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Search Results: 1 - 10 of 820 matches for " Divya Upadhyay? "
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Web Browsing Behaviors Based Age Detection
Misha Kakkar,Divya Upadhyay
International Journal of Soft Computing & Engineering , 2013,
Abstract: Users basic attributes like age, gender location etc… plays an essential role in today’s web applications. Previous research shows that there is relationship between users’ browsing behavior and their basic characteristics. In this paper we made an approach to detect a user’s age depending on his web browsing history. The user’s web browsing behaviors is treated as a variable to propagate age information between different users. Artificial neural network tool is used for this purpose. Uses are divided into two different categories of adult and youngsters. The result is 93.7% accurate.
An Analysis for Black Hole Attack in AODV Protocol and Its Solution
Rahul Sharma,Naveen Dahiya,Divya Upadhyay
International Journal of Computer Science and Mobile Computing , 2013,
Abstract: Security is an essential requirement in mobile ad hoc networks to provide protectedcommunication between mobile nodes. MANETs are vulnerable to various attacks; black hole is one of thepossible attacks. Black hole is a type of routing attack where a malicious node advertise itself as having theshortest path to all nodes in the environment by sending fake route reply.We attempt to focus on analysing and improving the security of one of the popular routing protocol forMANETS viz. the Ad hoc On Demand Distance Vector (AODV) routing protocol. Our focus specifically, ison ensuring the security against the Black hole Attacks. We propose modifications to the AODV protocol andjustify the solution with appropriate implementation.
Improving Content Based Image Retrieval using Scale Invariant Feature Transform
Mamta Kamath,Disha Punjabi,Tejal Sabnis,Divya Upadhyay
International Journal of Engineering and Advanced Technology , 2012,
Abstract: Content-Based Image Retrieval (CBIR) is achallenging task. Common approaches use only low-level features.Notwithstanding, such CBIR solutions fail on capturing some localfeatures representing the details and nuances of scenes. Manytechniques in image processing and computer vision can capturethese scene semantics. Among them, the Scale Invariant FeaturesTransform (SIFT) has been widely used in a lot of applications.This approach relies on the choice of several parameters whichdirectly impact its effectiveness when applied to retrieve images. Inthis paper, we attempt to evaluate the application of the SIFT torefine CBIR.
Role of Optimism Bias and Risk Attitude on Investment Behaviour  [PDF]
Divya Gakhar
Theoretical Economics Letters (TEL) , 2019, DOI: 10.4236/tel.2019.94056
Abstract:

Purpose: The study undertakes to identify individual characteristics and their investment pattern. The individual characteristics include MBTI personality scores, risk taking behaviour, biases and investor demographics. Data and Methodology: A structured questionnaire was administered on 117 respondents in India. The questions were related to demographic variables, optimism bias, investment pattern and MBTI (Myers-Briggs Type Indicator®) personality assessment. The results were analysed using chi-square and ANOVA. Findings: The results show that presence of optimism bias in investors is influenced by marital status, nature of employment and work experience of investors. The Indian investors are majorly balanced or conservative out of the total sample in terms of risk taking behaviour. Risk taking attitude is affected by personality of individuals. Investment in high risk instruments is different among males and females, various age groups, marital status, and work place activity. Investment in medium risk instruments significantly differ for work experience on gender basis. Investment in low risk instruments does not differ for demographic variables of investors as all investors invest equally in safe investment mode. MBTI personality type is a less significant variable which directly affects investment patterns of Indian investors. The study can be useful for portfolio managers, investment advisors who can use it for designing investment portfolios and products for their clients based on their demographic, and behavioural profiling. Originality: This study identifies relationship between investment pattern, behavioural biases and demographic characteristics of Indian investors. MBTI personality assessment is one new dimension which is less researched in studying investment behaviour in Indian context.

