3,676 research outputs found

    An intruder model for verifying termination in security protocols

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    We formally describe an intruder that is suitable for checking fairness properties of security protocols. The intruder is proved to be equivalent to the Dolev-Yao intruder that respects the resilient communication channels assumption, in the sense that, if a fairness property holds in one of these models, it also holds in the other

    IS KUWAIT TV DIGLOSSIC? A SOCIOLINGUISTIC INVESTIGATION

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    Diglossia is a sociolinguistic term refers to the use of two varieties of one language in a given community; one is regarded as the high variety and the other as a low variety. This paper is a qualitative study thatinvestigates diglossia in various Kuwaiti TV stations. It attempts to mainly see if the two varieties are used differently whenever there is a change of topic in TV programs. Topics investigated include news, programs discussing political issues, cooking, sports, religion, and fashion. The researchers made sure that all programs chosen for investigation are presented by Kuwaitis. Data collected for this study relied mainly on observations and videotaping which took five months duration. Data was then phonetically transcribed and qualitatively analyzed.Speech extracts indicating the use of either H or L variety are demonstrated where necessary. The analysis showed that diglossia extensively exists in all the Kuwaiti TVchannels under investigation. Such a study may, to some extent, draw some generalizations about diglossia in Kuwait due to the fact that these channels present a variety of diglossic behaviors in different settings by different Kuwaiti speakers

    Fast kk-NNG construction with GPU-based quick multi-select

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    In this paper we describe a new brute force algorithm for building the kk-Nearest Neighbor Graph (kk-NNG). The kk-NNG algorithm has many applications in areas such as machine learning, bio-informatics, and clustering analysis. While there are very efficient algorithms for data of low dimensions, for high dimensional data the brute force search is the best algorithm. There are two main parts to the algorithm: the first part is finding the distances between the input vectors which may be formulated as a matrix multiplication problem. The second is the selection of the kk-NNs for each of the query vectors. For the second part, we describe a novel graphics processing unit (GPU) -based multi-select algorithm based on quick sort. Our optimization makes clever use of warp voting functions available on the latest GPUs along with use-controlled cache. Benchmarks show significant improvement over state-of-the-art implementations of the kk-NN search on GPUs

    Access Control Synthesis for Physical Spaces

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    Access-control requirements for physical spaces, like office buildings and airports, are best formulated from a global viewpoint in terms of system-wide requirements. For example, "there is an authorized path to exit the building from every room." In contrast, individual access-control components, such as doors and turnstiles, can only enforce local policies, specifying when the component may open. In practice, the gap between the system-wide, global requirements and the many local policies is bridged manually, which is tedious, error-prone, and scales poorly. We propose a framework to automatically synthesize local access control policies from a set of global requirements for physical spaces. Our framework consists of an expressive language to specify both global requirements and physical spaces, and an algorithm for synthesizing local, attribute-based policies from the global specification. We empirically demonstrate the framework's effectiveness on three substantial case studies. The studies demonstrate that access control synthesis is practical even for complex physical spaces, such as airports, with many interrelated security requirements

    Competing Universalities in Kardar-Parisi-Zhang (KPZ) Growth Models

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    We report on the universality of height fluctuations at the crossing point of two interacting (1+1)-dimensional Kardar-Parisi-Zhang (KPZ) interfaces with curved and flat initial conditions. We introduce a control parameter p as the probability for the initially flat geometry to be chosen and compute the phase diagram as a function of p. We find that the distribution of the fluctuations converges to the Gaussian orthogonal ensemble Tracy-Widom (TW) distribution for p0.5. For p=0.5 where the two geometries are equally weighted, the behavior is governed by an emergent Gaussian statistics in the universality class of Brownian motion. We propose a phenomenological theory to explain our findings and discuss possible applications in nonequilibrium transport and traffic flow.Comment: 5 pages, 6 figures, Phys. Rev. Lett. (2019) (accepted

    Information Surfaces in Systems Biology and Applications to Engineering Sustainable Agriculture

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    Systems biology of plants offers myriad opportunities and many challenges in modeling. A number of technical challenges stem from paucity of computational methods for discovery of the most fundamental properties of complex dynamical systems. In systems engineering, eigen-mode analysis have proved to be a powerful approach. Following this philosophy, we introduce a new theory that has the benefits of eigen-mode analysis, while it allows investigation of complex dynamics prior to estimation of optimal scales and resolutions. Information Surfaces organizes the many intricate relationships among "eigen-modes" of gene networks at multiple scales and via an adaptable multi-resolution analytic approach that permits discovery of the appropriate scale and resolution for discovery of functions of genes in the model plant Arabidopsis. Applications are many, and some pertain developments of crops that sustainable agriculture requires.Comment: 24 Pages, DoCEIS 1
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