The spatial distribution of overburden layer thickness(OLT)is crucial for landslide susceptibility prediction and slope stability analysis.Due to OLT spatial heterogeneity in hillslope regions,combined with the diffic...The spatial distribution of overburden layer thickness(OLT)is crucial for landslide susceptibility prediction and slope stability analysis.Due to OLT spatial heterogeneity in hillslope regions,combined with the difficulty and time consumption of OLT sample collection,accurately predicting OLT distribution remains a challenging.To address this,a novel framework has been developed.First,OLT samples are collected through field surveys,remote sensing,and geological drilling.Next,the heterogeneity of OLT’s spatial distribution is analyzed using the probability distribution of OLT samples and their horizontal and vertical distributions.The OLT samples are categorized and the small sample categories are expanded using the synthetic minority over-sampling technique(SMOTE).The slope position is selected as a key conditioning factor.Subsequently,16 conditioning factors are applied to construct OLT prediction model using the random forest regression algorithm.Weights are assigned to each OLT sample category to balance the uneven distribution of sample sizes.Finally,the Pearson correlation coefficient,mean absolute error(MAE),root mean square error(RMSE),and Lin’s concordance correlation coefficient(Lin’s CCC)are employed to validate the OLT prediction results.The Huangtan town serves as the case study.Results show:(1)heterogeneity analysis,SMOTE-based OLT sample expansion strategy and slope position selection can significantly mitigate the effect of spatial heterogeneity on OLT prediction.(2)The Pearson correlation coefficient,RMSE,MAE and Lin’s CCC values are 0.84,1.173,1.378 and 0.804,respectively,indicating excellent prediction performance.This research provides an effective solution for predicting OLT distribution in hillslope regions.展开更多
Mesoscale drag model is of crucial significance for the reliability and accuracy in coarse-grid EulerianEulerian two-fluid model(TFM)simulations of gas-solid flow hydrodynamics in fluidized bed reactors.Although numer...Mesoscale drag model is of crucial significance for the reliability and accuracy in coarse-grid EulerianEulerian two-fluid model(TFM)simulations of gas-solid flow hydrodynamics in fluidized bed reactors.Although numerous mesoscale drag models have been reported in the literature,a systematic comparison of their prediction capability from the perspective of heterogeneity analysis is still lacking.In this study,in order to investigate the effect of several typical drag models on the hydrodynamic behaviors,the nonuniformity analysis and the sensitivity to material properties,extensive coarse-grid TFM simulations of a bubbling pilot-scale fluidized bed reactor are carried out.The results demonstrate that the mesoscale drag models outperform the empirical drag model in terms of nonuniformity due to the consideration of the influence of the mesoscale structures on the drag force in the bubbling region.Furthermore,the results reveal that our previously developed three-marker gradient-based drag model considering the solid concentration gradient exhibits satisfactory performance in predicting the bubbling flow hydrodynamics.Besides,the material-property-dependent drag model considering the explicit effect of material properties on drag corrections is most sensitive to the particle diameter.This work provides guideline for possible future improvements of mesoscale models to simulate gas-solid flow more accurately and universally.展开更多
ESG(Environmental,Social,and Governance)performance has emerged as a central metric in assessing corporate sustainability.Utilizing ESG rating data for A-share listed companies on the Shanghai Stock Exchange spanning ...ESG(Environmental,Social,and Governance)performance has emerged as a central metric in assessing corporate sustainability.Utilizing ESG rating data for A-share listed companies on the Shanghai Stock Exchange spanning from 2019 to 2022,coupled with measures of corporate transformation and upgrading,this study introduces green innovation as a mediating variable to dissect the impact of ESG ratings on corporate transformation and upgrading.The key findings of this research are as follows:(1)ESG ratings positively influence corporate transformation and upgrading,a conclusion that retains robustness after a comprehensive series of tests and discussions on endogeneity.(2)Mechanism analysis reveals that ESG ratings foster corporate transformation and upgrading by enhancing corporate green innovation.(3)In comparison with other industries,the influence of ESG ratings on corporate transformation and upgrading is notably more pronounced among heavily polluting industries among listed companies in China.Additionally,ESG ratings exhibit a more significant promotional effect on non-state-owned enterprises compared to state-owned enterprises.Larger enterprises play a more substantial role in transformation and upgrading than small and medium-sized enterprises.The promotional effect of ESG ratings is more evident in enterprises with poor information disclosure quality.Furthermore,as media attention increases,so does the impact of ESG ratings on corporate transformation.This study offers valuable policy insights from the ESG rating perspective,aiming to propel corporate transformation and upgrading,thereby contributing to economic high-quality and sustainable development.展开更多
