Thèses sur le sujet « TRACKED TARGET »
Pour voir les autres types de publications sur ce sujet consultez le lien suivant : TRACKED TARGET.
Créez une référence correcte selon les styles APA, MLA, Chicago, Harvard et plusieurs autres
Consultez les 50 meilleures thèses pour votre recherche sur le sujet « TRACKED TARGET ».
À côté de chaque source dans la liste de références il y a un bouton « Ajouter à la bibliographie ». Cliquez sur ce bouton, et nous générerons automatiquement la référence bibliographique pour la source choisie selon votre style de citation préféré : APA, MLA, Harvard, Vancouver, Chicago, etc.
Vous pouvez aussi télécharger le texte intégral de la publication scolaire au format pdf et consulter son résumé en ligne lorsque ces informations sont inclues dans les métadonnées.
Parcourez les thèses sur diverses disciplines et organisez correctement votre bibliographie.
1
Canay, Mustafa. « Use Of Terrain Information To Improve The Performance Of A Target Tracker ». Master's thesis, METU, 2009. http://etd.lib.metu.edu.tr/upload/12610716/index.pdf.
Texte intégralRésumé :
Radar target tracking problem has been a popular topic for several decades. Recent works have shown that the performance of tracking algorithms increases as more prior information is used by the systemsuch as maximum velocity and maximum acceleration of the target, altitude of the target, or the elevation structure of the terrain. In this thesis we will focus on increasing the performance of tracking algorithms making use of benefit from the elevation model of the environment where the target tracker is searching. For a constant target altitude and a certain radar location, we generate a &ldquo
visibility map&rdquo
using the elevation model of the terrain and use this information to estimate the location and the time that the target will reappear. The second aim of this work is to use the visibility map information for improving the performance of track initiation. For that purpose, a special map has been formed, that we call as the &ldquo
track initiation probability map&rdquo
, which shows the target first time appearance density. This information has been used at the initialization part of the track initiation algorithm in order to increase the performance.
2
Preussner, Jonathan J. « Multiple target tracker and human classifier for radar application ». [Gainesville, Fla.] : University of Florida, 2005. http://purl.fcla.edu/fcla/etd/UFE0009821.
Texte intégral
3
Laird, Daniel T. « Geometric Model for Tracker-Target Look Angles and Line of Sight Distance ». International Foundation for Telemetering, 2015. http://hdl.handle.net/10150/596399.
Texte intégralRésumé :
ITC/USA 2015 Conference Proceedings / The Fifty-First Annual International Telemetering Conference and Technical Exhibition / October 26-29, 2015 / Bally's Hotel & Convention Center, Las Vegas, NVTo determine the tracking abilities of a Telemetry (TM) antenna control unit (ACU) requires 'truth data' to analyze the accuracy of measured, or observed tracking angles. This requires we know the actual angle, i.e., that we know where the target is above the earth. The positional truth is generated from target time-space position information (TSPI), which implicitly places the target's global positioning system (GPS) as the source of observational accuracy. In this paper we present a model to generate local look-angles (LA) and line-of-sight (LoS) distance with respect to (w.r.t.) target global GPS. We ignore inertial navigation system (INS) data in generating relative position at time T; thus we model the target as a global point in time relative to the local tracker's global fixed position in time. This is the first of three companion papers on tracking This is the first of three companion papers on tracking analyses employing Statistically Defensible Test & Evaluation (SDT&E) methods.
4
Biresaw, Tewodros Atanaw. « Self-correcting Bayesian target tracking ». Thesis, Queen Mary, University of London, 2015. http://qmro.qmul.ac.uk/xmlui/handle/123456789/7925.
Texte intégralRésumé :
Visual tracking, a building block for many applications, has challenges such as occlusions,illumination changes, background clutter and variable motion dynamics that may degrade the tracking performance and are likely to cause failures. In this thesis, we propose Track-Evaluate-Correct framework (self-correlation) for existing trackers in order to achieve a robust tracking. For a tracker in the framework, we embed an evaluation block to check the status of tracking quality and a correction block to avoid upcoming failures or to recover from failures. We present a generic representation and formulation of the self-correcting tracking for Bayesian trackers using a Dynamic Bayesian Network (DBN). The self-correcting tracking is done similarly to a selfaware system where parameters are tuned in the model or different models are fused or selected in a piece-wise way in order to deal with tracking challenges and failures. In the DBN model representation, the parameter tuning, fusion and model selection are done based on evaluation and correction variables that correspond to the evaluation and correction, respectively. The inferences of variables in the DBN model are used to explain the operation of self-correcting tracking. The specific contributions under the generic self-correcting framework are correlation-based selfcorrecting tracking for an extended object with model points and tracker-level fusion as described below. For improving the probabilistic tracking of extended object with a set of model points, we use Track-Evaluate-Correct framework in order to achieve self-correcting tracking. The framework combines the tracker with an on-line performance measure and a correction technique. We correlate model point trajectories to improve on-line the accuracy of a failed or an uncertain tracker. A model point tracker gets assistance from neighbouring trackers whenever degradation in its performance is detected using the on-line performance measure. The correction of the model point state is based on the correlation information from the states of other trackers. Partial Least Square regression is used to model the correlation of point tracker states from short windowed trajectories adaptively. Experimental results on data obtained from optical motion capture systems show the improvement in tracking performance of the proposed framework compared to the baseline tracker and other state-of-the-art trackers. The proposed framework allows appropriate re-initialisation of local trackers to recover from failures that are caused by clutter and missed detections in the motion capture data. Finally, we propose a tracker-level fusion framework to obtain self-correcting tracking. The fusion framework combines trackers addressing different tracking challenges to improve the overall performance. As a novelty of the proposed framework, we include an online performance measure to identify the track quality level of each tracker to guide the fusion. The trackers in the framework assist each other based on appropriate mixing of the prior states. Moreover, the track quality level is used to update the target appearance model. We demonstrate the framework with two Bayesian trackers on video sequences with various challenges and show its robustness compared to the independent use of the trackers used in the framework, and also compared to other state-of-the-art trackers. The appropriate online performance measure based appearance model update and prior mixing on trackers allows the proposed framework to deal with tracking challenges.
5
Sakamaki, Joshua Y. « Cooperative Estimation for a Vision-Based Multiple Target Tracking System ». BYU ScholarsArchive, 2016. https://scholarsarchive.byu.edu/etd/6072.
Texte intégralRésumé :
In this thesis, the Recursive-Random Sample Consensus (R-RANSAC) algorithm is applied to a vision-based, cooperative target tracking system. Unlike previous applications, which focused on a single camera platform tracking targets in the image frame, this work uses multiple camera platforms to track targets in the inertial or world frame. The process of tracking targets in the inertial frame is commonly referred to as geolocation.In practical applications sensor biases cause the geolocated target estimates to be biased from truth. The method for cooperative estimation developed in this thesis first estimates the relative rotational and translational biases that exist between tracks from different vehicles. It then accounts for the biases and performs the track-to-track association, which determines if the tracks originate from the same target. The track-to-track association is based on a sliding window approach that accounts for the correlation between tracks sharing common process noise and the correlation in time between individual estimation errors, yielding a chi-squared distribution. Typically, accounting for the correlation in time requires the inversion of a Nnx x Nnx covariance matrix, where N is the length of the window and nx is the number of states. Note that this inversion must occur every time the track-to-track association is to be performed. However, it is shown that by making a steady-state assumption, the inverse has a simple closed-form solution, requiring the inversion of only two nx x nx matrices, and can be calculated offline. Distributed data fusion is performed on tracks where the hypothesis test is satisfied. The proposed method is demonstrated on data collected from an actual vision-based tracking system.A novel method is also developed to cooperatively estimate the location and size of occlusions. This capability is important for future target tracking research involving optimized path planning/gimbal pointing, where a geographical map is unavailable. The method is demonstrated in simulation.
6
Palkki, Ryan D. « Addressing Track Coalescence in Sequential K-Best Multiple Hypothesis Tracking ». Thesis, Georgia Institute of Technology, 2006. http://hdl.handle.net/1853/11493.
Texte intégralRésumé :
Multiple Hypothesis Tracking (MHT) is generally the preferred data association technique for tracking targets in clutter and with missed detections due to its increased accuracy over conventional single-scan techniques such as Nearest Neighbor (NN) and Probabilistic Data Association (PDA). However, this improved accuracy comes at the price of greater complexity. Sequential K-best MHT is a simple implementation of MHT that attempts to achieve the accuracy of multiple hypothesis tracking with some of the simplicity of single-frame methods.
Our first major objective is to determine under
what general conditions Sequential K-best data association is preferable to Probabilistic Data Association. Both methods are implemented for a single-target, single-sensor scenario in two spatial dimensions. Using the track loss ratio as our primary performance metric, we compare the two methods under varying false alarm densities and missed-detection probabilities.
Upon implementing a single-target Sequential K-best MHT tracker, a fundamental problem was observed in which the tracks coalesce. The second major thrust of this research is to compare different approaches to resolve this issue. Several methods to detect track coalescence, mostly based on the Mahalanobis and Kullback-Leibler distances, are presented and compared.
7
Nasr, Talia S. « Identification of Hedgehog/Gli Targets during Tracheoesophageal Development ». University of Cincinnati / OhioLINK, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1593273349807685.
Texte intégral
8
Santos, Susana Isabel Barros dos. « Trace elements quantification in Portuguese red wines ». Master's thesis, Faculdade de Ciências e Tecnologia, 2011. http://hdl.handle.net/10362/6276.
Texte intégralRésumé :
Dissertation for the Degree of Master in
Technology and Food Safety – Food QualityThe aim of this thesis is to characterize Portuguese red wines in terms of trace elements composition. The wines were chosen so that all the country was represented and studied. For trace elements quantification (As, Hg, Cd, Ni and Pb) were tested various sample treatments including for all trace elements: acid digestion or presence and absence of spike. The need for H2O2 addition in order to oxidize organic compounds was analyzed for Hg, Cd, Ni and Pb. Quantification of all trace elements was performed with Atomic Absorption Spectrometry techniques. After the method validation were analyzed 25 Portuguese red wines and duplicates. The concentrations obtained were used to perform a statistical analysis to determine what were the regions with highest incidence of each trace element. Using Target Hazard Quotient (THQ) equation was possible to identify the regions where the concentrations found are a reason for public health concern, being values above 1 a motive for concern. After the analysis was determined that there is no need for wine samples digestion and that the presence of H2O2 is crucial. Hg and As were quantified with Hydride Generation Atomic Absorption Spectrometry; Ni and Pb with Flame Atomic Absorption Spectrometry; Cd with Electrothermal Atomic Absorption Spectrometry. The statistical results allowed to conclude that the system variation was mainly explained by the variation of Ni, As and Hg concentrations. Ni was largely found in Estremadura and Terras do Sado wines, while As and Hg were found mostly in Minho and Douro wines respectively. All of THQs determined were under 1, which is the limit value above which there is reason for health concern. Maximum THQ values were of 0.044 in Algarve wines were due to Ni.
