To investigate the travel time prediction method of the freeway, a model based on the gradient boosting decision tree (GBDT) is proposed. Eleven variables (namely, travel time in current period T i , traffic flow in c...To investigate the travel time prediction method of the freeway, a model based on the gradient boosting decision tree (GBDT) is proposed. Eleven variables (namely, travel time in current period T i , traffic flow in current period Q i , speed in current period V i , density in current period K i , the number of vehicles in current period N i , occupancy in current period R i , traffic state parameter in current period X i , travel time in previous time period T i -1 , etc.) are selected to predict the travel time for 10 min ahead in the proposed model. Data obtained from VISSIM simulation is used to train and test the model. The results demonstrate that the prediction error of the GBDT model is smaller than those of the back propagation (BP) neural network model and the support vector machine (SVM) model. Travel time in current period T i is the most important variable among all variables in the GBDT model. The GBDT model can produce more accurate prediction results and mine the hidden nonlinear relationships deeply between variables and the predicted travel time.展开更多
This paper aims to characterize management accounting techniques at the Portuguese lodging industry, identifying the techniques adopted and the determinants of adopting them and their adequacy for the decision-making ...This paper aims to characterize management accounting techniques at the Portuguese lodging industry, identifying the techniques adopted and the determinants of adopting them and their adequacy for the decision-making process. It is also a purpose to understand the extent to which the industry adopts the Uniform System of Accounts for the Lodging Industry （USALI）. The sample includes 35 hotels, which were analyzed in the years 2009 and 2010. Evidence is found supporting the fact management accounting is a tool incorporated in the daily management practices of hotels and useful to support the decision-making process. The proportion used of traditional management accounting techniques is higher than the proportion of use of contemporary ones. The adoption of these techniques is influenced by the fact of the hotels being subsidiaries of a multinational hotel chain, as well as by their annual turnover. In Portugal, there is a weak use of USALI. It is more used in the large hotels and in hotels with a foreign control. Management accounting supports hotels to improve their performance, thus becoming relevant to analyze management accounting practices used by them, particularly which instruments and techniques. In this context, this study, the first of its kind in Portugal, is justified with the increasing need for accurate and actual information of the accounting practices of the hotels operating in Portugal.展开更多
The economic crisis within the European Union also involves a crisis of democracy. On the one side the austerity-politics of the Troika limits the influence of democratic procedures. On the other side new forms of soc...The economic crisis within the European Union also involves a crisis of democracy. On the one side the austerity-politics of the Troika limits the influence of democratic procedures. On the other side new forms of social protests rise in which social actors struggle for an extension of the democratic public： the resistance against evictions the self-organization of medical care, the occupation of public places etc. realized new forms of social cooperation, discussion and decision-making processes. On this background a reference to John Deweys theory of the democratic public seems to be helpful to reconstruct and to orient these conflicts and the claims raised in them. According to Dewey the normative criteria which we use if we evaluate actions or common institutions are a part of the social process and insofar a process themselves. These criteria have to be reflected and reformulated in new situations in which new social problems and conflicts occur. The democratic public is in this conception the realm in which a common elucidation of problematic social consequences of the existing institutions takes place and in which proposals for the overcoming of these consequences are formulated. Therefore it reconstructs the central norms embedded within the social institutions, it shows how collective actions guided by these norms leads to problematic social consequences. This is then the background for a critical reflection on, and a reformulation of the guiding norms of these institutions. To realize such a form of collective self-determination the democratic public can not be reduced to a separate political sphere, rather it has to be extended to all forms of social cooperation especially the economy.展开更多
基金The National Natural Science Foundation of China(No.51478114,51778136)
文摘To investigate the travel time prediction method of the freeway, a model based on the gradient boosting decision tree (GBDT) is proposed. Eleven variables (namely, travel time in current period T i , traffic flow in current period Q i , speed in current period V i , density in current period K i , the number of vehicles in current period N i , occupancy in current period R i , traffic state parameter in current period X i , travel time in previous time period T i -1 , etc.) are selected to predict the travel time for 10 min ahead in the proposed model. Data obtained from VISSIM simulation is used to train and test the model. The results demonstrate that the prediction error of the GBDT model is smaller than those of the back propagation (BP) neural network model and the support vector machine (SVM) model. Travel time in current period T i is the most important variable among all variables in the GBDT model. The GBDT model can produce more accurate prediction results and mine the hidden nonlinear relationships deeply between variables and the predicted travel time.
文摘This paper aims to characterize management accounting techniques at the Portuguese lodging industry, identifying the techniques adopted and the determinants of adopting them and their adequacy for the decision-making process. It is also a purpose to understand the extent to which the industry adopts the Uniform System of Accounts for the Lodging Industry （USALI）. The sample includes 35 hotels, which were analyzed in the years 2009 and 2010. Evidence is found supporting the fact management accounting is a tool incorporated in the daily management practices of hotels and useful to support the decision-making process. The proportion used of traditional management accounting techniques is higher than the proportion of use of contemporary ones. The adoption of these techniques is influenced by the fact of the hotels being subsidiaries of a multinational hotel chain, as well as by their annual turnover. In Portugal, there is a weak use of USALI. It is more used in the large hotels and in hotels with a foreign control. Management accounting supports hotels to improve their performance, thus becoming relevant to analyze management accounting practices used by them, particularly which instruments and techniques. In this context, this study, the first of its kind in Portugal, is justified with the increasing need for accurate and actual information of the accounting practices of the hotels operating in Portugal.
文摘The economic crisis within the European Union also involves a crisis of democracy. On the one side the austerity-politics of the Troika limits the influence of democratic procedures. On the other side new forms of social protests rise in which social actors struggle for an extension of the democratic public： the resistance against evictions the self-organization of medical care, the occupation of public places etc. realized new forms of social cooperation, discussion and decision-making processes. On this background a reference to John Deweys theory of the democratic public seems to be helpful to reconstruct and to orient these conflicts and the claims raised in them. According to Dewey the normative criteria which we use if we evaluate actions or common institutions are a part of the social process and insofar a process themselves. These criteria have to be reflected and reformulated in new situations in which new social problems and conflicts occur. The democratic public is in this conception the realm in which a common elucidation of problematic social consequences of the existing institutions takes place and in which proposals for the overcoming of these consequences are formulated. Therefore it reconstructs the central norms embedded within the social institutions, it shows how collective actions guided by these norms leads to problematic social consequences. This is then the background for a critical reflection on, and a reformulation of the guiding norms of these institutions. To realize such a form of collective self-determination the democratic public can not be reduced to a separate political sphere, rather it has to be extended to all forms of social cooperation especially the economy.
