Comparison of Classification Techniques to Detect Snow Images

Sankalp Kallakuri,Jitesh K. Singh,Roh Seung Hyun 한국자동차공학회 2011 한국자동차공학회 학술대회 및 전시회 Vol.2011 No.11

Modern day vehicles have several safety and convenience features. One such feature is weather detection. Detection of snow using a camera in a vehicle is one of the means to detect the snow. Thus there is a need to classify images taken from an onboard camera into images with snow and images without snow. Based on such classification the electronic control unit of the vehicle can automatically activate wipers and head lights of the vehicle in an appropriate manner to handle the inclement weather. This classification has been attempted using Support Vector Machines and K Nearest Neighbor Classifiers. This paper presents a comparison of the above mentioned methods in terms of their accuracy and their False Acceptance Rates (FAR). The feature based on which the image classification has been done is the histogram of the image.

Role of redox iron towards an increase in mortality among patients: a systemic review and meta-analysis

Sankalp Sharma 대한혈액학회 2019 Blood Research Vol.54 No.2

An increase in biochemical concentrations of non-transferrin bound iron (NTBI) within the patients with an increase in serum iron concentration was evaluated with the following objectives: (a) Iron overloading diseases/conditions with free radicle form of ‘iron con-taining’ reactive oxygen species (ROS) and its imbalance mediated mortality, and (b) Intervention with iron containing drugs in context to increased redox iron concentration and treatment induced mortality. Literature search was done within Pubmed and co-chrane review articles. The Redox iron levels are increased during dys-erythropoiesis and among transfusion recipient population and are responsive to iron-chelation therapy. Near expiry ‘stored blood units’ show a significant rise in the ROS level. Iron mediated ROS damage may be estimated by the serum antioxidant level, and show reduction in toxicity with high antioxidant, low pro-oxidant levels. Iron drug therapy causes a sig-nificant increase in NTBI and labile iron levels. Hospitalized patients on iron therapy how-ever show a lower mortality rate. Serum ferritin is a mortality indicator among the high-dose iron therapy and transfusion dependent population. The cumulative difference of pre-chelation to post chelation ROS iron level was 0.97 (0.62; 1.32; N=261) among the transfusion dependent subjects and 2.89 (1.81‒3.98; N=130) in the post iron therapy ‘iron ROS’ group. In conclusion, iron mediated mortality may not be mediated by redox iron among multi-transfused and iron overloaded patients.

A Differential Hall Effect Based Pressure Sensor

Yenuganti Sujan,Sankalp Paliwal 대한전기학회 2021 Journal of Electrical Engineering & Technology Vol.16 No.2

This paper presents the design and simulation of a pressure sensor integrated with two identical hall eff ect sensors and permanent magnets arranged in a diff erential confi guration for measuring pressure in the range of 0–20 bar. The sensor uses the defl ection of a circular diaphragm with a simple rigid mechanical structure to convert the applied pressure to a differential hall voltage output. A complete analytical modelling was carried out by assuming the rigid mechanical structure as a central circular boss structure on the circular diaphragm. Numerical simulations were also carried out in COMSOL Multiphysics FEM tool to support the analytical results. Before going for actual fabrication, the optimum sensor dimensions were also fi xed from both analytical modelling and numerical simulation analysis. The sensor was planned to be fabricated completely using diff erent grades of stainless steel and hence can be used in high temperature and corrosive environments. The fabricated sensor can be of low cost, self-packaged and the diff erential arrangement helps in compensating for any ambient temperature variations.

Positioning errors and quality assessment in panoramic radiography

Dhillon, Manu,Raju, Srinivasa M.,Verma, Sankalp,Tomar, Divya,Mohan, Raviprakash S.,Lakhanpal, Manisha,Krishnamoorthy, Bhuvana Korean Academy of Oral and Maxillofacial Radiology 2012 Imaging Science in Dentistry Vol.42 No.4