9
Cotter, Rachel. « Trace amine associated receptors : a new target for medications in drug addiction ». Thesis, University of Canterbury. Psychology, 2012. http://hdl.handle.net/10092/10803.
Texte intégralRésumé :
The abuse of stimulant drugs, such as methamphetamine (METH), has become a major source of public concern in New Zealand. Specific medications for treating METH addiction are not available at present. The newly discovered trace amine- associated receptor 1 (TAAR1) constitutes a novel receptor target for medication development in neuropsychiatry. TAAR1 regulates monoamine systems in the brain, especially dopamine, and is activated directly by psychomotor stimulants, including METH. This study examined the effects of the newly developed TAAR1 partial agonist, RO5203648, in rat models of METH abuse. In experiment 1 rats were administered different doses of RO5203648 (0, 1.67, 5mg/kg i.p.) followed by METH (0, 0.75, 2mg/kg i.p.). Locomotor activity was monitored via automated video tracking system in an open field. The results revealed that RO5203648 dose- dependently reduced acute METH-induced stimulation and prevented long-term sensitization following chronic exposure. Paradoxically, in experiment 2, RO5203648 and METH treatment increased c-Fos protein expression in the nucleus accumbens and dorsal striatum. In experiment 3 rats were trained to consistently self-administer METH (0.5mg/kg/infusion) and were then pre-treated with RO5203648 (0, 3, 10mg/kg i.p.). The data showed that RO5203648 drastically reduced METH intake. Next, RO5203648 was substituted (0.25, 0.5, 1.0 mg/kg/infusion) for METH in the same paradigm. Remarkably, RO5203648 exhibited no reinforcing efficacy compared with METH. Taken together, these observations showed that RO5203648 is able to attenuate METH-related behaviours, including locomotor stimulation, sensitization and self-administration, and highlight the great potential of TAAR1-based medications for the treatment of METH addiction.
10
Tang, Zhijun. « Information-theoretic management of mobile sensor agents ». Connect to resource, 2005. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1126882086.
Texte intégralRésumé :
Thesis (Ph. D.)--Ohio State University, 2005.Title from first page of PDF file. Document formatted into pages; contains xiii, 170 p.; also includes graphics (some col.). Includes bibliographical references (p. 162-170). Available online via OhioLINK's ETD Center
11
Pawlak, Robert James. « Multisensor track initiation method that addresses the missing measurement problem ». Diss., Virginia Tech, 1992. http://hdl.handle.net/10919/38631.
Texte intégral
12
Kusomoto, André Yoshimi, Vasconcelos Luis Edwardo Guarino de, Nelson Paiva Oliveira Leite, Cristina Monis Araújo Lopes et Rogério Pirk. « Tracking Track Targets in External Store Separation Using Computer Vision ». International Foundation for Telemetering, 2014. http://hdl.handle.net/10150/577476.
Texte intégralRésumé :
ITC/USA 2014 Conference Proceedings / The Fiftieth Annual International Telemetering Conference and Technical Exhibition / October 20-23, 2014 / Town and Country Resort & Convention Center, San Diego, CAFlight tests and flight safety are tightly coupled. For a given experimental test flight, the main objective to be achieved is related to the test bed and crew integrity (i.e. Bring back the test bed in one piece). Furthermore, the aircraft operational safety (i.e. continued airworthiness) relies into the accuracy of gathered information, provided by the airborne Flight Test Instrumentation (FTI) system. Typically, the FTI system includes: a data acquisition system; a transmission system; a data recorder; multiple sensors and auxiliary equipment such as Global Navigation Satellite System (GNSS) Receiver. In a specific Flight Test Campaign (FTC), such as external stores separation FTC, the associated risk is high because the non-linear and unpredicted aerodynamics couplings between the released store and the aircraft structure (e.g. wings) could lead to a catastrophic collision condition. Typically, the setup for such FTC is a big technical challenge for the instrumentation group because the determination of six degrees of freedom (6Dof) trajectory of the release store becomes mandatory. Such information could be by the means of an optical tracking system that requires the integration of two or more hi-speed hi-resolution video cameras into FTI. Unfortunately, the FTI and the Real-Time Telemetry Link (RTL) limited bandwidth imposes several restrictions for the development and implementation of a real-time application to be used at the Ground Telemetry System (GTS) for the verification of the separation safety and the validation of the test point. This paper, presents the implementation of computer vision techniques and Camshift algorithm as an approach to tracking individual track targets on the store surface which can be perform onboard and in real time or near real time. The development of the algorithm is presented as well several experimental test results that use videos frames gathered from previous FTC executed by Instituto de Pesquisas e Ensaios em Voo (Flight Test and Research Institute - IPEV). Preliminary results present satisfactory performance.
13
Powers, Richard. « Track-loss detection in the absence of truth data for target tracking in clutter ». Connect to online resource, 2007. http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&res_dat=xri:pqdiss&rft_dat=xri:pqdiss:3273736.
Texte intégral
14
Torstensson, Johan, et Mikael Trieb. « Particle Filtering for Track Before Detect Applications ». Thesis, Linköping University, Department of Electrical Engineering, 2005. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-4046.
Texte intégralRésumé :
Integrated tracking and detection, based on unthresholded measurements, also referred to as track before detect (TBD) is a hard nonlinear and non-Gaussian dynamical estimation and detection problem. However, it is a technique that enables the user to track and detect targets that would be extremely hard to track and detect, if possible at all with ''classical'' methods. TBD enables us to be better able to detect and track weak, stealthy or dim targets in noise and clutter and particles filter have shown to be very useful in the implementation of TBD algorithms.
This Master's thesis has investigated the use of particle filters on radar measurements, in a TBD approach.
The work has been divided into two major problems, a time efficient implementation and new functional features, as estimating the radar cross section (RCS) and the extension of the target. The later is of great importance when the resolution of the radar is such, that specific features of the target can be distinguished. Results will be illustrated by means of realistic examples.
15
Guner, Onur. « Evaluation Of Multi Target Tracking Algorithms In The Presence Of Clutter ». Master's thesis, METU, 2005. http://etd.lib.metu.edu.tr/upload/2/12606406/index.pdf.
Texte intégralRésumé :
ABSTRACT
EVALUATION OF MULTI TARGET TRACKING ALGORITHMS
IN THE PRESENCE OF CLUTTER
Güner, Onur M.S., Department of Electrical and Electronics Engineering Supervisor: Prof. Dr. Mustafa Kuzuoglu August 2005, 88 Pages This thesis describes the theoretical bases, implementation and testing of a multi target tracking approach in radar applications. The main concern in this thesis is the evaluation of the performance of tracking algorithms in the presence of false alarms due to clutter. Multi target tracking algorithms are composed of three main parts: track initiation, data association and estimation. Two methods are proposed for track initiation in this work. First one is the track score function followed by a threshold comparison and the second one is the 2/2 &
M/N method which is based on the number of detections. For data association problem, several algorithms are developed according to the environment and number of tracks that are of interest. The simplest method for data association is the nearest-neighbor data association technique. In addition, the methods that use multiple hypotheses like probabilistic data association and joint probabilistic data association are introduced and investigated. Moreover, in the observation to track assignment, gating is an important issue since it reduces the complexity of the computations. Generally, ellipsoidal gates are used for this purpose. For estimation, Kalman filters are used for state prediction and measurement update. In filtering, target kinematics is an important point for the modeling. Therefore, Kalman filters based on different target kinematic models are run in parallel and the outputs of filters are combined to yield a single solution. This method is developed for maneuvering targets and is called interactive multiple modeling (IMM). All these algorithms are integrated to form a multi target tracker that works in the presence (or absence) of clutter. Track score function, joint probabilistic data association (JPDAF) and interactive multiple model filtering are used for this purpose. Keywords: clutter, false alarms, track initiation, data association, gating, target kinematics, IMM, JPDAF
16
Losie, Philip M. « Detection and Tracking of Stealthy Targets Using Particle Filters ». DigitalCommons@CalPoly, 2009. https://digitalcommons.calpoly.edu/theses/227.
Texte intégralRésumé :
In recent years, the particle filter has gained prominence in the area of target tracking because it is robust to non-linear target motion and non-Gaussian additive noise. Traditional track filters, such as the Kalman filter, have been well studied for linear tracking applications, but perform poorly for non-linear applications. The particle filter has been shown to perform well in non-linear applications. The particle filter method is computationally intensive and advances in processor speed and computational power have allowed this method to be implemented in real-time tracking applications. This thesis explores the use of particle filters to detect and track stealthy targets in noisy imagery. Simulated point targets are applied to noisy image data to create an image sequence. A particle filter method known as Track-Before-Detect is developed and used to provide detection and position tracking estimates of a single target as it moves in the image sequence. This method is then extended to track multiple moving targets. The method is analyzed to determine its performance for targets of varying signal-to-noise ratio and for varying particle set sizes.
The simulation results show that the Track-Before-Detect method offers a reliable solution for tracking stealthy targets in noisy imagery. The analysis shows that the proper selection of particle set size and algorithm improvements will yield a filter that can track targets in low signal-to-noise environments. The multi-target simulation results show that the method can be extended successfully to multi-target tracking applications.
This thesis is a continuation of automatic target recognition and target tracking research at Cal Poly under Dr. John Saghri and is sponsored by Raytheon Space and Airborne Systems.
17
Sabuncu, Murat. « Particle Filter Based Track Before Detect Algorithm For Tracking Of Dim Moving Targets ». Master's thesis, METU, 2012. http://etd.lib.metu.edu.tr/upload/12614155/index.pdf.
Texte intégralRésumé :
In this study Track Before Detect (TBD) approach will be analysed for tracking of dim moving
targets. First, a radar setup is presented in order to introduce the radar range equation and
signal models. Then, preliminary information is given about particle filters. As the main
algorithm of this thesis, a multi-model particle filter method is developed in order to solve
the non-linear non-Gaussian Bayesian estimation problem. Probability of target existence
and RMS estimation accuracy are defined as the performance parameters of the algorithm for
very low SNR targets. Simulation results are provided and performance analysis is presented
as a conclusion.
18
Ljung, Johnny. « Track Before Detect in Active Sonar Systems ». Thesis, Uppsala universitet, Signaler och system, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-447314.
