Condition assessment of timber utility poles based on a hierarchical data fusion model

This paper proposes a novel hierarchical data fusion technique for the non-destructive testing (NDT) and condition assessment of timber utility poles. The new method analyzes stress wave data from multisensor and multiexcitation guided wave testing using a hierarchical data fusion model consisting of feature extraction, data compression, pattern recognition, and decision fusion algorithms. The researchers validate the proposed technique using guided wave tests of a sample of in situ timber poles. The actual health states of these poles are known from autopsies conducted after the testing, forming a ground-truth for supervised classification. In the proposed method, a data fusion level extracts the main features from the sampled stress wave signals using power spectrum density (PSD) estimation, wavelet packet transform (WPT), and empirical mode decomposition (EMD). These features are then compiled to a feature vector via real-number encoding and sent to the next level for further processing. Principal component analysis (PCA) is also adopted for feature compression and to minimize information redundancy and noise interference. In the feature fusion level, two classifiers based on support vector machine (SVM) are applied to sensor separated data of the two excitation types and the pole condition is identified. In the decision making fusion level, the Dempster–Shafer (D-S) evidence theory is employed to integrate the results from the individual sensors obtaining a final decision. The results of the in situ timber pole testing show that the proposed hierarchical data fusion model was able to distinguish between healthy and faulty poles, demonstrating the effectiveness of the new method.

Prediction of stress-strain behaviors in steels using an integrated constitutive, FEM and ANN model

Austenitic steels with a carbon content of 0.0037 to 0.79 wt% C are torsion tested and modeled using a physically based constitutive model and an Integrated Phenomenological and Artificial neural Network (IPANN) model. The prediction of both the constitutive and IPANN models on steel 0.017 wt% C is then evaluated using a finite element (FEM) code ABAQUS with different reduction in the thickness after rolling through one roll stand. It is found that during the rolling process, the prediction accuracy of the reaction force from FEM simulation for both constitutive and IPANN models depends on the strain achieved (average reduction in thickness). By integrating FEM into IPANN model and introducing the product of strain and stress as an input of the ANN model, the accuracy of this integrated FEM and IPANN model is higher than either the constitutive or IPANN model.

Design of LabVIEW® - based software for the control of sequential injection analysis instrumentation for the determination of morphine.

LabVIEW^®-based software for the automation of a sequential injection analysis instrument for the determination of morphine is presented. Detection was based on its chemiluminescence reaction with acidic potassium permanganate in the presence of sodium polyphosphate. The calibration function approximated linearity (range 5 × 10 ^-10 to 5 × 10 ^-6M) with a line of best fit of y = 1.05 x + 8.9164 (R² = 0.9959), where y is the log₁₀ signal (mV) and x is the log₁₀ morphine concentration (M). Precision, as measured by relative standard deviation, was 0.7% for five replicate analyses of morphine standard (5 × 10^-8_M). The limit of detection (3 σ) was determined as 5 × 10^-11 M morphine.

A finite element simulation of micro-mechanical frictional behaviour in metal forming

Friction is a critical factor for sheet metal forming (SMF). The Coulomb friction model is usually used in most finite element (FE) simulation for SMF. However, friction is a function of the local contact deformation conditions, such as local pressure, roughness and relative velocity. Frictional behaviour between contact surfaces can be based on three cases: boundary, hydrodynamic and mixed lubrication. In our microscopic friction model based on the finite element method (FEM), the case of dry contact between sheet and tool has been considered. In the view of microscopic geometry, roughness depends upon amplitude and wavelength of surface asperities of sheet and tool. The mean pressure applied on the surface differs from the pressure over the actual contact area. The effect of roughness (microscopic geometric condition) and relative speed of contact surfaces on friction coefficient was examined in the FE model for the microscopic friction behaviour. The analysis was performed using an explicit FE formulation. In this study, it was found that the roughness of deformable sheet decreases during sliding and the coefficient of friction increases with increasing roughness of contact surfaces. Also, the coefficient of friction increases with the increase of relative velocity and adhesive friction coefficient between contact surfaces.

