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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 parallel tracking algorithm for the muon detector of the CBM experiment at fair

    NASA Astrophysics Data System (ADS)

    Lebedev, A.; Höhne, C.; Kisel, I.; Ososkov, G.

    2010-07-01

    Particle trajectory recognition is an important and challenging task in the Compressed Baryonic Matter (CBM) experiment at the future FAIR accelerator at Darmstadt. The tracking algorithms have to process terabytes of input data produced in particle collisions. Therefore, the speed of the tracking software is extremely important for data analysis. In this contribution, a fast parallel track reconstruction algorithm which uses available features of modern processors is presented. These features comprise a SIMD instruction set (SSE) and multithreading. The first allows one to pack several data items into one register and to operate on all of them in parallel thus achieving more operations per cycle. The second feature enables the routines to exploit all available CPU cores and hardware threads. This parallel version of the tracking algorithm has been compared to the initial serial scalar version which uses a similar approach for tracking. A speed-up factor of 487 was achieved (from 730 to 1.5 ms/event) for a computer with 2 × Intel Core i7 processors at 2.66 GHz.

  4. Fast algorithm for region snake-based segmentation adapted to physical noise models and application to object tracking

    NASA Astrophysics Data System (ADS)

    Chesnaud, Christophe; Refregier, Philippe

    1999-06-01

    Algorithms for object segmentation are crucial in many image processing applications. During past years, active contour models have been widely used for finding the contours of objects. This segmentation strategy is classically edge based in the sense that the snake is driven to fit the maximum of an edge map of the scene. We have recently proposed a region-based snake approach, that can be implemented using a fast algorithm , to segment an object in an image. The algorithms, optimal in the Maximum Likelihood sense, are based on the calculus of the statistics of the inner and the outer regions and can thus be adapted to different kinds of random fields which can describe the input image. In this paper out aim is to study this approach for tracking application in optronic images. We first show the relevance of using a priori information on the statistical laws of the input image in the case of Gaussian statistics which are well adapted to describe optronic images when a whitening preprocessing is used. We will then characterize the performance of the fast algorithm implementation of the used approach and we will apply it to tracking applications. The efficiency of the proposed method will be shown on real image sequences.

  5. Development of a radiation-hardened SRAM with EDAC algorithm for fast readout CMOS pixel sensors for charged particle tracking

    NASA Astrophysics Data System (ADS)

    Wei, X.; Li, B.; Chen, N.; Wang, J.; Zheng, R.; Gao, W.; Wei, T.; Gao, D.; Hu, Y.

    2014-08-01

    CMOS pixel sensors (CPS) are attractive for use in the innermost particle detectors for charged particle tracking due to their good trade-off between spatial resolution, material budget, radiation hardness, and readout speed. With the requirements of high readout speed and high radiation hardness to total ionizing dose (TID) for particle tracking, fast readout CPS are composed by integrating a data compression block and two SRAM IP cores. However, the radiation hardness of the SRAM IP cores is not as high as that of the other parts in CPS, and thus the radiation hardness of the whole CPS chip is lowered. Especially, when CPS are migrated into 0.18-μm processes, the single event upset (SEU) effects should be also considered besides TID and single event latchup (SEL) effects. This paper presents a radiation-hardened SRAM with enhanced radiation hardness to SEU. An error detection and correction (EDAC) algorithm and a bit-interleaving storage strategy are adopted in the design. The prototype design has been fabricated in a 0.18-μm process. The area of the new SRAM is increased 1.6 times as compared with a non-radiation-hardened SRAM due to the integration of EDAC algorithm and the adoption of radiation hardened layout. The access time is increased from 5 ns to 8 ns due to the integration of EDAC algorithm. The test results indicate that the design satisfy requirements of CPS for charged particle tracking.

  6. A Fully Automated Supraglacial lake area and volume Tracking ("FAST") algorithm: development and application using MODIS imagery of West Greenland

    NASA Astrophysics Data System (ADS)

    Williamson, Andrew; Arnold, Neil; Banwell, Alison; Willis, Ian

    2017-04-01

    Supraglacial lakes (SGLs) on the Greenland Ice Sheet (GrIS) influence ice dynamics if draining rapidly by hydrofracture, which can occur in under 24 hours. MODerate-resolution Imaging Spectroradiometer (MODIS) data are often used to investigate SGLs, including calculating SGL area changes through time, but no existing work presents a method that tracks changes in individual (and total) SGL volume in MODIS imagery over a melt season. Here, we present such a method. First, we tested three automated approaches to derive SGL areas from MODIS imagery by comparing calculated areas for the Paakitsoq and Store Glacier regions in West Greenland with areas derived from Landsat-8 (LS8) images. Second, we applied a physically-based depth-calculation algorithm to the pixels within the SGL boundaries from the best performing method, and validated the resultant depths with those calculated using the same method applied to LS8 imagery. Our results indicated that SGL areas are most accurately generated using dynamic thresholding of MODIS band 1 (red) with a 0.640 threshold value. Calculated SGL area, depth and volume values from MODIS were closely comparable to those derived from LS8. The best performing area- and depth-detection methods were then incorporated into a Fully Automated SGL Tracking ("FAST") algorithm that tracks individual SGLs between successive MODIS images. It identified 43 (Paakitsoq) and 19 (Store Glacier) rapidly draining SGLs during 2014, representing 21% and 15% of the respective total SGL populations, including some clusters of rapidly draining SGLs. We found no relationship between the water volumes contained within these rapidly draining SGLs and the ice thicknesses beneath them, indicating that a critical water volume linearly related to ice thickness cannot explain the incidence of rapid drainage. The FAST algorithm, which we believe to be the most comprehensive SGL tracking algorithm developed to date, has the potential to investigate statistical

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. Tracking algorithms for multiagent systems.

    PubMed

    Meng, Deyuan; Jia, Yingmin; Du, Junping; Yu, Fashan

    2013-10-01

    This paper is devoted to the consensus tracking issue on multiagent systems. Instead of enabling the networked agents to reach an agreement asymptotically as the time tends to infinity, the consensus tracking between agents is considered to be derived on a finite time interval as accurately as possible. We thus propose a learning algorithm with a gain operator to be determined. If the gain operator is designed in the form of a polynomial expression, a necessary and sufficient condition is obtained for the networked agents to accomplish the consensus tracking objective, regardless of the relative degree of the system model of agents. Moreover, the H∞ analysis approach is introduced to help establish conditions in terms of linear matrix inequalities (LMIs) such that the resulting processes of the presented learning algorithm can be guaranteed to monotonically converge in an iterative manner. The established LMI conditions can also enable the iterative learning processes to converge with an exponentially fast speed. In addition, we extend the learning algorithm to address the relative formation problem for multiagent systems. Numerical simulations are performed to demonstrate the effectiveness of learning algorithms in achieving both consensus tracking and relative formation objectives for the networked agents.

  12. 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.

  13. 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.

  14. 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.

  15. Fast tracking using edge histograms

    NASA Astrophysics Data System (ADS)

    Rokita, Przemyslaw

    1997-04-01

    This paper proposes a new algorithm for tracking objects and objects boundaries. This algorithm was developed and applied in a system used for compositing computer generated images and real world video sequences, but can be applied in general in all tracking systems where accuracy and high processing speed are required. The algorithm is based on analysis of histograms obtained by summing along chosen axles pixels of edge segmented images. Edge segmentation is done by spatial convolution using gradient operator. The advantage of such an approach is that it can be performed in real-time using available on the market hardware convolution filters. After edge extraction and histograms computation, respective positions of maximums in edge intensity histograms, in current and previous frame, are compared and matched. Obtained this way information about displacement of histograms maximums, can be directly converted into information about changes of target boundaries positions along chosen axles.

  16. 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.

  17. 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.

  18. Fast track management and control

    SciTech Connect

    Cameron, M.D.O.

    1996-12-31

    This paper, one of a group of papers describing the development of BP`s West of Shetland Foinaven field will set-out the challenges experienced in managing a fast-track project from system design through to offshore installation. ABB Seatec Limited (formerly GEC Marconi Oil and Gas) were commissioned to provide a Multiplexed Electro-Hydraulic Subsea Control System designed for deepwater and for installation/retrieval in a hostile environment. The paper will address the projects critical phase, the project controls implemented, the practical working methods used within a Subsea Alliance and those involved in Client Interaction, Concurrent Engineering, Team Coaching, Internal Procedures and Interface Management in order to meet the exacting schedule for First Oil deliveries. The Project is currently proceeding on routine production deliveries to complete the field development requirements.

  19. Adaptive fast interface tracking methods

    NASA Astrophysics Data System (ADS)

    Popovic, Jelena; Runborg, Olof

    2017-05-01

    In this paper, we present a fast time adaptive numerical method for interface tracking. The method uses an explicit multiresolution description of the interface, which is represented by wavelet vectors that correspond to the details of the interface on different scale levels. The complexity of standard numerical methods for interface tracking, where the interface is described by N marker points, is O (N / Δt), when a time step Δt is used. The methods that we propose in this paper have O (TOL - 1 / p log ⁡ N + Nlog ⁡ N) computational cost, at least for uniformly smooth problems, where TOL is some given tolerance and p is the order of the time stepping method that is used for time advection of the interface. The adaptive method is robust in the sense that it can handle problems with both smooth and piecewise smooth interfaces (e.g. interfaces with corners) while keeping a low computational cost. We show numerical examples that verify these properties.

  20. Fast-track school construction

    SciTech Connect

    Berg, B.M. Jr.

    1997-07-01

    Engineers must provide the best mechanical systems that budget and construction time allow. This school construction project not only successfully balanced these concerns but also addressed indoor air quality issues. The 175,000 sq.ft. Westfield Community School in Community Unit School District 300, Kane County, Ill., was built following a fast-track schedule. Construction began in January 1994 and was completed in August 1996. The building steel and the site utilities were bid and under construction approximately two months before the mechanical, electrical, plumbing, and fire protection work. Westfield Community School houses kindergarten through eighth grade classes. It is an elementary school and middle school that share the same offices, cafeteria, library, multipurpose room, and building services. Three alternatives for the mechanical systems were examined in the initial phase of design for cost and operating characteristics. These were: a central boiler and chiller plant with variable air volume (VAV) distribution and perimeter baseboard radiation; a central boiler and chiller plant with four-pipe distribution supplying hot and chilled water to four-pipe classroom unit ventilators; and a packaged VAV rooftop HVAC unit with gas heating and electric cooling.

  1. 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.

  2. 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.

  3. Fast Algorithms for Exact Exchange

    NASA Astrophysics Data System (ADS)

    Manzer, Samuel Fenton

    This thesis describes several new theoretical developments that facilitate the computation of the exact exchange energy, a vital component of accurate molecular simulations. The primary technique on which these developments are based is the resolution of the identity approximation, particularly the pair atomic resolution of the identity approximation (PARI). We prove that computation of exact exchange using the PARI approximation is variationally stable, and provide benchmarks of the performance and accuracy of our implementation. We then show that the most commonly used SCF convergence acceleration algorithm, DIIS, enables the design of a new fast exchange algorithm that we designate as occ-RI-K. Next, we combine the preceding occ-RI-K algorithm with the PARI approximation to create a linear-scaling exact exchange algorithm for the specific case of large weakly-interacting systems. Finally, we discuss our development of a high-level, object-oriented software library for block-sparse tensor operations. This library provides the underlying implementation for all of the algorithms discussed in this thesis.

  4. 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

  5. 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…

  6. Improved motion information-based infrared dim target tracking algorithms

    NASA Astrophysics Data System (ADS)

    Lei, Liu; Zhijian, Huang

    2014-11-01

    Accurate and fast tracking of infrared (IR) dim target has very important meaning for infrared precise guidance, early warning, video surveillance, etc. However, under complex backgrounds, such as clutter, varying illumination, and occlusion, the traditional tracking method often converges to a local maximum and loses the real infrared target. To cope with these problems, three improved tracking algorithm based on motion information are proposed in this paper, namely improved mean shift algorithm, improved Optical flow method and improved Particle Filter method. The basic principles and the implementing procedure of these modified algorithms for target tracking are described. Using these algorithms, the experiments on some real-life IR and color images are performed. The whole algorithm implementing processes and results are analyzed, and those algorithms for tracking targets are evaluated from the two aspects of subjective and objective. The results prove that the proposed method has satisfying tracking effectiveness and robustness. Meanwhile, it has high tracking efficiency and can be used for real-time tracking.

  7. 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.

  8. 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…

  9. 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…

  10. A fast numerical integrator for relativistic charged particle tracking

    NASA Astrophysics Data System (ADS)

    Qiang, Ji

    2017-09-01

    In this paper, we report on a fast second-order numerical integrator to solve the Lorentz force equations of a relativistic charged particle in electromagnetic fields. This numerical integrator shows less numerical error than the popular Boris algorithm in tracking the relativistic particle subject to electric and magnetic space-charge fields and requires less number of operations than another recently proposed relativistic integrator.

  11. 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

  12. A reliability-based track fusion algorithm.

    PubMed

    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.

  13. Fast decoding algorithms for coded aperture systems

    NASA Astrophysics Data System (ADS)

    Byard, Kevin

    2014-08-01

    Fast decoding algorithms are described for a number of established coded aperture systems. The fast decoding algorithms for all these systems offer significant reductions in the number of calculations required when reconstructing images formed by a coded aperture system and hence require less computation time to produce the images. The algorithms may therefore be of use in applications that require fast image reconstruction, such as near real-time nuclear medicine and location of hazardous radioactive spillage. Experimental tests confirm the efficacy of the fast decoding techniques.

  14. Fast track pathway for perforated appendicitis.

    PubMed

    Frazee, Richard; Abernathy, Stephen; Davis, Matthew; Isbell, Travis; Regner, Justin; Smith, Randall

    2017-04-01

    Perforated appendicitis is associated with an increased morbidity and length of stay. "Fast track" protocols have demonstrated success in shortening hospitalization without increasing morbidity for a variety of surgical processes. This study evaluates a fast track pathway for perforated appendicitis. In 2013, a treatment pathway for perforated appendicitis was adopted by the Acute Care Surgery Service for patients having surgical management of perforated appendicitis. Interval appendectomy was excluded. Patients were treated initially with intravenous antibiotics and transitioned to oral antibiotics and dismissed when medically stable and tolerating oral intake. A retrospective review of patients managed on the fast track pathway was undertaken to analyze length of stay, morbidity, and readmissions. Thirty-four males and twenty-one females with an average age of 46.8 years underwent laparoscopic appendectomy for perforated appendicitis between January 2013 and December 2014. Pre-existing comorbidities included hypertension 42%, diabetes mellitus 11%, COPD 5% and heart disease 2%. No patient had conversion to open appendectomy. Average length of stay was 2.67 days and ranged from 1 to 12 days (median 2 days). Postoperative morbidity was 20% and included abscess (6 patients), prolonged ileus (3 patients), pneumonia (1 patient), and congestive heart failure (1 patient). Five patients were readmitted for abscess (3 patients), congestive heart failure (1 patient), and pneumonia (1 patient). A fast track pathway for perforated appendicitis produced shorter length of stay and acceptable postoperative morbidity and readmission. This offers the potential for significant cost savings over current national practice patterns. Copyright © 2016 Elsevier Inc. All rights reserved.

  15. 40 CFR 72.82 - Fast-track modifications.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 17 2013-07-01 2013-07-01 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, the...

  16. 40 CFR 72.82 - Fast-track modifications.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 17 2012-07-01 2012-07-01 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, the...

  17. 40 CFR 72.82 - Fast-track modifications.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 17 2014-07-01 2014-07-01 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, the...

  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, the...

  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, the...

  20. 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.

  1. Approximate algorithms for fast optimal attitude computation

    NASA Technical Reports Server (NTRS)

    Shuster, M. D.

    1978-01-01

    Fast accurate algorithms are presented for computing an optimal attitude which minimizes a quadratic loss function. These algorithms compute an optimal rotation which carries a set of reference vectors into a set of corresponding observation vectors. Simplifications of these algorithms are obtained for the case of small rotation angles. Applications to the Magsat mission are discussed.

  2. 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.

  3. Target-tracking algorithm for omnidirectional vision

    NASA Astrophysics Data System (ADS)

    Cai, Chengtao; Weng, Xiangyu; Fan, Bing; Zhu, Qidan

    2017-05-01

    Omnidirectional vision with the advantage of a large field-of-view overcomes the problem that a target is easily lost due to the narrow sight of perspective vision. We improve a target-tracking algorithm based on discriminative tracking features in several aspects and propose a target-tracking algorithm for an omnidirectional vision system. (1) An elliptical target window expression model is presented to represent the target's outline, which can adapt to the deformation of an object and reduce background interference. (2) The background-weighted linear RGB histogram target feature is introduced, which decreases the weight of the background feature. (3) The Bhattacharyya coefficients-based feature identification method is employed, which reduces the computation time of the tracking algorithm. (4) An adaptive target scale and orientation measurement method is applied to adapt to severe deformations of the target's outline. (5) A model update strategy is put forward, which is based on similarity measurements to achieve an effective and accurate model update. The experimental results show the proposed algorithm can achieve better performance than the state-of-the-art algorithms when using omnidirectional vision to perform long-term target-tracking tasks.

  4. Fast convolution algorithms for SAR processing

    NASA Astrophysics Data System (ADS)

    dall, Jorgen

    Most high resolution SAR processors apply the Fast Fourier Transform (FFT) to implement convolution by a matched filter impulse response. However, a lower computational complexity is attainable with other algorithms which accordingly have the potential of offering faster and/or simpler processors. Thirteen different fast transform and convolution algorithms are presented, and their characteristics are compared with the fundamental requirements imposed on the algorithms by various SAR processing schemes. The most promising algorithm is based on a Fermat Number Transform (FNT). SAR-580 and SEASAT SAR images have been successfully processed with the FNT, and in this connection the range curvature correction, noise properties and processing speed are discussed.

  5. Detection and Tracking Algorithm Refinement.

    DTIC Science & Technology

    1981-10-01

    position component cast of origin XSCN cross section Y position component north of origin Z reflectivity level viii , f i 1. INTRODUCTION A series of...sequence was assumed to have been performed in an automatic mode. For tracking purposes a volume scan was closely defined to be a series of full...to accomodate data collection in a non-automatic mode, the volume scan has been more loosely defined to be a series of at least two azimuth sector

  6. An algorithm of adaptive scale object tracking in occlusion

    NASA Astrophysics Data System (ADS)

    Zhao, Congmei

    2017-05-01

    Although the correlation filter-based trackers achieve the competitive results both on accuracy and robustness, there are still some problems in handling scale variations, object occlusion, fast motions and so on. In this paper, a multi-scale kernel correlation filter algorithm based on random fern detector was proposed. The tracking task was decomposed into the target scale estimation and the translation estimation. At the same time, the Color Names features and HOG features were fused in response level to further improve the overall tracking performance of the algorithm. In addition, an online random fern classifier was trained to re-obtain the target after the target was lost. By comparing with some algorithms such as KCF, DSST, TLD, MIL, CT and CSK, experimental results show that the proposed approach could estimate the object state accurately and handle the object occlusion effectively.

  7. 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).

  8. Fast diffraction computation algorithms based on FFT

    NASA Astrophysics Data System (ADS)

    Logofatu, Petre Catalin; Nascov, Victor; Apostol, Dan

    2010-11-01

    The discovery of the Fast Fourier transform (FFT) algorithm by Cooley and Tukey meant for diffraction computation what the invention of computers meant for computation in general. The computation time reduction is more significant for large input data, but generally FFT reduces the computation time with several orders of magnitude. This was the beginning of an entire revolution in optical signal processing and resulted in an abundance of fast algorithms for diffraction computation in a variety of situations. The property that allowed the creation of these fast algorithms is that, as it turns out, most diffraction formulae contain at their core one or more Fourier transforms which may be rapidly calculated using the FFT. The key in discovering a new fast algorithm is to reformulate the diffraction formulae so that to identify and isolate the Fourier transforms it contains. In this way, the fast scaled transformation, the fast Fresnel transformation and the fast Rayleigh-Sommerfeld transform were designed. Remarkable improvements were the generalization of the DFT to scaled DFT which allowed freedom to choose the dimensions of the output window for the Fraunhofer-Fourier and Fresnel diffraction, the mathematical concept of linearized convolution which thwarts the circular character of the discrete Fourier transform and allows the use of the FFT, and last but not least the linearized discrete scaled convolution, a new concept of which we claim priority.

  9. Fast Track'' nuclear thermal propulsion concept

    SciTech Connect

    Johnson, R.A.; Zweig, H.R. ); Cooper, M.H.; Wett, J. Jr. )

    1993-01-10

    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).

  10. ``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).

  11. 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.

  12. Fast calibration of electromagnetically tracked oblique-viewing rigid endoscopes.

    PubMed

    Liu, Xinyang; Rice, Christina E; Shekhar, Raj

    2017-06-16

    The oblique-viewing (i.e., angled) rigid endoscope is a commonly used tool in conventional endoscopic surgeries. The relative rotation between its two moveable parts, the telescope and the camera head, creates a rotation offset between the actual and the projection of an object in the camera image. A calibration method tailored to compensate such offset is needed. We developed a fast calibration method for oblique-viewing rigid endoscopes suitable for clinical use. In contrast to prior approaches based on optical tracking, we used electromagnetic (EM) tracking as the external tracking hardware to improve compactness and practicality. Two EM sensors were mounted on the telescope and the camera head, respectively, with considerations to minimize EM tracking errors. Single-image calibration was incorporated into the method, and a sterilizable plate, laser-marked with the calibration pattern, was also developed. Furthermore, we proposed a general algorithm to estimate the rotation center in the camera image. Formulas for updating the camera matrix in terms of clockwise and counterclockwise rotations were also developed. The proposed calibration method was validated using a conventional [Formula: see text], 5-mm laparoscope. Freehand calibrations were performed using the proposed method, and the calibration time averaged 2 min and 8 s. The calibration accuracy was evaluated in a simulated clinical setting with several surgical tools present in the magnetic field of EM tracking. The root-mean-square re-projection error averaged 4.9 pixel (range 2.4-8.5 pixel, with image resolution of [Formula: see text] for rotation angles ranged from [Formula: see text] to [Formula: see text]. We developed a method for fast and accurate calibration of oblique-viewing rigid endoscopes. The method was also designed to be performed in the operating room and will therefore support clinical translation of many emerging endoscopic computer-assisted surgical systems.

  13. 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.

  14. Fast Fourier Transform algorithm design and tradeoffs

    NASA Technical Reports Server (NTRS)

    Kamin, Ray A., III; Adams, George B., III

    1988-01-01

    The Fast Fourier Transform (FFT) is a mainstay of certain numerical techniques for solving fluid dynamics problems. The Connection Machine CM-2 is the target for an investigation into the design of multidimensional Single Instruction Stream/Multiple Data (SIMD) parallel FFT algorithms for high performance. Critical algorithm design issues are discussed, necessary machine performance measurements are identified and made, and the performance of the developed FFT programs are measured. Fast Fourier Transform programs are compared to the currently best Cray-2 FFT program.

  15. 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

  16. 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…

  17. 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…

  18. 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.)

  19. Evaluation of a point-of-care tuberculosis test-and-treat algorithm on early mortality in people with HIV accessing antiretroviral therapy (TB Fast Track study): study protocol for a cluster randomised controlled trial.

    PubMed

    Fielding, Katherine L; Charalambous, Salome; Hoffmann, Christopher J; Johnson, Suzanne; Tlali, Mpho; Dorman, Susan E; Vassall, Anna; Churchyard, Gavin J; Grant, Alison D

    2015-03-28

    Early mortality for HIV-positive people starting antiretroviral therapy (ART) remains high in resource-limited settings, with tuberculosis the most important cause. Existing rapid diagnostic tests for tuberculosis lack sensitivity among HIV-positive people, and consequently, tuberculosis treatment is either delayed or started empirically (without bacteriological confirmation). We developed a management algorithm for ambulatory HIV-positive people, based on body mass index and point-of-care tests for haemoglobin and urine lipoarabinomannan (LAM), to identify those at high risk of tuberculosis and mortality. We designed a clinical trial to test whether implementation of this algorithm reduces six-month mortality among HIV-positive people with advanced immunosuppression. The TB Fast Track study is an open, pragmatic, cluster randomised superiority trial, with 24 primary health clinics randomised to implement the intervention or standard of care. Adults (aged ≥18 years) with a CD4 count of 150 cells/μL or less, who have not received any tuberculosis treatment in the last three months, or ART in the last six months, are eligible. In intervention clinics, the study algorithm is used to classify individuals as at high, medium or low probability of tuberculosis. Those classified as high probability start tuberculosis treatment immediately, followed by ART after two weeks. Medium-probability patients follow the South African guidelines for test-negative tuberculosis and are reviewed within a week, to be re-categorised as low or high probability. Low-probability patients start ART as soon as possible. The primary outcome is all-cause mortality at six months. Secondary outcomes include severe morbidity, time to ART start and cost-effectiveness. This trial will test whether a primary care-friendly management algorithm will enable nurses to identify HIV-positive patients at the highest risk of tuberculosis, to facilitate prompt treatment and reduce early mortality. There

  20. 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.

