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The steelmaking–continuous casting process (SCCP) is a complex manufacturing process which exhibits the distinct features of process manufacturing. The SCCP involves a variety of production elements, such as multiple process routes, a wide array of smelting and auxiliary devices, and a variety of raw and auxiliary materials. The production-simulation of SCCP holds a natural advantage in being able to accurately depict the intricate production behavior involved, and this serves as a crucial tool for optimizing the production operation of the SCCP. This paper thoroughly considers the various production elements involved in the SCCP, such as the fluctuation of the converter smelting cycle, fluctuation of heat weight, and ladle operation. Based on the Plant Simulation software platform, a dynamic simulation model of the SCCP is established and detailed descriptions are provided regarding the design of an SCCP using dynamic-operation rules. Additionally, a dynamic operational control program for the SCCP is developed using the SimTalk language, one which ensures the continuous operation of the caster in the SCCP, using the discrete simulation platform. The effectiveness of the proposed dynamic simulation model is verified by the total completion time of the production plan, the transfer time of the heat among the different processes, and the frequency of ladle turnover. The simulation's results indicate that the dynamic simulation model has a satisfactory effect in simulating the actual production process. On this basis, the application effects of different schedules are compared and analyzed. Compared with a heuristic schedule, the optimized schedule based on the "furnace–machine coordinating" mode reduces the weighted value of total completion time by 8.7 min, reduces the weighted value of transfer waiting time by 45.5 min, and the number of rescheduling times is also reduced, demonstrating a better application effect and verifying the optimizing effect of the "furnace–machine coordinating" mode on the schedule. [ABSTRACT FROM AUTHOR]

Mathematical modeling of bearing faults, worn tool holder taper contact interface, and unbalance are presented and integrated into a digital dynamic model of spindles in Part I of this paper. These faults lead to changes in preload and dynamic stiffness over time, consequently resulting in observable vibrations. This paper predicts the vibrations of a spindle at a particular measurement location by simulating the presence of a specific fault or multiple faults during spindle rotation. The vibration spectra generated by the digital spindle model at the spindle speed and its harmonics, the changes in the natural frequencies, and dynamic stiffnesses are correlated to faults with experimental validations. The simulated vibration spectrums are later used in training an artificial neural network for fault condition monitoring presented in Part III of the paper. [ABSTRACT FROM AUTHOR]

Aiming at the difficulty of dynamic modeling of a hybrid robotic arm, a dynamic model system of industrial robotic arm based on Simscape Multibody was established with the MG400 robotic arm as the research object, which combines the motion control and data acquisition modules. The model is dynamically visualized and provides a convenient platform for studying the control algorithm of the robot arm. In response to the issues of sluggish speed and substantial position error in robot trajectory tracking control of a traditional controller, a variable gain iterative learning control methodology was designed. The robot arm control system model was employed to corroborate the trajectory tracking control under the stipulated target trajectory. The empirical outcomes indicate that in comparison to the traditional controller and the fixed-gain iterative learning controller, the variable-gain iterative learning controller can regulate the robot end trajectory more precisely, with swift tracking speed and accurate tracking posture, demonstrating commendable feasibility and portability. It offers an open-source research and development platform for the dynamic modeling of robot arm and a potent solution for the control strategy of robot arm. [ABSTRACT FROM AUTHOR]

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]

Coal-resource-based cities, as one of the important types of typical resource-based cities in China, have strong characteristics of instability, sensitivity, and fragility, exhibiting a series of vulnerability features of the human-land system. Previous studies have lacked a deeper investigation into the vulnerability of such cities from the perspective of coupling feedback mechanisms among various elements or subsystems. This paper adopts Bohle et al.'s "Dual Structure Model" of vulnerability to establish an indicator system for vulnerability warning in coal-resource-based cities. Using Fushun City as a sample, a dynamic simulation model of vulnerability in coal-resource-based cities is constructed based on system dynamics for warning simulation calculations, analyzing the evolution trend of vulnerability in Fushun City from 2010 to 2022. The results show the following: (1) from 2010 to 2022, the urban vulnerability of Fushun City transitioned from a medium warning level to a relatively safe level, showing a trend of annual reduction and improvement, undergoing three development stages of significant reduction, fluctuation stabilization, and slight rebound. (2) Due to the causal relationships among various elements within the vulnerability subsystems of Fushun City, differences exist in the contribution levels of vulnerability subsystems during the period 2010–2022, under the combined effects of sensitivity and adaptability factors. The contribution rate of the natural subsystem was the highest from 2010 to 2014, while, from 2016 to 2019, urban vulnerability began to shift towards an economically and socially dominant type. Influenced by the pandemic, Fushun City's overall vulnerability has shown an upward trend since 2020 compared to the previous stage. Finally, specific policy suggestions are proposed for Fushun City to cope with vulnerability changes based on the analysis results, providing a theoretical basis for achieving sustainable development in such coal-resource-based cities. [ABSTRACT FROM AUTHOR]