Objective This study aimed to explore the spatial heterogeneity and risk factors for dental caries in 12-year-old children in Shanxi province,China.Methods The data encompassed 3,721 participants from the two most rec...Objective This study aimed to explore the spatial heterogeneity and risk factors for dental caries in 12-year-old children in Shanxi province,China.Methods The data encompassed 3,721 participants from the two most recent oral health surveys conducted across 16 districts in Shanxi Province in 2015 and 2018.Eighteen specific variables were analyzed to examine the interplay between socioeconomic factors,medical resources and environmental conditions.The Geo-detector model was employed to assess the impacts and interactions of these ecological factors.Results Socioeconomic factors(Q=0.30,P<0.05)exhibited a more substantial impact compared to environmental(Q=0.19,P<0.05)and medical resource factors(Q=0.25,P<0.05).Notably,the urban population percentage(UPP)demonstrated the most significant explanatory power for the spatial heterogeneity in caries prevalence,as denoted by its highest q-value(q=0.51,P<0.05).Additionally,the spatial distribution’s heterogeneity of caries was significantly affected by SO2 concentration(q=0.39,P<0.05)and water fluoride levels(q=0.27,P<0.05)among environmental factors.Conclusion The prevalence of caries exhibited spatial heterogeneity,escalating from North to South in Shanxi Province,China,influenced by socioeconomic factors,medical resources,and environmental conditions to varying extents.展开更多
This study determines whether industrial agglomeration can solve energy poverty(ENPO)by applying a provincial dataset(2002-2019)to assess the potential effect of industrial agglomeration on ENPO.Additionally,this stud...This study determines whether industrial agglomeration can solve energy poverty(ENPO)by applying a provincial dataset(2002-2019)to assess the potential effect of industrial agglomeration on ENPO.Additionally,this study conducts an in-depth exploration of provincial heterogeneity and its influence mechanisms.The conclusions are as follows:①Industrial agglomeration is negatively correlated with ENPO;by implication,enhancing industrial agglomeration is a driving force for reducing ENPO.②The alleviating effect of industrial agglomeration on ENPO in the midwestern region is considerably higher than that in the eastern region,and the ENPO alleviation effect of the high agglomeration region is better than that in the low agglomeration region.③Foreign investment and energy efficiency have a mediating role,that is,they are valid transmission pathways for industrial agglomeration to solve the ENPO issue.Relevant policy suggestions for reducing ENPO by accelerating industrial agglomeration are proposed by drawing on the above three conclusions.展开更多
With China entering the stage of high-quality development,the issue of carbon emission has become a hot research topic.This paper analyzes the different temporal and spatial effects of per capita income on household i...With China entering the stage of high-quality development,the issue of carbon emission has become a hot research topic.This paper analyzes the different temporal and spatial effects of per capita income on household indirect carbon emissions in western China.Based on the data of Chinese Family Panel Studies(CFPS)in 2016 and 2018 in the western China,this paper uses Regression analysis and Bayesian correlation analysis to study the relationship between per capita income and household indirect carbon emissions.The results showed that the indirect carbon emissions generated by the expenditure on food,housing and household equipment in the household consumption structure in the western China were relatively high.In 2016-2018,the per capita income and per capita household consumption indirect carbon emissions in the western China showed an increasing trend.There was a positive correlation between per capita income and indirect carbon emissions of per capita household consumption,and its correlation was gradually enhanced in time dimension.In the spatial dimension,the household indirect carbon emissions in Yunnan,Qinghai,Guangxi Zhuang and Ningxia in the western China were greatly affected by per capita income,while the household indirect carbon emissions in Guizhou was least affected by per capita income.Finally,the paper puts forward some problems that we should consider in the process of facing the per capita income growth and climate change:the collection of carbon tax,the optimization of household consumption structure,the research and development of low-carbon products,and the differentiated carbon reduction.展开更多
