About

David Landes is the Emerti-Coolidge Professor of History and Professor of Economics at Harvard University. He is associated with the Department of Economics and holds a distinguished position within the university's faculty. His role involves teaching, research, and contributing to the academic community in both history and economics. His work and expertise are recognized within Harvard's academic environment, and he is involved in various programs and initiatives related to economics and history.

Research topics

• Computer Science
• Artificial Intelligence
• Social Science
• Physics
• Political Science
• Sociology
• Automotive engineering
• Law
• Engineering
• Acoustics
• Philosophy
• Media studies
• Epistemology

Selected publications

• A Novel Calculation Method to Quantify the Torque Dependency of the Masking Threshold of Tonal Powertrain Noise in Electric Vehicles

  Applied Sciences · 2024-12-20

  articleOpen access

  Tonal powertrain noise can have a strong negative impact on passengers’ quality and comfort perception in the interior of electric vehicles. Therefore, in the vehicle development process, the assessment of the perceptibility of tonal powertrain noise is essential. As wind and tire noise can possibly mask tonal noises, engineers use modern masking models to determine the masking threshold of tonal powertrain noise from vehicle interior measurements. In the presently used method, the masking threshold is mostly generated with torque-free deceleration measurements. However, the influence of torque on masking tire noise must be considered. As this requires time-consuming and costly road measurements, an extension of the method is being developed, which will also enable the use of roller dynamometer measurements for the assessment. For the extension of the method, however, the influence of the torque must also be considered. This paper presents a novel calculation method that quantifies the influence of torque on the masking threshold and converts masking thresholds from an arbitrary torque level to another. By identifying the frequency and speed range that is mainly affected by the torque-dependent tire noise, a regression model with respect to the tractive force on the tires can be used to calculate a torque-dependent correction factor. The developed method can significantly improve the validity of masking thresholds and quantitatively, the method generalizes well across different vehicle segments. The error can be reduced to below 2 dB above 2000 rpm and to below 1 dB above 4000 rpm. By using this method, more valid target level settings for tonal powertrain noise can be derived.

  PublisherOA PDFDOI

• Experimental Determination of the Masking Threshold for Tonal Powertrain Noise in Electric Vehicles

  Acoustics · 2023 · 6 citations

  • Computer Science
  • Acoustics
  • Computer Science

  Tonal powertrain noise can have a strong negative impact on vehicle sound quality. Therefore, an assessment of the perceptibility of tonal noise with respect to masking noise is essential for the vehicle development process. In electric vehicles, due to the missing masking by the combustion engine, new methods are required for this purpose. In this study, listening tests were conducted to determine the masking threshold in the electric vehicle interior for various driving speeds (30 km/h, 60 km/h, and 90 km/h) with an Adaptive-Forced-Choice method. The novelty of this study is that it used vehicle interior noise as a masker, compared to broadband or narrowband white and pink noises. It could be shown that the masking threshold in electric vehicles strongly depends on the driving speed, and the investigated interior noise mainly affects frequencies up to 6400 Hz in this speed range. For frequencies greater than 6400 Hz, the masking noise has no significant effect on perceptibility of tonal noise in the investigated vehicle, and only the subjects’ individual absolute threshold of hearing is relevant. Additionally, a strong variation in the masking threshold between the subjects was found for high frequencies. With these results, methods that estimate masking thresholds in electric vehicles can be improved. Furthermore, threshold targets can be adjusted for different customer groups.

  PublisherOA PDFDOI

• 'Die Welt als Uhr'; or the Clockwork Universe

  Open MIND · 2023-01-01

  article1st authorCorresponding

  Kunstchronik. Monatsschrift für Kunstwissenschaft, Bd. 33 Nr. 11 (1980): Kunstchronik. Monatsschrift für Kunstwissenschaft, Museumswesen und Denkmalpflege

• Torque dependent behavior of the vehicle background noise and its influence on masking thresholds in electric vehicles

