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Fuzzy Clustering Based Regression Model Forecasting: Weighted By Gustafson-Kessel Algorithm 基于Gustafson-Kessel算法加权的模糊聚类回归模型预测
Pub Date : 2020-12-16 DOI: 10.34110/forecasting.778616
N. Erilli
Regression analysis is one of the well-known methods of multivariate analysis and it is efficiently used in many research fields, especially forecasting problems. In order for the results of regression analysis to be effective, some assumptions must be valid. One of these assumptions is the heterogeneity problem. One of the methods used to solve this problem is the weighted regression method. Weighted regression is a useful method when one of the least-squares assumptions of constant variance in the residuals is violated (heteroscedasticity). This procedure can minimize the sum of weighted squared residuals to produce residuals with a uniform variance if the appropriate weight will be used. (homoscedasticity). In this study, the Gustafson-Kessel method, one of the fuzzy clustering analysis method, is used to determine weights for weighted regression analysis. GustafsonKessel's method is based on the minimization of the sum of weighted squared distances which is used Mahalanobis distance, between the data points and the cluster centres. With the fuzzy clustering method, each observation value is bound to the specified clusters in a specific order of membership. These membership degrees will be calculated as weights in the weighted regression analysis and estimation work will be done. In application, 5 simulation and 1 real-time data were estimated by the proposed method. The results were interpreted by comparing with Robust Methods (M and S estimator) and weighted with FCM Regression analysis. 2020 Turkish Journal of Forecasting by Giresun University, Forecast Research Laboratory is licensed under a Creative Commons Attribution-ShareAlike 4.0 International License.
回归分析是众所周知的多变量分析方法之一,在许多研究领域,特别是预测问题中得到了有效的应用。为了使回归分析的结果是有效的,一些假设必须是有效的。其中一个假设是异质性问题。解决这一问题的方法之一是加权回归法。当残差中方差恒定的最小二乘假设之一被违反(异方差)时,加权回归是一种有用的方法。如果使用适当的权重,则该程序可以最小化加权平方残差的总和,以产生具有均匀方差的残差。(方差齐性)。本研究采用模糊聚类分析方法之一的Gustafson-Kessel法确定权重进行加权回归分析。GustafsonKessel的方法是基于数据点和聚类中心之间的加权平方距离之和的最小化,该方法使用马氏距离。使用模糊聚类方法,每个观测值以特定的隶属度顺序绑定到指定的聚类中。这些隶属度将在加权回归分析和估计工作中作为权重计算。在实际应用中,利用该方法对5个仿真数据和1个实时数据进行了估计。通过比较稳健方法(M和S估计器)和FCM回归分析加权来解释结果。2020土耳其预测杂志由Giresun大学预测研究实验室根据知识共享署名-相同方式共享4.0国际许可协议授权。
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引用次数: 0
Forecasting of Onion Sown Area and Production in Turkey Using Exponential Smoothing Method 指数平滑法预测土耳其洋葱播种面积和产量
Pub Date : 2019-12-31 DOI: 10.34110/forecasting.660377
Bakiye Kılıç Topuz, M. Bozoğlu, Nevra Alhas Eroğlu, Uğur Başer
In 2017, 144 countries in the world produced 97.862.928 tons onion at 5.201.591 hectares. Turkey produced 2.1 million tons onion in 68 thousand hectares. Turkey was the seventh-largest producer country of dry onion with a share of 2,18% in the world. The main aim of this research was to forecast the onion area and production of Turkey for the period of 2019-2026. The data of this study was obtained from the database of the Food and Agriculture Organization and the time series covered the period of 1961-2018. Three Exponential Smoothing Methods were compared to model onion area and production and Holt Exponential Smoothing model was determined as the most appropriate forecasting model. In the study, time series data were determined as non-stationary and so, stationarity was obtained after taking the first difference of the time series. Model results show that, in the 2019-2026 period, the forecasted sown area of onion would be increased from 58.873 hectares to 60.981 hectares, forecasted production of onion would be increased from 2.066.453 tons to 2.309.751 tons. In order to reduce the effect of Cobweb theorem, onion production should be planned by producer organizations. The supply gap can be avoided by taking appropriate policy measures and this is necessary to maintain Turkey’s position in the world onion market.
