基于变精度粗糙集理论的组合预测方法研究

组合预测的关键是确定各个单模型预测方法的加权系数。文章首先给出了一种基于标准粗糙集理论的组合预测方法,将加权系数确定问题转化为标准粗糙集理论中属性重要性评价问题,通过引入目标函数,提出了一种基于变精度粗糙集理论的寻找组合预测加权系数的新方法。仿真实验表明,基于变精度粗糙集理论的组合预测方法计算量小,不带有主观性,预测精度高。     

航材消耗广义加权函数比例平均组合预测模型

提出一种新的组合预测模型--广义加权函数比例平均组合预测模型,并利用二次规 划算法给出其加权系数的参数估计方法.同时,针对航材消耗的季节性与波动性特点,建立了航 材消耗预测的灰色系统模型与神经网络模型,最后建立了基于灰色系统与神经网络的航材消耗 广义加权函数比例平均组合预测模型并以实例说明了其预测效果.     

广义加权最小二乘组合预测法在装备故障率预测中的应用

为了准确预测武器装备的故障率,针对实验数据少,随机因素影响较大的特点,在最小二乘法的基础上,构建广义加权组合预测模型,把最小二乘法与加权组合预测法有机的结合起来.在Matlab环境下,通过最小二乘法确立多个单项预测模型,经过广义加权组合法综合不同模型的信息,利用非线性规划法求解最优权系数.通过实际数例的仿真计算,证明了广义加权最小二乘组合预测模型能有效的降低预测误差,提高预测精度.     

基于最优加权组合模型的道路交通事故预测

交通事故预测是交通安全评价、规划和决策的基础。针对各种单一灰色预测模型存在的局限性,建立了一种基于最优加权的灰色组合预测模型。根据我国道路交通事故的发展情况,建立了GM（1,1）、Verhulst和SCGM（1,1）c相结合的组合预测模型,运用最优加权法确定组合预测模型的权重系数。利用2001-2007年我国道路交通事故死亡人数的实际值作为原始数据,构建各个单一预测模型和最优组合预测模型,预测其2008-2010年交通事故死亡人数。预测结果表明,组合预测模型比单一GM（1,1）模型、Verhulst模型和SCGM（1,1）c模型具有更高的预测精度。     

改进IOWHA算子组合预测模型

针对现有单项预测模型提供信息有限,预测误差大的问题,引用最优加权组合建模理论,将灰色关联度与IOWHA算子相结合,提出一种新的组合预测模型权重确定方法,并应用该权重确定方法构建了一种基于RBF神经网络预测模型和GM预测模型的最优组合预测模型。该模型能够克服传统组合预测方法的两个缺陷：加权平均系数不变和以单一误差指标为准则。利用该组合模型对全国物流需求进行组合预测,并与RBF神经网络模型、GM模型的预测结果进行了对比分析。结果表明,相对于单项预测模型,该组合预测模型的预测精度更高,是一种有效的物流需求预测模型。     

基于熵值法的网络安全态势组合预测模型

研究网络优化入侵检测问题,网络安全态势受网络攻击行为、病毒、自身漏洞、木马等多种因素影响,具有高度的非线性、时变性、突变性等复杂特点,采用传统单一预测方法只能反映部分信息,无法进行准确的预测。为提高网络安全态势预测精度,提出一个熵值学的网络安全态势组合预测模型。首先利用熵值法为单一网络安全态势预测模型分配加权系数,然后根据单一模型的预测结果进行加权运算,得到了网络安全态势的组合预测结果,最后利用具体网络安全态势数据进行仿真测试。仿真结果表明,组合预测模型提高了网络安全态势预测精度,为网络安全态势预测提供了一种新的解决途径。     

基于XGBoost和LSTM加权组合模型在销售预测的应用

针对多变量的商品销售预测问题,为了提高预测的精度,提出了一种ARIMA-XGBoost-LSTM加权组合方法,对具有多个影响因素的商品销售序列进行预测,本文采用ARIMA做单变量预测,将预测值作为新变量同其他变量一起放入XGBoost模型中进行不同属性的挖掘,并将XGBoost的预测值合并到多变量序列中,然后通过将新的多维数据转换为监督学习序列后利用LSTM模型进行预测,将3种模型预测结果进行加权组合,通过多次实验得出最佳组合的权值,以此计算出最终的预测值.数据结果表明,基于XGBoost和LSTM的加权组合的多变量预测方法比单一的预测方法所得到的预测值更为精准.     

