953 resultados para Tholos (Athens, Greece).


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Service quality measurement in Internet banking services is an area of growing interest to researchers and managers. This research investigates the interrelationships between the dimensions comprising the Internet banking service quality construct through structural equation modelling. Five Internet service quality dimensions are identified: access, web interface, trust, attention and credibility. Credibility is modelled as an outcome of the causal variables of access, web interface, trust and attention. Trust and attention emerges as key dimensions in explaining the credibility dimension. Access is found to be a common antecedent of trust, attention and Web interface dimensions. Implications from the findings are offered.

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Finite element simulations have been performed along side Galerkin-type calculations that examined the development of volumetrically heated flow patterns in a horizontal layer controlled by the Prandtl number, Pr, and the Grashof number, Gr. The fluid was bounded by an isothermal plane above an adiabatic plane. In the simulations performed here, a number of convective polygonal planforms occurred, as Gr increased above the critical Grashof number, Grc at Pr = 7, while roll structures were observed for Pr < 1 at 2Grc.

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Over the past two years there have been several large-scale disasters (Haitian earthquake, Australian floods, UK riots, and the Japanese earthquake) that have seen wide use of social media for disaster response, often in innovative ways. This paper provides an analysis of the ways in which social media has been used in public-to-public communication and public-to-government organisation communication. It discusses four ways in which disaster response has been changed by social media: 1. Social media appears to be displacing the traditional media as a means of communication with the public during a crisis. In particular social media influences the way traditional media communication is received and distributed. 2. We propose that user-generated content may provide a new source of information for emergency management agencies during a disaster, but there is uncertainty with regards to the reliability and usefulness of this information. 3. There are also indications that social media provides a means for the public to self-organise in ways that were not previously possible. However, the type and usefulness of self-organisation sometimes works against efforts to mitigate the outcome of the disaster. 4. Social media seems to influence information flow during a disaster. In the past most information flowed in a single direction from government organisation to public, but social media negates this model. The public can diffuse information with ease, but also expect interaction with Government Organisations rather than a simple one-way information flow. These changes have implications for the way government organisations communicate with the public during a disaster. The predominant model for explaining this form of communication, the Crisis and Emergency Risk Communication (CERC), was developed in 2005 before social media achieved widespread popularity. We will present a modified form of the CERC model that integrates social media into the disaster communication cycle, and addresses the ways in which social media has changed communication between the public and government organisations during disasters.

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In his discussion - Challenge To Managers: Changing Hotel Work from a Secondary Choice to Career Development - by Leonidas Chitiris, Lecturer in Management, Piraeus Graduate School of Industrial Studies, Athens, Greece, Chitiris marginally alludes at the outset: “Surveys and interviews with hotel employees in Greece with regard to why individuals work for hotels and to what extent their rationale to join the hotel industry affects hotel productivity revealed that the choice to work in hotels is a secondary preference and reflects the opportunity structure in the economy at any given time and the greater the number of those who work in hotels when there are no other employment opportunities, the less likely the chances for overall improved performance. Given the increase in the proportion of unskilled, unmotivated workers, the level of hotel productivity consequently decreases! The author interprets the findings in terms of the economic and employment conditions in the Greek hotel industry. To enhance the rationale of his thesis statement, Chitiris offers with citation: “Research on initial entry into the labor force has shown that new employees reflect idealized expectations and are frequently not very satisfied with their jobs and roles in the work settings.” Chitiris advances the thought even further by saying: “Research on job satisfaction, motivation, and production purports that management can initiate policies that develop job satisfaction and may improve productivity.” The author outlines components within the general category of the hotel industry to label and quantify exactly why there may be a lag between employee expectations and the delivery of a superior level of service. Please keep in mind that the information for this essay is underpinned by the hotel industry in Greece, exclusively. Demographic information is provided. One example of the many factors parsed in this hotel service discussion is the employee/guest relationship. “The quality of service in hotels is affected to a great extent by the number of guests a hotel employee has to serve,” Chitiris offers. Additionally, Chitiris’ characterization of the typical hotel employee in Greece is not flattering, but it is an informed and representative view of that lodging labor pool. The description in and of itself begs to explain at least some of why the hotel industry in Greece suffers a consequently diminished capacity of superior service. Ill equipped, under-educated, over-worked, and under-paid are how Chitiris describes most employees in the Hellenist hospitality field. Survey based studies, and formulaic indices are used to measure variables related to productivity; the results may be inconclusive industry wide, but are interesting nonetheless. Also, an appealing table gauges the reasons why hotel workers actually employ themselves in the lodging industry. Chirtiris finds that salary expectations do not rate all that high on the motivational chart and are only marginal when related to productivity. In closing, Chirtiris presents a 5-phase development plan hotels should look to in improving performance and productivity at their respective properties.

