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Towards High Quality Video Streaming over Urban Vehicular Networks Using a Location-aware Multipath SchemeWang, Renfei 27 June 2012 (has links)
The transmitting of video content over Vehicular Ad Hoc Networks (VANETs) faces a great number of challenges caused by strict QoS (Quality of Service) requirements and highly dynamic network topology. In order to tackle these challenges, multipath forwarding schemes can be regarded as potential solutions. However, route coupling effect and the path length growth severely impair the performance of multipath schemes. In this thesis, the current research status about video streaming over VANETs as well as multipath transmissions are reviewed. With the demand to discover a more suitable solution, we propose the Location-Aware Multipath Video Streaming (LIAITHON+) protocol to address video streaming over urban VANETs. LIAITHON+ uses location information to discover relatively short paths with minimal route coupling effect. The performance results have shown it outperforms the underlying single path solution as well as the node-disjoint multipath solution. In addition, the impact of added redundancy on the multipath solution is investigated through LIAITHON+. According to the results, added redundancy has a different impact depending on the data rate.
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Rapid transit routing in Winnipeg: determining factors for corridor selectionProkopanko, Adam 06 April 2017 (has links)
Past practices for determining the routes of bus rapid transit (BRT) corridors in Winnipeg, Manitoba, Canada have largely relied upon comparisons of quantitative factors. This research recommends qualitative factors to be incorporated into the process in order to present a more complete evaluation of proposed transit routes. Key Winnipeg informants were interviewed from three groups: transit officials, planners, and developers. Each group has a vested interest in the establishment of new BRT corridors and the construction of transit-oriented development (TOD) around the stations. Informants from Ottawa were interviewed to provide insights from another city having long-standing rapid transit development. The research identified eleven factors that should be taken into consideration when evaluating and selecting the routes for BRT corridors in Winnipeg. A framework of recommendations was developed, with the two foundational factors of transportation value and long-term city-building providing a basis to expand on using transit, development, and planning factors. / May 2017
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Sound and Meaning Components during Speech Comprehension of Mandarin CompoundsJi, Sunjing, Ji, Sunjing January 2016 (has links)
Under the framework of dual-route theory of speech comprehension, two neurological routes are simultaneously active during speech decoding, the dorsal stream and the ventral stream. The dorsal stream is argued to be a sound processor whereas the ventral stream is a meaning processor, hence in cognitive terms, they are called the sound component and the meaning component respectively. Hypotheses concerning the processing speed and response accuracy of these two cognitive components were tested on compound words in Modern Mandarin Chinese. Four experiments were run contrasting, the sound-based task and the meaning-based task, corresponding to each of the two cognitive components. In Experiment 1 and 2, the Task effect was tested on one set of words in which the word-level and word-initial-syllable frequencies were controlled. In Experiment 3 and 4, the Task effect was tested on a different set of words in which semantic transparency was controlled. Multiple regression analyses integrating the data collected in Experiment 1-4 were conducted to test which language theory was preferred, the probability-based theory, the rule-based theory or the integrative theory. The probability-based theory suggests that speech comprehension of compound words relies only on the probability distribution of linguistic units. The rule-based theory suggests that speech comprehension of compound words relies only on phrase-structural rules. The integrative theory suggests that speech comprehension of compound words relies on both the probabilities of linguistic units and phrase-structural rules. It was suggested that the integrative theory explains the data best, but further data testing is needed to confirm this hypothesis. The results of the present study provide evidence for functional trade-off of the sound and meaning components, garden path effects during parsing opaque words and the possibility of the role of a mirror system in human speech comprehension.
