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In this paper, a reaction–diffusion model that incorporates both discrete memory delay and distributed competition delay is introduced, we primary focus on the stability and Hopf bifurcation of its internal equilibrium point. A general methodology for analyzing the characteristic equations of this kind of model is established. Theoretical findings reveal that the stability of the system is contingent upon the relationship between the memory diffusion coefficient d 2 and the free diffusion coefficient d 1 . In addition, we also find a sudden change in the number of pure imaginary eigenvalues from 0 to infinity. In order to study the properties of the bifurcations, we transformed the model into an equivalent system without any integral term and provided a new formula for calculating the normal form of Hopf bifurcation. In the numerical simulation section, we delineate the crossing curves within the dual-delay σ - τ plane that signify the occurrence of Hopf bifurcations in the system. These curves reveal the presence of periodic solutions with varying amplitudes, along with the intriguing phenomenon of stability switching. Furthermore, the model demonstrated a distinct dynamic behavior, diverging from that observed in models with discrete competitive delays, these results suggest that the disruptive impact of distributed delays on the stability of system is significantly less pronounced than that of discrete delays. [ABSTRACT FROM AUTHOR]

Purpose: Good initial fixation of glenoid component for reverse total shoulder arthroplasty (RTSA) relies on component placement and screw purchase in the scapula bone. This is especially difficult in an Asian population with small glenoid geometry. Optimal glenoid component roll angle and screw angulation to achieve the longest screws for best fixation has not been defined in the current literature. Methods: Computer 3D modelling of 133 scapulas with RTSA performed were analyzed to determine patient specific optimal glenoid roll angle (GRA) for the longest bi-cortical screws attainable. The cranial-caudal angle (CCA), anterior-posterior angle (APA) and lengths for the superior and inferior screws were measured. Validation testing using calculated average (CA) angles and rounded average (RA) angles to the nearest 5 degree were recomputed for each case to determine the bi-cortical screw lengths achievable. The CA and RA screw lengths were compared against patient specific modelling using paired-sample t-tests. Results: Average GRA was − 1.6°, almost perpendicular to the long axis of the glenoid and achieves an average bi-cortical screw length of 51.3 mm and 45.5 mm for the superior and inferior screws respectively. The CCA and APA were 9.1° cranial and 6.5° posterior for the superior screw and screw angulation of 11.2° caudal and 0.7° anterior for the inferior screw. Validation testing shows statistically shorter screw lengths in the CA and RA models compared to patient specific modelling (p < 0.01). Conclusion: Validation testing with average angles for GRA, CCA and APA demonstrates strong patient heterogeneity and anatomical variation. Despite this, screw lengths attainable in the RA group were > 38 mm with good safety profile. Surgeons may consider the additional use of navigation-assisted, or 3D printed patient specific instrumentation to optimize baseplate and screw configuration for RTSA. [ABSTRACT FROM AUTHOR]

We analyze travelling wave (TW) solutions for nonlinear systems consisting of an ODE coupled to a degenerate PDE with a diffusion coefficient that vanishes as the solution tends to zero and blows up as it approaches its maximum value. Stable TW solutions for such systems have previously been observed numerically as well as in biological experiments on the growth of cellulolytic biofilms. In this work, we provide an analytical justification for these observations and prove existence and stability results for TW solutions of such models. Using the TW ansatz and a first integral, the system is reduced to an autonomous dynamical system with two unknowns. Analysing the system in the corresponding phase–plane, the existence of a unique TW is shown, which possesses a sharp front and a diffusive tail, and is moving with a constant speed. The linear stability of the TW in two space dimensions is proven under suitable assumptions on the initial data. Finally, numerical simulations are presented that affirm the theoretical predictions on the existence, stability, and parametric dependence of the travelling waves. [ABSTRACT FROM AUTHOR]

Whilst adversarial training has been shown as a promising wisdom to promote model robustness in computer vision and machine learning, adversarially trained models often suffer from poor robust generalization on unseen adversarial examples. Namely, there still remains a big gap between the performance on training and test adversarial examples. In this paper, we propose to tackle this issue from a new perspective of the inter-feature relationship. Specifically, we aim to generate adversarial examples which maximize the loss function while maintaining the inter-feature relationship of natural data as well as penalizing the correlation distance between natural features and adversarial counterparts. As a key contribution, we prove that training with such examples while penalizing the distance between correlations can help promote both the generalization on natural and adversarial examples theoretically. We empirically validate our method through extensive experiments over different vision datasets (CIFAR-10, CIFAR-100, and SVHN), against several competitive methods. Our method substantially outperforms the baseline adversarial training by a large margin, especially for PGD20 on CIFAR-10, CIFAR-100, and SVHN with around 20%, 15% and 29% improvements. [ABSTRACT FROM AUTHOR]

Aortic dissection is a life-threatening disease that consists in the development of a tear in the wall of the aorta. The initial tear propagates as a discontinuity leading to separation within the aortic wall, which can result in the creation of a so-called false lumen. A fatal threat occurs if the rupture extends through the whole thickness of the aortic wall, as blood may then leak. It is generally accepted that the dissection, which can sometime extend along the entire length of the aorta, propagates via a delamination mechanism. The aim of the present paper is to provide experimentally validated parameters of a mathematical model for the description of the wall's cohesion. A model of the peeling experiment was built in Abaqus. The delamination interface was described by a piecewise linear traction-separation law. The bulk behavior of the aorta was assumed to be nonlinearly elastic, anisotropic, and incompressible. Our simulations resulted in estimates of the material parameters for the traction-separation law of the human descending thoracic aorta, which were obtained by minimizing the differences between the FEM predictions and the delamination force given by the regression of the peeling experiments. The results show that the stress at damage initiation, Tc, should be understood as an age-dependent quantity, and under the assumptions of our model this dependence can be expressed by linear regression as Tc = − 13.03·10−4·Age + 0.2485 if the crack front advances in the axial direction, and Tc = − 7.58·10−4·Age + 0.1897 if the crack front advances in the direction of the aortic circumference (Tc [MPa], Age [years]). Other model parameters were the stiffness K and the separation at failure, δf–δc (K = 0.5 MPa/mm, δf–δc = 0.1 mm). The material parameters provided by our study can be used in numerical simulations of the biomechanics of dissection propagation through the aorta especially when age-associated phenomena are studied. [ABSTRACT FROM AUTHOR]

