1,562 research outputs found

    Constellation Design of Geosynchronous Navigation Satellites Which Maximizes Availability and Accuracy over a Specified Region of the Earth

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    Currently, there are four Global Navigation Satellite Systems (GNSS) either being developed or in existence-GPS, GLONASS, Compass, and Galileo. Additionally, there are several Regional Navigation Satellite Systems (RNSS) planned or in existence, as well as numerous augmentation systems (which require a GNSS for operation). It can be anticipated that there will be interest in developing additional independent regional navigation satellite systems to cover areas of interest to particular countries or regions, who want to have their own system. In this paper, a genetic algorithm is used in an effort to determine near-optimal RNSS constellations. First, a cost function is setup, which involves a weighted combination of dilution of precision (DOP) values and percentage availability for any number of receiver locations on the ground (which themselves can be weighted). Effectively, using this approach it is easy to quantify the quality of coverage, in terms of measurement geometry, over a specific region of the earth. Next, a genetic algorithm is used in order to attempt to converge to the lowest-cost constellation possible

    Is There an Informal Employment Wage Penalty in Egypt?

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    This paper considers the private sector wage earners in Egypt and examine their wage distribution during 1998-2012 using Egyptian Labor Market Panel Survey. We first estimate Mincer wage equations both at the mean and at different quantiles of the wage distribution taking into account observable characteristics. Then we make use of the panel feature of the data and estimate models taking into account unobservable characteristics. We also consider the possibility of nonlinearity in covariate effects and estimate a variant of matching models. In all cases we find a persistent informal wage penalty in the face of extensive sensitivity checks. It is smaller when unobserved heterogeneity is taken into account and larger at the top than at the bottom of the conditional wage distribution. We also examine the informal wage penalty over time during the study period and in different groups according to experience and education. The informal wage penalty has increased recently over time and is larger for the better educated but smaller for the more experienced

    IS THERE AN INFORMAL EMPLOYMENT WAGE PENALTY IN EGYPT?

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    This paper considers the private sector wage earners in Egypt and examine their wage distribution during 1998-2012 using Egyptian Labor Market Panel Survey. We first estimate Mincer wage equations both at the mean and at different quantiles of the wage distribution taking into account observable characteristics. Then we make use of the panel feature of the data and estimate models taking into account unobservable characteristics. We also consider the possibility of nonlinearity in covariate effects and estimate a variant of matching models. In all cases we find a persistent informal wage penalty in the face of extensive sensitivity checks. It is smaller when unobserved heterogeneity is taken into account and larger at the top than at the bottom of the conditional wage distribution. We also examine the informal wage penalty over time during the study period and in different groups according to experience and education. The informal wage penalty has increased recently over time and is larger for the better educated but smaller for the more experienced

    Is There an Informal Employment Wage Penalty in Egypt?

    Get PDF
    This paper considers the private sector wage earners in Egypt and examine their wage distribution during 1998-2012 using Egyptian Labor Market Panel Survey. We first estimate Mincer wage equations both at the mean and at different quantiles of the wage distribution taking into account observable characteristics. Then we make use of the panel feature of the data and estimate models taking into account unobservable characteristics. We also consider the possibility of nonlinearity in covariate effects and estimate a variant of matching models. In all cases we find a persistent informal wage penalty in the face of extensive sensitivity checks. It is smaller when unobserved heterogeneity is taken into account and larger at the top than at the bottom of the conditional wage distribution. We also examine the informal wage penalty over time during the study period and in different groups according to experience and education. The informal wage penalty has increased recently over time and is larger for the better educated but smaller for the more experienced

    Public versus Private Sector Wage Gap in Egypt: Evidence from Quantile Regression on Panel Data