Shimmy is one of the important factors affecting the ride comfort and lateral stability of straddle-type monorail vehicles with single-axle bogies (SMVS). To obtain the main parameters affecting SMVS shimmy, a global sensitivity analysis strategy for SMVS shimmy is proposed. The shimmy response surface model is constructed, and the sensitivity analysis of the shimmy response surface model is carried out by the Sobol method. Based on this, the shimmy factor model of SMVS is established by factor analysis method. A novel SMVS shimmy analysis method based on factor model is proposed. The shimmy factor model is verified by the dynamic model of SMVS. The results show that 11 main factors affecting the shimmy are obtained by sensitivity analysis. Through the dimension reduction technology of factor analysis, four main factors affecting SMVS shimmy are extracted. The complex coupling relationship between the shimmy factors of SMVS is revealed. The established shimmy factor model can effectively analyse the shimmy state of SMVS, and the dynamic simulation results also show consistency. This study not only proposes a new perspective to understand the SMVS shimmy mechanism, but also provides the foundation for further optimal design of monorail vehicle stability. [ABSTRACT FROM AUTHOR]

Reductions of carbon dioxide emissions from the building sector are mandatory for climate protection. This calls for both a reduction of the construction material and energy as well as a reduction of the operational energy. Against this background, a novel facade-integrated adsorption system for solar cooling of lightweight buildings is proposed and theoretically investigated in this work. For this purpose, a detailed simulation model is developed to analyze both the processes in the single components as well as the overall system behavior. The proposed system consists of the three components adsorber, condenser and evaporator, which are connected vacuum-tight and are coupled by vapor transfer. The simulation results of a defined reference case yield cooling rates of 54   W per installed square meter of adsorber facade. The cooling power can be maintained for 12 h, confirming the applicability of the proposed system. Furthermore, a comprehensive parametric study is carried out in order to identify an optimum set of parameter values for maximum cooling rate under the assumed conditions. The results reveal that controlled constant cooling rates of 105   W per square meter of adsorber facade can be reached and a maximum peak power of 145   W per square meter of adsorber facade is possible. [ABSTRACT FROM AUTHOR]

Purpose: This paper aims to present numerical simulations for a series of flight processes for the postlaunching stage of the "balloon-borne UAV system." It includes the balloon further ascent motion after airborne launching. In terms of unmanned aerial vehicles (UAVs), the tailspin state and the charge-out process with an anti-tailspin parachute-assisted suspending are analyzed. Then, the authors conduct trajectory optimization simulations for the long-distance gliding process. Design/methodology/approach: The balloon kinematics model and the parachute Kane multibody dynamic model are established. Using steady-state tailspin to reduced-order analysis and achieving change-out simulation by parachute suspension dynamic model. A reentry optimization control problem is developed and the Radau pseudo-spectral method is used to calculate the glide trajectory. Findings: The established dynamic model and trajectory optimization method can effectively simulate the motion process of balloons and UAVs. The system mass reduction for launching UAVs will not cause damage to the balloon structure. The anti-tailspin parachute can reduce the UAV attack angles effectively. The UAV can glide to the designated target position by adjusting the attack angle and sideslip angle. The farthest flight distance after launching from 20 km height is 94 km and the gliding time is 40 min, which demonstrates the potential application advantage of high-altitude launching. Practical implications: The research content and related conclusions of this article achieve a closed-loop analysis of the flight mission chain for the "balloon-borne UAV system," which provides simulation references for relevant balloon launching experiments. Originality/value: This paper establishes a complete set of numerical simulation models and can effectively analyze various postlaunching behaviors. [ABSTRACT FROM AUTHOR]

To explore the impact of wheel-rail excitation on the dynamic performance of axle box bearings, a dynamic model of the high-speed train including axle box bearings is developed. Subsequently, the dynamic response characteristics of the axle box bearing are examined. The investigation focuses on the acceleration characteristics of bearing vibration under excitation of track irregularities and wheel flats. In addition, experiments on both normal and faulty bearings are conducted separately, and the correctness of the model and some conclusions are verified. According to the research, track irregularity is unfavorable for bearing fault detection based on resonance demodulation. Under the same speed conditions, the acceleration peak of bearing is inversely proportional to the length of the wheel flat and directly proportional to its depth. The paper will contribute to a deeper understanding of the dynamic performance of axle box bearings. [ABSTRACT FROM AUTHOR]

A musculoskeletal (MSK) model is a valuable tool for assessing complex biomechanical problems, estimating joint torques during motion, optimizing motion in sports, and designing exoskeletons and prostheses. This study proposes an open-source upper body MSK model that supports biomechanical analysis of human motion. The MSK model of the upper body consists of 8 body segments (torso, head, left/right upper arm, left/right forearm, and left/right hand). The model has 20 degrees of freedom (DoFs) and 40 muscle torque generators (MTGs), which are constructed using experimental data. The model is adjustable for different anthropometric measurements and subject body characteristics: sex, age, body mass, height, dominant side, and physical activity. Joint limits are modeled using experimental dynamometer data within the proposed multi-DoF MTG model. The model equations are verified by simulating the joint range of motion (ROM) and torque; all simulation results have a good agreement with previously published research. [ABSTRACT FROM AUTHOR]

