Risk evaluation in a transportation system

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Influence of Experience on Users’ Behaviour: A Day-to-Day Model for Route Choice Updating

The performance of a transportation network is the consequence of users’ choices and the interaction of these choices. Several aspects influence users’ choices. For the analyst of the transportation system, being able to forecast users’ behaviour is necessary in order to obtain a simulation close to the reality, and in order to predict the impact of hypothetical policy measures. In private car transport networks, the route choice of drivers is one of the key choice dimensions to be considered. We suppose that three main elements influence route choice: i) the subjective perception of travel times, ii) experience directly obtained on the network by the user, and iii) information acquired through information systems like Advanced Traveler Information Systems (ATIS). In particular, in the present paper we delve into the influence of information on choices, by exploring the influence of the process by which the perception of travel times is updated day-by-day due to experience obtained on the network. In our mathematical model, the users’ awareness/knowledge of actual conditions on the network changes through an evolution process. Although this kind of problem has been previously studied, a novel feature of our approach is that as a consequence of actual experience or information, users may become aware of new alternatives: hence the ‘choice set’ perceived to be available may change day-by-day, not only the perception of travel times within a given choice set. In this paper, therefore, the time-evolution of both the choice (the alternative actually chosen) and the choice set (the alternative considered) is investigated. An illustrative specification of the model is proposed, and a series of simulation experiments conducted

Residential Location, Mobility, and Travel Time: A Pilot Study in a Small-Size Italian Metropolitan Area

This research concerns the topic of Land Use and Transport Interaction (LUTI) models. In particular, the patterns between residential households' location and mobility choices are analyzed and simulated. The attributes that influence household residential location choices belong to four categories: socioeconomic and mobility attributes of households and/or of their components; land use; real-estate market; transport system. The paper presents the results of a pilot study on households' location and mobility patterns in the metropolitan area of Reggio Calabria (Southern Italy). The pilot study is divided into two stages. In the first stage, a survey allowed to collect information and identify existing patterns about residential and mobility choices of a sample of households. In the second stage, a residential location model is proposed and some preliminary calibrations are presented in a prototypal way. The pilot study could be extended and improved in terms of spatial extension and sample dimension in order to allow a complete specification-calibration-validation process of the model. The model development can support the land use-transport planning process in the Metropolitan City of Reggio Calabria

Dynamic vehicle routing in road evacuation: route design experimentation

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Novel Deterministic Detection and Estimation Algorithms for Colocated Multiple-Input Multiple-Output Radars

In this manuscript, the problem of detecting multiple targets and estimating their spatial coordinates (namely, their range and the direction of arrival of their electromagnetic echoes) in a colocated multiple-input multiple-output radar system operating in a static or slowly changing two-dimensional or three-dimensional propagation scenario is investigated. Various solutions, collectively called range & angle serial cancellation algorithms, are developed for both frequency modulated continuous wave radars and stepped frequency continuous wave radars. Moreover, specific technical problems experienced in their implementation are discussed. Finally, the accuracy achieved by these algorithms in the presence of multiple targets is assessed on the basis of both synthetically generated data and of the measurements acquired through three different multiple-input multiple-output radars and is compared with that provided by other methods based on multidimensional Fourier analysis and multiple signal classification

An Approximate Maximum Likelihood Method for the Joint Estimation of Range and Doppler of Multiple Targets in OFDM-Based Radar Systems

In this manuscript, an innovative method for the detection and the estimation of multiple targets in a radar system employing orthogonal frequency division multiplexing is illustrated. The core of this method is represented by a novel algorithm for detecting multiple superimposed two-dimensional complex tones in the presence of noise and estimating their parameters. This algorithm is based on a maximum likelihood approach and combines a single tone estimator with a serial cancellation procedure. Our numerical results lead to the conclusion that the developed method can achieve a substantially better accuracy-complexity trade-off than various related techniques in the presence of closely spaced targets

Deterministic Signal Processing Techniques for OFDM-Based Radar Sensing: An Overview

In this manuscript, we analyze the most relevant classes of deterministic signal processing methods currently available for the detection and the estimation of multiple targets in a joint communication and sensing system employing orthogonal frequency division multiplexing. Our objective is offering a fair comparison of the available technical options in terms of required computational complexity and accuracy in both range and Doppler estimation. Our numerical results, obtained in various scenarios, evidence that distinct algorithms can achieve a substantially different accuracy-complexity trade-off

Safety of users in road evacuation: simulation of a user refuge area

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SYNTHESIS, INTRACELLULAR DISTRIBUTION, AND SECRETION OF IMMUNOGLOBULIN AND H-2 ANTIGEN IN MURINE SPLENOCYTES

A/J spleen cells were labeled with [3H]leucine and at intervals thereafter were homogenized and separated into microsomes and cell sap. Ig and H-2 antigens were assayed in the cell fractions and cell supernatants using immunoprecipitation. In addition, cells labeled by enzymatic radioiodination were incubated to determine the rates of release of Ig and H-2 antigens from the surface. The results indicate that the majority of Ig and H-2 antigens remain membrane bound throughout their intracellular life. In contrast to Ig, H-2 antigens are neither secreted nor shed from the cell surface. It is suggested that Ig is a peripheral protein of the cell membrane, whereas H-2 antigens are integral ones. The release of Ig on a fragment of plasma membrane could occur at fixed cell surface areas that contain no H-2 antigens or from which they have migrated before release

A system of models for signal setting design of a signalized road network in evacuation conditions

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