Dissertations / Theses on the topic 'Poinine'
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1
Faisal, Farhan. "Query-by-Pointing: Algorithms and Pointing Error Compensation." Fogler Library, University of Maine, 2003. http://www.library.umaine.edu/theses/pdf/FaisalF2003.pdf.
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Vigil, Jeannine S. "NON-GIMBALED ANTENNA POINTING." International Foundation for Telemetering, 1997. http://hdl.handle.net/10150/609751.
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International Telemetering Conference Proceedings / October 27-30, 1997 / Riviera Hotel and Convention Center, Las Vegas, NevadaThis paper details the interaction of a small satellite with a space network and estimates the number of contacts and duration of contacts between the small, spin-stabilized satellite and a TDRS satellite. The simulations were performed using Satellite Tool Kit (STK) version 3.0, an orbital analysis software program. STK was configured for the four vehicles representing the spin-stabilized satellite and three TDRS satellites, TDRS East, West, and TDRS Zone of Exclusion. A set of simulations were run in which the spinstabilized satellite was given orbital elements corresponding to an orbital altitude between 600 km and 1200 km. The orbital inclination angle for the set of simulations was also varied from 20° through 100° along with the antenna cone angle of 10° through 40° to account for the effective beamwidths. In each of the simulations, the access to each TDRS satellite in the SN constellation was examined as a function of orbital altitude, orbital inclination angle, and antenna cone angle.
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Sands, Timothy A. "Fine pointing of military spacecraft." Monterey, Calif. : Naval Postgraduate School, 2007. http://bosun.nps.edu/uhtbin/hyperion.exe/07Mar%5FSands%5FPhD.pdf.
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Dissertation (Ph.D. in Astronautical Engineering)--Naval Postgraduate School, March 2007.Dissertation Advisor(s): Brij N. Agrawal. "March 2007." Includes bibliographical references. Also available in print.
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Wood, Avery. "Copper Weathervane Pointing Nowhere: Poems." Honors in the Major Thesis, University of Central Florida, 2005. http://digital.library.ucf.edu/cdm/ref/collection/ETH/id/815.
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This item is only available in print in the UCF Libraries. If this is your Honors Thesis, you can help us make it available online for use by researchers around the world by following the instructions on the distribution consent form at http://library.ucfBachelors
Arts and Sciences
English; Creative Writing
5
Myers, Edward. "It's like pointing a finger." The Ohio State University, 1994. http://rave.ohiolink.edu/etdc/view?acc_num=osu1322065756.
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Grünloh, Thomas, and Ulf Liszkowski. "Prelinguistic vocalizations distinguish pointing acts." Cambridge University Press, 2015. https://tud.qucosa.de/id/qucosa%3A39052.
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The current study investigated whether point-accompanying characteristics, like vocalizations and hand shape, differentiate infants’ underlying motives of prelinguistic pointing. We elicited imperative (requestive) and declarative (expressive and informative) pointing acts in experimentally controlled situations, and analyzed accompanying characteristics. Experiment 1 revealed that prosodic characteristics of point-accompanying vocalizations distinguished requestive from both expressive and informative pointing acts, with little differences between the latter two. In addition, requestive points were more often realized with the whole hand than the index finger, while this was the opposite for expressive and informative acts. Experiment 2 replicated Experiment 1, revealing distinct prosodic characteristics for requestive pointing also when the referent was distal and when it had an index-finger shape. Findings reveal that beyond the social context, point-accompanying vocalizations give clues to infants’ underlying intentions when pointing.
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Bishop, Ronald Michael. "Development of precision pointing controllers with and without vibration suppression for the NPS precision pointing hexapod." Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 2002. http://library.nps.navy.mil/uhtbin/hyperion-image/02Dec%5FBishop.pdf.
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Thesis (Aeronautical and Astronautical Engineer Degree and M.S. in Astronautical Engineering)--Naval Postgraduate School, December 2002.Thesis advisor(s): Brij Agrawal, Hong-Jen Chen. Includes bibliographical references (p. 85-88). Also available online.
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Feldgoise, Stephan Jay. "Pointing acquisition and stabilization test bed." Thesis, Massachusetts Institute of Technology, 1993. http://hdl.handle.net/1721.1/82747.
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Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1993.Includes bibliographical references (leaf 84).
by Stephan Jay Feldgoise.
M.S.
9
Kopper, Regis Augusto Poli. "Understanding and Improving Distal Pointing Interaction." Diss., Virginia Tech, 2011. http://hdl.handle.net/10919/28183.
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Distal pointing is the interaction style defined by directly pointing at targets from a distance. It follows a laser pointer metaphor and the position of the cursor is determined by the intersection of a vector extending the pointing device with the display surface. Distal pointing as a basic interaction style poses several challenges for the user, mainly because of the lack of precision humans have when using it.
The focus of this thesis is to understand and improve distal pointing, making it a viable interaction metaphor to be used in a wide variety of applications. We achieve this by proposing and validating a predictive model of distal pointing that is inspired by Fitts' law, but which contains some unique features. The difficulty of a distal pointing task is best described by the angular size of the target and the angular distance that the cursor needs to go across to reach the target from the input device perspective. The practical impact of this is that the user's relative position to the target should be taken into account. Based on the model we derived, we proposed a set of design guidelines for high-precision distal pointing techniques. The main guideline from the model is that increasing the target size is much more important than reducing the distance to the target.
In order to improve distal pointing, we followed the model guidelines and designed interaction techniques that aim at improving the precision of distal pointing tasks. Absolute and Relative Mapping (ARM) distal pointing increases precision by offering the user a toggle which changes the control/display (CD) ratio such that a large movement of the input device is mapped to a small movement of the cursor. Dynamic Control Display Ratio (DyCoDiR) automatically increases distal pointing precision, as the user needs it. DyCoDiR takes into account the user distance to the interaction area and the speed at which the user moves the input device to dynamically calculate an increased CD ratio, making the action more precise the steadier the user tries to be. We performed an evaluation of ARM and DyCoDiR comparing them to basic distal pointing in a realistic context. In this experiment, we also provided variations of the techniques which increased the visual perception of targets through zooming in the area around the cursor when precision was needed. Results from the study show that ARM and DyCoDiR are significantly faster and more accurate than basic distal pointing with tasks that require very high precision. We analyzed user navigation strategies and found that the high precision techniques afford users to remain stationary while performing interactions. However, we also found that individual differences have a strong impact on the decision to walk or not, and that, sometimes, is more important than the technique affordance. We provided a validation for the distal pointing model through the analysis of expected difficulty of distal pointing tasks in light of each technique tested.
