Developing multidimensional metrics for evaluating paediatric neurodevelopmental disorders

Healthy brain functioning depends on efficient communication of information between brain regions, forming complex networks. By quantifying synchronisation between brain regions, a functionally connected brain network can be articulated. In neurodevelopmental disorders, where diagnosis is based on measures of behaviour and tasks, a measure of the underlying biological mechanisms holds promise as a potential clinical tool. Graph theory provides a tool for investigating the neural correlates of neuropsychiatric disorders, where there is disruption of efficient communication within and between brain networks. This research aimed to use recent conceptualisation of graph theory, along with measures of behaviour and cognitive functioning, to increase understanding of the neurobiological risk factors of atypical development. Using magnetoencephalography to investigate frequency-specific temporal dynamics at rest, the research aimed to identify potential biological markers derived from sensor-level whole-brain functional connectivity. Whilst graph theory has proved valuable for insight into network efficiency, its application is hampered by two limitations. First, its measures have hardly been validated in MEG studies, and second, graph measures have been shown to depend on methodological assumptions that restrict direct network comparisons. The first experimental study (Chapter 3) addressed the first limitation by examining the reproducibility of graph-based functional connectivity and network parameters in healthy adult volunteers. Subsequent chapters addressed the second limitation through adapted minimum spanning tree (a network analysis approach that allows for unbiased group comparisons) along with graph network tools that had been shown in Chapter 3 to be highly reproducible. Network topologies were modelled in healthy development (Chapter 4), and atypical neurodevelopment (Chapters 5 and 6). The results provided support to the proposition that measures of network organisation, derived from sensor-space MEG data, offer insights helping to unravel the biological basis of typical brain maturation and neurodevelopmental conditions, with the possibility of future clinical utility.

Description and training of neural network dynamics

Attractor properties of a popular discrete-time neural network model are illustrated through numerical simulations. The most complex dynamics is found to occur within particular ranges of parameters controlling the symmetry and magnitude of the weight matrix. A small network model is observed to produce fixed points, limit cycles, mode-locking, the Ruelle-Takens route to chaos, and the period-doubling route to chaos. Training algorithms for tuning this dynamical behaviour are discussed. Training can be an easy or difficult task, depending whether the problem requires the use of temporal information distributed over long time intervals. Such problems require training algorithms which can handle hidden nodes. The most prominent of these algorithms, back propagation through time, solves the temporal credit assignment problem in a way which can work only if the relevant information is distributed locally in time. The Moving Targets algorithm works for the more general case, but is computationally intensive, and prone to local minima.

Une étude générique du metteur en scène au théâtre:son émergence et son rôle moderne et contemporain

