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1
Mishina, Tatiana. « Pressure-induced collisional parameters of rovibrational lines of water vapour and ozone ». Besançon, 2010. http://www.theses.fr/2010BESA2036.
Texte intégralRésumé :
The information about rotation-vibration spectral lines of water vapour and ozone is necessary for atmospheric studies, modeling of radiation transfer, climate changes, ozone layer depletion and green house effect. The goals of the present work are focused on improvements and testing some existing semi-classical and semi empirical methods for colisional line width and shift calculation, as wel as on studies of the influence of interference of water spectral lines on the atmospheric absorption coefficient. The main new result obtained are the following ; I, using the generalized Euler transformation for the summation of divergent series allowed obtaining a convergent expression of the interruption (or “efficency”) function and calculation of new resonance functions in the cases of strong (HF-HF) and weak (CO-CO) dipole-dipole and dipole quadrupole (HF-N2)interactions; II nitrogen and oxygen-broadening coefficients of ozone lines were calculated by semi-classical RBE and semi-empirical methods for the v1+v3 band; III, vibrational dependence of classical trajectories was studied for the 1 th order contribution to the rovibrational shifts of O3-N2 lines in the framework of semi classical RB approach with exact trajectories and vibrational dependence of isotropic potential coming from O3 dipole moment and polarizability; IV, values of effective dipole polarizability in excited vibrational state were obtained for all vibrational bands of water vap our experimentally studied in the litterature; V, colisional parameters of water vapour spectral lines were calculated for highly excited ro-vibrational states up to the dissociation limit of 25 000 Cm-1; VI, interference of slanting atmospheric paths for winter conditions of mid-latitude atmosphere model and to the disappearance of micro window region for increasing zenithal angleLes informations sur les raies de rotation-vibration de la vapeur d'eau et de l'ozone sont nécessaires pour les études atmosphériques ainsi que pour la modélisation du transfert radiatif, des changements du climat, la diminution de la couche d'ozone et de l'effet de serre. Les objectifs de ce travail sont focalisés sue des améliorations et des tests de certaines méthodes semi-classiques et semi-empiriques existantes pour calculer les largeurs et les déplacements collisionnels de raies spectrales ainsi que sur études de l'influence de l'interface de raies spectrales de la vapeur d'eau sur le coefficient d'absorption dans l'atmosphère. Les principaux résultats obtenus sont les suivants : I , l'utilisation de la transformation généralisée d'Euler pour la sommation de séries divergentes a permis d'obtenir une expression convergente pour la fonction d'interruption et calculer les nouvelles fonctions de résonance dans le cas des interactions dipôle-dipôle forte (HF-HF) et faible (CO-CO) et interaction dipôle-quadrupole (HF-N2) ;II, des coefficients d'élargissement de raies d'ozone par l'azote et l’oxygéné ont été calculés par la méthode semi classique RB avec trajectoires exactes (RBE) et par la méthode semi-empirique pour la bande v1+v3 ; III, la dépendance vibrationnelle des trajectoires classiques a été étudiée pour la contribution du 1er ordre dans le déplacement de raies O3-N2 rovibrationnelles dans le cadre de la méthode semi-classique RBE aisi que la dépendance vibrationnelle du potentiel isotope venant du moment dipolaire et de la polarisabilité de O3 ; IV, les valeurs de la polarisabilité dipolaire effective dans les états vibrationnels excités ont été obtenues pour toutes les bandes vibrationnelles de la vapeur d'eau étudiées expérimentalement dans la littérature ; V, les paramètres collisionnels de raies spectrales de la vapeur d'eau ont été calculés pour les états rovibrationnels très fortement excités, jusqu'à la limite de dissociation 25 000 Cm-1 ; VI, il est démontré que l'interface de raies spectrales de la vapeur d'eau conduit à une erreur notable dans le calcul du coefficient d'absorption atmosphérique pour des trajets inclinés dans les conditions d'hiver du modèle « mid-latitude » de l'atmosphère ainsi qu'à la disparition de la région de la micro-fenête pour les grandes valeurs de l'angle du zénith
2
Khalid, Muhammad. « Influence of solvent viscosity, polarity and polarizability on the chemiluminescence parameters of inter and intramolecular electron transfer initiated chemiexcitation systems ». Universidade de São Paulo, 2015. http://www.teses.usp.br/teses/disponiveis/46/46136/tde-29092015-114251/.
Texte intégralRésumé :
The cyclic peroxides: diphenoyl peroxide (1), spiro-adamantyl-1,2-dioxetanone (2) and 4-(3-tert-butyldimethylsilyloxyphenyl)-4-methoxyspiro[1.2-dioxetane-3.2\'-adamantane] (3) synthesized, purified and characterized, also their kinetic and chemiluminescence (CL) properties were determined. The influence of solvent polarity on the chemiexcitation parameters of the catalyzed decomposition of 1 and 2, as well as the induced decomposition of 3 were examined in several binary solvent mixtures with different polarity and polarizability parameters, but similar viscosities. For solvents with low polarity, singlet quantum yields for the intermolecular catalyzed decomposition of diphenoyl peroxide (1,) and 1,2-dioxetanone (2) increase in function of medium polarity, showing maximum values in mediums of intermediate polarity, and decreasing in highly polar mixtures. For the induced decomposition of 3, the quantum yield showed to increase with increasing solvent polarity, including high polar solvent systems. In the binary solvent systems studied, the polarizability parameter showed to be contrary to the polarity values, therefore, it might appear that an increase of polarizability leads to a decrease in the singlet quantum yields for catalyzed decomposition of diphenoyl peroxide (1) and the induced decomposition of 3, however an increase in the singlet quantum yields for 1,2-dioxetanone 2. The three CL systems were also studied in binary solvent mixtures with different viscosities but similar polarity and polarizability parameters and singlet quantum yields showed an increase with increasing medium viscosity. Data were analyzed by using the collisional and the free volume models. The highly efficient intramolecular system induced 1,2-dioxetane 3 decomposition showed to be much more sensible to viscosity effects than the inefficient intermolecular systems. This surprising fact indicates that, even showing a significant solvent-cage effect, the induced 1,2-dioxetane should occur by an intramolecular electron back transfer. Moreover, chemiluminescence parameters of these systems were studied in several pure solvents. The obtained singlet quantum yields were correlated with viscosity, polarizability and polarity parameters by using multiple linear regression analysis.Os peróxidos cíclicos: peróxido de difenoila (1), spiro-adamantil-1,2-dioxetanona (2) e 4-(3-terc-butildimetilsililoxifenil)-4-metoxispiro[1,2-dioxetano-3.2\'-adamantano] (3) foram sintetizados, purificados e caracterizados e as suas propriedades cinéticas e de quimiluminescência (CL) determinadas. A influência da polaridade do solvente sobre os parâmetros de quimi-excitação da decomposição catalisada de 1 e 2, e a decomposição induzida de 3 foi examinada em diversas misturas binárias de solventes com parâmetros de polaridade e polarizabilidade diferente, mas viscosidades semelhantes. Para solventes com baixa polaridade, os rendimentos quânticos singlete para a decomposição catalisada intermolecular do peróxido de difenoila (1) e 1,2-dioxetanona (2) aumentam em função da polaridade do meio, mostrando valores máximos em meios com polaridade intermediária, e diminuim para misturas altamente polares. Para a decomposição induzida de 3, o rendimento quântico mostrou aumentar com o aumento da polaridade do solvente, inclusive para sistemas com alta polaridade. Nos sistemas binários de solventes estudados, os parâmetros de polarizabilidade mostraram-se contrários aos valores de polaridade, portanto, parece que um aumento da polarizability leva a uma diminuição nos rendimentos quânticos singlete para a decomposição catalisada do peróxido de difenoila (1) e a decomposição induzida de 3, no entanto, um aumento nos rendimentos quânticos singlete para a 1,2-dioxetanona 2. Os três sistemas de CL também foram estudados em misturas binárias de solventes com diferentes viscosidades, mas com parâmetros de polaridade e polarizabilidade semelhantes e os rendimentos quânticos singlete mostraram aumentar com o aumento da viscosidade do meio. Os dados foram analisados usando tanto o modelos colisional quando o modelo de volume livre. Surpreendentemente, o sistema altamente eficiente decomposição induzida intramolecular do 1,2-dioxetano 3 mostrou-se muito mais sensível aos efeitos da viscosidade do que os sistemas intermoleculares ineficientes, o que indica claramente que a decomposição induzida do 1,2-dioxetano deve ocorrer por um processo de retro-transferência de elétron intramolecular. Além disso, os parâmetros de quimiluminescência destes sistemas foram estudados em vários solventes puros. Os rendimentos quânticos singlete obtidos foram correlacionados com parâmetros de viscosidade, polarizabilidade e polaridade usando análise de regressão linear múltipla.