Purpose: This study was performed to determine the relative frequency of positioning errors, to identify those errors directly responsible for diagnostically inadequate images, and to assess the quality of panoramic radiographs in a sample of records collected from a dental college. Materials and Methods: This study consisted of 1,782 panoramic radiographs obtained from the Department of Oral and Maxillofacial Radiology. The positioning errors of the radiographs were assessed and categorized into nine groups: the chin tipped high, chin tipped low, a slumped position, the patient positioned forward, the patient positioned backward, failure to position the tongue against the palate, patient movement during exposure, the head tilted, and the head turned to one side. The quality of the radiographs was further judged as being 'excellent', 'diagnostically acceptable', or 'unacceptable'. Results: Out of 1,782 radiographs, 196 (11%) were error free and 1,586 (89%) were present with positioning errors. The most common error observed was the failure to position the tongue against the palate (55.7%) and the least commonly experienced error was patient movement during exposure (1.6%). Only 11% of the radiographs were excellent, 64.1% were diagnostically acceptable, and 24.9% were unacceptable. Conclusion: The positioning errors found on panoramic radiographs were relatively common in our study. The quality of panoramic radiographs could be improved by careful attention to patient positioning.

Positioning errors and quality assessment in panoramic radiography

Manu Dhillon,Srinivasa M Raju,Sankalp Verma,Divya tomar,Raviprakash S Mohan,Manisha Lakhanpal,Bhuvana Krishnamoorthy 대한구강악안면방사선학회 2012 Imaging Science in Dentistry Vol.42 No.4

Purpose: This study was performed to determine the relative frequency of positioning errors, to identify those errors directly responsible for diagnostically inadequate images, and to assess the quality of panoramic radiographs in a sample of records collected from a dental college. Materials and Methods: This study consisted of 1,782 panoramic radiographs obtained from the Department of Oral and Maxillofacial Radiology. The positioning errors of the radiographs were assessed and categorized into nine groups: the chin tipped high, chin tipped low, a slumped position, the patient positioned forward, the patient positioned backward, failure to position the tongue against the palate, patient movement during exposure, the head tilted, and the head turned to one side. The quality of the radiographs was further judged as being ‘excellent’, ‘diagnostically acceptable’, or ‘unacceptable’. Results: Out of 1,782 radiographs, 196 (11%) were error free and 1,586 (89%) were present with positioning errors. The most common error observed was the failure to position the tongue against the palate (55.7%) and the least commonly experienced error was patient movement during exposure (1.6%). Only 11% of the radiographs were excellent, 64.1% were diagnostically acceptable, and 24.9% were unacceptable. Conclusion: The positioning errors found on panoramic radiographs were relatively common in our study. The quality of panoramic radiographs could be improved by careful attention to patient positioning.

Impact of InGaN notch on sensitivity in dielectric modulated dual channel GaN MOSHEMT for label-free biosensing

Mishra Girish Shankar,Mohankumar N.,Singh Sankalp Kumar 한국물리학회 2023 Current Applied Physics Vol.49 No.-

The effect of InGaN notch on sensitivity and Dielectric Modulated (DM) Double Heterojunction (DH) dual channel AlGaN/GaN/InGaN/GaN MOSHEMT (Metal Oxide Semiconductor High Electron Mobility Transistor) for detecting the label-free biomolecules has been investigated in this paper. Biomolecules can be inserted into the nanocavity formed by etching the insulating layer under the gate electrode. The insulator (Al2O3) as a dielectric improves the drive current and device sensitivity because of low leakage and high scalability. In this proposed structure, the presence of InGaN notch increases the carrier confinement in the channel, thereby improving the device sensitivity. The device is simulated using Sentaurus TCAD, and the results show a significant increase in drain current (IDS), up to 3.35 A/mm. The optimization of the device parameters exhibits a high sensitivity (~74%), making it suitable for precise label-free biosensing.

Two-Dimensional Titanium Carbide MXene As a Cathode Material for Hybrid Magnesium/Lithium-Ion Batteries

Byeon, Ayeong,Zhao, Meng-Qiang,Ren, Chang E.,Halim, Joseph,Kota, Sankalp,Urbankowski, Patrick,Anasori, Babak,Barsoum, Michel W.,Gogotsi, Yury American Chemical Society 2017 ACS APPLIED MATERIALS & INTERFACES Vol.9 No.5

<P>As an alternative to pure lithium-ion, Lit, systems, a hybrid magnesium, Mg2+, and Li+ battery can potentially combine the high capacity, high voltage, and fast Li+ intercalation of Li-ion battery cathodes and the high capacity, low cost, and dendrite-free Mg metal anodes. Herein, we report on the use of two-dimensional titanium carbide, Ti3C2Tx (MXene), as a cathode in hybrid Mg2+/Li+ batteries, coupled with a Mg metal anode. Free-standing and flexible Ti3C2Tx/carbon nanotube composite 'paper' delivered-,100 mAh at 0.1 C and similar to 50 mAh g(-1) at 10 C. At 1 C the capacity was maintained for >500 cycles at 80 mAh g(-1). The Mo2CTx MXene also demonstrated good performance as a cathode material in this hybrid battery. Considering the variety of available MXenes, this work opens the door for exploring a new large family of 2D materials with high electrical conductivity and large intercalation capacity as cathodes for hybrid Mg2+/Li+ batteries.</P>

