It has recently been demonstrated that black hole dynamics in a large number of dimensions D redu... more It has recently been demonstrated that black hole dynamics in a large number of dimensions D reduces to the dynamics of a codimension one membrane propagating in flat space. In this paper we define a stress tensor and charge current on this membrane and explicitly determine these currents at low orders in the expansion in 1/D. We demonstrate that dynamical membrane equations of motion derived in earlier work are simply conservation equations for our stress tensor and charge current. Through the paper we focus on solutions of the membrane equations which vary on a time scale of order unity. Even though the charge current and stress tensor are not parametrically small in such solutions, we show that the radiation sourced by the corresponding membrane currents is generically of order 1/D^D. In this regime it follows that the `near horizon' membrane degrees of freedom are decoupled from asymptotic flat space at every perturbative order in the 1/D expansion. We also define an entropy...
Online social media has become a major source of information gathering for a huge section of soci... more Online social media has become a major source of information gathering for a huge section of society. As the amount of information flows in online social media is enormous but on the other hand, the fact-checking sources are limited. This shortfall of fact-checking gives birth to the problem of misinformation and disinformation in the case of the truthfulness of facts on online social media which can have serious effects on the wellbeing of society. This problem of misconception becomes more rapid and critical when some events like the recent outbreak of Covid-19 happen when there is no or very little information is available anywhere. In this scenario, the identification of the content available online which is mostly propagated from person to person and not by any governing authority is very needed at the hour. To solve this problem, the information available online should be verified properly before being conceived by any individual. We propose a scheme to classify the online social media posts (Tweets) with the help of the BERT (Bidirectional Encoder Representations from Transformers)-based model. Also, we compared the performance of the proposed approach with the other machine learning techniques and other State of the art techniques available. The proposed model not only classifies the tweets as relevant or irrelevant, but also creates a set of topics by which one can identify a text as relevant or irrelevant to his/her need just by just matching the keywords of the topic. To accomplish this task, after the classification of the tweets, we apply a possible topic modelling approach based on latent semantic analysis and latent Dirichlet allocation methods to identify which of the topics are mostly propagated as false information.
2020 IEEE International Conference on Power Electronics, Smart Grid and Renewable Energy (PESGRE2020)
The rotor structure in synchronous reluctance motor (SyRM) doesn’t have any cage, magnets and win... more The rotor structure in synchronous reluctance motor (SyRM) doesn’t have any cage, magnets and windings resulting in a rugged, reliable and lower cost of manufacturing. The rotor construction in SyRM comprises of only barriers, which play prominent role in torque shaping, torque ripple content and power factor. The impact of the air barrier shapes on the performance of the motor is studied. The main aim of the research is to analyze the effect of flux barriers shapes on average torque, torque ripple, saturation, cross saturation and saliency ratio of the machine. In solar water pumping, the torque ripple is a serious concern, especially in submersible pumps. Moreover, the power factor is a prime aspect in deciding the rating of variable frequency drive for Maximum power point tracking (MPPT). A 4pole, 100Hz synchronous reluctance motor with 24 stator slots is chosen for study and analysis is done using finite element analysis (FEA).
Optical coherence tomography (OCT), a biomedical diagnostic-imaging technique, is currently trans... more Optical coherence tomography (OCT), a biomedical diagnostic-imaging technique, is currently transitioning from the research laboratory into clinical practice.1 Providing micrometer-scale resolution over millimeter-scale fields of view, OCT is the opti-cal analog of ultrasound. It ...
2018 Second International Conference on Advances in Electronics, Computers and Communications (ICAECC), 2018
A modified bulk degeneration technique for source-degenerated OTAs is proposed in this paper. The... more A modified bulk degeneration technique for source-degenerated OTAs is proposed in this paper. The approach employs drain voltage division and cross-coupling the resultant voltage to the bulk terminal of differential pair which reduces third harmonic distortion (HD3). Simulations are carried on 0.18 $\mu {\rm m}$ process with 1.8 V power supply which shows that (HD3) is decreased by 14 dB (for frequencies of 100 KHz) as compared to previously reported bulk degenerated transconductors. An added advantage is the variation of DC transconductance using the resistance ratio of the voltage divider circuit which offers the tunability in the transconductance.