Texte intégralRésumé :
Detection of an underwater target with active sonar in shallow waters such as the Baltic sea is a big challenge. This since the sound beams from the sonar will be reflected on the surfaces, sea surface and sea bottom, and the water volume itself which generates reverberation. Reverberation which will be reflected back to the receiver, is strong in intensity which give rise to many false targets in terms of classifying a target in a surveillance area. These false targets are unwanted and a real target might benefit from these miss-classifications in terms of remaining undetected. It is especially hard if the signal-to-noise ratio (SNR) is approaching zero, i.e. the target strength and the reverberation strength are equal in magnitude. The classical approach to a target detection problem is to assign a threshold value to the measurement, and the data point exceeding the threshold is classified as a target. This approach does not hold for low levels of SNR, since a threshold would not have a statistical significance and could lead to neglecting important data. Track-before-detect (TrBD) is a proposed method for low-SNR situations which tracks and detects a target based on unthresholded data. TrBD enables tracking and detecting of weak and/or stealthy targets. Due to the issues with target detection in shallow waters, the hypothesis of this thesis is to investigate the possibility to implement TrBD, and evaluate the performance of it, when applied on a low-SNR target. The TrBD is implemented with a particle filter which is a recursive Bayesian solution to the problem of integrated tracking and detection. The reverberation data was generated by filtering white noise with an Autoregressive filter of order 1. The target is assigned to propagate according to a constant velocity state space model. Two types of TrBD algorithms are implemented, one which is trained on the background and one which is not. The untrained TrBD is able to track and detect the target but only for levels of SNR down to 4dB. Lower SNR leads to the algorithm not being able to distinguish the target signal from the reverberation. The trained TrBD on the other hand, is able to perform very well for levels of SNR down to 0dB, it is able to track and detect the target and neglect the reverberation. For trajectories passing through areas with high reverberation, the target was lost for a short period of time until it could be retracked again. Overall, the TrBD was successfully implemented on the self-generated data and has a good performance for various target trajectories.
19
Liljeblad, Hugo. « Does dynamic compression impact how well the player tracks multiple targets in a FPS game ». Thesis, Luleå tekniska universitet, Medier, ljudteknik och teater, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-73281.
Texte intégralRésumé :
When navigating a spatially immersive environment like a game, sound can be used to get anapproximate direction and distance of objects, like targets headed for the player. Game sounddesigners can use this knowledge to create interactions. However, processing sound mightalso interfere with players’ abilities to track targets. By reducing the dynamic range of soundswith compression it might change how players interact in games. Whether the ability to trackseveral targets is affected by compression of sounds was investigated with an interactivelistening test where participants were asked to track objects in a game like environment. Thisgame environment was developed through a set of pre-studies that investigated tracking tasksin games and in vision experiments, as well as sound design. The study developed a methodthat is ecologically valid for games and also utilizes prior research in tracking. In the mainexperiment, Subjects tracked four targets among eight objects in four tracking scenarios. Thetracking scenarios were divided into two different conditions, one with compressed soundsand one with uncompressed sounds. Subjects abilities to correctly identify targets in eachcondition were statistically analyzed with a two-paired t-test. The results showed the ability totrack several targets was better in the condition with sounds compressed and the results werestatistically significant.
20
Vestin, Albin, et Gustav Strandberg. « Evaluation of Target Tracking Using Multiple Sensors and Non-Causal Algorithms ». Thesis, Linköpings universitet, Reglerteknik, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-160020.
Texte intégralRésumé :
Today, the main research field for the automotive industry is to find solutions for active safety. In order to perceive the surrounding environment, tracking nearby traffic objects plays an important role. Validation of the tracking performance is often done in staged traffic scenarios, where additional sensors, mounted on the vehicles, are used to obtain their true positions and velocities. The difficulty of evaluating the tracking performance complicates its development. An alternative approach studied in this thesis, is to record sequences and use non-causal algorithms, such as smoothing, instead of filtering to estimate the true target states. With this method, validation data for online, causal, target tracking algorithms can be obtained for all traffic scenarios without the need of extra sensors. We investigate how non-causal algorithms affects the target tracking performance using multiple sensors and dynamic models of different complexity. This is done to evaluate real-time methods against estimates obtained from non-causal filtering. Two different measurement units, a monocular camera and a LIDAR sensor, and two dynamic models are evaluated and compared using both causal and non-causal methods. The system is tested in two single object scenarios where ground truth is available and in three multi object scenarios without ground truth. Results from the two single object scenarios shows that tracking using only a monocular camera performs poorly since it is unable to measure the distance to objects. Here, a complementary LIDAR sensor improves the tracking performance significantly. The dynamic models are shown to have a small impact on the tracking performance, while the non-causal application gives a distinct improvement when tracking objects at large distances. Since the sequence can be reversed, the non-causal estimates are propagated from more certain states when the target is closer to the ego vehicle. For multiple object tracking, we find that correct associations between measurements and tracks are crucial for improving the tracking performance with non-causal algorithms.
21
Mauss, Benoit. « Réactions élastiques et inélastiques résonantes pour la caractérisation expérimentale de la cible active ACTAR TPC ». Thesis, Normandie, 2018. http://www.theses.fr/2018NORMC226/document.
Texte intégralRésumé :
ACTAR TPC (ACtive TARget and Time Projection Chamber) est une cible active de nouvelle génération construite au GANIL (Grand Accélérateur d'Ions Lourds). Les cibles actives sont des cibles gazeuses où le gaz permet de détecter le passage de particules chargées selon le principe des chambres à projection temporelle (TPC). La TPC d'ACTAR est formée d'une anode segmentée de 16384 pixels carrés de 2 mm de côté. La haute densité de voies est gérée par le système électronique GET (General Electronics for TPCs). Ce système digitalise également les signaux sur un intervalle de temps donné, pour une reconstruction 3D complète des évènements. Un démonstrateur huit fois plus petit a d'abord été construit pour vérifier le fonctionnement de l’électronique et la conception mécanique. La finalisation d’ACTAR TPC s’est basée sur les résultats du démonstrateur, qui a été testé avec des faisceaux de 6Li, de 24Mg et de 58Ni. Le commissioning d'ACTAR TPC a été effectué dans le cas de la diffusion résonante sur cible de protons avec des faisceaux de 18O et de 20Ne.Un algorithme de reconstruction des traces mesurées dans la TPC permet d'en extraire les angles et les énergies des ions impliqués dans les réactions. Les résultats sont comparés à des données connues pour déterminer les performances du système de détection. Les résolutions obtenues sur le commissioning à partir de calculs en matrice R valident l'utilisation d'ACTAR TPC pour de futures expériences. Par ailleurs, la diffusion résonante 6Li + 4He réalisée avec le démonstrateur a permis d'étudier les états d’agrégat alpha dans le 10B. Deux résonances à 8.58 MeV et 9.52 MeV sont observées pour la première fois en diffusion élastique dans cette voie de réactionACTAR TPC (ACtive TARget and Time Projection Chamber) is a next generation active target that was designed and built at GANIL (Grand Accélérateur d'Ions Lourds). Active targets are gaseous targets in which the gas is also used to track charged particles following the principles of time projection chambers (TPC). The TPC of ACTAR has a segmented anode of 16384 2 mm side square pixels. The high density of pixels is processed using the GET (General Electronics for TPCs) electronic system. This system also digitizes the signals over a time interval, enabling a full 3D event reconstruction. An eight time smaller demonstrator was first built to verify the electronics operation and the mechanical design. ACTAR TPC's final design was based on results obtained with the demonstrator which was tested using 6Li, 24Mg and 58Ni beams. The commissioning of ACTAR TPC was then carried out for the case of resonant scattering on a proton target using 18O and 20Ne beams. A track reconstruction algorithm is used to extract the angles and energies of the ions involved in the reactions. Results are compared to previous data to determine the detection system performances. Comparing the commissioning data with R matrix calculations, excitation functions resolutions in different cases are obtained. The use of ACTAR TPC is validated for future experiments. Furthermore, alpha clustering was studied in 10B through the resonant scattering 6Li + 4He, carried out with the demonstrator. Two resonances at 8.58 MeV and 9.52 MeV are observed for the first time in elastic scattering with this reaction channel
22
Romero, Ric. « MATCHED WAVEFORM DESIGN AND ADAPTIVE BEAMSTEERING IN COGNITIVE RADAR APPLICATIONS ». Diss., The University of Arizona, 2010. http://hdl.handle.net/10150/194499.
Texte intégralRésumé :
Cognitive Radar (CR) is a paradigm shift from a traditional radar system in that previous knowledge and current measurements obtained from the radar channel are used to form a probabilistic understanding of its environment. Moreover, CR incorporates this probabilistic knowledge into its task priorities to form illumination and probing strategies thereby rendering it a closed-loop system. Depending on the hardware's capabilities and limitations, there are various degrees of freedom that a CR may utilize. Here we will concentrate on two: temporal, where it is manifested in adaptive waveform design; and spatial, where adaptive beamsteering is used for search-and-track functions. This work is divided into three parts. First, comprehensive theory of SNR and mutual information (MI) matched waveform design in signal-dependent interference is presented. Second, these waveforms are used in a closed-loop radar platform performing target discrimination and target class identification, where the extended targets are either deterministic or stochastic. The CR's probabilistic understanding is updated via the Bayesian framework. Lastly, we propose a multiplatform CR network for integrated search-and-track application. The two radar platforms cooperate in developing a four-dimensional probabilistic understanding of the channel. The two radars also cooperate in forming dynamic spatial illumination strategy, where beamsteering is matched to the channel uncertainty to perform the search function. Once a target is detected and a track is initiated, track information is integrated into the beamsteering strategy as part of CR's task prioritization.
23
LEITE, TACITO DANTAS FROTA. « DETERMINATION OF MAJOR, MINOR AND TRACE ELEMENTS IN ROCK SAMPLES BY LA-ICPMS AFTER TARGET PREPARATION BY FUSION WITH LITHIUM BORATES ». PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 2006. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=8759@1.
