Alire: a library repository manager for the open source Ada ecosystem

Open source movements are main players in today''s software landscape. Communities spring around programming languages, providing compilers, tooling and, chiefly, libraries built with these languages. Once a community reaches a certain critical mass, management of available libraries becomes a point of contention. Operating system providers and distributions often support but the most significant or mature libraries so, usually, language communities develop their own cross-platform software management tools. Examples abound with languages such as Python, OCaml, Rust, Haskell and others. The Ada community has been an exception to date, perhaps due to its smaller open source community. This work presents a working prototype tailored to the Ada compiler available to open source enthusiasts, GNAT. This tool is designedfrom two main principles: zero-cost infrastructure and a pure Ada work environment. Initially available for Linux-based systems, it relies on the semantic versioning paradigm for dependency resolution and uses Ada specification files to describe project releases and dependencies

The Meaning of the Cave. Virtuality as a finite domain of meaning

Esta comunicación gira en torno a lo virtual que vamos a caracterizar “como estar-fuera-de-ahí”; es decir, como si se tratase de una experiencia de la conciencia (y no de una estructura ontológica del mundo) que delimita un ámbito finito de sentido. Lo virtual quedaría definido como un lugar a donde se transita desde lo real-cotidiano. Se trata de un ámbito finito de sentido diferente al mundo de la vida cotidiana que es desde donde nos desplazamos a diferentes realidades. Transitar entre el ahí y fuera-de-ahí requiere un cambio de conciencia.This communication reflects upon virtuality, that we are going to characterize as “like being out there”; that is to say, as if it were an experience of the consciousness (and not an ontological structure of the world) that delimits a finite domain of meaning. Virtuality could be defined as a place to which one travels from what is real and daily. It is a finite domain of meaning which differs from the world of daily life, from where we move to different realities. To journey between there and outside there requires a change of consciousness

Reactive programming in Ada 2012 with RxAda

The ReactiveX API, also known as the Reactive Extensions in the. NET world, is a popular functional reactive programming framework for asynchronous, event-based, multithreaded programming. Although Ada built-in tasking reduces the dire needs for additional multithreading support of some other languages, the reactive approach has properties that are well-suited to the safety and maintainability culture predominant in the Ada world, such as complexity reduction, well-defined concurrency semantics, and enhanced legibility by means of concise and explicit information flows appealing to imperative reasoning. This work presents the design of a ReactiveX Ada implementation that aims to balance desirable library properties such as compile-time type-safety, amount of user-required generic instantiations, and a smooth learning curve for both library clients and maintainers. Concurrency design aspects of the library are detailed, showing how the Flat_Map and Thread abstractions have been implemented following Ada programming expectations, in particular with regard to task termination. In the intervening time from its first presentation, the library has gained implemented operators to the point of having all fundamental building blocks available. With RxAda, the Ada programmer can henceforth benefit from the abundant documentation existing for the language-agnostic ReactiveX approach without stepping out of the Ada tool chain

El sentido de la caverna : lo virtual como un ámbito finito de sentido

Esta comunicación gira en torno a lo virtual que vamos a caracterizar "como estar-fuera-de-ahí"; es decir, como si se tratase de una experiencia de la conciencia (y no de una estructura ontológica del mundo) que delimita un ámbito finito de sentido. Lo virtual quedaría definido como un lugar a donde se transita desde lo real-cotidiano. Se trata de un ámbito finito de sentido diferente al mundo de la vida cotidiana que es desde donde nos desplazamos a diferentes realidades. Transitar entre el ahí y fuera-de-ahí requiere un cambio de concienciaThis communication reflects upon virtuality, that we are going to characterize as "like being out there"; that is to say, as if it were an experience of the consciousness (and not an ontological structure of the world) that delimits a finite domain of meaning. Virtuality could be defined as a place to which one travels from what is real and daily. It is a finite domain of meaning which differs from the world of daily life, from where we move to different realities. To journey between there and outside there requires a change of consciousnes

