Video lectures for cross-cultural use: a three phase model

This paper will discuss the contributing factors of; increasing numbers of international students, and the advancement of learning technologies; that lead to the development of an exploratory research study into the creation of a three phase online lecture model. Aspects such as the differences between the major cultural groups currently enrolled in Australian Universities, indicates the variations that can be expected in student learning styles. This research study aims at determining the educational value of the inclusion of online lectures for a diverse and distributed cross-cultural audience.

Robust nonlinear controller design for three-phase grid-connected photovoltaic systems under structured uncertainties

This paper presents a robust nonlinear controller design for a three-phase grid-connected photovoltaic (PV) system to control the current injected into the grid and the dc-link voltage for extracting maximum power from PV units. The controller is designed based on the partial feedback linearization approach, and the robustness of the proposed control scheme is ensured by considering structured uncertainties within the PV system model. An approach for modeling the uncertainties through the satisfaction of matching conditions is provided. The superiority of the proposed robust controller is demonstrated on a test system through simulation results under different system contingencies along with changes in atmospheric conditions. From the simulation results, it is evident that the robust controller provides excellent performance under various operating conditions. © 2014 IEEE.

Nonlinear backstepping controller design for sharing active and reactive power in three-phase grid-connected photovoltaic systems

In this paper, a nonlinear backstepping controller is designed for three-phase grid-connected solar photovoltaic (PV) systems to share active and reactive power. A cascaded control structure is considered for the purpose of sharing appropriate amount of power. In this cascaded control structure, the dc-link voltage controller is designed for balancing the power flow within the system and the current controller is designed to shape the grid current into a pure sinusoidal waveform. In order to balance the power flow, it is always essential to maintain a constant voltage across the dc-link capacitor for which an incremental conductance (IC) method is used in this paper. This approach also ensures the operation of solar PV arrays at the maximum power point (MPP) under rapidly changing atmospheric conditions. The proposed current controller is designed to guarantee the current injection into the grid in such a way that the system operates at a power factor other than unity which is essential for sharing active and reactive power. The performance of the proposed backstepping approach is verified on a three-phase grid-connected PV system under different atmospheric conditions. Simulation results show the effectiveness of the proposed control scheme in terms of achieving desired control objectives.

Characteristics evaluation of a μ-Synthesis H∞ controller for a grid-connected three-phase photovoltaic system

This paper presents a μ-Synthesis H∞ Controller for regulating the switching signal of the inverter connected with a three-phase photovoltaic (PV) system. To facilitate the control design, the system is represented in terms of state space realization with uncertainties. The control design involves selecting proper weighting functions and performing synthesis. The controller order is reduced by Henkel-norm method. Simulations are carried out to evaluate the characteristics of the controller under parametric uncertainties. It is found out that the proposed controller is inherently stable, possesses significantly small tracking error, and preserves nominal performance, robust stability and robust performance for the grid-connected three-phase PV system.

Analysis of residues of prometryne and acetochlor in soil-water system by solid-phase extraction and gas chromatography/mass spectrometry

A highly sensitive and simple analytical method was developed for analyzing the binary mixed pesticides of prometryne and acetochlor in soil–water system by gas chromatography/mass spectrometry (GC/MS). The sample solution was first purified by C18 solid-phase extraction column, which was leached by acetone. The leachate was enriched to 1.0 mL by pressure blowing concentrator and then analyzed by GC/MS. The linear calibration curves were showed in the range of 1–15 μg/mL with a correlation coefficient of 0.9991. The average recoveries (n = 5) were between 95.3 and 115.7%, with relative standard deviations ranged from 1.71 and 7.95%. The limits of detection of Prometryne/Acetochlor were up to 0.06 and 0.17 μg/mL, respectively. This method provides a reliable approach to examine and evaluate the residues of prometryne and acetochlor in the soil–water system.

