When driving a vehicle on the road, the driver has to compensate continuously for small directional deviations from the desired course due to disturbances such as crosswinds, road irregularities and unintended driver inputs. These types of deviations have a tiring effect on the driver and should therefore be minimised. When the magnitude of these disturbances increases, especially with crosswind, the directional deviation might become so large that the driver will have difficulties in compensating for it, and will thereby affect the traffic safety. The objective of this research work is to increase the understanding of the crosswind sensitivity of buses and to find solutions to the problem of improving the safety of buses with respect to crosswind performance. The work presented in this thesis contributes to increased knowledge about the directional stability of buses under the influence of crosswind gusts through parameter studies using detailed vehicle simulation models, through full-scale experiments and through studies of the effect of steering feel on the subjective and objective evaluation of crosswind performance. A natural crosswind gust model has been derived from wind tunnel measurements and implemented in a multi-body dynamics simulation tool. The aerodynamic loads of the crosswind gust model have been applied on a detailed vehicle model and the behaviour of the vehicle model has been studied for various vehicle configurations in both open- and closed-loop manoeuvres. The vehicle model, with parameters corresponding to real vehicle data, has been validated and the agreement with measurements is good. A method for estimating the aerodynamic loads on a bus due to crosswind on a road section is also presented. Aerodynamic loads under real conditions were estimated using this method and these data were thereafter used in a study where the effect of steering feel on the subjective and objective evaluation of crosswind performance was investigated using a moving-base driving simulator, with the aim of finding a relationship between steering feel and crosswind sensitivity. The thesis covers the influence of changing chassis-related parameters and aerodynamics-related parameters on the crosswind sensitivity, as well as the influence of the setting of the steering system on the crosswind performance of the driver-vehicle system. The results identify areas of high potential for improving the crosswind sensitivity of buses, such as the centre of gravity location and the yaw moment overshoot at gust entry. Furthermore, the study shows the importance of having a vehicle that facilitates prompt driver corrections for reducing the lateral deviation under crosswind excitation; i.e. it is shown that a steering system with the possibility of changing the yaw rate gradient referencing the steering-wheel input when the vehicle is subjected to a sudden crosswind has a good potential for improving the crosswind performance of the driver-vehicle system. / QC 20100722

Syftet med denna uppsats är att identifiera olika utvecklingsmöjligheter som Apoteket AB har på den avreglerade apoteksmarknaden. Genom att analysera attraktiviteten i de olika möjligheterna är ambitionen att ge rekommendationer om framtida verksamhetsinriktningar där bolaget kan uppnå en positiv utveckling. För att identifiera utvecklingsmöjligheterna har djupgående intervjuer med personer inom Apoteket AB genomförts. Den empiriska informationen har analyserats med hjälp av en SWOT-analys samt en Directional Policy Matrix (DPM). Utifrån detta har en bedömning av marknadens attraktivitet samt företagets konkurrensförmåga genomförts för att bestämma respektive utvecklingsmöjlighets attraktivitet. I undersökningen identifierades fem potentiella utvecklingsmöjligheter. Resultatet visade att Apoteket AB har goda förutsättningar att satsa på internethandel, grossistverksamhet samt samarbete med en annan aktör. De rådande stand-still-direktiven hindrar Apoteket AB att vidta konkurrenskraftiga åtgärder tills de nya aktörerna etablerat sig. Grossistverksamhet och samarbete med andra aktörer kan därmed realiseras först när direktiven upphör. Med detta sagt är internethandel den enda av de attraktiva möjligheterna som bolaget i nuläget tillåts verkställa. För en differentiering mot särskilda sortiment och kundgrupper samt för vidare internationalisering har Apoteket AB i dagsläget inte tillräckligt med styrkor för att matcha dessa möjligheter. I framtiden kan dock mycket förändras och det gäller för Apoteket AB att omvandla sina svagheter till styrkor samt vara proaktiva så att fler utvecklingsmöjligheter kan realiseras.

