Distributed power allocation for D2D communications underlaying/overlaying OFDMA cellular networks

The implementation of device-to-device (D2D) underlaying or overlaying pre-existing cellular networks has received much attention due to the potential of enhancing the total cell throughput, reducing power consumption and increasing the instantaneous data rate. In this paper we propose a distributed power allocation scheme for D2D OFDMA communications and, in particular, we consider the two operating modes amenable to a distributed implementation: dedicated and reuse modes. The proposed schemes address the problem of maximizing the users' sum rate subject to power constraints, which is known to be nonconvex and, as such, extremely difficult to be solved exactly. We propose here a fresh approach to this well-known problem, capitalizing on the fact that the power allocation problem can be modeled as a potential game. Exploiting the potential games property of converging under better response dynamics, we propose two fully distributed iterative algorithms, one for each operation mode considered, where each user updates sequentially and autonomously its power allocation. Numerical results, computed for several different user scenarios, show that the proposed methods, which converge to one of the local maxima of the objective function, exhibit performance close to the maximum achievable optimum and outperform other schemes presented in the literature

Biological Gender Differences, Absenteeism and the Earning Gap

In most Western countries illness-related absenteeism is higher among female workers than among male workers. Using the personnel dataset of a large Italian bank, we show that the probability of an absence due to illness increases for females, relative to males, approximately 28 days after a previous illness. This difference disappears for workers age 45 or older. We interpret this as evidence that the menstrual cycle raises female absenteeism. Absences with a 28-day cycle explain a significant fraction of the male-female absenteeism gap. To investigate the effect of absenteeism on earnings, we use a simple signaling model in which employers cannot directly observe workers' productivity, and therefore use observable characteristics %u2013 including absenteeism %u2013 to set wages. Since men are absent from work because of health and shirking reasons, while women face an additional exogenous source of health shocks due to menstruation, the signal extraction based on absenteeism is more informative about shirking for males than for females. Consistent with the predictions of the model, we find that the relationship between earnings and absenteeism is more negative for males than for females. Furthermore, this difference declines with seniority, as employers learn more about their workers' true productivity. Finally, we calculate the earnings cost for women associated with menstruation. We find that higher absenteeism induced by the 28-day cycle explains 11.8 percent of the earnings gender differential.

Message passing resource allocation for the uplink of multicarrier systems

We propose a novel distributed resource allocation scheme for the up-link of a cellular multi-carrier system based on the message passing (MP) algorithm. In the proposed approach each transmitter iteratively sends and receives information messages to/from the base station with the goal of achieving an optimal resource allocation strategy. The exchanged messages are the solution of small distributed allocation problems. To reduce the computational load, the MP problems at the terminals follow a dynamic programming formulation. The advantage of the proposed scheme is that it distributes the computational effort among all the transmitters in the cell and it does not require the presence of a central controller that takes all the decisions. Numerical results show that the proposed approach is an excellent solution to the resource allocation problem for cellular multi-carrier systems.Comment: 6 pages, 4 figure

The Political Economy of Intergenerational Income Mobility

The intergenerational elasticity of income is considered one of the best measures of the degree to which a society gives equal opportunity to its members. While much research has been devoted to measuring this reduced-form parameter, less is known about its underlying structural determinants. Using a model with exogenous talent endowments, endogenous parental investment in children and endogenous redistributive institutions, we identify the structural parameters that govern the intergenerational elasticity of income. The model clarifies how the interaction between private and collective decisions determines the equilibrium level of social mobility. Two societies with similar economic and biological fundamentals may have vastly different degrees of intergenerational mobility depending on their political institutions. We offer empirical evidence in line with the predictions of the model. We conclude that international comparisons of intergenerational elasticity of income are not particularly informative about fairness without taking into account differences in politico-economic institutions.public education, intergenerational mobility, political institutions

Leading advertisers efficiency evaluated by data envelopment analysis

In this paper we analyze the problem of measuring the advertising efficiency of the Leading US Advertisers during the period 2001-2006. We use the DEA (Data Envelopment Analysis) approach that enables to evaluate the relative efficiency in case of multiple inputs and outputs. In particular, the classical CCR-DEA model is first implemented in each year considered; a windows analysis approach is then used in order to better capture the dynamics of efficiency. Finally, the effect on efficiency of advertising spending over time, is captured by Adstock as an additional variable of the DEA model. The dynamics of Adstock is described by a finite difference equation.

Transverse momentum dependent multiplicities of hadrons produced in DIS at COMPASS

1noThe COMPASS Collaboration measured the transverse momentum dependent multiplicities of charged hadrons produced in Deep Inelastic Scattering (DIS) off unpolarized protons. Complementing previous COMPASS measurements obtained with an isoscalar target, the data have been collected in 2016 and 2017 with 160 GeV/c muon beams and a liquid hydrogen target. The multiplicities are studied as a function of the square of the hadron transverse momentum with respect to the virtual photon direction P2hT in bins of the Bjorken variable x, of the photon virtuality Q2 and of the fraction z of the photon energy carried by the hadron. Preliminary results of this analysis, performed on a fraction of the available data sample, are shown here for the first time.openopenAndrea MorettiMoretti, Andre

Low Complexity WMMSE Power Allocation In NOMA-FD Systems

In this paper we study the problem of power and channel allocation with the objective of maximizing the system sum-rate for multicarrier non-orthogonal multiple access (NOMA) full duplex (FD) systems. Such an allocation problem is non-convex and, thus, with the goal of designing a low complexity solution, we propose a scheme based on the minimization of the weighted mean square error, which achieves performance reasonably close to the optimum and allows to clearly outperforms a conventional orthogonal multiple access approach. Numerical results assess the effectiveness of our algorithm.Comment: 5 pages conference paper, 3 figures. Submitted on ICASSP 202

Generalized voter-like models on heterogeneous networks

We describe a generalization of the voter model on complex networks that encompasses different sources of degree-related heterogeneity and that is amenable to direct analytical solution by applying the standard methods of heterogeneous mean-field theory. Our formalism allows for a compact description of previously proposed heterogeneous voter-like models, and represents a basic framework within which we can rationalize the effects of heterogeneity in voter-like models, as well as implement novel sources of heterogeneity, not previously considered in the literature