Optimization of short-circuit transition parameters of Q235B steel GMAW based on orthogonal gray relational analysis

In gas metal arc welding(GMAW)process,the short-circuit transition was the most typical transition observed in molten metal droplets.This paper used orthogonal tests to explore the coupling effect law of welding process parameters on the quality of weld forming under short-circuit transition,the design of 3 factors and 3 levels of a total of 9 groups of orthogonal tests,welding current,welding voltage,welding speed as input parameters:effective area ratio,humps,actual linear power density,aspect ratio,Vickers hardness as output paramet-ers(response targets).Using range analysis and trend charts,we can visually depict the relationship between input parameters and a single output parameter,ultimately determining the optimal process parameters that impact the single output index.Then combined with gray the-ory to transform the three response targets into a single gray relational grade(GRG)for analysis,the optimal combination of the weld mor-phology parameters as follows:welding current 100 A,welding voltage 25 V,welding speed 30 cm/min.Finally,validation experiments were conducted,and the results showed that the error between the gray relational grade and the predicted value was 2.74%.It was observed that the effective area ratio of the response target significantly improved,validating the reliability of the orthogonal gray relational method.

A Hybrid Optimization Approach of Single Point Incremental Sheet Forming of AISI 316L Stainless Steel Using Grey Relation Analysis Coupled with Principal Component Analysiss

We investigated the parametric optimization on incremental sheet forming of stainless steel using Grey Relational Analysis(GRA) coupled with Principal Component Analysis(PCA). AISI 316L stainless steel sheets were used to develop double wall angle pyramid with aid of tungsten carbide tool. GRA coupled with PCA was used to plan the experiment conditions. Control factors such as Tool Diameter(TD), Step Depth(SD), Bottom Wall Angle(BWA), Feed Rate(FR) and Spindle Speed(SS) on Top Wall Angle(TWA) and Top Wall Angle Surface Roughness(TWASR) have been studied. Wall angle increases with increasing tool diameter due to large contact area between tool and workpiece. As the step depth, feed rate and spindle speed increase,TWASR decreases with increasing tool diameter. As the step depth increasing, the hydrostatic stress is raised causing severe cracks in the deformed surface. Hence it was concluded that the proposed hybrid method was suitable for optimizing the factors and response.

Isogeometric Analysis of Hyperelastic Material Characteristics for Calcified Aortic Valve

This study explores the implementation of computed tomography(CT)reconstruction and simulation techniques for patient-specific valves,aiming to dissect the mechanical attributes of calcified valves within transcatheter heart valve replacement(TAVR)procedures.In order to facilitate this exploration,it derives pertinent formulas for 3D multi-material isogeometric hyperelastic analysis based on Hounsfield unit(HU)values,thereby unlocking foundational capabilities for isogeometric analysis in calcified aortic valves.A series of uniaxial and biaxial tensile tests is executed to obtain an accurate constitutive model for calcified active valves.To mitigate discretization errors,methodologies for reconstructing volumetric parametric models,integrating both geometric and material attributes,are introduced.Applying these analytical formulas,constitutive models,and precise analytical models to isogeometric analyses of calcified valves,the research ascertains their close alignment with experimental results through the close fit in displacement-stress curves,compellingly validating the accuracy and reliability of the method.This study presents a step-by-step approach to analyzing themechanical characteristics of patient-specific valves obtained fromCT images,holding significant clinical implications and assisting in the selection of treatment strategies and surgical intervention approaches in TAVR procedures.

Analysis on the Climate Characteristics of Relative Humidity in Recent 40 Years in Urumqi City

By using the daily average relative humidity data in Urumqi during 1961-2000,the basic climate characteristics and the variation trend of relative humidity in Urumqi in recent 40 years were analyzed.The results showed that the yearly average relative humidity in Urumqi was 57.5%.The relative humidity in winter was 77.5% which was the biggest all the year round,and the relative humidity in summer was 41.2% which was the smallest.The relative humidity in spring,summer,autumn,winter and the yearly relative humidity all displayed the increase trend.The yearly mean relative humidity had the periods of mainly 2,3-4 and quasi-7 years.The periodic oscillation of quasi-7 years was the strongest.