Classical view of power system is characterized by a unidirectional power flow from centralized generation to consumers. Power system deregulation gave impetus to a modern view by introducing distributed generations (DGs) into distribution systems, leading to a bi-directional power flow. Several benefits of embedding DGs into distribution systems, such as increased reliability and reduced system losses, can be achieved. However, when a zone of the distribution system remains energized after being disconnected from the grid, DGs become islanded and early detection is needed to avoid several operational issues. In response to this call, a wavelet-based approach that uses the mean voltage index is proposed in this work to detect islanding operation in distribution systems embedding DGs. The proposed approach has been tested in several islanding and non-islanding scenarios using IEEE 13-bus distribution system. The results have shown the effectiveness of the proposed approach compared to other islanding approaches previously published in the literature. / UOIT

Neurologically normal individuals show a leftward spatial bias and tend to collide with objects on the right side more frequently than on the left. The upper visual field is associated with extrapersonal space, and mediated by the ventral stream through parvocellular projections. The lower visual field is associated with peripersonal space, and mediated by the dorsal stream through magnocellular projections. Upper and lower visual field differences have been observed in perceptual asymmetries but results have been mixed. Object- and space-based coordinates also both influence the leftward bias; however their relative contributions are unknown as similar spatial conditions are often collapsed across. More left-side collisions emerged on a route following task in the lower visual field and more right-side collisions were seen in the upper visual field (Thomas, Stuckel, Gutwin, & Elias, 2009). Left-handers made more right-side collisions in the central condition, whereas right-handers showed no bias. Leftward biases on the greyscales task were stronger in the lower visual field; however no distance-based differences were observed (Thomas & Elias, 2010). A stronger spatial bias was found on the greyscales task, whereas a stronger object-based bias was found on the object luminosity task (Thomas & Elias, in press). When individual spatial conditions were examined, the image chosen most often was always located in the lower field. Stimulus type and spatial location interacted to determine which coordinate type contributes more strongly to leftward biases. We also found that the leftward bias on the greyscales task was stronger in the lower visual field during prolonged presentation and in the upper visual field during brief presentation. A global motion task was created to preferentially engage magnocellular projections to the dorsal stream. Isoluminant red/green and blue/yellow colour tasks, which preferentially engage parvocellular projections to the ventral stream, were also created. Leftward biases were seen on the greyscales and motion tasks. On an isoluminant colour task, biases were significantly weakened, suggesting leftward biases exhibited by neurologically normal people are mediated by magnocellular projections to the dorsal stream and this preferential processing leads to a lower visual field advantage on the greyscales task.