Texte intégralRésumé :
PETRÓLEO BRASILEIRO S. A.A determinação de elementos traços em amostras de rocha por espectrometria de massas, combinada com ablação a laser (LA-ICPMS), tem se tornado uma importante ferramenta nas investigações em petrogênese, metalogênese e na prospecção de minérios. Apesar do surgimento de uma nova geração de lasers com menor duração de pulso (fs) e comprimento de onda (<266 nm), a calibração é ainda um ponto crítico, pois em geral, não há padrões disponíveis com matriz semelhante. Uma das interferências não espectrais mais relevantes em LA-ICPMS é o fracionamento químico, o qual acarreta diferenças entre as composições do alvo (padrão ou amostra) e da massa ablacionada, comprometendo a exatidão e a repetitividade dos resultados. Quando a análise integral é o objetivo principal, o assemelhamento de matriz pode ser alcançado por simples fusão das amostras e padrões em misturas de meta e tetraboratos, de modo similar ao que é feito, rotineiramente, na análise por fluorescência de raios-X (XRFA). Este trabalho relata metodologia para a determinação de elementos traços em amostras de basaltos, provenientes de sítios de exploração de petróleo. Os experimentos foram realizados com um sistema de ablação a laser CETAC LSX-100 em combinação com um espectrômetro ELAN 5000 ICPMS. Uma mistura de argônio-nitrogênio (2 % N2, 98 % Ar) foi utilizada como gás carreador, com o intuito de aumentar a massa ablacionada, e consequentemente, melhorar as intensidades de sinal e reduzir os limites de detecção. Conectou-se uma câmara ciclônica antes da tocha do ICP, com o objetivo de uniformizar o tamanho das partículas de aerossol, e deste modo, melhorar a repetitividade da medição e a robustez do plasma. A título de comparação, análises também foram feitas sem o emprego desta câmara. Padrões de calibração foram preparados a partir de dois materiais de referência certificados, o basalto NIST SRM 688 e a obsidiana NIST SRM 278. Os padrões de rochas pulverizadas foram misturados e homogeneizados com fundente de borato de lítio (CLAISSE, puro, 75 % Li2B4O7, 25 % LiBO2) nas proporções mássicas de rocha: fundente de 1:5, 1:11, 1:23, 1:47, respectivamente, obtendose, deste modo, cada padrão em quatro diferentes concentrações. O padrão interno escolhido foi o In, tendo sido este adicionado antes da fusão, resultando em alvos com a concentração de 100 mg kg(-1) neste elemento. Obtiveram-se os brancos, de modo similar, usando o fundente borato de lítio. A validação metodológica foi feita empregando-se o basalto (GSJ, JB-2) e o granito (NIMG, SARM-1), tendo sido a partir destes, preparados vidros com a proporção mássica (amostra: fundente) de 1:5 e contendo o padrão interno. Todas as fusões foram feitas em um forno de fusão automático (CLAISSE Fluxy). Análises por ICPMS e ICP OES foram feitas após dissolução de fragmentos dos alvos em HNO3, para verificação de possíveis perdas de elementos voláteis. Quarenta elementos foram determinados, a maioria das curvas de calibração apresentou coeficiente de determinação (R2) maiores que 0,995. Limites de detecção variaram de 0,013 mg kg(-1) para Tb, até 0,6 mg kg(-1) para Zn. Estes valores foram melhorados para vários elementos pelo uso da câmara ciclônica (V, Zn, Rb, Y, Nb, Ba, Ce, Sm, Tb, Dy, Ho, Tm). Nas análises do basalto (GSJ, JB-2) e do granito (NIMG, SARM-1), a exatidão foi melhor do que 5 % para V, Sr, Y, Ba, Ce, Nd, Yb e Lu; entre 5-10 % para: Sc, Zn, Rb, Tm, e de 10-20 % para: Co, Zr, La e Tb. A repetitividade foi melhor do que 5% para V, Rb, Sr, La, Nd, Ta; entre 5-10 % para: Sc, Co, Zn, Sr, Y, Zr, Ba, Tb, Yb; e de 10-20 % para: Ce, Tm, Lu e Hf. Foi utilizado ainda o método semiquantitativo TotalQuant II o qual, dentro da incerteza esperada para este tipo de calibração (cerca de 10 % a 20 %), forneceu resultados concordantes com calibração externa quantitat
Determination of trace elements in rock samples by laser ablation inductively coupled plasma mass spectrometry (LA-ICPMS) has become an important tool for investigations in petrogenesis, metallogenesis and ore prospecting. However, despite the availability of new generation lasers with shorter pulse duration (fs) and wave length (<266 nm), calibration remains still a critical issue when matrixmatched standards are not available. One of the most serious non- spectral interference in LA-ICPMS is chemical fractionation, which causes compositions of standard and sample and their respective ablated masses to be different, thus compromising accuracy and precision of the results. When bulk analysis is the main objective, matrix matching can be achieved by the simple fusion of samples and standards with meta/tetraborates fluxes, similar to what is routinely used in XRFA. This work reports on our experience with this procedure in the analysis of basaltic rocks, aiming at the trace element characterization of host rocks from oil exploration sites in Brazil. The experiments were performed with a CETAC LSX- 100 laser ablation system (Nd:YAG, 266 nm, operated in the Q-switched and scanning mode) coupled to an ELAN 5000 ICPMS. An argon- nitrogen mixture (2 % N2, 98 % Ar) was used as carrier gas to enhance the mass of material ablated, thus increasing signal intensities and reducing detection limits. A cyclonic spray chamber was arranged just before the ICP-torch as a tentative to uniform aerosol particle size for improving measurement repeatability and robustness of the plasma. For comparison, the system was also operated without a spray chamber. Calibration samples were prepared from two standard reference materials: NIST SRM 688 basalt and NIST SRM 278 obsidian. The powdered rock standards were mixed and homogenized with a lithium borate flux (CLAISSE, pure, 75 % Li2B4O7, 25 % LiBO2) using rock-to-flux mass ratios of 1:5, 1:11, 1:23 and 1:47, respectively, thus obtaining each standard in four different analyte concentrations. Indium was used as an internal standard (IS) and was added before fusion to achieve targets with IS concentration of 100 mg kg(-1). Blanks from the lithium borate flux were produced in a similar way. Method validation was performed with GSJ basalt JB-2 and NIMG granite SARM-1, prepared at a constant sampleto- flux mass ratio of 1L:5 and containing also the IS. All fusions were performed in an automated furnace (CLAISSE Fluxy). Solution nebulization ICP-MS/OES after dissolution of smaller target pieces in HNO3 was used to assess for volatilization losses. Forty elements were determined and good linearity of the calibration curves was obtained and for most of them the correlation coefficient (R2) was higher than 0.995. Detection limits ranged from 0.013 mg kg(-1) for Tb to 0.6 mg kg(-1) for Zn, and improved for several elements by using a cyclonic spray chamber (e.g. V, Zn, Rb, Y, Nb, Ba, Ce, Sm, Tb, Dy, Ho, Tm). In the analysis of GSJ basalt JB-2 and NIMG granite SARM-1, accuracy was better than 5 % for: V, Sr, Y, Ba, Ce, Nd, Yb, and Lu; between 5-10 % for: Sc, Zn, Rb, Tm, and 10-20 % for: Co, Zr, La and Tb. Repeatability was better than 5 % for: V, Rb, Sr, La, Nd, Ta, between 5-10% for: Sc, Co, Zn, Y, Zr, Ba, Tb, Yb, and 10-20 % for: Ce, Tm, Lu and Hf. Additionally, the semiquantitative TotalQuant II calibration was applied, which gave, within the expected uncertainty for this calibration method (10 % to 20 %), concordant results when compared to the quantitative external calibration procedure. Preliminary results on the application of these methods for the determination of trace elements in basaltic host rocks from oil exploration sites will be shown.
24
Huffman, Kristyn, et Kristyn Huffman. « Increasing Effective Patient-Triage Nurse Communication Using a Targeted History Question ». Diss., The University of Arizona, 2017. http://hdl.handle.net/10150/626701.
Texte intégralRésumé :
This quality improvement project identified a need to improve patient placement between the Fast Track and the Emergency Department treatment areas of an urban Southern Arizona hospital. The current triage process at this hospital excludes patient past medical history, limiting the information given to triage nurses when assigning patient acuity scores and determining placement in the ED. This project sought to improve patient to nurse communication during the triage interview process by educating nurses to ask a ‘targeted history’ question: a question created to obtain concise past medical history information related to the patient’s chief complaint. This targeted history question was worded as “Have you been treated for [chief complaint] before?” Chart audits were performed to gather quantitative data on patient placement, ESI scores, triage interview times, and nursing compliance rates. Stakeholders were also asked open-ended questions regarding their perceptions of triage and the integration of the targeted history question. These interviews were recorded, transcribed, and coded for common categories. Results show low nursing compliance with asking the targeted history question. However, almost two-thirds of triage notes mentioned some form of past medical history – showing that triage nurses assess for pertinent past medical history without prolonging total triage times. Additionally, stakeholder interviews showed healthcare personnel felt the targeted history question helped with gathering useful information and patient placement, and that past medical history is an important part of triage.
25
Schedin, Oscar. « Target Spectrums For Mastering : A comparison of spectral stylistic conventions between rock and vocal-based electronic music ». Thesis, Luleå tekniska universitet, Institutionen för ekonomi, teknik, konst och samhälle, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-84660.
Texte intégralRésumé :
Through the analysis of the spectral characteristics of thousands of mastered (or remastered) commercial recordings from a variety of genres over the history of popular music, researchers have studied stylistic trends and spectral conventions. The aim of this study was to further explore, analyse and compare the spectral characteristics of two broad but distinct popular music genres: rock and vocal-based electronic music. The main reason for this choice of genres being that rock generally predominantly is based on (amplified) acoustical elements (e.g. acoustic drums and acoustic/electric bass/guitars) and that electronic music generally predominantly is based on electronic elements (e.g. beats and synthesizers). The stimuli for the study consisted of 24 top-five hit songs from the Billboard charts between 2016-2020, divided by genre. A fast fourier transform approach was used for the computation of target spectrums as well as low level descriptors for the two independent datasets of recordings. Spectral analysis followed with the goal of answering the following research questions: What do the spectral stylistic conventions appear to be in rock versus vocal-based electronic music and what spectral differences/similarities exists between these two distinct popular music genres? The results showed that there were some significant spectral differences between the two genres, especially noticeable in the low end of the frequency spectrum. Other genre-specific spectral trends and overall spectral conventions were found as well.
26
JUNIOR, RAINERIO ESCALFONI. « DETERMINATION OF MINOR AND TRACE ELEMENTS IN ROCK SAMPLES BY LA-ICPMS : PROGRESS IN THE UTILIZATION OF BORATE GLASSES AS TARGETS ». PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 2009. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=15411@1.