New seismic attribute:Fractal scaling exponent based on gray detrended fluctuation analysis

Seismic attributes have been widely used in oil and gas exploration and development. However, owing to the complexity of seismic wave propagation in subsurface media, the limitations of the seismic data acquisition system, and noise interference, seismic attributes for seismic data interpretation have uncertainties. Especially, the antinoise ability of seismic attributes directly affects the reliability of seismic interpretations. Gray system theory is used in time series to minimize data randomness and increase data regularity. Detrended fluctuation analysis （DFA） can effectively reduce extrinsic data tendencies. In this study, by combining gray system theory and DFA, we propose a new method called gray detrended fluctuation analysis （GDFA） for calculating the fractal scaling exponent. We consider nonlinear time series generated by the Weierstrass function and add random noise to actual seismic data. Moreover, we discuss the antinoise ability of the fractal scaling exponent based on GDFA. The results suggest that the fractal scaling exponent calculated using the proposed method has good antinoise ability. We apply the proposed method to 3D poststack migration seismic data from southern China and compare fractal scaling exponents calculated using DFA and GDFA. The results suggest that the use of the GDFA-calculated fractal scaling exponent as a seismic attribute can match the known distribution of sedimentary facies.

Applications of gray relational analysis in gastroenterology

ABM: To introduce the basic methods of gray relational analysis (GRA) and to illustrate its applications in gastroenterology. METHODS: With the essential formulae of GRA and several typically practical examples, the procedure of GRA was introduced. Examples were drawn from the gastroenterological studies. Thus the trait of GRA could be demonstrated. RESULTS: The superiority of GRA in gastroenterological study was proved by the examples. CONCLUSION: GRA can be applied mechanically or flexibly in gastroenterology.

Application of gray correlation analysis and artificial neural network in rock mass blasting

Studied forecasting and controlling the blasting fragmentation by using artifi- cial neural network for multi-ingredients. At the same time, according to the characteris- tic of multi-parameters input to network model, the gray correlation theory was employed to find out key factors, which can not only save time of computation and parameters in- put, but improve the stability of the model.

Zero drift and solid Earth tide extracted from relative gravimetric data with principal component analysis

Zero drift and solid Earth tide corrections to static relative gravirnetric data cannot be ignored. In this paper, a new principal component analysis （PCA） algorithm is presented to extract the zero drift and the solid Earth tide, as signals, from static relative gravimetric data assuming that the components contained in the relative gravimetric data are uncorrelated. Static relative gravity observations from Aug. 15 to Aug. 23, 2014 are used as statistical variables to separate the signal and noise with PCA to obtain desired signals. The results of the linear drift extracted by PCA are consistent with those calculated by the least squares linear fitting, and the differences only reach to 10-2μGal/day order of magnitude. Furthermore, PCA is used to estimate the solid Earth tide from the relative gravimetric data corrected by the zero drift. The statistical results are consistent with the results derived from the solid Earth tide correction provided by the internal software of the CG-5 gravimeter （SCINTREX Limited Ontario Canada）. The statistical results of the differences between the two methods are both less than 8 ,Gal, and the RMSs for 9 days are all less than 5 μGal.

Comprehensive Evaluation of Flood and Flood in the Yellow River Basin Based on Gray Correlation Analysis

Due to the concentrated rainfall and serious soil erosion in July and August in the Yellow River Basin, the flood discharge is not timely leading to serious floods. Therefore, a reasonable assessment of the flood-affected areas, advance arrangements for the deployment of the Yellow River basin flood disaster prevention and control plays a decisive role. For this purpose, this paper proposes a level assessment method based on the flood which analyzes three factors related to flooding disaster (disaster impact range, social index, and property index) through the gray correlation analysis method, to evaluate the level of flood disaster. Different from the traditional assessment method, which evaluates the nature of flood from the perspective of indicators such as frequency, duration, and magnitude, or indirect factors such as rainfall and soil loss, this paper conducts qualitative calculation of macro-scale indicators from the perspective of post-disaster losses in previous years. This study provides a new way of thinking and method for the classification of the flood disaster, which has certain practical application value under the condition of conforming to its own use.

