In this paper, a Gauss-Newton-based Broyden’s class method for parameters of regression problems is presented. The global convergence of this given method will be established under suitable conditions. Numerical resu...In this paper, a Gauss-Newton-based Broyden’s class method for parameters of regression problems is presented. The global convergence of this given method will be established under suitable conditions. Numerical results show that the proposed method is interesting.展开更多
The shortest width confidence interval (CI) for odds ratio (OR) in logistic regression is developed based on a theorem proved by Dahiya and Guttman (1982). When the variance of the logistic regression coefficient esti...The shortest width confidence interval (CI) for odds ratio (OR) in logistic regression is developed based on a theorem proved by Dahiya and Guttman (1982). When the variance of the logistic regression coefficient estimate is small, the shortest width CI is close to the regular Wald CI obtained by exponentiating the CI for the regression coefficient estimate. However, when the variance increases, the optimal CI may be up to 25% narrower. It is demonstrated that the shortest width CI is favorable because it has a smaller probability of covering the wrong OR value compared with the standard CI. The closed-form iterations based on the Newton's algorithm are provided, and the R function is supplied. A simulation study confirms the superior properties of the new CI for OR in small sample. Our method is illustrated with eight studies on parity as a preventive factor against bladder cancer in women.展开更多
In this paper, an overview of an important feature in statistics field has shown: the stepwise multiple linear regression. Likewise, a link between stepwise multiple linear regression and earthquakes localization has...In this paper, an overview of an important feature in statistics field has shown: the stepwise multiple linear regression. Likewise, a link between stepwise multiple linear regression and earthquakes localization has been descripted. Precisely, the aim of this research is showing how stepwise multiple linear regression contributes to solution of earthquakes localization, describing its conditions of use in HYPO71PC, a software devoted to computation of seismic sources’ collocation. This aim is reached treating a concrete case, that is computation of earthquakes localization happening on Mount Vesuvius, Italy.展开更多
Bangladesh is a subtropical monsoon climate characterized by wide seasonal variations in rainfall, moderately warm temperatures, and high humidity. Rainfall is the main source of irrigation water everywhere in the Ban...Bangladesh is a subtropical monsoon climate characterized by wide seasonal variations in rainfall, moderately warm temperatures, and high humidity. Rainfall is the main source of irrigation water everywhere in the Bangladesh where the inhabitants derive their income primarily from farming. Stochastic rainfall models were concerned with the occurrence of wet day and depth of rainfall for different regions to model the daily occurrence of rainfall and achieved satisfactory results around the world. In connection to the Markov chain of different order, logistic regression is conducted to visualize the dependence of current rainfall upon the rainfall of previous two-time period. It had been shown that wet day of the previous two time period compared to the dry day of previous two time period influences positively the wet day of current time period, that is the dependency of dry-wet spell for the occurrence of rain in the rainy season from April to September in the study area. Daily data are collected from meteorological department of about 26 years on rainfall of Dhaka station during the period January 1985-August 2011 to conduct the study. The test result shows that the occurrence of rainfall follows a second order Markov chain and logistic regression also tells that dry followed by dry and wet followed by wet is more likely for the rainfall of Dhaka station and also the model could perform adequately for many applications of rainfall data satisfactorily.展开更多
