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Ground target localization of unmanned aerial vehicle based on scene matching

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High Technology Letters 2024年第3期30卷 231-243页

作者： ZHANG Yan chen yukun HUANG He TANG Simi LI Zhi Beijing Yansou Technology Co. Ltd.Beijing 100085P.R.China The 15th Research Institute of China Electronics Technology Group Corporation Beijing 100083P.R.China

In order to improve target localization precision,accuracy,execution efficiency,and application range of the unmanned aerial vehicle(UAV)based on scene matching,a ground target localization method for unmanned aerial vehicle based on scene matching(GTLUAVSM)is *** sugges-ted approach entails completing scene matching through a feature matching ***,multi-sensor registration is optimized by robust estimation based on homologous ***,basemap generation and model solution are utilized to improve basemap correspondence and accom-plish aerial image *** evidence and experimental verification demonstrate that GTLUAVSM can improve localization accuracy,speed,and precision while minimizing reliance on task equipment.

关键词： scene matching basemap adjustment feature registration random sample con-sensus(RANSAC) unmanned aerial vehicle(UAV)

A new approach for high fidelity seismic data recovery by fractal interpolation

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Earthquake Science 2012年第4期25卷 339-346页

作者： Hongyan Liu Tongjiang He yukun chen Xinfu Li Earthquake Administration of Tianjin Municipality School of Geophysics and Information Technology China University of Geosciences

Recovering accurate data is important for both earthquake and exploration seismology studies when data are sparsely sampled or partially missing. We present a method that allows for precise and accurate recovery of seismic data using a localized fractal recovery method. This method requires that the data are self- similar on local and global spatial scales. We present examples that show that the intrinsic structure associated with seismic data can be easily and accurately recovered by using this approach. This result, in turn, indicates that seismic data are indeed self-similar on local and global scales. This method is applicable not only for seismic studies, but also for any field studies that require accurate recovery of data from sparsely sampled datasets with partially missing data. Our ability to recover the missing data with high fidelity and accuracy will qualitatively improve the images of seismic tomography.

关键词： fractal interpolation seismic data recovery high-fidellty seismic tomography

Architectural Model of a Dryland Gravel Braided River,based on 3D UAV Oblique Photogrammetric Data:A Case Study of West Dalongkou River in Eastern Xinjiang,China

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Acta Geologica Sinica(English Edition) 2023年第1期97卷 269-285页

作者： YIN Senlin ZHU Baiyu GUO Haiping XU Zhenhua LI Xiaoshan WU Xiaojun chen yukun JIANG Zhibin Institute of Mud-Logging Technology and Engineering Yangtze UniversityJingzhouHubei 434023China Research Institute of Exploration and Development PetroChina Xinjiang Oilfield CompanyKaramayXinjiang 834000China School of GeoSciences Yangtze UniversityWuhan 430100China

Three-dimensional unmanned aerial vehicle(UAV)oblique photogrammetric data were used to infer mountainous gravel braided river lithofacies,lithofacies associations and architectural *** architecture and lithofacies associations with detailed lithofacies characterizations were comprehensively described to document the architectural model,architectural element scale and gravel particle scale.(1)Nine lithofacies(i.e.,Gmm,Gcm,Gcc,Gci,Gcl,Ss,Sm,Fsm and Fl)were identified and classified as gravel,sand and fine matrix *** are typical depositional features of a mountainous dryland gravel-braided river.(2)Three architectural elements were identified,including channel(CH),gravel bar(GB)and overbank(OB).CH can be further divided into flow channel and abandoned channel,while GB consists of Central Gravel bar(CGB)and Margin Gravel bar(MGB).(3)The gravel bar is the key architectural element of the gravel braided river,with its geological *** dimensions of GBs and their particles are various,but exhibit good relationships with each *** grain size of GB decreases downstream,but the dimensions of GB do *** bank erosion affects the GB dimensions,whereas channel incision and water flow velocity influence the grain size of *** conclusions can be applied to the dryland gravel braided river studies in tectonically active areas.

