The 3DMA Middleware for Mobile Applications

Mobile devices have received much research interest in re- cent years. Mobility raises new issues such as more dynamic context, limited computing resources, and frequent disconnections. To handle these issues, we propose a middleware, called 3DMA, which introduces three requirements, 1) distribution, 2) decoupling and 3) decomposition. 3DMA uses a space based middleware approach combined with a set of workers which are able to act on the users behalf either to reduce load on the mobile device, or to support disconnected behavior. In order to demonstrate aspects of the middleware architecture we consider the development of a commonly used mobile application

Rapid Scaling Up of Insecticide-Treated Bed Net Coverage in Africa and Its Relationship with Development Assistance for Health: A Systematic Synthesis of Supply, Distribution, and Household Survey Data

Stephen Lim and colleagues use several sources of data to estimate the changes in distribution of insecticide-treated bed nets across Africa between 2000 and 2008, and to analyze the link between development assistance and net coverage

Event-Based Coordination of Process-Oriented Composite Applications

A process-oriented composite application aggregates functionality from a number of other applications and coordinates these applications according to a process model. Traditional approaches to develop process-oriented composite application rely on statically defined process models that are deployed into a process management engine. This approach has the advantage that application designers and users can comprehend the dependencies between the applications involved in the composition by referring to the process model. A major disadvantage however is that once deployed the behaviour of every execution of the composite application is expected to abide by its process model until this model is changed and re-deployed. This makes it difficult to enrich the application with even minor features, to plug-in new applications into the composition, or to hot-fix the composite application to meet special circumstances or demands (e.g. to personalise the application). This paper describes a technique for translating a process-oriented application into an event-based application which is more amenable to such runtime adaptation. The process-based and event-based views of the application can then co-exist and be synchronised offline if the changes become permanent and it is found desirable to reflect them in the process model

Experience Using a Coordination-Based Architecture for Adaptive Web Content Provision

There are many ways of achieving scalable dynamic web content. In previous work we have focused on dynamic content degradation using a standard architecture and a design-time 'Just In Case' methodology. In this paper, we address certain shortcomings witnessed in our previous work by using an alternate coordination-based architecture, which has interesting applicability to run-time web server adaptation. We first establish the viability of using this architecture for high-volume dynamic web content generation. In doing so, we establish its ability to maintain high throughput in overload conditions. We go on to show how we used the architecture to achieve a 'Just In Time' adaptation to achieve dynamic web content degradation in a running web application server

Linguistic Tool Based Information Elicitation in Large Heterogeneous Database Networks

. In this paper a logical model to facilitate pro-active elicitation of schema information from multiple heterogeneous information sources is presented. This is achieved through high-level descriptors -- constructed using the WordNet linguistic tool -- whose aim is to provide a consistent, logically organized view of information across multiple discrete heterogeneous sources. The model dynamically clusters databases into clumps located in a logical space, so that the elements within a cluster have a high degree of semantic correlation. Thus, interactions between remote database sites are focused, irrelevant information is filtered out and searches are accelerated. Keywords : Large Scale Heterogenious Database Network, Linguistic Tool, Relationship Discovery, Information Elicitation, Dynamic Database Clustering. 1 Introduction The multitude, diversity and complexity of on-line information sources makes discovery of appropriate information a significant obstacle to a large-scale distrib..

Middleware Support for Mobile Applications

Mobile devices have received much research interest in recent years. Mobility raises new issues such as more dynamic context, limited computing resources, and frequent disconnections. A middleware infrastructure for mobile computing must handle all these issues properly. In this project we propose a middleware, called 3DMA, to support mobile computing. We introduce three requirements, distribution, decoupling and decomposition as central issues for mobile middleware. 3DMA uses a space based middleware, which facilitates the implementation of decoupled behavior and support for disconnected operation and context awareness. This is done by defining a set of "workers" which are able to act on the users behalf either: to reduce load on the mobile device, and/or to support disconnected behavior. In order to demonstrate aspects of the middleware architecture we then consider the development of a commonly used mobile application

The estimation of invocation cost for composite services

When a new electronic service is composed from existing ones, the characteristics of the component services will naturally have a major influence on both the functional and the non-functional characteristics of the composite service. When more than one service satisfies the specified functional requirements of a given component for a composite service, these services can be differentiated on the basis of their non-functional properties. To ensure proper evaluation of various composition options, we propose to estimate the corresponding non-functional properties of a composite service during design time by taking into account the characteristics of the candidate services and the composition constructs used to integrate these services. In this paper, we describe the specification and estimation of the invocation cost based on different pricing models and the composition constructs possible in the workflow patterns for composite services.</p