A geometric framework is proposed for multinomial nonlinear modelsbased on a modified version of the geometric structure presented by Bates & Watts[4]. We use this geometric framework to study some asymptotic infe...A geometric framework is proposed for multinomial nonlinear modelsbased on a modified version of the geometric structure presented by Bates & Watts[4]. We use this geometric framework to study some asymptotic inference in terms ofcurvatures for multinomial nonlinear models. Our previous results [15] for ordinarynonlinear regression models are extended to multinomial nonlinear models.展开更多
In order to deal with the problems in P2P systems of file sharing such as unreliability of the service,security risk and attacks caused by malicious peers,a novel Trust Model based on Multinomial subjective logic and ...In order to deal with the problems in P2P systems of file sharing such as unreliability of the service,security risk and attacks caused by malicious peers,a novel Trust Model based on Multinomial subjective logic and Risk mechanism(MR-TM) is proposed.According to the multinomial subjective logic theory,the model introduces the risk mechanism.It assesses and quantifies the peers' risk,through computing the resource value,vulnerability,threat level,and finally gets the trust value by the risk value and the reputation value.The introduction of the risk value can reflect the recent behaviors of the peers better and make the system more sensitive to malicious acts.Finally,the effectiveness and feasibility of the model is illustrated by the simulation experiment designed with Peersim.展开更多
Objective:To report the indigenous people's uses of plants from a multidimensional perspective in a remote area where strong ethnobotanical cultural practices prevail. Methods:An ethnobotanical survey was conducte...Objective:To report the indigenous people's uses of plants from a multidimensional perspective in a remote area where strong ethnobotanical cultural practices prevail. Methods:An ethnobotanical survey was conducted in the field during 2014-2016. Ethnobotanical data were gathered from 182 informants through oral interviews and semi-structured questionnaires. The distribution of plants was explored using both descriptive and graphical methods. Further,a Multinomial Logit Specification was applied to find out the probability of the occurrence of diverse utilization of plants in multipurpose domains. Results:The study identified 202 plant species distributed among 71 families and 156 genera. Ethnobotanical data indicate that there are more medicinal(36.96%) uses of plants as compared to all other use categories. The output from the Multinomial Logit Specifications(MLS) model reveals that perennial and non-woody plants are exploited more for medicinal and food uses than annual and woody plants. In the context of ethnomedicinal uses,aerial plant parts particularly leaves are more extensively used for the preparation of herbal recipes as compared to underground parts. Conclusions:The results of the study emphasize the need to create awareness among the local communities about the conservation status of plant species in order to maintain a sustainable resource of plant-derived materials into the future. The novel econometric approach employed in this study adds a new insightful methodology to the existing body of literature in the field of ethnobotany. We strongly recommend conservation measures,alongside phytochemical and pharmacological studies on the useful plant species identified in this study in order to ensure their sustainable and effective utilization.展开更多
We consider testing hypotheses concerning comparing dispersions between two parameter vectors of multinomial distributions in both one-sample and two-sample cases. The comparison criterion is the concept of Schur majo...We consider testing hypotheses concerning comparing dispersions between two parameter vectors of multinomial distributions in both one-sample and two-sample cases. The comparison criterion is the concept of Schur majorization. A new dispersion index is proposed for testing the hypotheses. The corresponding test for the one-sample problem is an exact test. For the two-sample problem, the bootstrap is used to approximate the null distribution of the test statistic and the p-value. We prove that the bootstrap test is asymptotically correct and consistent. Simulation studies for the bootstrap test are reported and a real life example is presented.展开更多
In wireless sensor networks(WSNs),nodes are usually powered by batteries.Since the energy consumption directly impacts the network lifespan,energy saving is a vital issue in WSNs,especially in the designing phase of c...In wireless sensor networks(WSNs),nodes are usually powered by batteries.Since the energy consumption directly impacts the network lifespan,energy saving is a vital issue in WSNs,especially in the designing phase of cryptographic algorithms.As a complementary mechanism,reputation has been applied to WSNs.Different from most reputation schemes that were based on beta distribution,negative multinomial distribution was deduced and its feasibility in the reputation modeling was proved.Through comparison tests with beta distribution based reputation in terms of the update computation,results show that the proposed method in this research is more energy-efficient for the reputation update and thus can better prolong the lifespan of WSNs.展开更多
