502 research outputs found
Modelling individual accessibility using Bayesian networks: A capabilities approach
The ability of an individual to reach and engage with basic services such as healthcare, education and activities such as employment is a fundamental aspect of their wellbeing. Within transport studies, accessibility is considered to be a valuable concept that can be used to generate insights on issues related to social exclusion due to limited access to transport options. Recently, researchers have attempted to link accessibility with popular theories of social justice such as Amartya Sen's Capabilities Approach (CA). Such studies have set the theoretical foundations on the way accessibility can be expressed through the CA, however, attempts to operationalise this approach remain fragmented and predominantly qualitative in nature. The data landscape however, has changed over the last decade providing an unprecedented quantity of transport related data at an individual level. Mobility data from dfferent sources have the potential to contribute to the understanding of individual accessibility and its relation to phenomena such as social exclusion. At the same time, the unlabelled nature of such data present a considerable challenge, as a non-trivial step of inference is required if one is to deduce the transportation modes used and activities reached. This thesis develops a novel framework for accessibility modelling using the CA as theoretical foundation. Within the scope of this thesis, this is used to assess the levels of equality experienced by individuals belonging to different population groups and its link to transport related social exclusion. In the proposed approach, activities reached and transportation modes used are considered manifestations of individual hidden capabilities. A modelling framework using dynamic Bayesian networks is developed to quantify and assess the relationships and dynamics of the different components in fluencing the capabilities sets. The developed approach can also provide inferential capabilities for activity type and transportation mode detection, making it suitable for use with unlabelled mobility data such as Automatic Fare Collection Systems (AFC), mobile phone and social media. The usefulness of the proposed framework is demonstrated through three case studies. In the first case study, mobile phone data were used to explore the interaction of individuals with different public transportation modes. It was found that assumptions about individual mobility preferences derived from travel surveys may not always hold, providing evidence for the significance of personal characteristics to the choices of transportation modes. In the second case, the proposed framework is used for activity type inference, testing the limits of accuracy that can be achieved from unlabelled social media data. A combination of the previous case studies, the third case further defines a generative model which is used to develop the proposed capabilities approach to accessibility model. Using data from London's Automatic Fare Collection Systems (AFC) system, the elements of the capabilities set are explicitly de ned and linked with an individual's personal characteristics, external variables and functionings. The results are used to explore the link between social exclusion and transport disadvantage, revealing distinct patterns that can be attributed to different accessibility levels
Activity understanding and unusual event detection in surveillance videos
PhDComputer scientists have made ceaseless efforts to replicate cognitive video understanding abilities
of human brains onto autonomous vision systems. As video surveillance cameras become
ubiquitous, there is a surge in studies on automated activity understanding and unusual event detection
in surveillance videos. Nevertheless, video content analysis in public scenes remained a
formidable challenge due to intrinsic difficulties such as severe inter-object occlusion in crowded
scene and poor quality of recorded surveillance footage. Moreover, it is nontrivial to achieve
robust detection of unusual events, which are rare, ambiguous, and easily confused with noise.
This thesis proposes solutions for resolving ambiguous visual observations and overcoming unreliability
of conventional activity analysis methods by exploiting multi-camera visual context
and human feedback.
The thesis first demonstrates the importance of learning visual context for establishing reliable
reasoning on observed activity in a camera network. In the proposed approach, a new Cross
Canonical Correlation Analysis (xCCA) is formulated to discover and quantify time delayed pairwise
correlations of regional activities observed within and across multiple camera views. This
thesis shows that learning time delayed pairwise activity correlations offers valuable contextual
information for (1) spatial and temporal topology inference of a camera network, (2) robust person
re-identification, and (3) accurate activity-based video temporal segmentation. Crucially, in
contrast to conventional methods, the proposed approach does not rely on either intra-camera or
inter-camera object tracking; it can thus be applied to low-quality surveillance videos featuring
severe inter-object occlusions.
