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(R2165) Two Different Stages With Two Distinct Harvesting Processes
No full textThis study extends the classical Lotka-Volterra prey-predator model by incorporating a stage structured prey population consisting of juvenile and adult stages, while considering a single predator species governed by a Holling type II functional response. The growth of the juvenile prey depends on the adult prey population and since the juvenile prey has no reproduction capability. Two distinct harvesting strategies are introduced in the model. Constant-yield harvesting is applied to the juvenile stage of the prey population and represents a fixed amount of harvest regardless of population size. Constant effort harvesting is applied to the adult stage of the prey population and the harvest rate is determined by the level of harvesting effort and the prey abundance. The boundedness and stability of the system are analyzed and the dynamics of the model are further illustrated through the figure. The results highlight the influence of stage-specific harvesting on the overall prey-predator dynamics
Hotline Press Newspaper- February 1991 Vol 7 No 28
No full texthttps://digitalcommons.pvamu.edu/hotline-press-newspaper-hempstead1991/1013/thumbnail.jp
Integrating Semi-Supervised Learning And Ensemble Deep Learning For Low-Resource Deep Knowledge Tracing
No full textAs learning platforms scale, two obstacles prevent Deep Knowledge Tracing (DKT) from thriving in practice: the scarcity of labeled interactions and the opacity of predictions. We introduced a semi-supervised, ensemble DKT pipeline that trains diverse architectures, including Knowledge Proficiency Tracing (KPT), Exercise-Correlated KPT (EKPT), and Dynamic Key-Value Memory Networks (DKVMN) on a mixture of limited labeled and abundant unlabeled learner interactions, then aggregates predictions via majority voting to stabilize learning and reduce variance. Evaluated on benchmark datasets such as ASSISTments, the combined approach yields consistent gains in AUC, accuracy, and precision over strong supervised baselines while revealing influential interactions, surfacing spurious correlations and temporal leakage risks, and guiding targeted interventions. This contribution provides data-efficient pipelines that enhance predictive performance, foster educator trust, and support personalized learning at scale.
Index Terms — Education data mining, knowledge tracing, machine learning, MOOC
Hydrolysis Of Cellulose And Cellulose Model D-Cellobiose Using Amino-Sulfonic Acid Hydrochlorides As Catalysts
No full textThe accelerated industrialization has boosted the demand for fossil fuels, increasing prices and greenhouse gas emissions, which has led to a quest for cleaner energy sources such as biofuels. Cellulose, a common biopolymer, is promising for renewable energy but is not hydrolysis-resistant. In this research, firstly, nine amino-sulfonic acids, orthanilic, aminomethanesulfonic, pyridine-3-sulfonic, 2-aminoethanesulfonic, 3-amino-1-propanesulfonic, and 3-morpholinopropanesulfonic acids, sulfanilic, and metanilic were investigated as model catalysts for cellulose hydrolysis. D-cellobiose, a more simplified model of cellulose, was similarly hydrolyzed using metanilic and sulfanilic acids and benchmarked against sulfuric acid. At 85 - 115°C, sulfanilic acid produced 76% glucose yield compared to 59% for sulfuric acid after 1.5 hours of reaction, and it proved better. The results confirm amino-sulfonic acids as efficient, green alternatives for the conventional mineral acids in biomass conversion.
