期刊文献+
共找到995,327篇文章
< 1 2 250 >
每页显示 20 50 100
Country-based modelling of COVID-19 case fatality rate:A multiple regression analysis
1
作者 Soodeh Sagheb Ali Gholamrezanezhad +2 位作者 Elizabeth Pavlovic Mohsen Karami Mina Fakhrzadegan 《World Journal of Virology》 2024年第1期84-94,共11页
BACKGROUND The spread of the severe acute respiratory syndrome coronavirus 2 outbreak worldwide has caused concern regarding the mortality rate caused by the infection.The determinants of mortality on a global scale c... BACKGROUND The spread of the severe acute respiratory syndrome coronavirus 2 outbreak worldwide has caused concern regarding the mortality rate caused by the infection.The determinants of mortality on a global scale cannot be fully understood due to lack of information.AIM To identify key factors that may explain the variability in case lethality across countries.METHODS We identified 21 Potential risk factors for coronavirus disease 2019(COVID-19)case fatality rate for all the countries with available data.We examined univariate relationships of each variable with case fatality rate(CFR),and all independent variables to identify candidate variables for our final multiple model.Multiple regression analysis technique was used to assess the strength of relationship.RESULTS The mean of COVID-19 mortality was 1.52±1.72%.There was a statistically significant inverse correlation between health expenditure,and number of computed tomography scanners per 1 million with CFR,and significant direct correlation was found between literacy,and air pollution with CFR.This final model can predict approximately 97%of the changes in CFR.CONCLUSION The current study recommends some new predictors explaining affect mortality rate.Thus,it could help decision-makers develop health policies to fight COVID-19. 展开更多
关键词 COVID-19 SARS-CoV-2 Case fatality rate Predictive model Multiple regression
下载PDF
Multiple regression analysis of risk factors related to radiation pneumonitis
2
作者 Ling-Ling Shi Jiang-Hua Yang Hong-Fa Yao 《World Journal of Clinical Cases》 SCIE 2023年第5期1040-1048,共9页
BACKGROUND Radiation pneumonitis(RP)is a severe complication of thoracic radiotherapy that may lead to dyspnea and lung fibrosis,and negatively affects patients’quality of life.AIM To carry out multiple regression an... BACKGROUND Radiation pneumonitis(RP)is a severe complication of thoracic radiotherapy that may lead to dyspnea and lung fibrosis,and negatively affects patients’quality of life.AIM To carry out multiple regression analysis on the influencing factors of radiation pneumonitis.METHODS Records of 234 patients receiving chest radiotherapy in Huzhou Central Hospital(Huzhou,Zhejiang Province,China)from January 2018 to February 2021,and the patients were divided into either a study group or a control group based on the presence of radiation pneumonitis or not.Among them,93 patients with radiation pneumonitis were included in the study group and 141 without radiation pneumonitis were included in the control group.General characteristics,and radiation and imaging examination data of the two groups were collected and compared.Due to the statistical significance observed,multiple regression analysis was performed on age,tumor type,chemotherapy history,forced vital capacity(FVC),forced expiratory volume in the first second(FEV1),carbon monoxide diffusion volume(DLCO),FEV1/FVC ratio,planned target area(PTV),mean lung dose(MLD),total number of radiation fields,percentage of lung tissue in total lung volume(vdose),probability of normal tissue complications(NTCP),and other factors.RESULTS The proportions of patients aged≥60 years and those with the diagnosis of lung cancer and a history of chemotherapy in the study group were higher than those in the control group(P<0.05);FEV1,DLCO,and FEV1/FVC ratio in the study group were lower than those in the control group(P<0.05),while PTV,MLD,total field number,vdose,and NTCP were higher than in the control group(P<0.05).Logistic regression analysis showed that age,lung cancer diagnosis,chemotherapy history,FEV1,FEV1/FVC ratio,PTV,MLD,total number of radiation fields,vdose,and NTCP were risk factors for radiation pneumonitis.CONCLUSION We have identified patient age,type of lung cancer,history of chemotherapy,lung function,and radiotherapy parameters as risk factors for radiation pneumonitis.Comprehensive evaluation and examination should be carried out before radiotherapy to effectively prevent radiation pneumonitis. 展开更多
关键词 Radiation pneumonitis Influencing factors RADIOTHERAPY Multiple regression analysis
下载PDF
Probability Based Regression Analysis for the Prediction of Cardiovascular Diseases
3
作者 Wasif Akbar Adbul Mannan +3 位作者 Qaisar Shaheen Mohammad Hijji Muhammad Anwar Muhammad Ayaz 《Computers, Materials & Continua》 SCIE EI 2023年第6期6269-6286,共18页
