Browse Items (16488 total)
Sort by:
-
Distributed DoS Detection in IoT Networks Using Intelligent Machine Learning Algorithms
The threat of a Distributed Denial of Service (DDoS) attack on web-based services and applications is grave. It only takes a few minutes for one of these attacks to cripple these services, making them unavailable to anyone. The problem has further persisted with the widespread adoption of insecure Internet of Things (IoT) devices across the Internet. In addition, many currently used rule-based detection systems are weak points for attackers. We conducted a comparative analysis of ML algorithms to detect and classify DDoS attacks in this paper. These classifiers compare Nave Bayes with J48 and Random Forest with ZeroR ML as well as other machine learning algorithms. It was found that using the PCA method, the optimal number of features could be found. ML has been implemented with the help of the WEKA tool. 2021 IEEE. -
Distributed denial-of-service detection and mitigation using software-defined network and internet of things
Internet of Things (IoT) is one of the promising technologies that are developing quickly in various fields such as automation, safety and health. It is a heterogeneous network that links various physical devices. It consists of a variety of vulnerabilities due to its heterogeneous nature. It makes a different level of security issues. Distributed Denial-of-service (DDoS) attack denies services to an authentic user and makes the resources of network inaccessible. DDoS attack is a significant problem for IoT. It is easy to carry out this attack on an IoT network. Main aim of the proposed methodology is to use Software-defined Network (SDN). The primary structure of proposed system is to integrate SDN and IoT technology. This combination is to provide a more secure infrastructure compare to traditional system. The secondary structure of proposed system is used to detect and mitigate the DDoS attacks. The proposed methodology is to check associativity of MAC IP address, source IP address and destination IP address. It was able to detect and mitigate the attack in short span of time. The results are compared on different parameters. That parameters are packet delay time, flow entries and average packet received per second by the controller. This hybrid method is to provide higher security and improve the Quality of Service (QoS). 2019, Institute of Advanced Scientific Research, Inc.. All rights reserved. -
Distillery effluent valorization through cost effective production of polyhydroxyalkanoate: optimization and characterization
The devastating effect of fossil plastics in the biosphere has tuned the concern for bioplastic production in the last few decades. Polyhydroxyalkanoate, a biopolyester, has a wide range of applications as they impose positive societal impact by being biodegradable and void of any ill-effects when used in vivo. Despite their eco-friendly nature, the outreach of PHA is bounded in industrial scale as the overall expense is highly comparable to conventional plastics. Therefore, in an attempt to attain a feasible production, the present study aims at utilizing raw distillery effluent for PHA production using Bacillus subtilis NCDC 0671. Different dilutions of spent wash (5%, 10%, 15%, and 20%) were assessed for PHA production in the modified medium among which 10% showed maximum PHA accumulation. Furthermore, statistical optimization by response surface methodology enhanced PHA synthesis to 6.3g/L which is 3.3-fold increases. FTIR and NMR characterization of the biopolymer from the optimized medium was similar to the previous literature which provides a promising approach for cost effective production. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature 2022. -
Distillery effluent valorization through cost effective production of polyhydroxyalkanoate: optimization and characterization
The devastating effect of fossil plastics in the biosphere has tuned the concern for bioplastic production in the last few decades. Polyhydroxyalkanoate, a biopolyester, has a wide range of applications as they impose positive societal impact by being biodegradable and void of any ill-effects when used in vivo. Despite their eco-friendly nature, the outreach of PHA is bounded in industrial scale as the overall expense is highly comparable to conventional plastics. Therefore, in an attempt to attain a feasible production, the present study aims at utilizing raw distillery effluent for PHA production using Bacillus subtilis NCDC 0671. Different dilutions of spent wash (5%, 10%, 15%, and 20%) were assessed for PHA production in the modified medium among which 10% showed maximum PHA accumulation. Furthermore, statistical optimization by response surface methodology enhanced PHA synthesis to 6.3g/L which is 3.3-fold increases. FTIR and NMR characterization of the biopolymer from the optimized medium was similar to the previous literature which provides a promising approach for cost effective production. 2022, The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature. -
DISTANCE SPECTRUM OF TWO FAMILIES OF GRAPHS
