Study on the Formation of Reactive Material Shaped Charge Jet by Trans-Scale Discretization Method

The formation process of reactive materials shaped charge is investigated by X-ray photographs and numerical simulation. In order to study the formation process, a trans-scale discretization method is proposed. A two-dimensional finite element model of shaped charge and reactive material liner is established and the jet formation process, granule size difference induced particle dispersion and granule distribution induced jet particle distribution are analyzed based on Autodyn-2D platform and Euler solver. The result shows that, under shock loading of shaped charge, the Al particle content decreases from the end to the tip of the jet, and increases as the particle size decreases. Besides, the quantity of Al particles at the bottom part of the liner has more prominent influence on the jet head density than that in the other parts, and the Al particle content in the high-speed section of jet shows inversely proportional relationship to the ratio of the particle quantity in the top area to that in the bottom area of liner.

A surface defect detection method via fusing multi-level features

Surface defect detection is very important to ensure product quality, but most of the surface defects of industrial products are characterized by low contrast, big size difference and category similarity, which brings challenges to the automatic detection of defects. To solve these problems, we propose a defect detection method based on convolutional neural network. In this method, a backbone network with semantic supervision is applied to extract the features of different levels. While a multi-level feature fusion module is proposed to fuse adjacent feature maps into high-resolution feature maps successively, which significantly improves the prediction accuracy of the network. Finally, an Encoding module is used to obtain the global context information of the high-resolution feature map, which further improves the pixel classification accuracy. Experiments show that the proposed method is superior to other methods in NEU_SEG (mIoU of 85.27) and MT (mIoU of 77.82) datasets, and has the potential of real-time detection.

Bill Variation of Captive and Wild Chukar Partridge Populations: Shape or Size

Traditionally, morphological characters are widely used to distinguish between interspecies and intraspecies. In addition to the size of morphological characters, shape has also been used as an indicator in the last decades. We evaluated the geometric morphometry and morphometric of the bill of Chukar Partridge, Alectoris chukar from captive and wild populations to determine the bill variation and population relationships. Although there was a size difference between the sexes, no shape difference was found. However, captive populations differed from wild populations in both size and shape. Although there was no difference in shape among wild populations, some differences were found in size. Moreover, bill sizes of captive populations were statistically longer than western, centre, and eastern wild populations. It was also shown that the western populations had the most significant variation among the wild populations. The results revealed that using the size and shape together was more effective in comparing populations.

Shape Approximation and Size Difference of the Upper Part of the Talus: Implication for Implant Design of the Talar Component for Total Ankle Replacement

The implant design of the talar component for total ankle replacement (TAR) should match the surface morphology of the talus so that the replaced ankle can restore the natural motion of the tibiotalar joint and may reduce postoperative complications. The purpose of this study was to introduce a new 3D fitting method (the two-sphere fitting method of the talar trochlea with three fitting resection planes) to approximate the shape of the upper part of the talus for the Chinese population. 90 models of the tali from CT images of healthy volunteers were used in this study. Geometrical fitting and morphological measurements were performed for the surface morphology of the upper part of the talus. The accuracy of the two-sphere fitting method of the talar trochlea was assessed by a comparison of previously reported data. Parameters of the fitting geometries with different sizes were recorded and compared. Results showed that compared with previously reported one-sphere, cylinder, and bitruncated cone fitting methods, the two-sphere fitting method presented the smallest maximum distance difference, indicating that talar trochlea can be approximated well as two spheres. The radius of the medial fitting sphere R M was 20.69 ± 2.19 mm which was significantly smaller than the radius of the lateral fitting sphere R L of 21.32 ± 1.88 mm. After grouping all data by the average radius of fitting spheres, the result showed that different sizes of the upper part of the talus presented significantly different parameters except the orientation of the lateral cutting plane, indicating that the orientation of the lateral cutting plane may keep consistent for all upper part of the talus and have no relationship with the size. The linear regression analyses demonstrated a weak correlation ( R 2 < 0.5 ) between the majority of parameters and the average radius of the fitting spheres. Therefore, different sizes of the upper part of the talus presented unique morphological features, and the design of different sizes of talar components for TAR should consider the size-specific characteristics of the talus. The parameters measured in this study provided a further understanding of the talus and can guide the design of different sizes of the talar components of the TAR implant.

