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This paper aims to propose an identification method based on monocular vision for cylindrical parts in cluttered scene, which solves the issue that iterative closest point (ICP) algorithm fails to obtain global optimal solution, as the deviation from scene point cloud to target CAD model is huge in nature.

The images of the parts are captured at three locations by a camera amounted on a robotic end effector to reconstruct initial scene point cloud. Color signatures of histogram of orientations (C-SHOT) local feature descriptors are extracted from the model and scene point cloud. Random sample consensus (RANSAC) algorithm is used to perform the first initial matching of point sets. Then, the second initial matching is conducted by proposed remote closest point (RCP) algorithm to make the model get close to the scene point cloud. Levenberg Marquardt (LM)-ICP is used to complete fine registration to obtain accurate pose estimation.

The experimental results in bolt-cluttered scene demonstrate that the accuracy of pose estimation obtained by the proposed method is higher than that obtained by two other methods. The position error is less than 0.92 mm and the orientation error is less than 0.86°. The average recognition rate is 96.67 per cent and the identification time of the single bolt does not exceed 3.5 s.

The presented approach can be applied or integrated into automatic sorting production lines in the factories.

The proposed method improves the efficiency and accuracy of the identification and classification of cylindrical parts using a robotic arm.

This paper aims to investigate the micro-plastic behavior of granular material in three-body friction interface and its effect on friction characteristics.

A numerical model of particle breakage in friction contact was constructed based on the discrete element method. The influence of friction pair working condition and internal bonding strength on the micro-plastic behavior of particulate matter was analyzed. A reciprocating linear tribometer was used to verify the simulation results.

The results show that when the granular materials are squeezed and sheared by the friction pair, a shear zone inclined to the left is gradually formed, which leads to particle breakage. The breakage of the particle leads to the reduction of load-bearing capacity and the increase of friction coefficient. Due to the differences in bond strength and friction pairs working conditions, the particle plastic behavior is divided into the following three states: elastic deformation, breakage and plastic rheology.

This study is helpful to understand the effect of the micro-plastic behavior of particles on the three-body friction characteristics.

We modified a basic dye, which carries a positive charge, by inducing an exchange with clay, and then analysed the results by using Fourier transform infrared (FT-IR) and ultraviolet-visible (UV-Vis) spectroscopy, X-ray diffraction (XRD) and thermogravimetric analysis (TGA). The intercalation of basic dye into clay modifies the thermal properties of the dye, and the dyes become more stable as more clay is added. The colour of the modified dyes does not change with the addition of more clay, although its absorption decreases, thereby conferring improved sunlight colour fastness on the modified dyes.

The aim of this research is to investigate the influence of low molecular weight chitosan (LWCS) on the dyeability of cotton fabrics. Various concentrations of hydrogen peroxide were used to degrade chitosan to LWCS, which was used to pretreat cotton fabrics under different conditions in order to determine its influence on subsequent acid dyeing of the fabrics. The results showed that the molecular weight of LWCS decreased with increasing concentration of hydrogen peroxide. Additionally, LWCS pretreatment of cotton fabric is beneficial for acid dyeing. The K/S values for fabric dyeing increased with a decrease in LWCS molecular weight and the concomitant increase in concentration; a concentration of 4% LWCS yielded the best result. The anti-bacterial properties of fabrics pretreated with LWCS were better than those pretreated with chitosan. The dye and anti-bacterial fastness after 20 washes were best for fabrics pretreated with LWCS.

The purpose of this paper is to devise novel methods for effectively reducing China’s coal mining accidents via analysis of the relation between coal mine safety production and social factors.

The variations and characteristics of the safety production for coal mines in China from 1949 to 2013 are studied via induction and statistical analysis of data from the perspective of mortality rate per million tons, raw coal output and death tolls. It is analyzed that the relationship between coal mine safety production level and social economic, safety investment via SPSS.

Analysis of the coal mine safety management evolution across the 64 years after the founding of China demonstrates that China’s coal mine safety management evolution is partitioned into four stages, and there is the coupling relation between coal mine safety production and structure the of coal industry, government supervision and safety investment. By discussing the similarity between China and America in coal mine safety management evolution, it is found that the rapid increase in the number of accidents during the transformation from agricultural to industrial society is not accidental.

