Dissertations / Theses on the topic 'Optical information processing system'
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Lord, Angus. "Localised states in nonlinear optical systems." Thesis, University of Strathclyde, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.248315.
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Yu, Donggang, and dyu@venus it swin edu au. "Processing and recognition of document and GIS images." Swinburne University of Technology, 2005. http://adt.lib.swin.edu.au./public/adt-VSWT20050812.095914.
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In intelligent document processing system and geographical information systems (GIS), the image processing and recognition play an important role. This thesis deals with various problems in processing images in documents and GIS: image smoothing, filling, linearization and extraction of contour features, extraction of structural points, separation and recognition of spurious segments in handwritten digits, reconstruction and recognition of broken digits, and separation and recognition of colour document and GIS images. These approaches are also called Optical Character Recognition (OCR).
A new smoothing technique is developed to smooth follow contours of image. With the new smoothing algorithms, spurious pixels (points) of contours are removed based on smooth patterns, and smooth followed contours are found. Also, skeletons of image can be smoothed between neighboring �end� and �junction� points. Smooth following makes linearization of smoothed contours possible based on Freeman codes.
A new filling algorithm of contours, project filling, is described based on two kinds of structural patterns. By this method, any complicated contours of images can be filled correctly.
Different from other linearization methods, linearization and feature extraction of smoothed contours are based on difference chain codes. Curvature and bend angles of linearized are found. The convexity and concavity of linearized are described. In this way, a series of description features of contours is formed.
Structural points are new and useful features to describe morphological structures between neighboring linearized lines. Extraction of structural points is based on structural patterns which are determined by element chain codes. Also, extension Freeman codes are used in this thesis. Structural points make description and recognition of contours possible.
In order to recognize handwritten digits in document processing systems, separation of spurious segments, reconstruction of broken digits and recognition of handwritten digits are investigated. Experiments with large number of testing data set show satisfactory results for these algorithms.
Separation and recognition of colour document and GIS images are discussed. Object images of document and GIS images are extracted based on the description of shape structures, prior knowledge and color information, which are associated with each other. Color images can be described by a limited number of colors in color document and GIS images. Therefore, separation of color image is done by color reduction method, and recognition of object images is based on structure patterns, prior knowledge and colour information. It can be seen that specific information should be considered in many practical problems to achieve better processing results.
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Jaisimha, M. Y. "Compound document retrieval in noisy environments /." Thesis, Connect to this title online; UW restricted, 1996. http://hdl.handle.net/1773/6007.
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Torzynski, Marc. "Reseaux de neurones formels : proprietes du modele de hopfield, realisations electroniques et optiques." Université Louis Pasteur (Strasbourg) (1971-2008), 1988. http://www.theses.fr/1988STR13230.
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On etudie un modele neuro-mimetique de traitement d'information, susceptible d'etre utilise comme une memoire associative. En premiere partie, on etudie les proprietes du modele et l'on quantifie la capacite memoire. Par simulation numerique, la tolerance du reseau a ses propres deficiences et ses facultes d'associativite. On montre theoriquement plusieurs points relatifs a l'information a l'aide d'une approche probabiliste du modele. En seconde partie, on etudie les possibilites d'implantation du modele
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Chaudhury, Souma. "Quantum Control and Quantum Chaos in Atomic Spin Systems." Diss., The University of Arizona, 2008. http://hdl.handle.net/10150/195449.
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Laser-cooled atoms offer an excellent platform for testing new ideas of quantum control and measurement. I will discuss experiments where we use light and magnetic fields to drive and monitor non-trivial quantum dynamics of a large spin-angular momentum associated with an atomic hyperfine ground state. We can design Hamiltonians to generate arbitrary spin states and perform a full quantum state reconstruction of the results. We have implemented and verified time optimal controls to generate a broad variety of spin states, including spin-squeezed states useful for metrology. Yields achieved are of the range 0.8-0.9.We present a first experimental demonstration of the quantum kicked top, a popular paradigm for quantum and classical chaos. We make `movies' of the evolving quantum state which provides a direct observation of phase space dynamics of this system. The spin dynamics seen in the experiment includes dynamical tunneling between regular islands, rapid spreading of states throughout the chaotic sea, and surprisingly robust signatures of classical phase space structures. Our data show differences between regular and chaotic dynamics in the sensitivity to perturbations of the quantum kicked top Hamiltonian and in the average electron-nuclear spin entanglement during the first 40 kicks. The difference, while clear, is modest due to the small size of the spin.
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Братова, Дар'я Романівна. "Формування вейвлет вікон для фільтрації оптичної інформації." Master's thesis, КиЇв, 2019. https://ela.kpi.ua/handle/123456789/30424.
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Дисертаційна робота присвячена розробці методу для оптичної обробки інформації.
В інженерній практиці для дослідження різноманітних сигналів природного та штучного походження застосовуються різні класи перетворень – Фур’є, Лапласа тощо. З 80-х років минулого століття для частотночасового аналізу нестаціонарних сигналів переважно використовують вейвлетперетворення (ВП). Першими це зробили Морле та Гроссман, займаючись аналізом сейсмічних даних та когерентними квантовими станами відповідно. Математичні засади ВП було закладено Мейєром, який показав існування відповідних функцій (вейвлетів), що утворюють ортогональний базис в просторі L2(R), тобто в просторі дійсних функцій, квадрат котрих є інтегрованим. Добеші здійснила перехід від неперервного до дискретного ВП та розробила клас вейвлетів, що мають максимальну гладкість при фіксованій довжині свого носія. Наразі область застосування ВП – наближення функцій і сигналів, їх фільтрація та стиснення, пошук в сигналі певних особливостей тощо.
Магістерська дисертація складається з чотирьох розділів.
У першому розділі проаналізовано основні переваги і недоліки вейвлет та Фур’є перетворень та особливості їх використання. Також приведено приклади основних типів вейвлетів.
У другому розділі приведено загальну класифікацію вейвлетів та кожного з загальних окремо. Окрім цього розглянуто узагальнені характеристики різноманітних вейвлетів та методи їх розрахунку.
Третій розділ присвячено розробці метода формування вейвлет вікон для фільтраціі оптичної інформації. В третьому підрозділі продемонстровані результати аналізу експериментальних робіт попередників, які показують можливість створення синтезованих цифрових нелінійних голограм у якості вейвлет-фільтрів.
