Factors that affect the ability of people with disabilities to walk or wheel to destinations in their community: a scoping review

ABSTRACT

It is essential that the pedestrian environment accommodates all users so they can participate in everything the community has to offer. However, people with disabilities (PWDs) often find it difficult to navigate this environment because of physical and social accessibility factors. While we know a great deal about which factors act as barriers and facilitators to mobility, we do not know enough about how they influence navigation (i.e. planning a route, en route decisions, and route learning) or how they can be improved. A scoping review was conducted to identify these factors, assess their implications, and suggest future directions. In total, 3394 studies were found and screened, 163 full-text articles were reviewed, and 37 articles met the inclusion criteria for the final review. These studies focused on those with visual impairments, navigating crosswalks, and the cognitive elements of navigation. Future research is needed that includes more types of disabilities, considers the navigational process from planning to arrival, and evaluates interventions.     

雨水感应式雨刷系统最新技术

现代汽车中配备了许多自动化系统。它们可以做许多原本需要驾驶员自己去做的事情，雨水感应式自动雨刷系统便是其中一个典型代表。雨水感应式自动雨刷系统看起来好像并没有什么特别之处，但其背后却包含了工程师们大量的心血。融入了许多技术创新和突破。     

Errors in dynamical fields inferred from oceanographic cruise data: Part I. The impact of observation errors and the sampling distribution

Diagnostic studies of ocean dynamics based on the analysis of oceanographic cruise data are usually quite sensitive to observation errors, to the station distribution and to the synopticity of the sampling. Here we present an error analysis of the first two sources. The third one is evaluated in Part II of this work (J. Mar. Sys. (2005), this issue). For observed variables and those linearly related to them, we use the Optimal Statistical Interpolation (OI) formulation. For variables which are not linearly related to observed variables (e.g., the vertical velocity), we carry out numerical experiments in a consistent way with OI statistics. Best results are obtained when some kind of scale selection or spatial filtering is applied in order to suppress small scales that cannot be properly resolved by the station distribution.The formulation is first applied to a high resolution (SeaSoar) sampling aimed to the recovery of mesoscale features in a region of large spatial variability (noise-to-signal fraction of the order of 0.002). Fractional errors (rms error divided by the standard deviation of the field) are estimated in about 2% for dynamic height and between 4% and 20% for geostrophic vorticity and vertical velocity. For observed variables, observation errors and sampling limitations are shown to contribute in similar amounts to total errors. For derived variables, sampling errors are by far the dominant contribution. For less dense samplings (e.g., equally spaced CTD stations), fractional errors are about 6% for dynamic height and between 15% and 30% for geostrophic vorticity and vertical velocity. For this sampling strategy, errors of all variables are mostly associated with sampling limitations.     

咫尺之遥的未来汽车技术

尽管屡见报端的新闻确实使人们看到汽车业发生了格局混乱的现象,但是在汽车设计研发方面的技术创新却从未间断过。有很多技术创新的成果你已经能在最新的车型上看到了,不仅如此,未来还将有更多的新技术成果源源呈现在你的面前。     

Effectiveness of using variable message signs to disseminate dynamic traffic information: Evidence from field trails in European cities

Variable message signs (VMS) can provide up‐to‐date traffic information and guidance to drivers through electronic signs at the roadside. The paper draws together the results from VMS field trials conducted in nine cities as part of European Union‐sponsored research projects carried out between 1994 and 1999. The projects followed common guidelines in carrying out field trial evaluations, which has enabled generalized findings to be made on the impacts of the different VMS applications. The main emphasis in the paper is on drivers' reactions to VMS and the impacts of VMS on road network efficiency. Results are reported for four different types of traffic information. For incident messages, it is not only the severity of the problem reported that influences the level of diversions, but also other factors such as the specific location mentioned and the availability of viable alternative routes to avoid the problem location. For route guidance information, it is demonstrated that substantial diversions occur when the route advice differs from that given normally. For continuous information describing the traffic state on a major route, information increases the use of the major route and reduces use of alternative routes if there are no traffic problems reported on the major route. Travel time information was well regarded by drivers and found to be effective in inducing route changes. In general, the deployments of VMS to inform drivers of traffic conditions have proved successful in terms of improving network travel times and reducing environmental impacts. Whilst such changes have been relatively small, driver perception of the benefits is much higher. This is potentially very significant in terms of the role that VMS can play in the development of integrated transport strategies, as the provision of information may encourage greater acceptance of a range of demand management measures.     

