55 research outputs found
Test Case Generation for Object-Oriented Imperative Languages in CLP
Testing is a vital part of the software development process. Test Case
Generation (TCG) is the process of automatically generating a collection of
test cases which are applied to a system under test. White-box TCG is usually
performed by means of symbolic execution, i.e., instead of executing the
program on normal values (e.g., numbers), the program is executed on symbolic
values representing arbitrary values. When dealing with an object-oriented (OO)
imperative language, symbolic execution becomes challenging as, among other
things, it must be able to backtrack, complex heap-allocated data structures
should be created during the TCG process and features like inheritance, virtual
invocations and exceptions have to be taken into account. Due to its inherent
symbolic execution mechanism, we pursue in this paper that Constraint Logic
Programming (CLP) has a promising unexploited application field in TCG. We will
support our claim by developing a fully CLP-based framework to TCG of an OO
imperative language, and by assessing it on a corresponding implementation on a
set of challenging Java programs. A unique characteristic of our approach is
that it handles all language features using only CLP and without the need of
developing specific constraint operators (e.g., to model the heap)
Actor-based model checking for Software-Defined Networks
Software-Defined Networking (SDN) is a networking paradigm that has become
increasingly popular in the last decade. The unprecedented control over the
global behavior of the network it provides opens a range of new opportunities
for formal methods and much work has appeared in the last few years on
providing bridges between SDN and verification. This article advances this
research line and provides a link between SDN and traditional work on formal
methods for verification of concurrent and distributed software---actor-based
modelling. We show how SDN programs can be seamlessly modelled using
\emph{actors}, and thus existing advanced model checking techniques developed
for actors can be directly applied to verify a range of properties of SDN
networks, including consistency of flow tables, violation of safety policies,
and forwarding loops. Our model checker for SDN networks is available through
an online web interface, that also provides the SDN actor-models for a number
of well-known SDN benchmarks
Diseño de una metodología para la implantación de herramientas automáticas de corrección de estilo y buenas prácticas en asignaturas de programación
Depto. de Sistemas Informáticos y ComputaciónFac. de InformáticaFALSEsubmitte
Testing abstract behavioral specifications
We present a range of testing techniques for the Abstract Behavioral Specification (ABS) language and apply them to an industrial case study. ABS is a formal modeling language for highly variable, concurrent, component-based systems. The nature of these systems makes them susceptible to the introduction of subtle bugs that are hard to detect in the presence of steady adaptation. While static analysis techniques are available for an abstract language such as ABS, testing is still indispensable and complements analytic methods. We focus on fully automated testing techniques including blackbox and glassbox test generation as well as runtime assertion checking, which are shown to be effective in an industrial setting
Análisis de rendimiento de aplicaciones MPI en clusters de Raspberries Pi3
La asignatura Programación de Sistemas Distribuidos (PSD) dedica una parte del temario a las aplicaciones de alto rendimiento y, en particular, a las aplicaciones desarrolladas con MPI. En resumen, estas aplicaciones despliegan en las máquinas físicas del sistema distribuido una serie de procesos, los cuales deben explotar -de la forma más eficiente posible- los recursos compartidos del sistema para incrementar su rendimiento.
El objetivo principal de este proyecto consiste en analizar el rendimiento de clusters de bajo presupuesto, concretamente, de sistemas formados por placas Raspberry Pi3
Influenza-Like Illness Sentinel Surveillance in Peru
BACKGROUND: Acute respiratory illnesses and influenza-like illnesses (ILI) are a significant source of morbidity and mortality worldwide. Despite the public health importance, little is known about the etiology of these acute respiratory illnesses in many regions of South America. In 2006, the Peruvian Ministry of Health (MoH) and the US Naval Medical Research Center Detachment (NMRCD) initiated a collaboration to characterize the viral agents associated with ILI and to describe the clinical and epidemiological presentation of the affected population. METHODOLOGY/PRINCIPAL FINDINGS: Patients with ILI (fever > or =38 degrees C and cough or sore throat) were evaluated in clinics and hospitals in 13 Peruvian cities representative of the four main regions of the country. Nasal and oropharyngeal swabs, as well as epidemiological and demographic data, were collected from each patient. During the two years of this study (June 2006 through May 2008), a total of 6,835 patients, with a median age of 13 years, were recruited from 31 clinics and hospitals; 6,308 were enrolled by regular passive surveillance and 527 were enrolled as part of outbreak investigations. At least one respiratory virus was isolated from the specimens of 2,688 (42.6%) patients, with etiologies varying by age and geographical region. Overall the most common viral agents isolated were influenza A virus (25.1%), influenza B virus (9.7%), parainfluenza viruses 1, 2, and 3, (HPIV-1,-2,-3; 3.2%), herpes simplex virus (HSV; 2.6%), and adenoviruses (1.8%). Genetic analyses of influenza virus isolates demonstrated that three lineages of influenza A H1N1, one lineage of influenza A H3N2, and two lineages of influenza B were circulating in Peru during the course of this study. CONCLUSIONS: To our knowledge this is the most comprehensive study to date of the etiologic agents associated with ILI in Peru. These results demonstrate that a wide range of respiratory pathogens are circulating in Peru and this fact needs to be considered by clinicians when treating patients reporting with ILI. Furthermore, these data have implications for influenza vaccine design and implementation in South America
Adaptación y ejecución de aplicaciones MPI en entornos de simulación para analizar el rendimiento de arquitecturas distribuidas
Una parte fundamental de la asignatura PSD es el desarrollo de aplicaciones distribuidas. En concreto, la programación de aplicaciones paralelas utilizando MPI tiene un peso considerable, tanto en la parte práctica, como en la parte teórica de la asignatura. Las aplicaciones MPI desarrolladas en las prácticas de PSD pueden, normalmente, ejecutarse en un solo ordenador utilizando los distintos núcleos del procesador, lo cual se conoce como modo “stand-alone”.
El objetivo principal del proyecto consiste en mitigar los problemas existentes para ejecutar las aplicaciones MPI, requeridas en las prácticas de PSD, en entornos distribuidos reales. Para ello proponemos el uso del simulador SIMCAN, el cual ya ha sido adaptado en el pasado para su uso docente. Concretamente, se propone utilizar SIMCAN para reproducir las trazas de ejecución de aplicaciones MPI en diferentes arquitecturas distribuidas, de forma que se alivien, en la medida de lo posible, aquellos aspectos de interés que se tratan con dificultad en la ejecución “stand-alone”, en particular, la visualización del funcionamiento distribuido y su rendimiento. De esta forma, se utilizarán distintas arquitecturas distribuidas, modeladas con el simulador SIMCAN, para ejecutar las aplicaciones MPI estudiadas en la asignatura
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