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.

Back to the local? Recalibrating the regional tier of governance in England

By contrast to the far-reaching devolution settlements elsewhere in the UK, political agreement on the governance of England outside London remains unsettled. There is cross- party consensus on the need to 'decentre down' authority to regions and localities, but limited agreement on how this should be achieved. This paper explores the welter of initiatives adopted by the recent Labour government that were ostensibly designed to make the meso-level of governance more coherent, accountable and responsive to meeting territorial priorities. Second, it explores the current Conservative-Liberal Democrat Coalition's programme of reform that involves the elimination of Labour's regional institutional architecture and is intended to restore powers to local government and communities and promote local authority co-operation around sub-regions. Labour's reforms were ineffective in achieving any substantial transfer of authority away from Whitehall and, given the Coalition's plans to cut public expenditure, the likelihood of any significant recalibration in central-local relations also appears improbable. © 2012 Copyright Taylor and Francis Group, LLC.

[Review of] Ivo Mijnssen, The Quest for an Ideal Youth in Putin’s Russia I. Back to Our Future! History, Modernity and Patriotism According to Nashi, 2005–2012. Soviet and Post-Soviet Politics and Society, Stuttgart: Ibidem Verlag, 2012, 202pp., e 34.90 p/b

THE YOUTH MOVEMENT NASHI (OURS) WAS FOUNDED IN THE SPRING of 2005 against the backdrop of Ukraine’s ‘Orange Revolution’. Its aim was to stabilise Russia’s political system and take back the streets from opposition demonstrators. Personally loyal to Putin and taking its ideological orientation from Surkov’s concept of ‘sovereign democracy’, Nashi has sought to turn the tide on ‘defeatism’ and develop Russian youth into a patriotic new elite that ‘believes in the future of Russia’ (p. 15). Combining a wealth of empirical detail and the application of insights from discourse theory, Ivo Mijnssen analyses the organisation’s development between 2005 and 2012. His analysis focuses on three key moments—the organisation’s foundation, the apogee of its mobilisation around the Bronze Soldier dispute with Estonia, and the 2010 Seliger youth camp—to help understand Nashi’s organisation, purpose and ideational outlook as well as the limitations and challenges it faces. As such,the book is insightful both for those with an interest in post-Soviet Russian youth culture, and for scholars seeking a rounded understanding of the Kremlin’s initiatives to return a sense of identity and purpose to Russian national life.The first chapter, ‘Background and Context’, outlines the conceptual toolkit provided by Ernesto Laclau and Chantal Mouffe to help make sense of developments on the terrain of identity politics. In their terms, since the collapse of the Soviet Union, Russia has experienced acute dislocation of its identity. With the tangible loss of great power status, Russian realities have become unfixed from a discourse enabling national life to be constructed, albeit inherently contingently, as meaningful. The lack of a Gramscian hegemonic discourse to provide a unifying national idea was securitised as an existential threat demanding special measures. Accordingly, the identification of those who are ‘notUs’ has been a recurrent theme of Nashi’s discourse and activity. With the victory in World War II held up as a foundational moment, a constitutive other is found in the notion of ‘unusual fascists’. This notion includes not just neo-Nazis, but reflects a chain of equivalence that expands to include a range of perceived enemies of Putin’s consolidation project such as oligarchs and pro-Western liberals.The empirical background is provided by the second chapter, ‘Russia’s Youth, the Orange Revolution, and Nashi’, which traces the emergence of Nashi amid the climate of political instability of 2004 and 2005. A particularly note-worthy aspect of Mijnssen’s work is the inclusion of citations from his interviews with Nashicommissars; the youth movement’s cadres. Although relatively few in number, such insider conversations provide insight into the ethos of Nashi’s organisation and the outlook of those who have pledged their involvement. Besides the discussion of Nashi’s manifesto, the reader thus gains insight into the motivations of some participants and behind-the-scenes details of Nashi’s activities in response to the perceived threat of anti-government protests. The third chapter, ‘Nashi’s Bronze Soldier’, charts Nashi’s role in elevating the removal of a World War II monument from downtown Tallinn into an international dispute over the interpretation of history. The events subsequent to this securitisation of memory are charted in detail, concluding that Nashi’s activities were ultimately unsuccessful as their demands received little official support.The fourth chapter, ‘Seliger: The Foundry of Modernisation’, presents a distinctive feature of Mijnssen’s study, namely his ethnographic account as a participant observer in the Youth International Forum at Seliger. In the early years of the camp (2005–2007), Russian participants received extensive training, including master classes in ‘methods of forestalling mass unrest’ (p. 131), and the camp served to foster a sense of group identity and purpose among activists. After 2009 the event was no longer officially run as a Nashi camp, and its role became that of a forum for the exchange of ideas about innovation, although camp spirit remained a central feature. In 2010 the camp welcomed international attendees for the first time. As one of about 700 international participants in that year the author provides a fascinating account based on fieldwork diaries.Despite the polemical nature of the topic, Mijnssen’s analysis remains even-handed, exemplified in his balanced assessment of the Seliger experience. While he details the frustrations and disappointments of the international participants with regard to the unaccustomed strict camp discipline, organisational and communication failures, and the controlled format of many discussions,he does not neglect to note the camp’s successes in generating a gratifying collective dynamic between the participants, even among the international attendees who spent only a week there.In addition to the useful bibliography, the book is back-ended by two appendices, which provide the reader with important Russian-language primary source materials. The first is Nashi’s ‘Unusual Fascism’ (Neobyknovennyi fashizm) brochure, and the second is the booklet entitled ‘Some Uncomfortable Questions to the Russian Authorities’ (Neskol’ko neudobnykh voprosov rossiiskoivlasti) which was provided to the Seliger 2010 instructors to guide them in responding to probing questions from foreign participants. Given that these are not readily publicly available even now, they constitute a useful resource from the historical perspective.

