6,141 research outputs found
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
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