3
Troitsyna, Larisa. « Approche semi-classique aux paramètres collisionnels de raies spectrales de CH3I pour applications atmosphériques et planétologiques ». Electronic Thesis or Diss., Bourgogne Franche-Comté, 2021. http://www.theses.fr/2021UBFCD061.
Texte intégralRésumé :
La molécule d'iodure de méthyle CH3I est devenue récemment l'objet d'études spectroscopiques intenses en raison de son rôle dans la diminution de la couche d'ozone et de son danger pour la santé humaine au cas d'une émission accidentelle dans l’atmosphère. La bande fondamentale nu6 apparaît particulièrement adaptée à la détection atmosphérique de CH3I, car elle tombe dans la fenêtre de transparence à 11mu m. Cependant, les paramètres spectroscopiques actuellement disponibles pour CH3I perturbé par les principales espèces atmosphériques sont limités à quelques mesures extrêmement rares à température ambiante et manquent dans les bases de données spectroscopiques. Pour compléter / remplacer les données expérimentales manquantes, dans le cadre du Projet de Recherche International franco-russe SAMIA, les coefficients d'élargissement de raies pour les paires atmosphériques clés CH3I-CH3I, CH3I-N2, CH3I-O2, CH3I-air sont calculés de manière semi classique, avec l'utilisation du formalisme de Robert-Bonamy amélioré par des trajectoires exactes, dans de larges gammes de nombres quantiques rotationnels typiquement demandés par les bases de données (0 < J < 70, K < 20) et pour les six sous-branches RP, PP, RQ PQ, RR, PR de la bande nu6 ; leur dépendance vibrationnelle ainsi que les dépendances de sous-branche et en température (avec la loi exponentielle traditionnelle et la nouvelle loi "double-power" ) sont également abordées. Des arguments sont donnés pour justifier ce choix de la méthode facilement praticable face à ses modifications avancées mais moins en accord avec les mesures. Des comparaisons sont faites avec les mesures disponibles et des résultats semi empiriques alternatifs, indiquant l'importance du modèle de potentiel d'interaction, en particulier de sa partie isotrope pilotant les trajectoires, pour une description réaliste des largeurs de raies collisionnellesMethyl iodide molecule CH3I has come recently into focus of intense spectroscopic studies due to its role in the ozone layer depletion and its danger for human health in case of an accidental release in the atmosphere. For its atmospheric detection particularly suitable is the nu6 fundamental, which falls into the transparency window at 11 mu m. However, currently available spectroscopic line-shape parameters for CH3I perturbed by main atmospheric species are limited to some extremely scarce measurements at ambient temperature and are missing in spectroscopic databases. To supplement/replace the missing experimental data, in the frame of the French-Russian International Research Project SAMIA, room-temperature (296 K) line-broadening coefficients for the key atmospheric pairs CH3I-CH3I, CH3I-N2, CH3I-O2,CH3I-air are calculated semi-classically, with the use of the Robert-Bonamy formalism improved by exact trajectories, in wide ranges of rotational quantum numbers typically requested by databases (0 < J < 70, K < 20) and for all six sub-branches RP, PP, RQ PQ, RR, PR of the nu6 band; their vibrational dependence as well as sub-branch dependence and temperature dependence (with the traditional power and recently suggested double-power laws) are also addressed. Arguments are given to support this choice of the easily practicable method contrary to its advanced but less agreeing with measurements modifications. Comparisons are made with available measurements and alternative semi-empirical results, indicating the importance of the interaction potential model, in particular of its isotropic part governing the trajectories, for a realistic description of collisional line-widths
4
Hwang, Lorraine J. « Teleseismically determined source parameters of several large collision-zone earthquakes / ». Diss., Pasadena, Calif. : California Institute of Technology, 1991. http://resolver.caltech.edu/CaltechETD:etd-06292005-161026.
Texte intégral
5
Shore, Patrick. « Swinging Babe's Bat : Optimizing Home Run Distance Using Ideal Parameters ». Scholarship @ Claremont, 2019. https://scholarship.claremont.edu/cmc_theses/2226.
Texte intégralRésumé :
Significant research has been conducted on the physics of ball and bat collisions in an effort to model and understand real-world conditions. This thesis expands upon previous research to determine the maximum distance a ball can travel under ideal circumstances. Bat mass, bat speed, pitch speed and pitch spin were controlled values. These values were selected based on the highest recorded MLB values for their respective category. Specifically these are: Babe Ruth’s largest bat, Giancarlo Stanton’s recorded swing speed and Aroldis Chapman’s fastest fastball. A model was developed for a planar collision between a bat and ball using conservation laws in order to achieve the maximum exit velocity of the ball during a head-on collision. However, this thesis is focused on home runs and long fly-balls that occur from oblique collisions rather than the line drives produced by head-on collisions. The planar collision model results were adjusted to oblique collisions based on data from previous experimental research. The ball and bat were assumed to be moving in opposite directions parallel to one another at the point of impact with the ball slightly elevated above the bat. The post-collision results for the launch angle, spin and final exit velocity of the ball were calculated as functions of the perpendicular distance from the centerline of the bat to the centerline of the ball. Trajectories of the ball were calculated using a flight model that measured the final distance of the ball based on lift and drag forces. The results indicate that the optimum pre-collision parameters described above will maximize the distance traveled by the ball well beyond the farthest recorded home run distance. Experimentally determined factors such as the drag coefficient and coefficient of restitution have a significant impact on the flight of the ball. Implications of the results are discussed.
6
Abdurakhmanov, Ilkhom. « Impact-parameter convergent close-coupling approach to antiproton-atom collisions ». Thesis, Curtin University, 2011. http://hdl.handle.net/20.500.11937/1721.
