9,445,615 research outputs found

    Information Flow Model for Commercial Security

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    Information flow in Discretionary Access Control (DAC) is a well-known difficult problem. This paper formalizes the fundamental concepts and establishes a theory of information flow security. A DAC system is information flow secure (IFS), if any data never flows into the hands of owner’s enemies (explicitly denial access list.

    Risk Information Seeking and Processing Model

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    On a Model for Integrated Information

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    In this paper we give a thorough presentation of a model proposed by Tononi et al. for modeling \emph{integrated information}, i.e. how much information is generated in a system transitioning from one state to the next one by the causal interaction of its parts and \emph{above and beyond} the information given by the sum of its parts. We also provides a more general formulation of such a model, independent from the time chosen for the analysis and from the uniformity of the probability distribution at the initial time instant. Finally, we prove that integrated information is null for disconnected systems

    Information Model of Cloud App Scaling with Variable Load Peaks

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    The information model of cloud app was done. It is a formal description of cloud app infrastructure and possible transitions between them, and cloud app current working state classification criterion. Cloud app current state classification criterion on the basis of Page-Hinckley method and calendar of events related to the cloud app working state considers the current state to one of three classes in order to improve the accuracy of prediction of cloud app workload.Proposed criterion was compared with standard offline criterion that analyzes information about the entire time series of cloud app through a considerable time after the events that lead to the load peak, and therefore can\u27t be used when grading in real time. It is shown that the classification of cloud app state is consistent in 92 % of cases.The resulting information model of cloud app scaling with variable load peaks can be used as a component of information technology for cloud app scaling with variable load peaks

    Developing information systems strategies : a model

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    Cranfield School of Managemen

    Information Storage in the Stochastic Ising Model

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    Most information systems store data by modifying the local state of matter, in the hope that atomic (or sub-atomic) local interactions would stabilize the state for a sufficiently long time, thereby allowing later recovery. In this work we initiate the study of information retention in locally-interacting systems. The evolution in time of the interacting particles is modeled via the stochastic Ising model (SIM). The initial spin configuration X0X_0 serves as the user-controlled input. The output configuration XtX_t is produced by running tt steps of the Glauber chain. Our main goal is to evaluate the information capacity In(t)maxpX0I(X0;Xt)I_n(t)\triangleq\max_{p_{X_0}}I(X_0;X_t) when the time tt scales with the size of the system nn. For the zero-temperature SIM on the two-dimensional n×n\sqrt{n}\times\sqrt{n} grid and free boundary conditions, it is easy to show that In(t)=Θ(n)I_n(t) = \Theta(n) for t=O(n)t=O(n). In addition, we show that on the order of n\sqrt{n} bits can be stored for infinite time in striped configurations. The n\sqrt{n} achievability is optimal when tt\to\infty and nn is fixed. One of the main results of this work is an achievability scheme that stores more than n\sqrt{n} bits (in orders of magnitude) for superlinear (in nn) times. The analysis of the scheme decomposes the system into Ω(n)\Omega(\sqrt{n}) independent Z-channels whose crossover probability is found via the (recently rigorously established) Lifshitz law of phase boundary movement. We also provide results for the positive but small temperature regime. We show that an initial configuration drawn according to the Gibbs measure cannot retain more than a single bit for tecn14+ϵt\geq e^{cn^{\frac{1}{4}+\epsilon}}. On the other hand, when scaling time with β\beta, the stripe-based coding scheme (that stores for infinite time at zero temperature) is shown to retain its bits for time that is exponential in β\beta

    Mutual information in the Tangled Nature Model

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    We consider the concept of mutual information in ecological networks, and use this idea to analyse the Tangled Nature model of co-evolution. We show that this measure of correlation has two distinct behaviours depending on how we define the network in question: if we consider only the network of viable species this measure increases, whereas for the whole system it decreases. It is suggested that these are complimentary behaviours that show how ecosystems can become both more stable and better adapted.Comment: 7 pages, 5 figures. To appear in Ecological Modellin
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