A shape error metric for sheet metal forming and its application to springback

There are many variations within sheet metal forming, some of which are manifest in the final geometry of the formed component. It is important that this geometric variation be quantified and measured for use in a process or quality control system. The contribution of this paper is to propose a novel way of measuring the geometric difference between the desired shape and an actual formed "U" channel. The metric is based upon measuring errors in terms of the significant manufacturing variations. The metric accords with the manually measured errors of the channel set. The shape error metric is then extended to develop a simple empirical, whole-component, springback error measure. The springback error measure combines into one value all the angle springback and side wall curl geometric errors for a single channel. Two trends were observed: combined springback decreases when the blank holder force is increased; and the combined springback marginally decreases when the die radii is increased.

Role of peer support and emotional expression on posttraumatic stress disorder in student paramedics

This exploratory study contrasted and tested the predictive value of the reverse buffering hypothesis of social support and the information processing model of posttraumatic stress disorder (PTSD) in an investigation of trauma-related symptomatology (TRS) in a single sample of 42 student paramedics. Participants completed several anonymous self-report measures of PTSD symptomatology, peer social support, and attitude toward emotional expression. Regression-based path analyses did not support either theory of PTSD in this population. A path model of PTSD in student paramedics was subsequently developed, indicating that a direct relationship exists between duty-related trauma exposure, dysfunctional peer social support, and students' negative attitudes toward emotional expression. This new model accounted for 30% of the variance in student paramedics' TRS.

End-user control in web-based electronic services : a case study

This paper reports a case study of end-user control in delivery of Web-based electronic services. The case study concentrates the adoption of a Web-based electronic system being implemented in processing student’s admission applications on a Web site. The end-user’s control interface provides information on the detail existing in the Web-based electronic service. This insight into end-user synthesis in developing effective control in Web service environment relates to ease of use in doing the task. To assume the leverage of end-user control strictly on the basis of the Web service usage would limit the purpose of understanding. Rather it is suggested that it would be better to develop an approach to study the end-user ease of use interface in doing the task with the user’s perception towards Web-based interactivity.

Stress analysis of compression of aluminium with rotating tools

Compression tests carried out on aluminium specimens showed that when the die was rotated the compression load dropped. A slab method is employed to examine this process. The load reduction is explained by the deviation of friction vector due to the relative circumferential movement between the die and the material. This mechanism is incorporated into a theoretical model and an expression is derived for compression pressure. Analytical solutions established compare favourably with experimental results. It is also shown that there is a limitation to the load reduction: the compressive load can never be lower than 70 percent of the yield limit.

Analysis of work hardening and recrystallization during the hot working of steel using a statistically based internal variable model

A mathematical model has been developed which describes the hot deformation and recrystallization behavior of austenite using a single internal variable: dislocation density. The dislocation density is incorporated into equations describing the rate of recovery and recrystallization. In each case no distinction is made between static and dynamic events, and the model is able to simulate multideformation processes. The model is statistically based and tracks individual populations of the dislocation density during the work-hardening and softening phases. After tuning using available data the model gave an accurate prediction of the stress–strain behavior and the static recrystallization kinetics for C–Mn steels. The model correctly predicted the sensitivity of the post deformation recrystallization behavior to process variables such as strain, strain rate and temperature, even though data for this were not explicitly incorporated in the tuning data set. In particular, the post dynamic recrystallization (generally termed metadynamic recrystallization) was shown to be largely independent of strain and temperature, but a strong function of strain rate, as observed in published experimental work.

Evidence-based mental health nursing in Australia: our history and our future

This paper will develop a discussion related to evidence-based knowledge for mental health nursing, arguing for a historical component to be included in the comprehensive degree programme that will offer significant insights into mental health nursing knowledge from historical information and constructing implications for contemporary practice. Our understanding of the present is clearer by this looking back and forth and by adding meaning (and what the meanings mean) to what historically preceded. It allows the history of psychiatry to be a much more productive, useful, and a continual source of wisdom for the here and now. This blending of past knowledge with contemporary inquiry can offer depth in mental health nursing practices by forming a context for practice for the beginning nurse practitioner.

