Pub Date : 2021-06-25DOI: 10.1285/I20705948V14N1P78
Xuemao Zhang
How reliable are the weather forecasts? Based on data collected from onehundred and thirteen cities in the United States over 38 months on threevariables, maximum temperature, minimum temperature and precipitation,accuracy of the weather forecasts was examined. The same day forecast hasbeen extremely accurate, especially for the maximum temperature, whilethe forecast errors and variability increase as forecasts go further out indays. Some cities have larger or smaller forecast errors than the others.For long-term weather forecasts, the maximum and minimum temperatureforecast errors has decreasing correlations overtime, respectively; However,the correlation between maximum and minimum temperature forecast errorsis positive and increasing overtime. The 7-days forecast errors of precipitationare pretty accurate.
{"title":"Exploratory Data Analysis of Accuracy of US Weather Forecastes","authors":"Xuemao Zhang","doi":"10.1285/I20705948V14N1P78","DOIUrl":"https://doi.org/10.1285/I20705948V14N1P78","url":null,"abstract":"How reliable are the weather forecasts? Based on data collected from onehundred and thirteen cities in the United States over 38 months on threevariables, maximum temperature, minimum temperature and precipitation,accuracy of the weather forecasts was examined. The same day forecast hasbeen extremely accurate, especially for the maximum temperature, whilethe forecast errors and variability increase as forecasts go further out indays. Some cities have larger or smaller forecast errors than the others.For long-term weather forecasts, the maximum and minimum temperatureforecast errors has decreasing correlations overtime, respectively; However,the correlation between maximum and minimum temperature forecast errorsis positive and increasing overtime. The 7-days forecast errors of precipitationare pretty accurate.","PeriodicalId":44770,"journal":{"name":"Electronic Journal of Applied Statistical Analysis","volume":"14 1","pages":"78-89"},"PeriodicalIF":0.7,"publicationDate":"2021-06-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49452571","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-05-20DOI: 10.1285/I20705948V14N1P13
Saima Afzal, M. Iqbal, Ayesha Afzal
Independent Component Analysis (ICA) is a comparatively new statisticaland computational technique to find hidden components from multivariate statistical data. The technique is also employed as a tool for dimension reduction for efficient data analysis. Reduction in dimensions can be done byassigning ranks to the independent components in some appropriate way and then restricting the data analysis to certain high ranking components only.The problem of determining the number of high ranked ICs that should be retained is the main objective of this paper. A method based upon adjusted coefficient of determination is proposed for the purpose. The performance of the proposed method is demonstrated through experimental evaluation on real-world financial time series data.
{"title":"On the Number of Independent Components: An Adjusted Coefficient of Determination based Approach","authors":"Saima Afzal, M. Iqbal, Ayesha Afzal","doi":"10.1285/I20705948V14N1P13","DOIUrl":"https://doi.org/10.1285/I20705948V14N1P13","url":null,"abstract":"Independent Component Analysis (ICA) is a comparatively new statisticaland computational technique to find hidden components from multivariate statistical data. The technique is also employed as a tool for dimension reduction for efficient data analysis. Reduction in dimensions can be done byassigning ranks to the independent components in some appropriate way and then restricting the data analysis to certain high ranking components only.The problem of determining the number of high ranked ICs that should be retained is the main objective of this paper. A method based upon adjusted coefficient of determination is proposed for the purpose. The performance of the proposed method is demonstrated through experimental evaluation on real-world financial time series data.","PeriodicalId":44770,"journal":{"name":"Electronic Journal of Applied Statistical Analysis","volume":"14 1","pages":"13-26"},"PeriodicalIF":0.7,"publicationDate":"2021-05-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49063891","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-05-20DOI: 10.1285/I20705948V14N1P146
Annalisa Levante, S. Petrocchi, F. Lecciso
The study evaluated the stability over time of the Q-CHAT (i.e., Quantitative-CHecklist for Autism in Toddler), a screening tool for the early detection of Autism. The Q-CHAT is filled by parents when the child is from 18-36 months old, and whether a risk score is found, the clinician refers the child to a more in-depth diagnostic evaluation. Previous studies demonstrated the measure test-retest reliability on a small time interval (1-6 months). Therefore, the present study tested the stability of the scores considering a larger time interval of 18 months. No previous studies have tested its measurement invariance over time. Since the tool is filled by parents during a large time span (18-36 months of life), it is imperative to understand whether there is an invariance over time in their evaluations. The Italian version of the Q-CHAT was completed by 282 parents of children with no pre-existing signs of risk of Autism. The Q-CHAT was administered when children were 18 months (T1) and then 18 months later (T2). The intraclass correlation coefficients for the test-retest reliability ranged from sufficient to moderate. The measurement invariance across time revealed a tolerable configural and metric invariance. Contrary, the scalar invariance was not met meaning that the means of the constructs are not invariant over time. The findings give a further demonstration of the reliability of the Q-CHAT. They give evidence that changes in the scores would reflect real changes in the construct itself, and not in the way individuals interpret the measure items.
