普适计算中间件技术的研究与进展

当前，普适计算已经成为计算机科学中一个极具活力和影响力的研究领域。普适计算环境规模很大并且具有高度异构性，如网络架构的异构性、硬件平台的异构性、操作系统的异构性、应用服务的异构性等，而普适计算中间件技术可以解决异构性和跨平台特征，提供不同服务的集成应用，因此成为普适计算中的一个研究热点。基于此，本文对于目前国外关于普适计算中间件技术的研究现状做了一个总结；通过分析和比较，给出了普适计算中间件的设计原则；探讨了普适计算中间件技术的未来发展方向。     

From battlefields to urban grids: New research challenges in ad hoc wireless networks

There has been much talk over the past two decades about commercialization of the mobile ad hoc network (MANET) technology. Potential ad hoc network applications with some commercial appeal are now finally emerging, “drafted” by the enormously successful wireless LAN technology. Closely coupled to commercial applications and critically dependent on commercial ad hoc networks will be the “pervasive computing” applications. Since military and civilian emergency MANETs have been around for over three decades, and since the Government has continuously supported MANET research for as many years, it may seem natural to assume that all the research has already been done and that commercial MANETs can be deployed by simply leveraging the military and civilian research results. Unfortunately, there is a catch. Commercial MANETs (and therefore pervasive computing applications) will evolve in a way totally different from their military counterparts. Most importantly, they will start small, and will initially be tethered to the Internet. They will be extremely cost-aware. They will also need to cater to a variety of different applications. This is in sharp contrast with the large scale, autonomous, special purpose and cost insensitive military networks. In this paper we review a typical “battlefield” MANET application and contrast it to two emerging commercial MANET scenarios—the urban vehicle grid and the Campus network. We compare characteristics and design goals and make the case for new research to help kick off commercial MANETs. In particular we argue that P2P technology will be critical in the early evolution of commercial MANETs and identify research directions for P2P MANETs.     

普适计算环境下的虚拟机技术研究

普适计算环境中资源和服务利用率较低,传统应用程序在该环境下无法兼容。为此,提出一种适用于普适计算环境的虚拟机技术。使用设备请求代理屏蔽复杂的普适计算网络环境,对上层应用提供统一硬件平台,支持多个普适计算应用同时运行。实验结果表明,该虚拟化技术能兼容传统应用,提高普适计算资源和服务的利用率。     

Pervasive computing at scale: Transforming the state of the art

The remarkable recent progress in computing power, sensors and embedded devices, smart phones, wireless communications and networking technologies, combined with emerging data mining techniques, cloud computing and social networking paradigms has enabled us to create pervasive computing systems and services with diverse applications and global accessibility. In this paper, we assess the current state of the art of pervasive computing at scale (PeCS) and look ahead to future directions the field can pursue together with challenges it will need to overcome.     

Activity-Aware Computing for Healthcare

In this article, we introduce activity-aware computing, which uses activity-based computing to enhance pervasive environments in two ways: to help users associate resources and services with activities, resulting in seamless interaction with those resources and services, and to enable pervasive environments to automatically infer activities and thus opportunistically offer services that support the user's current goal. Thus, activity-aware applications persuade users to commit themselves to the technology, moving from a paradigm of activity-based ";interaction"; toward one of activity-aware ";engagement"; with a computationally augmented environment. We present a set of tools for developing activity-aware applications, including a computational representation of human activities that we defined using data from a hospital case study we conducted. We also used the data to create an activity recognition approach and a set of design principles for developing activity-aware applications. The mobile activity monitor we designed to create a wearable connection between patients and nurses exemplifies our design principles.     

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.     

IT convergence security

A recent emerging issue in information technology is the convergence of different kinds of applications. Convergence brings a user-centric environment to provide computing and communication services. In order to realize IT advantages, it requires the integration of security and data management to be suitable for pervasive computing environments. Security convergence refers to the convergence of two historically distinct security functions—physical security and information security—within enterprises; both are integral parts of any coherent risk management program. In this special issue, we have discussed current IT-Converged security issues, security policy and new security services which will lead to successful transfer smart space which is a new paradigm of future.     

一种面向普适计算的自适应软件平台的设计与实现

普适计算的适应性特征带来了有必要在软件平台层面解决的一系列共性问题,包括如何定义所支持的自适应软件体系结构、如何为上层应用的自适应提供必要的公共服务、如何使平台自身可以适应多维资源受限环境等。针对这些挑战,提出了对普适计算设备/资源进行适应性抽象的自主单元的概念,在此基础上给出了面向普适计算的自适应软件平台UbiStar的系统架构及其核心机制的设计与实现,并对UbiStar平台对适应性软件所提供的支持机制进行了概括,最后对相关工作进行了分析与比较。     

Bringing network effects to pervasive spaces

We developed the Obje interoperability framework, a middleware technology that lets networked applications and services coordinate with each another-even when they know almost nothing about one other. We've implemented the current version of the Obje framework (version 4) in Java. It supports both Java and native mobile code and can be implemented in a variety of languages and platforms. It also runs on several platforms, including Windows, Mac OS X, Linux, and Windows PocketPC. Leveraging the Obje framework, we have been able to return to our focus of developing pervasive spaces to explore the human experience of pervasive computing.     

