508 research outputs found
Performance analysis of the WiNC2R platform:
No full textA Cognitive Radio (CR) is an intelligent transceiver device, able to support multiple technologies, dynamic re-configurability, ease of programming and collaboration with other CR devices to improve the communication efficiency. The two key requirements for an efficient CR implementation are flexibility in operation/programming and speed.
WiNC2R (Winlab Network Centric Cognitive Radio) achieves high speed of operation using its hardware platform and flexibility using its software-configurable architecture. The current WiNC2R architecture implements an 802.11a-like OFDM flow. We evaluate the WiNC2R hardware architecture to see the modularity in the architecture, separation of data and control flow and the performance in terms of latency and throughput. To test the system, the Xilinx Bus Functional Model environment, which is designed to test the IBM standard bus-architecture-based hardware systems, is used. We use a simple ALOHA protocol in the MAC layer to communicate between two WiNC2R nodes and evaluate the performance under the best-case scenario, where the performance is only hindered by the architecture itself rather than external conditions like channel state.
The results of our basic experiments showed that for a single OFDM 802.11a-like flow, the Unit Control Modules (UCM) were idle for almost 80% of the total processing time.
We then tested the WiNC2R system to study the effects of changing the frame size. It was seen that the latencies in the WiNC2R transmitter are frame-size dependent while those in the receiver mainly depend on the size of the data in the last chunk rather than the size of the whole frame. We suggest that chunk size should be 2 OFDM symbols, and chunking be moved to MAC layer for better performance. We give analytical estimates of resulting performance improvement. In the next experiment, we describe virtualization in the WiNC2R by adding more flows. We describe the steps to implement the additional flows and estimate maximum number of concurrent flows possible.
In the last analysis, we show the effect of operating clock frequency on the performance. We prove that at 250 MHz operating frequency and 2 OFDM symbols per chunk, the current WiNC2R implementation will be able to satisfy the SIFS criterion.M.S.Includes bibliographical references (p. 72-73)by Sumit Satarka
Prevalence of dental caries, periodontitis, and oral hygiene status among 12-year-old schoolchildren having normal occlusion and malocclusion in Mathura city: A comparative epidemiological study
No full textObjective: The aim was to find the prevalence of dental caries, periodontitis, and oral hygiene index-simplified (OHI-S) among 12-year schoolchildren having normal occlusion and malocclusion in Mathura city.
Materials and Methods: The present study was a cross-sectional study done among the 100 subjects who have been selected from 5 schools in four different geographical locations. The data regarding their socio-demographic characteristics, dental caries status, periodontitis status and oral hygiene status was collected using structured proforma. Means, standard deviations and test of significant were used as statistics to describe the data.
Results: The results showed that there was no significant difference between dental caries status, periodontitis status among subjects having normal occlusion and malocclusion (P = 0.06, 0.093) but significant relationship was found OHI-S and children who were having malocclusion (and P = 0.022). Significant difference was also found between periodontitis and oral hygiene status (P = 0.00).
Conclusion: It was observed from the present study that normal occlusion and malocclusion had no or weak significant effect on overall caries and periodontitis prevalence whereas oral hygiene status had a strong effect on overall periodontitis prevalence but not in relation to prevalence of dental caries in 12-year-old school children in Mathura city
HYBRID BIOMETRIC AUTHENTICATION PROTOCOL DESIGN USING PROVERIF
No full textME, CSEDThe thesis presents verification of OAUTH and OAUTH2 . ProVerif is used as the verification tool for verifying and analysing the protocols. The protocol are analysed in ProVerif model. Various attacks to the protocols are generated in order to verify whether the protocols hold their intended properties.We have selected 2 protocols and proposed a Hybrid biometric authentication protocol for social login. Each of which has different intended purposes and properties. The first protocol is generic authentication highlighting the deficiencies.It suffers from a large count of vulnerabilities like CSRF attack,phishing attacks and so on. The second protocol is a new evolution of previous protocol with major changes in data flow and and security aspects.Though,it overcomes many of the vulnerabilities but still the security of data was questionable. Hence, third protocol was designed so that the intensional authentication property can be verified. The protocol promises three intended properties: privacy of the biometric data, liveness of biometric data used as a salt in token secret of MAC token used in OAUTH2 and intensional authentication. The protocol is illustrated in detail and desirable properties of the protocol are verified
