1,081 research outputs found
Fast Hybrid Cascade for Voxel-based 3D Object Classification
Voxel-based 3D object classification has been frequently studied in recent
years. The previous methods often directly convert the classic 2D convolution
into a 3D form applied to an object with binary voxel representation. In this
paper, we investigate the reason why binary voxel representation is not very
suitable for 3D convolution and how to simultaneously improve the performance
both in accuracy and speed. We show that by giving each voxel a signed distance
value, the accuracy will gain about 30% promotion compared with binary voxel
representation using a two-layer fully connected network. We then propose a
fast fully connected and convolution hybrid cascade network for voxel-based 3D
object classification. This threestage cascade network can divide 3D models
into three categories: easy, moderate and hard. Consequently, the mean
inference time (0.3ms) can speedup about 5x and 2x compared with the
state-of-the-art point cloud and voxel based methods respectively, while
achieving the highest accuracy in the latter category of methods (92%).
Experiments with ModelNet andMNIST verify the performance of the proposed
hybrid cascade network
Workspace Analysis of a Novel Parallel Robot Named 3-R2H2S with Three Freedoms
Abstract: In order to meet the sorting and packing needs of the drug and food industries, a novel parallel robot mechanism named 3-R2H2S is proposed in this study, the kinematics equation of the robot was deduced and the inverse kinematics was calculated. The workspace model of the robot is analyzed by the boundary search method through the MATLAB and ADAMS kinematics software. The analysis results show that the robot has a large effective workspace with smooth boundary and can be widely applied in the field of industrial robots, the kinematics of micro robots and 3D coordinate measurements and the workspace of the robot can meet the needs of drug and food automation production line
The Mechanism of Intragranular Acicular Ferrite Nucleation Induced by Mg-Al-O Inclusions
The features of inclusion and microstructure for carbon structural steel containing Mg-Al-O inclusions were studied through the scanning electron microscope (SEM) and Energy Dispersive Spectrometer (EDS). It can be seen that, in Mg-Al-O inclusions, the elements of Mn, Si, and S coexist, and their central mole ratio of Mg/Al varies in a wide range. This value for most inclusions is larger than 0.5, which suggests the formation of solid solution between MgAl2O4 and MgO. After etching, the typical microstructure of intragranular acicular ferrites is observed, which is due to the nucleation effect induced by Mg-Al-O inclusions. From the SEM-EDS mapping images, it is found that the element of sulfur accumulates on the periphery of nucleation inclusion. Moreover, line EDS analysis hints that Mn-depletion zone (MDZ) exists in steel matrix, which is adjacent to the complex inclusion. Combined with the theoretical analysis, this phenomenon can be explained by the absorption of Mn due to the magnesium vacancy in MgAl2O4, and this MDZ promotes the nucleation of intragranular acicular ferrite. Through statistical analysis of SEM images for microstructure, the probabilistic nature of inducing nucleation effect is revealed. These results may be helpful to clarify the nature of oxide metallurgy
Scale-invariance of human EEG signals in sleep
We investigate the dynamical properties of electroencephalogram (EEG) signals
of human in sleep. By using a modified random walk method, We demonstrate that
the scale-invariance is embedded in EEG signals after a detrending procedure.
Further more, we study the dynamical evolution of probability density function
(PDF) of the detrended EEG signals by nonextensive statistical modeling. It
displays scale-independent property, which is markedly different from the
turbulent-like scale-dependent PDF evolution.Comment: 4 pages and 6 figure
The effects of metabolic indicators and immune biomarkers on pregnancy outcomes in women with recurrent spontaneous abortion: a retrospective study
BackgroundThe etiology of recurrent spontaneous abortion (RSA) remains elusive despite specific investigations affirming the association between RSA and thyroid autoimmunity (TAI). This study explores the immunological and metabolic profiles of RSA patients exhibiting positive thyroid antibodies and their connection with the rates of first-trimester miscarriage and live births. The aim is to provide further guidance for clinical interventions.MethodsA retrospective analysis included 478 women with RSA. Thyroid profile, thyroid peroxidase antibodies, and anti-thyroglobulin antibodies were measured in all participants. The clinical characteristics and pregnancy outcomes of RSA women were compared between thyroid autoimmunity (TAI)-positive and TAI-negative patients. Significant factors associated with adverse pregnancy outcomes and risk prediction models were explored in TAI-positive patients. Correlation analysis was used to identify specific metabolic or immune biomarkers associated with thyroid autoantibodies.ResultsThe prevalence of TAI was 18.6%. Compared with women without TAI, the thyroid-stimulating hormone (TSH) concentration of TAI-positive RSA was significantly higher (2.80 ± 2.98 vs 1.89 ± 1.17, p=0.006). After 28 weeks, the live birth rate of the TAI-positive group was lower than that of the TAI-negative group, with statistical significance (p<0.05). The immune biomarkers that differed between RSA women with live births and those with first-trimester miscarriages were complement C4 and interleukin-6, respectively, in TAI-negative and TAI-positive women. Then, a risk prediction model for first-trimester miscarriage was constructed for TAI-positive women with an AUC of 0.81. Finally, some factors related to thyroid peroxidase antibody (TPO-Ab) levels were explored, and it was found that TPO-Ab levels were positively correlated with free thyroxine and negatively correlated with 25 hydroxyvitamin D, interleukin-4, and fasting blood glucose in RSA patients.ConclusionTAI-positive RSA patients have higher first-trimester miscarriage rates and a lower live birth rate, which may be related to metabolic immune shifts in TAI-positive RSA patients
Scaling behaviour and memory in heart rate of healthy human
We investigate a set of complex heart rate time series from healthy human in different behaviour states with the detrended fluctuation analysis and diffusion entropy (DE) method. It is proposed that the scaling properties are influenced by behaviour states. The memory detected by DE exhibits an approximately same pattern after a detrending procedure. Both of them demonstrate the long-range strong correlations in heart rate. These findings may be helpful to understand the underlying dynamical evolution process in the heart rate control system, as well as to model the cardiac dynamic process
Mercury–Organic Matter Interactions in Soils and Sediments: Angel or Devil?
Embargo until 02 January 2020Many studies have suggested that organic matter (OM) substantially reduces the bioavailability and risks of mercury (Hg) in soils and sediments; however, recent reports have supported that OM greatly accelerates Hg methylation and increases the risks of Hg exposure. This study aims to summarize the interactions between Hg and OM in soils and sediments and improve our understanding of the effects of OM on Hg methylation. The results show that OM characteristics, promotion of the activity of Hg-methylating microbial communities, and the microbial availability of Hg accounted for the acceleration of Hg methylation which increases the risk of Hg exposure. These three key aspects were driven by multiple factors, including the types and content of OM, Hg speciation, desorption and dissolution kinetics and environmental conditions.acceptedVersio
Poly[trisÂ(μ3-5-aminoÂisophthalato)diaquaÂdicerium(III)]
In the title complex, [Ce2(C8H5NO4)3(H2O)2]n, each Ce ion is in nine-coordinated environment. Eight O atoms from six ligands participate in coordination, in addition to one O atom from a water molÂecule. Both carboxylÂate groups from the ligands chelate the Ce atoms, forming two four-membered rings. The 5-aminoÂisophthalate ligands also bridge the Ce centers, forming a two-dimensional network, and O—H⋯O and N—H⋯O hydrogen bonds complete the structure
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