259 resultados para Inequality constraint


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Most urban dwelling Australians take secure and safe water supplies for granted. That is, they have an adequate quantity of water at a quality that can be used by people without harm from human and animal wastes, salinity and hardness or pollutants from agriculture and manufacturing industries. Australia wide urban and peri-urban dwellers use safe water for all domestic as well as industrial purposes. However, this is not the situation remote regions in Australia where availability and poor quality water can be a development constraint. Nor is it the case in Sri Lanka where people in rural regions are struggling to obtain a secure supply of water, irrespective of it being safe because of the impact of faecal and other contaminants. The purposes of this paper are to overview: the population and environmental health challenges arising from the lack of safe water in rural and remote communities; response pathways to address water quality issues; and the status of and need for integrated catchment management (ICM) in selected remote regions of Australia and vulnerable and lagging rural regions in Sri Lanka. Conclusions are drawn that focus on the opportunity for inter-regional collaborations between Australia and Sri Lanka for the delivery of safe water through ICM.

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In this paper, we propose a framework for joint allocation and constrained control design of flight controllers for Unmanned Aircraft Systems (UAS). The actuator configuration is used to map actuator constraint set into the space of the aircraft generalised forces. By constraining the demanded generalised forces, we ensure that the allocation problem is always feasible; and therefore, it can be solved without constraints. This leads to an allocation problem that does not require on-line numerical optimisation. Furthermore, since the controller handles the constraints, and there is no need to implement heuristics to inform the controller about actuator saturation. The latter is fundamental for avoiding Pilot Induced Oscillations (PIO) in remotely operated UAS due to the rate limit on the aircraft control surfaces.

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Introduction Given the known challenges of obtaining accurate measurements of small radiation fields, and the increasing use of small field segments in IMRT beams, this study examined the possible effects of referencing inaccurate field output factors in the planning of IMRT treatments. Methods This study used the Brainlab iPlan treatment planning system to devise IMRT treatment plans for delivery using the Brainlab m3 microMLC (Brainlab, Feldkirchen, Germany). Four pairs of sample IMRT treatments were planned using volumes, beams and prescriptions that were based on a set of test plans described in AAPM TG 119’s recommendations for the commissioning of IMRT treatment planning systems [1]: • C1, a set of three 4 cm volumes with different prescription doses, was modified to reduce the size of the PTV to 2 cm across and to include an OAR dose constraint for one of the other volumes. • C2, a prostate treatment, was planned as described by the TG 119 report [1]. • C3, a head-and-neck treatment with a PTV larger than 10 cm across, was excluded from the study. • C4, an 8 cm long C-shaped PTV surrounding a cylindrical OAR, was planned as described in the TG 119 report [1] and then replanned with the length of the PTV reduced to 4 cm. Both plans in each pair used the same beam angles, collimator angles, dose reference points, prescriptions and constraints. However, one of each pair of plans had its beam modulation optimisation and dose calculation completed with reference to existing iPlan beam data and the other had its beam modulation optimisation and dose calculation completed with reference to revised beam data. The beam data revisions consisted of increasing the field output factor for a 0.6 9 0.6 cm2 field by 17 % and increasing the field output factor for a 1.2 9 1.2 cm2 field by 3 %. Results The use of different beam data resulted in different optimisation results with different microMLC apertures and segment weightings between the two plans for each treatment, which led to large differences (up to 30 % with an average of 5 %) between reference point doses in each pair of plans. These point dose differences are more indicative of the modulation of the plans than of any clinically relevant changes to the overall PTV or OAR doses. By contrast, the maximum, minimum and mean doses to the PTVs and OARs were smaller (less than 1 %, for all beams in three out of four pairs of treatment plans) but are more clinically important. Of the four test cases, only the shortened (4 cm) version of TG 119’s C4 plan showed substantial differences between the overall doses calculated in the volumes of interest using the different sets of beam data and thereby suggested that treatment doses could be affected by changes to small field output factors. An analysis of the complexity of this pair of plans, using Crowe et al.’s TADA code [2], indicated that iPlan’s optimiser had produced IMRT segments comprised of larger numbers of small microMLC leaf separations than in the other three test cases. Conclusion: The use of altered small field output factors can result in substantially altered doses when large numbers of small leaf apertures are used to modulate the beams, even when treating relatively large volumes.

