Browse Items (5589 total)
Sort by:
-
Green Luminescence and Irradiance Properties of Carbon Dots Cross-linked with Polydimethylsiloxane
In the present report, we have synthesized carbon dots by using anthracite coal as a precursor. The purpose of this work is to address the sensitivity and surface coating ability of carbon dots with polydimethylsiloxane (PDMS) polymer. The photoluminescence study shows the shift in emission wavelength of carbon dots in water and polymer individually for different excitation wavelengths (320-480 nm). The shifted peaks have higher intensities for higher excitation wavelengths, which are desirable for real world optical applications. This study gives a simple and novel approach to tune the fluorescence spectrum over the entire UV region just by varying the concentration of carbon dots in the polymer base. Detailed characterization revealed that the increase in the intensity of emission peaks can be obtained by using a polymer base system and changing the concentration of carbon dots. This new approach significantly opens a new window for multiapproach sensing methods. The irradiance studies of carbon dots with PDMS resulted in a decrease in absorption. This explains the photodegradation and photophysical properties of the material. The wettability property of the sample by using contact angle studies reveals its significance in coating industries such as nanoengineering, adhesives, casting, and injection molding. Copyright 2019 American Chemical Society. -
ALT speech recognition system using F0 improvement and spectral tilt method
Human Beings use voice as the medium for communication. Human Speech is a very complex signal with multiple frequencies, amplitudes and intensities that mix up to convey specific information. In international terminology, voice disorders are described as dysphonia. Various dysphonias are clearly organic origin due to nervous, muscular, neuro or cellular degenerative disease affecting the body or it is from local laryngeal changes. Other dysphonias having no visible laryngeal causes are grouped as non organic involving habitual dysphonias that arise from faulty speaking habits or the psycho genic dysphonias that stem from emotional causes. This paper looks at a speech recognition system for disordered speech generated by Physically Disabled people using Artificial Larynx Transducer (ALT) device from the perspective of Speech Signal Processing. From the ALT speech features like formant, pitch and spectral tilt is estimated. For formant frequency estimation RNN technique is used. Before training the system pitch frequency improvement is accomplished. Now the features and homomorphic based coefficients are used for training the system. The same operation is performed during the test phase and compared with the training set. Comparison and decision making is accomplished using distance estimator. BEIESP. -
Impact of determinants on early internationalization: An exploratory study of Indian engineering SMEs
Purpose: The purpose of this paper is to analyze the influence of determinants on early internationalization in the context of an emerging economy, i.e. India. Design/methodology/approach: The study is based on an ex post facto exploratory research using primary data collected from a sample of 102 exporting small- and medium-sized enterprises (SMEs) in Bangalore. Findings: The overall results reveal that it is the proactive entrepreneurs and their previous experience that determine the early internationalization of SMEs. Further, competitive constraint was a major obstacle to enter the international market at an early age for late internationalized SMEs. Practical implications: The policy initiatives should aim to develop the international orientation of the entrepreneurs in the firm as a precursor for the formulation and subsequent implementation of internationalization strategies. Originality/value: Although studies have been conducted on determinants and early internationalization, these are confined to a few dimensions, and none of the studies have looked into the issues affecting the early internationalization holistically and with respect to SMEs in India. 2019, Emerald Publishing Limited. -
Effect of supercooling on the microstructural development and optimization of physical properties of melt grown SnSe crystals
The microstructural development of stoichiometric tin monoselenide (SnSe) crystals grown by vertical BridgmanStockbarger method using an indigenously fabricated furnace has been investigated under high vacuum (~ 10?6 mbar). The ampoule translation rate (tr) and supercooling, ?T (= Tm ? T, where Tm is the melting point and T is the crystallization temperature) were varied in the range, 122mm/h and 20100C respectively. Enhancement of ?T and tr led to constitutional supercooling, inducing compositional changes and non-stoichiometry. Low ?T (2040C) and high tr (1210mm/h) resulted in globules, flakes and cavities. When ?T = 60C and tr = 9 to 7mm/h, mounds were formed with closed contours and ripples, due to atomically rough liquidsolid (l-?) interface. Fine tuning of ?T (60C) and tr (2mm/h) enabled smooth planar interface, so as to yield good quality crystalline structures with periodic atomic deposition promoting crystal growth, layer-by-layer. Energy dispersive analysis by X-rays and powder X-ray diffraction studies revealed appreciable crystallinity, chemical homogeneity and phase purity. The density of crystals estimated from crystallographic data (6.183g/cm3) corroborates with that obtained utilizing Archimedes principle. Thermogravimetric and microindentation analyses established thermal and mechanical stability. The low etch pit density (~ 102 cm?2) manifests nearly perfect growth of crystals than their melt counterparts. UVVisNIR and PL spectra reflected direct transition with an energy gap of 1.32eV, validating immense potential of the grown crystals for photovoltaic applications. 2019, Springer Science+Business Media, LLC, part of Springer Nature. -
