908 resultados para PMD Link Coefficient
Resumo:
Final report evaluating the impact of Business Link local services on those businesses that received assistance in the 6 month period April to September 2003 and its impact over the subsequent period to May/June 2005"--BERR website (Reports & Publications).
Resumo:
Recent years have witnessed a significant degree of administrative reform, in terms of the increasing number of major companies proclaiming their social responsibility credentials, and backing up their claims by producing substantial environmental, social and sustainability reports. The paper critically evaluates the degree of institutional reform, designed to empower stakeholders, and thereby enhance corporate accountability, accompanying these voluntary initiatives, together with that potentially ensuing from proposed regulations, later rescinded, for mandatory publication of an Operating and Financial Review by UK quoted companies. It is concluded that both forms of disclosure offer little in the way of opportunity for facilitating action on the part of organizational stakeholders, and cannot therefore be viewed as exercises in accountability. © 2007 Elsevier Ltd. All rights reserved.
Resumo:
The provision of advisory support to small firms is almost ubiquitous in OECD countries, although it is organised in different ways and is justified on slightly different grounds. In England publicly supported advisory services are provided through the Business Link (BL) network. Here, we consider two questions: what sort of companies receive advisory support from BL; and, what types of firms benefit most from that support? Our analysis is based on a telephone survey of 2000 firms, around half of which had received intensive assistance from BL between April and October 2003. Probit analysis suggests that the probability of receiving assistance was greater among younger businesses, those with larger numbers of directors in the firm, and those with more gender diversity among the firm's leadership team. Our business-growth models suggest that BL intensive assistance was having a positive effect on employment growth in 2003. BL had a positive but insignificant impact on sales growth over the period. Employment growth effects tend to be larger where firms have a management and organisational structure, which is more conducive to absorbing and making use of external advice. The analysis suggests that BL might increase its impact through targeting these larger, more export-orientated, businesses. Employment growth effects differ little, however, depending on either the ethnic or the gender diversity of the leadership team.
Resumo:
Purpose - This paper provides a deeper examination of the fundamentals of commonly-used techniques - such as coefficient alpha and factor analysis - in order to more strongly link the techniques used by marketing and social researchers to their underlying psychometric and statistical rationale. Design/methodology approach - A wide-ranging review and synthesis of psychometric and other measurement literature both within and outside the marketing field is used to illuminate and reconsider a number of misconceptions which seem to have evolved in marketing research. Findings - The research finds that marketing scholars have generally concentrated on reporting what are essentially arbitrary figures such as coefficient alpha, without fully understanding what these figures imply. It is argued that, if the link between theory and technique is not clearly understood, use of psychometric measure development tools actually runs the risk of detracting from the validity of the measures rather than enhancing it. Research limitations/implications - The focus on one stage of a particular form of measure development could be seen as rather specialised. The paper also runs the risk of increasing the amount of dogma surrounding measurement, which runs contrary to the spirit of this paper. Practical implications - This paper shows that researchers may need to spend more time interpreting measurement results. Rather than simply referring to precedence, one needs to understand the link between measurement theory and actual technique. Originality/value - This paper presents psychometric measurement and item analysis theory in easily understandable format, and offers an important set of conceptual tools for researchers in many fields. © Emerald Group Publishing Limited.
Resumo:
The relationship between human resource management practices and organizational performance (including quality of care in health-care organizations) is an important topic in the organizational sciences but little research has been conducted examining this relationship in hospital settings. Human resource (HR) directors from sixty-one acute hospitals in England (Hospital Trusts) completed questionnaires or interviews exploring HR practices and procedures. The interviews probed for information about the extensiveness and sophistication of appraisal for employees, the extent and sophistication of training for employees and the percentage of staff working in teams. Data on patient mortality were also gathered. The findings revealed strong associations between HR practices and patient mortality generally. The extent and sophistication of appraisal in the hospitals was particularly strongly related, but there were links too with the sophistication of training for staff, and also with the percentages of staff working in teams.
Resumo:
Behavioural studies on normal and brain-damaged individuals provide convincing evidence that the perception of objects results in the generation of both visual and motor signals in the brain, irrespective of whether or not there is an intention to act upon the object. In this paper we sought to determine the basis of the motor signals generated by visual objects. By examining how the properties of an object affect an observer's reaction time for judging its orientation, we provide evidence to indicate that directed visual attention is responsible for the automatic generation of motor signals associated with the spatial characteristics of perceived objects.
Resumo:
Recent animal studies highlighting the relationship between functional imaging signals and the underlying neuronal activity have revealed the potential capabilities of non-invasive methods. However, the valuable exchange of information between animal and human studies remains restricted by the limited evidence of direct physiological links between species. In this study we used magnetoencephalography (MEG) to investigate the occurrence of 30-70 Hz (gamma) oscillations in human visual cortex, induced by the presentation of visual stimuli of varying contrast. These oscillations, well described in the animal literature, were observed in retinotopically concordant locations of visual cortex and show striking similarity to those found in primate visual cortex using surgically implanted electrodes. The amplitude of the gamma oscillations increases linearly with stimulus contrast in strong correlation with the gamma oscillations found in the local field potential (LFP) of the macaque. We demonstrate that non-invasive magnetic field measurements of gamma oscillations in human visual cortex concur with invasive measures of activation in primate visual cortex, suggesting both a direct representation of underlying neuronal activity and a concurrence between human and primate cortical activity. © 2005 Elsevier Inc. All rights reserved.