The theatre director (metteur en scene in French) is a relatively new figure in theatre practice. It was not until the I820s that the term 'mise en scene' gained currency. The term 'director' was not in general use until the I880s. The emergence and the role of the director has been considered from a variety of perspectives, either through the history of theatre (Allevy, Jomaron, Sarrazac, Viala, Biet and Triau); the history of directing (Chinoy and Cole, Boll, Veinstein, Roubine); semiotic approaches to directing (Whitmore, Miller, Pavis); the semiotics of performance (De Marinis); generic approaches to the mise en scene (Thomasseau, Banu); post-dramatic approaches to theatre (Lehmann); approaches to performance process and the specifics of rehearsal methodology (Bradby and Williams, Giannachi and Luckhurst, Picon-Vallin, Styan). What the scholarly literature has not done so far is to map the parameters necessarily involved in the directing process, and to incorporate an analysis of the emergence of the theatre director during the modem period and consider its impact on contemporary performance practice. Directing relates primarily to the making of the performance guided by a director, a single figure charged with the authority to make binding artistic decisions. Each director may have her/his own personal approaches to the process of preparation prior to a show. This is exemplified, for example, by the variety of terms now used to describe the role and function of directing, from producer, to facilitator or outside eye. However, it is essential at the outset to make two observations, each of which contributes to a justification for a generic analysis (as opposed to a genetic approach). Firstly, a director does not work alone, and cooperation with others is involved at all stages of the process. Secondly, beyond individual variation, the role of the director remains twofold. The first is to guide the actors (meneur de jeu, directeur d'acteurs, coach); the second is to make a visual representation in the performance space (set designer, stage designer, costume designer, lighting designer, scenographe). The increasing place of scenography has brought contemporary theatre directors such as Wilson, Castellucci, Fabre to produce performances where the performance space becomes a semiotic dimension that displaces the primacy of the text. The play is not, therefore, the sole artistic vehicle for directing. This definition of directing obviously calls for a definition of what the making of the performance might be. The thesis defines the making of the performance as the activity of bringing a social event, by at least one performer, providing visual and/or textual meaning in a performance space. This definition enables us to evaluate four consistent parameters throughout theatre history: first, the social aspect associated to the performance event; second, the devising process which may be based on visual and/or textual elements; third, the presence of at least one performer in the show; fourth, the performance space (which is not simply related to the theatre stage). Although the thesis focuses primarily on theatre practice, such definition blurs the boundaries between theatre and other collaborative artistic disciplines (cinema, opera, music and dance). These parameters illustrate the possibility to undertake a generic analysis of directing, and resonate with the historical, political and artistic dimensions considered. Such a generic perspective on the role of the director addresses three significant questions: an historical question: how/why has the director emerged?; a sociopolitical question: how/why was the director a catalyst for the politicisation of theatre, and subsequently contributed to the rise of State-funded theatre policy?; and an artistic one: how/why the director has changed theatre practice and theory in the twentieth-century? Directing for the theatre as an artistic activity is a historically situated phenomenon. It would seem only natural from a contemporary perspective to associate the activity of directing to the function of the director. This is relativised, however, by the question of how the performance was produced before the modern period. The thesis demonstrates that the rise of the director is a progressive and historical phenomenon (Dort) rather than a mere invention (Viala, Sarrazac). A chronological analysis of the making of the performance throughout theatre history is the most useful way to open the study. In order to understand the emergence of the director, the research methodology assesses the interconnection of the four parameters above throughout four main periods of theatre history: the beginning of the Renaissance (meneur de jeu), the classical age (actor-manager and stage designer-manager), the modern period (director) and the contemporary period (director-facilitator, performer). This allows us properly to appraise the progressive emergence of the director, as well as to make an analysis of her/his modern and contemporary role. The first chapter argues that the physical separation between the performance space and its audience, which appeared in the early fifteenth-century, has been a crucial feature in the scenographic, aesthetic, political and social organisation of the performance. At the end of the Middle Ages, French farces which raised socio-political issues (see Bakhtin) made a clear division on a single outdoor stage (treteau) between the actors and the spectators, while religious plays (drame fiturgique, mystere) were mostly performed on various outdoor and opened multispaces. As long as the performance was liturgical or religious, and therefore confined within an acceptable framework, it was allowed. At the time, the French ecclesiastical and civil authorities tried, on several occasions, to prohibit staged performances. As a result, practitioners developed non-official indoor spaces, the Theatre de fa Trinite (1398) being the first French indoor theatre recognized by scholars. This self-exclusion from the open public space involved breaking the accepted rules by practitioners (e.g. Les Confreres de fa Passion), in terms of themes but also through individual input into a secular performance rather than the repetition of commonly known religious canvases. These developments heralded the authorised theatres that began to