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1
Houssein, Abdi Yassin. "La côte continentale du Pertuis Breton, du début du XVIIIe siècle à la fin du Second Empire : évolution et aménagement du littoral depuis la Tranche-sur-Mer jusqu'au nord de La Rochelle." Electronic Thesis or Diss., La Rochelle, 2023. http://www.theses.fr/2023LAROS013.
Повний текст джерелаАнотація:
Entre le début du XVIIIe siècle et la fin du Second Empire, la côte continentale du Pertuis Breton connaît une évolution significative. Elle est constituée de trois paysages géomorphologiques singuliers, dynamiques et corrélés : un territoire marécageux, une zone dunaire et une côte à falaises. Ces milieux subissent des transformations naturelles lentes à l’origine de la constitution des flèches sableuses d’Arcay et de l’Aiguillon qui forment un grand cordon dunaire. Celui-ci est alimenté par un transport considérable des sables de l’ouest vers l’est par dérive littorale. Ces mouvements de sédiments sont soumis à l’influence d’agents hydrodynamiques. La remontée des eaux de l’océan entraîne le colmatage progressif du golfe des Pictons par des apports de sédiments d’origine fluvio-marine. Ce processus est à l’origine de la formation de l’anse de l’Aiguillon et du Marais poitevin. Ces milieux subissent également des transformations naturelles brutales dues à des phénomènes climatiques extrêmes. Cette étude met aussi en lumière la part de l’influence humaine dans l’évolution et la modification de leur trait de côte. Les aménagements sont particulièrement visibles dans le Marais poitevin. Entre le Moyen Âge et le XIXe siècle, ce territoire est l’enjeu d’une grande transformation qui modifie largement son écosystème. Cette zone humide est drainée par l’instauration de canaux, de digues et d’écluses. Grâce aux dessèchements réalisés par les sociétés des marais, l’agriculture et l’élevage connaissent un essor considérable et remplacent progressivement ces terres inondables réputées insalubres. Les marais connaissent alors un afflux de population. L'Etat est présent sur ce littoral par l’intermédiaire des Amirautés sous l’Ancien Régime ou de l’administration des Ponts et Chaussées au XIXe siècleBetween the beginning of the 18th century and the end of the Second Empire, the continental coast of the Pertuis Breton experienced a significant evolution. It is composed of three singular, dynamic and correlated geomorphological landscapes: a marshy area, a dune zone and a cliff coast. These environments underwent slow natural transformations which led to the creation of the sandy spits of Arcay and Aiguillon which form a large dune belt. The latter is fed by a considerable transport of sand from west to east by littoral drift. These sediment movements are subject to the influence of hydrodynamic agents. The rise in oceanic waters leads to the progressive clogging of the Gulf of the Pictons with sediment of fluvio marine origin. This process is at the origin of the formation of the Aiguillon Cove and the Poitevin Marsh. These environments also go through brutal natural transformations due to extreme climatic phenomena. This study also highlights the role of human influence in the evolution and modification of their coastline. Developments are particularly visible in the Marais Poitevin. Between the Middle Ages and the 19th century, this territory was the focus of a major transformation that greatly modified its ecosystem. This wetland was drained by the creation of canals, dykes and locks. Thanks to the draining carried out by the marsh companies, agriculture and livestock farming flourished and gradually replaced the flooded lands, which were considered unsanitary. The marshes then experienced an influx of people. The State is present on this coastline through the Admiralty under the Ancien Régime or the administration of the Ponts et Chaussées in the 19th century
2
Walter, Thomas. "Dental reference array." Diss., lmu, 2012. http://nbn-resolving.de/urn:nbn:de:bvb:19-139683.
Повний текст джерела
3
Liu, Guang. "Photovoltaic array simulators." Thesis, University of British Columbia, 1985. http://hdl.handle.net/2429/25103.
Повний текст джерелаАнотація:
Two basic types of photovoltaic (PV) array simulator have been designed and tested. The first involves the use of a pilot panel and variable light source. It is implemented with analogue circuits. A stability analysis based on Popov's method is presented for this simulator with resistance-inductance (R-L) loads. In the second, characteristic array curves are stored in the memory of a microprocessor-based simulator. The design of both simulators is based on the transfer function method. By using the computing facility available, a stability study for the Type I simulator and some dynamic simulations are carried out. Both simulators are capable of driving a special load, namely, an experimental solar pumping system. The experimental results for both types of' simulator are satisfactory in terms of steady state precision and dynamic behaviour when used with this load.
Compared with previously-reported PV array simulator designs [6,7,8,9,18], the two simulators described here have the following distinctive features:
1. A new method of sample curve generation for the Type II simulator results in relatively short sampling period and small memory size.
2. The sample curves of the type II simulator are based directly on the real PV array to be simulated. They are more accurate than the sample curves in references [6,7,9]. 3. Different loads (R, R-L and an experimental solar pumping system) have been considered in the design and have been tested in laboratory.
4. A stability analysis and some dynamic simulations are presented for the type I simulator. An analysis of this type has not been reported in previous studies [6,7,8,9,18].Applied Science, Faculty of
Electrical and Computer Engineering, Department of
Graduate
4
Manra, Vikas. "Efficient array-multipliers /." Available to subscribers only, 2006. http://proquest.umi.com/pqdweb?did=1240704201&sid=4&Fmt=2&clientId=1509&RQT=309&VName=PQD.
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5
Dowlut, Naushad Hussein. "Superresolution array design." Thesis, Imperial College London, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.266213.
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6
Wan, Shuang. "Parametric array calibration." Thesis, University of Edinburgh, 2011. http://hdl.handle.net/1842/4902.
