Large scale tracking algorithms
Energy Technology Data Exchange (ETDEWEB)
Hansen, Ross L. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Love, Joshua Alan [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Melgaard, David Kennett [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Karelitz, David B. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Pitts, Todd Alan [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Zollweg, Joshua David [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Anderson, Dylan Z. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Nandy, Prabal [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Whitlow, Gary L. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Bender, Daniel A. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Byrne, Raymond Harry [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)
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.
Large scale tracking algorithms.
Energy Technology Data Exchange (ETDEWEB)
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.
Institute of Scientific and Technical Information of China (English)
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-Sin; LI Fei; LI Hai-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
2009-01-01
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.
Institute of Scientific and Technical Information of China (English)
无
2008-01-01
The search for patterns or motifs in data represents a problem area of key interest to finance and economic researchers. In this paper, we introduce the motif tracking algorithm (MTA), a novel immune inspired (IS) pattern identification tool that is able to identify unknown motifs of a non specified length which repeat within time series data. The power of the algorithm comes from the fact that it uses a small number of parameters with minimal assumptions regarding the data being examined or the underlying motifs. Our interest lies in applying the algorithm to financial time series data to identify unknown patterns that exist. The algorithm is tested using three separate data sets. Particular suitability to financial data is shown by applying it to oil price data. In all cases, the algorithm identifies the presence of a motif population in a fast and efficient manner due to the utilization of an intuitive symbolic representation.The resulting population of motifs is shown to have considerable potential value for other applications such as forecasting and algorithm seeding.
Wilson, William; Aickelin, Uwe; 10.1007/s11633.008.0032.0
2010-01-01
The search for patterns or motifs in data represents a problem area of key interest to finance and economic researchers. In this paper we introduce the Motif Tracking Algorithm, a novel immune inspired pattern identification tool that is able to identify unknown motifs of a non specified length which repeat within time series data. The power of the algorithm comes from the fact that it uses a small number of parameters with minimal assumptions regarding the data being examined or the underlying motifs. Our interest lies in applying the algorithm to financial time series data to identify unknown patterns that exist. The algorithm is tested using three separate data sets. Particular suitability to financial data is shown by applying it to oil price data. In all cases the algorithm identifies the presence of a motif population in a fast and efficient manner due to the utilisation of an intuitive symbolic representation. The resulting population of motifs is shown to have considerable potential value for other ap...
Tracking algorithms for multiagent systems.
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.
SIFT based algorithm for point feature tracking
Directory of Open Access Journals (Sweden)
Adrian BURLACU
2007-12-01
Full Text Available In this paper a tracking algorithm for SIFT features in image sequences is developed. For each point feature extracted using SIFT algorithm a descriptor is computed using information from its neighborhood. Using an algorithm based on minimizing the distance between two descriptors tracking point features throughout image sequences is engaged. Experimental results, obtained from image sequences that capture scaling of different geometrical type object, reveal the performances of the tracking algorithm.
Fixed Scan Area Tracking with Track Splitting Filtering Algorithm
DEFF Research Database (Denmark)
Hussain, Dil Muhammad Akbar; Ahmed, Zaki
2006-01-01
to develop procedures that would enable a more general performance assessment. Therefore, a non-deterministic scenario is adopted, which basically provide a more appropriate approach for the evaluation of a tracking system based on track splitting filter algorithm. The objects are generated within a fixed...
A Volume Clearing Algorithm for Muon Tomography
Mitra, D; Hohlmann, M
2014-01-01
The primary objective is to enhance muon-tomographic image reconstruction capability by providing distinctive information in terms of deciding on the properties of regions or voxels within a probed volume "V" during any point of scanning: threat type, non-threat type, or not-sufficient data. An algorithm (MTclear) is being developed to ray-trace muon tracks and count how many straight tracks are passing through a voxel. If a voxel "v" has sufficient number of straight tracks (t), then "v" is a non-threat type voxel, unless there are sufficient number of scattering points (p) in "v" that will make it a threat-type voxel. The algorithm also keeps track of voxels for which not enough information is known: where p and v both fall below their respective threshold parameters. We present preliminary results showing how the algorithm works on data collected with a Muon Tomography station based on gas electron multipliers operated by our group. The MTclear algorithm provides more comprehensive information to a human o...
An FPGA helix tracking algorithm for PANDA
Energy Technology Data Exchange (ETDEWEB)
Muenchow, David; Galuska, Martin; Gessler, Thomas; Kuehn, Wolfgang; Lange, Jens Soeren; Liang, Yutie; Liu, Ming; Spruck, Bjoern [Justus Liebig University Giessen (Germany); Spataro, Stefano [University of Torino (Italy)
2010-07-01
An online track finder for the PANDA experiment at the future FAIR facility was developed and tested. The central Panda tracking detectors for charged particles will consist of a silicon based micro vertex detector (MVD, 5-7 hits/track) and possibly of a straw tube tracker (STT, 15 double layers of straws). Due to the solenoidal magnetic field, tracks of charged particles can be parametrized by a helix (if neglecting energy loss). The algorithm works in several steps. Perpendicular to the beam direction the projection of the tracks is equivalent to a circle. Thus, first a conformal transformation will be used to convert the circles to straight lines. Second, a Hough transform is used to find the straight lines by a peak finding algorithm. Along the beam direction, a different Hough transformation is used. As the algorithm was developed for an FPGA, it uses lookup tables. Possible FPGA implementation is discussed.
FPGA helix tracking algorithm for PANDA
Energy Technology Data Exchange (ETDEWEB)
Liang, Yutie; Galuska, Martin; Gessler, Thomas; Kuehn, Wolfgang; Lange, Jens Soeren; Muenchow, David; Spruck, Bjoern [II. Physikalisches Institut, Giessen University (Germany); Ye, Hua [Institute of High Energy Physics, Beijing (China); Collaboration: PANDA-Collaboration
2015-07-01
The PANDA detector is a general-purpose detector for physics with high luminosity cooled antiproton beams, planed to operate at the FAIR facility in Darmstadt, Germany. The central detector includes a silicon Micro Vertex Detector (MVD) and a Straw Tube Tracker (STT). Without any hardware trigger, large amounts of raw data are streaming into the data acquisition system. The data reduction task is performed in the online system by reconstruction algorithms programmed on FPGAs (Field Programmable Gate Arrays) as first level and on a farm of GPUs or PCs as a second level. One important part in the system is the online track reconstruction. In this presentation, an online tracking algorithm for helix tracking reconstruction in the solenoidal field is shown. The tracking algorithm is composed by two parts, a road finding module followed by an iterative helix parameter calculation module. A performance study using C++ and the status of the VHDL implementation are presented.
DynaMax+ ground-tracking algorithm
Smock, Brandon; Gader, Paul; Wilson, Joseph
2011-06-01
In this paper, we propose a new method for performing ground-tracking using ground-penetrating radar (GPR). Ground-tracking involves identifying the air-ground interface, which is usually the dominant feature in a radar image but frequently is obscured or mimicked by other nearby elements. It is an important problem in landmine detection using vehicle-mounted systems because antenna motion, caused by bumpy ground, can introduce distortions in downtrack radar images, which ground-tracking makes it possible to correct. Because landmine detection is performed in real-time, any algorithm for ground-tracking must be able to run quickly, prior to other, more computationally expensive algorithms for detection. In this investigation, we first describe an efficient algorithm, based on dynamic programming, that can be used in real-time for tracking the ground. We then demonstrate its accuracy through a quantitative comparison with other proposed ground-tracking methods, and a qualitative comparison showing that its ground-tracking is consistent with human observations in challenging terrain.
Target-tracking algorithm for omnidirectional vision
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.
UWB Tracking System Design with TDOA Algorithm
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).
Institute of Scientific and Technical Information of China (English)
YANGGuo-Sheng; WENCheng-Lin; TANMin
2004-01-01
A new multisensor distributed track fusion algorithm is put forward based on combiningthe feedback integration with the strong tracking Kalman filter. Firstly, an effective tracking gateis constructed by taking the intersection of the tracking gates formed before and after feedback.Secondly, on the basis of the constructed effective tracking gate, probabilistic data association andstrong tracking Kalman filter are combined to form the new multisensor distributed track fusionalgorithm. At last, simulation is performed on the original algorithm and the algorithm presented.
FPGA helix tracking algorithm for PANDA
Energy Technology Data Exchange (ETDEWEB)
Liang, Yutie; Galuska, Martin; Gessler, Thomas; Hu, Jifeng; Kuehn, Wolfgang; Lange, Jens Soeren; Muenchow, David; Spruck, Bjoern [II. Physikalisches, Giessen University (Germany); Ye, Hua [II. Physikalisches, Giessen University (Germany); Institute of High Energy Physics, Beijing (China); Collaboration: PANDA-Collaboration
2014-07-01
The PANDA detector is a general-purpose detector for physics with high luminosity cooled antiproton beams, planed to operate at the FAIR facility in Darmstadt, Germany. The central detector includes a silicon Micro Vertex Detector (MVD) and a Straw Tube Tracker (STT). Without any hardware trigger, large amounts of raw data are streaming into the data acquisition system. The data reduction task is performed in the online system by reconstruction algorithms programmed in VHDL (Very High Speed Integrated Circuit Hardware Description Language) on FPGAs (Field Programmable Gate Arrays) as first level and on a farm of GPUs or PCs as a second level. One important part in the system is the online track reconstruction. In this presentation, an online tracking finding algorithm for helix track reconstruction in the solenoidal field is shown. A performance study using C++ and the status of the VHDL implementation are presented.
Tracking algorithms for the active target MAYA
Roger, T; Demonchy, C E; Mittig, W; Savajols, H; Tanihata, I
2010-01-01
The MAYA detector is a Time-Charge Projection Chamber based on the concept of active target. These type of devices use a part of the detection system, the filling gas in this case, in the role of reaction target. The MAYA detector performs three-dimensional tracking, in order to determine physical observables of the reactions occurring inside the detector. The reconstruction algorithms of the tracking use the information from a two-dimensional projection on the segmented cathode, and, in general, they need to be adapted for the different experimental settings of the detector. This work presents some of the most relevant solutions developed for the MAYA detector.
A Track Matching Algorithm for the LHCb upgrade
Esen, Sevda
2016-01-01
This document presents a description and performance estimate of the Track Matching algorithm for the LHCb Upgrade. The algorithm combines tracks reconstructed in the Vertex Locator and in the three stations of the Scintillating Fibre Tracker.
CONTAMINATED SOIL VOLUME ESTIMATE TRACKING METHODOLOGY
Energy Technology Data Exchange (ETDEWEB)
Durham, L.A.; Johnson, R.L.; Rieman, C.; Kenna, T.; Pilon, R.
2003-02-27
The U.S. Army Corps of Engineers (USACE) is conducting a cleanup of radiologically contaminated properties under the Formerly Utilized Sites Remedial Action Program (FUSRAP). The largest cost element for most of the FUSRAP sites is the transportation and disposal of contaminated soil. Project managers and engineers need an estimate of the volume of contaminated soil to determine project costs and schedule. Once excavation activities begin and additional remedial action data are collected, the actual quantity of contaminated soil often deviates from the original estimate, resulting in cost and schedule impacts to the project. The project costs and schedule need to be frequently updated by tracking the actual quantities of excavated soil and contaminated soil remaining during the life of a remedial action project. A soil volume estimate tracking methodology was developed to provide a mechanism for project managers and engineers to create better project controls of costs and schedule. For the FUSRAP Linde site, an estimate of the initial volume of in situ soil above the specified cleanup guidelines was calculated on the basis of discrete soil sample data and other relevant data using indicator geostatistical techniques combined with Bayesian analysis. During the remedial action, updated volume estimates of remaining in situ soils requiring excavation were calculated on a periodic basis. In addition to taking into account the volume of soil that had been excavated, the updated volume estimates incorporated both new gamma walkover surveys and discrete sample data collected as part of the remedial action. A civil survey company provided periodic estimates of actual in situ excavated soil volumes. By using the results from the civil survey of actual in situ volumes excavated and the updated estimate of the remaining volume of contaminated soil requiring excavation, the USACE Buffalo District was able to forecast and update project costs and schedule. The soil volume
Track segment association algorithm based on statistical binary thresholds
Directory of Open Access Journals (Sweden)
Qi Lin
2015-05-01
Full Text Available The classical Track Segment Association (TSA algorithm suffers from low accuracy and is impractical to use in concentrated targets, branching, and cross-tracking environment. Thus, a new statistical binary track segment association algorithm is proposed. The new algorithm is more appropriate as it increases the sample size for the χ2 distribution threshold detection. Simulation results show that in air cross tracking and for ballistic targets, the global correct association rate and the average correct association rate of the proposed algorithm are remarkably improved, which proves the good performance of the proposed algorithm.
Cooperative distributed target tracking algorithm in mobile wireless sensor networks
Institute of Scientific and Technical Information of China (English)
无
2011-01-01
The paper proposes a cooperative distributed target tracking algorithm in mobile wireless sensor networks.There are two main components in the algorithm:distributed sensor-target assignment and sensor motion control.In the key idea of the sensor-target assignment,sensors are considered as autonomous agents and the defined objective function of each sensor concentrates on two fundamental factors:the tracking accuracy and the tracking cost.Compared with the centralized algorithm and the noncooperative distrib...
FPGA Online Tracking Algorithm for the PANDA Straw Tube Tracker
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.
FPGA Online Tracking Algorithm for the PANDA Straw Tube Tracker
Liang, Yutie; Galuska, Martin J; Gessler, Thomas; Kühn, Wolfgang; Lange, Jens Sören; Wagner, Milan N; Liu, Zhen'an; Zhao, Jingzhou
2016-01-01
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.
Models and Algorithms for Tracking Target with Coordinated Turn Motion
Directory of Open Access Journals (Sweden)
Xianghui Yuan
2014-01-01
Full Text Available Tracking target with coordinated turn (CT motion is highly dependent on the models and algorithms. First, the widely used models are compared in this paper—coordinated turn (CT model with known turn rate, augmented coordinated turn (ACT model with Cartesian velocity, ACT model with polar velocity, CT model using a kinematic constraint, and maneuver centered circular motion model. Then, in the single model tracking framework, the tracking algorithms for the last four models are compared and the suggestions on the choice of models for different practical target tracking problems are given. Finally, in the multiple models (MM framework, the algorithm based on expectation maximization (EM algorithm is derived, including both the batch form and the recursive form. Compared with the widely used interacting multiple model (IMM algorithm, the EM algorithm shows its effectiveness.
Institute of Scientific and Technical Information of China (English)
Liuhong Zhu; Gang Guo
2012-01-01
This study tested an improved fiber tracking algorithm, which was based on fiber assignment using a continuous tracking algorithm and a two-tensor model. Different models and tracking decisions were used by judging the type of estimation of each voxel. This method should solve the cross-track problem. This study included eight healthy subjects, two axonal injury patients and seven demyelinating disease patients. This new algorithm clearly exhibited a difference in nerve fiber direction between axonal injury and demyelinating disease patients and healthy control subjects. Compared with fiber assignment with a continuous tracking algorithm, our novel method can track more and longer nerve fibers, and also can solve the fiber crossing problem.
An OpenCL tracking algorithm for LHCb
Gutierrez Milla, Albert
2013-01-01
Tracking is currently performed at LHCb using a sequential algorithm parallelized by event in a cluster of about 1.500 computers. To update this system a parallel version for GPUs has been implemented. The present work presents an OpenCL implementation of a tracking algorithm for the LHCb trigger system. The algorithm is based on a previous work by David Rohr in the ALICE detector.
AN IMPROVED SUBSPACE TRACKING ALGORITHM FOR BLIND ADAPTIVE MULTIUSER DETECTION
Institute of Scientific and Technical Information of China (English)
Xu Changqing; Wang Hongyang; Song Wentao
2004-01-01
As the Projection Approximation Subspace Tracking with deflation(PASTd) algorithm is sensitive to impulsive noise, an improved subspace tracking algorithm is proposed and applied to blind adaptive multi-user detection. Simulation results show that the improved PASTd algorithm not only remains the properties of the conventional PASTdalgorithm, but also has good Bit Error Rate(BER) performance in impulsive noise environment, thus it can effectively improve the system performance.
Improved motion information-based infrared dim target tracking algorithms
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.
Modeling and performance analysis of GPS vector tracking algorithms
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
A benchmark for comparison of cell tracking algorithms
M. Maška (Martin); V. Ulman (Vladimír); K. Svoboda; P. Matula (Pavel); P. Matula (Petr); C. Ederra (Cristina); A. Urbiola (Ainhoa); T. España (Tomás); R. Venkatesan (Rajkumar); D.M.W. Balak (Deepak); P. Karas (Pavel); T. Bolcková (Tereza); M. Štreitová (Markéta); C. Carthel (Craig); S. Coraluppi (Stefano); N. Harder (Nathalie); K. Rohr (Karl); K.E.G. Magnusson (Klas E.); J. Jaldén (Joakim); H.M. Blau (Helen); O.M. Dzyubachyk (Oleh); P. Křížek (Pavel); G.M. Hagen (Guy); D. Pastor-Escuredo (David); D. Jimenez-Carretero (Daniel); M.J. Ledesma-Carbayo (Maria); A. Muñoz-Barrutia (Arrate); E. Meijering (Erik); M. Kozubek (Michal); C. Ortiz-De-Solorzano (Carlos)
2014-01-01
textabstractMotivation: Automatic tracking of cells in multidimensional time-lapse fluorescence microscopy is an important task in many biomedical applications. A novel framework for objective evaluation of cell tracking algorithms has been established under the auspices of the IEEE International Sy
A benchmark for comparison of cell tracking algorithms
M. Maška (Martin); V. Ulman (Vladimír); K. Svoboda; P. Matula (Pavel); P. Matula (Petr); C. Ederra (Cristina); A. Urbiola (Ainhoa); T. España (Tomás); R. Venkatesan (Rajkumar); D.M.W. Balak (Deepak); P. Karas (Pavel); T. Bolcková (Tereza); M. Štreitová (Markéta); C. Carthel (Craig); S. Coraluppi (Stefano); N. Harder (Nathalie); K. Rohr (Karl); K.E.G. Magnusson (Klas E.); J. Jaldén (Joakim); H.M. Blau (Helen); O.M. Dzyubachyk (Oleh); P. Křížek (Pavel); G.M. Hagen (Guy); D. Pastor-Escuredo (David); D. Jimenez-Carretero (Daniel); M.J. Ledesma-Carbayo (Maria); A. Muñoz-Barrutia (Arrate); E. Meijering (Erik); M. Kozubek (Michal); C. Ortiz-De-Solorzano (Carlos)
2014-01-01
textabstractMotivation: Automatic tracking of cells in multidimensional time-lapse fluorescence microscopy is an important task in many biomedical applications. A novel framework for objective evaluation of cell tracking algorithms has been established under the auspices of the IEEE International
AN ADAPTIVE MOVING TARGET TRACKING ALGORITHM FOR SMART ANTENNA SYSTEMS
Institute of Scientific and Technical Information of China (English)
无
2008-01-01
In wireless communication environment, the time-varying channel and angular spreads caused by multipath fading and the mobility of Mobile Stations (MS) degrade the performance of the conventional Direction-Of-Arrival (DOA) tracking algorithms. On the other hand, although the DOA estimation methods based on the Maximum Likelihood (ML) principle have higher resolution than the beamforming and the subspace based methods, prohibitively heavy computation limits their practical applications. This letter first proposes a new suboptimal DOA estimation algorithm that combines the advantages of the lower complexity of subspace algorithm and the high accuracy of ML based algorithms, and then proposes a Kalman filtering based tracking algorithm to model the dynamic property of directional changes for mobile terminals in such a way that the association between the estimates made at different time points is maintained. At each stage during tracking process, the current suboptimal estimates of DOA are treated as measurements, predicted and updated via a Kalman state equation, hence adaptive tracking of moving MS can be carried out without the need to perform unduly heavy computations. Computer simulation results show that this proposed algorithm has better performance of DOA estimation and tracking of MS than the conventional ML or subspace based algorithms in terms of accuracy and robustness.
Improved hand tracking algorithm in video sequences for intelligent rehabilitation
Institute of Scientific and Technical Information of China (English)
LI Ling; LUO Yuan; ZHANG Yi; ZHANG Bai-sheng
2009-01-01
Intelligent rehabilitation system is an active research topic. It is motivated by the increased number of limb disabled patients. Human motion tracking is the key technology of intelligent rehabilitation system, because the movement of limb disabled patients needs to be localized and learned so that any undesired motion behavior can be corrected in order to reach an expectation. This paper introduces a real-time tracking system of human hand motion, specifically intent to be used for home rehabilitation. Vision sensor (camera) is employed in this system to track the hand movement, and the improved Camshift algorithm and Kalman filter are used to implement dynamic hand tracking in the video. CAMSHIFT algorithm is able to track any kind of target colors by building a histogram distribution of the H channel in HSV color space from the region of interests selected by users at the initial stage. Kalman filter is able to predict hand location in one image frame based on its location data detected in the previous frame. The experimental results show that this system can track 2D hand motion and has acceptable accuracy by using the two algorithms properly. The new algorithm proposed in this paper can not only deal with the skin color interference problems, but also deal well with the track of complex background.
Multiple object tracking using the shortest path faster association algorithm.
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.
Multiple Object Tracking Using the Shortest Path Faster Association Algorithm
Directory of Open Access Journals (Sweden)
Zhenghao Xi
2014-01-01
Full Text Available 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.
Novel automatic eye detection and tracking algorithm
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.
Taylor Series-based Tracking Algorithm for Through-Wall Tracking of a Moving Person
Directory of Open Access Journals (Sweden)
Mária Švecová
2010-04-01
Full Text Available Target tracking using time of arrival measurements belongs to the primary taskssolved within radar signal processing. In this paper, the Taylor series-based trackingalgorithm that uses time of arrival measurements for through wall tracking of the movingtarget is introduced. The proposed algorithm is derived from the Taylor series methodapplied for target localization. In contrast to the Taylor series method, the Taylor seriesbasedtracking algorithm exploits for target positioning not only actual time of arrivalmeasurements, but also the target position estimated in the previous time instant. In orderto improve the tracking ability of the proposed algorithm, a suitable weighting of the inputdata of the algorithm is applied. The performance of the Taylor series-based trackingalgorithm will be compared with the performance of the direct calculation method andlinear Kalman filtering. For that purpose, two real scenarios of through wall tracking of amoving person will be analysed. The obtained results will show very clearly that the newTaylor series based tracking algorithm introduced in this paper can provide the betterestimate of the target trajectory than the other tested localization and tracking algorithms.
Articulated Human Motion Tracking Using Sequential Immune Genetic Algorithm
Directory of Open Access Journals (Sweden)
Yi Li
2013-01-01
Full Text Available We formulate human motion tracking as a high-dimensional constrained optimization problem. A novel generative method is proposed for human motion tracking in the framework of evolutionary computation. The main contribution is that we introduce immune genetic algorithm (IGA for pose optimization in latent space of human motion. Firstly, we perform human motion analysis in the learnt latent space of human motion. As the latent space is low dimensional and contents the prior knowledge of human motion, it makes pose analysis more efficient and accurate. Then, in the search strategy, we apply IGA for pose optimization. Compared with genetic algorithm and other evolutionary methods, its main advantage is the ability to use the prior knowledge of human motion. We design an IGA-based method to estimate human pose from static images for initialization of motion tracking. And we propose a sequential IGA (S-IGA algorithm for motion tracking by incorporating the temporal continuity information into the traditional IGA. Experimental results on different videos of different motion types show that our IGA-based pose estimation method can be used for initialization of motion tracking. The S-IGA-based motion tracking method can achieve accurate and stable tracking of 3D human motion.
A novel particle tracking algorithm using polar coordinate system similarity
Institute of Scientific and Technical Information of China (English)
Xiaodong Ruan; Wenfeng Zhao; Yunming Chen
2005-01-01
A new algorithm using polar coordinate system similarity (PCSS) for tracking particle in particle tracking velocimetry (PTV) is proposed. The essence of the algorithm is to consider simultaneously the changes of the distance and angle of surrounding particles relative to the object particle.Monte Carlo simulations of a solid body rotational flow and a parallel shearing flow are used to investigate flows measurable by PCSS and the influences of experimental parameters on the implementation of the new algorithm. The results indicate that the PCSS algorithm can be applied to flows subjected to strong rotation and is not sensitive to experimental parameters in comparison with the conventional binary image cross-correlation (BICC) algorithm. Finally, PCSS is applied to images of a real experiment.
Airborne target tracking algorithm against oppressive decoys in infrared imagery
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.
Muraru, Denisa; Spadotto, Veronica; Cecchetto, Antonella; Romeo, Gabriella; Aruta, Patrizia; Ermacora, Davide; Jenei, Csaba; Cucchini, Umberto; Iliceto, Sabino; Badano, Luigi P
2016-11-01
(i) To validate a new software for right ventricular (RV) analysis by 3D echocardiography (3DE) against cardiac magnetic resonance (CMR); (ii) to assess the accuracy of different measurement approaches; and (iii) to explore any benefits vs. the previous software. We prospectively studied with 3DE and CMR 47 patients (14-82 years, 28 men) having a wide range of RV end-diastolic volumes (EDV 82-354 mL at CMR) and ejection fractions (EF 34-81%). Multi-beat RV 3DE data sets were independently analysed with the new software using both automated and manual editing options, as well as with the previous software. RV volume reproducibility was tested in 15 random patients. RV volumes and EF measurements by the new software had an excellent accuracy (bias ± SD: -15 ± 24 mL for EDV; 1.4 ± 4.9% for EF) and reproducibility compared with CMR, provided that the RV borders automatically tracked by software were systematically edited by operator. The automated analysis option underestimated the EDV, overestimated the ESV, and largely underestimated the EF (bias ± SD: -17 ± 10%). RV volumes measured with the new software using manual editing showed similar accuracy, but lower inter-observer variability and shorter analysis time (3-5') in comparison with the previous software. Novel vendor-independent 3DE software enables an accurate, reproducible and faster quantitation of RV volumes and ejection fraction. Rather than optional, systematic verification of border tracking quality and manual editing are mandatory to ensure accurate 3DE measurements. These findings are relevant for echocardiography laboratories aiming to implement 3DE for RV analysis for both research and clinical purposes. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2015. For permissions please email: journals.permissions@oup.com.
Development of target-tracking algorithms using neural network
Energy Technology Data Exchange (ETDEWEB)
Park, Dong Sun; Lee, Joon Whaoan; Yoon, Sook; Baek, Seong Hyun; Lee, Myung Jae [Chonbuk National University, Chonjoo (Korea)
1998-04-01
The utilization of remote-control robot system in atomic power plants or nuclear-related facilities grows rapidly, to protect workers form high radiation environments. Such applications require complete stability of the robot system, so that precisely tracking the robot is essential for the whole system. This research is to accomplish the goal by developing appropriate algorithms for remote-control robot systems. A neural network tracking system is designed and experimented to trace a robot Endpoint. This model is aimed to utilized the excellent capabilities of neural networks; nonlinear mapping between inputs and outputs, learning capability, and generalization capability. The neural tracker consists of two networks for position detection and prediction. Tracking algorithms are developed and experimented for the two models. Results of the experiments show that both models are promising as real-time target-tracking systems for remote-control robot systems. (author). 10 refs., 47 figs.
Study of hardware implementations of fast tracking algorithms
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.
The Seeding tracking algorithm for a scintillating detector at LHCb
Amhis, Y; De Cian, M; Nikodem, T; Polci, F
2014-01-01
The project of the LHCb upgraded detector foreseens the presence of a Scintillating Fiber Tracker (SciFi). This note describes the algorithm used for reconstructing standalone tracks in the SciFi, called $Seeding$. This algorithm is crucial for reconstructing tracks generated by long lived particles such as $K^0_s$. The main performances on simulated samples for running conditions expected in future data taking after the upgrade, namely a luminosity larger than $\\mathcal{L} = 2 \\times 10^{33} cm^{-2}s^{1}$, are also discussed.
An eddy tracking algorithm based on dynamical systems theory
Conti, Daniel; Orfila, Alejandro; Mason, Evan; Sayol, Juan Manuel; Simarro, Gonzalo; Balle, Salvador
2016-11-01
This work introduces a new method for ocean eddy detection that applies concepts from stationary dynamical systems theory. The method is composed of three steps: first, the centers of eddies are obtained from fixed points and their linear stability analysis; second, the size of the eddies is estimated from the vorticity between the eddy center and its neighboring fixed points, and, third, a tracking algorithm connects the different time frames. The tracking algorithm has been designed to avoid mismatching connections between eddies at different frames. Eddies are detected for the period between 1992 and 2012 using geostrophic velocities derived from AVISO altimetry and a new database is provided for the global ocean.
National Research Council Canada - National Science Library
Caroline A. Rickards; Nisarg Vyas; Kathy L. Ryan; Kevin R. Ward; David Andre; Gennifer M. Hurst; Chelsea R. Barrera; Victor A. Convertino
2014-01-01
.... The purpose of this study was to test the hypothesis that low-level physiological signals can be used to develop a machine-learning algorithm for tracking changes in central blood volume that will...
An object tracking algorithm with embedded gyro information
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.
Visual tracking method based on cuckoo search algorithm
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.
Object tracking algorithm based on contextual visual saliency
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.
Solar Load Voltage Tracking for Water Pumping: An Algorithm
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 .
A baseline algorithm for face detection and tracking in video
Manohar, Vasant; Soundararajan, Padmanabhan; Korzhova, Valentina; Boonstra, Matthew; Goldgof, Dmitry; Kasturi, Rangachar
2007-10-01
Establishing benchmark datasets, performance metrics and baseline algorithms have considerable research significance in gauging the progress in any application domain. These primarily allow both users and developers to compare the performance of various algorithms on a common platform. In our earlier works, we focused on developing performance metrics and establishing a substantial dataset with ground truth for object detection and tracking tasks (text and face) in two video domains -- broadcast news and meetings. In this paper, we present the results of a face detection and tracking algorithm on broadcast news videos with the objective of establishing a baseline performance for this task-domain pair. The detection algorithm uses a statistical approach that was originally developed by Viola and Jones and later extended by Lienhart. The algorithm uses a feature set that is Haar-like and a cascade of boosted decision tree classifiers as a statistical model. In this work, we used the Intel Open Source Computer Vision Library (OpenCV) implementation of the Haar face detection algorithm. The optimal values for the tunable parameters of this implementation were found through an experimental design strategy commonly used in statistical analyses of industrial processes. Tracking was accomplished as continuous detection with the detected objects in two frames mapped using a greedy algorithm based on the distances between the centroids of bounding boxes. Results on the evaluation set containing 50 sequences (~ 2.5 mins.) using the developed performance metrics show good performance of the algorithm reflecting the state-of-the-art which makes it an appropriate choice as the baseline algorithm for the problem.
Performance Assessment of Hybrid Data Fusion and Tracking Algorithms
DEFF Research Database (Denmark)
Sand, Stephan; Mensing, Christian; Laaraiedh, Mohamed
2009-01-01
This paper presents an overview on the performance of hybrid data fusion and tracking algorithms evaluated in the WHERE consortium. The focus is on three scenarios. For the small scale indoor scenario with ultra wideband (UWB) complementing cellular communication systems, the accuracy can vary in...
Comparison of tracking algorithms implemented in OpenCV
Directory of Open Access Journals (Sweden)
Janku Peter
2016-01-01
Full Text Available Computer vision is very progressive and modern part of computer science. From scientific point of view, theoretical aspects of computer vision algorithms prevail in many papers and publications. The underlying theory is really important, but on the other hand, the final implementation of an algorithm significantly affects its performance and robustness. For this reason, this paper tries to compare real implementation of tracking algorithms (one part of computer vision problem, which can be found in the very popular library OpenCV. Moreover, the possibilities of optimizations are discussed.
Encoding color information for visual tracking: Algorithms and benchmark.
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.
High speed railway track dynamics models, algorithms and applications
Lei, Xiaoyan
2017-01-01
This book systematically summarizes the latest research findings on high-speed railway track dynamics, made by the author and his research team over the past decade. It explores cutting-edge issues concerning the basic theory of high-speed railways, covering the dynamic theories, models, algorithms and engineering applications of the high-speed train and track coupling system. Presenting original concepts, systematic theories and advanced algorithms, the book places great emphasis on the precision and completeness of its content. The chapters are interrelated yet largely self-contained, allowing readers to either read through the book as a whole or focus on specific topics. It also combines theories with practice to effectively introduce readers to the latest research findings and developments in high-speed railway track dynamics. It offers a valuable resource for researchers, postgraduates and engineers in the fields of civil engineering, transportation, highway & railway engineering.
A Robust Algorithm of Contour Extraction for Vehicle Tracking
Institute of Scientific and Technical Information of China (English)
FANZhimin; ZHOUJie; GAODashan
2003-01-01
Contour extraction of moving vehicle is an important and challenging issue in traffic surveillance. In this paper, a robust algorithm is proposed for contour ex-traction and moving vehicle tracking. First, we establish a modified snake model and utilize the directional infor-mation of the edge map to guide the snaxels' behavior.Then an adaptive shape restriction is embedded into the algorithm to govern the scope of the snake's motion, and Kalman filter is employed to estimate spatio-temporal rela-tionship between successive frames. In addition~ multiple refinements are suggested to compensate for the snake's vulnerability to fake edges. All of them contribute to a ro-bust overall performance in contour extraction and vehicle tracking. Experimental results in real traffic scene prove the effectiveness of our algorithm.The comparison with conventional snakes is also provided.
Moving Vehicle Detection and Tracking Algorithm in Traffic Video
Directory of Open Access Journals (Sweden)
Shisong Zhu
2013-06-01
Full Text Available Aiming at the defects and shortages of traditional moving vehicles detection algorithms, by the analysis and comparison of the existing detection algorithms, we propose an algorithm that combined with frames with symmetric difference and background difference to detect moving vehicle in this paper. First, two different difference images by using frames with symmetric difference and background difference are gained respectively and two binary images can be gained by the appropriate threshold, then the contour of moving vehicles can be extracted by applying OR operation in the two binary images. Finally, the precise moving vehicles will be gained by mathematic morphological methods. In this paper we use Harris operator, Feature Points such as edges and corners are extracted, followed by block-matching to track the Feature Points in successive viedo frames. Many vehicles can be tracked at the same time automatically since the information is obtained from video sequences.
Efficient Algorithm for Railway Tracks Detection Using Satellite Imagery
Directory of Open Access Journals (Sweden)
Ali Javed
2012-10-01
Full Text Available Satellite imagery can produce maps including roads, railway tracks, buildings, bridges, oceans, lakes, rivers, etc. In developed countries like USA, Canada, Australia, Europe, images produced by Google map are of high resolution and good quality. On the other hand, mostly images of the third world countries like Pakistan, Asian and African countries are of poor quality and not clearly visible. Similarly railway tracks of these countries are hardly visible in Google map. We have developed an efficient algorithm for railway track detection from a low quality image of Google map. This would lead to detect damaged railway track, railway crossings and help to schedule/divert locomotive movements in order to avoid catastrophe.
Area Variation Based Color Snake Algorithm for Moving Object Tracking
Institute of Scientific and Technical Information of China (English)
Shoum-ik ROYCHOUDHURY; Young-joon HAN
2010-01-01
A snake algorithm has been known that it has a strong point in extracting the exact contour of an object.But it is apt to be influenced by scattered edges around the control points.Since the shape of a moving object in 2D image changes a lot due ta its rotation and translation in the 3D space,the conventional algorithm that takes into account slowly moving objects cannot provide an appropriate solution.To utilize the advantages of the snake algrithm while minimizing the drawbacks,this paper proposes the area variation based color snake algorithm for moving object tracking.The proposed algorithm includes a new energy term which is used for preserving the shape of an object between two consecutive inages.The proposed one can also segment precisely interesting objects on complex image since it is based on color information.Experiment results show that the proposed algorithm is very effective in various environments.
Indian Academy of Sciences (India)
V Vaidehi; K Kalavidya; S Indira Gandhi
2004-04-01
The interacting multiple model (IMM) algorithm has proved to be useful in tracking maneuvering targets. Tracking accuracy can be further improved using data fusion. Tracking of multiple targets using multiple sensors and fusing them at a central site using centralized architecture involves communication of large volumes of measurements to a common site. This results in heavy processing requirement at the central site. Moreover, track updates have to be obtained in the fusion centre before the next measurement arrives. For solving this computational complexity, a cluster-based parallel processing solution is presented in this paper. In this scheme, measurements are sent to the data fusion centre where the measurements are partitioned and given to the slave processors in the cluster. The slave processors use the IMM algorithm to get accurate updates of the tracks. The master processor collects the updated tracks and performs data fusion using ‘weight decision approach’. The improvement in the computation time using clusters in the data fusion centre is presented in this paper.
Directory of Open Access Journals (Sweden)
Shahamatnia Ehsan
2016-01-01
Full Text Available Developing specialized software tools is essential to support studies of solar activity evolution. With new space missions such as Solar Dynamics Observatory (SDO, solar images are being produced in unprecedented volumes. To capitalize on that huge data availability, the scientific community needs a new generation of software tools for automatic and efficient data processing. In this paper a prototype of a modular framework for solar feature detection, characterization, and tracking is presented. To develop an efficient system capable of automatic solar feature tracking and measuring, a hybrid approach combining specialized image processing, evolutionary optimization, and soft computing algorithms is being followed. The specialized hybrid algorithm for tracking solar features allows automatic feature tracking while gathering characterization details about the tracked features. The hybrid algorithm takes advantages of the snake model, a specialized image processing algorithm widely used in applications such as boundary delineation, image segmentation, and object tracking. Further, it exploits the flexibility and efficiency of Particle Swarm Optimization (PSO, a stochastic population based optimization algorithm. PSO has been used successfully in a wide range of applications including combinatorial optimization, control, clustering, robotics, scheduling, and image processing and video analysis applications. The proposed tool, denoted PSO-Snake model, was already successfully tested in other works for tracking sunspots and coronal bright points. In this work, we discuss the application of the PSO-Snake algorithm for calculating the sidereal rotational angular velocity of the solar corona. To validate the results we compare them with published manual results performed by an expert.
A NOVEL FAST MOVING OBJECT CONTOUR TRACKING ALGORITHM
Institute of Scientific and Technical Information of China (English)
An Guocheng; Yang Hao; Wu Zhenyang
2009-01-01
If a somewhat fast moving object exists in a complicated tracking environment, snake's nodes may fall into the inaccurate local minima. We propose a mean shift snake algorithm to solve this problem. However, if the object goes beyond the limits of mean shift snake module operation in successive sequences, mean shift snake's nodes may also fall into the local minima in their moving to the new object position. This paper presents a motion compensation strategy by using particle filter; therefore a new Particle Filter Mean Shift Snake (PFMSS) algorithm is proposed which combines particle filter with mean shift snake to fulfill the estimation of the fast moving object contour. Firstly, the fast moving object is tracked by particle filter to create a coarse position which is used to initialize the mean shift algorithm. Secondly, the whole relevant motion information is used to compensate the snake's node positions. Finally, snake algorithm is used to extract the exact object contour and the useful information of the object is fed back. Some real world sequences are tested and the results show that the novel tracking method have a good performance with high accuracy in solving the fast moving problems in cluttered background.
CVFEM for Multiphase Flow with Disperse and Interface Tracking, and Algorithms Performances
Directory of Open Access Journals (Sweden)
M. Milanez
2015-12-01
Full Text Available A Control-Volume Finite-Element Method (CVFEM is newly formulated within Eulerian and spatial averaging frameworks for effective simulation of disperse transport, deposit distribution and interface tracking. Their algorithms are implemented alongside an existing continuous phase algorithm. Flow terms are newly implemented for a control volume (CV fixed in a space, and the CVs' equations are assembled based on a finite element method (FEM. Upon impacting stationary and moving boundaries, the disperse phase changes its phase and the solver triggers identification of CVs with excess deposit and their neighboring CVs for its accommodation in front of an interface. The solver then updates boundary conditions on the moving interface as well as domain conditions on the accumulating deposit. Corroboration of the algorithms' performances is conducted on illustrative simulations with novel and existing Eulerian and Lagrangian solutions, such as (- other, i. e. external methods with analytical and physical experimental formulations, and (- characteristics internal to CVFEM.
Level-1 pixel based tracking trigger algorithm for LHC upgrade
Moon, Chang-Seong
2015-01-01
The Pixel Detector is the innermost detector of the tracking system of the Compact Muon Solenoid (CMS) experiment at CERN Large Hadron Collider (LHC). It precisely determines the interaction point (primary vertex) of the events and the possible secondary vertexes due to heavy flavours ($b$ and $c$ quarks); it is part of the overall tracking system that allows reconstructing the tracks of the charged particles in the events and combined with the magnetic field to measure their impulsion. The pixel detector allows measuring the tracks in the region closest to the interaction point. The Level-1 (real-time) pixel based tracking trigger is a novel trigger system that is currently being studied for the LHC upgrade. An important goal is developing real-time track reconstruction algorithms able to cope with very high rates and high flux of data in a very harsh environment. The pixel detector has an especially crucial role in precisely identifying the primary vertex of the rare physics events from the large pile-up (P...
Face pose tracking using the four-point algorithm
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.
Improved chirp scaling algorithm for parallel-track bistatic SAR
Institute of Scientific and Technical Information of China (English)
Li Feng; Li Shu; Zhao Yigong
2009-01-01
The curvature factor of the parallel-track bistatic SAR is range dependent, even without variation of the effective velocity. Accounting for this new characteristic, a parallel-track chirp scaling algorithm (CSA) is derived, by introducing the method of removal of range walk (RRW) in the time domain. Using the RRW before the CSA, this method can reduce the varying range of the curvature factor, without increasing the computation load obviously. The azimuth dependence of the azimuth-FM rate, resulting from the RRW, is compensated by the nonlinear chirp scaling factor. Therefore, the algorithm is extended into stripmap imaging. The realization of the method is presented and is verified by the simulation results.
A stencil-like volume of fluid (VOF) method for tracking free interface
Institute of Scientific and Technical Information of China (English)
LI Xiao-wei; FAN Jun-fei
2008-01-01
A stencil-like volume of fluid (VOF) method is proposed for tracking free interface. A stencil on a grid cell is worked out according to the normal direction of the interface, in which only three interface positions are possible in 2D cases, and the interface can be reconstructed by only requiring the known local volume fraction information. On the other hand, the fluid-occupying-length is defined on each side of the stencil, through which a unified fluid-occupying volume model and a unified algorithm can be obtained to solve the interface advection equation. The method is suitable for the arbitrary geometry of the grid cell, and is extendible to 3D cases. Typical numerical examples show that the current method can give "sharp" results for tracking free interface.
Level-1 pixel based tracking trigger algorithm for LHC upgrade
Moon, C.-S.; Savoy-Navarro, A.
2015-10-01
The Pixel Detector is the innermost detector of the tracking system of the Compact Muon Solenoid (CMS) experiment at CERN Large Hadron Collider (LHC) . It precisely determines the interaction point (primary vertex) of the events and the possible secondary vertexes due to heavy flavours (b and c quarks); it is part of the overall tracking system that allows reconstructing the tracks of the charged particles in the events and combined with the magnetic field to measure their momentum. The pixel detector allows measuring the tracks in the region closest to the interaction point. The Level-1 (real-time) pixel based tracking trigger is a novel trigger system that is currently being studied for the LHC upgrade. An important goal is developing real-time track reconstruction algorithms able to cope with very high rates and high flux of data in a very harsh environment. The pixel detector has an especially crucial role in precisely identifying the primary vertex of the rare physics events from the large pile-up (PU) of events. The goal of adding the pixel information already at the real-time level of the selection is to help reducing the total level-1 trigger rate while keeping an high selection capability. This is quite an innovative and challenging objective for the experiments upgrade for the High Luminosity LHC (HL-LHC) . The special case here addressed is the CMS experiment. This document describes exercises focusing on the development of a fast pixel track reconstruction where the pixel track matches with a Level-1 electron object using a ROOT-based simulation framework.
Multiple extended target tracking algorithm based on Gaussian surface matrix
Institute of Scientific and Technical Information of China (English)
Jinlong Yang; Peng Li; Zhihua Li; Le Yang
2016-01-01
In this paper, we consider the problem of irregular shapes tracking for multiple extended targets by introducing the Gaussian surface matrix (GSM) into the framework of the random finite set (RFS) theory. The Gaussian surface function is constructed first by the measurements, and it is used to define the GSM via a mapping function. We then integrate the GSM with the probability hypothesis density (PHD) filter, the Bayesian recursion formulas of GSM-PHD are derived and the Gaussian mixture implementation is employed to obtain the closed-form solutions. Moreover, the estimated shapes are designed to guide the measurement set sub-partition, which can cope with the problem of the spatialy close target tracking. Simulation results show that the proposed algorithm can effectively estimate irregular target shapes and exhibit good robustness in cross extended target tracking.
Duan, Qi; Angelini, Elsa D.; Herz, Susan L.; Ingrassia, Christopher M.; Gerard, Olivier; Costa, Kevin D.; Holmes, Jeffrey W.; Laine, Andrew F.
2005-04-01
With relatively high frame rates and the ability to acquire volume data sets with a stationary transducer, 3D ultrasound systems, based on matrix phased array transducers, provide valuable three-dimensional information, from which quantitative measures of cardiac function can be extracted. Such analyses require segmentation and visual tracking of the left ventricular endocardial border. Due to the large size of the volumetric data sets, manual tracing of the endocardial border is tedious and impractical for clinical applications. Therefore the development of automatic methods for tracking three-dimensional endocardial motion is essential. In this study, we evaluate a four-dimensional optical flow motion tracking algorithm to determine its capability to follow the endocardial border in three dimensional ultrasound data through time. The four-dimensional optical flow method was implemented using three-dimensional correlation. We tested the algorithm on an experimental open-chest dog data set and a clinical data set acquired with a Philips' iE33 three-dimensional ultrasound machine. Initialized with left ventricular endocardial data points obtained from manual tracing at end-diastole, the algorithm automatically tracked these points frame by frame through the whole cardiac cycle. A finite element surface was fitted through the data points obtained by both optical flow tracking and manual tracing by an experienced observer for quantitative comparison of the results. Parameterization of the finite element surfaces was performed and maps displaying relative differences between the manual and semi-automatic methods were compared. The results showed good consistency between manual tracing and optical flow estimation on 73% of the entire surface with fewer than 10% difference. In addition, the optical flow motion tracking algorithm greatly reduced processing time (about 94% reduction compared to human involvement per cardiac cycle) for analyzing cardiac function in three
Path-tracking Algorithm for Aircraft Fuel Tank Inspection Robots
Niu Guochen; Wang Li; Gao Qingji; Hu Dandan
2014-01-01
A 3D path-tracking algorithm based on end- point approximation is proposed to implement the path traversal of robots designed to inspect aircraft fuel tanks. Kinematic models of single-joint segments and multiple- joint segments were created. First, each joint segment of the path was divided into many equal sections and the rotation angle was computed. The rotation angle was found for the plane determined by one divided point and the secondary terminal joint segment. Second, the shortest dist...
Low-Level Vision Algorithms for Localization, Classification, and Tracking
Kevin N. Gabayan
2003-01-01
Camera networks can provide images of detected objects that vary in perspective and level of obstruction. To improve the understanding of visual events, vision algorithms are implemented in a wireless sensor network. Methods were developed to fuse data from multiple cameras to improve object identification and location in the presence of obstructions. Training sets of images allow classification of objects into familiar categories. Feature-based object correspondence is used to track multiple...
Robust kernel-based tracking algorithm with background contrasting
Institute of Scientific and Technical Information of China (English)
Rongli Liu; Zhongliang Jing
2012-01-01
The mean-shift algorithm has achieved considerable success in object tracking due to its simplicity and efficiency. Color histogram is a common feature in the description of an object. However, the kernel-based color histogram may not have the ability to discriminate the object from clutter background. To boost the discriminating ability of the feature, based on background contrasting, this letter presents an improved Bhattacharyya similarity metric for mean-shift tracking. Experiments show that the proposed tracker is more robust in relation to background clutter.%The mean-shift algorithm has achieved considerable success in object tracking due to its simplicity and efficiency.Color histogram is a common feature in the description of an object.However,the kernel-based color histogram may not have the ability to discriminate the object from clutter background.To boost the discriminating ability of the feature,based on background contrasting,this letter presents an improved Bhattacharyya similarity metric for mean-shift tracking.Experiments show that the proposed tracker is more robust in relation to background clutter.
The Differential Equation Algorithm for General Deformed Swept Volumes
Institute of Scientific and Technical Information of China (English)
汪国平; 华宣积; 孙家广
2000-01-01
The differential equation approach for characterizing swept volume boundaries is extended to include objects experiencing deformation. For deformed swept volume, it is found that the structure and algorithm of sweep-envelope differential equation (SEDE) are similar between the deformed and the rigid swept volumes. The efficiency of SEDE approach for deformed swept volume is proved with an example.
An efficient and accurate 3D displacements tracking strategy for digital volume correlation
Pan, Bing
2014-07-01
Owing to its inherent computational complexity, practical implementation of digital volume correlation (DVC) for internal displacement and strain mapping faces important challenges in improving its computational efficiency. In this work, an efficient and accurate 3D displacement tracking strategy is proposed for fast DVC calculation. The efficiency advantage is achieved by using three improvements. First, to eliminate the need of updating Hessian matrix in each iteration, an efficient 3D inverse compositional Gauss-Newton (3D IC-GN) algorithm is introduced to replace existing forward additive algorithms for accurate sub-voxel displacement registration. Second, to ensure the 3D IC-GN algorithm that converges accurately and rapidly and avoid time-consuming integer-voxel displacement searching, a generalized reliability-guided displacement tracking strategy is designed to transfer accurate and complete initial guess of deformation for each calculation point from its computed neighbors. Third, to avoid the repeated computation of sub-voxel intensity interpolation coefficients, an interpolation coefficient lookup table is established for tricubic interpolation. The computational complexity of the proposed fast DVC and the existing typical DVC algorithms are first analyzed quantitatively according to necessary arithmetic operations. Then, numerical tests are performed to verify the performance of the fast DVC algorithm in terms of measurement accuracy and computational efficiency. The experimental results indicate that, compared with the existing DVC algorithm, the presented fast DVC algorithm produces similar precision and slightly higher accuracy at a substantially reduced computational cost. © 2014 Elsevier Ltd.
GPU implementations of online track finding algorithms at PANDA
Energy Technology Data Exchange (ETDEWEB)
Herten, Andreas; Stockmanns, Tobias; Ritman, James [Institut fuer Kernphysik, Forschungszentrum Juelich GmbH (Germany); Adinetz, Andrew; Pleiter, Dirk [Juelich Supercomputing Centre, Forschungszentrum Juelich GmbH (Germany); Kraus, Jiri [NVIDIA GmbH (Germany); Collaboration: PANDA-Collaboration
2014-07-01
The PANDA experiment is a hadron physics experiment that will investigate antiproton annihilation in the charm quark mass region. The experiment is now being constructed as one of the main parts of the FAIR facility. At an event rate of 2 . 10{sup 7}/s a data rate of 200 GB/s is expected. A reduction of three orders of magnitude is required in order to save the data for further offline analysis. Since signal and background processes at PANDA have similar signatures, no hardware-level trigger is foreseen for the experiment. Instead, a fast online event filter is substituting this element. We investigate the possibility of using graphics processing units (GPUs) for the online tracking part of this task. Researched algorithms are a Hough Transform, a track finder involving Riemann surfaces, and the novel, PANDA-specific Triplet Finder. This talk shows selected advances in the implementations as well as performance evaluations of the GPU tracking algorithms to be used at the PANDA experiment.
ALGORITHMS FOR TRACKING MANEUVERING TARGET WITH PHASED ARRAY RADAR
Institute of Scientific and Technical Information of China (English)
1998-01-01
Several typical algorithms for tracking maneuvering target with phased array radar are studied in this paper. The constant gain filter with multiple models is analyzed. A typical method for adaptively controlling the sampling interval is modified. The performance of the single model and multiple model estimator with uniform and variable sampling interval are evaluated and compared. It is shown by the simulation results that it is necessary to apply the adaptive sampling policy based on the multiple model method when the maneuvering targets are tracked by the phased array radar since saving radar resources is more important. The adaptive algorithms of variable sampling interval are better than the algorithms of variable model. The adaptive policy to determine the sampling interval based on multiple model are superior than those based on the single-model filter, because IMM estimator can adapt to the maneuver more quickly and the prediction covariance of IMM is the more sensitive and more reliable index than residual to determine the sampling interval. With IMM-based method, lower sampling interval is required for a certain accuracy.
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.
Tracking algorithms using log-polar mapped image coordinates
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.
Development of algorithm for single axis sun tracking system
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.
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.
Directory of Open Access Journals (Sweden)
Woonki Na
2017-03-01
Full Text Available This paper presents an improved maximum power point tracking (MPPT algorithm using a fuzzy logic controller (FLC in order to extract potential maximum power from photovoltaic cells. The objectives of the proposed algorithm are to improve the tracking speed, and to simultaneously solve the inherent drawbacks such as slow tracking in the conventional perturb and observe (P and O algorithm. The performances of the conventional P and O algorithm and the proposed algorithm are compared by using MATLAB/Simulink in terms of the tracking speed and steady-state oscillations. Additionally, both algorithms were experimentally validated through a digital signal processor (DSP-based controlled-boost DC-DC converter. The experimental results show that the proposed algorithm performs with a shorter tracking time, smaller output power oscillation, and higher efficiency, compared with the conventional P and O algorithm.
Directory of Open Access Journals (Sweden)
Yutian Cao
2015-12-01
Full Text Available In this paper, by analyzing the characteristics of infrared moving targets, a Symmetric Frame Differencing Target Detection algorithm based on local clustering segmentation is proposed. In consideration of the high real-time performance and accuracy of traditional symmetric differencing, this novel algorithm uses local grayscale clustering to accomplish target detection after carrying out symmetric frame differencing to locate the regions of change. In addition, the mean shift tracking algorithm is also improved to solve the problem of missed targets caused by error convergence. As a result, a kernel-based mean shift target tracking algorithm based on detection updates is also proposed. This tracking algorithm makes use of the interaction between detection and tracking to correct the tracking errors in real time and to realize robust target tracking in complex scenes. In addition, the validity, robustness and stability of the proposed algorithms are all verified by experiments on mid-infrared aerial sequences with vehicles as targets.
Vision-based vehicle detection and tracking algorithm design
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.
A maximum power point tracking algorithm for photovoltaic applications
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.
Algorithms for High-Speed Noninvasive Eye-Tracking System
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
A new algorithm of brain volume contours segmentation
Institute of Scientific and Technical Information of China (English)
吴建明; 施鹏飞
2003-01-01
This paper explores brain CT slices segmentation technique and some related problems, including contours segmentation algorithms, edge detector, algorithm evaluation and experimental results. This article describes a method for contour-based segmentation of anatomical structures in 3D medical data sets. With this method, the user manually traces one or more 2D contours of an anatomical structure of interest on parallel planes arbitrarily cutting the data set. The experimental results showes the segmentation based on 3D brain volume and 2D CT slices. The main creative contributions in this paper are: (1) contours segmentation algorithm; (2) edge detector; (3) algorithm evaluation.
Computationally Efficient DOA Tracking Algorithm in Monostatic MIMO Radar with Automatic Association
Directory of Open Access Journals (Sweden)
Huaxin Yu
2014-01-01
Full Text Available We consider the problem of tracking the direction of arrivals (DOA of multiple moving targets in monostatic multiple-input multiple-output (MIMO radar. A low-complexity DOA tracking algorithm in monostatic MIMO radar is proposed. The proposed algorithm obtains DOA estimation via the difference between previous and current covariance matrix of the reduced-dimension transformation signal, and it reduces the computational complexity and realizes automatic association in DOA tracking. Error analysis and Cramér-Rao lower bound (CRLB of DOA tracking are derived in the paper. The proposed algorithm not only can be regarded as an extension of array-signal-processing DOA tracking algorithm in (Zhang et al. (2008, but also is an improved version of the DOA tracking algorithm in (Zhang et al. (2008. Furthermore, the proposed algorithm has better DOA tracking performance than the DOA tracking algorithm in (Zhang et al. (2008. The simulation results demonstrate effectiveness of the proposed algorithm. Our work provides the technical support for the practical application of MIMO radar.
A hybrid algorithm for tracking and following people using a robotic dog
M.C. Liem; A. Visser; F.C.A. Groen
2008-01-01
The capability to follow a person in a domestic environment is an important prerequisite for a robot companion. In this paper, a tracking algorithm is presented that makes it possible to follow a person using a small robot. This algorithm can track a person while moving around, regardless of the som
Geometry-Of-Fire Tracking Algorithm for Direct-Fire Weapon Systems
2015-09-01
NAVAL POSTGRADUATE SCHOOL MONTEREY, CALIFORNIA THESIS Approved for public release; distribution is unlimited GEOMETRY-OF- FIRE ...TRACKING ALGORITHM FOR DIRECT- FIRE WEAPON SYSTEMS by Caleb K. Khan September 2015 Thesis Advisor: Zachary Staples Co-Advisor: Xiaoping...2015 3. REPORT TYPE AND DATES COVERED Master’s Thesis 4. TITLE AND SUBTITLE GEOMETRY-OF- FIRE TRACKING ALGORITHM FOR DIRECT- FIRE WEAPON SYSTEMS
Rajan, R T; Loddo, F; Maggi, M; Ranieri, A; Abbrescia, M; Guida, R; Iaselli, G; Nuzzo, S; Pugliese, G; Roselli, G; Trentadue, R; Tupputi, b, S; Benussi, L; Bertani, M; Bianco, S; Fabbri, F; Cavallo, N; Cimmino, e, A; Lomidze, D; Noli, P; Paolucci, P; Piccolo, D; Polese, G; Sciacca, C; Baesso, g, P; Belli, G; Necchi, M; Ratti, S P; Pagano, D; Vitulo, P; Viviani, C; Dimitrov, A; Litov, L; Pavlov, B; Petkov, P; Genchev, V; Iaydjiev, P; Bunkowski, K; Kierzkowski, K; Konecki, M; Kudla, I; Pietrusinski, M; Pozniak, K
2009-01-01
In the CERN CMS experiment at LHC Collider special trigger signals called Technical Triggers will be used for the purpose of test and calibration. The Resistive Plate Chambers (RPC) based Technical Trigger system is a part of the CMS muon trigger system and is designed to detect cosmic muon tracks. It is based on two boards, namely RBC (RPC Balcony Collector) and TTU (Technical Trigger Unit). The proposed tracking algorithm (TA) written in VHDL and implemented in the TTU board detects single or multiple cosmic muon tracks at every bunch crossing along with their track lengths and corresponding chamber coordinates. The TA implementation in VHDL and its preliminary simulation results are presented.
