717 research outputs found

    DESIGNING HYPERMEDIA APPLICATIONS

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    We describe a step-by-step methodology for the design and construction of hypermedia applications and illustrate our approach using a small application. The Relationship Management Design (RMD) methodology begins with a data model of the application domain and proceeds through the design of the hypertext network, user interface and run-time dynamics finally concluding with the construction and testing of the target hypermedia system. Our ultimate objective is to use the RMD approach as the basis for the construction of computerized tools to support the design and development of hypermedia applications.Information Systems Working Papers Serie

    Characterization of wavelength interleaving in radio-over-fiber systems employing WDM/SCM

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    A radio-over-fiber (RoF) distribution system incorporating both sub-carrier multiplexing and wavelength division multiplexing (WDM) technologies is presented. This signal is directly modulated onto three high-speed lasers. Bragg filters are employed at the receiver base station in order to both demultiplex the required optical channel, and ensure that the detected signal is single side band (in order to overcome dispersion limitations of the link). System spectral efficiency is optimised by wavelength interleaving. The channel spacing between the WDM channels is varied and the system performance for different values of channel spacing and spectral efficiencies is investigated. The results show that wavelength interleaving is a reliable technique that could be used to increase the spectral efficiency of RoF systems

    HYPER MODEL MANAGEMENT SYSTEMS

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    In this paper we study the integration of Model Management and Hypertext systems to produce a Hyper Model Management System (HMMS). Model Management Systems constitute a class of software that is designed to support the construction, storage, retrieval, and use of models in the context of decision support systems (DSS). Hypertext systems allow users to split information into data fragments which the user cart browse to find information by taking non-linear paths in computer based texts. It has been suggested that DSSs should be conceived as environments which support decision making. We support the view that such environments can be readily provided for the subtask of model management by hypertext systems. The different kinds of model knowledge can be captured within different types of hypertext nodes and the relationships among these can be maintained by hypertext links. In this paper we describe some aspects of model management where hypertext will have a significant impact. However, plain hypertext is ineffective in dealing with the dynamic nature of information in model management tasks where data is revised, models executed, and reports are created on the fly. Dynamic domains require dynamic hypertexts. In this paper we also study the requirements for dynamic hypertexts. These can be satisfied within the class of generalized hypertext systems by using special hypertext nodes and links which we describe. We explore different architectures to integrate MMS and Hypertext systems to obtain HMMSs. This paper emphasizes the need for a shift to integrating Model Management and hypertext technologies.Information Systems Working Papers Serie

    HYPER MODEL MANAGEMENT SYSTEMS

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    In this paper we study the integration of Model Management and Hypertext systems to produce a Hyper Model Management System (HMMS). Model Management Systems constitute a class of software that is designed to support the construction, storage, retrieval, and use of models in the context of decision support systems (DSS). Hypertext systems allow users to split information into data fragments which the user can browse to find information by taking non-linear paths in computer based texts. It has been suggested that DSSs should be conceived as environments which support decision making. We support the view that such environments can be readily provided for the subtask of model management by hypertext systems. The different kinds of model knowledge can be captured within different types of nodes and the relationships among these can be maintained by hypertext links. In this paper we describe some aspects of model management where hypertext will have a significant impact. However, plain hypertext is ineffective in dealing with the dynamic nature of information in model management tasks where data is revised, models executed, and reports are created on the fly. Dynamic domains require dynamic hypertexts. In this paper we also study the requirements for dynamic hypertexts. These can be satisfied within the class of generalized hypertext systems by using special hypertext nodes and links which we describe. We explore different architectures to integrate MMS and Hypertext systems to obtain HMMSs. This paper emphasizes the need for a shift to integrated Model Management environments and proposes hypertext as an integrating technology.Information Systems Working Papers Serie

    Observation of Precipitation Evolution in Fe-Ni-Mn-Ti-Al Maraging Steel by Atom Probe Tomography

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    We describe the full decomposition sequence in an Fe-Ni-Mn-Ti-Al maraging steel during isothermal annealing at 550 °C. Following significant pre-precipitation clustering reactions within the supersaturated martensitic solid solution, (Ni,Fe)3Ti and (Ni,Fe)3(Al,Mn) precipitates eventually form after isothermal aging for ~60 seconds. The morphology of the (Ni,Fe)3Ti particles changes gradually during aging from predominantly plate-like to rod-like, and, importantly, Mn and Al were observed to segregate to these precipitate/matrix interfaces. The (Ni,Fe)3(Al,Mn) precipitates occurred at two main locations: uniformly within the matrix and at the periphery of the (Ni,Fe)3Ti particles. We relate this latter mode of precipitation to the Mn-Al segregation

    DESIGNING HYPERMEDIA APPLICATIONS

    Get PDF
    We describe a step-by-step methodology for the design and construction of hypermedia applications and illustrate our approach using a small application. The Relationship Management Design (RMD) methodology begins with a data model of the application domain and proceeds through the design of the hypertext network, user interface and run-time dynamics finally concluding with the construction and testing of the target hypermedia system. Our ultimate objective is to use the RMD approach as the basis for the construction of computerized tools to support the design and development of hypermedia applications.Information Systems Working Papers Serie

