Normalizing or not normalizing? An open question for floating-point arithmetic in embedded systems

Emerging embedded applications lack of a specific standard when they require floating-point arithmetic. In this situation they use the IEEE-754 standard or ad hoc variations of it. However, this standard was not designed for this purpose. This paper aims to open a debate to define a new extension of the standard to cover embedded applications. In this work, we only focus on the impact of not performing normalization. We show how eliminating the condition of normalized numbers, implementation costs can be dramatically reduced, at the expense of a moderate loss of accuracy. Several architectures to implement addition and multiplication for non-normalized numbers are proposed and analyzed. We show that a combined architecture (adder-multiplier) can halve the area and power consumption of its counterpart IEEE-754 architecture. This saving comes at the cost of reducing an average of about 10 dBs the Signal-to-Noise Ratio for the tested algorithms. We think these results should encourage researchers to perform further investigation in this issue.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

CTPATH: Development of an iOS application to compute ecological routes

El cambio climático se debe en gran parte a la emisión de gases de efecto invernadero como el dióxido de carbono, por tanto, es necesario desarrollar nuevas tecnologías que reduzcan la emisión de estos gases a la atmósfera. Actualmente, las aplicaciones para calcular rutas no tienen en cuenta la relación entre el tiempo de viaje y las emisiones, ni el perfil de conducción del usuario y el tipo de coche. El proyecto CTPATH tiene en cuenta estos factores. CTPATH para iOS tiene como objetivo reducir la cantidad de gases de efecto invernadero que emiten los vehículos cuyo combustible es un derivado del petr ´oleo mediante el uso de rutas más ecológicas. Cualquier usuario puede utilizar la aplicaci ´on sin necesidad de registrarse, aunque si lo desea, podrá hacerlo a través de la aplicación web existente. Registrarse en la aplicación ayuda a calcular cuál es la ruta que mejor se adapta a su forma de conducir y por tanto, ofrecer una mejor experiencia al usuario. Cuando el usuario introduce el punto de inicio y el punto de destino se le muestra una lista de tres posibles rutas a tomar, donde la más ecológica aparece en primer lugar, seguido de otras rutas alternativas que son menos ecológicas y posiblemente más rápidas que la primera. Puede darse el caso de que la ruta más rápida y la más ecológica coincidan, es decir, sean la misma. También puede ocurrir que exista una única ruta o que existan sólo dos rutas diferentes para llegar al destino, en ese caso, una misma ruta aparecerá varias veces en la lista. Cuando el usuario seleccione una ruta, podrá ver las cantidades de gases nocivos emitidos para esa ruta, y desplegar una tabla con las indicaciones que debe tomar para llegar a su destino

Unbiased Rounding for HUB Floating-point Addition

Copyright (c) 2018 IEEE doi:10.1109/TC.2018.2807429Half-Unit-Biased (HUB) is an emerging format based on shifting the represented numbers by half Unit in the Last Place. This format simplifies two’s complement and roundto- nearest operations by preventing any carry propagation. This saves power consumption, time and area. Taking into account that the IEEE floating-point standard uses an unbiased rounding as the default mode, this feature is also desirable for HUB approaches. In this paper, we study the unbiased rounding for HUB floating-point addition in both as standalone operation and within FMA. We show two different alternatives to eliminate the bias when rounding the sum results, either partially or totally. We also present an error analysis and the implementation results of the proposed architectures to help the designers to decide what their best option are.TIN2013-42253-P, TIN2016-80920-R, JA2012P12-TIC-169

Fast HUB Floating-point Adder for FPGA

Several previous publications have shown the area and delay reduction when implementing real number computation using HUB formats for both floating-point and fixed-point. In this paper, we present a HUB floating-point adder for FPGA which greatly improves the speed of previous proposed HUB designs for these devices. Our architecture is based on the double path technique which reduces the execution time since each path works in parallel. We also deal with the implementation of unbiased rounding in the proposed adder. Experimental results are presented showing the goodness of the new HUB adder for FPGA.TIN2016- 80920-R, JA2012 P12-TIC-1692, JA2012 P12-TIC-147

