Efficient Retrieval and Ranking of Undesired Package Cycles in Large Software Systems

International audienceMany design guidelines state that a software system architecture should avoid cycles between its packages. Yet such cycles appear again and again in many programs. We believe that the existing approaches for cycle detection are too coarse to assist developers to remove cycles from their programs. In this paper, we describe an efficient algorithm that performs a fine-grained analysis of cycles among application packages. In addition, we define multiple metrics to rank cycles by their level of undesirability, prioritizing cycles that are the more undesired by developers. We compare these multiple ranking metrics on four large and mature software systems in Java and Smalltalk

How to better estimate bunch number at vineyard level?

Despite the extensive use of sampling to estimate the average number of grape bunches per vine, there is no clearly established sampling protocol that can be used as a reference when performing these estimations. Each practitioner therefore has their own sampling protocol. This study characterised the effect of differences between sampling protocols in terms of estimation errors. The goal was to identify the most efficient practices that will improve the early estimation of an important yield component: average bunch number. First, the appropriateness of including non-productive vines (i.e., dead and missing vines) in the sampling protocol was tested; the objective was to determine whether it is relevant to estimate two yield components simultaneously. Second, sampling protocols with sampling sites of varying size were compared to determine how the spatial distribution of observations and potential spatial autocorrelation affect estimation error. Third, a new confidence interval for estimation error was determined to express expected error as a percentage. It aimed at designing a new tool for finding the best sample size in an operational context. Tests were performed on two vineyards in the South of France, in which the number of bunches per vine had been exhaustively determined on all the plants before flowering. The results show that the simultaneous estimation of number of bunches and proportion of dead and missing vines increased the estimation errors by a factor of 2. Despite the low spatial autocorrelation of bunch number, the results show that the observation must be spread across at least 2 or 3 sampling sites to reduce estimation errors. Finally, the confidence intervals expressed as a percentage were validated and used to define an adequate sample size based on a compromise between the expected precision and the variability observed in the first measurements

Aspects actuels des représentations de connaissances par objets et de la classification

napoli1997aNational audienceCet article présente certains thèmes de recherches étudiés par les membres du groupe "Objets et classification" du PRC-IA. Ces thèmes concernent essentiellement la théorie des systèmes de représentation de connaissances par objets (RCPO), la révision d'une base de connaissances dans les systèmes de RCPO, la classification de classes et d'instances, et la mise en oeuvre d'applications, illustrée ici par le système RESYN. Les travaux présentés montrent une certaine continuité avec les préoccupations des membres du groupe depuis qu'il existe. L'article se termine par la présentation d'éléments de définition d'un système de RCPO, et de perspectives de recherches découlant des thèmes explicités dans l'article

JFPC 2021: Actes des seizièmes Journées Francophones de Programmation par Contraintes

International audienceLes JFPC (Journées Francophones de Programmation par Contraintes) permettent chaque année de réunir la communauté francophone s'intéressant à la programmation par contraintes (CP). Cette conférence aborde de nombreux thèmes comme la résolution de problèmes de satisfaction de contraintes (CSP), d’optimisation sous contraintes (COP), de satisfiabilité d’une formule logique propositionnelle (SAT) ou de programmation logique avec contraintes (CLP). Les publications concernent les aspects théoriques et algorithmiques, les librairies et environnements de développement ainsi que les applications de la programmation par contraintes.L’édition 2021 qui devait avoir lieu à Nice s’est finalement déroulée en ligne à cause de la crise du Covid. Ces actes regroupent les 24 publications des JFPC 2021 qui sont également disponibles sur le site de la conférence (https://www.i3s.unice.fr/jfpc_2021/)

Eliminations des solutions symétriques pour l'isomorphisme de sous-graphe

International audienceLa programmation par contrainte fournit aujourd'hui des modèles efficaces pour résoudre les problèmes d'isomorphisme de sous-graphe. Beaucoup de problèmes réels nécessitent l'énumération de toutes les solutions qui ne sont pas équivalentes à une symétrie d'un des graphes traités. Dans cet article nous nous intéressons aux conditions sous lesquelles il est possible d’éliminer ces symétries en utilisant des contraintes lexicographiques. Dans le cas où le nombre de symétries devient trop important, nous proposons une méthode basée sur des contraintes ensemblistes

Union of All the Minimum Cycle Bases of a Graph

The perception of cyclic structures is a crucial step in the analysis of graphs. To describe the cycle vector space of a graph, a minimum cycle basis can be computed in polynomial time using an algorithm of [Horton, 1987]. But the set of cycles corresponding to a minimum basis is not always relevant for analyzing the cyclic structure of a graph. This restriction is due to the fact that a minimum cycle basis is generally not unique for a given graph. Therefore, the smallest canonical set of cycles which describes the cyclic structure of a graph is the union of all the minimum cycle bases . This set of cycles is called the set of relevant cycles and denoted by CR . A relevant cycle can also be defined as a cycle which is not the sum of shorter cycles. A polynomial algorithm is presented that computes a compact representation of the potentially exponential-sized set CR in O(m 3 ) (where denotes the cyclomatic number). This compact representation consists of a polynomial nu..

Castellu (Haute-Corse) - Un établissement rural de l'Antiquité tardive - Fouilles récentes (1981-1985)

Pergola Ph., Vismara Cinzia. Castellu (Haute-Corse) - Un établissement rural de l'Antiquité tardive - Fouilles récentes (1981-1985). In: Revue archéologique du Centre de la France, tome 29, fascicule 2, 1990. p. 208

Finding Maximum Common Connected Subgraphs Using Clique Detection or Constraint Satisfaction Algorithms

International audienceThis paper investigates the problem of Maximum Common Connected Subgraph (MCCS) which is not necessarily an induced subgraph. This problem has received little attention in the literature which is mainly devoted to the MCIS problem. Two reductions of the MCCS problem to a MCCIS problem are explored: a classic method based on linegraphs and an original approach using subdivision graphs. Then we propose a method to solve MCCS that searchs for a maximum clique in a compatibility graph. To compare with backtrack approach we explore the applicability of Constraint Satisfaction framework to the MCCS problem for both reductions

Castellu (Haute-Corse) - Un établissement rural de l'Antiquité tardive - Fouilles récentes (1981-1985)

Pergola Ph., Vismara Cinzia. Castellu (Haute-Corse) - Un établissement rural de l'Antiquité tardive - Fouilles récentes (1981-1985). In: Revue archéologique du Centre de la France, tome 29, fascicule 2, 1990. p. 208

La représentation de La fille Elisa à Milan et à Turin en décembre 1892

Messa Vismara Elena, Baron Philippe. La représentation de La fille Elisa à Milan et à Turin en décembre 1892. In: Cahiers Edmond et Jules de Goncourt n°5, 1997. pp. 154-166