Texte intégralRésumé :
This thesis is devoted to extension of the convergent close-coupling (CCC) method to heavy projectiles and its application to the theoretical studies of antiproton scattering on the hydrogen and helium targets.In the Introduction (Chapter 1) the motivation for the study and the current status of antiproton scattering on hydrogen and helium are presented. Other theoretical methods that previously have been applied to these problems are reviewed and their limitations are indicated. The extension of the fully quantummechanical CCC method to ion-atom collisions is presented in Chapter 2. The derivations of the momentum-space coupled-channel Lippmann-Schwinger integral equations from the exact Schr¨odinger equation is given in detail. Transition matrix elements are derived in momentum-space. In Chapter 3 a direct method for solving multi-dimensional Lippmann-Schwinger integral equations without recourse to partial-wave expansion or any other transformation scheme will be described. A direct method has been applied to the antiproton-hydrogen as well as to the proton-hydrogen collisions. In Chapter 4 we solve the full multichannel problem by transforming the coupled-channel integral equations into the impactparameter representation. The scattering amplitude necessary to calculate the differential and total cross sections will be derived from the transition matrix elements. The results of the CCC calculations for antiproton scattering from atomic hydrogen and helium are presented and compared with available experimental data and the results of other calculations in Chapter 5 and Chapter 6, respectively. Finally, in Chapter 7, we draw conclusions arising from this work and indicate future directions for the research.Main results of this work • The convergent close-coupling method has been extended to heavy projectiles and applied to antiproton scattering on atomic hydrogen and helium. • For the first time, the relative motion of the heavy particles in antiproton collisions with atomic hydrogen and helium has been treated quantummechanically. • A direct method to solving the three-dimensional momentum-space coupledchannel Lippmann-Schwinger integral equations has been developed. • A scheme for transforming the three-dimensional Lippmann-Schwinger integral equations into the impact-parameter representation has been developed. The fully off-shell transition matrix elements in the impactparameter space have been derived. • For the first time, the fully quantum mechanical calculations of the cross sections for all the major channels of interest in antiproton collisions with hydrogen and helium have been performed over a wide range of scattering energies. • The total ionization cross sections for the H target has been calculated. The results are in excellent agreement with the available experiment. An overall agreement of the present results with the semiclassical calculations by other groups has practically confirmed the validity of the semiclassical approximation imposed on the relative heavy particle motion. • The total cross section for the He single ionization has been calculated using frozen-core (FC) and multi-configuration (MC) approximation for the target. As opposed to rather sophisticated and rigorous MC calculations the FC results agree with the experimental data at a wider energy range. • For the first time, based on the fully quantum-mechanical treatment of the problem the triple differential cross sections have been calculated for antiproton scattering on both H and He.• The p−H results for the various differential ionization cross sections agree reasonably well with the results of the semiclassical close-coupling and the continuum-distorted-wave-eikonal-initial-state (CDW-EIS) approaches, particularly at high energies. • The longitudinal ejected electron and recoil-ion momentum distributions for the single ionization of helium have been calculated. The results are in good agreement with the available experimental data.
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Martin, Matthew S. « Preliminary studies concerning [Delta gamma]Bs measurements in proton antiproton collisions at [root of]s = 2.0 TeV ». Thesis, University of Oxford, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.275261.
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Movahedi-Lankarani, Hamid. « Canonical equations of motion and estimation of parameters in the analysis of impact problems ». Diss., The University of Arizona, 1988. http://hdl.handle.net/10150/184490.
Texte intégralRésumé :
The transient dynamic analysis of constrained mechanical systems may require the solution of a mixed set of algebraic and differential equations of motion. The usual formulation of these equations is expressed in terms of the accelerations of the system components. A canonical form of the equations of motion in terms of the system velocities and the time derivative of the system momenta may be used instead. This is a natural form of the equations in which all the state variables are explicitly expressed, and have the same physical importance. The numerical solution obtained from the canonical equations shows more accuracy and stability, specifically for systems with large and fluctuating forces. For the mechanical systems that undergo an impact, the usual numerical solution of the equations of motion is not valid. Two different methods of analysis of impact problems are presented. In one method, the variations of the impulsive force during the contact period are directly added to the vector of forces in the canonical equations of motion. In the second method, based on the assumption of instantaneous nature of impact, a set of momentum balance-impulse equations is derived by explicitly integrating the canonical equations. These equations are solved at the time of impact for the jump in the system momenta right after impact. Necessary parameters are evaluated for the performance of the two methods of analysis. These parameters include the maximum relative indentation, the maximum contact force, and the coefficient of restitution. The parameters are determined for the collision between two bodies in a system with any general geometric or material properties. The influence of friction modeling in the magnitude and the direction of the total force at the contact surfaces is discussed. The dynamics of a vehicle collision is studied in order to illustrate the efficiency of obtaining a solution to the canonical equations, the simplicity of solving the momentum balance-impulse equations.
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Wheaton, Spencer Miles. « The centrality dependence of thermal parameters in Pb-Pb collisions at 158 GeV/nucleon ». Master's thesis, University of Cape Town, 2001. http://hdl.handle.net/11427/6512.
Texte intégralRésumé :
Includes bibliographical references.A review of the Hardon Gas model and its application to Pb+Pb CERN SPS collision data at a beam energy of 158 GeV/nucleon. The centrality dependence of the freeze-out parameters, characterizing both the hadron multiplicities and the transverse momentum spectra, are determined. This privides valuable information on the effect of the system size on chemical-and thermal frees-out and contributions towards the systematic understandig of the experimental data.
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Varas, Jaime Armando. « Employment of neural networks in the estimation of impact parameters ». Thesis, The University of Sydney, 2002. https://hdl.handle.net/2123/27885.
Texte intégralRésumé :
In this study, we employed a two-stage backpropagation neural network (NNW) to estimate
the impact parameter (b) of heavy-ion collisions. Using Monte-Carlo (MC) generated Pb-Pb
events at 160 GeV/nucleon we employed three observables from each event to train the
NNW. The generated events were target-projectile in nature, from which the charged pion
multiplicity (MULT), largest spectator fragment (ZMAX) and charge flow in the forward
direction (sz) were used as input signals for the NNW.
A statistical approach that employed the weighted mean of the three inputs to estimate b was
used as a test method, against which the NNW's results were compared. The results showed,
that the NNW was as accurate as the weighted mean in estimating b.
Using central events fom EMUOl data comprising of Au-Au events at 11 GeV/nucleon and
Pb-Pb events at 158 GeV/nucleon, we extracted the observables MULT, ZMAX and Qm
from each event, and utilising the trained NNW we estimated b.
A comparison of MC generated events of a similar b range was made with our EMUOl
results, and it was shown that the two data sets agreed within statistical errors. A further
comparison of the pseudorapidity distribution between the two data sets revealed that the
estimated b for the EMUOl data, was consistent with the MC data.
11
Wolinski, David. « Microscopic crowd simulation : evaluation and development of algorithms ». Thesis, Rennes 1, 2016. http://www.theses.fr/2016REN1S036/document.
