Costs of air pollutants from shipping: a meta-regression analysis

ABSTRACT

This study estimated the external cost of air pollution from shipping by means of a meta-regression analysis, which has not been made before. Three pollutants, which were included in most of the primary studies, were considered: nitrogen oxides (NO_x), sulphur dioxides (SO₂) and particulate matters with a diameter of max 2.5 micrometres (PM_2.5). All primary studies included damages of health and a majority added impacts on agriculture and estimated the cost of air pollutants by transferring cost estimates from studies on costs of air emissions from transports in Europe. Different regression models and estimators were used and robust results were found of statistically significant emission elasticities of below one, i.e. total external costs increase by less than 1% when emissions increase by 1%. There was a small variation between the pollutants, with the highest elasticity for PM_2.5 and lowest for NO_x. Calculations of the marginal external cost of the pollutants showed the same pattern, with this cost being approximately six times higher for PM_2.5 than for the other pollutants. Common to all pollutants was that the marginal external cost decreases when emission increases. Another robust result was a significant increase in the cost of studies published in journals compared with other publication outlets. These findings point out some caution when transferring constant external unit cost of air pollutant from shipping, which is much applied in the literature, and the cost functions estimated in this study could thus provide a complementary transfer mechanism.     

Online channel strategies under different offline channel power structures for the Belt and Road of China

ABSTRACT

This paper explores the online channel strategies adopted by Chinese manufacturers with regard to the Belt and Road. It also investigates the effect of offline channel power structures and maritime transportation costs on online channel mode selection and pricing strategies. The offline channel power structures are classified into three types, namely, Chinese manufacturer Stackelberg (MS) structure, vertical Nash (VN) structure, and foreign retailer Stackelberg (RS) structure. Furthermore, a game model is developed among the Chinese manufacturer, foreign retailer, and cross-border e-tailer to investigate the interactions among offline channel power structures, maritime transportation costs, and Chinese manufacturers’ online channel mode selection. The results show that Chinese manufacturers’ preferences for the online agency selling mode increases correspondingly with the decrease in their market position and bargaining power. Moreover, foreign retailers can obtain higher profits in the online agency selling mode under the VN structure. However, the level of profit for foreign retailers depends on the intensity of their competition with cross-border e-tailers under the MS and RS structures. Finally, consumers in countries along the Belt and Road can obtain a higher surplus in the online agency selling mode under all of the structures.     

The effects of federal transit subsidy policy on investment decisions: The case of San Francisco's Geary Corridor

In the United States, federal funding for public transit often accounts for a large proportion of a local agency's budget, especially for capital investments. For this reason, local governments can be expected to plan a portfolio of projects that maximize federal contributions. This study examines the financial effects of federal transit subsidy policy on local transit investment decisions. Data from a System Planning Study for the Geary Corridor in San Francisco are used as an illustration. It is found that federal transit subsidy policy provides financial incentives for local decision-makers to select capital-intensive investment options that may not be efficient or effective. While federal financial incentives are not the only factor influencing local investment decisions, some reform of the current subsidy policy may be necessary to reduce the incentive for ineffective use of public resources.     

公路建设项目征地拆迁补偿费用确定与控制方法研究

文中以广东省公路建设项目征地拆迁费用的确定为例,以现行实施的征地拆迁补偿相关规定为基础,探讨征地数量和标准的计量、计算方法,建立征地拆迁标准动态数据库,以期对征地拆迁费用的确定和控制提供思路和实际操作指导。     

平交路口远引掉头设置方法分析

平交路口远引是解决路口流向禁限后车流转向问题的有效方法。通过对掉头地点的选址规划以及交叉口之间的协调控制进行研究,提出最佳掉头位置应满足的条件以及交叉口协调控制的相位差计算方法。通过对掉头通道通行能力的分析,提出实施掉头信号控制条件和具体实施方法。     

The relevance of international transport costs on food prices: Endogenous and exogenous effects

The paper addresses the problem of transport costs and their influence on food prices for South American imports. While transport does not seem to be in the focus of existing analyses, its impact on food prices might be underestimated and even closely linked to the development of commonly mentioned drivers of food prices. Since transport price formation is a function of demand and supply, drivers of food prices are also expected to impact on transport prices. The authors argue that a number of relevant factors that drive transport costs - and in consequence food prices - can be influenced by policy makers. Based on empirical analysis, the authors explain the functioning of the determinants of transport costs in the segment of international shipping, trying to describe their exogenous and endogenous components. These results are discussed in reference to policy development in the region.     

