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Du travail créatif à l'ensemble dissensuel : scènes de l'amatorat
No full textTalent, projects, vocation, inspiration... Since the 1990s, many organisations have cultivated leitmotifs inspired by the worlds of art and a romantic ideal associated with artists. This aestheticisation shows that, contrary to common belief, management is more concerned than ever with creativity at work. But beyond its appealing appearance, creative rhetoric deserves some nuance : the promise of fulfilment through creativity is not without interest for the hypermodern company. On the one hand, it invalidates any criticism of the alienating coldness of capitalism and justifies neoliberal ideology; on the other hand, this creativity often ultimately serves economic performance objectives. Moreover, forms of creativity that exist on the margins of organisations, such as amateur practices, seem to partially escape this instrumentalisation. This is why, as a counterpoint to management, this thesis proposes to understand amatorat as a form of work that suspends the ordinary rhythms of life and cannot be encapsulated by the utilitarian machine. And for good reason: amateurs do not work on their attachment to the things they love out of necessity, but out of desire. Drawing on the thinking of philosopher Jacques Rancière, I conducted an art-based investigation in small group music workshops at an association and a business school. Here, I present a few scenes from artistic performances to show how amateurs subvert the mechanisms of managerial assimilation and collectively form what I have called dissensual ensembles.Talent, projet, vocation, inspiration.. Depuis les années 1990, beaucoup d’organisations cultivent des leitmotivs inspirés des mondes de l’art et d’un idéal romantique associé aux artistes. Cette esthétisation montre que, contrairement à une idée reçue, le management se soucie plus que jamais de la créativité au travail. Mais au-delà de ses apparences séduisantes, la rhétorique créative mérite quelques réserves. En effet, la promesse d’épanouissement grâce à la créativité n’est pas dénuée d’intérêt pour l’entreprise hypermoderne. D’une part, elle rend caduque toute critique de la froideur aliénante du capitalisme et justifie l’idéologie néolibérale ; d’autre part, elle sert souvent in fine des objectifs de performance économique. Au demeurant, des formes de créativité subsistant en marge des organisations, à l’image des pratiques amateures, semblent partiellement échapper à cette instrumentalisation. Voilà pourquoi, en contrepoint du management, cette thèse propose de saisir l’amatorat comme une forme de travail qui suspend les rythmes ordinaires de la vie et ne saurait être encapsulée par la machine utilitariste. Et pour cause, l’amateur ne travaille pas par nécessité, mais bien par désir. En m’appropriant la pensée du philosophe Jacques Rancière, j’ai conduit une enquête basée sur l’art au sein d’ateliers musicaux en petits groupes dans une association et une école de commerce. Je présente ici quelques scènes de performances artistiques pour montrer comment les amateurs déjouent par subversion les mécanismes d’assimilation managériale, et forment collectivement ce que j’ai appelé des ensembles dissensuels
Opinion and report of the French Agency for Food, Environmental and Occupational Health and Safety (ANSES) relating to an analysis of the health risks associated with exposure to caterpillars with stinging hairs and the development of management recommendations
No full textXavier Bailly et Elsa Jourdain ne sont pas auteurs mais relecteurs du rapportInternational audienceSeveral species of Lepidoptera with caterpillars bearing urticating hairs are increasing their range in metropolitan France from year to year, such as the pine processionary (Thaumetopoea pityocampa Denis et Schiffermüller 1775) whose presence was historically limited to the south of France, and which is gradually being observed in the north and at higher altitudes. The procession period also seems to be appearing earlier. Climate change could have an impact on the range and phenology of this species, as well as other species of Lepidoptera with caterpillar bearing urticating hairs. Urticating caterpillars, which can trigger diffuse urticariform papules and allergic reactions for human people through contact with the skin, mucous membranes or inhalation, represent a health issue. These caterpillars also cause a health risk for animals and can have an impact on plants due to the resulting defoliation. This risk assessment therefore focused on the risk posed by these urticating caterpillars in areas where they have been established for a long time as well as in areas where they currently do not occur but could be