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Scrutinization of joule heating and viscous dissipation on MHD flow and melting heat transfer over a stretching sheet
The present paper deals with an analysis of the combined effect of Joule heating and viscous dissipation on an MHD boundary layer flow and melting heat transfer of a micro polar fluid over a stretching surface. Governing equations of the problem are transformed into a set of coupled nonlinear ordinary differential equations by applying proper transformations and then they are solved numerically using the RKF-45 method. The method is verified by a comparison with the established results with limiting solution. The influence of the various interesting parameters on the flow and heat transfer is analyzed in detail through plotted graphs. 2018 K.G. Kumar et al., published by Sciendo. -
Scrutinization of thermal radiation, viscous dissipation and Joule heating effects on Marangoni convective two-phase flow of Casson fluid with fluid-particle suspension
The impact of Marangoni convection on dusty Casson fluid boundary layer flow with Joule heating and viscous dissipation aspects is addressed. The surface tension is assumed to vary linearly with temperature. Physical aspects of magnetohydrodynamics and thermal radiation are also accounted. The governing problem is modelled under boundary layer approximations for fluid phase and dust particle phase and then Runge-Kutta-Fehlberg method based numeric solutions are established. The momentum and heat transport mechanisms are focused on the result of distinct governing parameters. The Nusselt number is also calculated. It is established that the rate of heat transfer can be enhanced by suspending dust particles in the base fluid. The temperature field of fluid phase and temperature of dust phase are quite reverse for thermal dust parameter. The radiative heat, viscous dissipation and Joule heating aspects are constructive for thermal fields of fluid and dust phases. The velocity of dusty Casson fluid dominates the velocity of dusty fluid while this trend is opposite in the case of temperature. Moreover qualitative behaviour of fluid phase and dust phase temperature/velocity are similar. 2018 -
SCSLnO-SqueezeNet: Sine Cosine-Sea Lion Optimization enabled SqueezeNet for intrusion detection in IoT
Security and privacy are regarded as the greatest priority in any real-world smart ecosystem built on the Internet of Things (IoT) paradigm. In this study, a SqueezeNet model for IoT threat detection is built using Sine Cosine Sea Lion Optimization (SCSLnO). The Base Station (BS) carries out intrusion detection. The Hausdorff distance is used to determine which features are important. Using the SqueezeNet model, attack detection is carried out, and the network classifier is trained using SCSLnO, which is developed by combining the Sine Cosine Algorithm (SCA) with Sea Lion Optimization (SLnO). BoT-IoT and NSL-KDD datasets are used for the analysis. In comparison to existing approaches, PSO-KNN/SVM, Voting Ensemble Classifier, Deep NN, and Deep learning, the accuracy value produced by devised method for the BoT-IoT dataset is 10.75%, 8.45%, 6.36%, and 3.51% higher when the training percentage is 90. 2023 Informa UK Limited, trading as Taylor & Francis Group. -
Search and analysis of giant radio galaxies with associated nuclei (SAGAN): III. New insights into giant radio quasars
Giant radio quasars (GRQs) are radio-loud active galactic nuclei (AGN) that propel megaparsec-scale jets. In order to understand GRQs and their properties, we have compiled all known GRQs (the GRQ catalogue) and a subset of small (size < 700 kpc) radio quasars (SRQs) from the literature. In the process, we have found ten new Fanaroff-Riley type-II GRQs in the redshift range of 0.66 < z < 1.72, which we include in the GRQ catalogue. Using the above samples, we have carried out a systematic comparative study of GRQs and SRQs using optical and radio data. Our results show that the GRQs and SRQs statistically have similar spectral index and black hole mass distributions. However, SRQs have a higher radio core power, core dominance factor, total radio power, jet kinetic power, and Eddington ratio compared to GRQs. On the other hand, when compared to giant radio galaxies (GRGs), GRQs have a higher black hole mass and Eddington ratio. The high core dominance factor of SRQs is an indicator of them lying closer to the line of sight than GRQs. We also find a correlation between the accretion disc luminosity and the radio core and jet power of GRQs, which provides evidence for disc-jet coupling. Lastly, we find the distributions of Eddington ratios of GRGs and GRQs to be bi-modal, similar to that found in small radio galaxies (SRGs) and SRQs, which indicates that size is not strongly dependent on the accretion state. Using all of this, we provide a basic model for the growth of SRQs to GRQs. ESO 2022. -
Search for brown dwarfs in IC 1396 with Subaru HSC: interpreting the impact of environmental factors on substellar population
