314 research outputs found
Methodological aspects of the SAVE data set
No full textThis paper describes the general design of the SAVE survey: the design of the questionnaire, inter-viewer and interviewee motivation, and the sampling designs of the various subsamples collected in 2001 and 2003. It discusses the representativeness of the data, explains the construction of weights, and provides probit regressions to analyse potential selectivity problems. The paper finishes by discussing implications for the use of the SAVE data in various estimation procedures.
Flyover Noise Measurements of a Spiraling Noise Abatement Approach Procedure
No full textDLR is investigating alternative low-noise approach procedures. One such procedure involves approaching the airport at a considerably higher altitude compared with standard landing trajectories, followed by a spiraling descent (helix flight path) shortly before the runway threshold. In this way, high ground noise levels by approaching aircraft are dislocated away from the common approach path and concentrated in the area near the helix path, i. e. in direct vicinity of the airport. Ground noise levels along the entire flight path prior to the helix are significantly reduced. The effectiveness of this procedure, referred to as Helical Noise Abatement Procedure (HeNAP), has been quantified by means of computational simulation analyses. These analyses also focused on aspects such as increased fuel
burn and the occurrence of multiple noise events below the helix. In June 2009 a new DLR autopilot especially capable of tracking curved flight path trajectories was flight tested.
Three HeNAPs were included in the flight plan, as well as standard and steep landing approaches. In addition, dedicated fly-over noise measurements were organized, supported by RWTH Aachen University. Twelve ground microphones have been installed along the common approach path and the helical flight segment. Despite adverse wind conditions at the only available test day, the measured data confirm the predicted noise dislocation effects.
High noise levels have been limited to observer locations around the helix. DLR noise prediction methods have been compared with the experimental data. Predicted trends
and noise dislocation effects are in good agreement with the measurements whereas the absolute numerical values show discrepancies. The flight test was closely accompanied by
a R&D member of DFS to study the impact of spiraling procedures on ATM integration
and air traffic controller workload, e. g. increased interaction with the pilots. Obviously, a spiraling approach procedure would not be implemented into the existing air traffic scenario with its common approach paths and highly frequented airports. The operational and economic environment still need more detailed investigation. Helical approaches become
more feasible for implementation at small, low-frequented regional airports or during night hours to avoid possible noise related curfews
Towards a Quiet Short Take-Off and Landing Transportation System: Concept Evaluation and ATM Integration
No full textAircraft Noise Assessment Using Noise Points: Conception and Verification
No full textThe increase in global air traffic volumes has significant economic and ecological impacts. A key factor in this context is the development of the noise situation around airports. However, assessing the development of the noise situation at multiple airports simultaneously and in detail requires comprehensive calculations. Therefore, there is a strong need for a simple method to evaluate how the growth of air traffic affects the noise impact around airports, especially under considerations of different what-if scenarios. This can be achieved by assigning a noise-equivalent value to each aircraft that represents its noise impact. These noise points indicate how many movements of a reference aircraft would be required to produce approximately the same noise impact as one movement of the aircraft under consideration. The concept allows for an easy and quick assessment of aircraft noise by summing such noise points, because, as shown in this study, the noise point sum can directly be related to a change in noise levels and contour area. This article presents a promising method for determining noise points and applies it to aircraft groups from a recently proposed database of the German aircraft noise calculation method AzB. The noise point concept is verified at various airports, demonstrating its effectiveness in representing noise situations and developments. The differences of analyzed contour areas obtained via noise calculations and via the noise point concept remain below 3.6% over a generic 30-year forecast
Aircraft Noise
No full textThis reprint is about aircraft noise. Multidisciplinary topics are covered. One focus is supersonic transport aircraft and their noise generation during approach and take-off. The articles within this study present recent and ongoing research activities from research entities and universities from around the world. This book is beneficial for engineers and researchers that are working the field of aircraft noise
Aircraft Noise Mitigation - Concepts, Assessment, and Implementation
No full textDLR has initiated a special issue in the area of aircraft noise mitigation. Contributions aim at novel concepts, the assessment, and the implementation of such mitigation measures.