It is becoming more and more common in modern life that people forget words when they write. Based on the Logistics model, this study conducts a systematic empirical analysis on the influencing factors and heterogenei...It is becoming more and more common in modern life that people forget words when they write. Based on the Logistics model, this study conducts a systematic empirical analysis on the influencing factors and heterogeneity of this phenomenon through a questionnaire survey of college students in Kaifeng City, He’nan Province. The results show that students professional differences, Chinese character use habits, environmental edification and attitude towards this phenomenon have an effect of 2.2%~5.4%. The higher the frequency of learning and output using electronic devices, the more likely it is that the phenomenon of character amnesia will appear. Moreover, this effect has both gender and grade heterogeneity.展开更多
Contrast-enhanced computed tomography(CT)contributes to the increasing detection of pancreatic neuroendocrine neoplasms(PNENs).Nevertheless,its value for differentiating pathological tumor grades is not well recognize...Contrast-enhanced computed tomography(CT)contributes to the increasing detection of pancreatic neuroendocrine neoplasms(PNENs).Nevertheless,its value for differentiating pathological tumor grades is not well recognized.In this report,we have conducted a retrospective study on the relationship between the 2017 World Health Organization(WHO)classification and CT imaging features in 94 patients.Most of the investigated features eventually provided statistically significant indicators for discerning PNENs G3 from PNENs G1/G2,including tumor size,shape,margin,heterogeneity,intratumoral blood vessels,vascular invasion,enhancement pattern in both contrast phases,enhancement degree in both phases,tumor-to-pancreas contrast ratio in both phases,common bile duct dilatation,lymph node metastases,and liver metastases.Ill-defined tumor margin was an independent predictor for PNENs G3 with the highest area under the curve(AUC)of 0.906 in the multivariable logistic regression and receiver operating characteristic curve analysis.The portal enhancement ratio(PER)was shown the highest AUC of 0.855 in terms of quantitative features.Our data suggest that the traditional contrastenhanced CT still plays a vital role in differentiation of tumor grades and heterogeneity analysis prior to treatment.展开更多
Objective This study was designed to investigate the prognostic implications of the intertumoral heterogeneity of molecular phenotype in multifocal and multicentric breast cancer(MMBC).Methods The clinical and follow-...Objective This study was designed to investigate the prognostic implications of the intertumoral heterogeneity of molecular phenotype in multifocal and multicentric breast cancer(MMBC).Methods The clinical and follow-up data of 146 patients with MMBC from Jan.2009to Dec.2009 treated in Tumor Hospital Affiliated to Zhengzhou University were retrospectively analyzed.展开更多
Metabolic homeostasis is regulated by a network of organs and tissues,primarily involving adipose tissue,muscle,liver,and the hypothalamus,which act as central metabolic regulators.Cellular dysregulation within these ...Metabolic homeostasis is regulated by a network of organs and tissues,primarily involving adipose tissue,muscle,liver,and the hypothalamus,which act as central metabolic regulators.Cellular dysregulation within these tissues substantially associates with metabolic disorders,including obesity,type 2 diabetes,and non-alcoholic fatty liver disease(NAFLD)[1].Understanding the molecular mechanisms governing metabolic control requires dedicated analysis of physiological and pathological cellular heterogeneity within these tissues.However,investigations at the single cell level to decipher the complexities of cellular mechanisms remain challenging due to the fragile nature of certain cell types and technical noise within these metabolically active tissues,resulting in limited studies compared to well-characterized atlases in immune cell populations[2].展开更多
