Model Of Real System Research Articles

Two-Point Resistance of a Non-Regular Cylindrical Network with a Zero Resistor Axis and Two Arbitrary Boundaries* *Supported by the Natural Science Foundation of Jiangsu Province under Grant No. BK20161278

We study a problem of two-point resistance in a non-regular m × n cylindrical network with a zero resistor axis and two arbitrary boundaries by means of the Recursion-Transform method. This is a new problem never solved before, the Green’s function technique and the Laplacian matrix approach are invalid in this case. A disordered network with arbitrary boundaries is a basic model in many physical systems or real world systems, however looking for the exact calculation of the resistance of a binary resistor network is important but difficult in the case of the arbitrary boundaries, the boundary is like a wall or trap which affects the behavior of finite network. In this paper we obtain a general resistance formula of a non-regular m × n cylindrical network, which is composed of a single summation. Further, the current distribution is given explicitly as a byproduct of the method. As applications, several interesting results are derived by making special cases from the general formula.

Trajectory refinement of three-body orbits in the real solar system model

In this paper, an automatic algorithm for the correction of orbits in the real solar system model is described. The differential equations governing the dynamics of a massless particle in the n-body problem are written as perturbation of the circular restricted three-body problem in a non-uniformly rotating, pulsating frame by using a Lagrangian formalism. The refinement is carried out by means of a modified multiple shooting technique, and the problem is solved for a finite number of trajectory states at several time instants. The analysis involves computing the dynamical substitutes of the collinear points, as well as several Lagrange point orbits, for the Sun–Earth, Sun–Jupiter, and Earth–Moon gravitational systems.

Fractional order linear time invariant system stabilization by brute-force search

Fractional calculus increases their applications in system design and analysis problems because of providing more realistic modeling of real systems. Owing to computational complexity of fractional calculus, the computer-aided design and analysis methods are required for engineering applications of fractional order systems. This study presents a numerical method for parametric robust stabilization of fractional order systems by employing single-parameter perturbation. This method implements a fractional order perturbation strategy on the basis of brute-force search technique for system stabilization problems. In order to meet a predefined minimum argument root design specification, the proposed algorithm searches for a desired placement of the minimum argument characteristic root within the first Riemann sheet by performing iterative perturbations of the fractional order. This approach can provide a straightforward numerical solution for robust stabilization problems of fractional order systems by employing an order perturbation scheme. Moreover, a possible utilization of a fractional order derivative operator as a system stabilizer is theoretically discussed. Illustrative examples show the utilization of the proposed stabilization algorithms for computer-aided fractional order system design applications.

Continuous multiplicative attribute graph model

Network modeling is an important approach in many fields in analyzing complex systems. Recently new series of methods have emerged, by using Kronecker product and similar tools to model real systems. One of such approaches is the multiplicative attribute graph (MAG) model, which generates networks based on category attributes of nodes. In this paper we try to extend this model into a continuous one, give an overview of its properties, and discuss some special cases related to real-world networks, as well as the influence of attribute distribution and affinity function respectively.

Entropy Management of Gaussian Stochastic Systems

Two approaches to the entropy management of Gaussian stochastic system are considered. The first approach is scalar and implements the concept of "growth points". In this case the problem of maximizing (increasing) or minimizing (decreasing) the system entropy is solved. The second approach is the vector management, allowing to ensure effective changing of the entropy of two-dimensional vector, the components of which are randomness and self-organization entropies. For vector control an optimization problem on the conditional extremum is formulated. This problem can be solved using penalty methods. It is shown that the vector management of entropy for a number of cases has advantages compared to the scalar management. Examples of entropy models of real stochastic systems are provided.

Обзор систем параллельной обработки заявок

This paper is the first in a series of two articles devoted to the review of “fork-join” (inthe western classification) queuing systems or systems with the splitting of incoming queries.This system is a natural model for many other real systems. The article describes the fork-joinqueueing model construction and main characteristics of this model. Special attention is paid tomethods of analysis of the response time of the system. Since the exact expression for the meanresponse time is known only for the case of two servers, the article gives a detailed descriptionof the approach to obtaining an accurate expression of this characteristic. For the case whenthe number of servers is more than two, approximations of the mean response time are obtainedby different methods, which is explained by the complexity of the studies due to the existingdependence between the queues of subqueries due to common arrival moments. The paperpresents several methods of approximate analysis: various variants of empirical approximation,i.e. methods that refine the obtained characteristics by using the results of simulation modeling;interpolation methods using system load limit values in cases when the incoming flow and servicetime distributions are not exponential.