Perception of Entrepreneurial Ecosystem: Testing the ActorObserver Bias
Entrepreneurial ecosystem is the interacting socio-economic environment that facilitates entrepreneurs to start and develop their enterprises. A vibrant and supportive entrepreneurial ecosystem is necessary for the start-up and growth of an enterprise. The entrepreneurial action would largely depend on the perception of entrepreneurs about the ecosystem. In this context, a study was designed to understand the perceptions of actors (entrepreneurs) and observers (non-entrepreneurs) on various components of the entrepreneurial ecosystem. Data for this study were collected from 296 entrepreneurs and 315 non-entrepreneurs from India, who responded to a 77-item questionnaire by giving their ratings of various aspects of the ecosystem on a 5-point scale. Findings of the study showed that perceptions of the entrepreneurial ecosystem were significantly different for most of the subgroups. Most notable among these differences was those between entrepreneurs and non-entrepreneurs, where the mean scores on all dimensions were found to be significantly higher for non-entrepreneurs than for entrepreneurs except for entrepreneurial capability which was found to be higher for entrepreneurs. Hence, the hypothesis of actorobserver bias in the perceptions of entrepreneurs and non-entrepreneurs is supported. 2019 SAGE Publications. -
N-tier modelling of robust key management for secure data aggregation in wireless sensor network
Security problems in Wireless Sensor Network (WSN) have been researched from more than a decade. There are various security approaches being evolving towards resisting various forms of attack using different methodologies. After reviewing the existing security approaches, it can be concluded that such security approaches are highly attack-specific and doesnt address various associated issues in WSN. It is essential for security approach to be computationally lightweight. Therefore, this paper presents a novel analytical modelling that is based on n-tier approach with a target to generate an optimized secret key that could ensure higher degree of security during the process of data aggregation in WSN. The study outcome shows that proposed system is computationally lightweight with good performance on reduced delay and reduced energy consumption. It also exhibits enhanced response time and good data delivery performance to balance the need of security and data forwarding performance in WSN. 2019 Institute of Advanced Engineering and Science. -
Comparing machine learning and ensemble learning in the field of football
Football has been one of the most popular and loved sports since its birth on November 6th, 1869. The main reason for this is because it is highly unpredictable in nature. Predicting football matches results seems like the perfect problem for machine learning models. But there are various caveats such as picking the right features from an enormous number of available features. There have been many models which have been applied to various football-related datasets. This paper aims to compare Support Vector Machines a machine learning model and XGBoost an Ensemble learning model and how Ensemble Learning can greatly improve the accuracy of the predictions. Copyright 2019 Institute of Advanced Engineering and Science. All rights reserved. -
Effect of the Process Parameters on Machining of GFRP Composites for Different Conditions of Abrasive Water Suspension Jet Machining
The selection of parameters for abrasive water suspension jet (AWSJ) machining of GFRP composites is a major aspect to be considered for optimizing the process. Generally, machining of plastics, polymer matrix composites are accomplished by the AWSJ machining carried out in the presence of atmospheric air; however, the existence of air around the AWSJ may lead to expansion of jet which results in increase in the kerf width and surface roughness; thus to overcome this drawback, an effort has been made in the current work to compare the effect of different process parameters on kerf width and surface roughness while using AWSJ techniques for machining glass fibre-reinforced plastic composite submerged in water. The exploratory outcomes have herewith validated the fact that the surface roughness and kerf width diminishes in under water machining when contrasted with that of free air machining; this is majorly attributed to the fact that the jet diameter reduces in under water AWSJ machining, thereby reducing the kerf width and surface roughness for optimized values of the parameters of speed, feed and standoff distance. Further, the experimental trials have clearly shown that the AWSJ machining used with an optimized set of parameters yields better machining capabilities as compared to abrasive water jet machining. 2019, King Fahd University of Petroleum & Minerals. -
Degradation of azodyes in wastewater by using hydrodynamic cavitation technique
The organic waste water discharged from various industries consists of large amounts of dyes & cyanides & other toxic carcinogenic pollutants which are harmful to human health & ecosystem. Release of carcinogenic dyes is hazardous & has a detrimental effect on the well being of an individual. The present work is focussed at finding the viability of hydrodynamic cavitations process in the degradation of dyes. To study the degradation, influence of various parameters on degradation rate has been studied. BEIESP. -
