Damage Assessment of Frame StructuresBased on Neural Network

Based on neural network,this paper presents a method of damage assessment of frame structures,which provides a new approach for damage assessment of structures under dynamic conditions.The adaptability and efficiency of this method are discussed through computation simulation,The numerical results show that this method is promising.     

Fuzzy Assessment Method for Seismic Damage of CFST Arch Bridges

In order to investigate the conditions of damage and failure of concrete-filled steel tube(CFST) arch bridges, considering the structural and mechanical characteristics of CFST arch bridges, the dual damage criteria assessment models of the various components based on deformation or strength and energy were developed. The nonlinear seismic response of CFST arch bridges was analyzed by finite element method and the fuzzy evaluation method of seismic damage based on fuzzy theory and analytic hierarchy process was studied. Finally, taking a long-span CFST arch bridge as example, the damage index of the bridge was 0.150, 0.152, 0.172 and 0.318 respectively when the seismic peak acceleration was respectively 0.1g, 0.2g, 0.4g and 0.8g. The results show that the CFST arch bridge is slightly damaged under the earthquake when the seismic peak acceleration is 0.4g, and the bridge is damaged moderately when the peak acceleration is 0.8g.     

Quantitative analysis of damage extent of transmission tower by using strain energy method

In order to solve the structural damage identification problem of transmission tower, a two-step identification method based on change rate and dissipation rate of modal strain energy is proposed. The damage location is identified by the change rate of modal strain energy method. Then, the modal strain energy dissipation rate theory is analyzed further by using the element stiffness matrix after injury. As a result, a more accurate damage quantification equation method is introduced. This method requires only several modals of vibration. The numerical simulation results show that this two-step method can find the damage location and damage degree of transmission towers effectively.     

A Numerical Study on the Damage Assessment of a Simply-supported Beam on Natural Frequencies

Based on the perturbation theory, it was proved that the ratio of changes of frequencies is the function of structural damage location. Taking a uniform cross-sectioned simply supported beam for example, the ratio of changes of frequencies between the damaged and intact beam was used to locate and qualify beam damage. For different extents of damage, the changes of frequencies and ratio of changes of frequencies were studied and the effects resulted from the omission of second order items were discussed. Finally, the deficiency of this method was pointed out.     

Synthetic Assessment of Power Transformer Condition Based on Matter-element Theory

Condition assessment on power transformer is an important approach to improve reliability of transformer and provide proper decision-making for condition-based maintenance. For long, static assessment method used in the past has already not adapted to the development of modem electricity transmission and distribution technology. So based on the deficiency of fuzzy synthetic assessment method, matter-element synthetic assessment method is introduced. The method can evaluate transformer condition not only in quality but also in quantity. Because each index weight can be given fairly and fast through improved analytic hierarchy process, which need not carry on consistency chec accuracy of assessment can be improved. Examples analysis has proved that assessment method of power transformer condition based on matter-element theory is rational and effective.     

Stability assessment method for small and medium potential landslides and results analysis

Small and medium landslides are widely distributed, the prediction mainly relies on the monitoring and controlling systems executed by the masses. The advantages and disadvantages of various stability assessment methods are compared. The engineering analogy method accords with the requirements for small and medium landslide assessment. A method is illustrated based on Fisher discrimiant function to cope with the small and medium potential landslide stability assessment. The impact factors of landslides is explored with the historical data. The stability is taken as a multi-dimensional statistical variable and project into one-dimensional straight line. Distance discriminant method is used to construct a classification criterion. The applicability of this method is explored, and assessed the landslides in Chongqing Wulong by this method. The results show that accuracy of this method is about eighty percent. This method is suitable for the city of Chongqing or other areas with the similar geological environment.     

Three-dimensional Random Damage Prediction Model of Concrete Caused by Freeze-thaw

In order to effectively assess the damage of concrete in freeze-thaw condition, prediction model for concrete frost damage is presented based on damage mechanical theory and the experimental test. The degeneration of tension strength of air-entraining concrete is tested after freezing and thawing. Provided with the fact that the degeneration of concrete is an interior damage evolving process, freezing and thawing damage accumulation of concrete is analyzed based on the discrete grid with probability of stochastic method. And Three-dimensional multi-parameters Weibull distribution model about concrete damage evolutions is presented. Parameters are estimated based on gradient method, and the mathematical model is verified according to the tested data. Corresponding algorithm is designed and programming is completed by C + + programming language to establish concrete durability prediction model under freeze-thaw conditions. It is indicated that the damage of concrete develops in nonlinear way as the freezing and thawing increases.     