emerge from the mid-sixteenth century, which in some cases were subsidised in their construction. The construction of authorised indoor theatres associated with the development of printing led to a considerable increase in the production of dramatic texts for the stage. Profoundly affecting the reception of the dramatic text by the audience, the distance between the stage and the auditorium accompanied the changing relationship between practitioners and spectators. This distance gave rise to a major development of the role of the actor and of the stage designer. The second chapter looks at the significance of both the actor and set designer in the devising process of the performance from the sixteenth-century to the end of the nineteenth-century. The actor underwent an important shift in function in this period from the delivery of an unwritten text that is learned in the medieval oral tradition to a structured improvisation produced by the commedia dell 'arte. In this new form of theatre, a chef de troupe or an experienced actor shaped the story, but the text existed only through the improvisation of the actors. The preparation of those performances was, moreover, centred on acting technique and the individual skills of the actor. From this point, there is clear evidence that acting began to be the subject of a number of studies in the mid-sixteenth-century, and more significantly in the seventeenth-century, in Italy and France. This is revealed through the implementation of a system of notes written by the playwright to the actors (stage directions) in a range of plays (Gerard de Vivier, Comedie de la Fidelite Nuptiale, 1577). The thesis also focuses on Leoni de' Sommi (Quatro dialoghi, 1556 or 1565) who wrote about actors' techniques and introduced the meneur de jeu in Italy. The actor-manager (meneur de jeu), a professional actor, who scholars have compared to the director (see Strihan), trained the actors. Nothing, however, indicates that the actor-manager was directing the visual representation of the text in the performance space. From the end of the sixteenth-century, the dramatic text began to dominate the process of the performance and led to an expansion of acting techniques, such as the declamation. Stage designers carne from outside the theatre tradition and played a decisive role in the staging of religious celebrations (e.g. Actes des Apotres, 1536). In the sixteenth-century, both the proscenium arch and the borders, incorporated in the architecture of the new indoor theatres (theatre a l'italienne), contributed to create all kinds of illusions on the stage, principally the revival of perspective. This chapter shows ongoing audience demands for more elaborate visual effects on the stage. This led, throughout the classical age, and even more so during the eighteenth-century, to grant the stage design practitioner a major role in the making of the performance (see Ciceri). The second chapter demonstrates that the guidance of the actors and the scenographic conception, which are the artistic components of the role of the director, appear to have developed independently from one another until the nineteenth-century. The third chapter investigates the emergence of the director per se. The causes for this have been considered by a number of scholars, who have mainly identified two: the influence of Naturalism (illustrated by the Meiningen Company, Antoine, and Stanislavski) and the invention of electric lighting. The influence of the Naturalist movement on the emergence of the modem director in the late nineteenth-century is often considered as a radical factor in the history of theatre practice. Naturalism undoubtedly contributed to changes in staging, costume and lighting design, and to a more rigorous commitment to the harmonisation and visualisation of the overall production of the play. Although the art of theatre was dependent on the dramatic text, scholars (Osborne) demonstrate that the Naturalist directors did not strictly follow the playwright's indications written in the play in the late nineteenth-century. On the other hand, the main characteristic of directing in Naturalism at that time depended on a comprehensive understanding of the scenography, which had to respond to the requirements of verisimilitude. Electric lighting contributed to this by allowing for the construction of a visual narrative on stage. However, it was a master technician, rather than an emergent director, who was responsible for key operational decisions over how to use this emerging technology in venues such as the new Bayreuth theatre in 1876. Electric lighting reflects a normal technological evolution and cannot be considered as one of the main causes of the emergence of the director. Two further causes of the emergence of the director, not considered in previous studies, are the invention of cinema and the Symbolist movement (Lugne-Poe, Meyerhold). Cinema had an important technological influence on the practitioners of the Naturalist movement. In order to achieve a photographic truth on the stage (tableau, image), Naturalist directors strove to decorate the stage with the detailed elements that would be expected to be found if the situation were happening in reality. Film production had an influence on the work of actors (Walter). The filmmaker took over a primary role in the making of the film, as the source of the script, the filming process and the editing of the film. This role influenced the conception that theatre directors had of their own work. It is this concept of the director which influenced the development of the theatre director. As for the Symbolist movement, the director's approach was to dematerialise the text of the playwright, trying to expose the spirit, movement, colour and rhythm of the text. Therefore, the Symbolists disengaged themselves from the material aspect of the production, and contributed to give greater artistic autonomy to the role of the director. Although the emergence of the director finds its roots amongst the Naturalist practitioners (through a rigorous attempt to provide a strict visual interpretation of the text on stage), the Symbolist director heralded the modem perspective of the making of performance. The emergence of the director significantly changed theatre practice and theory. For instance, the rehearsal period became a clear