437 research outputs found

    Value relevance of accounting information in the pre- and post-IFRS accounting periods

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    This paper examines the value relevance of accounting information in the pre- and post-periods of International Financial Reporting Standards implementation using the models of Easton and Harris (1991) and Feltham and Ohlson (1995) for a sample of Greek companies. The results of the paper indicate that the effects of the IFRS reduced the incremental information content of book values of equity for stock prices. However, earnings’ incremental information content increased for the post-IFRS period. The results can be explained by the introduction of the fair value principle under the IFRS that brought major changes in book value but not in earnings.peer-reviewe

    The evolution problem for the 1D nonlocal Fisher-KPP equation with a top hat kernel. Part 1. The Cauchy problem on the real line

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    We study the Cauchy problem on the real line for the nonlocal Fisher-KPP equation in one spatial dimension, ut=Duxx+u(1ϕu), u_t = D u_{xx} + u(1-\phi*u), where ϕu\phi*u is a spatial convolution with the top hat kernel, ϕ(y)H(14y2)\phi(y) \equiv H\left(\frac{1}{4}-y^2\right). After showing that the problem is globally well-posed, we demonstrate that positive, spatially-periodic solutions bifurcate from the spatially-uniform steady state solution u=1u=1 as the diffusivity, DD, decreases through Δ10.00297\Delta_1 \approx 0.00297. We explicitly construct these spatially-periodic solutions as uniformly-valid asymptotic approximations for D1D \ll 1, over one wavelength, via the method of matched asymptotic expansions. These consist, at leading order, of regularly-spaced, compactly-supported regions with width of O(1)O(1) where u=O(1)u=O(1), separated by regions where uu is exponentially small at leading order as D0+D \to 0^+. From numerical solutions, we find that for DΔ1D \geq \Delta_1, permanent form travelling waves, with minimum wavespeed, 2D2 \sqrt{D}, are generated, whilst for 0<D<Δ10 < D < \Delta_1, the wavefronts generated separate the regions where u=0u=0 from a region where a steady periodic solution is created. The structure of these transitional travelling waves is examined in some detail

    Robust Device-to-Device 5G cellular communication in the post-disaster scenario

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    The wireless communication is an integral part of the society, however, wireless network infrastructure may not fully function during post-disaster wireless network scenario in which we need wireless services even more than normal circumstances. In such post-disaster scenarios, the base stations (BS) could possibly be dysfunctional or overloaded by an excessive number of user calls or data, whereas user terminals are likely to be partially connected to or fully isolated from the BS radio signals. In this paper, we study the network behavior during the post-disaster when BSs undergo the thinning process due to the damage to the network infrastructure. During network recovery phase, we also study the network performance when new temporary BSs are distributed which will bring the network into BS superposition phase. Furthermore, Device-to-Device (D2D) assisted cellular communication helps to increase the link level network connectivity which is highly appreciated during postdisaster network scenario because the network coverage is more desirable than the network throughout in such cases. We also present the analytical study of D2D and cellular communication and show that it will effectively increase the network coverage which may ultimately save many lives during the golden hours of post-disaster phase

    The Cauchy problem for a class of two-dimensional nonlocal nonlinear wave equations governing anti-plane shear motions in elastic materials

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    This paper is concerned with the analysis of the Cauchy problem of a general class of two-dimensional nonlinear nonlocal wave equations governing anti-plane shear motions in nonlocal elasticity. The nonlocal nature of the problem is reflected by a convolution integral in the space variables. The Fourier transform of the convolution kernel is nonnegative and satisfies a certain growth condition at infinity. For initial data in L2L^{2} Sobolev spaces, conditions for global existence or finite time blow-up of the solutions of the Cauchy problem are established.Comment: 15 pages. "Section 6 The Anisotropic Case" added and minor changes. Accepted for publication in Nonlinearit

