System Modeling Method Research Articles

ОЦЕНКА УРОВНЯ ОБЕСПЕЧЕНИЯ УСТОЙЧИВОГО РАЗВИТИЯ ПРОМЫШЛЕННЫХ ПРЕДПРИЯТИЙ

The work is devoted to the issues of assessing the success of industrial enterprises from the standpoint of ensuring sustainable development. The analysis of approaches to the implementation of such assessments used in the scientific environment and in practice has been carried out, which made it possible to propose a classification of enterprises in terms of their ability to ensure sustainable development. Based on a systematic understanding of the concept of “sustainable development of an industrial enterprise”, the maturity matrix of the enterprise is formulated. The matrix includes indicators that determine the characteristics of the enterprise, such as resistance to external and internal negative impacts, development over a long period and readiness to switch to ESG principles. To form an approach to assessing sustainable development, such general scientific research methods as systematization and classification (including scientific ideas), analogy and generalization, induction and deduction, decomposition and aggregation, and methods of system modeling were used.

ПРОБЛЕМАТИКА ОБЕСПЕЧЕНИЯ УСТОЙЧИВОГО РАЗВИТИЯ ПРОМЫШЛЕННЫХ ПРЕДПРИЯТИЙ: КОНЦЕПТУАЛЬНОЕ ПРОСТРАНСТВО, МЕХАНИЗМЫ И СИСТЕМЫ УПРАВЛЕНИЯ

The article is devoted to the results of a study of industrial enterprises sustainable development discussed in scientific discourse and measures taken in practice to resolve the multifaceted issues behind these issues. Relying on the provisions and principles of the systemic paradigm in streamlining the issues of sustainable development of enterprises made it possible to identify sources of negative impact and classify them in the context of managers’ ability to control and influence various factors. On this basis and taking into account the specifics of industrial enterprises, in particular, the limitations of the applicability of the ESG concept to ensure the sustainable development of the enterprise are formulated, conditions for the progressive achievement of sustainable development are proposed. From the standpoint of management tasks, the actions of the manager and enterprise management mechanisms are proposed, which are essential for the development of intelligent management systems to ensure the sustainable development of the enterprise. The article also covers the issues of automation and intellectualization of enterprise management processes on strategic, tactical and operational circuits. To identify the factors of sustainable development and the mechanisms for achieving it, such general scientific research methods as systematization and classification (including scientific ideas), analogy and generalization, induction and deduction, decomposition and aggregation, and methods of system modeling were used.

Bispectral analysis and simulation modeling of quadratic nonlinear system with specific turbulent-fluctuation-excitation-response types

There exists a kind of quadratic nonlinear system with specific type of turbulent fluctuation excitation in nature, which belongs to a special non-Gaussian input signal system. Its characteristic is that the input signal spectrum is generated by turbulent fluctuations, and the power spectrum distribution of this turbulence fluctuation signal is close to Gaussian distribution. Starting with the work of Choi et al. (<ext-link ext-link-type="uri" xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://doi.org/10.1016/0022-460X(85)90370-0">1985 <i>J. Sound Vib</i><i>.</i> <b>99</b> 309</ext-link>) and Kim et al. [<ext-link ext-link-type="uri" xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://ieeexplore.ieee.org/document/1145286">1987 <i>IEEE J. Ocean. Eng.</i> <b>OE-12</b> 568</ext-link>), we extend the simulation of a specific turbulent fluctuation excited response-type quadratic nonlinear system represented by the wave excited mooring ship response, and fully develop the internal development of turbulence based on bispectral analysis technology. We also extend the simulation system and conduct systematic modeling analysis. The complete iterative method [<ext-link ext-link-type="uri" xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://doi.org/10.1088/1402-4896/ab725f">2020 <i>Phys. Scr.</i> <b>95</b> 055202</ext-link>] is used to solve the model, and calculate the linear transfer function and quadratic nonlinear transfer function. The comparison of simulation and modeling results with the real systems and their models confirms the correctness of the results from system simulation, system modeling, and model solving. The results obtained are all in line with expectations. The coherence analysis shows that the quadratic coherence of the random wave-ship swaying system is much greater than the linear coherence, but the linear coherence of the fully developed turbulence is greater for the near Gaussian input type. The reverse computation verification or comparison with real systems indicates that the turbulence simulation and system modeling method in this work have good accuracy and high efficiency in solving algorithms, and the research results can be effectively applied to the model description and system analysis of the quadratic nonlinear systems related to specific turbulent fluctuation excitation response.

