933 resultados para Third-order
Resumo:
The creative industries sector faces a constantly changing context characterised by the speed of the development and deployment of digital information systems and Information Communications Technologies (ICT) on a global scale. This continuous digital disruption has had significant impact on the whole value chain of the sector: creation and production; discovery and distribution; and consumption of cultural goods and services. As a result, creative enterprises must evolve business and operational models and practices to be sustainable. Enterprises of all scales, type, and operational model are affected, and all sectors face ongoing digital disruption. Management consultancy practitioners and business strategy academics have called for new strategy development frameworks and toolkits, fit for a continuously changing world. This thesis investigates a novel approach to organisational change appropriate to the digital age, in the context of the creative sector in Scotland. A set of concepts, methods, tools, and processes to generate theoretical learning and practical knowing was created to support enterprises to digitally adapt through undertaking journeys of change and organisational development. The framework is called The AmbITion Approach. It was developed by blending participatory action research (PAR) methods and modern management consultancy, design, and creative practices. Empirical work also introduced to the framework Coghlan and Rashford’s change categories. These enabled the definition and description of the extent to which organisations developed: whether they experienced first order (change), second order (adaptation) or third order (transformation) change. Digital research tools for inquiry were tested by a pilot study, and then embedded in a longitudinal study over two years of twentyone participant organisations from Scotland’s creative sector. The author applied and investigated the novel approach in a national digital development programme for Scotland’s creative industries. The programme was designed and delivered by the author and ran nationally between 2012-14. Detailed grounded thematic analysis of the data corpus was undertaken, along with analysis of rich media case studies produced by the organisations about their change journeys. The results of studies on participants, and validation criteria applied to the results, demonstrated that the framework triggers second (adaptation) and third order change (transformation) in creative industry enterprises. The AmbITion Approach framework is suitable for the continuing landscape of digital disruption within the creative sector. The thesis contributes to practice the concepts, methods, tools, and processes of The AmbITion Approach, which have been empirically tested in the field, and validated as a new framework for business transformation in a digital age. The thesis contributes to knowledge a theoretical and conceptual framework with a specific set of constructs and criteria that define first, second, and third order change in creative enterprises, and a robust research and action framework for the analysis of the quality, validity and change achieved by action research based development programmes. The thesis additionally contributes to the practice of research, adding to our understanding of the value of PAR and design thinking approaches and creative practices as methods for change.
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New fully relativistic calculations of radiative rates and electron impact excitation cross-sections for Fe XVI are used to determine theoretical emission-line ratios applicable to the 251-361 and 32-77 angstrom portions of the extreme-ultraviolet (EUV) and soft X-ray spectral regions, respectively. A comparison of the EUV results with observations from the Solar Extreme-Ultraviolet Research Telescope and Spectrograph (SERTS) reveals excellent agreement between theory and experiment. However, for emission lines in the 32-49 angstrom portion of the soft X-ray spectral region, there are large discrepancies between theory and measurement for both a solar flare spectrum obtained with the X-Ray Spectrometer/Spectrograph Telescope (XSST) and for observations of Capella from the Low- Energy Transmission Grating Spectrometer (LETGS) on the Chandra X-ray Observatory. These are probably due to blending in the solar flare and Capella data from both first-order lines and from shorter wavelength transitions detected in second and third order. By contrast, there is very good agreement between our theoretical results and the XSST and LETGS observations in the 50-77 angstrom wavelength range, contrary to previous results. In particular, there is no evidence that the Fe XVI emission from the XSST flare arises from plasma at a much higher temperature than that expected for Fe XVI in ionization equilibrium, as suggested by earlier work.