Texte intégralRésumé :
PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIROA presente dissertação é uma continuação de pesquisas desenvolvidas por Leite (2006) visando à análise multielementar de rochas (basaltos, obsidianas e folhelhos) por espectrometria de massa com plasma indutivamente acoplado (ICPMS), em combinação com ablação a laser (LA) e utilizando-se vidro borato como alvo de análise. Como no trabalho anterior, os experimentos foram realizados com um sistema LSX-100 (CETAC) acoplado ao espectrômetro Elan 6000 ICPMS (PerkinElmer-Sciex). Como gases carreadores na câmara de ablação foram testados gases puros (Ar, He) e misturas (Ar-He, Ar-N2). Também foram avaliados parâmetros operacionais do laser, tais como: energia de saída, focalização, velocidade de varredura e freqüência de disparo. As novas condições analíticas foram testadas com os padrões preparados por Leite (2006), calculandose os limites de detecção, a exatidão e precisão. Os limites de detecção para 40 elementos (Na, Al, Si, P, K, Ca, Sc, V, Cr, Mn, Fe, Co, Ni, Zn, Ga, Rb, Sr, Y, Zr, Nb, Sb, Ba, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Hf, Ta, Th, U) ficaram compreendidos entre 0,004 mg kg-1 (Tb) e 850 mg kg-1 (Si). Exatidões foram estimadas a partir de análises de materiais de referência certificados (USGS BIR-1, BHVO-2, SCo-1), obtendo-se erros < 10% para Sc, V, Co, Ni, Zn, Rb, Y, Ba, La, Pr, Nd, Tb, Lu e Th e entre 10-20% Na, Al, Si, P, K, Ca, Mn, Fe, Ga, Sr, Y, Zr, Nb, Ce, Sm, Eu, Gd, Dy, Er, Yb, Lu, Hf e U. Precisões, calculadas a partir dos desvios-padrão residuais das curvas de calibração, ficaram em média em 6%, sendo de no máximo 10% para 30 elementos (Na, Al, Si, P, Ca, Sc, V, Cr, Mn, Fe, Co, Zn, Ga, Sr, Y, Zr, Sb, La, Ce, Pr, Eu, Gd, Tb, Dy, Er, Tm, Yb, Lu, Hf e Ta). Foram preparados novos padrões de calibração a partir de dois materiais de referência certificados, o basalto USGS BCR-2 e o folhelho USGS SGR-1. Os novos padrões foram validados utilizando os padrões preparados por Leite (2006) e através de análises independentes. Os coeficientes de determinação (R2) para 24 elementos (Na, Mg, Al, K, Sc, V, Cr, Mn, Fe, Co, Ga, Rb, Sr, Y, Nb, Ce, Nd, Eu, Ho, Yb, Lu, Ta, Pb, U) foram maiores que 0,98 e para os outros 16 elementos, no mínimo, maiores que 0,95 (Si, P, Ca, Zn, Zr, Ba, La, Pr, Sm, Gd, Tb, Dy, Er, Tm, Hf, Th). As metodologias foram utilizadas na caracterização multielementar de amostras de folhelhos, de grande interesse geológico na área de petróleo, e os resultados preliminares são apresentados e discutidos.
The present master dissertation is a continuation of a research study developed by Leite (2006) aiming at the multielemental analysis of rock samples (basalts, obsidians and shale) by inductively coupled plasma mass spectrometry (ICPMS), in combination with laser ablation (LA) and using borate glass as analytical targets. As in the former work, the experiments were performed with a LSX-100 (CETAC) system coupled to an Elan 6000 ICPMS (PerkinElmer-Sciex). Pure gases (Ar, He) and mixtures (Ar-He, Ar-N2) were tested as carrier gas for transporting the aerosol from the ablation cell to the plasma. Different operational parameters of the laser, such as energy, focus, scanning speed and laser frequency were also studied. The new and optimized analytical conditions were tested with the calibration standards prepared by Leite (2006), and limits of detection (LOD), accuracies and precisions (RSD) were estimated. For 40 elements (Na, Al, Si, P, K, Ca, Sc, V, Cr, Mn, Fe, Co, Ni, Zn, Ga, Rb, Sr, Y, Zr, Nb, Sb, Ba, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Hf, Ta, Th, U), the LODs were in the range of 0,004 mg kg-1 (Tb) and 850 mg kg-1 (Si). Accuracies, estimated from the analysis of certified reference materials (USGS BIR-1, BHVO-2, SCo-1), were better 10% for Sc, V, Co, Ni, Zn, Rb, Y, Ba, La, Pr, Nd, Tb, Lu, and Th, and between 10 to 20% for Na, Al, Si, P, K, Ca, Mn, Fe, Ga, Sr, Y, Zr, Nb, Ce, Sm, Eu, Gd, Dy, Er, Yb, Lu, Hf, and U. Analytical precisions, calculated from the residual standard deviations of calibration curves were typically 6%, and at most 10% for 30 elements (Na, Al, Si, P, Ca, Sc, V, Cr, Mn, Fe, Co, Zn, Ga, Sr, Y, Zr, Sb, La, Ce, Pr, Eu, Gd, Tb, Dy, Er, Tm, Yb, Lu, Hf, Ta). New targets were prepared from two certified reference materials: (USGS BCR-2 (basalt) and USGS SGR-1 (shale). These new calibration standards were validated against those prepared by Leite (2006) and also by an independent technique. Coefficients of determination (R2) for 24 elements (Na, Mg, Al, K, Sc, V, Cr, Mn, Fe, Co, Ga, Rb, Sr, Y, Nb, Ce, Nd, Eu, Ho, Yb, Lu, Ta, Pb, U) were better than 0.98, and for further 16 elements better than 0.95 (Si, P, Ca, Zn, Zr, Ba, La, Pr, Sm, Gd, Tb, Dy, Er, Tm, Hf, Th). The method was then used for the multielement characterization of marine shale samples, which are of great geological interest in petroleum research, and preliminary results are presented and discussed.
27
Eidehall, Andreas. « Tracking and threat assessment for automotive collision avoidance ». Doctoral thesis, Linköping : Department of Electrical Engineering, Linköpings universitet, 2007. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-8338.
Texte intégral
28
Lundquist, Christian. « Sensor Fusion for Automotive Applications ». Doctoral thesis, Linköpings universitet, Reglerteknik, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-71594.
Texte intégralRésumé :
Mapping stationary objects and tracking moving targets are essential for many autonomous functions in vehicles. In order to compute the map and track estimates, sensor measurements from radar, laser and camera are used together with the standard proprioceptive sensors present in a car. By fusing information from different types of sensors, the accuracy and robustness of the estimates can be increased. Different types of maps are discussed and compared in the thesis. In particular, road maps make use of the fact that roads are highly structured, which allows relatively simple and powerful models to be employed. It is shown how the information of the lane markings, obtained by a front looking camera, can be fused with inertial measurement of the vehicle motion and radar measurements of vehicles ahead to compute a more accurate and robust road geometry estimate. Further, it is shown how radar measurements of stationary targets can be used to estimate the road edges, modeled as polynomials and tracked as extended targets. Recent advances in the field of multiple target tracking lead to the use of finite set statistics (FISST) in a set theoretic approach, where the targets and the measurements are treated as random finite sets (RFS). The first order moment of a RFS is called probability hypothesis density (PHD), and it is propagated in time with a PHD filter. In this thesis, the PHD filter is applied to radar data for constructing a parsimonious representation of the map of the stationary objects around the vehicle. Two original contributions, which exploit the inherent structure in the map, are proposed. A data clustering algorithm is suggested to structure the description of the prior and considerably improving the update in the PHD filter. Improvements in the merging step further simplify the map representation. When it comes to tracking moving targets, the focus of this thesis is on extended targets, i.e., targets which potentially may give rise to more than one measurement per time step. An implementation of the PHD filter, which was proposed to handle data obtained from extended targets, is presented. An approximation is proposed in order to limit the number of hypotheses. Further, a framework to track the size and shape of a target is introduced. The method is based on measurement generating points on the surface of the target, which are modeled by an RFS. Finally, an efficient and novel Bayesian method is proposed for approximating the tire radii of a vehicle based on particle filters and the marginalization concept. This is done under the assumption that a change in the tire radius is caused by a change in tire pressure, thus obtaining an indirect tire pressure monitoring system. The approaches presented in this thesis have all been evaluated on real data from both freeways and rural roads in Sweden.SEFS -- IVSS
VR - ETT
29
Mesa, Rodolfo. « Simplifying Sample Preparation using Fabric Phase Sorptive Extraction : Analysis of Trace Targeted Pollutant Residues in Environmental, Biological and Food Samples ». FIU Digital Commons, 2017. https://digitalcommons.fiu.edu/etd/3513.
Texte intégralRésumé :
Sample preparation is an essential component of analytical methods in chemistry. It is not only necessary but also presents an opportunity to increase the effectiveness of the method significantly. There are various commercially available technologies for sample preparation, including numerous variations of LLE, SPE, and SPME. However, these technologies all present significant deficiencies, including the inability to extract directly from complex samples such as whole milk. Instrumental analysis has been improved greatly in the last two decades but still is not applicable to complex samples without sample preparation.
This work presents the theory of FPSE, including the synthesis of sol-gel sorbents, coating of FPSE cellulose substrates and the mechanism of retention. Original research data presented herein introduce a comprehensive view on possible applications of FPSE in forensic chemistry and otherwise. Five distinct FPSE-based methods were rigorously developed for analysis of targeted pollutant residues. These methods were validated and compare to leading methods published in peer-reviewed literature quite favorably. Four of the methods were coupled to HPLC-UV and designed for trace or ultra-trace analysis of PAHs, BTEX, substituted phenols and nitroaromatic explosives, respectively. An additional FPSE-based method was developed and validated for direct analysis of BPA and five estrogenic EDCs in commercially purchased whole milk. This latter was coupled to both HPLC-UV and HPLC(QQQ)-MS/MS.
The applicability of FPSE(PTHF) media was also tested for screening of aqueous samples and subsequent storage of analytes on the sorbent. My study included simultaneous extraction of a mixture of eight forensically significant compounds with various physicochemical properties and effective storage of each compound in frozen and ambient conditions for 32 weeks. These findings suggest that the storage ability of FPSE media can be extended as long as necessary, which is very significant in forensic laboratories where evidence often needs to be stored in a costly manner that may not be as effective in maintaining the chemical composition of the sample.
30
Chomjak, Ján. « Využití robotické totální stanice pro měření jeřábových drah ». Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2014. http://www.nusl.cz/ntk/nusl-227141.
Texte intégralRésumé :
This diploma thesis deals with application of robotic total station for crane tracks measuring. To determinate straight of rail tracks was used system of automatic target recognition. One crane track was measured by two methods. Horizontal deviation from straight direction was determinated directly by the method “line of sight” and indirectly using measuring angles and lengths. To determinate height continuance was used engineering and trigonometric leveling. The results of measuring proved, that reached deviations between methods are minimal, so we consider them as equal. System system of automatic target recognition reliably and with sufficient accuracy aims to the prism-centre.
31
Meier, Kevin Christopher. « Developing a Guidance Law for a Small-Scale Controllable Projectile Using Backstepping and Adaptive Control Techniques and a Hardware System Implementation for a UAV and a UGV to Track a Moving Ground Target ». BYU ScholarsArchive, 2012. https://scholarsarchive.byu.edu/etd/3378.
