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    Flexible models for dynamic linking

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    AbstractDynamic linking supports flexible code deployment, allowing partially linked code to link further code on the fly, as needed. Thus, end-users enjoy the advantage of automatically receiving any updates, without any need for any explicit actions on their side, such as re-compilation, or re-linking. On the down side, two executions of a program may link in different versions of code, which in some cases causes subtle errors, and may mystify end-users.Dynamic linking in Java and C# are similar: the same linking phases are involved, soundness is based on similar ideas, and executions which do not throw linking errors give the same result. They are, however, not identical: the linking phases are combined differently, and take place in different order. Consequently, linking errors may be detected at different times by Java and C# runtime systems.We develop a non-deterministic model, which describes the behaviour of both Java and C# program executions. The non-determinism allows us to describe the design space, to distill the similarities between the two languages, and to use one proof of soundness for both. We also prove that all execution strategies are equivalent with respect to terminating executions that do not throw link errors: they give the same results

    Automatic Generation of Self-monitoring MASs from Multiparty Global Session Types in Jason

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    Global session types are behavioral types designed for specifying in a compact way multiparty interactions between distributed components, and verifying their correctness. We take advantage of the fact that global session types can be naturally represented as cyclic Prolog terms - which are directly supported by the Jason implementation of AgentSpeak - to allow simple automatic generation of self-monitoring MASs: given a global session type specifying an interaction protocol, and the implementation of a MAS where agents are expected to be compliant with it, we define a procedure for automatically deriving a self-monitoring MAS. Such a generated MAS ensures that agents conform to the protocol at run-time, by adding a monitor agent that checks that the ongoing conversation is correct w.r.t. the global session type. The feasibility of the approach has been experimented in Jason for a non-trivial example involving recursive global session types with alternative choice and fork type constructors. Although the main aim of this work is the development of a unit testing framework for MASs, the proposed approach can be also extended to implement a framework supporting self-recovering MASs

    Going Beyond Counting First Authors in Author Co-citation Analysis

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    The present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed

    Variations on the Author

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    “Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
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