Grey Correlation Theory Research Articles

Application of Grey Correlation Theory Based on CRITIC Method in Autonomous Vehicles Test and Evaluation

Application of Grey Correlation Theory Based on CRITIC Method in Autonomous Vehicles Test and Evaluation

Earthquake Analyzer using Prediction Commands

Destructive earthquakes usually causes gargantuan casualties. So, to cut back these inimical casualties’ analysis are made to reduce despicable and forlorn impacts which they left upon others to just ponder and become lugubrious. These factors measure the decisive casualties it brings and also earthquake and therefore the development of rational prediction model to casualties become a crucial analysis topic, as a result of quality and cognitive content of gift prediction methodology of price, an additional correct prediction model is mentioned by gray correlation theory and BP neural networks. The earthquake can be analyzed succinct by using various technique mainly predictive commands to marshal all the calculated time and magnitude of a potential earthquake have been the topic of the many studies varied ways are tried mistreatment several input variables like temperature exorable, seismic movements and particularly the variable climatic conditions. The relation between recorded seismal-acoustic information associate degreed occurring an abnormal seismic process (ASP). However, it's obstreperous to predict all parameters the placement, time and magnitude of the earthquake by mistreatment this information. This model description is different from others as with the help of the prediction commands most of the paragons and domains are identified and tend to explore the activity of serious Earthquakes. We use the preemptive data information which is collected around the planet. We retrieved the data to perceive that associate degree earthquake reaches the class of exceeds a grade range of eight on Richter Scale. The two main affected areas are in the field of Data Exploration and Data Mapping. Number of occurrences of an earthquake with different magnitude ranges, severity of an earthquake. Mapping is thereby crucial to identify highly affected areas based on Magnitude and Correlation between depth and magnitude. So, based on the above explorations we have made the following predictions. Predictions Magnitude based on depth. Magnitude based on Latitude and Longitude. Depth based on Latitude and Longitude The primitive algorithm used here are the Machine Learning Algorithm I.e. Linear Regression and KMeans Clustering. Firstly, we have made all the predictions via Linear Regression and made different clusters of the Earthquakes which belong to the same subdivision as that of Magnitude or Depth.

Comprehensive evaluation of process parameters optimization for sheet piercing assisted by magnetic medium based on grey relational analysis

With the promotion of advanced manufacturing concepts such as green, high efficiency and intelligence, the shortboard and development bottleneck of traditional forming technology are increasingly prominent. The traditional forming technology is difficult to meet the actual needs of modern production. Special forming methods have emerged. The piercing process of sheet assisted by magnetic medium is an innovative attempt. However, there are many factors that affect the process, and the multi-field coupling further improves the process complexity, so it is very important to design the experimental scheme scientifically and reasonably. In this paper, through the design of orthogonal experiment, the piercing experiments are carried out under the condition of various process parameters, and then with the help of the grey correlation theory analysis, the relative rollover and the width of the relative bright zone are taken as the evaluation indexes. Through the analysis of range and analysis of variance, to find the key factors affecting the quality of piercing, determine the best combination of process parameters, and verify the accuracy of the results by confirming the test. The results show that: the best process combination scheme is A2B3C2D3. The experiments were carried out according to the recommended optimization scheme, the relative rollover reduced to 1.19%, and the proportion of the width of relative bright area reaches 64.06%. This paper provides scientific guidance for the research and quality improvement of piercing technology assisted by magnetic medium.

Fractal Dimension of Basalt Fiber Reinforced Concrete (BFRC) and Its Correlations to Pore Structure, Strength and Shrinkage.

