Evaluation of a method to extract performance data from dynamic maneuvers for a jet transport aircraft

A very accurate measurement system and a data reduction method have been developed to extract performance data from a single dynamic maneuver, in order to reduce the large amoimt of flight hours required for the determination of these data by means of measurements in steady flight. In order to evaluate the applicability of this method to a modem...

Gyro noise measurement and analysis

Noise measurements were performed on two identical space qualified gyroscopes of the floated rate integrating type (Perranti Type I25) in an analog rehalance loop configuration of selectable loop bandwidth, running under space representative conditions. The noise frequency range of interest was O.OO5 Hz to 50 Hz. The noise results were processed...

Parameter identification results of tests in non-steady symmetric flight with the Hawker Hunter Mk VII

This report presents the parameter identification results derived from data recorded during non-steady symmetric flight test manoeuvres with the Hawker Hunter Mk VII laboratory aircraft. This flight test program was executed in co-operation with the Department of Aerospace Engineering of the Delft University of Technology. The reproducibility of...

Image data reduction with splines and segmentation with emphasis on earth observation

This report describes the results of a feasibility study on image data compression using spline approximation and image segmentation, with emphasis on earth observation applications. The main subjects dealt with, are: the data compression method, implementation aspects, the test software and test results. It appears that a reduction factor of 5...

Data compression in computational fluid dynamics

Computations in numerical fluid dynamics create large sets of data. Transmission of these datasets requires a high speed communication link or, alternatively, the use of data compression techniques. This report describes the results of a study to the applicability of data compression techniques. An algorithm is designed that yields favourable...

CADISS: a multi-processor system for image compression/decompression on board scientific satellites

Project CADISS has produced an elegant breadboard of a system for compression (and -if required- decompression) of signals generated by imaging sensors on-board scientific satellites. The performance, specifications and physical characteristics of CADISS are the result of trade-offs on function (algorithms), technology, through-put speed and...

On the feasibility of applying robot vision to proximity extraction based on one camera in space

Existing robot vision algorithms are evaluated for application in space for proximity extraction using one camera. Lighting conditions and image formation differ from earth conditions which have implications. An algorithm is derived which is based on the use of run coding, tracking and a least mean error method. Problems concerning hardware...

Boundary-layer effects in unsteady pressure measurements with tubes

An experimental investigation revealed that the d5mamic response of a given pressure tube depends not only on the mean local pressure and the frequency, but also on the pressure amplitude and the boundary-layer at the tube entrance. By analyzing the flow at the entrance of the tube, the parameters are determined, which possibly play a role in...

A study on methods to compare measured and calculated modal data

Fokker Space and Systems and the National Aerospace Laboratory NLR performed a study to integrate more systematically the experimental and analytical analysis of the dynamic behaviour of structures. The study focused on the correlation of experimental and analytical data, matrix and parameter updating methods. In this paper an overview will be...

Simplified 3D city models from LiDAR

Aerial laser scan data is widely used to produce 2½D digital elevation models automatically. However, creating full 3D city models from this data is a complex task. A simplified 3D model, like a 2½D model with vertical walls will be easier to produce automatically, especially when the model is not produced to look nice, but just to give...

Critical Parameters in Mode I Interlaminar Fracture Toughness Testing of Thermoplastic Composite Materials

The goal of the thesis (executed for Fokker Aerostructures) was to further the understanding of critical parameters in the DCB test method for thermoplastic composites. The influence of fiber bridging, specimen thickness, insert film thickness, crack length and crack opening rate are investigated by means of experimental DCB tests for...

A data reduction strategy and its application on scan and backscatter detection using rule-based classifiers

In the last few years, the telecommunications scenario has experienced an increase in the volume of information generated, as well as in the execution of malicious activities. In order to complement Intrusion Detection Systems (IDSs), data mining techniques have begun to play a fundamental role in data analysis. On the other hand, the...

An assessment of the information lost when applying data reduction techniques to dynamic plantar pressure measurements

Data reduction techniques are commonly applied to dynamic plantar pressure measurements, often prior to the measurement's analysis. In performing these data reductions, information is discarded from the measurement before it can be evaluated, leading to unkonwn consequences. In this study, we aim to provide the first assessment of what impact...

Data Reduction Techniques of Coral Reef Morphology and Hydrodynamics for use in Wave Runup Prediction

Many tropical, coral reef-lined coasts, are low-lying with elevations less than five meters above mean sea level. Climate-change-driven sea level rise, coral reef decay and changes in (storm) wave climate will lead to greater chance and impacts of wave-driven flooding, posing a heavy threat to these coastal communities. Early warning systems ...

Comparative Analysis of Techniques for Data Minimization for Recommender System algorithms

Recommender systems (RS) often use a large amount of data for a marginal gain in performance. This thesis investigates the data minimization in Recommender Systems, which is not well studied in the literature. This thesis extends the data minimization principles advocated in GDPR and studies its effects on recommender systems. Minimizing data...

A multi-measure feature selection algorithm for efficacious intrusion detection

Every day the number of devices interacting through telecommunications networks grows resulting into an increase in the volume of data and information generated. At the same time, a growing number of information security incidents is being observed including the occurrence of unauthorized accesses, also named intrusions. As a consequence of...

A fast instance reduction algorithm for intrusion detection scenarios

We live in a world that is being driven by data. This leads to challenges of extracting and analyzing knowledge from large volumes of data. An example of such a challenge is intrusion detection. Intrusion detection data sets are characterized by huge volumes, which affects the learning of the classifier. So there is a need to reduce the size...

Mesh Deformation Using Radial Basis Function Interpolation for Numerical Optimisation of Internal Flow Applications

Developments in computational capabilities and the always increasing demand for higher performance of internal flow applications has meant that Computational Fluid Dynamics (CFD) has become an essential tool within the design process. A key point of interest is to couple the fluid solver with numerical optimisation techniques in order to obtain...