Hepatocellular carcinoma presents with three distinct immune phenotypes,including immune-desert,immune-excluded,and immune-inflamed,indicating various treatment responses and prognostic outcomes.The clinical applicati...Hepatocellular carcinoma presents with three distinct immune phenotypes,including immune-desert,immune-excluded,and immune-inflamed,indicating various treatment responses and prognostic outcomes.The clinical application of multi-omics parameters is still restricted by the expensive and less accessible assays,although they accurately reflect immune status.A comprehensive evaluation framework based on“easy-to-obtain”multi-model clinical parameters is urgently required,incorporating clinical features to establish baseline patient profiles and disease staging;routine blood tests assessing systemic metabolic and functional status;immune cell subsets quantifying subcluster dynamics;imaging features delineating tumor morphology,spatial configuration,and perilesional anatomical relationships;immunohistochemical markers positioning qualitative and quantitative detection of tumor antigens from the cellular and molecular level.This integrated phenomic approach aims to improve prognostic stratification and clinical decision-making in hepatocellular carcinoma management conveniently and practically.展开更多
The internal flow fields within a three-dimensional inward-tunning combined inlet are extremely complex,especially during the engine mode transition,where the tunnel changes may impact the flow fields significantly.To...The internal flow fields within a three-dimensional inward-tunning combined inlet are extremely complex,especially during the engine mode transition,where the tunnel changes may impact the flow fields significantly.To develop an efficient flow field reconstruction model for this,we present an Improved Conditional Denoising Diffusion Generative Adversarial Network(ICDDGAN),which integrates Conditional Denoising Diffusion Probabilistic Models(CDDPMs)with Style GAN,and introduce a reconstruction discrimination mechanism and dynamic loss weight learning strategy.We establish the Mach number flow field dataset by numerical simulation at various backpressures for the mode transition process from turbine mode to ejector ramjet mode at Mach number 2.5.The proposed ICDDGAN model,given only sparse parameter information,can rapidly generate high-quality Mach number flow fields without a large number of samples for training.The results show that ICDDGAN is superior to CDDGAN in terms of training convergence and stability.Moreover,the interpolation and extrapolation test results during backpressure conditions show that ICDDGAN can accurately and quickly reconstruct Mach number fields at various tunnel slice shapes,with a Structural Similarity Index Measure(SSIM)of over 0.96 and a Mean-Square Error(MSE)of 0.035%to actual flow fields,reducing time costs by 7-8 orders of magnitude compared to Computational Fluid Dynamics(CFD)calculations.This can provide an efficient means for rapid computation of complex flow fields.展开更多
The shear behavior of rock joints is important in solving practical problems of rock mechanics. Three group rock joints with different morphologies are made by cement mortar material and a series of CNL(constant norma...The shear behavior of rock joints is important in solving practical problems of rock mechanics. Three group rock joints with different morphologies are made by cement mortar material and a series of CNL(constant normal loading) shear tests are performed. The influences of the applied normal stress and joint morphology to its shear strength are analyzed. According to the experimental results, the peak dilatancy angle of rock joint decreases with increasing normal stress, but increases with increasing roughness. The shear strength increases with the increasing normal stress and the roughness of rock joint. It is observed that the modes of failure of asperities are tensile, pure shear, or a combination of both. It is suggested that the three-dimensional roughness parameters and the tensile strength are the appropriate parameter for describing the shear strength criterion. A new peak shear criterion is proposed which can be used to predict peak shear strength of rock joints. All the used parameters can be easily obtained by performing tests.展开更多
Objective To establish three-dimensional phenotyping system for congenital heart disease in mouse and to lay a foundation for the study of phenotype identification and mechanism of congenital heart disease.Methods Twe...Objective To establish three-dimensional phenotyping system for congenital heart disease in mouse and to lay a foundation for the study of phenotype identification and mechanism of congenital heart disease.Methods Twelve SPF C57BL/6 J wild type pregnant mice(8-10 week-old)were randomly divided into control group(n=6)and experimental group(n=6).展开更多