Second, to detect global unusual event across multiple disjoint cameras, this thesis extends
visual context learning from pairwise relationship to global time delayed dependency between
regional activities. Specifically, a Time Delayed Probabilistic Graphical Model (TD-PGM) is
proposed to model the multi-camera activities and their dependencies. Subtle global unusual
events are detected and localised using the model as context-incoherent patterns across multiple
camera views. In the model, different nodes represent activities in different decomposed re3
gions from different camera views, and the directed links between nodes encoding time delayed
dependencies between activities observed within and across camera views. In order to learn optimised
time delayed dependencies in a TD-PGM, a novel two-stage structure learning approach
is formulated by combining both constraint-based and scored-searching based structure learning
methods.
Third, to cope with visual context changes over time, this two-stage structure learning approach
is extended to permit tractable incremental update of both TD-PGM parameters and its
structure. As opposed to most existing studies that assume static model once learned, the proposed
incremental learning allows a model to adapt itself to reflect the changes in the current
visual context, such as subtle behaviour drift over time or removal/addition of cameras. Importantly,
the incremental structure learning is achieved without either exhaustive search in a large
graph structure space or storing all past observations in memory, making the proposed solution
memory and time efficient.
Forth, an active learning approach is presented to incorporate human feedback for on-line
unusual event detection. Contrary to most existing unsupervised methods that perform passive
mining for unusual events, the proposed approach automatically requests supervision for critical
points to resolve ambiguities of interest, leading to more robust detection of subtle unusual
events. The active learning strategy is formulated as a stream-based solution, i.e. it makes decision
on-the-fly on whether to request label for each unlabelled sample observed in sequence.
It selects adaptively two active learning criteria, namely likelihood criterion and uncertainty criterion
to achieve (1) discovery of unknown event classes and (2) refinement of classification
boundary.
The effectiveness of the proposed approaches is validated using videos captured from busy
public scenes such as underground stations and traffic intersections
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Fuzzy transfer learning in human activity recognition.
Assisted living environments are incorporated with diďŹerent technological solutions to improve the quality of life and well-being. In recent years, there has been a growing interest in the research community on how to develop evolving solutions to aid assisted living. DiďŹerent techniques have been studied to address the need for technological systems which are intelligent enough to evolve their knowledge to solve tasks which have not been previously encountered. One such approach is Transfer Learning (TL), for example, between humans and robots.
Humans excel at dealing with everyday activities, learning and adapting to diďŹerent activities. This comprises diďŹerent complex techniques which enable the lifelong learning process from observation of our environment. To obtain similar learning in assistive agents, TL is needed. The aim of the research reported in this thesis is to address the challenge associated with learning and reuse of knowledge by assistive agents in an Ambient Assisted Living (AAL) environment. In this thesis, a novel approach to transfer learning of human activities through the combination of three methods; TL, Fuzzy Systems (FS) and Human Activity Recognition (HAR) is presented. Through the incorporation of FS into the proposed approach, uncertainty that is evident in the dynamic nature of human activities are embedded into the learning model.
This research is focused on applications in assistive robotics. This is with a purpose of enabling assistive robots in AAL environments to acquire knowledge of such activities as are performed by humans. To achieve this, an extensive investigation into existing learning methods applied in human activities is conducted. The investigation encompasses current state-of-the-art of TL approaches employed in skill transfer across diďŹerent but contextually related activities.
To address the research questions identiďŹed in the thesis, the contributions of the methodology employed are in three main categories; 1) Firstly, a novel framework for human activity learning from information observed. Experiments are conducted on selected human activities to acquire enough information for building the framework. From the acquired information, relevant features extracted are used in a learning model to recognise diďŹerent activities. 2) Secondly, the sequence of occurrence(s) of tasks in an activity needs to be considered in the learning process. Therefore, in this research, a novel technique for adaptive learning of activity sequences from acquired information is developed. 3) Finally, from the sequence obtained, a novel technique for transfer of human activity across heterogeneous feature space existing between a human and an assistive robot is developed. These categories form the basis of the TL framework modelled in this research.
