Dissertations / Theses on the topic 'Photon management'
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ANGELINI, ANGELO. "Photon Management on a Photonic Crystal Platform." Doctoral thesis, Politecnico di Torino, 2015. http://hdl.handle.net/11583/2611159.
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A multilayered dielectric structure, namely a one dimensional photonic crystal (1DPC), is proposed as a suitable platform for photon management, due to the low absorption of the dielectric materials. When properly designed, a 1DPC can sustain surface electromagnetic modes called Bloch Surface Waves (BSWs). In this PhD Thesis it is shown how light coupled to BSW can be focused or guided by means of ultrathin polymeric refractive structures directly patterned on the surface. Moreover, by patterning the surface with surface relief gratings, far-field radiation can be efficiently coupled to the surface modes, thus providing an enhanced electromagnetic field at the truncation interface of the 1DPC. By shaping the grating in a circular symmetry, light can be in-plane focused into a sub-wavelength spot. The same structure can be used to re-shape the radiation pattern of dipolar emitters. It is shown that an emitter lying on the surface of the 1DPC couples to the photonic structure and the fluorescence radiated couple with the surface modes. The so called BSW-coupled fluorescence propagates along the surface with low losses and a well-defined wavevector. By means of surface diffraction gratings properly designed, fluorescence can be extracted along any direction, thus improving the fluorescence collection with no need of high numerical aperture optics or critical alignements. A novel method for evaluating the enhancement gained with such photonic structures on the extraction efficiency is proposed. Such method is capable of providing at the same time spatial resolution, angular resolution and spectral resolution. A biosensing experiment to detect small amounts of labeled proteins is provided, in order to show the sensing capabilities of the photonic structure.
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Hassan, Safaa. "Optical Property Study of 2D Graded Photonic Super-Crystals for Photon Management." Thesis, University of North Texas, 2020. https://digital.library.unt.edu/ark:/67531/metadc1703318/.
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In this dissertation, we study the optical property of 2D graded photonic super-crystals (GPSCs) for photon management. We focused primarily on manipulation and control of light by using the newly discovered GPSCs which present great opportunity for electromagnetic wave control in photonic devices. The GPSC has been used to explore the superior capability of improving the light extraction efficiency of OLEDs. The enhancement of extraction efficiency has been explained in term of destructive interference of surface plasmon resonance and out-coupling of surface plasmon through phase matching provided by GPSC and verified by e-field intensity distributions. A large light extraction efficiency up to 75% into glass substrate has been predicted through simulation. We also study the light trapping enhancement in GPSCs. Broadband, wide incident angle, and polarization independent light trapping enhancement is achieved in silicon solar cells patterned with the GPSCs. In addition, novel 2D GPSCs were fabricated using holographic lithography through the interference lithography by two sets of multiple beams arranged in a cone geometry using a spatial light modulator (SLM). Finally, we also report a fabrication of GPSCs with a super-cell size of 12a×12a by using e-beam lithography. Diffraction pattern from GPSCs reveals unique diffraction properties. In an application aspect, light emitting diode arrays can be replaced by a single light emitting diode shinning onto the diffraction pattern for a uniform fluorescence.
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Hu, Lu. "Photon management in thermal and solar photovoltaics." Thesis, Massachusetts Institute of Technology, 2008. http://hdl.handle.net/1721.1/46496.
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Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2008.Includes bibliographical references (p. 150-161).
Photovoltaics is a technology that directly converts photon energy into electrical energy. Depending on the photon source, photovoltaic systems can be categorized into two groups: solar photovoltaics (PV) and thermophotovoltaics (TPV). In solar photovoltaic systems, the photon source is the sun, whereas in thermophotovoltaic systems the photons are from artificially designed thermal emitters that operate at a lower temperature. The differences in the photon sources lead to different research emphases on the two photovoltaic systems in this work. This thesis investigates ways to control photon emission and absorption for solar energy and TPV applications. Several topics are discussed, including photon transport in multilayer structures, measurement of near-field thermal radiation, optical absorption in silicon nanowire structures, surface-plasmon enhanced near-bandgap optical absorption in silicon, and selective absorber surface for solar thermal applications. For thermophotovoltaic systems, the work is focused on thermal emission and photon transport. The study of photon transport in multilayer structures is presented. Results based on wave-optics and ray tracing methods are compared. The analysis shows that for structures contain a large number of layers, the coherence length of the emitting source is no longer a valid criterion to indicate whether ray tracing method is valid. Instead, wave inference effects always play a role. The effects of photon localization are also discussed. Surface-mode enhanced near-field thermal radiation is explored in this work as an effective way to tailor the thermal emission for TPV systems. Calculations based on fluctuation-dissipation theorem and Maxwell's equations are presented to study radiative heat transfer between two closely-spaced glass plates. The theoretical analysis shows that the radiative heat transfer between closely-spaced glass plates is enhanced by surface phonon polaritions and the flux can exceed the far-field upper-limit imposed by Planck's law of blackbody radiation.
(cont.) An experimental system was built to test near-field radiative heat transfer between two parallel glass plates, and the experimental results show good agreement with the theoretical predictions. For solar photovoltaics, the emphasis in this work is on improving optical absorption in silicon-based cells. Two nanostructures, silicon nanowire arrays and silicon embedded with small silver particles, have been analyzed as potential candidates for solar energy harvesting. The study on silicon nanowire structures reveals that nanowires have desirable antireflection characteristics. Several parameters, such as the length and diameter of the nanowires as well as the spacing between the wires, have been studied to provide the basis for the optimization of nanowire based solar cells. The study shows that nanowire structures have low reflectance over a broad spectrum and can absorb shortwavelength photons efficiently. However, the analysis also indicates that silicon nanowire is not efficient in absorbing long-wavelength photons. Longer wires in comparison to the thickness of dense films are generally required to compensate low absorption of the near-bandgap photons. The analysis of surface-plasmon assisted photon absorption is presented to address the problem of inadequate absorption of near-bandgap photons in silicon. Instead of increasing the optical path of photons for more absorption, surface plasmons are explored to enhance the local electromagnetic field and thus the optical absorption. An extended Mie scattering formulation is used to calculate the optical absorption around spherical silver particles embedded in silicon. It is found that local field enhancement by surface plasmon can lead to 50 times more absorption near the bandgap of silicon. An analytical model is developed to study the concentration effects of the surface plasmon field. It is shown that the net absorption gain reaches maximum when the spherical shell surrounding the particle has an outer diameter of 1.26 times of the particle diameter. The absorption loss in the metallic sphere, however, is a main obstacle to overcome.
(cont.) Finally, a different approach of solar energy utilization is discussed in this work. Selective absorber surfaces are studied for solar thermal energy harvesting. The surfaces consist of subwavelength periodic metallic structures. Finite-Difference-Time-Domain (FDTD) analysis is conducted on the metallic structures. The effects of lattice spacing and structure thickness are presented. The numerical simulation indicates that the metallic structures have good spectral selectivity: high absorptance in visible range and low emittance in infrared. Fabrication of the selective absorber surface is attempted. Preliminary experimental results are given in this work. As a proof of concept, nickel is plated in porous anodic aluminum. The resultant structure shows good spectral selectivity which is not found in bulk nickel or aluminum.
by Lu Hu.
Ph.D.
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ELSEHRAWY, FARID KHALED MOHAMED FARID. "Photon Management for Thin-Film Quantum Dot Solar Cells." Doctoral thesis, Politecnico di Torino, 2020. http://hdl.handle.net/11583/2843974.
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Fahr, Stephan [Verfasser], Falk Akademischer Betreuer] Lederer, Bernd [Akademischer Betreuer] [Rech, and Dietmar [Akademischer Betreuer] Knipp. "Photon-Management in Dünnschicht-Solarzellen / Stephan Fahr. Gutachter: Falk Lederer ; Bernd Rech ; Dietmar Knipp." Jena : Thüringer Universitäts- und Landesbibliothek Jena, 2012. http://d-nb.info/1019969660/34.
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ZAFFALON, MATTEO LUCA. "Advanced Spectroscopic Investigations of Colloidal Semiconductor Nanostructures for Photon Management and Radiation Detection Schemes." Doctoral thesis, Università degli Studi di Milano-Bicocca, 2022. http://hdl.handle.net/10281/366215.
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Le mie attività di ricerca hanno indagato i meccanismi di ricombinazione eccitonici in nanocristalli semiconduttori colloidali (NC), promuovendo lo sviluppo di nuovi paradigmi per la manipolazione delle proprietà ottiche e di scintillazione. Grazie all'ampia gamma di tecniche spettroscopiche e alle preziose collaborazioni intraprese, le mie conclusioni sono state pubblicate in prestigiose riviste scientifiche, contribuendo al progresso della comunità di scienziati dei nanomateriali. La mia ricerca ha trattato principalmente due temi di attuale rilevanza tecnologica: i) l'origine della fotoluminescenza in NC di calcogenuri ternari I-III-VI2 Cd-free come CuInS2 e AgInS2 ii) l'impiego di nanostrutture di perovskiti in schemi di rivelazione e/o conversione in energia di radiazione ionizzante.
Nello specifico, l’uso di tecniche spettroscopiche complementari in regime di temperatura controllata ha validato la presenza di sottolivelli intrinseci, con diversa parità, nella banda di valenza di NC stechiometrici di CuInS2 responsabili delle proprietà ottiche di questa classe di NC. I miei risultati, supportati da simulazioni di propagazione Monte Carlo, hanno portato alla fabbricazione di un concentratore solare luminescente - con efficienza record - basato su NC di CuInS2 con taglia ottimale. Lo studio è stato quindi esteso a NC di AgInS2, un materiale meno studiato ad oggi, ma molto promettente per applicazioni di bioimaging grazie all’assenza di elementi tossici.
Quindi, ho investigato la rivelazione di radiazione ionizzante attraverso nanostrutture ad alto numero atomico come le perovskiti a base di alogenuri di piombo (LHP), ed in particolare il CsPbBr3. Attraverso lo studio dettagliato delle proprietà di foto- e radio-luminescenza, ho evidenziato gli effetti dell’interazione tra eccitone di bordo banda e stati di difetto shallow/deep in nanostrutture di CsPbBr3 con diversa dimensionalità. Questo studio fondamentale ha offerto una piattaforma per sviluppare nuove strategie sintetiche atte a passivare i siti di intrappolamento sulle superfici degli NC che hanno portato ad un incremento di efficienza di scintillazione del 500%. La stabilità dei NC di CsPbBr3 è stata infine verificata in termini di resistenza alla radiazione gammma fino a dosi estreme di 1 MGy. Inoltre, per estendere la loro applicazione alla radiation detection con dispositivi a guida d’onda, ho studiato la sensibilizzazione di un colorante organico accoppiato a NC di CsPbBr3, realizzando il primo esempio di scintillatore plastico con ampio Stokes-shift e luminescenza veloce basato su LHP.