Gobi spans a large area of China,surpassing the combined expanse of mobile dunes and semi-fixed dunes.Its presence significantly influences the movement of sand and dust.However,the complex origins and diverse materia...Gobi spans a large area of China,surpassing the combined expanse of mobile dunes and semi-fixed dunes.Its presence significantly influences the movement of sand and dust.However,the complex origins and diverse materials constituting the Gobi result in notable differences in saltation processes across various Gobi surfaces.It is challenging to describe these processes according to a uniform morphology.Therefore,it becomes imperative to articulate surface characteristics through parameters such as the three-dimensional(3D)size and shape of gravel.Collecting morphology information for Gobi gravels is essential for studying its genesis and sand saltation.To enhance the efficiency and information yield of gravel parameter measurements,this study conducted field experiments in the Gobi region across Dunhuang City,Guazhou County,and Yumen City(administrated by Jiuquan City),Gansu Province,China in March 2023.A research framework and methodology for measuring 3D parameters of gravel using point cloud were developed,alongside improved calculation formulas for 3D parameters including gravel grain size,volume,flatness,roundness,sphericity,and equivalent grain size.Leveraging multi-view geometry technology for 3D reconstruction allowed for establishing an optimal data acquisition scheme characterized by high point cloud reconstruction efficiency and clear quality.Additionally,the proposed methodology incorporated point cloud clustering,segmentation,and filtering techniques to isolate individual gravel point clouds.Advanced point cloud algorithms,including the Oriented Bounding Box(OBB),point cloud slicing method,and point cloud triangulation,were then deployed to calculate the 3D parameters of individual gravels.These systematic processes allow precise and detailed characterization of individual gravels.For gravel grain size and volume,the correlation coefficients between point cloud and manual measurements all exceeded 0.9000,confirming the feasibility of the proposed methodology for measuring 3D parameters of individual gravels.The proposed workflow yields accurate calculations of relevant parameters for Gobi gravels,providing essential data support for subsequent studies on Gobi environments.展开更多
Sometimes endometrial polyps,submucosal myomas,and endometrial cancer show similar findings under ultrasonography.The aim of this study was to assess the antidiastole value of blood flow parameters using three-dimensi...Sometimes endometrial polyps,submucosal myomas,and endometrial cancer show similar findings under ultrasonography.The aim of this study was to assess the antidiastole value of blood flow parameters using three-dimensional(3D)power Doppler ultrasonography angiography(PDA)between endometrial cancer and uterine parenchyma lumps.The data of the blood flow indices in 3D-PDA including the vascularization index(VI),flow index(FI),and vascularization flow index(VFI)in 40 patients with endometrial cancer and 41 patients with uterine parenchyma lumps(endometrial polyps and submucosal myomas)were retrospectively analysed and compared utilizing Virtual Organ Computer-aided AnaLysis(VOCAL)software.The results showed that all the blood flow parameters(VI,FI,VFI)were significantly higher in women with endometrial cancer than in those with uterine parenchyma lumps(P<0.001).The area under the curve of ROC of VI,FI,and VFI was 0.98,0.84,and 0.97,respectively.Thus,the best predictor of endometrial carcinoma was VI with a sensitivity of 97.0% and a specificity of 91.0%.The optimal cutoff value of VI was 4.06%.Our data demonstrated that all of the blood flow signal parameters(including VI,FI,and VFI)in 3D power Doppler ultrasonography had significant antidiastole values between endometrial cancer and uterine parenchyma lumps to assist clinicians in properly diagnosing patients.展开更多
It is important to calibrate micro-parameters for applying partied flow code(PFC)to study mechanical characteristics and failure mechanism of rock materials.Uniform design method is firstly adopted to determine the mi...It is important to calibrate micro-parameters for applying partied flow code(PFC)to study mechanical characteristics and failure mechanism of rock materials.Uniform design method is firstly adopted to determine the microscopic parameters of parallel-bonded particle model for three-dimensional discrete element particle flow code(PFC3D).Variation ranges of microscopic of the microscopic parameters are created by analyzing the effects of microscopic parameters on macroscopic parameters(elastic modulus E,Poisson ratio v,uniaxial compressive strengthσc,and ratio of crack initial stress to uniaxial compressive strengthσci/σc)in order to obtain the actual uniform design talbe.The calculation equations of the microscopic and macroscopic parameters of rock materials can be established by the actual uniform design table and the regression analysis and thus the PFC3D microscopic parameters can be quantitatively determined.The PFC3D simulated results of the intact and pre-cracked rock specimens under uniaxial and triaxial compressions(including the macroscopic mechanical parameters,stress−strain curves and failure process)are in good agreement with experimental results,which can prove the validity of the calculation equations of microscopic and macroscopic parameters.展开更多
To explore the relation of maize grain texture and phenotypic traits with grain thin-layer drying rate,we observed the ultra-structure of maize grain,and tested three traits about the maize grain texture and four phen...To explore the relation of maize grain texture and phenotypic traits with grain thin-layer drying rate,we observed the ultra-structure of maize grain,and tested three traits about the maize grain texture and four phenotypic traits.The vitreous part percentage was different（P〈0.05） among different maize inbred lines.There was a significant relationship between the drying rate with grain texture and phenotypic traits.Main factors that influenced the drying rate were different during different drying stages.New results observed that empirical constants（k and N） in drying equation were different for seed of the 30 inbred lines of maize.The k of simplified diffusion equation and N of page equation were significantly influenced by both grain texture and phenotypic traits.These results could be used as guideline parameters for drying maize seeds having different grain characteristics during different drying stages.展开更多
