fast structure tracking

    SciTech Connect

    Ahmad, Ahmad; Schuh, Andreas; Rangelow, Ivo W.

    2014-10-15

    Improved imaging rates in Atomic Force Microscopes (AFM) are of high interest for disciplines such as life sciences and failure analysis of semiconductor wafers, where the sample topology shows high aspect ratios. Also, fast imaging is necessary to cover a large surface under investigation in reasonable times. Since AFMs are composed of mechanical components, they are associated with comparably low resonance frequencies that undermine the effort to increase the acquisition rates. In particular, high and steep structures are difficult to follow, which causes the cantilever to temporarily loose contact to or crash into the sample. Here, we report on a novel approach that does not affect the scanner dynamics, but adapts the lateral scanning speed of the scanner. The controller monitors the control error signal and, only when necessary, decreases the scan speed to allow the z-piezo more time to react to changes in the sample's topography. In this case, the overall imaging rate can be significantly increased, because a general scan speed trade-off decision is not needed and smooth areas are scanned fast. In contrast to methods trying to increase the z-piezo bandwidth, our method is a comparably simple approach that can be easily adapted to standard systems.

  18. A Fast, Locally Adaptive, Interactive Retrieval Algorithm for the Analysis of DIAL Measurements

    NASA Astrophysics Data System (ADS)

    Samarov, D. V.; Rogers, R.; Hair, J. W.; Douglass, K. O.; Plusquellic, D.

    2010-12-01

    Differential absorption light detection and ranging (DIAL) is a laser-based tool which is used for remote, range-resolved measurement of particular gases in the atmosphere, such as carbon-dioxide and methane. In many instances it is of interest to study how these gases are distributed over a region such as a landfill, factory, or farm. While a single DIAL measurement only tells us about the distribution of a gas along a single path, a sequence of consecutive measurements provides us with information on how that gas is distributed over a region, making DIAL a natural choice for such studies. DIAL measurements present a number of interesting challenges; first, in order to convert the raw data to concentration it is necessary to estimate the derivative along the path of the measurement. Second, as the distribution of gases across a region can be highly heterogeneous it is important that the spatial nature of the measurements be taken into account. Finally, since it is common for the set of collected measurements to be quite large it is important for the method to be computationally efficient. Existing work based on Local Polynomial Regression (LPR) has been developed which addresses the first two issues, but the issue of computational speed remains an open problem. In addition to the latter, another desirable property is to allow user input into the algorithm. In this talk we present a novel method based on LPR which utilizes a variant of the RODEO algorithm to provide a fast, locally adaptive and interactive approach to the analysis of DIAL measurements. This methodology is motivated by and applied to several simulated examples and a study out of NASA Langley Research Center (LaRC) looking at the estimation of aerosol extinction in the atmosphere. A comparison study of our method against several other algorithms is also presented. References Chaudhuri, P., Marron, J.S., Scale-space view of curve estimation, Annals of Statistics 28 (2000) 408-428. Duong, T., Cowling

  19. HaploGrep: a fast and reliable algorithm for automatic classification of mitochondrial DNA haplogroups.

    PubMed

    Kloss-Brandstätter, Anita; Pacher, Dominic; Schönherr, Sebastian; Weissensteiner, Hansi; Binna, Robert; Specht, Günther; Kronenberg, Florian

    2011-01-01

    An ongoing source of controversy in mitochondrial DNA (mtDNA) research is based on the detection of numerous errors in mtDNA profiles that led to erroneous conclusions and false disease associations. Most of these controversies could be avoided if the samples' haplogroup status would be taken into consideration. Knowing the mtDNA haplogroup affiliation is a critical prerequisite for studying mechanisms of human evolution and discovering genes involved in complex diseases, and validating phylogenetic consistency using haplogroup classification is an important step in quality control. However, despite the availability of Phylotree, a regularly updated classification tree of global mtDNA variation, the process of haplogroup classification is still time-consuming and error-prone, as researchers have to manually compare the polymorphisms found in a population sample to those summarized in Phylotree, polymorphism by polymorphism, sample by sample. We present HaploGrep, a fast, reliable and straight-forward algorithm implemented in a Web application to determine the haplogroup affiliation of thousands of mtDNA profiles genotyped for the entire mtDNA or any part of it. HaploGrep uses the latest version of Phylotree and offers an all-in-one solution for quality assessment of mtDNA profiles in clinical genetics, population genetics and forensics. HaploGrep can be accessed freely at http://haplogrep.uibk.ac.at.

  20. EEG-based classification of fast and slow hand movements using Wavelet-CSP algorithm.

    PubMed

    Robinson, Neethu; Vinod, A P; Ang, Kai Keng; Tee, Keng Peng; Guan, Cuntai T

    2013-08-01

    A brain-computer interface (BCI) acquires brain signals, extracts informative features, and translates these features to commands to control an external device. This paper investigates the application of a noninvasive electroencephalography (EEG)-based BCI to identify brain signal features in regard to actual hand movement speed. This provides a more refined control for a BCI system in terms of movement parameters. An experiment was performed to collect EEG data from subjects while they performed right-hand movement at two different speeds, namely fast and slow, in four different directions. The informative features from the data were obtained using the Wavelet-Common Spatial Pattern (W-CSP) algorithm that provided high-temporal-spatial-spectral resolution. The applicability of these features to classify the two speeds and to reconstruct the speed profile was studied. The results for classifying speed across seven subjects yielded a mean accuracy of 83.71% using a Fisher Linear Discriminant (FLD) classifier. The speed components were reconstructed using multiple linear regression and significant correlation of 0.52 (Pearson's linear correlation coefficient) was obtained between recorded and reconstructed velocities on an average. The spatial patterns of the W-CSP features obtained showed activations in parietal and motor areas of the brain. The results achieved promises to provide a more refined control in BCI by including control of movement speed.