VommaNet: an End-to-End Network for Disparity Estimation from Reflective and Texture-less Light Field Images

The precise combination of image sensor and micro-lens array enables lenslet light field cameras to record both angular and spatial information of incoming light, therefore, one can calculate disparity and depth from light field images. In turn, 3D models of the recorded objects can be recovered, which is a great advantage over other imaging system. However, reflective and texture-less areas in light field images have complicated conditions, making it hard to correctly calculate disparity with existing algorithms. To tackle this problem, we introduce a novel end-to-end network VommaNet to retrieve multi-scale features from reflective and texture-less regions for accurate disparity estimation. Meanwhile, our network has achieved similar or better performance in other regions for both synthetic light field images and real-world data compared to the state-of-the-art algorithms. Currently, we achieve the best score for mean squared error (MSE) on HCI 4D Light Field Benchmark

CFAD: A Chinese Dataset for Fake Audio Detection

Fake audio detection is a growing concern and some relevant datasets have been designed for research. However, there is no standard public Chinese dataset under complex conditions.In this paper, we aim to fill in the gap and design a Chinese fake audio detection dataset (CFAD) for studying more generalized detection methods. Twelve mainstream speech-generation techniques are used to generate fake audio. To simulate the real-life scenarios, three noise datasets are selected for noise adding at five different signal-to-noise ratios, and six codecs are considered for audio transcoding (format conversion). CFAD dataset can be used not only for fake audio detection but also for detecting the algorithms of fake utterances for audio forensics. Baseline results are presented with analysis. The results that show fake audio detection methods with generalization remain challenging. The CFAD dataset is publicly available at: https://zenodo.org/record/8122764.Comment: FAD renamed as CFA

Habitat Elevation Shapes Microbial Community Composition and Alter the Metabolic Functions in Wild Sable (Martes zibellina) Guts

In recent decades, wild sable (Carnivora Mustelidae Martes zibellina) habitats, which are often natural forests, have been squeezed by anthropogenic disturbances such as clear-cutting, tilling and grazing. Sables tend to live in sloped areas with relatively harsh conditions. Here, we determine effects of environmental factors on wild sable gut microbial communities between high and low altitude habitats using Illumina Miseq sequencing of bacterial 16S rRNA genes. Our results showed that despite wild sable gut microbial community diversity being resilient to many environmental factors, community composition was sensitive to altitude. Wild sable gut microbial communities were dominated by Firmicutes (relative abundance 38.23%), followed by Actinobacteria (30.29%), and Proteobacteria (28.15%). Altitude was negatively correlated with the abundance of Firmicutes, suggesting sable likely consume more vegetarian food in lower habitats where plant diversity, temperature and vegetation coverage were greater. In addition, our functional genes prediction and qPCR results demonstrated that energy/fat processing microorganisms and functional genes are enriched with increasing altitude, which likely enhanced metabolic functions and supported wild sables to survive in elevated habitats. Overall, our results improve the knowledge of the ecological impact of habitat change, providing insights into wild animal protection at the mountain area with hash climate conditions

Habitat Elevation Shapes Microbial Community Composition and Alter the Metabolic Functions in Wild Sable (Martes zibellina) Guts

In recent decades, wild sable (Carnivora Mustelidae Martes zibellina) habitats, which are often natural forests, have been squeezed by anthropogenic disturbances such as clear-cutting, tilling and grazing. Sables tend to live in sloped areas with relatively harsh conditions. Here, we determine effects of environmental factors on wild sable gut microbial communities between high and low altitude habitats using Illumina Miseq sequencing of bacterial 16S rRNA genes. Our results showed that despite wild sable gut microbial community diversity being resilient to many environmental factors, community composition was sensitive to altitude. Wild sable gut microbial communities were dominated by Firmicutes (relative abundance 38.23%), followed by Actinobacteria (30.29%), and Proteobacteria (28.15%). Altitude was negatively correlated with the abundance of Firmicutes, suggesting sable likely consume more vegetarian food in lower habitats where plant diversity, temperature and vegetation coverage were greater. In addition, our functional genes prediction and qPCR results demonstrated that energy/fat processing microorganisms and functional genes are enriched with increasing altitude, which likely enhanced metabolic functions and supported wild sables to survive in elevated habitats. Overall, our results improve the knowledge of the ecological impact of habitat change, providing insights into wild animal protection at the mountain area with hash climate conditions

An Investigation of the Influences of SWOT Sampling and Errors on Ocean Eddy Observation