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Performance of map matching and route tracking depending on the quality of the GPS dataHouda, Prokop January 2016 (has links)
Satellite positioning measurements are never perfectly unbiased. Due to multiple types of errors affecting the signal transmission through an open space and urban areas each positioning measurement contains certain degree of uncertainty. Satellite signal receivers also do not receive the signal continuously, but the localization information is received discretely. Sampling rate and positioning error provide uncertainty towards the various positioning algorithms used in localization, logistics and in intelligent transport systems applications. This thesis examines the effect of positioning error and sampling rate on geometric and topological map matching algorithms and on the precision of route tracking within these algorithms. Also the effects of the different network density on the performance of the algorithms are evaluated. It also creates the platform for simulation and evaluation of map matching algorithms. Map matching is the process of attaching the initial positioning measurement to the network. A number of authors presented their algorithms during past decades, which shows how complex topic the map matching is, mostly due to the changing environmental and network conditions. Geometric and topological map matching algorithms are chosen, modelled and simulated and their response to the different input combinations is evaluated. Also the recommendations for possible ITS applications are carried out in terms of proposed requirements of the receiver. The results confirm general expectation that the map matching overall improves the initial position error and that map matching serves as a form of error mitigation. Also the correlation between the increase of the original positioning error and the increase of the map matching error is universal for all the algorithms in the thesis. But the comparison of the algorithm also showed large differences between the topological and geometric algorithms and their ability to cope with distorted input data. Whereas topological algorithms were clearly performing better in scenarios with smaller initial error and smaller sampling rate, geometric matching proves to be more effective in heavily distorted or very sparsely sampled data set. That is caused mostly by the ability to easily leave the wrongly mapped position which is in these situations comparative advantage of simple geometric algorithms. Following work should concentrate on involving even more algorithms into the comparison, which would produce more valuable results. Also the simulation of the errors using the error magnitude simulation with known an improved error modelling could increase the generalization of the results.
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Amélioration de la biodisponibilité orale du docétaxel au moyen de systèmes nanoparticulaires / Improvement of oral bioavailability of docetaxel by association to polymeric nanoparticlesMazzaferro, Silvia 12 December 2011 (has links)
Rendre possible l'administration orale du docétaxel (Dtx), un puissant agent anticancéreux administré par voie intraveineuse, représente un défi important en cancérologie. Disposer de formulations administrables par voie orale, moins toxiques et mieux tolérées, représenterait une avancée majeure au plan clinique. Toutefois, plusieurs études ont montré que la très faible biodisponibilité du Dtx par voie orale résulte simultanément de : (i) sa faible solubilité aqueuse, (ii) son faible passage transépithélial au niveau intestinal, (iii) son efflux par les pompes d’efflux (P-gp) et son métabolisme par le cytochrome P450. Nous avons conçu une formulation capable de répondre simultanément à ces différents problèmes. Ainsi, nous avons tout d’abord fait appel aux cyclodextrines (CDs) pour augmenter la solubilité apparente du Dtx. La complexation du Dtx avec la méthyl-β-CD a permis d’augmenter la solubilité apparente du Dtx d’environ 5000 fois. Ce complexe a ensuite été associé à des nanoparticules(NPs) polymères composées d’un coeur de poly(cyanoacrylate d’alkyle) et recouvert en surface de chitosane thiolé afin de leur conférer des propriétés mucoadhésives et de diminuer localement le métabolisme. Ces NPs ont montré in vitro et ex vivo leur capacité à arriver intactes au niveau de l’intestin, d’y adhérer et de libérer le Dtx de manière contrôlée dans le temps, et finalement d’améliorer son absorption intestinale. Une évaluation de la toxicité de cette formulation vis-à-vis de la muqueuse intestinale suggère que l’encapsulation du Dtx dans les NPs assure une certaine protection de la muqueuse. Au final, la formulation orale proposée offre en perspective la possibilité de moduler la dose administrée, donc d’ajuster finement la posologie et finalement d’offrir au corps médical et aux patients les bénéfices d’une thérapie personnalisée. / Docetaxel (Dtx) is an anticancer drug widely used in therapy. However, severe allergic reactions and peripheral neurotoxicity are caused by the intravenous administration of the commercial formulation Taxotere®, requiring thus the oral administration of dexamethasone and antihistamine before infusion. In this context, there is an urgent need to design new orally administered Dtx formulations to reduce these side effects and improve the patient’s qualityof life. Dtx belongs to the Class IV of the Biopharmaceutical Classification System, which comprises substances with both low solubility in aqueous fluids and low apparent intestinal permeability. This represents a major drawback when foreseeing oral delivery. Moreover, Dtx has been shown to be substrate of biological transporters and/or metabolized in the intestinal barrier. We designed a formulation able to overcome these different problems. First of all, we solved the low solubility problem by using cyclodextrin (CDs). The complexation of Dtx with the Methyl-ß-CD allowed increasing the apparent solubility of the Dtx about 5000 times. This complex was then associated to polymeric core-shell nanoparticles (NPs) based on poly(isobutyl cyanoacrylate) coated with thiolated chitosan. Among the characteristics of this system, mucoadhesion properties are the most important for an oral administration. The presence of the positively charged chitosan chains, and the thiol groups at the surface allow NPs to adhere to the mucus layer. In vitro and ex vivo experiments showed that these NPs were able to ensure a time-controlled release of Dtx and to improve its absorption at the intestinal level. An evaluation of the local intestinal toxicity of this formulation suggests that the encapsulation of Dtx into polymeric NPs had a protective effect allowing a preservation of the mucosa integrity. The further step will be to confirm by in vivo studies if this kind of nanoparticles is able to enhance the bioavailability of Dtx allowing to display an anti-tumor activity.
