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Geochemical Modeling and Statistical Analysis for Groundwater Evolution Assessment in Wadi Qasab, Sohag, Eastern Desert, Egypt
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作者 Ehab Zaghlool 《Journal of Geoscience and Environment Protection》 2020年第9期33-61,共29页
Qasab basin is one of the most promising areas for the sustainable development in the Eastern Desert fringes of the Nile Valley, Egypt. The integration between statistical analysis, stable isotopes as well as geochemi... Qasab basin is one of the most promising areas for the sustainable development in the Eastern Desert fringes of the Nile Valley, Egypt. The integration between statistical analysis, stable isotopes as well as geochemical modeling tools delineated the geochemical possesses affecting groundwater quality and detected the main recharge source in Qasab basin. The most of groundwater samples are brackish (88%), while the minority (12%) of the samples are fresh. The electrical conductivity of groundwater ranged from 1135 to 10,030 μS/cm. The statistical analysis and hydrochemical diagrams suggest that the groundwater quality is mainly controlled by several intermixed processes (rock weathering and agricultural activities). The mineralization of the Pleistocene groundwater is regulated by the rock weathering source, evaporation processes and reverse cation exchange. The isotopic signatures (δ<sup>2</sup>H and δ<sup>18</sup>O) represent two groundwater groups. The first group, is enriched with the isotopic signature of δ<sup>18</sup>O, which ranges from 0.9‰ to 5.5‰. This group is mostly affected by the recent meteoric recharge from the surface water leakage. The second group, is relatively depleted with the isotopic signature of δ<sup>18</sup>O, reflecting a palaeo recharge source of colder climate. The δ<sup>18</sup>O‰ varies from <span style="color:#4F4F4F;font-family:"font-size:14px;white-space:normal;background-color:#FFFFFF;">&#45</span>10.1‰ to <span style="color:#4F4F4F;font-family:"font-size:14px;white-space:normal;background-color:#FFFFFF;">&#45</span>6.4‰, indicating upward leakage of the Nubian sandstone aquifer through deep seated faults. The inverse geochemical model reflects that the salinity source of the groundwater samples is due to the leaching and dissolution processes of carbonate, sulphate and chloride minerals from the aquifer matrix. This study can demonstrate the hydrochemistry assessment guide to support sustainable development in Qasab basin to ensure that adequate groundwater management can play to reduce poverty and support socioeconomic development. 展开更多
关键词 HYDROCHEMISTRY statistical analysis Stable Isotopes Inverse Geochemical modeling and Qasab Basin EGYPT
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Optimal Deep Learning Enabled Statistical Analysis Model for Traffic Prediction 被引量:1
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作者 Ashit Kumar Dutta S.Srinivasan +4 位作者 S.N.Kumar T.S.Balaji Won Il Lee Gyanendra Prasad Joshi Sung Won Kim 《Computers, Materials & Continua》 SCIE EI 2022年第9期5563-5576,共14页
Due to the advances of intelligent transportation system(ITSs),traffic forecasting has gained significant interest as robust traffic prediction acts as an important part in different ITSs namely traffic signal control... Due to the advances of intelligent transportation system(ITSs),traffic forecasting has gained significant interest as robust traffic prediction acts as an important part in different ITSs namely traffic signal control,navigation,route mapping,etc.The traffic prediction model aims to predict the traffic conditions based on the past traffic data.For more accurate traffic prediction,this study proposes an optimal deep learning-enabled statistical analysis model.This study offers the design of optimal convolutional neural network with attention long short term memory(OCNN-ALSTM)model for traffic prediction.The proposed OCNN-ALSTM technique primarily preprocesses the traffic data by the use of min-max normalization technique.Besides,OCNN-ALSTM technique was executed for classifying and predicting the traffic data in real time cases.For enhancing the predictive outcomes of the OCNN-ALSTM technique,the bird swarm algorithm(BSA)is employed to it and thereby overall efficacy of the network gets improved.The design of BSA for optimal hyperparameter tuning of the CNN-ALSTM model shows the novelty of the work.The experimental validation of the OCNNALSTM technique is performed using benchmark datasets and the results are examined under several aspects.The simulation results reported the enhanced outcomes of the OCNN-ALSTM model over the recent methods under several dimensions. 展开更多
关键词 statistical analysis predictive models deep learning traffic prediction bird swarm algorithm
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A tool model for predicting atmospheric chemical kinetics with sensitivity analysis
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作者 SHEN Ji (Research Center for Eco\|Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China.E\|mail:shenji@mail.rcees.ac.cn) 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2001年第1期79-86,共8页