This paper deals with three phase induction motor drive (IMD) using field oriented control (FOC) ... more This paper deals with three phase induction motor drive (IMD) using field oriented control (FOC) for water pumping fed by solar PV array. It is includes solar PV array, a voltage source inverter (VSI) and a motor-pump assembly. The aim is to extract maximum power from the PV array as well as control the motor in rotor reference frame. The soft start feature is used for the initial start-up of pump. For extraction of maximum power, an adaptive incremental conductance method is used. The tangent of the power versus voltage curve is tracked for good estimation of maximum power point(MPP). The vector control provides smooth startup and starting current is reduced. Proposed system is designed and simulated in MATLAB/Simulink software. Simulated results are demonstrated for verification of the system.
2020 IEEE 9th Power India International Conference (PIICON), 2020
The bridgeless isolated power factor corrected (PFC) SEPIC converter based ceiling fan with DC li... more The bridgeless isolated power factor corrected (PFC) SEPIC converter based ceiling fan with DC link voltage of 48V, shows the better power quality and less power consumption. It consists of an electromagnetic interference (EMI) filter, high frequency isolation transformer in series with a voltage source inverter and a permanent magnet brushless DC (PMBLDC) motor. This topology is designed in discontinuous inductor current mode (DCIM) of operation with input power of 30W. This ceiling fan is taking power one third of a single phase induction motor. The power quality performances are found good for this topology based ceiling fan. This topology for the ceiling fan is simulated with simple voltage follower control technique. To control the speed of PMBLDC motor, DC link voltage is sensed and it varies up to 48V. The turn’s ratio of high frequency transformer and inductor are selected such a manner that the switch stress of the converter switches should be minimum. The MATLAB simulation...
2020 IEEE International Conference on Power Electronics, Drives and Energy Systems (PEDES), 2020
Permanent magnet brushless DC (PMBLDC) motor-based ceiling fans offer an efficient option to the ... more Permanent magnet brushless DC (PMBLDC) motor-based ceiling fans offer an efficient option to the widely-used single phase induction motor (SPIM) based ceiling fans. A PMBLDCM ceiling fan special features over a SPIM ceiling fan motor include lower input power consumption for the same air-delivery, higher efficiency, efficient speed control, and smaller form factor. This paper deals with the detailed design procedure of a three-phase exterior rotor permanent magnet brushless DC motor for ceiling fan application. The complete procedure is not yet reported for ceiling fans. The analytical design procedure is more computationally efficient than FEA and provides multiple designs covering a wide variety of objectives faster. Detailed analytical design procedure covering the initial sizing, stator, rotor design, and performance assessment is given for a 16-pole, 35 W, 350 rpm surface mounted PMBLDC motor. The results from the analytical design procedure are then validated using 2D FEA soft...
International Archives of BioMedical and Clinical Research, 2018
Background: This study was designed to determine the microbiologic profile and Antibiotics Sensit... more Background: This study was designed to determine the microbiologic profile and Antibiotics Sensitivity in Children presenting with UTI. Materials & Methods: This hospital based prospective study was conducted in 28 patients Patients from 2 months to 12 years were admitted to the pediatric ward and visited in outpatient department (OPD) with diagnosis of UTI based on history with routine and microscopic examination of urine were considered for this study. The UTI investigation protocol recommended ultrasound, voiding cystourethrography (VCUG), and DMSA scan. Clinical and laboratory parameters at the index infection, including highest measured temperature, highest C-reactive protein (CRP), bacterial findings, and the number of febrile recurrences, were recorded. Results: Fever was the most common symptom accounting for 76.4% of patients with nausea and vomiting (42.8%), dysuria (53.6%), abdominal pain (57.1%) and anorexia (46.4%). Urine analysis was done in all suspected cases of UTI....
When data is plentiful, the loss achieved by well-trained neural networks scales as a power-law $... more When data is plentiful, the loss achieved by well-trained neural networks scales as a power-law $L \propto N^{-\alpha}$ in the number of network parameters $N$. This empirical scaling law holds for a wide variety of data modalities, and may persist over many orders of magnitude. The scaling law can be explained if neural models are effectively just performing regression on a data manifold of intrinsic dimension $d$. This simple theory predicts that the scaling exponents $\alpha \approx 4/d$ for cross-entropy and mean-squared error losses. We confirm the theory by independently measuring the intrinsic dimension and the scaling exponents in a teacher/student framework, where we can study a variety of $d$ and $\alpha$ by dialing the properties of random teacher networks. We also test the theory with CNN image classifiers on several datasets and with GPT-type language models.
