Showing papers by "University of Newcastle published in 1985"
TL;DR: In this article, the authors describe a series of studies that collectively explicate the development and role of metalearning in the learning and study processes of secondary and tertiary students.
Abstract: Summary. Effective learning under institutional conditions requires, first, that students are aware of task demands and of their intentions of how, or even whether, to meet those demands, and, second, that they assess realistically, and exert control over, their own cognitive resources. The fulfilment of such conditions involves a sophisticated kind of metacognition, here called metalearning. The present paper describes a series of studies that collectively explicate the development and role of metalearning in the learning and study processes of secondary and tertiary students. Ability patterns, locus of control, variety and quality of certain non-school experiences, and extent and kind of motivation all seem to be involved in the development of metalearning capability. A model of student learning is then described, in which personal and situational factors are linked to performance by three main approaches to learning: deep, achieving, and surface. These approaches involve varying degrees of metalearning and lead to qualitatively different learning outcomes. An intervention study on improving student learning is described that tests important aspects of the model, and further implications for teaching and research are suggested.
507 citations
TL;DR: In this paper, a cell in which bubbles of known size could be generated independently of the turbulence levels, which could be controlled by varying the impeller speed, and it was found that the flotation rate was very strongly affected by the bubble size, there being an increase of up to one hundred-fold when reduced from 655 μm to 75 μm.
297 citations
TL;DR: In this article, a theoretical model of the determination of trading bank interest margins, based on the hedging theory of interest margin determination, is tested on time series cross-section data of Australian trading banks.
Abstract: A theoretical model of the determination of trading bank interest margins, based on the hedging theory of interest margin determination, is tested on time series cross-section data of Australian trading banks. Generally, the results are consistent with that theory. That is, there exists a stable non-linear relationship between Australian trading bank net loan/deposit interest margins and measures of market power, degree of absolute risk aversion, and to interest rate uncertainty. Furthermore, the shift from business sector to personal sector loan and deposit business is associated with increased bank interest margins.
224 citations
TL;DR: A mathematical model of some of the important features of the growth of corneal limbal vessels is described and it is suggested that the model might form the framework for further theoretical work on related phenomena such as wound healing or to develop strategies for the investigation of anti-angiogenesis.
218 citations
TL;DR: The role of competing chemical equilibria has been considered, through discussion of chemical interactions involving fluoride species and soil components such as clays, hydrous oxides (Al, Fe, Mn), organic matter, calcite and quartz.
183 citations
TL;DR: In this paper, an indirect adaptive control scheme for deterministic plants which are not necessarily minimum phase is presented, where the closed-loop poles are asymptotically assigned for the given data sequence and the system input and output remain bounded for all time.
Abstract: This paper presents an indirect adaptive control scheme for deterministic plants which are not necessarily minimum phase. Global convergence is established for the scheme in the sense that the closed-loop poles are asymptotically assigned for the given data sequence and the system input and output remain bounded for all time. A key feature of the scheme is that no persistency of excitation condition is required. The algorithm uses recursive least squares with variable forgetting factor, normalized regression vectors, and a matrix gain with constant trace.
146 citations
TL;DR: The problem of colouring the real line so that the distance between like coloured numbers does not lie in some specified set D, called the distance set, is discussed.
101 citations
TL;DR: In this article, the fundamental mathematical questions of convergence and uniqueness of the sum of these, not absolutely convergent, series are considered, and it is shown that some simple direct sum methods converge and some do not converge.
Abstract: The lattice sums involved in the definition of Madelung’s constant of an NaCl‐type crystal lattice in two or three dimensions are investigated. The fundamental mathematical questions of convergence and uniqueness of the sum of these, not absolutely convergent, series are considered. It is shown that some of the simplest direct sum methods converge and some do not converge. In particular, the very common method of expressing Madelung’s constant by a series obtained from expanding spheres does not converge. The concept of analytic continuation of a complex function to provide a basis for an unambiguous mathematical definition of Madelung’s constant is introduced. By these means, the simple intuitive direct sum methods and the powerful integral transformation methods, which are based on theta function identities and the Mellin transform, are brought together. A brief analysis of a hexagonal lattice is also given.
89 citations
TL;DR: In this paper, the spectral and polarization properties of ion cyclotron waves (hereafter ICW's) generated in the magnetosphere by 10-100 keV protons are described with reference to ATS-6, GEOS and ground-based wave data and interpreted using cold plasma propagation theory.