work in progress, a platform for both developing practitioners' techniques and staging the show. This chapter explores and contrasts several practitioners' methods based on the two aspects proposed for the definition of the director (guidance of the actors and materialisation of a visual space). The fourth chapter argues that the role of the director became stronger, more prominent, and more hierarchical, through a more political and didactic approach to theatre as exemplified by the cases of France and Germany at the end of the nineteenth-century and through the First World War. This didactic perspective to theatre defines the notion of political theatre. Political theatre is often approached by the literature (Esslin, Willett) through a Marxist interpretation of the great German directors' productions (Reinhardt, Piscator, Brecht). These directors certainly had a great influence on many directors after the Second World War, such as Jean Vilar, Judith Molina, Jean-Louis Barrault, Roger Planchon, Augusto Boal, and others. This chapter demonstrates, moreover, that the director was confirmed through both ontological and educational approaches to the process of making the performance, and consequently became a central and paternal figure in the organisational and structural processes practiced within her/his theatre company. In this way, the stance taken by the director influenced the State authorities in establishing theatrical policy. This is an entirely novel scholarly contribution to the study of the director. The German and French States were not indifferent to the development of political theatre. A network of public theatres was thus developed in the inter-war period, and more significantly after the Second World War. The fifth chapter shows how State theatre policies establish its sources in the development of political theatre, and more specifically in the German theatre trade union movement (Volksbiihne) and the great directors at the end of the nineteenth-century. French political theatre was more influenced by playwrights and actors (Romain Rolland, Louise Michel, Louis Lumet, Emile Berny). French theatre policy was based primarily on theatre directors who decentralised their activities in France during both the inter-war period and the German occupation. After the Second World War, the government established, through directors, a strong network of public theatres. Directors became both the artistic director and the executive director of those institutionalised theatres. The institution was, however, seriously shaken by the social and political upheaval of 1968. It is the link between the State and the institution in which established directors were entangled that was challenged by the young emerging directors who rejected institutionalised responsibility in favour of the autonomy of the artist in the 1960s. This process is elucidated in chapter five. The final chapter defines the contemporary role of the director in contrasting thework of a number of significant young theatre practitioners in the 1960s such as Peter Brook, Ariane Mnouchkine, The Living Theater, Jerzy Grotowski, Augusto Boal, Eugenio Barba, all of whom decided early on to detach their companies from any form of public funding. This chapter also demonstrates how they promoted new forms of performance such as the performance of the self. First, these practitioners explored new performance spaces outside the traditional theatre building. Producing performances in a non-dedicated theatre place (warehouse, street, etc.) was a more frequent practice in the 1960s than before. However, the recent development of cybertheatre questions both the separation of the audience and the practitioners and the place of the director's role since the 1990s. Secondly, the role of the director has been multifaceted since the 1960s. On the one hand, those directors, despite all their different working methods, explored western and non-western acting techniques based on both personal input and collective creation. They challenged theatrical conventions of both the character and the process of making the performance. On the other hand, recent observations and studies distinguish the two main functions of the director, the acting coach and the scenographe, both having found new developments in cinema, television, and in various others events. Thirdly, the contemporary director challenges the performance of the text. In this sense, Antonin Artaud was a visionary. His theatre illustrates the need for the consideration of the totality of the text, as well as that of theatrical production. By contrasting the theories of Artaud, based on a non-dramatic form of theatre, with one of his plays (Le Jet de Sang), this chapter demonstrates how Artaud examined the process of making the performance as a performance. Live art and autobiographical performance, both taken as directing the se(f, reinforce this suggestion. Finally, since the 1990s, autobiographical performance or the performance of the self is a growing practical and theoretical perspective in both performance studies and psychology-related studies. This relates to the premise that each individual is making a representation (through memory, interpretation, etc.) of her/his own life (performativity). This last section explores the links between the place of the director in contemporary theatre and performers in autobiographical practices. The role of the traditional actor is challenged through non-identification of the character in the play, while performers (such as Chris Burden, Ron Athey, Orlan, Franko B, Sterlac) have, likewise, explored their own story/life as a performance. The thesis demonstrates the validity of the four parameters (performer, performance space, devising process, social event) defining a generic approach to the director. A generic perspective on the role of the director would encompass: a historical dimension relative to the reasons for and stages of the 'emergence' of the director; a socio-political analysis concerning the relationship between the director, her/his institutionalisation, and the political realm; and the relationship between performance theory, practice and the contemporary role of the director. Such a generic approach is a new departure in theatre research and might resonate in the study of other collaborative artistic practices.