Materials and Methods: Selection of population: The school children in age group of 6-18 years fr... more Materials and Methods: Selection of population: The school children in age group of 6-18 years from both the sexes were screened from SGRR schools of different locations at Dehradun, after taking approval from principal and the parents. Each child was given a reference number and a questioner performa was given on prior day to the class teacher to fill it by parents and teachers them self. Next day the enrolled students were examined in the outpatient department by a specialist and complete the performa. Results: In the present study of 1271 children, 59.5% were boys and 40.5% were girls. It was observed that children of age group 11-14 years were maximum in both the sexes that is 748 (58.9%). Among various disease patterns in present study, the most prevalent disease was dental caries 24.86% followed by fluorosis 13.06% and pallor 12.67%. All diseases were more prevalent in boys than girls (P 0.05). In the present study, poor oral hygiene is a significant health problem in school g...
we propose a Correlation approach for fusion of images gathered by different wireless sensors on ... more we propose a Correlation approach for fusion of images gathered by different wireless sensors on the basis of Mark Pearson’s correlation theory. In this paper we present a comparison of previously available and applied correlation approaches. Our method is based on calculating the intensities of the pixels of the image and its gray scale equivalent.
The ceiling fans are the essential commodity in residential and commercial infrastructure. The co... more The ceiling fans are the essential commodity in residential and commercial infrastructure. The conventional ceiling fans are neglected for ages for improvement in efficiency. Presently, there is a thrust for energy efficiency from Indian and all the governments around the world. In this paper, the design for improvement in the efficiency of ceiling fan single-phase induction motor (SPIM) is presented for pacing up with the revised Indian Standard (374) and star ratings by BEE, India. The transient mechanical finite element simulation-based validation of the 5 star rated commercial fans, is conducted, and the design is improved in several stages considering the manufacturability and Indian market acceptability. The improved designs are prototyped, and the feedback from the prototypes is used for further design improvement. The challenges and the manufacturing issues are presented for the energy-efficient design of the ceiling fan motor. The experimental performance of the prototypes ...
Background : In India 34.3% of the total population is constituted by the most vulnerable segment... more Background : In India 34.3% of the total population is constituted by the most vulnerable segment of our society i.e. infants and children. Malnutrition, respiratory and diarrhoeal diseases are three main scourges of the children but the great devils hovering upon them are lack of proper treatment and management. The present study was conducted to find out the morbidity pattern of our vulnerable children. Aims and Objectives : 1. To find out the prevalence of critically ill children admitted in the hospital. 2. To find out the morbidity pattern of critically ill children admitted in the child intensive therapy unit, in a hospital. Research Question : What is the epidemiological pattern of morbidity in critically ill children of age 1 month to 12 years? Study Design : Cross-sectional Study. Study Participants : All critically ill children coming to the emergency unit of the hospital during study period. Statistical Analysis : Simple percent and proportions, Chi square test.
The test loss of well-trained neural networks often follows precise power-law scaling relations w... more The test loss of well-trained neural networks often follows precise power-law scaling relations with either the size of the training dataset or the number of parameters in the network. We propose a theory that explains and connects these scaling laws. We identify variance-limited and resolution-limited scaling behavior for both dataset and model size, for a total of four scaling regimes. The variance-limited scaling follows simply from the existence of a well-behaved infinite data or infinite width limit, while the resolution-limited regime can be explained by positing that models are effectively resolving a smooth data manifold. In the large width limit, this can be equivalently obtained from the spectrum of certain kernels, and we present evidence that large width and large dataset resolution-limited scaling exponents are related by a duality. We exhibit all four scaling regimes in the controlled setting of large random feature and pretrained models and test the predictions empiri...
Analysis of ESG data along with financial parameters from 34 stock market indices across the glob... more Analysis of ESG data along with financial parameters from 34 stock market indices across the globe. This work is done to study the effect of ESG score variables on the prediction of financial growth indicators for the top publicly traded companies of the world. This aims to give socially conscious investors a better view when investing in companies while looking at the broader sustainability that an organization practices while operating.
