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A hierarchical indexing strategy for optimizing Apache Spark with HdFS to efficiently query big geospatial raster data

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International Journal of digital Earth 2020年第3期13卷 410-428页

作者： Fei Hu Chaowei Yang Yongyao Jiang Yun Li Weiwei Song daniel Q.duffy john L.Schnase Tsengdar Lee NSF Spatiotemporal Innovation Center and dept.of Geography and GeoInformation Sciences George Mason UniversityFairfaxVAUSA Center for Open-Source data and AI Technologies IBMSan FranciscoCAUSA Office of Computational and Information Sciences and Technology NASA Goddard Space Flight CenterGreenbeltMDUSA NASA Center for Climate Simulation Goddard Space Flight CenterGreenbeltMDUSA Earth Science division NASA HeadquartersWashingtonDCUSA

Earth observations and model simulations are generating big multidimensional array-based raster ***,it is difficult to efficiently query these big raster data due to the inconsistency among the geospatial raster data model,distributed physical data storage model,and the data pipeline in distributed computing *** efficiently process big geospatial data,this paper proposes a three-layer hierarchical indexing strategy to optimize Apache Spark with Hadoop distributed File System(HdFS)from the following aspects:(1)improve I/O efficiency by adopting the chunking data structure;(2)keep the workload balance and high data locality by building the global index(k-d tree);(3)enable Spark and HdFS to natively support geospatial raster data formats(e.g.,HdF4,NetCdF4,GeoTiff)by building the local index(hash table);(4)index the in-memory data to further improve geospatial data queries;(5)develop a data repartition strategy to tune the query parallelism while keeping high data *** above strategies are implemented by developing the customized Rdds,and evaluated by comparing the performance with that of Spark SQL and *** proposed indexing strategy can be applied to other distributed frameworks or cloud-based computing systems to natively support big geospatial data query with high efficiency.

关键词： Big data hierarchical indexing multi-dimensional Apache Spark HdFS distributed computing GIS

direct laser writing of volumetric gradient index lenses and waveguides

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Light(Science & Applications) 2020年第1期9卷 89-102页

作者： Christian R.Ocier Corey A.Richards daniel A.Bacon-Brown Qing ding Raman Kumar Tanner J.Garcia Jorik van de Groep Jung-Hwan Song Austin J.Cyphersmith Andrew Rhode Andrea N.Perry Alexander J.Littlefield Jinlong Zhu dajie Xie Haibo Gao Jonah F.Messinger Mark L.Brongersma Kimani C.Toussaint Jr Lynford L.goddard Paul V.Braun department of Materials Science and Engineering University of Illinois at Urbana-ChampaignUrbanaILUSA Materials Research Laboratory University of Illinois at Urbana-ChampaignUrbanaILUSA Beckman Institute for Advanced Science and Technology University of Illinois at Urbana-ChampaignUrbanaILUSA department of Electrical and Computer Engineering University of Illinois at Urbana-ChampaignUrbanaILUSA department of Materials Science and Engineering Stanford UniversityStanfordCAUSA Carl R.Woese Institute for Genomic Biology University of Illinois at Urbana-ChampaignUrbanaILUSA department of Mechanical Science and Engineering University of Illinois at Urbana-ChampaignUrbanaILUSA

direct laser writing(dLW)has been shown to render 3d polymeric optical components,including lenses,beam expanders,and mirrors,with submicrometer ***,these printed structures are limited to the refractive index and dispersive properties of the ***,we present the subsurface controllable refractive index via beam exposure(SCRIBE)method,a lithographic approach that enables the tuning of the refractive index over a range of greater than 0.3 by performing dLW inside photoresist-filled nanoporous silicon and silica *** the laser exposure during printing enables 3d submicron control of the polymer infilling and thus the refractive index and chromatic *** SCRIBE’s unprecedented index range and 3d writing accuracy has realized the world’s smallest(15μm diameter)spherical Luneburg lens operating at visible ***’s ability to tune the chromatic dispersion alongside the refractive index was leveraged to render achromatic doublets in a single printing step,eliminating the need for multiple photoresins and writing *** also has the potential to form multicomponent optics by cascading optical elements within a *** a demonstration,stacked focusing structures that generate photonic nanojets were fabricated inside porous ***,an all-pass ring resonator was coupled to a subsurface 3d *** measured quality factor of 4600 at 1550 nm suggests the possibility of compact photonic systems with optical interconnects that traverse multiple *** is uniquely suited for constructing such photonic integrated circuits due to its ability to integrate multiple optical components,including lenses and waveguides,without additional printed supports.

