842 resultados para Flexible shafting


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The significant advancement and growth of organic and flexible electronic applications demand materials with enhanced properties. This paper reports the fabrication of a nonsynthetic polymer thin film using radio frequency plasma polymerisation of 3,7-dimethyl-1,6-octadien-3-ol. The fabricated optically transparent thin film exhibited refractive index of approximately 1.55 at 500 nm and rate of deposition was estimated to be 40 nm/min. The surface morphology and chemical properties of the thin films were also reported in this paper. The optical band gap of the material is around 2.8 eV. The force of adhesion and Young's modulus of the linalool polymer thin films were measured using force-displacement curves obtained from a scanning probe microscope. The friction coefficient of linalool polymer thin films was measured using the nanoscratch test. The calculated Young's modulus increased linearly with increase in input power while the friction coefficient decreased.

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Age estimation from facial images is increasingly receiving attention to solve age-based access control, age-adaptive targeted marketing, amongst other applications. Since even humans can be induced in error due to the complex biological processes involved, finding a robust method remains a research challenge today. In this paper, we propose a new framework for the integration of Active Appearance Models (AAM), Local Binary Patterns (LBP), Gabor wavelets (GW) and Local Phase Quantization (LPQ) in order to obtain a highly discriminative feature representation which is able to model shape, appearance, wrinkles and skin spots. In addition, this paper proposes a novel flexible hierarchical age estimation approach consisting of a multi-class Support Vector Machine (SVM) to classify a subject into an age group followed by a Support Vector Regression (SVR) to estimate a specific age. The errors that may happen in the classification step, caused by the hard boundaries between age classes, are compensated in the specific age estimation by a flexible overlapping of the age ranges. The performance of the proposed approach was evaluated on FG-NET Aging and MORPH Album 2 datasets and a mean absolute error (MAE) of 4.50 and 5.86 years was achieved respectively. The robustness of the proposed approach was also evaluated on a merge of both datasets and a MAE of 5.20 years was achieved. Furthermore, we have also compared the age estimation made by humans with the proposed approach and it has shown that the machine outperforms humans. The proposed approach is competitive with current state-of-the-art and it provides an additional robustness to blur, lighting and expression variance brought about by the local phase features.

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The family of location and scale mixtures of Gaussians has the ability to generate a number of flexible distributional forms. The family nests as particular cases several important asymmetric distributions like the Generalized Hyperbolic distribution. The Generalized Hyperbolic distribution in turn nests many other well known distributions such as the Normal Inverse Gaussian. In a multivariate setting, an extension of the standard location and scale mixture concept is proposed into a so called multiple scaled framework which has the advantage of allowing different tail and skewness behaviours in each dimension with arbitrary correlation between dimensions. Estimation of the parameters is provided via an EM algorithm and extended to cover the case of mixtures of such multiple scaled distributions for application to clustering. Assessments on simulated and real data confirm the gain in degrees of freedom and flexibility in modelling data of varying tail behaviour and directional shape.

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Small, not-for-profit organisations fulfil a need in the economy that is typically not satisfied by for-profit firms. They also operate in ways that are distinct from larger organisations. While such firms employ a substantial proportion of the workforce, research addressing human resource management (HRM) practices in these settings is limited. This article used data collected from five small not-for-profit firms in Australia to examine the way one significant HRM practice – the provision and utilisation of flexible work arrangements – operates in the sector. Drawing on research from several scholarly fields, the article firstly develops a framework comprising three tensions in not-for-profits that have implications for HRM. These tensions are: (1) contradictions between an informal approach to HRM vs. a formal regulatory system; (2) employee values that favour social justice vs. external market forces; and (3) a commitment to service vs. external financial expectations. The article then empirically examines how these tensions are managed in relation to the specific case of flexible work arrangements. The study reveals that tensions around providing and accessing flexible work arrangements are managed in three ways: discretion, leadership style and distancing. These findings more broadly inform the way HRM is operationalised in this under-examined sector.

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Die Vorliegende Arbeit beschäftigt sich mit den Spannungen und Verschiebungen an einem elastischen Halbraum unter einem kreisförmigen biegsamen Fundament, wenn an der Kontaktfläche vollkommenes Haften besteht. Das gemischte Randwertproblem wird mit Hilfe von Hankel-Transformationen auf duale Integralgleichungen von Titchmarsh- Typ zurückgeführt. Für die Berechnung der Spannungen und Verschiebungen werden Gaußsche Quadraturformeln benutzt. Die Ergebnisse werden mit denen verglichen, die man bei glattem Fundament erhält, und der Einfluß der Poisson-Zahl auf die Spannungen und Verschiebungen wird deutlich gemacht. Schließlich werden die Ergebnisse für den praktischen Gebrauch in Diagrammen und Tabellen zusammengefaßt.

