Real-Time Detection and Instance Segmentation of Strawberry in Unstructured Environment

The real-time detection and instance segmentation of strawberries constitute fundamental components in the development of strawberry harvesting robots.Real-time identification of strawberries in an unstructured envi-ronment is a challenging task.Current instance segmentation algorithms for strawberries suffer from issues such as poor real-time performance and low accuracy.To this end,the present study proposes an Efficient YOLACT(E-YOLACT)algorithm for strawberry detection and segmentation based on the YOLACT framework.The key enhancements of the E-YOLACT encompass the development of a lightweight attention mechanism,pyramid squeeze shuffle attention(PSSA),for efficient feature extraction.Additionally,an attention-guided context-feature pyramid network(AC-FPN)is employed instead of FPN to optimize the architecture’s performance.Furthermore,a feature-enhanced model(FEM)is introduced to enhance the prediction head’s capabilities,while efficient fast non-maximum suppression(EF-NMS)is devised to improve non-maximum suppression.The experimental results demonstrate that the E-YOLACT achieves a Box-mAP and Mask-mAP of 77.9 and 76.6,respectively,on the custom dataset.Moreover,it exhibits an impressive category accuracy of 93.5%.Notably,the E-YOLACT also demonstrates a remarkable real-time detection capability with a speed of 34.8 FPS.The method proposed in this article presents an efficient approach for the vision system of a strawberry-picking robot.

An Efficient Method for Identifying Lower Limb Behavior Intentions Based on Surface Electromyography

Surface electromyography(sEMG)is widely used for analyzing and controlling lower limb assisted exoskeleton robots.Behavior intention recognition based on sEMG is of great significance for achieving intelligent prosthetic and exoskeleton control.Achieving highly efficient recognition while improving performance has always been a significant challenge.To address this,we propose an sEMG-based method called Enhanced Residual Gate Network(ERGN)for lower-limb behavioral intention recognition.The proposed network combines an attention mechanism and a hard threshold function,while combining the advantages of residual structure,which maps sEMG of multiple acquisition channels to the lower limb motion states.Firstly,continuous wavelet transform(CWT)is used to extract signals features from the collected sEMG data.Then,a hard threshold function serves as the gate function to enhance signals quality,with an attention mechanism incorporated to improve the ERGN’s performance further.Experimental results demonstrate that the proposed ERGN achieves extremely high accuracy and efficiency,with an average recognition accuracy of 98.41%and an average recognition time of only 20 ms-outperforming the state-of-the-art research significantly.Our research provides support for the application of lower limb assisted exoskeleton robots.

Application of Pelvic Peritoneum Closure Combined with Extraperitoneal Colostomy in Laparoscopic Surgery for Low Rectal Cancer

Background:In the treatment of colorectal cancer,laparoscopic surgery has seen a significant amount of success.Reducing the risk of postoperative complications and improving patients’quality of life can be accomplished by appropriately employing pelvic peritoneal repair and sigmoid colostomy when appropriate.Objective:To compare fusion closure of pelvic peritoneum combined with extraperitoneal colostomy with non-closure of pelvic peritoneum combined with intraperitoneal colostomy in patients with low rectal cancer who had permanent colostomy.Methods:Low rectal cancer patients admitted to Hengshui People’s Hospital for permanent colostomy were evaluated.The participants were divided into two groups:an observation and a control group.All 30 cases in the observation group underwent pelvic peritoneum closure and extraperitoneal colostomy,while the other 30 cases in the control group underwent intraperitoneal colostomy.The C-reactive protein(CRP)levels of the participants in both groups were evaluated for 6 months to 2 years(24 h before,24 h after,48 h after,96 h after surgery).Results:Comparing the colostomy operative time,time to first passage of flatus postoperatively,time to first defecation postoperatively,length of hospital stay,laboratory indicators,stoma-related complications,colostomy function,etc.,the colostomy operative time significantly differed between the two groups(P<0.05);the observation group did considerably better than the control group in terms of stoma-related complications and bowel movement control 6 months after surgery(P<0.05);and although serum CRP levels increased in both groups 48 h after surgery,the difference was significant(P<0.05).Conclusion:Extraperitoneal colostomy can improve the quality of life of patients with permanent stoma and reduce the occurrence of stoma-related complications.Thus,this technique is worthy of promotion in clinical practice.

