<p>Organizations often have information systems belonging to different computer generations. These systems contain much valuable data to the organizations concerned. However, these systems are often unable to communicate with each other, due to incompatibilities. Moreover, replacing these systems with new systems is also very costly. Therefore the latest trend is integrating the existing systems with each other with the help of different system integration technologies. When the systems are integrated with new technology they bring about various effects to the organizations in concern.</p><p>The purpose of this thesis is to find out how system integration affects an organization in the photo and home electronics branch, namely Expert. The questions that will be raised in this thesis are how does system integration affect the organization’s work processes and how does system integration affect the organisation’s employees. I have studied how system integration has affected the work processes and employees of the retail stores. In order to find answers to these questions three qualitative interviews were carried out. One interview took place in the central organization and the rest in retail stores in Linköping.</p><p>There are many reasons, which led Expert towards using system integration. Some of the main reasons are increased profitability and decreased costs for maintenance and upgrading of different systems. Further, the retail stores required better information channelling and streamlining of work processes in order to provide salesmen at retail stores possibility to concentrate more on customers by minimising administrative work.</p><p>I have found that system integration has affected the organization’s work processes and its employees both positively and negatively, in other words system integration has helped Expert to decrease administration work, provided salesmen at retail stores more time to deliver better service to customers, has automated key work processes saving time and reducing redundancy of work. Even if, the organization is quite satisfied with the benefits the existing system integration technologies have rendered to them, there are many more privileges, which can be achieved.</p>

<p>Distributing functionality of an application is in common use. Systems that are built with this feature in mind also have to provide high levels of dependability. One way of assuring availability of services is to tolerate faults in the system, thereby avoiding failures. Building distributed applications is not an easy task. To provide fault tolerance is even harder.</p><p>Using middlewares as mediators between hardware and operating systems on one hand and high-level applications on the other hand is a solution to the above difficult problems. It can help application writers by providing automatic generation of code supporting e.g. fault tolerance mechanisms, and by offering interoperability and language independence.</p><p>For over twenty years, the research community is producing results in the area of . However, experimental studies of different platforms are performed mostly by using made-up simple applications. Also, especially in case of CORBA, there is no fault-tolerant middleware totally conforming to the standard, and well studied in terms of trade-offs.</p><p>This thesis presents a fault-tolerant CORBA middleware built and evaluated using a realistic application running on top of it. Also, it contains results obtained after experiments with an alternative infrastructure implementing a robust fault-tolerant algorithm using basic CORBA. In the first infrastructure a problem is the existence of single points of failure. On the other hand, overheads and recovery times fall in acceptable ranges. When using the robust algorithm, the problem of single points of failure disappears. The problem here is the memory usage, and overhead values as well as recovery times that can become quite long.</p> / Report code: LiU-TEK-LIC-2002:55.

Thesis (Ph. D.)--Ohio State University, 2006. / Title from first page of PDF file. Includes bibliographical references (p. 146-157).

P2P Grid computing seeks the convergence of Grid and P2P technologies. Deploying a P2P Grid middleware on a set of computers enables an organization to automatically barter computing time with other Internet-connected organizations. Such P2P exchanges of computing time enable individual Peers, i.e. organizations, to transparently aggregate large amounts of computational power with minimal infrastructure requirements or administrative cost. Challenges arise from the requirement for scalability and robustness. Individual worker nodes are unreliable, as P2P Grids operate on unmanaged desktop computers. A specificity of P2P Grids is that each Peer can reclaim at any time the computational power of worker nodes supplied to other Peers, leading to bursts of execution preemption. These are the major contributions of our dissertation: * Firstly, we propose a new P2P Grid architecture, the Lightweight Bartering Grid (LBG). Through systematic cooperation between Grid nodes, the reliability of execution of computational requests is greater than the sum of the reliabilities of worker nodes. * Secondly, we propose a highly scalable data transfer architecture. It is based both on the BitTorrent P2P file sharing protocol and on the removal of the temporal cost of downloading redundant copies of input data files. * Thirdly, besides a middleware implementation of LBG, we also provide an implementation of a discrete-event simulator. Its originality resides in the weaving of the simulator code into the bartering code of the middleware, which is made possible through the virtualization of Grid nodes. This enables reproducible testing and accurate performance evaluation of the bartering policies because the Peers of a simulated Grid make the same bartering decisions as Peers deployed on real computers. The LBG architecture exhibits the following remarkable features: * The scheduling model supports the queueing of external requests and the architecture enables a flexible study of bartering policies. * The architecture is open, flexible, lightweight and facilitates software engineering. It enables the easy development, testing, evaluation and deployment of combinations of scheduling policies. * The architecture is fully P2P.

