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Drogue detection for autonomous aerial refueling based on convolutional neural networks

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Chinese Journal of Aeronautics 2017年第1期30卷 380-390页

作者： wang xufeng Dong Xinmin Kong Xingwei Li Jianmin Zhang Bo School of Aeronautics and Astronautics Engineering Air Force Engineering University State Key Laboratory of Intelligent Technology and Systems Tsinghua National Laboratory for Information Science and Technology Department of Computer Science and Technology Tsinghua University

Drogue detection is a fundamental issue during the close docking phase of autonomous aerial refueling（AAR）. To cope with this issue, a novel and effective method based on deep learning with convolutional neural networks（CNNs） is proposed. In order to ensure its robustness and wide application, a deep learning dataset of images was prepared by utilizing real data of ‘‘Probe and Drogue＂ aerial refueling, which contains diverse drogues in various environmental conditions without artificial features placed on the drogues. By employing deep learning ideas and graphics processing units（GPUs）, a model for drogue detection using a Caffe deep learning framework with CNNs was designed to ensure the method＇s accuracy and real-time performance. Experiments were conducted to demonstrate the effectiveness of the proposed method, and results based on real AAR data compare its performance to other methods, validating the accuracy, speed, and robustness of its drogue detection ability.

关键词： Autonomous aerial refueling Computer vision Convolutional neural net-works Deep learning Drogue detection

Characteristics and stability of slope movement response to underground mining of shallow coal seams away from gullies

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International Journal of Mining Science and Technology 2012年第1期22卷 47-50页

作者： Zhang Dongsheng Fan Gangwei wang xufeng College of Geology and Exploration Engineering Xinjiang UniversityUrumchi 830046China School of Mines China University of Mining&TechnologyXuzhou 221116China State Key Laboratory of Coal Resource and Mine Safety China University of Mining&TechnologyXuzhou 221008China

Underground pressure is abnormal during mining of shallow coal seams under gullies. We studied gully slope movements, subject to underground mining, with physical simulation and theoretical analysis. The rules disclose that the slope rock slides horizontally in response to mining in the direction of gullies and rotates reversely with the appearance of a polygon block in mining away from gullies. We focused our attention on the case of mining away from a gully. We built a mechanical model in terms of a polygon block hinged structure and investigated the variation of horizontal thrust and shear force at the hinged point in relation to the rotation angle under different fragmentations. The Sliding-Rotation instability conditions of the polygon block hinged structure are presented based on the analyses of sliding instability and rotation instability. These results can serve as a theoretical guide for roof control during mining away from gullies in a coalfield defined by gullies.

关键词：地下开采不稳定浅煤层沟渠响应特性运动距离接缝

《望江南》:江南与茶人精神的文学书写——王旭烽访谈

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写作 2022年第3期42卷 5-14页

作者：王旭烽宋时磊浙江农林大学茶学与茶文化学院武汉大学文学院写作杂志社

2022年初,第五届茅盾文学奖得主王旭烽出版最新长篇小说《望江南》,作品中对杭州与杭州西湖、茶人命运在历史中的沉浮以及茶人丰富的精神世界等层面的文学书写值得特别关注。在访谈中,王旭烽表示书名、故事人物名字对于构建小说世界至... 详细信息

2022年初,第五届茅盾文学奖得主王旭烽出版最新长篇小说《望江南》,作品中对杭州与杭州西湖、茶人命运在历史中的沉浮以及茶人丰富的精神世界等层面的文学书写值得特别关注。在访谈中,王旭烽表示书名、故事人物名字对于构建小说世界至关重要,是衡量作家创作能力的核心指标之一。这部小说之所以取名《望江南》,不仅是出典于苏轼诗词,更重要的是这个词语中包含了明知生活艰辛却要直面生活的勇气。“江南”不仅是故乡,更是一种审美化的存在方式。小说写茶不是知识罗列,而是用茶来构筑文化小说。茶人应该有分寸、不狂躁、不懦弱,这是一种承担苦难的和平态度,杭嘉和身上体现出了茶人的精神特质。王旭烽还对当前新一代茶人的成长有所期许,并希望通过文学创作和教育教学等多种方式推动茶文化的普及。