Food habits of two species of tube-nosed bats, Murina hilgendorfi and Murina ussuriensis, in Hayakawa, central Japan

Knowledge of food habits is essential for understanding the life history of a species; however, such information about the enigmatic Murina genus of bats is little known. In this study, we examined the food habits of Murina hilgendorfi and Murina ussuriensis over four years in Hayakawa, central Japan, using traditional morphological fecal analysis. Fragments of arthropods of six orders (five identified families), and of five orders (five identified families), were found in the feces of M. hilgendorfi and M. ussuriensis, respectively. Both species consumed wingless arthropods (caterpillars and spiders), insects that rarely fly (ground beetles and bush crickets), or diurnal insects (dragonflies and hoverflies; i.e., that are resting at night) during the night, which is a clear indication of gleaning behavior in these bats. In spring, the large-bodied M. hilgendorfi more frequently consumed hard-bodied insects such as beetles and bush crickets, whereas the small-bodied M. ussuriensis more frequently consumed soft-bodied insects such as caterpillars, moths, spiders, and dipterans, suggesting that the body size difference influences their food habits, which may have contributed to food resource partitioning between these closely related bats. For M. hilgendorfi, beetles were the main prey in spring and autumn, while caterpillars and grasshoppers were more frequently consumed in spring and autumn, respectively, suggesting that they may have changed prey items according to seasonal fluctuations in food availability. To our knowledge, this study provides the first record of differences in the food habits of these two species.

Size-structured mating niche differentiation in the male-polyphenic mite Rhizoglyphus robini

Condition-dependent expression of alternative male morphs evolves when males of different sizes experience different mating niches, requiring different morphologies. Such mating niche differentiation can be due to competitive asymmetry between large and small males in contests over mating opportunities. Here, we tested the hypothesis that aggressive interactions among males cause size-structured mating niches in an acarid mite with condition-dependent male polyphenism: the bulb mite Rhizoglyphus robini. In this species, large males mature as armed fighters with enlarged legs, and small males as scramblers without modified legs. We staged experimental dyadic contests over a mating opportunity between either a pair of fighter males, or a fighter and a scrambler male. We predicted that the larger male would have a higher likelihood of mating first in contests among fighters, that the fighter male would have a higher likelihood of mating first in fighter-scrambler contests, that fighters would have a higher likelihood of interrupting ongoing copulations if they are larger than their mating rival, and that copulations in the presence of a fighter rival therefore last shorter than copulations with a scrambler rival present. We found that in contests among fighters, the larger male had a higher probability of mating first. In contests among a fighter and scrambler, the fighter male was more likely to mate first regardless of the body size difference between the contestants. Ongoing copulations were only rarely interrupted by the rival male (always by a fighter), and the probability of interruption did not depend on the body size difference between the mating male and its rival. Copulations lasted shorter in the presence of a rival fighter, but this effect was not attributable to interruption of copulations. We conclude that the fighting niche is particularly accessible for large males, as larger males have a higher probability of winning pre-copulatory contests. Such mating niche differentiation likely contributes to evolutionary maintenance of condition-dependent male polyphenism, where small males are forced to adopt an alternative mating tactic and hence develop a dedicated morphology.

X-Ray CT Investigation on Fractal Characteristics of Fine-Grained Tailing Sand in Fujian’s Makeng: Insight into the Mesoscopic Seepage Failure

This work is aimed at revealing the mesophysical process and mechanical behaviors of fine-grained tailing sand during seepage failure. The macroscopic seepage tests combined with posttest X-ray computed tomography (CT) were employed to study the fractal characteristics of mesostructure. Results show that before and after the seepage failure of fine-grained tailing sand, fractal of pore distribution ( D pd ) and fractal dimension of pore size ( D ps ) show a relatively obvious positive correlation with porosity. Tailing particles migrate along the seepage direction during the seepage process, resulting in the gradual decrease of D pd and pore distribution area. The D ps reflects the variation characteristics of pore number distribution with different pore sizes. The increase in D ps leads to a decrease in the uniformity of pore size and an increase in the size difference between pores. The mass fractal dimension ( D m ) of fine-grained tailing sand samples ranges from 1.6472 to 1.8256. With the increase of D m , the coefficient of uniformity ( C u ) of tailing sand tends to increase. The D m method can discern the seepage failure type of fine-grained tailing sand, and it is more accurate than the traditional method. This study provides a reference for the prevention and control of the seepage failure of tailing dam.

