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This research introduces the NeuRaiSya (Neural Railway System Application), an innovative railway signaling system integrating deep learning for passenger analysis. The objectives of this research are to simulate the NeuRaiSya and evaluate its effectiveness using the GreatSPN tool (graphical editor for Petri nets). GreatSPN facilitates evaluations of system behavior, ensuring safety and efficiency. Five models were designed and simulated using the Petri nets model, including the Dynamics of Train Departure model, Train Operations with Passenger Counting model, Timestamp Data Collection model, Train Speed and Location model, and Train Related-Issues model. Through simulations and modeling using Petri nets, the study demonstrates the feasibility of the proposed NeuRaiSya system. The results highlight its potential in enhancing railway operations, ensuring passenger safety, and maintaining service quality amidst the evolving railway landscape in the Philippines. [ABSTRACT FROM AUTHOR]

The Cucumber Productivity Simulation Model (CPSM) was developed to precisely predict the dynamic process of cucumber productivity in a solar greenhouse. This research conducted a variety of sowing experiments and collected data on cucumber productivity and meteorological conditions from 2013 to 2015 and 2018 to 2020. Employing the principles of least squares, the relationship between cucumber productivity indicators and effective accumulated temperature (EAT) was fitted, determining key crop parameters and constructing the CPSM. Validation of the model was conducted using independent experimental data, evaluating its simulation accuracy. The results indicate that (1) CPSM can dynamically and meticulously simulate the formation process of different productivity indicators in cucumber. Normalized root mean square errors (NRMSE) ranged from 0.44% to 19.64%, and mean relative errors (MRE) ranged from 0.31% to 17.23% across different productivity indicator models. The models for organ water content, maximum root length, specific leaf area, and organ fresh weight distribution index demonstrated high simulation accuracy, while others showed relatively high accuracy. (2) Simulation accuracy varied with indicators and varieties. 19 indicators (34.55%) exhibited high simulation accuracy and 30 indicators (54.55%) showed relatively high accuracy. The JY35 variety (10.44 ± 8.49%) outperformed the JS206 variety (13.44 ± 8.50%) in terms of simulation accuracy. The JY35 variety had 39 superior productivity indicators (70.91%) while the JS206 variety had sixteen (29.09%). CPSM utilizes easily accessible temperature data as its input, allowing for precise and detailed simulation of productivity indicators for cucumber production in solar greenhouses. This research lays a theoretical foundation and provides technical support for guiding intelligent production management, efficient utilization of agricultural resources, and climate change productivity assessment in solar greenhouse cucumber production. [ABSTRACT FROM AUTHOR]

This study developed a finite element method (FEM) dynamic simulation to visualize the deployment behavior of thin membrane structures in the space environment. The proliferation of space debris resulting from accelerated space development threatens the future of space. Numerous researchers have explored strategies to prevent artificial structures from remaining in space and becoming space debris. One such method involves utilizing a drag sail device to de-orbit artificial structures, which reduces their kinetic energy by inducing additional atmospheric drag, allowing them to re-enter the Earth's atmosphere. Tohoku University and Nakashimada Engineering Works, Ltd. have successfully developed a deployable membrane structure for de-orbit purposes and demonstrated its effectiveness in space. Space structures, such as membranes, exhibit highly nonlinear behavior due to their flexible properties, and ground tests by actual devices cannot fully demonstrate their deployment stability in a microgravity environment. Therefore, evaluating the deployment behavior using simulation methods instead of relying solely on hardware development is crucial. In this study, we employed FEM to establish a simulation environment, which enables us to consider nonlinear oscillations of flexible structures, such as the membrane. The simulation results closely reproduce the deployment motion observed in ground tests by appropriately incorporating constraint conditions related to deployment forces and hardware interactions, such as a hub component initially wrapped by the membrane. The simulation facilitated an assessment of the impact of membrane properties on deployment without the need for physically developing an actual hardware device. We proposed evaluation methods for determining membrane properties in terms of the trend of propagation of deployed surface area and the tendency of deployment motion. This established simulation technique can be utilized to develop future flexible space structures. • De-orbit Membrane Mechanism (DOM) was developed as a satellite de-orbit application. • Formulate nonlinear FEM analysis of non-spin type deployable structures. • Modeling techniques of the membrane in simulation. • Evaluation of the membrane deployment between simulation and ground experiments. • Proposed methods can be used to predict the deployment behavior of the actual membrane. [ABSTRACT FROM AUTHOR]

The launcher recovery method known as 'In-Air Capturing' is an innovative approach where a winged rocket stage is captured mid-air by an aircraft and subsequently towed back to the launch site. To achieve this, a capturing device attached to a tether is released from the towing aircraft. This device autonomously connects the reusable launch vehicle to the aircraft, while the two vehicles are in proximity. The tether's flexible dynamics have a strong influence on the maneuverability of the capturing device. Thus, it is critical to model the dynamics of the tether to get a realistic understanding and to evaluate feasibility of the concept. However, precise modelling and control of highly flexible systems with large deformations is both challenging and computationally intensive. For engineering applications which involve closed-loop simulations, finding a trade-off between accuracy and computational effort is crucial. In this paper, the tether is modelled as a discretized chain of rigid bodies connected by rotational springs at the joints. The tether along with the capture system is integrated in a simulation model and open loop tests are performed to analyse the system characteristics. The tether properties are studied to find a suited configuration for 'In-Air Capturing'. • Multibody modelling approach for long cable like bodies with large deformation. • Capture system dynamics for the unique 'In-Air Capturing' launcher recovery concept. • Dynamic modelling for the complete capturing system including towing aircraft, capturing device and tether. • Assessment of tether properties suited for 'In-Air Capturing' with sensitivity studies. [ABSTRACT FROM AUTHOR]

Nonlinear dynamics plays a crucial role particularly in equipment validation of preparation production, validation results of which will significantly influence the results and period of drug registration in drug production processes. In this research, the flow field and temperature field simulation, calculation and analysis are creatively carried out in terms of depyrogenation tunnel, a very popular preparation drying-sterilization equipment in pharmaceutical processes with strong dynamic characteristics. After construction of 3D model of this equipment using Catia and mesh generation applying ANSYS, the computational fluid dynamic (CFD) method and verification of irrelevance method are carried out regarding 6.05 million of meshes to identify the flow velocity model and heat transfer model inside the equipment, to further provide methodology for pharmaceutical process validation and to further optimize the design of control methods. After calculation and simulation, the low-velocity vortices of different sizes inside the hood and the drying chamber are identified, which could cause vials to fall down; meanwhile, vials that are farther away from the outlet receives less heat exchange effect, which would shrink the effective sterilization area, indicating an inadequate validation methodology in pharmaceutical processes. [ABSTRACT FROM AUTHOR]