Четвертий розділ присвячено розробці стартап-проекту «Формування вейвлет вікон для фільтрації оптичної інформації» і аналізу перспектив входження розробки на ринок з маркетологічної точки зору.The dissertation is dedicated to developing a method for optical information processing. In engineering practice, different classes of transformation - Fourier, Laplace, etc. - are used to investigate the various signals of natural and artificial origin. Since the 1980s, wavelet transform (WF) has been predominantly used for frequency analysis of unsteady signals. Morle and Grossman were the first to do so, analyzing seismic data and coherent quantum states, respectively. The mathematical foundations of the WT were laid down by Meyer, who showed the existence of corresponding functions (wavelets) forming an orthogonal basis in the space L2 (R), that is, in the space of real functions whose square is integrated. Dobeshi made the transition from continuous to discrete WT and developed a class of wavelets that have maximum smoothness at a fixed length of their carrier. Currently, the scope of the WT is the approximation of functions and signals, their filtering and compression, searching for a signal of certain features, and more. The master's thesis consists of four sections. The first section analyzes the main advantages and disadvantages of wavelet and Fourier transforms and the features of their use. Examples of the main types of wavelets are also given. The second section provides a general classification of wavelets and each of them in general. In addition, the general characteristics of various wavelets and their calculation methods are considered. The third section is devoted to the development of a method of forming wavelet windows for filtering optical information. The third section presents the results of an analysis of the previous experimental works that show the possibility of creating synthesized digital nonlinear holograms as wavelet filters. The fourth section is devoted to the development of a startup project "Formation of wavelet windows for filtering optical information" and to analyze the prospects of entering the market from a marketing point of view.
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Potter, Duncan J. "Phase-only optical information processing." Thesis, University of Edinburgh, 1993. http://hdl.handle.net/1842/845.
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Historically, much scientific work has been performed with two optical systems - the telescope and the microscope. Although Galileo was probably not the first to invent the refracting telescope, his rapid development of the instrument from 1609 results in his association as the father of the telescope today. Certainly he was the first human to view the giant moons of the planet Jupiter - Io, Ganymede, Callisto and Europa - and thus dare to venture our world was not the centre of the universe, and save our race from another thousand years of mysticism. A year later, in 1610, Galileo invented the microscope and this led to the new field of science called 'microscopy' to open up the previously unsuspected world of the ultra small. Tiny life forms no larger than a pinhead were revealed, and with instrumental improvements by later scientists the existance of bacteria proven. This discovery prompted the sterilisation of surgical equipment taken for granted today, saving countless millions of lives since then through freedom from bacterial infection. It is beyond doubt that the new world opened by the invention of the microscope inspired the scientists of that time to seek yet greater magnification and sharper images, to delve deeper into this tiny world. Yet technical improvement in the design of the microscope wase hampered by the lack of a proper theory of image formation. Not until the late nineteenth century, when ABBE and RAYLEIGH provided the foundations of the present day diffraction theory of imaging was the microcope properly understood. The work of this thesis has its roots in the developments of the early twentieth century microscopists. For many years they had observed tiny, transparent organisms and sought ways to improve the visibility of these creatures so that their nature might better be understood. The problem was solved by F.Zernike in 1935 (1, 425 for ref.) when he considered the way the organisms altered the phase of the illuminating light field. By the correct positioning of a thin phase-plate in the back focal plane of the microscope lens, Zernike demonstrated that optical thickness variations of the organism may be rendered visible as intensity variations. In this thesis , the light distribution in the back focal plane of such a lens that results from a transparent object is analysed in detail. From the expression derived by Zernike to explain the operating principle of his invention, we evaluate alternative formulations of the problem and proceed to a full analytical expression for the light field . Though mathematically awkward, it is shown the expression is not unworkable and several useful results are derived. In place of a microscope the study is based on imaging in a modern image processing bench, the physical principles involved being identical. Zernike introduced the idea of image modification through the use of a basic form of phase filter. The second half of this thesis develops this idea to show the use of much more intricate phase filters, which may be used to 'recognise' particular objects. Filter design is followed by experimental results on a special type of phase object, the programmeable Spatial Light Modulator.
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Le, Jeannic Hanna. "Optical Hybrid Quantum Information processing." Thesis, Paris 6, 2016. http://www.theses.fr/2016PA066596/document.
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Approche hybride du traitement quantique de l'information La dualité onde-particule a conduit à deux façons d'encoder l'information quantique, les approches continues et discrètes. L'approche hybride a récemment émergé, et consiste à utiliser les concepts et boites à outils des deux approches, afin de venir à bout des limitations intrinsèques à chaque champ. Dans ce travail de thèse, nous allons dans une première partie utiliser des protocoles hybrides de façon à générer des états quantiques non-gaussiens de la lumière. A l'aide d'oscillateurs paramétriques optiques, et de détecteur de photons supraconducteurs, nous pouvons générer des photons uniques extrêmement purs très efficacement, ainsi que des états chats de Schrödinger, qui permettent d'encoder l'information en variables continues. Nous montrons également en quoi des opérations de variables continues peuvent aider cette génération. La méthode utilisée, basée sur la génération " d'états-noyaux " rend en outre ces états plus robustes à la décohérence. Dans une seconde partie, dans le contexte d'un réseau hétérogène, basé sur différents encodages, relier de façon quantique les deux mondes, nécessite l'existence d'intrication hybride de la lumière. Nous introduisons la notion d'intrication hybride, entre des états continus et discrets, et nous en montrons une première application qui est la génération à distance de bit quantique continu. Nous implémentons ainsi également une plateforme polyvalente permettant la génération d'états " micro-macro " intriquésIn quantum information science and technology, two traditionally-separated ways of encoding information coexist -the continuous and the discrete approaches, resulting from the wave-particle duality of light. The first one is based on quadrature components, while the second one involves single photons. The recent optical hybrid approach aims at using both discrete and continuous concepts and toolboxes to overcome the intrinsic limitations of each field. In this PhD work, first, we use hybrid protocols in order to realize the quantum state engineering of various non-Gaussian states of light. Based on optical parametric oscillators and highly-efficient superconducting-nanowire single-photon detectors, we demonstrate the realization of a high-brightness single-photon source and the quantum state engineering of large optical Schrödinger cat states, which can be used as a continuous-variable qubit. We show how continuous-variable operations such as squeezing can help in this generation. This method based on so-called core states also enables to generate cat states that are more robust to decoherence. Second, in the context of heterogeneous networks based on both encodings, bridging the two worlds by a quantum link requires hybrid entanglement of light. We introduce optical hybrid entanglement between qubits and qutrits of continuous and discrete types, and demonstrate as a first application the remote state preparation of continuous-variable qubits. Our experiment is also a versatile platform to study squeezing-induced micro-macro entanglement
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Deng, Zhijie. "Novel optical devices for information processing." Texas A&M University, 2003. http://hdl.handle.net/1969.1/5863.
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Optics has the inherent advantages of parallelism and wide bandwidths in processing
information. However, the need to interface with electronics creates a bottleneck
that eliminates many of these advantages. The proposed research explores novel
optical devices and techniques to overcome some of these bottlenecks. To address
parallelism issues we take a specific example of a content-addressable memory that can
recognize images. Image recognition is an important task that in principle can be done
rapidly using the natural parallelism of optics. However in practice, when presented
with incomplete or erroneous information, image recognition often fails to give the
correct answer. To address this problem we examine a scheme based on free-space
interconnects implemented with diffractive optics. For bandwidth issues, we study
possible ways to eliminate the electronic conversion bottleneck by exploring all-optical
buffer memories and all-optical processing elements. For buffer memories we examine
the specific example of slow light delay lines. Although this is currently a popular
research topic, there are fundamental issues of the delay-time-bandwidth product
that must be solved before slow light delay lines can find practical applications. For
all-optical processing we examine the feasibility of constructing circuit elements that
operate directly at optical frequencies to perform simple processing tasks. Here we
concentrate on the simplest element, a sub-wavelength optical wire, along with a
grating coupler to interface with conventional optical elements such as lenses and
fibers. Even such a simple element as a wire has numerous potential applications. In conclusion, information processing by all-optical devices are demonstrated with
an associative memory using diffractive optics, an all-optical delay line using room
temperature slow light in photorefractive crystals, and a subwavelength optical circuit
by surface plasmon effects.
