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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
221

Development of a Deflection Measurement System for the Hybrid III Six-Year Old Biofidelic Abdomen

Gregory, Thomas S. 30 January 2013 (has links)
Despite advancements in automotive safety, motor vehicle collisions remain the leading cause of unintentional death for children ages 5 to 14. Enhancement of child occupant protection depends on the ability to accurately assess the effectiveness of restraint systems. Booster seat design and proper belt fit require evaluation using child anthropomorphic test devices, yet biofidelity of the abdomen and pelvis of the current anthropomorphic test device, the Hybrid III 6-year-old, needs improvement. Further, measurement of abdominal deflection is needed for quantification of the degree of submarining and associated potential injury risk. A biofidelic abdomen for the Hybrid III 6-year-old dummy is being developed by the Ford Motor Company. A practical measurement system for the biofidelic abdominal insert has been developed and demonstrated for three dimensional determination of abdominal deflection. Quantification of insert deflection is achieved via differential signal measurement using electrodes mounted within a conductive medium. Signal amplitude is proportional to the distance between the electrodes. A microcontroller is used to calculate distances between ventral electrodes and a dorsal electrode in three dimensions. This system has been calibrated statically, as well as evaluated dynamically. Its performance has also been demonstrated in a series of sled tests. Deflection measurements from the instrumented abdominal insert showed clear differences between two booster seat designs, yielding an average peak anterior to posterior displacement of the abdomen of 1.0 ± 3.4 mm and 31.2 ± 7.2 mm for the seats, respectively. Implementation of a 6-year-old abdominal insert with the ability to evaluate submarining potential will likely advance the effectiveness of booster seat design and restraint performance, and help mitigate child occupant injury severity in automobile collisions. / Master of Science
222

An Exploration of Hybrid Hard Disk Designs Using an Extensible Simulator

Konanki, Pavan 29 December 2008 (has links)
The growing performance gap between CPUs and sustainable disk I/O is a major hurdle in supporting modern applications. As the CPUs become faster, this gap is projected to worsen, thus making it a critical problem that should be addressed with high priority. Although efficient algorithms have alleviated this problem, the mechanical nature of the disk places physical limits on the achievable speedup. On the other hand, newer technologies such as flash memory promise significant improvements in access time, power consumption, and storage density. However, the mature disk technology offers the most favorable cost per bit ratio. Since replacing standard hard disks with flash disks is prohibitively expensive, hybrid hard disks augment the standard hard disk with a small amount of flash memory. By exploiting the beneficial aspects of both technologies they aim to provide breakthrough increase in performance. Nevertheless, hybrid hard disks pose several significant design challenges. Effective and efficient algorithms to manage the flash, the disk, and interaction between them are required. To facilitate rapid and easy exploration of the design space for hybrid hard disk algorithms we present the design and implementation of a flexible and extensible simulator that models hybrid hard disks. The simulator is flexible in that it models several configurations in which the flash and the magnetic medium interact. The simulator is extensible in that it provides a simple framework to plug in several algorithms to manage the hybrid hard disk. We validate our simulator and analyze the performance of the hybrid hard disk for real workloads. / Master of Science
223

A Neurophysiological Approach to Differentiate Core Disgust and Moral Disgust

Golden, Lauren Leigh 06 June 2013 (has links)
The association between core disgust and moral disgust has been a particularly contentious issue within the emotion literature. Preliminary neurophysiological evidence appeared to support a hybrid theory of the relation between core disgust and moral disgust, suggesting reactivity to bodily moral disgust stimuli is similar to core disgust reaction patterns and reactivity to non-bodily moral disgust stimuli is similar to that of anger.  The aim of this project was to test this theory.  In Study 1, participants viewed and rated emotion video clips to ensure the video clips shown in Study 2 elicited the intended emotions. In Study 2, the selected video clips were shown while EEG and ECG data were collected.  It was hypothesized that there would be similar cerebral asymmetry, heart rate, and heart rate variability patterns between contamination-related core disgust and bodily moral disgust and between anger and non-bodily moral disgust. Although the results of this study did not fully support these hypotheses, preliminary evidence was found to support the hybrid theory of disgust. Based on the participant ratings and observed frontal asymmetry scores, similarities were found amongst contamination-related core disgust and bodily moral disgust and with non-bodily moral disgust and anger. These results warrant further investigation into the disgust construct in order to continue to explore the validity of the hybrid theory of disgust. / Ph. D.
224

