Video dissemination capabilities are crucial for the deployment of many services over VANETs. These services range from enhancing safety via the dissemination of video from the scene of an accident, to advertisement of local services or businesses. This work considers the infrastructure-less scenario of VANETs and dissemination of video content over this network environment, which is extremely challenging mainly due to its dynamic topology and stringent requirements for video streaming. This study discusses issues and challenges that need to be tackled for disseminating high-quality video over VANETs. Furthermore it surveys and analyzes the suitability of different existing solutions aimed towards effective and efficient techniques for video dissemination in vehicular networks. As a result, a set of the most promising techniques are selected, described in detail and evaluated based on standard terms in quality of service. This thesis also discusses efficiency and suitability of these techniques for video dissemination and compares their performance over the same network condition. In addition, a detailed study on the effect of network coding on video dissemination protocols has been conducted to guide how to employ this technique properly for video streaming over VANETs. From this study, a summary of the observations was obtained and used to design a new hybrid solution by deploying robust and efficient techniques in number of existing protocols in an optimal manner. The proposed hybrid video dissemination protocol outperforms other protocols in term of delivery ratio and complies with other quality-of-service requirements for video broadcasting over vehicular environments.

Obtaining low-latency results from window-aggregate queries can be critical to certain data-stream processing applications. Due to a DSMS's lack of control over incoming data (typically, because of delays and bursts in data arrival), timely results for a window-aggregate query over a data stream cannot be obtained with guarantees about the results' accuracy. In this thesis, I propose a technique, which I term prodding, to obtain early result estimates for window-aggregate queries over data streams. The early estimates are obtained in addition to the regular query results. The proposed technique aims to maximize the contribution to a result-estimate computation from all the stateful operators across a multi-level query plan. I evaluate the benefits of prodding using real-world and generated data streams having different patterns in data arrival and data values. I conclude that, in various DSMS applications, prodding can generate low-latency estimates to window-aggregate query results. The main factors affecting the degree of inaccuracy in such estimates are: the aggregate function used in a query, the patterns in arrivals and values of stream data, and the aggressiveness of demanding the estimates. The utility of the estimates obtained using prodding should be optimized by tuning the aggressiveness in result-estimate demands to the specific latency and accuracy needs of a business, considering any available knowledge about patterns in the incoming data.

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Currently, there is a lack of research on the use of digital audio from the perspective of music educators in higher education. Researchers [for example: James Mason and Jared Wiercinski (2009), Jean E. Ferguson (2004), Richard Griscom (2003), Scott R. Phinney (2005) and Kathryn Sullivan, John J. Stafford, and Cindy Badilla-Melendez (2004)] have, however, studied streaming audio in relation to university students and libraries. Knowing the perceptions of instructors is important, because according to Oblinger & Oblinger (2005), they may not have the same perceptions as the students. Additionally, Moseley (2010) recommended further qualitative studies concerning the perceptions of faculty regarding technology utilization to allow more in-depth information to be discovered on the topic. The purpose of this qualitative multiple case study was to analyze music educators' perceptions and usage of the use of digital audio (e-reserves and streamed databases) in higher education. This research explained how and why these educators utilize (or do not utilize) streaming audio via e-reserves and databases. The research questions used for this study were: (a) How is streaming audio - in the form of e-reserves and subscription-based databases (Naxos and Classical Music Library - being utilized by college/university level educators at the two studied institutions?; (b) What are the perceptions of the participating music department faculty members on the subject of streaming audio?; and (c) What factors, regarding the use of streaming audio, are considered by the participating instructors to be important? Results of this research revealed participant instructors did utilize digital audio recordings, but not all of the instructors utilized streaming audio. The results of this study also revealed possible reasons for the lack of use of available streaming audio resources.

