A look at cloud architecture interoperability through standards

Enabling cloud infrastructures to evolve into a transparent platform while preserving integrity raises interoperability issues. How components are connected needs to be addressed. Interoperability requires standard data models and communication encoding technologies compatible with the existing Internet infrastructure. To reduce vendor lock-in situations, cloud computing must implement universal strategies regarding standards, interoperability and portability. Open standards are of critical importance and need to be embedded into interoperability solutions. Interoperability is determined at the data level as well as the service level. Corresponding modelling standards and integration solutions shall be analysed

Programming patterns and development guidelines for Semantic Sensor Grids (SemSorGrid4Env)

The web of Linked Data holds great potential for the creation of semantic applications that can combine self-describing structured data from many sources including sensor networks. Such applications build upon the success of an earlier generation of 'rapidly developed' applications that utilised RESTful APIs. This deliverable details experience, best practice, and design patterns for developing high-level web-based APIs in support of semantic web applications and mashups for sensor grids. Its main contributions are a proposal for combining Linked Data with RESTful application development summarised through a set of design principles; and the application of these design principles to Semantic Sensor Grids through the development of a High-Level API for Observations. These are supported by implementations of the High-Level API for Observations in software, and example semantic mashups that utilise the API

A framework for usage management

This thesis proposes a formal framework for usage management in distributed systems. The principles of system design are applied in order to standardize certain features of the framework, such as the operational semantics, and leave free of standards areas that necessitate choice and innovation. The framework enables use of multiple policy languages, and dynamic interpretation of usage policies in different computing environments. In addition, the framework provides formal semantics to reason about interoperability of policies with respect to computing environments. The use of this framework in different usage management scenarios is demonstrated including multi-level security, cloud computing and digital rights management (DRM) systems. Furthermore, DRM is cast in a setting that allows the modeling of a number of current approaches within a game theoretic setting. Current strategies that attempt to influence the outcome of such games are analyzed, and a new type of architectural infrastructure that makes novel use of a trust authority is considered in order to create a suitable environment for constructing DRM games that may prove useful in the future

Liquid stream processing on the web: a JavaScript framework

The Web is rapidly becoming a mature platform to host distributed applications. Pervasive computing application running on the Web are now common in the era of the Web of Things, which has made it increasingly simple to integrate sensors and microcontrollers in our everyday life. Such devices are of great in- terest to Makers with basic Web development skills. With them, Makers are able to build small smart stream processing applications with sensors and actuators without spending a fortune and without knowing much about the technologies they use. Thanks to ongoing Web technology trends enabling real-time peer-to- peer communication between Web-enabled devices, Web browsers and server- side JavaScript runtimes, developers are able to implement pervasive Web ap- plications using a single programming language. These can take advantage of direct and continuous communication channels going beyond what was possible in the early stages of the Web to push data in real-time. Despite these recent advances, building stream processing applications on the Web of Things remains a challenging task. On the one hand, Web-enabled devices of different nature still have to communicate with different protocols. On the other hand, dealing with a dynamic, heterogeneous, and volatile environment like the Web requires developers to face issues like disconnections, unpredictable workload fluctuations, and device overload. To help developers deal with such issues, in this dissertation we present the Web Liquid Streams (WLS) framework, a novel streaming framework for JavaScript. Developers implement streaming operators written in JavaScript and may interactively and dynamically define a streaming topology. The framework takes care of deploying the user-defined operators on the available devices and connecting them using the appropriate data channel, removing the burden of dealing with different deployment environments from the developers. Changes in the semantic of the application and in its execution environment may be ap- plied at runtime without stopping the stream flow. Like a liquid adapts its shape to the one of its container, the Web Liquid Streams framework makes streaming topologies flow across multiple heterogeneous devices, enabling dynamic operator migration without disrupting the data flow. By constantly monitoring the execution of the topology with a hierarchical controller infrastructure, WLS takes care of parallelising the operator execution across multiple devices in case of bottlenecks and of recovering the execution of the streaming topology in case one or more devices disconnect, by restarting lost operators on other available devices

Role-Based Enterprise Mashups with State Sharing, Preservation and Restoration Support for Multi-Instance Executions