Nonlinear thermo-solutal convective flow of Casson fluid over an oscillating plate due to non-coaxial rotation with quadratic density fluctuation: Exact solutions
Purpose: The nonlinear density thermal/solutal fluctuations in the buoyancy force term cannot be ignored when the temperature/concentration difference between the surface and fluid is large. The purpose of this paper is to investigate the nonlinear density fluctuations across a flowing fluid with heat mass transfer effects on a non-axial rotating plate. Therefore, the impact of nonlinear convection in the flow of Casson fluid over an oscillating plate has been analytically investigated. Design/methodology/approach: The governing equations are modeled with the help of conservation equations of velocity, energy and concentration under the transient-state situation. The dimensional governing equations are non-dimensionalized by utilizing non-dimensional variables. Later, the subsequent non-dimensional problem has been solved analytically using Laplace transform method. Findings: The effects of thermal Grashof number, solute Grashof number, nonlinear convection parameters, Casson fluid parameter, unsteady parameter, Prandtl number as well as Schmidt number on hydrodynamic, thermal and solute characteristics have been quantified. The numeric data for skin friction coefficient, Nusselt number and Sherwood number are presented. It is established the nonlinear convection aspect has a significant influence on heat and mass transport characteristics. Originality/value: The effect of nonlinear convection in the dynamics of Casson fluid past an oscillating plate which is rotating non-axially is investigated for the first time. 2019, Emerald Publishing Limited. -
Significance of bar quenching in the global quenching of star formation
The suppression of star formation in the inner kiloparsec regions of barred disk galaxies due to the action of bars is known as bar quenching. We investigate here the significance of bar quenching in the global quenching of star formation in the barred galaxies and their transformation to passive galaxies in the local Universe. We do this by measuring the offset of quenched barred galaxies from star-forming main sequence galaxies in the star formation rate-stellar mass plane and comparing it with the length of the bar, which is considered as a proxy of bar quenching. We constructed the star formation rate-stellar mass plane of 2885 local Universe face-on strong barred disk galaxies (z< 0.06) identified by Galaxy Zoo. The barred disk galaxies studied here fall on the star formation main sequence relation with a significant scatter for galaxies above stellar mass 1010.2M. We found that 34.97% galaxies are within the intrinsic scatter (0.3 dex) of the main sequence relation, with a starburst population of 10.78% (above the 0.3 dex) and a quenched population of 54.25% (below the-0.3 dex) of the total barred disk galaxies in our sample. Significant neutral hydrogen (MHI > 109Mwith log MHI/M?-1.0 to-0.5) is detected in the quenched barred galaxies with a similar gas content to that of the star-forming barred galaxies. We found that the offset of the quenched barred galaxies from the main sequence relation is not dependent on the length of the stellar bar. This implies that the bar quenching may not contribute significantly to the global quenching of star formation in barred galaxies. However, this observed result could also be due to other factors such as the dissolution of bars over time after star formation quenching, the effect of other quenching processes acting simultaneously, and/or the effects of environment. ESO 2019. -
An enhancing reversible data hiding for secured data using shuffle block key encryption and histogram bit shifting in cloud environment
Nowadays there are numerous intruders trying to get the privacy information from cloud resources and consequently need a high security to secure our data. Moreover, research concerns have various security standards to secure the data using data hiding. In order to maintain the privacy and security in the cloud and big data processing, the recent crypto policy domain combines key policy encryption with reversible data hiding (RDH) techniques. However in this approach, the data is directly embedded resulting in errors during data extraction and image recovery due to reserve leakage of data. Hence, a novel shuffle block key encryption with RDH technique is proposed to hide the data competently. RDH is applied to encrypted images by which the data and the protection image can be appropriately recovered with histogram bit shifting algorithm. The hidden data can be embedded with shuffle key in the form of text with the image. The proposed method generates the room space to hide data with random shuffle after encrypting image using the definite encryption key. The data hider reversibly hides the data, whether text or image using data hiding key with histogram shifted values. If the requestor has both the embedding and encryption keys, can excerpt the secret data and effortlessly extract the original image using the spread source decoding. The proposed technique overcomes the data loss errors competently with two seed keys and also the projected shuffle state RDH procedure used in histogram shifting enhances security hidden policy. The results show that the proposed method outperforms the existing approaches by effectively recovering the hidden data and cover image without any errors, also scales well for large amount of data. 2018, Springer Science+Business Media, LLC, part of Springer Nature. -
