Showing papers by "Queensland University of Technology published in 1995"

Survey and critique of techniques for extracting rules from trained artificial neural networks

Abstract: It is becoming increasingly apparent that, without some form of explanation capability, the full potential of trained artificial neural networks (ANNs) may not be realised. This survey gives an overview of techniques developed to redress this situation. Specifically, the survey focuses on mechanisms, procedures, and algorithms designed to insert knowledge into ANNs (knowledge initialisation), extract rules from trained ANNs (rule extraction), and utilise ANNs to refine existing rule bases (rule refinement). The survey also introduces a new taxonomy for classifying the various techniques, discusses their modus operandi, and delineates criteria for evaluating their efficacy.

Anatomical methods in cell death

Abstract: Publisher Summary This chapter describes methods for studying the morphology of cell death and the criteria used in identifying apoptosis and necrosis. Electron microscopy provides the most reliable method for recognizing the two processes; in many cases, however, they can be identified confidently using light microscopy alone. The recognition of apoptosis and necrosis is based primarily on the distinctive changes that take place within the affected cells. However, when these two processes occur in vivo, they also differ in their distribution and in the tissue reactions that are associated with them. These latter features may be of subsidiary use in identification. Thus, apoptosis involves scattered individual cells in a tissue, whereas necrosis involves groups of adjoining cells. Necrosis is accompanied by an acute inflammatory response with exudation of neutrophil leukocytes and monocytes; this event is characteristically absent in apoptosis. The light microscopic recognition of apoptosis depends on the detection of discrete well-preserved apoptotic bodies. Although convoluted budding cells are sometimes observed in smears, they are rarely seen in paraffin sections of immersion-fixed tissue.

Gene flow and larval duration in seven species of fish from the great barrier reef

Abstract: The Great Barrier Reef (GBR) is a continental archipelagic system of 5000 reefs and shoals stretching >2000 km along the east Australia coast. The interconnectivity of these reefs should determine the choice of biological management units, which for most biota will reflect the dispersal of their eggs and/or larvae. A comparative approach using population genetics was used to ask whether the along-shore dispersal of coral reef fishes is influenced by the duration of this mobile phase. Seven species of coral reef fish, selected from three families to provide a range of taxonomic diversity and pelagic larval durations, were tested for genetic homogeneity between two regions of the GBR separated by 1000 km. A spectrum of potential dispersal capabilities was analyzed from that of Acanthochromis polyacanthus, a damselfish with brood care that uniquely lacks pelagic larvae, to that of Ctenochaetus striatus, a surgeonfish with large, specialized larvae that spend several months in the plankton. A total of 19 enzyme systems and general proteins were examined from multiple populations in each region to provide a base of 32 loci for these comparisons. With one exception, species sampled from different coral reefs within regions showed statistically significant heterogeneities across multiple loci, indicative of chaotic genetic patchiness among the samples. The exception was an anemonefish, Amphiprion melanopus, that had to be collected from large areas on each reef because of its low densities. The homogeneity of allele frequencies at local scales for this species suggests that the genetic patchiness observed in others may be a within-reef phenomenon that was manifested at the reef scale by our pseudoreplicated sampling strategy. After pooling local variability, all but two species showed significant regional differ- ences. The exceptions were the pair (Ctenochaetus striatus, Pterocaesio chrysozona) with the longest larval durations. Acanthochromis polyacanthus showed increased variation at this larger scale, consistent with a major stock division between the two regions. The logarithm of genetic variation between northern and southern populations (measured by Weir and Cockerham's Fst)was correlated with mean larval duration by an inverse linear relationship that explained 85% of the variance in the global data set. Comparison with an outgroup (Amphiprion melanopus from the Chesterfield Reefs, 1000 km east in the Coral Sea) confirmed the genetic cohesion of mainland populations for the species with shortest larval duration and shows that our empirical relationship applies only within the context of the highly connected GBR. On this basis, calculations of gene flow (Nem, the number of effective migrants per generation) between geographic regions predict panmixis for species with larval durations exceeding 1 mo. Many common species have shorter dispersal times, from which classical "isolation-by-distance" models predict differentiation between northern and southern pop- ulations at genetic equilibrium. Given that modern populations on the GBR are <10000 yr old, however, there has not been sufficient time for such differences to evolve in situ and we consider alternative scenarios for the observed heterogeneities. Comparisons with invertebrate taxa sampled over the same spatial scales imply lower gene flows in fish despite longer pelagic durations. This suggests that fish larvae may use their greater mobility to retard, rather than enhance, dispersal due to hydrodynamic advection.

