14 resultados para Iran--Description and travel
em Aston University Research Archive
Resumo:
Attractor properties of a popular discrete-time neural network model are illustrated through numerical simulations. The most complex dynamics is found to occur within particular ranges of parameters controlling the symmetry and magnitude of the weight matrix. A small network model is observed to produce fixed points, limit cycles, mode-locking, the Ruelle-Takens route to chaos, and the period-doubling route to chaos. Training algorithms for tuning this dynamical behaviour are discussed. Training can be an easy or difficult task, depending whether the problem requires the use of temporal information distributed over long time intervals. Such problems require training algorithms which can handle hidden nodes. The most prominent of these algorithms, back propagation through time, solves the temporal credit assignment problem in a way which can work only if the relevant information is distributed locally in time. The Moving Targets algorithm works for the more general case, but is computationally intensive, and prone to local minima.
Resumo:
Principal components analysis (PCA) has been described for over 50 years; however, it is rarely applied to the analysis of epidemiological data. In this study PCA was critically appraised in its ability to reveal relationships between pulsed-field gel electrophoresis (PFGE) profiles of methicillin- resistant Staphylococcus aureus (MRSA) in comparison to the more commonly employed cluster analysis and representation by dendrograms. The PFGE type following SmaI chromosomal digest was determined for 44 multidrug-resistant hospital-acquired methicillin-resistant S. aureus (MR-HA-MRSA) isolates, two multidrug-resistant community-acquired MRSA (MR-CA-MRSA), 50 hospital-acquired MRSA (HA-MRSA) isolates (from the University Hospital Birmingham, NHS Trust, UK) and 34 community-acquired MRSA (CA-MRSA) isolates (from general practitioners in Birmingham, UK). Strain relatedness was determined using Dice band-matching with UPGMA clustering and PCA. The results indicated that PCA revealed relationships between MRSA strains, which were more strongly correlated with known epidemiology, most likely because, unlike cluster analysis, PCA does not have the constraint of generating a hierarchic classification. In addition, PCA provides the opportunity for further analysis to identify key polymorphic bands within complex genotypic profiles, which is not always possible with dendrograms. Here we provide a detailed description of a PCA method for the analysis of PFGE profiles to complement further the epidemiological study of infectious disease. © 2005 Elsevier B.V. All rights reserved.
Resumo:
Textured regions in images can be defined as those regions containing a signal which has some measure of randomness. This thesis is concerned with the description of homogeneous texture in terms of a signal model and to develop a means of spatially separating regions of differing texture. A signal model is presented which is based on the assumption that a large class of textures can adequately be represented by their Fourier amplitude spectra only, with the phase spectra modelled by a random process. It is shown that, under mild restrictions, the above model leads to a stationary random process. Results indicate that this assumption is valid for those textures lacking significant local structure. A texture segmentation scheme is described which separates textured regions based on the assumption that each texture has a different distribution of signal energy within its amplitude spectrum. A set of bandpass quadrature filters are applied to the original signal and the envelope of the output of each filter taken. The filters are designed to have maximum mutual energy concentration in both the spatial and spatial frequency domains thus providing high spatial and class resolutions. The outputs of these filters are processed using a multi-resolution classifier which applies a clustering algorithm on the data at a low spatial resolution and then performs a boundary estimation operation in which processing is carried out over a range of spatial resolutions. Results demonstrate a high performance, in terms of the classification error, for a range of synthetic and natural textures
Resumo:
China is unique both politically and economically. How this uniqueness impacts on firms'' adoption of market orientation and the impact of market orientation on business performance, however, remain unclear. This book reports a study by Dr Riliang Qu who aims to address the above knowledge void. The study employs a two-stage research strategy including interviews and a survey of 1000 hotels and travel services. The study found that government regulations restricting the firm rivalry and the shortage of competent managerial talents are among the most serious constraints to the firms'' development of market orientation along with such factors as inadequacy of government regulation on product quality and consumer protection. The findings suggest that in transitional like China, government actions could be a major force behind firms'' aspiration of being market-oriented. The study also found that the benefits of market orientation are multi-fold in that it not only improves company''s business performance but also has positive effects on customer satisfaction/retention, power in distribution channel, and corporate social responsibility.