Young stellar clusters are predominantly the hub of star formation and hence, ideal to perform comprehensive studies over the least explored substellar regime. Various unanswered questions like the mass distribution in brown dwarf regime and the effect of diverse cluster environment on brown dwarf formation efficiency still plague the scientific community. The nearby young cluster, IC 1396 with its feedback-driven environment, is ideal to conduct such study. In this paper, we adopt a multiwavelength approach, using deep Subaru HSC along with other data sets and machine learning techniques to identify the cluster members complete down to ? 0.03 M? in the central 22 arcmin area of IC 1396. We identify 458 cluster members including 62 brown dwarfs which are used to determine mass distribution in the region. We obtain a star-to-brown dwarf ratio of ? 6 for a stellar mass range 0.03-1 M? in the studied cluster. The brown dwarf fraction is observed to increase across the cluster as radial distance from the central OB-stars increases. This study also compiles 15 young stellar clusters to check the variation of star-to-brown dwarf ratio relative to stellar density and ultraviolet (UV) flux ranging within 4-2500 stars pc?2 and 0.7-7.3 G0, respectively. The brown dwarf fraction is observed to increase with stellar density but the results about the influence of incident UV flux are inconclusive within this range. This is the deepest study of IC 1396 as of yet and it will pave the way to understand various aspects of brown dwarfs using spectroscopic observations in future. 2024 The Author(s). -
Search for low-mass objects in the globular cluster M4. I. Detection of variable stars
With every new discovery of an extrasolar planet, the absence of planets in globular clusters (GCs) becomes more and more conspicuous. Null detection of transiting hot Jupiters in GCs 47 Tuc, ? Cen, and NGC 6397 presents an important puzzle, raising questions about the role played by cluster metallicity and environment on formation and survival of planetary systems in densely populated stellar clusters. GCs were postulated to have many free-floating planets, for which microlensing (ML) is an established tool for detection. Dense environments, well-constrained distances and kinematics of lenses and sources, and photometry of thousands of stars simultaneously make GCs the ideal targets to search for ML. We present first results of a multisite, 69-night-long campaign to search for ML signatures of low-mass objects in the GC M4, which was chosen because of its proximity, location, and the actual existence of a planet. M4 was observed in R and I bands by two telescopes, 1 m T40 and 18-inch C18, of the Wise Observatory, Tel Aviv, Israel, from 2011 April to July. Observations on the 1 m telescope were carried out in service mode, gathering 12 to 48 20 s exposures per night for a total of 69 nights. C18 observations were done for about 4 hr a night for six nights in 2011 May. We employ a semiautomated pipeline to calibrate and reduce the images to the light curves that our group is developing for this purpose, which includes the differential photometry package DIAPL, written by Wozniak and modified by W. Pych. Several different diagnostics are employed for search of variability/transients. While no high-significance ML event was found in this observational run, we have detected more than 20 new variables and variable candidates in the M4 field, which we present here. 2016. The American Astronomical Society. All rights reserved. -
Seasonal study on the Aquatic and Terrestrial Habitat of Edayar region, Ernakulam, Kerala, India
This study examines the plant diversity and physicochemical characteristics of both aquatic and terrestrial ecosystems in the industrialized region of Edayar, Kadungalloor, Ernakulam, Kerala, India. The research is conducted seasonally, encompassing the four seasons of Kerala: southwest monsoon, northeast monsoon, winter season and summer season. Edayar is home to approximately 400 industries. The main objective of this study is to assess the plant diversity with a specific focus on herb and macrophyte diversity, in the Edayar region, along with analyzing the physicochemical properties of soil and water. Random sampling using quadrat techniques is employed to collect data on species diversity. Diversity indices, such as the Simpson Index and Shannon-Wiener index are utilized to analyze the recorded species diversity. Scoparia dulcis L. among herb species and Eichhornia crassipes (Mart.) Solms among macrophytes were found dominating in all the seasons. The results for the physico-chemical analysis of water and soil were found approaching the threshold of standard limits.The findings provide valuable insights into plant diversity and ecological dynamics of the Edayar region, which have been significantly impacted by industrial activities. The outcomes serve as a basis for the development and implementation of effective conservation and management strategies to mitigate potential ecological risks associated with industrial activities in the region. 2024 World Researchers Associations. All rights reserved. -
Seasonal Variation of Physicochemical Parameters and Their Impact on the Algal Flora of Chimmony Wildlife Sanctuary
