L’appréciation des politiques de D.G.B. par les syndicats français

Cet article a pour objet d'explorer et de faire comprendre les divergences entre les divers systèmes de relations professionnelles en Europe de l'Ouest, principalement entre les systèmes français et allemand.This paper aims at exposing and clarifying the differences between various Systems of industrial relations in Western Europe, mainly between the French System and the German one.Many aspects of these two Systems are common, even though the experience is pursued throughout various means and methods: defence of workers, quest for control on management powers to decide, influence to be exterted on the legislative and economic regime.A closer approach is pursued between unions of France and Germany, and the latter is favoured by the actual economic crisis which bears on the economies and on the workers of both countries, and by the obligation of the unions to negotiate with multinational corporations. This effort is visible in France where the three main unions, CGT, CFDT and FO, in spite of certain differences between them, favour a trend towards widening European labour cooperation.This widening appears on two particular grounds: the appreciation of claim applications of both movements and the question of participation in management.On the first subject, it is obvious that the term "Collective bargaining" has a different meaning in France and in Germany.Even if the actual economic crisis draws together both movements, the intervention from the administration into the bargaining process and the ratification of agreement are turned down by the unions and the employers in Germany. Whereas, in France, for the last ten years, many general settlements regarding reduced workweek, social securities in any case of layoff, vocational training, levelling of fringe benefits between white-collars and workmen have been endorsed.Regarding wage-setting, things are different in both movements. Owing undoubtedly to the inter-union rivalry, french unions consider their System more beneficial than the German System, since their somewhat anarchical fight for wage increases enables them to consider at any time the workers' claims; whereas the German regime, more formal, implies a certain severity, some red-tape and an greater distance from a unions. In France, the plural unionism favours such procedure, but it does not mean that French unionsare not aware of that question of control of rank and file action, and there is no need for them to look after a more consistent union policy.Conflict of opinions of both regimes is reflected upon the problem of participation in management.The attitude of German unions towards co-determination raises at the same time interest and critic from French unionists. It is taken to task for not making enough room to unions, because participation in management is based upon direct votes from the staff rather than from rank and file. They also consider that this form of participation is naturally discouraging union members who wee a means for the employers to get the unions to accept responsibilities in spheres where decisions based on restrained deals slop out from them. It is said that where the union is weak, it is enough for the economic situation to become tight to see decisive influence pass out of their hands to the employers'.Moreover, it is clear that French unions with their acquired power do not reject a certain participation in decision making. For instance, in the nationalized firms, to oppose the State prerogatives, unions try to strenghten their role in them. CGT particularly does not give up searching in those fields to a form of representation in which it would succeed in reaching the majority with the help of consumers's representatives. CFDT is far more unwilling; it rather aims at decentralizing the use of control-power, in other words, self-management. FO, closer to the American concept of collective bargaining, give s preeminence to the latter and dismisses the participation in management to workers

Parameterized Matroid-Constrained Maximum Coverage

In this paper, we introduce the concept of Density-Balanced Subset in a matroid, in which independent sets can be sampled so as to guarantee that (i) each element has the same probability to be sampled, and (ii) those events are negatively correlated. These Density-Balanced Subsets are subsets in the ground set of a matroid in which the traditional notion of uniform random sampling can be extended. We then provide an application of this concept to the Matroid-Constrained Maximum Coverage problem. In this problem, given a matroid $\mathcal{M} = (V, \mathcal{I})$ of rank $k$ on a ground set $V$ and a coverage function $f$ on $V$, the goal is to find an independent set $S \in \mathcal{I}$ maximizing $f(S)$. This problem is an important special case of the much-studied submodular function maximization problem subject to a matroid constraint; this is also a generalization of the maximum $k$-cover problem in a graph. In this paper, assuming that the coverage function has a bounded frequency $\mu$ (i.e., any element of the underlying universe of the coverage function appears in at most $\mu$ sets), we design a procedure, parameterized by some integer $\rho$, to extract in polynomial time an approximate kernel of size $\rho \cdot k$ that is guaranteed to contain a $1 - (\mu - 1)/\rho$ approximation of the optimal solution. This procedure can then be used to get a Fixed-Parameter Tractable Approximation Scheme (FPT-AS) providing a $1 - \varepsilon$ approximation in time $(\mu/\varepsilon)^{O(k)} \cdot |V|^{O(1)}$. This generalizes and improves the results of [Manurangsi, 2019] and [Huang and Sellier, 2022], providing the first FPT-AS working on an arbitrary matroid. Moreover, because of its simplicity, the kernel construction can be performed in the streaming setting