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Clark, Alex S. "Quantum information processing in optical fibres." Thesis, University of Bristol, 2011. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.557975.
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The use of quantum particles provides unprecedented improvements for some computational tasks and has applications in provably secure communications. The choice of quantum particles for such processes is wide but single photons are a promising candidate due to their extremely low decoherence and light speed trans- mission. Current technology for the generation and processing of single photons is of exceptional experimental interest and forms the basis of my investigations in this thesis. I show the background theory of quantum information and communication, with a general analysis of qubits and optical quantum gates before looking more specifically at different sources of photonic qubits and the generation of photons. I then show recent improvements in photon generation using photonic crystal fi- bres (PCFs), most especially the use of cross-polar phase matching solutions that allow the generation of pure state photons via four wave mixing effects in a X(3} nonlinear medium. These therefore require no spectral filtering to be used for quantum information tasks, thereby improving collection rates and experimental integration times which are crucial when performing multi-photon experiments. The optimization of the parameters for such a source are achieved through the use of an analytical model, and the purity of the photons are tested through the use of quantum interference effects. I move on to show the construction and character- ization of a common two qubit gate, namely the controlled-NOT gate, in optical fibres using fibre based sources and describe it's usefulness and integrability into quantum communication networks. I then calculate bounds on the average gate fidelity of 0.83 < Fave < 0.91 and create a model to show the main sources of error in the controlled-NOT gate operation. If the PCF used in the above sources is pumped in opposite directions in a Sagnac loop configuration, pairs of photons are generated in a maximally entangled Bell state where the polarization of one photon is perfectly correlated with the other photon of the pair. If two such pairs are generated in separate sources and one photon from each pair mixed on a polarizing beam splitter, a fusion operation is performed that entangles those two photons creating a four photon cluster state where all photons are entangled. This cluster state is a universal resource for measurement based quantum computing. In this thesis I show the generation and characterisation of such a cluster state and describe its use to perform a universal set of gates through single qubit measurements. I finally describe future experiments using PCFs and cluster states.
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Soutar, Colin. "Optical information processing using photorefractive BSO." Thesis, Abertay University, 1991. https://rke.abertay.ac.uk/en/studentTheses/a757b4d3-6c1e-4600-aed8-430e7078c6c5.
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Several optical information processing tasks are implemented using photorefractive BSO as a dynamic holographic medium. The physical basis for the mechanism which allows the implementation of these devices is studied. The properties of BSO which make it particularly attractive as a processing medium are highlighted, and experimental results are presented to demonstrate its practical limitations. An extensive study is presented of the influence of optical bias on the grating formation characteristics. This leads to a documentation of the optimum conditions for transient enhancement of a beam diffracted from such a grating. This transient enhancement can be controlled to provide ideal characteristics for the implementation of transient devices such as a novelty filter. A novelty filter utilising this transient enhancement is subsequently demonstrated. It exhibits good temporal discrimination through the choice of suitable external optical conditions, and the use of digital thresholding. The overall device operates at T.V. frame rates. Results are also presented of various optical correlators using BSO. These include the optical intensity correlator. The unique properties of the intensity correlator are stressed by practical demonstration. Specifically, the relative intolerance of the intensity correlator (compared with coherent correlators) to the position of the various components is demonstrated. Also, the spatially incoherent readout light allows the use of a low-optical quality liquid crystal television (LCTV) as a low-cost spatial light modulator. Output results are then presented from the correlator using the LCTV as a dynamic readout device. This provides an updateable hologram as the reference of the correlator which is interrogated at frame rates by the LCTV. Finally, the temporal discrimination of the novelty filter is combined with the character recognition ability of the intensity correlator. This produces an optical processor which will recognise a particular object but will only register it at the output stage when it is moving.
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Tian, Kehan. "Three dimensional (3D) optical information processing." Thesis, Massachusetts Institute of Technology, 2006. http://hdl.handle.net/1721.1/35627.
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Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2006.Includes bibliographical references (p. 141-151).
Light exhibits dramatically different properties when it propagates in or interacts with 3D structured media. Comparing to 2D optical elements where the light interacts with a sequence of surfaces separated by free space, 3D optical elements provides more degrees of freedom to perform imaging and optical information processing functions. With sufficient dielectric contrast, a periodically structured medium may be capable of forbidding propagation of light in certain frequency range, called band gap; the medium is then called a photonic crystal. Various "defects", i.e. deviations from perfect periodicity, in photonic crystals are designed and widely used as waveguides and microcavities in integrated optical circuits without appreciable loss. However, many of the proposed waveguide structures suffer from large group velocity dispersion (GVD) and exhibit relatively small guiding bandwidth because of the distributed Bragg reflection (DBR) along the guiding direction. As optical communications and optical computing progress, more challenging demands have also been proposed, such as tunable guiding bandwidth, dramatically slowing down group velocity and active control of group velocity. We propose and analyze shear discontinuities as a new type of defect in photonic crystals.
(cont.) We demonstrate that this defect can support guided modes with very low GVD and maximum guiding bandwidth, provided that the shear shift equals half the lattice constant. A mode gap emerges when the shear shift is different than half the lattice constant, and the mode gap can be tuned by changing the amount of the shear shift. This property can be used to design photonic crystal waveguides with tunable guiding bandwidth and group velocity, and induce bound states. The necessary condition for the existence of guiding modes is discussed. By changing the shape of circular rods at the shear interface, we further optimize our sheared photonic crystals to achieve minimum GVD. Based on a coupled resonator optical waveguide (CROW) with a mechanically adjustable shear discontinuity, we also design a tunable slow light device to realize active control of the group velocity of light. Tuning ranges from arbitrarily small group velocity to approximately the value of group velocity in the bulk material with the same average refractive index. The properties of eigenstates of tunable CROWs: symmetry and field distribution, and the dependence of the group velocity on the shear shift are also investigated.
(cont.) Using the finite-difference time-domain (FDTD) simulation, we demonstrate the process of tuning group velocity of light in CROWs by only changing the shear shift. A weakly modulated 3D medium diffracts light in the Bragg regime (in contrast to Raman-Nath regime for 2D optical elements), called volume hologram. Because of Bragg selectivity, volume holograms have been widely used in data storage and 3D imaging. In data storage, the limited diffraction efficiency will affect the signal-noise-ratio (SNR), thus the memory capacity of volume holograms. Resonant holography can enhance the diffraction efficiency from a volume hologram by enclosing it in a Fabry-Perot cavity with the light multiple passes through the volume hologram. We analyze crosstalk in resonant holographic memories and derive the conditions where resonance improves storage quality. We also carry out the analysis for both plane wave and apodized Gaussian reference beams. By utilizing Hermite Gaussian references (higher order modes of Gaussian beams), a new holographic multiplexing method is proposed - mode multiplexing.
