MANAGING THE ENVIRONMENTAL EXTERNALITIES OF TRAFFIC LOGISTICS: THE ISSUE OF EMISSIONS

Companies are increasingly being held accountable for the life‐cycle impact of their products and services. Transportation is frequently a major component of this life‐cycle impact. Hence, to reduce total environmental impact, logistics managers will have to become more sophisticated in their understanding of how they can reduce the environmental impact of their transportation operations, without negatively affecting the cost or effectiveness of these operations. In line with this mandate, we quantify the dynamic impact of road vehicles on the environment. In most emission models, a constant speed is used depending only on the specific road type. Using such a model will lead to an underestimation of the effective emissions. It turns out that the differences with a more realistic dynamic assessment model are significant. The analysis here suggests that the policy consequences of these differences for both public sector managers and private companies are potentially quite important.     

城市路网运输性能退化成本评估模型

路网的运行受到诸多因素的影响而使得路网运输性能发生退化,分析了路网运输性能退化的影响因素和作用机理,给出了路网运输性能退化及退化的极端情况路段失效的成本分析过程框架.基于BPR路阻函数和用户均衡分配理论分析路网运输性能退化的成本函数,建立了拥堵情况下城市路网路段失效的成本评估模型.最后,通过实例分析了路网运输性能退化对出行成本影响的变化规律,给出了路网运输性能退化的极端情况路段失效成本评估的具体过程,研究表明路网运输性能退化对出行成本具有很大的影响,二者成显著的正相关关系.     

From blind spots to hotspots: How knowledge services clusters develop and attract foreign investment

This paper explores local and global dynamics underlying the development of knowledge services clusters, which we define as new geographic concentrations of technical talent and service providers offering upstream technical and knowledge-intensive business services to regional and global clients. Taking a co-evolutionary perspective on the development of knowledge services clusters in Latin America, based on data from the Offshoring Research Network (ORN), we find that cluster growth results from intersecting trajectories: the emergence of local talent pools and capabilities initially serving local and regional demand; broadening global search for talent and expertise by multinational corporations; and internationalization strategies of service providers competing to serve global clients. Findings suggest that increasing commoditization of knowledge services opens up windows of opportunity for new clusters, but also involves challenges for sustainable growth. Results may stimulate future research on global sourcing and cluster development.     

基于韧性城市视角的冰雪天气下路网恢复问题研究

城市的快速发展使其愈加依赖于生命线基础设施系统，城市在自然或人为突发事件面前的脆弱性日益凸显，城市面对突发事件后的运行与恢复问题受到广泛关注。冬季极端冰雪天气对城市路网系统带来极大冲击，严重降低路网服务能力。本文基于韧性城市视角，对冰雪天气下城市路网韧性的概念和度量方法进行了分析。以提升路网韧性为目标，建立冰雪天气下路网恢复问题的数学模型，解决极端冰雪天气不确定信息下的城市路网除雪应急物资布局问题及其除雪作业优化问题，并设计了相应的启发式求解算法。最后通过算例验证了模型和算法的有效性，以期为城市冰雪天气应对提供决策支持，提升城市应对极端冰雪天气的韧性。     

Safety Regulations and the Uncertainty of Work-Related Road Accident Loss: The Triple Identity of Chinese Local Governments Under Principal–Agent Framework

This study examines how government safety regulations affect the uncertainty of work-related road accident loss (UWRAL) by considering the multi-identity of local governments in the relationship among the central government, the local governments, and enterprises. Fixed effects panel models and mediation analyses with bootstrapping were conducted to test the hypotheses using Chinese provincial panel data from 2008 to 2014. Given the complexity and nonlinear characteristics of road safety systems, a new approach based on self-organized criticality theory is proposed to measure the uncertainty of road accident loss from a complex system perspective. We find that a regional government with detailed safety work planning (SWP), high safety supervision intensity (SSI), and safety information transparency (SIT) can decrease the UWRAL. Furthermore, our findings suggest that SSI and SIT partially mediate the relationship between the SWP of regional governments and the UWRAL, with 19.7% and 23.6% indirect effects, respectively. This study also provides the government with managerial implications by linking the results of risk assessment to decision making for risk management.     