Evolution and Validation of a Personal Form of an Instrument for Assessing Science Laboratory Classroom Environments.

Abstract: The research reported in this article makes two distinctive contributions to the field of classroom environment research. First, because existing instruments are unsuitable for science laboratory classes, the Science Laboratory Environment Inventory (SLEI) was developed and validated. Second, a new Personal form of the SLEI (involving a student's perceptions of his or her own role within the class) was developed and validated in conjunction with the conventional Class form (involving a student's perceptions of the class as a whole), and its usefulness was investigated. The instrument was cross-nationally fieldtested with 5,447 students in 269 senior high school and university classes in six countries, and cross-validated with 1,594 senior high school students in 92 classes in Australia. Each SLEI scale exhibited satisfactory internal consistency reliability, discriminant validity, and factorial validity, and differentiated between the perceptions of students in different classes. A variety of applications with the new instrument furnished evidence about its usefulness and revealed that science laboratory classes are dominated by closed-ended activities; mean scores obtained on the Class form were consistently somewhat more favorable than on the corresponding Personal form; females generally held more favorable perceptions than males, but these differences were somewhat larger for the Personal form than the Class form; associations existed between attitudinal outcomes and laboratory environment dimensions; and the Class and Personal forms of the SLEI each accounted for unique variance in student outcomes which was independent of that accounted for by the other form.

The development of a clinical learning environment scale

Abstract: Within nursing, there is a strong demand for high-quality, cost-effective clinical education experiences that facilitate student learning in the clinical setting. The clinical learning environment (CLE) is the interactive network of forces within the clinical setting that influence the students' clinical learning outcomes. The identification of factors that characterize CLE could lead to strategies that foster the factors most predictive of desirable student learning outcomes and ameliorate those which may have a negative impact on student outcomes. The CLE scale is a 23-item instrument with five subscales: staff-student relationships, nurse manager commitment, patient relationships, interpersonal relationships, and student satisfaction. These factors have strong substantive face validity and construct validity, as determined by confirmatory factor analysis. Reliability coefficients range from high (0.85) to marginal (0.63). The CLE scale provides the educator with a valid and reliable instrument to evaluate affectively relevant factors in the CLE, direct resources to areas where improvement may be required, and nurture those areas functioning well. It will assist in the application of resources in a cost-effective, efficient, productive manner, and will ensure that the clinical learning experience offers the nursing student the best possible learning outcomes.

Decompilation of Binary Programs

Abstract: The structure of a decompiler is presented, along with a thorough description of the different modules that form part of a decompiler, and the type of analyses that are performed on the machine code to regenerate high-level language code. The phases of the decompiler have been grouped into three main modules: front-end, universal decompiling machine, and back-end. The front-end is a machine dependent module that performs the loading, parsing and semantic analysis of the input program, as well as generating an intermediate representation of the program. The universal decompiling machine is a machine and language independent module that performs data and control flow analysis of the program based on the intermediate representation, and the program''s control flow graph. The back-end is a language dependent module that deals with the details of the target high-level language.

JCPDS--International Centre for Diffraction Data round robin study of silver behenate. A possible low-angle X-ray diffraction calibration standard

Abstract: A task group of the JCPDS—International Center for Diffraction Data (ICDD) was established with the charge of investigating the use of silver behenate, CH 3 (CH 2 ) 20 COO·Ag, as a possible low-angle calibration standard for powder diffraction applications. Utilizing several data collection and analysis techniques, long-period spacing ( d 001 ) values with a range of 58.219–58.480 A were obtained. Using the same collected data and one data analysis refinement calculation method resulted in dm values with a range of 58.303–58.425 A. Data collected using a silicon internal standard and the same singular data analysis calculation method provided d 001 values with a range of 58.363–58.381 A.

The genome organization of banana bunchy top virus: analysis of six ssDNA components

