Transport deregulation and the economy wide implications of the wheeler‐Gilmour hypothesis

This paper focuses on the effects of deregulation of motor carriers in Australia. It is particularly concerned with the implications of regulatory reform beyond the transport sector and uses a general equilibrium approach to examine the economy wide effects of deregulation. Among other things the paper shows that the effects of deregulation are not evenly distributed across all types of industries. Furthermore it concludes that the magnitude of the effects from deregulation in any given industry is not necessarily correlated with the share of total costs devoted to the purchase of transportation services.

     

Assessing land‐use regulations in coastal wetlands: The case of the long point area,lake Erie,Ontario

Abstract

The first comprehensive attempt at development control along the Canadian Great Lakes shoreline was the 1976 lakeshore regulation policy adopted by the Regional Municipality of Haldimand‐Norfolk on the north Lake Erie shore. This innovative strategy was initiated at the municipal level as a component of the regional land‐use planning process. Determination of efficiency and effectiveness of the policy implementation process is based on analysis of permit approval files. All development applications submitted between 1976 and 1980 in the Turkey Point and Long Point Peninsulas are evaluated. Those areas, the most popular cottaging areas in the region, are most susceptible to flood and erosion hazards. Of the total applications submitted during the four‐year study period, 37 percent were in these areas. The policy was ineffective and inefficient in controlling development in the two peninsulas. Applications were approved in the majority of cases, despite regulatory prohibition of developments in hazard‐susceptible areas. There were lengthy decision‐making delays, often exceeding one year, and frequent violations of regulatory procedures. Recommendations are suggested to improve policy implementation.     

Enjeux de la mise en accessibilité des transports publics: le rôle de la maîtrise d’usage et de la coproduction

Since the act of February 11, 2005, the policy objective is to make urban projects accessible for all. This political context is strengthened on one hand by a greater social demand relieved by associations, and on the other hand by the need to anticipate the consequences of ageing population. A qualitative survey conducted in the metropolitan areas of Paris and Grenoble, with representatives of associations, transport operators, communities, and experts, shows that the law is not enough. The issue of a successful accessibility lies particularly in the political will at local level and in the involvement of people to overcome flaws in local projects, through consultation and coproduction initiatives. The users’ knowledge makes the project evolving and adapting according to social demand. The user has an expertise gained from his experiences that no one can match. Therefore, it has a vital role in the development, implementation and evaluation of projects’ accessibility.     

Hybrid modeling of seat-cab coupled system for truck

For the complex structure and vibration characteristics of the seat and cab system of truck, there is no reliable theoretical model for the suspensions design at present, which seriously restricts the improvement of ride comfort. In this paper, a 4 degree-of-freedom seat-cab coupled system model was presented; using the mechanism modeling method, its vibration equations were built; then, by the tested cab suspensions excitations and seat acceleration response, its parameters identification mathematical model was established. Combining the tested signals and a simulation model with the parameters identification mathematical model, a new method of hybrid modeling of seat-cab coupled system was presented. With a practical example of seat and cab system, the parameters values were identified and validated by simulation and test. The results show that the model and method proposed are correct and reliable, and lay a good foundation for the optimal design of seat suspension and cab suspensions to improve ride comfort.     

Dynamic location: an iconic model to synchronize temporal and spatial transportation data

This paper describes a model to synchronize the management and query of temporal and spatially referenced transportation data in geographic information systems (GIS). The model employs a method referred to as dynamic location, which facilitates spatial intersect queries from geographic shapes without the use of topological relationships. This is the inverse of how dynamic segmentation works in GIS. In contrast to dynamic segmentation, dynamic location stores geometry as an object within a single database field. This is an efficient, precise iconic model superseding the need for data decomposition into a complex set of tables. As an object model, the dynamic location process lends itself to high performance in an Internet, data-intensive, enterprise environment. Linear events are stored as {x, y} features, and not referenced to any route system. Route systems are built from {x, y, m} values (m for measure) and serve as number lines for mathematical operations. Any {x, y} object can then be referenced to either the Cartesian grid or any selected number line. This method offers the benefits of linear referencing, while making full use of a stable geodetic datum. Combinations of any {x, y} events may be placed over any {x, y, m} number line (route) and an intersect determined by looking through stacked {x, y, m} vertices of the coincident shapes. Since both geometry and shape reside in the same record, the use of “begin” and “end” dates facilitates full spatial and temporal version control. From a business process perspective, this creates a spatially enabled database, pulling GIS business functions back into the information technology mainstream.     