Повний текст джерелаАнотація:
The subject of this thesis is the development of parametric methods for the calibration of array shape errors. Two physical scenarios are considered, the online calibration (self-calibration) using far-field sources and the offline calibration using near-field sources. The maximum likelihood (ML) estimators are employed to estimate the errors. However, the well-known computational complexity in objective function optimization for the ML estimators demands effective and efficient optimization algorithms. A novel space-alternating generalized expectation-maximization (SAGE)-based algorithm is developed to optimize the objective function of the conditional maximum likelihood (CML) estimator for the far-field online calibration. Through data augmentation, joint direction of arrival (DOA) estimation and array calibration can be carried out by a computationally simple search procedure. Numerical experiments show that the proposed method outperforms the existing method for closely located signal sources and is robust to large shape errors. In addition, the accuracy of the proposed procedure attains the Cram´er-Rao bound (CRB). A global optimization algorithm, particle swarm optimization (PSO) is employed to optimize the objective function of the unconditional maximum likelihood (UML) estimator for the farfield online calibration and the near-field offline calibration. A new technique, decaying diagonal loading (DDL) is proposed to enhance the performance of PSO at high signal-to-noise ratio (SNR) by dynamically lowering it, based on the counter-intuitive observation that the global optimum of the UML objective function is more prominent at lower SNR. Numerical simulations demonstrate that the UML estimator optimized by PSO with DDL is optimally accurate, robust to large shape errors, and free of the initialization problem. In addition, the DDL technique is applicable to a wide range of array processing problems where the UML estimator is employed and can be coupled with different global optimization algorithms.
7
Southwell, David Thomas. "Columnar array networks." Thesis, University of York, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.297157.
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8
Wang, Ji-yong 1967. "Hybrid ultrasonic array." Thesis, Massachusetts Institute of Technology, 2001. http://hdl.handle.net/1721.1/84216.
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9
Pacheco, Shaun, and Shaun Pacheco. "Array Confocal Microscopy." Diss., The University of Arizona, 2017. http://hdl.handle.net/10150/623252.
Повний текст джерелаАнотація:
Confocal microscopes utilize point illumination and pinhole detection to reject out-of-focus light. Because of the point illumination and detection pinhole, confocal microscopes typically utilize point scanning for imaging, which limits the overall acquisition speed. Due to the excellent optical sectioning capabilities of confocal microscopes, they are excellent tools for the study of three-dimensional objects at the microscopic scale. Fluorescence confocal microscopy is especially useful in biomedical imaging due to its high sensitivity and specificity. However, all designs for confocal microscopes must balance tradeoffs between the numerical aperture (NA), field of view (FOV), acquisition speed, and cost during the design process. In this dissertation, two different designs for an array confocal microscope are proposed to significantly increase the acquisition speed of confocal microscopes. An array confocal microscope scans an array of beams in the object plane to parallelize the confocal microscope to significantly reduce the acquisition time. If N beams are used in the array confocal microscope, the acquisition time is reduced by a factor of N. The first design scans an array of miniature objectives over the object plane to overcome the trade-off between FOV and NA. The array of objectives is laterally translated and each objective scans a small portion of the total FOV. Therefore, the number of objectives used in the array limits the FOV, and the FOV is increased without sacrificing NA. The second design utilizes a single objective with a high NA, large FOV, and large working distance designed specifically for whole brain imaging. This array confocal microscope is designed to speed up the acquisition time required for whole brain imaging. Utilizing an objective with a large FOV and scanning using multiple beams in the array significantly reduces the time required to image large three-dimensional volumes. Both array confocal microscope designs use beam-splitting gratings to efficiently split one laser beam into a number of equal energy outgoing beams, so this dissertation explores design methods and analyses of beam-splitting gratings to fabrication errors. In this dissertation, an optimization method to design single layer beam-splitting gratings with reduced sensitivity to fabrication errors is proposed. Beam-spitting gratings are typically only designed for a single wavelength, so achromatic beam-splitting grating doublets are also analyzed for possible use in array confocal microscopes with multiple excitation wavelengths. An analysis of the lateral shift between grating layers in the achromatic grating doublet proves grating profiles with constant first spatial derivatives are significantly less sensitive than continuous phase profiles. These achromatic grating doublets have designed performance at two wavelengths, but the diffraction angles at the two wavelengths differ. To overcome that limitation, scale-invariant achromatic gratings are designed, which not only provide designed performance at two wavelengths, but also equal diffraction angles at two wavelengths.
10
Willerton, Marc. "Array auto-calibration." Thesis, Imperial College London, 2013. http://hdl.handle.net/10044/1/11684.
Повний текст джерелаАнотація:
In this thesis, efficient methods are presented to calibrate large or small aperture array systems containing different types of uncertainties. specifically the challenge of reducing the number of external sources required to calibrate an array is addressed and array calibration methods suitable for use when sources may be operating in the "near-far" field of the array are developed. Together, this can ease the overheads involved in calibrating and recalibrating an array system. In addition to presenting novel array calibration algorithms, this thesis also presents a novel transformation allowing a planar array to be expressed as a virtual uniform linear array of a much larger number of elements. This allows the array manifold of a planar array, which in general consists of non-hyperhelical curves, to be expressed using a number of hyperhelices which each correspond to the array manifold of a linear array. This hyperhelical structure has the potential to ease calibration overheads as well as having many other potential applications in array processing. This thesis presents novel pilot and auto array calibration schemes for estimating different types of array uncertainties. A novel pilot calibration algorithm is proposed whereby a single source transmitting from a known location (i.e. a pilot) at two carrier frequencies is used to estimate geometrical uncertainties in a planar array. This is achieved by exploiting the frequency dependence on the boundary between the "near-far" and "far" field of the array. In addition, an auto-calibration method is presented which doesn't require any external sources to estimate array uncertainties. Here, geometrical, complex gain and local oscillator (i.e. frequency and phase) uncertainties associated with the array elements are considered. In this approach, array elements transmit in turn to the others which operate as an array receiver. Large and small array apertures are investigated. Throughout the thesis, extensive computer simulations are presented to analyse the performance of the algorithms developed.
