Geohazard Forecasting in Mining Area Based on Grey Model

2012 ◽  
Vol 524-527 ◽  
pp. 436-440
Author(s):  
Feng Ding ◽  
Long Yi Shao ◽  
Zhao Bin Li ◽  
Feng Lan Zhang
Keyword(s):  
Water Inrush ◽  
Mining Area ◽  
Grey System Theory ◽  
Grey Model ◽  
Ground Subsidence ◽  
Ecological Environment ◽  
Grey System ◽  
Mining Geology ◽  
Ground Crack ◽  
Forecasting Method

This paper studied a forecasting method of geological hazard in loess plateau mining area, by making use of a grey system theory and building grey model, it is expected that in 2018, the loss statistics of mining geology hazard in the area will increase steadily, the loss of water-inrush, slag, ground subsidence, landslide collapse and ground crack will reach relatively 623,480 dollars, 879,346 dollars, 75.833 km2/103km2, 811.295*104m3, 597,761 dollars in 2018. The prediction results provided geological bases for the economic and social sustainable development, ecological environment construction and protection.

Prediction of Technical Reserves Based on Grey Model — GM(1,1): Evidence from Non-life Egyptian Insurance Market

2019 ◽  
Vol 10 (9) ◽  
pp. 852-860
Author(s):  
Mahmoud Elsayed ◽  
◽  
Amr Soliman ◽  
Keyword(s):  
System Theory ◽  
Grey System Theory ◽  
Insurance Market ◽  
Grey Model ◽  
Loss Ratio ◽  
Grey System ◽  
Mathematical Technique ◽  
Supervisory Authority ◽  
Error Ratio ◽  
Using Data

Grey system theory is a mathematical technique used to predict data with known and unknown characteristics. The aim of our research is to forecast the future amount of technical reserves (outstanding claims reserve, loss ratio fluctuations reserve and unearned premiums reserve) up to 2029/2030. This study applies the Grey Model GM(1,1) using data obtained from the Egyptian Financial Supervisory Authority (EFSA) over the period from 2005/2006 to 2015/2016 for non-life Egyptian insurance market. We found that the predicted amounts of outstanding claims reserve and loss ratio fluctuations reserve are highly significant than the unearned premiums reserve according to the value of Posterior Error Ratio (PER).

scholarly journals Utilizing an Adaptive Grey Model for Short-Term Time Series Forecasting: A Case Study of Wafer-Level Packaging

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Che-Jung Chang ◽  
Der-Chiang Li ◽  
Wen-Li Dai ◽  
Chien-Chih Chen
Keyword(s):  
Semiconductor Manufacturing ◽  
Manufacturing System ◽  
Grey System Theory ◽  
Grey Model ◽  
Grey System ◽  
Wafer Level ◽  
Short Term ◽  
Packaging Process ◽  
Wafer Level Packaging

The wafer-level packaging process is an important technology used in semiconductor manufacturing, and how to effectively control this manufacturing system is thus an important issue for packaging firms. One way to aid in this process is to use a forecasting tool. However, the number of observations collected in the early stages of this process is usually too few to use with traditional forecasting techniques, and thus inaccurate results are obtained. One potential solution to this problem is the use of grey system theory, with its feature of small dataset modeling. This study thus uses the AGM(1,1) grey model to solve the problem of forecasting in the pilot run stage of the packaging process. The experimental results show that the grey approach is an appropriate and effective forecasting tool for use with small datasets and that it can be applied to improve the wafer-level packaging process.