Hospital-Acquired Anaemia Secondary to Phlebotomy in Elderly Patients  [PDF]
Divya Tiwari, Caroline Rance
Advances in Aging Research (AAR) , 2014, DOI: 10.4236/aar.2014.32012
Abstract:


Introduction: Anaemia contributes to increased morbidity and mortality in hospitalised patients, yet unnecessary blood tests from inpatients may actually induce a “hospital acquired anaemia” (HAA). This study examines the incidence of phlebotomy-induced anaemia during a hospital admission. Methods: Patients admitted to the Royal Bournemouth Hospital between 2009 and 2011 for a period of more than two weeks were identified. Those with normal haemoglobins on admission (Hb > 130 g/dL in men; Hb > 120 g/dL in women) were selected to be included in the study. One hundred and sixty two patients were randomly selected from this group and their admission and discharge haemoglobin was recorded, and the change in Hb was calculated. The number of blood tests taken during admission was calculated from each patient from which volume of blood lost was determined. Age, sex and co-morbidities, bleeding complications and blood transfusions were noted. T-test for unequal variance was used for analysis. Results: Of the 162 patients, 69 (42.5%) developed a HAA (defined as haemoglobin drop from normal to <110 g/dL). The average number of blood tests taken in the anaemia group was 37, compared to only 23 in the “no-anaemia” group. i.e. 132 mls in the anaemia group vs. only 80.2 mls in no-anaemia group. Further analysis of the anaemia group revealed that 40 patients developed a “mild anaemia” (defined as drop in Hb from normal to <110 g/dL) and 29 developed a moderate/severe anaemia (drop from a normal Hb at admission to <100 g/dL). Significantly higher volume of blood was withdrawn from this moderate/severe anaemia group compared to those that developed a mild anaemia 177.9 mls vs. 121.34 mls (p-Value 0.007, F = 0.001) 95% CI 2.08 to 9.22. Conclusion: This study suggests that patients admitted for inpatient stays of more than two weeks may be at high risk of HAA as a consequence of diagnostic blood loss. This anaemia in turn may have detrimental consequences, especially in patients with pre-existing cardio-respiratory disease. There needs to be increased awareness of the risk posed to patients as a result of diagnostic phlebotomy and further studies are required to study its impact on LOS, morbidity and mortality outcomes.

Investigation of Tolerable Laser Linewidth for Different Modulation Formats in CO-OFDM Systems  [PDF]
Divya Dhawan, Neena Gupta
Optics and Photonics Journal (OPJ) , 2017, DOI: 10.4236/opj.2017.75009
Abstract: The ideal behavior of communication system requires a single frequency carrier. In optical communication system, light is used as a carrier. Practical laser source has a finite linewidth due to variations in the frequency of operation, hence, resulting in undesired phase perturbations in the signal whereas the ideal requirement is the delta function spectral shape at the carrier frequency. The spectral shape gets broadened due to phase noise and is modeled as lorentzian shape. Linewidth is a measure of stability of laser phase noise with time. Coherent Optical Orthogonal frequency division multiplexing (CO-OFDM) along with the spectrally efficient Quadrature Amplitude Modulation (QAM) formats is emerging as one of the best solutions for future high speed fiber transmission systems. Though the coherent, receivers have advantages in terms of sensitivity and selectivity, laser phase noise is the main limitation of such systems as the laser phase noise further causes common phase rotation of all the subcarriers per symbol and also results in inter carrier interference. QAM formats are also susceptible to laser phase noise. Phase noise in coherent systems is governed by laser linewidth. Hence, it is very important to investigate the impact of laser linewidth in CO-OFDM systems. This paper investigates the tolerable laser linewidths for different QAM formats in a 40 Gbps COOFDM system.
Prediction of Effective Elastic Modulus of Biphasic Composite Materials  [PDF]
Anupama Upadhyay, Ramvir Singh
Modern Mechanical Engineering (MME) , 2012, DOI: 10.4236/mme.2012.21002
Abstract: Two semi-empirical approaches for prediction of elastic modulus of biphasic composites have been proposed. Developed relations are for pore free matrix and pore free filler and found to depend on nonlinear contribution of volume fraction of constituents as well as ratio of elastic properties of individual phases. These relations are applied for the calculation of effective elastic modulus mainly for Al2O3-NiAl, SiC-Al, Alumina-Zirconia, Al-Al2O3, W-glass and Flax-Resin composite materials. Theoretical predictions using developed relations are compared with experimental data. It is found that the predicted values of effective elastic modulus using modified relations are quite close to the experimental results.
Single-Channel Speech Enhancement Using Critical-Band Rate Scale Based Improved Multi-Band Spectral Subtraction  [PDF]
Navneet Upadhyay, Abhijit Karmakar
Journal of Signal and Information Processing (JSIP) , 2013, DOI: 10.4236/jsip.2013.43040
Abstract:

