Designing a new robust on-line secondary path modeling technique for feedforward active noise control systems

Several approaches have been introduced in the literature for active noise control (ANC) systems. Since the filtered-x least-mean-square (FxLMS) algorithm appears to be the best choice as a controller filter, researchers tend to improve performance of ANC systems by enhancing and modifying this algorithm. This paper proposes a new version of the FxLMS algorithm, as a first novelty. In many ANC applications, an on-line secondary path modeling method using white noise as a training signal is required to ensure convergence of the system. As a second novelty, this paper proposes a new approach for on-line secondary path modeling on the basis of a new variable-step-size (VSS) LMS algorithm in feed forward ANC systems. The proposed algorithm is designed so that the noise injection is stopped at the optimum point when the modeling accuracy is sufficient. In this approach, a sudden change in the secondary path during operation makes the algorithm reactivate injection of the white noise to re-adjust the secondary path estimate. Comparative simulation results shown in this paper indicate the effectiveness of the proposed approach in reducing both narrow-band and broad-band noise. In addition, the proposed ANC system is robust against sudden changes of the secondary path model.

An efficient online secondary path estimation for feedback active noise control systems

In practical cases for active noise control (ANC), the secondary path has usually a time varying behavior. For these cases, an online secondary path modeling method that uses a white noise as a training signal is required to ensure convergence of the system. The modeling accuracy and the convergence rate are increased when a white noise with a larger variance is used. However, the larger variance increases the residual noise, which decreases performance of the system and additionally causes instability problem to feedback structures. A sudden change in the secondary path leads to divergence of the online secondary path modeling filter. To overcome these problems, this paper proposes a new approach for online secondary path modeling in feedback ANC systems. The proposed algorithm uses the advantages of white noise with larger variance to model the secondary path, but the injection is stopped at the optimum point to increase performance of the algorithm and to prevent the instability effect of the white noise. In this approach, instead of continuous injection of the white noise, a sudden change in secondary path during the operation makes the algorithm to reactivate injection of the white noise to correct the secondary path estimation. In addition, the proposed method models the secondary path without the need of using off-line estimation of the secondary path. Considering the above features increases the convergence rate and modeling accuracy, which results in a high system performance. Computer simulation results shown in this paper indicate effectiveness of the proposed method.

Coping resources, coping strategies and adaptation to organisational change : direct or buffering effects?

This study examined the effects of personal and social resources, coping strategies and appraised stress on employees' levels of anxiety and depression. In relation to the effects of resources and coping strategies, two different models were tested. The main effects model proposes that, irrespective of the level of stress, coping resources and coping strategies have direct effects on well-being. In contrast, the buffering model predicts that the buffering effects of coping resources and strategies are only evident at high levels of stress. One hundred lawyers completed a structured self-administered questionnaire that measured their personal and social resources, use of problem-focused and emotion-focused coping strategies, and appraisals of the stressfulness of the situation. Results revealed generally strong support for the main effects model in the prediction of employee levels of anxiety and depression. Lower levels of anxiety were linked to judgements of lower levels of organizational change, greater self-confidence, greater internality of control beliefs and less use of emotion-focused coping strategies. Lower levels of depression in employees were also linked to judgements of lower levels of organizational change, greater use of resources and less appraised stress. There was only limited support for the buffering effects model. Due to the small size of the sample, the findings need to be explored further in other contexts.

Changes in profit as market conditions change : an historical study of a building firm

This paper analyses the profits from 221 construction projects undertaken by an Australian building firm in the period 1910–1938 and examines the factors that influence the firm's profit levels. This involves a series of multiple regression analyses with three dependent variables representing profit and 26 independent variables representing economic conditions and project characteristics. From these, 11 models are derived of which two are chosen as having the best explanatory power in explaining approximately 72% of the variability in profit levels movements. The results show that unemployment, interest rates, level of construction activity in the state, change of wage level, inflation rate of building material and project value significantly influenced the firm's profit level during the period.

Preparation and thermal energy storage properties of paraffin/calcined diatomite composites as form-stable phase change materials

A composite paraffin-based phase change material (PCM) was prepared by blending composite paraffin and calcined diatomite through the fusion adsorption method. In this study, raw diatomite was purified by thermal treatment in order to improve the adsorption capacity of diatomite, which acted as a carrier material to prepare shape-stabilized PCMs. Two forms of paraffin (paraffin waxes and liquid paraffin) with different melting points were blended together by the fusion method, and the optimum mixed proportion with a suitable phase-transition temperature was obtained through differential scanning calorimetry (DSC) analysis. Then the prepared composite paraffin was adsorbed in calcined diatomite. The prepared paraffin/calcined diatomite composites were characterized by the scanning electron microscope (SEM) and Fourier transformation infrared (FT-IR) analysis techniques. Thermal energy storage properties of the composite PCMs were determined by DSC method. DSC results showed that there was an optimum adsorption ratio between composite paraffin and calcined diatomite and the phase-transition temperature and the latent heat of the composite PCMs were 33.04 ◦C and 89.54 J/g, respectively. Thermal cycling test of composite PCMs showed that the prepared material is thermally reliable and chemically stable. The obtained paraffin/calcined diatomite composites have proper latent heat and melting temperatures, and show practical significance and good potential application value.

