778 resultados para Numerical Evaluation


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In urban environments road traffic volumes are increasing and the density of living is becoming higher. As a consequence the urban community is being exposed to increasing levels of road traffic noise. It is also evident that the noise reduction potential of within-the-road-reserve treatments such as noise barriers, mounding and pavement surfacing has been exhausted. This paper presents a strategy that involves the comparison of noise ameliorative treatments both within and outside the road reserve. The noise reduction resulting from the within-the-road-reserve component of treatments has been evaluated using a leading application of the CoRTN Model, developed by the UK Department of Transport 1988 [1], and the outside road reserve treatment has been evaluated in accordance with the Australian Standard 3671, Acoustics – Road traffic noise intrusion – Building sitting and construction [5]. The evaluation of noise treatments has been undertaken using a decision support tool (DST) currently being developed under the research program conducted at RMIT University and Department of Main Roads, Queensland. The case study has been based on data from a real project in Queensland, Australia. The research described here was carried out by the Australian Cooperative Research Centre for Construction Innovation [9], in collaboration with Department of Main Roads, Queensland, Department of Public Works, Queensland, Arup Pty. Ltd., Queensland University of technology and RMIT University.

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This paper aims to develop the methodology and strategy for concurrent finite element modeling of civil infrastructures at the different scale levels for the purposes of analyses of structural deteriorating. The modeling strategy and method were investigated to develop the concurrent multi-scale model of structural behavior (CMSM-of-SB) in which the global structural behavior and nonlinear damage features of local details in a large complicated structure could be concurrently analyzed in order to meet the needs of structural-state evaluation as well as structural deteriorating. In the proposed method, the “large-scale” modeling is adopted for the global structure with linear responses between stress and strain and the “small-scale” modeling is available for nonlinear damage analyses of the local welded details. A longitudinal truss in steel bridge decks was selected as a case to study how a CMSM-of-SB was developed. The reduced-scale specimen of the longitudinal truss was studied in the laboratory to measure its dynamic and static behavior in global truss and local welded details, while the multi-scale models using constraint equations and substructuring were developed for numerical simulation. The comparison of dynamic and static response between the calculated results by different models indicated that the proposed multi-scale model was found to be the most efficient and accurate. The verification of the model with results from the tested truss under the specific loading showed that, responses at the material scale in the vicinity of local details as well as structural global behaviors could be obtained and fit well with the measured results. The proposed concurrent multi-scale modeling strategy and implementation procedures were applied to Runyang cable-stayed bridge (RYCB) and the CMSM-of-SB of the bridge deck system was accordingly constructed as a practical application.

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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.

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Differential axial shortening, distortion and deformation in high rise buildings is a serious concern. They are caused by three time dependent modes of volume change; “shrinkage”, “creep” and “elastic shortening” that takes place in every concrete element during and after construction. Vertical concrete components in a high rise building are sized and designed based on their strength demand to carry gravity and lateral loads. Therefore, columns and walls are sized, shaped and reinforced differently with varying concrete grades and volume to surface area ratios. These structural components may be subjected to the detrimental effects of differential axial shortening that escalates with increasing the height of buildings. This can have an adverse impact on other structural and non-structural elements. Limited procedures are available to quantify axial shortening, and the results obtained from them differ because each procedure is based on various assumptions and limited to few parameters. All these prompt to a need to develop an accurate numerical procedure to quantify the axial shortening of concrete buildings taking into account the important time varying functions of (i) construction sequence (ii) Young’s Modulus and (iii) creep and shrinkage models associated with reinforced concrete. General assumptions are refined to minimize variability of creep and shrinkage parameters to improve accuracy of the results. Finite element techniques are used in the procedure that employs time history analysis along with compression only elements to simulate staged construction behaviour. This paper presents such a procedure and illustrates it through an example. Keywords: Differential Axial Shortening, Concrete Buildings, Creep and Shrinkage, Construction Sequence, Finite Element Method.

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Two common methods have been used to evaluate the in vitro bioactivity of bioceramics for the application of bone repair. One is to evaluate the ability of apatite formation by soaking ceramics in simulated body fluids (SBF); the other method is to evaluate the effect of ceramics on osteogenic differentiation using cell experiments. Both methods have their own drawbacks in evaluating the in vitro bioactivity of bioceramics. In this commentary paper we review the application of both methods in bioactivity of bioceramics and conclude that (i) SBF method is an efficient method to investigate the in vitro bioactivity of silicate-based bioceramics, (ii) cellular bioactivity of bioceramics should be investigated by evaluating their stimulatory ability using standard bioceramics as controls; and (iii) the combination of these two methods to evaluate the in vitro bioactivity of bioceramics can improve the screening efficiency for the selection of bioactive ceramics for bone regeneration.

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Shrinkage cracking is commonly observed in concrete flat structures such as highway pavements, slabs, and bridge decks. Crack spacing due to shrinkage has received considerable attention for many years [1-3]. However, some aspects concerning the mechanism of crack spacing still remain un-clear. Though it is well known that the interval of the cracks generally falls with a range, no satisfactory explanation has been put forward as to why the minimum spacing exists.