It has recently been demonstrated that black hole dynamics in a large number of dimensions D redu... more It has recently been demonstrated that black hole dynamics in a large number of dimensions D reduces to the dynamics of a codimension one membrane propagating in flat space. In this paper we define a stress tensor and charge current on this membrane and explicitly determine these currents at low orders in the expansion in 1/D. We demonstrate that dynamical membrane equations of motion derived in earlier work are simply conservation equations for our stress tensor and charge current. Through the paper we focus on solutions of the membrane equations which vary on a time scale of order unity. Even though the charge current and stress tensor are not parametrically small in such solutions, we show that the radiation sourced by the corresponding membrane currents is generically of order 1/D^D. In this regime it follows that the `near horizon' membrane degrees of freedom are decoupled from asymptotic flat space at every perturbative order in the 1/D expansion. We also define an entropy...
Online social media has become a major source of information gathering for a huge section of soci... more Online social media has become a major source of information gathering for a huge section of society. As the amount of information flows in online social media is enormous but on the other hand, the fact-checking sources are limited. This shortfall of fact-checking gives birth to the problem of misinformation and disinformation in the case of the truthfulness of facts on online social media which can have serious effects on the wellbeing of society. This problem of misconception becomes more rapid and critical when some events like the recent outbreak of Covid-19 happen when there is no or very little information is available anywhere. In this scenario, the identification of the content available online which is mostly propagated from person to person and not by any governing authority is very needed at the hour. To solve this problem, the information available online should be verified properly before being conceived by any individual. We propose a scheme to classify the online social media posts (Tweets) with the help of the BERT (Bidirectional Encoder Representations from Transformers)-based model. Also, we compared the performance of the proposed approach with the other machine learning techniques and other State of the art techniques available. The proposed model not only classifies the tweets as relevant or irrelevant, but also creates a set of topics by which one can identify a text as relevant or irrelevant to his/her need just by just matching the keywords of the topic. To accomplish this task, after the classification of the tweets, we apply a possible topic modelling approach based on latent semantic analysis and latent Dirichlet allocation methods to identify which of the topics are mostly propagated as false information.
2020 IEEE International Conference on Power Electronics, Smart Grid and Renewable Energy (PESGRE2020)
The rotor structure in synchronous reluctance motor (SyRM) doesn’t have any cage, magnets and win... more The rotor structure in synchronous reluctance motor (SyRM) doesn’t have any cage, magnets and windings resulting in a rugged, reliable and lower cost of manufacturing. The rotor construction in SyRM comprises of only barriers, which play prominent role in torque shaping, torque ripple content and power factor. The impact of the air barrier shapes on the performance of the motor is studied. The main aim of the research is to analyze the effect of flux barriers shapes on average torque, torque ripple, saturation, cross saturation and saliency ratio of the machine. In solar water pumping, the torque ripple is a serious concern, especially in submersible pumps. Moreover, the power factor is a prime aspect in deciding the rating of variable frequency drive for Maximum power point tracking (MPPT). A 4pole, 100Hz synchronous reluctance motor with 24 stator slots is chosen for study and analysis is done using finite element analysis (FEA).
Optical coherence tomography (OCT), a biomedical diagnostic-imaging technique, is currently trans... more Optical coherence tomography (OCT), a biomedical diagnostic-imaging technique, is currently transitioning from the research laboratory into clinical practice.1 Providing micrometer-scale resolution over millimeter-scale fields of view, OCT is the opti-cal analog of ultrasound. It ...
2018 Second International Conference on Advances in Electronics, Computers and Communications (ICAECC), 2018
A modified bulk degeneration technique for source-degenerated OTAs is proposed in this paper. The... more A modified bulk degeneration technique for source-degenerated OTAs is proposed in this paper. The approach employs drain voltage division and cross-coupling the resultant voltage to the bulk terminal of differential pair which reduces third harmonic distortion (HD3). Simulations are carried on 0.18 $\mu {\rm m}$ process with 1.8 V power supply which shows that (HD3) is decreased by 14 dB (for frequencies of 100 KHz) as compared to previously reported bulk degenerated transconductors. An added advantage is the variation of DC transconductance using the resistance ratio of the voltage divider circuit which offers the tunability in the transconductance.