In this study, we focused on exploring the correlations between the pore surface fractal dimensions and the pore structure parameters, strength and shrinkage properties of basalt fiber-reinforced concrete (BFRC). The pore structure of BFRCs with various fiber contents and fiber lengths was investigated using mercury intrusion porosimetry (MIP) measurements. Through Zhang’s model, the fractal characteristics of BFRCs in the whole pore size range and in different pore size ranges were calculated from the MIP test data. The results showed that the addition of BF increased the total porosity, total pore volume and pore area but decreased the average pore diameter, indicating that BFs refined the pore structure of the concrete. BFRC presented obvious fractal characteristics in the entire pore-size range and individual pore-size ranges; generally, the fractal dimension increased with increasing fiber content. Moreover, correlation analysis suggested that the fractal dimension of BFRC in the whole pore-size range (FD) was closely related to the fractal dimension in the macropore region (Dm) and average pore diameter (APD). The influence of pore structure factors on mechanical strength and shrinkage was studied by grey correlation theory, and the results showed that Dm showed positive correlations with strength and fracture energy, with increasing Dm tending to strengthen and toughen the concrete. An increase in fiber content and length was detrimental to reducing the drying shrinkage strain. In the transition pore region, the fractal dimension (Dt) at diameters ranging from 20 to 50 nm and shrinkage strain exhibited a highly linear relation. These results merit careful consideration in macro-property evaluation by using the pore surface fractal dimension in a specific region instead of the whole region. Finally, grey target theory was applied to evaluate the rank of the mechanical strength and shrinkage of concrete, and the results showed that the overall properties of concrete with a BF length of 18 mm and a BF content of 0.06% ranked the best.

The Relationship between Port Logistics and International Trade Based on VAR Model

Wu, J., 2020. The relationship between port logistics and international trade based on VAR model. In: Yang, Y.; Mi, C.; Zhao, L., and Lam, S. (eds.), Global Topics and New Trends in Coastal Research: Port, Coastal and Ocean Engineering. Journal of Coastal Research, Special Issue No. 103, pp. 601–604. Coconut Creek (Florida), ISSN 0749-0208.This paper puts forward the analysis method of port logistics and international trade based on VAR model. Based on the collection of information resources related to port logistics and foreign trade, the empirical analysis of the relationship between port logistics and international trade is carried out according to the collection results, combined with the grey correlation theory and VAR model. This work analyze the correlation between international trade and port logistics by using grey correlation degree, builds the corresponding VAR model, and analyzes the relationship between the two. It was found that there is and stable equilibrium relationship among trade, port cargo throughput and container throughput. Finally, the paper gives some suggestions on the development of port logistics and international trade from the aspects of strengthening regional cooperation of port logistics, strengthening government work, strengthening industry cooperation and strengthening personnel training of enterprises.

Study on microstructure influence mechanism to mechanical behavior of OGFC asphalt mixture

Microstructure characteristics of OGFC (open graded friction course) asphalt mixture are closely related to the mechanical behavior. To study the microstructure influence mechanism to mechanical behavior of OGFC asphalt mixture, the digital image processing technology is used to process the specimen’s fault images and obtain the microstructure parameters of the OGFC asphalt mixture with different gradation. At the same time, the microstructure influence on mechanical behavior of OGFC asphalt mixture is explored by using the Grey correlation theory based on the experimental results of mechanical performance and the microstructure parameters. The influence of four key sieve passing percentage (1.18, 2.36, 4.75, and 9.5 mm) on the microstructure was discussed by using the Grey correlation theory, and the influence mechanism to mechanical behavior of OGFC asphalt mixture was further revealed. The results show that with the increase of air void content, the total void area, the equivalent pore diameter, and the number of big voids (here, “big” means voids with an area greater than 10 mm2) increase, the length of void and corresponding void area increase synchronously, the drainage performance is enhanced, and the mechanical performance is decreased. With the increase of nominal maximum particle size, the average area of single void, the percentage of number of big voids, and the equivalent diameter increase, and the drainage performance, anti-skidding performance, and mechanical performance of pavement are enhanced. It is considered that the key sieve passing percentage affects the mechanical behavior by influencing the microstructure of asphalt mixtures. The influence degree of microstructure parameters on mechanical behavior and the influence degree of the key sieve passing percentage on microstructure parameters were obtained. The research results have a certain reference value for the optimization of mechanical behavior of OGFC asphalt mixture.

