1,393 research outputs found
Evolving provenance in the Proterozoic Pranhita-Godavari Basin, India
No full textAbstract not available.Udeni Amarasinghe, Asru Chaudhuri, Alan S. Collins, Gautam Deb, Sarbani Patranabis-De
Draft genome sequence of Leuconostoc falkenbergense isolated from naturally fermented buffalo milk curd
No full textThis study reports the draft genome of Leuconostoc falkenbergense strain BSMRAU-M1L5, isolated from artisanal buffalo milk curd in Bangladesh. The draft genome spans 1,776,471 bp, with 50× coverage and 96 contigs.Mst. Umme Habiba, M. Nazmul Hoque, Shabbir Ahmed, Tofazzal Islam, Gautam Kumar Deb, Md. Morshedur Rahma
Neural correlates of elbow joint kinematic variability:
No full textA fundamental tenet of motor control is that point-to-point reaching motions follow an approximately straight line trajectory with a bell-shaped velocity profile. However, these abstractions are not universally observed. Previous work in our lab revealed that most spatiotemporal elbow trajectories do not necessarily conform to a straight-line, which is believed to be ‘natural’ human motion. Instead, spatiotemporal trajectories are best characterized by a small set of simple, analytic functions including both linear and non-linear waveforms. Here, I suggest that the differences observed in elbow kinematics are a direct consequence of varying motor planning, which is represented by the electromyography (EMG).
Fourteen healthy subjects were asked to perform several self-paced, untargeted elbow articulations that maximize smoothness within a comfortable range of motion; EMG of the biceps and kinematic traces were recorded simultaneously. Kinematic traces were modeled by a set of simple, monotonic functions, while EMG traces were reconstructed by parabolic waveforms, via a parameterized curve-fitting method. EMG traces (r-EMG) and their parabolic reconstructions (p-EMG) were used independently to predict adherence to each of 3 kinematic types. It was hypothesized that the p-EMG and r-EMG from the kinematic adherence group (r2 > 0.9979) would exhibit statistical and parametric differences from the departure group (r2 < 0.9951) of the same kinematic type.
Both r-EMG and p-EMG were useful in predicting adherence to global kinematic morphology with high sensitivity and specificity across subjects. Coupling the substantial predictive value and the similar information content (87.80% of the decisions were identical) of both EMG modalities implied that p-EMG can be used as a simple, informative approximant of r-EMG of the biceps during self-paced, untargeted elbow flexions. The features selected for classification were robust across subjects along with the predictive value, suggesting there is degeneracy in the neural command. Degeneracy in the neural command matches the widespread observation of highly stereotyped kinematics. Elbow trajectories most commonly adhered to sigmoid morphology. Future work should develop a comprehensive depiction of the neural control of voluntary movements.M.S.Includes bibliographical references (p. 44-45)by Gautam Siddarth Nataraja
Modern challenges in distribution testing
No full textThesis: Ph. D., Massachusetts Institute of Technology, Department of Electrical Engineering and Computer Science, 2018.This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.Cataloged from student-submitted PDF version of thesis.Includes bibliographical references (pages 321-356).Hypothesis testing is one of the most classical problems in statistics. While it has enjoyed over a century of intense study, only recent focus has been on the small-sample regime, with interest in sample complexities and minimax rates. Our understanding of many fundamental problems is now quite mature, but there are several questions which have arisen over the last decade, which have not yet received adequate attention. The goal of this dissertation is to identify and address several contemporary challenges in distribution testing. In particular, we make progress in answering the following questions: ** Can we test distributions with tolerance to model misspecification? ** How does the complexity of distribution testing change as we consider different measures of distance? ** Can we efficiently test for membership in (potentially infinite) classes of distributions? ** How can we avoid the curse of dimensionality when testing multivariate distributions? ** Is it possible to perform hypothesis testing on sensitive data, while respecting privacy of the dataset? ** Can we design more efficient algorithms if the dataset is sampled actively? Directions for further investigation are also discussed.by Gautam Kamath.Ph. D
Network virtualization on the wireless edge
