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。     

Toward pervasive computing

Summary form only given. The fundamental principles that guide pervasive computing environment design evolved with distributed systems: local area networks, middleware, wide-area networks, the WWW. Over the years, ever smaller, portable computers came on the market and wireless networking technology evolved, leading to the emergence of mobile and wireless computing. Embedded computing gave us small devices, sensors and actuators, increasingly with communications capability. There are now substantial projects that demonstrate that sensor-rich environments, such as active buildings and cities, are feasible and will be deployed widely in the real world in the near future. This issue of Pervasive Computing describes several such projects.     

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.     

Ontology-enabled pervasive computing applications

Information technology's rapid evolution has made tremendous amounts of information and services available at our fingertips. However, we still face the frustration of trying to do simple things in the device- and application-rich environments where we live and work. Task computing is defined as computation to fill the gap between the tasks that users want to perform and the services that constitute available actionable functionality. To support task computing, we have implemented a Task Computing Environment including client environment, service discovery mechanism, and Semantic Web services and tools. TCE is composed of several components including STEER (Semantic Task Execution EditoR), White Hole, and PIPE (Pervasive Instance Provision Environment).     

Garden variety pervasive computing

Unseen, a knowledge-sharing experience machine for outdoor public spaces, continuously collects real-time data on plants, insects, and animals through a multicamera vision system. Unseen's interpretation and sharing of this data invites visitors to reconsider and question their preconceptions about wildlife. We describe the conception, implementation, and evaluation of a knowledge-sharing system for outdoor spaces. Like a nature interpretation center, our fully automated, machine vision-based outdoor installation shows visitors interesting facts about the area they are visiting.     

Application mobility in pervasive computing: A survey

Pervasive computing applications often need to maintain uninterrupted computing experiences when users move across devices. This advanced feature, recognized as application mobility, brings many challenges to the pervasive computing community. For a better understanding of the challenges and existing approaches to application mobility, this paper surveys related work with a classification and comparison framework established along four dimensions of design concerns in application migration: temporal, spatial, entity and other concerns. Through this survey this paper attempts to provide a systematic reference for developers to leverage off among different migration strategies for seamless application mobility. Moreover, it sheds some light on future work directions.     

Middleware for pervasive computing: A survey

The rapidly emerging area of pervasive computing faces many challenging research issues critical to application developers. Wide heterogeneity of hardware, software, and network resources pose veritable coordination problems and demand thorough knowledge of individual elements and technologies. In order to ease this problem and to aid application developers, different middleware platforms have been proposed by researchers. Though the existing middleware solutions are useful, they themselves have varied features and contribute partially, for context, data, or service management related application developments. There is no single middleware solution that can address a majority of pervasive computing application development issues, due to the diverse underlying challenges. In this survey paper, we identify different design dimensions of pervasive computing middleware and investigate their use in providing various system services. In-depth analysis of the system services have been carried out and middleware systems have been carefully studied. With a view to aid future middleware developers, we also identify some challenging open research issues that have received little or no attention in existing middleware solutions.     

Project Aura: toward distraction-free pervasive computing

The most precious resource in a computer system is no longer its processor, memory, disk, or network, but rather human attention. Aura aims to minimize distractions on a user's attention, creating an environment that adapts to the user's context and needs. Aura is specifically intended for pervasive computing environments involving wireless communication, wearable or handheld computers, and smart spaces. Human attention is an especially scarce resource in such environments, because the user is often preoccupied with walking, driving, or other real-world interactions. In addition, mobile computing poses difficult challenges such as intermittent and variable-bandwidth connectivity, concern for battery life, and the client resource constraints that weight and size considerations impose. To accomplish its ambitious goals, research in Aura spans every system level: from the hardware, through the operating system, to applications and end users. Underlying this diversity of concerns, Aura applies two broad concepts. First, it uses proactivity, which is a system layer's ability to anticipate requests from a higher layer. In today's systems, each layer merely reacts to the layer above it. Second, Aura is self-tuning: layers adapt by observing the demands made on them and adjusting their performance and resource usage characteristics accordingly. Currently, system-layer behavior is relatively static. Both of these techniques will help lower demand for human attention.     