Texte intégralRésumé :
Dû au grand intérêt porté à la simulation de foules, beaucoup d'algorithmes ont été et sont encore proposés. Toutefois, (1) il n'existe pas de méthode standard pour évaluer le réalisme et la flexibilité de ces algorithmes, et (2) même les algorithmes les plus récents produisent encore des artéfacts évidents. Abordant la première question, nous proposons une méthode visant à évaluer le réalisme des algorithmes de simulation de foules d'une manière objective et impartiale. ''Objective'' grâce à des métriques quantifiant la similitude entre les simulations et des données acquises en situation réelle. ''Impartiale'' grâce à l'estimation de paramètres permettant d'étalonner automatiquement les algorithmes en vue de décrire au mieux les données (par rapport aux métriques), permettant de comparer les algorithmes au mieux de leur capacité. Nous explorons aussi comment ce processus permet d'augmenter le niveau de contrôle d'un utilisateur sur la simulation tout en réduisant son implication. Abordant la deuxième question, nous proposons un nouvel algorithme d'évitement de collisions. Alors que les algorithmes existants prédisent les collisions en extrapolant linéairement les trajectoires des agents, nous allons au-delà grâce à une approche probabiliste et non-linéaire, prenant en compte entre autres la configuration de l'environnement, les trajectoires passées et les interactions avec les obstacles. Nous éliminons ainsi des simulations résultantes des artefacts tels que : les ralentissements et les agglomérats dérangeants d'agents, les mouvements oscillatoires non naturels, ou encore les manœuvres d'évitement exagérées/fausses/de dernière minute. Dans une troisième contribution, nous abordons aussi l'utilisation de notre travail sur l'évaluation et l'estimation de paramètres dans le cadre de systèmes plus larges. Dans un premier temps, nous l'appliquons à la simulation d'insectes, prenant en charge leur comportement local. Après avoir complété le système aux niveaux intermédiaire et global, cette approche basée-données est capable de simuler correctement des essaims d'insectes. Dans un second temps, nous appliquons notre travail au suivi de piétons, construisant un ''méta-algorithme'' servant à calculer la probabilité de transition d'un filtre particulaire, et surpassant les systèmes existantsWith the considerable attention crowd simulation has received, many algorithms have been and are being proposed. Yet, (1) there exists no standard scheme to evaluate the accuracy and flexibility of these algorithms, and (2) even the most recent algorithms produce noticeable simulation artifacts. Addressing the first issue, we propose a framework aiming to provide an objective and fair evaluation of the realism of crowd simulation algorithms. ''Objective'' here means the use of various metrics quantifying the similarity between simulations and ground-truth data acquired with real pedestrians. ''Fair'' here means the use of parameter estimation to automatically tune the tested algorithms to match the ground-truth data as closely as possible (with respect to the metrics), effectively allowing to compare algorithms at the best of their capability. We also explore how this process can increase a user's control on the simulation while reducing the amount of necessary intervention. Addressing the second issue, we propose a new collision-avoidance algorithm. Where current algorithms predict collisions by linearly extrapolating agents' trajectories, we better predict agents' future motions in a probabilistic, non-linear way, taking into account environment layout, agent's past trajectories and interactions with other obstacles among other cues. Resulting simulations do away with common artifacts such as: slowdowns and visually erroneous agent agglutinations, unnatural oscillation motions, or exaggerated/last-minute/false-positive avoidance manoeuvres. In a third contribution, we also explore how evaluation and parameter estimation can be used as part of wider systems. First, we apply it to insect simulation, taking care of local insect behavior. After completing it at the intermediate and global levels, the resulting data-driven system is able to correctly simulate insect swarms. Second, we apply our work to pedestrian tracking, constructing a ''meta-algorithm'', more accurately computing motion priors for a particle-filter-based tracker, outperforming existing systems
12
Sawa, Masanori. « Optical Orthogonal Signature Pattern Codes with Maximum Collision Parameter 2 and Weight 4 ». IEEE, 2010. http://hdl.handle.net/2237/14501.
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Tasinato, Nicola <1981>. « Infrared Spectroscopy of Atmospherical and Astrophysical relevant Molecules : Spectral analysis, Line parameter retrievals and Study of collisional decay processes ». Doctoral thesis, Università Ca' Foscari Venezia, 2010. http://hdl.handle.net/10579/71.
Texte intégralRésumé :
This thesis encompasses different topics in the research field of IR spectroscopy, which includes line-by-line parameter and absorption cross sections retrievals, medium and high resolution analysis, and investigations about collisional processes. The research involving the line-by-line analysis has led to the development of a line-fitting software, VLSFP. Then, the line parameters of SO2 and H2C=CHF has been determined in the 8 – 9 mm atmospheric window by TDL spectroscopy. At medium resolution, the FT-IR spectrum of H2C=CHF has been investigated experimentally and through CCSD(T) ab-initio calculations. At high resolution, the spectrum of CF3Br, has been analysed in the 2v50 and v2 + v3 band regions. Absorption cross sections have been measured for SO2, H2C=CHF and CF3Br. Finally, the physics of the interactions of chirped IR laser radiation with low pressure gases, H2O, N2O and CO2, have been investigated by the frequency down-chirped radiation emitted by a QCL spectrometer employed in the intra-pulse method.
14
LEPERE, MURIEL. « Parametres d'intensite et coefficients d'elargissement collisionnel de raies du fluorure de methyle par spectroscopie diode-laser ». Paris 11, 1999. http://www.theses.fr/1999PA112097.
Texte intégralRésumé :
L'objectif de cette these etait de determiner les parametres des raies d'absorption moleculaire du fluorure de methyle, et plus particulierement les intensites et les coefficients d'elargissement collisionnel de raies. Dans une premiere partie, nous avons, pour la premiere fois, mesure les intensites de raies des bandes v 2, v 3, v 5 et v 6. Ces mesures nous ont permis de comparer deux methodes de determination experimentale des intensites : la methode de la largeur equivalente (mle) et la methode d'ajustement de profil (map). Lors de l'utilisation de la methode map, le profil de rautian apparait preferable a celui de voigt. A partir des intensites de raies, nous avons ete capables d'en deduire les forces de bandes meme dans le cas de forte interaction. Dans la deuxieme partie, nous nous sommes interesses aux coefficients d'elargissement collisionnel. Les determinations experimentales ont ete realisees par ajustements des profils de voigt et de rautian. Nous sous sommes interesses, de cette maniere, a cinq melanges gazeux differents : ch 3f+ch 3f, ch 3f+n 2, ch 3f+o 2, ch 3f+he et ch 3f+ar. Nos determinations experimentales des coefficients d'elargissement ont ete comparees a une prediction theorique. Le calcul semi-classique de ces coefficients a ete realise a partir du modele theorique d'anderson, tsao et curnutte, auquel nous avons apporte certaines des ameliorations proposees par robert et bonamy.
15
Boletti, Alessio. « Measurement of angular parameters from the decay B0 -> ; K*0 \mu + \mu - in proton-proton collisions at \sqrt{} s = 8 TeV ». Doctoral thesis, Università degli studi di Padova, 2018. http://hdl.handle.net/11577/3422671.
Texte intégralRésumé :
Angular distributions of the decay B0 → K∗0 μ+ μ− are studied using a sample of proton-proton collisions at sqrt(s) = 8 TeV collected with the CMS detector at the LHC, corresponding to an integrated luminosity of 20.5 fb^−1. An angular analysis is performed to determine the P 1 and P'5 parameters, where the P'5 parameter is of particular interest because of recent measurements that indicate a potential discrepancy with the standard model predictions. Based on a sample of 1397 signal events, the P1 and P'5 parameters are determined as a function of the dimuon invariant mass squared. The measurements are in agreement with predictions based on the standard model.Le distribuzioni angolari del decadimento B0 → K∗0 μ+ μ− sono studiate usando i dati raccolti dall'esperimento CMS a LHC, in collisioni protone-protone a sqrt(s) = 8 TeV, e corrispondenti ad una luminosita` integrata di 20.5 fb^−1. E` eseguita un'analisi angolare per determinare i parametri P1 e P'5, ove il parametro P'5 e` di particolare interesse per via di recenti misure che indicano una potenziale discrepanza rispetto alle predizioni del modello standard. Sulla base di un campione di 1397 eventi di segnale, i parametri P1 e P'5 sono misurati in funzione del quadrato della massa del sistema dimuonico. Le misure risultano in accordo con le predizioni basate sul modello standard.
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Wolfe, Sage M. « Heavy Truck Modeling and Estimation for Vehicle-to-Vehicle Collision Avoidance Systems ». The Ohio State University, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=osu1405704063.
Texte intégral
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Heide, Markus [Verfasser], et Johannes Peter [Akademischer Betreuer] Wessels. « Measurement of semi-electronic beauty hadron decays via their impact parameter in pp collisions in ALICE / Markus Heide ; Betreuer : Johannes Peter Wessels ». Münster : Universitäts- und Landesbibliothek Münster, 2014. http://d-nb.info/1137329963/34.
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Heide, Markus [Verfasser], et Johannes P. [Akademischer Betreuer] Wessels. « Measurement of semi-electronic beauty hadron decays via their impact parameter in pp collisions in ALICE / Markus Heide ; Betreuer : Johannes Peter Wessels ». Münster : Universitäts- und Landesbibliothek Münster, 2014. http://d-nb.info/1137329963/34.