In order to deal with the problems in P2P systems such as unreliability of the Service, security risk and attacks caused by malicious peers, a novel trust model MSL-TM based on the Multinomial Subjective Logic is prop...In order to deal with the problems in P2P systems such as unreliability of the Service, security risk and attacks caused by malicious peers, a novel trust model MSL-TM based on the Multinomial Subjective Logic is proposed. The model uses multinomial ratings and Dirichlet distribution to compute the expectation of the subjective opinion and accordingly draws the peer’s reputation value and risk value, and finally gets the trust value. The decay of time, rating credibility and the risk value are introduced to reflect the recent behaviors of the peers and make the system more sensitive to malicious acts. Finally, the effectiveness and feasibility of the model is illustrated by the simulation experiment designed with peersim.展开更多
Multinomial logistic regression (MNL) is an attractive statistical approach in modeling the vehicle crash severity as it does not require the assumption of normality, linearity, or homoscedasticity compared to other a...Multinomial logistic regression (MNL) is an attractive statistical approach in modeling the vehicle crash severity as it does not require the assumption of normality, linearity, or homoscedasticity compared to other approaches, such as the discriminant analysis which requires these assumptions to be met. Moreover, it produces sound estimates by changing the probability range between 0.0 and 1.0 to log odds ranging from negative infinity to positive infinity, as it applies transformation of the dependent variable to a continuous variable. The estimates are asymptotically consistent with the requirements of the nonlinear regression process. The results of MNL can be interpreted by both the regression coefficient estimates and/or the odd ratios (the exponentiated coefficients) as well. In addition, the MNL can be used to improve the fitted model by comparing the full model that includes all predictors to a chosen restricted model by excluding the non-significant predictors. As such, this paper presents a detailed step by step overview of incorporating the MNL in crash severity modeling, using vehicle crash data of the Interstate I70 in the State of Missouri, USA for the years (2013-2015).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
This research delves into the hurdles and strategies aimed at augmenting the market involvement of smallholder carrot farmers in Nakuru County, Kenya. Employing a Multinomial Logit (MNL) model, it scrutinizes the fact...This research delves into the hurdles and strategies aimed at augmenting the market involvement of smallholder carrot farmers in Nakuru County, Kenya. Employing a Multinomial Logit (MNL) model, it scrutinizes the factors influencing the selection of marketing outlets among carrot farmers. The findings unveil that a significant majority (81%) of surveyed farmers actively participate in diverse market outlets, encompassing the farm gate, cleaning point, local market, external market, and export market. Notably, pivotal buyers include aggregators, brokers, wholesalers, retailers, and consumers, with transactions predominantly occurring at the farm level. Additionally, the analysis discerns substantial influences of socio-economic characteristics, experiential factors, and geographical proximity on farmers’ choices of market outlets. Specifically, gender, age, land size, farming experience, and distance to markets emerge as critical determinants. Moreover, the study delves into the examination of market margins along the carrot value chain, shedding light on the potential profitability of carrot farming in the region. Remarkably, higher average gross margins are identified in export and external markets, signaling lucrative prospects for farmers targeting these segments. However, disparities in profit distribution between farmers and traders underscore the necessity for interventions to ensure equitable value distribution throughout the value chain. These findings underscore the imperative for tailored interventions to tackle challenges and foster inclusive agricultural development. Strategies such as farmer organizations, contracting, and vertical integration are advocated to enhance market access and profitability for smallholder carrot farmers. Thus, this study enriches our comprehension of the dynamics within carrot value chains and provides valuable insights for policymakers and development practitioners aiming to uplift rural livelihoods and bolster food security.展开更多