Least Trimmed Squares Approach to Lucas-Kanade Algorithm in Object Tracking Problems
Directory of Open Access Journals (Sweden)
Yih-Lon Lin
2013-01-01
Full Text Available The object tracking problem is an important research topic in computer vision. For real applications such as vehicle tracking and face tracking, there are many efficient and real-time algorithms. In this study, we will focus on the Lucas-Kanade (LK algorithm for object tracking. Although this method is time consuming, it is effective in tracking accuracy and environment adaptation. In the standard LK method, the sum of squared errors is used as the cost function, while least trimmed squares is adopted as the cost function in this study. The resulting estimator is robust against outliers caused by noises and occlusions in the tracking process. Simulations are provided to show that the proposed algorithm outperforms the standard LK method in the sense that it is robust against the outliers in the object tracking problems.
Multi-Deme Parallel FGAs-Based Algorithm for Multitarget Tracking
Institute of Scientific and Technical Information of China (English)
无
2006-01-01
For data association in multisensor and multitarget tracking, a novel parallel algorithm is developed to improve the efficiency and real-time performance of FGAs-based algorithm. One Cluster of Workstation (COW) with Message Passing Interface (MPI) is built. The proposed Multi-Deme Parallel FGA (MDPFGA) is run on the platform. A serial of special MDPFGAs are used to determine the static and the dynamic solutions of generalized m-best S-D assignment problem respectively, as well as target states estimation in track management. Such an assignment-based parallel algorithm is demonstrated on simulated passive sensor track formation and maintenance problem. While illustrating the feasibility of the proposed algorithm in multisensor multitarget tracking, simulation results indicate that the MDPFGAs-based algorithm has greater efficiency and speed than the FGAs-based algorithm.
Track gauge optimisation of railway switches using a genetic algorithm
Pålsson, Björn A.; Nielsen, Jens C. O.
2012-01-01
A methodology for the optimisation of a prescribed track gauge variation (gauge widening) in the switch panel of a railway turnout (switch and crossing, S&C) is presented. The aim is to reduce rail profile degradation. A holistic approach is applied, where both routes and travel directions (moves) of traffic in the switch panel are considered simultaneously. The problem is formulated as a multi-objective minimisation problem which is solved using a genetic-type optimisation algorithm which provides a set of Pareto optimal solutions. The dynamic vehicle-turnout interaction is evaluated using a multi-body simulation tool and the energy dissipation in the wheel-rail contacts is used for the assessment of gauge parameters. Two different vehicle models are used, one freight car and one passenger train set, and a stochastic spread in wheel profile and wheel-rail friction coefficient is accounted for. It is found that gauge configurations with a large gauge-widening amplitude for the stock rail on the field side are optimal for both the through and diverging routes, while the results for the gauge side show a larger route dependence. The optimal gauge configurations are observed to be similar for both vehicle types.
Research on video target tracking technology based on improved SIFT algorithm
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.
Directory of Open Access Journals (Sweden)
Yu Fan
2016-10-01
Full Text Available In order to defend the hypersonic glide vehicle (HGV, a cost-effective single-model tracking algorithm using Cubature Kalman filter (CKF is proposed in this paper based on modified aerodynamic model (MAM as process equation and radar measurement model as measurement equation. In the existing aerodynamic model, the two control variables attack angle and bank angle cannot be measured by the existing radar equipment and their control laws cannot be known by defenders. To establish the process equation, the MAM for HGV tracking is proposed by using additive white noise to model the rates of change of the two control variables. For the ease of comparison several multiple model algorithms based on CKF are presented, including interacting multiple model (IMM algorithm, adaptive grid interacting multiple model (AGIMM algorithm and hybrid grid multiple model (HGMM algorithm. The performances of these algorithms are compared and analyzed according to the simulation results. The simulation results indicate that the proposed tracking algorithm based on modified aerodynamic model has the best tracking performance with the best accuracy and least computational cost among all tracking algorithms in this paper. The proposed algorithm is cost-effective for HGV tracking.
Randomized algorithms for tracking distributed count, frequencies, and ranks
DEFF Research Database (Denmark)
Zengfeng, Huang; Ke, Yi; Zhang, Qin
2012-01-01
We show that randomization can lead to significant improvements for a few fundamental problems in distributed tracking. Our basis is the count-tracking problem, where there are k players, each holding a counter ni that gets incremented over time, and the goal is to track an ∑-approximation...
A Tracking-Based Target Locating Algorithm in Wireless Sensor Networks
Institute of Scientific and Technical Information of China (English)
SUN Xue-bin; ZHOU Zheng
2004-01-01
This paper proposes a tracking-based target locating algorithm to locate a target moving in a geographical region under the surveillance of a wireless sensor network. This algorithm first finds a sensor node that has detected the target, and then uses local messages between neighboring nodes to track the trail of the target. The authors implement this algorithm and compare it with an optimized flood-based target locating algorithm. Simulation results show that this algorithm effectively reduces the message transmission, conserves energy and consequently enhances the practicability of resource-limited wireless sensor networks.
IMPLEMENTATION OF OBJECT TRACKING ALGORITHMS ON THE BASIS OF CUDA TECHNOLOGY
Directory of Open Access Journals (Sweden)
B. A. Zalesky
2014-01-01
Full Text Available A fast version of correlation algorithm to track objects on video-sequences made by a nonstabilized camcorder is presented. The algorithm is based on comparison of local correlations of the object image and regions of video-frames. The algorithm is implemented in programming technology CUDA. Application of CUDA allowed to attain real time execution of the algorithm. To improve its precision and stability, a robust version of the Kalman filter has been incorporated into the flowchart. Tests showed applicability of the algorithm to practical object tracking.
Algorithm of search and track of static and moving large-scale objects
Directory of Open Access Journals (Sweden)
Kalyaev Anatoly
2017-01-01
Full Text Available We suggest an algorithm for processing of a sequence, which contains images of search and track of static and moving large-scale objects. The possible software implementation of the algorithm, based on multithread CUDA processing, is suggested. Experimental analysis of the suggested algorithm implementation is performed.
Schöning, Andre
2016-01-01
Track reconstruction in high track multiplicity environments at current and future high rate particle physics experiments is a big challenge and very time consuming. The search for track seeds and the fitting of track candidates are usually the most time consuming steps in the track reconstruction. Here, a new and fast track reconstruction method based on hit triplets is proposed which exploits a three-dimensional fit model including multiple scattering and hit uncertainties from the very start, including the search for track seeds. The hit triplet based reconstruction method assumes a homogeneous magnetic field which allows to give an analytical solutions for the triplet fit result. This method is highly parallelizable, needs fewer operations than other standard track reconstruction methods and is therefore ideal for the implementation on parallel computing architectures. The proposed track reconstruction algorithm has been studied in the context of the Mu3e-experiment and a typical LHC experiment.
Schöning, André
2016-11-01
Track reconstruction in high track multiplicity environments at current and future high rate particle physics experiments is a big challenge and very time consuming. The search for track seeds and the fitting of track candidates are usually the most time consuming steps in the track reconstruction. Here, a new and fast track reconstruction method based on hit triplets is proposed which exploits a three-dimensional fit model including multiple scattering and hit uncertainties from the very start, including the search for track seeds. The hit triplet based reconstruction method assumes a homogeneous magnetic field which allows to give an analytical solutions for the triplet fit result. This method is highly parallelizable, needs fewer operations than other standard track reconstruction methods and is therefore ideal for the implementation on parallel computing architectures. The proposed track reconstruction algorithm has been studied in the context of the Mu3e-experiment and a typical LHC experiment.
The research of moving objects behavior detection and tracking algorithm in aerial video
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.
An image-tracking algorithm based on object center distance-weighting and image feature recognition
Institute of Scientific and Technical Information of China (English)
JIANG Shuhong; WANG Qin; ZHANG Jianqiu; HU Bo
2007-01-01
Areal-time image-tracking algorithm is proposed.which gives small weights to pixels farther from the object center and uses the quantized image gray scales as a template.It identifies the target's location by the mean-shift iteration method and arrives at the target's scale by using image feature recognition.It improves the kernel-based algorithm in tracking scale-changing targets.A decimation mcthod is proposed to track large-sized targets and real-time experimental results verify the effectiveness of the proposed algorithm.
A guidance and control algorithm for scent tracking micro-robotic vehicle swarms
Energy Technology Data Exchange (ETDEWEB)
Dohner, J.L. [Sandia National Labs., Albuquerque, NM (United States). Structural Dynamics Dept.
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.
Randomized Algorithms for Tracking Distributed Count, Frequencies, and Ranks
DEFF Research Database (Denmark)
Huang, Zengfeng; Yi, Ke; Zhang, Qin
2011-01-01
We show that randomization can lead to significant improvements for a few fundamental problems in distributed tracking. Our basis is the {\\em count-tracking} problem, where there are $k$ players, each holding a counter $n_i$ that gets incremented over time, and the goal is to track an $\\eps......$-approximation of their sum $n=\\sum_i n_i$ continuously at all times, using minimum communication. While the deterministic communication complexity of the problem is $\\Theta(k/\\eps \\cdot \\log N)$, where $N$ is the final value of $n$ when the tracking finishes, we show that with randomization, the communication cost can...
Modified algorithm for generating high volume fraction sphere packings
Valera, Roberto Roselló; Morales, Irvin Pérez; Vanmaercke, Simon; Morfa, Carlos Recarey; Cortés, Lucía Argüelles; Casañas, Harold Díaz-Guzmán
2015-06-01
Advancing front packing algorithms have proven to be very efficient in 2D for obtaining high density sets of particles, especially disks. However, the extension of these algorithms to 3D is not a trivial task. In the present paper, an advancing front algorithm for obtaining highly dense sphere packings is presented. It is simpler than other advancing front packing methods in 3D and can also be used with other types of particles. Comparison with respect to other packing methods have been carried out and a significant improvement in the volume fraction (VF) has been observed. Moreover, the quality of packings was evaluated with indicators other than VF. As additional advantage, the number of generated particles with the algorithm is linear with respect to time.
Exploration and extension of an improved Riemann track fitting algorithm
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.
Automatic face detection and tracking based on Adaboost with camshift algorithm
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.
MULTI-LAYER TRACK FUSION ALGORITHM BASED ON SUPPORTING DEGREE MATRIX
Institute of Scientific and Technical Information of China (English)
Zhang Wei; Quan Li; Zhang Ke
2012-01-01
The random noises of multi-sensor and the environment make observations uncertain and correlative,so the performance of fusion algorithms is reduced by using observations directly.To solve this problem,a multi-layer track fusion algorithm based on supporting degree matrix is proposed.Combined with the track fusion algorithm based on filtering step by step,it uses multi-sensor observations to establish supporting degree matrix and realize multi-layer fusion.Simulation results show its estimation precision is higher than the original algorithm and is increased by 20％ around.Therefore,it solves the problem of target tracking further in the distributed track fusion system.
A Sensor-based SLAM Algorithm for Camera Tracking vin Virtual Studio
Institute of Scientific and Technical Information of China (English)
Po Yang; Wenyan Wu; Mansour Moniri; Claude C. Chibelushi
2008-01-01
This paper addresses a sensor-based simultaneous localization and mapping (SLAM) algorithm for camera tracking in a virtual studio environment. The traditional camera tracking methods in virtual studios are vision-based or sensor-based. However, the chroma keying process in virtual studios requires color cues, such as blue background, to segment foreground objects to be inserted into images and videos. Chroma keying limits the application of vision-based tracking methods in virtual studios since the background cannot provide enough feature information. Furthermore, the conventional sensor-based tracking approaches suffer from the jitter, drift or expensive computation due to the characteristics of individual sensor system. Therefore, the SLAM techniques from the mobile robot area are first investigated and adapted to the camera tracking area. Then, a sensor-based SLAM extension algorithm for two dimensional (2D) camera tracking in virtual studio is described. Also, a technique called map adjustment is proposed to increase the accuracy and efficiency of the algorithm. The feasibility and robustness of the algorithm is shown by experiments. The simulation results demonstrate that the sensor-based SLAM algorithm can satisfy the fundamental 2D camera tracking requirement in virtual studio environment.
Multi-sensor fusion using an adaptive multi-hypothesis tracking algorithm
Kester, L.J.H.M.
2003-01-01
The purpose of a tracking algorithm is to associate data measured by one or more (moving) sensors to moving objects in the environment. The state of these objects that can be estimated with the tracking process depends on the type of data that is provided by these sensors. It is discussed how the
Real-time tracking of deformable objects based on MOK algorithm
Institute of Scientific and Technical Information of China (English)
Junhua Yan; Zhigang Wang; Shunfei Wang
2016-01-01
Thetraditional oriented FAST and rotated BRIEF (ORB) algorithm has problems of instability and repetition of keypoints and it does not possess scale invariance. In order to deal with these drawbacks, a modified ORB (MORB) algo-rithm is proposed. In order to improve the precision of matching and tracking, this paper puts forward an MOK algo-rithm that fuses MORB and Kanade-Lucas-Tomasi (KLT). By using Kalman, the object’s state in the next frame is predicted in order to reduce the size of search window and improve the real-time performance of object tracking. The experimental results show that the MOK algorithm can accurately track objects with deformation or with background clutters, exhi- biting higher robustness and accuracy on diverse datasets. Also, the MOK algorithm has a good real-time performance with the average frame rate reaching 90.8 fps.
Centralized Fuzzy Data Association Algorithm of Three-sensor Multi-target Tracking System
Directory of Open Access Journals (Sweden)
Zhaofeng Su
2014-02-01
Full Text Available For improving the effect of multi-target tracking in dense target and clutter scenario, a centralized fuzzy optimal assignment algorithm (CMS-FOA of three-sensor multi-target system is proposed. And on the base of this, a generalized probabilistic data association algorithm (CMS-FOAGPDA based on CMS-FOA algorithm is presented. The fusion algorithm gets effective 3-tuple of measurement set by using components of several satisfactory solutions of the fuzzy optimal assignment problem and then uses generalized probabilistic data association algorithm to calculate the update states of targets. Simulation results show that, in the aspect of multi-target tracking accuracy, CMS-FOA algorithm is superior to the optimal assignment (CMS-OA algorithm based on state estimate and CMS-FOAGPDA algorithm is better than CMS-FOA algorithm. But considering the time spent, CMS-FOA algorithm spends a minimum of time and CMS-FOAGPDA algorithm is exactly on the contrary. Therefore, compared with CMS-OA algorithm, the two algorithms presented in the study each has its advantages and should be chosen according to the needs of the actual application when in use.
Real time tracking with a silicon telescope prototype using the "artificial retina" algorithm
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.
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).
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.
A new algorithm of bearings-only multi-target tracking of bistatic system
Institute of Scientific and Technical Information of China (English)
Benlian XU; Zhiquan WANG
2006-01-01
Much research mainly focuses on the batch processing method (e.g. maximum likelihood method) when bearings-only multiple targets tracking of bistatic sonar system is considered. In this paper, the idea of recursive processing method is presented and employed, and corresponding data association algorithms, i.e. a multi-objective ant-colony-based optimization algorithm and an easy fast assignment algorithm are developed to solve the measurements-to-measurements and measurements-to-tracks data association problems of bistatic sonar system, respectively. Monte-Carlo simulations are induced to evaluate the effectiveness of the proposed methods.
Directory of Open Access Journals (Sweden)
Jones Douglas L
2006-01-01
Full Text Available An engineered artificial lateral-line system has been recently developed, consisting of a 16-element array of finely spaced MEMS hot-wire flow sensors. This represents a new class of underwater flow sensing instruments and necessitates the development of rapid, efficient, and robust signal processing algorithms. In this paper, we report on the development and implementation of a set of algorithms that assist in the localization and tracking of vibrational dipole sources underwater. Using these algorithms, accurate tracking of the trajectory of a moving dipole source has been demonstrated successfully.
Research of maneuvering target prediction and tracking technology based on IMM algorithm
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
Directory of Open Access Journals (Sweden)
S.A. Mohammadi
2011-10-01
Full Text Available Mean shift algorithms are among the most functional tracking methods which are accurate and havealmost simple computation. Different versions of this algorithm are developed which are differ in templateupdating and their window sizes. To measure the reliability and accuracy of these methods one shouldnormally rely on visual results or number of iteration. In this paper we introduce two new parameterswhich can be used to compare the algorithms especially when their results are close to each other.
Online Tracking Algorithms on GPUs for the P̅ANDA Experiment at FAIR
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.
An Efficient Lagrangean Relaxation-based Object Tracking Algorithm in Wireless Sensor Networks
Directory of Open Access Journals (Sweden)
Frank Yeong-Sung Lin
2010-08-01
Full Text Available 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.
Fuzzy Neural Network-Based Interacting Multiple Model for Multi-Node Target Tracking Algorithm
Directory of Open Access Journals (Sweden)
Baoliang Sun
2016-11-01
Full Text Available 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.
Artificial Neural Network In Maximum Power Point Tracking Algorithm Of Photovoltaic Systems
Directory of Open Access Journals (Sweden)
Modestas Pikutis
2014-05-01
Full Text Available Scientists are looking for ways to improve the efficiency of solar cells all the time. The efficiency of solar cells which are available to the general public is up to 20%. Part of the solar energy is unused and a capacity of solar power plant is significantly reduced – if slow controller or controller which cannot stay at maximum power point of solar modules is used. Various algorithms of maximum power point tracking were created, but mostly algorithms are slow or make mistakes. In the literature more and more oftenartificial neural networks (ANN in maximum power point tracking process are mentioned, in order to improve performance of the controller. Self-learner artificial neural network and IncCond algorithm were used for maximum power point tracking in created solar power plant model. The algorithm for control was created. Solar power plant model is implemented in Matlab/Simulink environment.
Directory of Open Access Journals (Sweden)
G.Mallikarjuna Rao
2014-09-01
Full Text Available In the present day real time applications of visual object tracking in surveillance, it has become extremely complex, time consuming and tricky to do the tracking when there are occlusions are present for small duration or for longer time and also when it is done in outdoor environments. In these conditions, the target to be tracked can be lost for few seconds and that should be tracked as soon as possible. As from the literature it is observed that particle filter can be able to track the target robustly in different kinds of background conditions, and it’s robust to partial occlusion. However, this tracking cannot recover from large proportion of occlusion and complete occlusion, to avoid this condition, we proposed two new algorithms (modified kalman and modified particle filter for fast tracking of objects in the presence of occlusions. We considered the complete occlusion of tracking object and the main objective is how fast the system is able to track the object after the occlusion is crossed. From the experimental results, it is observed that the proposed algorithms have shown good improvement in results compared to the traditional methods.
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.
The research on algorithms for optoelectronic tracking servo control systems
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.
Lane Tracking with Omnidirectional Cameras: Algorithms and Evaluation
Directory of Open Access Journals (Sweden)
Cheng ShinkoYuanhsien
2007-01-01
Full Text Available With a panoramic view of the scene, a single omnidirectional camera can monitor the 360-degree surround of the vehicle or monitor the interior and exterior of the vehicle at the same time. We investigate problems associated with integrating driver assistance functionalities that have been designed for rectilinear cameras with a single omnidirectional camera instead. Specifically, omnidirectional cameras have been shown effective in determining head gaze orientation from within a vehicle. We examine the issues involved in integrating lane tracking functions using the same omnidirectional camera, which provide a view of both the driver and the road ahead of the vehicle. We present analysis on the impact of the omnidirectional camera's reduced image resolution on lane tracking accuracy, as a consequence of gaining the expansive view. And to do so, we present Omni-VioLET, a modified implementation of the vision-based lane estimation and tracking system (VioLET, and conduct a systematic performance evaluation of both lane-trackers operating on monocular rectilinear images and omnidirectional images. We are able to show a performance comparison of the lane tracking from Omni-VioLET and Recti-VioLET with ground truth using images captured along the same freeway road in a specified course. The results are surprising: with 1/10th the number of pixels representing the same space and about 1/3rd the horizontal image resolution as a rectilinear image of the same road, the omnidirectional camera implementation results in only three times the amount the mean absolute error in tracking the left lane boundary position.
Lane Tracking with Omnidirectional Cameras: Algorithms and Evaluation
Directory of Open Access Journals (Sweden)
Shinko Yuanhsien Cheng
2007-09-01
Full Text Available With a panoramic view of the scene, a single omnidirectional camera can monitor the 360-degree surround of the vehicle or monitor the interior and exterior of the vehicle at the same time. We investigate problems associated with integrating driver assistance functionalities that have been designed for rectilinear cameras with a single omnidirectional camera instead. Specifically, omnidirectional cameras have been shown effective in determining head gaze orientation from within a vehicle. We examine the issues involved in integrating lane tracking functions using the same omnidirectional camera, which provide a view of both the driver and the road ahead of the vehicle. We present analysis on the impact of the omnidirectional camera's reduced image resolution on lane tracking accuracy, as a consequence of gaining the expansive view. And to do so, we present Omni-VioLET, a modified implementation of the vision-based lane estimation and tracking system (VioLET, and conduct a systematic performance evaluation of both lane-trackers operating on monocular rectilinear images and omnidirectional images. We are able to show a performance comparison of the lane tracking from Omni-VioLET and Recti-VioLET with ground truth using images captured along the same freeway road in a specified course. The results are surprising: with 1/10th the number of pixels representing the same space and about 1/3rd the horizontal image resolution as a rectilinear image of the same road, the omnidirectional camera implementation results in only three times the amount the mean absolute error in tracking the left lane boundary position.
Directory of Open Access Journals (Sweden)
Daniel H Rapoport
Full Text Available 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
An Improved Fast Compressive Tracking Algorithm Based on Online Random Forest Classifier
Directory of Open Access Journals (Sweden)
Xiong Jintao
2016-01-01
Full Text Available The fast compressive tracking (FCT algorithm is a simple and efficient algorithm, which is proposed in recent years. But, it is difficult to deal with the factors such as occlusion, appearance changes, pose variation, etc in processing. The reasons are that, Firstly, even if the naive Bayes classifier is fast in training, it is not robust concerning the noise. Secondly, the parameters are required to vary with the unique environment for accurate tracking. In this paper, we propose an improved fast compressive tracking algorithm based on online random forest (FCT-ORF for robust visual tracking. Firstly, we combine ideas with the adaptive compressive sensing theory regarding the weighted random projection to exploit both local and discriminative information of the object. The second reason is the online random forest classifier for online tracking which is demonstrated with more robust to the noise adaptively and high computational efficiency. The experimental results show that the algorithm we have proposed has a better performance in the field of occlusion, appearance changes, and pose variation than the fast compressive tracking algorithm’s contribution.
Feature tracking for automated volume of interest stabilization on 4D-OCT images
Laves, Max-Heinrich; Schoob, Andreas; Kahrs, Lüder A.; Pfeiffer, Tom; Huber, Robert; Ortmaier, Tobias
2017-03-01
A common representation of volumetric medical image data is the triplanar view (TV), in which the surgeon manually selects slices showing the anatomical structure of interest. In addition to common medical imaging such as MRI or computed tomography, recent advances in the field of optical coherence tomography (OCT) have enabled live processing and volumetric rendering of four-dimensional images of the human body. Due to the region of interest undergoing motion, it is challenging for the surgeon to simultaneously keep track of an object by continuously adjusting the TV to desired slices. To select these slices in subsequent frames automatically, it is necessary to track movements of the volume of interest (VOI). This has not been addressed with respect to 4DOCT images yet. Therefore, this paper evaluates motion tracking by applying state-of-the-art tracking schemes on maximum intensity projections (MIP) of 4D-OCT images. Estimated VOI location is used to conveniently show corresponding slices and to improve the MIPs by calculating thin-slab MIPs. Tracking performances are evaluated on an in-vivo sequence of human skin, captured at 26 volumes per second. Among investigated tracking schemes, our recently presented tracking scheme for soft tissue motion provides highest accuracy with an error of under 2.2 voxels for the first 80 volumes. Object tracking on 4D-OCT images enables its use for sub-epithelial tracking of microvessels for image-guidance.
Interacting with target tracking algorithms in a gaze-enhanced motion video analysis system
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.
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
Parametric analysis of architectural volumes through genetic algorithms
Directory of Open Access Journals (Sweden)
Pedro Salcedo Lagos
2015-03-01
Full Text Available During the last time, architectural design has developed partly due to new digital design techniques, which allow the generation of geometries based on the definition of initial parameters and the programming of formal relationship between them. Design processes based on these technologies allow to create shapes with the capacity to modify and adapt to multiple constrains or specific evaluation criteria, which raises the problem of identifying the best architectural solution. Several experiences have set up the utilization of genetic algorithm to face this problem. This paper demonstrates the possibility to implement a parametric analysis of architectural volumes with genetic algorithm, in order to combine functional, environmental and structural requirements, with an effective search method to select a variety of proper solutions through digital technologies.
A Volume Rendering Algorithm for Sequential 2D Medical Images
Institute of Scientific and Technical Information of China (English)
吕忆松; 陈亚珠
2002-01-01
Volume rendering of 3D data sets composed of sequential 2D medical images has become an important branch in image processing and computer graphics.To help physicians fully understand deep-seated human organs and focuses(e.g.a tumour)as 3D structures.in this paper,we present a modified volume rendering algorithm to render volumetric data,Using this method.the projection images of structures of interest from different viewing directions can be obtained satisfactorily.By rotating the light source and the observer eyepoint,this method avoids rotates the whole volumetric data in main memory and thus reduces computational complexity and rendering time.Experiments on CT images suggest that the proposed method is useful and efficient for rendering 3D data sets.
Quimp3, an automated pseudopod-tracking algorithm
Bosgraaf, Leonard; Van Haastert, Peter J. M.
2010-01-01
To understand movement of amoeboid cells we have developed an information tool that automatically detects protrusions of moving cells. The algorithm uses digitized cell recordings at a speed of similar to 1 image per second that are analyzed in three steps. In the first part, the outline of a cell
Robust Face Location and Tracking Using Optical Flow and Genetic Algorithms
Institute of Scientific and Technical Information of China (English)
WANG Yanjiang; YUAN Baozong
2001-01-01
This paper presents a new and robustapproach to the detection, localization and tracking ofa human face in image sequences. First, a fast algo-rithm based on the neighbor-point-reliability is pro-posed to calculate the optical flow, which is used toextract the motion region. Then the hair and thehead knowledges are used to locate the face area. Forface tracking, a new genetic algorithms-based dynamictemplate-matching method is applied to search thenew position of the face in each new video frame. Ex-perimental results show that the proposed face track-ing method is fast and robust to illumination, faceposes, facial expressions and image distractors suchas facial occlusion by hands.
Tracking Positioning Algorithm for Direction of Arrival Based on Direction Lock Loop
Directory of Open Access Journals (Sweden)
Xiu-Zhi Cheng
2015-06-01
Full Text Available In order to solve the problem of poor real-time performance, low accuracy and high computational complexity in the traditional process of locating and tracking of Direction of Arrival (DOA of moving targets, this paper proposes a DOA algorithm based on the Direction Lock Loop (DILL which adopts Lock Loop structure to realize the estimation and location of DOA and can adjust the direction automatically along with the changes of a signal’s angular variation to track the position of the signal. Meanwhile, to reduce the influence of nonlinearity and noise on its performance, the UKF filter is designed for eliminating interference of the estimated target signal to improve accuracy of the signal tracking and stability of the system. Simulation results prove that the algorithm can not only get a high resolution DOA estimate signal, but can also locate and track multiple mobile targets effectively with enhanced accuracy, efficiency and stability.
Decision-Directed Frequency Tracking Algorithm for OFDM System in Fast Fading Environments
Institute of Scientific and Technical Information of China (English)
HE Bo; LI Jun; LIN Jia-ru; WU Wei-ling
2005-01-01
This paper analyzed the structure of Orthogonal Frequency Division Multiplex (OFDM) system and presented a new Carrier Frequency Offset (CFO) tracking algorithm, which depends on comparability between the decision data and the original data to correct carrier frequency offset. Therefore it is robust during the normal communization process since the Bit Error Rate (BER) of the decision data is low. We can utilize pilot data in time domain for channel estimation to track CFO without reducing system efficient and to enhance the tracking scope largely. Simulation results denote the presented algorithm can track the frequency offset and control it under ±1% using only 1 frame if the original frequency offset is within ±8%.
GPU-Based Tracking Algorithms for the ATLAS High-Level Trigger
Emeliyanov, D; The ATLAS collaboration
2012-01-01
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.
Directory of Open Access Journals (Sweden)
Jharna Majumdar
2002-07-01
Full Text Available "Automatic detection and tracking of interesting targets from a sequence of images obtained from a reconnaissance platform is an interesting area of research for defence-related applications. Image registration is the basic step used in target tracking application. The paper briefly reviews some of the image registration algorithms, analyse their performance using a suitable image processing hardware, and selects the most suitable algorithm for a real-time target tracking application using cubic-spline model and spline model Kalman filter for the prediction of an occluded target. The algorithms developed are implemented in a ground-based image exploitation system (GIES developed at the Aeronautical Development Establishment for unmanned aerial vehicle application, and the results presented for the images obtained during actual flight trial.
A hand tracking algorithm with particle filter and improved GVF snake model
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.
Multi-User Identification-Based Eye-Tracking Algorithm Using Position Estimation.
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.
3D head pose estimation and tracking using particle filtering and ICP algorithm
Ben Ghorbel, Mahdi
2010-01-01
This paper addresses the issue of 3D head pose estimation and tracking. Existing approaches generally need huge database, training procedure, manual initialization or use face feature extraction manually extracted. We propose a framework for estimating the 3D head pose in its fine level and tracking it continuously across multiple Degrees of Freedom (DOF) based on ICP and particle filtering. We propose to approach the problem, using 3D computational techniques, by aligning a face model to the 3D dense estimation computed by a stereo vision method, and propose a particle filter algorithm to refine and track the posteriori estimate of the position of the face. This work comes with two contributions: the first concerns the alignment part where we propose an extended ICP algorithm using an anisotropic scale transformation. The second contribution concerns the tracking part. We propose the use of the particle filtering algorithm and propose to constrain the search space using ICP algorithm in the propagation step. The results show that the system is able to fit and track the head properly, and keeps accurate the results on new individuals without a manual adaptation or training. © Springer-Verlag Berlin Heidelberg 2010.
A two-stage visual tracking algorithm using dual-template
Directory of Open Access Journals (Sweden)
Yu Xia
2016-10-01
Full Text Available Template matching and updates are crucial steps in visual object tracking. In this article, we propose a two-stage object tracking algorithm using a dual-template. By design, the initial state of a target can be estimated using a prior fixed template at the first stage with a particle-filter-based tracking framework. The use of prior templates maintains the stability of an object tracking algorithm, because it consists of invariant and important features. In the second step, a mean shift is used to gain the optimal location of the object with the stage update template. The stage template improves the ability of target recognition using a classified update method. The complementary of dual-template improves the quality of template matching and the performance of object tracking. Experimental results demonstrate that the proposed algorithm improves the tracking performance in terms of accuracy and robustness, and it exhibits good results in the presence of deformation, noise and occlusion.
Algorithm for Multi-laser-target Tracking Based on Clustering Fusion
Institute of Scientific and Technical Information of China (English)
ZHANG Li-qun; LI Yan-jun; ZHANG Ke
2007-01-01
Multi-laser-target tracking is an important subject in the field of signal processing of laser warners. A clustering method is applied to the measurement of laser warner, and the space-time fusion for measurements in the same cluster is accomplished. Real-time tracking of multi-laser-target and real-time picking of multi-laser-signal are introduced using data fusion of the measurements. A prototype device of the algorithm is built up. The results of experiments show that the algorithm is very effective.
Islanding Detection for Microgrid Based on Frequency Tracking Using Extended Kalman Filter Algorithm
Directory of Open Access Journals (Sweden)
Bin Li
2014-01-01
Full Text Available Islanding detection is essential for secure and reliable operation of microgrids. Considering the relationship between the power generation and the load in microgrids, frequency may vary with time when islanding occurs. As a common approach, frequency measurement is widely used to detect islanding condition. In this paper, a novel frequency calculation algorithm based on extended Kalman filter was proposed to track dynamic frequency of the microgrid. Taylor series expansion was introduced to solve nonlinear state equations. In addition, a typical microgrid model was built using MATLAB/SIMULINK. Simulation results demonstrated that the proposed algorithm achieved great stability and strong robustness in of tracking dynamic frequency.
An Airborne Radar Clutter Tracking Algorithm Based on Multifractal and Fuzzy C-Mean Cluster
Institute of Scientific and Technical Information of China (English)
Wei Zhang; Sheng-Lin Yu; Gong Zhang
2007-01-01
For an airborne lookdown radar, clutter power often changes dynamically about 80 dB with wide distributions as the platform moves. Therefore, clutter tracking techniques are required to guide the selection of const false alarm rate (CFAR) schemes. In this work, clutter tracking is done in image domain and an algorithm combining multifractal and fuzzy C-mean (FCM) cluster is proposed. The clutter with large dynamic distributions in power density is converted to steady distributions of multifractal exponents by the multifractal transformation with the optimum moment. Then, later, the main lobe and side lobe are tracked from the multifractal exponents by FCM clustering method.
Comparison of two detection algorithms for spot tracking in fluorescence microscopy images
CSIR Research Space (South Africa)
Mabaso, M
2014-11-01
Full Text Available for spot tracking in fluorescence microscopy images Matsilele Mabaso∗, Daniel Withey‡, Bhekisipho Twala† ∗ ‡MDS(MIAS) Council for Scientific and Industrial Research Pretoria, South Africa, Email: ∗MMabaso@csir.co.za †Department of Electrical Engineering.... The quantitative comparative results demonstrated the importance of spot detection in tracking contexts. I. INTRODUCTION In recent years, the field of fluorescence microscopy has been improved and automated, and a large volume of image data are being generated...
Salvadori, A.; Fantoni, F.
2016-10-01
The present work frames the problem of three-dimensional quasi-static crack propagation in brittle materials into the theory of standard dissipative processes. Variational formulations are stated. They characterize the three dimensional crack front "quasi-static velocity" as minimizer of constrained quadratic functionals. An implicit in time crack tracking algorithm that computationally handles the constraint via the penalty method algorithm is introduced and proof of concept is provided.
A new fast algorithm for multitarget tracking in dense clutter
Institute of Scientific and Technical Information of China (English)
Weihua QIN; Fei HU; Chaoyin QIN
2005-01-01
A fast joint probabilistic data association (FJPDA) algorithm is proposed in this paper. Cluster probability matrix is approximately calculated by a new method, whose elements βli(K) can be taken as evaluation functions. According to values of βti(K), N events with larger joint probabilities can be searched out as the events with guiding joint probabilities, thus, the number of searching nodes will be greatly reduced. As a result, this method effectively reduces the calculation load and makes it possible to be realized on real-time. Theoretical analysis and Monte Carlo simulation results show that this method is efficient.
Institute of Scientific and Technical Information of China (English)
Zhang Chun; Fei Shu-Min; Zhou Xing-Peng
2012-01-01
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 crror,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.
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.
Registration of clinical volumes to beams-eye-view images for real-time tracking
Energy Technology Data Exchange (ETDEWEB)
Bryant, Jonathan H.; Rottmann, Joerg; Lewis, John H.; Mishra, Pankaj; Berbeco, Ross I., E-mail: rberbeco@lroc.harvard.edu [Department of Radiation Oncology, Brigham and Women’s Hospital, Dana-Farber Cancer Institute and Harvard Medical School, Boston, Massachusetts 02115 (United States); Keall, Paul J. [Radiation Physics Laboratory, Sydney Medical School, University of Sydney, Sydney, New South Wales 2006 (Australia)
2014-12-15
Purpose: The authors combine the registration of 2D beam’s eye view (BEV) images and 3D planning computed tomography (CT) images, with relative, markerless tumor tracking to provide automatic absolute tracking of physician defined volumes such as the gross tumor volume (GTV). Methods: During treatment of lung SBRT cases, BEV images were continuously acquired with an electronic portal imaging device (EPID) operating in cine mode. For absolute registration of physician-defined volumes, an intensity based 2D/3D registration to the planning CT was performed using the end-of-exhale (EoE) phase of the four dimensional computed tomography (4DCT). The volume was converted from Hounsfield units into electron density by a calibration curve and digitally reconstructed radiographs (DRRs) were generated for each beam geometry. Using normalized cross correlation between the DRR and an EoE BEV image, the best in-plane rigid transformation was found. The transformation was applied to physician-defined contours in the planning CT, mapping them into the EPID image domain. A robust multiregion method of relative markerless lung tumor tracking quantified deviations from the EoE position. Results: The success of 2D/3D registration was demonstrated at the EoE breathing phase. By registering at this phase and then employing a separate technique for relative tracking, the authors are able to successfully track target volumes in the BEV images throughout the entire treatment delivery. Conclusions: Through the combination of EPID/4DCT registration and relative tracking, a necessary step toward the clinical implementation of BEV tracking has been completed. The knowledge of tumor volumes relative to the treatment field is important for future applications like real-time motion management, adaptive radiotherapy, and delivered dose calculations.
Through-Wall Multiple Targets Vital Signs Tracking Based on VMD Algorithm
Directory of Open Access Journals (Sweden)
Jiaming Yan
2016-08-01
Full Text Available 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.
A stand-alone track reconstruction algorithm for the scintillating fibre tracker at the LHCb upgrade
Quagliani, Renato
2017-01-01
The LHCb upgrade detector project foresees the presence of a scintillating fiber tracker (SciFi) to be used during the LHC Run III, starting in 2020. The instantaneous luminosity will be increased up to $2\\times10^{33}$, five times larger than in Run II and a full software event reconstruction will be performed at the full bunch crossing rate by the trigger. The new running conditions, and the tighter timing constraints in the software trigger, represent a big challenge for track reconstruction. This poster presents the design and performance of a novel algorithm that has been developed to reconstruct track segments using solely hits from the SciFi. This algorithm is crucial for the reconstruction of tracks originating from long-lived particles such as $K_{S}^{0}$ and $\\Lambda$ and allows to greatly enhance the physics potential and capabilities of the LHCb upgrade when compared to its previous implementation.
Weak and Dynamic GNSS Signal Tracking Strategies for Flight Missions in the Space Service Volume
Jing, Shuai; Zhan, Xingqun; Liu, Baoyu; Chen, Maolin
2016-01-01
Weak-signal and high-dynamics are of two primary concerns of space navigation using GNSS (Global Navigation Satellite System) in the space service volume (SSV). The paper firstly defines a reference assumption third-order phase-locked loop (PLL) as the baseline of an onboard GNSS receiver, and proves the incompetence of this conventional architecture. Then an adaptive four-state Kalman filter (KF)-based algorithm is introduced to realize the optimization of loop noise bandwidth, which can adaptively regulate its filter gain according to the received signal power and line-of-sight (LOS) dynamics. To overcome the matter of losing lock in weak-signal and high-dynamic environments, an open loop tracking strategy aided by an inertial navigation system (INS) is recommended, and the traditional maximum likelihood estimation (MLE) method is modified in a non-coherent way by reconstructing the likelihood cost function. Furthermore, a typical mission with combined orbital maneuvering and non-maneuvering arcs is taken as a destination object to test the two proposed strategies. Finally, the experiment based on computer simulation identifies the effectiveness of an adaptive four-state KF-based strategy under non-maneuvering conditions and the virtue of INS-assisted methods under maneuvering conditions. PMID:27598164
Weak and Dynamic GNSS Signal Tracking Strategies for Flight Missions in the Space Service Volume.
Jing, Shuai; Zhan, Xingqun; Liu, Baoyu; Chen, Maolin
2016-09-02
Weak-signal and high-dynamics are of two primary concerns of space navigation using GNSS (Global Navigation Satellite System) in the space service volume (SSV). The paper firstly defines a reference assumption third-order phase-locked loop (PLL) as the baseline of an onboard GNSS receiver, and proves the incompetence of this conventional architecture. Then an adaptive four-state Kalman filter (KF)-based algorithm is introduced to realize the optimization of loop noise bandwidth, which can adaptively regulate its filter gain according to the received signal power and line-of-sight (LOS) dynamics. To overcome the matter of losing lock in weak-signal and high-dynamic environments, an open loop tracking strategy aided by an inertial navigation system (INS) is recommended, and the traditional maximum likelihood estimation (MLE) method is modified in a non-coherent way by reconstructing the likelihood cost function. Furthermore, a typical mission with combined orbital maneuvering and non-maneuvering arcs is taken as a destination object to test the two proposed strategies. Finally, the experiment based on computer simulation identifies the effectiveness of an adaptive four-state KF-based strategy under non-maneuvering conditions and the virtue of INS-assisted methods under maneuvering conditions.
Weak and Dynamic GNSS Signal Tracking Strategies for Flight Missions in the Space Service Volume
Directory of Open Access Journals (Sweden)
Shuai Jing
2016-09-01
Full Text Available Weak-signal and high-dynamics are of two primary concerns of space navigation using GNSS (Global Navigation Satellite System in the space service volume (SSV. The paper firstly defines a reference assumption third-order phase-locked loop (PLL as the baseline of an onboard GNSS receiver, and proves the incompetence of this conventional architecture. Then an adaptive four-state Kalman filter (KF-based algorithm is introduced to realize the optimization of loop noise bandwidth, which can adaptively regulate its filter gain according to the received signal power and line-of-sight (LOS dynamics. To overcome the matter of losing lock in weak-signal and high-dynamic environments, an open loop tracking strategy aided by an inertial navigation system (INS is recommended, and the traditional maximum likelihood estimation (MLE method is modified in a non-coherent way by reconstructing the likelihood cost function. Furthermore, a typical mission with combined orbital maneuvering and non-maneuvering arcs is taken as a destination object to test the two proposed strategies. Finally, the experiment based on computer simulation identifies the effectiveness of an adaptive four-state KF-based strategy under non-maneuvering conditions and the virtue of INS-assisted methods under maneuvering conditions.
Optimality analysis of one-step OOSM filtering algorithms in target tracking
Institute of Scientific and Technical Information of China (English)
ZHOU WenHui; LI Lin; CHEN GuoHai; YU AnXi
2007-01-01
In centralized multisensor tracking systems, there are out-of-sequence measurements (OOSMs) frequently arising due to different time delays in communication links and varying pre-processing times at the sensor. Such OOSM arrival can induce the "negative-time measurement update" problem, which is quite common in real multisensor tracking systems. The A1 optimal update algorithm with OOSM is presented by Bar-Shalom for one-step case. However, this paper proves that the optimality of A1 algorithm is lost in direct discrete-time model (DDM) of the process noise, it holds true only in discretized continuous-time model (DCM). One better OOSM filtering algorithm for DDM case is presented. Also, another new optimal OOSM filtering algorithm, which is independent of the discrete time model of the process noise, is presented here. The performance of the two new algorithms is compared with that of A1 algorithm by Monte Carlo simulations. The effectiveness and correctness of the two proposed algorithms are validated by analysis and simulation results.
A GPU implementation of a track-repeating algorithm for proton radiotherapy dose calculations
Yepes, Pablo P; Taddei, Phillip J
2010-01-01
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 anatomic 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 (GPU) rather than a central processing unit architecture. This implementation reproduces the full Monte Carlo and CPU-based track-repeating dose calculations within 2%, w...
Real Time Optima Tracking Using Harvesting Models of the Genetic Algorithm
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.
ISS-based robust adaptive fuzzy algorithm for maintaining a ship's track
Institute of Scientific and Technical Information of China (English)
无
2007-01-01
This paper focuses on the problem of linear track keeping for marine surface vessels.The influence exerted by sea currents on the kinematic equation of ships is considered first.The input-to-state stability (ISS) theory used to verify the system is input-to-state stable.Combining the Nussbaum gain with backstepping techniques, a robust adaptive fuzzy algorithm is presented by employing fuzzy systems as an approximator for unknown nonlinearities in the system.It is proved that the proposed algorithm that guarantees all signals in the closed-loop system are ultimately bounded.Consequently, a ship's linear track-keeping control can be implemented.Simulation results using Dalian Maritime University's ocean-going training ship 'YULONG' are presented to validate the effectiveness of the proposed algorithm.
Design and implementation of a vision-based hovering and feature tracking algorithm for a quadrotor
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.
Gagnon, Louis-Guillaume; The ATLAS collaboration
2017-01-01
ATLAS track reconstruction software is continuously evolving to match the demands from the increasing instantaneous luminosity of the LHC, as well as the increased center-of-mass energy. These conditions result in a higher abundance of events with dense track environments, such the core of jets or boosted tau leptons undergoing three-prong decays. These environments are characterised by charged particle separations on the order of the ATLAS inner detector sensor dimensions and are created by the decay of boosted objects. Significant upgrades were made to the track reconstruction software to cope with the expected conditions during LHC Run~2. In particular, new algorithms targeting dense environments were developed. These changes lead to a substantial reduction of reconstruction time while at the same time improving physics performance. The employed methods are presented and physics performance studies are shown, including a measurement of the fraction of lost tracks in jets with high transverse momentum.
Multiple Objects Tracking Using CAMShift Algorithm and Implementation of Trip Wire
Directory of Open Access Journals (Sweden)
Shirish Halbe
2013-05-01
Full Text Available In this paper we represent Security application which is developed using concepts of Video Analytics. User can draw Trip wire on video stream with help of Mouse Callback events. Using this application user can restrict any area of total video scene. Direction selection for tripping is also a choice of a user. If any undesired moving object cross this drawn trip wire then motion of this moving object is getting detected and also tracked. If object crosses trip wire in the same direction as that of user selected then Alarm Indication will appear on that moving object. OpenCV library functions are used for motion detection and motion tracking. CAMShift algorithm is implemented for tracking. An experimental result shows Motion detection, Motion Tracking and drawn trip wire on video.
Target-tracking and identity management algorithms for air traffic surveillance
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
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
A Robust Vision-based Runway Detection and Tracking Algorithm for Automatic UAV Landing
Abu Jbara, Khaled F.
2015-05-01
This work presents a novel real-time algorithm for runway detection and tracking applied to the automatic takeoff and landing of Unmanned Aerial Vehicles (UAVs). The algorithm is based on a combination of segmentation based region competition and the minimization of a specific energy function to detect and identify the runway edges from streaming video data. The resulting video-based runway position estimates are updated using a Kalman Filter, which can integrate other sensory information such as position and attitude angle estimates to allow a more robust tracking of the runway under turbulence. We illustrate the performance of the proposed lane detection and tracking scheme on various experimental UAV flights conducted by the Saudi Aerospace Research Center. Results show an accurate tracking of the runway edges during the landing phase under various lighting conditions. Also, it suggests that such positional estimates would greatly improve the positional accuracy of the UAV during takeoff and landing phases. The robustness of the proposed algorithm is further validated using Hardware in the Loop simulations with diverse takeoff and landing videos generated using a commercial flight simulator.
An evaluation of the potential of GPUs to accelerate tracking algorithms for the ATLAS trigger
Baines, JTM; The ATLAS collaboration; Emeliyanov, D; Howard, JR; Kama, S; Washbrook, AJ; Wynne, BM
2014-01-01
The potential of GPUs has been evaluated as a possible way to accelerate trigger algorithms for the ATLAS experiment located at the Large Hadron Collider (LHC). During LHC Run-1 ATLAS employed a three-level trigger system to progressively reduce the LHC collision rate of 20 MHz to a storage rate of about 600 Hz for offline processing. Reconstruction of charged particles trajectories through the Inner Detector (ID) was performed at the second (L2) and third (EF) trigger levels. The ID contains pixel, silicon strip (SCT) and straw-tube technologies. Prior to tracking, data-preparation algorithms processed the ID raw data producing measurements of the track position at each detector layer. The data-preparation and tracking consumed almost three-quarters of the total L2 CPU resources during 2012 data-taking. Detailed performance studies of a CUDA™ implementation of the L2 pixel and SCT data-preparation and tracking algorithms running on a Nvidia® Tesla C2050 GPU have shown a speed-up by a factor of 12 for the ...
A Feedback-Based Algorithm for Motion Analysis with Application to Object Tracking
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P. S. Sastry
2007-01-01
Full Text Available We present a motion detection algorithm which detects direction of motion at sufficient number of points and thus segregates the edge image into clusters of coherently moving points. Unlike most algorithms for motion analysis, we do not estimate magnitude of velocity vectors or obtain dense motion maps. The motivation is that motion direction information at a number of points seems to be sufficient to evoke perception of motion and hence should be useful in many image processing tasks requiring motion analysis. The algorithm essentially updates the motion at previous time using the current image frame as input in a dynamic fashion. One of the novel features of the algorithm is the use of some feedback mechanism for evidence segregation. This kind of motion analysis can identify regions in the image that are moving together coherently, and such information could be sufficient for many applications that utilize motion such as segmentation, compression, and tracking. We present an algorithm for tracking objects using our motion information to demonstrate the potential of this motion detection algorithm.
A Feedback-Based Algorithm for Motion Analysis with Application to Object Tracking
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Shah Shesha
2007-01-01
Full Text Available We present a motion detection algorithm which detects direction of motion at sufficient number of points and thus segregates the edge image into clusters of coherently moving points. Unlike most algorithms for motion analysis, we do not estimate magnitude of velocity vectors or obtain dense motion maps. The motivation is that motion direction information at a number of points seems to be sufficient to evoke perception of motion and hence should be useful in many image processing tasks requiring motion analysis. The algorithm essentially updates the motion at previous time using the current image frame as input in a dynamic fashion. One of the novel features of the algorithm is the use of some feedback mechanism for evidence segregation. This kind of motion analysis can identify regions in the image that are moving together coherently, and such information could be sufficient for many applications that utilize motion such as segmentation, compression, and tracking. We present an algorithm for tracking objects using our motion information to demonstrate the potential of this motion detection algorithm.
Directory of Open Access Journals (Sweden)
Wenhui Hou
2016-01-01
Full Text Available In order to extract the maximum power from PV system, the maximum power point tracking (MPPT technology has always been applied in PV system. At present, various MPPT control methods have been presented. The perturb and observe (P&O and conductance increment methods are the most popular and widely used under the constant irradiance. However, these methods exhibit fluctuations among the maximum power point (MPP. In addition, the changes of the environmental parameters, such as cloud cover, plant shelter, and the building block, will lead to the radiation change and then have a direct effect on the location of MPP. In this paper, a feasible MPPT method is proposed to adapt to the variation of the irradiance. This work applies the glowworm swarm optimization (GSO algorithm to determine the optimal value of a reference voltage in the PV system. The performance of the proposed GSO algorithm is evaluated by comparing it with the conventional P&O method in terms of tracking speed and accuracy by utilizing MATLAB/SIMULINK. The simulation results demonstrate that the tracking capability of the GSO algorithm is superior to that of the traditional P&O algorithm, particularly under low radiance and sudden mutation irradiance conditions.
Fuzzy Tracking and Control Algorithm for an SSVEP-Based BCI System
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Yeou-Jiunn Chen
2016-09-01
Full Text Available Subjects with amyotrophic lateral sclerosis (ALS consistently experience decreasing quality of life because of this distinctive disease. Thus, a practical brain-computer interface (BCI application can effectively help subjects with ALS to participate in communication or entertainment. In this study, a fuzzy tracking and control algorithm is proposed for developing a BCI remote control system. To represent the characteristics of the measured electroencephalography (EEG signals after visual stimulation, a fast Fourier transform is applied to extract the EEG features. A self-developed fuzzy tracking algorithm quickly traces the changes of EEG signals. The accuracy and stability of a BCI system can be greatly improved by using a fuzzy control algorithm. Fifteen subjects were asked to attend a performance test of this BCI system. The canonical correlation analysis (CCA was adopted to compare the proposed approach, and the average recognition rates are 96.97% and 94.49% for proposed approach and CCA, respectively. The experimental results showed that the proposed approach is preferable to CCA. Overall, the proposed fuzzy tracking and control algorithm applied in the BCI system can profoundly help subjects with ALS to control air swimmer drone vehicles for entertainment purposes.
The small-voxel tracking algorithm for simulating chemical reactions among diffusing molecules
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
Dettmer, J.; Quijano, J. E.; Dosso, S. E.; Holland, C. W.; Mandolesi, E.
2016-12-01
Geophysical seabed properties are important for the detection and classification of unexploded ordnance. However, current surveying methods such as vertical seismic profiling, coring, or inversion are of limited use when surveying large areas with high spatial sampling density. We consider surveys based on a source and receiver array towed by an autonomous vehicle which produce large volumes of seabed reflectivity data that contain unprecedented and detailed seabed information. The data are analyzed with a particle filter, which requires efficient reflection-coefficient computation, efficient inversion algorithms and efficient use of computer resources. The filter quantifies information content of multiple sequential data sets by considering results from previous data along the survey track to inform the importance sampling at the current point. Challenges arise from environmental changes along the track where the number of sediment layers and their properties change. This is addressed by a trans-dimensional model in the filter which allows layering complexity to change along a track. Efficiency is improved by likelihood tempering of various particle subsets and including exchange moves (parallel tempering). The filter is implemented on a hybrid computer that combines central processing units (CPUs) and graphics processing units (GPUs) to exploit three levels of parallelism: (1) fine-grained parallel computation of spherical reflection coefficients with a GPU implementation of Levin integration; (2) updating particles by concurrent CPU processes which exchange information using automatic load balancing (coarse grained parallelism); (3) overlapping CPU-GPU communication (a major bottleneck) with GPU computation by staggering CPU access to the multiple GPUs. The algorithm is applied to spherical reflection coefficients for data sets along a 14-km track on the Malta Plateau, Mediterranean Sea. We demonstrate substantial efficiency gains over previous methods. [This
The Ways of Fuzzy Control Algorithms Using for Harvesting Machines Tracking
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L. Tóth
2013-09-01
Full Text Available This contribution is oriented to ways of a fuzzy regulation using for machine tracking of the harvest machines. The main aim of this work was to practice verify and evaluate of functionality of control fuzzy algorithms for an Ackerman’s chassis which are generally used in agriculture machines for the crops harvesting. Design of the fuzzy control algorithm was focused to the wall following algorithm and obstacle avoidance. To achieve of the reliable results was made the real model of vehicle with Ackerman’s chassis type, which was controlled by PC with using development board Stellaris LM3S8962 based on ARM processor. Fuzzy control algorithms were developed in LabView application. Deviations were up to 0.2 m, which can be reduced to 0.1 m by hardware changing.
Efficient Parallel Algorithm for Statistical Ion Track Simulations in Crystalline Materials
Jeon, Byoungseon
2008-01-01
We present an efficient parallel algorithm for statistical Molecular Dynamics simulations of ion tracks in solids. The method is based on the Rare Event Enhanced Domain following Molecular Dynamics (REED-MD) algorithm, which has been successfully applied to studies of, e.g., ion implantation into crystalline semiconductor wafers. We discuss the strategies for parallelizing the method, and we settle on a host-client type polling scheme in which a multiple of asynchronous processors are continuously fed to the host, which, in turn, distributes the resulting feed-back information to the clients. This real-time feed-back consists of, e.g., cumulative damage information or statistics updates necessary for the cloning in the rare event algorithm. We finally demonstrate the algorithm for radiation effects in a nuclear oxide fuel, and we show the balanced parallel approach with high parallel efficiency in multiple processor configurations.
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Wei Zhu
2016-06-01
Full Text Available In order to improve the tracking accuracy, model estimation accuracy and quick response of multiple model maneuvering target tracking, the interacting multiple models five degree cubature Kalman filter (IMM5CKF is proposed in this paper. In the proposed algorithm, the interacting multiple models (IMM algorithm processes all the models through a Markov Chain to simultaneously enhance the model tracking accuracy of target tracking. Then a five degree cubature Kalman filter (5CKF evaluates the surface integral by a higher but deterministic odd ordered spherical cubature rule to improve the tracking accuracy and the model switch sensitivity of the IMM algorithm. Finally, the simulation results demonstrate that the proposed algorithm exhibits quick and smooth switching when disposing different maneuver models, and it also performs better than the interacting multiple models cubature Kalman filter (IMMCKF, interacting multiple models unscented Kalman filter (IMMUKF, 5CKF and the optimal mode transition matrix IMM (OMTM-IMM.
Zhu, Wei; Wang, Wei; Yuan, Gannan
2016-06-01
In order to improve the tracking accuracy, model estimation accuracy and quick response of multiple model maneuvering target tracking, the interacting multiple models five degree cubature Kalman filter (IMM5CKF) is proposed in this paper. In the proposed algorithm, the interacting multiple models (IMM) algorithm processes all the models through a Markov Chain to simultaneously enhance the model tracking accuracy of target tracking. Then a five degree cubature Kalman filter (5CKF) evaluates the surface integral by a higher but deterministic odd ordered spherical cubature rule to improve the tracking accuracy and the model switch sensitivity of the IMM algorithm. Finally, the simulation results demonstrate that the proposed algorithm exhibits quick and smooth switching when disposing different maneuver models, and it also performs better than the interacting multiple models cubature Kalman filter (IMMCKF), interacting multiple models unscented Kalman filter (IMMUKF), 5CKF and the optimal mode transition matrix IMM (OMTM-IMM).