关键词： three-dimensional UAV oblique photogrammetry gravel braided river architecture modern deposits West Dalongkou River

A novel pore-fracture dual network modeling method considering dynamic cracking and its applications

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Petroleum Research 2020年第2期5卷 164-169页

作者： yukun chen Kai Yan Jigang Zhang Runxi Leng Hongjie cheng Xuhui Zhang Hongxian Liu Weifeng Lyu PetroChina Xinjiang Oilfield Research Institute of Exploration and DevelopmentKaramayXinjiang843000China College of Mechanical and Transportation Engineering China University of Petroleum(Beijing)Beijing102249China Institute of Mechanics Chinese Academy of SciencesBeijing100190China Department of Petroleum Engineering China University of Petroleum-Beijing at KaramayKaramayXinjiang834000China State Key Laboratory of Enhance Oil Recovery Research Institute of Petroleum Exploration and DevelopmentPetroChinaBeijing100083China

Unconventional reservoirs are normally characterized by dual porous media, which has both multi-scalepore and fracture structures, such as low permeability or tight oil reservoirs. The seepage characteristicsof such reservoirs is mainly determined by micro-fractures, but conventional laboratory experimentalmethods are difficult to measure it, which is attribute to the dynamic cracking of these *** emerging digital core technology in recent years can solve this problem by developing an accuratepore network model and a rational simulation approach. In this study, a novel pore-fracture dualnetwork model was established based on percolation theory. Fluid flow in the pore of two scales, microfracture and matrix pore, were considered, also with the impact of micro-fracture opening and closingduring flow. Some seepage characteristic parameters, such as fluid saturations, capillary pressure, relative permeabilities, displacement efficiency in different flow stage, can be predicted by proposedcalculating method. Through these work, seepage characteristics of dual porous media can be achieved.

关键词： Pore-fracture dual network model Micro-fracture Dynamic cracking Digital core Dimensionless parameters Seepage characteristics

Ventricular remodeling and intervention with losartan following rabbit chronic hibernating myocardium

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上海医学 2007年第S1期30卷 64-65页

作者： chen Yan, ZHANG Feilong, LUO yukun, chen Lianglong. Union Hospital, Fujian Medical University & Fujian Provincial Institute of Coronary Disease, Fuzhou 350001, China

Objectives To explore the changes of myocyte and the interstitial collagen in a model of chronic hibernating myocardium (CHM) in rabbits, and to determine whether these alterations affect the cardiac function, and to further observe the effects of losartan on ventricular remodeling. Methods A left anterior descending (LAD) coronary artery stenosis was created and maintained for 4 weeks to create a CHM model in rabbits. Thirty-six rabbits were assigned to the following three groups(12 rabbits per group): CHM for 4 weeks(CHM group), low-dose of losartan intervention group for 4 weeks(LTl group, 10 mg·kg-1·d-1), high-dose of losartan intervention group for 4 weeks (LT2 group, 30 mg·kg-1·d-1); and 12 sham-operated rabbits served as controls (SO group). A microscopic imaging system (Image-Pro Plus, Olympus) was used to assess the Interstitial collagen volume fraction (ICVF) in myocardial sections with picrosirius-red staining, and a polarized light microscopy to qualitatively analysis the changes in the type and the proportion of collagen fibers, to semi-quantitatively score the proportion of collagen I to collagen III(PI/III). The expression of MMP-2, 9 and TIMP-2 was assessed by immunohistochemistry and western bloting. The myocyte apoptosis rate (Rapo) was calculated with TUNEL-staining. And echocardiography was performed to measure left ventricular end-systolic and end-diastolic diameter (LVESD, LVEED), and left ventricular short-axis fraction shortening (LVFS) and ejection fraction (LVEF). Results The animal model of CHM was induced successfully in 36 out of 39-rabbits and maintained for 28 days. Compared with the sham group, ICVF) was significantly increased (P<0.01) in CHM group; compared with CHM group, ICVF was significantly decreased (P<0.01,each) in LTl group and LT2 group, and the change were more remarkable in LT2 group, compared to LTl group(P<0.05). Compared with sham group, PI/IH was significantly increased (P < 0.01) in CHM group; compared wi

关键词： remodeling myocardium myocyte collagen rabbit interstitial descending ejection LVESD TIMP

Quantitative Seismic Risk Evaluation on Blind Faults in Offshore Areas of Tianjin,China

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Earthquake Research in China 2013年第4期27卷 542-552页

作者： Liu Hongyan chen yukun Yan chengguo Yang Fei Earthquake Administration of Tianjin Municipality

Based on faults surveying and research data in the Tianjin offshore areas,through studying tectonic structure,Quaternary activity,deep structure,stress and strain fields and seismicity in the Tianjin offshore areas,the activity and tectonic features of the faults are determined *** seismo-geological data,and the historical and modern seismicity data,the frequency-magnitude relationship model normalized by 500a is established and based on the relationship between the upper limit of maximum magnitude M u and a t/b,the maximum magnitudes of the sea section of the Haihe river fault and the Haiyi fault are *** Poisson probability model is adopted and the quantitative parameters,such as the maximum magnitude,occurrence probability,recurrence cycle of the faults in the south Tianjin offshore areas in the coming 50～200a,are calculated.