A package(a tool model) for program of predicting atmospheric chemical kinetics with sensitivity analysis is presented. The new direct method of calculating the first order sensitivity coefficients using sparse matri... A package(a tool model) for program of predicting atmospheric chemical kinetics with sensitivity analysis is presented. The new direct method of calculating the first order sensitivity coefficients using sparse matrix technology to chemical kinetics is included in the tool model, it is only necessary to triangularize the matrix related to the Jacobian matrix of the model equation. The Gear type procedure is used to integrate a model equation and its coupled auxiliary sensitivity coefficient equations. The FORTRAN subroutines of the model equation, the sensitivity coefficient equations, and their Jacobian analytical expressions are generated automatically from a chemical mechanism. The kinetic representation for the model equation and its sensitivity coefficient equations, and their Jacobian matrix is presented. Various FORTRAN subroutines in packages, such as SLODE, modified MA28, Gear package, with which the program runs in conjunction are recommended. The photo\|oxidation of dimethyl disulfide is used for illustration. 展开更多
关键词 atmospheric chemical model chemical kinetics sensitivity analysis
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Constructing refined null models for statistical analysis of signed networks
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作者 李艾纹 肖婧 许小可 《Chinese Physics B》 SCIE EI CAS CSCD 2021年第3期571-577,共7页
The establishment of effective null models can provide reference networks to accurately describe statistical properties of real-life signed networks.At present,two classical null models of signed networks(i.e.,sign an... The establishment of effective null models can provide reference networks to accurately describe statistical properties of real-life signed networks.At present,two classical null models of signed networks(i.e.,sign and full-edge randomized models)shuffle both positive and negative topologies at the same time,so it is difficult to distinguish the effect on network topology of positive edges,negative edges,and the correlation between them.In this study,we construct three re-fined edge-randomized null models by only randomizing link relationships without changing positive and negative degree distributions.The results of nontrivial statistical indicators of signed networks,such as average degree connectivity and clustering coefficient,show that the position of positive edges has a stronger effect on positive-edge topology,while the signs of negative edges have a greater influence on negative-edge topology.For some specific statistics(e.g.,embeddedness),the results indicate that the proposed null models can more accurately describe real-life networks compared with the two existing ones,which can be selected to facilitate a better understanding of complex structures,functions,and dynamical behaviors on signed networks. 展开更多
关键词 signed networks null models statistical analysis average degree connectivity EMBEDDEDNESS
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A statistical analysis of geomechanical data and its effect on rock mass numerical modeling:a case study
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作者 Piotr Malkowski Zbigniew Niedbalski Tafida Balarabe 《International Journal of Coal Science & Technology》 EI CAS CSCD 2021年第2期312-323,共12页
Geomechanical data are never sufficient in quantity or adequately precise and accurate for design purposes in mining and civil engineering.The objective of this paper is to show the variability of rock properties at t... Geomechanical data are never sufficient in quantity or adequately precise and accurate for design purposes in mining and civil engineering.The objective of this paper is to show the variability of rock properties at the sampled point in the roadway's roof,and then,how the statistical processing of the available geomechanical data can affect the results of numerical modelling of the roadway's stability.Four cases were applied in the numerical analysis,using average values(the most common in geomechanical data analysis),average minus standard deviation,median,and average value minus statistical error.The study show that different approach to the same geomechanical data set can change the modelling results considerably.The case shows that average minus standard deviation is the most conservative and least risky.It gives the displacements and yielded elements zone in four times broader range comparing to the average values scenario,which is the least conservative option.The two other cases need to be studied further.The results obtained from them are placed between most favorable and most adverse values.Taking the average values corrected by statistical error for the numerical analysis seems to be the best solution.Moreover,the confidence level can be adjusted depending on the object importance and the assumed risk level. 展开更多
关键词 statistical analysis Geotechnical data Laboratory tests on rocks Numerical modelling