Visual acuity correlates with multimodal imaging-based categories of central serous chorioretinopathy
No full textObjective To evaluate visual acuity (VA) and factors influencing VA using new multimodal imaging-based classification of central serous chorioretinopathy (CSCR). Methods Retrospective, observational and cross-sectional study on 229 naive eyes diagnosed as CSCR with available baseline data and multimodal imaging. Each case was classified into (i) simple/complex/atypical; (ii) primary/recurrent/resolved; (iii) persistent or not; (iv) outer retinal atrophy(ORA) present/absent; (v) foveal involvement present/absent; and (vi) macular neovascularization(MNV) present/absent. Best corrected visual acuity (BCVA) was correlated to the classification as well as every parameter of the classification. Results Median BCVA was 0.18 logMAR [95% Confidence Interval (CI)0.16-0.18] with median duration of complaints of one month (95% CI,6.14-13.0 months). Age of the patient (r = -0.24, p = 0.002) and duration of the disease (r = -0.32, p < 0.001) correlated significantly with BCVA. Logistic regression model showed that older age [odds ratio (OR) = 0.96, p = 0.05], female gender (OR = 2.45, p = 0.046), presence of ORA(OR = 0.34, p = 0.012),and foveal involvement(OR = 0.18, p = 0.007) were statistically significantly associated with poorer BCVA. Eyes classified as complex, persistent CSCR, with ORA or foveal involvement demonstrated lower BCVA compared to those with simple, non-persistent CSCR, without ORA or without foveal involvement (p < 0.05). Eyes with complex CSCR (p < 0.001), atypical CSCR(p = 0.025), persistent subretinal fluid (SRF) (p = 0.001) and those with ORA (p < 0.001) demonstrated a trend towards severe visual loss. Prevalence of persistent SRF, recurrent episodes and ORA was significantly higher among eyes with complex CSCR (p < 0.001) while there was no difference in prevalence of resolved cases (p = 0.07), foveal involvement (p = 0.28) and MNV (p = 0.45) between simple and complex cases. Conclusion There is a strong correlation between VA and foveal involvement and ORA using the new classification. Thus, the objective parameters of the classification can be incorporated in establishing the treatment guidelines for CSCR
Query optimization in mobile environments
No full textWe consider the issue of optimizing queries for distributed processing in mobile environment. An interesting characteristic of mobile machines is that they depend on battery as a source of energy which may not be substantial enough. Hence, the appropriate optimization criterion in a mobile environment considers both resource utilization and energy consum- ption at the mobile client.
In this scenario, the optimal plan for a query depends on the residual battery level of the mobile client and the load at the server. We approach this problem by compiling a query into a sequence of candidate plans, such that for any state of the client-server system, the optimal plan is one of the candidate plans.
A general solution is proposed by adapting the partial order dynamic programming search algorithm (p.o dp) such that the coverset of the query is the set of candidate plans. We propose two novel algorithms, namely, the linear combinations algorithm and the linearset algorithm (referred to as the linear algorithms) that compute the linearset of a query. The linear- set of a query is an approximation to the coverset returned by p.o. dp.
We show, by means of simulation, that (1) the linearset is an excellent approximation of the coverset, (2) query compilation using the linear algorithms outperform query compilation using p.o. dp by factors ranging from 2 to 9, (3) the time taken to compile queries using the linear algorithms for the general optimization criterion is at most twice the time taken by a System R* like standard query optimizer search algorithm, and (4) the run time overhead incurred by the linear algorithms technique is minimal.
The techniques presented in the paper are of general applicability to multi-criterion optimization problems in distributed databases, where each criterion is an additive metric.Technical report lcsr-tr-21
Revisiting efavirenz in the era of dolutegravir: Low-dose efavirenz, a viable alternative capable of holding its own against dolutegravir-based regimens
No full textBackground: First-line dual NRTI + NNRTI-based ART has shown good virological effectiveness; however, toxicity is common and is often the most common reason for modification of first-line ART.
Aims: The purpose of this study is to revisit low-dose efavirenz (EFV) in the era of dolutegravir (DTG) by investigating anti-retroviral therapy (ART) switch strategies for outcomes of virological effectiveness and safety in virologically suppressed Indian persons living with HIV (PLH) on first-line dual nucleoside reverse transcriptase inhibitors (NRTI) + non-NRTI (NNRTI)-based ART.
Methods: A phase-IV comparative study of consecutive cases who switched their first-line NNRTI-based ART to either EFV-400 or DTG with a dual NRTI backbone between October 2020 to December 2021 and underwent at least 48 weeks of follow-up. The study is a non-randomised trial, wherein ART regimens were based on physician choice, patient preference and drug availability.