Climate change-related corporate governance information : an explanation of the difference between the supply of and demand for such information

This study investigates the gap between the climate change-related corporate governance information being disclosed by companies, and the information sought by stakeholders. To accomplish this objective we utilised previous research on stakeholder demand for information, and we conducted in-depth interviews with six corporate representatives from major Australian emission-intensive companies. Having gained and documented a rich insight into the potential factors responsible for the current gap in disclosure we find that the existence of an expectations gap; the perceived cost of providing commercially sensitive information; the limited accountability being accepted by the corporate managers; and, a lack of stakeholder pressure together contribute to the lack of disclosure. In highlighting the gap in disclosure, this study suggests strategies to reduce the gap in climate change-related corporate governance disclosures.

Towards the development of a best practice index for the disclosure of organisations' climate change-related corporate governance practices

The aim of this study is to develop a disclosure guide for climate-change-related corporate governance (CCCG) practices. Drawing from existing climate change policy guidelines together with content analysis of leading Australian companies’ disclosure practices, we develop a best practice index for the disclosure of CCCG practises. The best practice index is further informed, validated and refined by the contribution of experts from a range of stakeholder groups. Our index represents the most comprehensive list generated to date, utilising experts’ opinions, in relation to CCCG disclosure practices. This CCCG disclosure index would be useful for companies seeking to provide information in relation their CCCG practices

Corporate climate change-related governance practices and related disclosures : evidence from Australia

This paper investigates the climate change-related corporate governance disclosure practices of five major Australian energy-intensive companies over a 16-year period. In doing so, a content analysis instrument is developed to identify disclosures made in relation to various policies and procedures the organisations have in place for addressing the issues associated with climate change. This instrument is applied to the respective companies' annual reports and sustainability reports. An increasing trend is found in companies' climate change-related corporate governance disclosures over time; however, in many instances the disclosures provide limited insights into the climate change-related risks and opportunities confronting the sample companies.

The classic white formal shirt : a powerful emblem of social change

The classic white formal shirt is a widely and readily familiar object with considerable historical cultural significance to diverse social groups, and is therefore deserving of iconic status. For more than two hundred years, this singular item of apparel has been able to define and represent status, wealth, gender shifts and fashion norms. This garment, which has historically been relinquished to undergarment status, deserves an escalation of standing. The classic white formal shirt, for both men and women, can be used as a mirror to map considerable social change and the diversity of influence can be traced through many examples, including: Beau Brummell’s dandy status with his legendry white shirting; the Gibson Girl with her decorated white shirt style blouse defining ideals of female beauty; IBM business employees in the 1920s marketing trustworthiness through the uniformity of white shirts; the fictional advertising creation of the Arrow Collar Man, with his rigid white shirt, promoting American masculine ideals; and the iconic 1980s Hugo Boss style crisp white dress shirt symbolising power. The origins of the influence of the white shirt can be best traced in the Victorian era where it was an important symbol of wealth and class distinction and a powerful emblem of sobriety and uniformity for men. The pure white colour fulfilled masculine ideals of resolute austerity and the shirt, through its constancy, epitomised conformity and dependability. For women, the white cloth of the ‘shirt-waist’ from this period was also linked to ideals of cleanliness and purity and was seen as an iconic symbol of the new independent working class woman. This paper will propose that the classic white formal shirt, for both men and women, has been a powerful marker of social shifts in Western society and this underrated item of apparel, with limited scholarly writing, is worthy of iconic status. The discussion will trace the historical development of both the men’s and women’s white shirt, each with their own unique history, and in doing so highlight the considerable historical cultural significance associated with the white formal shirt. Discussed first will be the men’s white formal shirt.

Stakeholder pressures and climate change disclosure : Australian evidence

This paper investigates the stakeholder pressures behind corporate accountability and disclosures in relation to climate change. By means of a questionnaire survey, the study focuses on ascertaining the views of a sample of stakeholder groups such as government bodies, institutional investors, environmental NGOs, media accounting professionals, and researchers to examine their perceptions of pressures upon Australian corporations to be accountable in relation to climate change. Prior social and environmental research found that NGOs (Deegan and Blomquist, 2006; Tilt, 1994) and the media (Brown and Deegan, 1996; Islam and Deegan, 2010) were powerful stakeholder groups influencing corporate social and environmental disclosure practices. Our paper finds that along with NGOs and the media, institutional investors and regulators (governments) are equally important and powerful actors for applying pressure for corporate accountability in relation to climate change. Based on the findings of the paper, we would argue that climate change is an issue with no single stakeholder group involved, rather it is a set of stakeholder groups including regulators, institutional investors, the media, and NGOs who demand corporations to be accountable.