11
Efstathopoulos, Georgios. "Extended array manifolds." Thesis, Imperial College London, 2008. http://hdl.handle.net/10044/1/11240.
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12
Sinclair, David Robert. "A study of the square kilometre array low-frequency aperture array." Thesis, University of Oxford, 2015. https://ora.ox.ac.uk/objects/uuid:7b5047f4-5643-49be-aea8-e31512180267.
Повний текст джерелаАнотація:
This thesis primarily comprises simulations of SKA1-Low, the low-frequency aperture array of the Square Kilometre Array (SKA) radio telescope. Simulations assess how different design specifications would affect the telescope's performance and ability to undertake one of its key science projects: observing the Epoch of Reionisation (EoR). The simulations are based on the previous baseline design of ~ 260 000 dipole antennas in 1024 stations of 256 antennas each. It is found that errors in the gain and phase of signals at each antenna can significantly affect observations, with the greatest impact at the lowest frequencies. The EoR signal will be detectable at limited redshifts with gain errors of 10% and phase errors of 6 degrees, however to ensure the systematic noise contribution from these errors is always weaker than the EoR signal between z ~ 10 - 21 and spherical harmonic multipole coefficients l ~ 102 - 104 , the gain and phase errors may need to be less than or equal to approximately 5 x 10-6 and less than or equal to approximately 3 x 10-4 degrees, respectively. Alternative telescope layouts to the SKA1-Low baseline design of 1024 stations containing 256 antennas each are evaluated. Some telescope models which share antennas between stations, allowing stations to be formed in a flexible manner, are found to provide superior thermal noise sensitivity than the current design, but suffer greater detrimental effects from gain and phase errors when imaging. The implementation of the digital signal processing of a station beamformer is also discussed. Calculations show that five or nine Field Programmable Gate Arrays (FPGAs) with specifications comparable to the Virtex UltraScale+ XCVU13P could be used to beamform a single 256-antenna SKA1-Low station, depending on the utilisation rate of the FPGAs and the number of channels required.
13
Goshi, Darren S. "Advanced retrodirective array and phased array architectures for wireless communication systems." Diss., Restricted to subscribing institutions, 2007. http://proquest.umi.com/pqdweb?did=1414125501&sid=1&Fmt=2&clientId=1564&RQT=309&VName=PQD.
Повний текст джерела
14
Dalevi, Mathias. "S-Band Antenna Array." Thesis, Uppsala University, Astronomy and Space Physics, 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-126302.
Повний текст джерелаАнотація:
This report presents concepts for a planar active electronically scanned antenna(AESA). The goal of the project was to devlop a low-weight, low profile, thin, S-band antenna with wide-scan angle capabilities. In the final concept the service aspects of the T/R-modules was also taken into acount in order to allow easy and fast replacements of these components. The antenna was designed and optimised using the commercial software Ansoft HFSS. A prototype of the antenna was constructed and later measured and verified. The final concept is a 2m×2m antenna with an estimated weight of around 320 kg, around 11 cm thick (where the thickness of the antenna element is 1.76 cm) and has a maximum scan angle range of more than 45 degrees (with <–10dB active reflection) in the frequency band 3–3.5 GHz.
15
Otsuka, Takuma. "Bayesian Microphone Array Processing." 京都大学 (Kyoto University), 2014. http://hdl.handle.net/2433/188871.
Повний текст джерелаАнотація:
Kyoto University (京都大学)0048
新制・課程博士
博士(情報学)
甲第18412号
情博第527号
新制||情||93(附属図書館)
31270
京都大学大学院情報学研究科知能情報学専攻
(主査)教授 奥乃 博, 教授 河原 達也, 准教授 CUTURI CAMETO Marco, 講師 吉井 和佳
学位規則第4条第1項該当
16
More, Daesha. "Microhotplate Sensor Array Fabrication." Fogler Library, University of Maine, 2007. http://www.library.umaine.edu/theses/pdf/MoreD2007.pdf.
Повний текст джерела
17
Hanson, Timothy B. "Cascade adaptive array structures." Ohio : Ohio University, 1990. http://www.ohiolink.edu/etd/view.cgi?ohiou1173207031.
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18
Mony, Madeleine. "Reprogrammable optical phase array." Thesis, McGill University, 2007. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=103276.
Повний текст джерелаАнотація:
The evolving needs of network carriers are changing the design of optical networks. In order to reduce cost, latency, and power consumption, electrical switches are being replaced with optical switching fabrics at the core of the networks. An example of such a network is an Agile All-Photonic Network (AAPN).This thesis presents a novel device that was designed to operate as an optical switch within the context of an AAPN network. The device is a Reprogrammable Optical Phase Array (ROPA), and the design consists of applying multiple electric fields of different magnitudes across an electro-optic material in order to create a diffractive optical element. The configuration of the electric fields can change to modify the properties of the diffractive device.
