Browse Items (16481 total)
Sort by:
-
A Slotted Circular Patch Antenna with Defected Ground for Sub 6 GHz 5G Communications
In this paper, a slotted circular patch antenna with Defected Ground Structure (DGS) is presented. The slots created on radiating element and the defect introduced on the ground plane shifted the resonance frequency from 2.49 GHz to 1.17 GHz. This corresponds to 53% reduction in size at 1.17 GHz. The proposed antenna is designed on FR-4 substrate (r=4.4) with thickness of 1.6 mm. Simulations are carried out using HFSS Ver. 18.2. The simulated reflection coefficient of Circular Patch Antenna (CPA) at 2.49 GHz, Slotted Circular Patch antenna (SCPA) at 2.34 GHz and Slotted Circular Patch antenna with Defected Ground Structure (SCPA-DGS) at 1.17 GHz are - 28.7 dB, -31.33 dB and -11.03 dB respectively. For validating the simulated design, SCPA-DGS is fabricated and measured its reflection coefficient and VSWR using Vector Network Analyzer (Anritrsu S820E). The measured and simulated values are very well matched with each other. Therefore the proposed antennas may be used in sub 6 GHz 5G communication applications. 2022 IEEE. -
A skip list based remodelled system for LRU based page replacement algorithms and its virtual layer /
Patent Number: 202141012144, Applicant: Hitha Paulson.
The locality of reference property exhibited by the referenced pages in virtual memory environment led to page replacement algorithms based on page reference recency. Among the various algorithms proposed and implemented, the Least Recently Used (LRU) based page replacement algorithms in the virtual memory environment led to hopeful research outcomes. The improvised versions of LRU algorithms are still dominating the prominent operating systems like Windows, Linux and Flash memory based operating systems of mobile environment. -
A site-isolated Lewis acidic aluminium and Brsted basic amine sites in the dimeric silsesquioxane cage as a reusable homogeneous bifunctional catalyst for one-pot tandem deacetalization/deketalization-Knoevenagel condensation reactions
The development of multifunctional catalysts for one-pot tandem reactions is significantly required to attain multiple sequential transformations in a single reactor, which would considerably decrease the number of manipulations demanded for chemical manufacturing in industries. Herein, dimeric silsesquioxane Al-POSS-NH2 (2), a homogenous bifunctional acid-base catalyst containing environmentally friendly robust silica and high chemical and thermal stabilities, permanent catalytic activity, and reusability, was synthesized by the reaction of trisilanol aminopropyl hexaisobutyl-POSS (1) with trimethylaluminium. Al-POSS-NH2 was successfully used as a bifunctional catalyst for one-pot tandem reactions because of the synergism and effective compartmentalization between Lewis acidic aluminium and Brsted basic amine sites (>10.0 in the dimeric silsesquioxane cage, which was confirmed by DFT and QTAIM studies. Subsequently, different acetals were tested to obtain their corresponding benzylidene malononitrile derivatives using Al-POSS-NH2 for the one-pot tandem deacetalization-Knoevenagel condensation reactions and showed high efficiency (>90%) under optimized conditions (DMF, 0.3 mol% catalyst loading and 80 C) with different reaction times. Furthermore, the bifunctional Al-POSS-NH2 catalyst was separated from the reaction mixture via the precipitation method by adding acetonitrile into the reaction mixture and reusing it for five consecutive cycles without losing activity considerably, thus providing the inherent advantage over traditional homogeneous catalysts. In a one-pot tandem deketalization-Knoevenagel condensation reaction for various ketals, the reaction condition was slightly modified by increasing the catalyst loading (0.6 mol%) and reaction time (16 to 24 hours) to acquire better conversion and yield of their desired products. Finally, the present study suggests that the bifunctional POSS might facilitate the rapid development of environmentally friendly and economically feasible catalysts for multistep reactions. 2023 The Royal Society of Chemistry. -
A Single Sign on based secure remote user authentication scheme for Multi-Server Environments
A Multi-Server Architecture comprises of a server environment having many different servers which provides the user the flexibility of accessing resources from multiple Service Providing Servers using the same credential. The primary objective of a Multi Server Environment (MSE) is to provide services of different Service Providers (SPs) without repeating registration at each SP server, and to get a unique single credential for all the servers in MSE. However, the conventional MSEs, proposed by various researchers, proposes the individual authentication service by each SP on their respective server using the credential issued by the Registration Authority of MSE. The mechanism requires the user to access each SP by keying the same credentials for every SP separately. Single Sign On (SSO) is an authentication mechanism that enables a user to sign-on once and access the services of various SPs in the same session. SAML is generally used as a Single Sign-On protocol. This work analyzes the smart card based authentication scheme for Multi-Server Environment proposed by Li et al.'s and discuss various security attacks on the said scheme. The paper also proposes a Secure Dynamic-ID based scheme using smart cards or crypto cards which do not require a verifier table and implements Single Sign On feature using SAML protocol, thus allowing the user to enjoy all the features of an MSE along with SSO. 2014 IEEE. -
