The role of models@run.time in supporting on-the-fly interoperability

Models at runtime can be defined as abstract representations of a system, including its structure and behaviour, which exist in tandem with the given system during the actual execution time of that system. Furthermore, these models should be causally connected to the system being modelled, offering a reflective capability. Significant advances have been made in recent years in applying this concept, most notably in adaptive systems. In this paper we argue that a similar approach can also be used to support the dynamic generation of software artefacts at execution time. An important area where this is relevant is the generation of software mediators to tackle the crucial problem of interoperability in distributed systems. We refer to this approach as emergent middleware, representing a fundamentally new approach to resolving interoperability problems in the complex distributed systems of today. In this context, the runtime models are used to capture meta-information about the underlying networked systems that need to interoperate, including their interfaces and additional knowledge about their associated behaviour. This is supplemented by ontological information to enable semantic reasoning. This paper focuses on this novel use of models at runtime, examining in detail the nature of such runtime models coupled with consideration of the supportive algorithms and tools that extract this knowledge and use it to synthesise the appropriate emergent middleware.

Genie:supporting the model driven development of reflective, component-based adaptive systems

Engineering adaptive software is an increasingly complex task. Here, we demonstrate Genie, a tool that supports the modelling, generation, and operation of highly reconfigurable, component-based systems. We showcase how Genie is used in two case-studies: i) the development and operation of an adaptive flood warning system, and ii) a service discovery application. In this context, adaptation is enabled by the Gridkit reflective middleware platform.

EPiCS:engineering proprioception in computing systems

Modern compute systems continue to evolve towards increasingly complex, heterogeneous and distributed architectures. At the same time, functionality and performance are no longer the only aspects when developing applications for such systems, and additional concerns such as flexibility, power efficiency, resource usage, reliability and cost are becoming increasingly important. This does not only raise the question of how to efficiently develop applications for such systems, but also how to cope with dynamic changes in the application behaviour or the system environment. The EPiCS Project aims to address these aspects through exploring self-awareness and self-expression. Self-awareness allows systems and applications to gather and maintain information about their current state and environment, and reason about their behaviour. Self-expression enables systems to adapt their behaviour autonomously to changing conditions. Innovations in EPiCS are based on systematic integration of research in concepts and foundations, customisable hardware/software platforms and operating systems, and self-aware networking and middleware infrastructure. The developed technologies are validated in three application domains: computational finance, distributed smart cameras and interactive mobile media systems. © 2012 IEEE.

Making motes intelligent:an agent-based approach to wireless sensor networks

In-Motes is a mobile agent middleware that generates an intelligent framework for deploying applications in Wireless Sensor Networks (WSNs). In-Motes is based on the injection of mobile agents into the network that can migrate or clone following specific rules and performing application specific tasks. By doing so, each mote is given a certain degree of perception, cognition and control, forming the basis for its intelligence. Our middleware incorporates technologies such as Linda-like tuplespaces and federated system architecture in order to obtain a high degree of collaboration and coordination for the agent society. A set of behavioral rules inspired by a community of bacterial strains is also generated as the means for robustness of the WSN. In this paper, we present In-Motes and provide a detailed evaluation of its implementation for MICA2 motes.

In-Motes Bins:a real time application for environmental monitoring in wireless sensor networks

In-Motes Bins is an agent based real time In-Motes application developed for sensing light and temperature variations in an environment. In-Motes is a mobile agent middleware that facilitates the rapid deployment of adaptive applications in Wireless Sensor Networks (WSN's). In-Motes Bins is based on the injection of mobile agents into the WSN that can migrate or clone following specific rules and performing application specific tasks. Using In-Motes we were able to create and rapidly deploy our application on a WSN consisting of 10 MICA2 motes. Our application was tested in a wine store for a period of four months. In this paper we present the In-Motes Bins application and provide a detailed evaluation of its implementation. © 2007 IEEE.

INFRAWEBS Semantic Web Service Development on the Base of Knowledge Management Layer

The paper gives an overview about the ongoing FP6-IST INFRAWEBS project and describes the main layers and software components embedded in an application oriented realisation framework. An important part of INFRAWEBS is a Semantic Web Unit (SWU) – a collaboration platform and interoperable middleware for ontology-based handling and maintaining of SWS. The framework provides knowledge about a specific domain and relies on ontologies to structure and exchange this knowledge to semantic service development modules. INFRAWEBS Designer and Composer are sub-modules of SWU responsible for creating Semantic Web Services using Case-Based Reasoning approach. The Service Access Middleware (SAM) is responsible for building up the communication channels between users and various other modules. It serves as a generic middleware for deployment of Semantic Web Services. This software toolset provides a development framework for creating and maintaining the full-life-cycle of Semantic Web Services with specific application support.

