Thesis (PhD)--Stellenbosch University, 2011. / ENGLISH ABSTRACT: The primary concern of this dissertation will be to understand under what conditions novelty arises within a system. In classical philosophy, the notion of novelty is usually said to arise out of an event. However, the notion of an event often carries with it metaphysical and conservative implications. Therefore, part of the concern of this dissertation is to begin to develop an approach to novelty which is not dependent upon the event. This approach is developed through the insights offered by Critical Complexity and post‐structuralist philosophy. In social science the model of the frame has dominated how to think about the limitations to the context specific nature of knowledge. Instead of the analogy of a frame, this dissertation argues that it is better to adopt the notion of an ‘economy’. This is due to the fact that the notion of an economy allows social scientists to better theorize the relationships which constitute the models they create. The argument for an economy is made by exploring the connections between the work of Jacques Derrida, the complexity theorist Edgar Morin and Georges Bataille. However, when using the notion of an economy, one must always take the excess of this economy into consideration. This excess always feeds back to disrupt the economy from which it is excluded. Using terms developed in complexity theory, this dissertation illustrates how a system adapts to the environment by using this excess. Due to this there can never be a comprehensively modelled complex system because there are always facets of this system which remain hidden to the observer. The work of Alain Badiou, whose central concern is the notion of novelty arising out of an event, is introduced. The implications of depending on the event for novelty to arise are drawn out by discussing the affinities between the work of Derrida and Badiou. In this regard, Derrida’s use of the term ‘event’ much more readily agrees with a complexity informed understanding of the term in contrast to the quasi‐religious definition which Badiou uses. This complexity‐informed understanding of the event illustrates that what the event reveals is simultaneously a dearth and wealth of possibilities yet to be realized. Therefore the event cannot be depended upon to produce novelty. However, the notion of the event must not be discarded too quickly; classical science has traditionally discarded this idea due to its reductive approach. The idea of process opens up an understanding of the radical novelties produced in history to the possibility of the event and to a new understanding of ontology. This dissertation proposes that one can begin to think about radical forms of novelty without the event through the notion of experimentation. This approach allows one to engage with what exists rather than relying upon an event to produce novelty. This argument is made by following Bataille, who argues that through an engagement with non‐utilitarian forms of action, by expending for the sake of expenditure, the world is opened up to possibilities which remain unrealized under the current hegemony. In this light, this dissertation begins to develop a definition of novelty as that which forces a rereading of the system’s history. / AFRIKAANSE OPSOMMING: Hierdie proefskrif onderneem hoofsaaklik om die omstandighede waaronder nuwigheid binne ʼn stelsel ontstaan te verstaan. Daar word in die klassieke filosofie voorgehou dat nuwigheid gewoonlik vanuit ʼn gebeurtenis ontstaan. Die idee van ʼn gebeurtenis hou egter dikwels ongewenste metafisiese en konserwatiewe implikasies in. Hierdie proefskrif onderneem dus om, deels, ʼn benadering tot nuwigheid te ontwikkel wat onafhanklik van die gebeurtenis staan. Hierdie benadering word verder uitgebrei met behulp van insigte vanuit die Kritiese Kompleksiteits‐ en Post‐Strukturalistiese filosofie. Tot onlangs het die model van die raamwerk die wyse waarop daar oor die beperkinge van die konteks‐spesifieke aard van kennis in die sosiale wetenskappe gedink word oorheers. In hierdie proefskrif word voorgehou dat die idee van ʼn ‘ekonomie’ in plaas van die analogie van ʼn raamwerk hier gebruik behoort te word, omdat dit ons sal toelaat om die verhoudings binne die modelle wat deur sosiale wetenskaplikes gebruik word beter te verken. Verder word die moontlike verbande tussen Jacques Derrida , die kompleksiteitsfilosoof Edgar Morin en Georges Bataille teen hierdie agtergrond verken. Wanneer daar van ʼn ekonomie gepraat word, moet die oormaat van die ekonomie altyd in ag geneem word. Hierdie oormaat ontwrig altyd die ekonomie waarby dit uitgesluit word. Om te wys hoe die stelsel van so ʼn oormaat gebruik maak om by sy omgewing aan te pas, sal terminologie wat in die konteks van kompleksiteitsteorie ontwikkel is gebruik word. As gevolg van die oorvloed binne ʼn stelsel sal daar nooit ʼn volledige model van die stelsel ontwikkel kan word nie ‐‐ fasette van die stelsel sal altyd vir die waarnemer verborge bly. Verder sal die werk van Alain Badiou, wie se filosofie rondom die idee van nuwigheid wat uit ʼn gebeurtenis ontstaan