Texte intégralRésumé :
The work in this thesis is on two topics. The first topic focuses on collaboration between a UAV and a UGV to track a moving ground target. The second topic focuses on deriving a guidance law for a small-scale controllable projectile to be guided into a target. For the first topic, we implement a path planning algorithm in a hardware system for a UAV and UGV to track a ground target. The algorithm is designed for urban environments where it is common for objects to obstruct sensors located on the UAV and the UGV. During the hardware system's implementation, multiple problems prevented the hardware system from functioning properly. We will describe solutions to these problems. For the second topic, we develop a guidance law for a small-scale controllable projectile using Lyapunov analysis techniques. We implement a PID controller on the body-axes pitch rate and yaw rate of the projectile such that the behavior of the pitch rate and yaw rate can be approximated as a second order system. We derive inputs for the pitch rate and yaw rate using backstepping and adaptive control techniques. The guidance law we develop guarantees the rocket will point at its intended destination. Additionally, we present expressions for the kinematics and dynamics of the rocket's motion and define the forces and moments that act on the rocket's body.
32
Kizilgul, Serdar A. « Study of Pion Photo-Production Using a TPC Detector to Determine Beam Asymmetries from Polarized HD ». Ohio University / OhioLINK, 2008. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1210629380.
Texte intégral
33
Santamaria, Clémentine. « Quest for new nuclear magic numbers with MINOS ». Thesis, Paris 11, 2015. http://www.theses.fr/2015PA112153/document.
Texte intégralRésumé :
Le détecteur MINOS a été développé jusqu'à mi-2013 pour la spectroscopie γ prompte de noyaux très exotiques à partir de réactions d’arrachage de protons. Il est composé d'une cible épaisse d'hydrogène liquide pour augmenter la luminosité et d’une chambre à projection temporelle (TPC) pour reconstruire la position du vertex de réaction et de compenser l'effet de la cible épaisse sur la correction Doppler.La chambre à projection temporelle a été développée avec l'expertise du CEA-Irfu sur les détecteurs gazeux de type Micromegas. Dans un premier temps, différentes solutions pour la TPC ont été testées dans une chambre d'essai avec une source α et des mesures de rayons cosmiques. Des muons cosmiques ont été détectés pour la première fois en utilisant la chambre d'essai en début 2013 et ont validé l'utilisation d'un plan de détection Micromegas. Le premier prototype de TPC a été achevé en mai 2013 et nous avons utilisé un banc de rayons cosmiques pour estimer l’efficacité de la TPC.MINOS a ensuite été expédié au Japon et un test de performance sous faisceau a été réalisée à l'installation médicale HIMAC (Chiba, Japon) avec deux cibles minces au lieu de la cible épaisse d'hydrogène pour valider l'algorithme de reconstruction et la résolution de la position du vertex. Un algorithme de reconstruction de traces basé sur la transformée de Hough a été mis au point pour l'analyse des données, testé avec ces données, et comparé à des simulations.La première campagne de physique avec MINOS a eu lieu en mai 2014, avec SEASTAR. Elle s’est concentrée sur la première spectroscopie des ⁶ ⁶ Cr, ⁷⁰,⁷²Fe et ⁷⁸Ni. L'analyse de la spectroscopie du ⁶ ⁶Cr a révélé deux transitions, assignées aux deux premiers états excités. Une interprétation avec des calculs de modèle en couches montre que le maximum de collectivité quadripolaire se produit à N = 40 le long de la chaîne isotopique de chrome.Le ⁶ ⁶Cr est toujours placé dans la région de l’Îlot d’Inversion à N = 40 et les calculs de modèle en couches ainsi que la comparaison avec des calculs basés sur HFB suggèrent une extension de cet Îlot d’Inversion vers N = 50 en dessous du ⁷⁸Ni. L'analyse des ⁷⁰,⁷²Fe effectuée par C. Louchart (TU Darmstadt, Allemagne) révèle la même tendance que pour les isotopes de chrome. Les données et notre interprétation par le modèle en couches suggère une grande collectivité les Cr et Fe riches en neutrons, éventuellement jusqu'à N = 50, ce qui remettrait en cause la solidité de la fermeture de couche N = 50 en dessous du ⁷⁸NiThe MINOS device has been developed until mid-2013 for in-beam γ spectroscopy of very exotic nuclei from proton knockout reactions. It is composed of a thick liquid hydrogen target to achieve higher luminosities and a Time Projection Chamber (TPC) to reconstruct the vertex position and compensate for the thick target effect on the Doppler correction.The Time Projection Chamber has been developed with the expertise of CEA-IRFU in gas detectors and Micromegas detectors. At first, different solutions for the TPC were tested in a test chamber with an α source and cosmic-ray measurements. Cosmic rays were detected for the first time using the test chamber in early 2013 and validated the use of a Micromegas detection plane. The first TPC prototype was finished in May 2013, and we used a cosmic-ray bench to estimate the effiiciency of the TPC. The MINOS device was then shipped to Japan and an in-beam performance test was performed at the HIMAC medical facility (Chiba, Japan) with two thin targets instead of the thick hydrogen target to validate the tracking algorithm and the vertex position resolution. A tracking algorithm for the offline analysis based on the Hough transform has been developed, tested with the data, and compared with simulations.The first physics campaign using MINOS took place in May 2014 with SEASTAR. It focused on the first spectroscopy of ⁶ ⁶ Cr, ⁷⁰,⁷²Fe, and ⁷⁸Ni. The analysis of the ⁶⁶Cr spectroscopy revealed two transitions, assigned to the two first excited states. An interpretation with shell model calculations shows that the maximum of quadrupole collectivity occurs at N=40 along the Cr isotopic chain.⁶⁶Cr is still placed in the Island of Inversion region of N=40 and the shell model calculations as well as comparison with HFB-based calculations suggest an extension of this Island of Inversion towards N=50 below ⁷⁸Ni. The analysis of ⁷⁰,⁷²Fe performed by C. Louchart (TU Darmstadt, Germany) reveals the same trend as for Cr isotopes, with a maximum of deformation at N=42. The full data set and our shell-model interpretation suggests a large collectivity for neutron-rich Cr and Fe, possibly up to N=50, questioning the robustness of the N=50 shell closure below ⁷⁸Ni
34
TYAGI, ADITYA. « MULTIPLE OBJECT TRACKING BY DECISION MAKING USING MEMORYLESS STATE TRANSITIONS ». Thesis, 2018. http://dspace.dtu.ac.in:8080/jspui/handle/repository/16516.
Texte intégralRésumé :
This thesis work formulates tracking as decision making process where a tracker should
follow an object despite ambiguous frames and having some limited computational
budget. In tracking by detection, data association is main challenge i.e. to accurately
associate noisy/ambiguous detected object of current frame to tracked objects from
previous video frames and are linked to form trajectories of targets. In this work object
tracking is done by making decisions regarding transition of memoryless states. The time
for which an object is present in different video frames is modeled by memoryless states
specifically known as Markov decision process(MDP). It has four different states: active,
tracked, lost and inactive. Every new detected object enters active state. An active target
can transition to tracked or inactive i.e. true positive from object detector should
transition to tracked state, while a false alarm goes to inactive state. A tracked target will
remain tracked, or transition to lost if the target is lost due to some reason, such as
occlusion or disappearance from the field of view of the camera. Lost target can stay as
lost if not viewed for some frames, or get back to tracked state if it appears again, or
transition to inactive state if lost for very long time. Finally, inactive state is the terminal
state for any target, i.e. an inactive target stays as inactive forever. This is for single
object, likewise for tracking multiple objects several Markov decision processes are
assembled. For tracking of object template, iterative Lucas-Kanade tracker is used which
works by computing optical flow. Whenever the tracker fails to track the target due to
change in appearance and the present state transitions to lost, only then the template is
updated. History of previous templates are stored and the tracking template is the mean
vi | P a g e
of past templates from history of the tracked target. For the data association of tracked
target and current detections, I have used determinative Hungarian algorithm and
Murty’s best assignments. Similarity function needs to be learned which is equal to
learning a policy for Markov decision process for data association. Policy determines
which action to take for state transitioning. Reinforcement learning is used for policy
learning that takes benefit from advantages of both offline and online learning in data
association. Initially providing the ground truth trajectory of a target and similarity
function, Markov decision process attempts to track the target and takes feedback from
the ground truth. According to obtained feedback, decision process updates the similarity
function to improve tracking. Similarity function is updated only when decision process
makes a mistake in data association. Lastly, training is finished when Markov decision
process can successfully track the target. This framework can handle the birth/death and
appearance/disappearance of objects by treating them as state transitions. Also it is very
robust in handling occlusions.
35
CHEN, ZHI-LONG, et 陳志龍. « The design of radar area target tracker ». Thesis, 1993. http://ndltd.ncl.edu.tw/handle/81049254977414306735.
Texte intégral
36
Hu, Chun-Wei, et 胡峻維. « Building an Eye Tracker System for Target Estimation in 3D ». Thesis, 2016. http://ndltd.ncl.edu.tw/handle/q83k3q.
Texte intégralRésumé :
碩士國立臺灣師範大學
電機工程學系
104
This research presents an approach to build an eye tracker for 3D target estimation. First, a wearable eye tracer, which two eye cameras are set on, is used. By analyzing the data calculated by binocular eye tracker, the 3D coordinates of the target can be estimated. Second, the two-axis control platform built by two servo motors and a laser pen are used to point the object user is looking at by receiving the 3D data obtained from the eye tracker system. Eye tracker is a device which estimates the position the user stares at by detecting the moving pupil. In this research, 2-D points of glint are transformed into 3-D points of glint to calculate the coordinates of object in real environment. Besides, this research increases the effective estimated distance by 100cm, and decreases the error by 2 degree. In addition to use 2D Mapping, this research also presents an improved 3D Modeling algorithm to estimate the gaze line (visual axis).
37
楊修明. « The research and development of light source target tracer ». Thesis, 1992. http://ndltd.ncl.edu.tw/handle/57159285346115329291.
Texte intégral
38
Yang, Maw-Rong, et 楊茂榮. « The Research of Radar Target Track Smoothing and Compression ». Thesis, 2007. http://ndltd.ncl.edu.tw/handle/92915296200082292284.
Texte intégralRésumé :
博士大葉大學
電機工程學系
95
Data association algorithm is the most important technique in a multiple-target tracking system. In this dissertation, a method using a Competitive Hopfield Neural Network (CHNN) is proposed for data association. In other hand, based on the CHNN, the radar track smoothing and is also investigated in this dissertation. In this approach, the CHNN differs from the original Hopfield network in that a competitive winner-take-all mechanism is imposed. In order to have completely tracking process, the maneuvering procedure is also applied. In order to analyze the performance of this system, a computer simulation algorithm is conducted and the simulation results indicate that this approach successfully obtains the better radar track.
39
Chu, Tung-te, et 朱東德. « The Numerical Simulation of Optimal Design in Target Tracker by α-β-γ-δ Filter ». Thesis, 2012. http://ndltd.ncl.edu.tw/handle/93496400873184875903.