Voltage stability analysis with optimum size and location based synchronous machine DG

Power loss of a distribution system can be reduced significantly by using optimum size and location of distributed generation (DG). Proper allocation of DG with appropriate size maximizes overall system efficiency. Moreover it improves the reliability and voltage profile of the distribution system. In this paper, IEEE 123 node test feeder has been considered to determine the optimum size and location of a synchronous machine based DG for loss reduction of the system. This paper also investigates the steady-state and dynamic voltage profile of that three phase unbalance distribution network in presence of DG with optimum size. This analysis shows that optimum size of DG at proper location minimizes the power loss as well as improves the dynamic voltage profile of the distribution system.

An analysis of hatchling resting metabolism: in search of ecological correlates that explain deviations from allometric relations

From data in the literature, an allometric equation is compiled for hatchling resting metabolic rate and an attempt is made to explain residual variation in terms of hatchling type, yolk and water content, embryonic and postnatal growth rate, and environmental circumstances (latitudinal distribution). The body mass exponent for resting metabolism in hatchlings was 0.86 and, thus, substantially different from the values compiled for adult birds (0.67-0.75). Relatively high hatchling metabolic rates were found for birds exhibiting high embryonic and postnatal growth rates, as well as for those species that hatched at high latitudes. A functional explanation is postulated for the correlations between hatchling metabolism and these three variables.

A comparative study of different power system stabilizers for dynamic stability analysis

Power system stabilizers (PSSs) are extensively used to ensure the dynamic stability of power systems through the modulation of excitation signals supplied to synchronous generators. This paper presents a comparative study of two different PSSs: STAB1 and IEEEST. The stabilizers are designed for the linearized model of a single machine infinite bus (SMIB) system with different loads. Both time-and frequency-domain simulations are carried out to investigate the performance of these stabilizers. For all PSSs, the time-domain simulations are performed by applying a three-phase short-circuit fault at the terminal of the synchronous generator. These simulation results are compared against the open-loop characteristics of the SMIB system where no PSS is implemented. Simulation results demonstrate that the speed-fed PSS provides more damping as compared to frequency- and power-fed stabilizers.

Marketing readiness of websites and organisational performance in Australia and New Zealand: a discussion of pre-test findings

The Web played a role in the burst of economic activity that occurred in the late 1990s that saw company values dramatically rise and fall, business and government processes reshaped, traditional marketing media challenged, and much written concerning the benefits to customers from the adoption of what was initially termed e-commerce. Initial empirical studies of Australian and New Zealand business and government use of the Web found that while the Web was used for marketing communication, it was not as favoured as trade press reports suggested as a marketing transaction channel, nor for relationship management. This paper, which reports the findings of a pre-test of the self-administered online questionnaire stage of a three-phase study, suggests that little has changed in organisational use of the Web in Australia and New Zealand since the late 1990s, even among high network traffic organisations. The pre-test findings reported do not present a clear picture concerning the influence of strategic use of traditional and online marketing mix elements on organisational performance. Analysis employing a Marketing Readiness of Website Indicator (MRWI) content analysis tool is shown not to predict organisational performance as hypothesised.

Towards ending the silence: working women caring for children with chronic illness

This paper presents stories from women who work and care for a child with a significant chronic illness or disability. The purpose of this paper is to move towards ending the silence on their lives. A three-phase emergent research design responds to the question: What is life like for a full-time worker who is concurrently the primary carer of a chronically ill child? This paper considers the theory of Silencing the Self (Jack, 1991) in relation to the emergent themes of “Otherness” and “Doing it All.” As in Jack’s study, these women also engaged in silencing of the self. However, unlike the respondents in Jack’s study, these women did not demonstrate feelings of worthlessness and hopelessness for the future, nor were they alone in contributing to their silence. Indeed, many experienced silencing behaviors from others around them, and many rallied against the silence, not accepting that their burden should continue. Consideration of Jack’s theory is made to point out the distinctions between the women in this study and Jack’s study, and analytical commentary is provided to demonstrate the relevance of this analysis in light of the current debates surrounding the Work–Home Conflict and the rising levels of informal care provided by women in our communities.

