禁忌搜索算法在图像匹配中的应用研究

搜索策略是图像匹配研究的主要问题之一,对匹配算法的执行速度和最终的匹配精度都有很大的影响。该文将禁忌搜索算法的思想用于图像匹配的搜索过程,并进行了改进,构造了永久禁忌和暂时禁忌两种禁忌表,每次搜索都将候选解中的点分别放入不同的禁忌表中,再利用基于灰度的匹配方法,以归一化积相关为相似性度量准则,克服了传统的归一化积相关图像匹配算法耗时过长的缺点,可以在不失匹配精度的条件下,大大减少匹配所用的时间,实现了准确而快速的图像匹配。     

Inversion of potential field data

The problem of inversion of potential field data is a challenging one because of the difficulty in obtaining a unique solution. This paper identifies various types of nonuniqueness and argues that it is neither possible nor necessary to remove all categories of nonuniqueness. Some types of nonuniqueness are due to human limitations and choice and these would always persist. Listing all the solutions, imposing additional constraints on the acceptable solutions, a priori idealization, use of a priori or supplementary information, characterizing what is common to all the solutions, obtaining extremal solutions, seeking a distribution of all possible solutions, etc. are various responses in the face of nonuniqueness. It is shown that merely the form of nonuniqueness is changed by all these techniques. Some algorithms, which should be used to obtain the global minimum of the objective function are discussed. The conceptual commonality underlying seemingly different approaches and the possibility of nonunique interpretations of the same numerical results due to different axiomatic contexts are both elucidated.     

Requirements for the performance of a ground-penetrating radar system in searching for cavities

The requirements for the performance of a ground-penetrating radar (GPR) system for detecting subsurface cavities are analyzed by numerical modeling of the GPR problem. The algorithm used to solve the forward GPR problem is approximated to a real experiment with regard to the design of the GPR system, the parameters of the source and receiver, and their position relative to the medium under study and its inhomogeneity. We calculated the spatiotemporal distribution of the field of the detected signal from a pulse source located at the interface between the medium and a cavity anomaly of a given geometry. The results were used to estimate the dynamic range of the GPR system necessary for determining the anomaly. We also performed GPR surveys of low-contrast inhomogeneities (cavities in mines) using GROT 12 GPR systems and analyzed the survey results by numerical modeling. It is shown that the GPR performance required to detect and locate inhomogeneities of interest at a certain sounding depth can be estimated in the experiment design phase.     

基于KRR优化算法的油水系统中CO2溶解度模型

油藏中注入CO2可形成CO2原油地层水三相动态平衡,CO2在油水系统中的溶解度将直接影响CO2驱油效果和封存潜力。为了对CO2在油水系统中的溶解度模型进行研究,以吉林油田某油水系统为例,利用高温高压PVT分析仪开展CO2在不同体积比例油水系统中的溶解度实验,明确了CO2在油水系统中的溶解规律,并基于实验数据,分别利用网格搜索法(GS)和贝叶斯优化算法(BOA)对核岭回归算法(KRR)的参数进行优化,建立了CO2在油水系统中的溶解度预测模型。研究结果表明：CO2在油水系统中的溶解度随CO2注入量的增加而增大,也随油水体积比升高而增大;基于KRR算法的优化模型中,GSKRR模型和BOAKRR模型平均相对误差分别为6.758%和1.998%,说明BOAKRR具有更高的预测精度。利用BOAKRR模型预测并绘制不同温度、不同油水体积比下的CO2在油水系统中的溶解度图版,可为CO2碳捕集、利用与封存（CCUS）技术的应用提供支持。     