Research and Application of Grey Predictive Model Based on Wavelet Analysis

2012 ◽  
Vol 170-173 ◽  
pp. 2912-2916
Author(s):  
Hai Ping Xiao ◽  
Lan Lan Chen ◽  
Yi Qiang Chen ◽  
Zhong Qun Guo
Keyword(s):  
System Theory ◽  
Wavelet Analysis ◽  
Predictive Model ◽  
Wavelet Transformation ◽  
Scientific Basis ◽  
Grey System Theory ◽  
Grey Model ◽  
Grey System ◽  
Predicting Model ◽  
Feasible Method

It is the scientific basis of instructing the project to produce and operate that the deformation is monitored, and the analysis and prediction in constructing and operating of project is one of the important jobs. In order to analyze and predict the deformation of the project more timely and accurately, the paper analyzed and established the feasibility of wavelet-grey predicting model on the basis of the grey system theory in modeling limitations and the characteristics of wavelet transformation. With the comparison of predictive datas in two kinds of models, the results show, the predictive datas of the wavelet-grey model are more accurately than grey model’s, and has achieved good results in prediction of the engineering, is a feasible method.

scholarly journals An Improved Nonequidistant Grey Model Based on Simpson Formula and Its Application

Complexity ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Zhiming Hu ◽  
Chong Liu
Keyword(s):  
Prediction Accuracy ◽  
Prediction Models ◽  
Prediction Performance ◽  
Grey System Theory ◽  
Grey Model ◽  
Grey Prediction ◽  
Grey System ◽  
Proposed Model ◽  
Grey Models ◽  
High Prediction

Grey prediction models have been widely used in various fields of society due to their high prediction accuracy; accordingly, there exists a vast majority of grey models for equidistant sequences; however, limited research is focusing on nonequidistant sequence. The development of nonequidistant grey prediction models is very slow due to their complex modeling mechanism. In order to further expand the grey system theory, a new nonequidistant grey prediction model is established in this paper. To further improve the prediction accuracy of the NEGM (1, 1, t2) model, the background values of the improved nonequidistant grey model are optimized based on Simpson formula, which is abbreviated as INEGM (1, 1, t2). Meanwhile, to verify the validity of the proposed model, this model is applied in two real-world cases in comparison with three other benchmark models, and the modeling results are evaluated through several commonly used indicators. The results of two cases show that the INEGM (1, 1, t2) model has the best prediction performance among these competitive models.

scholarly journals Risk Assessments of Water Inrush from Coal Seam Floor during Deep Mining Using a Data Fusion Approach Based on Grey System Theory

Complexity ◽  
2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
Yaru Guo ◽  
Shuning Dong ◽  
Yonghong Hao ◽  
Zaibin Liu ◽  
Tian-Chyi Jim Yeh ◽  
...  
Keyword(s):  
Coal Seam ◽  
Coal Mining ◽  
Coal Mine ◽  
Drilling Fluid ◽  
Water Pressure ◽  
Water Inrush ◽  
Grey System Theory ◽  
Directional Drilling ◽  
Grey System ◽  
Highly Correlated

With the increase in depth of coal mining, the hydrogeological complexity largely increases and water inrush accidents happen more frequently. For the safety of coal mining, horizontal directional drilling and grouting techniques have been implemented to detect and plug the fractures and conduits that deliver high-pressure groundwater to coal mine. Taking the grouting engineering performed at Xingdong coal mine at 980 m below sea level as an example, we collected the data of grouting quantity, the loss of drilling fluid, gamma value, water temperature, average water absorption, distance between grouting loss points, water pressure on coal seam floor, and aquifuge thickness at 90 boreholes in the mine to conduct grey relational analysis, first. The analysis showed that the grouting quantity was highly correlated with all other factors. Subsequently, grey system evaluation was used to evaluate the risk of water inrush from the coal seam floor. The results of risk analysis illustrated that three water inrushes from Ordovician limestone occurred in mining face 2127, 2125, and 2222 in the study area were all located in the area with a risk score higher than 65. Through grouting, the identified cracks were effectively blocked and waterproof layers beneath the coal seam floors were constructed to reduce the threat of water inrush. By comparing the risk assessment results with three water inrush cases before grouting operation, we found that water inrush areas were consistent with the area of higher risk.

scholarly journals Outlier Detection and Correction for the Deviations of Tooth Profiles of Gears