Multiple slip effects on MHD non-Newtonian nanofluid flow over a nonlinear permeable elongated sheet: Numerical and statistical analysis
Purpose: The purpose of this paper is to examine the interaction effects of a transverse magnetic field and slip effects of Casson fluid with suspended nanoparticles over a nonlinear stretching surface. Mathematical modeling for the law of conservation of mass, momentum, heat and concentration of nanoparticles is executed. Design/methodology/approach: Governing nonlinear partial differential equations are reduced into nonlinear ordinary differential equations and then shooting method is employed for its solution. The slope of the linear regression line of the data points is calculated to measure the rate of increase/decrease in the reduced Nusselt number. Findings: The effects of magnetic parameter (0=M=4), Casson parameter (0.1=?<8), nonlinear stretching parameter (0=n=3) and porosity parameter (0=P=6) on axial velocity are shown graphically. Numerical results were compared with another numerical approach and an excellent agreement was observed. This study reveals the fact that the Brownian motion parameter and boundary layer thickness have a direct relationship with temperature. Also, Brownian motion and thermophoresis contribute to an increase in the thermal boundary layer thickness. Originality/value: Despite the immense significance and repeated employment of non-Newtonian fluids in industry and science, no attempt has been made up till now to inspect the Casson nanofluid flow with a permeable nonlinear stretching surface. 2019, Emerald Publishing Limited. -
GASP XVIII: Star formation quenching due to AGN feedback in the central region of a jellyfish galaxy
We report evidence for star formation quenching in the central 8.6 kpc region of the jellyfish galaxy JO201 that hosts an active galactic nucleus (AGN), while undergoing strong ram-pressure stripping. The ultraviolet imaging data of the galaxy disc reveal a region with reduced flux around the centre of the galaxy and a horse-shoe-shaped region with enhanced flux in the outer disc. The characterization of the ionization regions based on emission line diagnostic diagrams shows that the region of reduced flux seen in the ultraviolet is within the AGN-dominated area. The CO J2-1 map of the galaxy disc reveals a cavity in the central region. The image of the galaxy disc at redder wavelengths (9050-9250 reveals the presence of a stellar bar. The star formation rate map of the galaxy disc shows that the star formation suppression in the cavity occurred in the last few 108 yr. We present several lines of evidence supporting the scenario that suppression of star formation in the central region of the disc is most likely due to the feedback from the AGN. The observations reported here make JO201 a unique case of AGN feedback and environmental effects suppressing star formation in a spiral galaxy. 2019 The Author(s) Published by Oxford University Press on behalf of the Royal Astronomical Society. -
Light weight authentication protocol for WSN using ECC and hexagonal numbers
Wireless Sensor Network (WSN) is a spatially distributed network. It contains many numbers of distributed, self-directed, small, battery powered devices called sensor nodes or motes. In recent years the deployment of WSN in various application domains are growing in a rapid pace as with the upcoming boom of Internet of Things (IoT) and Internet of Everything (IoE). However, the effectiveness of the WSN deployment is restricted due to the constrained computation and power source. Hence, many researchers have been proposing new approaches and models to improve the efficiency of the domain specific WSN deployment procedures. Though, many research communities addressing various issues in WSN deployment, still the privacy and security of such networks are susceptible to various network attacks. Thus, it is necessary to practice different models for authentication and privacy preservation in a highly dynamic resource constrained WSN environment to realize the effectiveness and efficiency of the deployment. Hence, this paper addressing an authentication scheme that can reduce energy consumption without compromising on security and privacy. In order to provide a light weight authentication mechanism, this paper proposing an authentication mechanism for WSN deployment by combining the features of Elliptic Curve Cryptography (ECC) and Hexagonal numbers. The feature of ECC is used to reduce the key size and the effectiveness of generating hexagonal numbers is used for minimizing the energy consumption in a resource constrained WSN environment. The results of the proposed approach are evaluated with the different authentication models and the results were indicating that the proposed approach can perform better than the other approaches. 2019 Institute of Advanced Engineering and Science. -
Platinum decorated polythiophene modified stainless steel for electrocatalytic oxidation of benzyl alcohol
