73 resultados para Nash Bargaining


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Peer review of teaching is recognized increasingly as one strategy for academic development even though historically peer review of teaching is often unsupported by policy, action and culture in many Australian universities. Higher education leaders report that academics generally do not engage with peer review of teaching in a systematic or constructive manner, and this paper advances and analyses a conceptual model to highlight conditions and strategies necessary for the implementation of sustainable peer review in higher education institutions. The model highlights leadership, development and implementation, which are critical to the success and formation of a culture of peer review of teaching. The work arises from collaborative research funded by the Office for Learning and Teaching to foster and advance a culture of peer review of teaching across several universities in Australia.

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Many complex aeronautical design problems can be formulated with efficient multi-objective evolutionary optimization methods and game strategies. This book describes the role of advanced innovative evolution tools in the solution, or the set of solutions of single or multi disciplinary optimization. These tools use the concept of multi-population, asynchronous parallelization and hierarchical topology which allows different models including precise, intermediate and approximate models with each node belonging to the different hierarchical layer handled by a different Evolutionary Algorithm. The efficiency of evolutionary algorithms for both single and multi-objective optimization problems are significantly improved by the coupling of EAs with games and in particular by a new dynamic methodology named “Hybridized Nash-Pareto games”. Multi objective Optimization techniques and robust design problems taking into account uncertainties are introduced and explained in detail. Several applications dealing with civil aircraft and UAV, UCAV systems are implemented numerically and discussed. Applications of increasing optimization complexity are presented as well as two hands-on test cases problems. These examples focus on aeronautical applications and will be useful to the practitioner in the laboratory or in industrial design environments. The evolutionary methods coupled with games presented in this volume can be applied to other areas including surface and marine transport, structures, biomedical engineering, renewable energy and environmental problems.

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The 12.7-10.5 Ma Cougar Point Tuff in southern Idaho, USA, consists of 10 large-volume (>10²-10³ km³ each), high-temperature (800-1000 °C), rhyolitic ash-flow tuffs erupted from the Bruneau-Jarbidge volcanic center of the Yellowstone hotspot. These tuffs provide evidence for compositional and thermal zonation in pre-eruptive rhyolite magma, and suggest the presence of a long-lived reservoir that was tapped by numerous large explosive eruptions. Pyroxene compositions exhibit discrete compositional modes with respect to Fe and Mg that define a linear spectrum punctuated by conspicuous gaps. Airfall glass compositions also cluster into modes, and the presence of multiple modes indicates tapping of different magma volumes during early phases of eruption. Equilibrium assemblages of pigeonite and augite are used to reconstruct compositional and thermal gradients in the pre-eruptive reservoir. The recurrence of identical compositional modes and of mineral pairs equilibrated at high temperatures in successive eruptive units is consistent with the persistence of their respective liquids in the magma reservoir. Recurrence intervals of identical modes range from 0.3 to 0.9 Myr and suggest possible magma residence times of similar duration. Eruption ages, magma temperatures, Nd isotopes, and pyroxene and glass compositions are consistent with a long-lived, dynamically evolving magma reservoir that was chemically and thermally zoned and composed of multiple discrete magma volumes.