The establishment of a high-fidelity simulation model for heating systems is crucial for practical guidance, as it serves predictive and evaluative purposes, offering accurate references for the operational management of actual engineering projects, thereby minimizing resource and cost wastage. This study, utilizing the Transient System Simulation Program (TRNSYS) software and focusing on an electric boiler water storage heating system in an elementary school, has developed a high-fidelity simulation model. Multiple TRNSYS (Types) modules were independently programmed, and the model's stability and precision were verified through error analysis. The model is capable of dynamically simulating the changes in supply and return water temperatures on both the storage and usage sides of the system under varying external environmental conditions and hydraulic states, achieving synchronous computation of the thermal and hydraulic characteristics of the heating system. The comparison and analysis of the temperature measurements at various system points against actual collected data revealed an average relative error of less than 5% across these measurements, indicating the simulation model's high accuracy and operational stability. It accurately and reliably reflects the thermal dynamics of the heating system, providing a reliable reference for practical application. This model is applicable for guiding the operational management of actual engineering projects and offers a scientific basis for subsequent system design and optimization. [ABSTRACT FROM AUTHOR]

With the penetration of distributed resources into power distribution networks, power distribution networks are transforming into active distribution networks with a high proportion of distributed generations and power electronic equipment. Efficient modeling and simulation methods are essential to perform dynamic response analysis. In order to satisfy the fast/steady/slow multiple time-scale simulation requirements of active distribution networks, a fast/medium/slow time partition model and a network decoupling method for short line characteristic lines is proposed in this paper. Through the decomposition coordination simulation method, the network is decomposed into multiple regions that can be simulated in parallel. Based on the interconnection of fiber optic network cards, a multi-rate parallel simulation and synchronization strategy is proposed, which significantly improves the simulation speed of active distribution networks while ensuring simulation accuracy. The numerical experiments have been conducted based on a modified IEEE 33-bus and a PG&E 69-bus, and simulation results show the feasibility of the proposed method. The verification results of the example show that using adaptive variable-step-size multi-rate parallel simulation technology can increase the subnet computation-time balance rate and simulation acceleration ratio to 119.90% and 121.31% in the same rate-parallel mode. [ABSTRACT FROM AUTHOR]

E-scooter vibrations are a problem recently studied. Theoretical models based on dynamic simulations and also real measurements have confirmed the high impact of e-scooter vibrations on driver comfort and health. Some authors recommend improving e-scooter damping systems, including tyres. However, it has not been suggested nor has any research been published studying how to improve e-scooter frame design for reducing driver vibrations and improving comfort. In this paper, we have modelled a real e-scooter to have a reference. Then, we have developed a multibody dynamic model for running dynamic simulations studying the influence of mass geometry parameters of the e-scooter frame (mass, centre of gravity and inertia moment). Acceleration results have been analysed based on the UNE-2631 standard for obtaining comfort values. Based on results, a qualitative e-scooter frame design guide for mitigating vibrations and increasing the comfort of e-scooter driver has been developed. Some application cases have been running on the multibody dynamic simulation model, finding improvements of comfort levels higher than 9% in comparison with the e-scooter reference model. The dynamic model has been qualitatively validated from real measurements. In addition, a basic sensor proposal and comfort colour scale is proposed for giving feedback to e-scooter drivers. [ABSTRACT FROM AUTHOR]

This paper aims to present two approaches for repeated-pole plus dead-time (RPPDT) models identification procedures for highorder processes based. First approach is based on using two or three points over the process reaction curve −an open-loop test− whereas the second approach is based on the use of the process relay control oscillating signals −a closed-loop test. Equations are provided for both model parameters identification as well as order estimation. Comparison tests confirm that the RPPDT models provide a better representation of the high-order process dynamics than its simple, usually employed, first-order approximation. These models are suitable for process representation in dynamic simulations and control system design studies. [ABSTRACT FROM AUTHOR]

There are two approaches for simulating memory as well as learning in artificial intelligence; the functionalistic approach and the cognitive approach. The necessary condition to put the second approach into account is to provide a model of brain activity that contains a quite good congruence with observational facts such as mistakes and forgotten experiences. Given that human memory has a solid core that includes the components of our identity, our family and our hometown, the major and determinative events of our lives, and the countless repeated and accepted facts of our culture, the more we go to the peripheral spots the data becomes flimsier and more easily exposed to oblivion. It was essential to propose a model in which the topographical differences are quite distinguishable. In our proposed model, we have translated this topographical situation into quantities, which are attributed to the nodes. The result is an edge-weighted graph with massbased values on the nodes which demonstrates the importance of each atomic proposition, as a truth, for an intelligent being. Furthermore, it dynamically develops and modifies, and in successive phases, it changes the mass of the nodes and weight of the edges depending on gathered inputs from the environment. [ABSTRACT FROM AUTHOR]

In order to improve the accuracy and credibility of the dynamic simulation model of the coordination mechanism, a general simulation model validation and updating framework was proposed. First, the dynamic model of the coordination mechanism was established considering two friction models. Then, in order to validate the accuracy of the simulation model, for the high-dimensional uncertainty, a validation method of the coordination simulation model based on principal component analysis-area index was proposed. Aiming at the problem that the simulation model was unreliable, a simulation model updating method based on parameter identification was proposed. Finally, the correctness and effectiveness of the method were verified, and the result showed that the accuracy of the simulation updating model with identified LuGre friction model was improved by 31.03 % than the one with identified Coulomb friction model. Thus, the accuracy and credibility of the coordination mechanism simulation model were greatly improved. It provides a theoretical support for the simulation model validation & updating of the coordination mechanism and other mechanical mechanisms. [ABSTRACT FROM AUTHOR]