Such a device has a wide range of potential applications, and two different ROPA designs are presented. Both designs are optimized to function as 1xN optical switches. The switches are wavelength tunable and have switching times on the order of microseconds. The ROPA devices consist of two parts: a bulk electro-optic crystal, and a high-voltage CMOS chip for the electrical control of the device. The design, simulation, fabrication and testing of both the electrical and optical components of the devices are presented.
19
Alexiou, Angeliki. "Bounds in array processing." Thesis, Imperial College London, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.249378.
Повний текст джерела
20
Aytun, Alper. "Frequency diverse array radar." Thesis, Monterey, California. Naval Postgraduate School, 2010. http://hdl.handle.net/10945/5113.
Повний текст джерелаАнотація:
Approved for public release; distribution is unlimitedElectronic scanning is the most desirable feature of state-of-the-art radar systems. With electronic scanning, it is possible to steer the main beam of an array antenna instantaneously into a desired direction where no mechanical mechanism is involved in the scanning process. Electronic scanning methods including phase scanning, time delay scanning, and frequency scanning have been used in various radar applications; however new and cheaper scanning methods are still being investigated. It is the purpose of this thesis to investigate an array configuration called frequency diverse array (FDA), which gives rise to range-, time-, and angle-dependent scanning without using phase shifters. In this thesis, first, frequency diverse array as a time-modulated array is presented. A general analysis and the theory of time domain scanning is given. Equations derived for a time-modulated frequency diverse array are simulated using MATLAB. Amplitude tapering and Fourier series expansion is implemented in MATLAB and the results are provided for comparison. Secondly, analysis of a frequency diverse array is presented. Time-, range-, and angle-dependent electronic scanning is achieved by applying a small amount of frequency shift among the antenna elements. The simulation results for radiation patterns with various excitation types are given. Lastly, the radar applications of FDA are considered. The received power from a target at a fixed range is simulated in MATLAB and the results are presented.
21
Li, Yan 1978 July 15. "Gene expression array simulator." Thesis, Massachusetts Institute of Technology, 2002. http://hdl.handle.net/1721.1/87263.
Повний текст джерелаАнотація:
Thesis (M.Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, June 2002."May 10, 2002.
Includes bibliographical references (leaf 141).
by Yan Li.
M.Eng.
22
Fofonoff, Timothy Andrew 1977. "Brain microelectrode array systems." Thesis, Massachusetts Institute of Technology, 2003. http://hdl.handle.net/1721.1/41031.
Повний текст джерелаАнотація:
Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2003.Includes bibliographical references (leaves 110-114).
New methods for manufacturing microelectrode array assemblies, passive devices designed for intracortically recording brain activity in nonhuman primates, were developed and explored. Wire electrical discharge machining (EDM), chemical etching, micromilling, parylene deposition, and laser ablation were some of the processes employed to create distinctive microstructures with fine features and high aspect ratios. These microstructures, constructed from a variety of metals and polymers, were assembled to form the mechanical front end of a brain-machine interface (BMI). The developed techniques were used to produce microelectrode array assemblies for the Telemetric Electrode Array System (TEAS), a surgically implantable wireless device to be used for motor cortex studies in nonhuman primates. Two prototypes of the TEAS microelectrode array assemblies were implanted in animals in order to validate the design and the manufacturing processes. Neural activity was successfully recorded. Future work is required in order to refine and further automate the processes. Similar devices could one day develop into neural prostheses for clinical use by outputting motor intent captured from brain activity in paralyzed patients.
by Timothy Andrew Fofonoff.
S.M.
23
Rusholme, Benjamin Alan. "The very small array." Thesis, University of Cambridge, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.621310.
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24
Schluntz, Justine Oakley. "Tidal turbine array modelling." Thesis, University of Oxford, 2014. http://ora.ox.ac.uk/objects/uuid:b342fda1-a311-4783-8249-9b1515e0ad62.
Повний текст джерелаАнотація:
Computational fluid dynamics (CFD) is used in this thesis to model wind and tidal stream turbines and to investigate tidal turbine fence performance. There are two primary objectives of this work. The first is to develop and validate an actuator line method for the simulation of wind and tidal turbines which applies the blade forces to the flow field without the need for a regularisation kernel. The second is to examine tidal fences using, in part, the newly developed actuator line method. A potential flow equivalence method for determining the relative velocity to the blade chord and flow angle at the rotor blades in the actuator line method is proposed and validated. Results for simulations using this method compare favourably with those from both experiments and alternative computational methods, although the present model’s results deviate from experimental results in the vicinity of the blade tips. A CFD-embedded blade element-momentum tool is used to design rotors for operation in infinitely wide tidal fences spanning a tidal channel. Rotors are designed for fences with several different blockage ratios, with those designed for high blockage flows having greater solidity than those designed for operation in fences with lower blockage. It is found that designing rotors for operational blockage conditions can significantly improve the power output achieved by a tidal fence. Improved power output for higher blockage conditions is achieved by the application of greater thrust to the flow. Actuator line simulations of short (up to 8 turbines) fences with varying intra-rotor spacing and number of rotors confirm that hydrodynamic performance of the rotors improves as the spacing is reduced and as rotors are added to a fence. The position of a rotor within the fence impacts its performance; rotors at the ends of a fence extract reduced power compared to those at the centre of the fence, particularly for tip speed ratios greater than the design tip speed ratio.
25
Lin, Yuanzhi. "Active Antenna Oscillator Array." University of Cincinnati / OhioLINK, 2009. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1231873914.
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26
Smith, Edward J. "The diode array velocimeter." Thesis, This resource online, 1992. http://scholar.lib.vt.edu/theses/available/etd-09122009-040337/.