Phylogenetic relationships among nine scallop species (Bivalvia : Pectinidae) inferred from nucleotide sequences of one mitochondrial and three nuclear gene regions

Current knowledge of the evolutionary relationships among scallop species (Mollusca: Bivalvia: Pectinidae) in the Indo-Pacific region is rather scanty. To enhance the understanding of the relationships within this group, phylogenies of nine species of scallops with the majority from coastal regions of Thailand, were reconstructed by maximum parsimony, maximum likelihood, and Bayesian methods using sequences of the 16S rRNA of the mitochondrial genome, and a fragment containing the ITS1, 5.8S and ITS2 genes of the nuclear DNA. The trees that resulted from the three methods of analysis were topologically identical, however, gained different levels of support at some nodes. Nine species were clustered into two major clades, corresponding to two subfamilies (Pectininae and Chlamydinae) of the three currently recognized subfamilies within Pectinidae. Overall, the relationships reported herein are mostly in accordance with the previous molecular studies that used sequences of the mtDNA cytochrome oxidase subunit I, and the classification system based on microsculpture of shell features and morphological characteristics of juveniles. Levels of divergences were different among genes (i.e., the 5.8S gene showed the lowest levels of nucleotide divergence at all levels, whereas the 16S rRNA showed the highest level of variation within species, and ITS2 gene revealed the highest level of divergence at higher levels).

Anisotropic wetting characteristics on submicrometer-scale periodic grooved surface

Submicrometer-scale periodic structures consisting of parallel grooves were prepared on azobenzene-containing multiarm star polymer films by laser interference. The wetting characteristics on the patterned surfaces were studied by contact angle measurements. Macroscopic distortion of water drops was found on such small-scale surface structures, and the contact angles measured from the direction parallel to the grooves were larger than those measured from the perpendicular direction. A thermodynamic model was developed to calculate the change in the surface free energy as a function of the instantaneous contact angle when the three-phase contact line (TPCL) moves along the two orthogonal directions. It was found that the fluctuations, i.e., energy barriers, on the energy versus contact angle curves are crucial to the analysis of wetting anisotropy and contact angle hysteresis. The calculated advancing and receding contact angles from the energy versus contact angle curves were in good agreement with those measured experimentally. Furthermore, with the groove depth increasing, both the degree of wetting anisotropy and the contact angle hysteresis perpendicular to the grooves increased as a result of the increase in the energy barrier. The theoretical critical value of the groove depth, above which the anisotropic wetting appears, was determined to be 16 nm for the grooved surface with a wavelength of 396 nm. On the other hand, the effect of the groove wavelength on the contact angle hysteresis perpendicular to the grooves was also interpreted on the basis of the thermodynamic model. That is, with the wavelength decreasing, the contact angle hysteresis increased due to the increase in the number of energy barriers. These results may provide theoretical evidence for the design and application of anisotropic wetting surface.

An efficient mapreduce-based parallel clustering algorithm for distributed traffic subarea division

Traffic subarea division is vital for traffic system management and traffic network analysis in intelligent transportation systems (ITSs). Since existing methods may not be suitable for big traffic data processing, this paper presents a MapReduce-based Parallel Three-Phase K -Means (Par3PKM) algorithm for solving traffic subarea division problem on a widely adopted Hadoop distributed computing platform. Specifically, we first modify the distance metric and initialization strategy of K -Means and then employ a MapReduce paradigm to redesign the optimized K -Means algorithm for parallel clustering of large-scale taxi trajectories. Moreover, we propose a boundary identifying method to connect the borders of clustering results for each cluster. Finally, we divide traffic subarea of Beijing based on real-world trajectory data sets generated by 12,000 taxis in a period of one month using the proposed approach. Experimental evaluation results indicate that when compared with K -Means, Par2PK-Means, and ParCLARA, Par3PKM achieves higher efficiency, more accuracy, and better scalability and can effectively divide traffic subarea with big taxi trajectory data.