Several kinesin-5 motors (kinesin-5s) exhibit bidirectional motility. The mechanism of such motility remains unknown. Bidirectional kinesin-5s share a long N-terminal nonmotor domain (NTnmd), absent in exclusively plus-end-directed kinesins. Here, we combined in vivo, in vitro, and cryo-electron microscopy (cryo-EM) studies to examine the impact of NTnmd mutations on the motor functions of the bidirectional kinesin-5, Cin8. We found that NTnmd deletion mutants exhibited cell viability and spindle localization defects. Using cryo-EM, we examined the structure of a microtubule (MT)-bound motor domain of Cin8, containing part of its NTnmd. Modeling and molecular dynamic simulations based on the cryo-EM map suggested that the NTnmd of Cin8 interacts with the C-terminal tail of ß-tubulin. In vitro experiments on subtilisin-treated MTs confirmed this notion. Last, we showed that NTnmd mutants are defective in plus-end-directed motility in single-molecule and antiparallel MT sliding assays. These findings demonstrate that the NTnmd, common to bidirectional kinesin-5s, is critical for their bidirectional motility and intracellular functions. [ABSTRACT FROM AUTHOR]

Purpose: This study proposes a tensegrity-based traction structure with D-bar dual cable units. It is used to connect the airship and the ground to stabilize the airship. Design/methodology/approach: The mathematical models and dynamic models of the D-bar dual cable (hereafter referred to as DD cable) unit of the tensegrity-based traction structure are established. Based on the minimum mass method, the mass of the DD cable unit in the critical state (cable member is yielding, or bar member is buckling or yielding) is analyzed. Then, the tensile strength of the DD cable unit and single cable unit under the same condition is compared using the control variate method. Finally, based on ANSYS dynamic simulation, the stability of the two structures under the same external force disturbance was tested. Findings: Expressions for the minimum mass of the DD cable unit under different failure conditions are solved. Dynamic simulation results show that the capacity of resisting disturbance of the DD cable unit is much better than that of the single cable unit under the same wind speed. So, we find a structure more suitable for the fixed connection of an airship. Originality/value: This study helps to provide theoretical reference and thinking for the practical application of the traction structure with a D-bar dual cable unit. [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]

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]

Percutaneous needle insertion constitutes a widely adopted technique for performing minimally invasive operations. Robot-assisted needle placement and virtual surgical training platforms have the potential to significantly improve the accuracy of these operations. For this, the development of mathematical models that provide a complete characterization of the underlying dynamics of medical needles is considered of paramount importance. In this paper, we develop two three-dimensional nonlinear rigid/flexible dynamic models of brachytherapy and local anaesthetic transperineal biopsy (LATP) needles. The proposed models relax the assumptions of previous investigations, quantify the vibrational behaviour and the rigid-body dynamics of medical needles and allow for real-time haptic and visual feedback information. Their accuracy and computational efficiency are assessed and validated using commercial software. The results show that, among the examined methods, the Rigid Finite Element Method provides the most accurate and numerically efficient solution for capturing the dynamics of flexible medical needles. [ABSTRACT FROM AUTHOR]

Relative to isotropic organic solvent medium, the structure and conformation of a reactant molecule in an organized and confining medium are often different. In addition, because of the rigidity of the immediate environment, the reacting molecule have a little freedom to undergo large changes even upon gaining energy or modifications in the electronic structure. These alterations give rise to differences in the photochemistry of a molecular and supramolecular species. In this study, one such example is presented. α-Alkyl dibenzylketones upon excitation in isotropic solvents give products via Norrish type I and type II reactions that are independent of the chain length of the alkyl substituent. On the other hand, when these molecules are enclosed within an organic capsule of volume ~ 550 Å3, they give products that are strikingly dependent on the length of the α-alkyl substitution. These previously reported experimental observations are rationalized based on the structures generated by molecular modeling (docking and molecular dynamics (MD) simulations). It is shown that MD simulations that are utilized extensively in biologically important macromolecules can also be useful to understand the excited state behavior of reactive molecules that are part of supramolecular assemblies. These simulations can provide structural information of the reactant molecule and the surroundings complementing that with the one obtained from 1 and 2D NMR experiments. MD simulated structures of seven α-alkyl dibenzylketones encapsulated within the octa acid capsule provide a clear understanding of their unique behavior in this restricted medium. Because of the rigidity of the medium, these structures although generated in the ground state can rationalize the photochemical behavior of the molecules in the excited state. [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 this work, an attempt is made to develop an innovative alternative stochastic interconnected hybrid dynamic model for time-to-event processes in a systematic and unified way. The procedure is composed of the following components: (1) development of a continuous-time state dynamic model, (2) formulation of an interconnected hybrid dynamic model composed of both continuous and discrete-time states of time-to-event processes, (3) derivation of conceptual computational interconnected dynamic algorithm for time-to-event data statistic, and (4) construction of conceptual and computational simulation dynamic procedure for state and parameter estimations. The development of the presented approach is motivated by parameter and state estimation of time-to-event processes in biological, chemical, engineering, epidemiological, medical, military, and social dynamic processes under the influence of discrete-time intervention processes. The presented algorithm is independent of any particular form of survival distributions or data sets. Moreover, it does not require a closed form survival function distributions. The introduction of intervention processes provides a measure of influence of new tools/procedures/approaches in continuous-time states of time-to-event dynamic process. In particular, it generates a measure of the degree of sustainability, survivability, reliability of a time-to-event process. In addition, intervention processes provide comparison between the past and currently used tools/procedures/approaches/etc. The developed procedure coupled with modified Local Lagged Adapted Generalized Method of Moments (LLGMM) approach also provides a measure of degree of confidence, prediction, and planning assessments. [ABSTRACT FROM AUTHOR]