Per superare i limiti imposti dalla presenza di Pb nelle LHP, ho infine esplorato le proprietà ottiche e di scintillazione di nuove classi emergenti di perovskiti doppie green. Le informazioni raccolte incoraggiano il proseguimento di questa linea di ricerca indicando la passivazione superficiale come strategia più promettente per raggiungere prestazioni analoghe alle controparti a base di Pb.During my PhD I investigated excitonic recombination mechanisms in colloidal semiconductor nanocrystals (NCs), promoting the development of new paradigms for the manipulation of optical and scintillation properties. Thanks to the wide range of spectroscopic techniques and the valuable collaborations undertaken, my conclusions have been published in prestigious scientific journals, contributing to the advancement of the community of nanomaterials scientists. My research mainly dealt with two topics of current technological importance: i) the origin of photoluminescence in NC of Cd-free ternary I-III-VI2 chalcogenides such as CuInS2 and AgInS2 ii) the use of perovskite nanostructures in detection schemes and/or energy conversion of ionizing radiation. Specifically, the use of complementary spectroscopic techniques in a controlled temperature regime has validated the presence of intrinsic sublevels, with different parity, in the valence band of the stoichiometric CuInS2 NCs responsible for the optical properties of this class of NC. My results, supported by Monte Carlo ray-tracing simulations, led to the fabrication of a luminescent solar concentrator - with record efficiency - based on CuInS2 NCs with optimal size. The study was then extended to AgInS2 NCs, a less investigates material so far, but very promising for bioimaging applications thanks to the absence of toxic elements. Then, I investigated the detection of ionizing radiation through high atomic number nanostructures such as lead halide perovskites (LHP), and in particular CsPbBr3. Through the detailed study of photo- and radio-luminescence properties, I highlighted the effects of the interaction between band edge exciton and shallow/deep defect states in CsPbBr3 nanostructures with different dimensionality. This fundamental study offered a platform to develop novel synthetic strategies to passivate trap sites on NC surfaces that led to a 500% enhancement of scintillation yield. The stability of CsPbBr3 NCs was finally verified in terms of radiation hardness, up to extreme gamma doses of 1 MGy. Furthermore, to extend their application to radiation detection with waveguiding devices, I studied the sensitization of an organic dye coupled to CsPbBr3 NCs, creating the first example of a plastic scintillator with wide Stokes-shift and fast luminescence based on LHP. To overcome the limitations imposed by the presence of Pb in LHPs, I finally explored the optical and scintillation properties of new emerging classes of green double perovskites. The information gathered encourages the continuation of this line of research, indicating surface passivation as the most promising strategy for achieving performance similar to the Pb-based counterparts.
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Sundaresan, Sasi Sekaran. "ATOMISTIC MODELING OF PHONON BANDSTRUCTURE AND TRANSPORT FOR OPTIMAL THERMAL MANAGEMENT IN NANOSCALE DEVICES." OpenSIUC, 2014. https://opensiuc.lib.siu.edu/dissertations/854.
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Monte Carlo based statistical approach to solve Boltzmann Transport Equation (BTE) has become a norm to investigate heat transport in semiconductors at sub-micron regime, owing mainly to its ability to characterize realistically sized device geometries qualitatively. One of the primary issues with this technique is that the approach predominantly uses empirically fitted phonon dispersion relations as input to determine the properties of phonons so as to predict the thermal conductivity of specified material geometry. The empirically fitted dispersion relations assume harmonic approximation thereby failing to account for thermal expansion, interaction of lattice waves, effect of strain on spring stiffness, and accurate phonon-phonon interaction. To circumvent this problem, in this work, a coupled molecular mechanics-Monte Carlo (MM-MC) platform has been developed and used to solve the phonon Boltzmann Transport Equation (BTE) for the calculation of thermal conductivity of several novel and emerging nanostructures. The use of the quasi-anharmonic MM approach (as implemented in the open source NEMO 3-D software toolkit) not only allows one to capture the true atomicity of the underlying lattice but also enables the simulation of realistically-sized structures containing millions of atoms. As compared to the approach using an empirically fitted phonon dispersion relation, here, a 17% increase in the thermal conductivity for a silicon nanowire due to the incorporation of atomistic corrections in the LA (longitudinal acoustic) branch alone has been reported. The atomistically derived thermal conductivity as calculated from the MM-MC framework is then used in the modular design and analysis of (i) a silicon nanowire based thermoelectric cooler (TEC) unit, and (ii) a GaN/InN based nanostructured light emitting device (LED). It is demonstrated that the use of empirically fitted phonon bandstructure parameters overestimates the temperature difference between the hot and the cold sides and the overall cooling efficiency of the system, thereby, demanding the use of the BTE derived thermal conductivity in the calculation of thermal conductivity. In case of the light-emitting device, the microscopically derived material parameters, as compared to their bulk and fitted counterparts, yielded ~3% correction (increase) in optical efficiency. A non-deterministic approach adopted in this work, therefore, provides satisfactory results in what concerns phonons transport in both ballistic and diffusive regimes to understand and/predict the heat transport phenomena in nanostructures.
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Brady, Benjamin Arthur. "Automation in digital photo management." [Ames, Iowa : Iowa State University], 2007.
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Paniagua, Laconich Eduardo Javier. "Event-centric management of personal photos." Doctoral thesis, Università degli studi di Trento, 2015. https://hdl.handle.net/11572/368583.
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Since the last decade we have been observing a tremendous growth in the size of personal photo collections. For this reason, and due to the lack of proper automatic classification and annotation in standard album-centric photo software, users find it increasingly difficult to organise and make use of their photos. Although automatic annotation of media content can work to achieve more sophisticated multimedia classification and retrieval if its used in combination with rich knowledge representations, it still requires the availability of well-annotated training sets to produce the type of higher-level descriptions that would be of interest to casual users. Thus, the applicability of this approach is highly unlikely in the broad domain of personal photography. Recent developments in the media industry show an interest towards the organisation and structuring of media collections using an event-centric metaphor. This event-centric approach is inspired by strong research in psychology on how our autobiographical memory works to organise, recollect and share our life experiences. While this metaphor is backed by some early user studies, these were led before the large adoption of social media sharing services and there has been little recent research on how users actually use events digitally to organise and share their media. In this work we first present an updated study on what users are doing with their photos in current online platforms to support the suitability of an event-centric approach. Next, we introduce a simple framework for event-centric personal photo management focused on temporal and spatial aspects and through it we describe our techniques for automatic photo organisation and sharing. Finally, we propose a platform for personal photo management that makes use of these automatic techniques and present an evaluation of a prototypical implementation.
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Paniagua, Laconich Eduardo Javier. "Event-centric management of personal photos." Doctoral thesis, University of Trento, 2015. http://eprints-phd.biblio.unitn.it/1537/1/paniagua-phd-thesis.pdf.
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Since the last decade we have been observing a tremendous growth in the size of personal photo collections. For this reason, and due to the lack of proper automatic classification and annotation in standard album-centric photo software, users find it increasingly difficult to organise and make use of their photos. Although automatic annotation of media content can work to achieve more sophisticated multimedia classification and retrieval if its used in combination with rich knowledge representations, it still requires the availability of well-annotated training sets to produce the type of higher-level descriptions that would be of interest to casual users. Thus, the applicability of this approach is highly unlikely in the broad domain of personal photography. Recent developments in the media industry show an interest towards the organisation and structuring of media collections using an event-centric metaphor. This event-centric approach is inspired by strong research in psychology on how our autobiographical memory works to organise, recollect and share our life experiences. While this metaphor is backed by some early user studies, these were led before the large adoption of social media sharing services and there has been little recent research on how users actually use events digitally to organise and share their media. In this work we first present an updated study on what users are doing with their photos in current online platforms to support the suitability of an event-centric approach. Next, we introduce a simple framework for event-centric personal photo management focused on temporal and spatial aspects and through it we describe our techniques for automatic photo organisation and sharing. Finally, we propose a platform for personal photo management that makes use of these automatic techniques and present an evaluation of a prototypical implementation.
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Ferreyra, Romualdo A. "Electron – phonon interaction in multiple channel GaN based HFETs: Heat management optimization." VCU Scholars Compass, 2014. http://scholarscompass.vcu.edu/etd/3636.
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New power applications for managing increasingly higher power levels require that more heat be removed from the power transistor channel. Conventional treatments for heat dissipation do not take into account the conversion of excess electron energy into longitudinal optical (LO) phonons, whose associated heat is stored in the channel unless such LO phonons decay into longitudinal acoustic (LA) phonons via a Ridley path. A two dimensional electron gas (2DEG) density of ~5×1012cm-2 in the channel results in a strong plasmon–LO phonon coupling (resonance) and a minimum LO phonon lifetime is experimentally observed, implying fast heat removal from the channel. Therefore, it is desirable to shift the resonance condition to higher 2DEG densities, and thereby higher power levels. The more convenient way to attain the latter is by widening the 2DEG density profile via heterostructure engineering, i.e. by using multiple channel heterostructures. A single channel heterostructure (GaN/AlN/AlGaN), a basic heterostructure used to obtain a 2DEG, exhibits a resonance condition at low 2DEG densities (~0.65×1012 cm-2). Successful widening of the 2DEG density xv profile was predicted by simulation results for two types of multiple (Al)GaN channel heterostructures, i.e. coupled channel GaN/AlN/GaN/AlN/AlGaN and dual channel GaN/AlGaN/AlN/AlGaN. Because of a reduction of carrier confinement, it is experimentally observed that control of the channel is moderate in the case of dual channel heterostructures. On the other hand, carrier confinement provides a better control of the channel in coupled channel heterostructures. Furthermore, unlike in a dual channel heterostructure, alloy scattering does not affect carrier transport properties, which results in a higher cut-off frequency. It was found experimentally that the coupled channel heterostructure successfully reaches resonance condition at a 2DEG density that is 23% higher than in a single channel heterostructure. Multiple channel heterostructures therefore provide a convenient way to shift the plasmon-LO phonon resonance to higher 2DEG densities. However, in our grown heterostructures, high power levels under optimal channel working conditions and minimum heat accumulation, all desirable benefits for the development of high power transistors, were only observed in coupled channel heterostructures.
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Elliott, Brendan David. "Hierarchical and Semantic Data Management and Querying for Patient Records and Personal Photos." Case Western Reserve University School of Graduate Studies / OhioLINK, 2009. http://rave.ohiolink.edu/etdc/view?acc_num=case1226303040.
