15,716 research outputs found
Embodying entrepreneurship: everyday practices, processes and routines in a technology incubator
The growing interest in the processes and practices of entrepreneurship has
been dominated by a consideration of temporality. Through a thirty-six-month
ethnography of a technology incubator, this thesis contributes to extant
understanding by exploring the effect of space. The first paper explores how
class structures from the surrounding city have appropriated entrepreneurship
within the incubator. The second paper adopts a more explicitly spatial analysis
to reveal how the use of space influences a common understanding of
entrepreneurship. The final paper looks more closely at the entrepreneurs within
the incubator and how they use visual symbols to develop their identity. Taken
together, the three papers reject the notion of entrepreneurship as a primarily
economic endeavour as articulated through commonly understood language and
propose entrepreneuring as an enigmatic attractor that is accessed through the
ambiguity of the non-verbal to develop the ‘new’. The thesis therefore contributes
to the understanding of entrepreneurship and proposes a distinct role for the non-verbal in that understanding
How to Be a God
When it comes to questions concerning the nature of Reality, Philosophers and Theologians have the answers.
Philosophers have the answers that can’t be proven right. Theologians have the answers that can’t be proven wrong.
Today’s designers of Massively-Multiplayer Online Role-Playing Games create realities for a living. They can’t spend centuries mulling over the issues: they have to face them head-on. Their practical experiences can indicate which theoretical proposals actually work in practice.
That’s today’s designers. Tomorrow’s will have a whole new set of questions to answer.
The designers of virtual worlds are the literal gods of those realities. Suppose Artificial Intelligence comes through and allows us to create non-player characters as smart as us. What are our responsibilities as gods? How should we, as gods, conduct ourselves?
How should we be gods
Response of saline reservoir to different phaseCOâ‚‚-brine: experimental tests and image-based modelling
Geological CO₂ storage in saline rocks is a promising method for meeting the target of net zero emission and minimizing the anthropogenic CO₂ emitted into the earth’s atmosphere. Storage of CO₂ in saline rocks triggers CO₂-brine-rock interaction that alters the properties of the rock. Properties of rocks are very crucial for the integrity and efficiency of the storage process. Changes in properties of the reservoir rocks due to CO₂-brine-rock interaction must be well predicted, as some changes can reduce the storage integrity of the reservoir. Considering the thermodynamics, phase behavior, solubility of CO₂ in brine, and the variable pressure-temperature conditions of the reservoir, there will be undissolved CO₂ in a CO₂ storage reservoir alongside the brine for a long time, and there is a potential for phase evolution of the undissolved CO₂. The phase of CO₂ influence the CO₂-brine-rock interaction, different phaseCO₂-brine have a unique effect on the properties of the reservoir rocks, Therefore, this study evaluates the effect of four different phaseCO₂-brine reservoir states on the properties of reservoir rocks using experimental and image-based approach.
Samples were saturated with the different phaseCOâ‚‚-brine, then subjected to reservoir conditions in a triaxial compression test. The representative element volume (REV)/representative element area (REA) for the rock samples was determined from processed digital images, and rock properties were evaluated using digital rock physics and rock image analysis techniques. This research has evaluated the effect of different phaseCOâ‚‚-brine on deformation rate and deformation behavior, bulk modulus, compressibility, strength, and stiffness as well as porosity and permeability of sample reservoir rocks. Changes in pore geometry properties, porosity, and permeability of the rocks in COâ‚‚ storage conditions with different phaseCOâ‚‚-brine have been evaluated using digital rock physics techniques. Microscopic rock image analysis has been applied to provide evidence of changes in micro-fabric, the topology of minerals, and elemental composition of minerals in saline rocks resulting from different phaseCOâ‚‚-br that can exist in a saline COâ‚‚ storage reservoir. It was seen that the properties of the reservoir that are most affected by the scCOâ‚‚-br state of the reservoir include secondary fatigue rate, bulk modulus, shear strength, change in the topology of minerals after saturation as well as change in shape and flatness of pore surfaces. The properties of the reservoir that is most affected by the gCOâ‚‚-br state of the reservoir include primary fatigue rate, change in permeability due to stress, change in porosity due to stress, and change topology of minerals due to stress. For all samples, the roundness and smoothness of grains as well as smoothness of pores increased after compression while the roundness of pores decreased. Change in elemental composition in rock minerals in COâ‚‚-brine-rock interaction was seen to depend on the reactivity of the mineral with COâ‚‚ and/or brine and the presence of brine accelerates such change. Carbon, oxygen, and silicon can be used as index minerals for elemental changes in a COâ‚‚-brine-rock system. The result of this work can be applied to predicting the effect the different possible phases of COâ‚‚ will have on the deformation, geomechanics indices, and storage integrity of giant COâ‚‚ storage fields such as Sleipner, In Salah, etc
