173 resultados para Optimise
Resumo:
Both in developed and developing economies, major public funding is invested in civil infrastructure assets. Efficiency and comfort level of expected and demanded living standards are largely dependant on the management strategies of these assets. Buildings are one of the major & vital assets, which need to be maintained primarily to ensure its functionality by effective & efficient delivery of services and to optimize economic benefits. Not withstanding, public building infrastructure is not considered in Infrastructure report card published by Australian Infrastructure Report Card Alliance Partners (2001). The reason appears to be not having enough data to rate public building infrastructure. American Infrastructure Report Card (2001) gave “School Buildings” ‘d-’ rating, which is below ‘poor’. For effective asset management of building infrastructure, a need emerged to optimise the budget for managing assets, to cope up with increased user expectations, to response effectively to possible asset failures, to deal with ageing of assets and aging populations and to treat other scenarios including technology advancement and non-asset solutions. John (Asset Management, 2001) suggests that in the area of asset management worldwide, UK, Australia and New Zealand are leading.
Resumo:
For the last two decades heart disease has been the highest single cause of death for the human population. With an alarming number of patients requiring heart transplant, and donations not able to satisfy the demand, treatment looks to mechanical alternatives. Rotary Ventricular Assist Devices, VADs, are miniature pumps which can be implanted alongside the heart to assist its pumping function. These constant flow devices are smaller, more efficient and promise a longer operational life than more traditional pulsatile VADs. The development of rotary VADs has focused on single pumps assisting the left ventricle only to supply blood for the body. In many patients however, failure of both ventricles demands that an additional pulsatile device be used to support the failing right ventricle. This condition renders them hospital bound while they wait for an unlikely heart donation. Reported attempts to use two rotary pumps to support both ventricles concurrently have warned of inherent haemodynamic instability. Poor balancing of the pumps’ flow rates quickly leads to vascular congestion increasing the risk of oedema and ventricular ‘suckdown’ occluding the inlet to the pump. This thesis introduces a novel Bi-Ventricular Assist Device (BiVAD) configuration where the pump outputs are passively balanced by vascular pressure. The BiVAD consists of two rotary pumps straddling the mechanical passive controller. Fluctuations in vascular pressure induce small deflections within both pumps adjusting their outputs allowing them to maintain arterial pressure. To optimise the passive controller’s interaction with the circulation, the controller’s dynamic response is optimised with a spring, mass, damper arrangement. This two part study presents a comprehensive assessment of the prototype’s ‘viability’ as a support device. Its ‘viability’ was considered based on its sensitivity to pathogenic haemodynamics and the ability of the passive response to maintain healthy circulation. The first part of the study is an experimental investigation where a prototype device was designed and built, and then tested in a pulsatile mock circulation loop. The BiVAD was subjected to a range of haemodynamic imbalances as well as a dynamic analysis to assess the functionality of the mechanical damper. The second part introduces the development of a numerical program to simulate human circulation supported by the passively controlled BiVAD. Both investigations showed that the prototype was able to mimic the native baroreceptor response. Simulating hypertension, poor flow balancing and subsequent ventricular failure during BiVAD support allowed the passive controller’s response to be assessed. Triggered by the resulting pressure imbalance, the controller responded by passively adjusting the VAD outputs in order to maintain healthy arterial pressures. This baroreceptor-like response demonstrated the inherent stability of the auto regulating BiVAD prototype. Simulating pulmonary hypertension in the more observable numerical model, however, revealed a serious issue with the passive response. The subsequent decrease in venous return into the left heart went unnoticed by the passive controller. Meanwhile the coupled nature of the passive response not only decreased RVAD output to reduce pulmonary arterial pressure, but it also increased LVAD output. Consequently, the LVAD increased fluid evacuation from the left ventricle, LV, and so actually accelerated the onset of LV collapse. It was concluded that despite the inherently stable baroreceptor-like response of the passive controller, its lack of sensitivity to venous return made it unviable in its present configuration. The study revealed a number of other important findings. Perhaps the most significant was that the reduced pulse experienced during constant flow support unbalanced the ratio of effective resistances of both vascular circuits. Even during steady rotary support therefore, the resulting ventricle volume imbalance increased the likelihood of suckdown. Additionally, mechanical damping of the passive controller’s response successfully filtered out pressure fluctuations from residual ventricular function. Finally, the importance of recognising inertial contributions to blood flow in the atria and ventricles in a numerical simulation were highlighted. This thesis documents the first attempt to create a fully auto regulated rotary cardiac assist device. Initial results encourage development of an inlet configuration sensitive to low flow such as collapsible inlet cannulae. Combining this with the existing baroreceptor-like response of the passive controller will render a highly stable passively controlled BiVAD configuration. The prototype controller’s passive interaction with the vasculature is a significant step towards a highly stable new generation of artificial heart.