Resumo:
Background - Specialist Lifestyle Management (SLiM) is a structured patient education and self-management group weight management programme. Each session is run monthly over a 6-month period providing a less intensive long-term approach. The groups are patient-centred incorporating educational, motivational, behavioural and cognitive elements. The theoretical background, programme structure and preliminary results of SLiM are presented. Subjects/methods - The study was a pragmatic service evaluation of obese patients with a body mass index (BMI) ≥35 kg/m2 with comorbidity or ≥40 kg/m2 without comorbidity referred to a specialist weight management service in the West Midlands, UK. 828 patients were enrolled within SLiM over a 48-month period. Trained facilitators delivered the programme. Preliminary anonymised data were analysed using the intention-to-treat principle. The primary outcome measure was weight loss at 3 and 6 months with comparisons between completers and non-completers performed. The last observation carried forward was used for missing data. Results - Of the 828 enrolled within SLiM, 464 completed the programme (56%). The mean baseline weight was 135 kg (BMI=49.1 kg/m2) with 87.2% of patients having a BMI≥40 kg/m2 and 12.4% with BMI≥60 kg/m2. The mean weight change of all patients enrolled was −4.1 kg (95% CI −3.6 to −4.6 kg, p=0.0001) at the end of SLiM, with completers (n=464) achieving −5.5 kg (95% CI −4.2 to −6.2 kg, p=0.0001) and non-completers achieving −2.3 kg (p=0.0001). The majority (78.6%) who attended the 6-month programme achieved weight loss with 32.3% achieving a ≥5% weight loss. Conclusions - The SLiM programme is an effective group intervention for the management of severe and complex obesity.
Resumo:
Purpose - To study how the threats of terrorism are being handled by a variety of UK companies in the travel and leisure sector in the UK in the post 9/11 era. Design/methodology/approach - A review of the literature of risk management in a world that is perceived to be more risky as a result of the terrorist attacks on the US on 11 September 2001 (9/11) is presented. Describes the application of theories of organizational resilience and institutions to frame an understanding of how managers make sense of terrorism risk and comprehend uncertainty. Reports a qualitative analysis of themes in interviews conducted with 25 managers from 6 unnamed organizations in the aviation industry (3 organizations) and the UK travel and leisure industry (3 organizations), representing a catering supplier, an airport, an airline, a tour company, a convention centre, and an arts and entertainment centre. Findings - The results indicated that the three organizations in the aviation industry prioritize threats from terrorism, whilst the three organizations in the leisure and travel sector do not, suggesting that the managers in the travel and leisure industry apply a probabilistic type of thinking and believe the likelihood of terrorism to be low. Reports that they give precedence to economic concerns and numerous other threats to the industry. Concludes that managers fall prey to the 'ludic fallacy', which conceives all odds as being calculable and hence managers conceive the terrorism risk as low while also expecting institutional factors to pre-empt and control terrorism threats, a reaction which the authors believe to be rather complacent and dangerous. Originality/value - Contributes to the research literature on risk management by revealing the gap in the ability of existing management tools and methodologies to deal with current and uncertain threats facing organizations due to terrorism.
Resumo:
As a means of benchmarking their position and assisting with anticipating an uncertain future, the identification of critical information systems (IS) management issues frameworks is becoming an increasingly important research task for both academics and industrialists. This paper provides a description and summary of previous work on identifying IS issues frameworks by reviewing 20 research investigations in terms of what they studied and how they were conducted. It also suggests some possible directions and methodologies for future research. The summary and suggestions for further work are applicable for issues framework research in the IS management field as well as in other business and management areas.
Resumo:
This paper reports on an aspect of the implementation of a sophisticated system of Casemix Budgeting within a large public hospital in New Zealand. The paper examines the role of accounting inscription in supporting a system of “remote” management control effected through the Finance function at the hospital. The paper provides detailed description and analysis of part of the casemix technology in use at the research site. The implementation of clinical budgeting through the Transition casemix system will be examined by describing an aspect of the casemix system in detail. The design and use of management reporting is described. Reporting to different levels of management and for differing parts of the organisation are discussed with particular emphasis on the adoption of traditional analysis of costs using standard costing and variance analysis techniques.