(cont.) We derive and analyze the diffraction pattern from mode multiplexing with Hermite Gaussian references, and predict its capability to eliminate the inter-page crosstalk due to the independence of Hermite Gaussian's orthogonality on the direction of signal beam as well as decrease intra-page crosstalk to lower level through apodization. When using volume holograms for imaging, the third dimension of volume holograms provided more degrees of freedom to shape the optical response corresponding to more demanding requirements than traditional optical systems. Based on Bragg diffraction, we propose a new technique - 3D measurement of deformation using volume holography. We derive the response of a volume grating to arbitrary deformations, using a perturbative approach. This result will be interesting for two applications: (a) when a deformation is undesirable and one seeks to minimize the diffracted field's sensitivity to it and (b) when the deformation itself is the quantity of interest, and the diffracted field is used as a probe into the deformed volume where the hologram was originally recorded.
(cont.) We show that our result is consistent with previous derivations motivated by the phenomenon of shrinkage in photopolymer holographic materials. We also present the analysis of the grating's response to deformation due to a point indenter and present experimental results consistent with theory.
by Kehan Tian.
Ph.D.
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Davison, Alan Stephen. "All-optical signal processing devices." Thesis, University of Cambridge, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.316729.
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Arain, Muzamil Arshad. "INTERFEROMETRY-BASED FREE SPACE COMMUNICATION AND INFORMATION PROCESSING." Doctoral diss., University of Central Florida, 2005. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/3304.
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This dissertation studies, analyzes, and experimentally demonstrates the innovative use of interference phenomenon in the field of opto-electronic information processing and optical communications. A number of optical systems using interferometric techniques both in the optical and the electronic domains has been demonstrated in the filed of signal transmission and processing, optical metrology, defense, and physical sensors. Specifically it has been shown that the interference of waves in the form of holography can be exploited to realize a novel optical scanner called Code Multiplexed Optical Scanner (C-MOS). The C-MOS features large aperture, wide scan angles, 3-D beam control, no moving parts, and high beam scanning resolution. A C-MOS based free space optical transceiver for bi-directional communication has also been experimentally demonstrated. For high speed, large bandwidth, and high frequency operation, an optically implemented reconfigurable RF transversal filter design is presented that implements wide range of filtering algorithms. A number of techniques using heterodyne interferometry via acousto-optic device for optical path length measurements have been described. Finally, a whole new class of interferometric sensors for optical metrology and sensing applications is presented. A non-traditional interferometric output signal processing scheme has been developed. Applications include, for example, temperature sensors for harsh environments for a wide temperature range from room temperature to 1000 degree C.Ph.D.
Optics and Photonics
Optics
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Nicholas, Julian Jesuratnam. "Information processing in #parallel' visual pathways." Thesis, University of Oxford, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.386633.
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Gullans, Michael John. "Controlling Atomic, Solid-State and Hybrid Systems for Quantum Information Processing." Thesis, Harvard University, 2013. http://dissertations.umi.com/gsas.harvard:11146.
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Quantum information science involves the use of precise control over quantum systems to explore new technologies. However, as quantum systems are scaled up they require an ever deeper understanding of many-body physics to achieve the required degree of control. Current experiments are entering a regime which requires active control of a mesoscopic number of coupled quantum systems or quantum bits (qubits). This thesis describes several approaches to this goal and shows how mesoscopic quantum systems can be controlled and utilized for quantum information tasks.Physics
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Alic, Nikola. "Information processing for improved performance of optical networks." Connect to a 24 p. preview or request complete full text in PDF format. Access restricted to UC campuses, 2006. http://wwwlib.umi.com/cr/ucsd/fullcit?p3205498.
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Thesis (Ph. D.)--University of California, San Diego, 2006.Title from first page of PDF file (viewed April 4, 2006). Available via ProQuest Digital Dissertations. Vita. Includes bibliographical references (p. 151-158).
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Baker, Luke James. "Superconducting nanowire devices for optical quantum information processing." Thesis, University of Glasgow, 2018. http://theses.gla.ac.uk/8440/.
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Near infrared photons are a promising choice for quantum information processing; their low transmission loss is necessary for applications such as long distance Quantum Key Distribution (QKD) in optical fibre and integrated quantum optics. An ideal proof-of-concept test of such applications would be to create, manipulate and detect single photons on a monolithic chip. Superconducting nanowire single photon detectors promise high system detection efficiencies, low dark count and low jitter under near-infrared photon illumination. Superconducting nanowire devices using NbTiN films show improved coupling efficiencies with the aid of oxidized silicon cavities. NbTiN devices were characterised in a fibre-coupled package, achieving high SDE (43%) coherent key generation rates over 200km in a T12 QKD protocol simulation. Hairpin superconducting nanowires offer excellent integration with silicon waveguide optics and can achieve near unity absorption efficiencies. Hairpin devices fabricated from MoSi films were characterised using a custom pulse tube He-3 cryostat engineered for low vibration operation at 350mK and capable of near-infrared optical maps of superconducting nanowires. The devices exhibited high critical currents 40uA), low jitter (51ps) and a dark count rate <10cps. Tests of perpendicular coupling efficiencies yield low system detection efficiencies due to high coupling losses. Using an alternative coupling method via grating couplers or cleave mounting, it is expected a much higher system detection efficiency can be achieved.
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Mayer, Andreas. "Optimal immune systems : a ressource allocation and information processing view of immune defense." Thesis, Paris Sciences et Lettres (ComUE), 2017. http://www.theses.fr/2017PSLEE026/document.