Let H1 and H2 be two copies of the complete graph Kn, n ? 3 with vertex sets V(H1) = {v1,v2...,vn} and V(H2) = {u1,u2,...,un}. Graph ?(n,p), 1 ? p ? n-1, is obtained from the union of graphs H1 and H2 by adding edges {uivi)|i ? {1, 2...,p}}. Graph ?(n) is obtained from the union of graphs H1 and H2 by joining each vertex vi of H1 to every vertex in {u1, u2, ..., un} \ {ui}, i = 1, 2, ..., n. The adjacency spectrum of ?(n, p) and ?(n) were determined in [9]. An open problem posed in [7] was to find families of graphs of diameter greater than two, for which the adjacency and distance spectrum are both integral. To answer the open problem, the distance spectrum of the above family of graphs is calculated, and new distance equienergetic graphs are constructed in this paper. 2024 Jangjeon Research Institute for Mathematical Sciences and Physics. All rights reserved. -
Distance based properties of the semi splitting block graph of graph
The bounds on the radius and diameter of the semi splitting block graph (SB(G)) of graphs are investigated. The diametral paths and self-centeredness of semi splitting block graph of any connected graph are analyzed. The graphs where the diameter of G and SB(G) are the same are characterized and the number of blocks in the diametral path of such graphs is analyzed. 2023 Author(s). -
Dissecting the Dichotomy of Skill and Social Justice Theory of Law School Legal Aid Clinics in the USA and India: A Re-look of the Past and the Present
With the mushrooming of legal aid clinics across institutions imparting legal education, there exists a conundrum as to their actual objectives. With passage of time, social justice theory is losing ground and skill development theory has gained greater predominance. In order to understand the objectives behind establishing legal aid clinics, the article traces its inter-linkages with the theory of social justice. In doing so, an analysis of the context under which legal aid clinics were established and their relevance to the present day is explored through the article. With the passage of 22 years of establishment of law school legal aid clinics in India, there still exists a dichotomy as to their real purpose and objective. These models of legal aid clinics of the past not only offer insights to develop present models of legal aid clinics, but there is also a need to emulate these models as they are relevant and apt even to this day. The article adapts a comparative approach between India and the USA, chronicling the past and present sojourns of the journey of law school legal aid clinics and the suitability of the social justice theory to the current Indian context. 2021 The West Bengal National University of Juridical Sciences. -
Dissecting star formation in the "atoms-for-Peace" galaxy: UVIT observations of the post-merger galaxy NGC7252
Context. The tidal tails of post-merger galaxies exhibit ongoing star formation far from their disks. The study of such systems can be useful for our understanding of gas condensation in diverse environments. Aims. The ongoing star formation in the tidal tails of post-merger galaxies can be directly studied from ultraviolet (UV) imaging observations. Methods. The post merger galaxy NGC7252 ("Atoms-for-Peace" galaxy) is observed with the Astrosat UV imaging telescope (UVIT) in broadband NUV and FUV filters to isolate the star-forming regions in the tidal tails and study the spatial variation in star formation rates. Results. Based on ultraviolet imaging observations, we discuss star-forming regions of ages <200 Myr in the tidal tails. We measure star formation rates in these regions and in the main body of the galaxy. The integrated star formation rate (SFR) of NGC7252 (i.e., that in the galaxy and tidal tails combined) without correcting for extinction is found to be 0.81 0.01 M yr-1. We show that the integrated SFR can change by an order of magnitude if the extinction correction used in SFR derived from other proxies are taken into consideration. The star formation rates in the associated tidal dwarf galaxies (NGC7252E, SFR = 0.02 M yr-1 and NGC7252NW, SFR = 0.03 M yr-1) are typical of dwarf galaxies in the local Universe. The spatial resolution of the UV images reveals a gradient in star formation within the tidal dwarf galaxy. The star formation rates show a dependence on the distance from the centre of the galaxy. This can be due to the different initial conditions responsible for the triggering of star formation in the gas reservoir that was expelled during the recent merger in NGC7252. 2018 ESO. -
Disruptive Technology and Performance of Manufacturing SMEs as Moderated by Technological Innovation in South-West Nigeria
The manufacturing sector is critical and significant to economic growth, offering dynamic benefits for industrial transformation. However, many manufacturing small- and medium-sized enterprises (SMEs) face challenges such as limited capacity and technical expertise, leading to reduced profitability, market share (MS), and overall business performance. In todays competitive business environment, these SMEs are particularly vulnerable to the effects of disruptive technology (DT), which poses both challenges and opportunities. This study examined the impact of DT on the performance of selected manufacturing SMEs in Lagos and Ogun States, Nigeria, with technological innovation (TIN) as a moderating factor. A survey research design was employed, targeting a population of 2, 603 manufacturing SMEs (504 in Ogun State and 2, 099 in Lagos State). Using Cochrans formula, a sample size of 436 was determined, and stratified random sampling was used to select respondents. Data were collected through a structured questionnaire, yielding an 88.3% response rate. Descriptive and inferential statistical analyses revealed that DT significantly influenced SME performance, with TIN strengthening this relationship (adjusted R2 = 0.913, 0.932, and 0.935 across models, p < 0.05). The findings suggested that adopting DT is significant for improving the long-term performance of manufacturing SMEs. It is recommended among others that management should prioritize the integration of DT components to enhance overall business outcomes and competitiveness. 2026 Olamide Titilayo Ayodeji, Timilehin Olasoji Olubiyi, Titilayo Doris Ibikunle, Israel Olabode Aroge and Abiodun Richard Obisanya -