关键词： index refractive render

Impacts of climate gradients on the vegetation phenology of major land use types in Central Asia （1981-2008）

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Frontiers of Earth Science 2012年第2期6卷 206-225页

作者： Jahan KARIYEVA Willem J.d. van LEEUWEN Connie A. WOOdHOUSE School of Geography and development The University of Arizona Tucson AZ 85721 USA School of Natural Resources and the Environment - Office of Arid Lands Studies - Arizona Remote Sensing Center The University of Arizona Tucson AZ 85721 USA

Time-series of land surface phenology （LSP） data offer insights about vegetation growth patterns. They can be generated by exploiting the temporal and spectral reflectance properties of land surface components. Inter- annual and seasonal LSP data are important for under- standing and predicting an ecosystem＇s response to variations caused by natural and anthropogenic drivers. This research examines spatio-temporal change patterns and interactions between terrestrial phenology and 28 years of climate dynamics in Central Asia. Long-term （1981-2008） LSP records such as timing of the start, peak and length of the growing season and vegetation productivity were derived from remotely sensed vegetation greenness data. The patterns were analyzed to identify and characterize the impact of climate drivers at regional scales. We explored the relationships between phenologi- cal and precipitation and temperature variables for three generalized land use types that were exposed to decade- long regional drought events and intensified land and water resource use： rainfed agriculture, irrigated agriculture, and non-agriculture. To determine whether and how LSP dynamics are associated with climate patterns, a series of simple linear regression analyses between these two variables was executed. The three land use classes showed unique phenological responses to climate variation across Central Asia. Most of the phenological response variables were shown to be positively correlated to precipitation and negatively correlated to temperature. The most substantial climate variable affecting phenological responses of all three land use classes was a spring temperature regime. These results indicate that future higher temperatures would cause earlier and longer growing seasons.

关键词： phenology land use climate variability

Reductions in productivity due to land degradation in the drylands of the southwestern United States

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Ecosystem Health and Sustainability 2015年第8期1卷 14-29页

作者： Praveen Noojipady Stephen d.Prince Khaldoun Rishmawi department of Geographical Sciences University of MarylandCollege Park Maryland 20742 USA Biospheric Sciences Laboratory NASA/Goddard Space Flight CenterGreenbelt Maryland 20771 USA The Applied Research Institute JerusalemP.O.Box 860Karm Mu'ammarKarkafeh StBethlehemPalestine

dryland degradation has long been recognized at regional,national,and global scales,yet there are no objective assessments of its location and *** assessment of reductions in net primary production(NPP)due to dry land degradation in the southwestern United States is *** local NPP scaling(LNS)approach was applied to map the extent and magnitude of degrada *** seeks to identifty reference sites in which there is no degradation that can be used as a standard for comparison with other sites that share the same environment,except for *** years were analyzed(2000--2011),using Normalized difference Vegetation Index(NdVI)data(250 m)from the Moderate Resolution Imaging Spectroradiometer(MOdIS)satellite-borne multispectral *** results indicated that the total NPP reductions in the study area were about35.9±4.7Tg C/yr,which equates to 0.31±0.04 Mg C·ha^(-1)· yr^(-1).The NPP reductions in grassland-savanna and livestock grazing areas were large and mostly consistent between years in spite of large variations in overall NPP caused by differences in land-use,interannual variations in rainfall,and other aspects of *** comparison with other cover types,forested land generally had higher NPP reduction per unit *** maps also enable attribution of degradation from the finest management units to entire agencies,such as the Bureau of Land Management,which had 50%less production per unit area than the *** *** degradation within Native American land was low with total NPP reduction of about 2.41±0.24 Tg C/yr and unit area reduction of productivity of just 0.21±0.02 Mg C·ha^(-1)·yr^(-1),yet the percent reduction from potential was in equivalence with other land management agencies.