Kelvin and Bush: Their Contributions to Today’s System Modelling and Simulation Methods

Kelvin and Bush: Their Contributions to Today’s System Modelling and Simulation Methods

Control of unstable water flow in open channels

The analysis and modeling of hydrodynamic processes in open channels are crucial for effective water resource management and hydraulic structure design. This study investigates unsteady water flow in main channels using the Saint-Venant equations. Analytical and numerical methods were employed to model various flow scenarios. The developed mathematical model effectively describes and analyzes flow characteristics such as discharge, free surface elevation, and flow velocity. The obtained results have practical applications in water resource management, flood forecasting, and infrastructure design for water conservation. Overall, this work contributes to the advancement of knowledge in open channel hydraulics and provides a basis for developing more accurate and reliable water system modeling methods. These equations allow for the simulation of hydrodynamic processes in rivers, channels, and reservoirs, enabling the prediction of water level fluctuations, flow velocities, and pressure distribution under various operating conditions. This plays a vital role in water resource management and the design of hydraulic structures.

Enhancing Privacy Preservation in Vehicular Trust Management Systems through Blockchain Technology

The advent of the Internet of Vehicles (IoV) has led to a significant surge in data generation from vehicles, prompting the innovative utilization of data transactions within the IoV environment. However, due to the inherent trustless nature of data transactions in IoV, concerns have arisen regarding the lack of trust between involved parties and the potential compromise of user privacy. To address these issues, blockchain technology emerges as a suitable decentralized distributed storage and security management solution, offering transparency and security in data transactions. In this study, we leverage blockchain to integrate with the IoV, devising a robust trust management framework, and devising a privacy protection scheme to safeguard user privacy concerns. Additionally, we employ the performance evaluation process algebra (PEPA) method for system modeling and performance analysis to assess the efficacy of our proposed solution. Empirical findings demonstrate that our approach effectively enhances the performance of data transactions within the IoV while ensuring that the privacy of users remains intact.

Shaking table tests and numerical simulations on RC frames retrofitted with friction-damped brace

In this study, the dynamic response of double-story reinforced concrete (RC) space frames retrofitted with diagonally arranged friction damped-brace system was evaluated through shaking table tests. A simplified friction damper was proposed and tested under cyclic loading, later used to retrofit an RC frame. The splice of a conventional steel brace was converted into a friction damper, which requires limited technical expertise on site. Commercially available brake-pads were used as a friction material between the splice plates and bracing elements. An artificial ground motion characterized by a short period, similar to the Korean earthquake histories, was generated and used for the shaking table tests. The tested RC frame half-scaled of existing old structures in Korea. The shaking table tests results demonstrated that the dynamic response of the retrofitted RC frame was improved with reduced drift demands. Additionally, a numerical modelling method for friction damped-brace system was developed, and the dynamic responses of retrofitted RC frame with the proposed friction damper was numerically investigated using OpenSees. The numerical simulation results agreed well with the experimental observations.

Slat Control Asymmetry Failure Simulation and Research

To construct the slats control system model and design asymmetry failure injection in the Slats control model, this paper provides an operation analysis of Slat system control and mechanical actuation in detail. The model of a slat control system based on Matlab or Simulink is established. Also, the method of slat asymmetry failure injection is designed, the root cause of slat asymmetry failure is listed, and left slat asymmetry failure is simulated via the designed model. The results demonstrated that the slats control system model and failure injection method can support the simulation of slat asymmetry failure and established the basis for subsequent research on the slats control system.

