3,928 research outputs found

    Market power versus efficient-structure in Arab GCC banking

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    This paper evaluates the performance of the Arab GCC banking industry in the context of the Structure-Conduct-Performance hypothesis in the period 1993-2002. The paper uses panel estimation differentiating between bank fixed effects and country fixed effects. It examines the Relative-Market-Power and the Efficient-Structure hypotheses differentiating between the two by employing a non-parametric measure of technical efficiency, and finds that the banking industry in the Arab GCC countries is best explained by the mainstream SCP hypothesis. The empirical results do not find any support for the Hicks (1935) “Quiet Life” version of the market power hypothesis

    Market structure and competitive conditions in the Arab GCC banking system

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    This paper investigates the market structure of Arab GCC banking industry during the years of 1993 to 2002 using the most frequently applied measures of concentration kbank concentration ratio (CRk) and Herfindahl-Hirschman Index (HHI) and evaluates the monopoly power of banks over the ten years period using the “H statistic” by Panzar and Rosse. The results show that Kuwait, Saudi Arabia and UAE have moderately concentrated markets and are moving to less concentrated positions. The measures of concentration also show that Qatar, Bahrain and Oman are highly concentrated markets. The Panzar-Rosse H-statistics suggest that banks in Kuwait, Saudi Arabia and the UAE operate under perfect competition; banks in Bahrain and Qatar operate under conditions of monopolistic competition; and we are unable to reject monopolistic competition for the banking market in Oman

    SMS spam filtering using probabilistic topic modelling and Stacked Denoising Autoencoder.

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    In This paper we present a novel approach to spam filtering and demonstrate its applicability with respect to SMS messages. Our approach requires minimum features engineering and a small set of labelled data samples. Features are extracted using topic modelling based on latent Dirichlet allocation, and then a comprehensive data model is created using a Stacked Denoising Autoencoder (SDA). Topic modelling summarises the data providing ease of use and high interpretability by visualising the topics using word clouds. Given that the SMS messages can be regarded as either spam (unwanted) or ham (wanted), the SDA is able to model the messages and accurately discriminate between the two classes without the need for a pre-labelled training set. The results are compared against the state-of-the-art spam detection algorithms with our proposed approach achieving over 97 % accuracy which compares favourably to the best reported algorithms presented in the literature

    Acceptability of novel lifelogging technology to determine context of sedentary behaviour in older adults

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    <strong>Objective:</strong> Lifelogging, using body worn sensors (activity monitors and time lapse photography) has the potential to shed light on the context of sedentary behaviour. The objectives of this study were to examine the acceptability, to older adults, of using lifelogging technology and indicate its usefulness for understanding behaviour.<strong> </strong><strong>Method:</strong> 6 older adults (4 males, mean age: 68yrs) wore the equipment (ActivPAL<sup>TM</sup> and Vicon Revue<sup>TM</sup>/SenseCam<sup>TM</sup>) for 7 consecutive days during free-living activity. The older adults’ perception of the lifelogging technology was assessed through semi-structured interviews, including a brief questionnaire (Likert scale), and reference to the researcher&#39;s diary. <strong>Results:</strong> Older adults in this study found the equipment acceptable to wear and it did not interfere with privacy, safety or create reactivity, but they reported problems with the actual technical functioning of the camera. <strong>Conclusion:</strong> This combination of sensors has good potential to provide lifelogging information on the context of sedentary behaviour

    Two-component Bose gas in an optical lattice at single-particle filling

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    The Bose-Hubbard model of a two-fold degenerate Bose gas is studied in an optical lattice with one particle per site and virtual tunneling to empty and doubly-occupied sites. An effective Hamiltonian for this system is derived within a continued-fraction approach. The ground state of the effective model is studied in mean-field approximation for a modulated optical lattice. A dimerized mean-field state gives a Mott insulator whereas the lattice without modulations develops long-range correlated phase fluctuations due to a Goldstone mode. This result is discussed in comparison with the superfluid and the Mott-insulating state of a single-component hard-core Bose.Comment: 11 page