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A newly introduced inverse class-E power amplifier (PA) was designed, simulated, fabricated, and characterized. The PA operated at 2.26 GHz and delivered 20.4-dBm output power with peak drain efficiency (DE) of 65% and power gain of 12 dB. Broadband performance was achieved across a 300-Mitz bandwidth with DE of better than 50% and 1-dB output-power flatness. The concept of enhanced injection predistortion with a capability to selectively suppress unwanted sub-frequency components and hence suitable for memory effects minimization is described coupled with a new technique that facilitates an accurate measurement of the phase of the third-order intermodulation (IM3) products. A robust iterative computational algorithm proposed in this paper dispenses with the need for manual tuning of amplitude and phase of the IM3 injected signals as commonly employed in the previous publications. The constructed inverse class-E PA was subjected to a nonconstant envelope 16 quadrature amplitude modulation signal and was linearized using combined lookup table (LUT) and enhanced injection technique from which superior properties from each technique can be simultaneously adopted. The proposed method resulted in 0.7% measured error vector magnitude (in rms) and 34-dB adjacent channel leakage power ratio improvement, which was 10 dB better than that achieved using the LUT predistortion alone.
Resumo:
The phenomenological mechanisms of passive intermodulation (PIM) in printed lines have been explored by mapping intermodulation products generated by the two-tone traveling waves in microstrip lines. Near-field probing based upon a commercial PIM analyzer has been employed for identification of the PIM sources in printed lines. The results of extensive near-field probing provide the direct experimental evidences of cumulative growth of the intermodulation products in the matched uniform microstrip lines and reveal the fundamental role of the nonlinear scattering by the lumped nonlinear inclusions in the intermodulation production. The distributed nature of the PIM generation in microstrip lines has been conclusively demonstrated and comprehensively described in terms of the four-wave mixing process that proved to be fully consistent with the results of experimental observations of third-order PIM products on the matched and mismatched microstrip lines. © 2006 IEEE.
Resumo:
The present paper demonstrates the suitability of artificial neural network (ANN) for modelling of a FinFET in nano-circuit simulation. The FinFET used in this work is designed using careful engineering of source-drain extension, which simultaneously improves maximum frequency of oscillation f(max) because of lower gate to drain capacitance, and intrinsic gain A(V0) = g(m)/g(ds), due to lower output conductance g(ds). The framework for the ANN-based FinFET model is a common source equivalent circuit, where the dependence of intrinsic capacitances, resistances and dc drain current I-d on drain-source V-ds and gate-source V-gs is derived by a simple two-layered neural network architecture. All extrinsic components of the FinFET model are treated as bias independent. The model was implemented in a circuit simulator and verified by its ability to generate accurate response to excitations not used during training. The model was used to design a low-noise amplifier. At low power (J(ds) similar to 10 mu A/mu m) improvement was observed in both third-order-intercept IIP3 (similar to 10 dBm) and intrinsic gain A(V0) (similar to 20 dB), compared to a comparable bulk MOSFET with similar effective channel length. This is attributed to higher ratio of first-order to third-order derivative of I-d with respect to gate voltage and lower g(ds), in FinFET compared to bulk MOSFET. Copyright (C) 2009 John Wiley & Sons, Ltd.
Resumo:
From late 2008 onwards, in the space of six months, international financial regulatory networks centred around the Swiss city of Basel presided over a startlingly rapid ideational shift, the significance and importance of which remains to be deciphered. From being relatively unpopular and very much on the sidelines, the idea of macroprudential regulation (MPR) moved to the centre of the policy agenda and came to represent a new Basel consensus, as the principal interpretative frame, for financial technocrats and regulators seeking to diagnose and understand the financial crisis and to advance institutional blueprints for regulatory reform. This article sets out to explain how and why that ideational shift occurred. It identifies four scoping conditions of presence, position, promotion, and plausibility, that account for the successful rise to prominence of macroprudential ideas through an insiders' coup d'état. The final section of the article argues that this macroprudential shift is an example of a ‘gestalt flip’ or third order change in Peter Hall's terms, but it is not yet a paradigm shift, because the development of first order policy settings and second order policy instruments is still ongoing, giving the macroprudential ideational shift a highly contested and contingent character.
Resumo:
Ambisonics is a scalable spatial audio technique that attempts to present a sound scene to listeners over as large an area as possi- ble. A localisation experiment was carried out to investigate the performance of a first and third order system at three listening positions - one in the centre and two off-centre. The test used a reverse target-pointer adjustment method to determine the error, both signed and absolute, for each combination of listening posi- tion and system. The signed error was used to indicate the direc- tion and magnitude of the shifts in panning angle introduced for the off-centre listening positions. The absolute error was used as a measure of the performance of the listening position and systems combinations for a comparison of their overall performance. A comparison was made between the degree of image shifting be- tween the two systems and the robustness of their off-centre per- formance.