Abstract: We have cloned, sequenced and analysed an additional five circular ssDNA components of banana bunchy top virus (BBTV) which we have called components 2, 3, 4, 5 and 6. These components were present in all BBTV infections tested. Four of these components (components 3, 4, 5 and 6) had one large open reading frame (ORF) in the virion sense located 3′ of a stem-loop structure. Each ORF had a potential TATA box and one or two potential polyadenylation signals associated with it and each polyadenylation signal had an associated GC-rich region containing the trinucleotide sequence TTG. A number of ORFs were identified in component 2 but none of these had appropriately located potential TATA boxes and polyadenylation signals associated with them. None of the ORF amino acid sequences nor the full DNA sequences of any of the components had significant sequence identity with any known protein or nucleic acid sequences. However, the ORF of component 4 encoded a 30 residue hydrophobic domain which may indicate that this ORF encoded a trans-membrane protein. Further, the ORFs of components 3 and 5 potentially encoded proteins of about 20 kDa, the size of the BBTV coat protein. There were two regions of sequence identity between the five components described here and the previously described component 1. Each component contained a conserved stem-loop structure and a nonanucleotide potential TATA box which was 5′ of the large virion-sense ORF in five of the components. The stem-loop structures were incorporated in a common region (CR-SL) of 69 nucleotides which was 62% identical between components. All six BBTV components also contained a major common region (CR-M) which was located 5′ of the CR-SL in each component, in the non-coding region and was 76% identical over 92 nucleotides. Each CR-M contained a near-complete 16 nucleotide direct repeat and a GC-box which was similar to the rightward promoter element found in wheat dwarf geminivirus. From these results, BBTV appears to belong to an undescribed plant virus group which could also include subterranean clover stunt virus, coconut foliar decay virus, faba bean necrotic yellows virus and milk vetch dwarf virus.

Measurement of Monochromatic Ocular Aberrations of Human Eyes as a Function of Accommodation by the Howland Aberroscope Technique

Abstract: Further development of the objective version of the Howland and Howland [(1976) Science, 193, 580-582; (1977) Journal of the Optical Society of America, 67, 1508-1518 aberroscope technique for measuring ocular aberrations is described. Compensation for refractive corrections and calibration is discussed. The technique was used to investigate the effect of accommodation upon the monochromatic aberrations of the right eyes of 15 subjects. Coma and coma-like aberrations were the dominant aberrations for most people at different accommodation levels, thus confirming previous findings. Variations in aberrations were considerable between subjects. About half the subjects showed the classical trend towards negative spherical aberration with accommodation. Changes in spherical aberration with accommodation in this study were less than that found in previous studies where all monochromatic aberration was considered to be spherical aberration.

Fourier Transform Raman Spectroscopy of Kaolinite, Dickite and Halloysite

Abstract: The vibrational modes of clay minerals are uniquely accessible to FT Raman spectroscopy, but this potentially powerful technique has found limited application to the study of clay mineral structure. Raman spectra in the 50 to 3800 cm-t region were obtained for a number of kandite clays. The kandite clay minerals are characterised by relatively intense bands centred at 142.7 cm -I for kaolinite, 143 cm -~ for halloysite and 131.2 cm-I for dickite with prominent shoulders at 129, 127, and 120 cm- 1 respectively. These vibrational modes are attributed to the O-A1-O and O-Si-O symmetric bends. Differences in the lattice modes for the kandite clay minerals in the 200 to t200 cm -I were obtained. Four OH bands were obtained for kaolinite 3621, 3652, 3668, and 3695 cm-1; three OH bands were found for a selection of dickites and halloysites. The San Juan Dickite and the Eureka Halloysite show further resolution of the low frequency 3620 cm -1 hydroxyl band. This splitting is attributed to variation in the position of the inner hydroxyls. Variation in band intensity and position was found to be sample dependent.

Science Laboratory Classroom Environments at Schools and Universities: A Cross‐National Study∗

Abstract: Because already existing classroom environment scales are unsuitable for science laboratory classes, a new instrument was developed and validated in a Class form (student's perceptions of the class as a whole) and a new Personal form (student's perceptions of his/her own role within the class). The instrument was cross‐nationally field tested with 5,447 students in 269 classes in six countries, and cross‐validated with 1,594 students in 92 classes in Australia. Each scale exhibited satisfactory internal consistency reliability, discriminant validity, and factorial validity, and differentiated between the perceptions of students in different classes. Use of the new instrument revealed that: science laboratory classes are dominated by closed‐ended activities; Class form means consistently were more favorable than Personal form means; associations existed between attitudinal outcomes and laboratory environment; and the Class and Personal form each accounted for unique variance in student attitudes.

Accurate static branch prediction by value range propagation

Abstract: The ability to predict at compile time the likelihood of a particular branch being taken provides valuable information for several optimizations, including global instruction scheduling, code layout, function inlining, interprocedural register allocation and many high level optimizations. Previous attempts at static branch prediction have either used simple heuristics, which can be quite inaccurate, or put the burden onto the programmer by using execution profiling data or source code hints.This paper presents a new approach to static branch prediction called value range propagation. This method tracks the weighted value ranges of variables through a program, much like constant propagation. These value ranges may be either numeric of symbolic in nature. Branch prediction is then performed by simply consulting the value range of the appropriate variable. Heuristics are used as a fallback for cases where the value range of the variable cannot be determined statically. In the process, value range propagationsubsumes both constant propagation and copy propagation.Experimental results indicate that this approach produces significantly more accurate predictions than the best existing heuristic techniques. The value range propagation method can be implemented over any “factored” dataflow representation with a static single assignment property (such as SSA form or a dependence flow graph where the variables have been renamed to achieve single assignment). Experimental results indicate that the technique maintains the linear runtime behavior of constant propagation experienced in practice.