关键词：王旭烽《望江南》茶人三部曲茶人精神茶文化

Flexible tuning of multifocal holographic imaging based on electronically controlled metasurfaces

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Photonics Research 2024年第1期12卷 61-69页

作者： OWEN ZENG CHENXIA LI BO FANG ZHI HONG xufeng JING Institute of Optoelectronic Technology China Jiliang UniversityHangzhou 310018China Centre for THz Research China Jiliang UniversityHangzhou 310018China College of Metrology&Measurement Engineering China Jiliang UniversityHangzhou 310018China

Programmable hyper-coded holography has the advantage of being programmable as well as being flexibly *** coded metamaterials with excellent electromagnetic modulation capability and the ability to control the phase to modulate the spatial radiation field through external excitation in the form of switching can be used to realize low-cost digital *** design a 1-bit encoded programmable metasurface,which is electrically connected to control the PIN diode in the switching state and to switch the condition of each metasurface cell between“0”and“1.”Using the designed programmable metasurface,we can randomly encode the cell structure to realize single-focus focusing,multi-focusing,and simple holographic letter *** on the nonlinear holographic model,we employ the Gerchberg-Saxton improvement algorithm to modulate the energy distribution at the focus by adjusting the phase ***,we introduce the Fourier convolution principle to regulate the holographic imaging focus flexibly.

关键词： holographic letter excitation

Environmental suitability evaluation for human settlements in an arid inland river basin： A case study of the Shiyang River Basin

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Journal of Geographical Sciences 2013年第2期23卷 331-343页

作者： WEi Wei SHI Peiji ZHOU Junju FENG Haichun wang xufeng wang Xueping CollegeofEarthandEnvironmentalSciences NorthwestNormalUniversityLanzhou730070China ColdandAridRegionsEnvironmentalandEngineeringResearchInstitute CASLanzhou730000China SchoolofCivilEngineering LanzhouUniversityofTechnolog~Lanzhou730050China

The study employs slope, aspect, relief degree of land surface, land use, vegetation index, hydrology and climate, as evaluation indexes to set up the Human Settlements Environmental Index （HEI） model to evaluate the environmental suitability for human settlements in the Shiyang River Basin. By using GIS spatial analysis technology, such as spatial overlay analysis, buffer analysis and density analysis, the environmental suitability of the human set- tlement spatial situation and spatial pattern are established to analyze their spatial distribution The results show that the index of suitability for human settlements in the Shiyang River Basin is between 17.13 and 84.32. In general, suitability for human settlements decreases from the southwest to the northeast. Seen from an area pattern, the suitable region is mainly distributed in the Minqin oasis, Wuwei oasis and Changning basin, which are about 1080.01 km2 and account for 2.59% of the total area. Rather and comparatively suitable region is mainly distributed around the counties of Gulang, Yongchang and north of Tianzhu, which is about 1100.30 km2. The common suitable region is mainly distributed outside the counties of Yongchang, Jinchuan and most parts of Minqin County, which are about 23328.04 km2, accounting for 56.08% of the total area. The unsuitable region is mainly distributed upstream and to the north of the river, which is about 9937.60 km2, accounting for 23.89% of the total area. Meanwhile, the least suitable region is distributed around the Qilian Mountains, which are covered by snow and cold desert and lie in the intersecting area between the Tengger Desert and Badain Jaran Desert. The total area is about 6154.05 km2, accounting for 14.79% of the total area. Suitable regions for human habitation are mainly distributed around rivers in the form of ribbons and batches, while others are scattered. The distribution pattern is iden- tical to the residential spatial pattern. In addition, the relationships

关键词： geographic information systems suitability for human settlement arid inland area Shiyang RiverBasin