Abstract: Ion cyclotron waves (hereafter ICW's) generated in the magnetosphere by the ion cyclotron instability of 10–100 keV protons are now known to be the origin of short-period (0.1–5 Hz) electromagnetic field oscillations observed by synchronous spacecraft and on the earth's surface. Observations of the various wave characteristics, including spectral and polarization properties that lead to the identification of generation and propagation mechanisms and regions in the magnetosphere are described with reference to ATS-6, GEOS and ground-based wave data and interpreted using cold plasma propagation theory. The presence of heavy ions (O+, He+) dramatically modifies ICW magnetospheric propagation characteristics giving rise to spectral slots and polarization reversals. These properties may be used in plasma diagnostics. Finally satellite-ground correlations and techniques for determining the magnetospheric source position of ICW's not seen at synchronous orbit but observed on the ground as structured Pc1 pulsations are considered.
86 citations
DOI•
01 Oct 1985TL;DR: In this paper, an alternative formulation for an optimum beamformer with a robustness capability against directional errors is presented, where the width of the main beam can be specified and a compromise can be reached between a reasonable signal acceptance angle and the ability of the beamformer to reject directional interferences.
Abstract: In the paper, an alternative formulation for an optimum beamformer with a robustness capability against directional errors is presented. With this approach, the width of the main beam can be specified and a compromise can be reached between a reasonable signal acceptance angle and the ability of the beamformer to reject directional interferences. Furthermore, based on a partitioned processor interpretation, the new beam-former gives a clue to a way of reducing the complexity of a full processor.
83 citations
TL;DR: In the majority of patients secondary hyperparathyroidism was controlled after parathyroidectomy although in seven patients (11 per cent), who underwent subtotal par Kathyroidectomy, it relapsed after initial improvement.
Abstract: In order to establish whether parathyroidectomy altered the natural history of ectopic calcification in patients with renal failure we undertook a detailed analysis of 62 patients with hyperparathyroidism secondary to chronic renal failure who were submitted to parathyroidectomy. Biochemical data (61 patients) and radiological skeletal surveys (42 patients) were studied before and after parathyroidectomy. Transiliac bone biopsies were obtained at (or some time in the previous six months before) parathyroidectomy in 30 and in 36 patients after surgery. Paired bone biopsies were available from 17 of these patients. In the majority of patients secondary hyperparathyroidism was controlled after parathyroidectomy although in seven patients (11 per cent), who underwent subtotal parathyroidectomy, it relapsed after initial improvement. Non-visceral soft tissue calcification disappeared or decreased in 60 per cent of the patients after parathyroidectomy. However, despite marked improvement in subperiosteal erosions and histological osteitis fibrosa, with significant reductions in iPTH and Ca X P product after parathyroidectomy, small peripheral arterial calcification developed or progressed in 56 per cent of the patients. Histological osteomalacia after parathyroidectomy developed after operation in two patients. Both had positive aluminium stains for excess aluminium in their bone. Numbers of osteoclasts and the amount of marrow fibrosis declined in parallel following parathyroidectomy, but woven bone persisted for months or years.
TL;DR: In this article, an explicit characterization of the concept of persistency of excitation for time-invariant linear systems in the presence of possibly unbounded signals has been developed.
Abstract: This note develops an explicit characterization of the concept of persistency of excitation for time-invariant linear systems in the presence of possibly unbounded signals. This result can be used to establish exponential convergence for a range of adaptive control algorithms. A feature of our proof is a particular technique for dealing with the initial condition response.
TL;DR: Findings suggest another mechanism by which the lactating ewe may confer immunity to its suckled young via the lacteal lymph ducts to the mesenteric lymph nodes.
TL;DR: There is a pattern of coronary prevention behavior spanning multiple risk factors that is associated with a reduction in ischemic heart disease in Australia, and significantly and consistently lower risk levels of blood pressure, triglyceride, cigarette smoking, body mass and exercise were found among higher status occupation groups.
Abstract: Mortality rates from ischemic heart disease in Australia declined by about 25% over the period 1969-1978. The greatest declines were experienced by the professional occupations, while lower socioeconomic groups had higher mortality rates at the beginning of the period and experienced smaller declines. From a national survey in 1980, significantly and consistently lower risk levels of blood pressure, triglyceride, cigarette smoking, body mass and exercise were found among higher status occupation groups. This suggests that there is a pattern of coronary prevention behavior spanning multiple risk factors that is associated with a reduction in ischemic heart disease.
TL;DR: Self-referent identity labels are frequently argued to be a central component of the self and to be important in the planning of conduct as mentioned in this paper, however, despite the attractiveness of this argument, relatively little is known about self-referential identity labels.
Abstract: Self-referent identity labels are frequently argued to be a central component of the self and to be important in the planning of conduct. Despite the attractiveness of this argument, relatively lit...