Resonant Tunneling Barriers in Quantum Dots-in-a-Well Infrared Photodetectors

Barve, A.,Jiayi Shao,Sharma, Y.D.,Vandervelde, T.E.,Sankalp, K.,Sang Jun Lee,Sam Kyu Noh,Krishna, S. IEEE 2010 IEEE journal of quantum electronics Vol.46 No.7

<P>The use of resonant tunneling (RT) barriers in the design of quantum dots-in-a-well (DWELL) infrared photodetectors is reported. The design of RT barriers for a variety of goals has been discussed. For simple DWELL designs, we demonstrate 2-3 orders-of-magnitude reduction in the dark current, with significant increase in the specific detectivity (<I>D</I> <SUP>*</SUP>) of the device. Two RT barriers are designed to selectively extract midwave and longwave components of the spectral response. We also report the use of RT barriers on strain-optimized quantum dots-in-a-double-well (DDWELL) structures to achieve very low dark current levels with peak <I>D</I> <SUP>*</SUP> of 2.9 ×10<SUP>10</SUP> cm· Hz<SUP>1/2</SUP> /W for a longwave infrared detection. Ability to select a particular wavelength in the spectral response is demonstrated with DDWELL architectures as well.</P>

Lithium-ion capacitors with 2D Nb₂CT_x (MXene) – carbon nanotube electrodes

Byeon, Ayeong,Glushenkov, Alexey M.,Anasori, Babak,Urbankowski, Patrick,Li, Jingwen,Byles, Bryan W.,Blake, Brian,Van Aken, Katherine L.,Kota, Sankalp,Pomerantseva, Ekaterina,Lee, Jae W.,Chen, Ying,Gog Elsevier 2016 Journal of Power Sources Vol.326 No.-

<P><B>Abstract</B></P> <P>There is a growing interest to hybrid energy storage devices, such as lithium-ion capacitors, in which battery-type electrodes are combined with capacitor-type ones. It is anticipated that the energy density (either gravimetric or volumetric) of lithium-ion capacitors is improved if pseudocapacitive or fast insertion materials are used instead of conventional activated carbon (AC) in the capacitor-type electrode. MXenes, a new family of two-dimensional transition metal carbides, demonstrate metallic conductivity and fast charge-discharge behavior that make them suitable for this application. In this study, we move beyond single electrodes, half-cell studies and demonstrate three types of hybrid cells using Nb<SUB>2</SUB>CT<SUB>x</SUB>–carbon nanotube (CNT) films. It is shown that lithiated graphite/Nb<SUB>2</SUB>CT<SUB>x</SUB>-CNT, Nb<SUB>2</SUB>CT<SUB>x</SUB>-CNT/LiFePO<SUB>4</SUB> and lithiated Nb<SUB>2</SUB>CT<SUB>x</SUB>-CNT/Nb<SUB>2</SUB>CT<SUB>x</SUB>-CNT cells are all able to operate within 3 V voltage windows and deliver capacities of 43, 24 and 36 mAh/g (per total weight of two electrodes), respectively. Moreover, the polarity of the electrodes can be reversed in the symmetric Nb<SUB>2</SUB>CT<SUB>x</SUB>-CNT cells from providing a positive potential between 0 and 3 V to a negative one from −3 to 0 V. It is shown that the volumetric energy density (50–70 Wh/L) of our first-generation devices with MXene electrodes exceeds that of a lithium titanate/AC capacitor.</P> <P><B>Highlights</B></P> <P> <UL> <LI> 3 types of lithium-ion capacitors using Nb<SUB>2</SUB>CT<SUB>x</SUB>-CNT as one electrode were tested. </LI> <LI> The highest volumetric energy density of 50–70 Wh/L was achieved. </LI> <LI> Energy density of symmetric cell exceeds that of lithium titanate/activated carbon. </LI> <LI> The lithiated graphite/Nb<SUB>2</SUB>CT<SUB>x</SUB>-CNT shows the highest gravimetric performance. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>