Gray Related Analysis on Shaped-charge Rod Penetrator Shaped

The gray relation among the design parameters of the cumulative charge rod penetrator (CCRP) is analyzed adopting the gray systematic theory and method, and the gray related matrix among the parameters is obtained. The result parameters of CCRP and the main parameters of influencing the CCRP molding are obtained utilizing numerical simulation. This lays the foundation of CCRP design and provides a kind of effective research method.

Characterization and Pathogenicity of Pseudopestalotiopsis vietnamensis Causing Gray Blight of Wuyi Rock Tea(Camellia sinensis)in China and Specific Mechanisms of Disease Infection

Gray blight disease(GBD)causes significant losses in tea production in China.Although genes and biological processes involved in resistance to fungal disease in tea plants have been identified,specific mechanisms of the GBD infection process remain unknown.In this study,morphological and multi-gene(TEF-TUB-ITS)phylogenetic characteristics were used to identify isolate CLBB1 of Pseudopestalotiopsis vietnamensis.Pathogenicity tests confirmed that isolate CLBB1 from tea leaves caused GBD in the susceptible tea cultivar Wuyi Rock(Camellia sinensis var.sinensis cv.Shuixian).Spores began to germinate 24 h after infection(hai),and after 48 h,elongated fungal hyphae formed from a single conidium.Transcriptome analysis revealed that 482,517,and 369 genes were differentially expressed at 24,48,and 72 hai,respectively,in Wuyi Rock tea leaves.Isolate CLBB1 infection elicited phenotype-related responses and activated defense-related pathways,including plant–pathogen interaction,MAPK signaling,and plant hormone signal transduction,suggesting a possible mechanism underlying phenotype-based susceptibility to CLBB1.Thus,a new Ps.vietnamensis strain causing GBD in the tea cultivar‘Shuixian’was discovered in this study.Transcriptome analysis indicated that pathogen invasion activated chitin-related MAPK pathways and that tea plants required a hormone to restrict CLBB1.

Genetic Analysis of Resistance to Tomato Gray Mold( Botrytis cinerea)

The study used four tomato varieties,03786( susceptible),05237( susceptible),C2985( resistant) and Wva536( resistant) with different resistance,to formulate combinations according to Griffing( I) complete diallel cross method. And Botrytis cinerea was inoculated to investigate the incidence of gray mold. The results showed that:(1) there were significant differences in disease resistance between different varieties and different combinations.(2) There were significant differences in general combining ability and special combining ability between the tested varieties,and Wva536 and C2985 had a higher general combining ability effect,and were both relatively good parents when formulating resistant combinations. Combinations Wva536 × 03786 and Wva536 × 05237 had the highest special combining ability,and thus have the value of further research and utilization.(3) The additive effect in resistance inheritance was located at the primary position,and partial dominance also existed as well as cytoplasmic effect.(4) The broad-sense heritability and narrow-sense heritability were,respectively,89. 73% and82. 15%,which were higher,indicating that the parents had a greater effect on offsprings. The resistance genes can be expressed in offsprings through gene accumulation,and should be selected in the early generation.

Influencing Factors of Fabric-Skin Adhesion Based on Gray Correlation Analysis Method

Fabric-skin adhesion was objectively described by the indices of the maximum adhesion force F_(max) , the maximum separation distance L_(max) ,and adhesion work W as well as the adhesion force-separation distance curve. Firstly,gray correlation analysis method was adopted to investigate the correlation levels between adhesion indices,and secondly the relative importance of fabric structural parameters to fabric-skin adhesion,as well as the correlation levels between skin adhesion, water absorption, and wicking properties of the fabric. The results prove that W exhibits clear correlations with both F_(max) and L_(max) , yet the relevance between F_(max) and L_(max) is weak. Fabric adhesion indices are most associated with fabric mass and least with fabric thickness,whereas fabric wicking and water absorption present closest correlation with fabric thickness. Therefore, it is concluded that the relevance between fabric wicking, water absorption, and skin-adhesion properties are rather comprehensive than straight.