It is challenging and significant to explore the impacts of non-real-time services on real-time services from the perspective of jitter. Most of current researches on jitter made too many mathematical hypotheses on ne...It is challenging and significant to explore the impacts of non-real-time services on real-time services from the perspective of jitter. Most of current researches on jitter made too many mathematical hypotheses on networks and traffic. This paper puts forward a tandem queuing model to characterize the real communication scenario where heterogeneous services are served by IEEE 802.15.4 wireless sensor networks（WSNs）, and then the packets served successfully are fed to Internet protocol（IP） networks. By analyzing the contention access processes in IEEE 802.15.4 WSNs, the authors derive the departure processes of the two types of services, i.e., the arrival processes of IP networks. The IP network is modeled as a queuing system, in which the real-time service is forwarded accompanied by the non-real-time service. Investigating the jitter of real-time services is intractable. Therefore, this paper abstracts this problem as a dynamic queuing system evolving on a dynamic time interval. Referring the transient analysis method（TAM）, this paper obtains the queue length in a random time interval which is scaled by the arrival of real-time services. Queue length evolution is closely connected with the jitter. Benefiting from the derivation in probability generation domain, the jitter of real-time services is obtained.展开更多
Media inclinations,whether favorable or biased,play a pivotal role in shaping public opinion.Sometimes,media coverage may unintentionally foster skepticism towards foreign firms,which could create challenges for those...Media inclinations,whether favorable or biased,play a pivotal role in shaping public opinion.Sometimes,media coverage may unintentionally foster skepticism towards foreign firms,which could create challenges for those companies when they enter new markets.Based on a panel dataset from 2005 to 2020,this is one of the first studies to investigate empirically the impact of media opinion on outward foreign direct investment(OFDI)behaviors at the firm level.The media inclination index was constructed according to the varying inclinations of media from different countries in their reporting on each event.We examined the impact of media inclination on the investment value,frequency,and number of industries.This study has revealed the following insights:(i)Positive media coverage can stimulate the investment behavior of Chinese firms.(ii)The heterogeneity analysis indicates that the promotional effect of media reporting inclination on OFDI is more significant for state-owned firms from the investor's perspective and especially pronounced for firms in developing countries from the investee's perspective.(iii)Diplomatic visits and scientific research cooperation can amplify the positive impact of media opinions on the OFDI behaviors of Chinese firms.展开更多
基金funded by the Natural Science Foundation of China(No.42407241,42272326 and 52222905)Jiangxi Provincial Natural Science Foundation(Nos.20242BAB20241,20242BAB23052 and 20242BAB24001).
文摘The spatial distribution of overburden layer thickness(OLT)is crucial for landslide susceptibility prediction and slope stability analysis.Due to OLT spatial heterogeneity in hillslope regions,combined with the difficulty and time consumption of OLT sample collection,accurately predicting OLT distribution remains a challenging.To address this,a novel framework has been developed.First,OLT samples are collected through field surveys,remote sensing,and geological drilling.Next,the heterogeneity of OLT’s spatial distribution is analyzed using the probability distribution of OLT samples and their horizontal and vertical distributions.The OLT samples are categorized and the small sample categories are expanded using the synthetic minority over-sampling technique(SMOTE).The slope position is selected as a key conditioning factor.Subsequently,16 conditioning factors are applied to construct OLT prediction model using the random forest regression algorithm.Weights are assigned to each OLT sample category to balance the uneven distribution of sample sizes.Finally,the Pearson correlation coefficient,mean absolute error(MAE),root mean square error(RMSE),and Lin’s concordance correlation coefficient(Lin’s CCC)are employed to validate the OLT prediction results.The Huangtan town serves as the case study.Results show:(1)heterogeneity analysis,SMOTE-based OLT sample expansion strategy and slope position selection can significantly mitigate the effect of spatial heterogeneity on OLT prediction.(2)The Pearson correlation coefficient,RMSE,MAE and Lin’s CCC values are 0.84,1.173,1.378 and 0.804,respectively,indicating excellent prediction performance.This research provides an effective solution for predicting OLT distribution in hillslope regions.