Wireless power charger for light electric vehicles

Wireless power transmission technology is gaining more and more attentions in city transportation applications due to its commensurate power level and efficiency with conductive power transfer means. In this paper, an inductively coupled wireless charging system for 48V light electric vehicle is proposed. The power stages of the system is evaluated and designed, including the high frequency inverter, the resonant network, full bridge rectifier, and the load matching converter. Small signal modeling and linear control technology is applied to the load matching converter for input voltage control, which effectively controls the wireless power flow. The prototype is built with a dsPIC digital signal controller; the experiments are carried out, and the results reveal nature performances of a series-series resonant inductive power charger in terms of frequency, air-gap length, power flow control, and efficiency issues.

Modeling high-speed network traffic with truncated α-stable processes

It has been reported that high-speed communication network traffic exhibits both long-range dependence (LRD) and burstiness, which posed new challenges in network engineering. While many models have been studied in capturing the traffic LRD, they are not capable of capturing efficiently the traffic impulsiveness. It is desirable to develop a model that can capture both LRD and burstiness. In this letter, we propose a truncated a-stable LRD process model for this purpose, which can characterize both LRD and burstiness accurately. A procedure is developed further to estimate the model parameters from real traffic. Simulations demonstrate that our proposed model has a higher accuracy compared to existing models and is flexible in capturing the characteristics of high-speed network traffic. © 2012 Springer-Verlag GmbH.

A simulation study of service differentiation for the bandwidth request scheme in fixed IEEE 802.16 network

Various flexible mechanisms related to quality of service (QoS) provisioning have been specified for uplink traffic at the medium access control (MAC) layer in the IEEE 802.16 standards. Among the mechanisms, contention based bandwidth request scheme can be used to indicate bandwidth demands to the base station for the non-real-time polling and best-effort services. These two services are used for most applications with unknown traffic characteristics. Due to the diverse QoS requirements of those applications, service differentiation (SD) is anticipated over the contention based bandwidth request scheme. In this paper we investigate the SD with the bandwidth request scheme by means of assigning different channel access parameters and bandwidth allocation priorities at different packets arrival probability. The effectiveness of the differentiation schemes is evaluated by simulations. It is observed that the initial backoff window can be efficient in SD, and if combined with the bandwidth allocation priority, the SD performances will be better.

Simulation of power quality issues in more electric aircraft actuator supplies

To examine the detailed operation of the power distribution network in a future more electric aircraft that employs electric actuation systems, a Micro-Cap SPICE simulation is developed for one of the essential buses. Particular attention is paid to model accurately the most important effects that influence system power quality. Representative system and flight data are used to illustrate the operation of the simulation and to assess the power quality conditions within the network as the flight control surfaces are deployed. The results illustrate the importance of correct cable sizing to ensure stable operation of actuators during transient conditions.

A multi-modular second life hybrid battery energy storage system for utility grid applications

