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The Janus metastructure (JMS) is constructed in a special way so that the electromagnetic waves (EWs) propagate in the artificially constructed metastructure from different directions, which can show different electromagnetic characteristics and present a variety of functions at the same time. Its research is of great significance for breaking through the development bottleneck of traditional single-scale and single-function devices and can serve numerous novel application scenarios. This review discusses the design and research progress of JMS from three aspects: construction method, function realization, and application scenario. Finally, we discuss the key challenges currently facing the JMS and offer a vision for future research directions. We sincerely hope that this review will not only provide new insights into the development of JMS, which is a promising and dynamic hot research area but also promote research in this area from a more diverse and comprehensive perspective.

The challenge of imbalanced data classification stems from the uneven distribution of data across classes, which is a formidable obstacle for traditional classifiers. Although numerous methods have been proposed to address this problem, it is widely recognized that the artificial generation of instances through oversampling methods is a more effective and versatile strategy for balancing the class distribution. We identify that existing oversampling methods are susceptible to generating unnecessary and noisy instances in complex imbalanced scenarios. In light of this, a novel approach called Adaptive Safe-Region Diversity Oversampling (ASRDO) is introduced to tackle difficulties in imbalanced learning. ASRDO starts by calculating the distance from each minority class instance to its nearest majority class instances. Utilizing this distance as a radius, it defines a safe hyperspherical sampling region for each minority instance. The algorithm then assigns weights to minority instances based on the density within their respective sampling regions and the average distance to k nearest majority instances. Finally, It randomly selects two instances from the k nearest minority instances, generates a new direction vector by linear combination, and synthesizes minority instances along this direction vector within the sampling region. Experimental results show a significant performance improvement of the proposed method compared to prevalent oversampling methods on 32 public datasets. A Python implementation of ASRDO is provided for reference.

Abstract Railway accidents, particularly serious derailments, can lead to catastrophic consequences. Therefore, it is essential to prevent derailment escalation to reduce the likelihood of severe derailments. Train post-derailment behaviours and containment methods play a critical role in preventing derailment escalation and providing passive safety protection and accident prevention in the event of a derailment. However, despite the increasing attention on this field from academia and industry in recent years, there is a lack of systematic exploration and summarization of emerging applications and containment methods in train post-derailment research. For this reason, this paper presents a comprehensive review of existing studies on train post-derailment behaviours, encompassing various topics such as post-derailment contact–impact models, dynamic modelling and simulation techniques, and the primary factors influencing post-derailment behaviours. Significantly, this review introduces and elucidates substitute guidance mechanisms (SGMs), which serve as railway-specific passive safety protection and accident prevention measures. The various types of SGMs are depicted, and their ongoing developments and applications are explored in depth. The review additionally points out several unresolved challenges including the adverse effects of SGMs, and proposes future research directions to advance the theoretical understanding and practical application of train post-derailment behaviours and containment methods. This review seeks to be a valuable reference for railway industry professionals in preventing catastrophic derailment consequences through post-derailment containment methods.

ABSTRACT Purpose: To observe the effect of puerarin on renal ischemia-reperfusion (I/R) injury in rats, and to explore its mechanism based on NLRP3/Caspase-1/GSDMD pathway. Methods: Twenty-one Sprague-Dawley rats were divided into three groups: sham-operated group (sham), model group (RIRI), and puerarin treatment group (RIRI + Pue). The model of acute renal I/R injury was established by cutting the right kidney and clamping the left renal pedicle for 45 min. Results: Renal function parameters were statistically significant in group comparisons. The renal tissue structure of rats in sham group was basically normal. Pathological changes were observed in the RIRI group. The renal pathological damage score and apoptosis rate in the RIRI group were higher than those in the sham group, and significantly lower in the RIRI + Pue group than in the RIRI group. Indicators of oxidative stress–superoxide dismutase, malondialdehyde, and glutathione peroxidase–were statistically significant in group comparisons. Compared with the sham group, the relative expressions of NLRP3, Caspase-1 and GSDMD proteins in the RIRI group were increased. Compared with the RIRI group, the RIRI + Pue group had significant reductions. Conclusions: Puerarin can inhibit the activation of NLRP3/Caspase-1/GSDMD pathway, inhibit inflammatory response and pyroptosis, and enhance the antioxidant capacity of kidney, thereby protecting renal I/R injury in rats.