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The effects of crack depth (a/W) and specimen width W on the fracture toughness and ductile±brittle transition have been investigated using three-point bend specimens. Finite element analysis is employed to obtain the stress-strain fields ahead of the crack tip. The results show that both normalized crack depth (a/W) and specimen width (W) affect the fracture toughness and ductile±brittle fracture transition. The measured crack tip opening displacement decreases and ductile±brittle transition occurs with increasing crack depth (a/W) from 0.1 to 0.2 and 0.3. At a fixed a/W (0.2 or 0.3), all specimens fail by cleavage prior to ductile tearing when specimen width W increases from 25 to 40 and 50 mm. The lower bound fracture toughness is not sensitive to crack depth and specimen width. Finite element analysis shows that the opening stress in the remaining ligament is elevated with increasing crack depth or specimen width due to the increase of in-plane constraint. The average local cleavage stress is dependent on both crack depth and specimen width but its lower bound value is not sensitive to constraint level. No fixed distance can be found from the cleavage initiation site to the crack tip and this distance increases gradually with decreasing inplane constraint.

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This paper presents a framework for the design of a joint motion controller and a control allocation strategy for dynamic positioning of marine vehicles. The key aspects of the proposed designs are a systematic approach to deal with actuator saturation and to inform the motion controller about saturation. The proposed system uses a mapping that translates the actuator constraint sets into constraint sets at the motion controller level. Hence, while the motion controller addresses the constraints, the control allocation algorithm can solve an unconstrained optimisation problem. The constrained control design is approached using a multivariable anti-wind-up strategy for strictly proper controllers. This is applicable to the implementation of PI and PID type of motion controllers.

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Large deformation finite element analysis has been carried out to investigate the stress-strain fields ahead of a growing crack for compact tension .a=W D 0:5/ and three-point bend .a=W D 0:1 and 0:5/ specimens under plane stress condition. The crack growth is controlled by the experimental J -integral resistance curves measured by Sun et al. The results indicate that the distributions of opening stress, equivalent stress and equivalent strain ahead of a growing crack are not sensitive to specimen geometry. For both stationary and growing cracks, similar distributions of opening stress and triaxiality can be found along the ligament. During stable crack growth, the crack-tip opening displacement (CTOD) resistance curve and the cohesive fracture energy in the fracture process zone are independent of specimen geometry and may be suitable criteria for characterizing stable crack growth in plane stress.

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A measure quantifying unequal use of carbon sources, the Gini coefficient (G), has been developed to allow comparisons of the observed functional diversity of bacterial soil communities. This approach was applied to the analysis of substrate utilisation data obtained from using BIOLOG microtiter plates in a study which compared decomposition processes in two contrasting plant substrates in two different soils. The relevance of applying the Gini coefficient as a measure of observed functional diversity, for soil bacterial communities is evaluated against the Shannon index (H) and average well colour development (AWCD), a measure of the total microbial activity. Correlation analysis and analysis of variance of the experimental data show that the Gini coefficient, the Shannon index and AWCD provided similar information when used in isolation. However, analyses based on the Gini coefficient and the Shannon index, when total activity on the microtiter plates was maintained constant (i.e. AWCD as a covariate), indicate that additional information about the distribution of carbon sources being utilised can be obtained. We demonstrate that the Lorenz curve and its measure of inequality, the Gini coefficient, provides not only comparable information to AWCD and the Shannon index but when used together with AWCD encompasses measures of total microbial activity and absorbance inequality across all the carbon sources. This information is especially relevant for comparing the observed functional diversity of soil microbial communities.

