Context-aware inference in ubiquitous residential environments

Residential ubiquitous computing environments have focused on interconnecting environmental controls using a home network and the management of sensor data rather than a context-aware inference. Building upon previous research, this paper proposes a novel sensor-based context-aware system with a focus on three inference processes: rule, inference and pattern driven. Using pattern data derived from five families for a working week and establishing rules and inferences, the proposed context-aware system is demonstrated using electrical lighting as an example. The processes to develop an intelligent house are described so as to ameliorate personalized services in response to inhabitants’ needs.     

Location-based services in ubiquitous computing environments

This paper presents a framework for providing dynamically deployable services in ubiquitous computing settings. The goal of the framework is to provide people, places, and objects with computational functionalities to support and annotate them. Using RFID-based tracking systems, the framework detects the locations of physical entities, such as people or things, and deploys services bound to the entities at proper computing devices near where they are located. It enables location-based and personalized information services to be implemented as mobile agents and operated at stationary or mobile computing devices, which are at appropriate locations, even if the services do not have any location-information. This paper presents the rationale, design, implementation, and applications of our prototype infrastructure.     

Sleeping situation monitoring system in ubiquitous environments

In recent years, because of the development of ubiquitous technology in health care, research is actively progress. We describe a sleeping situation monitoring system, created to support home healthcare services. We discuss the method we used to develop the system and how to use the sleep activity monitor to support home health care. Information about the sleeping situation is collected from motion detection, sound, and vibration sensors. And this information is based on real-time processing, we used the TMO (Time-trigger and Message-trigger Object) schema and TMOSM (TMO Support Middleware) into the development software environment of the healthcare application. To verify the practical use of sleeping situation information as recorded by the system discussed in this paper, we relate an example of the monitoring of a sleeping situation using our system, and we describe the results of an experimental evaluation.     

Toward ubiquitous environments for mobile users

A computational paradigm that lets processes migrate with users would support truly ubiquitous computing environments. The article investigates the technical problems that must be solved to accommodate this model and examines some systems that are addressing the problems now. The review of current systems addressing these issues reveals that it is now possible to engineer a system in which the user's entire environment is available wherever and whenever it is required. However, the provision of such an environment represents a considerable engineering effort and many significant choices. At the University of Stirling, we are currently investigating these choices in the construction of a ubiquitous environment based on Java     

面向普适环境的协同设计框架研究

提出了一种面向普适环境的协同设计框架。该协同设计框架在现有分布协同对象计算技术和网格服务的基础上,引入了普适环境“随时随地”和“透明”的思想,巧妙地把协同设计技术融入第三代计算环境中。该文讨论了普适计算的相关理论,也涉及了网格计算的相关技术。并且建立了第三代计算环境下分布式协同设计模型。该框架能够很好地利用各种网络资源,随时随地的进行产品设计开发。最后简要介绍该框架在在自主开发的HUST-CAIDS中的初步应用。     

面向普适环境的上下文感知中间件研究

针对普适环境下上下文感知计算需求,引入广义模型化理论,建立了一种面向通用环境资源的上下文信息数据模型;在此基础上,提出了上下文感知中间件体系框架,并详细阐述了其构件化的实施方案。该中间件平台的上下文获取层能够封装各类感知器捕获的资源信息,中间处理层负责信息的管理、推理和聚合,基于门面模式的上下文访问层提供同步和异步相结合的上下文信息统一访问入口。通过实验测试了平台的时间损耗,表明该中间件可提供通用的上下文感知服务且具有较好的系统性能。     

Facilitating resource sharing and selection in ubiquitous multi-user environments

Mobile technologies have increased the interest of industry and academia in providing users with information and services anytime and anywhere. Some services are customized according to the users’ characteristics, attempting to create ubiquitous environments that enable such users to share and discover resources. However, research that addresses the creation of these environments is scant. In this article, we go further than single-user pervasive systems, by developing a support that manages shared resources in ubiquitous multi-user environments. Our contribution is a semantic matchmaking service capable of finding the most suitable resources that satisfy the users’ requirements. This service processes the users’ requests, their context, and the community participating in the resource sharing process, by respecting restrictions, the natural interaction among participants, and the changes that this interaction produces. We model the environment, shared resources, and users as dynamic entities that generate new information, which might affect the availability states of such resources. These states have been defined through the Contextual-Graphs formalism to incorporate new knowledge that can refine, extend, or customize such states, according to the users’ habits. Our matchmaking service has been deployed across the Computer Science Department of CINVESTAV-IPN research center, where it has been validated by means of several test cases.     