Compact Combustion Mechanisms of Typical n-Alkanes Developed by the Minimized Reaction Network Method

The existing combustion kinetic modeling method which aims at developing phenomenological combustion mechanisms characterized by multiple reactions confronts several challenges, including the conflicts between computing resources and mechanism scales during numerical simulation, etc. In order to address these issues, the minimized reaction network method for complex combustion system modeling based on the principle of simultaneous chemical equilibrium is proposed, which is aimed to develop combustion mechanisms with minimal reaction steps under a limited number of species. The concept of mechanism resolution is proposed in this method, and the reaction network with minimal reaction steps under a given mechanism resolution is constructed so that the scale of mechanisms is compressed greatly. Meanwhile, distinguishing from other mechanisms, the reversible form of elementary reactions is adopted and the classical two-parameter (A, Ea) Arrhenius equation fits the rate constants. Typical n-alkanes including n-butane, n-heptane, n-octane, n-decane, n-dodecane and n-hexadecane were taken as examples to indicate the development process of mechanisms and systematic kinetic validations were carried out. Results show that this method leads to very compact mechanisms with satisfactory accuracy, and it eliminates the process of mechanism reduction and is beneficial for mechanism optimization. This method and the derived kinetic mechanisms are hoped to contribute to combustion engineering applications.

Research on digital twin modeling and monitoring technology for smoke alarm calibration system

Aiming at the problems of backward calibration method of smoke alarm, low production efficiency and difficult real-time monitoring, a digital twin system modeling and monitoring method of smoke alarm calibration is proposed. First, through the analysis of smoke alarm calibration requirements, the overall framework design of the digital twin calibration system for smoke alarm is proposed, and then the twin model of smoke box is constructed by running the digital twin five-dimensional model. The physical smoke box, geometric model, physical model, rule model and behavior model are introduced in detail; Then the communication system architecture, data acquisition and data mapping are used to construct the twin data model; Finally, the feasibility was verified by the calibration system of an enterprise. Through the system, the qualified rate of smoke alarm calibration was increased from 98 to 99.6%, and the repair rate of defective products was reduced by 1.6%.

Orbit-attitude-structure coupled modelling method in local translational coordinate frame for multibody systems

The absolute coordinate-based (ACB) method, including absolute nodal coordinate formulation and natural coordinate formulation, is a widely-used dynamic modelling method for multibody systems. However, the problem of accuracy loss would arise when multi-scale motions are described in the same global coordinate system, such as large-scale orbital motions, small-scale attitude motions and structural vibrations, and micro-scale contact/collision. To address this problem, an ACB method in local translational coordinate system is proposed such that the large-scale orbital motions can be separated from other smaller-scale motions. The dynamic equations are derived by the Hamilton's equations and the Kronecker product. The validity of the proposed method is studied using an orbit-attitude coupled model of an orbiting rigid plate. It is found that the attitude errors of the original ACB method increase as time step size decreases. The reason for this counterintuitive phenomenon is that more serious accuracy loss is encountered for smaller time step size. In addition, more iterations are required for the original ACB method to obtain the prescribed tolerable error in each time step due to accuracy loss. In comparison, the proposed method is more accurate and efficient in numerical simulations. Finally, the proposed method is applied to the orbit-attitude-structure coupled simulation of a space robotic system.

Topology structure optimization of evolutionary hierarchical fuzzy systems

In this paper, a new method of hierarchical fuzzy system modeling for high-dimensional regression problems is proposed, which is called multi-objective evolutionary hierarchical fuzzy regression system (MOEHFRS). Different from the existing hierarchical fuzzy systems with fixed topology, the proposed MOEHFRS improves the accuracy of the model, reduces the total number of rules, and eliminates unnecessary features by flexibly constructing topology. In the process of topology evolution, MOEHFRS can exchange and combine different sub-fuzzy systems to achieve the selection and reuse of important features, as well as the elimination of unnecessary features, which improves the diversity of topology and enables the model to be well applied to high-dimensional regression problems. Different combinations of sub-fuzzy systems will result in different performance and number of rules. A new multi-objective evolutionary optimization algorithm is proposed to simultaneously optimize the number of rules and the accuracy of the model, which achieves the balance between complexity and accuracy of MOEHFRS. The proposed method is validated on 13 real world regression datasets and compared with other 5 methods. The results show that MOEHFRS is effective and advanced in terms of accuracy, number of rules, retention of important features and universality in different regression problems.

