Browse Items (472 total)
Sort by:
-
Multi-Objective Optimization Approaches for Solar Photovoltaic Inverter Control and Energy Balance in A Smart Grid Environment
Placement of distributed generation in electrical distribution system is a critical newlineaspect of optimizing grid performance and ensuring effcient integration of renewable energy sources. Renewable based sources must be properly positioned and sized to avoid bidirectional power and#64258;ows, voltage/frequency and#64258;uctuations and performance degradation. Solar Photovoltaic Systems and Wind Turbines are potentially becoming the preferred renewable energy based, distribution generation sources. Precise control mechanisms like advanced inverter strategies and direct load control are crucial for regulating voltage, frequency and reactive power output, thereby optimizing grid operation and maximizing integration benefts from these sources. However, optimizing the allocation and operation of these systems in grid connected and islanded modes, particularly in radially confgured systems, requires addressing algorithmic challenges, problems related to nonlinear optimization, newlinevariable generations and load variations. To effectively allocate these systems in the newlineelectrical distribution system, advanced optimization techniques capable of newlinehandling multi-objective, nonlinear problems are needed. Similarly, optimizing the power factor of the distributed generation sources and optimizing the load factor in these systems demand adaptive algorithms that can manage nonlinear objectives and dynamic system conditions. In response to the above research questions, this study focuses on determining the optimal placement and sizing of the distributed generation sources in the electrical distribution system with the objective to minimize real power loss and improve voltage stability. Learning enthusiasm based teaching learning based optimization algorithm has been employed for location selection and sizing optimization. The effectiveness of the proposed approach is validated on standard IEEE 33-bus and newline69-bus test systems, demonstrating decreased distribution losses and improved voltage stability. -
Vanet Framework for Optimal Target Selection in Handoff using machine Learning
The impact of mobile networking has been far-reaching and has transformed many technologies for the better. Among the more pioneering technologies of recent times, autonomous vehicles (AV) are being touted as the future of transportation. AVs are featured prominently due to their ability to provide services across the implementations concerning smart-city applications. Since the newlinenodes (AV) involved are highly mobile, it is important to keep the device connected and adapt the dynamic topology change. The network should be capable of switching AV between access points (AP s) dynamic and must take place without much delay. Handoff is the process where a node switches between APs depending on the changes in the network topology. Various studies have claims that the use of Machine Learning or Deep Learning improves the efficiency of decision making in mobile networks. In this research work a dynamic handoff framework, inspired by the traditional Indian game of Kho-Kho is proposed. It selects the most optimal AP for newlinecommunication in a mobile environment. Initially the nodes within an AP are newlinecategorized as sticking and steering nodes. Identifying the nodes list for executing newlinethe Kho-Kho based handoff for the steering nodes. The framework makes use of Artificial Neural Networks (ANN) to perform the operation of handoff and selects the most optimal AP once the handoff trigger occurs. ANN is designed for multiple parameters, including signal strength, noise, and direction to make its decisions regarding handoff. The proposed Kho-Kho model has been newlineimplemented and analyzed using the NS3 simulator. Simulation results have indicated a higher performance of the proposed Kho-Kho approach when compared to the existing standard implemented for vehicular ad hoc newlinecommunications in IEEE -
Impact of Heavy Metals on Growth and Biosynthesis of Important Secondary Metabolites from Mucuna Pruiens (L.) DC and Withania Somnifera (L). DUNAL