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As the end of the Cold War approached in 1989, Caroline Thomas argued: “It is important that the discipline [International Relations, IR] should address the issue of disease and more broadly, health, not simply to facilitate containment of disease transmission across international borders but also because central notions of justice, equity, efficiency and order are involved” (1989:273).1 Ten years later, Craig Murphy echoed these sentiments. Murphy (2001: 352) proposed that IR had yet to grapple with the political consequences of growing inequality between the world’s rich and poor, and areas such as health—where these inequalities were most stark—should become the field’s core business. How IR’s theories and methods would approach these issues was less clear. Bettcher and Yach (1998) cautioned that IR would be unable to develop progressive research projects that explored global health diplomacy as a global public good without adopting new perspectives and methods. Others warned that the expansion of security studies into areas such as global health would weaken the intellectual coherency of the field (Walt 1991:213). Taking its cue from the recent Ng and Prah Ruger (2011) study, this paper returns to these concerns to briefly explore key trends and potential future concerns of research in IR on health...

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Public engagement is an essential process for major municipal infrastructure and construction projects as it serves to identify the interests and concerns of citizens before the planning and design are finalised and thus ensures the schemes are beneficial to all sectors of the community. However, the success of public engagement depends on a number of factors, not least the suitability of the engagement methods used, representativeness and activeness of participants, time pressure, financial constraint and so on. In Hong Kong, the community has experienced discontent with several major projects recently, suggesting the need to examine the effectiveness of its current public engagement mechanism. This paper reports the results of a series of interviews with a variety of stakeholders – indicating the need for a carefully considered public engagement plan to be established at the beginning to drive the process and more experienced people to lead and facilitate the engagement process.

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A combined experimental and numerical program was conducted to study the in-plane shear behaviour of hollow concrete masonry panels containing reinforced grout cores. This paper is focused on the numerical program. A two dimensional macromodelling strategy was used to simulate the behaviour of the confined masonry (CM) shear panels. Both the unreinforced masonry and the confining element were modelled using macromasonry properties and the steel reinforcement was modelled as an embedded truss element located within the grout using perfectly bonded constraint. The FE model reproduced key behaviours observed in the experiments, including the shear strength, the deformation and the crack patterns of the unconfined and confined masonry panels. The predictions of the validated model were used to evaluate the existing in-plane shear expressions available in the national masonry standards and research publications.

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INTRODUCTION Managing spinal deformities in young children is challenging, particularly early onset scoliosis (EOS). Surgical intervention is often required if EOS has been unresponsive to conservative treatment particularly with rapidly progressive curves. An emerging treatment option for EOS is fusionless scoliosis surgery. Similar to bracing, this surgical option potentially harnesses growth, motion and function of the spine along with correcting spinal deformity. Dual growing rods are one such fusionless treatment, which aims to modulate growth of the vertebrae. The aim of this study was to ascertain the extent to which semiconstrained growing rods (Medtronic, Sofamor, Danek, Memphis, TN) with a telescopic sleeve component, reduce rotational constraint on the spine compared with standard "constrained / rigid" rods and hence potentially provide a more physiological mechanical environment for the growing spine. METHODS Six 40-60kg English Large White porcine spines served as a model for the paediatric human spine. Each spine was dissected into a 7 level thoracolumbar multi-segment unit (MSU), removing all non-ligamentous soft tissues and leaving 3cm of ribs either side. Pure nondestructive axial rotation moments of ±4Nm at a constant rotation rate of 8deg.s-1 were applied to the mounted MSU spines using a biaxial Instron testing machine. Displacement of each vertebral level was captured using a 3D motion tracking system (Optotrak 3020, Northern Digital Inc, Waterloo, ON). Each spine was tested in an un-instrumented state first and then with appropriately sized semi-constrained growing rods and rigid rods in alternating sequence. The rods were secured by multi-axial pedicle screws (Medtronic CD Horizon) at levels 2 and 6 of the construct. The range of motion (ROM), neutral zone (NZ) size and stiffness (Nm.deg-1) were calculated from the Instron load-displacement data and intervertebral ROM was calculated through a MATLAB algorithm from Optotrak data. RESULTS Irrespective of the order of testing, rigid rods significantly reduced the total ROM compared with semi-constrained rods (p<0.05) with in a significantly stiffer spine for both left and right axial rotation (p<0.05). Analysing the intervertebral motion within the instrumented levels 2-6, rigid rods showed reduced ROM compared with semi-constrained growing rods and compared with un-instrumented motion segments. CONCLUSION Semi-constrained growing rods maintain similar stiffness in axial rotation to un-instrumented spines, while dual rigid rods significantly reduce axial rotation. Clinically the effect of semi-constrained growing rods as observed in this study is that they would be expected to allow growth via the telescopic rod components while maintaining the axial flexibility of the spine, which may reduce occurrence of the crankshaft phenomenon.

