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Controlling Chaos in an Axisymmetric RayleighBard Convection in a Cylindrical Enclosure with Variable Gravity Fields
The effect of variable gravity fields that vary through the height of a viscous fluid layer in an axisymmetric convection occupying a cylindrical enclosure heated from below is investigated for various radius-to-height ratios. Linear and nonlinear analyses are performed, which makes the present work the first of its kind. A minimal Fourier-series expansion leads to a boundary eigenvalue problem with variable coefficients. Using the Maclaurin-series approach, the recurrence relations for six cases of gravity fields, namely, positively linear, negatively linear, parabolic, cubic, bi-squared, and exponential gravity fields, are generated. The eigenvalue of the problem is located using the NewtonRaphson method with an error tolerance of 10?8 for idealistic and realistic boundary conditions. The scaled-Lorenz model obtained in this paper has newly defined nondimensional parameters that capture the influence of gravity fields and pave the way to examining the dynamical system. The control of chaos for this setup is implemented using various indicators. It is found that the effect of increasing the strength of gravity is to delay the appearance of chaos for all cases of gravity fields except for the positively linear case. Further, by varying the gravity fields, one can witness shifts in the chaotic and periodic regimes. Moreover, the before- and after-effects of going through a periodic regime are examined. In the absence of the gravity variation parameter, the results of the constant-gravity problem are recovered. Ultimately, the rectangular enclosure is studied as a limiting case of the cylindrical enclosure problem. 2026 World Scientific Publishing Company. -
Controlling Node Failure Localization in Data Networks Using Probing Mechanisms
In this paper, we prospect the potency of node failure localization in network communication from dual states (normal/fizzle) of the source to destination paths. To localize the failure nodes individually in the scheduled nodes, dissimilar path states must connect with various events of failure nodes. But, this situation is inapplicable or not easier to investigate or apply on enormous networks due to the obligation of any viable failure nodes. This objective is to deploy the set of adequate conditions for recognizing a set of failures in a set of arbitrary nodes which can be verified in a stipulated time. To avoid the above situation, probing mechanisms are assimilated additionally as a combination for network topology and locations of scrutinizes. Three probing mechanisms are considering which vary depending on measurement paths. Both the procedures can be transformed into single-node possessions by which they can be calculated effectively based on the given conditions. The exceeding measures are proposed for measuring the potency of failure localization which can be utilized for assessing the effect of different factors, which comprises topology, total monitors, and probing mechanisms. 2022, The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd. -
Controlling RayleighBard Magnetoconvection in Newtonian Nanoliquids by Rotational, Gravitational and Temperature Modulations: A Comparative Study
The effect of three different types of time periodic modulations on the RayleighBard magnetic system involving Newtonian nanoliquids is studied. Multiple-scale analysis (homogenization method) is used to arrive at the GinzburgLandau equation. The curiosity in the work is to know the individual effects of (1) rotation, (2) gravity and (3) temperature modulations on RayleighBard magnetoconvection in weakly electrically conducting Newtonian nanoliquids. A significant effort in this research is devoted toward linear and nonlinear stability analyses as well as the homogenization method which leads to the GinzburgLandau evolution equation. Although several studies have concluded similar results for nanoliquids compared with those of pure base fluids, many fundamental issues like the choice of phenomenological models for the thermo-physical properties and the best type of nanoparticles are not well understood. This research focuses on several important issues involving mathematical and computational problems arising in heat transfer analysis in the presence of nanoliquids. Effects of various nanoliquid parameters, frequency and amplitude of modulation on heat transport are analyzed. This investigation focuses on five nanoliquids, with water as a carrier liquid and five