The motor vehicle industry in an emerging nation: the case of Brazil

As in other emerging nations, in Brazil, the motor vehicle industry is considered to be strategically important for economic development because of its backward and forward linkages and possibilities for export-led growth. This study analyses prospects for the industry by estimating an industry-level cost function that includes output of both vehicles and component parts with capital, labour and intermediate goods as inputs. The cost elasticity of output (an indicator of scale properties) and the elasticity relationships among inputs are explored. One unexpected outcome of the work that appears to be robust is that during early years of the study period, the industry had constant returns or even diseconomies of scale. However, during later years, when output was greater, there were economies of scale. This finding is likely the result of some combination of the entry of new firms, the development of new models or technological change. The study concludes that if firm output can be increased, economies of scale can be expected to strengthen the position of the Brazilian industry in the international marketplace.     

单车场无时间窗甩挂运输车辆调度的启发式算法

考虑了牵引车空驶、带空挂车行驶和带重挂车行驶所引起的成本差异，定义了牵引车运行成本的概念，将总运行成本最小作为调度方案优劣的判别指标，并同时考虑牵引车数量最少。将牵引任务分为四种类型，定义了任务链、虚拟任务、链内交叉和链间交叉的概念，提出了一种求解该类单车场甩挂运输车辆调度无时间窗约束的启发式算法，包括初始调运方案、链内优化、空车调运交叉、牵引车数量优化和链间交叉。最后给出了仿真算例，算法优化后的最终方案与初始方案相比，牵引车数量减少，总运行成本降低，验证了算法的有效性和可行性。     

基于两层架构协调的应急物资分配与车辆调度集成优化方法

针对突发事件下的应急物资调运问题，考虑了多个地区同时受灾以及多个出救点需要对其进行救灾并且各出救点的运力有限的情况，以最小化总的车辆运输费用，最大化救灾效率、各受灾点的救灾满意度，以及各受灾点得到救助的公平性为目标，建立了该问题的多目标混合整数非线性规划模型，并提出了一个基于两层架构协调的迭代式遗传算法进行求解。基于仿真数据的实验结果证明了所提出的模型和算法的有效性。     

防恶意干扰的VANET双群联合定位算法

传统的无线定位方法直接应用于车辆自组织网络(VANET)时，会被窃听方利用定位信息，从而导致严重的安全隐患。为此，提出基于Bancroft方法的双群组合定位算法,用于保障车辆自组织网络中车辆定位的安全性和准确性。算法利用两个群组的智能车辆节点分别进行定位，利用两组解分别反求伪距值，如果所获得的伪距值与经过节点钟差修正后的原始伪距值基本一致，则认为这一组解为最终的定位结果，从而保证了定位的正确性。同时，双群定位的信息分散性保证了系统整体的安全性。理论分析及算法仿真表明,双群联合定位算法可使窃听方的误码率稳定在较高水平。     

Dually sustainable urban mobility option: Shared-taxi operations with electric vehicles

Electric vehicles (EVs) are energy efficient and often presented as a zero-emission transport mode to achieve long-term decarbonization visions in the transport sector. The implementation of a sustainable transportation environment through EV utilization, however, requires the addressing of certain cost and environmental concerns such as limited driving range and battery-charging issues before its full potential can be realized. Nevertheless, a specific type of use of EVs, namely in taxi services, may elicit positive public opinion, as it promises a commitment toward sustainability in urban life. In light of this, this study proposes an integrated approach that combines EV operation with a conceptual design for shared-ride taxi services. As some productivity loss may be naturally expected due to the time spent in charging, it is important to look at whether such performance loss from the passenger and system standpoints can be offset with ingenuity in operational design. In this study, an EV taxi charge-replenishing scheme that can be coupled with a real-time taxi-dispatch algorithm is designed. The proposed EV charging schemes for taxi services are studied via simulations and the effects of the limited driving range and battery-charging details are examined from a system performance viewpoint. The simulation study also reveals illustrative results on the impact of the EV taxi fleet's operation on the charging system. Next, a real-time shared-taxi operation scheme that allows ride sharing with other passengers is proposed to maximize the operational efficiency. The simulation results suggest that the shared-taxi concept can be a viable option to improve on the limitations caused by EV operation. In addition, the importance of projected charging demands and queue delays at different charging locations are also addressed. Some limitations and a future research agenda are also discussed.     