Time Hierarchies and Model Reduction in Canonical Non-linear Models.

The time-scale hierarchies of a very general class of models in differential equations is analyzed. Classical methods for model reduction and time-scale analysis have been adapted to this formalism and a complementary method is proposed. A unified theoretical treatment shows how the structure of the system can be much better understood by inspection of two sets of singular values: one related to the stoichiometric structure of the system and another to its kinetics. The methods are exemplified first through a toy model, then a large synthetic network and finally with numeric simulations of three classical benchmark models of real biological systems.

A multi-orbital iterated perturbation theory for model Hamiltonians and real material-specific calculations of correlated systems

Perturbative schemes utilizing a spectral moment expansion are well known and extensively used for investigating the physics of model Hamiltonians and real material systems. The advantages they offer, in terms of being computationally inexpensive, with real frequency output at zero and finite temperatures, compensate for their deficiencies and offer a quick, qualitative analysis of the system behavior. In this work, we have developed a method, that can be classified as a multi-orbital iterative perturbation theory (MO-IPT) to study N-fold degenerate and non degenerate Anderson impurity models. As applications of the solver, we have combined the method with dynamical mean field theory to explore lattice models like the single orbital Hubbard model, covalent band insulator and the multi-orbital Hubbard model for density-density type interactions in different parameter regimes. The Hund's coupling effects in case of multiple orbitals is also studied. The limitations and quality of results are gauged through extensive comparison with data from the numerically exact continuous time quantum Monte Carlo method (hybridization expansion CTQMC). In general we observe that the agreement with CTQMC results gets better as we move away from particle-hole symmetry. We have integrated MO-IPT with density functional theory based electronic structure methods to study real material systems. As a test case, we have studied the classic, strongly correlated electronic material, SrVO$_3$. A comparison of density of states and photo emission spectrum (PES) with results obtained from different impurity solvers and experiments yields good agreement.

Offset-Free Model Predictive Control of an Open Water Channel Based on Moving Horizon Estimation

AbstractOpen water systems such as irrigation canals are used to transport and deliver water from the source to the user. Water loss in these systems by seepage, leakage, evaporation, or unknown water offtakes can be large. If this loss is unknown to the model used, it will not be considered by the controller and create a real system model mismatch. This mismatch will affect the water level directly and create an offset from the reference set point of the water level. A control configuration for open water canals, model predictive control (MPC) based on moving horizon estimation (MHE-MPC), to deal with offset problems resulting from real system-model mismatch is described in this paper. MHE uses the past predictions of the model and the past measurements of the system to estimate unknown disturbances and systematically removes the offset in the controlled water level. This control configuration is numerically tested on an accurate hydrodynamic model of the Control Algorithms Test Canal of the Technical Un...

센서리스 영구자석 동기전동기의 상태 추정을 위한 병렬 축소 차수 제곱근 무향 칼만 필터

This paper proposes a parallel reduced-order square-root unscented Kalman filter for state estimation of a sensorless permanent-magnet synchronous motor. The appearance of an unscented Kalman filter is caused by the linearization process error between a real system and classical Kalman model. The unscented transformation can make a more accurate Kalman model. However, the complexity is its main drawback. This paper investigates the design and implementation of the proposed filter with Potter and Carlson square-root form. The proposed parallel reduced-order square-root unscented Kalman filter reduces memory and code size, and improves numerical computation. And the performance is not significantly different from the unscented Kalman filter. The experimentation is performed for the verification of the proposed filter.

A framework for capturing, statistically modeling and analyzing the evolution of software models

This paper presents a new methodological framework for capturing and statistically modeling the evolution of models in model-driven software development. The framework captures the changes between revisions of models in terms of both low-level (internal) and high-level (developer-visible) edit operations applied between revisions. In our approach, evolution is modeled statistically by using ARMA, GARCH and mixed ARMA-GARCH models. Forecasting and simulation aspects of these time series models are thoroughly assessed. The suitability of the framework is shown by applying it to a large set of design models of real Java systems. Our analysis shows that mixed ARMA-GARCH models are superior to ARMA models.A main motivation for, and application of, the resulting statistical models is to control the generation of realistic model histories which are intended to be used for testing model versioning tools. We present the architecture of the model generator and show how to generate random sequences from the statistical models which control the generation process. Further usages of the statistical models include various forecasting and simulation tasks.