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The phase relations have been investigated experimentally at 200 and 500 MPa as a function of water activity for one of the least evolved (Indian Batt Rhyolite) and of a more evolved rhyolite composition (Cougar Point Tuff XV) from the 12·8-8·1 Ma Bruneau-Jarbidge eruptive center of the Yellowstone hotspot. Particular priority was given to accurate determination of the water content of the quenched glasses using infrared spectroscopic techniques. Comparison of the composition of natural and experimentally synthesized phases confirms that high temperatures (>900°C) and extremely low melt water contents (<1·5 wt % H₂O) are required to reproduce the natural mineral assemblages. In melts containing 0·5-1·5 wt % H₂O, the liquidus phase is clinopyroxene (excluding Fe-Ti oxides, which are strongly dependent on fO₂), and the liquidus temperature of the more evolved Cougar Point Tuff sample (BJR; 940-1000°C) is at least 30°C lower than that of the Indian Batt Rhyolite lava sample (IBR2; 970-1030°C). For the composition BJR, the comparison of the compositions of the natural and experimental glasses indicates a pre-eruptive temperature of at least 900°C. The composition of clinopyroxene and pigeonite pairs can be reproduced only for water contents below 1·5 wt % H₂O at 900°C, or lower water contents if the temperature is higher. For the composition IBR2, a minimum temperature of 920°C is necessary to reproduce the main phases at 200 and 500 MPa. At 200 MPa, the pre-eruptive water content of the melt is constrained in the range 0·7-1·3 wt % at 950°C and 0·3-1·0 wt % at 1000°C. At 500 MPa, the pre-eruptive temperatures are slightly higher (by 30-50°C) for the same ranges of water concentration. The experimental results are used to explore possible proxies to constrain the depth of magma storage. The crystallization sequence of tectosilicates is strongly dependent on pressure between 200 and 500 MPa. In addition, the normative Qtz-Ab-Or contents of glasses quenched from melts coexisting with quartz, sanidine and plagioclase depend on pressure and melt water content, assuming that the normative Qtz and Ab/Or content of such melts is mainly dependent on pressure and water activity, respectively. The combination of results from the phase equilibria and from the composition of glasses indicates that the depth of magma storage for the IBR2 and BJR compositions may be in the range 300-400 MPa (13 km) and 200-300 MPa (10 km), respectively.

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The Bruneau-Jarbidge eruptive center (BJEC) in the central Snake River Plain, Idaho, USA consists of the Cougar Point Tuff (CPT), a series of ten, high-temperature (900-1000°C) voluminous ignimbrites produced over the explosive phase of volcanism (12.8-10.5 Ma) and more than a dozen equally high-temperature rhyolite lava flows produced during the effusive phase (10.5-8 Ma). Spot analyses by ion microprobe of oxygen isotope ratios in 210 zircons demonstrate that all of the eruptive units of the BJEC are characterized by zircon δ¹⁸O values ≤ 2.5‰, thus documenting the largest low δ¹⁸O silicic volcanic province known on Earth (>10⁴ km³). There is no evidence for voluminous normal δ¹⁸O magmatism at the BJEC that precedes generation of low δ¹⁸O magmas as there is at other volcanic centers that generate low δ¹⁸O magmas such as Heise and Yellowstone. At these younger volcanic centers of the hotspot track, such low δ¹⁸O magmas represent ~45 % and ~20% respectively of total eruptive volumes. Zircons in all BJEC tuffs and lavas studied (23 units) document strong δ¹⁸O depletion (median CPT δ¹⁸OZrc = 1.0‰, post-CPT lavas = 1.5‰) with the third member of the CPT recording an excursion to minimum δ¹⁸O values (δ¹⁸OZrc= -1.8‰) in a supereruption > 2‰ lower than other voluminous low δ¹⁸O rhyolites known worldwide (δ¹⁸OWR ≤0.9 vs. 3.4‰). Subsequent units of the CPT and lavas record a progressive recovery in δ¹⁸OZrc to ~2.5‰ over a ~ 4 m.y. interval (12 to 8 Ma). We present detailed evidence of unit-to-unit systematic patterns in O isotopic zoning in zircons (i.e. direction and magnitude of Δcore-rim), spectrum of δ¹⁸O in individual units, and zircon inheritance patterns established by re-analysis of spots for U-Th-Pb isotopes by LA-ICPMS and SHRIMP. In conjunction with mineral thermometry and magma compositions, these patterns are difficult to reconcile with the well-established model for "cannibalistic" low δ¹⁸O magma genesis at Heise and Yellowstone. We present an alternative model for the central Snake River Plain using the modeling results of Leeman et al. (2008) for ¹⁸O depletion as a function of depth in a mid-upper crustal protolith that was hydrothermally altered by infiltrating meteoric waters prior to the onset of silicic magmatism. The model proposes that BJEC silicic magmas were generated in response to the propagation of a melting front, driven by the incremental growth of a vast underlying mafic sill complex, over a ~5 m.y. interval through a crustal volume in which a vertically asymmetric δ¹⁸OWR gradient had previously developed that was sharply inflected from ~ -1 to 10‰ at mid-upper crustal depths. Within the context of the model, data from BJEC zircons are consistent with incremental melting and mixing events in roof zones of magma reservoirs that accompany surfaceward advance of the coupled mafic-silicic magmatic system.