With the proliferation of mobile devices and wireless connectivity technologies, mobile social communities offer novel opportunities for targeted marketing by service or product providers. Unfortunately, marketers are still unable to realize the full potential of these markets due to their inability to effectively target right audiences. This thesis presents a novel middleware for identifying spontaneous social communities (SSCs) of mobile users in ad hoc networks in order to facilitate marketers' advertisements. The contributions of the presented work are two fold; the first is a novel model for SSCs that captures their unique dynamic nature, in terms of community structure and interest in different \textit{hot-topics} over time. These time-varying interests are represented through an inferred \textit{community profile prototype} that reflects dominant characteristics of community members. This prototype is then employed to facilitate the identification of new potential members. The selected community prototypes are also used by marketers to identify the right communities for their services or products promotions. The second contribution of this paper is novel distributed techniques for efficient calculation of the community prototypes and identification of potential community links. In contrast to traditional models of detecting fixed and mobile social networks that rely on pre-existing friendships among its members to predict new ones, the proposed model focuses on measuring the degree of similarity between the new user's profile and the profiles of members of each community in order to predict new users' relationships in the community. The adopted model of SSCs can foster many existing and new socially-aware applications such as recommender systems for social events and tools for collaborative work. It is also an ideal target for business-oriented applications such as short-message-service (SMS) advertisement messages, podcasting news feeds in addition to location/context-aware services. The performance of the proposed work was evaluated using the NetLogo platform where obtained experimental results demonstrate the achieved high degree of stability in the resulting communities in addition to the effectiveness of the proposed middleware in terms of the reduction in the number of routing messages required for advertisements.

Pervasive computing is an intuitive evolution of computing paradigms driven by the wide adoption of mobile devices and wireless networks. It introduces a novel way to support users in their everyday life based on open and dynamic environments populated with unobtrusive services able to perform user tasks on the fly. Nevertheless, supporting user tasks from a functional point of view is not enough to gain the user's satisfaction. Users instead require that their tasks meet a certain Quality of Service (QoS) level. QoS is indeed an inherent and primary requisite of users going along with their required tasks. In the context of pervasive environments, fulfilling user tasks while delivering satisfactory QoS brings about several challenges that are mainly due to the openness, dynamics, and limited underlying resources of these environments. These challenges are mainly about (i) the lack of common QoS understanding among users and service providers, (ii) determining and integra- ting, on the fly, the services available in the environment and able to fulfill the functional and QoS requirements of users, and (iii) adapting the provided services at run-time to cope with QoS fluctuations and ensure meeting user requirements. To cope with the aforementioned issues, we opt for a middleware-based solution. Middle- ware represents indeed the appropriate software system to deal with common concerns of user applications such as QoS. In particular, we opt for a specific kind of middleware, viz., Ser- vice Oriented Middleware (SOM). SOM can leverage middleware technologies and the Service Oriented Computing (SOC) paradigm to enable pervasive environments as dynamic service en- vironments. Particularly, SOM can provide middleware services that allow for supporting QoS of user applications offered by pervasive environments. This thesis presents a QoS-aware service-oriented middleware for pervasive environments. The main contributions of this middleware are : (1) a semantic end-to-end QoS model that enables shared understanding of QoS in pervasive environments, (2) an efficient QoS-aware service composition approach allowing to build service compositions able to fulfill the user functional and QoS requirements, and (3) a QoS-driven adaptation approach to cope with QoS fluctuations during the execution of service compositions. The proposed contributions are implemented within a middleware platform called QASOM and their efficiency is validated based on experimental results.

The Publish/Subscribe (pub/sub) model has been widely applied in a variety of application scenarios which demand loose-coupling and asynchronous communication between a large number of information sources and sinks. In this model, clients are granted the flexibility to specify their interests at a high level and rely on the pub/sub middleware for delivery of their publications of interest. This increased flexibility and ease of use on the client side results in substantial complexity on part of the pub/sub middleware implementation. Furthermore, for several reasons including improved scalability, availability and avoiding a single point of failure, the pub/sub middleware is commonly composed of a set of collaborating message routers, a.k.a. brokers. The distributed nature of this design further introduces new challenges in ensuring end-to-end reliability as well as efficiency of operation. These challenges are largely unique to the pub/sub model and hence absent in both point-to-point or multicast protocols. This thesis develops solutions that ensure the dependable operation of the pub/sub system by exploiting the notion of overlay neighborhoods in a formal manner. More specifically, brokers maintain information about their neighbors within a configurable distance in the pub/sub overlay and exploit this knowledge to construct alternative forwarding paths or make smart forwarding decisions that improves efficiency, bandwidth utilization and delivery delay, all at the same time. Furthermore, in the face of failures overlay neighborhoods enable fast reconstruction of forwarding paths in the system without compromising its reliability and availability. Finally, as an added benefit of overlay neighborhoods, this thesis develops large-scale algorithms that bring the advantages of the pub/sub model to the domain of file sharing and bulk content dissemination applications. Experimental evaluation results with deployments as large as 1000 nodes illustrate that the pub/sub system scales well and outperforms the traditional BitTorrent protocol in terms of content dissemination delay.