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A New Statistical Modeling Approach for Survival Analysis of Cancer Patients—Multiple Myeloma Cancer
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作者 Lohuwa Mamudu Chris P. Tsokos 《Open Journal of Applied Sciences》 2021年第4期365-378,共14页
<strong>Background:</strong> The Cox Proportional Hazard (Cox-PH) model has been a popularly used method for survival analysis of cancer data given the survival times as a function of covariates or risk fa... <strong>Background:</strong> The Cox Proportional Hazard (Cox-PH) model has been a popularly used method for survival analysis of cancer data given the survival times as a function of covariates or risk factors. However, it is very seldom to see the assumptions for the application of the Cox-PH model satisfied in most of the research studies, raising questions about the effectiveness, robustness, and accuracy of the model predicting the proportion of survival times. This is because the necessary assumptions in most cases are difficult to satisfy, as well as the assessment of interaction among covariates. <strong>Methods:</strong> To further improve the therapeutic/treatment strategy for cancer diseases, we proposed a new approach to survival analysis using multiple myeloma (MM) cancer data. We first developed a data-driven nonlinear statistical model that predicts the survival times with 93% accuracy. We then performed a parametric analysis on the predicted survival times to obtain the survival function which is used in estimating the proportion of survival times. <strong>Results:</strong> The new proposed approach for survival analysis has proved to be more robust and gives better estimates of the proportion of survival than the Cox-PH model. Also, satisfying the proposed model assumptions and finding interactions among risk factors is less difficult compared to the Cox-PH model. The proposed model can predict the real values of the survival times and the identified risk factors are ranked according to the percent of contribution to the survival time. <strong>Conclusion:</strong> The new proposed nonlinear statistical model approach for survival analysis of cancer diseases is very efficient and provides an improved and innovative strategy for cancer therapeutic/treatment. 展开更多
关键词 Health Science Multiple Myeloma Cancer Cancer Therapeutic Cox-PH model statistical model Survival analysis Probability Estimation
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Joint multivariate statistical model and its applications to synthetic earthquake predic-tion 被引量:14
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作者 韩天锡 蒋淳 +2 位作者 魏雪丽 韩梅 冯德益 《地震学报》 CSCD 北大核心 2004年第5期523-528,625,共6页
针对目前地震综合预报中的一些问题,利用近30年来迅速发展的多元统计分析中主成分分析、判别分析组成多元统计组合模型,在众多的地震预报指标(预报因子)中采用信息最大化方法,选择对中期预测信息累积贡献率大于90%地震预报指标,分... 针对目前地震综合预报中的一些问题,利用近30年来迅速发展的多元统计分析中主成分分析、判别分析组成多元统计组合模型,在众多的地震预报指标(预报因子)中采用信息最大化方法,选择对中期预测信息累积贡献率大于90%地震预报指标,分别进行相关分析、预测、检验,最终应用马氏距离判别作外推综合预报;并以华北地区(30°~42°N,108°125°E)为例进行模型的应用检验,初步研究已取得了较好的效果. 展开更多
关键词 多元统计组合模型 主成分分析 判别分析 地震综合预报
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Joint multivariate statistical model and its applications to the synthetic earthquake prediction
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作者 HAN Tian-xi(韩天锡) +7 位作者 JIANG Chun(蒋淳) WEI Xue-li(魏雪丽) HAN Me(韩梅) FENG De-yi(冯德益) 《Acta Seismologica Sinica(English Edition)》 CSCD 2004年第5期578-584,共8页
Considering the problems that should be solved in the synthetic earthquake prediction at present, a new model is proposed in the paper. It is called joint multivariate statistical model combined by principal component... Considering the problems that should be solved in the synthetic earthquake prediction at present, a new model is proposed in the paper. It is called joint multivariate statistical model combined by principal component analysis with discriminatory analysis. Principal component analysis and discriminatory analysis are very important theories in multivariate statistical analysis that has developed quickly in the late thirty years. By means of maximization information method, we choose several earthquake prediction factors whose cumulative proportions of total sam-ple variances are beyond 90% from numerous earthquake prediction factors. The paper applies regression analysis and Mahalanobis discrimination to extrapolating synthetic prediction. Furthermore, we use this model to charac-terize and predict earthquakes in North China (30~42N, 108~125E) and better prediction results are obtained. 展开更多
关键词 joint multivariate statistical model principal component analysis discriminatory analysis syn-thetic earthquake predication
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Statistical analysis for genome-wide association study
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作者 Ping Zeng Yang Zhao +6 位作者 Cheng Qian Liwei Zhang Ruyang Zhang Jianwei Gou Jin Liu Liya Liu Feng Chen 《The Journal of Biomedical Research》 CAS CSCD 2015年第4期285-297,共13页