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27
Wanner, Shannon. "Phased array system design." [Ames, Iowa : Iowa State University], 2008. http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&res_dat=xri:pqdiss&rft_dat=xri:pqdiss:3383372.
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Peters, Allen G. "PHASED ARRAY 802.11g ANTENNA." DigitalCommons@CalPoly, 2010. https://digitalcommons.calpoly.edu/theses/334.
Повний текст джерелаАнотація:
This thesis involves the development of a 2.4GHz phased array antenna for consumer wireless applications. 802.11g specifications include 11 channels from 2.412 GHz to 2.472 GHz. Each channel has a 22MHz minimum bandwidth with a 5 MHz center-to-center interchannel spacing. Design goals for the phased array include an operating frequency of 2.437GHz (channel 6 center frequency). The array antenna design procedure can be integrated into a future antenna laboratory experiment.
Design considerations for the antenna array include cost, producibility, compatibility with 802.11b/g devices, and performance. Dipole antenna elements are arranged in a linear array to simplify calculations and to provide an intuitive understanding of array fundamentals. A linear array can maximize signal to interference ratio (SIR) by placing pattern nulls in the directions of noise sources. The design includes eight radiating elements mounted at λ/2 intervals. Design specifications include a scanning range of 360 degrees in the H-plane. Each element’s phase and gain is controlled by a network capable of 180 degrees of phase delay and up to 15.5dB of attenuation to enable sidelobe cancellation.
This project includes array design, simulations and theoretical calculations, antenna array construction, and final design characterization. Measurements are compared to theoretical predictions yielding good results. The antenna array was connected to an access point and tested on a lab network. Successfully associating a laptop to the wireless router and browsing the router configuration pages confirm connectivity. Array functionality is evaluated at channel 6, the 802.11g center frequency. The array is also tested at the lower and upper frequencies of channel 6 to ensure less than 3dB SNR variation.
The thesis includes a sample lab, which includes: A prelab, a procedure, and sample questions.
29
Masters, Joel T. "TOWER-TRACKING HELIOSTAT ARRAY." DigitalCommons@CalPoly, 2011. https://digitalcommons.calpoly.edu/theses/481.
Повний текст джерелаАнотація:
This thesis presents a method of tracking and correcting for the swaying of a central receiver tower in concentrated solar production plants. The method uses a camera with image processing algorithms to detect movement of the center of the tower. A prototype was constructed utilizing a CMOS camera connected to a microcontroller to control the movements of three surrounding heliostats. The prototype uses blob-tracking algorithms to detect and correct for movements of a colored model target. The model was able to detect movements in the tower with average error of 0.32 degrees, and was able to correctly orient the surrounding heliostats to within 1.2 and 2.6 degrees of accuracy while testing indoors and outdoors, respectively.
30
Johnson, Grayden L. "Network connected photovoltaic array." Thesis, Queensland University of Technology, 1994. https://eprints.qut.edu.au/36234/1/36234_Johnson_1994.pdf.
Повний текст джерелаАнотація:
This research project is primarily concerned with the construction, testing and analysis of Australia's first residential roof mounted 1.3 kW photovoltaic array which is connected, via its associated power conditioning equipment, to the utility's electrical distribution network. Also included in this project
was the establishment of computer-based data acquisition systems to be used for monitoring and analysis of essential data. The test facility (SOLAR ONE) was built within The South East Queensland
Electricity Board's (SEQEB) supply area and is situated at Mt Coolum. Work undertaken included a critical review of relevant literature concerned with the interconnection of photovoltaics with the electrical distribution
network, analysis of relevant electrical distribution authority's policy, regulation and guidelines; co-ordinating the building of the test facility,
building the array, installing the associated power conditioning and data acquisition equipment and ongoing monitoring including interpretation of data up to the date of this submission. The results presented demonstrate the applicability of photovoltaics within
the electrical distribution network. Also presented is the analysis of the data gathered from the test facility illustrating the effects of such a system upon the electrical distribution network.
31
Albannay, Mohammed Masoud. "Array of antenna arrays." Thesis, Queensland University of Technology, 2014. https://eprints.qut.edu.au/75576/1/Mohammed_Albannay_Thesis.pdf.
Повний текст джерелаАнотація:
Antenna arrays are groups of antenna elements spaced in a geometrical pattern. By changing the phase excitation of each element, the array is capable of transmitting electromagnetic waves strongly in a chosen direction with little or no radiation in another direction, thus controlling the array's radiation pattern without physically moving any parts. An antenna array of sub-arrays replaces conventional antenna elements with compact circular arrays with potential for improved performance.
This thesis expands on the concept by exploring the development, realisation and operation of an array of subarrays. The overall size of the array essentially remains the same, but the array's performance is improved due to having steerable directive subarrays. The negative effects of strong mutual coupling between closely spaced elements of a subarray are analysed and a number of new solutions for element decoupling are proposed.
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Consalter, Daniel Martelozo. "Implementação de aquisição paralelas de imagens utilizando bobinas de RF tipo phased array e sampled array." Universidade de São Paulo, 2017. http://www.teses.usp.br/teses/disponiveis/76/76132/tde-14092017-154855/.