文摘Mesoscale drag model is of crucial significance for the reliability and accuracy in coarse-grid EulerianEulerian two-fluid model(TFM)simulations of gas-solid flow hydrodynamics in fluidized bed reactors.Although numerous mesoscale drag models have been reported in the literature,a systematic comparison of their prediction capability from the perspective of heterogeneity analysis is still lacking.In this study,in order to investigate the effect of several typical drag models on the hydrodynamic behaviors,the nonuniformity analysis and the sensitivity to material properties,extensive coarse-grid TFM simulations of a bubbling pilot-scale fluidized bed reactor are carried out.The results demonstrate that the mesoscale drag models outperform the empirical drag model in terms of nonuniformity due to the consideration of the influence of the mesoscale structures on the drag force in the bubbling region.Furthermore,the results reveal that our previously developed three-marker gradient-based drag model considering the solid concentration gradient exhibits satisfactory performance in predicting the bubbling flow hydrodynamics.Besides,the material-property-dependent drag model considering the explicit effect of material properties on drag corrections is most sensitive to the particle diameter.This work provides guideline for possible future improvements of mesoscale models to simulate gas-solid flow more accurately and universally.
文摘ESG(Environmental,Social,and Governance)performance has emerged as a central metric in assessing corporate sustainability.Utilizing ESG rating data for A-share listed companies on the Shanghai Stock Exchange spanning from 2019 to 2022,coupled with measures of corporate transformation and upgrading,this study introduces green innovation as a mediating variable to dissect the impact of ESG ratings on corporate transformation and upgrading.The key findings of this research are as follows:(1)ESG ratings positively influence corporate transformation and upgrading,a conclusion that retains robustness after a comprehensive series of tests and discussions on endogeneity.(2)Mechanism analysis reveals that ESG ratings foster corporate transformation and upgrading by enhancing corporate green innovation.(3)In comparison with other industries,the influence of ESG ratings on corporate transformation and upgrading is notably more pronounced among heavily polluting industries among listed companies in China.Additionally,ESG ratings exhibit a more significant promotional effect on non-state-owned enterprises compared to state-owned enterprises.Larger enterprises play a more substantial role in transformation and upgrading than small and medium-sized enterprises.The promotional effect of ESG ratings is more evident in enterprises with poor information disclosure quality.Furthermore,as media attention increases,so does the impact of ESG ratings on corporate transformation.This study offers valuable policy insights from the ESG rating perspective,aiming to propel corporate transformation and upgrading,thereby contributing to economic high-quality and sustainable development.
基金supported by scientific research project of the Health Commission of Shanxi Province[NO.2018104]Science and Technology Innovation Project of Shanxi Province[NO.2020L0217 and 2022L172]+1 种基金Key Research and Development Projects of Shanxi Province[NO.A2021-113]Chinese Stomatological Association Dental Doctors Caries Prevention Ability Improvement Project[NO.CSA-ICP2022-05].
文摘Objective This study aimed to explore the spatial heterogeneity and risk factors for dental caries in 12-year-old children in Shanxi province,China.Methods The data encompassed 3,721 participants from the two most recent oral health surveys conducted across 16 districts in Shanxi Province in 2015 and 2018.Eighteen specific variables were analyzed to examine the interplay between socioeconomic factors,medical resources and environmental conditions.The Geo-detector model was employed to assess the impacts and interactions of these ecological factors.Results Socioeconomic factors(Q=0.30,P<0.05)exhibited a more substantial impact compared to environmental(Q=0.19,P<0.05)and medical resource factors(Q=0.25,P<0.05).Notably,the urban population percentage(UPP)demonstrated the most significant explanatory power for the spatial heterogeneity in caries prevalence,as denoted by its highest q-value(q=0.51,P<0.05).Additionally,the spatial distribution’s heterogeneity of caries was significantly affected by SO2 concentration(q=0.39,P<0.05)and water fluoride levels(q=0.27,P<0.05)among environmental factors.Conclusion The prevalence of caries exhibited spatial heterogeneity,escalating from North to South in Shanxi Province,China,influenced by socioeconomic factors,medical resources,and environmental conditions to varying extents.