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Cohen, Jonathan Morris. "Stakeholder attitudes toward forest management in southern Illinois : an application of photo-evaluation surveys /." Available to subscribers only, 2008. http://proquest.umi.com/pqdweb?did=1594480701&sid=13&Fmt=2&clientId=1509&RQT=309&VName=PQD.
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Samadian, Parya. "Photonic Integrated Circuits Challenges & Solutions: Homogenization, Polarization Management and Coupling." Thesis, Université d'Ottawa / University of Ottawa, 2015. http://hdl.handle.net/10393/33352.
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In recent years much effort has been carried out to make integrated photonics a widespread technology to be exploited in current optical communication industry. It is hoped
by substituting microelectronics by photonic chips and keeping the light carried by
optical fibers in light domain for further processing, the cost and speed of
communications will be vastly improved. Although this transition is challenging in
various aspects, here in this thesis some of these issues are discussed and addressed.
In this thesis firstly the limitations of current simulation tools for analysis of wide range
of photonic devices is pointed out. Structures based on photonic crystals are taken into
consideration at this point which because of finely detailed structures have shown to be
challenging to be analyzed by conventional tools. In this regard three different common
structures based on photonic crystals in both resonant and non-resonant regimes have
been considered: lamellar gratings, metamaterials for Lüneburg lens and Bragg gratings
in a LC-DFB laser. For each structure, an analytical method or homogenization approach
is proposed which is claimed to be faster for analysis of such components than numerical
methods. Comparisons of the results with conventional numerical methods prove
accuracies of each approach.
Furthermore, fiber-to-chip coupling and polarization management are discussed as other
important issues in the field of integrated photonics. Concerning polarization
management, stepped waveguide approach will be introduced as the most promising
approach for SOI and III-V substrates and designs based on this structure reported in
literature are reproduced and inaccuracies are pointed out and corrected accordingly. Also
regarding fiber-to-chip coupling, a critical appraisal of the most recent proposed
structures for edge coupling will be offered and the results will be reproduced by
simulation tools. At the end, based on detailed comparisons, the most encouraging
approach with low insertion loss and easy fabrication steps is introduced and novel
platform for easy butt coupling single mode fibers to the coupler structure is proposed.
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Shane, Ryan S. "Riparian photo-monitoring : detecting change in selected lotic riparian system attributes /." abstract and full text PDF (UNR users only), 2008. http://0-gateway.proquest.com.innopac.library.unr.edu/openurl?url_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&res_dat=xri:pqdiss&rft_dat=xri:pqdiss:1455659.
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Thesis (M.S.)--University of Nevada, Reno, 2008."May, 2008." CD-ROM contains Adobe Acrobat copy of thesis, power-point presentation entitled: Effectiveness and reliability of photo-pair interpretation, and photographs taken during the study. Includes bibliographical references. Library also has microfilm. Ann Arbor, Mich. : ProQuest Information and Learning Company, [2009]. 1 microfilm reel ; 35 mm. Online version available on the World Wide Web.
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Kaul, Pankaj B. "Thermal Transport in Tin-Capped Vertically Aligned Carbon Nanotube Composites for Thermal Energy Management." Case Western Reserve University School of Graduate Studies / OhioLINK, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=case1383515941.
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Banasik, Robert Michael. "Marketing Strategies Used by Specialty Photo Retailers to Grow Revenues." ScholarWorks, 2016. https://scholarworks.waldenu.edu/dissertations/2468.
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The advent of digital cameras, including those in smartphones, has caused an upheaval in
the photo industry that led to the bankruptcy of Kodak and the closure of most
independent photo stores. The purpose of this multiple case study was to explore
marketing strategies that specialty photo retailers in the United States have used to grow
revenues after the shift to digital imaging technologies. The conceptual framework of this
study was Rogers's diffusion of innovations model specifying typical movement of
information through communications channels in a social system over time. Data sources
included semistructured interviews with 5 photo retailers, photos of facilities and pointof-
sales displays, website pages, and social media. Data were analyzed using inductive
coding of phrases and words from interviews, followed by identification of common
themes. Additional data gleaned from participants' displays, websites, and other
documents supported interpretations of themes through methodological triangulation.
Strategies that the 5 participating retailers used to grow revenues were manifest in 3
major themes: adoption of new technologies, market segmentation, and marketing
communications. Study participants described various strategies to acquire customers
including the use of technology (e.g., enterprise-level management systems), defining
market segments underserved by competitors, and customizing marketing
communications for specific targeted segments. A viable retail channel can produce
social change by providing sources of information on new products that can enhance
consumers' lives and create economic growth via new jobs.
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Yuen, Siu Yu. "Routing and time-slot assignment algorithms and connection management in photonic circuit switched networks /." View abstract or full-text, 2005. http://library.ust.hk/cgi/db/thesis.pl?ELEC%202005%20YUEN.
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Curtin, Benjamin Michael. "Photonic crystal back-reflectors for light management and enhanced absorption in a-Si:H solar cells." [Ames, Iowa : Iowa State University], 2009. 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:1468075.
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Toccaceli, Cecilia. "Geo Photo Routing: raccomandazione dell'itinerario di viaggio utilizzando i geotag dei siti di condivisione foto." Bachelor's thesis, Alma Mater Studiorum - Università di Bologna, 2017. http://amslaurea.unibo.it/13766/.
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I geotags indicano dove sono state scattate le fotografie e vengono
automaticamente acquisiti dai dispositivi mobili o, in alternativa,
possono essere specificati dall’utente. I geotags sono metadati potenti per introdurre informazioni spaziali in applicazioni Web.
Il presente elaborato si focalizza sulla descrizione dello sviluppo di un’applicazione web per suggerire un itinerario di viaggio, mediante l’utilizzo di immagini geotaggate nei servizi di condivisione foto, in particolare Flickr.
Le geolocazioni fotografate possono essere buone raccomandazioni per trovare luoghi interessanti, in quanto il caricamento di una fotografia sul social network può essere considerato come un voto positivo e, di conseguenza, come una località che vale la pena visitare. L’utente, attraverso una semplice interfaccia grafica, deve inserire il punto di partenza, quello di arrivo e un raggio d’azione, dopodiché la piattaforma si occuperà di calcolare e visualizzare
sulla mappa sia il percorso più breve, quello di base calcolato da Google Maps, sia il percorso con maggiori punti d’attrazione.
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Sjödin, Erik. "Pixgis : An Application for Map-centric Management of Photographs with Embedded Spatial Metadata." Thesis, Linköping University, Department of Science and Technology, 2006. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-8002.
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This thesis presents Pixgis; a novel application for map-centric management of photographs. In short Pixgis is an interactive environment in which photographs may be discovered, viewed and managed through maps. With Pixgis finding photographs from a specific location or of a particular structure is as easy as finding the location or structure on a map. As Pixgis simultaneously displays maps, photographs and spatial metadata it also enables users to analyze photographs in new manners. This thesis work illustrates the benefits of applications for map-centric management of photographs, exposes the problems one faces when implementing such applications and presents novel solutions to many of these problems. The thesis also elaborates on spatial metadata and methods for acquisition of photographs with embedded spatial metadata.
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Bonezzi, Mirko. "GEO PHOTO ROUTING: Progettazione ed implementazione di una applicazione per routing pedonale." Bachelor's thesis, Alma Mater Studiorum - Università di Bologna, 2017. http://amslaurea.unibo.it/14427/.
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La maggior parte dei servizi di routing, sia web che mobile, quando fornisce un percorso per arrivare ad una determinata destinazione, suggerisce spesso il percorso più breve. L’obbiettivo di questo progetto di tesi è dimostrare che è possibile creare un servizio di routing che non indichi solamente il percorso più breve tra 2 punti, ma anche quello più emotivamente piacevole, rilassante, che aumenti il benessere di chi lo percorre.
Per rendere ciò possibile, ci si è basati sull’utilizzo di foto geotaggate presenti su un sistema di archiviazione e condivisione foto online: Flickr. Si ipotizza che un luogo geografico in cui sono state scattate molte fotografie, sia allora un luogo piacevole da visitare o da cui transitare. Questa ipotesi fondamentale guida quindi alla creazione di un percorso secondario, più piacevole, che passi da determinati punti di interesse.
In questo elaborato viene descritta l’implementazione e la progettazione di una piattaforma che abbia l’obbiettivo di mettere a disposizione degli utenti il servizio di routing appena descritto. È stato utilizzato un server Apache sul quale alcuni script PHP si occupano di gestire le richieste del Client e calcolare, tramite un opportuno algoritmo, il percorso adatto alle loro richieste. Inoltre è stata sviluppata un’applicazione Android, Client-side, su cui l’utente può effettuare richieste e visualizzare percorsi.
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Turley, Helene. "Through the lens : using auto-driven photo-elicitation to capture the development of career aspirations of business management and fine art students." Thesis, University of Wolverhampton, 2018. http://hdl.handle.net/2436/621282.
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The uniqueness of this study is primarily in the application of a visual research methodology to generate knowledge and understanding in an area that is often associated with quantitative research. Careers and employment research typically focuses on statistical information which can provide general information but does not give an in-depth understanding of the area under study. Visual research can give an in-depth understanding; in addition to giving access to a different kind of knowledge, supported by Harper (2002) who proposes “that images can evoke deeper elements of human consciousness than words alone.” I explore the various ways in which students perceive and develop different career aspiration including what motivates and what might inhibit students’ development of their career aspirations. This understanding will enhance my professional practice and encourage the Careers and Employment department within the University to adapt their service and give students the relevant tools and information to prepare them for employment. A visual research methodology is utilised as this fits comfortably with my background in art and gives the in-depth knowledge I require for my research (see Clark-Ibáñez, 2004; Collier (1957); Collier and Collier, 1986; Cousin, 2009; Guillemin and Drew, 2010; Harper, 2002; Harris and Guillemin, 2012 and O’Brien, 2013 for further information on the benefits of using a visual research methodology). Auto-driven photo-elicitation (ADPE) is used with six fine art and six business management students. These students often have less career direction and tend to struggle to secure graduate level positions (Swani, 2016); in addition, the two subject areas were chosen because they are a contrast in terms of how their curriculum is delivered. Using visual research to inform careers and employment is unique and through sharing my research and research experience I want to initiate a shift in how careers and employment research is approached in the future. In addition to the uniqueness of using a visual research methodology in careers and employment my findings indicate there are five orientations business management and fine art students’ use when developing their career aspirations: a strong sense of direction, intrinsic and extrinsic motivations, weak planning and dreams. This research discusses the five orientations and the factors that might contribute to a rich learning environment for career building. Subject and professional identity are discussed in relation to identity formation and career building. Four main sources of identity formation are identified: identity through being (transition from study to profession), identity through self-discovery, identity through belonging (concerning the informal and cultural aspects of community life), and identity through peripheral participation (activities that are akin to peripheral participation in a professional community). This research establishes there is a relationship between the development and building of identity and self-efficacy through belonging, professional experience and working alongside mentors when developing strategies to develop career aspirations.