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Die Vorliegende Arbeit beschäftigt sich mit den Spannungen und Verschiebungen an einem elastischen Halbraum unter einem kreisförmigen biegsamen Fundament, wenn an der Kontaktfläche vollkommenes Haften besteht. Das gemischte Randwertproblem wird mit Hilfe von Hankel-Transformationen auf duale Integralgleichungen von Titchmarsh- Typ zurückgeführt. Für die Berechnung der Spannungen und Verschiebungen werden Gaußsche Quadraturformeln benutzt. Die Ergebnisse werden mit denen verglichen, die man bei glattem Fundament erhält, und der Einfluß der Poisson-Zahl auf die Spannungen und Verschiebungen wird deutlich gemacht. Schließlich werden die Ergebnisse für den praktischen Gebrauch in Diagrammen und Tabellen zusammengefaßt.

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Vibrational stability of a large flexible, structurally damped spacecraft subject to large rigid body rotations is analysed modelling the system as an elastic continuum. Using solution of rigid body attitude motion under torque free conditions and modal analysis, the vibrational equations are reduced to ordinary differential equations with time-varying coefficients. Stability analysis is carried out using Floquet theory and Sonin-Polya theorem. The cases of spinning and non-spinning spacecraft idealized as a flexible beam plate undergoing simple structural vibration are analysed in detail. The critical damping required for stabilization is shown to be a function of the spacecraft's inertia ratio and the level of disturbance.

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BACKGROUND As blood collection agencies (BCAs) face recurrent shortages of varying blood products, developing a panel comprising donors who are flexible in the product they donate based on same-time inventory demand could be an efficient, cost-effective inventory management strategy. Accounting for prior whole blood (WB) and plasmapheresis donation experience, this article explores current donors’ willingness to change their donation product and identifies the type of information required for such donation flexibility. STUDY DESIGN AND METHODS Telephone interviews (mean, 34 min; SD, 11 min) were conducted with 60 donors recruited via stratified purposive sampling representing six donor groups: no plasma, new to both WB and plasma, new to plasma, plasma, flexible (i.e., alternating between WB and plasma), and maximum (i.e., high frequency alternating between WB and plasma) donors. Participants responded to hypothetical scenarios and open-ended questions relating to their and other donors’ willingness to be flexible. Responses were transcribed and content was analyzed. RESULTS The most frequently endorsed categories varied between donor groups with more prominent differences emerging between the information and support that donors desired for themselves versus that for others. Most donors were willing to change donations but sought improved donation logistics and information regarding inventory levels to encourage flexibility. The factors perceived to facilitate the flexibility of other donors included providing donor-specific information and information regarding different donation types. CONCLUSION Regardless of donation history, donors are willing to be flexible with their donations. To foster a flexible donor panel, BCAs should continue to streamline the donation process and provide information relevant to donors’ experience.

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A versatile and flexible digital pulse programmer for two-pulse, three-pulse, saturation burst and Carr-Purcell sequences is described. Independently variable controls for pulse widths (0.2 mu s to 100 mu s), delay between pulses (0.2 mu s to 100 s) and for number of pulses (1 to 99) for the saturation burst and for the Carr-Purcell sequence, are brought to the front panel. The programmer can be used for one-shot experiments as well as for repetitive experiments.

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This licentiate's thesis analyzes the macroeconomic effects of fiscal policy in a small open economy under a flexible exchange rate regime, assuming that the government spends exclusively on domestically produced goods. The motivation for this research comes from the observation that the literature on the new open economy macroeconomics (NOEM) has focused almost exclusively on two-country global models and the analyses of the effects of fiscal policy on small economies are almost completely ignored. This thesis aims at filling in the gap in the NOEM literature and illustrates how the macroeconomic effects of fiscal policy in a small open economy depend on the specification of preferences. The research method is to present two theoretical model that are extensions to the model contained in the Appendix to Obstfeld and Rogoff (1995). The first model analyzes the macroeconomic effects of fiscal policy, making use of a model that exploits the idea of modelling private and government consumption as substitutes in private utility. The model offers intuitive predictions on how the effects of fiscal policy depend on the marginal rate of substitution between private and government consumption. The findings illustrate that the higher the substitutability between private and government consumption, (i) the bigger is the crowding out effect on private consumption (ii) and the smaller is the positive effect on output. The welfare analysis shows that the less fiscal policy decreases welfare the higher is the marginal rate of substitution between private and government consumption. The second model of this thesis studies how the macroeconomic effects of fiscal policy depend on the elasticity of substitution between traded and nontraded goods. This model reveals that this elasticity a key variable to explain the exchange rate, current account and output response to a permanent rise in government spending. Finally, the model demonstrates that temporary changes in government spending are an effective stabilization tool when used wisely and timely in response to undesired fluctuations in output. Undesired fluctuations in output can be perfectly offset by an opposite change in government spending without causing any side-effects.

