11,148 research outputs found
Comprehensive Monitor-Oriented Compensation Programming
Compensation programming is typically used in the programming of web service
compositions whose correct implementation is crucial due to their handling of
security-critical activities such as financial transactions. While traditional
exception handling depends on the state of the system at the moment of failure,
compensation programming is significantly more challenging and dynamic because
it is dependent on the runtime execution flow - with the history of behaviour
of the system at the moment of failure affecting how to apply compensation. To
address this dynamic element, we propose the use of runtime monitors to
facilitate compensation programming, with monitors enabling the modeller to be
able to implicitly reason in terms of the runtime control flow, thus separating
the concerns of system building and compensation modelling. Our approach is
instantiated into an architecture and shown to be applicable to a case study.Comment: In Proceedings FESCA 2014, arXiv:1404.043
Environmental forensic evidence from perchlorate in dust fall
Summer in Malta is accompanied by fireworks as part of the numerous (about 85) religious festivals (festa) that occur throughout the period. We attempted to establish whether firework activity is truly following official trade statistics, which imply a decreasing trend, or otherwise. Firework manufacture critically depends on the availability of oxidising agents, two of which (KNO3, KClO3) being controlled by permits but not potassium perchlorate (KClO4) which is freely available. Recent changes in legislation have slightly decreased the quantity of KClO3 and increased that of KNO3 and according to official trade statistics, consumption of KClO4 has decreased from 17 t/a in 2010 to â 2.5 t/a during 2011--2014. However, from levels of perchlorate in dust fall and rate of total deposition we calculated the quantity of KClO4 used during 2012 and obtained â„ 90 t/a, 36 times the official figure. This situation is serious since the danger of accidental explosion during manufacture escalates as production intensifies. Also, contamination of the environment by firework-waste appears destined to remain high with possible consequent effects on human health.peer-reviewe
An Embedded Domain Specific Language to Model, Transform and Quality Assure Business Processes in Business-Driven Development
In Business-Driven Development (BDD), business process models are produced by business analysts. To ensure that the business requirements are satisfied, the IT solution is directly derived through a process of model refinement. If models do not contain all the required technical details or contain errors, the derived implementation would be incorrect and the BDD lifecycle would have to be repeated. In this project we present a functional domain specific language embedded in Haskell, with which: 1) models can rapidly be produced in a concise and abstract manner, 2) enables focus on the specifications rather than the implementation, 3) ensures that all the required details, to generate the executable code, are specified, 4) models can be transformed, analysed and interpreted in various ways, 5) quality assures models by carrying out three types of checks; by Haskell.s type checker, at construction-time and by functions that analyse the soundness of models, 6) enables users to define quality assured composite model transformations
Contracts for Interacting Two-Party Systems
This article deals with the interrelation of deontic operators in contracts
-- an aspect often neglected when considering only one of the involved parties.
On top of an automata-based semantics we formalise the onuses that obligations,
permissions and prohibitions on one party impose on the other. Such
formalisation allows for a clean notion of contract strictness and a derived
notion of contract conflict that is enriched with issues arising from party
interdependence.Comment: In Proceedings FLACOS 2012, arXiv:1209.169
Device-Centric Monitoring for Mobile Device Management
The ubiquity of computing devices has led to an increased need to ensure not
only that the applications deployed on them are correct with respect to their
specifications, but also that the devices are used in an appropriate manner,
especially in situations where the device is provided by a party other than the
actual user. Much work which has been done on runtime verification for mobile
devices and operating systems is mostly application-centric, resulting in
global, device-centric properties (e.g. the user may not send more than 100
messages per day across all applications) being difficult or impossible to
verify. In this paper we present a device-centric approach to runtime verify
the device behaviour against a device policy with the different applications
acting as independent components contributing to the overall behaviour of the
device. We also present an implementation for Android devices, and evaluate it
on a number of device-centric policies, reporting the empirical results
obtained.Comment: In Proceedings FESCA 2016, arXiv:1603.0837
Chloride binding to the anion transport binding sites of band 3. A 35Cl NMR study
Band 3 is an integral membrane protein that exchanges anions across the red cell membrane. Due to the abundance and the high turnover rate of the band 3 transport unit, the band 3 system is the most heavily used ion-transport system in a typical vertebrate organism. Here we show that 35Cl NMR enables direct and specific observation of substrate Cl- binding to band 3 transport sites, which are identified by a variety of criteria: (a) the sites are inhibited by 4,4'- dinitrostilbene -2,2'- disulfonate, which is known to inhibit competitively Cl- binding to band 3 transport sites; (b) the sites have affinities for 4,4'- dinitrostilbene -2,2'-disulfonate and Cl- that are quantitatively similar to the known affinities of band 3 transport sites for these anions; and (c) the sites have relative affinities for Cl-, HCO-3, F-, and I- that are quantitatively similar to the known relative affinities of band 3 transport sites for these anions. The 35Cl NMR assay also reveals a class of low affinity Cl- binding sites (KD much greater than 0.5 M) that are not affected by 4,4'- dinitrostilbene -2,2'- disulfonate. These low affinity sites may be responsible for the inhibition of band 3 catalyzed anion exchange that has been previously observed at high [Cl-]. In the following paper the 35Cl NMR assay is used to resolve the band 3 transport sites on opposite sides of the membrane, thereby enabling direct observation of the transmembrane recruitment of transport sites
Adult education in small states : the case of Malta
A small state faces several challenges with regard to adult continuing education and training. The paper discusses some of these challenges with specific reference to the Mediterranean small island state of Malta. It starts with a general discussion of some of the issues affecting adult education in a small state such as Malta that paves the way for the more focused analyses in the second and third sections. These sections focus on a selection of just two topics from among the many that affect adult education in Malta, namely those of adult education and work and adult education for sustainable development. These analyses are tackled from the perspective of the small state condition.peer-reviewe
Can Network Analysis Techniques help to Predict Design Dependencies? An Initial Study
The degree of dependencies among the modules of a software system is a key
attribute to characterize its design structure and its ability to evolve over
time. Several design problems are often correlated with undesired dependencies
among modules. Being able to anticipate those problems is important for
developers, so they can plan early for maintenance and refactoring efforts.
However, existing tools are limited to detecting undesired dependencies once
they appeared in the system. In this work, we investigate whether module
dependencies can be predicted (before they actually appear). Since the module
structure can be regarded as a network, i.e, a dependency graph, we leverage on
network features to analyze the dynamics of such a structure. In particular, we
apply link prediction techniques for this task. We conducted an evaluation on
two Java projects across several versions, using link prediction and machine
learning techniques, and assessed their performance for identifying new
dependencies from a project version to the next one. The results, although
preliminary, show that the link prediction approach is feasible for package
dependencies. Also, this work opens opportunities for further development of
software-specific strategies for dependency prediction.Comment: Accepted at ICSA 201
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