中国钾盐地质资源现状与找钾方向初步分析

分析了中国钾资源供需形势、有利成盐找钾时代、主要的有利成钾盆地等,回顾了中国找钾工作的历史,指出中国西部仍有找钾前景,尤其是中、上侏罗统-白垩系和新生界,其次是上震旦统-寒武系、石炭系、奥陶系和三叠系,同时,还应继续开展现代盐湖和地下卤水找钾和综合评价,主要找钾地区为塔里木盆地、滇西-羌塘盆地、柴达木盆地和上扬子盆地。鉴于中国特定的成盐构造地质条件和钾盐成矿、保存特点,以及国外预测找钾的经验,在中国找钾要有做长期深入勘查研究的思想准备和采取切实有效的措施,建议对找钾工作加大投入,加强找钾预测的地质基础研究,建立专业队伍和落实油钾兼探的方针。     

化探在找油气中的作用

本文侧重以实例阐述化探在我国找油气中的作用,这些作用包括预测盆地的含油气远景、指出油气富集的有利区带、评价圈闭或区块的含油气性,圈定油气田有效范围和随钻油气层预测与评价。     

基于网格搜索法优化支持向量机的围岩稳定性分类模型

为科学评价围岩稳定性,本次研究借助支持向量机(SVM)处理小样本、非线性问题能力强的特性,对围岩的稳定性进行了分类。选取16组围岩数据作为学习样本,以岩石质量指标、岩石单轴饱和抗压强度、完整性系数、结构面强度系数和地下水渗水量5个指标作为模型输入,围岩稳定程度为模型输出,建立了基于支持向量机的围岩稳定性分类模型。为增强模型的推广性能,提高其预测准确率,运用改进的网格搜索方法(GSM)寻找最优的支持向量机参数,并对8组围岩数据进行预测,并同BP神经网络模型的预测结果进行对比。结果表明,建立的GSM-SVM模型对预测样本的评判结果与实际结果一致,其预测精度较BP神经网络有很大的提升。     

Automated statistical matching of multiple tephra records exemplified using five long maar sequences younger than 75 ka,Auckland, New Zealand

Detailed tephrochronologies are built to underpin probabilistic volcanic hazard forecasting, and to understand the dynamics and history of diverse geomorphic, climatic, soil-forming and environmental processes. Complicating factors include highly variable tephra distribution over time; difficulty in correlating tephras from site to site based on physical and chemical properties; and uncertain age determinations. Multiple sites permit construction of more accurate composite tephra records, but correctly merging individual site records by recognizing common events and site-specific gaps is complex. We present an automated procedure for matching tephra sequences between multiple deposition sites using stochastic local optimization techniques. If individual tephra age determinations are not significantly different between sites, they are matched and a more precise age is assigned. Known stratigraphy and mineralogical or geochemical compositions are used to constrain tephra matches. We apply this method to match tephra records from five long sediment cores (≤ 75 cal ka BP) in Auckland, New Zealand. Sediments at these sites preserve basaltic tephras from local eruptions of the Auckland Volcanic Field as well as distal rhyolitic and andesitic tephras from Okataina, Taupo, Egmont, Tongariro, and Tuhua (Mayor Island) volcanic centers. The new correlated record compiled is statistically more likely than previously published arrangements from this area.     

基于知识图谱的岩溶知识发现系统建设

岩溶领域通过地质调查和科学研究积累了大量的成果资源,资源之间的关联关系更加复杂,传统的关键词检索模式已不满足用户获取知识的需求。为实现知识层面的数据检索,利用数据挖掘技术进行岩溶实体抽取与关系计算,以岩溶术语为核心,基于知识图谱构建岩溶知识发现系统,实现岩溶地质成果、期刊、论文、图书、标准、项目、专家等实体的智能语义搜索和关联导航,最大化的挖掘数据的潜在价值,为用户提供精准知识服务,提升了用户体验。     

A mixed continuous and discrete nonlinear constrained algorithm for optimizing ship hull structural design

A nonlinear search algorithm for optimizing constrained design of ship structures is presented. The decision variables can be continuous or discrete and the constraints can be homogeneous or inequality nonlinear functions of those variables. The algorithm does not use gradients; therefore, it can work with non-systematized functions such as tables or another class of design routine. It was tested in the structural design of a Patrol Boat and has proved to be a powerful tool decreasing the time expended in preliminary design when it is done by the conventional spiral approach.