Summary In recent years, fog computing has emerged as a new distributed system model for a large class of applications that are data‐intensive or delay‐sensitive. By exploiting widely distributed computing infrastructure that is located closer to the network edge, communication cost and service response time can be significantly reduced. However, developing this class of applications is not straightforward and requires addressing three key challenges, ie, supporting the dynamic nature of the edge network, managing the context‐dependent characteristics of application logic, and dealing with the large scale of the system. In this paper, we present a case study in building fog computing applications using our open source platform Distributed Node‐RED (DNR). In particular, we show how applications can be decomposed and deployed to a geographically distributed infrastructure using DNR, and how existing software components can be adapted and reused to participate in fog applications. We present a lab‐based implementation of a fog application built using DNR that addresses the first two of the issues highlighted earlier. To validate that our approach also deals with large scale, we augment our live trial with a large scale simulation of the application model, conducted in Omnet++, which shows the scalability of the model and how it supports the dynamic nature of fog applications.

Cloud based Smart City hubs are an attractive approach to addressing some of the complex issues faced when deploying PaaS infrastructure for Smart Cities. In this paper we introduce the general notion of IoT hubs and then discuss our work to generalize our IoT hub as a Smart City PaaS. We briefly describe our approach and discuss our experiences deploying two cloud-based Smart City hubs, one in the UK and the other in Canada.

Hybrid cloud deployment can be an attractive option for companies wanting to deploy software services on scalable public clouds, while still assuming local control over sensitive data resources. A hybrid deployment, despite providing better control, is difficult to design since code must be partitioned and distributed efficiently between public and private premises. This paper describes our research into automated partitioning of software services for hybrid clouds. We have identified two specific shortfalls of existing partitioning research which are important to a hybrid cloud setting: (i) inflexibility in placement of software function execution between public/private hosts and (ii) no support for making explicit tradeoffs between monetary cost and performance. We propose a new software profiling and partitioning framework (called MANTICORE) which addresses these problems. Experiments on an open-source Web application show that the new approach ensures better performance without increasing costs.

There has been significant research interest over recent years in the use of public digital displays and in particular their capability to offer both interactivity and personalized content. Although a number of interaction technologies have been investigated, a promising approach has been the use of the ubiquitous cell phone, which not only offers a means to interact with displays but increasingly offers a small but high-quality screen to complement the larger public display. However, to date there has been little investigation into the impact on users when interfaces are distributed across this type of dual screen setup. This article reports on a series of experiments carried out to determine if there is a significant quantitative or qualitative effect on user performance when interaction is split across large public and smaller private screens.

The use of a dual mobile and large screen approach offers a number of intriguing possibilities including a potential solution to the problem of managing conflicts that arise when a large screen is shared in a public setting. Here, we report on a series of experiments carried out to determine quantitative or qualitative effects of user performance when interaction is split across large public and smaller private screens. Our position is that using mobile devices as an auxiliary device for interaction can boost user experience when interacting with large displays.

Having the notion of services brought into the domain of component based software design has enriched the domain of modular self-contained components with support for loose coupling, dynamic runtime discovery, and late binding. However, loose coupling, runtime discovery, and composition for a service-oriented component model in its current scale mostly applies to homogeneous services that admit to the specifications of the original service component model. This design is in conflict with the initial outlook of SOA in which reusability of existing services is considered a primary goal. In this paper, we discuss ReCoIn, a remote service composition and integration framework, which aims to bring functionalities of traditional Web services into the local repository of a service oriented component model. We discuss how ReCoIn enables remote Web services to be properly discovered, encapsulated, and used in a service oriented component model framework, offering better service reuse and fault tolerance. In this paper, we layout the overall architectural design for ReCoIn and present its initial prototype.

In this paper, we reflect on the design and deployment process of MAGICBoard, a public display deployed in a university setting that solicits the electronic votes and opinions of bystanders on trivial but amusing topics. We focus on the consequences of our design choices with respect to encouraging bystanders to interact with the public display. Bystanders are individuals around the large display who may never fully engage with the application itself, but are potential contributors to the system. Drawing on our recent experiences with MAGICBoard, we present a classification of bystanders, and then discuss three design themes relevant to the design of systems for bystander use: graduated proximal engagement, lowering barriers for interaction and supporting covert engagement.

Large screen displays are being increasingly deployed in public areas for advertising, entertainment, and information display. Recently we have witnessed increasing interest in supporting interaction with such displays using personal mobile devices. To enable the rapid development of public large screen interactive applications, we have designed and developed the MAGIC Broker. The MAGIC Broker provides a set of common abstractions and a RESTful Web services protocol to easily program interactive public large screen display applications with a focus on mobile device interactions. We have carried out a preliminary evaluation of the MAGIC Broker via the development of a number of prototypes and believe our toolkit is a valid first step in developing a generic support infrastructure to empower developers of interactive large screen display applications.

The DART (Distributed Adaptive Run-Time) project is developing an adaptive software environment for general-purpose distributed applications. The goal of the project is to provide a software run-time system that allows application authors to quickly develop distributed software, such as network or World Wide Web software, without having to deal with the details of the distribution technology. DART compile-time and run-time components configure the application execution environments depending on hints provided with the application. An essential feature of the run-time component is its ability to reconfigure, or adapt itself, both to the application requirements and to the system and networking environment. To achieve both distribution and adaptation, we use meta-level object programming techniques and run-time monitoring.

Flexibility to adapt to different applications is a key requirement of modern operating systems. We have explored the use of meta-objects and reflection as a means to write adaptable system software. The paper discusses the Apertos operating system, that uses these techniques. It outlines how meta-objects help to support flexibility and how we have implemented the concepts, and gives some performance figures.