We propose selection by progressive refinement, a new design concept for distal pointing selection techniques, whose goal is to offer the ability to achieve near perfect accuracy in selection at very cluttered environments. The idea of selection by progressive refinement is to gradually eliminate possible targets from the set of selectable objects until only one object is available for selection. We implemented SQUAD, a selection by progressive refinement distal pointing technique, and performed a controlled experiment comparing it to basic distal pointing. We found that there is a clear tradeoff between immediate selections that require high precision and selections by progressive refinement which always require low precision. We validated the model by fitting the distal pointing data and proposed a new model, which has a linear growth in time, for SQUAD selection.Ph. D.
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Hatzopoulou, Marianna. "Acquisition of reference to self and others in Greek Sign Language : From pointing gesture to pronominal pointing signs." Doctoral thesis, Stockholm : Sign Language Section, Department of Linguistics, Stockholm University, 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-8293.
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Kranstedt, Alfred, Andy Lücking, Thies Pfeiffer, Hannes Rieser, and Marc Staudacher. "Measuring and reconstructing pointing in visual contexts." Universität Potsdam, 2006. http://opus.kobv.de/ubp/volltexte/2006/1036/.
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We describe an experiment to gather original
data on geometrical aspects of pointing.
In particular, we are focusing upon
the concept of the pointing cone, a geometrical
model of a pointing’s extension.
In our setting we employed methodological
and technical procedures of a new type
to integrate data from annotations as well
as from tracker recordings. We combined
exact information on position and orientation
with rater’s classifications. Our first
results seem to challenge classical linguistic
and philosophical theories of demonstration
in that they advise to separate
pointings from reference.
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Copley, Charles Judd. "Temperature dependence of the HartRAO pointing model." Thesis, Rhodes University, 2008. http://hdl.handle.net/10962/d1005277.
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This thesis investigates control aspects of the Hartebeeshoek Radio Astronomy Observatory (HartRAO) antenna. The installation of a new 22 GHz receiver has required the pointing accuracy to be improved to less than 4 mdeg. The effect of thermal conditions on the the HartRAO antenna pointing offset is investigated using a variety of modelling techniques including simple geometric modelling, neural networks and Principal Component Analysis (PCA). Convincing results were obtained for the Declination pointing offset, where applying certain model predictions to observations resulted in an improvement in Declination pointing offset from 5.5 mdeg to 3.2 mdeg (≈50%). The Right Ascension pointing model was considerably less convincing with an improvement of approximately from 5.5 mdeg to 4.5 mdeg (≈20%) in the Right Ascension pointing offset. The Declination pointing offset can be modelled sufficiently well to reduce the pointing offset to less than 4 mdeg, however further investigation of the underlying causes is required for the Right Ascension pointing offset.
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Nugent, Susie P. "Infant cross-fostered chimpanzees develop indexical pointing." abstract and full text PDF (free order & download UNR users only), 2006. http://0-gateway.proquest.com.innopac.library.unr.edu/openurl?url_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&res_dat=xri:pqdiss&rft_dat=xri:pqdiss:1433288.
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Jacobson, Craig. "INTERNATIONAL SPACE STATION REMOTE SENSING POINTING ANALYSIS." Master's thesis, University of Central Florida, 2005. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/3308.
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This paper analyzes the geometric and disturbance aspects of utilizing the International Space Station for remote sensing of earth targets. The proposed instrument is SHORE (Station High-Sensitivity Ocean Research Experiment), a multi-band optical spectrometer with 15 m pixel resolution. The analysis investigates the contribution of the error effects to the quality of data collected by the instrument. The analysis begins with the discussion of the coordinate systems involved and then conversion from the target coordinate system to the instrument coordinate system. Next the geometry of remote observations from the Space Station is investigated including the effects of the instrument location in Space Station and the effects of the line of sight to the target. The disturbance and error environment on Space Station is discussed covering factors contributing to drift and jitter, accuracy of pointing data and target and instrument accuracies. Finally, there is a brief discussion of image processing to address any post error correction options.M.S.A.E.
Department of Mechanical, Materials and Aerospace Engineering;
Engineering and Computer Science
Aerospace Engineering
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Zhuang, Jie. "Array signal processing robust to pointing errors." Thesis, Imperial College London, 2011. http://hdl.handle.net/10044/1/6850.
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The objective of this thesis is to design computationally efficient DOA (direction-of- arrival) estimation algorithms and beamformers robust to pointing errors, by harnessing the antenna geometrical information and received signals. Initially, two fast root-MUSIC-type DOA estimation algorithms are developed, which can be applied in arbitrary arrays. Instead of computing all roots, the first proposed iterative algorithm calculates the wanted roots only. The second IDFT-based method obtains the DOAs by scanning a few circles in parallel and thus the rooting is avoided. Both proposed algorithms, with less computational burden, have the asymptotically similar performance to the extended root-MUSIC. The second main contribution in this thesis is concerned with the matched direction beamformer (MDB), without using the interference subspace. The manifold vector of the desired signal is modeled as a vector lying in a known linear subspace, but the associated linear combination vector is otherwise unknown due to pointing errors. This vector can be found by computing the principal eigen-vector of a certain rank-one matrix. Then a MDB is constructed which is robust to both pointing errors and overestimation of the signal subspace dimension. Finally, an interference cancellation beamformer robust to pointing errors is considered. By means of vector space projections, much of the pointing error can be eliminated. A one-step power estimation is derived by using the theory of covariance fitting. Then an estimate-and-subtract interference canceller beamformer is proposed, in which the power inversion problem is avoided and the interferences can be cancelled completely.
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Eisemann, David W. "Methods for determining dish antenna pointing angles." Master's thesis, This resource online, 1992. http://scholar.lib.vt.edu/theses/available/etd-03302010-020248/.