Machine Learning(ML)has changed clinical diagnostic procedures drastically.Especially in Cardiovascular Diseases(CVD),the use of ML is indispensable to reducing human errors.Enormous studies focused on disease predict... Machine Learning(ML)has changed clinical diagnostic procedures drastically.Especially in Cardiovascular Diseases(CVD),the use of ML is indispensable to reducing human errors.Enormous studies focused on disease prediction but depending on multiple parameters,further investigations are required to upgrade the clinical procedures.Multi-layered implementation of ML also called Deep Learning(DL)has unfolded new horizons in the field of clinical diagnostics.DL formulates reliable accuracy with big datasets but the reverse is the case with small datasets.This paper proposed a novel method that deals with the issue of less data dimensionality.Inspired by the regression analysis,the proposed method classifies the data by going through three different stages.In the first stage,feature representation is converted into probabilities using multiple regression techniques,the second stage grasps the probability conclusions from the previous stage and the third stage fabricates the final classifications.Extensive experiments were carried out on the Cleveland heart disease dataset.The results show significant improvement in classification accuracy.It is evident from the comparative results of the paper that the prevailing statistical ML methods are no more stagnant disease prediction techniques in demand in the future. 展开更多
关键词 Machine learning heart disease cardiac disease deep regression regression learning
下载PDF
Logistic Regression Trust–A Trust Model for Internet-of-Things Using Regression Analysis
4
作者 Feslin Anish Mon Solomon Godfrey Winster Sathianesan R.Ramesh 《Computer Systems Science & Engineering》 SCIE EI 2023年第2期1125-1142,共18页
Internet of Things(IoT)is a popular social network in which devices are virtually connected for communicating and sharing information.This is applied greatly in business enterprises and government sectors for deliveri... Internet of Things(IoT)is a popular social network in which devices are virtually connected for communicating and sharing information.This is applied greatly in business enterprises and government sectors for delivering the services to their customers,clients and citizens.But,the interaction is success-ful only based on the trust that each device has on another.Thus trust is very much essential for a social network.As Internet of Things have access over sen-sitive information,it urges to many threats that lead data management to risk.This issue is addressed by trust management that help to take decision about trust-worthiness of requestor and provider before communication and sharing.Several trust-based systems are existing for different domain using Dynamic weight meth-od,Fuzzy classification,Bayes inference and very few Regression analysis for IoT.The proposed algorithm is based on Logistic Regression,which provide strong statistical background to trust prediction.To make our stand strong on regression support to trust,we have compared the performance with equivalent sound Bayes analysis using Beta distribution.The performance is studied in simu-lated IoT setup with Quality of Service(QoS)and Social parameters for the nodes.The proposed model performs better in terms of various metrics.An IoT connects heterogeneous devices such as tags and sensor devices for sharing of information and avail different application services.The most salient features of IoT system is to design it with scalability,extendibility,compatibility and resiliency against attack.The existing worksfinds a way to integrate direct and indirect trust to con-verge quickly and estimate the bias due to attacks in addition to the above features. 展开更多
关键词 LRTrust logistic regression trust management internet of things
下载PDF
COVID-19 mortality trends before and after the national vaccination program in Iran: A joinpoint regression analysis
5
作者 Mojtaba Sepandi Yousef Alimohamadi Kolsoom Alimohamadi 《Journal of Acute Disease》 2023年第6期215-218,共4页
