911 resultados para sensory drive
Resumo:
This paper explores tariff reform in Ethiopia, Kenya, Tanzania and Uganda between the early 1990s and early 2000s. Tariffs were reformed in an across the board manner consistent with implementing World Bank programs: the average tariff was reduced and the dispersion of tariffs was compressed, with the highest tariffs being eliminated. There is limited evidence of political economy influences on the cross sector pattern of tariffs and reforms, except for a tendency to offer greater protection to larger manufacturing sectors in all countries except Uganda. The technocratic reforms have diluted relative protection and political economy influences in all the four countries.
Resumo:
This thesis looks at the UK onshore oil and gas production industry and follows the history of a population of firms over a fifteen-year period following the industry's renaissance. It examines the linkage between firm survival, selection pressures and adaptation responses at the firm level, especially the role of discretionary adaptation, specifically exploration and exploitation strategies.Taking a Realist approach and using quantitative and qualitative methods for triangulation on a new data base derived from archival data, as well as informant interviews, it tests seven hypotheses' about post-entry survival of firms. The quantitative findings suggest that firm survival within this industry is linked to discretionary adaptation, when measured at the firm level, and to a mixture of selection and adaptation forces when measured for each firm for each individual year. The qualitative research suggests that selection factors dominate. This difference in views is unresolved. However the small, sparse population and the nature of the oil and gas industry compared with other common research contexts such as manufacturing or service firms suggests the results be treated with caution as befits a preliminary investigation. The major findings include limited support for the theory that the external environment is the major determinant of firm survival, though environment components affect firms differentially; resolution of apparent literature differences relating to the sequencing of exploration and exploitation and potential tangible evidence of coevolution. The research also finds that, though selection may be considered important by industry players, discretionary adaptation appears to play the key role, and that the key survival drivers for thispopulation are intra-industry ties, exploitation experience and a learning/experience component. Selection has a place, however, in determining the life-cycle of the firm returning to be a key survival driver at certain ages of the firm inside the industry boundary.
Resumo:
A simple and cost-effective technique for generating a flat, square-shaped multi-wavelength optical comb with 42.6 GHz line spacing and over 0.5 THz of total bandwidth is presented. A detailed theoretical analysis is presented, showing that using two concatenated modulators driven with voltages of 3.5 Vp are necessary to generate 11 comb lines with a flatness below 2dB. This performance is experimentally demonstrated using two cascaded Versawave 40 Gbit/s low drive voltage electro-optic polarisation modulators, where an 11 channel optical comb with a flatness of 1.9 dB and a side-mode-suppression ratio (SMSR) of 12.6 dB was obtained.
Resumo:
The present study examines whether parental reports of child selective eating are associated with child anxiety and sensitivity to sensory stimuli in their environment. Parents of 95 children aged 5-10 completed questionnaires about child eating behavior, child anxiety and sensory sensitivity. Results indicated that both anxiety and sensory sensitivity were associated with selective eating. In addition, child sensory sensitivity fully mediated the relationship between anxiety and selective eating in children suggesting that it is greater sensitivity to sensory information which explains why more anxious children are more likely to be selective eaters. Further research is necessary to better understand these relationships and indicate whether gradual exposure interventions with children who are sensory sensitive may help to prevent or reduce selective eating. © 2012 Elsevier Ltd.
Resumo:
Sensory processing is a crucial underpinning of the development of social cognition, a function which is compromised in variable degree in patients with pervasive developmental disorders (PDD). In this manuscript, we review some of the most recent and relevant contributions, which have looked at auditory sensory processing derangement in PDD. The variability in the clinical characteristics of the samples studied so far, in terms of severity of the associated cognitive deficits and associated limited compliance, underlying aetiology and demographic features makes a univocal interpretation arduous. We hypothesise that, in patients with severe mental deficits, the presence of impaired auditory sensory memory as expressed by the mismatch negativity could be a non-specific indicator of more diffuse cortical deficits rather than causally related to the clinical symptomatology. More consistent findings seem to emerge from studies on less severely impaired patients, in whom increased pitch perception has been interpreted as an indicator of increased local processing, probably as compensatory mechanism for the lack of global processing (central coherence). This latter hypothesis seems extremely attractive and future trials in larger cohorts of patients, possibly standardising the characteristics of the stimuli are a much-needed development. Finally, specificity of the role of the auditory derangement as opposed to other sensory channels needs to be assessed more systematically using multimodal stimuli in the same patient group. (c) 2006 Elsevier B.V. All rights reserved.