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The evolution of property education to adapt to the changing business environment requires changes to course content, method of delivery and assessment. Many universities have a special interest in understanding how the students transition in and transition out of the property programs. The impact of the first year student experience is often easier to assess through students’ progression in the course and performance in their intermediate and advanced units. However, the students’ success in transitioning from university student to property professional is often more difficult to determine. In an environment where many property students commence their professional careers while still completing their undergraduate property qualification, a survey of current final year students was undertaken to identify the students’ perception of their level of preparedness for entry into the professional world. This study has also been informed by feedback received from and informal discussions held with industry representative bodies, alumni and senior members of professional organisations. The QUT UD40 Bachelor of Urban Development, Property Economics course has been designed to achieve graduate capabilities in core technical skills and generic professional skills which are required by property professionals. The results of this study were that some units in the program were perceived to provide direct preparation for students commencing their professional careers whilst the impact of other units was less tangible. Valuable feedback received during the study included an assessment of the relevance of many multi-disciplinary units, the appropriateness of the programming of units within the course and the appropriateness of repetition of content during the course. The further research question arises as to how universities can better assist students in the transition to the professional environment when frequently this occurs prior to completion of the property course.

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Vocational education and training for the library and information services (LIS) sector in Australia offers students the career pathway to become library technicians. Library technicians play a valuable role in drawing on sound practical knowledge and skills to support the delivery of library and information services that meet client needs. Over the past forty years, the Australian Library and Information Association (ALIA) has monitored the quality of library technician courses. Since 2005, ALIA has run national professional development days for library technician educators with the goal of establishing an alternative model for course recognition focusing on the process of peer review to benchmark good practice and stimulate continuous improvement in library technician education. This initial developmental work has culminated in 2009 with site visits to all library technician courses in Australia. The paper presents a whole-of-industry case study to critically review the work undertaken to date.

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Risk-taking behaviour by motorcyclists has been shown to contribute to a substantial proportion of road crashes in Australia and abroad. Concern has been expressed that traditional motorcycle licence training programs do not sufficiently address such behaviour. Accordingly, the Three Steps to Safer Riding program was developed to address risk taking behaviour by riders as an adjunct to existing skills-based rider training. The program was designed to be delivered in a one hour classroom session at the start of training, with a 20 minute debrief to revise the key concepts at the end of training. This paper reports on the key training concepts, methodology and implementation of the pilot program with a major rider training organisation in Queensland and presents findings from a process evaluation. The Three Steps to Safer Riding intervention pilot was delivered to 518 learner riders over a three month period. Follow-up focus groups and one interview with intervention participants (N=18) five to eight months after completion of the program suggest that new riders (absolute novices) embraced and internalised many of the intervention concepts. However, some riders who had previous riding experience prior to training stated these issues were common sense, yet still expressed riding styles that were contrary to some of the key intervention messages. This is discussed in terms of raising awareness of risk issues for motorcyclists versus behaviour change. Additionally, interviews conducted with riding instructors are discussed regarding logistical challenges of implementation, training consistency, skills required to deliver the program, support for the program, and student engagement.

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The provision of accessible and cost-effective treatment to a large number of problem drinkers is a significant challenge to health services. Previous data suggest that a correspondence intervention may assist in these efforts. We recruited 277 people with alcohol abuse problems and randomly allocated them to immediate cognitive behavioral treatment by correspondence (ICBT), 2 months in a waiting list (WL2-CBT), self-monitoring (SM2-CBT), or extended self-monitoring (SM6-CBT). Everyone received correspondence CBT after the control period. Over 2 months later, no drop in alcohol intake occurred in the waiting list, and CBT had a greater impact than SM. No further gains from SM were seen after 2 months. Effects of CBT were well maintained and were equivalent, whether it was received immediately or after 2 to 6 months of self-monitoring. Weekly alcohol intake fell 48% from pretreatment to 18.6 alcohol units at 12 months. Our results confirmed that correspondence CBT for alcohol abuse was accessible and effective for people with low physical dependence.

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Recognizing the need to offer alternative methods of brief interventions, this study developed correspondence treatments for low-dependent problem drinkers and evaluated their impact. One hundred and twenty-one problem drinkers were recruited by media advertisements and were randomly allocated to a full cognitive behavioural treatment programme (CBT) or to a minimal intervention condition (MI) that gave information regarding alcohol misuse and instructions to record drinking. As predicted, CBT was more effective than MI in reducing alcohol consumption over the 4-month controlled trial period. CBT produced a 50% fall in consumption, bringing the average intake of subjects within recommended maximum levels. Treatment gains at 6 months were well maintained to 12 months. High levels of consumer satisfaction, a high representation of women and a substantial participation from isolated rural areas attested to the feasibility of the correspondence programme as an alternative treatment. However, some drinking occasions still involved high intake for a significant subgroup of subjects, and this issue will be addressed in future programmes. The results supported the use of correspondence delivery as a means of promoting early engagement and equity of access between city and country areas.

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Anecdotal evidence highlights issues of alcohol and other drugs (AODs) and its association with safety risk on construction sites. Information is limited however regarding the prevalence of AODs in the workplace and there is limited evidential guidance regarding how to effectively address it. This research aimed to scientifically evaluate the use of AODs within the Australian construction industry in order to reduce the potential resulting safety and performance impacts and engender a cultural change in the workforce. A national qualitative and quantitative evaluation of the use of AODs was conducted with approximately 500 employees. Results indicate that as in the general population, a proportion of those sampled in the construction sector may be at risk of hazardous alcohol consumption and support the need for evidence-based, tailored responses. This is the first known study to scientifically evaluate the use of AODs and potential workplace safety impacts in the construction sector.