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Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 23 for “"Passive methods"”.
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A study on passive methods of vortex induced vibrations suppression
… vibrations of a cylinder in a fluid flow. Passive methods of altering the flow behavior around the structure to mitigate the hydrodynamic forces that cause VIV were considered. Structural enhancements to a cylinder were attempted to accomplish this goal. The study also aimed to reduce drag …
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Passive methods for suppressing acoustic resonance excitation in shallow rectangular cavities.
… at the cavity mouth. In this thesis, two passive methods for suppressing the flow-excited acoustic resonance phenomenon are addressed. The first passive method considers the edge geometry effect on the phenomenon. Several edge geometries including chamfered, round, and different …
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Deep learning for islanding detection of grid-connected photovoltaic systems
… the IEEE Standard. In the literature, several methods for islanding detection have been proposed, which can be classified as communication-based, active or passive methods. The communication-based methods are expensive to implement while the active methods typically inject harmonic distortion …
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Machine Learning Techniques for Gesture Recognition
… be digitized in a number of ways, including both passive methods, such as cameras, and active methods, such as wearable sensors. While passive methods might be the ideal, they are not always feasible, especially when dealing in unstructured environments. Instead, wearable sensors have gained …
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Analysis of flutter and flutter suppression via an energy method
… the desired operating envelope of the aircraft. Passive methods which have been used to solve the flutter problem include added structural stiffness, mass balancing, and speed restrictions. These methods may result in significant weight penalties. Studies by Boeing (ref. 1) show that weight …
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Teaching Methods and Partnership Development Patterns for Non-University Archivists
… The results show that the active learning methods of universities have largely been embraced by non-university archivists, but also show that the profession remains in flux in terms of training and transitioning away from more passive methods. This study can be used to implement or improve …
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A Novel Passive Islanding Detection Method Based on Phase-Locked Loop
… islanding. Among different islanding detection methods (IDMs), passive methods are the least intrusive and typically require the lowest investment cost. However, they generally suffer from larger non-detection zones (NDZs) and higher nuisance detection ratios as compared to active, hybrid, and …
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Feasibility study of long-life micro fuel cell power supply for sensor networks for space and terrestrial applications
… Negev, Israel. This research analyzes the use of passive methods to achieve thermal, air and water management for PEM fuel cells supplying power to these field sensors. The results of this study suggest that the proposed fuel cell power system is capable of providing power to sensor modules in …
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Quality of service assessment and analysis of wireless multimedia networks.
… technique was, subsequently, devised based on passive monitoring standard sampling methods. Unlike the active technique, the new method has the advantage of not adding an extra load to the network. In addition, it is not like the typical passive methods, which require the transfer and …
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Detecting and locating electronic devices using their unintended electromagnetic emissions
… of stimulated emissions is compared to passive detection techniques. The novel technique offers a 5 to 10 dB sensitivity improvement over passive methods for detecting radio receivers. The second section develops a radar-like technique for accurately locating radio receivers. The radar …
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Enalaprilat Improves Systemic and Mesenteric Blood Flow During Normotensive Resuscitation from Hemorrhagic Shock in Dogs
… Thermodilution-based and ultrasound-based methods of monitoring the systemic blood flow were also examined. Animals were hemorrhaged to a mean arterial pressure (MAP) of 40-45mmHg for 30min then 30-35mmHg for 30min followed by resuscitation with intermittent lactated Ringer's solution …
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Essex County Council primary schools (1973-1993): a design appraisal
… space standards, encouraged traditional teaching methods, and reduced community use. - The County Architect and Education department's influence diminished as power was delegated to individual schools. - Limited generic plans, including the paired classbase, have developed which are a useful …
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Application of adaptive trusses to vibration isolation in flexible structures
… vibration isolation in flexible structures. Passive methods have been used almost exclusively in the past for vibration isolation, although in the more recent literature active techniques have been proposed in an attempt to achieve greater isolation performance. Most of the active techniques, …
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Computational study of the effects of protruding studs casing treatment on the performance of an axial transonic turbofan
… withstand adverse operating conditions. Various methods have been devised in order to enhance compressor stability and increase compressor stall margin, usually with some sacrifice of performance and efficiency. Active methods make use of external devices injecting and/or bleeding air from the …
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Control And Topology Improvements In Half-bridge Dc-dc Converters
… of clamping techniques including both active and passive methods are presented after the ringing issues in DC-DC converters are investigated. By presenting the clamping techniques, a big variety of energy management concepts are introduced. The active bridge-capacitor tank clamping and …
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Prediction of low-frequency sound-pressure fields in fitted rooms for active noise control
… and even nausea from induced body vibrations. Passive methods of noise control, such as absorption or barriers, generally perform better at high frequencies, but are inadequate at low frequencies. A proposed solution is active noise control, which relies on destructive interference of sound …
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ENHANCEMENT OF CONVECTIVE HEAT TRANSFER IN INTERNAL FLOWS USING AN ELECTRICALLY-INDUCED CORONA JET
The enhancement of heat transfer by active and passive methods has been the subject of many academic and industrial research studies. Internal flows play a major role in many applications and different methods have been utilized to augment the heat transfer to internal flows. Secondary flows …
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Piezoceramic Actuated Transducers for Interior Acoustic Noise Control
… interior of the fairing. A major problem is that passive methods currently used for noise suppression do not exhibit significant energy dissipation at low frequencies. This motivates the use of active noise control. Using active noise control for frequencies below 200 to 300 Hz in addition to the …
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Design, Optimization, and Integration of a SiC-Based Traction Inverter with Enhanced Current Sharing for Paralleled Discrete Devices
… the current sharing analysis, Chapter 3 explores passive current-balancing methods to improve both static and dynamic current sharing. The layout for paralleled devices is first optimized by categorizing and comparing different layout types with a focus on minimizing parasitic loop inductance …
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Deformation-assisted antifouling of surfaces
… antifouling technique employed includes passive methods such as surface treatment or modification, the application of new surface materials, surface vibration, large deformation or heating (for deicing only) The problem of fouling is especially severe in the case of membrane processes due …
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