Interactions in the style of the ubiquitous computing paradigm are possible today, but only in handcrafted environments within one administrative and technological realm. This thesis describes an architecture (called Continuum), a design that realises the architecture, and a proof-of-concept implementation that brings ubiquitous computing to chaotic environments. Essentially, Continuum enables an ecology at the edge of the network, between users, competing service providers from overlapping administrative domains, competing internet service providers, content providers, and software developers that want to add value to the user experience. Continuum makes the ubiquitous computing functionality orthogonal to other application logic. Existing web applications are augmented for ubiquitous computing with functionality that is dynamically compiled and injected by a middleware proxy into the web pages requested by a web browser at the user?s mobile device. This enables adaptability to environment variability, manageability without user involvement, and expansibility without changes to the mobile. The middleware manipulates self-contained software units with precise functionality (called <i>frames</i>), which help the user interact with contextual services in conjunction with the data to which they are attached. The middleware and frame design explicitly incorporates the possibility of discrepancies between the assumptions of ubiquitous-computing software developers and field realities: multiple administrative domains, unavailable service, unavailable software, and missing contextual information. A framework for discovery and authorisation addresses the chaos inherent to the paradigm through the notion of <i>role assertions</i> acquired dynamically by the user. Each assertion represents service access credentials and contains bootstrapping points for service discovery on behalf of the holding user. A proof-of-concept prototype validates the design, and implements several frames that demonstrate general functionality, including driving discovery queries over multiple service discovery protocols and making equivalences between service types, across discovery protocols.

Organizations often have information systems belonging to different computer generations. These systems contain much valuable data to the organizations concerned. However, these systems are often unable to communicate with each other, due to incompatibilities. Moreover, replacing these systems with new systems is also very costly. Therefore the latest trend is integrating the existing systems with each other with the help of different system integration technologies. When the systems are integrated with new technology they bring about various effects to the organizations in concern. The purpose of this thesis is to find out how system integration affects an organization in the photo and home electronics branch, namely Expert. The questions that will be raised in this thesis are how does system integration affect the organization’s work processes and how does system integration affect the organisation’s employees. I have studied how system integration has affected the work processes and employees of the retail stores. In order to find answers to these questions three qualitative interviews were carried out. One interview took place in the central organization and the rest in retail stores in Linköping. There are many reasons, which led Expert towards using system integration. Some of the main reasons are increased profitability and decreased costs for maintenance and upgrading of different systems. Further, the retail stores required better information channelling and streamlining of work processes in order to provide salesmen at retail stores possibility to concentrate more on customers by minimising administrative work. I have found that system integration has affected the organization’s work processes and its employees both positively and negatively, in other words system integration has helped Expert to decrease administration work, provided salesmen at retail stores more time to deliver better service to customers, has automated key work processes saving time and reducing redundancy of work. Even if, the organization is quite satisfied with the benefits the existing system integration technologies have rendered to them, there are many more privileges, which can be achieved.

In addition to storing 70-75% of their data and business logic in legacy mainframe systems, global corporations have countless custom applications and off-the-shelf ERP products residing within their networks. Increasing competition and shrinking budgets have left managers scouring for innovative, cost-effective methods to maximize the potential of these enormous sunk costs. There is, as a result, an overwhelming need to not only web enable these existing legacy assets in order to quickly and cost-effectively deliver data to both customers and business partners alike, but also to amalgamate these disparate systems into a unified, homogeneous, real-time enterprise. Integration efforts to date, focused predominantly on the development of proprietary point-to-point adapters, have unfortunately proven to be a daunting task with countless failed projects and losses in the millions. The advent of XML web services does, however, have the potential to revolutionize existing integration strategies; the cost savings and ease of implementation associated with wrapping virtually all systems, past, present and future, with standardized, code-independent, data-centric interfaces is truly astounding. As the future success of this platform is, however, strictly dependent upon the interoperability of its endpoints, we have proposed several fundamental amendments to the existing flawed WSDL specification. A generic reference architecture, leveraging both this improved web services model as well as established component middleware technologies, is then proposed for the web enablement of legacy assets on an enterprise scale. In order to ensure the adoption of this methodology, a toolkit designed to automate the transformation has also been devised. This new paradigm will not only allow information to flow freely from deep within the enterprise, but will ultimately serve as the cornerstone of a new generation of enterprise integration solutions.