Stability and convergence analysis of transform-domain LMS adaptive filters with second-order autoregressive process

In this paper, the stability and convergence properties of the class of transform-domain least mean square (LMS) adaptive filters with second-order autoregressive (AR) process are investigated. It is well known that this class of adaptive filters improve convergence property of the standard LMS adaptive filters by applying the fixed data-independent orthogonal transforms and power normalization. However, the convergence performance of this class of adaptive filters can be quite different for various input processes, and it has not been fully explored. In this paper, we first discuss the mean-square stability and steady-state performance of this class of adaptive filters. We then analyze the effects of the transforms and power normalization performed in the various adaptive filters for both first-order and second-order AR processes. We derive the input asymptotic eigenvalue distributions and make comparisons on their convergence performance. Finally, computer simulations on AR process as well as moving-average (MA) process and autoregressive-moving-average (ARMA) process are demonstrated for the support of the analytical results.

Critical analysis of action research-based inservice teacher education : four case histories

Changing the nature of institutionalised education is the central theme of the thesis. The potential for radical changes to classroom teaching and to inservice teacher education is considered through four curriculum and teaching reform projects structured by action -research. The problems explored through the thesis are at the levels of teaching, institutional and research practices. It is argued that the professional activity of teachers, administrators, consultants, teacher educators and researchers can be understood to be tightly bound and determined by rules for acceptable professional ways of acting which are often unquestioned and unexamined by educators themselves. It is further argued that institutionalised education is dominated by ways of thinking and acting that are inherently individualistic. The thesis analyses the ideological character of this 'individualistic1 structuring of educational practice, identifying belief systems that hold the lived reality of educators and students in place. The thesis endeavours to show that the bureaucratic character of institutionalised education primarily serves and maintains the interests of dominant groups. The thesis examines the possibilities for radical reform in classroom teaching, the support teachers need when embarking on curriculum and teaching change processes, and the possible outcomes of such reform. The thesis also examines the interaction between the institutional practices of schools, universities and regional offices in the Ministry of Education in Victoria, Australia on these reform processes in classrooms. Finally, the thesis examines the potential of action research as a research and educative process in the professional development of educators who are both critically aware of the ideological nature of institutionalised education and committed to collective social action. From the analyses of the four action research projects the thesis concludes that action research has the potential to transform institutionalised education when its own practice is firstly, developed as a liberating pedagogy and not as research projects structured by individualistic and paternalistic interests; secondly, is driven by a commitment to the political struggle for equity and social justice; and thirdly, is itself an expression of communitarian work. The thesis concludes that the transformative processes associated with action research under these conditions hold the promise of democratising the 'individualistic' character of institutional education.

Adolescent girls in physical education and sport : an analysis of influences on participation