Adaptive back-propagation in on-line learning of multilayer networks

An adaptive back-propagation algorithm is studied and compared with gradient descent (standard back-propagation) for on-line learning in two-layer neural networks with an arbitrary number of hidden units. Within a statistical mechanics framework, both numerical studies and a rigorous analysis show that the adaptive back-propagation method results in faster training by breaking the symmetry between hidden units more efficiently and by providing faster convergence to optimal generalization than gradient descent.

On-line learning with adaptive back-propagation in two-layer networks

An adaptive back-propagation algorithm parameterized by an inverse temperature 1/T is studied and compared with gradient descent (standard back-propagation) for on-line learning in two-layer neural networks with an arbitrary number of hidden units. Within a statistical mechanics framework, we analyse these learning algorithms in both the symmetric and the convergence phase for finite learning rates in the case of uncorrelated teachers of similar but arbitrary length T. These analyses show that adaptive back-propagation results generally in faster training by breaking the symmetry between hidden units more efficiently and by providing faster convergence to optimal generalization than gradient descent.

Lay perceptions of type 2 diabetes in Scotland:bringing health services back in

The growing prevalence of type 2 diabetes is placing Scottish health services under considerable strain. Consequently, diabetes services are undergoing a major process of reorganisation, including the devolvement of routine diabetes care/diabetic review from secondary to primary healthcare settings. This qualitative study was devised to explore newly diagnosed type 2 diabetes patients' perceptions of their disease and the health services they receive at a time when this restructuring of services is taking place. The sample comprised 40 patients resident in Lothian, Scotland, who had diverse experiences of services, some receiving GP-based care only, others having varying contact with hospital diabetes clinics. In-depth interviews were undertaken with patients, three times at six monthly intervals over 1 year, enabling their experiences to be tracked at critical junctures during the post-diagnostic period. Disease perceptions and health service delivery were found to be mutually informing and effecting. Not only did (different types of) health service delivery influence the ways in which patients thought about and self-managed their disease, over time patients' disease perceptions also informed their expectations of, and preferences for, diabetes services. We thus argue that there is a need for a reconceptualisation within the medical social sciences to take into account the context of healthcare and the economic/policy factors that inform health service delivery when looking at patients' disease perceptions. We also discuss the logistical and ethical challenges of drawing upon patients' perspectives, preferences and views in the design and delivery of future health services. © 2004 Elsevier Ltd. All rights reserved.