  1. Review of the algorithms for radar single target tracking

    NASA Astrophysics Data System (ADS)

    Wei, Hao; Cai, Zong-ping; Tang, Bin; Yu, Ze-xiang

    2017-06-01

    The research of radar single target tracking is a hotspot in science all the time. This paper recommends the basic principle of radar single target tracking firstly. Then, the algorithms for radar single target tracking are classified into two segments, namely state estimation and tracking model. And the development of the algorithms is reviewed. It also analyses and comments the methods, features, merit and demerit in the application of these algorithms. At last, this paper introduces new progress of the research field.

  2. Fast track surgery accelerates the recovery of postoperative insulin sensitivity.

    PubMed

    Yang, Dong-jie; Zhang, Sheng; He, Wei-ling; Chen, Hua-yun; Cai, Shi-rong; Chen, Chuang-qi; Song, Xin-ming; Cui, Ji; Ma, Jin-Ping; Zhang, Chang-Hua; He, Yu-Long

    2012-09-01

    Few clinical studies or randomized clinical trial results have reported the impact of fast track surgery on postoperative insulin sensitivity. This study aimed to investigate the effects of fast track surgery on postoperative insulin sensitivity in patients undergoing elective open colorectal resection. Controlled, randomized clinical trial was conducted from November 2008 to January 2009 with one-month post-discharge follow-up. Seventy patients with colorectal carcinoma requiring colorectal resection were randomized into two groups: a fast track group (35 cases) and a conventional care group (35 cases). All included patients received elective open colorectal resection with combined tracheal intubation and general anesthesia. Clinical parameters (complication rates, return of gastrointestinal function and postoperative length of stay), stress index and insulin sensitivity were evaluated in both groups perioperatively. Sixty-two patients finally completed the study, 32 cases in the fast-track group and 30 cases in the conventional care group. Our findings revealed a significantly faster recovery of postoperative insulin sensitivity on postoperative day 7 in the fast-track group than that in the conventional care group. We also found a significantly shorter length of postoperative stay and a significantly faster return of gastrointestinal function in patients undergoing fast-track rehabilitation. Fast track surgery accelerates the recovery of postoperative insulin sensitivity in elective surgery for colorectal carcinoma with a shorter length of postoperative hospital stay.

  3. 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

  4. 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

  5. Sensitivities and applications of a cyclone tracking algorithm

    NASA Astrophysics Data System (ADS)

    Pinto, J. G.; Ulbrich, U.; Leckebusch, G. C.; Donat, M.; Nissen, K. M.; Spangehl, T.; Ulbrich, S.; Zacharias, S.

    2009-09-01

    Various sensitivity studies and applications of an algorithm for the detection and tracking of synoptic scale cyclones from mean sea level pressure (MSLP) data are presented. Both Reanalysis and GCM data are used as input. The scheme considers the cyclone intensity (laplacian of pressure) on the first steps of cyclone intensification. The method, originally developed by Murray and Simmonds (1991) for the SH was adapted to NH cyclone characteristics. With an appropriate setting of the relevant parameters, the algorithm is capable of automatically tracking different types of cyclones at the same time: Comparisons with hand analyses based on manual weather charts shows that both fast moving/intensifying systems as well as smaller scale cyclones can be assessed. The resulting climatology of cyclone variables, e.g., cyclone track density, cyclone counts, intensification rates, propagation speeds, areas of cyclogenesis and decay, gives detailed information on typical cyclone life cycles. Sensitivity studies based on NCEP, ERA40 and GCM data at different resolutions reveal a significant sensitivity of cyclone statistics to the resolution of the input data. Lower spatial and temporal resolutions lead to a reduced number of cyclones. Reducing the temporal resolution alone contributes to a decline in the number of fast moving systems. Lowering spatial resolution alone mainly reduces the number of weak cyclones. Extreme cyclones are selected based on the maximum cyclone intensity (typically the 5% strongest), enabling e.g. a comparison of cyclone characteristics of different intensities. Transient cyclones and explosive developments are selected considering the cyclone displacement and changes of intensity over time. The analysis of the factors contributing to the intensification of cyclones (e.g. baroclinity) as well as the link between the cyclone tracks and the associated wind fields is explored.

  6. 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.

  7. 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.

  8. Fast and reliable active appearance model search for 3-D face tracking.

    PubMed

    Dornaika, F; Ahlberg, J

    2004-08-01

    This paper addresses the three-dimensional (3-D) tracking of pose and animation of the human face in monocular image sequences using active appearance models. The major problem of the classical appearance-based adaptation is the high computational time resulting from the inclusion of a synthesis step in the iterative optimization. Whenever the dimension of the face space is large, a real-time performance cannot be achieved. In this paper, we aim at designing a fast and stable active appearance model search for 3-D face tracking. The main contribution is a search algorithm whose CPU-time is not dependent on the dimension of the face space. Using this algorithm, we show that both the CPU-time and the likelihood of a nonaccurate tracking are reduced. Experiments evaluating the effectiveness of the proposed algorithm are reported, as well as method comparison and tracking synthetic and real image sequences.

  9. A Fast Implementation of the ISOCLUS Algorithm

    NASA Technical Reports Server (NTRS)

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

    2003-01-01

    Unsupervised clustering is a fundamental tool in numerous image processing and remote sensing applications. For example, unsupervised clustering is often used to obtain vegetation maps of an area of interest. This approach is useful when reliable training data are either scarce or expensive, and when relatively little a priori information about the data is available. Unsupervised clustering methods play a significant role in the pursuit of unsupervised classification. One of the most popular and widely used clustering schemes for remote sensing applications is the ISOCLUS algorithm, which is based on the ISODATA method. The algorithm is given a set of n data points (or samples) in d-dimensional space, an integer k indicating the initial number of clusters, and a number of additional parameters. The general goal is to compute a set of cluster centers in d-space. Although there is no specific optimization criterion, the algorithm is similar in spirit to the well known k-means clustering method in which the objective is to minimize the average squared distance of each point to its nearest center, called the average distortion. One significant feature of ISOCLUS over k-means is that clusters may be merged or split, and so the final number of clusters may be different from the number k supplied as part of the input. This algorithm will be described in later in this paper. The ISOCLUS algorithm can run very slowly, particularly on large data sets. Given its wide use in remote sensing, its efficient computation is an important goal. We have developed a fast implementation of the ISOCLUS algorithm. Our improvement is based on a recent acceleration to the k-means algorithm, the filtering algorithm, by Kanungo et al.. They showed that, by storing the data in a kd-tree, it was possible to significantly reduce the running time of k-means. We have adapted this method for the ISOCLUS algorithm. For technical reasons, which are explained later, it is necessary to make a minor

  10. 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.

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

    NASA Astrophysics Data System (ADS)

    Pandini, Carlo; Atlas Collaboration

    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.

  12. 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.

  13. Fast Convolution Algorithms and Associated VHSIC Architectures.

    DTIC Science & Technology

    1983-05-23

    Idenftfy by block number) Finite field, Mersenne prime , Fermat number, primitive element, number- theoretic transform, cyclic convolution, polynomial...elements of order 2 P+p and 2k n in the finite field GF(q 2), where q = 2P-l is a Mersenne prime , p is a prime number, and n is a divisor of 2pl...Abstract - A high-radix f.f.t. algorithm for computing transforms over GF(q2), where q is a Mersenne prime , is developed to implement fast circular

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. Fast algorithms for free-space diffraction patterns calculation

    NASA Astrophysics Data System (ADS)

    Mas, David; Garcia, Javier; Ferreira, Carlos; Bernardo, Luis M.; Marinho, Francisco

    1999-06-01

    Here we present a fast algorithm for Fresnel integral calculation. Some fast algorithms using the fast Fourier transform are analysed and their performance has been checked. These methods are of easy implementation, but are only valid for a specific range of distances. Fast algorithms based on the Fractional Fourier transform allow accurate evaluation of the Fresnel integral from object to Fraunhofer domain in a single step.

  19. Ultra fast-track extubation in heart transplant surgery patients.

    PubMed

    Kianfar, Amir Abbas; Ahmadi, Zargham Hossein; Mirhossein, Seyed Mohsen; Jamaati, Hamidreza; Kashani, Babak Sharif; Mohajerani, Seyed Amir; Firoozi, Ehsan; Salehi, Farshid; Radmand, Golnar; Hashemian, Seyed Mohammadreza

    2015-01-01

    Heart transplant surgeries using cardiopulmonary bypass (CPB) typically requires mechanical ventilation in intensive care units (ICU) in post-operation period. Ultra fast-track extubation (UFE) have been described in patients undergoing various cardiac surgeries. To determine the possibility of ultra-fast-track extubation instead of late extubation in post heart transplant patients. Patients randomly assigned into two groups; Ultra fast-track extubation (UFE) group was defined by extubation inside operating room right after surgery. Late extubation group was defined by patients who were not extubated in operating room and transferred to post operation cardiac care unit (CCU) to extubate. The mean cardiopulmonary bypass time was 136.8 ± 25.7 minutes in ultra-fast extubation and 145.3 ± 29.8 minutes in late extubation patients (P > 0.05). Mechanical ventilation duration (days) was 0 days in ultra-fast and 2.31 ± 1.8 days in late extubation. Length of ICU stay was significantly higher in late extubation group (4.2 ± 1.2 days) than the UFE group (1.72 ± 1.5 days) (P = 0.02). In survival analysis there was no significant difference between ultra-fast and late extubation groups (Log-rank test, P = 0.9). Patients undergoing cardiac transplant could be managed with "ultra-fast-track extubation", without increased morbidity and mortality.

  20. Applications of a cyclone detection and tracking algorithm

    NASA Astrophysics Data System (ADS)

    Pinto, J. G.; Ulbrich, U.; Leckebusch, G. C.; Spangehl, T.; Ulbrich, S.; Zacharias, S.

    2009-04-01

    Various sensitivity studies and applications of an algorithm for the detection and tracking of synoptic scale cyclones from mean sea level pressure data are presented. Both Reanalysis and GCM data are used as input. The scheme considers the cyclone intensity (laplacian of pressure) on the first steps of cyclone intensification. The method, originally developed by Murray and Simmonds (1991) for the SH, was also adapted to NH conditions. With an appropriate setting of the relevant parameters, the algorithm is capable of automatically tracking different types of cyclones at the same time: Comparisons with hand analyses based on manual weather charts shows that both fast moving/intensifying systems as well as smaller scale cyclones (e.g. Mediterranean) can be assessed. A significant sensitivity is found to the spatial and temporal resolution of the input data. The resulting climatology of cyclone variables, e.g., cyclone track density, cyclone counts, intensification rates, propagation speeds, areas of cyclogenesis and cyclolysis, gives detailed information on typical cyclone life cycles. Extreme cyclones are selected based on the maximum cyclone intensity (typically the 5% strongest based on the value of the laplacian of pressure), enabling e.g. a comparison of cyclone characteristics of different intensities. Transient cyclones and explosive developments are selected considering the cyclone displacement and changes of intensity over time. The analysis of the factors contributing to the intensification of cyclones (e.g. jet stream, baroclinity, latent heat) as well as the link between the cyclone tracks and the associated wind and precipitation fields, are explored. Examples of assessment studies on the impact of climate change on the different aspects of cyclone activity (e.g. number, core depth, intensity, typical paths, life-time statistics) based on transient historical and future scenario simulations with coupled AO-GCMs are presented. Special focus is given to

  1. Why Graduate Students Reject the Fast Track

    ERIC Educational Resources Information Center

    Mason, Mary Ann; Goulden, Marc; Frasch, Karie

    2009-01-01

    The authors recently completed an unparalleled survey, with more than eight thousand doctoral student respondents across the University of California system, and what they heard is worrisome: major research universities may be losing some of the most talented tenure-track academics before they even arrive. In the eyes of many doctoral students,…

  2. Energy Dynamics: A Fast Track Inquiry

    ERIC Educational Resources Information Center

    Schmidt, Stan M.; Hrynyshyn, Alec

    2004-01-01

    Students investigate energy conversions by collaborating to develop a free standing track of plastic tubing through which a ball bearing moves at the fastest possible speed. Friendly competition leads to discussion of what worked and did not work and to the identification and investigation of underlying principles. (Contains 4 charts.)

  3. Low manipulation prevalence following fast-track total knee arthroplasty.

    PubMed

    Husted, Henrik; Jørgensen, Christoffer C; Gromov, Kirill; Troelsen, Anders

    2015-02-01

    Postoperative joint stiffness following total knee arthroplasty (TKA) may compromise the outcome and necessitate manipulation. Previous studies have not been in a fast-track setting with optimized pain treatment, early mobilization, and short length of stay (LOS), which may have influenced the prevalence of joint stiffness and subsequent manipulation. We investigated the prevalence of manipulation following fast-track TKA and identified patients at risk of needing manipulation. 3,145 consecutive unselected elective primary unilateral TKA patients operated in 6 departments with well-defined fast-track settings were included in the study. Demographic data, prevalence, type and timing of manipulation, and preoperative and postoperative ROM were recorded prospectively, ensuring complete 1-year follow-up. 70 manipulations were performed within 1 year (2.2%) at a mean of 4 months after index surgery. Younger age and not using walking aids preoperatively were associated with a higher risk of manipulation. LOS ≤ 4 days (as opposed to a longer LOS) was not associated with an increased risk of manipulation. The prevalence of manipulation was lower or comparable to that in most published studies following more conventional pathways. Inherent patient demographics were identified as risk factors for manipulation whereas LOS ≤ 4 days was not. Thus, fast-track TKA does not result in increased risk of manipulation-despite a shorter LOS. Optimized pain treatment and early mobilization may contribute to these favorable results that support the use of fast-track.

  4. Future perspectives and research initiatives in fast-track surgery.

    PubMed

    Kehlet, Henrik

    2006-09-01

    Major surgery is still followed by a risk of morbidity, a need for hospitalisation and convalescence. Fast-track surgery has been introduced as a coordinated effort to combine unimodal evidence-based principles of care into a multi-modal effort to enhance recovery. The aim of this article was to update recent data on fast-track abdominal surgery and outline future strategies for research. The data from fast-track colonic resection support the validity of the concept because pain, ileus, cardiopulmonary function and muscle function were all improved, compared with traditional treatment and with reduced post-operative fatigue and convalescence. Although less data is available, similar positive results may be achieved in other types of major surgery. Current research initiatives include improved multi-modal non-opioid analgesia, rational principles for perioperative fluid management, pharmacological reduction of surgical stress responses and the role of laparoscopic procedures within the fast-track concept. Fast-track surgery has evolved as a valid concept to improve post-operative outcome. Further progress may be expected based upon intensified research within perioperative pathophysiology and a multi-disciplinary collaboration between surgeons, anaesthesiologists and surgical nurses.

  5. 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.

  6. FPGA Online Tracking Algorithm for the PANDA Straw Tube Tracker

    NASA Astrophysics Data System (ADS)

    Liang, Yutie; Ye, Hua; Galuska, Martin J.; Gessler, Thomas; Kuhn, Wolfgang; Lange, Jens Soren; Wagner, Milan N.; Liu, Zhen'an; Zhao, Jingzhou

    2017-06-01

    A novel FPGA based online tracking algorithm for helix track reconstruction in a solenoidal field, developed for the PANDA spectrometer, is described. Employing the Straw Tube Tracker detector with 4636 straw tubes, the algorithm includes a complex track finder, and a track fitter. Implemented in VHDL, the algorithm is tested on a Xilinx Virtex-4 FX60 FPGA chip with different types of events, at different event rates. A processing time of 7 $\\mu$s per event for an average of 6 charged tracks is obtained. The momentum resolution is about 3\\% (4\\%) for $p_t$ ($p_z$) at 1 GeV/c. Comparing to the algorithm running on a CPU chip (single core Intel Xeon E5520 at 2.26 GHz), an improvement of 3 orders of magnitude in processing time is obtained. The algorithm can handle severe overlapping of events which are typical for interaction rates above 10 MHz.

  7. An experimental comparison of online object-tracking algorithms

    NASA Astrophysics Data System (ADS)

    Wang, Qing; Chen, Feng; Xu, Wenli; Yang, Ming-Hsuan

    2011-09-01

    This paper reviews and evaluates several state-of-the-art online object tracking algorithms. Notwithstanding decades of efforts, object tracking remains a challenging problem due to factors such as illumination, pose, scale, deformation, motion blur, noise, and occlusion. To account for appearance change, most recent tracking algorithms focus on robust object representations and effective state prediction. In this paper, we analyze the components of each tracking method and identify their key roles in dealing with specific challenges, thereby shedding light on how to choose and design algorithms for different situations. We compare state-of-the-art online tracking methods including the IVT,1 VRT,2 FragT,3 BoostT,4 SemiT,5 BeSemiT,6 L1T,7 MILT,8 VTD9 and TLD10 algorithms on numerous challenging sequences, and evaluate them with different performance metrics. The qualitative and quantitative comparative results demonstrate the strength and weakness of these algorithms.

  8. 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.

  9. A Fast Implementation of the ISOCLUS Algorithm

    NASA Technical Reports Server (NTRS)

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

    2003-01-01

    (kn) time, where k denotes the current number of centers. Traditional techniques for accelerating nearest neighbor searching involve storing the k centers in a data structure. However, because of the iterative nature of the algorithm, this data structure would need to be rebuilt with each new iteration. Our approach is to store the data points in a kd-tree data structure. The assignment of points to nearest neighbors is carried out by a filtering process, which successively eliminates centers that can not possibly be the nearest neighbor for a given region of space. This algorithm is significantly faster, because large groups of data points can be assigned to their nearest center in a single operation. Preliminary results on a number of real Landsat datasets show that our revised ISOCLUS-like scheme runs about twice as fast.

  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. Merging Universal and Indicated Prevention Programs: The Fast Track Model

    PubMed Central

    2009-01-01

    Fast Track is a multisite, multicomponent preventive intervention for young children at high risk for long-term antisocial behavior. Based on a comprehensive developmental model, this intervention includes a universal-level classroom program plus social-skill training, academic tutoring, parent training, and home visiting to improve competencies and reduce problems in a high-risk group of children selected in kindergarten. The theoretical principles and clinical strategies utilized in the Fast Track Project are described to illustrate the interplay between basic developmental research, the understanding of risk and protective factors, and a research-based model of preventive intervention that integrates universal and indicated models of prevention. PMID:11125779

  12. [Principles of fast track surgery. Multimodal perioperative therapy programme].

    PubMed

    Kehlet, H

    2009-08-01

    Recent evidence has documented that a combination of single-modality evidence-based care principles into a multimodal effort to enhance postoperative recovery (the fast track methodology) has led to enhanced recovery with reduced medical morbidity, need for hospitalisation and convalescence. Nevertheless, general implementation of fast track surgery has been relatively slow despite concomitant economic benefits. Further improvement in postoperative outcome may be obtained by developments within each care principle with a specific focus on minimally invasive surgery, effective multimodal, non-opioid analgesia and pharmacological stress reduction.

  13. 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

  14. 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.

  15. 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.

  16. 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.

  17. 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…

  18. 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.

  19. 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…

  20. 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…

  1. 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…

  2. 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.

  3. Fast-track surgery: Toward comprehensive peri-operative care

    PubMed Central

    Nanavati, Aditya J.; Prabhakar, S.

    2014-01-01

    Fast-track surgery is a multimodal approach to patient care using a combination of several evidence-based peri-operative interventions to expedite recovery after surgery. It is an extension of the critical pathway that integrates modalities in surgery, anesthesia, and nutrition, enforces early mobilization and feeding, and emphasizes reduction of the surgical stress response. It entails a great partnership between a surgeon and an anesthesiologist with several other specialists to form a multi-disciplinary team, which may then engage in patient care. The practice of fast-track surgery has yielded excellent results and there has been a significant reduction in hospital stay without a rise in complications or re-admissions. The effective implementation begins with the formulation of a protocol, carrying out each intervention and gathering outcome data. The care of a patient is divided into three phases: Before, during, and after surgery. Each stage needs active participation of few or all the members of the multi-disciplinary team. Other than surgical technique, anesthetic drugs, and techniques form the cornerstone in the ability of the surgeon to carry out a fast-track surgery safely. It is also the role of this team to keep abreast with the latest development in fast-track methodology and make appropriate changes to policy. In the Indian healthcare system, there is a huge benefit that may be achieved by the successful implementation of a fast-track surgery program at an institutional level. The lack of awareness regarding this concept, fear and apprehension regarding its implementation are the main barriers that need to be overcome. PMID:25886214

  4. 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

  5. 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.

  6. A novel fast target tracking method for UAV aerial image

    NASA Astrophysics Data System (ADS)

    Jianfang, Liu; Hao, Zheng; Jingli, Gao

    2017-06-01

    Unmanned aerial vehicles (UAV) are able to achieve autonomous flight without drivers, and UAV has been a key tool to extract space data. Therefore, how to detect the trajectories of targets from UAV aerial image sequences is of great importance. Because local features are suitable to detect target tracking, we exploit scaleinvariant feature transform (SIFT) features to describe the interesting keypoints of targets. The main innovation of this paper is to utilize Multiple hypothesis tracking (MHT) algorithm to track an object (target) in a series of image sequences. Particularly, we develop a MHT framework based on a multidimensional assignment formulation and a sliding time window policy. To obtain target tracking from UAV aerial image sequences, three steps should be done, that is, 1) Breaking each track set into tracklet at a specific time, 2) Estimating the association cost of each track set, 3) Merging trajectory fragments to a longer one iteratively. Finally, we collect several UAV aerial image sequences with different target density to construct a dataset, and experimental results demonstrate the effectiveness of the proposed algorithm.

  7. 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.

  8. 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.

  9. Edge-following algorithm for tracking geological features

    NASA Technical Reports Server (NTRS)

    Tietz, J. C.

    1977-01-01

    Sequential edge-tracking algorithm employs circular scanning to point permit effective real-time tracking of coastlines and rivers from earth resources satellites. Technique eliminates expensive high-resolution cameras. System might also be adaptable for application in monitoring automated assembly lines, inspecting conveyor belts, or analyzing thermographs, or x ray images.

  10. 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.

  11. 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

  12. 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.

  13. Nursing role on rapid recovery programmes fast-track.

    PubMed

    Sevillano-Jiménez, Alfonso; Romero-Saldaña, Manuel; Molina-Recio, Guillermo

    2017-07-27

    Rapid recovery (RR) or fast-track programmes are aimed at reducing surgical stress, leading to a reduction in nurse workload, costs and hospital stay, greater patient empowerment, early post-surgical recovery and reduced morbidity and mortality. These new protocols require the coordinated participation of a multidisciplinary team. Based on an integrative review of the literature, this paper aims to define the concept of a RR or fast track programme and show the existing evidence on the implementation of these programmes in nursing. The benefits and low incidence of damage of RR programmes in nursing justify their implementation. The programmes require greater support and diffusion in order to develop, as well as more research to increase the evidence on the effectiveness and efficiency of the protocols. Copyright © 2017 Elsevier España, S.L.U. All rights reserved.

  14. 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.

  15. 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.

  16. 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.

  17. Improved infrared target-tracking algorithm based on mean shift.

    PubMed

    Wang, Zhile; Hou, Qingyu; Hao, Ling

    2012-07-20

    An improved IR target-tracking algorithm based on mean shift is proposed herein, which combines the mean-shift-based gradient-matched searching strategy with a feature-classification-based tracking algorithm. An improved target representation model is constructed by considering the likelihood ratio of the gray-level features of the target and local background as a weighted value of the original kernel histogram of the target region. An expression for the mean-shift vector in this model is derived, and a criterion for updating the model is presented. Experimental results show that the algorithm improves the shift weight of the target pixel gray level and suppresses background disturbance.

  18. Model of ballistic targets' dynamics used for trajectory tracking algorithms

    NASA Astrophysics Data System (ADS)

    Okoń-FÄ fara, Marta; Kawalec, Adam; Witczak, Andrzej

    2017-04-01

    There are known only few ballistic object tracking algorithms. To develop such algorithms and to its further testing, it is necessary to implement possibly simple and reliable objects' dynamics model. The article presents the dynamics' model of a tactical ballistic missile (TBM) including the three stages of flight: the boost stage and two passive stages - the ascending one and the descending one. Additionally, the procedure of transformation from the local coordinate system to the polar-radar oriented and the global is presented. The prepared theoretical data may be used to determine the tracking algorithm parameters and to its further verification.