Maximum Weight b-Matchings in Random-Order Streams

We consider the maximum weight $b$-matching problem in the random-order semi-streaming model. Assuming all weights are small integers drawn from $[1,W]$, we present a $2 - \frac{1}{2W} + \varepsilon$ approximation algorithm, using a memory of $O(\max(|M_G|, n) \cdot poly(\log(m),W,1/\varepsilon))$, where $|M_G|$ denotes the cardinality of the optimal matching. Our result generalizes that of Bernstein [Bernstein, 2015], which achieves a $3/2 + \varepsilon$ approximation for the maximum cardinality simple matching. When $W$ is small, our result also improves upon that of Gamlath et al. [Gamlath et al., 2019], which obtains a $2 - \delta$ approximation (for some small constant $\delta \sim 10^{-17}$) for the maximum weight simple matching. In particular, for the weighted $b$-matching problem, ours is the first result beating the approximation ratio of $2$. Our technique hinges on a generalized weighted version of edge-degree constrained subgraphs, originally developed by Bernstein and Stein [Bernstein and Stein, 2015]. Such a subgraph has bounded vertex degree (hence uses only a small number of edges), and can be easily computed. The fact that it contains a $2 - \frac{1}{2W} + \varepsilon$ approximation of the maximum weight matching is proved using the classical K\H{o}nig-Egerv\'ary's duality theorem

Robust Sparsification for Matroid Intersection with Applications

Matroid intersection is a classical optimization problem where, given two matroids over the same ground set, the goal is to find the largest common independent set. In this paper, we show that there exists a certain "sparsifer": a subset of elements, of size $O(|S^{opt}| \cdot 1/\varepsilon)$, where $S^{opt}$ denotes the optimal solution, that is guaranteed to contain a $3/2 + \varepsilon$ approximation, while guaranteeing certain robustness properties. We call such a small subset a Density Constrained Subset (DCS), which is inspired by the Edge-Degree Constrained Subgraph (EDCS) [Bernstein and Stein, 2015], originally designed for the maximum cardinality matching problem in a graph. Our proof is constructive and hinges on a greedy decomposition of matroids, which we call the density-based decomposition. We show that this sparsifier has certain robustness properties that can be used in one-way communication and random-order streaming models

L'analyse sociétale revisitée

(Document Séminaire; 98-8). 136 p.Revisiter l'analyse sociétale, vingt ans après, permet d'ouvrir une discussion critique à propos des fondements théoriques et méthodologiques de cette approche qui pour beaucoup est identifiée à "la recherche France/Allemagne du LEST" de la fin des années 70 (ce qui n'invalide pas pour autant ses capacités analytiques et de compréhension des phénomènes socio-économiques). Les textes de base de ce document ont été conçus pour une publication en anglais (1999). La présentation qu'en ont faite leurs auteurs, en primeur au LEST, a permis d'ouvrir une large discussion dont on trouvera aussi l'essentiel des arguments. Il est vrai que beaucoup de questions se posent encore aujourd'hui à la fois sur le statut "théorique" de l'analyse sociétale et sur la pertinence de ses concepts, ainsi que sur la validité de la notion même de "sociétal" fondée, à l'origine, sur une comparaison d'Etats-nations alors que les sciences sociales sont sensibles aujourd'hui aussi bien au "local" ou "régional" qu'au "supra-national" voir même à la "globalisation". Les différents auteurs montrent cependant que l'analyse sociétale s'ouvre à ces nouvelles dimensions, en s'inspirant parfois d'approches voisines, même si la manière de les traiter offre encore matière à discussion

