Automated soil resources mapping based on decision tree and Bayesian predictive modeling

This article presents two approaches for automated building of knowledge bases of soil resources mapping. These methods used decision tree and Bayesian predictive modeling, respectively to generate knowledge from training data. With these methods, building a knowledge base for automated soil mapping is easier than using the conventional knowledge acquisition approach. The knowledge bases built by these two methods were used by the knowledge classifier for soil type classification of the Longyou area, Zhejiang Province, China using TM bi-temporal imageries and GIS data. To evaluate the performance of the resultant knowledge bases, the classification results were compared to existing soil map based on field survey. The accuracy assessment and analysis of the resultant soil maps suggested that the knowledge bases built by these two methods were of good quality for mapping distribution model of soil classes over the study area.

Risk-based water quality decision-making under small data using Bayesian network

A knowledge-based network for Section Yidong Bridge,Dongyang River,one tributary of Qiantang River,Zhejiang Province,China,is established in order to model water quality in areas under small data.Then,based on normal transformation of variables with routine monitoring data and normal assumption of variables without routine monitoring data,a conditional linear Gaussian Bayesian network is constructed.A "two-constraint selection" procedure is proposed to estimate potential parameter values under small data.Among all potential parameter values,the ones that are most probable are selected as the "representatives".Finally,the risks of pollutant concentration exceeding national water quality standards are calculated and pollution reduction decisions for decision-making reference are proposed.The final results show that conditional linear Gaussian Bayesian network and "two-constraint selection" procedure are very useful in evaluating risks when there is limited data and can help managers to make sound decisions under small data.

Role-based Bayesian decision framework for autonomous unmanned systems

In the process of performing a task,autonomous unmanned systems face the problem of scene changing,which requires the ability of real-time decision-making under dynamically changing scenes.Therefore,taking the unmanned system coordinative region control operation as an example,this paper combines knowledge representation with probabilistic decisionmaking and proposes a role-based Bayesian decision model for autonomous unmanned systems that integrates scene cognition and individual preferences.Firstly,according to utility value decision theory,the role-based utility value decision model is proposed to realize task coordination according to the preference of the role that individual is assigned.Then,multi-entity Bayesian network is introduced for situation assessment,by which scenes and their uncertainty related to the operation are semantically described,so that the unmanned systems can conduct situation awareness in a set of scenes with uncertainty.Finally,the effectiveness of the proposed method is verified in a virtual task scenario.This research has important reference value for realizing scene cognition,improving cooperative decision-making ability under dynamic scenes,and achieving swarm level autonomy of unmanned systems.

Research on the self-defence electronic jamming decision-making based on the discrete dynamic Bayesian network

The manner and conditions of running the decision-making system with self-defense electronic jamming are given. After proposing the scenario of applying discrete dynamic Bayesian network to the decision making with self-defense electronic jamming, a decision-making model with self-defense electronic jamming based on the discrete dynamic Bayesian network is established. Then jamming decision inferences by the aid of the algorithm of discrete dynamic Bayesian network are carried on. The simulating result shows that this method is able to synthesize different targets which are not predominant. In this way, various features at the same time, as well as the same feature appearing at different time complement mutually; in addition, the accuracy and reliability of electronic jamming decision making are enhanced significantly.

二值决策Bayesian粗糙集模型属性约简研究

Bayesian粗糙集模型作为经典粗糙集理论与Bayesian推理发展的综合模型,其近似区域划分以事件发生的先验概率为基准,可有效处理众多实际问题,如医疗诊断、故障检测、经济预测等。针对二值决策Bayesian粗糙集理论,证明了Slezak和Ziarko属性约简模型等价,并进一步给出了相应分辨矩阵描述,从而经典粗糙集模型中基于分辨矩阵的知识约简思想均可平移应用于Bayesian粗糙集模型,丰富了Bayesian粗糙集理论体系。

The Design of Predictive Model for the Academic Performance of Students at University Based on Machine Learning

Students in South African Universities come from different socio-cultural backgrounds, countries and high schools. This suggests that these students have different experiences which impact on their levels of grasping information in class as they potentially use different lenses on tuition. The current practice in Universities in contributing to the academic performance of students includes the use of tutors, the use of mobile devices for first year students, use of student assistants and the use of different feedback measures. What is problematic about the current practice is that students are quitting university in high numbers. In this study, knowledge has been drawn from data through the use of machine learning algorithms. Bayesian networks, support vector machines （SVMs） and decision trees algorithms were used individually in this work to construct predictive models for the academic performance of students. The best model was constructed using SVM and it gave a prediction of 72.87% and a prediction cost of 139. The model does predict the performance of students in advance of the year-end examinations outcome. The results suggest that South African Universities must recognize the diversity in student population and thus provide students with better support and equip them with the necessary knowledge that will enable them to tap into their full potential and thus enhance their skills.