nanoparticles, viz. copper, copper oxide, silver, alumina and titania. Enhanced heat transport was observed for rotation, gravity and temperature modulations. In the case of rotation modulation, it is found that increase in the amplitude of modulation results in a decrease in the critical Rayleigh number and thereby to an increase in the mean Nusselt number. The increase in the amplitude of the gravity modulation is shown to enhance the heat transport, whereas increase in frequency is to inhibit the heat transport. Two types of temperature modulations are considered, viz. in-phase (synchronous) and out-of-phase (asynchronous) temperature modulations with the assumption that the boundary temperatures vary sinusoidally with time. The amplitudes of modulation are considered to be very small. In the case of in-phase modulation, there is no significant difference between the heat transports in the presence and in the absence of temperature modulation. On this reason, out-of-phase temperature modulation is used to either enhance or diminish heat transport by suitably adjusting the frequency and phase difference of the modulated temperature. The effect of magnetic field, in all three cases of modulations, is to inhibit the onset of convection and thereby diminish the heat transport. 2022, King Fahd University of Petroleum & Minerals. -
Controlling the Accuracy and Efficiency of Collision Detection in 2d Games using Hitboxes
Collision detection is a process in game development that involves checking if two or more objects have intersected or collided with each other. It is a fundamental aspect of game mechanics that cannot be overlooked. Games invloves assets/sprites, which tend to be drawn digitally with the help of a computer program. This paper discusses controlling and detecting collisions in games that make use of PNG images as game assets. The conventional way to detect collision in a game is to check if the object is within the bounding box of another object or asset. However, such a method lacks realism and doesn't work well with much complex shapes as the game might register a hit when another object collides with the transparent part of the object being checked for collision. In order to overcome these limitations, the proposed algorithm divides the entire image into smaller rectangles and stores its coordinates in an array. The array is then pruned by removing coordinates with no translucent or opaque elements. Collision is detected by checking if any of the points of the collision object is inside the image array. 2023 IEEE. -
Convection in a horizontal layer of water with three diffusing components
Triple diffusive convection in water is modelled with properties like density, specific heat, thermal conductivity, thermal diffusivity and thermal expansion, modified in the presence of salts. The GinzburgLandau equation is derived to study heat and mass transports of different combinations of salts in water. A table is prepared documenting the actual values of thermophysical properties of water with different salts and the critical Rayleigh number is calculated. This information is used in the estimation of Nusselt and Sherwood numbers and their relative magnitudes are commented upon. A detailed study on different single, double and triple diffusive systems is done and comparison is made of the results. The local nonlinear stability analysis made via a GinzburgLandau model mimics many properties of the original governing equations, namely, Hamiltonian character and a bounded solution. 2020, Springer Nature Switzerland AG. -
Convective heat and mass transports and chaos in two-component systems: comparison of results of physically realistic boundary conditions with those of artificial ones
Linear and weakly nonlinear stability analyses of double-diffusive convection in two-component liquids with either potassium chloride (KCl) or sodium chloride (NaCl) aqueous solution, and heat being present is investigated in the paper for free, and rigid, isothermal, iso-solutal boundaries. Using the thermophysical values of the aqueous solutions, we have shown that the stationary convection is the preferred mode at onset and that sub-critical motion is possible. We found that the critical thermal Rayleigh number for water+NaCl+heat is higher compared to that of water+KCl+heat. The study shows that for water+KCl+heat, the transition from convective motion to chaotic motion occurs at rH= 27.2 for free boundaries and at 48.5 for rigid boundaries. Here, rH denotes the Hopf thermal Rayleigh number. Further, the existence of windows of mildly chaotic points and fully periodic intervals are reported