A simulation model to estimate the amount of waste collected in a common bin after compulsory segregation /
Mathematics Applied In Science And Technology, Vol.7, Issue 1, pp.314-318, ISSN No: 0973-6344. -
A simple software for swift computation of photon and charged particle interaction parameters: PAGEX
PAGEX is a compact and user-friendly cross-platform software developed for swift computation of photon (X-ray and ?-ray) and charged particle interaction parameters for various applications. It is designed based on well-established theoretical formulations and computational techniques integrating various Python packages to effectively calculate parameters such as partial/total photon interaction cross-sections and mass attenuation coefficients, charged particle mass stopping powers and cross-sections, effective atomic number and electron density, mass-energy absorption coefficient, KERMA and build-up factors over a wide energy range. This tool is capable of generating both tabular and graphical outputs which can be saved in any user desired format. PAGEX has been verified against other widely employed software and databases, demonstrating good agreement. This software which facilitates robust computation is freely available from the authors. 2021 Elsevier Ltd -
A simple and efficient synthesis of imidazoquinoxalines and spiroquinoxalinones via pictect-spengler reaction using Wang resin
An efficient approach for the synthesis of various imidazoquinoxalines and spiroquinoxalinones has been reported from 2-(1H-imidazol-1-yl) aniline and different aldehydes using Wang-OSO3H as a reusable catalyst to get in good yields. The reaction condition has been optimized by screening in various solvents and a gram scale experiment has also demonstrated. Further, the substrate scope of the reaction has also been well demonstrated. 2021 Taylor & Francis Group, LLC. -
A Simple and Efficient Ligand-Free Copper-Catalyzed C-N Bond Formation of Aryl (Hetero) Halides and N-Heteroaryl Amines
In this protocol, we report a simple, inexpensive, and user-friendly conventional method for C-N cross coupling between aryl/heteroaryl halides and hetero aryl amines using copper iodide as a catalyst in DMSO as a solvent to prepare pyrimidines and pyrazines derivatives. The reaction conditions were optimized by screening in various copper catalysts and bases. The substrate scope of the reaction was also carried out to prepare novel functionalized N-arylated compounds in good yields. 2021 Taylor & Francis Group, LLC. -
A Simple and Efficient [(n-Bu3Sn)2MO4]n Catalyzed Synthesis of Quinazolinones and Dihydroquinazolinones
A novel unprecedented approach for the synthesis of various quinazolinones and dihydroquinazolinones has been using [(n-Bu3Sn)2MO4]n as a catalyst. The reaction has been screened in various solvents and a gram scale experiment has also been demonstrated under given conditions. Further, the substrate scope of the reaction and the recyclability of the catalyst have also been studied. 2021 Taylor & Francis Group, LLC. -
A SIGNIFICANT STUDY ON ROBUST MEASURE OF LOCATION PARAMETERS USING DATA DEPTH APPROACHES
Data depth procedures are statistical methods used to measure the centrality or depth of a point within a multivariate dataset. These procedures provide a way to quantify how deep or outlying a point is relative to the overall distribution of the data. This study explores various data depth procedures to find reliable location estimations in cases like with and without outliers. In this paper, various depth procedures, such as Mahalanobis depth, Halfspace depth, Euclidean depth, Simplicial depth, and Projection depth, are studied and compared. The efficiency of these depth functions is evaluated using real datasets and simulation studies with R software. 2025, Gnedenko Forum. All rights reserved. -
A Signature-Based Mutual Authentication Protocol for Remote Health Monitoring