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Understanding travelers' route choice behavior under uncertaintySikka, Nikhil 01 May 2012 (has links)
The overall goal of this research is to measure drivers' attitudes towards uncertain and unreliable routes. The route choice modeling is done within the discrete choice modeling framework and involved use of stated preference data. The first set of analysis elicits travelers' attitudes towards unreliable routes. The results of the analysis provide useful information in relation to how commuters value the occurrence/chances of experiencing delay days on their routes. The frequency of days with unexpected delays also measures the travel time reliability in a way that is easy to understand by day-to-day commuters. As such, behaviorally more realistic values are obtained from this analysis in order to capture travelers' attitudes towards reliability. Then, we model attitudes toward travel time uncertainty using non-expected utility theories within the random utility framework. Unlike previous studies that only include risk attitudes, we incorporate attitudes toward ambiguity too, where drivers are assumed to have imperfect knowledge of travel times. To this end, we formulated non-linear logit models capable of embedding probability weighting, and risk/ambiguity attitudes. A more realistic willingness to pay structure is then derived which takes into account travel time uncertainty and behavioral attitudes. Finally, we present a conceptual framework to use a descriptive utility theory, i.e. cumulative prospect theory in forecasting the demand for a variable tolled lane. We have highlighted the issues that arise when a prescriptive model of behavior is applied to forecast demand for a tolled lane.
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Rol van skoolbestuur in die implementering van 'n effektiewe dissiplinebeleid op laerskoolvlak in die Suid-Kaap / The role of school management in the implementation of an effective discipline policy at primary schools in the Southern CapeGroenewald, Sharlton Delmaine 11 September 2019 (has links)
Text in Afrikaans, with abstracts in Afrikaans, English and Xhosa / Dissipline in skole en leerders se uitslae het sedert 1994 baie verswak. Aanranding op opvoeders haal daagliks die nuus wat 'n swak beeld van die stand van onderwys in Suid-Afrika die wêreld instuur. Hierdie studie het die rol wat die skoolbestuurspanne kan doen om 'n effektiewe dissiplinebeleid in plek kan stel ten einde die gedrag van die leerders te verbeter, ondersoek. Die studie het bevind dat die skole dissiplinebeleide aangekoop het wat deur 'n eksterne maatskappy saamgestel is. Die opvoeders, ouers en leerders het geen aandeel in hierdie beleid nie en daarom neem hulle nie eienaarskap daarvan nie. Dit het ook aan die lig gekom dat die opvoeders verskillende metodes, sommige selfs onwettig, gebruik om leerders te straf. Hulle fokus op straf in plaas daarvan om die gedrag van die leerders te herstel. Die studie doen aanbevelings oor wat die skoolbestuurspan kan doen en gee riglyne vir die opstel van 'n effektiewe dissiplinebeleid. / The systemic test results shows that since 1994, discipline in schools and amongst learners has drastically deteriorated. Assaults on educators on a daily basis reach the news, which leaves a bad image to the world on the state of education in South Africa.
This study investigates the role that school management teams can play to put an effective discipline policy in place to improve the behaviour of learners. The study found that schools have acquired policies on school discipline that were developed by an external company. Educators, learners and parents were not involved in the development thereof and for this reason they do not take ownership of it.
It has come to light that educators use different methods, sometimes even unethical and illegal, to discipline learners. They focus on discipline (punitive) instead of trying to correct the behaviour of the learner (remedial).
