Мультиагентный метод оптимизации с адаптивными параметрами

Исследован мультиагентный подход к оптимизации многомерных нелинейных функций. Разработан мультиагентный метод оптимизации с адаптивными параметрами. Проведены эксперименты по поиску глобального оптимума многомерной функции на основе предложенного метода.Досліджено мультиагентний підхід до оптимізації багатовимірних нелінійних функцій. Розроблено мультиагентний метод оптимізації з адаптивними параметрами. Проведено експерименти по пошуку глобального оптимуму багатовимірної функції на основі запропонованого методу.The approach to optimization of multidimensional nonlinear functions is investigated. The multiagent optimization method with adaptive parameters is developed. Experiments on search of global optimum of multidimensional function based on the offered method are made

Редукция баз нечётких правил на основе мультиагентного подхода

В статье рассмотрена актуальная задача отбора и преобразования баз нечётких правил, которые используются в экспертных системах. Для решения данной задачи предложен мультиагентный метод с непрямой связью между агентами, учитывающий взаимовлияние правил при прогнозировании. Проведены эксперименты по решению тестовых задач. Полученные результаты показали эффективность разработанного метода

Organisation of foraging in ants

In social insects, foraging is often cooperative, and so requires considerable organisation. In most ants, organisation is a bottom-up process where decisions taken by individuals result in emergent colony level patterns. Individuals base their decisions on their internal state, their past experience, and their environment. By depositing trail pheromones, for example, ants can alter the environment, and thus affect the behaviour of their nestmates. The development of emergent patterns depends on both how individuals affect the environment, and how they react to changes in the environment. Chapters 4 – 9 investigate the role of trail pheromones and route memory in the ant Lasius niger. Route memories can form rapidly and be followed accurately, and when route memories and trail pheromones contradict each other, ants overwhelmingly follow route memories (chapter 4). Route memories and trail pheromones can also interact synergistically, allowing ants to forage faster without sacrificing accuracy (chapter 5). Home range markings also interact with other information sources to affect ant behaviour (chapter 6). Trail pheromones assist experienced ants when facing complex, difficult-to-learn routes (chapter 7). When facing complicated routes, ants deposit more pheromone to assist in navigation and learning (chapter 7). Deposition of trail pheromones is suppressed by ants leaving a marked path (chapter 5), strong pheromone trails (chapter 7) and trail crowding (chapter 8). Colony level ‘decisions’ can be driven by factors other than trail pheromones, such as overcrowding at a food source (chapter 9). Chapter 10 reviews the many roles of trail pheromones in ants. Chapters 11 – 14 focus on the organisation of cooperative food retrieval. Pheidole oxyops workers arrange themselves non-randomly around items to increase transport speeds (chapter 11). Groups of ants will rotate food items to reduce drag (chapter 12). Chapters 13 and 14 encompass the ecology of cooperative transport, and how it has shaped trail pheromone recruitment in P. oxyops and Paratrechina longicornis. Lastly, chapter 15 provide a comprehensive review of cooperative transport in ants and elsewhere

