Fuel consumption for various driving styles in conventional and hybrid electric vehicles: Integrating driving cycle predictions with fuel consumption optimization*

Improving fuel economy and lowering emissions are key societal goals. Standard driving cycles, pre-designed by the US Environmental Protection Agency (EPA), have long been used to estimate vehicle fuel economy in laboratory-controlled conditions. They have also been used to test and tune different energy management strategies for hybrid electric vehicles (HEVs). This paper aims to estimate fuel consumption for a conventional vehicle and a HEV using personalized driving cycles extracted from real-world data to study the effects of different driving styles and vehicle types on fuel consumption when compared to the estimates based on standard driving cycles. To do this, we extracted driving cycles for conventional vehicles and HEVs from a large-scale U.S. survey that contains real-world GPS-based driving records. Next, the driving cycles were assigned to one of three categories: volatile, normal, or calm. Then, the driving cycles were used along with a driver-vehicle simulation that captures driver decisions (vehicle speed during a trip), powertrain, and vehicle dynamics to estimate fuel consumption for conventional vehicles and HEVs with power-split powertrain. To further optimize fuel consumption for HEVs, the Equivalent Consumption Minimization Strategy (ECMS) is applied. The results show that depending on the driving style and the driving scenario, conventional vehicle fuel consumption can vary widely compared with standard EPA driving cycles. Specifically, conventional vehicle fuel consumption was 13% lower in calm urban driving, but almost 34% higher for volatile highway driving compared with standard EPA driving cycles. Interestingly, when a driving cycle is predicted based on the application of case-based reasoning and used to tune the power distribution in a hybrid electric vehicle, its fuel consumption can be reduced by up to 12% in urban driving. Implications and limitations of the findings are discussed.     

雪中送炭还是过犹不及：政府补贴对企业研发的影响

基于2013—2018年沪深A股制造业民营企业上市公司的数据，实证探讨了政府补贴与企业研发的关系。研究发现政府补贴与研发强度之间并不是简单的线性关系，而是呈显著的倒U型关系。这意味着，适当的政府补贴能够激励企业进行研发投入，但过高的政府补贴反而对企业研发投入产生了挤出效应，是无效率的政府干预行为。研究结论有助于政府重新考虑对制造业民营企业的研发补贴支持力度，以期更有效地激发企业的创新积极性，加快建设创新型国家的步伐。     

Economic uncertainty,oil prices,hedging and U.S. stock returns of the airline industry

This paper examines the impacts of economic policy uncertainty and oil price shocks on stock returns of U.S. airlines using both industry and firm-level data. Our empirical approach considers a structural vector-autoregressive model with variables recognized to be important for airline returns including jet fuel price volatility. Empirical results confirm that oil price increase, economic uncertainty and jet fuel price volatility have significantly adverse effect on real stock returns of airlines both at industry and at firm level. In addition, we also find that hedging future fuel purchase has statistically positive impact on the smaller airlines. Our results suggest policy implications for practitioners, managers of airline industry and commodity investors.     

Turning green subsidies into sustainability: How green process innovation improves firms' green image

Green process innovation has been seen as a key strategy for manufacturing firms to pursue sustainable development. Yet, how to help manufacturing firms eliminate bottlenecks when implementing green process innovation remains poorly understood. To address this issue, the current study, which is anchored in the government incentive perspective, examines the drivers, contingent conditions, and consequences of green process innovation by using the panel data of manufacturing‐listed firms in China from 2013 to 2017. The results present valuable findings: (a) green subsidies are positively related to two dimensions of green process innovation, namely, cleaner production technology and end‐of‐pipe technology; (b) both cleaner production technology and end‐of‐pipe technology are positively related to firms' green image; (c) a firm's cleaner production technology mediates the relationship between green subsidies and its green image; and (d) higher absorptive capacity strengthens the indirect effect of green subsidies on a firm's green image via cleaner production technology. Our results provide meaningful theoretical and practical implications by revealing the benefits of green subsidies through green process innovation by leveraging levels of absorptive capacity.     