Objective:To investigate the trend of mortality by COVID-19 before and after the national vaccination program using joinpoint regression analysis from 19 February 2020 to 5 September 2022.Methods:In the present study,... Objective:To investigate the trend of mortality by COVID-19 before and after the national vaccination program using joinpoint regression analysis from 19 February 2020 to 5 September 2022.Methods:In the present study,a joinpoint regression analysis of monthly collected data on confirmed deaths of COVID-19 in Iran from February 19,2020 to September 5,2022 was performed.Results:After national vaccination in Iran,the trend of new monthly deaths due to COVID-19 was decreasing.The percentage of monthly changes from the beginning of the pandemic to the 19th month was 6.62%(95%CI:1.1,12.4),which had an increasing trend.From the 19th month to the end of the 31st month,the mortality trend was decreasing,and the percentage of monthly changes was-20.05%(95%CI:-8.3,-30.3)(P=0.002).The average percentage of monthly changes was-5%with a 95%CI of(-10.5,0.9).Conclusions:Along with other health measures,such as quarantine,wearing a mask,hand washing,social distancing,etc.,national vaccination significantly reduces the mortality rate of COVID-19. 展开更多
关键词 COVID-19 Iran Joinpoint regression MORTALITY TREND VACCINATION
下载PDF
Efficacy and prognosis of adjuvant treatment of endometrial cancer with medroxyprogesterone acetate COX regression analysis
6
作者 Ding-Ran Wang 《World Journal of Clinical Cases》 SCIE 2023年第23期5447-5454,共8页
BACKGROUND Endometrial cancer is one of the most commonly diagnosed gynecological cancers worldwide,and early-stage high-risk endometrial cancer has a poor prognosis.Adjuvant treatments after surgery,such as chemother... BACKGROUND Endometrial cancer is one of the most commonly diagnosed gynecological cancers worldwide,and early-stage high-risk endometrial cancer has a poor prognosis.Adjuvant treatments after surgery,such as chemotherapy and radiotherapy,have been widely used in clinical practice to improve patient survival.Medroxyprogesterone acetate is a synthetic progestogen that has been reported to have potential anticancer effects in endometrial cancer.However,its efficacy,safety,and longterm prognostic benefits as an adjuvant treatment for endometrial cancer remain controversial.Therefore,this study aimed to observe the efficacy and prognostic impact of adjuvant medroxyprogesterone acetate treatment in patients with earlystage high-risk endometrial cancer and evaluate its safety.AIM To observe the efficacy and prognosis of adjuvant treatment of endometrial cancer with medroxyprogesterone acetate and to evaluate its safety.METHODS We collected the clinical data of 200 patients with early-stage high-risk endometrial cancer who were admitted to the Department of Obstetrics and Gynecology of our hospital from January 2018 to December 2022.The control group(100 patients)underwent conventional surgical treatment,and the study group(100 patients)was administered adjuvant medroxyprogesterone acetate tablets on top of the control group.The Kaplan-Meier curve analysis and log-rank test were performed to determine the possible factors influencing the 5-year cumulative survival rate in the patients.The Cox regression analysis was performed to identify the factors influencing the survival prognosis of endometrial cancer.RESULTS According to the Cox regression analysis,age[hazard ratio(HR)=4.636,95%confidence interval(95%CI):1.411-15.237],pathological type(HR=6.943,95%CI:2.299-20.977),molecular typing(HR=5.789,95%CI:3.305-10.141),and myometrial infiltration(HR=5.768,95%CI:1.898-17.520)were factors influencing the prognosis of patients with early-stage high-risk endometrial cancer.CONCLUSION Age,pathological type,molecular typing,and myometrial infiltration were all relevant factors affecting the prognosis of early-stage high-risk endometrial cancer.The potential long-term prognostic benefit of adjuvant postoperative radiotherapy in patients with early-stage high-risk endometrial cancer is worthy of clinical consideration. 展开更多
关键词 Endometrial cancer Independent risk factors Postoperative adjuvant therapy Clinical analysis Prognostic analysis
下载PDF
A New Extended BIC and Sequential Lasso Regression Analysis and Their Application in Classification
7
作者 Jie Chen Wanzhou Ye 《Advances in Pure Mathematics》 2023年第5期284-302,共19页
In this paper, firstly, we propose a new method for choosing regularization parameter λ for lasso regression, which differs from traditional method such as multifold cross-validation, our new method gives the maximum... In this paper, firstly, we propose a new method for choosing regularization parameter λ for lasso regression, which differs from traditional method such as multifold cross-validation, our new method gives the maximum value of parameter λ directly. Secondly, by considering another prior form over model space in the Bayes approach, we propose a new extended Bayes information criterion family, and under some mild condition, our new EBIC (NEBIC) is shown to be consistent. Then we apply our new method to choose parameter for sequential lasso regression which selects features by sequentially solving partially penalized least squares problems where the features selected in earlier steps are not penalized in the subsequent steps. Then sequential lasso uses NEBIC as the stopping rule. Finally, we apply our algorithm to identify the nonzero entries of precision matrix for high-dimensional linear discrimination analysis. Simulation results demonstrate that our algorithm has a lower misclassification rate and less computation time than its competing methods under considerations. 展开更多
