518 research outputs found
Ideas for rent: an overview of markets for technology
No full textThis article surveys some of the recent literature on technology markets, and summarizes its main issues and insights. We structure our analysis in three parts: the supply and demand of technology; the factors that condition the formation and growth of technology markets; industry structure and dynamic issues. In addition, we summarize some of the studies that have tried to document the size and growth of these markets. We find that the literature has focused mainly on the supply of technology, but several other aspects of these markets remain under-studied, including the demand for external technology, the role of uncertainty in technology markets, and the dynamic interaction between industry structure and the market for technology. Understanding these will illuminate whether markets for technology will continue to grow or remained confined to pockets of the economy. Copyright 2010 The Author 2010. Published by Oxford University Press on behalf of Associazione ICC. All rights reserved., Oxford University Press.
Metrics for analytics and visualization of big data with applications to activity recognition
No full textActivity recognition systems detect the hidden actions of an agent from sensor measurements made on the agents' actions and the environmental conditions. For such systems, metrics are important for both performance evaluation and visualization purposes. In this thesis, such metrics are developed and illustrated. For human activity recognition datasets, a reporting structure is described to visualize the metrics in a systematic manner. The other contribution of this thesis is to describe a visualization tool for estimating the orientation (attitude) of a rigid body from streaming motion sensor (accelerometer and gyroscope) data. A feedback particle filter (FPF) is implemented algorithmically to solve the estimation problem.Submission published under a 24 month embargo labeled 'Closed Access', the embargo will last until 2018-05-01The student, Rohan Arora, accepted the attached license on 2016-04-25 at 10:47.The student, Rohan Arora, submitted this Thesis for approval on 2016-04-25 at 10:48.This Thesis was approved for publication on 2016-04-27 at 15:05.DSpace SAF Submission Ingestion Package generated from Vireo submission #9459 on 2016-07-07 at 14:17:57Made available in DSpace on 2016-07-07T21:18:02Z (GMT). No. of bitstreams: 2
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Previous issue date: 2016-04-27Embargo set by: Seth Robbins for item 93308
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Reason: Author requested closed access (OA after 2yrs) in Vireo ETD systemLimited Restriction Lifted for Item 93308 on 2018-07-08T09:15:30Z
Mode Coupling and Nonlinearities in Micro/Nano Electromechanical Systems
No full textMicro and nanoelectromechanical systems have shown tremendous potential in applications ranging from sensing to obtaining ultrastable oscillators for timing. They have also opened avenues for fundamental quantum studies and exploring nonlinear dynamics. The advent of CNTs and two-dimensional materials has enabled extreme miniaturization of resonators, allowing mass sensitivities down to a proton limit. This is possible since the mass resolution is proportional to the mass of the resonator itself. The limit of detection is also proportional to the frequency stability of the resonator. This is a measure of the uncertainty associated with the frequency measurement. Frequency stability can be effected either by the measurement noise or noise intrinsic to the device's mechanical response.
In this thesis, we have explored the room temperature frequency stability of MoS2 resonators in the linear regime. The work involves the fabrication of local gated MoS2 resonators. The devices are characterized using capacitive actuation and homodyne detection techniques. Allan deviation is used as a tool to measure the frequency stability of MoS2 resonators. We study the effect of actuation drive (both AC and DC) on the resonator's frequency stability and correlate it with the signal to noise ratio of the device. The frequency stability measured in MoS2 resonators corresponds to a mass resolution of few attograms. We further identify the various noise sources present in the system through the slope of Allan deviation plots.
Recently, Antonio et al. have demonstrated improved frequency stability due to nonlinear intermodal coupling. Coupled resonators have also been shown to enhance the sensitivity of mass sensors and hold promise for future nanomechanical technologies. The linear and nonlinear coupling between modes and/or resonators has enabled the observation of dynamics similar to optomechanics, such as phonon lasing and state squeezing. Nonlinear coupling enables the transfer of energy between vibrational modes having resonant frequencies far apart. Internal resonance is the most common form of nonlinear coupling mechanism. The necessary condition for mechanical modes to be coupled through internal resonance is that the ratio of resonant frequencies of coupled modes should be close to an integer (n=1,2,3). Previous studies on internal resonance have been restricted to clamped-clamped beams. However, our expriemental understanding of modal coupling through internal resonance is limited as it requires the meticulous design of device parameters to obtain resonant modes that are commensurate. Two-dimensional materials such as graphene and metal dichalcogenides have highly tunable resonant frequencies, enabling internal resonance conditions to be easily satisfied. Moreover, vibrational modes of a two-dimensional resonator are coupled through the intrinsic strain in the membrane. Thus, two-dimensional materials serve as a great platform to understand the dynamics of coupled systems. In this work, we demonstrate strong tunable intermodal coupling due to 2:1 internal resonance in MoS2 drum resonators. The modal peak splitting, a signature of coupling, is observed in the linear regime itself in addition to the nonlinear regime. We show the tunability of this coupling with applied gate bias. The simulations enabled us to qualitatively understand the effect of excitation force, frequency detuning and modal coupling strength on the resonator dynamics. Understanding internal resonance in two-dimensional membranes would enable new possibilities in signal transduction and frequency conversion. It could also help in improving the frequency stability of MoS2 resonators through the intermodal coupling.