Results: A total of 102 [DTG arm: 52; EFV-400 arm: 50; intention-to-treat (ITT) population] participants met the inclusion criteria. At 48-week follow-up, virological failure was not observed in either arm. Virological suppression to < 200 cp/mL was attained in 97.9% (n = 48/49; 95% confidence interval [CI]: 89.1–99.9) and 95.9% (n = 47/49; 95% CI: 86.02–99.5) of patients, respectively, in the DTG and-EFV-400 arm (ITT-populations). There was no significant difference in mean change from baseline in body weight and body mass index between DTG and-EFV-400 arms. The proportion of patients who gained ≥ 10% of their baseline body weight at 24 weeks of exposure to DTG was 16% (n = 8, 95% CI: 5.8 to 26.2) and that to EFV-400 was 10% (n = 5, 95% CI: 1.7 to 18.3) with a difference in proportions: 6.0% (95% CI: −7.1–19.1)]. There was a significant decrease at 24 weeks in mean fasting levels of lipid fractions in the DTG arm as compared to EFV-400 [total cholesterol: − 24.3 mg/dL, 95% CI: −35.2 to − 13.3 vs. −6.9 mg/dL, 95% CI: −17.9–4.1 (P = 0.029) and triglycerides:−35.9 mg/dL, 95% CI: −60.9 to − 10.9 vs. 8.6 mg/dL, 95% CI: −16.6 to 33.8 (P = 0.014)]. Adverse events (AEs) of any grade including laboratory derangements to DTG were experienced by 6% (n = 3, 95% CI: −0.6 to 12.6) and that to EFV-400 by 8% (n = 4, 95% CI: 0.5 to 15.5) with a difference in proportions: 2.0% (95% CI: −7.9 to 11.9). Grades 3–4-AE occurred in two patients, both in the EFV-400 arm. Central nervous system AEs were not observed in the DTG arm and occurred in two patients in the EFV-400 arm. Two patients in the EFV-400 arm discontinued the regimen due to AEs.
Conclusion: Both DTG and EFV-400-based first-line ART show good virological effectiveness and safety profiles in patients who are virologically suppressed on dual NRTI + NNRTI-based first-line ART
Interactive machine learning for complex graphics selection
No full textThesis: M. Eng., Massachusetts Institute of Technology, Department of Electrical Engineering and Computer Science, 2016.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 89-91).Modern vector graphics editors support the creation of a wonderful variety of complex designs and artwork. Users produce highly realistic illustrations, stylized representational art, even nuanced data visualizations. In light of these complex graphics, selections, representations of sets of objects that users want to manipulate, become more complex as well. Direct manipulation tools that artists and designers find accessible and useful for editing graphics such as logos and icons do not have the same applicability in these more complex cases. Given that selection is the first step for nearly all editing in graphics, it is important to enable artists and designers to express these complex selections. This thesis explores the use of interactive machine learning techniques to improve direct selection interfaces. To investigate this approach, I created Insight, an interactive machine learning selection tool for making a relevant class of complex selections: visually similar objects. To make a selection, users iteratively provide examples of selection objects by clicking on them in the graphic. Insight infers a selection from the examples at each step, allowing users to quickly understand results of actions and reactively shape the complex selection. The interaction resembles the direct manipulation interactions artists and designers have found accessible, while helping express complex selections by inferring many parameter changes from simple actions. I evaluated Insight in a user study of digital designers and artists, finding that Insight enabled users to effectively and easily make complex selections not supported by state-of-the-art vector graphics editors. My results contribute to existing work by both indicating a useful approach for providing complex representation access to artists and designers, and showing a new application for interactive machine learning.by Sumit Gogia.M. Eng
Online regulations of low order systems under bounded control
No full textTime-optimal solutions provide us with the fastest means to regulate a system in presence of input constraints. This advantage of time-optimal control solutions is offset by the fact that their real-time implementation involves computationally intensive iterative techniques. Moreover, time-optimal controls depend on the initial state and have to be recalculated for even the slightest perturbation. Clearly time-optimal controls are not good candidates for online regulation. Consequently, the search for alternatives to time-optimal solutions is a very active area of research. The work described here is inspired by the simplicity of optimal-aim concept. The "optimal-aim strategies" provide online regulation in presence of bounded inputs with minimal computational effort. These are based purely on state-space geometry of the plant and are inherently adaptive in nature. Optimal-aim techniques involve aiming of trajectory derivative (or the state velocity vector) so as to approach the equilibrium state in the best possible manner. This thesis documents the efforts to develop an online regulation algorithm for systems with input constraints. Through a number of hypotheses focussed on trying to reproduce the exact time-optimal solution, the diffculty associated with this task is demonstrated. A modification of optimal-aim concept is employed to develop a novel regulation algorithm. In this algorithm, aim directions are chosen in a special manner to generate the time-optimal control approximately. The control scheme thus developed is shown to be globally stabilizing for systems having eigenvalues in the CLHP (closed left half-plane). It is expected that this method or its modifications can be extended to higher dimensional systems as a part of future research. An alternative control algorithm involving a simple state-space aiming concept is also developed and discussed
Perception of primary school teachers about the quality of pre-school education provided by anganwadis
No full textA couple of months ago, I was reading about Early
Childhood Care and Education (ECCE)in India and
came across the new drafts for the policy
framework, quality standards and curriculum for
pre-school education by the Ministry of Women and
Child Development (MWCD). One of the aims of
ECCE is to make a child school ready by providing
emergent literacy and math skills and I started
wondering about how do we know if a child is
actually school ready or not? So, I decided to meet
with a few primary school teachers to understand if
they thought that the children who came to their
schools after attending anganwadis were actually
school ready, and if not what did they expect of
children who attended anganwadis and what
suggestions did they have for improving the quality
of pre-school education provided by anganwadis
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