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This study aims to achieve superior localization and mapping performance in point cloud degradation scenarios through the effective removal of dynamic obstacles. With the continuous development of various technologies for autonomous vehicles, the LIDAR-based Simultaneous localization and mapping (SLAM) system is becoming increasingly important. However, in SLAM systems, effectively addressing the challenges of point cloud degradation scenarios is essential for accurate localization and mapping, with dynamic obstacle removal being a key component.

This paper proposes a method that combines adaptive feature extraction and loop closure detection algorithms to address this challenge. In the SLAM system, the ground point cloud and non-ground point cloud are separated to reduce the impact of noise. And based on the cylindrical projection image of the point cloud, the intensity features are adaptively extracted, the degradation direction is determined by the degradation factor and the intensity features are matched with the map to correct the degraded pose. Moreover, through the difference in raster distribution of the point clouds before and after two frames in the loop process, the dynamic point clouds are identified and removed, and the map is updated.

Experimental results show that the method has good performance. The absolute displacement accuracy of the laser odometer is improved by 27.1%, the relative displacement accuracy is improved by 33.5% and the relative angle accuracy is improved by 23.8% after using the adaptive intensity feature extraction method. The position error is reduced by 30% after removing the dynamic target.

Compared with LiDAR odometry and mapping algorithm, the method has greater robustness and accuracy in mapping and localization.

The purpose of this paper is to examine the effectiveness of illegal insider trading enforcement in China by focusing, among other things, on the Chinese Securities Regulatory Commission's (CSRC) enforcement actions in the period 1993‐2006.

This paper discusses the CSRC's enforcement policies and practices of insider trading regulation, based upon administrative and judicial cases, face‐to‐face interviews with regulators, and policy documents.

A major finding of the study is the paucity of insider trading cases and the lack of convictions for insider trading offences in China. The campaign against securities offences did not actually come with the stricter enforcement of insider trading laws. A primary challenge in the insider trading regulation comes from the fact that most insider trading cases involve high‐ranking government and party officials. The CSRC lacks the power to directly administer discipline and penalties on government officials and party cadres for insider trading offences.

It is recommended that the CSRC be given more power, more resources and more trained regulators to detect and address insider trading activities. It is also recommended that the CSRC improve its surveillance capabilities by fully utilizing sophisticated computer surveillance software systems, by improving inter‐agency and inter‐market information‐sharing, and by cooperating with other countries' regulators and participating in the ISG's database to detect possible international insider trading.

The paper will be of interest to researchers in the field of financial crime and securities regulation. Regulators, the private sector and government departments will also benefit from an analysis of Chinese insider trading enforcement cases. This paper also suggests better strategies for dealing with insider trading offences in China. A fair and orderly market is crucial for investors in the Chinese market.

An investigation was conducted into the impact of various process parameters on the surface and subsurface quality of glass-ceramic materials, as well as the mechanism of material removal and crack formation, through the use of ultrasonic-assisted grinding.

A mathematical model of crack propagation in ultrasonic-assisted grinding was established, and the mechanism of crack formation was described through the model. A series of simulations and experiments were conducted to investigate the impact of process parameters on crack depth, surface roughness, and surface topography during ultrasonic-assisted surface and axial grinding. Additionally, the mechanism of crack formation was explored.

During ultrasonic-assisted grinding, the average grinding forces are between 0.4–1.0 N, which is much smaller than that of ordinary grinding (1.0–3.5 N). In surface grinding, the maximum surface stresses between the workpiece and the tool gradually decrease with the tool speed. The surface stresses of the workpiece increase with the grinding depth, and the depth of subsurface cracks increases with the grinding depth. With the increase of the axial grinding speed, the subsurface damage depth increases. The roughness increases from 0.780um/1.433um.

A mathematical model of crack propagation in ultrasonic-assisted grinding was established, and the mechanism of crack formation was described through the model. The deformation involved in the grinding process is large, and the FEM-SPH modeling method is used to solve the problem that the results of the traditional finite element method are not convergent and the calculation efficiency is low.