基金sponsored by the National Social Science Fund of China[Grant No.23VMG006].
文摘This study determines whether industrial agglomeration can solve energy poverty(ENPO)by applying a provincial dataset(2002-2019)to assess the potential effect of industrial agglomeration on ENPO.Additionally,this study conducts an in-depth exploration of provincial heterogeneity and its influence mechanisms.The conclusions are as follows:①Industrial agglomeration is negatively correlated with ENPO;by implication,enhancing industrial agglomeration is a driving force for reducing ENPO.②The alleviating effect of industrial agglomeration on ENPO in the midwestern region is considerably higher than that in the eastern region,and the ENPO alleviation effect of the high agglomeration region is better than that in the low agglomeration region.③Foreign investment and energy efficiency have a mediating role,that is,they are valid transmission pathways for industrial agglomeration to solve the ENPO issue.Relevant policy suggestions for reducing ENPO by accelerating industrial agglomeration are proposed by drawing on the above three conclusions.
基金supported by the National Natural Science Foundation of China(Grant No.72264035)。
文摘With China entering the stage of high-quality development,the issue of carbon emission has become a hot research topic.This paper analyzes the different temporal and spatial effects of per capita income on household indirect carbon emissions in western China.Based on the data of Chinese Family Panel Studies(CFPS)in 2016 and 2018 in the western China,this paper uses Regression analysis and Bayesian correlation analysis to study the relationship between per capita income and household indirect carbon emissions.The results showed that the indirect carbon emissions generated by the expenditure on food,housing and household equipment in the household consumption structure in the western China were relatively high.In 2016-2018,the per capita income and per capita household consumption indirect carbon emissions in the western China showed an increasing trend.There was a positive correlation between per capita income and indirect carbon emissions of per capita household consumption,and its correlation was gradually enhanced in time dimension.In the spatial dimension,the household indirect carbon emissions in Yunnan,Qinghai,Guangxi Zhuang and Ningxia in the western China were greatly affected by per capita income,while the household indirect carbon emissions in Guizhou was least affected by per capita income.Finally,the paper puts forward some problems that we should consider in the process of facing the per capita income growth and climate change:the collection of carbon tax,the optimization of household consumption structure,the research and development of low-carbon products,and the differentiated carbon reduction.
文摘It is becoming more and more common in modern life that people forget words when they write. Based on the Logistics model, this study conducts a systematic empirical analysis on the influencing factors and heterogeneity of this phenomenon through a questionnaire survey of college students in Kaifeng City, He’nan Province. The results show that students professional differences, Chinese character use habits, environmental edification and attitude towards this phenomenon have an effect of 2.2%~5.4%. The higher the frequency of learning and output using electronic devices, the more likely it is that the phenomenon of character amnesia will appear. Moreover, this effect has both gender and grade heterogeneity.
基金This study was supported by a grant from the Innovation Capability Development Project of Jiangsu Province(No.BM2015004).
文摘Contrast-enhanced computed tomography(CT)contributes to the increasing detection of pancreatic neuroendocrine neoplasms(PNENs).Nevertheless,its value for differentiating pathological tumor grades is not well recognized.In this report,we have conducted a retrospective study on the relationship between the 2017 World Health Organization(WHO)classification and CT imaging features in 94 patients.Most of the investigated features eventually provided statistically significant indicators for discerning PNENs G3 from PNENs G1/G2,including tumor size,shape,margin,heterogeneity,intratumoral blood vessels,vascular invasion,enhancement pattern in both contrast phases,enhancement degree in both phases,tumor-to-pancreas contrast ratio in both phases,common bile duct dilatation,lymph node metastases,and liver metastases.Ill-defined tumor margin was an independent predictor for PNENs G3 with the highest area under the curve(AUC)of 0.906 in the multivariable logistic regression and receiver operating characteristic curve analysis.The portal enhancement ratio(PER)was shown the highest AUC of 0.855 in terms of quantitative features.Our data suggest that the traditional contrastenhanced CT still plays a vital role in differentiation of tumor grades and heterogeneity analysis prior to treatment.