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Runt millennieskiftet upplevde den globala musikindustrin en dalande försäljning av fysiska format, som under nästan ett decennium hade svårt för att återhämta sig ekonomiskt. År 2008 etablerade sig den svenska musikstreamingtjänsten Spotify som av många sedan dess betraktats som musikindustrins och skivbolagens räddare. Fler streamingtjänster har sedan dess etablerat sig världen över och många ser idag på streaming som en vedertagen digital konsumtionsmodell. Denna studie undersöker streamingtjänsternas inverkar på musikindustrin. Studien ser efter vilka organisatoriska förändringar som har skett i och med streamingtjänsternas etablering, samt hur musikkonsumtionen och lyssningstrender har förändrats.Studiens empiri baseras på fyra intervjuer som har utförts med respondenter inom musikindustrin. Två av respondenterna arbetar för streamingtjänster och två arbetar för skivbolag. De tydligaste förändringarna som studien visar på är att streamingtjänsterna har intagit en multipel roll, vilket kan förkorta processen att tillgängliggöra musik för konsumenter. Förutom att vara en distributionsplattform som direkt levererar musik till konsumenter, har streamingtjänsterna blivit en attraktiv kanal för marknadsföring. De kan med sitt breda nätverk av användare, och tjänsternas integrering med sociala medier direkt nå musikkonsumenter över hela världen. När skivbolagen marknadsför genom streamingtjänsterna sker idag ingen ekonomisk transaktion, utan handlar mer om ett utbyte av tjänster.Streamingtjänsterna har också bidragit till att en ny aktör inom musikindustrin har inrättats, vilket är de digitala aggregatorerna. Dessa fungerar som en mellanhand mellan skivbolagen om streamingtjänsten. Studien visar också på en eventuell förändring hos konsumenterna, d.v.s. streaminganvändarna. En, enligt respondenterna, negativ utveckling i musiklyssnandet är det minskande behovet av album som format. En positiv utveckling är att befintlig forskning tyder på att internetpirater ser streaming som ersättning för illegal nedladdning. / Around the turn of the century the global music industry experienced a decline in sales of physical formats, which has sent the industry into nearly a decade of poor finance. In 2008, the Swedish music streaming service Spotify was established and has since then been regarded as the financial savior of the industry. Several streaming services has since then been established around the world and many are people today perceive streaming as a conventional digital consumption modelThis study examines streaming services and their impact on the music industry. The study investigates the organizational changes that have occurred in the streaming service establishment, and how music consumption and listening trends have changed. The empirical work of the study is based on four interviews that were conducted with respondents in the music industry. Two of the respondents work for streaming services and two working for record labels. The most obvious changes that the study indicates is that streaming services have adopted multiple roles, which can shorten the process of making available music to consumers.In addition to being a distribution platform that directly delivers music to consumers, streaming service has also become an attractive marketing channel. They can with the wide network of users, and integration with social media, directly reach music consumers worldwide. When record companies marketing through streaming services today, there is no economic transaction, but is more about an exchange of services.Streaming services have also contributed to a new entrant in the music industry has been established, which is the digital aggregators. These act as an intermediary between the record companies on the streaming service. The study also indicates a possible change among consumers, i.e. streaming users. One, according to respondents, negative trends in music listening is the diminishing need for the album format. A positive development is that existing research suggests that Internet pirates sees streaming as compensation for illegal downloads.