Disrupted Diners: Impacts of COVID-19 on Restaurant Service Systems and Technological Adaptations
Measures such as lockdowns and social distancing may have effectively controlled the pandemic, but they have a tremendous detrimental effect on businesses relying heavily on face-to-face communications such as the restaurant and dine-in industry. With the current COVID-19 pandemic, the restaurant and dine-in places had to face the brunt of losing customers due to government-mandated public health measures. The restaurant sector had to look for an overhaul immediately as the disruptions caused by the pandemic has pushed them either on the verge of closure or bad financial health. Nevertheless, an upsurge of technological advancements has come as a lender of last resort to the restaurant industry. This chapter presents the major disruptions caused by the pandemic in the in-person dining sector. It also sheds light on the various methods shaping the future of the restaurant industry. Finally, the chapter deals with the different prospects and challenges awaiting the paths of transformation and draws a framework called The Dining Spectrum as a contribution to the existing literature. The Editor(s) (if applicable) and The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd. 2022. -
Disproportionate impact of climate change: Housing crisis and displacement among the transgender community in India
India is a nation that is threatened by climate change. Climate change and the housing crisis are inextricably linked, they are associated with exacerbated mental and physical health conditions. It often affects individuals differently based on various factors shaped by social norms. So, marginalized sections like transgender persons are disproportionately affected. Individuals with inadequate housing are significantly affected by natural disasters. However, most transgender individuals cannot rent due to a lack of documents and unemployment. Thus, housing is an essential social determinant of physical and mental health. The book chapter discusses the various intersecting identities and the geographical and ecological contexts. The current revised climate laws in India have emphasized incorporating gender but there is a need to focus on gender beyond the binary to formulate more sensitive and equitable methods to address climate change. It also discusses the psycho-social impact on the community and the unique challenges they face as extreme weather events increase. 2024, IGI Global. All rights reserved. -
Dispositional Mindfulness and Perceived Stress in Psychiatric and Nonpsychiatric Physicians: A Facet-level Pilot Study
OBJECTIVES: Perceived stress is a significant concern among health care professionals, with potential consequences for mental health and clinical performance. This study examined associations between dispositional mindfulness and perceived stress among Indian physicians working in psychiatric and nonpsychiatric specializations within hierarchical systems with limited institutional support. METHODS: In this cross-sectional pilot study, 62 clinicians (39 nonpsychiatric and 23 psychiatric physicians) completed the Perceived Stress Scale and the Five Facet Mindfulness Questionnaire-Short Form. Independent samples t tests compared perceived stress and mindfulness scores between the groups. Correlations and linear regression analyses were conducted to examine relationships between mindfulness and perceived stress. RESULTS: No statistically significant differences were found between psychiatric and nonpsychiatric physicians in perceived stress, t(59)=0.98, P=0.329, d=0.27, or total mindfulness, t(59)=-1.31, P=0.186, d=0.35. Across the sample, higher dispositional mindfulness was strongly associated with lower perceived stress, r(60)=-0.65, P<0.001, r=0.43, particularly for the Describe and Acting with Awareness facets. Linear regression indicated that mindfulness was significantly related to perceived stress, ?=-0.65, t=-6.66, P<0.001, accounting for 42.5% of the variance. CONCLUSIONS: These findings cautiously suggest that dispositional mindfulness may serve as a potential psychological resource for stress regulation and burnout prevention among clinicians. Further research is warranted to validate these associations in larger and more diverse samples and to explore practical applications within wellness initiatives. Copyright 2026 Wolters Kluwer Health, Inc. All rights reserved. -
Dispersion Analysis of Love-Type Waves in a Multilayered Piezomagnetic-Heterogeneous Structure with a Viscous Liquid Layer
