890 resultados para Context Model
Resumo:
The paper presents a new theory for modeling flow in anisotropic, viscous rock. This theory has originally been developed for the simulation of large deformation processes including folding and kinking in multi-layered visco-elastic rock. The orientation of slip planes in the context of crystallographic slip is determined by the normal vector, the so-called director of these surfaces. The model is applied to simulate anisotropic natural mantle convection. We compare the evolution of the director and approximately steady states of isotropic and anisotropic convection. The isotropic case has a simple steady state solution, whereas the orthotropic convection model produces a continuously evolving patterning in tile core of the convection cell which makes only a near-steady condition possible, in which the thermal boundary layer appears to be well aligned with the flow and hence as observed in seismic tomomgraphy strong anistropic.
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Using the core aspects of five main models of human resource management (HRM), this article investigates the dominant HRM practices in the Indian manufacturing sector. The evaluation is conducted in the context of the recently liberalized economic environment. In response to ever-increasing levels of globalization of business, the article initially highlights the need for more cross-national comparative HRM research. Then it briefly analyzes the five models of HRM (namely, the `Matching model'; the `Harvard model'; the `Contextual model'; the `5-P model'; and the `European model') and identifies the main research questions emerging from these that could be used to reveal and highlight the HRM practices in different national/regional settings. The findings of the research are based on a questionnaire survey of 137 large Indian firms and 24 in-depth interviews in as many firms. The examination not only helped to present the scenario of HRM practices in the Indian context but also the logic dictating the presence of such practices. The article contributes to the fields of cross-national HRM and industrial relations research. It also has key messages for policy makers and opens avenues for further research.
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This paper is concerned with the effects that leadership styles (i.e., transactional and transformational) can have upon the level of front-line employees’ service delivery quality. Previous literature has mostly looked at leadership and its effects upon subordinates within a sales, psychology, or human resources context. However, due to the idiosyncrasies inherent in services (i.e., intangibility, heterogeneity, perishability, and inseparability), it is likely that, in such a context, different leadership styles will effect performance outcomes. Consequently, this paper seeks to expand the services marketing literature by developing a conceptual framework of leadership style effects adapted to the field of services marketing. Of particular importance are the effects that leadership styles have upon front-line employee “motivators” and service-related job outcomes. Specific hypotheses are developed and future research directions are also presented for consideration.
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When constructing and using environmental models, it is typical that many of the inputs to the models will not be known perfectly. In some cases, it will be possible to make observations, or occasionally physics-based uncertainty propagation, to ascertain the uncertainty on these inputs. However, such observations are often either not available or even possible, and another approach to characterising the uncertainty on the inputs must be sought. Even when observations are available, if the analysis is being carried out within a Bayesian framework then prior distributions will have to be specified. One option for gathering or at least estimating this information is to employ expert elicitation. Expert elicitation is well studied within statistics and psychology and involves the assessment of the beliefs of a group of experts about an uncertain quantity, (for example an input / parameter within a model), typically in terms of obtaining a probability distribution. One of the challenges in expert elicitation is to minimise the biases that might enter into the judgements made by the individual experts, and then to come to a consensus decision within the group of experts. Effort is made in the elicitation exercise to prevent biases clouding the judgements through well-devised questioning schemes. It is also important that, when reaching a consensus, the experts are exposed to the knowledge of the others in the group. Within the FP7 UncertWeb project (http://www.uncertweb.org/), there is a requirement to build a Webbased tool for expert elicitation. In this paper, we discuss some of the issues of building a Web-based elicitation system - both the technological aspects and the statistical and scientific issues. In particular, we demonstrate two tools: a Web-based system for the elicitation of continuous random variables and a system designed to elicit uncertainty about categorical random variables in the setting of landcover classification uncertainty. The first of these examples is a generic tool developed to elicit uncertainty about univariate continuous random variables. It is designed to be used within an application context and extends the existing SHELF method, adding a web interface and access to metadata. The tool is developed so that it can be readily integrated with environmental models exposed as web services. The second example was developed for the TREES-3 initiative which monitors tropical landcover change through ground-truthing at confluence points. It allows experts to validate the accuracy of automated landcover classifications using site-specific imagery and local knowledge. Experts may provide uncertainty information at various levels: from a general rating of their confidence in a site validation to a numerical ranking of the possible landcover types within a segment. A key challenge in the web based setting is the design of the user interface and the method of interacting between the problem owner and the problem experts. We show the workflow of the elicitation tool, and show how we can represent the final elicited distributions and confusion matrices using UncertML, ready for integration into uncertainty enabled workflows.We also show how the metadata associated with the elicitation exercise is captured and can be referenced from the elicited result, providing crucial lineage information and thus traceability in the decision making process.