colonized in the short or medium terms. One of the outputs of the evaluation consisted in identifying 55 different species of Lepidoptera with urticating caterpillars, for metropolitan France, but also for the overseas regions, based on the review by Kawamoto and Kumada (1984) and the GBIF database. In addition, detailed sheets for the well‐known species were drawn up, describing in particular their range, their phenology and the period when the urticating stages occur. A literature review as well as data from poison control centres and the analysis of the results of two surveys (of three associations of dermatologists/allergists and of occupational populations at risk) allowed to characterize the contexts of exposure and the human populations at risk. Concerning animal health, in addition to an epidemioclinical description based on the literature, data from veterinary poison control centres were analyzed in the specific case of dog exposure to the pine processionary between 1999 and 2021 in metropolitan french territory. Given the impact of these species of Lepidoptera on ecosystems, due to the defoliation they induce, this scientific opinion investigated the impact of these species on ecosystem services. The socio‐economic impacts of defoliations and risk management measures implemented in the event of an outbreak were studied based on a literature review and simulations for forest recreation. To represent risk for the whole metropolitan France territory, three risk maps of the human population exposure to the pine processionary, the oak processionary and the brown‐tail moth were designed at municipality level. A multi‐criteria analysis was undertaken to characterize danger (urticating caterpillars) and vulnerability of human populations. Then, the municipalities were ranked according to their level of danger and vulnerability. As a result, municipalities have been classified into 5 danger classes and 5 vulnerability classes. Based on a risk matrix with levels of hazard (abscissa axis) and levels of vulnerability (ordinate axis), 5 levels of risk were finally defined and the 34,816 municipalities of metropolitan France were classified according to their level of risk
Le contentieux des pactes d'associés
No full textThis thesis offers a renewed analysis of litigation arising from shareholders’ agreements by approaching it as a structural legal risk, and not as a mere factual contingency. The study first highlights the particular functionof such agreements, understood as instruments for covering the social uncertainty that runs through the company contract. The commitments they contain – mechanisms for the transfer of shares or stipulations requiring a certain behaviour – nevertheless reveal their own fragilities, likely to fuel disputes at the time of their implementation.The analysis then systematises the possible avenues for challenge and shows that litigation risk depends as much on the legal mechanisms involved as on the parties’ ability to activate or not activate such litigation.In response to this observation, the research develops a contractual model for the treatment of litigation risk,based on the autonomous notion of constraint, exercised either towards the parties or towards the judge.Through techniques such as waiver, interpretative prerogatives, and qualification or regime agreements, this model makes it possible to anticipate and frame potential disputes.Applied to the different types of commitments found in shareholders’ agreements, this model demonstrates its relevance while revealing the boundaries of contractualisation. It does not eliminate all possibilities of litigation, but enables one to grasp its logic and to propose a structured treatment from the very origin of the contract.Cette thèse propose une analyse renouvelée du contentieux des pactes d’associés en l’appréhendant comme un risque juridique structurel, et non comme une simple contingence factuelle. L’étude met d’abord en lumière la fonction particulière des pactes, entendus comme instruments de couverture de l’aléa social qui traversent le contrat de société. Les engagements qu’ils contiennent – mécanismes de transfert de droits sociaux ou stipulations permettant d’exiger un comportement – révèlent toutefois des fragilités propres, susceptibles de nourrir des contestations au moment de leur mise en œuvre. L’analyse systématise alors les voies de remise en cause possibles et montre que le risque contentieux dépend autant des mécanismes juridiques en cause que de la compétence des parties à activer ou non ce contentieux. Face à ce constat, la recherche élabore un modèle contractuel de traitement du risque contentieux, fondé sur la notion autonome de contrainte, exercée à destination des parties ou du juge. Par des techniques telles quel a renonciation, les prérogatives d’interprétation, les accords de qualification ou de régime, ce modèle permet d’anticiper et d’encadrer les contestations. Appliqué aux différents types d’engagements rencontrés dans les pactes d’associés, ce modèle démontre sa pertinence tout en révélant les frontières de la contractualisation. Il ne supprime pas toute possibilité de litige, mais permet d’en saisir la logique et d’en proposer un traitement structuré dès l’origine du contra