Resumo:
Ambisonics and Higher Order Ambisonics (HOA) are scalable spatial audio techniques that attempt to present a sound scene to listeners over as large an area as possible. A localisation experiment was carried out to investigate the performance of a first and third order system at three listening positions - one in the centre and two off-centre - using a 5 m radius loudspeaker array. The results are briefly presented and compared to those of an earlier experiment on a 2.2 m loudspeaker array. In both experiments the off-centre listeners were placed such that the ratio of distance from the centre to the array radius was constant in both experiments. The test used a reverse target-pointer adjustment method to determine the error, both signed and absolute, for each combination of listening position and system. The results for both arrays were found to be very similar, suggesting that the relative amplitude of the loudspeakers, which were the same in both cases, was more dominant for localisation than the arrival time differences, which differed between array sizes.
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A theoretical analysis is reported in this paper to investigate the effect that a second harmonic signal which might be present at an amplifier’s input has on generating additional intermodulation products, particularly the third-order intermodulation (IM3) products. The analysis shows that the amplitude of an extra generated IM3 component is equal to the product of the fundamental amplitude, the second harmonic amplitude, and the second order Taylor series coefficient. The effect of the second order harmonic on the IM3 is examined through a simulated example of a 2.22-GHz 10-W Class-EF amplifier whereby the IM3 levels have been reduced by 2-3 dB after employing a second harmonic termination stub at the input.
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The Raman spectra of carbon nanotubes prepared by catalytic (C-CNT) and d.c. arc discharge (D-CNT) methods are reported. A previously unnoticed third-order Raman peak at ca. 4248 cm-1 was observed in the Raman spectrum of D-CNT. The Raman features of D-CNT and C-CNT are similar to those of highly oriented pyrolytic graphite (HOPG) and active carbon, respectively. The data also suggest that the increase in disorder in D-CNT compared with HOPG is due to structural defects in D-CNT. © 1997 by John Wiley & Sons, Ltd.
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As comunicações quânticas aplicam as leis fundamentais da física quântica para codificar, transmitir, guardar e processar informação. A mais importante e bem-sucedida aplicação é a distribuição de chaves quânticas (QKD). Os sistemas de QKD são suportados por tecnologias capazes de processar fotões únicos. Nesta tese analisamos a geração, transmissão e deteção de fotões únicos e entrelaçados em fibras óticas. É proposta uma fonte de fotões única baseada no processo clássico de mistura de quatro ondas (FWM) em fibras óticas num regime de baixas potências. Implementamos essa fonte no laboratório, e desenvolvemos um modelo teórico capaz de descrever corretamente o processo de geração de fotões únicos. O modelo teórico considera o papel das nãolinearidades da fibra e os efeitos da polarização na geração de fotões através do processo de FWM. Analisamos a estatística da fonte de fotões baseada no processo clássico de FWM em fibras óticas. Derivamos um modelo teórico capaz de descrever a estatística dessa fonte de fotões. Mostramos que a estatística da fonte de fotões evolui de térmica num regime de baixas potências óticas, para Poissoniana num regime de potências óticas moderadas. Validamos experimentalmente o modelo teórico, através do uso de fotodetetores de avalanche, do método estimativo da máxima verossimilhança e do algoritmo de maximização de expectativa. Estudamos o processo espontâneo de FWM como uma fonte condicional de fotões únicos. Analisamos a estatística dessa fonte em termos da função condicional de coerência de segunda ordem, considerando o espalhamento de Raman na geração de pares de fotões, e a perda durante a propagação de fotões numa fibra ótica padrão. Identificamos regimes apropriados onde a fonte é quase ideal. Fontes de pares de fotões implementadas em fibras óticas fornecem uma solução prática ao problema de acoplamento que surge quando os pares de fotões são gerados fora da fibra. Exploramos a geração de pares de fotões através do processo espontâneo de FWM no interior de guias de onda com suceptibilidade elétrica de terceira ordem. Descrevemos a geração de pares de fotões em meios com elevado coeficiente de absorção, e identificamos regimes ótimos para o rácio contagens coincidentes/acidentais (CAR) e para a desigualdade de Clauser, Horne, Shimony, and Holt (CHSH), para o qual o compromisso entre perda do guia de onda e não-linearidades maximiza esses parâmetros.