Spatially explicit simulation of land use change is the basis for estimating the effects of land use and cover change on energy fluxes, ecology and the environment. At the pixel level, logistic regression is one of th...Spatially explicit simulation of land use change is the basis for estimating the effects of land use and cover change on energy fluxes, ecology and the environment. At the pixel level, logistic regression is one of the most common approaches used in spatially explicit land use allocation models to determine the relationship between land use and its causal factors in driving land use change, and thereby to evaluate land use suitability. However, these models have a drawback in that they do not determine/ allocate land use based on the direct relationship between land use change and its driving factors. Consequently, a multinomial logistic regression method was introduced to address this flaw, and thereby, judge the suitability of a type of land use in any given pixel in a case study area of the Jiangxi Province, China. A comparison of the two regression methods indicated that the proportion of correctly allocated pixels using multinomial logistic regression was 92.98%, which was 8.47% higher than that obtained using logistic regression. Paired t-test results also showed that pixels were more clearly distinguished by multinomial logistic regression than by logistic regression. In conclusion, multinomial logistic regression is a more efficient and accurate method for the spatial allocation of land use changes. The application of this method in future land use change studies may improve the accuracy of predicting the effects of land use and cover change on energy fluxes, ecology, and environment.展开更多
This paper investigates one-sided hypotheses testing for p[1], the largest cell probability of multinomial distribution. A small sample test of Ethier (1982) is extended to the general cases. Based on an estimator of ...This paper investigates one-sided hypotheses testing for p[1], the largest cell probability of multinomial distribution. A small sample test of Ethier (1982) is extended to the general cases. Based on an estimator of p[1], a kind of large sample tests is proposed. The asymptotic power of the above tests under local alternatives is derived. An example is presented at the end of this paper.展开更多
选取Lending Club 2007年1月至2016年3月的交易数据,运用Multinomial Lasso-logistic模型得到影响平台违约的关键因素并预测了违约概率.结果表明,出借人实际借款的总额、借款利率等因素对违约有显著的影响,此外与以往研究不同的是,发现...选取Lending Club 2007年1月至2016年3月的交易数据,运用Multinomial Lasso-logistic模型得到影响平台违约的关键因素并预测了违约概率.结果表明,出借人实际借款的总额、借款利率等因素对违约有显著的影响,此外与以往研究不同的是,发现由借款人提供的借款描述和借款标题等文本信息与违约之间显著负相关,说明当借款人提供更多的文本信息,将表现出相对较低的违约率.研究结论补充了现有文献的不足,对P2P平台的监管和投资者的决策提供了借鉴意义.展开更多
This paper discusses inference for ordered parameters of multinomial distributions. We first show that the asymptotic distributions of their maximum likelihood estimators (MLEs) are not always normal and the bootstrap...This paper discusses inference for ordered parameters of multinomial distributions. We first show that the asymptotic distributions of their maximum likelihood estimators (MLEs) are not always normal and the bootstrap distribution estimators of the MLEs can be inconsistent. Then a class of weighted sum estimators (WSEs) of the ordered parameters is proposed. Properties of the WSEs are studied, including their asymptotic normality. Based on those results, large sample inferences for smooth functions of the ordered parameters can be made. Especially, the confidence intervals of the maximum cell probabilities are constructed. Simulation results indicate that this interval estimation performs much better than the bootstrap approaches in the literature. Finally, the above results for ordered parameters of multinomial distributions are extended to more general distribution models.展开更多
Let F_(p.t)(n) denote the number of the coefficients of (x_1+x_2+…+x_t)~j. 0≤j≤n-1, which are not divisible by the prime p. Define G_(p.t)(n)=F_(p.t)(n)/n~θ and β(p.t)=lim inf F_(p.t)(n)/n~θ, where θ=(log(p+t-1...Let F_(p.t)(n) denote the number of the coefficients of (x_1+x_2+…+x_t)~j. 0≤j≤n-1, which are not divisible by the prime p. Define G_(p.t)(n)=F_(p.t)(n)/n~θ and β(p.t)=lim inf F_(p.t)(n)/n~θ, where θ=(log(p+t-1 t))/(logp). In this paper, we mainly prove that G_(p.t) can be extended to a continuous function on R^+, and the function G_(p.t) is nowhere monotonic. Both the set of differential points of the function G_(p.t) and the set of non-differential points of the function G_(p.t) are dense in R^+.展开更多
文摘A geometric framework is proposed for multinomial nonlinear modelsbased on a modified version of the geometric structure presented by Bates & Watts[4]. We use this geometric framework to study some asymptotic inference in terms ofcurvatures for multinomial nonlinear models. Our previous results [15] for ordinarynonlinear regression models are extended to multinomial nonlinear models.
基金Supported by the National Natural Science Foundation of China(No.60873203)the Foundation of Key Laboratory of Aerospace Information Security and Trusted Computting,Ministry of Education(No.AISTC2009_03)+1 种基金Hebei Natural Funds for Distinguished Young Scientists(No. F2010000317)the Natural Science Foundation of Hebei Province(No.F2008000646)
文摘In order to deal with the problems in P2P systems of file sharing such as unreliability of the service,security risk and attacks caused by malicious peers,a novel Trust Model based on Multinomial subjective logic and Risk mechanism(MR-TM) is proposed.According to the multinomial subjective logic theory,the model introduces the risk mechanism.It assesses and quantifies the peers' risk,through computing the resource value,vulnerability,threat level,and finally gets the trust value by the risk value and the reputation value.The introduction of the risk value can reflect the recent behaviors of the peers better and make the system more sensitive to malicious acts.Finally,the effectiveness and feasibility of the model is illustrated by the simulation experiment designed with Peersim.