关键词： degradation drylands ecosystem health MOdIS NdVI NPP rangelands reference conditions southwestern United States.

Mid-infrared hyperchaos of interband cascade lasers

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Light(Science & Applications) 2022年第1期11卷 69-78页

作者： Yu deng Zhuo-Fei Fan Bin-Bin Zhao Xing-Guang Wang Shiyuan Zhao Jiagui Wu Frédéric Grillot Cheng Wang School of Information Science and Technology ShanghaiTech UniversityShanghai 201210China LTCI Institut Polytechnique de ParisTélécom Paris19 place Marguerite Perey91120 PalaiseauFrance School of Physical Science and Technology Southwest UniversityChongqing 400715China Center for High Technology Materials University of New-Mexico1313 Goddard St SEAlbuquerqueNM 87106USA Shanghai Engineering Research Center of Energy Efficient and Custom AI IC ShanghaiTech UniversityShanghai 201210China

Chaos in nonlinear dynamical systems is featured with irregular appearance and with high sensitivity to initial ***-infrared light chaos based on semiconductor lasers has been extensively studied and has enabled various ***,we report a fully-developed hyperchaos in the mid-infrared regime,which is produced from interband cascade lasers subject to the external optical *** spectrum analysis demonstrates that the chaos exhibits three positive Lyapunov ***,the chaotic signal covers a broad frequency range up to the GHz level,which is two to three orders of magnitude broader than existed mid-infrared chaos *** interband cascade lasers produce either periodic oscillations or low-frequency fluctuations before bifurcating to *** hyperchaos source is valuable for developing long-reach secure optical communication links and remote chaotic Lidar systems,taking advantage of the high-transmission windows of the atmosphere in the mid-infrared regime.

关键词： chaos chaotic hyperchaos

PRELIMINARY ANALYSIS OF THE ATMOSPHERIC RAdIATIVE HEATING FIELdS IN AUTUMN IN THE MId LATITUdE ARId AREAS OF CHINA

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Acta meteorologica Sinica 1992年第1期6卷 105-116页

作者：季国良 K.N.Liou S.C.Ou M.d.Chou Lanzhou Institute of Plateau Atmospheric Physics Academia SinicaLanzhou department of Meteorology University of UtahU.S.A. Laboratory for Atmospheres NASA/Goddard Space Flight CenterU.S.A.

A parameterized radiation and cloud model developed at the University of Utah,*** been used to compute the atmospheric radiative properties in Zhangye area during the pilot experiment of HEIFE in September of *** characteristics of atmospheric radiative heating fields during the autumn in Zhangye area have been analysed,and some questions that merit attention in the future observation are also discussed in this paper.

关键词： parameterized radiation and cloud model radiation transfer solar radiation heating rate infrared cooling rate

维普期刊数据库

通过实验表征、计算机辅助结构解析和原子模拟对切尔西土壤腐植酸进行三维结构模拟

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腐植酸 2022年第5期 60-75页

作者： Mamadou S.diallo Andre Simpson Paul Gassman Jean Loup Faulon James H.johnson William A.goddard Patrick G.Hatcher 袁飞巩冠群(译) 加州理工学院贝克曼研究所139-74材料和工艺模拟中心加利福尼亚州帕萨迪纳91125 霍华德大学土木工程系华盛顿特区20059 多伦多大学斯卡伯勒学院物理科学系加拿大多伦多MIC 1A4 太平洋西北国家实验室环境分子科学实验室华盛顿州里奇兰99352 桑迪亚国家实验室计算生物学和进化计算部加利福尼亚州利弗莫尔94551-0969 俄亥俄州立大学化学系俄亥俄州哥伦布43210 中国矿业大学化工学院徐州221116