In the past few years, genome-wide association study (GWAS) has made great successes in identifying genetic susceptibility loci underlying many complex diseases and traits. The findings provide important genetic ins... In the past few years, genome-wide association study (GWAS) has made great successes in identifying genetic susceptibility loci underlying many complex diseases and traits. The findings provide important genetic insights into understanding pathogenesis of diseases. In this paper, we present an overview of widely used approaches and strategies for analysis of GWAS, offered a general consideration to deal with GWAS data. The issues regarding data quality control, population structure, association analysis, multiple comparison and visual presentation of GWAS results are discussed; other advanced topics including the issue of missing heritability, meta-analysis, setbased association analysis, copy number variation analysis and GWAS cohort analysis are also briefly introduced. 展开更多
关键词 genome-wide association study quality control multiple comparison population structure genetic model statistical model missing heritability META-analysis copy number variation
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Ultrasonic backscatter characterization of cancellous bone using a general Nakagami statistical model 被引量:2
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作者 刘成成 东蕊 +4 位作者 李博艺 李颖 徐峰 他得安 王威琪 《Chinese Physics B》 SCIE EI CAS CSCD 2019年第2期313-320,共8页
The goal of this study is to analyze the statistics of the backscatter signal from bovine cancellous bone using a Nakagami model and to evaluate the feasibility of Nakagami-model parameters for cancellous bone charact... The goal of this study is to analyze the statistics of the backscatter signal from bovine cancellous bone using a Nakagami model and to evaluate the feasibility of Nakagami-model parameters for cancellous bone characterization. Ultrasonic backscatter measurements were performed on 24 bovine cancellous bone specimens in vitro and the backscatter signals were compensated for the frequency-dependent attenuation prior to the envelope detection. The statistics of the backscatter envelope were modeled using the Nakagami distribution. Our results reveal that the backscatter envelope mainly followed pre-Rayleigh distributions, and the deviations of the backscatter envelope from Rayleigh distribution decreased with increasing bone density. The Nakagami shape parameter(i.e., m) was significantly correlated with bone densities(R = 0.78–0.81, p < 0.001) and trabecular microstructures(|R| = 0.46–0.78, p < 0.05). The scale parameter(i.e.,?) and signal-to-noise ratio(SNR) also yielded significant correlations with bone density and structural features. Multiple linear regressions showed that bone volume fraction(BV/TV) was the main predictor of the Nakagami parameters,and microstructure produced significantly independent contribution to the prediction of Nakagami distribution parameters,explaining an additional 10.2% of the variance at most. The in vitro study showed that statistical parameters derived with Nakagami model might be useful for cancellous bone characterization, and statistical analysis has potential for ultrasonic backscatter bone evaluation. 展开更多
关键词 ULTRASONIC backscatter CANCELLOUS BONE statistical analysis NAKAGAMI model
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Modeling of Soot Formation in Gas Burner Using Reduced Chemical Kinetics Coupled with CFD Code 被引量:4
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作者 ZHANG Yindi ZHOU Huaichun XIE Mingliang FANG Qingyan WEI Yan 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2010年第6期967-978,共12页
A computational study of soot formation in ethylene/air coflow jet diffusion flame at atmospheric pres-sure was conducted using a reduced mechanism and soot formation model. A 20-step mechanism was derived from the fu... A computational study of soot formation in ethylene/air coflow jet diffusion flame at atmospheric pres-sure was conducted using a reduced mechanism and soot formation model. A 20-step mechanism was derived from the full mechanism using sensitivity analysis,reaction path analysis and quasi steady state(QSS) approximation. The model in premixed flame was validated and with computing savings in diffusion flame was applied by incor-porating into a CFD code. Simulations were performed to explore the effect of coflow air on flame structure and soot formation. Thermal radiation was calculated by a discrete-ordinates method,and soot formation was predicted by a simple two-equation soot model. Model results are in good agreement with those from experiment data and detailed mechanism at atmospheric conditions. The soot nucleation,growth,and oxidation by OH are all enhanced by decrease in coflow air velocity. The peak soot volume fraction region appears in the lower annular region be-tween the peak flame temperature and peak acetylene concentration locations,and the high soot oxidation rate due to the OH attack occurs in the middle annular region because of high temperature. 展开更多
关键词 化学反应动力学 CFD软件 气体燃烧器 烟尘 计算结果 耦合 建模 模型预测
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Template Matching using Statistical Model and Parametric Template for Multi-Template