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Two of the three cross-curriculum priorities for the national Australian Curriculum prescribed by the Australian Curriculum Assessment and Reporting Authority (ACARA) are focussed on what might be called diversity education: “Aboriginal and Torres Strait Islander histories and culture”, and "Asia and Australia's Engagement with Asia” (ACARA, “Cross”). One need not be versed in complex rhetorical theory to understand that, laudable and legitimate as such priorities are, their existence implies that mainstream education in Australia has been or is characterised by the marginalisation or erasure of Australia's history—the original Indigenous cultures are not only living and vibrant today, but also have tens of thousands of years’ “head start” on Australia’s settler cultures—and of its geography—Australia is, after all, located in some physical proximity to Asia. Some might even suggest that Australia is in Asia. These temporal and spatial “forgettings” constitute a kind of cultural perversity which the cross-curricular priorities both seek to address and serve to reinscribe. Even as ACARA requires Australian school students to engage with Aboriginal and Asian histories, cultures, societies, they imply that such histories, cultures, and societies are “diverse”, that they are not those of the students in Australian classrooms; producing them as objects of study rather than as lived experience. This should not necessarily be surprising. Michael W. Apple has provocatively argued that: “one of the perverse effects of a national curriculum actually will be to ‘legitimise inequality.’ It may in fact help create the illusion that whatever the massive differences in schools, they all have something in common” (18). In the Australian context, attempts to mitigate such perversity are articulated via the selection of literary texts. As educators move to resource ACARA’s cross-curricular priorities, ACARA notes that “Teachers and schools are best placed to make decisions about the selection of texts in their teaching and learning programs that address the content in the Australian Curriculum while also meeting the needs of the students in their classes” (ACARA, “Advice”). This assertion appears on a webpage called “Advice on selection of literary texts” which is notable first and foremost for its total lack of any literary texts being named, and its list of weblinks pointing to lists of texts compiled elsewhere, by other organisations, and in the main, compiled to serve agendas other than the Australian curriculum. One of the major resources referred to by ACARA for literary text selection is the Children’s Book Council of Australia (CBCA). Of course, the CBCA’s annual book awards do not share ACARA’s educational priorities, but do have a history of being drawn upon by schools as a curriculum resource. In this paper, I consider the literary texts which have been prized by the CBCA in recent years attending to their engagements with Aboriginal cultures.

