This study aims to make an objective comparative analysis between the relative significance of three crucial modelling aspects involved in the probabilistic analysis of transport networks. The first question to addres...This study aims to make an objective comparative analysis between the relative significance of three crucial modelling aspects involved in the probabilistic analysis of transport networks. The first question to address is the extent to which the size of generated path sets can affect the prediction of the static flow in the path-based traffic assignment paradigm. The importance of this question arises from the fact that the need to generate a large quantity of paths may be perceived by analysts as a preventative reason as to the application of path-based stochastic traffic assignment （STA） models for large-scale networks. A simulated path generation algorithm, which allows the number of generated paths to be under modeller＇s control, is applied. Findings show that the size of the generated path sets does not substantially affect the flow prediction outcome in this case study. Further investigations with respect to the relative importance of STA model estimation （or equivalently, parameter calibration） and model specification （or equivalently, error term formulation） are also conducted. A paired combinatorial logit （PCL） assignment model with an origin-destination-specific-parameter, along with a heuristic method of model estimation （calibration）, is proposed. The proposed model cannot only accommodate the correlation between path utilities, but also accounts for the fact that travelling between different origin-destination （O-D） pairs can correspond to different levels of stochasticity and choice randomness. Results suggest that the estimation of the stochastic user equilibrium （SUE） models can affect the outcome of the flow prediction far more meaningfuUy than the complexitv of the choice model （i.e.. model specification）.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
Togolese agriculture is predominantly rain-fed and hence fundamentally dependent on the vagaries of weather. Thus, it is negatively affected by climate change. The present study assesses farmers’ perceptions and adap...Togolese agriculture is predominantly rain-fed and hence fundamentally dependent on the vagaries of weather. Thus, it is negatively affected by climate change. The present study assesses farmers’ perceptions and adaptation to climate change to enhance policy towards tackling the challenges climate change poses to the farmers in the study area. Descriptive statistics and multinomial logit (MNL) were used to analyze data obtained from a cross-sectional survey executed during the 2013/2014 agricultural production year in the maritime, plateau and savannah regions of Togo. The analysis of farmers’ perception to climate change reveals high increase in temperature and decrease in rainfall. These results are in line with the trend analysis of climate data that records from 1961 to 2013 about the study area especially on the temperature. Furthermore, the results show that crop diversification, change in crops, find off-farm jobs, change of the amount of land, change of the planting date and plant short season variety are the adaptation methods employed by the farmers. Moreover, with respect to the multinomial logit analysis, the results highlight that education level, farming experience, access extension services, access to credit and access to climate information are the factors that enhance farmers’ adaptive capacity to climate change and variability. Thus, there is room for better adaptation if government intensifies activities of extension workers and ensures that farmers have access to affordable credit schemes to increase their ability and flexibility to adopt adaptation measures. There is also a need to include climate change communication to facilitate exchange of climatic information that could enable smallholder farmers to adapt to changing planting dates. Finally, investment in education systems and creation of off-farm job opportunities in the rural areas can be underlined as a good policy option.展开更多
Climate change is a global phenomenon that involves the long-term fluctuation of the earth’s climate system. Specifically, climate change is acknowledged as a vital challenge to pastoralist production systems. Howeve...Climate change is a global phenomenon that involves the long-term fluctuation of the earth’s climate system. Specifically, climate change is acknowledged as a vital challenge to pastoralist production systems. However, limited research attention was given to exploring the determinants of climate change adaptation strategies in the southeastern part of Ethiopia. Thus, the study tried to assess the predictors of pastoralists’ climate change adaptation strategies in the Korahey zone of Ethiopia. The study was based on a survey of 215 representative pastoralist households were randomly selected from the three districts of the Korahey zone. To achieve the objective, household questionnaire surveys, key informant interviews, and focus group discussions were conducted to collect data at the household as well as the district level. Data were analyzed using descriptive statistics like percentage, frequency, mean, and inferential statistics (multinomial logit model). Multinomial logit was employed to analyze the determinant factors of pastoralists’ adaptation strategies to climate change. The finding shows that household pastoralists adopt different climate change adaptation strategies in their locality;from this herd diversification (10.7%), storage of fodder (14.4%), mobility (23.7%), Livestock off-take (12%), saving scheme (8.8%) and household and herd splitting (15.3%) are the major pastoralists’ adaptation strategies to climate change in the study area. The results of the multinomial logit model show that sex, age, family size, access to climate information, access to credit services, access to extension services and livestock ownership were identified as the major determinants factors of climate change adaptation strategies in Korahey zone. The study recommended that the local government, planners and decision-makers should give awareness regarding the role of information in the pastoralists’ adoption of climate change adaptation strategies and enhance extension services to support pastoralists in their ada展开更多
This paper evaluates different factors and parameters contributing to likelihood of bicycle crash injury severity levels. Multinomial Logit (MNL) model was used to analyze impact of different roadway features, traffic...This paper evaluates different factors and parameters contributing to likelihood of bicycle crash injury severity levels. Multinomial Logit (MNL) model was used to analyze impact of different roadway features, traffic characteristics and environmental conditions associated with bicycle crash injury severities. The multinomial model was used due to its flexibility in quantifying the effect of the independent variables for each injury severity categories. Model results showed that, severity of bicycle crashes increases with increase in vehicles per lane, number of lanes, bicyclist alcohol or drug use, routes with 35-45 mph posted speed limits, riding along curved or sloped road sections, when bicyclists approach or cross a signalized intersection, and at driveways. In addition, routes with a high percentage of trucks, roadway sections with curb and gutter, cloudy or foggy weather and obstructed vision were found to have high probability of severe injury. Segments with wider lanes, wide median and wide shoulders were found to have low likelihood of severe bicycle injury severities. Limited lighting locations was found to be associated with incapacitating injury and fatal crashes, indicating that insufficient visibility can potentially lead to severe crashes. Other findings are also presented in the paper.展开更多
文摘This study aims to make an objective comparative analysis between the relative significance of three crucial modelling aspects involved in the probabilistic analysis of transport networks. The first question to address is the extent to which the size of generated path sets can affect the prediction of the static flow in the path-based traffic assignment paradigm. The importance of this question arises from the fact that the need to generate a large quantity of paths may be perceived by analysts as a preventative reason as to the application of path-based stochastic traffic assignment （STA） models for large-scale networks. A simulated path generation algorithm, which allows the number of generated paths to be under modeller＇s control, is applied. Findings show that the size of the generated path sets does not substantially affect the flow prediction outcome in this case study. Further investigations with respect to the relative importance of STA model estimation （or equivalently, parameter calibration） and model specification （or equivalently, error term formulation） are also conducted. A paired combinatorial logit （PCL） assignment model with an origin-destination-specific-parameter, along with a heuristic method of model estimation （calibration）, is proposed. The proposed model cannot only accommodate the correlation between path utilities, but also accounts for the fact that travelling between different origin-destination （O-D） pairs can correspond to different levels of stochasticity and choice randomness. Results suggest that the estimation of the stochastic user equilibrium （SUE） models can affect the outcome of the flow prediction far more meaningfuUy than the complexitv of the choice model （i.e.. model specification）.