No full textThis thesis presents a comprehensive investigation of wireless network virtualization, a technique for creating multiple independent software-definable networks on a single set of commercial hardware resources. Network virtualization has previously been applied to wired networking scenarios, but the general problems of wireless virtualization represents an important open problem that we address in this work. In particular, we identify key technical challenges, system concepts and architectures, as well as specific protocols and algorithms for implementing wireless network virtualization. In summary, this thesis will provide results for following aspects of wireless network virtualization: (1) Basic mechanisms for link (spectrum) sharing and their isolation performance with virtual WLAN networks, (2) Virtualization mechanisms and traffic isolation algorithms for virtualized WiFi networks, (3) Virtualization of cellular basestations including experimental evaluation for a prototype 4G/WiMAX network, and finally, (4) analytical evaluation of virtualization algorithms for more general multi-hop wireless topologies. The first part of the thesis presents an exploratory discussion on the co-existence of multiple 802.11 based virtual networks. A comparison is presented for understanding the tradeoffs between sharing the radio through spatial and temporal separation on the ORBIT wireless testbed. Experimental evaluations reveal that while virtual networks sharing channel resources by space separation achieve better efficiency than those relying on time, the isolation between experiments in both cases is comparable. Supporting virtualized WiFi access point based networks allows for a convenient sharing of a physical access point across multiple ISPs or network operators. The second part of the thesis discusses our SplitAP architecture, which builds on the virtual access point (VAP) mechanism by extending it to support fair-sharing of airtime across multiple wireless networks. This is done by implementing a dynamically controlled isolation framework across competing slices. The framework also allows the user to deploy custom algorithms for enforcing uplink airtime fairness across client groups within the SplitAP framework. The thesis shows up to 40% improvement in isolation measured through a modified Jain fairness index with LPFC and LPFC+, two sample algorithms implemented on the framework. The third part of the thesis addresses the challenge of virtualization of resources in a cellular basestation (BTS) while allowing operators to use distinct flow types, quota allocations, slice schedulers, and network layer protocols. The proposed virtual basestation architecture is based on an external substrate which uses a layer-2 switched datapath, and an arbitrated control path to the WiMAX base station. The virtual network traffic shaping (VNTS) slice isolation mechanism allows the virtual basestation users to obtain at least an allocated percentage of the BTS resources in the presence of saturation and link degradation, helping make the performance repeatable. Performance measures such as fairness index and coupling coefficient are defined and evaluated experimentally, showing significant improvements with preliminary indoor mobility experiments. Outdoor vehicular measurements show similar improvements in the fairness index and coupling coefficient, demonstrating the feasibility of the proposed VNTS algorithms. Finally, a theoretical formulation describes how a mapping mechanism can be used for provisioning and allocating resources on wireless networks that are supported by wireless virtualization schemes such as the virtual basestation and the SplitAP framework. Results show that the wireless mapping problem can be reduced to solving a combinatorial optimization problem at nodes selected greedily based on their capabilities to generate revenue. Detailed simulations are discussed for highlighting the performance of the proposed greedy static allocation (GSA) and greedy dynamic re-allocation (GDR) algorithms.Ph. D.Includes bibliographical referencesIncludes vitaby Gautam Dilip Bhanag
The New Power Generation : Hybridity in Gautam Malkani’s Londonstani
No full textThis thesis examines how hybrid cultures develop in urban spaces, and it focuses on the South-Asian diaspora in London. Second generation immigrants often find themselves placed between two very different cultures, and they have a unique way of adapting and forming new types of identities. Some of these subcultures subsequently become part of British mainstream society, and new ways of being British emerge.
This is precisely the situation portrayed in Londonstani (2006) by Gautam Malkani. The novel is the story of teenager Jas, who, together with Amit and Ravi, is part of hard hitting Hardjit’s gang or “crew.” Set in Hounslow, London, sometime after September 11, these rudeboy “desis” are attempting to remove themselves from mainstream culture and are instead creating their own “cut-and-paste identities” where they mix and match from various cultural influences, from American hip-hop culture to Bollywood movies and Bhangra music.
