93 research outputs found
Towards the Wearable Cardiorespiratory Sensors for Aerospace Applications
No full textIn safety-critical aviation operations, adaptive Human-Machine Interfaces (HMI) rely on accurate physiological monitoring to mitigate cognitive overload. While cardiorespiratory sensors are promising for real-time cognitive workload assessment, existing studies lack rigorous validation of consumer-grade devices in high-stress aviation contexts and fail to address measurement uncertainty propagation. This study evaluates the Zephyr BioHarness, a commercial wearable sensor, against clinical-grade equipment during arithmetic tasks simulating aviation cognitive demands. By integrating a neuro-fuzzy system with uncertainty propagation methods, we quantify the reliability of heart rate (HR) and breathing rate (BR) metrics for workload estimation. Results demonstrate moderate HR accuracy (RMSE: 4.85 bpm, CC: 0.66) but poor BR performance (RMSE: 9.73 bpm, CC: 0.09), attributed to inconsistent breath detection during cognitive strain. The novel uncertainty framework reveals workload prediction variances (σWL: 0.38–2.22) driven primarily by BR inaccuracies, emphasizing the need for improved respiratory sensing in adaptive HMI. This work pioneers the application of neuro-fuzzy systems for uncertainty analysis in aviation physiology, offering a validated methodology for sensor integration and highlighting critical limitations in current consumer-grade technologies. These findings advance the design of robust cognitive monitoring systems, ensuring safer and more efficient human-machine collaboration in aviation
Of the people, by the people, for the people: in defense of American pop culture, its meaning, and its impact
No full textAmerican pop culture has often been subjected to scorn and ridicule, both at home and abroad, often by those who view it as being immoral or who view it as not being “true” culture. This begs the questions of what exactly are the characteristics of American pop culture, why did it develop along the lines it has, and what are its sociological implications. One can examine the issue by delving into American history, and tracing how American mainstream thought has informed cultural practice. The results of such a study show that the characteristics of American pop culture were directly shaped by the ideals expressed in the American Revolution, and that American pop culture has often been at the heart of a generations-long push towards greater social freedom.M.A.Includes bibliographical referencesIncludes vitaby Avinash R. Chanda
Hand powered portable ultraviolet sterilizing water bottle with active UV dose sensing
No full textThesis (S.B.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, September 2007 [first author]; and, (S.B.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, June 2006 [second author].Includes bibliographical references (p. 71).A portable hand powered water sterilization device was created to address a portion of the growing epidemic of global water contamination. As being more supply chain independent and having an active dose sensing component that monitors the water to insure sterilization, our device boasts far more than any current off-the-shelf devices. The device is completely hand powered via a hand crank generator. A spermicidal ultraviolet light bulb, rated at 253.7nm (UV-C), was integrated with a common NalgeneTM water bottle. Along with the bulb, UV. dose sensing electronics and a hand crank generator were incorporated as well, with the generator supplying power to both the bulb and the photodiode circuitry. Results show that eradication of common waterborne bacteria, protozoa, and viruses occurs after cranking the generator for approximately 41 seconds in clear water and up to 65 seconds in turbid water. The total weight added to the water bottle was less than a pound.by Chandan Das and Justin Holland.S.B
Layer-by-layer hybrid chemical doping for high transmittance uniformity in graphene-polymer flexible transparent conductive nanocomposite
No full textA traditional transparent conducting film (TCF) such as indium tin oxide (ITO) exhibits poor mechanical flexibility and inconsistent transmittance throughout the UV-VIS-NIR spectrum. Recent TCFs like graphene films exhibit high sheet resistance (Rs) due to defect induced carrier scattering. Here we show a unique hybrid chemical doping method that results in high transmittance uniformity in a layered graphene-polymer nanocomposite with suppressed defect-induced carrier scattering. This layer-by-layer hybrid chemical doping results in low Rs (15 sq at >90% transmittance) and 3.6% transmittance uniformity (300-1000 nm) compared with graphene (17%), polymer (8%) and ITO (46%) films. The weak localization effect in our nanocomposite was reduced to 0.5%, compared with pristine (4.25%) and doped graphene films (1.2%). Furthermore, negligible Rs change (1.2 times compared to 12.6 × 103 times in ITO) and nearly unaltered transmittance spectra were observed up to 24 GPa of applied stress highlighting mechanical flexibility of the nanocomposite film. © 2018 The Author(s
Knowledge-based cluster development in India : opportunities and challenges
