scholarly journals Analysis and Prediction of Influencing Parameters on the Coal Classification Performance of a Novel Three Products Hydrocyclone Screen (TPHS) Based on Grey System Theory

Processes ◽  
2020 ◽  
Vol 8 (8) ◽  
pp. 974
Author(s):  
Chuanzhen Wang ◽  
Xiaolu Sun ◽  
Liang Shen ◽  
Guanghui Wang
Keyword(s):  
Performance Evaluation ◽  
Effective Means ◽  
Grey System Theory ◽  
Small Samples ◽  
Grey Theory ◽  
Aperture Size ◽  
Grey System ◽  
Feed Concentration ◽  
Feed Pressure ◽  
Vortex Finder

A novel hydrocyclone including a cylindrical screen embedded in a conventional hydrocyclone (CH), named three products hydrocyclone screen (TPHS), has been successfully designed. In TPHS, the combination of centrifugal classification and screening was employed to separate particles. In this paper, Grey theory, as an effective means to the laws of both complex and uncertainty system’s behavior with small samples, was used to investigate the operational (feed concentration and feed pressure) and structural (aperture size, spigot diameter, and vortex finder diameter) parameters on performance evaluation Hancock classification efficiency (HE), imperfection (I), and cut size (d50c). The experiments of coal sample (0–1 mm) show that TPHS with coarser particles in underflow exhibited the absent “fish-hook”. The closeness calculated using the Grey System algorithm indicates that the performance of TPHS was closely related to the operation and structure parameters. Further, the order of grey incidence degree between different parameters and HE (or I or d50c) is the spigot diameter and aperture size with the highest value, the feed pressure and vortex finder diameter with the middle value, and the feed concentration with the lowest value. The prediction using the GM(1, N) algorithm implies that the dynamic prediction model for the performance evaluation can be created depending on the operation, structure and previous performance value. The mean relative errors between the predicted and actual HE, I, and d50 were 2.84%, 5.83%, and 3.57%, respectively, which exhibit the accurate prediction.

Assessment of airport performance using the grey theory method

2017 ◽  
Vol 7 (3) ◽  
pp. 426-436 ◽  
Author(s):  
Mohamed Ibrahim Eshtaiwi ◽  
Ibrahim A. Badi ◽  
Ali M. Abdulshahed ◽  
Turan Erman Erkan
Keyword(s):  
System Theory ◽  
Performance Evaluation ◽  
Service Quality ◽  
Design Methodology ◽  
Grey System Theory ◽  
Grey Theory ◽  
Theory Method ◽  
Grey System ◽  
Content Type ◽  
Overall Performance

Purpose Performance evaluation of airports or any other organisation is paramount for improving performance. The purpose of this paper is to evaluate and compare the performance of the three international airports in Libya (MJI, MRA, and LAQ airports) by considering five aspects of performance. Design/methodology/approach The considered aspects are airport service quality, airport operations, airport economy, safety and security, and environmental. The paper uses the grey system theory to assess these airports by summarizing the opinions of experts. Findings The finding of this study provides directions of the evaluated airports to take the correct actions to improve overall performance. Originality/value No literature has been found till date is to evaluate and compare the performance of the international airports in Libya.

Application of Grey System Theory in the Dynamic Monitoring of Bridge

2014 ◽  
Vol 501-504 ◽  
pp. 829-833
Author(s):  
Cheng Xin Yu ◽  
Zheng Wen Yu ◽  
Yong Qian Zhao ◽  
Jia Dong Zhang
Keyword(s):  
Dynamic Deformation ◽  
Active Role ◽  
Theory Model ◽  
Grey System Theory ◽  
Dynamic Monitoring ◽  
Grey Theory ◽  
Observation Error ◽  
Bridge Structure ◽  
Grey System ◽  
Safety And Reliability

It has great significance to ensure the safety of bridge structure by using information technology to monitor the bridge dynamic deformation and find out problems in time, besides, it is more effective to make analysis of the bridge by using grey theory model. The combination of the two methods could avoid the observation error, and play an active role in improving the safety and reliability of bridge.

