WSEAS TRANSACTIONS ON COMPUTERS
Latest Publications


TOTAL DOCUMENTS

73
(FIVE YEARS 73)

H-INDEX

0
(FIVE YEARS 0)

Published By World Scientific And Engineering Academy And Society (WSEAS)

1109-2750

2022 ◽  
Vol 21 ◽  
pp. 44-50
Author(s):  
Valeriy Kozytskyy ◽  
Nelya Pabyrivska ◽  
Galyna Beregova

The economies of almost every country in the whole word have been suffered from coronavirus pandemic consequences. The damage was especially hard for labor markets. The large magnitude of demand and production shocks that was caused by COVID-19 significantly disturbed the dynamics of output, wages and prices. The research problem addressed in this paper focuses on dynamic properties of wages and prices behavior influenced by shocks with different magnitudes and types. We apply a system dynamic approach to conduct the simulations of economic variables and investigate the possibility of their convergence to some stable path. We examine the impact of demand and production shocks on the output and prices as well as on wage and inflation behavior. It is proved that values of models parameters are crucial for existing of new steady state and convergence of economic variables. The paper determines the bifurcation points that separate different modes of transition period in moving towards or away from equilibrium. The research includes the investigation of the impact of economy’s original state and emphasizes the importance of initial point of the system for the next its dynamics after shock. The research results derived in the paper serves as a useful learning tool to develop a discussion of the policy design issues related to reduction of negative impact of severe and unanticipated disturbance like COVID-19.


2022 ◽  
Vol 21 ◽  
pp. 10-17
Author(s):  
Alexander Zemliak

The design process for analogue circuit design is formulated on the basis of the optimum control theory. The artificially introduced special control vector is defined for the redistribution of computational costs between network analysis and parametric optimization. This redistribution minimizes computer time. The problem of the minimal-time network design can be formulated in this case as a classical problem of the optimal control for some functional minimization. There is a principal difference between the new approach and before elaborated methodology. This difference is based on a higher level of the problem generalization. In this case the structural basis of design strategies is more complete and this circumstance gives possibility to obtain a great value of computer time gain. Numerical results demonstrate the effectiveness and prospects of a more generalized approach to circuit optimization. This approach generalizes the design process and generates an infinite number of the different design strategies that will serve as the structural basis for the minimal time algorithm construction. This paper is advocated to electronic systems built with transistors. The main equations for the system design process were elaborated.


2022 ◽  
Vol 21 ◽  
pp. 23-30
Author(s):  
E. M. Karanikolaou ◽  
M. P. Bekakos

The need for new and more reliable metrics is always in demand. In this paper, a new metric is proposed for the evaluation of high performance computing platforms in conjunction with their energy consumption. The aim of the new metric is to reliably compare different HPC systems concerning their energy efficiency. The metric provides a mean to rank supercomputers of similar capabilities, avoiding the misleading results of metrics like performance-per-watt, currently used for ranking systems, as in the Green500 list, where systems with totally different sizes and capabilities are ranked consecutively. An example of this misuse for two adjacent systems in the Green500 list, is discussed. A comparative study for the energy efficiency of three high performance computing platforms, with different architectures, using the proposed metric is presented.


2022 ◽  
Vol 21 ◽  
pp. 18-22
Author(s):  
Tain-Sou Tsay

A digital controller for exact command tracking control without integration is derived from a periodic series. The ratios of adjacent values will be converged to unities after the output has tracked the reference input command. Integration in control loop usually introduces phase lag to slow command response and degrade performance.


2022 ◽  
Vol 21 ◽  
pp. 31-43
Author(s):  
Rhouma Mlayeh

This paper provides protocols for finitetime average consensus and finitetime stability of systems with controlled nonlinear dynamics innetwork under undirected fixed topology. Each node’s state is a high dimensional vector as a solution of the highly nonlinear first order dynamics with and without drift terms. This paper provides protocols for finitetime average consensus and finitetime stability of systems with controlled nonlinear dynamics innetwork under undirected fixed topology. Each node’s state is high Under the proposed interaction rules, agreements as a common average value or an average trajectory are reached, solving finitetime average consensus and the multisystem equilibrium is controlled leading to the finitetime stability of each system origin. Sufficient conditions are achieved using the Lyapunov techniques and the graph theory. In networked dynamic systems, the theoretical results of the paper cover a large class of underactuated autonomous systems as formation flight, multivehicle coordination, and heterogeneous multisystem behaviors. Some examples are introduced in simulation which approves the proposed protocols.