Abstract Background Idiopathic pulmonary fibrosis (IPF) is a chronic, progressive fibrosing lung disease with high mortality. Inflammation and epithelial mesenchymal transformation (EMT) may play an important role in the occurrence and development of IPF. Qing-Re-Huo-Xue formula (QRHXF) has been used clinically by our team for half a century and has obvious therapeutic effects on lung disease. Nevertheless, the role and mechanism of QRHXF in the treatment of IPF have never been studied. Methods A mouse pulmonary fibrosis model was established by intratracheal injection of BLM. The effects of QRHXF on the treatment of pulmonary fibrosis were studied by pulmonary function testing, imaging examination, pathological staining, transmission electron microscopy (TEM) observation and mRNA expression. Tandem mass tag (TMT)-based quantitative proteomics was carried out to analyse the lung protein expression profiles between the control (CTL), bleomycin (BLM) and QRHXF (BLM + QRHXF) groups. Immunohistochemistry and qRT-PCR were used to verify the possible existence of drug target proteins and signalling pathways. Results The results of pulmonary function, lung pathology and imaging examinations showed that QRHXF could significantly alleviate BLM-induced pulmonary fibrosis in vivo. Additionally, inflammatory cell infiltration and EMT were markedly reduced in BLM-induced PF mice administered QRHXF. Proteomics detected a total of 35 proteins, of which 17 were upregulated and 18 were downregulated. A total of 19 differentially expressed proteins (DEPs) overlapped between the BLM versus CTL groups and the BLM + QRHXF versus BLM groups. The expression of p53 and IGFBP3 was reversed in the QRHXF intervention group, which was verified by immunohistochemistry and qRT-PCR. Conclusions QRHXF attenuated BLM-induced pulmonary fibrosis, and regulation of the p53/IGFBP3 pathway might be associated with its efficacy, which holds promise as a novel treatment strategy for pulmonary fibrosis patients. Graphical Abstract

Abstract The electronic structure of two-dimensional (2D) materials are inherently prone to environmental perturbations, which may pose significant challenges to their applications in electronic or optoelectronic devices. A 2D material couples with its environment through two mechanisms: local chemical coupling and nonlocal dielectric screening effects. The local chemical coupling is often difficult to predict or control experimentally. Nonlocal dielectric screening, on the other hand, can be tuned by choosing the substrates or layer thickness in a controllable manner. Therefore, a compelling 2D electronic material should offer band edge states that are robust against local chemical coupling effects. Here it is demonstrated that the recently synthesized MoSi2N4 is an ideal 2D semiconductor with robust band edge states protected from capricious environmental chemical coupling effects. Detailed many-body perturbation theory calculations are carried out to illustrate how the band edge states of MoSi2N4 are shielded from the direct chemical coupling effects, but its quasiparticle and excitonic properties can be modulated through the nonlocal dielectric screening effects. This unique property, together with the moderate band gap and the thermodynamic and mechanical stability of this material, paves the way for a range of applications of MoSi2N4 in areas including energy, 2D electronics, and optoelectronics.

Robot and programming education, as a key part of STEM education, is attracting more and more attention in the education industry. In this paper, a novel open-sourced educational robotic platform, Daran robot, is proposed with key features in terms of reconfigurable, powerful, and affordable. As an entry-level robotic platform, the Daran robot consists of three individual robots, which are a Mecanum-wheeled robot, a three-wheeled robot, and a 4-DoF robot arm. Both graphical and Python programming environments are developed for students with different entry levels. Thanks to the reconfigurability, four classic constructions of the Daran robot are presented with corresponding case studies, based on which the students can practically learn basic knowledge of sensing and control technologies.

