Advances in Systems Science and Applications 2021-01-01T13:53:18+00:00 Natalya Pavlova Open Journal Systems <p><strong><em>Advances in Systems Science and Applications </em></strong><strong>(<em>ASSA</em>) </strong>is an international peer-reviewed open-source online academic journal. Its&nbsp;scope covers all major aspects of systems (and processes) analysis, modeling, simulation, and control, ranging from theoretical and methodological developments to a large variety of application areas. Survey articles and innovative results are also welcome.</p> <p>ASSA is aimed at the audience of scientists, engineers and researchers working in the framework of these problems. ASSA should be a platform on which researchers will be able to communicate and discuss both their specialized issues and interdisciplinary problems of systems analysis and its applications in science and industry, including data science, artificial intelligence, material science, manufacturing, transportation, power and energy, ecology, corporate management, public&nbsp;governance, finance, and many others.</p> An Algorithm to Search for All Minimal Cuts in a Flow Network 2021-01-01T13:53:18+00:00 Majid Forghani-elahabad Nezam Mahdavi-Amiri <p>Reliability evaluation approaches exploit a variety of tools for system modeling and calculation of reliability indices. Most proposed approaches in the literature are in terms of minimal cuts (MCs) or minimal paths. Hence, finding all the MCs in a network is an attractive problem in network flow and reliability theory. Here, investigating some works related to the MC problem, we first point out a number of defects in certain proposed algorithms, and present certain new techniques to rectify the flaws in two algorithms. Moreover, we present some techniques to improve the algorithms. Using our results, we propose an improved algorithm for finding all the MCs in a flow network. A benchmark network example is used to illustrate the performance of the algorithm. The proposed algorithm is shown to be correct. Finally, after establishing the complexity results, we demonstrate the proposed algorithm to be more efficient than some existing algorithms.</p> 2021-01-01T08:25:16+00:00 ##submission.copyrightStatement## Frequency-Geometric Identification of Magnetization Characteristics of Switched Reluctance Machine 2021-01-01T13:53:18+00:00 Laila Kadi Adil Brouri Abdelmalek Ouannou <p>Accurate modeling of electrical drives for online testing is a relevant problem. Switched Reluctance Machine (SRM) has lately attracted significant attention because it has several advantages compared to conventional engines. It is simple, free of rare-earth and fault-tolerant machine. An analytical model of a SRM has not been reported yet due to the dynamic and strong nonlinearity of SRM. The most SRM control and applications are based on several assumptions and simplifications. Therefore, it is convenient to develop an accurate approach to identify the SRM characteristics. In this paper, an analytical modeling and identification method of magnetization characteristics of Switched Reluctance Machine (SRM) is proposed. Presently, an exact mathematical model of SRM is established. Unlike several previous studies, in this approach the system nonlinearities of SRM are allowed to be hysteresis (i.e. the hysteresis effect is considered) and taking account the inherent magnetic nonlinearity. Indeed, the SRM is considered as highly nonlinear which makes the modeling of these machines difficult to achieve. Then, it is convenient to develop an accuracy model of SRM because it is always operated in the magnetically saturated mode to maximize the energy transfer. The developed model can be used in control, simulation and design development. Furthermore, an identification method, at standstill test, based on frequency technics is developed allowing the identification of SRM nonlinearities (considering the saturation and the hysteresis effects). In this respect, it is shown that the nonlinear behavior of SRM can be exactly described by a block-oriented nonlinear structure. Specifically, the SRM can be described by a Wiener nonlinear model. Compared to the existing methods, the proposed study gives good accuracy of flux-linkage value characteristics and enjoys the simplicity of implementation.