This case is about “Red”, a cross-border e-commerce platform developed from a community which was built to share overseas shopping experience. With sharp insights into the consumption behavior of urban white-collar women and riding on its community e-commerce advantage, “Red”, a cross-border e-commerce startup, pulled in three rounds of financing within just 16 months regardless of increasingly competitive market. On the other hand, well-established platforms such as T-mall International and Joybuy also stepped in, and their involvement will also speed up the industry integration and usher in a reshuffling period. Confronted with the “price war” started by those e-commerce giants, in what ways can “Red” adjust its shopping experience and after-sales services to enhance the brand value and sharpen its edge?

The purpose of this paper is to prepare novel electroactive shape memory nanocomposites based on graphene and study the thermomechanical property and shape memory behavior of nanocomposites.

Graphene was dispersed in N,N-dimethylformamide, and the mixture was spooned into epoxy-cyanate ester mixtures to form graphene/epoxy-cyanate ester nanocomposites. The nanocomposites were deformed under 150°C, and shape recovery test was conducted under an electric voltage of 20-100 V.

Graphene is used to improve the shape recovery behavior and performance of shape-memory polymers (SMPs) for enhanced electrical actuation effectiveness. With increment of graphene content, the shape recovery speed of nanocomposites increases significantly.

A simple way for fabricating electro-activated SMP nanocomposites has been developed by using graphene.

The outcome of this study will help to fabricate the SMP nanocomposites with high electrical actuation effectiveness and improve the shape recovery speed of the nanocomposites.

The purpose of this paper is to study the influence of calcium sulfate whiskers (CSWs) on the thermodynamic properties and shape memory properties of epoxy/cyanate ester shape memory composites.

To improve the mechanical properties of shape memory cyanate ester (CE)/epoxy polymer (EP) resin, high performance CSWs were used to reinforce the thermo-induced shape memory CE/EP composites and the shape memory CSW/CE/EP composites were prepared by molding. The effect of CSW on the mechanical properties and shape memory behavior of shape memory CE/EP composites was investigated.

After CSW filled the shape memory CE/EP composites, the bending strength of the composites is greatly improved. When the content of CSW is 5 Wt.%, the bending strength of the composite is 107 MPa and the bending strength is increased by 29 per cent compared with bulk CE/EP resin. The glass transition temperature and storage modulus of the composites were improved in CE/EP resin curing system. However, when the content of CSW is more than 10 Wt.%, clusters are easily formed between whiskers and the voids between whiskers and matrix increase, which will lead to the decrease of mechanical properties of composites. The results of shape memory test show that the shape memory recovery time of the composites decreases with the decrease of CSW content at the same temperature. In addition, the shape recovery ratio of the composites decreased slightly with the increase of the number of thermo-induced shape memory cycles.

A simple way for fabricating thermo-activated SMP composites has been developed by using CSW.

The outcome of this study will help to fabricate the SMP composites with high mechanical properties and the shape memory CSW/CE/EP composites are expected to be used in space deployable structures.

This study employed a questionnaire survey to understand the safety attitudes, focusing on safety motivation and risk tolerance as well as safety management practices, including safety training and safety incentives, among construction site employees, including both managerial personnel and frontline workers. The objective was to explore the relationship between safety management practices and safety attitudes within both the managerial and frontline worker groups.

This study was conducted among 1,026 construction workers and 256 managerial personnel at 53 construction sites across 12 provinces in China. A t-test was used to compare the differences in safety-related scores between managerial personnel and frontline workers, and a structural equation model was used to explore the relationship between safety attitudes and safety management.

This study found that the scores of managerial personnel for safety motivation, safety training and safety incentives were significantly higher than construction workers, while their scores for risk tolerance were significantly lower than construction workers. Managerial personnel’s safety motivation has a significant positive impact on both safety training and safety incentives, while their risk tolerance has a significant negative impact on safety incentives. Safety training has a significant positive effect on construction workers’ safety motivation, whereas safety incentives have a significant negative impact on construction workers’ risk tolerance.