Group selection

Postprin

Communication and cooperation in evolutionary biology

How can the concepts and results of communication theory aid evolutionary biology? This thesis argues for an explanatory framework, evolutionary communication theory, that interprets and illuminates scientific research into the phenomenon of biological signalling. By expanding the theory beyond the models and goals familiar to Claude Shannon and other engineers, real insight is gained into how strategic interplay between senders and receivers shapes signal form. Furthermore, interpreting artificial and natural signals in terms of sender-receiver teleosemantics demonstrates the explanatory role of relations borne between signals and world affairs. One of the major results of the thesis is a rejection of the orthodox distinction between Shannon and semantic information. While there are at least two useful distinctions to be drawn -- between cues and signals, and between statistical and functional content -- the terminological confusion that gave rise to the phrase `Shannon information' should be put aside for good. Chapter 1 outlines a way to capture the relationships between signals and other signal-like interactions using a multi-dimensional conceptual space called a hypercube. I argue that sender-receiver teleosemantics is uniquely well suited to capturing those aspects of communication theory that render it a viable mathematical framework for evolutionary biology. Chapter 2 discusses an early attempt to apply communication theory in evolutionary biology. Haldane & Spurway's informational interpretation of the honeybee waggle dance has recently been criticised on mathematical grounds. These criticisms lend support to scepticism about the relevance of information for evolutionary biology. I argue that the criticisms are themselves mathematically erroneous, so one route to scepticism about information is undercut. Chapter 3 explores a related line of scepticism. It is common in the philosophy of biology to treat the concepts and tools of communication theory as insufficient or irrelevant for analysing semantic content. I argue that the grounds of this supposition are based on misinterpretations of some features of communication theory. In chapter 4 I reconstruct Millikan's teleosemantics in a causal-modelling setting, highlighting the explanatory role of semantic content. In chapter 5 I respond to objections to the teleosemantic account, including the claim that the theory renders explanations of success that appeal to semantic content circular. I also argue for an interpretation of important features of communication-theoretic models in terms of teleosemantics. Chapter 6 explores another challenge to applying teleosemantics to biological signals. The theory places emphasis on cooperation between senders and receivers, but biological signals are often fraught with evolutionary conflict. I discuss recent formal work, and argue that prospects for teleosemantics are good. Finally, in chapter 7 I argue that an explanatory framework that draws on communication-theoretic concepts would be beneficial to evolutionary biology. I present case studies of communicative behaviour for which biologists offer explanations that are well interpreted through the principles of communications engineering

Vampiric enterprise : metaphors of economic exploitation in the literature and culture of the fin de siecle

This thesis is about the complex network of metaphors that emerged around late nineteenth-century conceptions of economic self-interest — metaphors that dramatised the predatory, conflictual and exploitative basis of relations between nations, institutions, sexes and people in an outwardly belligerent fin-de-siècle economy. More specifically, this thesis is about the vampire, cannibal and related genera of economic metaphor which I argue penetrate many of the major discourses of the period in ways that have yet to be understood. In chapters that examine socialist fiction and newspapers; the imperial quest romance; inter-personal intimacies in the writing of Henry James and Vernon Lee; and the Catholic novels of Lucas Malet, I assess the breadth and variety of these metaphors, and consider how they filter the concept of the conflictual ‘economic man’ inspired by Hobbes and formalised in nineteenth-century economic discourses. The thesis builds on Maggie Kilgour’s From communion to cannibalism: an anatomy of metaphors of incorporation (1990), which traces the genealogy – in literature from Homer to Melville – of what she terms ‘metaphors of incorporation’. In basic terms, these are metaphors that originate from a foundational inside-outside binary and involve the assimilation or incorporation of an external reality. Kilgour attempts to demonstrate that with the increasing isolation of the modern individual (signalled by the acts of enclosure and the formalisation of property rights, for instance) acts of ‘incorporation’ previously imagined as symbiotic (early communion), were later conceived as cannibalistic (oedipal rivalry). Representing an appetitive antagonism between aggressor and victim, the figures at the centre of this study – the economic vampire and its cognates – have integrity as metaphors of incorporation. However, deploying a combination of historicist and, at times, Post-Structuralist approaches, this thesis demonstrates that these metaphors refuse to accommodate themselves to a simple unified vision of the kind advanced by Kilgour. Therefore, in this thesis, I map the complexities of these metaphors, explaining how they originate from divergent teleological impulses and how they articulate both simple ideological operations, and more complex feelings of ambivalence about economic realities in the cultural moment of the Victorian fin-de-siècle.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Vampiric enterprise : metaphors of economic exploitation in the literature and culture of the fin de siecle