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The goal of this work is to present an efficient CAD-based adjoint process chain for calculating parametric sensitivities (derivatives of the objective function with respect to the CAD parameters) in timescales acceptable for industrial design processes. The idea is based on linking parametric design velocities (geometric sensitivities computed from the CAD model) with adjoint surface sensitivities. A CAD-based design velocity computation method has been implemented based on distances between discrete representations of perturbed geometries. This approach differs from other methods due to the fact that it works with existing commercial CAD packages (unlike most analytical approaches) and it can cope with the changes in CAD model topology and face labeling. Use of the proposed method allows computation of parametric sensitivities using adjoint data at a computational cost which scales with the number of objective functions being considered, while it is essentially independent of the number of design variables. The gradient computation is demonstrated on test cases for a Nozzle Guide Vane (NGV) model and a Turbine Rotor Blade model. The results are validated against finite difference values and good agreement is shown. This gradient information can be passed to an optimization algorithm, which will use it to update the CAD model parameters.

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This paper describes an implementation of a method capable of integrating parametric, feature based, CAD models based on commercial software (CATIA) with the SU2 software framework. To exploit the adjoint based methods for aerodynamic optimisation within the SU2, a formulation to obtain geometric sensitivities directly from the commercial CAD parameterisation is introduced, enabling the calculation of gradients with respect to CAD based design variables. To assess the accuracy and efficiency of the alternative approach, two aerodynamic optimisation problems are investigated: an inviscid, 3D, problem with multiple constraints, and a 2D high-lift aerofoil, viscous problem without any constraints. Initial results show the new parameterisation obtaining reliable optimums, with similar levels of performance of the software native parameterisations. In the final paper, details of computing CAD sensitivities will be provided, including accuracy as well as linking geometric sensitivities to aerodynamic objective functions and constraints; the impact in the robustness of the overall method will be assessed and alternative parameterisations will be included.

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A comprehensive database of temperature, salinity and bio-chemical parameters in the Mediterranean and Black Sea has been constructed through comprehensive co-operation between the bordering countries. Statistical climatologies have been computed with all assembled and quality controlled data. The database, designed to initiate and validate prediction models, also represents a system to quality-check new incoming data produced by ocean observing systems.

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A specific modified constitutive equation for a third-grade fluid is proposed so that the model be suitable for applications where shear-thinning or shear-thickening may occur. For that, we use the Cosserat theory approach reducing the exact three-dimensional equations to a system depending only on time and on a single spatial variable. This one-dimensional system is obtained by integrating the linear momentum equation over the cross-section of the tube, taking a velocity field approximation provided by the Cosserat theory. From this reduced system, we obtain the unsteady equations for the wall shear stress and mean pressure gradient depending on the volume flow rate, Womersley number, viscoelastic coefficient and flow index over a finite section of the tube geometry with constant circular cross-section.

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Rolling Contact Fatigue (RCF) is one of the main issues that concern, at least initially, the head of the railway; progressively they can be of very high importance as they can propagate inside the material with the risk of damaging the railway. In this work, two different non-destructive techniques, infrared thermography (IRT) and fibre optics microscopy (FOM), were used in the inspection of railways for the tracing of defects and deterioration signs. In the first instance, two different approaches (dynamic and pulsed thermography) were used, whilst in the case of FOM, microscopic characterisation of the railway heads and classification of the deterioration -- damage on the railways according to the UIC (International Union of Railways) code, took place. Results from both techniques are presented and discussed.

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Mode of access: Internet.

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The work of a group of English writers each letter being signed by an initial indicating the author, as follows. P.-Philip Yorke; C.-Charles Yorke; R.-G.H. Rooke; G.-John Green; W.-Daniel Wray; H.-Henry Heaton; E.-Wm. Heberden; O.-Henry Coventry; L.-John Lawry; T.-Catherine Talbot; B.-Thomas Birch; S.-Samuel Salter. The work was edited by Thomas Birch, the brothers Yorke having the largest share in the composition of the letters.

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Published originally under title: History of Greece. London, 1846-56. 12v.