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Hawkins, William Cory. "Evaluation of the data vortex photonic all-optical path interconnection network for next-generation supercomputers." Available online, Georgia Institute of Technology, 2006, 2006. http://etd.gatech.edu/theses/available/etd-12182006-155304/.
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Thesis (Ph. D.)--Electrical and Computer Engineering, Georgia Institute of Technology, 2007.Dr. Henry L. Owen III, Committee Member ; Dr. David Keezer, Committee Member ; Dr. D. Scott Wills, Committee Chair.
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Doyeux, Pierre. "Energy management at the quantum scale : from thermal machines to energy transport." Thesis, Montpellier, 2017. http://www.theses.fr/2017MONTS070/document.
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Cette thèse traite de la manipulation de l'énergie dans trois systèmes quantiques ouverts différents dans la limite de couplage faible système-environnement, et leurs dynamiques respectives sont décrites par une équation maîtresse quantique markovienne. Dans le premier chapitre, le calcul d'une telle équation est réalisé pour un système particulier, et diverses notions de thermodynamique quantique sont introduites. Pour le premier système physique, on analyse le transport d'énergie le long de chaînes atomiques (entre 2 et 7 atomes) soumises à un rayonnement de corps noir proche de la température ambiante. Il est montré que l'efficacité du transport peut atteindre des valeurs remarquables, surpassant 100% et atteignant jusqu'à 1400% dans certaines configurations. De plus, lorsque l'efficacité est amplifiée, la portée du transport est également considérablement augmentée. Le chapitre suivante traite aussi du transport d'énergie dans des chaînes atomiques. Le système quantique est placé à l'interface d'un isolant topologique photonique (ITP), qui supporte un plasmon polariton de surface (PPS) insensible à la réflexion. Le PPS se propage le long de la chaîne atomique et assiste le transport d'énergie. La comparaison est faite entre PPSs réciproque et unidirectionnel en termes d'efficacité du transport, et il est démontré que ce dernier produit une meilleure efficacité, de plus d'un ordre de grandeur. De surcroît, divers aspects pratiques dus aux propriétés des ITPs sont mis en avant, notamment la robustesse du transport d'énergie en présence de défauts sur le parcours du PPS. Enfin, un système quantique immergé dans un champ électromagnétique hors équilibre thermique est étudié. Il est composé d'un système à trois niveaux d'énergie, jouant le rôle de machine thermique quantique à absorption, ainsi que de N atomes à deux niveaux ("qubits") qui sont affectés par l'action de la machine. Il est montré que la machine est capable de délivrer des tâches thermiques d'intensité significative sur les qubits, y compris lorsque leur nombre augmente. De plus, il est mis en évidence qu'en raison d'interactions qubit-qubit, les tâches réalisées par la machine sont distribuées parmi l'ensemble du système des qubits en interaction, de sorte que dans certains cas, même les qubits complètement découplés de la machine subissent une modification de température considérable. Ce mécanisme de distribution des tâches est analysé à travers les corrélations entre différentes partitions du système quantique. Par ailleurs, le contrôle des tâches thermiques est également discutéThis thesis deals with energy management in open quantum systems. Three different systems are under study in the limit of weak system-environment coupling, and their dynamics is described by Markovian quantum master equations. In the first chapter, the complete derivation of such equation is performed in a specific case, and several notions of quantum thermodynamics are introduced. In the first system, energy transport is investigated along atomic chains (between 2 and 7 atoms) embedded in blackbody radiation around room temperature. It is shown that the transport efficiency can reach remarkable values, exceeding 100% and reaching 1400% in some configurations. Moreover, when the efficiency is amplified, the transport range is also considerably increased. The following chapter also deals with energy transport in atomic chains. The quantum system is located at the interface of a photonic topological insulator (PTI), supporting a unidirectional surface-plasmon-polariton (SPP) immune to backscattering. The SPP propagates along the chain and assists energy transport. Comparison is made between reciprocal and unidirectional SPPs in terms of transport efficiency, and it is shown that the latter can yield an efficiency larger by one order of magnitude. In addition, several practical aspects stemming from PTIs are highlighted, including the robustness of energy transport in the presence of defects on the SPP path. In the last chapter, a quantum system embedded in an out-of-thermal-equilibrium electromagnetic field is investigated. It is composed of a three-level atom playing the role of an absorption quantum thermal machine, as well as N two-level atoms ('qubits'), with N=1,...,6, which are the target bodies. It is demonstrated that the machine is able to perform significant thermal tasks on the qubits, even when their number is increased. Moreover, it is pointed out that due to qubit-qubit interactions, the tasks delivered by the machine are distributed throughout the system of interacting qubits, such that in some cases the temperature of the qubits which are completely decoupled from the machine can still be considerably affected by it. This task-distribution mechanism is investigated by means of the correlations between different subparts of the system. In addition, the tuning of thermal tasks is discussed
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Wolfe, Kimberly. "Flat Files: The Absence of Vernacular Photography in Museum Collections." VCU Scholars Compass, 2010. http://scholarscompass.vcu.edu/etd/163.
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This thesis will explore the causes and consequences of the absence of vernacular photography from museum collections. Through historical analysis of vernacular photography and a close interpretation of a contemporary family snapshot, I will argue that vernacular photographs are important objects of great cultural significance and poignant personal meaning. Photography has always defied categorization. It serves multiple functions and roles, is studied in a vast number of disciplines, and exists in a variety of institutions and collections. Furthermore, it is difficult to classify a single photograph. Vernacular photography thus poses a challenge to museum methods of sorting documents, artifacts, and art. Consequently the photographs that are most significant in everyday life are often missing from the museum setting or are misinterpreted and stripped of their meaning.
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Neenan, Johnathan. "Evaluation of Stream Bank Restoration to Improve Water Quality in a Semi-Arid Stream." DigitalCommons@USU, 2019. https://digitalcommons.usu.edu/etd/7687.
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Human watershed activities such as converting land cover to agriculture and livestock grazing have negatively impacted stream water quality worldwide. One such case is Utah’s Upper Sevier River where a loss of woody bank vegetation (reduced shading) and accelerated bank erosion (increased fine sediment inputs) has led to increased stream temperature and water turbidity. As a result, the state of Utah sought to improve water quality conditions using streambank restoration. While commonly recommended and performed, the effectiveness of this sort of restoration has rarely been quantified. Here, I evaluated a restored reach of the Upper Sevier River near Hatch, UT using continuous monitoring data and a historical photo analysis. As Utah wishes to continue performing this type of restoration in additional locations on the Upper Sevier River, I applied a simple sediment budget model to test its value in informing future streambank restoration decisions.
Continuous monitoring data at the upstream and downstream extent of restoration showed that both stream temperature and turbidity increased downstream along the restored reach. In addition, I found that stream temperature violated Utah’s cold-water stream threshold at both sites but did not violate thresholds for rainbow trout. Turbidity violated state and biological thresholds at both sites. I was unable to conclude whether the streambank restoration directly altered water quality because I lacked monitoring data before restoration occurred. Results of the historical aerial photo analysis showed that restoration practitioners were successful in reducing cut bank erosion. My use of SIAM as a simple sediment budget model proved insufficient due to poor data quality and quantity. Overall, streambank restoration was successful at reducing cut bank erosion, and I recommended monitoring future restoration before and after project completion, identifying and monitoring upstream sources of fine sediment, and pursuing more comprehensive sediment models to inform future streambank restoration.
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Reihammar, Emma. "Mönstersimulering av kamouflage : Framtagning av metodik för virtuell utvärdering av visuell maskeringsförmåga." Thesis, Uppsala universitet, Industriell teknik, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-430015.
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Saab Barracuda utvecklar och tillverkar avancerade kamouflagesystem för skydd mot upptäckt och identifiering genom signaturanpassning. Signaturanpassning är en grundläggande del av taktiska strategin för militära styrkor och uppnås genom att reducera kontrasten mot bakgrunden för ändamålsenliga våglängdsområden inom det elektromagnetiska spektrumet. I det visuella området reduceras signaturskillnader främst genom färger och mönster, vilket anpassas till målets taktiska miljö. För att kunna optimera kamouflage är det viktigt att kunna utvärdera och bedöma de olika inverkande egenskapernas effektivitet när det kommer till att reducera ett objekts signatur, vilket syftar på de egenskaper som karaktäriserar ett objekt och särskiljer den från dess omgivning. Konventionellt sett görs detta genom studier i fältmiljö. Metoden ger en verklighetsförankring men kombinationen av olika objekttyper, terränger, taktiska avstånd och miljörelaterade parametrar gör utvärderingsmomentet snabbt till en tids- och resurskrävande process. Syftet med arbetet är att ta fram en metod för virtuell utvärdering av kamouflage visuella maskeringsförmåga som bidrar till att göra framtagningen mer tids- och resurseffektiv. Tillvägagångssättet består av dokumentstudier i kombination med simuleringsstudier. Metodiken efterföljer Design research methodology (DRM) som syftar till att ge en förståelse för processer samt utveckla stöd för att förbättra eller optimera dem. Resultatet från studien bildar sammantaget med en metod för att virtuellt kunna utvärdera mönster. En 3D modell av kamouflagenätet har tagits fram och en metod för insamling av 2D bilder av terränger beskrivs. Metoden möjliggör utvärdering av maskeringsförmågan hos kamouflage på olika observationsavstånd och betraktningsvinklar där byte av mönster och bakgrunder med enkelhet kan utföras. Soldata kan anpassas till bilden för att erhålla ett visuellt, realistiskt resultat. Utvärdering görs i programmet Adobe Dimension och modellen har skapats i Autodesk 3ds Max. Inställningar för att efterlikna det fysiska nätets mekaniska samt spektrala egenskaper approximativt togs fram genom att subjektivt jämföra den optiska konstrasten mellan simulering och foto. Resultatet presenterades för forskning- och utvecklingsavdelningen på Saab Barracuda med 14 personer närvarande.Saab Barracuda develops and manufactures advanced camouflage systems for protection against detection and identification through signature management. Signature management is a fundamental part of the tactical strategy of military forces and is achieved by reducing the contrast against the background of appropriate wavelength ranges within the electromagnetic spectrum. In the visual field, signature differences are mainly reduced by colors and patterns, which are adapted to the target's tactical environment. In order to enable optimization of camouflage, it is important to be able to evaluate the effectiveness of the various influencing properties when it comes to reducing an object's signature, which further refers to the characteristics of an object that distinguish it from its surroundings. Nowadays, this is mainly done through field studies. The method provides an accurate picture of the dynamic range that occurs in reality, but the combination of different types of objects, terrains, tactical distances and environmental-related parameters quickly makes the evaluation process a time and resource consuming process. The purpose of this thesis is to develop a method for virtual evaluation of a camouflage visual signature in order to make the development process more time and resource efficient. The approach consists of document studies in combination with simulation studies. The methodology used to achieve the method follows Design research methodology (DRM), which aims to provide an understanding of processes and develop support to improve or optimize them. The results of the study together form a workflow for virtual evaluation of different patterns. A 3D model of the camouflage net has been developed and a method for collecting 2D images of terrains is described. The method enables evaluation at different observation distances and viewing angles where patterns and backgrounds easily can be changed. Sun and weather data can be adapted to the image to visually obtain a realistic result. Evaluation is done in Adobe Dimension and the model has been created in Autodesk 3ds max. The settings used to mimic the mechanical and spectral properties of the physical camouflage were approximated by subjectively comparing the optical contrast between simulation and photo. The result was presented for the research and development team on Saab Barracuda with 14 persons being present.