using Lyapunov exponents and bifurcation diagrams. Chaotic motions in both the aqueous solutions are nearly identical. The percentage increase in heat transport in the double-diffusive system involving NaCl is nearly 1% more than that of KCl in the case of free boundaries, whereas in the case of realistic boundaries it is nearly 1.6%. The comparison of the Nusselt and the Sherwood numbers between water+KCl and water+NaCl leads us to the conclusion that the aqueous solution with lower Lewis number transports maximum heat in the case of free boundaries and opposite is seen in the case of rigid boundaries due to the boundary effect. The many qualitative similarities between the results of artificial and realistic boundaries are highlighted. 2021, Akadiai Kiad Budapest, Hungary. -
Convective Heat Transfer in Maxwell- Cattaneo Dielectric Fluids
International journal of Computational Engineering Research Vol.3, Issue 3,pp. 347-355 ISSN No. 2250-3005 -
Convective instability analysis of couple-stress dielectric fluid saturated anisotropic porous medium with radiation effect
Purpose: The effects of anisotropy and radiation cannot be considered negligible while investigating the stability of the fluid in convection. Hence, the purpose of this paper is to analyze how these effects could affect the system while considering a couple-stress dielectric fluid. Therefore, the study establishes the effect of thermal radiation in a couple-stress dielectric fluid with an anisotropic porous medium using Goody's approach (Goody, 1956). Design/methodology/approach: To analyze the effect of radiation on the onset of convection, the MilneEddington approximation is employed to convert radiative heat flux to thermal heat flux. The equations are further developed to approximate for transparent and opaque medium. Stability of the quiescent state within the framework of linear theory is performed. The principle of exchange of stabilities is shown to be valid by means of single-term Galerkin method. Large values of conductionradiation and absorptivity parameters are avoided as fluid is considered as liquid rather than gas. Findings: The radiative heat transfer effect on a couple-stress dielectric fluid saturated anisotropic porous medium is examined in terms of MilneEddington approximation. The effect of couple-stress, dielectric, anisotropy and radiation parameters are analyzed graphically for both transparent and opaque medium. It is observed that the conductionradiation parameter stabilizes the system; in addition, the critical DarcyRayleigh number also shows a stabilizing effect in the absence of couple-stress, dielectric and anisotropy parameters, for both transparent and opaque medium. Furthermore, the absorptivity parameter stabilizes the system in the transparent medium, whereas it exhibits a dual effect in the case of an opaque medium. It was also found that an increase in thermal and mechanical anisotropy parameters shows an increase in the cell size, whereas the increase in DarcyRoberts number and conductionradiation parameter decreases the cell size. The validity of principle of exchange of stability is performed and concluded that marginal stability is the preferred mode than oscillatory. Originality/value: The effects of anisotropy and radiation on RayleighBard convection by considering a couple-stress dielectric fluid has been analyzed for the first time. 2020, Emerald Publishing Limited. -
Convective instability in a horizontal porous layer saturated with a chemically reacting Maxwell fluid
The problem of onset of convective instability in a horizontal inert porous layer saturated with a Maxwell viscoelastic fluid subject to zero-order chemical reaction is investigated by linear stability analysis. Modified Darcy-Maxwell model is used to describe the fluid motion. The horizontal porous layer is cooled from the upper boundary while an isothermal boundary condition is imposed at the lower boundary. Closed form solution pertaining to the basic quiescent state is obtained. The resulting eigenvalue problem is solved approximately using the Galerkin method. The Rayleigh number, characterizing the stability of the system, is calculated as a function of viscoelastic parameter, Darcy-Prandtl number, normalized porosity, and the Frank-Kamenetskii number. The possibility of oscillatory instability is discussed. 2013 AIP Publishing LLC. -
CONVECTIVE INSTABILITY IN POROUS MEDIA: IMPACT OF CHEMICAL REACTION ON MAXWELL-CATTANEO COUPLE-STRESS FERROMAGNETIC FLUIDS; [??????????? ??????????? ? ???????? ???????????: ????? ???????? ??????? ?? ?????????? ??? ?????????-???????? ? ????????????? ???????]
