CENTRAL ASIAN JOURNAL OF MATHEMATICAL THEORY AND COMPUTER SCIENCES

Optimal Parameters of Dynamic Absorber for The Vibrations of The Beam With Moving Dynamic Absorber

Zarnigor Yuldoshova — 2025-11-04

Vibration control is of utmost importance in modern mechanical and structural engineering in which excessive oscillations can cause the failure of operations, noise, fatigue, or even the collapse of the structure. Dynamic vibration absorbers provide an effective, simple and energy-efficient solution for transferring vibrational energy of the primary system to the secondary subsystem, which reduces the amplitude of the main structure. Beams are highly common structures present in bridges, vehicles, robotics, and aircraft, which exhibit complex vibrations with dynamic or moving loads, such as that of a vehicle or a crane. Consequently, a moving DVA, which moves along the beam optimizing the suppression method is required, and with parameters such as mass ratio, damping, stiffness, and position liquidating the performance of the device on such system. Although DVAs are relatively well-developed, on beams with hysteresis-type elastic dissipative characteristics, under moving loads, improper tuning of the parameters can result in reduced functionality or even increase the vibrations of the structure at certain frequencies. Consequently, this study aims at finding such optimal parameters for moving DVA on a beam and absorber with hysteresis-type elastic dissipative characteristics using purely analytical methods. As a result, the optimization allowed to reduce the amplitude and energy transmission, the parameters for which were equal to 0.1253, 1.92 and 0.5 respectively. The results were obtained through analytical modeling, resonant analysis and the Den Hartog method, were at- and transmitted power were equal to zero, are used to find the transfer function equations and the invariant points of the system under kinematic and random excitations. Numerical analysis provided optimal mass, stiffness, and damping for the moving DVA on a clamped end steel beam. The amplitude-frequency characteristic results are highlighted in that transmission is limited in the vicinity of the resonant frequencies, and the curves are shifted to the right with absorber tuning when moving and the peaks are the lowest. The work is unique in its kind as it performs such optimization using the Ginzburg method and analytical methods in order to achieve optimal suppression rather than rely on the experiment only. Results of the study can be applied to optimize values of DVAs on hysteresis beam for vibration-sensitive structures like robotic arms and high-speed railways, in order to employ maximum suppressional capabilities of the device under dynamic excitations.

Mitigating Security Risks in Multi-Cloud Environments: A Blockchain-Enabled Zero Trust Architecture for Resilient Information Systems

Mohanad Ali Hussein — 2025-11-19

Multi-cloud computing environments are emerging as a standard in business settings but present much greater security challenges such as the lack of access control fragmentation, audit transparency, complexities of trust boundaries, and vulnerability to single point of failure due to centralized authentication systems. The article proposes a Zero Trust Architecture based on blockchain and the use of the Attribute-Based Access Control (ABAC) to have secure information systems in distributed multi-clouds. The suggested solution uses Hyperledger Fabric 2.5 and CouchDB state database to provide decentralized, immutable, and transparent access control by policy enforcement using smart contracts. Parallel transaction benchmarking was used to do overall performance testing on four test cases with 1,700 transactions with different concurrent loads (2-10 concurrent workers). The experimental data shows production grade level performance with the maximum throughput of 30.78 TPS, mean latency of 85.79 ms, and the best in class reliability (100% success rate). The system is highly linearly scalable with a 5.2x throughput increase between low and high load conditions, and surprisingly 80 percent reduction in the latency during heavier concurrent load conditions. It has made significant contributions, including: (1) production-quality ABAC smart contract deployment on modern blockchain platforms, (2) extensive performance testing by industry-standard parallel benchmarking methodology, (3) demonstration of successful practicability of real multi-cloud security deployments, (4) reproducible experimental setup with open-source deliverables, and (5) closing the theory-practice gap between theoretical blockchain-based access control models and realistic implementation that is suitable to security-critical enterprise settings where immutable audit logs and principles of Zero Trust are needed.