基于PCA-ANN组合学习方法建立PTA粒度模型

针对在精对苯二甲酸(PTA)生产过程中影响PTA粒度的因素多且复杂，采用了主元分析方法(PCA)提取方差最大的几个成分作为神经网络(ANN)的输入，消除干扰因素的影响，建立PCA-ANN粒度模型。为了进一步提高PCA-ANN粒度模型的预测精度，提出了性能优良的加权组合学习方法，形成基于PCA-ANN的加权组合模型。组合模型能通过对多个不同PCA-ANN粒度模型的预测结果进行自适应加权。最终获得具有良好预测精度的结果。     

基于模糊组合变量的自适应加权控制

针对多变量非线性系统,提出一种基于模糊组合变量的自就加权控制方法,首先利用模糊逻辑系统构造模糊组合变量,通过赋予各个模糊组合变量不同的权重来形成多变量非线性系统的加权控制;然后利用反向传播算法对量化系数和加权系数进行学习,从而有效地解决了多变量模糊控制系统难以设计和实现多维控制器的问题,最后通过仿真实验证明了该方法的有效性。     

基于组合模型的时栅信号处理系统健康状况预测

为了保障时栅传感系统稳定性、提高测量精度,提出一种基于ELMAN神经网络和灰色模型组合预测的时栅信号处理系统健康状况预测方法。采用克朗巴哈系数法分析确定激励信号幅值、相位为预测参数。基于ELMAN神经网络及灰色模型,结合加权-比例-平均思想实现了组合模型建模。根据系统运行实际,以幅值和相位的相对误差为指标,制定健康诊断标准。实验结果表明,组合模型预测结果的相对误差、预测均方差和相对系数分别为0.101 6、0.011 9和0.988 5,预测误差小、相关性高。经健康诊断标准判定,健康状况预测结果与电路实际相符。该健康状况预测方法预测精度高,且明显高于单一模型,满足提前准确获悉电路系统健康状况的要求。     

A novel dynamic progress forecasting approach for construction projects

In this paper, we propose a novel construction project progress forecasting approach which combines the grey dynamic prediction model and the residual modified model to forecast the current progress during the construction phase. Firstly, four typical S-curves simplified from various sigmoid curves are proposed and fitted to the grey dynamic prediction model. For higher prediction accuracy, three different residual modified models are taken to amend the initial prediction value which was derived from the above step. The mean absolute percentage error (MAPE) and standard deviation of the estimate of Y (SDY) are used to assess the accuracy of the composite results. The better residual modified prediction model is adopted to combine the grey dynamic prediction model to form the novel progress forecasting approach. Then, practical completed construction cases are provided for testing the prediction ability of the proposed progress forecasting approach. Results show that the forecasting approach proposed to forecast construction progress during construction phase is able to get better prediction accuracy almost within 10% whether typical S-curves or practical cases. The new approach relatively provides an accurate, simple and stable method for predicting construction progress in comparison with the previous traditional forecasting methods.     

Multi-model ensemble prediction model for carbon efficiency with application to iron ore sintering process

Iron ore sintering is one of the most energy-consuming process in steel industry. Accurate prediction of carbon efficiency for this process is beneficial to energy savings and consumption reduction. Considering the sintering process exhibits strong nonlinearities, multiple parameters, multiple operating conditions, etc., a multi-model ensemble prediction model based on the actual run data is developed to achieve the high-precision prediction of carbon efficiency. It takes the comprehensive coke ratio (CCR) as a metric (index) of carbon efficiency in the sintering process. First, an affinity propagation clustering algorithm is used to realize the automatic identification of multiple operating conditions. Then, different models are established under different operating conditions by using the proposed least squares support vector machine (LS-SVM) with hybrid kernel modeling method. Finally, a partial least-squares regression method is employed as an ensemble strategy to combine the different models to form the multi-model ensemble prediction model for the CCR. The simulation results involving the actual run data demonstrate that the proposed model can predict the CCR accurately when compared with other prediction methods. The results of actual runs show that the coefficient of determination for the proposed model is 0.877. The proposed model satisfies the requirements of actual sintering process and enables the real-time prediction.     

Evolving Recurrent Neural Network using Cartesian Genetic Programming to Predict The Trend in Foreign Currency Exchange Rates

Forecasting the foreign exchange rate is an uphill task. Numerous methods have been used over the years to develop an efficient and reliable network for forecasting the foreign exchange rate. This study utilizes recurrent neural networks (RNNs) for forecasting the foreign currency exchange rates. Cartesian genetic programming (CGP) is used for evolving the artificial neural network (ANN) to produce the prediction model. RNNs that are evolved through CGP have shown great promise in time series forecasting. The proposed approach utilizes the trends present in the historical data for its training purpose. Thirteen different currencies along with the trade-weighted index (TWI) and special drawing rights (SDR) is used for the performance analysis of recurrent Cartesian genetic programming-based artificial neural networks (RCGPANN) in comparison with various other prediction models proposed to date. The experimental results show that RCGPANN is not only capable of obtaining an accurate but also a computationally efficient prediction model for the foreign currency exchange rates. The results demonstrated a prediction accuracy of 98.872 percent (using 6 neurons only) for a single-day prediction in advance and, on average, 92% for predicting a 1000 days’ exchange rate in advance based on ten days of data history. The results prove RCGPANN to be the ultimate choice for any time series data prediction, and its capabilities can be explored in a range of other fields.     