{"title":"Test-retest Reliability and Measurement Invariance across time of the Quantitative-CHecklist for Autism in Toddler","authors":"Annalisa Levante, S. Petrocchi, F. Lecciso","doi":"10.1285/I20705948V14N1P146","DOIUrl":"https://doi.org/10.1285/I20705948V14N1P146","url":null,"abstract":"The study evaluated the stability over time of the Q-CHAT (i.e., Quantitative-CHecklist for Autism in Toddler), a screening tool for the early detection of Autism. The Q-CHAT is filled by parents when the child is from 18-36 months old, and whether a risk score is found, the clinician refers the child to a more in-depth diagnostic evaluation. Previous studies demonstrated the measure test-retest reliability on a small time interval (1-6 months). Therefore, the present study tested the stability of the scores considering a larger time interval of 18 months. No previous studies have tested its measurement invariance over time. Since the tool is filled by parents during a large time span (18-36 months of life), it is imperative to understand whether there is an invariance over time in their evaluations. The Italian version of the Q-CHAT was completed by 282 parents of children with no pre-existing signs of risk of Autism. The Q-CHAT was administered when children were 18 months (T1) and then 18 months later (T2). The intraclass correlation coefficients for the test-retest reliability ranged from sufficient to moderate. The measurement invariance across time revealed a tolerable configural and metric invariance. Contrary, the scalar invariance was not met meaning that the means of the constructs are not invariant over time. The findings give a further demonstration of the reliability of the Q-CHAT. They give evidence that changes in the scores would reflect real changes in the construct itself, and not in the way individuals interpret the measure items.","PeriodicalId":44770,"journal":{"name":"Electronic Journal of Applied Statistical Analysis","volume":"14 1","pages":"146-166"},"PeriodicalIF":0.7,"publicationDate":"2021-05-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48444732","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-05-20DOI: 10.1285/I20705948V14N1P167
A. Al-Omari, SidAhmed Benchiha
In this paper, we introduce a new continuous distribution of two parameterscalled as a generalized Quasi Lindley distribution (GQLD). The GQLD is asum of two independent Quasi Lindley distributed random variables. Compre-hensive statistical properties of the GQLD are provided in closed forms includesmoments, reliability analysis, stochastic ordering, stress-strength reliability, andthe distribution of order statistics. The parameters of the new distribution areestimated by the maximum likelihood, maximum product of spacings, ordinaryleast squares, weighted least squares, Cramer-von-Mises, and Anderson-Darlingmethods are considered. A simulation study is conducted to investigate theeciency of the proposed estimators and applications to real data sets are pro-vided.