Distributed Dynamic Sensor Assignment of Multiple Mobile Targets

Distributed scalable algorithms are sought in many multi-robot contexts. In this work we address the dynamic optimal linear assignment problem, exemplified as a target tracking mission in which mobile robots visually track mobile targets in a one-to-one capacity. We adapt our previous work on formation achievement by means of a distributed simplex variant, which results in a conceptually simple consensus solution, asynchronous in nature and requiring only local broadcast communications. This approach seamlessly tackles dynamic changes in both costs and network topology. Improvements designed to accelerate the global convergence in the face of dynamically evolving task rewards are described and evaluated with simulations that highlight the efficiency and scalability of the proposal. Experiments with a team of three Turtlebot robots are finally shown to validate the applicability of the algorithm

Género, Sexualidad y Posfeminismo en 50 Sombras de Grey

The Trilogy 50 Shades of Grey is a worldwide best-seller with more than 65 million copies sold in 2012. We base our analysis on E.L. James' trilogy together with the content analysis of the official online forums created by the Spanish publisher. The success of this trilogy is strongly related with the possibility to become a trending topic in these online forums. This circumstance invites to consider the forums as a very powerful information source for the analysis. E.L. James' books are a very well studied combination of conservatism, explicit sex, and transgressive sex ('porn chic', or 'porn for mums'). The attributed meanings to masculinity and femininity are linked to the most conservative meanings, showing stability and playing with elements of instability of the tradition, such as female empowerment and sexualisation, that characterize the postfeminism. The tension between postfeminism and tradition will be the basis of the analysis in this article, which pretends to be an incipient reflection about this editorial phenomenon.La publicación de la trilogía 50 Sombras de Grey ha sido un fenómeno editorial en todo el mundo, con más de 65 millones de copias vendidas en 2012. La base de este artículo es la trilogía escrita por E.L. James junto con los comentarios surgidos en torno a ella en los foros en Internet creados por la editorial española de su obra. Buena parte del éxito de la trilogía radica en su capacidad para convertirse en tema de conversación o trending-topic, lo que confirma los foros como una fuente relevante de información. Los libros de E.L. James presentan una estudiada combinación de conservadurismo y sexo explícito y supuestamente transgresor (porno-chic o porno para mamás). En ellos, los significados atribuidos a la masculinidad y a la feminidad entroncan con los significados más conservadores, mostrando su estabilidad, al tiempo que juegan con atributos desestabilizadores de esa tradición ¿como el empoderamiento y la sexualización de lo femenino, que son característicos del posfeminismo. Las tensiones entre posfeminismo y tradición serán los ejes de análisis de este artículo que se inscribe en una incipiente reflexión académica sobre este fenómeno editorial

Optimal role and position assignment in multi-robot freely reachable formations

Many multi-robot problems require the achievement of formations as part of the overall mission. This work considers a scenario in which unlabeled homogeneous robots must adopt a given formation pattern buildable anywhere in the environment. This involves finding the relative pose of the formation in regard to the initial robot positions, understood as a translation and a rotation; and the optimal assignment of the role of each robot within the formation. This paper provides an optimal solution for the combined parameters of translation, rotation and assignment that minimizes total displacement. To achieve this objective we first formally prove that the three decision variables are separable. Since computing the optimal assignment without accounting for the rotation is a computationally expensive problem, we propose an algorithm that efficiently computes the optimal roles together with the rotation. The algorithm is provably correct and finds the optimal solution in finite time. A distributed implementation is also discussed. Simulation results characterize the complexity of our solution and demonstrate its effectiveness

Navigating underground environments using simple topological representations

Underground environments are some of the most challenging for autonomous navigation. The long, featureless corridors, loose and slippery soils, bad illumination and unavailability of global localization make many traditional approaches struggle. In this work, a topological-based navigation system is presented that enables autonomous navigation of a ground robot in mine-like environments relying exclusively on a high-level topological representation of the tunnel network. The topological representation is used to generate high-level topological instructions used by the agent to navigate through corridors and intersections. A convolutional neural network (CNN) is used to detect all the galleries accessible to a robot from its current position. The use of a CNN proves to be a reliable approach to this problem, capable of detecting the galleries correctly in a wide variety of situations. The CNN is also able to detect galleries even in the presence of obstacles, which motivates the development of a reactive navigation system that can effectively exploit the predictions of the gallery detection