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.     

Effective distributed service architecture for ubiquitous video surveillance

Video surveillance systems are playing an important role to protect lives and assets of individuals, enterprises and governments. Due to the prevalence of wired and wireless access to Internet, it would be a trend to integrate present isolated video surveillance systems by applying distributed computing environment and to further gestate diversified multimedia intelligent surveillance (MIS) applications in ubiquity. In this paper, we propose a distributed and secure architecture for ubiquitous video surveillance (UVS) services over Internet and error-prone wireless networks with scalability, ubiquity and privacy. As cloud computing, users consume UVS related resources as a service and do not need to own the physical infrastructure, platform, or software. To protect the service privacy, preserve the service scalability and provide reliable UVS video streaming for end users, we apply the AES security mechanism, multicast overlay network and forward error correction (FEC), respectively. Different value-added services can be created and added to this architecture without introducing much traffic load and degrading service quality. Besides, we construct an experimental test-bed for UVS system with three kinds of services to detect fire and fall-incident features and record the captured video at the same time. Experimental results showed that the proposed distributed service architecture is effective and numbers of services on different multicast islands were successfully connected without influencing the playback quality. The average sending rate and the receiving rates of these services are quite similar, and the surveillance video is smoothly played.     

Design of a service oriented architecture for efficient resource allocation in media environments

In many business domains, Grids and Service Oriented Architectures are considered to improve application design, integration and execution. In the audiovisual industry, applications are very data-intensive, time-constrained and computationally demanding, and design of a Service Oriented Architecture in this domain is no straightforward task. Efficient resource allocation-especially in terms of network usage-is paramount to meet users’ requirements in terms of deadlines and responsiveness, and offer high scalability at the same time. We present a resource- and network-aware management architecture addressing the issues in media environments, incorporating a number of scheduling algorithms and advance reservation systems to ensure efficient resource usage.     

A hierarchical, agent-based service oriented architecture for smart environments

Service Oriented Architectures, which allow for the integration of different subsystems and of applications running on different devices and platforms, may be very suitable to solve the problem of service personalization in large smart environments like cities, where the number of potential users and potentially available services is rapidly growing. Taking this into account, we have designed an agent-based service oriented architecture for smart spaces. Two of the greatest challenges in the design of such a solution are providing effective device, service and context federation and composition mechanisms and handling user mobility. For the first challenge, we have designed a hierarchical architecture and developed a set of inheritance, aggregation and access mechanisms for devices, services and context. To handle user mobility, we have followed three different strategies, using stationary, mobile or nomadic agents. In this paper, we describe the main aspects of our architecture and perform an experimental evaluation to determine the advantages and drawbacks of the different strategies.     

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.     

Developing a survey for assessing preferences in constructivist context‐aware ubiquitous learning environments

This study developed a survey to explore students' preferences in constructivist context‐aware ubiquitous learning environments. A constructivist context‐aware ubiquitous learning (u‐learning) environment survey (CULES) was developed, consisting of eight scales, including ease of use, continuity, relevance, adaptive content, multiple sources, timely guidance, student negotiation, and inquiry learning. The survey responses were gathered from 215 university students from five universities in Taiwan. The students all had actual experience of using u‐learning systems in u‐learning environments. Both exploratory and confirmatory factor analyses showed that the CULES had high reliability and validity. The structural model revealed that the provision of realistic and close‐to‐real‐life information could enhance students' preferences for timely guidance, student negotiation, and inquiry‐learning activities. In addition, the attainment of inquiry learning is quite challenging when designing u‐learning activities, as it involves the enhancement of the other CULES scales.     

Open media service architecture for advanced collaboration environments

Advanced collaboration environments are extensively utilized for distance learning, e-science, and other distributed global collaboration events. In such environments, high-quality and seamless media services play an important role in improving the quality of user experience to participants. In this paper, to support high-quality media-based services, we design open media service architecture for advanced collaboration environments, by combining the open interface for state-of-the-art media tools, the performance monitoring tools for devices and networks, and application-level adaptation schemes for media streaming. By implementing the proposed architecture on top of an open-source Access Grid (AG) collaboration toolkit, we verify that high-quality collaboration among several collaboration sites can be effectively realized over a multicast-enabled network testbed with improved media quality experience.

A resource aware software partitioning algorithm based on mobility constraints in pervasive grid environments

Pervasive computing suffers from resource limitations of mobile devices, while grid computing can utilize almost unlimited resources distributed in the whole Internet. The conjunction of such two paradigms generates a new promising one, called pervasive grid computing, where mobile users can use handheld devices to access abundant resources and services in the grid. In this paper, a novel software partitioning algorithm is presented, which is suitable for pervasive grid to optimally allocate software components between a mobile device and one or more servers, with the goal of saving the resources of mobile devices. The algorithm takes into account component mobility constraints to not only prevent violating execution requirements of the application, but also to fully exploit component mobility, replication and rebinding to conserve more resources as compared to previous works. Another distinguishing feature of the algorithm is its generality, which can be applied to minimize network bandwidth usage, response time and energy consumption, respectively or simultaneously. Extensive simulation results have demonstrated the validity and effectiveness of the proposed algorithm in various environments.     

