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The heterocharge accumulated in the oil‐paper insulation system of the converter transformer will enhance the local electric field and cause insulation deterioration. Numerical simulation is an effective method to analyze heterocharge. Currently, the numerical simulation of heterocharge is mainly based on the bipolar charge transport (BCT) model and the impurity ion transport (IIT) model. However, the effects of temperature, conductivity, and thickness of oil‐impregnated paper on charge transport have not been considered in these models. In view of this, a modified charge transport (MCT) model by introducing the Maxwell–Wagner model and heat conduction equation is proposed in this paper based on the BCT model and IIT model. Then, the influence of multi‐factors (temperature gradient, moisture content, and oil‐impregnated paper thickness) on heterocharge accumulation is investigated by using the MCT model. The simulation results obtained by the MCT model are more consistent with the experimental results than the BCT model, which proves the accuracy and superiority of the MCT model. Moreover, the increase in temperature gradient, moisture content, and oil‐impregnated paper thickness will enlarge the ion dissociation rate, conductivity, and trap density, and thus promote the generation of heterocharge. In that respect, the MCT model is expected to optimize the insulation design and provide a reference for space charge dynamic simulation. [ABSTRACT FROM AUTHOR]

In this paper, we propose a method of generating the elemental image array (EIA) for the integral imaging (InIm) based light field display (LFD). Firstly, we reveal the intrinsic voxel spatial distributions of the InIm‐based LFD and analyze how the voxel space affects the display performances such as spatial resolution, depth of field, and smoothness of parallax. Then, we present an algorithm to generate an EIA from a pair of RGB and depth (RGBD) images and an optimally selected voxel space. In the experiments, we tested the display performances of the voxels on different depth planes and obtained results consistent with the theoretical analyses. We also experimented with a computer 3D model and a real‐world scene on two InIm‐based LFD prototypes working in different modes, one in real mode and the other in virtual mode, and obtained favorable 3D display effects. The proposed method simplifies the light field data acquisition and image synthesis process, and supports handling both the virtual and the real‐world 3D scenes. We expect the proposed system to help the practical application of the InIm‐based LFD technology. [ABSTRACT FROM AUTHOR]

Cognitive modeling involves the creation of computer simulations that emulate the internal processes of the mind. This set of papers are the five best representatives of the papers presented at the 17th International Conference on Cognitive Modeling, ICCM 2019. While they represent a diversity of techniques and tasks, they all also share a striking similarity: They make strong statements about the importance of accounting for individual differences. [ABSTRACT FROM AUTHOR]

Paper-cut is one of the most characteristic Chinese folk arts, often used during festivals and celebrations. Chinese artists have used paper-cut to make animations. Typical paper-cut artwork is made with 2D illustrations on paper, and making many frames necessary for an entire animation can be tedious and expensive. We present a system that allows a designer to directly annotate a 3D model with paper-cut patterns, while still allowing for adding an artistic touch to the design. We have designed special motifs coupled with templates, resulting in a parameterized set of decorative paper-cut patterns which give the artist flexible control and allow editing of the pattern size, orientation, and shape. The artist chooses a pattern and places the pattern on the model in the desired position. The system determines actual surface coverage and trims the object's surface geometry to simulate the cut-out effect we observe in traditional 2D paper-cut art. We demonstrate that our system allows faster and easier addition of paper-cut decoration to 3D models compared to general purpose modeling tools, such as Maya. Animations made with the 3D paper-cut models escape from the limitations of traditional 2D paper-cut animation on the movement in perspective, furthermore, our system allows for easy pattern animations on 3D models, which is very powerful but hard to do with traditional paper-cut animation. Copyright © 2007 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Paper chromatography is a simple and harmless experiment suitable for lower secondary education. Besides the training of subject‐specific contents, paper chromatography allows the application of modelling and simulation since the submicroscopic processes can be simplified in a way that they become understandable in lower secondary education. Here, the application of digital tools in addition to the experimental performance of paper chromatography in a compulsory STEM course in grade 6 is reported. Following a series of experiments, chromatography is at first simulated by a board game and then by computer simulations. Such simulation program allows the variation of the parameters in order to explore the model and to introduce the particle concept of matter and molecular interactions. The implementation with a graphical programming environment such as Scratch also allows the programming by pupils in this age group. In this way, it is possible to introduce modelling and simulation in an early stage as important contributions to scientific work in natural sciences. [ABSTRACT FROM AUTHOR]

Although paper-based analysis is known for centuries, only during the last decade this simple substrate became an object of detailed microfluidic studies. In order to obtain optimum performance and separation of the analytes in a microfluidic channel, devices should be optimized, both in terms of architecture and paper properties. Enzyme immobilization methods can not only increase the storage stability but also have an impact on the flow in paper matrix, providing additional charges, and changing the porous structure of paper. Therefore it should be guaranteed that the method of choice will not obstruct the flux in the final device. Paper-based device proposed in this study was composed of a bioactive channel, Pt working electrode, pencil drawn pseudo-reference electrode, a buffer filled sponge providing the wicking solution and a stack of wicking pads to guarantee continuous flow. Based on our previous research we chose 4 methods of enzyme immobilization relying on different phenomena (adsorption, covalent linkage, layer-by-layer, capsules). Different channel architectures were also evaluated in order to achieve optimum time of the enzymatic reaction, separation of peaks and the time of measurement. Experimental results were compared with computer simulations. Final device could quantify glucose (2.0-10.0 mmol L−1) and uric acid (0.1-1.2 mmol L−1) in their clinical range with good repeatability. [ABSTRACT FROM AUTHOR]

ABSTRACT A pattern-switchable origami antenna is designed with paper using inkjet-printing technology. The proposed antenna can be switched between loop and dipole antenna modes by folding and unfolding the paper, respectively. Eutectic gallium-indium liquid metal is introduced in order to avoid cracks in the conductive ink when the paper is folded. The performance of the proposed antenna is demonstrated through simulation and measurement results. © 2016 Wiley Periodicals, Inc. Microwave Opt Technol Lett 58:668-672, 2016 [ABSTRACT FROM AUTHOR]

