Infrastructure Engineering - Research Publications
Permanent URI for this collection
Search Results
1 - 10 of 10
-
ItemAnalysis of an Ad-hoc Platoon Formation and Dissolution Strategy on a Multi-lane Highway.(University of Auckland, 2019-01-01)Vehicle platooning has become popular in the recent Intelligent Transportation System (ITS) research. The literature typically assumes a planned formation and dissolution of platoons, mostly at source and destination. In contrast, this research considers platoons that can be formed on the fly. We investigate a greedy type of platoon formation with no particular order of destinations of the platoon members. This greedy formation allows a quick formation of the platoon but imposes an overhead of platoon rebuild cost when platoon members leave. The question arises whether this greedy formation and dissolution of platoons can preserve the original fuel benefit of platooning. To investigate this question, this research implements such a strategy and provides a generic guideline for fuel-efficient ad-hoc platooning
-
ItemModelling Uncertainty of Single Image Indoor Localisation Using a 3D Model and Deep Learning(ISPRS, 2019-05-29)Many current indoor localisation approaches need an initial location at the beginning of localisation. The existing visual approaches to indoor localisation perform a 3D reconstruction of the indoor spaces beforehand, for determining this initial location, which is challenging for large indoor spaces. In this research, we present a visual approach for indoor localisation that is eliminating the requirement of any image-based reconstruction of indoor spaces by using a 3D model. A deep Bayesian convolutional neural network is fine-tuned with synthetic images generated from a 3D model to estimate the camera pose of real images. The uncertainty of the estimated camera poses is modelled by sampling the outputs of the Bayesian network fine-tuned with synthetic images. The results of the experiments indicate that a localisation accuracy of 2 metres can be achieved using the proposed approach.
-
ItemInitial Analysis of Simple Where-Questions and Human-Generated Answers(LIPIcs, 2019)Geographic questions are among the most frequently asked questions in Web search and question answering systems. While currently responses to the questions are machine-generated by document/snippet retrieval, in the future these responses will need to become more similar to answers provided by humans. Here, we have analyzed human answering behavior as response to simple where questions (i.e., where questions formulated only with one toponym) in terms of type, scale, and prominence of the places referred to. We have used the largest available machine comprehension dataset, MS-MARCO v2.1. This study uses an automatic approach for extraction, encoding and analysis of the questions and answers. Here, the distribution analysis are used to describe the relation between questions and their answers. The results of this study can inform the design of automatic question answering systems for generating useful responses to where questions.
-
ItemThe grass is greener on the other side: understanding the effects of green spaces on Twitter user sentiments(ACM Press, 2018)Green spaces are believed to improve the well-being of users in urban areas. While there are urban research exploring the emotional benefits of green spaces, these works are based on user surveys and case studies, which are typically small in scale, intrusive, time-intensive and costly. In contrast to earlier works, we utilize a non-intrusive methodology to understand green space effects at large-scale and in greater detail, via digital traces left by Twitter users. Using this methodology, we perform an empirical study on the effects of green spaces on user sentiments and emotions in Melbourne, Australia and our main findings are: (i) tweets in green spaces evoke more positive and less negative emotions, compared to those in urban areas; (ii) each season affects various emotion types differently; (iii) there are interesting changes in sentiments based on the hour, day and month that a tweet was posted; and (iv) negative sentiments are typically associated with large transport infrastructures such as train interchanges, major road junctions and railway tracks. The novelty of our study is the combination of psychological theory, alongside data collection and analysis techniques on a large-scale Twitter dataset, which overcomes the limitations of traditional methods in urban research.
-
ItemActivity-based Mobility Profiling(ACM Press, 2018)Several studies have shown that the spatio-temporal mobility traces of human movements can be used to identify an individual. However, this work presents a novel framework for activity-based mobility profiling of individuals using only the temporal information. The proposed framework is conducive to model individuals' activity patterns in temporal scale, and quantifies the uniqueness measures based on certain temporal features of the activity sequence.
-
ItemInternational Workshop on Social Space and Geographic Space(The University of Melbourne, 2007)Social agents are embedded in both social structures and in geographical space. The combination of social and geographic space has often been neglected. With few exceptions, social network theory ignores geographic space, and artificial intelligence studies often assume local societies without sophisticated conceptualisations of social networks. Yet the multiple embeddedness of actors in both physical and social space has important implications for understanding social behaviour. In many related research areas, there is a growing recognition that associations between social structure and geographical nearness may affect social systems and social behaviours. Research on the associations between social and geographic space occurs in disconnected scientific communities, including human geography, social network theory, and geographic agent-based simulation. The International Workshop on Social Space and Geographic Space aims to bring the social and the spatial disciplines together, to discover joint foundations in social and geographical theory, and to integrate approaches for modelling spatial context and social behaviour. Seven papers were selected for presentation at the workshop, out of twelve papers submitted. The chairs would like to acknowledge the support from the ARC Research Network on Spatially Enabled Social Sciences. Special thanks go to Lin-Jie Guan for typesetting these proceedings.
-
ItemConsiderations for Efficient Communication of Route Directions( 2006)We can observe that people familiar with an environment give route directions of varying granularity to other locals. Such route directions are typically shorter than the turn based directions of current navigation services, and contain only references of high relevance to the wayfinder. Studying these route directions of varying granularity reveals that they are intended to be memorized, a property that requires a low cognitive workload of the wayfinder during their usage. The short-term memory span of humans imposes a limit on the amount and the structure of information communicated. We argue that route directions of varying granularity provide the means to respect these limits by efficient recoding.
-
ItemShared Ride Trip Planning in Large Transportation Networks(University of Utah, 2005)We present and discuss a specification for a simulation of shared ride trip planning in ad-hoc mobile geosensor networks. In this scenario, the nodes - clients with transportation demand, and hosts with transportation supply - have to plan routes and manage bookings collaboratively. The specification enables to compare different communication strategies for that purpose, with the goal to find an efficient communication strategy that still guarantees planning of acceptable trips in a continuously changing environment. In particular it makes the route planning strategies and booking mechanisms transparent, and shows their dependence on communication strategies.
-
ItemStarting to talk about place( 2011)
-
ItemLocation-based mobile games for spatial knowledge acquisition(CEMob2011, 2011-01-01)