Idealized numerical simulations have been carried out to reveal the complexity in the development of asymmetric convection in a tropical cyclone (TC) under the influence of an environment with either uniform flow, vertical wind shear (VWS), or both. Results show that rainwater is enhanced to the right of the motion in the outer rainband, but such enhancement occurs in the upshear-left area of the inner-core region. Additionally, due to the asymmetries introduced by environmental flow, wavenumber-1 temperature and height anomalies develop at a radius of ~1000 km in the upper levels. A sub-vortex aside from the TC center encompassing the wavenumber-1 warm center appears, and asymmetric horizontal winds emerge, which, in turn, changes the storm-scale (within 400 km) VWS. Deep convection in the inner core closely follows the changing storm-scale VWS when its magnitude is larger than 2 m s–1 and is located downshear of the storm-scale VWS in all the experiments with environmental flow. In the outer rainbands, the maximum boundary layer convergence is mainly controlled by the direction of motion and is located in the rear-right quadrant. These results extend upon the findings of previous studies in three aspects: (1) The discovery of the roughly linear combination effect from the uniform flow and large-scale VWS; (2) The development of upper-level asymmetric winds on a 1000-km scale through the interaction between the TC vortex and environmental flow, resulting in changes in the storm-scale VWS pattern within the TC area; (3) The revelation that TC asymmetric convection closely aligns with the direction-varying storm-scale VWS instead of the initially designated VWS. [ABSTRACT FROM AUTHOR]

Low-angle straight tooth face gear transmission has significant advantages such as compact structure, small axial force, good shunt effect, and insensitivity to installation errors, demonstrating great superiority in the main reduction and torque distribution structure of helicopters. In this paper, the calculation of cutting force in the process of gear turning is studied, and the mathematical model of low-angle straight tooth face gear is established, and the numerical calculation and simulation analysis of cutting force are completed. On this basis, the gear machining test was completed on the gear machine, and the actual cutting force was collected, which verified the correctness of the cutting force calculation method and the feasibility of the cutting force optimization scheme, and provided a new solution for the cutting force calculation of the low-angle straight tooth face gear machining in industrial production. [ABSTRACT FROM AUTHOR]

We present a novel design methodology for a fractional model error compensator (FMEC) that addresses the challenge of model errors in fractional dynamical systems with polytopic uncertainty and disturbances. The FMEC can effectively compensate for model errors, thereby enhancing the performance of control systems. This approach leverages a combination of H ∞ -norm criteria and the Particle Swarm Optimization (PSO) algorithm to optimize the compensator design. The methodology integrates H ∞ -norm criteria for robust performance evaluation and PSO for optimization. The proposed FMEC design is validated through numerical simulations conducted on a fractional dynamical system. These simulations demonstrate that the design successfully compensates for model errors and improves the overall performance of the control system. This study offers a practical solution for designing robust FMECs applicable in various engineering fields, particularly for systems susceptible to polytopic uncertainty and disturbances. [ABSTRACT FROM AUTHOR]

Purpose: To characterize the 3D geometry of the distal tibia resection area from healthy individuals using CT-based digital implantation for proper preoperative sizing of TAA tibia component placement. Methods: Standardized CT images of healthy ankle joints serving as intra-individual references for treatment of contralateral injuries were identified. The tibial cross section dedicated to virtually host the tibial component was digitally prepared, and the size of the virtual contact surface was calculated. Finally, out of five prototypes the one fitting best in terms of size and alignment was identified. Results: CT scans taken from 319 subjects were used for the virtual implantation procedure. Body height and size of the distal tibia contact area correlated (r = 0.49 and 0.42 in females and males, each p < 0.001). Prosthesis sizes 2 and 3 fit well for the vast majority of patients, while the smallest and largest sizes are rarely required. Conclusions: Digital implantation of the tibial component should be considered a valuable tool for preoperative planning as well as for the development of new implant types. [ABSTRACT FROM AUTHOR]

Computer model has been extensively adopted to overcome the time limitation of language evolution by transforming language theory into physical modelling mechanism, which helps to explore the general laws of evolution. In this paper, a model is designed to simulate the evolution process of languages in human settlements, with the associated network topology being lattice. The language of each node in the lattice will evolve gradually under the influence of its own fixed evolutionary direction and neighbours. According to the computational experiment results, it is discovered that the state points of languages always converge into several clusters during the evolution process, which gives us an insight into language evolution. [ABSTRACT FROM AUTHOR]

The dynamical probing and linear offset boosting of constants in Josephson junction (JJ) instigated by the Wien bridge oscillator (JJIWBO) are investigated in this paper. Via numerical simulations, the JJIWBO unveiled bistable periodic oscillations, bistable periodic doubling with an evolving path to bistable chaotic characteristics, monostable chaotic behaviours and monostable periodic characteristics. The numerical dynamics are realised by the microcontroller validation (MCV) scheme. Two constant parameters are introduced in the rate equations of JJIWBO to implement the linear offset boosting of constants based on the two voltage variables. It is demonstrated that the polarity of the chaotic voltage and phase difference signals can be flexibly changed by varying one of the two constant parameters which is different from zero and the other constant parameter is zero. When two constant parameters have the same value, the chaotic voltages and phase difference signals can switch between bipolar and unipolar signals flexibly by changing the unique constant parameter. [ABSTRACT FROM AUTHOR]

This article presents an analysis and control approach for a non-smooth air-gap permanent magnet synchronous motor (NSAG-PMSM) in the absence of external disturbances. The analytical study of NSAG-PMSM shows the existence of equilibrium points. Based on the Routh–Hurwitz criterion, the stability of the equilibrium points reveals the existence of transcritical bifurcation. NSAG-PMSM exhibits various dynamical behaviours, such as bistable chaos, periodic spiking oscillations, chaotic spiking characteristics, coexistence between periodic and chaotic behaviours and periodic evolution towards monostable chaos as system parameters change. The research uses microcontroller implementation to validate the dynamical characteristics observed during the numerical simulations of the NSAG-PMSM. The study of NSAG-PMSM proposes a strategy to mitigate chaos and stabilise the system using two simple controllers, with a comparative study presented using peak overshoot and settling time diagrams. By combining these different aspects, this article significantly contributes to the understanding of the operation in NSAG-PMSM, highlighting specific aspects related to the application of microcontroller techniques in the field of electrical engineering and solutions to chaos control. [ABSTRACT FROM AUTHOR]