The current study analyzes the initiation of convection in a Maxwell-Cattaneo couple-stress ferrofluid within a porous layer, considering the effects of a chemical reaction. Small perturbations are applied to the fluid under the assumption of a zero-order energy release chemical reaction. The system is cooled from the upper layer while maintaining a steady temperature at the lower boundary. We employed linear stability analysis and determined Rayleigh number using the Galerkin Method (GM). This study emphasizes the influence of magnetic, chemical, Maxwell-Cattaneo, and couple-stress parameters on the initiation of ferro-convection. The findings indicate that both magnetic and chemical reaction parameters hasten the initiation of ferro-convection, while the porous medium and couple-stress parameters have a stabilizing effect. Notably, it is demonstrated that the destabilizing effects of chemical reactions and magnetic stresses can be effectively regulated in the presence of couple-stresses. The solutions provide insights into the potential application of ferromagnetic fluids for controlling efficient heat transfer mechanisms. 2024 Oles Honchar Dnipro National University. -
Convergence of Health Expenditure and Health Outcomes in Central Europe and the Baltic Region
This research work examines the convergence of health expenditure in Central Europe and the Baltic region. The study reveals the absolute convergence in per capita health expenditures, indicating similar health outcomes for all eleven countries of the region. However, there is a divergence in health expenditure and outcomes across the eleven countries. Notably, public health expenditure diverges in Denmark, Estonia, Finland, and Norway, while, private health expenditure converges in Poland, Russia, and Sweden. Despite an overall convergence in life expectancy at birth across the countries, mortality rates due to non-communicable diseases only converge in Estonia. 2024 Taylor & Francis Group, LLC. -
Convergence of Health Expenditure and Health Outcomes in Central Europe and the Baltic Region
This research work examines the convergence of health expenditure in Central Europe and the Baltic region. The study reveals the absolute convergence in per capita health expenditures, indicating similar health outcomes for all eleven countries of the region. However, there is a divergence in health expenditure and outcomes across the eleven countries. Notably, public health expenditure diverges in Denmark, Estonia, Finland, and Norway, while, private health expenditure converges in Poland, Russia, and Sweden. Despite an overall convergence in life expectancy at birth across the countries, mortality rates due to non-communicable diseases only converge in Estonia. 2024 Taylor & Francis Group, LLC. -
Convergence of retail banking interest rates to households in euro area: time-varying measurement and determinants
This study measures time-varying progress of retail banking (to households) interest rates convergence and examines its determinants for twelve countries of the euro area, between 2003 and 2014. First, we measure convergence of interest rates using five different time-varying indicators, namely asymmetric dynamic conditional correlation (ADCC), beta convergence, sigma convergence, variance ratio, and dynamic cointegration. We then estimate panel regressions for each type of interest rate to identify the determinants of convergence over pre-crisis and crisis periods. The estimated ADCC is employed as the dependent variable and explanatory variables measure potential macroeconomic, external linkages, industry-specific, institutional and sociological determinants. The results reveal that convergence is weak and heterogeneous across sub-periods (pre-crisis and crisis), economic groups (core and periphery), product type (savings and credit) and products maturities (short, medium and long). Among the fundamental determinants, inflation, output correlation, and sociological factors strongly impact convergence, however, the explanatory power of determinants weakens during the crisis period. 2019, Springer-Verlag GmbH Germany, part of Springer Nature. -
Convergence of retail banking interest rates to households in euro area: Time-varying measurement and determinants /
International Economics and Economic Policy, Vol.17, Issue 1, pp.25-65 -
Convergent replicated data structures that tolerate eventual consistency in NoSQL databases
The Eventual consistency is a new type of database approach that has emerged in the field of NoSQL, which provides tremendous benefits over the traditional databases as it allows one to scale an application to new levels. The consistency models used by NoSQL database is explained in this paper. It elaborates how the eventually consistent data structure ensures consistency on storage system with multiple independent components which replicate data with loose coordination. The paper also discusses the eventually consistent model that ensures that all updates are applied in a consistent manner to all replicas. 2013 IEEE. -
Converging Deep Learning and Cloud Computing: A Scalable and Efficient Approach for Modern AI Infrastructure
Deep learning has proven to be a powerful approach to solving challenging problems, ranging from natural language processing, speech recognition, to computer vision. The proposed model has capable of matching the expanding amount of facts as well as complexity of the algorithms is demands of deep researching methodologies. These demands cannot be met with traditional computing environments. This is why cloud computing technologies have developed, offering a scalable and affordable alternative for executing deep learning algorithms. Cloud computing platforms provide the resources necessary to run deep learning workloads including compute, storage, and networking. This means you no longer have to spend lots of money on expensive hardware and makes it easier for teams and researchers to deploy and train deep learning models faster. Cloud computing has ushered in a new era of deep learning developments by mobilizing the power of specialized hardware, notably GPUs, to accelerate the training and performance of deep learning models. 2025 IEEE. -