gesentreed is, in hierdie verhandeling bespreek word. Die implikasies van die idee dat nuwigheid van die gebeurtenis afhanklik is word uitgelig deur die verwantskappe tussen die werke van Derrida en Badiou te bespreek. Derrida se gebruik van die term ‘gebeurtenis’ dra ʼn noue verwantskap met kompleksiteitsteorie, en dit word teenoor Badiou se amper‐godsdienstige gebruik van die term gestel. Daar word aangevoer dat daar binne ʼn kompleksiteits‐ingeligte verstaan van ʼn gebeurtenis beide ʼn skaarste en ʼn oorvloed van moontlikhede bestaan wat vervul kan word. Daarom kan daar juis nié op die gebeurtenis staatgemaak word om nuwigheid te skep nie. Die idee van die gebeurtenis moet egter nie te gou verwerp word nie. As gevolg van die klassieke wetenskap se reduksionisme is die idee van ʼn gebeurtenis tradisioneel ontken. Daarteenoor ontsluit die idee van ʼn proses die moontlikheid van radikale nuwighede in die geskiedenis as gevolg van ʼn verstaan van die gebeurtenis wat tot ʼn nuwe verstaan van die ontologie lei. Hierdie proefskrif stel dus voor dat ons voortaan aan radikale nuwigheid dink in terme van die denkbeeld van eksperimentering eerder as in terme van die gebeurtenis. Eksperimentering laat ons toe om te werk met wat ons het, eerder as om op ʼn gebeurtenis te moet wag. Na aanleiding van Bataille is die voorstel dat daar deur om te gaan met nieutilitaristiese vorms van optrede nuwe geleenthede vir die wêreld oopgemaak word; geleenthede wat onder die huidige hegemonie ongerealiseerd sal bly. In hierdie verband stel die proefskrif ʼn definisie van nuwigheid voor as dít wat mens dwing om die geskiedenis van ʼn stelsel te herformuleer.

A central goal of theoretical computer science is to characterize the limits of efficient computation in a variety of models. We pursue this research objective in the contexts of communication complexity and computational learning theory. In the former case, one seeks to understand which distributed computations require a significant amount of communication among the parties involved. In the latter case, one aims to rigorously explain why computers cannot master some prediction tasks or learn from past experience. While communication and learning may seem to have little in common, they turn out to be closely related, and much insight into both can be gained by studying them jointly. Such is the approach pursued in this thesis. We answer several fundamental questions in communication complexity and learning theory and in so doing discover new relations between the two topics. A consistent theme in our work is the use of analytic methods to solve the problems at hand, such as approximation theory, Fourier analysis, matrix analysis, and duality. We contribute a novel technique, the pattern matrix method, for proving lower bounds on communication. Using our method, we solve an open problem due to Krause and Pudlák (1997) on the comparative power of two well-studied circuit classes: majority circuits and constant-depth AND/OR/NOT circuits. Next, we prove that the pattern matrix method applies not only to classical communication but also to the more powerful quantum model. In particular, we contribute lower bounds for a new class of quantum communication problems, broadly subsuming the celebrated work by Razborov (2002) who used different techniques. In addition, our method has enabled considerable progress by a number of researchers in the area of multiparty communication. Second, we study unbounded-error communication, a natural model with applications to matrix analysis, circuit complexity, and learning. We obtain essentially optimal lower bounds for all symmetric functions, giving the first strong results for unbounded-error communication in years. Next, we resolve a longstanding open problem due to Babai, Frankl, and Simon (1986) on the comparative power of unbounded-error communication and alternation, showing that [mathematical equation]. The latter result also yields an unconditional, exponential lower bound for learning DNF formulas by a large class of algorithms, which explains why this central problem in computational learning theory remains open after more than 20 years of research. We establish the computational intractability of learning intersections of halfspaces, a major unresolved challenge in computational learning theory. Specifically, we obtain the first exponential, near-optimal lower bounds for the learning complexity of this problem in Kearns’ statistical query model, Valiant’s PAC model (under standard cryptographic assumptions), and various analytic models. We also prove that the intersection of even two halfspaces on {0,1}n cannot be sign-represented by a polynomial of degree less than [Theta](square root of n), which is an exponential improvement on previous lower bounds and solves an open problem due to Klivans (2002). We fully determine the relations and gaps among three key complexity measures of a communication problem: product discrepancy, sign-rank, and discrepancy. As an application, we solve an open problem due to Kushilevitz and Nisan (1997) on distributional complexity under product versus nonproduct distributions, as well as separate the communication classes PPcc and UPPcc due to Babai, Frankl, and Simon (1986). We give interpretations of our results in purely learning-theoretic terms. / text