Повний текст джерелаАнотація:
Técnicas de aquisição paralelas e hardware dedicados vem sendo desenvolvidos desde a década de 1980 para reduzir o tempo de aquisição de imagens via ressonância magnética (IRM). Uma bobina do tipo phased array é um dispositivo do tipo receptor, que usa múltiplas bobinas (canais) cada qual com seu próprio circuito de detecção para adquirir simultaneamente os sinais que formam uma imagem ou espectro via IRM. Exemplos de técnica de imagem paralela que usa bobinas tipo phased array são Sensitivy Enconding (SENSE) e GeneRalized Autocalibrating Partial Parallel Acquisition (GRAPPA). Sampled array é o nome de um método proposto neste trabalho em que cada canal de uma bobina multicanal é responsável por adquirir de forma independente o sinal da sua amostra de modo que cada sinal de amostra é endereçado ao seu canal específico. Neste trabalho, descrevemos o desenvolvimento de uma bobina phased array de quatro canais para anatomia de cabeça de rato usando circuito impresso flexível para operar em um sistema de IRM pré-clínico de 2T com objetivo de validar o método de construção e uso de circuito flexível como bobina de recepção. Também desenvolvemos uma bobina de quatro canais para realizar simultaneamente a imagem de quatro sementes na mesma varredura para validar o método Sampled Array com objetivo de melhorar a qualidade da imagem e simultaneamente acelerar experimentos de múltiplas amostras. Os resultados mostram que a bobina de circuito impresso phased array, em comparação com uma bobina de enrolamento de fio regular, forneceu uma boa relação sinal / ruído (RSR) e possui geometria mais adequada à anatomia por ser flexível. Além disso, o processo de fabricação da bobina seja facilitado desde que toda a bobina é construída como um protótipo de circuito impresso. Os bons resultados da bobina sampled array mostraram o método como promissor para imageamento de múltiplas amostras com aumento de RSR e diminuição de tempo de experimentos em relação ao uso de bobinas de canal único.Parallel techniques and dedicated hardware has been developed since the 1980s to reduce acquisition time on Magnetic Resonance Imaging (MRI) scanners. A phased array is a receiver only mode device concept, which uses multiple channels (coils) with their own detection circuits to simultaneously acquire MRI or localized spectroscopic signals. An example of parallel imaging technique that uses phased array coils is Sensitivy Enconding (SENSE). Sampled array is the name proposed in this work for a method in which each channel of a multichannel coil is responsible to acquire independently the signal from its sample so that each sample signal is addressed to its specific channel. In this work, we describe the development of a four-channel phased array coil for rat head anatomy using flexible printed circuit board (PCB), to operate on a 2T pre-clinical MRI scanner to validate the construction method and usage of flexible PCB as a receiver coil. We also developed a four-channel sample array coil to simultaneously perform the imaging of four seeds at the same scan, to validate the proposed method to improve image quality at the same time accelerating multiple seed imaging for agriculture studies. The results show that phased array PCB coil as compared to a regular wire winding coil provide good signal-to-noise ratio (SNR) imaging with more adequate geometry to the anatomy by being flexible. In addition, the coil manufacturing process is facilitated since the entire coil is constructed as a PCB prototype. The sample array imaging showed as a promising method for multiple sample increasing SNR and time to do experiments.
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Chen, Lixia. "Millimeter-Wave Wide Band Antenna Array for 5G Mobile Applications." Thesis, Université d'Ottawa / University of Ottawa, 2019. http://hdl.handle.net/10393/39446.
Повний текст джерелаАнотація:
The thesis presents a compact, miniature, and low cost antenna array designed for millimeter-wave frequencies for future 5th generation (5G) mobile applications. The proposed antenna array is a geometrically modified structure of the Franklin array, which allowed to transform a conventional narrowband array into a wideband antenna array. It is composed of five millimetre-wave circular patch radiation elements with phasing stubs.
The designed array, fabricated on the commercial Rogers RO3003 substrate with small form factor of 8x25x0.5 mm3, covers the upcoming 5G band of 23.6-30.3 GHz, with peak gain as 10.8 dB, and high radiation efficiency over the whole operating band. In addition, with frequency sweeping, the proposed antenna array radiation pattern is directive and offers beam steering at the desired angles, acting similarly as a leaky-wave antenna.
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Liang, Hongwei. "Development of microwave and millimeter-wave pin grid array and ball grid array packages." Diss., Georgia Institute of Technology, 2001. http://hdl.handle.net/1853/14867.
Повний текст джерела
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Kaur, Dilpreet. "Probing the Interstellar Medium Toward Timing Array Millisecond Pulsars with the Murchison Widefield Array." Thesis, Curtin University, 2021. http://hdl.handle.net/20.500.11937/88827.
Повний текст джерелаАнотація:
Millisecond pulsars are highly sought-after targets for timing-array experiments that aim to detect ultra-low frequency gravitational waves. However, there are multiple challenges before this goal can be achieved. Interstellar medium effects on pulsar signals are amongst them. The magnitudes of these effects are much stronger at longer radio wavelengths, therefore low-frequency observations with the Murchison Widefield Array are especially promising for the related studies. This thesis presents such a study for two millisecond pulsars.
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Kreuz, Markus. "Entwicklung und Implementierung von Auswertungswerkzeugen für Hochdurchsatz-DNA-Kopienzahl-Analysen und deren Anwendung auf Lymphomdaten." Doctoral thesis, Universitätsbibliothek Leipzig, 2015. http://nbn-resolving.de/urn:nbn:de:bsz:15-qucosa-161664.
Повний текст джерелаАнотація:
Aberrationen in der DNA-Kopienzahl sind häufige genetische Veränderungen bei malignen Lymphomerkrankungen. Zugewinne sowie Deletionen stellen dabei Mechanismen zur Onkogen-Aktivierung sowie Tumorsuppressorgen-Inaktivierung dar und tragen somit zur Pathogenese der Erkrankung bei. Array-CGH und SNP-Array sind Messplattformen, die die genomweite Bestimmung von Kopienzahlaberrationen in einem Experiment ermöglichen. Die bei der Analyse entstehenden Datensätze sind komplex und erfordern automatische Methoden zur Unterstützung der Analyse und Interpretation der Messergebnisse.
