42,724 research outputs found

    Managing Flexibility in Distributed Information Systems Architectures

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    Conktw~tivepressures are forcing organizations to be agile and flexible. Response to changing environmental conditions is an important factorindeterminingcorporateperformance. Organizationalflexibilityisinturncloselyrelatedtothemanagementofinformation systems. Flexibility of information systems needs to be actively managed. Information systems in organizations have evolved from being a function of a centralized MIS department to a function dependent on a distributed collection of information systems resources (hardware,software,andpeople). ThisdistributedcollectionofresourceshasbeenreferredtoastheDistributedInformationSystems Architecture. Managing flexibility in distributed information systems architectures is an interesting and challenging problem. The importance of flexibilityboth at the organizational and information systems levels has been recognized by research in management (Bahrami 1992), operations management (Sethi 1990), and MIS (Lacity,Willcocks and Feeny 1995). However, flexibility in distributed informationsystemarchitectureshasnotbeenexaminedindetail. Flexibilityindistributedinformationsystemarchitecturescanbe of several types. Each type of flexibilityhas distinct characteristics. Understanding different types of flexibility in the context of distributedinformationsystemarchitectures isthereforeextremelyimportant. The operations management literature on flexibility is used as a starting point to categorize various types of flexibility. Analysis of secondary data using grounded theory(Strauss and Corbin 1990) is employed to identifyseveral different types of flexibility. Secondary data used consists of articles on outsourcing and management of information systems from academic publications as well as from practitioner publications such as Datamation,InformationWeek,etc. A taxonomyfor understanding flexibilityin distributed information system architectures is developed. Iherelationshipbeaweenvarioustypesofflexibilityanddifferentinformationsystemsfunctionsisexplored. Thistaxonomyofflexibility, as well as the relationship between types of flexibility, information system functions, and resource requirements has important implications for evaluation of outsourcing decisions

    Using real options to select stable Middleware-induced software architectures

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    The requirements that force decisions towards building distributed system architectures are usually of a non-functional nature. Scalability, openness, heterogeneity, and fault-tolerance are examples of such non-functional requirements. The current trend is to build distributed systems with middleware, which provide the application developer with primitives for managing the complexity of distribution, system resources, and for realising many of the non-functional requirements. As non-functional requirements evolve, the `coupling' between the middleware and architecture becomes the focal point for understanding the stability of the distributed software system architecture in the face of change. It is hypothesised that the choice of a stable distributed software architecture depends on the choice of the underlying middleware and its flexibility in responding to future changes in non-functional requirements. Drawing on a case study that adequately represents a medium-size component-based distributed architecture, it is reported how a likely future change in scalability could impact the architectural structure of two versions, each induced with a distinct middleware: one with CORBA and the other with J2EE. An option-based model is derived to value the flexibility of the induced-architectures and to guide the selection. The hypothesis is verified to be true for the given change. The paper concludes with some observations that could stimulate future research in the area of relating requirements to software architectures

    Intellectual Capital Architectures and Bilateral Learning: A Framework For Human Resource Management

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    Both researchers and managers are increasingly interested in how firms can pursue bilateral learning; that is, simultaneously exploring new knowledge domains while exploiting current ones (cf., March, 1991). To address this issue, this paper introduces a framework of intellectual capital architectures that combine unique configurations of human, social, and organizational capital. These architectures support bilateral learning by helping to create supplementary alignment between human and social capital as well as complementary alignment between people-embodied knowledge (human and social capital) and organization-embodied knowledge (organizational capital). In order to establish the context for bilateral learning, the framework also identifies unique sets of HR practices that may influence the combinations of human, social, and organizational capital

    Middleware Technologies for Cloud of Things - a survey

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    The next wave of communication and applications rely on the new services provided by Internet of Things which is becoming an important aspect in human and machines future. The IoT services are a key solution for providing smart environments in homes, buildings and cities. In the era of a massive number of connected things and objects with a high grow rate, several challenges have been raised such as management, aggregation and storage for big produced data. In order to tackle some of these issues, cloud computing emerged to IoT as Cloud of Things (CoT) which provides virtually unlimited cloud services to enhance the large scale IoT platforms. There are several factors to be considered in design and implementation of a CoT platform. One of the most important and challenging problems is the heterogeneity of different objects. This problem can be addressed by deploying suitable "Middleware". Middleware sits between things and applications that make a reliable platform for communication among things with different interfaces, operating systems, and architectures. The main aim of this paper is to study the middleware technologies for CoT. Toward this end, we first present the main features and characteristics of middlewares. Next we study different architecture styles and service domains. Then we presents several middlewares that are suitable for CoT based platforms and lastly a list of current challenges and issues in design of CoT based middlewares is discussed.Comment: http://www.sciencedirect.com/science/article/pii/S2352864817301268, Digital Communications and Networks, Elsevier (2017