基于系统最优的城市公交专用道网络设计模型及算法

设置公交专用道是实现"公交优先"的重要手段,然而,专用道设置将改变不同交通方式的道路通行能力,进而影响交通网络的整体性能。本文试图提出一种基于系统最优思想的公交专用道网络设计方法,既保证出行者的利益,又能满足交通系统总费用最优的目标。首先,本文分析了公交专用道设置对公交车辆和社会车辆这两种交通方式道路通行能力的影响,基于经典的BPR函数,构造了考虑专用道设置的不同方式的路段阻抗函数。其次,分析了出行者在多方式交通网络中的模式选择和路径选择问题,采用用户平衡理论分析了城市多方式交通平衡配流问题,给出了相应的变分不等式模型。更进一步,采用双层规划方法构造了基于系统最优的城市公交专用道网络设计模型,该模型以交通网络总费用最小为优化目标,并考虑了不同交通方式的平衡流量约束,采用分支定界算法对该双层规划模型进行求解。最后,通过一个简单算例对模型及算法的可行性和有效性进行了分析和验证。     

Interruption and Forgetting in Knowledge‐Intensive Service Environments

An increasing barrier to productivity in knowledge‐intensive work environments is interruptions. Interruptions stop the current job and can induce forgetting in the worker. The induced forgetting can cause re‐work; to complete the interrupted job, additional effort and time is required to return to the same level of job‐specific knowledge the worker had attained prior to the interruption. This research employs primary observational and process data gathered from a hospital radiology department as inputs into a discrete‐event simulation model to estimate the effect of interruptions, forgetting, and re‐work. To help mitigate the effects of interruption‐induced re‐work, we introduce and test the operational policy of sequestering, where some service resources are protected from interruptions. We find that sequestering can improve the overall productivity and cost performance of the system under certain circumstances. We conclude that research examining knowledge‐intensive operations should explicitly consider interruptions and the forgetting rate of the system's human workers or models will overestimate the system's productivity and underestimate its costs.     

The Influence of Task Interruption on Individual Decision Making: An Information Overload Perspective

Interruptions are a common aspect of the work environment of most organizations. Yet little is known about how interruptions and their characteristics, such as frequency of occurrence, influence decision-making performance of individuals. Consequently, this paper reports the results of two experiments investigating the influence of interruptions on individual decision making. Interruptions were found to improve decision-making performance on simple tasks and to lower performance on complex tasks. For complex tasks, the frequency of interruptions and the dissimilarity of content between the primary and interruption tasks was found to exacerbate this effect. The implications of these results for future research and practice are discussed.     

Multi-objective optimization in partitioning the healthcare system of Parana State in Brazil

Motivated by a proposal of the local authority for improving the existing healthcare system in the Parana State in Brazil, this article presents an optimization-based model for developing a better system for patients by aggregating various health services offered in the municipalities of Parana into some microregions. The problem is formulated as a multi-objective partitioning of the nodes of an undirected graph (or network) with the municipalities as the nodes and the roads connecting them as the edges of the graph. Maximizing the population homogeneity in the microregions, maximizing the variety of medical procedures offered in the microregions, and minimizing the inter-microregion distances to be traveled by patients are considered as three objective functions of the problem. An integer-coded multi-objective genetic algorithm is adopted as the optimization tool, which yields a significant improvement to the existing healthcare system map of the Parana State. The results obtained may have a strong impact on the healthcare system management in Parana. The model proposed here could be a useful tool to aid the decision-making in health management, as well as for better organization of any healthcare system, including those of other Brazilian States.     