一种基于主题模型的软件缺陷预测技术研究

软件缺陷预测通常针对代码表面特征训练预测模型并对新样本进行预测,忽视了代码背后隐藏的不同技术方面和主题,从而导致预测不准确。针对这种问题,提出了一种基于主题模型的软件缺陷预测方法。将软件代码库视为不同技术方面和主题的集合,不同的主题或技术方面有不同的缺陷倾向。采用LDA主题模型对不同主题及其缺陷倾向进行建模,根据建模结果计算主题度量,并将传统度量方式和主题度量结合进行模型训练和预测。实验结果显示,该方法相对传统的软件缺陷预测技术有高的准确性,并且可以在软件演化中保证模型相对稳定,可以适用于各种缺陷预测任务。     

基于信息融合的电信客户流失预测研究

针对数据挖掘方法在电信客户流失预测中的局限性,提出将信息融合与数据挖掘相结合,分别从数据层、特征层、决策层构建客户流失预测模型。确定客户流失预测指标;根据客户样本在特征空间分布的差异性对客户进行划分,得到不同特征的客户群;不同客户群采用不同算法构建客户流失预测模型,再通过人工蚁群算法求得模型融合权重,将各模型的预测结果加权得到预测最终结果。实验结果表明,基于信息融合的客户流失预测模型确实比传统模型更优。     

BS-SC Model: A Novel Method for Predicting Child Abuse Using Borderline-SMOTE Enabled Stacking Classifier

For a long time, legal entities have developed and used crime prediction methodologies. The techniques are frequently updated based on crime evaluations and responses from scientific communities. There is a need to develop type-based crime prediction methodologies that can be used to address issues at the subgroup level. Child maltreatment is not adequately addressed because children are voiceless. As a result, the possibility of developing a model for predicting child abuse was investigated in this study. Various exploratory analysis methods were used to examine the city of Chicago’s child abuse events. The data set was balanced using the Borderline-SMOTE technique, and then a stacking classifier was employed to ensemble multiple algorithms to predict various types of child abuse. The proposed approach successfully predicted crime types with 93% of accuracy, precision, recall, and F1-Score. The AUC value of the same was 0.989. However, when compared to the Extra Trees model (17.55), which is the second best, the proposed model’s execution time was significantly longer (476.63). We discovered that Machine Learning methods effectively evaluate the demographic and spatial-temporal characteristics of the crimes and predict the occurrences of various subtypes of child abuse. The results indicated that the proposed Borderline-SMOTE enabled Stacking Classifier model (BS-SC Model) would be effective in the real-time child abuse prediction and prevention process.     

基于LightG BM 的高校就业预测模型

In view of the characteristics of high-dimensional, unbalanced and multi-category employment data, in order to further im- prove the accuracy of decision tree method in the employment prediction of college students, an employment prediction model based on LightGBM is proposed. First the improved ADASYN sampling algorithm is used to increase the minority class in the data sam- ple, and then the employment data after balance is used for training LightGBM algorithm, and Bayesian model is used for parameter optimization to get the final employment prediction. Finally the prediction model is analyzed to measure the influence of each fea- ture on employment. The validity of the proposed method is verified through the data set of unbalanced employment data of college graduates, and compared with various unbalanced classification methods. It is proved that the proposed model has better prediction performance.     

基于自适应混合优化的电力数据预测方法

电力数据易受气候、季节、节假日等因素影响,出现不同波动特征.针对不同特征电力数据预测精度不高、预测方法泛化能力弱等问题,提出基于自适应混合优化的电力数据预测方法 .通过使用小波变换和平稳性分析,将电力数据自适应地分解为包含趋势、季节和周期信息的非平稳序列和多个平稳序列;使用状态转移算法分别优化长短时记忆深度学习网络和自回归移动平均模型,对非平稳序列和平稳序列分别拟合、预测;对预测的各序列进行重构,得到最终预测结果.在电力系统数据上进行多步预测,对比实验表明:与其他方法相比,所提方法不仅具有更高的预测精度,还具有较强的泛化能力.     

下采样和插值同一性的实现及其应用

针对常用的图像下采样方法无法满足不同应用需要的问题,提出下采样和插值在实现技术上具有同一性的特点,下采样可以采用插值的大量先进技术。将下采样与插值均看作是对邻域未知像素的预测,建立了统一的像素预测模型。实验结果验证了该同一性的思想,并表明与常用的下采样方法相比,在具有保持特征、保护边缘、维持平滑等特性的基础上,能够使下采样后的图像保持更多的信息,从而为下采样在不同应用中的实现提供了更多可选择的方法。     

基于深度时序特征迁移的轴承剩余寿命预测方法

不同工况下轴承退化数据分布不一致导致深度学习等方法对剩余寿命预测效果有限,而已有迁移学习预测方法未能充分挖掘不同工况退化序列的内在趋势性,为此,提出一种基于深度时序特征迁移的轴承剩余寿命预测方法.首先,提出一种深度时序特征融合的健康指标构建模型,利用时间卷积网络挖掘退化趋势的内在时序特征,得到源域多轴承的健康指标;然后,提出一种最小化序列相似度的领域自适应算法,利用源域健康指标作为退化趋势元信息,选取目标域与源域之间的公共敏感特征;最后,采用支持向量机构建预测模型.在IEEE PHM Challenge 2012 轴承全寿命数据集上进行实验,结果表明,所提出方法构建的健康指标可更有效地反映退化趋势,同时明显提升剩余寿命预测的准确度.