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This paper aims to develop a new robotic ultrasound system for spine imaging with more anthropomorphic scanning manipulation in comparison with previously reported techniques.

The system evaluates the imaging quality of ultrasound (US) B-scans by detecting vertebral landmarks and groups the images with relatively low quality into several sub-optimal types. By imitating the scanning skills of sonographers, the authors defined a set of adjustment strategies for certain sub-optimal types. In this way, the robot can recollect the US images with high quality by adaptively adjusting the pose of the probe like a sonographer.

The results from phantom experiments and in vivo experiments showed that the proposed method could improve the quality of B-scans during the scanning. The 3 D US volume reconstruction has also verified the feasibility of the proposed method.

This paper demonstrates how to adapt a robotic spinal ultrasound scanning using a preliminary anthropomorphic approach.

This study aims to investigate the relationships between the perceived neighborhood walkable environment (PNWE), neighborhood interaction (NI) and residents’ mental health, with a focus on examining differences among residents of different age groups.

Using an electronic survey questionnaire, data on PNWE, NI and mental health were collected from 1,159 residents across 205 communities in Shanghai, China. Our study utilized a structural equation modeling (SEM), employing the maximum likelihood estimation method. The structural equation model was fitted using the MPLUS software.

The mental health of young and middle-aged adults is generally poor, and they are at higher risk of depression than children and older adults. The effects of PNWE and NI on the mental health of residents varied among different age groups. As residents get older, their mental health is more affected by the PNWE. In addition, the influence of the PNWE on children and older adults’ mental health is direct and not mediated by NI. For young and middle-aged adults, the influence of the PNWE on their mental health needs to be mediated by NI.

This study marks the first examination of the relationship between PNWE, NI and mental health among different age groups of residents in China. The findings of this research can assist policymakers in gaining a deeper understanding of the underlying mechanisms by which PNWE affects mental health. Furthermore, it can contribute to the development of more targeted walkable environment designs aimed at enhancing mental health among various age groups.

The purpose of this paper is to improve the dimensional accuracy of inclined thin-walled parts fabricated by laser direct metal deposition (DMD) under an open-loop control system.

In this study, a novel method of the adaptive slicing method and DMD process with feedback adjustment of deposition height has been developed to successively fabricate complex inclined thin-walled square tube elbow parts. The defocus amount was used as a variable to the matching between the deposition thickness and the adaptive slicing height.

The low relative error of dimensional accuracy between experimental and designed parts shows that the matching of the single-layer deposition thickness and the adaptive slicing height can be realized by optimizing the defocusing amount. The negative feedback of the thin-wall part height can be achieved when the defocus amount and the z-axis increment are less than deposition thickness. The improvement of dimensional accuracy of inclined thin-walled parts is also attributed to the optimized scanning strategy.

The slicing method and deposition process can provide technical guidance for other additive manufacturing (AM) systems to fabricate metal thin-walled parts with high dimensional accuracy because the feedback control of deposition height can be realized only by the optimized process.

This study provides a novel adaptive slice method and corresponding the deposition process, and expands the slicing method of AM metal parts.

The purpose of this paper is to study the influence of the porous structure on the maximum stress and modulus of elasticity of the specimens which are fabricated by rapid prototypes. According to the experimental results, modify the theoretical formula of elastic modulus.

The Objet Eden 250 was used to prepare the Vero White photosensitive resin samples with different porosity (ranges from 25 to 65 per cent) and different pore structures. The mechanical properties of different samples were numerically simulated and the formulas of the modulus of elasticity were established. Through the compression test, the performance of the specimen is compared and analyzed, and the theoretical elastic modulus formula is optimized.

With the increase of porosity, the maximum stress of honeycomb structure specimens decreases. The maximum stress of the honeycomb structure specimen with circular pore shape is higher than the hexagon cross-section while the hexahedron and octahedron structure are the arms (wall thickness between pores) with a square cross-section. The error comparison between the modulus of elasticity before and after the structure models regression analysis shows that after the regression analysis, the error of theoretical value and the actual value is between 0 and 14 per cent which is lower than the value before the regression analysis which was between 5 and 27 per cent.

The paper obtains rules of the influence of different porous structures which were fabricated by the Vero White photosensitive resin material on mechanical properties and higher prediction accuracy formula of elastic modulus. The conclusions provide a theoretical basis for Northeastern University, China, to reduce mass and mechanical properties prediction of load-bearing parts.