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The quick detection of an abrupt unknown change in the conditional distribution of a dependent stochastic process has numerous applications. In this paper, we pose a minimax robust quickest change detection problem for cases where there is uncertainty about the post-change conditional distribution. Our minimax robust formulation is based on the popular Lorden criteria of optimal quickest change detection. Under a condition on the set of possible post-change distributions, we show that the widely known cumulative sum (CUSUM) rule is asymptotically minimax robust under our Lorden minimax robust formulation as a false alarm constraint becomes more strict. We also establish general asymptotic bounds on the detection delay of misspecified CUSUM rules (i.e. CUSUM rules that are designed with post- change distributions that differ from those of the observed sequence). We exploit these bounds to compare the delay performance of asymptotically minimax robust, asymptotically optimal, and other misspecified CUSUM rules. In simulation examples, we illustrate that asymptotically minimax robust CUSUM rules can provide better detection delay performance at greatly reduced computation effort compared to competing generalised likelihood ratio procedures.

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INTRODUCTION Managing spinal deformities in young children is challenging, particularly early-onset scoliosis (EOS). Any progressive spinal deformity particularly in early life presents significant health risks for the child and a challenge for the treating surgeon. Surgical intervention is often required if EOS has been unresponsive to conservative treatment particularly with rapidly progressive curves. An emerging treatment option particularly for EOS is fusionless scoliosis surgery. Similar to bracing this surgical option potentially harnesses growth, motion and function of the spine along with correcting spinal deformity. Dual growing rods is one such fusionless treatment, which aims to modulate growth of the vertebrae. The aim of this study was to ascertain the extent to which semi-constrained growing rods (Medtronic, Memphis, TN) with a telescopic sleeve component, reduce rotational constraint on the spine compared with standard rigid rods and hence potentially provide a more physiological mechanical environment for the growing spine. METHODS Six 40-60kg English Large White porcine spines served as a model for the paediatric human spine. Each spine was dissected into 7 level thoracolumbar multi-segment unit (MSU) spines, removing all non-ligamentous soft tissues. Appropriately sized semi-constrained growing rods and rigid rods were secured by multi-axial screws (Medtronic) prior to testing in alternating sequences for each spine. Pure nondestructive moments of +/4Nm at a constant rotation rate of 8deg/s was applied to the mounted MSU spines. Displacement of each level was captured using an Optotrak (Northern Digital Inc, Waterloo, ON). The range of motion (ROM), neutral zone (NZ) size and stiffness (Nm/deg) were calculated from the Instron load-displacement data and intervertebral ROM was calculated through a MATLAB algorithm from Optotrak data. RESULTS Irrespective of sequence order rigid rods significantly reduced the total ROM (deg) than compared to semi-constrained rods (p<0.05) and resulted in a significantly stiffer (Nm/deg) spine for both left and right axial rotation testing (p<0.05). Analysing the intervertebral motion within the instrumented levels, rigid rods showed reduced ROM (Deg) than compared to semi-constrained growing rods and the un-instrumented (UN-IN) test sequences. CONCLUSION The semi-constrained growing rods maintained rotation similar to UN-IN spines while the rigid rods showed significantly reduced axial rotation across all instrumented levels. Clinically the effect of semi-constrained growing rods evaluated in this study is that they will allow growth via the telescopic rod components while maintaining the axial rotation ability of the spine, which may also reduce the occurrence of the crankshaft phenomenon.

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Occupational segregation is a major source of labour market rigidity and economic inefficiency due to a waste of human resources. Organisations are repeatedly recognised as gendered constructs exhibiting sustained work segregation, income and status inequality, as well as cultural and individual images of gender, and these are perpetuated through their processes, practices and pressures (Acker, 1990). A large percentage of Australia’s workforce is now employed in project-based or project-oriented organisations, leading to the claim that Australia is a project-based economy. For a continued strong performance in this economy, organisations that employ project personnel will need to consider how they address inclusivity and equality in diversity in project based temporary organisations to ensure the supply of high quality project professionals into the future. This paper investigates the inclusion processes experienced and exercised by men and women working in temporary organisations in project situations through a review of reports on the inclusion processes experienced by 60 project managers and project workers in three project based industries in Australia. Results indicate that temporary organisations are not implementing equality and diversity management strategies at the macro level and project workers are accepting this lack of recognition. However inclusivity and equality at the micro level of the team is seen as vital.