In order to estimate the age, the work examined the probabilistic evolution of three young pairs of asteroids in close orbits: (87 887) 2000 SS286—(415 992) 2002 AT49, (320 025) 2007 DT76—(489 464) 2007 DP16, (21 436) Chaoyichi—(334 916) 2003 YK39. In the numerical simulation, along with gravitational disturbances, the Yarkovsky effect in the form of a secular drift of the orbital semimajor axis was taken into account. For each pair of asteroids, 25 evolution scenarios were considered, corresponding to different combinations of obliquities of the asteroids' rotation axes and, correspondingly, different drift rates of the semimajor axes due to the Yarkovsky effect. For each asteroid, 1000 clones were generated. Age estimates were obtained based on analysis of moment distributions: (1) low relative-velocity close encounters of asteroids of pair to distances on the order of the Hill sphere at a relative speed of several units of the escape velocity and (2) achievement of minimum values of the Kholshevnikov metric, which characterizes the distance between orbits. The following age estimates for young asteroid pairs were obtained: (87 887) 2000 SS286 and (415 992) 2002 AT49 from 7.58 ± 0.04 to 8.80 ± 0.04 kyr; (320 025) 2007 DT76 and (489464) 2007 DP16 from 15.5 ± 1.0 to 58.6 ± 16.0 kyr; (21 436) Chaoyichi and (334 916) 2003 YK39 from 32.3 ± 0.1 to 102.6 ± 0.7 kyr. [ABSTRACT FROM AUTHOR]

The mechanism of cytoplasmic incompatibility (CI) is important in the study of Wolbachia invasion in wild mosquitoes. Su et al. (Bull Math Biol 84(9):95, 2022) proposed a delay differential equation model by relating the CI effect to maturation delay. In this paper, we investigate the dynamics of this model by allowing the same density-dependent death rate and distinct density-independent death rates. Through analyzing the existence and stability of equilibria, we obtain the parameter conditions for Wolbachia successful invasion if the maternal transmission is perfect. While if the maternal transmission is imperfect, we give the ranges of parameters to ensure failure invasion, successful invasion and partially suppressing, respectively. Meanwhile, numerical simulations indicate that the system may exhibit monostable and bistable dynamics when parameters vary. Particularly, in the bistable situation an unstable separatrix, like a line, exists when choosing constant functions as initial values; and the maturation delay affects this separatrix in an interesting way. [ABSTRACT FROM AUTHOR]

In this paper we present a numerical scheme based on spectral collocation methods to investigate the flow of a piezo-viscous fluid, i.e., a fluid in which the rheological parameters depend on the pressure. In particular, we consider an incompressible Navier–Stokes fluid with pressure dependent viscosity flowing in: (i) a two-dimensional non-symmetric planar channel; (ii) a three-dimensional axisymmetric non-straight conduit. For both cases we impose the Navier slip boundary conditions that can be reduced to the classical no-slip condition for a proper choice of the slip parameter. We assume that the dependence of the viscosity on the pressure is of exponential type (Barus law), even though the model can be replaced by any other viscosity function. We write the mathematical problem (stress based formulation) and discretize the governing equations through a spectral collocation scheme. The advantage of this numerical procedure, which to the authors' knowledge has never been used before for this class of fluids, lies in in the ease of implementation and in the accuracy of the solution. To validate our model we compare the numerical solution with the one that can be obtained in the case of small aspect ratio, i.e., the leading order lubrication solution. We perform some numerical simulation to investigate the effects of the pressure-dependent viscosity on the flow. We consider different wall functions to gain insight also on the role played by the channel/duct geometry. In both cases (i), (ii) we find that the increase of the coefficient appearing in the viscosity function results in a global reduction of the flow, as physically expected. [ABSTRACT FROM AUTHOR]

Markov chains and Markov decision processes have been widely used to model the behavior of computer systems with probabilistic aspects. Numerical and iterative methods are commonly used to analyze these models. Many efforts have been made in recent decades to improve the efficiency of these numerical methods. In this paper, focusing on Markov models with non-sparse structure, a new set of heuristics is proposed for prioritizing model states with the aim of reducing the total computation time. In these heuristics, a set of simulation runs are used for statistical analysis of the effect of each state on the required values of the other states. Under this criterion, the priority of each state in updating its values is determined. The proposed heuristics provide a state ordering that improves the value propagation among the states. The proposed methods are also extended for very large models where disk-based techniques are required to analyze the models. Experimental results show that our proposed methods in this paper reduce the running times of the iterative methods for most cases of non-sparse models. [ABSTRACT FROM AUTHOR]

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In the process of continuous casting, the slab temperature is a particularly crucial production parameter. However, it is still being monitored on the surface of the slab. At present, the prediction of slab temperature using machine learning models is not feasible due to the lack of internal temperature data from actual production. In this paper, a prediction method based on DNNs algorithm integrating numerical simulation and SHAP analysis is proposed to monitor the temperature field of continuous casting slab in real-time. The dataset comprises 6 input features and 5 output features. Following data preprocessing, four distinct machine learning models were developed employing DNNs, SVM, XGBoost, RF algorithms to individually predict the temperature of the slab. The DNNs model is selected as the optimal model according to the performance comparison using performance parameters such as MAE, MSE, and R2. SHAP value is calculated for the sensitivity analysis of the influence of the characteristic parameters of DNNs prediction model on the prediction results. The experimental results indicate that the prediction model has an average success rate of 96.48 pct within a temperature accuracy of ± 20 °C. Moreover, the resident time, the amount of internal side water within the slab, and the internal side heat transfer coefficient of the slab have the most significant impact on the model. This study introduces a novel method for establishing machine learning models with machine learning techniques. [ABSTRACT FROM AUTHOR]

Purging plugs are commonly used in the secondary refining process, which determines the fluid hydrodynamics and refining effects of the ladle. This study proposes a blowing approach to enhance flow field disturbance and mass transfer. The experiment, designed to validate the numerical simulation, involved the use of UDF (user-defined function) to describe bubble expansion and the variation of gas blowing. The results indicated that the pulsed bottom blowing method was more effective in producing tiny bubbles. Owing to the smaller fluctuation amplitude for the pulsed bottom blowing, the energy dissipated by slag layer fluctuations decreases. Compared to the pulsed bottom blowing, the proportion of the slag eye area of the steady bottom blowing is 12 pct larger. Furthermore, the pulsed bottom blowing causes an intermittent flow field. This discontinuity stirring energy input is conducive to its transmission and dissipation. Besides, the mixing time of pulsed bottom blowing exceeds 5 pct larger than that of the steady bottom blowing. These findings have practical implications for enhancing the flow hydrodynamics of liquid steel and controlling bubble diameter by the purging plug within the pulsed bottom blowing in the ladle, which is also suitable for stirring reactors with gas blowing. [ABSTRACT FROM AUTHOR]