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The Bruneau–Jarbidge eruptive center of the central Snake River Plain in southern Idaho, USA produced multiple rhyolite lava flows with volumes of <10 km³ to 200 km³ each from ~11.2 to 8.1 Ma, most of which follow its climactic phase of large-volume explosive volcanism, represented by the Cougar Point Tuff, from 12.7 to 10.5 Ma. These lavas represent the waning stages of silicic volcanism at a major eruptive center of the Yellowstone hotspot track. Here we provide pyroxene compositions and thermometry results from several lavas that demonstrate that the demise of the silicic volcanic system was characterized by sustained, high pre-eruptive magma temperatures (mostly ≥950 °C) prior to the onset of exclusively basaltic volcanism at the eruptive center. Pyroxenes display a variety of textures in single samples, including solitary euhedral crystals as well as glomerocrysts, crystal clots and annealed microgranular inclusions of pyroxene ±magnetite± plagioclase. Pigeonite and augite crystals are unzoned, and there are no detectable differences in major and minor element compositions according to textural variety — mineral compositions in the microgranular inclusions and crystal clots are identical to those of phenocrysts in the host lavas. In contrast to members of the preceding Cougar Point Tuff that host polymodal glass and mineral populations, pyroxene compositions in each of the lavas are characterized by single rather than multiple discrete compositional modes. Collectively, the lavas reproduce and extend the range of Fe–Mg pyroxene compositional modes observed in the Cougar Point Tuff to more Mg-rich varieties. The compositionally homogeneous populations of pyroxene in each of the lavas, as well as the lack of core-to-rim zonation in individual crystals suggest that individual eruptions each were fed by compositionally homogeneous magma reservoirs, and similarities with the Cougar Point Tuff suggest consanguinity of such reservoirs to those that supplied the polymodal Cougar Point Tuff. Pyroxene thermometry results obtained using QUILF equilibria yield pre-eruptive magma temperatures of 905 to 980 °C, and individual modes consistently record higher Ca content and higher temperatures than pyroxenes with equivalent Fe–Mg ratios in the preceding Cougar Point Tuff. As is the case with the Cougar Point Tuff, evidence for up-temperature zonation within single crystals that would be consistent with recycling of sub- or near-solidus material from antecedent magma reservoirs by rapid reheating is extremely rare. Also, the absence of intra-crystal zonation, particularly at crystal rims, is not easily reconciled with cannibalization of caldera fill that subsided into pre-eruptive reservoirs. The textural, compositional and thermometric results rather are consistent with minor re-equilibration to higher temperatures of the unerupted crystalline residue from the explosive phase of volcanism, or perhaps with newly generated magmas from source materials very similar to those for the Cougar Point Tuff. Collectively, the data suggest that most of the pyroxene compositional diversity that is represented by the tuffs and lavas was produced early in the history of the eruptive center and that compositions across this range were preserved or duplicated through much of its lifetime. Mineral compositions and thermometry of the multiple lavas suggest that unerupted magmas residual to the explosive phase of volcanism may have been stored at sustained, high temperatures subsequent to the explosive phase of volcanism. If so, such persistent high temperatures and large eruptive magma volumes likewise require an abundant and persistent supply of basalt magmas to the lower and/or mid-crust, consistent with the tectonic setting of a continental hotspot.

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Supermarkets in Australia may have substantial market power as buyers in wholesale markets for grocery products. They may also have substantial bargaining power in negotiating contracts with their suppliers of grocery products. The Competition and Consumer Act 2010 (Cth) (CCA) regulates misconduct by supermarkets as customer/acquirers in three ways. First, s 46(1) of the CCA prohibits the ‘taking advantage’ of buyer power for the purpose of damaging a competitor, preventing entry or deterring or preventing competitive conduct. Secondly, s 21 of the ACL prohibits unconscionable conduct in business–to–business transactions. Thirdly, Pt IVB of the CCA provides for the promulgation of mandatory and voluntary industry codes of conduct. Since 1 July 2015 the conduct of supermarkets as customer/acquirers has been regulated by the Food and Grocery Industry Code of Conduct. This article examines these three different approaches. It considers them against the background of the misconduct at issue in ACCC v Coles Supermarkets Australia Pty Ltd which the ACCC chose to litigate as an unconscionable conduct case, rather than a misuse of market power case. The article also considers the strengths and weaknesses of each of the three approaches and concludes that while the three approaches address different problems there is scope for overlap and all three should be retained for compete coverage.

