Mobile Routing Services for Small Towns using CloudMade API and OpenStreetMap

This research presents a practical solution for mobile routing services for small towns using open sources. Free mapping application program interfaces (API) provided by web map services, including routing services, are available to create customised map based web services combining their cartographic base data with the users own data. However, most applications focus on big cities. Location based services in small towns are generally few as many people believe there is a little demand in such areas. However, the demand of LBS applications in some small towns can be as strong as big cities, for example university towns and tourist resorts. Better location based services, especially routing services, can help strangers get familiar with the environment in a short time and lead them to places of interest. However, there are two problems to overcome for such systems. One is cost both in terms of data costs and development time. Open source data and mash-up technology could provide an answer. The other problem is the availability of suitable data of the required accuracy and detail. This is more serious as most free map services, such as Google Maps and Microsoft Bing Maps (Virtual Earth), don’t provide sufficient detailed and accurate data for routing services. One feasible and economical way is to create the map ourselves and have it updated by the public. OpenStreetMap (OSM) is a free, open and fast developing map of the world. Detailed data was collected using a GPS logging device and uploaded to OpenStreetMap. The CloudMade API was used to provide multi-mode routing services together with turn-by-turn descriptions for car users, bicycle riders, and pedestrians. This solution is relatively easy and fast to deploy. Maynooth, a small university town in County Kildare Ireland, was used as a test bed. A prototype navigation system was developed for mobile users using the Windows Mobile platform. The system demonstrates that a solution to detailed navigational services for pedestrians, cyclists and drivers can be economical and feasible for small towns

A social vulnerability-based genetic algorithm to locate-allocate transit bus stops for disaster evacuation in New Orleans, Louisiana

In the face of severe disasters, some or all of the endangered residents must be evacuated to a safe place. A portion of people, due to various reasons (e.g., no available vehicle, too old to drive), will need to take public transit buses to be evacuated. However, to optimize the operation efficiency, the location of these transit pick-up stops and the allocation of the available buses to these stops should be considered seriously by the decision-makers. In the case of a large number of alternative bus stops, it is sometimes impractical to use the exhaustive (brute-force) search to solve this kind of optimization problem because the enumeration and comparison of the effectiveness of a huge number of alternative combinations would take too much model running time. A genetic algorithm (GA) is an efficient and robust method to solve the location/allocation problem. This thesis utilizes GA to discover accurately and efficiently the optimal combination of locations of the transit bus stop for a regional evacuation of the New Orleans metropolitan area, Louisiana. When considering people’s demand for transit buses in the face of disaster evacuation, this research assumes that residents of high social vulnerability should be evacuated with high priority and those with low social vulnerability can be put into low priority. Factor analysis, specifically principal components analysis, was used to identify the social vulnerability from multiple variables input over the study area. The social vulnerability was at the census block group level and the overall social vulnerability index was used to weight the travel time between the centroid of each census block to the nearest transit pick-up location. The simulation results revealed that the pick-up locations obtained from this study can greatly improve the efficiency over the ones currently used by the New Orleans government. The new solution led to a 26,397.6 (total weighted travel time for the entire system measured in hours) fitness value, which is much better than the fitness value 62,736.3 rendered from the currently used evacuation solution

Thermal compensation of ultrasonic transmit and receive data for steel welded plates at the point of manufacture