L'analyse sociétale revisitée

(Document Séminaire; 98-8). 136 p.Revisiter l'analyse sociétale, vingt ans après, permet d'ouvrir une discussion critique à propos des fondements théoriques et méthodologiques de cette approche qui pour beaucoup est identifiée à "la recherche France/Allemagne du LEST" de la fin des années 70 (ce qui n'invalide pas pour autant ses capacités analytiques et de compréhension des phénomènes socio-économiques). Les textes de base de ce document ont été conçus pour une publication en anglais (1999). La présentation qu'en ont faite leurs auteurs, en primeur au LEST, a permis d'ouvrir une large discussion dont on trouvera aussi l'essentiel des arguments. Il est vrai que beaucoup de questions se posent encore aujourd'hui à la fois sur le statut "théorique" de l'analyse sociétale et sur la pertinence de ses concepts, ainsi que sur la validité de la notion même de "sociétal" fondée, à l'origine, sur une comparaison d'Etats-nations alors que les sciences sociales sont sensibles aujourd'hui aussi bien au "local" ou "régional" qu'au "supra-national" voir même à la "globalisation". Les différents auteurs montrent cependant que l'analyse sociétale s'ouvre à ces nouvelles dimensions, en s'inspirant parfois d'approches voisines, même si la manière de les traiter offre encore matière à discussion

The Sparse Cardinal Sine Decomposition applied to Stokes integral equations

International audienceNumerical simulations of two-phase flows driven by viscosity (e.g. for bubble motions in glass melting process) rely on the ability to efficiently compute the solutions to discretized Stokes equations. When using boundary element methods to track fluid interfaces, one usually faces the problem of solving linear systems with a dense matrix with a size proportional to the system number of degrees of freedom. Acceleration techniques, based on the compression of the underlying matrix and efficient matrix vector products are known (Fast Multipole Method, H-matrices, etc.) but are usually rather cumbersome to develop. More recently, a new method was proposed, called the " Sparse Cardinal Sine Decomposition " , in the context of acoustic problems to tackle this kind of problem in some generality (in particular with respect to the Green kernel of the problem). The proposed contribution aims at showing the potential applicability of the method in the context of viscous flows governed by Stokes equations

Half-integer Shapiro steps at the 0-pi crossover of a ferromagnetic Josephson junction

We investigate the current-phase relation of S/F/S junctions near the crossover between the 0 and the pi ground states. We use Nb/CuNi/Nb junctions where this crossover is driven both by thickness and temperature. For a certain thickness a non-zero minimum of critical current is observed at the crossover temperature. We analyze this residual supercurrent by applying a high frequency excitation and observe the formation of half-integer Shapiro steps. We attribute these fractional steps to a doubling of the Josephson frequency due to a sin(2*phi) current-phase relation. This phase dependence is explained by the splitting of the energy levels in the ferromagnetic exchange field.Comment: 4 pages, 5 figures, accepted for publication in Phys. Rev. Let

Hepatitis E Virus infection in HIV-infected patients with elevated serum transaminases levels

Increases in aminotransferases levels are frequently encountered in HIV-positive patients and often remain unexplained. The role in this setting and natural history of hepatitis E in HIV-infected patients are unknown. The aim of the study was to assess HEV infection in HIV-infected patients attending a Parisian hospital, with a current or previous cryptogenic hepatitis.191 plasma samples collected from 108 HIV-infected patients with elevated aminotransferases levels were retrospectively tested for the presence of hepatitis E virus (HEV) infection markers: anti-HEV IgM antibodies, anti-HEV IgG antibodies, anti-HEV IgG avidity index and plasma HEV RNA.One acute infection, documented by positive tests for anti-HEV IgM antibody, low anti-HEV IgG avidity index and plasma HEV RNA (genotype 3e), and three past infections were diagnosed, without any observed case of persistent infection. The acute hepatitis was benign and resolved spontaneously within two weeks. This infection was probably contracted locally. Acute HEV hepatitis can occur in HIV-infected patients but rarely explains cryptogenic hepatitis, at least in an urban HIV population, regardless geographic origin and CD4 counts