Development of a sensor for high-quality two-phase flow

The monitoring of the quality of the two-phase mixture at various locations in the system is a valuable, possibly indispensable, part of the control system needed to properly operate a two-phase heat transport system for large spacecraft. Based on a trade-off of various quality monitoring concepts, NLR started to develop a dedicated quality...

Approximate confidence regions for the parameters of three software reliability models

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...

Image quality criteria with emphasis on criteria for remote sensing imagery

Image quality plays an important role on the various levels of image processing. However, until now it lacks a survey of methods for the evaluation of image quality. With a grant of the Netherlands Agency for Aerospace Programs (NIVR) a study was performed with respect to the quantification of image quality. Some results of this study are...

Reliability aspects of software for digital avionics

Modern commercial transport aircraft contain digital avionics systems for more and more safety critical functions. The reliability and safety of those new systems depend on the hardware reliability and on the reliability of the embedded software. In this report, an overview is given of available methods and techniques to develop reliable...

A method for applying linear optimal control theory to the design of a regulator for a flexible- aircraft

This report deals with determining a hypothetic control system which provides improved rigid body and structural mode damping of a flexible aircraft in order to improve the riding qualities and to minimize the wing bending moment during flights in turbulence. The equations of motion used in the computations are related to a high' performance...

Cost estimation and management control of software development in scientific/technical projects

Cost estimation of software development.and the monitoring and control of factors which affect the development cost is difficult due to the lack of uniformity in the development approach, to the lack of a standard terminology and due to the limited and difficult to access cost data bases. This report presents a cost estimation approach, together...

De toepassing van schade-onderzoek in de luchtvaart

Following an introduction about the methods of failure smalysis the present paper illustrates by meaJis of actual case histories the role of service failure analysis in defining new inspection procedures and the adapting of existing ones. It appears that in some cases this leads to a different design or choice of material. The examples are all...

Transducer selection

The transducer selection process as applied to the F29 digital data-acquisition system is discussed in detail. The selection procedure consists of interviews of the users of the system, specification of the transducer part of the data-acquisition system, transducer selection from manufacturer data, evaluation tests, integration into the data...