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.     

元数据驱动的可定制短信自主服务中间件

为了解除短信服务与具体业务系统的强耦合关系,解决短信服务的可维护性、可复用性问题,实现服务逻辑的可定制目标,提出一种元数据驱动的可定制短信服务中间件设计方案.对短信服务建模,抽象出具有柔性机制的通用服务模型.定义和使用元数据,实现短信服务的可定制.基于元数据的异构数据实时集成,使短信服务能够适配异构业务数据源,实现中间件的通用化.中间件的部署使用,证明可定制短信服务中间件具有良好通用性、可维护性、可靠性,能够适应短信服务需求的不断变化.     

Rule-driven service coordination middleware for scientific applications

With the proliferation of Web services, scientific applications are more and more designed as temporal compositions of services, commonly referred to as workflows. To address this paradigm shift, different workflow management systems have been proposed. While their efficiency has been established over centralized static systems, it is questionable over decentralized failure-prone platforms.Scientific applications recently started to be deployed over large distributed computing platforms, leading to new issues, like elasticity, i.e., the possibility to dynamically refine, at runtime, the amount of resources dedicated to an application. This raised again the demand for new programming models, able to express autonomic self-coordination of services in a dynamic platform.Nature-inspired, rule-based computing models recently gained a lot of attention in this context. They are able to naturally express parallelism, distribution, and autonomic adaptation. While their high expressiveness and adequacy for this context has been established, such models severely suffer from a lack of proof of concepts. In this paper, we concretely show how to leverage such models in this context. We focus on the design, the implementation and the experimental validation of a chemistry-inspired scientific workflow management system.     

统一存储网中的虚拟存储技术研究

随着网络存储技术的发展,存储局域网和附网存储的融合是大势所趋。该文详细介绍了构建一个统一的存储网络的关键技术——存储虚拟化,并提出统一存储网的实验方案,针对其中与存储虚拟化有关的具体问题进行了探讨和研究。     

Secure data processing for IoT middleware systems

The Journal of Supercomputing - Increasingly, more manufacturing companies are equipping their products with smart capabilities which allow them to provide more informed services to customers....     

RFID中间件数据处理与过滤方法的研究

作为无线射频识别（RFID）系统测试平台的数据采集单元,RFID数据采集中间主要负责测试数据的采集和初步的数据处理与过滤。首先介绍了它的系统架构,然后重点介绍了它的数据处理与过滤模块,对逻辑映射引擎进行了分析,并且详细介绍了三种类型的RFID数据过滤器：去重过滤器、事件过滤器和标签码过滤器。     

面向移动云存储的属性基解密服务中间件

属性基加密（ABE）算法支持对云端数据的细粒度访问控制。针对属性基解密计算复杂度高,难以在资源受限的移动终端上实现的问题,提出并实现了一种面向移动云存储的属性基解密服务中间件。在保证密文信息不被中间件获取的前提下,中间件为移动终端代理属性基解密服务,实现了基于树形结构的线性秘密共享（LSSS）矩阵求解,降低了终端的计算与通信开销,提高了解密速度;属性权威可以在不需要用户参与的条件下,即时、细粒度地撤销用户属性;所有接口均使用Restful服务,保证了通用性。实验结果表明,属性基解密服务中间件提高移动设备解密性能近30倍,具备较好的并发性能,属性撤销具有实用性。     

面向分布式信息服务平台的协调中间件系统

为了更好地满足用户对分布式信息服务平台的QoS要求，对一个异构的数据库簇进行了研究，提出了基于该簇的一个协调中间件的逻辑模型，并对其设计思想及实现方法进行了详细介绍。该模型将数据的新鲜度引入设计过程，用它作为事务处理的QoS参数来提高系统服务质量。     

Communication mechanisms in ecological network-based grid middleware for service emergence

Next generation grid systems are heading for globally collaborative, service-oriented and live information systems that exhibit a strong sense of automation. A collection of autonomous agents is searched, assembled, and coordinated in a grid middleware system to produce desirable grid services. An effective communication mechanism is vital to the effectiveness of the step to build a novel grid middleware system. In this study, we provide our grid middleware with a flexible communication solution to implement the complicated behaviors among different agents. We propose a transport mechanism of grid middleware, named as ecological network communication language (ENCL) and ecological network interaction protocol (ENIP) respectively from a low-level to a high-level implementation strategy of a communication mechanism. A series of experiments demonstrate that a service with some of the desired properties can emerge from interacting agents via the proposed solution.     

