Application of learning algorithms to traffic management in integrated services networks.

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Incentive-driven QoS in peer-to-peer overlays

A well known problem in peer-to-peer overlays is that no single entity has control over the software, hardware and configuration of peers. Thus, each peer can selfishly adapt its behaviour to maximise its benefit from the overlay. This thesis is concerned with the modelling and design of incentive mechanisms for QoS-overlays: resource allocation protocols that provide strategic peers with participation incentives, while at the same time optimising the performance of the peer-to-peer distribution overlay. The contributions of this thesis are as follows. First, we present PledgeRoute, a novel contribution accounting system that can be used, along with a set of reciprocity policies, as an incentive mechanism to encourage peers to contribute resources even when users are not actively consuming overlay services. This mechanism uses a decentralised credit network, is resilient to sybil attacks, and allows peers to achieve time and space deferred contribution reciprocity. Then, we present a novel, QoS-aware resource allocation model based on Vickrey auctions that uses PledgeRoute as a substrate. It acts as an incentive mechanism by providing efficient overlay construction, while at the same time allocating increasing service quality to those peers that contribute more to the network. The model is then applied to lagsensitive chunk swarming, and some of its properties are explored for different peer delay distributions. When considering QoS overlays deployed over the best-effort Internet, the quality received by a client cannot be adjudicated completely to either its serving peer or the intervening network between them. By drawing parallels between this situation and well-known hidden action situations in microeconomics, we propose a novel scheme to ensure adherence to advertised QoS levels. We then apply it to delay-sensitive chunk distribution overlays and present the optimal contract payments required, along with a method for QoS contract enforcement through reciprocative strategies. We also present a probabilistic model for application-layer delay as a function of the prevailing network conditions. Finally, we address the incentives of managed overlays, and the prediction of their behaviour. We propose two novel models of multihoming managed overlay incentives in which overlays can freely allocate their traffic flows between different ISPs. One is obtained by optimising an overlay utility function with desired properties, while the other is designed for data-driven least-squares fitting of the cross elasticity of demand. This last model is then used to solve for ISP profit maximisation

The role of inhibitory control in the cooperative play of high-functioning children with autism

This thesis contributes to the executive dysfunction account of autism by demonstrating that impairments in inhibitory control, an aspect of executive functioning, are partially responsible for deficits in the cooperative play of highfunctioning children with autism (HFA). As past research on whether inhibitory control is impaired in autism has been inconclusive, a meta-analysis of 42 empirical studies (57 effect sizes, total n = 2,256) was conducted, which provided clear evidence for impaired inhibition in HFA children. It was also found that the degree of impairment shown does not vary across measures of inhibition, which has important methodological implications for future research. Two experimental studies were carried out to directly test the link between inhibition and three components of cooperation: reciprocity, accepting the play partner’s input, and fairness. In study one, HFA children in primary school and agematched typically-developing (TD) peers were tested on engaging in joint attention, theory of mind (ToM), measures of inhibition, and a cooperative drawing task. The groups did not differ on first-order ToM and joint attention, but HFA participants demonstrated poorer inhibitory control and less cooperative behaviour. Importantly, the degree of impairment in inhibitory control predicted reciprocity and accepting the play partner’s input in HFA children. The second experimental study investigated whether poor inhibitory control can explain the well-established discrepancy between moral reasoning and actual sharing behaviour. A sample of HFA and TD children of primary school age completed a moral reasoning interview, inhibitory control tasks, and a Dictator Game. The results showed that while HFA children demonstrated age-typical levels of moral reasoning and sharing, inhibitory control emerged as the most important predictor of sharing behaviour, lending support to the hypothesis that the ability to suppress one’s own desires is a prerequisite of acting considerately. The last study comprises a qualitative investigation of TD children’s experience of engaging in cooperative play with their sibling who has a diagnosis of HFA. Six children between the ages of 5 and 11 were interviewed, and their reports analysed using interpretative phenomenological analysis (IPA). Five themes emerged: poor emotion regulation, restricted interests, and no acceptance of the playmate’s contributions reduced the hedonistic value of joint play for the participants, but these were mitigated by appreciation for the HFA sibling’s creativity and adjustment to the HFA sibling’s behavioural atypicalities. These results can inform the development of support programmes for TD siblings and social skills training for HFA children. Overall, the results of the studies included in this thesis provide evidence that deficits in inhibitory control moderate the relationship between relatively intact social knowledge and impaired social competence in HFA children. This refinement of the executive dysfunction account is a useful building block for an improved multiple-deficit model of the autism phenotype

"Hey! They're trying to learn for free!": An Analysis of The Simpsons as a Satirical Portrayal of Neoliberal Influence on Public Education

Rooted in the philosophy of Michael W. Apple, this thesis examines how The Simpsons has portrayed neoliberalism’s influence on public education. This thesis begins by reviewing literature related to The Simpsons’ ideological thrust. It considers how The Simpsons is rooted in a left-of-centre antagonism towards American hegemony, yet the program will mock anything it deems worthy of ridicule. Next, a framework of neoliberalism as it relates to public education is built using the works of Michael W. Apple. Four specific categories are put forth: privatisation, marketisation, performativity, and the enterprising individual. These categories form the basis of the conceptual content analysis that sampled each of The Simpsons’ 12 seasons before the 2001 introduction of No Child Left Behind, the United States’ widely-discussed neoliberal reform package to public education. The research data is explicated in a series of four chapters, each discussing how The Simpsons’ portrayals of education reflects neoliberalism as perceived by Apple. What emerged was that while The Simpsons tended to critique teachers and schools in a manner similar to what neoliberal ideology contends, when Springfield Elementary enveloped the neoliberal values and reforms that are believed to be a “fix” for education, it was most often further damaged. Because of this cynicism towards neoliberal reforms, this thesis concludes that The Simpsons provides wider opportunity to expose and discuss the folly of neoliberalism’s influence on public education