Application of Dempster-Shafer theory in mineral resource potential mapping

The Dempster-Shafer theory has been successfully applied to mineral resource potential mapping in G1S environmental. In this applied form, basic probability assignment and combined basic probability assignment are applied to measuring map pattern and map pattern combination, respectively; and the environment composed of the only two singleton sets (deposit set and non-deposit set), is used for expressing the entire map area. For a subarea in which the certain map pattern combination exists, the combined basic probability assignment corresponding to the map pattern combination existing in this subarea, expresses the belief of inferring the subarea belonging to the deposit set from the evidence that the corresponding map pattern combination existing in the subarea. Thus, it may be served as a statistical index measuring the relative mineral resource potentials of the subarea. And it may be determined like 1) dividing the map area into a series of small equal-sized grid cells and then select the training sample set composed of the well-known grid cells or the entire grid cells; 2) estimating the basic probability assignments corresponding to each map pattern from the training sample set; 3) determining the map pattern combination existing in each cell, and then appling the Dempster's Rule of Combination to integrating the all basic probability assignments corresponding to the map patterns existing in the cell into the combined basic probability assignment. Mineral resource potential mapping with the Dempster-Shafer theory is demonstrated on a case study to select mineral resource targets. The experimental results manifest that the model can be compared with the weights of evidence model in the effectiveness of mineral resource target selection.     

云南天文台大气水汽含量的观测

简述了利用北京师范大学研制的ＩＲＡ－９３５型红外水气测量仪，对凤凰山上空垂直大气水汽积分含量Ｗ０的观测结果及精度。并且给出了Ｗ０的各种变化曲线，在旱季和雨季的Ｗ０分布。同时也给出了红外测水仪测得的数据Ｗ０与无线电探空资料计算得到的数据Ｗ０的比较相关。结果表明：凤凰山上空垂直大气积分水汽含量雨季平均为２．４９６ｃｍ，旱季平均为１．００３ｃｍ；Ｗ０与Ｗ’０的相关系数为０．９４２，测量误差小于５％。     

国外河口水文研究的动向

近十多年来,随着河口水文要素监测技术的现代化,物理和数学模型的不断完善,有力地推进了河口水文学的发展。本文从研究内容和研究方法两个方面对国外河口水文研究的动向进行了分析,着重介绍河口环流、河口锋、河口最大浑浊带研究的进展,并对现场观测、物理模型和数学模型等三种研究方法进行评价,可为发展具有我国特色的河口水文学提供借鉴。     

Application of Dempster-Shafer theory in mineral resource potential mapping

The Dempster-Shafer theory has been successfully applied to mineral resource potential mapping in GIS environmental. In this applied form, basic probability assignment and combined basic probability assignment are applied to measuring map pattem and map pattem combination, respectively; and the environment composed of the only two singleton sets （deposit set and non-deposit set）, is used for expressing the entire map area. For a subarea in which the certain map pattern combination exists, the combined basic probability assignment corresponding to the map pattern combination existing in this subarea, expresses the belief of inferring the subarea belonging to the deposit set from the evidence that the corresponding map pattern combination existing in the subarea. Thus, it may be served as a statistical index measuring the relative mineral resource potentials of the subarea. And it may be determined like 1） dividing the map area into a series of small equal-sized grid cells and then select the training sample set composed of the well-known grid cells or the entire grid cells; 2） estimating the basic probability assignments corresponding to each map pattern fromthe training sample set; 3） determining the map pattern combination existing in each cell, and then appling the Dempster＇s Rule of Combination to integrating the all basic probability assignments corresponding to the map patterns existing in the cell into the combined basic probability assignment. Mineral resource potential mapping with the Dempster-Shafer theory is demonstrated on a case study to select mineral resource targets. The experimental results manifest that the model can be compared with the weights of evidence model in the effectiveness of mineral resource target selection.     

Study on gametophyte vegetative growth ofUndaria pinnatifida and its applications

When cultured under certain environmental conditions (25°C, light intensity 80 μmol/m²·s, LD 12/12, in enriched seawater medium with 7×10⁻⁴ mol/L NO₃−N, 1.56×10⁻⁴ mol/L, PO₄−P and supplements of other elements like Mn, Fe, I, etc.), male and female gametophytes ofU. pinnatifida kept growing vegetatively and propagated fast at average daily fresh weight increase rate of about 20%. The empirical formulaG _m=G _o·3^m was established to estimate the output of vegetative gametophytes. Vigorous vegetative gametophyte cells began to form reproductive structures (oogonium and spermatangium, when the temperature was lower than 25°C and other environmental factors were kept optimal. The sufficient supply of gametophyte cells provided enough seeds for raisingUndaria sporelings on production scale. Controlled cross-breeding experiments using selected male and female gametophyte clones which increase their cell number by mitosis instead of meiosis were also carried out in vitro. Juvenile sporophytes from the cross-breeding had almost the same length and width increase rates as those of the control. The fact that vegetative gametophytes can be purposely selected, propagated quickly, cross-bred, with the resulting sporophytes having almost the same characteristics leads to a new way to select desiredUndaria strains for long time use without losing the desired economic characteristics. Contribution No. 2696 from the Institute of Oceanology, Chinese Academy of Sciences. Supported by National Natural Science Foundation of China.     

