Sökning: "aircraft noise"
Visar resultat 1 - 5 av 51 avhandlingar innehållade orden aircraft noise.
Sammanfattning : The thesis consists of five papers which are divided into three main parts. Parts A and B deal with active noise control in a propeller aircraft application, whereas Part C deals with active noise control in a helicopter application. LÄS MER
Sammanfattning : A few aspects of aircraft noise were evaluated. These were (i) methods of subjective evaluations, (ii) effects of equalization and (iii) the effects of cognitive aspects.In the first paper, sorting algorithms were used instead of conventional paired comparison method in order to reduce the number of pairs in the evaluation of subjective judgments. LÄS MER
Sammanfattning : A deterministic approach based on a modal expansion and modal receptance method has been developed to evaluate the airborne sound insulation of aircraft panels with stringer and ring frame attachments. Furthermore, this method was extended to predict the noise radiation of stiffening panel subjected to TBL excitation. LÄS MER
Sammanfattning : Paper 1 investigates how birth order and having siblings affect positional concerns in terms of success at work and of income. We find that only-children are the most positional, but that number of siblings increases the concern for their position among those who grew up together with siblings. LÄS MER
Sammanfattning : In the last decade acoustic noise has become more and more regarded as a problem. In cars, boats, trains and aircraft, low-frequency noise reduces comfort. Lightweight materials and more powerful engines are used in high-speed vehicles, resulting in a general increase in interior noise levels. LÄS MER