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Hospodar, Edward J. "A laser metrology system for precision pointing." Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 2003. http://library.nps.navy.mil/uhtbin/hyperion-image/03Dec%5FHospodar.pdf.
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Thesis (M.S. in Astronautical Engineering)--Naval Postgraduate School, December 2003.Thesis advisor(s): Brij N. Agrawal, Hong-Jen Chen. Includes bibliographical references (p. 63). Also available online.
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Christensen, Randall S. "Linear Covariance Analysis For Gimbaled Pointing Systems." DigitalCommons@USU, 2013. https://digitalcommons.usu.edu/etd/1766.
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Linear covariance analysis has been utilized in a wide variety of applications. Historically, the theory has made significant contributions to navigation system design and analysis. More recently, the theory has been extended to capture the combined effect of navigation errors and closed-loop control on the performance of the system. These advancements have made possible rapid analysis and comprehensive trade studies of complicated systems ranging from autonomous rendezvous to vehicle ascent trajectory analysis. Comprehensive trade studies are also needed in the area of gimbaled pointing systems where the information needs are different from previous applications. It is therefore the objective of this research to extend the capabilities of linear covariance theory to analyze the closed-loop navigation and control of a gimbaled pointing system. The extensions developed in this research include modifying the linear covariance equations to accommodate a wider variety of controllers. This enables the analysis of controllers common to gimbaled pointing systems, with internal states and associated dynamics as well as actuator command filtering and auxiliary controller measurements. The second extension is the extraction of power spectral density estimates from information available in linear covariance analysis. This information is especially important to gimbaled pointing systems where not just the variance but also the spectrum of the pointing error impacts the performance. The extended theory is applied to a model of a gimbaled pointing system which includes both flexible and rigid body elements as well as input disturbances, sensor errors, and actuator errors. The results of the analysis are validated by direct comparison to a Monte Carlo-based analysis approach. Once the developed linear covariance theory is validated, analysis techniques that are often prohibitory with Monte Carlo analysis are used to gain further insight into the system. These include the creation of conventional error budgets through sensitivity analysis and a new analysis approach that combines sensitivity analysis with power spectral density estimation. This new approach resolves not only the contribution of a particular error source, but also the spectrum of its contribution to the total error. In summary, the objective of this dissertation is to increase the utility of linear covariance analysis for systems with a wide variety of controllers and for whom the spectrum of the errors is critical to performance.
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Jonsson, Lisa. "Simulations of Satellite Attitude Maneuvers : Detumbling and Pointing." Thesis, Luleå tekniska universitet, Rymdteknik, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-73285.
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Hughes, Steven Patrick. "Formation Flying Performance Measures for Earth Pointing Missions." Thesis, Virginia Tech, 1999. http://hdl.handle.net/10919/36483.
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Clusters of low-performance spacecraft flying in formation may
provide enhanced performance over single high-performance
spacecraft. This is especially true for remote sensing missions
where interferometry or stereographic imaging may provide higher
resolution data. The configurations of such formations vary
during an orbit due to orbital dynamics, and over longer time
scales due to perturbations. Selection of a configuration should
be based on overall performance of the formation. In this thesis,
performance measures are developed and evaluated based on
integration over one orbit. The measures involve the angular
separation of spacecraft, the distance between spacecraft, and an
area-based measure of the separation of the spacecraft. Numerical
techniques are employed to evaluate the performance measures to
determine optimal scenarios for two formations. Simplifying
assumptions are made to allow a closed-form analytic solution and
the results are compared to those obtained numerically. Finally,
the sensitivity of the measures to linearized propagation
techniques is investigated.Master of Science
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Douglas, Lisa J. "Measuring Configural Spatial Knowledge with Alternative Pointing Judgments." Wright State University / OhioLINK, 2008. http://rave.ohiolink.edu/etdc/view?acc_num=wright1200339961.
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Sanfedino, Francesco. "Experimental validation of a high accuracy pointing system." Thesis, Toulouse, ISAE, 2019. http://www.theses.fr/2019ESAE0009/document.
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Dans la quasi-totalité des missions d'observation de la Terre requérant une grande précision de pointage, les micro-vibrations sont le principal élément dégradant les performances de pointage. Les principales sources de micro-perturbations sont les roues et, lorsqu'il y en a, les refroidisseurs cryogéniques. D’autres sources de perturbations sont les propulseurs chimiques, les moteurs pas à pas de l'antenne solaire, les mécanismes d'entraînement,… L'objectif de cette thèse (NPI) est de concevoir et de valider un système de pointage actif de haute précision à base d’actionneurs piézoélectriques capable de rejeter les micro-vibrations au niveau d’un miroir, avec des pénalités de masse et de puissance contrôlées. Les caractéristiques attendues de ce système sont : • une grande bande passante en boucle fermée : typiquement jusqu'à 100 Hz • une faible erreur résiduelle: typiquement inférieure à 50-100 rad (ordre de grandeur approximatif) • un encombrement et une masse faibles (à quantifier au cours de la thèse) • une puissance requise minimale (à optimiser au cours de la thèse) • la modularité • une possible évolution Ce sujet est fortement pluridisciplinaire (mécanique, automatique, optique et instrumentation). Les défis scientifiques de la thèse sont : • la conception d’un système de pointage actif à bande passante élevée avec impact de masse et de volume faible et une puissance requise à minimiser • la commande robuste du système de pointage actif permettant de rejeter des micro-perturbations dont le spectre varie en fonction des phases de la mission • la tenue des performances en précision • la définition d'une méthodologie générique de conception intégrée applicable à d'autres systèmes de pointage (plusieurs degrés de liberté, ...)On almost all high accuracy pointing Science and Earth observation missions, micro-vibrations are the major contributor to pointing performances degradations (RPE). The main sources of micro-disturbances being the wheels and, when present, the cry-coolers. Other disturbance sources may originate from chemical thrusters, antenna stepper motors, Solar Array Drive Mechanisms (SADM), antenna trimming mechanisms, or payload mechanisms set either inside the sensitive payload, or inside another payload of the same spacecraft. The objective of this NPI is to investigate and validate a high accuracy active pointing system able to reject micro-vibrations at instrument level: • large control bandwidth : typically up to 100Hz • low residual error : typically lower than 50-100nrad (rough order magnitude to be further defined in the frame of this NPI) • low mass and volume impacts • scalable • modular This subject is strongly multidisciplinary (mechanics, control theory, optics and instrumentation). The scientific challenges of the thesis are: • the design of an active pointing system with high bandwidth, low impact of mass and volume and minimized power • the robust control of the active pointing system allowing to reject micro-disturbances whose spectrum varies according to the phases of the mission • obtaining high accuracy performances • the definition of a generic methodology of integrated design applicable to other pointing systems (several degrees of freedom e.g.)