To stay competitive, the mobile telecommunication companies spend millions of Ghana cedi each year on building long-term relationships with their customers. Marketing managers are constantly challenged with the proble...To stay competitive, the mobile telecommunication companies spend millions of Ghana cedi each year on building long-term relationships with their customers. Marketing managers are constantly challenged with the problem of where to channel the limited resources in order to retain existing customers. This study approaches the customer retention problem in the mobile phone sector from a behavioural perspective, applying the Behavioural Perspective Model as the main analytical framework and further exploits some other factors that influence customer retention. The model includes a set of pre-behaviour and post-behaviour factors to study consumer choice, and explains its relevant drivers in a viable and comprehensive way, grounded in radical behaviourism. Data for the analysis were collected from tertiary students from Accra and Takoradi. Data collected were analysed using the multinomial regression technique. Analysis of the data revealed that the Behaviour setting factor is the only significant element in Behaviour Perspective Model. Further exploitation of behaviour situation revealed that the number of networks a customer uses, previous experience of a customer and customer’s intention are significant factors in determining customer retention in Ghana’s mobile telecommunication industry.展开更多
Objective: To evaluate the response to clinical and surgical treatment of Walter Cantidio University Hospital patients who were diagnosed with Barrett's esophagus between 2012 and 2016. Methodology: From the databa...Objective: To evaluate the response to clinical and surgical treatment of Walter Cantidio University Hospital patients who were diagnosed with Barrett's esophagus between 2012 and 2016. Methodology: From the database analysis of Walter Cantidio University Hospital's pathology service, we identified all patients with a diagnosis of Barrett's esophagus between 2012 and 2016. We analyzed the patients' medical records and collected epidemiological and clinical data. Results: 22 patients were included in the study, 13 of whom were surgically treated and 9 were clinically treated. The regression was 33.3% in the clinical group and 30.7% in the surgical group, with no statistical difference between these two groups. Conclusions: The results show synchrony with data from the medical literature regarding the response of Barrett's esophagus to clinical and surgical treatment.展开更多
It is meaningful to study trends in food and education expenditure as proportions of total household expenditure.In this study,based on year 2006 to 2017 data from Heilongjiang province in China and Ontario province i...It is meaningful to study trends in food and education expenditure as proportions of total household expenditure.In this study,based on year 2006 to 2017 data from Heilongjiang province in China and Ontario province in Canada,a linear regression model is used to forecast the Engel’s coefficients(proportion spent on food)and the education proportion from year 2018 to 2027 for those two regions.The results suggest that in both regions the Engel’s coefficients show a decreasing trend,while the education expenditure proportions show an increasing trend.The ratios of education expenditure to food expenditure in both places show an increasing trend.展开更多
Background: The Poisson and the Negative Binomial distributions are commonly used to model count data. The Poisson is characterized by the equality of mean and variance whereas the Negative Binomial has a variance lar...Background: The Poisson and the Negative Binomial distributions are commonly used to model count data. The Poisson is characterized by the equality of mean and variance whereas the Negative Binomial has a variance larger than the mean and therefore both models are appropriate to model over-dispersed count data. Objectives: A new two-parameter probability distribution called the Quasi-Negative Binomial Distribution (QNBD) is being studied in this paper, generalizing the well-known negative binomial distribution. This model turns out to be quite flexible for analyzing count data. Our main objectives are to estimate the parameters of the proposed distribution and to discuss its applicability to genetics data. As an application, we demonstrate that the QNBD regression representation is utilized to model genomics data sets. Results: The new distribution is shown to provide a good fit with respect to the “Akaike Information Criterion”, AIC, considered a measure of model goodness of fit. The proposed distribution may serve as a viable alternative to other distributions available in the literature for modeling count data exhibiting overdispersion, arising in various fields of scientific investigation such as genomics and biomedicine.展开更多
