589 research outputs found

    Using clustering to extract personality information from socio economic data

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    It has become apparent that models that have been applied widely in economics, including Machine Learning techniques and Data Mining methods, should take into consideration principles that derive from the theories of Personality Psychology in order to discover more comprehensive knowledge regarding complicated economic behaviours. In this work, we present a method to extract Behavioural Groups by using simple clustering techniques that can potentially reveal aspects of the Personalities for their members. We believe that this is very important because the psychological information regarding the Personalities of individuals is limited in real world applications and because it can become a useful tool in improving the traditional models of Knowledge Economy

    A data mining framework to model consumer indebtedness with psychological factors

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    Modelling Consumer Indebtedness has proven to be a problem of complex nature. In this work we utilise Data Mining techniques and methods to explore the multifaceted aspect of Consumer Indebtedness by examining the contribution of Psychological Factors, like Impulsivity to the analysis of Consumer Debt. Our results confirm the beneficial impact of Psychological Factors in modelling Consumer Indebtedness and suggest a new approach in analysing Consumer Debt, that would take into consideration more Psychological characteristics of consumers and adopt techniques and practices from Data Mining

    A data mining framework to model consumer indebtedness with psychological factors

    Get PDF
    Modelling Consumer Indebtedness has proven to be a problem of complex nature. In this work we utilise Data Mining techniques and methods to explore the multifaceted aspect of Consumer Indebtedness by examining the contribution of Psychological Factors, like Impulsivity to the analysis of Consumer Debt. Our results confirm the beneficial impact of Psychological Factors in modelling Consumer Indebtedness and suggest a new approach in analysing Consumer Debt, that would take into consideration more Psychological characteristics of consumers and adopt techniques and practices from Data Mining

    Augmented neural networks for modelling consumer indebtness

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    Consumer Debt has risen to be an important problem of modern societies, generating a lot of research in order to understand the nature of consumer indebtness, which so far its modelling has been carried out by statistical models. In this work we show that Computational Intelligence can offer a more holistic approach that is more suitable for the complex relationships an indebtness dataset has and Linear Regression cannot uncover. In particular, as our results show, Neural Networks achieve the best performance in modelling consumer indebtness, especially when they manage to incorporate the significant and experimentally verified results of the Data Mining process in the model, exploiting the flexibility Neural Networks offer in designing their topology. This novel method forms an elaborate framework to model Consumer indebtness that can be extended to any other real world application

    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

    Metastasis rates and sites after treatment for choroidal melanoma by proton beam irradiation or by enucleation

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    Chryssanthi Koutsandrea, Marilita M Moschos, Michael Dimissianos, Gerasimos Georgopoulos, Ioannnis Ladas, Michael ApostolopoulosDepartment of Ophthalmology, Athens University, Athens, GreecePurpose: To investigate tumor thickness and location, the interval of time between treatment for choroidal melanoma (proton beam irradiation or enucleation) and diagnosis of metastatic disease, and rates and sites of metastasis.Design: Retrospective, interventional, noncomparative case series.Methods: Follow-up of 152 patients with primary choroidal melanoma, between 1992 and 2006 (14 years). One hundred and twenty-one patients were treated with proton beam irradiation and 31 patients were treated with enucleation. Baseline and annual or semiannual ophthalmic examination, B-scan ultrasonography, systemic and laboratory evaluations (liver enzymes, chest X-ray, ultrasonography or magnetic resonance imaging of the liver) were performed according to a standard protocol.Results: Nineteen patients (12.5%) were diagnosed with metastasis during follow-up time after treatment for choroidal melanoma. Thirteen patients (10.7%) of the irradiation group and 6 patients (19.3%) of the enucleation group were diagnosed with metastasis. Eight patients (6.6%) of the irradiation group and 5 patients (16.1%) of the enucleation group were diagnosed with liver metastasis. Ocular complications after proton beam irradiation were recorded. Fifty-nine patients (48.7%) of the irradiation group presented with cataract. Other complications were retinal detachment, retinopathy, vitreous haemorrhage, iris neovascularization, neovascular glaucoma, optic neuropathy, and corneal opacification.Conclusions: In our series, 10.7% of the irradiation group and 19.3% of the enucleation group were diagnosed with metastasis. The liver was the most common site of metastasis in both groups. Cataract was the most common complication in the irradiation group.Keywords: melanoma, metastasis, irradiation, enucleatio

    Skin rash associated with intravitreal bevacizumab in a patient with macular choroidal neovascularization

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    Ioannis D Ladas, Marilita M Moschos, Thanos D Papakostas, Athanasios I Kotsolis, Ilias Georgalas, Michail ApostolopoulosDepartment of Ophthalmology, &amp;ldquo;G. Gennimatas&amp;rdquo; Hospital of Athens, University of Athens, Athens, GreecePurpose: The purpose of this observational case report is to describe a case of skin rash after intravitreal use of bevacizumab.Methods: A 50-year-old man with choroidal neovascularization in the right eye due to age-related macular degeneration was treated with three intravitreal injections of bevacizumab.Results: Twelve days after the first injection, the patient developed a maculopapular rash on his forehead and on both temporal regions around his eyes. The rash disappeared eight days after treatment with topical corticosteroids. A skin rash with the same distribution reappeared 14 days after the second and 10 days after the third injection. Similarly, it disappeared five and seven days after the use of the same treatment. The follow-up period was 15 months after the third injection. During the follow-up period the rash did not reappear.Conclusion: This case report may initiate further investigation of similar cases to support this observation, as there are a lack of reports of skin rash after intravitreal administration of bevacizumab.Keywords: skin rash, bevacizumab, age-related macular degeneratio

    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
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