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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.
211

Aerodynamic Load Characteristics Evaluation and Tri-Axial Performance Testing on Fiber Reinforced Polymer Connections and Metal Fasteners to Promote Hurricane Damage Mitigation

Canino-Vazquez, Iván R. 13 November 2009 (has links)
Damages during extreme wind events highlight the weaknesses of mechanical fasteners at the roof-to-wall connections in residential timber frame buildings. The allowable capacity of the metal fasteners is based on results of unidirectional component testing that do not simulate realistic tri-axial aerodynamic loading effects. The first objective of this research was to simulate hurricane effects and study hurricane-structure interaction at full-scale, facilitating better understanding of the combined impacts of wind, rain, and debris on inter-component connections at spatial and temporal scales. The second objective was to evaluate the performance of a non-intrusive roof-to-wall connection system using fiber reinforced polymer (FRP) materials and compare its load capacity to the capacity of an existing metal fastener under simulated aerodynamic loads. The Wall of Wind (WoW) testing performed using FRP connections on a one-story gable-roof timber structure instrumented with a variety of sensors, was used to create a database on aerodynamic and aero-hydrodynamic loading on roof-to-wall connections tested under several parameters: angles of attack, wind-turbulence content, internal pressure conditions, with and without effects of rain. Based on the aerodynamic loading results obtained from WoW tests, sets of three force components (tri-axial mean loads) were combined into a series of resultant mean forces, which were used to test the FRP and metal connections in the structures laboratory up to failure. A new component testing system and test protocol were developed for testing fasteners under simulated tri-axial loading as opposed to uni-axial loading. The tri-axial and uni-axial test results were compared for hurricane clips. Also, comparison was made between tri-axial load capacity of FRP and metal connections. The research findings demonstrate that the FRP connection is a viable option for use in timber roof-to-wall connection system. Findings also confirm that current testing methods of mechanical fasteners tend to overestimate the actual load capacities of a connector. Additionally, the research also contributes to the development a new testing protocol for fasteners using tri-axial simultaneous loads based on the aerodynamic database obtained from the WoW testing.
212

Factors Affecting Storm Characteristics in the Battery and Vicinity

Kay, Shannon A 01 January 2014 (has links)
Tropical cyclones (TCs) Irene and Sandy caused major damages in back to back years to the most densely populated city in the United States stunning the residents with storms linked to seemingly impossible probabilities. Such activity has raised questions about the effect of non-stationary aspects within atmospheric circulation on storm behavior and some assumptions inherent in previous hazard studies of the New York City (NYC) area. This study analyzes statistical aspects of hazard quantification for this area related to this non-stationarity and statistical characterization. In particular this study investigates the presence of multiple populations of storms, it also tests current assumptions inherent in these previous studies which produce surge hazards which differ significantly and it investigates a natural relationship between storm characteristics and large scale climate variations through Empirical Orthogonal Functions (EOF) of the sea surface pressure. The findings of this study show that there is a statistically significant influence of climate variability on storm frequency, intensity and direction within the Battery and vicinity (BAV, Battery Park and surrounding region). Variations in large-scale atmospheric pressure patterns as well as sea surface temperature appear to be significantly affecting the surge hazard for this region. This study also shows there is a statistically significant relationship between storm heading and intensity as well as the presence of multiple populations of storms driven by different atmospheric states that behave with alternate characteristics. These multiple populations appear to be significantly influencing the overall average of storm behavior causing inaccurate assumptions in hazard quantification which leads to misestimation in risks.
213

Implementace tvarování anténních příjmových svazků radaru v FPGA / Radar receiver beamforming implementation in FPGA

Bárta, Jakub January 2019 (has links)
This thesis deals with design and implementation of digital beamformer for 3D radar. The text of this thesis contains derivation of beamforming algorithm and detailed description of it’s implementation on development kit with Cyclone V circuit. At the end of the thesis the beamformer design is verified and it’s further usage is discused.
214

The correlation of sea surface temperatures, sea level pressure and vertical wind shear with ten tropical cyclones between 1981-2010

Compton, Andrea Jean 12 November 2013 (has links)
Indiana University-Purdue University Indianapolis (IUPUI)
215

Finite Element Modeling for Assessing Flood Barrier Risks and Failures due to Storm Surges and Waves

Wood, Dylan M. January 2020 (has links)
No description available.
216

Analysis of storm surge impacts on transportation systems in the Georgia coastal area

Restrepo, Ana Catalina 18 November 2011 (has links)
Many Climate Scientists believe that global warming will produce more extreme weather events such as tropical storms, hurricanes, intense rainfall, and flooding. These events are considered to be the most catastrophic natural events for transportation systems especially in coastal areas. Due to the severe damage from storm surge and flooding. Evaluating the magnitude of possible storm surges and their impacts on transportation systems in coastal areas is fundamental to developing adaptation plans and impact assessments to mitigate the damage. This thesis focuses on existing transportation systems in the Georgia coastal area that could be affected by several storm surges. An existing storm surge model is used to estimate the storm surges and the surge heights based on the category, direction, and forward speed of a storm. The ground elevation of the ports, interstates, state roads, railroads, and the principal airports on the Georgia coast are identified through a GIS analysis using the national elevation data set. Having the storm surge elevation and the elevation of the existing infrastructure, a GIS study is performed to identify those parts of the transportation system that will be affected by each type of storm giving results such as the length or sections of transportation assets under or above the surge elevation. A literature review of storm surge, rising sea levels, and their impacts on coastal bridges, roads, airports, ports, and railroads is presented in the thesis. Also, a description of the software used to analyze and estimate the impacts of climate change on transportation systems is described.
217