Oral Squamous Cells and Age Estimation in Exfoliative Cytology with Hematoxylin and Eosin Stain– A Quantitative Study

Introduction: Exfoliative cytology in age estimation is a simple, painless, less invasive collection of exfoliative cells from epithelial layers, used as a diagnostic aid for age estimation. The oral cavity is an ideal site for exfoliative epithelial cells with a physiological turnover of cells, turnover decreases as the age increases show age variation with cellular morphological changes. Age estimation is one of the important factors to identify an individual and also helps to know the chronological age of a person. Aim: To analyze and estimate the age from buccal smear and comparing the average cellular size under Image morphometric analysis. Materials and Methods: Buccal mucosal smears are taken using a wooden spatula in gentle motion of scraping and smeared on a clean glass slide and fixed in 95% ethanol immediately after smearing a minimum of around 15 minutes and stained with Haematoxylin and eosin stain. After staining, the cells were observed by microscope and measured by a paint tool. Pearson correlation analysis was done using SPSS software. Results: The cell and nuclear size difference values observed using a Pearson correlation coefficient were statistically significant with p value<0.05 revealing that there is shrinkage in cells with increase in age. Conclusion: Exfoliative cytology is a successful and vastly growing technology that is used for the detection of premalignant lesions.

Reliable Template Matching for Image Detection in Vision Sensor Systems

Template matching is a simple image detection algorithm that can easily detect different types of objects just by changing the template without tedious training procedures. Despite these advantages, template matching is not currently widely used. This is because traditional template matching is not very reliable for images that differ from the template. The reliability of template matching can be improved by using additional information (depths for the template) available from the vision sensor system. Methods of obtaining the depth of a template using stereo vision or a few (two or more) template images or a short template video via mono vision are well known in the vision literature and have been commercialized. In this strategy, this paper proposes a template matching vision sensor system that can easily detect various types of objects without prior training. To this end, by using the additional information provided by the vision sensor system, we study a method to increase the reliability of template matching, even when there is a difference in the 3D direction and size between the template and the image. Template images obtained through the vision sensor provide a depth template. Using this depth template, it is possible to predict the change of the image according to the difference in the 3D direction and the size of the object. Using the predicted changes in these images, the template is calibrated close to the given image, and then template matching is performed. For ease of use, the algorithm is proposed as a closed form solution that avoids tedious recursion or training processes. For wider application and more accurate results, the proposed method considers the 3D direction and size difference in the perspective projection model and the general 3D rotation model.

Diabetic Retinopathy Diagnosis Based on RA-EfficientNet

The early detection and grade diagnosis of diabetic retinopathy (DR) are very important for the avoidance of blindness, and using deep learning methods to automatically diagnose DR has attracted great attention. However, the small amount of DR data limits its application. To automatically learn the disease’s features and detect DR more accurately, we constructed a DR grade diagnostic model. To realize the model, the authors performed the following steps: firstly, we preprocess the DR images to solve the existing problems in an APTOS 2019 dataset, such as size difference, information redundancy and the data imbalance. Secondly, to extract more valid image features, a new network named RA-EfficientNet is proposed, in which a residual attention (RA) block is added to EfficientNet to extract more features and to solve the problem of small differences between lesions. EfficientNet has been previously trained on the ImageNet dataset, based on transfer learning technology, to overcome the small sample size problem of DR. Lastly, based on the extracted features, two classifiers are designed, one is a 2-grade classifier and the other a 5-grade classifier. The 2-grade classifier can diagnose DR, and the 5-grade classifier provides 5 grades of diagnosis for DR, as follows: 0 for No DR, 1 for mild DR, 2 for moderate, 3 for severe and 4 for proliferative DR. Experiments show that our proposed RA-EfficientNet can achieve better performance, with an accuracy value of 98.36% and a kappa score of 96.72% in a 2-grade classification and an accuracy value of 93.55% and a kappa score of 91.93% in a 5-grade classification. The results indicate that the proposed model effectively improves DR detection efficiency and resolves the existing limitation of manual feature extraction.