  19. Fast-track cardiac care for adult cardiac surgical patients.

    PubMed

    Wong, Wai-Tat; Lai, Veronica Kw; Chee, Yee Eot; Lee, Anna

    2016-09-12

    Fast-track cardiac care is a complex intervention involving several components of care during cardiac anaesthesia and in the postoperative period, with the ultimate aim of early extubation after surgery, to reduce length of stay in the intensive care unit and in the hospital. Safe and effective fast-track cardiac care may reduce hospital costs. This is an update of a Cochrane review first published in 2003, updated in 2012 and updated now in 2016. To determine the safety and effectiveness of fast-track cardiac care compared with conventional (not fast-track) care in adult patients undergoing cardiac surgery. Fast-track cardiac care intervention includes administration of low-dose opioid-based general anaesthesia or use of a time-directed extubation protocol, or both. We searched the Cochrane Central Register of Controlled Trials (CENTRAL; 2015, Issue 5), MEDLINE (January 2012 to May 2015), Embase (January 2012 to May 2015), the Cumulative Index to Nursing and Allied Health Literature (CINAHL; January 2012 to May 2015) and the Institute for Scientific Information (ISI) Web of Science (January 2012 to May 2015), along with reference lists of articles, to identify additional trials. We applied no language restrictions. We included all randomized controlled trials of adult cardiac surgical patients (coronary artery bypass grafts, aortic valve replacement, mitral valve replacement) that compared fast-track cardiac care and conventional (not fast-track) care groups. We focused on the following fast-track interventions, which were designed for early extubation after surgery: administration of low-dose opioid-based general anaesthesia during cardiac surgery and use of a time-directed extubation protocol after surgery. The primary outcome was risk of mortality. Secondary outcomes included postoperative complications, reintubation within 24 hours of surgery, time to extubation, length of stay in the intensive care unit and in the hospital, quality of life after surgery and

  20. 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.

  1. A fast quaternion-based orientation optimizer via virtual rotation for human motion tracking.

    PubMed

    Lee, Jung Keun; Park, Edward J

    2009-05-01

    For real-time ambulatory human motion tracking with low-cost inertial/magnetic sensors, a computationally efficient and robust algorithm for estimating orientation is critical. This paper presents a quaternion-based orientation optimizer for tracking human body motion, using triaxis rate gyro, accelerometer, and magnetometer signals. The proposed optimizer uses a Gauss-Newton (G-N) method for finding the best-fit quaternion. In order to decrease the computing time, the optimizer is formulated using a virtual rotation concept that allows very fast quaternion updates compared to the conventional G-N method. In addition, to guard against the effects of fast body motions and temporary ferromagnetic disturbances, a situational measurement vector selection procedure is adopted in conjunction with the G-N optimizer. The accuracy of orientation estimates is validated experimentally, using arm motion trials.

  2. Fast non-iterative calibration of an external motion tracking device

    PubMed Central

    Zahneisen, Benjamin; Lovell-Smith, Chris; Herbst, Michael; Zaitsev, Maxim; Speck, Oliver; Armstrong, Brian; Ernst, Thomas

    2013-01-01

    Purpose Prospective motion correction of MR scans commonly uses an external device, such as a camera, to track the pose of the organ of interest. However, in order for external tracking data to be translated into the MR scanner reference frame, the pose of the camera relative to the MR scanner must be known accurately. Here, we describe a fast, accurate, non-iterative technique to determine the position of an external tracking device de novo relative to the MR reference frame. Theory and Methods The method relies on imaging a sparse object that allows simultaneous tracking of arbitrary rigid body transformations in the reference frame of the MRI machine and that of the external tracking device. Results Large motions in the MRI reference frame can be measured using a sparse phantom with an accuracy of 0.2 mm, or approximately 1/10 of the voxel size. By using a dual quaternion algorithm to solve the calibration problem, a good camera calibration can be achieved with fewer than 6 measurements. Further refinements can be achieved by applying the method iteratively and using motion correction feedback. Conclusion Independent tracking of a series of movements in two reference frames allows for an analytical solution to the hand-eye-calibration problem for various motion tracking setups in MRI. PMID:23788117

  3. A fast high-resolution track trigger for the H1 experiment

    NASA Astrophysics Data System (ADS)

    Naumann, J.; Baird, A.; Elsen, E.; Fleming, Y. H.; Kolander, M.; Kolya, S.; Meer, D.; Mercer, D.; Newman, P. R.; Sankey, D.; Schoning, A.; Schultz-Coulon, H.-C.; Wissing, C.

    2001-08-01

    After 2001, the upgraded ep collider HERA will provide an about five times higher luminosity for the two experiments H1 and ZEUS. To cope with the expected higher event rates, the H1 collaboration is building a track-based trigger system, the Fast Track Trigger (FTT). It will be integrated in the first three levels (L1-L3) of the H1 trigger scheme to provide higher selectivity for events with charged particles. The FTT will allow reconstruction of three-dimensional tracks in the central drift chamber down to 100 MeV/c within the L2 latency of /spl sim/23 /spl mu/s. To reach the necessary momentum resolution of /spl sim/5% (at 1 GeV/c), sophisticated reconstruction algorithms have to be implemented using high-density field-programmable gate arrays and their embedded content addressable memories. The final track parameter optimization will be done using noniterative fits implemented in digital signal processors. While at the first trigger level rough track information will be provided, at L2 tracks with high resolution are available to form trigger decisions on topological and other track-based criteria like multiplicities and momenta. At the third trigger level, a farm of commercial processor boards will be used to compute physics quantities such as invariant masses.

  4. 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.

  5. From the Fast Track to the Fast Lane--To What?

    ERIC Educational Resources Information Center

    Weininger, Otto

    1990-01-01

    Young children are being fast tracked at early age because of pressures from parents, schools, society, and media. One result is troubled teenagers who experience stress of these pressures without having adult means to cope with them. Time spent with parents and in play activities are activities that help children to gain security, happiness, and…

  6. Fast-track cardiac care for adult cardiac surgical patients.

    PubMed

    Zhu, Fang; Lee, Anna; Chee, Yee Eot

    2012-10-17

    Fast-track cardiac care is a complex intervention involving several components of care during cardiac anaesthesia and in the postoperative period, all with the ultimate aim of early extubation after surgery, to reduce the length of stay in the intensive care unit and in the hospital. Safe and effective fast-track cardiac care may reduce hospital costs. This is an update of a Cochrane review published in 2003. To update the evidence on the safety and effectiveness of fast-track cardiac care compared to conventional (not fast-track) care in adult patients undergoing cardiac surgery. We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (2012, Issue 3), MEDLINE (January 1966 to April 2012), EMBASE (January 1980 to April 2012), CINAHL (January 1982 to April 2012), and ISI Web of Science (January 2003 to April 2012). We searched reference lists of articles and contacted experts in the field. All randomized controlled trials of adult cardiac surgical patients (coronary artery bypass grafts, aortic valve replacement, mitral valve replacement) that compared fast-track cardiac care and conventional (not fast-track) care groups were included. We focused on the following fast-track interventions that were designed for early extubation after surgery, administration of low-dose opioid based general anaesthesia during cardiac surgery and the use of a time-directed extubation protocol after surgery. The primary outcome was the risk of mortality. Secondary outcomes included postoperative complications, reintubation within 24 hours of surgery, time to extubation, length of stay in the intensive care unit and in the hospital, quality of life after surgery and hospital costs. Two review authors independently assessed trial quality and extracted the data. Study authors were contacted for additional information. We used a random-effects model and reported relative risk (RR), mean difference (MD) and 95% confidence intervals (95% CI). Twenty-five trials involving 4118

  7. 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

  8. 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.

  9. The track finding algorithm of the Belle II vertex detectors

    NASA Astrophysics Data System (ADS)

    Bilka, Tadeas; Braun, Nils; Casarosa, Giulia; Frost, Oliver; Frühwirth, Rudolf; Hauth, Thomas; Heck, Martin; Kandra, Jakub; Kodys, Peter; Kvasnicka, Peter; Lettenbichler, Jakob; Lück, Thomas; Madlener, Thomas; Metzner, Felix; Nadler, Moritz; Oberhof, Benjamin; Paoloni, Eugenio; Prim, Markus; Ritter, Martin; Schlüter, Tobias; Schnell, Michael; Spruck, Bjoern; Trusov, Viktor; Wagner, Jonas; Wessel, Christian; Ziegler, Michael

    2017-08-01

    The Belle II experiment is a high energy multi purpose particle detector operated at the asymmetric e+e- - collider SuperKEKB in Tsukuba (Japan). In this work we describe the algorithm performing the pattern recognition for inner tracking detector which consists of two layers of pixel detectors and four layers of double sided silicon strip detectors arranged around the interaction region. The track finding algorithm will be used both during the High Level Trigger on-line track reconstruction and during the off-line full reconstruction. It must provide good efficiency down to momenta as low as 50 MeV/c where material effects are sizeable even in an extremely thin detector as the VXD. In addition it has to be able to cope with the high occupancy of the Belle II detectors due to the background. The underlying concept of the track finding algorithm, as well as details of the implementation are outlined. The algorithm is proven to run with good performance on simulated ϒ(4S) → BB¯ events with an efficiency for reconstructing tracks of above 90% over a wide range of momentum.

  10. 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.

  11. 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.

  12. 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.

  13. Comparison of image processing algorithms for tracking illuminated targets

    NASA Astrophysics Data System (ADS)

    Bukley, Jerry W.; Cramblitt, Robert M.

    1999-07-01

    Pointing the line-of-sight of an acquisition, tracking and pointing (ATP) system at a target requires designation of a reference line of sight (LOS) based principally on the target image. For many system, this will also include registration of a specific fiducial on the target for precision pointing. It is difficult to select a track reference because of algorithm sensitivity to modeling of the image. The selection of a track reference ins further complicated by image variations associated with changes in the viewing geometry and target characteristics. This paper compares several image-processing algorithms for the precision pointing of a near-space ATP platform that is viewing missile targets. The platform has state-of-the-art alignment, stabilization and tracking functions. The algorithms are tested in a full imaging and control system simulation that models an illuminating laser beam, target reflectance, optical effects, the sensor, a high order control system and pointing dynamics. The target models are based on flight dynamics, orientation, measured drawings and surface reflectivity. The simulation results are compared by calculating bias, drift and jitter characteristics of the error incurred when attempting to point the optical line-of- sight at the target. Several algorithms have been identified that provide a pointing reference capable of sustaining sub- microradian error. This paper describes the calculation of the fiducials for the algorithms and compares their relative merits.

  14. Improving the apatite fission-track annealing algorithm

    NASA Astrophysics Data System (ADS)

    Luijendijk, Elco; Andriessen, Paul; ter Voorde, Marlies; van Balen, Ronald

    2017-04-01

    Low-temperature thermochronology is a key tool to quantifying the thermal history and exhumation of the crust. The interpretation of one of the most widely-used thermochronometers, apatite fission-track analysis, relies on models that relate fission track density to temperature history. These models have been calibrated to fission-track data from the Otway basin, Australia. We discuss geological evidence that the current benchmark dataset is located in a basin in which rocks may have been warmer in the past than previously assumed. We recalibrate the apatite fission-track annealing algorithm to a dataset from Southern Texas with a well-constrained thermal history. We show that current models underestimate the temperature at which fission tracks anneal completely by 19 ˚C to 34 ˚C. Exhumation rates derived from fission-track data have been underestimated; at normal geothermal gradients estimates may have to be revised upward by 500 to 2000 m. The results also have implications for the (U-Th)/He thermochronometer, because radiation damage influences the diffusivity of helium in apatites. The difference in modelled (U-Th)/He ages is approximately 10% for samples that have undergone a long cooling history. We also present a new Python code that can be used for forward or inverse modelling of fission track data using the new annealing algorithm.

  15. 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.

  16. 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.

  17. 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 .

  18. 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.

  19. 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)

  20. 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.

  1. Fast Algorithms for Model-Based Diagnosis

    NASA Technical Reports Server (NTRS)

    Fijany, Amir; Barrett, Anthony; Vatan, Farrokh; Mackey, Ryan

    2005-01-01

    Two improved new methods for automated diagnosis of complex engineering systems involve the use of novel algorithms that are more efficient than prior algorithms used for the same purpose. Both the recently developed algorithms and the prior algorithms in question are instances of model-based diagnosis, which is based on exploring the logical inconsistency between an observation and a description of a system to be diagnosed. As engineering systems grow more complex and increasingly autonomous in their functions, the need for automated diagnosis increases concomitantly. In model-based diagnosis, the function of each component and the interconnections among all the components of the system to be diagnosed (for example, see figure) are represented as a logical system, called the system description (SD). Hence, the expected behavior of the system is the set of logical consequences of the SD. Faulty components lead to inconsistency between the observed behaviors of the system and the SD. The task of finding the faulty components (diagnosis) reduces to finding the components, the abnormalities of which could explain all the inconsistencies. Of course, the meaningful solution should be a minimal set of faulty components (called a minimal diagnosis), because the trivial solution, in which all components are assumed to be faulty, always explains all inconsistencies. Although the prior algorithms in question implement powerful methods of diagnosis, they are not practical because they essentially require exhaustive searches among all possible combinations of faulty components and therefore entail the amounts of computation that grow exponentially with the number of components of the system.

  2. 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

  3. 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.

  4. 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.

  5. 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

  6. Encoding color information for visual tracking: Algorithms and benchmark.

    PubMed

    Liang, Pengpeng; Blasch, Erik; Ling, Haibin

    2015-12-01

    While color information is known to provide rich discriminative clues for visual inference, most modern visual trackers limit themselves to the grayscale realm. Despite recent efforts to integrate color in tracking, there is a lack of comprehensive understanding of the role color information can play. In this paper, we attack this problem by conducting a systematic study from both the algorithm and benchmark perspectives. On the algorithm side, we comprehensively encode 10 chromatic models into 16 carefully selected state-of-the-art visual trackers. On the benchmark side, we compile a large set of 128 color sequences with ground truth and challenge factor annotations (e.g., occlusion). A thorough evaluation is conducted by running all the color-encoded trackers, together with two recently proposed color trackers. A further validation is conducted on an RGBD tracking benchmark. The results clearly show the benefit of encoding color information for tracking. We also perform detailed analysis on several issues, including the behavior of various combinations between color model and visual tracker, the degree of difficulty of each sequence for tracking, and how different challenge factors affect the tracking performance. We expect the study to provide the guidance, motivation, and benchmark for future work on encoding color in visual tracking.

  7. 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.

  8. Fast molecular tracking maps nanoscale dynamics of plasma membrane lipids

    PubMed Central

    Sahl, Steffen J.; Leutenegger, Marcel; Hilbert, Michael; Hell, Stefan W.; Eggeling, Christian

    2010-01-01

    We describe an optical method capable of tracking a single fluorescent molecule with a flexible choice of high spatial accuracy (∼10–20 nm standard deviation or ∼20–40 nm full-width-at-half-maximum) and temporal resolution (< 1 ms). The fluorescence signal during individual passages of fluorescent molecules through a spot of excitation light allows the sequential localization and thus spatio-temporal tracking of the molecule if its fluorescence is collected on at least three separate point detectors arranged in close proximity. We show two-dimensional trajectories of individual, small organic dye labeled lipids diffusing in the plasma membrane of living cells and directly observe transient events of trapping on < 20 nm spatial scales. The trapping is cholesterol-assisted and much more pronounced for a sphingo- than for a phosphoglycero-lipid, with average trapping times of ∼15 ms and < 4 ms, respectively. The results support previous STED nanoscopy measurements and suggest that, at least for nontreated cells, the transient interaction of a single lipid is confined to macromolecular dimensions. Our experimental approach demonstrates that fast molecular movements can be tracked with minimal invasion, which can reveal new important details of cellular nano-organization. PMID:20351247

  9. Fast search algorithms for computational protein design.

    PubMed

    Traoré, Seydou; Roberts, Kyle E; Allouche, David; Donald, Bruce R; André, Isabelle; Schiex, Thomas; Barbe, Sophie

    2016-05-05

    One of the main challenges in computational protein design (CPD) is the huge size of the protein sequence and conformational space that has to be computationally explored. Recently, we showed that state-of-the-art combinatorial optimization technologies based on Cost Function Network (CFN) processing allow speeding up provable rigid backbone protein design methods by several orders of magnitudes. Building up on this, we improved and injected CFN technology into the well-established CPD package Osprey to allow all Osprey CPD algorithms to benefit from associated speedups. Because Osprey fundamentally relies on the ability of A* to produce conformations in increasing order of energy, we defined new A* strategies combining CFN lower bounds, with new side-chain positioning-based branching scheme. Beyond the speedups obtained in the new A*-CFN combination, this novel branching scheme enables a much faster enumeration of suboptimal sequences, far beyond what is reachable without it. Together with the immediate and important speedups provided by CFN technology, these developments directly benefit to all the algorithms that previously relied on the DEE/ A* combination inside Osprey* and make it possible to solve larger CPD problems with provable algorithms. © 2016 Wiley Periodicals, Inc.

  10. 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.

  11. 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.

  12. CS-based fast ultrasound imaging with improved FISTA algorithm

    NASA Astrophysics Data System (ADS)

    Lin, Jie; He, Yugao; Shi, Guangming; Han, Tingyu

    2015-08-01

    In ultrasound imaging system, the wave emission and data acquisition is time consuming, which can be solved by adopting the plane wave as the transmitted signal, and the compressed sensing (CS) theory for data acquisition and image reconstruction. To overcome the very high computation complexity caused by introducing CS into ultrasound imaging, in this paper, we propose an improvement of the fast iterative shrinkage-thresholding algorithm (FISTA) to achieve the fast reconstruction of the ultrasound imaging, in which a modified setting is done with the parameter of step size for each iteration. Further, the GPU strategy is designed for the proposed algorithm, to guarantee the real time implementation of imaging. The simulation results show that the GPU-based image reconstruction algorithm can achieve the fast ultrasound imaging without damaging the quality of image.

  13. A GPU implementation of a track-repeating algorithm for proton radiotherapy dose calculations.

    PubMed

    Yepes, Pablo P; Mirkovic, Dragan; Taddei, Phillip J

    2010-12-07

    An essential component in proton radiotherapy is the algorithm to calculate the radiation dose to be delivered to the patient. The most common dose algorithms are fast but they are approximate analytical approaches. However their level of accuracy is not always satisfactory, especially for heterogeneous anatomical areas, like the thorax. Monte Carlo techniques provide superior accuracy; however, they often require large computation resources, which render them impractical for routine clinical use. Track-repeating algorithms, for example the fast dose calculator, have shown promise for achieving the accuracy of Monte Carlo simulations for proton radiotherapy dose calculations in a fraction of the computation time. We report on the implementation of the fast dose calculator for proton radiotherapy on a card equipped with graphics processor units (GPUs) rather than on a central processing unit architecture. This implementation reproduces the full Monte Carlo and CPU-based track-repeating dose calculations within 2%, while achieving a statistical uncertainty of 2% in less than 1 min utilizing one single GPU card, which should allow real-time accurate dose calculations.

  14. A modified algorithm for identifying and tracking extratropical cyclones

    NASA Astrophysics Data System (ADS)

    Lu, Chuhan

    2017-07-01

    In this study, a modified identification and tracking algorithm for extratropical cyclones is developed. This identification scheme is based on triangular-mesh contouring techniques combined with a connected-component labeling method in order to detect the outer boundaries and spatial domain characteristics of individual cyclones. A new tracking method allowing for the identification of cyclone merging and splitting events, as well as short-lived windstorms, is developed to reduce the uncertainty in the tracking of extratropical cyclones. I also show that this method excludes the tracks of open systems that would have been unnecessarily detected using conventional NCP methods. The climatological features of the distribution of cyclone frequencies are substantially larger over the traditional storm track regions compared to those seen in previous studies. Interestingly, a significant increase in the cyclone density in the Arctic occurs during all four seasons (up to 19% in summer) compared to that seen with a latitude-longitude gridded mesh analysis. I develop two new regional intensity indices (depth and vorticity) based on the cyclonic domain to better quantify the cyclonic activity in the Arctic region, and find that the interannual variabilities in these two indices are highly consistent. The results of this analysis may shed light on high-latitude cyclonic behavior studies via the newly detected 2D cyclone atlas derived from this cyclonic-domain-based algorithm.

  15. 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.

  16. 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.

  17. Robust perception algorithms for road and track autonomous following

    NASA Astrophysics Data System (ADS)

    Marion, Vincent; Lecointe, Olivier; Lewandowski, Cecile; Morillon, Joel G.; Aufrere, Romuald; Marcotegui, Beatrix; Chapuis, Roland; Beucher, Serge

    2004-09-01

    The French Military Robotic Study Program (introduced in Aerosense 2003), sponsored by the French Defense Procurement Agency and managed by Thales Airborne Systems as the prime contractor, focuses on about 15 robotic themes, which can provide an immediate "operational add-on value." The paper details the "road and track following" theme (named AUT2), which main purpose was to develop a vision based sub-system to automatically detect roadsides of an extended range of roads and tracks suitable to military missions. To achieve the goal, efforts focused on three main areas: (1) Improvement of images quality at algorithms inputs, thanks to the selection of adapted video cameras, and the development of a THALES patented algorithm: it removes in real time most of the disturbing shadows in images taken in natural environments, enhances contrast and lowers reflection effect due to films of water. (2) Selection and improvement of two complementary algorithms (one is segment oriented, the other region based) (3) Development of a fusion process between both algorithms, which feeds in real time a road model with the best available data. Each previous step has been developed so that the global perception process is reliable and safe: as an example, the process continuously evaluates itself and outputs confidence criteria qualifying roadside detection. The paper presents the processes in details, and the results got from passed military acceptance tests, which trigger the next step: autonomous track following (named AUT3).

  18. 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.

  19. 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).

  20. 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

  1. 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.

  2. A fast algorithm for identifying friends-of-friends halos

    NASA Astrophysics Data System (ADS)

    Feng, Y.; Modi, C.

    2017-07-01

    We describe a simple and fast algorithm for identifying friends-of-friends features and prove its correctness. The algorithm avoids unnecessary expensive neighbor queries, uses minimal memory overhead, and rejects slowdown in high over-density regions. We define our algorithm formally based on pair enumeration, a problem that has been heavily studied in fast 2-point correlation codes and our reference implementation employs a dual KD-tree correlation function code. We construct features in a hierarchical tree structure, and use a splay operation to reduce the average cost of identifying the root of a feature from O [ log L ] to O [ 1 ] (L is the size of a feature) without additional memory costs. This reduces the overall time complexity of merging trees from O [ L log L ] to O [ L ] , reducing the number of operations per splay by orders of magnitude. We next introduce a pruning operation that skips merge operations between two fully self-connected KD-tree nodes. This improves the robustness of the algorithm, reducing the number of merge operations in high density peaks from O [δ2 ] to O [ δ ] . We show that for cosmological data set the algorithm eliminates more than half of merge operations for typically used linking lengths b ∼ 0 . 2 (relative to mean separation). Furthermore, our algorithm is extremely simple and easy to implement on top of an existing pair enumeration code, reusing the optimization effort that has been invested in fast correlation function codes.

  3. Face pose tracking using the four-point algorithm

    NASA Astrophysics Data System (ADS)

    Fung, Ho Yin; Wong, Kin Hong; Yu, Ying Kin; Tsui, Kwan Pang; Kam, Ho Chuen

    2017-06-01

    In this paper, we have developed an algorithm to track the pose of a human face robustly and efficiently. Face pose estimation is very useful in many applications such as building virtual reality systems and creating an alternative input method for the disabled. Firstly, we have modified a face detection toolbox called DLib for the detection of a face in front of a camera. The detected face features are passed to a pose estimation method, known as the four-point algorithm, for pose computation. The theory applied and the technical problems encountered during system development are discussed in the paper. It is demonstrated that the system is able to track the pose of a face in real time using a consumer grade laptop computer.

  4. 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.

  5. 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.

  6. "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.

  7. Separated Representations and Fast Algorithms for Materials Science

    DTIC Science & Technology

    2007-10-29

    SUBJECT TERMS Separated representations, Green’s function, fast algorithms, Schrodinger equation Gregory Beylkin, Lucas Monzon and Fernando Perez...started the process of comparing our approach to solving multiparticle Schrodinger equation to that currently used in Quantum Chemistry. (a) Papers...J. Mohlenkamp, and Fernando Perez, "Toward Solving the Multiparticle Schrodinger Equation via an Unconstrained Sum of Slater Determinants", Pacific

  8. 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.

