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Copyright of Transactions of the Chinese Society of Agricultural Engineering is the property of Chinese Society of Agricultural Engineering and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Shanxi Agricultural Sciences is the property of Shanxi Academy of Agricultural Sciences and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The ever-increasing span can be found in the single-pipe arch solar greenhouse in recent years. But the cross-section of the rods cannot be adjusted in real time. This study aims to ensure the structural Safety Issues in this case. The research object was taken as the 12m-span solar greenhouse with a flexible thermal insulation wall. A test example was selected as the solanaceous solar greenhouse in Beijing of China. An oval tube was used with a commonly-used section of 80 mm×30 mm×2.0 mm (Height×width×wall thickness). A ‘Midas-Gen finite element software’ was utilized to analyze the greenhouse hanging, and boundary conditions. Finally, the structural parameters were optimized, according to the national standard "Agricultural Greenhouse Structure Load Code" (GB/T 51183-2016) and "Agricultural Greenhouse Structure Design Standard" (GB/T 51424- 2022). The results show that the maximum stress was 1 146.7 N/mm2, when the crop load was suspended at two points and the column feet were hinged in the greenhouse. The position of the maximum stress was the hanging point on the rear wall. The crop load C was the main control load, and the average stress value was 445.4 N/mm2 at other positions. Therefore, the small number of hanging points and the large concentrated load at the hanging points were attributed to the extremely uneven distribution of the internal force of the arch frame. The structural parameters were optimized to increase the number of hanging points, in order to disperse and reduce the local concentrated load. As such, the peak value of concentrated stress was effectively reduced to improve the uniformity of the internal force distribution of the whole structure. Furthermore, the arrangement of hanging loads was also optimized to combine with the local reinforcement and adjustment of boundary conditions. The internal force of the structure was reasonably distributed to reduce the stress of the structural skeleton. Further research was recommended that: 1) The increasing hanging points of the crops can be expected to effectively reduce the peak value of internal force. Once the hanging points increased to the three-point type, the hanging load degenerated into a secondary control load, whereas, when increased to the four-point type, the crop load quit the control role. 2) The rest direction was the partial strengthening of weak parts. The rear wall was adjusted from a single tube to a lattice column, while the maximum stress was reduced by about 48%, indicating a more significant improvement. 3) The connection form of column feet was adjusted, when fixed the front and rear column feet of the solar greenhouse with the single-tube arch frame. Once the rear wall arch frame was adjusted to the lattice columns, the hinged form was used to optimize the front column foot. This finding can also provide a strong reference for the structural form and structural materials of flexible insulation wall oval tube single tube arch type solar greenhouse. [ABSTRACT FROM AUTHOR]

Copyright of Bulletin of the Chinese Academy of Sciences / Chung-kuo ko Hsueh Yuan Yuan Kan is the property of Institutes of Science & Development, Chinese Academy of Sciences and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The path programming of the unmanned ground vehicle（UGV） was studied under the framework of the deep Q-network（DQN） algorithm. To improve the exploration efficiency, the DQN algorithm was applied through discretization of the continuous state into the discrete state. To balance between exploration and exploitation, the Gaussian noise was added only in the output layer of the network, and a progressive reward function was designed. Finally, experiments were carried out in the Gazebo simulation environment. The simulation results show that, first, this strategy can quickly program a collision-free route from the initial point to the target point, and the convergence speed is significantly higher than those of the Q-learning algorithm, the DQN algorithm and the noisynet＿DQN algorithm; second, this strategy has the generalization ability about the initial point, the target point and the obstacles, as well as verified effectiveness and robustness. [ABSTRACT FROM AUTHOR]

In order to solve the problem of insufficient global information modeling of person re-recognition algorithm based on convolutional neural network， the limitation of convolution operation is analyzed， and an improved global-local two-branch person re-recognition algorithm based on Transformer is proposed. Firstly， the multi-headed self-attention mechanism which is embedded in the Resnet50 backbone network is optimized by relative position-coding. After that， the processed image is split into two parts on the global branch geometrically， and the ability of extracting the abstract features is enhanced by the Transformer’s global receptive field. On the local branch， the Layer_3 output is under the supervision of dimensionality reduction while the multi-scale pooling obtains richer local features. The experimental result shows that， on the Market-1501 and DukeMTMC-reID datasets， mAP/Rank-1 of the algorithm reaches 93.45%/95.61% and 88.79%/90.35%， respectively. Compared with the algorithm which is only based on convolutional neural network， higher accuracy is achieved. [ABSTRACT FROM AUTHOR]