This Special Issue aims to attract contributions on the mitigation of exterior aircraft noise—specifically covering the following three subtopics: (1) concepts, (2) assessment, and (3) implementation. Contributions can focus on conventional or novel transport aircraft, conceptual supersonic transport aircraft, or advanced air mobility vehicles
Validation strategies for comprehensive aircraft noise prediction methods
No full textThis contribution deals with validation and verification issues in aircraft noise prediction. We use two different comprehensive simulation software: PANAM, developed at DLR and FLIGHT, developed at the University of Manchester. The comparison is done on the basis of extensive flight data taken on an Airbus A319-100 operated by Lufthansa. The flight recorder data have been synchronized with noise measurements on the ground, at 25 different observer locations. This paper aims to contribute to the establishment of rational validation standards, as well as realistic accuracy margins on integral noise metrics. The computer codes are briefly described. Results are shown for a variety of microphone positions, located sideways and directly along selected departure and approach flight ground tracks. © 2012 by A. Filippone, L. Bertsch & M.Pott-Pollenske
Lothar Bickel : (8. Mai 1902 - 23. April 1951).
No full textThe author describes his friendship with Lothar "Elieser" Bickel in the Zionist youth group "Hashomer Hazair", where he met him in 1919 in Czernowitz, Bukowina. Discussion of Jewish-national and social problems and studies of Hebrew. Elieser's growing interest in philosophical and socialist themes. His brother Schlomoh Bickel was a leader of the worker's movement Poale Zion. Influence of the ethic seminary by Dr. Kettner and criticism on Zionist ideals. Elieser Bickel became acquainted with the philosopher Constantin Brunner and grew to become one of his most talented students. In 1922 Elieser enrolled at the Medical School in Bucharest, where he experienced virulent anti-Semitism at the university. Disintegration of Dr. Kettner's seminary in Czernowitz. Circle around Elieser Bickel who promoted the growing importance of Brunner's philosophy. In 1926 Elieser graduated. After completing his military service he decided to move to Berlin in 1927. Czernowitz philosophy circle in Berlin and friendship with Constantin Brunner. Lectures and studies of philosophy. Work as a physician in Berlin and Prenzlau. In 1931 journey to Spain. After Hitler's takeover in 1933 he moved back to Bucharest, where Lothar Bickel became one of the most renowned gynecologists. He continued his philosophic interests and specialized in the ethic of Spinoza and Kant. Death of Constantin Brunner in 1937. Acquaintance with Maedi Moscovici. They married in 1939 in Czernowitz. Military service and growing danger of approaching Germans. Precarious situation of the Jewish population. Armistice and continuation of his philosophic work. In 1950 Lothar Bickel emigrated to Canada. He died in Toronto in 1951.Lothar (Elieser) Bickel was born 1902 in Kisselew, a village in Northern Bukowina. He grew up in an orthodox house. His father was the owner of a small pub. Elieser was sent to his pious grandparents in Kolomea, where he received a pronounced Jewish education. He was sent to the high school (Gymnasium) and excelled as a student. After World War I and the collapse of the Austro-Hungarian Monarchy Kisselow became part of Romania. In 1918 Elieser continued his schooling at the Jewish Gymnasium in Czernowitz, where he was part of the Zionist youth group Hashomer Hazair. Elieser became a radical assimilationist under the influence of the philosopher Constantin Brunner. He studied medicine in Bucharest and settled as a physician in Berlin and Prenzlau. In 1933 Lothar Bickel returned to Bucharest. He emigrated to Canada in 1950, where he died one year later. Bickel wrote four philosophical books, which were published posthumously.Ball, SchlomohBrunner, LotteKasch, MagdalenaSemmel, KarlSonntag, LeoSternschuss, Mosche (Sterian)Stier, GabrielBucharestBerlinKolomeaAssimilationEducation, Jewish, 1871-1918Education, higher, 1918-1933FriendshipLiteratureMedicineMilitary servicePoale ZionYouth grou
Stanley's character polynomials and coloured factorisations in the symmetric group
No full textIn Stanley [R.P. Stanley, Irreducible symmetric group characters of rectangular shape, Sém. Lothar. Combin. 50 (2003) B50d, 11 p.] the author introduces polynomials which help evaluate symmetric group characters and conjectures that the coefficients of the polynomials are positive. In [R.P. Stanley, A conjectured combinatorial interpretation of the normalised irreducible character values of the symmetric group, math.CO/0606467, 2006] the same author gives a conjectured combinatorial interpretation for the coefficients of the polynomials. Here, we prove the conjecture for the terms of highest degree
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