Approximation of Drygas functional equation in quasi-Banach space

Ravinder Kumar Sharma,Sumit Chandok 한국전산응용수학회 2023 Journal of applied mathematics & informatics Vol.41 No.3

In this paper, we investigate the Hyers-Ulam-Rassias stability for a Drygas functional equation \begin{equation*} g( u + v ) + g( u - v ) = 2g(u) + g (v)+ g(-v) \end{equation*} in the setting of quasi-Banach space using fixed point approach. Also, we give general results on hyperstability of a Drygas functional equation. The results obtain in this paper extend various previously known results in the setting of quasi-Banach space. Some examples are also illustrated.

A Robust Fingerprint Matching System Using Orientation Features

( Ravinder Kumar ),( Pravin Chandra ),( Madasu Hanmandlu ) 한국정보처리학회 2016 Journal of information processing systems Vol.12 No.1

The latest research on the image-based fingerprint matching approaches indicates that they are less complex than the minutiae-based approaches when it comes to dealing with low quality images. Most of the approaches in the literature are not robust to fingerprint rotation and translation. In this paper, we develop a robust fingerprint matching system by extracting the circular region of interest (ROI) of a radius of 50 pixels centered at the core point. Maximizing their orientation correlation aligns two fingerprints that are to be matched. The modified Euclidean distance computed between the extracted orientation features of the sample and query images is used for matching. Extensive experiments were conducted over four benchmark fingerprint datasets of FVC2002 and two other proprietary databases of RFVC 2002 and the AITDB. The experimental results show the superiority of our proposed method over the well-known image-based approaches in the literature.

InAs quantum dot-in-a-well heterostructures with InGaAs, GaAsN and GaAsSb well using digital alloy capping layer

Kumar Ravindra,Saha Jhuma,Tongbram Binita,Panda Debiprasad,Gourishetty Raveesh,Kumar Ravinder,Gazi Sanowar Alam,Chakrabarti Subhananda 한국물리학회 2023 Current Applied Physics Vol.47 No.-

In this work, the authors introduced a novel approach called digital alloy capping layer (DACL) and investigated its effect on the optical and structural properties of InAs quantum dot-in-a-well (DWELL) heterostructures. In DACL, a conventional thick well layer is digitized equally with different compositions analogous to short-period-superlattice (SPS). The DACL approach’s effect has been studied experimentally and theoretically on DWELL heterostructures with InxGa1-xAs as the well material. The photoluminescence (PL) study reveals that DACL observes a red-shift of ~55 nm as compared to AACL approached heterostructures. High-resolution X-ray diffraction (HRXRD) results reveal higher In-content, controlled In-out diffusion from InAs QD, and improved in-plane strain in DACL samples compared to the analog sample. The study has been extended to QD heterostructures with GaAs1-xNx and GaAs1-ySby as well materials, and comprehensive analysis has been carried out. Hence, the DWELL heterostructures with the DACL approach can be utilized to fabricate infrared photodetector devices.

A time-dependent multistate model for bacteriorhodopsin photocycle

Ravinder Kumar Banyal,Gopalakrishna M. Hegde,B. Raghavendra Prasad,K.P.J. Reddy 한국물리학회 2005 Current Applied Physics Vol.5 No.2

A time-dependent theoretical model based on the rate equations for all the photochemical states of bacteriorhodopsin (bR) isdeveloped. A recursive method is adopted to solve the rate equations exactly, with an explicit temporal and intensity dependenceof the population densities. Simulated results for a thin wild type bR lm show that each intermediate state has a optimum popu-lation that depends uniquely on incident intensity and time. The model provides an analytical framework for optimization of bR forvarious electronics and photonic applications.. 2004 Elsevier B.V. All rights reserved.PACS:42.70.Gi; 82.39.Rt; 87.15.Aa; 87.14.Ee

A Robust Fingerprint Matching System Using Orientation Features

Kumar, Ravinder,Chandra, Pravin,Hanmandlu, Madasu Korea Information Processing Society 2016 Journal of information processing systems Vol.12 No.1

The latest research on the image-based fingerprint matching approaches indicates that they are less complex than the minutiae-based approaches when it comes to dealing with low quality images. Most of the approaches in the literature are not robust to fingerprint rotation and translation. In this paper, we develop a robust fingerprint matching system by extracting the circular region of interest (ROI) of a radius of 50 pixels centered at the core point. Maximizing their orientation correlation aligns two fingerprints that are to be matched. The modified Euclidean distance computed between the extracted orientation features of the sample and query images is used for matching. Extensive experiments were conducted over four benchmark fingerprint datasets of FVC2002 and two other proprietary databases of RFVC 2002 and the AITDB. The experimental results show the superiority of our proposed method over the well-known image-based approaches in the literature.