Study on the Model of Construction Accident Forecast Based on Grey-Markov Theory

2012 ◽  
Vol 433-440 ◽  
pp. 2874-2880 ◽  
Author(s):  
Guo Zhong Huang ◽  
Hui Liu ◽  
Can Sheng Yang ◽  
Zhong Guang Wu
Keyword(s):  
System Theory ◽  
Forecast Model ◽  
Development Trend ◽  
Grey System Theory ◽  
Small Data ◽  
Grey Theory ◽  
Grey System ◽  
Stochastic Fluctuation ◽  
Construction Accidents ◽  
The Development Trend

According to the grey system theory and markov principle, the fitting accuracy index is stochastic and fluctuant when time series datadevelopment trend is fitted through the grey theory; but the markov principle is suitable for processing the system with great stochastic fluctuation; therefore, a forecast model is put forward which is in accordance with the characteristics of construction accidents’ statistical data and is based on the grey system theory and markov principle. The model is suitable for the dynamic forecasting process featured by short forecasting time, small data quality and great stochastic fluctuation. The conclusion about the development trend of construction accidents with the model based on the grey-markov theory is more ideal compared with the grey model. The application example shows that the forecasting conclusion based on grey-markov theory is more accurate and more reliable. So the model is available enough to forecast the construction accidents.

Grey Theory Approach to Sequential Turbocharged Diesel Engine

2007 ◽  
Vol 10-12 ◽  
pp. 934-938
Author(s):  
Peng Qi Zhang ◽  
Jian Wei Du ◽  
Yin Yan Wang
Keyword(s):  
Diesel Engine ◽  
Uncertain System ◽  
Forecast Model ◽  
Grey System Theory ◽  
Grey Theory ◽  
Boost Pressure ◽  
Theory Approach ◽  
Good Precision ◽  
Grey System ◽  
Turbocharged Diesel Engine

In order to ensure diesel engine operating reliably, need to forecast the performance parameters of diesel engine. Grey system theory, a method to research poor information and uncertain system, was approached to sequential turbocharged diesel engine. Grey forecast model of boost pressure of sequential turbocharged diesel engine was established. The precision of the forecast model was inspected by grey relation analysis, it is proved that the model has a good precision and is suitable to forecasting boost pressure. The relatively error of the forecast result is 2.5%. And it establishes the base for forecasting control and failure prediction of diesel engine sequential turbocharging system.

scholarly journals The Development of a Hybrid Wavelet-ARIMA-LSTM Model for Precipitation Amounts and Drought Analysis

Atmosphere ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 74
Author(s):  
Xianghua Wu ◽  
Jieqin Zhou ◽  
Huaying Yu ◽  
Duanyang Liu ◽  
Kang Xie ◽  
...  
Keyword(s):  
Time Series ◽  
Short Term Memory ◽  
Moving Average ◽  
Grey System Theory ◽  
Small Sample ◽  
Annual Precipitation ◽  
Drought Event ◽  
Monthly Precipitation ◽  
Grey Theory ◽  
Grey System

Investigation of quantitative predictions of precipitation amounts and forecasts of drought events are conducive to facilitating early drought warnings. However, there has been limited research into or modern statistical analyses of precipitation and drought over Northeast China, one of the most important grain production regions. Therefore, a case study at three meteorological sites which represent three different climate types was explored, and we used time series analysis of monthly precipitation and the grey theory methods for annual precipitation during 1967–2017. Wavelet transformation (WT), autoregressive integrated moving average (ARIMA) and long short-term memory (LSTM) methods were utilized to depict the time series, and a new hybrid model wavelet-ARIMA-LSTM (W-AL) of monthly precipitation time series was developed. In addition, GM (1, 1) and DGM (1, 1) of the China Z-Index (CZI) based on annual precipitation were introduced to forecast drought events, because grey system theory specializes in a small sample and results in poor information. The results revealed that (1) W-AL exhibited higher prediction accuracy in monthly precipitation forecasting than ARIMA and LSTM; (2) CZI values calculated through annual precipitation suggested that more slight drought events occurred in Changchun while moderate drought occurred more frequently in Linjiang and Qian Gorlos; (3) GM (1, 1) performed better than DGM (1, 1) in drought event forecasting.

