一种特殊的后方交会法

本文对特殊的后方交会法的布点、观测、解算作了一般性的介绍，重点讨论了放样允许误差区域的确定．     

基于决策规则的遥感影像土地利用信息提取

遥感作为近几十年迅速发展起来的一门综合性技术学科,己经在许多领域发挥了重大作用。通过对遥感数据进行专题分类处理以得到土地利用等专题信息是遥感最广泛的应用领域之一。尽管土地利用遥感分类方法不断发展,但分类技术始终跟不上遥感技术本身的发展。本论文的主要目标之一就是以沈阳矿区为研究区,利用多源遥感数据结合地面实地调查,围绕遥感图像,采用常规的最大似然分类法,同时采用选用决策树分类方法,对不同数据源得到的信息进行综合分析,充分利用其中的光谱信息、地学知识以及人的经验知识进行土地利用分类,从而更好地为地方土地有效利用提供决策依据。     

CFG桩复合地基极限承载力计算模型及其验证

CFG桩因具有良好的经济性和适用性,工程中得到了越来越广泛地应用,传统的分析方法主要通过桩土承载力迭加获取,与实际施工监测结果误差比较大。在分析了CFG桩复合地基的竖向承载力特性基础上,依据CFG桩复合地基的等沉面上下部分的不同特征,提出了CFG桩复合地基的“双剪切破坏模型”：等沉面以上部分看作太沙基模型的桩体的向上剪切破坏,等层面以下部分看作迈耶霍夫模型的桩体向下的剪切破坏,推导了极限承载力的有关计算模型,讨论了该模型适用条件,并结合工程实例,验证了所提模型的正确性,对CFG桩复合地基工程有一定的指导意义。     

Regional Probabilistic and Statistical Mineral Potential Mapping of Gold–Silver Deposits Using GIS in the Gangreung Area, Korea

The aim of the present study is to analyze relationships between epithermal Au‐Ag deposits of the hydrothermal type and related geological factors and integrate the relationships using probabilistic and statistical models in a geographic information system (GIS) environment. A variety of spatial geological data were compiled, evaluated and integrated to produce a map of potential Au and Ag deposits in the Gangreung area, Korea. This empirical approach assumes that all deposits shared a common genesis. The method consists of three main steps: (i) identification of spatial relationships; (ii) quantification of such relationships and (iii) integration of multiple quantified relationships. A spatial database containing Au and Ag deposits, topographic, geologic, geophysical and geochemical data was constructed using a GIS. The factors relating to 103 Au and Ag mineral deposits are the geological data such as lithology and fault structure, geochemical data including the abundance of Al, As, Ba, Ca, Cd, Co, conductivity, Cr, Cu, Eh, Fe, HCO3–, K, Li, Mg, Mn, Mo, Na, Ni, Pb, pH, Si, Sr, V, W, Zn, Cl^?, F^?, PO₄^3?, NO₂^?, NO₃^? and SO₄^2?, and geophysical data including Bouguer and magnetic anomalies. Using the constructed spatial database, the relationships between mineral deposit areas and 36 related factors are identified and quantified by probabilistic and statistical modeling; that is, likelihood ratio, weights of evidence and logistic regression. All the factors were combined to produce a map of the regional mineral potential using the overlay method in a GIS environment. The mineral potential map was then verified by comparison with known mineral deposits. The verification results give respective accuracies of 82.52%, 72.45% and 81.60% for the likelihood ratio, weights of evidence and logistic regression models, respectively. The mineral potential map can be used as a source of basic information for mineral resource development.     

Least-squares variance component estimation

Least-squares variance component estimation (LS-VCE) is a simple, flexible and attractive method for the estimation of unknown variance and covariance components. LS-VCE is simple because it is based on the well-known principle of LS; it is flexible because it works with a user-defined weight matrix; and it is attractive because it allows one to directly apply the existing body of knowledge of LS theory. In this contribution, we present the LS-VCE method for different scenarios and explore its various properties. The method is described for three classes of weight matrices: a general weight matrix, a weight matrix from the unit weight matrix class; and a weight matrix derived from the class of elliptically contoured distributions. We also compare the LS-VCE method with some of the existing VCE methods. Some of them are shown to be special cases of LS-VCE. We also show how the existing body of knowledge of LS theory can be used to one’s advantage for studying various aspects of VCE, such as the precision and estimability of VCE, the use of a-priori variance component information, and the problem of nonlinear VCE. Finally, we show how the mean and the variance of the fixed effect estimator of the linear model are affected by the results of LS-VCE. Various examples are given to illustrate the theory.     