The Expectation Maximization (EM) algorithm is widely used in latent variable model inference. However, when data are distributed across various locations, directly applying the EM algorithm can often be impractical due to communication expenses and privacy considerations. To address these challenges, a communication-efficient distributed EM algorithm is proposed. Under mild conditions, the proposed estimator achieves the same mean squared error bound as the centralized estimator. Furthermore, the proposed method requires only one extra round of communication compared to the Average estimator. Numerical simulations and a real data example demonstrate that the proposed estimator significantly outperforms the Average estimator in terms of mean squared errors. [ABSTRACT FROM AUTHOR]

In Bonito (J. Comput. Phys. 448:110719, 2022), a local discontinous Galerkin method was proposed for approximating the large bending of prestrained plates, and in Bonito (IMA J. Numer. Anal. 43:627-662, 2023) the numerical properties of this method were explored. These works considered deformations driven predominantly by bending. Thus, a bending energy with a metric constraint was considered. We extend these results to the case of an energy with both a bending component and a nonconvex stretching component, and we also consider folding across a crease. The proposed discretization of this energy features a continuous finite element space, as well as the discrete Hessian used in Bonito (J. Comput. Phys. 448:110719, 2022; IMA J. Numer. Anal. 43:627-662, 2023). We establish the Γ -convergence of the discrete to the continuous energy and also present an energy-decreasing gradient flow for finding critical points of the discrete energy. Finally, we provide numerical simulations illustrating the convergence of minimizers and the capabilities of the model. [ABSTRACT FROM AUTHOR]

High entropy carbides (HECds) are multi-component carbides consisting of transition metal carbides. HECds are generally composed of five or more metal cations of the equal or near-equal substances, obtaining a single crystal structure. HECds have great potentials for future applications due to excellent mechanical, antioxidant and thermal properties. Due to their complex crystal structures and lattice distortion, computer simulations are widely used to efficiently associate the properties of HECds with the corresponding microstructures. In response to the development of HECds, this article provides an overview of the basic design, preparation process and properties of HECds. [ABSTRACT FROM AUTHOR]

One of the critical goals of teaching chemistry is to enable learners to gain conceptual understanding. Traditional instruction has often been associated with rote memorisation, resulting in learners failing to explain observed chemical phenomena, make predictions based on acquired concepts, advance convincing arguments, and engage in meaningful problem-solving and critical thinking. Therefore, the study aimed to describe the conceptual understanding of the learners taught Reaction Kinetics using computer simulations supported by the Predict-Observe-Explain strategy. The study was guided by Holme, Luxford, and Brandriet's five categories of conceptual understanding—transfer, translation, problem-solving, prediction, and depth as the conceptual framework. This was a descriptive study in which a case study research approach was used. Five purposively sampled grade 12 learners participated in the study, representing the range of cognitive abilities from a secondary school class of 53 learners. Semi-structured interviews were used to collect data. The responses of the five participants were analysed using the qualitative content analysis. The findings were that most of the learners' responses were in the sound understanding sub-category, some were in the partial understanding sub-category, and a few were in the no understanding sub-category, which made us conclude that computer simulations supported by the Predict-Observe-Explain strategy assisted the learners in conceptual understanding. The learners gained an understanding of most concepts, although their responses in the partial understanding sub-category showed difficulties related to depth, transfer, and translation. These findings are expected to assist chemistry teachers, teacher educators, and curriculum planners in improving learners' conceptual understanding of chemistry. [ABSTRACT FROM AUTHOR]

This paper presents a chaotic optimal thermodynamic evolutionary algorithm (COTEA) designed to address the integrated scheduling problems of berth allocation, ship unloader scheduling, and yard allocation at bulk cargo terminals. Our proposed COTEA introduces a thermal transition crossover method that effectively circumvents local optima in the scheduling solution process. Additionally, the method innovatively combines a good point set with chaotic dynamics within an integrated initialization framework, thereby cultivating a robust and exploratory initial population for the optimization algorithm. To further enhance the selection process, our paper proposes a refined parental selection protocol that employs a quantified hypervolume contribution metric to discern superior candidate solutions. Postevolution, our algorithm employs a Cauchy inverse cumulative distribution-based neighborhood search to effectively explore and enhance the solution spaces, significantly accelerating the convergence speed during the scheduling solution process. The proposed method is adept at achieving multiobjective optimization, simultaneously improving the service level and reducing costs for bulk cargo terminals, which in turn boosts their competitiveness. The effectiveness of our COTEA is demonstrated through extensive numerical simulations. [ABSTRACT FROM AUTHOR]

We tested re-optimisation strategies for international kidney exchange programmes using the simulator developed by the ENCKEP COST Action. Kidney exchange programmes (KEPs) are operating in most of the European countries to facilitate the exchange of kidney donors for the recipients with incompatible living donors. The optimal solutions for national and international KEPs are typically selected in every three months based on the compatibilities estimated on the individual immunological data. However, these estimations are not always accurate, and if a positive crossmatch is found in the laboratory crossmatch tests then the corresponding exchange cycle (or chain) must be cancelled. Depending on the matching process, the coordinators may use different re-optimisation strategies to repair the failed solutions. We examine the effects of using multiple rounds of re-optimisation with different optimisation strategies, such as fixing good cycles in the intermediate solutions or prioritising transplants with negative crossmatch tests in previous rounds. In the context of international KEPs we also consider the possibility of testing and prioritising national transplants in the solutions. We measure the performance of these policies regarding the number of transplants and the number of compatibility tests conducted in a time period. By extending our results presented in [16], we performed simulations for a large number of instances to measure the effects of various re-optimisation policies. Our main findings show a clear trade-off in the number of transplants versus the number of tests and re-optimisation rounds. [ABSTRACT FROM AUTHOR]