The gap between computational chemistry and parametric device simulations limits the potentially immense impact of computer models on OLED R&D. We present a review on a bottom‐up multiscale modeling approach to bridge this gap and systematically eliminate performance bottlenecks by virtual design. In several case studies we demonstrate how microscopic simulations can support experimental R&D by identifying fundamental reasons for performance bottlenecks, and by deriving strategies for their elimination. [ABSTRACT FROM AUTHOR]

We present a novel and effective method for modeling a developable surface to simulate paper bending in interactive and animation applications. The method exploits the representation of a developable surface as the envelope of rectifying planes of a curve in 3D, which is therefore necessarily a geodesic on the surface. We manipulate the geodesic to provide intuitive shape control for modeling paper bending. Our method ensures a natural continuous isometric deformation from a piece of bent paper to its flat state without any stretching. Test examples show that the new scheme is fast, accurate, and easy to use, thus providing an effective approach to interactive paper bending. We also show how to handle non-convex piecewise smooth developable surfaces. [ABSTRACT FROM AUTHOR]

The author presents comments on a paper on the use of machine learning to support the system dynamics method. Topics discussed include its interpretation of simulation models and explanation of policy analysis, and the emerging view whereby dynamic problems from endogenous feedback structures can be tackled via wider tools and methodological approaches. Also noted is the resulting potential for greater insights into the modelling process.

This study examined whether pilots operating a flight simulator completed digital or paper flight checklists more accurately after receiving postflight graphic and verbal feedback. The dependent variable was the number of checklist items completed correctly per flight. Following treatment, checklist completion with paper and digital checklists increased from 38% and 39%, respectively, to nearly 100% and remained close to 100% after feedback and praise for improvement were withdrawn. Performance was maintained at or near 100% during follow-up probes. [ABSTRACT FROM AUTHOR]

This paper studies the performance of radio assignment algorithms for portable access in cellular systems. Several channel access procedures are proposed and simulated using block oriented network simulator (BONeS) simulation of a model 36-port system. Simulation results exhibit that load-sharing system with LIBTA algorithm is better than directed retry system with the same algorithm by around 0.9 erlangs while better than quasi-fixed channel assignment (QFCA) system by around 2 erlangs if the grade of service (GOS) is constrained to less than 10 per cent. Plus, a hybrid time-slot selection procedure is proposed to enhance the system performance. It is observed that systems with hybrid time-slot selection perform better than those with LIBTA algorithm in GOS under heavy load. It is also observed that load sharing system with hybrid time-slot selection algorithm is better than directed retry system with the same algorithm by around 0.7 erlangs and better than QFCA system by around 2 erlangs. Copyright © 2001 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

A virtual manipulation system for origami (paper folding) is described. A piece of paper defined in a computer can be deformed interactively by picking and moving a corner vertex of a paper face on a graphic screen using a mouse. Three kinds of folding operations and a curving operation transform the paper into a three-dimensional figure made of flat or curved surfaces. The roundness of the curved surfaces is calculated in real-time by minimizing an elastic energy function. The simulated paper bas traditional Japanese decoration applied as a texture to give a more realistic appearance. It is rendered with shading in real-time. [ABSTRACT FROM AUTHOR]

In recent years, the finite-difference time-domain (FDTD) method has been used to simulate a wide range of frequency dependent media. The accuracy of these simulations often depends on how accurately the complex dielectric constant is simulated in the sampled time domain used by FDTD. This paper describes the process of modelling the complex dielectric constant as a digital filtering problem and uses Z transforms to convert the frequency domain expression to a sampled time domain expression. Copyright © 1999 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

This article presents a discussion on a study by Bradley Jones and Rachel T. Johnson on the use of Gaussian Process model in computer simulation research. The authors believe that the uncertainty intervals on unsampled points generated by using a plug-in approach from maximum likelihood estimates may be too short. Their own experiences confirm that computer models are widely used in many areas of science and engineering, and the need to understand the performance of such models is critical.

This article presents a discussion on a study by Bradley Jones and Rachel T. Johnson on the use of Gaussian Process model in computer simulation research. The authors believe that the researchers presented a useful survey of the design and analysis of Gaussian process models for computer experiments. They provide a methodology for extending the range of inquiry of computer experiments to include categorical factors.

Der vorliegende Aufsatz stellt ein Konzept für den Entwurf und die Herstellung von gefalteten schalenförmigen Tragstrukturen aus zementbasierten Verbundwerkstoffen vor, das in Anlehnung an die japanische Papierfaltkunst Origami entwickelt wurde. Die räumlichen Tragstrukturen werden durch Faltung von ebenen Elementen mit vorgegebenen Faltlinien hergestellt. Ziel ist die Entwicklung einer Entwurfs- und Herstellmethodik für dünnwandige Faltwerke mit einfachen oder doppelt gekrümmten Geometrien, die als segmentierbare Hüll- und Konstruktionselemente mit optimierten mechanischen Eigenschaften eingesetzt werden können. Wegen der hohen Variabilität der Formen und der großen Anzahl von Freiheitsgraden der Faltstrukturen ist eine Unterstützung mit numerischer Simulation in allen Phasen des Entwurfs und der Herstellung unabdingbar. Gegenüber der traditionellen Herstellung von Schalentragwerken mithilfe aufwendiger gekrümmter Schalungen verspricht die Methodik ein hohes Potenzial an Wirtschaftlichkeit. Insbesondere durch die Verwendung von modernen, zementbasierten Verbundwerkstoffen werden durch das Konzept neue Anwendungsfelder erschlossen, die sich durch geringen Materialverbrauch, einen hohen Ausnutzungsgrad des Werkstoffs sowie eine einfache systematische Herstellung auszeichnen. Oricrete - design and manufacturing methodology for folded plate structures made of novel cementitious composites The present paper shows an approach for the design and production of folded plate structures made out of novel cementious composite materials. The idea of the approach is derived from the Japanese art of paper folding, origami. The spatial structures are obtained by folding of planar elements provided with prescribed crease lines. The aim of the present work is the development of a design and manufacturing method for the production of free-form structural members with optimized mechanical properties applicable as façade and load bearing segments. Due to the high variability of forms and the large amount of degrees of freedom of the fold patterns, a support by numerical simulation in all phases of design and production is required. The method has a high potential to reduce the production costs compared to traditionally fabricated shell structures with complex curved formworks. New fields of application for cementious composite materials can be entered that are characterized by low material consumption, a high exploitation of the material and a systematic manufacturing process. [ABSTRACT FROM AUTHOR]