2017年,世界上144个国家在5.201.591公顷的土地上生产了97.862.928吨洋葱。土耳其在6.8万公顷土地上生产了210万吨洋葱。土耳其是干洋葱的第七大生产国,占世界份额的2.18%。本研究的主要目的是预测2019-2026年土耳其的洋葱面积和产量。本研究的数据来自联合国粮食及农业组织的数据库,时间序列涵盖1961-2018年。比较了3种指数平滑模型对洋葱面积和产量的预测效果,确定Holt指数平滑模型为最合适的预测模型。在本研究中,时间序列数据被确定为非平稳,因此取时间序列的一阶差分后获得平稳性。模型结果表明,2019-2026年,预测洋葱播种面积将从58.873公顷增加到60.981公顷,预测洋葱产量将从2.066.453吨增加到2.309.751吨。为了减少蛛网定理的影响,洋葱生产应由生产者组织进行计划。供应缺口可以通过采取适当的政策措施来避免,这对于维持土耳其在世界洋葱市场的地位是必要的。
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引用次数: 0
Estimating Risk Pressure Factor (RPF) with Artificial Neural Network (ANN) to Locate Search and Rescue (SAR) Team Station. 基于人工神经网络(ANN)的风险压力因子估算在搜救队站定位中的应用。
Pub Date : 2019-08-31 DOI: 10.34110/forecasting.484765
Irfan Macit
Earthquake is one of the natural disaster types that suddenly breaks regular human life. Rescue activities in disasters are one of the most critical stages of modern disaster management. This management stage, as mentioned earlier, includes all the activities that need to be done after the disaster. Search And Rescue (SAR) teams perform one of these most critical activities after the earthquake post-disaster period. Search and rescue teams that will rescue and relief after a disaster are selected according to the criteria selected. Location layout selection problems are NP-Hard, and obtaining hard results is in the class of these problems. One of these criteria is the Risk Pressure Factor (RPF) used in determining the priorities of the risk areas. Determining the level of risk level is very difficult and also these are difficult to predict. In this study, it is aimed to estimate this parametric value by using an artificial neural network (ANN) method which is applied in many fields. And then in this study, a prediction model was constructed by using back propagation method which is a suitable propagation method in ANN method and results are obtained from the MATLAB program. The resulting risk-pressure factor (RPF) value can be used as a parameter in the proposed mathematical model. As a result of the study, the missing parameter of the mathematical model will be found in the estimation of a parameter belonging to the proposed mathematical model.
地震是一种突然打破人类正常生活的自然灾害类型。灾害救援活动是现代灾害管理的关键环节之一。如前所述,这个管理阶段包括灾后需要完成的所有活动。搜索和救援(SAR)小组在地震后的灾后阶段执行这些最关键的活动之一。根据选定的标准,选出进行灾后救援的搜救队伍。位置布局选择问题是NP-Hard问题,获得硬结果属于这类问题。其中一个标准是风险压力系数(RPF),用于确定风险领域的优先级。确定风险等级是非常困难的而且这些也很难预测。本研究旨在利用人工神经网络(ANN)方法估计该参数值,该方法在许多领域都有应用。在此基础上,利用神经网络方法中较适合的反向传播方法构建了预测模型,并通过MATLAB程序得到了预测结果。得到的风险压力因子(RPF)值可以作为所提出的数学模型的参数。研究的结果是,在对属于所提出的数学模型的参数进行估计时,会发现数学模型中缺失的参数。
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引用次数: 0
Genetic Algorithms Applied to Fractional Polynomials for Power Selection: Application to Diabetes Data 遗传算法应用于分数多项式的权力选择:在糖尿病数据中的应用
Pub Date : 2019-08-31 DOI: 10.34110/forecasting.514761
Barnabe Ndabashinze, Gülesen Üstündağ Şiray, L. Scrucca
Fractional polynomials are powerful statistic tools used in multivariable building model to select relevant variables and their functional form. This selection of variables, together with their corresponding power is performed through a multivariable fractional polynomials (MFP) algorithm that uses a closed test procedure, called function selection procedure (FSP), based on the statistical significance level α. In this paper, Genetic algorithms, which are stochastic search and optimization methods based on string representation of candidate solutions and various operators such as selection, crossover and mutation; reproducing genetic processes in nature, are used as alternative to MFP algorithm to select powers in an extended set of real numbers (to be specified) by minimizing the Bayesian Information Criteria (BIC). A simulation study and an application to a real dataset are performed to compare the two algorithms in many scenarios. Both algorithms perform quite well in terms of mean square error with Genetic algorithms that yied a more parsimonious model comparing to MFP Algorithm .