The suggestions in this paper are helpful to improve the current safety situation in China’s coal mines and provide management experience to other coal mining countries.

Based on present and future socioeconomic development, it is proposed that the coal mine safety situation can be further enhanced by properly adjusting the structure of the coal industry, strengthening supervision and ensuring safety investment.

Information opacity in donation crowdfunding activities has constrained the healthy development of China’s public welfare activities. Addressing the trust crisis and enhancing public engagement warrants further investigation. This study aims to uncover the moderating effect of activity transparency by utilizing data from 1,029 donation crowdfunding projects on the Sina Weibo Public Welfare Social Platform. In this way, we seek to elucidate the impact of donation crowdfunding events on fundraising ability.

This study selects text complexity, number of supporters, creator experience, and social capital as explanatory variables; innovatively selects the number of updates of online crowdfunding activities and total reading volume as moderating variables; selects the number of shares of crowdfunding activities as a mediating variable; and constructs a moderated mediation multiple regression model for fundraising ability.

Our findings indicate that independent variables, such as text complexity, number of supporters, and social capital, can significantly affect the dependent variable, fundraising ability. However, creator experience does not influence fundraising ability. Furthermore, social interaction has a mediating effect, whereas activity transparency has a reverse moderating effect. These results indicate that social interaction can enhance the fundraising ability of donation crowdfunding events. However, with an increase in information transparency, the fundraising ability of social media decreases.

The originality of this research is in clarifying the internal factors affecting fundraising ability through induction, making bold assumptions, and focusing on how social media’s effective interaction and activity transparency will affect public welfare crowdfunding fundraising ability.

This research examines farmers’ cognitions to the policy and how such cognitions influence their intentions and behaviors of land transfer, with the implementation of the Three Rights Separation (TRS) policy.

Using data collected from the Beijing area, this research tests the relationship between farmers’ policy cognition and their intention/behavior through the mediation of their psychological constructs. Both Causal step test and Bootstrap test are adopted.

Farmers’ intention of land transfer is influenced by their cognition of the TRS policy. In this process, farmers’ psychological constructs play a mediating role between their policy cognition and their intentions of land transfer, thereby eventually influencing their behaviors. This research confirms that institutions are not exogenous and the policy is not wishful thinking from the government. Instead, any policies, even enacted by governmental authority, have to be internalized within target groups’ cognition to be implemented.

Land transfer deserves close attention since it is the direct aim of the TRS reform. In this regard, this paper, based on an institutional perspective, aims to extend our understanding on the incentives of land transfer. This research proposes a revised model of planned behavior and argues that farmers’ intention of land transfer is influenced by their cognition of the TRS policy. On one hand, this study is the first to examine farmers’ cognition formed through the implementation of the TRS policy. On the other hand, it reveals the path of how policy can finally influence farmers’ intentions and behaviors through shaping their cognitions and changing subjective perceptions, which enriches our understanding of the mechanism of how policy has a concrete impact on society.

Most previous thermal-mechanical modeling of cold-formed steel (CFS) walls did not consider the failure of screwed connections under fire conditions because of the limited data of such connections at elevated temperatures.

In this study, 285 steady-state tests are conducted on CFS screwed connections with single-layer gypsum plasterboard (GPB) and Bolivian magnesium board (BMB) sheathing at ambient and elevated temperatures. The failure of these connections is described as the breaking of the loaded sheathing edge.

For the BMB sheathing screwed connections, hydrochloric acid gas is generated and released above 300°C, and the shear strength becomes much less than that of the GPB sheathing screwed connection above 370°C. Hence, BMB may not be suitable for use as the face-layer sheathing of CFS walls but is still recommended to replace GPB as the base-layer sheathing. The major influencing parameters on the shear strength of screwed connections are identified as the type of sheathing material and the loaded sheathing edge distance.

Based on the previous and present test results, a unified expression for the residual shear strength of screwed connections with GPB and BMB is proposed at ambient and elevated temperatures with acceptable accuracy. It can be used as the basic input parameter of the numerical simulation of the CFS structures under fire conditions.