A passive, low‐cost, paper‐based intelligent reflecting surface (IRS) is designed to reflect a signal in a desired direction to overcome non‐line‐of‐sight scenarios in indoor environments. The IRS is fabricated using conductive silver ink printed on paper with a specific nanoparticle arrangement, yielding a cost‐effective paper‐based IRS that can easily be mass‐produced. Full‐wave numerical simulation results were consistent with measurement results, demonstrating the IRS's ability to reflect incident waves into a desired nonspecular direction based on the inkjet‐printed design and materials. [ABSTRACT FROM AUTHOR]

The author presents comments on an article on a simulation model on sustainable and healthy diets for decision makers in 2021. Topics discussed include meat and dairy alternatives and the possible extension of the model boundary and understanding of transition policies, the expected tripling of insect market volume in Europe by 2023, and the environmental impacts of fertilizers and declining groundwater levels. Also noted is a suggested bipartisan approach on the food and health system.

A new approach using FIT-formulation (Finite Integration Technique) (T. Weiland, Electron. Commun., 31, 116–120 (1977); Int. J. Numer. Model., 9, 295–319 (1996)) for simulating waveguide propagation of optical pulses is presented. FIT-methods are widespread in use for broadband linear simulations. In recent years, several attempts have been made to describe different dispersive material-characteristics such as Drude, Debye or Lorentz dispersion. Today advanced FDTD-formulations (Finite Difference Time Domain) also consider non-linear effects (P. M. Goorjian and A. Taflove, IEEE Opt. Lett., 17(3), 180–182 (1992); D. M. Sullivan, IEEE Trans. Microwave Theory Techniques, 43(3), 676–682 (1995)). In the following presented method third-order non-linear effects were described, which can be observed in isotropic media in frequency ranges of optical pulses, by updating material polarization terms using classical descriptions of Lorentz dispersion, Raman scattering and the Kerr effect. The basic idea is transforming these description formulas into sets of linear differential equations and solving them with the help of the general exponential solution. Copyright © 1999 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

The work is built on a previous research by Wiryana and Berg, in which wicking into four wet-formed paper stripes, consisting of cellulose fibers and four different percentages of the powdered carboxymethyl cellulose (CMC) superabsorbent, was studied experimentally. Because of the swelling of cellulose fibers and CMC powder on contact with water, the wicking was accompanied by a swelling of the matrix. A finite element/control volume (FE/CV)-based computer program is used for the first time to model the wicking in such swelling porous medium. The simulation used a novel form of continuity equation, which included the effects of liquid absorption and matrix swelling, in conjunction with the Darcy's law to model the single-phase flow behind a clearly defined liquid-front. A new method of estimating the time-varying permeability of the paper, based on the absorbed liquid-mass vs. time plots, is also proposed. Later, this time-dependent permeability is used in the numerical simulation to change the permeability in elements behind the moving liquid-front as a function of the time that the element has been wetted by the liquid, since the passage of the liquid-front. The numerical prediction of the wicking-front location as a function of time compares well with the reported experimental data. © 2011 American Institute of Chemical Engineers AIChE J, 58: 2536-2544, 2012 [ABSTRACT FROM AUTHOR]

This article presents a discussion on a study by Bradley Jones and Rachel T. Johnson on the use of Gaussian Process model in computer simulation research. The author believes that the researchers offer a clear and helpful introduction to ideas and methods used in the design and analysis of computer experiments. He provides some additional points of importance regarding analysis, design and computing.

This article presents a discussion on a study by Bradley Jones and Rachel T. Johnson on the use of Gaussian Process model in computer simulation research. The author believes that sometimes a computer simulation run is not expensive. He references a study that examined migration of radionuclides into ground water from a nuclear waste repository.

This article presents a discussion on a study by Bradley Jones and Rachel T. Johnson on the use of Gaussian Process model in computer simulation research. The author believes that the Gaussian process model often performs adequately apparent nonstationarity. He explores the topic of model calibration, the relationship between the design and the model used to fit the data, and design augmentation.

Signal‐to‐noise ratio and spatial resolution are quantitatively analysed in the context of in‐line (propagation based) X‐ray phase‐contrast imaging. It is known that free‐space propagation of a coherent X‐ray beam from the imaged object to the detector plane, followed by phase retrieval in accordance with Paganin's method, can increase the signal‐to‐noise in the resultant images without deteriorating the spatial resolution. This results in violation of the noise‐resolution uncertainty principle and demonstrates 'unreasonable' effectiveness of the method. On the other hand, when the process of free‐space propagation is performed in software, using the detected intensity distribution in the object plane, it cannot reproduce the same effectiveness, due to the amplification of photon shot noise. Here, it is shown that the performance of Paganin's method is determined by just two dimensionless parameters: the Fresnel number and the ratio of the real decrement to the imaginary part of the refractive index of the imaged object. The relevant theoretical analysis is performed first, followed by computer simulations and then by a brief test using experimental images collected at a synchrotron beamline. More extensive experimental tests will be presented in the second part of this paper. [ABSTRACT FROM AUTHOR]