PurposeTo develop and validate a quantitative model based on gross tumor volume (GTV) of gastric adenocarcinoma (GA) corresponding to N-stage measured at multidetector computed tomography (CT) for preoperative determination of resectabilityMaterials and methods493 consecutive patients with confirmed GA undergoing contrast-enhanced CT two weeks before treatments were randomly enrolled into the training cohort (TC, n = 271), internal validation cohort (IVC, n = 107) and external validation cohort (EVC, n = 115). GTV was measured on CT by multiplying sums of all tumor areas by section thickness. In TC, univariate and multivariate analyses were performed to select factors associated with resectability. Receiver operating characteristic (ROC) analysis was to determine if N-stage based GTV could identify resectability. In IVC and EVC, unweighted Cohen’s Kappa tests were to evaluate performances of the ROC models.ResultsAccording to univariate analysis, age, cT stage, cN stage and GTV were related to resectability in TC (all P-values < 0.05), and multivariate analysis suggested that cN stage and GTV were independent risk factors with odds ratios of 1.594 (95% confidence interval [CI]: 1.105–2.301) and 1.055 (95%CI: 1.035–1.076), respectively. ROC analysis in TC revealed the cutoffs of 21.81, 21.70 and 36.93 cm3 to differentiate between resectable and unresectable cancers in stages cN0-3, cN2 and cN3 with areas under the curves of more than 0.8, respectively, which was validated in IVC and EVC with average Cohen k-values of more than 0.72.ConclusionsGTV and cN stage can be independent risk factors of unresectable GA, and N-stage based GTV can help determine resectability.

Abstract Background Gestational diabetes mellitus (GDM) increased risk of perinatal complications for both the women and the fetuses. The association between the vitamin D receptor (VDR) gene polymorphism and GDM has not been thoroughly investigated in Chinese pregnant women. Therefore, we aimed to determine whether VDR gene single nucleotide polymorphisms (SNPs) rs154410, rs7975232, rs731236, rs2228570 and rs739837 contribute to GDM risk in Wuhan, China. Moreover, we aimed to explore their combined effects on the risk of GDM. Methods Pregnant women who had prenatal examinations at 24 to 28 weeks’ gestation in our hospital from January 15, 2018 to March 31, 2019 were included in this case-control study. After exclusion, a total of 1684 pregnant women (826 GDM patients and 858 non-diabetic controls) were recruited. The clinical information and blood samples were collected by trained interviewers and nurses. Genotyping of candidate SNPs was conducted on the Sequenom MassARRAY platform. Statistical analyses including t-test, ANOVA, chi-square test and logistic regression were performed to the data with SPSS Software to evaluate differences in genotype distribution and associations with GDM risk. Multifactor dimensionality reduction method was used to explore the gene-gene interactions on the risk of GDM. Results Differences in age, pre-pregnancy BMI, family history of diabetes and previous history of GDM between the case and control groups were statistically significant (P 0.05). There were no significant differences at genotype distributions of the examined VDR gene SNPs (P > 0.05). After adjusting by age, pre-pregnancy BMI, family history of diabetes, the results of logistic regression analysis showed no associations of the five SNPs with GDM in all the four genotype models(P > 0.05). Furthermore, there were no gene-gene interactions on the GDM risk among the five examined VDR gene SNPs. Conclusions The VDR gene SNPs rs154410, rs7975232, rs731236, rs2228570 and rs739837 showed neither significant associations nor gene-gene interactions with GDM in Wuhan, China.