雪灾救援物资车辆-直升机联合运送的调度问题研究

文章研究了雪灾救援中车辆与直升飞机联合运输应急物资的调度问题。在道路疏通能力与整体救援时间有限的情况下,首先决策需要疏通的道路,及其疏通顺序,对疏通后的需求点采用汽车运输补给,该阶段决策目标为汽车运输量最大化;然后调度直升飞机对各点疏通前的物资短缺以及未疏通的需求点进行物资运输,设计每架直升机的飞行路线与各点投放量,使得两个阶段运输完成后,最大化所有需求点中最小物资可维持时间。文章对两个阶段分别建立混合整数规划模型,并设计启发式算法,最后以西北某区域的路网结构为例,设计了数值算例。     

Integration of Critical Infrastructure and Societal Consequence Models: Impact on Swedish Power System Mitigation Decisions

Critical infrastructures provide society with services essential to its functioning, and extensive disruptions give rise to large societal consequences. Risk and vulnerability analyses of critical infrastructures generally focus narrowly on the infrastructure of interest and describe the consequences as nonsupplied commodities or the cost of unsupplied commodities; they rarely holistically consider the larger impact with respect to higher‐order consequences for the society. From a societal perspective, this narrow focus may lead to severe underestimation of the negative effects of infrastructure disruptions. To explore this theory, an integrated modeling approach, combining models of critical infrastructures and economic input–output models, is proposed and applied in a case study. In the case study, a representative model of the Swedish power transmission system and a regionalized economic input–output model are utilized. This enables exploration of how a narrow infrastructure or a more holistic societal consequence perspective affects vulnerability‐related mitigation decisions regarding critical infrastructures. Two decision contexts related to prioritization of different vulnerability‐reducing measures are considered—identifying critical components and adding system components to increase robustness. It is concluded that higher‐order societal consequences due to power supply disruptions can be up to twice as large as first‐order consequences, which in turn has a significant effect on the identification of which critical components are to be protected or strengthened and a smaller effect on the ranking of improvement measures in terms of adding system components to increase system redundancy.     

Understanding the consequences of public social media use for work

Social media has slowly become ubiquitous in the workplace; however, the use of these technologies has been associated with both positive and negative consequences. Using the JD-R model, this study examines these positive and negative consequences of the public social media use for work. Survey data of 421 employees is used to explore the relationship between public social media use for work and engagement, and exhaustion, through opposing mechanisms. The findings demonstrate that interruptions and work–life conflict are important demands, whereas accessibility and efficient communication are resources associated with social media use for work. These demands and resources are related to engagement and exhaustion.     

Determinants of Citizen Usage Intentions in e-Government: An Empirical Analysis

Local governments have implemented official websites, making e-Government a holistic access platform for modern public administration service provision. However, academic and managerial knowledge about the success of e-Government remains limited. Given that citizen needs have become a focus of interest, it is reasonable to investigate its success factors from a user-oriented perspective. Existing scientific knowledge does not comprehensively explain the usage intentions of today’s heterogeneous e-Government city portal users. Hence, this study conceptualizes important determinants of local e-Government portals identifying key factors that determine intention to use from a citizen viewpoint.     

Toward Disaster‐Resilient Cities: Characterizing Resilience of Infrastructure Systems with Expert Judgments

Resilient infrastructure systems are essential for cities to withstand and rapidly recover from natural and human‐induced disasters, yet electric power, transportation, and other infrastructures are highly vulnerable and interdependent. New approaches for characterizing the resilience of sets of infrastructure systems are urgently needed, at community and regional scales. This article develops a practical approach for analysts to characterize a community's infrastructure vulnerability and resilience in disasters. It addresses key challenges of incomplete incentives, partial information, and few opportunities for learning. The approach is demonstrated for Metro Vancouver, Canada, in the context of earthquake and flood risk. The methodological approach is practical and focuses on potential disruptions to infrastructure services. In spirit, it resembles probability elicitation with multiple experts; however, it elicits disruption and recovery over time, rather than uncertainties regarding system function at a given point in time. It develops information on regional infrastructure risk and engages infrastructure organizations in the process. Information sharing, iteration, and learning among the participants provide the basis for more informed estimates of infrastructure system robustness and recovery that incorporate the potential for interdependent failures after an extreme event. Results demonstrate the vital importance of cross‐sectoral communication to develop shared understanding of regional infrastructure disruption in disasters. For Vancouver, specific results indicate that in a hypothetical M7.3 earthquake, virtually all infrastructures would suffer severe disruption of service in the immediate aftermath, with many experiencing moderate disruption two weeks afterward. Electric power, land transportation, and telecommunications are identified as core infrastructure sectors.     