Researchers have found that computer modeling fosters the learning of causal mechanisms in systems, an important crosscutting concept in science that many novice learners find challenging. Despite the research that highlights the role of teacher's instructional practices in enacting computer tools, few studies have considered teachers' use of computer modeling and its implications for student learning in classroom interactions, compared to interactions without computer tools. In this study, we examine (a) the impact of computer modeling on students' understanding of causal links in decomposition and (b) classroom interactions with use of computer modeling. We employed a quasi‐experimental design with eight middle school science classes that served predominately Latinx students. The random treatment was at the class level (computer modeling; n = 60, four classes) and control (paper modeling; n = 59, four classes). Analyses incorporated student preassessment and postassessment, classroom observations, and audio‐recorded modeling instruction. Results indicate that compared to paper modeling, computer modeling enriched systems thinking, particularly students' ability to provide causally coherent statements in explaining scientific ideas and evidence. Enactment of computer modeling may be associated with a shift in classroom interactions to include more invitation for students' elaboration of causal systems. We discuss aspects of computer modeling that may foster systems thinking, with implications for the future design of tools and curricula. [ABSTRACT FROM AUTHOR]

Key points The atrioventricular node (AVN) is a crucial component of the cardiac conduction system. Despite its pivotal role in regulating the transmission of electrical signals between atria and ventricles, a comprehensive understanding of the cellular electrophysiological mechanisms governing AVN function has remained elusive. This paper presents a detailed computational model of mouse AVN cell action potential (AP). Our model builds upon previous work and introduces several key refinements, including accurate representation of membrane currents and exchangers, calcium handling, cellular compartmentalization, dynamic update of intracellular ion concentrations, and calcium buffering. We recalibrated and validated the model against existing and unpublished experimental data. In control conditions, our model reproduces the AVN AP experimental features, (e.g. rate = 175 bpm, experimental range [121, 191] bpm). Notably, our study sheds light on the contribution of L‐type calcium currents, through both Cav1.2 and Cav1.3 channels, in AVN cells. The model replicates several experimental observations, including the cessation of firing upon block of Cav1.3 or INa,r current. If block induces a reduction in beating rate of 11%. In summary, this work presents a comprehensive computational model of mouse AVN cell AP, offering a valuable tool for investigating pacemaking mechanisms and simulating the impact of ionic current blockades. By integrating calcium handling and refining formulation of ionic currents, our model advances understanding of this critical component of the cardiac conduction system, providing a platform for future developments in cardiac electrophysiology. This paper introduces a comprehensive computational model of mouse atrioventricular node (AVN) cell action potentials (APs). Our model is based on the electrophysiological data from isolated mouse AVN cells and exhibits an action potential and calcium transient that closely match the experimental records. By simulating the effects of blocking specific ionic currents, the model effectively predicts the roles of L‐type Cav1.2 and Cav1.3 channels, T‐type calcium channels, sodium currents (TTX‐sensitive and TTX‐resistant), and the funny current (If) in AVN pacemaking. The study also emphasizes the significance of other ionic currents, including IKr, Ito, IKur, in regulating AP characteristics and cycle length in AVN cells. The model faithfully reproduces the rate dependence of action potentials under pacing, opening the possibility of use in impulse propagation models. The population‐of‐models approach showed the robustness of this new AP model in simulating a wide spectrum of cellular pacemaking in AVN. [ABSTRACT FROM AUTHOR]

This study investigates the effects of sea spray on extreme precipitation forecast in Beijing of China between 28 July and 2 August 2023 as a case test. In this case, fully coupled model increased upward moisture in the Bohai and Yellow Seas and increased accumulated rainfall by 21% in North China. For the extreme precipitation events with the 5‐day accumulated precipitation exceeding 500 mm, the atmosphere‐only model did not forecast the events; the coupled model without sea spray performed well with the 0.29 threat score (TS) and 88 mm root mean square error (RMSE); in the fully coupled model, the effects of sea spray increased atmospheric instability, which increased the precipitation around Beijing and yielded a more accurate forecast with the 0.37 TS and 65 mm RMSE. This paper suggests a scientific clue to improve numerical simulation for extreme rainfall events, however, more cases are still needed for statistical evaluation. Plain Language Summary: Although meteorological forecasting ability has been improved considerably during the past decades, precipitation during extreme events remains typically underestimated. Improving model accuracy for heavy rainfall events is, indeed, a ground challenge. In this study, we conducted three numerical experiments under different conditions to evaluate the effects of sea spray on extreme precipitation forecasts for the Beijing extreme rainfall event between 28 July and 2 August 2023. Our results indicated that for this 5‐day forecasting case, including sea spray in the simulations enhanced precipitation in North China by transporting more moisture from the Bohai and Yellow Seas upward into the atmosphere. The moister and warmer air caused by sea spray effects was transported to Beijing through northwestward wind and lifted by the local terrain, then caused a more unstable atmosphere and higher intensity of precipitation around Beijing. By using statistical indicators and setting different precipitation thresholds for this extreme rainfall case, we determined that in this case, the fully coupled model including sea spray yielded more accurate forecast. To statistically evaluate the effects of sea spray in extreme precipitation forecasts, more cases are still needed. Key Points: Fully coupled model led more upward moisture in the Bohai and Yellow Seas and increased 5‐day accumulated rainfall by 21% in North ChinaFully coupled model improved the forecasting threat score from 0 to 0.37 with the 5‐day accumulated precipitation exceeding 500 mmSea spray led to more unstable atmosphere for the Beijing extreme rainfall event, yielding a more accurate forecast [ABSTRACT FROM AUTHOR]