Radioprotective and Antioxidant Activity of Fractionated Extracts of Berries of Hippophae rhamnoides

Rakesh Kumar Sharma,Raman Chawla,Rajesh Arora,Shikha Singh,Ravinder Kumar Sagar,Raj Kumar,Ashok Sharma,Manju L. Gupta,Surender Singh,Jagdish Prasad,Haider A. Khan,Anand Swaroop,A.K. Sinha,A.K. Gupta,R 한국식품영양과학회 2007 Journal of medicinal food Vol.10 No.1

Plants are an abundant source of medicinal compounds, some of which are useful in combating free radical-1002 (flavonoid-poor fraction) of Hippophae rhamnoideswere screened on the basis of their reducing power in the aqueousphase. REC-1001 was selected for further study, since it exhibited 27.38 times higher antioxidant activity than REC-1002.REC-1001 also showed significant (P. .05) membrane protection potential at 50 .g/mL, which was attributed to its abilityto scavenge peroxyl radicals (64.82. 1.25% scavenging within 1,440 min). A significant (P. .05) difference of 67.02% infree radical scavenging activity at 1,000 ng/mL between REC-1001 and vitamin E demonstrated the extract fraction’s worthc-tion. Further, REC-1001 was found to be nontoxic up to 200 mg/kg of body weight. This research suggests that the REC-1001 fraction of H. rhamnoidesextract is a safe and effective antioxidant nutraceutical product.

Post-Pollination Biochemical Changes in the Floral Organs of Rhynchostylis retusa (L.) Bl. and Aerides multiflora Roxb (Orchidaceae)

( Lucky Kumar Attri ),( Harsh Nayyar ),( Ravinder Kumar Bhanwra ),( Suraj Prakash Vij ) 한국식물학회 2007 Journal of Plant Biology Vol.50 No.5

If left unpollinated, the flowers of Aerides multiflora (Roxb.) and Rhynchostylis retusa (L.) Bl. can remain fresh for 17 and 24 d, respectively. However, they begin to wilt at 2 to 3 days after pollination (DAP) and 3 to 4 DAP, respectively, and become senescent at 5 DAP and 7 DAP, respectively. When measured at two developmental phases - Stage 1, start of wilting and Stage 2, progression to senescence - all the floral organs from pollinated flowers had higher contents of total soluble sugars, reducing sugars, and free amino acids than those from unpollinated flowers. A corresponding increase was noted in the activities of hydrolytic enzymes, i.e., α-amylase, β-amylase, and invertase, and proteolytic enzymes (proteases) in those organs. This indicated that signals related to pollination had up-regulated those activities, leading to a breakdown of complex molecules into simpler ones for mobilization. The amounts of sugars and enzyme activity were relatively greater in the pollinated flowers of A. multiflora compared with R. retusa, and levels were always higher in the floral lips and perianths. When inhibitors of auxin (0.25mM TIBA) or ethylene (0.25 mM AgNO3) were applied to the pollinated flowers, their senescence was partially prevented, thus signifying hormonal involvement in governing the pollination-induced biochemical alterations normally found in those organs.

Quasi-electrostatic Whistler Wave Dynamics in Earth’s Radiation Belt

Kumar, Sanjay,Sharma, R. P.,Moon, Y.-J.,Goyal, Ravinder American Astronomical Society 2017 The Astrophysical journal Vol.851 No.1

<P>We present a semi-analytical model to study the dynamics of quasi-electrostatic whistler (hereafter, referred to as QEW) waves in Earth's outer radian belt. QEW wave is a new mode of whistler waves and comes into existence when a whistler wave propagates obliquely close to the resonance cone angle. The equations for self-driven QEW waves and density perturbation are obtained by a fluid model and solved using a high-performance numerical simulation. The wave localizes and therefore generates filaments/or thin sheets obliquely to the ambient magnetic field by ponderomotive effect, which arises due to a QEW wave. These thin sheets become more complex and intense with time and finally saturate when the modulational instability attains a quasi-steady state. To analyze the turbulence from QEW waves in the radiation belt, we present the electric field power spectrum of QEW waves with frequency. The spectrum can be given by the power law having scaling of the order of f(-2.3) at high frequency, i.e., in the dissipation range. The steeper spectrum at higher frequency may result from the energization of charged particles by energy taken from the fluctuations.</P>

Morphology of the Esophageal Hiatus: Is It Different in 3 Types of Hiatus Hernias?