Predictor Selection for CNN-based Statistical Downscaling of Monthly Precipitation

Convolutional neural networks(CNNs) have been widely studied and found to obtain favorable results in statistical downscaling to derive high-resolution climate variables from large-scale coarse general circulation models(GCMs).However, there is a lack of research exploring the predictor selection for CNN modeling. This paper presents an effective and efficient greedy elimination algorithm to address this problem. The algorithm has three main steps: predictor importance attribution, predictor rem...     

塔里木盆地轮南油田2、3井区三叠系沉积微相研究

三叠系作为塔里木盆地的主要含油气层系已逐渐被近几年来的油气勘探实践所证实.本文采取综合研究的技术思路和方法,通过取心分析、测井划相,结合开发动态资料,精细刻划各单油砂体在平面及空间上的微相展布.研究表明轮南油田三叠系砂岩,以含砾中粗粒砂岩为主,粒度较粗,重力流沉积特征较突出,以河湖相为主的碎屑岩沉积,其烃源岩主要发育于深湖-半深湖、浅湖和三角洲亚相,从大的韵律到小的层理都显示粒序递变的构造特征,为重力流悬浮搬运沉积的主要标志,存在辫状分支河道微相砂体,分支河道侧缘微相砂体和分支间湾微相砂体三种类型.中上三叠统粗碎屑岩,以及泥岩、粉砂岩,是以半深湖、浅湖至滨岸相环境为主的沉积,自下而上沉积环境分别发育有扇三角洲平原亚相、扇三角洲前缘亚相和前扇三角洲亚相.     

Quality Assessment of an Automatic Sounding Selection Process for Navigational Charts

A good seabed representation is one of the important characteristics of any navigational chart. Along with depth contours and coloured depth areas, soundings are used for this task. All the soundings on a navigational chart are selected for a reason. Soundings contribute to the navigational chart safety aspect by alerting to all the threats and dangers. They also show all the attributes of a seabed relief without overcrowding it, thus maintaining the overall chart quality. Soundings are selected from a hydrographic survey and since it consists of a vast number of data, the process of sounding selection is a challenging and demanding task. It requires experience and knowledge from the nautical cartographer and is mostly done manually. Some types of software nowadays provide an automatic selection feature. This paper analyses a process of automatic sounding selection in the dKart Editor software. On the Croatian side of the Adriatic Sea, ?ibenski Kanal (?ibenik channel) and Kanal Sv. Ante (St. Ante’s channel) are used as the study area. A hydrographic survey of the area represents the input data. The official navigational chart of the surveyed area is used as the basis for determining three different sets of parameters for the selection process. After the selection, obtained results are assessed based on geometrical accuracy and on the conservation level of navigational safety. For geometrical accuracy, the best results were produced by the third set that was divided in two subsets for each channel. It was determined that the nature of the seabed relief had an impact on the selection process. The same set had the best result for navigational safety assessment but it was concluded that all the sets undermined the aspect. Because of these crucial shortcomings noticed in all the tested sets of parameters, the feature is considered inadequate for serious usage as a completely automatic tool for the process of sounding selection on navigational charts.     

单变量特征选择的苏北地区主要农作物遥感识别

遥感识别多源特征综合和特征优选是提高遥感影像分类精度的关键技术。农作物遥感识别中,识别特征的相对单一和数量过多均会导致作物识别精度不理想。随机森林(random forests)采用分类与回归树(CART)算法来生成分类树,结合了bagging和随机选择特征变量的优点,是一种有效的分类方法。单变量特征选择(univariate feature selection)能够对每一个待分类的特征进行测试,衡量该特征和响应变量之间的关系,根据得分舍弃不好的特征,优选得到的特征用于分类。本文基于随机森林和单变量特征选择,利用多时相光谱信息、植被指数信息、纹理信息及波段差值信息,设计多组分类实验方案,对江苏省泗洪县的高分一号(GF-1)和环境一号(HJ-1A)影像进行分类研究,旨在选择最佳的分类方案对实验区主要农作物进行识别和提取。实验结果表明:(1)多源信息综合的农作物分类精度明显高于单一的原始光谱特征分类,说明不同类型特征的引入能改善分类效果;(2)基于单变量特征选择算法的优选特征分类效果最佳,总体精度97.07%,Kappa系数0.96,表明了特征优选在降低维度的同时,也保证了较高的分类精度。随机森林和单变量特征选择结合的方法可以提高遥感影像的分类精度,为农作物的识别和提取研究提供了有效的方法。     

道路网约束下的城市兴趣点选取

针对道路对城市内部兴趣点数据分布有密切的约束关系,故城市内POI数据往往呈现出沿着道路分布的特征这一现象,提出一种在道路网约束下城市内部POI数据的选取算法。通过建立道路网的拓扑结构,根据POI数据的分布位置分为道路周边分布的和远离道路分布的两大类,对道路周边的点使用"间苗法"选取,对远离道路分布的点根据其分布模式决定采用"随机法"或其他方法选取。算法采用实际数据进行实验,切实可行,并得到了合理的结果。