875 research outputs found
Predicting Network Attacks Using Ontology-Driven Inference
Graph knowledge models and ontologies are very powerful modeling and re
asoning tools. We propose an effective approach to model network attacks and
attack prediction which plays important roles in security management. The goals
of this study are: First we model network attacks, their prerequisites and
consequences using knowledge representation methods in order to provide
description logic reasoning and inference over attack domain concepts. And
secondly, we propose an ontology-based system which predicts potential attacks
using inference and observing information which provided by sensory inputs. We
generate our ontology and evaluate corresponding methods using CAPEC, CWE, and
CVE hierarchical datasets. Results from experiments show significant capability
improvements comparing to traditional hierarchical and relational models.
Proposed method also reduces false alarms and improves intrusion detection
effectiveness.Comment: 9 page
Lagrangian and Eulerian Descriptions in Solid Mechanics and Their Numerical Solutions in hpk Framework
In this thesis mathematical models for a deforming solid medium are derived using conservation laws in Lagrangian as well as Eulerian descriptions. First, most general forms of the mathematical models permitting compressibility of the matter are considered which are then specialized for incompressible medium. Development of constitutive equations central to the validity of the mathematical models is considered Numerical solution of these mathematical models are obtained using finite element method based on h,p,k mathematical and computational framework in which the integral forms are variationally consistent and hence the resulting computational processes are unconditionally stable. Details of the constitutive equations in both Lagrangian and Eulerian descriptions are presented. A variety of model problems are chosen for numerical studies. The wave propagation model problems are considered for numerical studies to investiage (i) Behaviors and limitations of constitutive models in both descriptions (ii) Overall benefits and drawbacks of Lagrangian and Eulerian descriptions
Dynamic Response of Highways and Airport Pavements to Falling Weight Deflectometer Loading
An elasto-dynamic analysis of pavement response to Falling Weight Deflectometer (FWD) impact is presented. The analysis is based on the Fourier series synthesis of a solution for periodic loading of elastic or visco-elastic horizontally layered strata. The method is applied to selected flexible and rigid pavement sections. Pavement deflection predictions at several geophone locations for various pavements are presented. Comparison between dynamic and static deflection predictions reveal the importance of inertial effects in the prediction of pavement response. Conventional static analysis can yield significantly different results and, therefore may lead to erroneous (unconservative) predictions of pavement moduli back-calculated from deflection data. Deflection basins together with deflection contours for several pavements are also presented in order to give an insight into the progressive deformation of pavements during and after FWD impact
Surface Areas of Some Interconnection Networks
An interesting property of an interconnected network (G) is the number of nodes at distance i from an arbitrary processor (u), namely the node centered surface area. This is an important property of a network due to its applications in various fields of study.
In this research, we investigate on the surface area of two important interconnection networks, (n, k)-arrangement graphs and (n, k)-star graphs.
Abundant works have been done to achieve a formula for the surface area of these two classes of graphs, but in general, it is not trivial to find an algorithm to compute the surface area of such graphs in polynomial time or to find an explicit formula with polynomially many terms in regards to the graph's parameters. Among these studies, the most efficient formula in terms of computational complexity is the one that Portier and Vaughan proposed which allows us to compute the surface area of a special case of (n, k)-arrangement and (n, k)-star graphs when k = n-1, in linear time which is a tremendous improvement over the naive solution with complexity order of O(n * n!). The recurrence we propose here has the linear computational complexity as well, but for a much wider family of graphs, namely A(n, k) for any arbitrary n and k in their defined range. Additionally, for (n, k)-star graphs we prove properties that can be used to achieve a simple recurrence for its surface area
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