Objective: To explore the effect of Orff vocal therapy on BODE index and quality of life of patients with low lung function after non-small cell lung cancer surgery. Methods: From March 2014 to March 2019, 231 patients with NSCLC postoperative (their pulmonary functions FEV1 ≤50% of the expected value) in the Huashan Hospital, Fudan University were selected and randomly divided into observation groups and control group. On the basis of conventional treatment of NSCLC, the control group used lung rehabilitation training, and the observation group used the Orff music therapy. They carry out vocal and breath training step by step, using a combination of online and offline methods, 1h per day online interactive training, 2h of offline group vocal therapy once a week, continuous intervention for 12 months. The patient’s BODE index and FACT-L scores were monthly follow-up. Results: Compared with the control group, the BODE index and FACT-L scores improved more significantly in the vocal therapy group (P

Pulmonary fibrosis is a manifestation of the progression of interstitial pulmonary disease. Icariin (ICA) has been found to exhibit protective effects on multiple chronic diseases like diabetes, liver, heart, and renal fibrosis. Here, a systemic pharmacological study was designed to investigate whether ICA treatment alleviates bleomycin (BLM)-induced pulmonary fibrosis. The rat pulmonary fibrosis model was constructed by non-invasive endotracheal intubation instillation of BLM to observe the intervention effects of ICA on pulmonary fibrosis in the whole process of inflammation and fibrosis. ICA reduced the collagen deposition and inflammation induced by BLM in rat. The comparative RNA-sequencing was conducted to analyze the lung gene expression profiles in rat. KEGG analysis indicated that most of the genes were enriched in Hippo pathway, NF-κB pathway, and B-cell receptor signaling pathway, etc. Immunohistochemistry staining showed that the expression of YAP was significantly elevated in the model group and decreased in the ICA treatment group. Taken together, the anti-fibrotic effect of ICA appears to be mediated by its inhibitory of YAP, which is the core transcriptional regulator of Hippo pathway.

With the advantages of high flexibility, strong adaptability, etc., the legged robot can help humans to complete numerous complicated tasks. In this paper, a kind of reconfigurable legged robot with a flexible waist was proposed. Compared with the common robots with a rigid trunk, the proposed robot can twist its waist flexibly. Through analysis, it is found that the flexible waist can improve the trunk workspace, foot endpoints’ workspace and static stability margin of the robot, and further enhance the motion performance of the robot. Meanwhile, by imitating the creatures in nature, the motion gait planning of the robot was provided. Additionally, the proposed robot has excellent reconfigurable characteristics, and can flexibly transform among three forms to adapt to different working environments and accomplish different tasks. Further, after capsizing, the robot can complete the motion of turning over more easily. In this paper, the reconfiguration posture and the motion of turning over of the robot were planned in detail, and finally verified by ADAMS simulation.

Allergic asthma is well known as a common respiratory disorder comprising an allergic inflammatory nature and excessive immune characteristic. N6-methyladenosine (m6A) methylation is an RNA epigenetic modification that post-transcriptionally regulates gene expression and function by affecting the RNA fate. Currently, m6A methylation is gaining attention as a mechanism of immunoregulation. However, whether m6A methylation engages the pathological process of asthma remains uncertain. Here, we present the m6A methylomic landscape in the lung tissues of ovalbumin-induced acute asthma mice using MeRIP-seq and RNA-seq. We identified 353 hypermethylated m6A peaks within 329 messenger RNAs (mRNAs) and 150 hypomethylated m6A peaks within 143 mRNAs in the lung tissues of asthmatic mice. These differentially methylated mRNAs were found to be involved in several immune function-relevant signaling pathways. In addition, we predicted 25 RNA-binding proteins that recognize the differentially methylated peak sites by exploring public databases, and the roles of these proteins are mostly related to mRNA biogenesis and metabolism. To further investigate the expression levels of the differentially methylated genes, we performed combined analysis of the m6A methylome and transcriptome data and identified 127 hypermethylated mRNAs (107 high and 20 low expression) and 43 hypomethylated mRNAs with differential expressions (9 high and 34 low expression). Of these, there are a list of mRNAs involved in immune function and regulation. The present results highlight the essential role of m6A methylation in the pathogenesis of asthma.

