Abstract

This study assessed the performance of residential buildings in public housing estates in urban areas of Ogun State Southwest Nigeria. It was based on the notion that users' satisfaction with dwelling units is a measure of the performance of residential buildings in meeting their needs and expectations. A cross sectional survey of 452 household heads in nine public housing estates was conducted in the study area. Data were obtained using structured questionnaire and observation schedule, and were subjected to descriptive statistics and factor analysis. A mean satisfaction score of 3.21 was observed, indicating that the respondents were generally satisfied with the performance of the different components of the buildings. Satisfaction levels were generally higher with privacy and sizes of living and sleeping areas than the availability of water and electricity in the buildings. The type, location and aesthetic appearance as well as size of main activity areas were the most predominant factors that determined satisfaction and indeed the performance of the buildings in meeting users' needs and expectations. The paper highlights critical areas where attention is needed in order to improve the performance of residential buildings and users' satisfaction with public housing projects in Nigeria.

Abstract

Wireless vehicular ad-hoc networks comprised solely of city taxis are investigated for their ability to deliver data across an urban environment. Openly available taxi trace datasets for Rome (Italy) and San Francisco (USA) are combined with respective building footprint and road network topology data from OpenStreetMap, to generate a realistic systems level model of a taxi V2V network. Analysis of LOS and NOLOS constraints on wireless transmission range suggests a minimum threshold of 50m is applicable to ensure LOS in over 90% of cases. Variations in taxi location sampling frequency and filtering techniques for the taxi trace datasets are also investigated. Overall vehicular network performance is computed for an all-to-one transmission scenario for both cities with varying taxi fleet size. Results suggest a non-linear relationship between increases in taxi fleet sizes and the reduction of end-to-end delay; doubling taxi fleet size (using a randomised data folding technique) reduces end-to-end delay by a factor of 0.6–0.7. However, doubling the fleet does not increase the fraction of delivered source messages, which saturates at 0.67–0.71 in most simulations. Finally it appears that taxi networks for delivering messages across urban environments are limited more by their routing than by the number of possible V2V exchanges. In a simulated one-to-all continuous V2V broadcast scenario, over 90% of the taxis within the fleet receive the source message within one hour of the original taxi passing the source node.

Abstract

Recently, ridesharing services have grown rapidly. In future, fleets of shared and pooled autonomous vehicles may transform urban mobility. In this paper, we introduce an approach to dynamically simulate these services within a full-stack transport simulation using an insertion-based algorithm. In a first test case, using a taxi data set from Berlin, the potential for shared rides is evaluated using a fleet of vehicles with a capacity between two and four ride requests. The simulation suggests that the overall vehicle kilometers traveled may be reduced by 15-20%, while travel time increases can be kept at a relatively low level of less than three minutes per person. Additionally, the simulation results suggest in which areas of the city it may be the most rewarding to offer shared services.