This paper addresses the problem of single-channel speech enhancement in the adverse environment. The critical-band rate scale based on improved multi-band spectral subtraction is investigated in this study for enhancement of single-channel speech. In this work, the whole speech spectrum is divided into different non-uniformly spaced frequency bands in accordance with the critical-band rate scale of the psycho-acoustic model and the spectral over-subtraction is carried-out separately in each band. In addition, for the estimation of the noise from each band, the adaptive noise estimation approach is used and does not require explicit speech silence detection. The noise is estimated and updated by adaptively smoothing the noisy signal power in each band. The smoothing parameter is controlled by a-posteriori signal-to-noise ratio (SNR). For the performance analysis of the proposed algorithm, the objective measures, such as, SNR, segmental SNR, and perceptual evaluations of the speech quality are conducted for the variety of noises at different levels of SNRs. The speech spectrogram and objective evaluations of the proposed algorithm are compared with other standard speech enhancement algorithms and proved that the musical structure of the remnant noise and background noise is better suppressed by the proposed algorithm.

A Multi-Band Speech Enhancement Algorithm Exploiting Iterative Processing for Enhancement of Single Channel Speech  [PDF]
Navneet Upadhyay, Abhijit Karmakar
Journal of Signal and Information Processing (JSIP) , 2013, DOI: 10.4236/jsip.2013.42027
Abstract:

This paper proposes a multi-band speech enhancement algorithm exploiting iterative processing for enhancement of single channel speech. In the proposed algorithm, the output of the multi-band spectral subtraction (MBSS) algorithm is used as the input signal again for next iteration process. As after the first MBSS processing step, the additive noise transforms to the remnant noise, the remnant noise needs to be further re-estimated. The proposed algorithm reduces the remnant musical noise further by iterating the enhanced output signal to the input again and performing the operation repeatedly. The newly estimated remnant noise is further used to process the next MBSS step. This procedure is iterated a small number of times. The proposed algorithm estimates noise in each iteration and spectral over-subtraction is executed independently in each band. The experiments are conducted for various types of noises. The performance of the proposed enhancement algorithm is evaluated for various types of noises at different level of SNRs using, 1) objective quality measures: signal-to-noise ratio (SNR), segmental SNR, perceptual evaluation of speech quality (PESQ); and 2) subjective quality measure: mean opinion score (MOS). The results of proposed enhancement algorithm are compared with the popular MBSS algorithm. Experimental results as well as the objective and subjective quality measurement test results confirm that the enhanced speech obtained from the proposed algorithm is more pleasant to listeners than speech enhanced by classical MBSS algorithm.

Effects of plant latex based anti-termite formulations on Indian white termite Odontotermes obesus (Isoptera: Odontotermitidae) in sub-tropical high infestation areas  [PDF]
Ravi Kant Upadhyay
Open Journal of Animal Sciences (OJAS) , 2013, DOI: 10.4236/ojas.2013.34042
Abstract: In the present investigation various bioassays were conducted to evaluate the anti-termite efficacy of plant latex based formulations to control population of Indian white termite in subtropical soil. Results reveal that crude latex, its fractions and combinatorial fractions have shown very high toxicity against O. obesus. The LD50 values for different latex fractions of 24 h were in a range of 5.0-17.613 μg/mg while combined mixtures of Calotropis procera have shown synergistic activity against termites and caused comparably high mortality with LD50 1.987-6.016 μg/mg. The mortality rate was found dose and time dependent as it was found to be increased with an increase in dose and exposure period. In olfactometry tests, C. procera latex solvent fractions have shown significant repellency at a very low dose 0.010-0.320 μg/mg. Interestingly, solvent fractions have significantly repelled large numbers of worker termites due to volatile action of active components of latex and different additives. ED50 values obtained in crude latex were 0.121 μg/mg body weights while combinatorial formulations have shown ED50 in between 0.015-0.036 μg/mg. Statistical analysis of repelled and un-repelled termites gave a low Chi-square value (X2
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