Port performance in Asia: Does production efficiency imply environmental efficiency?

Atmospheric and water pollution are two main sources of negative environmental externalities generated by shipping. This study recognizes the negative externalities in the production of port services in East Asia by explicitly incorporating environmental impacts of shipping. Programming techniques are used to analyze 156 Origin–Destination pairs between 13 major East Asian ports, to derive the externality-augmented measures of port productivity and efficiency at the waterside. The results suggest that the inclusion of externality mitigation strategies can exert a considerable influence on efficiency performance.     

The influence of workplace environment on lung function of shopkeepers working near National Highway in Jalgaon: A note

The inferior ambient air quality was observed near highway passing through Jalgaon urban center. Among the pollutants critical level of particulates are observed at the roadside during May 2003 to April 2004. The shopkeepers working at the highway sides are at high risk of exposure to the air pollution caused by heavy highway traffic. The lung function test of the shopkeepers shows significant decrease in forced vital capacity, forced expiratory volume in one second and peak expiratory flow rate. The regular periodic health checkup and use of nose mask will protect the health of shopkeepers working near National Highway passing through Jalgaon urban center.     

Surrounding Rock Classification of Banxi Group Slate with Abundant Water北大核心CSCD

For water-rich slate, surrounding rock argillization and softening is a serious problem. At present the uni-axial saturated compressive strength of rock is used as one of the indexes for classification of water-rich slate sur-rounding rock. Since Banxi Group slate has special geological characteristics, the above mentioned grading index is not completely suitable for its surrounding rock classification due to limitations. For this reason, using the Youfang-ping tunnel at the Changsha to Kunming Section of the Shanghai to Kunming high-speed railway in China as an ex-ample, a softening coefficient is introduced, and the underground water, rock mass integrity coefficient and angle of the main structural surface and tunnel axis are regarded as the main controlling factors. A system of surrounding rock classification for tunnels in water-rich slate is established. Based on the theory of fuzzy mathematics, the member-ship function of each index is structured and the weight of each index is calculated by AHP, and the grade of the sur-rounding rock is determined according to the maximum membership degree principle. The results show that the fuzzy information of surrounding rock classification is processed effectively and the classification of surrounding rock is achieved by qualitative analysis to quantitative evaluation by using fuzzy theory. The surrounding rock classification determined by introducing the softening coefficient on the basis of fuzzy theory is close to that determined in practical application, indicating that the practicability of this classification of tunnel surrounding rock in water-rich slate is high. This classification system therefore is a reference for the design and construction of tunnels in water-rich slate. © 2018, Editorial Office of "Modern Tunnelling Technology". All right reserved.     

Highway Tunnel Blasting Vibrations and Cracking of Adjacent Residential Houses北大核心CSCD

A systematic analysis and discussion of the causes of house cracking are conducted by testing the blast vibration velocity of typical neighboring houses, analyzing the types of house cracking, monitoring the characteris-tics of house cracks and calculating the temperature stress at the roof and wall based on an assessment of highway tunnel blasting vibrations leading to cracking of neighboring houses. The results show that the main cause of house cracking adjacent to the tunnel is temperature stress, not blasting vibration. © 2018, Editorial Office of "Modern Tunnelling Technology". All right reserved.     

Impact of different shopping stages on shopping-related travel behaviour: analyses of the Netherlands Mobility Panel data

From the moment e-shopping emerged, there have been speculations about its impact on personal mobility. A fair amount of research has already been carried out on Internet shopping itself as well as on its consequences for mobility. Most studies focus on the overall impact of online shopping on personal mobility. However, little is known about how personal shopping mobility can be characterised when differentiating its constituent stages, being browsing/orienting, comparing, selecting and purchasing products, and how this is affected by e-shopping. This will be the main topic of this paper. We will investigate this using recently collected data from the Netherlands Mobility Panel [in Dutch: MobiliteitsPanel Nederland (MPN)]. It is the unique combination of reported shopping trips in the three-day travel diary, the large amount of personal and household characteristics combined with the detailed information from the e-shopping questionnaire that enables us to perform this research. Using factor analysis, we explore the underlying factors related to the browsing and selection behaviour prior to the purchase of a product. Using these factors as a starting point, we apply cluster analysis resulting in three homogeneous groups of shoppers with different pre-purchase shopping behaviour. The groups differ clearly with respect to personal and household characteristics, in the frequency with which they buy and sell products online and in their perception of (dis-)advantages of online shopping. Once relevant groups have been distinguished and characterised, differences in shopping-related mobility between them are studied in two different ways. Firstly, we analyse statements from shoppers on how their shopping-related mobility has changed. Secondly, we analyse shopping trips reported in the three-day travel diary. Only one group, which consists of shoppers that rely on the Internet to search for product information, compare prices and get new product ideas, states that their shopping-related travel behaviour has changed since they started shopping online. Approximately 50% of all shoppers experienced no difference in their shopping mobility. The analysis of actual shopping mobility using the travel diary data showed only minor differences in shopping-related travel behaviour between the identified groups. Finally, we fit a multi-variate linear regression model of shopping trip distance to determine if (e)-shopping characteristics influence trip distances. The frequency with which people shop online as well as some stated changes in shopping-related travel behaviour (shopping in a similar manner and shopping longer) turn out to influence non-grocery shopping trip distance. No significant influence could be found of shopping cluster membership on shopping trip distances.

     

A dynamic model of travel mode switching behaviour

An analogy is developed between individual traveler mode choice decisions and time-dependent product adoption processes in consumer behaviour. The structure of the adoption sequence is first described conceptually with reference to mode switch ing; this structure is then used to develop a simple mathematical model of mode switching behaviour over time. Factors to be considered in interpreting and operationalizing the model are then discussed at some length. The model appears too complex for direct mathematical solution except in the simplest cases; it may however, be amenable to numerical estimation, given empirical data on mode switching behaviour over time.     

Non-linear dynamic simulation of gear response under the idling condition

A dynamic lumped-parameter gear model incorporating the effects of a time-varying and asymmetric mesh stiffness and a backlash nonlinearity is formulated to analyze the spur gear rattle response under the idling condition. The proposed theory assumes a rectangular time-varying mesh stiffness function. The phase shift between the mesh stiffness for forward and backward contacts is examined. Numerical studies are employed to examine the effects of engine torque fluctuations and tooth surface friction on the gear rattle response and the corresponding tooth impact behavior. Comparisons between the results from the time-invariant mesh stiffness model and the proposed time-varying mesh stiffness model reveal differences in the gear responses, especially when the mean rotational speed of the fluctuating gear pair is non-zero. The analysis reveals significant effects on the high frequency response components. However, the idling gear dynamics are relatively insensitive to tooth surface friction.     

Numerical investigation on the dynamic characteristics of an automotive A/C hose

The objective of this study is to investigate the dynamic deformation characteristics of an automotive A/C hose assembly using the finite element method and experimentation. The finite element analysis consisted of two analyses, specifically, a modal and a transient analysis. The dynamic modal analysis was conducted to assess the dynamic characteristics of the A/C hose structure, and the dynamic transient analysis was performed to investigate the dynamic stresses of an automotive A/C hose by dynamic loading with particular emphasis on the reinforced braid. Furthermore, the analyses results are expected to provide useful reference data in the design optimization of the hose layout related to the constrained design space. Modal testing was undertaken to verify the FE model. The FE result was in good agreement with the experimental results. The modal analysis result showed that the bending and swing modes of the hose occurred in the first six natural frequencies. The dynamic transient result showed that the maximum stress in the hose components occurred in the reinforced braid layers, which are particularly damage-prone.