The study gives recommendations on what school management teams can do with guidelines on how to develop an effective discipline policy. / Iziphumo zibonisa ukuba ukususela ngo-1994 ukuqeqeshwa ezikolweni kwaye abafundi baye bahlaselwa kakhulu. Ukuhlaselwa kootitshala kwimihla ngemihla kufikelela kwiindaba ezishiya umfanekiso ombi kwihlabathi kwimfundo eMzantsi Afrika.Olu pho nonongo luphanda iqela lokulawula isikolo lingalidlala ukubeka umgaqo-nkqubo osebenzayo wokuphucula ukuziphatha kwabafundi. Olu pho nonongo luye lwabonisa ukuba izikolo zifumene imigaqo-nkqubo yokuqeqeshwa kwesikolo eyenziwe yinkampani yangaphandle. Ootitshala, abafundi nabazali abazange bathathe inxaxheba ekuphuhlisweni kwayo ngenxa yeso sizathu abakhange bawuthathe ubunini bayo.
Kwaye kwacaca ukuba ootitshala basebenzisa iindlela ezihlukeneyo, ngamanye amaxesha nangona zingekho mthethweni, ekuqeqeshweni labafundi. Zijolise ekuqeqesheni (isigwebo) endaweni yokuzama ukulungisa ukuziphatha komfundi (ukulungiswa).Uphononongo unikeza iingcomo malunga naziphi iikomiti zolawulo lwesikolo ezinokukwenza nezikhokelo malunga nokuphuhlisa umgaqo-nkqubo osebenzayo. / Educational Management and Leadership / M. Ed. (Education Management)
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Routing Distribution and Selection Based on Resource Management in Heterogeneous Mobile Wireless NetworksJian, Ming-shen 28 August 2007 (has links)
In wireless ad hoc networks, the resources such as bandwidth, power, computing ability, etc., for end users are limited by the environments and hardware. In addition, the mobility of each user is different. Furthermore, the varied wireless networks with different properties such as transmission rate, coverage, power and protocols make it rarely difficult to establish and maintain the communications through the multiple intermediate nodes which are mobile devices. This dissertation will focus on the following three issues:
1. Most homogeneous wireless networks only considering one or less resources of the mobile device can not select and distribute the routes. In addition, it can cause the load of the intermediate nodes to increase.
2. The various wireless networks have different characteristics of resources. The route selection and distribution algorithms proposed before in homogeneous wireless networks are not adapted for the heterogeneous wireless networks.
3. Most route selection and distribution algorithms are designed for specific type of wireless environments (such as only for proactive type or reactive type). For different environment and different mobility, its cost will be different. To allow an environment-aware based adaptive management for heterogeneous wireless networks with different characteristics of resources becomes an important issue.
In homogeneous wireless ad hoc networks, the resources of the mobile devices such as bandwidth, power, computing ability, etc., are limited and different by the environments and hardware. To evaluate the individual resource of each mobile device, the route distribution and selection algorithm considering the multiple resource variations in wireless ad hoc networks is proposed. First, the evaluation and management for individual resource of each mobile device such as bandwidth, power, and computing ability, are proposed. Second, according to the proposed algorithm, a mobile device can be estimated whether it supports the QoS or not. In addition, these resources evaluation results are transformed as the bottleneck resource information. At last, according to the bottleneck resource information of all the found routes, the route distributed through different intermediate nodes with most resources is selected for load distribution and balance.
Considering the wireless network infrastructure today including 3G wireless communication, IEEE 802.11 wireless local area network, and wireless ad hoc networks, the characteristics such as transmission rates, bandwidth, power consumption, and transmission range of these wireless structures are not the same. In other words, the routing selection algorithm for homogeneous wireless networks may not be flexible for another wireless network. In this thesis, these different wireless network structures are integrated into one heterogeneous wireless network. Individual characteristics such as transmission rates, bandwidth, power consumption, and transmission range of these wireless structures are evaluated. According to the adaptive resource evaluation and route selection algorithm for the heterogeneous wireless networks, the route with the lowest cost and most resources is selected based on the integrated information of each resource estimation and the bottleneck information of each route found.
Besides considering the characteristic of the heterogeneous wireless networks, the module (type) of the route selection and distribution algorithms also induces different costs and performance. The existing algorithms can be defined and divided into two typical types: proactive (table-driven) protocol and reactive (source initiated) protocol. The proactive type protocol pays the memory and periodical update (bandwidth consumption) costs for selecting the routing directly. In opposite, the reactive type protocol saves the costs but may increase the overhead for finding a routing path to the destination. To decrease the total costs of finding and maintaining routing paths, the environment-aware based adaptive management for heterogeneous wireless networks is proposed in this thesis. Corresponding to the movement of the users, the appropriate type of the routing algorithm should be selected for reducing the total costs of finding routing paths. In the adaptive management, we propose the type selection process to individually evaluate the cost of the two type protocols (proactive and reactive) via considering the protocols and the mobility of the users. According to the evaluation results, the appropriate protocol with less cost will be selected for finding and maintaining the routes in the heterogeneous wireless networks.
