Wetlands protection: The regulatory role of the U.S. army corps of engineers

The U.S. Army Corps of Engineers administers the only nationwide regulatory program that controls development activities in U.S. waters and wetlands. This article examines the statutory authorities, jurisdictional limitations, and evolution of the current Corps regulations, which express a strong policy to protect wetlands, estuaries, and tidal waters from unnecessary dredging, filling, or other alteration. The article explains the organization and procedures of the U.S. Army Corps of Engineers and examines in detail several precedential permit cases which have developed and implemented the Corps “wetlands policy.”; The article also evaluates current and potential policies underlying the regulatory efforts of the Corps of Engineers.     

An assessment of advanced transport telematics evaluation procedures

This paper reviews and critically assesses procedures which have been adopted to evaluate Advanced Transport Telematics (ATT) projects. The importance of such a review at this juncture stems from the changing position of ATT in transport planning. ATT is no longer simply a field for experimentation, where technical feasibility and user acceptance are dominant concerns. Rather it is a potential mainstream contributor to the functioning of road transport systems. For this reason, ATT project appraisal needs to be developed to the same form, level of sophistication and consistency as the appraisal of conventional transport infrastructure investment. Based on the review set out here, we argue that appropriate methods have not yet been established which, in turn, poses a number of challenging questions, since current socio‐economic evaluation procedures are not directly suited to either measuring or evaluating many of the impacts which ATT schemes are implemented to achieve.     

Scenario construction for transport planning

This paper argues that the types of uncertainty having the most serious consequences for transport planning are not captured by existing modelling procedures, which typically rely on a limited amount of sensitivity testing of plans based on extrapolative forecasts. It recommends as an alternative scenario‐based planning, an approach which is finding increasing application in private sector policy formation. The paper summarises the origins of scenario planning and the gradual broadening in its range of application, before going on to suggest methods of scenario construction suitable for transport planning applications. It considers the arguments for and against associating probabilities with scenarios and also addresses the problems of formulating transport strategies and evaluating them within the context of a scenario‐based approach to strategy choice.     

Suitability of Decision-Theoretic Models to Public Policy Issues Concerning the Provision of Shoreline Stabilization and Hazard Management

This article examines the suitability and potential advances of decision-theoretic models from finance regarding investment decisions in shoreline stabilization projects. A set of scenarios represents the dynamics of the decision-state facing the planner and identifies factors that should be incorporated into the decision-making process. It is shown that decision models from finance can account for the risk and uncertainty inherent in shoreline stabilization projects, potentially suggest improvements and refinements to presently used cost-benefit analysis procedures, and offer new tools that can aid in decisions concerning provision of shoreline stabilization. The outcomes of these scenarios justify better planning and control of existing and future building, and that of poststorm policies. Lastly, these models allow us to explore the range of our understanding of coastal processes and interactions with shoreline stabilization projects and can identify new and useful data needed in coastal management and hazard management decisions.     

Decoupled robust control of vehicular platoon with identical controller and rigid information flow

Platoon driving has potential to significantly benefit road traffic. This study presents a decoupled robust control strategy for a vehicular platoon with identical feedback controller and rigid information topology. The node dynamics of vehicle with a lower-level controller is assumed to be covered by a multiplicative uncertainty model. The vehicular platoon control system is skillfully decomposed into an uncertain part and a diagonal system by applying linear transformation and eigenvalue decomposition on information flow graph. Then the requirements of robust stability and distance tracking error are equivalent to the H-infinity norm of decoupled sub-systems. Comparative simulations with a non-robust controller and different communication topologies are conducted to demonstrate the robust stability and distance tracking performances of the proposed method.     

Characterising and predicting car ownership using rough sets

This paper applies the relatively new knowledge discovery technique of Rough set analysis to identify the factors that influence the level of car ownership in a household. The study uses the detailed Great Britain National Travel Survey data set which contains information on both household and individual travel behaviour. The knowledge extraction is done using the theory of Rough sets and is presented in the form of easily understood if-then statements or rules which reveal how each attribute influences car ownership behaviour. These rules can then be used to predict household car ownership from information held about previously unseen households and the classification performance of the rules can be assessed. The performance of this classification task is shown to be on a par with other reported studies in this area.     

Long-memory characteristics of urban roadside air quality

Carbon monoxide is a major contributor to air pollution in urban cities, particularly at the roadside. Hourly, monthly and seasonal mean carbon monoxide concentration data are collected from a roadside air monitoring station in Hong Kong over 7-years. The station is a few metres from a major intersection surrounded by tall buildings. In particular, hourly patterns of concentrations on different days of the week are investigated. The data show that hourly carbon monoxide concentrations resemble the traffic pattern of the area and tend to be lower in the summer. Using a seasonal autoregressive integrated moving average models shows that the daily traffic cycle strongly influences concentrations. Further, it is found that urban roadside carbon monoxide monitoring data exhibits a long-memory process, suggesting that a model incorporating long memory and seasonality effects is needed simulate urban roadside air quality.     