Context-aware handoff middleware for transparent service continuity in wireless networks

Advances in wireless networking and content delivery are enabling new challenging provisioning scenarios where a growing number of users access continuous services, e.g., audio/video streaming, while moving among different points of attachment to the Internet, possibly with different connectivity technologies, e.g., Wi-Fi, Bluetooth, and cellular 3G. That calls for novel middlewares capable of dynamically personalizing service provisioning to the characteristics of client environments, in particular to discontinuities in wireless resource availability due to handoffs. The paper proposes a novel middleware solution, called Mobile agent-based Ubiquitous multimedia Middleware (MUM), that performs effective and context-aware handoff management to transparently avoid service interruptions during both horizontal and vertical handoffs. MUM exploits the full visibility of wireless connections available and their handoff implementations (handoff awareness), of service quality requirements and handoff-related quality degradations (QoS awareness), and of network topology and local resource availability (location awareness); that visibility enables MUM to provide original solutions for handoff prediction, multimedia continuity via adaptive data buffering/pre-fetching, and proactive re-addressing/rebinding.     

图像处理中间件在嵌入式系统中的设计与实现*

针对目前嵌入式系统中图片浏览功能的不足,通过分析彩色LCD显示驱动原理、图像处理技术,提出了一种图像处理中间件,并讨论了实现过程中的关键技术.实践证明该中间件方案切实可行,可以广泛应用于图像处理的嵌入式应用系统中.     

Supporting collaborative engineering using an intelligent web service middleware

Collaborative Engineering tasks are difficult to manage and involve a high amount of risk - as such, these tasks generally involve only well-known pre-established relationships. Such collaborations are generally quite static and do not allow for dynamic reactions to changes in the environment. Furthermore, not all optimal resource providers can be utilised for the respective tasks as they are potentially unknown. The TrustCoM project elaborated the means to create and manage Virtual Organisations in a trusted and secure manner integrating different providers on-demand. However, TrustCoM focused more on the VO than on the participant, whereas the BREIN project is now enhancing the intelligence of such VO systems to support even providers with little business expertise and provide them with capabilities to optimise their performance. This paper analyses the capabilities of current VO frameworks on the example of TrustCoM and identifies the gaps from the participant’s perspective. It then shows how BREIN addresses these gaps.     

Towards a trust evaluation middleware for cloud service selection

With the advent of cloud computing, employing various cloud services to build highly reliable cloud applications has become increasingly popular. The trustworthiness of cloud services is a critical issue that hinders the development of cloud applications, and thus is an urgently-required research problem. Previous studies evaluate trustworthiness of services via either QoS monitoring mechanisms or user feedback ratings, while seldom they combine both of them for enhancing service trust evaluation. This paper proposes a trustworthy selection framework for cloud service selection, named TRUSS. Aiming at developing an effective trust evaluation middleware for TRUSS, we propose an integrated trust evaluation method via combining objective trust assessment and subjective trust assessment. The objective trust assessment is based on QoS monitoring, while the subjective trust assessment is based on user feedback ratings. Experiments conducted using a synthesized dataset show that our proposed method significantly outperforms the other trust and reputation methods.     

Towards an ideal service QoS in fuzzy logic-based adaptation planning middleware

Mobile applications require an adaptation phase to adapt to the user's and application context. Utility functions or rules are most often used to make the adaptation planning or decision, i.e. select the most adapted variant for each required service. Fuzzy controllers are used when it is difficult or even impossible to construct precise mathematical models. In the case of mobile applications, the large number of Quality of Service (QoS) and context parameters causes an exponential increase in the number of rules (aka. rule explosion problem), that increases the processing time of the adaptation planning. To reduce the processing time and simplify the fuzzy control system, we propose the concept of ideal QoS. Fuzzy values of ideal QoS parameters are calculated using several fuzzy control systems to fit the context state and user preferences. A fuzzy logic similarity metric based on fuzzy sets and fuzzy operators is proposed to select the service variant having the nearest QoS values to the ideal. Experiments show that our approach can significantly improve both the number of rules and the processing time when selecting the variant that well adapts to environment changes.     

