Filipe Moura

Bridging the gap in planning indoor pedestrian facilities

Abstract Pedestrians are currently attracting the interest of various researchers and practitioners, particularly urban and transport planners. Analysis of the pedestrian behavior, environment and modeling has been carried out in diverse instances in the context of pedestrian planning. This paper seeks to identify the content of each of these three research areas and designate the linkages that connect their interests providing insights into planning indoor pedestrian facilities. To achieve this objective, a review of the literature on pedestrians walking indoors and indoor pedestrian environments was conducted. Understanding pedestrian behavior is fundamental in the pedestrian planning process. Principles of decision-making, cognition, wayfinding and flows were studied. When analyzing the pedestrian environment, Space Syntax and wayfinding analysis were found to be established methods that are an integral part of this field. Finally, the majority of the existing modeling approaches were identified. It was found that despite the dynamic evolution of each area, the integration of different research perspectives is weak. The paper concluded with the proposal of a mindmap which brings together all the concepts found in the literature and which should be explored for a more comprehensive planning of indoor pedestrian facilities.

Type II and heterotic one loop string effective actions in four dimensions

We analyze the reduction to four dimensions of the 4 terms which are part of the ten-dimensional string effective actions, both at tree level and one loop. We show that there are two independent combinations of 4 present, at one loop, in the type IIA four dimensional effective action, which means they both have their origin in M-theory. The d = 4 heterotic effective action also has such terms. This contradicts the common belief that there is only one 4 term in four-dimensional supergravity theories, given by the square of the Bel-Robinson tensor. In pure = 1 supergravity this new 4 combination cannot be directly supersymmetrized, but we show that, when coupled to a scalar chiral multiplet (violating the U(1) R-symmetry), it emerges in the action after elimination of the auxiliary fields.

The Incorporation of Passenger Connectivity and Intermodal Considerations in Intercity Transport Planning

Abstract Congested road and air networks, coupled with the idea that transport systems should be balanced, have spawned the field of intercity intermodal passenger transport which is based on travel across connected networks that is as seamless as possible. There is a very large number of attributes that affect the objective and subjective quality of travel. Intercity public transport planning therefore requires an excellent understanding of connections between different services and how the quality of these connections affects passengers, operators and the society at large. This article reviews the vast literature over the last 20 years from Europe, North America and Asia that is related to intercity travel, the connectivity of transport and cooperation between different modes of transport and presents a simple yet powerful way to perceive connected transport systems. The article then reviews planning practice at a variety of states worldwide, and suggests a set of focus areas of research or gaps that once filled, the authors expect, will allow further development of connected intercity passenger travel.

Tensorial perturbations and stability of spherically symmetric d-dimensional black holes in string theory

We compute the tensorial perturbations to a general spherically symmetric metric in d di- mensions with string-theoretical corrections quadratic in the Riemann tensor, from which we derive their respective potential. We use this result to study the stability of corresponding black hole solutions under such perturbations.

Scattering of spherically symmetric d-dimensional α′-corrected black holes in string theory

A bstractWe study scattering of minimally coupled massless scalar fields by non-extremal spherically symmetric black holes in d dimensions with string-theoretical α′ corrections. We then obtain a formula for the low frequency absorption cross section for every black hole of this kind, which we apply to known black hole solutions. We compare the α′ corrections for the absorption cross section with those for the black hole entropy, obtained through Wald’s formula, in each case concluding that these corrections are different. We find a general covariant formula for the absorption cross section including α′ corrections, in terms of the horizon area and temperature.

String-corrected dilatonic black holes in d dimensions

We solve the dilaton field equation in the background of a spherically symmetric black hole in bosonic or heterotic string theory with curvature-squared corrections in arbitrary d spacetime dimensions. We then apply this result to obtain a spherically symmetric black hole solution with dilatonic charge and curvature-squared corrections in bosonic or heterotic string theory compactified on a torus. For this black hole, we obtain its free energy, entropy, temperature, specific heat, and mass.