Keywords: D-cellobiose, hydrolysis, amino-sulfonic acids, sulfanilic acid, metanilic acid, sulfuric acid, glucose yield, conversion of biomas
(SI15-113) Augmenting Cryptographic Security Through Inventive Application of the Kharrat-Toma Transform Algorithm
No full textThis paper introduces a cryptographic technique combining the Kharrat-Toma Transform and congruence modulo operators to improve the security of message encryption. The proposed model uses the mathematical properties of the Kharrat-Toma Transform and its inverse for direct scrambling and unscrambling processes while embedding sufficient complexity to resist modern cryptanalytic attacks. The model is subjected to experimental tests, including encryption quality analysis, Shannon entropy, and NIST randomness tests, in order to prove the strength of the model. Through encryption quality analysis, symbol frequencies in the ciphertext are masked heavily from having much correlation between plaintext and ciphertext. Entropy values indicate near-theoretical maximum for ciphertext, showing unpredictability and robustness toward statistical attacks. In addition, the model passes all NIST randomness tests, such as frequency, block frequency, and approximate entropy, hence proving quite effective. The approach conceals information better than standard cryptography approaches while resisting frequency and structure analysis-based attacks. This new method strikes a good balance between computation and security, providing safeguards for critical data in modern digital systems while providing greater resilience against emerging cryptographic attacks
(SI14-02) Analysis of Cross Diffusion Effects on MHD Nanofluid Past an Oscillating Plate with Ramped Wall Temperature
Full text linkThe primary objective of this research is to analyze the influence of cross-diffusion on the behavior of nanofluid flow, which is governed by unsteady hydrodynamics in the existence of a magnetic field. Additionally, this study considers the effects of thermal radiation and heat production. The flow occurs within a porous medium, passing through a vertically oscillating plate. The investigation focuses on two distinct nanofluid formulations, namely silver and titanium dioxide. The concept of similarity transformation is applied to simplify the governing system from partial differential equations (PDEs) to ordinary differential equations (ODEs). To obtain precise expressions for the concentration, temperature, and velocity profiles, Laplace transformation (LT) is utilized. The outcomes of this approximation are presented through graphs generated using MATLAB software. The analysis of these graphs reveals that the existence of external magnetic fields decelerates the momentum of the flow, although this effect is counteracted by the influence of thermal radiation and the heat production parameter
(SI14-06) Influence of Hall Effects on Rotating MHD Casson Fluid Flow over a Vertical Plate
Full text linkStudies of Hall effects regarding motion of fluid due to some external forces in MHD transport of reacting Casson fluid with heat generation over an impulsively emerging vertical plate are considered in this work. This theory proposes that because of a sudden rise in temperature and an accompanying surface concentration profile, which shows an elevation with time, the boundary plate has endured rapid expansion. In a rotational environment, this characteristic occurs homogeneously inside a porous uniform material. It applies the Laplace transform method for determining the fundamental equations subject to imposed starting and side conditions. Under isothermal conditions, accurate formulae are derived for temperature and concentration profiles. Numerical results are obtained using MATLAB software and graphically presented to enhance comprehension of different impacts of the ecological conditions. The study reveals that a fluid’s primary and secondary motion rate increase as the Hall current parameter grows; on the contrary, both of them decrease with the progressing value of a magnetism. This research reveals that a fluid’s primary velocity diminishes; on the other hand, a secondary velocity increases first, then decreases as the ascending values of Casson fluid parameter. Also, one can observe that a primary velocity falls, however, a secondary velocity rises as the permeability of a porous medium grows
The Dilemma Of The Black Airbnb Host: To “Whitewash” Or Not?
Full text linkThis research investigated the effectiveness of Black Airbnb operators who whitewash their Airbnb listings for the purpose of building trust and ultimately increasing booking intention. In the housing industry, whitewashing is a practice of non-White homeowners removing their images from their homes to increase valuation. Prior studies on whitewashing focused on various subjects of the homeowners, including education and corporate professionalism. Since the introduction of the Airbnb digital platform in 2007, over 4 million Airbnb hosts have opened their doors to over 1 billion guests worldwide among which a growing number of hosts are Black.
This study used perceived congruence as a framework to explore the impact on building trust and increasing booking intention on the Airbnb platform. The research relied upon quantitative inquiry methods to determine the drivers that influenced establishing trust and booking intention on the digital peer-to-peer platform, Airbnb. A survey instrument was developed and administered on the crowdsourcing platform Amazon Mechanical Turk (MTurk).
This survey instrument included replica Airbnb listings developed with the intention to indicate the race of the host based on visual illustrations, artwork, and name of host. This research revealed that race does matter when it comes to trust and booking intention. Both White and Black Airbnb guests were significantly influenced by images that provided cues to the race of the host. The goal of this research was to fill a gap in existing the existing literature dedicated to whitewashing, aid in the effort to better understand the mechanisms of consumer behavior on the Airbnb platform and examine the long-term ramifications of barriers that limit access for Black participants to the platform economy.
Keywords: Airbnb, shared economy, congruence, trust, purchasing intentio
(R2137) Smarandache Curved Ruled Surfaces and Their Characterizations According to Modified Orthogonal Frame in E^3
Full text linkIn this study, the ruled surfaces generated by Smarandache curves are expressed according to the modified orthogonal frame defined according to both curvature and torsion of the given unit speed curve in 3-dimensional Euclidean space; some special characterizations of these surfaces such as developability, striction curves, distribution parameters are given. In addition, some examples of these surfaces are given in graphical form. We use Maple to draw the graphs of the examples