Since the discovery of stress-generated potentials (SGPs) in bone by Fukada and Yasuda in 1957, researchers have tried to understand their origin and function in the maintenance of bone. There have been a variety of methods attempting to quantify these SGPs in both wet and dry bone. In this study, I prepared both dry and wet beams of cortical bovine bone and subjected them to mechanical deformation in cantilever bending. Mechanical testing was performed to explore how the magnitude of the SGPs was affected by hydration levels, strain, and pressure gradients associated with various load magnitudes and deformation rates. Signals that were collected from the dry bone samples were attributed to motion artifact resulting from the movement of the materials testing machine and load cell. The SGPs from wet bone, on the other hand, consistently produced exponentially decaying signals following deformation that were maintained throughout held deformation and produced an SGP of opposite magnitude upon release of deformation. The exponentially decaying SGP signal produced after application of a step load to wet bone samples was determined to fit a two-term exponential equation (V(t) = Aet/τ1 + Cet/τ2). The first term, made up of the A-coefficient and τ1, was found to be dependent on deformation rate whereas the second term, containing the C-coefficient and τ2, was dependent on load magnitude. The sum of the two coefficients determine the maximum voltage the SGP can reach. Additionally, samples were left to air dry for one hour and tested intermittently throughout that time period. SGP signals diminished significantly over the hour, therefore, it has been concluded that the majority of the SGP signal is due to streaming potentials caused by ionic fluid movement within the bone upon deformation. / Thesis / Master of Applied Science (MASc) / Mechanical deformation of bone produces electrical signals known as stress-generated potentials (SGPs). In this study, I mechanically tested wet beams of bone to assess how the SGPs were affected by hydration levels, load magnitudes, and deformation rates. Dry bone samples did not produce any acceptable SGP signals. The SGPs from wet bone, however, produced repeatable signals that decayed following deformation. With a step load input, the decaying SGP signal fit a two-term exponential equation (V(t) = Aet/τ1 + Cet/τ2). The first term, made up of the A-coefficient and τ1, was found to be dependent on deformation rate whereas the second term, containing the C-coefficient and τ2, was dependent on load magnitude. The two coefficients, the A and C-coefficient, together determine the maximum voltage the SGP can reach. The result of this work showed that SGPs in bone are dependent on tissue hydration and vary with load magnitude and deformation rate.

An investigation into the parameters that define a good anchor block for a copolymer steric stabilizer was performed. The study focused on the effects of different functional groups on the adsorption properties of polymers. In addition, the effect of chain architecture as well as the impact of a hydrophobic end-group on polymer adsorption properties was determined. To complement the adsorption studies, a streaming potential instrument was built for use in measuring the adsorbed layer thickness of nonionic polymers on SiO₂. The research concluded with an examination of the effect of thermally induced insolubility on adsorption of a hydrogen-bonding polymer. Functional group effects were studied by measuring the adsorption isotherms of poly(2-ethyl-2-oxazoline), PEOX, poly(ethylene oxide), PEO, poly(vinyl alcohol), PVOH, and poly(ethylene imine), PEI, which was modified such that a 1,3-butanediol substituent replaced its imine hydrogens, on SiO₂, TiO₂, and Al₂O₃. PEOX and PEO, relatively basic polymers compared to PVOH were observed to adsorb only on the most acidic metal oxide, SiO₂. PVOH, however, was observed to adsorb on all three metal oxides, but to a lesser degree on SiO2 as compared to the more basic PEOX and PEO. These initial results were indicative of hydrogen-bonding mechanisms, a form of acid-base interaction. The most significant observation in the adsorption studies was that the linear hydroxyl modified PEI materials and their dendritic analogs adsorb on the metal oxides both above and below the i.e.p. This indicates that both electrostatic and hydogen-bonding mechanisms are driving the adsorption. The dendritic polymers, particularly a 4th generation dendrimer based on diaminopropane with a molecular weight of 16,640 g/mol adsorbed at a higher level when compared to the 41.3K g/mol PVOH and 30K g/mol PEOX. In addition to the dual adsorption mechanism, it was determined that the dendritic architecture appears to facilitate adsorption, as does the presence of the hydrophobic endgroup. The level of adsorption for all of the hydroxyl containing linear PEI and dendritic materials on the three metal oxides was high enough for them to be considered as anchor blocks in a copolymer steric stabilizer. The streaming potential instrument used to measure the adsorbed layer thickness on SiO₂. Adsorbed layer thickness of PEOX Mw = 10K and 30K g/mol were measured at approximately 1nm and 4.4 nm, respectively. In the case of the PEOX Mw = 30K g/mol homopolymer, the measured layer thickness was higher than that for a 23K g/mol PEO homopolymer. The degree of polymerization of the PEO is approximately 525, while for the PEOX it was only 300. This result was not expected. Finally, adsorption of PEOX was studied at the cloud point to determine whether insolubility could promote adsorption, while hydrogen-bonding, the room temperature driving force for adsorption, would decrease. Adsorption isotherm measurements were performed at 72 °C, and 75 °C, as the cloud point of the 30K PEOX was determined to be 73 °C. It was apparent that the adsorption decreased as temperature increased, indicating that without hydrogen bonding, thermally induced insolubility does not drive adsorption. / Ph. D.