分数阶多项式是多变量构建模型中选择相关变量及其函数形式的有力统计工具。变量的选择及其相应的功率通过多变量分数多项式(MFP)算法进行,该算法使用基于统计显著性水平α的封闭测试程序,称为函数选择程序(FSP)。遗传算法是一种基于候选解的字符串表示和选择、交叉、变异等多种操作的随机搜索和优化方法;通过最小化贝叶斯信息准则(BIC),在扩展的实数集合(待指定)中选择幂。通过仿真研究和对实际数据集的应用,比较了两种算法在许多场景下的应用。两种算法在均方误差方面都表现良好,遗传算法与MFP算法相比产生了更简洁的模型。
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引用次数: 1
Forecasting of Apricot Production of Turkey by Using Box-Jenkins Method Box-Jenkins法预测土耳其杏产量
Pub Date : 2018-12-31 DOI: 10.34110/forecasting.482914
Bakiye Kılıç Topuz, M. Bozoğlu, Uğur Başer, Nevra Alhas Eroğlu
Turkey is the first largest apricot producer in the world. In 2016, Turkey was responsible for 9,21% of world apricot production with 730 thousand tons. Turkey also generated 11,31% of world apricot exports in 2016. The main aim of this research was to forecast apricot production of Turkey for the period of 2017-2022. The data of this study was obtained from the database of the Food and Agriculture Organization and the time series covered the period of 1961-2016. Box-Jenkins Model was used to forecast apricot production. In the study, it was determined that the time series were not stationary and the series became stationary after the first difference was taken. Moving Average Model ARIMA (2, 1, 1) was determined as the most appropriate model for the stationary data type. The research results show that apricot production quantities of Turkey in 2017 was forecasted as minimum 383.206 tons, maximum 920.409 tons and, average 651.808 tons. However, Turkey’s the apricot production amount in 2022 was forecasted as minimum 271.734 tons, maximum 1.193.113 tones and average 732.423 tons. Considering the increase in demand, it is thought that apricot production will not be sufficient for the country. To protect the current leading position of the country, it is recommended that the government should give enough support to increase apricot production in Turkey.
土耳其是世界上第一大杏子生产国。2016年,土耳其杏产量为73万吨,占世界杏产量的9.21%。2016年,土耳其的杏子出口量也占世界杏子出口量的11.31%。本研究的主要目的是预测2017-2022年土耳其杏的产量。本研究数据来源于联合国粮农组织数据库,时间序列为1961-2016年。采用Box-Jenkins模型对杏产量进行预测。在本研究中,确定时间序列不平稳,在取第一次差分后,序列变得平稳。移动平均模型ARIMA(2,1,1)被确定为最适合平稳数据类型的模型。研究结果表明,预测2017年土耳其杏产量最小383.206吨,最大920.409吨,平均651.808吨。但是,预计土耳其2022年杏树产量最低为271.734吨,最高为1.193.113吨,平均为732.423吨。考虑到需求的增加,人们认为杏的产量将不足以满足该国的需求。为了保护该国目前的领先地位,建议政府应给予足够的支持,以增加土耳其杏的产量。
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引用次数: 10
Forecasting Chestnut Production and Export of Turkey Using ARIMA Model 利用ARIMA模型预测土耳其板栗产量和出口
Pub Date : 2018-12-31 DOI: 10.34110/forecasting.482789
Uğur Başer, M. Bozoğlu, Nevra Alhas Eroğlu, Bakiye Kılıç Topuz
Turkey is one of main producers and exporter countries of chestnut in the world. It is essential to assess scientifically the accurate future production and export potentials of chestnut on the basis of past trends. This study focuses on forecasting the chestnut production and export of Turkey up to the year 2021 using Autoregressive Integrated Moving Average (ARIMA) model. The time series data for the chestnut production and export of Turkey were obtained from the Food and Agriculture Organization of the United Nations (FAO). Annual data for the period of 1961-2016 was used for the study. The study revealed that the best models for forecasting the chestnut production and export were ARIMA (1, 1, 1) and ARIMA (1, 2, 1), respectively. The ARIMA model showed that while the chestnut production of Turkey in 2021 would be 64.183 tonnes with lower limit of 38.946 tonnes and upper limit of 89420 tonnes. However, Turkey’s chestnut export in 2021 would be 7.962 tonnes with lower limit of 563 tonnes and upper limit of 15362 tonnes. The study concluded that Turkey’s chestnut production and export will increase in the forecasted years. The stakeholders of chestnut sector should take account these projections in their production and marketing decision.
