Schur Superpolynomials: Combinatorial Definition and Pieri Rule

Schur superpolynomials have been introduced recently as limiting cases of the Macdonald superpolynomials. It turns out that there are two natural super-extensions of the Schur polynomials: in the limit $q=t=0$ and $q=t\rightarrow\infty$, corresponding respectively to the Schur superpolynomials and their dual. However, a direct definition is missing. Here, we present a conjectural combinatorial definition for both of them, each being formulated in terms of a distinct extension of semi-standard tableaux. These two formulations are linked by another conjectural result, the Pieri rule for the Schur superpolynomials. Indeed, and this is an interesting novelty of the super case, the successive insertions of rows governed by this Pieri rule do not generate the tableaux underlying the Schur superpolynomials combinatorial construction, but rather those pertaining to their dual versions. As an aside, we present various extensions of the Schur bilinear identity

The supersymmetric Ruijsenaars-Schneider model

An integrable supersymmetric generalization of the trigonometric Ruijsenaars-Schneider model is presented whose symmetry algebra includes the super Poincar\'e algebra. Moreover, its Hamiltonian is showed to be diagonalized by the recently introduced Macdonald superpolynomials. Somewhat surprisingly, the consistency of the scalar product forces the discreteness of the Hilbert space.Comment: v1: 11 pages, 1 figure. v2: new format, 5 pages, short section added at the end of the article addressing the problem of consistency of the scalar product (e.g., positivity of the weight functions and the normalization of the ground state wave function). To appear in Physical Review Letter

CURIOUS: Intrinsically Motivated Modular Multi-Goal Reinforcement Learning

In open-ended environments, autonomous learning agents must set their own goals and build their own curriculum through an intrinsically motivated exploration. They may consider a large diversity of goals, aiming to discover what is controllable in their environments, and what is not. Because some goals might prove easy and some impossible, agents must actively select which goal to practice at any moment, to maximize their overall mastery on the set of learnable goals. This paper proposes CURIOUS, an algorithm that leverages 1) a modular Universal Value Function Approximator with hindsight learning to achieve a diversity of goals of different kinds within a unique policy and 2) an automated curriculum learning mechanism that biases the attention of the agent towards goals maximizing the absolute learning progress. Agents focus sequentially on goals of increasing complexity, and focus back on goals that are being forgotten. Experiments conducted in a new modular-goal robotic environment show the resulting developmental self-organization of a learning curriculum, and demonstrate properties of robustness to distracting goals, forgetting and changes in body properties.Comment: Accepted at ICML 201

A quartet of fermionic expressions for M(k,2k±1)M(k,2k\pm1) Virasoro characters via half-lattice paths

We derive new fermionic expressions for the characters of the Virasoro minimal models $M(k,2k\pm1)$ by analysing the recently introduced half-lattice paths. These fermionic expressions display a quasiparticle formulation characteristic of the $\phi_{2,1}$ and $\phi_{1,5}$ integrable perturbations. We find that they arise by imposing a simple restriction on the RSOS quasiparticle states of the unitary models $M(p,p+1)$. In fact, four fermionic expressions are obtained for each generating function of half-lattice paths of finite length $L$, and these lead to four distinct expressions for most characters $\chi^{k,2k\pm1}_{r,s}$. These are direct analogues of Melzer's expressions for $M(p,p+1)$, and their proof entails revisiting, reworking and refining a proof of Melzer's identities which used combinatorial transforms on lattice paths. We also derive a bosonic version of the generating functions of length $L$ half-lattice paths, this expression being notable in that it involves $q$-trinomial coefficients. Taking the $L\to\infty$ limit shows that the generating functions for infinite length half-lattice paths are indeed the Virasoro characters $\chi^{k,2k\pm1}_{r,s}$.Comment: 29 pages. v2: minor improvements, references adde

CLIC: Curriculum Learning and Imitation for object Control in non-rewarding environments