On modern manufacturing production lines, Non-Destructive Testing (NDT) is frequently a bottleneck which could greatly be alleviated by integrating the inspection of components as they are manufactured. By moving inspection to the point of manufacture, greater economic and productivity benefits are realised in terms of reduced rework and schedule slippage, however, new technical challenges emerge. For welded components, high temperatures and the resulting thermal gradients, present challenges when performing ultrasonic inspection at the point of manufacture. The thermal gradients introduce positional misalignment due to “beam bending” effects arising from refraction as the material properties change with temperature. This paper presents for the first time, through simulation and practical experiments, a novel thermal compensation strategy to mitigate for thermal effects when performing ultrasonic inspection of welded components at the point of manufacture. To understand the thermal gradients experienced during standard Tungsten Inert Gas (TIG) welding, 3-dimensional thermal simulations were developed and experimentally-validated with an average error of 1.80%. The output from the thermal simulations in combination with material properties that vary over temperature, allowed for generalised time of flight maps to be created via the Multi-Stencils Fast Marching Method (MSFMM) and the ultrasonic data to be imaged by the Total Focusing Method (TFM). The thermal compensation strategy was initially proved on synthetically generated finite element Full Matrix Capture (FMC) datasets, and it was shown that reflector positional accuracy could be increased by ∼ 3 mm. Experimental results also showed marked improvements with reflector positional accuracy also being increased by ∼3 mm. Over both simulated and experimental datasets, the SNR was shown to be negligibly altered between uncompensated and compensated images. The results show how high-quality ultrasonic images can be generated in-process and help bring inspection closer to the point of manufacture

An Integrated Agent-Based Microsimulation Model for Hurricane Evacuation in New Orleans

Mass evacuation of urban areas due to hurricanes is a critical problem that requires extensive basic and applied research. Knowing the accurate evacuation time needed for the entire region in advance such that the evacuation order can be issued on a timely basis is crucial for the officials. Microsimulation modeling, which focuses on the characteristics of individual motorists and travel behavior, has been used widely in traffic simulation as it can lead to the most accurate result. However, because detailed driver response modeling and path processing must be incorporated, vehicle-based microscopic models have always been used only to simulate small to medium sized urban areas. Few studies have attempted to address problems associated with mass evacuations using vehicle-based microsimulation at a regional scale. This study develops an integrated two-level approach by separating the entire road network of the study area into two components, highways (i.e., interstate highways and causeways) and local roads. A vehicle-based microsimulation model was used to simulate the highway part of the road traffic, whereas the local part of the road traffic simulation utilized an agent-based model. The integrated microsimulation model was used to simulate hurricane evacuation in New Orleans. Validation results confirm that the proposed model performs well in terms of high model accuracy (i.e., close agreement between the real and simulated traffic patterns) and short model running time. Sufficient evacuation time is a premise to protect people’s life safety when an area is threatened by a deadly disaster. To decrease the network clearance time, this study also examined the effectiveness of three evacuation strategies for disaster evacuation, including a) simultaneous evacuation strategy, b) staged evacuation strategy based on spatial vulnerabilities, and c) staged evacuation strategy based on social vulnerabilities. The simulation results showed that both staged evacuation strategies can decrease the network clearance time over the simultaneous evacuation strategy. Specifically, the spatial vulnerability-based staged evacuation strategy can decrease the overall network clearance time by about four hours, while the social vulnerability-based staged evacuation strategy can decrease the network clearance time by about 2.5 hours

Identificación de los usos de suelo y análisis de viajes de residentes en Pekín utilizando los datos masivos de Mobike y puntos de interés

Màster universitari en Estudis Avançats en Arquitectura: Gestió i Valoració Urbana i ArquitectònicaEn los últimos años, los datos individuales de espacio-tiempo a gran escala y de alta calidad se han convertido en información de rápido acceso debido al acelerado desarrollo de la tecnología LBS (Location Based Service). En la actualidad el uso de esta tecnología de micro datos y minería de datos en el estudio de refinamiento urbano de la ciudad se ha convertido en la tendencia principal de los estudios urbanos. El análisis de estos datos sobre puntos de interés de las ciudades puede reflejar las actividades urbanas; ayudando a identificar usos de suelo, como los datos que describen los edificios emblemáticos de la ciudad. Por otro lado, los datos abiertos de las bicicletas compartidas reflejan el alcance de las actividades del usuario y la dinámica de la estructura espacial-temporal urbana. La combinación de datos dinámicos y estáticos ayudará a los planificadores urbanos y al público a comprender la compleja estructura espacial urbana y contribuirán a la geografía urbana y el urbanismo. En este artículo, en primer lugar, utilizamos los datos de apertura de Mobike para revelar las características y patrones de los residentes desde punto de acceso y el espacio-temporal de una manera visual después del procesamiento de datos, la coincidencia de mapas y el análisis de clústeres. Por su parte este documento también presenta un método para identificar y zonificar los usos de suelo basada en datos geográficos de fuentes públicas. La selección del área de estudio se realiza mediante datos de la red de carreteras OSM. A continuación, sobre una base ya definida del concepto de los usos del terreno, se crea un método de división de dichos suelos basado en el punto de interés. Con el análisis del mapa general de planificación urbana y el mapa de los usos de suelo, los resultados muestran que el efecto de reconocimiento es preciso, incluso los detalles identificados de los usos de suelo son más precisos que los del mapa de planificación urbana