Herbal medicine has a long history of utilizing medicinal plants to treat various newlineailments for a long time. However, heavy metal toxicity in herbal medicines has been newlinedocumented. The occurrence of heavy metals in medicinal plants is a consequence of exposure to tainted agricultural sources. The consumption of medicinal plants newlinecontaminated with heavy metals has caused detrimental health implications. On the newlineother hand, plants when subjected to heavy metal stress exhibit changes in secondary newlinemetabolite production. Thus, the assessment of heavy metal stress on plant growth, newlinesecondary metabolite production, and its bioaccumulation must be worked on. The newlinepresent study investigates the effect of heavy metals such as lead, cadmium and newlinemercury on germination, growth, biochemical variations, heavy metal accumulation, newlineand biosynthesis of secondary metabolites in two of the most valuables ayurvedic newlinemedicinal plants Mucuna pruriens (L.) DC and Withania somnifera (L). Dunal. The M. pruriens seeds were exposed to 25 -250 ppm Cd and Hg and 200-2000 ppm Pb and the seeds of W. somnifera were exposed to 20-200 ppm Cd, 10-100 ppm Hg and 100-1000 ppm Pb for 21 days to evaluate the LD50 value. M. pruriens showed 50% germination at 150 ppm Cd, 175 ppm Hg, and 1200 ppm Pb. W. somnifera showed newline50% germination at 70 ppm of Hg, 140 ppm Cd and 400 ppm Pb. The LD50 value obtained was used to select the appropriate Cd concentrations for further studies to newlinebe carried out in the polyhouse. The seeds of M. pruriens were sown in soil pretreated newlinewith metals ranging from 50-200 ppm Cd, 25-225 ppm Hg and 400- 1600 ppm Pb, newlinewhereas the two months old W. somnifera were exposed to 40-200 ppm Cd, 20-100 ppm Hg and 200-1000 ppm Pb. The heavy metals impacted the growth of plants and significantly varied biochemical parameters, such as carbohydrate, chlorophyll, flavonoid, protein, proline, phenol, MDA content, metabolite content, and newlineantioxidant activity. -
Biomarkers of Autistic Study : Biochemical, Genomics, Epigenetics and Cytogenetic Signatures
Autism is a complex disorder characterized by social issues, impaired communication, newlineand repetitive behavior. The prevalence of autism has increased significantly over the past two decades, with an estimated incidence of 1 in 150 children in 2000. Cytogenetic investigations are essential for confirming clinical diagnoses, as the disorder has high phenotypic variability and genetic heterogeneity. A study aims to confirm behavioral phenotypes of autistic subjects newlinein South India using DSM IV and ATEC open questionnaires. The study found that metabolic factors, including hormones, neurotransmitters, and oxidative ions, play crucial roles in the progression of symptoms. The study also revealed the roles of two major causative genes (NRXN1 and CNTNAP2) in a spectrum of genotypes imparting severity and heterogeneity. -
Effect Of Cooperative Learning Strategies on Self-Directed Learning and Reflective Thinking of Pre-Service Teachers
Cooperative learning (CL) research demonstrates its robustness. While acknowledging the empirical benefits, there is room for improvement in implementing CL in teacher education classrooms. Teacher educators often resist adopting CL, favouring the frontal teaching method. The cultivation of self-directed learning and reflective newlinethinking is crucial for pre-service teachers (PSTs) to evolve into lifelong learners, newlinemeeting the demands of 21st-century classrooms. Online cooperative learning (OCL) newlineplays a vital role in enhancing essential skill sets such as collaboration, digital newlineproficiency, communication, and interaction among pre-service teachers. This study newlineunfolded in two phases. The initial pilot study, utilizing a concurrent triangulation newlinemixed-method research design, delved into perceived challenges faced by teacher newlineeducators in India regarding cooperative learning implementation. The subsequent newlineexperimental stage employed a quasi-experimental non-equivalent control group newlinedesign to investigate the impact of OCL strategies on self-directed learning (SDL) and reflective thinking (RT) among Indian pre-service teachers. Following the newlineintervention with OCL modules, the researcher also assessed pre-service teachers newlinesatisfaction and perceptions towards OCL, utilizing a mixed-method research approach with concurrent triangulation. The sample for experimental stage encompassed 130 pre-service teachers from two teacher education colleges affiliated with Mangalore University, Karnataka, India. The researcher constructed OCL intervention modules for the study and experts validated it. The researcher adopted standardized instrument for measuring SDL by Acar et al. (2016), and standardised instrument for measuring RT by Kember et al. (2000). The pilot study revealed that teacher educators perceived challenges at an average rate of 63% due to teacher challenges, learner challenges, curriculum syllabus, and administrative challenges. -
Study of Low-Mass Stars and Brown Dwarfs In Star Forming Regions of Diverse Environments