This study is one of the few that have investigated construction safety by conducting surveys targeting both site managerial personnel and frontline workers, employing an empirical approach to validate the role of safety management in transmitting safety attitudes from site managerial personnel to frontline workers.

An accurate prediction of the deformation of retaining structures is critical for ensuring the stability and safety of braced deep excavations, while the high nonlinear and complex nature of the deformation makes the prediction challenging. This paper proposes an explainable boosted combining global and local feature multivariate regression (EB-GLFMR) model with high accuracy, robustness and interpretability to predict the deformation of retaining structures during braced deep excavations.

During the model development, the time series of deformation data is decomposed using a locally weighted scatterplot smoothing technique into trend and residual terms. The trend terms are analyzed through multiple adaptive spline regressions. The residual terms are reconstructed in phase space to extract both global and local features, which are then fed into a gradient-boosting model for prediction.

The proposed model outperforms other established approaches in terms of accuracy and robustness, as demonstrated through analyzing two cases of braced deep excavations.

The model is designed for the prediction of the deformation of deep excavations with stepped, chaotic and fluctuating features. Further research needs to be conducted to expand the model applicability to other time series deformation data.

The model provides an efficient, robust and transparent approach to predict deformation during braced deep excavations. It serves as an effective decision support tool for engineers to ensure the stability and safety of deep excavations.

The model captures the global and local features of time series deformation of retaining structures and provides explicit expressions and feature importance for deformation trends and residuals, making it an efficient and transparent approach for deformation prediction.

Laser cladding has been used in the field of repairing damaged parts of machine tools due to its advantages of less processing restrictions and easy formation of a good metallurgical bond with the base material. However, the mechanical properties of the coating sometimes cannot meet the process requirements. Therefore, the purpose of this paper is to prepare coatings with high microhardness and flexural strength.

The YCF102 alloy powder was mixed with different contents of Co and tested for laser cladding on AISI 1045 substrate under the same process parameters. The main phase composition of the coating was revealed by the XRD results. The main chemical composition of the coating was determined by the SEM and EDS results. In addition, the effect of Co content on the microstructure, microhardness and flexural strength of the coatings was investigated.

The results show that when the Co content is 2 wt% and 4 wt%, Co does not form compounds with other elements, but is uniformly distributed in the coating. And when the Co content is 6 wt% and 8 wt%, the Co reacts with Fe in the coating and generates Co₃Fe₇ in situ. The increase in Co did not result in a monotonic change in microhardness, but significantly improved the flexural strength and the flatness of the microstructure of the coating. When the Co content of the mixed powder is 8 wt%, the coating has high microhardness and flexural strength.

Co/YCF102 composite coating with high microhardness and flexural strength was prepared. This paper provides a theoretical and practical basis for research in the area of repairing damaged parts of machine tools by laser cladding.

The purpose of this paper is to investigate the effect of pulsed magnetic field (PMF) with different duty cycles on the melt flow and heat transfer behaviors during direct-chill (DC) casting of large-size magnesium alloy billet and find the appropriate range of duty cycle.

A transient two-dimensional mathematical model coupled electromagnetic field, flow field and thermal field, is conducted to study the melt flow and temperature field under PMF and compared with that under the harmonic magnetic field.

The results reveal that melt vibration and fluctuation are generated due to the instantaneous impact of repeated thrust and pull effects of Lorentz force under PMF. The peak of Lorentz force decreases greatly with the increasing duty cycle, but the melt fluctuation region is expanded with higher duty cycle, which accelerates the interior melt velocity and reduces the temperature gradient at the liquid-solid interface. However, PMF with overly high duty cycle has adverse effect on the melt convection and limited influence on the interior melt. A duty cycle of 20% to 50% is a reasonable range.

This paper can provide guiding significance for the setting of duty cycle parameters on DC casting under PMF.

There are few reports on the effect of PMF parameters during DC casting with applying PMF, especially for duty cycle, a parameter unique to PMF. The findings will be helpful for applying the external field of PMF on DC casting.