基于普适计算的文化网格

普适计算是一种将嵌入式系统、网络计算、移动计算技术相结合形成一个以人为本的信息服务智慧空间环境,人们能够在智慧空间中自由活动,享受无所不在的信息服务。网格计算的目标是使得网络上的各种资源能象电力网络一样将计算和信息的使用变得简单易用。在普适计算与网格计算的支持下,智慧空间可以不断拓展成为按需服务的信息文化基础设施网格,即文化网格。探讨了文化网格的体系结构、层次模型及关键技术。     

Smart devices and spaces for pervasive computing

Applications and services for pervasive computing have been dramatically grown and have contributed extensively to our daily experiences in recent years. Smart systems, devices, and spaces are proactive for ubiquitous and pervasive computing. Smart information technology (IT) is also an outcome of the state of the art and novel mobile and ubiquitous computing technologies that include highly capable handheld device, pervasive and personal device, etc. This special issue will be a trigger for further related research and technology improvements in pervasive and ubiquitous computing using smart devices and services. This special issue called for original papers describing the latest developments, trends, and solutions of smart devices and spaces for pervasive computing including real-time operating systems (OS), tiny OS and middleware supports, mobile system performance, trustworthy Internet and communications, agents and mobile and pervasive services, among others. In particular, this special issue focuses on a remote control and media-sharing system, flash storage-based smart system, heterogeneous mobile OS, and prediction and auto-execution system for pervasive computing.     

H-Trust: A Group Trust Management System for Peer-to-Peer Desktop Grid

Peer-to-Peer Desktop Grid (P2PDG) has emerged as a pervasive cyber-infrastructure tackling many large-scale applications with high impacts. As a burgeoning research area, P2PDG can support numerous applications, including scientific computing, file sharing, web services, and virtual organization for collaborative activities and projects. To handle trustworthiness issues of these services, trust and reputation schemes are proposed to establish trust among peers in P2PDG. In this paper, we propose a robust group trust management system, called H-Trust, inspired by the H-index aggregation technique. Leveraging the robustness of the H-index algorithm under incomplete and uncertain circumstances, H-Trust offers a robust personalized reputation evaluation mechanism for both individual and group trusts with minimal communication and computation overheads. We present the H-Trust scheme in five phases, including trust recording, local trust evaluation, trust query phase, spatial-temporal update phase, and group reputation evaluation phases. The rationale for its design, the analysis of the algorithm are further investigated. To validate the performance of H-Trust scheme, we designed the H-Trust simulator HTrust-Sim to conduct multi-agent-based simulations. Simulation results demonstrate that H-Trust is robust and can identify and isolate malicious peers in large scale systems even when a large portion of peers are malicious.     

Ambient multimodality: towards advancing computer accessibility and assisted living

The aim of this paper is to point out the benefits that can be derived from research advances while implementing concepts such as ambient intelligence and ubiquitous/pervasive computing for promoting universal access in the information society, that is, for contributing to enable everybody, especially people with physical disabilities, to have easy access to all computing resources and information services that the upcoming worldwide information society will soon make available to the general public as well as to expert users. Following definitions of basic concepts relating to multimodal interaction, the significant contribution of multimodality to developing universal access is briefly discussed. Then, a short state of the art in ambient intelligence research is presented, including references to some major research projects either in progress or recently completed. The last section is devoted to bringing out the potential contribution of advances in ambient intelligence research and technology to the improvement of computer access for physically disabled people, hence, to the implementation of universal access. This claim is mainly supported by the following observations: (1) most projects are aiming at implementing ambient intelligence focus research efforts on the design of new interaction modalities and flexible/adaptive multimodal user interfaces; outcomes of these projects may contribute to improving computer access for users with physical disabilities; (2) such projects target applications meant to support users in a wide range of daily activities which will have to be performed simultaneously with the related supporting computing tasks; therefore, users will be placed in situational contexts where they will be confronted with similar difficulties to those encountered by physically disabled users, since they will have to share out their perceptual and motor capabilities between one or several daily activities and the computing tasks meant to support them; (3) ambient intelligence applications being intended for the general public, a wide range of interaction devices supporting a great variety of input and output modalities will be available, making it possible to provide physically disabled users with appropriate human–computer interaction means tailored to their individual needs at a reasonable expense.     

