Remote sensing heritage in a petabyte-scale: satellite data and heritage Earth Engine© applications

ABSTRACT

This paper aims to demonstrate results and considerations regarding the use of remote sensing big data for archaeological and Cultural Heritage management large scale applications. For this purpose, the Earth Engine© developed by Google© was exploited. Earth Engine© provides a robust and expandable cloud platform where several freely distributed remote sensing big data, such as Landsat, can be accessed, analysed and visualized. Two different applications are presented here as follows: the first one is based on the evaluation of multi-temporal Landsat series datasets for the detection of buried Neolithic tells (‘magoules’) in the area of Thessaly, in Greece using linear orthogonal equations. The second case exploits European scale multi-temporal DMSP-OLS Night-time Lights Time Series to visualize the impact of urban sprawl in the vicinity of UNESCO World Heritage sites and monuments. Both applications highlight the considerable opportunities that big data can offer to the fields of archaeology and Cultural Heritage, while the studies also demonstrate the great challenges that still are needed to be overcome in order to make the exploitation of big data process manageable and fruitful for future applications.     

An orthogonal least-square-based method for DEM generalization

A new method based on orthogonal least square (OLS) of multiquadric algorithm (MOLS) is proposed for digital elevation model (DEM) generalization by the retrieval of critical points from a grid-based DEM to construct a triangulated irregular network surface. The focus is on the method for accurately obtaining the critical points, which maximally retain the important terrain feature lines. The grid-based DEM to be generalized is first approximated in terms of multiquadric method, and then the significances of the grids are assessed based on OLS method with the merit that each selected grid point gives the maximal increment to the explained variance of the desired output. We used six study sites with different terrain complexities to comparatively analyze the generalization accuracies of MOLS and the classical methods including very important method and point-additive method (Latticetin) under different numbers of retrieved significant points. The results indicate that MOLS averagely performs better than the classical methods for the original DEM generalization in terms of root mean square error. The analytical results also show that MOLS has the better ability in maintaining the feature lines inherent in the original DEM than the classical methods in terms of streamline matching rate. The perfect performance of the newly proposed method can be attributed to the high accuracy of multiquadric method for surface approximation and the effectiveness of OLS for point significance assessment.     

从金银花中提取绿原酸的工艺研究

用不同浓度的乙醇从金银花中提取绿原酸,以正交实验进行优化工艺研究,采用紫外分光光度法测定提取液中绿原酸的含量,探讨了乙醇浓度、乙醇倍量、回流时间、pH值、浸泡温度对绿原酸含量的影响。实验结果表明,最佳的工艺条件是:10倍量50%乙醇为浸提剂,浸泡温度为70℃,pH=7,回流时间为1h,提取次数为2次。     

酶法水解中国毛虾的研究(英文)

比较了4种常用蛋白酶对中国毛虾的酶解效果,筛选出胰蛋白酶和枯草杆菌蛋白酶为最佳用酶,并利用正交试验优化了水解条件,在各自最佳水解条件下采用先加胰蛋白酶再加枯草杆菌蛋白酶的酶解方式对中国毛虾进行联合双酶水解,水解度可达67 .83%。     

Parameter evaluation and optimization for multi-resolution segmentation in object-based shadow detection using very high resolution imagery

Object-based shadow detection in urban areas is an important topic in very high resolution remote sensing image processing. Multi-resolution segmentation (MRS) is an effective segmentation method, and is used for object-based shadow detection. However, several input parameters within MRS may result in unstable performance for final shadow detection; thus, the evaluation and optimization for the parameters upon the final shadow detection accuracy cannot be overlooked. In this paper, the three parameters in MRS (scale s, weight of colour w_color and weight of compactness w_compact) upon the final result of a recently proposed method, object-based shadow detection with Dempster–Shafer theory, were evaluated and optimized by sensitivity analysis and Taguchi’s method with three experimental data. Experiments show that scale s is the most sensitive parameter among the three parameters within MRS. More importantly, according to the Taguchi’s method theory, there is a very significant interaction effect between s and w_color, which cannot be overlooked. The shadow detection accuracy yielded by the optimum parameter combination in consideration of the interaction effect is higher than that only optimized by covering the main effect of single parameter in most cases.     