Modeling and simulation of a controlled steam generator in the context of dynamic reliability using a Stochastic Hybrid Automaton

The paper proposes a modeling framework to support Monte Carlo simulations of the behavior of a complex industrial system. The aim is to analyze the system dependability in the presence of random events, described by any type of probability distributions. Continuous dynamic evolutions of physical parameters are taken into account by a system of differential equations. Dynamic reliability is chosen as theoretical framework. Based on finite state automata theory, the formal model is built by parallel composition of elementary sub-models using a bottom-up approach. Considerations of a stochastic nature lead to a model called the Stochastic Hybrid Automaton. The Scilab/Scicos open source environment is used for implementation. The case study is carried out on an example of a steam generator of a nuclear power plant. The behavior of the system is studied by exploring its trajectories. Possible system trajectories are analyzed both empirically, using the results of Monte Carlo simulations, and analytically, using the formal system model. The obtained results are show to be relevant. The Stochastic Hybrid Automaton appears to be a suitable tool to address the dynamic reliability problem and to model real systems of high complexity; the bottom-up design provides precision and coherency of the system model.

Exploring Nonspecific Protein Adsorption on Lignocellulosic Amphiphilic Bicomponent Films

In this contribution, we explore the interaction of lignocellulosics and proteins aiming at a better understanding of their synergistic role in natural systems. In particular, the manufacturing and characterization of amphiphilic bicomponent thin films composed of hydrophilic cellulose and a hydrophobic lignin ester in different ratios is presented which may act as a very simplified model for real systems. Besides detailed characterizations of the films and mechanisms to explain their formation, nonspecific protein adsorption using bovine serum albumin (BSA) onto the films was studied using a quartz crystal microbalance with dissipation (QCM-D). As it turns out, the rather low nonspecific protein adsorption of BSA on cellulose is further reduced when these hydrophobic lignins are incorporated into the films. The lignin ester acts in these blend films as sacrificial component, probably via an emulsification mechanism. Additionally, the amphiphilicity of the films may prevent the adsorption of BSA as well. Although there are some indications, it remains unclear whether any kind of protein interactions in such systems are of specific nature.

Identification of photovoltaic cell single diode discrete model parameters based on datasheet values

In this paper, photovoltaic cell single diode detailed model is developed and simulated. Entire system parameters in the model are taken into account. To determine the model parameters based on datasheet values and analyze the model, MATLAB system function (S-function) feature is preferred. S-function is used to obtain the photovoltaic cell discrete and applicable model in real system to be able to use in an embedded system. Necessary mathematical equations belong to the photovoltaic cell model are converted to discrete form and are written in S-function with C codes. Also, the simulation of the photovoltaic cell model is realized by using MATLAB S-function feature. To analyze and verify the validity of the presented model, I–V and P–V characteristic curves obtained from S-function are compared with datasheet characteristic curves of two commercial solar panels which are Kyocera KC200GT and Siemens SP75. The proposed model can be applied to any brand of photovoltaic panel by setting the parameters properly using datasheet values.

Classification and Contribution Analysis of Aromatic Clusters in Protein-Ligand Complexes

Intermolecular interactions are key features in the stabilization or destabilization of complexes. In particular, interactions involving aromatic rings have been extensively studied both theoretically and experimentally. Studies have shown that aromatic-aromatic interactions can be categorized by ring-ring orientation into a variety of different types, such as stacking interactions and T-shaped interactions. Because these different orientations affect stabilization, analyses of such interactions, for example ab initio molecular orbital calculations, are applied to pairs of aromatic rings, both in model systems and real systems. An important series of aromatic-aromatic interactions include those between pairs of aromatic residues in proteins. These residues have been studied computationally using both a theoretical chemistry approach and a knowledge-based analys. Protein 3D structural information is essential for knowledge-based studies of aromatic-aromatic interactions in protein-ligand complexes. Some databases filter entries from the Protein Data Bank (PDB) using criteria that make them suitable for computational approaches involving specific research targets. Lanzarotti et al. have shown that aromatic clusters in which three or more aromatic residues are in close proximity to each other are found in many protein structures, expanding pairwise aromatic-aromatic interactions. Moreover, these clusters are thought to be important in terms of protein function, structural stability and ligand recognition. Here, we show that aromatic clusters, as well as individual proteins, are found in a variety of protein-ligand complexes. As such, we anticipate that these clusters might have a significant role in ligand binding and could help in efficient ligand design.

