Spatio-temporal learning with the online finite and infinite echo-state Gaussian processes

Successful biological systems adapt to change. In this paper, we are principally concerned with adaptive systems that operate in environments where data arrives sequentially and is multivariate in nature, for example, sensory streams in robotic systems. We contribute two reservoir inspired methods: 1) the online echostate Gaussian process (OESGP) and 2) its infinite variant, the online infinite echostate Gaussian process (OIESGP) Both algorithms are iterative fixed-budget methods that learn from noisy time series. In particular, the OESGP combines the echo-state network with Bayesian online learning for Gaussian processes. Extending this to infinite reservoirs yields the OIESGP, which uses a novel recursive kernel with automatic relevance determination that enables spatial and temporal feature weighting. When fused with stochastic natural gradient descent, the kernel hyperparameters are iteratively adapted to better model the target system. Furthermore, insights into the underlying system can be gleamed from inspection of the resulting hyperparameters. Experiments on noisy benchmark problems (one-step prediction and system identification) demonstrate that our methods yield high accuracies relative to state-of-the-art methods, and standard kernels with sliding windows, particularly on problems with irrelevant dimensions. In addition, we describe two case studies in robotic learning-by-demonstration involving the Nao humanoid robot and the Assistive Robot Transport for Youngsters (ARTY) smart wheelchair

Iterative Temporal Learning and Prediction with the Sparse Online Echo State Gaussian Process

Abstract—In this work, we contribute the online echo state gaussian process (OESGP), a novel Bayesian-based online method that is capable of iteratively learning complex temporal dy-namics and producing predictive distributions (instead of point predictions). Our method can be seen as a combination of the echo state network with a sparse approximation of Gaussian processes (GPs). Extensive experiments on the one-step prediction task on well-known benchmark problems show that OESGP produced statistically superior results to current online ESNs and state-of-the-art regression methods. In addition, we characterise the benefits (and drawbacks) associated with the considered online methods, specifically with regards to the trade-off between computational cost and accuracy. For a high-dimensional action recognition task, we demonstrate that OESGP produces high accuracies comparable to a recently published graphical model, while being fast enough for real-time interactive scenarios. I

Towards Early Mobility Independence: An Intelligent Paediatric Wheelchair with Case Studies

Standard powered wheelchairs are still heavily dependent on the cognitive capabilities of users. Unfortunately, this excludes disabled users who lack the required problem-solving and spatial skills, particularly young children. For these children to be denied powered mobility is a crucial set-back; exploration is important for their cognitive, emotional and psychosocial development. In this paper, we present a safer paediatric wheelchair: the Assistive Robot Transport for Youngsters (ARTY). The fundamental goal of this research is to provide a key-enabling technology to young children who would otherwise be unable to navigate independently in their environment. In addition to the technical details of our smart wheelchair, we present user-trials with able-bodied individuals as well as one 5-year-old child with special needs. ARTY promises to provide young children with early access to the path towards mobility independence

How Different are Universities from Companies? Financial Reporting Perspectives and the Market for Vice Chancellors (Part 2)

The oldest university still in operation is approximately 1,750 years old (wordiQ.com, 2004). When compared to firms, universities have stood the test of time, while firms seem to lack longevity. The oldest listed firm still operating is around 225 years old (O’Hara and Mandel, 2004), a lifespan of approximately one-eighth that of the oldest university. Whilst this comparison involves extremes, it is still the case that the average university is much older than the average company. What distinctive features of universities promote their long lifespans? Summers (2003) argues that it is the importance placed on knowledge and ideas in universities that help them withstand the test of time. He goes further to suggest that corporations may do better in meeting their challenges if they adopt some of the features of the university model. However, over time, we have seen universities moving away from their traditional positions as nonprofit organisations to institutions that are concerned with their financial viability. To what extent are universities becoming transformed into corporations? There is evidence suggesting that earnings quality for universities has improved over time, consistent with the theory that universities face increased pressure to become more like corporates and for greater public accountability as they seek to raise revenue from non-traditional sources in the face of federal funding cuts to higher education. We look at two dimensions of earnings quality for Australian universities: one based on the adherence of financial statements to prescribed requirements and the second based on accruals and earnings persistence. Although universities are nominally nonprofit organisations, there is evidence that they behave like companies and have incentives to avoid reporting negative earnings results. However, there is little evidence of opportunistic accruals earnings management. How does leadership affect the dynamics of these organisations? We investigate this by looking at the workings of the market for Vice-Chancellors. A picture of the typical Vice-Chancellor emerges. We see that they are appointed at relatively older ages than CEOs in the private sector, although they do not have shorter tenure. On an international comparison between Vice-Chancellors, Australian Vice-Chancellors enjoy the highest real remuneration, favourable taxation arrangements and a better quality of life relative to their counterparts in the United States and the United Kingdom. There is also a large disparity between the remuneration of Vice-Chancellors and CEOs, with the discount associated with university top management positions at 60 percent relative to the private sector. The evidence suggests that on the spectrum of organisation type from nonprofits to corporates, the traditional way in which we view universities as predominantly nonprofits is not consistent with the underlying behaviour of these institutions. This raises interesting implications for the future of higher education in Australia and the quality of the public good provided.