Less shading of the steel skeleton has been the dominant structure of the Chinese solar greenhouse in recent years, due to the light structure of the single-tube arch center. The disciform arch center can hold more sections of the component, indicating the stronger carrying capacity in the same amount of steel, compares with the circular tube. Furthermore, the disciform arch center is a closed structure, compare with type C steel. The components shared a much stronger resistance to deformation. The disciform tube can be in the single arch center popular material, particularly for the current greenhouse with the light assemble structure. In this study, three groups were selected in the common spans of 8, 9, and 10m for the snow load in the Beijing region. The section size of the greenhouse and the form of load action was selected, according to the “Code for the design load of horticultural greenhouse structures” and “Code for the design of Chinese solar greenhouse”. The cross-sectional dimensions of the Chinese solar greenhouse with three spans were 100 mm40 mm5 mm, 100 mm 40 mm2.5 mm, 110 mm40 mm2.5 mm, where the flat oval pipe was used as the load-bearing arch. The spacing between the skeletons was 1.0 m, and the longitudinal support was adopted as a circular tube of φ25 mm×1.5 mm. The material of the skeleton was the ordinary carbon structural steel Q235. The design life of the Chinese solar greenhouse was considered as 10 years. Permanent loads were generated by the arches and permanent equipment, whereas, the variable loads mainly included a load of crop, snow, wind, roof live, and thermal insulation. The building was set as four types of attachment (consolidation with consolidation, hinge with hinge, consolidation with hinge, and hinge with consolidation), three types of span (8, 9, and 10 m), and two kinds of roof form (sharp roof ridge and round roof ridge), where the straining beam was set in different positions. A computational model was established to determine the influence of straining beam position on the single-tube arch center axial force, bending moment, and maximum stress ratio. The software (3D3S) was selected for the modeling operation in a wide range of applications for the rhino curve. The modeling accuracy was improved to import any section form. If the arch center was connected with the back wall, whatever the kind of attended mode, the straining beam was avoided, when the arch center connected with the base used the solid connection. When the arch center connected with the base used the hinge joint, the straining beam was set. In four connection modes, the stress ratio of the arch frame was the largest, which was hinged with the foundation and the back wall. The stress ratio of the arch frame was the smallest, which was hinged with the foundation and consolidated with the back wall. The connection between the arch and the foundation was hinged to consolidate the connection with the back wall in the engineering design. In this case, the tie rod was set more effectively. The roof straining beam presented the curve in the greenhouse with the different spans, when the arch center connected with the base use hinges, or with the backwall use hinges. The structural bearing force was required the greenhouse span of 9 m. Consequently, the roof form was a round arc without a straining beam, otherwise, the roof can be sharp with the straining beam. The findings can provide the theoretical support to design the oval-tube arch center of a single-tube Chinese solar greenhouse. [ABSTRACT FROM AUTHOR]

Most agricultural greenhouses generally present low structural rigidity, self-weight, and seismic response in recent years. The structure design also varies significantly in different locations, if the seismic effect is considered in the load combination. Therefore, this study aims to investigate the effect of seismic action on various greenhouse structure under a load combination in China. The glass greenhouse was also taken as the research object, particularly for the heaviest material of roof glazing in all greenhouses. Two regular and one irregular plane layouts of greenhouses were selected, according to the regulation of seismic action in the structure design. Midas Gen software was used to analyze the structure stress in the components. The load combinations were compared with or without the seismic action (remarked as class-e and class-a). The maximum stress ratio of components was set as the evaluation index, while, the seismic intensity was used as the variable from 7° (0.10g), 7° (0.15g), 8° (0.20g), 8° (0.30g) to 9° (0.40g). The results show that the greenhouse with the regular and irregular plane layouts performed the greater stress ratios under the load combination of class-a without considering the seismic action, when the seismic intensity was 7° (0.1g and 0.15g), indicating there was no