关键词 Regularization Parameter Sequential Procedure BIC Linear Discrimination analysis Feature Selection
下载PDF
Logistics Regression Analysis between TCM Constitution Types of Patients with Hypertension,Insomnia and ABPM,PSQI 被引量:2
8
作者 Xiaogang YU Qingsheng WANG +2 位作者 Erdan XIN Yujun LU Yingdong LI 《Medicinal Plant》 CAS 2022年第2期44-49,54,共7页
[Objectives]The research aimed to explore the distribution characteristics of TCM constitution types of patients with hypertension and insomnia,and study the clinical characteristics of patients with different constit... [Objectives]The research aimed to explore the distribution characteristics of TCM constitution types of patients with hypertension and insomnia,and study the clinical characteristics of patients with different constitutions,in order to provide new ideas for the treatment of patients with hypertension and insomnia.[Methods]Cross sectional observation method was used,and 420 patients with hypertension and insomnia were selected.Required information was collected,and the constitution type of traditional Chinese medicine was determined,and relevant data were recorded.SPSS and Logistic regression analysis method were used to explore the correlation between the distribution of TCM constitution types and gender,age,24 h-SBP,24 h-DBP,24 h-BPV,PSQI score,etc.[Results]Among 420 patients,the proportion of gentleness constitution was the most,and others in turn were Qi deficiency constitution>Yang deficiency constitution>phlegm dampness constitution>Qi stagnation constitution>Yin deficiency constitution>blood stasis constitution>damp heat constitution>special constitution.Among male patients,the proportion of gentleness constitution was the most.Among female patients,the proportion of Qi deficiency constitution was the most.In each constitution,the proportion of men and women was different,and the difference in gentleness constitution,Qi deficiency constitution and Yin deficiency constitution had statistical significance(P<0.05).The proportion of gentleness constitution for young and middle-aged patients was the most,while elderly patients with Qi deficiency constitution was the most.There was difference in the distribution of TCM constitution in different age groups,and the difference had statistical significance(P<0.05).Compared with the patients with gentleness constitution,the patients with Qi deficiency constitution,Yang deficiency constitution,Yin deficiency constitution,damp heat constitution,blood stasis constitution and Qi stagnation constitution had different differences in terms of age,24 h-SBP,24 h-DBP,24 h-BPV and PSQI score,and there was statistical significance(P<0.05).Except damp heat constitution,blood stasis constitution and special constitution,other constitutions had certain correlation with age,24 h-SBP,24 h-DBP,24 h-BPV and PSQI score.[Conclusions]TCM constitution types of patients with hypertension and insomnia were dominant by gentleness constitution,Qi deficiency constitution and Yang deficiency constitution.The distribution of TCM constitution in different gender and age groups was different,and different TCM constitution was related to ABPM and PSQI. 展开更多
关键词 Hypertension with insomnia Constitution of traditional Chinese medicine ABPM PSQI Logistics regression analysis
下载PDF
Research on the Effect of Artificial Intelligence Real Estate Forecasting Using Multiple Regression Analysis and Artificial Neural Network: A Case Study of Ghana 被引量:1
9
作者 Madami Michael Ishaku Hill Isaac Lewu 《Journal of Computer and Communications》 2021年第10期1-14,共14页
To transition from conventional to intelligent real estate, the real estate industry must enhance its embrace of disruptive technology. Even though the real estate auction market has grown in importance in the financi... To transition from conventional to intelligent real estate, the real estate industry must enhance its embrace of disruptive technology. Even though the real estate auction market has grown in importance in the financial, economic, and investment sectors, few artificial intelligence-based research has tried to predict the auction values of real estate in the past. According to the objectives of this research, artificial intelligence and statistical methods will be used to create forecasting models for real estate