ObjectiveTo investigate relationship of tumor stage-based gross tumor volume (GTV) of esophageal squamous cell carcinoma (ESCC) measured on computed tomography (CT) with early recurrence (ER) after esophagectomy.Materials and MethodsTwo hundred and four consecutive patients with resectable ESCC including 159 patients enrolled in the training cohort (TC) and 45 patients in validation cohort (VC) underwent contrast-enhanced CT less than 2 weeks before esophagectomy. GTV was retrospectively measured by multiplying sums of all tumor areas by section thickness. For the TC, univariate and multivariate analyses were performed to determine factors associated with ER. Mann-Whitney U test was conducted to compare GTV in patients with and without ER. Receiver operating characteristic (ROC) analysis was performed to determine if tumor stage-based GTV could predict ER. For the VC, unweighted Cohen’s Kappa tests were used to evaluate the performances of the previous ROC predictive models.ResultsER occurred in 63 of 159 patients (39.6%) in the TC. According to the univariate analysis, histologic differentiation, cT stage, cN stage, and GTV were associated with ER after esophagectomy (all P-values < 0.05). Multivariate analysis revealed that cT stage and GTV were independent risk factors with hazard ratios of 3.382 [95% confidence interval (CI): 1.533–7.459] and 1.222 (95% CI: 1.125–1.327), respectively (all P-values < 0.05). Mann-Whitney U tests showed that GTV could help differentiate between ESCC with and without ER in stages cT1-4a, cT2, and cT3 (all P-values < 0.001), and the ROC analysis demonstrated the corresponding cutoffs of 13.31, 17.22, and 17.83 cm3 with areas under the curve of more than 0.8, respectively. In the VC, the Kappa tests validated that the ROC predictive models had good performances for differentiating between ESCC with and without ER in stages cT1-4a, cT2, and cT3 with Cohen k of 0.696 (95% CI, 0.498–0.894), 0.733 (95% CI, 0.386–1.080), and 0.862 (95% CI, 0.603–1.121), respectively.ConclusionGTV and cT stage can be independent risk factors of ER in ESCC after esophagectomy, and tumor stage-based GTV measured on CT can help predict ER.

As an important train performance quality, comfort depends on vibration and noise data measured on a running train. Traditional vibration and noise measurement tools are facing challenges in terms of collecting big data, portability, and cost. With the continuous upgrade of mobile terminal hardware, the built-in sensors of mobile phones have the ability to undertake relatively complex data measurement and processing tasks. In this study, a new type of train comfort measurement system based on a mobile device is developed by using a built-in sensor to measure the vibration and noise. The functions of the developed system include the real-time display of three-way vibration acceleration, lateral and vertical Sperling indicators, sound pressure level, and train comfort-related data storage and processing. To verify the accuracy of the mobile device-based train ride comfort measuring system (DTRCMS), a comparison of test results from this system and from the traditional measuring system is conducted. The comparison results show that the DTRCMS is in good agreement with the traditional measuring system. The relative error in three-direction acceleration and Sperling values is 2~10%. The fluctuation range of the noise measured by DTRCMS is slightly lower than that of the professional noise meter, and the relative error is mainly between 1.5% and 4.5%. Overall, the study shows that using mobile devices to measure train comfort is feasible and practical and has great potential for big data-based train comfort evaluation in the future.

