Analysis of Transportation Networks Subject To Natural Hazards – insights from a Colombian case

ABSTRACT: This study provides an applied framework to derive the connectivity reliability and vulnerability of inter-urban transportation systems under network disruptions. The proposed model integrates statistical reliability analysis to find the reliability and vulnerability of transportation networks. Most of the modern research in this field has focused on urban transportation networks where the primary concerns are guaranteeing predefined standards of capacity and travel time. However, at a regional and national level, especially in developing countries, the connectivity of remote populations in the case of disaster is of utmost importance. The applicability of the framework is demonstrated with a case study in the state of Antioquia, Colombia, using historical records from the 2010-2011 rainy season, an aspect that stands out and gives additional support compared to previous studies that considers simulated data from assumed distributions. The results provide significant insights to practitioners and researchers for the design and management of transportation systems and route planning strategies under this type of disruptions

A Multiclass Cumulative Prospect Theory-Based Stochastic User Equilibrium Model with Path Constraints in Degradable Transport Networks

The limited driving range and the unavailability or insufficiency of battery charging/swapping stations cause the so-called range anxiety issue for traffic assignment involving battery electric vehicle (BEV) users. In addition, expected utility theory-based stochastic user equilibrium (EUT-SUE) model generates the perfectly rational issue when the travellers make route choice decisions. To tackle these two problems, this article improves the cumulative prospect theory-based stochastic user equilibrium (CPT-SUE) model in a degradable transport network through incorporating the constraints of multiple user classes and distance limit. In this degradable network, the travellers experience stochastic travel times due to network link capacity degradations. For this improved CPT-SUE model, the equivalent variational inequality (VI) model and associated method of successive averages (MSA) based solution are provided. The improved CPT-SUE model is tested and compared with the EUT-SUE model with distance limit, with results showing that the improved CPT-SUE model can handle jointly the range anxiety issue and the perfectly rational issue

Evaluation of reliability modeling tools for advanced fault tolerant systems

The Computer Aided Reliability Estimation (CARE III) and Automated Reliability Interactice Estimation System (ARIES 82) reliability tools for application to advanced fault tolerance aerospace systems were evaluated. To determine reliability modeling requirements, the evaluation focused on the Draper Laboratories' Advanced Information Processing System (AIPS) architecture as an example architecture for fault tolerance aerospace systems. Advantages and limitations were identified for each reliability evaluation tool. The CARE III program was designed primarily for analyzing ultrareliable flight control systems. The ARIES 82 program's primary use was to support university research and teaching. Both CARE III and ARIES 82 were not suited for determining the reliability of complex nodal networks of the type used to interconnect processing sites in the AIPS architecture. It was concluded that ARIES was not suitable for modeling advanced fault tolerant systems. It was further concluded that subject to some limitations (the difficulty in modeling systems with unpowered spare modules, systems where equipment maintenance must be considered, systems where failure depends on the sequence in which faults occurred, and systems where multiple faults greater than a double near coincident faults must be considered), CARE III is best suited for evaluating the reliability of advanced tolerant systems for air transport

Networked Design Decisions in Balanced Life Cycles

Many decisions, both conscious and unconscious, have to be made during a product development process. In reaching a decision, it is essential to take the consequences of the different alternatives into consideration. To assess preconditions and consequences of decisions, an actor network can be used. An actor network is a combination of interrelated entities, representing multiple individuals and/or organizations. By adding characteristics to these actors and their relation, aspects like supply chain and life cycle issues can be addressed.\ud \ud This publication describes the basic building blocks of an actor network from a generic and abstract viewpoint. From these essential building blocks, the construction of the overall actor network is described. Examples are used from the field of content-packaging combinations, as well as aspects from life cycle assessments to illustrate the intended fundamental functionality. In the bigger picture, the use of the actor network in the context of product-packaging combinations aims at achieving lasting balance in product-packaging networks

Capacity Theorems for Quantum Multiple Access Channels: Classical-Quantum and Quantum-Quantum Capacity Regions

We consider quantum channels with two senders and one receiver. For an arbitrary such channel, we give multi-letter characterizations of two different two-dimensional capacity regions. The first region is comprised of the rates at which it is possible for one sender to send classical information, while the other sends quantum information. The second region consists of the rates at which each sender can send quantum information. For each region, we give an example of a channel for which the corresponding region has a single-letter description. One of our examples relies on a new result proved here, perhaps of independent interest, stating that the coherent information over any degradable channel is concave in the input density operator. We conclude with connections to other work and a discussion on generalizations where each user simultaneously sends classical and quantum information.Comment: 38 pages, 1 figure. Fixed typos, added new example. Submitted to IEEE Tranactions on Information Theor

On multi-objective stochastic user equilibrium

There is extensive empirical evidence that travellers consider many 'qualities' (travel time, tolls, reliability, etc.) when choosing between alternative routes. Two main approaches exist to deal with this in network assignment models: Combine all qualities into a single (linear) utility function, or solve a multi-objective problem. The former has the advantages of a unique solution and efficient algorithms; the latter, however, is more general, but leads to many solutions and is difficult to implement in larger systems. In the present paper we present three alternative approaches for combining the principles of multi-objective decision-making with a stochastic user equilibrium model based on random utility theory. The aim is to deduce a tractable, analytic method. The three methods are compared both in terms of their theoretical principles, and in terms of the implied trade-offs, illustrated through simple numerical examples

Vulnerability study of transport network geographical perspective

En la planificación y gestión de las redes de transporte no suele hacerse referencia a la vulnerabilidad de las mismas. Las consecuencias económicas, sociales y territoriales de los daños producidos sobre estas redes por acontecimientos de carácter natural o humano, ya sean espontáneos o deliberados, se extienden por el o los territorios afectados con distinto grado de incidencia. Desde una visión geográfica se presentan los casos estudiados, con un Sistema de Información Geográfica, relativos a la valoración de la vulnerabilidad de dos redes de transporte, la de carreteras de la isla de Mallorca y la de Metro de Madrid, mediante el análisis de la variación de la accesibilidad de los puntos de origen y destino de dichas redes y su impacto en el territorio que comprenden.In the planning and management of transport networks often referred to the vulnerability of the same. The economic, social and territorial damage on these occurrences networks by natural or human, whether spontaneous or deliberate spread over the territory or territories affected with varying degrees of incidence. From a geographic view the case studies are presented with a Geographic Information System relating to the assessment of the vulnerability of two networks of transport, the road of the island of Mallorca and Madrid Metro, by analyzing the variation in the accessibility of the points of origin and destination of such networks and their impact on the territory comprising

METAPHOR (version 1): Users guide

General information concerning METAPHOR, an interactive software package to facilitate performability modeling and evaluation, is presented. Example systems are studied and their performabilities are calculated. Each available METAPHOR command and array generator is described. Complete METAPHOR sessions are included