Activity-based computing: support for mobility and collaboration in ubiquitous computing

This paper presents the design philosophy of activity-based computing (ABC), which addresses mobility and cooperation in human work activities. Furthermore, it presents the ABC framework, which is a ubiquitous computing infrastructure supporting ABC. The idea of ABC and the aim of the ABC framework is to: (1) support human activity by managing its collection of work tasks on a computer, (2) support mobility by distributing activities across heterogeneous computing environments, (3) support asynchronous collaboration by allowing several people to participate in an activity, and (4) support synchronous, real-time collaboration by enabling desktop conferencing by sharing the activity across several clients. During a period of two years, the ABC framework has been co-designed and evaluated in close cooperation with a range of clinicians in a hospital.

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.     

An authentication protocol offering service anonymity of mobile device in ubiquitous environment

With the advent of ubiquitous era, various devices and services using wireless network are increasing. For communications in wireless network, mobile devices are used and various services are increasingly provided through mobile devices. The AAA (Authentication, Authorization, and Accounting) that authorizes and manages the mobile devices is processing the standardization for various application services for the purpose of the standardization of authentication, authorization, and accounting to provide safety and reliability of various services and protocols of both wired and wireless network. However, even if AAA exists the development of network varies vulnerabilities and attack types, and accordingly the exposure of information appears as the biggest problem. Therefore, this study suggests the safe authentication method that protects against information exposure by guaranteeing anonymity of service with temporal ID, and provides efficiency because AAA authentication server is based on the ticket given to a service server without the need of re-authentication when mobile node authorized from the AAA authentication server receives service.     

An identity authentication scheme based on cloud computing environment

In order to solve the shortcomings of traditional identity authentication technology, such as low security, low efficiency, a mobile terminal identity authentication scheme based on cloud computing environment is proposed in this paper. In addition, the two-dimensional code technology is used for identity authentication in the cloud computing environment, and the QR coding technology is also used. The dynamic authentication of the mobile terminal is realized by using the two-dimensional code as the information transmission carrier. According to the security analysis, the scheme has simple structure and no need to use the third party equipment, which has high security and adaptability. Finally, the two fusion of two-dimensional code proposed in this paper provides a new way of thinking for the identity authentication based on the cloud environment, and also promotes the development of the Internet of things.     

Adaptive video-on-demand broadcasting in ubiquitous computing environment

Video-on-demand (VOD) is a service that allows users to view any video program from a server at the time of their choice, such kind of services are expected to be popular in future ubiquitous computing environment. Lots of broadcasting protocols for VOD services have been proposed, but they usually focus only on the tradeoff between bandwidth and delay, thus they are usually not efficient for the local storage. Since the ubiquitous network is heterogeneous and users will have different resource and communication capability, we need to address the storage issue in VOD systems. In this paper, we present several new effective broadcasting schemes, which can intelligently adjust the solution according to available bandwidth and local storage to achieve an ideal waiting time.     

普适环境下农业智能生产系统设计构思

本文分析了不同时代下的农业生产模式,构思设计了普适计算环境下的农业生产系统的系统模型和框架结构图.展望了普适农业环境下可能的农业生产场景,分析了普适环境下农业系统实现的必要条件和面临的挑战.本文内容是普适思想与农业领域的一次结合,对未来普适环境下自动化农业生产系统的发展有一定的参考意义.     

普适计算环境下的设备请求代理模型*

为了给普适计算环境提供一个统一的应用架构和模式,本文从普适计算研究现状出发,通过借鉴对象请求代理技术,提出了设备请求代理模型,建立了设备基件的远程映射管理和统一调度机制,有效降低了普适计算环境下应用程序的开发难度和兼容传统应用程序。     

An efficient list-based task scheduling algorithm for heterogeneous distributed computing environment

The task scheduling in heterogeneous distributed computing systems plays a crucial role in reducing the makespan and maximizing resource utilization. The diverse nature of the devices in heterogeneous distributed computing systems intensifies the complexity of scheduling the tasks. To overcome this problem, a new list-based static task scheduling algorithm namely Deadline-Aware-Longest-Path-of-all-Predecessors (DA-LPP) is being proposed in this article. In the prioritization phase of the DA-LPP algorithm, the path length of the current task from all its predecessors at each level is computed and among them, the longest path length value is assigned as the rank of the task. This strategy emphasizes the tasks in the critical path. This well-optimized prioritization phase leads to an observable minimization in the makespan of the applications. In the processor selection phase, the DA-LPP algorithm implements the improved insertion-based policy which effectively utilizes the unoccupied leftover free time slots of the processors which improve resource utilization, further least computation cost allocation approach is followed to minimize the overall computation cost of the processors and parental prioritization policy is incorporated to further reduce the scheduling length. To demonstrate the robustness of the proposed algorithm, a synthetic graph generator is used in this experiment to generate a huge variety of graphs. Apart from the synthetic graphs, real-world application graphs like Montage, LIGO, Cybershake, and Epigenomic are also considered to grade the performance of the DA-LPP algorithm. Experimental results of the DA-LPP algorithm show improvement in performance in terms of scheduling length ratio, makespan reduction rate , and resource reduction rate when compared with other algorithms like DQWS, DUCO, DCO and EPRD. The results reveal that for 1000 task set with deadline equals to two times of the critical path, the scheduling length ratio of the DA-LPP algorithm is better than DQWS by 35%, DUCO by 23%, DCO by 26 %, and EPRD by 17%.     

Relationship Management: Secure collaboration in a ubiquitous environment

Intel recently engaged in an experiment that focused on local identity management. Researchers developed a relationship management module that runs on various devices. Using RM, groups of people can securely share documents, text messages, and other electronic media.     