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This work examines prosody modelling for the Standard Yorùbá (SY) language in the context of computer text-to-speech synthesis applications. The thesis of this research is that it is possible to develop a practical prosody model by using appropriate computational tools and techniques which combines acoustic data with an encoding of the phonological and phonetic knowledge provided by experts. Our prosody model is conceptualised around a modular holistic framework. The framework is implemented using the Relational Tree (R-Tree) techniques (Ehrich and Foith, 1976). R-Tree is a sophisticated data structure that provides a multi-dimensional description of a waveform. A Skeletal Tree (S-Tree) is first generated using algorithms based on the tone phonological rules of SY. Subsequent steps update the S-Tree by computing the numerical values of the prosody dimensions. To implement the intonation dimension, fuzzy control rules where developed based on data from native speakers of Yorùbá. The Classification And Regression Tree (CART) and the Fuzzy Decision Tree (FDT) techniques were tested in modelling the duration dimension. The FDT was selected based on its better performance. An important feature of our R-Tree framework is its flexibility in that it facilitates the independent implementation of the different dimensions of prosody, i.e. duration and intonation, using different techniques and their subsequent integration. Our approach provides us with a flexible and extendible model that can also be used to implement, study and explain the theory behind aspects of the phenomena observed in speech prosody.
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The thesis reports of a study into the effect upon organisations of co-operative information systems (CIS) incorporating flexible communications, group support and group working technologies. A review of the literature leads to the development of a model of effect based upon co-operative business tasks. CIS have the potential to change how co-operative business tasks are carried out and their principal effect (or performance) may therefore be evaluated by determining to what extent they are being employed to perform these tasks. A significant feature of CIS use identified is the extent to which they may be designed to fulfil particular tasks, or by contrast, may be applied creatively by users in an emergent fashion to perform tasks. A research instrument is developed using a survey questionnaire to elicit users judgements of the extent to which a CIS is employed to fulfil a range of co-operative tasks. This research instrument is applied to a longitudinal study of Novell GroupWise introduction at Northamptonshire County Council during which qualitative as well as quantitative data were gathered. A method of analysis of questionnaire results using principles from fuzzy mathematics and artificial intelligence is developed and demonstrated. Conclusions from the longitudinal study include the importance of early experiences in setting patterns for use for CIS, the persistence of patterns of use over time and the dominance of designed usage of the technology over emergent use.
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This dissertation studies the process of operations systems design within the context of the manufacturing organization. Using the DRAMA (Design Routine for Adopting Modular Assembly) model as developed by a team from the IDOM Research Unit at Aston University as a starting point, the research employed empirically based fieldwork and a survey to investigate the process of production systems design and implementation within four UK manufacturing industries: electronics assembly, electrical engineering, mechanical engineering and carpet manufacturing. The intention was to validate the basic DRAMA model as a framework for research enquiry within the electronics industry, where the initial IDOM work was conducted, and then to test its generic applicability, further developing the model where appropriate, within the other industries selected. The thesis contains a review of production systems design theory and practice prior to presenting thirteen industrial case studies of production systems design from the four industry sectors. The results and analysis of the postal survey into production systems design are then presented. The strategic decisions of manufacturing and their relationship to production systems design, and the detailed process of production systems design and operation are then discussed. These analyses are used to develop the generic model of production systems design entitled DRAMA II (Decision Rules for Analysing Manufacturing Activities). The model contains three main constituent parts: the basic DRAMA model, the extended DRAMA II model showing the imperatives and relationships within the design process, and a benchmark generic approach for the design and analysis of each component in the design process. DRAMA II is primarily intended for use by researchers as an analytical framework of enquiry, but is also seen as having application for manufacturing practitioners.