A dynamical metric and its ground state from the breaking down of the topological invariance of the Euler characteristic

Quantum state wave functionals are constructed in exact form for the graviton-like field theory obtained by breaking down the topological symmetry of the string action related with the Euler characteristic of the world-surface; their continuous and discrete symmetries are discussed. The comparison with the so-called Chern-Simons state, which may be inappropriate as quantum state, allows us to conclude that the found wave functionals will give a plausible approximation to the ground state for the considered field theory

Protein conjugated with aldehydes derived from lipid peroxidation as an independent parameter of the carbonyl stress in the kidney damage

<p>Abstract</p> <p>Background</p> <p>One of the well-defined and characterized protein modifications usually produced by oxidation is carbonylation, an irreversible non-enzymatic modification of proteins. However, carbonyl groups can be introduced into proteins by non-oxidative mechanisms. Reactive carbonyl compounds have been observed to have increased in patients with renal failure. In the present work we have described a procedure designed as aldehyde capture to calculate the protein carbonyl stress derived solely from lipid peroxidation.</p> <p>Methods</p> <p>Acrolein-albumin adduct was prepared as standard at alkaline pH. Rat liver microsomal membranes and serum samples from patients with diabetic nephropathy were subjected to the aldehyde capture procedure and aldol-protein formation. Before alkalinization and incubation, samples were precipitated and redisolved in 6M guanidine. The absorbances of the samples were read with a spectrophotometer at 266 nm against a blank of guanidine.</p> <p>Results</p> <p>Evidence showed abundance of unsaturated aldehydes derived from lipid peroxidation in rat liver microsomal membranes and in the serum of diabetic patients with advanced chronic kidney disease. Carbonyl protein and aldol-proteins resulted higher in the diabetic nephropathy patients (p < 0.004 and p < 0.0001 respectively).</p> <p>Conclusion</p> <p>The aldehyde-protein adduct represents a non oxidative component of carbonyl stress, independent of the direct amino acid oxidation and could constitute a practical and novelty strategy to measure the carbonyl stress derived solely from lipid peroxidation and particularly in diabetic nephropathy patients. In addition, we are in a position to propose an alternative explanation of why alkalinization of urine attenuates rhabdomyolysis-induced renal dysfunction.</p

Analysis of galactic tides and stars on CDM microhalos

A special purpose N-body simulation has been built to understand the tidal heating of the smallest dark matter substructures (10^{-6}\msun and 0.01pc) from the grainy potential of the Milky Way due to individual stars in the disk and the bulge. To test the method we first run simulations of single encounters of microhalos with an isolated star, and compare with analytical predictions of the dark particle bound fraction as a function of impact parameter. We then follow the orbits of a set of microhalos in a realistic flattened Milky Way potential. We concentrate on (detectable) microhalos passing near the Sun with a range of pericenter and apocenter. Stellar perturbers near the orbital path of a microhalo would exert stochachstic impulses, which we apply in a Monte Carlo fashion according to the Besancon model for the distribution of stars of different masses and ages in our Galaxy. Also incorporated are the usual pericenter tidal heating and disk-shocking heating. We give a detailed diagnosis of typical microhalos and find microhalos with internal tangential anisotropy are slightly more robust than the ones with radial anisotropy. In addition, the dark particles generally go through of a random walk in velocity space and diffuse out of the microhalos. We show that the typical destruction time scales are strongly correlated with the stellar density averaged along a microhalo's orbit over the age of the stellar disk. We also present the morphology of a microhalo at several epochs which may hold the key to dark matter detections.Comment: 15 pages, 12 figure

Evolución de la contaminación del aire e impacto de los programas de control en tres megaciudades de América Latina