Transformer-based language models (TLMs) have widely been recognized to be a cutting-edge technology for the successful development of deep-learning-based solutions to problems and applications that require natural language processing and understanding. Like for other textual domains, TLMs have indeed pushed the state-of-the-art of AI approaches for many tasks of interest in the legal domain. Despite the first Transformer model being proposed about six years ago, there has been a rapid progress of this technology at an unprecedented rate, whereby BERT and related models represent a major reference, also in the legal domain. This article provides the first systematic overview of TLM-based methods for AI-driven problems and tasks in the legal sphere. A major goal is to highlight research advances in this field so as to understand, on the one hand, how the Transformers have contributed to the success of AI in supporting legal processes, and on the other hand, what are the current limitations and opportunities for further research development. [ABSTRACT FROM AUTHOR]

Technology has substantially transformed the way legal services operate in many different countries. With a large and complex collection of digitized legal documents, the judiciary system worldwide presents a promising scenario for the development of intelligent tools. In this work, we tackle the challenging task of organizing and summarizing the constantly growing collection of legal documents, uncovering hidden topics, or themes that later can support tasks such as legal case retrieval and legal judgment prediction. Our approach to this problem relies on topic discovery techniques combined with a variety of preprocessing techniques and learning-based vector representations of words, such as Doc2Vec and BERT-like models. The proposed method was validated using four different datasets composed of short and long legal documents in Brazilian Portuguese, from legal decisions to chapters in legal books. Analysis conducted by a team of legal specialists revealed the effectiveness of the proposed approach to uncover unique and relevant topics from large collections of legal documents, serving many purposes, such as giving support to legal case retrieval tools and also providing the team of legal specialists with a tool that can accelerate their work of labeling/tagging legal documents. [ABSTRACT FROM AUTHOR]

Milling chatter, a significant impediment to machining efficiency, adversely affects tool life and workpiece quality. To address this problem, this study presents a novel control method based on the embedded electromagnetic actuator (EMA) in the tool holder. By integrating a displacement sensor with the EMA, a comprehensive active control structure is established. System modeling and mechatronic modeling follow. Based on the results of the sweep experiments, a PD controller with optimal phase compensation is designed. During operation, this controller detects the vibration displacement of the tool holder and dampens its weak modes, thereby managing the chatter frequency. The method is validated by numerical simulations using impact and milling force identification test data. In addition, two milling experiments demonstrated the effectiveness of the method. Spindle-tool system chatter was significantly reduced, resulting in improved machining quality. In conclusion, our proposed structure and control strategy offers a powerful remedy to the challenges of milling chatter. [ABSTRACT FROM AUTHOR]

In this paper, we propose an optical image encryption scheme based on modified 3D double-phase encoding algorithm (3D-DPEA) in the gyrator transform (GT) domain, in which a plaintext is encrypted into two sparse volumetric ciphertexts under the constraints of chaos-generated binary amplitude masks (BAMs). Then, the two volumetric ciphertexts are multiplexed into the corresponding 2D ciphertexts for convenient storage and transmission. First, due to the synergistic adjustment of the two sparse volumetric ciphertexts during the iterative process, the 3D-DPEA would achieve higher recovery quality of the decrypted image with fewer iterations. In addition, because the BAMs are generated by the logistic-tent (LT) chaotic map which is closely related to the rotation angles of GT, and the LT chaotic map has several advantages such as nonlinear, pseudorandom behavior, and high sensitivity of initial conditions, the sensitivity of the secret key could be significantly improved by several orders of magnitude, reaching up to 10−14. As a result, the 3D-DPEA scheme not only eliminates the explicit/linear relationship between the plaintext and the ciphertext but also substantially enhances security. For decryption, the corresponding decrypted image can be achieved by recording an intensity pattern when a coherent beam crosses two sparse volumetric ciphertexts sequentially. Furthermore, BAMs wouldn't impose an additional burden on the storage and transmission of secret keys. A series of numerical simulations are performed to verify the effectiveness and security of the proposed encryption scheme. [ABSTRACT FROM AUTHOR]

The time-dependent Ginzburg-Landau (TDGL) model requires the choice of a gauge for the problem to be mathematically well-posed. In the literature, three gauges are commonly used: the Coulomb gauge, the Lorenz gauge and the temporal gauge. It has been noticed (J. Fleckinger-Pellé et al. in Dynamics of the Ginzburg-Landau equations of superconductivity, Technical report, Argonne National Lab. (ANL), Argonne, IL, United States, 1997) that these gauges can be continuously related by a single parameter considering the more general ω -gauge, where ω is a non-negative real parameter. In this article, we study the influence of the gauge parameter ω on the convergence of numerical simulations of the TDGL model using finite element schemes. A classical benchmark is first analysed for different values of ω and artefacts are observed for lower values of ω . Then, we relate these observations with a systematic study of convergence orders in the unified ω -gauge framework. In particular, we show the existence of a tipping point value for ω , separating optimal convergence behaviour and a degenerate one. We find that numerical artefacts are correlated to the degeneracy of the convergence order of the method and we suggest strategies to avoid such undesirable effects. New 3D configurations are also investigated (the sphere with or without geometrical defect). [ABSTRACT FROM AUTHOR]

Robot roller hemming is an advanced assembly process used to achieve high-precision manufacturing of autobody panels. The coupling action between metal panels and non-Newtonian adhesive, complex contour curve, and coverage of the autobody and hemming parameters all have significant influence on the forming quality of the autobody. In traditional robot hemming process, roller pose and trajectory are totally set at the beginning and incapable to adjust according to the hemming quality, making it difficult to further improve the appearance and assembly accuracy. Therefore, taking dimension deviation of the autobody as research object, an optimization model and algorithm of the robot roller hemming process were proposed, and built a robot hemming platform to analyze the optimization model and algorithm. Firstly, the stress-geometry interactions of roller hemming process were considered, and the mapping model between the dimension deviation and the hemming parameter (TCP-RTP) and roller pose was established based on FEM-SPH numerical simulation, Frenet frame of differential geometry, and Cartesian coordinate transformation theory, then the optimized roller pose was obtained through the mapping model. Secondly, the detection of hemming defects and measurement of dimensional deviation were realized based on the machine vision. Finally, the experimental platform was constructed and the experiment showed that the dimension deviation of the closure panel was reduced and then overshoots, and finally stabilized within 0.1 mm, after adopting the optimization algorithm. [ABSTRACT FROM AUTHOR]