Abstract: Platinum nanoparticles were electrochemically deposited on conducting polymer polythiophene (PTh)-coated stainless steel (SS) substrate. A thin layer of PTh on the steel substrate facilitates uniform deposition of Pt nanoparticles on the substrate, thereby improving the surface area to a great extent. The electrochemical properties of the modified electrodes were analyzed by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The physicochemical properties of the modified electrodes were investigated by Scanning electron microscopy (SEM), Transmission electron microscopy (TEM), X-ray diffraction spectroscopy (XRD), Raman spectroscopy, and Fourier transform infrared spectroscopy (FTIR). The proposed method has been applied for the electrocatalytic oxidation of benzyl alcohol in the presence of a mediator, 2,2,6,6-tetramethylpiperidine 1-oxyl (TEMPO). Cyclic voltammetric studies reveal that the electrocatalytic activity of PtPTh/SS electrode is higher than that of PTh/SS electrode toward the conversion of benzyl alcohol to benzaldehyde. Graphic abstract: [Figure not available: see fulltext.]. 2019, Springer Nature B.V. -
Understanding blame attributions in rape among legal professionals
Rape in the Indian context, is a prominent issue, greatly influenced by socio-cultural values and beliefs. Victim blaming and the concept of an ideal victim is a social evil that makes life difficult for rape survivors. What would happen if officials responsible for providing justice possess this tendency? The study aimed at understanding this question through a qualitative study on eight legal professionals including two magistrates and six advocates. The data obtained was analysed using thematic network analysis as well as content analysis. It was observed that victim blaming was present in the responses given, but blame was directed onto other factors as well. Victim blaming varied with victim characteristics and blame was greater in case of acquaintance rape rather than stranger rape. Culture based stereotypes, sex roles and rape myths were observed and seemed to affect the way they made decisions. A more extensive study in future including a broader sample and professionals from different administrative realms can help understand the issue better. 2019 International Journal of Criminal Justice Sciences (IJCJS). -
An exploration of attitudes toward dogs among college students in Bangalore, India
Conversations in the field of anthrozoology include treatment and distinction of food animals, animals as workers versus pests, and most recently, emerging pet trends including the practice of pet parenting. This paper explores attitudes toward pet dogs in the shared social space of urban India. The data include 375 pen-and-paper surveys from students at CHRIST (Deemed to be University) in Bangalore, India. Reflecting upon Serpells biaxial concept of dogs as a relationship of affect and utility, the paper considers the growing trend of pet dog keeping in urban spaces and the increased use of affiliative words to describe these relationships. The paper also explores potential sex differences in attitudes towards pet and stray dogs. Ultimately, these findings suggest that the presence of and affiliation with pet dogs, with reduced utility and increased affect, is symptomatic of cultural changes typical of societies encountering the second demographic transition. Despite this, sex differences as expected based upon evolutionary principles, remain present, with women more likely to emphasize health and welfare and men more likely to emphasize bravery and risk taking. 2019 by the authors. Licensee MDPI, Basel, Switzerland. -
Speech to text conversion and summarization for effective understanding and documentation
Speech, is the most powerful way of communication with which human beings express their thoughts and feelings through different languages. The features of speech differs with each language. However, even while communicating in the same language, the pace and the dialect varies with each person. This creates difficulty in understanding the conveyed message for some people. Sometimes lengthy speeches are also quite difficult to follow due to reasons such as different pronunciation, pace and so on. Speech recognition which is an inter disciplinary field of computational linguistics aids in developing technologies that empowers the recognition and translation of speech into text. Text summarization extracts the utmost important information from a source which is a text and provides the adequate summary of the same. The research work presented in this paper describes an easy and effective method for speech recognition. The speech is converted to the corresponding text and produces summarized text. This has various applications like lecture notes creation, summarizing catalogues for lengthy documents and so on. Extensive experimentation is performed to validate the efficiency of the proposed method. Copyright 2019 Institute of Advanced Engineering and Science. All rights reserved. -
Stereotype threat and psychological wellbeing in children of prisoners
Stereotypes are ideas that one holds regarding individuals because of their membership to a specific group. The current research was undertaken to study stereotype perception and stereotype threat on the psychological wellbeing of children of prisoners. Eight children of prisoners in the age range of 17 to 25 (females = 4), whose fathers were in prison for more than a year, participated in the study. Semi-structured interview method was used to collect data from the participants and data were analyzed using thematic network analysis method. Results revealed that children of prisoners strongly perceive stereotypes against them and they conform to stereotypes. Further to this, it was found that stereotype threat had positive effects in terms of increased goal-directed behavior and negative effects in terms of reduced happiness and increased feelings of anger and sadness. These Undings are discussed in light of previous literature on the effects of stereotypes on behavior. 2019 International Journal of Criminal Justice Sciences (IJCJS).