This paper deals with three phase induction motor drive (IMD) using field oriented control (FOC) ... more This paper deals with three phase induction motor drive (IMD) using field oriented control (FOC) for water pumping fed by solar PV array. It is includes solar PV array, a voltage source inverter (VSI) and a motor-pump assembly. The aim is to extract maximum power from the PV array as well as control the motor in rotor reference frame. The soft start feature is used for the initial start-up of pump. For extraction of maximum power, an adaptive incremental conductance method is used. The tangent of the power versus voltage curve is tracked for good estimation of maximum power point(MPP). The vector control provides smooth startup and starting current is reduced. Proposed system is designed and simulated in MATLAB/Simulink software. Simulated results are demonstrated for verification of the system.
2020 IEEE 9th Power India International Conference (PIICON), 2020
The bridgeless isolated power factor corrected (PFC) SEPIC converter based ceiling fan with DC li... more The bridgeless isolated power factor corrected (PFC) SEPIC converter based ceiling fan with DC link voltage of 48V, shows the better power quality and less power consumption. It consists of an electromagnetic interference (EMI) filter, high frequency isolation transformer in series with a voltage source inverter and a permanent magnet brushless DC (PMBLDC) motor. This topology is designed in discontinuous inductor current mode (DCIM) of operation with input power of 30W. This ceiling fan is taking power one third of a single phase induction motor. The power quality performances are found good for this topology based ceiling fan. This topology for the ceiling fan is simulated with simple voltage follower control technique. To control the speed of PMBLDC motor, DC link voltage is sensed and it varies up to 48V. The turn’s ratio of high frequency transformer and inductor are selected such a manner that the switch stress of the converter switches should be minimum. The MATLAB simulation...
2020 IEEE International Conference on Power Electronics, Drives and Energy Systems (PEDES), 2020
Permanent magnet brushless DC (PMBLDC) motor-based ceiling fans offer an efficient option to the ... more Permanent magnet brushless DC (PMBLDC) motor-based ceiling fans offer an efficient option to the widely-used single phase induction motor (SPIM) based ceiling fans. A PMBLDCM ceiling fan special features over a SPIM ceiling fan motor include lower input power consumption for the same air-delivery, higher efficiency, efficient speed control, and smaller form factor. This paper deals with the detailed design procedure of a three-phase exterior rotor permanent magnet brushless DC motor for ceiling fan application. The complete procedure is not yet reported for ceiling fans. The analytical design procedure is more computationally efficient than FEA and provides multiple designs covering a wide variety of objectives faster. Detailed analytical design procedure covering the initial sizing, stator, rotor design, and performance assessment is given for a 16-pole, 35 W, 350 rpm surface mounted PMBLDC motor. The results from the analytical design procedure are then validated using 2D FEA soft...
International Archives of BioMedical and Clinical Research, 2018
Background: This study was designed to determine the microbiologic profile and Antibiotics Sensit... more Background: This study was designed to determine the microbiologic profile and Antibiotics Sensitivity in Children presenting with UTI. Materials & Methods: This hospital based prospective study was conducted in 28 patients Patients from 2 months to 12 years were admitted to the pediatric ward and visited in outpatient department (OPD) with diagnosis of UTI based on history with routine and microscopic examination of urine were considered for this study. The UTI investigation protocol recommended ultrasound, voiding cystourethrography (VCUG), and DMSA scan. Clinical and laboratory parameters at the index infection, including highest measured temperature, highest C-reactive protein (CRP), bacterial findings, and the number of febrile recurrences, were recorded. Results: Fever was the most common symptom accounting for 76.4% of patients with nausea and vomiting (42.8%), dysuria (53.6%), abdominal pain (57.1%) and anorexia (46.4%). Urine analysis was done in all suspected cases of UTI....
When data is plentiful, the loss achieved by well-trained neural networks scales as a power-law $... more When data is plentiful, the loss achieved by well-trained neural networks scales as a power-law $L \propto N^{-\alpha}$ in the number of network parameters $N$. This empirical scaling law holds for a wide variety of data modalities, and may persist over many orders of magnitude. The scaling law can be explained if neural models are effectively just performing regression on a data manifold of intrinsic dimension $d$. This simple theory predicts that the scaling exponents $\alpha \approx 4/d$ for cross-entropy and mean-squared error losses. We confirm the theory by independently measuring the intrinsic dimension and the scaling exponents in a teacher/student framework, where we can study a variety of $d$ and $\alpha$ by dialing the properties of random teacher networks. We also test the theory with CNN image classifiers on several datasets and with GPT-type language models.