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Leblois, Richard. "Solar Impulse - Around the World in a Solar Airplane." Universitätsbibliothek Chemnitz, 2012. http://nbn-resolving.de/urn:nbn:de:bsz:ch1-qucosa-86938.
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- Einführung in das Projekt Solar Impulse (Entstehung, Herausforderung, Errungenschaften)
- Beschreibung der eingesetzten Software Tools zur Entwicklung des Flugzeuges
- Fallbeispiele für den Einsatz von Mathcad
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Esmeier, Chelsea Marie. "Impact of Female Adolescents’ Motivations for Managing Online Photographic Self-Presentations on Their Social and Psychological Wellbeing." Xavier University / OhioLINK, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=xavier1554114196609514.
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Belletti, Barbara. "Analyse régionale de la structure et de la dynamique biogéomorphologiques des rivières en tresses du bassin du Rhône." Thesis, Lyon 3, 2012. http://www.theses.fr/2012LYO30099.
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Le paysage des rivières en tresses est constitué d’une riche mosaïque d’habitats diversifiés, déterminée par un ensemble de facteurs biophysiques qui interagissent à différentes échelles spatiales et temporelles.A partir d’une sélection de 53 tronçons en tresses, nous avons réalisé une analyse comparative à l’échelle régionale du bassin du Rhône et en fonction de plusieurs échelles temporelles, en mobilisant les techniques de télédétection.Premièrement, nous avons étudié la variabilité de la structure des habitats aquatiques et du patron des chenaux. Nous montrons que le patron de tressage et des habitats aquatiques n’est pas uniquement lié au débit, mais aussi aux conditions locales liées aux apports sédimentaires et à la présence de la nappe phréatique.Deuxièmement, nous avons abordé une approche diachronique afin de comprendre l’évolution à moyen terme du paysage fluvial de ces tronçons, depuis la moitié du siècle dernier. Les résultats montrent que toutes les tresses du bassin rhodanien ne sont pas déliquescentes et que certains tronçons sont encore très actifs. Cela dépend d’un ensemble de facteurs : la position géographique du tronçon, son évolution à court terme liée aux épisodes de crues et l’histoire des conditions anthropiques environnantes.Enfin nous avons analysé les trajectoires évolutives suivies par un sous-ensemble de 12 sites, analysés à une échelle temporelle plus fine (5 observations par site sur 50 ans). Nous observons que les tronçons suivent des trajectoires différentes, en fonction des conditions hydrologiques observables à un moment donnée (ex. crues), de la position géographique du tronçon et du contexte anthropique. De plus, certaines conditions locales (topographie et humidité relative) semblent aussi nécessaire à la compréhension du patron biogéomorphologique des tronçons étudiés.A partir de ces résultats des éléments de perspectives pour une gestion intégrée des rivières en tresses du district rhodanien sont proposésThe landscape of the braided rivers is characterised by a rich and diversified mosaic of habitats. The variability of the braided riverscape depends upon the combination of bio-physical factors, which interact at the different spatial and temporal scales.We did a comparative analysis at the regional scale of 53 braided reaches selected in the Rhône basin district. We used a remote sensing-based approach.At first, we analysed the aquatic habitat and the river channel pattern. We showed that the braiding and aquatic habitat patterns do not depend only on the flow regime but also on some local scale conditions, such us the sediment regime and the presence of the “near-floor” groundwater.Secondly, we moved on the overall riverscape corridor, and we applied a diachronic analysis comparing the present state of reaches with their state at the mid of the last century. The results show that not all studied braided reaches are narrower today compared to the 1950s and that some reaches are even wider. It is linked to a combination of several factors, such as the geographical position of a reach in its catchment and the short-term evolution ruled by recent large floods, as well as the history of the catchment linked to human settlements.Then we focused on the evolutionary trajectories followed by a sub-set of 12 braided reaches through time, and we increased the temporal resolution, for a total of five dates per reach. The results show that reaches follow different trajectories depending on: the hydrological conditions at a given period (e.g. floods), the geographical position of a reach at the regional scale and the anthropic context. Additionally, it seems that also local conditions (in terms of topography, sedimentation, and soil moisture), play an important role in determining the biogeomorphological pattern of the studied reaches.From these results, we discussed some perspectives for the braided river management in the Rhône basin district
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PESTANA, Rayner Carvalho. "Para a implanta??o da meritocracia na gest?o de carreira: implica??es dos contextos cultural, gerencial e pol?tico de uma empresa estatal federal brasileira." Universidade Federal Rural do Rio de Janeiro, 2015. https://tede.ufrrj.br/jspui/handle/jspui/1343.
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The transformation of the Brazilian Public Management, specifically about the adoption of modern tools for human resources, has been happening since the last century and the concern about the introduction of meritocracy in career management is still considered a recurring theme. An evidence of that is the guidance from management and control department of federal state-owned companies to adopt meritocracy in their career management systems. The organization studied here, although already have passed thirteen years of validity of its current jobs and salaries plan, seems not yet to have been able to establish career management policies based on meritocracy. Due to the problem presented, the main objective of this research focused on raising the implications of the organizational context of a Brazilian federal state-owned company, dependent on the Treasury, for the introduction of meritocracy in career management. An applied qualitative research was carried out, configured in the form of a single case study to map the features of the current cultural, managerial and political contexts and to interpret their implications in the adoption of meritocracy as an organizational value. The research subjects were purposefully selected, among managers and career employees, and interviewed based on a script and from a photograph (photo elicitation) to reveal the current context. The field data were subjected to an inductive hermeneutic analysis. Based on these results, it can be inferred that meritocracy in career management, understood as ?a set of criteria, adopted by an organization that has on individual performance, effort and results, the fundamental pillars for granting promotions and progressions to its employees in their own careers?, is not yet explicitly manifested in the studied company. It was perceived that the company is set as a political arena type and that the current alternative process of granting promotions and progressions has been working as a fundamental mechanism for the on going internal power dynamics. On the context found, some manager actions were proposed to contribute to the implementation of meritocracy in career management. It can be considered, as a contribution to the field, the opportunity for reflecting on the negative implications of the penetration of management values in human resources, regarding: uncritical transfer of tools from the private sector to the public one; defense of entrepreneurship discourse that considers the career management as sole responsibility of the professional; only financial and quantitative focus on performance evaluations; and probability of management tools not resulting in professional development but only in the control and exploitation of the individual. For future research it is suggested i.e.: to investigate what commitment means to the organizational members in order to connect it to the company's concepts raised in the study; to analyze meritocracy from the psychological contract breach viewpoint; and to expand this study to other public organizations dependent or not on the Treasury, to ascertain the implications of cultural and managerial traits and the power dynamics for the adoption of meritocracy in career management.
A transforma??o da Administra??o P?blica Brasileira, no que tange ? ado??o de ferramentas modernas de gest?o de pessoas, vem ocorrendo desde o s?culo passado e a preocupa??o com a meritocracia na gest?o de carreira se configura como um assunto ainda recorrente. Como prova disso, destacam-se as orienta??es do ?rg?o de gest?o e controle das empresas estatais federais para que elas adotem a meritocracia nos seus sistemas de gest?o de carreira. A organiza??o aqui estudada, embora passados treze anos de vig?ncia do atual plano de cargos e sal?rios, parece ainda n?o ter conseguido instituir pol?ticas de gest?o de carreira calcadas na meritocracia. Diante do problema apresentado, o objetivo principal desta pesquisa se concentrou em levantar as implica??es dos tra?os provenientes do contexto organizacional de uma estatal federal brasileira, dependente do Tesouro Nacional, para a implanta??o da meritocracia na gest?o de carreira. Realizou-se pesquisa aplicada de natureza qualitativa, configurada em forma de estudo de caso ?nico para mapear os tra?os do contexto cultural, gerencial e pol?tico vigentes e interpretar suas implica??es na ado??o da meritocracia como um valor organizacional. Os sujeitos da pesquisa foram selecionados pelo m?todo proposital, entre gerentes e empregados de carreira, e entrevistados mediante roteiro e a partir de uma fotografia (elicita??o fotogr?fica) que revelasse o contexto vigente na ?tica dos mesmos. Os dados de campo foram qualitativamente analisados de forma hermen?utico-indutiva. Com base nos resultados obtidos, conclui-se que a meritocracia na gest?o de carreira, entendida como ?o conjunto de crit?rios, adotado por uma organiza??o, que possui no desempenho, no esfor?o individual e nos resultados alcan?ados os pilares fundamentais para a concess?o de promo??es e progress?es dos empregados em suas respectivas carreiras?, n?o ?, ainda, praticada explicitamente na empresa estudada. Revelou-se que a empresa se configura como uma organiza??o do tipo arena pol?tica e que o vigente processo alternativo de concess?o de promo??es e progress?es tem funcionado como um mecanismo fundamental na din?mica interna de poder. Diante deste contexto, foram propostas a??es de forma a contribuir com a implanta??o da meritocracia na gest?o de carreira. Considera-se como contribui??o ? ?rea a oportunidade de reflex?o sobre as implica??es da penetra??o de valores do management na gest?o de pessoas, relativas a: transfer?ncia acr?tica de ferramentas do setor privado para o p?blico; defesa do discurso do empreendedorismo, pressupondo a gest?o de carreira como responsabilidade unicamente do profissional; perspectiva apenas financeira e quantitativa das avalia??es de desempenho; e probabilidade das ferramentas de gest?o n?o resultarem no desenvolvimento profissional, mas no controle e explora??o do indiv?duo. Para aprofundamento em futuras pesquisas, sugere-se, dentre outras a??es: investigar o conceito de comprometimento na organiza??o, conectando-o ?s concep??es da Empresa levantadas no estudo; analisar a meritocracia a partir da ?tica da quebra do contrato psicol?gico; e expandir a presente pesquisa a outras organiza??es p?blicas dependentes ou n?o do Tesouro, a fim de evidenciar as implica??es dos tra?os culturais e gerenciais e da din?mica de poder existentes na ado??o da meritocracia na gest?o de carreira.