文摘Objective This study was designed to investigate the prognostic implications of the intertumoral heterogeneity of molecular phenotype in multifocal and multicentric breast cancer(MMBC).Methods The clinical and follow-up data of 146 patients with MMBC from Jan.2009to Dec.2009 treated in Tumor Hospital Affiliated to Zhengzhou University were retrospectively analyzed.
基金funded by the National Key Research and Development Program of China (2024YFA1802800 and 2024YFA1802803)the National Natural Science Foundation of China (32371195)a new PI Start up grant of Fudan University (JIH2303132Y) to G.W
文摘Metabolic homeostasis is regulated by a network of organs and tissues,primarily involving adipose tissue,muscle,liver,and the hypothalamus,which act as central metabolic regulators.Cellular dysregulation within these tissues substantially associates with metabolic disorders,including obesity,type 2 diabetes,and non-alcoholic fatty liver disease(NAFLD)[1].Understanding the molecular mechanisms governing metabolic control requires dedicated analysis of physiological and pathological cellular heterogeneity within these tissues.However,investigations at the single cell level to decipher the complexities of cellular mechanisms remain challenging due to the fragile nature of certain cell types and technical noise within these metabolically active tissues,resulting in limited studies compared to well-characterized atlases in immune cell populations[2].
基金supported by the Jilin Provincial Science and Technology Department of China(20130413052GH)
文摘It is challenging and significant to explore the impacts of non-real-time services on real-time services from the perspective of jitter. Most of current researches on jitter made too many mathematical hypotheses on networks and traffic. This paper puts forward a tandem queuing model to characterize the real communication scenario where heterogeneous services are served by IEEE 802.15.4 wireless sensor networks（WSNs）, and then the packets served successfully are fed to Internet protocol（IP） networks. By analyzing the contention access processes in IEEE 802.15.4 WSNs, the authors derive the departure processes of the two types of services, i.e., the arrival processes of IP networks. The IP network is modeled as a queuing system, in which the real-time service is forwarded accompanied by the non-real-time service. Investigating the jitter of real-time services is intractable. Therefore, this paper abstracts this problem as a dynamic queuing system evolving on a dynamic time interval. Referring the transient analysis method（TAM）, this paper obtains the queue length in a random time interval which is scaled by the arrival of real-time services. Queue length evolution is closely connected with the jitter. Benefiting from the derivation in probability generation domain, the jitter of real-time services is obtained.
基金the National Natural Science Foundation of China(No.72303146)Project of Shanghai Science and Technology Innovation Action Plan 2022(No.22692105200)+1 种基金the National Social Science Major Fund of China(No.22ZDA062)the Fundamental Research Funds for the Central Universities(No.2020110308).
文摘Media inclinations,whether favorable or biased,play a pivotal role in shaping public opinion.Sometimes,media coverage may unintentionally foster skepticism towards foreign firms,which could create challenges for those companies when they enter new markets.Based on a panel dataset from 2005 to 2020,this is one of the first studies to investigate empirically the impact of media opinion on outward foreign direct investment(OFDI)behaviors at the firm level.The media inclination index was constructed according to the varying inclinations of media from different countries in their reporting on each event.We examined the impact of media inclination on the investment value,frequency,and number of industries.This study has revealed the following insights:(i)Positive media coverage can stimulate the investment behavior of Chinese firms.(ii)The heterogeneity analysis indicates that the promotional effect of media reporting inclination on OFDI is more significant for state-owned firms from the investor's perspective and especially pronounced for firms in developing countries from the investee's perspective.(iii)Diplomatic visits and scientific research cooperation can amplify the positive impact of media opinions on the OFDI behaviors of Chinese firms.