This study investigates the influences on participation in physical activity of thirty adolescent girls from a metropolitan secondary school in Victoria. It seeks to understand how they perceived, experienced and explained their involvement or non involvement in both competitive and non competitive physical activity during four years of their secondary schooling. Participants experienced physical education as both a single sex group in Years 7 and 9 and a coeducational group in Years 8 and 10. They were exposed to a predominantly competitive curriculum in Years 7 to 9 and a less structured, more social, recreational program in Year 10. These experiences enabled them to compare the differences between class structures and activity programs and identify the significant issues which impacted on their participation. Large Australian population studies have revealed that fewer girls participated in sport and regular physical activity than boys. An important consequence is that girls miss out on the health benefits associated with participating in physical activity. Other research has found adolescence is the time that girls drop out of competitive sport. However, an important issue is whether girls who drop out of competitive sport cease to be involved in any physical activity. There are some studies which have reported good participation rates by adolescent girls in non competitive, recreational forms of physical activity and the possibility exists that they may drop out of competitive and into non competitive physical activity. This study primarily utilises a qualitative approach in contrast to previous studies which have largely relied upon the use of surveys and questionnaires. Whilst quantitative research has provided useful information about the bigger picture, there are limitations caused by reliance on the researchers' own interpretations of the data. Additionally there is no opportunity for any clarification and explanation of findings and trends by the respondents themselves. The current study utilized qualitative individual and collective interviews in three stages. Questions were asked in the broad areas of coeducation and single sex classes, preferences for competitive or recreational activity and body image issues. Some quantitative information focusing on nature and extent of current activity patterns was also gathered in the first stage. Thirty Year 10 girls participated in individual first interviews. Nine selected girls then took part in the second (individual) and third (collective) interview stages. Results revealed three groups based on the nature of physical activity involvement: [1] competitive activity group, [2] social activity group and [3] transition group. The transition group represented those who were in the process of withdrawing from competitive sport to take up more non competitive, recreational activity. The most significant difference between groups was skill level. On the whole those entering adolescence with the highest skill levels, such as those in the competitive group, were the most confident and relished competing against others. The social group was low in skill and confidence and had predominantly negative experiences in physical education and sport because their deficiencies were plainly visible to all. Similarly, a lack of skill improvement relative to those of 'better performers' affected the interest and confidence levels of those in the transition group. Boys' domination in coeducational classes through verbal and physical intimidation of the less competent and confident girls and exclusion of very competent girls was a major issue. Social and transition group members demonstrated compliance with boys' power by hanging back and sitting out of competitive activities. Conversely, the competitive group resisted boy's attempts to dominate but had to work hard to demonstrate their athletic capabilities in order to do so. Body image issues such as the skimpy physical education and sport uniform along with body revealing activities such as swimming and gymnastics, heightened feelings of self-consciousness and embarrassment for most girls. When strategies were adopted by social and transition group members to avoid any body exposure or physical humiliation, participation levels were subsequently affected. However, where girls felt confident about their physical abilities and body image, they were able to ignore their unflattering uniforms and thus participation was unaffected. Specific teaching practices such as giving more attention to boys, for example by segregating the sexes in mixed classes to focus attention on boys, reinforced stereotypical notions of gender and contributed to the inequities for girls in physical education. The competitive group were frustrated with having to prove themselves as capable as boys in order to receive greater teacher attention. The transition group rejected teacher's attempts to coerce them into participating in the inter school sports program. The social group believed that teachers viewed and treated them less favourably than others because of their limited skills. Girls were not passive in the face of these obstacles. Rather than give up physical activity they disengaged from competitive sport and took up other forms of activity which they had the confidence to perform. These activity choices also reflected their expanding social interests such as spending time with male and female friends outside school and increased demands on their time by study and part time work commitments. This study not only highlighted the diversity and complexity of attitudes and behaviours of girls towards physical activity but also demonstrated that they display agency in making conscious, sensible decisions about their physical activity choices. Plain Language Summary of Thesis Adolescent girls in physical education and sport; An analysis of influences on participation by Julia Whitty Submitted for the degree of Master of Applied Science Deakin University Supervisor: Dr Judy Ann Jones This study investigates the influences on participation in physical activity of thirty adolescent girls from a metropolitan secondary school in Victoria in order to understand how girls' perceived, experienced and explained their involvement or non involvement in both competitive and non competitive physical activity. Qualitative individual and collective interviews were conducted. Questions focussed on attitudes about coeducation and single sex classes, preferences for competitive or recreational activity and feelings about body image. Some quantitative information about the nature and extent of current activity patterns was also gathered in the first stage. Thirty Year 10 girls participated in individual first interviews. Nine selected girls then took part in the second (individual) and third (collective) interview stages. Results revealed three clearly different groups based on the nature of physical activity involvement (1) Competitive, (2) Social and (3) Transition (those in the process of withdrawing from competitive sport to take up more non competitive, recreational activity). The major difference between groups was skill level. Those entering adolescence with the highest skill levels were more competent and confident in the coeducational and competitive sport setting. Other significant issues included boys' domination, body image and teaching behaviours and practices.

Experimental and numerical analysis of the deformed process of cracks/cavities

In this paper, the three-point bending tests of beams with a small single-edge crack are conducted to demonstrate the reliability and accuracy of the laser diffraction technique in detecting its deformation and evolution. As a comparison, the quasi-static analysis of the beam subjected to 3-point bending is further proceeded using the finite element method and the related results have been in good agreement with those from the tests.

Functional analysis of the leading malaria vaccine candidate AMA-1 reveals an essential role for the cytoplasmic domain in the invasion process