Existence of BV solutions for 2 × 2 hyperbolic balance laws for L ∞ initial data
No full textWe prove the existence of BV solutions for 2 × 2 system of hyperbolic balance laws in one space dimension with L ∞ initial data. The flux is assumed to have two genuinely nonlinear characteristic fields. We consider a general force which may possibly depend on time and space variables as well. To prove the existence, we assume the initial data to be small in L ∞ . Furthermore, we also study qualitative behaviour for entropy solutions to hyperbolic system of balance laws
Deep Learning for VWAP Execution in Crypto Markets: Beyond the Volume Curve
No full textInternational audienceVolume-Weighted Average Price (VWAP) is arguably the most prevalent benchmark for trade execution as it provides an unbiased standard for comparing performance across market participants. However, achieving VWAP is inherently challenging due to its dependence on two dynamic factors-volumes and prices. Traditional approaches typically focus on forecasting the market's volume curve, an assumption that may hold true under steady conditions but becomes suboptimal in more volatile environments or markets such as cryptocurrency where prediction error margins are higher. In this study, I propose a deep learning framework that directly optimizes the VWAP execution objective by bypassing the intermediate step of volume curve prediction. Leveraging automatic differentiation and custom loss functions, my method calibrates order allocation to minimize VWAP slippage, thereby fully addressing the complexities of the execution problem. My results demonstrate that this direct optimization approach consistently achieves lower VWAP slippage compared to conventional methods, even when utilizing a naive linear model presented in [9].They validate the observation that strategies optimized for VWAP performance tend to diverge from accurate volume curve predictions and thus underscore the advantage of directly modeling the execution objective. This research contributes a more efficient and robust framework for VWAP execution in volatile markets, illustrating the potential of deep learning in complex financial systems where direct objective optimization is crucial. Although my empirical analysis focuses on cryptocurrency markets, the underlying principles of the framework are readily applicable to other asset classes such as equities
Mandatory corporate sustainability due diligence and its limitations: the persistence of unequal exchange
No full textInternational audienceGlobal value chains are the main contemporary sites where workers’ exploitation and environmental degradation occur. In 2024, the EU approved the Corporate Sustainability Due Diligence Directive (CSDDD), which aims to make large companies perform due diligence in their value chains to prevent violations of human, environmental, and labour rights. Notably, this law does not apply only to EU companies but to all large transnational companies operating within the EU. In this chapter, we analyse the CSDDD from a world-system perspective, assessing whether it might address the unequal exchange between core and peripheral countries. As the CSDDD aims to enhance the respect of human rights, labour rights, and to fight climate change, it would jeopardize two of the pillars of unequal exchange, cheap labour, and cheap nature. However, we show that the law suffers from structural limitations, which will make it unlikely that this will happen. In turn, these limitations are linked to entrenched capital interests, which has limited the reach of regulation
Distribution de dividendes afférents à des parts sociales grevées d'usufruit : une solution déroutante
No full textInternational audienceDans ce commentaire d'un arrêt rendu par la troisième chambre civile de la Cour de cassation le 19 septembre 2024, je critique la solution retenue, selon laquelle l’usufruitier jouit d’un quasi-usufruit sur le dividende provenant de la distribution du produit de la vente de la totalité des actifs immobiliers d’une société civile immobilière. Non seulement le "produit de la vente" n'est pas un élément distribuable ; mais en outre, à mon avis, une distribution dont le montant n’excède pas celui des apports en numéraire et en nature constitue une distribution de dividendes revenant à l’usufruitier