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    This paper considers the public and private sector wage earners in Egypt and examines their wage distribution during 1998-2012 using Egyptian Labor Market Panel Survey. We estimate the public-private sector wage gap with Mincer wage equations both at the mean and at different quantiles of the wage distribution. In this process we take into account observable and unobservable characteristics of the individuals using the panel feature of the data with a fixed effects model. We address sector of employment selection issue for both males and females. We find that there is very little evidence of sample selection in our data. Therefore, we present both the selection corrected results and the results with no selection correction. We find a persistent public sector wage penalty for males and public sector wage premium for females in the face of extensive sensitivity checks. They are larger when unobserved heterogeneity is taken into account for males but insignificant for females. They are similar across the quantiles for males but, smaller at the top than at the bottom of the conditional wage distribution for females. We further examine the public sector wage gap over time and in different sub-groups according to age and education. The public sector wage penalty for males has decreased recently over time and is larger for the better educated and younger. We also find substantial regional differences in public sector wage gap for males

    Is There an Informal Employment Wage Penalty in Egypt?

    Get PDF
    This paper considers the private sector wage earners in Egypt and examine their wage distribution during 1998-2012 using Egyptian Labor Market Panel Survey. We first estimate Mincer wage equations both at the mean and at different quantiles of the wage distribution taking into account observable characteristics. Then we make use of the panel feature of the data and estimate models taking into account unobservable characteristics. We also consider the possibility of nonlinearity in covariate effects and estimate a variant of matching models. In all cases we find a persistent informal wage penalty in the face of extensive sensitivity checks. It is smaller when unobserved heterogeneity is taken into account and larger at the top than at the bottom of the conditional wage distribution. We also examine the informal wage penalty over time during the study period and in different groups according to experience and education. The informal wage penalty has increased recently over time and is larger for the better educated but smaller for the more experienced

    Optimasi Portofolio Resiko Menggunakan Model Markowitz MVO Dikaitkan dengan Keterbatasan Manusia dalam Memprediksi Masa Depan dalam Perspektif Al-Qur`an

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    Risk portfolio on modern finance has become increasingly technical, requiring the use of sophisticated mathematical tools in both research and practice. Since companies cannot insure themselves completely against risk, as human incompetence in predicting the future precisely that written in Al-Quran surah Luqman verse 34, they have to manage it to yield an optimal portfolio. The objective here is to minimize the variance among all portfolios, or alternatively, to maximize expected return among all portfolios that has at least a certain expected return. Furthermore, this study focuses on optimizing risk portfolio so called Markowitz MVO (Mean-Variance Optimization). Some theoretical frameworks for analysis are arithmetic mean, geometric mean, variance, covariance, linear programming, and quadratic programming. Moreover, finding a minimum variance portfolio produces a convex quadratic programming, that is minimizing the objective function ðð¥with constraintsð ð 𥠥 ðandð´ð¥ = ð. The outcome of this research is the solution of optimal risk portofolio in some investments that could be finished smoothly using MATLAB R2007b software together with its graphic analysis

    Search for heavy resonances decaying to two Higgs bosons in final states containing four b quarks

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    A search is presented for narrow heavy resonances X decaying into pairs of Higgs bosons (H) in proton-proton collisions collected by the CMS experiment at the LHC at root s = 8 TeV. The data correspond to an integrated luminosity of 19.7 fb(-1). The search considers HH resonances with masses between 1 and 3 TeV, having final states of two b quark pairs. Each Higgs boson is produced with large momentum, and the hadronization products of the pair of b quarks can usually be reconstructed as single large jets. The background from multijet and t (t) over bar events is significantly reduced by applying requirements related to the flavor of the jet, its mass, and its substructure. The signal would be identified as a peak on top of the dijet invariant mass spectrum of the remaining background events. No evidence is observed for such a signal. Upper limits obtained at 95 confidence level for the product of the production cross section and branching fraction sigma(gg -> X) B(X -> HH -> b (b) over barb (b) over bar) range from 10 to 1.5 fb for the mass of X from 1.15 to 2.0 TeV, significantly extending previous searches. For a warped extra dimension theory with amass scale Lambda(R) = 1 TeV, the data exclude radion scalar masses between 1.15 and 1.55 TeV
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