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作者 Chin-Sheng Chen Jian-Jhe Huang Chien-Liang Huang 《Journal of Signal and Information Processing》 2013年第3期52-57,共6页
This paper represents a template matching using statistical model and parametric template for multi-template. This algorithm consists of two phases: training and matching phases. In the training phase, the statistical... This paper represents a template matching using statistical model and parametric template for multi-template. This algorithm consists of two phases: training and matching phases. In the training phase, the statistical model created by principal component analysis method (PCA) can be used to synthesize multi-template. The advantage of PCA is to reduce the variances of multi-template. In the matching phase, the normalized cross correlation (NCC) is employed to find the candidates in inspection images. The relationship between image block and multi-template is built to use parametric template method. Results show that the proposed method is more efficient than the conventional template matching and parametric template. Furthermore, the proposed method is more robust than conventional template method. 展开更多
关键词 MULTI-TEMPLATE TEMPLATE MATCHING PARAMETRIC TEMPLATE Normalized CROSS Correlation Principal Component analysis statistical model
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Log-cumulants of the finite mixture model and their application to statistical analysis of fully polarimetric UAVSAR data
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作者 Xinping Deng Jinsong Chen +2 位作者 Hongzhong Li Pengpeng Han Wen Yang 《Geo-Spatial Information Science》 SCIE CSCD 2018年第1期45-55,共11页
Since its first flight in 2007,the UAVSAR instrument of NASA has acquired a large number of fully Polarimetric SAR(PolSAR)data in very high spatial resolution.It is possible to observe small spatial features in this t... Since its first flight in 2007,the UAVSAR instrument of NASA has acquired a large number of fully Polarimetric SAR(PolSAR)data in very high spatial resolution.It is possible to observe small spatial features in this type of data,offering the opportunity to explore structures in the images.In general,the structured scenes would present multimodal or spiky histograms.The finite mixture model has great advantages in modeling data with irregular histograms.In this paper,a type of important statistics called log-cumulants,which could be used to design parameter estimator or goodness-of-fit tests,are derived for the finite mixture model.They are compared with logcumulants of the texture models.The results are adopted to UAVSAR data analysis to determine which model is better for different land types. 展开更多
关键词 Finite mixture model UAVSAR log-cumulant statistical analysis Polarimetric SAR(PolSAR)
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Correlation of ^1H NMR Chemical Shift for Aqueous Solutions by Statistical Associating Fluid Theory Association Model 被引量:2
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作者 许波 李浩然 +2 位作者 王从敏 许映杰 韩世钧 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2005年第2期280-284,共5页
^1H NMR chemical shifts of binary aqueous mixtures of acylamide, alcohol, dimethyl sulphoxide (DMSO), and acetone are correlated by statistical associating fluid theory (SAFT) association model. The comparison between... ^1H NMR chemical shifts of binary aqueous mixtures of acylamide, alcohol, dimethyl sulphoxide (DMSO), and acetone are correlated by statistical associating fluid theory (SAFT) association model. The comparison between SAFT association model and Wilson equation shows that the former is better for dealing with aqueous solutions. Finally, the specialties of both models are discussed. 展开更多
关键词 核磁共振技术 水溶液 氢键 敏感性 温度 热力学性质
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Factor analysis for the statistical modeling of earthquake-induced landslides
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作者 Jeng-Wen LIN Meng-Hsun HSIEH Yu-Jen LI 《Frontiers of Structural and Civil Engineering》 SCIE EI CSCD 2020年第1期123-126,共4页
Earthquake-induced landslides are difficult to assess and predict owing to the inherent unpredictability of earthquakes.In most existing studies,the landslide potential is statistically assessed by collecting and anal... Earthquake-induced landslides are difficult to assess and predict owing to the inherent unpredictability of earthquakes.In most existing studies,the landslide potential is statistically assessed by collecting and analyzing the data of historical landslide events and earthquake observation records.Unlike rainfall-induced landslides,earthquake-induced landslides cannot be predicted in advance using real-time monitoring systems,and the development of the models for these landslides should instead depend on early earthquake warnings and estimations.Hence,in this study,factor analysis was performed and the frequency distribution method was employed to investigate the potential risk of the landslides caused by earthquakes.Factors such as the slope gradient,lithology(geology),aspect,and elevation were selected and classified as influential factors to facilitate the construction of a landslide database for the area of study. 展开更多
