Thesis (MPhil)--Stellenbosch University, 2014. / ENGLISH ABSTRACT: The dehumanising of human beings which often underpins western medicine lead to this study. Moreover a predominant mechanistic and reductionist view of a human being necessitated a philosophical investigation to revisit the stance. It is argued that western medicine is based upon uncritical assumptions about humans as a result of the dualism and mechanistic views of Descartes. The philosophy of Merleau-Ponty transcended dualism by his emphasis on the bodylines of a human being situated in his life world. Complexity thinking concurs with the above-mentioned view, however, takes the argument further by focusing on the importance of continuous interactions and relations between the whole and the parts. Interdependent aspects of our being in the world constitute our humanness, such as our human relations between family members, friends, that which we experience, ponder, feel, and believe. Our unique experience of disease often goes hand in hand with a deep-seated sub-conscious longing for meaning. According to complexity theory being ill is not a static condition, but rather an imbalance as a result of various dynamic interactions between many spheres of human life. Multiple causality due to various dynamic interactions and self-organisation should replace simplistic views of mechanical cause and effect in this regard. Medical training models should not employ reductionism as if humans are machines comprising of separate body parts. An organic view of the uniqueness of each evolving human being should replace obsolete reductionist and mechanistic views of healing.The essence of being human is embedded in a tapestry of dynamic relations. / AFRIKAANSE OPSOMMING: Die dehumanisering van die mens in hedendaagse westerse geneeskunde het aanleiding gegee tot hierdie studie. Verder het die meganistiese, reduksionistiese mensbeeld ‘n filosofiese herbesinning genoodsaak. Daar word geargumenteer dat westerse geneeskunde gebaseer is op onkritiese aannames afkomstig van onder andere Descartes se dualistiese antropologie en die meganistiese siening van die mens. Merleau-Ponty se wysgerige antropologie het die dualisme getransendeer deur sy filosofie van die mens as liggaamlikheid gesitueerd in sy leefwêreld. Kompleksiteitsdenke stem hiermee ooreen, maar voer die argument verder in die opsig dat dit die belangrikheid van relasies en voortdurende wisselwerking tussen die geheel en dele beklemtoon. Interafhanklike aspekte van dit wat ons mens maak, ontstaan as gevolg van relasies tussen ons leefwêreld, ons familie, vriende, tussen dit waaraan ons dink, wat ons voel, ervaar en glo. Ons siekte ervaring gaan meestal gepaard met ‘n diepgewortelde voorbewustelike soeke na sin en betekenis. Die kompleksiteitsperspektief beskou siekwees nie as ‘n statiese toestand wat teenoor gesondwees staan nie, maar eerder ‘n wanbalans in dinamiese interaksies van verskeie sfere van menswees. Enkelvoudige kousaal-meganiese oorsaak en gevolg moet plek maak vir veelvuldige kousaliteit wat geleë is in talle dinamiese interaksies en selforganisering. Mediese opleidingsmodelle behoort die mens nie te objektiveer tot aparte organe, soos die van ‘n masjien nie. Die verontmensliking van die masjien gedrewe model van genesing behoort plek te maak vir ‘n meer organiese siening van die mens wat rekening hou met die unieke menslikheid van die mens. Menslikheid impliseer ‘n tapisserie van relasies.

