Convex hulls in concept induction

Classification learning is dominated by systems which induce large numbers of small axis-orthogonal decision surfaces. This strongly biases such systems towards particular hypothesis types but there is reason believe that many domains have underlying concepts which do not involve axis orthogonal surfaces. Further, the multiplicity of small decision regions mitigates against any holistic appreciation of the theories produced by these systems, notwithstanding the fact that many of the small regions are individually comprehensible. This thesis investigates modeling concepts as large geometric structures in n-dimensional space. Convex hulls are a superset of the set of axis orthogonal hyperrectangles into which axis orthogonal systems partition the instance space. In consequence, there is reason to believe that convex hulls might provide a more flexible and general learning bias than axis orthogonal regions. The formation of convex hulls around a group of points of the same class is shown to be a usable generalisation and is more general than generalisations produced by axis-orthogonal based classifiers, without constructive induction, like decision trees, decision lists and rules. The use of a small number of large hulls as a concept representation is shown to provide classification performance which can be better than that of classifiers which use a large number of small fragmentary regions for each concept. A convex hull based classifier, CH1, has been implemented and tested. CH1 can handle categorical and continuous data. Algorithms for two basic generalisation operations on hulls, inflation and facet deletion, are presented. The two operations are shown to improve the accuracy of the classifier and provide moderate classification accuracy over a representative selection of typical, largely or wholly continuous valued machine learning tasks. The classifier exhibits superior performance to well-known axis-orthogonal-based classifiers when presented with domains where the underlying decision surfaces are not axis parallel. The strengths and weaknesses of the system are identified. One particular advantage is the ability of the system to model domains with approximately the same number of structures as there are underlying concepts. This leads to the possibility of extraction of higher level mathematical descriptions of the induced concepts, using the techniques of computational geometry, which is not possible from a multiplicity of small regions.

Concept design of a novel tactile probe tip for down scaled 3D CMMs

Although coordinate metrology has reached a very high state of development concerning versatility and accuracy for common engineering parts, a high precision capability with nano scale resolution and accuracy is often hard to achieve when it is required to measure very small parts and features. The limiting component is the bulky probing system of traditional CMMs (coordinate measuring machines). In order to satisfy increasing demand for highly accurate geometrical measurements on small parts and small structures, a new measuring probe of high sensitivity and small geometrical dimension with low contact forces needs to be developed. In this paper, a novel probing system, which combines a FBG (Fibre Bragg Grating) embedded optical fibre tactile probe with an optical sensing technique, has been proposed. With the sensor elements integrated into the probe tip directly, the system sensitivity can be increased significantly. A preliminary theoretical analysis of the sensitivity of the FBG fibre sensor under axial and lateral end point loading has been presented and the results show that this micro scale probe has great potential to realize a resolution of 1nanometer on geometrical measurement of small parts.

Family breakdown, the best interests of the child concept, and the legal system

It appears that the legal system's response to the issues relating to family breakdown and "the best interests of the child" concept can sometimes be inadequate. There also appears to a lack of consistency with regards to enforcing the best interests of the child concept in legal proceedings concerning children.

The decline of the notion of soul and the rise of the concept of self

This thesis examines the ethics of genetic engineering from the frame of reference of the human individual.

Concept of innocence in the thought of Simone Weil

Addresses common criticisms of Simone Weil's thought as both world-denying and as utopian or escapist. Considers Weil's life and examines her cosmology. Concludes that Weil's thought is in fact world and life affirming, and oriented towards living in the world.

Exploration of nurses' lived-experiences and understandings of the concept of healing

Explores nurses' understandings of the concept of healing, within the context of a nurse/patient relationship. Hermeneutic phenomenology is the research methodology and story-telling the means of data collection. From these descriptions, new understandings have been sought and therapeutic possibilities actively explored.

Potential of technology and a familiar context to enhance students' concept of rate of change

Students' concept image of rate of change may be incomplete or erroneous. This paper reports a pilot study, with secondary school students, which explores the potential of technology (JavaMathWorlds), depicting a familiar context of motion, to develop students' existing schema of informal understandings of rate of change to more formal mathematical representations. Students developed numerous 'models of' rate of change in a motion context which then transferred to serve as a 'model for' rate of change in other contexts.

Efficacité de l'aide et sélectivité : vers un concept élargi

This paper surveys recent research on aid and growth. It also provides an overview of research on inter-recipient aid allocation.

Formalizing the concept of entrepreneurial capacity

This study develops a definition of the concept of entrepreneurial capacity and formalizes it in two models explaining how value is created in the innovation process. The formalization integrates the influential opportunity-based definition of entrepreneurship research offered by Shane and Venkataraman (2000) with the consensus prevailing in the management, strategy, economics and entrepreneurship literatures that innovation is a process for transforming the inherent economic value of new knowledge into realized economic value for identified stakeholders. The linear flow and mathematical models presented in the study possess the clarity and richness required of a theoretical framework for generating and testing insightful hypotheses. This study, regarding Penrose (1959) more as theorist of entrepreneurship than of resources, deepens scepticism about the relevance to entrepreneurship of the literatures on the resource-based view of the firm (RBV) and dynamic capabilities (DC). Finally, the arguments and perspectives of the study imply several pedagogic possibilities and challenges for entrepreneurship educators.

On the concept of ionicity in ionic liquids

Ionic liquids are liquids comprised totally of ions. However, not all of the ions present appear to be available to participate in conduction processes, to a degree that is dependent on the nature of the ionic liquid and its structure. There is much interest in quantifying and understanding this ‘degree of ionicity’ phenomenon. In this paper we present transport data for a range of ionic liquids and evaluate the data firstly in terms of the Walden plot as an approximate and readily accessible approach to estimating ionicity. An adjusted Walden plot that makes explicit allowance for differences in ion sizes is shown to be an improvement to this approach for the series of ionic liquids described. In some cases, where diffusion measurements are possible, it is feasible to directly quantify ionicity via the Nernst–Einstein equation, confirming the validity of the adjusted Walden plot approach. Some of the ionic liquids studied exhibit ionicity values very close to ideal; this is discussed in terms of a model of a highly associated liquid in which the ion correlations have similar impact on both the diffusive and conductive motions. Ionicity, as defined, is thus a useful measure of adherence to the Nernst–Einstein equation, but is not necessarily a measure of ion availability in the chemical sense.

Self-concept clarity and women's sexual well-being

The purpose of this study was to examine the role of self-concept clarity, a core structural aspect of self-concept, in women's sexual well-being. A convenience sample of 261 women aged 18 years and over {M=25.8, £D=7.9) completed an online survey that measured self-concept clarity, three aspects of sexual well-being (sexual self-efñcacy, sexual self-esteem and sexual satisfaction), and four structural dimensions of sexual identity (commitment, synthesis/integration, exploration, and orientation identity uncertainty). A series of multiple mediation analyses, followed by post-hoc bootstrap tests of the difference between mediation effects, revealed that self-concept clarity is indirectly related to the measures of sexual well-being, and that these relationships are mediated by the two "investment-related" dimensions of sexual identity: commitment and synthesis/integration. These results suggest that women with a more broadly and coherently integrated sexual identity are also better able to make healthy and positive choices in the sexual domain and experience more satisfaction with their sex lives, i^ore generally, the results highlight the potential importance of including structural aspects of self-concept in explanations of women's sexual well-being.