Compared with the traditional docking mechanism, a low-impact docking mechanism (LIDM) has a big advantage, that is, LIDMs can realize low-impact docking by controlling the movement of the driving rods in real-time. In this process, the load sensing ring (LSR) of the chaser spacecraft is adjusted in real-time according to the position and attitude of the target spacecraft, which requires that the LIDM has high transmission efficiency, so that the position and attitude of the LSR can be changed rapidly under the motion of the driving rods and respond to the position and attitude requirements of the docking control system to the LSR as soon as possible. In this paper, a transmission efficiency solution and an optimization method suitable for LIDMs are proposed. The LIDM dynamic model and transmission efficiency model are established, and an improved genetic algorithm with better convergence effect is proposed and used to optimize the transfer efficiency. The results of numerical examples in this paper show that the improved genetic algorithm has stronger global optimization ability when calculating high-complexity optimization problems. In the optimized LIDM configuration parameters, the size of LSR and the bottom reference circle are close to the lower limit and upper limit of the given size limit, respectively, and the instantaneous transmission force ratio is increased from 0.6477 to 0.9160. The reliability of the optimized results is verified in dynamic simulation software. This study provides ideas and methods for the design and optimization of subsequent high transmission efficiency mechanisms. [ABSTRACT FROM AUTHOR]

The digital twin workshop is a new workshop operation paradigm that enables precise decision-making by fusing virtual and physical space. As a complex manufacturing system, the digital twin model of the workshop must integrate models from different domains in order to provide personalized services. The interoperability of multi-domain models and the dynamic update of parameters become obstacles. In this paper, a knowledge graph (KG)-based multi-domain model integration method for digital twin workshops is proposed. The multi-domain model integration architecture based on KG is consisted of model element, model ontology, model data, semantic integration, and network connection. Then, the KG of multi-domain model for design, manufacturing, and simulation is constructed through ontology modeling and knowledge extraction. On this basis, multi-domain model integration is realized through semantic inference and knowledge query. The model parameters are updated through file exchange during the dynamic simulation. Finally, multiple scenarios in the subassembly workshop for hull construction are used to verify the efficacy of the proposed method. During the assembly and welding of hull parts, the integration of the product model, equipment model, and simulation model is realized, which assists in meeting the service requirements of multiple business scenarios. [ABSTRACT FROM AUTHOR]

To address the problem of insufficient real-world data on planetary gearboxes, which makes it difficult to diagnose faults using deep learning methods, it is possible to obtain sufficient simulation fault data through dynamic simulation models and then reduce the difference between simulation data and real data using transfer learning methods, thereby applying diagnostic knowledge from simulation data to real planetary gearboxes. However, the label space of real data may be a subset of the label space of simulation data. In this case, existing transfer learning methods are susceptible to interference from outlier label spaces in simulation data, resulting in mismatching. To address this issue, this paper introduces multiple domain classifiers and a weighted learning scheme on the basis of existing domain adversarial transfer learning methods to evaluate the transferability of simulation data and adaptively measure their contribution to label predictor and domain classifiers, filter the interference of unrelated categories of simulation data, and achieve accurate matching of real data. Finally, partial transfer experiments are conducted to verify the effectiveness of the proposed method, and the experimental results show that the diagnostic accuracy of this method is higher than existing transfer learning methods. [ABSTRACT FROM AUTHOR]

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]

Coastal aquaculture is an important economic activity in India dominated majorly by shrimp culture, which involves a range of interconnected processes that are challenging to analyse and optimise without a systematic approach. System dynamics modelling is a useful tool for understanding and predicting the behavior of complex coastal aquaculture systems. here, we review the status of dynamic simulation modelling works undertaken in aquaculture, which can provide directives for various researchers working on developing simulation models for shrimp aquaculture. There is a need to assess the impact of dynamic forces on the animals during the culture period which could be addressed through these models. System dynamic models assist decision-makers to augment potential measures for aquaculture-related problems under different possible scenarios. System dynamic models developed in aquaculture were related to feeding, water quality parameters, nitrogen dynamics, growth, etc. The strengths and limitations of software packages used in developing the simulation models are discussed. Considering the economic potential of shrimp aquaculture, it is important to develop an integrated dynamic model for predicting all the sub-processes of shrimp aquaculture. [ABSTRACT FROM AUTHOR]