This paper conducts a trade-off between efficiency and accuracy of three-dimensional(3 D)shape measurement based on the triangulation principle,and introduces a flying and precise 3 D shape measurement method based on...This paper conducts a trade-off between efficiency and accuracy of three-dimensional(3 D)shape measurement based on the triangulation principle,and introduces a flying and precise 3 D shape measurement method based on multiple parallel line lasers.Firstly,we establish the measurement model of the multiple parallel line lasers system,and introduce the concept that multiple base planes can help to deduce the unified formula of the measurement system and are used in simplifying the process of the calibration.Then,the constraint of the line spatial frequency,which maximizes the measurement efficiency while ensuring accuracy,is determined according to the height distribution of the object.Secondly,the simulation analyzing the variation of the systemic resolution quantitatively under the circumstance of a set of specific parameters is performed,which provides a fundamental thesis for option of the four system parameters.Thirdly,for the application of the precision measurement in the industrial field,additional profiles are acquired to improve the lateral resolution by applying a motor to scan the 3 D surface.Finally,compared with the line laser,the experimental study shows that the present method of obtaining 41220 points per frame improves the measurement efficiency.Furthermore,the accuracy and the process of the calibration are advanced in comparison with the existing multiple-line laser and the structured light makes an accuracy better than 0.22 mm at a distance of 956.02 mm.展开更多
Three-dimensional sand printing(3DSP)is widely applied in sand mold fabrication.In this study,the effects of printing parameters including the resolution of printehead holes,activator content,layer thickness,and recoa...Three-dimensional sand printing(3DSP)is widely applied in sand mold fabrication.In this study,the effects of printing parameters including the resolution of printehead holes,activator content,layer thickness,and recoating speed on the tensile and bending strengths,gas evolution,and loss-on-ignition(LOI)of 3DSP samples were investigated by changing single parameter,and the dimension deviation was also measured.As the resolution increases,the tensile strength,bending strength,gas evolution,LOI,and deviations at X-and Y-axis directions decrease gradually while the deviation at Z-axis direction firstly increases and then deceases.The gas evolution and LOI drops by 13.02%and 8.13%respectively,but the strength only reduces by 2.2% when the resolution increases from 0.08 mm to 0.09 mm.The strengths of samples rise at first and then decline while the gas evolution and LOI rise gradually with the increasing activator content or recoating speed.The activator content is found to have little effect on the gas evolution as the activator increases from 0.14%to 0.34%,the gas evolution is increased by 7.3%which is far less than the LOI increment of 24.1%.As the layer thickness increases,the tensile and bending strengths firstly rise and then drop while gas evolution and LOI descend.Under the optimal printing parameters of 0.09 mm resolution,0.18%activator,-10.28 mm layer thickness and 160 mm·s^(-1) recoating speed,the tensile strengths for X-sample and Y-sample are 1.48 MPa and 1.37 MPa,the bending strengths are 1.84 MPa and 1.75 MPa,the gas evolution and LOI are-19.62 mL·g^(-1) and 1.92%,respectively.展开更多
In this paper, the axial-flux permanent magnet driver is modeledand analyzed in a simple and novel way under three-dimensional cylindricalcoordinates. The inherent three-dimensional characteristics of the deviceare co...In this paper, the axial-flux permanent magnet driver is modeledand analyzed in a simple and novel way under three-dimensional cylindricalcoordinates. The inherent three-dimensional characteristics of the deviceare comprehensively considered, and the governing equations are solved bysimplifying the boundary conditions. The axial magnetization of the sectorshapedpermanent magnets is accurately described in an algebraic form bythe parameters, which makes the physical meaning more explicit than thepurely mathematical expression in general series forms. The parameters of theBessel function are determined simply and the magnetic field distribution ofpermanent magnets and the air-gap is solved. Furthermore, the field solutionsare completely analytical, which provides convenience and satisfactoryaccuracy for modeling a series of electromagnetic performance parameters,such as the axial electromagnetic force density, axial electromagnetic force,and electromagnetic torque. The correctness and accuracy of the analyticalmodels are fully verified by three-dimensional finite element simulations and a15 kW prototype and the results of calculations, simulations, and experimentsunder three methods are highly consistent. The influence of several designparameters on magnetic field distribution and performance is studied and discussed.The results indicate that the modeling method proposed in this papercan calculate the magnetic field distribution and performance accurately andrapidly, which affords an important reference for the design and optimizationof axial-flux permanent magnet drivers.展开更多