The framework proposed is applied to TL of human activity from data generated experimentally and benchmark datasets of various classes of human activities. The results presented in this thesis show that exploring the process of human activity learning is an important aspect in the TL framework. The features extracted suďŹciently distinguish relevant patterns for each activity. Also, the results demonstrate the ability of the methodology to learn and predict human actions with a high degree of certainty. This encourages the use of TL in assisted living environments and other applications. This and many more applications of TL in technology would be a potential driver of the next revolution in artiďŹcial intelligence
Unsupervised monitoring of an elderly person\u27s activities of daily living using Kinect sensors and a power meter
The need for greater independence amongst the growing population of elderly people has made the concept of âageing in placeâ an important area of research. Remote home monitoring strategies help the elderly deal with challenges involved in ageing in place and performing the activities of daily living (ADLs) independently. These monitoring approaches typically involve the use of several sensors, attached to the environment or person, in order to acquire data about the ADLs of the occupant being monitored.
Some key drawbacks associated with many of the ADL monitoring approaches proposed for the elderly living alone need to be addressed. These include the need to label a training dataset of activities, use wearable devices or equip the house with many sensors. These approaches are also unable to concurrently monitor physical ADLs to detect emergency situations, such as falls, and instrumental ADLs to detect deviations from the daily routine. These are all indicative of deteriorating health in the elderly.
To address these drawbacks, this research aimed to investigate the feasibility of unsupervised monitoring of both physical and instrumental ADLs of elderly people living alone via inexpensive minimally intrusive sensors. A hybrid framework was presented which combined two approaches for monitoring an elderly occupantâs physical and instrumental ADLs. Both approaches were trained based on unlabelled sensor data from the occupantâs normal behaviours. The data related to physical ADLs were captured from Kinect sensors and those related to instrumental ADLs were obtained using a combination of Kinect sensors and a power meter. Kinect sensors were employed in functional areas of the monitored environment to capture the occupantâs locations and 3D structures of their physical activities. The power meter measured the power consumption of home electrical appliances (HEAs) from the electricity panel.
A novel unsupervised fuzzy approach was presented to monitor physical ADLs based on depth maps obtained from Kinect sensors. Epochs of activities associated with each monitored location were automatically identified, and the occupantâs behaviour patterns during each epoch were represented through the combinations of fuzzy attributes. A novel membership function generation technique was presented to elicit membership functions for attributes by analysing the data distribution of attributes while excluding noise and outliers in the data. The occupantâs behaviour patterns during each epoch of activity were then classified into frequent and infrequent categories using a data mining technique. Fuzzy rules were learned to model frequent behaviour patterns. An alarm was raised when the occupantâs behaviour in new data was recognised as frequent with a longer than usual duration or infrequent with a duration exceeding a data-driven value.
Another novel unsupervised fuzzy approach to monitor instrumental ADLs took unlabelled training data from Kinect sensors and a power meter to model the key features of instrumental ADLs. Instrumental ADLs in the training dataset were identified based on associating the occupantâs locations with specific power signatures on the power line. A set of fuzzy rules was then developed to model the frequency and regularity of the instrumental activities tailored to the occupant. This set was subsequently used to monitor new data and to generate reports on deviations from normal behaviour patterns.
As a proof of concept, the proposed monitoring approaches were evaluated using a dataset collected from a real-life setting. An evaluation of the results verified the high accuracy of the proposed technique to identify the epochs of activities over alternative techniques. The approach adopted for monitoring physical ADLs was found to improve elderly monitoring. It generated fuzzy rules that could represent the personâs physical ADLs and exclude noise and outliers in the data more efficiently than alternative approaches. The performance of different membership function generation techniques was compared. The fuzzy rule set obtained from the output of the proposed technique could accurately classify more scenarios of normal and abnormal behaviours.