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.
文摘Togolese agriculture is predominantly rain-fed and hence fundamentally dependent on the vagaries of weather. Thus, it is negatively affected by climate change. The present study assesses farmers’ perceptions and adaptation to climate change to enhance policy towards tackling the challenges climate change poses to the farmers in the study area. Descriptive statistics and multinomial logit (MNL) were used to analyze data obtained from a cross-sectional survey executed during the 2013/2014 agricultural production year in the maritime, plateau and savannah regions of Togo. The analysis of farmers’ perception to climate change reveals high increase in temperature and decrease in rainfall. These results are in line with the trend analysis of climate data that records from 1961 to 2013 about the study area especially on the temperature. Furthermore, the results show that crop diversification, change in crops, find off-farm jobs, change of the amount of land, change of the planting date and plant short season variety are the adaptation methods employed by the farmers. Moreover, with respect to the multinomial logit analysis, the results highlight that education level, farming experience, access extension services, access to credit and access to climate information are the factors that enhance farmers’ adaptive capacity to climate change and variability. Thus, there is room for better adaptation if government intensifies activities of extension workers and ensures that farmers have access to affordable credit schemes to increase their ability and flexibility to adopt adaptation measures. There is also a need to include climate change communication to facilitate exchange of climatic information that could enable smallholder farmers to adapt to changing planting dates. Finally, investment in education systems and creation of off-farm job opportunities in the rural areas can be underlined as a good policy option.
文摘Climate change is a global phenomenon that involves the long-term fluctuation of the earth’s climate system. Specifically, climate change is acknowledged as a vital challenge to pastoralist production systems. However, limited research attention was given to exploring the determinants of climate change adaptation strategies in the southeastern part of Ethiopia. Thus, the study tried to assess the predictors of pastoralists’ climate change adaptation strategies in the Korahey zone of Ethiopia. The study was based on a survey of 215 representative pastoralist households were randomly selected from the three districts of the Korahey zone. To achieve the objective, household questionnaire surveys, key informant interviews, and focus group discussions were conducted to collect data at the household as well as the district level. Data were analyzed using descriptive statistics like percentage, frequency, mean, and inferential statistics (multinomial logit model). Multinomial logit was employed to analyze the determinant factors of pastoralists’ adaptation strategies to climate change. The finding shows that household pastoralists adopt different climate change adaptation strategies in their locality;from this herd diversification (10.7%), storage of fodder (14.4%), mobility (23.7%), Livestock off-take (12%), saving scheme (8.8%) and household and herd splitting (15.3%) are the major pastoralists’ adaptation strategies to climate change in the study area. The results of the multinomial logit model show that sex, age, family size, access to climate information, access to credit services, access to extension services and livestock ownership were identified as the major determinants factors of climate change adaptation strategies in Korahey zone. The study recommended that the local government, planners and decision-makers should give awareness regarding the role of information in the pastoralists’ adoption of climate change adaptation strategies and enhance extension services to support pastoralists in their ada
文摘This paper evaluates different factors and parameters contributing to likelihood of bicycle crash injury severity levels. Multinomial Logit (MNL) model was used to analyze impact of different roadway features, traffic characteristics and environmental conditions associated with bicycle crash injury severities. The multinomial model was used due to its flexibility in quantifying the effect of the independent variables for each injury severity categories. Model results showed that, severity of bicycle crashes increases with increase in vehicles per lane, number of lanes, bicyclist alcohol or drug use, routes with 35-45 mph posted speed limits, riding along curved or sloped road sections, when bicyclists approach or cross a signalized intersection, and at driveways. In addition, routes with a high percentage of trucks, roadway sections with curb and gutter, cloudy or foggy weather and obstructed vision were found to have high probability of severe injury. Segments with wider lanes, wide median and wide shoulders were found to have low likelihood of severe bicycle injury severities. Limited lighting locations was found to be associated with incapacitating injury and fatal crashes, indicating that insufficient visibility can potentially lead to severe crashes. Other findings are also presented in the paper.