  9. 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.

  10. Automatic seismic event tracking using a dynamic time warping algorithm

    NASA Astrophysics Data System (ADS)

    Jin, Song; Chen, ShuangQuan; Wei, Jianxin; Li, Xiang-Yang

    2017-10-01

    For seismic data interpretation, horizon picking based on seismic events in stacked or migrated seismic sections is essential for obtaining information on subsurface structures. This conventional work is time-consuming via manual implementation. In this paper, we develop an automatic seismic event tracking method of horizon interpretation using the dynamic time warping (DTW) algorithm. The proposed method consists of two steps: calculating local time shifts between adjacent traces through a pilot trace and then event tracking. In the method, the DTW algorithm is applied to calculate time shifts between two adjacent traces, and an improved multitrace DTW strategy is proposed to improve the robustness. One synthetic seismic trace is used to demonstrate the DTW algorithm, and a synthetic seismic section is used to verify the feasibility of the proposed method handling contaminated seismic data with noise. Finally, we apply the method to a 3D physical model dataset. The result indicates that the proposed method is quantitatively feasible for seismic event automatic tracking and is reasonably stable for noisy seismic section flattening, which also has the potential to extract seismic horizon slices effectively.

  11. 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.

  12. 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.

  13. A fast exact sequential algorithm for the partial digest problem.

    PubMed

    Abbas, Mostafa M; Bahig, Hazem M

    2016-12-22

    Restriction site analysis involves determining the locations of restriction sites after the process of digestion by reconstructing their positions based on the lengths of the cut DNA. Using different reaction times with a single enzyme to cut DNA is a technique known as a partial digestion. Determining the exact locations of restriction sites following a partial digestion is challenging due to the computational time required even with the best known practical algorithm. In this paper, we introduce an efficient algorithm to find the exact solution for the partial digest problem. The algorithm is able to find all possible solutions for the input and works by traversing the solution tree with a breadth-first search in two stages and deleting all repeated subproblems. Two types of simulated data, random and Zhang, are used to measure the efficiency of the algorithm. We also apply the algorithm to real data for the Luciferase gene and the E. coli K12 genome. Our algorithm is a fast tool to find the exact solution for the partial digest problem. The percentage of improvement is more than 75% over the best known practical algorithm for the worst case. For large numbers of inputs, our algorithm is able to solve the problem in a suitable time, while the best known practical algorithm is unable.

  14. A new tracking algorithm for multiple colloidal particles close to contact.

    PubMed

    Yücel, Harun; Okumuşoğlu, Nazmi Turan

    2017-10-03

    In this paper, we propose a new algorithm based on radial symmetry center method to track colloidal particles close to contact, where the optical images of the particles start to overlap in digital video microscopy. This overlapping effect is important to observe the pair interaction potential in colloidal studies and it appears as additional interaction in the measurement of the interaction with conventional tracking analysis. The proposed algorithm in this work is simple, fast and applicable for not only two particles but also three and more particles without any modification. The algorithm uses gradient vectors of the particle intensity distribution, which allows us to use a part of the symmetric intensity distribution in the calculation of the actual particle position. In this study, simulations are performed to see the performance of the proposed algorithm for two and three particles, where the simulation images are generated by using fitted curve to experimental particle image for different sized particles . As a result, the algorithm yields the maximum error smaller than 2 nm for 5.53 μm silica particles in contact condition. © 2017 IOP Publishing Ltd.

  15. Dynamic Keypoint-Based Algorithm of Object Tracking

    NASA Astrophysics Data System (ADS)

    Morgacheva, A. I.; Kulikov, V. A.; Kosykh, V. P.

    2017-05-01

    The model of the observed object plays the key role in the task of object tracking. Models as a set of image parts, in particular, keypoints, is more resistant to the changes in shape, texture, angle of view, because local changes apply only to specific parts of the object. On the other hand, any model requires updating as the appearance of the object changes with respect to the camera. In this paper, we propose a dynamic (time-varying) model, based on a set of keypoints. To update the data this model uses the algorithm of rating keypoints and the decision rule, based on a Function of Rival Similarity (FRiS). As a result, at the test set of image sequences the improvement was achieved on average by 9.3% compared to the original algorithm. On some sequences, the improvement was 16% compared to the original algorithm.

  16. National Diffusion Network's Evaluation of the Fast Track Music System 1992-93.

    ERIC Educational Resources Information Center

    Szymczuk, Michael

    This document reports on an evaluation project to determine the effectiveness of the Fast Track method of instrumental music instruction as applied to beginning band instruction. The Fast Track music system is unique because it simultaneously aids both visual and aural learning by using a book and cassette tape approach to instruction. Traditional…

  17. Financing Access and Participation in Primary Education: Is There a "Fast-Track" for Fragile States?

    ERIC Educational Resources Information Center

    Turrent, Victoria

    2011-01-01

    Despite moves to "fast-track" progress towards universal primary education, few fragile states have been able to access Fast Track Initiative (FTI) funding facilities. Weak systems and capacity have made these countries a high-risk proposition for donor investment. The absence of credible education sector plans has meant that the majority of…

  18. "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…

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. 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

  5. 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.

  6. A fast algorithm for computer aided collimation gamma camera (CACAO)

    NASA Astrophysics Data System (ADS)

    Jeanguillaume, C.; Begot, S.; Quartuccio, M.; Douiri, A.; Franck, D.; Pihet, P.; Ballongue, P.

    2000-08-01

    The computer aided collimation gamma camera is aimed at breaking down the resolution sensitivity trade-off of the conventional parallel hole collimator. It uses larger and longer holes, having an added linear movement at the acquisition sequence. A dedicated algorithm including shift and sum, deconvolution, parabolic filtering and rotation is described. Examples of reconstruction are given. This work shows that a simple and fast algorithm, based on a diagonal dominant approximation of the problem can be derived. Its gives a practical solution to the CACAO reconstruction problem.

  7. 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

  8. A fast seed detection using local geometrical feature for automatic tracking of coronary arteries in CTA.

    PubMed

    Han, Dongjin; Doan, Nam-Thai; Shim, Hackjoon; Jeon, Byunghwan; Lee, Hyunna; Hong, Youngtaek; Chang, Hyuk-Jae

    2014-11-01

    We propose a fast seed detection for automatic tracking of coronary arteries in coronary computed tomographic angiography (CCTA). To detect vessel regions, Hessian-based filtering is combined with a new local geometric feature that is based on the similarity of the consecutive cross-sections perpendicular to the vessel direction. It is in turn founded on the prior knowledge that a vessel segment is shaped like a cylinder in axial slices. To improve computational efficiency, an axial slice, which contains part of three main coronary arteries, is selected and regions of interest (ROIs) are extracted in the slice. Only for the voxels belonging to the ROIs, the proposed geometric feature is calculated. With the seed points, which are the centroids of the detected vessel regions, and their vessel directions, vessel tracking method can be used for artery extraction. Here a particle filtering-based tracking algorithm is tested. Using 19 clinical CCTA datasets, it is demonstrated that the proposed method detects seed points and can be used for full automatic coronary artery extraction. ROC (receiver operating characteristic) curve analysis shows the advantages of the proposed method. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  9. Fast algorithms for Quadrature by Expansion I: Globally valid expansions

    NASA Astrophysics Data System (ADS)

    Rachh, Manas; Klöckner, Andreas; O'Neil, Michael

    2017-09-01

    The use of integral equation methods for the efficient numerical solution of PDE boundary value problems requires two main tools: quadrature rules for the evaluation of layer potential integral operators with singular kernels, and fast algorithms for solving the resulting dense linear systems. Classically, these tools were developed separately. In this work, we present a unified numerical scheme based on coupling Quadrature by Expansion, a recent quadrature method, to a customized Fast Multipole Method (FMM) for the Helmholtz equation in two dimensions. The method allows the evaluation of layer potentials in linear-time complexity, anywhere in space, with a uniform, user-chosen level of accuracy as a black-box computational method. Providing this capability requires geometric and algorithmic considerations beyond the needs of standard FMMs as well as careful consideration of the accuracy of multipole translations. We illustrate the speed and accuracy of our method with various numerical examples.

  10. 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.

  11. 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.

  12. Error-Detection Codes: Algorithms and Fast Implementation

    DTIC Science & Technology

    2005-01-01

    information on this or any other computing topic, please visit our Digital Library at www.computer.org/publications/ dlib . NGUYEN: ERROR-DETECTION CODES: ALGORITHMS AND FAST IMPLEMENTATION 11 ...in Appendix C (which can be found on the Computer Society Digital Library at http:// computer.org/tc/archives.htm). In this paper, we focus on code...the Computer Society Digital Library at http://computer.org/ tc/archives.htm) that include theoremproofs, code segments implemented in C programming

  13. 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.

  14. 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.

  15. 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

  16. 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.

  17. A fast learning algorithm for deep belief nets.

    PubMed

    Hinton, Geoffrey E; Osindero, Simon; Teh, Yee-Whye

    2006-07-01

    We show how to use "complementary priors" to eliminate the explaining-away effects that make inference difficult in densely connected belief nets that have many hidden layers. Using complementary priors, we derive a fast, greedy algorithm that can learn deep, directed belief networks one layer at a time, provided the top two layers form an undirected associative memory. The fast, greedy algorithm is used to initialize a slower learning procedure that fine-tunes the weights using a contrastive version of the wake-sleep algorithm. After fine-tuning, a network with three hidden layers forms a very good generative model of the joint distribution of handwritten digit images and their labels. This generative model gives better digit classification than the best discriminative learning algorithms. The low-dimensional manifolds on which the digits lie are modeled by long ravines in the free-energy landscape of the top-level associative memory, and it is easy to explore these ravines by using the directed connections to display what the associative memory has in mind.

  18. 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.

  19. The fast co-adding algorithm of QCT

    NASA Astrophysics Data System (ADS)

    Ping, Yiding; Zhang, Chen

    2017-09-01

    This paper presents a fast co-adding algorithm designed to stack the images coming from different channels of QCT in real-time. The algorithm calculates the transformation coefficients for every single exposure to eliminate the effects of the possible shifts of the lenses. The way of reprojection and co-adding applied here is a linear method similar to Drizzle, and a reasonable simplification is applied to accelerate the computation. All the calculation can be finished in about 100 ms on a 3.4 GHz CPU with 4 cores, which matches the needs for the observation of space debris perfectly, while the limiting magnitude is improved by about 0.8. The co-adding results of our algorithm are very close to SWarp's, even slightly better in terms of SNRs.

  20. A fast distributed algorithm for mining association rules

    SciTech Connect

    Cheung, D.W.; Fu, A.W.; Ng, V.T.

    1996-12-31

    With the existence of many large transaction databases, the huge amounts of data, the high scalability of distributed systems, and the easy partition and distribution of a centralized database, it is important to investigate efficient methods for distributed mining of association rules. This study discloses some interesting relationships between locally large and globally large itemsets and proposes an interesting distributed association rule mining algorithm, FDM (Fast Distributed Mining of association rules), which generates a small number of candidate sets and substantially reduces the number of messages to be passed at mining association rules. Our performance study shows that FDM has a superior performance over the direct application of a typical sequential algorithm Further performance enhancement leads to a few variations of the algorithm.

  1. 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.

  2. 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

  3. 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.

  4. Fast-track Rehabilitation Accelerates Recovery After Laparoscopic Colorectal Surgery

    PubMed Central

    Dakwar, Anthony; Sivkovits, Krina; Mahajna, Ahmad

    2014-01-01

    Background: Fast-track (FT) rehabilitation protocols have been shown to be successful in reducing both hospital stay and postoperative complications, as well as enhancing overall postoperative patient recovery. We are reporting the outcomes of our first group of patients undergoing colorectal surgery following the FT protocol. Patients and Methods: We performed a prospective study of patients, between January 1, 2007 and January 31, 2010, who underwent laparoscopic colorectal resections in accordance with the guidelines of FT rehabilitation protocol. Recovery parameters including time to removal of naso-gastric tube and urinary catheter, time to bowel function and to resume diet, and length of hospital stay were evaluated. Postoperative outcomes, that is, postoperative complications and mortality, reoperations, and readmissions were also studied. Results: A total of 71 patients, 30 women and 41 men, underwent FT rehabilitation for laparoscopic colorectal surgery. The mean age of the patients was 60 ± 16 years. The most common surgical procedures were right hemicolectomy 30% and anterior resection 27%. Liquid and regular diet were initiated on postoperative day 1.2 ± 0.4 and 2.1 ± 0.4, respectively. Overall postoperative morbidity was 8.5%. The mean length of stay was 4.4 ± 1.7 days, with only 3 readmissions. Forty-five patients fulfilled the FT care plan and were discharged on postoperative day 3. No reoperations or mortality were observed. Conclusions: FT rehabilitation results in favorable postoperative outcomes. Our data provides evidence and suggests that FT protocols should be implemented as a reliable method of preparation and recovery for laparoscopic colorectal surgery. PMID:25489207

  5. 3D image registration using a fast noniterative algorithm.

    PubMed

    Zhilkin, P; Alexander, M E

    2000-11-01

    This note describes the implementation of a three-dimensional (3D) registration algorithm, generalizing a previous 2D version [Alexander, Int J Imaging Systems and Technology 1999;10:242-57]. The algorithm solves an integrated form of linearized image matching equation over a set of 3D rectangular sub-volumes ('patches') in the image domain. This integrated form avoids numerical instabilities due to differentiation of a noisy image over a lattice, and in addition renders the algorithm robustness to noise. Registration is implemented by first convolving the unregistered images with a set of computationally fast [O(N)] filters, providing four bandpass images for each input image, and integrating the image matching equation over the given patch. Each filter and each patch together provide an independent set of constraints on the displacement field derived by solving a set of linear regression equations. Furthermore, the filters are implemented at a variety of spatial scales, enabling registration parameters at one scale to be used as an input approximation for deriving refined values of those parameters at a finer scale of resolution. This hierarchical procedure is necessary to avoid false matches occurring. Both downsampled and oversampled (undecimating) filtering is implemented. Although the former is computationally fast, it lacks the translation invariance of the latter. Oversampling is required for accurate interpolation that is used in intermediate stages of the algorithm to reconstruct the partially registered from the unregistered image. However, downsampling is useful, and computationally efficient, for preliminary stages of registration when large mismatches are present. The 3D registration algorithm was implemented using a 12-parameter affine model for the displacement: u(x) = Ax + b. Linear interpolation was used throughout. Accuracy and timing results for registering various multislice images, obtained by scanning a melon and human volunteers in various

  6. Fast track for elderly patients: is it feasible for colorectal surgery?

    PubMed

    Compagna, Rita; Aprea, Giovanni; De Rosa, Davide; Gentile, Maurizio; Cestaro, Giovanni; Vigliotti, Gabriele; Bianco, Tommaso; Massa, Guido; Amato, Maurizio; Massa, Salvatore; Amato, Bruno

    2014-01-01

    Fast-track program has been applied in several surgical fields. However, currently many surgical patients are elderly over 70 years of age, and discussion about the application of such protocols for elderly patients is inadequate. The present study was designed to consider the safety and feasibility of application of a fast-track program after colorectal surgery in elderly patients. A total of 76 elderly patients with colorectal cancer who underwent laparoscopic colorectal resection were randomly assigned to receive either the fast-track care program (n = 40) or the conventional perioperative care protocol (control group, n = 36). The fast track protocol included no preoperative mechanical bowel irrigation, immediate oral alimentation and earlier postoperative ambulation exercise. The length of postoperative hospital stay, the length of time to regain bowel function and the rate of postoperative complications were compared between the two groups. The length of time to regain bowel function, including the passage of flatus [32 (24-40) h vs 42 (32-52) h], and to start a liquid diet (13 [10-16] h v/s 43 [36-50] h) were significantly shorter in patients receiving the fast track care protocol compared with those receiving the conventional care protocol. A shorter duration of postoperative hospital stay was recorded in patients receiving the fast-track program than in those receiving conventional care [6 (5-7) days v/s 9.5 (7-12) days]. A reduced percentage of patients who developed general complications was also observed in the fast-track group (5.0% v/s 18%). Fast-track after laparoscopic colorectal surgery can be safely applied in carefully selected elderly patients older than age 70 years. The fast-track recovery program resulted in a more rapid postoperative recovery, earlier discharge from hospital and fewer general complications compared with a conventional postoperative protocol. Copyright © 2014 Surgical Associates Ltd. Published by Elsevier Ltd. All rights

  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. A fast marching algorithm for the factored eikonal equation

    SciTech Connect

    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.

  10. 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.

  11. 42 CFR 422.626 - Fast-track appeals of service terminations to independent review entities (IREs).

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 42 Public Health 3 2013-10-01 2013-10-01 false Fast-track appeals of service terminations to... ADVANTAGE PROGRAM 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...

  12. 42 CFR 422.626 - Fast-track appeals of service terminations to independent review entities (IREs).

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 42 Public Health 3 2012-10-01 2012-10-01 false Fast-track appeals of service terminations to... ADVANTAGE PROGRAM 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...

  13. 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 organization's...

  14. 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 organization's...

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

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 42 Public Health 3 2014-10-01 2014-10-01 false Fast-track appeals of service terminations to... ADVANTAGE PROGRAM 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...

  16. 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.

  17. 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.

  18. 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.

  19. 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

    ... 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 Customer... on Agency Service Delivery: IHS Web site Customer Service Satisfaction Survey. Abstract: The...

  20. 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.

  1. 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

  2. Vision-based vehicle detection and tracking algorithm design

    NASA Astrophysics Data System (ADS)

    Hwang, Junyeon; Huh, Kunsoo; Lee, Donghwi

    2009-12-01

    The vision-based vehicle detection in front of an ego-vehicle is regarded as promising for driver assistance as well as for autonomous vehicle guidance. The feasibility of vehicle detection in a passenger car requires accurate and robust sensing performance. A multivehicle detection system based on stereo vision has been developed for better accuracy and robustness. This system utilizes morphological filter, feature detector, template matching, and epipolar constraint techniques in order to detect the corresponding pairs of vehicles. After the initial detection, the system executes the tracking algorithm for the vehicles. The proposed system can detect front vehicles such as the leading vehicle and side-lane vehicles. The position parameters of the vehicles located in front are obtained based on the detection information. The proposed vehicle detection system is implemented on a passenger car, and its performance is verified experimentally.

  3. 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.

  4. Microdosimetry calculations for monoenergetic electrons using Geant4-DNA combined with a weighted track sampling algorithm

    NASA Astrophysics Data System (ADS)

    Famulari, Gabriel; Pater, Piotr; Enger, Shirin A.

    2017-07-01

    The aim of this study was to calculate microdosimetric distributions for low energy electrons simulated using the Monte Carlo track structure code Geant4-DNA. Tracks for monoenergetic electrons with kinetic energies ranging from 100 eV to 1 MeV were simulated in an infinite spherical water phantom using the Geant4-DNA extension included in Geant4 toolkit version 10.2 (patch 02). The microdosimetric distributions were obtained through random sampling of transfer points and overlaying scoring volumes within the associated volume of the tracks. Relative frequency distributions of energy deposition f(>E)/f(>0) and dose mean lineal energy (\\bar{y}D ) values were calculated in nanometer-sized spherical and cylindrical targets. The effects of scoring volume and scoring techniques were examined. The results were compared with published data generated using MOCA8B and KURBUC. Geant4-DNA produces a lower frequency of higher energy deposits than MOCA8B. The \\bar{y}D values calculated with Geant4-DNA are smaller than those calculated using MOCA8B and KURBUC. The differences are mainly due to the lower ionization and excitation cross sections of Geant4-DNA for low energy electrons. To a lesser extent, discrepancies can also be attributed to the implementation in this study of a new and fast scoring technique that differs from that used in previous studies. For the same mean chord length (\\bar{l} ), the \\bar{y}D calculated in cylindrical volumes are larger than those calculated in spherical volumes. The discrepancies due to cross sections and scoring geometries increase with decreasing scoring site dimensions. A new set of \\bar{y}D values has been presented for monoenergetic electrons using a fast track sampling algorithm and the most recent physics models implemented in Geant4-DNA. This dataset can be combined with primary electron spectra to predict the radiation quality of photon and electron beams.

  5. 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.

  6. 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.

  7. 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

  8. Fast point cloud registration algorithm using multiscale angle features

    NASA Astrophysics Data System (ADS)

    Lu, Jun; Guo, Congling; Fang, Ying; Xia, Guihua; Wang, Wanjia; Elahi, Ahsan

    2017-05-01

    To fulfill the demands of rapid and real-time three-dimensional optical measurement, a fast point cloud registration algorithm using multiscale axis angle features is proposed. The key point is selected based on the mean value of scalar projections of the vectors from the estimated point to the points in the neighborhood on the normal of the estimated point. This method has a small amount of computation and good discriminating ability. A rotation invariant feature is proposed using the angle information calculated based on multiscale coordinate axis. The feature descriptor of a key point is computed using cosines of the angles between corresponding coordinate axes. Using this method, the surface information around key points is obtained sufficiently in three axes directions and it is easy to recognize. The similarity of descriptors is employed to quickly determine the initial correspondences. The rigid spatial distance invariance and clustering selection method are used to make the corresponding relationships more accurate and evenly distributed. Finally, the rotation matrix and translation vector are determined using the method of singular value decomposition. Experimental results show that the proposed algorithm has high precision, fast matching speed, and good antinoise capability.

  9. A fast poly-energetic iterative FBP algorithm

    NASA Astrophysics Data System (ADS)

    Lin, Yuan; Samei, Ehsan

    2014-04-01

    The beam hardening (BH) effect can influence medical interpretations in two notable ways. First, high attenuation materials, such as bones, can induce strong artifacts, which severely deteriorate the image quality. Second, voxel values can significantly deviate from the real values, which can lead to unreliable quantitative evaluation results. Some iterative methods have been proposed to eliminate the BH effect, but they cannot be widely applied for clinical practice because of the slow computational speed. The purpose of this study was to develop a new fast and practical poly-energetic iterative filtered backward projection algorithm (piFBP). The piFBP is composed of a novel poly-energetic forward projection process and a robust FBP-type backward updating process. In the forward projection process, an adaptive base material decomposition method is presented, based on which diverse body tissues (e.g., lung, fat, breast, soft tissue, and bone) and metal implants can be incorporated to accurately evaluate poly-energetic forward projections. In the backward updating process, one robust and fast FBP-type backward updating equation with a smoothing kernel is introduced to avoid the noise accumulation in the iteration process and to improve the convergence properties. Two phantoms were designed to quantitatively validate our piFBP algorithm in terms of the beam hardening index (BIdx) and the noise index (NIdx). The simulation results showed that piFBP possessed fast convergence speed, as the images could be reconstructed within four iterations. The variation range of the BIdx's of various tissues across phantom size and spectrum were reduced from [-7.5, 17.5] for FBP to [-0.1, 0.1] for piFBP while the NIdx's were maintained in the same low level (about [0.3, 1.7]). When a metal implant presented in a complex phantom, piFBP still had excellent reconstruction performance, as the variation range of the BIdx's of body tissues were reduced from [-2.9, 15.9] for FBP to [-0

  10. 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.

  11. 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

  12. 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

  13. 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.

  14. Time-driven Activity-based Cost of Fast-Track Total Hip and Knee Arthroplasty.

    PubMed

    Andreasen, Signe E; Holm, Henriette B; Jørgensen, Mira; Gromov, Kirill; Kjærsgaard-Andersen, Per; Husted, Henrik

    2017-06-01

    Fast-track total hip and knee arthroplasty (THA and TKA) has been shown to reduce the perioperative convalescence resulting in less postoperative morbidity, earlier fulfillment of functional milestones, and shorter hospital stay. As organizational optimization is also part of the fast-track methodology, the result could be a more cost-effective pathway altogether. As THA and TKA are potentially costly procedures and the numbers are increasing in an economical limited environment, the aim of this study is to present baseline detailed economical calculations of fast-track THA and TKA and compare this between 2 departments with different logistical set-ups. Prospective data collection was analyzed using the time-driven activity-based costing method (TDABC) on time consumed by different staff members involved in patient treatment in the perioperative period of fast-track THA and TKA in 2 Danish orthopedic departments with standardized fast-track settings, but different logistical set-ups. Length of stay was median 2 days in both departments. TDABC revealed minor differences in the perioperative settings between departments, but the total cost excluding the prosthesis was similar at USD 2511 and USD 2551, respectively. Fast-track THA and TKA results in similar cost despite differences in the organizational set-up. Compared to cost associated with longer more conventional published pathways, fast-track is cheaper, which on top of the favorable published clinical outcome adds to cost efficiency and the potential for economic savings. Detailed baseline TDABC calculations are provided for comparison and further optimization of cost-benefit effectiveness. Copyright © 2016 Elsevier Inc. All rights reserved.