Background and Objective: The lack of biodiversity knowledge and biodiversity loss are the two inevitable truths around us. Algae are the most crucial organism in our entire biodiversity. The seasonal variation of algal diversity can monitor the environmental changes of the freshwater ecosystem. The present study was conducted because the seasonal changes of algal diversity in Chimmony Wildlife Sanctuary were utterly unknown. Materials and Methods: The algal samples were collected and preserved from ten stations for three seasons (pre-monsoon, monsoon, post-monsoon). The physicochemical parameters of water like temperature, pH, total dissolved solids, total dissolved oxygen, total alkalinity and light intensity of the sampling stations were recorded. Results: The study revealed that the seasonal variation of physicochemical parameters provoked a change in the diversity of Algae. The Chimmony Wildlife Sanctuary has its highest algal diversity during pre-monsoon season. The Chlorophyceae Algae were dominant during the pre-monsoon season, while the Cyanophycean Algae were dominant during monsoon season. The ANOVA (two-way) analysis showed no significant difference between stations and there is a considerable difference between seasons for dissolved oxygen, alkalinity, temperature and total dissolved solids. While for pH, it showed no significant difference between seasons and stations but for light intensity, it showed a substantial difference between stations and seasons. A negative correlation was observed between algal species and seasons. The temperature and dissolved oxygen showed a negative correlation. Conclusion: The physicochemical parameters were changed according to the seasonal variation. Since Algae act as a biological pollution indicator for all the water resources, the study of algal flora according to the seasonal variation is crucial. 2022 Joel Jose and Jobi Xavier. -
Second Order Parallel Tensor on Almost Kenmotsu Manifolds
Let M be an almost Kenmotsu manifold of dimension 2n + 1 having nonvanishing ?-sectional curvature such that tr? > -2n -2. We prove that any second order parallel tensor on M is a constant multiple of the associated metric tensor and obtained some consequences of this. Vector fields keeping curvature tensor invariant are characterized on M. Kyungpook Mathematical Journal -
Sectoral correlations and interlinkages: NSE
An efficient portfolio is a well-diversified portfolio that gives the investor opportunities to earn money and provide cover against risks. Understanding the intersectoral linkages and correlations among various sectors in a stock market will help an investor to diversify the portfolio and reduce risk efficiently. This study aims at examining the underlying linkages and correlations among eight sectors in the Indian National Stock Exchange (NSE) using a Granger causality test under VAR environment. The results of the study based on nine years' data from 2009 to 2018 show that an effective portfolio can have two classifications -stocks from Pharma and Media as group one (defensive stocks) and picks from IT, Bank, Financial Services, Realty, Auto and FMCG sector as group two (somewhat Cyclical). The study further proves that the usual definition for cyclical and defensive sectors have undergone some profound changes. 2020 SCMS Group of Educational Institutions. All rights reserved. -
Secure approach to sharing digitized medical data in a cloud environment
Without proper security mechanisms, medical records stored electronically can be accessed more easily than physical files. Patient health information is scattered throughout the hospital environment, including laboratories, pharmacies, and daily medical status reports. The electronic format of medical reports ensures that all information is available in a single place. However, it is difficult to store and manage large amounts of data. Dedicated servers and a data center are needed to store and manage patient data. However, self-managed data centers are expensive for hospitals. Storing data in a cloud is a cheaper alternative. The advantage of storing data in a cloud is that it can be retrieved anywhere and anytime using any device connected to the Internet. Therefore, doctors can easily access the medical history of a patient and diagnose diseases according to the context. It also helps prescribe the correct medicine to a patient in an appropriate way. The systematic storage of medical records could help reduce medical errors in hospitals. The challenge is to store medical records on a third-party cloud server while addressing privacy and security concerns. These servers are often semi-trusted. Thus, sensitive medical information must be protected. Open access to records and modifications performed on the information in those records may even cause patient fatalities. Patient-centric health-record security is a major concern. End-to-end file encryption before outsourcing data to a third-party cloud server ensures security. This paper presents a method that is a combination of the advanced encryption standard and the elliptical curve Diffie-Hellman method designed to increase the efficiency of medical record security for users. Comparisons of existing and proposed techniques are presented at the end of the article, with a focus on the analyzing the security approaches between the elliptic curve and secret-sharing methods. This study aims to provide a high level of security for patient health records. 2023 Xi'an Jiaotong University -