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This paper deals with a third order shear deformation finite element model wich is applied on the active resonance control thin plate/shell laminated structures with integrated piezoelectric layers of patches, acting as sensors and actuators. The finite element model is a single layer tringular nonconforming plate/shell element with 24 degrees of freedom for he generalized displacements, and one electrical potential degree of freedom for each piezoelectric element layer, wich are surface bonded on the laminated. The newwork method is considered to calculate the dynamic response of the laminated sructures forced to vibrate in the first natural frequency. To achieve a mechanism of active control of the structure dynamic response, a feedback control algorithm is used, coupling the sensor and active piezoelectric layers. The model is applied to the solution of one illustrative case, and the results are presented and discussed.
Resumo:
This paper presents a low complexity high efficiency decimation filter which can be employed in EletroCardioGram (ECG) acquisition systems. The decimation filter with a decimation ratio of 128 works along with a third order sigma delta modulator. It is designed in four stages to reduce cost and power consumption. The work reported here provides an efficient approach for the decimation process for high resolution biomedical data conversion applications by employing low complexity two-path all-pass based decimation filters. The performance of the proposed decimation chain was validated by using the MIT-BIH arrhythmia database and comparative simulations were conducted with the state of the art.
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Due to the application of active components into antennas these became a source of distortion on wireless communication systems. In this paper we explore the nonlinear effects occurring in a frequency reconfigurable antenna operating with a PIN Diode. We describe the measurement setup used to check the antenna intermodulation products and the measured compression and third order intermodulation limitations of a frequency reconfigurable antenna, operating at the UMTS and WLAN frequencies.
Resumo:
Rates and products of the oxidation of diphenyl sulfide, phenyl methyl sulfide, p-chlorophenyl methyl sulfide and diphenyl sulfoxide have been determined. Oxidants included t-Bu02H alone, t-Bu02H plus molybdenum or vanadium catalysts and the molybdenum peroxo complex Mo0(02)2*HMPT. Reactions were chiefly carried out in ethanol at temperatures ranging from 20° to 65°C. Oxidation of diphenyl sulfide by t-Bu02H in absolute ethanol at 65°C followed second-order kinetics with k2 = 5.61 x 10 G M~1s"1, and yielded only diphenyl sulfoxide. The Mo(C0)g-catalyzed reaction gave both the sulfoxide and the sulfone with consecutive third-order kinetics. Rate = k3[Mo][t-Bu02H][Ph2S] + k^[Mo][t-Bu02H][Ph2S0], where log k3 = 12.62 - 18500/RT, and log k^ = 10.73 - 17400/RT. In the absence of diphenyl sulfide, diphenyl sulfoxide did not react with t-Bu02H plus molybdenum catalysts, but was oxidized by t-Bu02H-V0(acac)2. The uncatalyzed oxidation of phenyl methyl sulfide by t-Bu02H in absolute ethanol at 65°C gave a second-order rate constant, k = 3.48 x 10~"5 M^s""1. With added Mo(C0)g, the product was mainly phenyl methyl sulfoxide; Rate = k3[Mo][t-Bu02H][PhSCH3] where log k3 = 22.0 - 44500/RT. Both diphenyl sulfide and diphenyl sulfoxide react readily with the molybdenum peroxy complex, Mo0(02)2'HMPT in absolute ethanol at 35°C, yielding diphenyl sulfone. The observed features are mainly in agreement with the literature on metal ion-catalyzed oxidations of organic compounds by hydroperoxides. These indicate the formation of an active catalyst and the complexation of t-Bu02H with the catalyst. However, the relatively large difference between the activation energies for diphenyl sulfide and phenyl methyl sulfide, and the non-reactivity of diphenyl sulfoxide suggest the involvement of sulfide in the production of an active species.