Multi‐criteria analysis for evaluating the impacts of intelligent speed adaptation

Road safety is a policy priority due to the high casualties and costs associated with road accidents. Since speed is a major cause of road accidents, in‐vehicle speed limiters or Intelligent Speed Adaptation (ISA), seems a promising solution. ISA implementation, however, is hindered by large uncertainties, for example about the impacts of ISA, the way users might respond to ISA, and the relationship between speed and accidents. Traditional Multi‐Criteria Analysis (MCA) has limitations in handling these uncertainties. We present an MCA approach based on exploratory modeling, which uses computational experiments to explore the multiple outcomes of ISA policies (safety, emissions, throughput, and cost) across a range of future demand scenarios, functional relationships for performance criteria, and user responses to ISA. As an illustration, by testing the impacts of different ISA penetration levels on two driver groups, we show that when compliance with ISA is expected to be low, a policy aimed only at novice drivers outperforms other ISA policies on safety improvement.     

Distance and time in intermodal goods transport networks in Europe: A generic approach

This paper is about distance and time as factors of competitiveness of intermodal transport. It reviews the relevance of the factors, evaluates time models in practice, compares network distances and times in alternative bundling networks with geometrically varied layouts, and points out how these networks perform in terms of vehicle scale, frequency and door-to-door time. The analysis focuses on intermodal transport in Europe, especially intermodal rail transport, but is in search for generic conclusions. The paper does not incorporate the distance and time results in cost models, and draws conclusions for transport innovation, wherever this is possible without cost modelling. For instance, the feature vehicle scale, an important factor of transport costs, is analysed and discussed.Distance and time are important factors of competitiveness of intermodal transport. They generate (direct) vehicle costs and – via transport quality – indirect costs to the customers. Clearly direct costs/prices are the most important performance of the intermodal transport system. The relevance of quality performances is less clarified. Customers emphasise the importance of a good match between the transport and the logistic system. In this framework (time) reliability is valued high. Often transport time, arrival and departure times, and frequency have a lower priority. But such conclusions can hardy be generalised. The range of valuations reflects the heterogeneity of situations. Some lack of clarity is obviously due to overlapping definitions of different performance types.The following parts of the paper are about two central fields of network design, which have a large impact on transport costs and quality, namely the design of vehicle roundtrips (and acceleration of transport speed) and the choice of bundling type: do vehicles provide direct services or run in what we call complex bundling networks? An example is the hub-and-spoke network. The objective of complex bundling is to increase vehicle scale and/or transport frequency even if network volumes are restricted. Complex bundling requires intermediate nodes for the exchange of load units. Examples of complex bundling networks are the hub-and-spoke network or the line network.Roundtrip and bundling design are interrelated policy fields: an acceleration of the roundtrip speed, often desirable from the cost point of view, can often only be carried out customer friendly, if the transport frequency is increased. But often the flow size is not sufficient for a higher frequency. Then a change of bundling model can be an outcome.Complex bundling networks are known to have longer average distances and times, the latter also due to the presence of additional intermediate exchange nodes. However, this disadvantage is – inside the limits of maximal vehicle sizes – overruled by the advantage of a restricted number of network links. Therefore generally, complex bundling networks have shorter total vehicle distances and times. This expression of economies of scale implies lower vehicle costs per load unit.The last part of the paper presents door-to-door times of load units of complex bundling networks and compares them with unimodal road transport. The times of complex bundling networks are larger than that of networks with direct connections, but nevertheless competitive with unimodal road transport, except for short distances.     

具有无序排列管片环结构的地铁盾构隧道数字模型智能重建北大核心CSCD

运营地铁隧道的管理、健康监测及维护正逐渐趋向于数字化、智能化;但常因地铁盾构隧道管理和检测单位缺少隧道数字模型,限制了地铁隧道智能维护和管理系统的应用和发展。文章针对地铁盾构隧道中无序排列的管片环结构,提出了一种基于深度学习和机器视觉的地铁盾构隧道数字模型智能重建方法,利用检测车获取的隧道衬砌内表面高清图片,对管片特征物(螺栓孔)进行智能识别与自动分类,再根据螺栓孔群的分布特点自动推断隧道管片环的排版规律,从而结合隧道实际线路实现隧道数字模型快速重建。某地铁隧道的实例应用结果表明,该方法适用于管片无规律性错缝拼装的情况,能以100%的准确率实现地铁盾构隧道数字模型的智能重建。