Past,present, and future of the satellite-based automatic identification system: areas of applications (2004–2016)

In 2016, the world shipping fleet grew by 3.5%. Even if the annual growth rate remains at its lowest since 2013, the global situation is still in overcapacity (UNCTAD 2016). Ninety percent of global trade, by volume, is done by sea. Monitoring this fleet helps with vessel navigation, informing to help avoid critical situations such as collisions, accidents leading to oil pollution, grounding, or ships in distress, but also because traffic management in congested areas is essential. For system wide management, in regions such as MPAs (marine protected areas), conservation is the key factor, and movements can be monitored and analyzed in order to determine illegal or suspicious activities, or in order to limit and/or divert traffic, to mitigate the risks to species subject to protection. It is among these efforts that the automatic identification system (AIS) can play a key role. Since 2004, this VHF transceiver-based reporting system, imposed by the International Maritime Organization (IMO), has shifted from a traditional vessel identification device to a tool used in a wide variety of applications. The most common uses are safety and security; these issues are quite visible in the media and may touch more people on a global scale (e.g., piracy, oil spills). Over the years, AIS has become, especially with the emergence of the satellite-based capture of the signal in 2011, a widely used tool for developing applications such as fisheries monitoring, marine conservation, air pollution forecasting and modeling, ballast water monitoring, invasive species transport, and many more. In this paper, we propose to review the peer-reviewed publications related to the uses and applications of the AIS.     

Constrained nested logit model: formulation and estimation

A model of traveller behaviour should recognise the exogenous and endogenous factors that limit the choice set of users. These factors impose constraints on the decision maker, which constraints may be considered implicitly, as soft constraints imposing thresholds on the perception of changes in attribute values, or explicitly as hard constraints. The purpose of this paper is twofold: (1) To present a constrained nested logit-type choice model to cope with hard constraints. This model is derived from the entropy-maximizing framework. (2) To describe a general framework to deal with (dynamic) non-linear utilities. This approach is based on Reproducing Kernel Hilbert Spaces. The resulting model allows the dynamic aspect and the constraints on the choice process to be represented simultaneously. A novel estimation procedure is introduced in which the utilities are viewed as the parameters of the proposed model instead of attribute weights as in the classical linear models. A discussion on over-specification of the proposed model is presented. This model is applied to a synthetic test problem and to a railway service choice problem in which users choose a service depending on the timetable, ticket price, travel time and seat availability (which imposes capacity constraints). Results show (1) the relevance of incorporating constraints into the choice models, (2) that the constrained models appear to be a better fit than the counterpart unconstrained choice models; and (3) the viability of the approach, in a real case study of railway services on the Madrid–Seville corridor (Spain).     

The taxi industry: working conditions and health of drivers,a literature review

The taxi industry plays an important role in urban transportation systems, both in economic and mobility terms. In the case of the former, it provides employment for a large number of people and circulates significant amounts of money. In the case of the latter, it is a flexible means of transportation capable of arriving at any destination. Although the way the taxi industry is organised varies across countries and even within countries, some factors are shared at varying latitudes of the globe. Working conditions, habits, health, and exposure to road crashes have been a subject of interest for researchers from various disciplines, including medicine, psychology, and economics. However, much of this research focuses on a part of the problem and is not mutually referential. A review of the literature may be useful not only to researchers of diverse disciplines but also to industry representatives and those public officials responsible for transportation, road safety and health policy. This article provides a comprehensive review of the working conditions of taxi drivers, their relationship to road risk exposure and their consequences on the health of workers. It also includes information on coping strategies and protective behaviors. The review is based on a Scopus database search. The search covered the period from 1990 to 2015. This initial search was complemented with other database searches, which yielded some additional studies. Our goal was to summarise existing knowledge, identify possible lines of research and suggest some practical recommendations. It would be important (a) to reduce the workload, establish adequate time for breaks, and provide access to healthcare, (b) to implement actions to promote and maintain healthy habits, (c) to diagnose, detect and treat indicators of occupational fatigue and stress, and (d) to develop programs that make it possible to evaluate work concerns and broaden coping strategies to foster positive changes.     