Queueing analysis of a server node in transaction processing middleware systems

Quantitative performance modeling of complex information systems is of immense importance for designing enterprise e-business infrastructures and applications. In this paper, we present a traffic model of a server node in a typical transaction processing middleware system as well as a quantitative framework to model and analyze its performance. A multi-class open queueing network model is presented in which multi-class jobs are admitted to a number of server processes sharing hardware resources including the CPU and the disk. We have developed a viable approximation method, which decomposes the dependent components into their independent counterparts while preserving their relevant characteristics. We have conducted queueing-theoretic delay analyses and verified the approach using simulation. Results demonstrate the strength of our approach in predicting delays, elapsed times and other system performance measures.     

An adaptive quality of service aware middleware for replicated services

A dependable middleware should be able to adaptively share the distributed resources it manages in order to meet diverse application requirements, even when the quality of service (QoS) is degraded due to uncertain variations in load and unanticipated failures. We have addressed this issue in the context of a dependable middleware that adaptively manages replicated servers to deliver a timely and consistent response to time-sensitive client applications. These applications have specific temporal and consistency requirements, and can tolerate a certain degree of relaxed consistency in exchange for better response time. We propose a flexible QoS model that allows clients to specify their timeliness and consistency constraints. We also propose an adaptive framework that dynamically selects replicas to service a client's request based on the prediction made by probabilistic models. These models use the feedback from online performance monitoring of the replicas to provide probabilistic guarantees for meeting a client's QoS specification. The experimental results we have obtained demonstrate the role of feedback and the efficacy of simple analytical models for adaptively sharing the available replicas among the users under different workload scenarios.     

CROWN:A service grid middleware with trust management mechanism

Based on a proposed Web service-based grid architecture, a service grid middleware system called CROWN is designed in this paper. As the two kernel points of the middleware, the overlay-based distributed grid resource management mechanism is proposed, and the policy-based distributed access control mechanism with the capability of automatic negotiation of the access control policy and trust management and negotia- tion is also discussed in this paper. Experience of CROWN testbed deployment and ap- plication development shows that the middleware can support the typical scenarios such as computing-intensive applications, data-intensive applications and mass information processing applications.     

QoS中间件中实时发布/订阅服务集成评估

支持QoS的中间件技术在构造分布式实时嵌入式系统中得到了广泛应用,已成为支持实时发布/订阅服务的关键技术.评估并分析了QoS中间件中3种集成实时发布/订阅服务方法.重点研究了容器管理方式的性能,并与面向对象的实时发布/订阅服务比较.研究结果表明,容器管理方式中,CIAO中间件的等待时间稍长,有可预测性,适用于DRE系统.     

Combining heterogeneous service technologies for building an Internet of Things middleware

Radio-frequency identification (RFID) is a technology that allows ordinary objects to be uniquely identified by “smart tags” which are also capable of storing small quantities of data. The term Internet of Things was originated from a vision strongly coupled with supply-chain concerns and RFID tagged objects. However the idea of such Internet of Things has evolved in a wider sense, referring now to a ubiquitous object society combining RFID, sensor networks and pervasive computing technologies. This scenario involves different requirements such as heterogeneity and dynamicity of objects, sensors, applications and protocols as well as the need for allowing the dynamic evolution of such applications. These issues seemed to be easily addressed if the principles of service-oriented computing (SOC), like loose coupling and heterogeneity, are used for constructing such architectures and applications. In this paper we underline what benefits SOC can offer to constructing a middleware for the Internet of Things. These concepts have been applied in a service-oriented middleware that tries to leverage the existing Internet of Things architectural concepts by using SOC principles in order to bring more flexibility and dynamicity. We describe the approaches used in that middleware and the lessons learned from that experience. This middleware was initially tested on an application for tracking and monitoring supply-chain objects, and later extended to target wider application domains that are also described in this paper. The project described here has become part of the OW2 AspireRFID open-source project.