A geometric-based method for recognizing overlapping polygonal-shaped and semi-transparent particles in gray tone images

International audienceA geometric-based method is proposed to recognize the overlapping particles of different polygonal shapes such as rectangular, regular and/or irregular prismatic particles in a gray tone image. The first step consists in extracting the salient corners, identified by their locations and orientations, of the overlapping particles. Although there are certain difficulties like the perspective geometric projection, out of focus, transparency and superposition of the studied particles. Then, a new clustering technique is applied to detect the shape by grouping its correspondent salient corners according to the geometric properties of each shape. A simulation process is carried out for evaluating the performance of the proposed method. Then, it is particularly applied on a real application of batch cooling crystallization of the ammonium oxalate in pure water. The experimental results show that the method is efficient to recognize the overlapping particles of different shapes and sizes

A Multiscale Investigation of Habitat Use and Within-river Distribution of Sympatric Sand Darter Species

The western sand darter Ammocrypta clara, and eastern sand darter Ammocrypta pellucida are sand-dwelling fishes of conservation concern. Past research has emphasized the importance of studying individual populations of conservation concern, while recent research has revealed the importance of incorporating landscape scale processes that structure habitat mosaics and local populations. We examined habitat use and distributions of western and eastern sand darters in the lower Elk River of West Virginia. At the sandbar habitat use scale, western sand darters were detected in sandbars with greater area, higher proportions of coarse grain sand and faster bottom current velocity, while the eastern sand darter used a wider range of sandbar habitats. The landscape scale analysis revealed that contributing drainage area was an important predictor for both species, while sinuosity, which presumably represents valley type also contributed to the western sand darter’s habitat suitability. Sandbar quality (area, grain size, and velocity) and fluvial geomorphic variables (drainage area and valley type) are likely key driving factors structuring sand darter distributions in the Elk River. This multiscale study of within-river species distribution and habitat use is unique, given that only a few sympatric populations are known of western and eastern sand darters

Description of the adult male \u3cem\u3eScorpiops tongtongi\u3c/em\u3e Tang, 2022, with further comments on the genus \u3cem\u3eScorpiops\u3c/em\u3e Peters, 1861 in China (Scorpiones: Scorpiopidae)

Adult male Scorpiops tongtongi Tang, 2022 is described based on recently collected specimens, which revealed a strong sexual dimorphism in the pedipalp finger lobe of this species (present in males, absent in females), lending more support to the separation from its geographic neighbors, S. jendeki Kovařík, 1994, S. shidian (Qi et al., 2005), S. zhangshuyuani Ythier, 2019, and S. beccaloniae (Kovařík, 2005). The morphological studies of Chinese Scorpiops are further discussed. A refined mensurational method of Scorpiops pedipalp chela is proposed. Morphological comparisons of both quantitative and qualitative characters for all Scorpiops from Yunnan are provided, along with a dichotomous key to those species

Low to medium level image processing for a mobile robot

The use of visual perception in autonomous mobile systems was approached with caution by mobile robot developers because of the high computational cost and huge memory requirements of most image processing operations. When used, the image processing is implemented on multiprocessors or complex and expensive systems, thereby requiring the robot to be wired or radio controlled from the computer system base

Controlling Factors on Bedrock River Sinuosity in the Eastern Tibetan Plateau

Average sinuosity of bedrock rivers across the eastern Tibetan Plateau (including the Yangtze, Mekong, Salween, Irrawaddy, and Tsang Po) ranges from 1.20-1.41. From 25°-30°N, sinuosity marginally increases east to west; over the entire distance of each river, sinuosity increases north to south. Increases in sinuosity parallel a regional tectonic gradient in an area with a marginal climate gradient. Several past studies correlate sinuous bedrock rivers in mountainous regions with gradients in climate, arguing that landslides are the main mechanism by which bedrock rivers increase sinuosity. Other studies find correlations between tectonics and increasing landslide frequency. To investigate the role of these and other factors in increasing bedrock river sinuosity, I tested correlations between river sinuosity and bedrock, landslides, climate, and erosion rates. I found no linear correlation between sinuosity and bedrock type, landslides, climate, or erosion rates. These results indicate that none of the proposed correlating factors- are related to increasing sinuosity in this area, and that testing for other tectonic and geomorphic proxies including slope and mean local relief could provide insight

Controlling Factors on Bedrock River Sinuosity in the Eastern Tibetan Plateau

Average sinuosity of bedrock rivers across the eastern Tibetan Plateau (including the Yangtze, Mekong, Salween, Irrawaddy, and Tsang Po) ranges from 1.20-1.41. From 25°-30°N, sinuosity marginally increases east to west; over the entire distance of each river, sinuosity increases north to south. Increases in sinuosity parallel a regional tectonic gradient in an area with a marginal climate gradient. Several past studies correlate sinuous bedrock rivers in mountainous regions with gradients in climate, arguing that landslides are the main mechanism by which bedrock rivers increase sinuosity. Other studies find correlations between tectonics and increasing landslide frequency. To investigate the role of these and other factors in increasing bedrock river sinuosity, I tested correlations between river sinuosity and bedrock, landslides, climate, and erosion rates. I found no linear correlation between sinuosity and bedrock type, landslides, climate, or erosion rates. These results indicate that none of the proposed correlating factors- are related to increasing sinuosity in this area, and that testing for other tectonic and geomorphic proxies including slope and mean local relief could provide insight