How Different are Universities from Companies? Financial Reporting Perspectives and the Market for Vice Chancellors (Part 4)

The oldest university still in operation is approximately 1,750 years old (wordiQ.com, 2004). When compared to firms, universities have stood the test of time, while firms seem to lack longevity. The oldest listed firm still operating is around 225 years old (O’Hara and Mandel, 2004), a lifespan of approximately one-eighth that of the oldest university. Whilst this comparison involves extremes, it is still the case that the average university is much older than the average company. What distinctive features of universities promote their long lifespans? Summers (2003) argues that it is the importance placed on knowledge and ideas in universities that help them withstand the test of time. He goes further to suggest that corporations may do better in meeting their challenges if they adopt some of the features of the university model. However, over time, we have seen universities moving away from their traditional positions as nonprofit organisations to institutions that are concerned with their financial viability. To what extent are universities becoming transformed into corporations? There is evidence suggesting that earnings quality for universities has improved over time, consistent with the theory that universities face increased pressure to become more like corporates and for greater public accountability as they seek to raise revenue from non-traditional sources in the face of federal funding cuts to higher education. We look at two dimensions of earnings quality for Australian universities: one based on the adherence of financial statements to prescribed requirements and the second based on accruals and earnings persistence. Although universities are nominally nonprofit organisations, there is evidence that they behave like companies and have incentives to avoid reporting negative earnings results. However, there is little evidence of opportunistic accruals earnings management. How does leadership affect the dynamics of these organisations? We investigate this by looking at the workings of the market for Vice-Chancellors. A picture of the typical Vice-Chancellor emerges. We see that they are appointed at relatively older ages than CEOs in the private sector, although they do not have shorter tenure. On an international comparison between Vice-Chancellors, Australian Vice-Chancellors enjoy the highest real remuneration, favourable taxation arrangements and a better quality of life relative to their counterparts in the United States and the United Kingdom. There is also a large disparity between the remuneration of Vice-Chancellors and CEOs, with the discount associated with university top management positions at 60 percent relative to the private sector. The evidence suggests that on the spectrum of organisation type from nonprofits to corporates, the traditional way in which we view universities as predominantly nonprofits is not consistent with the underlying behaviour of these institutions. This raises interesting implications for the future of higher education in Australia and the quality of the public good provided.

The Market for Vice-Chancellors

How homogenous is the market for top managerial talent? We analyse data from university annual reports on Vice Chancellors’ remuneration for the period 1995-2002 and test to see whether there is alignment between the market for Vice-Chancellors and the market for CEOs in Australia. While the responsiveness of pay to institution size is not dissimilar, Vice-Chancellors receive on average about 60 percent less than CEOs. In addition, we also compare the remuneration of Australian Vice-Chancellors to those in the United States and the United Kingdom and find that the Australians receive the highest real remuneration when using purchasing power parity exchange rates. The remuneration of Australian Vice-Chancellors is even more attractive once taxation and quality of life factors are taken into consideration. We also construct a demographic profile of Vice-Chancellors, showing that relative to CEOs, Vice-Chancellors are appointed later in life and do not have shorter tenures. Regarding Vice-Chancellor backgrounds, there is an over-representation of Vice-Chancellors from social and pure sciences and an under-representation of Vice-Chancellors from management and commerce relative to the number of award completions in those areas.

Computational analysis of the flowfield of a two-dimensional ejector nozzle

A time-iterative full Navier-Stokes code, PARC, is used to analyze the flowfield of a two-dimensional ejector nozzle system. A parametric study was performed for two controlling parameters, duct to nozzle area ratio and nozzle pressure ratio. Results show that there is an optimum area ratio for the efficient pumping of secondary flow. At high area ratios, a freestream flow passes directly through the mixing duct without giving adequate pumping. At low area ratios, the jet boundary blocks the incoming flow. The nozzle pressure ratio variation shows that the pumping rate increases as the pressure ratio increases, provided there is no interaction between the shroud wall and the shock cell structure