Remote health monitoring can offer a lot of advantage to all the players in healthcare industry and it can contribute to reduced healthcare expenses. Wireless medical sensor networks capable of accumulating and transferring vital parameters of patients play a crucial role in remote health monitoring. Security and privacy are major concerns preventing the patients from adopting this technology with an open mind. This paper presents a signature-based authentication protocol for remote health monitoring. The work also discusses an authentication protocol for the mutual authentication of users and medical server. The protocol does not require the server to maintain a password table. The proposed algorithms are resistant to various attacks such as replay attack, stolen verifier attack, and privileged insider attack. The work includes the informal and formal security analysis of the proposed protocols. Scyther tool is used for formal security analysis and the results show that the protocol is resistant to various common and automated attacks. 2019, Springer Nature Singapore Pte Ltd. -
A Shortest Path Problem for Drug Delivery Using Domination and Eccentricity
The concept of domination was first introduced in by Ore in 1962. With this, the study of domination gained importance and has been vigorously studied since then. The idea about eccentricity for vertices in a graph was given by Buckley and Harary in 1990. This paper combined the ideas about domination and eccentricity and provides the observation obtained during the study. Most of the basic ideas about domination and eccentricity has been covered and also a comparative study between these two has been stated along with problem of drug transportation through networks. These ideas can be further used to solve the real-world problems which uses concepts of domination and eccentricity like for example drug delivery game theory problems, routing problem, assignment problem and many more. 2023, The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd. -
A Short Review on Recent Applications of Chitosan Biopolymer in Gene and Drug Delivery
The battle of the human race with genetic disorders was prevailing from the time immemorial. Revolutions and modernizations in science and technology have clearly improved our understanding regarding the molecular basis of genetic disorders thereby aiding in designing new therapeutic interventions in their treatment and prevention. With the advent and development of gene therapy in the last few decades, promising windows were opened for treatment and prevention of genetic disorders and cancer. Despite of its remarkable significance in medicine, the common practice of using viral vectors as gene delivery agents has created controversies and concerns among the scientific community. This made the research focus on biobased polymers as alternative non-viral vector systems for gene and drug delivery for treating genetic disorders and cancer. Chitosan is a cationic polymer that can be easily tailored to serve as gene and drug delivery due to their biocompatibility and biodegradability. Their structural integrity and stability have made them widely used for various applications in the biomedical field. Chitosan and its derivatives have gained more attention as vectors for gene delivery and cancer therapy in the past decade. The amenability of structural modification, non-toxicity and high biodegradability of chitosan derivatives can make them prospective carriers for controlled drug delivery in future. 2022 Chemical Publishing Co.. All rights reserved. -
A short review on environmental impacts and application of iron ore tailings in development of sustainable eco-friendly bricks
Increased mining activity of iron ore has led to the generation of voluminous wastes of various nature, especially during the different stages of its extraction and production. The improper disposal of such waste causes negative impact on the environment. One such waste which is generated during the beneficiation process of iron ore is waste iron ore tailings, which is also termed as IOT. Further, dumping of IOT on open ground creates huge dumping sites. This dumping sites have been a concern to the environment and human population in its close vicinity. Therefore, a need to effectively use IOT has become one of the subjects of interest for many researchers. This article provides a short review of environmental problems caused due to improper disposal of IOT, and also reviews on the reuse methods of IOT in the construction sector, which helps to alleviate the environmental pollution associated with improper disposal of IOT. Furthermore, reuse of IOT in construction sector reduces the exploitation of the virgin materials for production of construction material, and thus reducing depletion of natural resources. Based on the existing literatures and findings it was observed that the use of IOT to develop stable building blocks using unconventional methods showed great potential and improved performance, when compared with conventional materials such as clay fired bricks. 2021 -
A shap-enhanced PCA-DBSCAN framework for interpretable retail customer segmentation and strategic insight