Markov random field-based method for super-resolution mapping of forest encroachment from remotely sensed ASTER image

Forest encroachment (FE) is a problem in Andaman and Nicobar Islands (ANI) in India for environment and planning. Small gaps created in the forest slowly expand its periphery disturbing the biodiversity. Therefore, intrusion of poachers, slash and burn and other factors causing FE must be carefully detected and monitored. Remote sensing offers a great opportunity to accomplish this task because of its synoptic view. Conventional classification methods with remotely sensed images are problematic because of small size of FE and mixed landcover composition. This study presents an application of super-resolution mapping (SRM) based on Markov random field for detection of FE using ASTER (15 m) images. The SRM results were validated using multispectral IRS LISS-IV (5.8 m) image. Non-contiguous FE patches of various sizes and shapes are characterized using the spatial contextual information. The novelty of this approach lies in the identification and separability of small FE pockets which could not be achieved with pixel-based maximum likelihood classifier (MLC). The SRM parameters were optimized and found comparable to previous studies. Classification accuracy obtained with SRM at scale factor 3 is κ = 0.62 that is superior to accuracy of MLC (κ = 0.51). SRM is a promising tool for detection and monitoring of FE at Rutland Island in ANI, India.     

Cosmo-SkyMed X-band SAR data for classification of ice-free areas and glacier facies on Potter Peninsula,King George Island Antarctica

The climate change phenomena have been influencing terrestrial and glacial ecosystems around the planet. Maritime Antarctica is especially sensitive to these climate variations and over the last 50 years increasing global air temperatures have caused extensive glacial retreat. The objective of this study is to evaluate the potential use of the SAR technology in monitoring the surface dynamics of the Potter Peninsula, King George Island, maritime Antarctica. An image generated by the SAR satellite COSMO-SkyMed, obtained on 2 February 2011, was used to extract the backscattering values of targets on the surface for further processing and classification, using a supervised statistic classifier of maximum likelihood for the determination of the surface classes. The average backscattering of water bodies presented high similarity, which made its separation unattainable. On the other hand, the surface classes’ bare ice and wet snow over the glacier presented distinct average backscattering values, which allowed an efficient and precise classification using only this parameter. The classification process showed satisfactory results for periglacial environments, presenting high fidelity to the field data.     

室内定位多传感器的空间配准

针对卫星信号到达地面时较弱、不能穿透建筑物的问题,该文对无法使用卫星定位时的辅助手段之一——室内定位技术作了研究。室内定位多传感器信息融合需要在统一坐标框架下进行,传统的空间配准解决方案多为简单的"松组合"加工。该文给出了多传感器空间配准数学模型,通过构造极大似然函数估计传感器间的位置偏差,采用粗估计与高斯牛顿迭代估计的两步法求解,并用仿真算例验证了该文所采用算法的有效性与正确性。     

因子交配设计中文蛤亲本数目对遗传参数估计的影响

The precise and accurate knowledge of genetic parameters is a prerequisite for making efficient selection strategies in breeding programs.A number of estimators of heritability about important economic traits in many marine mollusks are available in the literature,however very few research have evaluated about the accuracy of genetic parameters estimated with different family structures.Thus,in the present study,the effect of parent sample size for estimating the precision of genetic parameters of four growth traits in clam M.meretrix by factorial designs were analyzed through restricted maximum likelihood(REML) and Bayesian.The results showed that the average estimated heritabilities of growth traits obtained from REML were 0.23–0.32 for 9 and 16 full-sib families and 0.19–0.22 for 25 full-sib families.When using Bayesian inference,the average estimated heritabilities were0.11–0.12 for 9 and 16 full-sib families and 0.13–0.16 for 25 full-sib families.Compared with REML,Bayesian got lower heritabilities,but still remained at a medium level.When the number of parents increased from 6 to 10,the estimated heritabilities were more closed to 0.20 in REML and 0.12 in Bayesian inference.Genetic correlations among traits were positive and high and had no significant difference between different sizes of designs.The accuracies of estimated breeding values from the 9 and 16 families were less precise than those from 25 families.Our results provide a basic genetic evaluation for growth traits and should be useful for the design and operation of a practical selective breeding program in the clam M.meretrix.     

IMPROVED MAN-COMPUTER INTERACTIVE CLASSIFICATION OF CLOUDS BASED ON BISPECTRAL SATELLITE IMAGERY

In this paper,improvement on man-computer interactive classification of clouds based onhispeetral satellite imagery has been synthesized by using the maximum likelihood automaticclustering(MLAC)and the unit feature space classification(UFSC)approaches.The improvedclassification not only shortens the time of sample-training in UFSC method,but also eliminatesthe inevitable shortcomings of the MLAC method.(e.g.,1.sample selecting and training isconfined only to one cloud image:2.the result of clustering is pretty sensitive to the selection ofinitial cluster center:3.the actual classification basically can not satisfy the supposition of normaldistribution required by MLAC method;4.errors in classification are difficult to be modified.)Moreover,it makes full use of the professionals'accumulated knowledge and experience of visualcloud classifications and the cloud report of ground observation,having ensured both the higheraccuracy of classification and its wide application as well.