Estrategia de enrutamiento para la maniobra del enlace a un convoy de vehículos en entornos urbanos, robusta a la incertidumbre en los tiempos de recorrido

Esta tesis propone una estrategia de enrutamiento óptima para unidades de transporte inteligente que se mueven de manera autónoma por un entorno urbano conocido. El entorno está definido por un conjunto de calles y cruces (nodos), y en su interior un grupo de unidades móviles independientes se encuentran realizando tareas específicas. Dicho entorno está rodeado por una ruta periférica por la que se mueve continuamente un convoy compuesto por un líder y un número determinado de unidades seguidoras, sin enlace mecánico entre ellos. La misión del convoy es concentrar las unidades independientes antes y después de que hayan realizado, de forma independiente, su tarea. Básicamente, el trabajo se centra en dar solución a la maniobra de enlace consistente en lograr que la unidad independiente (perseguidora), partiendo de su ubicación actual en el interior del mapa, logre alcanzar el nodo periférico idóneo para unirse al convoy. Considerando que este último está limitado a circular por la ruta externa y por tanto no tiene acceso al interior del entorno, el enlace se realizará en uno de los nodos periféricos. El convoy sigue indefinidamente su trayectoria, por lo que la maniobra se considera exitosa siempre que la unidad independiente alcance el nodo de enlace antes que el convoy. El primer objetivo es resolver la maniobra de enlace considerando conocidos los tiempos de recorrido entre los nodos del mapa. Objetivo que incluye dos fases: cálculo del nodo óptimo de enlace y de la ruta que lleve a la unidad perseguidora hasta el mismo. Se entiende por nodo óptimo de enlace aquél que garantiza un tiempo mínimo de maniobra. Además, se ha diseñado un algoritmo de enrutamiento que explora el menor número de nodos posibles lo que garantiza su eficiencia computacional y su idoneidad para su ejecución en tiempo real, de especial interés en entornos complejos. El segundo objetivo es extender estos algoritmos a un entorno donde los tiempos de recorrido entre nodos no son conocidos. Esta incertidumbre, inherente a los tiempos de recorrido de todas las unidades, es propia de escenarios de transporte reales y tiene su origen en diversas fuentes como densidad variable de tráfico, condiciones meteorológicas, momento del día, etc. Para caracterizarla se ha propuesto un modelo gaussiano, donde los tiempos de recorrido son tratados como variables aleatorias parametrizadas por su valor medio y varianza. Por otra parte, este comportamiento no determinista impide garantizar de forma absoluta el éxito seguridad la maniobra de enlace. Por ello, se introduce el parámetro de diseño "Factor de Riesgo", que limita la probabilidad de fallo de la maniobra de enlace. Este factor condiciona además el tiempo de maniobra y el número de re-planificaciones intermedias hasta llegar al nodo final. En la solución propuesta se incluye un centro remoto al que están conectadas de forma inalámbrica todas las unidades de transporte. En el centro remoto se registran los tiempos de recorrido entre nodos consecutivos proporcionados por las unidades de transporte y se estiman los parámetros estadísticos temporales entre nodos no consecutivos mediante técnicas recursivas de Programación Dinámica. Finalmente, se ha procedido a la validación experimental de la propuesta global. En una primera fase se ha recurrido a la herramienta Player/Stage para validar mediante simulación los cálculos desarrollados a partir de un mapa diseñado al efecto. Superada esta, se ha utilizado un demostrador real donde la función de unidad líder y unidad perseguidora ha sido desarrollada por robots Pioneer P3-DX