  15. 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.

  16. 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

  17. Fast Dating Using Least-Squares Criteria and Algorithms

    PubMed Central

    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

  18. 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.

  19. 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.

  20. 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.

  1. An extended segment pattern dictionary for a pattern matching tracking algorithm at BESIII

    NASA Astrophysics Data System (ADS)

    Ma, Chang-Li; Zhang, Yao; Yuan, Ye; Lu, Xiao-Rui; Zheng, Yang-Heng; He, Kang-Li; Li, Wei-Dong; Liu, Huai-Min; Ma, Qiu-Mei; Wu, Ling-Hui

    2013-06-01

    A pattern matching based tracking algorithm, named MdcPatRec, is used for the reconstruction of charged tracks in the drift chamber of the BESIII detector. This paper addresses the shortage of segment finding in the MdcPatRec algorithm. An extended segment construction scheme and the corresponding pattern dictionary are presented. Evaluation with Monte-Carlo and experimental data show that the new method can achieve higher efficiency for low transverse momentum tracks.

  2. A Rule-based Track Anomaly Detection Algorithm for Maritime Force Protection

    DTIC Science & Technology

    2014-08-01

    UNCLASSIFIED UNCLASSIFIED A Rule- based Track Anomaly Detection Algorithm for Maritime Force Protection S.Boinepalli and...detection tool using a Rule- based Algorithm that can detect anomalies in a set of pre-recorded tracks using their curvature, speed and weave. We...Australia 2014 AR 016-049 August 2014 APPROVED FOR PUBLIC RELEASE UNCLASSIFIED UNCLASSIFIED A Rule- based Track Anomaly Detection

  3. 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

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

    PubMed

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

    2017-04-01

    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.

  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. 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.

  7. 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.

  8. 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.

  9. 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.

  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. Design of a hardware track finder (Fast Tracker) for the ATLAS trigger

    NASA Astrophysics Data System (ADS)

    Cavaliere, V.; Adelman, J.; Albicocco, P.; Alison, J.; Ancu, L. S.; Anderson, J.; Andari, N.; Andreani, A.; Andreazza, A.; Annovi, A.; Antonelli, M.; Asbah, N.; Atkinson, M.; Baines, J.; Barberio, E.; Beccherle, R.; Beretta, M.; Bertolucci, F.; Biesuz, N. V.; Blair, R.; Bogdan, M.; Boveia, A.; Britzger, D.; Bryant, P.; Burghgrave, B.; Calderini, G.; Camplani, A.; Cavasinni, V.; Chakraborty, D.; Chang, P.; Cheng, Y.; Citraro, S.; Citterio, M.; Crescioli, F.; Dawe, N.; Dell'Orso, M.; Donati, S.; Dondero, P.; Drake, G.; Gadomski, S.; Gatta, M.; Gentsos, C.; Giannetti, P.; Gkaitatzis, S.; Gramling, J.; Howarth, J. W.; Iizawa, T.; Ilic, N.; Jiang, Z.; Kaji, T.; Kasten, M.; Kawaguchi, Y.; Kim, Y. K.; Kimura, N.; Klimkovich, T.; Kolb, M.; Kordas, K.; Krizka, K.; Kubota, T.; Lanza, A.; Li, H. L.; Liberali, V.; Lisovyi, M.; Liu, L.; Love, J.; Luciano, P.; Luongo, C.; Magalotti, D.; Maznas, I.; Meroni, C.; Mitani, T.; Nasimi, H.; Negri, A.; Neroutsos, P.; Neubauer, M.; Nikolaidis, S.; Okumura, Y.; Pandini, C.; Petridou, C.; Piendibene, M.; Proudfoot, J.; Rados, P.; Roda, C.; Rossi, E.; Sakurai, Y.; Sampsonidis, D.; Saxon, J.; Schmitt, S.; Schoening, A.; Shochet, M.; Shojaii, S.; Soltveit, H.; Sotiropoulou, C. L.; Stabile, A.; Swiatlowski, M.; Tang, F.; Taylor, P. T.; Testa, M.; Tompkins, L.; Vercesi, V.; Volpi, G.; Wang, R.; Watari, R.; Webster, J.; Wu, X.; Yorita, K.; Yurkewicz, A.; Zeng, J. C.; Zhang, J.; Zou, R.

    2016-02-01

    The use of tracking information at the trigger level in the LHC Run II period is crucial for the trigger and data acquisition system and will be even more so as contemporary collisions that occur at every bunch crossing will increase in Run III. The Fast TracKer is part of the ATLAS trigger upgrade project; it is a hardware processor that will provide every Level-1 accepted event (100 kHz) and within 100μs, full tracking information for tracks with momentum as low as 1 GeV . Providing fast, extensive access to tracking information, with resolution comparable to the offline reconstruction, FTK will help in precise detection of the primary and secondary vertices to ensure robust selections and improve the trigger performance.

  12. 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.

  13. 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

  14. [A "fast track" to improve management of neovascular age related macular degeneration].

    PubMed

    Krivosic, V; Philippakis, E; Couturier, A; Dupas, B; Erginay, A; Desmettre, T; Streho, M; Bonnin, S; Manne, V; Jouvaud, S; Gualino, V; Durand, D; Tadayoni, R

    2017-10-01

    To evaluate the role of a fast track for management of patients with neovascular age- related macular degeneration (nARMD) treated by intravitreal injection of anti-VEGF. The records of 100 patients in the chronic maintenance phase of intravitreal anti-VEGF followed in the fast track and 63 patients followed in the standard protocol for at least 12 months were retrospectively analyzed. Patients in the fast track underwent visual acuity (VA) testing by ETDRS, optical coherence tomography (OCT) and a physician assessment. The injection was performed the same day whenever possible. The primary endpoint to evaluate patient adherence was the time between the ideal date of visit or injection prescribed by the physician and the actual date of administration. The mean time between the ideal date of visit or injection prescribed by the physician and the actual date of administration was 4.1±7.5 days for the patients followed in the fast track and 5.6±18.7 days for the patients followed in the standard protocol. Mean VA remained stable for the patients followed in the fast track: 20/50 (20/800 to 20/20) at baseline vs. 20/50 (20/800 to 20/16) at the conclusion of follow-up. It dropped from 40/50 at baseline to 20/63 at the conclusion of follow-up for the patients followed in the standard protocol. In the context of a fast track, it was possible to improve the adherence of nARMD patients and maintain their VA gain or stabilization achieved after the induction phase. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  15. 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.

  16. Patient experience in fast-track hip and knee arthroplasty--a qualitative study.

    PubMed

    Specht, Kirsten; Kjaersgaard-Andersen, Per; Pedersen, Birthe D

    2016-03-01

    To explore the lived experience of patients in fast-track primary unilateral total hip and knee arthroplasty from the first visit at the outpatient clinic until discharge. Fast-track has resulted in increased effectiveness, including faster recovery and shorter length of stay to about two days after hip and knee arthroplasty. However, the patient perspective in fast-track with a median length of stay of less than three days has been less investigated. A qualitative design. A phenomenological-hermeneutic approach was used, inspired by Paul Ricoeur's theory of narrative and interpretation. Eight patients were included. Semi-structured interviews and participant observation were performed. Three themes emerged: dealing with pain; feelings of confidence or uncertainty - the meaning of information; and readiness for discharge. Generally, the patients were resistant to taking analgesics and found it difficult to find out when to take supplementary analgesics; therefore, nursing staff needed enough expertise to take responsibility. Factors that increased patients' confidence: information about fast-track, meeting staff before admission and involving relatives. In contrast, incorrect or conflicting information and a lack of respect for privacy led to uncertainty. In preparing for early discharge, sufficient pain management, feeling well-rested and optimal use of time during hospitalisation were important. The study shows the importance of dealing with pain and getting the right information and support to have confidence in the fast-track programme, to be ready for discharge and to manage postoperatively at home. In fast-track focusing on early discharge, there is an increased need for evidence-based nursing practice, including a qualified judgement of what is best for the patient in certain situations. The knowledge should be gleaned from: research; the patients' expertise, understanding and situation; and nurses' knowledge, skills and experience. © 2015 John Wiley & Sons

  17. 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.

  18. Characterization of fast acoustic wave propagation using OFDR with double interrogation and frequency tracking

    NASA Astrophysics Data System (ADS)

    Gabai, Haniel; Eyal, Avishay

    2014-05-01

    A highly sensitive OFDR system capable of detecting and tracking fast acoustic wave propagation is described. The system was tested by dropping a screw (50gr) and a paperclip (<5gr) at one end of an 18m PVC pipe. The sensing fiber detected the wave propagation (v ≍ 1750m/s) along the entire pipe. Fast phase variations due to the impact of the screw led to a transient shift in the frequency of the interrogating light which corrupted the observed response. By tracking the beat frequencies of predefined reflectors and extracting their amplitudes significant improvement in the system's output was obtained.

  19. Relative age and fast tracking of elite major junior ice hockey players.

    PubMed

    Sherar, Lauren B; Bruner, Mark W; Munroe-Chandler, Krista J; Baxter-Jones, Adam D G

    2007-06-01

    Investigations in a variety of chronologically grouped team sports have reported that elite young athletes were more likely born in the early months of the selection year, a phenomenon known as the relative age effect. The present study investigated the birth dates and developmental paths of 238 (15 to 20 years old) Major Junior 'A' hockey players from the Ontario Hockey League to determine if a relative age effect still exists in elite junior hockey and if the path to elite sport was accelerated (i.e., fast tracked). The results identified a relative age effect in elite hockey although it is only apparent among individuals who fast track.

  20. Quantifying saccades while walking: validity of a novel velocity-based algorithm for mobile eye tracking.

    PubMed

    Stuart, Samuel; Galna, Brook; Lord, Sue; Rochester, Lynn; Godfrey, Alan

    2014-01-01

    We validate a novel algorithm to detect saccades from raw data obtained during walking from a mobile infra-red eye-tracking device. The algorithm was based on a velocity threshold detection method, which excluded artefacts such as blinks and flickers using specific criteria. Mobile infra-red eye-tracking was performed with a group of healthy older adults (n=5) and Parkinson's disease (n=5) subjects. Saccades determined from raw eye tracker data obtained during walking using the algorithm were compared to a ground truth dataset defined as frame-by-frame visual inspection of raw eye-tracking videos. 100 trials from 10 subjects were analyzed and compared. The algorithm was highly reliable when compared to the ground truth (ICC(2,1) = 0.94), with an overall correct saccade detection percentage of 85%. This provides a simple yet robust algorithm for the analysis of mobile eye-tracking data.

  1. 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.

  2. 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)

  3. 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.

  4. Fast Fluorescence Laser Tracking Microrheometry, I: Instrument Development

    PubMed Central

    Jonas, Maxine; Huang, Hayden; Kamm, Roger D.; So, Peter T. C.

    2008-01-01

    To gain insight into cellular mechanotransduction pathways, we have developed a fluorescence laser tracking microrheometer (FLTM) to measure material rheological features on micrometer length scales using fluorescent microspheres as tracer particles. The statistical analysis of the Brownian motion of a particle quantifies the viscoelastic properties of the probe's environment, parameterized by the frequency-dependent complex shear modulus G*(ω). This FLTM has nanometer spatial resolution over a frequency range extending from 1 Hz to 50 kHz. In this work, we first describe the consecutive stages of instrument design, development, and optimization. We subsequently demonstrate the accuracy of the FLTM by reproducing satisfactorily the known rheological characteristics of purely viscous glycerol solutions and cross-linked polyacrylamide polymer networks. An upcoming companion article will illustrate the use of FLTM in studying the solid-like versus liquid-like rheological properties of fibroblast cytoskeletons in living biological samples. PMID:17965137

  5. 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

  6. Tracking changing environments: innovators are fast, but not flexible learners.

    PubMed

    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.

  7. Biased Randomized Algorithm for Fast Model-Based Diagnosis

    NASA Technical Reports Server (NTRS)

    Williams, Colin; Vartan, Farrokh

    2005-01-01

    A biased randomized algorithm has been developed to enable the rapid computational solution of a propositional- satisfiability (SAT) problem equivalent to a diagnosis problem. The closest competing methods of automated diagnosis are described in the preceding article "Fast Algorithms for Model-Based Diagnosis" and "Two Methods of Efficient Solution of the Hitting-Set Problem" (NPO-30584), which appears elsewhere in this issue. It is necessary to recapitulate some of the information from the cited articles as a prerequisite to a description of the present method. As used here, "diagnosis" signifies, more precisely, a type of model-based diagnosis in which one explores any logical inconsistencies between the observed and expected behaviors of an engineering system. The function of each component and the interconnections among all the components of the engineering system are represented as a logical system. Hence, the expected behavior of the engineering system is represented as a set of logical consequences. Faulty components lead to inconsistency between the observed and expected behaviors of the system, represented by logical inconsistencies. Diagnosis - the task of finding the faulty components - reduces to finding the components, the abnormalities of which could explain all the logical inconsistencies. One seeks a minimal set of faulty components (denoted a minimal diagnosis), because the trivial solution, in which all components are deemed to be faulty, always explains all inconsistencies. In the methods of the cited articles, the minimal-diagnosis problem is treated as equivalent to a minimal-hitting-set problem, which is translated from a combinatorial to a computational problem by mapping it onto the Boolean-satisfiability and integer-programming problems. The integer-programming approach taken in one of the prior methods is complete (in the sense that it is guaranteed to find a solution if one exists) and slow and yields a lower bound on the size of the

  8. 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.

  9. 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.

  10. 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.

  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. 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.

  13. Data Mining Meets Performance Evaluation: Fast Algorithms for Modeling Bursty Traffic

    DTIC Science & Technology

    2001-04-01

    Data Mining Meets Performance Evaluation: Fast Algorithms for Modeling Bursty Traffic Mengzhi Wang Tara Madhyastha Ngai Hang Chan Spiros...2001 4. TITLE AND SUBTITLE Data Mining Meets Performance Evaluation: Fast Algorithms for Modeling Bursty Traffic 5a. CONTRACT NUMBER 5b. GRANT

  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. 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.

  16. 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.

  17. FAST TRACK PAPER: Receiver function decomposition of OBC data: theory

    NASA Astrophysics Data System (ADS)

    Edme, Pascal; Singh, Satish C.

    2009-06-01

    This paper deals with theoretical aspects of wavefield decomposition of Ocean Bottom Cable (OBC) data in the τ-p domain, considering a horizontally layered medium. We present both the acoustic decomposition and elastic decomposition procedures in a simple and compatible way. Acoustic decomposition aims at estimating the primary upgoing P wavefield just above the ocean-bottom, whereas elastic decomposition aims at estimating the primary upgoing P and S wavefields just below the ocean-bottom. Specific issues due to the interference phenomena at the receiver level are considered. Our motivation is to introduce the two-step decomposition scheme called `receiver function' (RF) decomposition that aims at determining the primary upgoing P and S wavefields (RFP and RFS, free of any water layer multiples). We show that elastic decomposition is a necessary step (acting as pre-conditioning) before applying the multiple removal step by predictive deconvolution. We show the applicability of our algorithm on a synthetic data example.

  18. 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.

  19. 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.

  20. 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…

  1. "Joined up" Thinking? Unsupported "Fast-Track" Transitions in the Context of Parental Substance Use

    ERIC Educational Resources Information Center

    Wilson, Sarah; Cunningham-Burley, Sarah; Bancroft, Angus; Backett-Milburn, Kathryn

    2008-01-01

    Recent policy responses to the risks entailed in "fast-track" school-work transitions have targeted careleavers and young people identified as "not in education, employment or training" (NEET). However, this approach has been criticised as diverting attention away from the fragile circumstances of others who may receive little…

  2. 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…

  3. 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…

  4. Alternative Methods for Handling Attrition: An Illustration Using Data From the Fast Track Evaluation

    ERIC Educational Resources Information Center

    Foster, E. Michael; Fang, Grace Y.

    2004-01-01

    Using data from the evaluation of the Fast Track intervention, this article illustrates three methods for handling attrition. Multiple imputation and ignorable maximum likelihood estimation produce estimates that are similar to those based on listwise-deleted data. A panel selection model that allows for selective dropout reveals that highly…

  5. 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…

  6. Fast Track Initiative: Building a Global Compact for Education. Education Notes

    ERIC Educational Resources Information Center

    Human Development Network Education, 2005

    2005-01-01

    This note series is intended to summarize lessons learned and key policy findings on the World Bank's work in education. "Fast Track Initiative" ("FTI") was launched in 2002 as a partnership between donor and developing countries to accelerate progress towards the Millennium Development Goal (MDG) of universal primary education. "FTI" is built on…

  7. 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…

  8. 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…

  9. Optimising fast track care for proximal femoral fracture patients using modified early warning score.

    PubMed

    Ollivere, B; Rollins, K; Brankin, R; Wood, M; Brammar, T J; Wimhurst, J

    2012-05-01

    The care for patients with a proximal femoral fracture has been dramatically overhauled with the introduction of 'fast track' protocols and the British Orthopaedic Association guidance in 2007. Fast track pathways focus on streamlining patient flow through the emergency department where the guidance addresses standards of care. We prospectively examined the impact these protocols have on patient care and propose an alternative 'streamed care' pathway to provide improved medical care within existing resource constraints. Data surrounding the treatment of 156 consecutive patients managed at 4 centres were collated prospectively. Management of patients with a traditional fast track protocol allowed 17% of patients to leave the emergency department with undiagnosed serious medical pathology and 32% with suboptimal fluid resuscitation. A streamed care pathway based on the modified early warning score was developed and employed for 48 further patients as an alternative to the traditional fast track system. The streamed care pathway improved initial care significantly by treating patients according to their physiological parameters on admission. Targeted medical reviews on admission instead of the following day reduced the rates of undiagnosed medical pathology to 2% (p = 0.0068) and inadequate fluid resuscitation to 11% (p < 0.0001). Implementation of a streamed care pathway can allow protocol driven improvement to initial care for patients with a proximal femoral fracture and results in improved access to initial specialist medical care.

  10. Exploration and extension of an improved Riemann track fitting algorithm

    NASA Astrophysics Data System (ADS)

    Strandlie, A.; Frühwirth, R.

    2017-09-01

    Recently, a new Riemann track fit which operates on translated and scaled measurements has been proposed. This study shows that the new Riemann fit is virtually as precise as popular approaches such as the Kalman filter or an iterative non-linear track fitting procedure, and significantly more precise than other, non-iterative circular track fitting approaches over a large range of measurement uncertainties. The fit is then extended in two directions: first, the measurements are allowed to lie on plane sensors of arbitrary orientation; second, the full error propagation from the measurements to the estimated circle parameters is computed. The covariance matrix of the estimated track parameters can therefore be computed without recourse to asymptotic properties, and is consequently valid for any number of observation. It does, however, assume normally distributed measurement errors. The calculations are validated on a simulated track sample and show excellent agreement with the theoretical expectations.

  11. Fast Track Extubation In Adult Patients On Pump Open Heart Surgery At A Tertiary Care Hospital.

    PubMed

    Akhtar, Mohammad Irfan; Sharif, Hasanat; Hamid, Mohammad; Samad, Khalid; Khan, Fazal Hameed

    2016-01-01

    Fast-track cardiac surgery programs have been established as the standard of cardiac surgical care. Studies have shown that early extubation in elective cardiac surgery patients, including coronary and non-coronary open-heart surgery patients does not increase perioperative morbidity and mortality. The objective of this observational study was to determine the success and failure profile of fast track extubation (FTE) practice in adult open-heart surgical patients. The study was conducted at cardiac operating room and Cardiac Intensive Care Unit (CICU) of a tertiary care hospital for a period of nine months, i.e., from Oct 2014 to June-2015. All on pump elective adult cardiac surgery patients including isolated CABG, isolated Valve replacements, combined procedures and aortic root replacements were enrolled in the study. Standardized anesthetic technique was adopted. Surgical and bypass techniques were tailored according to the procedure. Success of Fast track extubation was defined as extubation within 6 hours of arrival in CICU. A total of 290 patients were recruited. The average age of the patients was 56.3±10.5 years. There were 77.6% male and 22.4% female patients. Overall success rate was 51.9% and failure rate was 48.1%. The peri-operative renal insufficiency, cross clamp time and CICU stay (hours) were significantly lower in success group. Re-intubation rate was 0.74%. The perioperative parameters were significantly better in success group and the safety was also demonstrated in the patients who were fast tracked successfully. To implement the practice in its full capacity and benefit, a fast track protocol needs to be devised to standardize the current practices and to disseminate the strategy among junior anaesthesiologists, perfusionists and nursing staff.

  12. A modified fast-track program for pancreatic surgery: a prospective single-center experience.

    PubMed

    di Sebastiano, Pierluigi; Festa, Leonardina; De Bonis, Antonio; Ciuffreda, Andrea; Valvano, Maria Rosa; Andriulli, Angelo; di Mola, F Francesco

    2011-03-01

    The objective of this study is to evaluate the impact of a fast-track protocol in a high-volume center for patients with pancreatic disorders. The concept of fast-track surgery allowing accelerated postoperative recovery is accepted in colorectal surgery, but efficacy data are only preliminary for patients undergoing major pancreatic surgery. We aimed to evaluate the impact of a modified fast-track protocol in a high-volume center for patients with pancreatic disorders. Between February 2005 and January 2010, 145 subjects had resective pancreatic surgery and were enrolled in the program. Essential features of the program were no preanaesthetic medication, upper and lower air-warming device, avoidance of excessive i.v. fluids perioperatively, effective control of pain, early reinstitution of oral feeding, and immediate mobilization and restoration of bowel function following surgery. Outcome measures were postoperative complications such as pancreatic fistula, delayed gastric emptying, biliary leak, intra-abdominal abscess, post-pancreatectomy hemorrhage, acute pancreatitis, wound infection, 30-day mortality, postoperative hospital stay, and readmission rates. On average, patients were discharged on postoperative day 10 (range 6-69), with a 30-day readmission rate of 6.2%. Percentage of patients with at least one complication was 38.6%. Pancreatic anastomotic leakage occurred in seven of 101 pancreatico-jejunostomies, and biliary leak in three of 109 biliary jejunostomies. Postoperative hemorrhage occurred in ten (6.9%) patients and wound infection in nine (6.2%) cases. In-hospital mortality was 2.7%. Fast-track parameters, such as normal food and first stool, correlated significantly with early discharge (<0.05). At multivariate analysis, lack of jaundice, and resumption of normal diet by the 5th postoperative day were independent factors of early discharge. Fast-track programs are feasible, easy, and also applicable for patients undergoing a major surgery such as

  13. The yield of colorectal cancer among fast track patients with normocytic and microcytic anaemia.

    PubMed

    Panagiotopoulou, I G; Fitzrol, D; Parker, R A; Kuzhively, J; Luscombe, N; Wells, A D; Menon, M; Bajwa, F M; Watson, M A

    2014-05-01

    We receive fast track referrals on the basis of iron deficiency anaemia (IDA) for patients with normocytic anaemia or for patients with no iron studies. This study examined the yield of colorectal cancer (CRC) among fast track patients to ascertain whether awaiting confirmation of IDA is necessary prior to performing bowel investigations. A review was undertaken of 321 and 930 consecutive fast track referrals from Centre A and Centre B respectively. Contingency tables were analysed using Fisher's exact test. Logistic regression analyses were performed to investigate significant predictors of CRC. Overall, 229 patients were included from Centre A and 689 from Centre B. The odds ratio for microcytic anaemia versus normocytic anaemia in the outcome of CRC was 1.3 (95% confidence interval [CI]: 0.5-3.9) for Centre A and 1.6 (95% CI: 0.8-3.3) for Centre B. In a logistic regression analysis (Centre B only), no significant difference in CRC rates was seen between microcytic and normocytic anaemia (adjusted odds ratio: 1.9, 95% CI: 0.9-3.9). There was no statistically significant difference in the yield of CRC between microcytic and normocytic anaemia (p=0.515, Fisher's exact test) in patients with anaemia only and no colorectal symptoms. Finally, CRC cases were seen in both microcytic and normocytic groups with or without low ferritin. There is no significant difference in the yield of CRC between fast track patients with microcytic and normocytic anaemia. This study provides insufficient evidence to support awaiting confirmation of IDA in fast track patients with normocytic anaemia prior to requesting bowel investigations.