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Davy, Jean-Marc. "Les torsades de pointe medicamenteuses : modes d'initiation." Paris 6, 1991. http://www.theses.fr/1991PA066456.
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Grace aux etudes cliniques, les divers facteurs favorisants et declenchants des torsades de pointe medicamenteuses ont ete progressivement reconnus. Ces modes d'initiation ont pu etre analyses sur un modele de torsades de pointe developpe chez le chien conscient, en bloc auriculo-ventriculaire et recevant des medicaments comme la quinidine ou le sotalol. Huit travaux constituent ce memoire. Les memes facteurs favorisants ont ete retrouves et sont decrits en premiere partie: facteurs pharmacologiques (posologie et duree d'administration), biologiques (hypokaliemie) et electrophysiologiques (degre et surtout duree de la bradycardie). En deuxieme partie, les facteurs declenchants ont ete etudies, avec l'influence du systeme nerveux adrenergique, certaine mais difficile a analyser directement, et le role d'un brusque raccourcissement des cycles, par extrasystoles ou breves salves, qui est apparu plus critique que celui des pauses ventriculaires. L'etude des mecanismes en cause, reentree ou post-depolarisations cellulaires, constitue la troisieme partie. Des enregistrements de potentiels d'action monophasiques ventriculaires au cours d'acces de torsades de pointe ont donc ete realises, ainsi qu'un essai de cartographie chez le chien anesthesie
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Leiva, Germán. "Gaze-supported pointing devices for day-to-day computerinteraction." Thesis, KTH, Skolan för informations- och kommunikationsteknik (ICT), 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-174853.
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In this work we assess four prototypes of gaze-supported input devices that aim o be more ergonomic alternatives than the mouse and touchpads for day to day omputer usage. These prototypes (nunchuck, ring, smartphone and trackball)have hree properties. First, they enable a distant interaction from the computer, letting he user have a 135-degree body-thigh sitting posture. Second, they allow one-handed nteractions, a convenient setting for people that can only use one hand due to rgonomic complications in the other one. And last, they are based on familiar nput technologies and conventions, so users can easily learn how to use them. An xperiment on pointing and drag & drop tasks was conducted to evaluate quantitative roperties of the devices and get qualitative user feedback. The smartphone ranked first n almost all the user feedback entries. The measures of speed and accuracy presented everal outliers. According to the measured results, the smartphone was the fastest ointing device and the most accurate for every task; the trackball was the fastest evice for drag & drop tasks. The nunchuck ranked last in all the measures. Based on his study, future work should be conducted on improving the design of the companion evices based on multitouch and trackball technologies.
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Barba, Victor. "Controller design for accurate antenna pointing onboard a spacecraft." Wright-Patterson AFB, Ohio : Air Force Institute of Technology, 2007. http://handle.dtic.mil/100.2/ADA471066.
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Thesis (M.S.)--Air Force Institute of Technology, 2007."June 2007." "In partial fulfillment of the requirements for the degree of Master of Science in Aeronautical Engineering."--P. [ii]. Vita. Title from cover page of PDF file (viewed: May 8, 2008).
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Ho, Lap. "High precision short-baseline pointing system using GPS interferometry." Ohio : Ohio University, 1995. http://www.ohiolink.edu/etd/view.cgi?ohiou1179435242.
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de, Grosbois John P. "Visual interaction with ambiguous edges : perception, pointing and prehension." Thesis, University of British Columbia, 2012. http://hdl.handle.net/2429/40166.
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The current investigation examined perceptual and movement responses to evaluate the possibility of unique representations guiding the outcomes of perceptual and motor-based responses. In two experiments the quality of visual luminance edges was manipulated and the outcomes of three visually based tasks, namely perceptual estimates, pointing, and prehensile/grasping movements were measured. The findings provided evidence for the use of unique representations of stimulus features that are task specific.
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Nilsson, Daniel. "Characterization of the pointing systems of the PoGOLite Pathfinder." Thesis, KTH, Fysik, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-123822.
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Côté, Chantal. "Detection of supercooled drizzle by a vertically pointing radar." Thesis, McGill University, 2002. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=33740.
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The objective of this study is to detect zones of supercooled drizzle using data from a vertically pointing radar (VPR). This radar was used in the AIRS (Alliance Icing Research Study) experiment held at Mirabel Airport from November 1999 to February 2000.For cases where conditions favor the formation of drizzle drops with a diameter sufficiently large, a second mode with a distinct speed and reflectivity can be separated from that received from snow. That the second mode corresponds to supercooled drizzle is verified by comparing reflectivities and speeds with aircraft data taken during AIRS.
For cases without bimodality, regions of icing may be localized by a computation of the mass flux gradient. Accretion of supercooled water on snow (riming) increases both its density and fall speed. Thus, a sudden increase in snow fall speed indicates the presence of supercooled water.
A conceptual model describing necessary conditions for the formation of supercooled drizzle is proposed. This model is based on the analysis of a synoptic situation present for two days of intense icing.
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Campos, Ortega Edwin F. 1972. "Analyses of precipitation signal using VHF vertically-pointing radar." Thesis, McGill University, 2006. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=102965.
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In addition to a proper radar calibration, quantitative estimation of precipitation from VHF radars requires the extraction of the precipitation signal out of the Doppler spectra. It also requires the proper conversion of this precipitation signal into a reflectivity factor.This research develops a multi-faceted approach for the calibration of VHF vertically-pointing radars, by combining a first calibration method that compares the recorded VHF signal to power coming from a noise generator and a second calibration method that compares recorded VHF signal to cosmic radiation. This approach allows the retrieval of antenna and receiver parameters (such as noise levels, efficiency, and gain), and four other equations for the corresponding errors. In addition, we develop an equation for calibrating Doppler spectra.