Алгоритмизация эталонных моделей защищенности корпоративных автоматизированных систем на базе формальных моделей безопасности

The paper considers the process of algorithmization of reference security models implemented on the basis of the existing formal security models. Main approaches to practical implementation of reference security models in a key of identifying potential areas for improvement are studied. The paper describes the analysis of constraints of models for synthesis based on their formal reference model amenable to implementation in a software algorithm for subsequent practical security analysis of real systems. On the basis of a formalized model graph is built which combines multiple information security vulnerabilities and attack methods of realization of the consequences for the security systems on the basis of which controllable models of real systems can be created. An algorithm of the semi-automatic analysis of the security of corporate automated systems is developed.

Analysis of System Reliability with Control, Dependent Failures, and Arbitrary Repair Times

This work is motivated by modelling of real information systems. Parallel and series reliability models or their combinations are usually used for these tasks. Common assumptions for such models are independent failures, exponentially distributed failures and recoveries. These assumptions simplify a system modelling significantly, but often give a very rude approximation for it. So there are a lot of restrictions for an application of these models to practical tasks. This study presents a system with more general assumptions: dependent failures, arbitrary failures and repairs, and a system with control. We apply a continuous-time semi-Markov process to evaluate the reliability and the mean time to system failure (MTTF) for a system under these assumption. The repair time of each component is assumed to have an arbitrary distribution function (e.g., Weibull, Poisson or exponential). Kolmogorov equations method and the Laplace transform are used to derive generalised expressions for system state probabilities, reliability and MTTF. A numerical example is presented in order to illustrate the performance analysis of the model.

Computational complexity of finite asynchronous cellular automata

Cellular Automata (CA) are a well-established bio-inspired model of computation that has been successfully applied in several domains. In the recent years the importance of modelling real systems more accurately has sparkled a new interest in the study of asynchronous CA (ACA). When using an ACA for modelling real systems, it is important to determine the fidelity of the model, in particular with regards to the existence (or absence) of certain dynamical behaviors.This paper is concerned with two big classes of problems: reachability and preimage existence. For each class, both an existential and a universal version are considered. The following results are proved. Reachability is PSPACE-complete, its resource bounded version is NP-complete (existential form) or coNP-complete (universal form). The preimage problem is dimension sensitive in the sense that it is NL-complete (both existential and universal form) for one-dimensional ACA while it is NP-complete (existential version) or Π2P-complete (universal version) for higher dimension.

Application of Intelligent Technological Systems in Order to Increase Efficiency of the Lock Chamber System in Hydro Power Plants

The paper is a result of research at the Mechanical Engineering Faculty in Podgorica and represents the aspiration of authors to combine scientific and technical experience in order to achieve improvement in a real system. It is a complex system of lock chambers in a hydroelectric power plant. Based on a detailed analysis of the initial state, through the process modeling of complex real system, the authors identify possible areas where the intervening and applying modern systems with greater flexibility is necessary to achieve higher levels of automation. Also, proposed in the paper are measures for ensuring the security of information that rise system performance to a higher level compared to the competition and create an advantage in the global market.

Algebraic stability criteria of complex polynomials and their application in radio electronics

A new approach to validation of a number of algebraic stability criteria and theorems on localization of the roots of a complex polynomial in the complex plane is proposed. The solution is based on theorems relating complex polynomials and methods for the synthesis of reactive and quasi-reactive one-port networks. Analogs of the Routh tabular criterion and the Hermite–Hurwitz determinant criterion are considered, including critical cases. It is shown that the Routh algorithm is unsurpassed in simplicity and accuracy of calculations. Application of the criteria is illustrated by the analysis of the models of real dynamic systems, namely, two- and three-circuit oscillators with close eigenfrequencies.