Modified Principal Points: A Flexible and Differentiable Approach for Data Summarization

Thaer Ziara Arzig — 2025-11-18

Principal points∗are a small set of characteristic locations which minimize the average squared Euclidian distance from the data points, and should be more informative about the data’s structure than simple features such as mean and variance. However it is also non-differentiable w.r.t point collapse due to minimum operation in (2.8) and weak-sparse in defining point spread penalty. In this paper we define the generalized principal points as the Gaussian weighted mean of distances. It results in a differentiable objective and has a tuning parameter for point closeness adjustment. When the bandwidth approaches to zero, modified points tend towards classical points from a real direction and when it tends to the infinity they define the mean. Finally, the simulation studies are reported and reveal higher robustness of our proposed methods against outliers, non-normality, and small sample sizes. Empirical studies on real statistical data also confirm that lower sensitivity to extremes is better

Utilizing The Time Series Model for Electricity Energy Consumption Prediction In Kirkuk Governorate, Iraq

Ahmed Shamar Yadgar — 2025-11-18

Correctness in the prediction of electrical consumption is essential as it allows for efficient utilization of energy without incurring excess cost or suffering from power outages. Many countries, including Iraq, have faced challenge in precise demand forecasting due to rising population, climate challenges and other factors. Despite several studies studying the energy prediction breake the time series models, but, in Kirkuk the dynamics of temperature, population growth and electricity consumption is not investigated in detail. The goal is to deploy VAR model for electricity consumption forecasting in Kirkuk while controlling for population and temperature influencing demand. The results present by the VAR model confirmed that population growth positively correlated with electricity consumption. This is especially handy because these two variables, energy demand and temperature, are interrelated over time. This study formulates a new forecasting model for Kirkuk, Iraq, using an advanced VAR (Vector Autoregressive) model with optimal lag order to produce the best possible forecast, particularly since large cities have their own special demographic and environmental factors. The results can provide for better management of the power grid which can inform the energy policies and infrastructural development in Kirkuk to better cater to the future electricity demands.

A Hybrid Movie Recommendation System Using Collaborative and Content-Based Filtering Techniques

N. Selvam — 2025-11-21

As the number of digital media content grows quickly, it is getting harder to find films that are timely and fit your tastes. This research describes how to develop and build a movie recommendation system that employs data filtering techniques to give each user customised movie suggestions. The system uses content-based filtering, collaborative filtering, or a combination of the two to look at user preferences and movie information. The algorithm uses user ratings, genre data, and viewing history to guess which films people will like and suggest them. This study looks at the system's design, algorithms, data pretreatment methods, and ways to measure performance. The implementation demonstrates that recommendation systems can provide significant value, sustain user interest, and enhance the entertainment experience. To see how accurate, scalable, and user-friendly the system is, a dataset from the actual world is used. To judge how good the ideas are, we look at performance metrics like precision, recall, and RMSE. Improvements in algorithms and hybridisation procedures help solve problems including scalability, cold start, and data sparsity. The article also talks about what will happen in the future, such as using deep learning models to make predictions more accurate, adding real-time recommendation capabilities, and integrating streaming services. Overall, the Movie Recommendation System looks like a good way to go at large media archives.

Ultra-Compact Cryptographic Engineering for the Internet of Things: Enhancing Security in Highly Constrained Environments

Ahmed Nashaat Shakir — 2025-11-30

This paper will design a cryptography framework intended to work within extremely lightweight and resource-constrained IoT implementation environments. Its goal is to design a secure and computationally efficient system that will be able to protect the large-scale IoT systems that support the critical infrastructure like healthcare systems, industrial sensors, and smart cities applications. The suggested architecture is a combination of algorithmic design, simulation, and hardware evaluation with the platform that has FPGA and ARM Cortex-M microcontrollers to evaluate the performance of the proposed architecture in real-world conditions. The model has been largely tested, showing substantial energy use (up to 40% of original power usage), increased throughput (up to 30% more), and lower latency (reduced by 20-50%) than more traditional cryptographic standards like AES and PRESENT. These findings establish lightweight encryption as viable with respect to protecting the IoT ecosystems without compromising the cryptographic strength. The area of this study puts its contribution in the context of the current digital transformation of Iraq, drawing on the framework of information-system compatibility of organizational readiness model. It is through such regional inferences that the paper suggests a framework of cryptography, which is engineering-oriented, enabling safe, energy-conscious, and scalable information exchange among national e-management systems. The results support the notion that ultra-lightweight cryptographic engineering can be used as a foundation to developing economies in order to support the development of secure, sustainable, and interoperable digital infrastructures.