Texte intégralRésumé :
博士國立高雄第一科技大學
工程科技研究所
100
Abstract In modern tracking analysis, many researchers have attempted the various models of the target tracking process. General, target tracking is the important problem in military and civilian fields. Many mathematical models have been formulated to manipulate the target tracking system in the world. In the mid 1950’s, relatively simple α-β and α-β-γ filter trackers were developed to deal with this problem. Their advantages are simple computation and quick response when target maneuvering. Nevertheless, it is to be more adaptable under complicated situation in multi-target tracking or changeable target. The achievements of the dissertation are as follows: 1. To further predict the acceleration and improve the tracking accuracy, an additional state value called jerk that is time derivative of acceleration will need to be observed. As a result, it exhibits significant improvement in tracking accuracy over the α-β-γ filter. 2. Not unexpectedly, however, the new α-β-γ-δ filter takes more computation time in the optimization process. To overcome this weakness, an optimal simulation technique via Genetic Algorithm (GA) is proposed. The developed GA-based α-β-γ-δ filter finds not only the optimal set of filter parameters to minimize position tracking errors but could also reduce the computation time in some time steps. 3. Besides, two heuristic methods (one is GA method, the other is Taguchi method.) are combined together for improving tracking accuracy. Finally, the result shows it leads to get more tracking accuracy. 4. Furthermore, the Evolutionary Programming (EP) algorithm is then introduced. As a result, the developed EP-based α-β-γ-δ filter also finds not only the optimal set of filter parameters to minimize position tracking errors but could also reduce the computation time. 5. In this paper, it is also to compare the tracking accuracy between GA-based α-β-γ-δ filter and EP-based α-β-γ-δ filter. The result shows the same tracking accuracy. 6. The applications of others shall be explored in future. As above mention, another algorithm method can be explored in target tracking process for optimization in future. Keywords: target tracker; Genetic Algorithm; the α-β-γ-δ filter; the α-β-γ filter; the GA-based α-β-γ-δ filter; Evolutionary Programming; the EP-based α-β-γ-δ filter
40
Su, Chien-Chang, et 蘇建彰. « Low-power Branch Target Buffer Scheme by using Taken Branch Trace ». Thesis, 2008. http://ndltd.ncl.edu.tw/handle/79847393523536196628.
Texte intégralRésumé :
碩士大同大學
資訊工程學系(所)
96
In this thesis, we proposed a new branch prediction scheme called Taken Branch Prediction (TBP) to replace traditional architecture. The major mechanism of TBP is that the traditional Branch Target Buffer (BTB) is replaced by a new table called Taken Branch Target Buffer (TBTB). The traditional BTB is lookuped every fetch cycle, but the TBTB is only lookuped when there is instruction seems likely to be a taken branch. As the instruction is likely to be a normal instruction, the TBP is not active. By dynamically profiling the taken branch trace during program execution, our new scheme will almost achieve the goal of one BTB lookup per taken branch. We use Wattch and SPEC CPU2000 integer and floating-point benchmarks to evaluate the power and performance of this architecture. The simulation tool is the SimpleScalar which is cycle-accurate with cycle-by-cycle. The experimental results show that our scheme can reduce the branch prediction energy consumption by 39.86% and 52.54% for integer and floating-point benchmarks respectively with only 0.66% performance loss in average for SPEC CPU2000.
41
Schneider, Ronald Alfred Bernd. « The development, analysis and evaluation of an optical tracker for tracking high-speed, manoeuvering targets ». Thesis, 2015. http://hdl.handle.net/10539/18621.
Texte intégralRésumé :
A DISSERTATION SUBMITTED TO THE FACULTY OF ENGINEERING,
UNIVERSITY OF THE WITWATERSRAND, JOHANNESBURG, FOR THE
DEGREE OF MASTER OF SCIENCE.
PRETORIA, APRIL 1981This dissertation presents the design for an optical tracker which accurately quantifies the 1ine-of-sight between a target and the optical tracker. An optical tracker forms an essential element of defensive installations, yet publications on tracking schemes for optical trackers, as opposed to radar trackers, are hard to find. In this dissertation a comprehensive analysis of an optical tracker for high-speed, m a n o e u v e n n g targets has been d o n e . The optical tracker was to be mobile, and therefore subject to vehicle motion perturbations. A literature survey was m a d e , giving an overview of methoos available for tracking such targets and quantifying the resulting line-of-sight. The options considered included line-of-sight data obtained as outputs of Kalman or Linear Regression Filters of various orde r s . Tracking aids using linear filters, among o t h e r s , were also presented in the literature. The human operator was seen to be an integral part of the optical tracker. The literature survey pointed out some of the advantages inherent in including the human operator in series in the loop, but it was clear that difficulties would arise when trying to design an optimized controller around the human operator. The approach taken in this dissertation was to make a mathe= mat ical model of the system so that the controller could be analyzed, simulated and evaluated in the shortest possible time and at the lowest possible cost. This included human operator models a n d , in some cases, actual human operators. First the equations of motion for the gimballed platform containing the stabilized optical element were derived from first principles. Using the linearized version of these equations, classical controller deciqn methods (e.g. Root Locus techniques, Bode diagrams) were applied to determine the trans = fer function of the optimum stabilization control loop. The non-linear equations of motion were used to construct a simu= lator on which the controller could be tuned. The performance of the stabilization loops was found with respect to base motion stabilization as well as to input co m m a n d . Non-linearz
42
Bentley, Ian. « Track Persistence in Wireless Sensor Networks ». Thesis, 2010. http://hdl.handle.net/1974/6033.
Texte intégralRésumé :
In this thesis we directly consider an object tracking problem for wireless sensor networks (WSNs), called track persistence. Track persistence temporally extends the problem of object tracking by seeking to store and retrieve the entire history of an object. To provide an initial solution to track persistence, we develop two distinct algorithms. The first algorithm, update to sink, translates track persistence into a centralized problem. The second algorithm, a linked list-like algorithm, builds a dynamic data structure as the object traverses the network, and rebuilds the object history distributively upon demand. We conduct worst case analysis upon both of these algorithms. Finally, we implement a simulation environment and run a number of tests upon both algorithms. Track persistence is a very challenging problem, and this thesis contributes a pair of solutions which stand as a basis for future research.Thesis (Master, Computing) -- Queen's University, 2010-09-09 12:56:50.921
43
HSIAO, YUNG-FANG, et 蕭詠芳. « A Study of Dynamic Detecting Target Position by Analyzing the Unmanned Vehicle Track Data ». Thesis, 2018. http://ndltd.ncl.edu.tw/handle/hrc3ke.
Texte intégralRésumé :
碩士國立高雄大學
資訊管理學系碩士班
106
Unmanned Vehicles (UVs) have been rapidly developed with the benefits of low cost, nearly no geographical restrictions, low risk and immediate response. Using UVs to tracking and sensing targets is very important for monitoring environments and detecting objects. Besides, using UVs equipped with sensors helps to cost down human resource and reduce risks. Positioning UVs location by Global Navigation Satellite System (GNSS) is very helpful for tracking targets. UVs are limited to operating time and flying distance, therefore it is very important to improve UVs’ capability when searching in a huge area. As the result, the aim of this research is to find an uncertain located target by analyzing UV’s track data. Track data is based on UVs’ sensors data and GNSS data to dynamically and immediately detecting target position. This research will propose three programs to tracking the target’s position. Firstly, searching the region which has a higher probability of the target than the other region in a huge area. Continue searching until finding traces of the target. Secondly, getting magnitude and direction of vector by calculating track data to approach the target. Thirdly, narrow down the searching area and search the area more precisely until converge the target’s location. This program will also test the searching efficiency when using different parameter and analyzing the suitability for different situation.
44
« Multiple Radar Target Tracking in Environments with High Noise and Clutter ». Doctoral diss., 2015. http://hdl.handle.net/2286/R.I.29684.
Texte intégralRésumé :
abstract: Tracking a time-varying number of targets is a challenging
dynamic state estimation problem whose complexity is intensified
under low signal-to-noise ratio (SNR) or high clutter conditions.
This is important, for example, when tracking
multiple, closely spaced targets moving in the same direction such as a
convoy of low observable vehicles moving through a forest or multiple
targets moving in a crisscross pattern. The SNR in
these applications is usually low as the reflected signals from
the targets are weak or the noise level is very high.
An effective approach for detecting and tracking a single target
under low SNR conditions is the track-before-detect filter (TBDF)
that uses unthresholded measurements. However, the TBDF has only been used to
track a small fixed number of targets at low SNR.
This work proposes a new multiple target TBDF approach to track a
dynamically varying number of targets under the recursive Bayesian framework.
For a given maximum number of
targets, the state estimates are obtained by estimating the joint
multiple target posterior probability density function under all possible
target
existence combinations. The estimation of the corresponding target existence
combination probabilities and the target existence probabilities are also
derived. A feasible sequential Monte Carlo (SMC) based implementation
algorithm is proposed. The approximation accuracy of the SMC
method with a reduced number of particles is improved by an efficient
proposal density function that partitions the multiple target space into a
single target space.
The proposed multiple target TBDF method is extended to track targets in sea
clutter using highly time-varying radar measurements. A generalized
likelihood function for closely spaced multiple targets in compound Gaussian
sea clutter is derived together with the maximum likelihood estimate of
the model parameters using an iterative fixed point algorithm.
The TBDF performance is improved by proposing a computationally feasible
method to estimate the space-time covariance matrix of rapidly-varying sea
clutter. The method applies the Kronecker product approximation to the
covariance matrix and uses particle filtering to solve the resulting dynamic
state space model formulation.Dissertation/Thesis
Doctoral Dissertation Electrical Engineering 2015
45
« Integrated Waveform-Agile Multi-Modal Track-before-Detect Algorithms for Tracking Low Observable Targets ». Master's thesis, 2012. http://hdl.handle.net/2286/R.I.14953.
Texte intégralRésumé :
abstract: In this thesis, an integrated waveform-agile multi-modal tracking-beforedetect sensing system is investigated and the performance is evaluated using an experimental platform. The sensing system of adapting asymmetric multi-modal sensing operation platforms using radio frequency (RF) radar and electro-optical (EO) sensors allows for integration of complementary information from different sensors. However, there are many challenges to overcome, including tracking low signal-to-noise ratio (SNR) targets, waveform configurations that can optimize tracking performance and statistically dependent measurements. Address some of these challenges, a particle filter (PF) based recursive waveformagile track-before-detect (TBD) algorithm is developed to avoid information loss caused by conventional detection under low SNR environments. Furthermore, a waveform-agile selection technique is integrated into the PF-TBD to allow for adaptive waveform configurations. The embedded exponential family (EEF) approach is used to approximate distributions of parameters of dependent RF and EO measurements and to further improve target detection rate and tracking performance. The performance of the integrated algorithm is evaluated using real data from three experimental scenarios.Dissertation/Thesis
M.S. Electrical Engineering 2012
46
Chakravorty, R. « Novel Bayesian smoothing algorithms for improved track initiation and maintenance in clutter ». Thesis, 2007. http://hdl.handle.net/10453/37706.