Artificial neural networks have changed many fields by giving scientists a strong way to model complex phenomena. They are also becoming increasingly useful for solving various difficult scientific problems. Still, people keep trying to find faster and more accurate ways to simulate dynamic systems. This research explores the transformative capabilities of physics-informed neural networks, a specialized subset of artificial neural networks, in modeling complex dynamical systems with enhanced speed and accuracy. These networks incorporate known physical laws into the learning process, ensuring predictions remain consistent with fundamental principles, which is crucial when dealing with scientific phenomena. This study focuses on optimizing the application of this specialized network for simultaneous system dynamics simulations and learning time-varying parameters, particularly when the number of unknowns in the system matches the number of undetermined parameters. Additionally, we explore scenarios with a mismatch between parameters and equations, optimizing network architecture to enhance convergence speed, computational efficiency, and accuracy in learning the time-varying parameter. Our approach enhances the algorithm's performance and accuracy, ensuring optimal use of computational resources and yielding more precise results. Extensive experiments are conducted on four different dynamical systems: first-order irreversible chain reactions, biomass transfer, the Brusselsator model, and the Lotka-Volterra model, using synthetically generated data to validate our approach. Additionally, we apply our method to the susceptible-infected-recovered model, utilizing real-world COVID-19 data to learn the time-varying parameters of the pandemic's spread. A comprehensive comparison between the performance of our approach and fully connected deep neural networks is presented, evaluating both accuracy and computational efficiency in parameter identification and system dynamics capture. The results demonstrate that the physics-informed neural networks outperform fully connected deep neural networks in performance, especially with increased network depth, making them ideal for real-time complex system modeling. This underscores the physics-informed neural network's effectiveness in scientific modeling in scenarios with balanced unknowns and parameters. Furthermore, it provides a fast, accurate, and efficient alternative for analyzing dynamic systems. [ABSTRACT FROM AUTHOR]

This work introduces a new permutation-symmetry-adapted machine learning diabatization procedure, termed the diabatization by equivariant neural network (DENN). In this approach, the permutation symmetric and anti-symmetric elements in diabatic potential energy metrics (DPEMs) were simultaneously simulated by the equivariant neural network. The diabatization by deep neural network scheme was adopted for machine learning diabatization, and non-zero diabatic coupling was included to increase accuracy in the near degenerate region. Based on DENN, the global DPEMs for 11A′ and 21A′ states of MgH2 have been constructed. To the best of our knowledge, these are the first global DPEMs for the MgH2 system. The root-mean-square-errors (RMSEs) for diagonal elements (H11 and H22) and the off-diagonal element (H12) around the conical intersection region were 5.824, 5.307, and 5.796 meV, respectively. The RMSEs of global adiabatic energies for two adiabatic states were 4.613 and 12.755 meV, respectively. The spectroscopic calculations of the 11A′ state in the linear HMgH region are in good agreement with the experiment and previous theoretical results. The differences between calculated frequencies and corresponding experiment values are 1.38 and 1.08 cm−1 for anti-symmetric stretching fundamental vibrational frequency and first overtone. The global DPEMs obtained in this work should be useful for further quantum mechanics dynamic simulations on the MgH2 system. [ABSTRACT FROM AUTHOR]

The South African mining sector depends on intensive energy usage to extract minerals. Most of this energy is used to enhance underground working conditions through cooling. Electricity costs have been on the rise, reducing the profitability of mines. Mines must invest in management systems that optimise energy usage while maintaining underground conditions. Dynamic simulation models are critical for systems analysis, optimal management, and improved decision-making. This paper presents an integrated dynamic simulation model for deeplevel mine cooling systems. The model was developed using Process ToolBox simulation software, and a Mean Average Percentage Error of 3.53% was achieved. The impact of load curtailment on underground services was simulated. Eight working areas exceeded the legal limit of 32.5 °C, and the steady state simulation underestimated the impact, as only three working areas were affected. The simulation was sensitive to the ambient conditions; high temperatures were noted in the working areas when the ambient temperatures peaked. [ABSTRACT FROM AUTHOR]

In order to reduce global energy consumption, energy-efficient, green and smart buildings should be built. In addition to the application of other energy efficiency measures, effective management of heating, ventilation and air conditioning (HVAC) systems are also required. High-quality management and control of those systems ensures optimal occupant comfort, proper operation, rational energy consumption, and a positive impact on the environment. This is especially important for large buildings with complex systems such as hotels. As a contribution to the creation of appropriate tools for the management and control of HVAC systems in smart buildings, this paper presents the results of the development of a detailed dynamic simulation model based on data collected from a smart room system in a hotel in Zagreb, Croatia. The smart room system provides historical data on a set and actual room temperatures, occupancy schedule, windows openings, fan coil unit (FCU) operating status, fan speed, control valve opening, and heating or cooling modes with a time step of 5 minutes. The simulation model based on TRNSYS software uses part of the available data and predicts the room temperatures. A comparison of the predicted and measured temperatures at each time step shows that the deviations of the manually calibrated model are within acceptable standardized limits. The developed model has been applied to identify major anomalies in the operation of the FCU system, yielding promising results. [ABSTRACT FROM AUTHOR]

This paper proposes the modeling and simulation of a novel dynamic control strategy for 2.4 kWp single-phase grid-connected photovoltaic systems under real outdoor weather conditions using an intelligent Fuzzy–PI MPPT controller. The PV array in the first case is fixed and tilted at a 32° angle, whereas the PV array in the second is equipped with dual-axis sun tracking. The objective is to deliver the maximum power from the PV array and to improve the drawbacks of the classical MPPT control. The optimization is performed using a real-time daily profile of Ghardaia, Algeria (32.24°N – 3.24°W). The proposed MPPT controller (Fuzzy PI MPPT) is optimized under different climatic scenarios based on four selected typical days: the first two days in winter and the second two days in summer. An analysis of the performance and simulation of a photovoltaic conversion system associated with a solar tracker, comparing it from an energy point of view with a fixed photovoltaic converter, has been carried out in Matlab/Simulink software. The results show that grid-connected PV with dual solar tracking enhances the PV array output power efficiency by about 25% compared to a similar fixed PV system. The results show that higher injected power quality is achieved and the overall system has higher efficiency. [ABSTRACT FROM AUTHOR]

