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Democratizing photogrammetry:an accuracy perspective

Geo-Spatial Information Science 2023年第2期26卷 175-188页

作者： Jie Shan Zhixin Li damon lercel Kevan Tissue Joseph Hupy Joshua Carpenter School of Civil Engineering Purdue UniversityWest LafayetteINUSA School of Aviation and Transportation Technology Purdue UniversityWest LafayetteINUSA

Photogrammetry is experiencing an era of democratization mostly due to the popularity and availability of many commercial off-the-shelf devices,such as drones and *** are used as the most convenient and effective tools for high-resolution image acquisition for a wide range of applications in science,engineering,management,and cultural ***,the quality,particularly the geometric accuracy,of the outcomes from such consumer sensors is still ***,the expected quality under different control schemes has yet to be thoroughly *** paper intends to answer those questions with a comprehensive comparative ***,in particular,structure from motion,has been used to reconstruct a 3D building model from smartphone and consumer drone images,as well as from professional drone images,all under various ground control *** from this study show that the positioning accuracy of smartphone images under direct geo-referencing is 165.4 cm,however,this could be improved to 43.3 cm and 14.5 cm when introducing aerial lidar data and total station surveys as ground control,*** results are found for consumer drone images as *** comparison,this study shows the use of the professional drone is able to achieve a positioning accuracy of 3.7 ***,we demonstrate that through the combined use of drone and smartphone images we are able to obtain full coverage of the entire target with a 2.3 cm positioning *** study concludes that smartphone images can achieve an accuracy equivalent to consumer drone images and can be used as the primary data source for building facade data collection.

关键词： Drone smartphone photogrammetry Structure from Motion(SfM) aero triangulation point clouds

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A Solution to the C-Value Paradox and the Function of Junk DNA： The Genome Balance Hypothesis

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Molecular Plant 2015年第6期8卷 899-910页

作者： Michael Freeling Jie Xu Margaret Woodhouse damon Lisch Department of Plant and Microbial Biology University of California Berkeley CA 94720 USA Maize Research Institute Sichuan Agricultural University Wenjiang Sichuan 611130 China Department of Botany and Plant Pathology Purdue University West Lafayette IN 47907 USA

The Genome Balance Hypothesis originated from a recent study that provided a mechanism for the phenom- enon of genome dominance in ancient polyploids： unique 24nt RNA coverage near genes is greater in genes on the recessive subgenome irrespective of differences in gene expression. 24nt RNAs target transposons. Transposon position effects are now hypothesized to balance the expression of networked genes and pro- vide spring-like tension between pericentromeric heterochromatin and microtubules. The balance （coordi- nation） of gene expression and centromere movement is under selection. Our hypothesis states that this balance can be maintained by many or few transposons about equally well. We explain known balanced dis- tributions of junk DNA within genomes and between subgenomes in allopolyploids （and our hypothesis passes ＂the onion test＂ for any so-called solution to the C-value paradox）, importantly, when the allotetra- ploid maize chromosomes delete redundant genes, their nearby transposons are also lost; this result is ex- plained if transposons near genes function. The Genome Balance Hypothesis is hypothetical because the position effect mechanisms implicated are not proved to apply to all junk DNA, and the continuous nature of the centromeric and gene position effects have not yet been studied as a single phenomenon.

关键词： junk DNA transposons C-value paradox gene regulation balance

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Spheroidization behaviour of a Fe-enriched eutectic high-entropy alloy

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Journal of Materials Science & Technology 2020年第16期47卷 173-179页

作者： Yu Yin damon Kent Qiyang Tan Michael Bermingham Ming-Xing Zhang School of Mechanical and Mining Engineering the University of QueenslandSt LuciaQLD 4072Australia School of Science and Engineering University of the Sunshine CoastSippy DownsQLD 4556Australia