Andrzejewska, Magdalena; Stolinska, Anna; Blasiak, Wladyslaw; Peczkowski, Pawel; Rosiek, Roman; Rozek, Bozena; Sajka, Miroslawa; Wcislo, Dariusz
2016-01-01
The results of qualitative and quantitative investigations conducted with individuals who learned algorithms in school are presented in this article. In these investigations, eye-tracking technology was used to follow the process of solving algorithmic problems. The algorithmic problems were presented in two comparable variants: in a pseudocode…
Andrzejewska, Magdalena; Stolinska, Anna; Blasiak, Wladyslaw; Peczkowski, Pawel; Rosiek, Roman; Rozek, Bozena; Sajka, Miroslawa; Wcislo, Dariusz
2016-01-01
The results of qualitative and quantitative investigations conducted with individuals who learned algorithms in school are presented in this article. In these investigations, eye-tracking technology was used to follow the process of solving algorithmic problems. The algorithmic problems were presented in two comparable variants: in a pseudocode…
TRACKING THE POSITION OF MULTIPLE HUMAN GESTURES USING CONTOUR MAPPING ALGORITHM
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T. S. Arulananth
2014-01-01
Full Text Available This study relates to a method for determining the position variation (for example a moving object, facial gesture tracking using markers. The movement is determined based on the periodic frames captured using a camera. The experimental results show that this algorithm can accurately segment human movements from complex background and can greatly reduce the computational workload with less storage memory, good robustness and improved accuracy. Thus, this algorithm can be pragmatically applied to video surveillance, motion assisted device control for critically disabled persons, Man Machine Interface, humanoid applications.
Study of cluster reconstruction and track fitting algorithms for CGEM-IT at BESIII
Guo, Yue; Ju, Xu-Dong; Wu, Ling-Hui; Xiu, Qing-Lei; Wang, Hai-Xia; Dong, Ming-Yi; Hu, Jing-Ran; Li, Wei-Dong; Li, Wei-Guo; Liu, Huai-Min; Ou-Yang, Qun; Shen, Xiao-Yan; Yuan, Ye; Zhang, Yao
2015-01-01
Considering the aging effects of existing Inner Drift Chamber (IDC) of BES\\uppercase\\expandafter{\\romannumeral3}, a GEM based inner tracker is proposed to be designed and constructed as an upgrade candidate for IDC. This paper introduces a full simulation package of CGEM-IT with a simplified digitization model, describes the development of the softwares for cluster reconstruction and track fitting algorithm based on Kalman filter method for CGEM-IT. Preliminary results from the reconstruction algorithms are obtained using a Monte Carlo sample of single muon events in CGEM-IT.
GPU-Based Tracking Algorithms for the ATLAS High-Level Trigger
Emeliyanov, D; The ATLAS collaboration
2012-01-01
GPU-accelerated event processing is one of the possible options for the ATLAS High-Level Trigger (HLT) upgrade for higher LHC luminosity. This poster presents data preparation and track finding algorithms specifically designed to run on a GPU using a “client-server” solution for hybrid CPU/GPU event processing and integration of the GPU algorithms into existing ATLAS HLT software. The resulting speed-up of event processing times obtained with high-luminosity simulated data is presented and discussed.
Belief Consensus Algorithms for Distributed Target Tracking in Wireless Sensor Networks
Savic, Vladimir; Zazo, Santiago
2012-01-01
In distributed target tracking in wireless sensor networks (WSN), agreement on the target state is usually achieved by the construction and maintenance of a communication path. Such an approach lack robustness to failures, and is not applicable to asynchronous networks. Recently, methods have been proposed that can solve these problems using consensus algorithms. However, these methods suffer from at least one of the following problems: i) they do not use fastest consensus methods, and ii) they cannot handle all parametric and nonparametric likelihood functions. In this paper, we propose a general framework for target tracking using distributed particle filtering (DPF) based on three asynchronous belief consensus (BC) algorithms: standard belief consensus (SBC), broadcast gossip (BG), and belief propagation (BP). Since DPF can be also solved (without consensus) by exchanging the observed data, we determine under which conditions BC-based methods are preferred. Finally, we perform extensive simulations to anal...
Experiments of two pupil lateral motion tracking algorithms using a Shack-Hartmann sensor
Dai, Xiaolin; Hippler, Stefan; Gendron, Eric
2017-01-01
Pupil stability is one of the factors which limit the performance and operational stability of adaptive optics (AO) systems. This paper analyses two pupil-tracking methods to measure the lateral pupil shift: the first one utilizes the fluxes in all outer edge sub-apertures of a Shack-Hartmann sensor and the second one utilizes the real-time interaction matrix used in an AO system. Experiments with 9×9 Shack-Hartmann sensor are conducted to verify both pupil-tracking algorithms. The results show that both algorithms are effective, after two correction steps, the residual pupil shift is reduced to less than 5% of a Shack-Hartmann sub-aperture.
Tracking and Following Algorithms of Mobile Robots for Service Activities in Dynamic Environments
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Feng-Li Lian
2015-02-01
Full Text Available By providing the capability of following a human target in an appropriate manner, the robot can assist people in various ways under different environments. One of the main difficulties when performing human tracking and following is the occlusion problem caused by static as well as dynamic obstacles. The aim of the paper is to tackle the occlusion problem by planning a robotic trajectory of maximizing target visibility and following the moving target. Initially, a laser range finder is used to detect the human target and then robustly track the target using the Kalman filter. Afterward, a human following algorithm based on a look-ahead algorithm, DWA*, is implemented to pursue the target while avoiding any static or dynamic obstacles. Fundamental experiments have been extensively tested to evaluate robot maneuvers and several field tests are conducted in more complex environments such as student cafeteria, computer center, and university library.
A generic sun-tracking algorithm for on-axis solar collector in mobile platforms
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.
A Target Tracking Algorithm based on Fractional Ambiguity Function in Impulsive Noise Environment
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Shi Xiaofei
2016-01-01
Full Text Available This paper proposes an airplane tracking algorithm based on study of the problem of interference localization. Firstly, a novel signal model to accurately estimate parameters of the airplane is proposed in impulsive noise environment. A method of instantaneous Doppler frequency estimation based on peak searching of the fractional lower-order ambiguity function based on the fractional Fourier transform (FLOS_FAF is proposed, and a method of projection approximation subspace tracking using robust m-estimation method based on fractional lower-order ambiguity function in fractional Fourier transform domain (FF-RLM_PAST is proposed to estimate the azimuth angle and elevation angle. As a result, the airplane tracking is achieved in bistatic radar, laying the foundations for interference localization. The correctness and effectiveness of the proposed method are verified with the computer simulation.
Gagnon, Louis-Guillaume; The ATLAS collaboration
2016-01-01
ATLAS track reconstruction code is continuously evolving to match the demands from the increasing instantaneous luminosity of LHC, as well as the increased centre-of-mass energy. With the increase in energy, events with dense environments, e.g. the cores of jets or boosted tau leptons, become much more abundant. These environments are characterised by charged particle separations on the order of ATLAS inner detector sensor dimensions and are created by the decay of boosted objects. Significant upgrades were made to the track reconstruction code to cope with the expected conditions during LHC Run 2. In particular, new algorithms targeting dense environments were developed. These changes lead to a substantial reduction of reconstruction time while at the same time improving physics performance. The employed methods are presented. In addition, physics performance studies are shown, e.g. a measurement of the fraction of lost tracks in jets with high transverse momentum.
A Novel Global MPP Tracking of Photovoltaic System based on Whale Optimization Algorithm
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Santhan Kumar Cherukuri
2016-11-01
Full Text Available To harvest maximum amount of solar energy and to attain higher efficiency, photovoltaic generation (PVG systems are to be operated at their maximum power point (MPP under both variable climatic and partial shaded condition (PSC. From literature most of conventional MPP tracking (MPPT methods are able to guarantee MPP successfully under uniform shading condition but fails to get global MPP as they may trap at local MPP under PSC, which adversely deteriorates the efficiency of Photovoltaic Generation (PVG system. In this paper a novel MPPT based on Whale Optimization Algorithm (WOA is proposed to analyze analytic modeling of PV system considering both series and shunt resistances for MPP tracking under PSC. The proposed algorithm is tested on 6S, 3S2P and 2S3P Photovoltaic array configurations for different shading patterns and results are presented. To compare the performance, GWO and PSO MPPT algorithms are also simulated and results are also presented. From the results it is noticed that proposed MPPT method is superior to other MPPT methods with reference to accuracy and tracking speed. Article History: Received July 23rd 2016; Received in revised form September 15th 2016; Accepted October 1st 2016; Available online How to Cite This Article: Kumar, C.H.S and Rao, R.S. (2016 A Novel Global MPP Tracking of Photovoltaic System based on Whale Optimization Algorithm. Int. Journal of Renewable Energy Development, 5(3, 225-232. http://dx.doi.org/10.14710/ijred.5.3.225-232
Carreno, Victor A.
2015-01-01
Pair-wise Trajectory Management (PTM) is a cockpit based delegated responsibility separation standard. When an air traffic service provider gives a PTM clearance to an aircraft and the flight crew accepts the clearance, the flight crew will maintain spacing and separation from a designated aircraft. A PTM along track algorithm will receive state information from the designated aircraft and from the own ship to produce speed guidance for the flight crew to maintain spacing and separation
Four-dimensional IMRT treatment planning using a DMLC motion-tracking algorithm
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Suh, Yelin [Department of Radiation Oncology, Virginia Commonwealth University, Richmond, VA (United States); Sawant, Amit; Venkat, Raghu; Keall, Paul J [Department of Radiation Oncology, Stanford University, 875 Black Wilbur Drive, Stanford, CA 94305-5847 (United States)], E-mail: ysuh@stanford.edu
2009-06-21
The purpose of this study is to develop a four-dimensional (4D) intensity-modulated radiation therapy (IMRT) treatment-planning method by modifying and applying a dynamic multileaf collimator (DMLC) motion-tracking algorithm. The 4D radiotherapy treatment scenario investigated is to obtain a 4D treatment plan based on a 4D computed tomography (CT) planning scan and to have the delivery flexible enough to account for changes in tumor position during treatment delivery. For each of 4D CT planning scans from 12 lung cancer patients, a reference phase plan was created; with its MLC leaf positions and three-dimensional (3D) tumor motion, the DMLC motion-tracking algorithm generated MLC leaf sequences for the plans of other respiratory phases. Then, a deformable dose-summed 4D plan was created by merging the leaf sequences of individual phase plans. Individual phase plans, as well as the deformable dose-summed 4D plan, are similar for each patient, indicating that this method is dosimetrically robust to the variations of fractional time spent in respiratory phases on a given 4D CT planning scan. The 4D IMRT treatment-planning method utilizing the DMLC motion-tracking algorithm explicitly accounts for 3D tumor motion and thus hysteresis and nonlinear motion, and is deliverable on a linear accelerator.
Fiber tracking algorithm in combined PIV/PTV measurement of fiber suspension flow
Hoseini, Afshin Abbasi; Zavareh, Zahra; Lundell, Fredrik; Anderson, Helge I.
2013-10-01
A new algorithm for fiber tracking in combined PIV/PTV measurement of fiber suspension flow is proposed based on SOM neural network and is examined by synthetic images of fibers showing 2D suspension flows. There is a new idea in the algorithm to take the orientation of fibers into account for matching as well as their position. In two-phase PIV measurements of fiber-laded suspension flows, fiber tracking has a key role together with PIV measurement of fluid phase. The essential parts of fiber tracking are to correctly identify and match fibers in successive images. The development of a method in order to determine the position and orientation of fibers using steerable filter with a reasonable accuracy have already been done, [3]. The present study is concentrated in the development of an algorithm for pairing fibers in consecutive images. The method used is based on the SOM neural network that finds most likely matching link in images on the basis of feature extraction and clustering. The fundamental concept is finding the corresponding fibers with the nearest characteristics, position and angle in images. It improves not only the robustness against loss-of-pair fibers between two image frames but also reliable matching at large numbers of dispersed fibers image using one more characteristics of fibers in image, namely their orientation, in addition to their coordinate vector.
Speed-up hyperspheres homotopic path tracking algorithm for PWL circuits simulations.
Ramirez-Pinero, A; Vazquez-Leal, H; Jimenez-Fernandez, V M; Sedighi, H M; Rashidi, M M; Filobello-Nino, U; Castaneda-Sheissa, R; Huerta-Chua, J; Sarmiento-Reyes, L A; Laguna-Camacho, J R; Castro-Gonzalez, F
2016-01-01
In the present work, we introduce an improved version of the hyperspheres path tracking method adapted for piecewise linear (PWL) circuits. This enhanced version takes advantage of the PWL characteristics from the homotopic curve, achieving faster path tracking and improving the performance of the homotopy continuation method (HCM). Faster computing time allows the study of complex circuits with higher complexity; the proposed method also decrease, significantly, the probability of having a diverging problem when using the Newton-Raphson method because it is applied just twice per linear region on the homotopic path. Equilibrium equations of the studied circuits are obtained applying the modified nodal analysis; this method allows to propose an algorithm for nonlinear circuit analysis. Besides, a starting point criteria is proposed to obtain better performance of the HCM and a technique for avoiding the reversion phenomenon is also proposed. To prove the efficiency of the path tracking method, several cases study with bipolar (BJT) and CMOS transistors are provided. Simulation results show that the proposed approach can be up to twelve times faster than the original path tracking method and also helps to avoid several reversion cases that appears when original hyperspheres path tracking scheme was employed.
Alessandrini, Martino; Heyde, Brecht; Queiros, Sandro; Cygan, Szymon; Zontak, Maria; Somphone, Oudom; Bernard, Olivier; Sermesant, Maxime; Delingette, Herve; Barbosa, Daniel; De Craene, Mathieu; ODonnell, Matthew; Dhooge, Jan
2016-08-01
A plethora of techniques for cardiac deformation imaging with 3D ultrasound, typically referred to as 3D speckle tracking techniques, are available from academia and industry. Although the benefits of single methods over alternative ones have been reported in separate publications, the intrinsic differences in the data and definitions used makes it hard to compare the relative performance of different solutions. To address this issue, we have recently proposed a framework to simulate realistic 3D echocardiographic recordings and used it to generate a common set of ground-truth data for 3D speckle tracking algorithms, which was made available online. The aim of this study was therefore to use the newly developed database to contrast non-commercial speckle tracking solutions from research groups with leading expertise in the field. The five techniques involved cover the most representative families of existing approaches, namely block-matching, radio-frequency tracking, optical flow and elastic image registration. The techniques were contrasted in terms of tracking and strain accuracy. The feasibility of the obtained strain measurements to diagnose pathology was also tested for ischemia and dyssynchrony.
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Hanxiao Wu
2012-10-01
Full Text Available In this paper, we propose an application of a compressive imaging system to the problem of wide-area video surveillance systems. A parallel coded aperture compressive imaging system is proposed to reduce the needed high resolution coded mask requirements and facilitate the storage of the projection matrix. Random Gaussian, Toeplitz and binary phase coded masks are utilized to obtain the compressive sensing images. The corresponding motion targets detection and tracking algorithms directly using the compressive sampling images are developed. A mixture of Gaussian distribution is applied in the compressive image space to model the background image and for foreground detection. For each motion target in the compressive sampling domain, a compressive feature dictionary spanned by target templates and noises templates is sparsely represented. An l1 optimization algorithm is used to solve the sparse coefficient of templates. Experimental results demonstrate that low dimensional compressed imaging representation is sufficient to determine spatial motion targets. Compared with the random Gaussian and Toeplitz phase mask, motion detection algorithms using a random binary phase mask can yield better detection results. However using random Gaussian and Toeplitz phase mask can achieve high resolution reconstructed image. Our tracking algorithm can achieve a real time speed that is up to 10 times faster than that of the l1 tracker without any optimization.
Effects of Power Tracking Algorithms on Lifetime of Power Electronic Devices Used in Solar Systems
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Canras Batunlu
2016-10-01
Full Text Available In photovoltaic solar energy systems, power management algorithms (PMAs, usually called maximum power point tracking (MPPT algorithms, are widely used for extracting maximum available power at every point in time. However, tracking the maximum power has negative effects on the availability of solar energy systems. This is due, mainly, to the created disturbances and thermal stresses on the associated power electronic converters (PECs. This work investigates the effects of PMA on the lifetime consumption, thermal stresses and failures on DC-DC converters used in solar systems. Firstly theoretical analysis and modelling of photovoltaic solar systems including converter’s electro thermal characteristics were developed. Subsequently, experiments on photovoltaic solar systems were carried out using two different PMAs, namely, perturb and observe (P&O and incremental conductance (IC. Real-time data was collected, under different operating conditions, including thermal behavior using thermal imaging camera and dSPACE. Converters’ thermal cycling was found to be approximately 3 °C higher with the IC algorithm. The steady state temperature was 52.7 °C, for the IC while it was 42.6 °C for P&O. Although IC algorithm offers more accurate power management tool, it causes more severe thermal stresses which, in this study, has led to approximately 1.4 times greater life consumption compared to P&O.
A Fast Algorithm for Muon Track Reconstruction and its Application to the ANTARES Neutrino Telescope
Aguilar, J A; Albert, A; Andre, M; Anghinolfi, M; Anton, G; Anvar, S; Ardid, M; Jesus, A C Assis; 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; Carloganu, 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; Galata, S; Gay, P; Giacomelli, G; Gomez-Gonzalez, J P; Graf, K; Guillard, G; Halladjian, G; Hallewell, G; van Haren, H; Heijboer, A J; Hello, Y; Hernandez-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; Lefevre, D; Lim, G; Presti, D Lo; 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; Pavalas, 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; Zuniga, J
2011-01-01
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.
A fast algorithm for muon track reconstruction and its application to the ANTARES neutrino telescope
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.
Implementation of a sensor guided flight algorithm for target tracking by small UAS
Collins, Gaemus E.; Stankevitz, Chris; Liese, Jeffrey
2011-06-01
Small xed-wing UAS (SUAS) such as Raven and Unicorn have limited power, speed, and maneuverability. Their missions can be dramatically hindered by environmental conditions (wind, terrain), obstructions (buildings, trees) blocking clear line of sight to a target, and/or sensor hardware limitations (xed stare, limited gimbal motion, lack of zoom). Toyon's Sensor Guided Flight (SGF) algorithm was designed to account for SUAS hardware shortcomings and enable long-term tracking of maneuvering targets by maintaining persistent eyes-on-target. SGF was successfully tested in simulation with high-delity UAS, sensor, and environment models, but real- world ight testing with 60 Unicorn UAS revealed surprising second order challenges that were not highlighted by the simulations. This paper describes the SGF algorithm, our rst round simulation results, our second order discoveries from ight testing, and subsequent improvements that were made to the algorithm.
Directory of Open Access Journals (Sweden)
Markku Renfors
2007-12-01
Full Text Available The ever-increasing public interest in location and positioning services has originated a demand for higher performance global navigation satellite systems (GNSSs. In order to achieve this incremental performance, the estimation of line-of-sight (LOS delay with high accuracy is a prerequisite for all GNSSs. The delay lock loops (DLLs and their enhanced variants (i.e., feedback code tracking loops are the structures of choice for the commercial GNSS receivers, but their performance in severe multipath scenarios is still rather limited. In addition, the new satellite positioning system proposals specify the use of a new modulation, the binary offset carrier (BOC modulation, which triggers a new challenge in the code tracking stage. Therefore, in order to meet this emerging challenge and to improve the accuracy of the delay estimation in severe multipath scenarios, this paper analyzes feedback as well as feedforward code tracking algorithms and proposes the peak tracking (PT methods, which are combinations of both feedback and feedforward structures and utilize the inherent advantages of both structures. We propose and analyze here two variants of PT algorithm: PT with second-order differentiation (Diff2, and PT with Teager Kaiser (TK operator, which will be denoted herein as PT(Diff2 and PT(TK, respectively. In addition to the proposal of the PT methods, the authors propose also an improved early-late-slope (IELS multipath elimination technique which is shown to provide very good mean-time-to-lose-lock (MTLL performance. An implementation of a noncoherent multipath estimating delay locked loop (MEDLL structure is also presented. We also incorporate here an extensive review of the existing feedback and feedforward delay estimation algorithms for direct sequence code division multiple access (DS-CDMA signals in satellite fading channels, by taking into account the impact of binary phase shift keying (BPSK as well as the newly proposed BOC modulation
Maximum Power Point Tracking Algorithms for Grid-Connected Photovoltaic Energy Conversion System
Directory of Open Access Journals (Sweden)
J.Surya Kumari
2013-12-01
Full Text Available As the use of energy is increasing, the requirements for the quality of the supplied electrical energy are more tighten. Energy is the most basic and essential of all resources. As conventional sources of energy are rapidly depleting and the cost of energy is rising, photovoltaic energy becomes a promising alternative source. Photovoltaic (PV generation is becoming increasingly important as a renewable source since it exhibits a great many merits such as cleanness, little maintenance and no noise. The output power of PV arrays is always changing with weather conditions, i.e., solar irradiation and atmospheric temperature. Therefore, a Maximum Power Point Tracking (MPPT control to extract maximum power from the PV arrays at real time becomes indispensable in PV generation system. In recent years, a large number of techniques have been proposed for tracking the maximum power point (MPP. MPPT is used in photovoltaic (PV systems to maximize the photovoltaic array output power, irrespective of the temperature and radiation conditions and of the load electrical characteristics the PV array output power is used to directly control the dc/dc converter, thus reducing the complexity of the system. The resulting system has high-efficiency. This paper presents in details comparison of most popular MPPT algorithms techniques which are Perturb & Observe algorithm(P&O and Improved Perturb & Observe algorithm(IPO. Improved Perturb & Observe algorithm (IPO, is a very promising technique that allows the increase of efficiency and reliability of such systems. Modeling and designing a PV system with Improved Perturb & Observe algorithm (IPO is remarkably more complex than implementing a standard MPPT technique. In this paper, Improved Perturb & Observe algorithm (IPO, system for PV arrays is proposed and analyzed.
Meanie3D - a mean-shift based, multivariate, multi-scale clustering and tracking algorithm
Simon, Jürgen-Lorenz; Malte, Diederich; Silke, Troemel
2014-05-01
Project OASE is the one of 5 work groups at the HErZ (Hans Ertel Centre for Weather Research), an ongoing effort by the German weather service (DWD) to further research at Universities concerning weather prediction. The goal of project OASE is to gain an object-based perspective on convective events by identifying them early in the onset of convective initiation and follow then through the entire lifecycle. The ability to follow objects in this fashion requires new ways of object definition and tracking, which incorporate all the available data sets of interest, such as Satellite imagery, weather Radar or lightning counts. The Meanie3D algorithm provides the necessary tool for this purpose. Core features of this new approach to clustering (object identification) and tracking are the ability to identify objects using the mean-shift algorithm applied to a multitude of variables (multivariate), as well as the ability to detect objects on various scales (multi-scale) using elements of Scale-Space theory. The algorithm works in 2D as well as 3D without modifications. It is an extension of a method well known from the field of computer vision and image processing, which has been tailored to serve the needs of the meteorological community. In spite of the special application to be demonstrated here (like convective initiation), the algorithm is easily tailored to provide clustering and tracking for a wide class of data sets and problems. In this talk, the demonstration is carried out on two of the OASE group's own composite sets. One is a 2D nationwide composite of Germany including C-Band Radar (2D) and Satellite information, the other a 3D local composite of the Bonn/Jülich area containing a high-resolution 3D X-Band Radar composite.
Strain estimation by a Fourier Series-based extrema tracking algorithm for elastography.
Wang, Wenxia; Hu, Danfeng; Wang, Jiajun; Zou, Wei
2015-09-01
In this paper, a new strain estimator using extrema tracking based on Fourier Series expansion (ETBFS) is proposed for ultrasonic elastography. In this method, the extremum is determined by solving an equation constructed by obtaining the first order derivative of the Fourier Series expansion and setting it to zero. Unlike other tracking algorithms, the ETBFS method can locate the extrema of radio frequency (RF) signals exactly between two adjacent sampling points and achieve a sub-sample accuracy without additional explicit interpolation. The correspondence between the located extrema in the pre- and post-compressed RF signal segments are constructed with a fine matching technique, with which the displacements and strains are estimated. Experimental results on a finite-element-modeling (FEM) simulation phantom show that the new proposed method can provide a more accurate displacement estimation than the standard cross-correlation (CC)-based method and the scale-invariant keypoints tracking (SIKT) algorithm. Moreover, performance analysis in terms of elastographic signal-to-noise ratio (SNRe), elastographic contrast-to-noise ratio (CNRe) and the real-versus-estimated strain error (RESE) also indicate that the dynamic range of the strain filter and its sensitivity can be improved with this new method.
Multi-Rate Digital Control Systems with Simulation Applications. Volume II. Computer Algorithms
1980-09-01
34 ~AFWAL-TR-80-31 01 • • Volume II L IL MULTI-RATE DIGITAL CONTROL SYSTEMS WITH SIMULATiON APPLICATIONS Volume II: Computer Algorithms DENNIS G. J...29 Ma -8 - Volume II. Computer Algorithms ~ / ’+ 44MWLxkQT N Uwe ~~ 4 ~jjskYIF336l5-79-C-369~ 9. PER~rORMING ORGANIZATION NAME AND ADDRESS IPROG AMEL...additional options. The analytical basis for the computer algorithms is discussed in Ref. 12. However, to provide a complete description of the program, some
Practical Velocity Tracking Control of a Parallel Robot Based on Fuzzy Adaptive Algorithm
Directory of Open Access Journals (Sweden)
Zude Zhou
2013-01-01
Full Text Available Due to the advantages of its compact structure and high operation accuracy, the six degrees of freedom (6-DOF parallel platform has been widely used as a carrier of medical rehabilitation devices. Fuzzy adaptive algorithm does not depend on the mathematical model of controlled object, which possesses good nonlinear characteristics. Those entire features make it an effective method to control such complex and coupling platforms. To facilitate the application of robotics in lower limb rehabilitation fields, a robotic system in practical environment was established based on kinematics modeling of the 6-DOF Stewart-based platform. In order to improve the velocity tracking accuracy, this paper proposed a closed-loop control strategy based on fuzzy adaptive algorithm. The velocity feedback information was utilized to modify the PID parameters adaptively in realtime through fuzzy inference units. Several experiments in practical environment were conducted, and the results demonstrated that the proposed algorithm could effectively reduce the speed jitter, enhance the position and velocity tracking precision of the robot, and the reliability and robustness of the system could also be ensured.
Directory of Open Access Journals (Sweden)
Pandu Sandi Pratama
2012-12-01
Full Text Available This paper proposed an algorithm to track the obstacle position and avoid the moving objects for differential driving Automatic Guided Vehicles (AGV system in industrial environment. This algorithm has several abilities such as: to detect the moving objects, to predict the velocity and direction of moving objects, to predict the collision possibility and to plan the avoidance maneuver. For sensing the local environment and positioning, the laser measurement system LMS-151 and laser navigation system NAV-200 are applied. Based on the measurement results of the sensors, the stationary and moving obstacles are detected and the collision possibility is calculated. The velocity and direction of the obstacle are predicted using Kalman filter algorithm. Collision possibility, time, and position can be calculated by comparing the AGV movement and obstacle prediction result obtained by Kalman filter. Finally the avoidance maneuver using the well known tangent Bug algorithm is decided based on the calculation data. The effectiveness of proposed algorithm is verified using simulation and experiment. Several examples of experiment conditions are presented using stationary obstacle, and moving obstacles. The simulation and experiment results show that the AGV can detect and avoid the obstacles successfully in all experimental condition. [Keywords— Obstacle avoidance, AGV, differential drive, laser measurement system, laser navigation system].
A multi-feature tracking algorithm enabling adaptation to context variations
Chau, Duc Phu; Thonnat, Monique
2011-01-01
We propose in this paper a tracking algorithm which is able to adapt itself to different scene contexts. A feature pool is used to compute the matching score between two detected objects. This feature pool includes 2D, 3D displacement distances, 2D sizes, color histogram, histogram of oriented gradient (HOG), color covariance and dominant color. An offline learning process is proposed to search for useful features and to estimate their weights for each context. In the online tracking process, a temporal window is defined to establish the links between the detected objects. This enables to find the object trajectories even if the objects are misdetected in some frames. A trajectory filter is proposed to remove noisy trajectories. Experimentation on different contexts is shown. The proposed tracker has been tested in videos belonging to three public datasets and to the Caretaker European project. The experimental results prove the effect of the proposed feature weight learning, and the robustness of the propose...
Co op erative Tracking Control for Networked Lagrange Systems：Algorithms and Exp eriments
Institute of Scientific and Technical Information of China (English)
CHEN Gang; YUE Yuan-Long; LIN Qing
2014-01-01
This paper considers the coordinated tracking problem for a group of Lagrange systems in the presence of parametric uncertainties. Distributed adaptive controllers are proposed with the aid of Lyapunov techniques. Compared with the previous work in the context of networked Lagrange systems control, the results in this paper are suitable for the general digraph communication topologies. Under the condition that the desired trajectory is only available to a portion of Lagrange systems, we discuss the cooperative tracking problem with general digraph communication topology, which contains a spanning tree with the root node being the active target system. Under the case where the neighbor0s velocity is unavailable, a distributed filter is introduced to overcome this deficiency. Experimental results on networked robot-arms are provided to show the effectiveness of the proposed control algorithms.
Energy Technology Data Exchange (ETDEWEB)
Larbes, C.; Ait Cheikh, S.M.; Obeidi, T.; Zerguerras, A. [Laboratoire des Dispositifs de Communication et de Conversion Photovoltaique, Departement d' Electronique, Ecole Nationale Polytechnique, 10, Avenue Hassen Badi, El Harrach, Alger 16200 (Algeria)
2009-10-15
This paper presents an intelligent control method for the maximum power point tracking (MPPT) of a photovoltaic system under variable temperature and irradiance conditions. First, for the purpose of comparison and because of its proven and good performances, the perturbation and observation (P and O) technique is briefly introduced. A fuzzy logic controller based MPPT (FLC) is then proposed which has shown better performances compared to the P and O MPPT based approach. The proposed FLC has been also improved using genetic algorithms (GA) for optimisation. Different development stages are presented and the optimized fuzzy logic MPPT controller (OFLC) is then simulated and evaluated, which has shown better performances. (author)
An optimal consensus tracking control algorithm for autonomous underwater vehicles with disturbances
Zhang, Jian Yuan Wen-Xia
2012-01-01
The optimal disturbance rejection control problem is considered for consensus tracking systems affected by external persistent disturbances and noise. Optimal estimated values of system states are obtained by recursive filtering for the multiple autonomous underwater vehicles modeled to multi-agent systems with Kalman filter. Then the feedforward-feedback optimal control law is deduced by solving the Riccati equations and matrix equations. The existence and uniqueness condition of feedforward-feedback optimal control law is proposed and the optimal control law algorithm is carried out. Lastly, simulations show the result is effectiveness with respect to external persistent disturbances and noise.
Energy Technology Data Exchange (ETDEWEB)
Yoon, Jai-Woong; Sawant, Amit; Suh, Yelin; Cho, Byung-Chul; Suh, Tae-Suk; Keall, Paul [Department of Biomedical Engineering, College of Medicine, Catholic University of Korea, Seoul, Korea 131-700 and Research Institute of Biomedical Engineering, Catholic University of Korea, Seoul, 131-700 (Korea, Republic of); Department of Radiation Oncology, Stanford University, Stanford, California 94305 (United States); Department of Radiation Oncology, Stanford University, Stanford, California 94305 (United States) and Department of Radiation Oncology, Asan Medical Center, Seoul, 138-736 (Korea, Republic of); Department of Biomedical Engineering, College of Medicine, Catholic University of Korea, Seoul, 131-700 and Research Institute of Biomedical Engineering, Catholic University of Korea, Seoul, 131-700 (Korea, Republic of); Department of Radiation Oncology, Stanford University, Stanford, California 94305 (United States) and Radiation Physics Laboratory, Sydney Medical School, University of Sydney, 2006 (Australia)
2011-07-15
Purpose: In dynamic multileaf collimator (MLC) motion tracking with complex intensity-modulated radiation therapy (IMRT) fields, target motion perpendicular to the MLC leaf travel direction can cause beam holds, which increase beam delivery time by up to a factor of 4. As a means to balance delivery efficiency and accuracy, a moving average algorithm was incorporated into a dynamic MLC motion tracking system (i.e., moving average tracking) to account for target motion perpendicular to the MLC leaf travel direction. The experimental investigation of the moving average algorithm compared with real-time tracking and no compensation beam delivery is described. Methods: The properties of the moving average algorithm were measured and compared with those of real-time tracking (dynamic MLC motion tracking accounting for both target motion parallel and perpendicular to the leaf travel direction) and no compensation beam delivery. The algorithm was investigated using a synthetic motion trace with a baseline drift and four patient-measured 3D tumor motion traces representing regular and irregular motions with varying baseline drifts. Each motion trace was reproduced by a moving platform. The delivery efficiency, geometric accuracy, and dosimetric accuracy were evaluated for conformal, step-and-shoot IMRT, and dynamic sliding window IMRT treatment plans using the synthetic and patient motion traces. The dosimetric accuracy was quantified via a {gamma}-test with a 3%/3 mm criterion. Results: The delivery efficiency ranged from 89 to 100% for moving average tracking, 26%-100% for real-time tracking, and 100% (by definition) for no compensation. The root-mean-square geometric error ranged from 3.2 to 4.0 mm for moving average tracking, 0.7-1.1 mm for real-time tracking, and 3.7-7.2 mm for no compensation. The percentage of dosimetric points failing the {gamma}-test ranged from 4 to 30% for moving average tracking, 0%-23% for real-time tracking, and 10%-47% for no compensation
Energy Technology Data Exchange (ETDEWEB)
Svensson, Urban [Computer-aided Fluid Engineering AB, Norrkoeping (Sweden)
2001-04-01
A particle tracking algorithm, PARTRACK, that simulates transport and dispersion in a sparsely fractured rock is described. The main novel feature of the algorithm is the introduction of multiple particle states. It is demonstrated that the introduction of this feature allows for the simultaneous simulation of Taylor dispersion, sorption and matrix diffusion. A number of test cases are used to verify and demonstrate the features of PARTRACK. It is shown that PARTRACK can simulate the following processes, believed to be important for the problem addressed: the split up of a tracer cloud at a fracture intersection, channeling in a fracture plane, Taylor dispersion and matrix diffusion and sorption. From the results of the test cases, it is concluded that PARTRACK is an adequate framework for simulation of transport and dispersion of a solute in a sparsely fractured rock.
Vadillo, Miguel A; Street, Chris N H; Beesley, Tom; Shanks, David R
2015-12-01
Poor calibration and inaccurate drift correction can pose severe problems for eye-tracking experiments requiring high levels of accuracy and precision. We describe an algorithm for the offline correction of eye-tracking data. The algorithm conducts a linear transformation of the coordinates of fixations that minimizes the distance between each fixation and its closest stimulus. A simple implementation in MATLAB is also presented. We explore the performance of the correction algorithm under several conditions using simulated and real data, and show that it is particularly likely to improve data quality when many fixations are included in the fitting process.
Directory of Open Access Journals (Sweden)
John M. Seiner
2009-03-01
Full Text Available An image pattern tracking algorithm is described in this paper for time-resolved measurements of mini- and micro-scale movements of complex objects. This algorithm works with a high-speed digital imaging system, which records thousands of successive image frames in a short time period. The image pattern of the observed object is tracked among successively recorded image frames with a correlation-based algorithm, so that the time histories of the position and displacement of the investigated object in the camera focus plane are determined with high accuracy. The speed, acceleration and harmonic content of the investigated motion are obtained by post processing the position and displacement time histories. The described image pattern tracking algorithm is tested with synthetic image patterns and verified with tests on live insects.
Simplified inverse filter tracking algorithm for estimating the mean trabecular bone spacing.
Huang, Kai; Ta, Dean; Wang, Weiqi; Le, L H
2008-07-01
Ultrasonic backscatter signals provide useful information relevant to bone tissue characterization. Trabecular bone microstructures have been considered as quasi-periodic tissues with a collection of regular and diffuse scatterers. This paper investigates the potential of a novel technique using a simplified inverse filter tracking (SIFT) algorithm to estimate mean trabecular bone spacing (MTBS) from ultrasonic backscatter signals. In contrast to other frequency-based methods, the SIFT algorithm is a time-based method and utilizes the amplitude and phase information of backscatter echoes, thus retaining the advantages of both the autocorrelation and the cepstral analysis techniques. The SIFT algorithm was applied to backscatter signals from simulations, phantoms, and bovine trabeculae in vitro. The estimated MTBS results were compared with those of the autoregressive (AR) cepstrum and quadratic transformation (QT) . The SIFT estimates are better than the AR cepstrum estimates and are comparable with the QT values. The study demonstrates that the SIFT algorithm has the potential to be a reliable and robust method for the estimation of MTBS in the presence of a small signal-to-noise ratio, a large spacing variation between regular scatterers, and a large scattering strength ratio of diffuse scatterers to regular ones.
Object Tracking Vision System for Mapping the UCN τ Apparatus Volume
Lumb, Rowan; UCNtau Collaboration
2016-09-01
The UCN τ collaboration has an immediate goal to measure the lifetime of the free neutron to within 0.1%, i.e. about 1 s. The UCN τ apparatus is a magneto-gravitational ``bottle'' system. This system holds low energy, or ultracold, neutrons in the apparatus with the constraint of gravity, and keeps these low energy neutrons from interacting with the bottle via a strong 1 T surface magnetic field created by a bowl-shaped array of permanent magnets. The apparatus is wrapped with energized coils to supply a magnetic field throughout the ''bottle'' volume to prevent depolarization of the neutrons. An object-tracking stereo-vision system will be presented that precisely tracks a Hall probe and allows a mapping of the magnetic field throughout the volume of the UCN τ bottle. The stereo-vision system utilizes two cameras and open source openCV software to track an object's 3-d position in space in real time. The desired resolution is +/-1 mm resolution along each axis. The vision system is being used as part of an even larger system to map the magnetic field of the UCN τ apparatus and expose any possible systematic effects due to field cancellation or low field points which could allow neutrons to depolarize and possibly escape from the apparatus undetected. Tennessee Technological University.
A comparative study of automatic image segmentation algorithms for target tracking in MR-IGRT.
Feng, Yuan; Kawrakow, Iwan; Olsen, Jeff; Parikh, Parag J; Noel, Camille; Wooten, Omar; Du, Dongsu; Mutic, Sasa; Hu, Yanle
2016-03-08
On-board magnetic resonance (MR) image guidance during radiation therapy offers the potential for more accurate treatment delivery. To utilize the real-time image information, a crucial prerequisite is the ability to successfully segment and track regions of interest (ROI). The purpose of this work is to evaluate the performance of different segmentation algorithms using motion images (4 frames per second) acquired using a MR image-guided radiotherapy (MR-IGRT) system. Manual con-tours of the kidney, bladder, duodenum, and a liver tumor by an experienced radiation oncologist were used as the ground truth for performance evaluation. Besides the manual segmentation, images were automatically segmented using thresholding, fuzzy k-means (FKM), k-harmonic means (KHM), and reaction-diffusion level set evolution (RD-LSE) algorithms, as well as the tissue tracking algorithm provided by the ViewRay treatment planning and delivery system (VR-TPDS). The performance of the five algorithms was evaluated quantitatively by comparing with the manual segmentation using the Dice coefficient and target registration error (TRE) measured as the distance between the centroid of the manual ROI and the centroid of the automatically segmented ROI. All methods were able to successfully segment the bladder and the kidney, but only FKM, KHM, and VR-TPDS were able to segment the liver tumor and the duodenum. The performance of the thresholding, FKM, KHM, and RD-LSE algorithms degraded as the local image contrast decreased, whereas the performance of the VP-TPDS method was nearly independent of local image contrast due to the reference registration algorithm. For segmenting high-contrast images (i.e., kidney), the thresholding method provided the best speed (< 1 ms) with a satisfying accuracy (Dice = 0.95). When the image contrast was low, the VR-TPDS method had the best automatic contour. Results suggest an image quality determination procedure before segmentation and a combination of
Designs and Algorithms to Map Eye Tracking Data with Dynamic Multielement Moving Objects
Mandal, Saptarshi
2016-01-01
Design concepts and algorithms were developed to address the eye tracking analysis issues that arise when (1) participants interrogate dynamic multielement objects that can overlap on the display and (2) visual angle error of the eye trackers is incapable of providing exact eye fixation coordinates. These issues were addressed by (1) developing dynamic areas of interests (AOIs) in the form of either convex or rectangular shapes to represent the moving and shape-changing multielement objects, (2) introducing the concept of AOI gap tolerance (AGT) that controls the size of the AOIs to address the overlapping and visual angle error issues, and (3) finding a near optimal AGT value. The approach was tested in the context of air traffic control (ATC) operations where air traffic controller specialists (ATCSs) interrogated multiple moving aircraft on a radar display to detect and control the aircraft for the purpose of maintaining safe and expeditious air transportation. In addition, we show how eye tracking analysis results can differ based on how we define dynamic AOIs to determine eye fixations on moving objects. The results serve as a framework to more accurately analyze eye tracking data and to better support the analysis of human performance. PMID:27725830
Assessing the performance of vessel wall tracking algorithms: the importance of the test phantom
Ramnarine, K. V.; Kanber, B.; Panerai, R. B.
2004-01-01
There is widespread clinical interest in assessing the mechanical properties of tissues and vessel walls. This study investigated the importance of the test phantom in providing a realistic assessment of clinical wall tracking performance for a variety of ultrasound modalities. B-mode, colour Doppler and Tissue Doppler Imaging (TDI) cineloop images were acquired using a Philips HDI5000 scanner and L12-5 probe. In-vivo longitudinal sections of 30 common carotid arteries and in-vitro images of pulsatile flow of a blood mimicking fluid through walled and wall-less tissue and vessel mimicking flow phantoms were analysed. Vessel wall tracking performance was assessed for our new probabilistic B-mode algorithm (PROBAL), and 3 different techniques implemented by Philips Medical Systems, based on B-mode edge detection (LDOT), colour Doppler (CVIQ) and TDI (TDIAWM). Precision (standard deviation/mean) of the peak systole dilations for respective PROBAL, LDOT, CVIQ and TDIAWM techniques were: 15.4 +/- 8.4%, 23 +/- 12.7%, 10 +/- 10% and 10.3 +/- 8.1% for the common carotid arteries; 6.4%, 22%, 11.6% and 34.5% for the wall-less flow phantom, 5.3%, 9.8%, 23.4% and 2.7% for the C-flex walled phantom and 3.9%, 2.6%, 1% and 3.2% for the latex walled phantom. The test phantom design and construction had a significant effect on the measurement of wall tracking performance.
A Method for Analog Implementation of Centroid Tracking Algorithm in a Video Signal
Directory of Open Access Journals (Sweden)
Payman Moallem
2007-06-01
Full Text Available The main goal of a video tracking algorithm is finding the location of a predefined target in successive video frames. Centroid pointing is one of the most efficient methods in the target tracking. This method can be simply implemented by a digital video processing system that includes a video memory and a powerful digital processor. Usually, the cost and the complexity of the digital video processor is high and in some applications, using analog video processor that includes only electronic devices like OPAMP, diodes, transistors, resistors and capacitors has lower cost, more efficient and more reliable. Implementing of the centroid in an analog video processor is not as simple as digital one, therefore in this paper, we introduce a novel formulation of the centroid that can be implemented in an analog video processor. We simulate the proposed method by MatLab simulink and compare the results with the area-based tracking that is usually used in analog video processors. The simulation results show that the proposed method is more reliable and accurate.
Designs and Algorithms to Map Eye Tracking Data with Dynamic Multielement Moving Objects
Directory of Open Access Journals (Sweden)
Ziho Kang
2016-01-01
Full Text Available Design concepts and algorithms were developed to address the eye tracking analysis issues that arise when (1 participants interrogate dynamic multielement objects that can overlap on the display and (2 visual angle error of the eye trackers is incapable of providing exact eye fixation coordinates. These issues were addressed by (1 developing dynamic areas of interests (AOIs in the form of either convex or rectangular shapes to represent the moving and shape-changing multielement objects, (2 introducing the concept of AOI gap tolerance (AGT that controls the size of the AOIs to address the overlapping and visual angle error issues, and (3 finding a near optimal AGT value. The approach was tested in the context of air traffic control (ATC operations where air traffic controller specialists (ATCSs interrogated multiple moving aircraft on a radar display to detect and control the aircraft for the purpose of maintaining safe and expeditious air transportation. In addition, we show how eye tracking analysis results can differ based on how we define dynamic AOIs to determine eye fixations on moving objects. The results serve as a framework to more accurately analyze eye tracking data and to better support the analysis of human performance.
Sun, Hong; Wu, Qian-zhong
2013-09-01
In order to improve the precision of optical-electric tracking device, proposing a kind of improved optical-electric tracking device based on MEMS, in allusion to the tracking error of gyroscope senor and the random drift, According to the principles of time series analysis of random sequence, establish AR model of gyro random error based on Kalman filter algorithm, then the output signals of gyro are multiple filtered with Kalman filter. And use ARM as micro controller servo motor is controlled by fuzzy PID full closed loop control algorithm, and add advanced correction and feed-forward links to improve response lag of angle input, Free-forward can make output perfectly follow input. The function of lead compensation link is to shorten the response of input signals, so as to reduce errors. Use the wireless video monitor module and remote monitoring software (Visual Basic 6.0) to monitor servo motor state in real time, the video monitor module gathers video signals, and the wireless video module will sent these signals to upper computer, so that show the motor running state in the window of Visual Basic 6.0. At the same time, take a detailed analysis to the main error source. Through the quantitative analysis of the errors from bandwidth and gyro sensor, it makes the proportion of each error in the whole error more intuitive, consequently, decrease the error of the system. Through the simulation and experiment results shows the system has good following characteristic, and it is very valuable for engineering application.
Evaluation of Real-Time Hand Motion Tracking Using a Range Camera and the Mean-Shift Algorithm
Lahamy, H.; Lichti, D.
2011-09-01
Several sensors have been tested for improving the interaction between humans and machines including traditional web cameras, special gloves, haptic devices, cameras providing stereo pairs of images and range cameras. Meanwhile, several methods are described in the literature for tracking hand motion: the Kalman filter, the mean-shift algorithm and the condensation algorithm. In this research, the combination of a range camera and the simple version of the mean-shift algorithm has been evaluated for its capability for hand motion tracking. The evaluation was assessed in terms of position accuracy of the tracking trajectory in x, y and z directions in the camera space and the time difference between image acquisition and image display. Three parameters have been analyzed regarding their influence on the tracking process: the speed of the hand movement, the distance between the camera and the hand and finally the integration time of the camera. Prior to the evaluation, the required warm-up time of the camera has been measured. This study has demonstrated the suitability of the range camera used in combination with the mean-shift algorithm for real-time hand motion tracking but for very high speed hand movement in the traverse plane with respect to the camera, the tracking accuracy is low and requires improvement.
EVALUATION OF REAL-TIME HAND MOTION TRACKING USING A RANGE CAMERA AND THE MEAN-SHIFT ALGORITHM
Directory of Open Access Journals (Sweden)
H. Lahamy
2012-09-01
Full Text Available Several sensors have been tested for improving the interaction between humans and machines including traditional web cameras, special gloves, haptic devices, cameras providing stereo pairs of images and range cameras. Meanwhile, several methods are described in the literature for tracking hand motion: the Kalman filter, the mean-shift algorithm and the condensation algorithm. In this research, the combination of a range camera and the simple version of the mean-shift algorithm has been evaluated for its capability for hand motion tracking. The evaluation was assessed in terms of position accuracy of the tracking trajectory in x, y and z directions in the camera space and the time difference between image acquisition and image display. Three parameters have been analyzed regarding their influence on the tracking process: the speed of the hand movement, the distance between the camera and the hand and finally the integration time of the camera. Prior to the evaluation, the required warm-up time of the camera has been measured. This study has demonstrated the suitability of the range camera used in combination with the mean-shift algorithm for real-time hand motion tracking but for very high speed hand movement in the traverse plane with respect to the camera, the tracking accuracy is low and requires improvement.
Evaluation of registration, compression and classification algorithms. Volume 1: Results
Jayroe, R.; Atkinson, R.; Callas, L.; Hodges, J.; Gaggini, B.; Peterson, J.
1979-01-01
The registration, compression, and classification algorithms were selected on the basis that such a group would include most of the different and commonly used approaches. The results of the investigation indicate clearcut, cost effective choices for registering, compressing, and classifying multispectral imagery.
Energy Technology Data Exchange (ETDEWEB)
Park, Dong Sun; Lee, Joon Whan; Kim, Hyong Suk; Yoon, Sook; Lee, Jin Ho; Han, Jeong Soo; Baek, Seong Hyun; Choi, Gap Chu [Chonbuk National University, Chonju (Korea, Republic of)
1996-07-01
The utilization of remote-control robot system in atomic power plants or nuclear-related facilities grows rapidly, to protect workers from high radiation environments. Such applications require complete stability of the robot system, then precisely tracking the robot is essential for the whole system. This research is to accomplish the goal by developing appropriate algorithms for remote-control robot systems. The research consists of two different approaches: target-tracking systems using kalman filters and neural networks. The tracking system under study uses vision sensors to obtain features of targets. A kalman filter model using the moving-position estimation technique is designed, and tested for tracking an object with a circle movement. Attributions of the tracking object are investigated and best features are extracted from the input imagery for the kalman filter model. A neural network tracking system is designed and experimented to trace a robot endeffector. This model is aimed to utilize the excellent capabilities of neural networks; nonlinear mapping between inputs and outputs, learning capability, and generalization capability. The neural tracker consists of two networks for position detection and prediction. Tracking algorithms are developed and experimented for the two models. Results to the experiments show that both models are promising as real-time target-tracking systems for remote-control robot systems. 20 refs., 34 figs. (author)
Implementation of Vision-based Object Tracking Algorithms for Motor Skill Assessments
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Beatrice Floyd
2015-06-01
Full Text Available Assessment of upper extremity motor skills often involves object manipulation, drawing or writing using a pencil, or performing specific gestures. Traditional assessment of such skills usually requires a trained person to record the time and accuracy resulting in a process that can be labor intensive and costly. Automating the entire assessment process will potentially lower the cost, produce electronically recorded data, broaden the implementations, and provide additional assessment infor-mation. This paper presents a low-cost, versatile, and easy-to-use algorithm to automatically detect and track single or multiple well-defined geometric shapes or markers. It therefore can be applied to a wide range of assessment protocols that involve object manipulation or hand and arm gestures. The algorithm localizes the objects using color thresholding and morphological operations and then estimates their 3-dimensional pose. The utility of the algorithm is demonstrated by implementing it for automating the following five protocols: the sport of Cup Stacking, the Soda Pop Coordination test, the Wechsler Block Design test, the visual-motor integration test, and gesture recognition.
Fast internal marker tracking algorithm for onboard MV and kV imaging systems.
Mao, W; Wiersma, R D; Xing, L
2008-05-01
Intrafraction organ motion can limit the advantage of highly conformal dose techniques such as intensity modulated radiation therapy (IMRT) due to target position uncertainty. To ensure high accuracy in beam targeting, real-time knowledge of the target location is highly desired throughout the beam delivery process. This knowledge can be gained through imaging of internally implanted radio-opaque markers with fluoroscopic or electronic portal imaging devices (EPID). In the case of MV based images, marker detection can be problematic due to the significantly lower contrast between different materials in comparison to their kV-based counterparts. This work presents a fully automated algorithm capable of detecting implanted metallic markers in both kV and MV images with high consistency. Using prior CT information, the algorithm predefines the volumetric search space without manual region-of-interest (ROI) selection by the user. Depending on the template selected, both spherical and cylindrical markers can be detected. Multiple markers can be simultaneously tracked without indexing confusion. Phantom studies show detection success rates of 100% for both kV and MV image data. In addition, application of the algorithm to real patient image data results in successful detection of all implanted markers for MV images. Near real-time operational speeds of approximately 10 frames/sec for the detection of five markers in a 1024 x 768 image are accomplished using an ordinary PC workstation.
TANGO—New tracking AlGOrithm for gamma-rays
Tashenov, S.; Gerl, J.
2010-10-01
For spectroscopy, polarimetry and imaging purposes a new γ-ray tracking algorithm has been developed featuring identification of Compton escape events. The rejection of these events results in a significant increase of the Peak/Total ratio. The initial photon energy is restored for these events. Although the energy resolution in the spectrum reconstructed from the escape events is lower than the one from the full-energy events, the Monte-Carlo simulations show that the combined spectrum has an increased detector full-energy efficiency of up to 130% compared to its intrinsic full-energy efficiency. The assumed geometrical origin of the photons is verified event-by-event. This enables separation of photons emitted from a target and from background sources. A linear polarization analysis of the γ-lines can be performed. The efficiency of the algorithm and the Peak/Total ratio depending on the detector properties is discussed along with the proposed optimization schemes. The influence of the intrinsic properties of the scattering process like Compton profile and electron recoiling is discussed as well. The described algorithm deals with single photon events with energies of ≈100 keV up to a few MeV.
TANGO-New tracking AlGOrithm for gamma-rays
Energy Technology Data Exchange (ETDEWEB)
Tashenov, S., E-mail: tashenov@fysik.su.s [Royal Institute of Technology (KTH), AlbaNova University Center, Roslagstullsbacken 21, SE-10691 Stockholm (Sweden); Stockholm University, AlbaNova University Center, Roslagstullsbacken 21, SE-10691 Stockholm (Sweden); GSI Helmholtzzentrum fuer Schwerionenforschung GmbH (GSI), Planckstrasse 1, 64291 Darmstadt (Germany); Gerl, J. [GSI Helmholtzzentrum fuer Schwerionenforschung GmbH (GSI), Planckstrasse 1, 64291 Darmstadt (Germany)
2010-10-21
For spectroscopy, polarimetry and imaging purposes a new {gamma}-ray tracking algorithm has been developed featuring identification of Compton escape events. The rejection of these events results in a significant increase of the Peak/Total ratio. The initial photon energy is restored for these events. Although the energy resolution in the spectrum reconstructed from the escape events is lower than the one from the full-energy events, the Monte-Carlo simulations show that the combined spectrum has an increased detector full-energy efficiency of up to 130% compared to its intrinsic full-energy efficiency. The assumed geometrical origin of the photons is verified event-by-event. This enables separation of photons emitted from a target and from background sources. A linear polarization analysis of the {gamma}-lines can be performed. The efficiency of the algorithm and the Peak/Total ratio depending on the detector properties is discussed along with the proposed optimization schemes. The influence of the intrinsic properties of the scattering process like Compton profile and electron recoiling is discussed as well. The described algorithm deals with single photon events with energies of {approx}100keV up to a few MeV.
McGee, William T
2009-01-01
Intravascular volume status and volume responsiveness continue to be important questions for the management of critically ill or injured patients. Goal-directed hemodynamic therapy has been shown to be of benefit to patients with severe sepsis and septic shock, acute lung injury and adult respiratory distress syndrome, and for surgical patients in the operating room. Static measures of fluid status, central venous pressure (CVP), and pulmonary artery occlusion pressure (PAOP) are not useful in predicting volume responsiveness. Stroke volume variation and pulse pressure variation related to changes in stroke volume during positive pressure ventilation predict fluid responsiveness and represent an evolving practice for volume management in the intensive care unit (ICU) or operating room. Adoption of dynamic parameters for volume management has been inconsistent. This manuscript reviews some of the basic physiology regarding the use of stroke volume variation to predict fluid responsiveness in the ICU and operating room. A management algorithm using this physiology is proposed for the critically ill or injured in various settings.
Energy Technology Data Exchange (ETDEWEB)
Yepes, P [Rice University, Houston, TX 77005 (United States); Mirkovic, D [U.T M.D. Anderson Cancer Center, Houston, TX (United States); Mohan, R [UT MD Anderson Cancer Center, Houston, TX (United States)
2015-06-15
Purpose: To determine the suitability of fast Monte Carlo techniques for dose calculation in particle therapy based on track-repeating algorithm for Intensity Modulated Proton Therapy, IMPT. The application of this technique will make possible detailed retrospective studies of large cohort of patients, which may lead to a better determination of Relative Biological Effects from the analysis of patient data. Methods: A cohort of six head-and-neck patients treated at the University of Texas MD Anderson Cancer Center with IMPT were utilized. The dose distributions were calculated with the standard Treatment Plan System, TPS, MCNPX, GEANT4 and FDC, a fast track-repeating algorithm for proton therapy for the verification and the patient plans. FDC is based on a GEANT4 database of trajectories of protons in a water. The obtained dose distributions were compared to each other utilizing the g-index criteria for 3mm-3% and 2mm-2%, for the maximum spatial and dose differences. The γ-index was calculated for voxels with a dose at least 10% of the maximum delivered dose. Dose Volume Histograms are also calculated for the various dose distributions. Results: Good agreement between GEANT4 and FDC is found with less than 1% of the voxels with a γ-index larger than 1 for 2 mm-2%. The agreement between MCNPX with FDC is within the requirements of clinical standards, even though it is slightly worse than the comparison with GEANT4.The comparison with TPS yielded larger differences, what is also to be expected because pencil beam algorithm do not always performed well in highly inhomogeneous areas like head-and-neck. Conclusion: The good agreement between a track-repeating algorithm and a full Monte Carlo for a large cohort of patients and a challenging, site like head-and-neck, opens the path to systematic and detailed studies of large cohorts, which may yield better understanding of biological effects.
Institute of Scientific and Technical Information of China (English)
YU Zhi-jun; WEI Jian-ming; LIU Hai-tao
2009-01-01
Target tracking is one of the most important applications of wireless sensor networks. Optimized computation and energy dissipation are critical requirements to save the limited resource of sensor nodes. A new robust and energy-efficient collaborative target tracking framework is proposed in this article. After a target is detected, only one active cluster is responsible for the tracking task at each time step. The tracking algorithm is distributed by passing the sensing and computation operations from one cluster to another. An event-driven cluster reforming scheme is also proposed for balancing energy consumption among nodes. Observations from three cluster members are chosen and a new class of particle filter termed cost-reference particle filter (CRPF) is introduced to estimate the target motion at the cluster head. This CRPF method is quite robust for wireless sensor network tracking applications because it drops the strong assumptions of knowing the probability distributions of the system process and observation noises. In simulation experiments, the performance of the proposed collaborative target tracking algorithm is evaluated by the metrics of tracking precision and network energy consumption.