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Fu, Po-Han, and 傅柏翰. "Photon Management Employing Photonic Crystal in InGaN Quantum Well Based Devices." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/60592543639443752414.
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碩士國立臺灣大學
光電工程學研究所
100
In this study, the schemes of enhancing the performances of indium gallium nitride (InGaN) based multiple quantum well (MQW) solar cells and light-emitting diodes (LEDs) are investigated. For the enhancement of conversion efficiencies of solar cells, SiO2 nano-honeycomb photonic crystals are fabricated on the devices. The nano-honeycombs are found to be effective in suppressing the undesired surface reflections over visible wavelengths. Under the illumination of air mass 1.5G solar simulator, conversion efficiency of the solar cell is enhanced by 34 %. To investigate light propagation behaviors across the interfaces, simulations based on finite-difference time-domain (FDTD) method are also carried out. In addition, 3 layer of PS nanospheres can be coated on the device based on the optimization design by simulations, contributing to the 30% enhancement of conversion efficiency. One of the major bottlenecks restricts light extraction efficiency of LEDs is the limited photon escape cone for light emission. SiO2 nano-honeycombs diffract the waveguide mode out of the device by providing an additional wave vector. At the current injection of 400mA, the optical power of the device is enhanced by 78 %.
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Hsu, Chia-Yang, and 徐嘉陽. "Nanoscale Design to Enable the Photon Management." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/04645996116647920513.
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碩士國立臺灣大學
光電工程學研究所
100
Nanostructures have shown great potential toward better performance than their bulk counterparts. However, every nanomaterials have their own limits, and thus future applications are being hindered. For making a breakthrough, in this study, we show a possible solution by combining two different nanomaterials together. By means of atomic layer deposition, the core-shell multiwalled carbon nanotubes (MCNTs)-TiO2/ZnO nanostructures could make the thickness control accurate. Duo to the potential applications of secure communication, a sensitive and fast photodetector (PD) is strongly desirable. However, the core-shell nanowires (NWs) not only converse the high photoconductive gain of the metal oxide semiconductor but also further promote the response speed. This material may pave a promising way for multifunctional NW-based optoelectronics in the future. In addition, a model concerning the connections between two materials is proposed to explain the high photoconductive gain and the fast response speed. First of all, a broadband, fast, and sensitive PD is realized on the basis of MCNT-TiO2 core-shell NW geometry. The devices exhibit high photoconductive gain up to 104 and fast response/recovery times of 4.4/10.2 ms. Advances in the carrier separation occurred in the radial junction in core-shell architecture, the collection of charge could be enhanced. Herein, the interaction between MCNT and TiO2 is demonstrated by photocurrent generation and temporal behavior under varying wavelength illumination. The high photoconductive gain and fast response/recovery times are attributed to the presence of oxygen-related hole-trap states at the NW surface and the radial local electric field between MCNT cores and TiO2 shells duo to Schottky junctions. Furthermore, duo to the optoelectronic properties of core-shell NW, the material has great potential in photovoltaic cells applications. Finally, for astronomical studies and optical communication, self-powered UV devices are much more desired. Herein, we employ the advantages of core-shell nanostructures to fabricate ultrafast, and self-powered ultraviolet (UV) PDs. Although the self-powered devices have been studied recently on the basis of NW-aligned arrays, little attention has paid on driving practical device by a single NW. We not only demonstrate sensitive MCNT-ZnO core-shell NW device with responsivity of 200 A/W and photoconductive gain of 800 under UV laser (325 nm, 100 mW/cm2) but also operate without an external power supply to continuously drive a commercial liquid crystal display. Furthermore, we show the first fast-speed demonstration of MCNT-ZnO-based PDs in vacuum condition with response/recovery times of 29/30 ms duo to the advantages of radial Schottky junctions and thin ZnO shells. We provide multifunctional coaxial nanostructures for the promising application in the future.
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Chang, Hung-Chih, and 張閎智. "Photon Management in Si-Based Solar Cells." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/32878939324121539000.
Full textAbstract:
碩士國立臺灣大學
光電工程學研究所
99
In this thesis, first, the nanowire array (NWA) layers with controlled structure profiles fabricated by maskless galvanic wet etching on Si substrates are found to exhibit extremely low specular reflectance (< 0.1 %) in the wavelengths of 200-850 nm. The significantly suppressed reflection is accompanied with other favorable antireflection (AR) properties, including omnidirectionality and polarization-insensitivity. The NWA layers are also effective in suppressing the undesired diffuse reflection. These excellent AR performances benefit from the rough interfaces between air/NWA layers and NWA layers/substrate and the decreased nanowire densities, providing the gradient of effective refractive indices. The Raman intensities of Si NWAs were enhanced by up to 400 times as compared with the signal of the polished Si, confirming that the NWA layers enhance both insertion and extraction efficiencies of light. This study provides an insight into the interaction between light and nanostrucutres, and should contribute to the structural optimization of various optoelectronic devices. Second, wafer-scale nanowire arrays (NWAs) with hierarchical structure, combined the nanowire and interface micro-roughness were fabricated by single process of costless wet etching. The NWA based solar cells with designed hierarchical structure demonstrate excellent light-harvesting characteristics, such as broadband working ranges and omnidirectionality in external quantum efficiency and reflectance measurement. Compared to the polished Si and conventional NWAs, the solar cell with hierarchical structure exhibits significantly superior photovoltaic characteristics, i.e., short-circuit current of 32.7 mA/cm2 and conversion efficiency of 11.25 %. The enhanced photovoltaic performances agree with the theoretical analysis based on a finite-difference time-domain method. A viable scheme for light harvesting using the hierarchical structure employing micro-roughness/nanoscale surface textures on single crystalline Si solar cells has been demonstrated. Third, antireflective Si/oxide core-shell nanowire arrays (NWAs) were fabricated by galvanic etching and subsequent annealing process. The excellent light-harvesting characteristics of the core-shell NWAs, such as broadband working ranges, omnidirectionality, and polarization-insensitivity, ascribed to the smooth index transition from air to the substrates, have been demonstrated. By tuning core-shell volume ratios, we obtained enhanced light trapping regions implemented in either the planar Si underneath NWAs or the core regions of NWAs, greatly benefiting the geometry design of planar and radial p-n junction cell structures, respectively. This photon management scheme indicates the potential use in nanostructured photovoltaic applications. Finally, rough AZO films were employed to enhance the internal scattering and consequent optical absorption of thin film (amorphous/polycrystalline Si) tandem solar cells. Through the optimization work by simulations, the matched current densities from the top and the bottom cells were obtained with the device structure containing 1.5-μm roughened polycrystalline Si layer, which produces the efficiencies comparable to those of the 3.5-μm layer without roughening. The simulation results were supported by the device performances measured experimentally. The significantly enhanced light scattering in the thin rough active region was revealed by the calculation results based on finite-difference time-domain method. The concept and technique presented in this study should benefit the development of next generation of thin film solar cells.
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Hsiao, Yu-Hsuan, and 蕭宇瑄. "Photon management and radiation resistance of InGaN-based quantum well devices." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/32826052654303351129.
Full text
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Kijatkin, Christian. "Ultrafast Photon Management: The Power of Harmonic Nanocrystals in Nonlinear Spectroscopy and Beyond." Doctoral thesis, 2019. https://repositorium.ub.uni-osnabrueck.de/handle/urn:nbn:de:gbv:700-201904011323.
Full textAbstract:
The present work broaches the physics of light-matter interaction, chiefly using nonlinear optical spectroscopy in a newly developed framework termed as Photon Management Concept. This way, existing fragments dealing with specific properties of harmonic and upconversion nanoparticles (HNPs/UCNPs) are consolidated into a full and coherent picture with the primary goal of understanding the underlying physical processes and their impact on the application side, especially in terms of imaging techniques, via suitable experimental and numerical studies.
Contemporary optical setups involving contrast-enhancing agents are frequently limited in their excitation and detection configurations owing to a specialization to a select number of markers. As a result, the bandwidth of experimental methods and specimens that may be investigated is severely restricted in a large number of state-of-the-art setups. Here, an alternative approach involving HNPs and UCNPs, respectively, is presented providing an overview from their synthesis to optical characterization and to potential fields of application. Based on their inherent flexibility based on their nonlinear optical response, especially in terms of wavelength and intensity tunability, the PMC alleviates prevalent limitations by dynamically adapting the setup to a sample instead of the preliminary culling to a reduced number of eligible specimens that must not change their optical properties significantly during investigation.
The use of HNPs supersedes such concerns due to their nearly instantaneously generated, strongly anti-Stokes shifted, coherent emission capable of producing radiation throughout the visible spectral range, including infrared and ultraviolet wavelengths. This way, HNPs transcend the traditional field of imaging and introduces potential applications in optomanipulation or holographic techniques. Thorough (nonlinear) optical characterization of UCNPs and alkali niobate HNP ensembles is performed to assess the fundamental physical mechanisms interwoven with numerical studies leading to their wide-ranging applicability. Final remarks show that HNPs are ideal candidates for realization of the PMC and yet hold an even further potential beyond current prospects.
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Winterton, Ruth. "The use of technetium 99m hexa-methyl propylene amine oxime spect scanning in acute stroke management." Thesis, 1991. https://hdl.handle.net/10539/26446.
Full textAbstract:
A short report submitted to the Faculty of Medicine,
University of the Witwatersrand in partial fulfilment of the
requirements for the degree of Master of Medicine in Nuclear
Medicine19 patients were selected, from the patients screened, for investigation within 48 hours of the onset of an ischaemic cerebrovascular accident. Clinical neurulogical scoring, computerized tomography lCT) scans and single photon emission computed tomography (SPECT) scans were performed on day 1, day 10 and day 30. SPECT scan data was analysed by 5 semi-quantitative methods, and findings were compared with neuroloyical clinical scores on each respective day. It was found that day 1 SPECT scans are of value for early localization of the acute ischaemic infarction. A multiple regression model was developed using both the day 30 Defect Volume index and segmental analysis score which related to the day 30 clinical scores. The day 1 model was unsatisfactory and no such model was found relating day 10 SPECT semi-quantitative methods to day 10 clinical scoring. Changes in semi-quantitative scores from day 1 to day 30 did not correlate with clinical changes. Longer follow up may be required for there to be value in performing SPECT scans in stroke trials. A prognostic equation was derived by multiple regression analysis of day 1 SPECT scan scores and day 30 clinical scores.