The effect of cell phones on international motor vehicle fatality rates: A panel-data analysis

This paper analyzes the effects of cell phone usage and economic freedom on motor vehicle death rates by estimating regression models on data for three years across 38 countries. The models incorporate a representative set of motor vehicle fatality determinants. Results indicate that cell phone use has a statistically significant nonlinear impact on highway death rates and that economic freedom does not appear to have an effect.     

E-Shopping Patterns of Chinese and US Millennials

A conceptually based taxonomy of 22 distinct forms of e-shopping vehicles is proposed. A modification of the UTAUT and UTAUT2 models is introduced to explain how vehicles are interrelated in regard to consumer reliance upon them for their e-purchasing. A survey of over 1,000 millennial university students, 697 Chinese and 306 US, revealed strong support in both samples for the hypothesized six dimensional pattern underlying consumer vehicular reliance. Further, differences between Chinese and US samples lay not in the nature of the dimensions, but rather in the strength of reliance upon each dimension. Thus, the study demonstrates the utility of the concept/measure of shopper vehicular reliance, VPR (Vehicle Purchasing Reliance) for both practitioners and scientists. In cross-national comparisons, observed differences between samples in strength of reliance supported four of five hypotheses predicated on previously established national distinctions a) in trust and b) in the cultural value of individualism-collectivism.     

Progressive fragmentation of a traditional Mediterranean landscape by hazelnut plantations: The impact of CAP over time in the Langhe region (NW Italy)

Land use change is strongly modifying the traditional landscape of hilly productive Mediterranean sites. An example of these circumstances is the Langhe region (Piemonte, NW Italy), where woody plantations such as vineyards and orchards have been cultivated on hillslopes for centuries. In this paper we assess landscape changes occurred in the Diano study area (2651 ha) in the 1954–2000 period and we ascertain land use transition paths and rates of this rural ecosystem. Land use mapping obtained from object-oriented analysis of aerial photographs was used to quantify land use changes between 1954 and 2000. To examine the spatio-temporal patterns of land use change over time, a set of spatial statistics capturing different dimensions of landscape change was identified. An increase of landscape heterogeneity from 1954 to the present was observed due to the expansion of orchards and the fragmentation of field crops. A significant portion (55%) of current orchards surface is represented by former field crops, 24% by vineyards and 15% by forests. The strong expansion of hazelnut orchards concurred to the fragmentation of traditional rural landscape was dominated by vineyards, field crops and forests. Hazelnut orchards expansion was mainly located in places where grapes cultivation was less remunerative. A further expansion of hazelnut in the area should be planned, discussed and carefully monitored through change detection studies in order to avoid potential unsustainable use of the land.     

Modeling green vehicle adoption: An integrated approach for policy evaluation

This article employs an integrated discrete-continuous car ownership model to jointly forecast households’ future preferences on vehicle type, quantity and use, and to estimate greenhouse gas (GHG) emissions. The model system is estimated on a dataset collected from a web-based stated preference survey conducted in Maryland in 2014. The data contain vehicle purchase decisions and sociodemographic information of 456 households who were requested to state their future preferences over a 9-year period (2014–2022). In each time period, a respondent is faced to four alternatives that include the current vehicle, a new gasoline vehicle, a new hybrid electric vehicle, and a new battery electric vehicle. Intertemporal choices between conventional and “green” vehicles such as hybrid and electric cars capture dynamics in vehicle purchase decisions. Short run and medium-long run situations were predicted and compared based on the first 4-year data and the entire 9-year data of the dynamic panel. Vehicle GHG emissions were calculated correspondingly. We find the introduction of “green” vehicles makes a positive impact on car ownership and use, especially in a medium-long run. Two “green” taxation policies, gasoline tax and ownership tax, were proposed and their impact on vehicle use and emission reductions was evaluated. Results indicate that: (a) gasoline tax is a more effective way to reduce vehicle miles traveled and GHG emissions and (b) gasoline tax makes a higher impact on car use and emission reductions in the medium-long run, while ownership tax makes a higher impact in the short run.     

机场地面保障服务车辆协同调度和仿真优化

为实现大型机场地面保障服务高效化、智能化运行管理，通过研究多航班、多种地服车辆、多车场、带容量时间窗的复杂车辆路径规划问题，构建地服资源协同调度模型。结果表明：根据航班到达规律和机位分布情况，基于分解的高维进化算法求解效果较好，得到车辆使用数少、行驶距离短、超出时间窗惩罚函数最小和任务均衡的四维多目标优化问题的调度优化方案；通过Anylogic仿真软件验证，可实现机位占用情况、车辆使用情况动态分配和监控。