A cost-effective Fe-enriched eutectic high-entropy alloy(EHEA),Fe35Ni25Cr25Mo15,was designed and prepared to avoid the use of expensive Co that is commonly used in ***,the as-cast Feenriched EHEA was associated with *** present work aims to evaluate the possibility and feasibility of spheroidization of the lamellar structure of the EH EA in order to improve the *** to the high cooling rate of arc-melting,the as-melted Fe35Ni25Cr25Mo15 EHEA was found to be a pseudo eutectic alloy comprised of alternantσphase(Cr(0.22)Mo0.18Fe0.6-type intermetallic)and face centred cubic(FCC)*** lamellar structure in the Fe-enriched EHEA remained stable up to 800Κ.The instability of the lamellar structure occurred at temperatures over 800℃,which was resulted from migration of high-density faults(*** termination and ledges in the lamellae).However,the Fe35Ni25Cr25Mo15EHEA still exhibited brittleness even after spheroidization at 1100℃for 168 h due to the formation of the hard and brittleσmatrix in the pseudo Fe35Ni25Cr25Mo15 EHEA as a result of decomposition of the lamellar ***,in contrast to the softening of traditional eutectic alloys,spheroidization treatment was considered as invalid to improve the ductility of pseudo-eutectic HEA with high fraction of intermetallic *** present work provides a valuable re ference for those who aim to improve the ductility of brittle EHEA through spheroidization.

关键词： Eutectic high-entropy alloys Instability Lamellar structure Spheroidization Mechanical properties

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Ultrafast exciton relaxation dynamics of PbS and core/shell PbS/CdS quantum dots

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Science China Chemistry 2011年第12期54卷 2009-2015页

作者： WHEELER damon A FITZMORRIS Bob C ZHAO HaiGuang MA DongLing ZHANG JinZhong Department of Chemistry and Biochemistry University of California Santa Cruz CA 95064 USA Energy Materials and Telecommunications Center- Institui National de la Recherche Scientifique University of Quebec Varennes Qudbec Canada J3X-IS2

Optical properties and ultrafast exciton relaxation dynamics in PbS and core/shell PbS/CdS quantum dots(QDs) have been studied using UV-vis absorption and fluorescence spectroscopy as well as femtosecond(fs) transient absorption *** electronic absorption spectrum of the PbS QDs features broad absorption in the entire near IR-vis-UV region with a monotonic increase in intensity towards shorter *** to PbS,the absorption of the core/shell PbS/CdS QDs shows a slight blue shift in the 600?800 nm region,due to the decrease of the PbS crystal size caused by the synthetic process of the core/shell structure,and increased absorption near 400 nm due to the CdS *** PL of the PbS/CdS QDs was ~2.6 times more intense than that of the PbS QDs,due to surface passivation of PbS by CdS,and blue-shifted,attributable to smaller PbS size and thereby stronger quantum confinement in the core/shell *** transient absorption measurements of both systems showed a strong transient absorption feature from 600 to 750 nm following excitation at 750 *** transient absorption decays can be fit to a biexponential with time constants of 8 and 100 ps for PbS and 6 and 80 ps for PbS/*** amplitude and lifetime of the fast component were excitation intensity dependent,with the amplitude increasing more than linearly with increasing excitation intensity and the lifetime decreasing with increasing *** fast decay is attributed to exciton-exciton annihilation and it occurs more readily for the PbS/CdS than the PbS QDs,which is attributed to a lower density of trap states in the core/shell QDs,as supported by their stronger PL.

关键词： ultrafast femtosecond pump-probe spectroscopy PbS PbS/CdS

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Effects of deformation twinning on the mechanical properties of biodegradable Zn-Mg alloys

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Bioactive Materials 2019年第1期4卷 8-16页

作者： Shiyang Liu damon Kent Nghiem Doan Matthew Dargusch Gui Wang School of Mechanical and Mining Engineering The University of QueenslandSt Lucia4072Australia Centre for Advanced Materials Processing and Manufacturing(AMPAM) The University of QueenslandSt Lucia4072Australia School of Science and Engineering University of the Sunshine CoastMaroochydoreDC4558Australia ARC Research Hub for Advanced Manufacturing of Medical Devices The University of QueenslandSt Lucia4072Australia School of Dentistry and Oral Health Griffith UniversityGold Coast4215Australia

To satisfy the property requirements for biodegradable medical implants,Zn alloyed with low levels of Mg(≤0.8 wt%)has attracted increased research *** the present study,deformation twinning was observed in tensile tests and twinning appears to have an adverse impact on *** profuse twinning in the as-cast Zn-Mg alloys accelerated crack growth in tension due to twinning impingement which caused local stress concentrations and initiates ***-rolled Zn-Mg alloys have better ductility than their as-cast counterparts due to the inhibition of twinning by the refined Mg2Zn11 intermetallic phase and the finer grain size.