Causal Factors Analysis of runway excursion occurrences through Fuzzy Logic Modeling method

Runway excursion (RE) was one of main contributing factors to aviation occurrences whilst unstable approach precursors were the ones accounting for a significant proportion of those occurrences. The objective of this study is to identify the most influencing causal factors (hazards and risks) of RE occurrences and propose countermeasures to mitigate potential RE risks and RE occurrences in Taiwan. Causal Factors Analysis System and Fuzzy Logic Modeling method are used to classify hazards and risks of RE occurrences and establish a fuzzy logic model for RE occurrence predictions. The final squared multiple correlation coefficients (R2 = 0.9999) verify that the predictive capabilities of the final RE model are not affected after the exclusion of the less influencing parameters. Sensitivity analysis reveals that avoiding crosswind or tailwind landings can significantly reduce the likelihood of RE occurrences; and reducing inadequate supervision related errors is the most cost-effective strategy to mitigate probable RE risks. Local civil aviation authority and airline operators are all responsible to collaborate with each other to mitigate causal factors of RE occurrences due to inadequate supervision. Recommended countermeasures to the civil aviation authority: maintain sufficient depth of technical staff and appropriate deployment of management level personnel to conduct safety oversight; to airline operators: formulate non-punitive policy, clearly define and document go-around procedures, and develop evidence-based training for pilot monitoring's competencies needed including monitoring, call out and intervention to take control.

Frequency Stability Enhancement Using Differential-Evolution- and Genetic-Algorithm-Optimized Intelligent Controllers in Multiple Virtual Synchronous Machine Systems

In this paper, multiple virtual synchronous machines (VISMAs) with fuzzy proportional integral derivative (FPID) controllers optimized by differential evolution (DE) are proposed to maintain frequency stability in the grid in the presence of renewable penetration, such as wind and solar photovoltaic (PV) systems, residential loads, and industrial loads, by reducing the area control error in the objective function. Simulations are conducted using MATLAB/Simulink, and in the optimization process, the integral of the time-weighted absolute error (ITAE) is used as the objective function. In the work to obtain optimized values of renewable energy sources (RESs), fuzzy membership functions, controller gain parameters, and loads for system modeling, differential evolution and genetic algorithm (GA) methods are applied and the results were compared. It was shown that better results were achieved while FPID controllers were optimized by DE in the presence of multiple VISMAs than DE in the presence of single VISMAs and GA in multiple VISMAs. Moreover, the study is compared to integral control methods in which, compared to all controllers, the proposed controller reduces undershoot by 0.0674 Hz more than a single VISMAs, in which it is improved approximately by 97.82%. Similarly, the proposed controller improves the system settling time, rise time, and overshoot by more than 99.5% compared to the classical integral controller. To examine the robust operation of the system under the proposed controller, the system was run under a wide range of disturbances and uncertainties using random load perturbation of ± 20%, in which the proposed controller retains the system frequency by reducing or damping the system oscillation.

Effect of Aircraft Health Management on Aircraft Maintenance Program Development by Aircraft Manufacturer

The objective of the research is to propose a system modeling method for aircraft maintenance program development applying the condition-based maintenance using AHM (Aircraft Health Management) from the viewpoint of aircraft manufacturer. The proposed model based on the MSG-3 (Maintenance Steering Group - 3) considers the uncertainty of aircraft maintenance environment related to the airline operation and assumed system degradation levels. Then, the proposed model is formulated by using the concept of a robust optimization method.

A survey on the model-centered approaches to conceptual modeling of IoT systems

Internet of Things (IoT) is a system of connected objects, entities, devices, and components which share and transfer data over a network. Many papers are published on the topic of conceptual models in the IoT context, but it is difficult to assess the current status of the conceptual modeling approaches and methods for IoT systems. This paper presents an overview of the state of the art as well as discusses fundamental concepts, challenges and current research gaps with potential future agenda for conceptual modeling of IoT. Search facilities in the selected online repositories were used to identify the most relevant papers. The primary results were scanned and papers were selected according to the inclusion/exclusion criteria. Selected papers were assessed to extract data for the defined attributes. This paper confirms that there is a large body of research related to modeling of IoT systems. However, the results show that there is a lack of commonly agreed approaches and supporting formal methods for conceptual modeling of IoT systems. On the other hand, recent studies that apply model-based or model-driven development principles that use ontology or metamodel based approaches are promising due to systematic use of models as the primary means of a development process enabling for the dissemination of the methods further to the emerging fields such as smart cities, factories, transportation, hospitals, healthcare, hospitality and tourism, etc.