Tempura Reengineering

Interval Temporal Logic provides time-dependant formal description of hardware and software. Such formalism is needed for description of behaviors of the middleware of AOmLE project, depending on different scenarios of operation. In order to use ITL, we need an interpreter. Tempura provides executable ITL framework, written in C language. We cannot use Tempura as is, because AOmLE is developed entirely in Java. For this reason we need Java version of Tempura. This paper describes our plan for reengineering of CTempura and creating Java version if the ITL interpreter.

Extending Object-Oriented Network Protocols via alternative Transportation Bindings (Web Services over XMPP)

Distributed and/or composite web applications are driven by intercommunication via web services, which employ application-level protocols, such as SOAP. However, these protocols usually rely on the classic HTTP for transportation. HTTP is quite efficient for what it does — delivering web page content, but has never been intended to carry complex web service oriented communication. Today there exist modern protocols that are much better fit for the job. Such a candidate is XMPP. It is an XML-based, asynchronous, open protocol that has built-in security and authentication mechanisms and utilizes a network of federated servers. Sophisticated asynchronous multi-party communication patterns can be established, effectively aiding web service developers. This paper’s purpose is to prove by facts, comparisons, and practical examples that XMPP is not only better suited than HTTP to serve as middleware for web service protocols, but can also contribute to the overall development state of web services.

Engineering access control for distributed enterprise applications

Access control (AC) is a necessary defense against a large variety of security attacks on the resources of distributed enterprise applications. However, to be effective, AC in some application domains has to be fine-grain, support the use of application-specific factors in authorization decisions, as well as consistently and reliably enforce organization-wide authorization policies across enterprise applications. Because the existing middleware technologies do not provide a complete solution, application developers resort to embedding AC functionality in application systems. This coupling of AC functionality with application logic causes significant problems including tremendously difficult, costly and error prone development, integration, and overall ownership of application software. The way AC for application systems is engineered needs to be changed. ^ In this dissertation, we propose an architectural approach for engineering AC mechanisms to address the above problems. First, we develop a framework for implementing the role-based access control (RBAC) model using AC mechanisms provided by CORBA Security. For those application domains where the granularity of CORBA controls and the expressiveness of RBAC model suffice, our framework addresses the stated problem. ^ In the second and main part of our approach, we propose an architecture for an authorization service, RAD, to address the problem of controlling access to distributed application resources, when the granularity and support for complex policies by middleware AC mechanisms are inadequate. Applying this architecture, we developed a CORBA-based application authorization service (CAAS). Using CAAS, we studied the main properties of the architecture and showed how they can be substantiated by employing CORBA and Java technologies. Our approach enables a wide-ranging solution for controlling the resources of distributed enterprise applications. ^

Interoperable resource brokering with policy-based provisioning and job allocation

The increasing needs for computational power in areas such as weather simulation, genomics or Internet applications have led to sharing of geographically distributed and heterogeneous resources from commercial data centers and scientific institutions. Research in the areas of utility, grid and cloud computing, together with improvements in network and hardware virtualization has resulted in methods to locate and use resources to rapidly provision virtual environments in a flexible manner, while lowering costs for consumers and providers. ^ However, there is still a lack of methodologies to enable efficient and seamless sharing of resources among institutions. In this work, we concentrate in the problem of executing parallel scientific applications across distributed resources belonging to separate organizations. Our approach can be divided in three main points. First, we define and implement an interoperable grid protocol to distribute job workloads among partners with different middleware and execution resources. Second, we research and implement different policies for virtual resource provisioning and job-to-resource allocation, taking advantage of their cooperation to improve execution cost and performance. Third, we explore the consequences of on-demand provisioning and allocation in the problem of site-selection for the execution of parallel workloads, and propose new strategies to reduce job slowdown and overall cost.^

Engineering access control for distributed enterprise applications

Access control (AC) is a necessary defense against a large variety of security attacks on the resources of distributed enterprise applications. However, to be effective, AC in some application domains has to be fine-grain, support the use of application-specific factors in authorization decisions, as well as consistently and reliably enforce organization-wide authorization policies across enterprise applications. Because the existing middleware technologies do not provide a complete solution, application developers resort to embedding AC functionality in application systems. This coupling of AC functionality with application logic causes significant problems including tremendously difficult, costly and error prone development, integration, and overall ownership of application software. The way AC for application systems is engineered needs to be changed. In this dissertation, we propose an architectural approach for engineering AC mechanisms to address the above problems. First, we develop a framework for implementing the role-based access control (RBAC) model using AC mechanisms provided by CORBA Security. For those application domains where the granularity of CORBA controls and the expressiveness of RBAC model suffice, our framework addresses the stated problem. In the second and main part of our approach, we propose an architecture for an authorization service, RAD, to address the problem of controlling access to distributed application resources, when the granularity and support for complex policies by middleware AC mechanisms are inadequate. Applying this architecture, we developed a CORBA-based application authorization service (CAAS). Using CAAS, we studied the main properties of the architecture and showed how they can be substantiated by employing CORBA and Java technologies. Our approach enables a wide-ranging solution for controlling the resources of distributed enterprise applications.

