ATEFA - A first German approach on UAM community noise and air-taxi certification

2021 ◽  
Vol 263 (6) ◽  
pp. 746-751
Author(s):  
Michael Bauer ◽  
Daniel Redmann ◽  
Lis Weilandt
Keyword(s):  
Urban Environment ◽  
Low Noise ◽  
Broadband Noise ◽  
Urban Air ◽  
Southern Germany ◽  
Large Cities ◽  
Funded Research ◽  
Community Noise ◽  
New Type ◽  
Funded Research Project

Urban air mobility (UAM) includes larger air taxis, driven by multiple distributed propellers or fans, installed in a fixed configuration or as tilted wings/engines. These novel electric air vehicles will always generate tonal and broadband noise, in some cases with components from a specific installation situation. In any case, noise will propagate to the ground, into high populated areas of large cities or into their urban environment, individually depending on the operational situation of air taxi use. Some of the populated areas, where no significant noise from air traffic has been observed so far, will be exposed to this new type of aircraft noise. ATEFA, as the first German national funded research project on UAM community noise, aims to provide first answers. Three selected air taxi concepts, strongly differing acoustically from each other, will be technically described and their noise emissions will be modeled and predicted. Air taxi operations will be simulated by generic traffic scenarios in a selected area of southern Germany, and community noise near vertiports, but also "en-route" along the flight paths, will be computed. Beside this, noise certification aspects will be assessed regarding metrics and procedures and compared to a light low-noise helicopter as reference aircraft.

scholarly journals Variable-Temperature Noise Characterization of N-MOSFETs Using an In-Situ Broadband Amplifier

2021 ◽  
Author(s):  
Kenji Ohmori ◽  
Shuhei Amakawa
Keyword(s):  
Shot Noise ◽  
Printed Circuit Board ◽  
Noise Figure ◽  
Variable Temperature ◽  
Low Noise ◽  
Broadband Noise ◽  
Circuit Board ◽  
Low Frequencies ◽  
Cryogenic Chamber

Characterization of broadband noise of MOSFETs from room temperature down to 120 K in fine temperature steps is presented. A MOSFET is mounted on a reusable printed circuit board vehicle with a built-in low-noise amplifier, and the vehicle is loaded into a cryogenic chamber. The vehicle allows noise measurement in the frequency range from 50 kHz to 100 MHz. At low frequencies, it enables extraction of activation energies associated with electron trapping sites. At high frequencies, as has been suggested by noise figure measurements, the white noise of MOSFETs is shown to be dominated by the shot noise, which has much weaker temperature dependence than the thermal noise. The shot noise will be a problematic noise source in broadband RF CMOS circuits operating at cryogenic temperatures.<div><br></div>

scholarly journals ELSA – training the next generation of space astrometrists

2007 ◽  
Vol 3 (S248) ◽  
pp. 529-530
Author(s):  
L. Lindegren ◽  
A. Bijaoui ◽  
A. G. A. Brown ◽  
R. Drimmel ◽  
L. Eyer ◽  
...  
Keyword(s):  
Numerical Analysis ◽  
Data Processing ◽  
Next Generation ◽  
Research Project ◽  
Processing Methods ◽  
Funded Research ◽  
Space Astrometry ◽  
Young Researchers ◽  
Funded Research Project ◽  
Data Processing Methods

AbstractELSA (European Leadership in Space Astrometry) is an EU-funded research project 2006–2010, contributing to the scientific preparations for the Gaia mission while training young researchers in space astrometry and related subjects. Nine postgraduate (PhD) students and five postdocs have been recruited to the network. Their research focuses on the principles of global astrometric, photometric, and spectroscopic measurements from space, instrument modelling and calibration, and numerical analysis tools and data processing methods relevant for Gaia.

Community noise from urban air mobility (UAM) and its control by traffic management

2021 ◽  
Vol 263 (6) ◽  
pp. 187-193
Author(s):  
Michael Bauer
Keyword(s):  
Traffic Management ◽  
Electric Propulsion ◽  
Traffic Noise ◽  
Environmentally Friendly ◽  
Urban Air ◽  
Acoustic Characteristics ◽  
Operational Conditions ◽  
Community Noise ◽  
Open Questions ◽  
Noise Metrics

The awareness about UAM is amplified by steadily growing numbers of air taxi concepts being announced. In general environmentally friendly by electric propulsion, community noise and en-route noise are still prominent open questions. Several studies for larger UAM aircraft, describing the acoustic characteristics of a variety of potential air taxi concepts, have been performed by the author. Due to the abovementioned multitude of different vehicle concepts and their multiple operational conditions, each of them shows individual sound characteristics. Therefore, further investigations of noise created by air taxi fleets appear to be crucial. Understanding of community noise around vertiports and along air taxi routes will strongly depend on those fleets. In this paper, acoustically different air taxi systems are composing different sets of air taxi fleets, used for air traffic noise simulations. The simulations start with baseline scenarios of equally represented taxi systems on fixed flight paths with several flight levels in a certain air lane. The final fleets are consisting of random air taxi composition with randomly populated flight paths. The results, based on common noise metrics and changes in the number of affected residents, could provide a first indication how to reduce community noise by future UAM traffic management.

