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Modeling Permissive Left-Turn Gap Acceptance Behavior at Signalized IntersectionsZohdy, Ismail Hisham 04 December 2009 (has links)
The research presented in this thesis, studies driver gap acceptance behavior for permissive left turn movements at signalized intersections. The thesis attempts to model the gap acceptance behavior using three different approaches, a deterministic statistical approach, a stochastic approach, and a psycho-physical approach. First, the deterministic statistical modeling approach is conducted using logistic regression to characterize the impact of a number of variables on driver gap acceptance behavior. The variables studied are the gap duration, the driver's wait time in search of an acceptable gap, the time required to travel to clear the conflict point, and the rain intensity. Considering stochastic gap acceptance, two stochastic approaches are compared, namely: a Bayesian and a Bootstrap approach. The study develops a procedure to model stochastic gap acceptance behavior while capturing model parameter correlations without the need to store all parameter combinations. The model is then implemented to estimate stochastic opposed saturation flow rates. Finally, the third approach uses a psycho-physical modeling approach. The physical component captures the vehicle constraints on gap acceptance behavior using vehicle dynamics models while the psychological component models the driver deliberation and decision process. In general, the three proposed models capture gap acceptance behavior for different vehicle types, roadway surface conditions, weather effects and types of control which could affect the driver gap acceptance behavior. These findings can be used to develop weather responsive traffic signal timings and can also be integrated into emerging IntelliDrive systems. / Master of Science
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En undersökning om möjligheterna att använda återanvändningsbara pallband till enhetslaster omlastade till träpallar. / An investigation of the possibility to use reusable pallet strapping for unit loads reloaded to wooden pallets.Björk, Tomas January 2007 (has links)
<p>En undersökning om möjligheterna att använda återandvändningsbara pallband och de ekonomiska förutsättningarna för detta. En genomsökning av vad som finns på marknaden. Beräkning av de krafter som enhetslasten kan utsätta pallbanden för. Utveckling av egna förslag till återanvändningsbart pallband med snabbspänne och bandning på tre sidor. En översikt av de positiva och negativa effekter som blir vid ett byte från dagens bandning med PP-band till ett återanvändningsbart pallband</p> / <p>An investigation of the possibility to use reusable strapping and the economic conditions for this. Going trough what exist on the market. Calculation of the forces that the unit load can expose the strapping for. Developing of own suggestions for reusable strapping with quick buckle and strapping on three sides. A short look at the positive and negative effects that comes from a change from today’s strapping with PP-strap to a reusable strapping.</p>
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Contrainte biomécanique unilatérale versus contrainte biomécanique bilatérale : rééquilibrage des acapacités fonctionnelles et amélioration de la performance dans une tâche locomotrice / Unilateral biomechanical constraint versus bilateral biomechanical constraint : Rebalancing of functional capacities and improvement of performance on locomotive taskDelafontaine, Arnaud 12 December 2013 (has links)
Dans la littérature, les résultats, dans le domaine de la rééducation neurologique des patients hémiplégiques, montraient que la performance motrice du membre atteint était améliorée lorsque les deux membres homolatéraux étaient mobilisés dans des mouvements symétriques. Il a alors été suggéré que le système nerveux avait plus de facilité à adapter une commande bilatérale symétrique, qu’une commande bilatérale asymétrique.L’objet des travaux dans cette thèse est de tester la généralité de ces résultats dans le cas du processus d’initiation de la marche (IM). Le handicap est simulé par une hypomobilité de la cheville, induite avec strapping et orthèse unilatéralement ou bilatéralement. Les résultats montrent que, dès la présence d’une contrainte, la biomécanique et les activités électromyographiques, des phases de préparation posturale et d’exécution du processus d’IM, sont modifiées. De plus, la performance motrice est également perturbée. Toutefois, il apparaît des différences « locales » selon où s'applique la contrainte. Un résultat est à souligner tout particulièrement : comme pour les patients hémi-handicapés, la performance motrice (i.e. vitesse du centre des masses à la fin du premier pas) est supérieure dans la condition « contrainte bilatérale i.e. hypomobilité des deux chevilles » versus « contrainte unilatérale i.e. hypomobilité du pied d’appui ». L’ensemble des résultats est discuté dans le cadre des processus d’adaptation de la commande motrice face aux contraintes biomécaniques unilatérales et bilatérales induites sur les appuis. En d'autres termes, tout se passe comme si un rééquilibrage des capacités fonctionnelles s’opère, permettant ainsi de générer une meilleure performance motrice. Enfin, les résultats permettent d’envisager des perspectives dans le domaine de la rééducation fonctionnelle. / In the literature, the rehabilitation of hemiplegic patients showed that motor performance of the affected limb is improved when both limbs are mobilised in a symmetrical movement. It has been suggested that it was easier for the nervous system to adapt to symmetrical bilateral command. The aim of this dissertation is to test the validity of these results in gait initiation (GI). Handicap was simulated by means of blocking the ankle unilaterally or bilaterally with a strap or orthosis.Results showed that in the presence of a constraint, electromyographic activity and the kinematics of both postural preparation and step execution phase of GI declined. Furthermore, the motor performance was also perturbed.However, « Local » differences appeared according to the localisation of the constraint, reflecting the adaptation of the motor command. Nonetheless, a result needs to be particularly underlying.Like in hemi-handicapped patients, the motor performance (i.e. centre of mass velocity at the end of the first step) was higher in « bilateral constraint, hypomobility on both ankles » versus « unilateral constraint, hypomobility on stance ankle ».In the dissertation, the results are discussed in terms of the adaptation of the motor command of unilateral and bilateral induced biomechanical constraint. More specifically, we discuss how rebalancing the functional capacity of both legs should allow to increase motor performance. These results put forward new perspectives in the domain of functional rehabilitation.
