3,548 research outputs found

    Power Systems Monitoring and Control using Telecom Network Management Standards

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    Historically, different solutions have been developed for power systems control and telecommunications network management environments. The former was characterized by proprietary solutions, while the latter has been involved for years in a strong standardization process guided by criteria of openness. Today, power systems control standardization is in progress, but it is at an early stage compared to the telecommunications management area, especially in terms of information modeling. Today, control equipment tends to exhibit more computational power, and communication lines have increased their performance. These trends hint at some conceptual convergence between power systems and telecommunications networks from a management perspective. This convergence leads us to suggest the application of well-established telecommunications management standards for power systems control. This paper shows that this is a real medium-to-long term possibility

    Experiences in Integrated Multi-Domain Service Management

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    Increased competition, complex service provision chains and integrated service offerings require effective techniques for the rapid integration of telecommunications services and management systems over multiple organisational domains. This paper presents some of the results of practical development work in this area, detailing the technologies and standards used, the architectural approach taken and the application of this approach to specific services. This work covers the integration of multimedia services, broadband networks, service management and network management, though the detailed examples given focus specifically on the integration of services and service management

    Applying Service Engineering Principles to TMN Systems

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    Recent work in distributed and telecommunication systems has become increasingly oriented towards applications in a global open market in telecommunications services, as the effects of liberalisation take hold. The areas of network and service management will be essential to competitiveness in this market, however the technologies and system development techniques widely used today (i.e. SNMP and CMIP) were conceived to address the needs of large corporate data networks and monolithic public telecommunication networks. How these technologies and techniques can be applied to management in an open market environment is not currently well defined. This paper describes some of the work of the RACE II PROJECT PREPARE in its application of ITU-T TMN recommendations to management solutions in an open services environment. In particular it describes the engineering approach taken to developing TMN systems in an attempt to tailor them to such an environment

    Multi-service management in a multi-provider environment

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    As the spread of digital networks makes access to data communications globally available, the interest of communication service providers is switching away from the provision of these bearer networks and towards the provision of the value added services that will operate over them. At the same time the liberalisation of telecommunication markets is precipitating a dramatic change in the profile of communication service providers. In this complex telecommunications markets the open management, not only of the networks, but of the services themselves will become increasingly important. The large number and diversity of roles of the market players makes the management of inter-organisational relationships fundamentally important to the management of services. The ITU's series of recommendations on the telecommunication management network (TMN) provides a basis for inter-domain management, however, this and other standards have so far concentrated on the management of individual network components and of networks operated by single organisations. This paper provides an initial example of how the management of multiple services in a complex multi-player market can be modelled using TMN techniques for implementation on existing management platforms. The paper begins by briefly outlining current work in this field before describing aspects of this multi-player multi-service management problem and how they can be modelled and implemented in a real system

    Inter-Domain Integration of Services and Service Management

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    The evolution of the global telecommunications industry into an open services market presents developers of telecommunication service and management systems with many new challenges. Increased competition, complex service provision chains and integrated service offerings require effective techniques for the rapid integration of service and management systems over multiple organisational domains. These integration issues have been examined in the ACTS project Prospect by developing a working set of integrated, managed telecommunications services for a user trial. This paper presents the initial results of this work detailing the technologies and standards used, the architectural approach taken and the application of this approach to specific services

    Transplanckian bremsstrahlung and black hole production

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    Classical gravitational bremsstrahlung in particle collisions at transplanckian energies is studied in M4×Td{\mathcal M}_4\times {\mathcal T}^d. The radiation efficiency ϵ≡Erad/Einitial\epsilon\equiv E_{\rm rad}/E_{\rm initial} is computed in terms of the Schwarzschild radius rS(s)r_S(\sqrt{s}), the impact parameter bb and the Lorentz factor γcm\gamma_{\rm cm} and found to be ϵ=Cd(rS/b)3d+3γcm2d+1\epsilon=C_d (r_S/b)^{3d+3} \gamma_{\rm cm}^{2d+1}, larger than previous estimates by many powers of γcm≫1\gamma_{\rm cm}\gg 1. The result is reliable for impact parameters in the overlap of rSλCr_S\lambda_C, with bcb_c marking (for d≠0d\neq 0) the loss of the notion of classical trajectories and λC≡ℏ/mc\lambda_C\equiv \hbar/mc the Compton length of the scattered particles. The condition on ss and mm for extreme radiation damping and (presumably) no black hole production is also derived.Comment: 4 pages, revtex 4. The discussion section is changed to better clarify the region of validity of our calculation. The physical conclusions and the abstract are modified accordingly. A few more references added. We just added the preprint number CCTP-2010-1

