3,786 research outputs found
Completion problem with partial correlation vines
No full textAbstractThis paper extends the results in [D. Kurowicka, R.M. Cooke, A parametrization of positive definite matrices in terms of partial correlation vines, Linear Algebra Appl. 372 (2003) 225–251]. We show that a partial correlation vine represents a factorization of the determinant of the correlation matrix. We show that the graph of an incompletely specified correlation matrix is chordal if and only if it can be represented as an m-saturated incomplete vine, that is, an incomplete vine for which all edges corresponding to membership-descendents (m-descendents for short) of a specified edge are specified. This enables us to find the set of completions, and also the completion with maximal determinant for matrices corresponding to chordal graphs
Value of Information Based Design of Control Software
No full textElectrical Engineering, Mathematics and Computer Scienc
Algorithms for non-parametric Bayesian belief nets
No full textElectrical Engineering, Mathematics and Computer Scienc
High dimensional dependence: Copulae, sensitivity, sampling
No full textElectrical Engineering, Mathematics and Computer Scienc
Discrete Decisions with Model Validation using Probabilistic Inversion
No full textDelft Institute of Applied MathematicsElectrical Engineering, Mathematics and Computer Scienc
Risk based decision support for new air traffic operations with reduced aircraft separation
No full textWith the steady increase in air traffic, the aviation system is under continuous pressure to increase aircraft handling capacity. Various new Air Traffic Management systems and flight procedures are proposed to increase airport capacity while maintaining the required level of safety. Newly proposed systems to cope with wake turbulence and allowing reduction of wake vortex separation minima include the ATC-Wake system (for air traffic controllers) and the I-Wake system (for pilots). An increase in runway capacity may also be achieved by using parallel runways more effectively or by designing new and advanced flight procedures. For all these procedures, International Civil Aviation Organization (ICAO) standards and best practices do not exist and new safety assessment methodologies are developed and applied. The approach taken is to apply risk based decision making to support the introduction of new air traffic operations and systems. There are several fundamental questions to be resolved: -What is the safety level of the current air traffic operations? -Are the separation minima for the current air traffic operations overly conservative? -Can the current separation minima be reduced safely? -What are the requirements for the newly proposed air traffic operations and systems? To solve these questions new risk assessment models and risk criteria are developed and applied. The two most capacity limiting risk events addressed are wake vortex encounters and the collision risk between aircraft. The safety assessments show that the current wake vortex separation minima, which depend on aircraft weight, are often overly conservative. Introduction of wind dependent aircraft separation rules will enable increase of airport capacity, while maintaining safety. It is also shown that specific missed approach procedures, which take into account local airport layout characteristics, will lead to airport capacity increase. This is shown for Amsterdam Airport Schiphol runway 22. The results from wake vortex risk analyses are used to support the design and setting of requirements for the ATC-Wake and I-Wake systems and concepts of operation. The results from collision risk analyses are used by the Dutch Civil Aviation Authority and Air Traffic Control Centre and are brought forward successfully to ICAO.Electrical Engineering, Mathematics and Computer Scienc
Probabilistic inversion in uncertainty analysis: And related topics
No full textElectrical Engineering, Mathematics and Computer Scienc
Techniques in Representing High Dimensional Distributions
No full textElectrical Engineering, Mathematics and Computer Scienc
Food Benefit-Risk Assessment with Bayesian Belief Networks and Multivariable Exposure-Response
No full textApplied mathematicsElectrical Engineering, Mathematics and Computer Scienc
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