Roof filling control technology and application to mine roadway damage in small pit goaf

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International Journal of Mining Science and Technology 2019年第3期29卷 477-482页

作者： Weiyi Cai Zechao Chang Dongsheng Zhang xufeng wang Wenhao Cao Yazhou Zhou School of Mines China University of Mining & TechnologyXuzhou 221116China State Key Laboratory of Coal Resources and Safe Mining China University of Mining & TechnologyXuzhou 221116China Key Laboratory of Deep Coal Re-source Mining Ministry of Education of ChinaChina University of Mining & TechnologyXuzhou 221116China

To recover coal resources that have been damaged by traditional mining methods and ensure stability of the lower roadway in a small pit goaf,the goaf area must be filled and *** this research,the 1202 working face of the Hanzui mine is considered as an example for classifying the roof of the mining tunnel under the small kiln destruction zone,the effect of the goaf on the roadway is determined based on the radio tunnel penetration method,a mechanical model to determine the roof filling control mechanism was established,and the duct foaming system and roof filling process were *** results show that the scope and degree of influence of the goaf on the mining lane are large,but safe tunneling can be ensured through the use of a steel shed and advanced grouting *** the roof conditions are not similar,materials with different filling heights and filling strengths can be used to control the roof filling of the *** combining field experience and laboratory tests,it was determined that a high-foaming material with a water-cement ratio of 1:0.6,a suitable high-foaming additive,and a water volume ratio of 1:30 is cost-efficient for filling and meets the filling strength ***,the reliability of the proposed technology was verified by field experiments,which provide a reference for filling operations in similar mines.

关键词： Repeated mining Roadway roof control High foam material Filling mining

The uncertainty analysis of the MODIS GPP product in global maize croplands

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Frontiers of Earth Science 2018年第4期12卷 739-749页

作者： Xiaojuan HUANG Mingguo MA xufeng wang Xuguang TANG Hong YANG Chongqing Engineering Research Center for Remote Sensing Big Data Application Southwest UniversityChongqing 400715China Research Base of Karst Eco-environments at Nanchuan in Chongqing Ministry of Natural ResourcesSchool of Geographical SciencesSouthwest UniversityChongqing 400715China Northwest Institute of Eco-environment and Resources Chinese Academy of SciencesLanzhou 730000China Department of Geography and Environmental Science University of ReadingReading RG66ABUK

Gross primary productivity (GPP) is very important in the global carbon cycle. Currently, the newly released estimates of 8-day GPP at 500 m spatial resolution (Collection 6) are provided by the Moderate Resolution Imaging Spectroradiometer (MODIS) Land Science Team for the global land surface via the improved light use efficiency (LUE) model. However, few studies have evaluated its performance. In this study, the MODIS GPP products (GPPMOD) were compared with the observed GPP (GPPEC) values from site-level eddy covariance measurements over seven maize flux sites in different areas around the world. The results indicate that the annual GPPMOD was underestimated by 6%‒58% across sites. Nevertheless, after incorporating the parameters of the calibrated LUE, the measurements of meteorological variables and the reconstructed Fractional Photosynthetic Active Radiation (FPAR) into the GPPMOD algorithm in steps, the accuracies of GPPMOD estimates were improved greatly, albeit to varying degrees. The differences between the GPPMOD and the GPPEC were primarily due to the magnitude of LUE and FPAR. The underestimate of maize cropland LUE was a widespread problem which exerted the largest impact on the GPPMOD algorithm. In American and European sites, the performance of the FPAR exhibited distinct differences in capturing vegetation GPP during the growing season due to the canopy heterogeneity. In addition, at the DE-Kli site, the GPPMOD abruptly produced extreme low values during the growing season because of the contaminated FPAR from a continuous rainy season. After correcting the noise of the FPAR, the accuracy of the GPPMOD was improved by approximately 14%. Therefore, it is crucial to further improve the accuracy of global GPPMOD, especially for the maize crop ecosystem, to maintain food security and better understand global carbon cycle.