Complex vibrational phenomena, such as gear impacts and mesh stiffness excitations, often require a significant amount of effort to be revealed using nonlinear analytical methods. However, key parameters for addressing vibrational problems can often be identified through simplified approaches based on linear analysis models. In light of these considerations, this study aimed to propose linear analytical methods to investigate the influences of various key parameters within symmetric systems. To achieve the main goal of this study, system modeling and eigensolutions were first implemented, focusing on a specific manual transmission with a front-engine/front-wheel configuration. Second, analytical techniques to reduce the number of degrees of freedom from the original symmetric system were suggested, and the reduced model was validated. Third, the system responses in the time domain were examined, along with key system parameters, such as gear mesh stiffness and clutch dampers, using state–variable equations. As a result, the findings from the linear system model demonstrated the fundamental dynamic characteristics of the torsional system within specific frequency regimes relevant to noise and vibration problems. Furthermore, the reduced lumped linear model employing the state–variable formula established its reliability in determining key parameters for mitigating noise and vibration problems. [ABSTRACT FROM AUTHOR]

This document is a summary of a special issue of the journal Mathematics, titled "Mathematical Modeling and Simulation in Mechanics and Dynamic Systems, 2nd Edition." The special issue focuses on the development of sophisticated models to predict phenomena in dynamic systems using experiments and computer models. The issue includes papers on topics such as modeling mechanical systems, new methods in dynamic systems, and the behavior simulation of mechanical systems. The papers were written by authors from 13 different countries, and the majority of the articles adhere well to the theme of the special issue. The document also provides a table showing the geographic distribution of authors by country. The authors of the special issue have made significant contributions to the field, and the document concludes by stating that the authors have no conflicts of interest. [Extracted from the article]

Through flexible configuration of warship formation, the Aegis Warship Formation achieves interception and defense of targets in different attack directions. Based on the warship coordinate system and target coordinate system, the detection and interception zone models of Aegis warship formation are constructed. The functional simulation models of guidance radar and SM-3 interceptor are integrated to propose a dynamic simulation modeling method for anti-missile defense of warship formations. The detection directional coefficient and killing directional coefficient are defined, which are used to quantitatively evaluate the directional characteristics of the formation anti-missile defense. The simulations are conducted with a typical case of two-ship Aegis formation, and useful conclusions are obtained. The results can provide support for battlefield offensive and defensive situation assessment. [ABSTRACT FROM AUTHOR]

The Electric Power Steering (EPS), as an advanced vehicle steering technology, is widely used in present-day society. The EPS provides great convenience for vehicle driving. More and more vehicles are starting to equip this technical configuration. For testing the performance of the EPS in the laboratory, the study independently develops an EPS test bench for dynamic simulation of vehicle EPS steering load. The EPS test bench detects in the mode of the whole vehicle in the loop. During the test, the vehicle is placed on a fixed platform of the EPS test bench and connected to the tensile component for testing. The EPS test bench provides dynamic simulation of vehicle steering load in a pneumatic way. And the load simulation system of the EPS test bench is simulated. The simulation test shows the feasibility of the EPS test bench. The EPS test bench is tested through the joint real vehicle. The test results shows that the experimental value and the theoretical value are within the error range. And the test results also shows that the EPS test bench is accurate. The EPS test bench provides valuable text for the future development of the EPS load simulation research. Moreover, the study points out the development trend of the EPS test bench. [ABSTRACT FROM AUTHOR]

A simplified theoretical model of the AERORail vehicle-bridge coupling system and a corresponding numerical simulation system in Simulink are established. Based on several widely used methods for modelling and simplifying vehicle systems, the Simulink simulation system used in this study, including the vehicle system and the bridge (AERORail) system, is presented. Identification examples using a moving load model and a simplified 1/4-scale vehicle model are established. The simulation results agree with the data of the simplified dynamic model, with errors between 2.9% and 4.72%, and a satisfactory accuracy is achieved even for single-point signal identification, thereby verifying the correctness of the simplified dynamic model of the AERORail system and the improved time-domain method based on the method of moments. [ABSTRACT FROM AUTHOR]

The transformation of manufacturing industry to green manufacturing is one of the important tasks to achieve the carbon peaking and carbon neutrality goals, which needs to improve the use efficiency of unit carbon emission. In order to describe the processing state in real time and improve the accuracy of carbon emission prediction, a dynamic prediction and simulation model of carbon efficiency based on digital twin was proposed. First, the dynamic characteristics of carbon emission during hobbing process was analyzed, and three carbon efficiency targets were defined to assess carbon emissions from processing processes. Then, a dynamic prediction and simulation model of carbon emissions was constructed based on convolutional neural network and dynamic discrete event system specification. On this basis, the framework of the carbon efficiency digital twin (CEDT) of the hobbing process was built, and the dynamic prediction and simulation models were integrated into CEDT as virtual models. The application in hobbing process showed that the presented model has higher accuracy in carbon emission prediction. The root-mean-square error, mean absolute error, and mean absolute percentage error of the real-time power prediction were reduced by 43.98%, 34.55%, and 30.67% on average, compared with the traditional method. Meanwhile, the validity of CEDT was verified and the effect of dynamic parameters on carbon efficiency was discussed. [ABSTRACT FROM AUTHOR]

A comprehensive three-dimensional dynamic model of a multi-cable double-drum winding hoister with flexible guides is presented, as the existing models cannot deal with the three-dimensional eccentricity of the cage and out-of-plane excitation generated by rotational drums. The entire system consists of three subsystems: cable subsystem, cage subsystem, and guide subsystem, respectively. Displacement and force boundary conditions are employed to couple those subsystems, and the interaction between cage and guides is considered as bidirectional coupling. The dynamic models of the three subsystems are established by Hamilton principle and Newton-Euler equation in a three-dimensional space independently. The dynamic model is discretized and solved by the Galerkin method and Runge-Kutta method. The three-dimensional displacement excitations and three-dimensional eccentricity can be handled in this dynamic model. The differences between two-dimensional dynamic model and three-dimensional dynamic model are discussed and the mechanism of entire system vibration are also analyzed by numerical simulation with typical unbalance factors, the cage eccentricity. The results show that the proposed three-dimensional dynamic model is more accurate in some realistic cases, existing out-of-plane excitation or three-dimensional eccentricity of the cage. [ABSTRACT FROM AUTHOR]