The analysis is focused on rain observations with VHF radar. We verify the hypothesis that |K|2 = 0.93 for most of the rain observations at VHF band. A signal-processing algorithm for extracting the rain signal out of the VHF power spectra is then presented. This work also derives a general version of the radar equation valid for vertically pointing radars, as well as a particular version of this equation valid for the McGill VHF radar. The study then makes numerical simulations of several profiles of precipitation signal at VHF band, by combining high-resolution profiles of precipitation signal (from a calibrated X-band radar) and the VHF antenna pattern in our general version of the radar equation. The analyses indicate that VHF reflectivity at gates above the melting layer is artificially enhanced by the precipitation signal collected from the side lobes.
This work also studies the effect of precipitation in the scattering properties of clear air. We analyze several cases of stratiform and convective rain, occurring in a continental mid-latitude environment (Montreal, Lat.45.41°N, Long.73.94°W). For these cases, Doppler spectra taken by a VHF vertically-pointing radar were used to retrieve simultaneous co-located values of precipitation intensity (rainrates) and degrees of refractive index fluctuation (structure-function parameter for refractivity turbulence, Cn2). We validated these retrievals using co-located, calibrated measurements of precipitation signal at X-band. The comparison between equivalent reflectivity factors at X and VHF bands agrees within 1 dB. The study includes rainrates between 0.3 and 78 mm/h, and Cn2 values between 10-16 and 10-12 m-2/3 , retrieved from the VHF spectra at 2.5 km height. The study finds that the occurrence of rain is associated with distinctive changes in the structure of air refractive index fluctuations, and that these changes are of a turbulent nature for the most intense rainrates.
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Fabry, Frédéric. "Precipitation estimates by radar : a zenith pointing radar perspective." Thesis, McGill University, 1990. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=59887.
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Data collected from zenith pointing radar is used to study the range dependence of some meteorological radar errors associated with different sampling methods between radar and gauges in stratiform precipitation. Errors due to the vertical variation of reflectivity such as those related with the bright band or with snow growth cause a much larger bias in radar estimates than those due to beam filling or gradients. The maximum useful range varies with the bright band height and the elevation angle program used, a CAPPI giving superior results especially for snow. The sudden changes in bright band height over short distances and the large scatter of its thickness limit the accuracy of current corrections for the vertical variation of reflectivity based on scanning radar data. The possibility of using a zenith pointing radar to obtain this correction is discussed.
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O'Neill, Michael Gregory. "Assessing the impacts of fractionation on pointing-intensive spacecraft." Thesis, Massachusetts Institute of Technology, 2009. http://hdl.handle.net/1721.1/58389.
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Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Aeronautics and Astronautics, February 2010.Cataloged from PDF version of thesis.
Includes bibliographical references (p. 165-168).
Fractionated spacecraft consist of physically independent, "free-flying" modules composed of various subsystems. Thus, a fractionated spacecraft might consist of one-module responsible for the power generation and storage, another module responsible for the communications and computing, another module responsible for the attitude and guidance determination, another module responsible for the payload, and so on. Fractionated spacecraft are of particular interest for pointing-intensive, remote sensing mission spacecraft because of their ability to physically decouple subsystems and payloads that truly need precise pointing, thereby potentially reducing the lifecycle cost of fractionated spacecraft relative to a comparable monolithic spacecraft, for a given space mission. Additionally, using fractionation to decouple pointing-intensive subsystems and payloads may potentially reduce the mass and size of the module containing the payload in a fractionated spacecraft (i.e., Payload Module) relative to that of a comparable monolithic spacecraft. If fractionated spacecraft prove to reduce the mass and size associated with the Payload Module, for a given pointing-intensive, remote sensing mission, it may enable pointing-intensive fractionated spacecraft to have longer space mission lifetimes than comparable monolithic spacecraft.
(cont.) This research seeks to quantitatively assess the impacts of various fractionated spacecraft architecture strategies on the lifecycle cost, mass, propellant usage, and mission lifetime of pointing-intensive, remote sensing mission spacecraft. A dynamic lifecycle simulation and parametric model was used to assess the lifecycle cost impacts, while the mass, propellant usage, and mission lifetime impacts were assessed using a non-parametric, physics-based computer model. Results from the research demonstrate that fractionated spacecraft can be both more and less expensive than a comparable monolithic spacecraft performing the same space mission. Additionally, the results show that due to the ability of fractionated spacecraft to decouple subsystems and payloads that truly need precise pointing, the mass and propellant usage of the Payload Module can be appreciably less than that of a comparable monolithic spacecraft. Subsequently, fractionated spacecraft can attain longer mission lifetimes than a monolithic spacecraft, and in certain instances, do so with a lesser lifecycle cost than the monolith at its respective shorter mission lifetime.
by Michael Gregory O'Neill.
S.M.
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Pointner, Benedikt [Verfasser]. "Zytotoxische und Enzym-biochemische Untersuchungen von Pyrrolidinderivaten / Benedikt Pointner." Tübingen : Universitätsbibliothek Tübingen, 2020. http://d-nb.info/1219903728/34.
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Shim, Yohan. "Topology control and pointing in free space optical networks." College Park, Md.: University of Maryland, 2007. http://hdl.handle.net/1903/7773.
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Thesis (Ph. D.) -- University of Maryland, College Park, 2007.Thesis research directed by: Dept. of Civil and Environmental Engineering . Title from t.p. of PDF. Includes bibliographical references. Published by UMI Dissertation Services, Ann Arbor, Mich. Also available in paper.
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Wu, Zhen. "The role of pointing gestures in facilitating word learning." Diss., University of Iowa, 2015. https://ir.uiowa.edu/etd/1805.
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Previous natural observations have found a robust correlation between infants’ spontaneous gesture production and vocabulary development: the onset and frequency of infants’ pointing gestures are significantly correlated to their subsequent vocabulary size (Colonnesi, Stams, Koster, & Noom, 2010). The present study first examined the correlations between pointing and vocabulary size in an experimental setting, and then experimentally manipulated responses to pointing, to investigate the role of pointing in infants’ forming word-object associations.