Effects of Walls and Floors in Indoor Localization Using Tracking Algorithm
Directory of Open Access Journals (Sweden)
Farhat M. A. Zargoun
2016-03-01
Full Text Available The advancement in wireless and mobile networks has led to an increase in location based services (LBS. LBS can be applied in many applications, such as vehicle systems, security systems, and patient tracking systems. The Global Navigation Satellite Systems (GNSS have become very popular due to their ability to provide highly accurate positions, especially in outdoor environments. However, GNSS signals become very weak when they go through natural or man-made structure, like in urban canyons or indoor environments. This hinders the applicability of GNSS-based localization techniques in such challenging environments. Many indoor localization techniques are based on the received signal strength (RSS. An RSS is proportional to the distance to an access point (AP, where it is stronger in power when it is closer to an AP, given that the received signal is not obstructed by walls or floors. This paper aims at studying the effect of walls and floors on the RSS, and estimating the distribution of the RSS due to such obstructions. Moreover, a tracking algorithm based on a multi-walls and floors propagation model is applied to increase the positioning accuracy.
Directory of Open Access Journals (Sweden)
Deyuan Meng
2014-05-01
Full Text Available The dynamics of pneumatic systems are highly nonlinear, and there normally exists a large extent of model uncertainties; the precision motion trajectory tracking control of pneumatic cylinders is still a challenge. In this paper, two typical nonlinear controllers—adaptive controller and deterministic robust controller—are constructed firstly. Considering that they have both benefits and limitations, an adaptive robust controller (ARC is further proposed. The ARC is a combination of the first two controllers; it employs online recursive least squares estimation (RLSE to reduce the extent of parametric uncertainties, and utilizes the robust control method to attenuate the effects of parameter estimation errors, unmodeled dynamics, and disturbances. In order to solve the conflicts between the robust control design and the parameter adaption law design, the projection mapping is used to condition the RLSE algorithm so that the parameter estimates are kept within a known bounded convex set. Theoretically, ARC possesses the advantages of the adaptive control and the deterministic robust control, and thus an even better tracking performance can be expected. Extensive comparative experimental results are presented to illustrate the achievable performance of the three proposed controllers and their performance robustness to the parameter variations and sudden disturbance.
Ramachandran, Ganesh K.; Akopian, David; Heckler, Gregory W.; Winternitz, Luke B.
2011-01-01
Location technologies have many applications in wireless communications, military and space missions, etc. US Global Positioning System (GPS) and other existing and emerging Global Navigation Satellite Systems (GNSS) are expected to provide accurate location information to enable such applications. While GNSS systems perform very well in strong signal conditions, their operation in many urban, indoor, and space applications is not robust or even impossible due to weak signals and strong distortions. The search for less costly, faster and more sensitive receivers is still in progress. As the research community addresses more and more complicated phenomena there exists a demand on flexible multimode reference receivers, associated SDKs, and development platforms which may accelerate and facilitate the research. One of such concepts is the software GPS/GNSS receiver (GPS SDR) which permits a facilitated access to algorithmic libraries and a possibility to integrate more advanced algorithms without hardware and essential software updates. The GNU-SDR and GPS-SDR open source receiver platforms are such popular examples. This paper evaluates the performance of recently proposed block-corelator techniques for acquisition and tracking of GPS signals using open source GPS-SDR platform.
Robust guide-star tracking algorithm proposed for Gravity Probe-B relativity mission
Gwo, Dz-Hung
1997-09-01
The gravity probe-B cryogenic star-tracking telescope provides the inertial pointing reference, as established by a distant guide star, with milli-arc-second resolution for the NASA/Stanford relatively gyroscope experiment. The star image of the f/27 Cassegrainian telescope is split onto two focal planes by a 50/50 intensity splitter, with each resultant image further divided by a roof prism reflector to generate the quadrant pointing information within few arc-seconds about the guide-star direction. Conventionally, the quadrant pointing information can be derived through the difference- and-sum algorithm. In this article, an alternative simple, yet robust algorithm is proposed and compared with the conventional one in the following aspects: (1) requirements on near perfect star-image division, (2) optimization in selecting null direction, (3) compensation of null-direction drift due to differential aging of photon detectors, (4) operational definitions of response sensitivity, linearity, and linear range of motion measurement, (5) robustness in system redundancy in terms of options in single-detector pointing per axis.
Review of the maximum power point tracking algorithms for stand-alone photovoltaic systems
Energy Technology Data Exchange (ETDEWEB)
Salas, V.; Olias, E.; Barrado, A.; Lazaro, A. [Departamento de Tecnologia Electronica/Grupo de Sistemas Electronicos de Potencia, Universidad Carlos III de Madrid, Avda. de la Universidad, 30-28911 Leganes, Madrid (Spain)
2006-07-06
A survey of the algorithms for seeking the maximum power point (MPP) is proposed. As has been shown, there are many ways of distinguishing and grouping methods that seek the MPP from a photovoltaic (PV) generator. However, in this article they are grouped as either direct or nondirect methods. The indirect methods ('quasi seeks') have the particular feature that the MPP is estimated from the measures of the PV generator's voltage and current PV, the irradiance, or using empiric data, by mathematical expressions of numerical approximations. Therefore, the estimation is carried out for a specific PV generator installed in the system. Thus, they do not obtain the maximum power for any irradiance or temperature and none of them are able to obtain the MPP exactly. Subsequently, they are known as 'quasi seeks'. Nevertheless, the direct methods ('true seeking methods') can also be distinguished. They offer the advantage that they obtain the actual maximum power from the measures of the PV generator's voltage and current PV. In that case, they are suitable for any irradiance and temperature. All algorithms, direct and indirect, can be included in some of the DC/DC converters, Maximum power point trackings (MPPTs), for the stand-alone systems. (author)
Real-Time Volume Shadow using Visible-Non Visible Algorithm
Directory of Open Access Journals (Sweden)
Hoshang Kolivand
2011-01-01
Full Text Available Problem statement: Shadows are most important effect to make realistic games and visually appealing images, but they are poor in frame per second. Silhouette detection is most important phases to create real-time shadow. Approach: Present study describes a real-time shadow generated with volume shadow algorithm using Visible-Non Visible algorithm (VNV in virtual environment illuminated by a movable light source to improve the frame per second. Silhouette detection that is most expensive part of shadow creation was described. Triangular method and VNV method were compared. An improved algorithm for volume shadow was proposed and volume shadow using both methods in C+ Opengl implemented. Results: The VNV algorithm increases the number of Frame Per Second (FPS and as a result decreases the cost of implementation. Conclusion: A verified algorithm for volume shadow makes it easy to understand by everyone how to produce real-time shadow in outdoor and indoor virtual environment. It is possible to use it in current commercial games or other virtual reality systems.
Energy Technology Data Exchange (ETDEWEB)
Dunfee, J.; Leonard, L.; Rumbarger, J.
1980-01-01
The Franklin Research Center (FRC), a Division of the Franklin Institute, was contracted by the Bureau of Mines to improve walking dragline roller tracks. The contract was subsequently transferred to the Department of Energy. The period from September 1977 to September 1978 covered laboratory rolling contact rig tests to evaluate typical low hardness dragline track materials. The results of this work are covered by DOE/ET/9121-1 Final Report, Volume I. The period from September 1978 to July 1980 covered field measurements of dragline roller circle loadings. The results of this work are covered by DOE/ET/9121-2 Final Report, Volume II. The laboratory rolling contact rig test results indicate that forged vacuum degassed air melt steel materials are recommended over air-melt cast materials for rollers and tracks. The steels tested exhibited good freedom from sensitivity to stress raisers like brinell marks and small holes or discontinuities (Volume I). The largest unknown in a recommended method for life testing roller tracks is the condition of the upper rotating frame structure and the lower tub supporting structure.
Directory of Open Access Journals (Sweden)
Russel J Stonier
2003-08-01
Full Text Available In this paper we examine the application of evolutionary algorithms to find open-loop control solutions of the optimal control problem arising from the semidiscretisation of a linear parabolic tracking problem with boundary control. The solution is compared with the solutions obtained by methods based upon the variational equations of the Minimum Principle and the finite element method.
Jiang, Qingan; Wu, Wenqi; Jiang, Mingming; Li, Yun
2017-06-19
High-accuracy railway track surveying is essential for railway construction and maintenance. The traditional approaches based on total station equipment are not efficient enough since high precision surveying frequently needs static measurements. This paper proposes a new filtering and smoothing algorithm based on the IMU/odometer and landmarks integration for the railway track surveying. In order to overcome the difficulty of estimating too many error parameters with too few landmark observations, a new model with completely observable error states is established by combining error terms of the system. Based on covariance analysis, the analytical relationship between the railway track surveying accuracy requirements and equivalent gyro drifts including bias instability and random walk noise are established. Experiment results show that the accuracy of the new filtering and smoothing algorithm for railway track surveying can reach 1 mm (1σ) when using a Ring Laser Gyroscope (RLG)-based Inertial Measurement Unit (IMU) with gyro bias instability of 0.03°/h and random walk noise of 0.005 °h while control points of the track control network (CPIII) position observations are provided by the optical total station in about every 60 m interval. The proposed approach can satisfy at the same time the demands of high accuracy and work efficiency for railway track surveying.
Directory of Open Access Journals (Sweden)
Qingan Jiang
2017-06-01
Full Text Available High-accuracy railway track surveying is essential for railway construction and maintenance. The traditional approaches based on total station equipment are not efficient enough since high precision surveying frequently needs static measurements. This paper proposes a new filtering and smoothing algorithm based on the IMU/odometer and landmarks integration for the railway track surveying. In order to overcome the difficulty of estimating too many error parameters with too few landmark observations, a new model with completely observable error states is established by combining error terms of the system. Based on covariance analysis, the analytical relationship between the railway track surveying accuracy requirements and equivalent gyro drifts including bias instability and random walk noise are established. Experiment results show that the accuracy of the new filtering and smoothing algorithm for railway track surveying can reach 1 mm (1σ when using a Ring Laser Gyroscope (RLG-based Inertial Measurement Unit (IMU with gyro bias instability of 0.03°/h and random walk noise of 0.005 °h while control points of the track control network (CPIII position observations are provided by the optical total station in about every 60 m interval. The proposed approach can satisfy at the same time the demands of high accuracy and work efficiency for railway track surveying.
Directory of Open Access Journals (Sweden)
Xiang Gao
2012-05-01
Full Text Available In order to process target tracking approximation with unknown motion state models beforehand in a two-dimensional field of binary proximity sensors, the algorithms based on cost functions of particle filters and near-linear curve simple optimization are proposed in this paper. Through moving target across detecting intersecting fields of sensor nodes sequentially, cost functions are introduced to solve target tracking approximation and velocity estimation which is not similar to traditional particle filters that rely on probabilistic assumptions about the motion states. Then a near-linear curve geometric approach is used to simplify and easily describe target trajectories that are below a certain error measure. Because there maybe some sensor nodes invalid in practice, so a fault-tolerant detection is applied to avoid the nodes’ reporting fault and also improve accuracy of tracking at the same time. The validity of our algorithms is demonstrated through simulation results.
DEFF Research Database (Denmark)
Pontefisso, Alessandro; Zappalorto, Michele; Quaresimin, Marino
2016-01-01
In this work, a study of the Random Sequential Absorption (RSA) algorithm in the generation of nanoplatelet Volume Elements (VEs) is carried out. The effect of the algorithm input parameters on the reinforcement distribution is studied through the implementation of statistical tools, showing...... that the platelet distribution is systematically affected by these parameters. The consequence is that a parametric analysis of the VE input parameters may be biased by hidden differences in the filler distribution. The same statistical tools used in the analysis are implemented in a modified RSA algorithm...
Open-source feature-tracking algorithm for sea ice drift retrieval from Sentinel-1 SAR imagery
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.
Energy Technology Data Exchange (ETDEWEB)
Chao, R.M.; Ko, S.H.; Lin, I.H. [Department of Systems and Naval Mechatronics Engineering, National Cheng Kung University, Tainan, Taiwan 701 (China); Pai, F.S. [Department of Electronic Engineering, National University of Tainan (China); Chang, C.C. [Department of Environment and Energy, National University of Tainan (China)
2009-12-15
The historically high cost of crude oil price is stimulating research into solar (green) energy as an alternative energy source. In general, applications with large solar energy output require a maximum power point tracking (MPPT) algorithm to optimize the power generated by the photovoltaic effect. This work aims to provide a stand-alone solution for solar energy applications by integrating a DC/DC buck converter to a newly developed quadratic MPPT algorithm along with its appropriate software and hardware. The quadratic MPPT method utilizes three previously used duty cycles with their corresponding power outputs. It approaches the maximum value by using a second order polynomial formula, which converges faster than the existing MPPT algorithm. The hardware implementation takes advantage of the real-time controller system from National Instruments, USA. Experimental results have shown that the proposed solar mechatronics system can correctly and effectively track the maximum power point without any difficulties. (author)
Directory of Open Access Journals (Sweden)
Irina Rudeva
2014-12-01
Full Text Available The IMILAST project (‘Intercomparison of Mid-Latitude Storm Diagnostics’ was set up to compare low-level cyclone climatologies derived from a number of objective identification algorithms. This paper is a contribution to that effort where we determine the sensitivity of three key aspects of Northern Hemisphere cyclone behaviour [namely the number of cyclones, their intensity (defined here in terms of the central pressure and their deepening rates] to specific features in the automatic cyclone identification. The sensitivity is assessed with respect to three such features which may be thought to influence the ultimate climatology produced (namely performance in areas of complicated orography, time of the detection of a cyclone, and the representation of rapidly propagating cyclones. We make use of 13 tracking methods in this analysis. We find that the filtering of cyclones in regions where the topography exceeds 1500 m can significantly change the total number of cyclones detected by a scheme, but has little impact on the cyclone intensity distribution. More dramatically, late identification of cyclones (simulated by the truncation of the first 12 hours of cyclone life cycle leads to a large reduction in cyclone numbers over the both continents and oceans (up to 80 and 40%, respectively. Finally, the potential splitting of the trajectories at times of the fastest propagation has a negligible climatological effect on geographical distribution of cyclone numbers. Overall, it has been found that the averaged deepening rates and averaged cyclone central pressure are rather insensitive to the specifics of the tracking procedure, being more sensitive to the data set used (as shown in previous studies and the geographical location of a cyclone.
A Fuzzy Track Association Algorithm in Track Interrupt-oriented%面向航迹中断的模糊航迹关联算法
Institute of Scientific and Technical Information of China (English)
杜渐; 夏学知
2013-01-01
In afloat battlefield situation,because of system error,EMI,geographical environment,electronic silent,etc.,problems of sensor signal interrupt,target lost and track discontinuity appear.Aiming at these problems,this study presents an improved fuzzy track association algorithm.Using the method of uniting speed fuzzy factor,course fuzzy factor,improving acceleration fuzzy factor,twice association strategy and autoregulation association threshold value of membership function,the algorithm achieves track association of high maneuverable targets with long time interrupts,ensures the oneness and stability of situation.The Monte Carlo simulation results show that the algorithm is effective to solve the association problem under the condition of track interrupt and has a high robustness.%针对海战场态势中,由于系统误差、电磁干扰、地理环境隔绝、电子静默等原因,出现的传感器信号长时间中断、目标丢失,导致态势中航迹不连续的问题,提出了一种改进的模糊航迹关联算法.该算法通过采用统一速度模糊因素和方向模糊因素、改进加速度模糊因素、制定二级关联策略和自动调整隶属度函数关联阈值等方法,实现了在目标机动性较强、中断时间较长等情况下的航迹关联,保证了态势的稳定.通过Monte Carlo仿真实验表明,该算法具备较高的关联性和鲁棒性.
Institute of Scientific and Technical Information of China (English)
Hong-ying Man; Zhong-ci Shi
2006-01-01
In this paper, we discuss the finite volume element method of P1-nonconforming quadrilateral element for elliptic problems and obtain optimal error estimates for general quadrilateral partition. An optimal cascadic multigrid algorithm is proposed to solve the nonsymmetric large-scale system resulting from such discretization. Numerical experiments are reported to support our theoretical results.
Institute of Scientific and Technical Information of China (English)
Wenjing Du; Peili Wang; Lipeng Song; Lin Cheng
2015-01-01
A conduction heat transfer process is enhanced by filling prescribed quantity and optimized-shaped high thermal conductivity materials to the substrate. Numerical simulations and analyses are performed on a volume to point conduction problem based on the principle of minimum entropy generation. In the optimization, the arrange-ment of high thermal conductivity materials is variable, the quantity of high thermal-conductivity material is constrained, and the objective is to obtain the maximum heat conduction rate as the entropy is the minimum. A novel algorithm of thermal conductivity discretization is proposed based on large quantity of calculations. Compared with other algorithms in literature, the average temperature in the substrate by the new algorithm is lower, while the highest temperature in the substrate is in a reasonable range. Thus the new algorithm is fea-sible. The optimization of volume to point heat conduction is carried out in a rectangular model with radiation boundary condition and constant surface temperature boundary condition. The results demonstrate that the al-gorithm of thermal conductivity discretization is applicable for volume to point heat conduction problems.
Dupnick, E.; Wiggins, D.
1980-01-01
The functional specifications, functional design and flow, and the program logic of the GREEDY computer program are described. The GREEDY program is a submodule of the Scheduling Algorithm for Mission Planning and Logistics Evaluation (SAMPLE) program and has been designed as a continuation of the shuttle Mission Payloads (MPLS) program. The MPLS uses input payload data to form a set of feasible payload combinations; from these, GREEDY selects a subset of combinations (a traffic model) so all payloads can be included without redundancy. The program also provides the user a tutorial option so that he can choose an alternate traffic model in case a particular traffic model is unacceptable.
Directory of Open Access Journals (Sweden)
Xiaoyan Lei
2016-01-01
Full Text Available A model for dynamic analysis of the vehicle-track nonlinear coupling system is established by the finite element method. The whole system is divided into two subsystems: the vehicle subsystem and the track subsystem. Coupling of the two subsystems is achieved by equilibrium conditions for wheel-to-rail nonlinear contact forces and geometrical compatibility conditions. To solve the nonlinear dynamics equations for the vehicle-track coupling system, a cross iteration algorithm and a relaxation technique are presented. Examples of vibration analysis of the vehicle and slab track coupling system induced by China’s high speed train CRH3 are given. In the computation, the influences of linear and nonlinear wheel-to-rail contact models and different train speeds are considered. It is found that the cross iteration algorithm and the relaxation technique have the following advantages: simple programming; fast convergence; shorter computation time; and greater accuracy. The analyzed dynamic responses for the vehicle and the track with the wheel-to-rail linear contact model are greater than those with the wheel-to-rail nonlinear contact model, where the increasing range of the displacement and the acceleration is about 10%, and the increasing range of the wheel-to-rail contact force is less than 5%.
Institute of Scientific and Technical Information of China (English)
WANG Ke; HUANG Zhi; ZHONG Zhihua
2014-01-01
Due to the large variations of environment with ever-changing background and vehicles with different shapes, colors and appearances, to implement a real-time on-board vehicle recognition system with high adaptability, efficiency and robustness in complicated environments, remains challenging. This paper introduces a simultaneous detection and tracking framework for robust on-board vehicle recognition based on monocular vision technology. The framework utilizes a novel layered machine learning and particle filter to build a multi-vehicle detection and tracking system. In the vehicle detection stage, a layered machine learning method is presented, which combines coarse-search and fine-search to obtain the target using the AdaBoost-based training algorithm. The pavement segmentation method based on characteristic similarity is proposed to estimate the most likely pavement area. Efficiency and accuracy are enhanced by restricting vehicle detection within the downsized area of pavement. In vehicle tracking stage, a multi-objective tracking algorithm based on target state management and particle filter is proposed. The proposed system is evaluated by roadway video captured in a variety of traffics, illumination, and weather conditions. The evaluating results show that, under conditions of proper illumination and clear vehicle appearance, the proposed system achieves 91.2% detection rate and 2.6% false detection rate. Experiments compared to typical algorithms show that, the presented algorithm reduces the false detection rate nearly by half at the cost of decreasing 2.7%–8.6% detection rate. This paper proposes a multi-vehicle detection and tracking system, which is promising for implementation in an on-board vehicle recognition system with high precision, strong robustness and low computational cost.
Online Doctor Reviews: Do They Track Surgeon Volume, a Proxy for Quality of Care?
Sacopulos, Michael; Sheets, Virgil; Thurston, Irish; Brooks, Kendra; Puccia, Ryan
2012-01-01
about quality of care (HV: mean = 0.64; LV: mean = 0.51, P=.002); and (4) the proportion of scathing criticism/total comments about quality of care (HV: mean = 0.14; LV: mean = 0.23, P= .005). Even when these features were combined, the effect size, although significant, was still weak. The results revealed that one could accurately identify a physician’s patient volume via discriminant and classification analysis 61.6% of the time. We also found that high-volume surgeons could not be differentiated from low-volume surgeons by analyzing (1) standardized z score numerical ratings (HV: mean = 0.07; LV: mean = 0, P=.27); (2) proportion of glowing praise/total comments about customer service (HV: mean = 0.24; LV: mean = 0.22, P=.52); and (3) proportion of scathing criticism/total comments about customer service (HV: mean = 0.19; LV: mean = 0.21, P=.48). Conclusions Online review websites provide a rich source of data that may be able to track quality of care, although the effect size is weak and not consistent for all review website metrics. PMID:22491423
Directory of Open Access Journals (Sweden)
Ahteshamul Haque
2016-02-01
Full Text Available The energy crisis concern leads to look for alternate source of energy. Solar energy is considered as most reliable among the all renewable energy sources. Solar PV (Photovoltaic is used to convert solar energy into electric energy. The efficiency of solar PV is very low and its characteristic is nonlinear. To overcome these drawbacks a technique known as maximum power point tracking is used. This algorithm is implemented in the control circuit of DC – DC converter. The objective of this paper is to evaluate the MPPT (Maximum Power Point Tracking with buck DC-DC converter under load varying conditions. The simulation work is done using PSIM simulation software.
El-Gamal, S.; Abdalla, Ayman M.; Abdel-Hady, E. E.
2015-09-01
The alpha particle track diameter dependence of the free volume holes size (Vf) in DAM-ADC and CR-39 nuclear track detectors was investigated using positron annihilation lifetime technique. The effect of temperature on the alpha particle track diameter and free volume were also investigated in the T-range (RT-130 °C). The obtained results revealed that the values of ortho-positronium lifetime τ3 and Vf increases while I3 slightly increases as T increases for the two detectors. The values of τ3, Vf and I3 are higher in CR-39 than DAM-ADC. The interpretation of obtained results is based on the fact that increasing T leads to significant enhancement of thermal expansion of the polymer matrix and consequently Vf increases. The track diameter increases as T increases. This can be explained by the fact that the increase in T increases the crystal size and Vf in the polymer. A relationship between Vf and the alpha particle track diameter was obtained. Moreover results of detector irradiation, along with free volume evaluation are addressed and thoroughly discussed.
Energy Technology Data Exchange (ETDEWEB)
El-Gamal, S. [Physics Department, Faculty of Education, Ain Shams University, Roxy, 11711 Cairo (Egypt); Abdalla, Ayman M., E-mail: aymanabdalla62@hotmail.com [Physics Department, Faculty of Arts and Sciences, Najran University, Najran (Saudi Arabia); Centre for Advanced Materials and Nano-Engineering, Najran University, Najran 11001 (Saudi Arabia); Abdel-Hady, E.E. [Physics Department, Faculty of Science, Minia University, BO 61519, Minia (Egypt)
2015-09-15
The alpha particle track diameter dependence of the free volume holes size (V{sub f}) in DAM–ADC and CR-39 nuclear track detectors was investigated using positron annihilation lifetime technique. The effect of temperature on the alpha particle track diameter and free volume were also investigated in the T-range (RT-130 °C). The obtained results revealed that the values of ortho-positronium lifetime τ{sub 3} and V{sub f} increases while I{sub 3} slightly increases as T increases for the two detectors. The values of τ{sub 3}, V{sub f} and I{sub 3} are higher in CR-39 than DAM–ADC. The interpretation of obtained results is based on the fact that increasing T leads to significant enhancement of thermal expansion of the polymer matrix and consequently V{sub f} increases. The track diameter increases as T increases. This can be explained by the fact that the increase in T increases the crystal size and V{sub f} in the polymer. A relationship between V{sub f} and the alpha particle track diameter was obtained. Moreover results of detector irradiation, along with free volume evaluation are addressed and thoroughly discussed.
DEFF Research Database (Denmark)
Pommer, Tobias; Falk, Marianne; Poulsen, Per Rugaard
2013-01-01
to the target volume and an intraprostatic lesion (IPL) boosted approach with an increased dose to a subvolume of the prostate. The impact on plan quality of optimizations with a leaf position constraint, which limited the distance between neighbouring adjacent MLC leaves, was also investigated. Deliveries were...... during the first 75 s. A research DMLC tracking system was used for real-time motion compensation with optical monitoring for position input. The gamma index was used for evaluation, with measurements with a static phantom or the planned dose as reference, using 2% and 2 mm gamma criteria. The average...... pass rate with DMLC tracking was 99.9% (range 98.7-100%, measurement as reference), whereas the pass rate for untracked deliveries decreased distinctly as the average displacement increased, with an average pass rate of 61.3% (range 32.7-99.3%). Dose-volume histograms showed that DMLC tracking...
Institute of Scientific and Technical Information of China (English)
BAI Rong-gang; QU Yu-gui; LIN Zhi-ting; WANG Qing-hua; ZHAO Bao-hua
2006-01-01
Sensor deployment is an important problem in mobile wireless sensor networks.This paper presents a distributed self-spreading deployment algorithm (SOMDA) for mobile sensors based on artificial neural-networks selforganizing maps algorithm.During the deployment,the nodes compete to track the event and cooperate to form an ordered topology.After going through the algorithm,the statistical distribution of the nodes approaches that of the events in the interest area.The performance of the algorithm is evaluated by the covered percentage of region/events,the detecting ability and the energy equalization of the networks.The simulation results indicate that SOMDA outperforms uniform and random deployment with lossless coverage,enhancive detecting ability and significant energy equalization.
A Progressive Black Top Hat Transformation Algorithm for Estimating Valley Volumes from DEM Data
Luo, W.; Pingel, T.; Heo, J.; Howard, A. D.
2013-12-01
The amount of valley incision and valley volume are important parameters in geomorphology and hydrology research, because they are related to the amount erosion (and thus the volume of sediments) and the amount of water needed to create the valley. This is not only the case for terrestrial research but also for planetary research as such figuring out how much water was on Mars. With readily available digital elevation model (DEM) data, the Black Top Hat (BTH) transformation, an image processing technique for extracting dark features on a variable background, has been applied to DEM data to extract valley depth and estimate valley volume. However, previous studies typically use one single structuring element size for extracting the valley feature and one single threshold value for removing noise, resulting in some finer features such as tributaries not being extracted and underestimation of valley volume. Inspired by similar algorithms used in LiDAR data analysis to separate above ground features and bare earth topography, here we propose a progressive BTH (PBTH) transformation algorithm, where the structuring elements size is progressively increased to extract valleys of different orders. In addition, a slope based threshold was introduced to automatically adjust the threshold values for structuring elements with different sizes. Connectivity and shape parameters of the masked regions were used to keep the long linear valleys while removing other smaller non-connected regions. Preliminary application of the PBTH to Grand Canyon and two sites on Mars has produced promising results. More testing and fine-tuning is in progress. The ultimate goal of the project is to apply the algorithm to estimate the volume of valley networks on Mars and the volume of water needed to form the valleys we observe today and thus infer the nature of the hydrologic cycle on early Mars. The project is funded by NASA's Mars Data Analysis program.
A progressive black top hat transformation algorithm for estimating valley volumes on Mars
Luo, Wei; Pingel, Thomas; Heo, Joon; Howard, Alan; Jung, Jaehoon
2015-02-01
The depth of valley incision and valley volume are important parameters in understanding the geologic history of early Mars, because they are related to the amount sediments eroded and the quantity of water needed to create the valley networks (VNs). With readily available digital elevation model (DEM) data, the Black Top Hat (BTH) transformation, an image processing technique for extracting dark features on a variable background, has been applied to DEM data to extract valley depth and estimate valley volume. Previous studies typically use a single window size for extracting the valley features and a single threshold value for removing noise, resulting in finer features such as tributaries not being extracted and underestimation of valley volume. Inspired by similar algorithms used in LiDAR data analysis to remove above-ground features to obtain bare-earth topography, here we propose a progressive BTH (PBTH) transformation algorithm, where the window size is progressively increased to extract valleys of different orders. In addition, a slope factor is introduced so that the noise threshold can be automatically adjusted for windows with different sizes. Independently derived VN lines were used to select mask polygons that spatially overlap the VN lines. Volume is calculated as the sum of valley depth within the selected mask multiplied by cell area. Application of the PBTH to a simulated landform (for which the amount of erosion is known) achieved an overall relative accuracy of 96%, in comparison with only 78% for BTH. Application of PBTH to Ma'adim Vallies on Mars not only produced total volume estimates consistent with previous studies, but also revealed the detailed spatial distribution of valley depth. The highly automated PBTH algorithm shows great promise for estimating the volume of VN on Mars on global scale, which is important for understanding its early hydrologic cycle.
Ahteshamul Haque
2016-01-01
The energy crisis concern leads to look for alternate source of energy. Solar energy is considered as most reliable among the all renewable energy sources. Solar PV (Photovoltaic) is used to convert solar energy into electric energy. The efficiency of solar PV is very low and its characteristic is nonlinear. To overcome these drawbacks a technique known as maximum power point tracking is used. This algorithm is implemented in the control circuit of DC – DC converter. The objective...
Park, Seyoun; Robinson, Adam; Quon, Harry; Kiess, Ana P.; Shen, Colette; Wong, John; Plishker, William; Shekhar, Raj; Lee, Junghoon
2016-03-01
In this paper, we propose a CT-CBCT registration method to accurately predict the tumor volume change based on daily cone-beam CTs (CBCTs) during radiotherapy. CBCT is commonly used to reduce patient setup error during radiotherapy, but its poor image quality impedes accurate monitoring of anatomical changes. Although physician's contours drawn on the planning CT can be automatically propagated to daily CBCTs by deformable image registration (DIR), artifacts in CBCT often cause undesirable errors. To improve the accuracy of the registration-based segmentation, we developed a DIR method that iteratively corrects CBCT intensities by local histogram matching. Three popular DIR algorithms (B-spline, demons, and optical flow) with the intensity correction were implemented on a graphics processing unit for efficient computation. We evaluated their performances on six head and neck (HN) cancer cases. For each case, four trained scientists manually contoured the nodal gross tumor volume (GTV) on the planning CT and every other fraction CBCTs to which the propagated GTV contours by DIR were compared. The performance was also compared with commercial image registration software based on conventional mutual information (MI), VelocityAI (Varian Medical Systems Inc.). The volume differences (mean±std in cc) between the average of the manual segmentations and automatic segmentations are 3.70+/-2.30 (B-spline), 1.25+/-1.78 (demons), 0.93+/-1.14 (optical flow), and 4.39+/-3.86 (VelocityAI). The proposed method significantly reduced the estimation error by 9% (B-spline), 38% (demons), and 51% (optical flow) over the results using VelocityAI. Although demonstrated only on HN nodal GTVs, the results imply that the proposed method can produce improved segmentation of other critical structures over conventional methods.
Directory of Open Access Journals (Sweden)
Borui Li
2014-04-01
Full Text Available Traditional object tracking technology usually regards the target as a point source object. However, this approximation is no longer appropriate for tracking extended objects such as large targets and closely spaced group objects. Bayesian extended object tracking (EOT using a random symmetrical positive definite (SPD matrix is a very effective method to jointly estimate the kinematic state and physical extension of the target. The key issue in the application of this random matrix-based EOT approach is to model the physical extension and measurement noise accurately. Model parameter adaptive approaches for both extension dynamic and measurement noise are proposed in this study based on the properties of the SPD matrix to improve the performance of extension estimation. An interacting multi-model algorithm based on model parameter adaptive filter using random matrix is also presented. Simulation results demonstrate the effectiveness of the proposed adaptive approaches and multi-model algorithm. The estimation performance of physical extension is better than the other algorithms, especially when the target maneuvers. The kinematic state estimation error is lower than the others as well.
Automatic LV volume measurement in low dose multi-phase CT by shape tracking
von Berg, Jens; Begemann, Philipp; Stahmer, Felix; Adam, Gerhard; Lorenz, Cristian
2006-03-01
Functional assessment of cardiac ventricular function requires time consuming manual interaction. Some automated methods have been presented that predominantly used cardiac magnet resonance images. Here, an automatic shape tracking approach is followed to estimate left ventricular blood volume from multi-slice computed tomography image series acquired with retrospective ECG-gating. A deformable surface model method was chosen that utilized both shape and local appearance priors to determine the endocardial surface and to follow its motion through the cardiac cycle. Functional parameters like the ejection fraction could be calculated from the estimated shape deformation. A clinical validation was performed in a porcine model with 60 examinations on eight subjects. The functional parameters showed a good correlation with those determined by clinical experts using a commercially available semi-automatic short axes delineation tool. The correlation coefficient for the ejection fraction (EF) was 0.89. One quarter of these acquisitions were done with a low dose protocol. All of these degraded images could be processed well. Their correlation slightly decreases when compared to the normal dose cases (EF: 0.87 versus 0.88).
A High-Order Finite-Volume Algorithm for Fokker-Planck Collisions in Magnetized Plasmas
Energy Technology Data Exchange (ETDEWEB)
Xiong, Z; Cohen, R H; Rognlien, T D; Xu, X Q
2007-04-18
A high-order finite volume algorithm is developed for the Fokker-Planck Operator (FPO) describing Coulomb collisions in strongly magnetized plasmas. The algorithm is based on a general fourth-order reconstruction scheme for an unstructured grid in the velocity space spanned by parallel velocity and magnetic moment. The method provides density conservation and high-order-accurate evaluation of the FPO independent of the choice of the velocity coordinates. As an example, a linearized FPO in constant-of-motion coordinates, i.e. the total energy and the magnetic moment, is developed using the present algorithm combined with a cut-cell merging procedure. Numerical tests include the Spitzer thermalization problem and the return to isotropy for distributions initialized with velocity space loss cones. Utilization of the method for a nonlinear FPO is straightforward but requires evaluation of the Rosenbluth potentials.
A correlation-based algorithm for recognition and tracking of partially occluded objects
Ruchay, Alexey; Kober, Vitaly
2016-09-01
In this work, a correlation-based algorithm consisting of a set of adaptive filters for recognition of occluded objects in still and dynamic scenes in the presence of additive noise is proposed. The designed algorithm is adaptive to the input scene, which may contain different fragments of the target, false objects, and background to be rejected. The algorithm output is high correlation peaks corresponding to pieces of the target in scenes. The proposed algorithm uses a bank of composite optimum filters. The performance of the proposed algorithm for recognition partially occluded objects is compared with that of common algorithms in terms of objective metrics.
Volume reconstruction optimization for tomo-PIV algorithms applied to experimental data
Martins, Fabio J. W. A.; Foucaut, Jean-Marc; Thomas, Lionel; Azevedo, Luis F. A.; Stanislas, Michel
2015-08-01
Tomographic PIV is a three-component volumetric velocity measurement technique based on the tomographic reconstruction of a particle distribution imaged by multiple camera views. In essence, the performance and accuracy of this technique is highly dependent on the parametric adjustment and the reconstruction algorithm used. Although synthetic data have been widely employed to optimize experiments, the resulting reconstructed volumes might not have optimal quality. The purpose of the present study is to offer quality indicators that can be applied to data samples in order to improve the quality of velocity results obtained by the tomo-PIV technique. The methodology proposed can potentially lead to significantly reduction in the time required to optimize a tomo-PIV reconstruction, also leading to better quality velocity results. Tomo-PIV data provided by a six-camera turbulent boundary-layer experiment were used to optimize the reconstruction algorithms according to this methodology. Velocity statistics measurements obtained by optimized BIMART, SMART and MART algorithms were compared with hot-wire anemometer data and velocity measurement uncertainties were computed. Results indicated that BIMART and SMART algorithms produced reconstructed volumes with equivalent quality as the standard MART with the benefit of reduced computational time.
She, Ji; Wang, Fei; Zhou, Jianjiang
2016-12-21
Radar networks are proven to have numerous advantages over traditional monostatic and bistatic radar. With recent developments, radar networks have become an attractive platform due to their low probability of intercept (LPI) performance for target tracking. In this paper, a joint sensor selection and power allocation algorithm for multiple-target tracking in a radar network based on LPI is proposed. It is found that this algorithm can minimize the total transmitted power of a radar network on the basis of a predetermined mutual information (MI) threshold between the target impulse response and the reflected signal. The MI is required by the radar network system to estimate target parameters, and it can be calculated predictively with the estimation of target state. The optimization problem of sensor selection and power allocation, which contains two variables, is non-convex and it can be solved by separating power allocation problem from sensor selection problem. To be specific, the optimization problem of power allocation can be solved by using the bisection method for each sensor selection scheme. Also, the optimization problem of sensor selection can be solved by a lower complexity algorithm based on the allocated powers. According to the simulation results, it can be found that the proposed algorithm can effectively reduce the total transmitted power of a radar network, which can be conducive to improving LPI performance.
Directory of Open Access Journals (Sweden)
P. Li
2017-06-01
Full Text Available Use of the Gaussian inverse Wishart probability hypothesis density (GIW-PHD filter has demonstrated promise as an approach to track an unknown number of extended targets. However, when targets of various sizes are spaced closely together and performing maneuvers, estimation errors will occur because measurement partitioning algorithms fail to provide the correct partitions. Specifically, the sub-partitioning algorithm fails to handle cases in which targets are of different sizes, while other partitioning approaches are sensitive to target maneuvers. This paper presents an improved partitioning algorithm for a GIW-PHD filter in order to solve the above problems. The sub-partitioning algorithm is improved by considering target extension information and by employing Mahalanobis distances to distinguish among measurement cells of different sizes. Thus, the improved approach is not sensitive to either differences in target sizes or target maneuvering. Simulation results show that the use of the proposed partitioning approach can improve the tracking performance of a GIW-PHD filter when target are spaced closely together.
Afik, Eldad
2013-01-01
Three-dimensional particle tracking is an essential tool in studying dynamics under the microscope, namely, cellular trafficking, bacteria taxis, fluid dynamics in microfluidics devices. The 3d position of a fluorescent particle can be determined using 2d imaging alone, by measuring the diffraction rings generated by an out-of-focus particle, imaged on a single camera. Here I present a ring detection algorithm exhibiting a high detection rate, which is robust to the challenges arising from particles vicinity. It is capable of real time analysis thanks to its high performance and low memory footprint. Many of the algorithmic concepts introduced can be advantageous in other cases, particularly for sparse data. The implementation is based on open-source and cross-platform software packages only, making it easy to distribute and modify. The image analysis algorithm, which is an offspring of the full 3d circle Hough transform, addresses the need to efficiently trace the trajectories of several particles concurrent...
Li, Xiao-Dong; Lv, Mang-Mang; Ho, John K. L.
2016-07-01
In this article, two adaptive iterative learning control (ILC) algorithms are presented for nonlinear continuous systems with non-parametric uncertainties. Unlike general ILC techniques, the proposed adaptive ILC algorithms allow that both the initial error at each iteration and the reference trajectory are iteration-varying in the ILC process, and can achieve non-repetitive trajectory tracking beyond a small initial time interval. Compared to the neural network or fuzzy system-based adaptive ILC schemes and the classical ILC methods, in which the number of iterative variables is generally larger than or equal to the number of control inputs, the first adaptive ILC algorithm proposed in this paper uses just two iterative variables, while the second even uses a single iterative variable provided that some bound information on system dynamics is known. As a result, the memory space in real-time ILC implementations is greatly reduced.
Performance comparison of 2D assignment algorithms for assigning truth objects to measured tracks
Levedahl, Mark
2000-07-01
The processing time requirements of several algorithms for solving the 2-d (also called single frame) linear assignment problem are compared, along with their accuracy given either random or biased measurement errors. The specific problem considered is that of assigning measurements to truth objects using costs that are the chi-squared distances between them. Performance comparisons are provided for the algorithms implemented both in a compiled language C or FORTRAN) as well as the interpretive MatLab language. Accuracy considerations show optimal assignment algorithm is preferred if biased measurement errors are present. The Jonker-Volgenant-Castanon (JVC) algorithm is the preferred approach considering both average and maximum solution time. The Auction algorithm finds favor due to being both efficient as well as easy to understand, but is never faster and often much slower than the JVC algorithm. Both algorithms are dramatically faster than the Munkres algorithm. The greedy nearest neighbor algorithm is an ad hoc solution to provide a sub-optimal but unique solution more cheaply than the optimal assignment algorithms. However, the JVC algorithm is as fast as the greedy for simple problems, marginally slower at hard problems, and is vastly more accurate in the presence of measurement biases.
Cieri, Davide
2016-01-01
At the HL-LHC, proton bunches collide every 25\\,ns, producing an average of 140 pp interactions per bunch crossing. To operate in such an environment, the CMS experiment will need a Level-1 (L1) hardware trigger, able to identify interesting events within a latency of 12.5\\,$\\mu$s. This novel L1 trigger will make use of data coming from the silicon tracker to constrain the trigger rate. Goal of this new \\textit{track trigger} will be to build L1 tracks from the tracker information. The architecture that will be implemented in future to process tracker data is still under discussion. One possibility is to adopt a system entirely based on FPGA electronic. The proposed track finding algorithm is based on the Hough transform method. The algorithm has been tested using simulated pp collision data and it is currently being demonstrated in hardware, using the ``MP7'', which is a $\\mu$TCA board with a powerful FPGA capable of handling data rates approaching 1 Tb/s. Two different implementations of the Hough tran...
Cieri, D.; CMS Collaboration; of the Time Multiplexed Track Trigger Group
2016-10-01
At the HL-LHC, proton bunches collide every 25 ns, producing an average of 140 pp interactions per bunch crossing. To operate in such an environment, the CMS experiment will need a Level-1 (L1) hardware trigger, able to identify interesting events within a latency of 12.5 μs. This novel L1 trigger will make use of data coming from the silicon tracker to constrain the trigger rate. Goal of this new track trigger will be to build L1 tracks from the tracker information. The architecture that will be implemented in future to process tracker data is still under discussion. One possibility is to adopt a system entirely based on FPGA electronic. The proposed track finding algorithm is based on the Hough transform method. The algorithm has been tested using simulated pp collision data and it is currently being demonstrated in hardware, using the “MP7”, which is a μTCA board with a powerful FPGA capable of handling data rates approaching 1 Tb/s. Two different implementations of the Hough transform technique are currently under investigation: one utilizes a systolic array to represent the Hough space, while the other exploits a pipelined approach.
AUTHOR|(CDS)2090481
2016-01-01
At the HL-LHC, proton bunches collide every 25\\,ns, producing an average of 140 pp interactions per bunch crossing. To operate in such an environment, the CMS experiment will need a Level-1 (L1) hardware trigger, able to identify interesting events within a latency of 12.5\\,$\\mu$s. This novel L1 trigger will make use of data coming from the silicon tracker to constrain the trigger rate. Goal of this new \\textit{track trigger} will be to build L1 tracks from the tracker information. The architecture that will be implemented in future to process tracker data is still under discussion. One possibility is to adopt a system entirely based on FPGA electronic. The proposed track finding algorithm is based on the Hough transform method. The algorithm has been tested using simulated pp collision data and it is currently being demonstrated in hardware, using the ``MP7'', which is a $\\mu$TCA board with a powerful FPGA capable of handling data rates approaching 1 Tb/s. Two different implementations of the Hough tran...
Numerical methods and inversion algorithms in reservoir simulation based on front tracking
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Haugse, Vidar
1999-04-01
This thesis uses front tracking to analyse laboratory experiments on multiphase flow in porous media. New methods for parameter estimation for two- and three-phase relative permeability experiments have been developed. Up scaling of heterogeneous and stochastic porous media is analysed. Numerical methods based on front tracking is developed and analysed. Such methods are efficient for problems involving steep changes in the physical quantities. Multi-dimensional problems are solved by combining front tracking with dimensional splitting. A method for adaptive grid refinement is developed.
Tracking magma volume recovery at okmok volcano using GPS and an unscented kalman filter
Fournier, T.; Freymueller, Jeffrey T.; Cervelli, Peter
2009-01-01
Changes beneath a volcano can be observed through position changes in a GPS network, but distinguishing the source of site motion is not always straightforward. The records of continuous GPS sites provide a favorable data set for tracking magma migration. Dense campaign observations usually provide a better spatial picture of the overall deformation field, at the expense of an episodic temporal record. Combining these observations provides the best of both worlds. A Kalman filter provides a means for integrating discrete and continuous measurements and for interpreting subtle signals. The unscented Kalman filter (UKF) is a nonlinear method for time-dependent observations. We demonstrate the application of this technique to deformation data by applying it to GPS data collected at Okmok volcano. Seven years of GPS observations at Okmok are analyzed using a Mogi source model and the UKF. The deformation source at Okmok is relatively stable at 2.5 km depth below sea level, located beneath the center of the caldera, which means the surface deformation is caused by changes in the strength of the source. During the 7 years of GPS observations more than 0.5 m of uplift has occurred, a majority of that during the time period January 2003 to July 2004. The total volume recovery at Okmok since the last eruption in 1997 is ??60-80%. The UKF allows us to solve simultaneously for the time-dependence of the source strength and for the location without a priori information about the source. ?? 2009 by the American Geophysical Union.
Li, Hao; Lu, Jing; Shi, Guohua; Zhang, Yudong
2010-06-28
With the use of adaptive optics (AO), high-resolution microscopic imaging of living human retina in the single cell level has been achieved. In an adaptive optics confocal scanning laser ophthalmoscope (AOSLO) system, with a small field size (about 1 degree, 280 μm), the motion of the eye severely affects the stabilization of the real-time video images and results in significant distortions of the retina images. In this paper, Scale-Invariant Feature Transform (SIFT) is used to abstract stable point features from the retina images. Kanade-Lucas-Tomasi(KLT) algorithm is applied to track the features. With the tracked features, the image distortion in each frame is removed by the second-order polynomial transformation, and 10 successive frames are co-added to enhance the image quality. Features of special interest in an image can also be selected manually and tracked by KLT. A point on a cone is selected manually, and the cone is tracked from frame to frame.
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Wen-Chang Cheng
2012-12-01
Full Text Available In this paper we propose a robust lane detection and tracking method by combining particle filters with the particle swarm optimization method. This method mainly uses the particle filters to detect and track the local optimum of the lane model in the input image and then seeks the global optimal solution of the lane model by a particle swarm optimization method. The particle filter can effectively complete lane detection and tracking in complicated or variable lane environments. However, the result obtained is usually a local optimal system status rather than the global optimal system status. Thus, the particle swarm optimization method is used to further refine the global optimal system status in all system statuses. Since the particle swarm optimization method is a global optimization algorithm based on iterative computing, it can find the global optimal lane model by simulating the food finding way of fish school or insects under the mutual cooperation of all particles. In verification testing, the test environments included highways and ordinary roads as well as straight and curved lanes, uphill and downhill lanes, lane changes, etc. Our proposed method can complete the lane detection and tracking more accurately and effectively then existing options.
A Comparison of Evolutionary Algorithms for Tracking Time-Varying Recursive Systems
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White Michael S
2003-01-01
Full Text Available A comparison is made of the behaviour of some evolutionary algorithms in time-varying adaptive recursive filter systems. Simulations show that an algorithm including random immigrants outperforms a more conventional algorithm using the breeder genetic algorithm as the mutation operator when the time variation is discontinuous, but neither algorithm performs well when the time variation is rapid but smooth. To meet this deficit, a new hybrid algorithm which uses a hill climber as an additional genetic operator, applied for several steps at each generation, is introduced. A comparison is made of the effect of applying the hill climbing operator a few times to all members of the population or a larger number of times solely to the best individual; it is found that applying to the whole population yields the better results, substantially improved compared with those obtained using earlier methods.
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Ćosić Aleksandar
2012-01-01
Full Text Available An approach to intelligent robot motion planning and tracking in known and static environments is presented in this paper. This complex problem is divided into several simpler problems. The first is generation of a collision free path from starting to destination point, which is solved using a particle swarm optimization (PSO algorithm. The second is interpolation of the obtained collision-free path, which is solved using a radial basis function neural network (RBFNN, and trajectory generation, based on the interpolated path. The last is a trajectory tracking problem, which is solved using a proportional-integral (PI controller. Due to uncertainties, obstacle avoidance is still not ensured, so an additional fuzzy controller is introduced, which corrects the control action of the PI controller. The proposed solution can be used even in dynamic environments, where obstacles change their position in time. Simulation studies were realized to validate and illustrate this approach.
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Yasir Khudhair Abbas
2012-01-01
Full Text Available In this paper, an intelligent tracking control system of both single- and double-axis Piezoelectric Micropositioner stage is designed using Genetic Algorithms (GAs method for the optimal Proportional-Integral-Derivative (PID controller tuning parameters. The (GA-based PID control design approach is a methodology to tune a (PID controller in an optimal control sense with respect to specified objective function. By using the (GA-based PID control approach, the high-performance trajectory tracking responses of the Piezoelectric Micropositioner stage can be obtained. The (GA code was built and the simulation results were obtained using MATLAB environment. The Piezoelectric Micropositioner simulation model with the (GA-based PID control is illustrated to show the validity of the proposed control method for practical applications, such as scanning microscopy.
Applications of a finite-volume algorithm for incompressible MHD problems
Vantieghem, S; Jackson, A
2016-01-01
We present the theory, algorithms and implementation of a parallel finite-volume algorithm for the solution of the incompressible magnetohydrodynamic (MHD) equations using unstructured grids that are applicable for a wide variety of geometries. Our method implements a mixed Adams-Bashforth/Crank-Nicolson scheme for the nonlinear terms in the MHD equations and we prove that it is stable independent of the time step. To ensure that the solenoidal condition is met for the magnetic field, we use a method whereby a pseudo-pressure is introduced into the induction equation; since we are concerned with incompressible flows, the resulting Poisson equation for the pseudo-pressure is solved alongside the equivalent Poisson problem for the velocity field. We validate our code in a variety of geometries including periodic boxes, spheres, spherical shells, spheroids and ellipsoids; for the finite geometries we implement the so-called ferromagnetic or pseudo-vacuum boundary conditions appropriate for a surrounding medium w...
Fluck, Elody
2015-04-01
Hail statistic in Western Europe based on a hybrid cell-tracking algorithm combining radar signals with hailstone observations Elody Fluck¹, Michael Kunz¹ , Peter Geissbühler², Stefan P. Ritz² With hail damage estimated over Billions of Euros for a single event (e.g., hailstorm Andreas on 27/28 July 2013), hail constitute one of the major atmospheric risks in various parts of Europe. The project HAMLET (Hail Model for Europe) in cooperation with the insurance company Tokio Millennium Re aims at estimating hail probability, hail hazard and, combined with vulnerability, hail risk for several European countries (Germany, Switzerland, France, Netherlands, Austria, Belgium and Luxembourg). Hail signals are obtained from radar reflectivity since this proxy is available with a high temporal and spatial resolution using several hail proxies, especially radar data. The focus in the first step is on Germany and France for the periods 2005- 2013 and 1999 - 2013, respectively. In the next step, the methods will be transferred and extended to other regions. A cell-tracking algorithm TRACE2D was adjusted and applied to two dimensional radar reflectivity data from different radars operated by European weather services such as German weather service (DWD) and French weather service (Météo-France). Strong convective cells are detected by considering 3 connected pixels over 45 dBZ (Reflectivity Cores RCs) in a radar scan. Afterwards, the algorithm tries to find the same RCs in the next 5 minute radar scan and, thus, track the RCs centers over time and space. Additional information about hailstone diameters provided by ESWD (European Severe Weather Database) is used to determine hail intensity of the detected hail swaths. Maximum hailstone diameters are interpolated along and close to the individual hail tracks giving an estimation of mean diameters for the detected hail swaths. Furthermore, a stochastic event set is created by randomizing the parameters obtained from the
Pommer, Tobias; Falk, Marianne; Poulsen, Per R.; Keall, Paul J.; O’Brien, Ricky T.; Petersen, Peter Meidahl; Rosenschöld, Per Munck af
2013-01-01
This study investigated the dosimetric impact of uncompensated motion and motion compensation with dynamic multileaf collimator (DMLC) tracking for prostate intensity modulated arc therapy. Two treatment approaches were investigated; a conventional approach with a uniform radiation dose to the target volume and an intraprostatic lesion (IPL) boosted approach with an increased dose to a subvolume of the prostate. The impact on plan quality of optimizations with a leaf position constraint, which limited the distance between neighbouring adjacent MLC leaves, was also investigated. Deliveries were done with and without DMLC tracking on a linear acceleration with a high-resolution MLC. A cylindrical phantom containing two orthogonal diode arrays was used for dosimetry. A motion platform reproduced six patient-derived prostate motion traces, with the average displacement ranging from 1.0 to 8.9 mm during the first 75 seconds. A research DMLC tracking system was used for real-time motion compensation with optical monitoring for position input. The gamma index was used for evaluation, with measurements with a static phantom or the planned dose as reference, using 2% and 2 mm gamma criteria. The average pass rate with DMLC tracking was 99.9% (range 98.7–100%, measurement as reference), whereas the pass rate for untracked deliveries decreased distinctly as the average displacement increased, with an average pass rate of 61.3% (range 32.7–99.3%). Dose-volume histograms showed that DMLC tracking maintained the planned dose distributions in the presence of motion whereas traces with > 3 mm average displacement caused clear plan degradation for untracked deliveries. The dose to the rectum and bladder had an evident dependence on the motion direction and amplitude for untracked deliveries, and the dose to the rectum was slightly increased for IPL boosted plans compared to conventional plans for anterior motion with large amplitude. In conclusion, optimization using a leaf
基于视频图像的眼动追踪系统算法%Eye Tracking System Algorithm Based on Video Image Algorithm
Institute of Scientific and Technical Information of China (English)
王际航; 刘富; 袁雨桐; 刘星
2016-01-01
In order to solve the problem of eye tracking,we put forward a fast real-time algorithm of eye tracking based on video image. Firstly,convert RGB color space to YCbCr space,and locate human faces by skin color model. After clipping,use Sobel operator edge detection algorithm in convolution processing,and then find the approximate location of eyes through horizontal gray-level projection to determine rough location of the eyes. Divide this area into left and right eye areas with the help of gray-scale projection,then respectively locate the left and right eye,finally get the precise localization of human eyes. Based on the algorithm,we got the results based on video sequence.%为了解决初步眼动追踪问题，提出基于视频图像的实时性眼动追踪的快速算法。将RGB色彩空间转换成YCbCr空间，利用肤色模型定位人脸。剪裁后，用Sobel算子边缘检测算法进行卷积处理，对图像进行水平投影找到人眼大致位置，对眼部进行粗定位。对该区域进行灰度投影，分割左、右眼，再分别对左、右眼进行定位，从而得到人眼的精确定位。实验选取15帧图片作为测试视频序列，其结果表明，该算法准确地解决了眼动追踪问题，满足实时性要求。
Zhang, Huaguang; Wei, Qinglai; Luo, Yanhong
2008-08-01
In this paper, we aim to solve the infinite-time optimal tracking control problem for a class of discrete-time nonlinear systems using the greedy heuristic dynamic programming (HDP) iteration algorithm. A new type of performance index is defined because the existing performance indexes are very difficult in solving this kind of tracking problem, if not impossible. Via system transformation, the optimal tracking problem is transformed into an optimal regulation problem, and then, the greedy HDP iteration algorithm is introduced to deal with the regulation problem with rigorous convergence analysis. Three neural networks are used to approximate the performance index, compute the optimal control policy, and model the nonlinear system for facilitating the implementation of the greedy HDP iteration algorithm. An example is given to demonstrate the validity of the proposed optimal tracking control scheme.
Fröberg, Åsa; Mårtensson, Mattias; Larsson, Matilda; Janerot-Sjöberg, Birgitta; D'Hooge, Jan; Arndt, Anton
2016-10-01
Ultrasound speckle tracking offers a non-invasive way of studying strain in the free Achilles tendon where no anatomical landmarks are available for tracking. This provides new possibilities for studying injury mechanisms during sport activity and the effects of shoes, orthotic devices, and rehabilitation protocols on tendon biomechanics. To investigate the feasibility of using a commercial ultrasound speckle tracking algorithm for assessing strain in tendon tissue. A polyvinyl alcohol (PVA) phantom, three porcine tendons, and a human Achilles tendon were mounted in a materials testing machine and loaded to 4% peak strain. Ultrasound long-axis cine-loops of the samples were recorded. Speckle tracking analysis of axial strain was performed using a commercial speckle tracking software. Estimated strain was then compared to reference strain known from the materials testing machine. Two frame rates and two region of interest (ROI) sizes were evaluated. Best agreement between estimated strain and reference strain was found in the PVA phantom (absolute error in peak strain: 0.21 ± 0.08%). The absolute error in peak strain varied between 0.72 ± 0.65% and 10.64 ± 3.40% in the different tendon samples. Strain determined with a frame rate of 39.4 Hz had lower errors than 78.6 Hz as was the case with a 22 mm compared to an 11 mm ROI. Errors in peak strain estimation showed high variability between tendon samples and were large in relation to strain levels previously described in the Achilles tendon. © The Foundation Acta Radiologica 2016.
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Joko Siswantoro
2014-11-01
Full Text Available Volume is one of important issues in the production and processing of food product. Traditionally, volume measurement can be performed using water displacement method based on Archimedes’ principle. Water displacement method is inaccurate and considered as destructive method. Computer vision offers an accurate and nondestructive method in measuring volume of food product. This paper proposes algorithm for volume measurement of irregular shape food product using computer vision based on Monte Carlo method. Five images of object were acquired from five different views and then processed to obtain the silhouettes of object. From the silhouettes of object, Monte Carlo method was performed to approximate the volume of object. The simulation result shows that the algorithm produced high accuracy and precision for volume measurement.