The Fast Potential Evaluation Method of Enhanced Oil Recovery Based on Statistical Analysis

Based on a large number of empirical statistics of tertiary oil recovery technology in China, including polymer flooding, chemical flooding, gas flooding, in situ combustion, steam flooding, ect., 22 key reservoir parameters were filterized. Five levels of quantitative screening criteria were developed for different tertiary oil recovery methods. The mean algorithm for the downward approximation and the grey correlation theory were used in this paper to quickly select the appropriate tertiary oil recovery method for the target blocks, which provides a preferred development method for subsequent potential evaluation. In the rapid analogy evaluation method of tertiary oil recovery potential, the total similarity ratio between the target block and the example block is determined. The target block is matched with the appropriate instance block according to the total similarity ratio value, using 80% as the boundary. The ratio of the geological reserves is used to predict the oil recovery interval, the actual annual injection data, and the economic profit, thus quickly predicting the economic potential of the tertiary oil recovery technology in the target block. Currently, our research team has integrated these two methods into the tertiary oil production potential evaluation software EORSYS3.0. The empirical analysis shows that this method is reasonable and the conclusion is reliable. In addition, the actual enhanced recovery value is within the effective range predicted by the method. The method and results of this paper will provide an important decision-making reference for the application and sustainable development of China Petroleum’s main tertiary oil recovery technology in the next 5–10 years.

Structural design of half hollow rivet for electromagnetic self-piercing riveting process of dissimilar materials

Electromagnetic self-piercing riveting (E-SPR) as a new riveting method is attracting more and more attentions due to its superiority in joining dissimilar materials. In this paper, nine sets of half hollow rivets with different blade angles, inner diameters and leg lengths were designed for E-SPR process. The section quality and mechanical properties of the joints with these rivets for CFRP/Al and steel/Al structures were evaluated, and then the joints with optimal mechanical properties were analyzed by grey correlation theory. The results showed that rivet structures had a significant impact on the section quality of the E-SPR joints, and mechanical properties of the joints with different rivet types performed various. Specifically, in terms of shear load and energy absorption, the rivets with blade angle of 30° and inner diameter of 2.8 mm and the rivets with blade angle of 40° and inner diameter of 2.6 mm were the most suitable for CFRP/Al and steel/Al structure in E-SPR process, respectively. This was because these joints had moderate leg thickness and undercut simultaneously, which provided greater resistance in shear process. This study would provide an available reference for selecting half hollow rivet structures in different applications.

Study on the Movement and Deposition of Particles in Supercritical Water Natural Circulation Based on Grey Correlation Theory

The movement and deposition of particles that occur during their natural circulation in supercritical water exercise an important impact on the safe and stable operation of a supercritical water reactor (SCWR). When supercritical water flows in pipelines, a large number of corrosive particles may be generated due to pipeline corrosion or the purity of the fluid itself. The presence of particulate matter affects the heat transfer efficiency of the pipeline, increasing flow resistance and easily promoting heat transfer deterioration. ANSYS-CFX numerical analysis software was used to simulate the natural circulation loop of supercritical water, and micron particles were added in the initial flow field. The effects of heating power, particle concentration and particle diameter on particle deposition were obtained. Through this analysis, it can be concluded that the heating of the pipeline has a certain inhibitory effect on the deposition of particles. The rise in both initial particle concentration and particle diameter serve to reinforce the deposition of particles in the heating section. Depending on the degree of influence, the contributory parameters to particle deposition include particle diameter, particle concentration and heating power in turn.

Reliability analysis of tractor multi‐way valves based on the improved weighted grey relational method

In order to analyse the influence of different performance indexes on the working reliability of a tractor multi-way valve. The grey correlation theory is introduced into the reliability analysis of multi-way valves. Combined with the multi-way valve failure mode, the reliability index is proposed, and then a grey relational model and the reliability evaluation sequence of multi-way valves are established. The reliability of multi-way valve is analysed by traditional grey relational analysis and improved weighted grey correlation analysis, respectively. Although both methods produced the same optimal prototype, the dynamic identification coefficient introduced by the latter can effectively suppress the influence of singular values on the correlation sequence in the prototype sequence. The analysis process is simplified, and the accuracy of calculation is improved. Meanwhile, the identification degree of the sequence of the prototype is increased. In addition, the improved weighted grey relational analysis method uses the entropy weight method to assign weight coefficients. This method can reflect the influence degree of different sequence points on the overall correlation degree objectively and improve the reliability of the analysis results. Finally, the correctness of the optimal prototype is verified by comparing the experimental data. The reliability evaluation standard of the tractor multi-way valve is obtained.