Accurate and rapid wheat morphology reconstruction and trait collection are essential for selecting varieties,scientific cultivation,and precise management.A single perspective is limited by environmental obstructions...Accurate and rapid wheat morphology reconstruction and trait collection are essential for selecting varieties,scientific cultivation,and precise management.A single perspective is limited by environmental obstructions,hindering the collection of high-throughput phenotype data for wheat plants.Therefore,a rapid reconstruction method of multi-view threedimensional point cloud is proposed to realize the high-throughput and accurate identification of wheat phenotype.Firstly,taking wheat at the tillering stage as the experimental object,a multi-view acquisition system based on a RealSense sensor was constructed,and the point cloud data of wheat were obtained from 16 views.Secondly,a joint photometric and geometric objective was optimized,and space location was registered by colored Point Cloud Registration(colored)and Iterative Closest Point(ICP)algorithms.Furthermore,the Multiple View Stereo(MVS)algorithm was used to combine the depth image,RGB image,and spatial position obtained by coarse registration to enable the fine registration of multi-viewpoint clouds.Compared with the traditional Structure From Motion(SFM)-MVS algorithm,our proposed method is much faster,with an average reconstruction time of 33.82 s.Moreover,the wheat plant height,leaf length,leaf width,leaf area,and leaf angle of wheat were calculated based on the three-dimensional point cloud of the wheat plant.The experimental results showed that the determination coefficients of the method are 0.996,0.958,0.956,0.984,and 0.849,respectively.Finally,phenotypic information such as compact degree,convex hull volume,and average leaf area of different wheat varieties was analyzed and identified,proving that the method could capture the phenotypic differences between varieties and individuals.The proposed method provides a rapid approach to quantify wheat phenotypic traits,aiding breeding,scientific cultivation,and environmental management.展开更多
In order to obtain the phenotypic parameters of apple quickly and accurately,which were commonly used as the basis of fruit sorting,a fast estimation method of apple phenotypic parameters based on three-dimensional(3D...In order to obtain the phenotypic parameters of apple quickly and accurately,which were commonly used as the basis of fruit sorting,a fast estimation method of apple phenotypic parameters based on three-dimensional(3D)reconstruction was proposed in this study.In this study,a three-dimensional model was constructed to estimate the phenotypic parameters of apple,such as volume,height,diameter,and fruit shape index.Firstly,an image acquisition system was built to capture sequence images of fruit with a binocular stereo vision system,and the images were extracted and matched using the Accelerated-KAZE algorithm to create the point cloud data.Secondly,the point cloud data were matched with the algorithm of Iterative Closest Point to establish a whole model of apple,and the surface reconstruction model of fruit was obtained by constructing irregular triangulation network.Finally,the apple phenotypic parameters were calculated by means of segmentation,surface complement and integral of the fruit model.Total of 200 apples were used as samples in the experiment.By this method,the phenotypic parameters of the apples were estimated based on their 3D reconstruction model,and the linear regression analysis was carried out between the estimated values and the real values.The results showed that R2 of the linear regression fitting of each parameter was higher than 0.90.Among them,the fitting of volume was the best with R2 of 0.97.In addition,the average errors of apple volume,height,fruit shape index,maximum diameter D and minimum diameter d were 8.73 cm3,1.43 mm,1.28%,0.90 mm,and 1.23 mm,respectively.According to the Chinese national standard of“fresh Apple”,the average error of the estimated result is within the range of allowable error.It indicates that the method of apple phenotypic parameter estimation based on 3D reconstruction has a high accuracy and practicability,and it can be used as the support for fruit sorting.展开更多
The measurement of banana pseudo-stem phenotypic parameters is a critical way to evaluate the growth status of bananas,and it can provide essential data support for mechanized cultivation operations such as fertilizat...The measurement of banana pseudo-stem phenotypic parameters is a critical way to evaluate the growth status of bananas,and it can provide essential data support for mechanized cultivation operations such as fertilization and pesticide application.Existing studies mainly measure the diameter of banana pseudo-stem as its phenotypic parameter.The banana pseudo-stem cross section was closer to an ellipse other than a standard circle,so the diameter parameter cannot adequately represent the phenotypic characteristics of the banana plant.In this study,an automatic measuring device for banana pseudo-stem phenotypic parameters was developed.The device,which integrates three different types of sensors:a laser ranging sensor,a rotary encoder,and a digital camera,were used to obtain the point cloud and image data of banana pseudo-stem.A K-means point clouds clustering algorithm based on Euclidean distance was proposed.The point cloud of banana pseudo-stem was identified and extracted.A three-dimensional reconstruction algorithm based on the ellipse model was also proposed.The three-dimensional contour of the pseudo-stem was calculated to obtain three types of phenotypic parameters:the long axis length,the short axis length,and the perimeter.Further,a synchronous trigger image acquisition mechanism was used to take pictures of pseudo-stems during measurement.It can be utilized for manual assessment of the growth status of the banana.Field experimental results showed that the three banana phenotypic parameters had a high correlation with the manual measurement results,and R^(2)is always more significant than 0.95,the total average measurement error and relative error were only 6.16 mm and 4.38%,respectively,both are within the acceptable agronomy range.In general,this method has good universality for plant stem detection,and the stem phenotypic parameters can be obtained by means of non-contact test,which is of great significance to the mechanized cultivation of the forest and fruit industry.展开更多