{"title":"Generalized Quasi Lindley Distribution: Theoretical Properties, Estimation Methods, and Applications","authors":"A. Al-Omari, SidAhmed Benchiha","doi":"10.1285/I20705948V14N1P167","DOIUrl":"https://doi.org/10.1285/I20705948V14N1P167","url":null,"abstract":"In this paper, we introduce a new continuous distribution of two parameterscalled as a generalized Quasi Lindley distribution (GQLD). The GQLD is asum of two independent Quasi Lindley distributed random variables. Compre-hensive statistical properties of the GQLD are provided in closed forms includesmoments, reliability analysis, stochastic ordering, stress-strength reliability, andthe distribution of order statistics. The parameters of the new distribution areestimated by the maximum likelihood, maximum product of spacings, ordinaryleast squares, weighted least squares, Cramer-von-Mises, and Anderson-Darlingmethods are considered. A simulation study is conducted to investigate theeciency of the proposed estimators and applications to real data sets are pro-vided.","PeriodicalId":44770,"journal":{"name":"Electronic Journal of Applied Statistical Analysis","volume":"14 1","pages":"167-196"},"PeriodicalIF":0.7,"publicationDate":"2021-05-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42762421","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-05-20DOI: 10.1285/I20705948V14N1P266
Ahmed Alkhateeb, Z. Algamal
Variable selection is a very helpful procedure for improving computational speed and prediction accuracy by identifying the most important variables that related to the response variable. Regression modeling has received much attention in several science fields. Firefly algorithm is one of the recently efficient proposed nature-inspired algorithms that can efficiently be employed for variable selection. In this work, chaotic firefly algorithm is proposed to perform variable selection for gamma regression model. A real data application related to the chemometrics is conducted to evaluate the performance of the proposed method in terms of prediction accuracy and variable selection criteria. Further, its performance is compared with other methods. The results proved the efficiency of our proposed methods and it outperforms other popular methods.
{"title":"Variable selection in gamma regression model using chaotic firefly algorithm with application in chemometrics","authors":"Ahmed Alkhateeb, Z. Algamal","doi":"10.1285/I20705948V14N1P266","DOIUrl":"https://doi.org/10.1285/I20705948V14N1P266","url":null,"abstract":"Variable selection is a very helpful procedure for improving computational speed and prediction accuracy by identifying the most important variables that related to the response variable. Regression modeling has received much attention in several science fields. Firefly algorithm is one of the recently efficient proposed nature-inspired algorithms that can efficiently be employed for variable selection. In this work, chaotic firefly algorithm is proposed to perform variable selection for gamma regression model. A real data application related to the chemometrics is conducted to evaluate the performance of the proposed method in terms of prediction accuracy and variable selection criteria. Further, its performance is compared with other methods. The results proved the efficiency of our proposed methods and it outperforms other popular methods.","PeriodicalId":44770,"journal":{"name":"Electronic Journal of Applied Statistical Analysis","volume":"14 1","pages":"266-276"},"PeriodicalIF":0.7,"publicationDate":"2021-05-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48924762","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-05-20DOI: 10.1285/I20705948V14N1P58
Byron Quito, Pablo Ponce, M. C. D. Río-Rama, J. Álvarez‐García
From the empirical point of view, measures that promote work flexibility increase income inequalities and unemployment rates in the long-term, as well as promoting employment precariousness and the informality of the labor sector. The objective of the present work is to investigate the effect on wage inequality of eliminating work flexibility, which was undertaken in Ecuador in 2008. A two-way effect econometric model was applied with panel data. Data from the 21 provinces of Ecuador covering the period of 2007-2018 were obtained from the National Employment, Unemployment and Under-Employment Survey (ENEMDU) of the National Statistical and Census Institute (INEC). The results suggest that the elimination of work flexibility had a significant and negative effect on inequality; the policy was effective in reducing inequality. This result is significant for all the years subsequent to the introduction of these measures, although with variations according to regional and economic characteristics. Policies aimed at reducing inequality should focus on improving workers' bargaining power and on generating an environment that favors increasing levels of formality.