Abstract: Purpose. This paper examines Love-type wave transmission in a multilayered piezomagnetic (PM) and heterogeneous half-space (HHS) structure with a viscoelastic layer (VL) on top. Wave transmission behaviour is examined in magnetically open (MO) and magnetically closed (MS) circuit boundary conditions. The main study focuses on the dispersion behaviour of phase velocity of a Love-type wave influenced by the combination of VL, PM and HHS. Methods. : The dispersion relation for Love-type waves was determined analytically, and phase velocity graphs were plotted and analysed using numerical simulations with Mathematica software. A comprehensive study was conducted to acquire the effects of significant variables on phase velocity, including material heterogeneity, piezomagnetic coupling, and viscoelastic layer thickness. Findings. : The research results show the attenuation properties of the VL, PM, and HHS materials in MO and MS situations. Graphical comparisons show that piezomagnetic coupling caused the phase velocity curves to alter regularly, indicating its importance in wave propagation. The open and short circuit situations had nearly identical phase velocity, demonstrating that boundary limitations have little effect on how waves propagate. Research limitations. : The model is limited to linear wave transmission and ignores nonlinear effects. Furthermore, the approach is based on idealized material qualities, which account for heterogeneity. Practical Implications. : The studys findings can help build and improve energy harvesters, sensors, and wave manipulation instruments that use PM with viscoelastic coatings. Understanding the behaviour of surface waves is required for effective use in these structures. Novelty. : This article investigates Love-type surface wave transmission in a VL-PM-HHS composite structure that includes a viscoelastic layer, piezomagnetic material, and a heterogeneous half-space. Itexplores how material heterogeneity, piezomagnetic coupling, and viscoelastic attenuation affect phase velocity under magnetic circumstances. Pleiades Publishing, Ltd. 2025. -
Disorders in graphene: types, effects and control techniquesa review
The development of graphene and graphene-like materials has been a breakthrough in the field of nanotechnology for its exceptional properties. It exhibits extraordinary properties owing to its unique, regular arrangement of carbon atoms in it. However, graphene is usually modified for specific applications, by introducing disorder in the system. Since disorders are ubiquitous during the synthesis of graphene and graphene-like materials, it is best to exploit the defects for tuning its exceptional properties for suitable device applications. Like in any material, the disorder can drastically affect the properties, and hence they are deliberately incorporated into the material. In this review, we discuss topics related to the creation and configuration of disorders in graphene such as corrugations, topological defects, vacancies, adatoms and sp3-defects. The effects of these disorders on the electrical, thermal, chemical and mechanical properties of graphene are analysed subsequently. Finally, we review earlier works on the modulation of structural defects in graphene for specific applications. 2021, Korean Carbon Society. -
-
Dislocation and microindentation analysis of vapour grown Bi 2Te3-xSex whiskers
The structural defects and microhardness of Bi2Te 3-xSex whiskers (x = 0, 0.2 and 0.4 at % Se) grown by physical vapour deposition (PVD) method have been investigated. Concentric pairs of dislocation loops were observed on the as-grown surfaces of short hexagonal prisms. A systematic study of dislocations in these crystals was carried out by chemical etching technique. The effects of Se doping, annealing and quenching on the mechanical properties have also been studied on the prism faces of Bi 2Te3-xSex whiskers. 2008 WILEY-VCH Verlag GmbH & Co. KGaA. -
Disentangling the two sub-populations of early Herbig Be stars using VLT/X-shooter spectra
Context. Early Herbig Be (HBe) stars are massive, young stars accreting through the boundary layer mechanism. However, given the rapid (<2 Myr) evolution of early Herbig stars to the main-sequence phase, studying the evolution of the circumstellar medium around these stars can be a cumbersome exercise. Aims. In this work, we study the sample of early (B0-B5) HBe stars using the correlation between H? emission strength and near-infrared excess, complemented by the analysis of various emission features in the X-shooter spectra. Methods. We segregate the sample of 37 early HBe stars based on the median values of H? equivalent width (EW) and near-infrared index (n(J-H)) distributions. The stars with |H? EW| > 50and n(J-H) > -2 are classified as intense HBe stars and stars with |H? EW| < 50and n(J-H) < -2 as weak HBe stars. Using the VLT/X-shooter spectra of five intense and eight weak HBe stars, we visually checked for the differences in intensity and profiles of various HI and metallic emission lines commonly observed in Herbig stars. Results. We propose that the intense HBe stars possess an inner disk close to the star (as apparent from the high near-infrared excess) and an active circumstellar environment (as seen from the high H? EW value and presence of emission lines belonging to FeII, CaII, OI, and [OI]). However, for weak HBe stars, the inner disk has cleared, and the circumstellar environment appears more evolved than for intense HBe stars. Furthermore, we compiled a sample of ~58 000 emission-line stars published in Gaia DR3 to identify more intense HBe candidates. Further spectroscopic studies of these candidates will help us to understand the evolution of the inner (approximately a few au) disk in early HBe stars. The Authors 2023. -