El marco conceptual de la tesis esta definido por la utilización del Análisis Envolvente de Datos (DEA) para evaluar resultados de empresas y sectores industriales de países con economía de mercado avanzada y países en transición. DEA esta relacionado con los conceptos económicos de función de producción y frontera eficiente dentro de un marco non-parametrico. El análisis se centra en el tratamiento de temas como: los principales factores que determinan la tasa de variación del output; las economías de escala; eficiencia en beneficios; y el grado de utilización de la capacidad, para mencionar solo algunas de las aplicaciones que se van a encontrar en esta tesis. Desde un punto de vista metodológico, a medida que se avanza de un capitulo a otro, se pasa gradualmente de un marco de análisis menos restrictivo como por ejemplo las fronteras técnicas, a un marco mas restrictivo como las fronteras de costes y de beneficios. Se trabaja con los conceptos de función de distancia y de función de distancia direccional, así como con rendimiento de escala variables y constantes (VRS, CRS) y con orientación input y/o output. El primer Capitulo esta dedicado a la base de datos que consiste de 1379 empresas agrupadas en seis sectores de la industria manufacturera perteneciendo a: textil, papel y productos de papel, químicos, caucho y productos plásticos. Las empresas pertenecen a siete países europeos, cinco de la UE - Bélgica, Francia, Italia, Holanda y España - y dos países en transición, Bulgaria y Rumania. La base de datos contiene información contable de final de año y cubre un periodo de tiempo de cuatro años, de 1995 a 1998. En el Capitulo 2, el objetivo es cuantificar los principales factores explicativos de la tasa de variación del output y de aquí de la productividad global. La literatura tradicional sobre este tema da como principales factores explicativos el cambio en la eficiencia técnica, el cambio técnico y el consumo de inputs. La novedad sobre la metodología DEA utilizada en el Capitulo 2 consiste primero, en la medición del cambio técnico de tres maneras diferentes: (a) con datos del año final; (b) con datos del año inicial y (c) promediando los resultados de (a) y (b). Segundo, se calcula el efecto de escala partiendo de la variación en el consumo de inputs (en vez de la eficiencia técnica que se suele utilizar habitualmente). El Capitulo 3 trata el tema de la eficiencia en costes. El objetivo es presentar un método para estimar la ineficiencia debida a la existencia de inputs fijos en el proceso de producción. La dificultad de ajustarlos a corto plazo puede generar variaciones en el grado de utilización de la capacitad productiva. En el Capitulo 4, se construye una medida de la eficiencia en beneficios de una empresa, basada en el concepto de función de distancia direccional. Se define como la desviación normalizada entre los beneficios máximos y observados y se conoce con el nombre de Nerlovian Profit Efficiency (NPE). La normalización viene dada por el valor de la dirección de los variables input y output. En la maximización de los beneficios se considera también el impacto de restricciones adicionales sobre créditos, gastos financieros e inmovilizado y se relacionan con la literatura sobre restricciones presupuestarias.Globalmente, los resultados indican que las economías en transición van por detrás de las economías de mercado avanzadas, en todos los países las empresas presentan ineficiencia en costes debido a problemas de ajuste de los factores fijos de producción a corto plazo y las restricciones de presupuesto son limitativas especialmente para los países en transición. / The conceptual framework of this dissertation is defined by the use of Data Envelopment Analysis (DEA) tools for assessing corporate performance of firms and industrial sectors from countries acting long ago under the laws of the market mechanism, and from transition economies. DEA relates to the economic notion of a production function and an efficiency frontier in a non-parametric setting. The analysis performed here focuses on the treatment of issues related to: the performance of the firm analysing the main contributing factors in the output growth rate; an assessment of the effects of economies of scale; benchmarking of a firm's profit performance; and an assessment of the capacity utilisation degree, only to mention some of the applications to be found in this dissertation. From a methodological point of view, as we go over the chapters, we switch from a less restrictive framework of analysis, i.e. technical frontiers, to gradually more restrictive settings that is, cost and profit frontiers. We work in turn with distance functions and directional distance functions, VRS and CRS, and with both input, and/or output orientations.Chapter 1 is dedicated to the database which consists of 1379 firms grouped in six industrial sectors from the manufacturing industry: textile weaving; other textiles; pulp, paper and paperboard; basic chemicals; rubber products, and plastic products. We work with seven European countries, five of them belonging to the advanced market economies - Belgium, France, Italy, Netherlands, and Spain - and two from transition economies, Bulgaria and Romania respectively. The database consists of accounting information, end-year observations, and covers a time period of four years, from 1995 to 1998. In Chapter 2, the objective is to quantify the main contributing factors in explaining the growth in output, and hence firms' performance in productivity. The traditional literature on this topic gives as main explanatory factors for the observed changes in productivity: the technical efficiency change, technical change, and the increase in inputs' usage. The novelty about the non-parametric methodology (DEA) we use in Chapter 2 comes first, from the fact that it allows us to measure technical change, using three different settings: (a) work with final year data; (b) with initial year, and (c) averaging the results previously obtained in (a) and (b). Second, we capture the scale effect (usually isolated from the technical efficiency) from the decomposition of input usage factor. In Chapter 3, we take up the issue of assessing firms' performance from the perspective of cost efficiency analysis, maintaining the non-parametric framework. The objective of the chapter is to present a method for estimating the inefficiency due to the existence of fixed input factors in the production process. The difficulty to adjust them in the short-run could generate variations in the degree of utilisation of the productive capacity.In Chapter 4, our profit efficiency measure is constructed based on directional distance function concept rather than the usual distance function, commonly used in most applications. We define our profit efficiency measure as the normalised deviation between maximal and observed profits and we call it the Nerlovian Profit Efficiency (NPE). The normalisation is given by the value of the direction of input and output variables. We maximise profits also considering the impact of additional constraints on debts, interests paid and fixed assets, and link with the literature on soft/hard budget constraints.Overall, our findings show that the transition economies perform well behind the advanced market economies, in all countries firms exhibit cost inefficiency due to adjustment problems, and the budget constraints are binding especially for the transition countries.

