Developing management guidelines for oil and gas activities: The louisiana experience

Abstract

Preliminary management guidelines have been derived for oil and gas activities in coastal Louisiana. Derivation of these guidelines was done in terms of the natural function of the coastal ecosystem; this means that all economic activities should be designed to complement natural function as much as possible. The guidelines range in scope from very specific, almost performance standards, to very general admonitions. For example, we have suggested that spoil banks, produced as a result of dredging, should not be higher than the height of the daily tide or roughly 15 cm in coastal Louisiana, and at the other extreme, we have suggested that all dredging should be done with great care during wildlife migrations, spawning, and nesting times.     

Autonomous vehicles: who will use them,and will they share?

ABSTRACT

The advent of road transport automation is suggested to be one of four key technological transitions that could amount to a major transformation in mobility practices. Specifically, fully Automated Vehicles (AVs) might replace the current private car owner user model with fleets of on-demand synchronously-shared automated taxis. However, significant barriers to this vision becoming the norm remain. This paper examines two critical user-acceptance aspects of the transition: willingness to adopt AVs, and willingness to share an AV with others, particularly strangers. Our novel survey (n?=?899) included a choice experiment featuring four future full automation transport services (private, synchronously/asynchronously shared, and public). Cluster analysis examined respondents' preferences and their demographic and psycho-social characteristics. We uncover significant uncertainty about willingness to adopt automation and sharing, and important differences between clusters within our sample. For example, under 50% of participants report willingness to use an AV over their normal mode, or would prefer an automated option to a current human-driven option. Our findings raise critical questions for policymakers and transport authorities. Not least, how can AV technologies help realise the environmental and social benefits of widespread vehicle sharing in a context of a travelling public that still prefers its privacy on-the-move?     

Road transport and climate change: Stepping off the greenhouse gas

Transport is Australia’s third largest and second fastest growing source of greenhouse gas (GHG) emissions. The road transport sector makes up 88% of total transport emissions and the projected emissions increase from 1990 to 2020 is 64%. Achieving prospective emission reduction targets will pose major challenges for the road transport sector. This paper investigates two targets for reducing Australian road transport greenhouse gas emissions, and what they might mean for the sector: emissions in 2020 being 20% below 2000 levels; and emissions in 2050 being 80% below 2000 levels. Six ways in which emissions might be reduced to achieve these targets are considered. The analysis suggests that major behavioural and technological changes will be required to deliver significant emission reductions, with very substantial reductions in vehicle emission intensity being absolutely vital to making major inroads in road transport GHG emissions.     

Impact of information technology on the methods and working systems of the freight forwarding industry

Freight forwarding fulfils the role of information processor. The past decade has seen considerable change in the information industry. Combine these two facts and we can begin to explain why freight forwarders have a vested interest in using computer based information systems to their full. Many organizations have tried, some with considerable success, but in others a lack of real commitment and professionalism has cost considerable sums. In this paper the background to the industry is reviewed together with an analysis of the reasons for the poor implementation of successful systems.     

TBM及其在中国的应用(3)

3.6先进的掘进及支护系统 3.6.1其他先进的掘进技术 除了上述的各种主要的先进TBM技术外,还有下列几种先进的地下掘进技术:     

A combined land use-transportation model when zonal travel demand is endogenously determined

A combined transportation-land use model is proposed in this paper. Unlike other existing urban land use and transportation planning models in which a “fixed demand” for services is assumed to be known at the zonal level of an urban area, zonal travel demand is endogenously determined together with link congestion costs, optimal amounts of production and resulting efficient densities of land uses, once the transportation network is given. Some characteristics of alternative solutions are demonstrated. The proposed model represents progress over previous efforts in combining land use-transportation problems since the travel choice as to origin, destination and routes as well as amounts of goods to be produced at the optimal density of land uses are integrated into a consistent mathematical programming framework.     

Investigation of active torsion bar actuator configurations to reduce vehicle body roll

The increasing popularity of sport utility/light-duty vehicles has prompted the investigation of active roll management systems to reduce vehicle body roll. To minimize vehicle body roll and improve passenger comfort, one emerging solution is an active torsion bar control system. The validation of automotive safety systems requires analytical evaluation and laboratory testing prior to implementation on an actual vehicle. In this article, a computer simulation tool and accompanying hardware-in-the-loop test environment are presented for active torsion bar systems to study component configurations and performance limits. The numerical simulation illustrates that the hydraulic cylinder extension limits the active torsion system's ability to provide body roll angle reduction under various driving conditions. To compare the control system's time constant and body roll minimization capabilities for different hydraulic valve assemblies and equivalent hose lengths, an experimental test stand was created. For a typical hydraulic pressure and hose diameter, the equivalent hose length was not a key design variable that impacted the system response time. However, the servo-valve offered a quicker transient response and smoother steady-state behavior than the solenoid poppet actuators that may increase occupant safety and comfort.     

Recent advances in automotive technology and the cost-effectiveness of fuel economy improvement

The potential for improving the fuel economy of conventional, gasoline-powered automobiles through optimized application of recent technology advances is analyzed. Results are presented at three levels of technical certainty, ranging from technologies already in use to technologies facing technical constraints (such as emissions control problems) which might inhibit widespread use. A fleet-aggregate, engineering-economic analysis is used to estimate a range of U.S. new car fleet average fuel economy levels achievable given roughly 10 years of lead time. Technology cost estimates are compared to fuel savings in order to determine likely cost-effective levels of fuel economy, which are found to range from 39 miles per gallon to 51 miles per gallon depending on technology certainty level. The corresponding estimated increases in average new car price range from $540 to $790 (1993$). Estimated fuel savings payback times average less than 3 years and the cost of conserved energy averages $0.50 per gallon, indicating that these levels of fuel economy improvement are cost-effective over a vehicle lifetime. A vehicle stock turnover model is used to project the reductions in gasoline consumption and associated emissions that would follow if the estimated fuel economy levels are achieved. Potential trade-offs regarding vehicle performance, safety, and emissions are also discussed.