关键词： Biodegradable metals Zn-Mg alloys Deformation twinning Mechanical properties Hot rolling

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Deforming generalized cylinders without self-intersection by means of a parametric center curve

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Computational Visual Media 2018年第4期4卷 305-321页

作者： Ruibin Ma Qingyu Zhao Rui Wang James damon Julian Rosenman Stephen Pizer Computer Science University of North Carolina at Chapel Hill Mathematics University of North Carolina at Chapel Hill Radiation Oncology University of North Carolina at Chapel Hill

Large-scale deformations of a tubular object, or generalized cylinder, are often defined by a target shape for its center curve, typically using a parametric target curve. This task is non-trivial for free-form deformations or direct manipulation methods because it is hard to manually control the centerline by adjusting control points. Most skeleton-based methods are no better, again due to the small number of manually adjusted control points. In this paper, we propose a method to deform a generalized cylinder based on its skeleton composed of a centerline and orthogonal cross sections. Although we are not the first to use such a skeleton, we propose a novel skeletonization method that tries to minimize the number of intersections between neighboring cross sections by means of a relative curvature condition to detect intersections. The mesh deformation is first defined geometrically by deforming the centerline and mapping the cross sections. Rotation minimizing frames are used during mapping to control twisting. Secondly, given displacements on the cross sections, the deformation is decomposed into finely subdivided regions. We limit distortion at these vertices by minimizing an elastic thin shell bending energy,in linear time. Our method can handle complicated generalized cylinders such as the human colon.

关键词： generalized cylinder deformation skeleton self-intersection

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Influence of strain rate and crystallographic orientation on dynamic recrystallization of pure Zn during room-temperature compression

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Journal of Materials Science & Technology 2021年第27期86卷 237-250页

作者： Shiyang Liu damon Kent Hongyi Zhan Nghiem Doan Chang Wang Sen Yu Matthew Dargusch Gui Wang Queensland Centre for Advanced Materials Processing and Manufacturing School of Mechanical and Mining EngineeringThe University of QueenslandBrisbaneQLD4072Australia ARC Research Hub for Advanced Manufacturing of Medical Devices The University of QueenslandBrisbaneQLD4072Australia School of Science Technology and EngineeringUniversity of the Sunshine CoastMaroochydore DCQLD4558Australia China Science Lab General Motors Global Research&Development56 Jinwan RoadShanghai201206China School of Dentistry and Oral Health Griffith UniversityGold CoastQLD4215Australia Northwest Institute for Nonferrous Metal Research Shanxi Key Laboratory of Biomedical Metal Materials96 Weiyang RoadXi’an710016China

This work investigates the strain rate dependence of dynamic recrystallization behaviour of high-purity zinc in room temperature compression under strain rates of 10^(-4)s^(-1),10-2s^(-1)and 0.5 s^(-1).Results from electron backscatter diffraction provide insight into the deformation and dynamic recrystallization mechanisms *** dynamic recrystallization,twin-induced dynamic recrystallization,and discontinuous dynamic recrystallization are all active under compressive deformation at room *** to the high stacking fault energy of Zn,continuous dynamic recrystallization is the dominant mechanism while discontinuous dynamic recrystallization only operates in the early stages of compression at 10^(-4)s^(-1).Dynamic recrystallization kinetics are enhanced at higher strain rates(10^(-2)s^(-1)and 0.5s^(-1))due to an increased contribution from twin-induced dynamic *** present study reveals that the controlling mechanisms for continuous dynamic recrystallization are basalslip and 2ndorder pyramidalslip *** the activation of slip systems is mainly determined by crystallographic orientation,continuous dynamic recrystallization behaviour varies with grain orientation according to their propensity for basal and 2ndorder pyramidal slip.