大数据时代我国快递业的发展现状与趋势

把握快递行业未来发展方向,梳理了大数据技术在快递行业的应用场景并分析了大数据技术对快递行业的影响。分析结果表明,大数据技术能帮助快递企业进行最优配送方案推荐、实时监控车辆设备、解构行业数据、分析市场格局等,从而帮助行业提升配送效率、降低配送成本。未来,快递行业将充分利用大数据技术加强对物流数据的收集、分析与业务应用。在大数据技术影响下,快递企业将呈现四大发展趋势：（1）时效进一步提升,成本继续降低;（2）从快递向物流上下游串联;（3）从国内向国际网络不断外扩;（4）先进的数据分析技术向其他行业外溢。     

How do economies of density in container handling operations affect ships’ time and emissions in port? Evidence from Norwegian container terminals

Efficient port services are prerequisites for competitive and sustainable maritime transports. This paper makes advances in studying the determinants of the time that ships spend in port and the associated emissions to air. We estimate a production model for cargo handling based on a unique dataset containing each port of call at the largest container terminals in Norway in 2014. In turn, we use auxiliary engine emission factors to estimate particulate matter and nitrogen oxide emissions from ships at berth, to determine how the corresponding damage costs of air pollution vary with container throughput, location, and terminal investments. We find that Norwegian container terminals operate under increasing returns to density. Small ships that unload few containers are far from reaping economies of density, leading to high marginal time requirements for container handling and consequently high marginal external costs. From a Pigouvian taxation perspective, port charges should therefore be regressive in the number of containers handled. Moreover, we find that the external costs of maritime transports are severely understated when port operations are ignored. Our model allows determining the marginal productivities of port facilities. Thereby, it is instrumental in designing port charges that are diversified according to the quantity of containers handled and the service quality (i.e., the speed of handling operations). Regarding contextual factors, we find that establishing high-frequent liner services improves the ship working rate, while simultaneous calls at a terminal impede productivity. The type of container (loading/unloading; empty/laden) also appears to influence the duration of ship working.     

Formulating cargo inventory costs for liner shipping network design

This study examines how to incorporate the inventory costs of containerized cargoes into existing liner service planning models such that the designed networks could be improved while not causing extra modeling/computational burden. Two approaches are compared: (i) not considering the inventory costs at all and (ii) incorporating the inventory costs associated with onboard time and those related to transshipment by assuming a fixed connection time. The two models are compared with the ideal model capturing the exact inventory costs on a route choice problem and a capacity planning problem based on extensive randomly generated and practical numerical experiments. The results show that: first, ignoring the inventory costs in service planning models may lead to network design with much higher costs (poor network design decisions); second, in service planning models assuming weekly frequency, the inventory costs associated with onboard time could be formulated exactly, and those related to the connection time of weekly services could be approximated by assuming fixed connection time of 3.5 days for ports with 1 day’s minimum connection time and 4.5 days for ports with 2 days’ minimum connection time.     

焊装车间机器人的节拍分析及优化设计

为了实现焊装车间降本增效的目标,对焊装车间自动生产线上机器人的生产节拍进行优化.通过分析机器人的工作时序逻辑,查找机器人不合理的工作时序,进而分析机器人的底层程序,修改程序上的问题,优化工作时序,消除机器人工作时序逻辑不合理产生的等待浪费,提升生产线的生产节拍,从而提高车间的生产效率,最终实现降本增效的目标.