Calibration of the existing building simulation model is key to correctly evaluating the energy savings that are achievable through retrofit. However, calibration is a non-standard phase where different approaches can possibly lead to different models. In this study, an existing residential building is simulated in parallel by four research groups with different dynamic simulation tools. Manual/automatic methodologies and basic/detailed measurement data sets are used. The calibration is followed by a validation on two evaluation periods. Monitoring data concerning the windows opening by the occupants are used to analyze the calibration outcomes. It is found that for a good calibration of a model of a well-insulated building, the absence of data regarding the users' behavior is more critical than uncertainty on the envelope properties. The automatic approach is more effective in managing the model complexity and reaching a better performing calibration, as the RMSE relative to indoor temperature reaches 0.3 °C compared to 0.4–0.5 °C. Yet, a calibrated model's performance is often poor outside the calibration period (RMSE increases up to 10.8 times), and thus, the validation is crucial to discriminate among multiple solutions and to refine them, by improving the users' behavior modeling. [ABSTRACT FROM AUTHOR]

The research of multiple inspection robots' path simulation planning helps to improve the inspection ability and efficiency of the multi-robot system. This paper studies the problem of cooperative optimization and simulation of multiple robots for multiple inspections in intelligent manufacturing. A dynamic simulation model of the inspection robot is used to construct the state equation of the multirobot inspection simulation system. The square grid is used to decompose the intelligent manufacturing workshop area and simulate the workshop space. With reinforcement learning, a multi-robot patrol simulation system is created for full coverage path simulation planning. The results show the effectiveness of the system for cooperative optimization control and reasonable path planning. [ABSTRACT FROM AUTHOR]

This paper compares different track model formulations for the simulation of dynamic vehicle–track interaction in switches and crossings (S&C, turnouts) in a multi-body simulation (MBS) environment. The investigations are an extension of the S&C simulation Benchmark with the addition of a finite element model of a 60E1-760-1:15 turnout. This model constitutes a common reference from which four different track formulations are derived: co-running, modal superposition, finite element incorporated into the MBS model and finite element coupled to MBS using a co-simulation approach. For the different track models, the difference in modelling technique, results, simulation time, and suitability for different simulation tasks is compared. A good agreement is found between the different track model formulations for wheel–rail contact forces and rail displacements. This study found a better agreement between co-running and structural track models compared to previous studies in the prediction of wheel–rail contact forces. This appears to be due to the increased complexity of co-running track model used in this study together with a tuning of the co-running track model to the reference model in a wider frequency range. For the reader interested to reproduce the results in this paper, the reference track model is available for download. [ABSTRACT FROM AUTHOR]

This paper presents the final description for the S&C Benchmark that was launched at the IAVSD 2019 conference held in Gothenburg, Sweden and completed by eighteen participants by the end of 2020. The purpose of this paper is to allow for the replication of the Benchmark exercise after publication for those who wish to do so in the future, and it includes a link to the repository containing all necessary input data. The original task description, including a description of the Benchmark submission, is presented in full. The results from the Benchmark are available in [Bezin Y, Pålsson BA, Kik W, et al. Multibody simulation Benchmark for dynamic vehicle-track interaction in switches and crossings: results and method statements. Submitted to VSD, 2021]. [ABSTRACT FROM AUTHOR]

• A dynamic model of civil aircraft air-cycle refrigeration system was developed • A dynamic solution method was introduced for dynamic mass transfer solution. • A near-logarithm heat transfer temperature difference function is presented. • A pressure-flow decoupling method is presented to obtain ACM pressure parameters. Dynamic simulation model of air-cycle refrigeration system s in civil aircrafts is essential for revealing the operation mechanism during flight process. In the present study, a dynamic model of three-wheel air-cycle refrigeration system was developed. A near-logarithm heat transfer temperature difference function is utilized to improve the stability of the heat transfer solution. A dynamic solution method based on continuity equation and theorem of momentum was presented as the framework of the dynamic mass transfer solution. A pressure-flow decoupling method is presented to solve the dynamic pressure in the high-pressure zone, resolving the absence of key pressure parameters. The model has been validated based on experimental data, with a pack discharge temperature deviation of 0.05K. Dynamic simulations have been conducted with actual flight data to obtain transient performance under airborne condition. In the takeoff and landing phase, the drastic change in the environment results in low discharge temperature, endangering the condenser with icing risk, which can be avoided by enabling the TCV. In the cruise phase, the discharge temperature slightly exceeds the upper limit for a couple of minutes. The optimization by slightly extending the length of heat exchanger channels succeeded in eliminating the excessive discharge temperature with minimal side effects. [ABSTRACT FROM AUTHOR]

This work proposes a comprehensive numerical dynamic model of a flexible-rotor bearing system based on the Hertzian and cubic polynomial nonlinear contact force methods. The model can consider the influences of the nonlinear bearing contact forces and unbalanced force caused by the rotor offset. The displacements and spectrums of the flexible-rotor bearing system from the Hertzian and cubic polynomial nonlinear contact force methods are discussed. The influences of the radial clearance, eccentricity, mass, and deformation of the rotor on the frequency–amplitude characteristics of the flexible-rotor bearing system considering a large speed range are analyzed. The results show that the dynamic and vibration characteristics of the flexible-rotor bearing system from the Hertzian and cubic polynomial nonlinear contact force methods are different. The differences of the frequency–amplitude characteristics between the flexible- and rigid-rotor bearing system are small in a lower speed stage; however, their differences are very large in a higher speed stage. This method can be applied to the nonlinear dynamic modeling and simulation of the flexible-rotor bearing system, which can predict the dynamics and prevent the system failures during the design processing of rotor system. [ABSTRACT FROM AUTHOR]

Emergency materials transportation, both economic and societal, is one of the most important parts of unconventional emergency management. In the present study, we built a quantitative simulation model underlying the mechanism of emergency materials transportation specifically regarding typhoon disasters. We then explored the internal influence factors and association mechanisms of the dynamic model as they relate to the effective control and guidance of emergency materials transportation. Using system dynamic model, this paper conducts the simulation study to identify the key influencing factors for the speed of emergency materials transportation. The relationships between influencing factors and the emergency capability were analyzed qualitatively. On this basis, SD flow chart was built. A typhoon disaster event in Leizhou Peninsula, China, is used as an example to validate the effectiveness and feasibility of the proposed model, as well as to simulate different emergency management strategies. Results of governmental emergency materials transportation are key factors in process of emergency formulating the policy to improve the speed and efficiency for emergency materials transportation during the emergency management process. [ABSTRACT FROM AUTHOR]