Coupling between different modes of a resonator is not just limited to two-dimensional materials but has also been reported in MEMS structures like clamped-clamped beams and curved arches. Advanced fabrication techniques have paved the way for a new class of MEMS structures, the piezo-micromachined ultrasonic transducer (pMUT). The majority of pMUTs/diaphragms are designed to operate in a linear dynamic range. But, at larger vibrational amplitudes, the nonlinear effect strongly affects the device dynamics. Careful control of these nonlinearities could pave the way to improved stability in microsensors, such as phase fluctuation reduction, frequency control and in-situ amplification schemes. Thus, it is imperative to understand and tune device nonlinearities. Previously tuning of nonlinearities has been achieved in mechanical resonators using capacitive techniques. But the same has not been demonstrated for piezoelectrically actuated ZnO diaphragms. In this thesis, we present the tuning of nonlinearity through diaphragm curvature in these devices. We calculate the effective nonlinearity through the device's backbone curve response and relate it with the diaphragm curvature. Nonlinearity in these resonators also leads to intermodal coupling and energy exchange between the commensurate vibrational modes. We further demonstrate the transfer of energy from the coupled higher vibrational mode to the fundamental mode of the pMUT. This coupling in the future would enable ultrastable piezo-based oscillators
Global, Regional and Local Influences in The Relationship between Asset Returns and The Macro Economic Factors in India
No full textAsset pricing is a well researched topic in financial studies. This topic holds interest as it is directly related with the concept of wealth creation. Asset prices move with changes in the environment (Cheung and Ng, 1998). The changes including business environment, economic policies, social factors and political movements affect the asset pricing and in turn the expected returns from these assets. The asset pricing models developed so far have been reasonably successful in determining the relationship between extrinsic factors and the value of assets (Levine and Zervos, 1998). The models also highlight the degree of effects of such external movements to the asset pricing.
This dissertation is my attempt to come out with an asset pricing model for the Indian stock market taking into account the macroeconomic forces actively influencing the asset pricing. The dissertation shall collect the data of 36 Indian portfolios and 7 macro economic factors affecting the Indian stock market. The dissertation shall also bring out the bifurcation of macroeconomic factors into Local, Regional and Global macroeconomic factors. The key observation of the dissertation shall be to develop a relationship based on the past data in terms of calculating asset returns due to changes in Global, Regional & Local economic factors (Cheung and Ng, 1998).
I shall be utilizing the research results of Chen, Roll & Ross: The APT model and the CAPM model for designing an effective model for the stated problem. The key limitation of the dissertation shall be that it is based on the past data and that past trends may not be followed in future
First generation Asian immigrants and mental health treatment
No full textAny first generation immigrant has a hard time assimilating to life in a new country, and this holds true for the Asian population and their mental health (Arora et al., 2020). This project focused on what impacts mental health of first generation Asian immigrants.Research presentationFaculty Mentor: Dr. Kathy Andrese
Global, Regional and Local Influences in The Relationship between Asset Returns and The Macro Economic Factors in India
No full textAsset pricing is a well researched topic in financial studies. This topic holds interest as it is directly related with the concept of wealth creation. Asset prices move with changes in the environment (Cheung and Ng, 1998). The changes including business environment, economic policies, social factors and political movements affect the asset pricing and in turn the expected returns from these assets. The asset pricing models developed so far have been reasonably successful in determining the relationship between extrinsic factors and the value of assets (Levine and Zervos, 1998). The models also highlight the degree of effects of such external movements to the asset pricing.
This dissertation is my attempt to come out with an asset pricing model for the Indian stock market taking into account the macroeconomic forces actively influencing the asset pricing. The dissertation shall collect the data of 36 Indian portfolios and 7 macro economic factors affecting the Indian stock market. The dissertation shall also bring out the bifurcation of macroeconomic factors into Local, Regional and Global macroeconomic factors. The key observation of the dissertation shall be to develop a relationship based on the past data in terms of calculating asset returns due to changes in Global, Regional & Local economic factors (Cheung and Ng, 1998).
I shall be utilizing the research results of Chen, Roll & Ross: The APT model and the CAPM model for designing an effective model for the stated problem. The key limitation of the dissertation shall be that it is based on the past data and that past trends may not be followed in future
Towards automated classification of fine-art painting style: a comparative study
No full textThis thesis presents a comparative study of different classification methodologies for the task of fine-art genre classification. The problem of painting classification involves classifying new unknown paintings among different art genres. Two-level comparative study is performed for this classification problem. The first level reviews the performance of discriminative vs. generative models while the second level touches the features aspect of the paintings and compares Semantic-level features vs low-level and intermediate-level features present in the painting. Three models are studied and compared, namely - 1) A Discriminative model using a Bag-of-Words (BoW) approach; 2) A Generative model using BoW; 3) Discriminative model using Semantic-level features. Various experiments and techniques like Bag of Words model, Topic models and Classeme features are employed to get insights into potential of these automatic classification techniques for painting styles.M.S.Includes bibliographical referencesby Ravneet Singh Aror
Micro-power Pulsed-Doppler Radar Clutter and Displacement Source Classification Dataset
No full textThis is the official dataset for the ACM BuildSys 2019 publication One Size Does Not Fit All: Multi-Scale, Cascaded RNNs for Radar Classification.
The training code for MSC-RNN can be found at https://github.com/dhruboroy29/MSCRNN
Kindly cite this work as:
@article{roy2019one,
title={One Size Does Not Fit All: Multi-Scale, Cascaded RNNs for Radar Classification},
author={Roy, Dhrubojyoti and Srivastava, Sangeeta and Kusupati, Aditya and Jain, Pranshu and Varma, Manik and Arora, Anish},
journal={arXiv preprint arXiv:1909.03082},
year={2019}
}
</pre
Correction to: Visual acuity correlates with multimodal imaging-based categories of central serous chorioretinopathy (Eye, (2021), 10.1038/s41433-021-01788-4)
No full textIn this article the author name Ramesh Venkatesh was incorrectly written as Ramesh Vankatesh. The original article has been corrected
Removal of soy protein-bound phospholipids by a combination of sonication, β-cyclodextrin, and phospholipase A2 treatments
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