In the first experiment, we elicited 12- to 24-month old infants’ pointing gestures to 8 familiar and 8 novel objects. Their vocabulary was assessed by the MacArthur Communicative Development Inventory (MCDI): Words and Gestures. Results showed that 12-16 month old infants’ receptive vocabulary was positively correlated to infants’ spontaneous pointing. This correlation, however, was not significant in 19-24 month old infants. This experiment thus generalizes the previous naturalistic observation findings to an experimental setting, and shows a developmental change in the relation between pointing and receptive vocabulary. Together with prior studies, it suggests a possible positive social feedback loop of pointing and language skills in infants younger than 18 months old: the bigger vocabulary size infants have, the more likely they point, the more words they hear, and then the faster they develop their vocabulary.
In the second experiment, we tested whether 16-month-old infants’ pointing gestures facilitate infants’ word learning in the moment. Infants were randomly assigned to one of three conditions: the experimenter labeled an unfamiliar object with a novel name 1) immediately after the infant pointed to it (the point contingent condition); 2) when the infant looked at it; or 3) at a schedule predetermined by a vocabulary-matched infant in the point contingent condition. After hearing the objects’ names, infants were presented with a word learning test. Results showed that infants successfully selected the correct referent above chance level only in the point contingent condition, and their performance was significantly better in the point contingent condition than the other two conditions. Therefore, only words that were provided contingently after pointing were learned. Taken together, these two studies further our understanding of the correlation between early gesture and vocabulary development and suggest that pointing plays a role in early word learning.
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Delaplace, Marie. "L'emergence des activites de haute technologie dans l'espace economique mondial : cadre theorique et application a l'industrie de la construction informatique." Reims, 1994. http://www.theses.fr/1994REIME001.
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La localisation des activites de haute technologie fait l'objet d'une abondante litterature. Cette derniere tend a montrer que ces activites s'implanteraient dans de nouveaux espaces de production. Cependant, en raison d'une insuffisante conceptualisation de la haute technologie, il est extremement difficile d'identifier quels seraient leurs caracteristiques precises et leurs processus de localisation. L'objectif de cette these est donc de proposer un cadre theorique qui permette d'apprehender l'emergence differenciee de ces activites dans l'espace economique mondial. Apres les avoir definies comme des activites qui emergent suite a l'apparition de nouveaux paradigmes qui presentent la specificite d'etre fondes sur des avancees de la science, nous montrons qu'une identification des firmes qui penetrent dans ces activites ne peut se faire independamment de la prise en compte de leurs contextes nationaux : les structures industrielles emergentes dans les differents pays divergent. Puis nous mettons en evidence que les differents types de firmes, qui sont soumis a des contraintes organisationnelles differenciees, ont des comportements de localisation eux aussi heterogenes. Des lors, la distribution spatiale d'une activite de haute technologie dans un espace intranational est pour partie le produit differencie de son emergence dans les differents paysThe location of high technology activities is the subject of a voluminous literature. This latter tends to show that these activities would located themselves in new spaces of production. But, in view of an inadequate conceptualization of high technology, it is extremely difficult to identify what their precise characteristics and their processes of location would be. The aim of this thesis is therefore to provide a theoretical framework which allows us to understand the differentiated emergence of high technology activities in the world economic space. After defining them as activites which emerge with the appearance of new technological paradigms which present the specificity to be based on the progress science, we show that an identification of firms which enter into these activities can't be done without taking into consideration their national context : the emerging industrial structures within the different countries diverge. Then we emphasize that the different types of firms, which are subject to differentiated organizational contraints, also have a heterogeneous locating behaviour. The spatial distribution of a high technology activity in an intranational space is therefore in part the product of the differenciated conditions of its emergence in the different countries. The emergence of the computer industry in the united states, great-britain and
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Christodoulou, Marilena. "Developing a parametric system for pointe shoe customization." Doctoral thesis, Universitat Politècnica de Catalunya, 2021. http://hdl.handle.net/10803/673859.
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A Pointe Shoe is worn by ballet dancers while performing “en pointe”. This fundamental ballet technique, which is performed by rising to the tips of the toes, enables dancers to create the illusion of incredible lightness and sylph-like appearance. However, pointe work causes pain, blisters, calluses, and disfigurement of the feet. Dancers, pointe shoe fitters, and podiatrists agree that finding Pointe Shoes which fit correctly and adjust throughout your career could help to avoid feet injuries. The different parts of the shoe require different performance, depending on the different parts of the foot. Each dancer has particular feet, with variations of toe length and shape, arch flexibility, and mechanical strength. Instead of having the dancer’s feet adjusted on the point shoes, the idea is to have the shoes, uniquely ‘adapt’ according to the morphology of the feet. The foot is not just a passive weight-bearer, it must assume positions and execute movements beyond its normal limits. Therefore, the parameters to take in account are classified in anatomical, mechanical, assembly and material.
From the study, it is deduced that the above parameters may be the key to define a proposal for a solution to the design of Pointe shoe.Las puntas se usan durante la actuación "en pointe". Esta fundamental técnica de ballet, que se realiza levantándose a los dedos del pie, permite a los bailarines, crear la ilusión de una ligereza increíble y el aspecto de sílfide. Sin embargo, bailando en puntas causa dolor, ampollas, callos, y desfiguración de pies, comúnmente conocida entre los bailarines. Estas heridas pueden evitarse si los pies están mejor soportados. Bailarines, zapateros de punta, y podólogos están de acuerdo en que tener las zapatillas de punta que se adaptan y ajustan correctamente, a lo largo de carrera podrían ayudar a evitar las heridas en los pies. Cada bailarín tiene los pies únicos, con las variaciones de longitud de los dedos del pie y de su forma, la flexibilidad del arco, y la resistencia mecánica. En lugar de ajustar los pies del bailarín en las zapatillas de puntas, la idea es diseñar zapatos, que pueden "adaptarse" en forma única, según la morfología de los pies y también de la fuerza de los bailarines. El pie no es solo un portador pasivo de peso, debe asumir posiciones y ejecutar movimientos más allá de sus límites normales. Por tanto, los parámetros a tener en cuenta se clasifican en anatómicos, mecánicos, de montaje y material. Del estudio se deduce que los parámetros anteriores pueden ser la clave para definir una propuesta de solución al diseño de Pointe.
