Structural damage detection method based on information fusion technique

Multi-source information fusion （MSIF） is imported into structural damage diagnosis methods to improve the validity of damage detection. After the introduction of the basic theory, the function model, classifications and mathematical methods of MSIF, a structural damage detection method based on MSIF is presented, which is to fuse two or more damage character vectors from different structural damage diagnosis methods on the character-level. In an experiment of concrete plates, modal information is measured and analyzed. The structural damage detection method based on MSIF is taken to localize cracks of concrete plates and it is proved to be effective. Results of damage detection by the method based on MSIF are compared with those from the modal strain energy method and the flexibility method. Damage, which can hardly be detected by using the single damage identification method, can be diagnosed by the damage detection method based on the character-level MSIF technique. Meanwhile multi-location damage can be identified by the method based on MSIF. This method is sensitive to structural damage and different mathematical methods for MSIF have different preconditions and applicabilities for diversified structures. How to choose mathematical methods for MSIF should be discussed in detail in health monitoring systems of actual structures.

Construction and Development of China’s Earthquake Information Release System

Focused on the current situation,monitoring system,technical management regulation,process,system composition,and information publication of the earthquake information release,we summarized the construction and development of China’s earthquake information release system and expected its future.In general,China’s earthquake information release systems is able to publish auto-results with MS≥3.0 from 1 to 3 minutes,M_S≥6.0 in global from 2 to 30 minutes,and formal results with MS≥3.0 in China from 8 to 30 minutes,MS≥6.0 in global from 20 to 60 minutes.These earthquake information is released by various channels such as short message,website,microblog,mobile application,etc.

Virtual Organization Information Systems and its Reengineering for Agile Manufacturing

It is now possible to organize globally while worki ng locally: Information technologies like e-mail, the Internet, and video confere ncing to the desktop permit tight coordination of geographically dispersed worke rs across time zones and cultures. Companies are not limited to physical locatio ns for providing products and services. Networked information systems are allowi ng companies to coordinate their geographically distributed capabilities as virt ual organizations. In order for organizations to succeed, they must be able to r espond with agility in a geographically dispersed environment. The core for a vi rtual organization to increase the utilization rate of resources to the maxi mum and to make full use of the transient market opportunities lies in how to br ing the potential of information technology into play. Based on the philosophy o f agile manufacturing, this paper analyses the basic concepts and connotation of Virtual Organization Information systems(VOIS). VOIS is an information system composed of some independent information subsystems that are autonomous, collab orative and belong to umpty organizations respectively. VOIS support the operati on of virtual organization, and automate the information flow across organizatio nal boundaries. Such systems have capabilities as rapid construction, quick oper ation, and agile reengineering and swift adaptability. Differences between VOIS and traditional enterprise information systems are analyzed. On the basis of ana lyzing the structure of VOIS, an abstract hierarchical structure of VOIS is prop osed using object-oriented method. Reengineering ideology and methods of VOIS a re also explored in light of the three layers structure.

Information Space and Information Process: Genesis and Evolution

In this article,the phenomenon of“information space”and its methods of study,its types,elementary structure and qualitative characteristics are discussed,the author’s definition of the concept of“information”is given,the structure of the information process,and the phases,which are the basis for the evolution of the information space and the universe of human activity,are considered.

The Study and Development of Plant Management Information System (PMIS) Of NanHua Group Compay

In order to make management scientific, standard and intensive, more and more companies pay attention to plant management. Tlie system presented in this paper aims at helping NanHua Group Co. to improve its plant management level. This paper emphasizes the importance of plant management to NanHua Group Co. and mainly discusses the PMIS and how to implement plant management based on the contents of modern plant management. This part is the core of this paper. The final part sums up the research work and results.

Structural Modal Parameter Recognition and Related Damage Identification Methods under Environmental Excitations: A Review

Modal parameters can accurately characterize the structural dynamic properties and assess the physical state of the structure.Therefore,it is particularly significant to identify the structural modal parameters according to the monitoring data information in the structural health monitoring(SHM)system,so as to provide a scientific basis for structural damage identification and dynamic model modification.In view of this,this paper reviews methods for identifying structural modal parameters under environmental excitation and briefly describes how to identify structural damages based on the derived modal parameters.The paper primarily introduces data-driven modal parameter recognition methods(e.g.,time-domain,frequency-domain,and time-frequency-domain methods,etc.),briefly describes damage identification methods based on the variations of modal parameters(e.g.,natural frequency,modal shapes,and curvature modal shapes,etc.)and modal validation methods(e.g.,Stability Diagram and Modal Assurance Criterion,etc.).The current status of the application of artificial intelligence(AI)methods in the direction of modal parameter recognition and damage identification is further discussed.Based on the pre-vious analysis,the main development trends of structural modal parameter recognition and damage identification methods are given to provide scientific references for the optimized design and functional upgrading of SHM systems.