Ethical decision-making in older drivers during critical driving situations: An online experiment

The present study examined the impact of aging on ethical decision-making in simulated critical driving scenarios.204 participants from North America,grouped into two age groups(18–30 years and 65 years and above),were asked to decide whether their simulated automated vehicle should stay in or change from the current lane in scenarios mimicking the Trolley Problem.Each participant viewed a video clip rendered by the driving simulator at Old Dominion University and pressed the space-bar if they decided to intervene in the control of the simulated automated vehicle in an online experiment.Bayesian hierarchical models were used to analyze participants’responses,response time,and acceptability of utilitarian ethical decision-making.The results showed significant pedestrian placement,age,and time-to-collision(TTC)effects on participants’ethical decisions.When pedestrians were in the right lane,participants were more likely to switch lanes,indicating a utilitarian approach prioritizing pedestrian safety.Younger participants were more likely to switch lanes in general compared to older participants.The results imply that older drivers can maintain their ability to respond to ethically fraught scenarios with their tendency to switch lanes more frequently than younger counterparts,even when the tasks interacting with an automated driving system.The current findings may inform the development of decision algorithms for intelligent and connected vehicles by considering potential ethical dilemmas faced by human drivers across different age groups.

铁路TFDS故障风险预测的贝叶斯决策模型构建

TFDS是重要的铁路监测设备,但铁路TFDS故障风险因素过多,导致预测精度不高,因此需构建铁路TFDS故障风险预测的贝叶斯决策模型。采用贝叶斯网络结构统计铁路TFDS故障风险发生的概率,根据贝叶斯演绎运算结果与数据相关强度判断故障风险类型,对故障风险数据进行挖掘处理与安全评价,得到铁路TFDS故障预测结果。实验结果表明,该文构建的贝叶斯决策模型的预测精度较高,预测时间短,在铁路TFDS故障风险预测领域具有极高的应用价值。

基于贝叶斯决策的电池模型参数辨识方法

为实现储能电池模组(battery module,BM)等效电路模型参数估计精度和复杂度的平衡,考虑BM内单体电池内阻、容量等参数的不一致,结合串/并联电路基本特性,提出一种基于贝叶斯决策理论的BM等效电路模型辨识方法,通过引入贝叶斯信息准则估计最优模型参数。采用简化建模法、整体建模法和组合建模法在MATLAB/Simulink中搭建两并联两串联的BM等效电路模型,在恒流放电和动态应力测试工况中进行仿真与验证,结果表明,基于三阶RC、多项式函数拟合项数为3的组合建模法具有较高精度,在动态应力测试工况中模型误差不超过1.97%,验证了所提BM模型参数辨识方法的有效性和准确性,为解决多类型储能高精度等效电路模型问题提供有效方法。

基于贝叶斯决策的交互式网络恶意入侵主动防御模型构建

为降低网络的恶意入侵风险,提出基于贝叶斯决策的交互式网络恶意入侵主动防御模型。采用K-聚类算法识别交互式网络中恶意入侵跳频数据,构建交互式网络恶意入侵节点分布模型;采用基于能量熵增量频域互相关系系数的敏感IMF分量选取算法,保留有效的恶意入侵特征分量。利用贝叶斯决策理念,构建恶意入侵防御模型,最终结果显示:该方法的抗干扰系数和冗余度结果分别在0.10和0.22以下;能够准确分类识别交互式网络中恶意入侵跳频数据;特征分量判定精度均在0.946以上;交互式网络的安全系数均在0.936;网络威胁等级均在2级以下,有效提升了网络的安全性。

基于贝叶斯网络的威胁等级评估算法研究

阐述了基于贝叶斯网络专家系统的特点。研究了基于贝叶斯网络的推理模型以及基于此模型的推理算法。利用该算法构建了威胁等级评估模型,并进行了实例计算。研究结果表明,基于贝叶斯网络的威胁等级评估算法是一种有效的评估算法,其结果能够比较准确的反映威胁源的真实威胁程度。

基于贝叶斯决策的自组网推荐信任度修正模型(英文)

在分析了信任评估过程中攻击手段及其相互间关系的基础上,提出了基于贝叶斯决策理论的根据推荐偏差度修正对推荐的信任度方法.使用贝塔分布描述推荐偏差度,依据最小损失原则修正对推荐的信任度,并将具备推荐信任修正机制的信任模型运用在自组网的路由协议中,以便优化路由选择.MATLAB下的仿真结果表明,该方法能够有效抵御一些针对信任管理的威胁并提升信任管理的正确率,进而提高自组网环境下检测恶意节点的效率.

自然风景图像情感标识方法研究

图像情感标识就是为图像标注情感类关键词以反映用户对该图像的情感或印象.以自然风景图像为对象,提出一种由视觉特征提取、视觉-情感关系构建、情感标识推导三部分组成的图像情感标识方案.首先从情感认知角度提取自然风景图像的颜色、纹理等视觉特征,然后采用多维尺度技术挖掘图像视觉特征和人类主观感知之间的深层联系,最后采用贝叶斯决策模型根据图像视觉特征推导出其情感描述.对部分风景图像进行自动标识的结果表明贝叶斯决策模型在处理情感标识这类不确定性推理问题上是很有效的.