针对菇房内杏鲍菇表型参数测量任务中,由于扫描设备视角受限,扫描的杏鲍菇点云出现残缺问题,基于AdaPoinTr(Adaptive geometry-aware point transformers)提出了改进的SwinPoinTr模型,实现了对残缺杏鲍菇点云的准确补全和杏鲍菇表型参...针对菇房内杏鲍菇表型参数测量任务中,由于扫描设备视角受限,扫描的杏鲍菇点云出现残缺问题,基于AdaPoinTr(Adaptive geometry-aware point transformers)提出了改进的SwinPoinTr模型,实现了对残缺杏鲍菇点云的准确补全和杏鲍菇表型参数的测量。该方法在使用提出的特征重塑模块的基础上,构建具有几何感知能力的层次化Transformer编码模块,提高了模型对输入点云的利用率和模型捕捉点云细节特征的能力。然后基于泊松重建方法完成了补全点云表面重建,并测量到杏鲍菇表型参数。实验结果表明,本文所提算法在残缺杏鲍菇点云补全任务中,模型倒角距离为1.316×10^(-4),地球移动距离为21.3282,F1分数为87.87%。在表型参数估测任务中,模型对杏鲍菇菌高、体积、表面积估测结果的决定系数分别为0.9582、0.9596、0.9605,均方根误差分别为4.4213 mm、10.8185 cm^(3)、7.5778 cm^(2)。结果证实了该研究方法可以有效地补全残缺的杏鲍菇点云,可以为菇房内杏鲍菇表型参数测量提供基础。展开更多
文摘Hepatocellular carcinoma presents with three distinct immune phenotypes,including immune-desert,immune-excluded,and immune-inflamed,indicating various treatment responses and prognostic outcomes.The clinical application of multi-omics parameters is still restricted by the expensive and less accessible assays,although they accurately reflect immune status.A comprehensive evaluation framework based on“easy-to-obtain”multi-model clinical parameters is urgently required,incorporating clinical features to establish baseline patient profiles and disease staging;routine blood tests assessing systemic metabolic and functional status;immune cell subsets quantifying subcluster dynamics;imaging features delineating tumor morphology,spatial configuration,and perilesional anatomical relationships;immunohistochemical markers positioning qualitative and quantitative detection of tumor antigens from the cellular and molecular level.This integrated phenomic approach aims to improve prognostic stratification and clinical decision-making in hepatocellular carcinoma management conveniently and practically.
文摘The internal flow fields within a three-dimensional inward-tunning combined inlet are extremely complex,especially during the engine mode transition,where the tunnel changes may impact the flow fields significantly.To develop an efficient flow field reconstruction model for this,we present an Improved Conditional Denoising Diffusion Generative Adversarial Network(ICDDGAN),which integrates Conditional Denoising Diffusion Probabilistic Models(CDDPMs)with Style GAN,and introduce a reconstruction discrimination mechanism and dynamic loss weight learning strategy.We establish the Mach number flow field dataset by numerical simulation at various backpressures for the mode transition process from turbine mode to ejector ramjet mode at Mach number 2.5.The proposed ICDDGAN model,given only sparse parameter information,can rapidly generate high-quality Mach number flow fields without a large number of samples for training.The results show that ICDDGAN is superior to CDDGAN in terms of training convergence and stability.Moreover,the interpolation and extrapolation test results during backpressure conditions show that ICDDGAN can accurately and quickly reconstruct Mach number fields at various tunnel slice shapes,with a Structural Similarity Index Measure(SSIM)of over 0.96 and a Mean-Square Error(MSE)of 0.035%to actual flow fields,reducing time costs by 7-8 orders of magnitude compared to Computational Fluid Dynamics(CFD)calculations.This can provide an efficient means for rapid computation of complex flow fields.
基金Project(41130742)supported by the Key Program of National Natural Science Foundation of ChinaProject(2014CB046904)supportedby the National Basic Research Program of China+1 种基金Project(2011CDA119)supported by Natural Science Foundation of Hubei Province,ChinaProject(40972178)supported by the General Program of National Natural Science Foundation of China
文摘The shear behavior of rock joints is important in solving practical problems of rock mechanics. Three group rock joints with different morphologies are made by cement mortar material and a series of CNL(constant normal loading) shear tests are performed. The influences of the applied normal stress and joint morphology to its shear strength are analyzed. According to the experimental results, the peak dilatancy angle of rock joint decreases with increasing normal stress, but increases with increasing roughness. The shear strength increases with the increasing normal stress and the roughness of rock joint. It is observed that the modes of failure of asperities are tensile, pure shear, or a combination of both. It is suggested that the three-dimensional roughness parameters and the tensile strength are the appropriate parameter for describing the shear strength criterion. A new peak shear criterion is proposed which can be used to predict peak shear strength of rock joints. All the used parameters can be easily obtained by performing tests.
文摘Objective To establish three-dimensional phenotyping system for congenital heart disease in mouse and to lay a foundation for the study of phenotype identification and mechanism of congenital heart disease.Methods Twelve SPF C57BL/6 J wild type pregnant mice(8-10 week-old)were randomly divided into control group(n=6)and experimental group(n=6).
基金funded by the National Natural Science Foundation of China(42071014).