Secure biometric authentication with de-duplication on distributed cloud storage
Cloud computing is one of the evolving fields of technology, which allows storage, access of data, programs, and their execution over the internet with offering a variety of information related services. With cloud information services, it is essential for information to be saved securely and to be distributed safely across numerous users. Cloud information storage has suffered from issues related to information integrity, data security, and information access by unauthenticated users. The distribution and storage of data among several users are highly scalable and cost-efficient but results in data redundancy and security issues. In this article, a biometric authentication scheme is proposed for the requested users to give access permission in a cloud-distributed environment and, at the same time, alleviate data redundancy. To achieve this, a cryptographic technique is used by service providers to generate the bio-key for authentication, which will be accessible only to authenticated users. A Gabor filter with distributed security and encryption using XOR operations is used to generate the proposed bio-key (biometric generated key) and avoid data deduplication in the cloud, ensuring avoidance of data redundancy and security. The proposed method is compared with existing algorithms, such as convergent encryption (CE), leakage resilient (LR), randomized convergent encryption (RCE), secure de-duplication scheme (SDS), to evaluate the de-duplication performance. Our comparative analysis shows that our proposed scheme results in smaller computation and communication costs than existing schemes. 2021 M et al. All Rights Reserved. -
SECURE DOMINATION IN TRANSFORMATION GRAPH Gxy+
In this paper, we characterize graphs for which the secure domination number of the transformation graph Gxy+ is 1 or 2. Also we prove that for any connected graph G with at least 4 pendant vertices, the secure domination number is greater than or equal to the secure domination number of the transformation graph G-++. We also find a bound for the secure domination number of G-+ when G is a tree. 2024 Jangjeon Research Institute for Mathematical Sciences and Physics. All rights reserved. -
SECURE EQUITABLE SUBDIVISION NUMBER OF GRAPHS
In this paper, we initiate the study of a new domination parameter: the secure equitable subdivision number of graphs. Moreover, we define the secure equitable subdivision critical graphs and the secure equitable subdivision stable graphs. Furthermore, we investigate how to construct a secure equitable subdivision critical graph. 2024, Canadian University of Dubai. All rights reserved. -
Secure Image Transmission Scheme based on DNA Sequences
Cryptography and steganography are the most widely utilized and adopted fields of secure data communication. Data transfer can be secured using a combination of these methods. The data is transmitted from sender to receiver using cryptography, the most secure method. At the same time, steganography performs the information hiding in the form of video, image, or text within a cover image. The sensitive data is hidden, so it is not visible to the human eye. The data is stored and transferred more securely by adding DNA technology to the cryptography. It provides additional data security level and is most commonly employed to implement computation. This research developed a new method for combining cryptography with steganography. There are two phases to the proposed method: image encryption and hide phases and image extraction phases. Encryption is done by using the Signcryption algorithm. Four standard images were utilized as test material for the evaluation. Four factors are used to determine the performance of the proposed method as Peak signal-to-noise ratio (PSNR), Mean Square Error, Entropy, and Structural Similarity Index Measure (SSIM) for hiding and extracting the messages. The implementation is done in python. The proposed method achieves better performance when compared to the previously published works. 2022 Seventh Sense Research Group -
Secure key exchange scheme: A DNA computing-based approach to resist MITM in DHKE
Diffie-Hellman key exchange (DHKE) protocol was a pioneering work and considered as a new direction in the field of cryptography though it is not an encryption protocol. DHKE is a method to exchange the keys securely, based on the discrete logarithm problem. It has applications in internet security protocols including SSL, IP Sec and SSH. The major issue with DHKE is its vulnerability to man in the middle attack (MITM). Various techniques have been proposed to resist the MITM including digital signatures. This paper proposes DNA computing-based encryption techniques to resist MITM in DHKE. DNA cryptography builds on the concepts of biomolecular computations which are considered as one of the emerging directions in the cryptography. The proposed methodology also includes an encryption technique based on DNA-based codebook, secret sharing and DNA cryptography to exchange parameters securely. The security analysis of the proposed scheme is evaluated by theoretical analysis. Formal analysis of the proposed protocol is done using Scyther and all the modelled claims are validated and positive results are obtained. Copyright 2021 Inderscience Enterprises Ltd. -