In dieser Promotionsarbeit wurden Methoden entwickelt, welche die Analyse von Array-CGH- und SNP-Array-Messungen ermöglichen. Diese Methoden wurden für die Auswertung umfangreicher Datensätze von malignen Non-Hodgkin-Lymphomen verwendet. Dabei wurden Lymphome der Entitäten Burkitt-Lymphom, diffus großzelliges B-Zell-Lymphom, Mantelzelllymphom, primäres ZNS-Lymphom und peripheres T-Zell-Lymphom – nicht anderweitig spezifiziert – analysiert. Für die untersuchten Lymphom-Entitäten konnten hierbei zahlreiche neue rekurrente Kopienzahlaberrationen sowie uniparentale Disomien gezeigt werden, die neue Einblicke in die Pathogenese der jeweiligen Erkrankungen erlauben.
Darüber hinaus erfolgte ein Vergleich beider Messplattformen anhand eines Datensatzes mit gepaarten Array-CGH- und SNP-Array-Daten. Für die eingesetzten Plattformen (2800k-BAC-Array vs. Affymetrix 250k-Sty-SNP-Array) konnte eine circa zwölffach höhere effektive Auflösung der SNP-Array-Plattform gezeigt werden. Die wesentlichen Ergebnisse dieser Arbeit sind in sieben Publikationen eingeflossen.
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Pajunpää, Kari. "Magnetometer array studies in Finland." Oulu, Finland : University of Oulu, 1989. http://catalog.hathitrust.org/api/volumes/oclc/20033413.html.
Повний текст джерела
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Micheli, Victor A. "Active phased array radar analysis." Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 1996. http://handle.dtic.mil/100.2/ADA318791.
Повний текст джерелаАнотація:
Thesis (M.S. in Systems Engineering) Naval Postgraduate School, September 1996.Thesis advisor(s): Chin-Hwa Lee. "September 1996." Includes bibliographical references (p. 59-63). Also available online.
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Cho, Jaeyoun. "Speech enhancement using microphone array." Columbus, Ohio : Ohio State University, 2005. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1132239060.
Повний текст джерела
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Samuelsson, Jacob. "Phased array antenna element evaluation." Thesis, Linköpings universitet, Fysik och elektroteknik, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-141690.
Повний текст джерелаАнотація:
This thesis evaluates two array antenna elements for large phased array antennas. The two antenna concepts are a surface mounted notch element and a PIFA (Planar Inverted F Antenna). The antennas have been simulated at S-band in Ansys HFSS as a unit cell in an infinite array environment. Thereafter, a finite 7 x 7 element array of the two concepts was simulated. A corresponding 49 element array, using the notch element, was built and measured upon. Embedded element patterns and S-matrix parameters have been measured. From this result, full array antenna patterns as well as active reflection coefficients have been calculated. The measurements show very good performance for large scan angles and a wide frequency range.
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Sabbar, Bayan M. "High resolution array signal processing." Thesis, Loughborough University, 1987. https://dspace.lboro.ac.uk/2134/27193.
Повний текст джерелаАнотація:
This study is concerned with the processing of signals received by an array of sensor elements which may range from acoustic transducers in a sonar system to microwave horns in a radar system. The main aim of the work is to devise techniques for resolving the signals arriving from closely spaced sources in order to determine the presence and direction of these sources.
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Shah, Rachana. "Investigations of Retrodirective Array Transponders." NCSU, 2002. http://www.lib.ncsu.edu/theses/available/etd-11072002-115845/.
Повний текст джерелаАнотація:
Retrodirective arrays, when illuminated by an interrogator signal, transmit a signal back towards the interrogator in the same direction as the incoming signal, without any prior knowledge of the source direction. With a retrodirective array the system efficiently transmits a signal without any digital signal processing. The added feature of being frequency autonomous allows it to transmit back at the same frequency as the incoming signal, without knowing the exact source frequency as well. The system is modelled using a system simulator from Elanix, SystemView Simulink. The system shows good retrodirectivity at various frequencies.
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Alghassi, Hedayat. "Eye array sound source localization." Thesis, University of British Columbia, 2008. http://hdl.handle.net/2429/5114.
Повний текст джерелаАнотація:
Sound source localization with microphone arrays has received considerable attention as a means for the automated tracking of individuals in an enclosed space and as a necessary component of any general-purpose speech capture and automated camera pointing system. A novel computationally efficient method compared to traditional source localization techniques is proposed and is both theoretically and experimentally investigated in this research.
This thesis first reviews the previous work in this area. The evolution of a new localization algorithm accompanied by an array structure for audio signal localization in three dimensional space is then presented. This method, which has similarities to the structure of the eye, consists of a novel hemispherical microphone array with microphones on the shell and one microphone in the center of the sphere. The hemispherical array provides such benefits as 3D coverage, simple signal processing and low computational complexity. The signal processing scheme utilizes parallel computation of a special and novel closeness function for each microphone direction on the shell. The closeness functions have output values that are linearly proportional to the spatial angular difference between the sound source direction and each of the shell microphone directions. Finally by choosing directions corresponding to the highest closeness function values and implementing linear weighted spatial averaging in those directions we estimate the sound source direction. The experimental tests validate the method with less than 3.10 of error in a small office room.