The approach for monitoring instrumental ADLs was also found to reliably distinguish power signatures generated automatically by self-regulated devices from those generated as a result of an elderly personâs instrumental ADLs. The evaluations also showed the effectiveness of the approach in correctly identifying elderly peopleâs interactions with specific HEAs and tracking simulated upward and downward deviations from normal behaviours. The fuzzy inference system in this approach was found to be robust in regards to errors when identifying instrumental ADLs as it could effectively classify normal and abnormal behaviour patterns despite errors in the list of the used HEAs
Non-intrusive load monitoring techniques for activity of daily living recognition
Esta tesis nace con la motivaciĂłn de afrontar dos grandes problemas de nuestra era: la falta de recursos energĂŠticos y el envejecimiento de la poblaciĂłn.
Respecto al primer problema, nace en la primera dĂŠcada de este siglo el concepto de Smart Grids con el objetivo de alcanzar la eficiencia energĂŠtica. Numerosos paĂses comienzan a realizar despliegues masivos de contadores inteligentes ("Smart Meters"), lo que despierta el interĂŠs de investigadores que comienzan a desarrollar nuevas tĂŠcnicas para predecir la demanda. AsĂ, los sistemas NILM (Non-Intrusive Load Monitoring) tratan de predecir el consumo individual de los dispositivos conectados a partir de un Ăşnico sensor: el contador inteligente.
Por otra parte, los grandes avances en la medicina moderna han permitido que nuestra esperanza de vida aumente considerablemente. No obstante, esta longevidad, junto con la baja fertilidad en los paĂses desarrollados, tiene un efecto secundario: el envejecimiento de la poblaciĂłn. Unos de los grandes avances es la incorporaciĂłn de la tecnologĂa en la vida cotidiana, lo que ayuda a los mĂĄs mayores a llevar una vida independiente. El despliegue de una red de sensores dentro de la vivienda permite su monitorizaciĂłn y asistencia en las tareas cotidianas. Sin embargo, son intrusivos, no escalables y, en algunas ocasiones, de alto coste, por lo que no estĂĄn preparados para hacer frente al incremento de la demanda de esta comunidad.
Esta tesis doctoral nace de la motivaciĂłn de afrontar estos problemas y tiene dos objetivos principales: lograr un modelo de monitorizaciĂłn sostenible para personas mayores y, a su vez, dar un valor aĂąadido a los sistemas NILM que despierte el interĂŠs del usuario final. Con este objetivo, se presentan nuevas tĂŠcnicas de monitorizaciĂłn basadas en NILM, aunando lo mejor de ambos campos. Esto supone un ahorro considerable de recursos en la monitorizaciĂłn, ya que Ăşnicamente se necesita un sensor: el contador inteligente; lo cual da escalabilidad a estos sistemas.
Las contribuciones de esta tesis se dividen en dos bloques principales. En el primero se proponen nuevas tĂŠcnicas NILM optimizadas para la detecciĂłn de la actividad humana. AsĂ, se desarrolla una propuesta basada en detecciĂłn de eventos (conexiones de dispositivos) en tiempo real y su clasificaciĂłn a un dispositivo. Con el objetivo de que pueda integrarse en contadores inteligentes. Cabe destacar que el clasificador se basa en modelos generalizados de dispositivos y no necesita conocimiento especĂfico de la vivienda.
El segundo bloque presenta tres nuevas tĂŠcnicas de monitorizaciĂłn de personas mayores basadas en NILM. El objetivo es proporcionar una monitorizaciĂłn bĂĄsica pero eficiente y altamente escalable, ahorrando en recursos. Los procesos Cox, log Gaussian Cox Processes (LGCP), monitorizan un Ăşnico dispositivo si la rutina estĂĄ estrechamente ligada a este. AsĂ, se propone un sistema de alarmas si se detectan cambios en el comportamiento. LGCP tiene la ventaja de poder modelar periodicidades e incertidumbres propias del comportamiento humano. Cuando la rutina no depende de un Ăşnico dispositivo, se proponen dos tĂŠcnicas: una basada en gaussianas mixtas, Gaussian Mixture Models (GMM); y la otra basada en la TeorĂa de la Evidencia de Dempster-Shafer (DST). Ambas monitorizan y detectan deterioros en la actividad, causados por enfermedades como la demencia y el alzhĂŠimer. Ănicamente DST usa incertidumbres que simulan mejor el comportamiento humano y, por tanto, permite alarmas en caso de un repentino desvĂo.