The formation and evolution of low-mass stars and brown dwarfs is an intricate process orchestrated by the environmental conditions in which they form. As a natural byproduct of this process, circumstellar disks are formed, whose dynamic relationship with the environment plays a pivotal role in determining the fate of the star and the timescale for planet formation. While low-mass stars are a dominant product of the star formation process, brown dwarfs occupy a unique position, bridging the gap between newlinelow-mass stars and planets. In this thesis, we have examined the low-mass stars and brown dwarfs in young clusters located at different distances with diverse UV radiation felds and stellar densities to decode the role of environment in shaping the IMF, its inand#64258;uence on disk evolution and to understand the formation of brown dwarfs. We have targeted three young star forming regions for the newlinestudy namely and#963; Orionis, twin clusters IC 1848-East and West, and IC 1396 using deep multi-wavelength photometry as well as near-IR spectroscopy with 4m and 10m class facilities. For the and#963; Orionis cluster we used deep CFHT-WIRCAM near-IR data and the novel water-band photometry technique along with Gaia DR3 to identify the candidate low-mass members. Spectroscopic follow-up observations conducted with IRTF-SpeX validated the selection of the candidates by this technique with a 100% effcacy. We then compiled a comprehensive membership catalog for a mass range and#8764;19-0.004 Mand#8857;. The form of the stellar-substellar IMF was found to be consistent with other nearby star forming regions suggesting a lack of signifcant environmental inand#64258;uence. Further, we analysed the evolutionary class of the members based on the mid-IR slope of the SED to study their disk properties. We estimated the disk fraction of the low-mass sources to be consistent with other star form ing regions considering the age of the cluster. This showed that in this region, external photoevaporation does not play a major role in the inner disk evolution. -
Friction Stir Welding Process Parameters Optimization By Taguchi Analysis and Validating The Mathematical Model Using RSM For AA6101-C11000 Alloy Joints
Friction Stir Welding (FSW) is a well-established joining method that offers newlinesignificant advantages over traditional methods, including improved mechanical newlinecharacteristics, less distortion, and environmental friendliness. Due to its solid-state nature, the heat produced through the welding mainly influences the features of joints in FSW. In this investigation, 2D and 3D models of the base metals and welding tool newlinewith different pin profiles were designed using SOLIDWORKS. Fixture was designed and manufactured in accordance with the specifications of the welding machine. ANSYS software was used to investigate the temperature distributions near the weld newlinezones. The base metals AA6101 and C11000 of each 5 mm thickness with butt weld newlinepositioned, were joined by FSW mechanism with the help of OHNS steel tool with circular pin profile. Taguchi analysis was employed to optimize the FSW welding input process parameters, including tool rotational speed (rpm), feed rate (mm/min), and tool offset (mm), to determine their respective contribution (%) to the output response, namely ultimate tensile strength (UTS), hardness, impact load, and electrical newlineconductivity to achieve the high joint strength. During experimental work using the newlineTaguchi s design matrix, the maximum output response values were obtained when the input parameters were set to 1000 rpm, 50 mm/min and -1 mm. Taguchi analysis revealed that the tool rotational speed encounters high significance effects, followed by feed rate and least tool offset upon output response. The X-ray diffractometer (XRD) test was employed to specifically determine the existence of Al-Cu intermetallic compounds (IMCs) generated within the FSW of Al (AA6101) and Cu (C11000) joints. At medium 40 mm/min, 1000 rpm, and -1.68 mm, the IMCs newlinedeveloped were Al4Cu9 and Al1Cu3 giving a high UTS value of about 142.69 MPa. newlineMathematical model was developed utilizing the Response Surface Method (RSM) to newlinepredict the output response. -
Large Scale Transportation Data Analysis and Distributed Computational Pipeline for Optimal Metro Passenger Flow Prediction
Transportation has a signifcant impact on controlling traffc around a busy city. Among the transport system, metro rails became the backbone by operating above the traffc. For this reason, we have to take special consideration of the passenger and#64258;ow in the transport system and, by understanding the needs, take timely actions for smooth running. Every metro system stores information about the and#64258;ow of passengers in the form of transactions known as Automatic Fare Collection (AFC) data. For this research, AFC data is taken as the primary newlinesource of information to identify the passenger and#64258;ow within the metro rail platform. Each metro system generates massive data throughout its running period and stores data within the system and considering the size of data generated, the analytic platform has to