Huang, Yu
Solar energy becomes one of the major alternative renewable energy options for its huge abundance and accessibility. Due to the intermittent nature, the high demand of Maximum Power Point Tracking (MPPT) techniques exists when a Photovoltaic (PV) system is used to extract energy from the sunlight. This thesis proposed an advanced Perturbation and Observation (P&O) algorithm aiming for relatively practical circumstances. Firstly, a practical PV system model is studied with determining the series and shunt resistances which are neglected in some research. Moreover, in this proposed algorithm, the duty ratio of a boost DC-DC converter is the object of the perturbation deploying input impedance conversion to achieve working voltage adjustment. Based on the control strategy, the adaptive duty ratio step size P&O algorithm is proposed with major modifications made for sharp insolation change as well as low insolation scenarios. Matlab/Simulink simulation for PV model, boost converter control strategy and various MPPT process is conducted step by step. The proposed adaptive P&O algorithm is validated by the simulation results and detail analysis of sharp insolation changes, low insolation condition and continuous insolation variation.
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Pina, Jorge Luiz Soares de; Mello, Rossana Corbo de; Rebelo, Ana Maria [Hospital Universitario Clementino Fraga Filho, Rio de Janeiro, RJ (Brazil). Dept. de Radiologia
2000-07-01
An algorithm was developed to estimate the volume of the thyroid and its functioning lesions, that is, those which capture iodine. This estimate is achieved by the use of SPECT, Single Photon Emission Computed Tomography. The algorithm was written in an extended PASCAL language subset and was accomplished to run on Siemens ICON System, a special Macintosh environment that controls the tomographic image acquisition and processing. In spite of be developed for the Siemens DIACAN gamma camera, the algorithm can be easily adapted for the ECAN camera. These two Cameras models are among the most common ones used in Nuclear Medicine in Brazil Nowadays. A phantom study was used to validate the algorithm that have shown that a threshold of 42% of maximum pixel intensity of the images it is possible to estimate the volume of the phantoms with an error of 10% in the range of 30 to 70 ml. (author)
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Arheden Håkan
2011-04-01
Full Text Available Abstract Background Functional and morphological changes of the heart influence blood flow patterns. Therefore, flow patterns may carry diagnostic and prognostic information. Three-dimensional, time-resolved, three-directional phase contrast cardiovascular magnetic resonance (4D PC-CMR can image flow patterns with unique detail, and using new flow visualization methods may lead to new insights. The aim of this study is to present and validate a novel visualization method with a quantitative potential for blood flow from 4D PC-CMR, called Volume Tracking, and investigate if Volume Tracking complements particle tracing, the most common visualization method used today. Methods Eight healthy volunteers and one patient with a large apical left ventricular aneurysm underwent 4D PC-CMR flow imaging of the whole heart. Volume Tracking and particle tracing visualizations were compared visually side-by-side in a visualization software package. To validate Volume Tracking, the number of particle traces that agreed with the Volume Tracking visualizations was counted and expressed as a percentage of total released particles in mid-diastole and end-diastole respectively. Two independent observers described blood flow patterns in the left ventricle using Volume Tracking visualizations. Results Volume Tracking was feasible in all eight healthy volunteers and in the patient. Visually, Volume Tracking and particle tracing are complementary methods, showing different aspects of the flow. When validated against particle tracing, on average 90.5% and 87.8% of the particles agreed with the Volume Tracking surface in mid-diastole and end-diastole respectively. Inflow patterns in the left ventricle varied between the subjects, with excellent agreement between observers. The left ventricular inflow pattern in the patient differed from the healthy subjects. Conclusion Volume Tracking is a new visualization method for blood flow measured by 4D PC-CMR. Volume Tracking
Control Algorithms for a Shape-shifting Tracked Robotic Vehicle Climbing Obstacles
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
基于Gabor变换的快速跟踪算法%Fast tracking algorithm based on Gabor transformation
Institute of Scientific and Technical Information of China (English)
徐天阳; 吴小俊
2016-01-01
In order to enhance the speed and accuracy of object tracking, a fast tracking algorithm based on Gabor trans-formation is proposed. According to the good simulation capability of Gabor transformation to human visual receptive field, the proposed algorithm extracts features via multi-scale and multi-orientation Gabor filters, and then realizes track-ing by utilizing image matching between target model and candidates. At the feature extracting stage, a multi-channel model is used to fuse Gabor features. And at the output stage, convolution property in spatial-frequency domain is exploited to realize fast posterior distribution computation. Experimental results indicate that the proposed algorithm has good prop-erties in accuracy and speed, and outperforms state-of-the-art methods.%为了增强目标跟踪的速度和精度，提出了一种基于Gabor变换的快速跟踪算法。根据Gabor变换对人类视觉感受野良好的模拟能力，用多尺度多方向的Gabor滤波器对目标图像进行特征抽取，以此建立目标的表观模型，而后利用图像匹配的方法得到相邻帧目标位置的后验概率分布从而实现跟踪。其中在特征抽取级利用线性多通道模型将不同尺度和方向的Gabor特征融合起来，在输出级利用时频的卷积特性以FFT实现相邻帧目标位置后验概率的快速计算，充分考虑了跟踪的速度和精度。实验结果表明，该算法选用的Gabor特征对目标有准确的描述能力，以此建立的表观模型鲁棒性强；同时跟踪过程简单快速，在精度和速度上与其他前沿的跟踪算法相较有优越性。
PERFORMANCE MEASUREMENTS OF FEATURE TRACKING AND HISTOGRAM BASED TRAFFIC CONGESTION ALGORITHMS
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Ozgur Altun
2015-05-01
Full Text Available In this paper, feature tracking based and histogram based traffic congestion detection systems are developed. Developed all system are designed to run as real time application. In this work, ORB (Oriented FAST and Rotated BRIEF feature extraction method have been used to develop feature tracking based traffic congestion solution. ORB is a rotation invariant, fast and resistant to noise method and contains the power of FAST and BRIEF feature extraction methods. Also, two different approaches, which are standard deviation and weighed average, have been applied to find out the congestion information by using histogram of the image to develop histogram based traffic congestion solution. Both systems have been tested on different weather conditions such as cloudy, sunny and rainy to provide various illumination at both daytime and night. For all developed systems performance results are examined to show the advantages and drawbacks of these systems
Human body motion tracking based on quantum-inspired immune cloning algorithm
Han, Hong; Yue, Lichuan; Jiao, Licheng; Wu, Xing
2009-10-01
In a static monocular camera system, to gain a perfect 3D human body posture is a great challenge for Computer Vision technology now. This paper presented human postures recognition from video sequences using the Quantum-Inspired Immune Cloning Algorithm (QICA). The algorithm included three parts. Firstly, prior knowledge of human beings was used, the key joint points of human could be detected automatically from the human contours and skeletons which could be thinning from the contours; And due to the complexity of human movement, a forecasting mechanism of occlusion joint points was addressed to get optimum 2D key joint points of human body; And then pose estimation recovered by optimizing between the 2D projection of 3D human key joint points and 2D detection key joint points using QICA, which recovered the movement of human body perfectly, because this algorithm could acquire not only the global optimal solution, but the local optimal solution.
Performance of the ATLAS Track Reconstruction Algorithms in Dense Environments in LHC run 2
Aaboud, Morad; ATLAS Collaboration; Abbott, Brad; Abdallah, Jalal; Abdinov, Ovsat; Abeloos, Baptiste; Abidi, Syed Haider; AbouZeid, Ossama; Abraham, Nicola; Abramowicz, Halina; Abreu, Henso; Abreu, Ricardo; Abulaiti, Yiming; Acharya, Bobby Samir; Adachi, Shunsuke; Adamczyk, Leszek; Adelman, Jahred; Adersberger, Michael; Adye, Tim; Affolder, Tony; Agatonovic-Jovin, Tatjana; Agheorghiesei, Catalin; Aguilar-Saavedra, Juan Antonio; Ahlen, Steven; Ahmadov, Faig; Aielli, Giulio; Akatsuka, Shunichi; Akerstedt, Henrik; Åkesson, Torsten Paul Ake; Akimov, Andrei; Alberghi, Gian Luigi; Albert, Justin; Albicocco, Pietro; Alconada Verzini, Maria Josefina; Aleksa, Martin; Aleksandrov, Igor; Alexa, Calin; Alexander, Gideon; Alexopoulos, Theodoros; Alhroob, Muhammad; Ali, Babar; Aliev, Malik; Alimonti, Gianluca; Alison, John; Alkire, Steven Patrick; Allbrooke, Benedict; Allen, Benjamin William; Allport, Phillip; Aloisio, Alberto; Alonso, Alejandro; Alonso, Francisco; Alpigiani, Cristiano; Alshehri, Azzah Aziz; Alstaty, Mahmoud; Alvarez Gonzalez, Barbara; Άlvarez Piqueras, Damián; Alviggi, Mariagrazia; Amadio, Brian Thomas; Amaral Coutinho, Yara; Amelung, Christoph; Amidei, Dante; Amor Dos Santos, Susana Patricia; Amorim, Antonio; Amoroso, Simone; Amundsen, Glenn; Anastopoulos, Christos; Ancu, Lucian Stefan; Andari, Nansi; Andeen, Timothy; Anders, Christoph Falk; Anders, John Kenneth; Anderson, Kelby; Andreazza, Attilio; Andrei, George Victor; Angelidakis, Stylianos; Angelozzi, Ivan; Angerami, Aaron; Anisenkov, Alexey; Anjos, Nuno; Annovi, Alberto; Antel, Claire; Antonelli, Mario; Antonov, Alexey; Antrim, Daniel Joseph; Anulli, Fabio; Aoki, Masato; Aperio Bella, Ludovica; Arabidze, Giorgi; Arai, Yasuo; Araque, Juan Pedro; Araujo Ferraz, Victor; Arce, Ayana; Ardell, Rose Elisabeth; Arduh, Francisco Anuar; Arguin, Jean-Francois; Argyropoulos, Spyridon; Arik, Metin; Armbruster, Aaron James; Armitage, Lewis James; Arnaez, Olivier; Arnold, Hannah; Arratia, Miguel; Arslan, Ozan; Artamonov, Andrei; Artoni, Giacomo; Artz, Sebastian; Asai, Shoji; Asbah, Nedaa; Ashkenazi, Adi; Asquith, Lily; Assamagan, Ketevi; Astalos, Robert; Atkinson, Markus; Atlay, Naim Bora; Augsten, Kamil; Avolio, Giuseppe; Axen, Bradley; Ayoub, Mohamad Kassem; Azuelos, Georges; Baas, Alessandra; Baca, Matthew John; Bachacou, Henri; Bachas, Konstantinos; Backes, Moritz; Backhaus, Malte; Bagnaia, Paolo; Bahrasemani, Sina; Baines, John; Bajic, Milena; Baker, Oliver Keith; Baldin, Evgenii; Balek, Petr; Balli, Fabrice; Balunas, William Keaton; Banas, Elzbieta; Banerjee, Swagato; Bannoura, Arwa A E; Barak, Liron; Barberio, Elisabetta Luigia; Barberis, Dario; Barbero, Marlon; Barillari, Teresa; Barisits, Martin-Stefan; Barklow, Timothy; Barlow, Nick; Barnes, Sarah Louise; Barnett, Bruce; Barnett, Michael; Barnovska-Blenessy, Zuzana; Baroncelli, Antonio; Barone, Gaetano; Barr, Alan; Barranco Navarro, Laura; Barreiro, Fernando; Barreiro Guimarães da Costa, João; Bartoldus, Rainer; Barton, Adam Edward; Bartos, Pavol; Basalaev, Artem; Bassalat, Ahmed; Bates, Richard; Batista, Santiago Juan; Batley, Richard; Battaglia, Marco; Bauce, Matteo; Bauer, Florian; Bawa, Harinder Singh; Beacham, James; Beattie, Michael David; Beau, Tristan; Beauchemin, Pierre-Hugues; Bechtle, Philip; Beck, Hans~Peter; Becker, Kathrin; Becker, Maurice; Beckingham, Matthew; Becot, Cyril; Beddall, Andrew; Beddall, Ayda; Bednyakov, Vadim; Bedognetti, Matteo; Bee, Christopher; Beermann, Thomas; Begalli, Marcia; Begel, Michael; Behr, Janna Katharina; Bell, Andrew Stuart; Bella, Gideon; Bellagamba, Lorenzo; Bellerive, Alain; Bellomo, Massimiliano; Belotskiy, Konstantin; Beltramello, Olga; Belyaev, Nikita; Benary, Odette; Benchekroun, Driss; Bender, Michael; Bendtz, Katarina; Benekos, Nektarios; Benhammou, Yan; Benhar Noccioli, Eleonora; Benitez, Jose; Benjamin, Douglas; Benoit, Mathieu; Bensinger, James; Bentvelsen, Stan; Beresford, Lydia; Beretta, Matteo; Berge, David; Bergeaas Kuutmann, Elin; Berger, Nicolas; Beringer, Jürg; Berlendis, Simon; Bernard, Nathan Rogers; Bernardi, Gregorio; Bernius, Catrin; Bernlochner, Florian Urs; Berry, Tracey; Berta, Peter; Bertella, Claudia; Bertoli, Gabriele; Bertolucci, Federico; Bertram, Iain Alexander; Bertsche, Carolyn; Bertsche, David; Besjes, Geert-Jan; Bessidskaia Bylund, Olga; Bessner, Martin Florian; Besson, Nathalie; Betancourt, Christopher; Bethani, Agni; Bethke, Siegfried; Bevan, Adrian John; Beyer, Julien-christopher; Bianchi, Riccardo-Maria; Biebel, Otmar; Biedermann, Dustin; Bielski, Rafal; Biesuz, Nicolo Vladi; Biglietti, Michela
2017-01-01
Abstract: With the increase in energy of the Large Hadron Collider to a centre-of-mass energy of 13 TeV for Run 2, events with dense environments, such as in the cores of high-energy jets, became a focus for new physics searches as well as measurements of the Standard Model. These environments are characterized by charged-particle separations of the order of the tracking detectors sensor granularity. Basic track quantities are compared between 3.2 fb$^{-1}$ of data collected by the ATLAS experiment and simulation of proton-proton collisions producing high-transverse-momentum jets at a centre-of-mass energy of 13 TeV. The impact of charged-particle separations and multiplicities on the track reconstruction performance is discussed. The efficiency in the cores of jets with transverse momenta between 200 GeV and 1600 GeV is quantified using a novel, data-driven, method. The method uses the energy loss, dE/dx, to identify pixel clusters originating from two charged particles. Of the charged particles creating the...
Hilgers, G.; Bug, M. U.; Rabus, H.
2017-10-01
Ionization cluster size distributions produced in the sensitive volume of an ion-counting wall-less nanodosimeter by monoenergetic carbon ions with energies between 45 MeV and 150 MeV were measured at the TANDEM-ALPI ion accelerator facility complex of the LNL-INFN in Legnaro. Those produced by monoenergetic helium ions with energies between 2 MeV and 20 MeV were measured at the accelerator facilities of PTB and with a 241Am alpha particle source. C3H8 was used as the target gas. The ionization cluster size distributions were measured in narrow beam geometry with the primary beam passing the target volume at specified distances from its centre, and in broad beam geometry with a fan-like primary beam. By applying a suitable drift time window, the effective size of the target volume was adjusted to match the size of a DNA segment. The measured data were compared with the results of simulations obtained with the PTB Monte Carlo code PTra. Before the comparison, the simulated cluster size distributions were corrected with respect to the background of additional ionizations produced in the transport system of the ionized target gas molecules. Measured and simulated characteristics of the particle track structure are in good agreement for both types of primary particles and for both types of the irradiation geometry. As the range in tissue of the ions investigated is within the typical extension of a spread-out Bragg peak, these data are useful for benchmarking not only ‘general purpose’ track structure simulation codes, but also treatment planning codes used in hadron therapy. Additionally, these data sets may serve as a data base for codes modelling the induction of radiation damages at the DNA-level as they almost completely characterize the ionization component of the nanometric track structure.
Directory of Open Access Journals (Sweden)
Yibo Feng
2015-05-01
Full Text Available We present an adaptive algorithm for a system integrated with micro-electro-mechanical systems (MEMS gyroscopes and a compass to eliminate the influence from the environment, compensate the temperature drift precisely, and improve the accuracy of the MEMS gyroscope. We use a simplified drift model and changing but appropriate model parameters to implement this algorithm. The model of MEMS gyroscope temperature drift is constructed mostly on the basis of the temperature sensitivity of the gyroscope. As the state variables of a strong tracking Kalman filter (STKF, the parameters of the temperature drift model can be calculated to adapt to the environment under the support of the compass. These parameters change intelligently with the environment to maintain the precision of the MEMS gyroscope in the changing temperature. The heading error is less than 0.6° in the static temperature experiment, and also is kept in the range from 5° to −2° in the dynamic outdoor experiment. This demonstrates that the proposed algorithm exhibits strong adaptability to a changing temperature, and performs significantly better than KF and MLR to compensate the temperature drift of a gyroscope and eliminate the influence of temperature variation.
Directory of Open Access Journals (Sweden)
M. Truijens
2014-01-01
Full Text Available High accuracy of construction materials tracking with radio frequency identification technology (RFID is challenging to achieve. The microzoning method consists essentially of an absolute received signal strength indication (RSSI positioning algorithm on the basis of measuring the distance of tag from antennas base. In this paper, we analyse and examine the effects of microzoning method on the performance of RFID tags. A system was set up whereby RFID tags and antennas with the microzoning method were developed and studied. The performance of the tag antennas was studied with the practical read-range measurements. The study results showed that this absolute algorithm worked reliably and was suitable for RFID applications requiring identification of positions of onsite materials and components. The results also showed that the algorithm achieved a large read range and high accuracy. The study investigates the RFID solutions for Australian LNG (liquefied natural gas industry and was initiated by the collaboration between Woodside Energy, Curtin University, and Industrial Automation Group Pty Ltd.
Feng, Yibo; Li, Xisheng; Zhang, Xiaojuan
2015-05-13
We present an adaptive algorithm for a system integrated with micro-electro-mechanical systems (MEMS) gyroscopes and a compass to eliminate the influence from the environment, compensate the temperature drift precisely, and improve the accuracy of the MEMS gyroscope. We use a simplified drift model and changing but appropriate model parameters to implement this algorithm. The model of MEMS gyroscope temperature drift is constructed mostly on the basis of the temperature sensitivity of the gyroscope. As the state variables of a strong tracking Kalman filter (STKF), the parameters of the temperature drift model can be calculated to adapt to the environment under the support of the compass. These parameters change intelligently with the environment to maintain the precision of the MEMS gyroscope in the changing temperature. The heading error is less than 0.6° in the static temperature experiment, and also is kept in the range from 5° to -2° in the dynamic outdoor experiment. This demonstrates that the proposed algorithm exhibits strong adaptability to a changing temperature, and performs significantly better than KF and MLR to compensate the temperature drift of a gyroscope and eliminate the influence of temperature variation.
A Rule-based Track Anomaly Detection Algorithm for Maritime Force Protection
2014-08-01
likely to perform better with AIS data than with primary radar data. Rule-based algorithms are transparent , easy to use, and use less computation...8039. 6. Kadar I., “ Perceptual Reasoning Managed Situation Assessment for harbour protection”, Springer Science 2009. 7. Jasenvicius R
ITAC volume assessment through a Gaussian hidden Markov random field model-based algorithm.
Passera, Katia M; Potepan, Paolo; Brambilla, Luca; Mainardi, Luca T
2008-01-01
In this paper, a semi-automatic segmentation method for volume assessment of Intestinal-type adenocarcinoma (ITAC) is presented and validated. The method is based on a Gaussian hidden Markov random field (GHMRF) model that represents an advanced version of a finite Gaussian mixture (FGM) model as it encodes spatial information through the mutual influences of neighboring sites. To fit the GHMRF model an expectation maximization (EM) algorithm is used. We applied the method to a magnetic resonance data sets (each of them composed by T1-weighted, Contrast Enhanced T1-weighted and T2-weighted images) for a total of 49 tumor-contained slices. We tested GHMRF performances with respect to FGM by both a numerical and a clinical evaluation. Results show that the proposed method has a higher accuracy in quantifying lesion area than FGM and it can be applied in the evaluation of tumor response to therapy.
AN UNSTRUCTURED FINITE-VOLUME ALGORITHM FOR NONLINEAR TWO-DIMENSIOAL SHALLOW WATER EQUATION
Institute of Scientific and Technical Information of China (English)
WANG Zhi-li; GENG Yan-fen; JIN Sheng
2005-01-01
An unstructured finite-volume numerical algorithm was presented for solution of the two-dimensional shallow water equations, based on triangular or arbitrary quadrilateral meshes. The Roe type approximate Riemann solver was used to the system. A second-order TVD scheme with the van Leer limiter was used in the space discretization and a two-step Runge-Kutta approach was used in the time discretization. An upwind, as opposed to a pointwise, treatment of the slope source terms was adopted and the semi-implicit treatment was used for the friction source terms. Verification for two-dimension dam-break problems are carried out by comparing the present results with others and very good agreement is shown.
Merk, D.; Zinner, T.
2013-08-01
In this paper a new detection scheme for convective initiation (CI) under day and night conditions is presented. The new algorithm combines the strengths of two existing methods for detecting CI with geostationary satellite data. It uses the channels of the Spinning Enhanced Visible and Infrared Imager (SEVIRI) onboard Meteosat Second Generation (MSG). For the new algorithm five infrared (IR) criteria from the Satellite Convection Analysis and Tracking algorithm (SATCAST) and one high-resolution visible channel (HRV) criteria from Cb-TRAM were adapted. This set of criteria aims to identify the typical development of quickly developing convective cells in an early stage. The different criteria include time trends of the 10.8 IR channel, and IR channel differences, as well as their time trends. To provide the trend fields an optical-flow-based method is used: the pyramidal matching algorithm, which is part of Cb-TRAM. The new detection scheme is implemented in Cb-TRAM, and is verified for seven days which comprise different weather situations in central Europe. Contrasted with the original early-stage detection scheme of Cb-TRAM, skill scores are provided. From the comparison against detections of later thunderstorm stages, which are also provided by Cb-TRAM, a decrease in false prior warnings (false alarm ratio) from 91 to 81% is presented, an increase of the critical success index from 7.4 to 12.7%, and a decrease of the BIAS from 320 to 146% for normal scan mode. Similar trends are found for rapid scan mode. Most obvious is the decline of false alarms found for the synoptic class "cold air" masses.
Obuchowski, Nancy A; Barnhart, Huiman X; Buckler, Andrew J; Pennello, Gene; Wang, Xiao-Feng; Kalpathy-Cramer, Jayashree; Kim, Hyun J Grace; Reeves, Anthony P
2015-02-01
Quantitative imaging biomarkers are being used increasingly in medicine to diagnose and monitor patients' disease. The computer algorithms that measure quantitative imaging biomarkers have different technical performance characteristics. In this paper we illustrate the appropriate statistical methods for assessing and comparing the bias, precision, and agreement of computer algorithms. We use data from three studies of pulmonary nodules. The first study is a small phantom study used to illustrate metrics for assessing repeatability. The second study is a large phantom study allowing assessment of four algorithms' bias and reproducibility for measuring tumor volume and the change in tumor volume. The third study is a small clinical study of patients whose tumors were measured on two occasions. This study allows a direct assessment of six algorithms' performance for measuring tumor change. With these three examples we compare and contrast study designs and performance metrics, and we illustrate the advantages and limitations of various common statistical methods for quantitative imaging biomarker studies.
Leeb, Michael
The COMPASS experiment at CERN uses silicon microstrip detectors for beam defini- tion and during hadron program also for the reconstruction of the primary interaction point. In the year 2009 these detectors were operated continuously at cryogenic temper- atures of 200 K for the first time. The objec- tive of this thesis is the optimization of the data reconstruction algorithms used for the silicon microstrip detectors. The clustering algorithm is extended to increase the capa- bility of resolving several particles in close proximity with respect to each other. Fur- thermore improvements on the simulation of the detector response are presented. In addition, the requirements on the detector alignment in order to make full use of the detector capability are studied. Based on a precise alignment, results on the perfor- mance during cryogenic operation are given and compared to the non-cryogenic detector characteristics.
Wireless sensor networks for heritage object deformation detection and tracking algorithm.
Xie, Zhijun; Huang, Guangyan; Zarei, Roozbeh; He, Jing; Zhang, Yanchun; Ye, Hongwu
2014-10-31
Deformation is the direct cause of heritage object collapse. It is significant to monitor and signal the early warnings of the deformation of heritage objects. However, traditional heritage object monitoring methods only roughly monitor a simple-shaped heritage object as a whole, but cannot monitor complicated heritage objects, which may have a large number of surfaces inside and outside. Wireless sensor networks, comprising many small-sized, low-cost, low-power intelligent sensor nodes, are more useful to detect the deformation of every small part of the heritage objects. Wireless sensor networks need an effective mechanism to reduce both the communication costs and energy consumption in order to monitor the heritage objects in real time. In this paper, we provide an effective heritage object deformation detection and tracking method using wireless sensor networks (EffeHDDT). In EffeHDDT, we discover a connected core set of sensor nodes to reduce the communication cost for transmitting and collecting the data of the sensor networks. Particularly, we propose a heritage object boundary detecting and tracking mechanism. Both theoretical analysis and experimental results demonstrate that our EffeHDDT method outperforms the existing methods in terms of network traffic and the precision of the deformation detection.
Welch, Bryan W.; Schrage, Dean S.; Piasecki, Marie T.
2015-01-01
The Space Communications and Navigation (SCaN) Testbed project completed installation and checkout testing of a new S-Band ground station at the NASA Glenn Research Center in Cleveland, Ohio in 2015. As with all ground stations, a key alignment process must be conducted to obtain offset angles in azimuth (AZ) and elevation (EL). In telescopes with AZ-EL gimbals, this is normally done with a two-star alignment process, where telescope-based pointing vectors are derived from catalogued locations with the AZ-EL bias angles derived from the pointing vector difference. For an antenna, the process is complicated without an optical asset. For the present study, the solution was to utilize the gimbal control algorithms closed-loop tracking capability to acquire the peak received power signal automatically from two distinct NASA Tracking and Data Relay Satellite (TDRS) spacecraft, without a human making the pointing adjustments. Briefly, the TDRS satellite acts as a simulated optical source and the alignment process proceeds exactly the same way as a one-star alignment. The data reduction process, which will be discussed in the paper, results in two bias angles which are retained for future pointing determination. Finally, the paper compares the test results and provides lessons learned from the activity.
Real-time tracking data drive process improvements, even while ED volumes continue to climb.
2012-06-01
Christiana Hospital in Newark, DE, has been able to dramatically reduce length-of-stay in the ED by making use of data derived from a real-time location system (RTLS) that tracks the movements of patients, providers, and staff. Administrators say that while some efficiencies are gained from the system alone, most of the positive impact is derived from using the RTLS data to focus on specific processes and make refinements. Within one year of implementing the RTLS technology, LOS in the ED was reduced by 40 minutes for admitted patients and 18 to 20 minutes for the treated-and-released population. A work group focused on process improvements in the ED's fast track section reduced the average LOS from 2.5 hours to 60 minutes or less. Similarly, a work group focused on the ESI 3 population reduced the average treatment time for this population from 5 or 6 hours to 3.4 hours. Administrators say key steps toward a successful RTLS implementation are careful planning for how you want to use the technology, and alleviating staff concerns about why their movements are being tracked.
Gaudin, Damien; Monica, Moroni; Jacopo, Taddeucci; Luca, Shindler; Piergiorgio, Scarlato
2013-04-01
Strombolian eruptions are characterized by mild, frequent explosions that eject gas and ash- to bomb-sized pyroclasts into the atmosphere. Studying these explosions is crucial, both for direct hazard assessment and for understanding eruption dynamics. Conventional thermal and optical imaging already allows characterizing several eruptive processes, but the quantification of key parameters linked to magma properties and conduit processes requires acquiring images at higher frequency. For example, high speed imaging already demonstrated how the size and the pressure of the gas bubble are linked to the decay of the ejection velocity of the particles, and the origin of the bombs, either fresh or recycled material, could be linked to their thermal evolution. However, the manual processing of the images is time consuming. Consequently, it does not allows neither the routine monitoring nor averaged statistics, since only a few relevant particles - usually the fastest - of a few explosions can be taken into account. In order to understand the dynamics of strombolian eruption, and particularly their cyclic behavior, the quantification of the total mass, heat and energy discharge are a crucial point. In this study, we use a Particle Tracking Velocimetry (PTV) algorithm jointly to traditional images processing to automatically extract the above parameters from visible and thermal high-speed videos of individual Strombolian explosions. PTV is an analysis technique where each single particle is detected and tracked during a series of images. Velocity, acceleration, and temperature can then be deduced and time averaged to get an extensive overview of each explosion. The suitability of PTV and its potential limitations in term of detection and representativity is investigated in various explosions of Stromboli (Italy), Yasur (Vanuatu) and Fuego (Guatemala) volcanoes. On most event, multiple sub-explosion are visible. In each sub-explosion, trends are noticeable : (1) the ejection
Tracking Infection Diffusion in Social Networks: Filtering Algorithms and Threshold Bounds
Krishnamurthy, Vikram; Pedersen, Tavis
2016-01-01
This paper deals with the statistical signal pro- cessing over graphs for tracking infection diffusion in social networks. Infection (or Information) diffusion is modeled using the Susceptible-Infected-Susceptible (SIS) model. Mean field approximation is employed to approximate the discrete valued infected degree distribution evolution by a deterministic ordinary differential equation for obtaining a generative model for the infection diffusion. The infected degree distribution is shown to follow polynomial dynamics and is estimated using an exact non- linear Bayesian filter. We compute posterior Cramer-Rao bounds to obtain the fundamental limits of the filter which depend on the structure of the network. Considering the time-varying nature of the real world networks, the relationship between the diffusion thresholds and the degree distribution is investigated using generative models for real world networks. In addition, we validate the efficacy of our method with the diffusion data from a real-world online s...
Analytic Solution for Estimating the Tracking Capability of the RLS Algorithm for Smart Antenna
Institute of Scientific and Technical Information of China (English)
GU Qijun; JIAO Bingli
2001-01-01
Although smart antenna will be intro-duced in the third generation mobile communicationfor its great improvements on the capacity, it is not asimple task to commercialize this technique to prac-tical fields, mainly because the overall procedure re-quires an enormous amount of computation. For mostadaptive processors, the calculation burden can be at-tributed to the calculation complexity required by thealgorithm at each iteration and the iteration rate re-quired by adaptivity of system in time-varying chan-nels. The presented paper presents an analytic solu-tion for estimating the tracking capability of the Re-cursive Least Square (RLS). This approach is formedby the simulation results.
2013-01-01
output. This function is referred to as PRM (for "Peak Rolling Mean") in the following table. By combining these track separation measures with the...9.39 5 1055 Mean-60k 60 km 403 10.28 5 858 Mean-70k 70 km 369 11.62 6 712 Mean-80k Simple Mean n/a 80 km 350 12.54 6 611 PRM :50-30k 30 km 427...7.49 4 1801 PRM :50-40k 40 km 375 6.79 4 2454 PRM :50-50k 50 km 405 7.06 4 2139 PRM :50-60k 60 km 412 7.46 4 1928 PRM :50-70k 70 km 427 7.76 4 1685
Digital Demodulation Algorithm for Multi-Tone FM Signal in New Type Track Circuit
Institute of Scientific and Technical Information of China (English)
ZHU Lin-xiao; WU Si-liang
2006-01-01
The multi-tone frequency modulation (FM) signal transferred through track circuit in automatic train control (ATC) system is analyzed. A digital filter with ideal sloping shape in frequency domain is designed for frequency discrimination. With this filter, the FM signal is converted into AM-FM signal by frequency-to-amplitude conversion. The modulating signal is finally extracted from the envelope of the AM-FM signal. Simulations show that the digital demodulation method could accurately recover the modulating signal in low signal noise ratio (SNR) circumstance, and has good performance in suppressing interference of harmonics of traction current frequency. The feasibility of the proposed method is proved in a hardware system based on SHARC DSP.
Lin, Xiangguo; Liu, Zhengjun; Zhang, Jixian; Shen, Jing
2009-01-01
In light of the increasing availability of commercial high-resolution imaging sensors, automatic interpretation tools are needed to extract road features. Currently, many approaches for road extraction are available, but it is acknowledged that there is no single method that would be successful in extracting all types of roads from any remotely sensed imagery. In this paper, a novel classification of roads is proposed, based on both the roads' geometrical, radiometric properties and the characteristics of the sensors. Subsequently, a general road tracking framework is proposed, and one or more suitable road trackers are designed or combined for each type of roads. Extensive experiments are performed to extract roads from aerial/satellite imagery, and the results show that a combination strategy can automatically extract more than 60% of the total roads from very high resolution imagery such as QuickBird and DMC images, with a time-saving of approximately 20%, and acceptable spatial accuracy. It is proven that a combination of multiple algorithms is more reliable, more efficient and more robust for extracting road networks from multiple-source remotely sensed imagery than the individual algorithms. PMID:22399965
Directory of Open Access Journals (Sweden)
Yifei ZHANG
2017-06-01
Full Text Available The target motion analysis (TMA for a moving scanning emitter with known fixed scan rate by a single observer using the time of interception (TOI measurements only is investigated in this paper. By transforming the TOI of multiple scan cycles into the direction difference of arrival (DDOA model, the observability analysis for the TMA problem is performed. Some necessary conditions for uniquely identifying the scanning emitter trajectory are obtained. This paper also proposes a weighted instrumental variable (WIV estimator for the scanning emitter TMA, which does not require any initial solution guess and is closed-form and computationally attractive. More importantly, simulations show that the proposed algorithm can provide estimation mean square error close to the Cramer-Rao lower bound (CRLB at moderate noise levels with significantly lower estimation bias than the conventional pseudo-linear least square (PLS estimator.
Directory of Open Access Journals (Sweden)
Indrajit Bhattacharya
2011-05-01
Full Text Available The present paper proposes a departmental store automation system based on Radio Frequency Identification (RFID technology and Particle Swarm Optimization (PSO algorithm. The items in the departmental store spanned over different sections and in multiple floors, are tagged with passive RFID tags. The floor is divided into number of zones depending on different types of items that are placed in their respective racks. Each of the zones is placed with one RFID reader, which constantly monitors the items in their zone and periodically sends that information to the application. The problem of systematic periodic monitoring of the store is addressed in this application so that the locations, distributions and demands of every item in the store can be invigilated with intelligence. The proposed application is successfully demonstrated on a simulated case study.
Directory of Open Access Journals (Sweden)
Hongzhe Jin
2017-01-01
Full Text Available This paper presents a synthetic algorithm for tracking a moving object in a multiple-dynamic obstacles environment based on kinematically planar manipulators. By observing the motions of the object and obstacles, Spline filter associated with polynomial fitting is utilized to predict their moving paths for a period of time in the future. Several feasible paths for the manipulator in Cartesian space can be planned according to the predicted moving paths and the defined feasibility criterion. The shortest one among these feasible paths is selected as the optimized path. Then the real-time path along the optimized path is planned for the manipulator to track the moving object in real-time. To improve the convergence rate of tracking, a virtual controller based on PD controller is designed to adaptively adjust the real-time path. In the process of tracking, the null space of inverse kinematic and the local rotation coordinate method (LRCM are utilized for the arms and the end-effector to avoid obstacles, respectively. Finally, the moving object in a multiple-dynamic obstacles environment is thus tracked via real-time updating the joint angles of manipulator according to the iterative method. Simulation results show that the proposed algorithm is feasible to track a moving object in a multiple-dynamic obstacles environment.
Applications of a finite-volume algorithm for incompressible MHD problems
Vantieghem, S.; Sheyko, A.; Jackson, A.
2016-02-01
We present the theory, algorithms and implementation of a parallel finite-volume algorithm for the solution of the incompressible magnetohydrodynamic (MHD) equations using unstructured grids that are applicable for a wide variety of geometries. Our method implements a mixed Adams-Bashforth/Crank-Nicolson scheme for the nonlinear terms in the MHD equations and we prove that it is stable independent of the time step. To ensure that the solenoidal condition is met for the magnetic field, we use a method whereby a pseudo-pressure is introduced into the induction equation; since we are concerned with incompressible flows, the resulting Poisson equation for the pseudo-pressure is solved alongside the equivalent Poisson problem for the velocity field. We validate our code in a variety of geometries including periodic boxes, spheres, spherical shells, spheroids and ellipsoids; for the finite geometries we implement the so-called ferromagnetic or pseudo-vacuum boundary conditions appropriate for a surrounding medium with infinite magnetic permeability. This implies that the magnetic field must be purely perpendicular to the boundary. We present a number of comparisons against previous results and against analytical solutions, which verify the code's accuracy. This documents the code's reliability as a prelude to its use in more difficult problems. We finally present a new simple drifting solution for thermal convection in a spherical shell that successfully sustains a magnetic field of simple geometry. By dint of its rapid stabilization from the given initial conditions, we deem it suitable as a benchmark against which other self-consistent dynamo codes can be tested.
Williams, Steven P.; Parrish, Russell V.
1992-01-01
Three-dimensional pictorial displays incorporating depth cues by means of stereopsis offer a potential means of presenting information in a natural way to enhance situational awareness and improve operator performance. Conventional computational techniques rely on asymptotic projection transformations and symmetric clipping to produce the stereo display. Implementation of two new computational techniques, as asymmetric clipping algorithm and piecewise linear projection transformation, provides the display designer with more control and better utilization of the effective depth-viewing volume to allow full exploitation of stereopsis cuing. Asymmetric clipping increases the perceived field of view (FOV) for the stereopsis region. The total horizontal FOV provided by the asymmetric clipping algorithm is greater throughout the scene viewing envelope than that of the symmetric algorithm. The new piecewise linear projection transformation allows the designer to creatively partition the depth-viewing volume, with freedom to place depth cuing at the various scene distances at which emphasis is desired.
Yu, Ting-To
2013-04-01
It is important to acquire the volume of landslide in short period of time. For hazard mitigation and also emergency response purpose, the traditional method takes much longer time than expected. Due to the weather limit, traffic accessibility and many regulations of law, it take months to handle these process before the actual carry out of filed work. Remote sensing imagery can get the data as long as the visibility allowed, which happened only few day after the event. While traditional photometry requires a stereo pairs images to produce the post event DEM for calculating the change of volume. Usually have to wait weeks or even months for gathering such data, LiDAR or ground GPS measurement might take even longer period of time with much higher cost. In this study we use one post event satellite image and pre-event DTM to compare the similarity between these by alter the DTM with genetic algorithms. The outcome of smartest guess from GAs shall remove or add exact values of height at each location, which been converted into shadow relief viewgraph to compare with satellite image. Once the similarity threshold been make then the guessing work stop. It takes only few hours to finish the entire task, the computed accuracy is around 70% by comparing to the high resolution LiDAR survey at a landslide, southern Taiwan. With extra GCPs, the estimate accuracy can improve to 85% and also within few hours after the receiving of satellite image. Data of this demonstration case is a 5 m DTM at 2005, 2M resolution FormoSat optical image at 2009 and 5M LiDAR at 2010. The GAs and image similarity code is developed on Matlab at windows PC.
Khalil, Hossam; Kim, Dongkyu; Jo, Youngjoon; Park, Kyihwan
2017-06-01
An optical component called a Dove prism is used to rotate the laser beam of a laser-scanning vibrometer (LSV). This is called a derotator and is used for measuring the vibration of rotating objects. The main advantage of a derotator is that it works independently from an LSV. However, this device requires very specific alignment, in which the axis of the Dove prism must coincide with the rotational axis of the object. If the derotator is misaligned with the rotating object, the results of the vibration measurement are imprecise, owing to the alteration of the laser beam on the surface of the rotating object. In this study, a method is proposed for aligning a derotator with a rotating object through an image-processing algorithm that obtains the trajectory of a landmark attached to the object. After the trajectory of the landmark is mathematically modeled, the amount of derotator misalignment with respect to the object is calculated. The accuracy of the proposed method for aligning the derotator with the rotating object is experimentally tested.
Track initial algorithm based on layered clustering method%层次聚类的航迹起始算法
Institute of Scientific and Technical Information of China (English)
卢春燕; 金骁; 邹焕新
2013-01-01
A new track initial algorithm based on layered clustering method is proposed to solve multi-target detection problem with passive reconnaissance data.Especially when the passive reconnaissance scanned aperiodically,the capture plots are fragmentary,and the prior information of targets number and athletic characteristics are insufficient.The algorithm effectively utilized the attributive characteristics to solve the track initial problem.Firstly,the observation set was rough clustered according to the systems of Pulse Frequency (PF),Pulse Recurrence Frequency (PRF),Pulse Width (PW) electromagnetic parameter; Secondly,the exact result of classification was get by clustering of electromagnetic parameter using K-Meaus algorithm; Thirdly,computing the velocity of each dimension of all of the probable point pairs to eliminate the illusive observations by space-time constrained conditions; Ultimately,reset the selected observations according to their capture time,and an extended search approach is utilized to find the final initialed track.Experiments on both simulated and real world data showed its effectiveness and practicability.%针对无源侦察数据不存在周期性扫描、目标定位点迹间的时间间隔随机以及目标数量、运动特性等多项先验信息缺乏状况下的多目标检测问题,提出了层次聚类的航迹起始算法.该算法首先利用信号载频、重频、脉宽参数体制的不同对量测记录集进行粗聚类；其次对雷达工作体制相同的每一个子类,采用K-Means算法对其载频、重频、脉宽三个信号参数进行精聚类；再次对属性聚类后的每一个子类构造所有可能的配对点迹,并计算其分维速度,利用速度法筛选出满足速度约束条件的点迹；最后对筛选出的点迹按接收时间重新排序,利用扩展的搜索算法从第一个时刻开始搜索目标航迹.仿真与真实数据的实验结果验证了本文算法的有效性和实用性.
Benchmarking of state-of-the-art needle detection algorithms in 3D ultrasound data volumes
Pourtaherian, Arash; Zinger, Svitlana; de With, Peter H. N.; Korsten, Hendrikus H. M.; Mihajlovic, Nenad
2015-03-01
Ultrasound-guided needle interventions are widely practiced in medical diagnostics and therapy, i.e. for biopsy guidance, regional anesthesia or for brachytherapy. Needle guidance using 2D ultrasound can be very challenging due to the poor needle visibility and the limited field of view. Since 3D ultrasound transducers are becoming more widely used, needle guidance can be improved and simplified with appropriate computer-aided analyses. In this paper, we compare two state-of-the-art 3D needle detection techniques: a technique based on line filtering from literature and a system employing Gabor transformation. Both algorithms utilize supervised classification to pre-select candidate needle voxels in the volume and then fit a model of the needle on the selected voxels. The major differences between the two approaches are in extracting the feature vectors for classification and selecting the criterion for fitting. We evaluate the performance of the two techniques using manually-annotated ground truth in several ex-vivo situations of different complexities, containing three different needle types with various insertion angles. This extensive evaluation provides better understanding on the limitations and advantages of each technique under different acquisition conditions, which is leading to the development of improved techniques for more reliable and accurate localization. Benchmarking results that the Gabor features are better capable of distinguishing the needle voxels in all datasets. Moreover, it is shown that the complete processing chain of the Gabor-based method outperforms the line filtering in accuracy and stability of the detection results.
Forster, Linda; Seefeldner, Meinhard; Wiegner, Matthias; Mayer, Bernhard
2017-07-01
Halo displays in the sky contain valuable information about ice crystal shape and orientation: e.g., the 22° halo is produced by randomly oriented hexagonal prisms while parhelia (sundogs) indicate oriented plates. HaloCam, a novel sun-tracking camera system for the automated observation of halo displays is presented. An initial visual evaluation of the frequency of halo displays for the ACCEPT (Analysis of the Composition of Clouds with Extended Polarization Techniques) field campaign from October to mid-November 2014 showed that sundogs were observed more often than 22° halos. Thus, the majority of halo displays was produced by oriented ice crystals. During the campaign about 27 % of the cirrus clouds produced 22° halos, sundogs or upper tangent arcs. To evaluate the HaloCam observations collected from regular measurements in Munich between January 2014 and June 2016, an automated detection algorithm for 22° halos was developed, which can be extended to other halo types as well. This algorithm detected 22° halos about 2 % of the time for this dataset. The frequency of cirrus clouds during this time period was estimated by co-located ceilometer measurements using temperature thresholds of the cloud base. About 25 % of the detected cirrus clouds occurred together with a 22° halo, which implies that these clouds contained a certain fraction of smooth, hexagonal ice crystals. HaloCam observations complemented by radiative transfer simulations and measurements of aerosol and cirrus cloud optical thickness (AOT and COT) provide a possibility to retrieve more detailed information about ice crystal roughness. This paper demonstrates the feasibility of a completely automated method to collect and evaluate a long-term database of halo observations and shows the potential to characterize ice crystal properties.
Directory of Open Access Journals (Sweden)
L. Forster
2017-07-01
Full Text Available Halo displays in the sky contain valuable information about ice crystal shape and orientation: e.g., the 22° halo is produced by randomly oriented hexagonal prisms while parhelia (sundogs indicate oriented plates. HaloCam, a novel sun-tracking camera system for the automated observation of halo displays is presented. An initial visual evaluation of the frequency of halo displays for the ACCEPT (Analysis of the Composition of Clouds with Extended Polarization Techniques field campaign from October to mid-November 2014 showed that sundogs were observed more often than 22° halos. Thus, the majority of halo displays was produced by oriented ice crystals. During the campaign about 27 % of the cirrus clouds produced 22° halos, sundogs or upper tangent arcs. To evaluate the HaloCam observations collected from regular measurements in Munich between January 2014 and June 2016, an automated detection algorithm for 22° halos was developed, which can be extended to other halo types as well. This algorithm detected 22° halos about 2 % of the time for this dataset. The frequency of cirrus clouds during this time period was estimated by co-located ceilometer measurements using temperature thresholds of the cloud base. About 25 % of the detected cirrus clouds occurred together with a 22° halo, which implies that these clouds contained a certain fraction of smooth, hexagonal ice crystals. HaloCam observations complemented by radiative transfer simulations and measurements of aerosol and cirrus cloud optical thickness (AOT and COT provide a possibility to retrieve more detailed information about ice crystal roughness. This paper demonstrates the feasibility of a completely automated method to collect and evaluate a long-term database of halo observations and shows the potential to characterize ice crystal properties.
头部多角度人脸快速跟踪算法DSP实现%Fast face tracking algorithm of head multi-position based on DSP
Institute of Scientific and Technical Information of China (English)
姜俊金; 王增才; 朱淑亮
2012-01-01
针对传统驾驶员疲劳检测人脸跟踪算法复杂,DSP实现时实时性不强,不能有效地实现多角度人脸跟踪的问题,提出了一种快速人脸跟踪算法.该算法通过对YCbCr肤色模型进行图像预处理、肤色检测,提取人脸区域,通过对亮度信号Y进行统计运算,判断人脸边界,再进行相似度判断,从而实现人脸区域的跟踪.实验结果表明,该方法简单、鲁棒性强,能够快速地实现彩色图像人脸多角度跟踪.%In the field of real-time human face tracking for driver fatigue detection, the classic algorithms are so complex that the DSP system can not track the face in multi-angle state quickly and exactly, so a new face tracking algorithm is presented. In YCbCr human face color model, the image is preprocessed first, then the face region is extracted through the face color detec-tion. Through calculating the brightness signal Y, the face edge can be detected. Then a symmetry similarity measure is used to check the factuality of the face tracking. In this way, the face region can be tracked Experimental results indicate that this algo-rithm is so simple and can realize the tracking of face in multi-angle of color image.
VISUAL TRACKING ALGORITHM BASED ON RANK SIFT%基于 SIFT 排序的视觉跟踪算法
Institute of Scientific and Technical Information of China (English)
孙超; 许悦雷; 查宇飞; 黄宏图
2015-01-01
Aiming at the impact of unstable key points on visual tracking algorithm which uses SIFT as its target feature,we present the rank SIFT-based visual tracking algorithm.To realise rank SIFT,we propose the spatial stability factor and the temporal stability factor and compose the importance weights with them for representing the significance of each key point.Based on rank SIFT,each key point takes part in tracking according to its own importance weight,so that the rank SIFT-based visual tracking is achieved.The algorithm overcomes the impact of unstable key points on tracking outcomes,therefore improves the accuracy and robustness of tracking.%针对不稳定的关键点对以 SIFT（Scale Invariant Feature Transform）为目标特征的视觉跟踪算法的影响，提出基于 SIFT 排序的视觉跟踪算法。为实现 SIFT 排序，提出空域稳定因子和时域稳定因子，并由此构成重要性权重，以表征各个特征点的重要程度。在 SIFT 排序的基础上，各个关键点按照重要性权重的不同参与跟踪，从而实现基于 SIFT 排序的视觉跟踪。该算法克服了不稳定的关键点对跟踪结果的影响，从而提高跟踪的准确性和鲁棒性。
基于粒子滤波的声源方位跟踪算法%SOUND SOURCE ORIENTATION TRACKING ALGORITHM BASED ON PARTICLE FILTERING
Institute of Scientific and Technical Information of China (English)
殷侠; 蔡卫平; 徐健; 陆泽橼
2012-01-01
Aiming at speaker' s orientation tracking issue in reverberant environment, a sound source orientation tracking algorithm based on particle filtering is presented in this paper. According to the moving characteristic of the speaker, the algorithm sets up based on the Lan-gevin equations a dynamic model of sound source orientation, the steered response power with phase transform weight (SRP-PHAT) is used as the localisation function, and the particle filtering is employed to track the sound source orientation. The real acoustic data recorded in a typical meeting room using a small-scale microphone array is used for tracking experiments. Results show that the proposed algorithm can realise effectively the orientation tracking of the randomly walking speaker, in which, the root mean square error of tracking in direction of the horizontal angle and the elevation are all less than 5°.%针对混响环境中说话人方位跟踪问题,提出一种基于粒子滤波的声源方位跟踪算法.该算法根据说话人的运动特点,在Langevin方程的基础上构建声源方位的动态模型,采用相位变换加权的可控响应功率作为定位函数,运用粒子滤波对声源方位进行跟踪.使用典型会议室环境下小型麦克风阵列接收的真实数据来做实验.结果表明,该算法能有效地实现随机走动说话人的方位跟踪,并且在水平角和仰角方向的均方根误差均小于5..
Directory of Open Access Journals (Sweden)
Calebe A. Matias
2017-07-01
Full Text Available The purpose of the present study is to simulate and analyze an isolated full-bridge DC/DC boost converter, for photovoltaic panels, running a modified perturb and observe maximum power point tracking method. The zero voltage switching technique was used in order to minimize the losses of the converter for a wide range of solar operation. The efficiency of the power transfer is higher than 90% for large solar operating points. The panel enhancement due to the maximum power point tracking algorithm is 5.06%.
Kou, Jisheng
2017-09-30
Capillary pressure can significantly affect the phase properties and flow of liquid-gas fluids in porous media, and thus, the phase equilibrium calculation incorporating capillary pressure is crucial to simulate such problems accurately. Recently, the phase equilibrium calculation at specified moles, volume and temperature (NVT-flash) becomes an attractive issue. In this paper, capillarity is incorporated into the phase equilibrium calculation at specified moles, volume and temperature. A dynamical model for such problem is developed for the first time by using the laws of thermodynamics and Onsager\\'s reciprocal principle. This model consists of the evolutionary equations for moles and volume, and it can characterize the evolutionary process from a non-equilibrium state to an equilibrium state in the presence of capillarity effect at specified moles, volume and temperature. The phase equilibrium equations are naturally derived. To simulate the proposed dynamical model efficiently, we adopt the convex-concave splitting of the total Helmholtz energy, and propose a thermodynamically stable numerical algorithm, which is proved to preserve the second law of thermodynamics at the discrete level. Using the thermodynamical relations, we derive a phase stability condition with capillarity effect at specified moles, volume and temperature. Moreover, we propose a stable numerical algorithm for the phase stability testing, which can provide the feasible initial conditions. The performance of the proposed methods in predicting phase properties under capillarity effect is demonstrated on various cases of pure substance and mixture systems.
Energy Technology Data Exchange (ETDEWEB)
Laubender, Ruediger P. [German Cancer Consortium (DKTK), Heidelberg (Germany); University Hospital Munich - Campus Grosshadern, Institute of Medical Informatics, Biometry, and Epidemiology (IBE), Munich (Germany); German Cancer Research Center (DKFZ), Heidelberg (Germany); Lynghjem, Julia; D' Anastasi, Melvin; Graser, Anno [University Hospital Munich - Campus Grosshadern, Institute for Clinical Radiology, Munich (Germany); Heinemann, Volker; Modest, Dominik P. [University Hospital Munich - Campus Grosshadern, Department of Medical Oncology, Munich (Germany); Mansmann, Ulrich R. [University Hospital Munich - Campus Grosshadern, Institute of Medical Informatics, Biometry, and Epidemiology (IBE), Munich (Germany); Sartorius, Ute; Schlichting, Michael [Merck KGaA, Darmstadt (Germany)
2014-07-15
To evaluate the agreement between tumour volume derived from semiautomated volumetry (SaV) and tumor volume defined by spherical volume using longest lesion diameter (LD) according to Response Evaluation Criteria In Solid Tumors (RECIST) or ellipsoid volume using LD and longest orthogonal diameter (LOD) according to World Health Organization (WHO) criteria. Twenty patients with metastatic colorectal cancer from the CIOX trial were included. A total of 151 target lesions were defined by baseline computed tomography and followed until disease progression. All assessments were performed by a single reader. A variance component model was used to compare the three volume versions. There was a significant difference between the SaV and RECIST-based tumour volumes. The same model showed no significant difference between the SaV and WHO-based volumes. Scatter plots showed that the RECIST-based volumes overestimate lesion volume. The agreement between the SaV and WHO-based relative changes in tumour volume, evaluated by intraclass correlation, showed nearly perfect agreement. Estimating the volume of metastatic lesions using both the LD and LOD (WHO) is more accurate than those based on LD only (RECIST), which overestimates lesion volume. The good agreement between the SaV and WHO-based relative changes in tumour volume enables a reasonable approximation of three-dimensional tumour burden. (orig.)
视频序列中面向行人的多目标跟踪算法%Pedestrian Oriented Multi-Object Tracking Algorithm in Video Sequence
Institute of Scientific and Technical Information of China (English)
李琦; 邵春福; 岳昊
2013-01-01
To track pedestrian oriented multiple objects in video sequence, this paper presents a tracking algorithm using multi-cue integration approach and high degree occlusion processing. Combined with the mean-shift algorithm, multi-cue integration method could track object in normal condition by fusing the color and motion information. To deal with the issue of occlusion involving multiple objects, the area change of the object during occlusion has been analyzed in theory. An occlusion factor is advanced to detect occlusion occur, identify obstructer or occluded object and to check the reappearance of an occluded object. Experiment results show that the proposed tracking algorithm could correctly find out and resolve the occlusion among the multiple objects so that it could successfully track the multiple pedestrians.%为实现视频序列中多行人目标跟踪,基于多信息融合方法,考虑多目标间严重遮挡,建立面向行人的多目标跟踪算法.提出多信息融合算法融合目标颜色和运动信息,结合均值漂移算法思想,实现常态下目标跟踪.针对多行人目标参与的遮挡,通过理论分析遮挡过程中目标面积变化,提出遮挡因子判别遮挡发生、辨识遮挡者和被遮挡对象、确认被遮挡对象重新出现等.实验结果表明,该方法能够正确跟踪行人目标,判断并处理多目标间的严重遮挡.
Directory of Open Access Journals (Sweden)
Zvonko Radosavljević
2005-05-01
Full Text Available U radu je analizirana primena IMM algoritma sa tri modela Kalmanovih filtara, za praćenje cilja pomoću osmatračkog radara. Prvi Kalmanov filtar podešen je da prati ciljeve koji se kreću po pravolinijskoj trajektoriji bez ubrzanja, drugi prati ciljeve koji se kreću ubrzano i vrše blag manevar, a treći je namenjen za praćenje ciljeva koji se kreću ubrzano i vrše oštar manevar. Dat je opis algoritma kao i vrednosti odgovarajućih parametara i matrica prelaza za Kalmanove filtre, kao i uporedna analiza algoritma u odnosu na standardan Kalmanov filtar šestog reda. Prikazani rezultati srednje kvadratne greške praćenja po x i у koordinati pokazuju opravdanost izbora predložene metode praćenja. / This paper considers comparative analysis the problem of maneuvering target tracking to IMM algorithm with 3 standard Kalman filters and same standard Kalman filter 6. order, using data from TWS radar. The first Kalman filter from IMM algorithms is tuned for tracking of target moving along the rectilinear trajectory -without acceleration, the second tracks the targets with acceleration and gentle maneuver, and the third Kalman filter tracks the target with acceleration and sharp maneuver. The mathematical model of algorithm and values of appropriate parameters and Kalman filter matrices, are presented. The results of RMSE of tracking in x and у coordinates, show the validity of the proposed method.
基于卡尔曼滤波的运动人体跟踪算法研究%Research on Moving Human Tracking Algorithm Based on Kalman Filter
Institute of Scientific and Technical Information of China (English)
乔坤; 郭朝勇; 史进伟
2012-01-01
提出一种基于卡尔曼滤波的运动目标快速跟踪算法.利用卡尔曼滤波器的预测功能,预测运动人体目标在下一帧中的位置,在Matlab仿真环境下实现该跟踪算法,实验结果表明:该算法对人体目标的运动趋势能够做出正确的预测估计,跟踪效果和性能较为稳定和可靠.此外,该算法将图像全局搜索问题转换为局部搜索,使运算量减少,满足实时性跟踪要求,实现了对运动目标的快速跟踪.%A real-time moving object tracking algorithm based on Kalman filter is proposed The possible position of the moving human in the next frame is predicted by Kalman filter's predictive function. Based on the Matlab simulation environment to achieve the tracking algorithm and the experimental results show that the algorithm can correctly estimate the human's motion trend and the tracking results and performance is better. In addition, the global searching scope of an image is converted to local scope, thus reduce the computation and meet the requirements of real-time tracking, and the speedy tracking of moving human is realized.