Self-organized multi-camera network for ubiquitous robot deployment in unknown environments

In this paper, we present a multi-agent system based on a network of intelligent cameras for the easy and fast deployment of mobile robots in unknown environments. The cameras are able to detect events which require the presence of the robots, calculate routes of cameras through which the robots can navigate, and support this navigation. A route is a list of cameras connected by neighbourhood relationships: the cameras may be neighbours if their Fields of View (FOVs) overlap, or if there exists a passable path among them (if their FOVs do not overlap). In our system, all coordination processes are fully distributed, based only on local-interactions, and self-organization. Our system is robust and redundant, and scales well with the size of the environment and the number of cameras and robots. Finally, it is flexible to the environment, to the number of agents used, and to their disposition. In the experimental section, we show the performance of this system in different real world settings.     

A QoS-driven approach for service-oriented device anycasting in ubiquitous environments

The vision of pervasive computing is to let users enjoy ICT-enabled services in an “any time, anywhere, on any device” manner. It aims to supply ubiquitous services through communications among a set of devices deployed in a ubiquitous environment. Due to the diverse QoS needs of different kinds of ubiquitous services and users, it is a critical challenge to select an optimal set of devices with the objective of achieving service-specific QoS goals like low packet loss, short packet delay, and high energy efficiency. In this paper, the problem is first formulated as the service-oriented device anycasting problem (SDAP) and then proved as an NP-complete problem. By adopting a tree-based service representation model, Basu et al. proposed the dynamic task-embedding anycasting (DTA) approach. This approach effectively solves the SDAP in a distributed way. However, the service quality is likely sacrificed because the tree scheme does not sufficiently describe a ubiquitous service. In this paper, we propose a novel approach called the service-oriented device anycasting (SDA) approach that adopts a graph-based service representation model called the service profile (SP). By introducing a layered structure into the SP, the SDA approach can reach a compromise between service quality and computational complexity. In addition, the QoS-driven utility function is proposed to quantify service quality by matching the capabilities of heterogeneous devices to various QoS needs. Finally, the simulation results show that the SDA approach outperforms the DTA approach by saving roughly 20% of device energy and prolonging the network lifetime. Packet loss and packet delay are also improved by roughly 25% and 8%, respectively. The advantage of the SDA approach is more obvious in environments with highly mobile devices and multiple users.     

Prototyping and analysing ubiquitous computing environments using multiple layers

If ubiquitous computing (ubicomp) is to enhance physical environments then early and accurate assessment of alternative solutions will be necessary to avoid costly deployment of systems that fail to meet requirements. This paper presents APEX, a prototyping framework that combines a 3D Application Server with a behaviour modeling tool. The contribution of this framework is that it allows exhaustive analysis of the behaviour models that drive the prototype while at the same time enabling immersive exploration of a virtual environment simulating the proposed system. The development of prototypes is supported through three layers: a simulation layer (using OpenSimulator); a modelling layer (using CPN Tools) and a physical layer (using external devices and real users). APEX allows movement between these layers to analyse different features, from user experience to user behaviour. The multi layer approach makes it possible to express user behaviour in the modelling layer, provides a way to reduce the number of real users needed by adding simulated avatars, and supports user testing of hybrids of virtual and real components as well as exhaustive analysis. This paper demonstrates the approach by means of an example, placing particular emphasis on the simulation of virtual environments, low cost prototyping and the formal analysis capabilities.     

An incentive compatible reputation mechanism for ubiquitous computing environments

The vision of ubiquitous computing is becoming a reality thanks to the advent of portable devices and the advances in wireless networking technologies. It aims to facilitate user tasks through seamless utilization of services available in the surrounding environments. In such distributed environments featuring openness, interactions such as service provision and consumption between entities that are unknown or barely known to each other, are commonplace. Trust management through reputation mechanism for facilitating such interactions is recognized as an important element of ubiquitous computing. It is, however, faced by the problems of how to stimulate reputation information sharing and enforce honest recommendation elicitation. We present in this paper an incentive compatible reputation mechanism to facilitate the trustworthiness evaluation of entities in ubiquitous computing environments. It is based on probability theory and supports reputation evolution and propagation. Our reputation mechanism not only shows robustness against lies, but also stimulates honest and active recommendations. The latter is realized by ensuring that active and honest recommenders, compared to inactive or dishonest ones, can obtain the most number of honest (helpful) recommendations and thus suffer the least number of wrong trust decisions, as validated by simulation based evaluation. The proposed reputation mechanism is also implemented as part of a QoS-aware Web service discovery middleware and evaluated regarding its overhead on service discovery latency.     