( Dushyant Kumar ),( Ali Zifan ),( Gary Ghahremani ),( David C Kunkel ),( Santiago Horgan ),( Ravinder K Mittal ) 대한소화기 기능성질환·운동학회 2020 Journal of Neurogastroenterology and Motility (JNM Vol.26 No.1

Background/Aims The esophageal hiatus is formed by the right crus of the diaphragm in the majority of subjects. Contraction of the hiatus exerts a sphincter-like action on the lower esophageal sphincter (LES). The aim is to study the hiatal anatomy (using CT scan imaging) and function (using high-resolution manometry [HRM]), and esophageal motor function in patients with sliding and paraesophageal hiatal hernia. Methods We assessed normal subjects (n = 20), patients with sliding type 1 hernia (n = 18), paraesophageal type 2 hernia (n = 19), and mixed type 3 hernia (n = 19). Hernia diagnosis was confirmed on the upper gastrointestinal series. The hiatal morphology was constructed from the CT scan images. The LES pressure and relaxation, percent peristalsis, bolus pressure, and hiatal squeeze pressure were assessed by HRM. Results The CT images revealed that the esophageal hiatus is formed by the right crus of the diaphragm in all normal subjects and 86% of hernia patients. The hiatus is elliptical in shape with a surface area of 1037 mm² in normal subjects. The hiatal dimensions were larger in patients compared to normal subjects. The HRM revealed impaired LES relaxation and higher bolus pressure in patients with paraesophageal compared to the sliding hernia. The hiatal pinch on HRM was recognized in significantly higher number of patients with sliding as compared to paraesophageal hernia. Conclusions Using a novel approach, we provide details of the esophageal hiatus in patients with various kinds of hiatal hernia. Impaired LES relaxation in paraesophageal hernia may play a role in its pathophysiology and genesis of symptoms.

Determining the Neurocognitive Status and the Functional Ability of Patients to Screen for HIV-Associated Neurocognitive Disorder (HAND)

Ritika Agarwal,Ravinder Singh Aujla,Amit Gupta,Mukesh Kumar 대한치매학회 2020 Dementia and Neurocognitive Disorders Vol.19 No.1

Background and Purpose: To adequately evaluate the extent of neurocognitive impairment in patient living with human immunodeficiency virus (PLHIV), a battery of neuropsychological tests is typically administered which are neither cost effective nor time efficient in the outpatient clinical setting. The aim of the study was to assess neurocognitive status and functional ability of people living with HIV and find a brief screening tool to identify those who would benefit from a full diagnostic evaluation. Methods: The study enrolled 160 PLHIV (80 pre-antiretroviral therapy [ART] and 80 on ART) fulfilling the inclusion and exclusion criteria. Neurocognitive assessment and an assessment of Functional ability was done by using the Montreal Cognitive Assessment (MoCA) and Lawton and Brody Instrumental Activities of Daily Living Scale scale, respectively. Results: The study population consisted of 75.6% males and 24.4% females with mean age of 44±10 years. The overall prevalence of HIV associated neurocognitive disorder (HAND) in the study subjects was 52.5%. Of these, 47.5% had asymptomatic neurocognitive impairment and 5% had minor neurocognitive disorder. In MoCA, the most frequently affected domains were Language (97.6%), visuospatial ability (92.9%) and memory (71.4%). Conclusions: The prevalence of HAND in both groups were similar suggesting that neurocognitive impairment starts early in HIV infection. Memory and Visuospatial function impairment had the most predictive potential for detecting the presence of HAND. HAND screening is recommended in all PLHIV at enrolment into care. Simple tools like MoCA can be used in busy outpatient settings by healthcare workers to screen for HAND.