An unsupervised clustering method for nuclear magnetic resonance transverse relaxation spectrums based on the Gaussian mixture model and its application

To make the quantitative results of nuclear magnetic resonance(NMR) transverse relaxation(T;) spectrums reflect the type and pore structure of reservoir more directly, an unsupervised clustering method was developed to obtain the quantitative pore structure information from the NMR T;spectrums based on the Gaussian mixture model(GMM). Firstly, We conducted the principal component analysis on T;spectrums in order to reduce the dimension data and the dependence of the original variables. Secondly, the dimension-reduced data was fitted using the GMM probability density function, and the model parameters and optimal clustering numbers were obtained according to the expectation-maximization algorithm and the change of the Akaike information criterion. Finally, the T;spectrum features and pore structure types of different clustering groups were analyzed and compared with T;geometric mean and T;arithmetic mean. The effectiveness of the algorithm has been verified by numerical simulation and field NMR logging data. The research shows that the clustering results based on GMM method have good correlations with the shape and distribution of the T;spectrum, pore structure, and petroleum productivity, providing a new means for quantitative identification of pore structure, reservoir grading, and oil and gas productivity evaluation.

信息基础设施对产业结构合理化和高度化影响探析

以5G、6G移动信息设施和宽带固定信息设施为核心的基础设施,对产业结构作用影响机制研究备受重视。通过构建并求解简化的多部门一般均衡模型,从理论层面揭示信息基础设施建设对产业结构的影响机制。其中,信息基础设施的投资量、对产业部门要素生产率的影响程度、对产业部门的资本要素产出弹性等三个因素影响产业结构的合理化;信息基础设施投资在经济社会总产值中的占比,以及与消费和投资产业构成的差异制约着产业结构高度化。在此基础上,利用2009—2022年全国省级面板数据,采用固定效应估计法进一步验证理论和结论。结果表明信息基础设施具有推动产业结构合理化的关键作用,对生产要素在各产业部门之间充分流动、资源有效配置都发挥着积极作用,固定信息基础设施对产业结构合理化的影响略大于移动设施,移动和固定信息基础设施对产业结构高度化的影响作用均不显著,信息基础设施建设和投资通过在产业高附加值化和产业高技术化中发挥的作用还需要进一步加强。

网络信息时代C2组织结构的六维模型

从一般性组织结构的创新思路及指挥与控制(commandandcontrol,C2)方法空间模型出发,以决策权的分配程度、横向协调程度、交互程度、C2单元的规模大小、C2单元的数量及关系影响强度6个维度来描述网络信息时代C2组织结构内中心与边缘C2单元之间的关系。通过构建C2组织结构的六维模型,厘清信息共享在组织横纵向间的共享,决策权在不同层级之中有效赋能与分发,该组织结构在应对网络信息时代下不确定的战时环境时与传统结构相比更具备决胜优势。

The optimal information rate for graph access structures of nine participants

The information rate is an important metric of the performance of a secret-sharing scheme. In this paper we consider 272 non-isomorphic connected graph access structures with nine vertices and eight or nine edges, and either determine or bound the optimal information rate in each case. We obtain exact values for the optimal information rate for 231 cases and present a method that is able to derive information-theoretical upper bounds on the optimal information rate. Moreover, we apply some of the constructions to determine lower bounds on the information rate. Regarding information rate, we conclude with a full listing of the known optimal information rate （or bounds on the optimal information rate） for all 272 graphs access structures of nine participants.

基于传感器感知信息的船舶底面结构变形检测研究

以及时发现船舶底面结构变形,确保船舶在良好状态下运行为目的,研究基于传感器感知信息的船舶底面结构变形检测方法。该方法使用不锈钢封装光纤光栅传感器后,选择8路光纤,在每路光纤上连接若干光纤光栅传感器,然后将8路光纤布设在船舶底面结构上,通过每路光纤上连接的光纤光栅传感器感知船舶底面结构光栅信号,再通过非平衡M-Z干涉法对光纤光栅传感器光栅信号进行解调,得到船舶底面结构应变信息,以其为基础同时结合光纤光栅传感器感知应变状态方程,建立多感知信息融合的变形检测模型,求解该模型后得到船舶底面结构变形检测结果。实验表明:该方法可准确感知船舶底面结构应变信息,且传感器信号零漂波动较小,同时可有效实现船舶底面结构变形检测,应用效果较佳。