process them in a distributed paradigm to handle quotBig Dataquot. Artifcial Intelligence (AI) algorithms can derives information, insights, and patterns from this data. The patterns in time series can be identifed from the passenger and#64258;ow data using exploratory analysis. The step is an essential step in data science for understanding the underlying properties of the raw data. The research uses a data platform with a distributed computing and storage mechanism called the JP-DAP. The research leverages the above mentioned platform to extract passenger and#64258;ow data from AFC Ticketing data. After the data engineering, the results of passenger and#64258;ow information underwent further visualization and trend analysis. Based on the facts or patterns identifed from the passenger and#64258;ow information, a decision is taken for forecasting. The initial study will reveal the characteristics of metro usage and practices within the system and fnally derive a solution with machine learning-based forecasting method. The passenger and#64258;ow newlineforecasts based on the above patterns depend on factors like seasonality, trends, cyclicity, location, events, and random effects. -
Opportunity Recognition, Career Decision-Making, Self-Efficacy and Social Entrepreneurial Intention among Higher Education Students
Building on the entrepreneurship cognition literature, the present research aims to develop a model to examine the direct and indirect effects of opportunity recognition, career decisionmaking and self-efficacy on social entrepreneurial intention. The research adopted a crosssectional design. The research was divided into three distinct studies, each conducted with a specific objective. The data collected for three studies included higher education students newlineacross India. Studies 1 and 2 aimed to develop and validate two scales, namely social entrepreneurial opportunity recognition and social entrepreneurial career decision-making following steps in tool construction. The sample size was 600 for study 1 and 845 for study 2. The social entrepreneurial opportunity recognition scale had 24-items that measures opportunity recognition with six motivating factors as the lower order constructs which are life experiences, social awareness, social inclination, community development, institutional voids, and natural option for a meaningful career. The social entrepreneurial career decision scale had 20 items focusing on the appraisal components in pre-entry social entrepreneurial career decision-making and has four factors, which are relevance, coping potential, knowledge and resources, and normative significance. Study 3 examined the direct and indirect effects of opportunity recognition, career decision-making and self-efficacy on social newlineentrepreneurial intention using a sample of 605 students. The findings show that opportunity recognition influences social entrepreneurial intention and is partially mediated by career decision-making. Furthermore, self-efficacy moderates the mediating role of career decisionmaking between opportunity recognition and intention. This research facilitates a profound understanding of social entrepreneurial cognition and pre-entry decision-making. -
A Study on Regular Perfect Graphs
A graph (V, E) is said to be a perfect graph if the independence number of every induced subgraph in G is equal to the clique covering number of the subgraph in G. The independence number of a graph G is denoted by and#945;(G), and it is the maximum number of vertices in G such that no two of them belong to the same clique in G. The clique covering number of a graph G is denoted by and#952;(G), and is the minimum number of cliques required to cover the vertex set of G. F- perfect graph is a special type of perfect graph, where F can be any graph, like, complete graph (Km), the complement of a complete graph (Km), star, cycle, and so on. A graph G is said to be F-perfect if F-independence number for every newlineinduced subgraph H of G is equal to its F-covering number. The F-independence number of a graph G is the maximum number of vertices in G such that no two of them belong to the same F-subgraph in G. F-covering number is the minimum number of F-subgraphs in G that is required to cover the vertex set of G. newlineThe present study introduces the concept of regular perfect graphs, and induced regular perfect graphs which are denoted by R-perfect graphs, and R-perfect graphs respectively. These graph classes are obtained by considering F as the set of all regular subgraphs in a graph, R, and the set of all induced regular subgraphs, R, in a graph respectively. We conceptualise the graph parameters, R-independence number, and R-covering number for R-perfect graphs and R-independence number, and R-covering number for R-perfect graphs, and characterise both these classes of graphs. We initially study a subclass of regular perfect graphs, namely, cycle perfect graphs (C-perfect graphs) and induced cycle perfect graphs (C-perfect graphs). Further we extend the study to analyse various product graphs under C-perfection, and characterise them. -