The mission of Surface Water and Ocean Topography (SWOT) is scheduled to be launched in 2022, and global ocean eddies with radius scales of larger than 10 km are expected to be observed from space. However, there are still open questions about the capability of SWOT to detect ocean eddies. Based on ocean model data and SWOT orbit, this study simulates along-track observation of SWOT. Two eddy datasets are derived from simulated observation data via mapping and eddy identification procedures, one of which includes SWOT errors and the other does not. The third eddy dataset is generated from the original model data. Through comparing these three eddy datasets, it is found that 34% (40%) eddies are lost due to insufficient temporal sampling and errors in the Kuroshio Extension (South China Sea) region, and numerous artifact eddies are generated. To further explain the influence of SWOT errors on smaller-scale eddies, two eddies (a cyclonic eddy and an anticyclonic eddy) with the radius of about 10 km are repeatedly observed 100 times using the SWOT-simulator. The cyclonic eddy with larger amplitude has been detected 84 times, while the anticyclonic eddy is visible 76 times. Therefore, the influence of the SWOT sampling and errors on ocean eddy observation is revealed by the results of these observing system simulation experiments (OSSEs)

A novel light field imaging based 3D geometry measurement technique for turbomachinery blades

This paper presents a novel snapshot three-dimensional (3D) imaging technique for fast turbomachinery blade geometrical measurements. The proposed measurement system employs a microlens array based light-field camera to capture 3D blade geometry into one light-field image, from which 100 new perspective images can be generated and the blade 3D point cloud can be recovered through sophisticated light-field rendering algorithms. The measurement accuracy is determined to be approximately 35 μm by measuring a series of standard gauge blocks. Performance of the proposed technique is compared against a coordinate-measuring machine (CMM) and laser scanner by measuring a turbine blade. It reveals that the single light-field camera 3D measurement system can produce 820 000 data point in 30 s with an average measurement accuracy of 61.00 μm, which is considerably more efficient than the current CMM and laser scanning techniques.Financial support provided by National Natural Science Foundation of China (NSFC, 11772197) and VOMMA Optec Co Ltd are gratefully acknowledged

Bio-Inspired Aramid Fibers@silica Binary Synergistic Aerogels with High Thermal Insulation and Fire-Retardant Performance

Flame-retardant, thermal insulation, mechanically robust, and comprehensive protection against extreme environmental threats aerogels are highly desirable for protective equipment. Herein, inspired by the core (organic)-shell (inorganic) structure of lobster antenna, fire-retardant and mechanically robust aramid fibers@silica nanocomposite aerogels with core-shell structures are fabricated via the sol-gel-film transformation and chemical vapor deposition process. The thickness of silica coating can be well-defined and controlled by the CVD time. Aramid fibers@silica nanocomposite aerogels show high heat resistance (530 °C), low thermal conductivity of 0.030 W·m−1·K−1, high tensile strength of 7.5 MPa and good flexibility. More importantly, aramid fibers@silica aerogels have high flame retardancy with limiting oxygen index 36.5. In addition, this material fabricated by the simple preparation process is believed to have potential application value in the field of aerospace or high-temperature thermal protection

Research Progress and Prospects of Agricultural Aero-Bionic Technology in China

Accelerating the development of agricultural aviation technology is the need of China’s modern agricultural construction. With the rise of emerging industries such as artificial intelligence, biotechnology, autonomous navigation, and the Internet of Things, agricultural aviation is further developing toward the direction of intelligence to meet the requirements of efficient and sophisticated agricultural aviation operations. Bionics is a multi-discipline and comprehensive border subject. It is produced by the mutual penetration and integration of life science and engineering science. Bionic technology has received more and more attention in recent years, and breakthroughs have been made in the fields of biomedicine and health, military, brain science and brain-like navigation, and advanced manufacturing. This study summarized the research progress of biomimetic technology in the field of agricultural aviation from three aspects of biological perception, biological behavior, and biological intelligence. On this basis, problems of related research and application of agricultural aircraft in real-time obstacle avoidance, path planning, and intelligent navigation were analyzed. Combined with the practice of the rapid development of agricultural aircraft, research and application of bionic technology suitable for agricultural aircraft were then proposed. Finally, prospects of agricultural aero-bionic technology were also discussed from multiple bionic target fusion, three-dimensional spatial information exploration, sensors, and animal brain system mechanism. This review provides a reference for the development of bionic technology in China’s agricultural aviation