面向语义集成——本体在Web信息集成中的研究进展

本体 (Ontology)是描述概念及概念之间关系的概念模型 ,通过概念之间的关系来描述概念的语义。作为一种有效表现概念层次结构和语义的模型 ,本体在Web信息集成中得到广泛的应用。文中就目前本体在Web信息集成中的应用做了分析与探讨 。

基于信息结构要素的信息质量定义与内涵分析

为了评价、控制和提高信息质量,以全信息理论意义下的信息产品为研究对象,分析了信息表达解释的一般过程,提出了信息结构7要素,并据此给出了信息质量的定义和一般公式表示。在此基础上,以企业资源规划信息系统为对象,通过实例分析了由于信息要素缺陷而导致的信息质量问题,并从全信息理论的语法、语义和语用3个不同层次进一步分析了信息质量的内涵。

基于信息多维属性的信息可视化结构

为寻找易于用户认知的信息可视化方法,进行了信息多维属性与可视化结构的映射关系研究.基于复杂网络理论将信息分为3种表现形式,同时将信息的属性归纳为实体属性、关联属性和时间属性.针对信息的属性划分,提出实体属性与可视化图形的映射关系,及关联属性和时间属性与可视化结构的映射关系.通过分析信息所具有的多种关联属性,建立了可视化结构的映射,归纳出信息可视化结构映射的6种基本结构:列表式结构、坐标式结构、空间(地理)位置结构、树状或网状结构、时间流结构、综合结构.最后结合新闻信息可视化实例,阐述了所提出的可视化映射关系和基本结构的应用.

用于JPEG图像的高容量信息隐藏算法

使用JPEG图像的DCT系数作为隐藏载体,通过一种改进的量化嵌入算法提高了信息隐藏的容量.算法以基于结构相似度的图像质量指标作为图像的失真度量,以最速下降法选择嵌入算法中的控制参数,保证了数据嵌入后的图像具有较低的失真水平.实验结果表明本文提出的算法提高了信息隐藏的容量,并较好地平衡了失真和容量之间的关系.

层次结构下的中长期电力负荷变权组合预测方法

提出了一种基于层次结构的中长期电力负荷变权组合预测方法,借鉴层次分析法的思想,构造一个层次结构来确定组合权重:采用熵值法确定模型评价指标的相对权重;采用方差–协方差优选组合预测方法和灰色关联分析分别确定各单一预测模型在各评价指标下的相对权重,最终确定组合预测模型中的组合权重。在组合预测的整个过程中,根据负荷发展的"近大远小"原则,引入等维信息的概念,实现了变权组合预测,使预测结果能够更合理地反映电力负荷的发展规律。最后通过一个实例验证了该方法的有效性。

作物株型和冠层结构信息获取与表述的方法(综述)

系统地介绍了关于作物株型的冠层结构信息获取与表述的方法及有关内容和概念，并比较了各种方法的优缺点。

基于系统工程的信息系统安全体系结构模型研究

随着信息系统的迅猛发展和不断应用,信息安全成为人们研究的重点。文章首先分析了通信安全、计算机安全和信息系统安全的特点及发展过程。从系统工程的角度,提出了信息系统安全三维体系结构模型,从技术维、时间维和管理维对信息系统的安全进行了描述,指出了该三维模型和网络七层协议的关系。该模型对信息系统安全保密研究具有一定的理论指导意义。

基于样本和线性结构信息的大范围图像修复算法

基于纹理的图像修复算法对于修复破损区域比较大的图像效果较好,但该算法对于含有结构信息的图像修复效果很差.通过新的优先项的计算、平均值补偿及增加惩罚项提高传统的基于样本的图像修复算法的修复效果,结合图像中常出现的直线和曲线结构特征,提出了基于样本和结构信息的大范围图像修复算法.实验表明,该算法易于实现,修复结果能达到令人满意的效果,具有较高的实用价值.

不确定结构区间分析的仿射算法

将结构系统中的不确定性参数用区间数表示,建立系统的区间有限元控制方程。对该方程组的求解提出一种基于导数信息的仿射算法。此方法通过令独立的不确定性参数转换成仿射型,将区间线性方程组的求解转化为相应的确定性问题,再搜索各方程解中的最大最小值,得到每个区间分量的边界。先用数学算例对该算法的正确性和有效性进行验证,然后应用于静力区间分析的工程算例,并与其他算法进行比较;计算结果表明该算法的可行性和有效性。