Finalmente, todas las propuestas han sido validadas mediante la evaluaciĂłn de mĂŠtricas y la obtenciĂłn de resultados experimentales. Para ello, se han usado medidas de escenarios reales que han sido recopiladas en bases de datos. Los resultados obtenidos han sido satisfactorios, demostrando que este tipo de monitorizaciĂłn es posible y muy beneficioso para nuestra sociedad. AdemĂĄs, se ha dado a lugar nuevas propuestas que serĂĄn desarrolladas en el futuro.
CĂłdigos UNESCO: 120320 - sistemas de control medico, 332201 â distribuciĂłn de la energĂa, 120701 â anĂĄlisis de actividades, 120304 â inteligencia artificial, 120807 â plausibilidad, 221402 â patrones
Making music through real-time voice timbre analysis: machine learning and timbral control
PhDPeople can achieve rich musical expression through vocal sound { see for example
human beatboxing, which achieves a wide timbral variety through a range of
extended techniques. Yet the vocal modality is under-exploited as a controller
for music systems. If we can analyse a vocal performance suitably in real time,
then this information could be used to create voice-based interfaces with the
potential for intuitive and ful lling levels of expressive control.
Conversely, many modern techniques for music synthesis do not imply any
particular interface. Should a given parameter be controlled via a MIDI keyboard,
or a slider/fader, or a rotary dial? Automatic vocal analysis could provide
a fruitful basis for expressive interfaces to such electronic musical instruments.
The principal questions in applying vocal-based control are how to extract
musically meaningful information from the voice signal in real time, and how
to convert that information suitably into control data. In this thesis we address
these questions, with a focus on timbral control, and in particular we
develop approaches that can be used with a wide variety of musical instruments
by applying machine learning techniques to automatically derive the mappings
between expressive audio input and control output. The vocal audio signal is
construed to include a broad range of expression, in particular encompassing
the extended techniques used in human beatboxing.
The central contribution of this work is the application of supervised and
unsupervised machine learning techniques to automatically map vocal timbre
to synthesiser timbre and controls. Component contributions include a delayed
decision-making strategy for low-latency sound classi cation, a regression-tree
method to learn associations between regions of two unlabelled datasets, a fast
estimator of multidimensional di erential entropy and a qualitative method for
evaluating musical interfaces based on discourse analysis
An Insect-Inspired Target Tracking Mechanism for Autonomous Vehicles
Target tracking is a complicated task from an engineering perspective, especially where targets are small and seen against complex natural environments. Due to the high demand for robust target tracking algorithms a great deal of research has focused on this area. However, most engineering solutions developed for this purpose are often unreliable in real world conditions or too computationally expensive to be used in real-time applications. While engineering methods try to solve the problem of target detection and tracking by using high resolution input images, fast processors, with typically computationally expensive methods, a quick glance at nature provides evidence that practical real world solutions for target tracking exist. Many animals track targets for predation, territorial or mating purposes and with millions of years of evolution behind them, it seems reasonable to assume that these solutions are highly efficient. For instance, despite their low resolution compound eyes and tiny brains, many flying insects have evolved superb abilities to track targets in visual clutter even in the presence of other distracting stimuli, such as swarms of prey and conspecifics. The accessibility of the dragonfly for stable electrophysiological recordings makes this insect an ideal and tractable model system for investigating the neuronal correlates for complex tasks such as target pursuit. Studies on dragonflies identified and characterized a set of neurons likely to mediate target detection and pursuit referred to as âsmall target motion detectorâ (STMD) neurons. These neurons are selective for tiny targets, are velocity-tuned, contrast-sensitive and respond robustly to targets even against the motion of background. These neurons have shown several high-order properties which can contribute to the dragonflyâs ability to robustly pursue prey with over a 97% success rate. These include the recent electrophysiological observations of response âfacilitationâ (a slow build-up of response to targets that move on long, continuous trajectories) and âselective attentionâ, a competitive mechanism that selects one target from alternatives. In this thesis, I adopted a bio-inspired approach to develop a solution for the problem of target tracking and pursuit. Directly inspired by recent physiological breakthroughs in understanding the insect brain, I developed a closed-loop target tracking system that uses an active saccadic gaze fixation strategy inspired by insect pursuit. First, I tested this model in virtual world simulations using MATLAB/Simulink. The results of these simulations show robust performance of this insect-inspired model, achieving high prey