Knowing the directions of rupture propagation of palaeo-earthquakes is a challenging, yet important task for our understanding of earthquake physics and seismic hazard, as the rupture direction significantly influences the distribution of strong ground motion. Recent studies proposed a relationship between the direction of rupture propagation and curvature of slickenlines formed during seismic slip. The relationship was established using a global catalogue of historic surface-rupturing earthquakes and dynamic models of idealized, planar faults. At the same time, some slickenlines previously documented on geometrically complex fault segments show their convexity opposite from the simple model prediction, which we refer to as 'abnormal convexity'. To explain such observations, we perform simulations of spontaneous earthquake ruptures on non-planar and rough faults. We find that in the case of strike-slip faults, a non-planar fault model can lead to abnormal convexity of slickenlines in places where the fault dip angle changes abruptly from the average dip of the fault. Abnormal convexity of slickenlines is produced when the initial along-dip stresses are larger than, and are opposite in direction to, the dynamic stresses imparted by the mixed-mode rupture. Such results are also confirmed in our rupture simulations with a rough fault. Our results also show that the parameter space for which abnormal convexity of slickenlines occurs near Earth's surface is narrow, especially when the fault strength and initial shear stresses increase with depth. Nevertheless, slickenlines on geometrically complex faults need to be carefully interpreted and investigation of rupture direction using curved slickenlines should focus on structurally simple parts of faults. [ABSTRACT FROM AUTHOR]

A bearing‐vehicle‐track coupling dynamic model is built in this paper and the validity of the model is proved by comparing the simulation data with the theoretical data. Based on this model, the influence of wheel diameter difference (WDD) on the dynamic behavior of wheelset bearing is studied. The results demonstrate that when the bogie has a rear WDD, lateral displacement (LaD) of the front wheelset is the smallest. When the bogie has an anti‐phase WDD, LaD of the rear wheelset is the smallest, while when the bogie has an in‐phase WDD, LaD of the front and rear wheelsets is the largest, and LaD of the front and rear WDD is between the two, which is in line with the theoretical analysis results. Compared with LaD results of the wheelset bearing outer raceway under normal conditions, when the wheel has a diameter difference, LaD distance of the outer race increases with the WDD increasing, and the frequency of lateral movement also increases with the increase against the WDD gradation. The high‐frequency and large‐distance lateral movement of the wheelset bearing outer race under the WDD will increase the roller‐outer raceway force, and accelerate the failure of the bearing. [ABSTRACT FROM AUTHOR]

Background Breast reconstruction (BR) using autologous free flaps has been shown to have numerous psychosocial and quality-of-life benefits. Unfortunately, the microsurgical learning curve is quite steep due to some unique operative challenges. Currently, there is no realistic simulation model that captures real-life respiratory excursion and the depth of internal mammary vessels within the compact recipient site. The purpose of this study was to delineate intraoperative measurements of depth and motion, describe the resulting simulation model, and conduct a pilot study evaluating the simulator as an educational resource. Methods This is a single-center, ethics-approved study. For the intraoperative measurements, all consecutive patients undergoing free flap BR using internal mammary vessels as recipients were recruited. Patient and intraoperative factors as well as intraoperative measurements were recorded. A dynamic model was developed based on intraoperative parameters. For the pilot study, plastic and reconstructive surgery trainees were recruited to complete a hand-sewn internal mammary artery (IMA) anastomosis using the new simulator and completed objective questionnaires pre- and postsimulation. Subjective feedback was recorded and themes determined. Results Fifteen operative sites were analyzed. Flap pocket was found to be between 4 and 5 cm in depth with vertical excursion of 3.7 ± 1.0mm and a respiratory rate of 9 to 14 breaths/minute. Previous radiation, rib space, body mass index (BMI), blood pressure, heart rate, tidal volume, and respiratory rate showed no correlation to vessel depth/excursion. Laterality, rib space, BMI, radiation, vitals, and tidal volume had no correlation with vessel movement. Twenty-two trainees were included in the pilot. An increase in confidence and mixed results for anxiety was reported. Conclusion This study reports a novel microsurgical simulation model that provides a realistic deep inferior epigastric perforator free flap BR IMA anastomosis experience. It replicates movement of vessels in situ with real-time respiratory excursion and similar physical structures of the internal mammary system. This model shows promising results for increased use in microsurgical education. [ABSTRACT FROM AUTHOR]

