基于FAHP和ANN的锅炉风险评估技术研究

针对传统的锅炉故障诊断方法中神经网络模型结构复杂,信号繁多、训练时间长等缺点,提出了一种基于FAHP和ANN结合的风险评估研究方法;采用FAHP分析锅炉的安全层次结构.通过对影响锅炉安全状态的若干因素之间隶属度的判别,构造出反映人类专家经验与客观事实一致性的模糊矩阵,进而定量地计算出各因素的权重系数;选择权重系数较大的因素作为锅炉安全ANN模型的输入,从而得到锅炉的安全层级;经实际验证,此方法既保留了关键信息,又剔除了冗余信息的干扰,从而简化了ANN的结构,缩短了运算时间,在保持评估准确性的前提下,满足了锅炉安全评估快速性的要求.     

基于改进小波神经网络的信息安全风险评估

由于信息安全风险评估具有非线性、不确定性等特点,采用传统的数学模型进行信息安全的风险评估存在一定的局限性。将人工神经网络(ANN)理论、小波分析及粒子群优化算法有机结合,提出了粒子群-小波神经网络(PWNN)的信息安全风险评估方法。首先,采用模糊评价法对信息安全的风险因素的指标进行量化,对神经网络的输入进行模糊预处理;其次,采用粒子群优化算法对小波神经网络进行训练。仿真结果表明,提出的改进的小波神经网络模型可实现对信息系统的风险因素级别的量化评估,克服现有的评估方法所存在的主观随意性大、结论模糊等缺陷,具有更强的学习能力、更快的收敛速度。     

基于D-AHP和TOPSIS的火电厂控制系统信息安全风险评估

火电厂控制系统信息安全风险评估往往存在主观性强和不确定性等问题,而这些问题会对评估结果产生一定影响.对此,提出一种基于D 数偏好关系改进层次分析法(D-AHP)和逼近理想解排序法(TOPSIS)的电厂控制系统信息安全风险评估方法.根据工业控制系统风险评估的相关行业标准,识别工业控制系统的资产、威胁、脆弱性及现有安全措施,建立评估指标体系和层次结构模型.针对评估专家经验差异导致的评估信息不确定性,先使用D-AHP方法求解各指标影响权重,再使用TOPSIS法求出专家权重,最后得到电厂控制系统信息安全风险值.实例分析表明了所提出方法的有效性,同时提高了评估结果的正确性.     

云重心理论在网络安全风险评估中的应用

研究利用云重心理论进行网络安全风险评估问题.针对传统方法主观因素多,评估过程繁锁,不能彻底解决评估过程存在的大量不确定性和模糊性问题,使得完全客观的评估难以实现的缺点.为解决上述问题,提出把云重心理论应用于网络安全风险评估的方法,用云的重心向量描述网络系统的状态,用加权偏离度描述系统状态相对理想状态的偏离程度,通过定性评测的云发生器来确定系统的安全级别.实例验证了本方法是可行的,并且评估结果较客观、准确.     

区间时间序列的混合预测模型

提出一种基于自回归求和移动平均(ARIMA) 与人工神经网络(ANN) 的区间时间序列混合模型, 并用混合模型分别对区间中值序列和区间半径序列建模. 采用Monte Carlo 方法生成模拟区间序列, 分别用ARIMA、ANN和混合模型3 种方法进行建模和预测实验, 并用统计学方法检验模型误差. 最后分别采用3 种方法对H市轨道交通某号线牵引能耗区间序列进行了建模和预测, 实验结果表明混合模型的建模精度和预测性能均优于单一模型.

     

基于改进BP神经网络的电子政务内网信息安全评估方法

为了发现电子政务内网的信息安全隐患,提出一种采用改进反向传播人工神经网络（BP ANN）技术的电子政务内网信息安全的评估方法,基于改进BP ANN建立电子政务内网神经网络评估模型.以电子政务内网主要信息安全指标作为训练样本,对建立的BP ANN评估模型进行学习和训练,找到输入与输出之间的关系,并用样本对训练好的BP网络进行验证.仿真结果表明,评估方法能够较好的为复杂的电子政务内网进行信息安全评估,评估模型稳定且自适应性强.     

建筑施工项目安全预警系统的仿真研究

研究建筑施工项目安全风险准确评估问题,由于系统存在非线性因素,构建模型较困难.传统评估方法需要样本数目大,而建筑施工项目安全风险是一种典型的小样本数据,导致传统方法的评估精度低.为提高建筑施工项目安全风险评估精度,利用支持向量机专门针对小样本数据建模的优点,提出一种粒子群算法优化支持向量机的建筑施工项目安全预警系统(PSO-SVM).首先采用建筑施工项目安全风险评估正确率作为建模目标,评价指标确定评估模型结构,然后采用粒子群算法优化支持向量机建立评估模型,以克服传统评估方法存的缺陷,以解决建筑施工项目安全风险评估精度的难题.仿真结果表明,相对于神经网络,PSO-SVM提高了风险评估精度,在建筑施工项目管理具有一定的实际应用价值.     