auction prices. A multiple regression model and an artificial neural network are used in conjunction with one another to build the forecasting models. For the empirical study, the study utilizes data from Ghana apartment auctions from 2016 to 2020 to anticipate auction prices and evaluate the forecasting accuracy of the various models available at the time. Compared to the conventional Multiple Regression Analysis, using artificial intelligence systems for real estate appraisal is becoming a more viable option (MRA). The Artificial Neural network model exhibits the most outstanding performance, and efficient zonal segmentation based on the auction evaluation price enhances the model’s prediction accuracy even more. There is a statistically significant difference between the two models when it comes to forecasting the values of real estate auctions. 展开更多
关键词 Real Estate Forecasting Artificial Intelligence Artificial Neural Networks Multiple regression analysis
下载PDF
Factor Decomposition and Regression Analysis of the Energy Related Carbon Emissions in Shandong, China: A Perspective of Industrial Structure
10
作者 Weifeng Gong Baoqing Zhu +3 位作者 Chuanhui Wang Zhenyue Fan Mengzhen Zhao Liang Chen 《Energy Engineering》 EI 2021年第4期981-994,共14页
An in-depth study of the energy related carbon emissions has important practical significance for carbon emissions reduction and structural adjustment in Shandong Province and throughout China.Based on the perspective... An in-depth study of the energy related carbon emissions has important practical significance for carbon emissions reduction and structural adjustment in Shandong Province and throughout China.Based on the perspective of industrial structure,the expanded KAYA equation to measure the energy related carbon emissions of the primary industries(Resources and Agriculture)and secondary industries(Manufacturing and Construction)and tertiary industries(Retail and Service)was utilized in Shandong Province from 2011 to 2017.The carbon emissions among industries in Shandong Province were empirically analyzed using the Logarithmic Mean Divisia Index decomposition approach.The results were follows:(1)Under the three industrial dimensions,the energy structure effect and the energy intensity effect have a restraining influence on the carbon emissions of the three industries.(2)The development level effect and the employment scale effect play a pulling role in carbon emissions.(3)From the perspective of the employment structure effect of the primary industry,there is a restraining effect on carbon emissions,while the employment structure effects of the secondary and tertiary industries play a pulling role in carbon emissions,and the employment structure effect of the tertiary industry has a greater pulling effect on carbon emissions than the secondary industry. 展开更多
关键词 Carbon emissions industrial structure expanded KAYA equation LMDI decomposition regression analysis
下载PDF
Multiple Regression Analysis of Influencing Factors on Yield of New Sugarcane Variety Yuetang 03-373
11
作者 Fangyin PAN Fuye LIU +1 位作者 Mingfu WEN Qingwen LUO 《Asian Agricultural Research》 2020年第5期47-49,共3页
[Objectives]The purpose of this study was to provide reference for cultivation and promotion of a new sugarcane variety Yuetang 03-373,on the basis of analyzing and summarizing the characters of the variety.[Methods]C... [Objectives]The purpose of this study was to provide reference for cultivation and promotion of a new sugarcane variety Yuetang 03-373,on the basis of analyzing and summarizing the characters of the variety.[Methods]Correlation,multiple regression and path analyses were performed for the yield and yield components of Yuetang 03-373.[Results]Correlation analysis shows that cane yield was significantly correlated with millable stalk number,stalk length and stalk diameter,and among them,the correlation with millable stalk number was the strongest.Multiple regression and path analyses show that millable stalk number contributed the most to cane yield,followed by stalk length,and stalk diameter contributed the least.The regression equation of cane yield against the three yield components was y=-2.8713+1.5497x1+5.8990x2-395.4294x3(R=0.9672**).[Conclusions]Millable stalk number and stalk length were the important and major factors for high yield of Yuetang 03-373,indicating that Yuetang 03-373 is a sugarcane variety of millable stalk type.In cultivation,full play should be given to the advantage of Yuetang 03-373 in millable stalk number,as well as stalk length(plant height),in order to achieve the purpose of increasing yield. 展开更多
关键词 Yuetang 03-373 Yield traits Correlation analysis Multiple regression analysis
下载PDF