  14. The yield of colorectal cancer among fast track patients with normocytic and microcytic anaemia

    PubMed Central

    Fitzrol, D; Parker, RA; Kuzhively, J; Luscombe, N; Wells, AD; Menon, M; Bajwa, FM; Watson, MA

    2014-01-01

    Introduction We receive fast track referrals on the basis of iron deficiency anaemia (IDA) for patients with normocytic anaemia or for patients with no iron studies. This study examined the yield of colorectal cancer (CRC) among fast track patients to ascertain whether awaiting confirmation of IDA is necessary prior to performing bowel investigations. Methods A review was undertaken of 321 and 930 consecutive fast track referrals from Centre A and Centre B respectively. Contingency tables were analysed using Fisher’s exact test. Logistic regression analyses were performed to investigate significant predictors of CRC. Results Overall, 229 patients were included from Centre A and 689 from Centre B. The odds ratio for microcytic anaemia versus normocytic anaemia in the outcome of CRC was 1.3 (95% confidence interval [CI]: 0.5–3.9) for Centre A and 1.6 (95% CI: 0.8–3.3) for Centre B. In a logistic regression analysis (Centre B only), no significant difference in CRC rates was seen between microcytic and normocytic anaemia (adjusted odds ratio: 1.9, 95% CI: 0.9–3.9). There was no statistically significant difference in the yield of CRC between microcytic and normocytic anaemia (p=0.515, Fisher’s exact test) in patients with anaemia only and no colorectal symptoms. Finally, CRC cases were seen in both microcytic and normocytic groups with or without low ferritin. Conclusions There is no significant difference in the yield of CRC between fast track patients with microcytic and normocytic anaemia. This study provides insufficient evidence to support awaiting confirmation of IDA in fast track patients with normocytic anaemia prior to requesting bowel investigations. PMID:24780021

  15. Life in the Fast Track: How States Seek to Balance Incentives and Quality in Alternative Teacher Certification Programs

    ERIC Educational Resources Information Center

    Johnson, Susan Moore; Birkeland, Sarah E.; Peske, Heather G.

    2005-01-01

    The prospect of overseeing the rapid preparation of many participants in fast-track alternative certification programs presents several challenges for state education officials who seek to maintain, or even enhance, the quality of the state's teaching force. This study examined a range of fast-track alternative teacher certification programs in 11…

  16. 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.

  17. 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.

  18. 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.

  19. An Improved Wake Vortex Tracking Algorithm for Multiple Aircraft

    NASA Technical Reports Server (NTRS)

    Switzer, George F.; Proctor, Fred H.; Ahmad, Nashat N.; LimonDuparcmeur, Fanny M.

    2010-01-01

    The accurate tracking of vortex evolution from Large Eddy Simulation (LES) data is a complex and computationally intensive problem. The vortex tracking requires the analysis of very large three-dimensional and time-varying datasets. The complexity of the problem is further compounded by the fact that these vortices are embedded in a background turbulence field, and they may interact with the ground surface. Another level of complication can arise, if vortices from multiple aircrafts are simulated. This paper presents a new technique for post-processing LES data to obtain wake vortex tracks and wake intensities. The new approach isolates vortices by defining "regions of interest" (ROI) around each vortex and has the ability to identify vortex pairs from multiple aircraft. The paper describes the new methodology for tracking wake vortices and presents application of the technique for single and multiple aircraft.

  20. A fast algorithm for body extraction in CT volumes

    NASA Astrophysics Data System (ADS)

    Guétat, Grégoire; Stoeckel, Jonathan; Wolf, Matthias; Krishnan, Arun

    2006-03-01

    The Computed Tomography (CT) modality shows not only the body of the patient in the volumes it generates, but also the clothing, the cushion and the table. This might be a problem especially for two applications. The first is 3D visualization, where the table has high density parts that might hide regions of interest. The second is registration of acquisitions obtained at different time points; indeed, the table and cushions might be visible in one data set only, and their positions and shapes may vary, making the registration less accurate. An automatic approach for extracting the body would solve those problems. It should be robust, reliable, and fast. We therefore propose a multi-scale method based on deformable models. The idea is to move a surface across the image that attaches to the boundaries of the body. We iteratively compute forces which take into account local information around the surface. Those make it move through the table but ensure that it stops when coming close to the body. Our model has elastic properties; moreover, we take into account the fact that some regions in the volume convey more information than others by giving them more weight. This is done by using normalized convolution when regularizing the surface. The algorithm*, tested on a database of over a hundred volumes of whole body, chest or lower abdomen, has proven to be very efficient, even for volumes with up to 900 slices, providing accurate results in an average time of 6 seconds. It is also robust against noise and variations of scale and table's shape.

  1. A rate-constrained fast full-search algorithm based on block sum pyramid.

    PubMed

    Song, Byung Cheol; Chun, Kang-Wook; Ra, Jong Beom

    2005-03-01

    This paper presents a fast full-search algorithm (FSA) for rate-constrained motion estimation. The proposed algorithm, which is based on the block sum pyramid frame structure, successively eliminates unnecessary search positions according to rate-constrained criterion. This algorithm provides the identical estimation performance to a conventional FSA having rate constraint, while achieving considerable reduction in computation.

  2. 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.

  3. A new hybrid algorithm for computing a fast discrete Fourier transform

    NASA Technical Reports Server (NTRS)

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

    1978-01-01

    For certain long transform lengths, Winograd's algorithm for computing the discrete Fourier transform is extended considerably. This is accomplished by performing the cyclic convolution, required by Winograd's method, with the Mersenne-prime number theoretic transform. This new algorithm requires fewer multiplications than either the standard fast Fourier transform or Winograd's more conventional algorithm.

  4. Fast and stable algorithms for computing the principal square root of a complex matrix

    NASA Technical Reports Server (NTRS)

    Shieh, Leang S.; Lian, Sui R.; Mcinnis, Bayliss C.

    1987-01-01

    This note presents recursive algorithms that are rapidly convergent and more stable for finding the principal square root of a complex matrix. Also, the developed algorithms are utilized to derive the fast and stable matrix sign algorithms which are useful in developing applications to control system problems.

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. 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).

  11. 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

  12. 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.

  13. Optimising fast track care for proximal femoral fracture patients using modified early warning score

    PubMed Central

    Ollivere, B

    2012-01-01

    INTRODUCTION The care for patients with a proximal femoral fracture has been dramatically overhauled with the introduction of ‘fast track’ protocols and the British Orthopaedic Association guidance in 2007. Fast track pathways focus on streamlining patient flow through the emergency department where the guidance addresses standards of care. We prospectively examined the impact these protocols have on patient care and propose an alternative ‘streamed care’ pathway to provide improved medical care within existing resource constraints. METHODS Data surrounding the treatment of 156 consecutive patients managed at 4 centres were collated prospectively. Management of patients with a traditional fast track protocol allowed 17% of patients to leave the emergency department with undiagnosed serious medical pathology and 32% with suboptimal fluid resuscitation. A streamed care pathway based on the modified early warning score was developed and employed for 48 further patients as an alternative to the traditional fast track system. RESULTS The streamed care pathway improved initial care significantly by treating patients according to their physiological parameters on admission. Targeted medical reviews on admission instead of the following day reduced the rates of undiagnosed medical pathology to 2% (p=0.0068) and inadequate fluid resuscitation to 11% (p<0.0001). CONCLUSIONS Implementation of a streamed care pathway can allow protocol driven improvement to initial care for patients with a proximal femoral fracture and results in improved access to initial specialist medical care. PMID:22613306

  14. 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

  15. A fast portable implementation of the Secure Hash Algorithm, III.

    SciTech Connect

    McCurley, Kevin S.

    1992-10-01

    In 1992, NIST announced a proposed standard for a collision-free hash function. The algorithm for producing the hash value is known as the Secure Hash Algorithm (SHA), and the standard using the algorithm in known as the Secure Hash Standard (SHS). Later, an announcement was made that a scientist at NSA had discovered a weakness in the original algorithm. A revision to this standard was then announced as FIPS 180-1, and includes a slight change to the algorithm that eliminates the weakness. This new algorithm is called SHA-1. In this report we describe a portable and efficient implementation of SHA-1 in the C language. Performance information is given, as well as tips for porting the code to other architectures. We conclude with some observations on the efficiency of the algorithm, and a discussion of how the efficiency of SHA might be improved.

  16. 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.

  17. 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

  18. 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.

  19. 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.

  20. On extending the complex FastICA algorithms to noisy data.

    PubMed

    Ruan, Zongli; Li, Liping; Qian, Guobing

    2014-12-01

    Independent component analysis (ICA) methods are widely applied to modern digital signal processing. The complex-valued FastICA algorithms are one type of the most significant methods. However, the complex ICA model usually omits the noise. In this paper, we discuss two complex FastICA algorithms for noisy data, where the cost functions are based on kurtosis and negentropy respectively. The nc-FastICA and KM-F algorithms are modified to separate noisy data. At the same time, we also give the stability conditions of cost functions. Simulations are presented to illustrate the effectiveness of our methods. Copyright © 2014 Elsevier Ltd. All rights reserved.

  1. 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

  2. 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.

  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. 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.

  5. 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.

  6. A fast algorithm for automatic detection of ionospheric disturbances: DROT

    NASA Astrophysics Data System (ADS)

    Efendi, Emre; Arikan, Feza

    2017-06-01

    Solar, geomagnetic, gravitational and seismic activities cause disturbances in the ionospheric region of upper atmosphere that may disrupt or lower the quality of space based communication, navigation and positioning system signals. These disturbances can be categorized with respect to their amplitude, duration and frequency. Typically in the literature, ionospheric disturbances are investigated with gradient based methods on Total Electron Content (TEC) data estimated from ground based dual frequency Global Positioning System (GPS) receivers. In this study, a fast algorithm is developed for the automatic detection of the variability in Slant TEC (STEC) data. STEC is defined as the total number of electrons on the ray path between the ground based receiver and GPS satellite in the orbital height of 20,000 km. The developed method, namely, Differential Rate of TEC (DROT), is based on Rate of Tec (ROT) method. ROT is widely used in the literature and it is usually applied to Vertical TEC (VTEC) that corresponds to the projection of STEC to the vertical direction along the ray path at the Ionospheric Pierce Point (IPP) using a mapping function. The developed DROT method can be defined as the normalized metric norm between the ROT and its baseband trend structure. In this study, the performance of DROT is determined using synthetic data with variable bounds on the parameter set of amplitude, frequency and duration of disturbance. It is observed that DROT method can detect disturbances in three categories. For DROT values less than 50%, there is no significant disturbance in STEC data. For DROT values between 50% and 70%, a medium scale disturbance can be observed. For DROT values over 70%, severe disturbances such as Large Scale Traveling Ionospheric Disturbances (LSTIDs) can be observed. DROT method is highly sensitive to the amplitude of the wave-like oscillations. For a disturbance amplitude as low as 1.01 TECU, the disturbances that have durations longer than or

  7. 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.

  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. Evaluation of a robust fiducial tracking algorithm for image-guided radiosurgery

    NASA Astrophysics Data System (ADS)

    Hatipoglu, Serkan; Mu, Zhiping; Fu, Dongshan; Kuduvalli, Gopinath

    2007-03-01

    Fiducial tracking is a widely used method in image guided procedures such as image guided radiosurgery and radiotherapy. Our group has developed a new fiducial identification algorithm, concurrent Viterbi with association (CVA) algorithm, based on a modified Hidden Markov Model (HMM), and reported our initial results previously. In this paper, we present an extensive performance evaluation of this novel algorithm using phantom testing and clinical images acquired during patient treatment. For a common three-fiducial case, the algorithm execution time is less than two seconds. Testing with a collection of images from more than 35 patient treatments, with a total of more than 10000 image pairs, we find that the success rate of the new algorithm is better than 99%. In the tracking test using a phantom, the phantom is moved to a variety of positions with translations up to 8 mm and rotations up to 4 degree. The new algorithm correctly tracks the phantom motion, with an average translation error of less than 0.5 mm and rotation error less than 0.5 degrees. These results demonstrate that the new algorithm is very efficient, robust, easy to use, and capable of tracking fiducials in a large region of interest (ROI) at a very high success rate with high accuracy.

  10. A fast algorithm for nonnegative matrix factorization and its convergence.

    PubMed

    Li, Li-Xin; Wu, Lin; Zhang, Hui-Sheng; Wu, Fang-Xiang

    2014-10-01

    Nonnegative matrix factorization (NMF) has recently become a very popular unsupervised learning method because of its representational properties of factors and simple multiplicative update algorithms for solving the NMF. However, for the common NMF approach of minimizing the Euclidean distance between approximate and true values, the convergence of multiplicative update algorithms has not been well resolved. This paper first discusses the convergence of existing multiplicative update algorithms. We then propose a new multiplicative update algorithm for minimizing the Euclidean distance between approximate and true values. Based on the optimization principle and the auxiliary function method, we prove that our new algorithm not only converges to a stationary point, but also does faster than existing ones. To verify our theoretical results, the experiments on three data sets have been conducted by comparing our proposed algorithm with other existing methods.

  11. 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

  12. [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.

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

    PubMed

    Sorensen, Lucy C; Dodge, Kenneth A

    2016-01-01

    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 general 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 general and mental health problems. © 2015 The Authors. Child Development © 2015 Society for Research in Child Development, Inc.

  14. 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

  15. 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

  16. A Novel Validation Algorithm Allows for Automated Cell Tracking and the Extraction of Biologically Meaningful Parameters

    PubMed Central

    Madany Mamlouk, Amir; Schicktanz, Simone; Kruse, Charli

    2011-01-01

    Automated microscopy is currently the only method to non-invasively and label-free observe complex multi-cellular processes, such as cell migration, cell cycle, and cell differentiation. Extracting biological information from a time-series of micrographs requires each cell to be recognized and followed through sequential microscopic snapshots. Although recent attempts to automatize this process resulted in ever improving cell detection rates, manual identification of identical cells is still the most reliable technique. However, its tedious and subjective nature prevented tracking from becoming a standardized tool for the investigation of cell cultures. Here, we present a novel method to accomplish automated cell tracking with a reliability comparable to manual tracking. Previously, automated cell tracking could not rival the reliability of manual tracking because, in contrast to the human way of solving this task, none of the algorithms had an independent quality control mechanism; they missed validation. Thus, instead of trying to improve the cell detection or tracking rates, we proceeded from the idea to automatically inspect the tracking results and accept only those of high trustworthiness, while rejecting all other results. This validation algorithm works independently of the quality of cell detection and tracking through a systematic search for tracking errors. It is based only on very general assumptions about the spatiotemporal contiguity of cell paths. While traditional tracking often aims to yield genealogic information about single cells, the natural outcome of a validated cell tracking algorithm turns out to be a set of complete, but often unconnected cell paths, i.e. records of cells from mitosis to mitosis. This is a consequence of the fact that the validation algorithm takes complete paths as the unit of rejection/acceptance. The resulting set of complete paths can be used to automatically extract important biological parameters with high

  17. 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.

  18. 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

  19. Implementation and audit of 'Fast-Track Surgery' in gynaecological oncology surgery.

    PubMed

    Sidhu, Verinder S; Lancaster, Letitia; Elliott, David; Brand, Alison H

    2012-08-01

    Fast-track surgery is a multidisciplinary approach to surgery that results in faster recovery from surgery and decreased length of stay (LOS). The aims of this study were as follows: (i) to report on the processes required for the introduction of fast-track surgery to a gynaecological oncology unit and (ii) to report the results of a clinical audit conducted after the protocol's implementation. A fast-track protocol, specific to our unit, was developed after a series of multidisciplinary meetings. The protocol, agreed upon by those involved in the care of women in our unit, was then introduced into clinical practice. An audit was conducted of all women undergoing laparotomy, with known or suspected malignancy. Information on LOS, complication and readmission rates was collected. Descriptive statistics and Poisson regression were used for statistical analysis. The developed protocol involved a multidisciplinary approach to pre-, intra- and postoperative care. The audit included 104 consecutive women over a 6-month period, who were followed for 6 weeks postoperatively. The median LOS was 4 days. The readmission rate was 7% and the complication rate was 19% (1% intraoperative, 4% major and 14% minor). Multivariate analysis revealed that increased duration of surgery and increasing age were predictors of longer LOS. The development of a fast-track protocol is achievable in a gynaecological oncology unit, with input from a multidisciplinary team. Effective implementation of the protocol can result in a short LOS, with acceptable complication and readmission rates when applied non-selectively to gynaecological oncology patients. © 2012 The Authors ANZJOG © 2012 The Royal Australian and New Zealand College of Obstetricians and Gynaecologists.

  20. Setting up a fast-track insulin start clinic for type 2 diabetes.

    PubMed

    Burden, Mary; Byard, Caroline; Gregory, Robert; Khulpateea, Anita; Burden, Andrew

    When people with established type 2 diabetes first need insulin therapy there is often a delay in accessing services. Since the report of the UK Prospective Diabetes Study was published it has been recognised that people with type 2 diabetes have a progressive disease and a need for increasing treatment. The authors set up a fast-track service to enable GPs and practice nurses to refer to a nurse-led service at the diabetes centre.

  1. 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

  2. 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…

  3. 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

  4. Maintaining Unity - relatives in older patients' fast-track treatment programmes. A grounded theory study.

    PubMed

    Berthelsen, Connie Bøttcher; Lindhardt, Tove; Frederiksen, Kirsten

    2014-12-01

    To generate a substantive grounded theory of relatives' pattern of behaviour in older patients' fast-track treatment programmes during total hip or knee replacement. Fast-track treatment programmes are designed to make total hip and knee replacements more efficient through recovery improvements. The support of relatives during older patients' trajectory is important. However, knowledge is needed on the relatives' pattern of behaviour to strengthen their involvement in fast-track treatment programmes. We used a Glaserian grounded theory approach based on a systematic generation of theory from data to explain the latent pattern of behaviour of relatives. Data were collected from 2010-2011 in orthopaedic wards at two Danish university hospitals and consisted of 14 non-participant observations, 14 postobservational interviews and five interviews. Seven relatives of patients over 70 years of age participated. The constant comparative method was the guiding principle for simultaneous data collection, data analysis and coding, while theoretically sampling and writing memos. Maintaining Unity emerged as the relatives' pattern of behaviour through which they resolved their main concern: preventing the patients from feeling alone. The relatives resolved their main concern through three interchangeable behavioural modes: Protecting Mode, by providing loving and respectful support; Substituting Mode, with practical and cognitive support; and an Adapting Mode, by trying to fit in with the patients' and health professionals' requirements. The substantive theory of Maintaining Unity offers knowledge of relatives' strong desire to provide compassionate and loving support for the older patients during fast-track treatment programmes. © 2014 John Wiley & Sons Ltd.

  5. 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…

  6. 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.

  7. 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.

  8. A fast algorithm for reconstruction of spectrally sparse signals in super-resolution

    NASA Astrophysics Data System (ADS)

    Cai, Jian-Feng; Liu, Suhui; Xu, Weiyu

    2015-08-01

    We propose a fast algorithm to reconstruct spectrally sparse signals from a small number of randomly observed time domain samples. Different from conventional compressed sensing where frequencies are discretized, we consider the super-resolution case where the frequencies can be any values in the normalized continuous frequency domain [0; 1). We first convert our signal recovery problem into a low rank Hankel matrix completion problem, for which we then propose an efficient feasible point algorithm named projected Wirtinger gradient algorithm(PWGA). The algorithm can be further accelerated by a scheme inspired by the fast iterative shrinkage-thresholding algorithm (FISTA). Numerical experiments are provided to illustrate the effectiveness of our proposed algorithm. Different from earlier approaches, our algorithm can solve problems of large scale efficiently.

  9. 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.

  10. Fast Optimal Load Balancing Algorithms for 1D Partitioning

    SciTech Connect

    Pinar, Ali; Aykanat, Cevdet

    2002-12-09

    One-dimensional decomposition of nonuniform workload arrays for optimal load balancing is investigated. The problem has been studied in the literature as ''chains-on-chains partitioning'' problem. Despite extensive research efforts, heuristics are still used in parallel computing community with the ''hope'' of good decompositions and the ''myth'' of exact algorithms being hard to implement and not runtime efficient. The main objective of this paper is to show that using exact algorithms instead of heuristics yields significant load balance improvements with negligible increase in preprocessing time. We provide detailed pseudocodes of our algorithms so that our results can be easily reproduced. We start with a review of literature on chains-on-chains partitioning problem. We propose improvements on these algorithms as well as efficient implementation tips. We also introduce novel algorithms, which are asymptotically and runtime efficient. We experimented with data sets from two different applications: Sparse matrix computations and Direct volume rendering. Experiments showed that the proposed algorithms are 100 times faster than a single sparse-matrix vector multiplication for 64-way decompositions on average. Experiments also verify that load balance can be significantly improved by using exact algorithms instead of heuristics. These two findings show that exact algorithms with efficient implementations discussed in this paper can effectively replace heuristics.

  11. An active contour-based SSD algorithm for tracking a moving object

    NASA Astrophysics Data System (ADS)

    Han, Youngjoon; Song, Piljae; Chung, Hwanik; Hahn, Hernsoo

    2004-05-01

    Since the shape of a 3D object moving in 3D space changes a lot in 2D image due to translation and rotation, it is very difficult to track the object using the SSD algorithm which finds the matching object in the input image using the template of the moving object. To solve the problem, this paper presents an enhanced SSD algorithm which updates the template based on an extended snake algorithm adaptive to the shape variation. The proposed snake algorithm uses the derivative of the area as the constraint energy to determine the boundary of an interested area considering the progressive variation of the shape. The performance of the proposed algorithm has been proved by the experiments where a mobile robot with one camera tracks a 3D target object translating and rotating arbitrarily in the 3D workspace.

  12. 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.

  13. GPU-based fast pencil beam algorithm for proton therapy.

    PubMed

    Fujimoto, Rintaro; Kurihara, Tsuneya; Nagamine, Yoshihiko

    2011-03-07

    Performance of a treatment planning system is an essential factor in making sophisticated plans. The dose calculation is a major time-consuming process in planning operations. The standard algorithm for proton dose calculations is the pencil beam algorithm which produces relatively accurate results, but is time consuming. In order to shorten the computational time, we have developed a GPU (graphics processing unit)-based pencil beam algorithm. We have implemented this algorithm and calculated dose distributions in the case of a water phantom. The results were compared to those obtained by a traditional method with respect to the computational time and discrepancy between the two methods. The new algorithm shows 5-20 times faster performance using the NVIDIA GeForce GTX 480 card in comparison with the Intel Core-i7 920 processor. The maximum discrepancy of the dose distribution is within 0.2%. Our results show that GPUs are effective for proton dose calculations.

  14. GPU-based fast pencil beam algorithm for proton therapy

    NASA Astrophysics Data System (ADS)

    Fujimoto, Rintaro; Kurihara, Tsuneya; Nagamine, Yoshihiko

    2011-03-01

    Performance of a treatment planning system is an essential factor in making sophisticated plans. The dose calculation is a major time-consuming process in planning operations. The standard algorithm for proton dose calculations is the pencil beam algorithm which produces relatively accurate results, but is time consuming. In order to shorten the computational time, we have developed a GPU (graphics processing unit)-based pencil beam algorithm. We have implemented this algorithm and calculated dose distributions in the case of a water phantom. The results were compared to those obtained by a traditional method with respect to the computational time and discrepancy between the two methods. The new algorithm shows 5-20 times faster performance using the NVIDIA GeForce GTX 480 card in comparison with the Intel Core-i7 920 processor. The maximum discrepancy of the dose distribution is within 0.2%. Our results show that GPUs are effective for proton dose calculations.

  15. 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.

  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 Algorithms for Earth Mover Distance Based on Optimal Transport and L1 Regularization II

    DTIC Science & Technology

    2016-09-01

    FAST ALGORITHMS FOR EARTH MOVER DISTANCE BASED ON OPTIMAL TRANSPORT AND L1 REGULARIZATION II WUCHEN LI, STANLEY OSHER, AND WILFRID GANGBO Abstract...We modify a fast algorithm which we designed in [15] for computing the Earth mover’s distance (EMD), whose cost is a Manhattan metric. From the theory...and converges very rapidly. Several numerical examples are presented. 1. Introduction The Earth Mover’s distance (EMD), also named the Monge problem

  18. 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

  19. 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.

  20. 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

  1. 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

  2. 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.

  3. 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.