capture success even within complex background clutter, low contrast and high relative speed of pursued prey. Additionally, these results show that inclusion of facilitation not only substantially improves success for even short-duration pursuits, it also enhances the ability to âattendâ to one target in the presence of distracters. This inspect-inspired system has a relatively simple image processing strategy compared to state-of-the-art trackers developed recently for computer vision applications. Traditional machine vision approaches incorporate elaborations to handle challenges and non-idealities in the natural environments such as local flicker and illumination changes, and non-smooth and non-linear target trajectories. Therefore, the question arises as whether this insect inspired tracker can match their performance when given similar challenges? I investigated this question by testing both the efficacy and efficiency of this insect-inspired model in open-loop, using a widely-used set of videos recorded under natural conditions. I directly compared the performance of this model with several state-of-the-art engineering algorithms using the same hardware, software environment and stimuli. This insect-inspired model exhibits robust performance in tracking small moving targets even in very challenging natural scenarios, outperforming the best of the engineered approaches. Furthermore, it operates more efficiently compared to the other approaches, in some cases dramatically so. Computer vision literature traditionally test target tracking algorithms only in open-loop. However, one of the main purposes for developing these algorithms is implementation in real-time robotic applications. Therefore, it is still unclear how these algorithms might perform in closed-loop real-world applications where inclusion of sensors and actuators on a physical robot results in additional latency which can affect the stability of the feedback process. Additionally, studies show that animals interact with the target by changing eye or body movements, which then modulate the visual inputs underlying the detection and selection task (via closed-loop feedback). This active vision system may be a key to exploiting visual information by the simple insect brain for complex tasks such as target tracking. Therefore, I implemented this insect-inspired model along with insect active vision in a robotic platform. I tested this robotic implementation both in indoor and outdoor environments against different challenges which exist in real-world conditions such as vibration, illumination variation, and distracting stimuli. The experimental results show that the robotic implementation is capable of handling these challenges and robustly pursuing a target even in highly challenging scenarios.Thesis (Ph.D.) -- University of Adelaide, School of Mechanical Engineering, 201
Mobile phone technology as an aid to contemporary transport questions in walkability, in the context of developing countries
The emerging global middle class, which is expected to double by 2050 desires more walkable, liveable neighbourhoods, and as distances between work and other amenities increases, cities are becoming less monocentric and becoming more polycentric. African cities could be described as walking cities, based on the number of people that walk to their destinations as opposed to other means of mobility but are often not walkable. Walking is by far the most popular form of transportation in Africaâs rapidly urbanising cities, although it is not often by choice rather a necessity. Facilitating this primary mode, while curbing the growth of less sustainable mobility uses requires special attention for the safety and convenience of walking in view of a Global South context. In this regard, to further promote walking as a sustainable mobility option, there is a need to assess the current state of its supporting infrastructure and begin giving it higher priority, focus and emphasis. Mobile phones have emerged as a useful alternative tool to collect this data and audit the state of walkability in cities. They eliminate the inaccuracies and inefficiencies of human memories because smartphone sensors such as GPS provides information with accuracies within 5m, providing superior accuracy and precision compared to other traditional methods. The data is also spatial in nature, allowing for a range of possible applications and use cases. Traditional inventory approaches in walkability often only revealed the perceived walkability and accessibility for only a subset of journeys. Crowdsourcing the perceived walkability and accessibility of points of interest in African cities could address this, albeit aspects such as ease-of-use and road safety should also be considered. A tool that crowdsources individual pedestrian experiences; availability and state of pedestrian infrastructure and amenities, using state-of-the-art smartphone technology, would over time also result in complete surveys of the walking environment provided such a tool is popular and safe. This research will illustrate how mobile phone applications currently in the market can be improved to offer more functionality that factors in multiple sensory modalities for enhanced visual appeal, ease of use, and aesthetics. The overarching aim of this research is, therefore, to develop the framework for and test a pilot-version mobile phone-based data collection tool that incorporates emerging