Thesis (PhD)--Stellenbosch University, 2011. / ENGLISH ABSTRACT: Globalisation, rapid changes in technology, and demographic trends are all important factors that contribute to conditions that require adaptive capacity in military organisations. The context of a majority of military operations is often asymmetric with blurred boundaries, and military organisations are expected to master a wide range of operations from humanitarian disaster relief to more regular warlike situations in a joint- and multinational framework. The complexity of the challenges facing military leaders in contemporary and future operations makes it relevant to develop a meta-competency model for leadership in complex military systems, which is the main purpose of this dissertation. A Complexity Approach represents a shift from a set of conservative laws to a perception of the world as an open and highly dynamic system, and some characterise complexity as a bridge between modernism on the one hand and post-modernism on the other. Complexity and complex systems have a number of characteristics, some of them being a large number of short-ranged interactions that are dynamic, non-linear and fairly rich. Another significant feature of complexity is the emphasis on emergent patterns that are codetermined through a dynamic process between the history of the system and the interaction with its local environment. Leadership in complex systems might be described by the dynamics of emergence, not merely by incremental influence, and increasingly considered to be a collective social phenomenon. A complexity-oriented leader acts as an enabler of a rich identity interacting in richly constrained play of difference, facilitating “bounded” individual and systemic adaptive capacity. The reigning paradigm in military organisations, however, are closely linked to an autocratic and bureaucratic structure and a fundamental quest for control, equilibrium and stability, all of which are deeply embedded in Newtonian Principles of linearity, reductionism and determinism. The investigation of empirical research on Norwegian Military Officers and the Norwegian Armed Forces reveal a considerable amount of homogenous force substantiating stability and control, at the same time as complexity and uncertainty are acknowledged. This dissertation argues that the definition of competencies as “an underlying characteristic of an individual that is causally related to effective and/or superior performance in a job or situation”, is not suitable for a complexity understanding and proposes competencies to be defined as “interconnected underlying characteristics of an individual or system, which through a dynamic and non-linear process of interaction between local agents and the environment contribute to the emergence of identifiable or unidentifiable patterns of individual or systemic behaviour”. Based on a synthesis of a non-empirical literature study, empirical research and a modelbuilding study, this dissertation suggests that heterogeneity of degree, androgynousity, cognitive flexibility, ethical reasoning, cross-cultural competence, intuition, identity and courage, are necessary meta-competencies for leadership in complex military systems. It is further argued that these meta-competencies must be interpreted as interconnected and interdependent, and the metaphor of a cloud is therefore presented as a suitable image of the intricate dynamics of complexity. / AFRIKAANSE OPSOMMING: Globalisering, vinnige veranderinge in tegnologie en demografiese tendense is belangrike faktore wat bydra tot toestande wat aanpassingsvermoë in militêre organisasies vereis. Die konteks waarin ’n meerderheid militêre operasies hul bevind is dikwels asimmetries met onduidelike grense, en daar word van militêre organisasies verwag om ’n wye verskeidenheid krygsverrigtinge van humanitêre rampverligting tot meer gereelde oorlogsugtige omstandighede in ’n gesamentlike en multinasionale kader te bemeester. Die kompleksiteit van die uitdagings waarvoor militêre leiers te staan kom in huidige en toekomstige krygsverrigtinge is dit gepas om ’n meta-bevoegdheidsmodel vir leierskap in komplekse militêre stelsels te ontwikkel, wat die belangrikste doel van hierdie tesis is. ’n Kompleksiteitbenadering verteenwoordig ’n verskuiwing van ’n stel konserwatiewe wette na ’n waarneming van die wêreld as ’n oop en hoogsdinamiese stelsel, en kompleksiteit word soms gekenmerk as ’n brug tussen modernisme aan die een kant en die post-modernisme aan die ander. Kompleksiteit en komplekse stelsels het ’n aantal kenmerke, waarvan sommige van hulle ’n groot aantal kortafstandinteraksies wat dinamiese, nie-lineêre en redelik ryk is. Nog ’n belangrike kenmerk van kompleksiteit is die klem op die ontluikende patrone wat vasgestel word deur middel van beide ’n dinamiese proses tussen die geskiedenis van die stelsel en die interaksie met die plaaslike omgewing. Leierskap in komplekse stelsels kan beskryf word deur die dinamika van verskyning, nie net deur inkrementele invloed nie, en al hoe meer beskou as ’n kollektiewe sosiale verskynsel. ’n Kompleksiteitgeoriënteerde leier dien as ’n instaatsteller van ’n ryk identiteit wat wisselwerking uitoefen in streng beperkte verskilspel, wat “begrensde” individuele en sistemiese aanpassingsvermoë fasiliteer. Die huidige paradigma in die militêre organisasies word egter nou gekoppel aan ’n outokratiese en burokratiese struktuur, en ’n fundamentele soektog vir beheer, ewewig en stabiliteit, waarvan almal diep in Newtoniaanse Beginsels van lineariteit, reduksionisme en determinisme vasgelê is. Die ondersoek van empiriese navorsing oor die Noorse Militêre Offisiere en die Noorse Weermag openbaar ’n aansienlike aantal homogene mag wat stabiliteit en beheer staaf, terselfdertyd as wat kompleksiteit en onsekerheid erken word. Hierdie tesis is van mening dat die definisie van vaardighede as “’n onderliggende eienskap van ’n individu wat oorsaaklik verwant is aan doeltreffende en/of superieure prestasie in ’n beroep of situasie”, nie geskik is vir ’n kompleksiteitbegrip nie en stel voor dat vaardighede gedefinieer word as “onderling verbinde onderliggende eienskappe van ’n individu of stelsel, wat deur middel van ’n dinamiese en nie-lineêre proses van interaksie tussen plaaslike agente en die omgewing bydra tot die verskyning van identifiseerbare of nie-identifiseerbare patrone van individuele of sistemiese gedrag”. Gebaseer op ’n sintese van ’n nie-empiriese literatuurstudie, empiriese navorsing en ’n bou van modelle studie, stel hierdie tesis voor dat die heterogeniteit van graad, androgienisme, kognitiewe buigsaamheid, etiese beredenering, kruis-kulturele bevoegdheid, intuïsie, identiteit en moed, nodige meta-vaardighede vir leierskap in komplekse militêre stelsels is. Dit voer verder aan dat hierdie meta-vaardighede vertolk moet word as onderling verbinde en onderling afhanklik is, en die metafoor van ’n wolk word dus voorgestel as ’n geskikte beeld van die ingewikkelde dinamika van kompleksiteit.

