97 research outputs found
First person – Shweta Yadav
No full textABSTRACT
First Person is a series of interviews with the first authors of a selection of papers published in Journal of Cell Science, helping early-career researchers promote themselves alongside their papers. Shweta Yadav is the first author on ‘RDGBα localization and function at membrane contact sites is regulated by FFAT–VAP interactions’, published in Journal of Cell Science. Shweta is a post-doctoral associate in the laboratory of Prof. Juan Botas at Baylor College of Medicine, Texas, USA, investigating neurodegenerative diseases.</jats:p
The social correlates of value consensus
No full textThis paper examines societal value consensus, or the extent to which individuals within a culture share similar values. This topic has been extensively theoretically discussed, but has received limited empirical attention. This paper explores the social variables of economic equality, religiosity and religious homogeneity and their relation to value consensus. Publicly available data from the latest wave of World Values Survey (N = 73,256), CIA world factbook and the World Bank World Development Indicators are used for analysis. Results reveal that value consensus is not correlated with religiosity, religious homogeneity or economic equality. Implications of these findings, with specific reference to economic developmental theories are discussed.M.A.Includes bibliographical referencesby Shweta A. Kulkarn
Adaptive geolocation based interference control for hierarchical cellular network with femtocells
No full textThis thesis presents adaptive interference control methods to mitigate undesirable interference effects from femtocells to macrocell users in hierarchical cellular networks. The study in this thesis begins by quantifying the deterioration in performance experienced by macrocell users on the downlink in a simulated 3G/CDMA environment. Our baseline results show that the median deterioration in signal-to-interference plus noise ratio (SINR) observed for the macrocell users may be up to 10dB and the outage probability increases by large extend. In the next part of study, we propose interference mitigation schemes - ‘Proximity Based Iterative’ (PBI) scheme and ‘Adaptive Interference Scaling’ (AIS) scheme to adjust femtocell power to reduce femtocell interference effect on macrocell users. We show that previously studied mechanisms like the load-spillage, utility based power adaptation usually require relatively high system overhead due to over-the-air signalling for estimation of interference. Proposed PBI and AIS schemes avoid such over-the-air signalling and make use of geo-location information and backhaul signalling for the femtocell interference estimation. These schemes achieve power re-distribution by scaling power uniformly across femtocells, while allowing the network operators to set desired target data rates. Results from simulations show that the PBI and AIS schemes are able to increase the number of macrocell users achieving chosen target data rates by up to 158% when compared with the value when femtocell transmission power is at maximum. However, in case of the PBI scheme, results shows that 25% of femtocell users may receive rates below the target rate. The AIS scheme provides an improvement over the PBI scheme by adjusting femtocell power according to the interference contribution by each femtocell. Thus, AIS achieves better performance and only up to 12:2% of femtocell users receive rates below the target rate. This study concludes with parametric evaluation of system throughput as a function of both macrocell and femtocell user densities. Qualitative results are provided to support the conclusion.M.S.Includes bibliographical referencesby Shweta Sagar
Improved EAACK: Develop secure intrusion detection system for MANETs using hybrid cryptography
No full textRoll-Call: an energy efficient radio frequency identification system.
No full textIn this thesis, we investigate two of the major challenges in pervasive systems: energy efficiency and co-existence of uncoordinated wireless messages by exploring the design of a Radio Frequency Identification (RFID) system intended to support the simultaneous and real time monitoring of thousands of entities. These entities, which may be individuals or inventory items, each carry a low-power transmit-only tag and are monitored by a collection of networked base-stations reporting to a central database. We have built a customized transmit-only tag with a small form-factor, and have implemented a real-time monitoring application intended to verify the presence of each tag in order to detect potential disappearance of a tag (perhaps due to item theft). Throughout the construction of our system, we have carefully engineered it for extended tag lifetime and reliable monitoring capabilities in the presence of packet collisions, while keeping the tags small and inexpensive.