technologies in collecting data on walkability. This research project will assess the effectiveness of the mobile application and test the technical capabilities of the system to experience how it operates within an existing infrastructure. It will continue to investigate the use of mobile phone technology in the collection of user perceptions of walkability, and the limitations of current transportation-based mobile applications, with the aim of developing an application that is an improvement to current offerings in the market. The prototype application will be tested and later piloted in different locations around the globe. Past studies are primarily focused on the development of transport-based mobile phone applications with basic features and limited functionality. Although limited progress has been made in integrating emerging advanced technologies such as Augmented Reality (AR), Machine Learning (ML), Big Data analytics, amongst others into mobile phone applications; what is missing from these past examples is a comprehensive and structured application in the transportation sphere. In turn, the full research will offer a broader understanding of the iii information gathered from these smart devices, and how that large volume of varied data can be better and more quickly interpreted to discover trends, patterns, and aid in decision making and planning. This research project attempts to fill this gap and also bring new insights, thus promote the research field of transportation data collection audits, with particular emphasis on walkability audits. In this regard, this research seeks to provide insights into how such a tool could be applied in assessing and promoting walkability as a sustainable and equitable mobility option. In order to get policy-makers, analysts, and practitioners in urban transport planning and provision in cities to pay closer attention to making better, more walkable places, appealing to them from an efficiency and business perspective is vital. This crowdsourced data is of great interest to industry practitioners, local governments and research communities as Big Data, and to urban communities and civil society as an input in their advocacy activities. The general findings from the results of this research show clear evidence that transport-based mobile phone applications currently available in the market are increasingly getting outdated and are not keeping up with new and emerging technologies and innovations. It is also evident from the results that mobile smartphones have revolutionised the collection of transport-related information hence the need for new initiatives to help take advantage of this emerging opportunity. The implications of these findings are that more attention needs to be paid to this niche going forward. This research project recommends that more studies, particularly on what technologies and functionalities can realistically be incorporated into mobile phone applications in the near future be done as well as on improving the hardware specifications of mobile phone devices to facilitate and support these emerging technologies whilst keeping the cost of mobile devices as low as possible
Intelligent Interpretation of Machine Condition Data
This dissertation argues that classification is an effective tool in the prediction of machine condition. A system based on continuous learning can be developed to automate the laborious process of interpretation of symptoms derived from collected data into various normal and fault modes. In order to defend these arguments, the study seeks to explain, how prediction works and how the results can be evaluated.
The study explores the philosophy of condition monitoring in assuring the safe and uninterrupted operation of machines. Condition monitoring provides essential information for the maintenance and operability of process plants. Vibration monitoring is considered as one of the most important techniques to offer adequate and reliable information to maintain rotating machines in a condition, where they can perform their required functions without failure for a specified time period, when used under specified conditions.
In addition of detection and collection of data that indicate the state of a machine, condition monitoring includes the examination of symptoms and syndromes to determine the nature of faults or failures. High confidence level is required in both diagnostics and prognostics, because misinterpretation of condition related data may lead into severe economic consequences.
The diagnostics of machine condition is laborious and challenging. It requires a lot of analystâs effort and time to detect an anomaly and even more to identify a fault mode. This study presents methods to predict the current condition of machines using training data collected from various normal and fault modes on the same machine or substantially similar machines. Learning algorithms offer possibilities to increase the confidence level of prediction.
The study presents results on practical experiments to demonstrate the principles of continuous learning processes. The experiments rely on data collected from wind turbine gearboxes, which are extremely difficult to be diagnosed, because of the large amount of data and symptoms. The study proofs that significant improvements to current confidence level of prediction can be achieved by the use of learning system
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