Using Linear Regression Analysis and Defense in Depth to Protect Networks during the Global Corona Pandemic
12
作者 Rodney Alexander 《Journal of Information Security》 2020年第4期261-291,共31页
The purpose of this research was to determine whether the Linear Regression Analysis can be effectively applied to the prioritization of defense-in-depth security tools and procedures to reduce cyber threats during th... The purpose of this research was to determine whether the Linear Regression Analysis can be effectively applied to the prioritization of defense-in-depth security tools and procedures to reduce cyber threats during the Global Corona Virus Pandemic. The way this was determined or methods used in this study consisted of scanning 20 peer reviewed Cybersecurity Articles from prominent Cybersecurity Journals for a list of defense in depth measures (tools and procedures) and the threats that those measures were designed to reduce. The methods further involved using the Likert Scale Model to create an ordinal ranking of the measures and threats. The defense in depth tools and procedures were then compared to see whether the Likert scale and Linear Regression Analysis could be effectively applied to prioritize and combine the measures to reduce pandemic related cyber threats. The results of this research reject the H0 null hypothesis that Linear Regression Analysis does not affect the relationship between the prioritization and combining of defense in depth tools and procedures (independent variables) and pandemic related cyber threats (dependent variables). 展开更多
关键词 Information Assurance Defense in Depth Information Technology Network Security CYBERSECURITY Linear regression analysis PANDEMIC
下载PDF
Logistic Regression Analysis of Influencing Factors on Serum ALT and HCV RNA Changes in Patients with Chronic Hepatitis C
13
作者 Cheng-bao Wang Jian-jie Chen +3 位作者 Hong-ming Nie Feng Gao Hua Lv Hong-ding Li 《国际感染病学(电子版)》 CAS 2012年第2期80-83,共4页
Objective This study was undertaken to investigate the influencing factors on serum ALT level and hepatitis C virus(HCV)RNA titer in chronic hepatitis C(CHC)patients.Methods All patients enrolled into this study were ... Objective This study was undertaken to investigate the influencing factors on serum ALT level and hepatitis C virus(HCV)RNA titer in chronic hepatitis C(CHC)patients.Methods All patients enrolled into this study were anti-HCV positive.Retrospective tracing method was applied to detect serum ALT level and HCV RNA titer and to collect general information of the patients such as genders,age groups,interferon medication history,infection pathways,height and weight.Then the multi-factor analysis was adopted with the application of binominal logistic regression mode.Results The abnormal rate of ALT level was positively correlated to HCV RNA and gender while negatively correlated to interferon medication history and age group,with Wald value of the 4 factors as 39.604,11.823,18.991 and 7.389,respectively.The positive rate of HCV RNA was negatively correlated to interferon medication history and gender while positively correlated to ALT level,with corresponding Wald value of the 3 factors as81.394,7.618 and 27.562,respectively.Conclusions The normal ALT level in HCV infected patients was associated with viral load,age,gender and interferon medication history,while the normal rate of HCV RNA titer was closely associated with gender,interferon medication history and ALT level. 展开更多
关键词 Multi-factor logistic regression analysis Hepatitis C virus Chronic Hepatitis C Serum ALT level HCV RNA
下载PDF
Modified scaled distance regression analysis approach for prediction of blast-induced ground vibration in multi-hole blasting 被引量:9
14
作者 Hemant Agrawal A.K.Mishra 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2019年第1期202-207,共6页
The blast-induced ground vibration prediction using scaled distance regression analysis is one of the most popular methods employed by engineers for many decades. It uses the maximum charge per delay and distance of m... The blast-induced ground vibration prediction using scaled distance regression analysis is one of the most popular methods employed by engineers for many decades. It uses the maximum charge per delay and distance of monitoring as the major factors for predicting the peak particle velocity(PPV). It is established that the PPV is caused by the maximum charge per delay which varies with the distance of monitoring and site geology. While conducting a production blasting, the waves induced by blasting of different holes interfere destructively with each other, which may result in higher PPV than the predicted value with scaled distance regression analysis. This phenomenon of interference/superimposition of waves is not considered while using scaled distance regression analysis. In this paper, an attempt has been made to compare the predicted values of blast-induced ground vibration using multi-hole trial blasting with single-hole blasting in an opencast coal mine under the same geological condition. Further,the modified prediction equation for the multi-hole trial blasting was obtained using single-hole regression analysis. The error between predicted and actual values of multi-hole blast-induced ground vibration was found to be reduced by 8.5%. 展开更多