关键词 EARTHQUAKE FACTOR analysis SLOPE LANDSLIDES statistical modeling
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The Statistical Experimental Design for Chemical Reactors Modeling
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作者 Graciela Prieto Oscar Prieto +3 位作者 Teresa Unzaga Carlos Gay Kazunori Takashima Akira Mizuno 《Applied Mathematics》 2016年第14期1534-1546,共13页
The Statistical Experimental Design techniques are the most powerful tools for the chemical reactors experimental modeling. Empirical models can be formulated for representing the chemical behavior of reactors with th... The Statistical Experimental Design techniques are the most powerful tools for the chemical reactors experimental modeling. Empirical models can be formulated for representing the chemical behavior of reactors with the minimal effort in the necessary number of experimental runs, hence, minimizing the consumption of chemicals and the consumption of time due to the reduction in the number of experimental runs and increasing the certainty of the results. Four types of nonthermal plasma reactors were assayed seeking for the highest efficiency in obtaining hydrogen and ethylene. Three different geometries for AC high voltage driven reactors, and only a single geometry for a DC high voltage pulse driven reactor were studied. According to the fundamental principles of chemical kinetics and considering an analogy among the reaction rate and the applied power to the plasma reactor, the four reactors are modeled following the classical chemical reactors design to understand if the behavior of the nonthermal plasma reactors can be regarded as the chemical reactors following the flow patterns of PFR (Plug Flow Reactor) or CSTR (Continuous Stirred Tank Reactor). Dehydrogenation is a common elimination reaction that takes place in nonthermal plasmas. Owing to this characteristic, a paraffinic heavy oil with an average molecular weight corresponding to C15 was used to study the production of light olefins and hydrogen. 展开更多
关键词 chemical Reactors modeling statistical Experimental Designs Nonthermal Plasma chemical Reactors
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Estimating inter-regional trade flows in China: A sector-specific statistical model 被引量:5
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作者 LIU Weidong LlXin +2 位作者 LIU Hongguang TANG Zhipeng GUAN Dabo 《Journal of Geographical Sciences》 SCIE CSCD 2015年第10期1247-1263,共17页
China has huge differences among its regions in terms of socio-economic development, industrial structure, natural resource endowments, and technological advancement. These differences have created complicated linkage... China has huge differences among its regions in terms of socio-economic development, industrial structure, natural resource endowments, and technological advancement. These differences have created complicated linkages between regions in China. In this study, building upon gravity model and location quotient techniques, we develop a sector-specific model to estimate inter-provincial trade flows, which is the base for making a multi-regional input-output table. In the model, we distinguish sectors with less intra-sector input from those with larger intra-sector input, and assume that the former sectors tend to compete among regions while the latter tend to cooperate among regions. Then we apply this new method of inter-regional trade estimation to three sectors: food and tobacco, metal smelting and proc- essing, and electrical equipment. The results show that selection of bandwidth has a significant impact on the assessment of inter-regional trade. Trade flows are more scattered with the increase of bandwidths. As a result, bandwidth reflects the spatial concentration of geo- graphical activities, which should be distinguishable for different industries. We conclude that the sector-specific spatial model can increase the credibility of estimates of inter-regional trade flows. 展开更多
关键词 multi-regional input-output analysis trade flows sector-specific statistical model China
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Evaluation of hydro-chemistry in a phreatic aquifer in the Vindhyan Region, India, using entropy weighted approach and geochemical modelling
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作者 Ashutosh Mishra Aman Rai +1 位作者 Prabuddh Kumar Mishra Suresh Chand Rai 《Acta Geochimica》 EI CAS CSCD 2023年第4期648-672,共25页