The purpose of this research work is to demonstrate the feasibility of creating a quick response decision platform for middle management in industry. It utilises the strengths of current, but more importantly creates a leap forward in the theory and practice of Supervisory and Data Acquisition (SCADA) systems and Discrete Event Simulation and Modelling (DESM). The proposed research platform uses real-time data and creates an automatic platform for real-time and predictive system analysis, giving current and ahead of time information on the performance of the system in an efficient manner. Data acquisition as the backend connection of data integration system to the shop floor faces both hardware and software challenges for coping with large scale real-time data collection. Limited scope of SCADA systems does not make them suitable candidates for this. Cost effectiveness, complexity, and efficiency-orientation of proprietary solutions leave space for more challenge. A Flexible Data Input Layer Architecture (FDILA) is proposed to address generic data integration platform so a multitude of data sources can be connected to the data processing unit. The efficiency of the proposed integration architecture lies in decentralising and distributing services between different layers. A novel Sensitivity Analysis (SA) method called EvenTracker is proposed as an effective tool to measure the importance and priority of inputs to the system. The EvenTracker method is introduced to deal with the complexity systems in real-time. The approach takes advantage of event-based definition of data involved in process flow. The underpinning logic behind EvenTracker SA method is capturing the cause-effect relationships between triggers (input variables) and events (output variables) at a specified period of time determined by an expert. The approach does not require estimating data distribution of any kind. Neither the performance model requires execution beyond the real-time. The proposed EvenTracker sensitivity analysis method has the lowest computational complexity compared with other popular sensitivity analysis methods. For proof of concept, a three tier data integration system was designed and developed by using National Instruments’ LabVIEW programming language, Rockwell Automation’s Arena simulation and modelling software, and OPC data communication software. A laboratory-based conveyor system with 29 sensors was installed to simulate a typical shop floor production line. In addition, EvenTracker SA method has been implemented on the data extracted from 28 sensors of one manufacturing line in a real factory. The experiment has resulted 14% of the input variables to be unimportant for evaluation of model outputs. The method proved a time efficiency gain of 52% on the analysis of filtered system when unimportant input variables were not sampled anymore. The EvenTracker SA method compared to Entropy-based SA technique, as the only other method that can be used for real-time purposes, is quicker, more accurate and less computationally burdensome. Additionally, theoretic estimation of computational complexity of SA methods based on both structural complexity and energy-time analysis resulted in favour of the efficiency of the proposed EvenTracker SA method. Both laboratory and factory-based experiments demonstrated flexibility and efficiency of the proposed solution.

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

No description available.

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.