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 verification in international relations: 1945-1993

The role of verification in international relations is liked with the urge to verify which is evident throughout human history. This study focused on the evolution of this role in light of political circumstances and technological progress. Several different approaches to verification can be identified – bilateral, regional cooperation, global arrangements, and individual national efforts. Moreover, several themes characterize the existing verification regimes. These issues – namely the sharing of intelligence, managing compliance questions, and the integration of different regimes – present themselves as the negotiating ground for future years. One of the important result of the paper is that it demonstrates how the concept of verification, once a contentious political instrument, is encompassing anew actors, new frameworks, new technologies, and new fields

UNCOVERING HIDDEN FRONTS OF AFRICA’S LIBERATION STRUGGLE: BLACK POWER, BLACK CONSCIOUSNESS, AND SOUTH AFRICA’S ARMED STRUGGLE, 1967-1985

Many scholars have argued the Black Consciousness Movement (BCM)’s principal contribution was as an intellectual/student movement, and its main shortcoming the limited degree of active political and military opposition it was able to offer the apartheid regime. My dissertation, ‘Uncovering Hidden Fronts of Africa’s Liberation Struggle: Black Power, Black Consciousness, and South Africa’s Armed Struggle, 1967–1985’, broadens our understanding of this movement and moment in South African history by unearthing the little known history of BCM’s unrelenting engagement with armed struggle as a form of resistance to apartheid rule during the 1970s and 1980s. The first part of my dissertation charts the evolution of Black Consciousness (BC) inspired organisations such as the Azanian People’s Liberation Front (APLF), the Isandlwana Revolutionary Effort (IRE), and the South African Youth Revolutionary Council (SAYRCO) from 1974–1982 as they organised for armed confrontation with the apartheid state. It then moves to a discussion of the Black Consciousness Movement of Azania (BCMA) and its armed wing the Azanian National Liberation Army (AZANLA) that emerged in the 1980s as the BC alternative to the non-racialist nominally socialist African National Congress of South Africa (ANC-SA) after previous movements failed to consolidate themselves. Their failures are less important than examinations of why they failed, which reveals their struggles were mostly caused by BCM being outmanoeuvred and betrayed by the ANC-SA and the Pan Africanist Congress of Azania (PAC) in exile. The second part of my dissertation excavates how many new recruits of the Soweto generation attempted to radicalize Umkhonto We Sizwe (MK) from within. While this is acknowledged by most MK scholars, they do not link this drive for radicalization with the politics of BC that a number of these recruits carried with them into the movement. From this perspective, the mutinies and internal suppressions that wracked MK during the 1980s need to be viewed as an internal ideological struggle for what the future of South Africa would look like. Although my work offers a careful historical reconstruction of previously under-explored events, my thesis suggests BCM’s vision of a future South Africa/Azania, where land and resources would be redistributed to the masses, was outmanoeuvred and defeated by bourgeois liberal-democratic and South African Communist Party (SACP) forces of the ANC-SA. Returning to this history helps frame contemporary struggles South Africa finds itself in as current movements strive to find answers to continued racism and economic inequality. While BC did not have all the answers, it offered a different vision of freedom that Black activists today have rediscovered