Spiragården / Spiragården

Befrits Terpstra, Saskia January 2022 (has links)
Spiragården, an education center in Torshälla.A place that promotes the exchange of knowledge in the field of cultivation, agriculture and self-sufficiency. The premises provides space for education and food production. There are also dynamic meeting areas and a cafeteria with an associated farm shop where occasional visitors meet the daily users of the place. In addition to a purely practical function, courtyards with irrigation ponds also contribute to a bright and calm inner world. The dynamic hall with associated meeting rooms and cafeteria can be used by other businesses in the same area, such as a club or a farming association. Here you can hold lectures, meetings, courses, organize fairs or other events. The building alternates between climate zones. Some parts have a completely controlled climate, others are allowed to vary in temperature. This is made possible by a wooden construction that is built on with either an insulated metal roof or an uninsulated polycarbonate roof, depending on climate zone. The façade consists of elements in wood and glass, the greenhouse's exterior consists entirely of wood and polycarbonate. / Spiragården, ett utbildningscenter i Torshälla. En plats som främjar kunskapsutbyte inom området odling, jordbruk och självhushåll. Lokalerna ska tillhandahålla utrymme för utbildning och matproduktion. Här finns även dynamiska samlingsytor och en cafeteria med tillhörande gårdsbutik där tillfälliga besökare möts med platsens dagliga användare. Här ska finnas utbildning inom trädgård på olika nivåer, heltid, deltid, öppna föreläsningar och kortkurser. Trädgårdsmästare jobbar tillsammans med eleverna och det som produceras används i cafeterian, säljs i gårdsbutiken och vidare till närliggande aktörer. Innergårdar med bevattningsdammar bidrar förutom som rent praktiska funktion också med en ljus och lugn inre värld. Den dynamiska hallen med tillhörande samlingslokaler och cafeteria kan användas av andra verksamheter inom samma område, exempelvis en klubb eller en odlingsförening. Här kan man hålla föredrag, träffar, kurser, anordna mässor eller andra evenemang. Byggnaden växlar mellan klimatzoner. Vissa delar har helt kontrollerat klimat, andra tillåts variera i temperatur. Det möjliggörs av en träkonstruktion som byggs på med antingen isolerat plåttak eller oisolerat tak i polykarbonat. Fasaden består av element i trä och glas, växthusets yttre består helt av trä och polykarbonat.
225

Morphometric Characterization of a <i>Mercenaria</i> spp. (Bivalvia) Hybrid Zone: Paleontological and Evolutionary Implications

Powell, Matthew G. 23 May 2000 (has links)
Paleontological documentation of hybridization events has the potential to address a multitude of evolutionary and paleobiological issues unanswerable by purely biological means. However, previous studies of modern hybrids suggest that their morphology is often insufficient for their reliable discrimination. This study analyzes the morphology of an extant, genetically-identified <i>Mercenaria</i> spp. (Bivalvia: Veneridae) hybrid zone using Bookstein coordinates and multivariate methods to answer two questions: (1) can hybrid <i>Mercenaria</i> spp. individuals be identified based on morphology alone, and (2) would a <i>Mercenaria</i> spp. hybrid zone be recognizable in the fossil record? Multivariate statistical procedures (principal components analysis, canonical variate analysis, etc.) using Bookstein coordinates demonstrate that, within the hybrid zone, hybrid individuals cannot be identified due to extreme overlap with the parental taxa. The hybrid zone as a whole, however, can be identified by comparison with pure-species populations sampled from outside the hybrid zone. Hybrid zones occupy parental species morphospace plus intermediate morphospace. The technique of using multiple pure-species populations to establish species morphospace is introduced to control for processes that may also result in morphological intermediates at ecological time scales (dimorphism, ecophenotypy, and geographic variation). Four alternative causal explanations of morphological intermediates through geological time (primary intergradation, uncoupled genetic and morphological divergence, time-averaged evolving populations, and developmentally instable populations) are evaluated. A literature survey strongly suggests that neither time-averaging nor developmental instability is occurring at the beginning of a lineage's evolutionary history, and that hybridization may be much more extensive than paleontological data suggest. / Master of Science
226

Hybrid entrepreneurship in just transitions: Dealing with dilemmas facing ‘the other’

Colbourne, R., Ejaz, L., Grinevich, Vadim, Husain, S., O'Farrell, D. 13 October 2024 (has links)
Yes / The aim of the paper is to investigate the role of hybrid entrepreneurship in developing justice and diversity responses to sustainability transitions that are complicated by contexts of ambiguous socio-technological shifts and manifested in material and ethical dilemmas for ‘the other’, i.e., those deemed different. Based on analysis of two original case studies featuring the other—the Nisichawayasihk Cree Nation indigenous community in Canada and the Karachi Down Syndrome Program in Pakistan—we identify the conditions for engaging minority communities in strong collaborative and participatory cross-stakeholder processes to deal with dilemmas posed by sustainability transitions. We centre on issues of social inclusion and social equity. We illuminate how hybrid entrepreneurship practices enable, structure and manage collective learning within and outside hybrid ventures to facilitate equitable transitions. Finally, we propose how to co-create actions that amplify marginalized voices to influence institutions.
227

