Applying FRAM to the construction of concrete frame structures

So far the FRAM has been applied to different sectors of high risk and complexity such as aviation, including air traffic control, health care, nuclear power plants, chemical and petrochemical industry, railways, maritime sector... obtaining very positive results, which have led to an improvement in safety management in them. However, its application to the construction sector has not yet been developed in depth. In the European Union, the construction sector is the sector with the highest number of accidents, so safety in construction is a priority. Structures construction is one of the most hazardous construction phases or activities. For this reason, the project "Composite Leading Indicators for the improvement of the resilience of occupational safety, in the activities of design and execution of structures" (BIA2016-79270-P) aims to improve the management and monitoring of occupational safety in these activities using novel vision of Safety II developed by the Resilience Engineering. In this way, the FRAM approach has been applied to know the work-as-done, that is, to identify the adjustments and variability of daily performance. For this purpose, observations and interviews at the place of work have been carried out. With the information collected and the help of the FRAM Model Visualiser (FMV) the functions of the FRAM model have been defined. Thus, the FRAM analysis for the construction of concrete frame structures is presented. Based on these results, leading indicators will be designed to monitor and control these activities adequately in the next phase of the project.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech.We wish to thank the Spanish Ministry of Economy and Competitiveness for financing the project BIA2016-79270-P, of which this study is part. It is also important to acknowledge the Ministry of Education, Culture and Sports of the Government of Spain for it support through the predoctoral program (FPU 2016/03298)

Redistribution and fiscal policy

This paper studies the optimal behavior of a democratic government in its use of fiscal policies to redistribute income. I present a stochastic dynamic general equilibrium model with heterogeneous agents to analyze (1) the differences between the effects on the optimal tax rate of permanent and nonpermanent perturbations and (2) the relationship between initial inequality and both steady-state levy and income distribution. In addition, the optimal fiscal policy for the transition is calculated. The analysis leads me to three main conclusions. First, there are no important differences between how taxes respond to a permanent or nonpermanent perturbation. Second, the initial inequality has a huge effect on both actual levy and actual income distribution. And finally, the Chari, Christiano, and Kehoe (1992) result, i.e., taxes on labor are roughly constant over the business cycle, holds only if the productivity ratio is constant. In addition, the model implies a positive correlation between inequality and tax rate, just as in the basic literature.Taxation ; Income distribution

Development and implementation of an adaptive digital beamforming network for satellite communication systems

The use of adaptive digital beamforming techniques has, until recently, been largely restricted to high performance military radar systems. Recent advances in digital technology, however, have enabled the design of single chip digital beamforming networks. This, coupled with advances in digital signal processor technology, enables complete beamforming systems to be constructed at a lower cost, thus making the application of these techniques to commercial communications systems attractive. The design and development of such an adaptative digital beamforming network are described. The system is being developed as a proof of concept laboratory based demonstrator to enable the feasibility of adaptive digital beamforming techniques for communication systems to be determined. Ultimately, digital beamforming could be used in conjunction with large array antennas for communication satellite systems. This will enable the simultaneous steering of high gain antenna beams in the direction of gr...Peer ReviewedPostprint (published version

Beamforming and Multiuser Detection in CDMA Systems with External Interferences

Multiuser detection has been investigated to mitigate the near-far effect in CDMA systems. Antenna arrays have been shown to provide spatial diversity and cancel undesired signals. In this paper we consider the synergy of both multiuser detection and antenna arrays for the base station of a CDMA system. The receiver we proposed consists of the known multiuser decorrelator, which cancels multiple-access interferences followed by a beamformer for each user, which cancels the external interferences. This receiver adds an extra branch to the decorrelator. This additional branch, corresponding to a fictitious user with an unused code and zero power, allows to estimate the external interference signal subspace and compute a suitable beamforming weight-vector that cancels the external interferences. The receiver is also extended to the asynchronous case and all of this without any training signal or any a priori spatial information.Peer ReviewedPostprint (published version

Multipath and interference errors reduction in gps using antenna arrays

The Global Positioning System (GPS) is a worldwide satellite based positioning system that provides any user with tridimensional position, speed and time information. The measured pseudorange is affected by the multipath propagation, which probably is the major source of errors for high precision systems. After a presentation of the GPS and the basic techniques employed to perform pseudorange measurements, the influence of the multipath components on the pseudorange measurement is explained. Like every system the GPS is also exposed to the errors that can be caused by the interferences, and a lot of civil applications need robust receivers to interferences for reasons of safety. In this paper some signal array processing techniques for reducing the code measurement errors due to the multipath propagation and the interferences are presented. Firstly, a non-adaptive beamforming is used. Secondly, a variant of the MUSIC and the maximum likelihood estimator can be used to estimate the DOA of the reflections and the interferences, and then a weight vector that removes these signals is calculated. In the third place, a beamforming with temporal reference is presented; the reference is not the GPS signal itself, but the output of a matched filter to the code. An interesting feature of the proposed techniques is that they can be applied to an array of arbitrary geometry.Peer ReviewedPostprint (published version