    Middleware Technologies for Cloud of Things - a survey

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    The next wave of communication and applications rely on the new services provided by Internet of Things which is becoming an important aspect in human and machines future. The IoT services are a key solution for providing smart environments in homes, buildings and cities. In the era of a massive number of connected things and objects with a high grow rate, several challenges have been raised such as management, aggregation and storage for big produced data. In order to tackle some of these issues, cloud computing emerged to IoT as Cloud of Things (CoT) which provides virtually unlimited cloud services to enhance the large scale IoT platforms. There are several factors to be considered in design and implementation of a CoT platform. One of the most important and challenging problems is the heterogeneity of different objects. This problem can be addressed by deploying suitable "Middleware". Middleware sits between things and applications that make a reliable platform for communication among things with different interfaces, operating systems, and architectures. The main aim of this paper is to study the middleware technologies for CoT. Toward this end, we first present the main features and characteristics of middlewares. Next we study different architecture styles and service domains. Then we presents several middlewares that are suitable for CoT based platforms and lastly a list of current challenges and issues in design of CoT based middlewares is discussed.Comment: http://www.sciencedirect.com/science/article/pii/S2352864817301268, Digital Communications and Networks, Elsevier (2017

    Pattern Reification as the Basis for Description-Driven Systems

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    One of the main factors driving object-oriented software development for information systems is the requirement for systems to be tolerant to change. To address this issue in designing systems, this paper proposes a pattern-based, object-oriented, description-driven system (DDS) architecture as an extension to the standard UML four-layer meta-model. A DDS architecture is proposed in which aspects of both static and dynamic systems behavior can be captured via descriptive models and meta-models. The proposed architecture embodies four main elements - firstly, the adoption of a multi-layered meta-modeling architecture and reflective meta-level architecture, secondly the identification of four data modeling relationships that can be made explicit such that they can be modified dynamically, thirdly the identification of five design patterns which have emerged from practice and have proved essential in providing reusable building blocks for data management, and fourthly the encoding of the structural properties of the five design patterns by means of one fundamental pattern, the Graph pattern. A practical example of this philosophy, the CRISTAL project, is used to demonstrate the use of description-driven data objects to handle system evolution.Comment: 20 pages, 10 figure

    Enabling Disaster Resilient 4G Mobile Communication Networks

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    The 4G Long Term Evolution (LTE) is the cellular technology expected to outperform the previous generations and to some extent revolutionize the experience of the users by taking advantage of the most advanced radio access techniques (i.e. OFDMA, SC-FDMA, MIMO). However, the strong dependencies between user equipments (UEs), base stations (eNBs) and the Evolved Packet Core (EPC) limit the flexibility, manageability and resiliency in such networks. In case the communication links between UEs-eNB or eNB-EPC are disrupted, UEs are in fact unable to communicate. In this article, we reshape the 4G mobile network to move towards more virtual and distributed architectures for improving disaster resilience, drastically reducing the dependency between UEs, eNBs and EPC. The contribution of this work is twofold. We firstly present the Flexible Management Entity (FME), a distributed entity which leverages on virtualized EPC functionalities in 4G cellular systems. Second, we introduce a simple and novel device-todevice (D2D) communication scheme allowing the UEs in physical proximity to communicate directly without resorting to the coordination with an eNB.Comment: Submitted to IEEE Communications Magazin

    Building Programmable Wireless Networks: An Architectural Survey

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    In recent times, there have been a lot of efforts for improving the ossified Internet architecture in a bid to sustain unstinted growth and innovation. A major reason for the perceived architectural ossification is the lack of ability to program the network as a system. This situation has resulted partly from historical decisions in the original Internet design which emphasized decentralized network operations through co-located data and control planes on each network device. The situation for wireless networks is no different resulting in a lot of complexity and a plethora of largely incompatible wireless technologies. The emergence of "programmable wireless networks", that allow greater flexibility, ease of management and configurability, is a step in the right direction to overcome the aforementioned shortcomings of the wireless networks. In this paper, we provide a broad overview of the architectures proposed in literature for building programmable wireless networks focusing primarily on three popular techniques, i.e., software defined networks, cognitive radio networks, and virtualized networks. This survey is a self-contained tutorial on these techniques and its applications. We also discuss the opportunities and challenges in building next-generation programmable wireless networks and identify open research issues and future research directions.Comment: 19 page
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