Contrary to traditional algorithmic sound source localization techniques, the proposed method is based on parallel mathematical calculations in the time domain. Consequently, it can be easily implemented on a custom designed integrated circuit.
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Hee, Ta Wei. "Wide bandwidth conformal array antennas." Thesis, University of Birmingham, 2008. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.521971.
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Middlebrook, Christopher. "INFRARED ANTENNA-COUPLED PHASED-ARRAY." Doctoral diss., University of Central Florida, 2007. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/3266.
Повний текст джерелаАнотація:
Phased-array antennas are commonplace in the radiofrequency portion of the electromagnetic spectrum. Exploitation of phasing effects between multiple antennas facilitates a wide range of applications, including synthetic-aperture radar, beam forming, and beam scanning. For the first time, the phased addition of multiple dipole antennas is demonstrated in the infrared, at a wavelength of 10.6 micrometers. Coplanar strip lines are used to interconnect the antennas, preserving the phase of the individual contributions. Several different proof-of-concept experiments are performed, using planar antennas fabricated with direct-write electron-beam lithography. Infrared-frequency currents from two dipole antennas are summed together at a common feedpoint and dissipated in a bolometric load. Angular pattern measurements show that the direction of maximum gain depends on the phase difference between the antennas. As more antennas are added together in phase, beam narrowing is observed in the angular response. Another experiment uses a two-dipole array to directly measure the magnitude of the mutual coherence function, at the plane of the antennas, of a spatially incoherent narrowband source. Measurements are also made of the broadside antenna response comparing air-side and substrate-side situations for a dipole antenna fabricated on a hemispherical immersion lens. In all cases, the measured behavior is confirmed by electromagnetic analysis.Ph.D.
Optics and Photonics
Optics and Photonics
Optics PhD
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Abram, Richard Henry. "High power waveguide array lasers." Thesis, Heriot-Watt University, 1998. http://hdl.handle.net/10399/622.
Повний текст джерела
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Karode, Shyam Lilachand. "Conformal retrodirective antenna array characterisation." Thesis, Queen's University Belfast, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.268151.
Повний текст джерела
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McAlernon, Patricia Mary. "Interpretation of array sensor responses." Thesis, Birkbeck (University of London), 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.266515.
Повний текст джерела
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Alkhammash, Hend Ibraheem. "Microfluidic white blood cell array." Thesis, University of Southampton, 2016. https://eprints.soton.ac.uk/419590/.
Повний текст джерелаАнотація:
The body’s defence against pathogens and foreign invaders is mediated by white blood cells (WBCs), one of the most important blood constituents. In blood, there is only one WBC for every 1000 red blood cells (RBCs), which makes WBC isolation a difficult task. Conventional isolation methods such as differential centrifugation, or selective lysis of RBCs could result in undesirable activation of WBCs and require a relatively large volume of blood. In this work, we present a microfluidic cross-flow trapping chip capable of selectively capturing WBCs in a dense array from whole blood without the prerequisite of RBCs lysis. This chip exploits the size and deformability difference between blood cells, and consists of a two-layer trapping system fabricated utilising standard photolithography and soft lithography. This array enables high-resolution imaging of individual live WBCs, obtained by taking a ~50 μl blood sample by fingerprick, and does not require cell drying or cell fixation as in a blood smear. In this work, a wide range of two-layered microfluidic devices has been fabricated and investigated in terms of blood cell arraying and imaging performance. Selective WBC capturing from a whole blood sample was achieved, for the first time, and the optimal geometry of the microfluidic channels for efficient WBC arraying was identified and related to hydrodynamic trapping theory. The developed WBC arrays were then used for the identification and enumeration of WBC subtypes on the basis of cell size and cell nucleus morphology, visualized by a combination of off-chip and on-chip dye staining, and also by labelling with antibodies against specific cell surface receptors. Furthermore, cells of nanoparticle-incubated blood samples were arrayed on the device and a preliminary analysis was performed of the association of these silica nanospheres with the different blood cell species, revealing significant differences in nanoparticle association. Moreover, sub-cellular imaging suggested a lysosomal nanosphere location in monocytes, implying nanoparticle uptake by endocytosis. Such studies have not previously been performed with arrayed WBCs, exemplifying that the WBC array developed in this work is a promising platform for single-cell (nano) biomedical studies with, for example, diagnostic imaging and drug discovery applications.
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Cavanaugh, Andrew F. "Inverse Synthetic Array Reconciliation Tomography." Digital WPI, 2013. https://digitalcommons.wpi.edu/etd-dissertations/278.
Повний текст джерелаАнотація:
This dissertation introduces Inverse Synthetic Array Reconciliation Tomography (ISART), an algorithm that exploits the short-time accuracy of inertial navigation systems (INS) and the time-stability of radio frequency (RF) positioning algorithms to achieve a high level of positioning accuracy. Novel array processing and data fusion techniques are employed to acheive performance far greater than RF and INS algorithms previously developed. This research is directed toward addressing the need for a viable tracking solution for firefighters and other first responders in urban and indoor environments. The approaches in this work are fundamentally different from other RF-INS fusion approaches, in the way we combine INS data with RF data. Rather than simply fusing the measurements from two systems that are estimating position (or states directly related to position) we use the inertial navigation data to improve the accuracy of our RF estimates at the signal level, before integrating them into an overall fusion system through the use of an extended Kalman filter (EKF). This work outlines the theoretical basis for ISART, and shows the results of simulations that support the claimed accuracy improvement of the ISART algorithm over existing methods. The viability of ISART in real world settings is then examined through the results of three field tests what were conducted in support of this research.