基于Dempster-Shafer证据理论的匹配区多特征适配性分析方法

匹配区的适配性分析在景象匹配视觉导航中至关重要。目前已有很多匹配区适配性分析特征指标,但都只能片面说明匹配区的适配性。试图将多种特征指标进行综合,解决不同特征指标对适配性分析的冲突性,提出一种特征指标适配置信度和不确定置信度的度量方法,利用Dempster-Shafer (D-S)证据理论对置信度进行融合,得出匹配区适配综合置信度,实验验证了该算法的有效性。     

景象匹配精确制导中匹配概率的一种估计方法

基于景象匹配制导的飞行器飞行前需要进行航迹规划,就是在飞行区域中选择出一些匹配概率高的匹配区,作为相关匹配制导的基准,由此提出了估计匹配区匹配概率的问题.本文模拟飞行中匹配定位的过程定义了匹配概率,并提出了基准图的三个特征参数,最后通过Fisher线性分类器,实现了用特征参数估计匹配概率的目标,并进行了实验验证.     

景象匹配算法研究进展与展望

景象匹配是精确制尊武器精确定位目标的重要方法,景象匹配算法决定了精确制导武器系统的作战性能。论文介绍了景象匹配算法实现的关键要素,详细综述了具有代表性的基于区域、基于特征、基于变换域以及基于模型的四类匹配算法的不同原理、适用性及其改进算法,探讨了景象匹配算法中有待进一步研究的问题和未来发展的方向,为未来的景象匹配制导研究工作提供技术参考和依据。景象匹配制导技术正朝着更稳定可靠、更智能、更快捷、更精确的方向发展,必将推动精确制导武器装备实现现代化和自动化。     

基于BP神经网络的景象匹配算法

针对以可见光图像为基准、红外图像为实测的景象匹配问题,提出了一种基于BP神经网络的景象匹配方法。该方法首先抽取满足平移、旋转、尺度不变性的Krawtchouk不变矩作为红外目标的特征描述并构造特征向量,随后,基于主分量分析法消除特征向量各个分量间的相关性,去掉多个对目标匹配识别贡献不大的特征的影响,形成描述目标的有效特征向量。接下来,构造三层BP神经网络,以有效匹配特征作为输入,匹配位置作为输出,按照经验公式确定隐层节点个数,基于样本集对红外目标在可见光基准图像中的匹配过程进行训练,最终形成智能化景象匹配识别器。实验结果表明,与常用的景象匹配算法相比,提出方法不仅具有更高的匹配精度和速度,而且鲁棒性好,能抵抗实测图像的旋转几何畸变。     

一种基于区域特征的景象匹配算法研究

景象匹配技术是飞行器匹配定位辅助导航系统的核心,如何提高其正确匹配率一直是研究的热点与难点。提出一种基于区域特征的景象匹配算法。首先,提取基准景象和实时景象的稳定极值区域,并计算出区域的灰度、形状、纹理以及起伏程度特性作为相似性度量的主要因素构造相似性度量函数;然后,计算区域对的Hausdorff距离,决定是否是对应区域。大量的模拟实验表明,该算法的匹配时间能达到0.138 s,正确匹配率达到92.67%,不仅能满足景象匹配的要求,且大大提高了匹配的时间与正确率,对导航系统的定位具有实用价值。     

一种基于小波分析的景象匹配算法研究

对于一些领域的景象匹配,传统的匹配算法已经无法满足要求.提出了一种基于小波分析分层搜索的景象匹配方法,它采用由粗到细的分层匹配方法,在每个层上采用不同的方法,并基于MATLAB实验平台对方法进行了仿真实验并与传统的匹配算法进行了比较.结果表明基于小波分析分层搜索的景象匹配方法较传统的匹配方法无论在速度上还是在精度上都具有明显的优势.提出的算法可以有效地改善传统匹配算法中的不足之处,在景象匹配领域,具有一定的可行性.     

