4,344 research outputs found
Computer considerations for real time simulation of a generalized rotor model
Scaled equations were developed to meet requirements for real time computer simulation of the rotor system research aircraft. These equations form the basis for consideration of both digital and hybrid mechanization for real time simulation. For all digital simulation estimates of the required speed in terms of equivalent operations per second are developed based on the complexity of the equations and the required intergration frame rates. For both conventional hybrid simulation and hybrid simulation using time-shared analog elements the amount of required equipment is estimated along with a consideration of the dynamic errors. Conventional hybrid mechanization using analog simulation of those rotor equations which involve rotor-spin frequencies (this consititutes the bulk of the equations) requires too much analog equipment. Hybrid simulation using time-sharing techniques for the analog elements appears possible with a reasonable amount of analog equipment. All-digital simulation with affordable general-purpose computers is not possible because of speed limitations, but specially configured digital computers do have the required speed and consitute the recommended approach
Subventricular zone stem cells are heterogeneous with respect to their embryonic origins and neurogenic fates in the adult olfactory bulb
Wedetermined the embryonic origins of adult forebrain subventricular zone (SVZ) stem cells by Cre-lox fate mapping in transgenic mice. We found that all parts of the telencephalic neuroepithelium, including the medial ganglionic eminence and lateral ganglionic eminence (LGE) and the cerebral cortex, contribute multipotent, self-renewing stem cells to the adult SVZ. Descendants of the embryonic LGE and cortex settle in ventral and dorsal aspects of the dorsolateral SVZ, respectively. Both populations contribute new (5-bromo-2(')-deoxyuridine- labeled) tyrosine hydroxylase- and calretinin-positive interneurons to the adult olfactory bulb. However, calbindin-positive interneurons in the olfactory glomeruli were generated exclusively by LGE- derived stem cells. Thus, different SVZ stem cells have different embryonic origins, colonize different parts of the SVZ, and generate different neuronal progeny, suggesting that some aspects of embryonic patterning are preserved in the adult SVZ. This could have important implications for the design of endogenous stem cell-based therapies in the future
Assessing intonation skills in a tertiary music training programme
[Abstract]: Buttsworth, Fogarty, and Rorke (1993) reported the construction of a battery of tonal
tests designed to assess intonation abilities. A subset of the tests in the battery
predicted 36 per cent of final scores in an aural training subject in a tertiary music course. In
the current study, the original battery of fourteen tests was reduced to six tests and
administered three times throughout the academic year to a new sample (N = 87) of
tertiary music students. Three research questions were investigated. Firstly, it was
hypothesised that tests in the battery would discriminate among the different aural
classes at USQ, which were grouped according to ability level. The results from
discriminant function analyses provided strong support for this hypothesis. Secondly,
it was hypothesised that students should improve their performance on the pitch
battery across the three administrations. A repeated measures analysis of variance
failed to find evidence of overall improvement. Finally, it was hypothesised that there
would be significant differences on the intonation tests between musicians of different
instrumental families. Again, no overall differences were found. The results indicated
that intonation tests appear to tap an ability that (a) is not significantly modified by
training, (b) is more or less the same across different instrument families, and (c) is
related to success in music training programmes
Orthogonality catastrophe as a consequence of qubit embedding in an ultra-cold Fermi gas
We investigate the behaviour of a single qubit coupled to a low-dimensional,
ultra-cold Fermi gas. The scattering between the system and the fermions leads
to the loss of any coherence in the initial state of the qubit and we show that
the exact dynamics of this process is strongly influenced by the effect of the
orthogonality catastrophe within the gas. We highlight the relationship between
the Loschmidt echo and the retarded Green's function - typically used to
formulate the dynamical theory of the catastrophe - and demonstrate that the
effect can be triggered and characterized via local operations on the qubit. We
demonstrate how the expected broadening of the spectral function can be
observed using Ramsey interferometry on the qubit.Comment: 4 and a bit pages, 3 figures. Updated versio
Predicting employees' commitment to and support for organisational change
This study aimed to identify factors that predict employees' commitment to and support for organisational change. The three components of Herscovitch and Meyer's (2002) commitment to organisational change model were hypothesised to mediate the relationship between organisational climate and behavioural support for organisational change. Data were collected from a Queensland government department (N = 342). Analysis of correlations revealed that organisational climate, commitment to change, and behavioural support for change variables were all significantly related. Structural equation modelling demonstrated that affective, normative, and continuance commitment to change were all predictors of behavioural support for organisational change. Positive work climate also contributed directly to the prediction of behavioural support for change over and above the indirect influence through commitment to organisational change, indicating a partial mediation effect. These findings support Herscovitch and Meyer's (2002) three-component model of commitment to organisational change and extend their nomological network by showing the relevance of two types of organisational climate to the core components of the model. Affective commitment to organisational change is a positive influence on employees' behavioural support for change and also reflects healthy aspects of the organisational climate. However, continuance commitment to organisational change is detrimental influence on employees' behavioural support for change and is linked with unhealthy dimensions of the organisational climate
Nuclear fragmentation studies for microelectronic application
A formalism for target fragment transport is presented with application to energy loss spectra in thin silicon devices. Predicted results are compared to experiments with the surface barrier detectors of McNulty et al. The intranuclear cascade nuclear reaction model does not predict the McNulty experimental data for the highest energy events. A semiempirical nuclear cross section gives an adequate explanation of McNulty's experiments. Application of the formalism to specific electronic devices is discussed
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