The semi‐underground double‐storey squat silo (SUDSSS) is a new type of silo with the advantages of preserving grain quality. In this paper, a numerical model of SUDSSS was constructed using solid elements. The proposed numerical model was validated by test results of an experimental underground silo, and the results demonstrated that: (1) Before and after backfilling, the radial and circumferential stress of the underground storey reached their maximum at 2/3 from the bottom and 2/3 from the ground surface, respectively; (2) As the height of grain storage increases, the silo wall stress in the overground storey increases. From the top of the underground storey up to 1/4 height of the overground storey, the stress of silo wall increases. (3) For the underground storey, the maximum stress occurs at 1/3 of the way from the apex of bottom cone. Practical applications: The semi‐underground double‐storey squat silo is a new grain storage device proposed by this paper, which consists of two layers. The lower layer is located in the ground and can utilize the shallow ground temperature to realize the green and low‐temperature storage of grain, the upper layer is conducive to the turnover of grain, which can ensure the quality of grain storage. The new silo has the advantages of saving land, energy saving and carbon reduction. Based on the silo, this paper investigates the stress–strain properties of the silo before and after soil backfilling during the construction stage, and obtains the change pattern of the static mechanical properties of the silo. This paper analyses the mechanical properties of semi‐underground double‐storey squat silo under different storage conditions at the grain storage stage, and studies the change patterns of the mechanical properties of the silo body under different storage heights. [ABSTRACT FROM AUTHOR]

The paper presents a study of the upstream influence of wind farms on the wind speed, which is called blockage effect. A Reynolds Averaged Navier–Stokes (RANS) numerical model using an actuator disc method was devised and validated using the SCADA data from a Horns Rev 1 wind farm. The maximum difference between the average power in the first row for SCADA and the numerical model was 7.8%. The model was used to determine the impact of blockage effect on the wind farm parameters and the extent to which the wind speed and the power generation were reduced. A reference wind farm was defined, with a modified size, spacing, turbine height, and diameter that were used for comparison with other wind farm configurations. The results of the investigation of the wind farm parameter effects on the upstream wind speed reduction are presented in the paper. It has been established that increasing the turbine spacing from 5D to 6.7D reduces the power loss due to blockage by two. Blockage losses are almost eliminated when the spacing is increased two times. Similarly, the wind turbine thrust coefficient (CT) has a large impact on blockage, which is more pronounced, when CT is higher. In fact, the velocity deficit due to blockage is proportional to CT. The turbine tower height has small impact on blockage effect—the power reduction was changed by 0.3% due to blockage for the investigated range. The number of turbines in a row (with a constant number of turbines in a row) does not affect blockage significantly. [ABSTRACT FROM AUTHOR]

This paper describes the main features and goals of the speculative work in modern sciences that has greatly accelerated since World War II due to the exponential increase in computing power and newly available theoretical and conceptual tools. It points to the long historical strand of speculative philosophical work in symbiosis with the sciences, suggests the reasons for its unexpected neglect in contemporary professional philosophy of science, why it should be a major approach, and why such pursuit is not inevitable. Finally, the paper outlines potential topics, fields, and tools for such collaborative work and argues it is likelier to be more fruitful today than at any point in the past hundred years. [ABSTRACT FROM AUTHOR]

In the era of document‐centric systems engineering, large organizations developing complex systems had practical methods of associating drawings, specifications, requirements and other information with each other. Mostly these evolved methods involved part numbers and drawing numbers, although sometimes the methods included mundane techniques such as storing drawings in specific drawers in specific filing cabinets. These manual methods were very labor intensive, did not handle changes gracefully, and were somewhat error prone. As computer software and modeling tools began to displace paper drawings and filing cabinets, a "connect and forget" style of linking evolved. We can see this sort of thinking in the relationships in UML and SysML, but also in other places such as the use of Universally unique identifiers (UUIDs) in the XMI file format underlying UML/SysML, the relationships in DOORS and related requirements tools, as well as the original architecture of OSLC which depended on URIs embedded in design artifacts to establish relationships. While these "click to connect" features provided increased convenience compared to the previous manual numbering approaches, these "hard‐coded" links have introduced a new set of problems. The root of most of the new problems comes in the difficulty of managing this sort of extremely large set of direct links as configuration items in their own right. In a larger system, this sort of link set quickly grows to thousands or even millions of links. Managing change, modularity, variants, subsystem reuse, and so on all become very difficult in the presence of such a large, unplanned, and uncontrolled link set. In this paper, we will review the different approaches to creating and managing such sets of links and provide a concise best practices recommendation for the configuration management of such sets of links. [ABSTRACT FROM AUTHOR]

This paper investigates the model performance of an industrial box used to remove ammonia from the air using a doped activated carbon. To this end, process models are developed and experimental measurements are carried out. The models are based on momentum and mass balance equations along with thermodynamic, hydrodynamic and adsorption kinetic relations. The measurements consist of pressure drops in the air purification box and breakthrough curves of ammonia on activated carbon. The models are implemented and solved using COMSOL Multiphysics®. Adsorption is investigated by means of a Fickian multi‐scale model, which demonstrated to efficiently predict the experimental data. The optimal values of the most estimable unknown parameters involved in each model, as well as their confidence intervals are determined from experimental measurements. The performance of the industrial air purification model is rigorously assessed using statistical criteria, including mean‐square error (RMSE = 0.0013) and Pearson correlation coefficient (r = 0.999). [ABSTRACT FROM AUTHOR]

This paper proposes a robust distributed observer for uncertain systems where some unknown, unstructured, and bounded uncertainties exist in system matrices. In distributed observer, each node includes an observer which directly estimates a part of the system states by its limited measurements and further, the estimation of other states indirectly obtains via exchanging information with neighbouring nodes. It is shown that whole states convergence achieves if the LTI system is observable as well as the network graph is strongly connected. Also, in the proposed distributed observer, by applying a new term in dynamic equation, the robust performance is achieved in dealing with uncertainties in system matrices. The observer gains synthesis is then formulated in terms of linear matrix inequalities. Finally, the simulation results are presented to illustrate the effectiveness of the proposed distributed observer to handle system uncertainties. [ABSTRACT FROM AUTHOR]