Materials and Methods: Selection of population: The school children in age group of 6-18 years fr... more Materials and Methods: Selection of population: The school children in age group of 6-18 years from both the sexes were screened from SGRR schools of different locations at Dehradun, after taking approval from principal and the parents. Each child was given a reference number and a questioner performa was given on prior day to the class teacher to fill it by parents and teachers them self. Next day the enrolled students were examined in the outpatient department by a specialist and complete the performa. Results: In the present study of 1271 children, 59.5% were boys and 40.5% were girls. It was observed that children of age group 11-14 years were maximum in both the sexes that is 748 (58.9%). Among various disease patterns in present study, the most prevalent disease was dental caries 24.86% followed by fluorosis 13.06% and pallor 12.67%. All diseases were more prevalent in boys than girls (P 0.05). In the present study, poor oral hygiene is a significant health problem in school g...
we propose a Correlation approach for fusion of images gathered by different wireless sensors on ... more we propose a Correlation approach for fusion of images gathered by different wireless sensors on the basis of Mark Pearson’s correlation theory. In this paper we present a comparison of previously available and applied correlation approaches. Our method is based on calculating the intensities of the pixels of the image and its gray scale equivalent.
The ceiling fans are the essential commodity in residential and commercial infrastructure. The co... more The ceiling fans are the essential commodity in residential and commercial infrastructure. The conventional ceiling fans are neglected for ages for improvement in efficiency. Presently, there is a thrust for energy efficiency from Indian and all the governments around the world. In this paper, the design for improvement in the efficiency of ceiling fan single-phase induction motor (SPIM) is presented for pacing up with the revised Indian Standard (374) and star ratings by BEE, India. The transient mechanical finite element simulation-based validation of the 5 star rated commercial fans, is conducted, and the design is improved in several stages considering the manufacturability and Indian market acceptability. The improved designs are prototyped, and the feedback from the prototypes is used for further design improvement. The challenges and the manufacturing issues are presented for the energy-efficient design of the ceiling fan motor. The experimental performance of the prototypes ...
Background : In India 34.3% of the total population is constituted by the most vulnerable segment... more Background : In India 34.3% of the total population is constituted by the most vulnerable segment of our society i.e. infants and children. Malnutrition, respiratory and diarrhoeal diseases are three main scourges of the children but the great devils hovering upon them are lack of proper treatment and management. The present study was conducted to find out the morbidity pattern of our vulnerable children. Aims and Objectives : 1. To find out the prevalence of critically ill children admitted in the hospital. 2. To find out the morbidity pattern of critically ill children admitted in the child intensive therapy unit, in a hospital. Research Question : What is the epidemiological pattern of morbidity in critically ill children of age 1 month to 12 years? Study Design : Cross-sectional Study. Study Participants : All critically ill children coming to the emergency unit of the hospital during study period. Statistical Analysis : Simple percent and proportions, Chi square test.
The test loss of well-trained neural networks often follows precise power-law scaling relations w... more The test loss of well-trained neural networks often follows precise power-law scaling relations with either the size of the training dataset or the number of parameters in the network. We propose a theory that explains and connects these scaling laws. We identify variance-limited and resolution-limited scaling behavior for both dataset and model size, for a total of four scaling regimes. The variance-limited scaling follows simply from the existence of a well-behaved infinite data or infinite width limit, while the resolution-limited regime can be explained by positing that models are effectively resolving a smooth data manifold. In the large width limit, this can be equivalently obtained from the spectrum of certain kernels, and we present evidence that large width and large dataset resolution-limited scaling exponents are related by a duality. We exhibit all four scaling regimes in the controlled setting of large random feature and pretrained models and test the predictions empiri...
Analysis of ESG data along with financial parameters from 34 stock market indices across the glob... more Analysis of ESG data along with financial parameters from 34 stock market indices across the globe. This work is done to study the effect of ESG score variables on the prediction of financial growth indicators for the top publicly traded companies of the world. This aims to give socially conscious investors a better view when investing in companies while looking at the broader sustainability that an organization practices while operating.
Uploads
Papers by Utkarsh Sharma