N帧连续景象匹配一致性决策算法

下视景象匹配是各类巡航飞行器实现精确导航的重要手段,它是通过事先装载在飞行器的地面基准图像与实时获取的地面景象图进行相关匹配,完成飞行器的飞行误差修正和精确定位,由于基准图和实时图在获取手段、时间上等方面的差异,在相关匹配中,配准点往往落在相关阵的次峰上,导致匹配失败,该文提出了多帧连续景象匹配,利用单次匹配后形成的相关阵中的主次峰信息与导航信息进行一致性决策的图论算法,由于引入了相关阵中的次峰信息,并结合惯导位移进行一致性判断,使得匹配算法能有效剔除误匹配点,从而提高了算法的匹配概率和鲁棒性。     

景象匹配算法及其适应性分析

提出一种基于区域特征的景象匹配算法。其基本方法是先提取基准图和实时图的稳定极值区域,并计算出区域的平均灰度、方差、仿射不变矩以及纹理信息熵,构造相似性度量函数,然后计算匹配区域对的Hausdorff距离决定是否是对应区域。大量的模拟实验表明,该算法的匹配时间能达到0.138 s,正确匹配率达到92.67%,不仅能满足景象匹配的要求,且大大提高了匹配的时间与正确率。对其适应性进行了详细的分析,结果表明该算法对旋转、尺度、噪声、灰度变化的适应性较好。     

快速并行两级景象匹配方法

文章分析了景象匹配系统的性能评价以及影响性能评价的三个主要因素,即实时图大小,参考图大小和匹配算法。分析了实时图大小的选取对匹配时间,匹配率的影响。并且针对巡航导弹的景象匹配制导系统的实时性问题,提出了一种快速并行两级景象匹配方法。该方法能够极大地提高匹配效率。试验中利用SAR图像和可见光图像进行景象匹配,每次匹配的时间从原来的约16秒减少到300毫秒左右,匹配率可达到90%以上。而且还具有可扩充性好的特点。     

结合区域全局特征和Ann-SIFT的二阶段快速景象匹配算法

在GPS拒止环境下，提出了一种基于高清航拍图像的视觉定位方法。为了保证高分辨率图像匹配的实时性，结合粗粒度高级语义全局特征和细粒度点特征实现两阶段快速景象匹配。第一阶段，设计三元组网络针对图像区域提取具有尺度和旋转不变性的全局描述符进行区域预匹配。第二阶段，快速最近邻点搜索的Ann-SIFT对实时图和参考区域进行精确点匹配以实现定位。对于3 000×3 000的参考图像和500×500到1 000×1 000尺寸范围的实时图像，平均耗时可以从66.24 s降低到0.97 s。     

Knowledge acquisition and integration tools aiming to support managerial planning in Greek SMEs

Most existing expert systems are defined in structured task domains. However, many real-life decision tasks are novel, unstructured and consequential. To support these tasks, expert systems are needed which provide an integrated environment capable of capturing new knowledge by updating the existing knowledge base. This paper describes the incremental development process of an expert system, from the initial gathering of data up to the development of knowledge acquisition tools and knowledge integration methodologies. The expert system developed addresses managerial planning tasks of Greek small-to-medium sized enterprises (SMEs). The manager sets values for parameters specifying environmental and company characteristics. The expert system responds with suggestions on feasible tactics, objectives and strategies. To cope with the changes of planning situations and also to improve the integrity of the knowledge base as the manager gains experience, knowledge acquisition tools have been introduced. These knowledge acquisition tools, which are manipulated directly by the manager, provide the system with additional knowledge and validate the knowledge already embedded in the knowledge base.     

Eliciting knowledge and transferring it effectively to aknowledge-based system

The knowledge acquisition bottleneck impeding the development of expert systems is being alleviated by the development of computer-based knowledge acquisition tools. These work directly with experts to elicit knowledge, and structure it appropriately to operate as a decision support tool within an expert system. However, the elicitation of expert knowledge and its effective transfer to a useful knowledge-based system is complex and involves diverse activities. The complete development of a decision support system using knowledge acquisition tools is illustrated. The example is simple enough to be completely analyzed but exhibits enough real-world characteristics to give significant insights into the processes and problems of knowledge engineering     

D-KAT: a deep knowledge acquisition tool

Abstract: This paper describes a system of shallow and deep knowledge acquisition and representation for diagnostic expert systems. The acquisition system is integrated into a diagnostic expert system shell. Shallow knowledge is represented in a failure model as a set of cause-effect relations among the possible faults, while deep knowledge is represented in three deep models: a functional, a deep causal and a taxonomic model. The acquisition and the representation of all the models are fully integrated. The deep knowledge is used by the final expert system in order to provide the user with deep explanations of the cause-effect relations of the failure model.     