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Water balance models are important for the characterization of hydrologic systems, to help understand regional scale dynamics, and to identify hydro-climatic trends and systematic biases in data. Because existing models have, to-date, only been tested on data sets of limited spatial representativeness and extent, it has not yet been established that they are capable of reproducing the range of dynamics observed in nature. This dissertation develops systematic strategies to guide selection of water balance models, establish data requirements, estimate parameters, and evaluate performance. Through a series of three papers, these challenges are investigated in the context of monthly water balance modeling across the conterminous United States. The first paper reports on an initial diagnostic iteration to evaluate relevant components of model error, and to examine details of its spatial variability. We find that to conduct a robust model evaluation it is not sufficient to rely upon conventional NSE and/or r^2aggregate statistics of performance; to have reasonable confidence that the model can provide hydrologically consistent simulations, it is also necessary to examine measures of water balance and hydrologic variability. The second paper builds upon the results of the first, and evaluates the suitability of several candidate model structures, focusing specifically snow-free catchments. A diagnostic Maximum-Likelihood model evaluation procedure is developed to incorporate the notion of `Hydrological Consistency' and controls for structural complexity. The results confirm that the evaluation of hydrologic consistency, based on benchmark comparisons and on stringent analysis of residuals, provides a robust basis for guiding model selection. The results reveal strong spatial persistence of certain model structures that needs to be understood in future studies. The third paper focuses on understanding and improving the procedure for constraining model parameters to provide hydrologically consistent results. In particular, it develops a penalty-function based modification of the Mean Squared Error estimation to help ensure proper reproduction of system behaviors by minimizing interaction of error components and by facilitating inclusion of relevant information. The analysis and results provide insight into the identifiability of model parameters, and further our understanding of how performance criteria should be applied during model identification.

Recent decades have seen a surge of landscape concepts in archaeology. Despite strong, growing interest in landscapes, landscape archaeology lacks theoretical and methodological consistency and coherence. To address this problem, I develop a general, integrative framework for landscape archaeology.I argue that landscape concepts have a deep history in anthropological debate. Disagreements between landscape approaches are framed as recapitulations of an ongoing historical dialectic in anthropology. I suggest that fundamental binary oppositions in landscape archaeology can be understood in terms of the epistemological and philosophical distinctions between what Sahlins (1976) has termed cultural logic and practical reason. Optimistically, I offer the working hypothesis that landscape studies may form the synthesis of this entrenched dialectic.I argue that landscape perspectives in archaeology benefit from approaches in geography and ecology, but ultimately artifacts and behavior-based models will need to be built to explain archaeological landscape patterns. Drawing upon behavioral archaeology, I introduce the concepts of archaeological and systemic landscapes and argue that this distinction is critical for making inferences about systemic landscape processes from archaeological landscape patterns. Further, I consider the relevance of scale issues in analyzing landscape patterns and processes.In contradistinction to current approaches that highlight the role of perception and ritual in cognized landscapes, I argue that landscapes are also cognized according to techno-functional categories and suggest that in many cases, how landscapes are cognized is intimately related to how they are used.To model landscapes, I suggest that landscapes are networks and may share some properties with other kinds of biological, ecological, technological, and social networks. I argue that basic properties of landscapes may be allometrically related in manners similar, but potentially distinct from, relationships observed for non-human organisms in physiology and biology. In order to counter notions that human behaviors are either reflexes of environmental conditions or constitutive of environments, I advance the notion of landscape hierarchy. Finally, I explore aspects of systemic and archaeological landscapes relevant to a Class III pedestrian survey I directed in southern Arizona, the Ironwood Forest National Monument survey.