Improving service matching and selection in ubiquitous computing environments: a user study

In large ubiquitous computing environments it is hard for users to identify and activate the electronic services that match their needs. This user study compares the newly developed service matcher system with a conventional system for identifying and selecting appropriate services. The study addresses human factors issues such as usability, trust and service awareness. With the conventional system users have to browse a hierarchical list of currently available services and activate the service that they think satisfies their current needs. With the service matcher users just enter their current need using natural language, after which a wizard, emulating an existing service matcher algorithm, searches for and activates a matching service based on the given need and the users’ location and gaze direction. This study shows that with the hierarchical list, only 66% of the tasks are solved correctly, and females score significantly worse than males. With the service matcher, the performance increases significantly to 84% correctly performed tasks and the gender difference disappears.     

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     

A semantic service discovery approach for ubiquitous computing

Services in the ubiquitous computing are heterogeneous in nature. To be pervasive, these services should be defined in terms of their functionality and capabilities rather than the meaningless Universally Unique IDentifiers (UUIDs) or types of services. With that, clients can access the proper service based on semantic requests, rather then a pre-configured profile. In this paper, we study the requirements for semantic query to be feasible in service discovery processes. Current discovery protocols and the concept of semantics are brought together to construct a framework to realize the semantic service discovery for ubiquitous computing. Many issues are discussed in relation to service discovery topologies, ontology languages, and semantic query languages.     

A multimedia service composition scheme for ubiquitous networks

It is a challenging task to develop a high quality and secure multimedia service for mobile terminals used in the ubiquitous computing environment. One of the issues is the resource limitation of mobile terminals. In this paper, we presented a multimedia service composition scheme for sharing computer and communication resources by using plural terminals to compensate for this resource limitation. The proposed scheme is based on user authentication, service access control, and the multi-agent-based adaptive Quality-of-Service (QoS) control framework that we developed. We also proposed a novel access mode control based on the trustworthiness of users and extension of the multi-agent-based adaptive QoS control framework to plural users. Focusing on the home network as a typical ubiquitous network, we implemented a prototype testbed system and showed experimental results for the multimedia service composition.     

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。     

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.     

Complex service design: A virtual enterprise architecture for logistics service

This paper presents an interdisciplinary systems approach to service modeling, design and deployment. The study is based on a longitudinal case study of the development process of a complex logistic service system based on an advanced logistics model. The case examines the development of a Virtual Enterprise Architecture (VEA) for an automatic high-speed transport and sorting system applied in airports for baggage handling. The study traces the evolution of the system from the early conceptual phases to a successful commercial service deployed at Changi, Singapore Airport. The study is conducted using a retrospective analysis of the case using a design science research approach. The paper evaluates and discusses the issues of creating and designing a new complex logistics service, distinct from the physical product, based on an advanced discrete event-based simulation model. The paper concludes by presenting a generalized and validated conceptual framework for a VEA based on an advanced simulation model. The paper thus contributes to the field of service systems and service management by identifying a novel approach to effective design of a new service.     

Dreamer: A resource management architecture for Jini federation

In the paper, we developed a resource management architecture for Jini federation. Jini introduces in a leasing concept that handles partial failure of distributed applications, and also supports service resource allocation. However, current leasing model does not lay a stress on fairness and priority issues on the resource allocation. On the other hand, current lookup service lacks the capability to handle sophisticated service assignment, such as load balance issue, non-functional requirement matching, urgent service request and so on. In this paper, we aim to solve the deficiency described above by providing an architecture, which uses the information contained in resource leases to achieve better resource management.     

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。     

Real-time control architecture using Xenomai for intelligent service robots in USN environments

This paper describes the implementation of a dual-kernel software architecture, based on standard Linux and real-time embedded Linux, for real-time control of service robots in ubiquitous sensor network environments. Mobile robots are used in active service for the assisted living of elderly people, monitoring their mental and physiological data with wireless sensor nodes. The data collected from sensor nodes are routed back to a sink node through multi-hop communication. The moving sink node installed on the main controller of the robot collects data and transmits it to the main controller. To be able to handle emergency situations, the robot needs to satisfy real-time requirements when processing the data collected, and invoking tasks to execute. This paper realizes a multi-hop sensor network and proposes real-time software architecture based on Xenomai. The real-time tasks were implemented, with priority, to rapidly respond to urgent sensor data. In order to validate the deterministic response of the proposed system, the performance measurements for the delay in handling the sensed data transmission and the trajectory control with a feedback loop were evaluated on the non real-time standard Linux.     

Open corpus architecture for personalised ubiquitous e-learning

As the e-learning area matures, there are a growing number of e-learning content providers that produce and distribute material that covers a large range of topics, differs in quality and is represented in various formats. Lately, different devices and various network technologies allow extensive user access to educational content almost anywhere, anytime and from any device. Ubiquitous e-learning has the potential to provide continuous and context-based, educational material to human learners anytime, anywhere and on any device. Since each person has different expectations related to the content, the performance of the delivery and display of that content, it is desirable for an ubiquitous e-learning environment to provide user-oriented personalisation of e-learning material. However very often there are multiple sources of e-learning material at various web locations (open corpus resources) that cover the same topic, but differ in terms of quality, formatting and even cost. It is very difficult for learners to select the content that best suits their interests and goals, characteristics of the device used and delivery network as well as their cost budget. This paper proposes an innovative ubiquitous e-learning environment called Performance-based E-learning Adaptive Cost-efficient Open Corpus frameworK (PEACOCK) that provides support for the selection and distribution of personalised e-learning rich media content (e.g. multimedia, pictures, graphics and text) to e-learners such as it will best suit users’ interests and goals, meet their formatting preferences and cost constraints, while considering the limitations introduced by the end-user devices and the delivery networks to the user. PEACOCK’s main goal is to maximise the users’ e-learning experience and increase their learning satisfaction and learning outcome.