2022 ◽  
Vol 21 ◽  
pp. 1-9
Author(s):  
N. A. Tseligorov ◽  
A. I. Ozersky ◽  
A. V. Chubukin ◽  
E. N. Tseligorova

The paper considers the problem of developing a digital system for an induction motor speed control which has a sensor and a speed regulator to increase accuracy of speed control. Speed control is carried out by a scalar method due to consistent change in the stator frequency and voltage. To obtain the uniformity of the motor overload capability in a given range the control mode is used associated with maintaining uniformity of flux linkage of the motor stator. Induction motor scalar models do not possess high accuracy and their parameters and their parameters can vary over a wide range, which complicates the controller design and achievement of robustness of the speed control system. To eliminate these disadvantages, it is proposed to use a vector model in a rotating coordinate system having subjected it to linearization at different points of the operating mode with the account of the adopted law of frequency control, to ensure robust absolute stability of the system on the basis of application of a graphical method for constructing a modified amplitude-phase characteristic.


2021 ◽  
Vol 20 ◽  
pp. 362-371
Author(s):  
Alexander Zemliak

The minimization of the processor time of designing can be formulated as a problem of time minimization for transitional process of dynamic system. A special control vector that changes the internal structure of the equations of optimization procedure serves as a principal tool for searching the best strategies with the minimal CPU time. In this case a well-known maximum principle of Pontryagin is the best theoretical approach for finding of the optimum structure of control vector. Practical approach for realization of the maximum principle is based on the analysis of behavior of a Hamiltonian for various strategies of optimization. The possibility of applying the maximum principle to the problem of optimization of electronic circuits is analyzed. It is shown that in spite of the fact that the problem of optimization is formulated as a nonlinear task, and the maximum principle in this case isn't a sufficient condition for obtaining a minimum of the functional, it is possible to obtain the decision in the form of local minima. The relative acceleration of the CPU time for the best strategy found by means of maximum principle compared with the traditional approach is equal two to three orders of magnitude.


2021 ◽  
Vol 20 ◽  
pp. 352-361
Author(s):  
Xiang Lin

In the big data environment, the visualization technique has been increasingly adopted to mine the data on library and information (L&I), with the diversification of data sources and the growth of data volume. However, there are several defects with the research on information association of L&I visualization network: the lack of optimization of network layout algorithms, and the absence of L&I information fusion and comparison in multiple disciplines, in the big data environment. To overcome these defects, this paper explores the visualization of L&I from the perspective of big data analysis and fusion. Firstly, the authors analyzed the topology of the L&I visualization network, and calculated the metrics for the construction of L&I visualization topology map. Next, the importance of meta-paths of the L&I visualization network was calculated. Finally, a complex big data L&I visualization network was established, and the associations between information nodes were analyzed in details. Experimental results verify the effectiveness of the proposed algorithm


2021 ◽  
Vol 20 ◽  
pp. 321-328
Author(s):  
Sergiy Prykhodko ◽  
Ivan Shutko ◽  
Andrii Prykhodko

We have performed early LOC estimation of Web applications (apps) created using the Yii framework by three nonlinear regression models with three predictors based on the normalizing transformations. We used two univariate transformations (the decimal logarithm and the Box-Cox transformation) and the Box-Cox four-variate transformation for constructing nonlinear regression models. The nonlinear regression model constructed by the Box-Cox four-variate transformation has better size prediction results compared to other regression ones based on the univariate transformations.


2021 ◽  
Vol 20 ◽  
pp. 329-351
Author(s):  
Ahmed Al-Ashaab ◽  
Zehra Canan Araci ◽  
Muhd Ikmal I. Mohd Maulana ◽  
Cesar Garcia Almeida ◽  
Steve Young

Set-based concurrent engineering (SBCE), also known as set-based design, is a state-of-the-art approach to the new product development process. SBCE, simply, provides an environment where designers explore a wide range of alternative solutions in the early stages of product development. After gaining knowledge, solutions are narrowed down until the optimal solution is ensured. Such an environment saves considerable amount of cost and time while reaching innovation and high quality in the products. However, industrial practitioners seek a clear and systematic application throughout an SBCE process. This paper demonstrates a well-structured SBCE process model and its step-by-step application on a product called “electronic card reader”. Real data is used in the industrial case study. Results showed the benefits of applying SBCE in both the product, and the process of new product development.


Sign in / Sign up

Export Citation Format

Share Document