A review of the game-centred approaches to teaching and coaching literature since 2006

Background: In 2006, Oslin and Mitchell published a review of the game-centred approaches (GCAs) to teaching and coaching literature highlighting a number of core concepts thought to provide justification for the use of GCAs including (a) its potential to enhance participant motivation, (b) potential for tactical transfer, and (c) development of decision-making skills and effective decision-makers. Oslin and Mitchell also suggested recommendations for future GCA research.Purpose: The purpose of this paper was threefold: (a) to present a review of Anglophone research into GCAs building on the previous review of Oslin and Mitchell published in 2006; (b) to identify new trends in research since 2006; and (c) to investigate the extent to which the initial suggestions and future research directions suggested by Oslin and Mitchell have been addressed.Data collection: GCA literature since 2006 was searched systematically using a three-phase approach. Phase 1 included initial searches of the EBSCO database using terms associated with GCAs and their acronyms (e.g. TGfU (teaching games for understanding), GS (Game Sense), etc.). Phase 2 expanded the search adopting more generic terms from keywords located in the recent literature (e.g. teaching games, tactical development, game performance, etc.). Multiple searches through the EBSCO database were conducted, whereby key terms were cross-referenced until a saturation point was reached. Phase 3 involved removing those publications that were not empirical, peer reviewed, intervention studies or published in English.Findings: Forty-four studies on GCA implementation were identified and the methodological and substantive nature of these studies was examined. The review noted two positive trends: (a) the expansion of research which included the growth of research on GCAs in Europe and Southeast Asia and (b) an increased amount of research in the affective domain. The review found, however, that a number of key challenges remain within GCA research, which include (a) the need for improved articulation of GCA verification procedures; (b) further assessment of tactical awareness development; (c) extended inquiry about GCAs in coaching contexts; (d) more research into ‘newer’ GCAs (i.e. PP (play practice), IGCM (invasion game competence model) and TDLM (tactical decision learning model)); (e) use of longitudinal research designs; (f) inadequate length of GCA induction and training for teachers and coaches, and (g) examination of GCAs in terms of fitness and special populations.Conclusions: GCA pedagogies are of significant importance as they have the potential to promote change within current adult-centric cultures of youth sport and encourage engagement in physical activity over the life course. To meet these needs, it is recommended that GCA research undergo continued expansion with the use of research designs and data collection techniques that aid the examination of different philosophical understandings of GCAs (e.g. ethnographic, phenomenological and psycho-phenomenological). These are paramount to the exploration of ‘who the individual is’ and ‘how the learner is motivated to continue to participate’ and further permit the in-depth, contextual and ecological analysis of GCA interventions that Oslin and Mitchell recommended in their previous review.

Effects of approach velocity and foot-target characteristics on the visual regulation of step length

Two questions emerge from the literature concerning the perceptual-motor processes underlying the visual regulation of step length. The first concerns the effects of velocity on the onset of visual control (VCO), when visual regulation of step length begins during goal-directed locomotion. The second concerns the effects of different obstacles such as a target or raised surface on step length regulation. In two separate experiments, participants (Experiment 1 & 2: n=12, 6 female, 6 male) walked, jogged, or sprinted towards an obstacle along a 10 m walkway, consisting of two marker-strips with alternating black and white 0.50 m markings. Each experiment consisted of three targeting or obstacle tasks with the requirement to both negotiate and continue moving (run-through) through the target. Five trials were conducted for each task and approach speed, with trials block randomised between the six participants of each gender. One 50 Hz video camera panned and filmed each trial from an elevated position, adjacent to the walkway. Video footage was digitized to deduce the gait characteristics. Results for the targeting tasks indicate a linear relationship between approach velocity and accuracy of final foot placement (r=0.89). When foot placement was highly constrained by the obstacle step length shortened during the entire approach. VCO was found to occur at an earlier tau-margin for lower approach velocities for both experiments, indicating that the optical variable ‘tau' is affected by approach velocity. A three-phase kinematic profile was found for all tasks, except for the take-off board condition when sprinting. Further research is needed to determine whether this velocity affect on VCO is due to ‘whole-body' approach velocity or whether it is a function of the differences between gait modes.