The rapid expansion of online retail underscores the critical need for precise customer segmentation to drive personalized marketing, reduce churn, and boost lifetime value. This study develops an end-to-end, highly interpretable segmentation pipeline encompassing advanced feature engineering, dimensionality reduction, exhaustive hyperparameter tuning, and robust validation to reveal stable, actionable customer groups in a large, real-world UK online-retail dataset (541,909 records). We augment the classic RFM (Recency, Frequency, Monetary) framework with: TPAC TF-IDF embeddings of item descriptions, holiday-purchase flags, and exponential recency decay; CACV net monetary value and cancellation ratios. After outlier filtering on RFM scores, we apply PCA (230 dimensions) and compare ten clustering methods (selected to represent major algorithmic paradigms: centroid-based [K-Means], probabilistic [GMM], hierarchical [BIRCH, Agglomerative], density-based [DBSCAN, OPTICS, HDBSCAN], graph-based [Spectral], message-passing [Affinity Propagation], and mode-seeking [Mean Shift]). We perform a full grid search per algorithm using a 'safe' silhouette scorer (ignoring noise) and also report Davies-Bouldin and Calinski-Harabasz indices. Temporal stability is assessed via adjusted Rand indices across time splits, and cluster interpretability is enhanced through SHAP-based feature importance analyses. By integrating textual, temporal, and cancellation behaviors into segmentation followed by systematic tuning and multi-metric validation our pipeline delivers superior cluster quality and actionable business insights compared to prior work. Segments directly enable strategic interventions: 'High-Decay Loyalists' (precision = 0.92) receive VIP retention offers yielding 2231% ROI lift, while 'At-Risk Cancellers' (recall = 0.89) trigger targeted win-back campaigns. We also demonstrate a reproducible framework for selecting both model and feature set. DBSCAN (? = 0.3, min_samples = 3 on 10 PCA components) achieved the best silhouette score (0.986), markedly exceeding the 0.72 benchmark in the literature. Agglomerative clustering (average linkage, 2 clusters) scored 0.776, while OPTICS and Spectral Clustering also outperformed classical Gaussian- or centroid-based models. A temporal ARI above 0.8 confirms cluster stability. The Author(s) under exclusive licence to The Society for Reliability Engineering, Quality and Operations Management (SREQOM), India and The Division of Operation and Maintenance, Lulea University of Technology, Sweden 2025. -
A Sentence-Level Risk Estimator for Identifying Hallucinations in Generative AI
Hallucination, defined as the generation of factually incorrect or ungrounded content, represents a critical challenge in large language models and summarization systems. Existing evaluation metrics often operate at the document level and fail to pinpoint erroneous sentences with sufficient granularity. This work introduces Sentence-Level Risk Estimation (SRE), a unified framework for detecting hallucinations at fine granularity by integrating three complementary signals: semantic alignment using BERT-based embedding similarity, QA-based factuality verification through question-answer pair generation and validation, and Natural Language Inference (NLI) entailment assessment using pre-trained models such as DeBERTa-MNLI. These signals are aggregated into a unified Sentence Risk Score (SRS) via weighted calibration. Experimental evaluation on CNN/DailyMail and XSum datasets demonstrates that the proposed method achieves precision of 0.85, recall of 0.75, F1-score of 0.80, and correlation with human judgments of 0.85, representing substantial improvements over existing approaches including FactCC, QAGS, and SummaC. The proposed framework enables AI systems to flag risky sentences for review or regeneration, thereby improving trust and safety in generative applications. 2026 IEEE. -
A Semiotic Analysis of Political Cartoons in Malayalam Newspapers during the 2016 Assembly Election
I am immensely grateful for the everlasting love and grace of the Almighty God for granting me wisdom and guiding me to complete this study successfully. I would like to thank Dr (Fr) Abraham V M, Vice- Chancellor, Christ University, Bengaluru for giving me the opportunity to pursue research and facilitating me to complete my study. I thank Mr. Padmakumar, Head of the Department of Media Studies for being always approachable, understanding and infusing positivity that motivated me to persist in my endeavours with conviction that has enabled me to complete my thesis. I express my sincere thanks to my guide and supervisor Dr. Pradeep Thomas J.A Department of Media studies, Christ University, Bengaluru for his constant supervision, mentoring and valuable inputs throughout the course of my study. I thank the department of Media Studies for taking time out and guiding my thesis at every stage. I have been able to build my thesis with all your valuable insights. I sincerely thank all my M.Phil. professors for their constant help and guidance. I express my heartfelt gratitude to Mr. Sukumaran Potti (Chairman, Kerala Cartoon Academy), Mr. Baiju Paulose (Staff Cartoonist, Malayala Manorama), Unnikrishnan K (Chief Sub Editor, Mathrubhumi), V R Rajesh (cartoonist, Madhyamam), T.K Sujith (staff cartoonist, Keralakaumudi) and Satish Acharya, renowned Indian cartoonist for taking part in the study and giving valuable contribution for the study. Finally, I am thankful to my parents, brother and my friends for their constant encouragement, moral support, continuous inspiration and prayers to carry out this dissertation successfully. -