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Les organismes biologiques ont développé divers mécanismes immunitaires afin de se protéger des pathogènes. Nous développons ici des modèles mathématiques de systèmes immunitaires, adaptés de façon optimale aux statistiques des pathogènes. Au delà des détails moléculaires, ces mécanismes immunitaires diffèrent dans la manière d'acquérir, de réguler et de transmettre une protection immunitaire ; différences qui pourraient s'avérer essentielles pour la survie à long terme. Afin d'expliquer la diversité des stratégies qui sont observées, nous comparons l'adaptation à long terme de populations en fonction de la dynamique des pathogènes à laquelle elles sont confrontées et de la stratégie immunitaire qu'elles adoptent. Nous démontrons que la fréquence et l'échelle de temps caractéristique des pathogènes sont les deux déterminants clés d'une stratégie immunitaire optimale. En fonction de ces deux paramètres, nous identifions des modes d'immunité distincts, comprenant immunités innées, adaptatives, ou ressemblant au système CRISPR, qui récapitulent la diversité de systèmes immunitaires naturels. Nos résultats viennent s'étendre à la question générale de l'évolution dans des environnements variables pour laquelle nous apportons de nouveaux résultats analytiques au sein d'environnements temporairement corrélés. Le système immunitaire adaptatif assure une protection à partir d'un large répertoire de cellules spécifiques à différents pathogènes. Pour prédire des propriétés statistiques de répertoires adaptés, nous étudions quel répertoire minimise au mieux le risque d'infections pour une distribution de pathogènes donnée. La théorie prédit que les cellules spécifiques contre les antigènes rares sont surreprésentées par rapport à la fréquence de leurs rencontres et que les individus, exposés aux mêmes infections, possèdent des répertoires avec des récepteurs largement différents mais exploitent la réactivité croisée afin de parvenir à la même couverture d'antigènes. Nos résultats sont issus d'une opposition entre les statistiques de détection des pathogènes, qui soutiennent l'idée d'une plus large distribution de récepteurs, et les effets de la réactivité croisée, qui tend à concentrer le répertoire optimal sur un petit nombre de clones. Nos prédictions peuvent être testées à partir d'enquêtes à haut débit sur la diversité des récepteurs et de pathogènes. Par la suite, nous examinons explicitement comment le système immunitaire adaptatif peut apprendre de manière bayésienne les statistiques de l'environnement à partir de l'historique des infections précédentes. Nous montrons que les répertoires optimaux peuvent être atteints par prolifération sélective des cellules spécifiques. La perspective bayésienne sur la dynamique des répertoires fournit un cadre conceptuel unificateur qui explique un certain nombre de caractéristiques de la mémoire immunitaire et appelle à des expériences complémentairesBiological organisms have evolved diverse immune mechanisms to defend themselves against pathogens. Here we build mathematical models of immune systems optimally tuned to the statistics of pathogens. Beyond molecular details, different immune mechanisms differ in how protection is acquired, processed and passed on to subsequent generations -- differences that may be essential to long-term survival. To explain the observed diversity of strategies we compare the long-term adaptation of populations as a function of the pathogen dynamics that they experience and of the immune strategy that they adopt. We find that the two key determinants of an optimal immune strategy are the frequency and the characteristic timescale of the pathogens. Depending on these two parameters, we identify distinct modes of immunity, including adaptive, innate, bet-hedging and CRISPR-like immunities, which recapitulate the diversity of natural immune systems. Our results carry over to the general question of evolution in fluctuating environments, for which we provide novel analytical results in temporally correlated environments. The adaptive immune system provides protection through a broad repertoire of cells specific to different pathogens. To predict statistical features of well-adapted repertoires we analyze which repertoire minimizes cost of infection for a given distribution of pathogens. The theory predicts that the immune system has more receptors for rare antigens than expected from the frequency of encounters; and individuals exposed to the same infections have sparse repertoires that are largely different, but nevertheless exploit cross-reactivity to provide the same coverage of antigens. Our results follow from a tension between the statistics of pathogen detection, which favor a broader receptor distribution, and the effects of cross-reactivity, which tend to concentrate the optimal repertoire onto a few highly abundant clones. These predictions can be tested in high throughput surveys of receptor and pathogen diversity. We then explicitly consider how the adaptive immune system can learn the statistics of the environments from its past infection history in a Bayesian manner. We show that optimal repertoires can be reached by keeping memory of an infection through the selective proliferation of stimulated cells. The Bayesian perspective on repertoire dynamics provides an unifying conceptual framework to explain a number of features of immunological memory and suggests further experiments
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Dai, Bo. "Optical code-division multiple access system and optical signal processing." Thesis, Heriot-Watt University, 2013. http://hdl.handle.net/10399/2663.
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This thesis presents our recent researches on the development of coding devices, the investigation of security and the design of systems in the optical cod-division multiple access (OCDMA) systems. Besides, the techniques of nonlinear signal processing used in the OCDMA systems fire our imagination, thus some researches on all-optical signal processing are carried out and also summarized in this thesis. Two fiber Bragg grating (FBG) based coding devices are proposed. The first coding device is a superstructured FBG (SSFBG) using ±π/2-phase shifts instead of conventional 0/π-phase shifts. The ±π/2-phase-shifted SSFBG en/decoders can not only conceal optical codes well in the encoded signals but also realize the reutilization of available codes by hybrid use with conventional 0/π-phase-shifted SSFBG en/decoders. The second FBG based coding device is synthesized by layer-peeling method, which can be used for simultaneous optical code recognition and chromatic dispersion compensation. Then, two eavesdropping schemes, one-bit delay interference detection and differential detection, are demonstrated to reveal the security vulnerability of differential phase-shift keying (DPSK) and code-shift keying (CSK) OCDMA systems. To address the security issue as well as increase the transmission capacity, an orthogonal modulation format based on DPSK and CSK is introduced into the OCDMA systems. A 2 bit/symbol 10 Gsymbol/s transmission system using the orthogonal modulation format is achieved. The security of the system can be partially guaranteed. Furthermore, a fully-asynchronous gigabit-symmetric OCDMA passive optical network (PON) is proposed, in which a self-clocked time gate is employed for signal regeneration. A remodulation scheme is used in the PON, which let downstream and upstream share the same optical carrier, allowing optical network units source-free. An error-free 4-user 10 Gbit/s/user duplex transmission over 50 km distance is reazlied. A versatile waveform generation scheme is then studied. A theoretical model is established and a waveform prediction algorithm is summarized. In the demonstration, various waveforms are generated including short pulse, trapezoidal, triangular and sawtooth waveforms and doublet pulse. ii In addition, an all-optical simultaneous half-addition and half-subtraction scheme is achieved at an operating rate of 10 GHz by using only two semiconductor optical amplifiers (SOA) without any assist light. Lastly, two modulation format conversion schemes are demonstrated. The first conversion is from NRZ-OOK to PSK-Manchester coding format using a SOA based Mach-Zehnder interferometer. The second conversion is from RZ-DQPSK to RZ-OOK by employing a supercontinuum based optical thresholder.
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Jacobo, Adrian. "Spatial structures and Information Processing in Nonlinear Optical Cavities." Doctoral thesis, Universitat de les Illes Balears, 2009. http://hdl.handle.net/10803/9436.
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Nazir, Ahsan. "Optical schemes for quantum information processing in semiconductor nanostructures." Thesis, University of Oxford, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.409819.
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Kalasuwan, Pruet. "Optical quantum information processing in higher dimensional Hilbert space." Thesis, University of Bristol, 2012. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.573150.
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In this thesis, we present and demonstrate several schemes for linear optical quantum information processing. Our schemes access. a higher-dimensional Hilbert space in order to simplify some particular quantum information tasks. We show how to expand a polarization-encoded cluster state by accessing and manipulating its spatial degree of freedom. This is realized using a polarization- path controlled-phase gate. We invented a method of adding control to quantum operations by accessing a higher dimensional Hilbert space, significantly reducing the complexity of some quantum circuits. A key advantage of this scheme is that control can be added even to unknown operations. This feature is required in some quantum information applications, such as the phase estimation algorithm, in which the phase is unknown. Using this method, we experimentally demonstrate a number of two-qubit photonic quantum gates, including a CNOT gate, CU gates, and entanglement filters and splitters. Using the same technique, we implemented the complete quantum phase estimation algorithm for a single qubit unitary, and we used the same circuit to realize an eigenstate generator. Our results point the way to efficient quantum simulations and quantum metrology in the near-term, and to large-scale quantum computations in the longer-term.
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Lowans, Brian Sinclair. "Applications of spatial light modulators in optical information processing." Thesis, Queen's University Belfast, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.282231.