文摘Gobi spans a large area of China,surpassing the combined expanse of mobile dunes and semi-fixed dunes.Its presence significantly influences the movement of sand and dust.However,the complex origins and diverse materials constituting the Gobi result in notable differences in saltation processes across various Gobi surfaces.It is challenging to describe these processes according to a uniform morphology.Therefore,it becomes imperative to articulate surface characteristics through parameters such as the three-dimensional(3D)size and shape of gravel.Collecting morphology information for Gobi gravels is essential for studying its genesis and sand saltation.To enhance the efficiency and information yield of gravel parameter measurements,this study conducted field experiments in the Gobi region across Dunhuang City,Guazhou County,and Yumen City(administrated by Jiuquan City),Gansu Province,China in March 2023.A research framework and methodology for measuring 3D parameters of gravel using point cloud were developed,alongside improved calculation formulas for 3D parameters including gravel grain size,volume,flatness,roundness,sphericity,and equivalent grain size.Leveraging multi-view geometry technology for 3D reconstruction allowed for establishing an optimal data acquisition scheme characterized by high point cloud reconstruction efficiency and clear quality.Additionally,the proposed methodology incorporated point cloud clustering,segmentation,and filtering techniques to isolate individual gravel point clouds.Advanced point cloud algorithms,including the Oriented Bounding Box(OBB),point cloud slicing method,and point cloud triangulation,were then deployed to calculate the 3D parameters of individual gravels.These systematic processes allow precise and detailed characterization of individual gravels.For gravel grain size and volume,the correlation coefficients between point cloud and manual measurements all exceeded 0.9000,confirming the feasibility of the proposed methodology for measuring 3D parameters of individual gravels.The proposed workflow yields accurate calculations of relevant parameters for Gobi gravels,providing essential data support for subsequent studies on Gobi environments.
基金This research was supported by grants from the National Natural Science Foundation of China(No.81501530)Hubei Province Health and Family Planning Scientific Research Project(No.WJ2019M130).
文摘Sometimes endometrial polyps,submucosal myomas,and endometrial cancer show similar findings under ultrasonography.The aim of this study was to assess the antidiastole value of blood flow parameters using three-dimensional(3D)power Doppler ultrasonography angiography(PDA)between endometrial cancer and uterine parenchyma lumps.The data of the blood flow indices in 3D-PDA including the vascularization index(VI),flow index(FI),and vascularization flow index(VFI)in 40 patients with endometrial cancer and 41 patients with uterine parenchyma lumps(endometrial polyps and submucosal myomas)were retrospectively analysed and compared utilizing Virtual Organ Computer-aided AnaLysis(VOCAL)software.The results showed that all the blood flow parameters(VI,FI,VFI)were significantly higher in women with endometrial cancer than in those with uterine parenchyma lumps(P<0.001).The area under the curve of ROC of VI,FI,and VFI was 0.98,0.84,and 0.97,respectively.Thus,the best predictor of endometrial carcinoma was VI with a sensitivity of 97.0% and a specificity of 91.0%.The optimal cutoff value of VI was 4.06%.Our data demonstrated that all of the blood flow signal parameters(including VI,FI,and VFI)in 3D power Doppler ultrasonography had significant antidiastole values between endometrial cancer and uterine parenchyma lumps to assist clinicians in properly diagnosing patients.
基金Projects(51474251,51874351)supported by the National Natural Science Foundation,China。
文摘It is important to calibrate micro-parameters for applying partied flow code(PFC)to study mechanical characteristics and failure mechanism of rock materials.Uniform design method is firstly adopted to determine the microscopic parameters of parallel-bonded particle model for three-dimensional discrete element particle flow code(PFC3D).Variation ranges of microscopic of the microscopic parameters are created by analyzing the effects of microscopic parameters on macroscopic parameters(elastic modulus E,Poisson ratio v,uniaxial compressive strengthσc,and ratio of crack initial stress to uniaxial compressive strengthσci/σc)in order to obtain the actual uniform design talbe.The calculation equations of the microscopic and macroscopic parameters of rock materials can be established by the actual uniform design table and the regression analysis and thus the PFC3D microscopic parameters can be quantitatively determined.The PFC3D simulated results of the intact and pre-cracked rock specimens under uniaxial and triaxial compressions(including the macroscopic mechanical parameters,stress−strain curves and failure process)are in good agreement with experimental results,which can prove the validity of the calculation equations of microscopic and macroscopic parameters.
基金funded by the Shandong Modern Agricultural Technology & Industry System,Chinathe Seed Production Technology and Development of Key Equipment and Demonstration(201203052) from Special Funds for Agro-scientific Research in the Public Interest,China+1 种基金the Maize Germplasm Innovation of Shandong Seed Industry Project,Chinathe Shandong Province Modern Agriculture Industrial Production Technology System,China (SDAIT-01-022-02)
文摘To explore the relation of maize grain texture and phenotypic traits with grain thin-layer drying rate,we observed the ultra-structure of maize grain,and tested three traits about the maize grain texture and four phenotypic traits.The vitreous part percentage was different（P〈0.05） among different maize inbred lines.There was a significant relationship between the drying rate with grain texture and phenotypic traits.Main factors that influenced the drying rate were different during different drying stages.New results observed that empirical constants（k and N） in drying equation were different for seed of the 30 inbred lines of maize.The k of simplified diffusion equation and N of page equation were significantly influenced by both grain texture and phenotypic traits.These results could be used as guideline parameters for drying maize seeds having different grain characteristics during different drying stages.