Perceptions of Threats Facing Cabo de Palos - Islas Hormigas MPA and Potential Solutions

Many marine protected areas (MPAs) face a multitude of threats to the ecosystems that they have been established to conserve. This study is based on 111 interviews conducted in 2013–2014 designed to discover the perceptions of stakeholders about the threats, the causes of the threats, and their responses to the threats, to a well-established MPA – Cabo de Palos - Islas Hormigas (CPH-MPA). This MPA was created to safeguard fisheries and the associated artisanal fishers, but over time it has become a tourism “hotspot.” Resilience theory, which incorporates ecological resilience, social resilience, and individual resilience, helps us to analyze stakeholders' responses to threats by categorizing them into passive, adaptive, and transformative responses. We found respondents identified four main threats – over-fishing, excessive scuba diving, pollution, and invasive species; attributed the threats to three main causes – ineffective management, poor environmental stewardship, and climate change; and expressed three kinds of responses – do nothing, adapt, or transform – with a preference for adaptation and (especially) transformation. The lesson of this study is that it shows how, unless drastic action is taken to curb recreational diving activities, the CPH-MPA is in danger of changing from a fishing reserve to a largely unregulated leisure diving venue, which is unlikely to fulfill the requirements of resilience; ecological, social, or individual.     

安全性对地铁系统设计的影响

论文简要介绍了风险识别、风险分析的概念以及新时代轨道交通安全面临的新问题,并探讨了功能和安全规范的解决方案.论文旨在以系统安全性为出发点,介绍地铁网络系统的实施步骤,以及如何综合考虑降低设备费用和缩短实施时间等因素.     

Eastbound or westbound ?

In terms of equal sailing distances, where is the inflexion when ships depart from ports in the Asian Continent to New York via Suez and/or Panama？
The answer is China South Port Group （Hong Kong, Shenzhen and Guangzhou）.     

Strategies for improving the mode transition in a sequential parallel turbocharged automotive diesel engine

Parallel sequential turbocharging systems are able to operate in different modes, which are defined according to the turbochargers that simultaneously boost the engine, and are controlled by means of specific valves. In order to cover the full engine operating range, a smooth transition between turbocharging operating modes must be ensured. However, important disturbances affect both boost and exhaust pressure when shifting the operation mode, thus causing non-negligible torque oscillations. This paper presents different methods for smoothing such undesirable effects during mode transition. Strategies covering optimal synchronization of the control valves, control of the valves’ position, and correction of the injected fuel during the transition are analysed. A fully instrumented passenger car engine is used for illustrating the different torque smoothing methods, and experimental results for transitions during both steady operation and engine accelerations are shown.     

Nonlinear gating control for urban road traffic network using the network fundamental diagram

This work proposes a nonlinear model predictive controller for the urban gating problem. The system model is formalized based on a research on existing models of the network fundamental diagram and the perimeter control systems. For the existing models, modifications are suggested: additional state variables are allocated to describe the queue dynamics at the network gates. Using the extended model, a nonlinear model predictive controller is designed offering a ‘non‐greedy’ policy compared with previous, ‘greedy’ gating control designs. The greedy and non‐greedy nonlinear model predictive control (NMPC) controllers are compared with a greedy linear feedback proportional‐integral‐derivative (PID) controller in different traffic situations. The proposed non‐greedy NMPC controller outperforms the other two approaches in terms of travel distance performance and queue lengths. The performance results justify the consideration of queue lengths in dynamic modeling, and the use of NMPC approach for controller design. Copyright © 2014 John Wiley & Sons, Ltd.     

A data-driven approach for origin–destination matrix construction from cellular network signalling data: a case study of Lyon region (France)

Transportation - Spatiotemporal data, and more specifically origin–destination matrices, are critical inputs to mobility studies for transportation planning and urban management purposes....     

Latent stage model for carsharing usage frequency estimation with Montréal case study

In order to predict the monthly usage frequency of members of a car-sharing scheme by analysing the gradual change of behaviour over time, a new model is proposed based on the Markov Chains model with latent stages. The model accounts for changing patterns of frequency from soon after signing up to later stages by including five latent user ‘life stages’. In applying the model to panel data from Montreal’s free-floating carsharing service the authors calculate each user’s ’lifetime’ applied to ‘system operation time’, the time period since the start of the scheme. Three-fold validation reveals effective performance of the model for both lifetime and system operation time dimensions. The model is further applied to illustrate how previous carsharing experience and the extension of the scheme to a larger area can affect usage frequency changes. We conclude that this approach is effective for usage prediction for novel transport schemes.