controlling effect of seismic action. In the inner and side wall posts of the regular plane layout in the greenhouse structure, the stress ratio of load combination of class-e considering the seismic effect was already very close to that of class-a, when the seismic intensity reached 8° (0.20g). In some individual corner posts of irregular plane layout in the greenhouse structure, the maximum stress ratio of load combination of class-e (0.31) was slightly larger than that of class-a (0.29). In the individual structural components of the regular plane layout in the greenhouse, the maximum stress ratio of load combination of class-e (0.36) was greater than that of class-a (0.29), when the seismic intensity reached 8° (0.30g). It infers that the maximum stress ratio was controlled by the seismic action. The seismic intensity was also combined with the smallest wind load in the study areas. Consequently, the areas of 8° (0.20g) and below cannot be considered for the seismic combination, whereas the areas of 8° (0.30g) and above were preferred in the structural design of the glass greenhouse. Additionally, the seismic action cannot be considered in the load combination, particularly in the plastic structures, including gutter-connected plastics, solar and plastic tunnels. The finding can provide a sound theoretical basis to implement the structural design of a glass greenhouse. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Clinical Nursing in Practice is the property of Journal of Clinical Nursing in Practice (Editorial Board, Shanghai Jiao Tong University Press) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Structure of solid-belly skeleton is commonly used for the solar greenhouses with light loading or narrow span due to the small section stiffness. Generally, a suitable support can be set at a certain position of south roof in a solar greenhouse, aiming to provide an economically feasible technical solution to the improvement on the safety of entire skeleton system. In this study, three types of solar greenhouse with a common span in Beijing were selected as research examples, and then to calculate the section parameter of greenhouses and the loading form, according to greenhouse design code. The main purpose of this study is to determine the impact of setting position for south roof support point on the framework safety, and thereby to obtain the optimal setting region of support point. Prior to the calculation, it needed to assume that a support point was set on the south roof skeleton of a solar greenhouse, and the position of support point can be changed along the south roof skeleton at a relatively fixed distance (about 50cm). A Midas Gen software was then used to calculate the width-to-thickness ratio, deflection, and safety factor of south roof skeleton in the solar greenhouse under 49 supporting conditions, and 255 load combinations. The results of south roof skeleton for the 8, 9, 10 m span solar greenhouse were the width-to-thickness ratios of 33, 38, 43, and the maximum deflection of 15.13mm, 14.69mm, 18.5mm, under different supporting conditions and load combinations, for the section size as 70502.0, 80602.0, 90602.0, respectively. Compared with the greenhouse design codes, all obtained data demonstrated that the skeleton structure can meet the required level of safety and stability, as the support position of south roof changed in this case. Based on the above analysis of deflection deformation and safety factor on the south roof skeleton with different support positions, it was founded that the change of support positions can make a significant impact on the safety of a south roof skeleton in a greenhouse. A feature of isolated peak curve can be used to describe the variation of deflection deformation and safety factor with the position of support points. Furthermore, the curve laws were basically consistent for three kinds of span greenhouse. Specifically, the arch deflection changed slightly, when the support point shifted from the foot to about 30% span of south roof. When the support point moved from 30% span to the ridge position, the arch deflection changed greatly, showing a trend of first decreasing and then increasing. The minimum deflection occurred, when the position of support point were set at 51%, 66%, and 59% of south roof for the 8, 9, 10 m span solar greenhouse, respectively. In a safety factor, the maximum appeared, when the position of support point were set at 51%, 72% and 71% of south roof for the 8, 9, 10m span solar greenhouse, respectively. The main conclusions can be obtained as follow: (1) By setting permanent support or temporary support at appropriate position on the south roof of solar greenhouse, the deflection deformation of arch frame can be effectively reduced, and the structural safety of framework can be significantly improved; (2) In the 8, 9, 10 m span solar greenhouse, the influence of relative support distance on deflection deformation and safety factor can be basically consistent; (3) The optimal support setting region was on the 51%-72% of the south roof in a greenhouse. The findings can provide a sound theoretical guidance to develop a novel solid-belly skeleton system, and thereby to effectively prevent some damage to solar greenhouse. [ABSTRACT FROM AUTHOR]