本文描述了一个用于开发腐植酸(HAs)三维结构模型的完整的实验和计算框架。这种方法结合了实验表征、计算机辅助结构解析(CASE)和原子模拟,生成与HAs的分析数据和热力学/结构特性相一致的所有三维结构模型或这些模型的代表性样本。从元... 详细信息

本文描述了一个用于开发腐植酸(HAs)三维结构模型的完整的实验和计算框架。这种方法结合了实验表征、计算机辅助结构解析(CASE)和原子模拟,生成与HAs的分析数据和热力学/结构特性相一致的所有三维结构模型或这些模型的代表性样本。从元素分析、漫反射傅里叶变换红外光谱、一维/二维~1H和C溶液核磁共振光谱和电喷雾电离四极杆飞行时间质谱(ESI QqTOF MS)中获得的结构数据,结合CASE程序SIGNATURE,生成了切尔西土壤腐植酸(HA)所有的三维结构模型。这些模型随后被用作初始三维结构,进行恒温恒压分子动力学模拟,以估算其体密度和Hildebrand溶解度参数。只有少数模型异构体显示出的分子组成和体热力学性质与实验数据一致。这些模型异构体的等摩尔混合物的模拟C核磁共振光谱与切尔西土壤HA的实测光谱相比有较好的一致性。

关键词：土壤多肽和蛋白质分子模拟碳水化合物核磁共振光谱

维普期刊数据库

TWO LARGE OVARIAN CYSTS

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Chinese Medical Journal 1934年第7期48卷

作者： F.W.goddard M.d.Shaoshing Chekiang.

In this city of Shaoshing,Chekiang,modern medicine has beenpractised less than thirty years and is still far from having establishedits hold on the majority of the *** conditions,notably variouskinds of tumors,are neglected to an almost unbelievable extent,andfor this reason a report of the successful removal of two large ovariancysts may be of general *** Ⅰ.Patient was a married woman 22 years of age,621/2 inches inheight,with her abdomen so enormously distended with fluid that,she was ableto walk only by leaning on a chair which she pushed ahead of *** at the level of its greatest girth measured 67 inches,the umbilicus

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Spatio-temporal snowmelt variability across the headwaters of the Southern Rocky Mountains

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Frontiers of Earth Science 2017年第3期11卷 505-514页

作者： S.R. FASSNACHT J.I. LOPEZ-MORENO C. MA A.N. WEBER A.K.d. PFOHL S.K. KAMPF M. KAPPAS ESS-Watershed Science Colorado State University Fort Collins CO 80523-1476 USA Cooperative Institute for Research in the Atmosphere Fort Collins CO 80523-1375 USA Geospatial Centroid at CSU Fort Collins CO 80523-1019 USA Natural Resources Ecology Laboratory Fort Collins CO 80523-1499 USA Geographisches Institut Georg-August-Universitat Gottingen 37077 Gottingen Germany Instituto Pirenaico de Ecologia CSIC Campus de Aula Dei 50080 Zaragoza Spain EASC-Watershed Science Colorado State University Fort Collins CO 80523-1482 USA

Understanding the rate of snowmelt helps inform how water stored as snow will transform into streamflow. data from 87 snow telemetry （SNOTEL） stations across the Southern Rocky Mountains were used to estimate spatio-temporal melt factors. decreases in snow water equivalent were correlated to temperature at these monitoring stations for eight half-month periods from early March through late June. Time explained 70% of the variance in the computed snow melt factors. A residual linear correlation model was used to explain subsequent spatial variability. Longitude, slope, and land cover type explained further variance. For evergreen trees, canopy density was relevant to find enhanced melt rates; while for all other land cover types, denoted as non- evergreen, lower melt rates were found at high elevation, high latitude and north facing slopes, denoting that in cold environments melting is less effective than in milder sites. A change in the temperature sensor about mid-way through the time series （1990 to 2013） created a discontinuity in the temperature dataset. An adjustment to the time series yield larger computed melt factors.

关键词： melt SWE temperatutre SNOTEL tempera-ture sensor change