1,483 research outputs found
On Smarandache rings
Get PDFThe study of Smarandache Algebraic structures was initiated in the year 1998 by Raul Padilla following a paper written by Florentin Smarandache called "Special Algebraic Structures"
Control under communication constraints
No full textThesis (Ph.D.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2000.Includes bibliographical references (p. 224-228).This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.by Sekhar Chandra Tatikonda.Ph.D
Adaptive multimodal integration of speech and gaze:
No full textSpeech has been used as the foundation for many human/machine interactive systems to convey the user’s intent to the system. However, other input mechanisms, commonly called modalities, such as gaze, touch, and hand gestures, have been explored as a means of providing a more robust interaction in environments where speech alone is not adequate. By combining the inputs from multiple, complementary modalities, none of which is perfectly reliable, a better understanding of the user’s true intent can be imparted to the system. In this dissertation, the effectiveness of using gaze (where someone is looking) to aid speech in providing the user’s intent to the machine is explored. To create a speech and gaze integration model, two human factors experiments were conducted to collect data for building this model. The first experiment had the user read a single word displayed on a screen, and the second experiment required the user to read a designated word from a menu of words. Speech onset time and the user’s gaze patterns data were captured
and analyzed to understand the timing relations between the two modalities. A set of gaze/speech
features were extracted from the data and used to predict the location of the word that the user read. The best features and the best model for predicting the location of the target word were found through an iterative trial and error process. A linear model was able to predict the gaze location of the target as well as any of the non-linear models considered. The linear system
representation was then used to create an adaptive model using the Row Action Projection (RAP) technique. The RAP adaptation model was found to predict the user’s intent with higher probability for the majority subjects than the non-adaptive approaches. The RAP model adapted to the speech/gaze patterns of each individual user as well as the variation in a single user’s interaction behavior over time. It was also found that the feature set used for successfully identifying the target in Experiment 1, a simple isolated word task, was different than that used in Experiment 2, a more complex menu selection task, suggesting that task complexity was an important consideration in the design of a speech/gaze interface. In summary, this dissertation has shown that an adaptive gaze and speech integration model is better than speech or gaze
performance alone.Ph.D.Includes bibliographical references (p. 155-166)by Chandra Sekhar Mantravad
Optimal sequential vector quantization of Markov sources
Get PDFIncludes bibliographical references (p. 30-31).Supported by U.S. Army grant. PAAL03-92-G-0115 Supported by a Homi Bhabha Fellowship and the Center for Intelligent Control Systems.V.S. Borkar, Sanjoy K. Mitter, Sekhar Tatikonda
A star-forming galaxy at z= 5.78 in the Chandra Deep Field South
Get PDFWe report the discovery of a luminous z = 5.78 star-forming galaxy in the Chandra Deep Field South. This galaxy was selected as an ‘i-drop’ from the GOODS public survey imaging with the Hubble Space Telescope/Advanced Camera for Surveys (object 3 in the work of Stanway, Bunker & McMahon 2003). The large colour of (i′−z′)AB = 1.6 indicated a spectral break consistent with the Lyman α forest absorption shortward of Lyman α at z≈ 6. The galaxy is very compact (marginally resolved with ACS with a half-light radius of 0.08 arcsec, so rhl 5. Our spectroscopic redshift for this object confirms the validity of the i′-drop technique of Stanway et al. to select star-forming galaxies atz≈ 6
Negatively supercharging cellulases render them lignin-resistant
No full textNon-specific adsorption of cellulases to lignin hinders enzymatic deconstruction of lignocellulosic biomass. Here we tested the hypothesis that negatively supercharging cellulases could reduce lignin inhibition. Computational design was used to negatively supercharge the surfaces of Ruminoclostridium thermocellum family 5 CelE and a CelE-family 3a carbohydrate binding module fusion. Resulting designs maintained the same expression yield, thermal stability, and nearly identical activity on soluble substrate as the wild-type proteins. Four designs showed complete lack of inhibition by lignin but with lower cellulose conversion compared to original enzymes. Increasing salt concentrations could partially rescue the activity of supercharged enzymes, supporting a mechanism of electrostatic repulsion between designs and cellulose. Results showcase a protein engineering strategy to construct highly active cellulases that are resistant to lignin-mediated inactivation, although further work is needed to understand the relationship between negative protein surface potential and activity on insoluble polysaccharides.Peer reviewe
ON SMARANDACHE RINGS
Get PDFIt is proved that a ring R in which for every x ∈ R there exists a (and hence
the smallest) natural number n(x) > 1 such that xn(x) = x is always a Smarandache
Ring. Two examples are provided for justification
Bedroom ventilation: Review of existing evidence and current standards
No full text10.1016/j.buildenv.2020.107229Building and Environment184107229-10722
Estimation of gross primary production of irrigated maize using Landsat-8 imagery and Eddy Covariance data
No full textAbstractA study was conducted to understand the potential of Landsat-8 in the estimation of gross primary production (GPP) and to quantify the productivity of maize crop cultivated under hyper-arid conditions of Saudi Arabia. The GPP of maize crop was estimated by using the Vegetation Photosynthesis Model (VPM) utilizing remote sensing data from Landsat-8 reflectance (GPPVPM) as well as the meteorological data provided by Eddy Covariance (EC) system (GPPEC), for the period from August to November 2015. Results revealed that the cumulative GPPEC for the entire growth period of maize crop was 1871gCm−2. However, the cumulative GPP determined as a function of the enhanced vegetation index – EVI (GPPEVI) was 1979gCm−2, and that determined as a function of the normalized difference vegetation index – NDVI (GPPNDVI) was 1754gCm−2. These results indicated that the GPPEVI was significantly higher than the GPPEC (R2=0.96, P=0.0241 and RMSE=12.6%). While, the GPPNDVI was significantly lower than the GPPEC (R2=0.93, P=0.0384 and RMSE=19.7%). However, the recorded relative error between the GPPEC and both the GPPEVI and the GPPNDVI was −6.22% and 5.76%, respectively. These results demonstrated the potential of the landsat-8 driven VPM model for the estimation of GPP, which is relevant to the productivity and carbon fluxes
Dismantling myths on the airborne transmission of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2)
Get PDFThe coronavirus disease 2019 (COVID-19) pandemic has caused untold disruption throughout the world. Understanding the mechanisms for transmission of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) is key to preventing further spread, but there is confusion over the meaning of ‘airborne’ whenever transmission is discussed. Scientific ambivalence originates from evidence published many years ago which has generated mythological beliefs that obscure current thinking. This article collates and explores some of the most commonly held dogmas on airborne transmission in order to stimulate revision of the science in the light of current evidence. Six ‘myths’ are presented, explained and ultimately refuted on the basis of recently published papers and expert opinion from previous work related to similar viruses. There is little doubt that SARS-CoV-2 is transmitted via a range of airborne particle sizes subject to all the usual ventilation parameters and human behaviour. Experts from specialties encompassing aerosol studies, ventilation, engineering, physics, virology and clinical medicine have joined together to produce this review to consolidate the evidence for airborne transmission mechanisms, and offer justification for modern strategies for prevention and control of COVID-19 in health care and the community.</p
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