Socioeconomic and usage characteristics of transportation network company (TNC) riders

Transportation - The widespread adoption of smartphones followed by an emergence of transportation network companies (TNC) have influenced the way individuals travel. The authors use the 2017...     

Service design for public transportation to address the issue of females’ fear of crime

Transportation - In conjunction with their gender, how does the current design of public transport services affect female passengers’ feelings of safety and fear when using the service? This...     

S^2 BHCA Multiple AUVs cooperation oriented control architecture

Oceanographic survey, or other similar applications should be the applications of multiple AUVs. In this paper, the skill ＆ simulation based hybrid control architecture （S^2BHCA） as the controller＇s design reference was proposed. It is a multi-robot cooperation oriented intelligent control architecture based on hybrid ideas. The S^2BHCA attempts to incorporate the virtues of the reactive controller and of the deliberative controller by introducing the concept of the ＂skill＂. The additional online task simulation ability for cooperation is supported, too. As an application, a multiple AUV control system was developed with three ＂skills＂ for the MCM mission including two different cooperative tasks. The simulation and the sea trials show that simple task expression, fast reaction and better cooperation support can be achieved by realizing the AUV controller based on the S^2BHCA.     

冲绳城市单轨运输系统

简要介绍了冲绳城市单轨运输系统的设施和车辆概况.     

Fluxes of dissolved inorganic carbon in three estuarine systems of the Cantabrian Sea (north of Spain)

The diffusive and in situ fluxes of dissolved inorganic carbon (DIC) and total alkalinity (TA) have been measured and an estimation has been made of the water–atmosphere fluxes of CO₂ in three estuarine systems of the Cantabrian Sea during the spring of 1998. Each of these systems undergoes a different anthropogenic influence. The diffusive fluxes of dissolved inorganic carbon and total alkalinity obtained present values ranging between 0.54–2.65 and 0.0–2.4 mmol m⁻² day⁻¹, respectively. These ranges are in agreement with those of other coastal systems. The in situ fluxes are high and extremely variable (35–284 mmol TA m⁻² day⁻¹, 43–554 mmol DIC m⁻² day⁻¹ and 22–261 mmol dissolved oxygen (DO) m⁻² day⁻¹), because the systems studied are very heterogeneous. The values of the ratio of the in situ fluxes of TA and DIC show on average that the rate of dissolution of CaCO₃ is 0.37 times that of organic carbon oxidation. Equally, the interval of variation of the relationship between the benthic fluxes of inorganic carbon and oxygen (F_DIC/F_DO) is very wide (0.3–13.9), which demonstrates the different contributions made by the processes of aerobic and anaerobic degradation of the organic matter, as well as by the dissolution–precipitation of CaCO₃. The water–atmosphere fluxes of CO₂ present a clear dependence on the salinity. The brackish water of these systems (salinity<20), where maximum fluxes of 989 mmol m⁻² day⁻¹ have been estimated, act as a source of CO₂ to the atmosphere. The more saline zones of the estuary (salinity>30) act as a sink of CO₂, with fluxes between −5 and −10 mmol m⁻² day⁻¹.     

Shape Optimization of Elliptical Road Containers Due to Liquid Load in Steady-State Turning

A numerical analysis of liquid load in elliptical road containers undergoing a steady-state turning manoeuvre is presented for containers of unrestricted size and for containers of fixed capacity. The liquid load is expressed in terms of the horizontal and vertical forces and the overturning moment created by these forces around the middle bottom point of the container. The moment is obtained by integrating the liquid free-surface equation and using numerical calculation of the resulting expressions. An optimization study with an objective to minimize the peak overturning moment is performed on containers of fixed capacity to identify the optimal height/width ratio of the container. The results of this investigation being of a general nature, i.e. with no restriction for an application, are particularly intended for road tankers under a steady turning manoeuvre, where they can be applied with high degree of accuracy.     

Young drivers and graduated licensing: The Ontario case

Despite improvements in road safety over the past several decades, accident rates remain high for young drivers. One accident countermeasure that is expected to improve the safety record of this group is graduated licensing. The philosophy behind this licensing system is that novice drivers, of whom the majority are young, should be restricted to relatively safe driving environments during the initial learning period. Graduated licensing was implemented in the Province of Ontario, Canada in 1994. The objective of this study is to estimate the potential benefits and costs for young drivers associated with two components of the Ontario graduated licensing package: the late-night driving curfew and the high-speed roadway restrictions. Based on accident and travel data for the year 1988, accident-involvement rates per kilometre driven were calculated for different driver groups for various combinations of time of day and roadway speed limit. These rates were then applied to the expected mobility profiles of young drivers affected by graduated licensing. The results of the study support the late-night curfew and suggest that this component of the licensing package should reduce total accident involvements for the affected group by up to 10 percent and fatal accident involvements by up to 24 percent, while reducing their total driving by only four percent. By contrast, the empirical evidence suggest that the high-speed roadway restrictions are likely to increase accident involvements, and thus it is strongly recommended that this component of Ontario's graduated licensing package be changed.     

Transit assignment under crowded conditions

This paper presents a transit assignment algorithm for crowded networks. Both congestion in vehicles and queuing at stations are explicitly taken into account in predicting passenger flows for a fixed pattern of origin-destination trip demands. The overflow effects due to insufficient capacity of transit lines are considered to be concentrated at transit stations, while the in-vehicle congestion effects (or discomforts) are considered to be dependent on in-vehicle passenger volume. Overflow delay at a transit station is dependent on the number of excess passengers required to wait for the next transit car. We use a logit model to determine the split between passengers that chose to wait for the next transit car and passengers that chose to board on the alternative transit lines. The proposed algorithm predicts how passenger will choose their optimal routes under both queuing and crowded conditions.     

Mixed analysis of shell and solid elements using the overlaying mesh method

 This article presents a mixed method of analyzing shell elements and solid elements using the overlaying mesh method. In the structural design of a ship's hull, the shell elements are used for the global model. However, the solid elements are necessary to analyze the stress concentration zones or the vicinity of a crack. In such cases, the models are analyzed using zooming analysis, in which the results of a global model analysis are transferred to a local model analysis by imposing boundary conditions. This method is more advantageous than zooming analysis in terms of the accuracy of the solution and the modeling flexibility. Some examples of a plate model with a cracked surface or with a projection are shown in order to demonstrate the effectiveness of the method. Received: August 6, 2002 / Accepted: November 25, 2002 Address correspondence to: S. Nakasumi (sumi@nasl.t.u-tokyo.ac.jp) Updated from the Japanese original, which won the 2002 SNAJ prize (J Soc Nav Archit Jpn 2001;189:219–224; and 190:655–662)     

A study of passenger discomfort measures at the Hong Kong mass transit railway system

This note investigates the important attributes relating to the crowding effects at the Mass Transit Railway (MTR) stations in Hong Kong. Data was collected at two sets of three MTR stations to study the responses of the passengers due to the discomfort at crowded vehicles and platforms. Stated preference surveys were used to study the effects of passenger discomfort measures.