Measurement of Anaerobic Work Capacities in Humans

Abstract: Anaerobic capacity is defined as the maximal amount of adenosine triphosphate resynthesised via anaerobic metabolism (by the whole organism) during a specific mode of short-duration maximal exercise. This review focuses on laboratory measures which attempt to quantify anaerobic capacity; it examines the evidence supporting or challenging the validity of these measures and provides research foci for future investigations. Discussion focuses on anaerobic capacity measured during running and cycling, since almost all data reviewed were collected using these exercise modes.

Stages in learning new technology: naive adult email users

Abstract: How do adult students learn to use new technologies? Teachers' and learners' understanding of stages these students may pass through makes the learning process less traumatic. The research identifies six stages adult learners pass through as they become confident in their use of electronic mail. In the beginning stages there is tension as the technological processes dominate and intrude on the email interactions. Eventually, by Stage Six, the technology becomes invisible and the user is able to use email creatively with comfortable confidence. Understanding the stages of learning to use the technology empowers the learner through the knowledge that feelings of tension and frustration will be overcome.

Restraints to reform: The congruence of teacher and student actions in a chemistry classroom

Abstract: An interpretive methodology was employed to examine interrelations between teacher and student actions in a context of teaching and learning in an urban high school in Australia, a teacher of 20 years' experience, and a Grade 11 chemistry class Data sources included teacher and student interviews, direct observation and videotapes of 4 weeks of lessons, and responses to a classroom environment survey Three narratives were constructed for a typical lesson, the perspectives of the teacher, and the perspectives of a composite student These narratives were used to describe what happened and communicate what we learned from the study Initially, the teacher and students had difficulty describing their beliefs; however, as the study progressed they used language to describe their practices and construct mental models that fit with their practices and beliefs about learning Teacher and student goals, beliefs about teacher and learner roles, and constructions of the context were coherent to such an extent that there was little impetus for change These findings are discussed in terms of the difficulties of initiating and sustaining reform when the teacher and students are satisfied with what is happening and other sociocultural factors tend to support the status quo

Elderly drivers and simulated visual impairment.

Abstract: BACKGROUND. The effect of simulated visual impairment on the driving performance of elderly subjects and the relation between changes in driving performance and vision were investigated. METHODS. Vision was impaired by goggles simulating the effects of cataracts, binocular visual field restriction, and monocularity. Driving was assessed on a road circuit free of other vehicles. Visual performance was measured using the Humphrey Field Analyser (HFA), the Useful Field of View (UFOV), and the Pelli-Robson chart. RESULTS. The simulated visual impairment significantly decreased driving performance, even though all drivers satisfied the legal visual requirements for driving. Significant correlations between driving performance and the UFOV and Pelli-Robson chart were found.

Pain: the views of elderly people living in long-term residential care settings.

Abstract: While an individual's beliefs and attitudes have long been considered important factors in how people respond to pain, few studies have attempted to provide in-depth descriptions of the nature of such pain beliefs and attitudes The aim of this research was to investigate the views of pain and pain management practices held by elderly people living in long-term residential care settings Ten 60–90 minute focus group interviews, each involving around five elderly people, were conducted in four large, long-term residential care settings in Brisbane, Australia Categories of beliefs and attitudes regarding pain were identified following analysis of the verbatim transcripts of these interviews Findings suggest that many elderly people living in long-term residential care settings may have become resigned to pain, that they are ambivalent about the benefit of any action for their pain and that they may be reluctant to express their pain Implications of these beliefs and attitudes are discussed

Mentoring Beginning Teachers: a qualitative analysis of process and outcomes

Abstract: Sixteen beginning teachers commencing their first year of teaching in Queensland Catholic schools, together with nine experienced teachers appointed as their mentors, provided detailed written reflections on their experiences during the beginners’ first year of teaching. Using their responses as data, the nature and value of the buddy mentoring relationship are analysed in relation to the needs, concerns and professional development of beginning teachers as they progress through the year. Patterns and themes emerging from the data are described qualitatively and illustrated by direct quotations from participants’ responses. Conclusions are drawn regarding the roles and functions of mentors which are most helpful at various stages, the benefits and limitations of buddy mentoring in relation to these functions and issues involved in the development of the mentoring relationship over the course of the first teaching year.