Monitoring water uptake in cementitious systems is crucial to assess their durability against corrosion, salt attack, and freeze-thaw damage. However, gauging absorption currently relies on labor-intensive and infrequent weight measurements, as outlined in ASTM C1585. To address this issue, we introduce a custom computer vision model trained on 6234 images, consisting of 4000 real and 2234 synthetic, that automatically detects the water level in prismatic samples absorbing water. This model provides accurate and frequent estimations of water penetration values every minute. After training the model on 1440 unique data points, including 15 paste mixtures with varying water-to-cement ratios from 0.4 to 0.8 and curing periods of 1 to 7 days, we can now predict initial and secondary sorptivities in real time with high confidence, achieving R² > 0.9. Finally, we demonstrate its application on mortar and concrete systems, opening a pathway toward low-cost and automated durability assessment of construction materials. Monitoring water uptake in cementitious materials is important to assess their durability. Here, the authors introduce a low-cost computer vision method to predict initial and secondary sorptivity in real time in paste, mortar, and concrete systems. [ABSTRACT FROM AUTHOR]

We consider heat transport within a discontinuous domain by relying on the modeling approach proposed by Baioni et al. Such approach has been specifically designed to address diffusive processes in media with discontinuous physical properties and generalized boundary conditions at the discontinuities. Three algorithms are here applied to estimate the conductive heat transport in a bimaterial medium. The algorithms undergo testing using two test cases that share the same computational domain but differ in terms of their initial conditions. According to the numerical results all the algorithms ensure the conservation of thermal energy and preserve thermal equilibrium under steady state conditions. The Generalized Uffink Method (GUM) and Generalized HYMLA demonstrate sensitivity to the choice of the time step, whereas the Generalized Skew Brownian Motion appears to be unaffected by the value of Δ t . The GUM algorithm presents an optimal trade-off between accuracy and computational time. [ABSTRACT FROM AUTHOR]

Rapid technological advances and growing participation from amateur naturalists have made countless images of insects in their natural habitats available on global web portals. Despite advances in automated species identification, traits like developmental stage or health remain underexplored or manually annotated, with limited focus on automating these features. As a proof-of-concept, we developed a computer vision model utilizing the YOLOv5 algorithm to accurately detect monarch butterfly caterpillars in photographs and classify them into their five developmental stages (instars). The training data were obtained from the iNaturalist portal, and the photographs were first classified and annotated by experts to allow supervised training of models. Our best trained model demonstrates excellent performance on object detection, achieving a mean average precision score of 95% across all five instars. In terms of classification, the YOLOv5l version yielded the best performance, reaching 87% instar classification accuracy for all classes in the test set. Our approach and model show promise in developing detection and classification models for developmental stages for insects, a resource that can be used for large-scale mechanistic studies. These photos hold valuable untapped information, and we've released our annotated collection as an open dataset to support replication and expansion of our methods. [ABSTRACT FROM AUTHOR]

Periodical cicadas are remarkable for their incredibly long, prime-numbered life cycles and almost perfectly synchronized mass emergence. Synchronized emergence is a generally localized event, referred to as a "brood". Broods are separated in space and time, or parapatric; adjacent broods emerge on different schedules, whereas some cicadas emerge off schedule, called stragglers. Straggling can potentially erode brood boundaries; thus, the mechanism allowing broods to maintain nonoverlapping distributions is highly puzzling. Here, we propose that predation may allow broods to exclude each other. Our model and numerical simulations show that predation could act as an important factor for maintaining the nonoverlapping distributions. The proposed mechanism is most effective in the vicinity of the critical strength of predation, beyond which the population is doomed to extinction. An increase in predation intensity increases resistance to settlement of a minority brood, while suppressing the main brood population. [ABSTRACT FROM AUTHOR]

Vertical holes of several tens of meters in diameter and depth have been discovered on the Moon, potentially serving as skylights into subsurface volcanic caverns resembling lava tubes. Because of their scientific importance and potential for use as future lunar bases, these lunar holes and caverns are expected to be targets of intensive exploration in the near future. Using numerical simulations, this study investigates the light environment within a directly and/or indirectly sunlit subsurface cavern accessed through a skylight hole. We specifically analyze the Mare Tranquillitatis Hole (MTH), one of the largest lunar vertical holes, situated near the Moon's nearside meridian. The floor and walls of the hole, and the walls and ceiling of its associated subsurface cavern are lit by reflected sunlight from other parts of the hole and cavern, such as the floors, depending on the solar elevation angle. Furthermore, this paper presents estimation results for camera imaging for a case in which solar elevation angle is 45° in the morning, which is appropriate timing for exploration. Assuming reflectance of 0.1 for the lunar hole and cavern surfaces, we estimate the incident energy onto each pixel of a camera as it descends to the hole's floor. We specifically simulate conditions for a camera with a 12-bit dynamic range, similar to the wide-angle optical navigation camera (ONC-W) onboard the Hayabusa 2 spacecraft. The results suggest that a camera with a fixed gain would struggle to capture both directly and indirectly sunlit areas simultaneously, without saturating bright areas and ensuring minimum incident energy resolution (say, a 10 digital number) for darker areas. To overcome this challenge, adjusting the camera gain based on the hole's and cavern's illumination conditions is necessary. [ABSTRACT FROM AUTHOR]

Two-high screw rolling of stainless-steel billets at feed angles of 6, 12, 18, and 24° was numerically simulated. It was established that increasing the feed angle of the rolls decreases the magnitude and inhomogeneity of the shear strains in the billet cross-section. With increase in the feed angle, the difference between the total velocities zone on the surface and at the center of the billet in the deformation decreases by 57%, the length of the geometric deformation zone decreases, and the length of the actual deformation zone increases by 16%. [ABSTRACT FROM AUTHOR]

In this paper, we develop an enhanced version of the catching-up algorithm for sweeping processes through an appropriate concept of approximate projection. We establish some properties of this notion of approximate projection. Then, under suitable assumptions, we show the convergence of the enhanced catching-up algorithm for prox-regular, subsmooth, and merely closed sets. Finally, we briefly discuss some efficient numerical methods for obtaining approximate projections. Our results recover classical existence results in the literature and provide new insights into the numerical simulation of sweeping processes. [ABSTRACT FROM AUTHOR]

