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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.
1

Development of a Pre-Impact Environmental Site Characterization for the Bryan Mound, Texas Strategic Petroleum Reserve

Hernandez, Sylvia A. 12 1900 (has links)
This thesis presents a model for developing site-specific contingency plans to be used during spill response, remediation, and post-spill monitoring using the Strategic Petroleum Reserve's Bryan Mound site as a case study. Bird and vegetation observations provide baseline data for biological conditions, and sediment sampling for total petroleum hydrocarbons serves as a chemical component of the model. Results demonstrate previously unknown conditions that would hinder remediation and affect the persistence of petroleum contaminants. Results also established previously unmapped dominant bird and vegetation types likely to be impacted by a spill at the site. This model points to a reconsideration of individual facilities' responsibilities when planning for large-scale disasters and protecting the sensitive ecosystems surrounding their sites.
2

Individualized Motion Monitoring by Wearable Sensor : Pre-impact fall detection using SVM and sensor fusion / Individanpassad rörelsemonitorering med hjälp av bärbara sensorer

Carlsson, Tor January 2015 (has links)
Among the elderly, falling represents a major threat to the individual health, and is considered as a major source of morbidity and mortality. In Sweden alone, three elderly are lost each day in accidents related to falling. The elderly who survive the fall are likely to be suffering from decreased quality of life. As the percentage of elderly increase in the population worldwide, the need for preventive methods and tools will grow drastically in order to deal with the increasing health-care costs. This report is the result of a conceptual study where an algorithm for individualized motion monitoring and pre-impact fall detection is developed. The algorithm learns the normal state of the wearer in order to detect anomalous events such as a fall. Furthermore, this report presents the requirements and issues related to the implementation of such a system. The result of the study is presented as a comparison between the individualized system and a more generalized fall detection system. The conclusion is that the presented type of algorithm is capable of learning the user behaviour and is able to detect a fall before the user impacts the ground, with a mean lead time of 301ms. / Bland äldre är risken för att drabbas av fallrelaterade skador överhängande, ofta med svåra fysiska skador och psykiska effekter som följd. Med en ökande andel äldre i befolkningsmängden beräknas även samhällets kostnad för vård att stiga. Genom aktiva samt preventiva åtgärder kan graden av personligt lidande och fallre- laterade samhällskostnader reduceras. Denna rapport är resultatet av en konceptuell studie där en algoritm för aktiv, individanpassad falldetektion utvecklats. Algoritmen lär sig användarens normala rörelsemönster och skall därefter särskilja dessa från onormala rörelsemönster. Rapporten beskriver de krav och frågeställningar som är relevanta för utvecklingen av ett sådant system. Vidare presenteras resultatet av studien i form av en jämförelse mellan ett individanpassat och generellt system. Resultatet av studien visar att algoritmen kan lära sig användarens vanliga rörelsemönster och därefer särskilja dessa från ett fall, i medelvärde 301ms innan användaren träffar marken.
3

Occupant Responses of Relaxed and Braced 5th Percentile Female and 50th Percentile Male Volunteers during Low-Speed Frontal and Frontal-Oblique Sled Tests