Within the framework of economic constraints and demographic changes which the health care sector is confronted to, the Home Health Care (HHC) which has been created sixty years ago, has known an important growth during this last decade. The main objective of this alternative to the traditional hospitalization consists in solving the problem of hospitals' capacity saturation by allowing earlier discharge of patients from hospital or by avoiding their admission while improving or maintaining the medical, psychological and social welfare of these patients. In this thesis, we are interested in the operations management within the HHC structures. In the first part of this thesis, we develop a qualitative analysis of the operations management in the HHC context. More specifically, we identify the complexity factors that operations management has to face up within this type of structures. For each complexity factor, we discuss how it can affect the organization of the care delivery. These factors pertain to the diversity of the services proposed, the location of care delivery, the uncertainty sources, etc. Thereafter, we survey operations management based models proposed in the literature within the HHC context. Based on this literature review, we identify several emerging issues, relevant from an organizational point of view, that have not been studied in the literature and thus represent unexplored opportunities for operations management researchers. In the second part of this thesis, we are interested in the partitioning of the area where the HCC structure operates into districts. This districting approach fits the policies of improvement of the quality of care delivered to patients and the working conditions of care givers as well as costs' reduction. We begin by proposing a classification of the different criteria that may be considered in the districting problem. We then propose two mathematical formulations for the HHC districting problem for which we consider criteria such as the workload balance, compactness, compatibility and indivisibility of basic units. After that, we present a numerical analysis of the computational experiments carried out on randomly generated instances to validate these two models. We also present two possible exploitations of these models and propose two extensions to these basic formulations. After formulating the problem with a static approach, we also develop a dynamic extension which allows the integration of the different variations that can be observed within the activities of an HHC structure from period to period. We then introduce a new partitioning criterion that concerns the continuity of care evaluated on the basis of two sub-criteria. Depending on the preferences of the decision-makers concerning the sub-criteria related to the continuity of care in the districting problem, we then distinguish three scenarios for which we propose the associated mathematical formulations.

We explore the possibility of automating <i>NP</i>-hardness reductions. We motivate the problem from an artificial intelligence perspective, then propose the use of second-order existential (<i>SO</i>&#8707;) logic as representation language for decision problems. Building upon the theoretical framework of J. Antonio Medina, we explore the possibility of implementing seven syntactic operators. Each operator transforms <i>SO</i>&#8707; sentences in a way that preserves <i>NP</i>-completeness. We subsequently propose a program which implements these operators. We discuss a number of theoretical and practical barriers to this task. We prove that determining whether two <i>SO</i>&#8707; sentences are equivalent is as hard as GRAPH ISOMORPHISM, and prove that determining whether an arbitrary <i>SO</i>&#8707; sentence represents an <i>NP</i>-complete problem is undecidable.

Nature of the inquiry: My research inquiry investigated how qualities of personal interaction shape and affect the promotion of research utilisation for quality improvement in the US healthcare sector. The research investigated my own professional practice of consulting, teaching, and research regarding the improvement of healthcare practices and outcomes. Efforts to improve the quality of healthcare services are often difficult to realise and sustain. The quality improvement movement in the USA and elsewhere has not conducted much self-examination of its own processes for sources of these perennially problematic results. Relevance: The quality of healthcare services can be readily understood as having consequences of life or death, wellness or suffering. Healthcare expenditures in the USA are estimated at 16% of GDP and over 9% in the UK. Improving healthcare quality improvement efforts is a matter of profound human and social significance. Approach: The DMan research methodology is a reflexively aware process conducted as a cohort and as small learning groups of researchers during the three-year programme. The research inquiry used the complex responsive process of relating theory of learning as emergent changes of meaning or, equivalently, knowledge. As a social science of qualities, it uses the qualities of human interaction as the unit of analysis. The research utilised an interdisciplinary approach drawing upon: healthcare quality improvement literature; organizational discourse studies; research on strategy as practice; performance management; communications theories; the theory of mindful learning; interpersonal neurobiology; figurational sociology; and American pragmatist philosophy. The methodology employs a mindful reflexivity research strategy related to concepts from mindful learning and social neuroscience literature. Central methods included iterative peer and supervisor debriefing and iterative reflexive narrative practice. Findings: A contribution is made to the healthcare literature by describing how ordinary qualities of social coordination dynamics affect the promoters of healthcare research, not just potential users of research. A contribution is made to professional practice by providing a new perspective from which to analyse the sources of performance challenges prevalent in healthcare quality improvement efforts. The research findings indicate how applications of substantial organisational and social resources to promote research utilisation in the US health sector can be co-opted and dissipated away from ostensive substantive objectives. This occurs by research promoters‟ organizational discourse efforts to favourably shape power relating and other qualities of interaction of improvement initiatives. These efforts restrict the emergence of learning about the promoted changes.

