Termination Detection of Local Computations

Contrary to the sequential world, the processes involved in a distributed system do not necessarily know when a computation is globally finished. This paper investigates the problem of the detection of the termination of local computations. We define four types of termination detection: no detection, detection of the local termination, detection by a distributed observer, detection of the global termination. We give a complete characterisation (except in the local termination detection case where a partial one is given) for each of this termination detection and show that they define a strict hierarchy. These results emphasise the difference between computability of a distributed task and termination detection. Furthermore, these characterisations encompass all standard criteria that are usually formulated : topological restriction (tree, rings, or triangu- lated networks ...), topological knowledge (size, diameter ...), and local knowledge to distinguish nodes (identities, sense of direction). These results are now presented as corollaries of generalising theorems. As a very special and important case, the techniques are also applied to the election problem. Though given in the model of local computations, these results can give qualitative insight for similar results in other standard models. The necessary conditions involve graphs covering and quasi-covering; the sufficient conditions (constructive local computations) are based upon an enumeration algorithm of Mazurkiewicz and a stable properties detection algorithm of Szymanski, Shi and Prywes

Empty currency and the mechanics of underdevelopment within the Franc Zone

In this article, I explore why and how some fifteen African countries, member states of the Franc Zone, have, after 60 years of ‘independence’, remained dependent on, and subjugated to the patronage of France in terms of their currency, economic and development policies. More precisely, I examine the (real) politics behind the Franc des Colonies Françaises d’Afrique (CFA Franc) and Comoros Franc – the collective name of three currencies in force in the fifteen African states of the Franc Zone – whose convertibility is guaranteed by the French treasury and pegged to the Euro. I consider the rationale behind France’s commitment to guaranteeing unlimited convertibility of the CFA and Comoros Francs to the Euro, and question whether such commitment is driven by a genuine concern for development in the Franc Zone member states in question or whether other indeterminate motives justify France’s interest. I further explore the extent to which the CFA Franc impacts negatively on the right to development formember states of the Franc Zone

Thermal stability of polymethacrylic based ELIUM® resin: Effect of comonomers, antioxidants and aluminum trihydrate filler

This paper presents the study of the thermal degradation of methyl methacrylate resin based materials known as ELIUM® resin. Samples under investigation were made from MMA based resin (ELIUM® V1), ELIUM® V1 with a dimethacrylate comonomer (ELIUM® V2), and ELIUM® V2 with a stabilizer package (ELIUM® V3). They were used for trying to discuss the degradation mechanisms. Blocks differing by their thickness made from ELIUM® formulation filled with aluminum TriHydrate used as flame retardant were also investigated in order to better match some industrial materials. Degradation was observed to be mainly driven by unzipping, consistent with the methacrylic nature of ELIUM® resin. Occurrence of oxidation is also discussed depending on materials formulation and temperature. A blend of antioxidants was inefficient for limiting mass loss. At 200 °C, both ATH and ELIUM® degrade, which contributes to overall mass loss. At temperatures below 180 °C, ATH does not seem to induce new degradation mechanisms but would increase oxygen diffusivity. Finally, a first simple kinetic model is proposed to predict mass loss in thick composite blocks aged under air

Two new species of Anacaena Thomson, 1859 (Coleoptera, Hydrophilidae) from Northern Luzon, Philippines

Two species of Anacaena Thomson, 1859, A. angatbuhay sp. nov. and A. auxilium sp. nov., are described from Northern Luzon, Philippines. The new species can be distinguished through colour, body shape, surface puncturation and characteristic aedeagi. Descriptions are provided and complemented with habitus photographs and drawings of the aedeagi. Data on genus distribution in the Philippines are reviewed and an updated Philippine checklist is provided

Starting the emergency process : some reflections on presidential prerogatives in South Africa and Cameroon in time of turmoil

The study investigates and entails a crossed analysis of the legal and constitutional processes through which a state of emergency and a state of siege are brought into being within the contexts of Cameroon and South Africa. In both countries, a presidential act is required to enforce these institutions. However, the significant fact is that the status and the legal regime of such an act are different and lead to some major consequences on human rights and the rule of law. In the case of Cameroon, the presidential act declaring a state of emergency or a state of siege is an Act of state whereas in the case of South Africa, it is an Act of Parliament. The latter is subject to judicial review and parliamentary appreciation whereas the former is linked to the idea of raison d’état and is a completely presidential matter.http://www.jstor.org/journal/verfrechuberam2017Jurisprudenc

The origin and development of emergency regimes in Cameroon

The purpose of this study is to trace the origin and development of emergency regimes in Cameroon, to address their negative impact on the current structure of the political system and to highlight the need for change in the country. Emergency regimes are generally brought into being in exceptional circumstances and allow states to (legally) suspend law and infringe human rights when confronted by threats to their existence. They generally include a state of emergency, a state of exception, a state of siege and martial rule. In the case of Cameroon, these regimes are a legacy of French colonialism, and were introduced into the country's legal system to sustain harsh imperialist policies. Traditionally it is believed that a state of emergency and a state of exception are declared in response to circumstances threatening the state's existence (such as natural cataclysms, invasions, and general insurrections), but the peculiarity of these regimes in Cameroon is that they have been and still are used as a political device. Indeed, in the context of colonialism and war of independence between French colonial authorities, their local acolytes and indigenous Cameroonians, emergency regimes played a key role in eliminating political challengers, increasing the powers of the executive, and absolving it of any accountability and responsibility. However, in the process, these measures ended up losing their exceptional character as they entered the sphere of normalcy. The current hypertrophy of the powers of the executive entity in Cameroon dates back to that period, and it is consequently difficult to distinguish between a Cameroon society in crisis and one in peacetime.http://www.legalhistory.org.za/?file=fundamina2016-06-30am201

State of emergency, state of exception : a critical investigation

In fact, the exercise of emergency powers is a phenomenon common to both democratic and undemocratic governments, the only difference between the two being the presence or absence of check and balances to prevent the abuse and arbitrary use of the emergency powers by the government.1 In order to interrogate how far a state can go in legitimising arbitrariness, it is important to question whether a juridical system can provide its own suspension, as well as critically assess which scenarios provide for a state of exception or a state of emergency since vagueness can be exploited to the detriment of civil liberties of citizens and the rule of law. The main concern of the study refers to the fact that a state of exception and a state of emergency are the common denominator between the state of law, totalitarian state and authoritarian state. Emergencies situations can be considered as a threat for the enjoyment of human rights and fundamental freedoms, because separation of powers, right to a fair trial and accountability are no longer respected. From a theoretical viewpoint, two conceptions manifest themselves; the first being where a state of exception is located within a juridical order and a second location found within an extra juridical approach. Fundamentally, the nature and the function of the state of emergency and the state of exception have therefore to be contextualised for the purpose of legitimacy, accountability and relevance.Dissertation (LLM)--University of Pretoria, 2011.Centre for Human Rightsunrestricte

Thermal stability OF elium® resin and its composites

This paper deals with the thermal ageing of ELIUM® based composites filled with mineral fillers (aluminium trihydrate in particular) and corresponding matrices. The ageing of thin films and thick blocks was investigated by gravimetry. The comparison of matrices with an incremental complexity highlighted the effect of comonomers and thermal stabilizers. In all cases, unzipping was shown to be the predominant source of mass loss but oxidation seems also to be involved in the case of ageing under air. The existence of this latter was confirmed by the existence of a brown surface layer. This oxidized layer was shown to be deeper for filled composites than unfilled matrices, suggesting that fillers favor the oxygen diffusion into the bulk