Andrew Chakane 2019
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Liao, Han-Teng, and 廖漢騰. "Blog-Based Photo Management System." Thesis, 2004. http://ndltd.ncl.edu.tw/handle/04827736108074410865.
Full textAbstract:
碩士國立臺灣大學
資訊工程學研究所
92
Most photo management systems are based on the concept of albums with that of category. This paper proposed an alternative that is based on the concept of blog systems, using hyperlinks (or trails) and semantic markup to manage photos. The approach is improved by an examination of the issues related to personal archive systems. The implementation of this approach adopts several standards. In order to keep the information safe from the so-called "Dear Appy" problem (the data files of certain application programs might not be accessible at all times, especially when those programs become obsolete), our implementation adopts XHTML standard. Our implementation includes one-to-many hyperlinks that can be used both as a way of organizing data. The implementation of one-to-many hyperlinks also works with current browsers and is similar to the future standard of one-to-many hyperlinks described in XHTML 2.0 working draft. Our implementation also introduces and designs some semantic markups related to photo management. Finally our implementation also transforms the semantics-rich hyperlinks into RDF data; and with these RDF data, it also produces a graph that demonstrates the relationship between resources.
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Liu, Ming-Liang. "Photoware Interface Design for Better Photo Management." Thesis, 2006. http://hdl.handle.net/1805/620.
Full textAbstract:
Submitted to the faculty of the School of Informatics in partial fulfillment of the requirements for the degree Master of Sciences in the School of Informatics Indiana University December 2005Digital photography has largely replaced traditional film-based photography. Low cost and easy creation of digital files encourage people to take more photographs (photos) than before. Photo management involves selecting photos for placement into albums for future review and publishing them through different media in order to share with others. Photoware is designed to help people manage a large amount of digital photographs. To manage digital photos more efficiently, not only does software performance need to be improved, but also the usability of the software design needs to be refined. Well designed interfaces are one of the solutions to expedite the photo management tasks. The purpose of the study was to design a new photoware interface that would allow users to execute photo management tasks more efficiently. A three-phase study was designed to assess and compare Adobe Photoshop Album with Google Picasa. Phase one identified two major features that were problematic: 1) visibility of images with the photo tray features and 2) the non-existence of export templates that allow photo format settings to be placed into memory for future use. In Phase two, these two features were designed and implemented through paper and dynamic prototypes. Phase three consisted of usability testing of the prototypes. Thirty university students participated in a time-on-task study to measure the performance of the new interface. Also, user preferences were recorded through a post-task questionnaire. The users performed more quickly on the interface design with the two new features, as well as preferred them over the existing products when using mean values. However, the statistical correlation (Spearman - rank order correlation) between the two usability variables was not significant. The lack of correlation was supported by Frøkjær et al.’s view that usability measures should be considered independently. In other words, task time performance alone cannot be used to predict general user preference, because subjective preference could be affected by a range of other factors.
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Hsieh, Bing-Cheng, and 謝秉承. "A Photo Management System Based on Face Recognition." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/vt5upc.
Full textAbstract:
碩士國立臺北科技大學
資訊工程系研究所
97
With the increasing availability of digital cameras, one can easily collect a large number of photos. In this paper, we present a prototype system aimed to achieve efficient management of photos of people. Using current face detection and recognition technologies, we provide both automatic and semi-automatic methods to facilitate the job of associating photos to people. A series of preprocessing methods are taken to improve recognition rate for faces captured in varying lighting conditions and poses. We found that a personal photo collection of a single event may contain only a limited group of people. We can set up a face classifier specific for the group of people. A threshold scheme separates people not in the group or faces that can not be confidently identified apart. The organized result helps pick out incorrectly identified faces. A semi-automatic approach is used to deal with the leftovers by giving three candidates to choose from. Our proposed system is equipped with comprehensive user interface designed for these tasks. We conducted a simulation of this usage showing that it can dramatically reduce the amount of work on a very large set of photos.
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I-Feng, Huang. "High Performance Fault Management Schemes for Photonic Networks." 2005. http://www.cetd.com.tw/ec/thesisdetail.aspx?etdun=U0009-0112200611292333.
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Huang, I.-Feng, and 黃一峰. "High Performance Fault Management Schemes for Photonic Networks." Thesis, 2005. http://ndltd.ncl.edu.tw/handle/16844265990243567167.
Full textAbstract:
博士元智大學
資訊工程學系
93
ABSTRACT This dissertation proposes a tabular method and a mesh-ring search method for designing fault management mechanisms in Optical Multistage Interconnection Networks (OMINs) and Wavelength Division Multiplexing (WDM) networks, respectively. Limitations of previous literature are discussed, in which heuristic methods are adopted to diagnose crosstalk fault for OMINs. A deterministic algorithm called tabular method is then proposed to record all possible conflicting connections into a table; the connections are then assembled into several conflict-free test set. The first application is used to identify the optimal testing procedure from all possible solutions in the crosstalk fault diagnosis. Results of the proposed method always closely correspond to the optimal fault clusters or minimal test sets for crosstalk fault detection and location procedures. The second application of the tabular method is used to design a fault tolerant mechanism, which is called a fault-free connections scheduling algorithm in the Dilated Benes Network (DBN). The proposed algorithm establishes connections between arbitrary input/output pairs in a minimum number of rounds and averts faulty switches to increase system reliability in DBN. The OMINs can be utilized as major components in the WDM networks, including Optical Add-Drop Multiplexer (OADM), Optical Cross-Connect (OXC), and star coupler, to exchange optical signals. Once the OMINs components in the WDM networks have deteriorated, the entire system performance declines. This dissertation also designs a fault tolerant mechanism for WDM networks. The fault tolerant (commonly referred to as fault recovery) mechanism for WDM networks can be categorized as either protection or restoration. In the protection mechanism, each connection reserves backup paths statically during call setup. In the restoration mechanism, each connection that traverses a failed block discovers dynamically an adaptive backup route after failures occur. For various fault protection requests, the protection mechanism can be either a dedicated or shared facility. Depending on where a detour originates, the fault recovery mechanism can be classified into either link, path or segment recovery method. While previous studies addressing fault recovery issue in WDM networks largely focused on the link and path recovery, segment recovery in WDM networks has seldom been investigated. Networks have become increasingly complex given the accelerated demand for a larger bandwidth. Mesh networks are widely considered to be flexible, scalable, bandwidth-efficient, cost effective, and dynamic. Therefore, this dissertation investigates segment recovery schemes in the WDM mesh networks. To consider their feasibility, a mesh-ring search method is proposed to derive the adaptive recovery paths. Each node in the networks searches independently for its own mesh-rings; these mesh-rings then become adaptive recovery paths after calculation. The first application is used to design a segment protection mechanism in WDM networks, and then two schemes are presented. The first scheme in this application is called Dynamic Shared Segment Protection (DSSP). This algorithm uses pre-calculated mesh-rings to divide the working path into several working segments; resources are then reserved to protect these working segments. The proposed DSSP algorithm can utilize resources efficiently and increase the rate of successful protection, making it applicable in arbitrary mesh networks. The second scheme in this application is in the implementation perspective of segment protection, which is called Overlap Segment Protection (OSP) and Non-Overlap Segment Protection (NOSP). This scheme also applies pre-calculated mesh-rings to construct adaptive protection segments, which can or cannot overlap each other. The second application is used to design a fault restoration mechanism called Dynamic Multiple Ring Algorithm (DMRA) for the WDM mesh networks. DMRA pre-computes the mesh-ring architecture before faults occur enabling the proposed DMRA algorithm to recover quickly from failures and determine how to allocate recovered traffic loads based on the current traffic load and the network bandwidth along the restoration paths. The third application integrates previous applications to design a recovery mechanism called Guaranteed Quality of Recovery (GQoR). Four classes of priority for GQoR mechanism are applied based on the customer’s request, with each one mapped to the adaptive recovery method. The GQoR mechanism confirms that customers possess an efficient recovery time and sufficient backup resources. The above fault management methods in photonic networks are introduced, developed, and simulated herein. Simulation results demonstrate the feasibility of applying the proposed methods in real-world networks.
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"Digital photo album management techniques: from one dimension to multi-dimension." 2005. http://library.cuhk.edu.hk/record=b5892580.
Full textAbstract:
Lu Yang.Thesis submitted in: November 2004.
Thesis (M.Phil.)--Chinese University of Hong Kong, 2005.
Includes bibliographical references (leaves 96-103).
Abstracts in English and Chinese.
Abstract --- p.i
Acknowledgement --- p.iv
Chapter 1 --- Introduction --- p.1
Chapter 1.1 --- Motivation --- p.1
Chapter 1.2 --- Our Contributions --- p.3
Chapter 1.3 --- Thesis Outline --- p.5
Chapter 2 --- Background Study --- p.7
Chapter 2.1 --- MPEG-7 Introduction --- p.8
Chapter 2.2 --- Image Analysis in CBIR Systems --- p.11
Chapter 2.2.1 --- Color Information --- p.13
Chapter 2.2.2 --- Color Layout --- p.19
Chapter 2.2.3 --- Texture Information --- p.20
Chapter 2.2.4 --- Shape Information --- p.24
Chapter 2.2.5 --- CBIR Systems --- p.26
Chapter 2.3 --- Image Processing in JPEG Frequency Domain --- p.30
Chapter 2.4 --- Photo Album Clustering --- p.33
Chapter 3 --- Feature Extraction and Similarity Analysis --- p.38
Chapter 3.1 --- Feature Set in Frequency Domain --- p.38
Chapter 3.1.1 --- JPEG Frequency Data --- p.39
Chapter 3.1.2 --- Our Feature Set --- p.42
Chapter 3.2 --- Digital Photo Similarity Analysis --- p.43
Chapter 3.2.1 --- Energy Histogram --- p.43
Chapter 3.2.2 --- Photo Distance --- p.45
Chapter 4 --- 1-Dimensional Photo Album Management Techniques --- p.49
Chapter 4.1 --- Photo Album Sorting --- p.50
Chapter 4.2 --- Photo Album Clustering --- p.52
Chapter 4.3 --- Photo Album Compression --- p.56
Chapter 4.3.1 --- Variable IBP frames --- p.56
Chapter 4.3.2 --- Adaptive Search Window --- p.57
Chapter 4.3.3 --- Compression Flow --- p.59
Chapter 4.4 --- Experiments and Performance Evaluations --- p.60
Chapter 5 --- High Dimensional Photo Clustering --- p.67
Chapter 5.1 --- Traditional Clustering Techniques --- p.67
Chapter 5.1.1 --- Hierarchical Clustering --- p.68
Chapter 5.1.2 --- Traditional K-means --- p.71
Chapter 5.2 --- Multidimensional Scaling --- p.74
Chapter 5.2.1 --- Introduction --- p.75
Chapter 5.2.2 --- Classical Scaling --- p.77
Chapter 5.3 --- Our Interactive MDS-based Clustering --- p.80
Chapter 5.3.1 --- Principal Coordinates from MDS --- p.81
Chapter 5.3.2 --- Clustering Scheme --- p.82
Chapter 5.3.3 --- Layout Scheme --- p.84
Chapter 5.4 --- Experiments and Results --- p.87
Chapter 6 --- Conclusions --- p.94
Bibliography --- p.96
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Wang, Chao-Yi, and 王昭懿. "The Study of Management for Physical Store Combing with Photo Kiosk." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/17701005773424324895.