Glutamate and its receptors have been demonstrated to promote both basal and nicotine-evoked catecholamine release in bovine chromaffin cells. Multiple glutamate receptors, including metabotropic glutamate receptors (mGluRs), are found in the adrenal glands of several species, as well as in chromaffin cells. However, there is limited information available regarding the expression of glutamate metabotropic receptor (GRM)1-8 mRNAs and the detailed localization of group I mGluRs (mGluR1 and mGluR5) in the rat and human adrenal cortex and medulla. Therefore, we examined mRNA expression of GRM1-8 subunits using reverse transcription-polymerase chain reaction (RT-PCR) and the distribution of mGluR1 and mGluR5 by immunostaining. The results showed that the GRM1-8 mRNAs were expressed in both the cortex and medulla of rat and human adrenal glands with the exception of GRM1, which was not detectable in the rat adrenal cortex. Immunostaining of mGluR1 revealed that it was localized only in the adrenal medulla of rats but was present in both the adrenal cortex and medulla in humans. In the adrenal medulla, the central part of the adrenal glands, mGluR1 was detected in chromaffin cells but not in nerve fibers and ganglion cells. Immunoactivity of mGluR5 was visible in the capillary wall throughout the adrenal cortex and medulla in rat and human samples. Its immunoactivity was also observed in ganglion cells in the rat adrenal medulla. There was no mGluR5 immunoactivity detected in chromaffin cells and nerve fibers in the rat and human adrenal medulla. Using dissected rat adrenal medulla as a model, we found that treatment with a mGluR1 agonist activated extracellular signal-regulated kinase (ERK) 1/2 and increased the expression of tyrosine hydroxylase (TH), the rate-limiting enzyme of catecholamine synthesis. Moreover, these results showed that mGluR1 signaling was involved in hypoxia-induced upregulation of TH in the rat adrenal medulla. This study shows the expression of GRM1-8 mRNAs in rat and human adrenal glands and indicates that glutamate, through the activation of mGluRs, may play various physiological roles in the adrenal gland. Furthermore, mGluR1 may be involved in catecholamine biosynthesis by regulating TH, and mGluR5 may affect cortical and medullar hormone levels by regulating microvascular function.

Targeting to improve the calculation efficiency of the finite element simulation, we introduce the back propagation neural network–based machine learning method to carry out the inversion prediction framework. The inversion collision model is established based on the inversion prediction framework. Then, the prediction results are compared with the finite element simulation results of the anti-climbing device to verify the feasibility of the inversion collision model. The average prediction errors of velocity, displacement, interface force, and internal energy of the anti-climbing device are 3.7%, 4.31%, 3.4%, and 1%, respectively, and the cost time of the inversion collision model is less than 5 min. The results show that the inversion collision model constructed by back propagation neural network can significantly improve the calculation efficiency and greatly reduce the calculation time under the condition of ensuring accuracy. It will provide a new evaluation method and possibility for partially replacing the required experimental and simulation results for the crashworthiness and the safety of the anti-climbing device.

Due to the complexity of a train crash, it is a challenging process to describe and estimate mathematically. Although different mathematical models have been developed, it is still difficult to balance the complexity of models and the accuracy of estimation. This paper proposes a nonlinear spring-mass-damper model of train frontal crash, which achieves high accuracy and maintains low complexity. The Convolutional Long-short-term-memory Generation Adversarial Network (CLGAN) model is applied to study the nonlinear parameters dynamic variation of the key components of a rail vehicle (e.g., the head car, anticlimbing energy absorber, and the coupler buffer devices). Firstly, the nonlinear lumped model of train frontal crash is built, and then the physical parameters are deduced in twenty different cases using D’Alembert’s principle. Secondly, the input/output relationship of the CLGAN model is determined, where the inputs are the nonlinear physical parameters in twenty initial conditions, and the output is the nonlinear relationship between the train crash nonlinear parameters under other initial cases. Finally, the train crash dynamic characteristics are accurately estimated during the train crash processes through the training of the CLGAN model, and then the crash processes under different given conditions can be described effectively. The estimation results exhibit good agreement with finite element (FE) simulations and experimental results. Furthermore, the CLGAN model shows great potential in nonlinear estimation, and CLGAN can better describe the variation of nonlinear spring damping compared with the traditional model. The nonlinear spring-mass-damper modeling is involved in improving the speed and accuracy of the train crash estimation, as well as being able to offer guidance for structure optimization in the early design stage.

