1,720,993 research outputs found
Process Modelling for Requirements Capture
No full textAs software complexity increases, well defined managerial methods of organising software production become increasingly crucial to the success of software projects. As the investigation into the field of software process methodology continues, two approaches to process modelling have emerged as tools with which to model such processes. Graphical notations provide a clear, intuitive method of describing processes, whilst process modelling languages offer the ability to execute those processes. However, many existing process modelling languages are derived from programming languages, and, as such, inherit the low-level, syntactically complex attributes of these languages. The main goal of this thesis is to provide a process modelling language based on a well-known and practised graphical approach to modelling processes, the Role Activity Diagram (RAD). To ensure a high level of applicability, we emphasise the importance of ensuring that the language is readily accessible to those without a technical background. To this end, as well as being a linguistic approach with origins firmly in the process modelling field, models defined in this language are intended to exhibit a high level of abstraction and intuitiveness. This thesis proposes the Romula process modelling language as a complementary approach to Role Activity Diagrams, and describes a tool developed for animating processes modelled in this language. A discussion is presented which highlights the problems of animating Romula models derived from RADs which had to be overcome when developing Romula. Evaluation of the Romula language was achieved by validation and specification. For validation, the Romula approach was used to represent and execute two complex example process models. The first of these, named ProcMod, is a process model of a hypothetical software development process, itself validated by enacting it on a simple software development scenario. The second example process model is an implementation in Romula of a requirements-oriented process framework, presented as a method for representing the organisation of large software projects across multiple contributing entities. Examples of how this framework can be utilised are implemented in Romula. A method of translating Romula models into the formal specification notation CSP is also provided, demonstrated by example translations. This method enables Romula-derived CSP models to be checked for formal properties such as deadlock, livelock, and reachability, as well as providing a formal specification of the core semantics of the language
Inconsistency Tolerance across Enterprise Solutions
No full textAs every information system becomes connected to every other information system, they form the so-called "information utility". This is the domain in which contemporary distributed systems have to operate. New applications have to be evolved on this platform of existing systems that may hold inconsistent information. Consequently, solutions need to be able to work in a world of only partially correct information. In this paper, we discuss means whereby architects, designers and engineers may, in this context of information inconsistency, develop new business solutions and reason about their validity. In particular we describe the properties of inter-enterprise system architectures for applications working with partially replicated and partially consistent information. These must be able to operate under reversible assumptions. We have developed exemplary architectures that exhibit these properties, used them to investigate the concept of inconsistency-tolerant components and begun to devise methods of building inter-enterprise applications from such components. This approach, we conjecture, makes reasoning about the validity of proposed inter-enterprise scale solutions more straightforward and thus increases the speed with which such solutions can be deployed. We are evaluating these ideas now, by building, along with our industrial collaborators, realistic enterprise scale demonstrations of Finance and Defence
Utilising Located Functions to Model and Optimise Distributed Computations
No full textWith developments in Grid computing and Web based data storage the task of orchestrating computations is becoming ever more difficult. Identifying which of the available computation resources and datasets to use is not trivial: it requires reasoning about the problem itself and the cost of moving data to complete the computation efficiently. This paper presents a conceptual notation and performance model that enables e-researchers to reason about their computations and make choices about the best use of resources
M-grid: Using Ubiquitous Web Technologies to create a Computational Grid
No full textThere are many potential users and uses for grid computing. However, the concept of sharing computing resources excites security concerns and, whilst being powerful and flexible, at least for novices, existing systems are complex to install and use. Together these represent a significant barrier to potential users who are interested to see what grid computing can do. This paper describes m-grid, a system for building a computational grid which can accept tasks from any user with access to a web browser and distribute them to almost any machine with access to the internet and manages to do this without the installation of additional software or interfering with existing security arrangements
Towards Grid Interoperability
No full textThe Grid paradigm promises to provide global access to computing resources, data storage and experimental instruments. It also provides an elegant solution to many resource administration and provisioning problems while offering a platform for collaboration and resource sharing. Although substantial progress has been made towards these goals, nevertheless there is still a lot of work to be done until the Grid can deliver its promises. One of the central issues is the development of standards and Grid interoperability. Job execution is one of the key capabilities in all Grid environments. This is a well understood, mature area with standards and implementations. This paper describes some proof of concept experiments demonstrating the interoperability between various Grid environments
Imaging chromosome separation in mouse oocytes by responsive 3D confocal timelapse microscopy
No full textAccurate chromosome segregation is necessary so that genetic material is equally shared among daughter cells. However, maturing mammalian oocytes are particularly prone to chromosome segregation errors, making them a valuable tool for identifying the causes of mis-segregation. Factors such as aging, cohesion loss, DNA damage, and the roles of a plethora of kinetochore and cell cycle-related proteins are involved. To study chromosome segregation in oocytes in a live setting is an imaging challenge that requires advanced techniques. Here we describe a method for examining chromosomes in live oocytes in detail as they undergo maturation. Our method is based on tracking the "center of brightness" of fluorescently labeled chromosomes. Here we describe how to set up our software and run experiments on a Leica TCS SP8 confocal microscope, but the method would be transferable to other microscopes with computer-aided microscopy.</p
Effects of introducing survival behaviours into automated negotiators
No full textWith the rise of distributed e-commerce in recent years, demand for automated negotiation has increased. In turn, this has facilitated a demand for ever more complex algorithms to conduct these negotiations. As the complexity of these algorithms increases, our ability to reason about and predict their behaviour in an ever larger and more diverse negotiation environment decreases. In addition, with the proliferation of internet-based negotiation, any algorithm also has to contend with potential reliability issues in the underlying message-passing infrastructure. These factors can create problems for building these algorithms, which need to incorporate methods for survival as well as negotiation. This paper proposes a simple yet effective framework for integrating survivability into negotiators, so they are better able to withstand imperfections in their environment. Results of an experiment are provided which show how the stability of a negotiation community is affected by incorporating an example survival behaviour into negotiators operating in an environment developed to support this framework
PETRAS-IoT data management and sharing infrastructure: an evolution of IoT observatory (PEDASI)
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