基于贝叶斯网络的目标毁伤效果评估研究

随着现代战争节奏的加快,战场环境的复杂化,目标毁伤效果评估(BDA)对战场指挥员的作战决策影响越来越大。而现代战场的复杂性及目标毁伤信息的不确定性,给目标BDA带来了巨大挑战。贝叶斯网络是最近几十年刚流行起来的一种不确定性推理工具,它可以根据不确定或不完整信息对所研究的问题做出相对准确的推理,贝叶斯网络的这种特点正好适合在战场上根据各种不确定或不完整的目标毁伤信息对目标毁伤效果进行综合评估。通过对基于贝叶斯网络的目标BDA方法的探讨,叙述了贝叶斯网络模型的建立与更新过程,并以机场跑道为研究对象,演示了利用贝叶斯网络进行目标BDA的过程,说明了贝叶斯网络在目标BDA中应用的可行性与有效性。

重大传染病疫情演化情境下应急物资配置决策建模分析:以新冠肺炎疫情为例

基于对新冠肺炎疫情时空分布的分析,从时段、关键事件、传播动力学、空间分布、感染规模、信息特征、医疗资源等7个维度构建了重大传染病疫情演化的5种情境,提出了各种情境下需要解决的5个关键应急物资配置决策问题。综合考虑应急物资配置的空间、信息、物资、供应、需求和网络等特性,分析了每一个决策问题进行建模优化的关键因素。基于这些关键因素构建了一个多周期贝叶斯序贯决策模型,给出了求解步骤和解析解,并结合武汉疫情进行了算例分析,验证了模型的有效性。在重大传染病疫情演化情境下,综合考虑这些关键因素,应用贝叶斯决策分析进行应急物资配置决策建模有利于建立更加符合实际的决策模型,减少决策损失。

基于概率图的三支决策模型研究

概率图模型是一类用图形模式表达基于概率关系的模型的总称,用该模型解决损失代价问题已成为当前的研究热点。结合概率图和三支决策理论,提出了基于概率图的三支决策模型。该模型通过对数据进行分析,构造其Bayes网络;并根据模型中节点的相互依赖关系,计算出条件概率分布函数;结合查询变量的先验概率和三支决策损失代价函数,建立了相应的决策规则,给出了概率推理决策中代价最小化问题的一种解决方法。最后通过教学评估实例验证了该模型的有效性。

基于贝叶斯方法的东、黄海鲐资源评估及管理策略风险分析

运用基于贝叶斯的剩余产量模型,对东、黄海鲐资源进行评估,确定了当前鲐资源开发利用状态,估算了在不同收获率水平下未来5年鲐资源量和年总可捕捞量,分析了管理策略实施后鲐资源崩溃的风险。结果表明,2006年东、黄海鲐正遭受过度捕捞,但其资源量并未处于过度捕捞状态。决策分析表明,收获率为0.3是最适预防性的管理策略,在该策略下,鲐平均资源量将从2006年的451千吨将增加到2011年的871千吨,2011年资源量恢复到BMSY的概率为0.48,而过度捕捞的概率为0。

改进的基于统计模型的前景检测方法

针对基于统计模型的前景检测方法进行改进:一方面,背景模型中记录特征向量属于背景的历史最大概率,在当前帧像素点特征向量与背景模型中已有特征向量匹配时,利用历史最大概率提高其更新速度,使其尽快融入背景;另一方面,对利用贝叶斯决策规则检测的前景目标,剔除其轮廓信息后与背景的空间特征进行匹配,减少阴影对前景检测的影响。实验结果表明,与MoG方法和Li的统计模型方法的前景检测相比,该方法在阴影剔除以及大目标物体遮挡背景恢复等方面都有明显改进。

陆军作战指挥实体动态决策建模问题研究

为满足现代战争陆军各级各类指挥所开展方案模拟论证与计划仿真评估的需要,在领域专家经验以及军事规则的支持下,提出了一种基于动态贝叶斯网络的指挥实体动态决策建模方法。通过对动态决策规则的结构化描述,构建了陆战场态势的动态贝叶斯网络模型,基于贝叶斯网络推理模型进行态势相关估计,实现对陆战场的实时变化态势动态分析、理解与判断,可以较好地体现作战系统的复杂自适应的特性,为解决陆军指挥实体动态决策建模问题提供了一种较好的解决办法。

载人六足机器人驾驶决策

为了实现载人六足机器人在复杂地形下的平稳通过,基于载人六足机器人腿部构型建立足端离散化模型,分析其稳定运动空间,确定实时的稳定性评价指标。针对斜坡向平坦地形过渡行走时,提出了基于合作博弈的控制算法,该算法将最优的足端和机体运动序列以指令信息的形式反馈给驾驶员;针对障碍地形行走时,提出了基于贝叶斯决策理论的控制算法,配合足端状态调节机体位置,辅助驾驶员做出最优的决策。根据传感器反馈的信息动态调整运动学裕度和稳定裕度的权重因子,切换两种算法来选取当前地形下的最适控制算法。通过仿真实验结果表明,两种算法有效提高了六足机器人的稳定性,有效减少机体倾斜和足端冲击,提高了操纵效率,为驾驶员的驾驶决策提供辅助。