16S rRNA Gene Sequence Analysis of Snow Leopard, Gray Wolf, Horse and Bactrian Camel in Mongolia

In this study, mitochondrial 16S rRNA sequences of snow leopard, gray wolf, domestic horse and Bactrian camel inhabited or domesticated in Mongolian territory were obtained by using polymerase chain reaction （PCR） based on universal primers for 16S rRNA （F-5＇-AACGAGCCTGGTGATA-3＇ and R-5＇-CTCCGGTCTGAACTCAGATCACGTA-3＇）. The 16S rRNA sequence was 1,048 bp to 1,086 bp in length, and each sequence was compared to other related species （Felidae, Camelidae, Equidae and Canidae） by using NCBI Basic Local Alignment Search Tool （BLAST）. Results showed that sequences were highly similar to sequences in GenBank database （93%-99%）. Then phylogenetic analysis was performed based on about 1,100 bp sequence of 16S rRNA for Panthera uncia, Canis lupus, Equus caballus, Camelus bactrianus and other related species. The result revealed that P. uncia and P. leo were sister species, C. bactrianus and C. ferus were more closely related species, and wolf and dog were the almost similar species. This finding could be important for designing species specific primers for PCR based analysis of animal species identification and forensic veterinary medicine.

Partner Selection Analysis and System Development Based on Gray Relation Analysis for an Agile Virtual Enterprise

This paper analyzes the state of the art of partner selection and enumerates the advantage of partner selection based on gray relation analysis comparing to the other algorithms of the partner selection. Furthermore, partner selection system based on gray relation for an Agile Virtual Enterprise（AVE） is analyzed and designed based on the definition and characteristics of the AVE. According to J2EE mode, the architecture of the partner selection system is put forward and the system is developed t^ing JSP, EJB and SQL Server. The paper lays emphasis on a gray relational mathematic model, AVE evaluation infrastructure, a core algorithm of partner selection and a multi-layer gray relation selection process.

Identification of key genes and active anti-inflammatory ingredients in Panax medicinal plants by climate-regulated callus culture combined with gene-component-efficacy gray correlation analysis

Objective:We aimed to establish a novel strategy for identifying key genes and active anti-inflammatory ingredients in Panax medicinal plants.Methods:First,fresh roots of 2-year-old Panax plants,including P.ginseng C.A.Mey.,P.quinquefolium L.,P.notoginseng(Burk.)F.H.Chen,P.japonicus C.A.Mey.,P.japonicus Mey.var.major(Burk.)C.Y.Wu et K.M.Feng,were selected as explants,and callus formation was induced under three experimental temperatures(17,24,and 30℃).Second,high-performance liquid chromatography-mass spectrometry was used to analyze the saponin content of the callus.Nitric oxide reduction efficacy was used for“component-efficacy”gray correlation analysis to find the active anti-inflammatory ingredients.Quantitative reverse-transcription polymerase chain reaction(qRT-PCR)was used to determine the inflammatory factors and verify the active ingredients’anti-inflammatory effects.Finally,qRT-PCR was used to detect the expression of key genes in the callus,and“gene-component”gray correlation analysis was used to examine the relationships between the regulatory pathway of the genes and the components.Results:Among the three experimental temperatures(17,24,and 30℃),the lowest temperature(17℃)is the most suitable for generating Panax callus.Lower-latitude native Panax notoginseng is more adaptable under high culture temperatures(24℃and 30℃)than other Panax plants.The ginsenoside contents of the callus of P.notoginseng and P.japonicus were the highest under similar climate conditions(17℃).Major anti-inflammatory components were G-Rh1,G-Rb1,G-Rg3,and G-Rh6/FloralGKa.CYP76A47 contributed to the accumulation of anti-inflammatory components.Conclusions:This study provides a strategy for the gene-component-efficacy correlational study of multi-component,multi-functional,and multi-purpose plants of the same genus.

