910 resultados para Track works
Resumo:
The determination of the most appropriate procurement method for capital works projects is a challenging task for the Department of Housing and Works (DHW) and other Western Australian State Government Agencies because of the array of assessment criteria that are considered and the procurement methods that are available. A number of different procurement systems can be used to deliver capital works projects such a traditional, design and construct and management. Sub-classifications of these systems have proliferated and continue to emerge in response to market demands. The selection of an inappropriate procurement method may lead to undesirable project outcomes. To facilitate DHW in selecting an appropriate procurement method for its capital works projects, a six step procurement method selection process is presented. The characteristics of the most common forms of procurement method used in Australia are presented. Case studies where procurement methods have been used for specific types of capital works in Western Australia are offered to provide a reference point and learning opportunity for procurement method selection.
Resumo:
This paper reports on the early stages of a design experiment in educational assessment that challenges the dichotomous legacy evident in many assessment activities. Combining social networking technologies with the sociology of education the paper proposes that assessment activities are best understood as a negotiable field of exchange. In this design experiment students, peers and experts engage in explicit, "front-end" assessment (Wyatt-Smith, 2008) to translate holistic judgments into institutional, and potentiality economic capital without adhering to long lists of pre-set criteria. This approach invites participants to use social networking technologies to judge creative works using scatter graphs, keywords and tag clouds. In doing so assessors will refine their evaluative expertise and negotiate the characteristics of creative works from which criteria will emerge (Sadler, 2008). The real-time advantages of web-based technologies will aggregate, externalise and democratise this transparent method of assessment for most, if not all, creative works that can be represented in a digital format.
Resumo:
Purpose: The determination of the most appropriate procurement system for a capital works project is a challenging task for public sector clients considering the array of assessment criteria that are considered and the procurement methods that are available. This is particularly pertinent to the Western Australian public sector where they have had a propensity to use traditional lump sum as the default procurement solution despite knowing that the selection of an inappropriate procurement method may lead to cost and time overruns, claims, and disputes’ on projects. This paper presents a six step procurement method evaluation approach that requires public sector agencies to consider in detail an array of options so as to obtain value for money. Design/methodology/approach: A procurement evaluation approach is developed and is examined using a focus group of 12 participants comprising of a public sector client, project team and key stakeholders. The focus group was used to examine the developed approach in the context of a real-life capital works project. Findings: The procurement method evaluation approach was deemed to be pragmatic and enabled decision-makers to re-evaluate outcomes from previous steps in the process. All focus group participants stated the six step process enabled a recommendation that was grounded in reflection and detailed evaluation. Practical implications: The developed procurement approach has enabled the public sector client evaluate the way in which they view procurement method selection and examine how they obtain ‘value for money’. Originality/value: The six step procurement approach makes use of quantitative and qualitative techniques and is reliant on discourse and reflection in making a procurement method recommendation. Consequently, the approach enables public sector clients to account for the complexities often associated with procurement selection.
Resumo:
This paper proposes a method of enhancing system stability with a distribution static compensator (DSTATCOM) in an autonomous microgrid with multiple distributed generators (DG). It is assumed that there are both inertial and non-inertial DGs connected to the microgrid. The inertial DG can be a synchronous machine of smaller rating while inertia less DGs (solar) are assumed as DC sources. The inertia less DGs are connected through Voltage Source Converter (VSC) to the microgrid. The VSCs are controlled by either state feedback or current feedback mode to achieve desired voltage-current or power outputs respectively. The power sharing among the DGs is achieved by drooping voltage angle. Once the reference for the output voltage magnitude and angle is calculated from the droop, state feedback controllers are used to track the reference. The angle reference for the synchronous machine is compared with the output voltage angle of the machine and the error is fed to a PI controller. The controller output is used to set the power reference of the synchronous machine. The rate of change in the angle in a synchronous machine is restricted by the machine inertia and to mimic this nature, the rate of change in the VSCs angles are restricted by a derivative feedback in the droop control. The connected distribution static compensator (DSTATCOM) provides ride through capability during power imbalance in the microgrid, especially when the stored energy of the inertial DG is not sufficient to maintain stability. The inclusion of the DSATCOM in such cases ensures the system stability. The efficacies of the controllers are established through extensive simulation studies using PSCAD.
Resumo:
Obesity and type 2 diabetes mellitus (T2D) have reached epidemic proportions in many parts of the world with numbers projected to rise dramatically in coming decades (Wang and Lobstein, 2006; Zaninotto et al., 2006). In Australia, and consistent with much of the developed world, the problem has been described as a ‘juggernaut’ that is out of control (Zimmet and James, 2007). Unfortunately the burgeoning problem of non-communicable diseases, including obesity and T2D, is also impacting developing nations as populations are undergoing a nutrition transition (Caballero, 2005). The increased prevalence of overweight and obesity in children, adolescents and adults in both the developed and developing world is consistent with reductions in all forms of physical activity (Brownson et al., 2005). This brief paper provides an overview of the importance of physical activity and an outline of physical activity intervention studies with particular reference to the growing years. As many interventions studies involving physical activity have been undertaken in the context of childhood obesity prevention (Lobstein et al., 2004), and an increasing proportion of the childhood population is overweight or obese, this is a major focus of discussion.