动态称重系统在高速公路中的应用

车辆超载会缩短公路的使用寿命,而应用车辆动态称重系统可实现对车辆的快速称重,对治理公路超载等具有深远意义．文章介绍了动态称重系统在高速公路上的应用,并分析了该系统的组成、原理、特点及维护时应注意的问题.     

Modified efficient importance sampling for partially non‐Gaussian state space models

The construction of an importance density for partially non‐Gaussian state space models is crucial when simulation methods are used for likelihood evaluation, signal extraction, and forecasting. The method of efficient importance sampling is successful in this respect, but we show that it can be implemented in a computationally more efficient manner using standard Kalman filter and smoothing methods. Efficient importance sampling is generally applicable for a wide range of models, but it is typically a custom‐built procedure. For the class of partially non‐Gaussian state space models, we present a general method for efficient importance sampling. Our novel method makes the efficient importance sampling methodology more accessible because it does not require the computation of a (possibly) complicated density kernel that needs to be tracked for each time period. The new method is illustrated for a stochastic volatility model with a Student's t distribution.     

Microfoundations of companies' dynamic capabilities for environmentally sustainable innovation: Case study insights from high‐tech innovation in science‐based companies

To achieve sustainable development, companies are increasingly putting an emphasis on the creation and the promotion of environmentally sustainable innovations. Environmentally sustainable innovation often involves a significant shift in a new strategic direction. This paper studies this shift from a dynamic capabilities perspective and aims to identify the microfoundations of science‐based companies' dynamic capabilities for high‐tech environmentally sustainable innovations. It investigates the development of high‐tech environmentally sustainable innovations in two distinctive science‐based companies. To scholars, this study provides an in‐depth process analysis, over time, of how and why microfoundations of dynamic capabilities influence the development of a science‐based company's high‐tech environmentally sustainable innovations. To practitioners in science‐based firms, this process study can function as a frame of reference, enabling the tailoring of a strategy for high‐tech environmentally sustainable innovation.     

Could lean practices and process innovation enhance supply chain sustainability of small and medium‐sized enterprises?

Small and medium‐sized enterprises (SMEs) adopt lean practices (LP) to reduce waste across their organisational value chain, which helps achieve sustainability. Process innovation (PI) has also been applied through cleaner production, environmental management system, ecodesign, and so on to address both customers' needs and legislations by policymakers. Although prior studies reveal the effect of sustainable practices, LP, and PI on sustainable performance separately, less is known on the integrated effect of them on sustainability performance. Moreover, studies on mediating effect of LP and PI on sustainability performance are scant. This is significant as LP and PI are considered to be the enablers for achieving sustainability performance. This research addresses this knowledge gap. The research first theorises a model integrating these four major constructs (sustainability practices, LP, PI, and sustainability performance) through hypotheses development. Subsequently, using structural equation modelling, it is tested whether each of sustainability practices, LP, and PI effect sustainability performances. Additionally, mediating effect of LP and PI between sustainability practices and performances is derived. The study uses data from 119 SMEs within manufacturing industries in the Midlands, United Kingdom. Further, a few case studies have been undertaken to validate the findings from quantitative analysis. The overall results show that although sustainability practices, LP, and PI help achieve sustainability performance of SMEs supply chain through efficiency and responsiveness respectively, the mediating effect LP is more compared with PI. Moreover, SMEs adopt LP when they are economy focused and implement PI when they are pressurised by customers and/or policymakers.     

Cox Point Processes: Why One Realisation Is Not Enough

We review a rich class of point process models, Cox point processes, and illustrate the necessity of more than one observation (point patterns) in performing parameter estimation. Furthermore, we introduce a new Cox point process model by treating the intensity function of the underlying Poisson point process as a random mixture of normal components. The behaviour and performance of the new model are compared with those of popular Cox point process models. The new model is exemplified with an application that involves a single point pattern corresponding to earthquake events in California, USA.     

Points mechanisms and rewards programs

I study points programs, such as frequent flyer and other rewards programs, as a revenue management tool. I develop a two‐period contracting model where a capacity‐constrained firm faces consumers who privately learn their valuations over time. The firm cannot commit to long‐term contracts, but it can commit to allocate any unsold capacity through a points program. This points scheme creates an endogenous and type‐dependent outside option for consumers, which generates novel incentives in the firm's pricing problem. It induces the firm to screen less ex interim, and to offer lower equilibrium prices, reversing the intuition of demand cannibalization.     

A dynamic perspective: local interactions driving the spread of social networks

ABSTRACT

This study takes a micro standpoint to quantitatively verify the extent to which local interactions affect the expansion of dynamic social networks. By reviewing and synthesizing the theoretical literature in this article, we seek to establish a pragmatic analytical framework to capture the underlying functioning of local interactions. It then aims to produce findings on seven distinct marketing campaigns in which the real-world virtual communities offer intact time-series connections. In our considered cases, the firm-to-consumer interactivity plays a pivotal role in social media marketing while the customer-driven influence advances individual information transmission. The significant positive relationships demonstrate features of interactivity within subgroups including reciprocal edges and directed 3-cliques associated with the evolution of the virtual community by electronic word-of-mouth (WOM) of both firm-to-consumer and consumer-to-consumer interactions. More importantly, the attenuation of local interactions to a large extent leads to the cut-off point of the growth of the dynamic social network.     

三大都市圈与广西间入境旅游流关联度比较

京津冀、长三角、珠三角是我国三大入境旅游发达区,同时也是我国传统的大型入境口岸地区,不计其数的海外游客以其为中转地向全国各地扩散。广西是旅游业相对滞后但旅游资源丰富的典型代表之一,吸引着众多入境游客。通过对1997-2005年间京津冀、长三角、珠三角三大旅游区入境旅游流向广西扩散转移的数量变化、时间及空间分布集中性及其扩散发展历程的分析,得出结论:京津冀是广西入境旅游发展最大的中转区,长三角入境旅游转移在广西客源结构中排名第二,并保持较好的增长态势;而珠三角虽然向广西转移的入境游客数量最少,但一直保持稳定增长,具有较大发展潜力。