A Correlation Analysis of Tourism Based on Gray Theory——A case of Xingwen County

Tourism industry has already become an important part of national economy,which not only played a positive role in the development of the economy,but promoted the adjustment and optimization of industrial structure.The paper analyzes the correlation between the tourism industry and the other industry through changes of the Xingwen County tourism industrial output value in the past seven years.With the Gray Model,the correlation degree among the tourism industry and agriculture,industry,transport,wholesale and retail trade,postal and telecommunications industries is measured.The analysis result indicates that the order of the corresponding correlation degree:catering accommodation is 0.691> wholesale and retail is 0.617 > agriculture is 0.616 > Postal and telecommunications industry is 0.610> Transport is 0.602> Industry is 0.537.In accordance with the actual conditions of the industry in Xingwen,the industrial development policies and measures are put forward,which help the tourism industry Xingwen their rapid,coordinated and highly efficient operation.

Cooperative Angles-Only Relative Navigation Algorithm for Multi-Spacecraft Formation in Close-Range

As to solve the collaborative relative navigation problem for near-circular orbiting small satellites in close-range under GNSS denied environment,a novel consensus constrained relative navigation algorithm based on the lever arm effect of the sensor offset from the spacecraft center of mass is proposed.Firstly,the orbital propagation model for the relative motion of multi-spacecraft is established based on Hill-Clohessy-Wiltshire dynamics and the line-of-sight measurement under sensor offset condition is modeled in Local Vertical Local Horizontal frame.Secondly,the consensus constraint model for the relative orbit state is constructed by introducing the geometry constraint between the spacecraft,based on which the consensus unscented Kalman filter is designed.Thirdly,the observability analysis is done and the necessary conditions of the sensor offset to make the state observable are obtained.Lastly,digital simulations are conducted to verify the proposed algorithm,where the comparison to the unconstrained case is also done.The results show that the estimated error of the relative position converges very quickly,the location error is smaller than 10m under the condition of 10−3 rad level camera and 5m offset.

Correlation analysis of longitudinal cracks and vertical deformation within asphalt pavement of cold regions

The asphalt pavement longitudinal crack is a common distress in cold regions,resulting from uneven deformation of the subgrade.Analysis of the correlation law between uneven deformation and crack distress is of positive significance for understanding the mechanism of crack initiation,and putting forward treatment measures.In view of the complexity of longitudinal crack inducement and road surface deformation,the grey relational method was used to analyze this relationship.Through long-term monitoring of the vertical deformation data of typical road sections,the vertical deformation law of the pavement surface and its deformation characteristics under the action of temperature field are analyzed.Parameters such as vertical relative deformation,vertical relative deformation rate and vertical differential deformation VDSr were constructed to describe vertical deformation characteristics.Typical distribution characteristics of longitudinal fractures and their length and distribution characteristics are also described.The grey correlation analysis theory was utilized to analyze the relationship between deformation characteristics of sections,cross sections and monitoring points and longitudinal crack characteristics(length and location).The analysis reveals a linear positive correlation or a high correlation between several indicators.This study can provide a deeper understanding of the occurrence and development mechanism of longitudinal cracks in asphalt pavement of cold areas,and give references for the research of road engineering structure,materials and distress prevention.

Materials Selection of Thermoplastic Matrices of Natural Fibre Composites for Cyclist Helmet Using an Integration of DMAIC Approach in Six Sigma Method Together with Grey Relational Analysis Approach

Natural fibre reinforced polymer composite(NFRPC)materials are gaining popularity in the modern world due to their eco-friendliness,lightweight nature,life-cycle superiority,biodegradability,low cost,and noble mechanical properties.Due to the wide variety of materials available that have comparable attributes and satisfy the requirements of the product design specification,material selection has become a crucial component of design for engineers.This paper discusses the study’s findings in choosing the suitable thermoplastic matrices of Natural Fibre Composites for Cyclist Helmet utilising the DMAIC,and GRA approaches.The results are based on integrating two decision methods implemented utilising two distinct decision-making approaches:qualitative and quantitative.This study suggested thermoplastic polyethylene as a particularly ideal matrix in composite cyclist helmets during the selection process for the best thermoplastic matrices material using the 6σtechnique,with the decision based on the highest performance,the lightest weight,and the most environmentally friendly criteria.The DMAIC and GRA approach significantly influenced the material selection process by offering different tools for each phase.In the future study,selection technique may have been more exhaustive if more information from other factors had been added.