文摘Objective:To report the indigenous people's uses of plants from a multidimensional perspective in a remote area where strong ethnobotanical cultural practices prevail. Methods:An ethnobotanical survey was conducted in the field during 2014-2016. Ethnobotanical data were gathered from 182 informants through oral interviews and semi-structured questionnaires. The distribution of plants was explored using both descriptive and graphical methods. Further,a Multinomial Logit Specification was applied to find out the probability of the occurrence of diverse utilization of plants in multipurpose domains. Results:The study identified 202 plant species distributed among 71 families and 156 genera. Ethnobotanical data indicate that there are more medicinal(36.96%) uses of plants as compared to all other use categories. The output from the Multinomial Logit Specifications(MLS) model reveals that perennial and non-woody plants are exploited more for medicinal and food uses than annual and woody plants. In the context of ethnomedicinal uses,aerial plant parts particularly leaves are more extensively used for the preparation of herbal recipes as compared to underground parts. Conclusions:The results of the study emphasize the need to create awareness among the local communities about the conservation status of plant species in order to maintain a sustainable resource of plant-derived materials into the future. The novel econometric approach employed in this study adds a new insightful methodology to the existing body of literature in the field of ethnobotany. We strongly recommend conservation measures,alongside phytochemical and pharmacological studies on the useful plant species identified in this study in order to ensure their sustainable and effective utilization.
基金Sponsored by the National NSFC (10771126, 10801130)
文摘We consider testing hypotheses concerning comparing dispersions between two parameter vectors of multinomial distributions in both one-sample and two-sample cases. The comparison criterion is the concept of Schur majorization. A new dispersion index is proposed for testing the hypotheses. The corresponding test for the one-sample problem is an exact test. For the two-sample problem, the bootstrap is used to approximate the null distribution of the test statistic and the p-value. We prove that the bootstrap test is asymptotically correct and consistent. Simulation studies for the bootstrap test are reported and a real life example is presented.
基金National Natural Science Foundations of China (No.61073177,60905037)
文摘In wireless sensor networks(WSNs),nodes are usually powered by batteries.Since the energy consumption directly impacts the network lifespan,energy saving is a vital issue in WSNs,especially in the designing phase of cryptographic algorithms.As a complementary mechanism,reputation has been applied to WSNs.Different from most reputation schemes that were based on beta distribution,negative multinomial distribution was deduced and its feasibility in the reputation modeling was proved.Through comparison tests with beta distribution based reputation in terms of the update computation,results show that the proposed method in this research is more energy-efficient for the reputation update and thus can better prolong the lifespan of WSNs.
文摘In order to deal with the problems in P2P systems such as unreliability of the Service, security risk and attacks caused by malicious peers, a novel trust model MSL-TM based on the Multinomial Subjective Logic is proposed. The model uses multinomial ratings and Dirichlet distribution to compute the expectation of the subjective opinion and accordingly draws the peer’s reputation value and risk value, and finally gets the trust value. The decay of time, rating credibility and the risk value are introduced to reflect the recent behaviors of the peers and make the system more sensitive to malicious acts. Finally, the effectiveness and feasibility of the model is illustrated by the simulation experiment designed with peersim.
文摘Multinomial logistic regression (MNL) is an attractive statistical approach in modeling the vehicle crash severity as it does not require the assumption of normality, linearity, or homoscedasticity compared to other approaches, such as the discriminant analysis which requires these assumptions to be met. Moreover, it produces sound estimates by changing the probability range between 0.0 and 1.0 to log odds ranging from negative infinity to positive infinity, as it applies transformation of the dependent variable to a continuous variable. The estimates are asymptotically consistent with the requirements of the nonlinear regression process. The results of MNL can be interpreted by both the regression coefficient estimates and/or the odd ratios (the exponentiated coefficients) as well. In addition, the MNL can be used to improve the fitted model by comparing the full model that includes all predictors to a chosen restricted model by excluding the non-significant predictors. As such, this paper presents a detailed step by step overview of incorporating the MNL in crash severity modeling, using vehicle crash data of the Interstate I70 in the State of Missouri, USA for the years (2013-2015).
