Analysis of Program Differences with Numerical Abstract Interpretation

International audienceWe present work in progress on the static analysis of software patches. Given two syntactically close versions of a program, our analysis can infer a semantic difference, and prove that both programs compute the same outputs when run on the same inputs. Our method is based on abstract interpretation, and parametric in the choice of an abstract domain. At the moment, we focus on numeric properties only, on a toy language. Our method is able to deal with infinite-state programs and unbounded executions, but it is limited to comparing terminating executions, ignoring non terminating ones.We first present a novel concrete collecting semantics, expressing the behaviors of both programs at the same time. We then show how to leverage classic numeric abstract domains, such as polyhedra or octagons, to build an effective static analysis. We also introduce a novel numeric domain to bound differences between the values of the variables in the two programs, which has linear cost, and the right amount of relationality to express useful properties of software patches. We implemented a prototype and experimented on a few small examples from the literature.In future work, we will consider extensions to non purely numeric programs, towards the analysis of realistic patches

Fan-C, a Frama-C plug-in for data flow verification

International audienceDO-178B compliant avionics development processes must both define the data and control flows of embedded software at design level, and verify flows are faithfully implemented in the source code. This verification is traditionally performed during dedicated code reviews, but such intellectual activities are costly and error-prone, especially for large and complex software. In this paper, we present the Fan-C plug-in, developed by Airbus on top of the abstract-interpretation-based value and dataflow analyses of the Frama-C platform, in order to automate this verification activity for C avionics software. We therefore describe the Airbus context, the Frama-C platform, its value analysis and related plug-ins, the Fan-C plug-in, and discuss analysis results and ongoing industrial deployment and qualification activities

Estudi ambiental de l'ús de la xarxa d'aigua potable a municipis petits i mitjans

Conèixer els patrons de consum d'aigua i electricitat de les xarxes d'abastament d'aigua potable és necessari per determinar quins factors influeixen en l'impacte ambiental i poder actuar per reduir aquest impacte. L'article presenta l'anàlisi estadística d'una mostra de 50 ciutats petites i mitjanes de l'estat espanyol, aportant dades generals així com definint models per a l'estimació de variables com el consum elèctric o la longitud de la xarxa en altres municipis.Conocer los patrones de consumo de agua y electricidad de las redes de abastecimiento de agua potable es necesario para determinar qué factores influyen en el impacto ambiental y poder actuar para reducir este impacto. El artículo presenta el análisis estadístico de una muestra de 50 ciudades pequeñas y medianas de España, aportando datos generales así como definiendo modelos para la estimación de variables como el consumo eléctrico o la longitud de la red en otros municipios.Understanding the patterns of consumption of water and electricity in water supply networks is needed to determine which factors influence the environmental impacts reduce its environmental burdens. The article presents a statistical analysis of a sample of 50 small and medium municipalities in Spain, including general information and defining models for estimating variables such as power consumption or the length of the network in other municipalities

Impacte ambiental de la construcció de la xarxa de subministrament d'aigua potable de Betanzos

La construcció de la xarxa necessària per al subministrament d'aigua potable per a la població genera impactes ambientals que han de ser avaluats per tal de reduir-los. L'article desenvolupa una metodologia que permet el càlcul dels impactes ambientals derivats de la construcció de la xarxa de subministrament d'aigua potable en ciutats. La metodologia ha estat aplicada a la xarxa d'abastament d'aigua potable del municipi de Betanzos (Galícia). Aquesta metodologia permetrà els dissenyadors i gestors de la xarxa incloure criteris ambientals en el (re)disseny de la xarxa.La construcción de la red necesaria para el suministro de agua potable para la población genera impactos ambientales que deben ser evaluados para reducirlos. El artículo desarrolla una metodología que permite el cálculo de los impactos ambientales derivados de la construcción de la red de abastecimiento de agua potable en ciudades. La metodología ha sido aplicada a la red de abastecimiento de agua potable del municipio de Betanzos (Galicia). Esta metodología permitirá a los diseñadores y gestores de la red incluir criterios ambientales en el (re)diseño de la red.The construction of networks required to supply drinking water to the population generates environmental impacts that must be assessed in order to be minimized. The article develops a methodology that allows calculation of the environmental impacts derived from the construction of drinking water supply networks in cities. The methodology has been applied to the drinking water supply network of the municipality of Betanzos (Galicia). This methodology will help the designers and managers of the network to include environmental criteria in the (re)design of the network

Optimització ambiental dels dipòsits municipals d'aigua potable

Unidad de excelencia María de Maeztu MdM-2015-0552Una recerca sobre els sistemes d'emmagatzematge d'aigua potable en 147 dipòsits municipals confirma que les característiques materials d'aquests són les principals contribuïdores al seu impacte ambiental, més que no pas el transport o el sistema d'instal·lació. Afecten especialment la capacitat d'emmagatzematge, la combinació de dimensions i la posició de la instal·lació. L'aplicació dels estàndards obtinguts a tres casos reals mostra una important disminució de les emissions de CO equivalent.Una recerca sobre els sistemes d'emmagatzematge d'aigua potable en 147 dipòsits municipals confirma que les característiques materials d'aquests són les principals contribuïdores al seu impacte ambiental, més que no pas el transport o el sistema d'instal·lació. Afecten especialment la capacitat d'emmagatzematge, la combinació de dimensions i la posició de la instal·lació. L'aplicació dels estàndards obtinguts a tres casos reals mostra una important disminució de les emissions de CO2 equivalent.A study onstorage systems of drinking water in 147 municipal deposits confirms that the material characteristics of these are the main contributors to their environmental impact, rather than transportation or the installation system. The storage capacity, dimensions combination and position of the installation are particularly affected. The application of the standards obtained to three case studies shows a significant reduction in CO2 equivalent emissions