一种改进的多关节目标跟踪算法%Improved multi-articulated object tracking algorithm
Institute of Scientific and Technical Information of China (English)
李伟群
2011-01-01
In order to improve the tracking efficiency and precise of multi-articulated object tracking, this paper proposed an algorithm of object tracking.Firstly constructed a graphical model that employed clique potentials which to denote multi-articulated object, since it made use of clique potential function etc.To reduce the complexity of graphical model such as traditional graphical model, and it also combined some information such as depth, edges, colors.Then it ultilized the K-means, Mean-shift algorithm and particle filtering to track mobile.Experiment results show that the proposed algorithm maintains the high precision and the ability to control the occlusion ,and it can meet requirements of mutil-articulated object tracking.%为提高多关节物体的跟踪效率和精确度,提出了一种目标跟踪算法.首先建立多关节物体的团结构模型,模型的建立结合团势函数等有效降低了传统图模型的冗余度,并结合目标物理的深度、边缘、颜色等信息,利用K-means、Mean-shift算法、粒子滤波实现目标跟踪.实验结果表明,该推理算法能够提高跟踪效率,有较强的鲁棒性,能够满足多关节目标的跟踪要求.
Energy Technology Data Exchange (ETDEWEB)
Feng, Y; Olsen, J.; Parikh, P.; Noel, C; Wooten, H; Du, D; Mutic, S; Hu, Y [Washington University, St. Louis, MO (United States); Kawrakow, I; Dempsey, J [Washington University, St. Louis, MO (United States); ViewRay Co., Oakwood Village, OH (United States)
2014-06-01
Purpose: Evaluate commonly used segmentation algorithms on a commercially available real-time MR image guided radiotherapy (MR-IGRT) system (ViewRay), compare the strengths and weaknesses of each method, with the purpose of improving motion tracking for more accurate radiotherapy. Methods: MR motion images of bladder, kidney, duodenum, and liver tumor were acquired for three patients using a commercial on-board MR imaging system and an imaging protocol used during MR-IGRT. A series of 40 frames were selected for each case to cover at least 3 respiratory cycles. Thresholding, Canny edge detection, fuzzy k-means (FKM), k-harmonic means (KHM), and reaction-diffusion level set evolution (RD-LSE), along with the ViewRay treatment planning and delivery system (TPDS) were included in the comparisons. To evaluate the segmentation results, an expert manual contouring of the organs or tumor from a physician was used as a ground-truth. Metrics value of sensitivity, specificity, Jaccard similarity, and Dice coefficient were computed for comparison. Results: In the segmentation of single image frame, all methods successfully segmented the bladder and kidney, but only FKM, KHM and TPDS were able to segment the liver tumor and the duodenum. For segmenting motion image series, the TPDS method had the highest sensitivity, Jarccard, and Dice coefficients in segmenting bladder and kidney, while FKM and KHM had a slightly higher specificity. A similar pattern was observed when segmenting the liver tumor and the duodenum. The Canny method is not suitable for consistently segmenting motion frames in an automated process, while thresholding and RD-LSE cannot consistently segment a liver tumor and the duodenum. Conclusion: The study compared six different segmentation methods and showed the effectiveness of the ViewRay TPDS algorithm in segmenting motion images during MR-IGRT. Future studies include a selection of conformal segmentation methods based on image/organ-specific information
REAL-TIME FACE TRACKING ALGORITHM BASED ON ONLINE INCREMENTAL LEARNING%基于在线增量学习的实时人脸跟踪算法
Institute of Scientific and Technical Information of China (English)
包芳; 张炎凯; 王士同
2016-01-01
提出基于在线增量式极端随机森林分类器的实时人脸跟踪算法。算法用在线极端随机森林分类器实现基于检测的跟踪，并结合动态目标框架和 P-N 学习矫正检测的错误。实验结果表明，该算法能够在不确定背景下对任意人脸实现较长时间段内的稳定快速的实时跟踪，并能有效排除背景等的干扰，效果较好。%The paper proposes a real-time face tracking algorithm,which is based on online incremental extremely random forests classifier.The algorithm achieves detection-based real-time tracking using online incremental extremely random forests classifier,and combines dynamic target framework and P-N learning to correct detection errors.Experimental results show,the proposed algorithm can realise fast and stable real-time tracking for any face in a longer period under uncertain background,and can effectively overcome interferences such as background with preferable effect.
Withofs, Nadia; Bernard, Claire; Van der Rest, Catherine; Martinive, Philippe; Hatt, Mathieu; Jodogne, Sebastien; Visvikis, Dimitris; Lee, John A; Coucke, Philippe A; Hustinx, Roland
2014-09-08
PET/CT imaging could improve delineation of rectal carcinoma gross tumor volume (GTV) and reduce interobserver variability. The objective of this work was to compare various functional volume delineation algorithms. We enrolled 31 consecutive patients with locally advanced rectal carcinoma. The FDG PET/CT and the high dose CT (CTRT) were performed in the radiation treatment position. For each patient, the anatomical GTVRT was delineated based on the CTRT and compared to six different functional/metabolic GTVPET derived from two automatic segmentation approaches (FLAB and a gradient-based method); a relative threshold (45% of the SUVmax) and an absolute threshold (SUV > 2.5), using two different commercially available software (Philips EBW4 and Segami OASIS). The spatial sizes and shapes of all volumes were compared using the conformity index (CI). All the delineated metabolic tumor volumes (MTVs) were significantly different. The MTVs were as follows (mean ± SD): GTVRT (40.6 ± 31.28ml); FLAB (21.36± 16.34 ml); the gradient-based method (18.97± 16.83ml); OASIS 45% (15.89 ± 12.68 ml); Philips 45% (14.52 ± 10.91 ml); OASIS 2.5 (41.6 2 ± 33.26 ml); Philips 2.5 (40 ± 31.27 ml). CI between these various volumes ranged from 0.40 to 0.90. The mean CI between the different MTVs and the GTVCT was algorithms and the software products. The manipulation of PET/CT images and MTVs, such as the DICOM transfer to the Radiation Oncology Department, induced additional volume variations.
Institute of Scientific and Technical Information of China (English)
谢红; 原博; 解武
2016-01-01
At present, Camshift is widely used in the field of moving object tracking. Aiming at the problem that the target may lose in tracking, this paper proposes an improved Camshift algorithm based on feature point matching al⁃gorithm of ORB ( oriented brief) . In the Camshift algorithm, a back⁃projection image is obtained from the color his⁃togram model of each image frame, the size of searching window is adjusted adaptively according to the object size, and the center position of window is computed iteratively, so as to extend the searching window's size adaptively. However, this algorithm lacks of the mechanisms to regain the missed target when the phenomenon that the tracking object is missing occurs. This problem is solved by introducing the ORB algorithm to match the moving target. The experimental results show that, the tracking performance of the improved algorithm is better than the original one. The improved algorithm can achieve the sustained tracking.%在运动目标跟踪方面，当前比较常用的算法就是Camshift算法。针对该算法容易产生目标丢失的情况，在本文中提出一种基于ORB（ oriented brief）特征点匹配的Camshift改进算法。原Camshift算法可以从目标的颜色直方图模型得到每帧图像的反向投影图，根据目标的大小自适应地调整搜索窗口尺寸，并迭代计算各目标窗口的质心位置，从而自适应地扩展搜索窗口。但是当发生目标丢失的情况时，缺少重新寻找得到目标的机制。本文通过引入ORB算法对运动目标进行匹配从而解决了这个问题。仿真实验结果表明，改进算法相对原算法具有良好的跟踪效果，可以实现持续跟踪。
Wang, Zu-liang; Zhang, Ting; Xie, Shi-yang
2017-01-01
In order to improve the agricultural tracing efficiency and reduce tracking and monitoring cost, agricultural products quality tracking and tracing based on Radio-Frequency Identification(RFID) technology is studied, then tracing and tracking model is set up. Three-layer structure model is established to realize the high quality of agricultural products traceability and tracking. To solve the collision problems between multiple RFID tags and improve the identification efficiency a new reservation slot allocation mechanism is proposed. And then we analyze and optimize the parameter by numerical simulation method.
Befort, Daniel J.; Kruschke, Tim; Leckebusch, Gregor C.
2017-04-01
Tropical Cyclones over East Asia have huge socio-economic impacts due to their strong wind fields and large rainfall amounts. Especially, the most severe events are associated with huge economic losses, e.g. Typhoon Herb in 1996 is related to overall losses exceeding 5 billion US (Munich Re, 2016). In this study, an objective tracking algorithm is applied to JRA55 reanalysis data from 1979 to 2014 over the Western North Pacific. For this purpose, a purely wind based algorithm, formerly used to identify extra-tropical wind storms, has been further developed. The algorithm is based on the exceedance of the local 98th percentile to define strong wind fields in gridded climate data. To be detected as a tropical cyclone candidate, the following criteria must be fulfilled: 1) the wind storm must exist for at least eight 6-hourly time steps and 2) the wind field must exceed a minimum size of 130.000km2 for each time step. The usage of wind information is motivated to focus on damage related events, however, a pre-selection based on the affected region is necessary to remove events of extra-tropical nature. Using IBTrACS Best Tracks for validation, it is found that about 62% of all detected tropical cyclone events in JRA55 reanalysis can be matched to an observed best track. As expected the relative amount of matched tracks increases with the wind intensity of the event, with a hit rate of about 98% for Violent Typhoons, above 90% for Very Strong Typhoons and about 75% for Typhoons. Overall these results are encouraging as the parameters used to detect tropical cyclones in JRA55, e.g. minimum area, are also suitable to detect TCs in most CMIP5 simulations and will thus allow estimates of potential future changes.
Troitskaya, Yuliya; Lebedev, Sergey; Soustova, Irina; Rybushkina, Galina; Papko, Vladislav; Baidakov, Georgy; Panyutin, Andrey
One of the recent applications of satellite altimetry originally designed for measurements of the sea level [1] is associated with remote investigation of the water level of inland waters: lakes, rivers, reservoirs [2-7]. The altimetry data re-tracking algorithms developed for open ocean conditions (e.g. Ocean-1,2) [1] often cannot be used in these cases, since the radar return is significantly contaminated by reflection from the land. The problem of minimization of errors in the water level retrieval for inland waters from altimetry measurements can be resolved by re-tracking satellite altimetry data. Recently, special re-tracking algorithms have been actively developed for re-processing altimetry data in the coastal zone when reflection from land strongly affects echo shapes: threshold re-tracking, The other methods of re-tracking (threshold re-tracking, beta-re-tracking, improved threshold re-tracking) were developed in [9-11]. The latest development in this field is PISTACH product [12], in which retracking bases on the classification of typical forms of telemetric waveforms in the coastal zones and inland water bodies. In this paper a novel method of regional adaptive re-tracking based on constructing a theoretical model describing the formation of telemetric waveforms by reflection from the piecewise constant model surface corresponding to the geography of the region is considered. It was proposed in [13, 14], where the algorithm for assessing water level in inland water bodies and in the coastal zone of the ocean with an error of about 10-15 cm was constructed. The algorithm includes four consecutive steps: - constructing a local piecewise model of a reflecting surface in the neighbourhood of the reservoir; - solving a direct problem by calculating the reflected waveforms within the framework of the model; - imposing restrictions and validity criteria for the algorithm based on waveform modelling; - solving the inverse problem by retrieving a tracking point
Maneuvering Target Tracking Algorithm Based on IMM-Singer Model%IMM-Singer模型的机动目标跟踪算法
Institute of Scientific and Technical Information of China (English)
谭顺成; 王国宏; 王娜
2012-01-01
The Interacting Multiple Model (IMM) algorithm is an effective solution to maneuvering target tracking, however, its performance depends on the type, number and parameters of the models. The Singer Model algorithm can be utilized for maneuvering target tracking except that the parameters such as maneuver frequency, process noise and so on are hardly set. To the problems as mentioned above, with the merit that IMM can be combined with other algorithms easily, a novel filter of IMM-Singer Model is proposed such that the parameters of Singer Model can be set automatically. Simulation results show that compared with the single Singer Model and the general IMM, the proposed algorithm is more effective in improving the accuracy of maneuvering target tracking.%交互式多模型(IMM)算法是一种有效机动目标跟踪算法,但其性能与模型的选择、个数以及参数有关.Singer模型算法可以实现对机动目标的跟踪,但该算法存在机动频率和过程噪声大小等参数难以选取的问题.针对以上情况,利用IMM算法易于结合其他算法的特点,提出一种基于IMM-Singer模型的机动目标跟踪算法,实现Singer模型参数的自适应选择.仿真结果表明,该算法比单一的Singer模型算法或一般的IMM算法更能有效提高机动目标跟踪精度.
基于方向直方图的Mean shift目标跟踪新算法%New Mean shift tracking algorithm based on orientation histogram
Institute of Scientific and Technical Information of China (English)
秦臻; 曹剑中
2011-01-01
Mean shift算法是一种非参数密度估计算法,可以实现快速的最优匹配.为了有效地将Mean shift算法应用到灰度图像中,使用空间分布和纹理信息作为匹配信息,提出了一种基于空间方向直方图的Mean shift跟踪新算法.利用卡尔曼滤波器来获得每帧目标的起始位置,再利用Mean shift算法得到跟踪位置.实验结果证明,该算法在目标运动较快,目标尺度变化的情况下仍能稳定、实时、高效地跟踪目标.%The Mean shift algorithm is a nonparametric density estimation method. The fast and optimal mode matching can be achieved by this method. In order to apply Mean shift algorithm on gray-level image effectively, a new tracking algorithm of Mean shift based on orientation histogram is proposed. It uses space spread and vein as matching information. The starting position of target is found with Kalman filter in every frame, and then Mean shift is utilized to track the target position. In the situation of target moving fast and changing of size, experiment results show that the object can be tracked steadily, effectively and real-time by using the proposed algorithm.
Muckenhuber, Stefan; Sandven, Stein
2017-08-01
An open-source sea ice drift algorithm for Sentinel-1 SAR imagery is introduced based on the combination of feature tracking and pattern matching. Feature tracking produces an initial drift estimate and limits the search area for the consecutive pattern matching, which provides small- to medium-scale drift adjustments and normalised cross-correlation values. The algorithm is designed to combine the two approaches in order to benefit from the respective advantages. The considered feature-tracking method allows for an efficient computation of the drift field and the resulting vectors show a high degree of independence in terms of position, length, direction and rotation. The considered pattern-matching method, on the other hand, allows better control over vector positioning and resolution. The preprocessing of the Sentinel-1 data has been adjusted to retrieve a feature distribution that depends less on SAR backscatter peak values. Applying the algorithm with the recommended parameter setting, sea ice drift retrieval with a vector spacing of 4 km on Sentinel-1 images covering 400 km × 400 km, takes about 4 min on a standard 2.7 GHz processor with 8 GB memory. The corresponding recommended patch size for the pattern-matching step that defines the final resolution of each drift vector is 34 × 34 pixels (2.7 × 2.7 km). To assess the potential performance after finding suitable search restrictions, calculated drift results from 246 Sentinel-1 image pairs have been compared to buoy GPS data, collected in 2015 between 15 January and 22 April and covering an area from 80.5 to 83.5° N and 12 to 27° E. We found a logarithmic normal distribution of the displacement difference with a median at 352.9 m using HV polarisation and 535.7 m using HH polarisation. All software requirements necessary for applying the presented sea ice drift algorithm are open-source to ensure free implementation and easy distribution.
The Research on Detection and Tracking Algorithms of Motion Obj ects%运动目标检测与跟踪算法的研究
Institute of Scientific and Technical Information of China (English)
刘晓悦; 孟妍
2015-01-01
The detection and tracking algorithm of motion obj ects is one of hotspots in the field of computer vision.It’s also the key intelligent technology of video surveillance system.It con-cerns the research results of many fields such as image processing,pattern recognition and artificial intelli-gence,and so on.This thesis is mainly done some researches on the detection and tracking algorithm of video motion obj ects.In terms of motion obj ects detection,three common approaches in this field of mo-tion obj ect detecting are analyzed including background subtraction,temporal differencing and optical flow. Then their relative merits and main application range are pointed out.In the motion obj ects tracking as-pects,focuses on introducing the Mean Shift tracking algorithm,which belongs on tracking algorithm based on feature matching.%运动目标检测与跟踪的算法一直以来是计算机视觉领域中的核心课题，也是智能视频监控中的关键技术。它主要是包含了图像处理、模式识别、人工智能等领域内的成果。着重研究运动目标检测与跟踪的算法[13]，并通过编程实现方法的有效性。在运动检测方面，主要应用的算法包括背景差分法、帧间差分法以及光流法，指出了这些算法的优缺点以及适用范围。在运动目标跟踪方面，主要研究了特征匹配跟踪算法中的Mean Shift算法[19]。
Trache, Tudor; Stöbe, Stephan; Tarr, Adrienn; Pfeiffer, Dietrich; Hagendorff, Andreas
2014-12-01
Comparison of 3D and 2D speckle tracking performed on standard 2D and triplane 2D datasets of normal and pathological left ventricular (LV) wall-motion patterns with a focus on the effect that 3D volume rate (3DVR), image quality and tracking artifacts have on the agreement between 2D and 3D speckle tracking. 37 patients with normal LV function and 18 patients with ischaemic wall-motion abnormalities underwent 2D and 3D echocardiography, followed by offline speckle tracking measurements. The values of 3D global, regional and segmental strain were compared with the standard 2D and triplane 2D strain values. Correlation analysis with the LV ejection fraction (LVEF) was also performed. The 3D and 2D global strain values correlated good in both normally and abnormally contracting hearts, though systematic differences between the two methods were observed. Of the 3D strain parameters, the area strain showed the best correlation with the LVEF. The numerical agreement of 3D and 2D analyses varied significantly with the volume rate and image quality of the 3D datasets. The highest correlation between 2D and 3D peak systolic strain values was found between 3D area and standard 2D longitudinal strain. Regional wall-motion abnormalities were similarly detected by 2D and 3D speckle tracking. 2DST of triplane datasets showed similar results to those of conventional 2D datasets. 2D and 3D speckle tracking similarly detect normal and pathological wall-motion patterns. Limited image quality has a significant impact on the agreement between 3D and 2D numerical strain values.
Institute of Scientific and Technical Information of China (English)
GUO Qiang; YANG Xin
2006-01-01
A statistical algorithm for the reconstruction from time sequence echocardiographic images is proposed in this paper.The ability to jointly restore the images and reconstruct the 3D images without blurring the boundary is the main innovation of this algorithm. First, a Bayesian model based on MAP-MRF is used to reconstruct 3D volume, and extended to deal with the images acquired by rotation scanning method. Then, the spatiotemporal nature of ultrasound images is taken into account for the parameter of energy function, which makes this statistical model anisotropic. Hence not only can this method reconstruct 3D ultrasound images, but also remove the speckle noise anisotropically. Finally, we illustrate the experiments of our method on the synthetic and medical images and compare it with the isotropic reconstruction method.
Pedrotti, Marco; Lei, Shengguang; Dzaack, Jeronimo; Rötting, Matthias
2011-06-01
Event detection is the conversion of raw eye-tracking data into events--such as fixations, saccades, glissades, blinks, and so forth--that are relevant for researchers. In eye-tracking studies, event detection algorithms can have a serious impact on higher level analyses, although most studies do not accurately report their settings. We developed a data-driven eyeblink detection algorithm (Identification-Artifact Correction [I-AC]) for 50-Hz eye-tracking protocols. I-AC works by first correcting blink-related artifacts within pupil diameter values and then estimating blink onset and offset. Artifact correction is achieved with data-driven thresholds, and more reliable pupil data are output. Blink parameters are defined according to previous studies on blink-related visual suppression. Blink detection performance was tested with experimental data by visually checking the actual correspondence between I-AC output and participants' eye images, recorded by the eyetracker simultaneously with gaze data. Results showed a 97% correct detection percentage.
Antonello, M
2013-01-01
Liquid Argon Time Projection Chamber (LAr TPC) detectors offer charged particle imaging capability with remarkable spatial resolution. Precise event reconstruction procedures are critical in order to fully exploit the potential of this technology. In this paper we present a new, general approach of three-dimensional reconstruction for the LAr TPC with a practical application to track reconstruction. The efficiency of the method is evaluated on a sample of simulated tracks. We present also the application of the method to the analysis of real data tracks collected during the ICARUS T600 detector operation with the CNGS neutrino beam.
Directory of Open Access Journals (Sweden)
M. Antonello
2013-01-01
Full Text Available Liquid Argon Time Projection Chamber (LAr TPC detectors offer charged particle imaging capability with remarkable spatial resolution. Precise event reconstruction procedures are critical in order to fully exploit the potential of this technology. In this paper we present a new, general approach to 3D reconstruction for the LAr TPC with a practical application to the track reconstruction. The efficiency of the method is evaluated on a sample of simulated tracks. We present also the application of the method to the analysis of stopping particle tracks collected during the ICARUS T600 detector operation with the CNGS neutrino beam.
Enhanced animation of parallel algorithms. Volume 1. Master's thesis
Energy Technology Data Exchange (ETDEWEB)
Lack, M.D.
1991-12-01
Algorithm animation is a visualization method used to enhance understanding of the functioning of an algorithm or program. Visualization is used for many purposes, including education, algorithm research, performance analysis, and program debugging. This research, which follows from previous work, examines algorithm animation requirements for the various visualization purposes and extends the capabilities of an existing facility, the AFIT Algorithm Animation Research Facility (AAARF). The structure of AAARF is summarised and its visualization capabilities presented, analysed and compared with other similar packages. This research focuses on the parallel data requirements of the AAARF users, and the meaningful display of large amounts of data. This paper discusses a series of refined animations suitable for a variety of purposes which are capable of conveying detailed information in a concise and timely manner and the development and implementation of a new performance animation type is presented. These animations are built upon pedagogical efforts in a classroom environment. To assist novice users in efficiently using AAARF, an expert system interface has been implemented to advise on optimizing environment configuration. Considerable effort has been devoted to porting AAARF to the X Windows environment and the lessons learned and progress made are discussed.
Algorithm of reentry ballistic target tracking based on multiple model%基于多模型的再入弹道目标跟踪算法
Institute of Scientific and Technical Information of China (English)
钮俊清; 任清安; 刘军伟
2015-01-01
In the anti-missile defense system, the tracking and identification of reentry ballistic target are the critical problems. However, the traditional method could not applied to the tracking for different types of reentry ballistic targets and identification of the true or fake warhead. This paper focus on an algorithm of reentry ballistic target tracking based on multiple model. In this scheme, the multiple model configuration is used for tracking the different types of reentry ballistic targets, thus improving the tracking accuracy effectively, and meanwhile, possessing the fast rate of convergence and better precision for the ballistic coefficient estimation. Simulation results indicate that this proposed method improves the precision of target tracking greatly, compared to the conventional EKF algorithm, and has especially a higher precision for the ballistic coefficient estimation and a certain capability of identifying the true or fake warhead and robust tracking performance.%再入弹道导弹目标的跟踪和识别是反导防御体系中最关键的问题。针对传统的跟踪方法不能适用于不同类型的再入弹道目标的跟踪和真假弹头的识别问题，提出一种基于多模型的再入段弹道目标跟踪算法。该算法采用多模型的结构，适用于跟踪不同类型的再入弹道目标，可有效地提高跟踪精度；同时对于弹道系数的估计具有很快的收敛速度和较好的估计精度。仿真结果表明，与传统的EKF算法相比较，本文算法大幅提高了目标跟踪的精度，特别在弹道系数估计上精度较高，具有一定的识别真假弹头的能力和鲁棒的跟踪性能。
Target Centroid Position Estimation of Phase-Path Volume Kalman Filtering
Directory of Open Access Journals (Sweden)
Fengjun Hu
2016-01-01
Full Text Available For the problem of easily losing track target when obstacles appear in intelligent robot target tracking, this paper proposes a target tracking algorithm integrating reduced dimension optimal Kalman filtering algorithm based on phase-path volume integral with Camshift algorithm. After analyzing the defects of Camshift algorithm, compare the performance with the SIFT algorithm and Mean Shift algorithm, and Kalman filtering algorithm is used for fusion optimization aiming at the defects. Then aiming at the increasing amount of calculation in integrated algorithm, reduce dimension with the phase-path volume integral instead of the Gaussian integral in Kalman algorithm and reduce the number of sampling points in the filtering process without influencing the operational precision of the original algorithm. Finally set the target centroid position from the Camshift algorithm iteration as the observation value of the improved Kalman filtering algorithm to fix predictive value; thus to make optimal estimation of target centroid position and keep the target tracking so that the robot can understand the environmental scene and react in time correctly according to the changes. The experiments show that the improved algorithm proposed in this paper shows good performance in target tracking with obstructions and reduces the computational complexity of the algorithm through the dimension reduction.
Xu, Wei-Heng; Feng, Zhong-Ke; Su, Zhi-Fang; Xu, Hui; Jiao, You-Quan; Deng, Ou
2014-02-01
Tree crown projection area and crown volume are the important parameters for the estimation of biomass, tridimensional green biomass and other forestry science applications. Using conventional measurements of tree crown projection area and crown volume will produce a large area of errors in the view of practical situations referring to complicated tree crown structures or different morphological characteristics. However, it is difficult to measure and validate their accuracy through conventional measurement methods. In view of practical problems which include complicated tree crown structure, different morphological characteristics, so as to implement the objective that tree crown projection and crown volume can be extracted by computer program automatically. This paper proposes an automatic untouched measurement based on terrestrial three-dimensional laser scanner named FARO Photon120 using plane scattered data point convex hull algorithm and slice segmentation and accumulation algorithm to calculate the tree crown projection area. It is exploited on VC+6.0 and Matlab7.0. The experiments are exploited on 22 common tree species of Beijing, China. The results show that the correlation coefficient of the crown projection between Av calculated by new method and conventional method A4 reaches 0.964 (p3D LIDAR point cloud data of individual tree, tree crown structure was reconstructed at a high rate of speed with high accuracy, and crown projection and volume of individual tree were extracted by this automatical untouched method, which can provide a reference for tree crown structure studies and be worth to popularize in the field of precision forestry.
Open-source algorithm for automatic choroid segmentation of OCT volume reconstructions
Mazzaferri, Javier; Beaton, Luke; Hounye, Gisèle; Sayah, Diane N.; Costantino, Santiago
2017-02-01
The use of optical coherence tomography (OCT) to study ocular diseases associated with choroidal physiology is sharply limited by the lack of available automated segmentation tools. Current research largely relies on hand-traced, single B-Scan segmentations because commercially available programs require high quality images, and the existing implementations are closed, scarce and not freely available. We developed and implemented a robust algorithm for segmenting and quantifying the choroidal layer from 3-dimensional OCT reconstructions. Here, we describe the algorithm, validate and benchmark the results, and provide an open-source implementation under the General Public License for any researcher to use (https://www.mathworks.com/matlabcentral/fileexchange/61275-choroidsegmentation).
Naqvi, Rizwan Ali; Park, Kang Ryoung
2016-06-01
Gaze tracking systems are widely used in human-computer interfaces, interfaces for the disabled, game interfaces, and for controlling home appliances. Most studies on gaze detection have focused on enhancing its accuracy, whereas few have considered the discrimination of intentional gaze fixation (looking at a target to activate or select it) from unintentional fixation while using gaze detection systems. Previous research methods based on the use of a keyboard or mouse button, eye blinking, and the dwell time of gaze position have various limitations. Therefore, we propose a method for discriminating between intentional and unintentional gaze fixation using a multimodal fuzzy logic algorithm applied to a gaze tracking system with a near-infrared camera sensor. Experimental results show that the proposed method outperforms the conventional method for determining gaze fixation.
Directory of Open Access Journals (Sweden)
A. M. Yusop
2017-02-01
Full Text Available This study presents the development of a novel maximum-power point-tracking (MPPT method based on an input shaping scheme controller. The proposed method that changes the initial input response into a shapeable MPPT algorithm is designed based on an exponential input function. This type of input function is selected because of its capability to stabilize the system at the end of the simulation time and remain at the same condition at the final response time. A comparison of the system with the proposed method and the system with traditional perturb and observe (PnO method is also provided. Results show that the system with the proposed method produces higher output power than the system with PnO method; the difference is approximately 15.45%. Results reveal that the exponential function input shaper allows the overall output system to exhibit satisfactory behavior and can efficiently track the maximum output power.
1989-08-01
tracking will be used for eye controlled switch selection, cueing, eye-slaved aiming, and pilot state monitoring. Current eye tracking technology is...panoramic display (VPD). Eye tracker measurements will be used with prototype systems to assist in candidate display evaluation. Operationally, eye
Dupnick, E.; Wiggins, D.
1980-01-01
The scheduling algorithm for mission planning and logistics evaluation (SAMPLE) is presented. Two major subsystems are included: The mission payloads program; and the set covering program. Formats and parameter definitions for the payload data set (payload model), feasible combination file, and traffic model are documented.
Tightly-coupled multi-sensor hybrid tracking algorithm%紧耦合多传感器混合跟踪算法
Institute of Scientific and Technical Information of China (English)
李薪宇; 陈东义
2011-01-01
在增强现实应用中实现对运动目标的准确跟踪是一个具有挑战性的任务.基于混合跟踪通过对多传感器信息的融合通常比单一传感器跟踪算法更为优越的特性,提出了一种新的紧耦合混合跟踪算法实现视觉与惯性传感器信息的实时融合.该算法基于多频率的测量数据同步,通过强跟踪滤波器引入时变衰减因子自适应调整滤波预测误差协方差,实现对运动目标位置数据的准确估计.通过标示物被遮挡状态下的跟踪实验结果表明,该方法能有效改善基于扩展卡尔曼滤波器的混合跟踪算法对运动目标位置信息预测估计的准确性,提高跟踪快速移动目标的稳定性,适用于大范围移动条件下的增强现实系统.%Accurate tracking for augmented reality applications is a challenging task. Multi-sensor hybrid tracking generally provides more stable resalts than single visual tracking. A new tightly-coupled hybrid tracking approach combining vision-based systems with an inertia] sensor is presented in this paper. Based on the multi-frequency sampling theory in the measurement data synchronization, a strong tracking filter is used to smooth sensor data and estimate the position and orientation. Through adding a time-varying fading factor to adaptively adjust the prediction error covariance of the filter, this method improves the performance of tracking for fast moving targets. Experimental results with occluded markers show that proposed approach can effectively improve the prediction accuracy of location information to target motion with the hybrid tracking algorithm based on the extended Kalman filter, improve the stability of fast moving target tracking. Our approach is suitable for a large range of mobile conditions.
Harris, Emma J.; Miller, Naomi R.; Bamber, Jeffrey C.; Symonds-Tayler, J. Richard N.; Evans, Philip M.
2010-06-01
We have evaluated a 4D ultrasound-based motion tracking system developed for tracking of abdominal organs during therapy. Tracking accuracy and precision were determined using a tissue-mimicking phantom, by comparing tracked motion with known 3D sinusoidal motion. The feasibility of tracking 3D liver motion in vivo was evaluated by acquiring 4D ultrasound data from four healthy volunteers. For two of these volunteers, data were also acquired whilst simultaneously measuring breath flow using a spirometer. Hepatic blood vessels, tracked off-line using manual tracking, were used as a reference to assess, in vivo, two types of automated tracking algorithm: incremental (from one volume to the next) and non-incremental (from the first volume to each subsequent volume). For phantom-based experiments, accuracy and precision (RMS error and SD) were found to be 0.78 mm and 0.54 mm, respectively. For in vivo measurements, mean absolute distance and standard deviation of the difference between automatically and manually tracked displacements were less than 1.7 mm and 1 mm respectively in all directions (left-right, anterior-posterior and superior-inferior). In vivo non-incremental tracking gave the best agreement. In both phantom and in vivo experiments, tracking performance was poorest for the elevational component of 3D motion. Good agreement between automatically and manually tracked displacements indicates that 4D ultrasound-based motion tracking has potential for image guidance applications in therapy.
Maric, Tomislav; Bothe, Dieter
2013-01-01
A new parallelized unsplit geometrical Volume of Fluid (VoF) algorithm with support for arbitrary unstructured meshes and dynamic local Adaptive Mesh Refinement (AMR), as well as for two and three dimensional computation is developed. The geometrical VoF algorithm supports arbitrary unstructured meshes in order to enable computations involving flow domains of arbitrary geometrical complexity. The implementation of the method is done within the framework of the OpenFOAM library for Computational Continuum Mechanics (CCM) using the C++ programming language with modern policy based design for high program code modularity. The development of the geometrical VoF algorithm significantly extends the method base of the OpenFOAM library by geometrical volumetric flux computation for two-phase flow simulations. For the volume fraction advection, a novel unsplit geometrical algorithm is developed, which inherently sustains volume conservation utilizing unique Lagrangian discrete trajectories located in the mesh points. ...
Williamson, Ben
2015-01-01
The emergence of digitized health and physical education, or "eHPE", embeds software algorithms in the organization of health and physical education pedagogies. Particularly with the emergence of wearable and mobile activity trackers, biosensors and personal analytics apps, algorithmic processes have an increasingly powerful part to play…
Wang, Ting-Shiuan; Yu, Teng-To; Lee, Shing-Tsz; Peng, Wen-Fei; Lin, Wei-Ling; Li, Pei-Ling
2014-09-01
Information regarding the scale of a hazard is crucial for the evaluation of its associated impact. Quantitative analysis of landslide volume immediately following the event can offer better understanding and control of contributory factors and their relative importance. Such information cannot be gathered for each landslide event, owing to limitations in obtaining useable raw data and the necessary procedures of each applied technology. Empirical rules are often used to predict volume change, but the resulting accuracy is very low. Traditional methods use photogrammetry or light detection and ranging (LiDAR) to produce a post-event digital terrain model (DTM). These methods are both costly and time-intensive. This study presents a technique to estimate terrain change volumes quickly and easily, not only reducing waiting time but also offering results with less than 25% error. A genetic algorithm (GA) programmed MATLAB is used to intelligently predict the elevation change for each pixel of an image. This deviation from the pre-event DTM becomes a candidate for the post-event DTM. Thus, each changed DTM is converted into a shadow relief image and compared with a single post-event remotely sensed image for similarity ranking. The candidates ranked in the top two thirds are retained as parent chromosomes to produce offspring in the next generation according to the rules of GAs. When the highest similarity index reaches 0.75, the DTM corresponding to that hillshade image is taken as the calculated post-event DTM. As an example, a pit with known volume is removed from a flat, inclined plane to demonstrate the theoretical capability of the code. The method is able to rapidly estimate the volume of terrain change within an error of 25%, without the delays involved in obtaining stereo image pairs, or the need for ground control points (GCPs) or professional photogrammetry software.
Mahmoodabadi, M J; Taherkhorsandi, M; Bagheri, A
2014-01-01
An optimal robust state feedback tracking controller is introduced to control a biped robot. In the literature, the parameters of the controller are usually determined by a tedious trial and error process. To eliminate this process and design the parameters of the proposed controller, the multiobjective evolutionary algorithms, that is, the proposed method, modified NSGAII, Sigma method, and MATLAB's Toolbox MOGA, are employed in this study. Among the used evolutionary optimization algorithms to design the controller for biped robots, the proposed method operates better in the aspect of designing the controller since it provides ample opportunities for designers to choose the most appropriate point based upon the design criteria. Three points are chosen from the nondominated solutions of the obtained Pareto front based on two conflicting objective functions, that is, the normalized summation of angle errors and normalized summation of control effort. Obtained results elucidate the efficiency of the proposed controller in order to control a biped robot.
Wang, Deyun; Grunder, Olivier; EL Moudni, Abdellah
2014-08-01
This paper considers an integrated lot sizing and scheduling problem for a production-distribution environment with arbitrary job volumes and distinct due dates considerations. In the problem, jobs are firstly batch processed on a batching machine at production stage and then delivered to a pre-specified customer at the subsequent delivery stage by a capacitated vehicle. Each job is associated with a distinct due date and a distinct volume, and has to be delivered to the customer before its due date, i.e. delay is not allowed. The processing time of a batch is a constant independent of the jobs it contains. In production, a constant set-up time as well as a constant set-up cost is required before the first job of this batch is processed. In delivery, a constant delivery time as well as a constant delivery cost is needed for each round-trip delivery between the factory and the customer. Moreover, it is supposed that a job that arrives at the customer before its due date will incur a customer inventory cost. The objective is to find a coordinated lot sizing and scheduling scheme such that the total cost is minimised while guaranteeing a certain customer service level. A mixed integer formulation is proposed for this problem, and then a genetic algorithm is developed to solve it. To evaluate the performance of the proposed genetic algorithm, a lower bound on the objective value is established. Computational experiments show that the proposed genetic algorithm performs well on randomly generated problem instances.
Carrier joint tracking algorithm for antenna array in GNSS%卫星导航天线阵的载波联合跟踪算法
Institute of Scientific and Technical Information of China (English)
吴舜晓; 黄仰博; 刘瀛翔; 欧钢
2015-01-01
测量卫星导航信号在天线阵各阵元上的载波相位之差可用于卫星波达方向解算，但传统的各阵元独立跟踪算法在干扰条件下无法实现高精度跟踪且容易失锁。针对此问题，通过将天线阵各阵元的载波相位分解为公共的平均载波相位和低动态的残余载波相位，提出了一种联合载波跟踪算法。该算法利用平均载波相位为每个阵元共有的特点，通过对全部阵元的联合处理来提高其跟踪精度，同时通过缩小环路噪声带宽来提高残余载波相位跟踪精度。理论分析与仿真结果表明，该算法提高了波达方向解算所需的阵元间载波相位差的测量精度及跟踪灵敏度，四阵元天线阵在典型应用条件下，跟踪灵敏度提高4dB，相同载噪比下载波相位差测量精度提高3倍。%Carrier phase difference measurements for the same satellite navigation signal at each antenna array elements can be used to solve its direction of arrival (DOA).However,traditional tracking algorithms can only adopt separate tracking loops for each separate antenna element when moderate interference is present;these algorithms cannot obtain precise measurements and frequently become lose of lock.Aim to solve these problems,a joint carrier tracking algorithm which decomposed each element′s carrier phase to the common average part and the low dynamic residual part was proposed.For the average carrier phase,as it is commonly shared by each array element,its tracking accuracy can be improved by combining all the observation values of the whole array elements.For the residual carrier phase,its tracking accuracy can be improved by reducing the loop noise bandwidth.Theoretical analysis and numerical simulation show that the algorithm can significantly improve the measurement accuracy of carrier phase difference between elements needed by DOA estimation and tracking sensitivity.The tracking sensitivity of a 4 element antenna
Maneuvering Target Tracking Algorithm Based on IMM-MKF%机动目标无源跟踪 IMM-MKF 算法
Institute of Scientific and Technical Information of China (English)
苏峰; 徐征; 张韫
2015-01-01
Aiming at improving the maneuvering target tracking performance using moving multiple pas-sive observer,a novel algorithm based on the interacting multiple model-marginalized Kalman filter(IMM-MKF)is proposed.The proposed algorithm combines the IMM with the MKF,which uses the MKF as the filter for each model and then the tracking results can be got by interacting effect with respect to the filtering results.The bearings-only maneuvering target is taken as an example to test the performance of the proposed algorithm.The simulation results indicate that the proposed algorithm has improved tracking performance, compared to typical IMM algorithms which use filters such as the extended Kalman filter(EKF),the un-scented Kalman filter(UKF)and the cubature Kalman filter(CKF).%为提高运动多站对机动目标的无源跟踪性能，提出了一种新的基于交互式多模型边缘化卡尔曼滤波(IMM-MKF)的机动目标跟踪算法。该算法将交互式多模型(IMM)结构和边缘化卡尔曼滤波(MKF)结合，利用 MKF 算法对每个模型进行滤波，对滤波结果进行交互作用来得到跟踪结果。以只测角机动目标跟踪为例对所提算法进行仿真分析，仿真结果表明，相对于采用扩展卡尔曼滤波(EKF)、不敏卡尔曼滤波(UKF)及容积卡尔曼滤波(CKF)算法的典型交互式多模型算法，所提算法具有更好的跟踪性能。
Targeting and tracking algorithm of humanoid soccer robot%一种仿人足球机器人目标定位与追踪算法
Institute of Scientific and Technical Information of China (English)
许家铭; 解仑; 王志良; 于国晨
2011-01-01
基于仿人足球机器人嵌入式系统结构,对目标定位和跟踪算法进行改进,提出一种适用于嵌入式全自主型机器人的颜色识别算法.首先,改进通用的颜色识别过程方法,添加目标特征统计学习,使足球机器人能够脱离PC机进行自主的目标颜色特征阈值设定;其次,简化基于嵌入式单目视觉系统下的目标定位算法,并通过扩大首帧搜索区域或加入形状检测的方法改进基于Camshift的目标跟踪算法,使其满足实时性和自主性;最后,在一个18自由度的仿人足球机器人上进行仿真和试验,在一定光照范围内,实际系统能够满足实时性和准确性的要求.结果表明:改进后的目标定位和跟踪算法及颜色识别过程具有较高的性能.%The target location and tracking algorithm was improved and a novel color recognition algorithm was proposed for autonomous robot based on the embedded structure of humanoid soccer robot system. Firstly, the common color identification method was improved by adding the statistical learning process of targeted color features in order to make the threshold of the object color features set by the soccer robot automatically instead of PC. Secondly, the target locating system based on embedded monocular vision system was simplified. The target tracking algorithm based on Camshift was improved by extending the first frame searching area or adding the shape check method. The real-time and autonomous requirement was met. Finally,the simulation and experiment on an 18-degree-freedom humanoid soccer robot was done. In a certain light range, the real-time performance and accuracy of the algorithm were verified. The results show that the improved target localization, tracking algorithm and color identification process have a high performance.
一种深度图像中人体的实时跟踪算法%A Human Body Real-time Tracking Algorithm in Depth Image
Institute of Scientific and Technical Information of China (English)
曹昊; 诸宸辰; 李杨
2013-01-01
This paper proposes an improving Camshift algorithm based on depth data in order to realize real-time human body objects tracking in depth image. This algorithm computes depth probability distribution function of human body objects, combining the morphological characteristics of people. Different weight factors are given to the different part of human on depth probability distribution function. It finds human body objects in a frame after several times of iterations, uses the modified Camshift algorithm. Kalman filter is also applied in this work to predict the position of people in 3D space. Doing experiments on 1 200 frames of depth image, results present that this algorithm are effective to track moving human body on depth image even though the objects are partly covered or the shapes are regular changed. For the common one or two people situation, the tracking accuracy rate is over 95%, which is better than traditional Camshift algorithm.%针对深度图像中的人体目标跟踪问题，提出一种基于深度图像的改进Camshift算法。利用人体目标的深度信息计算概率分布，结合人体形态学特征，对深度的概率分布赋予不同的权重，通过Camshift算法进行迭代，从而寻找目标，使用卡尔曼滤波器在三维空间中对运动人体目标的位置实现预测和更新。采集1200帧图像进行测试，结果表明，该算法能实时准确地跟踪深度图像中的运动人体目标，有效克服遮挡等干扰，单人和双人跟踪准确率均在95%以上，高于传统Camshift算法。
Falkowski, Paul G.; Behrenfeld, Michael J.; Esaias, Wayne E.; Balch, William; Campbell, Janet W.; Iverson, Richard L.; Kiefer, Dale A.; Morel, Andre; Yoder, James A.; Hooker, Stanford B. (Editor); Firestone, Elaine R. (Editor)
1998-01-01
Two issues regarding primary productivity, as it pertains to the Sea-viewing Wide Field-of-view Sensor (SeaWiFS) Program and the National Aeronautics and Space Administration (NASA) Mission to Planet Earth (MTPE) are presented in this volume. Chapter 1 describes the development of a science plan for deriving primary production for the world ocean using satellite measurements, by the Ocean Primary Productivity Working Group (OPPWG). Chapter 2 presents discussions by the same group, of algorithm classification, algorithm parameterization and data availability, algorithm testing and validation, and the benefits of a consensus primary productivity algorithm.
Atik, L.; Petit, P.; Sawicki, J. P.; Ternifi, Z. T.; Bachir, G.; Della, M.; Aillerie, M.
2017-02-01
Solar panels have a nonlinear voltage-current characteristic, with a distinct maximum power point (MPP), which depends on the environmental factors, such as temperature and irradiation. In order to continuously harvest maximum power from the solar panels, they have to operate at their MPP despite the inevitable changes in the environment. Various methods for maximum power point tracking (MPPT) were developed and finally implemented in solar power electronic controllers to increase the efficiency in the electricity production originate from renewables. In this paper we compare using Matlab tools Simulink, two different MPP tracking methods, which are, fuzzy logic control (FL) and sliding mode control (SMC), considering their efficiency in solar energy production.
TRIM: A finite-volume MHD algorithm for an unstructured adaptive mesh
Energy Technology Data Exchange (ETDEWEB)
Schnack, D.D.; Lottati, I.; Mikic, Z. [Science Applications International Corp., San Diego, CA (United States)] [and others
1995-07-01
The authors describe TRIM, a MHD code which uses finite volume discretization of the MHD equations on an unstructured adaptive grid of triangles in the poloidal plane. They apply it to problems related to modeling tokamak toroidal plasmas. The toroidal direction is treated by a pseudospectral method. Care was taken to center variables appropriately on the mesh and to construct a self adjoint diffusion operator for cell centered variables.
Ataş, Halil; Kepez, Alper; Tigen, Kürşat; Samadov, Fuad; Özen, Gülsen; Cincin, Altuğ; Sünbül, Murat; Bozbay, Mehmet; Direşkeneli, Haner; Başaran, Yelda
2016-05-01
The aim of the present study was to evaluate left atrial (LA) volume and functions using real-time three-dimensional echocardiography (RT3DE) and speckle tracking in systemic sclerosis (SSc) patients. The study was designed as a cross-sectional observational study. We studied 41 consecutive SSc patients (38 females, mean age: 49.5±11.6 years) and 38 healthy controls (35 females, mean age: 48.5±10.8 years). Patients with evidence or history of cardiovascular disease and patients with risk factors as hypertension, diabetes and chronic renal failure were excluded from the study. All study subjects underwent standard echocardiography; LA speckle tracking and RT3DE was performed to assess LA volume and phasic functions. Differences between numeric variables were tested using the independent sample Student's t-test or Mann-Whitney U test, where appropriate. There were no significant differences between SSC patients and controls regarding left ventricular (LV) systolic functions and two-dimensional (2-D) atrial diameters. Presence of LV diastolic dysfunction (LVDD) was evaluated and graded according to recommendations of the American Society of Echocardiography. Accordingly, LVDD was observed to be significantly more frequent in SSc patients; 16 SSc patients (39%) and 5 controls (12.8%) were observed to have LVDD (p=0.007). With regard to results obtained from RT3DE, LA maximum, minimum, and before atrial contraction volumes were significantly higher (40.5±14.6 vs. 32.6±8.9, 15.5±8.4 vs. 9.9±3.5 and 28.7±11.7 vs. 21.4±7.0 mL respectively, pspeckle tracking echocardiography, atrial peak-systolic longitudinal strain (ε), early negative strain rate (SR), late negative SR, and peak positive SR values were observed to be significantly lower in SSc patients. LA volumes were significantly increased, and LA reservoir, conduit, and contractile functions were significantly impaired in SSc patients compared with controls. LA volume and functional analyses with RT3DE and
An Infrared Object Tracking Algorithm of Multi-feature Fusion%一种多特征融合的红外目标跟踪算法
Institute of Scientific and Technical Information of China (English)
卞志国; 姚源源
2012-01-01
针对红外序列图像中各类目标及背景特征动态变化的特性,提出一种基于二值分类技术的多特征融合目标跟踪算法.分别根据灰度、纹理及梯度方向特征将图像分为背景与目标区域,并根据各类特征分类性能的差异,融合特征图像,通过重采样粒子滤波估计目标状态.实验结果表明,该算法对环境光照变化、局部遮挡等均具有较好的鲁棒性.%Due to the various types of dynamic changes of background and foreground characteristics during object tracking in infrared image sequences, this paper proposes an object tracking algorithm of multi-feature fusion based on binary classification. The scene is classified into object and background region based on characteristics such as intensity, texture and grad orientation. The likelihood map is combined with the weights corresponding to classification performance respectively. A re-sampling particle filter is employed to estimate the object state. Experimental results show that the proposed algorithm is robust to environmental illumination and partial occlusions.
PEBB Feedback Control Low Library. Volume 1: Three-Phase Inverter Control Algorithms
1999-01-01
ship propulsion electrical loads are powered from a common set of prime movers. Presently, the current generation of PEBB-like devices include high-power, fast-switching, high-bandwidth dc-dc converters and dc-ac inverters. This report summarized the algorithms required to control a conventional three-phase inverter. First, implementation issues regarding the Sine-Triangle Pulse-Width-Modulation and Space-Vector Modulation are presented with an emphasis placed on digital realizations. Then, two current control schemes are documented via analysis, design example, and
AUV 同时定位与跟踪算法研究%Algorithms research of simultaneous localization and tracking for AUVs
Institute of Scientific and Technical Information of China (English)
王闯; 卢健; 黄杰
2014-01-01
For enhancing the adaptive capacity of autonomous underwater vehicles (AUV) ,simultaneous localization and tracking (SLAT ) algorithms based on the EKF‐SLAM framework and the FastSLAM framework for AUVs was proposed by comparing the concepts of target tracking and cooperative naviga‐tion ,and imitating simultaneous localization and mapping (SLAM ) .The simultaneous localization and tracking for an AUV in the unknown environment refers to that the sonar sensors of the AUV equipped with low precise proprioceptive localization sensors are used to detect a non‐cooperative target continu‐ously and estimate the track of the target .At the same time ,the cumulative estimate errors brought by the method of the dead reckoning are corrected by utilizing the relative information between the AUV and the target ,and then the localization accuracy of the AUV is improved .The localization of the AUV and state estimate of the target are carried ,and they are interdependent and influencing each other and must have a certain accuracy both .At last ,the accuracy of two proposed algorithms are compared by the simulation ,and the validity and the consistency of the algorithm was shown .%为了提高自治水下航行器的水下适应能力，对比目标跟踪与协同导航的概念，并仿照同时定位与制图方法，提出了基于EKF‐SLAM 框架和FastSLAM 框架的自治水下航行器同时定位与跟踪算法。根据装备在携带低精度自定位传感器 AUV上的声纳传感器持续探测非合作目标并估计目标航迹的同时，利用探测到的AUV与目标间的相对信息修正其自身航位推算带来的累积估计误差，从而提高AUV的自定位精度，AUV的定位和目标的状态估计同时进行，且要满足一定的精度。仿真比较了所提出的两种算法的精度，并验证了算法的有效性和一致性。
A New Tracking Algorithm of Near Space Hypersonic Targets%一种新的临近空间高超声速目标跟踪算法
Institute of Scientific and Technical Information of China (English)
李凡; 毕红葵; 段敏
2016-01-01
针对变结构多模型算法(VSMM)在模型集自适应转换过程中，模型集选取容易出现只在单一类型模型中选取的问题，提出一种基于模型集匹配程度检测激活不同类模型的方法。在连续4个滤波周期没有激活不同类模型时，对每个周期所使用模型集与真实运动模式进行匹配程度检测，以此决定是否激活不同类模型。该方法既能有效解决模型转换的缺陷，同时避免了因单个滤波周期内检测判决导致算法切换频繁的问题。仿真结果表明，对比传统算法改进算法能有效提高跟踪性能。%A new tracking algorithm of near space hypersonic target is proposed aimed at the problem that the multiple model algorithms are prone to choose only one single type of models in the process of adaptive conversion based on the degree of model matching.In four non-activated filter period of different models, detections of model matching between real-time model set and real motion model are used to decide wheth-er to activate different classes of models.By so doing,the algorithm effectively solves not only the defects in the model transformation but also the decreasing robustness of the algorithm caused by the j udgment in single filter period.The simulation results show that the improved algorithm can effectively improve the tracking performance compared with the traditional algorithm.
Implementation of Eye Movement Tracking System Based on Camshift Algorithm%基于Camshift算法的眼动跟踪系统的实现
Institute of Scientific and Technical Information of China (English)
黄春瑞; 吕学全; 赵冀; 任秋实; 柴新禹
2009-01-01
介绍了的眼动跟踪系统分为硬件检测、数据提取和综合分析三个步骤.其算法基础为基于Camshift目标跟踪算法的改进算法,加入了眼动跟踪计算模块,以VC++6.0为开发语言实现.该系统在基于假体视觉的模拟光幻视点定位实验中可有效地进行眼动跟踪.%In this article, the implementation of eye movement tracking system includes three procedures: hardware acquisition, data extraction and overall analysis.The system is based on Camshift algorithm with an eye tracking module added, developed on VC++ 6.0.The system can track the eye movement effectively in simulated phosphene evaluation experiment based on prosthetic vision.
The Research for Pedestrian Tracking Algorithm in Color Invariance%颜色不变量空间下的行人跟踪算法研究
Institute of Scientific and Technical Information of China (English)
张述照; 阮秋琦; 安高云
2014-01-01
为了有效的克服遮挡问题准确跟踪行人，本文提出了一种通过不断学习新的外观模型来自适应跟踪行人的跟踪算法。该算法首先将颜色不变量特征平面作为根特征来表示初始特征空间；然后将跟踪问题转化为0或1的二进制问题，通过局部最小二乘法（PLS）来对目标外观特征和对应的类型标签进行建模得到前景和背景的模板。随着目标外观的变化，本文利用局部最小二乘法（PLS ）在颜色不变量平面上分析多个外观特征的样本信息，不断的更新模板，从而达到对遮挡具有很好鲁棒性的行人跟踪效果。通过对通用数据集进行试验表明：该算法在颜色暗淡和颜色鲜明的视频图片中都能达到很好的跟踪效果。%In order to overcome occlusion and track the pedestrian accurately,this paper proposes an object tracking al-gorithm that learns a set of new appearance models for adaptive discriminative object representation.First,we exploit the color invariance as the root feature to obtain the appearance feature.And then,object tracking is taken as a binary classifi-cation problem.The correlation of object appearance and class labels from foreground and background is modeled by the a-nalysis from partial least squares,to generate a low-dimensional discriminative feature.As object appearance varies,we learn and adapt a series of appearance models with PLS analysis to achieve the robustness for tracking.Experiments on gen-eral data sets demonstrate good performance of the proposed tracking algorithm.
Efficient Rectangular Maximal-Volume Algorithm for Rating Elicitation in Collaborative Filtering
Fonarev, Alexander
2017-02-07
Cold start problem in Collaborative Filtering can be solved by asking new users to rate a small seed set of representative items or by asking representative users to rate a new item. The question is how to build a seed set that can give enough preference information for making good recommendations. One of the most successful approaches, called Representative Based Matrix Factorization, is based on Maxvol algorithm. Unfortunately, this approach has one important limitation - a seed set of a particular size requires a rating matrix factorization of fixed rank that should coincide with that size. This is not necessarily optimal in the general case. In the current paper, we introduce a fast algorithm for an analytical generalization of this approach that we call Rectangular Maxvol. It allows the rank of factorization to be lower than the required size of the seed set. Moreover, the paper includes the theoretical analysis of the method\\'s error, the complexity analysis of the existing methods and the comparison to the state-of-the-art approaches.
Tracking for near space target based on IMM algorithm%基于交互式多模型算法跟踪临近空间目标
Institute of Scientific and Technical Information of China (English)
秦雷; 李君龙; 周荻
2014-01-01
Due to the current maneuvering target model is developing towards more and more modular and parallel computing,which puts forward higher requirements for calculation efficiency of algorithm.For high su-personic maneuvering targets in near space,it is often tracked with multiform maneuvering target models,since precision of single target maneuvering model cannot satisfy the requirement of tracking.So it is necessary to use the interactive multiple model algorithm for cross coupling based on a variety of models.The characteristic of this algorithm is adapted to that of high speed and high maneuver for near space target.At the same time,con-sidering the filtering result of extended Kalman filter (EKF)algorithm for strong nonlinear targets is bad,un-scented Kalman filter (UKF)algorithm can be solved very well for this problem.So through simulation contrast experiment of two kinds of algorithms,it proves that interacting multiple model-unscented Kalman filter (IMM-UKF) algorithm guarantees the target tracking accuracy is within the allowable range,validity of the algorithm is veri-fied with Matlab simulation results.%由于目前机动目标模型越来越向模块化、并行计算的方向发展，对目前算法计算效率提出了更高的要求。对于临近空间超声速机动目标一般采用多种机动模型跟踪，单一模型已经很难满足高精度跟踪的需要。因此需要使用基于多种模型进行交叉耦合的交互式多模型（interacting multiple model，IMM）算法，这种算法特点与临近空间目标高速、高机动特性相适应。同时考虑到扩展卡尔曼滤波（extended Kalman filter，EKF）算法对强非线性对象滤波效果不好，无迹卡尔曼滤波（unscented Kalman filter，UKF）算法对于此类问题，可以很好地加以解决。仿真对比试验表明，交互式多模型无迹卡尔曼滤波（interacting multiple model-unscented Kalman filter， IMM-UKF）算法优于单一模型 EKF 算法。
Institute of Scientific and Technical Information of China (English)
居耀勇; 陈黎
2012-01-01
应用图像处理与识别技术,提出基于主方向迭代校正的铁轨检测算法.该算法基于梯度图像的Hough变换估计出路轨的主方向,设计出边缘检测算子,实现边缘增强、突出铁轨的位置信息.通过算法迭代得到最优边缘检测算子,利用主方向信息与路轨判定准则进行铁轨的定位.结果表明,该算法能准确有效地进行铁轨的检测与定位.%Making use of image processing and recognition technology, this paper presents an iterative principal orientation adjustment-based algorithm for railway track detection. This algorithm utilizes Hough transform of the gradient images to arrive at the principal orientation of the railway track, and designs the optimal edge detector to achieve edge enhancement and reveal the railway track in the images. The principal orientation of the railway track is corrected when the algorithm iterates several times, and the location of the railway track is determined on the basis of the principal orientation and the rule of railway track features. Experimental results have confirmed the robustness and effectiveness of the proposed algorithm.