基于GIS的洪灾损失评估方法

洪灾损失评估是防洪减灾领域的一项基础性工作。笔者在国内外洪灾损失评估信息系统研究的基础上，对现有的洪灾损失评估方法进行了探讨，论述了GIS技术在洪灾损失评估中的应用、特点及作用等，并提出了洪灾损失评估有待解决的问题及未来发展趋势，为科学、有效的采取防洪减灾措施提供一定的参考依据。     

Progressive Collapse Analysis of RC Frame Using Vertical Nonlinear Dynamic Analysis

Progressive Collapse Analysis (PCA) is the base of quantitative assessment of progressive collapse-resisting capacity and progressive collapse-resisting design. There has been heightened interest among researchers of civil engineering in PCA. PCA of planar RC frame is carried on by vertical nonlinear dynamic analysis based on alternate load path method. According to responses of damage structure, progressive collapse-resisting capacity of remaining structure is evaluated. Two cases of removal of elements are analyzed, removal of columns at different stories on the same axes one by one and removal of all columns on the same axes at the same time. According to analysis of the effect of failure duration on structural progressive collapse, it is showed that the response of remaining structure is highly sensitive to failure duration of elements. The results indicate that vertical nonlinear dynamic analysis is an efficient method of progressive collapse-resisting design and progressive collapse-resisting capacity analysis.     

海洋溢油损失评估体系构建

全球海洋溢油事故频繁发生,已经成为影响经济发展、生态平衡、社会稳定发展的重要制约因素。因此,建立一套全面、系统的海洋溢油损失评估体系非常重要。在前人的研究基础上,将海洋溢油损失分为直接损失及间接损失,建立其子评估指标并提供货币化评估模型及方法,运用直接市场法、问卷调查法、替代成本法、成果参照法、碳税法、影子工程法、恢复费用法等一系列评估方法进行构建。构建全面、系统的海洋溢油损失评估体系能对海洋溢油损失进行有效的货币化定量分析,为中国海洋溢油事故后续赔偿、提高溢油事故应急能力等提供依据。     

污染土壤修复标准及修复效果评定方法的探讨

污染土壤修复标准制定的目的是在保证污染土地再利用的前提下,使受到较为严重污染土壤环境中的污染物降低或削减到不足以导致较大的生态损害和健康危害。在分析中国土壤环境质量标准不足的基础上,结合一些发达国家土壤修复标准以及中国土壤污染的实际情况,概述建立污染土壤修复标准应从清洁技术因素、土壤背景值因素、标准法规可调控因素和污染生态毒理学评价方面综合考虑。针对污染土壤修复效果评定的研究,简述植物毒性评定法、陆生无脊椎动物评定法、土壤微生物评定法和生物标记评定法等常用污染土壤修复效果评定方法,并对评定方法的发展前景进行展望。     

多食性害虫大螟发生与防治研究进展

随着种植制度的变更和轻型栽培技术的推广,生产上大螟在局部地区已经由水稻次要害虫变成主要害虫,且有逐年加重趋势。但目前中国稻区多数仍沿用以二化螟为靶标的防治技术体系,亚致死剂量农药反而促进大螟种群增殖。为了加强大螟的防控研究和技术推广,笔者在整理中国大螟近几十年来与防治相关的文献报道基础上,针对大螟多寄主选择、倾向田边产卵等生物学特性、大螟发生与危害逐年加重和边际危害的特点,探讨了以性诱法为主导的预测预报方法,总结了农业防治以减低少虫源基数、生态调控以降低种群数量和科学测报精准施药等方面综合应用的防治技术研究进展,提出了未来研究中需重视大螟预测预报方法完善、大螟抗药性监测和转抗虫基因水稻的抗性风险评估。     