This paper explores the finite‐time stability of reaction–diffusion genetic regulatory networks with time‐varying mixed delays. These delays encompass discrete delays and distributed delays. Unlike many existing studies, this paper assumes that both types of delays are bounded and continuous, without requiring differentiability. Additionally, the analysis combines the inequality approach and comparison method, while neither a Lyapunov–Krasovskii functional is constructed nor the finite‐time stability theorem is involved. The finite‐time stability of the addressed networks is then ensured by several suitable algebraic criteria. Some extended results are deduced for networks without considering reaction–diffusion and distributed delays effects as special cases. Finally, the validness of the derived results is proved by numerical simulations. [ABSTRACT FROM AUTHOR]

To explore the independent influence of the main factors affecting heating on the radiant floor heating system, CFD was used to simulate the simplified multi‐storey multi‐family building model under different working conditions, and focusing on the calculation and comparative analysis of these four factors (heating supply, the location of room, outdoor temperature and the neighboring heating situation). The results showed that heating supply is the most important factor affecting indoor temperature, and the change of heating supply has the most obvious effect on the change of indoor temperature in the middle of the bottom layer, and the least effect on the edge of the top layer, which is a 1.6–1.7 times relationship. The influence of outdoor temperature on indoor temperature mainly depends on the area proportion of external envelope structure, and the changing rates of the indoor temperature of the edge of the top layer, the middle of the top layer, the edge of the bottom layer, the middle of the bottom layer with the outdoor temperature are 0.94, 0.93, 0.88, and 0.86. The influence of the neighboring heating situation on indoor temperature mainly depends on the surface area proportion of inner envelope structure, and the proportion of heat gain (dissipation) of each envelope to the total heat supply is basically the same, the heat dispersed through the north wall, south wall, east wall and west wall of the room at the middle of the bottom layer account for about 34%, 37%, 9%, and 9% respectively. [ABSTRACT FROM AUTHOR]

Based on a single‐phase cascaded H‐bridge (CHB) multilevel converter, this paper investigates a control strategy combining power estimation and natural frame control (NFC) with the omission of grid voltage sensors. Besides, this control method, without phase‐locked loop (PLL), can meet the continuous operation of the system and also eliminates grid voltage feedforward. First, natural frame control is introduced to derive the implementation process of control strategy without PLL, and the calculation formula of AC reference currents is given. Furthermore, the separate control of active and reactive currents is achieved. Second, the principle of proposed control algorithm is presented, and the sinusoidal voltage unit vector for synchronization can be accurately estimated. Next, considering the errors, the article corrects the method through parameter compensation. In addition, the balanced control method stabilized the DC side voltage of the converter. Finally, the effectiveness of this method is verified by computer simulation and experimental prototype. [ABSTRACT FROM AUTHOR]

In theoretical analyses of early mother–child interaction, it has been argued that interaction should be studied in its flow over time, and that the behaviour of each interactant is likely to be non-linearly determined. The mother–child dyad can be seen as a non-linear dynamic system, the development of which is determined by the mutual relations between its elements. The present study is based on the idea that computer simulations can be used to find out what kind of empirical implication these ideas have. Accordingly, we describe two non-linear dynamic systems-based models for simulating mother–child interaction, i.e. a connectionist network model and a logistic growth model. Three determinants of the nature of the interaction, i.e. the child's irritability, the mother's sensitive responsiveness, and the intensity of an external stressor bothering the child, are varied systematically. Although the results of both simulations differed considerably, they shared the fact that small changes in stressor intensity produced abrupt changes from one type of interaction to another. In addition, increasing stressor intensity sometimes had the paradoxical effect of resulting in less, rather than more, distress on the side of the child. Though irritability and responsiveness were varied in a less fine-grained way than stressor intensity, the results suggest that similarly small differences in these dimensions at different parts of the dimension's scale range have differentially strong effects on the nature of the interaction. It is concluded that these simulations help us to specify the nature of empirically researchable phenomena that are to be expected, given the assumptions listed above. Further elaboration of the models and comparison with longitudinal empirical data is needed to answer further theoretical and practical questions. Copyright © 2000 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

This paper proposes a novel primary frequency regulation (PFR) scheme for multi‐infeed high voltage direct current (HVDC) (MIDC) system. First, a dynamic model for frequency response in the MIDC system is carried out to involve line‐commutated‐coveter (LCC)‐HVDCs in frequency regulation. Then, a disturbance observer (DO) is proposed to estimate both the power imbalance and the full order states of the system. By combining a Kalman filter, this DO gets an accurate estimation quickly with local frequency measurement. On the basis of the estimated disturbance and state variables, feedforward control schemes can be concluded to fully utilize the fast adjustability of LCC‐HVDCs. In this paper, a model predictive control based scheme is designed to coordinate LCC‐HVDCs under constraints of HVDC capacity and frequency boundaries. As a result, the optimal power‐sharing property of LCC‐HVDCs is achieved to enhance the PFR dynamic performance of the AC main system. Further, the stability of the proposed method is analysed using the Lyapunov method. Finally, numerical simulations are concluded to verify the effectiveness and the merits of the proposed method, by comparing it to typical droop controls. [ABSTRACT FROM AUTHOR]

This paper focuses on a class of exponential stability control problem for the stochastic neural networks (SNNs) with time‐varying delays and Markov jump (TVDMJ). As a prerequisite to the main theorem, the existence and uniqueness of the solution for the main system are proved via contraction map principle. For the stability control of the system, we design a controller Ct,xtδδ,m(t)$$ C\left(t,x\left(\left[\frac{t}{\delta}\right]\delta \right),m(t)\right) $$ which can be adjusted the parameters δ$$ \delta $$ to make the system stabilization. We use this controller to actively control the stability behavior of the system, rather than the papers by setting the appropriate parameters to make the system achieve a stable state. Based on the intermittent control, we design a novel trajectory similarity process control and obtain exponential stability results, which are less conservative than the existing theoretical results. Two examples based on some numerical calculation and simulation diagrams are presented to validate the effectiveness for the utilized techniques. [ABSTRACT FROM AUTHOR]

