Bayesian selection of technology assumptions for the transformation from supply-use to input–output tables

ABSTRACT

In the construction of input–output models from supply-use tables, technology assumptions disambiguate how an industry uses inputs in the production recipe of multiple outputs. This paper uses Bayes' theorem to select technology assumptions, taking into account empirical observations. The paper presents a formulation to explore hybrids between product and industry technology assumptions in product-by-product tables. We then present Markov chain Monte-Carlo techniques to implement the Bayesian method for selecting technology assumptions. We apply the method in a case study using Eurostat supply-use tables of 2004 and 2005, exhibiting a volume of secondary products of less than 13%, and 59 products and industries per country. The results show that the choice of technology is not important, given that there is no strong evidence in favour of any of them.     

多波束移动卫星系统的自适应开环预编码方法

对于卫星移动通信系统，由于卫星与地面终端之间的相对运动以及星地间传输延迟，传统的基于理想信道信息的预编码方法是不适用的。针对这一问题，提出了一种基于开环信道估计的预编码方法。卫星端利用开环获取的部分信道信息实现多波束联合预编码，并导出了系统传输速率的闭合解析表达式。此外，为了克服强干扰环境下多波束预编码系统性能恶化问题，提出了一种自适应预编码传输方法。卫星发射机依据开环获得的慢时变用户位置信道信息和信道统计量信息，自适应地选择预编码方法或传统频率复用方法，实现最优的系统性能。理论分析和仿真结果表明，与传统的干扰抑制方法相比，所提方法能实现更优的系统性能，同时也克服了传统预编码方法的局限性。     

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.     

混合型基金绩效评估及驱动因素分析——基于DEA-Tobit模型

将随机选出的混合型基金作为研究样本,采用DEA-Tobit二阶段模型进行研究.首先利用数据包络模型对样本进行绩效评估,在此基础上,利用Tobit模型研究相关指标对于基金绩效的影响机制.结果表明,基金本身所面临的风险收益因素以及基金经理团队稳定性对于基金绩效均具显著影响.最后结合实证结果就提升中国基金绩效提出相关的建议.     

The internationalization paradox: Untangling dependence in multinational state hybrids

We investigate the internationalization of firms with ownership links to the state from the perspective of resource dependence theory, and argue that internationalization can reduce dependence on the home country government, but, paradoxically, this strategy also creates additional dependences, shifts the power balance, and provides rationales for increasing government control. Utilizing a ‘critical’ case – Vale from Brazil – we analyze different conditions that enable greater autonomy for and greater government control over multinational state hybrids in the context of internationalization. We contribute to the international business literature by generating a novel framework that considers the effects of market trends (extractive industry) and non-market trends (home country policies) on the internationalization of state hybrids.     

基于两阶段法的多车型卷烟配送路径优化研究

在烟草商业企业中,物流是其重要的环节,是连接客户与烟草企业间的纽带,其卷烟配送线路设计的合理与否直接影响到卷烟的配送效率和配送成本,就如何合理的规划线路成为卷烟配送的关键问题。文章以Q烟草公司为例,运用先分组后路线的两阶段法对问题进行求解,先利用K-means聚类算法对区域进行划分,再考虑工作量均衡的条件下引入遗传算法对区域进一步调整,最后利用混合遗传算法对各配送区域进行线路优化,通过实例从线路数、车辆数、空载率、配送里程及总成本等指标上可以看出两阶段法的配送效果更优。     

一般竞争战略理论论战、观点流派与研究展望——从割裂到融合

一般竞争战略理论对企业战略决策具有广泛而深远的影响。学者们对一般竞争战略的割裂观和融合观一直争执不休，众多研究呈现出多角度、多证据、结论矛盾和研究混乱的局面。文章通过对相关理论回顾和梳理，揭示出一般竞争战略理论割裂观存在的问题和困境，呈现融合观的理论与实证证据，提炼出混合战略的三个流派，并揭示混合战略研究的脉络和趋势。文章揭示出融合是竞争战略的趋势，实现不同战略类型的融合和竞争战略的多维体系构建，有助于厘清竞争战略研究的混乱和矛盾，打破根深蒂固的“骑墙战略”禁区思维，为企业的战略决策提供系统和多维的视角，并推动一般竞争战略从割裂化向融合化演进，特别是对现阶段的中国企业战略制定具有重要意义。     

Digital Platforms and the Nature of the Firm

Abstract:

Digital platforms turn traditional approaches of the firm, which relied on the wage relation to explain the major difference between firm and market, upside down and underline the advantages of coordination through organization over coordination through market. This study aims to propose a definition of the firm able to integrate, besides the integrated firm, also hybrid forms such as networks of subcontractor/subcontracting firms as well as atypical forms such as digital platforms. By reactivating the firm-boundary problem, this article suggests putting valorization by labor at the heart of the firm’s decisions concerning integration. It suggests therefore a general definition of the firm as a techno-institutional center of capital valorization, provided that firms make profits by means of the appropriation of labor incorporated into their (productive, structural, intellectual) capital through institutional arrangements. By stressing the relation of production between the owners of the means of production and the direct producers, the approach of the firm supported here should allow to cover the different existing models of the firm, from the classical firm to hybrid models, around which the boundary debate has revolved, to digital platforms.     

天地一体化超视距雷达的激励源设计

针对单通道天地一体化超视距雷达不能多站组网的问题，设计了一种新型的激励源系统。系统利用现场可编程门阵列（FPGA）和通用串行总线（USB）实现多路发射通道控制，并通过直接数字式频率合成器（DDS）产生初始相位周期变化的线性调频波。理论分析表明，回波信号经过两次频谱变换能产生特定的多普勒频移，从而在多普勒频谱上被展开，实现信号多发一收。实验结果验证了激励源设计的可行性，可用于多站同步观测。     

基于温差发电的混合动力自行车的研究

本文主要研究了一种基于温差发电的混合动力自行车,并就其改装和发动机尾气余热利用的系统优化设计进行了集中分析,最终得出了相关结论。