Texte intégral
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Natsupakpong, Suriya. « Physically Based Modeling and Simulation for Virtual Environment based Surgical Training ». Case Western Reserve University School of Graduate Studies / OhioLINK, 2010. http://rave.ohiolink.edu/etdc/view?acc_num=case1259182314.
Texte intégral
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Taliotis, Anastasios S. « Evolving Geometries in General Relativity ». The Ohio State University, 2010. http://rave.ohiolink.edu/etdc/view?acc_num=osu1274838401.
Texte intégral
21
Giftsun, Nirmal. « Handling uncertainty and variability in robot control ». Thesis, Toulouse, INSA, 2017. http://www.theses.fr/2017ISAT0028/document.
Texte intégralRésumé :
Parmi les nombreuses recherches en matière de planification et de contrôle des mouvements pour des applications robotiques, l'humanité n'a jamais atteint un point où les robots seraient parfaitement fonctionnels et autonomes dans des environnements dynamiques. Bien qu'il soit controversé de discuter de la nécessité de ces robots, il est très important d'aborder les problèmes qui nous empêchent de réaliser un tel niveau d'autonomie. Ce travail de recherche tente de résoudre ces problèmes qui séparent ces deux modes de fonctionnement avec un accent particulier sur les incertitudes. Les impossibilités pratiques de capacités de détection précises entraînent une variété d'incertitudes dans les scénarios où le robot est mobile ou l'environnement est dynamique. Ce travail se concentre sur le développement de stratégies intelligentes pour améliorer la capacité de gérer les incertitudes de manière robuste dans les robots humanoïdes et industriels. Premièrement, nous nous concentrerons sur un cadre dynamique d'évitement d'obstacles proposé pour les robots industriels équipés de capteurs de peau pour la réactivité. La planification des chemins et le contrôle des mouvements sont généralement formalisés en tant que problèmes distincts de la robotique, bien qu'ils traitent fondamentalement du même problème. Les espaces de configuration à grande dimension, l'environnement changeant et les incertitudes ne permettent pas la planification en temps réel de mouvement exécutable. L'incapacité fondamentale d'unifier ces deux problèmes nous a amené à gérer la trajectoire planifiée en présence de perturbations et d'obstacles imprévus à l'aide de différents mécanismes d'exécution et de déformation de trajectoire. Le cadre proposé utilise «Stack of Tasks», un contrôleur hiérarchique utilisant des informations de proximité, grâce à un planificateur de chemin réactif utilisant un nuage de points pour éviter les obstacles. Les expériences sont effectuées avec les robots PR2 et UR5 pour vérifier la validité du procédé à la fois en simulation et in-situ. Deuxièmement, nous nous concentrons sur une stratégie pour modéliser les incertitudes des paramètres inertiels d'un robot humanoïde dans des scénarios de tâches d'équilibre. Le contrôle basé modèles est devenu de plus en plus populaire dans la communauté des robots à jambes au cours des dix dernières années. L'idée clé est d'exploiter un modèle du système pour calculer les commandes précises du moteur qui entraînent le mouvement désiré. Cela permet d'améliorer la qualité du suivi du mouvement, tout en utilisant des gains de rétroaction plus faibles, ce qui conduit à une conformité plus élevée. Cependant, le principal défaut de cette approche est généralement le manque de robustesse aux erreurs de modélisation. Dans ce manuscrit, nous nous concentrons sur la robustesse du contrôle de la dynamique inverse à des paramètres inertiels erronés. Nous supposons que ces paramètres sont connus, mais seulement avec une certaine précision. Nous proposons ensuite un contrôleur basé optimisation, rapide d'exécution, qui assure l'équilibre du robot malgré ces incertitudes. Nous avons utilisé ce contrôleur en simulation pour effectuer différentes tâches d'atteinte avec le robot humanoïde HRP-2, en présence de diverses erreurs de modélisation. Les comparaisons avec un contrôleur de dynamique inverse classique à travers des centaines de simulations montrent la supériorité du contrôleur proposé pour assurer l'équilibre du robotAmidst a lot of research in motion planning and control in concern with robotic applications, the mankind has never reached a point yet, where the robots are perfectly functional and autonomous in dynamic settings. Though it is controversial to discuss about the necessity of such robots, it is very important to address the issues that stop us from achieving such a level of autonomy. Industrial robots have evolved to be very reliable and highly productive with more than 1.5 million operational robots in a variety of industries. These robots work in static settings and they literally do what they are programmed for specific usecases, though the robots are flexible enough to be programmed for a variety of tasks. This research work makes an attempt to address these issues that separate both these settings in a profound way with special focus on uncertainties. Practical impossibilities of precise sensing abilities lead to a variety of uncertainties in scenarios where the robot is mobile or the environment is dynamic. This work focuses on developing smart strategies to improve the ability to handle uncertainties robustly in humanoid and industrial robots. First, we focus on a dynamical obstacle avoidance framework proposed for industrial robots equipped with skin sensors for reactivity. Path planning and motion control are usually formalized as separate problems in robotics. High dimensional configuration spaces, changing environment and uncertainties do not allow to plan real-time motion ahead of time requiring a controller to execute the planned trajectory. The fundamental inability to unify both these problems has led to handle the planned trajectory amidst perturbations and unforeseen obstacles using various trajectory execution and deformation mechanisms. The proposed framework uses ’Stack of Tasks’, a hierarchical controller using proximity information to avoid obstacles. Experiments are performed on a UR5 robot to check the validity of the framework and its potential use for collaborative robot applications. Second, we focus on a strategy to model inertial parameters uncertainties in a balance controller for legged robots. Model-based control has become more and more popular in the legged robots community in the last ten years. The key idea is to exploit a model of the system to compute precise motor commands that result in the desired motion. This allows to improve the quality of the motion tracking, while using lower feedback gains, leading so to higher compliance. However, the main flaw of this approach is typically its lack of robustness to modeling errors. In this paper we focus on the robustness of inverse-dynamics control to errors in the inertial parameters of the robot. We assume these parameters to be known, but only with a certain accuracy. We then propose a computationally-efficient optimization-based controller that ensures the balance of the robot despite these uncertainties. We used the proposed controller in simulation to perform different reaching tasks with the HRP-2 humanoid robot, in the presence of various modeling errors. Comparisons against a standard inverse-dynamics controller through hundreds of simulations show the superiority of the proposed controller in ensuring the robot balance
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Qian, Gengjian. « Analyse de sensibilité et robustesse dans le génie industriel : méthodologies et applications aux essais de chocs ». Thesis, Lyon, 2017. http://www.theses.fr/2017LYSE1064/document.