Polyethylene materials are of great interest to be used in many applications due to their many advantageous characteristics. It is light, highly chemical resistant, easy to process, low in cost and has good mechanical properties. Polyethylene is widely used as a cable-insulating material. However, research is still needed to further improve its insulation quality and properties. In this study, an experimental and alternative approach through a dynamic modeling method was conducted. The main objective was to investigate the effect of modified organoclay concentration on the properties of polyethylene/organoclay nanocomposites by observing their characterization and optical and mechanical properties. The thermogram curve reveals that 2 wt% organoclay used has the highest crystallinity (46.7%) while the highest amount of organoclay used produced the lowest crystallinity (31.2%). The presence of cracks was also observed mostly in the nanocomposite with higher content of organoclay, usually where 2.0 wt% and above of organoclay was used. Morphological observation from simulation results supports the experimental work. Only small pores were observed to form in lower concentrations, and as the concentration was increased to 2.0 wt% and above, the pores present became larger in size. Increasing the concentration of organoclay up to 2.0 wt% reduced the interfacial tension while increasing the concentration above 2.0 wt% did not bring any changes to the interfacial tension value. Different formulations produced different behavior of nanocomposite. Hence the control of the formulation was important to control the final result of the products for appropriate application in different sectors of industry. [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]

The use of surrogate models for forecasting dynamic behaviors of processes is a promising approach for optimizing process operation and control. This study aims to utilize the powerful prediction capabilities of deep learning-based dynamic surrogate models (DSMs) for fault detection in non-stationary processes, taking into account the impact of control actions on faults. A novel control-aware fault detection approach, utilizing data-driven dynamic surrogate modeling of closed-loop controlled processes, is proposed to detect potential faults under various control actions and operating conditions. DSMs for both one-step and multi-step ahead prediction are developed and combined to detect various types of faults, based on predictions and residuals while considering control effects. High-fidelity dynamic simulations are used to build first principles-based closed-loop process models and generate data under various operating conditions to train the DSMs. Deep learning methods such as long short-term memory and gated recurrent units are employed for dynamic surrogate modeling, and their performance is compared to select the optimal method. The proposed approach is demonstrated through two case studies using a continuous stirred tank reactor and a distillation column with an advanced control structure. The results consistently demonstrate that the approach can achieve both accurate fault detection and reliable false alarm avoidance under different dynamic operating conditions and faulty situations with varying severities and fault types. [ABSTRACT FROM AUTHOR]

Lamellar settlers are widely used in solid separation due to their relative high surface area paired with a small tank volume. Settlers exposed to high load variations may change their settling properties based on the variation of the flow pattern. Applying the critical point theory and coherent structure concept, a flow topology analysis was performed with the help of computational fluid dynamic simulations. The compartments were determined by the fluid flow, and the dynamic behavior of the compartments was taken into account. Under normal diurnal load variation, the architecture of the compartments did not change, in contrast to the mass transport between the zones, whereas the sludge removal process made significant changes in the architecture. The results showed two main flow zones with significant internal recirculation in the first zone. The hydraulic surface loading was examined in each zone, and the study revealed that the actual hydraulic load could be from 1.5 to 4.5 times much higher than that in individual zones due to recirculation eddies in the reactor tanks. The design hydraulic loading rate did not consider the local flow pattern. The discrete phase model approximation provided acceptable results, and the extent of the recirculation zone changed stepwise with different loads. [ABSTRACT FROM AUTHOR]

A biogas plant is fed with agricultural substrates at an average organic loading rate of 6 kgVS per m3 fermenter volume per day and substrates with relatively high nitrogen content. This situation results in a below‐average methane yield, so the aim is to increase the substrate efficiency. An analysis of the actual condition of the plant was performed and compared with reference values. A dynamic simulation model of the biogas plant was created and adjusted with data over an operating year. The model adjustment provided a good approximation of the simulation results to the key operating variables and thus allows the evaluation of different operating variations. The effect of various measures was analyzed by simulation and it showed a potential increase in substrate efficiency of up to 15 %. [ABSTRACT FROM AUTHOR]

In order to study the dynamic characteristics of the 660 MW ultra-supercritical circulating fluidized bed (CFB) boiler when the main fuel trip (MFT) and boiler trip (BT) are triggered, a dynamic simulation model of the 660 MW ultra-supercritical circulating fluidized bed boiler was established on the Apros simulation platform. The model dynamically simulated the MFT and BT processes at 100% BMCR, 75% THA, and 50% THA conditions, respectively. The steady-state simulation results showed a high accuracy compared with the designed parameters. The dynamic simulation results showed that after triggering the MFT and BT, owing to the huge thermal inertia, the bed temperature and steam temperature decreased lowly. For 100% BMCR and 75% THA conditions, the moisture separator always worked in dry state during the MFT and BT processes. For the 50% THA condition, the moisture separator quickly switched from dry to wet operation after the boiler triggers MFT and BT and gradually switched from wet to dry operation after MFT and BT were reset. [ABSTRACT FROM AUTHOR]