The research work presented in this dissertation relates to lot streaming in two-stage flow shops and assembly shops. Lot streaming refers to the process of splitting a production lot into sublots, and then, processing the sublots on different machines simultaneously in an overlapping manner. Such a strategy allows finished material at each stage to be transferred downstream sooner than if production and transfer batches were restricted to be the same size. In the case when each sublot consists of just one item, a single-piece-flow is obtained. Such a continuous flow is a key element of the Toyota Production System. However, single-piece-flow increases the number of transfers and the total transportation cost (time). As a result, it may not be economically justifiable in many cases, and therefore, material may have to be transferred in batches (called transfer batches, or sublots). Lot streaming addresses the problems of determining optimal sublot sizes for use in various machine environments and optimizes different performance measures.Given this relationship between lot streaming and the Toyota Production System, lot streaming can be considered a generalization of lean principles. In this dissertation, we first provide a comprehensive review of the existing literature related to lot streaming. We show that two-stage flow shop problems have been studied more frequently than other machine environments. In particular, single-lot two-machine flow shops have been very well researched and efficient solution techniques have been discovered for a large variety of problems. While two-stage flow shop lot streaming problems have been studied extensively, we find that the existing literature assumes that production rates at each stage remain constant. Such an assumption is not valid when processing rates change, for example, due to learning. Learning here, refers to the improvements in processing rates achieved due to experience gained from processing units. We consider the case when the phenomenon of learning affects processing and setup times in a two-stage flow shop processing a single lot, and when, sublot-attached setup times exist. The decrease in unit-processing time, or sublot-attached setup time, is given by Wright's learning curve. We find closed-form expressions or simple search techniques to obtain optimal sublot sizes that minimize the makespan when the effect of learning reduces processing times, sublot-attached setup times, or, both. Then, we provide a general method to transform a large family of scheduling problems related to lot streaming in the presence of learning, to their equivalent counterparts that are not influenced by learning. This transformation is valid for all integrable learning functions (including the Wright's learning curve). As a result, a large variety of new problems involving learning can be solved using existing solution techniques. We then consider lot streaming in stochastic environments in the context of sourcing material. Such problems have been well studied in the literature related to lot streaming for cost-based objective functions when demand is continuous, and when processing times are deterministic, or, for material sourcing problems when the time required to procure a lot is stochastic but is independent of the lot size. We extend this study to the case when the time required to produce a given quantity of products is stochastic and dependent on the number of units produced. We consider the case when two sublots are used, and also compare the performance of lot streaming to the case when each sublot is sourced from an independent supplier. Next, we address a new problem related to lot streaming in a two-stage assembly shop, where we minimize a weighted sum of material handling costs and makespan. We consider the case when several suppliers provide material to a single manufacturer, who then assembles units from different suppliers into a single item. We assume deterministic, but not necessarily constant, lead times for each supplier, who may use lot streaming to provide material to the manufacturer. Lead times are defined as the length of the time interval between a supplier beginning to process material and the time when the first sublot is delivered to the manufacturer; Subsequent sublots must be transported early enough so that the manufacturer is not starved of material. The supplier may reduce this lead time by using lot streaming, but at an increased material handling cost. The decrease in lead time is also affected by other factors such as lot attached/detached setup times, transportation times etc. We allow these factors to be different for each supplier, and each lot processed by the same supplier. We refer to this problem as the Assembly Lot Streaming Problem (ALSP). We show that the ALSP can be solved using two steps. The first step consists of solution to several two-stage, single-lot, flow shop, makespan minimization problems. The solution to these problems generate prospective sublot sizes. Solution methods outlined in the existing literature can be used to complete this step. The second step obtains optimal number of sublots and production sequence. For a given production sequence, this step can be executed in polynomial-time; otherwise, the second step problem is NP-hard and integer programming formulations and decomposition-based methodologies are investigated for their solution. We make very limited assumptions regarding the handling cost and the relationship between the supplier lead time and number of sublots used. As a result, our solution methodology has a wide scope. / Ph. D.