Composition dependency of the glass forming ability (GFA) in Mg—Ni—Si system by mechanical alloying

The pure elemental powder mixtures with the compositions of Mg₆₅Ni_xSi₃₅−_x (x = 10, 20, 25, 33 at.%) were subject to high-energy ball mill, and the structures of the mixtures at different intervals of milling were characterised by X-ray diffraction (XRD). The compositional dependency of the glass forming ability (GFA) in Mg–Ni–Si system was evaluated based on the experimental results and the theoretical calculation. The compositional dependency of GFA in Mg–Ni–Si system can be understood well by comparing the enthalpies of the crystalline and amorphous phases based on the Miedema's theory for the formation enthalpy of alloys. Increasing the Ni/Mg ratio and/or decreasing Si content can improve the amorphous formability. The calculation results might be of great help in optimising the composition with high GFA in Mg–Ni–Si system.

Multi-scale rheological model for discontinuous phenomena in materials under deformation conditions

A study of possibilities given by the developed Cellular Automata–Finite Element (CAFE) multi-scale model for prediction of the initiation and propagation of micro-shear bands and shear bands in metallic materials subjected to plastic deformation is described in the paper. Particular emphasis in defining the criterion for initiation of micro-shear and shear bands, as well as in defining the transition rules for the cellular automata, is put on accounting for the physical aspects of those phenomena occurring in two different scales in the material. The proposed approach led to the creation of the real multi-scale model of strain localization. This model predicts material behavior in various thermo-mechanical processes. Selected examples of applications of the developed model to simulations of metal forming processes, which involve strain localization, are presented in the paper. An approach based on the Smoothed Particle Hydrodynamic, which allows to overcome difficulties with remeshing in the traditional CAFE method, is presented in the paper as well. In this approach remeshing becomes possible and mesh distortion, which limits application of the CAFE method to simple deformation processes, is eliminated.

Depression, anxiety and stress in women following acute coronary syndrome: implications for secondary prevention

Objective
To document incidence of depression, anxiety, and stress in women more than 6 months following an acute coronary syndrome.

Design
Participants were identified from a coronary care unit database. The Depression Anxiety Stress Scales 21 (DASS 21) was sent to potential participants via postal survey.

Setting
A metropolitan teaching hospital in Melbourne, Australia.

Participants
The cohort of women was aged between 55 and 70 years. They had been admitted to hospital with a diagnosis of acute coronary syndrome (ACS) between 6 and 14 months prior to participating in this study.

Main outcome measures
Scores on Depression, Anxiety, and Stress Scale (DASS 21).

Results
Of the 117 posted questionnaires, 39 women with a mean age of 63 (S.D. 4.97) responded to the survey, representing a response rate of 33.3%. Most participants scored within normal levels of depression (66.7%), anxiety (60.5%), and stress (70.3%), however, mild to extremely severe levels of each construct (33.4%, 39.6%, and 29.7%, respectively) were found.

Conclusions
The reporting of elevated levels of depression, anxiety and stress in a subset of women more than 6 months following an ACS event underscores the importance of ongoing screening for risk factors impacting on psychological well-being and the inclusion of this information in education and counseling strategies in both the inpatient and outpatient settings. Based on these pilot data, consideration of a screening system in the immediate post discharge period for women at risk and an education or support service are recommended.

Feasibility study of partial recrystallisation in multi-pass hot deformation process and application to calculation of mean flow stress

A feasibility study for handling the partial recrystallisation in multi-pass hot deformation where the heterogeneity of microstructure of deformed austenite is inherently accompanied is presented. The proposed model is based on modification of the conventional model in which the microstructure of deformed austenite at each pass is simply taken as being homogeneous during the multi-pass deformation. The usefulness of the modified model has been demonstrated by applying it to a four-pass oval–round (or round–oval) rod rolling sequence. The recrystallised fraction, austenite grain size (AGS) and mean flow stress at each pass computed from the modified model has been compared with those from the conventional model. The result showed that the recrystallisation behaviour and evolution of AGS at a given pass were dependent on the modelling method of the partial recrystallisation in the multi-pass rolling for the case studied. As the rolling speed increased, the difference between the mean flow stresses calculated by the conventional model and the proposed model was gradually larger in accordance with the contribution of partial recrystallisation.