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This research delves into the hurdles and strategies aimed at augmenting the market involvement of smallholder carrot farmers in Nakuru County, Kenya. Employing a Multinomial Logit (MNL) model, it scrutinizes the factors influencing the selection of marketing outlets among carrot farmers. The findings unveil that a significant majority (81%) of surveyed farmers actively participate in diverse market outlets, encompassing the farm gate, cleaning point, local market, external market, and export market. Notably, pivotal buyers include aggregators, brokers, wholesalers, retailers, and consumers, with transactions predominantly occurring at the farm level. Additionally, the analysis discerns substantial influences of socio-economic characteristics, experiential factors, and geographical proximity on farmers’ choices of market outlets. Specifically, gender, age, land size, farming experience, and distance to markets emerge as critical determinants. Moreover, the study delves into the examination of market margins along the carrot value chain, shedding light on the potential profitability of carrot farming in the region. Remarkably, higher average gross margins are identified in export and external markets, signaling lucrative prospects for farmers targeting these segments. However, disparities in profit distribution between farmers and traders underscore the necessity for interventions to ensure equitable value distribution throughout the value chain. These findings underscore the imperative for tailored interventions to tackle challenges and foster inclusive agricultural development. Strategies such as farmer organizations, contracting, and vertical integration are advocated to enhance market access and profitability for smallholder carrot farmers. Thus, this study enriches our comprehension of the dynamics within carrot value chains and provides valuable insights for policymakers and development practitioners aiming to uplift rural livelihoods and bolster food security.
基金Acknowledgements This research was financially supported by the National Basic Research of China (2010CB950900) and the National Natural Science Foundation of China (Grant Nos. 71225005 and 41071343). Two anonymous reviewers are sincerely acknowledged for their valuable comments which have significantly improved the manuscript.
文摘Spatially explicit simulation of land use change is the basis for estimating the effects of land use and cover change on energy fluxes, ecology and the environment. At the pixel level, logistic regression is one of the most common approaches used in spatially explicit land use allocation models to determine the relationship between land use and its causal factors in driving land use change, and thereby to evaluate land use suitability. However, these models have a drawback in that they do not determine/ allocate land use based on the direct relationship between land use change and its driving factors. Consequently, a multinomial logistic regression method was introduced to address this flaw, and thereby, judge the suitability of a type of land use in any given pixel in a case study area of the Jiangxi Province, China. A comparison of the two regression methods indicated that the proportion of correctly allocated pixels using multinomial logistic regression was 92.98%, which was 8.47% higher than that obtained using logistic regression. Paired t-test results also showed that pixels were more clearly distinguished by multinomial logistic regression than by logistic regression. In conclusion, multinomial logistic regression is a more efficient and accurate method for the spatial allocation of land use changes. The application of this method in future land use change studies may improve the accuracy of predicting the effects of land use and cover change on energy fluxes, ecology, and environment.
基金This work was supported partly by the National Natural Science Foundation of China(Grant No.10371126).
文摘This paper investigates one-sided hypotheses testing for p[1], the largest cell probability of multinomial distribution. A small sample test of Ethier (1982) is extended to the general cases. Based on an estimator of p[1], a kind of large sample tests is proposed. The asymptotic power of the above tests under local alternatives is derived. An example is presented at the end of this paper.
文摘选取Lending Club 2007年1月至2016年3月的交易数据,运用Multinomial Lasso-logistic模型得到影响平台违约的关键因素并预测了违约概率.结果表明,出借人实际借款的总额、借款利率等因素对违约有显著的影响,此外与以往研究不同的是,发现由借款人提供的借款描述和借款标题等文本信息与违约之间显著负相关,说明当借款人提供更多的文本信息,将表现出相对较低的违约率.研究结论补充了现有文献的不足,对P2P平台的监管和投资者的决策提供了借鉴意义.
基金supported by National Natural Science Foundation of China (Grant No. 10371126)
文摘This paper discusses inference for ordered parameters of multinomial distributions. We first show that the asymptotic distributions of their maximum likelihood estimators (MLEs) are not always normal and the bootstrap distribution estimators of the MLEs can be inconsistent. Then a class of weighted sum estimators (WSEs) of the ordered parameters is proposed. Properties of the WSEs are studied, including their asymptotic normality. Based on those results, large sample inferences for smooth functions of the ordered parameters can be made. Especially, the confidence intervals of the maximum cell probabilities are constructed. Simulation results indicate that this interval estimation performs much better than the bootstrap approaches in the literature. Finally, the above results for ordered parameters of multinomial distributions are extended to more general distribution models.
基金Supported by the National Natural Science Foundation of China. Grant No. 10171046 and the "333 Project" Foundation of Jiangsu Province of China.
文摘Let F_(p.t)(n) denote the number of the coefficients of (x_1+x_2+…+x_t)~j. 0≤j≤n-1, which are not divisible by the prime p. Define G_(p.t)(n)=F_(p.t)(n)/n~θ and β(p.t)=lim inf F_(p.t)(n)/n~θ, where θ=(log(p+t-1 t))/(logp). In this paper, we mainly prove that G_(p.t) can be extended to a continuous function on R^+, and the function G_(p.t) is nowhere monotonic. Both the set of differential points of the function G_(p.t) and the set of non-differential points of the function G_(p.t) are dense in R^+.