According to the simulation, the routing selection and distribution algorithm proposed in this dissertation can not only effectively distribute the routing paths but also balance the load within homogeneous or heterogeneous wireless networks. Corresponding to the mobility of the users, the suitable type of routing protocol can be selected. Furthermore, the cost for routing paths searching, selection and maintenance is decreased. The block rate of these routing paths is reduced. Overall, according to the simulation, this dissertation makes the major contributions as follows:
1. The individual resource evaluations and managements for the mobile devices in the homogeneous wireless networks are proposed. The routes which satisfy the QoS can be selected and distributed according to the proposed algorithm.
2. The various wireless networks with different are integrated into a heterogeneous wireless network. The route search, selection, and maintenance algorithm for the hybrid properties heterogeneous wireless networks is proposed.
3. The classification to separate and classify the route search and selection algorithms is proposed. Corresponding to the mobility of the users, the environment-aware based adaptive management for heterogeneous wireless networks is proposed to reduce the costs caused by route search, selection, and maintenance.
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Vehicular Movement Patterns: A Sequential Patterns Data Mining Approach Towards Vehicular Route PredictionMerah, Amar Farouk 09 May 2012 (has links)
Behavioral patterns prediction in the context of Vehicular Ad hoc Networks (VANETs)has been receiving increasing attention due to enabling on-demand, intelligent traffic analysis and response to real-time traffic issues. One of these patterns, sequential patterns, are a type of behavioral patterns that describe the occurence of events in a timely-ordered fashion. In the context of VANETs, these events are defined as an ordered list of road segments traversed by vehicles during their trips from a starting point to their final intended destination, forming a vehicular path. Due to their predictable nature, undertaken vehicular paths can be exploited to extract the paths that are considered frequent. From the extracted frequent paths through data mining, the probability that a vehicular path will take a certain direction is obtained. However, in order to achieve this, samples of vehicular paths need to be initially collected over periods of time in order to be data-mined accordingly. In this thesis, a new set of formal definitions depicting vehicular paths as sequential patterns is described. Also, five novel communication schemes have been designed and implemented under a simulated environment to collect vehicular paths; such schemes are classified under two categories: Road Side Unit-Triggered (RSU-Triggered) and Vehicle-Triggered. After collection, extracted frequent paths are obtained through data mining, and the probability of these frequent paths is measured. In order to evaluate the e ciency and e ectiveness of the proposed schemes, extensive experimental analysis has been realized. From the results, two of the Vehicle-Triggered schemes, VTB-FP and VTRD-FP, have improved the vehicular path collection operation in terms of communication cost and latency over others. In terms of reliability, the Vehicle-Triggered schemes achieved a higher success rate than the RSU-Triggered scheme. Finally, frequent vehicular movement patterns have been effectively extracted from the collected vehicular paths according to a user-de ned threshold and the confidence of generated movement rules have been measured. From the analysis, it was clear that the user-de ned threshold needs to be set accordingly in order to not discard important vehicular movement patterns.
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Towards High Quality Video Streaming over Urban Vehicular Networks Using a Location-aware Multipath SchemeWang, Renfei 27 June 2012 (has links)
The transmitting of video content over Vehicular Ad Hoc Networks (VANETs) faces a great number of challenges caused by strict QoS (Quality of Service) requirements and highly dynamic network topology. In order to tackle these challenges, multipath forwarding schemes can be regarded as potential solutions. However, route coupling effect and the path length growth severely impair the performance of multipath schemes. In this thesis, the current research status about video streaming over VANETs as well as multipath transmissions are reviewed. With the demand to discover a more suitable solution, we propose the Location-Aware Multipath Video Streaming (LIAITHON+) protocol to address video streaming over urban VANETs. LIAITHON+ uses location information to discover relatively short paths with minimal route coupling effect. The performance results have shown it outperforms the underlying single path solution as well as the node-disjoint multipath solution. In addition, the impact of added redundancy on the multipath solution is investigated through LIAITHON+. According to the results, added redundancy has a different impact depending on the data rate.
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