文摘This paper conducts a trade-off between efficiency and accuracy of three-dimensional(3 D)shape measurement based on the triangulation principle,and introduces a flying and precise 3 D shape measurement method based on multiple parallel line lasers.Firstly,we establish the measurement model of the multiple parallel line lasers system,and introduce the concept that multiple base planes can help to deduce the unified formula of the measurement system and are used in simplifying the process of the calibration.Then,the constraint of the line spatial frequency,which maximizes the measurement efficiency while ensuring accuracy,is determined according to the height distribution of the object.Secondly,the simulation analyzing the variation of the systemic resolution quantitatively under the circumstance of a set of specific parameters is performed,which provides a fundamental thesis for option of the four system parameters.Thirdly,for the application of the precision measurement in the industrial field,additional profiles are acquired to improve the lateral resolution by applying a motor to scan the 3 D surface.Finally,compared with the line laser,the experimental study shows that the present method of obtaining 41220 points per frame improves the measurement efficiency.Furthermore,the accuracy and the process of the calibration are advanced in comparison with the existing multiple-line laser and the structured light makes an accuracy better than 0.22 mm at a distance of 956.02 mm.
基金The study was supported by the National Natural Science Foundation of China(No.51975165).
文摘Three-dimensional sand printing(3DSP)is widely applied in sand mold fabrication.In this study,the effects of printing parameters including the resolution of printehead holes,activator content,layer thickness,and recoating speed on the tensile and bending strengths,gas evolution,and loss-on-ignition(LOI)of 3DSP samples were investigated by changing single parameter,and the dimension deviation was also measured.As the resolution increases,the tensile strength,bending strength,gas evolution,LOI,and deviations at X-and Y-axis directions decrease gradually while the deviation at Z-axis direction firstly increases and then deceases.The gas evolution and LOI drops by 13.02%and 8.13%respectively,but the strength only reduces by 2.2% when the resolution increases from 0.08 mm to 0.09 mm.The strengths of samples rise at first and then decline while the gas evolution and LOI rise gradually with the increasing activator content or recoating speed.The activator content is found to have little effect on the gas evolution as the activator increases from 0.14%to 0.34%,the gas evolution is increased by 7.3%which is far less than the LOI increment of 24.1%.As the layer thickness increases,the tensile and bending strengths firstly rise and then drop while gas evolution and LOI descend.Under the optimal printing parameters of 0.09 mm resolution,0.18%activator,-10.28 mm layer thickness and 160 mm·s^(-1) recoating speed,the tensile strengths for X-sample and Y-sample are 1.48 MPa and 1.37 MPa,the bending strengths are 1.84 MPa and 1.75 MPa,the gas evolution and LOI are-19.62 mL·g^(-1) and 1.92%,respectively.
基金supported by the National Natural Science Foundation of China under Grant[52077027]Liaoning Province Science and Technology Major Project[No.2020JH1/10100020].
文摘In this paper, the axial-flux permanent magnet driver is modeledand analyzed in a simple and novel way under three-dimensional cylindricalcoordinates. The inherent three-dimensional characteristics of the deviceare comprehensively considered, and the governing equations are solved bysimplifying the boundary conditions. The axial magnetization of the sectorshapedpermanent magnets is accurately described in an algebraic form bythe parameters, which makes the physical meaning more explicit than thepurely mathematical expression in general series forms. The parameters of theBessel function are determined simply and the magnetic field distribution ofpermanent magnets and the air-gap is solved. Furthermore, the field solutionsare completely analytical, which provides convenience and satisfactoryaccuracy for modeling a series of electromagnetic performance parameters,such as the axial electromagnetic force density, axial electromagnetic force,and electromagnetic torque. The correctness and accuracy of the analyticalmodels are fully verified by three-dimensional finite element simulations and a15 kW prototype and the results of calculations, simulations, and experimentsunder three methods are highly consistent. The influence of several designparameters on magnetic field distribution and performance is studied and discussed.The results indicate that the modeling method proposed in this papercan calculate the magnetic field distribution and performance accurately andrapidly, which affords an important reference for the design and optimizationof axial-flux permanent magnet drivers.
基金financially supported by Shandong Provincial Key Research and Development Program(Grant No.2022LZGCQY002,2021LZGC013,2023TZXD004).