Patrimoni arquitectònic, civil, urbanístic i rehabilitació de construccions existents
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Sthal, Fabrice. "Microscopie acoustique en champ proche a pointe vibrante." Besançon, 1994. http://www.theses.fr/1994BESA2002.
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Ce memoire presente l'etude et la realisation d'un nouveau type de microscope acoustique en champ proche. Il utilise une pointe vibrante comme source d'excitation, de dimension inferieure a la longueur d'onde. La pointe en contact avec l'objet engendre des microdeformations a la surface de l'echantillon. Les contraintes mecaniques sont detectees sur la face opposee avec un transducteur piezoelectrique. Les images d'amplitude et de phase obtenues montrent les inhomogeneites de surface et du volume proches de la surface. Avec un tel dispositif, la resolution n'est plus liee, comme en microscopie conventionnelle, a la frequence de l'onde acoustique, mais elle depend du diametre de la pointe en contact avec l'objet. Nous decrivons le principe de fonctionnement et proposons une interpretation theorique. Un modele 3d montre que les ondes longitudinales sont tres attenuees pres de la pointe vibrante. Les resultats experimentaux obtenus sur des echantillons solides, pour une gamme de frequence de 20 a 150 hkz, montrent que la resolution est de l'ordre du micron. Cette resolution est superieure a #a/10000 ou #a est la longueur d'onde acoustique
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Proslier, Thomas. "Spectroscopie tunnel à balayage avec une pointe supraconductrice." Paris 6, 2006. http://www.theses.fr/2006PA066647.
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Lin, Haomin. "Disturbance attenuation in precise hexapod pointing control using positive force feedback." Laramie, Wyo. : University of Wyoming, 2005. http://proquest.umi.com/pqdweb?did=990288531&sid=1&Fmt=2&clientId=18949&RQT=309&VName=PQD.
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Fulford, Katy A. "Oculomotor responses and 3D displays." Thesis, Durham University, 1998. http://etheses.dur.ac.uk/4655/.
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This thesis investigated some of the eye movement factors related to the development and use of eye pointing devices with three dimensional displays (stereoscopic and linear perspective). In order for eye pointing to be used as a successful device for input-control of a 3D display it is necessary to characterise the accuracy and speed with which the binocular point of foveation can locate a particular point in 3D space. Linear perspective was found to be insufficient to elicit a change in the depth of the binocular point of fixation except under optimal conditions (monocular viewing, accommodative loop open and constant display paradigm). Comparison of the oculomotor responses made between a stereoscopic 'virtual' and a 'real' display showed there were no differences with regards to target fixational accuracy. With one exception, subjects showed the same degree of fixational accuracy with respect to target direction and depth. However, close target proximity (in terms of direction) affected the accuracy of fixation with respect to depth (but not direction). No differences were found between fixational accuracy of large and small targets under either display conditions. The visual conditions eliciting fast changes in the location of the binocular point of foveation, i.e. saccade disconjugacy, were investigated. Target-directed saccade disconjugacy was confirmed, in some cases, between targets presented at different depths on a stereoscopic display. However, in general the direction of saccade disconjugacy was best predicted by the horizontal direction of the target. Leftward saccade disconjugacy was more divergent than rightward. This asymmetry was overlaid on a disconjugacy response, which when considered in relative terms, was appropriated for the level of vergence demand. Linear perspective depth cues did not elicit target-directed disconjugate saccades.
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Grover, Lesley Ann. "Comprehension of the manual pointing gesture in human infants : a developmental study of the cognitive and social-cognitive processes involved in the comprehension of the gesture." Thesis, University of Southampton, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.329150.
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Argelaguet, Sanz Fernando. "Pointing facilitation techniques for 3d object selection on virtual environments." Doctoral thesis, Universitat Politècnica de Catalunya, 2011. http://hdl.handle.net/10803/33383.
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Les contribucions d’aquesta tesi s’emmarquen en la interacció home-computador en entorns de realitat virtual. Concretament, en la millora de tasques de selecció d’objectes tridimensionals. La selecció d’objectes és una tasca primordial en la interacció en entorns virtuals, doncs defineixen el curs de les accions de l’usuari envers l’entorn virtual. En aquesta tesi s’analitzen els factors que determinen l’eficiència de les tasques de selecció i es proposen millores en la seva usabilitat incrementant, tant la productivitat de l’usuari, com el seu confort. Al ser una tasca crítica, la seva millora és un factor prioritari.
Les tasques de selecció en un entorn tridimensional requereixen la interacció mitjançant gestos, per exemple, agafar un objecte amb les mans o apuntar-lo amb el dit. L’efectivitat d’una tasca de selecció depèn de múltiples factors, com podria ser l’habilitat de l’usuari o en la percepció espacial de l’entorn. La tesi es centra en l’estudi de les limitacions de les tasques de selecció i de com els models d’interacció home-màquina existents, permeten el seu replantejament per a millorar la seva eficiència. Al llarg de la tesi es proposen diverses tècniques de selecció basades en la llei de Fitts, i s’analitza com evitar la dependència en la percepció espacial. Els anàlisis teòrics es complementen amb estudis d’usabilitat on s’avalua, tant l’efectivitat de les solucions proposades, com les ja existents.
Encara que la major part de contribucions es centren en la selecció d’objectes tridimensionals, també s’estudia la selecció i manipulació d’interfícies gràfiques d’usuari 2D en entorns virtuals, i en la millora de la transferència d’informació entre usuaris en entorns col·laboratius. En aquests tipus d’entorns, és comú l’ús de la selecció per fer referència a determinats objectes o característiques del medi, a altres usuaris. No obstant, la impossibilitat de veure els objectes amb els què d’altres usuaris estan interactuant, dificulta l’intercanvi d’informació entre ells. S’ha fet un estudi de les eines utilitzades per a la gestió de l’oclusió i de com milloren l’intercanvi d’informació entre usuaris.