关键词： Seismic risk Quantitative evaluation Fault sub-area Frequency-magnituderelationship Maximum magnitude Occurrence probability Recurrenceperiod

Application of Acoustic Technique to Surveying a Buried Fault in Tianjin

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Earthquake Research in China 2008年第3期22卷 304-316页

作者： chen yukun Zheng Yanpeng Gao Wuping Wang Zhisheng Earthquake Administration of Tianjin Municipality Tianjin 300201 China First Institute of Oceanography SOA Qingdao 266003 China

We carried out surveying on the shallow structure and faulted-stratum of the Haihe fault in Tianjin using acoustic surveying methods such as the single-channel seismic technique. The result shows that the method can obtain satisfactory results in wide and deep river courses. It also shows that in the Tanggu area of Tianjin, the upper fault point of Haihe fault is about 30m beneath the river bed and the corresponding latest active period is Qp^3- Qh^1 , which is consistent with the former borehole survey result. In the offshore area of the Bohai Sea, Haihe fault shows as a NWW-NEE strike dense fault zone and its upper fault point is less than 30m beneath the seabed. It shows that the active characteristics of Haihe fault in the Bohai Sea correspond to the Tanggu area.

关键词： Acoustic exploration Seismic reflection wave groups Marine strata Haihe fault

A Study on the Quaternary Activity of the Tianjin Fault

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Earthquake Research in China 2010年第3期24卷 353-362页

作者： Shao Yongxin Li Zhenhai chen yukun Ren Feng Yao Zhengquan Earthquake Administration of Tianjin Municipality Tianjin 300201 China State Key Laboratory of Loess and Quaternary Geology Institute of Earth Environment CAS Xi＇an 710075 China

The Tianjin fault includes South Tianjin fault and North Tianjin fault. Based on the results of artificial seismic exploration,four borehole profiles were laid out respectively west of Jinghai county town,Chaomidian village of Xiqing district,Xiaonanhe village of Xiqing district and Zhutoudian village of Ninghe county,to implement the exploration of these faults. Through identification of microfossils,the locations of marine beds in boreholes were obtained in this work,and through stratigraphic dating,the ages of the first,second and third marine beds were determined. Through strata correlation with the marine beds as key marker beds and integrating with the test results of paleo geomagnetism of boreholes BZ2 and TN3,the activity in the North and South Tianjin faults was analyzed and studied. The results indicate that there is no evidence of movement of the South Tianjin fault since the Late Pleistocene,but may have had weak activity before the Middle Pleistocene. No evidence of activity in the North Tianjin fault was found since the Late Pleistocene either,but might have been active in the early stage of the Early Pleistocene. These show that the activity of the South Tianjin fault is stronger than that of the North Tianjin fault. At the same time,we find that the second,third and fourth marine beds are lacking to some extent in different areas. So,before they are used in strata correlation, the age of marine beds must be determined,otherwise the results of strata correlation may lead to errors. For the second marine bed,where there has been dispute about its age,we consider the age to be about 70ka.

关键词： Tianjin fault Marine bed Stratigraphic correlation Fault activity

Thermal and Thermo-oxidative Degradation of Flame Retardant High Impact Polystyrene with Triphenyl Phosphate and Novolac Epoxy Resin

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Journal of Wuhan University of Technology(Materials Science) 2007年第3期22卷 486-489页

作者：李慧勇贾德民 College of Materials Science and Engineering South China University of Technology

Thermal and thermo-oxidative decomposition and decomposition kinetics of flame retardant high impact polystyrene （HIPS） with triphenyl phosphate （TPP） and novolac type epoxy resin （NE） were characterized using thermo-gravimetric experiment. And the flammability was determined by limited oxygen indices （LOI）. The LOI results show that TPP and NE had a good synthetic effect on the flame retardancy of HIPS. Compared with pure HIPS, the LOI values of HIPS/NE and HIPS/TPP only increased by about 5%, and the LOI value of HIPS/TPP/NE reached 42.3%, nearly 23% above that of HIPS. All materials showed one main decomposition step, as radical HIPS scission predominated during anaerobic decomposition. TPP increased the activity energy effectively while NE affected the thermal-oxidative degradation more with the help of the char formation. With both TPP and NE, the materials could have a comparable good result of both thermal and thermal-oxidative degradation, which could contribute to their effect on the flame retardancy.

关键词： high impact polystyrene flame retardant thermal degradation thermo-oxidative degradation