App store provides rich information for software vendors and customers to understand the market of mobile applications. However, app store analysis don’t consider some vital factors such as version number, app descri...App store provides rich information for software vendors and customers to understand the market of mobile applications. However, app store analysis don’t consider some vital factors such as version number, app description and app name currently. In this paper we propose an approach that App Store Analysis can be used to predict app downloads. We use data mining to extract app name and description and app rank information etc. from the Wandoujia App Store and AppCha App Store. We use questionnaire and sentimentanalysis to quantify some app nonnumeric information. We revealed strong correlations app name score, app rank, app rating with app downloads by Spearman’s rank correlation analysis respectively. Finally, we establish a multiple nonlinear regression model which app downloads defined as dependent variable and three relevant attributes defined as independent variable. On average, 59.28 % of apps in Wandoujia App Store and 66.68 % of apps in AppCha App Store can be predicted accurately within threshold which error rate is 25 %. One can observe the more detailed classification of app store, the more accurate for regression modeling to predict app downloads. Our approach can help app developers to notice and optimize the vital factors which influence app downloads.展开更多
目的应用Logistic回归模型评价常规超声特征及实时剪切波弹性成像技术对甲状腺良恶性结节鉴别诊断的价值。方法对80例甲状腺结节患者(108个结节)行常规超声及实时剪切波弹性成像检查,测得结节的杨氏模量值,以病理结果为金标准,应用ROC...目的应用Logistic回归模型评价常规超声特征及实时剪切波弹性成像技术对甲状腺良恶性结节鉴别诊断的价值。方法对80例甲状腺结节患者(108个结节)行常规超声及实时剪切波弹性成像检查,测得结节的杨氏模量值,以病理结果为金标准,应用ROC曲线得出良恶性结节的诊断临界值。总结结节术前二维灰阶、彩色多普勒及剪切波弹性成像的声像图特征,筛选出对甲状腺结节良恶性鉴别诊断最有价值的指标,并建立二分类Logistic回归模型。结果病理诊断108个甲状腺结节,良性组36个,恶性组72个。甲状腺良、恶性结节的最大杨氏模量值分别为(46.43±20.84)k Pa和(81.79±32.06)k Pa;平均杨氏模量值分别为(36.59±19.29)k Pa和(62.96±29.13)k Pa。良、恶性结节杨氏模量最大值和平均值差异均有统计学意义(P<0.05)。最大值与平均值ROC曲线下面积分别为0.828和0.783,分别以最大值52.00 k Pa和平均值37.35 k Pa作为诊断截点值,其诊断敏感度、特异度为91.7%、61.1%和86.1%、55.6%。Logistic回归分析显示进入回归方程的3个特征变量为纵横比、钙化及杨氏模量值,该Logistic回归模型对甲状腺结节良恶性预报的正确率为89.7%(35/39),ROC曲线下面积为0.949。结论实时剪切波弹性成像技术有助于鉴别甲状腺结节的良恶性,二分类Logistic回归模型筛选出对甲状腺结节良恶性鉴别诊断有意义的诊断指标,具有较高的临床应用价值。展开更多
地震P波、S波初至时间的拾取是地震波分析的一项基础性工作.本文提出了一种新的地震波初至时间自动拾取的方法:首先,把地震波的三分量时程曲线变换为一组空间向的能量变化率时程曲线;然后对能量变化率时程曲线进行STA/LTA(Short Time Av...地震P波、S波初至时间的拾取是地震波分析的一项基础性工作.本文提出了一种新的地震波初至时间自动拾取的方法:首先,把地震波的三分量时程曲线变换为一组空间向的能量变化率时程曲线;然后对能量变化率时程曲线进行STA/LTA(Short Time Average/Long Time Average,短时间的均值/长时间的均值)处理,拾取地震P波和S波的大致初至时间;最后提出采用一种二次方自回归模型对初至附近的能量变化率曲线进行二次方自回归处理,精确拾取出P波和S波的初至时间.本文采用了10组芦山地震的记录数据和150组汶川地震的记录数据对此方法的可靠性进行了检验.以人工拾取结果为参考,此方法具有很高的准确率和稳定性,同时,相比于常用的STA/LTA方法和AIC(Akaike Information Criterion,Akaike信息准则)方法,此方法在计算时间效率方面稍微逊色,但是对S波初至时间的拾取精度和可靠性更高.此方法丰富了地震P波、S波初至时间的自动拾取方法.展开更多
文摘In this paper, a Gauss-Newton-based Broyden’s class method for parameters of regression problems is presented. The global convergence of this given method will be established under suitable conditions. Numerical results show that the proposed method is interesting.
文摘The shortest width confidence interval (CI) for odds ratio (OR) in logistic regression is developed based on a theorem proved by Dahiya and Guttman (1982). When the variance of the logistic regression coefficient estimate is small, the shortest width CI is close to the regular Wald CI obtained by exponentiating the CI for the regression coefficient estimate. However, when the variance increases, the optimal CI may be up to 25% narrower. It is demonstrated that the shortest width CI is favorable because it has a smaller probability of covering the wrong OR value compared with the standard CI. The closed-form iterations based on the Newton's algorithm are provided, and the R function is supplied. A simulation study confirms the superior properties of the new CI for OR in small sample. Our method is illustrated with eight studies on parity as a preventive factor against bladder cancer in women.