A Self-Reflective and Empathy Based Environmental Education Intervention to Enhance Environmental Values and Knowledge of Preadolescents
Environmental degradation and climate change have become common phenomena and they are attributable to human actions focusing solely on economic growth. Therefore, it is necessary to fetch drastic changes in the lifestyles of majority of the public and to acquire the collective capacity of ecological intelligence. The accumulation of ecological intelligence results in environmental knowledge, values, and skills to deal effectively with the environment. The present study is an attempt to develop and apply a self-reflection and empathy-based Environmental Education module for 11-12 years old children to enhance their environmental values and knowledge. The study utilized a pre-test post-test quasi experimental design for which two existing sixth grade classes (intervention group and control group) from different schools, selected through purposive sampling formed the sample. A pre-test and a post-test were conducted on the participants environmental values, attitude, knowledge for the intervention and control groups. Additionally, environmental behaviour, self-reflection and insight were assessed before and after the intervention and the student workbooks were undergone content analysis for the intervention group. The self- reflective and empathy-based Environmental Education intervention was administered for the class selected as the intervention group in between the pre and post-tests. The researcher observed the interventions effectiveness on environmental values with the help of the attitude scale of the Children's Environmental Attitude and Knowledge Scale (CHEAKS), through the content analysis of student workbooks, and through session feedback form. The positive impact of the intervention on environmental knowledge was understood from the analysis of the knowledge scale of the Children's Environmental Attitude and Knowledge Scale (CHEAKS) and from the session feedback form. Additionally, there is an improvement in the intervention groups reflective thinking ability and environmental behaviour when assessed through Self-Reflection and Insight Scale for Youth and parent observation checklist. The study has implications concerning the implementation of Environmental Education. -
A self-powered and stretchable magnetic film for humanmachine interface applications
Developing stretchable, self-powered electronic interfaces for ambient energy harvesting is crucial for next-generation wearable electronics and humanmachine interface applications. We present a stretchable magnetoelectric composite film comprising Ni0.5Co0.5Fe2O4magnetic nanoparticles embedded in an Ecoflex matrix. The nanoparticles, synthesized via co-precipitation, exhibit a strong magnetic response, while Ecoflex ensures high stretchability and skin-mountable adaptability. The comprehensive structural, morphological, and magnetic analyses confirm the formation of a uniform and multifunctional film. The optimized device delivers a peak output voltage of ?8.3 V and a power density of 3.16 mW cm?3under ambient magnetic fields, outperforming conventional soft nanogenerators. The films demonstrate excellent durability under repeated deformation and maintain stable performance at tensile strains up to ?315%. Integration into a soft wearable platform enables real-time gesture recognition, with distinct voltage signals for finger bends and gestures under low-intensity magnetic fields. This work highlights the potential of magnetic/Ecoflex-based nanogenerators in self-powered, wearable, stretchable electronics, smart prosthetics, and intelligent humanmachine interfaces. This journal is The Royal Society of Chemistry, 2025 -
A self-cooperative trust scheme against black hole attacks in vehicular ad hoc networks
The main objective of the Vehicular Adhoc NETwork (VANET) is to provide secure communications for the vehicles in the network without fixed infrastructures. It inherits all the properties of the MANET. Achieving reliable routing to avoid various routing attacks is the major concern in the vehicular network. Routing attacks degrade the performance of the network. Black hole attack is one of the routing attacks, which drops the data packets without forwarding them to the destination vehicle. Different routing schemes are proposed to provide security against these attacks, which still have security issues. Hence a new self-cooperative trust scheme is proposed in this paper, to detect single as well as collaborative black hole attackers in the network. Two processes: self-detection and cooperative detection, are used to detect attackers in the network. Results show that the proposed scheme has better performance in terms of throughput, PDR and delay. Copyright 2021 Inderscience Enterprises Ltd.