{"title":"Does the elimination of work flexibility contribute to reducing wage inequality? Empirical evidence from Ecuador","authors":"Byron Quito, Pablo Ponce, M. C. D. Río-Rama, J. Álvarez‐García","doi":"10.1285/I20705948V14N1P58","DOIUrl":"https://doi.org/10.1285/I20705948V14N1P58","url":null,"abstract":"From the empirical point of view, measures that promote work flexibility increase income inequalities and unemployment rates in the long-term, as well as promoting employment precariousness and the informality of the labor sector. The objective of the present work is to investigate the effect on wage inequality of eliminating work flexibility, which was undertaken in Ecuador in 2008. A two-way effect econometric model was applied with panel data. Data from the 21 provinces of Ecuador covering the period of 2007-2018 were obtained from the National Employment, Unemployment and Under-Employment Survey (ENEMDU) of the National Statistical and Census Institute (INEC). The results suggest that the elimination of work flexibility had a significant and negative effect on inequality; the policy was effective in reducing inequality. This result is significant for all the years subsequent to the introduction of these measures, although with variations according to regional and economic characteristics. Policies aimed at reducing inequality should focus on improving workers' bargaining power and on generating an environment that favors increasing levels of formality.","PeriodicalId":44770,"journal":{"name":"Electronic Journal of Applied Statistical Analysis","volume":"14 1","pages":"58-77"},"PeriodicalIF":0.7,"publicationDate":"2021-05-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46408562","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-05-20DOI: 10.1285/I20705948V14N1P44
F. Noeel, Z. Algamal
The ridge estimator has been consistently demonstrated to be an attractive shrinkage method to reduce the effects of multicollinearity. The Poisson regression negative binomial regression models are well-known model in application when the response variable is count data. However, it is known that multicollinearity negatively affects the variance of maximum likelihood estimator of the count regression coefficients. To address this problem, a count data ridge estimator has been proposed by numerous researchers. In this paper, an almost unbiased regression estimator is proposed and derived. Our Monte Carlo simulation results suggest that the proposed estimator can bring significant improvement relative to other existing estimators. In addition, the real application results demonstrate that the proposed estimator outperforms both negative binomial ridge regression and maximum likelihood estimators in terms of predictive performance.
{"title":"Almost unbiased ridge estimator in the count data regression models","authors":"F. Noeel, Z. Algamal","doi":"10.1285/I20705948V14N1P44","DOIUrl":"https://doi.org/10.1285/I20705948V14N1P44","url":null,"abstract":"The ridge estimator has been consistently demonstrated to be an attractive shrinkage method to reduce the effects of multicollinearity. The Poisson regression negative binomial regression models are well-known model in application when the response variable is count data. However, it is known that multicollinearity negatively affects the variance of maximum likelihood estimator of the count regression coefficients. To address this problem, a count data ridge estimator has been proposed by numerous researchers. In this paper, an almost unbiased regression estimator is proposed and derived. Our Monte Carlo simulation results suggest that the proposed estimator can bring significant improvement relative to other existing estimators. In addition, the real application results demonstrate that the proposed estimator outperforms both negative binomial ridge regression and maximum likelihood estimators in terms of predictive performance.","PeriodicalId":44770,"journal":{"name":"Electronic Journal of Applied Statistical Analysis","volume":"14 1","pages":"44-57"},"PeriodicalIF":0.7,"publicationDate":"2021-05-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44638896","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-05-20DOI: 10.1285/I20705948V14N1P1
Kengo Fujisawa, Jin Kinoshita, Kouji Tahata
The issues of symmetry (or asymmetry) arises naturally for the analysis of square contingency tables. Many existing asymmetry models do not have the constraints on the main diagonal cells. Thus, the observations on the main diagonal cells do not contribute to the likelihood ratio chi-squared test statistics. Herein we propose a model that indicates the asymmetry for the log odds.It can utilize the information in the main diagonal cells. Also, the symmetry model is separated into some models including the proposed model.
{"title":"Extended asymmetry model based on logit transformation and decomposition of symmetry for square contingency tables with ordered categories","authors":"Kengo Fujisawa, Jin Kinoshita, Kouji Tahata","doi":"10.1285/I20705948V14N1P1","DOIUrl":"https://doi.org/10.1285/I20705948V14N1P1","url":null,"abstract":"The issues of symmetry (or asymmetry) arises naturally for the analysis of square contingency tables. Many existing asymmetry models do not have the constraints on the main diagonal cells. Thus, the observations on the main diagonal cells do not contribute to the likelihood ratio chi-squared test statistics. Herein we propose a model that indicates the asymmetry for the log odds.It can utilize the information in the main diagonal cells. Also, the symmetry model is separated into some models including the proposed model.","PeriodicalId":44770,"journal":{"name":"Electronic Journal of Applied Statistical Analysis","volume":"14 1","pages":"1-12"},"PeriodicalIF":0.7,"publicationDate":"2021-05-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42063192","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-05-20DOI: 10.1285/I20705948V14N1P217
Abedel-Qader Al-Masri, Noor Al-Momani
Bahadur's stochastic comparison of asymptotic relative efficiency of combining infinitely independent tests in case of log-logistic distribution is proposed. Six free-distribution combination producers namely; Fisher, logistic, sum of p-values, inverse normal, Tippett's method and maximum of p-values were studied. Several comparisons among the six procedures using the exact Bahadur's slopes were obtained. These non-parametric procedures depend on the p-value of the individual tests combined.