</p> 2021-01-01T08:25:47+00:00 ##submission.copyrightStatement## Determining the Vertical Force When Steering 2021-01-01T13:53:18+00:00 Anh Nguyen Tuan Binh Hoang Thang <p>When the vehicles move at high velocity and quickly steer, the vehicles can be rollover. The first sign of this phenomenon is that two wheels on the same side are completely separated from the road surface. The typical value for this sign is the vertical force F<sub>Z</sub> at each wheel. If this value gradually decreases to zero, the wheel runs the risk of separating from the road surface that may lead to rollover. Therefore, the value of the vertical force Fz in different conditions needs to be determined to detect the imminent limit of the rollover phenomenon. This research established the spatial dynamic model of the vehicle to determine the vertical force F<sub>Z</sub> based on the simulation method. Besides, the equation describing the relationship between vertical force F<sub>Z</sub>, velocity v, and acceleration steering e corresponding to the value of steering angle d is also established by the calculation process. From this equation, the value of the vertical force F<sub>Z</sub> can be simply calculated with relatively high accuracy based on determining conditions. The results of this research are the basis for determining and establishing the vehicle's rollover limit.</p> 2021-01-01T08:26:09+00:00 ##submission.copyrightStatement## Statistical Properties of VANET-based Information Spreading 2021-01-01T13:53:18+00:00 Imre Varga Gergely Kocsis <p>In this work, we present a robust model of vehicular ad hoc networks (VANET) in order to study information spreading on such topologies. Vehicles are moving along the fastest routes between their starting points and their destinations on a map derived from a real urban topology. Vehicles can exchange information through the use of short-range wireless communication devices. The source of information is a roadside unit which provides packets for the nearby vehicles. These agents can carry and forward messages for others. As a result of the data dissemination, the major part of the system becomes informed quite quickly. Presented results include the investigation of information spreading in the system, e.g. the time evolution of the average awareness, the age distribution of information owned by separate vehicles and the statistical properties of time intervals between information exchange events. It has been shown how the effectiveness of this complex system depends on the density of intelligent devices. Scale-free behavior was found by time series analysis. Our computer simulation results can help to design smart-city applications of the future.</p> 2021-01-01T08:26:24+00:00 ##submission.copyrightStatement## Computational Models of Trajectory Investigation of Marine Geophysical Fields and Its Implementation for Solving Problems of Map-Aided Navigation 2021-01-01T13:53:18+00:00 L. V. Kiselev V. B. Kostousov A. V. Medvedev A. E. Tarkhanov K. V. Dunaevskaya <p>Comprehensive investigations of geophysical fields (GPF) of the ocean are among the top priority problems in underwater robotics. Problems reside in developing automated systems capable of real-time operation for gathering, accumulating, and processing diverse geophysical information. The data’s total volume is applied for long-term or real-time monitoring of marine areas, environment or objects surveillance, mapping certain regions, or anomalies in geographical coordinates. One of the main elements of such systems is the computational models sensitive to properties of geophysical fields, features of search routes of underwater vehicles, and particular aspects of missions performed during trajectory measurements and features of navigational support tasks. The work considers computational models of comprehensive interpretation of the results of trajectory measurements of geophysical fields using an autonomous underwater vehicle (AUV), and estimation of accuracy of map-aided navigation on the reconstructed map of geophysical fields. Algorithms and software consider distinctive features of representation of bathymetry, magnetometry, and gravimetry data visualized in 2D and 3D. Algorithm of map-aided navigation by the reconstructed fields is discussed. The final assessments of the considered models’ accuracy consider averaged errors of measurements, mapping, and inertial navigation. Obtained assessments are based on theoretical investigations, results of model experiments, and experimental trials of AUV’s systems under actual operating conditions.</p> 2021-01-01T08:26:42+00:00 ##submission.copyrightStatement## Multi-Criteria Estimation of Input Parameters in Natural Gas Quality Analysis 2021-01-01T13:53:18+00:00 Ivan Brokarev Sergei Vaskovskii <p>In this paper, we present a method for assessing input parameters in a statistical model used for the quality analysis of the natural gas. The analysis is done by measuring physical quantities of natural gas through the hierarchy analysis, compromise programming, correlation analysis and assessing the practical possibility of measuring selected input physical quantities by available means. The problems arising when selecting input parameters are also considered. The results are compared with the previously obtained results of the model input parameters correlation analysis in order to improve the developed system for natural gas quality analysis. The proposed method is applied to assess input parameters for certain samples of natural gas based mixtures. Based on the results of the multicriteria assessment, the speed of sound, thermal conductivity and concentration of carbon dioxide were selected as input parameters for the developed natural gas quality analysis system.