TL;DR: The data suggest that an influx of calcium into synaptosomes initially activates protein phosphorylation, but as the levels of intrasynaptosomal calcium rise protein dephosphorylation predominates.
Abstract: The effect of calcium on protein phosphorylation was investigated using intact synaptosomes isolated from rat cerebral cortex and prelabelled with 32Pi. For nondepolarised synaptosomes a group of calcium-sensitive phosphoproteins were maximally labelled in the presence of 0.1 mM calcium. The phosphorylation of these proteins was slightly decreased in the presence of strontium and absent in the presence of barium, consistent with the decreased ability of these cations to activate calcium-stimulated protein kinases. Addition of calcium alone to synaptosomes prelabelled in its absence increased phosphorylation of a number of proteins. On depolarisation in the presence of calcium certain of the calcium-sensitive phosphoproteins were further increased in labelling above nondepolarised levels. These increases were maximal and most sustained after prelabelling at 0.1 mM calcium. On prolonged depolarisation at this calcium concentration a slow decrease in labelling was observed for most phosphoproteins, whereas a greater rate and extent of decrease occurred at higher calcium concentrations. At 2.5 mM calcium a rapid and then a subsequent slow dephosphorylation was observed, indicating two distinct phases of dephosphorylation. Of all the phosphoproteins normally stimulated by depolarisation, only phosphoprotein 59 did not exhibit the rapid phase of dephosphorylation at high calcium concentrations. Replacing calcium with strontium markedly decreased the extent of change observed on depolarisation whereas barium decreased phosphorylation changes even further. Taken together these data suggest that an influx of calcium into synaptosomes initially activates protein phosphorylation, but as the levels of intrasynaptosomal calcium rise protein dephosphorylation predominates. Other phosphoproteins were dephosphorylated immediately on depolarisation in the presence of calcium. The fine control of protein phosphorylation levels exerted by calcium supports the idea that the synaptosomal phosphoproteins could play a role in modulating events such as neurotransmitter release in the nerve terminal.
26 Apr 1985
TL;DR: The transient and the steady state behaviour of the weight covariance matrix is analysed and the exact expressions for the misadjustment are derived when the required gradient is estimated using perturbation sequences.
Abstract: Adaptive antenna array processing employing a constrained least mean square (LMS) algorithm requires an unbiased estimate of the gradient of the output power with respect to the array weights. There are a number of schemes for obtaining an unbiased estimate of this gradient. Though in each case the estimated gradient is unbiased, the covariance of the estimated gradient with each method is different and thus the transient and the steady state behavior of the constrained algorithm is different in each case. The transient and the steady state behavior of the weight covariancc matrix is analyzed, exact expressions for the misadjustment are derived, and a comparison of the performance of the algorithm is presented when the required gradient is estimated by different schemes. The schemes considered include gradient estimation when all the array signals are accessible as well as gradient estimation using perturbation sequences for eases when the array signals are inaccessible. The necessary and the sufficient condition for the diagonlization of the weight covarience matrix is also derived.
TL;DR: A test algorithm is presented which contains a near-optimal WRITE sequence and is an improvement over existing algorithms and is well suited for built-in testing applications.
Abstract: In this correspondence we consider the problem of test pattern generation for random-access memory to detect pattern-sensitive faults. A test algorithm is presented which contains a near-optimal WRITE sequence and is an improvement over existing algorithms. The algorithm is well suited for built-in testing applications.
TL;DR: In this article, the results of a series of three-point bend test on pre-cracked concrete mortar and concrete beams were reported. But the results were limited to three size dependent effects, i.e., precracked, aggregate and specimen sizes.
TL;DR: In this paper, the evolution of coal nitrogen during devolatilization and the formation of NOx during combustion were studied for two Australian coals in crucible, thermobalance, and rapid heating (drop-tube furnace) experiments.
TL;DR: In this article, a fly ash cloud in p.f. furnaces has been found to have an order of magnitude higher complex refractive index than those of pure silica and alumina mixtures, the major constituents of the fly ash particles.
01 Jan 1985
TL;DR: This new algorithm deals correctly and automatically with the kind of cyclic (i.e. self-referencing) structures which arise in a combinator graph reduction machine by extending the standard reference count algorithm.
Abstract: This new algorithm deals correctly and automatically with the kind of cyclic (i.e. self-referencing) structures which arise in a combinator graph reduction machine. By extending the standard reference count algorithm, cycles can be handled safely at little extra cost. Cyclic reference counting uses one extra bit per pointer and per object and one extra reference count per object. Extra computation amounts to inspection of the objects in a cyclic structure from time to time before the structure becomes free. In the absence of cycles, no computation overhead is incurred. When executing some typical recursive programs, the number of objects inspected is approximately equal to the number of new objects used during execution.