Resumo:
The nature of market orientation and its impact on business performance and other related outcomes have been extensively researched in a range of service contexts including tourism. In contrast, our understanding of the factors that influence market orientation is still limited. This paper reports on a study that contributes to our understanding of the determinants of market orientation within the tourism sector by focusing specifically on the role played by two strategically important variables, namely government regulation and ownership structure. The study analyses two national samples of hotels and travel services in the rapidly growing tourism industry in China. The hotel sector has been open to foreign investment for two decades and has a diversified ownership structure, whereas the travel services sector has been dominated by government owned firms and relatively closed to foreign investment. The results of the survey suggest that of the two new antecedents, only government regulation has a significant role to play in driving market orientation. Internally, access to appropriate managerial and marketing capabilities was identified as a significant predictor of the development of market orientation.
Resumo:
Translation plays an important role in the EU institutions. The description and explanation of the conditions of translation work and of the products of this work pose challenges to Translation Studies. For example, it needs to be tested whether traditional concepts do apply to the translation activity and its products, or whether modified or new concepts need to be introduced. Some of these concepts are reconsidered in view of the new contexts. Cross-references are made to the individual contributions in this issue which provide specific information.
Resumo:
This thesis is focussed on the role differentiationhypothesis as it relates to small groups (Bales, 1958). The hypothesis is systematically examined, both conceptually and empirically, in the light of the Equilibrium Hypothesis (Bales, 1953) and the Negotiated Order Theory of leadership (e.g. Hosking, 1988). Chapter 1 sketches in a context for the research,which was stimulated by attempts during the 60s and 70s to organise small groups without leaders (the leaderless group, based on isocratic principles). Chapter 2 gives a conceptual and developmental overview of Bales' work, concentrating on the Equilibrium Hypothesis. It is argued that Bales' conceptual approach, if developed, can potentially integrate the disparate small groups and leadership literatures. Chapters 3 and 4 examine the concepts `group', `leader' and `leadership' in terms of the Negotiated Order perspective. In chapter 3 it is argued that two aspects of the concept group need to be taken separately into account; physical attributes and social psychological aspects (the metaphysical glue). It is further argued that a collection of people becomes a group only when they begin to establish a shared sense of social order. In chapter 4 it is argued that leadership is best viewed as a process of negotiation between those who influence and those who are influenced, in the context of shared values about means and ends. It is further argued that leadership is the process by which a shared sense of social order is established and maintained, thus linking the concepts `leadership' and `group' in a single formulation. The correspondences with Bales' approach are discussed at the end of the chapter. Chapters 5 to 8 present a detailed critical description and evaluation of the empirical work which claims to show role differentiation or test the hypothesis, both Bales original work and subsequent studies. It is argued here, that the measurement and analytical procedures adopted by Bales and others, in particular the use of simple means as summaries of group structures, are fundamentally flawed, and that role differentiation in relation to particular identifiable groups has not been demonstrated clearly anywhere in the literature. Chapters 9 to 13 present the empirical work conducted for the thesis. 18 small groups are examined systematically for evidence of role differentiation using an approach based on early sociometry (Moreno, 1934). The results suggest that role differentiation, as described by Bales, does not occur as often as is implied in the literature, and not equivocally in any case. In particular structures derived from Liking are typically distributed or weak. This suggests that one of Bales' principal findings, that Liking varies independently of his other main dimensions, is the product of statistical artifact. Chapter 14 presents a general summary of results and presents some considerations about future research.
Resumo:
Advances in both computer technology and the necessary mathematical models capable of capturing the geometry of arbitarily shaped objects has led to the development in this thesis of a surface generation package called 'IBSCURF' aimed at providing a more economically viable solution to free-form surface manufacture. A suit of computer programs written in FORTRAN 77 has been developed to provide computer aids for every aspect of work in designing and machining free-form surfaces. A vector-valued parametric method was used for shape description and a lofting technique employed for the construction of the surface. The development of the package 'IBSCURF' consists of two phases. The first deals with CAD. The design process commences in defining the cross-sections which are represented by uniform B-spline curves as approximations to give polygons. The order of the curve and the position and number of the polygon vertices can be used as parameters for the modification to achieve the required curves. When the definitions of the sectional curves is complete, the surface is interpolated over them by cubic cardinal splines. To use the CAD function of the package to design a mould for a plastic handle, a mathematical model was developed. To facilitate the integration of design and machining using the mathematical representation of the surface, the second phase of the package is concerned with CAM which enables the generation of tool offset positions for ball-nosed cutters and a general post-processor has been developed which automatically generates NC tape programs for any CNC milling machine. The two phases of these programs have been successfully implemented, as a CAD/CAM package for free-form surfaces on the VAX 11/750 super-minicomputer with graphics facilities for displaying drawings interactively on the terminal screen. The development of this package has been beneficial in all aspects of design and machining of free form surfaces.