  NOISE-CON proceedings · 2023-11-30 · 1 citations

  article

  The quality and comfort perception in vehicles is strongly influenced by the overall sound quality of the vehicle. Besides aerodynamic and tire noise, tonal powertrain noise plays an important role and can have a strong negative impact on sound quality. An assessment of the perceptibility of tonal noise with respect to masking noise is therefore essential for the vehicle development process. Due to the absence of masking by the internal combustion engine in electric vehicles and the wider frequency range of the powertrain noise, new methods are required for this purpose. In order to evaluate state of the art masking models and a newly developed method regarding the audibility of tonal components, masking thresholds for tonal noise in the vehicle interior are experimentally determined in listening tests. A currently developed extension of the method will also allow roller dynamometer measurements to be used for the evaluation. Currently, the masking signals are mostly generated with torqueless coast down measurements to consider the worst-case scenario. However, a torque dependency has to be taken into consideration. In this paper the torque dependency of the masking noise and the resulting influence on masking threshold is shown for road and roller dynamometer measurements.

  PublisherDOI

• Some Thoughts on the Nature of Economic Imperialism

  2022-12-22 · 2 citations

  book-chapter1st authorCorresponding

  The economic interpretation of imperialism has many faces. It goes back almost a hundred years and derives from a number of separate sources. The foregoing analysis of the complexity of imperialism, with its stress on what we may call countervailing forces—avoidance of or opposition to territorial expansion; conflicts between business ambitions, state policy and personnel; subordination of economic interests to diplomatic considerations—suggests a question: in view of all this tugging and hauling, how does one account for the remorseless if spasmodic advance of imperialism over the course of the century? Surely all these contradictory tendencies and hesitations are only the surface detail that characterizes any broad historical movement. Surely, once one cuts away the brush one finds firm ground—the ground of economic motivation that changes its form of expression but not its meaning. Koebner distinguished three streams—the Marxian, Fabian, and American—and each of these is a blend of varied currents.

  PublisherDOI

• Optimization of the Powertrain Noise for the Electric Vehicle Mercedes-Benz EQC

  ATZ worldwide · 2020 · 6 citations

  • Computer Science
  • Automotive engineering
  • Computer Science
  PublisherDOI

• Marshall McLuhan’s theory of attention: How to become a media psychonaut

  Explorations in Media Ecology · 2020 · 4 citations

  1st authorCorresponding
  • Sociology
  • Sociology
  • Epistemology

  In light of surging cross-disciplinary interest in rethinking the conceptions of attention and attention economy, this article conducts an archaeology of Marshall McLuhan’s concepts in order to construct a theory of attention implicit in his media paradigm. McLuhan’s most attentional concepts are explained (such as figure/ground and cliché/archetype) and synthesized into an integrated account of his idea of attention, which I call ‘eco-formed attention’. It contrasts with reigning individualist and collectivist theories of attention by being constitutive, modal, dialectical, environmental and negative-inclusive. I argue that McLuhan’s fundamental problematic of attention – concepts mismatching percepts – is solved by using eco-formed attention to become a ‘media psychonaut’. Four procedures are explained to illustrate psychonautic interventions in eco-formed attention. This project is useful for media-ecological analyses, creative re-engagement with media, and reforming attention within future technological changes. The article concludes by linking to several agendas in media ecology and across the humanities.

  PublisherDOI

• Optimierung des Antriebsgeräuschs für das Elektrofahrzeug Mercedes-Benz EQC

  ATZ - Automobiltechnische Zeitschrift · 2020-02-28

  article
  PublisherDOI

• The Fable of the Dead Horse; or, the Industrial Revolution Revisited

  2018-02-06 · 12 citations

  book-chapter1st authorCorresponding

  Arnold Toynbee saw the Industrial Revolution as sudden, rapid, and drastically unfavorable in its reorganization of labor and its larger social effects. T. S. Ashton's ode to industrialization announced a period of positive emphasis on the Industrial Revolution as a major break in the course of history, the opening of an era of sustained technological change and economic growth. Great Britain was then experiencing a population miniexplosion. It could be argued that the very fact of being able so to multiply without incurring a Malthusian rupture—very different from earlier historical experience—was in itself evidence of the unprecedented power of the new technology. The British innovations had wider economic consequences because the demand for the products was potentially larger and supply more elastic. They had wider ramifications within the larger economy. Cheaper cottons displaced competing textiles large urban concentrations of industry occurred because the steam engine freed textile mills from water power and because the British economy redistributed labor.