Ein Beitrag zum technologischen Konzept, zur Funktion und Berechnung hybrider Filterzyklone für die Partikelabscheidung aus Gasen / A contribution to the technological concept, function and calculation of hybrid filter cyclones for particle separation from gases

Emmrich, Jens 11 March 2015 (has links) (PDF)
Die Partikelabscheidung aus Gasen findet bei einer Vielzahl industrieller Prozesse Anwendung. Die im Bereich der Emissionsminderung für die Abscheidung fester Partikel zumeist herkömmlich eingesetzten Anlagen gleichen einander stark und werden häufig auch als Entstaubungsanlagen oder -einrichtungen bezeichnet. Diese bestehen vorwiegend aus eckigen Gehäusen mit intern positionierten Filterelementen. Zum Schutz und zur Entlastung der Filterelemente finden häufig interne Prallbleche bzw. externe Fliehkraftabscheider Verwendung. Kaum bekannt und untersucht hingegen ist die Kombination von filternder Technologie mit Fliehkraftabscheidern innerhalb eines Gehäuses. Die vorliegende Arbeit untersucht das technologische Konzept kombinierter Bauformen und entwickelt zwei weitere Varianten. Die wissenschaftliche Untersuchung von deren Funktion erfolgt am eigens entwickelten Versuchsstand. Die zusätzliche experimentelle Analyse einer herkömmlichen Entstaubungseinrichtung ermöglicht die Gegenüberstellung der unterschiedlichen technologischen Konzepte. Überdies erfolgt die Entwicklung und Validierung eines numerischen Berechnungsmodells sowie der Vergleich mit verfügbaren Standard-Berechnungsmodellen. Ferner findet das validierte numerische Berechnungsmodell bei der strömungstechnischen Analyse der experimentell untersuchten kombinierten Bauformen Anwendung. Letztendlich erfolgt auf Grundlage der Untersuchungsergebnisse die Definition von Vor- und Nachteilen sowie potentieller Anwendungsgebiete. Darüber hinaus werden für die zukünftige Dimensionierung allgemeingültige Regeln und eine Berechnungsvorschrift abgeleitet. / Particle separation of gases has been applied to a variety of industrial processes. Conventional concepts for the separation of solid particles resemble each other and are often referred to as dust collectors. They mainly consist of square housings with internal filter elements. For the protection and relief of the filter elements one often uses internal baffles and external cyclones. However, very little is known and studied regarding the combination of filtering technology and centrifugal separators within the same housing. This dissertation examines the state of the art of combined designs and presents the development of two further variants. Their scientific investigation took place on an especially designed test rig. An additional experimental analysis of a conventional dust collector allows the comparison of the developed different technological concepts. Moreover, experiments were carried out in order to develop and validate a numerical simulation model and to allow a comparison with available standard computational models. Furthermore, the validated numerical model has been applied to the aerodynamic analysis of the experimentally investigated combined designs. Moreover, based on the derived results, advantages and disadvantages as well as potential areas of application were identified. Eventually, some universal rules and a calculation rule have been derived for future designs and lay outs.
218

Nu får det vara slutlekt : Cybersäkerhetskraven för privata aktörer i ljuset av NIS2-direktivet / The Fun is Over : Cybersecurity Requirements for the Private Sector in light of the NIS2 Directive

Dison, Ellinor January 2023 (has links)
Cybersecurity threats have grown to become a global threat to private actors and states. While work processes are becoming more efficient, rapid technological developments are exposing network and information systems to vulnerabilities. The private sector plays a significant role in keeping the EU and Sweden safe in cyberspace since technological development is essentially controlled by private actors. When it comes to socially important activities, private actors both own and operate large parts of the market, which in turn means that attacks on private actors affecting trade secrets can pose a threat to market competition and economic prosperity. This thesis maps out how the EU has chosen to combat this with the NIS and NIS2 Directives. Specifically, this thesis maps out changes in cybersecurity requirements for private actors providing digital solutions in the light of NIS2. The previous NIS has shown to be inherently flawed with regards to the EU goal of achieving a high common level of security for network and information systems. The need for renewed legislation is therefore great and, as the investigation shows, NIS2 entails a change in the content, structure, and scope of important and essential entities. In short, the NIS2 Directive requires entities to perform their due diligence and document appropriate and proportionate measures based on an all-risk analysis. The increased and broadened requirements in NIS2, which are certainly justified by the increased cybersecurity threats, must also be weighed against an overly burdensome bureaucracy for authorities and private actors. In addition, this thesis analyzes the format of NIS2 and its potential impact on the internal market of the EU. Given the fact that it is a market regulation, a proportionality assessment is required in relation to the competitive disadvantages that an overly burdensome legislation may result in for private actors. At the same time, sanctions and enforcement measures must be sufficiently dissuasive. In conclusion, this thesis argues NIS2 to bring important changes, albeit still posing risks of further fragmenting the cybersecurity levels in the union due to the flexibility given to member states. However, NIS2 is a key step in the right direction towards achieving a high common level of cybersecurity across member states.
219