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Frontline employee (FLE) attitudes and behaviours during service encounters influence customers’ perceptions of service quality and customer satisfaction. The identification of variables that influence FLEs service behaviours is, therefore, important. Much remains unknown about the factors affecting prosocial service behaviours (PSBs). This thesis answers the following questions: What are the antecedents of PSBs in a travel service setting? It is argued that managerial strategies indirectly influence PSBs via their direct influence on job attitudes. This thesis represents an attempt towards an increased knowledge about the antecedents of PSBs by seeking answers to the question. A conceptual model was developed from the literature. Briefly stated, the hypothesised model proposed that job attitudes mediate the relationship between managerial strategies and the PSBs. In-depth interviews provided initial support for the conceptual model. Structural equation modelling techniques were then used to test these relationships on data from 179 travel service employees. Partial support for the mediational role of job attitudes was found. More specifically, the relationship between professional development and extra-role customer service is mediated by job satisfaction and organisational commitment, but not in-role customer service and cooperation. The managerial strategies influence PSBs directly. Internal communication influences extra- and in-role customer service behaviours positively. The relationship between professional development and the three PSBs constructs is negative. Empowerment influences in-role customer service and cooperative behaviours positively.
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Market oriented behaviours have been found to be important predictors of business success across a wide array of studies. Despite their potential importance, research into market oriented behaviours in the joint venture (JV) context is very scarce. This study represents a novel attempt to address this gap by examining a set of antecedent factors which arises from sources outside a traditional firm’s boundary. An extensive review and synthesis of the market orientation and JV literature yielded a set of context-specific antecedent factors relevant to the JV’s relational context. In accordance with the perspective offered by the transaction cost theory, a system of hypotheses about the effects of these antecedent factors on JV’s market oriented behaviours was developed. In order to test these hypotheses, empirical evidence was collected by means of a mail survey to international joint ventures operating in the coastal regions of mainland China. A sample of 191 JV firms was collected as a result. Following well established procedures for scale development and purification as recommended in the methodology literature, the scales were critically trimmed and reviewed for their psychometric properties. The conceptual model was tested with a structural equation model. Results suggested that a number of context-specific antecedents are in fact important determinants of JVs’ level of market oriented behaviours. In addition, the linkage between market oriented behaviours and market performance was also successfully established.
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Differential perception of innovation is a research area which has been advocated as a suitable topic for study in recent years. It developed from the problems encountered within earlier perception of innovation studies which sought to establish what characteristics of an innovation affected the ease of its adoption. While some success was achieved In relating perception of innovation to adoption behaviour, variability encountered Within groups expected - to fercelve innovation similarly suggested that the needs and experiences of the potential adopter were significantly affecting the research findings. Such analysis being supported by both sociological and psychological perceptual research. The present study sought to identify the presence of differential perception of innovation and explore the nature of the process. It was decided to base the research in an organisational context and to concentrate upon manufacturing innovation. It has been recognised that such adoption of technological innovation is commonly the product of a collective decision-making process, involving individuals from a variety of occupational backgrounds, both in terms of occupational speciality and level within the hierarchy. Such roles appeared likely to significantly influence perception of technological innovation, as gathered through an appropriate measure and were readily identifiable. Data vas collected by means of a face-to-face card presentation technique, a questionnaire and through case study material. Differential perception of innovation effects were apparent In the results, many similarities and differences of perception being related to the needs and experiences of the individuals studied. Phenomenological analysis, which recognises the total nature of experience in infiuencing behaviour, offered the best means of explaining the findings. It was also clear that the bureaucratic model of role definition was not applicable to the area studied, it seeming likely that such definitions are weaker under conditions of uncertainty, such as encountered in innovative decision-making.