A Critical Review: Shape Optimization of Welded Plate Heat Exchangers based on Grey Correlation Theory

Shape optimization and heat analysis of heat exchangers are important areas of research that are seeking attention among scholars from thermal engineering and related fields since decades. In the 123rd volume of Applied Thermal Engineering a paper entitled “Shape optimization of welded plate heat exchangers based on grey correlation theory” was published. The current study exposed not only the inappropriate execution of Deng’s Grey Relational Analysis model, which is referred to as grey correlational theory in that publication, but also some miscalculations. Problem with the design of the experiment and other issues have also been reported. These mistakes, along with the fact that some crucial data was missing from that publication, make the reproducibility of the certain results in that publication problematic, and are highlighted in the current study. The study is particularly important for industrial heat analysts and the researchers interested in multi-objective optimization through grey methods.

Spatiotemporal characteristics of earthquake disaster losses in China from 1993 to 2016

On the basis of data obtained from China Earthquake Administration and China National Statistics Bureau, this paper focuses on the earthquake disaster loss characteristics in 31 provinces or municipalities of China from 1993 to 2016. The trends of direct economic losses, casualties and affected population are also analyzed by constructing two relative earthquake loss indexes (losses/GDP and losses/E) and employing gray correlation theory. Results show that during the 24 years, without taking Wenchuan Ms8.0 earthquake into account, the direct economic losses exhibit a significant increasing trend while losses/GDP also increases but is not significant. Meanwhile, the injuries and affected population both witness a decline trend but the fatalities show the opposite. According to the correlational degree of each year, 8 years (1995, 1996, 1998, 2003, 2008, 2010, 2013 and 2014) suffered losses of equal or above moderate grade. Regionally, the western China suffered the most accumulative direct economic losses and losses/GDP. However, the ranking results of losses/E demonstrate that the central China is the most vulnerable when confronting with the same earthquake. Specifically, Sichuan and Yunnan suffered losses of extra-large grade, Qinghai of large grade and Tibet, Xinjiang and Guangdong of moderate grade. These discoveries are helpful for earthquake mitigation and preparedness as well as earthquake loss evaluation in China.

A grey correlation based supply–demand matching of machine tools with multiple quality factors in cloud manufacturing environment

Machine tool is one of the most important manufacturing resources for manufacturing enterprises. Taking into account the machine tool’s common characteristics of decentralization and heterogeneity in cloud manufacturing (CMfg) environment, it is difficult to precisely find an appropriate machine tool from massive manufacturing service candidates to a customized manufacturing demand in CMfg. This paper proposes a multi-quality model for characterizing a manufacturing demand and a capability model for describing a manufacturing cloud service supported by machine tools, and constructs a mapping mechanism between the two proposed models. Based on the grey correlation theory, a machine tool supply–demand matching method is put forward. Finally, a case study is conducted to validate the feasibility of the proposed method.

Modeling and experimental study of multiple factors on mechanical strength of iron sand modified cement mortars

To figure out how multiple factors affect iron sand modified cement mortar (ISCM)’s mechanical properties, the influence of the water-cement ratio, sand-cement ratio, river sand-iron sand ratio, density, and age on its mechanical properties were analyzed by compressive and flexural tests. Then, the influence degree of multiple factors on mechanical strength is studied by gray correlation theory. The results showed that the water-cement ratio has the most significant influence on mechanical strength. Afterwards, gray target theory is applied to evaluate the mechanical strength rank of three kinds of ISCM. The results showed the overall mechanical properties of natural iron sand modified cement mortar rank the best. Finally, new prediction models for mortars’ compressive and flexural strengths are systematically proposed and compared with two existing models. The results show that the proposed models have more agreements with experimental values.

Isomorphism problem of China’s marine industries: Analysis based on the gray correlation theory

This paper investigates the correlation across China’s marine industries and the relationship between marine and land industries in coastal provinces using the Gray Correlation Theory. Our results show an increasing similarity of marine industry structures, a low allocation efficiency of marine resources as well as growing but homogeneous competition between regions. To avoid the problem of “isomorphism” in marine industry, we should focus on policy measures such as optimizing the overall spatial distribution of marine economy, promoting the development of the new marine industry, strengthening the correlation between marine and land industries, building a complementary development pattern for marine economy, expanding new areas for industrial development and fostering new economic growth points.