    HYPER MODEL MANAGEMENT SYSTEMS

    Get PDF
    In this paper we study the integration of Model Management and Hypertext systems to produce a Hyper Model Management System (HMMS). Model Management Systems constitute a class of software that is designed to support the construction, storage, retrieval, and use of models in the context of decision support systems (DSS). Hypertext systems allow users to split information into data fragments which the user cart browse to find information by taking non-linear paths in computer based texts. It has been suggested that DSSs should be conceived as environments which support decision making. We support the view that such environments can be readily provided for the subtask of model management by hypertext systems. The different kinds of model knowledge can be captured within different types of hypertext nodes and the relationships among these can be maintained by hypertext links. In this paper we describe some aspects of model management where hypertext will have a significant impact. However, plain hypertext is ineffective in dealing with the dynamic nature of information in model management tasks where data is revised, models executed, and reports are created on the fly. Dynamic domains require dynamic hypertexts. In this paper we also study the requirements for dynamic hypertexts. These can be satisfied within the class of generalized hypertext systems by using special hypertext nodes and links which we describe. We explore different architectures to integrate MMS and Hypertext systems to obtain HMMSs. This paper emphasizes the need for a shift to integrating Model Management and hypertext technologies.Information Systems Working Papers Serie

    HYPER MODEL MANAGEMENT SYSTEMS

    Get PDF
    In this paper we study the integration of Model Management and Hypertext systems to produce a Hyper Model Management System (HMMS). Model Management Systems constitute a class of software that is designed to support the construction, storage, retrieval, and use of models in the context of decision support systems (DSS). Hypertext systems allow users to split information into data fragments which the user can browse to find information by taking non-linear paths in computer based texts. It has been suggested that DSSs should be conceived as environments which support decision making. We support the view that such environments can be readily provided for the subtask of model management by hypertext systems. The different kinds of model knowledge can be captured within different types of nodes and the relationships among these can be maintained by hypertext links. In this paper we describe some aspects of model management where hypertext will have a significant impact. However, plain hypertext is ineffective in dealing with the dynamic nature of information in model management tasks where data is revised, models executed, and reports are created on the fly. Dynamic domains require dynamic hypertexts. In this paper we also study the requirements for dynamic hypertexts. These can be satisfied within the class of generalized hypertext systems by using special hypertext nodes and links which we describe. We explore different architectures to integrate MMS and Hypertext systems to obtain HMMSs. This paper emphasizes the need for a shift to integrated Model Management environments and proposes hypertext as an integrating technology.Information Systems Working Papers Serie

    Approaching Petavolts per meter plasmonics using structured semiconductors

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    A new class of strongly excited plasmonic modes that open access to unprecedented Petavolts per meter electromagnetic fields promise wide-ranging, transformative impact. These modes are constituted by large amplitude oscillations of the ultradense, delocalized free electron Fermi gas which is inherent in conductive media. Here structured semiconductors with appropriate concentration of n-type dopant are introduced to tune the properties of the Fermi gas for matched excitation of an electrostatic, surface "crunch-in" plasmon using readily available electron beams of ten micron overall dimensions and hundreds of picoCoulomb charge launched inside a tube. Strong excitation made possible by matching results in relativistic oscillations of the Fermi electron gas and uncovers unique phenomena. Relativistically induced ballistic electron transport comes about due to relativistic multifold increase in the mean free path. Acquired ballistic transport also leads to unconventional heat deposition beyond the Ohm's law. This explains the absence of observed damage or solid-plasma formation in experiments on interaction of conductive samples with electron bunches shorter than 10−13seconds\rm 10^{-13} seconds. Furthermore, relativistic momentum leads to copious tunneling of electron gas allowing it to traverse the surface and crunch inside the tube. Relativistic effects along with large, localized variation of Fermi gas density underlying these modes necessitate the kinetic approach coupled with particle-in-cell simulations. Experimental verification of acceleration and focusing of electron beams modeled here using tens of Gigavolts per meter fields excited in semiconductors with 1018cm−3\rm 10^{18}cm^{-3} free electron density will pave the way for Petavolts per meter plasmonics.Comment: 16 pages, 10 figure

    Profiling a decade of information systems frontiers’ research

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    This article analyses the first ten years of research published in the Information Systems Frontiers (ISF) from 1999 to 2008. The analysis of the published material includes examining variables such as most productive authors, citation analysis, universities associated with the most publications, geographic diversity, authors’ backgrounds and research methods. The keyword analysis suggests that ISF research has evolved from establishing concepts and domain of information systems (IS), technology and management to contemporary issues such as outsourcing, web services and security. The analysis presented in this paper has identified intellectually significant studies that have contributed to the development and accumulation of intellectual wealth of ISF. The analysis has also identified authors published in other journals whose work largely shaped and guided the researchers published in ISF. This research has implications for researchers, journal editors, and research institutions
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