Resumo:
A novel direct integration technique of the Manakov-PMD equation for the simulation of polarisation mode dispersion (PMD) in optical communication systems is demonstrated and shown to be numerically as efficient as the commonly used coarse-step method. The main advantage of using a direct integration of the Manakov-PMD equation over the coarse-step method is a higher accuracy of the PMD model. The new algorithm uses precomputed M(w) matrices to increase the computational speed compared to a full integration without loss of accuracy. The simulation results for the probability distribution function (PDF) of the differential group delay (DGD) and the autocorrelation function (ACF) of the polarisation dispersion vector for varying numbers of precomputed M(w) matrices are compared to analytical models and results from the coarse-step method. It is shown that the coarse-step method achieves a significantly inferior reproduction of the statistical properties of PMD in optical fibres compared to a direct integration of the Manakov-PMD equation.
Resumo:
The phenomenon of low-PMD fibres is examined through numerical simulations. Instead of the coarse-step method we are using an algorithm developed through the Manakov-PMD equation. With the integration of the Manakov-PMD equation we have access to the fibre spin which relates to the orientation of the birefringence. The simulation results produced correspond to the behaviour of a low-PMD spun fibre. Furthermore we provide an analytical approximation compared to the numerical data. © 2005 Optical Society of America.
Resumo:
Measurements were carried out to determine local coefficients of heat transfer in short lengths of horizontal pipe, and in the region of an discontinuity in pipe diameter. Laminar, transitional and turbulent flow regimes were investigated, and mixtures of propylene glycol and water were used in the experiments to give a range of viscous fluids. Theoretical and empirical analyses were implemented to find how the fundamental mechanism of forced convection was modified by the secondary effects of free convection, temperature dependent viscosity, and viscous dissipation. From experiments with the short tube it was possible to determine simple empirical relationships describing the axial distribution of the local 1usselt number and its dependence on the Reynolds and Prandtl numbers. Small corrections were made to account for the secondary effects mentioned above. Two different entrance configurations were investigated to demonstrate how conditions upstream could influence the heat transfer coefficients measured downstream In experiments with a sudden contraction in pipe diameter the distribution of local 1u3se1t number depended on the Prandtl number of the fluid in a complicated way. Graphical data is presented describing this dependence for a range of fluids indicating how the local Nusselt number varied with the diameter-ratio. Ratios up to 3.34:1 were considered. With a sudden divergence in pipe diameter, it was possible to derive the axial distribution of the local Nusse1t number for a range of Reynolds and Prandtl numbers in a similar way to the convergence experiments. Difficulty was encountered in explaining some of the measurements obtained at low Reynolds numbers, and flow visualization techniques wore used to determine the complex flow patterns which could lead to the anomalous results mentioned. Tests were carried out with divergences up to 1:3.34 to find the way in which the local Nusselt number varied with the diameter ratio, and a few experiments were carried out with very large ratios up .to 14.4. A limited amount of theoretical analysis of the 'divergence' system was carried out to substantiate certain explanations of the heat transfer mechanisms postulated.
Resumo:
Both proteolysis-inducing factor (PIF) and angiotensin II have been shown to produce a depression in protein synthesis in murine myotubes concomitant with an increased phosphorylation of eukaryotic initiation factor 2 (eIF2α). Both PIF and angiotensin II were shown to induce autophosphorylation of the RNA-dependent protein kinase (PKR), and an inhibitor of this enzyme completely attenuated the depression in protein synthesis and prevented the induction of eIF2α phosphorylation. The PKR inhibitor also completely attenuated the increase in protein degradation induced by PIF and angiotensin II and prevented the increase in proteasome expression and activity. To confirm these results myotubes were transfected with plasmids that express either wild-type PKR, or a catalytically inactive PKR variant, PKRΔ6. Myotubes expressing PKRΔ6 showed no increase in eIF2α phosphorylation in response to PIF or angiotensin II, no depression in protein synthesis, and no increase in protein degradation or increase in proteasome expression. Induction of the ubiquitin-proteasome pathway by PIF and angiotensin II has been linked to activation of the transcription factor nuclear factor-κB (NF-κB). Inhibition of PKR prevented nuclear migration of NF-κB in response to both PIF and angiotensin II, by preventing degradation of the inhibitor protein I-κB. Phosphorylation of PKR and eIF2α was also significantly increased in the gastrocnemius muscle of weight losing mice bearing the MAC16 tumor, suggesting that a similar process may be operative in cancer cachexia. These results provide a link between the depression of protein synthesis in skeletal muscle and the increase in protein degradation. © 2007 by The American Society for Biochemistry and Molecular Biology, Inc.