A Participatory Design Approach with Visually Impaired People for the Design of an Art Exhibition

2017 ◽  
Vol 9 (4) ◽  
pp. 43-57
Author(s):  
Karine Lan HingTing ◽  
Ines Di Loreto
Keyword(s):  
Visual Art ◽  
Participatory Design ◽  
Visually Impaired ◽  
Social Inclusion ◽  
Publicly Funded ◽  
Art Exhibition ◽  
Funded Research ◽  
Visually Impaired People ◽  
Impaired People ◽  
Funded Research Project

This article describes the participatory design (PD) approach adopted in systematically involving visually impaired people in the design of an art exhibition adapted to their needs. This exhibition will be the outcome of a publicly-funded research project aimed at making visual art accessible to everyone: specifically (but not exclusively) to visually impaired people, in an objective of social inclusion. This article presents the research done to elicit, capture, and analyse the needs of visually impaired people who are the active actors of this research. The aim of the article is to trigger discussion about both the necessity and difficulty of elaborating relevant techniques in this empirical and open-ended approach, and what is meant by participation in this particular setting.

From Apple to Orange: Narratives of Small City Migration and Settlement among the Urban Middle Class

2018 ◽  
Vol 62 (3) ◽  
pp. 402-425 ◽  
Author(s):  
Richard E. Ocejo
Keyword(s):  
New York ◽  
Qualitative Research ◽  
New York City ◽  
Middle Class ◽  
Urban Environment ◽  
York City ◽  
Small City ◽  
Small Cities ◽  
Large Cities ◽  
The City

As large cities become unaffordable, some people in the urban middle class are moving to small cities but risk replicating gentrification and its harms. Based on a qualitative research project on Newburgh, a small city north of New York City, this paper examines the narratives that middle-class urbanites construct to make sense of this migration, their new urban environment, and their place within it. These narratives describe their decision to move (migration) and their everyday lives in the city (settlement). Most importantly, their narratives are shaped by their social positions as both displaced residents and gentrifiers and as both consumers and producers of space. But despite being self-aware gentrifiers, their settlement narratives lack reflections on their own displacement from New York City, and instead emphasize how they try to mitigate gentrification’s harms. The paper concludes with a discussion of what makes gentrifiers in small cities distinct from those in large ones.

Aeroacoustic Study on a Simplified Nose Landing Gear

2012 ◽  
Vol 184-185 ◽  
pp. 18-23 ◽  
Author(s):  
Shuang Li Long ◽  
Hong Nie ◽  
Xin Xu
Keyword(s):  
Simulation Analysis ◽  
Sound Field ◽  
Low Noise ◽  
Landing Gear ◽  
Broadband Noise ◽  
Detached Eddy Simulation ◽  
Gear Design ◽  
Aeroacoustic Noise ◽  
Eddy Simulation ◽  
Landing Gear Noise

Simulation analysis and experiment research are performed on the aeroacoustic noise of a landing gear component in this paper. Detached Eddy Simulation (DES) is used to produce the flow field of the model. The Ffowcs-Williams/Hawkings (FW-H) equation is used to calculate the acoustic field. The sound field radiated from the model is measured in the acoustic wind tunnel. A comparison shows that the simulation results agree well with the experiment results under the acoustic far field condition. The results show that the noise radiated from the model is broadband noise. The directivity of the noise source is like a type of dipole. The wheel is the largest contributor and the strut is the least contributor to the landing gear noise. The results can provide some reference for low noise landing gear design.

scholarly journals The Reframing of Methodology: Revisiting a PhD Study

2014 ◽  
Vol 19 (4) ◽  
pp. 39-47 ◽  
Author(s):  
Sarah Dubberley
Keyword(s):  
Qualitative Research ◽  
Qualitative Study ◽  
Research Design ◽  
Study Design ◽  
Quantitative Method ◽  
Critical Realism ◽  
Funded Research ◽  
Alternative Proposal ◽  
Methodological Position ◽  
Funded Research Project

The paper draws on a PhD study to explore some methodological dilemmas associated with the execution of qualitative research when framed within positivist study design. The PhD was linked to an externally funded research project which evaluated the implementation of a custody-based intervention in the secure estate. While the PhD was conceived as a qualitative study, informed by interpretivist methodology and associated epistemology, the wider funded study was informed by positivist tradition and used a quantitative method. This led to dilemmas of both practical and methodological nature. The author revisits her study's methodological position to review issues raised by the research design and suggests an alternative proposal informed methodologically by critical realism which may better serve the study's interests. In doing so, the paper suggests how revisiting previous research may assist us in gaining methodological understanding and allow us to reframe our future endeavours to more useful end.

Kinematics Analysis of the New Type of Offset Radial Piston Motor

2014 ◽  
Vol 889-890 ◽  
pp. 463-466
Author(s):  
Sheng Mei Luo ◽  
Wei Liu ◽  
Fu Fang Luo ◽  
Wei Wei Yu ◽  
Zhi Hong Ma
Keyword(s):  
Hydraulic System ◽  
Pure Water ◽  
Low Noise ◽  
Hydraulic Motor ◽  
General Motor ◽  
Low Speed ◽  
Structural Principle ◽  
New Type ◽  
Type Motor ◽  
Startup Performance

This paper introduces the structural principle of a new offset radial type motor. Through analyzing the kinematic characteristics of the motor piston theory, the result shows that the motor has characteristics of good startup performance at low speed, good sliding performance with sliding boots, smooth operation, low noise and so on, so the performance is superior to the general motor of low speed and high torque. Besides, comparing with other types of hydraulic motor, its lifetime increases and it is also easier to produce and repair. Moreover, beside the use of common hydraulic system, it can also be used in pure water hydraulic system under certain conditions.

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