文摘In this paper, an overview of an important feature in statistics field has shown: the stepwise multiple linear regression. Likewise, a link between stepwise multiple linear regression and earthquakes localization has been descripted. Precisely, the aim of this research is showing how stepwise multiple linear regression contributes to solution of earthquakes localization, describing its conditions of use in HYPO71PC, a software devoted to computation of seismic sources’ collocation. This aim is reached treating a concrete case, that is computation of earthquakes localization happening on Mount Vesuvius, Italy.
文摘Bangladesh is a subtropical monsoon climate characterized by wide seasonal variations in rainfall, moderately warm temperatures, and high humidity. Rainfall is the main source of irrigation water everywhere in the Bangladesh where the inhabitants derive their income primarily from farming. Stochastic rainfall models were concerned with the occurrence of wet day and depth of rainfall for different regions to model the daily occurrence of rainfall and achieved satisfactory results around the world. In connection to the Markov chain of different order, logistic regression is conducted to visualize the dependence of current rainfall upon the rainfall of previous two-time period. It had been shown that wet day of the previous two time period compared to the dry day of previous two time period influences positively the wet day of current time period, that is the dependency of dry-wet spell for the occurrence of rain in the rainy season from April to September in the study area. Daily data are collected from meteorological department of about 26 years on rainfall of Dhaka station during the period January 1985-August 2011 to conduct the study. The test result shows that the occurrence of rainfall follows a second order Markov chain and logistic regression also tells that dry followed by dry and wet followed by wet is more likely for the rainfall of Dhaka station and also the model could perform adequately for many applications of rainfall data satisfactorily.
文摘To stay competitive, the mobile telecommunication companies spend millions of Ghana cedi each year on building long-term relationships with their customers. Marketing managers are constantly challenged with the problem of where to channel the limited resources in order to retain existing customers. This study approaches the customer retention problem in the mobile phone sector from a behavioural perspective, applying the Behavioural Perspective Model as the main analytical framework and further exploits some other factors that influence customer retention. The model includes a set of pre-behaviour and post-behaviour factors to study consumer choice, and explains its relevant drivers in a viable and comprehensive way, grounded in radical behaviourism. Data for the analysis were collected from tertiary students from Accra and Takoradi. Data collected were analysed using the multinomial regression technique. Analysis of the data revealed that the Behaviour setting factor is the only significant element in Behaviour Perspective Model. Further exploitation of behaviour situation revealed that the number of networks a customer uses, previous experience of a customer and customer’s intention are significant factors in determining customer retention in Ghana’s mobile telecommunication industry.
文摘Objective: To evaluate the response to clinical and surgical treatment of Walter Cantidio University Hospital patients who were diagnosed with Barrett's esophagus between 2012 and 2016. Methodology: From the database analysis of Walter Cantidio University Hospital's pathology service, we identified all patients with a diagnosis of Barrett's esophagus between 2012 and 2016. We analyzed the patients' medical records and collected epidemiological and clinical data. Results: 22 patients were included in the study, 13 of whom were surgically treated and 9 were clinically treated. The regression was 33.3% in the clinical group and 30.7% in the surgical group, with no statistical difference between these two groups. Conclusions: The results show synchrony with data from the medical literature regarding the response of Barrett's esophagus to clinical and surgical treatment.
文摘It is meaningful to study trends in food and education expenditure as proportions of total household expenditure.In this study,based on year 2006 to 2017 data from Heilongjiang province in China and Ontario province in Canada,a linear regression model is used to forecast the Engel’s coefficients(proportion spent on food)and the education proportion from year 2018 to 2027 for those two regions.The results suggest that in both regions the Engel’s coefficients show a decreasing trend,while the education expenditure proportions show an increasing trend.The ratios of education expenditure to food expenditure in both places show an increasing trend.