  PublisherDOI

• Akustische Simulation von Fahrzeuggeräuschen innerhalb virtueller Umgebungen basierend auf künstlichen neuronalen Netzen (KNN)

  2017-01-01

  article

  Das Entwickeln neuer Produkte ist an viele Vorgaben geknupft, die z.B. von Seiten des Kunden gemacht werden oder die im Rahmen von Gesetzen existieren. Zu unterschiedlichsten Zeitpunkten im Produktentwicklungsprozess wird deshalb uberpruft, ob die gewunschten Produkteigenschaften erreicht werden. Hierfur ist es notwendig, Modelle bzw. Prototypen zu bauen. Dies ist oftmals mit gro{\ss}en Kosten und hohem Zeitaufwand verbunden. Virtual Reality (VR) kann eine Moglichkeit bieten, diesen finanziellen und zeitlichen Aufwand zu reduzieren, indem Prototypen virtuell dargestellt werden. So konnen z.B. Produkte in einer virtuellen Umgebung visualisiert werden, so dass das Aussehen und das visuelle Design bewertet werden konnen. Ob ein Produkt vom Kunden akzeptiert wird, hangt aber haufig auch von den akustischen Eigenschaften des Produktes ab. Fur viele Produkte gibt es daruber hinaus auch gesetzliche Regelungen, die vorschreiben, wie laut das vom Produkt abgestrahlte Gerausch sein darf. So wird es immer wichtiger, VR-Methoden zu entwickeln, mit denen akustische Eigenschaften von Produkten simuliert werden konnen. Eine besondere Herausforderung stellt hierbei die Simulation von dynamischen Gerauschen dar. Dynamisch bedeutet in diesem Zusammenhang, dass das Zeitsignal eines Gerausches nicht linear beschrieben werden kann und keine Periodizitat aufweist. Der Begriff dynamisch bezieht sich hierbei auf den Klang des Gerausches, der nicht gleichbleibend ist, sondern standigen Anderungen unterworfen ist.Im Beitrag wird ein Konzept fur die Simulation von dynamischen Fahrzeuggerauschen vorgestellt. Das Konzept basiert auf dem Einsatz kunstlicher neuronaler Netze (KNN). Fahrzeuggerausche sind abhangig von unterschiedlichen Parametern wie z.B. der Geschwindigkeit, dem Gang oder dem Lastzustand. Unter Berucksichtigung dieser Abhangigkeiten sollen Audioaufnahmen von Fahrzeuggerauschen angepasst werden. Die Audioaufnahmen wurden in Form von akustischen Messungen an verschiedenen Fahrzeugen und deren Komponenten erstellt. KNNs werden erfolgreich zum Klassifizieren von Bilddaten verwendet und auch fur die Audiosignalverarbeitung sind sie geeignet. So werden KNNs zum Beispiel fur Spracherkennungstools eingesetzt. Beide Anwendungsfelder basieren auf einer gut funktionierenden Merkmalsextraktion. Das im Beitrag beschriebene KNN wird so trainiert, dass die Merkmalsextraktion vom Netz selbst in unabhangiger und selbststandiger Weise durchgefuhrt wird, ohne dass Merkmale vorgegeben werden mussen. So kann ermittelt werden, wie viele Merkmale benotigt werden, um Fahrzeuggerausche hinreichend genau zu beschreiben. Daruber hinaus wird untersucht, wie diese Merkmale aussehen und ob Zusammenhange mit bestimmten Fahrzeugparametern existieren. Auserdem wird beschrieben, wie solche Netze in ein bestehendes audio-visuelles VR-System integriert werden konnen.

  Publisher

Frequent coauthors

• Herman Krooss

  221 shared

• Hugh G. J. Aitken

  172 shared

• Dorothy S. Brady

  LaGuardia Community College

  156 shared

• Jane Gallman

  University of Wisconsin–Madison

  152 shared

• Robert E. Gallman

  152 shared

• David Herlihy

  152 shared

• Deborah Ascione

  University of Wisconsin–Madison

  140 shared

• Marvin Mclnnis

  106 shared

Education

• Ph.D., Economics

  Massachusetts Institute of Technology

  1962

• B.A., Economics

  Harvard University

  1958