Object Tracking Algorithm for Binary WSN Based on APF%基于APF的二元WSN运动目标跟踪算法
Institute of Scientific and Technical Information of China (English)
朱金芳; 张晓莺; 范一鸣
2012-01-01
针对传感节点计算、通信及资源受限的特点,引入二元WSN模型,提出了一种基于辅助粒子滤波(APF)的集中式算法,以实现运动目标的实时跟踪.由于每个二元传感器只对目标是否进入其感知区域做出反应(向数据融合中心报告0或1),粒子滤波算法的复杂运算集中在融合中心完成,因此节点结构简单、通信代价低廉,有助于延长监测网络的生存周期.仿真实验结果表明,该算法对随机部署和规则部署的两种方案,均具有良好的跟踪性能,能满足一般机动目标实时跟踪的应用要求.%Wireless sensor networks have to operate with sensors that have limited power as well as limited communication and computational resources. A binary sensor network model is introduced in this paper, and also a centralized particle filters algorithm based on APF(au.\\iliary particle filters) for moving object tracking is proposed. Because the binary sensor transmits only binary information about sensed events (the object entered or not entered its sensing area), the fusion center receives these signals and then running PF algorithm in it, so the cost of communication is limited and the sensor is very simple. The simulation experiment indicated that, this algorithm shows good tracking performance in all with deterministicaUy and randomly deployed sensor.
基于路径栅格的机场噪声等值线追踪算法%Airport Noise Isoline Tracking Algorithm Based on Route Grid
Institute of Scientific and Technical Information of China (English)
徐涛; 曹枝东
2013-01-01
机场噪声等值线图在机场噪声控制、机场规划设计中起着重要的作用。针对机场噪声的特征及分布特点，提出了一种基于路径栅格的机场噪声等值线追踪算法，通过构造有效网格、建立具有顶点编码和的路径栅格，在等值线追踪过程中唯一确定下一个等值点，避免了传统的先开放后封闭的等值线追踪方式，能够快速生成等值线图。实验验证表明，该算法效率高，绘制的机场噪声等值线图效果好，没有等值线交叉现象。%The airport noise isoline map plays an important role in airport noise control and airport planning. After studying airport noise characteristics and distribution, an airport noise isoline tracking algorithm based on route grid is proposed. By constructing an effective grid and creating route grid with the point code sum, the next equivalent point can be determined definitely in isoline tacking. The proposed algorithm can generate the isoline map rapidly by avoiding open isoline tracking first and then closed one Experimental results show that the proposed algorithm has more efficient performance, and generates the better airport noise isoline map, especially with no cross between isolines.
AUTHOR|(INSPIRE)INSPIRE-00389298; The ATLAS collaboration
2016-01-01
With the increase in energy of the LHC to $\\sqrt{s}=13$~TeV for run 2, events with dense environments become much more abundant. These environments are characterized by charged particle separations of the order of ATLAS inner detector sensor dimensions and can be created by the decay of boosted objects. The performance of the track reconstruction in these extreme conditions is presented using Monte Carlo Simulation. Further, the inefficiency of the track reconstruction in the core of jets as a function of the transverse momentum of the jet between 200 GeV and 1600 GeV, using proton-proton data collected by the ATLAS experiment at a center-of-mass energy of $\\sqrt{s}=13$~TeV is discussed.
Thermal Tracking of Sports Players
DEFF Research Database (Denmark)
Gade, Rikke; Moeslund, Thomas B.
2014-01-01
We present here a real-time tracking algorithm for thermal video from a sports game. Robust detection of people includes routines for handling occlusions and noise before tracking each detected person with a Kalman filter. This online tracking algorithm is compared with a state-of-the-art offline...... approach. Furthermore, the combined detection and tracking algorithm runs in real time at 33 fps, even with large image sizes of 1920 × 480 pixels....
DEFF Research Database (Denmark)
Pommer, Tobias; Falk, Marianne; Poulsen, Per Rugaard
2013-01-01
during the first 75 s. A research DMLC tracking system was used for real-time motion compensation with optical monitoring for position input. The gamma index was used for evaluation, with measurements with a static phantom or the planned dose as reference, using 2% and 2 mm gamma criteria. The average......This study investigated the dosimetric impact of uncompensated motion and motion compensation with dynamic multileaf collimator (DMLC) tracking for prostate intensity modulated arc therapy. Two treatment approaches were investigated; a conventional approach with a uniform radiation dose...... done with and without DMLC tracking on a linear acceleration with a high-resolution MLC. A cylindrical phantom containing two orthogonal diode arrays was used for dosimetry. A motion platform reproduced six patient-derived prostate motion traces, with the average displacement ranging from 1.0 to 8.9 mm...
一种新的机动目标跟踪算法%A new maneuvering target tracking algorithm
Institute of Scientific and Technical Information of China (English)
李泽强; 陈龙驹
2012-01-01
针对UKF算法精度较高,但计算负担繁重的问题,基于对精度与实时性考虑,提出了UKF与径向基神经网络相结合的模型与机动目标跟踪算法.通过计算机模拟仿真,证明了该算法的可行性.%Considered the high accuracy of UKF algorithm and the heavy burden, a new model and algorithm that UKF incorporated in RBF neural networks were presented based on the accuracy and die real time. The simulation results show that the algorithm is available.
DEFF Research Database (Denmark)
Hermansson, Henrik Alf Jonas; Cross, James
2015-01-01
based upon minimum edit distances. We demonstrate the usefulness of two language-insensitive, transparent, and efficient minimum-edit-distance algorithms suited for the task. These algorithms are capable of providing an account of the types (insertions, deletions, substitutions, and transpositions......) and substantive amount of amendments made between version of texts. To illustrate the usefulness and eciency of the approach we replicate two existing studies from the field of legislative studies. Our results demonstrate that minimum edit distance methods can produce superior measures of text amendments to hand...
DEFF Research Database (Denmark)
Farhang, Peyman; Drimus, Alin; Mátéfi-Tempfli, Stefan
2015-01-01
the optimal solutions is run in MATLAB while it is interfaced with LTspice for simulation of the circuit using actual component models obtained from manufacturers. The PSO is utilized to solve the optimization problem in order to find the optimal parameters of MPID and PID controllers. The performances......In this paper, a new technique is proposed to design a Modified PID (MPID) controller for a Boost converter. An interface between LTspice and MATLAB is carried out to implement the Particle Swarm Optimization (PSO) algorithm. The PSO algorithm which has the appropriate capability to find out...
Algorithms and computer codes for atomic and molecular quantum scattering theory. Volume I
Energy Technology Data Exchange (ETDEWEB)
Thomas, L. (ed.)
1979-01-01
The goals of this workshop are to identify which of the existing computer codes for solving the coupled equations of quantum molecular scattering theory perform most efficiently on a variety of test problems, and to make tested versions of those codes available to the chemistry community through the NRCC software library. To this end, many of the most active developers and users of these codes have been invited to discuss the methods and to solve a set of test problems using the LBL computers. The first volume of this workshop report is a collection of the manuscripts of the talks that were presented at the first meeting held at the Argonne National Laboratory, Argonne, Illinois June 25-27, 1979. It is hoped that this will serve as an up-to-date reference to the most popular methods with their latest refinements and implementations.
Directory of Open Access Journals (Sweden)
Leonardo W. T. Silva
2014-08-01
Full Text Available In launching operations, Rocket Tracking Systems (RTS process the trajectory data obtained by radar sensors. In order to improve functionality and maintenance, radars can be upgraded by replacing antennas with parabolic reflectors (PRs with phased arrays (PAs. These arrays enable the electronic control of the radiation pattern by adjusting the signal supplied to each radiating element. However, in projects of phased array radars (PARs, the modeling of the problem is subject to various combinations of excitation signals producing a complex optimization problem. In this case, it is possible to calculate the problem solutions with optimization methods such as genetic algorithms (GAs. For this, the Genetic Algorithm with Maximum-Minimum Crossover (GA-MMC method was developed to control the radiation pattern of PAs. The GA-MMC uses a reconfigurable algorithm with multiple objectives, differentiated coding and a new crossover genetic operator. This operator has a different approach from the conventional one, because it performs the crossover of the fittest individuals with the least fit individuals in order to enhance the genetic diversity. Thus, GA-MMC was successful in more than 90% of the tests for each application, increased the fitness of the final population by more than 20% and reduced the premature convergence.
基于CamShift的手势跟踪算法的定点实现%Fixed-Point Implementation of Gesture Tracking Algorithm Based on CamShift
Institute of Scientific and Technical Information of China (English)
廖凌宇
2012-01-01
在OpenCV 1．0中CamShift浮点算法的基础上，对算法进行定点实现。介绍CamShift算法的基本原理，详细阐述对CamShift浮点程序定点化的方案、流程和具体方法。定点化结果表明，定点化后程序与原浮点程序偏差较小。满足跟踪性能的要求．可用于下一步的硬件实现。%Describes the fixed-point implementation of CamShift algorithm based on OpenCV 1.0. Intro- duces the basic principles of the CamShift algorithm, and elaborates the float-point to fixed- point program and flow of CamShift algorithm. The result of experimentation shows that the de- viation between the float-point and fixed-point is small, can meet the requirement of tracking application, and can be used to the hardware implementation of next step.
视线跟踪系统中眼睛睁闭检测算法研究%Eye state detection algorithm of eye tracking system
Institute of Scientific and Technical Information of China (English)
邓宏平; 李斌; 姚鹏; 吴伟; 王建宇; 庄镇泉
2012-01-01
眼睛睁闭检测在视线跟踪系统中具有重要意义.为提高检测的准确性,提出了一种基于Harris算子的检测方法.该方法首先利用Harris算子计算图像的角点量,然后搜索图像中角点量最大的位置,以该位置为中心,设置一个区域,统计该区域内角点量总和占整幅图像角点量总和的比例,通过将该比例与阈值相比较来确定眼睛的状态.实验结果表明,本算法具有较高的鲁棒性和准确率,并能满足实时性要求.%Eye state detection is important in eye tracking system. In order to improve the correctness, a Harris operator based new algorithm is proposed. First, Harris operator is used to calculate the cornerness of eye image. Then, the position of maximum cornerness is set as center of a region. The proportion of total cornerness in the region and all images are used to detect eye state. Experimental results definitely verify the robustness and accuracy of the new algorithm. Especially, this new algorithm is suitable for real-time applications.
Rumerman, Judy A.
2000-01-01
This sixth volume of the NASA Historical Data Book is a continuation of those earlier efforts. This fundamental reference tool presents information, much of it statistical, documenting the development of several critical areas of NASA responsibility for the period between 1979 and 1988. This volume includes detailed information on the space applications effort, the development and operation of aeronautics and space research and technology programs, tracking and data acquisition/space operations, commercial programs, facilities and installations, personnel, and finances and procurement during this era. Special thanks are owed to the student research assistants who gathered and input much of the tabular material-a particularly tedious undertaking. There are numerous people at NASA associated with historical study, technical information, and the mechanics of publishing who helped in myriad ways in the preparation of this historical data book.
Pallez, Denis; Baccino, Thierry; Dumercy, Laurent
2008-01-01
In this paper, we describe a new algorithm that consists in combining an eye-tracker for minimizing the fatigue of a user during the evaluation process of Interactive Evolutionary Computation. The approach is then applied to the Interactive One-Max optimization problem.
AGATA - Advanced GAmma Tracking Array
Energy Technology Data Exchange (ETDEWEB)
Akkoyun, S. [Department of Physics, Faculty of Science, Ankara University, 06100 Tandogan, Ankara (Turkey); Algora, A. [IFIC, CSIC-Universitat de Valencia, E-46980 Paterna (Spain); Alikhani, B. [IKP, TU Darmstadt, Schlossgartenstrasse 9, D-64289 Darmstadt (Germany); Ameil, F. [GSI Helmholtzzentrum fuer Schwerionenforschung GmbH, D-64291 Darmstadt (Germany); Angelis, G. de [INFN Laboratori Nazionali di Legnaro, IT-35020 Padova (Italy); Arnold, L. [Universite de Strasbourg, IPHC, 23 rue du Loess, 67037 Strasbourg (France); CNRS, UMR 7178, 67037 Strasbourg (France); Astier, A. [CSNSM, CNRS, IN2P3, Universite Paris-Sud, F-91405 Orsay (France); Atac, A. [Department of Physics, Faculty of Science, Ankara University, 06100 Tandogan, Ankara (Turkey); Department of Physics and Astronomy, Uppsala University, Uppsala (Sweden); Royal Institute of Technology, SE-10691 Stockholm (Sweden); Aubert, Y. [IPNO, CNRS/IN2P3, Universite Paris-Sud, F-91406 Orsay (France); Aufranc, C. [Universite de Lyon, Universite Lyon 1, CNRS-IN2P3, Institut de Physique Nucleaire de Lyon, F-69622 Villeurbanne (France); Austin, A. [STFC Daresbury Laboratory, Daresbury, Warrington WA4 4AD (United Kingdom); Aydin, S. [INFN Sezione di Padova, IT-35131 Padova (Italy); Azaiez, F. [IPNO, CNRS/IN2P3, Universite Paris-Sud, F-91406 Orsay (France); Badoer, S. [INFN Laboratori Nazionali di Legnaro, IT-35020 Padova (Italy); Balabanski, D.L. [Institute for Nuclear Research and Nuclear Energy, Bulgarian Academy of Sciences, Sofia (Bulgaria); Barrientos, D. [IFIC, CSIC-Universitat de Valencia, E-46980 Paterna (Spain); and others
2012-03-11
The Advanced GAmma Tracking Array (AGATA) is a European project to develop and operate the next generation {gamma}-ray spectrometer. AGATA is based on the technique of {gamma}-ray energy tracking in electrically segmented high-purity germanium crystals. This technique requires the accurate determination of the energy, time and position of every interaction as a {gamma} ray deposits its energy within the detector volume. Reconstruction of the full interaction path results in a detector with very high efficiency and excellent spectral response. The realisation of {gamma}-ray tracking and AGATA is a result of many technical advances. These include the development of encapsulated highly segmented germanium detectors assembled in a triple cluster detector cryostat, an electronics system with fast digital sampling and a data acquisition system to process the data at a high rate. The full characterisation of the crystals was measured and compared with detector-response simulations. This enabled pulse-shape analysis algorithms, to extract energy, time and position, to be employed. In addition, tracking algorithms for event reconstruction were developed. The first phase of AGATA is now complete and operational in its first physics campaign. In the future AGATA will be moved between laboratories in Europe and operated in a series of campaigns to take advantage of the different beams and facilities available to maximise its science output. The paper reviews all the achievements made in the AGATA project including all the necessary infrastructure to operate and support the spectrometer.
2014-11-01
on the queries and corpora are described as follows: 1https://github.com/lintool/ twitter -tools/wiki/TREC- 2013- API -Specifications • Non-English...query expansion and (2) web-based query expansion. In twitter corpus based query expansion, we first use TREC- API to get the top ranked tweet set. Then...the official corpus via a common API . Tweet Timeline Generation (TTG) is a new task for this year’s Microblog track with a putative user model as
Energy Technology Data Exchange (ETDEWEB)
Juergens, Kai Uwe; Maintz, David; Heimes, Britta; Fallenberg, Eva Maria; Heindel, Walter; Fischbach, Roman [University of Muenster, Department of Clinical Radiology, Muenster (Germany); Grude, Matthias [University of Muenster, Department of Cardiology and Angiology, Muenster (Germany); Boese, Jan M. [Siemens Medical Solutions, Forchheim (Germany)
2005-01-01
A multi-segment cardiac image reconstruction algorithm in multi-detector row computed tomography (MDCT) was evaluated regarding temporal resolution and determination of left ventricular (LV) volumes and global LV function. MDCT and cine magnetic resonance (CMR) imaging were performed in 12 patients with known or suspected coronary artery disease. Patients gave informed written consent for the MDCT and the CMR exam. MDCT data were reconstructed using the standard adaptive cardiac volume (ACV) algorithm as well as a multi-segment algorithm utilizing data from three, five and seven rotations. LV end-diastolic (LV-EDV) and end-systolic volumes and ejection fraction (LV-EF) were determined from short-axis image reformations and compared to CMR data. Mean temporal resolution achieved was 192{+-}24 ms using the ACV algorithm and improved significantly utilizing the three, five and seven data segments to 139{+-}12, 113{+-}13 and 96{+-}11 ms (P<0.001 for each). Mean LV-EDV was without significant differences using the ACV algorithm, the multi-segment approach and CMR imaging. Despite improved temporal resolution with multi-segment image reconstruction, end-systolic volumes were less accurately measured (mean differences 3.9{+-}11.8 ml to 8.1{+-}13.9 ml), resulting in a consistent underestimation of LV-EF by 2.3-5.4% in comparison to CMR imaging (Bland-Altman analysis). Multi-segment image reconstruction improves temporal resolution compared to the standard ACV algorithm, but this does not result in a benefit for determination of LV volume and function. (orig.)
2011-08-02
resources aimed at increasing household literacy practices. Proceedings of the 2011 AFMS Medical Research Symposium Volume 6 Traumatic Brain Injury...temperature regulation sexual function Dysfunction leads to or exacerbates: Hypertension Obesity Diabetes Depression Stroke and heart attack
Mccreary, T.
1983-01-01
A parametric description of the communication channels required between the user spacecraft to be supported and the user ground data systems is developed. Scenarios of mission models, which reflect a range of free flyers vs space platform usage as well as levels of NASA activity and potential support for military missions, and potential channel requirements which identify: (1) bounds on TDAS forward and return link data communication demand, and (2) the additional demand for providing navigation/tracking support are covered.
Harmonics tracking of intracranial and arterial blood pressure waves.
Shahsavari, Sima; McKelvey, Tomas
2008-01-01
Considering cardiorespiratory interaction and heart rate variability, a new approach is proposed to decompose intracranial pressure and arterial blood pressure to their different harmonics. The method is based on tracking the amplitudes of the harmonics by a Kalman filter based tracking algorithm. The algorithm takes benefit of combined frequency estimation technique which uses both Fast Fourier Transform and RR-interval detection. The result would be of use in intracranial pressure and arterial blood pressure waveform analysis as well as other investigations which need to estimate contribution of specific harmonic in above mentioned signals such as Pressure-Volume Compensatory Reserve assessment.
A Single Filter Tracking Algorithm Based on Neural Network%神经网络的单滤波器目标跟踪算法
Institute of Scientific and Technical Information of China (English)
阮怀林; 王树亮
2011-01-01
当前统计模型及其自适应滤波(CSMAF)算法是机动目标跟踪中的一种有效方法.但该方法对目标机动加速度极限值有依赖,并且对弱机动目标跟踪的精度不高.为解决这一问题,利用一种改进的加速度方差自适应调整公式克服了对加速度极限值的依赖,同时利用神经网络对滤波参数信息进行融合,自适应调整过程噪声.仿真结果表明,该方法有很好的机动适应性,对目标的跟踪精度较高.%The Current Statistical Model and Adaptive Filtering (CSMAF) algorithm is one of the most effective methods for tracking the maneuvering targets. However, its performance suffers from the shortcoming of its heavy dependence on the choice of limit acceleration. Also, it has a lower precision in tracking the weak maneuvering target. For solving this problem, one improved self-adaptive formula for acceleration variance is proposed to overcome the dependence on the limit acceleration. At the same time, the neural network is used to fuse the filtering parameters information and self-adjust the process noise. Simulation results show that the proposed method has better adaptability for maneuvering and has higher precision for tracking.
Alves, D.; Coelho, R.; JET-EFDA Contributors
2013-08-01
The real-time tracking of instantaneous quantities such as frequency, amplitude, and phase of components immerse in noisy signals has been a common problem in many scientific and engineering fields such as power systems and delivery, telecommunications, and acoustics for the past decades. In magnetically confined fusion research, extracting this sort of information from magnetic signals can be of valuable assistance in, for instance, feedback control of detrimental magnetohydrodynamic modes and disruption avoidance mechanisms by monitoring instability growth or anticipating mode-locking events. This work is focused on nonlinear Kalman filter based methods for tackling this problem. Similar methods have already proven their merits and have been successfully employed in this scientific domain in applications such as amplitude demodulation for the motional Stark effect diagnostic. In the course of this work, three approaches are described, compared, and discussed using magnetic signals from the Joint European Torus tokamak plasma discharges for benchmarking purposes.
基于 CUDA 的细分曲面阴影体算法%CUDA based shadow volume algorithm for subdivision surfaces
Institute of Scientific and Technical Information of China (English)
赵杰伊; 唐敏; 童若锋
2012-01-01
为了在虚拟现实、电脑游戏等图形应用中更快速生成和实时绘制细分曲面的阴影,提出采用CUDA架构的GPU阴影体生成算法.该算法采用基于CUDA的曲面细分算法,通过CUDA共享内存结构使表面细分过程更加高效.采用基于CUDA的阴影体算法产生阴影轮廓线以及拉伸出阴影体.通过基于CUDA的流式缩减算法对阴影体数组进行压缩.通过优化CUDA和OpenGL的互操作,将绘制过程从以往算法的3步减少为2步.该算法在具有CUDA硬件的标准PC上进行测试.实验结果表明,与之前的GPU的算法相比,该算法可以生成更复杂细分曲面的阴影体,阴影体数组占用显存空间降低到2％以下,并可获得高达4倍的绘制速度提升.%A new GPU based shadow volume generation algorithm based on CUDA structure was proposed for fast generation and real-time rendering of shadow of subdivision surfaces in computer games and virtual reality applications. The algorithm introduces CUDA-based surface subdivision algorithm. Generation of surface subdivisions can run faster by using shared memory structure. CUDA-based shadow volume algorithm was introduced to generate the shadow silhouette line and extrude the shadow volume. CUDA-based stream reduction algorithm was introduced to reduce the shadow volume array. An optimized interopera-tion between CUDA and OPENGL was introduced to simplify the rendering step of the algorithm from three steps to two steps. Implemented on a standard PC with CUDA hardware, experiments show that the algorithm can generate the shadow volume of more complex subdivision surfaces compared with former GPU-based ones. The algorithm needs smaller video memory for the shadow volume array to less than 2%, and the rendering performance can gain acceleration up to more than four times.
Mean shift object tracking algorithm based on discriminative ranked list%基于判别式序列表的均值漂移目标跟踪算法
Institute of Scientific and Technical Information of China (English)
蒋良卫; 桑农; 刘乐元
2011-01-01
针对目标周围的背景信息对目标跟踪算法的影响,基于判别式序列表提出了一种改进的均值漂移目标跟踪算法.利用目标外观特征来描述目标模型与候选目标,同时通过判别式序列表对目标外观建模并对目标周围的背景信息进行描述.基于均值漂移跟踪框架,把目标外观模型与判别式序列表目标外观模型相结合来改进传统的均值漂移跟踪算法.在几个图像序列上对提出的算法与均值漂移算法进行了测试.实验结果表明:本算法能改善传统均值漂移跟踪算法,较均值漂移算法有更高的跟踪精度和更具鲁棒性的跟踪效果.%As for the interference of the background information around the tracking object, an improved mean shift tracking algorithm was proposed based on discriminative ranked list, in which, the object template and candidate objects were represented using the object appearance feature and the discriminative ranked list was employed to model for the object appearance information and describe the background information around the object being tracked. Based on the framework of mean shift tracking algorithm, we integrated the object appearance and the discriminative ranked list object model to improve the traditional mean shift tracking algorithm by means of reducing the interference of the background information. Finally, the proposed tracking approach and the mean shift tracking algorithm were tested on several image sequences. The experimental results show that the proposed method can improve the mean shift tracking algorithm effectively and has higher tracking accuracy and more robust tracking efficiency.
Institute of Scientific and Technical Information of China (English)
王宜贤; 石德乐; 杨宁
2016-01-01
In order to track high-speed UAVs in real time, the visual tracking algorithms need to satisfy the requirements of accuracy and rapidity. In this paper, a fusion algorithm was presented that combined the advantages of two typical algo⁃rithms, frame difference and Mean shift. The two algorithms were run simultaneously the frame difference was used for rap⁃id tracking, while Mean shift was used for improving the precision of the tracking of frame difference. To get more precise tracking, the Kalman filter was used to compensate the displacement of UAVs moving during the implement of the tracking algorithm. The effectiveness of fusion algorithm was illustrated by a simulation example in Matlab environment.%为实时跟踪高速飞行无人机，图像跟踪算法必须满足快速性和准确性要求。文章给出一个融合算法，将帧差法和Mean shift算法的优势结合起来。2个算法平行运行，差帧法实现快速跟踪，Mean shift算法则用于对帧差法结果进行准确度修正。还利用Kalman滤波技术对计算周期内的无人机运动位移进行补偿，进一步提高实时跟踪的准确性，并给出Matlab仿真例子验证本文方法的有效性。
Kim, Hie-Sik; Nam, Chul; Ha, Kwan-Yong; Ayurzana, Odgeral; Kwon, Jong-Won
2005-12-01
The embedded systems have been applied to many fields, including households and industrial sites. The user interface technology with simple display on the screen was implemented more and more. The user demands are increasing and the system has more various applicable fields due to a high penetration rate of the Internet. Therefore, the demand for embedded system is tend to rise. An embedded system for image tracking was implemented. This system is used a fixed IP for the reliable server operation on TCP/IP networks. Using an USB camera on the embedded Linux system developed a real time broadcasting of video image on the Internet. The digital camera is connected at the USB host port of the embedded board. All input images from the video camera are continuously stored as a compressed JPEG file in a directory at the Linux web-server. And each frame image data from web camera is compared for measurement of displacement Vector. That used Block matching algorithm and edge detection algorithm for past speed. And the displacement vector is used at pan/tilt motor control through RS232 serial cable. The embedded board utilized the S3C2410 MPU, which used the ARM 920T core form Samsung. The operating system was ported to embedded Linux kernel and mounted of root file system. And the stored images are sent to the client PC through the web browser. It used the network function of Linux and it developed a program with protocol of the TCP/IP.
Directory of Open Access Journals (Sweden)
Francesco Marchese
2017-05-01
Full Text Available Dust outbreaks are meteorological phenomena of great interest for scientists and authorities (because of their impact on the climate, environment, and human activities, which may be detected, monitored, and characterized from space using different methods and procedures. Among the recent dust detection algorithms, the RSTDUST multi-temporal technique has provided good results in different geographic areas (e.g., Mediterranean basin; Arabian Peninsula, exhibiting a better performance than traditional split window methods, in spite of some limitations. In this study, we present an optimized configuration of this technique, which better exploits data provided by Spinning Enhanced Visible and Infrared Imager (SEVIRI aboard Meteosat Second Generation (MSG satellites to address those issues (e.g., sensitivity reduction over arid and semi-arid regions; dependence on some meteorological clouds. Three massive dust events affecting Europe and the Mediterranean basin in May 2008/2010 are analysed in this work, using information provided by some independent and well-established aerosol products to assess the achieved results. The study shows that the proposed algorithm, christened eRSTDUST (i.e., enhanced RSTDUST, which provides qualitative information about dust outbreaks, is capable of increasing the trade-off between reliability and sensitivity. The results encourage further experimentations of this method in other periods of the year, also exploiting data provided by different satellite sensors, for better evaluating the advantages arising from the use of this dust detection technique in operational scenarios.
Wielicki, Bruce A. (Principal Investigator); Barkstrom, Bruce R. (Principal Investigator); Baum, Bryan A.; Cess, Robert D.; Charlock, Thomas P.; Coakley, James A.; Green, Richard N.; Lee, Robert B., III; Minnis, Patrick; Smith, G. Louis
1995-01-01
The theoretical bases for the Release 1 algorithms that will be used to process satellite data for investigation of the Clouds and the Earth's Radiant Energy System (CERES) are described. The architecture for software implementation of the methodologies is outlined. Volume 1 provides both summarized and detailed overviews of the CERES Release 1 data analysis system. CERES will produce global top-of-the-atmosphere shortwave and longwave radiative fluxes at the top of the atmosphere, at the surface, and within the atmosphere by using the combination of a large variety of measurements and models. The CERES processing system includes radiance observations from CERES scanning radiometers, cloud properties derived from coincident satellite imaging radiometers, temperature and humidity fields from meteorological analysis models, and high-temporal-resolution geostationary satellite radiances to account for unobserved times. CERES will provide a continuation of the ERBE record and the lowest error climatology of consistent cloud properties and radiation fields. CERES will also substantially improve our knowledge of the Earth's surface radiation budget.
Directory of Open Access Journals (Sweden)
D. Slobinsky
2015-03-01
Full Text Available We implement the Wang-Landau algorithm to sample with equal probabilities the static configurations of a model granular system. The "non-interacting rigid arch model" used is based on the description of static configurations by means of splitting the assembly of grains into sets of stable arches. This technique allows us to build the entropy as a function of the volume of the packing for large systems. We make a special note of the details that have to be considered when defining the microstates and proposing the moves for the correct sampling in these unusual models. We compare our results with previous exact calculations of the model made at moderate system sizes. The technique opens a new opportunity to calculate the entropy of more complex granular models. Received: 19 January 2015, Accepted: 25 February 2015; Reviewed by: M. Pica Ciamarra, Nanyang Technological University, Singapore; Edited by: C. S. O'Hern; DOI: http://dx.doi.org/10.4279/PIP.070001 Cite as: D Slobinsky, L A Pugnaloni, Papers in Physics 7, 070001 (2015
Institute of Scientific and Technical Information of China (English)
钟必能; 潘胜男
2016-01-01
提出一种基于深度学习的多模型（卷积神经网络和卷积深信度网络）融合目标跟踪算法．该算法在提取候选粒子方面，使用选择性搜索和粒子滤波的方法．CVPR2013跟踪评价指标（50个视频序列、30个跟踪算法）验证了：该算法在跟踪中能有效地缓解目标物体由于遮挡、光照变化和尺度变化等因素造成的跟踪丢失情况的发生．%A multi-clue tracking algorithm (convolutional neural network and convolutional deep belief network)based on deep learning was proposed.The algorithm used selective search and particle filtering method in extracting candidate particles.CVPR2013 tracking benchmark (50 video sequences,30 tracking algorithms)verifies:the algorithm can ease the loss of tracking due to the occlusion,the change of illumination and size etc.
Shrestha, Kalyan; Mompean, Gilmar; Calzavarini, Enrico
2016-02-01
A finite-volume (FV) discretization method for the lattice Boltzmann (LB) equation, which combines high accuracy with limited computational cost is presented. In order to assess the performance of the FV method we carry out a systematic comparison, focused on accuracy and computational performances, with the standard streaming lattice Boltzmann equation algorithm. In particular we aim at clarifying whether and in which conditions the proposed algorithm, and more generally any FV algorithm, can be taken as the method of choice in fluid-dynamics LB simulations. For this reason the comparative analysis is further extended to the case of realistic flows, in particular thermally driven flows in turbulent conditions. We report the successful simulation of high-Rayleigh number convective flow performed by a lattice Boltzmann FV-based algorithm with wall grid refinement.
Triplet based online track finding in the PANDA-STT
National Research Council Canada - National Science Library
Mertens, Marius; Caldeira Balkeståhl, Li; Calén, Hans; Fransson, Kjell; Johansson, Tord; Kupsc, Andrzej; Marciniewski, Pawel; Schönning, Karin; Pettersson, Joachim; Wolke, Magnus; Zmeskal, Johann
2014-01-01
.... A variety of tracking algorithms is foreseen to process the different track topologies. The so-called Triplet Finder, which is presented here, is a track finding algorithm based on the central straw tube tracker (STT) of PANDA...
Energy Technology Data Exchange (ETDEWEB)
McHugh, P.R.
1995-10-01
Fully coupled, Newton-Krylov algorithms are investigated for solving strongly coupled, nonlinear systems of partial differential equations arising in the field of computational fluid dynamics. Primitive variable forms of the steady incompressible and compressible Navier-Stokes and energy equations that describe the flow of a laminar Newtonian fluid in two-dimensions are specifically considered. Numerical solutions are obtained by first integrating over discrete finite volumes that compose the computational mesh. The resulting system of nonlinear algebraic equations are linearized using Newton`s method. Preconditioned Krylov subspace based iterative algorithms then solve these linear systems on each Newton iteration. Selected Krylov algorithms include the Arnoldi-based Generalized Minimal RESidual (GMRES) algorithm, and the Lanczos-based Conjugate Gradients Squared (CGS), Bi-CGSTAB, and Transpose-Free Quasi-Minimal Residual (TFQMR) algorithms. Both Incomplete Lower-Upper (ILU) factorization and domain-based additive and multiplicative Schwarz preconditioning strategies are studied. Numerical techniques such as mesh sequencing, adaptive damping, pseudo-transient relaxation, and parameter continuation are used to improve the solution efficiency, while algorithm implementation is simplified using a numerical Jacobian evaluation. The capabilities of standard Newton-Krylov algorithms are demonstrated via solutions to both incompressible and compressible flow problems. Incompressible flow problems include natural convection in an enclosed cavity, and mixed/forced convection past a backward facing step.
Institute of Scientific and Technical Information of China (English)
董跃钧; 李国伟
2013-01-01
In order to solve the problem of the diversity of particles degradation, improving wireless sensor network ( WSN) target tracking accuracy, a target tracking method based on particle filter optimized by quantum genetic algorithm is proposed. Quantum genetic algorithm not only increases the diversity of particles to prevent the particle degeneracy phenomenon, and improves the estimation, tracking ability and effectively shortens the calculation time. The simulation results show that the proposed algorithm is very good, reduced particle degradation on the target tracking accuracy, improves the WSN target tracking accuracy and real-time tracking, the tracking results is satisfactory.%在无线传感器网络(WSN)目标跟踪应用中,传统粒子滤波算法存在多样性退化问题.为提高WSN目标跟踪精度,提出一种基于量子遗传算法优化粒子滤波的WSN目标跟踪方法.量子遗传算法不仅增加粒子多样性,防止粒子退化现象出现,有效缩短了计算时间且改善粒子跟踪能力.测试结果表明,所提出算法很好地减轻了粒子退化对目标跟踪精度影响,提高了WSN目标跟踪精度和跟踪的实时性,跟踪结果令人满意.
Energy Technology Data Exchange (ETDEWEB)
Maier, Joscha, E-mail: joscha.maier@dkfz.de [Medical Physics in Radiology, German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120 Heidelberg (Germany); Sawall, Stefan; Kachelrieß, Marc [Medical Physics in Radiology, German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120 Heidelberg, Germany and Institute of Medical Physics, University of Erlangen–Nürnberg, 91052 Erlangen (Germany)
2014-05-15
Purpose: Phase-correlated microcomputed tomography (micro-CT) imaging plays an important role in the assessment of mouse models of cardiovascular diseases and the determination of functional parameters as the left ventricular volume. As the current gold standard, the phase-correlated Feldkamp reconstruction (PCF), shows poor performance in case of low dose scans, more sophisticated reconstruction algorithms have been proposed to enable low-dose imaging. In this study, the authors focus on the McKinnon-Bates (MKB) algorithm, the low dose phase-correlated (LDPC) reconstruction, and the high-dimensional total variation minimization reconstruction (HDTV) and investigate their potential to accurately determine the left ventricular volume at different dose levels from 50 to 500 mGy. The results were verified in phantom studies of a five-dimensional (5D) mathematical mouse phantom. Methods: Micro-CT data of eight mice, each administered with an x-ray dose of 500 mGy, were acquired, retrospectively gated for cardiac and respiratory motion and reconstructed using PCF, MKB, LDPC, and HDTV. Dose levels down to 50 mGy were simulated by using only a fraction of the projections. Contrast-to-noise ratio (CNR) was evaluated as a measure of image quality. Left ventricular volume was determined using different segmentation algorithms (Otsu, level sets, region growing). Forward projections of the 5D mouse phantom were performed to simulate a micro-CT scan. The simulated data were processed the same way as the real mouse data sets. Results: Compared to the conventional PCF reconstruction, the MKB, LDPC, and HDTV algorithm yield images of increased quality in terms of CNR. While the MKB reconstruction only provides small improvements, a significant increase of the CNR is observed in LDPC and HDTV reconstructions. The phantom studies demonstrate that left ventricular volumes can be determined accurately at 500 mGy. For lower dose levels which were simulated for real mouse data sets, the
多假设跟踪的移动机器人SLAM算法%SLAM algorithm based on multi-hypothesis tracking for mobile robots
Institute of Scientific and Technical Information of China (English)
杨敬辉; 杨晶东
2013-01-01
With respect to pose candidates, resulted from autonomous localization for mobile robots based on vision measurement, this paper proposed an approach to SLAM based on Multi-hypothesis tracking. The approach extracts SIFT features of image for vision measurement, modifies the accumulative odometric error, and acquires the optimal pose from pose candidates using Multi-hypothesis tracking algorithm. At the same time the occupancy map of the environment is built and updated according to the transformation of robot pose. The experiment shows the localization method can not only build the environment map in real-time, but also solve the robot “kidnapping”, and improve the accuracy of autonomous localization.% 针对基于视觉定位的移动机器人自主定位过程中容易产生多种候选位姿。提出一种基于多假设跟踪的同时定位和地图创建方法。该方法通过提取图像SIFT特征进行视觉量测，修正里程计累计误差，再利用多假设跟踪方法获得当前时刻的最优位姿，实时产生环境的栅格地图，并且随着机器人的位姿变化实时更新。研究结果表明：此算法不仅能够较好地创建环境地图，而且能够有效解决机器人“绑架”问题，提高自主定位精度。
Eye tracking method on improved CamShift algorithm%改进CamShift算法的眼动跟踪方法
Institute of Scientific and Technical Information of China (English)
HUANG Yuan-gang; SANG Nan; HAO Zong-bo; JIANG Wei
2014-01-01
Since the CamShift algorithm only adopted color feature， which would result in the inaccuracy or failure of eye tracking in the situation of similar color objects，rapid movement of the head or deformation of the iris， this paper proposed an eye tracking m%针对CamShift跟踪算法仅采用颜色特征，在存在颜色相近干扰目标、头部快速运动或者虹膜发生形变等情况易发生眼动跟踪不准确或失败等问题，提出一种基于改进CamShift算法的眼动跟踪方法。在CamShift算法中，计算边缘直方图分布，在颜色特征基础上融合边缘特征，同时通过分析饱和度分量抑制噪声影响，并利用基于边缘特征的自定义方法判断虹膜是否发生形变。当发生形变时，自动更新模板，根据历史运动轨迹预测虹膜中心。实验表明，该方法能有效改善眼动跟踪性能，且定位虹膜精确、错误率低、速度快，预测虹膜中心与实际虹膜中心
Video-based lane detection and tracking algorithm%基于视频序列的车道线检测和跟踪
Institute of Scientific and Technical Information of China (English)
朱淋; 梁华为; 王智灵; 邓耀
2013-01-01
The lane detection is a critical technology for unmanned driving system and a series of driving assistance systems.Traditional lane detection algorithms are easily disturbed by the other traffic lines on the road.A new method for lane detection and tracking is put forward in this paper.First,the adaptive image threshold algorithm is adopted for lane features extraction.By means of setting the ROI twice and planning the tracking region,the ROI decreases gradually.At last,the feature points in the ROI are transformed from the image coordinate system to the real-world coordinate system before they are used to accomplish curve fitting through least square method.Experiments under various conditions,such as highway and urban environments,show that the method proposed in this paper is able to accurately recognize the lane marks in real time and effectively eliminate the disturbance of the other traffic line markings.%车道线检测是无人驾驶系统以及一系列辅助驾驶系统的关键技术环节.传统的车道线检测方法容易受到其他交通标志线干扰,提出了一种新的车道线检测与跟踪方法.该方法首先使用自适应阈值算法提取特征,通过ROI二次设置以及跟踪区域规划,逐步减小感兴趣区域,最后将感兴趣区域内的特征点从图像坐标系转换到世界坐标系下,以最小二乘方法进行曲线拟合.在高速公路及城区道路等多种工况下的实验表明,提出的方法能够正确实时的识别出车道线,有效的消除了其他交通标线的干扰.
A Simultaneous Facial Motion Tracking and Expression Recognition Algorithm%一种同步人脸运动跟踪与表情识别算法
Institute of Scientific and Technical Information of China (English)
於俊; 汪增福; 李睿
2015-01-01
In view of facial expression recognition from monocular video with dynamic background ,a real-time system was proposed based on the algorithm in which facial motion is tracked and facial expression is recognized simultaneously .Firstly ,online appearance model and cylinder head model were combined to track 3D facial motion from video in framework of particle filtering ;secondly ,the static knowledge of facial expression was extracted through facial expression anatomy ;thirdly ,the dynamic knowledge of facial expression was extracted through manifold learning ;fourthly ,facial expression was retrieved by fusing the static knowledge and dynamic knowledge during facial motion tracking process .The experiments results confirmed the advantage on facial expression recognition even in the presence of significant head pose and facial expression variations of this system .%针对单视频动态变化背景下的人脸表情识别问题，提出了一种同步人脸运动跟踪和表情识别算法，并在此基础上构建了一个实时系统。该系统达到了如下目标：首先在粒子滤波框架下结合在线外观模型和柱状几何模型进行人脸三维运动跟踪；接着基于生理知识来提取人脸表情的静态信息；然后基于流形学习来提取人脸表情的动态信息；最后在人脸运动跟踪过程中，结合人脸表情静态信息和动态信息来进行表情识别。实验结果表明，该系统在大姿态和丰富表情下具有较好的综合优势。
基于遗传算法改进的太阳能跟踪控制%Improved Solar Tracking Control Modes Based on Genetic Algorithm
Institute of Scientific and Technical Information of China (English)
甘屹; 郭家忠; 王子健; 陈成; 曾乐才; 杨家荣
2015-01-01
提出采用基于遗传算法的选择机制与吸热塔能量变化的反馈机制相结合的方式对光热电站的太阳能跟踪控制系统进行改进，以光热电站中少数几台配备光电检测元件的定日镜控制角度为基准，控制其他定日镜的角度调整。实验表明，改进的太阳能跟踪控制方式在保证光热电站整体控制精度的基础上，减少了光电检测元件的安装数量，降低了电站构建成本；同时使得控制系统在运行视日轨迹跟踪控制时具有自动调整能力。该研究将降低大规模光热电站的构建费用，促进太阳能光热发电的发展。%This paper adopts the combination of the selection mechanism of genetic algorithm and feedback mechanism of the changes of heat absorption tower energy to improve solar tracking control system. With solar thermal power plant which is equipped with photoelectric detecting element heliostat control angle as a benchmark, this paper proposes to control the adjustment of other heliostat angles. Experiments show that the improved way of solar tracking control reduced the number of the installation of photoelectric detecting elements and the costs of solar thermal power plant construction, while the overall control precision is without falling. At the same time the control system has the ability of automatic adjustment when it operating on the depending on trajectory tracking control. The study will reduce the costs of large-scale solar thermal power plant construction, promote the development of solar thermal power generation.
Tracking tumor boundary in MV-EPID images without implanted markers: A feasibility study
Energy Technology Data Exchange (ETDEWEB)
Zhang, Xiaoyong, E-mail: xiaoyong@ieee.org; Homma, Noriyasu, E-mail: homma@ieee.org [Department of Radiological Imaging and Informatics, Tohoku University Graduate School of Medicine, Sendai 980-8579 (Japan); Ichiji, Kei, E-mail: ichiji@yoshizawa.ecei.tohoku.ac.jp [Research Institute of Electrical Communication, Tohoku University, Sendai 980-8579 (Japan); Takai, Yoshihiro, E-mail: y-takai@cc.hirosaki-u.ac.jp [Department of Radiology and Radiation Oncology, Hirosaki University Graduate School of Medicine, Hirosaki 036-8562 (Japan); Yoshizawa, Makoto, E-mail: yoshizawa@yoshizawa.ecei.tohoku.ac.jp [Research Division on Advanced Information Technology, Cyberscience Center, Tohoku University, Sendai 980-8579 (Japan)
2015-05-15
Purpose: To develop a markerless tracking algorithm to track the tumor boundary in megavoltage (MV)-electronic portal imaging device (EPID) images for image-guided radiation therapy. Methods: A level set method (LSM)-based algorithm is developed to track tumor boundary in EPID image sequences. Given an EPID image sequence, an initial curve is manually specified in the first frame. Driven by a region-scalable energy fitting function, the initial curve automatically evolves toward the tumor boundary and stops on the desired boundary while the energy function reaches its minimum. For the subsequent frames, the tracking algorithm updates the initial curve by using the tracking result in the previous frame and reuses the LSM to detect the tumor boundary in the subsequent frame so that the tracking processing can be continued without user intervention. The tracking algorithm is tested on three image datasets, including a 4-D phantom EPID image sequence, four digitally deformable phantom image sequences with different noise levels, and four clinical EPID image sequences acquired in lung cancer treatment. The tracking accuracy is evaluated based on two metrics: centroid localization error (CLE) and volume overlap index (VOI) between the tracking result and the ground truth. Results: For the 4-D phantom image sequence, the CLE is 0.23 ± 0.20 mm, and VOI is 95.6% ± 0.2%. For the digital phantom image sequences, the total CLE and VOI are 0.11 ± 0.08 mm and 96.7% ± 0.7%, respectively. In addition, for the clinical EPID image sequences, the proposed algorithm achieves 0.32 ± 0.77 mm in the CLE and 72.1% ± 5.5% in the VOI. These results demonstrate the effectiveness of the authors’ proposed method both in tumor localization and boundary tracking in EPID images. In addition, compared with two existing tracking algorithms, the proposed method achieves a higher accuracy in tumor localization. Conclusions: In this paper, the authors presented a feasibility study of tracking
Energy Technology Data Exchange (ETDEWEB)
Nishimura, Yoshihiro; Katafuchi, Tetsuro; Hirase, Yoshinori; Sagoh, Masayoshi; Oka, Hisashi [National Cardiovascular Center, Suita, Osaka (Japan); Mori, Hideaki [Siemens-Asahi Medical Technologies, Ltd., Tokyo (Japan); Murase, Kenya [Osaka Univ., Suita (Japan). Medical School
2002-12-01
Quantitative gated SPECT (QGS) software has been reported to demonstrate inaccurate edge detection in the left ventricular chamber in hypertrophic cardiomyopathy patients. In this study we developed a method to calculate left ventricular volume (LVV) and left myocardial volume (LMV) from gated SPECT data using a newly developed edge-detection algorithm, and we compared it with the QGS method of calculating LVV and LMV in a phantom study. Our method gave more accurate measurements LVV and LMV whereas the QGS method underestimated LMV. Compared with QGS LVV and LMV, our method yielded better results in the phantom study. (author)
Institute of Scientific and Technical Information of China (English)
陈家波; 赵勋杰; 许峥
2012-01-01
基于梯度方向直方图特征的运动目标跟踪算法在遇到目标遮挡或运动过快时容易丢失目标,基于粒子滤波跟踪算法虽有较强的抗遮挡能力,但存在着计算量大、实时性差等问题.针对这些情况,提出一种融合的跟踪方法;正常情况下基于目标梯度方向直方图特征跟踪目标,当候选目标相似度小于设定阈值时,自动切换到粒子滤波跟踪算法.实验结果显示本算法有效地解决了目标遮挡或运动过快时的丢失问题,同时减轻了粒子的退化现象,提高了算法的实时性,并在图像对比度较低情况下能较好的跟踪目标.%Since Kernel based object tracking algorithm using histograms of oriented gradients always loses object under the conditions of occlusion or fast motion and particle filter tracking algorithm costs huge computation time, a kernel based tracking algorithm integrated with particle filter is proposed. Under normal circumstances, the object is tracked by the algorithm based on Histograms of Oriented Gradient, when the conformability of candidate object is less than the threshold,the tracking result would be verified by particle filter algorithm. The experiments show that the algorithm effectively solves the problem of the object-loss under the conditions of occlusion or fast motion, the algorithm is with a better real time quality and also overcomes the particle-degeneracy problem and can get good tracking results under low-contrast conditions.
Thermal Tracking of Sports Players
Directory of Open Access Journals (Sweden)
Rikke Gade
2014-07-01
Full Text Available We present here a real-time tracking algorithm for thermal video from a sports game. Robust detection of people includes routines for handling occlusions and noise before tracking each detected person with a Kalman filter. This online tracking algorithm is compared with a state-of-the-art offline multi-target tracking algorithm. Experiments are performed on a manually annotated 2-minutes video sequence of a real soccer game. The Kalman filter shows a very promising result on this rather challenging sequence with a tracking accuracy above 70% and is superior compared with the offline tracking approach. Furthermore, the combined detection and tracking algorithm runs in real time at 33 fps, even with large image sizes of 1920 × 480 pixels.
Accelerated Algorithm of Ray Castingin Medical Volume Rendering%医学体绘制的一种快速光线投射算法
Institute of Scientific and Technical Information of China (English)
牛翠霞; 范辉; 杜慧秋
2006-01-01
The accelerated direct volume rendering algorithm in medical data sets was discussed. Based on several accelerated techniques of DVR, an efficient ray-casting algorithm was proposed which improved the traditional ray-casting algorithm. The algorithm mainly applies methods of polygon scan conversion and voxelization of casting rays. The algorithm uses the method of determining the convex hull of a set and the intersecting algorithm related directly to x,y, z family planes to clip data sets and rays.%针对医学体数据场的直接体绘制(DVR)的加速算法进行了讨论.基于体绘制的多种加速技术,利用格雷厄姆求凸壳算法和与平面簇求交算法对体数据场和投射光线进行裁剪,结合多边形的扫描线转换和投射光线的离散化、体素化,改进了光线投射算法.
DEFF Research Database (Denmark)
Østergaard, Leif; Smith, D F; Vestergaard-Poulsen, Peter;
1998-01-01
The authors determined cerebral blood flow (CBF) with magnetic resonance imaging (MRI) of contrast agent bolus passage and compared the results with those obtained by O-15 labeled water (H215O) and positron emission tomography (PET). Six pigs were examined by MRI and PET under normo......- and hypercapnic conditions. After dose normalization and introduction of an empirical constant phi Gd, absolute regional CBF was calculated from MRI. The spatial resolution and the signal-to-noise ratio of CBF measurements by MRI were better than by the H215O-PET protocol. Magnetic resonance imaging cerebral...... blood volume (CBV) estimates obtained using this normalization constant correlated well with values obtained by O-15 labeled carbonmonooxide (C15O) PET. However, PET CBV values were approximately 2.5 times larger than absolute MRI CBV values, supporting the hypothesized sensitivity of MRI to small...
Institute of Scientific and Technical Information of China (English)
梁少帅; 邱涤珊; 谈群
2011-01-01
为提高目标密集环境下航迹关联的正确率,提出了基于先验知识与记忆信息的航迹关联聚类算法.对来自不同传感器的航迹进行自动聚类,并根据单个传感器中不同航迹代表不同目标这一先验知识,对目标数目过多的聚类进行处理.另外,算法考虑了航迹关联中的记忆信息,提高了航迹关联的准确性,有效地解决了目标密集环境下的误关联问题.仿真结果表明了该算法的有效性.%A track correlation clustering algorithm based on priori knowledge and memory information was proposed to improve the accuracy of track correlation in a target-intensive environment. The tracks derived from different sensors were clustered, the clusters which had too many targets were processed using the priori knowledge (the different tracks in one sensor represent different targets). Additionally, the memory information was introduced to improve the accuracy of track correlation, effectively solve the problem of false correlation in the target-intensive environment. The validity of the algorithm was proved through simulation results.
Johnson, Perry L.; Hamilton, Stephen S.; Burns, Randal; Meneveau, Charles
2017-01-01
An intrinsic property of turbulent flows is the exponential deformation of fluid elements along Lagrangian paths. The production of enstrophy by vorticity stretching follows from a similar mechanism in the Lagrangian view, though the alignment statistics differ and viscosity prevents unbounded growth. In this paper, the stretching properties of fluid elements and vorticity along Lagrangian paths are studied in a channel flow at Reτ=1000 and compared with prior known results from isotropic turbulence. To track Lagrangian paths in a public database containing direct numerical simulation results, the task-parallel algorithm previously employed in the isotropic database is extended to the case of flow in a bounded domain. It is shown that above 100 viscous units from the wall, stretching statistics are equal to their isotropic values, in support of the local isotropy hypothesis. In the viscous sublayer, these stretching statistics approach values more consistent with an unsteady two-dimensional shear flow, in which exponential stretching no longer occurs. Normalized by dissipation rate, the stretching in the buffer layer and below is less efficient due to less favorable alignment statistics. The Cramér function characterizing cumulative Lagrangian stretching statistics shows that overall the channel flow has about half of the stretching per unit dissipation compared with isotropic turbulence.
A Robust and Efficient Facial Feature Tracking Algorithm%一种鲁棒高效的人脸特征点跟踪方法
Institute of Scientific and Technical Information of China (English)
黄琛; 丁晓青; 方驰
2012-01-01
人脸特征点跟踪能获取除粗略的人脸位置和运动轨迹以外的人脸部件的精确信息,对计算机视觉研究有重要作用.主动表象模型(Active appearance model,AAM)是描述人脸特征点位置的最有效的方法之一,但是其高维参数空间和梯度下降优化策略使得AAM对初始参数敏感,且易陷入局部极值.因此,基于传统AAM的人脸特征点跟踪方法不能同时较好地解决大姿态、光照和表情的问题.本文在多视角AAM的框架下,提出一种结合随机森林和线性判别分析(Linear discriminate analysis,LDA)的实时姿态估计算法对跟踪的人脸进行姿态预估计和更新,从而有效地解决了视频人脸大姿态变化的问题.提出了一种改进的在线表象模型(Online appearance model,OAM)方法来评估跟踪的准确性,并自适应地通过增量主成分分析(Principle component analysis,PCA)学习来更新AAM的纹理模型,极大地提高了跟踪的稳定性和模型应对光照和表情变化的能力.实验结果表明,本文算法在视频人脸特征点跟踪的准确性、鲁棒性和实时性方面都有良好的性能.%Facial feature tracking obtains precise information of facial components in addition to the coarse face position and moving track, and is important to computer vision. The active appearance model (AAM) is an efficient method to describe the facial features. However, it suffers from the sensitivity to initial parameters and may easily be stuck in local minima due to the gradient-descent optimization, which makes the AAM based tracker unstable in the presence of large pose, illumination and expression changes. In the framework of multi-view AAM, a real time pose estimation algorithm is proposed by combining random forest and linear discriminate analysis (LDA) to estimate and update the head pose during tracking. To improve the robustness to variations in illumination and expression, a modified online appearance model (OAM) is
Washburn, A.R.
1990-01-01
IEEE Transactions on Automatic Control, Vol. 35, 1990, pp. 852-855. This paper uses tracking time as an explicit objective in designing tracking algorithms that function in clutter. Implications of using "time to the first mistake" as a measure of tracking time are explored. An optimal tracker is derived for a special circukstance where there is clutter, but no measurement error, and is compared to a tracker based on the Maximum Likelihood principle.
Fast algorithm of computing volume based on convex hull%一种基于凸包近似的快速体积计算方法
Institute of Scientific and Technical Information of China (English)
徐志; 许宏丽
2013-01-01
体积是物体的基本几何属性，在许多应用场合需要频繁地被计算。目前基本上通过重构物体曲面而间接求取体积，增加了许多不必要的工作。提出一种快速求取点云模型体积的方法，使用增量式算法计算点云的凸包用来近似物体，将凸包分解成上下两个三角网格面，使用正投影法分别求取它们的投影体积，它们两者之差即是所求模型体积。实验表明该算法实现简单，可快速地求解处理具有任何几何和拓扑复杂性的点云模型。%Volume, as the basic geometric property of objects, needs to be calculated frequently in many applications. At present, volume is basically calculated through the reconstruction of object surface indirectly, increasing the number of unnecessary work. This paper presents a fast algorithm of computing volume based on convex hull. The method computes the convex hull of the point cloud by using incremental algorithm to approximate the 3D object, and then breaks the hull down into the high and lower triangular mesh surface. Both of the two shells’volume are calculated by the projection method and the difference between them is the object’s volume. This algorithm has been proven simple to implement and can process cloud models with arbitrary geometry and topology.
Institute of Scientific and Technical Information of China (English)
胡昭华; 鞠蓉; 欧阳雯; 金蓉
2016-01-01
In view of the problem that most discriminative algorithms for target tracking focus on the tracking speed while neglect the scale variation , a simple , robust discriminative algorithm based on color statistical characteristics was presented .The new color statistical characteristics not only possess the certain illumination invariance , but also maintain the higher discriminative power .An affine kinematics model for tracking was established to keep optimi-zing the parameters during tracking to solve the scale variation and the view angle change .To improve the tracking speed, the low-dimensional color statistical characteristics were used to describe the target appearance , and the color statistical characteristics were used to train naive Bayes classifiers and update classifiers online .The sample with the maximum confidence was regarded as the tracking result .Numerous comprehensive experiments were con-ducted for evaluation of the proposed algorithm and other algorithms , and the remarkable effectiveness under differ-ent challenge factors of the proposed tracking algorithm was showed .%针对目前目标跟踪的大部分判别算法注重跟踪效率而没有考虑尺度变化这一问题，提出了一个简单而鲁棒的基于颜色统计特征的判别跟踪方法。这种新的颜色统计特征具有一定的光照不变性，同时保持较强的判别能力。建立了跟踪过程的仿射运动模型，利用优化参数来解决尺寸及角度变化等问题。此外，为了进一步提高跟踪速度，采用低维的颜色统计特征描述目标外观，利用颜色统计特征训练贝叶斯分类器，将置信值最大的样本作为跟踪结果，并在线更新分类器。与现有跟踪器的大量综合性的对比实验表明，该判别跟踪方法在不同挑战因素下均有明显优势。
Suarez, Max J. (Editor); Chang, Alfred T. C.; Chiu, Long S.
1997-01-01
Seventeen months of rainfall data (August 1987-December 1988) from nine satellite rainfall algorithms (Adler, Chang, Kummerow, Prabhakara, Huffman, Spencer, Susskind, and Wu) were analyzed to examine the uncertainty of satellite-derived rainfall estimates. The variability among algorithms, measured as the standard deviation computed from the ensemble of algorithms, shows regions of high algorithm variability tend to coincide with regions of high rain rates. Histograms of pattern correlation (PC) between algorithms suggest a bimodal distribution, with separation at a PC-value of about 0.85. Applying this threshold as a criteria for similarity, our analyses show that algorithms using the same sensor or satellite input tend to be similar, suggesting the dominance of sampling errors in these satellite estimates.