Mild Hybrid System in Combination with Waste Heat Recovery for Commercial Vehicles

Namakian, Mohsen January 2013 (has links)
Performance of two different waste heat recovery systems (one based on Rankine cycle and the other one using thermoelectricity) combined with non-hybrid, mild-hybrid and full hybrid systems are investigated. The vehicle under investigation was a 440hp Scania truck, loaded by 40 tons. Input data included logged data from a long haulage drive test in Sweden.All systems (waste heat recovery as well as hybrid) are implemented and simulated in Matlab/Simulink. Almost all systems are modeled using measured data or performance curves provided by one manufacturer. For Rankine system results from another investigation were used.Regardless of practical issues in implementing systems, reduction in fuel consumption for six different combination of waste heat recovery systems and hybrid systems with different degrees of hybridization are calculated. In general Rankine cycle shows a better performance. However, due to improvements achieved in laboratories, thermoelectricity could also be an option in future.This study focuses on “system” point of view and therefore high precision calculations is not included. However it can be useful in making decisions for further investigations.
228

Control of a Ground Source Heat Pump using Hybrid Model Predictive Control / Reglering av en bergvärmepump med hjälp av hybrid modellprediktiv reglering

Sundbrandt, Markus January 2011 (has links)
The thesis has been conducted at Bosch Thermoteknik AB and its aim is to develop a Model Predictive Control (MPC) controller for a ground source heat pump which minimizes the power consumption while being able to keep the inside air temperature and Domestic Hot Water (DHW) temperature within certain comfortintervals. First a model of the system is derived, since the system consists of both continuous and binary states a hybrid model is used. The MPC controller utilizes the model to predict the future states of the system, and by formulating an optimizationproblem an optimal control is achieved. The MPC controller is evaluated and compared to a conventional controller using simulations. After some tuning the MPC controller is capable of maintaining the inside air and DHW temperature at their reference levels without oscillating too much. The MPC controller’s general performance is quite similar to the conventional controller, but with a power consumption which is 1-3 % lower. A simulation using an inside air temperature reference which is lowered during the night is also conducted, it achieved a power consumption which was 7.5 % lower compared to a conventional controller.
229

Simulation of a parallel hydraulic hybrid refuse truck

Anderson, Garrett Lance 20 February 2012 (has links)
A rear loading refuse truck was simulated with a conventional and hydraulic hybrid configuration. Models for the hydraulic hybrid components were developed to simulate the system. A control algorithm was developed using a stochastic dynamic programming approach. The results did not match those that are advertised by the commercially available systems, but reasons for this deviation are discussed. The predicted improvement in fuel economy ranged from 1% to 15% depending on variance in drive cycle and vehicle weight. A brief analysis of the cost of the hybrid system was also conducted based on an estimated drive cycle. This analysis showed that, at current fuel prices of about $4.00/gallon, the system may not make financial sense for a 10 year period of ownership. / text
230

Parametric study on hybrid rocket propulsion system performance measured by the system specific impulse

Bussmann, Adam January 2022 (has links)
Hybrid rocket motors have become of great international interest during the last couple of years. A hybrid rocket motor is propelled by the use of a solid fuel and a liquid oxidizer. The fundamental principle of the hybrid propelled system is that the liquid oxidizer is injected into a combustion chamber to enable the combustion of the solid fuel. The exhaust gases are then accelerated through a nozzle to supersonic velocity to produce the desired level of thrust. To describe the overall performance of a propulsion system, it is common use the specifc impulse which expresses the performance as the total impulse per mass unit of propellant. However, in order to optimize a propulsion system, it is necessary to consider the entire system with the oxidizer tank, feed system, combustion chamber and nozzle. The issue with using the specifc impulse as a performance index is that it does not consider the total mass of the propulsion system. Therefore, this thesis will instead analyze the system specifc impulse, which expresses the performance as the total impulse per mass unit of propulsion system. By studying the entire hybrid propulsion system it is possible to determine the relations between the various parameters of the diferent components and should therefore be able to optimize the mass, volume and system specifc impulse of the system. This master’s thesis aims to illustrate how the hybrid propulsion system can be optimized depending on various fxed parameters. This analysis studies a generic hybrid propulsion systemwith Hydroxyl-terminated polybutadiene (HTPB) as a solid fuel with diferent combinations ofoxidizers. Each oxidizer- and fuel confguration shall have identical combustion chamber presssures and shall generate the same total impulse. Nevertheless, each combination will result indiferent specifc impulses since the optimal confguration for each combination will generate diffferent oxidizer and fuel masses. It is then desirable to analyze how the diferent components ofthe propulsion system are affected by the required oxidizer and fuel for each optimal confgurationand how it drives the design of the system and generates diferent system specifc impulses.

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