基于正交实验的卧式浪流发电轮机叶片分析

基于现有波浪能和潮流能发电装置研究现状,为达到波浪和潮流同时利用的目的,设计了一种以卧式轮机形式同时吸收水平波浪螺旋力和潮流能动力的新型浪流发电装置。通过正交试验设计得到三指标最佳叶片参数组合后,进行FLUENT流场分析,从流体角度出发,在其扭矩、推力以及轮机功率三方面对比分析,阐明了叶片参数对于轮机流场的作用趋势,并以此趋势为参考择出最佳模型。后期水槽实验有效验证了该卧式浪流轮机的浪流结合吸收的可行性。     

水敏性地层钻探泥浆性能优化及配制

依据河南许昌地热井水敏性地层钻探工程,在分析水敏性地层的成分、水化机理及钻进泥浆性能需求的基础上,确定水敏性地层钻进需要滤失量小、密度低、流变性好、抑制性强的泥浆。依据文献资料及生产实践经验,初步选出配制泥浆的材料和浓度,采用室内试验测定泥浆性能和正交试验极差分析法优选泥浆材料浓度,优化出泥浆最终的配比,经生产实践验证调整,最终确定了适应项目生产需求的泥浆配方。经实际生产检验,满足水敏性地层钻探需求,效果良好。     

正交混凝试验在矿井水处理设计中的应用

针对高悬浮物矿井水,设计了5水平6因素的L25(56)正交混凝试验,并通过极差分析确定了混凝的最优化条件,即选择PAC作为混凝剂,pH值调节为9,混凝剂与助凝剂浓度比为20∶1,助凝剂PAM投加滞后30 s,水力条件依次为n=350 r.min-1快速搅拌30 s,n=120 r.min-1中速搅拌4 min,n=60 r.min-1慢速搅拌6 min。通过单因素分析了6种因素对混凝的影响程度,即:PAM投量>混凝剂种类>pH值>混凝剂投量>水力条件>投加时间。依试验结果,对垂向轴式混合反应池进行了参数设计。     

Seasonal Evolution of Dominant Modes in South Pacific SST and Relationship with ENSO

A season-reliant empirical orthogonal function(S-EOF) analysis was applied to the seasonal mean SST anomalies(SSTAs) based on the HadISST1 dataset with linear trend removed at every grid point in the South Pacific(60.5-19.5 S,139.5 E-60.5 W) during the period 1979-2009.The spatiotemporal characteristics of the dominant modes and their relationships with ENSO were analyzed.The results show that there are two seasonally evolving dominant modes of SSTAs in the South Pacific with interannual and interdecadal variations;they account for nearly 40% of the total variance.Although the seasonal evolution of spatial patterns of the first S-EOF mode(S-EOF1) did not show remarkable propagation,it decays with season remarkably.The second S-EOF mode(S-EOF2) showed significant seasonal evolution and intensified with season,with distinct characteristics of eastward propagation of the negative SSTAs in southern New Zealand and positive SSTAs southeast of Australia.Both of these two modes have significant relationships with ENSO.These two modes correspond to the post-ENSO and ENSO turnabout years,respectively.The SEOF1 mode associated with the decay of the eastern Pacific(EP) and the central Pacific(CP) types of ENSO exhibited a more significant relationship with the EP/CP type of El Nin o than that with the EP/CP type of La Nin a.The S-EOF2 mode contacted with the EP type of El Nin o changing into the EP/CP type of La Nin a showed a more significant connection with the EP/CP type of La Nin a.     

两类El Niño事件对中国近海及毗邻海域海表温度的影响

为研究东部型和中部型两类厄尔尼诺(El Ni?o)事件与中国近海海表温度(sea surface temperature,SST)变化间的联系,基于中国科学院大气物理研究所连续80年(1940—2019年)的SST再分析数据,采用EOF分解、合成分析等方法做了初步分析,发现中国近海及毗邻海域近80年SST变化与全球变暖密切相关。并且两类El Ni?o事件对中国近海SST变化的影响存在显著差异。东部型El Ni?o事件发展过程中,中国近海及毗邻海域SST在发展年主要为负异常,衰退期为正异常;中部型ElNi?o事件发展过程中, SST变化区域差异大,发展年日本附近海域为正异常, 28°N以南为弱的负异常。两类El Ni?o事件引发西太平洋风场反气旋涡的时间、位置与强度等的不同,是造成中国近海风场与海表温度异常(sea surface temperature anomaly, SSTA)差异的主要原因。