ArchWiSeN: uma estratégia baseada em modelos para desenvolvimento de aplicações para redes de sensores e atuadores sem fio

Wireless Sensor and Actuator Networks (WSAN) are a key component in Ubiquitous Computing Systems and have many applications in different knowledge domains. Programming for such networks is very hard and requires developers to know the available sensor platforms specificities, increasing the learning curve for developing WSAN applications. In this work, an MDA (Model-Driven Architecture) approach for WSAN applications development called ArchWiSeN is proposed. The goal of such approach is to facilitate the development task by providing: (i) A WSAN domain-specific language, (ii) a methodology for WSAN application development; and (iii) an MDA infrastructure composed of several software artifacts (PIM, PSMs and transformations). ArchWiSeN allows the direct contribution of domain experts in the WSAN application development without the need of specialized knowledge on WSAN platforms and, at the same time, allows network experts to manage the application requirements without the need for specific knowledge of the application domain. Furthermore, this approach also aims to enable developers to express and validate functional and non-functional requirements of the application, incorporate services offered by WSAN middleware platforms and promote reuse of the developed software artifacts. In this sense, this Thesis proposes an approach that includes all WSAN development stages for current and emerging scenarios through the proposed MDA infrastructure. An evaluation of the proposal was performed by: (i) a proof of concept encompassing three different scenarios performed with the usage of the MDA infrastructure to describe the WSAN development process using the application engineering process, (ii) a controlled experiment to assess the use of the proposed approach compared to traditional method of WSAN application development, (iii) the analysis of ArchWiSeN support of middleware services to ensure that WSAN applications using such services can achieve their requirements ; and (iv) systematic analysis of ArchWiSeN in terms of desired characteristics for MDA tool when compared with other existing MDA tools for WSAN.

Computazione Embodied e Disembodied: Cloud-based IoT

La tesi esplora la co-esistenza di computazioni embodied e disembodied nei moderni sistemi software, adottando come caso di studio il recente trend che vede sempre più coesi e integrati sistemi per l'Internet of Things e sistemi Cloud-based. Si analizzano i principali modelli di comunicazione, protocolli di comunicazione e architetture situate. Inoltre si realizza una piattaforma IoT Middleware cloud-based per mostrare come la computazione possa essere distribuita lato embodied e disembodied.

FEARLUS-G: A Semantic Grid Service for Land-Use Modelling,

Postprint

Investigation into a best practice model for providing an integrated user experience with mobile cloud applications

Mobile Cloud Computing promises to overcome the physical limitations of mobile devices by executing demanding mobile applications on cloud infrastructure. In practice, implementing this paradigm is difficult; network disconnection often occurs, bandwidth may be limited, and a large power draw is required from the battery, resulting in a poor user experience. This thesis presents a mobile cloud middleware solution, Context Aware Mobile Cloud Services (CAMCS), which provides cloudbased services to mobile devices, in a disconnected fashion. An integrated user experience is delivered by designing for anticipated network disconnection, and low data transfer requirements. CAMCS achieves this by means of the Cloud Personal Assistant (CPA); each user of CAMCS is assigned their own CPA, which can complete user-assigned tasks, received as descriptions from the mobile device, by using existing cloud services. Service execution is personalised to the user's situation with contextual data, and task execution results are stored with the CPA until the user can connect with his/her mobile device to obtain the results. Requirements for an integrated user experience are outlined, along with the design and implementation of CAMCS. The operation of CAMCS and CPAs with cloud-based services is presented, specifically in terms of service description, discovery, and task execution. The use of contextual awareness to personalise service discovery and service consumption to the user's situation is also presented. Resource management by CAMCS is also studied, and compared with existing solutions. Additional application models that can be provided by CAMCS are also presented. Evaluation is performed with CAMCS deployed on the Amazon EC2 cloud. The resource usage of the CAMCS Client, running on Android-based mobile devices, is also evaluated. A user study with volunteers using CAMCS on their own mobile devices is also presented. Results show that CAMCS meets the requirements outlined for an integrated user experience.