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Background The Global Burden of Disease, Injuries, and Risk Factor study 2013 (GBD 2013) is the first of a series of annual updates of the GBD. Risk factor quantification, particularly of modifiable risk factors, can help to identify emerging threats to population health and opportunities for prevention. The GBD 2013 provides a timely opportunity to update the comparative risk assessment with new data for exposure, relative risks, and evidence on the appropriate counterfactual risk distribution. Methods Attributable deaths, years of life lost, years lived with disability, and disability-adjusted life-years (DALYs) have been estimated for 79 risks or clusters of risks using the GBD 2010 methods. Risk–outcome pairs meeting explicit evidence criteria were assessed for 188 countries for the period 1990–2013 by age and sex using three inputs: risk exposure, relative risks, and the theoretical minimum risk exposure level (TMREL). Risks are organised into a hierarchy with blocks of behavioural, environmental and occupational, and metabolic risks at the first level of the hierarchy. The next level in the hierarchy includes nine clusters of related risks and two individual risks, with more detail provided at levels 3 and 4 of the hierarchy. Compared with GBD 2010, six new risk factors have been added: handwashing practices, occupational exposure to trichloroethylene, childhood wasting, childhood stunting, unsafe sex, and low glomerular filtration rate. For most risks, data for exposure were synthesised with a Bayesian meta-regression method, DisMod-MR 2.0, or spatial-temporal Gaussian process regression. Relative risks were based on meta-regressions of published cohort and intervention studies. Attributable burden for clusters of risks and all risks combined took into account evidence on the mediation of some risks such as high body-mass index (BMI) through other risks such as high systolic blood pressure and high cholesterol. Findings All risks combined account for 57·2% (95% uncertainty interval [UI] 55·8–58·5) of deaths and 41·6% (40·1–43·0) of DALYs. Risks quantified account for 87·9% (86·5–89·3) of cardiovascular disease DALYs, ranging to a low of 0% for neonatal disorders and neglected tropical diseases and malaria. In terms of global DALYs in 2013, six risks or clusters of risks each caused more than 5% of DALYs: dietary risks accounting for 11·3 million deaths and 241·4 million DALYs, high systolic blood pressure for 10·4 million deaths and 208·1 million DALYs, child and maternal malnutrition for 1·7 million deaths and 176·9 million DALYs, tobacco smoke for 6·1 million deaths and 143·5 million DALYs, air pollution for 5·5 million deaths and 141·5 million DALYs, and high BMI for 4·4 million deaths and 134·0 million DALYs. Risk factor patterns vary across regions and countries and with time. In sub-Saharan Africa, the leading risk factors are child and maternal malnutrition, unsafe sex, and unsafe water, sanitation, and handwashing. In women, in nearly all countries in the Americas, north Africa, and the Middle East, and in many other high-income countries, high BMI is the leading risk factor, with high systolic blood pressure as the leading risk in most of Central and Eastern Europe and south and east Asia. For men, high systolic blood pressure or tobacco use are the leading risks in nearly all high-income countries, in north Africa and the Middle East, Europe, and Asia. For men and women, unsafe sex is the leading risk in a corridor from Kenya to South Africa. Interpretation Behavioural, environmental and occupational, and metabolic risks can explain half of global mortality and more than one-third of global DALYs providing many opportunities for prevention. Of the larger risks, the attributable burden of high BMI has increased in the past 23 years. In view of the prominence of behavioural risk factors, behavioural and social science research on interventions for these risks should be strengthened. Many prevention and primary care policy options are available now to act on key risks.