The modern grid system or the smart grid is likely to be populated with multiple distributed energy sources, e.g. wind power, PV power, Plug-in Electric Vehicle (PEV). It will also include a variety of linear and nonlinear loads. The intermittent nature of renewable energies like PV, wind turbine and increased penetration of Electric Vehicle (EV) makes the stable operation of utility grid system challenging. In order to ensure a stable operation of the utility grid system and to support smart grid functionalities such as, fault ride-through, frequency response, reactive power support, and mitigation of power quality issues, an energy storage system (ESS) could play an important role. A fast acting bidirectional energy storage system which can rapidly provide and absorb power and/or VARs for a sufficient time is a potentially valuable tool to support this functionality. Battery energy storage systems (BESS) are one of a range suitable energy storage system because it can provide and absorb power for sufficient time as well as able to respond reasonably fast. Conventional BESS already exist on the grid system are made up primarily of new batteries. The cost of these batteries can be high which makes most BESS an expensive solution. In order to assist moving towards a low carbon economy and to reduce battery cost this work aims to research the opportunities for the re-use of batteries after their primary use in low and ultra-low carbon vehicles (EV/HEV) on the electricity grid system. This research aims to develop a new generation of second life battery energy storage systems (SLBESS) which could interface to the low/medium voltage network to provide necessary grid support in a reliable and in cost-effective manner. The reliability/performance of these batteries is not clear, but is almost certainly worse than a new battery. Manufacturers indicate that a mixture of gradual degradation and sudden failure are both possible and failure mechanisms are likely to be related to how hard the batteries were driven inside the vehicle. There are several figures from a number of sources including the DECC (Department of Energy and Climate Control) and Arup and Cenex reports indicate anything from 70,000 to 2.6 million electric and hybrid vehicles on the road by 2020. Once the vehicle battery has degraded to around 70-80% of its capacity it is considered to be at the end of its first life application. This leaves capacity available for a second life at a much cheaper cost than a new BESS Assuming a battery capability of around 5-18kWhr (MHEV 5kWh - BEV 18kWh battery) and approximate 10 year life span, this equates to a projection of battery storage capability available for second life of >1GWhrs by 2025. Moreover, each vehicle manufacturer has different specifications for battery chemistry, number and arrangement of battery cells, capacity, voltage, size etc. To enable research and investment in this area and to maximize the remaining life of these batteries, one of the design challenges is to combine these hybrid batteries into a grid-tie converter where their different performance characteristics, and parameter variation can be catered for and a hot swapping mechanism is available so that as a battery ends it second life, it can be replaced without affecting the overall system operation. This integration of either single types of batteries with vastly different performance capability or a hybrid battery system to a grid-tie 3 energy storage system is different to currently existing work on battery energy storage systems (BESS) which deals with a single type of battery with common characteristics. This thesis addresses and solves the power electronic design challenges in integrating second life hybrid batteries into a grid-tie energy storage unit for the first time. This study details a suitable multi-modular power electronic converter and its various switching strategies which can integrate widely different batteries to a grid-tie inverter irrespective of their characteristics, voltage levels and reliability. The proposed converter provides a high efficiency, enhanced control flexibility and has the capability to operate in different operational modes from the input to output. Designing an appropriate control system for this kind of hybrid battery storage system is also important because of the variation of battery types, differences in characteristics and different levels of degradations. This thesis proposes a generalised distributed power sharing strategy based on weighting function aims to optimally use a set of hybrid batteries according to their relative characteristics while providing the necessary grid support by distributing the power between the batteries. The strategy is adaptive in nature and varies as the individual battery characteristics change in real time as a result of degradation for example. A suitable bidirectional distributed control strategy or a module independent control technique has been developed corresponding to each mode of operation of the proposed modular converter. Stability is an important consideration in control of all power converters and as such this thesis investigates the control stability of the multi-modular converter in detailed. Many controllers use PI/PID based techniques with fixed control parameters. However, this is not found to be suitable from a stability point-of-view. Issues of control stability using this controller type under one of the operating modes has led to the development of an alternative adaptive and nonlinear Lyapunov based control for the modular power converter. Finally, a detailed simulation and experimental validation of the proposed power converter operation, power sharing strategy, proposed control structures and control stability issue have been undertaken using a grid connected laboratory based multi-modular hybrid battery energy storage system prototype. The experimental validation has demonstrated the feasibility of this new energy storage system operation for use in future grid applications.

Enabling long journeys in electric vehicles:design and demonstration of an infrastructure location model

This research develops a methodology and model formulation which suggests locations for rapid chargers to help assist infrastructure development and enable greater battery electric vehicle (BEV) usage. The model considers the likely travel patterns of BEVs and their subsequent charging demands across a large road network, where no prior candidate site information is required. Using a GIS-based methodology, polygons are constructed which represent the charging demand zones for particular routes across a real-world road network. The use of polygons allows the maximum number of charging combinations to be considered whilst limiting the input intensity needed for the model. Further polygons are added to represent deviation possibilities, meaning that placement of charge points away from the shortest path is possible, given a penalty function. A validation of the model is carried out by assessing the expected demand at current rapid charging locations and comparing to recorded empirical usage data. Results suggest that the developed model provides a good approximation to real world observations, and that for the provision of charging, location matters. The model is also implemented where no prior candidate site information is required. As such, locations are chosen based on the weighted overlay between several different routes where BEV journeys may be expected. In doing so many locations, or types of locations, could be compared against one another and then analysed in relation to siting practicalities, such as cost, land permission and infrastructure availability. Results show that efficient facility location, given numerous siting possibilities across a large road network can be achieved. Slight improvements to the standard greedy adding technique are made by adding combination weightings which aim to reward important long distance routes that require more than one charge to complete.