货运车辆燃油消耗与运输效率关系研究

文中采用理论分析与模型构建相结合的方式,研究货运车辆的燃油消耗与运输效率之间的关系,基于调研数据,采用回归分析的方法构建模型,得到了不同车型车辆的百吨公里燃油消耗量与实载率的倒数关系模型,为企业提高车辆运输效率,降低燃油消耗提供数据参考。     

Political Connections and Government Subsidies: Evidence from Financially Distressed Firms in China

Previous studies report mixed evidence regarding the effect of political connections on firm value. We seek new evidence in China, an important emerging market with a hallmark of a relationship-based economy. Using financially distressed firms (special treatment or ST firms) as a unique sample, we identify a direct channel through which political connections enhance firm value by showing that politically connected firms receive more government subsidies. Moreover, such effect becomes stronger for state-owned enterprises (SOEs), for firms with a better chance of survival, and after the government implemented a new policy to more strictly enforce the delisting in 2012.     

市场导向下的催化裂化技术发展

介绍根据市场的需求变化,在原馏分油催化裂化的基础上,陆续开发出的渣油催化裂化,多产气体烯烃的DCC、MIO、CPP技术,适合多产液化气和汽油的MGG、ARGG技术,生产高辛烷值汽油、多产柴油的催化裂化技术,以及同时多产液化气和柴油的MGD等技术,指出催化裂化已经发展成一个技术家族,较好地满足了市场的需求,随着市场需求的变化,催化裂化技术将有新的发展。     

生物质成型燃料产业发展前景分析

生物质成型燃料是一种高效的清洁能源,可以替代化石燃料,缓解人类面临的能源危机和环境困境。文章分析了产业发展的原料资源、成型技术、市场需求、成本-效益及政策支撑等优势。结果表明,在我国发展生物质成型燃料产业是可行的。同时,探讨产业发展面临的各种障碍,提出解决成型机生产技术瓶颈、用户环保意识与产品认知度薄弱、产业政策过于宏观等问题的策略建议。     

China’s Agricultural Policy Transition: Impacts of Recent Reforms and Future Scenarios

This article reviews recent developments in China’s agricultural domestic support policy, especially the transition from taxing farmers and agriculture to providing direct subsidies to grain production and purchased inputs. A model‐based quantitative analysis on the effects of these policy changes is presented. Simulation results suggest that recent policy changes have achieved the declared policy goals of increasing grain production and boosting farm income. Much of the increase in grain production and farm income can be attributed to higher per unit return to arable land, land reallocation to grain production and extra agricultural employment triggered by the policy changes. Based on the assumption that China’s public assistance to agriculture and farmers will continue and rise, two hypothetical future scenarios are simulated. Using all the support permitted under WTO de minimis limits with existing instruments, China’s policy will increase grain production, change trade patterns seemingly contrary to China’s comparative advantage, increase rural employment and significantly increase farm income (by more than 12%). If, however, decoupled instruments are applied to raise China’s agricultural domestic support to the same level, China’s agricultural production and trade will remain unchanged, rural employment remain stable, but farm income will be increased by nearly 15%.     

不同监督情境下政府创新支持对企业研发投入的影响——基于农业上市公司的实证研究

近年来,“三农”问题受到极大关注。为了应对外部资源、环境、科学技术等多重压力对农业升级与发展的影响,政府出台了诸多政策支持农业企业的技术研发与创新。本文从政府干预视角分析政府补助和税费返还两种形式的政府创新支持政策对农业企业研发投入的影响,重点分析机构投资者与大股东参与公司内部治理以及社会审计事务机构参与公司外部治理这两者所发挥的不同监督作用。研究发现：第一,不同形式的政府创新支持（政府补助和税费返还）对农业企业研发投入的影响并不一致。政府补助产生替代效应,税费返还则产生互补效应。第二,持股监督（机构投资者和大股东的持股比例上升）能增强政府补助对农业企业研发投入的替代效应,也能增强税费返还对农业企业研发投入的互补效应。第三,审计监督（社会审计事务机构的审计意见）会减弱政府补助支持对农业企业研发投入的替代效应,也会减弱税费返还对农业企业研发投入的互补效应。本文的研究发现为政府制定适宜的创新支持政策,以及合理发挥持股监督与审计监督的内外部治理作用,提供一定的决策依据和理论支持。