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This paper presents a maximum likelihood method for estimating growth parameters for an aquatic species that incorporates growth covariates, and takes into consideration multiple tag-recapture data. Individual variability in asymptotic length, age-at-tagging, and measurement error are also considered in the model structure. Using distribution theory, the log-likelihood function is derived under a generalised framework for the von Bertalanffy and Gompertz growth models. Due to the generality of the derivation, covariate effects can be included for both models with seasonality and tagging effects investigated. Method robustness is established via comparison with the Fabens, improved Fabens, James and a non-linear mixed-effects growth models, with the maximum likelihood method performing the best. The method is illustrated further with an application to blacklip abalone (Haliotis rubra) for which a strong growth-retarding tagging effect that persisted for several months was detected

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We consider the development of statistical models for prediction of constituent concentration of riverine pollutants, which is a key step in load estimation from frequent flow rate data and less frequently collected concentration data. We consider how to capture the impacts of past flow patterns via the average discounted flow (ADF) which discounts the past flux based on the time lapsed - more recent fluxes are given more weight. However, the effectiveness of ADF depends critically on the choice of the discount factor which reflects the unknown environmental cumulating process of the concentration compounds. We propose to choose the discount factor by maximizing the adjusted R-2 values or the Nash-Sutcliffe model efficiency coefficient. The R2 values are also adjusted to take account of the number of parameters in the model fit. The resulting optimal discount factor can be interpreted as a measure of constituent exhaustion rate during flood events. To evaluate the performance of the proposed regression estimators, we examine two different sampling scenarios by resampling fortnightly and opportunistically from two real daily datasets, which come from two United States Geological Survey (USGS) gaging stations located in Des Plaines River and Illinois River basin. The generalized rating-curve approach produces biased estimates of the total sediment loads by -30% to 83%, whereas the new approaches produce relatively much lower biases, ranging from -24% to 35%. This substantial improvement in the estimates of the total load is due to the fact that predictability of concentration is greatly improved by the additional predictors.

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It is now widely acknowledged that student mental well-being is a critical factor in the tertiary student learning experience and is important to student learning success. The issue of student mental well-being also has implications for effective student transition out of university and into the world of work. It is therefore vital that intentional strategies are adopted by universities both within the formal curriculum, and outside it, to promote student well-being and to work proactively and preventatively to avoid a decline in student psychological well-being. This paper describes how the Queensland University of Technology Law School is using animation to teach students about the importance for their learning success of the protection of their mental well-being. Mayer and Moreno (2002) define an animation as an external representation with three main characteristics: (1) it is a pictorial representation, (2) it depicts apparent movement, and (3) it consists of objects that are artificially created through drawing or some other modelling technique. Research into the effectiveness of animation as a tool for tertiary student learning engagement is relatively new and growing field of enquiry. Nash argues, for example, that animations provide a “rich, immersive environment [that] encourages action and interactivity, which overcome an often dehumanizing learning management system approach” (Nash, 2009, 25). Nicholas states that contemporary millennial students in universities today, have been immersed in animated multimedia since their birth and in fact need multimedia to learn and communicate effectively (2008). However, it has also been established, for example through the work of Lowe (2003, 2004, 2008) that animations can place additional perceptual, attentional, and cognitive demands on students that they are not always equipped to cope with. There are many different genres of animation. The dominant style of animation used in the university learning environment is expository animation. This approach is a useful tool for visualising dynamic processes and is used to support student understanding of subjects and themes that might otherwise be perceived as theoretically difficult and disengaging. It is also a form of animation that can be constructed to avoid any potential negative impact on cognitive load that the animated genre might have. However, the nature of expository animation has limitations for engaging students, and can present as clinical and static. For this reason, the project applied Kombartzky, Ploetzner, Schlag, and Metz’s (2010) cognitive strategy for effective student learning from expository animation, and developed a hybrid form of animation that takes advantage of the best elements of expository animation techniques along with more engaging short narrative techniques. First, the paper examines the existing literature on the use of animation in tertiary educational contexts. Second, the paper describes how animation was used at QUT Law School to teach students about the issue of mental well-being and its importance to their learning success. Finally, the paper analyses the potential of the use of animation, and of the cognitive strategy and animation approach trialled in the project, as a teaching tool for the promotion of student learning about the importance of mental well-being.

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This paper investigates the optimal choice of foreign aid when trade policies are decided in a non-cooperative fashion. Three alternative scenarios, depending on the timing of the actions and on whether aid is tied, are analyzed. It is shown that, in the case where aid is decided before tariffs, untied aid can lead to the reduction of the recipient's optimal trade tax. When the donor can tie the aid to a reduction in the recipient's tariff, the optimal aid level is always positive and the world can always achieve a Pareto-efficient equilibrium.