A key process in the lifecycle of the malaria parasite Plasmodium falciparum is the fast invasion of human erythrocytes. Entry into the host cell requires the apical membrane antigen 1 (AMA-1), a type I transmembrane protein located in the micronemes of the merozoite. Although AMA-1 is evolving into the leading blood-stage malaria vaccine candidate, its precise role in invasion is still unclear. We investigate AMA-1 function using live video microscopy in the absence and presence of an AMA-1 inhibitory peptide. This data reveals a crucial function of AMA-1 during the primary contact period upstream of the entry process at around the time of moving junction formation. We generate a Plasmodium falciparum cell line that expresses a functional GFP-tagged AMA-1. This allows the visualization of the dynamics of AMA-1 in live parasites. We functionally validate the ectopically expressed AMA-1 by establishing a complementation assay based on strain-specific inhibition. This method provides the basis for the functional analysis of essential genes that are refractory to any genetic manipulation. Using the complementation assay, we show that the cytoplasmic domain of AMA-1 is not required for correct trafficking and surface translocation but is essential for AMA-1 function. Although this function can be mimicked by the highly conserved cytoplasmic domains of P. vivax and P. berghei, the exchange with the heterologous domain of the microneme protein EBA-175 or the rhoptry protein Rh2b leads to a loss of function. We identify several residues in the cytoplasmic tail that are essential for AMA-1 function. We validate this data using additional transgenic parasite lines expressing AMA-1 mutants with TY1 epitopes. We show that the cytoplasmic domain of AMA-1 is phosphorylated. Mutational analysis suggests an important role for the phosphorylation in the invasion process, which might translate into novel therapeutic strategies.

An analysis of the role of teachers’ aides in a state secondary school: perceptions of teaching staff and teachers’ aides

In Victoria, Australia, one of the major roles of the teachers’ aide (TA) is to assist students with disabilities to access their education. Researchers have identified the inconsistencies in defining the roles of the TA, in a variety of settings, by TAs, teachers, parents, and other research participants. Four main themes that have been frequently reported in educational research related to the role of TAs formed the basis for this study: (a) inclusion in the school community, (b) curriculum, (c) classroom management, and (d) student support. Drawing on the results of a questionnaire administered to teachers and TAs at a government nonselective secondary school in Victoria, Australia, data were collected to explore the differing perspectives on the role of the TAs by the teaching staff and the TAs. In all, 65 individuals participated in this study. The participants formed 3 groups: TAs (n = 10), teachers (n = 49), and T/TAs (n = 6; participants in this group had worked as both a teacher and TA). The results of the study showed a diversity of views across the 4 themes. In 3 of the 4 themes that included inclusion, classroom management, and student support, the 3 groups agreed on the role of the TA. In the remaining theme, curriculum, opinions varied significantly. The results of the study reveal that a concerted effort to clarify the role of TAs would be beneficial to all stakeholders.

Numerical modeling and analysis for forming process of dual-phase 980 steel exposed to infrared local heating

A recent experiment confirmed that the infrared (IR) local heating method drastically reduces springback of dual-phase (DP) 980 sheets. In the experiment, only the plastic deformation zone of the sheets was locally heated using condensed IR heating. The heated sheets were then deformed by V-bending or 2D-draw bending. Although the experimental observation proved the merit of using the IR local heating to reduce springback, numerical modeling has not been reported. Numerical modeling has been required to predict springback and improve the understanding of the forming process. This paper presents a numerical modeling for V-bending and 2D-draw bending of DP 980 sheets exposed to the IR local heating with the finite element method (FEM). For describing the thermo-mechanical behavior of the DP 980 sheet, a flow stress model which includes a function of temperature and effective plastic strain was newly implemented into Euler-backward stress integration method. The numerical analysis shows that the IR local heating reduces the level of stress in the deformation zone, although it heats only the limited areas, and then it reduces the springback. The simulation also provides a support that the local heating method has an advantage of shape accuracy over the method to heat the material as a whole in V-bending. The simulated results of the springback in both V-bending and 2D-draw bending also show good predictions.

Systematic approach to the quantitative voltammetric analysis of the Fe III /Fe II component of the [α 2 -Fe(OH 2 )P 2 W 17 O 61 ] 7-/8- reduction process in buffered and unbuffered aqueous media