  4. An Extended Kalman Filter-Based Attitude Tracking Algorithm for Star Sensors.

    PubMed

    Li, Jian; Wei, Xinguo; Zhang, Guangjun

    2017-08-21

    Efficiency and reliability are key issues when a star sensor operates in tracking mode. In the case of high attitude dynamics, the performance of existing attitude tracking algorithms degenerates rapidly. In this paper an extended Kalman filtering-based attitude tracking algorithm is presented. The star sensor is modeled as a nonlinear stochastic system with the state estimate providing the three degree-of-freedom attitude quaternion and angular velocity. The star positions in the star image are predicted and measured to estimate the optimal attitude. Furthermore, all the cataloged stars observed in the sensor field-of-view according the predicted image motion are accessed using a catalog partition table to speed up the tracking, called star mapping. Software simulation and night-sky experiment are performed to validate the efficiency and reliability of the proposed method.

  5. An Extended Kalman Filter-Based Attitude Tracking Algorithm for Star Sensors

    PubMed Central

    Li, Jian; Wei, Xinguo; Zhang, Guangjun

    2017-01-01

    Efficiency and reliability are key issues when a star sensor operates in tracking mode. In the case of high attitude dynamics, the performance of existing attitude tracking algorithms degenerates rapidly. In this paper an extended Kalman filtering-based attitude tracking algorithm is presented. The star sensor is modeled as a nonlinear stochastic system with the state estimate providing the three degree-of-freedom attitude quaternion and angular velocity. The star positions in the star image are predicted and measured to estimate the optimal attitude. Furthermore, all the cataloged stars observed in the sensor field-of-view according the predicted image motion are accessed using a catalog partition table to speed up the tracking, called star mapping. Software simulation and night-sky experiment are performed to validate the efficiency and reliability of the proposed method. PMID:28825684

  6. 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

  7. 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

  8. 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.

  9. 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.

  10. A hand tracking algorithm with particle filter and improved GVF snake model

    NASA Astrophysics Data System (ADS)

    Sun, Yi-qi; Wu, Ai-guo; Dong, Na; Shao, Yi-zhe

    2017-07-01

    To solve the problem that the accurate information of hand cannot be obtained by particle filter, a hand tracking algorithm based on particle filter combined with skin-color adaptive gradient vector flow (GVF) snake model is proposed. Adaptive GVF and skin color adaptive external guidance force are introduced to the traditional GVF snake model, guiding the curve to quickly converge to the deep concave region of hand contour and obtaining the complex hand contour accurately. This algorithm realizes a real-time correction of the particle filter parameters, avoiding the particle drift phenomenon. Experimental results show that the proposed algorithm can reduce the root mean square error of the hand tracking by 53%, and improve the accuracy of hand tracking in the case of complex and moving background, even with a large range of occlusion.

  11. The implementation of an automated tracking algorithm for the track detection of migratory anticyclones affecting the Mediterranean

    NASA Astrophysics Data System (ADS)

    Hatzaki, Maria; Flocas, Elena A.; Simmonds, Ian; Kouroutzoglou, John; Keay, Kevin; Rudeva, Irina

    2013-04-01

    Migratory cyclones and anticyclones mainly account for the short-term weather variations in extra-tropical regions. By contrast to cyclones that have drawn major scientific attention due to their direct link to active weather and precipitation, climatological studies on anticyclones are limited, even though they also are associated with extreme weather phenomena and play an important role in global and regional climate. This is especially true for the Mediterranean, a region particularly vulnerable to climate change, and the little research which has been done is essentially confined to the manual analysis of synoptic charts. For the construction of a comprehensive climatology of migratory anticyclonic systems in the Mediterranean using an objective methodology, the Melbourne University automatic tracking algorithm is applied, based to the ERA-Interim reanalysis mean sea level pressure database. The algorithm's reliability in accurately capturing the weather patterns and synoptic climatology of the transient activity has been widely proven. This algorithm has been extensively applied for cyclone studies worldwide and it has been also successfully applied for the Mediterranean, though its use for anticyclone tracking is limited to the Southern Hemisphere. In this study the performance of the tracking algorithm under different data resolutions and different choices of parameter settings in the scheme is examined. Our focus is on the appropriate modification of the algorithm in order to efficiently capture the individual characteristics of the anticyclonic tracks in the Mediterranean, a closed basin with complex topography. We show that the number of the detected anticyclonic centers and the resulting tracks largely depend upon the data resolution and the search radius. We also find that different scale anticyclones and secondary centers that lie within larger anticyclone structures can be adequately represented; this is important, since the extensions of major

  12. 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.

  13. 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.

  14. [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.

  15. A fast recursive algorithm for molecular dynamics simulation

    NASA Technical Reports Server (NTRS)

    Jain, A.; Vaidehi, N.; Rodriguez, G.

    1993-01-01

    The present recursive algorithm for solving molecular systems' dynamical equations of motion employs internal variable models that reduce such simulations' computation time by an order of magnitude, relative to Cartesian models. Extensive use is made of spatial operator methods recently developed for analysis and simulation of the dynamics of multibody systems. A factor-of-450 speedup over the conventional O(N-cubed) algorithm is demonstrated for the case of a polypeptide molecule with 400 residues.

  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 asynchronous updating algorithms for k-shell indices

    NASA Astrophysics Data System (ADS)

    Lee, Yan-Li; Zhou, Tao

    2017-09-01

    Identifying influential nodes in networks is a significant and challenging task. Among many centrality indices, the k-shell index performs very well in finding out influential spreaders. However, the traditional method for calculating the k-shell indices of nodes needs the global topological information, which limits its applications in large-scale dynamically growing networks. Recently, Lü et al. [Nature Commun. 7 (2016) 10168] proposed a novel asynchronous algorithm to calculate the k-shell indices, which is suitable to deal with large-scale growing networks. In this paper, we propose two algorithms to select nodes and update their intermediate values towards the k-shell indices, which can help in accelerating the convergence of the calculation of k-shell indices. The former algorithm takes into account the degrees of nodes while the latter algorithm prefers to choose the node whose neighbors' values have been changed recently. We test these two methods on four real networks and four artificial networks. The results suggest that the two algorithms can respectively reduce the convergence time up to 75.4% and 92.9% in average, compared with the original asynchronous updating algorithm.

  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. Hybrid Tracking Algorithm Improvements and Cluster Analysis Methods.

    DTIC Science & Technology

    1982-02-26

    IrcrApidSine1I0 rcr n 50Tao ae Asi ea 82 1It;_ r I Contract N00014-78-C-0670 Tracor Project 036-013 Document No. T82-AU-9054-U FINAL REPORT: HYBRID TRACKING...Approved by: H Don Cooper Frank C. Harris Project Engineer Department Director System Modeling Department 26 February 1982 IhacaAppid Sce e Tracor, Inc...Wilson______________ P. PIEI1ORMING ORGANIZATION NAME AND ADDRESS t0. PROGRAM ELEMENT. PROJECT . T ASK AREA A WORK UNIT NUMBERS Tracor Applied

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

    PubMed

    Kang, Suk-Ju

    2016-12-27

    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.

  1. 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

  2. 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

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. 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

  8. 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.

  9. 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.

  10. A new hybrid algorithm for computing a fast discrete Fourier transform

    NASA Technical Reports Server (NTRS)

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

    1979-01-01

    In this paper for certain long transform lengths, Winograd's algorithm for computing the discrete Fourier transform (DFT) is extended considerably. This is accomplished by performing the cyclic convolution, required by Winograd's method, with the Mersenne prime number-theoretic transform developed originally by Rader. This new algorithm requires fewer multiplications than either the standard fast Fourier transform (FFT) or Winograd's more conventional algorithm. However, more additions are required.

  11. Learning local appearances with sparse representation for robust and fast visual tracking.

    PubMed

    Bai, Tianxiang; Li, You-Fu; Zhou, Xiaolong

    2015-04-01

    In this paper, we present a novel appearance model using sparse representation and online dictionary learning techniques for visual tracking. In our approach, the visual appearance is represented by sparse representation, and the online dictionary learning strategy is used to adapt the appearance variations during tracking. We unify the sparse representation and online dictionary learning by defining a sparsity consistency constraint that facilitates the generative and discriminative capabilities of the appearance model. An elastic-net constraint is enforced during the dictionary learning stage to capture the characteristics of the local appearances that are insensitive to partial occlusions. Hence, the target appearance is effectively recovered from the corruptions using the sparse coefficients with respect to the learned sparse bases containing local appearances. In the proposed method, the dictionary is undercomplete and can thus be efficiently implemented for tracking. Moreover, we employ a median absolute deviation based robust similarity metric to eliminate the outliers and evaluate the likelihood between the observations and the model. Finally, we integrate the proposed appearance model with the particle filter framework to form a robust visual tracking algorithm. Experiments on benchmark video sequences show that the proposed appearance model outperforms the other state-of-the-art approaches in tracking performance.

  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. Vehicle detection algorithm based on light pairing and tracking at nighttime

    NASA Astrophysics Data System (ADS)

    Wan, Weibing; Fang, Tao; Li, Shuguang

    2011-10-01

    Detecting a vehicle to obtain traffic information at nighttime is difficult. This study proposes a vehicle detection algorithm, called the headlight extraction, pairing, and tracking (HLEPT) algorithm, which can acquire traffic information in the rain at nighttime by identifying vehicles through the location of their headlights and other indicative lights. A knowledge-based connected-component procedure, in which vehicles are located by grouping their lights and estimating their features, is proposed. The features of a complex nighttime traffic scene were also analyzed. The HLEPT algorithm includes a headlight extraction algorithm, as well as regulations for the pairing and grouping of lights and light tracking using a Kanade-Lucas-Tomasi tracker to measure traffic flow and velocity. Experimental results demonstrate the feasibility and effectiveness of the proposed approach on vehicle detection in the rain at nighttime.

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. Fast Multidimensional Nearest Neighbor Search Algorithm Using Priority Queue

    NASA Astrophysics Data System (ADS)

    Ajioka, Shiro; Tsuge, Satoru; Shishibori, Masami; Kita, Kenji

    Nearest neighbor search in high dimensional spaces is an interesting and important problem which is relevant for a wide variety of applications, including multimedia information retrieval, data mining, and pattern recognition. For such applications, the curse of high dimensionality tends to be a major obstacle in the development of efficient search methods. This paper addresses the problem of designing an efficient algorithm for high dimensional nearest neighbor search using a priority queue. The proposed algorithm is based on a simple linear search algorithm and eliminates unnecessary arithmetic operations from distance computations between multidimensional vectors. Moreover, we propose two techniques, a dimensional sorting method and a PCA-based method, to accelerate multidimensional search. Experimental results indicate that our scheme scales well even for a very large number of dimensions.

  19. A fast image simulation algorithm for scanning transmission electron microscopy.

    PubMed

    Ophus, Colin

    2017-01-01

    Image simulation for scanning transmission electron microscopy at atomic resolution for samples with realistic dimensions can require very large computation times using existing simulation algorithms. We present a new algorithm named PRISM that combines features of the two most commonly used algorithms, namely the Bloch wave and multislice methods. PRISM uses a Fourier interpolation factor f that has typical values of 4-20 for atomic resolution simulations. We show that in many cases PRISM can provide a speedup that scales with f(4) compared to multislice simulations, with a negligible loss of accuracy. We demonstrate the usefulness of this method with large-scale scanning transmission electron microscopy image simulations of a crystalline nanoparticle on an amorphous carbon substrate.

  20. 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.

  1. 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

  2. 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.

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

    PubMed

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

    2016-09-01

    Inclusion of inhomogeneity corrections in intensity modulated small fields always makes conformal irradiation of lung tumor very complicated in accurate dose delivery. 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. 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. 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. 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.

  4. 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

  5. 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.

  6. [Reduction of Treatment Duration in Periprosthetic Infection with a Fast-Track Concept Is Economically Not Feasible].

    PubMed

    Lieb, E; Hanstein, T; Schuerings, M; Trampuz, A; Perka, C

    2015-12-01

    In the two stage revision of periprosthetic joint infection (PJI), the prosthesis-free interval may be reduced to 2-3 weeks (fast-track). This is an innovative approach with clear advantages for both the patient and health insurance stakeholders. The prosthesis-free interval with conventional two-stage PJI slow-track procedures lasts 6-12 weeks. In Germany, the patient spends this time either at home or in a geriatric hospital. This period is mainly used to manage infections. The patient is then readmitted for implantation of the revision prosthesis. This readmission then leads to additional reimbursement, as this is formally a new insurance case. Despite this double payment, the costs for the treatment of such complex diseases are not covered by the German DRG system. If hospitals are to implement the proven fast-track concept, they need to invest in a multidisciplinary medical team. This would be responsible for defining infections, selecting patients, and improving diagnosis and antimicrobial therapy and should thus improve the rates of cure of infections. However, the G-DRG reimbursement system treats the two surgeries as a single case, providing that less than 30 days lies between the two interventions; as a result, the reimbursement is inadequate for patients with the fast-track interval. We analysed the theoretical financial deficit for a hospital and describe the cost-saving potential for payers applying the fast-track interval rather than the slow-track approach in selected PJI patients, using a comprehensive and individualised treatment concept. Our analysis covered thirty-two consecutive patients with infected joint prosthesis (17 hips, 15 knee) admitted to our hospital from January 2011 to December 2012 undergoing a two-stage exchange (ICD-10-GM: T84.5). We excluded patients who underwent only one hospital admission during the analysed time frame or who were admitted to another hospital. Patients treated with joint fusion and patients who died were also

  7. A new algorithm to detect coronary boundaries: the maximal differential curve tracking

    NASA Astrophysics Data System (ADS)

    Chen, Xiaodong; Yu, Daoyin; Xu, Zhi

    2004-03-01

    An algorithm for the detection of the coronary boundaries in single-view angiograms is proposed. The algorithm, the maximal differential curve tracking (MDCT), uses the directional gray value information available in digital angiograms. The search strategy, which is based on differential method, finds a maximal cost edge along a coronary artery. The results show this method is robust and the detected boundary is continuous. It is beneficial to measure the vessel diameter and locate the stenosis.

  8. 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.

  9. 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

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. Fast Monte Carlo algorithm for supercooled soft spheres.

    PubMed

    Grigera, T S; Parisi, G

    2001-04-01

    We present a nonlocal Monte Carlo algorithm with particle swaps that greatly accelerates thermalization of soft sphere binary mixtures in the glassy region. Our first results show that thermalization of systems of hundreds of particles is achievable, and find behavior compatible with a thermodynamic glass transition.

  15. 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.

  16. Fast algorithms for combustion kinetics calculations: A comparison

    NASA Technical Reports Server (NTRS)

    Radhakrishnan, K.

    1984-01-01

    To identify the fastest algorithm currently available for the numerical integration of chemical kinetic rate equations, several algorithms were examined. Findings to date are summarized. The algorithms examined include two general-purpose codes EPISODE and LSODE and three special-purpose (for chemical kinetic calculations) codes CHEMEQ, CRK1D, and GCKP84. In addition, an explicit Runge-Kutta-Merson differential equation solver (IMSL Routine DASCRU) is used to illustrate the problems associated with integrating chemical kinetic rate equations by a classical method. Algorithms were applied to two test problems drawn from combustion kinetics. These problems included all three combustion regimes: induction, heat release and equilibration. Variations of the temperature and species mole fraction are given with time for test problems 1 and 2, respectively. Both test problems were integrated over a time interval of 1 ms in order to obtain near-equilibration of all species and temperature. Of the codes examined in this study, only CREK1D and GCDP84 were written explicitly for integrating exothermic, non-isothermal combustion rate equations. These therefore have built-in procedures for calculating the temperature.

  17. 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

  18. 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.

  19. Tracking lung tumour motion using a dynamically weighted optical flow algorithm and electronic portal imaging device

    NASA Astrophysics Data System (ADS)

    Teo, P. T.; Crow, R.; Van Nest, S.; Sasaki, D.; Pistorius, S.

    2013-07-01

    This paper investigates the feasibility and accuracy of using a computer vision algorithm and electronic portal images to track the motion of a tumour-like target from a breathing phantom. A multi-resolution optical flow algorithm that incorporates weighting based on the differences between frames was used to obtain a set of vectors corresponding to the motion between two frames. A global value representing the average motion was obtained by computing the average weighted mean from the set of vectors. The tracking accuracy of the optical flow algorithm as a function of the breathing rate and target visibility was investigated. Synthetic images with different contrast-to-noise ratios (CNR) were created, and motions were tracked. The accuracy of the proposed algorithm was compared against potentiometer measurements giving average position errors of 0.6 ± 0.2 mm, 0.2 ± 0.2 mm and 0.1 ± 0.1 mm with average velocity errors of 0.2 ± 0.2 mm s-1, 0.4 ± 0.3 mm s-1 and 0.6 ± 0.5 mm s-1 for 6, 12 and 16 breaths min-1 motions, respectively. The cumulative average position error reduces more rapidly with the greater number of breathing cycles present in higher breathing rates. As the CNR increases from 4.27 to 5.6, the average relative error approaches zero and the errors are less dependent on the velocity. When tracking a tumour on a patient's digitally reconstructed radiograph images, a high correlation was obtained between the dynamically weighted optical flow algorithm, a manual delineation process and a centroid tracking algorithm. While the accuracy of our approach is similar to that of other methods, the benefits are that it does not require manual delineation of the target and can therefore provide accurate real-time motion estimation during treatment.

  20. 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.

  1. Fast Multiscale Algorithms for Wave Propagation in Heterogeneous Environments

    DTIC Science & Technology

    2016-01-07

    SIAM J Scientific Computing (08 2013) Xi Chen, Daniel Appelo, Thomas Hagstrom. A Hybrid Hermite - Discontinuous Galerkin Method forHyperbolic Systems...SECURITY CLASSIFICATION OF: The objective of this research project was to further develop and integrate numerical methods for the fast and accurate...seek methods which are not only efficient, but which are reliable in that both their stability and the accuracy of the results are essentially

  2. Algorithm for fast event parameters estimation on GEM acquired data

    NASA Astrophysics Data System (ADS)

    Linczuk, Paweł; Krawczyk, Rafał D.; Poźniak, Krzysztof T.; Kasprowicz, Grzegorz; Wojeński, Andrzej; Chernyshova, Maryna; Czarski, Tomasz

    2016-09-01

    We present study of a software-hardware environment for developing fast computation with high throughput and low latency methods, which can be used as back-end in High Energy Physics (HEP) and other High Performance Computing (HPC) systems, based on high amount of input from electronic sensor based front-end. There is a parallelization possibilities discussion and testing on Intel HPC solutions with consideration of applications with Gas Electron Multiplier (GEM) measurement systems presented in this paper.

  3. 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.

  4. 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.

  5. 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.

  6. 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

  7. 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…

  8. 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…

  9. Fast-track vs. delayed insertion of the levonorgestrel-releasing intrauterine system after early medical abortion - a randomized trial.

    PubMed

    Korjamo, Riina; Mentula, Maarit; Heikinheimo, Oskari

    2017-08-05

    To compare levonorgestrel (LNG) 52-mg intrauterine system (IUS) expulsion rates with fast-track (≤3 days) or delayed (2-4 weeks) insertion following mifepristone and misoprostol medical abortion. In this pilot trial, we randomized 108 women at ≤63 days' gestation to fast-track (n=55) or delayed (n=53) insertion. Follow-up visits occurred at 2-4 weeks, 3 months and 1 year. We assessed total and partial expulsion at 3 months and 1 year, adverse effects and bleeding profiles. We had follow-up data at 3 months and 1 year for 41 (74.5%) and 37 (69.8%) women in the fast-track group and 31 (56.4%) and 28 (52.8%) women in the delayed group. By 3 months, expulsion occurred in six (12.5%) women after fast-track and one (2.3%) woman after delayed insertion [risk ratio (RR) 5.50, 95% confidence interval (CI) 0.69-43.90]; most (n=5) of these were partial expulsions in the fast-track group. By 1 year, expulsion had occurred in seven (14.6%) and five (11.5%) women in the fast-track and delayed groups, respectively (RR 1.28, 95% CI 0.44-3.75). We found no differences in rates of vacuum aspiration, residual tissue, infection and bleeding or bleeding patterns within 3 months of insertion. Fast-track insertion of the LNG 52-mg IUS after medical abortion is feasible but may result in higher expulsion rates compared to delayed insertion. Due to lack of statistical power and high lost-to-follow-up rates, we were unable to fully address this question. Fast-tract initiation of LNG 52-mg IUS contraception after medical abortion is feasible. It results in higher expulsion rates than delayed insertion but may improve postabortal intrauterine contraception uptake. Copyright © 2017 Elsevier Inc. All rights reserved.

  10. "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…

  11. 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.

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

    PubMed

    Saa, Pedro A; Nielsen, Lars K

    2016-12-15

    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. 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. 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). lars.nielsen@uq.edu.auSupplementary information: Supplementary data are available at Bioinformatics online. © The Author 2016. Published by Oxford University Press.

  13. 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.

  14. 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.

  15. FPGA design and implementation of a fast pixel purity index algorithm for endmember extraction in hyperspectral imagery

    NASA Astrophysics Data System (ADS)

    Valencia, David; Plaza, Antonio; Vega-Rodríguez, Miguel A.; Pérez, Rosa M.

    2005-11-01

    Hyperspectral imagery is a class of image data which is used in many scientific areas, most notably, medical imaging and remote sensing. It is characterized by a wealth of spatial and spectral information. Over the last years, many algorithms have been developed with the purpose of finding "spectral endmembers," which are assumed to be pure signatures in remotely sensed hyperspectral data sets. Such pure signatures can then be used to estimate the abundance or concentration of materials in mixed pixels, thus allowing sub-pixel analysis which is crucial in many remote sensing applications due to current sensor optics and configuration. One of the most popular endmember extraction algorithms has been the pixel purity index (PPI), available from Kodak's Research Systems ENVI software package. This algorithm is very time consuming, a fact that has generally prevented its exploitation in valid response times in a wide range of applications, including environmental monitoring, military applications or hazard and threat assessment/tracking (including wildland fire detection, oil spill mapping and chemical and biological standoff detection). Field programmable gate arrays (FPGAs) are hardware components with millions of gates. Their reprogrammability and high computational power makes them particularly attractive in remote sensing applications which require a response in near real-time. In this paper, we present an FPGA design for implementation of PPI algorithm which takes advantage of a recently developed fast PPI (FPPI) algorithm that relies on software-based optimization. The proposed FPGA design represents our first step toward the development of a new reconfigurable system for fast, onboard analysis of remotely sensed hyperspectral imagery.

  16. 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.

  17. 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.

  18. New color-based tracking algorithm for joints of the upper extremities

    NASA Astrophysics Data System (ADS)

    Wu, Xiangping; Chow, Daniel H. K.; Zheng, Xiaoxiang

    2007-11-01

    To track the joints of the upper limb of stroke sufferers for rehabilitation assessment, a new tracking algorithm which utilizes a developed color-based particle filter and a novel strategy for handling occlusions is proposed in this paper. Objects are represented by their color histogram models and particle filter is introduced to track the objects within a probability framework. Kalman filter, as a local optimizer, is integrated into the sampling stage of the particle filter that steers samples to a region with high likelihood and therefore fewer samples is required. A color clustering method and anatomic constraints are used in dealing with occlusion problem. Compared with the general basic particle filtering method, the experimental results show that the new algorithm has reduced the number of samples and hence the computational consumption, and has achieved better abilities of handling complete occlusion over a few frames.

  19. 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.

  20. A fast biologically inspired algorithm for recurrent motion estimation.

    PubMed

    Bayerl, Pierre; Neumann, Heiko

    2007-02-01

    We have previously developed a neurodynamical model of motion segregation in cortical visual area V1 and MT of the dorsal stream. The model explains how motion ambiguities caused by the motion aperture problem can be solved for coherently moving objects of arbitrary size by means of cortical mechanisms. The major bottleneck in the development of a reliable biologically inspired technical system with real-time motion analysis capabilities based on this neural model is the amount of memory necessary for the representation of neural activation in velocity space. We propose a sparse coding framework for neural motion activity patterns and suggest a means by which initial activities are detected efficiently. We realize neural mechanisms such as shunting inhibition and feedback modulation in the sparse framework to implement an efficient algorithmic version of our neural model of cortical motion segregation. We demonstrate that the algorithm behaves similarly to the original neural model and is able to extract image motion from real world image sequences. Our investigation transfers a neuroscience model of cortical motion computation to achieve technologically demanding constraints such as real-time performance and hardware implementation. In addition, the proposed biologically inspired algorithm provides a tool for modeling investigations to achieve acceptable simulation time.

  1. 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.