A Study on Certain Topological Indices and Related Polynomials In Graphs
Topological indices are invariants of molecular graphs which are used for quantitative structure-property relationship (QSPR) or quantitative structure-activity newlinerelationship (QSAR) correlations. In this study, we have worked upon the bounds and exact expressions of certain specifc topological indices related with some graph newlineoperations. Further, we have determined the formulations of certain topological indices and co-indices for the total transformation graph. In addition, we have worked upon the reformulated forgotten index and obtained its exact expressions with respect to the transformation graphs and other graph product variants. We describe graph transformations, by means of which the reformulated forgotten index increases or decreases. Using these transformations, the trees, unicyclic and newlinebicyclic graphs extremal with respect to the index are characterized. We carried out newlinethe computation of equitable and non-equitable Zagreb and the relative equitable newlineand non-equitable Zagreb indices of certain chemical compounds like the polycyclic newlinearomatic hydrocarbons, the rhombus silicate, rhombus oxide and copper oxide networks using the equitable Zagreb polynomial formulations. As to demonstrate the application of our study, we have carried out the QSPR analysis of the anti-HIV and anti-Covid drugs with respect to the physico-chemical drug characteristics using the notion of Mand#8722;polynomial and topological indices, thus asserting that the indices taken under study are inherent units for the QSPR inspection of the drugs. -
Process of Emotion Regulation in Relation to Attachment and Mindfulness Traits During Gottman's Dreams-WIthin-Conflict Intervention
Gottman Couple Therapy (GCT) promotes process research to comprehend how interventions function. A GCT intervention called Dreams-within-Conflict (DWC) encourages healthy emotional regulation techniques including expression and experiencing to diffuse impasses. The purpose of this study is to examine emotion regulation and experiencing changes during a single DWC session using convergent mixed methods on N=30 individuals (15 couples). The techniques for controlling emotions (Extrinsic/Intrinsic affect Worsening/Improving strategies EW, IW, EI, II) and experiencing mode/peak scores (ESM & ESP) were measured using self- assessments, observation rating and coding of video recordings, interviews, and feedback reports in relation to individual traits of emotion regulation (cognitive reappraisal & suppression), beliefs, attachment (avoidance & anxiety), and mindfulness. Paired-samples t-test revealed that DWC significantly reduced partners' EW and boosted partners' EI and II. Both ESM and ESP significantly improved. Results from hierarchical linear modelling showed that before-DWC EI, gender, cognitive reappraisal, and suppression predicted EI and before-DWC II and avoidance predicted II. None of the variables predicted EW or IW. Gender predicted ESM. The emotional regulation strategies, experiencing and preferences for expression (over suppression) shared by Indian couples were examined using thematic analysis. Avoidance, conflict behaviours, and prioritising parents' emotions over partners' (in men) were most used strategies. Experiencing levels 1-3 used before-DWC changed to 3-4 during-DWC. Expression was unanimously preferred by Indian couples. -
Determinants and Impacts of Mergers and Acquisitions in the Drugs and Pharmaceutical Industry in India
Mergers and Acquisitions (MandAs) are inorganic growth strategies adopted by firms for achieving the objective of long-term growth maximization. Compared to other inorganic growth strategies like joint ventures and strategic alliances, MandAs offer deeper restructuring opportunities and better control over business over a long-term newlinebasis. During the third wave of globalization which started in early 1990s, MandAs became a popular strategy for firms to expand their businesses beyond the national boundaries. newlineIndian economy has been witnessing buzzling activity in the MandA landscape. A sectoral analysis of MandA trends identifies pharmaceutical sector as one of the top 5 newlinesectors with the highest MandA deal values during the period 2013-2016. Though Pharma sector has witnessed a decline in deal values during few years in the recent past, the resilience of the sector is visible through its ability to bounce back with record newlinebreaking deal values. Due to the continuous regulatory changes occurring in the domestic and foreign markets, pharma companies have to constantly