Texte intégralRésumé :
Plus d'un million de personnes meurent dans des accidents sur les routes du monde et beaucoup de millions sont gravement blessés chaque année. Selon les études, ‘Run-Off-Road accidents (ROR)’, c'est-à-dire que le véhicule a au moins une collision avec des équipements routiers, représentent environ 10% des accidents routières, mais 45% de tous les accidents mortels sont des ROR. Les dispositifs de retenue des véhicules (DDR) sont les infrastructures installées sur la route pour fournir un niveau de confinement du véhicule ‘hors de contrôle’. La barrière de sécurité routière est un DDR continu installé à côté ou sur la réserve centrale d'une route pour empêcher les véhicules errants de s'écraser sur les obstacles routiers et de les conserver en toute sécurité. Les résultats statistique montrent que l'existence des barrières peut réduire les morts jusqu'à un facteur de 4 par rapport aux collisions contre d'autres obstacles routiers. Les performances de sauvetage d'un DDR dépendent de la conception de l'appareil. Des normes telles que EN1317 ont normalisé les conditions des essais de chocs sous lesquelles une conception de DDR doit être testée et ont défini les critères pour l'évaluation des performances d'une conception. En fait, un DDR ne puisse pas vraiment être optimisé: il existe des critères multiples pour l'évaluation de la performance d'un DDR et tous les critères ne peuvent pas être optimisés en même temps; les conditions de travail d’un DDR, c'est-à-dire les conditions d'impact d’un DDR avec un véhicule errant, sont nombreuses; les facteurs incertains du DDR peuvent dégrader les performances d'une conception. La thèse vise à définir une approche qui peut servir : l'analyse de sensibilité (AS) et la conception robuste du DDR ; enrichissement des normes existantes dans la conception du DDR. Le cas d'une barrière de sécurité routière est spécifié dans l'étude : une barrière a été testée expérimentalement, le programme Ls-Dyna est utilisé pour la simulation de choc de l'appareil ; en tenant compte des propriétés du modèle de choc, les efficacités de différentes méthodes de l’AS ont été étudiées ; les influences des facteurs critiques dont les incertitudes contribuent le plus à l'instabilité de la barrière ont été quantifiées avec les approches d’AS sélectionnées ; compte tenu des incertitudes des facteurs critiques, l’optimisation robuste de multi-objectif de la barrière est réalisée ; des simulations d'impact de la barrière optimisée ont été effectuées sous des conditions d'impact différentes pour évaluer ses performances dans les véritables accidents. Les approches présentées dans l'article peuvent être utiles pour la conception d'autres DDR ou plus largement d'autres systèmes d'ingénierie complexes. On peut espérer que l'analyse de robustesse et l'analyse de la généralisation (c'est-à-dire l'évaluation de la performance du DDR sous différentes conditions d'impact) du DDR pourraient enrichir les normes de la conception des DDRMore than 1 million people die in crashes on the world’s roads and many millions are seriously injured each year. According to the studies: Run-Off-Road accidents (ROR), i.e. the vehicle run-off the road into the roadside and has at least one collision with either roadside equipment or the roadside itself, “represent about 10% of the total road accidents, while 45% of all fatal accidents are ROR”. Vehicle Restraint Systems (VRS) are the infrastructures installed on the road to provide a level of containment for an errant vehicle. Safety barrier is “continuous VRS installed alongside, or on the central reserve, of a road to prevent errant vehicles from crashing on roadside obstacles, and to retain them safely”. Statistic results show that “the existence of protective barriers on road can reduce fatalities up to a factor of 4 when compared to collisions against other road obstacles.” The life-saving performances of a VRS depend on the design of the device. Standards such as EN1317 normalized the impact conditions under which a design of VRS must be tested by crash tests, and defined the criteria for performance evaluation of a design. While a VRS cannot really be optimized: Multi-criteria exist for performance evaluation of a VRS and all the criteria cannot be optimized in the same time; the impact conditions of the VRS with the errant vehicle are numerous; uncertain factors of the VRS may degrade the performances of a design. The thesis aims to define an approach that can serve: sensitivity analysis (SA) and robust design of the VRS; Enrichment for the existing standards in the design of VRS. The case of a safety barrier is specified in the study: a safety barrier has been test experimentally, the program Ls-Dyna was used for crash simulation of the device; considering properties of the crash model, efficiencies of different SA methods were studied and influences of the critical factors whose uncertainties contribute the most to the instability of the barrier were quantified with the selected SA approaches; considering the uncertainties of the critical factors, Multi-Objective robust optimization of the tested barrier were realized; under different impact conditions, crash simulations of the optimized barrier were carried out to evaluate its performances in the real crash accidents. The approaches presented in the article can be useful for the design of other VRS or more broadly, other complex engineering systems. Hopefully, the robustness analysis and generalization analysis (i.e. performance evaluation of the VRS under different impact conditions) of the safety barrier could enrich the standards for the design of VRS
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Milet, Tomáš. « Grafické intro 64kB s použitím OpenGL ». Master's thesis, Vysoké učení technické v Brně. Fakulta informačních technologií, 2012. http://www.nusl.cz/ntk/nusl-236545.
Texte intégralRésumé :
This thesis deals with the creation of the intro with limited size. This work describes methods for reducing the size of the final application. The main part describes methods for generating graphic content and methods for its animation. It deals with creation of textures and geometry. Another part is aimed on the physical simulation of particle and elastic systems.
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Aum, Ho Sung. « Parameters affecting mechanical collisions ». Thesis, 1992. http://hdl.handle.net/1957/35770.
Texte intégralRésumé :
Even though the elastic deformations that occur during the
impact of colliding bodies may be small in comparison to their actual
dimensions, they play an important role in mechanical collisions.
During the time the bodies are in contact, elastic, friction, and inertia
properties combine to produce a complex variation of sliding and
sticking throughout the contact surface. Detailed analysis of this
interaction is quite tedious, but would seem to be necessary for
accurately predicting the impulse and velocity changes that occur
during contact. However, a considerably-simplified model captures
the essential characteristics of the elastic-friction interaction during
contact, leading to predictions of impulse and velocity changes that
agree well with those of more detailed analyses of a number of
different collisions.
The model's simplicity enables an examination of parameters
that affect a general class of collisions. For planar collisions, the
model contains five dimensionless parameters; the effects of four of
these on the rebound velocity are examined here.
In addition, comparisons are made with a previously-used,
somewhat simpler model, which neglects the tangential compliance in
the region of contact.Graduation date: 1993
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Liu, Pei-De, et 劉培德. « Collision Alert by Discriminating Motion Parameters in Successive Disparity Maps ». Thesis, 2007. http://ndltd.ncl.edu.tw/handle/43669980112599876222.
Texte intégralRésumé :
碩士國立臺灣大學
電機工程學研究所
95
Sensing with stereo camera, intelligent collision alert system can not only detect and display collision hot spots but also estimate the three-dimension spatial information and motion parameters for collision avoidance control. To implement the intelligent collision alert system, the techniques of edge extraction to isolate target objects, generation of edge disparity map to find the spatial information, computational visual attention to find attentive spots, region of interest determination to encompass object areas, object tracking to estimate motion parameters from successive disparity maps, and the strategy to find collision hot spots by according to the distances and motion directions of the target objects are developed and integrated as a whole. Target objects falling in the emergency zone or in the danger zone but approaching the camera are determined as the collision hot spots. In addition to making collision alert and displaying the collision hot spots on the image, the three-dimension spatial information and motion directions are estimated for collision avoidance control. The key techniques are verified with a prototype implementation. Experimental results show that the intelligent collision alert system by stereo camera sensing is feasible and practical for driver assistance of active safety.
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Hwang, Lorraine Joyce. « Teleseismically determined source parameters of several large collision-zone earthquakes ». Thesis, 1991. https://thesis.library.caltech.edu/2773/1/Hwang_lj_1991.pdf.
Texte intégralRésumé :
NOTE: Text or symbols not renderable in plain ASCII are indicated by [...]. Abstract is included in .pdf document.
Understanding earthquake hazards begins with the understanding of the earthquake process itself and its effects in the near source region. Here both ends of the problem are explored. First, source parameters and rupture models for several earthquakes around the circum-Pacific are studied. Second, acceleration spectra are compared to teleseismic data. It is hoped that the extensive teleseismic data base can be used to scale acceleration spectra for large future, earthquakes.
The 7 May 1986 Andreanof Islands earthquake was a large (1.3 x [...] dyne-cm) thrust event (strike 257°, dip 18°, rake 116°) that ruptured a 220 km segment of the Aleutian Arc. The earthquake ruptured bilaterally with the largest moment releasing subevent nucleating 75-90 km west of the epicenter in a region of low aftershock seismicity. At a distance of 100 km, the acceleration spectrum had the same amplitude as that from teleseismic data.