The major challenge in this architecture (called Roll-Call) is to supply the energy needed for long range continuous tracking for a year or more of reporting once a second while keeping the tags (called PIPs) small and inexpensive. We have used this as a model problem for optimizing cost, size and lifetime across the entire pervasive, persistent system from firmware to protocol.M.S.Includes bibliographical references (p. 46-48)
Models and algorithms for spectrum coexistence in wireless networks
No full textIn the last decade, there have been several technological trends that have occurred together and have caused a shift in how wireless systems will be deployed. The significant increase in the capabilities of mobile devices, combined with the proliferation of Internet enabled services, and the improvement in the communication support provided by new waveforms for wireless communications, have initiated a shift from the traditional, macrocell-based cellular network to new forms of radio access technologies (RATs) involving multiple, smaller cells deployed in vicinity of each other. These small cells will often support diverse wireless technologies and be operated by different providers. The resulting heterogeneity, unfortunately, can lead to serious internetwork interference that can negate the improvement in overall system performance that was the original motivation for employing many small cells in close proximity. In this thesis, we examine different technologies that are needed for flexible spectrum management to support the coordination that is needed for coexistence between many small cell wireless networks. Motivated by the need for internetwork architectures that support spectrum coordination, we (1) conduct performance evaluation associated with the joint deployment of mobile and fixed hotspot networks, (2) develop spectrum models that characterize interference among different wireless entities, (3) provide new methods for efficient hardware emulation of wireless channels, (4) devise algorithms that estimate radio spectrum usage, and (5) provide algorithms for coordination between different wireless systems to improve the overall system performance and spectrum efficiency. The first part of the thesis investigates spectrum coexistence in wireless networks by exploring the underlying performance challenges that exist when mobile hotspots are deployed in an environment of densely deployed, static wireless access networks. Next part of thesis investigates design of hardware emulator of radio channels to accurately capture the effect of real-world wireless channels upon communications waveforms while minimizing computational complexity. Next, we explore a fundamental building block of spectrum management for supporting better utilization of radio spectrum which involves predicting the impact that an emitter will have at different geographic locations. We then examine various challenges associated with coordinating spectrum access between different wireless technologies by exploring the specific case of Wi-Fi and LTE coexistence in emerging unlicensed frequency bands. Finally, recognizing the broad challenges associated with addressing spectrum coexistence in emerging wireless systems, we identify several directions for future investigation and suggest different approaches for tackling these challenges.Ph.D.Includes bibliographical referencesby Shweta S. Sagar
Using freewriting to make sense of literature
No full textPeer reviewedPublished on The U.S. Department of State websit
ACQUISITIONS AND FOREIGN COMPETITION
No full textRights Copyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author. Downloaded 18-Sep-2016 01:38:3
Using Freewriting to Make Sense of Literature
No full textPeer reviewedPublished on The U.S. Department of State websit
The suitability of lean, six sigma and lean six sigma for small, medium and large scale firms
No full textLean six sigma uses a combination of lean thinking and six sigma project methodology called DMAIC (define, measure, analyze, improve, and control) to achieve high performing business results. The DMAIC approach is proven to help organizations achieve on time delivery of the right quality and quantity to satisfy customers. Lean thinking is based upon the reduction of waste and focused on added value. An important decision for an organization is to choose between lean, six sigma or some combination of these concepts. This paper studies the most relevant characteristics of the three methodologies based upon an original research study. A review of literature describes how organizations differ greatly in terms of scale and are categorized as small, medium (SME) and large. Based upon a maturity model concepts, this paper studies the characteristics of these organizations and proposes the best methodology among lean, six sigma, and lean six sigma. Maturity models represent the spectrum in which organizations operate process management and quality principles. The result of this study should help the organization represent the most suitable methodology based on the comparison of characteristics and requirements of the firm. The interaction of lean and six sigma methods and the environment in which lean, six sigma, or both, are implemented does not preclude analysis and pre-assessment of which method to adopt. This paper will help compare these methodologies on the basis of the goals and the context of the firm and help organizations choose the right approach. KEYWORDS: DMAIC (define, measure, analyze, improve, and control
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