    In search of the origins and enduring impact of agile software development

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    The Agile Manifesto is a philosophical touchpoint for all agile software development (ASD) methods. We examine the manifesto and some of its associated agile methods in an effort to identify the major impacts of ASD. We have encountered some difficulty in delineating agile and non-agile software processes, which is partially the result of terminological confusion. It is clear from the volume of published research that ASD has made a significant contribution, and we have identified two lasting and important impacts. Firstly, the reduction in iteration durations and secondly, the push for reduced levels of documentation (especially in relation to software requirements). Other aspects of the Agile Manifesto may not have exerted a significant impact; for example, the use of tooling to automate processes has become central to continuous software engineering (CSE) and may not be wholly congruent with the manifesto. Furthermore, many organisations may still rely on business contracts despite calls in the manifesto for greater levels of informal customer collaboration

    An overview of post-disaster emergency communication systems in the future networks

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    The emerging 5G communication network is gaining tremendous attention from mobile network operators, regulators, and academia due to the provisions of network densification, ultra-low latency and improved spectral and energy efficiencies. However, post-disaster EMS, which nowadays predominantly depends on the wireless communication infrastructure, is significantly lagging behind in terms of innovation, standards, and investments. Since the 5G vision is the revolution of the telecommunication industry, provisions of efficiently handling EMS is expected to be distributed, autonomous, and resilient to the network vulnerabilities due to both man-made and natural disasters. In this article, the 4G LTE approaches for typical post-disaster communication and their shortcomings will be discussed. We elaborate three typical post-disaster network scenarios when the network is congested, partly functional or completely isolated. The possible solution framework, for instance, Device-to-Device communication, drone-assisted communication, mobile ad hoc networks and Internet-of-Things, for post-disaster scenarios will be discussed. Given that spectrum allocation is critical for EMS, we assess the possible schemes for radio resource allocation specific for EMS in addition to the social responsibility of users in such critical situations

    Testing limits to airflow perturbation device (APD) measurements

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    <p>Abstract</p> <p>Background</p> <p>The Airflow Perturbation Device (APD) is a lightweight, portable device that can be used to measure total respiratory resistance as well as inhalation and exhalation resistances. There is a need to determine limits to the accuracy of APD measurements for different conditions likely to occur: leaks around the mouthpiece, use of an oronasal mask, and the addition of resistance in the respiratory system. Also, there is a need for resistance measurements in patients who are ventilated.</p> <p>Method</p> <p>Ten subjects between the ages of 18 and 35 were tested for each station in the experiment. The first station involved testing the effects of leaks of known sizes on APD measurements. The second station tested the use of an oronasal mask used in conjunction with the APD during nose and mouth breathing. The third station tested the effects of two different resistances added in series with the APD mouthpiece. The fourth station tested the usage of a flexible ventilator tube in conjunction with the APD.</p> <p>Results</p> <p>All leaks reduced APD resistance measurement values. Leaks represented by two 3.2 mm diameter tubes reduced measured resistance by about 10% (4.2 cmH<sub>2</sub>O·sec/L for control and 3.9 cm H<sub>2</sub>O·sec/L for the leak). This was not statistically significant. Larger leaks given by 4.8 and 6.4 mm tubes reduced measurements significantly (3.4 and 3.0 cm cmH<sub>2</sub>O·sec/L, respectively). Mouth resistance measured with a cardboard mouthpiece gave an APD measurement of 4.2 cm H<sub>2</sub>O·sec/L and mouth resistance measured with an oronasal mask was 4.5 cm H<sub>2</sub>O·sec/L; the two were not significantly different. Nose resistance measured with the oronasal mask was 7.6 cm H<sub>2</sub>O·sec/L. Adding airflow resistances of 1.12 and 2.10 cm H<sub>2</sub>O·sec/L to the breathing circuit between the mouth and APD yielded respiratory resistance values higher than the control by 0.7 and 2.0 cm H<sub>2</sub>O·sec/L. Although breathing through a 52 cm length of flexible ventilator tubing reduced the APD measurement from 4.0 cm H<sub>2</sub>O·sec/L for the control to 3.6 cm H<sub>2</sub>O·sec/L for the tube, the difference was not statistically significant.</p> <p>Conclusion</p> <p>The APD can be adapted for use in ventilated, unconscious, and uncooperative patients with use of a ventilator tube and an oronasal mask without significantly affecting measurements. Adding a resistance in series with the APD mouthpiece has an additive effect on resistance measurements, and can be used for qualitative calibration. A leak size of at least the equivalent of two 3.2 mm diameter tubes can be tolerated without significantly affecting APD measurements.</p
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