The Simulation & Evaluation of Surge Hazard Using a Response Surface Method in the New York Bight

Bredesen, Michael H 01 January 2015 (has links)
Atmospheric features, such as tropical cyclones, act as a driving mechanism for many of the major hazards affecting coastal areas around the world. Accurate and efficient quantification of tropical cyclone surge hazard is essential to the development of resilient coastal communities, particularly given continued sea level trend concerns. Recent major tropical cyclones that have impacted the northeastern portion of the United States have resulted in devastating flooding in New York City, the most densely populated city in the US. As a part of national effort to re-evaluate coastal inundation hazards, the Federal Emergency Management Agency used the Joint Probability Method to re-evaluate surge hazard probabilities for Flood Insurance Rate Maps in the New York – New Jersey coastal areas, also termed the New York Bight. As originally developed, this method required many combinations of storm parameters to statistically characterize the local climatology for numerical model simulation. Even though high-performance computing efficiency has vastly improved in recent years, researchers have utilized different “Optimal Sampling” techniques to reduce the number of storm simulations needed in the traditional Joint Probability Method. This manuscript presents results from the simulation of over 350 synthetic tropical cyclones designed to produce significant surge in the New York Bight using the hydrodynamic Advanced Circulation numerical model, bypassing the need for Optimal Sampling schemes. This data set allowed for a careful assessment of joint probability distributions utilized for this area and the impacts of current assumptions used in deriving new flood-risk maps for the New York City area.
220

Ein Beitrag zum technologischen Konzept, zur Funktion und Berechnung hybrider Filterzyklone für die Partikelabscheidung aus Gasen

Emmrich, Jens 12 December 2014 (has links)
Die Partikelabscheidung aus Gasen findet bei einer Vielzahl industrieller Prozesse Anwendung. Die im Bereich der Emissionsminderung für die Abscheidung fester Partikel zumeist herkömmlich eingesetzten Anlagen gleichen einander stark und werden häufig auch als Entstaubungsanlagen oder -einrichtungen bezeichnet. Diese bestehen vorwiegend aus eckigen Gehäusen mit intern positionierten Filterelementen. Zum Schutz und zur Entlastung der Filterelemente finden häufig interne Prallbleche bzw. externe Fliehkraftabscheider Verwendung. Kaum bekannt und untersucht hingegen ist die Kombination von filternder Technologie mit Fliehkraftabscheidern innerhalb eines Gehäuses. Die vorliegende Arbeit untersucht das technologische Konzept kombinierter Bauformen und entwickelt zwei weitere Varianten. Die wissenschaftliche Untersuchung von deren Funktion erfolgt am eigens entwickelten Versuchsstand. Die zusätzliche experimentelle Analyse einer herkömmlichen Entstaubungseinrichtung ermöglicht die Gegenüberstellung der unterschiedlichen technologischen Konzepte. Überdies erfolgt die Entwicklung und Validierung eines numerischen Berechnungsmodells sowie der Vergleich mit verfügbaren Standard-Berechnungsmodellen. Ferner findet das validierte numerische Berechnungsmodell bei der strömungstechnischen Analyse der experimentell untersuchten kombinierten Bauformen Anwendung. Letztendlich erfolgt auf Grundlage der Untersuchungsergebnisse die Definition von Vor- und Nachteilen sowie potentieller Anwendungsgebiete. Darüber hinaus werden für die zukünftige Dimensionierung allgemeingültige Regeln und eine Berechnungsvorschrift abgeleitet. / Particle separation of gases has been applied to a variety of industrial processes. Conventional concepts for the separation of solid particles resemble each other and are often referred to as dust collectors. They mainly consist of square housings with internal filter elements. For the protection and relief of the filter elements one often uses internal baffles and external cyclones. However, very little is known and studied regarding the combination of filtering technology and centrifugal separators within the same housing. This dissertation examines the state of the art of combined designs and presents the development of two further variants. Their scientific investigation took place on an especially designed test rig. An additional experimental analysis of a conventional dust collector allows the comparison of the developed different technological concepts. Moreover, experiments were carried out in order to develop and validate a numerical simulation model and to allow a comparison with available standard computational models. Furthermore, the validated numerical model has been applied to the aerodynamic analysis of the experimentally investigated combined designs. Moreover, based on the derived results, advantages and disadvantages as well as potential areas of application were identified. Eventually, some universal rules and a calculation rule have been derived for future designs and lay outs.

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