In this paper we study a new reinforcement learning setting where the environment is non-rewarding, contains several possibly related objects of various controllability, and where an apt agent Bob acts independently, with non-observable intentions. We argue that this setting defines a realistic scenario and we present a generic discrete-state discrete-action model of such environments. To learn in this environment, we propose an unsupervised reinforcement learning agent called CLIC for Curriculum Learning and Imitation for Control. CLIC learns to control individual objects in its environment, and imitates Bob's interactions with these objects. It selects objects to focus on when training and imitating by maximizing its learning progress. We show that CLIC is an effective baseline in our new setting. It can effectively observe Bob to gain control of objects faster, even if Bob is not explicitly teaching. It can also follow Bob when he acts as a mentor and provides ordered demonstrations. Finally, when Bob controls objects that the agent cannot, or in presence of a hierarchy between objects in the environment, we show that CLIC ignores non-reproducible and already mastered interactions with objects, resulting in a greater benefit from imitation

Soutenir le développement de compétences par la conception d’aides à l’apprentissage sur le cours de vie professionnelle

Cet article présente une réflexion entourant l’élaboration d’un modèle de conception de la formation visant une meilleure prise en compte de la réalité du camionneur. Derrière un problème de formation se cache un problème plus large de connaissances nécessaires pour affronter efficacement les situations de la vie et d’aide à l’apprentissage sur le cours de vie. Une telle aide nécessite préalablement de documenter la réalité du camionneur en termes d’activité de formation et d’activité de travail. Une observation participante d’une formation de camionneurs et une analyse de l’activité de travail ont été réalisées. Documenter ainsi la réalité du camionneur permet d’identifier des situations à transformer pour aider à l’efficacité et la sécurité des apprentis et des camionneurs. Cette réflexion a permis l’élaboration d’un modèle de conception proposant une double intervention : sur la formation et sur le travail comme moyen d’aider à l’apprentissage sur le cours de vie professionnelle.In the transformation context of work and of production methods, training plays a strategic role in the management of work efficiency and safety. However, training and human resource specialists run into a persistent gap between training and work reality, and this gap affects the successful application of training knowledge in the workplace itself. The exploration of new ways of bringing together training and the work environment in a balanced relationship is required. This article explores such tools through a reflection concerning the development of a planning model whose aim it is to enrich an initial training program for truck drivers by taking into account the reality of work itself.Three approaches that formulate the problem of training creation have been identified: one approach using human resource competencies, an approach with the transfer of training knowledge, and a third approach with the creation of action situations in the course of life. The study of these approaches makes it possible to define the nature and the means of intervention in training as linked to work reality. In the first approach, training is a tool that makes it possible to channel skills towards the company’s goals and strategies. This approach is based on the needs analysis of the organization as a prerequisite to determining desired behaviours in practice. The second approach asks about favourable conditions and of the means to ensure the application, in the work situation, of the knowledge learned. Finally, for the third approach, which is the one we favour, the problem of training and of practice is based on the problem of knowledge required to confront life situations. This approach sets out to facilitate learning in professional life course situations through the setting up of consistent sets of conditions conducive to learning. Training becomes one aid to learning among others. The course of life is defined as the ongoing process of constructing knowledge through action in life situations. The learning built up in this way makes up an individual’s knowledge base and is inseparable from his life experience. Any human action is a manifestation of prior life experience and also a transformation of this experience in the situation encountered.Using this approach makes it necessary, as a prerequisite, to document this life course reality from the perspective of human activity as a learning process. We have identified three trends: the situated learning approach, the praxeology trend, and the activity analysis approach. These share three beliefs on human activity: (1) knowledge is integrated