Objective: Excess salt consumption is causally linked with stomach cancer, and salt intake among adults in Vietnam is about twice the recommended levels. The aim of this study was to quantify the future burden of stomach cancer that could be avoided from population-wide salt reduction in Vietnam. Design: A dynamic simulation model was developed to quantify the impacts of achieving the 2018 National Vietnam Health Program (8 g/d by 2025 and 7 g/d by 2030) and the WHO (5 g/d) salt reduction policy targets. Data on salt consumption were obtained from the Vietnam 2015 WHO STEPS survey. Health outcomes were estimated over 6-year (2019–2025), 11-year (2019–2030) and lifetime horizons. We conducted one-way and probabilistic sensitivity analyses. Setting: Vietnam. Participants: All adults aged ≥ 25 years (61 million people, 48·4 % men) alive in 2019. Results: Achieving the 2025 and 2030 national salt targets could result in 3400 and 7200 fewer incident cases of stomach cancer, respectively, and avert 1900 and 4800 stomach cancer deaths, respectively. Achieving the WHO target by 2030 could prevent 8400 incident cases and 5900 deaths from stomach cancer. Over the lifespan, this translated to 344 660 (8 g/d), 411 060 (7 g/d) and 493 633 (5 g/d) health-adjusted life years gained, respectively. Conclusions: A sizeable burden of stomach cancer could be avoided, with gains in healthy life years if national and WHO salt targets were attained. Our findings provide impetus for policy makers in Vietnam and Asia to intensify salt reduction strategies to combat stomach cancer and mitigate pressure on the health systems. [ABSTRACT FROM AUTHOR]

Epoxy resins are formed when epoxy monomers react with crosslinkers that have active hydrogen sites on them such as amine and anhydrides. These cross-linked structures are highly unpredictable and depend on different parameters during curing. Epoxy material when reinforced with nanoparticles has got importance because of its extraordinary enhanced mechanical and thermal properties for structural application. Experimentally it is challenging to tailor these nanostructures and manufacture epoxy-based nanocomposites with desired properties. An experimental approach to preparing these is tedious and costly. The improvement of such materials requires huge experimentation and a better level of control of their properties can't be accomplished up till now. There is a need for numerical experimentation to guide these experimental procedures. With the headway of computational techniques, an alternative for these experiments had given an effective method to characterize these nanocomposites and study their reaction kinetics. Molecular dynamics (MD) simulation is one such technique that works on density function theory and Newton's second law to characterize these materials with different permutations and combinations during their curing. This review is carried out for MD simulation studies done to date on different epoxies and epoxy-based nanocomposites for their thermal, mechanical, and thermo-mechanical characterization. [ABSTRACT FROM AUTHOR]

A horizontal curve's geometric design is considered an important factor in highway accidents, and simple and spiral curves are regarded as the most common types of horizontal curves. Various factors affect the safety of horizontal curves, one of the most important of which is the side friction factor in the horizontal curves. Therefore, in this study, the safety of simple and spiral horizontal curves was investigated for the E-class sedan, E-class SUV, and two-axle conventional truck based on the side friction factor. In this regard, CarSim and TruckSim vehicle dynamic simulation software were utilized using 360 scenarios, including vehicle speed, vehicle type, curve radius, and road geometry. It was revealed that the maximum side friction factor for all vehicles in the simple horizontal curve was higher than the spiral horizontal curve. Also, the process of increasing the side friction factor was carried out with a gentler slope in the spiral horizontal curve. Except for the radius of 0.7 times the maximum radius of the spiral horizontal curve (R) for the truck and the radii of 0.7 R and 0.9 R for the sedan and SUV, the maximum side friction factor in simple and spiral horizontal curves was lower than the AASHTO recommended values, which shows that the spiral horizontal curve was better and safer compared to the simple horizontal curve based on the side friction factor. [ABSTRACT FROM AUTHOR]

The parallel expander ORC system is one of the solutions for providing an additional power output by improving the partial-load performance of an ORC. The parallel expander system corresponds to partial-load conditions by switching between various combinations of the expanders. During this process, the dynamic behavior occurs, which have not been characterized well in the open literature according to the best of the authors' knowledge. In this study, we developed a dynamic modeling of an ORC system using dual expanders (DE-ORC) to study the dynamic responses during its mode changes. System components were simulated using an open-source library of ThermoCycle written in Modelica language. For each component, empirical parameters were implemented based on the experimental results. Furthermore, during the mode change that involved going from dual expander mode to singular expander mode, and to prevent the formation of the droplet in the expanders, a control strategy was proposed and simulated. The strategy involved lowering of the mass flow rate and then shifting the mode. Several timings between flow rate lowering and shifting the mode were analyzed, and the optimum shifting time was found to be in between 40 to 50 s. [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]