</p> 2021-01-01T08:27:17+00:00 ##submission.copyrightStatement## Multi-Valued Neural Networks II: A Robot Group Control 2021-01-01T13:53:18+00:00 Dmitry Maximov <p>For the new concept of a multi-valued neural network introduced earlier, an analogue of the T-norm in fuzzy mathematics is considered. In the multi-valued neural network, all variables are elements of the lattice of linguistic variables, i.e., they are all only partially-ordered. The lattice operations are used to build the network output by inputs. However, a lattice elements' multiplication may also be used to determine such operations in the case when not all of them are allowed by the lattice construction. In this paper, the lattice is assumed to be residuated, and the residual construction gives the analogue of a T-norm. The lattice elements' multiplication determines the implication which is used, together with other lattice operations, in output determining of the neural network. Though, such a construction determines a multi-valued associative memory similar to the Brouwer lattice case considered earlier, this variant is more natural to use in the Kohonen-like networks that we demonstrate with the example of a robot group management.</p> 2021-01-01T08:27:32+00:00 ##submission.copyrightStatement## On Optimal Therapy Protocols in the Mathematical Model of Prostate Cancer Progression 2021-01-01T13:53:18+00:00 Marie-Christin Litzinger Y. Todorov Miriam Foller-Nord Manitjaiswal K. Chaudhary Alexander S. Bratus <p>A mathematical model for the treatment of prostate cancer regarding androgen ablation is considered. The effect of the therapy on healthy cells is taken into account and modelled as a second order state constraint. A mathematical overview about possible therapy strategies is presented.</p> 2021-01-01T08:27:56+00:00 ##submission.copyrightStatement## Automation of Cluster Large-Scale Production Systems 2021-01-01T13:53:18+00:00 Valentin Chadeev Natalya Aristova <p>The paper covers the рroduction of capital goods of various types of industrial robots in the context of industrial clusters. It uses a model of production, invariant with the types of technological operations (TOs). The paper examines algorithms for three automation options: full рroduction of capital goods, partial рroduction of capital goods, use of robots purchased outside the cluster.</p> 2021-01-01T08:28:18+00:00 ##submission.copyrightStatement## Development of Unified Approaches to Building Neural Network and Mathematical Models Based on Digital Data 2021-01-01T13:53:18+00:00 Nailia Gabdrakhmanova Maria Pilgun <p>The paper considers the problem of developing approaches to building mathematical models based on digital data of real objects. The data are in text format and contains information about the behavior of the dynamic system. The information selected from the text data enables building of neural network and mathematical models of the dynamic system. The adequacy of the models is evaluated by analytical and numerical methods. The results are meaningfully interpreted. As a result of the study, it was confirmed that the algorithms and approaches for building mathematical models to solve the considered range of problems using digital data can be unified. The analysis of the obtained solutions showed that the con-clusions drawn on the basis of the built mathematical models and the conclusions drawn with the se-mantic neural network analysis of texts are consistent with each other. Therefore, one can talk about the positive results of the models developed. The models developed can be used in solving managerial tasks, planning and situation prediction.</p> 2021-01-01T08:28:34+00:00 ##submission.copyrightStatement## On Some Global Properties of Multivalued Simple Waves 2021-01-01T13:53:18+00:00 Dmitry V. Tunitsky <p>The Cauchy problem for one-dimensional quasilinear wave equation is considered. In the case that its solutions are multivalued simple waves, we derive explicit expressions in quadratures&nbsp;by introducing global characteristic coordinates. The main result of the paper is a theorem on some global properties of multivalued simple waves.</p> 2021-01-01T08:28:51+00:00 ##submission.copyrightStatement##