Veebimaastikul suurt populaarsust kogunud tavatarbijatele suunatud vidinapõhised veebi-rakendused on loonud soodsa pinnase üldotstarbeliste mashup’ite loomise raamistike ning tööriistade tekkeks. Need tööriistad on eelkõige suunatud tava-Interneti kasutajatele, et luua lihtsaid mashup-tüüpi rakendusi. Samal ajal oleks vidinapõhistest veebirakendustest kasu ka ärirakendustena. Peamiseks takistuseks ärirakenduste loomisel veebipõhiste raken-dustena on keerulisest äriloogikast tulenevad keerukad nõuded ning protsessid. Antud magistritöö uurib, kuidas teostada veebividinatel põhinevate mashup-tüüpi ärirakenduste arendamist nii, et säiluks mashup’ite loomisega seotud peamised eelised, lihtsus ja kiirus. Käesolev magistritöö pakub välja laienduse olemasolevale mashup-tüüpi raamistikule, et toetada mashup’i dekompositsiooni rollipõhisteks vaadeteks. Selleks jagatakse mashup väiksemateks vidinate komplektideks, tagades igale kasutajarollile komplekt just temale vajaminevatest vidinatest. Kuigi igal kasutajarollil võib olla erinev vaade kogu ärirakendusest, tagab käesolevas magistritöös pakutud lahendus suhtluse nende erinevate vaadete vahel. See on vajalik tagamaks mashup’i eksemplari ühtsust kõikide mashup’i vaadete vahel, olenemata sellest, millistest vidinatest antud kasutaja vaade koosneb. Lisaks pakub käesolev magistritöö välja lahenduse toetamaks mitut eksemplari samast vidinapõhisest ärirakendusest ning toetamaks ärirakenduse oleku salvestamist ning taastamist. Kuna ärirakendused on suunatud lahendamaks kasutajate igapäevaseid ülesandeid, on vajalik, et kasutaja saaks valida olemasolevate mashup’i eksemplaride hulgast või alustada uut eksemplari. Lisaks on vajalik, et kasutaja saaks igal ajahetkel rakenduse kasutamise lõpetada selliselt, et hiljem rakenduse kasutamist jätkates oleks tagatud sama rakenduse olek, millest kasutamine katkestati. Väljapakutud lahenduse toimimist testitakse näidisrakendusega, mis realiseerib krediidihalduse protsessi.Recent hype on consumer web mashups has resulted in many general-purpose mashup frameworks and tools. These tools aim at simplifying the creation of mashups targeted to mainstream Internet users. At the same time, mashups are also used for solving specific business-related tasks. Such mashups are called enterprise mashups and more sophisticated frameworks and tools have been developed to support their creation. However, similarly to traditional web application development tools, the complexity of these frameworks is hindering the main benefits associated with mashup development – agility and simplicity. This thesis aims at extending a general-purpose mashup framework to support develop-ment of enterprise mashups while still preserving the simplicity and agility of develop-ment. More specifically, this thesis describes a solution for role-based decomposition of mashups for multi-instance executions with state sharing, preservation and restoration. In this thesis, a general-purpose mashup framework is extended with the concept of roles to support multi-user interaction and decomposing complex enterprise mashups with rich interactions into role-based views. In the context of this thesis, a view is defined as a subset of widgets a mashup is made of. Hence, through views an effective mechanism is provided for decomposing enterprise mashups to mashups as simple as general-purpose mashups. Additionally, this thesis proposes a generic solution for multi-instance mashup executions. In this thesis, each workflow instance is associated with an instance of a mashup. Since situational applications target at solving users day-to-day tasks, it is necessary to support multiple instances of a mashup. Furthermore, support for multiple mashup instances leverages users’ ability to participate in multiple workflow instances and to initialize new ones. Such mashup instances are in this thesis also referred to as mashup sessions. Finally, a solution is proposed for supporting mashup state sharing, preservation and restoration. Sharing states with other users is the key mechanism for facilitating interaction and collaboration between multiple users. State preservation and restoration are needed to allow a user to stop using the mashup and to resume to the same state at a later time. The proposed solution is also validated through a proof of concept application

Information visualisation and data analysis using web mash-up systems

A thesis submitted in partial fulfilment for the degree of Doctor of PhilosophyThe arrival of E-commerce systems have contributed greatly to the economy and have played a vital role in collecting a huge amount of transactional data. It is becoming difficult day by day to analyse business and consumer behaviour with the production of such a colossal volume of data. Enterprise 2.0 has the ability to store and create an enormous amount of transactional data; the purpose for which data was collected could quite easily be disassociated as the essential information goes unnoticed in large and complex data sets. The information overflow is a major contributor to the dilemma. In the current environment, where hardware systems have the ability to store such large volumes of data and the software systems have the capability of substantial data production, data exploration problems are on the rise. The problem is not with the production or storage of data but with the effectiveness of the systems and techniques where essential information could be retrieved from complex data sets in a comprehensive and logical approach as the data questions are asked. Using the existing information retrieval systems and visualisation tools, the more specific questions are asked, the more definitive and unambiguous are the visualised results that could be attained, but when it comes to complex and large data sets there are no elementary or simple questions. Therefore a profound information visualisation model and system is required to analyse complex data sets through data analysis and information visualisation, to make it possible for the decision makers to identify the expected and discover the unexpected. In order to address complex data problems, a comprehensive and robust visualisation model and system is introduced. The visualisation model consists of four major layers, (i) acquisition and data analysis, (ii) data representation, (iii) user and computer interaction and (iv) results repositories. There are major contributions in all four layers but particularly in data acquisition and data representation. Multiple attribute and dimensional data visualisation techniques are identified in Enterprise 2.0 and Web 2.0 environment. Transactional tagging and linked data are unearthed which is a novel contribution in information visualisation. The visualisation model and system is first realised as a tangible software system, which is then validated through different and large types of data sets in three experiments. The first experiment is based on the large Royal Mail postcode data set. The second experiment is based on a large transactional data set in an enterprise environment while the same data set is processed in a non-enterprise environment. The system interaction facilitated through new mashup techniques enables users to interact more fluently with data and the representation layer. The results are exported into various reusable formats and retrieved for further comparison and analysis purposes. The information visualisation model introduced in this research is a compact process for any size and type of data set which is a major contribution in information visualisation and data analysis. Advanced data representation techniques are employed using various web mashup technologies. New visualisation techniques have emerged from the research such as transactional tagging visualisation and linked data visualisation. The information visualisation model and system is extremely useful in addressing complex data problems with strategies that are easy to interact with and integrate