普适环境中一种安全协议的设计及分析

普适环境需要满足“透明”“ 无需人干预的”性质,提出了一种普适计算环境下的安全协议——SPUE。它满足数据认证、数据新鲜性等安全特性,同时满足普适计算的“ 无需人干预的”性质。协议采用非对称密钥与对称密钥相结合的方法,在解决普适计算能量、计算能力限制同时增加了安全性,使其更适合于普适计算环境;同时运用通信顺序进程(CSP)方法对安全协议建模,采用FDR对模型进行检测,确保了协议能够满足各项安全性能。     

A novel ANN-based service selection model for ubiquitous computing environments

How to choose an appropriate service from all the usable services regardless of user's location and heterogeneous architecture of underlying software and hardware infrastructure is the most important study content in ubiquitous computing domain. In order to overcome the shortcomings of blindness and randomicity in traditional and improved trust-mechanism-based service selection models, we propose a novel ANN-based (Artificial Neural Network) service selection model (called the ANNSS model). We adopt a novel method which according to the earlier information of the cooperation between the devices and the context information, an ANN-based evaluation standard for the service quality of service provider is given out so that user can acquire an effective guidance and choose the most appropriate service. At the same time, we improved the traditional BP algorithm based on three-term method (called the TTMBP algorithm) consisting of a learning rate (LR), a momentum factor (MF) and a proportional factor (PF) in order to satisfy the requirements of time issue in real-time system. The convergence speed and stability were enhanced by adding the proportional factor. The self-adjusting architecture method is adopted so that a moderate scale of neural network can be obtained. We have implemented the ANNSS algorithm in an actual power supply system for communication devices and fulfilled various simulations. The results of simulation show that the proposed service selection scheme is not only scalable but also efficient, and that the novel BP algorithm based on three-term has high convergence speed and good convergence stability. The novel service selection scheme superior to the traditional and improved trust-mechanism-based service selection scheme. The novel scheme can exactly choose a most appropriate service from many service providers and provide the most perfect service performance to users.     

普适环境下的模糊访问控制模型研究

现有的普适访问控制模型的研究都忽视了安全中存在的模糊性问题。在普适计算环境中上下文信息可能是不完备或者模糊的,因此由残缺或模糊的上下文信息推导授权结果就显得十分重要。在使用控制模型的基础上,提出了一个模糊的普适访问控制模型（fuzzy usage control models, FUCM）,给出了模型的形式化定义,并通过实例对模型的授权过程进行分析。结果表明新的模型能够对模糊的上下文信息进行授权决策,并具有更智能的授权能力,更适用于普适计算环境。最后,给出了模型实现的参考监视器体系结构。     

SARA: A service architecture for resource aware ubiquitous environments

Realizing the potential of pervasive computing will be predicated upon the availability of a flexible, mobility-aware infrastructure and technologies to support seamless service management, provisioning and delivery. Despite advances in routing and media access control technologies, little progress has been made towards large-scale deployment of services and applications in pervasive and ubiquitous environments. The lack of a fixed infrastructure, coupled with the time-varying characteristics of the underlying network topology, makes service delivery challenging. This paper addresses these challenges and presents SARA, a unified, overlay-based service architecture to support large-scale service and application deployment in pervasive and ubiquitous environments. We discuss the main functionalities of SARA and present the algorithms for object registration and discovery. SARA also considers the mobility of the nodes in the network and provides a mechanism by which this can be incorporated into the framework. Finally, the proposed architecture was evaluated using simulations and the results show that the architecture performs well under different network conditions.     

Access control management for ubiquitous computing

The purpose of ubiquitous computing is anywhere and anytime access to information within computing infrastructures that is blended into a background and no longer be reminded. This ubiquitous computing poses new security challenges while the information can be accessed at anywhere and anytime because it may be applied by criminal users. Additionally, the information may contain private information that cannot be shared by all user communities. Several approaches are developed to protect information for pervasive environments against malicious users. However, ad hoc mechanisms or protocols are typically added in the approaches by compromising disorganized policies or additional components to protect from unauthorized access.In this paper, we present a usage control model to protect services and devices in ubiquitous computing environments, which allows the access restrictions directly on services and object documents. The model not only supports complex constraints for pervasive computing, such as services, devices and data types but also provides a mechanism to build rich reuse relationships between models and objects. Finally, comparisons with related works are analysed.