4582 research outputs found
Sort by
Participation in languages education in Australian schools : what do we know, and what does it mean anyway?
No full text
The national human rights consultation committee report: What did it say, and where to from here?
No full textPrice wars and price collusion in China's airline markets
No full textIn the absence of an effective antitrust law, both fare wars and price collusion have been pervasive in China's airline markets, causing concern for both airlines and consumers. A study of monthly airfare data from 2002 to 2004 confirms that fare wars occur periodically, as well as price collusion. Both tend to be short-lived. The fact that collusion is more likely to occur in January and April when demand is high, as revealed by China Eastern's and China Southern's price-war and collusion models, has been confirmed by interview information obtained from the airlines' sales managers. However, there is also evidence in these models suggesting that collusion can be more easily formed when demand is low. High airport concentration measured by the HHI may facilitate collusion in certain circumstances, but it may also lead to more price wars under other conditions. Concentration in both airports and routes does not appear to systematically affect the occurrence of fare wars and collusion in all the models estimated. We also reject the possibility that mutual forbearance due to multimarket contact plays any important anti-competitive role in China's airline markets.
Effect of cyclic stress reversal on cyclic instability behaviour of loose sand-slit mixtures
No full textCyclic liquefaction of soils with a clearly positive state parameter is a form of instability triggered by undrained cyclic loading, where instability is used in the context of continuum mechanics, i.e. a state of dσijdεij < 0. This paper investigates such behaviour in the frame of critical state soil mechanics (CSSM) and taking into account the influence of fines content and cyclic stress reversal. The concept of an equivalent state parameter was used in conjunction with instability stress ratio obtained from monotonic undrained tests to synthesis the cyclic tests results. Experimental results showed that instability stress ratio obtained from monotonic test at the same equivalent state parameter define the triggering of instability under cyclic loading irrespective of stress reversal. The influence of initial effective confining stresses and fines contents can be assessed from the instability stress ratio and the equivalent state parameter.
Evaluation of failure load-deformation characteristics of geo-reinforced soil using simplified approach
No full textIn this research work, a comprehensive testing program has been carried out to study the stress-strain and volume change behavior of unreinforced and reinforced residual soil. A series of drained triaxial tests were conducted using computer controlled GDS triaxial apparatus for unreinforced and reinforced soil. Test results show that reinforced soils exhibit higher failure strains and volume contraction than unreinforced soils. Reinforced soils with non-woven geotextile exhibit higher failure strains, strength and coefficient of interface friction than woven geotextile reinforced residual soil. A simplified approach for numerical calculations were proposed to predict the shear strength of unreinforced and reinforced soils for triaxial compression stress paths and the coefficient of interface friction for reinforced soils. Charts were also presented to predict the strength of reinforced soil and to determine the coefficient of interface friction from triaxial tests. Predictions of failure stress using simplified approach are satisfactory compared to laboratory observations.