土耳其是世界上板栗的主要生产国和出口国之一。在过去趋势的基础上,科学准确地评估板栗的未来生产和出口潜力至关重要。本研究的重点是使用自回归综合移动平均(ARIMA)模型预测土耳其到2021年的板栗产量和出口。土耳其板栗生产和出口的时序数据来自联合国粮食及农业组织(FAO)。该研究使用了1961-2016年的年度数据。结果表明,预测板栗产量和出口的最佳模型分别为ARIMA(1,1,1)和ARIMA(1,2,1)。ARIMA模型显示,2021年土耳其板栗产量为64.183吨,下限为38.946吨,上限为89420吨。然而,土耳其2021年的板栗出口将为7.962吨,下限为563吨,上限为15362吨。该研究的结论是,土耳其板栗的生产和出口将在预测的几年内增加。板栗部门的利益相关者应在其生产和销售决策中考虑这些预测。
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引用次数: 6
G-STAR Model for Forecasting Space-Time Variation of Temperature in Northern Ethiopia 预报埃塞俄比亚北部气温时空变化的G-STAR模式
Pub Date : 2018-09-01 DOI: 10.34110/FORECASTING.437599
M. Zewdie, Gebretsadik G Wubit, A. W. Ayele
Among many indicators of climate change, the temperature is a key indicator to take remedial action for world global warming. This finding provides application of space-time models for temperature data, which is selected in three meteorology stations (Mekelle, Adigrat and Adwa) of Northern Ethiopia. The objectives of this research are to see the space-time variations of temperature and to find better forecasting model. The steps for building this model starting from order selection of space and autoregressive order, parameters estimation, a diagnostic check of errors and finally forecasting for the long term. The preliminary model is identified by VAR (vector autoregressive) model and tentatively selects the order by using MIC (minimum information criteria) and uses the autoregressive order for the model and fixes the spatial effect, model parameters are estimated using the least square method. Weighted matrix computed by using queen contiguity criteria. It is found that the model STAR(1,1) and GSTAR(1,1) are two options, finally the best-fitted model is GSTAR(1,1) which has high forecasting performance and smallest RMSEF. The outcome of the forecast indicated that in northern Ethiopia, the weather conditions especially temperature of future is increasing trend in dry seasons in all 3 stations in similar fashion but more consistent and has less variation across the region, and less consistent and high variation within the region and the researcher found that spatial effect has high impact on prediction of models.
在众多气候变化指标中,气温是对全球变暖采取补救措施的关键指标。这一发现为埃塞俄比亚北部三个气象站(Mekelle、Adigrat和Adwa)选择的温度数据提供了时空模型的应用。本研究的目的是了解温度的时空变化,寻找更好的预测模型。建立该模型的步骤从空间的顺序选择和自回归顺序开始,参数估计,错误诊断检查,最后进行长期预测。采用向量自回归模型VAR (vector autoregressive model)对模型进行识别,采用最小信息准则MIC (minimum information criteria)对模型进行初步阶数选择,采用自回归阶数对模型进行空间效应修正,采用最小二乘法对模型参数进行估计。采用皇后邻接准则计算加权矩阵。发现模型STAR(1,1)和GSTAR(1,1)是两种选择,最终拟合最好的模型是预测性能高、RMSEF最小的GSTAR(1,1)模型。预测结果表明,在埃塞俄比亚北部,3个站点的天气条件特别是未来温度在旱季均呈上升趋势,趋势相似,但一致性较强,区域间变化较小,区域内变化较小,一致性较差,空间效应对模式预测影响较大。
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引用次数: 1
Stock Market Prediction Using Nonparametric Fuzzy and Parametric GARCH Methods 非参数模糊和参数GARCH方法的股票市场预测
Pub Date : 2018-09-01 DOI: 10.34110/FORECASTING.420126
R. A. Belaghi, Minoo Aminnejad, Ozlem Gurunlu Alma
Prediction of stock market value is one the most complicated issue during the past decades. Due to its importance, in this research, we consider the prediction of stock values based on non-parametric and parametric methods. In this first method, we use the fuzzy Markov chain procedure in order to prediction problem. In this regard, all of the rising and falling probabilities during the weekdays are calculated and then they applied to obtain the increasing and decreasing rate. Then, based on this information we model and predict the stock values. In the sequel, we implement different methods of parametric time series such as generalized autoregressive conditionally heteroskedastic (GARCH), ARIMA-GARCH, Exponential GARCH (E-GARCH) and GJR-GARCH by assuming the normal and t-student distribution for the error terms to obtain the best model in terms of minimum mean square errors. Finally, the mythologies developed here are applied for the Tehran Stock Exchange Index (TEDPIX).
股票市场价值的预测是过去几十年来最复杂的问题之一。鉴于其重要性,在本研究中,我们考虑了基于非参数和参数方法的股票价值预测。在第一种方法中,我们使用模糊马尔可夫链过程来解决预测问题。在这方面,所有的上升和下降的概率在工作日内计算,然后应用它们得到上升和下降的速度。然后,根据这些信息对股票价值进行建模和预测。在后续文章中,我们通过假设误差项的正态分布和t-student分布,实现了参数时间序列的广义自回归条件异方差(GARCH)、ARIMA-GARCH、指数GARCH和GJR-GARCH等不同的方法,以获得均方误差最小的最佳模型。最后,这里开发的神话应用于德黑兰证券交易所指数(TEDPIX)。
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引用次数: 2
期刊
Turkish Journal of Forecasting
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