Weight Analysis of Influence Factors and Potential Evaluation Method for Chemical Combination Flooding

In this paper, the weight coefficient of influencing factors for chemical combination flooding is determined by using grey correlation theory. A calculation method for comprehensive evaluation score of chemical combination flooding is established. The influence factor grading and weight grading are combined in this method. By collecting and analysing chemical combination flooding field tests, a prediction method for chemical combination flooding is established by the exponential regression. It reflects the relationship between EOR of the chemical combination flooding and the comprehensive evaluation score. The new method is applied in 6 different reservoirs to evaluate the effect of chemical flooding. The new method determines the weight coefficient of influence factors for chemical combination flooding. It can quickly predict EOR factor of chemical flooding to provide a basis for chemical flooding planning in the field.

The Risk Assessment of Tunnels Based on Grey Correlation and Entropy Weight Method

In the process of tunnel construction, many kinds of geological disasters are frequently occur. Among them, tunnel collapse is one of the most serious geological disasters. Seven controlling factors were determined by analyzing 76 large or medium tunnel collapses in China. By means of synthesizing all kind of index parameters, grey relational coefficients were calculated based on grey correlation theory. Entropy weight method was used to compute the weight coefficients. And a comprehensive risk evaluation model of tunnel collapse was established based on entropy weight and grey relational degree. The paper gives the correctional coefficients depending on rainfall conditions during construction of the tunnel. At last the collapse risk level of tunnels was obtained. Based on the actual project cases of risk assessment, the results indicated that the comprehensive risk evaluation model of tunnel collapse was scientific and reasonable. And it was shown that the method was easy to master and has a great significance on engineering practice.

Selection of an evaluation index for water ecological civilizations of water-shortage cities based on the grey rough set

According to the characteristics and existing problems of water ecological civilization of water-shortage cities, the evaluation index system of water ecological civilization was established using a grey rough set. From six aspects of water resources, water security, water environment, water ecology, water culture and water management, this study established the prime frame of the evaluation system, including 28 items, and used rough set theory to undertake optimal selection of the index system. Grey correlation theory then was used for weightings in order that the integrated evaluation index system for water ecology civilization of water-shortage cities could be constituted. Xi’an City was taken as an example, for which the results showed that 20 evaluation indexes could be obtained after optimal selection of the preliminary framework of evaluation index. The most influential indices were the water-resource category index and water environment category index. The leakage rate of the public water supply pipe network, as well as the disposal, treatment and usage rate of polluted water, urban water surface area ratio, the water quality of the main rivers, and so on also are important. It was demonstrated that the evaluation index could provide an objectively reflection of regional features and key points for the development of water ecology civilization for cities with scarce water resources. It is considered that the application example has universal applicability.

The Prediction Model of Cold Recycled Materials Mechanical Properties based on the Grey Neural Network

This paper aims at predicting the mechanical performance of emulsified asphalt cold recycled material to improve road performance. Measured the data of cold recycled materials mechanical properties under different pavement structures, and using Genetic Algorithm (GA) to optimize the grey neural network model for data analysis and forecast, analyze cold recycled materials mechanical properties influence factors (thickness and modulus of cold regeneration layer, thickness and modulus of the cement stable macadam mixture, and modulus of soil base) by using Grey Correlation theory. Results confirmed that the outputs of Grey Neural Network (GNN) showed that the errors between predicted results and measured results were lower than 6.281%, which means can predict the emulsified asphalt cold recycled materials mechanical properties effectively and quantify the cold regeneration mechanical properties under different factor prediction analysis. It shows that modulus of cement stabilized macadam has great influence on the mechanical properties of cold regeneration materials by using Grey Correlation theory, this study has great significance to improve the road performance cold recycled mixture and chose pavement structure better.

Shape optimization of welded plate heat exchangers based on grey correlation theory

This paper focuses on shape optimization and heat transfer analysis of a Welded Plate Heat Exchanger (WPHE) with straight gas channels and corrugated water channels. Three influential factors (long axis, short axis and plate spacing) were selected as the initial variables to carry out CFD (Computational Fluid Dynamics) simulation. The influences of various factors on heat transfer characteristics were analyzed using the grey correlation theory, then the optimal parameters of WPHE were discovered by increasing the data density for further study. To verify the correctness of the results, a test platform was built based on the optimal parameters. The error of the two study methods was less than 10%, compared with the CFD simulation results.