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Miller, Paul Cecil. "Developments in optical information processing using spatial light modulators." Thesis, Queen's University Belfast, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.336128.
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McArdle, Neil. "Digital optical information processors : system optimisation and dynamic optical interconnections." Thesis, Heriot-Watt University, 1995. http://hdl.handle.net/10399/1321.
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Klein, Alexander. "Special purpose quantum information processing with atoms in optical lattices." Thesis, University of Oxford, 2007. http://ora.ox.ac.uk/objects/uuid:bc67ec3e-3cc7-4d13-ae11-b436b2ca897b.
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Atoms in optical lattices are promising candidates to implement quantum information processing. Their behaviour is well understood on a microscopic level, they exhibit excellent coherence properties, and they can be easily manipulated using external fields. In very deep optical lattices, each atom is restricted to a single lattice site and can be used as a qubit. If the lattice is shallow enough such that the atoms can move, their properties can be used to simulate certain condensed matter phenomena such as superconductivity. In this thesis, we show how technical problems of optical lattices such as restricted decoherence times, or fundamental shortcomings such as the lack of phonons or strong spin interactions, can be overcome by using current or near-future experimental techniques. We introduce a scheme that makes it possible to simulate model Hamiltonians known from high-temperature superconductivity. For this purpose, previous simulation schemes to realise the spin interaction terms are extended. We especially overcome the condition of a filling factor of exactly one, which otherwise would restrict the phase of the simulated system to a Mott-insulator. This scheme makes a large range of parameters accessible, which is difficult to cover with a condensed matter setup. We also investigate the properties of optical lattices submerged into a Bose-Einstein condensate (BEC). A weak-coupling expansion in the BEC-impurity interaction strength is used to derive a model that describes the lattice atoms in terms of polarons, i.e.~atoms dressed by Bogoliubov phonons. This is analogous to the description of electrons in solids, and we observe similar effects such as a crossover from coherent to incoherent transport for increasing temperatures. Moreover, the condensate mediates an attractive off-site interaction, which leads to macroscopic clusters at experimentally realistic parameters. Since the atoms in the lattice can also be used as a quantum register with the BEC mediating a two-qubit gate, we derive a quantum master equation to examine the coherence properties of the atomic qubits. We show that the system exhibits sub- and superdecoherence and that a fast implementation of the two-qubit gate competes with dephasing. Finally, we show how to realise the encoding of qubits in a decoherence-free subspace (DFS) using optical lattices. We develop methods for implementing robust gate operations on qubits encoded in a DFS exploiting collisional interactions between the atoms. We also give a detailed analysis of the performance and stability of the gate operations and show that a robust implementation of quantum repeaters can be achieved using our setup. We compare the robust repeater scheme to one that makes use of conventional qubits only, and show the conditions under which one outperforms the other.
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Paredes-Barato, David. "Towards optical quantum information processing using Rydberg dark-state polaritons." Thesis, Durham University, 2014. http://etheses.dur.ac.uk/10889/.
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This thesis proposes a novel method to implement universal quantum gates for photonic qubits using the strong dipole-dipole interactions present in a cold gas of Rydberg atoms and the control offered by microwave fields. By means of electromagnetically induced transparency (EIT) we store the information encoded in photonic qubits as Rydberg excitations, and then couple these to neighbouring states using microwaves. Microwaves alter the range of the dipole-dipole interactions between the excitations, and a suitable geometrical arrangement of the excitations in the cloud leads to a controlled π phase shift in the system's wavefunction, the basis of the universal gates proposed. After processing, the excitations in the medium are later retrieved as photons. A theoretical description of the implementation of a 2-qubit universal gate is presented and a numerical analysis shows the feasibility of its implementation in a cold cloud of Rubidium atoms. A scheme is also proposed to construct more general gates with applications in quantum information processing. These schemes have been made possible by the analysis of recent experiments performed in the group. This analysis is repeated here, along with the characterization of parts of the detection system required to obtain them.
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Watkins, L. R. "Optical fibre communications : signal processing to accommodate system impairments." Thesis, Bangor University, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.279143.
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Chaudhry, Mohammed Sabih. "Microwave I.F signal processing strategies for coherent optical communications." Thesis, Bangor University, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.357247.
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Leibrandt, David R. "Integrated chips and optical cavities for trapped ion quantum information processing." Thesis, Massachusetts Institute of Technology, 2009. http://hdl.handle.net/1721.1/53229.
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Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Physics, 2009.Cataloged from PDF version of thesis.
Includes bibliographical references (p. 145-158).
Quantum information processing is a new and exciting field which uses quantum mechanical systems to perform information processing. At the heart of the excitement are quantum computation - which promises efficient algorithms for simulating physical systems, factoring, and searching unsorted databases - and quantum communication - which provides a provably secure communications protocol. Trapped ions show much promise for achieving large-scale quantum information processing. Experiments thus far have demonstrated small algorithms and entanglement of two remote ions. Current work focuses on scaling to large numbers of ions for quantum computation and interconversion between trapped ions and photons for quantum communication. This thesis addresses some of the challenges facing scaling and interconversion for trapped ion quantum information processing. The first part of the thesis describes the development of scalable, multiplexed ion trap chips for quantum computation. The ion trap chips are based on a new ion trap geometry, called the surface-electrode trap, in which all of the electrodes reside in a single plane. Three generations of surface-electrode traps are designed, fabricated, and tested - culminating with the demonstration of an ion trap chip microfabricated using standard silicon VLSI materials and processes for scalability to small trap size and large arrays of interconnected ion traps. The second part of the thesis presents an experiment that demonstrates cavity cooling, a method of laser cooling the motional state of trapped ions without decohering the internal qubit state.
(cont.) Cavity cooling is demonstrated for the first time with trapped ions, and for the first time in the parameter regime where cooling to the motional ground state is possible. The measured cavity cooling dynamics are found to agree with a rate equation model without any free parameters. The third and final part of the thesis presents a theoretical proposal for interconversion between single trapped ion qubits and single photon qubits for quantum communication. The idea is to map the state of the single ion qubit to a superradiant collective state of several ions, which then couples strongly with single photons in an optical cavity.
by David R. Leibrandt.
Ph.D.
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Holmer, Stefan. "Implementation and evaluation of content-aware video retargeting techniques." Thesis, Linköping University, Department of Electrical Engineering, 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-15230.
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The purpose of this master thesis was to study different content-aware video retargeting techniques, concentrating on a generalization of seam carving for video. Focus have also been put on the possibility to combine different techniques to achieve better retargeting of both multi-shot video and single-shot video. This also involved significant studies of automatic cut detection and different measures of video content. The work resulted in a prototype application for semi-automatic video retargeting, developed in Matlab. Three different retargeting techniques, seam carving, automated pan & scan and subsampling using bi-cubic interpolation, have been implemented in the prototype. The techniques have been evaluated and compared to each other from a content preservation perspective and a perceived quality perspective.