In recent years, large-scale testing has begun for connected and autonomous driving, making it possible to implement the concept of Dynamic Lane Reversal (DLR), which can quickly shift lane directions to reflect instantaneous flow dynamics. DLR is to make full use of road space and avoid waste of road capacity, and potentially alleviate congestion. However, the impact and feasibility of DLR remain unclear. In order to investigate the effectiveness, the feasibility, and the applicability of DLR, we utilize a direction-changeable, lane-based cell transmission model to find an optimal DLR scheme for a roadway segment with stochastic traffic flow in both directions. A proxy model is also designed to realize DLR in VISSIM. A regression analysis was carried out to find the impacts of directional flow rate and the number of lanes on delay reductions due to DLR. Results indicate that implementing DLR can reduce the total queuing delay considerably compared to traditional reversible lane strategies. We found that DLR achieved superior performance on segments with more lanes and when the flows from each direction were close to one another. A zigzag frontier of the delay reduction was discovered. Findings from this research shed light on the feasibility and effectiveness of DLR on various types of road segments. [ABSTRACT FROM AUTHOR]

In order to increase the efficiency of the order-picking process, warehouses are forced to find ways to adopt to constantly intensifying changes in the assortment and quantities of stored products. Accordingly, we present a methodology that deals with such a problem at a tactical level by defining the optimal size and an allocation of products within the order-picking area of the most typical order-picking setting. The methodology combined two methods, dynamic programming and simulation modelling, with the aim of taking advantages of their positive features. In that sense, the optimal allocation of products for different sizes of the order-picking zone were obtained by the dynamic programming approach. Afterwards, the influence of a demand's seasonality and variations were treated by the simulation model, so that the more realistic performances of the system were captured for the optimal allocation of products. The methodology was tested on the retailer data with significant week seasonality. The obtained results confirmed the practical applicability of the methodology in real systems, while the sensitivity analysis of results showed that special attention and effort should be given to the determination of costs related to the engagement of order-pikers, storage equipment and unit replenishment during a planning period. [ABSTRACT FROM AUTHOR]

Single nucleotide polymorphisms detected in the solute carrier member family-22 has been shown to result in a variable response in the treatment of type 2 diabetes mellitus with Metformin. This study predicted a three-dimensional protein structure for the SLC22A2 protein sequence using AlphaFold 2 and modelled five haplotypes within SLC22A2 protein structure observed in the Xhosa population of South Africa. The protein models were used to determine the effect(s) of haplotype variations on the transport function of Metformin and 10 other drugs by the SLC22A2 protein. Molecular dynamic simulation studies, molecular docking and interaction analysis of the five SLC22A2 haplotypes were performed in complex with the ligand 5RE in a POPC lipid bilayer to understand the mechanism of drug binding. Weakest binding free energy was found between 5RE and haplotype 1. Molecular docking studies indicated the top binding ligands as well as Metformin to bind inside the transport channel in all haplotypes increasing the probability of Metformin inhibition during co-administration of drugs. Metformin showed reduced binding affinity and number of interactions compared to the top four binding molecules. Molecular dynamic simulation analysis indicated that haplotypes 1, 3 and 4 were less stable than 2 and 5. The findings suggest haplotypes 4 and 5 having stronger preference for large inhibitor molecule binding in the active site and this could result in haplotypes 4 and 5 demonstrating reduced Metformin clearance via the SLC22A2 transporter during co-administration of drugs. The current study is the first to investigate the potential effect(s) of haplotype variation on the protein structure of SLC22A2 to assess its ability to transport Metformin in an indigenous South African population. [ABSTRACT FROM AUTHOR]

Planetary rovers may traverse terrains with complex geometries and variable physical properties, but their mobility behaviors are complicated and difficult to simulate precisely. This article focuses on high-fidelity dynamic modeling and simulation for a type of rovers that incorporate single-input-multi-output joints to enhance terrain adaptability, which has been used on China's Tianwen-1 Mars rover. A novel multibody dynamic model and its solutions are derived first with consideration of single-input-multi-output joints. Then, a unified terramechanics model is proposed, considering variable terrain surfaces and covering rover's motion states of skidding, slipping, and steering, solved the problem of simulation instability caused by model switching between soft and hard terrains. As the contact areas of wheels with various terrains and resultant sinkage are dominant factors to ensure fidelity but difficult to determine, a new terrain modeling method for calculating contact area and wheel sinkage is developed using digital elevation map with physical properties. A simulation system is developed, integrating all the above models, and verified with physical experiments and commercial software. The relative simulation errors that have been achieved are less than 5.9% for bogie angles, 6.1% for drawbar pull, and 3.4% for slip ratios, demonstrating high fidelity simulation results. [ABSTRACT FROM AUTHOR]

An energy storage system based on a Proton Exchange Membrane (PEM) electrolyzer system, which could be managed by a nanoGrid for Home Applications (nGfHA), is able to convert the surplus of electric energy produced by renewable sources into hydrogen, which can be stored in pressurized tanks. The PEM electrolyzer system must be able to operate at variable feeding power for converting all the surplus of renewable electric energy into hydrogen in reasonable time. In this article, the dynamic electric simulation model of a PEM electrolyzer system with its pressurized hydrogen tanks is developed in a proper calculation environment. Through the calculation code, the stack voltage and current peaks to a supply power variation from the minimum value (about 56 W) to the maximum value (about 440 W) are controlled and zeroed to preserve the stack, the best range of the operating stack current is evaluated, and hydrogen production is monitored. [ABSTRACT FROM AUTHOR]