Bu-Shen-Yi-Qi formula (BSYQF) could suppress chronic airway inflammation according to previous studies. However, there is relatively little direct experimental evidence to evaluate the effects of BSYQF treatment on airway remodeling in chronic asthma. Recent evidence suggests that oxidative stress is involved in airway inflammation and airway remodeling in chronic asthma. BSYQF which includes various of chemical components having antioxidant effects, could be beneficial in attenuating airway remodeling in chronic asthma. The purpose of this study was to elucidate the effect of BSYQF treatment on airway remodeling and investigate its potential mechanisms in chronic asthma. To develop the murine models of chronic asthma, BALB/c mice were sensitized and challenged to ovalbumin for 8 weeks. BSYQF (5, 10, 20 g raw herbs/kg body weight) or tiotropium bromide (0.1 mM) were administered orally and intranasal instillation, respectively. The effect of BSYQF on pulmonary inflammation and remodeling was evaluated. The parameters of oxidative stress in the lung were analyzed. BSYQF treatment reduced airway hyperresponsiveness (AHR), Th2 response including IL-4, IL-13, and OVA-specific IgE and IgG1, transforming growth factor-β (TGF-β), vascular endothelium growth factor (VEGF), airway inflammation and airway remodeling including smooth muscle thickening and peribronchial collagen deposition. As for oxidative stress, BSYQF treatment reduced reactive oxygen species (ROS), Malondialdehyde (MDA), NO, and the expression of inducible nitric oxide synthase (iNOS), but increased significantly glutathione (GSH) /Oxidized glutathione(GSSH) ratios in the lung, restored mitochondrial ultrastructural changes of bronchial epithelia and ATP levels in the lung.In summary, this study suggested that BSYQF treatment ameliorated airway remodeling and alleviated asthmatic features in chronic asthma models. Anti-inflammatory and antioxidant effect of BSYQF may explain why BSYQF has effects on preventing airway remodeling.

The crashworthiness of a railway vehicle relates to its passive safety performance. Due to mesh distortion and difficulty in controlling the hourglass energy, conventional finite element methods face great challenges in crashworthiness simulation of large-scale complex railway vehicle models. Meshfree methods such as element-free Galerkin method offer an alternative approach to overcome those limitations but have proved time-consuming. In this article, a coupled finite element/meshfree method is proposed to study the crashworthiness of railway vehicles. A representative scenario, in which the leading vehicle of a high-speed train impacts to a rigid wall, is simulated with the coupled finite element/element-free Galerkin method in LS-DYNA. We have compared the conventional finite element method and the coupled finite element/element-free Galerkin method with the simulation results of different levels of discretization. Our work showed that coupled finite element/element-free Galerkin method is a suitable alternative of finite element method to handle the nonlinear deformation in full-size railway vehicle crashworthiness simulation. The coupled method can reduce the hourglass energy in finite element simulation, to produce robust simulation.

There has been a long-standing challenge in developing locally stationary Gaussian process models concerning how to obtain flexible partitions and make predictions near boundaries. In this work, we develop a new class of locally stationary stochastic processes, where local partitions are modeled by a soft partition process via predictive random spanning trees that leads to highly flexible spatially contiguous subregion shapes. This valid nonstationary process model knits together local models such that both parameter estimation and prediction can be performed under a unified and coherent framework, and it captures both discontinuities/abrupt changes and local smoothness in a spatial random field. We propose a theoretical framework to study the Bayesian posterior concentration concerning the behavior of this Bayesian nonstationary process model. The performance of the proposed model is illustrated with simulation studies and real data analysis of precipitation rates over the contiguous United States. for this article are available online. [ABSTRACT FROM AUTHOR]