Resumo:
As the problems involving infrastructure delivery have become more complex and contentious, there has been an acknowledgement that these problems cannot be resolved by any one body working alone. This understanding has driven multi-sectoral collaboration and has led to an expansion of the set of actors, including stakeholders, who are now involved in delivery of infrastructure projects and services. However, more needs to be understood about how to include stakeholders in these processes and the optimal ways of developing the requisite combination of stakeholders to achieve effective outcomes. This thesis draws on stakeholder theory and governance network theory to obtain insights into how three networks delivering public outcomes within the Roads Alliance in Queensland engage with stakeholders in the delivery of complex and sensitive infrastructure services and projects. New knowledge about stakeholders will be obtained by testing a model of Stakeholder Salience and Engagement which combines and extends the stakeholder identification and salience theory (Mitchell, Agle, and Wood, 1997), ladder of stakeholder management and engagement (Friedman and Miles, 2006) and the model of stakeholder engagement and moral treatment of stakeholders (Greenwood, 2007). By applying this model, the broad research question: “Who or what decides how stakeholders are optimally engaged by governance networks delivering public outcomes?” will be addressed. The case studies will test a theoretical model of stakeholder salience and engagement which links strategic management decisions about stakeholder salience with the quality and quantity of engagement strategies for engaging different types of stakeholders. The outcomes of this research will contribute to and extend stakeholder theory by showing how stakeholder salience impacts on decisions about the types of engagement processes implemented. Governance network theory will be extended by showing how governance networks interact with stakeholders through the concepts of stakeholder salience and engagement. From a practical perspective this research will provide governance networks with an indication of how to optimise engagement with different types of stakeholders.
Resumo:
The stakeholder approach which emerged under the auspices of new public management has been in use in public agencies for the past 25 years. However it remains a difficult and demanding task for agencies to determine who their stakeholders are and how to optimise interactions with them. This paper will examine how government agencies identify, classify and engage with stakeholders who have competing demands, differing access to resources and the ability to exert political pressure. To do this, the stakeholder approaches of nine agencies at three levels of government in Queensland were studied. The contribution of this paper is the development of a Stakeholder Classification Model for Public Agencies which could be used to create more focused and relevant stakeholder interventions.
Resumo:
Purpose – The purpose of this paper is to provide a practicable systems-based approach to knowledge management (KM) in a project environment, to encourage organisations to unlock the value in their review processes. It relies on knowledge capture and storage at decision review points, to enrich individual, team and organisational learning during the project life cycle. The project's phases are typically represented horizontally with deliverables (objectives) or project "promises" as the desirable outcomes. The purpose of this paper is to give expression through introducing a vertical dimension to facilitate the KM process. A model is proposed that conceptualises project-specific knowledge drawing on and feeding into the organisation's knowledge management system (KMS) at tactical and strategic levels. Design/methodology/approach – This conceptual paper links concepts from systems theory with KM, to produce a model to identify, collate, and optimise project-based knowledge and integrate it into the management process. Findings – The application of the system theory approach enriches the knowledge generated by a project, and feeds it into the next phase of that project. At the same time, it contributes to the individual's and project team's KM, specifies possible courses of action, together with risks, costs and benefits and thus it expands the organisation's higher level KMS. Research limitations/implications – The concept suggests that the knowledge capture, storage and sharing process may best be undertaken holistically, in view of the systems relationships between the tasks. Systems theory structures this process. Research opportunities include studying the interfaces between levels of KM, in relation to the project's progress. Practical implications – Reconceptualisation of the project as a knowledge creation process may improve the project's progress as well as add to the individual's, project team's, and wider organisation's knowledge base. An example is given. Originality/value – This paper illuminates the broader potential of under-utilised opportunities in well-known management approaches to add dimension to the business project, of knowledge creation, storage and sharing.