An operational framework for sustainability assessment including local to global impacts : focus on waste management systems

Assessing the sustainability of waste management systems (WMSs) is key to reduce the impacts incurred by human activities. The article presents the development of an operational sustainability framework for the assessment of WMSs involving stakeholders and experts from different fields. The operational framework presented achieves comprehensiveness by including multidisciplinary impacts (environmental, social, and economic impacts), accounting for spatial differentiation regarding the occurrence and magnitude of the impacts (local to global) and complementing well-established methods in life cycle assessment (LCA) with local impact assessment methods. In this respect, the assessment of social local impacts (e.g., Odour, Landscape Disamenities), which has so far received little attention in the literature, has been included. The procedure for the definition of the operational framework is described in detail, including the selection of the impact categories and associated indicators. Finally, an aggregation method was defined considering the perception of stakeholders, allowing for aggregating the impact in five areas of protection (Prosperity, Human Well-Being, Human Health, Ecosystem Health and Natural Resources)

Spreading Static Analysis with Frama-C in Industrial Contexts

International audienceThis article deals with the usage of Frama-C to detect runtime-errors. As static analysis for runtime-error detection is not a novelty, we will present significant new usages in industrial contexts, which represent a change in the ways this kind of tool is employed. The main goal is to have a scalable methodology for using static analysis through the development process and by a development team. This goal is achieved by performing analysis on partial pieces of code, by using the ACSL language for interface definitions, by choosing a bottom-up strategy to process the code, and by enabling a well-balanced definition of actors and skills. The methodology, designed during the research project U3CAT, has been applied in industrial contexts with good results as for the quality of verifications and for the performance in the industrial process

Bisphosphonates alter trabecular bone collagen cross-linking and isomerization in beagle dog vertebra

Changes in organic matrix may contribute to the anti-fracture efficacy of anti-remodeling agents. Following one year of treatment in beagle dogs, bisphosphonates alter the organic matrix of vertebral trabecular bone, while raloxifene had no effect. These results show that pharmacological suppression of turnover alters the organic matrix component of bone. INTRODUCTION: The collagen matrix contributes significantly to a bone's fracture resistance yet the effects of anti-remodeling agents on collagen properties are unclear. The goal of this study was to assess changes in collagen cross-linking and isomerization following anti-remodeling treatment. METHODS: Skeletally mature female beagles were treated for one year with oral doses of vehicle (VEH), risedronate (RIS; 3 doses), alendronate (ALN; 3 doses), or raloxifene (RAL; 2 doses). The middle dose of RIS and ALN and the lower dose of RAL approximate doses used for treatment of post menopausal osteoporosis. Vertebral trabecular bone matrix was assessed for collagen isomerization (ratio of alpha/beta C-telopeptide [CTX]), enzymatic (pyridinoline [PYD] and deoxypyridinoline [DPD]), and non-enzymatic (pentosidine [PEN]) cross-links. RESULTS: All doses of both RIS and ALN increased PEN (+34-58%) and the ratio of PYD/DPD (+14-26%), and decreased the ratio of alpha/beta CTX (-29-56%) compared to VEH. RAL did not alter any collagen parameters. Bone turnover rate was significantly correlated to PEN (R = -0.664), alpha/beta CTX (R = 0.586), and PYD/DPD (R = -0.470). CONCLUSIONS: Bisphosphonate treatment significantly alters properties of bone collagen suggesting a contribution of the organic matrix to the anti-fracture efficacy of this drug class.The authors thank Dr. Keith Condon, Diana Jacob, Mary Hooser, and Lauren Waugh for histological preparation. This work was supported by NIH Grants AR047838 and AR007581 and research grants from The Alliance for Better Bone Health (Procter & Gamble Pharmaceuticals and sanofi-aventis), and Lilly Research Laboratories, as well as an unrestricted grant from Eli Lilly to INSERM. Merck and Co. kindly provided the alendronate. This investigation utilized an animal facility constructed with support from Research Facilities Improvement Program Grant Number C06 RR10601-01 from the National Center for Research Resources, National Institutes of Health

Geodesic Distance in Planar Graphs

We derive the exact generating function for planar maps (genus zero fatgraphs) with vertices of arbitrary even valence and with two marked points at a fixed geodesic distance. This is done in a purely combinatorial way based on a bijection with decorated trees, leading to a recursion relation on the geodesic distance. The latter is solved exactly in terms of discrete soliton-like expressions, suggesting an underlying integrable structure. We extract from this solution the fractal dimensions at the various (multi)-critical points, as well as the precise scaling forms of the continuum two-point functions and the probability distributions for the geodesic distance in (multi)-critical random surfaces. The two-point functions are shown to obey differential equations involving the residues of the KdV hierarchy.Comment: 38 pages, 8 figures, tex, harvmac, eps