Resumo:
Presented is a study on a single-drive dual-parallel Mach-Zehnder modulator implementation as a single sideband suppressed carrier generator. High values of both extinction ratio and sidemode suppression ratio were obtained at different modulation frequencies over the Cband. In addition, a stabilisation loop had been developed to preserve the single sideband generation over time. © The Institution of Engineering and Technology 2013.
Resumo:
Detection thresholds for two visual- and two auditory-processing tasks were obtained for 73 children and young adults who varied broadly in reading ability. A reading-disabled subgroup had significantly higher thresholds than a normal-reading subgroup for the auditory tasks only. When analyzed across the whole group, the auditory tasks and one of the visual tasks, coherent motion detection, were significantly related to word reading. These effects were largely independent of ADHD ratings; however, none of these measures accounted for significant variance in word reading after controlling for full-scale IQ. In contrast, phoneme awareness, rapid naming, and nonword repetition each explained substantial, significant word reading variance after controlling for IQ, suggesting more specific roles for these oral language skills in the development of word reading. © 2004 Elsevier Inc. All rights reserved.
Resumo:
Synchronous reluctance motors (SynRMs) are gaining in popularity in industrial drives due to their permanent magnet-free, competitive performance, and robust features. This paper studies the power losses in a 90-kW converter-fed SynRM drive by a calorimetric method in comparison of the traditional input-output method. After the converter and the motor were measured simultaneously in separate chambers, the converter was installed inside the large-size chamber next to the motor and the total drive system losses were obtained using one chamber. The uncertainty of both measurement methods is analyzed and discussed.
Resumo:
To carry out stability studies on more electric systems in which there is a preponderance of motor drive equipment, input admittance expressions are required for the individual pieces of equipment. In this paper the techniques of averaging and small-signal linearisation will be used to derive a simple input admittance model for a low voltage, trapezoidal back EMF, brushless, DC motor drive system.
Resumo:
Astrocytes respond to chemical, electrical and mechanical stimuli with transient increases in intracellular calcium concentration ([Ca2+]i). We now show that astrocytes in situ display intrinsic [Ca2+]i oscillations that are not driven by neuronal activity. These spontaneous astrocytic oscillations can propagate as waves to neighboring astrocytes and trigger slowly decaying NMDA receptor-mediated inward currents in neurons located along the wave path. These findings show that astrocytes in situ can act as a primary source for generating neuronal activity in the mammalian central nervous system.
Resumo:
A simple and cost-effective technique for generating a flat, square-shaped multi-wavelength optical comb with 42.6 GHz line spacing and over 0.5 THz of total bandwidth is presented. A detailed theoretical analysis is presented, showing that using two concatenated modulators driven with voltages of 3.5 Vp are necessary to generate 11 comb lines with a flatness below 2dB. This performance is experimentally demonstrated using two cascaded Versawave 40 Gbit/s low drive voltage electro-optic polarisation modulators, where an 11 channel optical comb with a flatness of 1.9 dB and a side-mode-suppression ratio (SMSR) of 12.6 dB was obtained.
Resumo:
This paper explores the design, development and evaluation of a novel real-time auditory display system for accelerated racing driver skills acquisition. The auditory feedback provides concurrent sensory augmentation and performance feedback using a novel target matching design. Real-time, dynamic, tonal audio feedback representing lateral G-force (a proxy for tire slip) is delivered to one ear whilst a target lateral G-force value representing the ‘limit’ of the car, to which the driver aims to drive, is panned to the driver’s other ear; tonal match across both ears signifies that the ‘limit’ has been reached. An evaluation approach was established to measure the efficacy of the audio feedback in terms of performance, workload and drivers’ assessment of self-efficacy. A preliminary human subject study was conducted in a driving simulator environment. Initial results are encouraging, indicating that there is potential for performance gain and driver confidence enhancement based on the audio feedback.
Resumo:
This study examined the relations between anxiety and individual characteristics of sensory sensitivity (SS) and intolerance of uncertainty (IU) in mothers of children with ASD. The mothers of 50 children completed the Hospital Anxiety and Depression Scale, the Highly Sensitive Person Scale and the IU Scale. Anxiety was associated with both SS and IU and IU was also associated with SS. Mediation analyses showed direct effects between anxiety and both IU and SS but a significant indirect effect was found only in the model in which IU mediated between SS. This is the first study to characterize the nature of the IU and SS interrelation in predicting levels of anxiety.