非农就业行为中普通话的提质效果及机制研究——基于CLDS微观数据的实证分析

非农就业行为包括是否非农就业和非农就业质量。本文阐释了普通话作为特殊的技能偏向性人力资本影响非农就业行为的作用机制,并使用2012、2014和2016年中国劳动力动态调查(CLDS)混合横截面数据,研究目前中国农村劳动力的普通话能力在多大程度上对其非农就业行为产生影响。运用2SLS、IV-Probit和Heckman等方法得出以下结论:普通话能力提高了农村劳动力从事非农就业的概率及其非农就业质量,同时,这一影响存在着边际报酬递增的趋势;随着性别、年龄、区域、就业形式和受雇行业的不同,上述影响具有显著差异;普通话对人力资本影响非农就业行为的正向调节效应显著,即普通话能力的提升促进了人力资本的偏向性技术进步,这为解释我国城乡收入差距提供了新的证据。

Transient thermo-mechanical analysis for bimorph soft robot based on thermally responsive liquid crystal elastomers

Thermally responsive liquid crystal elastomers (LCEs) hold great promise in applications of soft robots and actuators because of the induced size and shape change with temperature. Experiments have successfully demonstrated that the LCE based bimorphs can be effective soft robots once integrated with soft sensors and thermal actuators. Here, we present an analytical transient thermo-mechanical model for a bimorph structure based soft robot, which consists of a strip of LCE and a thermal inert polymer actuated by an ultra-thin stretchable open-mesh shaped heater to mimic the unique locomotion behaviors of an inchworm. The coupled mechanical and thermal analysis based on the thermo-mechanical theory is carried out to underpin the transient bending behavior, and a systematic understanding is therefore achieved. The key analytical results reveal that the thickness and the modulus ratio of the LCE and the inert polymer layer dominate the transient bending deformation. The analytical results will not only render fundamental understanding of the actuation of bimorph structures, but also facilitate the rational design of soft robotics.

The biogenesis and biological roles of tRNA-derived short RNAs

In recent years, next-generation sequencing (NGS) technologies targeting the microRNA (miRNA)transcriptome revealed the existence of tRNA-derived short RNAs: tRNA halves (tiRNAs) and tRNA-derived fragments (tRFs). These small RNAs represent a novel type of small non-coding RNAs (sncRNAs), which are heterogeneous in size, nucleotide composition and biogenesis, and have been suggested to be involved in translation, cell proliferation, priming of viral reverse transcriptases, regulation of gene expression, modulation of the DNA damage response, tumor suppression and neurological disorders. Herein, we review the mechanism of their biogenesis and discuss in detail the regulatory roles they play in cell physiology. We also point out that the biological function of tRNA-derived short RNAs will be understood better as research moves forward, and that this knowledge will find its way into clinical application in the near future.

Transfer printing techniques for flexible and stretchable inorganic electronics

Transfer printing is an emerging deterministic assembly technique for micro-fabrication and nano-fabrication,which enables the heterogeneous integration of classes of materials into desired functional layouts.It creates engineering opportunities in the area of flexible and stretchable inorganic electronics with equal performance to conventional wafer-based devices but the ability to be deformed like a rubber,where prefabricated inorganic semiconductor materials or devices on the donor wafer are required to be transfer-printed onto unconventional flexible substrates.This paper provides a brief review of recent advances on transfer printing techniques for flexible and stretchable inorganic electronics.The basic concept for each transfer printing technique is overviewed.The performances of these transfer printing techniques are summarized and compared followed by the discussions of perspectives and challenges for future developments and applications.

Characteristics and source attribution of PM2.5 during 2016 G20 Summit in Hangzhou: Efficacy of radical measures to reduce source emissions

A field campaign was conducted to study the PM2.5 and atmospheric gases and aerosol’s components to evaluate the efficacy of radical measures implemented by the Chinese government to improve air quality during the 2016 G20 Summit in Hangzhou China.The lower level of PM2.5(32.48±11.03μg/m3)observed during the control period compared to precontrol and post-control periods showed that PM2.5 was alleviated by control policies.Based on the mass concentrations of particulate components,the emissions of PM2.5 from local sources including fossil fuel,coal combustion,industry and construction were effectively reduced,but non-exhaust emission was not reduced as effectively as expected.The accumulation of SNA(SO42-,NO3-,NH4+)was observed during the control period,due to the favourable synoptic weather conditions for photochemical reactions and heterogeneous hydrolysis.Because of transboundary transport during the control period,air masses from remote areas contributed significantly to local PM2.5.Although,secondary organic carbon(OCsec)exhibited more sensitivity than primary organic carbon(OCpri)to control measures,and the increased nitrogen oxidation ratio(NOR)implied the regional transport of aged sec-ondary aerosols to the study area.Overall,the results from various approaches revealed that local pollution sources were kept under control,indicating that the implementation of mitigation measures were helpful in improving the air quality of Hangzhou during G20 summit.To reduce ambient levels of PM2.5 further in Hangzhou,regional control policies may have to be taken so as to reduce the impact of long-range transport of air masses from inland China.