change their strategies to survive and grow in the industry. MandAs enable pharma companies to adapt to these changes quickly. This study explores how the firms in the pharmaceutical sector use MandA as a strategy to navigate through the dynamic competitive landscape. The objectives of this research are threefold developing an understanding of the motives behind MandA decisions of the pharma firms, identification of the firm level determinants of acquisition probability and assessment of impact of MandAs. This study newlineuses qualitative content analysis for identification of MandA motives. The firm level newlinedeterminants of acquisition probability have been explored using Random Effect Logistic (REL) regression using panel data. Case study approach has been employed to assess the MandA impact by comparing the MandA motives with the post MandA outcomes. -
A Sociopolitical Study of Contemporary Ideological Discourse on Ethnic Nationalism From Tamil Nadu
The discourse on nation-building is primarily ideological and differs according to context. The present research intends to study the newlinecontemporary discourse on Ethnic nationalism produced within Tamil Nadu. It specifically focuses on the ideological discourse of Seeman and engages with the ideological discourse analysis model of Teun A van Dijk. The present research traces the emergence of Tamil nationalism in the Dravidian political terrain and the rise of Seeman s Tamil nationalism among various notions of Tamil nationalism. In this context, Dijk s ideological discourse analysis model contributes to finding the position that Seeman s Tamil nationalism occupies. Further, the research seeks to locate its position within the sociopolitical milieu of Tamil Nadu by critically analysing three cases: newlinethe pro-Jallikattu protest (2017), the Salem-Chennai Greenfield Highway protest (2018) and the Language Issue over the Consecration of Thanjavur Brihadeeswara Temple (2020), and the Assembly election results of 2016 newlineand 2021. These cases foster to explore how Seemanism is turning out to be an influential ideological discourse. Besides, the research intends to determine how far Seemanism fits within the theoretical framework of Anthony D. Smith s three processes of ethnonational transformation. The three processes are vernacular mobilisation, cultural politicisation of vernacular heritage and ethnic purification. Vernacular mobilisation works to protect the ethnic sources such as indigenous traditions, customs, language, symbols and memories. This process has underpinned to figure out how the ideological discourse is striving to disseminate the knowledge of ethnic symbols such as Murugan, Jallikattu, and Parai. Further, it has newlineassisted to find that the ideological discourse is rediscovering the position of Tamil by claiming it is an ancient language. -
Study of Rayleigh-Benard Dynamical System Involving Newtonian and Nanofluids in Rectangular and Cylindrical Enclosures
Analyzing and#64258;uid and#64258;ow behavior in the presence of temperature gradients subjected to internal and external forces in diand#64256;erent geometries is essential for optimization newlineprocesses for various engineering applications, guiding the design of more efcient thermal systems. This thesis focuses on investigating the Rayleigh-Bard convection problems occupying rectangular and cylindrical enclosures. The linear and newlineweakly nonlinear analyses are carried out that reveal the results on regular convection, heat transport and chaotic motion for each of the problems. Steady and newlineunsteady states of the Rayleigh-Bard system are studied using the Lorenz model. The dynamical system is investigated to look for possible chaotic motion. Fluid systems can exhibit chaotic behavior, and understanding the chaotic nature of these and#64258;ows is essential for accurate predictions of their evolution over time. In view of this, the regular, chaotic, and periodic natures of the dynamical system is thoroughly analyzed. Further, the inand#64258;uence of various parameters on the indicators of chaos is explored. Additionally, the thermal performance of the system is looked into by introducing nanoparticles/nanotubes into the base and#64258;uid. newlineWith the aformentioned motivation, we now present the abstract of each of the problems considered in this thesis one-by-one. 1. Impact of boundary conditions on Rayleigh-Bard convection: stability, heat transfer and chaos In the frst problem of the thesis, discussed in Chapter 3, a comparison is made newlinebetween the results of Rayleigh-Bard convection problem for diand#64256;erent boundary combinations, namely, rigid-rigid-isothermal, rigid-free-isothermal and free-free isothermal boundaries for a Newtonian and#64258;uid. The linear and weakly-nonlinear analyses reveal that the onset of regular and chaotic motions in the case of rigid-freeisothermal boundaries happens later than that of free-free isothermal boundaries but earlier than rigid-rigid-isothermal boundaries.+ -