腌制鳙鱼4℃冷藏条件下导电特性与鲜度的相关性

为了研究阻抗技术应用于快速检测低盐腌制鳙鱼冷藏条件下鲜度变化的可行性,在4℃冷藏条件下用质量分数1.1%的食盐腌制鳙鱼,测定了鱼体的阻抗相对变化率Q值和鱼片的感官评分、细菌总数和TVB～N,分析了Q值与感官评分值、细菌总数和TVB-N的相关性,建立了腌制鱼体的Q值与鱼片的感官评分、细菌总数和TVB-N的相关性方程。结果表明,Q值与鱼片的感官评分、细菌总数和TVB-N的相关系数|R|>R_(0.05),利用鱼体Q值预测腌制鳙鱼鱼片的感官评分、细菌总数和TVB-N的准确度分别为76.9%,63.2%,71.1%,4℃冷藏时可以用Q值快速、无损伤地评估低盐腌制鳙鱼的鲜度(p<0.05)。     

Application of Fuzzy Mathematics in the Evaluation of MSW Compost Quality

Through selecting the index of MSW compost quality and establishing the evaluation grades of index, an evaluation system with the method of fuzzy mathematics has been framed in this paper. Then, based on the assessment of single factor and comprehensive effects of different factors, in this paper, the experimental data are taken for example to evaluate the MSW compost quality. The result shows that this method is successfully applied and also can be used as a simple useful method to the evaluation of MSW compost quality.     

Application of Improved Multi-population Genetic Algorithm to Damage Identification of Soil-wall System

The method of damage identification in soil-wall system was studied; a new approach based on improved multi-population genetic algorithm (IMGA) was developed. First, the simplified dynamic-detection model of soil-wall system was established, meanwhile, the theoretical analysis of characteristic equations in soil-wall system was conducted when soil in damage status. The objective function based on characteristic equations was established. Then, the improvements of multi-population genetic algorithm, including the adoption of real-valued representation, adaptive cross operator and adaptive mutation operator, were conducted. Finally, the localization and quantification of the soil-wall system damage were performed by IMGA with and without the consideration of noise, respectively. The results indicate that damage location and damage extent can be detected efficiently, and anti-noise performance is better.     

The Research of Landslide Hazards Assessment System

Landslides caused substantial damage to property,which is seriously hampering social development.With the use of geographic information systems(Arcview),a risk assessment system is established in the paper.The failure probability of 3D-slope is calculated using the Monte Carlo method.The risk of life and economic losses were also calculated by the risk assessment system.By a case study,the results of the risk of life and economic losses may be crucial foundations for administrant branch.     

基于深度卷积神经网络的储粮害虫图像识别

[目的]为了防治储粮害虫带来的危害,借助计算机对储粮害虫进行有效的图像识别是具有重要意义的。[方法]针对基于图像的储粮害虫多分类识别问题,引入了基于深度卷积神经网络的储粮害虫图像识别方法。该方法与传统的储粮害虫识别方法相比,大幅度简化了数据预处理过程,[结果]同时该方法在识别精确度方面达到了97.61%,也明显优于传统方法。[结论]因此基于深度卷积神经网络的储粮害虫识别方法具有较高的实用性,且具有进一步研究和推广的意义。     

基于NDVI的绿洲棉田土壤肥力质量评价方法研究

以天山北坡典型国营农场棉田为研究对象,探讨基于归一化植被指数(NDVI)的棉田土壤肥力质量评价方法.将棉花不同生育期表征长势的NDVI作为评价指标对棉田土壤肥力质量进行评价,再将NDVI与少量理化测定的土壤样点数据(有机质、有效磷含量等)共同作为评价指标,结合地统计方法与遥感影像聚类算法进行评价;并与完全基于土壤样品理化测定数据的评价结果进行比较、探讨基于NDVI评价方法对土壤肥力质量评价结果的准确性与可靠性.研究证明将NDVI与少量理化测定的土壤样点数据作为评价指标,能显著提高评价结果与棉田实际土壤肥力状况的一致性.基于NDVI的土壤肥力质量评价方法快速、简便,其评价结果可为研究绿洲棉田土壤质量及农业结构调整规划、耕地质量保护等提供科学依据.     

Monitoring and Assessment of Tie on the Caiyuanba Yangtze Bridge

The monitoring and assessment scheme of the Caiyuanba Yangtze Bridge is present by sensitivity analysis. The mechanics character of the six ties is studied by numerical simulation, and then the sensor location and selection are discussed considering the technique of sensor and construction situation. The trend of the displacement at the sensor location is analyzed according to different damage level of ties, the pattern associating with several displacements which are sensitive to damage at ties is bring forward to improve assessment reliability. The result can assist implement of structural health monitoring system to the same type as this bridge.