{"title":"On Combining Independent Tests In Case Of Log-Logistic Distribution","authors":"Abedel-Qader Al-Masri, Noor Al-Momani","doi":"10.1285/I20705948V14N1P217","DOIUrl":"https://doi.org/10.1285/I20705948V14N1P217","url":null,"abstract":"Bahadur's stochastic comparison of asymptotic relative efficiency of combining infinitely independent tests in case of log-logistic distribution is proposed. Six free-distribution combination producers namely; Fisher, logistic, sum of p-values, inverse normal, Tippett's method and maximum of p-values were studied. Several comparisons among the six procedures using the exact Bahadur's slopes were obtained. These non-parametric procedures depend on the p-value of the individual tests combined.","PeriodicalId":44770,"journal":{"name":"Electronic Journal of Applied Statistical Analysis","volume":"14 1","pages":"217-229"},"PeriodicalIF":0.7,"publicationDate":"2021-05-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48734278","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-05-20DOI: 10.1285/i20705948v14n1p197
I. Keser, Ipek Deveci Kocakoç
The danger of a global pandemic, such as the new Coronavirus (Covid-19),is obvious. This study aims to investigate the behavior and relationship of thenumber of daily new conrmed deaths per million and the stringency indexof twenty-seven European Union (EU) countries by utilizing functional clusteranalysis and functional canonical correlation analysis. Functional clusteranalysis was used to observe how countries cluster together according to dailydeaths during the time interval between March and July 2020. Functionalcanonical correlation analysis was also utilized to measure the correlationbetween the frequency index and daily deaths, and also to determine therelative positions of countries concerning their respective variability structure.The data is obtained from OWID. Here, it is seen that Italy, Spain,Belgium, and France are particularly aected by the pandemic during thetime interval within the EU countries, and the course of daily deaths is in adierent position compared to other EU countries. At the same time, a veryhigh relationship emerged between the stringency index and daily deaths asexpected.
{"title":"Functional cluster and canonical correlation analysis of EU countries by number of daily deaths and stringency index during Covid-19 pandemic","authors":"I. Keser, Ipek Deveci Kocakoç","doi":"10.1285/i20705948v14n1p197","DOIUrl":"https://doi.org/10.1285/i20705948v14n1p197","url":null,"abstract":"The danger of a global pandemic, such as the new Coronavirus (Covid-19),is obvious. This study aims to investigate the behavior and relationship of thenumber of daily new conrmed deaths per million and the stringency indexof twenty-seven European Union (EU) countries by utilizing functional clusteranalysis and functional canonical correlation analysis. Functional clusteranalysis was used to observe how countries cluster together according to dailydeaths during the time interval between March and July 2020. Functionalcanonical correlation analysis was also utilized to measure the correlationbetween the frequency index and daily deaths, and also to determine therelative positions of countries concerning their respective variability structure.The data is obtained from OWID. Here, it is seen that Italy, Spain,Belgium, and France are particularly aected by the pandemic during thetime interval within the EU countries, and the course of daily deaths is in adierent position compared to other EU countries. At the same time, a veryhigh relationship emerged between the stringency index and daily deaths asexpected.","PeriodicalId":44770,"journal":{"name":"Electronic Journal of Applied Statistical Analysis","volume":"14 1","pages":"197-216"},"PeriodicalIF":0.7,"publicationDate":"2021-05-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46465931","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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