关键词 Peak particle velocity(PPV) Blast-induced ground vibration Scaled distance regression analysis Wave SUPERIMPOSITION SINGLE-HOLE BLASTING
下载PDF
Isolated Area Load Forecasting using Linear Regression Analysis: Practical Approach 被引量:16
15
作者 M. A. Mahmud 《Energy and Power Engineering》 2011年第4期547-550,共4页
This paper presents an analysis to forecast the loads of an isolated area where the history of load is not available or the history may not represent the realistic demand of electricity. The analysis is done through l... This paper presents an analysis to forecast the loads of an isolated area where the history of load is not available or the history may not represent the realistic demand of electricity. The analysis is done through linear regression and based on the identification of factors on which electrical load growth depends. To determine the identification factors, areas are selected whose histories of load growth rate known and the load growth deciding factors are similar to those of the isolated area. The proposed analysis is applied to an isolated area of Bangladesh, called Swandip where a past history of electrical load demand is not available and also there is no possibility of connecting the area with the main land grid system. 展开更多
关键词 ISOLATED Area LOAD Forecasting LINEAR regression analysis (LRA).
下载PDF
Design of crown pillar thickness using finite element method and multivariate regression analysis 被引量:3
16
作者 Kumar Hemant Deb Debasis Chakravarty D. 《International Journal of Mining Science and Technology》 SCIE EI CSCD 2017年第6期955-964,共10页
Minerals are now being extracted from deep mines due to drying up of resource in shallow ground. The need for suitable supports and ground control mechanisms for safe mining necessitates proper pillar design with fill... Minerals are now being extracted from deep mines due to drying up of resource in shallow ground. The need for suitable supports and ground control mechanisms for safe mining necessitates proper pillar design with filling technology. In addition, high horizontal stress may cause collapse of hanging wall and footwall rocks, hence designing of suitable crown pillars is absolutely necessary for imposing overall safety of the stopes. This paper provides a methodology for the evaluation of the required thickness of crown pillars for safe operation at depth ranging from 600 m to 1000 m. Analyses are conducted with the results of 108 non-linear numerical models considering Drucker-Prager material model in plane strain condition. Material properties of ore body rock and thickness of crown pillars are varied and safety factors of pillars estimated. Then, a generalized statistical relationship between the safety factors of crown pillars with the various input parameters is developed. The developed multivariate regression model is utilized for generating design/stability charts of pillars for different geo-mining conditions.These design charts can be used for the design of crown pillar thickness with the depth of the working,taking into account the changes of the rock mass conditions in underground metal mine. 展开更多
关键词 CUT and FILL mining CROWN PILLAR FEM regression model DESIGN CHART
下载PDF
Comparison of School Building Construction Costs Estimation Methods Using Regression Analysis, Neural Network, and Support Vector Machine 被引量:2
17
作者 Gwang-Hee Kim Jae-Min Shin +1 位作者 Sangyong Kim Yoonseok Shin 《Journal of Building Construction and Planning Research》 2013年第1期1-7,共7页
Accurate cost estimation at the early stage of a construction project is key factor in a project’s success. But it is difficult to quickly and accurately estimate construction costs at the planning stage, when drawin... Accurate cost estimation at the early stage of a construction project is key factor in a project’s success. But it is difficult to quickly and accurately estimate construction costs at the planning stage, when drawings, documentation and the like are still incomplete. As such, various techniques have been applied to accurately estimate construction costs at an early stage, when project information is limited. While the various techniques have their pros and cons, there has been little effort made to determine the best technique in terms of cost estimating performance. The objective of this research is to compare the accuracy of three estimating techniques (regression analysis (RA), neural network (NN), and support vector machine techniques (SVM)) by performing estimations of construction costs. By comparing the accuracy of these techniques using historical cost data, it was found that NN model showed more accurate estimation results than the RA and SVM models. Consequently, it is determined that NN model is most suitable for estimating the cost of school building projects. 展开更多
