Modelling and simulation framework for reactive transport of organic contaminants in bed-sediments using a pure java object - oriented paradigm

Numerical modelling and simulation of organic contaminant reactive transport in the environment is being increasingly relied upon for a wide range of tasks associated with risk-based decision-making, such as prediction of contaminant profiles, optimisation of remediation methods, and monitoring of changes resulting from an implemented remediation scheme. The lack of integration of multiple mechanistic models to a single modelling framework, however, has prevented the field of reactive transport modelling in bed-sediments from developing a cohesive understanding of contaminant fate and behaviour in the aquatic sediment environment. This paper will investigate the problems involved in the model integration process, discuss modelling and software development approaches, and present preliminary results from use of CORETRANS, a predictive modelling framework that simulates 1-dimensional organic contaminant reaction and transport in bed-sediments

Automated Workarounds from Java Program Specifications based on SAT Solving

The failures that bugs in software lead to can sometimes be bypassed by the so-called workarounds: when a (faulty) routine fails, alternative routines that the system offers can be used in place of the failing one, to circumvent the failure. Existing approaches to workaround-based system recovery consider workarounds that are produced from equivalent method sequences, automatically computed from user-provided abstract models, or directly produced from user-provided equivalent sequences of operations. In this paper, we present two techniques for computing workarounds from Java code equipped with formal specifications, that improve previous approaches in two respects. First, the particular state where the failure originated is actively involved in computing workarounds, thus leading to repairs that are more state specific. Second, our techniques automatically compute workarounds on concrete program state characterizations, avoiding abstract software models and user-provided equivalences. The first technique uses SAT solving to compute a sequence of methods that is equivalent to a failing method on a specific failing state, but which can also be generalized to schemas for workaround reuse. The second technique directly exploits SAT to circumvent a failing method, building a state that mimics the (correct) behaviour of a failing routine, from a specific program state too. We perform an experimental evaluation based on case studies involving implementations of collections and a library for date arithmetic, showing that the techniques can effectively compute workarounds from complex contracts in an important number of cases, in time that makes them feasible to be used for run-time repairs. Our results also show that our state-specific workarounds enable us to produce repairs in many cases where previous workaround-based approaches are inapplicable.Fil: Uva, Marcelo Ariel. Universidad Nacional de Río Cuarto; ArgentinaFil: Ponzio, Pablo Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; Argentina. Universidad Nacional de Río Cuarto; ArgentinaFil: Regis, Germán. Universidad Nacional de Río Cuarto; ArgentinaFil: Aguirre, Nazareno Matias. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; Argentina. Universidad Nacional de Río Cuarto; ArgentinaFil: Frias, Marcelo Fabian. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; Argentina. Instituto Tecnológico de Buenos Aires; Argentin

Preliminary specification and design documentation for software components to achieve catallaxy in computational systems

This Report is about the preliminary specifications and design documentation for software components to achieve Catallaxy in computational systems. -- Die Arbeit beschreibt die Spezifikation und das Design von Softwarekomponenten, um das Konzept der Katallaxie in Grid Systemen umzusetzen. Eine Einführung ordnet das Konzept der Katallaxie in bestehende Grid Taxonomien ein und stellt grundlegende Komponenten vor. Anschließend werden diese Komponenten auf ihre Anwendbarkeit in bestehenden Application Layer Netzwerken untersucht.Grid Computing