Intelligent and pervasive computing for cyber-physical systems

The Journal of Supercomputing -     

Bandwidth scavenging for device coexistence in pervasive computing systems

Opportunistic Spectrum Access in a pervasive computing system can enable a set of secondary user devices to access unused spectrum, or whitespace, found between the transmissions of a set of primary user devices. The design objective for an efficient secondary user access strategy is to be able to “scavenge” spatio-temporally fragmented bandwidth while limiting the amount of disruption caused to the primary user devices. In this paper, we propose an access strategy which is based on measurement and modeling of the whitespace as perceived by the secondary user devices. A secondary user device continually monitors and models its surrounding whitespace, and then accesses the available spectrum so that the effective secondary throughput is maximized while the resulting disruption to the primary user devices is limited to a pre-defined bound. We first develop analytical expressions for the secondary throughput and primary disruption, and then perform ns2 based simulation experiments to validate its effectiveness under various topologies, user traffic profiles, and secondary user populations.     

Developing adaptable user interfaces for component-based systems

Software components are becoming increasingly popular design and implementation technologies that can be plugged and played to provide user-enhanceable software. However, developing software components with user interfaces that can be adapted to diverse reuse situations is challenging. Examples of such adaptations include extending, composing and reconfiguring multiple component user interfaces, and adapting component user interfaces to particular user preferences, roles and subtasks. We describe our recent work in facilitating such adaptation via the concept of user interface aspects, which support effective component user interface design and realisation using an extended, component-based software architecture.     

Understanding mass participatory pervasive computing systems for environmental campaigns

Participate was a 3-year collaboration between industry and academia to explore how mobile, Web and broadcast technologies could combine to deliver environmental campaigns. In a series of pilot projects, schools used mobile sensors to enhance science learning; visitors to an ecological attraction employed mobile phones to access and generate locative media; and the public played a mobile phone game that challenged their environmental behaviours. Key elements of these were carried forward into an integrated trial in which participants were assigned a series of environmental missions as part of an overarching narrative that was delivered across mobile, broadcast and Web platforms. These experiences use a three-layered structure for campaigns that draw on experts, local groups and the general public, who engage through a combination of playful characterisation and social networking.     

User preferences for adaptive user interfaces in health information systems

An adaptive user interface requires identification of user requirements. Interface designers and engineers must understand end-user interaction with the system to improve user interface design. A combination of interviews and observations is applied for user requirement analysis in health information systems (HIS). Then, user preferences are categorized in this paper as either data entry, language and vocabulary, information presentation, or help, warning and feedback. The user preferences in these categories were evaluated using the focus group method. Focus group sessions with different types of HIS users comprising medical staff (with and without computer skills) and system administrators identified each user group’s preference for the initial adaptation of the HIS user interface. User needs and requirements must be identified to adapt the interface to users during data entry into the system. System designers must understand user interactions with the system to identify their needs and preferences. Without this, interface design cannot be adapted to users and users will not be comfortable using the system and eventually abandon its use.     

Bond computing systems: a biologically inspired and high-level dynamics model for pervasive computing

Targeting at modeling the high-level dynamics of pervasive computing systems, we introduce bond computing systems (BCS) consisting of objects, bonds and rules. Objects are typed but addressless representations of physical or logical (computing and communicating) entities. Bonds are typed multisets of objects. In a BCS, a configuration is specified by a multiset of bonds, called a collection. Rules specify how a collection evolves to a new one. A BCS is a variation of a P system introduced by Gheorghe Paun where, roughly, there is no maximal parallelism but with typed and unbounded number of membranes, and hence, our model is also biologically inspired. In this paper, we focus on regular bond computing systems (RBCS), where bond types are regular, and study their computation power and verification problems. Among other results, we show that the computing power of RBCS lies between linearly bounded automata (LBA) and LBC (a form of bounded multicounter machines) and hence, the regular bond-type reachability problem (given an RBCS, whether there is some initial collection that can reach some collection containing a bond of a given regular type) is undecidable. We also study a restricted model (namely, B-boundedness) of RBCS where the reachability problem becomes decidable.     

Evolutionary design of user interfaces for workflow information systems

In this paper we argue that user interface design should evolve from iterative to evolutionary in order to support the user interface development life cycle in a more flexible way. Evolutionary design consists of taking any input that informs to the lifecycle at any level of abstraction and its propagation through inferior and superior levels (vertical engineering) as well as the same level (horizontal engineering). This lifecycle is particularly appropriate when requirements are incomplete, partially unknown or to be discovered progressively. We exemplify this lifecycle by a methodology for developing user interfaces of workflow information systems. The methodology involves several models (i.e., task, process, workflow, domain, context of use) and steps. The methodology applies model-driven engineering to derive concrete user interfaces from a workflow model imported into a workflow management system in order to run the workflow. Instead of completing each model step by step, any model element is either derived from early requirements or collected in the appropriate model before being propagated in the subsequent steps. When more requirements are elicited, any new element is added at the appropriate level, consolidated with the already existing elements, and propagated to the subsequent levels. A workflow editor has been developed to support the methodology.     