文摘Background: The Poisson and the Negative Binomial distributions are commonly used to model count data. The Poisson is characterized by the equality of mean and variance whereas the Negative Binomial has a variance larger than the mean and therefore both models are appropriate to model over-dispersed count data. Objectives: A new two-parameter probability distribution called the Quasi-Negative Binomial Distribution (QNBD) is being studied in this paper, generalizing the well-known negative binomial distribution. This model turns out to be quite flexible for analyzing count data. Our main objectives are to estimate the parameters of the proposed distribution and to discuss its applicability to genetics data. As an application, we demonstrate that the QNBD regression representation is utilized to model genomics data sets. Results: The new distribution is shown to provide a good fit with respect to the “Akaike Information Criterion”, AIC, considered a measure of model goodness of fit. The proposed distribution may serve as a viable alternative to other distributions available in the literature for modeling count data exhibiting overdispersion, arising in various fields of scientific investigation such as genomics and biomedicine.
文摘App store provides rich information for software vendors and customers to understand the market of mobile applications. However, app store analysis don’t consider some vital factors such as version number, app description and app name currently. In this paper we propose an approach that App Store Analysis can be used to predict app downloads. We use data mining to extract app name and description and app rank information etc. from the Wandoujia App Store and AppCha App Store. We use questionnaire and sentimentanalysis to quantify some app nonnumeric information. We revealed strong correlations app name score, app rank, app rating with app downloads by Spearman’s rank correlation analysis respectively. Finally, we establish a multiple nonlinear regression model which app downloads defined as dependent variable and three relevant attributes defined as independent variable. On average, 59.28 % of apps in Wandoujia App Store and 66.68 % of apps in AppCha App Store can be predicted accurately within threshold which error rate is 25 %. One can observe the more detailed classification of app store, the more accurate for regression modeling to predict app downloads. Our approach can help app developers to notice and optimize the vital factors which influence app downloads.
文摘目的应用Logistic回归模型评价常规超声特征及实时剪切波弹性成像技术对甲状腺良恶性结节鉴别诊断的价值。方法对80例甲状腺结节患者(108个结节)行常规超声及实时剪切波弹性成像检查,测得结节的杨氏模量值,以病理结果为金标准,应用ROC曲线得出良恶性结节的诊断临界值。总结结节术前二维灰阶、彩色多普勒及剪切波弹性成像的声像图特征,筛选出对甲状腺结节良恶性鉴别诊断最有价值的指标,并建立二分类Logistic回归模型。结果病理诊断108个甲状腺结节,良性组36个,恶性组72个。甲状腺良、恶性结节的最大杨氏模量值分别为(46.43±20.84)k Pa和(81.79±32.06)k Pa;平均杨氏模量值分别为(36.59±19.29)k Pa和(62.96±29.13)k Pa。良、恶性结节杨氏模量最大值和平均值差异均有统计学意义(P<0.05)。最大值与平均值ROC曲线下面积分别为0.828和0.783,分别以最大值52.00 k Pa和平均值37.35 k Pa作为诊断截点值,其诊断敏感度、特异度为91.7%、61.1%和86.1%、55.6%。Logistic回归分析显示进入回归方程的3个特征变量为纵横比、钙化及杨氏模量值,该Logistic回归模型对甲状腺结节良恶性预报的正确率为89.7%(35/39),ROC曲线下面积为0.949。结论实时剪切波弹性成像技术有助于鉴别甲状腺结节的良恶性,二分类Logistic回归模型筛选出对甲状腺结节良恶性鉴别诊断有意义的诊断指标,具有较高的临床应用价值。
文摘地震P波、S波初至时间的拾取是地震波分析的一项基础性工作.本文提出了一种新的地震波初至时间自动拾取的方法:首先,把地震波的三分量时程曲线变换为一组空间向的能量变化率时程曲线;然后对能量变化率时程曲线进行STA/LTA(Short Time Average/Long Time Average,短时间的均值/长时间的均值)处理,拾取地震P波和S波的大致初至时间;最后提出采用一种二次方自回归模型对初至附近的能量变化率曲线进行二次方自回归处理,精确拾取出P波和S波的初至时间.本文采用了10组芦山地震的记录数据和150组汶川地震的记录数据对此方法的可靠性进行了检验.以人工拾取结果为参考,此方法具有很高的准确率和稳定性,同时,相比于常用的STA/LTA方法和AIC(Akaike Information Criterion,Akaike信息准则)方法,此方法在计算时间效率方面稍微逊色,但是对S波初至时间的拾取精度和可靠性更高.此方法丰富了地震P波、S波初至时间的自动拾取方法.