Benefiting white noise in developing feedforward active noise control systems

In many applications of active noise control (ANC), an online secondary path modelling method using a white noise as a training signal is required to ensure convergence of the system. The modelling accuracy and the convergence rate increase when a white noise with larger variance is used, however larger the variance increases the residual noise, which decreases performance of the system. The proposed algorithm uses the advantages of the white noise with larger variance to model the secondary path, but the injection is stopped at the optimum point to increase performance of the system. In this approach, instead of continuous injection of the white noise, a sudden change in secondary path during the operation makes the algorithm to reactivate injection of the white noise to adjust the secondary path estimation. Comparative simulation results shown in this paper indicate effectiveness of the proposed method.

Nutritional analysis of gastric contents and body condition score at a single time point in feral horses in Australia

Objective: To determine the impact of a free-choice diet on nutritional intake and body condition of feral horses. Animals: Cadavers of 41 feral horses from 5 Australian locations. Procedures: Body condition score (BCS) was determined (scale of 1 to 9), and the stomach was removed from horses during postmortem examination. Stomach contents were analyzed for nutritional variables and macroelement and microelement concentrations. Data were compared among the locations and also compared with recommended daily intakes for horses. Results: Mean BCS varied by location; all horses were judged to be moderately thin. The BCS for males was 1 to 3 points higher than that of females. Amount of protein in the stomach contents varied from 4.3% to 14.9% and was significantly associated with BCS. Amounts of water-soluble carbohydrate and ethanol-soluble carbohydrate in stomach contents of feral horses from all 5 locations were higher than those expected for horses eating high-quality forage. Some macroelement and microelement concentrations were grossly excessive, whereas others were grossly deficient. There was no evidence of ill health among the horses. Conclusions and Clinical Relevance: Results suggested that the diet for several populations of feral horses in Australia appeared less than optimal. However, neither low BCS nor trace mineral deficiency appeared to affect survival of the horses. Additional studies on food sources in these regions, including analysis of water-soluble carbohydrate, ethanol-soluble carbohydrate, and mineral concentrations, are warranted to determine the provenance of such rich sources of nutrients. Determination of the optimal diet for horses may need revision.

Empowering the school community for change : an evaluation of participation in the Ashgrove Healthy School Environment Project

The purpose of this study was to evaluate aspects of participation in a participatory action research project, the Ashgrove Healthy School Environment Project. Participatory action research is a form of research that creates change as an explicit part of the research process and requires the active participation of those by and for whom the research is being conducted. This study arose from concems by this researcher, who is also a co-facilitator of the project, that levels of participation were not as extensive as one might have hoped and that this seemingly low level would have a negative impact on the continuing participation of those already involved. Specifically. this evaluation sought to uncover the reasons that prompted participation, to identify structural barriers to initial involvement and to uncover participants' perceptions of the process, including barriers and opportunities. It also sought to record evidence of any shift in decision making and to draw implications about the findings that could assist the project, the school, other schools and the wider community. This evaluation involved focus group discussions and interviews with participants actively involved in the school project. The purpose was to uncover their views, feelings and perceptions about their participation and the participatory processes in use generally. It also included some examination of school documents and newsletters and as also drawn on the reflections of this 'insider' researcher, based on two years of involvement in facilitating the project. The findings that emerge from this study are heartening. Rather than feeling anxious about the long-term sustainability of the project, this researcher now feels more confident about its achievements, both in terms of the changes that have occurred in the school and about the participatory processes and levels of participation. Whilst the evaluation has identified a number of barriers, both institutional, personal and project related, it has also identified several key factors that serve to promote participation.

Evaluating Communication for Development : A Framework for Social Change

Evaluating Communication for Development presents a comprehensive framework for evaluating communication for development (C4D). This framework combines the latest thinking from a number of fields in new ways. It critiques dominant instrumental, accountability-based approaches to development and evaluation and offers an alternative holistic, participatory, mixed methods approach based on systems and complexity thinking and other key concepts. It maintains a focus on power, gender and other differences and social norms. The authors have designed the framework as a way to focus on achieving sustainable social change and to continually improve and develop C4D initiatives. The benefits and rigour of this approach are supported by examples and case studies from a number of action research and evaluation capacity development projects undertaken by the authors over the past fifteen years. Building on current arguments within the fields of C4D and development, the authors reinforce the case for effective communication being a central and vital component of participatory forms of development, something that needs to be appreciated by decision makers. They also consider ways of increasing the effectiveness of evaluation capacity development from grassroots to management level in the development context, an issue of growing importance to improving the quality, effectiveness and utilisation of monitoring and evaluation studies in this field. The book includes a critical review of the key approaches, methodologies and methods that are considered effective for planning evaluation, assessing the outcomes of C4D, and engaging in continuous learning. This rigorous book is of immense theoretical and practical value to students, scholars, and professionals researching or working in development, communication and media, applied anthropology, and evaluation and program planning.