Background: The potential of learning analytics dashboards in virtual reality simulation‐based training environments to influence occupational self‐efficacy via self‐reflection phase processes in the Chemical industry is still not fully understood. Learning analytics dashboards provide feedback on learner performance and offer points of comparison (i.e., comparison with one's own past performance or comparison with peer performance) to help learners make sense of their feedback. Objectives: We present a theoretical framework for describing learning analytics reference frames and investigate the impact of feedback delivered through dashboards with different reference frames on occupational self‐efficacy, while controlling for workplace self‐reflection. Methods: This experimental study engaged 42 chemical operator employees, aged between 18 and 55 years, each with at least one year of experience. We utilised a two‐group design to ask two research question each with three competing hypotheses related to changes in occupational self‐efficacy, employing Bayesian informative hypothesis evaluation. Results and Conclusions: Results for the primary research question suggest that dashboards with progress reference frames do not elicit greater change to self‐efficacy than those with social reference frames, however, they may elicit equal change. Furthermore, dashboards with social reference frames may elicit greater change to self‐efficacy than those with progress reference frames. Exploratory results found that dashboards with progress reference frames may elicit greater positive directional change than those with social reference frames and that they may elicit equal directional change. These findings contribute to the understanding of self‐efficacy beliefs within the Chemical industry, with potential impacts on skill development. The research may inform the design of targeted interventions and training programs to influence self‐efficacy. From a practical perspective, this research suggests that careful consideration is needed when choosing reference frames in learning analytics dashboards due to their potential consequences on the formation of learner self‐efficacy. Lay Description: What is already known about this topic?: Learning analytics dashboards often aim to stimulate self‐regulated learning by providing feedback.Feedback plays a crucial role in simulation‐based learning and learning analytics dashboards can be a valuable tool to deliver feedback and facilitate the learning process by providing learners with insights into their performance and progress.Previous research has highlighted the importance of reference frames as critical design features of learning analytics dashboards, as they assist learners in making sense of learning analytics feedback.Self‐efficacy is a powerful determine factor of workplace performance and is influenced by mastery experiences and social modelling information. What the paper adds?: A theoretical framework describes the mediating role self‐reflection phase processes of the self‐regulated learning cycle plays in the formation of occupational self‐efficacy.This paper introduces the concept of three learning analytics reference frame components which include the performance outcome component, point of comparison component and score delta component.The paper indicates that learning analytics dashboards designed with a progress reference frame does not elicit greater change to occupational self‐efficacy than the social reference frame.Exploratory results suggest dashboards with progress reference frames might produce greater positive directional change compared to social reference frames or elicit equal change. Implications for practice?: Learning analytics system designers who use reference frames to help learners make sense of their feedback should carefully consider which reference frames they use as these decisions likely have consequences on the formation of learner self‐efficacy beliefs.For LAD designers and stakeholders, recognising the absolute change and directional shift in self‐efficacy is crucial, as LAD designs significantly influence these dynamics and guide the tailoring of effective tools.In industries like the chemical sector, where overconfidence can result in severe consequences, understanding the nuance of self‐efficacy changes is especially pertinent. [ABSTRACT FROM AUTHOR]

In this paper, the concept of crossed foldable display module is proposed as follows: there are two foldable axes, and the two foldable axes intersect vertically. In order to realize the crossed foldable display, it needs to be designed in terms of modules, hinges and so on, especially the module support layer in the intersection area. In this paper, the steps of structural design, numerical simulation and sample verification are used to obtain two kinds of support layers suitable for crossed foldable modules, which can be folded hundreds of thousands of times without failure in the whole module test verification, providing a new form for flexible display. [ABSTRACT FROM AUTHOR]

Four‐Wave Mixing (FWM) is one of the non‐linear phenomena affecting long‐reach communication systems and high bandwidth. Research communities use simulation tools for parameter optimization. Unfortunately, such a simulation is time‐consuming and requires more time as the number of channels increases. This paper proposes two fast implementations of Dense Wavelength Division Multiplexing (DWDM) system, limited by FWM and the intrinsic Amplified Spontaneous Emission (ASE) noise of optical amplifiers employed in each segment. Additionally, this work compares the efficiency and speed improvement of the proposed parallelization model versus an earlier sequential model. We present the computational complexity analysis of sequential and parallel models. The paper considers two different parallel implementations: a multicore processor using Open MultiProcessing (OpenMP) and Compute Unified Device Architecture (CUDA), which is based on the use of a Graphics Processing Unit (GPU). Results show that parallelism using CUDA improves by up to 70 times the simulation performance compared to the sequential model. Parallelism with CUDA is up to 15 times compared to OpenMP using 12 logical processors. It is possible to simulate an increased number of channels within our parallel execution, which was impractical in the sequential simulation. [ABSTRACT FROM AUTHOR]

This work addresses the ongoing challenge of optimizing sand control screens, attributed to a limited understanding of screen blocking. A novel one‐way computational fluid dynamics and discrete element method (CFD–DEM) coupling technique is presented to analyze the structural parameters of unconsolidated prepacked gravel screens (PPGS). CFD–DEM involves systematically investigating the width of the punched slot on the outer protective screen, the size of the gravel, and the efficiency of gravel packing to improve the antiblocking capability of unconsolidated PPGS. Results from numerical simulations reveal that under conditions of effective sand control, the amount of sand entering the gravel layer to the bridge (referred to as the sand pass rate) is positively correlated with the antilocking ability (referred to as oil productivity index) for unconsolidated PPGS. The efficiency of gravel packing has the most substantial effect on the antilocking performance of unconsolidated PPGS. The data suggest that appropriately reducing the efficiency of gravel packing can enhance the antilocking capability of unconsolidated PPGS. To design an unconsolidated PPGS with enhanced antilocking capability, the efficiency of gravel packing be determined first. Then, the gravel size is designed based on this efficiency, and the width relative to the gravel size is decided. This contemporary design principle diverges considerably from previous design principles for gravel‐packed sand control screens. Supporting validation experiments agree with simulation outcomes, suggesting the established one‐way CFD–DEM coupling method in this paper is suitable for analyzing the plugging mechanism of unconsolidated PPGS. Thus, the CFD–DEM coupling method improves the design of such screens for improved antiblocking performance. [ABSTRACT FROM AUTHOR]