In this work, a novel procedure for assessing the strength and the orientation of failure/localization plane in transversely isotropic rock masses is developed. The specification of a failure plane is required in a broad range of methodologies used for assessing the limit load of geotechnical structures, which include the limit equilibrium approach, the upper bound limit analysis as well as incremental numerical analysis dealing with localization and propagation of damage. The approach employed here incorporates an enhanced analytical form of a Mohr failure envelope corresponding to generalized Hoek Brown criterion. The latter is defined in terms of components of traction vector acting on a plane of a given orientation. The proposed methodology incorporates the critical plane approach in which the strength parameter(s) vary with the spatial orientation of these planes. A comprehensive numerical study is conducted, involving assessment of conditions at failure and the orientation of failure plane in a series of conventional triaxial and true triaxial tests. The results of numerical simulations provide a clear illustration of how the intermediate principal stress and the orientation of fabric influence the failure behavior of rock masses. Highlights: A novel methodology, combining the critical plane approach with the transversely isotropic extension of an approximate Mohr envelope of the generalized Hoek–Brown (GHB) criterion, is presented. The proposed approach establishes a robust framework for predicting the failure behavior of transversely isotropic rocks under general 3D stress conditions. The process of identifying strength parameters for the transversely isotropic GHB criterion is explained. Using the proposed methodology, a comprehensive numerical simulation of conventional and true triaxial compression tests on inclined samples is conducted. [ABSTRACT FROM AUTHOR]

Proper presetting of circular holes is the crux of blasting control. Currently, the influence mechanism of preset circular holes on directional propagation of blast-induced cracks remains unclear due to the instantaneity of blast loading and the complexity of action process. In this study, the evolution of the stress field around preset holes under blast loading was clarified based on experiments and numerical simulations. Besides, the influence mechanisms of single holes with different offset distances and double holes with different hole spacings on propagation patterns of blast-induced cracks were revealed. The results show that circular holes do not just promote or inhibit the propagation of blast-induced cracks under blast loading. Instead, the effect of a preset circular hole is determined by its relative position to the blast hole. Specifically, at the top of the blast-facing side of a preset hole, rock is subjected to tensile stress, which promotes crack propagation; in contrast, on two sides of it, rock is subjected to compressive stress, which inhibits crack propagation. Moreover, when the offset distance is short, the crack propagation trajectory will be deflected under the influence of tensile stress at the top of the circular hole. With the increase of offset distance, the inhibitory effect of compression at two sides of the hole tends to dominate, and the crack propagation will be suppressed. Particularly, the inhibitory effect at the two sides gradually weakens with the increase of offset distance. In the case of double-hole arrangement, the compressive stress fields at hole sides overlap with each other, which further strengthens the inhibitory effect on propagation of blast-induced cracks. Highlights: Experiments and numerical simulations were conducted to explore the interaction mechanism between circular holes and blast-induced cracks. Circular holes do not just promote or inhibit the propagation of blast-induced cracks. Instead, the effect of a circular hole is determined by its relative position to the blast hole. At the top of the blast-facing side of a preset hole, rock is subjected to tensile stress, which promotes crack propagation; in contrast, on two sides of it, rock is subjected to compressive stress, which inhibits crack propagation. [ABSTRACT FROM AUTHOR]

This paper investigates the behavior of a medical guidewire within a vessel with a specific focus on its buckling, commonly known as tip load. The guidewire is simulated as a variable section microshaft embedded in an elastic environment, and a comprehensive buckling analysis is carried out based on the modified couple stress theory (MCST). The fundamental frequency is determined by applying Hamilton's principle and Rayleigh's method. A formula for calculating the buckling force is subsequently introduced. Numerical simulations were conducted to analyze the impact of the material properties, tapered tip length, core thickness, slenderness ratio, and material length scale parameter on the tip load and penetration force. Furthermore, a comparative study was carried out to validate the proposed formulation. The findings derived from this research can provide valuable insights for the optimization and exploration of various parameters related to medical guidewires. The findings indicate that coronary guidewires with lengths exceeding 10 cm exhibit minimal variations in tip load, whereas those with lengths below this threshold experience a substantial decrease of 65–75% in both tip load and penetration force when the length is doubled. In addition, nitinol guidewires demonstrate greater flexibility, with their tip load being nearly 75% lower than that of stainless steel guidewires of equivalent dimensions. Moreover, there is a notable increase in penetration force with an expanding radius, with tapered tips resulting in an approximate 20–30% increase in penetration force. [ABSTRACT FROM AUTHOR]

This paper provides a least squares regression estimation of the tail index for long memory processes where the innovations are α -stable random sequences. The estimate is based on the property of the characteristic function of the process near the origin. The asymptotics of the estimator are obtained by choosing suitable regression samples with the help of the properties of the α -stable distribution. The numerical simulation and an empirical analysis of financial market data are conducted to assess the finite sample performance of the proposed estimator. [ABSTRACT FROM AUTHOR]

Rolling technology with rigid arc rollers presents an innovative approach for the rapid manufacturing of three-dimensional surface components. The unique design generates a variable gap between the rollers, applying lateral bending and uneven compression to sheet metal, thus producing components with complex curvatures. Employing finite element simulation and experimental studies, this research investigates the effects of rotational speed variations on the bending deformation and dimensional accuracy of three-dimensional surface parts. The research findings indicate that as the ratio of rotational speeds between the convex and concave rolls increases from 0.75 to 2, the longitudinal curvature of the saddle-shaped parts gradually increases and then stabilizes, while the transverse curvature decreases. In contrast, for spherical parts, the longitudinal curvature shows an initial decrease followed by stabilization, with minimal changes observed in the transverse curvature. The degree to which the roller rotational speed ratio impacts curvature intensifies with increasing sheet metal compression. These findings suggest that the roll rotational speed ratio can be used as a new process parameter to enhance the curvature range and surface precision of formed parts. [ABSTRACT FROM AUTHOR]

For the purpose of improving the forming quality of cold extrusion internal thread and investigating the interactive effects of distinct process parameters on the forming quality of internal thread, this article established a regression response model between the influencing factors and optimization objectives by using the response surface experiment analysis method, and obtained the interactive effects of the bottom hole diameter, the extrusion speed and the coefficient of friction on the extrusion torque, extrusion temperature, and tooth height rate. The objective function was optimized using the regression model to obtain the optimal combination of parameters (bottom hole diameter 7.34 mm, extrusion speed 30 r/min, and friction coefficient 0.11). For the purpose of verifying the feasibility and validity of the theoretical model and the optimized design, internal thread extrusion experiments are carried out under the optimal combination parameters. The experiment results show that the extrusion torque is 3.17 N m, the extrusion temperature is 79.8 °C, and the tooth height rate is 77.23%, and the error with the predicted value is 8.56%, 2.57%, and 5.27%, respectively, which further demonstrates the accuracy of the model. [ABSTRACT FROM AUTHOR]