Nonlinear adaptive sliding mode control for vehicle handling improvement via steer-by-wire

This paper proposes a nonlinear adaptive sliding mode control that aims to improve vehicle handling through a Steer-By-Wire system. The designed sliding mode control, which is insensitive to system uncertainties, offers an adaptive sliding gain to eliminate the precise determination of the bound of uncertainties. The sliding gain value is calculated using a simple adaptation algorithm that does not require extensive computational load. Achieving the improved handling characteristics requires both accurate state estimation and well-controlled steering inputs from the Steer-By-Wire system. A second order sliding mode observer provides accurate estimation of lateral and longitudinal velocities while the driver steering angle and yaw rate are available from the automotive sensors. A complete stability analysis based on Lyapunov theory has been presented to guarantee closed loop stability. The simulation results confirmed that the proposed adaptive robust controller not only improves vehicle handling performance but also reduces the chattering problem in the presence of uncertainties in tire cornering stiffness.     

New insights from fractional order skyhook damping control for railway vehicles

Active suspensions for railway vehicles have been a topic of research for a number of decades and while their applications in service operation are limited, it seems clear that they will in due course see widespread adoption. Railway suspension design is a problem of compromise on the non-trivial trade-off of ride quality versus track following (guidance), and the skyhook damping control approach has been paramount in illustrating the potential benefits. Since skyhook damping control, various advanced control studies appeared contributing to redefine the boundaries of the aforementioned trade-off. Yet there is no study on the impact of fractional order (FO) methods in the context of skyhook railway active suspensions and in particular related to skyhook damping control. This is the area to which this paper strongly contributes. We present findings from a current project on FO controllers for railway vehicles active suspensions, in particular work on the effect of FO methods in basic skyhook damping control schemes, i.e. pure and intuitively based skyhook. First, we present a brief review of conventional skyhook damping control and then proceed to a rigorous investigation of the impact of FO on the ride quality/track following trade-off. The relevant benefits from FO methods are appraised and new insights highlighted.     

Daily and seasonal variations of the partial pressure of CO2 in surface seawater along Belgian and southern Dutch coastal areas

The variations of the partial pressure of CO₂ (pCO₂) and related parameters were determined in surface seawater along the Belgian coast, from January 1995 to June 1996, at both daily and seasonal time scales. The distribution of pCO₂ in this area is regulated by river input from the Scheldt, biological activity and hydrodynamics. The contribution of each of these processes varies as a function of the considered time scale: (i) the daily variation of pCO₂ depends on the tide although modulated by the biological diel cycle; (ii) the seasonal variation of pCO₂ depends on the input from the Scheldt and the seasonal variations of phytoplanktonic biomass. During winter, the plume of the river Scheldt is oversaturated in pCO₂ with respect to the atmosphere. During spring and summer, phytoplankton blooms occur both in the lower Scheldt estuary and in the river plume and may lead to undersaturation of pCO₂ in the easternmost area of the river plume. However, the degradation of phytoplankton induces oversaturation of pCO₂, in the westernmost area of the plume. Furthermore, the inter-annual variation of pCO₂ depends partly on the fluctuations of the discharge of the Scheldt. Our preliminary results strongly suggest that, on an annual basis, the Scheldt plume behaves as a net source of CO₂ to the atmosphere.     

Integration of vehicle routing and resource allocation in a dynamic logistics network

A shipper plans daily hub-to-hub transports within a hub and spoke network. Since a limited number of swap containers is available for transportation, two problems arise. 1. Swap containers have to be routed as pickup and delivery requests in multi-hub tours. 2. Day-by-day routing may lead to an imbalance of swap containers requiring a dynamic allocation. Neglecting interdependencies between vehicle routing and resource allocation seems inferior. An integration of the two problems overcomes this deficiency. We formulate mathematical models and propose integration approaches. The advantages of these approaches are discussed based on a computational study.