关键词 ESTIMATING Construction COSTS regression analysis NEURAL Network Support VECTOR MACHINE
下载PDF
Variance Inflation Factor: As a Condition for the Inclusion of Suppressor Variable(s) in Regression Analysis 被引量:6
18
作者 Michael Olusegun Akinwande Hussaini Garba Dikko Agboola Samson 《Open Journal of Statistics》 2015年第7期754-767,共14页
Suppression effect in multiple regression analysis may be more common in research than what is currently recognized. We have reviewed several literatures of interest which treats the concept and types of suppressor va... Suppression effect in multiple regression analysis may be more common in research than what is currently recognized. We have reviewed several literatures of interest which treats the concept and types of suppressor variables. Also, we have highlighted systematic ways to identify suppression effect in multiple regressions using statistics such as: R2, sum of squares, regression weight and comparing zero-order correlations with Variance Inflation Factor (VIF) respectively. We also establish that suppression effect is a function of multicollinearity;however, a suppressor variable should only be allowed in a regression analysis if its VIF is less than five (5). 展开更多
关键词 Suppression Effect MULTICOLLINEARITY Variance INFLATION Factor (VIF) regression and Correlation STEPWISE Selection
下载PDF
Leakage Rate Model of Urban Water Supply Networks Using Principal Component Regression Analysis 被引量:1
19
作者 Zhiguang Niu Chong Wang +2 位作者 Ying Zhang Xiaoting Wei Xili Gao 《Transactions of Tianjin University》 EI CAS 2018年第2期172-181,共10页
To analyze the factors affecting the leakage rate of water distribution system, we built a macroscopic "leakage rate–leakage factors"(LRLF) model. In this model, we consider the pipe attributes(quality, dia... To analyze the factors affecting the leakage rate of water distribution system, we built a macroscopic "leakage rate–leakage factors"(LRLF) model. In this model, we consider the pipe attributes(quality, diameter,age), maintenance cost, valve replacement cost, and annual average pressure. Based on variable selection and principal component analysis results, we extracted three main principle components—the pipe attribute principal component(PAPC), operation management principal component, and water pressure principal component. Of these, we found PAPC to have the most influence. Using principal component regression, we established an LRLF model with no detectable serial correlations. The adjusted R2 and RMSE values of the model were 0.717 and 2.067, respectively.This model represents a potentially useful tool for controlling leakage rate from the macroscopic viewpoint. 展开更多
关键词 Water DISTRIBUTION system LEAKAGE RATE LEAKAGE influencing FACTOR QUANTITATIVE model Principal COMPONENT regression
下载PDF
Stability of mine ventilation system based on multiple regression analysis 被引量:12
20
作者 JIA Ting-gui LIU Jian 《Mining Science and Technology》 EI CAS 2009年第4期463-466,共4页
In order to overcome the disadvantages of diagonal connection structures that are complex and for which it is difficult to derive the discriminant of the airflow directions of airways,we have applied a multiple regres... In order to overcome the disadvantages of diagonal connection structures that are complex and for which it is difficult to derive the discriminant of the airflow directions of airways,we have applied a multiple regression method to analyze the effect,of changing the rules of mine airflows,on the stability of a mine ventilation system.The amount of air(Q j) is determined for the major airway and an optimum regression equation was derived for Qj as a function of the independent variable(Ri),i.e.,the ventilation resistance between different airways.Therefore,corresponding countermeasures are proposed according to the changes in airflows.The calculated results agree very well with our practical situation,indicating that multiple regression analysis is simple,quick and practical and is therefore an effective method to analyze the stability of mine ventilation systems. 展开更多
关键词 多元回归分析方法 矿井通风系统 稳定性 连接结构 方向判别 独立变量 回归方程 计算结果
下载PDF
上一页 1 2 250 下一页 到第
使用帮助 返回顶部