On the Hardware Implementation of Triangle Traversal Algorithms for Graphics Processing

Current GPU architectures provide impressive processing rates in graphical applications because of their specialized graphics pipeline. However, little attention has been paid to the analysis and study of different hardware architectures to implement specific pipeline stages. In this work we have identified one of the key stages in the graphics pipeline, the triangle traversal procedure, and we have implemented three different algorithms in hardware: bounding-box, zig-zag and Hilbert curve-based. The experimental results show that important area-performance trade-offs can be met when implementing key image processing algorithms in hardwar

Social security and platform work:Towards a more transparent and inclusive path

Social security systems in Western Europe have been traditionally designed around the concept of the standard employment relationship, which may be defined as a “stable, open-ended and direct arrangement between a dependent, full-time employee and their unitary employer”. Non-standard forms of work, in turn, have been mostly considered part of the private ‘social security’ sphere (i.e. the family or other private income support in case of informal work or commercial relationships), and thus left generally uncovered by public labour-related social security schemes. Among all forms of non-standard work, there is one which features diverge the most from those of the standard employment relationship (and which hence may challenge social security systems at national and EU level the most): platform work. Platform work consists in the performance, in exchange for income, of on-demand short term tasks for different persons or companies by a person selected online from a pool of workers through the intermediation of an online platform. In recent years, many academics, social partners and public officials have wondered whether and in which way platform work’s unique features may challenge social security systems. Taking into account these concerns, this thesis examines the question of what is the social security position of platform workers under the law of the EU and of selected EU countries, and how that position compares to the one of persons performing work under a standard employment relationship. At EU level, the thesis analyses the application of the EU rules for the coordination of social security, the Regulation 492/2011 and the Directive 2004/38/EC to situations of platform work. The thesis also analyses the most recent (and, arguably, most significant) effort by the EU to promote some basic minimum standards concerning the social protection of non standard workers across the EU Member States, namely the Council Recommendation on access to social protection for workers and the self employed. The thesis demonstrates that platform workers often experience differences in their social security position when compared to the social security position of persons performing work in a standard employment relationship. In this regard, the thesis identifies significant challenges in determining the employment status of platform workers, as well as other aspects that are key for their social security position (such as how many hours or days of work they perform, or in which country their employer is located). The thesis also notes many instances in which platform workers may be excluded from formal, effective and/or adequate social security coverage due to the inherent features of platform work (such as its fragmented character and flexibility). The thesis then relies on the abovementioned Council Recommendation and other instruments of EU law in order to determine the two social security principles that best address these differences and challenges on the social security position of platform workers, namely transparency (understood as both ‘clarity’ and ‘legal certainty’) and inclusion. The thesis ends by proposing several recommendations that may better ensure that these principles are respected as it regards platform work, such as the use, for social security purposes, of a broad concept of work that fully encompasses platform work, as well as the adaptation to the specific features of platform work of the requirements for entitlement to social security benefits

The changing concept of work:When does typical work become atypical

In most countries, a standard (or core) model of employment relationship (i.e. full-time work under an open-ended employment contract) typically receives the greatest labour and social security protection, with divergent work arrangements receiving less protection in correlation to the magnitude of the differences between the former and the latter. However, recent developments concerning non-standard forms of work may question this dynamic. In this article, we examine the nature and current evolution of the standard employment relationship, then analyse how other forms of work deviate from this standard. In order to do so, we draw on the conclusions of the numerous studies recently published by scholars and international organisations in the wake of the growing public debate on the ‘new world of work’. Afterwards, we analyse the situation of non-standard workers under certain social security systems, in order to determine how those systems have approached the divergent character of these forms of work. This leads us to identify the main challenges that social security systems experience when faced with non-standard forms of work. The article concludes by addressing the need to adapt the basic principles of social security to the atypical features of non-standard work

Regularity of center-outward distribution functions in non-convex domains

For a probability P in $R^d$ its center outward distribution function $F_{\pm}$, introduced in Chernozhukov et al. (2017) and Hallin et al. (2021), is a new and successful concept of multivariate distribution function based on mass transportation theory. This work proves, for a probability P with density locally bounded away from zero and infinity in its support, the continuity of the center-outward map on the interior of the support of P and the continuity of its inverse, the quantile, $Q_{\pm}$. This relaxes the convexity assumption in del Barrio et al. (2020). Some important consequences of this continuity are Glivenko-Cantelli type theorems and characterisation of weak convergence by the stability of the center-outward map

Analytic model of a cache-only memory architecture

An approximate analytic model of a shared memory multiprocessor with a Cache Only Memory Architecture (COMA), the busbased Data Difussion Machine (DDM), is presented and validated. It describes the timing and interference in the system as a function of the hardware, the protocols, the topology and the workload. Model results have been compared to results from an independent simulator. The comparison shows good model accuracy specially for non-saturated systems, where the errors in response times and device utilizations are independent of the number of processors and remain below 10% in 90% of the simulations. Therefore, the model can be used as an average performance prediction tool that avoids expensive simulations in the design of systems with many processors

La Directiva de Género y su impacto en el sector asegurador

El objetivo principal de este trabajo es determinar el mejor método para calcular la prima de los seguros de vida, de tal forma que se minimice el precio del seguro pero manteniendo la estabilidad de la entidad aseguradora. Para ello se revisa la denominada “Directiva de Género” y las Directrices sobre su aplicación. Se concluye que la utilización de las tablas unisex, aunque estén ponderadas, no es un buen método porque su resultado difiere de los obtenidos con el método basado en el promedio de las primas calculadas con tablas individualizadas. Este último se considera más correcto desde el punto de vista actuarial, porque la prima calculada de esta forma permite asegurar la estabilidad de la empresa, al garantizar que las reservas son suficientes para hacer frente a los compromisos futuros del asegurador. Se obtienen los resultados particulares para un Seguro de Vida Entera y para un Seguro de Renta Vitalicia

Four-injector variability modeling of FinFET predictive technology models

The usual way of modeling variability using threshold voltage shift and drain current amplification is becoming inaccurate as new sources of variability appear in sub-22nm devices. In this work we apply the four-injector approach for variability modeling to the simulation of SRAMs with predictive technology models from 20nm down to 7nm nodes. We show that the SRAMs, designed following ITRS roadmap, present stability metrics higher by at least 20% compared to a classical variability modeling approach. Speed estimation is also pessimistic, whereas leakage is underestimated if sub-threshold slope and DIBL mismatch and their correlations with threshold voltage are not considered

Area-Efficient Linear Regression Architecture for Real-Time Signal Processing on FPGAs

Linear regression is a technique widely used in digital signal processing. It consists on finding the linear function that better fits a given set of samples. This paper proposes different hardware architectures for the implementation of the linear regression method on FPGAs, specially targeting area restrictive systems. It saves area at the cost of constraining the lengths of the input signal to some fixed values. We have implemented the proposed scheme in an Automatic Modulation Classifier, meeting the hard real-time constraints this kind of systems have