关键词： Zinc Dynamic recrystallization Crystallographic orientation Schmid factor EBSD

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Mutator转座子及MULE在植物基因与基因组进化中的作用(英文)

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Acta Genetica Sinica 2006年第6期33卷 477-487页

作者：刁现民 damon Lisch 河北省农林科学院谷子研究所国家谷子改良中心石家庄050031 美国伯克力加州大学植物与微生物学系

Mutator(Mu)转座子是植物中已发现的转座最活跃的转座子,其高的转座频率及趋向于单拷贝功能基因转座的特性,使该转座子成为玉米功能基因克隆的主要方法。Mu转座子的同源类似因子广泛存在于被子植物基因组中,而且同一基因组中往往具有多... 详细信息

Mutator(Mu)转座子是植物中已发现的转座最活跃的转座子,其高的转座频率及趋向于单拷贝功能基因转座的特性,使该转座子成为玉米功能基因克隆的主要方法。Mu转座子的同源类似因子广泛存在于被子植物基因组中,而且同一基因组中往往具有多种变异类型。它不仅具有其他DNA转座子在基因和基因组进化中的普遍作用,而且具有能够承载基因组内功能基因和基因片段的载体功能,这种载体Mu转座子(Pack-MuLEs)能够在基因组内移动众多的基因片段,从而对基因和基因组进化产生作用。Mu转座子的同源序列发生在水稻与狗尾草之间的水平转移提供了高等植物核基因水平转移的首个例证。对Mu转座子的了解促进了我们对动态基因组概念的认识。文章对Mutator转座子的发现、转座特征、基因标签应用等的研究进展进行了综述,对Mu转座子家族的同源序列进行了分类,讨论了该转座子在基因组进化中的作用,分析了应加强研究的问题。

关键词： Mutator 转座子基因组进化 MuLE 载体Mu转座子

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Manufacturing of graded titanium scaffolds using a novel space holder technique

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Bioactive Materials 2017年第4期2卷 248-252页

作者： Yunhui Chen damon Kent Michael Bermingham Ali Dehghan-Manshadi Gui Wang Cuie Wen Matthew Dargusch Queensland Centre for Advanced Materials Processing and Manufacturing(AMPAM) The University of QueenslandSt.Lucia4072Australia School of Science and Engineering University of the Sunshine CoastMaroochydore DCQLD4558Australia ARC Research Hub for Advanced Manufacturing of Medical Devices Australia School of Engineering RMIT UniversityMelbourne3001Australia

To optimize both the mechanical and biological properties of titanium for biomedical implants,a highly flexible powder metallurgy approach is proposed to generate porous scaffolds with graded porosities and pore *** pellets acting as space holders were compacted with titanium powder and then removed by dissolution in water before *** morphology,pore structure,porosity and pore interconnectivity were observed by optical microscopy and *** results show that the porous titanium has porosity levels and pore size gradients consistent with their design with gradual and smooth transitions at the interfaces between regions of differing porosities and/or pore ***,the porous titanium has high interconnectivity between pores and highly spherical pore *** this article we show that this powder metallurgy processing technique,employing the novel sugar pellets as space-holders,can generate porous titanium foams with well-controlled graded porosities and pore *** method has excellent potential for producing porous titanium structures for hard tissue engineering applications.

关键词： Porous scaffolds Titanium Powder metallurgy Space holder Graded porosity

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A Dangerous Guy Indeed

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英语学习 1996年第6期 42-46页

作者： damon Runyon 陈辉

damon Runyon(1884—1946):美国作家及新闻记者,出生在堪萨斯州曼哈坦区。参加了1898年的美西战争。退役后,他开始了新闻写作,后转向报纸特写。他很擅长写短篇故事。他常采用现在时态,并自如地运用美国俚语及行话来描述纽约黑社会及百... 详细信息

damon Runyon(1884—1946):美国作家及新闻记者,出生在堪萨斯州曼哈坦区。参加了1898年的美西战争。退役后,他开始了新闻写作,后转向报纸特写。他很擅长写短篇故事。他常采用现在时态,并自如地运用美国俚语及行话来描述纽约黑社会及百老汇大街的生活。他的短篇故事生动有趣,因而广为人知。1941年后,他开始从

关键词：短篇故事 A Dangerous Guy Indeed

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