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En undersökning om möjligheterna att använda återanvändningsbara pallband till enhetslaster omlastade till träpallar. / An investigation of the possibility to use reusable pallet strapping for unit loads reloaded to wooden pallets.Björk, Tomas January 2007 (has links)
En undersökning om möjligheterna att använda återandvändningsbara pallband och de ekonomiska förutsättningarna för detta. En genomsökning av vad som finns på marknaden. Beräkning av de krafter som enhetslasten kan utsätta pallbanden för. Utveckling av egna förslag till återanvändningsbart pallband med snabbspänne och bandning på tre sidor. En översikt av de positiva och negativa effekter som blir vid ett byte från dagens bandning med PP-band till ett återanvändningsbart pallband / An investigation of the possibility to use reusable strapping and the economic conditions for this. Going trough what exist on the market. Calculation of the forces that the unit load can expose the strapping for. Developing of own suggestions for reusable strapping with quick buckle and strapping on three sides. A short look at the positive and negative effects that comes from a change from today’s strapping with PP-strap to a reusable strapping.
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The Effect of Steel Strapping Tensioning Technique and Fibre-Reinforced Polymer on the Performance of Cross-Laminated Timber Slabs Subjected to Blast LoadsLopez-Molina, America Maria 09 October 2018 (has links)
Engineered wood products (EWP) are becoming extremely popular and a viable material option for the construction of residential, commercial, and hybrid buildings. Cross-laminated timber (CLT) is among one of the many EWP available in North America, which can be utilized for many different applications such as: walls, floors, and roofs. Despite the available requirements in the Canadian blast design standard (CSA, 2012) with regard to the design of wood structures, there are currently no provisions on how to retrofit timber structures to improve their performance when subjected to blast loads. The current study is aimed at investigating the effect of different retrofitting alternatives in order to improve the overall behaviour of CLT when exposed to out-of-plane bending.
The experimental program examined the behaviour of seventeen reinforced CLT slabs. Testing was conducted at the University of Ottawa by means of a shock tube capable of simulating high strain rates similar to those experienced during a blast event. The current study was divided into two phases. The first consisted of CLT slabs retrofitted with steel straps where strap spacing, location, and order of installation was investigated. The second phase focused on the development of dynamic properties of CLT panels when reinforced with GFRP. Lay-up configuration and fabric orientation were among the parameters explored.
The results from the experimental program show that reinforcing the panels with steel straps had minimal effect on the ultimate strength, but significant levels of post peak resistance and ductility was achieved. The horizontal straps were able to restrict the failure to small regions and to promote flexural failure by preventing rolling shear failure. It also eliminated flying debris and enhanced the ultimate strength, stiffness as well as ductility. Applying GFRP layers enhanced the overall behaviour of the slab resulting in a significant increase in peak resistance, ductility, and stiffness when compared to the dynamic results of an unretrofitted panel. The post peak resistance was also greatly improved. In particular, applying stacked quadraxial lay-up configuration significantly improved the ductility and resulted in the greatest post peak resistance. The effect of steel straps on damaged and retrofitted was relatively minimal, and only partial recovery of the resistance and the stiffness was achieved. GFRP with full confinement yielded better performance compared to the unretrofitted and undamaged counterpart. More work is needed to quantify the benefits of using GFRP in these applications.
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