Chapter two explores how the term hybridity is defined and applied in post-colonial theory, and looks at differences in use between hybridity in colonial settings contra hybridity in post-independence settings, particularly in the metropolitan immigrant setting.
The third chapter examines the hybrid culture of Londonstani, and looks at some of the challenges immigrants have faced in Britain, and how these have changed over the last decades. The argument is that there is a major difference between how first generation immigrants and subsequent generations relate to their ethnic identity, and this will be investigated further.
Chapter four looks at the hybrid vernacular language in Londonstani. The novel is written in the “desi” jargon, and the author has put a lot of effort into making it recognizable and seem authentic. Special emphasis will be placed on analysis of the dialogue to discover where the different influences are from, and also examine the reasons for writing in a hybrid form of English
Seismic performance of buildings in nepal after the gorkha earthquake
No full textFollowing the strong earthquake of Gorkha, Nepal, on April 25, 2015, and a strong aftershock on May 12, a field reconnaissance of structural damage and structural collapses was performed around the affected areas, particularly in the region around the capital Kathmandu. The main goal was to develop detailed descriptions of the seismic performance of the Nepalese building stock. To achieve this goal, the field reconnaissance survey was carried out after the two main seismic events. In this chapter, a summary of the survey is provided, focusing on both recent reinforced concrete (RC) buildings and older substandard constructions. In addition, detailed descriptions of the observed damage to urban masonry building stock and rural vernacular constructions are provided. This chapter presents evidence from the field that justifies the observed seismic performance and enables the depiction of damage modes, which could be insightful regarding future efforts to develop earthquake-resistant constructions and strategies to improve the seismic behavior around the world.info:eu-repo/semantics/publishedVersio
From a Problem to the Problem System
No full textThis case study brings to the fore designer‘s experience and challenges of intervening in a complex social system. The presentation refers to the “Need Assessment Study of Occupational and Health Hazards Faced by Desludging Workers in a City in India.” This study marked the first milestone towards understanding the safety concerns of sanitation workers in the larger context of safe sanitation practices in small and medium towns in India, where faecal sludge management is emerging as a viable way forward under the larger system of faecal sludge management. This paper focuses on the research methodology and processes used in the study in order to better understand how these might be replicated or used in other similar contexts. In particular, the presentation shall discuss the interrelationships at length to understand the dynamic, multicausal, and unpredictable nature of the complex social system as found during the study. Conducted in two Indian cities, the de-sludging operators offer cleaning services to households, establishments, and industries. (Mamta Gautam et al,19).
This presentation discusses the research design, its implementation, and findings leading to systemic design. This is being discussed from the perspective of the author as the lead design researcher for the project commissioned by IIHS
Comparative outcomes of drug eluting stents and drug eluting balloons in treating in-stent restenosis
No full textIntroduction
Several treatment modalities have been proposed and used for bare-metal in-stent restenosis (ISR). We compared the efficacy of drug-eluting balloons (DEB) versus drug-eluting stents (DES) in the treatment of ISR in terms of binary restenosis, target lesion revascularization (TLR) and late lumen loss (LLL) by coronary angiography at 6 months.
Material and methods
A total of 41 patients were enrolled in the study. The patients were then randomized to the two arms of the study wherein the control group was treated by the implantation of a second-generation DES and the study group was treated with a paclitaxel-eluting DEB. Late lumen loss and any ISR (the difference between the in-segment minimal lumen diameter (MLD) after the procedure and at 6 months) was the primary end point. Secondary end points included the rate of restenosis and the rate of the combined clinical events up to 6 months, including stent thrombosis, target-lesion revascularization, myocardial infarction, and death.
Results
There was a statistically significant difference between DEB and DES treatment in the immediate post-procedure outcome, with DES giving a better immediate post-procedure outcome. No significant difference was observed in late lumen loss between patients treated with either DEB or DES at 6 months follow-up.
Conclusions
There was no significant difference in the late lumen loss with either DEB or DES for treatment of ISR
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