供应链中断下顾客缺货反应对牛鞭效应的影响研究

传统的关于供应链牛鞭效应的研究,仅关注供应链上游成员间（供应商、制造商或零售商）的协调运作,而忽略缺货发生后顾客缺货反应对供应链动态性的影响。本文利用高层级Petri-net对包含两个制造商、两个零售商的供应链系统进行建模与仿真,定量地研究不同的缺货强度下顾客缺货反应对两条相互竞争的供应链牛鞭效应的影响。研究结果表明,顾客缺货反应对缺货品牌及其竞争品牌的牛鞭效应均存在显著影响,但各种缺货反应对牛鞭效应的影响程度有所差异,且供应链中断强度（主要体现为发生缺货的品牌市场份额以及缺货持续时间）亦对牛鞭效应产生显著影响。我们建议不同产品类型（对应不同的顾客反应组合）的管理者根据品牌的市场占有率、缺货持续时间等因素对不同类型的顾客进行购买行为的引导,以缓解牛鞭效应并保持市场份额。     

城市道路交通网络容量的建模

交通网络承载着具有意志行为的个体组成的交通流,交通网络容量表示道路网络的交通承载能力,与交通网络的OD结构密切相关.本文在分析城市道路交通网络OD结构特征的基础上,提出表达道路网络容量的基本思想和模型,阐明交通网络容量受到交通流特性、网络要素容量、废气排放量、服务水平和系统效率等因素的影响,基于不同的考虑方法可以建立不同的网络容量模型.基于路段容量约束的网络容量描述了道路系统承载交通流的物理极限;基于路段容量约束和交通环境约束的网络容量则描述了道路系统承载交通流的环境极限;基于服务水平的网络容量描述了系统提供某种服务水平条件下的最大交通承载能力;基于效率的网络容量描述了网络资源使用效率和用户效益同时最大化条件下的道路网络承载能力.文章深入分析了所提出的各种模型之间的关系,在实际应用中可根据交通规划和管理所追求的具体目标,采取相应的模型.     

考虑人车混采的道路信息采集的路径规划研究

本文考虑了道路信息外业采集的任务要求，人车混采的采集方式以及路网特性等方面，为道路信息采集人员的路径规划建立了满足人车混采约束的整数规划模型；提出了分阶段的转化算法，将其逐步转化为有限时间容量限制的弧路径问题(TCARP)。TCARP问题是一种NP-hard问题，精确求解算法无法在合理时间内得到问题的最优解，因此本文设计了求解TCARP问题的两种快速启发式算法TPS和TUH及其随机化版本；考虑到实际采集问题的大规模特性，在两种快速启发式算法的基础上构造GRASP-PA寻优算法。最后分别结合不同规模的基准算例和实际采集算例证明了本文所构造的算法的有效性。     

Capturing the benefits of industry 4.0: a business network perspective

Abstract

This study uses a business network perspective to investigate the industry 4.0 context with the internet of things (IoT) as its enabling technology and product-use data as its core network resource. A three-stage qualitative methodology (interviews, focus group, Delphi-based inquiry) was used to examine the case of an emergent IoT-based business network in the UK road transport industry to examine: (i) how aspects of product use data influence the benefit opportunities the data provide to the different network actors; (ii) how capturing of the benefit opportunities in a network context is impacted by key barriers; and (iii) how network capabilities can overcome these barriers to capture benefits from product-use data. The study, thereby, contributes to an understanding of the industry 4.0 context from a resource dependency theory perspective and provides concrete recommendations for management operating in this context.     

中国股票市场多重分形游走及其预测

股票价格波动规律的研究是预测的基础,多重分形过程是迄今为止最为符合价格波动特性的模型。本文验证了中国股票市场的多重分形游走,并根据多重分形过程的局部尺度特性和多尺度相关性建立了小波和神经网络相结合的股票价格预测模型。实证研究结果表明,本文模型预测精度较由其他模型得到的预测精度明显提高。