Impact of electric vehicles on GB electricity demand and associated benefits for system control

This paper investigates the impact that electric vehicle uptake will have on the national electricity demand of Great Britain. Data from the National Travel Survey, and the Coventry and Birmingham Low Emissions Demonstration (CABLED) are used to model an electrical demand profile in a future scenario of significant electric vehicle market penetration. These two methods allow comparison of how conventional cars are currently used, and the resulting electrical demand with simple substitution of energy source, with data showing how electric vehicles are actually being used at present. The report finds that electric vehicles are unlikely to significantly impact electricity demand in GB. The paper also aims to determine whether electric vehicles have the potential to provide ancillary services to the grid operator, and if so, the capacity for such services that would be available. Demand side management, frequency response and Short term Operating Reserve (STOR) are the services considered. The report finds that electric cars are unlikely to provide enough moveable demand peak shedding to be worthwhile. However, it is found that controlling vehicle charging would provide sufficient power control to viably act as frequency response for dispatch by the transmission system operator. This paper concludes that electric vehicles have technical potential to aid management of the transmission network without adding a significant demand burden. © 2013 IEEE.

Powertrain optimisation in a hybrid electric bus

This paper describes the use of a formal optimisation procedure to optimise a plug-in hybrid electric bus using two different case studies to meet two different performance criteria; minimum journey cost and maximum battery life. The approach is to choose a commercially available vehicle and seek to improve its performance by varying key design parameters. Central to this approach is the ability to develop a representative backward facing model of the vehicle in MATLAB/Simulink along with appropriate optimisation objective and penalty functions. The penalty functions being the margin by which a particular design fails to meet the performance specification. The model is validated against data collected from an actual vehicle and is used to estimate the vehicle performance parameters in a model-in-the-loop process within an optimisation routine. For the purposes of this paper, the journey cost/battery life over a drive cycle is optimised whilst other performance indices are met (or exceeded). Among the available optimisation methods, Powell's method and Simulated Annealing are adopted. The results show this method as a valid alternative modelling approach to vehicle powertrain optimisation. © 2012 IEEE.

A new unsupervised convolutional neural network model for Chinese scene text detection

As one of the most popular deep learning models, convolution neural network (CNN) has achieved huge success in image information extraction. Traditionally CNN is trained by supervised learning method with labeled data and used as a classifier by adding a classification layer in the end. Its capability of extracting image features is largely limited due to the difficulty of setting up a large training dataset. In this paper, we propose a new unsupervised learning CNN model, which uses a so-called convolutional sparse auto-encoder (CSAE) algorithm pre-Train the CNN. Instead of using labeled natural images for CNN training, the CSAE algorithm can be used to train the CNN with unlabeled artificial images, which enables easy expansion of training data and unsupervised learning. The CSAE algorithm is especially designed for extracting complex features from specific objects such as Chinese characters. After the features of articficial images are extracted by the CSAE algorithm, the learned parameters are used to initialize the first CNN convolutional layer, and then the CNN model is fine-Trained by scene image patches with a linear classifier. The new CNN model is applied to Chinese scene text detection and is evaluated with a multilingual image dataset, which labels Chinese, English and numerals texts separately. More than 10% detection precision gain is observed over two CNN models.

In situ diagnostics and prognostics of solder fatigue in IGBT modules for electric vehicle drives

This paper proposes an in situ diagnostic and prognostic (D&P) technology to monitor the health condition of insulated gate bipolar transistors (IGBTs) used in EVs with a focus on the IGBTs' solder layer fatigue. IGBTs' thermal impedance and the junction temperature can be used as health indicators for through-life condition monitoring (CM) where the terminal characteristics are measured and the devices' internal temperature-sensitive parameters are employed as temperature sensors to estimate the junction temperature. An auxiliary power supply unit, which can be converted from the battery's 12-V dc supply, provides power to the in situ test circuits and CM data can be stored in the on-board data-logger for further offline analysis. The proposed method is experimentally validated on the developed test circuitry and also compared with finite-element thermoelectrical simulation. The test results from thermal cycling are also compared with acoustic microscope and thermal images. The developed circuitry is proved to be effective to detect solder fatigue while each IGBT in the converter can be examined sequentially during red-light stopping or services. The D&P circuitry can utilize existing on-board hardware and be embedded in the IGBT's gate drive unit.