A Survey on the Web of Things

The Web of Things (WoT) paradigm was proposed first in the late 2000s, with the idea of leveraging Web standards to interconnect all types of embedded devices. More than ten years later, the fragmentation of the IoT landscape has dramatically increased as a consequence of the exponential growth of connected devices, making interoperability one of the key issues for most IoT deployments. Contextually, many studies have demonstrated the applicability of Web technologies on IoT scenarios, while the joint efforts from the academia and the industry have led to the proposals of standard specifications for developing WoT systems. Through a systematic review of the literature, we provide a detailed illustration of the WoT paradigm for both researchers and newcomers, by reconstructing the temporal evolution of key concepts and the historical trends, providing an in-depth taxonomy of software architectures and enabling technologies of WoT deployments and, finally, discussing the maturity of WoT vertical markets. Moreover, we identify some future research directions that may open the way to further innovation on WoT systems

Enhancement of the usability of SOA services for novice users

Recently, the automation of service integration has provided a significant advantage in delivering services to novice users. This art of integrating various services is known as Service Composition and its main purpose is to simplify the development process for web applications and facilitates reuse of services. It is one of the paradigms that enables services to end-users (i.e.service provisioning) through the outsourcing of web contents and it requires users to share and reuse services in more collaborative ways. Most service composers are effective at enabling integration of web contents, but they do not enable universal access across different groups of users. This is because, the currently existing content aggregators require complex interactions in order to create web applications (e.g., Web Service Business Process Execution Language (WS-BPEL)) as a result not all users are able to use such web tools. This trend demands changes in the web tools that end-users use to gain and share information, hence this research uses Mashups as a service composition technique to allow novice users to integrate publicly available Service Oriented Architecture (SOA) services, where there is a minimal active web application development. Mashups being the platforms that integrate disparate web Application Programming Interfaces (APIs) to create user defined web applications; presents a great opportunity for service provisioning. However, their usability for novice users remains invalidated since Mashup tools are not easy to use they require basic programming skills which makes the process of designing and creating Mashups difficult. This is because Mashup tools access heterogeneous web contents using public web APIs and the process of integrating them become complex since web APIs are tailored by different vendors. Moreover, the design of Mashup editors is unnecessary complex; as a result, users do not know where to start when creating Mashups. This research address the gap between Mashup tools and usability by the designing and implementing a semantically enriched Mashup tool to discover, annotate and compose APIs to improve the utilization of SOA services by novice users. The researchers conducted an analysis of the already existing Mashup tools to identify challenges and weaknesses experienced by novice Mashup users. The findings from the requirement analysis formulated the system usability requirements that informed the design and implementation of the proposed Mashup tool. The proposed architecture addressed three layers: composition, annotation and discovery. The researchers developed a simple Mashup tool referred to as soa-Services Provisioner (SerPro) that allowed novice users to create web application flexibly. Its usability and effectiveness was validated. The proposed Mashup tool enhanced the usability of SOA services, since data analysis and results showed that it was usable to novice users by scoring a System Usability Scale (SUS) score of 72.08. Furthermore, this research discusses the research limitations and future work for further improvements

On the Role of Context in the Design of Mobile Mashups

This paper presents a design methodology and an accompanying platform for the design and fast development of Context-Aware Mobile mashUpS (CAMUS). The approach is characterized by the role given to context as a first-class modeling dimension used to support i) the identification of the most adequate resources that can satisfy the users' situational needs and ii) the consequent tailoring at runtime of the provided data and functions. Context-based abstractions are exploited to generate models specifying how data returned by the selected services have to be merged and visualized by means of integrated views. Thanks to the adoption of Model-Driven Engineering (MDE) techniques, these models drive the flexible execution of the final mobile app on target mobile devices. A prototype of the platform, making use of novel and advanced Web and mobile technologies, is also illustrated