Conversational Agents and Chatbots: Current Trends
Languages facilitate the communication and interaction process among people. Computers learn to communicate with humans intelligently with the help of conversational agents and chatbots based on Natural Language Processing (NLP). Conversational agents and chatbots are gaining popularity in various applications. The development of chatbots or conversational agents is tightly coupled with an organizations customer service requirement. However, the background procedures that power the bots brain are more or less dependent on Artificial Intelligence-based processes. NLP mechanisms powered by various Deep Learning techniques are often used in the training and development of such intelligent agents. These bots inevitably become more competent as they interact with more people. The interactions between a customer and the bot are usually used as data in further training iterations. Chatbots are likely to respond with faster and more precise suggestions leading to solutions for frequently asked questions. Therefore, the current trends indicate the need for a supplementary system rather than substituting human agents existing customer service. The customer experience and intelligence of the chatbots are improved with the help of data analysis and training with the use of Deep Learning techniques. The chapter covers the current trends of conversational agents and chatbots, how the various Artificial Intelligence techniques have transformed the development of multiple architectures of these intelligent systems, and it compares the different state-of-the-art NLP-based chatbot architectures. 2024 selection and editorial matter, Anitha S. Pillai and Roberto Tedesco. -
Conversion of alkynes into 1,2-diketones using HFIP as sacrificial hydrogen donor and DMSO as dihydroxylating agent
A metal-free and hypervalent iodine free conversion of internal alkynes into 1,2-diketo compounds has been described. The efficacy of the present protocol rely on the use of HFIP (1,1,1,3,3,3-Hexafluoro-2-propanol) as reducing agent of alkynes and DMSO as dihydroxylating agent of olefins to acquire the desired chemical transformations. The obtained 1,2-diketones were further transformed into useful derivatives. 2020 Elsevier Ltd -
Convolutional Autoencoder Based Feature Extraction and KNN Classifier for Handwritten MODI Script Character Recognition
Character recognition is the process of identifying and classifying the images of printed or handwritten text and the conversion of that into machine-coded text. Deep learning techniques are efficiently used in the character recognition process. A Convolutional Autoencoder based technique for the character recognition of handwritten MODI script is proposed in this paper. MODI script was used for writing Marathi until the twentieth century. Though at present, Devnagari is taken over as the official script of Marathi, the historical importance of MODI script cannot be overlooked. MODI character recognition will not be an easy feat because of the various complexities of the script. Character recognition-related research of MODI script is in its initial stages. The proposed method is aimed to explore the use of a deep learning-based method for feature extraction and thereby building an efficient character recognition system for isolated handwritten MODI script. At the classification stage, the features extracted from the autoencoder are categorized using KNN classifier. Performance comparison of two different classifiers, such as KNN and SVM, is also carried out in this work. 2021, The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd. -
Convolutional bi-directional autoencoder assisted generative adversarial de-blurring framework for palm leaf character analysis
Palm leaf manuscripts have historically educated people on a variety of topics, including astronomy, mathematics, astrology and medicine. These manuscripts are constructed from dried palm leaves, which contain a wealth of information that remains largely untapped due to the challenges of digitalization and transcription. Recognizing the characters found in palm leaf manuscripts is a complex problem because blurred images of these manuscripts often conceal critical information. The present study proposes an automated de-blurring model to effectively identify exact Malayalam characters in palm leaf manuscripts. The input images are gathered from a real-time dataset to address this challenge. The Weighted Guided Image Filtering (WG_IF) method is employed to extract the detail layer, which not only reveals important information about the characters but also eliminates unwanted noise. The detailed layer is then input into the proposed Convolutional Bi-directional AutoEncoder assisted Generative Adversarial De-blurring (CBiAE_GADeblur) framework. This framework comprises two main blocks: the generator and the discriminator. The generator block uses the Convolutional Bi-directional Long Short Term Memory with AutoEncoder (CBLSTM_AE) method to produce de-blurred images. The discriminator block classifies these images as real or fake, enhancing the prediction accuracy of the palm characters. The proposed method demonstrates a superior accuracy rate of 98.25% in Prasavachikilsa and Vishavydyam datasets and exhibits lower time complexity. The motivation behind this research is to overcome the significant barriers posed by blurred palm leaf images, thereby unlocking and preserving the invaluable knowledge contained within these historical documents. Indian Academy of Sciences 2025.