Academic literature on the topic 'Isolux diagram'

The stationary-state behaviour of the simple autocatalytic models: quadratic autocatalysis A + B → 2B; rate = k 1 ab ; cubic autocatalysis A + 2B → 3B; rate = k 1 ab 2 , in a well stirred, open system (isothermal c. s. t. r.) is determined via singularity theory methods. These methods allow all of the possible patterns for the dependence of the stationary-state extent of conversion x on the residence time Da (i. e. the x —Da bifurcation diagrams) to be identified and located. The cubic rate law has a cusp singularity, separating diagrams with a unique dependence of x on Da from those which display a simple S-shaped hysterisis loop with multiple stationary states. This behaviour is qualitatively similar to that shown by a simple exothermic reaction in an adiabatic c. s. t. r. (i. e. the two systems are contact equivalent). If the autocatalyst is not infinitely stable but instead undergoes a simple decay B → C; rate = k 2 b , a wider range of bifurcation diagrams is possible, with isolas or mushroom patterns. These arise as the system is ‘unfolded’ from its winged cusp singularity by varying parameters such as the catalyst lifetime and inflow concentration. It is shown that these are also the only patterns possible for a generalized order of autocatalysis, i. e. for a rate proportional to ab m , with m taking any value greater than one, integral or non-integral. The ranges of the above parameters over which the different responses are found are also given analytically for the general m . These parameters cannot, however, give a complete unfolding, so certain additional bifurcation diagrams that are found for the exothermic reaction in a non-isothermal, non-adiabatic reactor (which also has a winged-cusp singularity) are not found in the autocatalytic system.

This master’s thesis deals with the possibilities of illumination of motor vehicles. Thesis is divided into two sections, from which the first discusses precisely the possibilities of lighting of motor vehicles at the present time. What are the modern lighting techniques, that can be found on the market and what is their impact on safety enhancement in road traffic. Second section is about the practical measurement of low and high beam afterglow. This measurement is being compared between two types of headlamps, namely halogen headlights and xenon headlights. Part of the measurement is as well measurement of illumination intensity precisely for these headlights. The output of measurement is the creation of own illumination intensity diagrams and afterglow diagrams of particular headlights, in comparison to isolux diagrams provided by the headlights manufacturer. Consequently are solved the issues about utilization of the isolux diagrams in expert praxis.

Le calcul géométrique en modélisation et en CAO nécessite la résolution approchée, et néanmoins certifiée, de systèmes polynomiaux. Nous introduisons de nouveaux algorithmes de sous-division afin de résoudre ce problème fondamental, calculant des développements en fractions continues des coordonnées des solutions. Au delà des exemples concrets, nous fournissons des estimations de la complexité en bits et des bornes dans le modèle de RAM réelle. La difficulté principale de toute méthode de résolution consiste en les points singuliers isolés. Nous utilisons les systèmes locaux inverses et des calculs numériques certifiés afin d'obtenir un critère de certification pour traiter les solutions singulières. Ce faisant, nous sommes en mesure de vérifier l'existence et l'unicité des singularités d'une structure de multiplicité donnée. Nous traitons deux principales applications géométriques. La première: l'approximation des ensembles semi-algébriques plans, apparaît fréquemment dans la résolution de contraintes géométriques. Nous présentons un algorithme efficace pour identifier les composants connexes et pour calculer des approximations polygonales et isotopiques à l'ensemble exact. Dans un deuxième temps, nous présentons un cadre algébrique afin de calculer des diagrammes de Voronoi. Celui-ci sera applicable à tout type de diagramme dans lequel la distance à partir d'un site peut être exprimé par une fonction polynomiale à deux variables (anisotrope, diagramme de puissance etc). Si cela n'est pas possible (par exemple diagramme de Apollonius, VD des ellipses etc), nous étendons la théorie aux distances implicitement données.

Abstract A new vibration absorbing device is introduced for large flexible structures. The bifurcation diagrams obtained for the averaged system, indicate that the system loses stability via two distinct routes. One leading to a saddle-node bifurcation, normally associated with the jump phenomena. The second instability is due to the Hopf bifurcation, that results in amplitude modulated motion of the oscillator. A parameter range has been identified where these bifurcations coalesce. This phenomenon is a strong indicator of existence of homoclinic orbits. In addition to the regular solution branches, that bifurcate from the zero solution, the system also possesses isolated solutions (the so-called “isolas”) that form isolated loops bounded away from zero. As the forcing amplitude is varied, the isolas appear, disappear or coalesce with the regular solution branches. The response curves indicate that the column amplitude shows saturation. The pendulum acts as a vibration absorber over a range of frequency where the column response is saturated. However, there is also a frequency range over which a reverse flow of energy occurs, where the pendulum shows reduced amplitude at the cost of large amplitudes of the column.