Towards a Unified Framework for Declarative Structured Communications

We present a unified framework for the declarative analysis of structured communications. By relying on a (timed) concurrent constraint programming language, we show that in addition to the usual operational techniques from process calculi, the analysis of structured communications can elegantly exploit logic-based reasoning techniques. We introduce a declarative interpretation of the language for structured communications proposed by Honda, Vasconcelos, and Kubo. Distinguishing features of our approach are: the possibility of including partial information (constraints) in the session model; the use of explicit time for reasoning about session duration and expiration; a tight correspondence with logic, which formally relates session execution and linear-time temporal logic formulas

Time Scales in Evolutionary Dynamics

Evolutionary game theory has traditionally assumed that all individuals in a population interact with each other between reproduction events. We show that eliminating this restriction by explicitly considering the time scales of interaction and selection leads to dramatic changes in the outcome of evolution. Examples include the selection of the inefficient strategy in the Harmony and Stag-Hunt games, and the disappearance of the coexistence state in the Snowdrift game. Our results hold for any population size and in the presence of a background of fitness.Comment: Final version with minor changes, accepted for publication in Physical Review Letter

Measuring Opencv.js performance with Wasm execution engine in desktop, embedded and mobile browsers

Current browsers have sophisticated execution environments for Javascript, and fast rendering engines. With the advent of HTML5, they accept digital cameras, and they can process, in real time, video streaming between browsers, allowing instant communications. In addition, the introduction of the low-level virtual machine (LLVM) allows image-processing libraries to be delivered, alongside web pages, as specialized scripts that execute in browser, with significant speed gains when compared to traditional Javascript engines. This make the browser a very suitable platform to deliver web applications with heavy image processing tasks, that execute at native speeds. However, measuring such performance in modern browsers is a demanding challenge. In this paper, a set of recommended practices to use and to benchmark Opencv.js are presented and obtained figures on several testbeds are discussed. Measurements involved a desktop PC, a selection of smartphones with mainstream processors, and a Raspberry Pi single-board computer, which resulted in several findings that confirm the maturity of mobile an embedded browser for image-processing with Javascript at client side, running at native speeds.Sociedad Argentina de Informática e Investigación Operativ

Measuring Opencv.js performance with Wasm execution engine in desktop, embedded and mobile browsers

Current browsers have sophisticated execution environments for Javascript, and fast rendering engines. With the advent of HTML5, they accept digital cameras, and they can process, in real time, video streaming between browsers, allowing instant communications. In addition, the introduction of the low-level virtual machine (LLVM) allows image-processing libraries to be delivered, alongside web pages, as specialized scripts that execute in browser, with significant speed gains when compared to traditional Javascript engines. This make the browser a very suitable platform to deliver web applications with heavy image processing tasks, that execute at native speeds. However, measuring such performance in modern browsers is a demanding challenge. In this paper, a set of recommended practices to use and to benchmark Opencv.js are presented and obtained figures on several testbeds are discussed. Measurements involved a desktop PC, a selection of smartphones with mainstream processors, and a Raspberry Pi single-board computer, which resulted in several findings that confirm the maturity of mobile an embedded browser for image-processing with Javascript at client side, running at native speeds.Sociedad Argentina de Informática e Investigación Operativ

Measuring Opencv.js performance with Wasm execution engine in desktop, embedded and mobile browsers

Current browsers have sophisticated execution environments for Javascript, and fast rendering engines. With the advent of HTML5, they accept digital cameras, and they can process, in real time, video streaming between browsers, allowing instant communications. In addition, the introduction of the low-level virtual machine (LLVM) allows image-processing libraries to be delivered, alongside web pages, as specialized scripts that execute in browser, with significant speed gains when compared to traditional Javascript engines. This make the browser a very suitable platform to deliver web applications with heavy image processing tasks, that execute at native speeds. However, measuring such performance in modern browsers is a demanding challenge. In this paper, a set of recommended practices to use and to benchmark Opencv.js are presented and obtained figures on several testbeds are discussed. Measurements involved a desktop PC, a selection of smartphones with mainstream processors, and a Raspberry Pi single-board computer, which resulted in several findings that confirm the maturity of mobile an embedded browser for image-processing with Javascript at client side, running at native speeds.Sociedad Argentina de Informática e Investigación Operativ

On the reduction of 4-oxo-4h-benzopyran-3-carbaldehydes : global and local electrophilicity patterns

The theoretical global and local electrophilicity patterns of substituted and chelated 4-oxo-4H-benzopyran-3-carbaldehydes (formylchromones) have been evaluated using the electrophilicity index proposed by Parr et al [J. Am. Chem. Soc. 1999, 121, 1922]. The complexation of formylchromones with aluminum predicts a strong electrophilic character of these compounds against nucleophiles. Local response at the active sites may also be assessed in terms of a global contribution described by the global electrophilicity, and a local contribution described by the variations in electrophilic Fukui function at those sites. The highest local electrophilicity is found at the formyl group of the chelated formylchromones, in spite of that, the highest positive charge is located on the pyrone carbonyl group. This result is consistent with the experimental observed reactivity displayed by 4-oxo-4H-benzopyran-3-carbaldehydes in the presence of 2-propanol and alumina

3D-Mesomechanical analysis of external sulfate attack in concrete

The present study focuses on degradation of concrete by external sulfate attack. The numerical model developed by the MECMAT/UPC group, incorporates coupled C-M analysis using a meso-mechanical approach with discrete cracking, using the MEF and zero thickness interface elements with a constitutive law based on nonlinear fracture mechanics concepts. Examples of application are run on 2D and 3D samples, with geometries and FE meshes generated with a code developed also in-house. The numerical analysis is carried out using two independent codes and a “staggered” procedure. The first code performs the mechanical analysis and the second the diffusive/reaction chemical problem. 2D uncoupled and coupled analysis are presented and discussed. Preliminary coupled 3D results are also presented and compared with equivalent 2D results, and the differences are detected and analyzed

GAMES: A new Scenario for Software and Knowledge Reuse

Games are a well-known test bed for testing search algorithms and learning methods, and many authors have presented numerous reasons for the research in this area. Nevertheless, they have not received the attention they deserve as software projects. In this paper, we analyze the applicability of software and knowledge reuse in the games domain. In spite of the need to find a good evaluation function, search algorithms and interface design can be said to be the primary concerns. In addition, we will discuss the current state of the main statistical learning methods and how they can be addressed from a software engineering point of view. So, this paper proposes a reliable environment and adequate tools, necessary in order to achieve high levels of reuse in the games domain

Towards Formal Interaction-Based Models of Grid Computing Infrastructures

Grid computing (GC) systems are large-scale virtual machines, built upon a massive pool of resources (processing time, storage, software) that often span multiple distributed domains. Concurrent users interact with the grid by adding new tasks; the grid is expected to assign resources to tasks in a fair, trustworthy way. These distinctive features of GC systems make their specification and verification a challenging issue. Although prior works have proposed formal approaches to the specification of GC systems, a precise account of the interaction model which underlies resource sharing has not been yet proposed. In this paper, we describe ongoing work aimed at filling in this gap. Our approach relies on (higher-order) process calculi: these core languages for concurrency offer a compositional framework in which GC systems can be precisely described and potentially reasoned about.Comment: In Proceedings DCM 2013, arXiv:1403.768