Dynamic simulation is a powerful tool for accurately evaluating the thermal demands of buildings and assessing the impact of energy refurbishment actions on their final consumption. Conversely, semi-stationary models are widely adopted in commercial applications for its simplified approach, which reduce calculation times, resulting in standardized results showing a certain deviation with respect to the real energy This paper presents the energy and economic comparison between the dynamic simulation and semi-stationary approaches for the calculation of primary energy demand of residential buildings. The semi-stationary method, used by the legislation to calculate the buildings energy label, is based on an energy performance parameter, not representative of the real energy demand. Conversely, an approach based on dynamic simulation provides a more reliable estimation of the primary energy demand. The main novelty of this paper is to numerically prove that the energy and economic savings calculated by means of software based on the current legislation may be overestimated. In this work, the dynamic simulation of the building-plant system is performed by TRaNsient SYstem Simulation (TRNSYS) program. Each building apartment is divided in thermal zones, where the internal heat gains are defined in detail. The semi-stationary simulation of the building-plant system is performed according to the Italian standard UNI TS 11300. The models allow one to evaluate the yearly primary energy demand, along with the energy bill and CO 2 emissions. A specific case study is developed for a residential building located in Naples (Italy). The models are used to calculate the building energy demand for several scenarios, considering different thermal transmittances of the building elements. The results show that the semi-stationary method overestimates of primary energy saving, equal to 64.7 %, with respect to the one calculated with the dynamic approach, equal to 43.2 %. • Semi-stationary and dynamic simulations were compared for residential buildings. • Critical evaluation of energy and economic savings due to the building refurbishment. • Primary energy savings of 65 % and 43 % by semi-stationary and dynamic simulation. • Dynamic simulation is needed within the legal frame of energy efficient buildings. [ABSTRACT FROM AUTHOR]

With the continuous expansion of computer system simulation applications, the dynamic system modeling problems that people face have become more and more complex. This paper mainly studies dynamic system simulation models and algorithms based on artificial neural networks. This article mainly focuses on some practical problems of dynamic system simulation, and studies the artificial neural network model and corresponding algorithm suitable for dynamic system modeling. First, it summarizes the existing artificial neural network simulation models of dynamic systems: multi-layer feedforward network relationship model without feedback, recursive network relationship model with feedback, and their network topology diagrams are drawn. Secondly, a quantum genetic algorithm is proposed to optimize the parameters of artificial neural networks and feedforward process neural networks. To achieve the preprocessing of the parameters. Next, based on the analysis and research of BP neural network theory, this paper comprehensively compares the neural network models established under various network structures and algorithms, and establishes the simulation model based on the BP neural network monitoring data system, and compares the results with the monitoring data obtained in the field. The hidden layer of neural network with 4 and 6 nodes will increase the convergence step. When the number of nodes is 10 and 12, the convergence rate may reach 46 steps. This shows that if the non-display layer with different number of nodes in the same layer is selected for the same system simulation model based on artificial neural network, the repetition number of convergence steps of the prediction model will be different. [ABSTRACT FROM AUTHOR]

The dynamic vibration absorber (DVA) has a broad application background in slender structure vibration reduction, such as in machine gun systems, micro actuators, and so on. Rapid modeling and simulation of the DVA-beam system are of great importance for dynamic performance, evaluation, and finally, the structural design. The primary motivation for this paper is to present a reliable and convenient technique for the modeling and computation of the DVA-beam system. A novel DVA-beam element, which consists of a beam segment and a DVA, is presented. In this element, the DVA position can be arbitrarily allocated, whether on the beam node or within the beam domain. In this way, the beam can be modeled with a few elements to save on computing costs and maintain ideal modeling accuracy. An element deactivating method, which endows the DVA-beam element with the ability to simulate a bare beam and a DVA-beam structure simultaneously, is proposed. Some numerical examples were carried out to validate the reliability of the DVA-beam element in addressing different kinds of boundary conditions by comparing the beam tip responses with those simulated by ADAMS software, and good agreements were observed. Finally, two DVA optimization examples were conducted to investigate the effectiveness and applicability of the DVA-beam element in engineering optimization. The performance was impressive. [ABSTRACT FROM AUTHOR]

Classical molecular-dynamics simulations (CMDS) have been conducted to investigate one of the main mechanisms responsible for absorption of radiation by matter, namely, stimulated inverse bremsstrahlung. CMDS of two components plasmas (electrons and ions) for a large range of electron densities and electron temperatures, for ionization Z = 1, were carried out with 2 × 106 particles using the code LAMMPS. A parameterized model (with six adjustable constants), which encompasses most theoretical models proposed in the past to quantify heating rate by stimulated inverse bremsstrahlung, serves as a reference for comparison to our simulations. CMDS results are precise enough to rule out elements of these past models such as coulomb logarithms depending solely upon laser pulsation ω and not upon intensity. The six constants of the parameterized model have been adjusted, and the resulting model matches all our CMDS results and those of previous CMDS in the literature. [ABSTRACT FROM AUTHOR]

Friction plays an important role in the injection mechanism of squeeze casting machines. To control the injection process of aluminum alloy more accurately, a novel numerical simulation method based on a friction-integrated finite element (FE) model is proposed in this paper. A friction mechanism model of the injection mechanism based on thermohydrodynamic lubrication (THDL) was developed, and with the application of a friction-generating experiment, the influences of temperature, interaction speed, and fit clearance on the friction-related characteristics of an injection mechanism were ultimately evaluated. The THDL model was integrated into a thermomechanical coupling FE model to simulate the multicycle injection process, and the simulation results were compared with those of the general model in the absence of friction. The effects of friction on the temperature, deformation, and fit clearance of the injection mechanism were analyzed. The accuracy of the friction-integrated model was also evaluated in an injection experiment. A multicycle injection experiment platform that measures the temperature and deformation of the injection mechanism online in real-time was developed. When the numerical simulation results of the two models were compared with the experimental data, the friction-integrated model achieved more reliable results than the general model. [ABSTRACT FROM AUTHOR]

District heating and cooling (DHC) networks, and in particular, the fifth generation of DHC networks, offer great potential in increasing the overall system efficiency and reducing CO2 emissions in the heating and cooling of urban districts. Due to the growing complexity of these energy systems, the use of new planning methods, such as the use of dynamic simulation models based on Modelica, becomes more important. However, especially with large, complex thermal networks, there is a high effort for manual model construction and parameterization. For this reason, we present a framework for automated model generation of DHC networks based on simulation models in Modelica written in Python. The core function of the Python framework is to transform a graph representation of a district heating network into a dynamic simulation model. The authors briefly describe the workflow and demonstrate its applicability with three different use cases. We investigate the impact of different design decisions, e.g., comparing the difference between central and decentral pumps as well as a combination of both in one network. In addition, we present the results of evaluating the impact of different network temperature levels or pipe insulation compared to the overall energy supplied to the network, leading to the conclusion that the presented framework is capable of reducing the manual effort for performing DHC network simulations with Modelica and allows to easily perform parameter studies in an early planning phases in the future. [ABSTRACT FROM AUTHOR]