2013 ◽  
Vol 13 (2) ◽  
pp. 56-62
Author(s):  
Han Lianfu ◽  
Fu Changfeng ◽  
Wang Jun ◽  
Tang Wenyan
Keyword(s):  
System Theory ◽  
Outlier Detection ◽  
Grey System Theory ◽  
Grey Model ◽  
Grey System ◽  
Correction Model ◽  
Preprocessing Method ◽  
Simulation Results ◽  
Modeling Data

To decrease the influence of outlier on the measurement of tooth profiles, this paper proposes a method of outlier detection and correction based on the grey system theory. After studying the characteristics of outliers from the deviations of tooth profiles, this paper proposes a preprocessing method for the modeling data which include abnormal value, and establishes an outlier detection and correction model for the deviations of tooth profiles. Simulation results show that the precision of ONDGM(1,1)(one order and one variable non-homogenous discrete grey model whose outlier is processed by the preprocessing method proposed in this paper) is higher than that of NDGM(1,1)(one order and one variable non-homogenous discrete grey model), and the ONDGM(1,1) is more suitable than the NDGM(1,1) for dealing with the outliers from the deviations of tooth profiles. The experiment results show that the outlier detection and correction model detects and corrects the outliers from the deviations of tooth profiles, and the correction value of the outlier is basically in accordance with the actual deviation. Therefore, the method of outlier detection and correction decreases the influence of outlier and improves the precision in the measurement of tooth profiles.

scholarly journals Influence of chemical composition of windmill palm fibre on crystallinity after alkali peroxide bleaching by grey model

2019 ◽  
Vol 14 ◽  
pp. 155892501988345
Author(s):  
Guicui Chen ◽  
Zhong Wang ◽  
Lifeng Zhang ◽  
Hua Liu ◽  
Guohe Wang ◽  
...  
Keyword(s):  
Chemical Composition ◽  
Least Squares Method ◽  
Lignin Content ◽  
Crystallinity Index ◽  
Grey System Theory ◽  
Grey Model ◽  
Grey System ◽  
Peroxide Bleaching ◽  
Alkaline Peroxide ◽  
Palm Fibre

To study the relationship between the chemical composition and aggregation structure of windmill palm fibres, the Grey System theory, least-squares method and MATLAB® software were used to develop a grey model that relates the crystallinity index to the cellulose, hemicellulose and lignin content of the fibres after alkaline peroxide bleaching. The mean arithmetic error (=0.109) of the grey model (GM (1,4)) indicated that the model could predict the crystallinity of windmill palm fibre based on its chemical composition. Scanning electron microscopy, Fourier transform infrared spectroscopy and Raman microscopy were used to characterize the morphology and chemical composition of the windmill palm fibres before and after alkaline peroxide bleaching. The results indicated that silica, as well as most of the pectin, hemicellulose and lignin, were removed after peroxide bleaching, and thus, the crystallinity index of the peroxide-bleached samples increased. The GM (1,4) provided a reference for studying the influence of the chemical composition of windmill palm fibre on its aggregate structure.

Applications of Grey System Theory to Construction Control of Cable-Stayed Bridge

2010 ◽  
Vol 163-167 ◽  
pp. 2502-2506
Author(s):  
Fang Wen Wu ◽  
Cheng Feng Xue
Keyword(s):  
System Theory ◽  
Control Method ◽  
Grey System Theory ◽  
Grey Model ◽  
Construction Control ◽  
Grey System ◽  
Feedback Information ◽  
Technology System ◽  
Cable Stayed Bridge ◽  
Main Girder

Based on the grey system theory, and combined with the construction features of cable-stayed bridges and construction control method, the paper takes the cable-stayed bridge under construction as the interferential grey technology system with physical prototype and analyzes the random process as grey process in line with grey system theory. The grey model is established by the initialize heights of main girder and cables’ tension as two control inputs of system during the construction of the cable-stayed bridge. Through the feedback information and rectifying the grey model, the initialize heights of main girder and the cable force of next construction stage are predicted in order to control the bridge configuration and cable tension successfully.

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