Purpose: The authors present a dynamic macroeconomic model for assessment of disaster risk reduction (DRR) policies under multiple hazards. The model can be used to analyze and compare various potential policies in terms of their economic consequences. The decomposition of these effects into multiple benefits helps policy makers and other stakeholders better understand the ex ante and ex-post advantages of DRR investments. The purpose of this paper is to address these issues. Design/methodology/approach: A dynamic real business cycle model is at the core of this research. In the model multiple natural hazards modeled stochastically cause shocks to the economy. Economic outcomes, most importantly, output can be assessed before and after disasters and under various DRR policies. The decomposition of benefits aims to quantify the concept of triple dividends. Findings: In case study applications in Tanzania and Zambia, the authors find that investments into physical infrastructure and risk transfer instruments generate a variety of benefits even in the absence of disaster. A land use restriction with planned relocation for example reduces output in the short run but in the long run increases it. Overall, policy effects of various DRR interventions evolve in a nonmonotonic manner and should be evaluated over a long period of time using dynamic simulation. Originality/value: The novelty of this study lies in the economic quantification of multiple benefits described in the triple dividends literature. This helps comparing ex ante, ex-post and volatility-related economic effects of multiple disasters and related physical and financial DRR investment options. As observed in the case studies, the model can also identify overlooked temporal heterogeneity of co-benefits of DRR investments. [ABSTRACT FROM AUTHOR]

Here, we present an implicit-solvent model for dynamic simulations of hard-rod and rod-polymer suspensions. Individual rods are represented by a rigid linear chain consisting of overlapping spheres which interact through a pseudohard-core potential based on the cut-and-shifted Mie (generalized Lennard-Jones) potential with exponents (50, 49). In the rod-polymer suspensions, the polymers are modeled as freely interpenetrable spheres with respect to each other, while there is the pseudohard-core repulsion between the polymer and rod spheres. Dynamic simulations with this model are carried out with a dissipative particle dynamics (DPD) thermostat—each sphere is put in a larger DPD sphere and thus interacts with others via additional pairwise frictional and random forces—which captures the effects of Brownian forces due to the solvent while conserving local momentum. The phase behavior of these models, obtained from continuous compression and expansion simulations, reproduces previous predictions based on theoretical calculations and Monte Carlo simulations. Our method is suited to study dynamic processes in these suspensions, including nucleation and self-assembly, and can be readily extended to colloidal particles of different shapes and chemistry. [ABSTRACT FROM AUTHOR]

The article studies the possibility of using the LabVIEW programming environment to develop real-time dynamic models of continuous processes. The principle of data flow implemented in the LabVIEW environment makes it possible to abandon the direct solution of differential equations when developing a dynamic simulation of a technological object. It is proposed to present the simulation object as a set of dynamic elements, the main of which is the integrating element. The block diagrams of the proportional, integrating, inertial, and delay elements are given. The applicability of the LabVIEW platform for modeling continuous processes is demonstrated on the example of a simple heat exchanger model, which hydrodynamic flows structure corresponds to the ideal mixing model. The schematic and block diagrams of the developed model are given. In order to test the heat exchanger model, a numerical experiment was carried out in static and dynamic modes. The results of testing of the model confirmed its consistency, sensitivity and validity, which are signs of adequacy. [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]

Rectisol wash process(RWP) is a common process in coal chemical purification unit. However, the CO 2 product gas and tail gas in the RWP carries volatile organic methanol, which must be controlled to meet the environmental protection requirements. This work develops a steady and dynamic model for the process of water washing tower(WWT) by Aspen Plus, which is used in Rectisol wash tail gas treatment. The effects of the theoretical stage number(TSN) and desalting water flow rate(FR dw) of the washing tower on the methanol concentration in tail gas(c MET) are studied through sensitivity analysis. The optimized TSN and FR dw of WWT are 16 stages and 15 t/h, respectively. The c MET is 4.1 mg/Nm3 under the optimal condition. The internal structure of WWT is optimized. The design of the WWT is verified by the hydraulic results and dynamic process simulation. The results help to efficiently and conveniently implement the control of volatile organic methanol from RWP. [ABSTRACT FROM AUTHOR]

Flip-flow screen with crankshaft-link structure (FFSCLS) is effective for screening of high-water and fine materials. In this paper, a dynamic model governing the vibration and mechanical characteristics of the FFSCLS is proposed. In addition, the motion trajectory and vibration data of the FFSCLS were investigated by MATLAB/Simulink method. The results show that the MATLAB/Simulink method can fully describe the vibration characteristics of the FFSCLS with the maximum deviation within 6.71 % between experiment results. The mechanical characteristics of the FFSCLS were systematically studied by automatic dynamic simulation analysis using the ADMAS software. The MBD simulation results indicated that the resultant forces of the inner and outer screen boxes are always equal to 0. Moreover, the rotational speed of the crankshaft, the stiffness coefficient of the guild springs and rubber springs determined the mechanical characteristics of the flip-flow screen, and these parameters should be optimized. This work is helpful for the understanding of the combined effects of parameters and provides essential references for optimal design and efficient operation of a flip-flow screen with crank-link structure. [ABSTRACT FROM AUTHOR]