The 660 MW ultra-supercritical circulating fluidized bed (CFB) boiler, which is the maximum capacity and largest scale boiler in the world has entered construction stage in China. This study established a full-scale dynamic simulation model of the 660 MW ultra-supercritical at 100% boiler maximum continuous rating (BMCR) condition. The model consists of an air-flue gas system, a water-steam system, and an ash circulation system. The "core-annulus" of the gas-solid two-phase flow structure and "six-equation" model of water-steam two-phase flow were applied to simulate the behaviors of the gas-solid phase and water-steam system, respectively. The model was calibrated and verified at 100% BMCR condition, and the steady-state simulation results presented a high accuracy compared with the designed parameters. A dynamic simulation of three typical conditions were carried out as well, including a 5% feed water decrease, 5% air decrease, and 5% coal decrease, respectively. The results showed that the dynamic simulation model established in this study can simulate the dynamic behaviors of the 660 MW ultra-supercritical CFB boiler reasonably. [ABSTRACT FROM AUTHOR]

Sustainable wildlife trade is critical for biodiversity conservation, livelihoods, and food security. Regulatory frameworks are needed to secure these diverse benefits of sustainable wildlife trade. However, regulations limiting trade can backfire, sparking illegal trade if demand is not met by legal trade alone. Assessing how regulations affect wildlife market participants' incentives is key to controlling illegal trade. Although much research has assessed how incentives at both the harvester and consumer ends of markets are affected by regulations, little has been done to understand the incentives of traders (i.e., intermediaries). We built a dynamic simulation model to support reduction in illegal wildlife trade within legal markets by focusing on incentives traders face to trade legal or illegal products. We used an Approximate Bayesian Computation approach to infer illegal trading dynamics and parameters that might be unknown (e.g., price of illegal products). We showcased the utility of the approach with a small‐scale fishery case study in Chile, where we disentangled within‐year dynamics of legal and illegal trading and found that the majority (∼77%) of traded fish is illegal. We utilized the model to assess the effect of policy interventions to improve the fishery's sustainability and explore the trade‐offs between ecological, economic, and social goals. Scenario simulations showed that even significant increases (over 200%) in parameters proxying for policy interventions enabled only moderate improvements in ecological and social sustainability of the fishery at substantial economic cost. These results expose how unbalanced trader incentives are toward trading illegal over legal products in this fishery. Our model provides a novel tool for promoting sustainable wildlife trade in data‐limited settings, which explicitly considers traders as critical players in wildlife markets. Sustainable wildlife trade requires incentivizing legal over illegal wildlife trade and consideration of the social, ecological, and economic impacts of interventions. Article impact statement: Simulation models that explicitly consider traders' roles in wildlife markets can help support reduction in illegal wildlife trade. [ABSTRACT FROM AUTHOR]

Background: This study shows how dynamic simulation modeling can be applied in the context of the nationwide implementation of Whole Genome Sequencing (WGS) for non-small cell lung cancer (NSCLC) to inform organizational decisions regarding the use of complex and disruptive health technologies and how these decisions affect their potential value.Methods: Using the case of the nationwide implementation of WGS into clinical practice in lung cancer in the Dutch healthcare system, we developed a simulation model to show that including service delivery features across the diagnostic pathway can provide essential insight into the affordability and accessibility of care at the systems level. The model was implemented as a hybrid Agent-Based Model and Discrete-Event Simulation model in AnyLogic and included 78 hospital agents, 7 molecular tumor board agents, 1 WGS facility agent, and 5313 patient agents each year in simulation time.Results: The model included patient and provider heterogeneity, including referral patterns, capacity constraints, and diagnostic workflows. Patient preference and adoption by healthcare professionals were also modeled. The model was used to analyze a scenario in which only academic hospitals have implemented WGS. To prevent delays in the diagnostic pathway, the capacity to sequence at least 1600 biopsies yearly should be present. There is a two-fold increase in mean diagnostic pathway duration between no patients referred or all patients referred for further diagnostics.Conclusions: The systems model can complement conventional health economic evaluations to investigate how the organization of the workflow can influence the actual use and impact of WGS. Insufficient capacity to provide WGS and referral patterns can substantially impact the duration of the diagnostic pathway and thus should be considered in the implementation of WGS. [ABSTRACT FROM AUTHOR]

Increasing competition and globalization that encompasses all dealings in the world of business compel SMEs to seek more successful organizational and management modes and approaches. This paper presents a simulation model for the application of Lean methods and tools in SMEs and their impact on the improvement of production processes and product sustainability. The Lean concept can be used to achieve more efficient production whilst manufacturing lower-cost products including shorter manufacturing cycle, high quality, and added value. Research results show the usefulness of the application of dynamic simulations in the detection of critical places in processes and the usefulness of the application of relevant Lean methods and Lean tools for process improvement. Simulation results underline better performance of product manufacturing through the use of Lean tools with the aim to eliminate any waste. Reengineering the assembly line focuses on the following aspects, namely reducing waste, internal logistics, redesigning workplaces, and changing the workplace layout. [ABSTRACT FROM AUTHOR]

Phase sequence exchange (PSE) is a recently developed emergency control technology. PSE uses power electronic devices to switch the three-phase sequence, which reduces the power angle of the generator by 120° and prevents the system from losing stability. In this work, the structure of the PSE device is improved. Based on the original nine solid-state circuit breakers (SSCBs), three mechanical circuit breakers (MCBs) are added. Normally, the current flows through the MCBs, which greatly reduces the conduction loss of the PSE device. Once the generator is identified as being out-of-step, the MCBs quickly open to transfer the current to the SSCBs. When the power angle threshold of the PSE is reached, the SSCBs are switched to complete PSE. In this article, the transient characteristics of the current transfer and PSE processes are analyzed. Based on the real time digital simulation system (RTDS) platform, dynamic simulation tests of the improved PSE prototype are carried out under different conditions. Experiments and calculations demonstrate that the improved PSE device can meet the technical requirements of PSE, and that the conduction power loss is reduced by 96% on average. [ABSTRACT FROM AUTHOR]