Integral terminal sliding mode cooperative control of multi-robot networks

This paper studies the integral terminal sliding mode cooperative control of multi-robot networks. Here, we first propose an integral terminal sliding mode surface for a class of first order systems. Then, we prove that finite time consensus tracking of multi-robot networks can be achieved on this integral terminal sliding mode surface. Simulation results are presented to validate the analysis.

Integral approach and numerical improvement to calculate the carbon concentration profiles in carburising process

In the present work, the carbon diffusion in steel, where the carbon diffusivity varies with the carbon content, was solved with the integral methods under the third boundary condition. The variation of carbon diffusivity in steel with the carbon content was described with two different functions ie. linear dependence and exponential dependence. The integral approximation for both cases was improved with the numerical computation to more accurately predict the carbon profiles. The integral solution is more accurate than the formulation based on the assumption of a constant diffusivity or those based on the assumption of a constant diffusivity and/or constant carbon content at part surface. It is also more easily used in practice than the numerical method to describe the carburising process and predict the carbon content at steel surface and carbon profiles in treated layer.

Experiences of the stolen generation : laws and inequalities

Examines the inequalities of the Aboriginal Australian and politics, government, history, legal status and the effects of Aboriginal institutions in Western Australia. The researcher found that the destruction and disappearance of documents, files and records greatly impacted the thesis.

Maximum-likelihood based estimation for Q-ball imaging using diffusion-weighted MRI data

Q-ball imaging has been presented to reconstruct diffusion orientation distribution function using diffusion weighted MRI. In this thesiis, we present a novel and robust approach to satisfy the smoothness constraint required in Q-ball imaging. Moreover, we developed an improved estimator based on the actual distribution of the MR data.

Assessment of spatiotemporal varying relationships between rainfall, land cover and surface water area using geographically weighted regression

Traditional regression techniques such as ordinary least squares (OLS) are often unable to accurately model spatially varying data and may ignore or hide local variations in model coefficients. A relatively new technique, geographically weighted regression (GWR) has been shown to greatly improve model performance compared to OLS in terms of higher R 2 and lower corrected Akaike information criterion (AICC). GWR models have the potential to improve reliabilities of the identified relationships by reducing spatial autocorrelations and by accounting for local variations and spatial non-stationarity between dependent and independent variables. In this study, GWR was used to examine the relationship between land cover, rainfall and surface water habitat in 149 sub-catchments in a predominately agricultural region covering 2.6 million ha in southeast Australia. The application of the GWR models revealed that the relationships between land cover, rainfall and surface water habitat display significant spatial non-stationarity. GWR showed improvements over analogous OLS models in terms of higher R 2 and lower AICC. The increased explanatory power of GWR was confirmed by the results of an approximate likelihood ratio test, which showed statistically significant improvements over analogous OLS models. The models suggest that the amount of surface water area in the landscape is related to anthropogenic drainage practices enhancing runoff to facilitate intensive agriculture and increased plantation forestry. However, with some key variables not present in our analysis, the strength of this relationship could not be qualified. GWR techniques have the potential to serve as a useful tool for environmental research and management across a broad range of scales for the investigation of spatially varying relationships.

Researching social inequalities in education : towards a Bourdieuian methodology

The injustices of ‘allowing certain people to succeed, based not upon merit but upon the cultural experiences, the social ties and the economic resources they have access to, often remains unacknowledged in the broader society’ (Wacquant, 1998, p. 216). Cognizant of this, the authors argue that education requires researchers’ renewed examination and explanation of its involvement in the construction of social and economic differences. Specifically, they make the case for researchers to consider the theoretical work of Pierre Bourdieu, outlining what they understand by a Bourdieuian methodology, which is informed by socially critical and poststructural understandings of the world. Such methodology attempts to dig beneath surface appearances, asking how social systems work. By asking ‘whose interests are being served and how’ (Tripp, 1998, p. 37) in the social arrangements we find, Bourdieu can help us to ‘work towards a more just social order’ (Lenzo, 1995, p. 17).

Schooling and the production of social inequalities : what can and should we be doing?

To speak of an ideal is to lay claim to what ought or should be and to explain 'reality' as deviation. That is, ideals serve to provide direction towards some desired goal as well as judgment about how well a perceived reality approximates that desire. In more recent times, the postmodernist critique has provided its own 'reality check' on modernist ideals, challenging the notion that there is one best way to reach Utopian ends. The emergence of postmodern theories has signalled a general shift in 'the structure of feeling'1 from acquiescence to censure of the universal. But it is not as if there are no postmodern ideals. In these accounts, utopianism is more cogently understood as 'heterotopianisms'. While we are convinced by such critique, that there are diverse goals of value and pathways to reach them, we admit to some uneasiness about a 'postmodern pluralism' in which ideals have die potential to wash away into relativism, where one ideal is as good as the next and ways of achieving them are also equally regarded.

Automatic grain texture analysis using integral transforms

Tonewood for musical instruments is quarter-sawn and frequently quality-graded based on visual appearance, mechanical and acoustic properties. The assessment uses simple human (subjective) observation, and two ‘‘experts’’ can rate the same sample differently. This paper describes the application of integral transforms (Fourier and Radon) for automatic (objective) assessment of the visual appearance of 10 Sitka spruce (Picea sitchensis) sample images. This work considers surface classification on the basis of grain orientation, count, spacing, and evenness or uniformity.