TL;DR: The Piers-Harris Self Concept Scale was administered to 100 children (50 boys and 50 girls) in each of the age groups between 8 to 15 years inclusive (N = 800 children) as discussed by the authors.
Abstract: The Piers-Harris Self Concept Scale was administered to 100 children (50 boys and 50 girls) in each of the age groups between 8 to 15 years inclusive (N = 800 children). Data were analysed by principal components and iterative factor analysis. The results suggested that of the two analytic procedures the iterative procedure presented a comparatively clearer factor structure. It was concluded that the factors that seem to hold the most promise as diagnostic tools for clinical and counselling settings are: behaviour; intellectual and school status; physical appearance and attributes; anxiety; and, popularity.
TL;DR: It is postulated that the phenomenon of postpartum blues is a reaction to the euphoria of delivery which in turn is a response to endorphin release during labour, which may have a role in promoting maternal‐infant attachment at the expense of maternal depression some weeks later.
Abstract: Summary: Nineteen women were studied before, during and after labour by assessment of their mood using a variety of psychological tests and by measurement of their plasma concentrations of beta-endorphin and Cortisol. Beta-endorphin and Cortisol concentrations rose markedly during labour and were influenced by the type of analgesia used. A deterioration in cognitive performance between days 2 and 4 postpartum correlated positively with the fall in beta-endorphin concentrations from those in labour to those on the fourth day postpartum. The women were more anxious and depressed at 38 weeks' gestation than on days 1–4 postpartum and the elevation of mood on day 2 postpartum correlated with a measure of depression 8 weeks later. It is postulated that the phenomenon of postpartum blues is a reaction to the euphoria of delivery which in turn is a response to endorphin release during labour. Whilst these changes may have a role in promoting maternal-infant attachment it is at the expense of maternal depression some weeks later.
TL;DR: CAPD, as a form of treatment for end-stage renal disease, satisfactorily controls the osteodystrophy associated with renal failure in the majority of patients, and a high incidence of non-visceral metastatic calcification is noted.
Abstract: The biochemical data and drug histories related to bone disease were extracted from the case records of 47 patients who had been treated by continuous ambulatory peritoneal dialysis (CAPD) for more than two years. These data were reviewed in conjunction with the skeletal surveys done over the same period in all patients, with particular reference to secondary hyperparathyroidism, osteomalacia and non-visceral metastatic calcification. Paired bone biopsies were available in 20 of these patients and the histology was quantitated. In the majority of our patients secondary hyperparathyroidism was controlled or improved on CAPD. Osteomalacia also improved in two of the three patients in whom it was initially present and did not develop in any patient whilst on CAPD. We did, however, note a high incidence of non-visceral metastatic calcification. Small vessel calcification developed in 19.6 per cent of patients, large vessel calcification developed in 23.9 per cent and soft tissue calcification developed in 21.7 per cent of patients. We conclude that CAPD, as a form of treatment for end-stage renal disease, satisfactorily controls the osteodystrophy associated with renal failure in the majority of patients. The significance of the high incidence of non-visceral metastatic calcification remains to be established.
TL;DR: In this paper, it was shown that the adsorption mechanism involves migration of the Hg(II) species into the internal structure of the Mn(IV) oxide, where they either undergo ligand exchange with surface hydroxyl groups or are transformed into a solid hydroxy phase.
TL;DR: A number of specific results are presented aimed at gaining a unified description of certain aspects of modern estimation and control theory and isolating those features of particular algorithms which might give enhanced robustness properties especially when implemented digitally.
TL;DR: A chordal graph is a graph in which every cycle of length at least 4 has a chord as discussed by the authors, where every cycle has at least four vertices and every node has at most one chord.
Abstract: A chordal graph is a graph in which every cycle of length at least 4 has a chord. If G is a random n -vertex labelled chordal graph, the size of the larget clique in about n /2 and deletion of this clique almost surely leaves only isolated vertices. This gives the asymptotic number of chordal graphs and information about a variety of things such as the size of the largest clique and connectivity.
TL;DR: It seems that most of the cells extracted from chronically-inflamed tissue were producing lymphokines which may indicate stimulation in vivo prior to cell extraction, and there appeared to be no relationship between IL-2 production and BRA and the severity of the disease as assessed by loss of attachment.
TL;DR: It is shown that for narrowband applications, the number of linear constraints needed for an adaptive array to achieve a fixed look direction response can be reduced from two to one.
Abstract: It is shown that for narrowband applications, the number of linear constraints needed for an adaptive array to achieve a fixed look direction response can be reduced from two to one. The result is useful since it can be exploited to reduce the computational complexity required to determine the optimal weight vector.