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1.
Recent empirical assessments revealed that footprint indicators calculated with various multi-regional input–output (MRIO) databases deliver deviating results. In this paper, we propose a new method, called structural production layer decomposition (SPLD), which complements existing structural decomposition approaches. SPLD enables differentiating between effects stemming from specific parts in the technology matrix, e.g. trade blocks vs. domestic blocks, while still allowing to link the various effects to the total region footprint. Using the carbon footprint of the EU-28 in 2011 as an example, we analyse the differences between EXIOBASE, Eora, GTAP and WIOD. Identical environmental data are used across all MRIO databases. In all model comparisons, variations in domestic blocks have a more significant impact on the carbon footprint than variations in trade blocks. The results provide a wealth of information for MRIO developers and are relevant for policy makers designing climate policy measures targeted to specific stages along product supply chains.  相似文献   
2.
The centrality of cross‐functional integration (CFI) to supply chain theory and practice has long been recognized. Yet researchers continue to struggle with consistently defining or measuring the CFI construct, thus limiting the utility of CFI research. This research develops (1) a comprehensive definition of CFI that synthesizes previous supply chain research and (2) a valid set of scale items that measure the conceptual domain outlined by this definition. The goal is to build a common foundation for extending knowledge on CFI's antecedents and consequences, and ultimately to improve scholars’ ability to guide a broader practitioner community still struggling to achieve integration in their organizations.  相似文献   
3.
In recent years, cities have become ever more attractive to middle‐class families. On the one hand, middle‐class families tend to withdraw into (often newly built) socially homogeneous middle‐class neighbourhoods. On the other hand, they are also known to move into inner‐city and socially mixed areas, thus triggering processes of gentrification. Academic literature has often denounced these housing choices as being either ‘separatist’ or ‘revanchist’, more broadly categorized as strategies of ‘middle‐class disaffiliation’. Although there is a grain of truth in these interpretations, the reality is certainly more complicated. In our research on middle‐class parents’ housing and neighbourhood choices as well as their patterns of neighbourhood use, carried out in each of the two types of residential area mentioned above, we have only very rarely found an explicit desire to draw boundaries that exclude those ‘beneath’ them. We rather argue that the housing choices and neighbourhood‐related activities of middle‐class family households are heavily influenced by the specific dilemmas the interviewees face as (working) urban parents. While a significant number of respondents worry about the social sustainability, justice and cohesion of urban society, they are also concerned about the future prospects of their children. Many find it difficult to reconcile these conflicting normative demands under the prevailing circumstances.  相似文献   
4.
组网是卫星、无人机等飞行器集群实现协同的基础。传统自组织组网技术针对地面随机移动场景设计,不适用于拓扑和传输根据任务变化的飞行器集群场景,为此设计了一种管理与任务分离的组网方法,将网络分为管理面和任务面两个逻辑层面,管理面负责拓扑发现、路由建立、任务规划等基础组网功能,任务面负责任务执行过程中的数据传输功能。管理面和任务面实行不同的组网策略,从而使得网络的传输性能根据管理和任务执行的不同需求进行优化,以减少协议开销及降低传输自干扰。  相似文献   
5.
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。  相似文献   
6.
With the rapid urbanization in China, land resources are becoming increasingly scarce. Identifying and resolving land use conflict is essential for reasonably using land resources and achieving land sustainability. Taking the middle reaches of the Heihe River as an example, we included the constraints of local water resources to construct a multi-criteria evaluation system for assessing land use competitiveness in 2000 and 2015 based on land use, socio-economic, and nighttime light data. By comparing the competitiveness of cultivated land, construction land and ecological land, we then derived the spatiotemporal patterns of potential land use conflicts. Actual land use changes supported the hypothesis that land use tended to convert into the type with higher competitiveness at areas with intense conflict, which better indicated that our assessment model was effective. The results showed that the potential land use conflict was more acute in the central and northwest but weak in the southeast and northeast, and its pattern showed a significantly positive spatial autocorrelation. The conflict between cultivated land and construction land was most prominent and mainly occurred in the transitional zone from urban to rural areas. Rapid urban development and water shortage were the main causes of the potential land use conflict. Assessing land use multi-functions and making a tradeoff among ecological, economic, and social services will be an effective way to guide future land use to solve land use conflict. Our research provides scientific evidence for sustainable land use planning and management in the arid areas.  相似文献   
7.
研究目的:探讨耕作层土壤剥离再利用空间配置思路与方法,并以南昌市为例进行实证研究,为相关工作提供借鉴。研究方法:提出基于线性规划及OD成本矩阵方法的两次平衡计算的耕作层土壤剥离再利用土方空间配置思路。首先,确定剥离、覆土优先度并结合供求关系划定供需圈,在供需圈内部进行第一次调配平衡;其次,对于内部不能平衡的供需圈,进行第二次跨圈调配平衡,达到缩短运输距离,控制成本目的。研究结果:(1)南昌市耕作层剥离量能够满足覆土数量与质量的需求;(2)空间配置结果共划定18个供需圈,供需圈内土方调配加权平均运输距离为6 682 m,小于期望值10 km,满足项目实施要求;(3)共有15个供需圈存在土方量不平衡问题,跨圈调配的距离平均为72 071 m,满足短距离运输的要求。研究结论:以耕作层土壤剥离、覆土优先度及供求关系为基础划定供需圈,基于线性规划及OD成本矩阵的两次平衡计算的空间配置思路与方法,可以优化运输距离,减少运输成本,提高项目实施效益。本文提出的空间配置思路可以为耕作层剥离再利用工程的顺利实施提供理论与方法借鉴。  相似文献   
8.
为保障多输入多输出窃听信道系统中信息传输的保密性,提出了一种基于机器学习的天线选择方案。首先利用机器学习解决分类问题准确率高、处理大数据高效这一优势,设计了基于奇异值分解的特征值提取、基于信干噪比的标签赋值方案,建立了k最近邻分类器和逻辑回归分类器选择最优天线最大化保密性能(可达保密速率和保密中断概率)。与传统天线选择方案相比,所提方案获得了几乎一致的保密性能,并且大幅降低了系统的选择复杂度和误比特率。  相似文献   
9.
The entire food value chain and diet of low and middle income countries (LMICs) are rapidly shifting. Many of the issues addressed by the nutrition community ignore some of the major underlying shifts in purchases of consumer packaged foods and beverages. At the same time, the drivers of the food system at the farm level might be changing. There is a need for the agriculture and nutrition communities to understand these changes and focus on some of their implications for health. This rapid growth of the retail sector will change the diets of the food insecure as much as that of the food secure across rural and urban LMIC’s. This short commentary contents that current research, programs and policies are ignoring these rapid dynamic shifts.  相似文献   
10.
于淼 《商业研究》2005,(11):81-84
电子结算作为一种新兴的在线资金交换方式,解决了人们跨地域经济活动的关键问题。由于其在大额与小额结算方面的应用,提高了金额系统资金的周转速度和使用效率,节省了服务成本。相比于发达国家,我国实现电子结算的业务比重仍然偏低,但成长势头良好,如果能解决目前在认证、安全、法律等几个方面存在的漏洞,会有助于其更广泛的应用。  相似文献   
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