人工神经网络在经济预测中的应用

首先简单介绍了人工神经网络 ANN(Artificial Neural Network)方法,然后通过实例应用与统计回归预测方法进行对比,表明 ANN预测方法是一种可行的,相当于非线性回归的方法,它对用线性回归方法预测效果较差的问题具有独特的优势.     

模糊神经网络在信息安全风险评估中的应用

在信息安全风险评估的研究中,针对提高准确性问题,信息安全风险包含大量模糊、不确定性的影响因素,传统评估方法都是基于精确、确定的数据,因此不适于信息安全风险评估,导致评估的准确性欠佳.为提高信息安全评估的准确性,提出模糊理论与BP神经网络进行结合的信息安全风险评估方法.方法通过模糊理论对信息安全风险因素进行分析,并构造各因素所对应评判集的隶属度矩阵;然后采用BP神经网络对信息安全风险因素隶属度矩阵进行学习,最后输出信息安全风险等级.仿真结果表明,方法能很好地量化评估信息系统风险,提高了风险评估准确性,是一种有效的评估方法.     

基于RBF模糊神经网络的信息安全风险评估

针对传统信息安全风险评估方法的单一性和主观性,提出了新的基于RBF模糊神经网络的信息安全风险评估方法.用模糊集合来模糊化影响评估的因素,构造网络的输入输出,用模糊规则来模拟因素之间的关系,采用增量型模糊神经网络训练方法和批处理型模糊神经网络训练方法相结合的方法来训练网络,并对从模糊规则导出的风险等级去模糊化,得到信息系...     

基于人工神经网络的IT项目风险评价模型

[摘要]：首先本文在构建IT项目风险评价体系的基础上,提出一种基于人工神经网络的多指标综合风险评价模型。其次,利用神经网络的自学习和自适应能力,经过训练的神经网络系统能够将专家评价思想以连接权的方式赋予风险评价模型。最后,通过实际IT项目评价数据的验证,该风险评价模型能够准确地按照专家评价法进行工作。     

SVM和ANN在网络安全风险评估中的比较研究

支持向量机和人工神经网络是人工智能方法的两个分支,详细介绍了支持向量机和人工神经网络原理。建立了网络安全评估指标体系,将支持向量机和人工神经网络同时应用于网络安全风险评估的过程中,通过实例比较了两者的评估效果,结果表明了支持向量机在小样本情况下分类正确率普遍高于人工神经网络,具有较好的分类能力和泛化能力;同时在训练时间上也有绝对的优势。实践证实了支持向量机用于网络安全风险评估的有效性和优越性。     

Performance of artificial neural networks in nearshore wave power prediction

In this paper the assessment of the wave energy potential in nearshore coastal areas is investigated by means of artificial neural networks (ANNs). The performance of the ANNs is compared with in situ measurements and spectral numerical modelling (the conventional tool for wave energy assessment). For this purpose, 13 years of records of two buoys, one offshore and one inshore, with an hourly frequency are used to develop an ANN model for predicting the nearshore wave power. The best suited architecture was selected after assessing the performance of 480 ANN models involving twelve different architectures. The results predicted by the ANN model were compared with the measured data and those obtained by means of the SWAN (Simulating Waves Nearshore) spectral model. The quality in the predictions of the ANN model shows that this type of artificial intelligence models constitutes a powerful tool to forecast the wave energy potential at particular coastal site with great accuracy, and one that overcomes some of the disadvantages of the conventional tools for nearshore wave power prediction.     

Environmental risk assessment of offshore produced water discharges using a hybrid fuzzy-stochastic modeling approach

In recent years, regulators and environmental groups have identified the large volumes of wastewater discharged through offshore petroleum production activities as an issue of concern. In this paper, fuzzy set theory coupled with Monte Carlo analysis have provided a stochastic simulation of pollutant dispersion for the prediction of the environmental risks associated with produced water discharges. With the application of the fuzzy set to data drawn from previous risk-assessment studies, the model allowed the evaluation of various existing pollution standards for marine environments. The present modeling method was validated against data for lead (Pb) levels in the area adjacent to an offshore petroleum facility located on the Grand Banks of Newfoundland, Canada through a multi-year field expedition. The proposed risk-assessment approach contributes to the implementation of effective assessment and management of produced water discharges in the offshore water environment.     

基于最优控制的ANN驾驶员模型与仿真分析

在分析驾驶员行为特性和行为操纵的基础上 ,根据预测跟随理论 ,建立了驾驶员预测控制神经网络 (ANN)模型 ;提出了用最优控制方法确定ANN模型参数的计算方法 ,采用遗传算法 (GA)进行全局优化保证参数的收敛 .对飞机俯仰角操纵进行仿真计算 .结果表明 ,所建立的驾驶员模型考虑了系统的非线性因素 ,实现了多输入多输出功能 ,具有智能特点 .     

