基于最大边缘分配算法的雷达博弈波形设计

实战背景下雷达目标先验信息有较大的不确定性,基于先验信息设计的波形不能满足参数估计的需要。为解决该问题,提出了一种博弈条件下的雷达波形设计方法。考虑到雷达与干扰机在电子对抗中的非同时性,采用Stackelberg博弈框架进行建模。该方法以优化雷达能量谱分布为策略,采用最大互信息准则建立效用函数。博弈过程中,雷达与干扰机各自根据对手策略优化发射波形,经过多次迭代,双方达到纳什均衡。仿真实验对比了均衡策略与maxmin策略与随机策略,证实了所提算法的有效性。     

数据信息化时代下的工程造价管理

在经济不断迅猛发展的形势下,新时代的经济形式催生出一些多元化企业和职业,信息技术的不断发展使数据信息成为最具价值的财富。在信息传播极其迅速的今天,工程造价在数据信息时代下的管理模式也不断更新变化,以适应多元化的工程项目形式。因此信息数据的大量搜集和相关研究受到了各大科研机构和各类企业的高度关注。     

认知闭合需要对农户规范施药行为的影响研究——基于信息加工的中介效应

文章利用辽宁省农户微观调查数据,从认知心理学角度应用结构方程模型分析了认知闭合需要对施药行为的影响机理。研究结果表明:认知闭合需要水平越高,农户施药行为越不规范。具体而言,规则性偏好和确定性偏好程度越高,其施药行为的规范性越低;心理封闭对农户施药行为没有显著影响。同时,认知闭合需要对农户施药行为具有间接影响,且在规则性偏好和确定性偏好对施药行为的间接影响中,信息加工产生了中介效应。     

基于AIC信息准则的Delta T声发射源定位方法

疲劳断裂是金属结构中的主要失效形式,而金属结构中的早期疲劳断裂信号通常难以检测。TOA方法是常用的声发射定位源方法,但是声波传播过程中波速变换和路径的复杂性对其结果影响很大。运用Delta T声发射源定位方法,用断铅实验模拟声发射源,用AIC信息准则对到达时间进行优化,通过使用差值求源点坐标和图像处理的方法,求得声发射源坐标。通过在平板上的实验,比较两种源定位方法在不同结构中的定位结果,分析定位误差,结果表明图像处理方法更为优秀。     

Recovery planning of industrial robots based on semantic information of failures and time-dependent utility

Industrial robots are required to recover from temporary errors and continue operations under a changing environment. In this paper, we propose a recovery planning system that considers the semantic information behind errors during robotic actions. In order to establish general repair strategies for feasible recovery plans under uncertainties, the proposed system uses a conceptual graph based on case grammar and a Bayesian network that is dynamically constructed according to the semantic information. In addition, we tackle the problem that the wealth of the recovery plan depends on the uncertainty of execution costs against the deadline at the production site. The proposed system controls the decision model by using a time-dependent utility. We demonstrate the effectiveness of the proposed system through simulations of assembly tasks by multiple robots.     

基于数据质量评价的目标估计

针对目标估计过程需要大量人工参与、自动化程度低的问题，提出了基于数据质量评价的目标估计方法。利用目标数据质量评价方法，对不同传感器得到的目标数据质量进行科学、有效的测度和评价，并根据质量得分动态调整各数据源在目标估计过程中所占的权重，从而减少人工干预，提高目标估计效能。仿真试验结果证明了该方法的有效性。     

Permeability differences based on three-dimensional geometrical information of void spaces

In this study,the permeabilities of Berea and Otway sandstones were measured under different confining pressures,and porosity was investigated through mercury intrusion porosimetry(MIP).The total porosities of the Berea and Otway sandstones were approximately 17.4%and 25%,respectively.Pore size distributions of each sandstone were almost the same,but the pores in the Otway sandstone were slightly narrower.However,the permeability of the Otway sandstone was smaller than that of the Berea sandstone by one order of magnitude.Three-dimensional(3D)void geometry and geometrical properties of the void spaces relevant to flow were compared to obtain the relation between the permeability differences and porosities of the two sandstones.The 3D geometrical analysis using microfocus X-ray computed tomography(CT)was performed,and the pore geometries of both sandstones were compared using the 3D medial axis(3DMA)method.Pore and throat radii,pore coordination number,tortuosity,number of connecting paths,connecting path volume,and other factors were determined using 3DMA.The Otway sandstone was characterized by a small effective throat/pore radius ratio.Based on the fluid flow mechanism,the lower effective throat/pore radius ratio results in a lower permeability induced by the fluid energy loss,which means that the 3D geometrical shape of void spaces affects the permeability value.     

Feature-based ontological framework for semantic interoperability in product development

An essential requirement in integrating tasks in product development is to have a seamless exchange of product information through the entire product lifecycle. A key challenge in the integration is the exchange of shape semantics in terms of understandable labels and representations. A unified taxonomy is proposed to represent, classify, and extract shape features. This taxonomy is built using the Domain-Independent Form Feature (DIFF) model as the representation of features. All the shape features in a product model are classified under three main classes, namely, volumetric features, deformation features and free-form surface features. Shape feature ontology is developed using the unified taxonomy, which brings the shape features under a single reasoning framework. One-to-many reasoning framework is presented for mapping semantically equivalent information (label and representation) of the feature to be exchanged to target applications, and the reconstruction of the shape model automatically in that target application. An algorithm has been developed to extract the semantics of shape features and construct the model in the target application. The algorithm developed has been tested for shape models taken from literature and test cases are selected based on variations of topology and geometry. Results of exchanging product information are presented and discussed. Finally, the limitations of the proposed method for exchanging product information are explained.     

基于BIM+GIS的大坝安全监测信息可视化展示技术研究

为了解决传统大坝监测信息三维可视化程度低,展示不够直观、形象等问题,采用BIM+GIS技术,将监测信息展示从传统二维空间拓展到三维空间。对BIM建模、模型轻量化、三维可视化展示以及系统功能设计进行了研究,通过在桃源水电站的应用实例表明,BIM+GIS技术能够实现大坝安全监测信息三维可视化展示,展示效果更为形象、生动,具有广泛应用前景。     

Determinants of consumers’ continuance intention to use social recommender systems: A self-regulation perspective

Social recommender systems have transformed how consumers seek product- or service-related information. Based on Bagozzi's self-regulation framework, this study examines the determinants of consumers' continuance intention to use social recommender systems. We found that appraisal factors (perceived information quality and perceived system quality) are strong predictors of emotional reaction (recommendation satisfaction and trust in recommendation). Particularly, perceived information quality has a significant effect on both recommendation satisfaction and trust in recommendation. However, the positive effect of perceived system quality is only on recommendation satisfaction. Both recommendation satisfaction and trust in recommendation positively affect consumers' continuance intention to use social recommender systems.