Back from the future:the second chance in the past of aller + infinitive

Typological studies (Bybee et al. 1994, Dahl 2000, Bourdin 2008 among many others) have shown a tendency for spatial elements (such as movement verbs) to grammaticalise into temporal expressions. The periphrasis made of aller + infinitive has been very productive in Romance languages. If in French, Spanish or Portuguese, it refers to future, it refers to a simple past in Catalan. fr.: je vais aller au cinéma esp.: voy a ir al cine pt. Vou ira o cine cat.: vaig anar al cine Barceló & Bres (2005:168) indicate that, In French, «vers le XVIème siècle, […] la périphrase a brièvement fonctionné comme un temps du passé (alors même que l’emploi comme temps du futur émergeait)»: (1) Sur ces propos, firent leur accord et, en regardant le lieu le plus propre pour faire cette belle œuvre, elle va dire qu’elle n’en savait point de meilleure ni plus loin de tout soupçon, qu’une petite maison qui était dedans le parc, où il y avait chambre et lit tout à propos. (Marguerite de Navarre, L’Heptaméron) The future value took over so much so that Damourette & Pichon (1911-1936 :117) claimed the past value had disappeared»: Un second tour, encore plus aberrant, n’a plus, que nous sachions, aucune position en pays d’Oui. Nous voulons parler de l’expression d’un passé au moyen de l’auxiliaire aller, suivi de l’infinitif. Ce tour a eu une grande fortune dans le provençal ancien et le catalan […] En français, on n’en trouve que des traces, notamment du XIVe au XVIe siècles . Ex.:[…] Adoncques s’arrêtèrent le conte et Raimondin soubz un grand arbre ; lors va dire le conte à Raimondin: […]. Et Raimondin va lui dire : Sire, ce qu’il vous plaira. That allegedly extinct use is nonetheless alive and kicking in Contemporary French. Larreya (2005:349)notes that it is « très courant dans les récits – en particulier dans les récits oraux» and it is also found in newspaper language as shown by this except from an obituary for Loulou Gasté (Le Monde 1995): (2) Celle-ci se déroule aux Editions Micro, où il a un bureau. Séduit par la jeune interprète, il commence à lui écrire des chansons sur mesure et leur complicité va mettre cinq ans à se transformer en amour. Au début de leur rencontre, Loulou est neurasthénique parce qu’il vient de divorcer et la future Line, exclusivement préoccupée par son métier, ne songe à rien d’autre. Line et Loulou vont rattraper le temps perdu et créer ensemble un millier de petites chansons dont la plupart sont devenues immortelles. Jusqu’à ces derniers mois, il ne va pas se passer une journée sans que Loulou s’empare de sa guitare pour créer un refrain. Would we be witnessing a linguistic resurrection? The same structure seems therefore to have grammaticalised in diverging and even diametrically opposite ways in different Romance languages. In this talk, we shall try to explain how the phrase aller + infinitive is able to function both as a future and a past. We will especially concentrate on the case of contemporary French where, while the future interpretation has obtained the status of tense as futur proche or périphrastique, a past interpretation is now commonplace. Our reflection will be supported by a personal corpus of authentic examples.

A constructive learning algorithm based on back-propagation

There are been a resurgence of interest in the neural networks field in recent years, provoked in part by the discovery of the properties of multi-layer networks. This interest has in turn raised questions about the possibility of making neural network behaviour more adaptive by automating some of the processes involved. Prior to these particular questions, the process of determining the parameters and network architecture required to solve a given problem had been a time consuming activity. A number of researchers have attempted to address these issues by automating these processes, concentrating in particular on the dynamic selection of an appropriate network architecture.The work presented here specifically explores the area of automatic architecture selection; it focuses upon the design and implementation of a dynamic algorithm based on the Back-Propagation learning algorithm. The algorithm constructs a single hidden layer as the learning process proceeds using individual pattern error as the basis of unit insertion. This algorithm is applied to several problems of differing type and complexity and is found to produce near minimal architectures that are shown to have a high level of generalisation ability.

Compensation of intra-channel nonlinear fibre impairments using simplified digital back-propagation algorithm

We investigate a digital back-propagation simplification method to enable computationally-efficient digital nonlinearity compensation for a coherently-detected 112 Gb/s polarization multiplexed quadrature phase shifted keying transmission over a 1,600 km link (20x80km) with no inline compensation. Through numerical simulation, we report up to 80% reduction in required back-propagation steps to perform nonlinear compensation, in comparison to the standard back-propagation algorithm. This method takes into account the correlation between adjacent symbols at a given instant using a weighted-average approach, and optimization of the position of nonlinear compensator stage to enable practical digital back-propagation.

Impact of longitudinal power budget in coherent transmission systems employing digital back-propagation

We report the impact of longitudinal signal power profile on the transmission performance of coherently-detected 112 Gb/s m-ary polarization multiplexed quadrature amplitude modulation system after compensation of deterministic nonlinear fibre impairments. Performance improvements up to 0.6 dB (Q(eff)) are reported for a non-uniform transmission link power profile. Further investigation reveals that the evolution of the transmission performance with power profile management is fully consistent with the parametric amplification of the amplified spontaneous emission by the signal through four-wave mixing. In particular, for a non-dispersion managed system, a single-step increment of 4 dB in the amplifier gain, with respect to a uniform gain profile, at similar to 2/3(rd) of the total reach considerably improves the transmission performance for all the formats studied. In contrary a negative-step profile, emulating a failure (gain decrease or loss increase), significantly degrades the bit-error rate.

Polarization multiplexed 16QAM transmission employing modified digital back-propagation

We experimentally demonstrate performance enhancements enabled by weighted digital back propagation method for 28 Gbaud PM-16QAM transmission systems, over a 250 km ultra-large area fibre, using only one back-propagation step for the entire link, enabling up to 3 dB improvement in power tolerance with respect to linear compensation only. We observe that this is roughly the same improvement that can be obtained with the conventional, computationally heavy, non-weighted digital back propagation compensation with one step per span. As a further benchmark, we analyze performance improvement as a function of number of steps, and show that the performance improvement saturates at approximately 20 steps per span, at which a 5 dB improvement in power tolerance is obtained with respect to linear compensation only. Furthermore, we show that coarse-step self-phase modulation compensation is inefficient in wavelength division multiplexed transmission.