1989-01-20
mflC FILE. OOR SA/TR-2/89 A003: FINAL REPORT COMPUTER ALGORITHMS AND ARCHITECTURES FOR THREE-DIMENSIONAL EDDY-CURRENT NONDESTRUCTIVE EVALUATION CD...J., Ullman, J., The Design and Analysis of Computer Algorithms , Addison-Wesley Publishing Company, 1974. [A2] Anderson, B., Moore, J., Optimal...actual data. DC- 17 I I I I [All Aho, A., Hopcroft, J., Ullman, J., The Design and Analysis of Computer Algorithms , Addison-Wesley Publishing Company
加速的 TLD 算法及其在多目标跟踪中的应用%Accelerated TLD Algorithm and its Application in Multiple Target Tracking
Institute of Scientific and Technical Information of China (English)
金哲; 刘传才
2016-01-01
Tracking-Learning-Detection (TLD) is a kind of long-term visual tracking algorithm which receiveds wide attention in recent years. In order to improve the running speed of this algorithm, a novel algorithm named Accelerated TLD (ATLD) is proposed in this paper. Two aspects of improvements were made in original TLD algorithm. The improvement includes as follows: using a grey prediction model in the detection module for estimating the location of the target and setting a detection area; applying an image indexing method based on normalized cross correlation (NCC) distance to manage the positive and negative sample set. And on this basis, the multiple targets tracking algorithm is realized. Through experiments, the ATLD algorithm, the original TLD algorithm and other two recent improved TLD algorithm are compared. The experimental results show that the ATLD algorithm runs faster on the premise of ensuring the accuracy.%TLD (Tracking-Learning-Detection)算法是近期受到广泛关注的一种长时间视觉跟踪算法。为提高该算法的运行速度，一种 ATLD (Accelerated TLD)算法被提出，对原始 TLD 算法做了两方面改进：在检测模块引入基于灰色预测模型的目标位置估计和检测区域设置；运用基于 NCC (Normalized Cross Correlation)距离的图像检索方法管理正负样本集。并在此基础上实现了多目标跟踪。通过实验比较了 ATLD 算法、原始 TLD 算法及两种近期改进的 TLD 算法。实验结果表明： ATLD 算法在确保精度的前提下运行速度更快。
Institute of Scientific and Technical Information of China (English)
谢文昌
2015-01-01
对信息源位置的隐私保护算法设计是保证网络用户通信安全基础,传统的隐私保护算法采用群签名跟踪算法,存储和搜索代价大,且具有可追踪的特点,保护性能不好.提出一种基于同态映射联合追踪的信息源位置隐私保护算法.以车用自组网络为例,进行信息源位置隐私保护系统初始化构建,在安全和隐私增强的情况下兼顾效率,采用批验证和撤销预处理减少验证和撤销检测的计算量,通过同态映射联合追踪,得到隐私保护的相对差异,调节平均偏差和方差,发送联合追踪请求,进行同态映射操作,提高隐私保护性能.仿真结果得出,算法具有较好的隐私保护性能,新算法在隐私保护水平和数据实用性方面较传统算法有明显改善.%The design of information source location privacy protection algorithm is to ensure the communication security based network users, privacy protection algorithm with traditional group signature tracking algorithm, storage and search cost, and has the characteristics of track, the protective performance is not good. Put forward a kind of location privacy pro-tection information source algorithm for joint tracking based on homomorphic mapping. In a vehicle ad hoc network as an example, carries on the information privacy protection system initialization position source construction, give consideration to efficiency in security and privacy enhancement cases, using batch verification and cancellation of pretreatment to reduce the verification and cancellation detection calculation, the homomorphic mapping combined with tracking, the relative dif-ference of privacy protection, adjust the average bias and variance send joint, track the request, homomorphic mapping op-erations, improve the privacy protection performance. Simulation results show this algorithm has a privacy protection, good performance, the new algorithm is compared with the traditional algorithm in the aspects of
Xu, Weina; Yu, Shupeng; Ma, Ying; Liu, Changping
2017-01-01
Background and purpose It is known that fluorine-18 fluorodeoxyglucose PET/computed tomography (CT) segmentation algorithms have an impact on the metabolic tumor volume (MTV). This leads to some uncertainties in PET/CT guidance of tumor radiotherapy. The aim of this study was to investigate the effect of segmentation algorithms on the PET/CT-based MTV and their correlations with the gross tumor volumes (GTVs) of cervical primary squamous cell carcinoma. Materials and methods Fifty-five patients with International Federation of Gynecology and Obstetrics stage Ia∼IIb and histologically proven cervical squamous cell carcinoma were enrolled. A fluorine-18 fluorodeoxyglucose PET/CT scan was performed before definitive surgery. GTV was measured on surgical specimens. MTVs were estimated on PET/CT scans using different segmentation algorithms, including a fixed percentage of the maximum standardized uptake value (20∼60% SUVmax) threshold and iterative adaptive algorithm. We divided all patients into four different groups according to the SUVmax within target volume. The comparisons of absolute values and percentage differences between MTVs by segmentation and GTV were performed in different SUVmax subgroups. The optimal threshold percentage was determined from MTV20%∼MTV60%, and was correlated with SUVmax. The correlation of MTViterative adaptive with GTV was also investigated. Results MTV50% and MTV60% were similar to GTV in the SUVmax up to 5 (P>0.05). MTV30%∼MTV60% were similar to GTV (P>0.05) in the 50.05) in the 100.05) in the SUVmax of at least 15 group. MTViterative adaptive was similar to GTV in both total and different SUVmax groups (P>0.05). Significant differences were observed among the fixed percentage method and the optimal threshold percentage was inversely correlated with SUVmax. The iterative adaptive segmentation algorithm led to the highest accuracy (6.66±50.83%). A significantly positive correlation was also observed between MTViterative
Christe, Andreas; Brönnimann, Alain; Vock, Peter
2014-02-01
A precise detection of volume change allows for better estimating the biological behavior of the lung nodules. Postprocessing tools with automated detection, segmentation, and volumetric analysis of lung nodules may expedite radiological processes and give additional confidence to the radiologists. To compare two different postprocessing software algorithms (LMS Lung, Median Technologies; LungCARE®, Siemens) in CT volumetric measurement and to analyze the effect of soft (B30) and hard reconstruction filter (B70) on automated volume measurement. Between January 2010 and April 2010, 45 patients with a total of 113 pulmonary nodules were included. The CT exam was performed on a 64-row multidetector CT scanner (Somatom Sensation, Siemens, Erlangen, Germany) with the following parameters: collimation, 24x1.2 mm; pitch, 1.15; voltage, 120 kVp; reference tube current-time, 100 mAs. Automated volumetric measurement of each lung nodule was performed with the two different postprocessing algorithms based on two reconstruction filters (B30 and B70). The average relative volume measurement difference (VME%) and the limits of agreement between two methods were used for comparison. At soft reconstruction filters the LMS system produced mean nodule volumes that were 34.1% (P filters (B30) was significantly larger than with hard filters (B70); 11.2% for LMS and 1.6% for LungCARE®, respectively (both with P filters, 13.6% for soft and 3.8% for hard filters, respectively (P 0.05). There is a substantial inter-software (LMS/LungCARE®) as well as intra-software variability (B30/B70) in lung nodule volume measurement; therefore, it is mandatory to use the same equipment with the same reconstruction filter for the follow-up of lung nodule volume.
1989-01-20
LLAA6 .l iI -SA/TR-2/89 A003: FINAL REPORT * COMPUTER ALGORITHMS AND ARCHITECTURES N FOR THREE-DIMENSIONAL EDDY-CURRENT NONDESTRUCTIVE EVALUATION...Ciasuication) COMPUTER ALGORITHMS AND ARCHITECTURES FOR THREE-DIMENSIONAL EDD~j~~JRRN iv ummary Q PERSONAL AUTriOR(S) SBAHASCAE 1 3a. TYPE Of REPORT
Adaptive Tracking Algorithm of Mobile Target Based on Neural Network%基于神经网络的机动目标自适应跟踪算法
Institute of Scientific and Technical Information of China (English)
范志明
2011-01-01
The tracking accuracy and the stability problem of immobile or weak mobile target have been trap to round people.This paper basis current statistics model of mobile target and the adaptive filtering algorithm of mean and variance.Constructived to put forward adaptive tracking algorithm of mobile target based on the neural network.Simulation experiments show it's effectiveness.%非机动或弱机动目标的跟踪精度和稳定性问题一直困绕着人们,根据机动目标"当前"统计模型和均值与方差自适应滤波算法,建设性提出了基于神经网络的机动目标自适应跟踪算法,并以仿真实验给予了验证.
Kovács, Attila; Oláh, Attila; Lux, Árpád; Mátyás, Csaba; Németh, Balázs Tamás; Kellermayer, Dalma; Ruppert, Mihály; Török, Marianna; Szabó, Lilla; Meltzer, Anna; Assabiny, Alexandra; Birtalan, Ede; Merkely, Béla; Radovits, Tamás
2015-04-01
Contractile function is considered to be precisely measurable only by invasive hemodynamics. We aimed to correlate strain values measured by speckle-tracking echocardiography (STE) with sensitive contractility parameters of pressure-volume (P-V) analysis in a rat model of exercise-induced left ventricular (LV) hypertrophy. LV hypertrophy was induced in rats by swim training and was compared with untrained controls. Echocardiography was performed using a 13-MHz linear transducer to obtain LV long- and short-axis recordings for STE analysis (GE EchoPAC). Global longitudinal (GLS) and circumferential strain (GCS) and longitudinal (LSr) and circumferential systolic strain rate (CSr) were measured. LV P-V analysis was performed using a pressure-conductance microcatheter, and load-independent contractility indices [slope of the end-systolic P-V relationship (ESPVR), preload recruitable stroke work (PRSW), and maximal dP/dt-end-diastolic volume relationship (dP/dtmax-EDV)] were calculated. Trained rats had increased LV mass index (trained vs. control; 2.76 ± 0.07 vs. 2.14 ± 0.05 g/kg, P rats (GLS: -18.8 ± 0.3 vs. -15.8 ± 0.4%; LSr: -5.0 ± 0.2 vs. -4.1 ± 0.1 Hz; GCS: -18.9 ± 0.8 vs. -14.9 ± 0.6%; CSr: -4.9 ± 0.2 vs. -3.8 ± 0.2 Hz, P rat model, strain and strain rate parameters closely reflected the improvement in intrinsic contractile function induced by exercise training.
Cassim, Naseem; Smith, Honora; Coetzee, Lindi M; Glencross, Deborah K
2017-01-01
CD4 testing in South Africa is based on an integrated tiered service delivery model that matches testing demand with capacity. The National Health Laboratory Service has predominantly implemented laboratory-based CD4 testing. Coverage gaps, over-/under-capacitation and optimal placement of point-of-care (POC) testing sites need investigation. We assessed the impact of relational algebraic capacitated location (RACL) algorithm outcomes on the allocation of laboratory and POC testing sites. The RACL algorithm was developed to allocate laboratories and POC sites to ensure coverage using a set coverage approach for a defined travel time (T). The algorithm was repeated for three scenarios (A: T = 4; B: T = 3; C: T = 2 hours). Drive times for a representative sample of health facility clusters were used to approximate T. Outcomes included allocation of testing sites, Euclidian distances and test volumes. Additional analysis included platform distribution and space requirement assessment. Scenarios were reported as fusion table maps. Scenario A would offer a fully-centralised approach with 15 CD4 laboratories without any POC testing. A significant increase in volumes would result in a four-fold increase at busier laboratories. CD4 laboratories would increase to 41 in scenario B and 61 in scenario C. POC testing would be offered at two sites in scenario B and 20 sites in scenario C. The RACL algorithm provides an objective methodology to address coverage gaps through the allocation of CD4 laboratories and POC sites for a given T. The algorithm outcomes need to be assessed in the context of local conditions.
Directory of Open Access Journals (Sweden)
Naseem Cassim
2017-02-01
Full Text Available Introduction: CD4 testing in South Africa is based on an integrated tiered service delivery model that matches testing demand with capacity. The National Health Laboratory Service has predominantly implemented laboratory-based CD4 testing. Coverage gaps, over-/under-capacitation and optimal placement of point-of-care (POC testing sites need investigation.Objectives: We assessed the impact of relational algebraic capacitated location (RACL algorithm outcomes on the allocation of laboratory and POC testing sites.Methods: The RACL algorithm was developed to allocate laboratories and POC sites to ensure coverage using a set coverage approach for a defined travel time (T. The algorithm was repeated for three scenarios (A: T = 4; B: T = 3; C: T = 2 hours. Drive times for a representative sample of health facility clusters were used to approximate T. Outcomes included allocation of testing sites, Euclidian distances and test volumes. Additional analysis included platform distribution and space requirement assessment. Scenarios were reported as fusion table maps.Results: Scenario A would offer a fully-centralised approach with 15 CD4 laboratories without any POC testing. A significant increase in volumes would result in a four-fold increase at busier laboratories. CD4 laboratories would increase to 41 in scenario B and 61 in scenario C. POC testing would be offered at two sites in scenario B and 20 sites in scenario C.Conclusion: The RACL algorithm provides an objective methodology to address coverage gaps through the allocation of CD4 laboratories and POC sites for a given T. The algorithm outcomes need to be assessed in the context of local conditions.
A New Algorithm for Tracking Sudden Maneuvering Target in Cluttered Environment%一种新型杂波环境下突发机动目标跟踪算法
Institute of Scientific and Technical Information of China (English)
戴路; 黄双华
2011-01-01
针对杂波环境下突发机动目标跟踪性能下降问题，提出了一种基于自适应匀加速模型的交互式自适应概率数据关联算法。该算法在交互式概率关联算法基础上，采用带渐消因子的自适应匀加速模型(ACA)与匀速模型(CV)相交互，克服了卡尔曼和扩展卡尔曼滤波的三大缺陷，保证了在突发机动下的良好跟踪性能，扩大了机动目标的跟踪范围，实现了杂波环境中对目标较高精度的状态估计。仿真结果验证了该算法相对于采用“当前”统计模型的交互式概率数据关联算法相比更有效。%To improve the tracking performance of a sudden maneuvering target in cluttered environment, a new interactive multiple models adaptive probability data association algorithm is presented based on a new adaptive constant acceleration model that adopts strong tracking filtering (IMM-ACAPDA) . The algorithm uses a adaptive constant acceleration model with a fading factor and a constant velocity model for interaction, avoids three disfigurements so the good tracking performance of sudden maneuvering targets can be ensured. It also extends the tracking range of maneuvering target, and the high precision of state estimation is ensured. The simulation results show that this algorithm is more effective than the IMM-PDA algorithm based on CS model.
Institute of Scientific and Technical Information of China (English)
文成林; 靳丽丽; 周颜芳
1999-01-01
Multiresolutional signal processing has been employed in image processing and computer vision to achieve improved performance that cannot be achieved using conventional signal processing techniques at only one resolution level[1,2,5,6]. In this paper,we have associated the thought of multiresolutional analysis with traditional Kalman filtering and proposed A new fusion algorithm based on singular Sensor and Multipale Models for maneuvering target tracking.
Institute of Scientific and Technical Information of China (English)
黄麟; 奚茂龙; 孙俊
2012-01-01
Decision-making rights are different according to the individuals' fitness values by the analysis of SI decision-making mechanism. The improvements of QPSO algorithm are proposed to improve searching efficiency and optimal performance by introducing linear weighted operator into algorithm. Sliding mode controller design method of robots trajectory tracking is analyzed. A new sliding mode control law is designed by combining index reaching law and power reaching law. The parameters in sliding mode tracking controller are optimized through PSO algorithm, QPSO algorithm and the improved QPSO algorithm. The design result of optimal tracking controller is validated by two design examples. It shows that tracking controller can control robot to track planned trajectory. Simulation results show that the improved QPSO algorithm can get better effect in optimizing parameters of controllers.%分析了智能群体的决策机制,发现在智能群体决策过程中,个体粒子参与决策的权利根据个体的优劣程度是不同的,提出了在量子粒子群优化(QPSO)算法中引入线性权重算子进一步提高QPSO算法的搜索效率及优化性能.分析了移动机器人轨迹跟踪控制的滑模变结构控制器设计方法,并采用指数趋近律和幂次趋近律相结合的方法,设计了新的滑模跟踪控制律,使用PSO算法、QPSO算法和改进算法优化了滑模跟踪控制器中的参数,通过两个实例验证了优化后的跟踪控制器的设计效果；设计效果的分析和比较表明了设计的跟踪控制器能够控制机器人实现对既定轨迹的跟踪,仿真结果显示改进QPSO算法能够在轨迹跟踪控制器的参数优化中取得更好的优化效果.
Institute of Scientific and Technical Information of China (English)
李悦; 冯新建; 宋庆雷; 秦洋
2015-01-01
This paper is focused on the multi‐orientation tracking of moving maritime target by the space moving three‐points TDOA location .A tracking algorithm based on KF (Kalman Filter) and a single/double TDOA tracking algorithm based on SR‐UKF (square root‐nonlinear Kalman filter) are given .The measure method of the initial anchor point and the initial covariance matrix w hich affect the filtering effect is also given .T he simulation re‐sults show that SR‐UKF tracking method is better under the TDOA data missing (single TDOA data) conditions .%研究了运动三站对海洋移动目标多次定位的跟踪滤波问题，给出基于卡尔曼滤波（KF）的定位点跟踪算法和基于平方根‐非线性卡尔曼滤波（SR‐UKF）的单／双时差跟踪算法，对于影响滤波效果的初始定位点和初始协方差阵，给出了计算方法，最后通过仿真验证了时差残缺（单时差）的观测条件下，SR‐UKF跟踪方法更优。
Institute of Scientific and Technical Information of China (English)
胡正平; 石巍; 谢荣路
2015-01-01
The meanshift tracking algorithm has been widely applied in visual tracking due to its well known merits such as the small amount of calculation and real⁃time.However when the scale orientation and illumination of target s changes and the color of the background is similar to the target the robustness of the traditional meanshift algorithm is poor and the accuracy of target location is not high as well as the algorithm stability is not good.For this reason an improved meanshift tracking method is proposed in the pa⁃per.In this algorithm a novel feature histogram is proposed which fuses the color and improved block LBP histograms as the repre⁃sentation of the tracked object it can extract the main information like the edge and the corner of the object.Besides with the help of moment information from the candidate object area it can solve the problem of the changes of the scale and direction of the tracked object during the tracking process. Compared with the traditional meanshift tracking algorithm and the combine feature algorithm which is changed before the proposed tracking algorithm achieves more stability and robustness in the complex condition.%经典meanshift跟踪算法因其具有计算量小、实时性强等优点而得到广泛应用。但在目标发生缩放、旋转、光照变化以及目标颜色与周围背景颜色难以区分等情况下，经典meanshift算法的鲁棒性不佳，目标定位精度不高，算法稳定性不好。鉴于此，本文提出一种联合颜色和纹理直方图表示的meanshift算法，其中本文用到的局部二值模式LBP是基于分块思想改进的纹理算子，有效地提取边缘和角点等主要目标模式来更加精炼地表示目标；另外，通过有效利用目标候选区域的矩信息，来解决跟踪目标运动中尺度和方向的变化的问题。通过不同场景视频跟踪实验表明，与经典meanshift算法及改进前的联合特征表示方法相比，文中提出的
Institute of Scientific and Technical Information of China (English)
周姗姗; 柴金广; 李丹
2011-01-01
针对探测系统跟踪误差对目标跟踪的影响,提出一种实时递推的最小二乘预测跟踪算法.该算法采用平方预测器的估算方式,获得目标运动轨迹的最佳逼近,通过不断更新的历史数据实时递推轨迹参数,预测下一帧目标位置.该算法采用Matlab软件编写易于工程实现的应用程序.得到仿真的目标真实轨迹与预测轨迹数据.仿真结果表明,该算法可以在系统延迟、目标机动的情况下实时快速地预测目标位置,降低跟踪误差.%To deal with the tracking error of observation system for target tracing, a novel predicted tracking algorithm which is based on least square principle in real-time recursively is presented. The algorithm chooses the square prediction as the estimation method to obtain the optimal approximation of the target motion trajectory. The algorithm updates recursive trajectory parameters based on the historical data in real-time, and then predicts the target position of next frame. The algorithm uses Matlab to program the application which is easy to realize for the practical project. According to an given example, the simulation of real trajectory and predicted trajectory are given. The simulation results show that the algorithm can predict the target position quickly and in real-time in the case of system delay or target maneuver, and reduce the tracking error.
基于H-K算法的MIDI文件主旋律音轨提取探讨%Exploration of MIDI Files Based on H-K Algorithm Extract Melody Tracks
Institute of Scientific and Technical Information of China (English)
马青阁; 曹西征; 赵宛; 汪旭彬; 关金晨
2016-01-01
主旋律是音乐旋律信息的重要组成部分，文章通过对表征音乐旋律特征向量的提取，采用H- K分类算法构建音轨分类器模型，对MIDI片旋律音轨和伴奏旋律音轨进行分类。最后通过候选音轨提取出主旋律音轨，研究表明，这种方法对10个音轨内的主旋律提取准确率由75%提升到90%，对于2个音轨以内的主旋律提取可以达到95%的准确率。%Theme is an important part of music melody information, based on the characterization of music melody feature vector extraction, the H-K audio classiifcation algorithm to construct classiifer model, MIDI audio piece of melody and accompaniment melody track for classiifcation. Finally through the candidate track extract melody track, research has shown that this approach within the 10 tracks on the main melody extraction accuracy increase from 75%to 75%, the two tracks of less than the main melody of extraction can reach 95%accuracy.
Institute of Scientific and Technical Information of China (English)
陈思; 苏松志; 李绍滋; 吕艳萍; 曹冬林
2014-01-01
The self-training based discriminative tracking methods use the classification results to update the classifier itself. However, these methods easily suffer from the drifting issue because the classification errors are accumulated during tracking. To overcome the disadvantages of self-training based tracking methods, a novel co-training tracking algorithm, termed Co-SemiBoost, is proposed based on online semi-supervised boosting. The proposed algorithm employs a new online co-training framework, where unlabeled samples are used to collaboratively train the classifiers respectively built on two feature views. Moreover, the pseudo-labels and weights of unlabeled samples are iteratively predicted by combining the decisions of a prior model and an online classifier. The proposed algorithm can effectively improve the discriminative ability of the classifier, and is robust to occlusions, illumination changes, etc. Thus the algorithm can better adapt to object appearance changes. Experimental results on several challenging video sequences show that the proposed algorithm achieves promising tracking performance.%基于自训练的判别式目标跟踪算法使用分类器的预测结果更新分类器自身，容易累积分类错误，从而导致漂移问题。为了克服自训练跟踪算法的不足，该文提出一种基于在线半监督boosting的协同训练目标跟踪算法(简称Co-SemiBoost)，其采用一种新的在线协同训练框架，利用未标记样本协同训练两个特征视图中的分类器，同时结合先验模型和在线分类器迭代预测未标记样本的类标记和权重。该算法能够有效提高分类器的判别能力，鲁棒地处理遮挡、光照变化等问题，从而较好地适应目标外观的变化。在若干个视频序列的实验结果表明，该算法具有良好的跟踪性能。
Institute of Scientific and Technical Information of China (English)
杨华; 陈善静; 曾凯; 张红
2012-01-01
针对跟踪目标尺度变化问题,提出了基于灰度对数似然图像分割的快速主动轮廓跟踪算法.改进的主动轮廓跟踪算法将根据以目标与背景的颜色差异而建立的对数似然图对图像进行阈值分割和数学形态学处理,再将Kalman滤波器结合到主动轮廓跟踪算法进行目标跟踪.改进的主动轮廓跟踪算法对目标分割准确,轮廓特征显著,跟踪效果稳定,算法能很好地适应跟踪目标尺度变化.通过Kalman滤波器对目标位置点的预测减少了主动轮廓跟踪算法收敛的迭代次数,使算法的运算效率提高了33％左右.%A fast active contour tracking(ACT) algorithm based on log-likelihood image segmentation has been proposed to solve the scale change problem in the process of target tracking. The algorithm adopts the log-likelihood image segmentation method, which segments images according to their log-likelihood images built based on the color difference between target and background, and the mathematical morphology method, and tracks the target with conventional ACT algorithm combined with Kalman filter. It tracks the target precisely with distinct contour features and stable tracking performance, and can well adapt to the target scale change. The Kalman filter adopted reduces the number of iterations for algorithm convergence through its forecast of the target position, and thus the fast ACT algorithm is about 33% more efficient than the conventional one.
Institute of Scientific and Technical Information of China (English)
季亚鹏; 孙万鹏
2013-01-01
为了解决在局部阴影的条件下，传统的最大功率点跟踪(MPPT)控制方法不能准确跟踪到最大功率点的问题，采用了粒子群优化算法，并通过粒子初始位置的设定、粒子群算法参数的设定和终止策略的制定提高了算法的准确性。通过添加粒子淘汰环节，提高了算法的执行效率。在 Matlab/Simulink 环境下进行了仿真，并且对仿真结果进行了分析，验证了该方法的正确性。%In order to solve the problem that under partially shaded conditions, the traditional maximum power point tracking (MPPT) control method can not correctly track the maximum point, this paper adopted the particle swarm optimization (PSO) algorithm and raised correctness of the algorithm via initial location of particles, setting of PSO algorithm parameters and making of termination strategy. Via adding of particles elimination link, execution efficiency of algorithm was raised. Simulation in Simulink of Matlab was carried out and the simulation result was analyzed to verify the correctness of the method.
3-D Phantom and In Vivo Cardiac Speckle Tracking Using a Matrix Array and Raw Echo Data
Byram, Brett C.; Holley, Greg; Giannantonio, Doug M.; Trahey, Gregg E.
2012-01-01
Cardiac motion has been tracked using various methods, which vary in their invasiveness and dimensionality. One such noninvasive modality for cardiac motion tracking is ultrasound. Three-dimensional ultrasound motion tracking has been demonstrated using detected data at low volume rates. However, the effects of volume rate, kernel size, and data type (raw and detected) have not been sufficiently explored. First comparisons are made within the stated variables for 3-D speckle tracking. Volumetric data were obtained in a raw, baseband format using a matrix array attached to a high parallel receive beam count scanner. The scanner was used to acquire phantom and human in vivo cardiac volumetric data at 1000-Hz volume rates. Motion was tracked using phase-sensitive normalized cross-correlation. Subsample estimation in the lateral and elevational dimensions used the grid-slopes algorithm. The effects of frame rate, kernel size, and data type on 3-D tracking are shown. In general, the results show improvement of motion estimates at volume rates up to 200 Hz, above which they become stable. However, peak and pixel hopping continue to decrease at volume rates higher than 200 Hz. The tracking method and data show, qualitatively, good temporal and spatial stability (for independent kernels) at high volume rates. PMID:20378447
Energy Technology Data Exchange (ETDEWEB)
Suzuki, Kenji; Kohlbrenner, Ryan; Epstein, Mark L.; Obajuluwa, Ademola M.; Xu Jianwu; Hori, Masatoshi [Department of Radiology, University of Chicago, 5841 South Maryland Avenue, Chicago, Illinois 60637 (United States)
2010-05-15
Purpose: Computerized liver extraction from hepatic CT images is challenging because the liver often abuts other organs of a similar density. The purpose of this study was to develop a computer-aided measurement of liver volumes in hepatic CT. Methods: The authors developed a computerized liver extraction scheme based on geodesic active contour segmentation coupled with level-set contour evolution. First, an anisotropic diffusion filter was applied to portal-venous-phase CT images for noise reduction while preserving the liver structure, followed by a scale-specific gradient magnitude filter to enhance the liver boundaries. Then, a nonlinear grayscale converter enhanced the contrast of the liver parenchyma. By using the liver-parenchyma-enhanced image as a speed function, a fast-marching level-set algorithm generated an initial contour that roughly estimated the liver shape. A geodesic active contour segmentation algorithm coupled with level-set contour evolution refined the initial contour to define the liver boundaries more precisely. The liver volume was then calculated using these refined boundaries. Hepatic CT scans of 15 prospective liver donors were obtained under a liver transplant protocol with a multidetector CT system. The liver volumes extracted by the computerized scheme were compared to those traced manually by a radiologist, used as ''gold standard.''Results: The mean liver volume obtained with our scheme was 1504 cc, whereas the mean gold standard manual volume was 1457 cc, resulting in a mean absolute difference of 105 cc (7.2%). The computer-estimated liver volumetrics agreed excellently with the gold-standard manual volumetrics (intraclass correlation coefficient was 0.95) with no statistically significant difference (F=0.77; p(F{<=}f)=0.32). The average accuracy, sensitivity, specificity, and percent volume error were 98.4%, 91.1%, 99.1%, and 7.2%, respectively. Computerized CT liver volumetry would require substantially less
A Volume Rendering Algorithm for Sequential 2D Medical Images%序列二维医学图象的体绘制法
Institute of Scientific and Technical Information of China (English)
吕忆松; 陈亚珠
2002-01-01
Volume rendering of 3D data sets composed of sequential 2D medical images has become an important branch in image processing and computer graphics. To help physicians fully understand deep-seated human organs and focuses (e. g. a tumnout) as 3D structures, in this paper, we present a modified volume rendering algorithm to render volumetric data. Using this method, the projection images of structures of interest from different viewing directions can be obtained satisfactorily. By rotating the light source and the observer eyepoint, this method avoids rotates the whole volumetric data in main memory and thus reduces computational complexity and rendering time. Experiments on CT images suggest that the proposed method is useful and efficient for rendering 3D data sets.
Institute of Scientific and Technical Information of China (English)
万智萍
2013-01-01
针对在弱光环境下的人体跟踪问题，本文提出一种带色素信息蚁群检测的弱光环境人体跟踪算法。通过利用蚁群优化算法检测监控帧图像里的物体边缘，并在初始帧图像里为聚集在边缘的蚁群身上标记色素信息，采用带色素的蚁群检测带信息素的蚁群并向其聚拢的性质来实现对处于弱光环境下的运动人体进行跟踪的目的。实验数据分析及仿真结果表明，本文的人体跟踪算法对处于弱光环境下的运动人体具有跟踪实效性，对存在噪声的图像也具有一定的鲁棒性。%As to the human body tracking problem under the weak light environment, human body tracking algorithm of ant colony detection with pigment information is presented. The character of ant colony optimization algorithm was used to detect the monitoring initial frame image object edge, and in the initial frame image to gather on the edge of the ant colony body, pigment information is marked. By using pigments ant colony detected with pheromone ant colony and toward pheromone ant colony gather, the purpose of tracking for human movement at night is achieved. The experimental data analysis and simulation results show that the human tracking algorithms for human movement under the low light environment is effective, and also has certain robustness for an image with noise.
SeaWiFS technical report series. Volume 4: An analysis of GAC sampling algorithms. A case study
Yeh, Eueng-Nan (Editor); Hooker, Stanford B. (Editor); Hooker, Stanford B. (Editor); Mccain, Charles R. (Editor); Fu, Gary (Editor)
1992-01-01
The Sea-viewing Wide Field-of-view Sensor (SeaWiFS) instrument will sample at approximately a 1 km resolution at nadir which will be broadcast for reception by realtime ground stations. However, the global data set will be comprised of coarser four kilometer data which will be recorded and broadcast to the SeaWiFS Project for processing. Several algorithms for degrading the one kilometer data to four kilometer data are examined using imagery from the Coastal Zone Color Scanner (CZCS) in an effort to determine which algorithm would best preserve the statistical characteristics of the derived products generated from the one kilometer data. Of the algorithms tested, subsampling based on a fixed pixel within a 4 x 4 pixel array is judged to yield the most consistent results when compared to the one kilometer data products.
Energy Technology Data Exchange (ETDEWEB)
BLUM,T.
1999-09-14
The RIKEN BNL Research Center hosted its 19th workshop April 27th through May 1, 1999. The topic was Numerical Algorithms at Non-Zero Chemical Potential. QCD at a non-zero chemical potential (non-zero density) poses a long-standing unsolved challenge for lattice gauge theory. Indeed, it is the primary unresolved issue in the fundamental formulation of lattice gauge theory. The chemical potential renders conventional lattice actions complex, practically excluding the usual Monte Carlo techniques which rely on a positive definite measure for the partition function. This ''sign'' problem appears in a wide range of physical systems, ranging from strongly coupled electronic systems to QCD. The lack of a viable numerical technique at non-zero density is particularly acute since new exotic ''color superconducting'' phases of quark matter have recently been predicted in model calculations. A first principles confirmation of the phase diagram is desirable since experimental verification is not expected soon. At the workshop several proposals for new algorithms were made: cluster algorithms, direct simulation of Grassman variables, and a bosonization of the fermion determinant. All generated considerable discussion and seem worthy of continued investigation. Several interesting results using conventional algorithms were also presented: condensates in four fermion models, SU(2) gauge theory in fundamental and adjoint representations, and lessons learned from strong; coupling, non-zero temperature and heavy quarks applied to non-zero density simulations.
Institute of Scientific and Technical Information of China (English)
牛曦晨; 熊家军; 李灵芝; 邱刚
2014-01-01
超视距雷达和红外预警卫星能对弹道导弹助推段进行探测跟踪，因此两者的情报可以相互关联印证，从而提高情报质量。针对超视距雷达和红外预警卫星的航迹关联问题，提出了一种基于小波变换的灰色关联度的航迹关联方法。该算法将超视距雷达和红外预警卫星的方位角信息序列通过小波变换进行去噪，得到方位角航迹的整体走势，然后对走势相同的方位角航迹建立灰色关联矩阵，并根据该矩阵按照一定的规则进行航迹相关判定。仿真结果表明，相对灰色关联度的关联算法，该算法的正确关联率提高了约8%。%Both the over-the-horizon radar and infrared early-warning satellite can detect and track the ballistic missile during the boost phase. Therefore, the intelligences out of them both can be correlated and confirmed mutually, thus improving the intelligence quality. Concerning for the track correlation of the over-the-horizon radar and infrared early-warning satellite, this paper proposes a method of track correlation using the grey correlation degree based on Wavelet transform. This proposed algorithm makes de-noising of the azimuth information sequence of the over-the-horizon radar and infrared early-warning satellite through Wavelet transform, obtains the overall trends of azimuth track, then sets up a grey correlation matrix for those azimuth track with the same trends, and finally, makes decision of track correlation according to a certain riles by this matrix. Simulation results show that the correct correlation rate using this algorithm can be improved approximately by 8%, with respect to the correlation algorithm with grey correlation degree.
1981-06-01
ACWWOWIEDGMENT (RPR) LIST > S".UCTUP RPALST GROUP acl TV- 0!?. < delivery status of maneuvers INT TD < ID of hCl > H: RE. < resolution advisory for ACI...smoothed 7 position estimate > SOUP times FLT AL!C" < time last ALIC entry generated > ?LT OWT < time last OWN message generated > ILT TD ( time ATARS...maintained for domino resolution > BIT DRSUP < AC track dropped by ATABS > BIT !?XLG < X/El-list indicator > BI I BWG < AC in antenna hub zone > BTT TNB’L
Institute of Scientific and Technical Information of China (English)
孙利娟; 南书坡; 杨新锋
2016-01-01
为降低遮挡对目标跟踪性能的影响，提出了一种基于自适应更新时空方向能量的目标跟踪算法。首先依据目标外观模型进行初步跟踪，计算目标平均运动矢量；然后，求取运动目标的时空方向能量特征，构建运动模型；依据运动模型和状态机检测目标状态，生成遮挡掩膜；最后，对不同状态和遮挡情况的目标采用不同的参数自适应更新其外观和运动模型。实验采用国际通用的CAVIAR和York两个公共测试数据集，并用平均跟踪误差和多目标跟踪精确度两个指标评测了跟踪性能。实验结果表明该方法的目标跟踪性能好，尤其是对目标遮挡的鲁棒性强。%To reduce the impact of occlusion on target tracking performance,a target tracking algorithm based on spatiotem⁃poral oriented⁃energy of adaptive update is proposed. With the algorithm,the moving target is tracked in preliminary according to its appearance model to compute the average motion vector,and then obtain the spatiotemporal oriented⁃energy feature of the target and construct the motion model. After that the target state is detected according to the motion model and state machine to generate the occlusion mask. For the target with different status and occlusion conditions,the appearance model and motion model of the target are self⁃adaptively updated by means of different parameters. In the experiment,two testing datasets(CAVIAR and York) commonly used in the world were adopted,and the indexes of average tracking error and multi⁃object tracking precision were employed to evaluate the tracking performance. The experimental results show that the proposed method has good target tracking performance,especially for strong robustness to target occlusion.
The Optimized Pedestrian Tracking-Learning-Detection Algorithm Based on SVM%基于支持向量机优化的行人跟踪学习检测方法∗
Institute of Scientific and Technical Information of China (English)
孙炜; 薛敏; 孙天宇; 胡梦云; 吕云峰
2016-01-01
A new method based on optimized TLD (Track-Learning-Detection)and SVM (Support Vector Machine)for tracking pedestrian was proposed.First,with pedestrians as positive samples and the background as negative samples respectively,HOG (Histogram of Oriented Gradient)descriptor of pedes-trian was extracted and combined with linear SVM to train the pedestrian classifier,which was used to ob-tain the calibrated pedestrian area accurately.Then,adaptive tracking and online learning on the pedestri-ans on the basis of TLD were integrated to estimate the reliability of the positive and negative samples,to rectify error existing in the current frame caused by detection and to update the tracking data simultaneous-ly to avoid subsequent similar mistakes.The experiment results demonstrate that,compared with the con-ventional tracking algorithm,the proposed algorithm can not only significantly adapt to occlusions and ap-pearance changes but also automatically identify and track pedestrian targets at arbitrary position,manifes-ting stronger robustness.%提出一种基于 SVM(Support Vector Machine)优化的 TLD(Track-Learning-Detection)行人检测跟踪算法。将行人作为正样本，背景作为负样本，提取出行人的 HOG特征并投入线性SVM中进行训练，得到行人检测分类器，并标定出目标区域，实现行人自动识别；然后在TLD算法的基础上对行人进行跟踪和在线学习，估计检测出的正负样本并实时修正检测器在当前帧中的误检，利用相邻帧间特征点配准剔除误配点，同时更新跟踪器数据，以避免后续出现类似错误。实验表明，该算法能够适应遮挡变化且自动识别并稳定跟踪目标行人，较传统跟踪算法具有更强的鲁棒性。
Institute of Scientific and Technical Information of China (English)
钮俊清; 单奇; 任清安; 刘军伟
2011-01-01
弹道导弹跟踪是弹道导弹防御系统中最核心的问题，然而传统的基于单运动模型的跟踪方法不能适用于跟踪弹道导弹的所有阶段。提出一种新的可变多模型(VUF)的跟踪方法，该方法具有以下的优势：采用多模型的结构，适用于跟踪任意阶段的弹道导弹;可变模型集的特征有效地提高了精度，同时降低了计算复杂度；采用UKF滤波方法具有更好的跟踪精度。仿真实验中设计了三个实验场景，与传统的EKF算法相比该方法明显地提高了跟踪的精度。特别是在弹道目标飞行阶段转换时，具有一定的识别能力和更鲁棒的跟踪性能。%In missile defense system, tracking ballistic target is the most key problem. However, the traditional method based on single-state model is not suitable for tracking ballistic target at all flight stages. The paper addresses a new tracking algorithm with variable-structure multiple model. It has several advantages. It is capable of tracking ballistic target at entire flight stages due to multiple model. Based on variable-structure, it improves tracking precision effectively and makes computational complexity lower. It has better tracking precision by using unscented Kalman filtering. Three simulation scenarios had been designed. Compared to the traditional EKF algorithm it has better estimation performance. Especially, it has some identification ability and more robust tracking performance during the switch phase of ballistic target.
Institute of Scientific and Technical Information of China (English)
文武; 姜涛
2015-01-01
由于传统M ean shif t跟踪算法固定了椭圆核的带宽和方向，对尺度和方向变化的目标跟踪定位不准或跟踪丢失。针对这一不足，提出一种尺度方向自适应的目标跟踪算法。首先用SIFT特征跟踪目标，并通过对SIFT特征点尺度和方向的实验分析，发现SIFT特征点的尺度变化和目标的尺度变化成正比、特征点主方向变化角度与目标旋转角度一致，提出目标尺度和方向的计算方法；其次引入相似性变换，利用带方向、可变带宽的椭圆核改进传统 Mean shift跟踪算法，使其能跟踪尺度和方向变化的目标。最后，融合SIFT特征跟踪结果和改进Mean shift的跟踪结果。实验表明：提出的算法能有效地跟踪具有尺度和方向变化的目标，获得的目标尺度、旋转方向参数精度较高，定位也更准确。%For the traditional Mean shift algorithm fixed bandwidth and direction of the ellipse kernel ,so the location of object tracking is inaccurate or lost .For this shortage , this thesis puts forward a kind of scale‐orientation adaptive object tracking algorithm .First of all ,tracked the object with the SIFT features .And then analysis of the SIFT feature’s scale and orientation ,found that the scale change of the SIFT feature point is proportional to that of the object ,the Angle change of the SIFT feature point is the same as that of the object ,puts forward the calculation method of object scale and orientation .Furthermore introduce the similarity transformation ,use variable‐bandwidth and orientation ellipse to improve the traditional Mean shift algorithm ,let it can track the object that scale and orientation changes .Finally ,the algorithm utilizes linear weighted method to fuse the tracking results of SIFT and improved Mean shift ,obtaining the final tracking results .Experiment shows that the proposed algorithm can effectively track the object that the scale and orientation change
Thomas, L.; Tremblais, B.; David, L.
2014-03-01
Optimization of multiplicative algebraic reconstruction technique (MART), simultaneous MART and block iterative MART reconstruction techniques was carried out on synthetic and experimental data. Different criteria were defined to improve the preprocessing of the initial images. Knowledge of how each reconstruction parameter influences the quality of particle volume reconstruction and computing time is the key in Tomo-PIV. These criteria were applied to a real case, a jet in cross flow, and were validated.
Institute of Scientific and Technical Information of China (English)
张永; 刘巧玲
2013-01-01
针对运用单一颜色特征描述运动目标时抗干扰性较差的问题,提出一种融合灰度共生矩阵和颜色特征的Mean-Shift目标跟踪算法.采用灰度共生矩阵推导的6个纹理特征参数和颜色特征分别表征跟踪目标,引入马氏距离计算纹理特征的相似度,并结合Bhattacharyya系数计算颜色特征的相似度,同时利用Mean Shift算法进行目标定位.实验表明,改进算法能在复杂背景下,有效、准确地实现目标跟踪.%Aimed at the problem that there is poor anti-jamming ability when the single color feature is used to describe the moving target,a target tracking algorithm was proposed based on Mean Shift which mixed gray level co-occurrence matrix (GLCM) and color feature together.Six parameters of texture deduced with GLCM and color feature parameters were used to characterize the tracking target.The similarity of texture feature was calculated by introducing Mahalanobis distance,and the Bhattacharyya coefficient was applied to calculate color feature similarity.Meantime,Mean Shift algorithm was used for target positioning.Experimental result showed that the improved algorithm could be used to track moving target effectively and accurately on a complex background.
Institute of Scientific and Technical Information of China (English)
陈鹏; 张慧
2012-01-01
In this paper a beam tracking algorithm based on satellite beacon signals is proposed and realized. The method is suitable for all kinds of phased array type mobile satellite communication antennas. It overcomes the difficulty of detecting the extremely weak satellite beacon signals and then the tracking performance is greatly improved. The highlight of the algorithm is the beam tracking process can be run without the help of gyroscopes and thus improves the survivability in the extreme environments. The algorithm was implemented and verified in a Ku band phased array mobile satellite antenna.%提出并实现了一种利用卫星信标信号来实施基于相控阵天线的波束跟踪算法。该方法适用于采用相控阵天线技术的各种卫星“动中通”天线，克服了卫星信标信号强度弱，检测困难的弱点，提高了跟踪信噪比，同时采用了软件无线电方式解调可以提供最大的灵活性。跟踪算法的最大优点是没有任何陀螺仪的辅助，极大地提高了天线在各种极端运动环境下的适应能力。算法最终在自行研制的Ku波段相控阵移动卫星天线系统上获得验证。
Track-stitching using graphical models and message passing
CSIR Research Space (South Africa)
Van der Merwe, LJ
2013-07-01
Full Text Available . Multiple crossing targets, with fragmented tracks, are simulated. It is then shown, that the algorithm successfully stitches track fragments together, even in the presence of false tracks, caused by noisy observations....
Peleg, Eran; Herblum, Ryan; Beek, Maarten; Joskowicz, Leo; Liebergall, Meir; Mosheiff, Rami; Whyne, Cari
2014-01-01
The reliability of patient-specific finite element (FE) modelling is dependent on the ability to provide repeatable analyses. Differences of inter-operator generated grids can produce variability in strain and stress readings at a desired location, which are magnified at the surface of the model as a result of the partial volume edge effects (PVEEs). In this study, a new approach is introduced based on an in-house developed algorithm which adjusts the location of the model's surface nodes to a consistent predefined threshold Hounsfield unit value. Three cadaveric human femora specimens were CT scanned, and surface models were created after a semi-automatic segmentation by three different experienced operators. A FE analysis was conducted for each model, with and without applying the surface-adjustment algorithm (a total of 18 models), implementing identical boundary conditions. Maximum principal strain and stress and spatial coordinates were probed at six equivalent surface nodes from the six generated models for each of the three specimens at locations commonly utilised for experimental strain guage measurement validation. A Wilcoxon signed-ranks test was conducted to determine inter-operator variability and the impact of the PVEE-adjustment algorithm. The average inter-operator difference in stress values was significantly reduced after applying the adjustment algorithm (before: 3.32 ± 4.35 MPa, after: 1.47 ± 1.77 MPa, p = 0.025). Strain values were found to be less sensitive to inter-operative variability (p = 0.286). In summary, the new approach as presented in this study may provide a means to improve the repeatability of subject-specific FE models of bone obtained from CT data.
Gavrielides, Marios A.; DeFilippo, Gino; Berman, Benjamin P.; Li, Qin; Petrick, Nicholas; Schultz, Kurt; Siegelman, Jenifer
2017-03-01
Computed tomography is primarily the modality of choice to assess stability of nonsolid pulmonary nodules (sometimes referred to as ground-glass opacity) for three or more years, with change in size being the primary factor to monitor. Since volume extracted from CT is being examined as a quantitative biomarker of lung nodule size, it is important to examine factors affecting the performance of volumetric CT for this task. More specifically, the effect of reconstruction algorithms and measurement method in the context of low-dose CT protocols has been an under-examined area of research. In this phantom study we assessed volumetric CT with two different measurement methods (model-based and segmentation-based) for nodules with radiodensities of both nonsolid (-800HU and -630HU) and solid (-10HU) nodules, sizes of 5mm and 10mm, and two different shapes (spherical and spiculated). Imaging protocols included CTDIvol typical of screening (1.7mGy) and sub-screening (0.6mGy) scans and different types of reconstruction algorithms across three scanners. Results showed that radio-density was the factor contributing most to overall error based on ANOVA. The choice of reconstruction algorithm or measurement method did not affect substantially the accuracy of measurements; however, measurement method affected repeatability with repeatability coefficients ranging from around 3-5% for the model-based estimator to around 20-30% across reconstruction algorithms for the segmentation-based method. The findings of the study can be valuable toward developing standardized protocols and performance claims for nonsolid nodules.
Zhang, Lihe; Lu, Huchuan; Du, Dandan; Liu, Luning
2016-02-01
In this paper, we propose a novel tracking framework based on a sparse and discriminative hashing method. Different from the previous work, we treat object tracking as an approximate nearest neighbor searching process in a binary space. Using the hash functions, the target templates and the candidates can be projected into the Hamming space, facilitating the distance calculation and tracking efficiency. First, we integrate both the inter-class and intra-class information to train multiple hash functions for better classification, while most classifiers in previous tracking methods usually neglect the inter-class correlation, which may cause the inaccuracy. Then, we introduce sparsity into the hash coefficient vectors for dynamic feature selection, which is crucial to select the discriminative and stable features to adapt to visual variations during the tracking process. Extensive experiments on various challenging sequences show that the proposed algorithm performs favorably against the state-of-the-art methods.
Institute of Scientific and Technical Information of China (English)
沈磊; 姜晨
2016-01-01
根据太阳能塔式发电定日镜高精度控制的需求，主要研究镜面偏心距对定日镜跟踪精度的影响，对其所造成的跟踪误差进行几何建模与仿真分析，研究结果表明镜面偏心距误差对追踪精度影响显著。为此提出一种实现镜面偏心距误差补偿的反射算法，利用实际定日镜实验装置的工作参数进行仿真计算与分析。分析结果表明该反射算法计算的姿态角误差小，计算量低，不仅能够很好地补偿镜面偏心距所造成的误差，而且特别适合植入嵌入式或者上位机控制平台，具有理想的应用前景。%In view of the requirements of high precision control in solar power tower heliostat, this paper presents an investigation on the influence of the mirror-pivot offset on the heliostat tracking error. The heliostat tracking error is geometrically modeled, by which the simulation analysis is conducted. The simulation results show that mirror-pivot offset has a significant effect on the tracking accuracy of heliostat. Therefore, a new reflection algorithm is de-veloped to compensate the mirror-pivot offset. Using the device parameters of actual experimental heliostat, the presented reflection algorithm is verified. The analysis results show that the reflection algorithm is effective to com-pensate the heliostat tracking angle errors. In view of the low calculation amount, it is a suitable reflection algo-rithm for embedded system and PC control platform.
Institute of Scientific and Technical Information of China (English)
刘翔; 侯志强; 余旺盛; 黄安奇
2015-01-01
This paper researched the problem that the traditional Mean-Shift algorithm could not track a size-changing object effectively,and proposed a new algorithm based on assistant decision-making of object similarity metric,to estimate the scale and orientation of a tracking window with adaptive bandwidth.Firstly,it adopted the saliency of object and background to im-prove tracking accuracy for orientation,and then employed the local exhaustive search to compute the similarity metric between object model and the certain region where was around the tracking center in each frame.Finally,it determined the object scale variation by similar pixel amounts.What’s more,it defined a novel bandwidth criterion for improving adaptability in tracking bandwidth.The experimental results prove that the present method can improve the tracking accuracy effectively in orientation between space and scale.%针对传统窗宽固定不变的Mean-Shift跟踪算法不能实时地适应目标尺寸大小变化这一问题，提出了一种基于目标相似度辅助决策的带宽自适应跟踪算法。首先利用目标与背景的特征显著性，提高跟踪算法空间定位准确性；然后利用局部穷搜索的方法，计算目标模型与每一帧目标跟踪中心点附近一定区域的相似性；最后通过统计分析前后帧相似像素点数目变化，确定目标尺度变化情况，从而建立一种自适应更新带宽准则，提高算法对目标尺度变化的自适应性。实验结果表明，改进的算法可以有效地提高Mean-Shift跟踪算法空间和尺度定位准确性。
Track Initiation for Electro-Optical Tracking of Space Objects
Xu, Z. W.; Wang, X.
2016-03-01
Aimed at the track initiation for the electro-optical tracking of space objects, and based on modified Hough transformation, a track initiation algorithm without prior information is proposed to realize the fully robotic identification and tracking of moving objects. The method is valid for the tracking of multi-target as well as with a non-continuous sequence. Simulation shows that the method is effective and applicable for operational usage, and is especially good for the search and discovery of new objects.
Energy Technology Data Exchange (ETDEWEB)
Wienke, B.R.; O' Dell, R.D.
1976-12-01
ESECT and EMAP are subroutines which provide a computer algorithm for mapping arbitrary meshes onto rectangular meshes in cylindrical (r,z) geometry. Input consists of the lines defining the rectangular mesh and the coordinates of the arbitrary mesh, which are assumed to be joined by straight lines. Output consists of the intersection volumes with designation of common mesh zones. The ESECT and EMAP routines do not comprise a ''free-standing'' code but, instead, are intended for inclusion in existing codes for which one mesh structure (typically Lagrangian) needs to be mapped onto an Eulerian mesh. Such mappings are of interest in coupled hydrodynamic and neutronic calculations. Exact expressions for the volumes of rotation (about z-axis) generated by the planar mesh intersection areas are used. Intersection points of the two meshes are computed and mapped onto corresponding regions on the rectangular mesh. Intersection points with the same regional indices are recorded into multilaterals, and the multilaterals are triangulated to facilitate computation of the intersection volumes. Dimension statements within ESECT/EMAP presently allow for rectangular and arbitrary meshes of 10k and 3.6k grid points. Scaling of all arrays to suit individual applications is easily effected. Computations of intersection volumes generated by overlapping 10k rectangular and 2.2k radial meshes require an average of 18 s computer time, while computation times for the same meshes scaled by a factor of /sup 1///sub 4/ in number of grid points average 3 s on the CDC 7600. Generally, cases of small cell rectangular meshes overlaid on large cell arbitrary meshes require the longer running times. 10 figures, 2 tables.
Institute of Scientific and Technical Information of China (English)
王建平; 赵高丽; 胡孟杰; 陈伟
2014-01-01
Multi-target tracking is a hot topic of current research on wireless sensor networks (WSN ). Based on adaptive sampling interval,we propose a multi-target tracking algorithm in order to save energy consumption and prevent tracking lost for WSN.We contrast the targets moving model by using the position metadata,and predicte the targets moving status based on extended Kalman filter (EKF).we adopt the probability density function (PDF )of the estimated targets to establish the tracking cluster.By defining the tracking center,we use Markov distance to quantify the election process of the main node (MN).We comput targets impact strength through the targets importance and the distance to MN node, and then use it to build tracking algorithm.We do the simulation experiment based on MATLAB,and the experiment results show that the proposed algorithm can accurate predict the trajectory of the targets,and adjust the sampling interval while the targets were moving.By analyzing the experiments data,we know that the proposed algorithm can improve the tracking precision and save the energy consumption of WSN obviously.%多目标跟踪是无线传感器网络当前研究的热点问题。针对多目标跟踪存在耗能较大，跟踪丢失等问题，提出了一种自适应采样间隔的多目标跟踪算法。采用跟踪目标的定位元数据来对目标的运动模式进行建模。基于扩展的卡尔曼滤波器来预测跟踪目标状态，采用预测目标定位的概率密度函数构建跟踪簇。通过定义跟踪目标中心，基于马氏距离来量化主节点 MN 的选举过程。通过跟踪目标重要性和其与MN之间的距离来量化目标的影响强度，并以此构建自适应采样间隔的多目标跟踪算法。基于MATLAB进行了仿真实验，实验结果显示，本文设计的跟踪算法能准确预测目标的运动轨迹，能随着运动目标的状态实时采用自适应的采样间隔。通过数据分析得知，本
Institute of Scientific and Technical Information of China (English)
孙志松; 程若发; 马银平
2012-01-01
研究太阳能电池提高光电转换率问题,由于光伏发电系统中最大功率点难以实时跟踪,使光伏阵列输出功率达不到要求.为此提出采用克隆选择算法进行优化控制.根据光伏电池等效电路模型在SIMULINK中建立仿真模型进行特性分析,并编写克隆选择算法.通过在算法进化过程中合理地选取种群规模、克隆规模和变异率等参数,从而保证算法以最佳的搜索轨迹达到最优解.通过对算法有效性的验证,仿真结果表明:在温度、光强变化情况下,能实时跟踪到最大功率点,提高系统的鲁棒性和发电效率.%The clonal selection algorithm (CSA) was proposed for maximum power point tracking for photovoltaic system to optimize and solve the difficult problem of real - time tracking. The simulation model was established by u-sing the equivalent circuit of photovoltaic cell in SIMULINK and running the CSA algorithm program in the m file under the MATLAB environment. By selecting the parameter reasonable population size, clonal size and mutation rate and so on in the process of evolutionary algorithm, the best search path was ensured to achieve the optimal solution. To verify the validity of the algorithm, an experiment was carried out and the result shows that, in case of variable temperature and light intensity, the algorithm can track the maximum power point in real -time, and improve the PV system's robustness and power efficiency.
光伏并网逆变器最大功率点跟踪算法的研究%Research on the photovolatic inverter maximum power point tracking algorithm
Institute of Scientific and Technical Information of China (English)
张一驰; 王紫婷; 王勉
2012-01-01
Grid-connected PV systems is the development trend of photovoltaic power generation system,the maximum power point tracking technology is to improve the photovoltaic efficiency.In this parper,analysis and research on the basis of the three maximum power point tracking commonly used method advantages and disadvantages of an integrated optimization method.Solar photovoltaic conversion system,through specific experiments the larger step of the perturbation and observation method,constant voltage and admittance incremental method,the optimization method proposed in this paper,through simulation of the improved algorithm,as well as comparison with other algorithms,indicating the correctness of this improved algorithm to verify the feasibility and superiority of this algorithm.%光伏并网发电系统是光伏发电系统的发展趋势,而最大功率点跟踪技术是提高光伏发电效率的主要技术。本文在分析和研究了3种常用最大功率点跟踪方法优缺点的基础上,提出了一种集这3种常用方法优点的新方法,即综合优化法。在太阳能光伏转换系统中,通过具体实验比较了较大步长的扰动观察法,恒电压法和导纳增量法,还有本文中提出的综合优化法,通过对改进算法的仿真,以及与其他算法的比较,说明了这种改进算法的正确性,验证了这种算法的可行性及优越性。
TPC track distortions IV: post tenebras lux
Ammosov, V; Boyko, I; Chelkov, G; Dedovitch, D; Dydak, F; Elagin, A; Gostkin, M; Guskov, A; Koreshev, V; Krumshtein, Z; Nefedov, Y; Nikolaev, K; Wotschack, J; Zhemchugov, A
2007-01-01
We present a comprehensive discussion and summary of static and dynamic track distortions in the HARP TPC in terms of physical origin, mathematical modelling and correction algorithms. `Static' distortions are constant with time, while `dynamic' distortions are distortions that occur only during the 400 ms long accelerator spill. The measurement of dynamic distortions, their mathematical modelling and the correction algorithms build on our understanding of static distortions. In the co