Disentangling the association of PAH molecules with star formation
Context. Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous complex molecules in the interstellar medium and are used as an indirect indicator of star formation. On the other hand, the ultraviolet (UV) emission from young massive stars directly traces the star formation activity in a galaxy. The James Webb Space Telescope (JWST), along with the UltraViolet Imaging Telescope (UVIT), opened up a new window of opportunity to better understand the properties of PAH molecules that are associated with star-forming regions. Aims. We investigate how the resolved scale properties of PAH molecules in nearby galaxies are affected by star formation. Methods. We analyzed the PAH features observed at 3.3, 7.7, and 11.3 m using F335M, F770W, and F1130W images obtained from the JWST. These images helped us identify and quantify the PAH molecules. Additionally, we used UVIT images to assess the star formation associated with these PAH-emitting regions. Our study focused on three galaxies, namely NGC 628, NGC 1365, and NGC 7496, which were selected based on the availability of both JWST and UVIT images. Bright PAH emission regions were identified in the JWST images, and their corresponding UV emission was estimated using the UVIT images. We quantified the star formation properties of these PAH emitting regions using the UVIT images. Furthermore, we investigated the relation between the star formation surface density (?SFR) and the PAH ratios to better understand the impact of star formation on the properties of PAH molecules. Results. Based on the resolved scale study of the PAH-bright regions using JWST images, we found that the fraction of ionized PAH molecules is high in the star-forming regions with high ?SFR. We observed that emission from smaller PAH molecules is higher in star-forming regions with higher ?SFR. Conclusions. Our study suggests that the PAH molecules excited by the photons from star-forming regions with higher ?SFR are dominantly smaller and ionized molecules. UV photons from the star-forming regions could be the reason for the higher fraction of the ionized PAHs. We suggest that the effect of the high temperature in the star-forming regions and the formation of smaller PAH molecules in the star-forming regions might also result in the higher emission in the F335MPAH band. The Authors 2024. -
Disentangling homeowner motives for solar PV: Psychometric development, validation and invariance test of the Motivation for Rooftop Solar Adoption Scale
The rooftop photovoltaic (PV) adoption of households is shaped by heterogeneous motives of the household that extend beyond economic calculus, yet prior research often measures these motives using ad hoc or single-item indicators, limiting comparability across studies. This study develops and validates the Motivation for Rooftop Solar Adoption Scale (MRSAS) to disentangle the key motivational dimensions that drives the household PV adoption. Following established scale-development guidance, we generated an initial item pool from theory and recent PV-adoption evidence, assessed content adequacy using a structured Q-sort, and then conducted exploratory factor analysis (N = 295), followed by confirmatory factor analysis (N = 312). Results support a parsimonious 22 item six-factor model with Social Influence, Financial Motivation, Environmental Protectionism, Energy Self-Reliance, Facilitating Conditions, and Technophile Attitude as dimensions. The model exhibits excellent confirmatory model fit along with strong reliability and discriminant validity. Multi-group CFA establishes scalar invariance between adopters and non-adopters, aligning with theory, adopters score higher across all six motivational dimensions. The MRSAS provides a psychometrically robust and transferable tool for profiling why households adopt solar, supporting cumulative theory-building and enabling practitioners to tailor incentives, communication and programme design to the motivations that matter. 2026 The Authors. -
Diseased Leaf Identification Using Bag-of-Features and Sigmoidal Spider Monkey Optimization
Agricultural products decide the economy of a country like India. The agricultural business has the involvement of a large population. The quality and quantity of agricultural products highly depend on environmental conditions and facilities provided to farmers. Timely and efficient detection of diseases in plants and crops is one of the most critical issues that affect crop production. Therefore, it is highly desirable to develop some cheap and easy-to-handle automated plant disease detection systems for the timely treatment of plants. Leaves are considered a primary source of information about the health of plants. In the case of plants, the disease may be easily visualized and identified by observing its effect on leaves. Therefore, this paper introduces a bag-of-features in sigmoidal spider monkey optimization to identify a diseased leaf, separating the diseased leaf from a healthy leaf. The investigational outcomes show the superiority of the anticipated technique in contrast to other meta-heuristic-based systems. The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd 2024.