The resulting fibre orientation when pressing Sheet Moulding Compound (SMC) is essentially dependent on the position and geometry of the resin mat in the mould. It is desirable to adapt the fibre orientation as best as possible to best withstand the applied load. The relationship between the position and geometry of the resin mat and the deflection of the final part under a specific load can be mapped using a numerical simulation; nevertheless, an optimisation is not feasible based on the simulation in an economically reasonable time frame due to the required computing time. For this reason, a metamodel based on an ensemble of artificial neural networks (ANN) was created on the basis of the simulation data, and an optimisation based on these ANN was set up. However, the investigations show that the minimal deflections found on the basis of the metamodel through optimisation have large deviations compared to the simulation. This leads to the hypothesis that the applied optimisation finds weak points of the metamodel instead of actual minima. From this hypothesis, an extension approach of the data set on which the metamodel is based by the weak points found is derived and implemented. This is done in an iterative process. The results show that the goal of increasing the prediction quality of the optimisation approach is achieved by the developed approach. The root mean square error (RMSE) could be reduced from the original deflection of 25 to 7 mm, which corresponds to a reduction of 72%. It is shown that the presented approach is successful in increasing prediction quality; nevertheless, further measures are needed to reach decent prediction quality. [ABSTRACT FROM AUTHOR]

Psychology originally defined parent–child conflict in terms of interpersonal relationships, where parent–child conflict is a process of inconsistent attitudes between parents and children that occurs in a family setting. For this end, we aims to investigate the influence of parental awareness on preschoolers' perception of parent–child conflict and the mediating role of preschoolers' self-esteem. This paper proposes a dynamic parent–child relationship discovery algorithm based on the impact of parent–child cooperation activities on preschool children's development. We applied SPSS and Mplus statistical software for data processing and analysis, and Nvivo 11.0 qualitative software for validation and analysis. The reliability of preschool children's perceived parent–child conflict and sub-dimensions were: 0.901, 0.799, 0.791, 0.811, 0.729; the total scale and the retest reliability of each dimension were: 0.914, 0.837, 0.836, 0.792, 0.711. Validated factor analysis using Mplus: RMSEA = 0.075, TLI = 0.856, CFI = 0.876, SRMR = 0.064. [ABSTRACT FROM AUTHOR]

This study delves into fixed-time and predefined-time bipartite consensus tracking (BCT) of second-order multi-agent systems (MASs), where cooperative and competitive behaviors coexist, while accounting for bounded disturbances. Based on the sliding mode control method, the fixed-time and predefined-time control protocols are proposed to ensure the achievement of fixed-time and prescribed-time BCT for the MASs, which can effectively eliminate singularity and chattering. Leveraging Lyapunov stability, we establish a set of adequate conditions to achieve fixed-time and predefined-time BCT for second-order MASs. Furthermore, we present numerical simulation results to substantiate the theoretical conclusions. [ABSTRACT FROM AUTHOR]

Aggregates consisting of submicron-sized cohesive dust grains are ubiquitous, and understanding the collisional behavior of dust aggregates is essential. It is known that low-speed collisions of dust aggregates result in either sticking or bouncing, and local and permanent compaction occurs near the contact area upon collision. In this study, we perform numerical simulations of collisions between two aggregates and investigate their compressive behavior. We find that the maximum compression length is proportional to the radius of aggregates and increases with the collision velocity. We also reveal that a theoretical model of contact between two elastoplastic spheres successfully reproduces the size- and velocity-dependence of the maximum compression length observed in our numerical simulations. Our findings on the plastic deformation of aggregates during collisional compression provide a clue to understanding the collisional growth process of aggregates. [ABSTRACT FROM AUTHOR]

In multi-regional clinical trials, planning the sample size for participating regions is essential for the evaluation of the treatment effect consistency across regions. Based on the MRCT design and sample size allocation to regions, consistency probability is usually used to predict the consistent trend between regions and the overall population, while preserving a certain proportion of the overall treatment effect. Specific enrollment characteristics in a region of interest should also be considered during the time of the sample size planning. To facilitate efficient and harmonized regional sample size planning, we have developed RegionSizeR, a comprehensive and user-friendly interactive web-based R shiny application that can be obtained from https://github.com/rsr-ss/RegionSizeR. This simulation-based app can serve as an initial point for discussions on sample size allocation plans, following preservation of treatment effect method in ICH E17. The app accommodates various types of endpoints and designs, including continuous, binary, and time-to-event endpoints, for superiority, non-inferiority, and MCP-Mod designs. To ensure the validity of this app, independent testing is conducted allowing a discrepancy of no more than 1% across all results considering various scenarios. [ABSTRACT FROM AUTHOR]

The thermal recovery is facing the challenge of improving quality and efficiency. Steam-assisted gravity drainage (SAGD) steam circulation has a profound implications for the formal production. There is a lack of research on the situation when the steam injection pressure of injection well is lower than that of production well during startup stage. In this paper, the effects of diverse injection pressure difference on SAGD steam circulation and production stage are investigated by analytical modeling and numerical simulation, especially when the steam injection pressure of producer well is larger than that of injection well, and reliable results are obtained by temperature falloff test and model comparison validation. Meanwhile, in order to minimize the factors affecting the simulation accuracy, a sensitivity analysis of the temperature prediction model for the startup stage is carried out using Monte Carlo method and the finest possible mesh is used in the numerical simulation. The results show that:①The preheating results are faster and more uniform than the conventional preheating method when steam injection pressure of producer is greater than that of injector, and the subsequent production indexes are also superior to those of the conventional preheating method. ②The injected steam temperature had the greatest effect on the prediction accuracy of the analytical model; The finer the numerical simulation grid division, the lower the midpoint temperature of the horizontal well pair; ③An optimal range of injection pressure differences that achieves the best balance between preheating efficiency and thermal recovery effectiveness is achieved with Pprod-Pinj in the range of 400–500 kPa. ④The preheating method investigated in this paper minimizes the effect by unfavorable factors such as reservoir non-homogeneity, which holds the potential for more uniform, time-saving preheating and without the addition of field equipment. [ABSTRACT FROM AUTHOR]