scholarly journals Evaluation on Ecological City assessment mechanism construction based on gray correlation theory

2016 ◽  
Author(s):  
Xiangjun Pu
Keyword(s):  
Correlation Theory ◽  
Gray Correlation

A Research of Portable GPS Design

2014 ◽  
Vol 513-517 ◽  
pp. 4302-4308
Author(s):  
Jian Xin Cheng ◽  
Mei Yu Zhou ◽  
Miao Miao Zhang ◽  
Jue Wu
Keyword(s):  
Hierarchical Clustering ◽  
Incidence Matrix ◽  
Kansei Engineering ◽  
Clustering Method ◽  
Design Elements ◽  
Correlation Theory ◽  
Gray Correlation

This paper is based on Kansei engineering theories and methods combines with hierarchical clustering and gray correlation theory. The information of consumers perceptual demands for the product is obtained, and after that the existing products are collected and sifted, and their design elements are analyzed. The information of consumers perceptual demands is classified and extracted by using systematic clustering method perceptual demands. Two incidence matrixes have been created by investigating consumers perceptual demands. Finally, we get the incidence matrix between consumers perceptual demands and existing product samples. Also, analysis of correlation between each sample and the perceptual demands of consumers was made by using gray correlation theory.

Loader Fatigue Correlation Analysis on the Lab Conditions and Theoretical Calculation

2014 ◽  
Vol 889-890 ◽  
pp. 637-644
Author(s):  
Hao Jing Lin ◽  
Shao Fen Lin
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Correlation Analysis ◽  
Theoretical Calculation ◽  
Laboratory Condition ◽  
Fatigue Test ◽  
Fatigue Failure ◽  
Counting Method ◽  
Correlation Theory ◽  
Gray Correlation

This article proposes whether fatigue failure is same under laboratory condition and theoretical calculation based on loader fatigue test. Analyzing and calculating the loading cycles, then counting by counting method, then obtain the S-N curve of loader by finite element method. Combines gray correlation theory to analyses the correlation of fatigue failure between laboratory condition and theoretical calculation.

Evaluation of Moisture Based on Gray Correlation Theory

2010 ◽  
Vol 129-131 ◽  
pp. 597-601
Author(s):  
Wei Zheng ◽  
Tu Jin Hu ◽  
Zi Li Yan
Keyword(s):  
System Theory ◽  
Confidence Interval ◽  
Mix Design ◽  
Batch Size ◽  
Gray System Theory ◽  
Gray System ◽  
Correlation Theory ◽  
Concrete Quality ◽  
Gray Correlation ◽  
Microwave Sensors

The moisture of the sand in concrete industry is important for concrete quality. There are some different methods to measure the moisture in the sand. The microwave sensors are commonly used. The mix design or batch size frequently changes in some case. The gray correlation theory of gray system theory was applied in slump evaluation where the gray correlation coefficient and gray distance measurement were made use of in calculation estimating slump or the moisture of the sand. Then, the gray confidence interval of estimated value of moisture of the sand was calculated based on gray confidence level.

scholarly journals Analysis of Microscopic Main Controlling Factors for Occurrence of Movable Fluid in Tight Sandstone Gas Reservoirs Based on Improved Grey Correlation Theory

2021 ◽  
Vol 2021 ◽  
pp. 1-8
Author(s):  
Xuefei Lu ◽  
Fengjuan Dong ◽  
Xiaolong Wei ◽  
PengTao Wang ◽  
Na Liu ◽  
...  
Keyword(s):  
Physical Properties ◽  
Physical Property ◽  
Type I ◽  
Type Ii ◽  
Gas Reservoirs ◽  
Tight Sandstone ◽  
Throat Radius ◽  
Gas Field ◽  
Correlation Theory ◽  
Gray Correlation

Tight sandstone reservoirs have the characteristics of poor physical properties, fine pore throats, and strong microheterogeneity compared with conventional reservoirs, which results in complicated movable fluid occurrence laws and difficult mining. Taking the tight sandstone gas reservoir of He 8 formation in Sulige gas field as an example, based on physical property test analysis, constant velocity mercury injection, and nuclear magnetic resonance experiments, an optimized gray correlation calculation model is established by improved gray correlation theory, which quantitatively characterizes the influence of microscopic pore structure parameters of different types of tight sandstone gas reservoirs on the occurrence of movable fluids, and the main controlling microgeological factors for the occurrence of movable fluid in tight sandstone gas reservoirs with close/similar physical properties are selected. The results show that the occurrence of movable fluid in Type I reservoirs is mainly affected by the effective pore-throat radius ratio, the saturation of mercury in the total throat, and the effective pore radius, and the occurrence of movable fluid in Type II reservoirs is mainly affected by the effective throat radius per unit volume and total throat mercury saturation and mainstream throat radius. Moreover, the occurrence state of movable fluids in Type II reservoirs is controlled by the throat radius stronger than that of Type I reservoirs. It has important guiding significance for the efficient development of tight sandstone gas reservoirs.

scholarly journals A reservoir quality evaluation approach for tight sandstone reservoirs based on the gray correlation algorithm: A case study of the Chang 6 layer in the W area of the as oilfield, Ordos Basin

2021 ◽  
pp. 014459872199851
Author(s):  
Yuyang Liu ◽  
Xiaowei Zhang ◽  
Junfeng Shi ◽  
Wei Guo ◽  
Lixia Kang ◽  
...  
Keyword(s):  
Quality Evaluation ◽  
Comprehensive Evaluation ◽  
Ordos Basin ◽  
Reservoir Quality ◽  
Pore Throat ◽  
Tight Sandstone ◽  
Evaluation Approach ◽  
Correlation Algorithm ◽  
Gray Correlation ◽  
Sandstone Reservoir

As an important type of unconventional hydrocarbon, tight sandstone oil has great present and future resource potential. Reservoir quality evaluation is the basis of tight sandstone oil development. A comprehensive evaluation approach based on the gray correlation algorithm is established to effectively assess tight sandstone reservoir quality. Seven tight sandstone samples from the Chang 6 reservoir in the W area of the AS oilfield in the Ordos Basin are employed. First, the petrological and physical characteristics of the study area reservoir are briefly discussed through thin section observations, electron microscopy analysis, core physical property tests, and whole-rock and clay mineral content experiments. Second, the pore type, throat type and pore and throat combination characteristics are described from casting thin sections and scanning electron microscopy. Third, high-pressure mercury injection and nitrogen adsorption experiments are optimized to evaluate the characteristic parameters of pore throat distribution, micro- and nanopore throat frequency, permeability contribution and volume continuous distribution characteristics to quantitatively characterize the reservoir micro- and nanopores and throats. Then, the effective pore throat frequency specific gravity parameter of movable oil and the irreducible oil pore throat volume specific gravity parameter are introduced and combined with the reservoir physical properties, multipoint Brunauer-Emmett-Teller (BET) specific surface area, displacement pressure, maximum mercury saturation and mercury withdrawal efficiency parameters as the basic parameters for evaluation of tight sandstone reservoir quality. Finally, the weight coefficient of each parameter is calculated by the gray correlation method, and a reservoir comprehensive evaluation indicator (RCEI) is designed. The results show that the study area is dominated by types II and III tight sandstone reservoirs. In addition, the research method in this paper can be further extended to the evaluation of shale gas and other unconventional reservoirs after appropriate modification.

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