关键词： MODIS GPP eddy covariance maize cropland validation improvement

Underground pressure characteristics analysis in back-gully mining of shallow coal seam under a bedrock gully slope

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Mining Science and Technology 2011年第1期21卷 23-27页

作者： wang xufeng Zhang Dongsheng Fan Gangwei Zhang Chengguo School of Mines Chino University of Mining ＆ Technology Xuzhou 221116 China Stote Key Laboratory of Coal Resource and Mine Safety Chino University of Mining ＆ Technology Xuzhou 221008 Chin

我们在一个基岩溪谷斜坡下面在浅煤缝接在背溪谷采矿期间学习了地下的压力和它的机制，借助于物理模拟，数字建模并且地监视。结果证明地下的压力的紧张与它在 coalface 的相对位置有关。地下的压力是集中的，当 coalface 在溪谷的底部... 详细信息

我们在一个基岩溪谷斜坡下面在浅煤缝接在背溪谷采矿期间学习了地下的压力和它的机制，借助于物理模拟，数字建模并且地监视。结果证明地下的压力的紧张与它在 coalface 的相对位置有关。地下的压力是集中的，当 coalface 在溪谷的底部时，支持抵抗到达最大值，而地下的压力是中等的并且当 coalface 传递溪谷时，逐渐地减少。当斜坡在不稳定的、多边的块依赖了的采矿和形式组织的背溪谷期间在一个颠倒的方向旋转了到斜坡剧降时，这些变化的机制被分析，由于滑倒。当块破碎是小的时，多边的块的沉淀是可观的，导致在地下的压力的庞大的变化。随块身体的团的增加，块排水量将被减少与一起一增加在废矿由未破损的岩石和破岩石夹钳效果，导致地下的压力的减少。

关键词：压力特征煤层开采沟坡沟壑基岩采煤工作面浅埋开采机理

Stabilizing perovskite precursors with the reductive natural amino acid for printable mesoscopic perovskite solar cells

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Journal of Energy Chemistry 2024年第3期90卷 32-39,I0003页

作者： Wenjing Hu Jian Yang Chuang Yang xufeng Xiao Chaoyang wang Zhaozhen Cui Qiaojiao Gao Jianhang Qi Minghao Xia Yaqiong Su Anyi Mei Hongwei Han Michael Gratzel Center for Mesoscopic Solar Cells Wuhan National Laboratory for OptoelectronicsKey Laboratory of Materials Chemistry for Energy Conversion and Storage of Ministry of Education Huazhong University of Science and TechnologyWuhan 430074HubeiChina School of Chemistry Xi'an Key Laboratory of Sustainable Energy Materials ChemistryState Key Laboratory of Electrical Insulation and Power EquipmentXi'an Jiaotong UniversityXi'an 710049ShaanxiChina

Solution processability significantly advances the development of highly-efficient perovskite solar ***,the precursor solution tends to undergo irreversible degradation reactions,impairing the device performance and ***,we utilize a reductive natural amino acid,Nacetylcysteine(NALC),to stabilize the precursor solution for printable carbon-based hole-conductorfree mesoscopic perovskite solar *** find that I_(2) can be generated in the aged solution containing methylammonium iodide(MI) in an inert atmosphere and speed up the MA-FA^(+)(formamidinium) reaction which produces large-size cations and hinders the formation of perovskite *** effectively stabilizes the precursor via its sulfhydryl group which reduces I_(2) back to I^(-)and provides H^(+).The NALC-stabilized precursor which is aged for 1440 h leads to devices with a power conversion efficiency equivalent to 98% of that for devices prepared with the fresh ***,NALC improves the device power conversion efficiency from 16.16% to 18.41% along with enhanced stability under atmospheric conditions by modifying grain boundaries in perovskite films and reducing associated defects.

关键词： Perovskite solar cells Perovskite precursor Degradation Stabilization Reductive natural amino acid