Interactive Sonic Environments: Sonic artwork via gameplay experience
The purpose of this study is to investigate the use of video-game technology in the design and implementation of interactive sonic centric artworks, the purpose of which is to create and contribute to the discourse and understanding of its effectiveness in electro-acoustic composition highlighting the creative process. Key research questions include: How can the language of electro-acoustic music be placed in a new framework derived from videogame aesthetics and technology? What new creative processes need to be considered when using this medium? Moreover, what aspects of 'play' should be considered when designing the systems? The findings of this study assert that composers and sonic art practitioners need little or no coding knowledge to create exciting applications and the myriad of options available to the composer when using video-game technology is limited only by imagination. Through a cyclic process of planning, building, testing and playing these applications the project revealed advantages and unique sonic opportunities in comparison to other sonic art installations. A portfolio of selected original compositions, both fixed and open are presented by the author to complement this study. The commentary serves to place the work in context with other practitioners in the field and to provide compositional approaches that have been taken
Studies of strategic performance management for classical organizations theory & practice
Nowadays, the activities of "Performance Management" have spread very broadly in actually every part of business and management. There are numerous practitioners and researchers from very different disciplines, who are involved in exploring the different contents of performance management. In this thesis, some relevant historic developments in performance management are first reviewed. This includes various theories and frameworks of performance management. Then several management science techniques are developed for assessing performance management, including new methods in Data Envelopment Analysis (DEA) and Soft System Methodology (SSM). A theoretical framework for performance management and its practical procedures (five phases) are developed for "classic" organizations using soft system thinking, and the relationship with the existing theories are explored. Eventually these results are applied in three case studies to verify our theoretical development. One of the main contributions of this work is to point out, and to systematically explore the basic idea that the effective forms and structures of performance management for an organization are likely to depend greatly on the organizational configuration, in order to coordinate well with other management activities in the organization, which has seemingly been neglected in the existing literature of performance management research in the sense that there exists little known research that associated particular forms of performance management with the explicit assumptions of organizational configuration. By applying SSM, this thesis logically derives some main functional blocks of performance management in 'classic' organizations and clarifies the relationships between performance management and other management activities. Furthermore, it develops some new tools and procedures, which can hierarchically decompose organizational strategies and produce a practical model of specific implementation steps for "classic" organizations. Our approach integrates popular types of performance management models. Last but not least, this thesis presents findings from three major cases, which are quite different organizations in terms of management styles, ownership, and operating environment, to illustrate the fliexbility of the developed theoretical framework
Anytime algorithms for ROBDD symmetry detection and approximation
