Route towards power MOSFET large thin die mechanical robustness: Masters thesis report

Today’s cars are undergoing the greatest transformation the industry has seen. Power MOSFETs play a crucial role in making electronics more energy efficient by driving down switching losses and Rdson using a combination of next-generation trench technology and ultra-thin dies. Power MOSFET dies are becoming larger ( > 5 X 5 mm ) and thinner (...

Wave overtopping processes for very mild sloping and shallow foreshores

A sea-dike system is of importance for the protection of the hinterland. However, the effect of very gentle and shallow sloping foreshores (in the order up to 1 in 1000) on wave overtopping processes has not yet been quantified enough and, thus, so far is not well understood. This dissertation seeks an answer to the question of whether the...

Remote sensing-based prediction of forest fire characteristics

Forest fires are a major ecosystem disturbance at global scale, put pressure on agencies in charge of citizens and infrastructure security and cause unvaluable human losses. Fires are controlled by multiple static and dynamic drivers related to topography, land cover, climate, weather, and anthropic activity. Among these, weather is an active...

Distribution of individual wave overtopping volumes at rubble mound seawalls

For a safe design of a rubble mound seawall, overtopping characteristics such as the mean overtopping discharge (q) and the maximum individual overtopping volume (V_max) should be limited. Unlike q, the estimation of V_max is more complex and requires a wave-by-wave analysis of overtopping as well as a statistical analysis...

Data Analytics for Grid Resilience with Early Failures and Wear-out Failures

The here reported work is part of a project on supporting grid resilience by asset management techniques. The present work focuses on support of decision-making after a few failures occurred that may be the start of many more. Methods are reviewed and new algorithms developed where the present IEEE/IEC standard does not provide. Two cases of...

Predictive maintenance of systems subject to hard failure based on proportional hazards model

The remaining useful lifetime (RUL) estimated from the in-situ degradation data has shown to be useful for online predictive maintenance. In the literature, the RUL is often estimated by assuming a soft-failure threshold for the degradation data. In practice, however, systems may not be subject to the degradation-induced soft failures....

Estimation of the incubation time distribution for COVID-19

We consider smooth nonparametric estimation of the incubation time distribution of COVID-19, in connection with the investigation of researchers from the National Institute for Public Health and the Environment (Dutch: RIVM) of 88 travelers from Wuhan: Backer et al. (2020). The advantages of the smooth nonparametric approach with respect to...

Prediction of Strength for Inhomogeneous: Defective Glass Elements Based on the Sequential Partitioning of the Data and Weibull Statistical Distribution

An analytical approach based on the on the sequential partitioning of the data and Weibull Statistical Distribution for inhomogeneous - defective materials is proposed. It allows assessing the guaranteed strength of glass structures for the low probability of fracture with a higher degree of reliability. Parameters of equations for the piecewise...

Optimal siting and sizing of wind farms

In this paper, we propose a novel technique to determine the optimal placement of wind farms, thereby taking into account wind characteristics and electrical grid constraints. We model the long-term variability of wind speed using a Weibull distribution according to wind direction intervals, and formulate the metrics that capture wind speed...

Multigrid method for nonlinear poroelasticity equations

In this study, a nonlinear multigrid method is applied for solving the system of incompressible poroelasticity equations considering nonlinear hydraulic conductivity. For the unsteady problem, an additional artificial term is utilized to stabilize the solutions when the equations are discretized on collocated grids. We employ two nonlinear...

Life-cycle assessment of high-voltage assets using statistical tool

Nowadays, utilities are confronted with assets reaching or even exceeding their designed life. This in turn, implies the occurrence of upcoming replacements to assure reliable network operation. In this thesis, the application of statistical tools for life-time and residual life assessment of high-voltage assets installed in a power network is...

High Voltage Asset Performance Modeling

Many of the assets managed by TenneT TSO have been installed in the sixties and seventies of the previous century. Consequently, 50% of their assets will reach their designed lifetime within ten years. Due to financial and technical restrictions not all the asset can be replaced based on their age. Hence, TenneT TSO developed a Health index tool...

Drying and Rehydration of Calcium Alginate Gels

In this paper, we study the rehydration properties of air-dried calcium alginate gel beads. Rehydration is shown to depend on alginate source (i.e. mannuronic to guluronic acid ratio) and the salt concentration in the rehydration medium. Rehydration curves are described adequately by the empirical Weibull equation. Wide-angle X-ray diffraction...

Example of the determination of a design storm

Example for the the dataprocessing of wave data in such a way that design values for coastal structures can be determined

Size effect of concrete and sandstone

A series of uniaxial tension experiments has been conducted to investigate the size effect on strength and fracture energy of concrete and sandstone. The experiments were carried on specimens of six different sizes in a scale range of 1:32. Depending on the material and the curing conditions a stronger or weaker size effect on the nominal...

Tensile fracture of notched composite laminates

This report describes the determination of empirical parameters for a fracture model which can be used to predict the uniaxial tensile strength of composite laminates containing notches of various sizes. The parameters required are the characteristic dimension and the unnotched tensile strength of the subject laminate. A data base including...

Shallow foreshore wave height statistics

Wave height distributions on shallow foreshores deviate from those in deep water due to the effects of the restricted depth-to-height ratio and of wave breaking. Laboratory data of wave heights on shallow foreshores of different slopes have been analysed to determine these effects and to derive generalised empirical parameterisation. A model...

A compound Weibull model for the description of surface wind velocity distributions

Statistical description of wind speed near de surface, basis of tlhe Rijkoort-model for wind prediction.