An Error Modified Grey Theory for Forecasting International Oil Price

2013 ◽  
Vol 380-384 ◽  
pp. 1525-1528 ◽  
Author(s):  
Xiao Li Yang ◽  
Qiong He ◽  
Fen Yang
Keyword(s):  
System Theory ◽  
Crude Oil ◽  
Prediction Accuracy ◽  
Grey System Theory ◽  
Amplitude Fluctuation ◽  
Oil Price ◽  
Grey Theory ◽  
Grey System ◽  
Crude Oil Price ◽  
A Company

The international oil price has fluctuated in a relatively large amplitude fluctuation in recent years, so the accurately prediction of the crude oil price is very important for a country and a company. There are a lot of means to forecast the trend of things, but if the problem is uncertain and the information is lacking, grey system theory (GST) is an efficient method. In this work we forecast the international crude oil price by using the grey system theory and creating a MATLBA program to achieve it. In order to improve the prediction accuracy, we modified the prediction results.

Research on Factors Influence of Vegetation Slope Protection Based on Grey Incidence Analysis Theory

2012 ◽  
Vol 226-228 ◽  
pp. 1382-1385
Author(s):  
Feng Chen ◽  
Xiao Bo Xiong ◽  
Zhi Ming Zhai ◽  
Cheng Gu ◽  
Xin Bo Zhang
Keyword(s):  
System Theory ◽  
Grey System Theory ◽  
Good Prospect ◽  
Grey Theory ◽  
Grey System ◽  
Grey Incidence Analysis ◽  
The Stability ◽  
Incidence Analysis ◽  
The Impact ◽  
Bio Engineering

Vegetation Slope Protection Engineering was affected by several factors, and has become the focus of the geotechnical engineering. The stability of the vegetation slope must be controlled rigorous according to the surrounding environment condition and safety level of the slope in highway. According to the Grey Incidence Analysis (GIA) method of grey system theory, a new grey theory model is applied in analyzing of the characteristics of Eco-engineering protected by roots of vegetation, to attain the correlation coefficient affected by extent of the factors. After analysis of several practical Bio-engineering examples, to attain the most influencing factors of the stability of vegetation slope are the density of roots (ρ), the length of roots (L), the diameter of roots (D), the weight of soil (γ), the anti-pulling force of roots (P), internal friction angle (φ), cohesive strength(c) and the shear strength of the soil (τ). The role of factors is classified in order to define the extent of the impact and provide guidance for construction and design of Eco-engineering. After analyzing the data collected from the field and several classicistic documents, utilized Grey Incidence Analysis method to make prediction in order to guarantee the slope safety. It shows that the grey system theory can be effectively and practically adopted in the slope stability analysis of vegetation slope in expressway and that has a good prospect.

A Grey Model for Predicting Water and Oil Production Rate

2013 ◽  
Vol 734-737 ◽  
pp. 1135-1137
Author(s):  
Kao Ping Song ◽  
Jian Wen Tao ◽  
Ji Cheng Zhang
Keyword(s):  
Oil Production ◽  
Grey System Theory ◽  
Data Series ◽  
Grey Theory ◽  
Grey System ◽  
Production Water ◽  
Grey Number ◽  
Single Data ◽  
Water Cut ◽  
General Range

Grey system theory is a kind of method and system that contains something known and unknown. A completely definitive number is called a white number, while for one that does not have a definite value but a general range is called a grey number, whose greatest attribute is forecasting single data series. The grey theory was applied to predict the development index of X-L oilfield, including oil production, water production and water cut. The result is of very good accuracy.

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