The first Joint Workshop on Representation Uncertainty in the Earth Sciences was held in March 2021. This brought together the Earth observation, data assimilation and forecast verification and post‐processing communities, alongside metrologists to discuss the definition and quantification of representation uncertainty within the Earth sciences. The aim of the workshop was to facilitate cross‐disciplinary discussion, establishing where existing methodologies could be shared and to foster future collaboration. A key outcome of the workshop was a working definition of representation uncertainty applicable across all the Earth science communities, which is presented in this white paper. The cross‐disciplinary discussions at the workshop highlighted the need for scientists to work with metrologists to establish a common vocabulary for uncertainties, accessible to Earth science applications. Further recommendations included regular workshops to discuss progress in defining and quantifying representation uncertainty and awareness of cross‐disciplinary funding opportunities to further address representation uncertainty issues. Plain Language Summary: This paper describes a workshop which brought together experts from different Earth science disciplines to discuss and attempt to define the term "representation uncertainty". We make observations of the Earth using satellites, ground based instruments (such as weather stations), air and sea‐borne sensors. These observations are used in their own right, and also by computer models to generate weather forecasts. The observations themselves are imperfect and we quantify these imperfections using the term "uncertainty". In this paper we discuss the uncertainty that occurs when we compare two different sets of observations, two different models, observations and models, or where there are differences in underlying assumptions. As well as the uncertainties inherent in models and observations, there is also an uncertainty due to the fact that the two things being compared are not representing a phenomenon in exactly the same way. For example, a satellite observation may represent an average value over a few hundred square meters, while an instrument on the surface measures only at a single point (typically one‐square‐meter or less), and the model represents an area of several square kilometres. Understanding those differences is essential to be able to properly combine different sets of observations, and observations with models. Key Points: Representation uncertainty can be defined as occurring at a comparison interface between two quantitiesA common definition of representation uncertainty can be applied across the Earth Science communityCollaboration between scientists and metrologists is recommended to define an accessible and relevant vocabulary for uncertainty analysis [ABSTRACT FROM AUTHOR]

The paper describes how the calculation of diffuse scattering from atomistic model crystals has developed over the last approximately 50 years. Not only has the quality of observed diffuse X‐ray scattering data improved immensely with the advent of electronic area detectors and synchrotron radiation but the enormous increase in computer power has enabled patterns, of comparable quality to the observations, to be calculated from a Monte Carlo model. [ABSTRACT FROM AUTHOR]

For the robot control problems, the input constraint is an issue that must be carefully considered. Considering the control inputs of the robots in the multi‐robot system are constrained by different saturations in reality, we address the cooperative circumnavigation control problem of multiple unicycle‐type robots with non‐identical and unknown input constraints in this paper. A distributed control law is designed to drive the robots constrained by different and unknown input saturations to achieve the cooperative circumnavigation around a moving target. The algorithm proposed in this paper largely reduces the requirement for the maneuverability of the robots to achieve the cooperative circumnavigation. As long as the robots owns the basic maneuverability of circumnavigating around the target, it is proved rigorously that the proposed control algorithm can achieve the desired cooperation circumnavigation of the multi‐robot system. The effectiveness of the proposed method is validated by a numerical simulation. [ABSTRACT FROM AUTHOR]

A three‐bladed, dual‐axis teetering hub (3T) has been developed and compared to a three‐bladed rigid hub (3R) using computer modeling. Both hubs were fitted to a hypothetical 5‐MW offshore wind turbine mounted on an offshore floating platform. Cyclic analysis showed the 3T hub significantly reduced the impact of wind shear on the blades and virtually eliminated the impact of both turbulence and wind shear on the main shaft bearing and yaw bearing. Lifetime fatigue studies for the two hubs were performed using a rainflow‐counting program at various levels of turbulence and wind shear. Studies showed the significant reductions in cyclic variation provided by the 3T hub resulted in significant reductions in lifetime fatigue in comparison to the 3R hub. Simulations with the 3T hub showed an increase in turbulence caused a very small increase in blade fatigue but no increase in fatigue for the main shaft bearing and yaw bearing. In contrast, fatigue studies with the 3R hub showed an increase in turbulence caused significant damage to the blades and a combined increase in turbulence and wind shear caused extremely significant damage to the blades. This paper introduces a recently patented hub design that is superior to the ball‐and‐socket design described in a prior paper by this author. [ABSTRACT FROM AUTHOR]

Abstract Progression of knowledge in operations management (OM) relies on researchers building and testing theories using data from practice. However, standalone empirical research designs have inherent limitations and may not adequately capture complex OM problems. This may result in researchers narrowing the scope of the problems that they create epistemological silos and study empirical elephants. In this introductory article to the special issue, we look at the ways simulation methods can augment and answer questions that are not addressed through traditional empirical methods. We offer a framework regarding how and when to use simulation methods for a given research objectives and design. We conclude by discussing the contingencies of using these methods as well as the role of reviewers and editors in evaluating papers that involve such methods. [ABSTRACT FROM AUTHOR]

By combining the filter circuit and boost circuit, the filter‐integrated three‐switch boost inverter (TSBI) is proposed in this paper. Different from the traditional boost inverter, TSBI achieves the boost function at the AC side, so the voltage stress on the switches is small. Through modelling and analysis, the boosting characteristics and filtering characteristics of the system are obtained. The proposed topology can significantly suppress the resonance spike and does not need to add additional filtering equipment, which can reduce the volume of equipment and system loss. In order to clearly illustrate the advantages and disadvantages of the proposed topology, this paper makes a detailed comparison with other types of inverters. Finally, the feasibility of the system is verified by experiment and simulation. [ABSTRACT FROM AUTHOR]