Optimizing High-Speed Rail and Air Transport Intermodal Passenger Network Design

How does one quantitatively analyze intermodal passenger systems? Can high-speed rail links reduce costs to airline services? A method for analyzing transportation networks that involve more than one mode is presented. With intermodal costs considered in detail from both the operator and the traveler aspects (including time costs and service benefits and negative costs), optimal network designs that reduce overall costs for both stakeholders are created. As a case study, the potential impact on optimization of transportation network design for air and high-speed rail travel around the Iberian Peninsula in southwestern Europe is examined. Key aspects of the model design and assumptions, including the sparse and contrasting intermodal valuations used, weighting of the cost components, and the cost to implement inter modality are evaluated. The optimization procedure, using a linear Boolean mathematical program, shows that the benefits of intermodality are best captured when a more holistic intermodal product is offered, and that high-speed rail becomes progressively less competitive as traveler costs rise and there is a discernible shortage of traveler valuations of intermodal service attributes.

A Conceptual Framework for Understanding Latent Demand: Accounting for Unrealized Activities and Travel

Historically, latent demand—the activities and travel that are desired but unrealized because of constraints—has been examined from the standpoint of understanding the effects of proposed capacity or service improvements on travel demand. Drawing on work from a variety of theoretical perspectives, this paper presents a broader conceptual view of latent demand that provides a useful framework for researching and understanding these unmet needs. This view is important from an equity standpoint, as it provides insights into questions of transport disadvantage, social exclusion, and poverty. The framework presented here is theoretical in nature and untested empirically. This paper aims to promote discussion and ultimately a more developed theory that can inform transportation planning and forecasting. A better definition and quantification of latent (or induced) demand can aid transportation planners in better predicting the effects of future transportation investments and other social, economic, and technological changes.

Typologies of Urban Cyclists

Following global guidelines, several cities are investing in urban cycling. Cities are in different stages of cycling development and have adopted different approaches and packages of policies that are likely to be most effective at each stage. Urban cycling plans include investment in infrastructure, promotion, and education supporting the adoption of active modes for urban mobility. Some investments aim to meet current cyclists’ needs and others those of potential bicycle adopters. With respect to urban cyclists, several studies propose typologies, usually related to frequency, trip purpose, or motivation. This paper compares a set of cyclist typologies and the corresponding categorization methods and reviews 20 studies that considered different cyclists’ profiles. Most studies relied on expert judgment approaches or rule-based decisions; five considered multivariate analysis techniques for clustering groups, on the basis of data from surveys. Despite the variety of group categorizations, commonalities were found in most cases and divided cyclists into three main types: current cyclists (typically more proficient riders), potential cyclists (willing but not convinced), and noncyclists (unaware of or unwilling to shift to cycling). Dividing the population of potential cyclists into different typologies can better inform the different stages of planning for cycling infrastructure development by targeting more accurately the needs and requirements of different types of users. This is a key element in the management of a cycling network and cycling infrastructure, which are intended to be built on the basis of effective solutions and decisions to achieve desirable bicycle modal shares of regular trips.

Measuring uncertainty in discrete choice travel demand forecasting models

ABSTRACT In transportation projects, uncertainty related to the difference between forecast and actual demand is of major interest for the decision-maker, as it can have a substantial influence on the viability of a project. This paper identifies and quantifies discrete choice model uncertainty, which is present in the model parameters and attributes, and determines its impact on risk taking for decision-making applied to a case study of the High-Speed Rail project in Portugal. The methodology includes bootstrapping for the parameter variation, a postulated triangular distribution for the mode-specific input and a probabilistic graphical model for the socio-economic input variation. In comparison to point estimates, the findings for mode shift results in a wider swing in the system, which constitutes valuable information for decision-makers. The methodology, findings and conclusions presented in this study can be generalized to projects involving similar models.