The study of air emission in maritime transportation is new, and the recognition of its importance has been rising in the recent decade. The emissions of CO2, SO2, NO2 and particulate matters from maritime transportat...The study of air emission in maritime transportation is new, and the recognition of its importance has been rising in the recent decade. The emissions of CO2, SO2, NO2 and particulate matters from maritime transportation have contributed to climate change and environmental degradation. Scientifically, analysts still have controversies regarding how to calculate the emissions and how to choose the baseline and methodologies. Three methods are generally used, namely the ＇bottom up＇ approach, the ＇top down＇ approach and the STEEM, which produce very different results, leading to various papers with great uncertainties. This, in turn, resuits in great difficulties to policy makers who attempt to regulate the emissions. A recent technique, the STEEM, is intended to combine the former two methods to reduce their drawbacks. However, the regulations based on its results may increase the costs of shipping companies and cause the competitiveness of the port states and coastal states. Quite a few papers have focused on this area and provided another fresh perspective for the air emission to be incorporated in maritime transportation regulations; these facts deserve more attention. This paper is to review the literature on the debates over air emission calculation, with particular attention given to the STEEM and the refined estimation methods. It also reviews related literature on the economic analysis of maritime transportation emission regulations, and provides an insight into such analysis. At the end of this paper, based on a review and analysis of previous literature, we conclude with the policy indications in the future and work that should be done. As the related regulations in maritime transportation emissions are still at their beginning stage in China, this paper provides specific suggestions on how China should regulate emissions in the maritime transportation sector.展开更多
HP defines an SQL-like language to specify organizational policies (or constraints) in workflow systems. Three types of policies were studied including qualification, requirements and substitution policies which can n...HP defines an SQL-like language to specify organizational policies (or constraints) in workflow systems. Three types of policies were studied including qualification, requirements and substitution policies which can not handle complex role resolution such as Separation of Roles and Binding of Roles, and several exception situations, such as Role Delegation and Role Unavailable. From the perspective of project-oriented workflow, a project and its sub-projects can be under the charge of teams (or virtual teams). The teams should satisfy the role resolution of the projects managed by the team. To support the above requirements, based on team-enabled organization model, this paper extended HP’s policy language to support the role resolution in project-oriented workflow, and provided its modeling and enforcement mechanism.展开更多
基金supported by the Program for New Century Excellent Talents in University (NCET), NCET-07-0777
文摘The study of air emission in maritime transportation is new, and the recognition of its importance has been rising in the recent decade. The emissions of CO2, SO2, NO2 and particulate matters from maritime transportation have contributed to climate change and environmental degradation. Scientifically, analysts still have controversies regarding how to calculate the emissions and how to choose the baseline and methodologies. Three methods are generally used, namely the ＇bottom up＇ approach, the ＇top down＇ approach and the STEEM, which produce very different results, leading to various papers with great uncertainties. This, in turn, resuits in great difficulties to policy makers who attempt to regulate the emissions. A recent technique, the STEEM, is intended to combine the former two methods to reduce their drawbacks. However, the regulations based on its results may increase the costs of shipping companies and cause the competitiveness of the port states and coastal states. Quite a few papers have focused on this area and provided another fresh perspective for the air emission to be incorporated in maritime transportation regulations; these facts deserve more attention. This paper is to review the literature on the debates over air emission calculation, with particular attention given to the STEEM and the refined estimation methods. It also reviews related literature on the economic analysis of maritime transportation emission regulations, and provides an insight into such analysis. At the end of this paper, based on a review and analysis of previous literature, we conclude with the policy indications in the future and work that should be done. As the related regulations in maritime transportation emissions are still at their beginning stage in China, this paper provides specific suggestions on how China should regulate emissions in the maritime transportation sector.
文摘HP defines an SQL-like language to specify organizational policies (or constraints) in workflow systems. Three types of policies were studied including qualification, requirements and substitution policies which can not handle complex role resolution such as Separation of Roles and Binding of Roles, and several exception situations, such as Role Delegation and Role Unavailable. From the perspective of project-oriented workflow, a project and its sub-projects can be under the charge of teams (or virtual teams). The teams should satisfy the role resolution of the projects managed by the team. To support the above requirements, based on team-enabled organization model, this paper extended HP’s policy language to support the role resolution in project-oriented workflow, and provided its modeling and enforcement mechanism.