Reduced Ordered Binary Decision Diagrams (ROBDDs) provide a dense and memory efficient representation of Boolean functions. When ROBDDs are applied in logic synthesis, the problem arises of detecting both classical and generalised symmetries. State-of-the-art in symmetry detection is represented by Mishchenko's algorithm. Mishchenko showed how to detect symmetries in ROBDDs without the need for checking equivalence of all co-factor pairs. This work resulted in a practical algorithm for detecting all classical symmetries in an ROBDD in O(|G|³) set operations where |G| is the number of nodes in the ROBDD. Mishchenko and his colleagues subsequently extended the algorithm to find generalised symmetries. The extended algorithm retains the same asymptotic complexity for each type of generalised symmetry. Both the classical and generalised symmetry detection algorithms are monolithic in the sense that they only return a meaningful answer when they are left to run to completion. In this thesis we present efficient anytime algorithms for detecting both classical and generalised symmetries, that output pairs of symmetric variables until a prescribed time bound is exceeded. These anytime algorithms are complete in that given sufficient time they are guaranteed to find all symmetric pairs. Theoretically these algorithms reside in O(n³+n|G|+|G|³) and O(n³+n²|G|+|G|³) respectively, where n is the number of variables, so that in practice the advantage of anytime generality is not gained at the expense of efficiency. In fact, the anytime approach requires only very modest data structure support and offers unique opportunities for optimisation so the resulting algorithms are very efficient. The thesis continues by considering another class of anytime algorithms for ROBDDs that is motivated by the dearth of work on approximating ROBDDs. The need for approximation arises because many ROBDD operations result in an ROBDD whose size is quadratic in the size of the inputs. Furthermore, if ROBDDs are used in abstract interpretation, the running time of the analysis is related not only to the complexity of the individual ROBDD operations but also the number of operations applied. The number of operations is, in turn, constrained by the number of times a Boolean function can be weakened before stability is achieved. This thesis proposes a widening that can be used to both constrain the size of an ROBDD and also ensure that the number of times that it is weakened is bounded by some given constant. The widening can be used to either systematically approximate an ROBDD from above (i.e. derive a weaker function) or below (i.e. infer a stronger function). The thesis also considers how randomised techniques may be deployed to improve the speed of computing an approximation by avoiding potentially expensive ROBDD manipulation
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Effect of Prior Plastic Strain on the High Temperature Creep Deformation and Damage Response of Type 316H Stainless Steel
Creep damage in ductile alloys is associated with creep deformation, crack growth and starts with the nucleation and growth of cavities. Under sustained high temperature and stress conditions, growing cavities can start to coalesce leading to microcracking and ultimate failure of a component. This mechanism can limit the lifetime of power plant components operating at high temperature. Many engineering components enter service in a cold-worked or prestrained condition as a result of manufacturing processes such as bending, forging, welding etc. Such pre-conditioning alters the creep resistance of the material significantly. Its effect on the creep deformation properties of a structure during service, and creep damage response can be advantageous for some materials but disadvantageous for others. Hence it is crucial to understand the effects of prior plastic strain when assessing the lifetime and safety of power plant components, for example in the context of nuclear power generation. The research set out in this thesis aims to examine the effect of prior plastic strain on subsequent creep deformation behaviour and development of damage in AISI Type 316H austenitic stainless steel, a material widely used in the fleet of Advanced Gas Cooled reactors operated by EDF Energy in the UK.
A novel cylindrical hourglass-shaped test specimen was designed for the research where a constant applied load provided a variation in uniaxial stress and associated creep strain rate along the hourglass gauge length. A further innovation in this PhD work involved exploiting the potential of 3D digital image correlation (3D-DIC) for measuring spatially resolved creep deformation along the hourglass gauge section over long duration creep tests at a high temperature of 550â—¦C. The scope of testing included load-controlled creep tests carried out on 5 samples where 0, 4, 8, 12 and 16% of prior tensile plastic strain was introduced at room temperature. The prestraining was carried out on cylindrical samples before the hourglass shape was machined, ensuring a uniform level of prior plastic strain was present along the gauge section prior to creep experiments. It was found that prior plastic strain increased the creep resistance of the as-received material. Increasing plastic strain decreased the creep strain rate and creep ductility. On the other hand, it resulted in an increase in time to failure.