Syftet med examensarbetet har varit att studera tekniker för ändring av bredd/höjd-förhållandet i videosekvenser, där hänsyn tas till innehållet i bilderna. Fokus har lagts på en generalisering av "seam carving" för video och möjligheterna att kombinera olika tekniker för att nå bättre kvalitet både för videosekvenser som består av endast ett, eller flera, klipp. Detta innefattade således också omfattande studier av automatisk klippdetektering och olika mått av videoinnehåll. Arbetet har resulterat i en prototypapplikation utvecklad i Matlab för halvautomatisk förändring av bildförhållande där hänsyn tas till innehållet i sekvenserna. I prototypen finns tre metoder implementerade, "seam carving", automatiserad "pan & scan" och nedsampling med bi-kubisk interpolering. Dessa metoder har utvärderats och jämförts med varandra från ett innehållsbevarande perspektiv och ett kvalitetsperspektiv.
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Qureshi, Faisal. "The nonlinear optical properties of conjugated molecular materials." Thesis, University of Sheffield, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.264642.
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Cheung, Chi-wa John. "Transport information system in Hong Kong." Hong Kong : University of Hong Kong, 2000. http://sunzi.lib.hku.hk/hkuto/record.jsp?B22200241.
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Ranshaw, M. J. "Phase-modulating spatial light modulators." Thesis, University of Edinburgh, 1988. http://hdl.handle.net/1842/14252.
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Khendek, Hamid. "Computer optical-vision system for glass measurement and inspection." Thesis, University of Nottingham, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.283378.
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BRUHNS, THOMAS VICTOR. "HARDWARE AND SOFTWARE FOR A COMPUTER CONTROLLED LIDAR SYSTEM." Diss., The University of Arizona, 1985. http://hdl.handle.net/10150/188042.
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The hardware and software for a computer controlled optical radar, or lidar, system are described. The system builds on a previously installed pulsed ruby backscatter lidar, capable of acquiring data at controlled azimuth and elevation angles through the atmosphere. The described system replaces hardwired logic with computer control. Two coupled computers are used to allow a degree of real time control while data are processed. One of these computers reads and controls mount elevation angle, reads the laser energy monitor, and senses firing of the laser. The other computer serves as a user interface, and receives the lidar return data from a digitizer and memory, and the angle and energy information from the other computer. The second computer also outputs data to a disc drive. The software provided with the system is described, and the feasibility of additional software for both control and data processing is explored. Particular attention is given to data integrity and instrument and computer operation in the presence of the high energy pulses used to drive the laser. A previously described laser energy monitor has been improved to isolate it from laser transients. Mount elevation angles are monitored with an absolute angle readout. As a troubleshooting aid, a simulator with an output that approximates the lidar receiver output was developed. Its output is digitally generated and provides a known repetitive signal. Operating procedures are described for standard data acquisition, and troubleshooting is outlined. The system can be used by a relatively inexperienced operator; English sentences are displayed on the system console CRT terminal to lead the operator through data acquisition once the system hardware is turned on. A brief synopsis of data acquired on the system is given. Those data are used as the basis of other referenced papers. It constitutes soundings for over one hundred days. One high point has been operation of the system in conjunction with a balloon borne atmospheric particulate sampling package. The system has also been used occasionally as the transmitter of a lidar system with physically separated receiver and transmitter.
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Sadri, Saeid Lonbani. "An Integrated information system for building construction projects." Diss., Georgia Institute of Technology, 1993. http://hdl.handle.net/1853/19468.
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Humphreys, Peter Conway. "Experimental and theoretical techniques for quantum-enhanced metrology and optical quantum information processing." Thesis, University of Oxford, 2015. https://ora.ox.ac.uk/objects/uuid:57e942ac-f6f1-43fe-ac77-ef85b7db85ca.
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Over the last few decades, quantised excitations of the electromagnetic field have proven to be an ideal system with which to investigate and harness quantum optical phenomena. The techniques developed have enabled fundamental tests of quantum mechanics as well as practical applications in quantum metrology and quantum information processing. Advancing to larger-scale entangled quantum systems will open up new regimes of quantum many-body physics, allowing us to probe the limits of quantum mechanics and enabling truly quantum-enhanced technologies. However, moving towards this goal will require further experimental and theoretical innovations. The work described in this thesis focuses on several different aspects of optical quantum information, but are ultimately all linked by this long-term aim. The first part of this thesis describes a novel method for strain-based active control of quantum optical circuits and a new method for the characterisation of high efficiency detectors. Building on this, I discuss in detail two different fields of quantum optics that stand to benefit from these techniques. I initially consider quantum-enhanced metrology, including work aimed towards demonstrating a truly better-than-classical phase measurement, and a theoretical exploration of multiple-phase estimation. Finally, I focus on linear-optical quantum information processing, exploring in detail the use of time-frequency encodings for quantum computing.
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Rijhwani, Vishal. "A biologically inspired optical flow system for motion detection and object identification." Diss., Columbia, Mo. : University of Missouri-Columbia, 2007. http://hdl.handle.net/10355/5064.
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Thesis (M.S.)--University of Missouri-Columbia, 2007.The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file (viewed on April 7, 2008) Includes bibliographical references.
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Hu, X. (Xiaori). "Tourism information system from integration viewpoint:a constructive case study." Master's thesis, University of Oulu, 2013. http://urn.fi/URN:NBN:fi:oulu-201310171796.
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As the rapid economic development of tourism industry in recent years, and gradually increasing user needs to tourism products and services, a variety of Tourism Information Systems (TISs) have been available. However, less attention is focused on these TISs from integration viewpoint, since currently most TISs are independent or isolated from the user’s perspective, tourists have to enter separately into different TISs in order to make a complete travel plan and get related tourism services. Advanced, Smart Tourism Information Systems (STISs) provide all tourism-related products and services in the unified system environment.
This constructive case study proposes a framework for STIS including theoretical analyses of the core elements and components of the systems, and provides several potential development approaches to and recognized challenges as developing STISs. Interview-based scenarios with potential users are used to demonstrate the needs of independent travellers and in showing for which purposes the different systems should be integrated. The results show that the developed framework of STIS is promising and can be useful when integrating the systems as offering one-stop services for independent tourists. More research with a wider empirical sample is still required to generalize the results and test the framework in practice.
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Wang, Junxian. "Online hotel booking system." CSUSB ScholarWorks, 2006. https://scholarworks.lib.csusb.edu/etd-project/3083.
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The Online Hotel Booking System was developed to allow customers to use a web browser to book a hotel, change the booking details, cancel the booking, change the personal profile, view the booking history, or view the hotel information through a GUI (graphical user interface). The system is implemented in PHP (Hypertext Preprocessor) and HTML (Hyper Text Markup Language).
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Cathey, Jack M. "Contingent factors affecting budget system usefulness: an information processing perspective." Diss., Virginia Polytechnic Institute and State University, 1989. http://hdl.handle.net/10919/54503.
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An examination of the management accounting systems literature revealed the need for additional research based on a contingency perspective. Specifically, additional empirical research based on a well-articulated theory.
A theoretical model was developed building on Galbraith’s theory of organization structure. Two sources of uncertainty -- environmental uncertainty and task uncertainty -- were viewed as forming the information processing requirements faced by the organization. In response to these requirements, organizations were viewed as adapting by altering their level of decentralization and their use of budget systems. Organizational effectiveness was achieved by a proper fit between the uncertainty faced by the organization and these responses.