    Intelligent Integrated Management for Telecommunication Networks

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    As the size of communication networks keeps on growing, faster connections, cooperating technologies and the divergence of equipment and data communications, the management of the resulting networks gets additional important and time-critical. More advanced tools are needed to support this activity. In this article we describe the design and implementation of a management platform using Artificial Intelligent reasoning technique. For this goal we make use of an expert system. This study focuses on an intelligent framework and a language for formalizing knowledge management descriptions and combining them with existing OSI management model. We propose a new paradigm where the intelligent network management is integrated into the conceptual repository of management information called Managed Information Base (MIB). This paper outlines the development of an expert system prototype based in our propose GDMO+ standard and describes the most important facets, advantages and drawbacks that were found after prototyping our proposal

    Time Evolution of Non-Lethal Infectious Diseases: A Semi-Continuous Approach

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    A model describing the dynamics related to the spreading of non-lethal infectious diseases in a fixed-size population is proposed. The model consists of a non-linear delay-differential equation describing the time evolution of the increment in the number of infectious individuals and depends upon a limited number of parameters. Predictions are in good qualitative agreement with data on influenza.Comment: 21 page

    Sequential Monte Carlo EM for multivariate probit models

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    Multivariate probit models (MPM) have the appealing feature of capturing some of the dependence structure between the components of multidimensional binary responses. The key for the dependence modelling is the covariance matrix of an underlying latent multivariate Gaussian. Most approaches to MLE in multivariate probit regression rely on MCEM algorithms to avoid computationally intensive evaluations of multivariate normal orthant probabilities. As an alternative to the much used Gibbs sampler a new SMC sampler for truncated multivariate normals is proposed. The algorithm proceeds in two stages where samples are first drawn from truncated multivariate Student tt distributions and then further evolved towards a Gaussian. The sampler is then embedded in a MCEM algorithm. The sequential nature of SMC methods can be exploited to design a fully sequential version of the EM, where the samples are simply updated from one iteration to the next rather than resampled from scratch. Recycling the samples in this manner significantly reduces the computational cost. An alternative view of the standard conditional maximisation step provides the basis for an iterative procedure to fully perform the maximisation needed in the EM algorithm. The identifiability of MPM is also thoroughly discussed. In particular, the likelihood invariance can be embedded in the EM algorithm to ensure that constrained and unconstrained maximisation are equivalent. A simple iterative procedure is then derived for either maximisation which takes effectively no computational time. The method is validated by applying it to the widely analysed Six Cities dataset and on a higher dimensional simulated example. Previous approaches to the Six Cities overly restrict the parameter space but, by considering the correct invariance, the maximum likelihood is quite naturally improved when treating the full unrestricted model.Comment: 26 pages, 2 figures. In press, Computational Statistics & Data Analysi

    Aspects of the UV/IR correspondence : energy broadening and string fluctuations

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    We show that a source which radiates in the vacuum of the strongly coupled N=4 SYM theory produces an energy distribution which, in the supergravity approximation, has the same space-time pattern as the corresponding classical distribution: the radiation propagates at the speed of light without broadening. We illustrate this on the basis of several examples: a small perturbation propagating down a steady string, a massless particle falling into AdS_5, and the decay of a time-like wave-packet. A similar observation was made in Phys. Rev. D81 (2010) 126001 for the case of a rotating string. In all these cases, the absence of broadening is related to the fact that the energy backreaction on the boundary arises exclusively from the bulk perturbation at, or near, the boundary. This is so since bulk sources which propagate in AdS_5 at the speed of light do not generate any energy on the boundary. We interpret these features as an artifact of the supergravity approximation, which fails to encode quantum mechanical fluctuations that should be present even in the strong coupling limit. We argue that such fluctuations should enter the dual string theory as longitudinal string fluctuations, which are not suppressed at strong coupling. We heuristically estimate the effects of such fluctuations and argue that they restore the broadening of the radiation, in agreement with expectations from both quantum mechanics and the ultraviolet/infrared correspondence.Comment: 47 page
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