After creep failure at the maximum stress location, small-angle neutron scattering (SANS) was utilised to investigate changes in creep cavitational damage as a function of applied stress, level of creep strain and prior plastic strain at room temperature. Two sets of experiments were performed using the D11 instrument at the ILL reactor source (France) and the SANS2D instrument at the ISIS spallation source (UK). Very similar scattering results were obtained from the two instruments. Furthermore, SANS data from the instruments were analysed using two independent analysis routes; a maximum entropy method (MAXE) and a Monte Carlo algorithm (McSAS). Since SANS is an indirect method for measuring creep cavitation, the microstructure of the specimens was also investigated using qualitative scanning electron microscopy (SEM) in order to interpret and verify the SANS cavitation observations. The SANS investigations revealed a strong correlation between the volume fraction and number density of creep cavities with applied stress and creep strain. Furthermore, an increasing number density of small creep cavities as a function of prior plastic strain was observed and verified by qualitative SEM studies. This is new evidence that prior plastic strain, induced at room temperature, introduces specific cavitational damage in Type 316H stainless steel. The macroscopic damage calculation based on the stress modified ductility exhaustion model revealed that the majority of damage for the series of prestrained specimens is caused by plastic hole growth as a consequence of inducing prior plastic strain rather than due to creep related diffusion processes
On the Hasse Principle for Systems of Forms
We prove the Hasse principle for a smooth projective variety defined by a smooth system of two cubic polynomials in variables. The main tool here is the development of a version of Kloosterman refinement for a smooth system of equations defined over
Patterns of subspecies diversity in the giraffe, Giraffa camelopardalis (L. 1758): comparison of systematic methods and their implications for conservation policy
This thesis examines the subspecific taxonomic status of the giraffe and considers the role of formal taxonomy in the formulation of conservation policy. Where species show consistent. geographically structured phenotypic variation such geographic patterns may indicate selective forces (or other population-level effects) acting. upon local populations. These consistent geographic patterns may be recognised formally as subspecies and may be of interest in single or multi-species biodiversity or biogeography studies for delimiting areas of conservation priority. Subspecies may also be used in the formulation of management policies and legislation. Subspecies are, by definition, allopatric. This thesis explicitly uses methodology of systematic biology and phylogenetic reconstruction to investigate patterns of variation between geographic groups. The taxonomic status of the giraffe is apposite for review. The species provides three independent data sets that may be analysed quantitatively for geographic structure; pelage patterns, morphology and genetics. Museum specimens. grouped according to geographic origin, were favoured for study as more than one type of data was often available for an individual. Population aggregation analysis of forty pelage pattern characters maintained six separate subspecies, while agglomerating some neighbouring populations into a subspecies. A 'traditional' morphometric approach, using multivariate statistical analysis of adult skull measurements, was complemented by a geometric morphometric approach; landmarkrestricted eigenshape analysis. Four morphologically distinct groups were recognised by both morphological analyses. Phylogenetic analysis of mitochondrial DNA control region sequences indicates five major cIades. Nested cIade analysis identifies population fragmentation, range expansion and genetic isolation by distance as contributing to the genetic structure of the giraffe. The results of the analyses show remarkable congruence. These results are discussed in terms of the formulation of conservation policy and the differing requirements of'blological and legal classification systems. The value of a formal taxonomic framework to the recognition, and subsequent conservation, of biodiversity is emphasised
The social and psychological work of metaphor: a corpus linguistic investigation
This thesis investigates the triangular relationship between metaphor use, community, and state of mind, to ask the question: what social and psychological work does metaphor do, in the computer-mediated discourse setting of an online forum. The thesis goes beyond the finding and grouping of metaphors for analysis to consider the pattern of metaphor use over time in terms of (i) surrounding language style; (ii) density of use; and (iii) use by different participant groups. In achieving its aim the thesis provides insights into (i) the effect of metaphor use in terms of state of mind; (ii) the role of metaphor in the characterisation of a community; and (iii) methods for considering linguistic metaphor in naturally occurring discourse in terms of its psychological effect, which also creates insights into metaphor theory.
The primary novel contribution of the thesis is to combine an analysis of metaphor use with an analysis of the language style that surrounds it, using established research relating language style to state of mind to consider the social and psychological work that metaphor does. The primary prediction of the investigation is that where metaphor is used to characterise a concept, the surrounding language will be of a style that has been found to be associated with better mental health. This is related to and supported by the second novel contribution of the thesis, which is to consider the role of metaphor in the formation and evolution of a community over time, by considering change in density of metaphor and other key variables in the data as a whole, and for comparative participant groups. The third novel contribution of the thesis is that, alongside more established corpus linguistic techniques, new techniques from the fast-evolving areas of data science and natural language processing are explored and evaluated in terms of (i) finding metaphors in the corpora; (ii) analysing language style; and (iii) diachronic analysis.
It is shown that use of the identified dominant metaphor themes in each community co-occurs with specific language styles associated with mental health, and that this work of metaphor evolves over time as a consensus which becomes normative within the group for a period, such that it shapes community members as well as being shaped by them, while the flexibility of metaphor still leaves that work open to further evolution. The adaptation and prominence of particular metaphor themes over time to do particular work in each forum also underpins the characterisation of it as a particular community
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