文摘Accurate and rapid wheat morphology reconstruction and trait collection are essential for selecting varieties,scientific cultivation,and precise management.A single perspective is limited by environmental obstructions,hindering the collection of high-throughput phenotype data for wheat plants.Therefore,a rapid reconstruction method of multi-view threedimensional point cloud is proposed to realize the high-throughput and accurate identification of wheat phenotype.Firstly,taking wheat at the tillering stage as the experimental object,a multi-view acquisition system based on a RealSense sensor was constructed,and the point cloud data of wheat were obtained from 16 views.Secondly,a joint photometric and geometric objective was optimized,and space location was registered by colored Point Cloud Registration(colored)and Iterative Closest Point(ICP)algorithms.Furthermore,the Multiple View Stereo(MVS)algorithm was used to combine the depth image,RGB image,and spatial position obtained by coarse registration to enable the fine registration of multi-viewpoint clouds.Compared with the traditional Structure From Motion(SFM)-MVS algorithm,our proposed method is much faster,with an average reconstruction time of 33.82 s.Moreover,the wheat plant height,leaf length,leaf width,leaf area,and leaf angle of wheat were calculated based on the three-dimensional point cloud of the wheat plant.The experimental results showed that the determination coefficients of the method are 0.996,0.958,0.956,0.984,and 0.849,respectively.Finally,phenotypic information such as compact degree,convex hull volume,and average leaf area of different wheat varieties was analyzed and identified,proving that the method could capture the phenotypic differences between varieties and individuals.The proposed method provides a rapid approach to quantify wheat phenotypic traits,aiding breeding,scientific cultivation,and environmental management.
基金supported by the National Key Research and Development Program of China Sub-project(Grant No.2018YFD0700302-02)the National Natural Science Foundation of China(Grant No.61805073,51975186).
文摘In order to obtain the phenotypic parameters of apple quickly and accurately,which were commonly used as the basis of fruit sorting,a fast estimation method of apple phenotypic parameters based on three-dimensional(3D)reconstruction was proposed in this study.In this study,a three-dimensional model was constructed to estimate the phenotypic parameters of apple,such as volume,height,diameter,and fruit shape index.Firstly,an image acquisition system was built to capture sequence images of fruit with a binocular stereo vision system,and the images were extracted and matched using the Accelerated-KAZE algorithm to create the point cloud data.Secondly,the point cloud data were matched with the algorithm of Iterative Closest Point to establish a whole model of apple,and the surface reconstruction model of fruit was obtained by constructing irregular triangulation network.Finally,the apple phenotypic parameters were calculated by means of segmentation,surface complement and integral of the fruit model.Total of 200 apples were used as samples in the experiment.By this method,the phenotypic parameters of the apples were estimated based on their 3D reconstruction model,and the linear regression analysis was carried out between the estimated values and the real values.The results showed that R2 of the linear regression fitting of each parameter was higher than 0.90.Among them,the fitting of volume was the best with R2 of 0.97.In addition,the average errors of apple volume,height,fruit shape index,maximum diameter D and minimum diameter d were 8.73 cm3,1.43 mm,1.28%,0.90 mm,and 1.23 mm,respectively.According to the Chinese national standard of“fresh Apple”,the average error of the estimated result is within the range of allowable error.It indicates that the method of apple phenotypic parameter estimation based on 3D reconstruction has a high accuracy and practicability,and it can be used as the support for fruit sorting.
基金This work was financially supported by the Laboratory of Lingnan Modern Agriculture Project(Grant No.NT2021009)the National Key Research and Development Program of China(Grant No.2020YFD1000104)+2 种基金the China Agriculture Research System of MOF and MARA(Grant No.CARS-31-10)the Key-Areas Research and Development Program of Guangdong Province,China(Grant No.2019B020223002)the Department of Education Special Program of Guangdong Province,China(Grant No.2020KZDZX1036).
文摘The measurement of banana pseudo-stem phenotypic parameters is a critical way to evaluate the growth status of bananas,and it can provide essential data support for mechanized cultivation operations such as fertilization and pesticide application.Existing studies mainly measure the diameter of banana pseudo-stem as its phenotypic parameter.The banana pseudo-stem cross section was closer to an ellipse other than a standard circle,so the diameter parameter cannot adequately represent the phenotypic characteristics of the banana plant.In this study,an automatic measuring device for banana pseudo-stem phenotypic parameters was developed.The device,which integrates three different types of sensors:a laser ranging sensor,a rotary encoder,and a digital camera,were used to obtain the point cloud and image data of banana pseudo-stem.A K-means point clouds clustering algorithm based on Euclidean distance was proposed.The point cloud of banana pseudo-stem was identified and extracted.A three-dimensional reconstruction algorithm based on the ellipse model was also proposed.The three-dimensional contour of the pseudo-stem was calculated to obtain three types of phenotypic parameters:the long axis length,the short axis length,and the perimeter.Further,a synchronous trigger image acquisition mechanism was used to take pictures of pseudo-stems during measurement.It can be utilized for manual assessment of the growth status of the banana.Field experimental results showed that the three banana phenotypic parameters had a high correlation with the manual measurement results,and R^(2)is always more significant than 0.95,the total average measurement error and relative error were only 6.16 mm and 4.38%,respectively,both are within the acceptable agronomy range.In general,this method has good universality for plant stem detection,and the stem phenotypic parameters can be obtained by means of non-contact test,which is of great significance to the mechanized cultivation of the forest and fruit industry.