This thesis is about the complex network of metaphors that emerged around late nineteenth-century conceptions of economic self-interest — metaphors that dramatised the predatory, conflictual and exploitative basis of relations between nations, institutions, sexes and people in an outwardly belligerent fin-de-siècle economy. More specifically, this thesis is about the vampire, cannibal and related genera of economic metaphor which I argue penetrate many of the major discourses of the period in ways that have yet to be understood. In chapters that examine socialist fiction and newspapers; the imperial quest romance; inter-personal intimacies in the writing of Henry James and Vernon Lee; and the Catholic novels of Lucas Malet, I assess the breadth and variety of these metaphors, and consider how they filter the concept of the conflictual ‘economic man’ inspired by Hobbes and formalised in nineteenth-century economic discourses. The thesis builds on Maggie Kilgour’s From communion to cannibalism: an anatomy of metaphors of incorporation (1990), which traces the genealogy – in literature from Homer to Melville – of what she terms ‘metaphors of incorporation’. In basic terms, these are metaphors that originate from a foundational inside-outside binary and involve the assimilation or incorporation of an external reality. Kilgour attempts to demonstrate that with the increasing isolation of the modern individual (signalled by the acts of enclosure and the formalisation of property rights, for instance) acts of ‘incorporation’ previously imagined as symbiotic (early communion), were later conceived as cannibalistic (oedipal rivalry). Representing an appetitive antagonism between aggressor and victim, the figures at the centre of this study – the economic vampire and its cognates – have integrity as metaphors of incorporation. However, deploying a combination of historicist and, at times, Post-Structuralist approaches, this thesis demonstrates that these metaphors refuse to accommodate themselves to a simple unified vision of the kind advanced by Kilgour. Therefore, in this thesis, I map the complexities of these metaphors, explaining how they originate from divergent teleological impulses and how they articulate both simple ideological operations, and more complex feelings of ambivalence about economic realities in the cultural moment of the Victorian fin-de-siècle.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

The twilight of customary land systems? : effects of the new wave land formalisation programmes on rural livelihoods in Tanzania

viii, 220 leaves : illustrations (chiefly colour) , maps (chiefly colour) ; 29 cmIncludes abstract and appendices.Includes bibliographical references (leaves 192-213).Forms of customary land ownership in sub-Saharan Africa are a key element of African social organisation and have sustained and continue to sustain millions of subsistence and smallholder farmers by maintaining livelihoods in spite of significant economic and political change. More recently, attempts to increase productivity in rural areas, thereby enhancing development efforts, have taken the form of land formalisation programmes aimed at the privatisation of customary lands and the adoption of agricultural policies that emphasize growth rather than development. Yet these have often resulted in the failure to protect the livelihoods of rural populations and facilitating land grabbing. In light of these failures, they have since been reformulated into a ‘new wave’ of land formalisation whose objective is to incorporate elements of customary systems. The thesis asks therefore whether the new wave programmes have been successful in improving the quality of life and economic well-being of rural populations? We argue that even these new wave programmes will not protect rural livelihoods in the communal areas because they emphasise instead market fundamentalism which sees rural organisation and agricultural policy as driven by competition, profit motive, privatisation, and commodification of land. We undertook a qualitative case study of the implementation of ‘new wave’ land formalisation programme in three villages in Tanzania, which are Mbagwi, Mzeri, and Sindeni, all located in Handeni district, Tanga region. The study sought to find out how rural social organisation has been altered since the implementation of the formalisation programmes, and also information on agricultural production in order to demonstrate how smallholder farmers’ tenure security, sources of income and food security are being affected. The study found that the implementation of the new wave formalisation programmes is eroding key elements of customary ownership systems. Custom and norms of cooperation and reciprocity are dwindling, as evidenced by participants reporting the disappearance of such things as labour and food sharing practices, as well as norms that exhort eschewing selfishness in favour of actions that benefit all the members of the village. Further, strict land use plans eliminate flexibility in the use of land, and enhanced functioning of land markets undermines the permanency of land availability to poorer members of the society. Furthermore, the thesis concludes that agricultural models associated with the formalisation programmes have resulted in policies and economic strategies that are focused primarily on how to increase production, disregarding the implications on environment and on the livelihoods of rural dwellers