WINES: Wired and Wireless Intelligent Networked Systems

The UK's Engineering and Physical Sciences Research Council launched its Wired and Wireless Intelligent Networked Systems program in 2004 to address research challenges in creating massive-scale ubiquitous and pervasive computing environments. WINES assumes an intelligent, pervasive information and communications technology environment would eventually emerge in which users experience a rich variety of heterogeneous services and systems, delivered through a wide range of devices.     

A comprehensive approach to model and use context for adapting applications in pervasive environments

With an increasing diversity of pervasive computing devices integrated in our surroundings and an increasing mobility of users, it will be important for computer systems and applications to be context-aware. Lots of works have already been done in this direction on how to capture context data and how to carry it to the application. Among the remaining challenges are to create the intelligence to analyze the context information and deduce the meaning out of it, and to integrate it into adaptable applications. Our work focuses on these challenges by defining generic context storage and processing model and by studying its impact on the application core. We propose a reusable context ontology model that is based on two levels: a generic level and a domain specific level. We propose a generic adaptation framework to guarantee adaptation of applications to the context in a pervasive computing environment. We also introduce a comprehensive adaptation approach that involves content adaptation and presentation adaptation inline with the adaptation of the core services of applications. Our case study shows that the context model and the application adaptation strategies provide promising service architecture.     

Supporting pervasive computing applications with active context fusion and semantic context delivery

Future pervasive computing applications are envisioned to adapt the applications’ behaviors by utilizing various contexts of an environment and its users. Such context information may often be ambiguous and also heterogeneous, which make the delivery of unambiguous context information to real applications extremely challenging. Thus, a significant challenge facing the development of realistic and deployable context-aware services for pervasive computing applications is the ability to deal with these ambiguous contexts. In this paper, we propose a resource optimized quality assured context mediation framework based on efficient context-aware data fusion and semantic-based context delivery. In this framework, contexts are first fused by an active fusion technique based on Dynamic Bayesian Networks and ontology, and further mediated using a composable ontological rule-based model with the involvement of users or application developers. The fused context data are then organized into an ontology-based semantic network together with the associated ontologies in order to facilitate efficient context delivery. Experimental results using SunSPOT and other sensors demonstrate the promise of this approach.     

一种普适环境下面向服务的事务处理模型

普适环境具有高移动、极端异构、高自治和开放性的特点,普适环境下的服务组合因其突出的动态性问题,为保证对整个服务运行结果的可靠性和一致性,引入事务处理的机制来进行管理。提出一种在普适环境下面向服务的事务处理模型,在服务的发现、组合及运行中引入事务机制来协调管理,保证了服务组合的可靠一致性,并讨论了模型的系统架构和各模块组成,及应用场景。     

服务发现技术中的服务描述和服务匹配技术

普及计算环境中的设备和应用需要通过服务发现来获得其它设备和应用所提供的服务。在服务发现技术中,服务描述、需求描述和服务匹配是迫切需要解决的关键问题。但由于服务和需求的多样性和复杂性,以及普及计算环境的动态性和异构性,使这些问题更加困难和复杂。所以,寻找一种灵活高效而又准确的方式来进行服务描述、需求描述,进而进行服务匹配,具有非常重要的意义。对现有多种服务发现系统中的服务描述需求描述和服务匹配技术进行比较分析,指出了现有解决方案的一些不足,并对未来的研究进行了展望。     

支持感知上下文网络操作平台中间件的研究

普适计算的出现将大大改变人类与各种设备交互的方式。支持感知上下文计算的网络操作平台是普适计算环境下重要的应用支撑平台,为基于传感器网络的应用提供操作服务。操作平台以中间件为核心,采用XMLWebServices技术。文章以满足包括智能家居普适上下文应用需求的网络操作平台为基础,介绍该网络操作平台的机制、层次结构和数据模型的研究,并实现了基于该平台模型的XMLWebServices中间件应用方案。     

Cloud Computing: Distributed Internet Computing for IT and Scientific Research

Cloud computing is a disruptive technology with profound implications not only for Internet services but also for the IT sector as a whole. Its emergence promises to streamline the on-demand provisioning of software, hardware, and data as a service, achieving economies of scale in IT solutions' deployment and operation. This issue's articles tackle topics including architecture and management of cloud computing infrastructures, SaaS and IaaS applications, discovery of services and data in cloud computing infrastructures, and cross-platform interoperability. Still, several outstanding issues exist, particularly related to SLAs, security and privacy, and power efficiency. Other open issues include ownership, data transfer bottlenecks, performance unpredictability, reliability, and software licensing issues. Finally, hosted applications' business models must show a clear pathway to monetizing cloud computing. Several companies have already built Internet consumer services such as search, social networking, Web email, and online commerce that use cloud computing infrastructure. Above all, cloud computing's still unknown "killer application" will determine many of the challenges and the solutions we must develop to make this technology work in practice.