Trust-based security in pervasive computing environments

Traditionally, stand-alone computers and small networks rely on user authentication and access control to provide security. These physical methods use system-based controls to verify the identity of a person or process, explicitly enabling or restricting the ability to use, change, or view a computer resource. However, these strategies are inadequate for the increased flexibility that distributed networks such as the Internet and pervasive computing environments require because such systems lack central control and their users are not all predetermined. Mobile users expect to access locally hosted resources and services anytime and anywhere, leading to serious security risks and access control problems. We propose a solution based on trust management that involves developing a security policy, assigning credentials to entities, verifying that the credentials fulfill the policy, delegating trust to third parties, and reasoning about users' access rights. This architecture is generally applicable to distributed systems but geared toward pervasive computing environments     

基于上下文的普适计算角色访问控制模型

针对普适计算访问控制上下文感知的特点,分析了现有扩展RBAC模型的不足,提出了基于上下文的角色访问控制模型(CRBAC).模型定义了可执行角色集,引入由时间状态,位置信息、用户信任值组成的上下文信息,由上下文信息激活可执行角色集,并以此代表用户最终获得的权限,这样用户就只能在一定的上下文中才可以执行某个角色的某个权限,实现了细粒度的动态授权.然后分别对此模型下单用户和多用户的访问控制过程进行了描述,最后利用有限状态机验证了模型的安全性.     

Service discovery in pervasive computing environments

Pervasive computing environments pose unique service discovery challenges. We have developed a taxonomy of existing protocols as a basis for analyzing their approaches and identifying problems and open issues relative to service discovery in pervasive computing environments.     

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.     

Situation identification techniques in pervasive computing: A review

Pervasive systems must offer an open, extensible, and evolving portfolio of services which integrate sensor data from a diverse range of sources. The core challenge is to provide appropriate and consistent adaptive behaviours for these services in the face of huge volumes of sensor data exhibiting varying degrees of precision, accuracy and dynamism. Situation identification is an enabling technology that resolves noisy sensor data and abstracts it into higher-level concepts that are interesting to applications. We provide a comprehensive analysis of the nature and characteristics of situations, discuss the complexities of situation identification, and review the techniques that are most popularly used in modelling and inferring situations from sensor data. We compare and contrast these techniques, and conclude by identifying some of the open research opportunities in the area.     

Affective e-Learning in residential and pervasive computing environments

This article examines how emerging pervasive computing and affective computing technologies might enhance the adoption of ICT in e-Learning which takes place in the home and wider city environment. In support of this vision we describe two cutting edge ICT environments which combine to form a holistic connected future learning environment. The first is the iSpace, a specialized digital-home test-bed that represents the kind of high-tech, context aware home-based learning environment we envisage future learners using, the second a sophisticated pervasive e-Learning platform that typifies the educational delivery platform our research is targeting. After describing these environments we then present our research that explores how emotion evolves during the learning process and how to leverage emotion feedback to provide adaptive e-Learning system. The motivation driving this work is our desire to improve the performance of the educational experience by developing learning systems that recognize and respond appropriately to emotions exhibited by learners. Finally we report on the results about the emotion recognition from physiological signals which achieved a best-case accuracy rate of 86.5% for four types of learning emotion. To the best of our knowledge, this is the first report on emotion detection by data collected from close-to-real-world learning sessions. We also report some finding about emotion evolution during learning, which are still not enough to validate Kort’s learning spiral model.

Video sketches: exploring pervasive computing interaction designs

Some industry designers have used video scenarios - short movies that show how users might actually interact with a product. However, cost and production issues undermine this method's usefulness. To address this challenge, the author and his students have developed a new method called video sketches. Although similar to video scenarios, video sketches significantly lower the production threshold by replacing video footage with photos. Unlike traditional video, video sketches require tools that most design students have on hand. Students used consumer-level digital still cameras and laptops as their main tools. They composited the images using standard graphic design software and constructed the linear story using low-end video-editing software. Audio production presented the most difficult challenge. Students produced their video sketches following the traditional three-phase (preproduction, production, and postproduction) process. Traditional cinematography issues also apply to making video sketches.     

PvcwCORBA:普适计算环境中间件的实现

针对普适环境的平台的多样性、资源的有限性、设备的移动性和应用高性能要求等需求,提出了其中间件的设计和实现方法,并据此构建了pvcwCORBA。通过试验验证了pvcwCORBA作为支持无线接入功能的高性能、嵌入式CORBA,能够适应普适计算环境的要求。     

普适计算中网络可生存性及系统设计*

主要就普适计算下无边界网络系统的可生存性问题进行分析,然后介绍了可生存系统设计的两种设计方法,并对两种设计方法进行对比分析.     

PICO: a middleware framework for pervasive computing

The pervasive information community organization is a framework for creating mission-oriented dynamic communities of autonomous software entities that perform tasks for users and devices. PICO's telemedicine example scenario demonstrates its potential as a simple, unique, and versatile middleware framework for pervasive computing.