into the action process, and is difficult to put into words; (2) to have access to practice content, it is necessary to have specific conditions which place the action process as the focus of the analysis; (3) the practice analysis requires that the actor be assisted in his reflection process by an outside person. In light of these approaches, we conducted a participative observation of the initial training of a truck driver as well as an analysis of the driver’s work activity.This qualitative approach enables us to have a very detailed comprehension of the activity of the learner undergoing training, and of the activity of the truck driver at work, in order to help him in his life course. Although our analysis identifies several aspects of the activity and of the underlying competencies, this reflection is limited here to the characteristics of the mechanical state management performed by the truck driver.The analysis of the learner’s training activity reveals learning oriented towards the integration of a standardized method to verify components covered by regulations. In this context, the learner’s focus is to follow as faithfully as possible the procedure learned, without forgetting the various steps. The analysis also reveals the more or less conscious use of knowledge as to the mechanical functioning of vehicles in the application of these verifications. From these characteristics of the training activity there emerge several difficulties on the level of the use of prior experiences in the carrying out of the training and in terms of the preparation for confronting the reality of work.The analysis of the truck driver’s activity when managing the mechanical state brings to light a reality very different from that learned in training. This management is characterized by three categories of action on the part of the truck driver: (1) characterize the various mechanical components and define the conditions of use as a function of the work to be done; (2) follow the dynamic process of the truck’s components and (3) act on the transformation process of the truck’s dynamic change. Thus, the work activity reveals the dynamic aspect of the mechanical state in the course of work, and brings out the importance of a continuous follow up of these transformations. From this point of view, the verification before departure is not a goal in itself but rather a characterization step of the truck within an ongoing process during work.From these results of the training activity analysis and of the work activity emerge several possible directions for recommendations on conditions for carrying out the training activity of learners, on training content, and on the conditions of carrying out the work of truck drivers. The content of these recommendations concerns training but also the setting up of technical tools and organizational adjustments which could be an aid to action and to learning in the truck driver’s professional life course.In light of these results, a model to plan training was set up. This model proposes to set up tools that can assist individuals to act and to learn in life situations. From this perspective, this model attempts to intervene both on the training level and also on the level of the work situation, seen as situations in the professional life course. The training situation intervention implies acting in two ways. First, it proposes actions upon the conditions of carrying out training. This requires the documentation of the training activity. Secondly, it proposes actions upon the training content as an aid to help the learner successfully deal with the reality of work. This second aspect also presupposes knowledge of the training activity but also of the truck driver’s work activity. Intervention in the work situation means helping the worker to act in a safe and efficient manner by means of his action situations. These interventions imply previous understanding of his work reality.Este artículo presenta una reflexión en torno a la elaboración de un modelo de concepción de la formación capaz de tomar en cuenta de mejor manera la realidad del camionero. Detrás de un problema de formación se esconde un problema más amplio de conocimientos necesarios para enfrentar las situaciones de vida y de ayuda al aprendizaje en el curso de la vida. Tal ayuda requiere previamente de documentar la realidad del camionero en términos de actividad de formación y de actividad de trabajo. Una observación participante de una actividad de formación de camioneros y un análisis de la actividad de trabajo fueron realizados. Documentar la realidad del camionero de esta manera permite identificar las situaciones a transformar para contribuir a la eficacia y la seguridad de los aprendices y de los camioneros. Esta reflexión ha permitido la elaboración de un modelo de concepción que propone una doble intervención: sobre la formación y sobre el trabajo como medio de ayudar al aprendizaje en el curso de la vida profesional