The 20 May (6.4 M[...], NEIC) and 14 November (7.3 M[...], 1.7 x [...] dyne-cm) 1986 Hualien earthquakes occurred on two steeply dipping, reverse faulting events near the Eurasian-Philippine Sea plate boundary. The amplitude of the observed spectra at a distance of 70-80 km is 5 times that from teleseismic data. This is consistent with previous observations. Comparisons between hard and soft rock recording sites indicate that the alluvial valley amplified the strong ground motion between 0.15-1.8 Hz.
The 24 November 1987 Superstition Hills earthquake (8 x [...] dyne-cm) consisted of two spatially distinct subevents with different focal mechanisms at depths between 4 to 8 km. Rupture models along with aftershock, afterslip and geologic data suggest that the northern and southern segments of the Superstition Hills fault behaved differently during this event.
The 1987-88 Gulf of Alaska earthquake sequence consisted of three large, intraplate, strike-slip earthquakes (7.2, 7.8, 7.7 Mw), whose depths extended to 25 km. The data are modeled with multiple subevents with different focal mechanisms. In comparison with other large events, the short durations and rupture lengths of the two largest events illustrate the difference in strength between oceanic and continental lithosphere. Moment release is confined to the epicentral region and/or regions of apparent structural complexities where seismicity trends intersect.
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Liu, Pei-De. « Collision Alert by Discriminating Motion Parameters in Successive Disparity Maps ». 2007. http://www.cetd.com.tw/ec/thesisdetail.aspx?etdun=U0001-1307200714583900.
Texte intégral
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(5931161), Tianyang Wu. « Ion Mobility Spectrometry : Optimization of Parameters in Collision Cross Sections and Trace Detection of Explosives ». Thesis, 2019.
Trouver le texte intégralRésumé :
Ion mobility spectrometry is a powerful technique for the study related to molecule. The work of tow major applications are introduced in this paper. The first application is the optimization of parameters in CCS. The accurate calculation of the collision cross section for multiple molecules is a long-time interested topic in the research for substances detection in micro scale. No reliable analytical approach to calculate the collision cross section has been established to date. Different approaches rely on different mechanism will provide different results in significant extent. This work introduce a method for the determination of parameters in the Lennard Jones potential. Experimental data combined with numerical computation was the fundamental strategy during the optimization of the parameters. In the experiment, electrospray is used as the ion source of IMS while a nebulizer was utilized to electrify the aromatic compounds. New parameters show no less accuracy and equal efficiency while can explain the physical meaning of the collision more clearly. The second application is the trace detection of explosives with very low concentration. The detection of explosives is an important topic in security, while the detection will be difficult due to the low vapor pressure of explosives. In this work, two types of devices are designed for the trace detection of explosives at an extremely low concentration. TNT is selected as the explosives in the experiment. The experiment succeed to reach a sensitivity of 1 part per quintillion, and even find out a linear relationship between the logarithm of TNT concentration and TNT vapor pressure.
29
Wu, Tianyang. « Ion Mobility Spectrometry : Optimization of Parameters in Collision Cross Sections and Trace Detection of Explosives ». Thesis, 2018. http://hdl.handle.net/1805/17956.
Texte intégralRésumé :
Indiana University-Purdue University Indianapolis (IUPUI)Ion mobility spectrometry is a powerful technique for the study related to molecule. The work of tow major applications are introduced in this paper. The first application is the optimization of parameters in CCS. The accurate calculation of the collision cross section for multiple molecules is a long-time interested topic in the research for substances detection in micro scale. No reliable analytical approach to calculate the collision cross section has been established to date. Different approaches rely on different mechanism will provide different results in significant extent. This work introduce a method for the determination of parameters in the Lennard Jones potential. Experimental data combined with numerical computation was the fundamental strategy during the optimization of the parameters. In the experiment, electrospray is used as the ion source of IMS while a nebulizer was utilized to electrify the aromatic compounds. New parameters show no less accuracy and equal efficiency while can explain the physical meaning of the collision more clearly. The second application is the trace detection of explosives with very low concentration. The detection of explosives is an important topic in security, while the detection will be difficult due to the low vapor pressure of explosives. In this work, two types of devices are designed for the trace detection of explosives at an extremely low concentration. TNT is selected as the explosives in the experiment. The experiment succeed to reach a sensitivity of 1 part per quintillion, and even find out a linear relationship between the logarithm of TNT concentration and TNT vapor pressure.
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Chou, Ying-Ru, et 周盈如. « Development and Application of Parameters Fuzzification for The Bus Rear-End Collision Avoidance Warning Algorithm ». Thesis, 2005. http://ndltd.ncl.edu.tw/handle/01628717565486522816.
Texte intégralRésumé :
碩士中華大學
科技管理研究所
93
Vehicle rear-end collision avoidance warning system (RCAWS) or forward collision avoidance warning system (FCAWS) is the system that integrates the advanced detecting technology, auditory, visual or tactile display devices, and rear end collision warning algorithm to provide the timely alert messages to drivers according to different road and traffic conditions. The alert messages can be used to warn drivers to keep safety spacing between the lead vehicle and the following vehicle for avoiding rear end crashes. The effect of safety protection will also be achieved. Since the frequency of bus accidents due to without keeping safety spacing is very high in Taiwan, it has become an important issue of advanced safety bus technology research to develop the bus rear-end collision avoidance warning system concerns bus driver’s driving characteristics. While the rear-end collision avoidance warning system offers great potential to improve automobile safety, beneficial effects depend on the joint performance of the system and the driver psychology and behavior acceptance. By reviewing the developed and developing RCAWS algorithms, driver’s perception reaction time, braking deceleration and stationary vehicle spacing of the warning threshold are three major parameters in the RCAWS algorithm. These parameters influence the timing of warning system opening. The proper combination of these three parameters will be different by different driver psychology-behavior characteristics. This study designed the emergency braking simulation scenario of bus car following driving on the freeway straight road section by utilizing the bus driving simulator. The bus drivers with license that are working in freeway bus companies were invited to do the simulation experiments under this designed driving simulation scenario. The sample data of perception reaction time, braking deceleration and stationary vehicle spacing were collected and analyzed after bus driving simulator experiments. The value range of perception reaction time is from 0.72 seconds to 3.23 seconds. The value range of braking deceleration is from -1.47 meters/square second to -7.25 meters/square second. The value range of stationary vehicle spacing is from 2 meters to 12 meters. This study developed the safety membership function of the three parameters and analyzed the reasonable bus rear-end collision avoidance algorithms with related warning rules. In first algorithm, twenty-seven safety levels of warning distance equation and the related rules were also developed through the analysis of fuzzy operation rules and defuzzification methods. In second algorithm, the -cut was developed to set up reasonable fuzzy warning equation according to different driver characteristics. The results of this study will be a useful basis in developing the rear-end collision avoidance warning system of advanced safety bus.
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Chang, Ting-Wei, et 張婷瑋. « A Study on the Application of Bus Driving Simulator to the Development of Parameters for an Intersection Pedestrian Collision Warning System ». Thesis, 2009. http://ndltd.ncl.edu.tw/handle/13076831174713863084.
