Hard real-time multiprocessor scheduling resilient to core failures

Presented at 21st IEEE International Conference on Embedded and Real-Time Computing Systems and Applications (RTCSA 2015). 19 to 21, Aug, 2015, pp 122-131. Hong Kong, China.

TIMWE: IPO go or no go?

A Work Project, presented as part of the requirements for the Award of a Masters Degree in Finance from the NOVA – School of Business and Economics

IPO impact on industry incumbents

The creation of an innovative company is suggestive of change in an industry. To test that change this paper tests the impact of IPOs on industry incumbents. IPOs are found to happen in industries that exhibited positive abnormal returns for up to 5 years before the IPO date. The IPO date is found to coincide with the end of that industry abnormal return profile. This paper suggests this evidence is consistent with the IPO acting as mechanism of enforcing market efficiency at the industry level.

Perceptions de personnes atteintes de cancer quant au soutien offert par l'IPO dans la période entourant l'annonce du diagnostic

L’annonce d’un diagnostic de cancer devrait être considérée par les professionnels de la santé, comme un processus constitué de plusieurs étapes que doit traverser la personne atteinte, plutôt que comme un évènement en soi (Tobin & Begley, 2008). Lors de la période entourant l’annonce du diagnostic, la personne peut être confrontée à des difficultés reliées à la navigation dans un système de santé complexe, en plus des sentiments négatifs engendrés par la crainte de la maladie. Pour soutenir les personnes atteintes de cancer, le programme québécois de lutte contre le cancer (PQLCC), a instauré le rôle de l’infirmière pivot en oncologie (IPO) en 2000. À l’heure actuelle, peu d’études, à notre connaissance, se sont attardées au soutien de l’IPO dans cette période. La présente étude avait pour but, d’explorer les perceptions de personnes atteintes de cancer quant au soutien offert par l’IPO, dans la période entourant l’annonce du diagnostic. L’étudiante-chercheuse s’est inspirée du Cadre de soins de soutien de Fitch (1994) pour entreprendre cette étude qualitative descriptive. Des entrevues individuelles auprès de sept personnes atteintes de différents cancers ont été réalisées. L’analyse de données a été effectuée à l’aide de la méthode de Miles et Huberman (2003), par la transcription intégrale des entrevues. Elle a permis d’identifier trois thèmes soit : le soutien formel requis pour faire face au chaos, le soutien informationnel et émotionnel à parfaire et le soutien disponible apportant sécurité et assurance. Les résultats ont mis en évidence les perceptions de personnes atteintes de cancer quant au soutien offert par l’IPO soit la nécessité de rendre accessible les soins et services de l’IPO plus tôt dans la période entourant l’annonce du diagnostic. Les personnes atteintes de cancer ont besoin d’être aidées à faire face aux difficultés rencontrées lors de cette période, notamment à l’incertitude reliée aux résultats d’examens diagnostics, à l’incompréhension des informations reçues et aux sentiments négatifs engendrés par la menace de la maladie. Les résultats évoquent le souhait des participants, à l’effet que, l’offre de soutien de l’IPO, soit axée sur leurs besoins essentiellement dans les domaines informationnel et émotionnel. Ils auraient souhaité pouvoir, partager leur expérience avec l’IPO, mieux comprendre le diagnostic de cancer et savoir davantage à quoi s’attendre lors du début des traitements. Par ailleurs, savoir que le soutien de l’IPO est disponible apporte aux personnes atteintes de cancer une assurance et une confiance en leur capacité à faire face aux traitements et leur apporte un sentiment de sécurité.

Lower Bounds for Achieving Synchronous Early Stopping Consensus with Orderly Crash Failures

In this paper, we discuss the consensus problem for synchronous distributed systems with orderly crash failures. For a synchronous distributed system of n processes with up to t crash failures and f failures actually occur, first, we present a bivalency argument proof to solve the open problem of proving the lower bound, min (t + 1, f + 2) rounds, for early-stopping synchronous consensus with orderly crash failures, where t < n - 1. Then, we extend the system model with orderly crash failures to a new model in which a process is allowed to send multiple messages to the same destination process in a round and the failing processes still respect the order specified by the protocol in sending messages. For this new model, we present a uniform consensus protocol, in which all non-faulty processes always decide and stop immediately by the end of f + 1 rounds. We prove that the lower bound of early stopping protocols for both consensus and uniform consensus are f + 1 rounds under the new model, and our proposed protocol is optimal.

Robustness against large-scale failures in communications networks

This thesis studies robustness against large-scale failures in communications networks. If failures are isolated, they usually go unnoticed by users thanks to recovery mechanisms. However, such mechanisms are not effective against large-scale multiple failures. Large-scale failures may cause huge economic loss. A key requirement towards devising mechanisms to lessen their impact is the ability to evaluate network robustness. This thesis focuses on multilayer networks featuring separated control and data planes. The majority of the existing measures of robustness are unable to capture the true service degradation in such a setting, because they rely on purely topological features. One of the major contributions of this thesis is a new measure of functional robustness. The failure dynamics is modeled from the perspective of epidemic spreading, for which a new epidemic model is proposed. Another contribution is a taxonomy of multiple, large-scale failures, adapted to the needs and usage of the field of networking.

Handling single node failures using agents in computer clusters

The work reported in this paper is motivated towards handling single node failures for parallel summation algorithms in computer clusters. An agent based approach is proposed in which a task to be executed is decomposed to sub-tasks and mapped onto agents that traverse computing nodes. The agents intercommunicate across computing nodes to share information during the event of a predicted node failure. Two single node failure scenarios are considered. The Message Passing Interface is employed for implementing the proposed approach. Quantitative results obtained from experiments reveal that the agent based approach can handle failures more efficiently than traditional failure handling approaches.

UK innovation systems for new and renewable energy technologies: drivers, barriers and systems failures

A better understanding of the systemic processes by which innovation occurs is useful, both conceptually and to inform policymaking in support of innovation in more sustainable technologies. This paper analyses current innovation systems in the UK for a range of new and renewable energy technologies, and generates policy recommendations for improving the effectiveness of these innovation systems. Although incentives are in place in the UK to encourage innovation in these technologies, system failures—or ‘gaps’—are identified in moving technologies along the innovation chain, preventing their successful commercialisation. Sustained investment will be needed for these technologies to achieve their potential. It is argued that a stable and consistent policy framework is required to help create the conditions for this. In particular, such a framework should be aimed at improving risk/reward ratios for demonstration and pre-commercial stage technologies. This would enhance positive expectations, stimulate learning effects leading to cost reductions, and increase the likelihood of successful commercialisation.

Hot and cold IPO markets : the case of the stock exchange of Mauritius

The aim of this study is to assess the characteristics of the hot and cold IPO markets on the Stock Exchange of Mauritius (SEM). The results show that the hot issues exhibit, on average, a greater degree of underpricing than the cold issues, although the hot issue phenomenon is not a significant driving force in explaining this short-run underpricing. The results are consistent with the predictions of the changing risk composition hypothesis in suggesting that firms going public during hot markets are on average relatively more risky. The findings also support the time adverse selection hypothesis in that the firms’ quality dispersion is statistically different between hot and cold markets. Finally, the study concludes that firms which go public during hot markets do not underperform those going public in cold markets over the longer term.