Lloc iLes contribucions d’aquesta tesi s’emmarquen en la interacció home-computador en entorns de realitat virtual. Concretament, en la millora de tasques de selecció d’objectes tridimensionals. La selecció d’objectes és una tasca primordial en la interacció en entorns virtuals, doncs defineixen el curs de les accions de l’usuari envers l’entorn virtual. En aquesta tesi s’analitzen els factors que determinen l’eficiència de les tasques de selecció i es proposen millores en la seva usabilitat incrementant, tant la productivitat de l’usuari, com el seu confort. Al ser una tasca crítica, la seva millora és un factor prioritari. Les tasques de selecció en un entorn tridimensional requereixen la interacció mitjançant gestos, per exemple, agafar un objecte amb les mans o apuntar-lo amb el dit. L’efectivitat d’una tasca de selecció depèn de múltiples factors, com podria ser l’habilitat de l’usuari o en la percepció espacial de l’entorn. La tesi es centra en l’estudi de les limitacions de les tasques de selecció i de com els models d’interacció home-màquina existents, permeten el seu replantejament per a millorar la seva eficiència. Al llarg de la tesi es proposen diverses tècniques de selecció basades en la llei de Fitts, i s’analitza com evitar la dependència en la percepció espacial. Els anàlisis teòrics es complementen amb estudis d’usabilitat on s’avalua, tant l’efectivitat de les solucions proposades, com les ja existents. Encara que la major part de contribucions es centren en la selecció d’objectes tridimensionals, també s’estudia la selecció i manipulació d’interfícies gràfiques d’usuari 2D en entorns virtuals, i en la millora de la transferència d’informació entre usuaris en entorns col·laboratius. En aquests tipus d’entorns, és comú l’ús de la selecció per fer referència a determinats objectes o característiques del medi, a altres usuaris. No obstant, la impossibilitat de veure els objectes amb els què d’altres usuaris estan interactuant, dificulta l’intercanvi d’informació entre ells. S’ha fet un estudi de les eines utilitzades per a la gestió de l’oclusió i de com milloren l’intercanvi d’informació entre usuaris. Lloc i
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dePalma, Nicholas Brian. "Task transparency in learning by demonstration : gaze, pointing, and dialog." Thesis, Georgia Institute of Technology, 2010. http://hdl.handle.net/1853/34702.
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This body of work explores an emerging aspect of human-robot interaction, transparency. Socially guided machine learning has proven that highly immersive robotic behaviors have yielded better results than lesser interactive behaviors for performance and shorter training time. While other work explores this transparency in learning by demonstration using non-verbal cues to point out the importance or preference users may have towards behaviors, my work follows this argument and attempts to extend it by offering cues to the internal task representation.
What I show is that task-transparency, or the ability to connect and discuss the task in a fluent way implores the user to shape and correct the learned goal in ways that may be impossible by other present day learning by demonstration methods. Additionally, some participants are shown to prefer task-transparent robots which appear to have the ability of "introspection" in which it can modify the learned goal by other methods than just demonstration.
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Merla, J. Leann. "An electromyographic and kinematic comparison of two computer pointing devices." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk2/tape17/PQDD_0026/MQ30681.pdf.
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Bell, Candace. "Detection of the riming process with a vertically pointing radar." Thesis, McGill University, 2000. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=33378.
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Supercooled cloud liquid water (SCW), which causes aircraft icing, can be detected indirectly by observing characteristics of the bright band with a vertically pointing radar. Accretion of supercooled water droplets on precipitating snow (riming) increases the density and fall speed of snow and decreases the intensity of the bright band. For stratiform precipitation with a melting layer, a small peak-to-rain reflectivity difference and a high snow-to-rain velocity ratio indicate high-density snow. A numerical model of the bright band gives a semi-quantitative relationship between snow density and bright band parameters. SCW content is computed theoretically and depends on the gradient of mass flux with height above the melting layer. A large mass flux gradient is an indication of growth by riming.
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Lane, Andrew. "Real-time weather radar correlation using a vertically pointing radar." Thesis, University of Salford, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.244841.
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Yaquinto, Brennen Ritter Yaquinto. "Rapid Pointing Performance Comparison between Spectacle and Contact Lens Wear." The Ohio State University, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=osu1522243382611988.
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FOURNEL, MICHELE. "Interactions entre une pointe et une surface metallique a l'echelle nanometrique : pointe tunnel (pt) et surface au(111) en conditions ambiantes." Paris 7, 1997. http://www.theses.fr/1997PA077212.
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Dans ce travail, nous nous sommes interesses aux processus physiques qui accompagnent la formation de contacts, a l'echelle nanometrique, entre une pointe de platine et une surface d'or (111), dans le cadre d'experiences de microscopie a effet tunnel en conditions ambiantes. Le but etait d'obtenir des resultats utiles aux etudes de frottement et d'usure a l'echelle macroscopique. Le premier phenomene etudie fut la formation de jonctions metalliques transitoires (30 s) au niveau des marches de la surface ou la distance pointe-surface tombe en deca d'un seuil de l'ordre de l'angstrom. La largeur de ces jonctions est d'une dizaine d'atomes et leur rupture se traduit par un transfert d'atomes d'or (de 1 a 200 atomes) dont le sens (surface vers pointe ou vice versa) est determine par la geometrie de l'interface avant contact. Un temps de diffusion des atomes d'or le long de la pointe limite quantitativement ce transfert, les adsorbats presents sur la surface d'or le favorisent et il semble que leur diffusion sur la surface soit a l'origine d'un temps de relaxation (1 sec) de celle-ci entre deux interactions successives en un meme point d'une marche. Le second phenomene etudie est la formation, sur la surface, de structures longilignes, larges de 55 a et facettees : des doigts. Ceux-ci semblent etre la consequence d'un frottement de type lubrifie entre la pointe et la surface, via une couche de contaminants. L'orientation des doigts est un compromis entre la direction de balayage de la pointe (direction de la force de frottement) et les directions cristallographiques denses de la surface ; leur croissance se fait grace a des mouvements d'atomes sous contrainte, jusqu'a cent fois plus rapides que les mouvements de diffusion usuels. Ces doigts conduisent a une morphologie finale de la surface tres facettee par rapport celle initiale, ils constitueraient ainsi un etat transitoire permettant au systeme d'evoluer vers un etat de moindre energie.
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Huebner, Seth. "The finger pointing to the moon Perennial philosophy and John Milton /." Pullman, Wash. : Washington State University, 2010. http://www.dissertations.wsu.edu/Thesis/Spring2010/s_huebner_041610.pdf.
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