普适计算环境下基于移动Agent的分布式交互方法

为提高普适计算环境下人机交互的透明性和持久性,提出一种基于移动Agent的分布式交互方法,用户通过由移动Agent实现的交互Agent在网络中进行交流。交互Agent代表用户作为交互的对等实体,根据需要在网络中迁移并保持交互状态,通过可定制的各种行为和协同运作方式实现不同的交互应用。该方法能够实现交互实体之间透明的、智能的、可移动的交互过程,提供及时的交互服务和灵活的信息共享方式。     

Mobile cloud computing framework for a pervasive and ubiquitous environment

The increasing use of wireless Internet and smartphone has accelerated the need for pervasive and ubiquitous computing (PUC). Smartphones stimulate growth of location-based service and mobile cloud computing. However, smartphone mobile computing poses challenges because of the limited battery capacity, constraints of wireless networks and the limitations of device. A fundamental challenge arises as a result of power-inefficiency of location awareness. The location awareness is one of smartphone’s killer applications; it runs steadily and consumes a large amount of power. Another fundamental challenge stems from the fact that smartphone mobile devices are generally less powerful than other devices. Therefore, it is necessary to offload the computation-intensive part by careful partitioning of application functions across a cloud. In this paper, we propose an energy-efficient location-based service (LBS) and mobile cloud convergence. This framework reduces the power dissipation of LBSs by substituting power-intensive sensors with the use of less-power-intensive sensors, when the smartphone is in a static state, for example, when lying idle on a table in an office. The substitution is controlled by a finite state machine with a user-movement detection strategy. We also propose a seamless connection handover mechanism between different access networks. For convenient on-site establishment, our approach is based on the end-to-end architecture between server and a smartphone that is independent of the internal architecture of current 3G cellular networks.     

云计算身份认证模型研究

云计算是在继承和融合众多技术基础上的一个突破性创新,已成为当前应用和研究的重点与热点。其中,云用户与云服务之间以及云平台中不同系统之间的身份认证与资源授权是确保云计算安全性的前提。在简要介绍云计算信息基础架构的基础上,针对云计算统一身份认证的特点和要求,综合分析了SAML2.0、OAuth2.0和Open ID2.0等技术规范的功能特点,提出了一种开放标准的云计算身份认证模型,为云计算中逻辑安全域的形成与管理提供了参考。     

The BEACH application model and software framework for synchronous collaboration in ubiquitous computing environments

In this paper, a conceptual model for synchronous applications in ubiquitous computing environments is proposed. To test its applicability, it was used to structure the architecture of the BEACH software framework that is the basis for the software infrastructure of i-LAND (the ubiquitous computing environment at FhG-IPSI). The BEACH framework provides the functionality for synchronous cooperation and interaction with roomware components, i.e. room elements with integrated information technology. To show how the BEACH model and framework can be applied, the design of a sample application is explained. Also, the BEACH model is positioned against related work. In conclusion, we provide our experiences with the current implementation.     

P2P协同工作环境下的一种多媒体认证系统

为了适应P2P协同工作中的安全需求，针对多媒体数据的特殊性，探讨了传统的多媒体认证方法，提出了一种结合数字签名和数字水印的多媒体信息认证方案，系统利用JXTA平台的安全特性，采用双重身份及易损水印的认证机制，使得非法篡改、伪造多媒体信息更加困难。分析表明，该方案具有安全性高、可信度高等特点，适用于图像、数据等多媒体的安全传输。     

一种基于信任度的跨异构域动态认证机制

为了适应大规模网络环境下异构域认证机制不一致、域间信任关系动态变化的特点,提出了一种基于信任度的跨异构域的动态认证方法,该方法根据交易双方的满意度打分来计算信任值,动态地建立域间信任关系。应用实例表明,该方法能够有效解决跨域认证中域间信任关系的建立问题。     

Primitives for distributed computing in a heterogeneous local areanetwork environment

Epsilon is a testbed for monitoring distributed applications involving heterogeneous computers, including microcomputers, interconnected by a local area network. Such a hardware configuration is usual but raises difficulties for the programmer. First, the interprocess communication mechanisms provided by the operating systems are rather cumbersome to use. Second, they are different from one system to another. Third, the programmer of distributed applications should not worry about system and/or network aspects that are not relevant for the application level. The authors present the solution chosen in Epsilon. A set of high-level communication primitives has been designed and implemented to provide the programmer with an interface independent of the operating system and of the underlying interprocess communications facilities. A program participating in a distributed application can be executed on any host without any change in the source code except for host names     

System software for ubiquitous computing

The authors identify two key characteristics of ubiquitous computing systems: physical integration and spontaneous interoperation. They examine how these properties affect the design of ubiquitous computing software and discuss future directions.     

Ubiquitous security for ubiquitous computing

The potential for rapid and diverse interconnectivity through devices utilising heterogeneous communications interfaces has enabled a truly ubiquitous computing environment. However, this has resulted in equally ubiquitous security risks due principally to the number and complexity of services being run over such networks. As technology advances towards the realisation of a ubiquitous computing environment, what impact does this have on the traditional information security triangle, of preserving the confidentiality, integrity and availability of information? And how does this influence, future information security requirements, particularly in light of always-on business processes which require real-time information sharing? This paper describes research conducted into answering these questions. Emphasis is placed on the need for risk management, and how this may be achieved through context-based access control mechanisms and pro-active threat assessment techniques.     

Acoustic modems for ubiquitous computing

Considers how sound offers features not available with other short-range, low bandwidth communication technologies, such as radio and infrared, enabling communication among small computing devices and humans in a ubiquitous computing environment.