Groundwater quality monitoring and geochemical characterization in the phreatic aquifer are critical for ensuring universal and equitable access to clean,reliable,and inexpensive drinking water for all.This research w... Groundwater quality monitoring and geochemical characterization in the phreatic aquifer are critical for ensuring universal and equitable access to clean,reliable,and inexpensive drinking water for all.This research was intended to investigate the hydrogeochemical attributes and mechanisms regulating the chemistry of groundwater as well as to assess spatial variation in groundwater quality in Satna district,India.To accomplish this,the groundwater data comprising 13 physio-chemical parameters from thirty-eight phreatic aquifer locations were analysed for May 2020 by combining entropy-weighted water quality index(EWQI),multivariate statistics,geochemical modelling,and geographical information system.The findings revealed that the groundwater is fresh and slightly alkaline.Hardness was a significant concern as 57.89% of samples were beyond the permissible limit of the World Health Organisation.The dominance of ions were in the order of Ca^(2+)> Na^(+)> Mg^(2+)> K^(+) and HCO_(3)^(-)> SO_(4)^(2-)> Cl^-> NO_(3)^(-)> F^(-).Higher concentration of these ions is mainly concentrated in the northeast and eastern regions.Pearson correlation analysis and principal component analysis(PCA) demonstrated that both natural and human factors regulate groundwater chemistry in the region.The analysis of Q-mode agglomerative hierarchical clustering highlighted three significant water clusters.Ca-HCO_3 was the most prevalent hydro-chemical facies in all three clusters.Geochemical modelling through various conventional plots indicated that groundwater chemistry in the research region is influenced by the dissolution of calcite/dolomite,reverse ion exchange,and by silicate and halite weathering.EWQI data of the study area disclosed that 73.69% of the samples were appropriate for drinking.Due to high salinity,Magnesium(Mg^(2+)),Nitrate(NO_(3)^(-)),and Bicarbonate(HCO_(3)^(-)) concentrations,the north-central and north-eastern regions are particularly susceptible.The findings of the study may be accomplished by policymakers and groundwater managers to achieve sustainable groundwater development at the regional scale. 展开更多
关键词 Groundwater quality assessment EWQI Multivariate statistical analysis Geochemical modelling Hydrogeochemical processes Saturation index
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Symbolic Macromodeling for Statistical Simulation of Operational Amplifiers
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作者 Lan-Lan Dong Guo-Yong Shi Jian-Dong Cheng 《Journal of Electronic Science and Technology》 CAS 2013年第3期272-276,共5页
Symbolic circuit simulator is traditionally applied to the small-signal analysis of analog circuits. This paper establishes a symbolic behavioral macromodeling method applicable to both small-signal and large-signal a... Symbolic circuit simulator is traditionally applied to the small-signal analysis of analog circuits. This paper establishes a symbolic behavioral macromodeling method applicable to both small-signal and large-signal analysis of general two-stage operational amplifiers (op-amps). The proposed method creates a two-pole parametric macromodel whose parameters are analytical functions of the circuit element parameters generated by a symbolic circuit simulator. A moment matching technique is used in deriving the analytical model parameter. The created parametric behavioral model can be used for op-amps performance simulation in both frequency and time domains. In particular, the parametric models are highly suited for fast statistical simulation of op-amps in the time-domain. Experiment results show that the statistical distributions of the op-amp slew and settling time characterized by the proposed model agree well with the transistor-level results in addition to achieving significant speedup. 展开更多
关键词 Index Terms---Analog behavioral model large-signalanalysis moment matching operational amplifiers process variation statistical analysis symbolic analysis.
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Multivariate Statistical Process Monitoring and Control: Recent Developments and Applications to Chemical Industry 被引量:39
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作者 梁军 钱积新 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2003年第2期191-203,共13页
Multivariate statistical process monitoring and control (MSPM& C) methods for chemical process monitoring with statistical projection techniques such as principal component analysis (PCA) and partial least squares... Multivariate statistical process monitoring and control (MSPM& C) methods for chemical process monitoring with statistical projection techniques such as principal component analysis (PCA) and partial least squares (PLS) are surveyed in this paper,The four-step procedure of performing MSPM &C for chemical process ,modeling of processes ,detecting abnormal events or faults,identifying the variable(s) responible for the faults and diagnosing the source cause for the abnormal behavior,is analyzed,Several main research directions of MSPM&C reported in the literature are discussed,such as multi-way principal component analysis (MPCA) for batch process ,statistical monitoring and control for nonlinear process,dynamic PCA and dynamic PLS,and on -line quality control by infer-ential models,Industrial applications of MSPM&C to several typical chemical processes ,such as chemical reactor,distillation column,polymeriztion process ,petroleum refinery units,are summarized,Finally,some concluding remarks and future considerations are made. 展开更多
关键词 多变量统计过程监控 化学工业 应用 研究进展
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