En este trabajo se discute la problemática de la contaminación del aire en tres megaciudades de América Latina (Ciudad de México, São Paulo y Santiago); en particular se revisan los programas de control de la contaminación atmosférica que han puesto en marcha los gobiernos de esas ciudades y la evolución de los niveles de contaminantes durante el periodo 1988-1995 en Santiago de Chile y São Paulo, y hasta 1997 en la Ciudad de México, con el objeto de evaluar el impacto de esos programas. En las tres megaciudades se observó un descenso en las concentraciones de PTS, PM10, SO2, NO2, CO y O3 durante el periodo mencionado, aunque la mayoría de los contaminantes siguen rebasando la norma de calidad del aire. Cabe destacar que el mayor impacto de los programas ha sido sobre los niveles de SO2. Se recomienda el desarrollo de políticas de transporte sostenible; en ese sentido, en la Conferencia Europea de Ministros del Transporte la Organización para la Cooperación y el Desarrollo Económico (OCDE) propuso distintas estrategias. Por otra parte, la participación ciudadana es importante al tomar decisiones relacionadas con las políticas de transport

Factorial Structure and Measurement Invariance of the Acceptance and Action Questionnaire-Stigma (AAQ-S) in Spain

The objective of the present study was to validate and adapt the Acceptance and Action Questionnaire-Stigma (AAQ-S) to the Spanish context. Method: The study included the participation of 1212 subjects, with an average age of 17.12 years old. Results: The confirmatory factorial analysis revealed a number of adequate fit indices for the new version of the scale χ2/df = 3.24; Comparative Fit Index = 0.96; Incremental Fit Index = 0.96; Root Mean Square Error of Approximation = 0.060; Standardized Root Mean Square Residual = 0.035, in which the factorial structures displayed gender invariance. The two factors comprise the scale both exhibited high internal consistency (+0.90) and temporal stability. Conclusion: The Spanish version of the AAQ-S proved to be a robust and adequate psychometric instrument. In this sense, future lines of research focused on determining the role of psychological flexibility in stigma and the processes of change at the base of interventions could benefit substantially from the use of AAQ-S

Regulando la coalianza en un juego motor de tríada

The ambivalence of the motor triad provides a social relationship which challenges the established games order. We start from the principle that the practice of the few existing triad motor games not always make the students experience the paradox from a decision-taking point of view. This is so because of the activity speed and the fact that players are aware of their co-alliance actions. The ‘allied ball’ game regulates this paradoxical situation and makes it clear for all players. In addition, it rebalances the antagonism with respect to solidarity, acting in favour of the latter. Communication in the proposed motor games is analyzed and a justification for the lack of focus on the problem of ambivalence is also given, together with solutions to that problem. The ‘allied ball’ game offers pedagogical advantages, such as helping to perceive in a clear way the paradoxical situation and the symbolic value of the ambivalence during its practice; from a curricular point of view, it shows a distinct contribution in comparison to other games and sports.La ambivalencia de la tríada motriz aporta un patrón de relación social que pone en entredicho el orden establecido en los juegos. Se parte del problema de que la práctica de los pocos juegos motores de tríada no siempre consigue en el alumnado vivenciar la paradoja desde el punto de vista decisional, debido a la rapidez de las acciones y a ser consciente el jugador de su acción de coalianza. El juego ‘pelota aliada’ regula la situación paradójica y la hace evidente para los jugadores; además, lo hace reequilibrando el antagonismo respecto a la solidaridad a favor de esta última. Se analiza la comunicación motriz del juego propuesto, y se justifica por qué hay una falta de enfoque respecto al problema de la ambivalencia, señalando soluciones. La aportación del juego ‘pelota aliada’ guarda ventajas pedagógicas, como ayudar a hacer consciente en la práctica la situación paradójica mediante la regla; desde el punto de vista curricular, muestra su aportación diferencial respecto a otros juegos y deportes