The central goal of this thesis is to provide additional criteria towards implementing open-ended evolution in an artificial system. Methods inspired by biological evolution are frequently applied to generate autonomous agents too complex to design by hand. Despite substantial progress in the area of evolutionary computation, additional efforts are needed to identify a coherent set of requirements for a system capable of exhibiting open-ended evolutionary dynamics. The thesis provides an extensive discussion of existing models and of the major considerations for designing a computational model of evolution by natural selection. Thus, the work in this thesis constitutes a further step towards determining the requirements for such a system and introduces a concrete implementation of an artificial evolution system to evaluate the developed suggestions. The proposed system improves upon existing models with respect to easy interpretability of agent behaviour, high structural freedom, and a low-level sensor and effector model to allow numerous long-term evolutionary gradients. In a series of experiments, the evolutionary dynamics of the system are examined against the set objectives and, where appropriate, compared with existing systems. Typical agent behaviours are introduced to convey a general overview of the system dynamics. These behaviours are related to properties of the respective agent populations and their evolved morphologies. It is shown that an intuitive classification of observed behaviours coincides with a more formal classification based on morphology. The evolutionary dynamics of the system are evaluated and shown to be unbounded according to the classification provided by Bedau and Packard’s measures of evolutionary activity. Further, it is analysed how observed behavioural complexity relates to the complexity of the agent-side mechanisms subserving these behaviours. It is shown that for the concrete definition of complexity applied, the average complexity continually increases for extended periods of evolutionary time. In combination, these two findings show how the observed behaviours are the result of an ongoing and lasting adaptive evolutionary process as opposed to being artifacts of the seeding process. Finally, the effect of variation in the system on the diversity of evolved behaviour is investigated. It is shown that coupling individual survival and reproductive success can restrict the available evolutionary trajectories in more than the trivial sense of removing another dimension, and conversely, decoupling individual survival from reproductive success can increase the number of evolutionary trajectories. The effect of different reproductive mechanisms is contrasted with that of variation in environmental conditions. The diversity of evolved strategies turns out to be sensitive to the reproductive mechanism while being remarkably robust to the variation of environmental conditions. These findings emphasize the importance of being explicit about the abstractions and assumptions underlying an artificial evolution system, particularly if the system is intended to model aspects of biological evolution.

My research focuses on the experience of policy development and implementation. It draws on my involvement in a government policy taskforce, the development of an organisation’s strategy to the taskforce’s recommendations and the commissioning of frontline services. The research material is my personal experience contained in a number of narrative accounts of important happenings. These are then used as a basis to engage with literature and conversation with practitioners, academics and fellow researchers. It is from this iterative process that the argument develops. The approach is therefore qualitative and reflexive in nature. I have argued against the traditional separation between the content of research and methodology. This is on the basis that human experience does not distinguish between the two as we make sense of new emerging situations. The research has been heavily influenced by analogies drawn from complexity sciences as a way of increasing our understanding of ongoing human interaction, namely complex responsive processes of relating (Stacey et al, 2000). By paying careful attention to the experience of policy development and implementation over an extended period of time I am illuminating that the development of policy can often be seen in literature and in the techniques people use as an activity that is isolated from the work of frontline staff. For example, a policy group is formed, policy or a strategy is drafted and the work is then seen to be done. This can be demonstrated by paying attention to the modus operandi of how policy and strategy groups work and how performance criteria are established. When it comes to frontline practice, policy is often silent to the multitude of unfolding interconnected possibilities that present themselves to practitioners as they seek to go about their activities. The way that policy is often presented implies that there is linearity from policy to implementation. Drawing on Elias’s notion of Involvement and Detachment (1987) I am highlighting a paradoxical relationship between policy and implementation. In introducing the notion of paradox, there is a “vitality” that is required to prevent a collapse to one of the two ends of a continuum; for example a conscious or unconscious rejection of policy in favour of embracing frontline practice, or an over reliance on policy to blindly drive through organisational change. In spending three years looking at the policy and implementation I argue that it is more helpful to consider policy and implementation as a “flow”, rather than a series of discrete activities that are seen to be completed before moving to the next policy area. In looking at policy as something that occurs over a span of time (as opposed to an isolated bounded activity) there is an opportunity to prevent the collapse of the paradox outlined above. By accepting the concept of paradox and considering policy from a temporal perspective, rather than one that is a spatially bound system, the issue of policymaking practice can be considered. There are books and management experts that recommend that managers should “walk the walk”, and get closer to frontline activity. My research has sought to add clarity here, arguing for an experiential and temporal form of reflexivity of practice (as opposed to reflective practice). In this context working and being present with frontline practitioners, paying very careful attention to the experience of the unfolding contingent nature of activity influences the practice of policy making. This is a different experience from simply being present, and being seen to be present. It would be ironic for my research to be converted into a policy document with key elements extracted and condensed into bullet points to be applied like a rule. Instead my research is best kept alive in evoking stories and reminiscences between people as they make sense of their experience of policymaking and implementation together.