Texte intégralRésumé :
碩士中華大學
運輸科技與物流管理學系碩士班
97
Recently, the development of intelligent transportation systems (ITS) in advanced countries has focused on not only the cost-effectiveness but also the usage equity of transportation systems. That is, the intelligence of transportation systems should improve service quality for most road users and meet transportation demand of a few vulnerable individuals such as pedestrians simultaneously to achieve social equity. Utilizing advanced technologies to guarantee safety protection for pedestrians at intersections has become an important issue because intersections are the places where pedestrians easily conflict with vehicles. The purpose of this study is to propose a conceptual design of an intersection bus-pedestrian collision warning system with appropriate detection and warning parameters for bus drivers approaching an intersection. Based on the design concept, bus drivers’ perception-reaction time, emergency deceleration rate of buses, and pedestrian walking speed are defined as the basic parameters. A bus driving simulation is designed and conducted to collect bus drivers’ responses to the suddenly crossing pedestrians at unsignalized intersections or signalized intersections with green interval for parameters analysis. Finally, the warning timings for auditory warnings and visual warnings, the locations for vehicle detectors and pedestrian detectors, and the locations for visual warning devices are developed through a further analysis of the experimental results. According to the experimental results, the generalized warning timings for the voice warning and the VMS display are 6.28 s and 6.07 s, respectively. The shortest distance between the pedestrian detector and the curb is computed as 6.5 m. The computed value for the shortest distance between the vehicle speed detector and the collision point is 61 m. The warning timing for pedestrians is computed as 4.39 s. The locations of the VMS for bus drivers and pedestrians are 50 m and 3 m, respectively. This study also develops warning rules for the intersection bus-pedestrian collision warning system. The system prototype developed in this study will be helpful in the enhancement of safety for pedestrians at intersections.
32
McDonald, Daniel. « Statistical moments of the multiplicity distributions of identified particles in Au+Au collisions ». Thesis, 2013. http://hdl.handle.net/1911/72004.
Texte intégralRésumé :
In part to search for a possible critical point (CP) in the phase diagram of hot nuclear matter, a beam energy scan was performed at the Relativistic Heavy-Ion Collider at Brookhaven National Laboratory. The Solenoidal Tracker at RHIC (STAR) collected Au+Au data sets at beam energies, √sNN , of 7.7, 11.5, 19.6, 27, 39, 62.4, and 200 GeV. Such a scan produces hot nuclear matter at different locations in the phase diagram. Lattice and phenomenological calculations suggest that the presence of a CP might result in divergences of the thermodynamic susceptibilities and correlation lengths. The statistical moments of the identified-particle multiplicity distributions directly depend on both the thermodynamic susceptibilities and correlation lengths, possibly making the shapes of these multiplicity distributions sensitive tools for the search for the critical point. The statistical moments of the multiplicity distributions of a number of different groups of identified particle species were analyzed. Care was taken to remove a number of experimental artifacts that can modify the shapes of the multiplicity distributions. The observables studied include the lowest four statistical moments (mean, variance, skewness, kurtosis) and some products of these moments. These observables were compared to the predictions from several approaches lacking critical behavior, such as the Hadron Resonance Gas model, mixed events, (negative) binomial, and Poisson statistics. In addition, the data were analyzed after gating on the event-by-event antiproton-to-proton ratio, which is expected to more tightly constrain the event trajectories on the phase diagram.
33
Fahed, Rémi. « Étude observationnelle de la collision des vents dans les systèmes Wolf-Rayet+O ». Thèse, 2011. http://hdl.handle.net/1866/6240.
Texte intégralRésumé :
Nous présentons les résultats de trois campagnes d'observation d'un mois chacune dans le cadre de l'étude de la collision des vents dans les systèmes binaires Wolf-Rayet + OB. Ce travail se concentre sur l'étude des objets de l'hémisphère sud n'ayant jamais encore fait l'objet d'études poussées dans ce contexte. À cela, nous avons ajouté l'objet archétype pour ce type de systèmes : WR 140 (WC7pd + O5.5fc) qui a effectué son dernier passage périastre en janvier 2009. Les deux premières campagnes (spectroscopiques), ont permis une mise à jour des éléments orbitaux ainsi qu'une estimation de la géométrie de la zone de collision des vents et d'autres paramètres fondamentaux des étoiles pour 6 systèmes binaires : WR 12 (WN8h), 21 (WN5o+O7V), 30 (WC6+O7.5V), 31 (WN4o+O8), 47 (WN6o+O5) et 140. Une période non-orbitale courte (probablement reliée à la rotation) a également été mesurée pour un des objets : WR 69 (WC9d+OB), avec une période orbitale bien plus grande.
La troisième campagne (photométrique) a révélé une variabilité étonnamment faible dans un échantillon de 20 étoiles WC8/9. Cela supporte l'idée que les pulsations ne sont pas courantes dans ce type d'étoiles et qu'il est peu probable que celles-ci soient le mécanisme dominant de formation de poussière, suggérant, par défaut, le rôle prédominant de la collision des vents.We present the results from three month-long observational campaigns related to WR+O colliding-wind binaries. This work focuses on southern-hemisphere systems that have not yet been previously studied in this context. To this we add the northern archetype colliding-wind system WR 140 (WC7pd + O5.5fc), which recently suffered another active periastron passage in 2009 January. The first two (spectroscopic) campaigns allowed us to update the orbital elements and to constrain the geometry of the colliding wind region and other fundamental parameters, for 6 binary systems: WR 12 (WN8h), WR 21 (WN5o+O7V), WR 30 (WC6+O7.5V), WR 31 (WN4o+O8), WR 47 (WN6o+O5) and WR 140. A short non-orbital (probably rotational) period was also detected in the WR component of one of our objects, WR 69 (WC9d+OB), with a much longer orbital period. The third (photometric) campaign revealed a surprisingly low level of variability in our sample of 20 WC8/9 stars. This supports the idea that pulsations are not very frequent in this type of star and are unlikely to be the main mechanism for dust formation, suggesting, by default, a predominant role of wind-wind collision.
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Procházka, Jiří. « Pružné srážky protonů s protony při vysokých energiích ». Doctoral thesis, 2017. http://www.nusl.cz/ntk/nusl-379877.
Texte intégralRésumé :
The proton, one of the basic constituents of atoms, was discovered around 1920. Its structure has been intensively studied since that time mainly with the help of proton- proton collision experiments. Main progress has started when corresponding experiments at the world's first hadron collider ISR at CERN which ran from 1971 to 1984 were performed. The understanding of the structure and interactions of this subatomic particle protons has been, however, rather incomplete. Only some very general models have been available especially in the case of higher collision energies when very different kinds of collisions have existed. Some very simplifying assumptions of unclear physical meaning have been then involved in models concerning elastic processes. The influence of these assumptions on physical interpretation has started to be studied and some progress has been made when the eikonal model has been proposed, i.e., the dependence of elastic collisions on corresponding impact parameter values has been taken into account from the beginning. However, even if some new results have been obtained many unanswered questions have remained. For example, the collision process has been denoted generally as probabilistic but corresponding probabilities have not been sufficiently defined and determined. The given thesis contains,...
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Procházka, Jiří. « Pružné srážky protonů s protony při vysokých energiích ». Doctoral thesis, 2018. http://www.nusl.cz/ntk/nusl-389827.
Texte intégralRésumé :
Under the influence of standardly used (however, very simplified) description of Coulomb-hadronic interference proposed by West and Yennie (1968) the protons have been interpreted as "transparent" objects; elastic collisions have been interpreted as more central than inelastic ones. This property may be hardly put in agreement with the fact that in the majority of hadronic collisions many different particles have been created at high energies. Using the more general eikonal model it will be shown that the protons may be interpreted in agreement with usual conception; elastic processes being more peripheral than inelastic ones. The contemporary TOTEM experiment at the LHC accelerator in CERN devoted to measurement of elastic pp scattering and diffractive processes at the highest ever reached energies will be described. The eikonal model will be explained to greater details, generalized and applied to experimental data of elastic pp collisions under different assumptions at 52.8 GeV (older ISR data measured at CERN) and also at much higher energy of 8 TeV (new TOTEM data). The impact of different assumptions on determination of several quantities specifying hadron interaction will be studied. Mainly the assumptions influencing behaviour of elastic collisions in dependence on impact parameter of colliding...