Resumo:
With an increase in growing number of aging public building infrastructure globally, there is an opportunity for an efficient life care management rather then mere demolition and rebuild. By carefully implementing appropriate structural engineering practices with facility management, the whole of life cycle costs for public building assets can be optimised and public money can be saved and better utilised elsewhere. A need of decision support tool/methodology which can assist asset manager make better decision among demolish, refurbish, do nothing or rebuilt option for any typical building under consideration is growing in order to optimise maintenance funds. The paper is part of research project focusing on development of such methodology known as residual service life prediction. The paper is mainly focusing on following three major aspects of public building infrastructure; first, issues and challenges in optimisation of maintenance funds, second, residual service life prediction methodology and issues and challenges in the development of such methodology. The paper concludes with the authors’ observations and further research potentials
Resumo:
Generally, major public funding is invested in civil infrastructure assets. The efficiency and comfort level of expected and actual living standards is largely dependant on the management strategies of these assets. Buildings are one of the major & vital assets, which need to be maintained primarily to ensure their functionality by effective & efficient delivery of services and to optimise economic benefits. In Australia, billions of dollars are spent annually managing and maintaining built assets. These assets make up the social and economic infrastructure, which facilitate the essential services to public and business. Buildings are one of the prime & fundamental assets, which need to be managed effectively and efficiently to ensure that related services are delivered economically and sustainably
Resumo:
The literature and anecdotal evidence suggests that that there is more to tenancy selection (firm location) than the profit maximisation drive that traditional neo-classical economic location theory suggests. In the first instance these models assume property markets are rational and perfectly competitive; the CBD office market is clearly neither rational nor perfectly competitive. This fact alone relegates such models to the margins of usefulness for an industry that seeks to satisfy tenant demand in order to optimise returns on capital invested. Acknowledgment of property market imperfections are universally accepted to the extent that all contemporary texts discuss the lack of a coherent centralised market place and incomplete and poorly disseminated information processes as fundamental inadequacies which characterise the property market inefficiencies. Less well researched are the facets of the market which allow the observer to determine market activity to be significantly irrational. One such facet is that of ‘decision maker preferences’. The decision to locate a business operation at one location as opposed to another seems ostensibly a routine choice based on short, medium and long term business objectives. These objectives are derived from a process of strategic planning by one or more individuals whose goal is held to be to optimise outcomes which benefit the business (and presumably those employed within it). However the decision making processes appear bounded by how firms function, the institutional context in which they operate, as well as by opportunistic behaviour by individual decision makers who allow personal preferences to infiltrate and ‘corrupt’ the process. In this way, history, culture, geography, as well as institutions all become significant to the extent that these influence and shape individual behaviour which in turn determine the morphology of individual preferences, as well as providing a conduit for them to take effect. This paper exams historical and current literature on the impact of individual behaviour in the decision making process within organisations as a precursor to an investigation of the tenancy decision making process within the CBD office market. Literature on the topic falls within a number of research disciplines, philosophy, psychology and economics to name a few.
Resumo:
Queensland Department of Main Roads, Australia, spends approximately A$ 1 billion annually for road infrastructure asset management. To effectively manage road infrastructure, firstly road agencies not only need to optimise the expenditure for data collection, but at the same time, not jeopardise the reliability in using the optimised data to predict maintenance and rehabilitation costs. Secondly, road agencies need to accurately predict the deterioration rates of infrastructures to reflect local conditions so that the budget estimates could be accurately estimated. And finally, the prediction of budgets for maintenance and rehabilitation must provide a certain degree of reliability. This paper presents the results of case studies in using the probability-based method for an integrated approach (i.e. assessing optimal costs of pavement strength data collection; calibrating deterioration prediction models that suit local condition and assessing risk-adjusted budget estimates for road maintenance and rehabilitation for assessing life-cycle budget estimates). The probability concept is opening the path to having the means to predict life-cycle maintenance and rehabilitation budget estimates that have a known probability of success (e.g. produce budget estimates for a project life-cycle cost with 5% probability of exceeding). The paper also presents a conceptual decision-making framework in the form of risk mapping in which the life-cycle budget/cost investment could be considered in conjunction with social, environmental and political issues.
Resumo:
Australias civil infrastructure assets of roads, bridges, railways, buildings and other structures are worth billions of dollars. To effectively manage road infrastructures, road agencies firstly need to optimise the expenditure for data collection whilst not jeopardising the reliability in using the optimised data to predict maintenance and rehabilitation costs. Secondly, road agencies need to accurately predict the deterioration rates of infrastructures to reflect local conditions so that the budget estimates can be accurately calculated. Finally, the prediction of budgets for maintenance and rehabilitation must be reasonably reliable.