Chan, Hana 05 July 2023 (has links)
The increased prevalence of crash avoidance technologies like autonomous emergency braking necessitates understanding of occupant responses during low-speed frontal pre-crash braking and low-severity crash events. Active human body models (HBMs) have emerged as valuable tools to evaluate occupant safety during these events, but must be validated with relevant volunteer data to accurately represent the responses of live occupants. The objective of this dissertation was to quantify the occupant responses of relaxed and braced 5th percentile female and 50th percentile male volunteers during low-speed frontal and frontal-oblique sled tests designed to simulate pre-crash braking and low-severity crash events. A study comprised of 160 low-speed sled tests was performed with 20 volunteers. The volunteers' kinematics, kinetics, and muscle responses were compared to determine how altering impact direction (frontal and frontal-oblique), impact severity (1 g and 2.5 g), demographic group (mid-size male and small female), and muscle state (relaxed and braced) affected occupant responses. The volunteers' occupant responses were significantly affected by impact direction, impact severity, demographic group, and muscle state. The frontal-oblique tests resulted in greater leftward excursions compared to the frontal tests. Increasing the pulse severity resulted in greater forward excursions, reaction forces, and muscle activation. The male volunteers exhibited greater forward excursions and reaction forces compared to the female volunteers. However, the two demographic groups exhibited similar muscle activation during the sled tests. Bracing increased the volunteers' initial joint angles, muscle activation, and reaction forces prior to the sled tests. Bracing decreased forward excursions and increased reaction forces during the sled tests. The relaxed volunteers exhibited greater relative changes in occupant responses compared to the braced volunteers. Overall, this study demonstrated that muscle activation significantly affected the volunteers' kinematics, kinetics, and muscle responses for both mid-size males and small females during low-speed events. Observed differences between demographic groups were more prominent when relaxed and more diminished when braced. These results underscore the importance of validating active HBMs with relevant volunteer data in order to be more representative of live occupants for a wider range of demographic groups in varying muscle states. Finally, this dissertation provides a large, comprehensive, and novel biomechanical dataset that can be used to develop and validate active HBMs for use in assessing occupant response during frontal pre-crash braking and low-severity crash events. These models will help improve the understanding of potential injury risk and development of effective vehicle safety systems for use during low-speed events. / Doctor of Philosophy / Computer models, known as active human body models (HBMs), have emerged as tools that can be used to assess occupant safety during low-speed vehicle crashes. In these types of events, occupants have enough time to react and potentially brace before the crash, which could in turn affect their responses during the crash. It is important to understand how occupants respond during crashes so that effective vehicle safety systems can be developed. Active HBMs are particularly valuable because they can simulate muscle activation to reflect the response of live occupants. However, data are needed from live occupants to ensure that these models are accurate. To gather this data, a study was performed where volunteers experienced low-speed frontal sled tests when they were relaxed and braced. The sled tests were designed to simulate pre-crash braking and low-severity vehicle crashes. Mid-size male and small female volunteers were recruited to participate to represent the standard adult occupant populations used in current frontal impact vehicle safety standards. A motion capture system was used to measure the volunteers' forward motion, load cells were used to measure the volunteers' exerted reaction forces on the test buck, and electrodes were used to measure the volunteers' muscle activity. The volunteers' responses were significantly different between the relaxed and braced muscle states, and between the males and females. Comparing between males and females, the males moved farther forward and exerted larger reaction forces, but both demographic groups exhibited similar muscle responses. Comparing between muscle states, bracing increased the volunteers' muscle activation and reaction forces before the sled tests. Bracing also increased the volunteers' reaction forces during the sled tests, but decreased forward movement. Overall, the volunteers exhibited greater relative changes in response when they were relaxed compared to when they were braced. Overall, this study demonstrated that muscle activation significantly affected the volunteers' responses for both mid-size males and small females during low-speed events. These results highlight the importance of developing active HBMs with relevant volunteer data in order to be more representative of live occupants. Finally, the data from this study can be used to develop active HBMs to improve their accuracy, so that the models can be used to assess occupant safety during low-speed frontal vehicle crashes. This will help improve the understanding of potential injury risk and development of effective vehicle safety systems, to reduce the number of injuries caused by vehicle crashes.
4

Elevers erfarenheter av olika undervisningsstilar : En kvalitativ fallstudie om elevers erfarenheter av undervisningsstilar i idrott och hälsa

Sandström, Christoffer January 2022 (has links)
Syftet med denna uppsats är att undersöka hur sex elever uppfattar sin undervisande lärares undervisningsstilar i idrott och hälsa. Studien fokuserar även på hur delaktiga eleverna får vara vid planering, genomförande och utvärdering av en lektion. I litteraturgenomgången har jag använt mig utav litteratur, forskning och Skolverket för att få en djupare bild av hur elevers erfarenheter ser ut av just undervisningsstilar. Jag har tagit utgångspunkt i Musska Mosstons elva olika undervisningsstilar. I denna kvalitativa fallstudie har semi-strukturerade intervjuer använts som metod för att forska kring undervisningsstilar. Sex intervjuer har genomförts med elever som går i årskurs nio. Det resultat som framkom genom studien var att reproduktiva undervisningsstilar är mest förekommande i planeringsstadiet. I genomförandefasen av en lektion är det mer produktiva stilar som blir framträdande samt att i utvärderingsfasen av en lektion så är det mer reproduktiva stilar som används för dessa elever. / The aim of this study is to investigate students perceptions about teaching styles in physical education. The study’s focus is also how involved students are within the pre-impact phase, the impact phase and the post-impact phase. When I have been searching for information, I have been using literature, research and Skolverket to get a deeper picture of how students perceptions are about teaching styles, you can read about this in the literature review. In this study, as starting point I have taken Musska Mosston’s eleven different teaching styles.  In this study, I have used qualitative semi-structured interviews with six students about teaching styles. The interviewed students are going in the ninth grade.  The result of this study is that when pre-impact, the reproductive teaching styles is more prominent. When impact, productive teaching styles is more dominant. When post-impact of a lesson, reproductive teaching styles is more dominant for these students.

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