Data were collected from business unit managers using a survey instrument. A total of 103 usable responses were obtained with an overall response rate of 49%. Previously developed measures were used for all variables except for budget system usefulness. A measure for this variable was developed and validated. The data were examined using path analysis.
The data did not support the model. Problems encountered in the use of perceptual measures for the uncertainty variables appeared to be the most likely explanation for the weak results. However, when the data was split based on the performance measure an interesting result was observed. Specifically, the relationships between the uncertainty measures, decentralization, and budget system usefulness were different for the low and high-performance group. An explanation for this tinding was offered.Ph. D.
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Li, Xiaofeng. "Information processing and distribution in the fly early visual system." Thesis, University of Sheffield, 2011. http://etheses.whiterose.ac.uk/2217/.
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Evolution shapes biological systems to better match their desired functions. Hence, we can assume that sensory systems are adapted to optimize information processing. Nevertheless surprisingly little is known about how sensory systems are optimised, or organised, in relation to the information sampling and processing they perform. In particular, our understanding is limited on certain fundamental issues: (1) what are the roles of individual ionchannels in coding information in specialised neural networks, (2) how does information transfer through synapses, and (3) how are different types of information (motion/colour) routed and processed for higher order visual functions. Dipteran compound eyes provide highly useful model systems for examining the basic mechanisms involved in visual information processing; in particular, for assessing how graded potentials code visual information. For this thesis, I have performed extracellular and intracellular recordings from photoreceptors and their primary interneurones, large monopolar cells (LMC), in Calliphora and Drosophila, to investigate the three essential questions mentioned above. This thesis provides systematic characterisations of: (1) Drosophila dSK channels, small conductance calcium-activated potassium channels; (2) Adapting dynamics of postsynaptic quantal bumps in the first visual synapse in Calliphora; (3) in vivo spectral sensitivities of Drosophila R1-R6 photoreceptors and LMCs in wild-type and in selected mutant and transgenic flies. Together with collaborations inside/outside our laboratory, my study: (1) identified the functional roles and gain control of dSK channels in the first synaptic circuits in the fly eye and also clarified how intrinsic activities of neural network compensates for missing or faulty ion channels; (2) characterised how postsynaptic unitary voltage events (or bumps) adapted dynamically to maximize the rate of information transfer at the fly first visual synapse; 3) provided the first in vivo spectral sensitivity functions of Drosophila R1-R6 photoreceptors and LMCs, and demonstrated that functional inputs, from photoreceptors that have different spectral sensitivities, improve motion discrimination and robustness of perception.
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AKANNI, ISA SADEEQ. "Information system development for optical character recognition using Fourier descriptors." Thesis, Тернопільський національний технічний університет імені Івана Пулюя, 2017. http://elartu.tntu.edu.ua/handle/123456789/19538.
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Optical character recognition has many different practical applications. The main areas where OCR has been of importance, are text entry (office automation), data entry (banking environment) and process automation (mail sorting).
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Korvala, T. (Tapio), and H. (Hannu) Raappana. "Open visual guidance system for mobile senior citizen." Master's thesis, University of Oulu, 2015. http://urn.fi/URN:NBN:fi:oulu-201505211603.
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The elderly citizen’s health care need some radical changes and improvements to alleviate the situation where the quality of service must be enhanced without overburdening the caregivers under the weighty workload. Much of research is done and many researchers all around the world emphasize the importance of assistive technologies. Current technological advancements in communication allow us to build systems which could be useful tools for the caregivers and allow the elderly to live more autonomous and active life. Offering stimulus to the elderly to experience with the technology could lessen the feel of social isolation and ameliorate the quality of service significantly. Shrinking electronics, mobiles and sensors do not bound the use only in homes or facilities, but allow the use in many different environments. While using technology of this kind, the caregivers could give guidance or follow the health status of a mobile elderly citizen in remote fashion and give help if needed. This thesis is also immersing in the matter by producing a Visual Guidance system that utilizes current mobile technology, actuators, sensors and uses a virtual reality as a communication medium between the caregivers and elderly citizens.
The system consists of two different parts combined together to form a real-time communication system between caregivers and elderly citizen. The system uses Android smart phone’s built-in sensors to track the movement of the elderly. Those sensors are location based sensors such as GPS and acceleration and magnetometer sensors. This system provides an open map view of the world where the elderly citizen move. Also to improve the communication between the elderly and caregiver, video and audio communication has been used as one of our research aims. The caregiver can remotely use the smart phone to open video and audio communication with the elderly if needed. The system has been integrated with indicator base smart glasses so that when the elderly citizen are on the move, the caregiver can give directional advices on where and when to go.
The authors used integration testing to evaluate the system and comparing the current system functions with the requirements of the system. Also the authors made sure that the delay with communication was small enough so it would be safe for the caregivers to communicate with the elderly citizen.
For future work we suggested various actions such as integrating indicator based glasses with the Pupil Pro glasses, finding the most appropriate security solutions for the system and testing the system with real-life caregivers and elderly citizen.
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Palani, Ananta. "Development of an optical system for dynamic evaluation of phase recovery algorithms." Thesis, University of Cambridge, 2015. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.708850.
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Deng, C. (Canrong). "Multi user support for senior citizen visual guidance system." Master's thesis, University of Oulu, 2016. http://urn.fi/URN:NBN:fi:oulu-201603251353.
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Due to the population aging phenomenon, the working-age population will decline in the future while the seniors’ quality of life can decline. A lot of research has been done and many of researchers figure out modern ICT and mobile technology needs to shoulder more responsibility in elderly care. The benefit of science and technology should be brought to senior citizens’ life.
Moreover, the smartphone ownership rate has been increasing in recent years, espe- cially the percentage of Android phone ownership. Because elders will take smart- phone everywhere, installing an application in senior citizen’s Android phone is a good way to track their movements. The caregivers could give guidance remotely to elders based on their location and surrounding environment scene by using mobile technology of this kind.
The multi user support for senior citizen visual guidance system consists of five components: Android phone, Pupil headset, Indicator-based Glasses, OldBirds and web server part. The system uses the Pupil headset to capture senior citizen’s font view and transfer it to OldBirds part which is controlled by caregivers. Furthermore, the Indicator-based glasses are used to show the guidance orders given by remotely caregivers. The web server part is transfer station between Android phone and OldBirds part.
Google Cloud Messaging service has already been integrated into this system so that caregivers can directly give guidance orders to senior citizens about when and where to go.
For future work I suggest, from the hardware perspective, to connect Pupil headset’s world camera and eye camera together by a USB hub. Furthermore, I recommend to combine Pupil headset and Indicator-based glasses together to remove the need for Bluetooth connection.
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Higashino, Satoru. "Study on signal processing and coding techniques for high density optical information storage channels." 京都大学 (Kyoto University), 2006. http://hdl.handle.net/2433/135949.
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Melder, Karl Henry. "PC-Gipsy:a usable PC-based image processing system." Master's thesis, Virginia Tech, 1990. http://hdl.handle.net/10919/40772.
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