Horizontal Directional Drilling (HDD) is used around the world when traditional open cut methods are not practical or impossible for installing pipelines. Maxi-sized drill rigs are the largest and most powerful directional drills and are more common in the field than ever before with over 5,000 rigs in operation world wide. The complexity of installations and the design associated with them continues to increase. This research has two main objectives. 1. Develop a real time data acquisition system for monitoring pullback forces on the product pipe; and, 2. Compare data gathered using maxi-sized drill rigs with current modelling methods using BoreAid. The first portion of the research, as listed above, required attaching multiple pressure transducers to the drilling display panel in an American Auger DD-1100 drill rig and recording, in real time, the carriage, rotation, and mud pressure as seen by the operator. This research also describes the various challenges and issues associated with developing real time in-the-bore data acquisition processes. Finally, future recommendations for further development of the in-the-bore data acquisition are discussed. The second portion of this research describes how the gathered data was processed into a workable data set. The field data was then compared to theoretical models by using the drill assistant tool BoreAid. The results of this comparison show that these models are appropriate for all size drill rigs, although some limitations are present.

Neurologically normal individuals show a leftward spatial bias and tend to collide with objects on the right side more frequently than on the left. The upper visual field is associated with extrapersonal space, and mediated by the ventral stream through parvocellular projections. The lower visual field is associated with peripersonal space, and mediated by the dorsal stream through magnocellular projections. Upper and lower visual field differences have been observed in perceptual asymmetries but results have been mixed. Object- and space-based coordinates also both influence the leftward bias; however their relative contributions are unknown as similar spatial conditions are often collapsed across. More left-side collisions emerged on a route following task in the lower visual field and more right-side collisions were seen in the upper visual field (Thomas, Stuckel, Gutwin, & Elias, 2009). Left-handers made more right-side collisions in the central condition, whereas right-handers showed no bias. Leftward biases on the greyscales task were stronger in the lower visual field; however no distance-based differences were observed (Thomas & Elias, 2010). A stronger spatial bias was found on the greyscales task, whereas a stronger object-based bias was found on the object luminosity task (Thomas & Elias, in press). When individual spatial conditions were examined, the image chosen most often was always located in the lower field. Stimulus type and spatial location interacted to determine which coordinate type contributes more strongly to leftward biases. We also found that the leftward bias on the greyscales task was stronger in the lower visual field during prolonged presentation and in the upper visual field during brief presentation. A global motion task was created to preferentially engage magnocellular projections to the dorsal stream. Isoluminant red/green and blue/yellow colour tasks, which preferentially engage parvocellular projections to the ventral stream, were also created. Leftward biases were seen on the greyscales and motion tasks. On an isoluminant colour task, biases were significantly weakened, suggesting leftward biases exhibited by neurologically normal people are mediated by magnocellular projections to the dorsal stream and this preferential processing leads to a lower visual field advantage on the greyscales task.