Design and Development of Adaptive Authentication Model to Detect User Behavior Anomalies
The password-based authentication system has recently become more secure as the riskbased authentication system(RBA) is indentured. Recent research in the area has shown the significant use of 2 Factor Authentication (2FA) and Multi-Factor Authentication(MFA) in many commercial applications using Risk Based newlineAuthentication(RBA). The RBA system monitors the parameters extracted during the user login process, and based on the proposed model, the system raises a multi-factor newlineauthentication to the user. As the vulnerability has increased concerning passwords, fingerprints easy access to any web application may result in a security flow; the reason can be the existing methodology of the RBA system and also the unavailability of the data of the users during the initial login process, which hinders the authentication system during the initial login process as there is no standard method to incorporate RBA in the authentication system. Few researchers have proposed novel approaches to improve the authentication system. Still, to the best of our knowledge, no research has suggested methods to address the authentication system during the initial login process and also provide a robust way, a combination of Machine Learning (ML) and statistical newlineapproaches. Hence, a novel method is proposed for the RBA system during the initial newlinelogin phase using a Hierarchical Sub-Feature Based Model -(HSFBM) for different user newlinecategories. The FAR is comparatively better in our proposed model against the standard newlinemodel, with minimal re-authentication requests for the user. -
Impact of Integrated Explicit Instruction on Development of Critical Thinking Skills and Dispositions among Adolescents
Critical thinking is an essential skill that is required for survival in the twenty first newlinecentury. Educational institutions are gearing up to align their curriculum to ensure the development of critical thinking skills and dispositions among their candidates. However, there are few empirical studies that layout a clear road map of instructional strategies for the teaching of critical thinking. Given that adolescents are the most receptive to neurobiological skill and disposition development and that Literature is one of the best platforms that connects to real life, this research uses the educational design research method to develop an Integrated Explicit Instruction (IEI) module that could be used in English classes to teach adolescents critical thinking skills and develop in them critical thinking dispositions. This research not only bridges the gap in an empirically tested instructional strategy to teach critical thinking but also lays the foundation for further longitudinal studies that could measure the development of critical thinking skills and dispositions long term in participants who have been exposed to the intervention. -
A Study on Dominating Functions in Signed Graphs
In this thesis, a study on Roman dominating functions in the realm of signed graphs is carried out. Unlike graphs, not all signed graphs admit a Roman dominating function, which leads to the primary problem of exploring signed graphs admitting a Roman dominating function. Further, variants of dominating function such as Roman {2}-dominating function, Minus dominating function and Signed dominating function in signed graphs are also studied. A dominating set of a signed graph S is dened as a set D and#8838; V such that each vertex v and#8712; V \ D has at least one neighbour u and#8712; D with and#963;(uv) = 1. The domination number and#947;(S) is the minimum cardinality among all the dominating sets newlineof S. A characterisation for minimal dominating sets of a signed graph along with newlinecharacterisations of signed graphs with domination number k, where 1 and#8804; k and#8804; 4 and newlinen and#8722; 2 and#8804; k and#8804; n are obtained. A Roman dominating function(RDF) on a signed graph S = (G, and#963;) is a function f : V (S) and#8594; {0, 1, 2} having the properties that (i) for every vertex u and#8712; V (G), f(N[u]) = f(u) + Pvand#8712;N (u) and#963;(uv)f(v) and#8805; 1 and (ii) for each vertex u and#8712; V (G) with f(u) = 0, there exists a vertex v and#8712; N +(u) having f(v) = 2. The signed graphs newlineadmitting an RDF are explored and certain classes of signed graphs such as paths, newlinecycles, stars admitting an RDF are characterised. Further, structural properties of signed graphs with 3-regular underlying graphs that admit an RDF are presented newlineand a characterisation of net-regular signed graphs with 3-regular underlying graphs, newlineadmitting an RDF is obtained. The signed graphs with Roman domination number equal to 2, 3, 4 and n are characterised. Further, criticality concepts have been examined by studying and#947;R-edge critical signed graphs S for which and#947;R(S +e) lt and#947;R(S), where the signature of the edge e is 1. A characterisation of and#947;R-edge critical signed trees with a single negative edge is presented, apart from some general results on and#947;R-edge critical signed graphs. -