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This thesis, set within an Action Research framework, details the development and validation of a writer-centred model of the writing process. The model was synthesised within the boundaries of a writers’ group for MA students. The initial data collected, and analysed using the principles of grounded theory, were retrospective descriptions of group members’ writing processes. After initial analysis, additional data, from group members’ writing, and from audio recordings, were used for further analysis, and to form a model of the writing process. To ascertain whether the model had value outside the specific context in which it was made, it was validated from three different perspectives. Firstly, the retrospective descriptions of other writers were collected and analysed, using the model as a framework. Secondly, the model was presented at academic conferences; comments about the model, made by members of the audience, were collected and analysed. Finally, the model was used in writing courses for PhD students. Comments from these students, along with questionnaire responses, were collected and the content analysed. Upon examination of all data sources, the model was updated to reflect additional insights arising from the analysis. Analysis of the data also indicated that the model is useable outside its original context. Potential uses for the model are 1) raising awareness of the process of writing, 2) putting writers at ease, 3) serving as a starting point for individuals or groups to design their own models of the writing process, and 4) as a tool to help writers take control of their writing processes.
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We used cultural self-representation theory to develop a model of the processes linking delegation to work outcomes. We tested this model with data from a sample of 171 subordinate-supervisor dyads from the People's Republic of China. Regression results revealed that organization-based self-esteem and perceived insider status fully mediated the influence of delegation on affective organizational commitment, task performance, and innovative behavior and partially mediated delegation's influence on job satisfaction. Furthermore, traditionality moderated the relationships between delegation and the mediators in such a way that the relationships were stronger for individuals lower rather than higher in traditionality. © Academy of Management Journal.
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Objective: Biomedical events extraction concerns about events describing changes on the state of bio-molecules from literature. Comparing to the protein-protein interactions (PPIs) extraction task which often only involves the extraction of binary relations between two proteins, biomedical events extraction is much harder since it needs to deal with complex events consisting of embedded or hierarchical relations among proteins, events, and their textual triggers. In this paper, we propose an information extraction system based on the hidden vector state (HVS) model, called HVS-BioEvent, for biomedical events extraction, and investigate its capability in extracting complex events. Methods and material: HVS has been previously employed for extracting PPIs. In HVS-BioEvent, we propose an automated way to generate abstract annotations for HVS training and further propose novel machine learning approaches for event trigger words identification, and for biomedical events extraction from the HVS parse results. Results: Our proposed system achieves an F-score of 49.57% on the corpus used in the BioNLP'09 shared task, which is only 2.38% lower than the best performing system by UTurku in the BioNLP'09 shared task. Nevertheless, HVS-BioEvent outperforms UTurku's system on complex events extraction with 36.57% vs. 30.52% being achieved for extracting regulation events, and 40.61% vs. 38.99% for negative regulation events. Conclusions: The results suggest that the HVS model with the hierarchical hidden state structure is indeed more suitable for complex event extraction since it could naturally model embedded structural context in sentences.
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Constructing and executing distributed systems that can adapt to their operating context in order to sustain provided services and the service qualities are complex tasks. Managing adaptation of multiple, interacting services is particularly difficult since these services tend to be distributed across the system, interdependent and sometimes tangled with other services. Furthermore, the exponential growth of the number of potential system configurations derived from the variabilities of each service need to be handled. Current practices of writing low-level reconfiguration scripts as part of the system code to handle run time adaptation are both error prone and time consuming and make adaptive systems difficult to validate and evolve. In this paper, we propose to combine model driven and aspect oriented techniques to better cope with the complexities of adaptive systems construction and execution, and to handle the problem of exponential growth of the number of possible configurations. Combining these techniques allows us to use high level domain abstractions, simplify the representation of variants and limit the problem pertaining to the combinatorial explosion of possible configurations. In our approach we also use models at runtime to generate the adaptation logic by comparing the current configuration of the system to a composed model representing the configuration we want to reach. © 2008 Springer-Verlag Berlin Heidelberg.
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Engineering adaptive software is an increasingly complex task. Here, we demonstrate Genie, a tool that supports the modelling, generation, and operation of highly reconfigurable, component-based systems. We showcase how Genie is used in two case-studies: i) the development and operation of an adaptive flood warning system, and ii) a service discovery application. In this context, adaptation is enabled by the Gridkit reflective middleware platform.