Texte intégralRésumé :
University of Technology, Sydney. Faculty of Engineering.Target tracking is a well established field with over fifty years of intense research. While in its core, it deals with estimating targets dynamic states, it is also a critical component of all ” Situation Awareness” and threat assessment systems. These higher layer applications take decisions on important questions like number of targets, positions of them, the instant and position of their initiation, the instant and position of their maneuvers and above all, which of them are threatening and/or friendly. The lower level target tracking algorithms feed the necessary information to these decision taking systems. There are a number of target tracking algorithms to cater for the need of such systems. Most of these available algorithms are based on filtering theory. But it is established that smoothing increases the accuracy of the systems at the expense of a slight lag between the instant of estimation and the instant at which the parameter of interest is being estimated. Hence smoothing is not widely used for practical target tracking applications. However, the situation awareness system is expected to perform better if more precise information is obtained about initiation and termination of the targets along with improved discrimination of true/false targets. This thesis addresses the problem of improved track initiation and maintenance with the smoothing framework to provide better information. It first reviews target tracking and filtering literature. It introduces the concept of random set smoother and derives the IPDA smoother under linear Gaussian assumption. IPDA smoother is also derived by extending the PDA smoother. Finally a theoretical link is established between Random Set smoothing and IPDA smoothing framework. To extend the domain into multiple sensor scenario, the problem of out-of-sequence measurements is also addressed in this thesis under target existence uncertainty. Several realistic scenarios are simulated and the results are verified.
47
Liao, Yi-Shan, et 廖苡珊. « Impact of the targeted dropwindsonde data from DOTSTAR on typhoon track simulations ». Thesis, 2009. http://ndltd.ncl.edu.tw/handle/01992705580733915720.
Texte intégralRésumé :
碩士國立臺灣大學
大氣科學研究所
97
In order to increase the atmospheric observations of typhoons over the ocean region, besides the satellite data, the data from GPS (Global Positioning System) dropwindsonde lunched by the surveillance aircraft are also important. Under the support of the National Science Council (NSC) and Central Weather Bureau (CWB), the synoptic surveillance missions to improve TC track forecasts has been conducted by DOTSTAR (Dropwindsonde Observations for Typhoon Surveillance near the Taiwan Region) in the western North Pacific Ocean since 2003. Four different sensitivity methods have been employed as the guidance to design flight routes and deployment locations of GPS dropwindsondes for the typhoon‘s synoptic surveillance in DOTSTAR.. The two main strategies of the targted observations are ‘around-storm’ and ‘extra-targeted area’. In this research, the impact of dropwindsonde data on typhoon track simulations under different observing strategies is studied. MM5 3DVAR data assimilation system is adopted to assimilate the dropwindsonde data from DOTSTAR during 2004 to 2006, and to asses the statistical impact on typhoon track simulations. It is shown that inclusion of all dropwindsonde data in MM5 3DVAR can effectively reduce the 6 to 72-h track forecast error by about 24%. By only assimilating the around-storm dropwindsonde data, the simulation of typhoon tracks can also be improved. On the contrary, assimilating the extra-targeted dropwindsonde data shows slightly improvement of typhoon track simulation. Typhoon Shanshan (2006) is selected for the case study. Consistent with the results based on the statistics of multiple cases, assimilating all dropwindsonde data can effectively reduce the track forecast error. Overall, the improvement of track by assimilating the extra-targeted dropwindsonde data is more significant than that by assimilating the around-storm dropwindsonde data. Moreover, the combination of around-storm and appropriate extra-targeted dropwindsonde data shows the most track forecast improvement with the northward movement in the later period. Assimilating only half of the around-storm dropwindsonde data shows similar results to the experiments assimilating all around-storm dropwindsonde data. Comparing to the results of assimilating the extra-targeted dropwindsonde data, experiments by assimilating four of the around-storm dropwindsonde data in each quadrant can have more improvement on the track simulations.
48
Chou, Yin-Che, et 周尹喆. « “Search, Track and Kick to Virtual Target Point” of Humanoid Robots by a Neural-Network-Based Active Embedded Vision System ». Thesis, 2012. http://ndltd.ncl.edu.tw/handle/50440456316976544769.
Texte intégralRésumé :
碩士淡江大學
電機工程學系碩士班
100
In this thesis, the Texas Instruments TMS320C6713 digital signal processor, VM480CCD vision module, and the related software (Code Composer Studio), are employed to obtain the “Search, Track and Kick to Virtual Target Point” of humanoid robots by a neural-network-based active embedded vision system. A human machine interface is also designed by an on board computer (i.e., RB-100) to implement a variety of different actions, e.g., walking, turning and kicking, required by the task of penalty kick. The research is accomplished by the integration of the following four parts: the humanoid robot mechanism design and gait planning, the visual image processing for penalty kick, the neural network modeling for searching and positioning, and the strategy of visual navigation of a humanoid robot to execute penalty kick. One of the most important factors for penalty kick is to accurately locate the ball. In this situation, the relation between image plane coordinate and earth coordinate of a ball is modeled by neural network with suitable learning law. First, the CCD module captures the visual image and then sends it to the TMS320C6713 for the corresponding image processing, including binary segmentation, median filter to remove noise, image correction, calculation of ball center. These coordinates of ball and its ground truths are then applied to construct a neural network model between image plane coordinate and earth coordinate. When the humanoid robot is navigated in the vicinity of the ball (e.g., about 10 cm) by the trained neural network model, the visual system starts searching the goal. If it is found, then the posture revision of HR is made for the execution of penalty kick. If it is not found, the ball is kicked, then tracked, and repeated until the goal is found. Finally, the corresponding experiments are arranged to confirm the effectiveness and efficiency of the proposed method.
49
Hu, Chih-Chi, et 胡志祺. « The Sensitivity Analysis of Tropical Cyclone Track and Intensity – from the Aspect of Ensemble Forecast and Targeted Observation ». Thesis, 2018. http://ndltd.ncl.edu.tw/handle/f3fzkd.
Texte intégralRésumé :
碩士國立臺灣大學
大氣科學研究所
106
In this study, the ensemble-based targeted observation technique is adopted to identify the sensitive factors in typhoon track and intensity. This work can be divided into two parts: (1) track sensitivity, and (2) intensity sensitivity. For track sensitivity, we focus on the sensitivity to vorticity perturbations. A new method based on TyPOS (Typhoon-Position-Oriented-Sensitivity) is proposed to investigate the sensitivity for tropical cyclone (TC) binary interaction, i.e., Fengshen and Fungwong (2002). In the original version of TyPOS, there are some mathematical constraints: when the ensemble size is smaller than the number of independent variables in the multiple linear regression model, the Moore-Penrose pseudoinverse gives the solution with an additional constraint, minimum norm, which may not be the correct solution. We redefine the independent variables in the new method, allowing these variables to better represent the weather system, which can also reduce the number of independent variables. In addition, we also utilize a new sampling strategy, which involves the perturbations based on the background error covariance from National Centers for Environment Prediction, and different TC sizes by TC bogus method, to generate the ensemble. The results show that, in the beginning, the vorticity perturbations surrounding around 500-800 km of the initial TC position are the most sensitive for both TCs, which is related to the barotropic instability occurring near the outer region of TC where the vorticity gradient changes signs. At a later time, the main factor controlling the movement of Fengshen is the strength of subtropical high, while the size of Fungwong also plays a minor role. The factors controlling the movement of Fungwong include the perturbations in the western part of the monsoon trough, the size of Fengshen, and the perturbations located between two TCs. For the interaction between two TCs, Fengshen (with larger size) has a larger impact on Fungwong (with smaller size); the environment perturbations can change the relative location of two TCs, which can also change the effect of binary interaction. For intensity sensitivity, we simulate the storm in an idealized environment condition. The partial correlation is adopted to find the correlation between several variables and the TC intensification rate under the same TC intensity. The results show that the larger intensification rate is positively correlated with stronger secondary circulation, larger inertial stability, larger equivalent potential temperature in 1-3 times of the radius of the maximum wind (RMW), below 2 km (called sensitive region), and larger latent heat release and ice mixing ratio in the eyewall region in mid-to-upper troposphere. The partial correlation between equivalent potential temperature and intensification rate in the sensitive region is about 0.7, which is the largest among all the variables. Further analysis shows that larger equivalent potential temperature in the sensitive region can cause larger conditional instability, and hence larger vertical velocity in the eyewall region. The air with larger vertical velocity can release more latent heat and bring larger absolute angular momentum to the inner core in the mid-to-upper troposphere, which in turn increases the inertial stability and heating efficiency. The larger latent heat along with the increasing heating efficiency helps TC to develop the warm core, and to reduce the minimum sea level pressure. We also find that strength of the mid-level inflow is positively correlated with the strength of secondary circulation. From the results of water vapor transport and trajectory analysis, stronger mid-level inflow may bring low equivalent potential temperature air into the boundary inflow layer, which can reduce the equivalent potential temperature in the sensitive region. The development of the outer rainbands also plays a role in reducing the equivalent potential temperature in the sensitive area.
50
Elhoshy, Mostafa Kamal Kamel. « Signal processing techniques for modern radar systems ». Thesis, 2019. http://hdl.handle.net/1828/11025.
Texte intégralRésumé :
This dissertation considers radar detection and tracking of weak fluctuating targets
using dynamic programming (DP) based track-before-detect (TBD). TBD combines target
detection and tracking by integrating data over consecutive scans before making a decision
on the presence of a target. A novel algorithm is proposed which employs order statistics in
dynamic programming based TBD (OS-DP-TBD) to detect weak fluctuating targets. The
well-known Swerling type 0, 1 and 3 targets are considered with non-Gaussian distributed
clutter and complex Gaussian noise. The clutter is modeled using the Weibull, K and
G0 distributions. The proposed algorithm is shown to provide better performance than
well-known techniques in the literature. In addition, a novel expanding window multiframe
(EW-TBD) technique is presented to improve the detection performance with reasonable
computational complexity compared to batch processing. It is shown that EW-TBD has
lower complexity than existing multiframe processing techniques. Simulation results are
presented which confirm the superiority of the proposed expanding window technique in
detecting targets even when they are not present in every scan in the window. Further, the
throughput of the proposed technique is higher than with batch processing. Depending
on the range and azimuth resolution of the radar system, the target may appear as a point
in some radar systems and there will be target energy spillover in other systems. This
dissertation considers both extended targets with different energy spillover levels and point
targets. Simulation results are presented which confirm the superiority of the proposed
algorithm in both cases.Graduate