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.     

Collaborative joins in a pervasive computing environment

We present a collaborative query processing protocol based on the principles of Contract Nets. The protocol is designed for pervasive computing environments where, in addition to operating on limited computing and battery resources, mobile devices cannot always rely on being able to access the wired infrastructure. Devices, therefore, need to collaborate with each other in order to obtain data otherwise inaccessible due to the nature of the environment. Furthermore, by intelligently using answers cached by peers, devices can reduce their computation cost. We show the effectiveness of our approach by evaluating performance of devices querying for data while moving in a citylike environment.Received: 28 July 2003, Accepted: 26 March 2004, Published online: 8 July 2004Edited by: K. Ramamritham     

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.     

基于普适计算的军用智能终端系统模型研究

普适计算的出现将大大改善人类与各种设备的交互方式,基于普适计算理论,运用Web Services和多agent技术,构建出新型军用智能终端系统模型,并从系统体系结构和智能交互两方面详细阐述了其工作原理与技术优势,为普适计算理论在未来军队信息化建设中的运用进行了初步探索和研究.     

基于普适计算的虚拟场景自适应网络发布研究

针对移动设备访问三维虚拟场景受到网络带宽和终端计算能力的制约,使得在线利用虚拟现实进行移动学习效率不高,基于此提出了基于普适计算的自适应优化选择技术.对三维实体进行本体语义描述,建立相应的优化模型.在此基础上通过WURFL对手持移动设备进行采样获取设备参数,对参数进行分析从而建立普适规则,利用普适计算进行自适应优化选择.测试结果表明,经过自适应选择后手持移动设备荻取三维虚拟场景资源的速度和效率得到明显提高.     

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).     

Using pervasive computing to deliver elder care

The Elite Care Information Technology Group has deployed a system with many elements of pervasive computing, including portable and wearable devices and wireless networking, to create intelligent and responsive work and living spaces for the elderly in a residential setting. Elite Care based the setting's layout on an apartment complex rather than a hospital with its hallways and rooms. By using a social care model that has the staff making house calls rather than doctors making rounds, the residents continue to live as normally as they can. In this scheme, pervasive sensors and staff assist residents in maintaining their independence, offering assistance as necessary and using the pervasive sensors to monitor vital signs and health indicators. Elite Care has harnessed the technology in direct and important ways to construct a more humane and human world for its residents and staff.     

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.     

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.     

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。     

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.     

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.     

On data management in pervasive computing environments

This paper presents a framework to address new data management challenges introduced by data-intensive, pervasive computing environments. These challenges include a spatio-temporal variation of data and data source availability, lack of a global catalog and schema, and no guarantee of reconnection among peers due to the serendipitous nature of the environment. An important aspect of our solution is to treat devices as semiautonomous peers guided in their interactions by profiles and context. The profiles are grounded in a semantically rich language and represent information about users, devices, and data described in terms of "beliefs," "desires," and "intentions." We present a prototype implementation of this framework over combined Bluetooth and Ad Hoc 802.11 networks and present experimental and simulation results that validate our approach and measure system performance.     

Understanding identity exposure in pervasive computing environments

Various miniaturized computing devices that store our identity information are emerging rapidly and are likely to become ubiquitous in the future. They allow private information to be exposed and accessed easily via wireless networks. When identity and context information is gathered by pervasive computing devices, personal privacy might be sacrificed to a greater extent than ever before. People whose information is targeted may have different privacy protection skills, awareness, and privacy preferences. In this research, we studied the following issues and their relations: (a) identity information that people think is important to keep private; (b) actions that people claim to take to protect their identities and privacy; (c) privacy concerns; (d) how people expose their identity information in pervasive computing environments; and (e) how our RationalExposure model can help minimize unnecessary identity exposure. We conducted the research in three stages, a comprehensive survey and two in-lab experiments. We built a simulated pervasive computing shopping system, called InfoSource. It consisted of two applications and our RationalExposure model. Our data show that identity exposure decisions depended on participants’ attitudes about maintaining privacy, but did not depend on participants’ concerns or security actions that they claimed to have taken. Our RationalExposure model did help the participants reduce unnecessary disclosures.