No full textThesis (S.M. in Real Estate Development)--Massachusetts Institute of Technology, Dept. of Architecture, Center for Real Estate, 2008.This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.Includes bibliographical references (p. 89-92).Knowledge-based industries tend to cluster. The nature of activities illustrate the importance of networks and virtual and proximity aspects of clustering. Review of existing literature brings out the advantages of clustering for such industries. The purpose of the study is to comprehend the current status of development, both economic and real estate, in the knowledge-based industries in India. A stylized model is used as a reference to understand the status of economic development. Current body of literature and interview results from this study suggests transitioning nature of India's knowledge-based industry from being a services provider to becoming a knowledge provider. However, there are challenges in the transition process related to infrastructure and human resource. This study suggests that a large scale mixed use project may in fact be able to address some of the ongoing issues in the economic domain. The proposed development may lead to clustering of business and universities thus, giving rise to a knowledge-based cluster in India.by Chandan Dev Singla.S.M.in Real Estate Developmen
Aesoper Galpa Samagra (Aesop's Fables: Bengali)
No full textHere is a genuine find in this sense: I found it without help on the shelves in this fine bookshop near St. Xavier's College in Kolkata. The picture on the cover, including a fox and some grapes, gave me the clue. It is my first book exclusively in Bengali; I have a bilingual copy of Fox Fables that has both Bengali and English. This book features about a dozen full-page black-and-white designs. Among the best of them are The Ethiopian and CW. I cannot give page numbers because those too are in Bengali! I am proud of finding this book on my busy day in Kolkata!This is a hardbound book (hard cover)Language note: BengaliRetold by Naresh Chandra Jan
Boosting photoresponse in silicon metal-semiconductor-metal photodetector using semiconducting quantum dots
No full textSilicon based metal-semiconductor-metal (MSM) photodetectors have faster photogeneration and carrier collection across the metal-semiconductor Schottky contacts, and CMOS integratibility compared to conventional p-n junction photodetectors. However, its operations are limited by low photogeneration, inefficient carrier-separation, and low mobility. Here, we show a simple and highly effective approach for boosting Si MSM photodetector efficiency by uniformly decorating semiconducting CdSe quantum dots on Si channel (Si-QD). Significantly higher photocurrent on/off ratio was achieved up to over 500 compared to conventional Si MSM photodetector (on/off ratio ∼5) by increasing photogeneration and improving carrier separation. Furthermore, a substrate-biasing technique invoked wide range of tunable photocurrent on/off ratio in Si-QD photodetector (ranging from 2.7 to 562) by applying suitable combinations of source-drain and substrate biasing conditions. Strong photogeneration and carrier separation were achieved by employing Stark effect into the Si-QD hybrid system. These results highlight a promising method for enhancing Si MSM photodetector efficiency more than 100 times and simultaneously compatible with current silicon technologies. © The Author(s) 2016111sciescopu
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‘Writing practices’ and Writing ‘practices’: observation and struggle in fieldnotes about artisanal work
No full textThis chapter presents a series of curated fieldnotes as a way to investigate a tension that is implicit in all ethnographic research on craft and other skilled activities: that what one can observe, and therefore what one records in fieldnotes, is not directly or wholly the subject of study. Through excerpts from fieldnotes that I made during twenty-two months of ethnographic research with woodcarvers and painters in San Martín Tilcajete, in the state of Oaxaca, Mexico, I show how the attempt to ‘get at’ artisanal practice through observation not only is a struggle for understanding and analysis but is also a struggle about how and what to write. Although many researchers have avoided the analytical impasse by utilising ‘apprenticeship’ as a research methodology and technique, the chapter shows that the problems of writing do not necessarily disappear when attention is focused on the researcher’s own practices rather than those of her research participants. The chapter concludes that although apprenticeship as a research method does afford an embodied and perceptive understanding of craft practices, the struggle of writing may signal something important about artisanal work that cannot be so easily captured in notes, photographs, film, or other media
Experimental characterisation of self-healing in reconstituted Boom Clay
No full textGreen Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Geo-engineerin
Fine tuning of size and morphology of magnetite nanoparticles synthesized by microemulsion
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