Performance Investigation of the High Strength Concrete Using Natural Zeolite with Industrial Waste Materials
Concrete is used in the construction of various structural elements. High Strength newlineConcrete (HSC) production for huge infrastructure projects is challenging. The newlinemanufacture of cement significantly causes global carbon dioxide (CO2) emissions. newlineModifications have been made to cement concrete problems to minimize CO2 emissions and Ordinary Portland Cement (OPC) consumption. This research focuses on developing HSC blended with Natural Zeolite (NZ) and industrial by-products like newlineSilica Fume (SF), Fly Ash (FA), and Metakaolin (MK) to enhance concrete quality, newlinesustainability, and performance. Partial replacement of OPC with 5% NZ and industrial waste materials in 5%, 10%, and 15% amounts to produce M60 grade HSC mixes. In the laboratory, 1,200 concrete specimens were tested for mechanical properties for 3, 7, 28, 60, and 90 days, as well as durability tests such as the Rapid Chloride Penetration Test (RCPT) for 28 days and the acid attack test for 60 days. Mix M3 (85% OPC + 5% NZ + 10% MK) exhibited the highest compressive strength at 72 MPa, split tensile strength at 5.3 MPa, and flexural strength at 9.4 MPa for 90 days curing period, attributed to its low porosity. The reactive silica (SiO2) and alumina (Al2O3) in the mix transformed calcium hydroxide (Ca(OH)2) into calcium silicate hydrate (C-S-H) gel and aluminate compounds. This process improved the newlinemicrostructure of the hardened concrete, resulting in increased imperviousness. The newlinestudy also includes the effect of these industrial waste materials on Zeolite concrete by microstructure analysis. The mathematical models were developed using SPSS software to predict the durability and mechanical properties of all the concrete mixes based on the laboratory data, considering parameters like mix proportions and curing days. -
Investigation on Mechanical and Durability Properties of Geopolymer Concrete with Ground Granulated Blast Furnace Slag Incorporating Sugarcane Bagasse Ash
This study deals with strength, durability, elevated temperature behaviour, cost, energy and carbon efficiency of sustainable GPC developed with GGBS and SCBA. Sodium hydroxide (NaOH) of 8M, 10M, and 12M and sodium silicate (Na2SiO3) were used as alkaline activators with sodium silicate to sodium hydroxide ratio being 2.5. Fifteen different binary blend GPC mixtures were prepared by varying SCBA content (0%, 5%, 10%, 15% and 20% by mass of precursor) and also by varying molarity of NaOH by 8M, 10M and 12M. The developed GPC's fresh, hardened, microstructural, and correlation characteristics have all been assessed. Various tests such as the slump cone test, Cs, Sts, Fs, and UPV test were conducted. SEM, Edax, and XRD analysis were examined for understanding the microstructural characteristics. For a target strength of 40 MPa, the GPC produced with 20% SCBA and 80% GGBS with an 8M NaOH solution and an SS/SH ratio of 2.5 can be utilized. The reason for the development of higher strength in higher molarity of GGBS-SCBA based GPC specimens is clearly shown by SEM micrographs, which indicate a dense and packed matrix. The presence of CASH gel confirmed this in the GP matrix. Durability studies such as rapid chloride permeability, sorptivity and early and long-term effect of sulphate attack were conducted on GGBS-SCBA based GPC. Also elevated temperature behaviour of GPC specimen subjected to different temperatures of 200?C, 400?C, 600?C and 800?C were studied to evaluate the strength, mass loss and effect on microstructures due to elevated temperature. The degradation of geopolymer concrete at different elevated temperatures was observed by SEM, Edax, XRD and FTIR. From the test findings it is noticed that the GPC developed have good durability characteristics. It is also noticed that geopolymer concrete retains more than 50% of strength up to a temperature of 600 ?C. From scanning electron microscope analysis of GPC developed with GGBS and SCBA, it is found that there are larger crack formations and pores which are visible in the geopolymer concrete matrix when the specimens are exposed to an elevated temperature of 800?C which confirms the degradation of C-A-S-H gel in the GPC mixtures developed. Additionally, incorporation of sugarcane bagasse ash in GPC will reduce disposal problems and also carbon dioxide emission.