    Skyrmions in a ferromagnetic Bose-Einstein condensate

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    The recently realized multicomponent Bose-Einstein condensates provide opportunities to explore the rich physics brought about by the spin degrees of freedom. For instance, we can study spin waves and phase separation, macroscopic quantum tunneling, Rabi oscillations, the coupling between spin gradients and superfluid flow, squeezed spin states, vortices and other topological excitations. Theoretically, there have been already some studies of the ground-state properties of these systems and their line-like vortex excitations. In analogy with nuclear physics or the quantum Hall effect, we explore here the possibility of observing point-like topological excitations or skyrmions. These are nontrivial spin textures that in principle can exist in a spinor Bose-Einstein condensate. In particular, we investigate the stability of skyrmions in a fictitious spin-1/2 condensate of Rb87 atoms. We find that skyrmions can exist in this case only as a metastable state, but with a lifetime of the order of, or even longer than, the typical lifetime of the condensate itself. In addition to determining the size and the lifetime of the skyrmion, we also present its spin texture and finally briefly consider its dynamical properties.Comment: 4 pages (REVtex), 3 PDF figures. See also cond-mat/000237

    The optimisation of a turbulent swirl nozzle using CFD

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    Swirl is imparted into free and impinging nozzle flows as well as jet flames to affect convective heat transfer, fluid mixing or flame stability. At the nozzle exit plane, the emerging flow strongly influences downstream flow development and so factors which impact upon the emitted flow are worthy of study. This paper presents preliminary CFD analyses into the effect of design parameters and operational settings on the emerging flow at the exit plane for a swirl nozzle (Remax~30,500). The research was conducted in the premanufacture stage to optimise the nozzle. Swirl is aerodynamically generated using multiple tangential ports located upstream of the exit plane and the streamwise flow is augmented with flow from two axial ports located at the nozzle base. Before reaching the exitplane, all flows pass through a contraction en route to a straight section of length (L). Factors studied in this paper include the angle of (inlet) tangential ports, the total length of the straight section (L), the ratio of axial-to-tangential inflows and the Reynolds number. Results show that larger tangential port angles and a shorter straight section help develop a modestly greate

    Analysis of customer profiles on an electrical distribution network

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    It has become increasingly important for electrical distribution companies to understand the drivers of demand. The maximum demand at any given substation can vary materially on an annual basis which means it is difficult to create a load related investment plan that is robust and stable. Currently, forecasts are based only on historical demand with little understanding about contributions to load profiles. In particular, the unique diversity of customers on any particular substation can affect load profile shape and future forecasts. Domestic and commercial customers can have very different behaviours generally and within these groups there is room for variation due to economic conditions and building types. This paper analyses customer types associated to substations on a distribution network by way of principal component analysis and identification of substations which deviate from the national demand trend. By examining the variance spread of this deviation, data points can be labelled in the principal component space. Groups of substations can then be categorised as having typical or atypical load profiles. This will support the need for further investigation into particular customer types and highlight the key factors of customer categorisation

    Effectiveness of technology transfer in the search for sustainable development : the case of Qatar

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    The Emir of Qatar firmly believes that security without development is not sustainable in the long run. Endorsed by Qatar’s top leadership, this conviction has spread contagiously to all corners of the public and private spheres, leading, in turn, numerous initiatives and massive investments directed at the development of the country. Sustainable development investments in Qatar are promising, but the process very slow amidst dynamic globalization. Technology capability is a key factor accelerating the growth of economic, social and environmental development. Hence, the aim of this dissertation is to assess the effectiveness of technology transfer in Qatar's search for sustainable development. The scope of the dissertation is confined to an analysis of certain government agencies involved in technology transfer; the government, the industry and R&D centres. The study developed a framework of measures to assess Qatari technology transfer and sustainable development, categorized into nine themes, including sustainable development, governance and internal environment, external technology resources, internal technology resource measures, absorptive capacity, value chain, value network, research and development and competitiveness. Through exploratory, descriptive and predictive research using qualitative and quantitative field surveys, along with secondary research, the study developed a framework of measures, and used it to assess the effectiveness of sustainability and technology transfer in Qatar. The study concluded that the technology transfer environment and practices in Qatar are ineffective in advancing the search for sustainable development. The study recommends the need to establish policies and priorities to facilitate sustainable development, focusing especially on technology, science and innovation. Future research should focus on in-depth case studies of specific industrial clusters as well as deepening the understanding of thematic measures of sustainability.EThOS - Electronic Theses Online ServiceGBUnited Kingdo
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