  2. Impact of a Fast Track in the Emergency Department of Martin Army Community Hospital

    DTIC Science & Technology

    2006-07-01

    and a dependent variable a point biseral correlation coefficient can be used. (Polit, 2006). The point biserial correlation coefficient, rpb , ranges...from -1.00 to 1.00 and indicates the strength of the relationship. The formula for rpb is: Fast Track 43 rpb = +Pt r Vb lt’ +df The larger the...2.30, p=0.01 (one-tailed) while showing a weak positive relationship ( rpb =0.01). Compared to the benchmarks determined using the CDC survey data

  3. A steady tracking technology adopted to fast FH/BPSK signal under satellite channel

    NASA Astrophysics Data System (ADS)

    Guo, SuLi; Lou, Zhigang; Wang, XiDuo; Xia, ShuangZhi

    2015-07-01

    In order to survive under the conditions with great jamming and interference, fast frequency hopped signal are employed in satellite communication system. This paper discusses the nonlinear phases induced by the equipment and atmosphere, and their influence on the FFH/BPSK tracking loop. Two methods are developed including compensating phase which is based on channel estimation and compensating Doppler frequency based on velocity normalization. Simulation results for a real circuit with proper parameters shows that the degradation due to the demodulation of frequency-hopped is only a fraction of one dB in an AWGN environment under satellite channel.

  4. 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.

  5. 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.

  6. 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

  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. 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.

  9. 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.

  10. 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

  11. A fast single-pixel laser imager for VR/AR headset tracking

    NASA Astrophysics Data System (ADS)

    Milanović, Veljko; Kasturi, Abhishek; Yang, James; Hu, Frank

    2017-02-01

    In this work we demonstrate a highly flexible laser imaging system for 3D sensing applications such as in tracking of VR/AR headsets, hands and gestures. The system uses a MEMS mirror scan module to transmit low power laser pulses over programmable areas within a field of view and uses a single photodiode to measure the reflected light. User can arbitrarily select the number of pixels to scan over an area and can thus obtain images of target objects at arbitrarily fast rates. The work builds on the previously presented "MEMSEye" laser tracking technology which uses a fast steering MEMS scan module with a modulated laser, and a tuned photosensor to acquire and track a retroreflector-marked object. To track VR/AR headsets, hands and similar objects with multiple markers or no markers at all, a single-point tracking methodology is not sufficient. Cameras could be more appropriate in such multi-point imaging cases but suffer from low frame rates, dependence on ambient lighting, and relatively low resolution when without zooming and panning capability. A hybrid method can address the problem by providing a system with its own light source (laser beam), and with full programmability of the pixel locations and scans such that frame rates of >100 Hz are possible over specific areas of interest. With a modest 1 Mpixel rate of measurement, scanning a sub-region of the field of view with 64 x 64 pixels results in 200Hz update. Multiple such modules can be used to scan and image or track objects with multiple markers and fully obtain their position and attitude in a room with sub-5ms updates. Furthermore the room itself could be imaged and measured with wall markers or in conjunction with a camera for a total 3D scanning solution. Proof of concept demonstrator is presented here with pixel rates of only 30k-50k per second due to limitations of the present prototype electronics, resulting in refresh rates that are significantly lower than possible with the MEMS mirror scan

  12. 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.

  13. 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.

  14. Developed algorithm of maximum power tracking for stand-alone photovoltaic system

    SciTech Connect

    Nafeh, A.E.A.; Fahmy, F.H.; Mahgoub, O.A.; El-Zahab, E.M.A.

    1998-01-01

    The rapid increase in the cost of conventional energy sources leads to the use of nonconventional energy sources. The photovoltaic (PV) is one nonconventional source that is safe, reliable, and environmentally healthy. However, the PV system is expensive and needs a large area to operate. To solve these disadvantages, it is necessary to operate at the maximum power point (MPP) of the array. This article presents a new maximum power tracking algorithm based on the incremental conductance algorithm, which successfully operates even in cases of rapidly changing atmospheric conditions. The developed algorithm depends on the relationship between the load line and the tangent line angles of the I-V characteristic curve. A simulation program was designed to investigate the performance of the developed algorithm using mathematical models for the different system components. The simulation led to a good realization of the algorithm.

  15. 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.

  16. Fast Algorithms for Structural Optimization, Least Squares and Related Computations

    DTIC Science & Technology

    1988-09-01

    three levels of parallelism Plemmons Final Report AFOSR-83-0255 Page 4 such as the Cedar system. This is joint work with A. Sameh and G. H. Golub. (See...Applications and Alg. Design for High speed Computing - Urbana IL, (1987) (with G. H. Golub and A. Sameh ). 18. A conjugate gradient method for equality...Equilibrium Matrices, to be submitted (with R. E. White). 32. Parallel algorithms for numerical linear algebra, in prepatation for the SIAM Review (with K. Gallivan and A. Sameh ).

  17. 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.

  18. Quadrant architecture for fast in-place algorithms

    SciTech Connect

    Besslich, P.W.; Kurowski, J.O.

    1983-10-01

    The architecture proposed is tailored to support Radix-2/sup k/ based in-place processing of pictorial data. The algorithms make use of signal-flow graphs to describe 2-dimensional in-place operations suitable for image processing. They may be executed on a general-purpose computer but may also be supported by a special parallel architecture. Major advantages of the scheme are in-place processing and parallel access to disjoint sections of memory only. A quadtree-like decomposition of the picture prevents blocking and queuing of private and common buses. 9 references.

  19. A Fast Algorithm for the Numerical Evaluation of Conformal Mappings.

    DTIC Science & Technology

    1987-07-01

    YALEU/DCS/RR-459. [10] P. Henrici , Applied and Computational Complez Analysis Vol. 3, John Wiley, New York, 1986. [11] N. Kerzman, E.M. Stein, The Cauchy...CONFORMAL MAPPINGS(U) YALE UNIV NEW HAVEN CT DEPT OF COMPUTER SCIENCE 5 T O’DONNELL ET AL. JUL 87 UNCLASSIFIED V ALEU/DCS/RR-554 N M14-U6--K-31F/12/1...YALE UNIVERSITY DEPARTMENT OF COMPUTER SCIENCE asQ = . V ~ ~ i M.’-~~ ade ~?Vap An algorithm is presented for the construction of conformal maping@ from

  20. 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.

  1. Target-tracking and identity management algorithms for air traffic surveillance

    NASA Astrophysics Data System (ADS)

    Balakrishnan, Hamsa

    The air traffic control system of the United States is responsible for managing traffic in the National Airspace System; safety is a paramount concern. The air traffic surveillance network has the task of collecting and processing information on the positions, velocities and identities of the aircraft in the system, before presenting it to air traffic controllers to use in maintaining an orderly flow of traffic. This dissertation attempts to design techniques that provide controllers with high-fidelity information about the aircraft in their controlled airspace, using the observations of the air traffic surveillance network. We propose algorithms for the efficient tracking of aircraft, as well as for maintaining beliefs of their identities. Such methods would improve the processing of aircraft situation data, particularly in a congested airspace with general aviation. In this thesis, we propose an algorithmic framework for the simultaneous tracking and identity management of multiple maneuvering targets. We design an algorithm that efficiently tracks the positions, velocities, flight modes, and identities of multiple aircraft in cluttered environments. We tackle the challenges of data association, identity management and state estimation of aircraft trajectories by proposing a modification of the Joint Probabilistic Data Association algorithm, an algorithm based on identity-mass flow, and a state estimation algorithm for tracking hybrid systems, respectively. The identity of each aircraft, an essential feature of aircraft situation data, is often not available but needs to be inferred from radar observations, and maintained in terms of probabilities. We present an algorithm to update the probabilistic matrices that represent the belief of aircraft identities, in the presence of intermittent measurements. We demonstrate the performance of the framework using examples drawn from air traffic surveillance. We also consider the problem of identifying stochastic hybrid

  2. Neural-network based autocontouring algorithm for intrafractional lung-tumor tracking using Linac-MR.

    PubMed

    Yun, Jihyun; Yip, Eugene; Gabos, Zsolt; Wachowicz, Keith; Rathee, Satyapal; Fallone, B G

    2015-05-01

    To develop a neural-network based autocontouring algorithm for intrafractional lung-tumor tracking using Linac-MR and evaluate its performance with phantom and in-vivo MR images. An autocontouring algorithm was developed to determine both the shape and position of a lung tumor from each intrafractional MR image. A pulse-coupled neural network was implemented in the algorithm for contrast improvement of the tumor region. Prior to treatment, to initiate the algorithm, an expert user needs to contour the tumor and its maximum anticipated range of motion in pretreatment MR images. During treatment, however, the algorithm processes each intrafractional MR image and automatically generates a tumor contour without further user input. The algorithm is designed to produce a tumor contour that is the most similar to the expert's manual one. To evaluate the autocontouring algorithm in the author's Linac-MR environment which utilizes a 0.5 T MRI, a motion phantom and four lung cancer patients were imaged with 3 T MRI during normal breathing, and the image noise was degraded to reflect the image noise at 0.5 T. Each of the pseudo-0.5 T images was autocontoured using the author's algorithm. In each test image, the Dice similarity index (DSI) and Hausdorff distance (HD) between the expert's manual contour and the algorithm generated contour were calculated, and their centroid positions were compared (Δd centroid). The algorithm successfully contoured the shape of a moving tumor from dynamic MR images acquired every 275 ms. From the phantom study, mean DSI of 0.95-0.96, mean HD of 2.61-2.82 mm, and mean Δd centroid of 0.68-0.93 mm were achieved. From the in-vivo study, the author's algorithm achieved mean DSI of 0.87-0.92, mean HD of 3.12-4.35 mm, as well as Δd centroid of 1.03-1.35 mm. Autocontouring speed was less than 20 ms for each image. The authors have developed and evaluated a lung tumor autocontouring algorithm for intrafractional tumor tracking using Linac-MR. The

  3. Identification of fast-steering mirror based on chicken swarm optimization algorithm

    NASA Astrophysics Data System (ADS)

    Ren, Wei; Deng, Chao; Zhang, Chao; Mao, Yao

    2017-06-01

    According to the transfer function identification method of fast steering mirror exists problems which estimate the initial value is complicated in the process of using, put forward using chicken swarm algorithm to simplify the identification operation, reducing the workload of identification. chicken swarm algorithm is a meta heuristic intelligent population algorithm, which shows global convergence is efficient in the identification experiment, and the convergence speed is fast. The convergence precision is also high. Especially there are many parameters are needed to identificate in the transfer function without considering the parameters estimation problem. Therefore, compared with the traditional identification methods, the proposed approach is more convenient, and greatly achieves the intelligent design of fast steering mirror control system in enginerring application, shorten time of controller designed.

  4. Effectiveness of fast-track rehabilitation vs conventional care in laparoscopic colorectal resection for elderly patients: a randomized trial.

    PubMed

    Wang, Q; Suo, J; Jiang, J; Wang, C; Zhao, Y-Q; Cao, X

    2012-08-01

    The aim of the study was to evaluate the efficacy and safety of fast-track rehabilitation in elderly patients over 65 years of age, following laparoscopic surgery to remove colorectal cancer. A total of 78 elderly patients with colorectal cancer who underwent laparoscopic colorectal resection were randomly assigned to receive either the fast-track care programme (n = 40) or the conventional perioperative care protocol (control group, n = 38). Medical personnel conducting the study were blinded to patients' clinical outcomes prior to statistical analysis. The fast-track protocol included no preoperative mechanical bowel irrigation, immediate oral alimentation and earlier postoperative ambulation exercise. The length of postoperative hospital stay, the length of time to regain bowel function and the rate of postoperative complications were compared between the two groups. The length of time to regain bowel function, including the passage of flatus[31 (26-40) h vs 38 (32-51) h, P = 0.001], to the first bowel movement [55 (48-63) h vs 64 (48-71) h, P = 0.009] and to start a liquid diet (12 [11-16] h vs 47 [35-50] h, P = 0.000) were significantly shorter in patients receiving the fast-track care protocol compared with those receiving the conventional care protocol. A shorter duration of postoperative hospital stay was recorded in patients receiving the fast-track program than in those receiving conventional care (P = 0.0001). A reduced percentage of patients who developed general complications was also observed in the fast-track group (5.0%vs 21.1%, P = 0.045). This randomized controlled trial has shown that in the elderly undergoing laparoscopic colorectal surgery, the fast-track recovery programme resulted in a more rapid postoperative recovery, earlier discharge from hospital and fewer general complications compared with a conventional postoperative protocol. © 2011 The Authors. Colorectal Disease © 2011 The Association of Coloproctology of Great Britain and

  5. "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.

  6. 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

  7. 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.

  8. 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.

  9. An improvement of the fast uncovering community algorithm

    NASA Astrophysics Data System (ADS)

    Wang, Li; Wang, Jiang; Shen, Hua-Wei; Cheng, Xue-Qi

    2013-10-01

    Community detection methods have been used in computer, sociology, physics, biology, and brain information science areas. Many methods are based on the optimization of modularity. The algorithm proposed by Blondel et al. (Blondel V D, Guillaume J L, Lambiotte R and Lefebvre E 2008 J. Stat. Mech. 10 10008) is one of the most widely used methods because of its good performance, especially in the big data era. In this paper we make some improvements to this algorithm in correctness and performance. By tests we see that different node orders bring different performances and different community structures. We find some node swings in different communities that influence the performance. So we design some strategies on the sweeping order of node to reduce the computing cost made by repetition swing. We introduce a new concept of overlapping degree (OV) that shows the strength of connection between nodes. Three improvement strategies are proposed that are based on constant OV, adaptive OV, and adaptive weighted OV, respectively. Experiments on synthetic datasets and real datasets are made, showing that our improved strategies can improve the performance and correctness.

  10. 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.

  11. 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.

  12. Comparison of different tracking algorithms analysing subantarctic cyclones: A contribution to the IMILAST programme

    NASA Astrophysics Data System (ADS)

    Grieger, Jens; Leckebusch, Gregor C.; Raible, Christoph C.; Rudeva, Irina; Simmonds, Ian

    2015-04-01

    Cyclones are a dominant feature of the mid- and high-latitude atmospheric circulation, however their definition is not straightforward as their characteristics are complex. Thus, a number of studies present different objective cyclone detection and tracking algorithms focusing on different aspects of what is thought to be the main characteristic of a cyclone. For example, studies use either the rotational character of cyclones by using the vorticity as main field to identify cyclones or the mass character by using the pressure field. In this study, 14 different objective identification and tracking algorithms are compared by analyzing subantarctic cyclones. This region is of especial interest because it hosts the greatest frequencies of cyclogenesis and cyclone occurrence across the whole Southern Hemisphere. The character of cyclones there are strongly influenced by the intense baroclinicity and the presence of the Antarctic massif. The study is part of the Intercomparison of Mid Latitude STorm diagnostics (IMILAST) project. As a common basis ERA-Interim reanalysis data between 1979-2008 is used. This contribution investigates the output of the different tracking algorithms for the representation of extra-tropical cyclones around Antarctica, and all cyclone tracks south of 60° S are selected. We focus on three sectors around Antarctica, namely East Antarctica, Amundsen-Bellingshausen Seas, and Weddell Sea, for a differentiated comparison of the different tracking methodologies. A track-to-track analysis allows the evaluation of differences and similarities of the methodologies for the representation of subantarctic cyclones. As known from similar studies for the entire Southern Hemisphere, absolute numbers of identified cyclone tracks differ significantly. This is also the case for all sectors around Antarctica. Differences are even more pronounced in austral winter (JJA) due to the different treatment of cyclone intensities by the numerous tracking methods

  13. Towards designing an optical-flow based colonoscopy tracking algorithm: a comparative study

    NASA Astrophysics Data System (ADS)

    Liu, Jianfei; Subramanian, Kalpathi R.; Yoo, Terry S.

    2013-03-01

    Automatic co-alignment of optical and virtual colonoscopy images can supplement traditional endoscopic procedures, by providing more complete information of clinical value to the gastroenterologist. In this work, we present a comparative analysis of our optical flow based technique for colonoscopy tracking, in relation to current state of the art methods, in terms of tracking accuracy, system stability, and computational efficiency. Our optical-flow based colonoscopy tracking algorithm starts with computing multi-scale dense and sparse optical flow fields to measure image displacements. Camera motion parameters are then determined from optical flow fields by employing a Focus of Expansion (FOE) constrained egomotion estimation scheme. We analyze the design choices involved in the three major components of our algorithm: dense optical flow, sparse optical flow, and egomotion estimation. Brox's optical flow method,1 due to its high accuracy, was used to compare and evaluate our multi-scale dense optical flow scheme. SIFT6 and Harris-affine features7 were used to assess the accuracy of the multi-scale sparse optical flow, because of their wide use in tracking applications; the FOE-constrained egomotion estimation was compared with collinear,2 image deformation10 and image derivative4 based egomotion estimation methods, to understand the stability of our tracking system. Two virtual colonoscopy (VC) image sequences were used in the study, since the exact camera parameters(for each frame) were known; dense optical flow results indicated that Brox's method was superior to multi-scale dense optical flow in estimating camera rotational velocities, but the final tracking errors were comparable, viz., 6mm vs. 8mm after the VC camera traveled 110mm. Our approach was computationally more efficient, averaging 7.2 sec. vs. 38 sec. per frame. SIFT and Harris affine features resulted in tracking errors of up to 70mm, while our sparse optical flow error was 6mm. The comparison

  14. 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

  15. On fast iterative mapping algorithms for stripe based coarse-grained reconfigurable architectures

    NASA Astrophysics Data System (ADS)

    Mehta, Gayatri; Patel, Krunalkumar; Pollard, Nancy S.

    2015-01-01

    Reconfigurable devices have potential for great flexibility/efficiency, but mapping algorithms onto these architectures is a long-standing challenge. This paper addresses this challenge for stripe based coarse-grained reconfigurable architectures (CGRAs) by drawing on insights from graph drawing. We adapt fast, iterative algorithms from hierarchical graph drawing to the problem of mapping to stripe based architectures. We find that global sifting is 98 times as fast as simulated annealing and produces very compact designs with 17% less area on average, at a cost of 5% greater wire length. Interleaving iterations of Sugiyama and global sifting is 40 times as fast as simulated annealing and achieves somewhat more compact designs with 1.8% less area on average, at a cost of only 1% greater wire length. These solutions can enable fast design space exploration, rapid performance testing, and flexible programming of CGRAs "in the field."

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

    PubMed

    Winey, Brian; Sharp, Greg; Bussière, Marc

    2011-01-01

    To design a fast Winston Lutz (fWL) algorithm for accurate analysis of radiation isocenter from images without edge detection or center of mass calculations. 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 (0.05 mm/px, film) and low resolution (0.78 mm/px, EPID) image sets. 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. 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.

  17. 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.

  18. Fast-track program in laparoscopic liver surgery: Theory or fact?

    PubMed

    Sánchez-Pérez, Belinda; Aranda-Narváez, José Manuel; Suárez-Muñoz, Miguel Angel; Eladel-Delfresno, Moises; Fernández-Aguilar, José Luis; Pérez-Daga, Jose Antonio; Pulido-Roa, Ysabel; Santoyo-Santoyo, Julio

    2012-11-27

    To analyze our results after the introduction of a fast-track (FT) program after laparoscopic liver surgery in our Hepatobiliarypancreatic Unit. All patients (43) undergoing laparoscopic liver surgery between March 2004 and March 2010 were included and divided into two consecutive groups: Control group (CG) from March 2004 until December 2006 with traditional perioperative cares (17 patients) and fast-track group (FTG) from January 2007 until March 2010 with FT program cares (26 patients). Primary endpoint was the influence of the program on the postoperative stay, the amount of re-admissions, morbidity and mortality. Secondarily we considered duration of surgery, use of drains, conversion to open surgery, intensive cares needs and transfusion. Both groups were homogeneous in age and sex. No differences in technique, time of surgery or conversion to open surgery were found, but more malignant diseases were operated in the FTG, and then transfusions were higher in FTG. Readmissions and morbidity were similar in both groups, without mortality. Postoperative stay was similar, with a median of 3 for CG vs 2.5 for FTG. However, the 80.8% of patients from FTG left the hospital within the first 3 d after surgery (58.8% for CG). The introduction of a FT program after laparoscopic liver surgery improves the recovery of patients without increasing complications or re-admissions, which leads to a reduction of the stay and costs.

  19. A Fast Track approach to deal with the temporal dimension of crop water footprint

    NASA Astrophysics Data System (ADS)

    Tuninetti, Marta; Tamea, Stefania; Laio, Francesco; Ridolfi, Luca

    2017-07-01

    Population growth, socio-economic development and climate changes are placing increasing pressure on water resources. Crop water footprint is a key indicator in the quantification of such pressure. It is determined by crop evapotranspiration and crop yield, which can be highly variable in space and time. While the spatial variability of crop water footprint has been the objective of several investigations, the temporal variability remains poorly studied. In particular, some studies approached this issue by associating the time variability of crop water footprint only to yield changes, while considering evapotranspiration patterns as marginal. Validation of this Fast Track approach has yet to be provided. In this Letter we demonstrate its feasibility through a comprehensive validation, an assessment of its uncertainty, and an example of application. Our results show that the water footprint changes are mainly driven by yield trends, while evapotranspiration plays a minor role. The error due to considering constant evapotranspiration is three times smaller than the uncertainty of the model used to compute the crop water footprint. These results confirm the suitability of the Fast Track approach and enable a simple, yet appropriate, evaluation of time-varying crop water footprint.

  20. 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

  1. 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.

  2. 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.

  3. 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

  4. 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.

  5. 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

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. Measuring the velocity of fluorescently labelled red blood cells with a keyhole tracking algorithm.

    PubMed

    Reyes-Aldasoro, C C; Akerman, S; Tozer, G M

    2008-01-01

    In this paper we propose a tracking algorithm to measure the velocity of fluorescently labelled red blood cells travelling through microvessels of tumours, growing in dorsal skin flap window chambers, implanted on mice. Preprocessing removed noise and artefacts from the images and then segmented cells from background. The tracking algorithm is based on a 'keyhole' model that describes the probable movement of a segmented cell between contiguous frames of a video sequence. When a history of cell movement exists, past, present and a predicted landing position of the cells will define two regions of probability that resemble the shape of a keyhole. This keyhole model was used to determine if cells in contiguous frames should be linked to form tracks and also as a postprocessing tool to join split tracks and discard links that could have been formed due to noise or uncertainty. When there was no history, a circular region around the centroid of the parent cell was used as a region of probability. Outliers were removed based on the distribution of the average velocities of the tracks. Since the position and time of each cell is recorded, a wealth of statistical measures can be obtained from the tracks. The algorithm was tested on two sets of experiments. First, the vasculatures of eight tumours with different geometries were analyzed; average velocities ranged from 86 to 372 microm s(-1), with minimum and maximum track velocities 7 and 1212 microm s(-1), respectively. Second, a longitudinal study of velocities was performed after administering a vascular disrupting agent to two tumours and the time behaviour was analyzed over 24 h. In one of the tumours there is a complete shutdown of the vasculature whereas in the other there is a clear decrease of velocity at 30 min, with subsequent recovery by 6 h. The tracking algorithm enabled the simultaneous measurement of red blood cell velocity in multiple vessels within an intravital video sequence, enabling analysis of

  13. 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 +

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

    SciTech Connect

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

    2014-12-21

    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.

  15. 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.

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

    PubMed Central

    Seitaridou, Effrosyni

    2014-01-01

    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.141, 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. PMID:25527927

  17. 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

  18. 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.

  19. Fast track surgery, a strategy to improve operational efficiency in a high-complexity hospital in Latin America.

    PubMed

    Betancur, Juan David Angel; Montaño, Liliana Marcela Betancur; Jaramillo, André Felipe Espinosa; Delgado, Carlos Enrique Yepes

    2015-01-01

    Fast Track surgery is designed to optimize time in low-complexity procedures, thus improving efficiency in care provision, and preserving patient safety. Before and after intervention study in a surgical setting, with failure mode and effects analysis, identification and prioritization of improvement opportunities, process measurement before the intervention, improvement implementation, practical application, process measurement after the intervention, and surgical time comparisons. With the Fast Track program, 19% of the operating room capacity available was freed per day; before surgical FastTrack implementation, 50% of the procedures started 23 minutes behind schedule. After the Fast Track program was implemented, procedures start 5 minutes ahead of schedule. Anesthesia induction time was reduced by 50%, and skin-to-skin surgical time dropped by 28%. The number of surgical procedures performed in the day increased by 33-50%. There were noincidents or adverse events. Fast Track surgery is a useful strategy for improving operating room efficiency and reducing surgical time. Procedures start on time, with increased timely care, patient and practitioner satisfaction, and lower service costs.

  20. 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.