A Competitive Posted-Price Mechanism for Online Budget-Feasible Auctions
No full textInternational audienceWe consider online procurement auctions, where the agents arrive sequentially, in random order, and have private costs for their services. The buyer aims to maximize a monotone submodular value function for the subset of agents whose services are procured, subject to a budget constraint on their payments. We consider a posted-price setting where upon each agent's arrival, the buyer decides on a payment offered to them. The agent accepts or rejects the offer, depending on whether the payment exceeds their cost, without revealing any other information about their private costs whatsoever. We present a randomized online posted-price mechanism with constant competitive ratio, thus resolving the main open question of (Badanidiyuru, Kleinberg and Singer, EC 2012). Posted-price mechanisms for online procurement typically operate by learning an estimation of the optimal value, denoted as OPT, and using it to determine the payments offered to the agents. The main challenge is to learn OPT within a constant factor from the agents' accept / reject responses to the payments offered. Our approach is based on an online test of whether our estimation is too low compared against OPT and a carefully designed adaptive search that gradually refines our estimation.</div
Approximating evidence via bounded harmonic means
No full textEfficient Bayesian model selection relies on the model evidence or marginal likelihood, whose computation often requires evaluating an intractable integral. The harmonic mean estimator (HME) has long been a standard method of approximating the evidence. While computationally simple, the version introduced by Newton and Raftery (1994) potentially suffers from infinite variance. To overcome this issue,Gelfand and Dey (1994) defined a standardized representation of the estimator based on an instrumental function and Robert and Wraith (2009) later proposed to use higher posterior density (HPD) indicators as instrumental functions. Following this approach, a practical method is proposed, based on an elliptical covering of the HPD region with non-overlapping ellipsoids. The resulting estimator, called the Elliptical Covering Marginal Likelihood Estimator (ECMLE), not only eliminates the infinite-variance issue of the original HME and allows exact volume computations, but is also able to be used in multimodal settings. Through several examples, we illustrate that ECMLE outperforms other recent methods such as THAMES and its improved version (Metodiev et al 2024, 2025). Moreover, ECMLE demonstrates lower variance, a key challenge that subsequent HME variants have sought to address, and provides more stable evidence approximations, even in challenging settings
On Maximum 2-Clubs
No full textInternational audienceWe consider the Maximum 2-Club problem where one is given as input an undirected graph G = (V,E) and seeks a subset of vertices S of maximum size such that any pair of vertices in S is connected by a path of length at most 2 in the graph induced by S. This problem is a natural relaxation of the famous Maximum Clique problem where any pair of vertices must be connected by an edge. Maximum 2-Club has been well-studied and is known to be NP-complete even on split graphs. It can be solved exactly in O^*(1.62ⁿ) time, where n denotes the number of vertices of the input graph, while being polynomial-time solvable on several graph classes. Parameterized algorithms for structural parameters have also been considered, leading in particular to an algorithm with a double-exponential dependence in the parameter treewidth. Such an algorithm is actually the best one known for the larger parameter vertex cover size up to a constant in the exponent. We provide new results in both directions. We first prove that the double-exponential dependence for parameter vertex cover size is unavoidable under the Exponential Time Hypothesis (ETH). This answers a question left open by Hartung, Komusiewicz, Nichterlein and Suchỳ [Hartung et al., 2015]. Our result also implies that the problem cannot be solved in time sub-exponential in n even for split graphs. We then provide an exact algorithm for the problem restricted to chordal graphs, running in O^*(1.1996ⁿ) time, by reducing Maximum 2-Club on this class to Maximum Independent Set on arbitrary graphs with the same number of vertices. The same reduction shows that we can enumerate all maximum (and inclusion-wise maximal) 2-clubs of a chordal graph in O^*(3^{n/3}) = O^*(1.4423ⁿ) time. We conclude by providing a construction of split graphs with Ω(3^{n/3}/poly(n)) maximum2-clubs, for some polynomial poly showing that the bound for enumeration is essentially tight