Secure medical sensor monitoring framework using novel optimal encryption algorithm driven by Internet of Things
Recently, healthcare monitoring systems have emerged as significant tolls for constant monitoring of patient's physiological characteristics. These systems use implanted sensors. IoT (Internet of Things) have revolutionized healthcare systems where health care equipment's are equipped with many sensors that actively collect data from patients and pass it on to cloud based storages using gateway sensors. Securing data have been significant barriers in many applications as false information get injected, or important information are modified or stolen at different phases of health care systems dependent on IoT. The attacks can also result in fatalities making it imperative to secure IoT based health care systems. A Hybrid technique combining MOAES (Modified Optimal Advanced Encryption Standard) with CM (Chaotic Map) Encryptions called HMOAES-CM technique is proposed. This technique can be helpful in securely accessing the patient data over online mode, and in addition, the data sharing can be performed in an encrypted form for the necessary targets of stakeholders. The proposed authentication approach is aimed at IoT, which is resilient to all kinds of network attacks and its implementation is also simpler. Comparing the suggested work to similar works, the level of evaluation is much improved. 2023 The Authors -
Secure provenance-based communication using visual encryption
Explicit specification of the historical record of an instance or a data item is called data provenance. It has many applications in various fields with regards to its importance on capturing data flow mechanisms. However, on the other hand, there are good number of security mechanisms in place to withstand the cyber-attacks. Almost all of these algorithms uses complex mathematical calculations in providing security for the systems. Visual cryptography is a peculiar approach which uses concept of secret sharing by dividing the message into transparencies as encryption process. Upon superimposing transparencies one obtains the original message. In this paper, we propose secret sharing as a notion of security onto data provenance. Main inference of this writing is to throw a model combining above two mentioned aspects which gives away an indigenous solution in the area of information security. This proposed model is implemented with specific use case scenarios for substantiation and related analysis. Simulated results and discussion of the same is presented in the paper. 2019 Inderscience Enterprises Ltd. -
Secure Through Development: Evaluation of Indias Border Area Development Programme
The Border Area Development Programme was initiated in the year 198687, to strengthen Indias security by ensuring developed and secure borders. Initially, the programme was implemented in the western border states to facilitate deployment of the Border Security Force. Later, the geographical and functional scope of the programme was widened to include eastern and northern sectors of Indias borders and as well as socio-economic aspects such as education, health, agriculture and other allied sectors. But, it is difficult to say that the implementation has been uniform in all the sectors. While the programme on the Western front along the IndiaPakistan border has been fairly successful, it is yet to achieve its stated objectives on the Eastern front. Using an analytical framework, the article examines three aspects of BADP: Its context and concept; identifying challenges that hinder the Programmes effectiveness; and certain policy prescriptions. 2019, 2019 Institute for Defence Studies and Analyses. -
Secure visual cryptography scheme with meaningful shares
Visual cryptography is an outstanding design, which is also known as visual secret sharing. It used to encode a secret portrait into various pointless share images. Normally, item bossed on transparencies and decrypts as loading one or two or the entire share images by means of the human visual system. Suppose, if we encompass great sets of secret shares then the pointless shares are complicated to handle. In this paper, a meaningful secret sharing algorithm and a modified Signcryption algorithm is used to enhance the security of the Visual Cryptography encryption schemes. The foremost intend of the anticipated format is to extend consequential shares and similarly make sure the isolation on conveying the secret data. The anticipated process is executed in the functioning platform of MATLAB and the presentation results are investigated. 2020, Engg Journals Publications. All rights reserved.