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ZnO nanoneedles were successfully deposited on flexible polymer substrates at room temperature by activated reactive evaporation. Neither a catalyst nor a template was employed in this synthesis. These synthesized needles measured 500 - 600 nm in length and its diameter varied from 30 - 15 nm from the base to the tip. The single-crystalline nature of the nanoneedle was observed by high-resolution transmission electron microscopy studies. The Raman studies on these nanoneedles had shown that they are oxygen deficient in nature. A possible growth mechanism has been proposed here, in which the nanoneedles nucleate and grow in the gas phase by vapor-solid mechanism.

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A new tripodal flexible ligand (L) containing pyrazolyl functionality has been prepared and successfully used to obtain a pd(6) (1) molecular double-square and a cu(3) trigonalbipyramidal cage (2), where complex 1 represents the first example of a double-square obtained using a flexible tripodal ligand.

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Flexible objects such as a rope or snake move in a way such that their axial length remains almost constant. To simulate the motion of such an object, one strategy is to discretize the object into large number of small rigid links connected by joints. However, the resulting discretised system is highly redundant and the joint rotations for a desired Cartesian motion of any point on the object cannot be solved uniquely. In this paper, we revisit an algorithm, based on the classical tractrix curve, to resolve the redundancy in such hyper-redundant systems. For a desired motion of the `head' of a link, the `tail' is moved along a tractrix, and recursively all links of the discretised objects are moved along different tractrix curves. The algorithm is illustrated by simulations of a moving snake, tying of knots with a rope and a solution of the inverse kinematics of a planar hyper-redundant manipulator. The simulations show that the tractrix based algorithm leads to a more `natural' motion since the motion is distributed uniformly along the entire object with the displacements diminishing from the `head' to the `tail'.

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This paper presents a flexible and integrated planning tool for active distribution network to maximise the benefits of having high level s of renewables, customer engagement, and new technology implementations. The tool has two main processing parts: “optimisation” and “forecast”. The “optimization” part is an automated and integrated planning framework to optimize the net present value (NPV) of investment strategy for electric distribution network augmentation over large areas and long planning horizons (e.g. 5 to 20 years) based on a modified particle swarm optimization (MPSO). The “forecast” is a flexible agent-based framework to produce load duration curves (LDCs) of load forecasts for different levels of customer engagement, energy storage controls, and electric vehicles (EVs). In addition, “forecast” connects the existing databases of utility to the proposed tool as well as outputs the load profiles and network plan in Google Earth. This integrated tool enables different divisions within a utility to analyze their programs and options in a single platform using comprehensive information.

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Using asymptotics, the coupled wavenumbers in an infinite fluid-filled flexible cylindrical shell vibrating in the beam mode (viz. circumferential wave order n = 1) are studied. Initially, the uncoupled wavenumbers of the acoustic fluid and the cylindrical shell structure are discussed. Simple closed form expressions for the structural wavenumbers (longitudinal, torsional and bending) are derived using asymptotic methods for low- and high-frequencies. It is found that at low frequencies the cylinder in the beam mode behaves like a Timoshenko beam. Next, the coupled dispersion equation of the system is rewritten in the form of the uncoupled dispersion equation of the structure and the acoustic fluid, with an added fluid-loading term involving a parameter mu due to the coupling. An asymptotic expansion involving mu is substituted in this equation. Analytical expressions are derived for the coupled wavenumbers (as modifications to the uncoupled wavenumbers) separately for low- and high-frequency ranges and further, within each frequency range, for large and small values of mu. Only the flexural wavenumber, the first rigid duct acoustic cut-on wavenumber and the first pressure-release acoustic cut-on wavenumber are considered. The general trend found is that for small mu, the coupled wavenumbers are close to the in vacuo structural wavenumber and the wavenumbers of the rigid-acoustic duct. With increasing mu, the perturbations increase, until the coupled wavenumbers are better identified as perturbations to the pressure-release wavenumbers. The systematic derivation for the separate cases of small and large mu gives more insight into the physics and helps to continuously track the wavenumber solutions as the fluid-loading parameter is varied from small to large values. Also, it is found that at any frequency where two wavenumbers intersect in the uncoupled analysis, there is no more an intersection in the coupled case, but a gap is created at that frequency. This method of asymptotics is simple to implement using a symbolic computation package (like Maple). (C) 2008 Elsevier Ltd. All rights reserved.