Comparison and validation of artificial intelligent techniques to estimate intestinal broiler microflora

This study was carried out to investigate the ability of major mathematical methods to estimate intestinal broiler microflora population. Artificial neural network (ANN), coactive neuro-fuzzy inference system (CANFIC), and artificial neural network genetic algorithm (ANNGA) were used in this respect. The lactic acid bacteria and Enterobacteriaceae were applied as models of microflora. Input and output variables were considered as time and microflora population, respectively. The best model of ANN, CANFIC, and ANNGA was determined based on the coefficient of determination and root mean square error criteria. The results of the current study have shown that ANN, ANNGA, and CANFIS are accurate methods to estimate lactic acid bacteria and Enterobacteriaceae. The highest accuracy of microflora estimation was related to 7 days of age. The efficiency of intelligent models to lactic acid bacteria and Enterobacteriaceae has shown that ANNGA had better prediction between mentioned models. The models estimated Enterobacteriaceae population better than that for lactic acid bacteria.     

Improved estimation of electricity demand function by using of artificial neural network,principal component analysis and data envelopment analysis

Due to various seasonal and monthly changes in electricity consumption and difficulties in modeling it with the conventional methods, a novel algorithm is proposed in this paper. This study presents an approach that uses Artificial Neural Network (ANN), Principal Component Analysis (PCA), Data Envelopment Analysis (DEA) and ANOVA methods to estimate and predict electricity demand for seasonal and monthly changes in electricity consumption. Pre-processing and post-processing techniques in the data mining field are used in the present study. We analyze the impact of the data pre-processing and post-processing on the ANN performance and a 680 ANN-MLP is constructed for this purpose. DEA is used to compare the constructed ANN models as well as ANN learning algorithm performance. The average, minimum, maximum and standard deviation of mean absolute percentage error (MAPE) of each constructed ANN are used as the DEA inputs. The DEA helps the user to use an appropriate ANN model as an acceptable forecasting tool. In the other words, various error calculation methods are used to find a robust ANN learning algorithm. Moreover, PCA is used as an input selection method, and a preferred time series model is chosen from the linear (ARIMA) and nonlinear models. After selecting the preferred ARIMA model, the Mcleod–Li test is applied to determine the nonlinearity condition. Once the nonlinearity condition is satisfied, the preferred nonlinear model is selected and compared with the preferred ARIMA model, and the best time series model is selected. Then, a new algorithm is developed for the time series estimation; in each case an ANN or conventional time series model is selected for the estimation and prediction. To show the applicability and superiority of the proposed ANN-PCA-DEA-ANOVA algorithm, the data regarding the Iranian electricity consumption from April 1992 to February 2004 are used. The results show that the proposed algorithm provides an accurate solution for the problem of estimating electricity consumption.     

A moving-average filter based hybrid ARIMA–ANN model for forecasting time series data

A suitable combination of linear and nonlinear models provides a more accurate prediction model than an individual linear or nonlinear model for forecasting time series data originating from various applications. The linear autoregressive integrated moving average (ARIMA) and nonlinear artificial neural network (ANN) models are explored in this paper to devise a new hybrid ARIMA–ANN model for the prediction of time series data. Many of the hybrid ARIMA–ANN models which exist in the literature apply an ARIMA model to given time series data, consider the error between the original and the ARIMA-predicted data as a nonlinear component, and model it using an ANN in different ways. Though these models give predictions with higher accuracy than the individual models, there is scope for further improvement in the accuracy if the nature of the given time series is taken into account before applying the models. In the work described in this paper, the nature of volatility was explored using a moving-average filter, and then an ARIMA and an ANN model were suitably applied. Using a simulated data set and experimental data sets such as sunspot data, electricity price data, and stock market data, the proposed hybrid ARIMA–ANN model was applied along with individual ARIMA and ANN models and some existing hybrid ARIMA–ANN models. The results obtained from all of these data sets show that for both one-step-ahead and multistep-ahead forecasts, the proposed hybrid model has higher prediction accuracy.     

人工神经网络在混沌观测时序数据处理中的应用

人工神经网络是用来模拟人脑智能特点和结构的一种模型,具有很强的非线性映射功能。把它引用到观测序列数据的分析处理中,可为观测数据的分析处理提供一种新方法的方法,也是对人工神经网络方法应用的推广。文中分析了时间序列的可预测性,给出了用人工神经网络预测和处理混沌观测时间序列的方法,并给出了应用实例。结果表明：用该方法处理能达到较高的精度。     

Neural Network and Classification Approach in Identifying Customer Behavior in the Banking Sector: A Case Study of an International Bank

The customer relationship focus for banks is in development of main competencies and strategies of building strong profitable customer relationships through considering and managing the customer impression, influence on the culture of the bank, satisfactory treatment, and assessment of valued relationship building. Artificial neural networks (ANNs) are used after data segmentation and classification, where the designed model register records into two class sets, that is, the training and testing sets. ANN predicts new customer behavior from previously observed customer behavior after executing the process of learning from existing data. This article proposes an ANN model, which is developed using a six‐step procedure. The back‐propagation algorithm is used to train the ANN by adjusting its weights to minimize the difference between the current ANN output and the desired output. An evaluation process is conducted to determine whether the ANN has learned how to perform. The training process is halted periodically, and its performance is tested until an acceptable result is obtained. The principles underlying detection software are grounded in classical statistical decision theory.