Errors in dynamical fields inferred from oceanographic cruise data: Part II. The impact of the lack of synopticity

Diagnostic studies of ocean dynamics based on the analysis of oceanographic cruise data are usually quite sensitive to observation errors, to the station distribution and to the synopticity of the sampling. The first two sources have been evaluated in the Part I of this work. Here we evaluate synopticity errors for different sampling strategies applied to simulated unstable baroclinic waves. As suggested in previous studies, downstream and upstream cross-front samplings produce larger errors than along-front samplings. In our particular case study, the along-front sampling results in fractional errors (rms error divided by the standard deviation of the field) of about 15% for dynamic height and more than 50% for relative vorticity and vertical velocity. These values are significantly higher than those obtained in Part I for typical observation errors and sampling limitations (about 6% for dynamic height and between 15 and 30% for geostrophic vorticity and vertical velocity).We also propose and test two methods aimed at reducing the impact of the lack of synopticity. The first one corrects the observations using the quasi-geostrophic tendency equation. The second method combines the relocation of stations (based on a system velocity) and the correction of observations (through the estimation of a growth rate). For the fields simulated in this work, the second method gives better results than the first, being able to eliminate practically all synopticity errors in the case of the along-front sampling. In practice, the error reduction is likely to be less effective, since actual fields cannot be expected to have a system velocity as homogeneous as for the single-mode waves simulated in this work.     

A splitting rate model of traffic re-routeing and traffic control

The paper presents an idealised dynamical model of day-to-day or within-day re-routeing using splitting rates at nodes, or node-exit flows, rather than route-flows. It is shown that under certain conditions the dynamical model gives rise to a sequence of link flow vectors which converges to a set of approximate Wardrop equilibria. A special dynamical signal green-time re-allocation model is added; the combination is also shown (in outline) to converge to the set of approximate consistent equilibria under certain conditions. Finally the paper uses model network results to illustrate a method of designing fixed time signal timings to meet different scenarios.     

On the Destabilizing Effect of Liquids in Various Vehicles* (part 1)

The unrestrained free surface of a liquid has an alarming propensity to undergo large excursions for even very small motions of the container. This fact may endanger the stability, as well as the riding and maneuvering quality of the vehicle considerably. It is particularly true for fuel- or cargo tanks of automotive vehicles, railroad tank cars, for fuel tanks of large ships and tankers, for which violent sea conditions at times result in fairly large amplitudes of pitching, heaving and rolling, as well as for airplanes and spacevehicles flying through atmospheric disturbances. The response of liquids contained in cargo- or fuel tanks is therefore of quite some concern, especially in those cases where the sloshing liquid masses occupy a large amount of the total mass of the vehicle.

For this reason the theory of liquid motion with a free surface is presented for containers of various geometries. Forces and moments of the liquid exerted upon the vehicle are presented and a simple mechanical model for the representation of the liquid motion is derived. Methods for the reduction of the destabilizing effect of the liquid motion, such as baffles, cross walls and surface coverings are presented and shall exhibit their effectiveness. In addition the interaction of the liquid motion with the elastic structure of the container, as well as the interaction with a controlling system of the vehicle shall be demonstrated. Stability boundaries, design criteria and dynamic responses to disturbances shall be presented for a particular case.     

汽车电子器件的保护装置

传统的保险丝已经不能为敏感的电子元器件提供充分的安全保护了，因此许多更复杂而有效的保护措施就应运而生。作者将为你介绍几种目前较为成熟的汽车电子器件的瞬时高电压抑制方法，以及对过流和数据损坏的保护措施。[编者按]