- document
-
Kraneveld, M.R. (author)In conventional practice extreme design conditions for offshore structures are obtained very conservatively by extrapolating 3-hourly statistics of wind, wave and current data to a (say) 100 year return level, assuming that the 100-year extremes occur simultaneously and act in the same direction. This study involves an alternative approach...master thesis 1991
- document
-
Roos, N. (author)In this thesis, which consists of two parts, two different subjects are discussed. In the first part of the thesis a logic for reasoning with inconsistent knowledge will be described. The second part of the thesis contains a proposal for to view a reasoning process as a process of constructing a partial model of the world we are reasoning about....report 1991
- document
- Wal, M. van der (author) report 1990
- document
-
Hekmat, R. (author)The probability of capture in mobile radio networks with fading, interference and noise is studied. Capture probability in slow and fast fading channels are found through distinct approaches and for three different carrier synchronization methods. The effect of error correcting codes on capture probability in fast fading channels, and...master thesis 1990
- document
-
Van Epen, D. (author), Nieuwenhuijs, J. (author)From the ten breakwaters we selected, on the amount of reliable information available, one breakwater in Richards Bay, South Africa. The preliminary check, made in the first phase, showed the design of this breakwater was rather conservative. From surveys done on the breakwater although, it appeared that the armor-layer was damaged in storms...master thesis 1989
- document
-
Roos, N. (author)In this paper two kinds of uncertainty, general and specific uncertainty, are distinguished. General uncertainty denotes an uncertainty about which objects of a class belong to a relation. Sentences in which it occurs can be view as describing incomplete knowledge. An example of such a sentence is: "Most humans have brown eyes". Specific...report 1989
- document
-
Noback, R. (author)A method is described to generate a random Gaussian process with a power spectrum with fractional power, for example the von Karman spectrum for atmospheric turbulence. The method uses digital filtering of a white noise process and it is based on the use of fractional derivatives. An algorithm to generate the process is presented.report 1988
- document
-
Moek, G. (author)The problem of estimating the probability of vertical overlap in possible future airway systems with a vertical separation standard of 1000 ft above Flight Level 290 is addressed. It forms part of an overall safety assessment of such potential systems. The problem is solved by developing a mathematical probability model of the vertical distance...report 1988
- document
-
Noback, R. (author)Measured time histories of atmospheric turbulence have been analysed. Distribution functions and exceedance curves of the turbulence and its derivative are presented. The load exceedance curves of various mathematical airplane models due to these turbulence patches have been calculated. Deviations of the properties of these patches from the...report 1988
- document
-
Moek, G. (author)Expressions are derived from which confidence regions for the parameters of three specific software reliability models can be computed. These expressions are based on the asymptotic probability distribution of the maximum likelihood estimator. Some numerical results of point estimates as well as confidence regions are given, based on simulated...report 1987
- document
-
Groothuizen, R.J.P. (author)In this report several methods for modeling uncertainty in expert systems are discussed. An overview is given of methods used in various existing expert systems and an attempt is made to put these methods into their proper perspective.report 1986
- document
-
Moek, G. (author)A probabilistic model is described for the lateral displacement of an aircraft after the occurrence of an engine failure during take-off. With the model, a lateral boundary is calculated, for any point of time after the engine failure, such that the probability of being within the (two sided) lateral boundary meets a specified value. Various...report 1985
- document
-
Noback, R. (author)A method is derived to generate consistent sets of design load conditions if aircraft design loads are determined using the Design Envelope criterion of the Power Spectral Density (P.S.D.)-method. The method is based on the use of the correlation coefficients between the various loads. Two sets of design load conditions have special properties...report 1985
- document
-
Noback, R. (author)In this report various methods to describe a landing gear with nonlinear properties and excitated by random runway unevenness during taxying have been investigated. The results of calculations have been compared to measured results from an analog computer simulation. The mean behaviour, standard deviations and power spectra, can be described...report 1984
- document
-
Heida, J.H. (author)This report describes the concept of reliability of nondestructive inspection (NDI) and reviews the different aspects involved. First, the probability of detection (POD) of flaws in flawed specimens is discussed. To provide a measure of confidence in an estimated POD, lower botind values of this probability at a given confidence level are...report 1984
- document
-
Noback, R. (author), Blaauboer, C. (author)Design loads for nonlinear aircraft, i.e. aircraft with gust alleviation system or yaw dampler, cannot be established with the Power Spectral Density method. The only method available is by means of computer simvilation. Methods to approximate load exceedance curves of nonlinear aircraft are proposed in this report. For the derivation of the...report 1980
- document
-
Noback, R. (author)In this report it is assumed that atmospheric turbulence appears in patches and that within the patches the turbulence can be described.as a modulated Gaussian process. The patch lengths have a certain probability density function. Load exceedance curves and design loads for various aircraft models for this turbulence model are compared with...report 1978
- document
-
Noback, R. (author)In this report a model for atmospheric turbulence is proposed. It is assumed that atmospheric turbulence appears in patches and that within the patches the turbulence can be described as a modulated Gaussian process. Statistical properties of this model and of atmospheric turbulence are compared. Using data from various sources a probability...report 1976
- document
-
Li, J. (author), Tian, Y. (author), Cassidy, M.J. (author)Natural soil is one of the most variable materials as a result of physical and chemical changes. The variation in soil properties significantly affects the failure mechanism and bearing capacity of a footing. This effect is further complicated by considering the spatial correlation of the soil properties. The purpose of this study is to...conference paper