Quelle temporalité pour l'analyse d'une spéculation foncière ?: L'haussmannisation de la rue de la République à Marseille

International audienceAu moment de sa percée d'inspiration haussmannienne sous le Second Empire comme aujourd'hui, la rue Impériale devenue rue de la République est inscrite dans un projet d'aménagement de l'articulation entre ville et port à Marseille. L'actuel projet, baptisé « Euroméditerranée », s'étend sur 313 hectares de la gare Saint-Charles au fort Saint-Jean, et jusqu'à Arenc. Il s'agit de requalifier un grand secteur urbain, où vivent près de 30 000 habitants et travaillent plus de 20 000 personnes. Ce projet est une opération d'aménagement articulée au développement économique de nouvelles activités, avec la réalisation de 500 000 m2 de bureaux sur 15-20 ans, la création de 6 000 logements neufs et la réhabilitation de 7 000 logements, la création de commerces et d'équipements. L'objectif est l'implantation d'entreprises privées à vocation principalement tertiaire et internationale2. Il vient plus de cent ans après les opérations de construction menées dans le quartier de la Joliette, d'Arenc et du Lazaret par Paulin Talabot (docks) et par Jules Mirès puis Émile Pereire (immeubles résidentiels). Dans les deux cas, il s'agit d'orienter la ville vers les bassins portuaires de la Joliette, de « tirer » les beaux quartiers vers des espaces qui, en 1860, viennent d'être créés, gagnés sur la mer à l'occasion de la construction du port moderne, ou qui, aujourd'hui, viennent d'être libérés par la disparition de certaines activités en lien avec le port. L'essentiel du commerce maritime se fait désormais par Fos et les échanges de marchandises qui continuent de passer par Marseille peuvent être cantonnés dans les bassins du nord, laissant les bassins du sud au développement du trafic des voyageurs vers la Corse et vers le sud de la Méditerranée qui ne requiert pas tant d'infrastructures en arrière des quais. Dans les deux cas, il s'agit de construire un nouveau quartier résidentiel et économique en lien aussi avec la gare de chemin de fer, qui date de 1848 et dont le réaménagement est imposé pour accueillir le nouveau trafic dû à l'extension de la ligne TGV. Entre ces deux grandes intentions politiques de valorisation du site et quel que soit leur degré de réussite, la rue, sur plus d'un siècle, sert de résidence à des habitants qui y trouvent, selon leurs aspirations et selon les époques, une adresse plus ou moins recherchée

La percée originelle : entre aménagement urbain, transformation sociale et rentabilité financière

International audienceAu moment de sa percée sous Ie second Empire, la rue Imperiale est deja inscrite dans un projet d'aménagement de I'articulation entre ville et ports à Marseille, en lien avec les operations de construction menées dans les quartiers de la Joliette, d' Arenc et du Lazaret par P. Talabot (docks) et par J. Mires puis E. Pereire (immeubles residentiels). II s'agit d'orienter la ville vers les bassins portuaires de la Joliette, de « tirer » les beaux quartiers vers des espaces qui, en 1860, viennent d'être crées, gagnés sur la mer à I'occasion de la construction du port modeme. II s'agit de construire un nouveau quartier residentiel et economique, en lien aussi avec la gare de chemin de fer inaugurée en 1848. L'opération s'inscrit dans un grand mouvement national de transformations qu'on situe dans la continuite de 1a politique du prefet Haussmann a Paris. On y retrouve les memes acteurs collectifs que ceux dont Maurice Halbwachs a decrit les interactions pour Paris dans son ouvrage sur les expropriations [Halbwachs, 1909]. Dans cette veine, les travaux de Marcel Roncayolo sur les mecanismes de la planification urbaine et de la speculation [Roncayolo, 1996a] res tent d'actua-lire pour donner une intelligibilite aux transformations ii. grande echelle de Marseille et pour lire Ie jeu des uns et des autres comme un systeme d' acteurs qui fa~onnent les grands espaces

L 'haussmannisation de la rue de la République à Marseille: I'echec d'une spéculation foncière ?

International audienceAu moment de sa percee d'inspiration haussmannienne sous Ie Second Empire comme aujourd'hui, la rue Imperiale devenue rue de la Republique est in serite dans un projet d'amenagement de I'articulation entre ville et port a Marseille. L'actuel projet, baptise Euromediterranee, s'etend sur 313 ha de la gare Saint-Charles au fort Saint-Jean, et jusqu'a Arenc. II s'agit de requalifier un grand secteur urbain, ou vivent pres de 30 000 habitants et travaillent plus de 20 000 personnes. Ce projet est une operation d'amenagement articulee au developpement economique de nouvelles activites, avec la realisation de 500 000 m 2 de bureaux sur 15-20 ans, la creation de 6 000 logements neufs et rehabilitation de 7 000 logements, la creation de commerces et d'equipements. L'objectif est l'implantation d'entreprises privees a vocation principalement tertiaire et intemationale I. 11 vient plus de cent ans apres les operations de construction menees dans Ie quartier de la Joliette, d'Arenc et du Lazaret par P. Talabot (docks) et par J. Mires puis E. Pereire (immeubles residentiels). Dans les deux cas, il s'agit d'orienter la ville vers les bassins portuaires de la Joliette, de « tirer » les beaux quartiers vers des espaees qui, en 1860, viennent d'etre crees, gagnes sur la mer