Full textAbstract:
碩士大葉大學
工業工程與科技管理學系
96
When the government practices 2-days-off-per-week policy, Taiwanese have more time to plan their weekend trips. People are used to take pictures in tourist attractions to capture their happy memories. With the enhancement of digital technology, digital cameras almost replace traditional ones. Thus, digital media vary; digital photo outputs popularize; even photo-sharing devices increase. Besides, PC’s operation systems enhance digital cameras’ compatibility. It impacts traditional photo printing that digital cameras’ application is replacing traditional ones’. The research targeted at the strategic alliance of tourism and photography, which has significant relation. Combining Photo Kiosk and a fast-print digital printer can directly and quickly print out any digital content. We used questionnaire to investigate whether consumers accept digital Photo Kiosk. We also built a business model incorporating compound business with physical stores and considered the possibility of outsourcing strategic alliance. The research’s results are: 1.Through the questionnaire, we knew consumers’ habits of picture taking and photo printing. We analyzed their needs to provide Kiosk improvement marketing strategy. 2.After analyzed consumers’ needs, we understood that Photo Kiosk implementation is critical in tourism. 3.We scrutinized outsourcing strategic alliance of setting Photo Kiosk in tourist attractions all over Taiwan.
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王華昌. "A study of the distributor management of digital photo frame SOC." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/72211358352752229426.
Full textAbstract:
碩士國立交通大學
管理學院碩士在職專班國際經貿組
96
A great event for the gift market is annual Christmas. Beside conventional gifts, there are many electronic gifts like celluar phones, digital cameras, portable DVD players, portable TVs… etc. Those are very important electronic gifts in recent years. Since 2006, the digital photo frame generally became the new one of popular electronic gifts. It’s no loyalty fee and forms a new application market for customer electronic industries. Besides of the industry design, TFT-LCD panel, electric board design is the most important issue of the digital photo frame system development. The features and prices of the digital photo frame SOC influence the system operations, functions and total BOM cost of digital photo frames. Digital photo frame SOC integrates hareware like JPEG, Motion JPEG decode of digital camera photographing, storage device interface (card reader, USB Host/Device, NOR/NAND Flash), 16/32 bit CPU, SDRAM control interface, TFT-LCD panel control unit, audio output unit…etc. It also integrates kernel, compact operation system, driver, middleware, and application as well as user interface design. Besides of integrating above technologies, digital photo frame SOC design house must do customers’ system design with its distributors. The SOC agents own many FAEs (Field Application Engineer) who understand IC spec and application well and could provide the demo system, reference circuit, PCB layout, reference code and do the total solution of electronic boards by customer request. Their sales keep good customer relationships with purchasers, research and development persons and key decision-makers to get the orders. The FAEs help customers’ projects develop and sales keep the relationship and do business and promotion over and over. The capability of the SOC distributors influences directly to its IC design company about 30 to 70 percent revenue. The customers of agents comprise middle and small size ones and are sources of higher profit of the IC design company. The SOC distributor management that involves the management subjects like technology, business, inspiration, conflict and strategy…etc is the main topic of this research.
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"Integrated Distributed Power Management System for Photovoltaic." Doctoral diss., 2014. http://hdl.handle.net/2286/R.I.25861.
Full textAbstract:
abstract: Photovoltaic (PV) systems are affected by converter losses, partial shading and other mismatches in the panels. This dissertation introduces a sub-panel maximum power point tracking (MPPT) architecture together with an integrated CMOS current sensor circuit on a chip to reduce the mismatch effects, losses and increase the efficiency of the PV system. The sub-panel MPPT increases the efficiency of the PV during the shading and replaces the bypass diodes in the panels with an integrated MPPT and DC-DC regulator. For the integrated MPPT and regulator, the research developed an integrated standard CMOS low power and high common mode range Current-to-Digital Converter (IDC) circuit and its application for DC-DC regulator and MPPT. The proposed charge based CMOS switched-capacitor circuit directly digitizes the output current of the DC-DC regulator without an analog-to-digital converter (ADC) and the need for high-voltage process technology. Compared to the resistor based current-sensing methods that requires current-to-voltage circuit, gain block and ADC, the proposed CMOS IDC is a low-power efficient integrated circuit that achieves high resolution, lower complexity, and lower power consumption. The IDC circuit is fabricated on a 0.7 um CMOS process, occupies 2mm x 2mm and consumes less than 27mW. The IDC circuit has been tested and used for boost DC-DC regulator and MPPT for photo-voltaic system. The DC-DC converter has an efficiency of 95%. The sub-module level power optimization improves the output power of a shaded panel by up to 20%, compared to panel MPPT with bypass diodes.Dissertation/Thesis
Doctoral Dissertation Electrical Engineering 2014
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Wu, Fuqu. "Visualizing things in construction photos: time, spatial coverage, and content for construction management." Thesis, 2009. http://hdl.handle.net/1828/1481.
Full textAbstract:
PhotoScope, a novel visualization, visualizes the spatiotemporal coverage of photos in a construction photo collection. It extends the standard photo browsing paradigm in two main ways: visualizing spatial coverage of photos on floor plans, and indexing photos by a combination of spatial coverage, time, and content specifications. This approach enables users to browse and search space- and time-indexed photos more effectively. We designed PhotoScope specifically to address challenges in the construction management industry, where large photo collections are amassed to document project progress. These ideas may also apply to any photo collection that is spatially constrained and must be searched using spatial, temporal, and content criteria. Design choices made when developing PhotoScope are also described.
Civil, mechanical and electrical engineers, and professionals from construction management validated the visualization mechanisms and functionalities of PhotoScope in a usability study. Empirical findings on the cognitive behaviors of participants are also discussed in this thesis.
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Lin, Chia-Hung, and 林家弘. "Consumer Photo Management and Browsing Facilitated by Near-Duplicate Detection with Feature Filtering." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/09984787163988146626.
Full textAbstract:
碩士國立中正大學
資訊工程所
97
With the rapid growth of the number of digital photographs, people urgently demand systems that facilitate intelligent management and browsing. We specially focus on photos taken in travels. To conduct these issues, we present two primary objectives, i.e., representative selection and region-of-interest (ROI) determination. We propose a framework based on the techniques of near-duplicate detection to facilitate efficient photo management and browsing. To filter out false matches generated by feature points matching, we propose three feature filtering methods, including probability latent semantic analysis (PLSA) filtering, point-based filtering, and region-based filtering. For a given travel photo cluster, we model matching patterns by a support vector machine (SVM) classifier, which determinate whether two photos are near-duplicate pair or not. Relationships between near-duplicate photos are represented as a graph, and then the photo with the highest centrality value is selected as the representative photo in the given photo cluster. Because matched feature points are often located in the interior or at the contour of important objects, the region that compactly covers the matched feature points is determined as the ROI. In experimental results, we compare the performance of three feature classifiers, and confirm that filtering out noisy feature points is conducive to representative selection. We further apply the proposed framework to other interesting researches, such as image re-ranking.
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Hua, Chengyun. "Exploring Thermal Phonon Transport from Atomic to Macroscopic Scales for Energy Conversion and Management." Thesis, 2016. https://thesis.library.caltech.edu/9832/84/main.pdf.
Full textAbstract:
Heat is one of the most fundamental forms of energy, and the ability to control heat plays a critical role in most current and future energy applications. Recently, interface engineering between heterogeneous solids has provided new approaches to manipulate heat transport at the scales of the energy carriers in solids, i.e. phonons which are quantized lattice vibrations. For example, nanocrystalline materials, which are polycrystalline materials with nanoscale grain sizes, are promising thermoelectric (TE) materials that have achieved substantially improved figure of merits compared to their bulk counterparts. This enhancement is typically attributed to a reduction in lattice thermal conductivity by phonon scattering at grain boundaries. On the other hand, inefficient heat dissipation across interfaces has been a long-standing problem that shortens the lifetime of electronics such as light-emitting diodes.
Despite the importance of interfaces, we still lack a comprehensive understanding of interfacial thermal phonon transport. For instance, the Fresnel coefficients enable the straightforward mathematical description of light as it moves between media of differing dielectric constants. Similarly, interfacial phonon transport can also be characterized by transmission coefficients that vary over the broad phonon spectrum in an analogous manner to Fresnel coefficients for light. However, despite decades of work, the spectral profile of these coefficients and how the profile is influenced by the atomic structure of actual interfaces remains unclear. As a result, the basic phenomenon of interfacial heat transport remains among the most poorly understood transport processes.
To elucidate this process, in this thesis we investigate interfacial thermal phonon transport using both modeling and experiment. The first portion of the thesis examines the impact of frequency-dependent grain boundary scattering in nanocrystalline silicon and silicon-germanium alloys using a novel computational method. We find that the grain boundary may not be as effective as commonly considered in scattering certain phonons, with a substantial amount of heat being carried by low frequency phonons with mean free paths longer than the grain size. Our result will help guide the design of more efficient TEs.
The second part of the thesis focuses on studying heat conduction using the Boltzmann transport equation (BTE), which is the governing equation of energy transport at length scales comparable to phonon mean free paths. The BTE is an integro-differential equation of time, real space, and phase space. Due to its high dimensionality, it is extremely challenging to solve. Here, we develop analytical methods to solve the frequency-dependent BTE, which allow us to obtain simple, closed-form solutions to complex multidimensional problems that have previously been possible to solve only with computationally expensive numerical simulations. We demonstrate that the solution leads to a more accurate measurement of phonon MFP spectra in thermal transient grating experiments.
Finally, we report the first measurements of thermal phonon transmission coefficients at a metal-semiconductor interface using ab-initio phonon transport modeling based on the BTE we develop in the second part and a thermal characterization technique, time-domain thermoreflectance. With our approach, we are able to directly link the atomic structure of an interface to the spectral content of the heat crossing it for the first time. Our work realizes the long-standing goal of directly measuring thermal phonon transmission coefficients and demonstrates a general route to study microscopic processes governing interfacial heat conduction.