The one-electron reduction of [α2-FeIII(OH2)P2W17O61]7- at a glassy carbon electrode was investigated using cyclic and rotating-disk-electrode voltammetry in buffered and unbuffered aqueous solutions over the pH range 3.45−7.50 with an ionic strength of approximately 0.6 M maintained. The behavior is well-described by a square-scheme mechanism P + e- ↔ Q (E10/ = −0.275 V, k10/ = 0.008 cm s-1, and α1 = 1/2), PH+ + e- ↔ QH+ (E20/ = −0.036 V, k20/ = 0.014 cm s-1, and α2 = 1/2), PH+ ↔ P + H+ (KP = 3.02 × 10-6 M), and QH+ ↔ Q + H+ (KQ = 2.35 × 10-10 M), where P, Q, PH+, and QH+ correspond to [α2-FeIII(OH)P2W17O61]8-, [α2-FeII(OH)P2W17O61]9-, [α2-FeIII(OH2)P2W17O61]7-, and [α2-FeII(OH2)P2W17O61]8-, respectively; E10‘ and E20‘ are the formal potentials, k10‘ and k20‘ are the formal (standard) rate constants, and KP and KQ are the acid dissociation constants for the relevant reactions. The analysis for the buffered media is based on the approach of Laviron who demonstrated that a square scheme with fully reversible protonations, reversible or quasi reversible electron transfers with the assumption that α1 = α2, can be well-described by the behavior of a simple redox couple, ox + e- ↔ red, whose formal potential, Eapp0‘, and standard rate constant, kapp0‘, are straightforwardly derived functions of pH, as are the values of E10‘, k10‘, E20‘, k20‘, and KP (only three of the four thermodynamic parameters in a square scheme can be specified). It was assumed that αapp = 1/2, and the simulation program DigiSim was used to determine the values of Eapp0‘ and kapp0‘, which are required to describe the cyclic voltammograms obtained in buffered media in the pH range from 3.45 to 7.52 (buffer-related reactions which effect general acid−base catalysis are included in the simulations). DigiSim simulations of cyclic voltammograms obtained in unbuffered media yielded the values of E10‘ and k10‘; KQ was then directly computed from thermodynamic constraints. These simulations included additional reactions between the redox species and H2O. The value of the diffusion coefficient of the [α2-FeIII(OH2)P2W17O61]7-, 2.92 × 10-6 cm2 s-1, was determined using DigiSim simulations of voltammograms at a rotating disk electrode in buffered and unbuffered media at pH 3.45. The diffusion coefficients of all redox species were assumed to be identical. When the pH is greater than 6, instability of P (i.e., [α2-FeIII(OH)P2W17O61]8-) led to the loss of the reactant and precluded lengthy experimentation.

Theoretical analysis of the energy levels induced by oxygen vacancies and the doping process (Co, Cu and Zn) on SnO2 (110) surface models

Density functional calculation at B3LYP level was employed to study the surface oxygen vacancies and the doping process of Co, Cu and Zn on SnO2 (110) surface models. Large clusters, based on (SnO2)(15) models, were selected to simulate the oxidized (Sn15O30), half-reduced (Sn15O29) and the reduced (Sn15O28) surfaces. The doping process was considered on the reduced surfaces: Sn13Co2O28, Sn13Cu2O28 and Sn13Zn2O28. The results are analyzed and discussed based on a calculation of the energy levels along the bulk band gap region, determined by a projection of the monoelectron level structure on to the atomic basis set and by the density of states. This procedure enables one to distinguish the states coming from the bulk, the oxygen vacancies and the doping process, on passing from an oxidized to a reduced surface, missing bridge oxygen atoms generate electronic levels along the band gap region, associated with 5s/5p of four-/five-fold Sn and 2p of in-plane O centers located on the exposed surface, which is in agreement with previous theoretical and experimental investigations. The formation energy of one and two oxygen vacancies is 3.0 and 3.9 eV, respectively. (C) 2001 Elsevier B.V. B.V. All rights reserved.

Brazilian Students and Working Capital: An Analysis of Their Decisions When Using Virtual Market Business Games

This study aims to demonstrate that data from business games can be an important resource for improving efficiency and effectiveness of learning. The proposal presented here was developed from preliminary studies of data from Virtual Market games that pointed the possibility of identifying gaps in learning by analyzing the decisions of students. This proposal helps students to refine their learning processes and equips tutors with strategies for teaching and student assessment. The proposal also complements the group discussion and/or debriefing, which are widely used to enhance learning mediated by games. However, from a management perspective the model has the potential to be erroneous and miss opportunities, which cannot be detected because of the dependence on the characteristics of the individual, such as ability to communicate and work together. To illustrate the proposed technique, data sets from two business games were analyzed with the focus on managing working capital and it was found that students had difficulties managing this task. Similar trends were observed in all categories of students in the study-undergraduate, postgraduate and specialization. This discovery led us to the analysis of data for decisions made in the performance of the games, and it was determined that indicators could be developed that were capable of indentifying inconsistencies in the decisions. It was decided to apply some basic concepts of the finance management, such as management of the operational and non-operational expenditures, as well as production management concepts, such as the use of the production capacity. By analyzing the data from the Virtual Market games using the indicator concept, it was possible to detect the lack of domain knowledge of the students. Therefore, these indicators can be used to analyze the decisions of the players and guide them during the game, increasing their effectiveness and efficiency. As these indicators were developed from specific content, they can also be used to develop teaching materials to support learning. Viewed in this light, the proposal adds new possibilities for using business games in learning. In addition to the intrinsic learning that is achieved through playing the games, they also assist in driving the learning process. This study considers the applications and the methodology used.