Resumo:
The Report of the Robens Committee (1972), the Health and Safety at Work Act (1974) and the Safety Representatives and Safety Committees Regulations (1977) provide the framework within which this study of certain aspects of health and safety is carried out. The philosophy of self-regulation is considered and its development is set within an historical and an industrial relations perspective. The research uses a case study approach to examine the effectiveness of self-regulation in health and safety in a public sector organisation. Within this approach, methodological triangulation employs the techniques of interviews, questionnaires, observation and documentary analysis. The work is based in four departments of a Scottish Local Authority and particular attention is given to three of the main 'agents' of self-regulation - safety representatives, supervisors and safety committees and their interactions, strategies and effectiveness. A behavioural approach is taken in considering the attitudes, values, motives and interactions of safety representatives and management. Major internal and external factors, which interact and which influence the effectiveness of joint self-regulation of health and safety, are identified. It is emphasised that an organisation cannot be studied without consideration of the context within which it operates both locally and in the wider environment. One of these factors, organisational structure, is described as bureaucratic and the model of a Representative Bureaucracy described by Gouldner (1954) is compared with findings from the present study. An attempt is made to ascertain how closely the Local Authority fits Gouldner's model. This research contributes both to knowledge and to theory in the subject area by providing an in-depth study of self-regulation in a public sector organisation, which when compared with such studies as those of Beaumont (1980, 1981, 1982) highlights some of the differences between the public and private sectors. Both empirical data and hypothetical models are used to provide description and explanation of the operation of the health and safety system in the Local Authority. As data were collected during a dynamic period in economic, political and social terms, the research discusses some of the effects of the current economic recession upon safety organisation.
Resumo:
The Semantic Web relies on carefully structured, well defined, data to allow machines to communicate and understand one another. In many domains (e.g. geospatial) the data being described contains some uncertainty, often due to incomplete knowledge; meaningful processing of this data requires these uncertainties to be carefully analysed and integrated into the process chain. Currently, within the SemanticWeb there is no standard mechanism for interoperable description and exchange of uncertain information, which renders the automated processing of such information implausible, particularly where error must be considered and captured as it propagates through a processing sequence. In particular we adopt a Bayesian perspective and focus on the case where the inputs / outputs are naturally treated as random variables. This paper discusses a solution to the problem in the form of the Uncertainty Markup Language (UncertML). UncertML is a conceptual model, realised as an XML schema, that allows uncertainty to be quantified in a variety of ways i.e. realisations, statistics and probability distributions. UncertML is based upon a soft-typed XML schema design that provides a generic framework from which any statistic or distribution may be created. Making extensive use of Geography Markup Language (GML) dictionaries, UncertML provides a collection of definitions for common uncertainty types. Containing both written descriptions and mathematical functions, encoded as MathML, the definitions within these dictionaries provide a robust mechanism for defining any statistic or distribution and can be easily extended. Universal Resource Identifiers (URIs) are used to introduce semantics to the soft-typed elements by linking to these dictionary definitions. The INTAMAP (INTeroperability and Automated MAPping) project provides a use case for UncertML. This paper demonstrates how observation errors can be quantified using UncertML and wrapped within an Observations & Measurements (O&M) Observation. The interpolation service uses the information within these observations to influence the prediction outcome. The output uncertainties may be encoded in a variety of UncertML types, e.g. a series of marginal Gaussian distributions, a set of statistics, such as the first three marginal moments, or a set of realisations from a Monte Carlo treatment. Quantifying and propagating uncertainty in this way allows such interpolation results to be consumed by other services. This could form part of a risk management chain or a decision support system, and ultimately paves the way for complex data processing chains in the Semantic Web.