Rancang Bangun Aplikasi Pengelolaan Seminar Dan Webinar Berbasis Web Di Universitas XYZ


 The use of internet technology in the digital era has significantly impacted the execution of seminars, especially during the COVID-19 pandemic when social restrictions and large physical gatherings became challenging. The internet has become the primary solution to continue seminar activities. In this context, it allows seminar organizers to switch to online formats, utilizing video conferences and other digital platforms. However, a problem persists in the execution of seminars and webinars at XYZ University, as they still use manual methods in managing registrations, execution, and e-certificate publication for seminar participants. The aim of this research is to design and develop a Web-Based Seminar and Webinar Management Application, which is expected to assist seminar and webinar organizers at XYZ University in managing their events more easily and automatically. The application's development follows the Software Development Life Cycle (SDLC) methodology, employing Unified Modeling Language (UML) as the system modeling method. The research results demonstrate that the system developed is functionally capable of meeting the requirements for conducting seminars both online, offline, and hybrid seminars.

A review of uncertain factors and analytic methods in long-term energy system optimization models

A larger number of uncertain factors in energy systems influence their evolution. Owing to the complexity of energy system modeling, incorporating uncertainty analysis to energy system modeling is essential for future energy system planning and resource allocation. This study focusses on long-term energy system optimization model. The important uncertain parameters in the model are analyzed and divided into policy, economic, and technical factors. This study specifically addresses the challenges related to carbon emission reduction and energy transition. It involves collecting and organizing relevant research on uncertainty analysis of long-term energy systems. Various energy system uncertainty modeling methods and their applications from the literature are summarized in this review. Finally, important uncertainty factors and uncertainty modeling methods for long-term energy system modeling are discussed, and future research directions are proposed.

A multi-physics system integration and modeling method for piezoelectric wave energy harvester

The multiphysics system integration and modeling method, including hydrodynamic, kinematic, and electromechanical models, were developed. A one-way plucking-driven piezoelectric wave energy harvester (OPD-PWEH) was also developed; it consists of a floating cylindrical buoy, a frequency up-conversion mechanism based on a one-way bearing, and a piezoelectric component based on an array of piezoelectric bulk composite cantilever beams. The one-way bearing converts the repetitive clockwise and counterclockwise rotary motion of the input shaft into a single-directional clockwise rotary motion of the output shaft. The OPD-PWEH was tested in a wave flume under wave amplitudes of 50, 37.5, and 25 mm and wave periods of 1.0, 1.5, and 2.0 s. The experimental results showed that the RMS voltage and average power were 4.47 V and 0.4 mW, respectively, and they were obtained at 50 mm wave amplitude and 1 s wave period.

A novel transfer matrix-based method for steady-state modeling and analysis of thermal systems

Performance analysis and optimization of thermal systems are unprecedentedly crucial in pursuing higher energy efficiency. However, the precise modeling and high-efficiency calculation of modern, complex thermal systems are still challenging. Here we present a transfer matrix-based system modeling method to tackle these challenges. The transfer matrix of heat exchangers is defined to describe the temperature mapping relation between inlet and outlet nodes. Heat-work conversion devices are described by the working fluid temperature variation. The system modeling follows a three-step procedure: (1) building system transfer matrix by aggregating component models; (2) separate given and unknown node temperatures by removing redundant rows and columns in the system transfer matrix; (3) rearrange the reduced system transfer matrix to calculate internal and outlet node temperatures. The constructed system model does not introduce unnecessary simplifications and describes the system’s nonlinearity accurately. The proposed modeling method is first presented and validated on a parallel-series and a multi-loop heat exchanger network. Numerical results with both constant and varying fluid properties confirm the method’s validity. Case studies on three thermodynamic systems further validate the method’s capability and efficiency. The proposed method is finally compared with conventional modeling methods and heat current method to highlight its features and advantages.