一种集成定性定量的决策方法在水、火联合电力系统长期调度中的应用

以水、火联合电力系统长期调度问题为背景，探讨了一个基于分解协调算法的集成定性定量决策系统的设计和应用。其中约束自调整方法构成了定性决策算法的核心。对华中电网的试算证明，该系统的决策支持性能好，具有柔性。由于实现了专家知识与算法的有机集成，因而能满足各种实际要求，可操作性强。     

基于可拓方法的智能策略生成器的研究

提出了解决矛盾问题的智能型集成化可拓策略生成器的设计思路和总体结构框架。系统设计基于综合集成方法的基本思想,遵循信息组织和可拓决策知识的特点,将物元分析法、专家系统、决策支持系统、神经网络有机地组织集成起来,从而快速、灵活地为决策者提供从知识获取、判断推理到创造性思维、策略生成的智能决策支持环境。     

基于决策树的网络故障诊断专家系统模型

针对传统网络故障诊断专家系统在知识获取方面的固有不足,结合决策树算法和专家系统的特点,提出一种基于决策树的网络故障诊断专家系统模型,讨论网络故障诊断专家系统模型的推理机制和推测算法以及知识获取的实现方法。实践结果表明,模型在知识获取方面具有获取过程简单、计算复杂性低、适应性强的特点。     

The Knowledge Acquisition Bottleneck: Time for Reassessment?

Abstract: Knowledge acquisition has long been considered to be the major constraint in the development of expert systems. Conventional wisdom also maintains that the major problem encountered in knowledge acquisition is in identifying the varying structures and characteristics of domain knowledge and matching these to suitable acquisition techniques. With the aid of the first substantial systematic analysis of a sample of expert systems applications developed in the real world, the authors describe what is actually going on in terms of knowledge acquisition. In the light of the evidence, it is argued that a reappraisal of the conventional approach to knowledge acquisition is necessary.     

Selection of sheet metal bending machines by the PRISM-inductive learning method

In this paper, a selection system of sheet metal bending machines is established. Machine specifications such as pressure capacity and bending length have to be considered in the selection in order to reach the best choice according to the need of the decision maker. The purpose of this paper is to utilize the PRISM method of inductive learning and knowledge acquisition to construct a product-type rule base, and further complete an expert system for the selection of sheet metal bending machines, which may assist the user in choosing the appropriate bending machine.     

A decision-making module for aiding ship system automation design: A knowledge-based approach

The use of elements of artificial intelligence, including knowledge-based systems, becomes more and more widespread in aiding design problem solutions. The authors have been working on problems of control systems for many years. A design process involves many decision problems connected with, for example, a choice of a subsystem structure, subunits or particular elements selection. Because of such regards, it was decided to extend knowledge-based system with a module for support of such decision making.In this paper, an elaborated module for decision-making support is considered. The basic theoretical assumptions concerning the accepted method of multiattribute decision making based on pairwise comparison in categories of hierarchical decision process (AHP) is presented. Accepted knowledge representation in AHP method and pairwise comparison method and methods of expert knowledge acquisition are discussed. The module functioning is illustrated by an example of choice of temperature sensors in a system of fuel transport to Diesel engine of a main propulsion unit of a ship.     

Computer-Assisted Diagnosis of Postmenopausal Osteoporosis Using a Fuzzy Expert System Shell

This paper shows how the AMDIS (Automated Medical Diagnosis with Intelligent Systems) integrated system can be employed to build a fuzzy medical expert system in the domain of postmenopausal osteoporosis, The fundamental aims of the expert system are to standardize knowledge and support physicians in the early detection of postmenopausal osteoporosis. A wide range of diagnostic situations has been considered for both categories of the disease, with judgments that range from disease is excluded to disease is definite. The salient aspects of the approach are the use of fuzzy logic as an analytic language for the representation and manipulation of knowledge and strategies and the integration of structured interview techniques and learning-by-example to address the knowledge acquisition task.