A new two-dimensional transform is derived and implemented that is able to discriminate with respect to angular and radial frequency. This octave-band directional filter bank (OBDFB) is maximally decimated, has a separable polyphase implmentation, provides perfect reconstruction, and can be implemented in a tree structure allowing for a somewhat arbitrary number of angular and radial divisions. This decomposition is based on the directional filter bank (DFB) and is compared to other transforms with similar properties. Additionally, the OBDFB is used in three applications. Texture segmentation results are provided with comparisons to both decimated and undecimated transforms. With hyperspectral data, the OBDFB is used to increase classification accuracy using texture augmentation and likelihood score combination. Finally, ultrasound despeckling is addressed with respect to real-time implementations, and subjective test results are presented. A non-uniform two-dimensional transform is also designed that is a modified version of the OBDFB. It is rationally sampled and maximally decimated, but it provides both angular and radial frequency passbands from the initial stage instead of making separate divisions like the OBDFB. It also does not create subband boundaries on the principal frequency axes and allows for further decomposition as well.

The use of high power converters has increased tremendously. Increased demand for transportation, housing and industrial needs means that more number of power converters interact with the utility power grid. These converters are non-linear and they draw harmonic currents, significantly affecting power quality. To reduce harmonics, filters, power factor correction circuits and capacitor banks are required. And the development of hybrid technologies and renewable energy power stations trigger a demand for power converters with bi-directional capabilities. The objective of this thesis is to develop a high power quality, bi-directional AC-DC power converter that is a solution to the aforementioned problems. This thesis studies an existing topology for a high power AC-DC power conversion with transformer isolation. The topology consists of an uncontrolled rectifier followed by a DC-DC converter to produce a set voltage output. A design example of the topology is simulated using the PSIM software package (version 6). Critical performance characteristics such as power factor and total harmonic distortion are analyzed. Following that study a new topology is proposed, which is an improvement over the older design, with reduced power conversion stages. The new topology has a fully controlled current source Pulse Width Modulation (PWM) rectifier at the front end to replace the uncontrolled rectifier and DC-DC combination. This topology has multiquadrant operational capabilities and the controller employs Selective Harmonic Elimination techniques to produce the programmed PWM switching functions for the rectifier. A design example of the converter and the digital controller are simulated in PSIM environment. The converter input current THD (Total Harmonic Distortion) and input power factor are within IEEE 519 and DoE standards. The converter is simulated in both first and fourth quadrant operations. A side-by-side comparison of the two topologies is done with respect to design and performance features such as power factor, THD, filter size, etc. The new topology converter provides performance superior to that of the older topology. Finally the thesis explores possible applications for the converter in power supplies, renewable energy and hybrid technologies.

Ad hoc wireless networks are constructed by several mobile hosts and have a property that its topology is changed as mobile hosts moved. There is no stationary infrastructure or based station to coordinate packets transmissions and advertise the information of network topology or something important. The special networks are used in temporal wireless networks, such as battlefield, disease rescue place, and so on. So without any stationary infrastructure supported, mobile hosts can communicate with others immediately or indirectly. Because topology is often changed while mobile hosts moving, mobile hosts must exchange information to deal with the changed conditions. Mobile hosts often utilize broadcasting to exchange information with their neighbor hosts, but there is high bit error ratio in wireless networks, packet corruption occurs frequently, so that mobile host might lost some important information sent from its neighboring host. In 802.11 standard, lack of acknowledgement, broadcasting is an unreliable transmission, because sender host do not know whether all of it neighboring hosts received broadcasting packets correctly or no. Many proposed papers of reliable broadcast assumed that links between mobile hosts are bidirectional links, but bidirectional link is an ideal assumption. In real environment, links are unidirectional, so host A could send packets to host B immediately, but host B could not because of their transmission range are different. In this paper, we propose a new reliable broadcast scheme, Highly Reliable Broadcast Scheme with Directional Antennas (HRBSDA). HRBSDA can reduce the influence of unidirectional links and reach for highly reliable broadcasting. HRBSDA uses directional antennas and concept of Time Division Multiple Access (TDMA)-like. HRBSDA divide DCF Inter-Frame Space (DIFS) into several minislots, and mobile hosts use these minislots to ask sender for retransmission of lost packets. By the way, HRBSDA can not only reach for highly reliable broadcasting, but also reduce Packet Loss Recovery Time, and avoid causing extra overhead. Using directional antennas HRBSDA can reduce collision, so that improving throughput and channel utilization.