Adaptive offloading for pervasive computing

Delivering a complex application on a resource-constrained mobile device is challenging. An adaptive offloading system enables dynamic partitioning of the application and efficient offloading of part of its execution to a nearby surrogate. To deliver pervasive services without modifying the application or degrading its fidelity, we propose an adaptive offloading system that includes two key parts: a distributed offloading platform and an offloading inference engine. There are two important decision-making problems for adaptive offloading: adaptive offloading triggering and efficient application partitioning.     

Prototypes in pervasive computing

In product design, prototypes - approximations of a product along some dimensions - are the essential medium for information, interaction, integration, and collaboration. Information appliances such as mobile phones, digital cameras, and music players are a growing area of ubiquitous computing. Designers currently create two separate sets of prototypes: "looks-like" prototypes that show only the device's form (the atoms) and "works-like" prototypes that use a computer display to demonstrate the interaction (the bits). Because of the required skill and time investment, designers don't build comprehensive prototypes that join form and function until late in development.     

普适计算的可信研究*

随着应用规模的不断扩展以及具有无处不在性和便捷性的普适计算模式的特点,对普适计算环境下的可信保障提出了更高的要求。普适计算的可信保证是无时无处不在而又不可见的计算方式得以实施的重要保障,是普适计算领域的研究热点。从访问控制、隐私保护和容错三个方面阐述了普适计算的可信技术,并指出了该领域的未来研究发展趋势。     

The Light-Wall: tangible user interfaces for learning systems thinking

This paper presents the design of the Light-Wall, a tangible user interface aimed at teaching children the core principles of systems thinking. This document presents the design problem, process and solution.     

面向普适计算的界面自适应的研究

针对普适计算环境下由于设备形态的多样性而提出的用户界面转化问题,提出了基于Java和XML的一种解决方案.首先提出了整个系统的概念模型,然后对主要部分给出了具体的分析和实现,包括：用XML描述图形界面、编写XSLT（可扩展样式表语言转换）样式表、读取XML和XSLT样式表、编写Java servlet.最后,对将来需要解决的问题进行了探讨和展望.     

Multimedia technology for pervasive computing environment

With the emerging multimedia techniques which can be used for various pervasive and ubiquitous applications such as healthcare, environmental monitoring, security and surveillance, there are a number of important challenges that arise when multimedia transmits in this kind of pervasive computing environments. This special issue is called for high-quality, up-to-date related multimedia technology for pervasive computing environment. In this special issue, we have accepted only nine high-quality papers. We expect that this special issue will be a trigger for further related research and technology improvements in multimedia technology for pervasive computing environment.     

Situation-based testing for pervasive computing environments

A challenge for designing pervasive computing systems, particularly for indoor sensor-rich environments, is the complexity of causal relationships between contextual inputs, exhibited system behaviour, and overall appropriateness of resulting outcomes. Two key challenges faced by designers when testing these systems lie in the difficulty of monitoring the deployment environment for inappropriate outcomes and subsequently tracing the physical and digital causal factors leading to specific situations. This paper presents InSitu, a situation-based testing approach that applies generalised situation specifications to a global representation of simulated environment state to detect instances of specified situations. An access control case study demonstrates the modelling capabilities of InSitu and notes the importance of the overlap, exclusivity, and subsumption relationships between situation specifications in order to achieve informative results.     

Data-centric middleware for context-aware pervasive computing

The complexity of developing and deploying context-aware pervasive-computing applications calls for distributed software infrastructures that assist applications to collect, aggregate, and disseminate contextual data. In this paper, we motivate a data-centric design for such an infrastructure to support context-aware applications. Our middleware system, Solar, treats contextual data sources as stream publishers. The core of Solar is a scalable and self-organizing peer-to-peer overlay to support data-driven services. We describe how different services can be systematically integrated on top of the Solar overlay and evaluate the resource discovery and data-dissemination services. We also discuss our experience and lessons learned when using Solar to support several implemented scenarios. We conclude that a data-centric infrastructure is necessary to facilitate both the development and deployment of context-aware pervasive-computing applications.     

Reconfigurable context-sensitive middleware for pervasive computing

Context-sensitive applications need data from sensors, devices, and user actions, and might need ad hoc communication support to dynamically discover new devices and engage in spontaneous information exchange. Reconfigurable Context-Sensitive Middleware facilitates the development and runtime operations of context-sensitive pervasive computing software.     

Optimising context data dissemination and storage in distributed pervasive computing systems

Context management systems are expected to administrate large volumes of spatial and non-spatial information in geographical disperse domains. In particular, when these systems cover wide areas such as cities, countries or even the entire planet, the design of scalable storage, retrieval and propagation mechanisms is paramount. This paper elaborates on mechanisms that address advanced requirements, including support for distributed context databases management; efficient query handling; innovative management of mobile physical objects and optimization strategies for distributed context data dissemination. These mechanisms establish a robust spatially-enhanced distributed context management framework that has already been designed and carefully implemented and thoroughly evaluated.     

Location privacy in pervasive computing

As location-aware applications begin to track our movements in the name of convenience, how can we protect our privacy? This article introduces the mix zone-a new construction inspired by anonymous communication techniques-together with metrics for assessing user anonymity. It is based on frequently changing pseudonyms.