On the duality between trees and disks

A combinatorial category Disks was introduced by Andr\'e Joyal to play a role in his definition of weak omega-category. He defined the category Theta to be dual to Disks. In the ensuing literature, a more concrete description of Theta was provided. In this paper we provide another proof of the dual equivalence and introduce various categories equivalent to Disk or Theta, each providing a helpful viewpoint. In this second version the paper's contents have been reorganized with the goal of a more readable presentation. We define augmented categories and their reduced counterparts (which lack a single trivial object of the augmented category). These augmented categories are more suitable for inductive arguments and their reduced counterparts are equivalent to Disk and Theta. The equivalence between Disk and Theta is demonstrated in Sections 4 and 6 using categories inductively defined (in Section 3) from intervals and ordinals. The last two sections take a more categorical perspective, constructing categories of so-called labeled trees and showing that they are equivalent to their inductively defined counterparts, and so to Disk and Theta. The distinction between augmented and reduced categories corrects an error in the first version where the terminal tree was included in the category Disk.Comment: 37 page

Hölder Continuous Implementation

Building upon the classical concept of Holder continuity and the notion of "continuous implementation"introduced in Oury and Tercieux (2009), we define Hölder continuous implementation. We show that, under a richness assumption on the payo proles (associated with outcomes), the following full characterization result holds for finite mechanisms: a social choice function is Hölder continuously implementable if and only if it is fully implementable in rationalizable messages.High order beliefs, Robust implementation

The Absolute Relativity Theory

This paper is a first presentation of a new approach of physics that we propose to refer as the Absolute Relativity Theory (ART) since it refutes the idea of a pre-existing space-time. It includes an algebraic definition of particles, interactions and Lagrangians. It proposed also a purely algebraic explanation of the passing of time phenomenon that leads to see usual Euler-Lagrange equations as the continuous version of the Knizhnik-Zamolodchikov monodromy. The identification of this monodromy with the local ones of the Lorentzian manifolds gives the Einstein equation algebraically explained in a quantized context. A fact that could lead to the unification of physics. By giving an algebraic classification of particles and interactions, the ART also proposes a new branch of physics, namely the Mass Quantification Theory, that provides a general method to calculate the characteristics of particles and interactions. Some examples are provided. The MQT also predicts the existence of as of today not yet observed particles that could be part of the dark matter. By giving a new interpretation of the weak interaction, it also suggests an interpretation of the so-called dark energy

Continuous Implementation

It is well-known that mechanism design literature makes many simplifying infor- mational assumptions in particular in terms of common knowledge of the environment among players. In this paper, we introduce a notion of continuous implementation and characterize when a social choice function is continuously implementable. More specif- ically, we say that a social choice function is continuously (partially) implementable if it is (partially) implementable for types in the model under study and it continues to be (partially) implementable for types "close" to this initial model. We ?rst show that if the model is of complete information a social choice function is continuously (partially) implementable only if it satis?es Maskin?s monotonicity. We then extend this result to general incomplete information settings and show that a social choice function is continuously (partially) implementable only if it is fully implementable in iterative dominance. For ?nite mechanisms, this condition is also su¢ cient. We also discuss implications of this characterization for the virtual implementation approach.High order beliefs, robust implementation

Revising the ISSN: Involving stakeholders to adapt a bibliographic standard to its ever-changing environment

International audienceThe International Standard Serial Number is one of the oldest identifiers in the bibliographic domain, and also one of the most widely used and known. It was first established as an ISO standard in 1975, as ISO 3297. Originally intended for printed serials, the ISSN standard has been able over time to evolve in order to meet the needs of its users. It has known four revisions since its first release, the latest being in 2007. ISSN are now applicable to serials and to other continuing resources, whether past, present or to be published or produced in the foreseeable future, whatever the medium of publication or production. Each ISO standard regularly undergoes systematic revisions. In April 2016, a vote on the opportunity of a systematic revision was issued by TC46/SC9 to all ISO member bodies. From April to September 2016, they will vote to support or not a complete review of the ISSN standard. Evolution of publishing models, forms and formats; emergence of new concepts and description standards in the library and publishing domains; apparition of new identifiers; and the development of linked data are the most important factors that justify why a revision of the ISSN standard should happen

ISSN: Transitioning to linked data

International audienceISSN numbers reliably identify all types of continuing resources worldwide: in 2007, the scope of the standard, originally limited to serials, was extended so as to also include ongoing integrating resources. Bibliographic records describing resources identified by an ISSN are produced by ISSN national centres – there are also in charge of their updates. ISSN records are regularly sent to the ISSN Register, a bibliographic database which currently contains more than 1.9 million records. The Register is maintained by the ISSN International Centre, which is also in charge of providing access to its bibliographic information through innovative tools and services. The ISSN International Centre sees linked data principles and tools as a prominent way to distribute information from its own Register; and more generally bibliographic information about continuing resources. It seeks also to harness the tremendous opportunities of re-using data from other organizations, belonging or not to the library world, in order to enhance its knowledge on its own data, and to propose better services. The ISSN International Centre has therefore launched several projects related to that domain. On one hand, it has participated to the development of PRESS OO , an extension of the FRBR OO ontology for continuing resources. On the other hand, it has launched ROAD, the Registry of Open Access Resources, which disseminates bibliographic information on open access publications in the web of data. These two experiments have helped the ISSN International Centre to start setting up its linked data policy – or policies: various data models will be designed to fit the needs of the different users; different services and tools will be provided to free users and to customers of the ISSN Portal

SHALL THE AMERICAN DREAM SUFFER DEATH?

SHALL THE AMERICAN DREAM SUFFER DEATH