The issue of shared use urban freight facilities first received attention during the 1970s when it was observed that, while inter-urban freight movements were becoming increasingly efficient, there were significant diseconomies in the movement of freight via truck within urban areas. Early research suggested that shared urban freight facilities should be constructed so that trucking companies could consolidate smaller shipments into larger ones. In the past few years, the concept of Urban Ports has gained increasing attention, not just for carriers who need to load and unload freight, but to provide a place near the urban center for truckers to wait out peak traffic periods. In this paper, using recently developed survey data, we examine trucking company interest in such facilities by examining the results of an ordered probit demand model. 相似文献
Double-cantilever beam (DCB) and tapered double-cantilever beam (TDCB) specimens are the test configurations most commonly used to measure the fracture toughness of composites and adhesive joints. Strain rates of 1 to 18.47 m/s were applied to the test specimens via high-speed hydraulic test equipment. Because the fracture occurs through the adhesively bonded joints and the cracks grow rapidly, the crack length and beam displacement were recorded by a high-speed camera. An energy range from 0 to 10 J was often observed in the high-strain-rate fracture experiments for nonlinear plastic behavior of the dynamically loaded adhesively bonded DCB and TDCB specimens. The range of energy release rates (fracture energy) for TDCB specimen was 2 to 3 times higher than that of a DCB specimen for all high strain rates. The fracture energy of automotive adhesive joints can be estimated using the experimental results in this study for the fracture toughness (GIC) under high rates of loading. The crack grows as the applied fracture energy exceeds the value of the critical energy release rate (GIC) at the crack tip. The energy release rate was calculated using the fracture mechanics formula. The key fracture mechanics parameter, the fracture energy GIC, was ascertained as a function of the test rate and can be used to assess and model the overall joint performance. 相似文献
A novel regulation system for a vehicle generator and lead-acid battery is proposed in this paper. By integrating the regulation method, the output voltage of the generator is determined and controlled by the algorithm to save electrical energy and protect the lead-acid battery. The regulation algorithm is implemented in Matlab/Simulink, and the logic function of the system is verified using the dSPACE/AutoBox workbench. The experimental results show that the new algorithm improves the performance of the fuel economy of the vehicle and the battery state-of-health compared to the traditional control method. 相似文献
Transportation - Ride-hailing (ridesourcing) companies such as Uber, Lyft, and Didi Chuxing have been a disruptive force in the urban mobility landscape around the world during the past decade. In... 相似文献
Freight forecasting models have been significantly improved in recent years, especially in the field of goods vehicle behavior modeling. On the other hand, the improvements to commodity flow modeling, which provide inputs for goods vehicle simulations, were limited. Contributing to this component in urban freight modeling systems, we propose an error component logit mixture model for matching a receiver to a supplier that considers two-layers in supplier selection: distribution channels and specific suppliers. The distribution channel is an important element in freight modeling, as the type of distribution channel is relevant to various aspects of shipments and vehicle trips. The model is estimated using the data from the Tokyo Metropolitan Freight Survey. We demonstrate how typical establishment survey data (i.e. establishment and outbound shipment records) can be used to develop the model. The model captures the correlation structure of potential suppliers defined by business function and provides insights on the differences in the supplier choice by distribution channel. The reproducibility tests confirm the validity of the proposed approach, which is currently integrated into a metropolitan-scale agent-based freight modeling system, for practical use.
Objective To map a mouse deafness gene.identify the underlying mutation and develop a mouse model for human deafncss.Methods Genetic lindage cross and genome scan wer used to map a novel mutation named hypoplasia of the membranous labyrinth (hml),which causes hearing loss in mutant mice.Results ① hml was mapped on mouse Chr 10 (~43 cM from the centromere) suggests that the homologous human gene is on 12q22--q24, which was defined on the basis of known mouse-human homologies (OMIM,2004). ② This study has generated 25 polymorphic microsateUite markers, placed 3 known human genes in the correct order in a high-resolution mouse map and narrowed the hml candidate gene region to a 500 kb area. 相似文献
Introduction Structural evaluation of pavements provides awealth of information that concerns the expected be-havior of pavements[1]. Different asphalt pavementdesign and evaluation methods are described inRefs.[2-9]. Refs.[2-5,9,10] use two design meth-o… 相似文献
Optimal sequence for clearing snow from the manoeuvring area of an airport.
Contains optimising algorithms solved using CPLEX LP‐based tree search.
Restrictions on partial fulfilment of operational targets applied to subsets of significant stretches, used for planning the operation of snow‐clearing machines.
Model applied to the case of the manoeuvring area of Adolfo Suárez Madrid Barajas Airport.
Conclusions are given on the results of the computational tests carried out. There are five models of the manoeuvring area which cover increasingly complex situations and larger areas.
Many researches have been conducted in the area of control applied to vehicle dynamics, aiming at reducing the possibility of the occurrence of the type of accident known as rollover. In this research, based on a common nonlinear model and its linearisation, a method for properly selecting matrices for solving the Riccati equation considering different speeds was proposed. The method showed in which ways speed really influences the choice of controller gains. By developing the dynamic equations for the yaw- and roll-coupled motions and modelling of controllers and state observers, it is possible to compare the efficacy of this control strategy using both linear and nonlinear simulations using Matlab. Significant results were obtained regarding the reduction of the rollover coefficient for a double-lane change manoeuvre at different speeds, thus indicating advantages of using this controller in practical cases. 相似文献