Resumo:
LCADesign software package is a real-time environmental impact calculator for commercial property that works directly from the building designer's model. It enables developers, building designers, architects, engineers, builders, manufacturers and government bodies to optimise the eco-impact of a building as the design model evolves instead of waiting months for expert analysis. By integrating with the Building Information Models (BIMs) generated by 3D computer-aided drafting, LCADesign builds eco-efficiency into the design stage and measures the environmental values and risks of materials in commercial buildings
Resumo:
In line with developments overseas Australian clients are turning to considerations of value in project procurement. Until the 1980s the industry operated in a largely traditional manner however the extremely adversarial behaviour exhibited during towards the end of the decade led to a number of significant events and initiatives including the publication of “No Dispute”, the Gyles Royal Commission into the Building Industry, the Construction Industry Development Agency (CIDA) and the work of the Australian Procurement and Construction Council (APCC). A number of research projects in progress in the CRC for Construction Innovation (CRC CI) are focussing on the assessment of value and methodologies to support the delivery of value in the procurement and management of engineering and construction projects. This paper charts the emergence of several key drivers in the process and illustrates how they can be integrated into a comprehensive Decision Support System that balances value to stakeholders with project imperatives and incorporates a lessons learned data base which enriches the decision making process to optimise delivery method design and selection.
Resumo:
The healing process for bone fractures is sensitive to mechanical stability and blood supply at the fracture site. Most currently available mechanobiological algorithms of bone healing are based solely on mechanical stimuli, while the explicit analysis of revascularization and its influences on the healing process have not been thoroughly investigated in the literature. In this paper, revascularization was described by two separate processes: angiogenesis and nutrition supply. The mathematical models for angiogenesis and nutrition supply have been proposed and integrated into an existing fuzzy algorithm of fracture healing. The computational algorithm of fracture healing, consisting of stress analysis, analyses of angiogenesis and nutrient supply, and tissue differentiation, has been tested on and compared with animal experimental results published previously. The simulation results showed that, for a small and medium-sized fracture gap, the nutrient supply is sufficient for bone healing, for a large fracture gap, non-union may be induced either by deficient nutrient supply or inadequate mechanical conditions. The comparisons with experimental results demonstrated that the improved computational algorithm is able to simulate a broad spectrum of fracture healing cases and to predict and explain delayed unions and non-union induced by large gap sizes and different mechanical conditions. The new algorithm will allow the simulation of more realistic clinical fracture healing cases with various fracture gaps and geometries and may be helpful to optimise implants and methods for fracture fixation.
Resumo:
Planar busbar is a good candidate to reduce interconnection inductance in high power inverters compared with cables. However, power switching components with fast switching combined with hard switched-converters produce high di/dt during turn off time and busbar stray inductance then becomes an important issue which creates overvoltage. It is necessary to keep the busbar stray inductance as low as possible to decrease overvoltage and Electromagnetic Interference (EMI) noise. In this paper, the effect of different transient current loops on busbar physical structure of the high-voltage high-level diode-clamped converters will be highlighted. Design considerations of proper planar busbar will also be presented to optimise the overall design of diode-clamped converters.
Resumo:
Introduction: Five-year survival from breast cancer in Australia is 87%. Hence, ensuring a good quality of life (QOL) has become a focal point of cancer research and clinical interest. Exercise during and after treatment has been identified as a potential strategy to optimise QOL of women diagnosed with breast cancer.----- Methods: Exercise for Health is a randomised controlled trial of an eight-month, exercise intervention delivered by Exercise Physiologists. An objective of this study was to assess the impact of the exercise program during and following treatment on QOL. Queensland women diagnosed with unilateral breast cancer in 2006/07 were eligible to participate. Those living in urban-Brisbane (n=194) were allocated to either the face-to-face exercise group, the telephone exercise group, or the usual-care group, and those living in rural Queensland (n=143) were allocated to the telephone exercise group or the usual-care group. QOL, as assessed by the Functional Assessment of Cancer Therapy-Breast (FACT-B+4) questionnaire, was measured at 4-6 weeks (pre-intervention), 6 months (mid-intervention) and 12 months (three months post-intervention) post-surgery.----- Results: Significant (P<0.01) increases in QOL were observed between pre-intervention and three months post-intervention 12 months post-surgery for all women. Women in the exercise groups experienced greater mean positive changes in QOL during this time (+10 points) compared with the usual-care groups (+5 to +7 points) after adjusting for baseline QOL. Although all groups experienced an overall increase in QOL, approximately 20% of urban and rural women in the usual-care groups reported a decline in QOL, compared with 10% of women in the exercise groups.----- Conclusions: This work highlights the potential importance of participating in physical activity to optimise QOL following a diagnosis of breast cancer. Results suggest that the telephone may be an effective medium for delivering exercise counselling to newly diagnosed breast cancer patients.