Managing Uncertain Complex Events in Web of Things Applications

A critical issue in the Web of Things (WoT) is the need to process and analyze the interactions of Web-interconnected real-world objects. Complex Event Processing (CEP) is a powerful technology for analyzing streams of information about real-time distributed events, coming from different sources, and for extracting conclusions from them. However, in many situations these events are not free from uncertainty, due to either unreliable data sources and networks, measurement uncertainty, or to the inability to determine whether an event has actually happened or not. This short research paper discusses how CEP systems can incorporate different kinds of uncertainty, both in the events and in the rules. A case study is used to validate the proposal, and we discuss the benefits and limitations of this CEP extension.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

TESLA: a formally defined event specification language

The need for timely processing large amounts of information, flowing from the peripheral to the center of a system, is common to different application domains, and it has justified the development of several languages to describe how such information has to be processed. In this paper, we analyze such languages showing how most approaches lack the expressiveness required for the applications we target, or do not provide the precise semantics required to clearly state how the system should behave. Moving from these premises, we present TESLA, a complex event specification language. Each TESLA rule considers incoming data items as notifications of events and defines how certain patterns of events cause the occurrence of others, said to be "complex". TESLA has a simple syntax and a formal semantics, given in terms of a first order, metric temporal logic. It provides high expressiveness and flexibility in a rigorous framework, by offering content and temporal filters, negations, timers, aggregates, and fully customizable policies for event selection and consumption. The paper ends by showing how TESLA rules can be interpreted by a processing system, introducing an efficient event detection algorithm based on automata

On Context-Aware Publish-Subscribe

Complex communication patterns often need to take into account the characteristics of the environment, or the situation, in which the information to be communicated is produced or consumed. Publish-subscribe, and particularly its content-based incarnation, is often used to convey this information by encoding the “context ” of the publisher into the published messages, taking advantage of the expressiveness of content-based addressing to encode context-aware communication patterns. In this paper we claim that this approach is both inadequate and inefficient and propose a context-aware publish-subscribe model of communication as a better alternative. In particular, we describe the API of a new publish-subscribe model that is both content and context-based, and we explore possible routing schemas to implement this new model in a distributed publish-subscribe system potentially improving traditional content-based routing

DSOL: a declarative approach to self-adaptive service orchestrations

Service oriented computing (SOC) has brought a simplification in the way distributed applications can be built. Mainstream approaches, however, failed to support dynamic, self-managed compositions that would empower even non-technical users to build their own orchestrations. Indeed, because of the changeable world in which they are embedded, service compositions must be able to adapt to changes that may happen at run-time. Unfortunately, mainstream SOC languages, like BPEL and BPMN, make it quite hard to develop such kind of self-adapting orchestrations. We claim that this is mostly due to the imperative programming paradigm they are based on. To overcome this limitation we propose a radically different, strongly declarative approach to model service orchestration, which is easier to use and results in more flexible and self-adapting orchestrations. An ad-hoc engine, leveraging well-known planning techniques, interprets such models to support dynamic service orchestration at run-time

Trace checking of Metric Temporal Logic with Aggregating Modalities using MapReduce

Modern complex software systems produce a large amount of execution data, often stored in logs. These logs can be analyzed using trace checking techniques to check whether the system complies with its requirements specifications. Often these specifications express quantitative properties of the system, which include timing constraints as well as higher-level constraints on the occurrences of significant events, expressed using aggregate operators. In this paper we present an algorithm that exploits the MapReduce programming model to check specifications expressed in a metric temporal logic with aggregating modalities, over large execution traces. The algorithm exploits the structure of the formula to parallelize the evaluation, with a significant gain in time. We report on the assessment of the implementation - based on the Hadoop framework - of the proposed algorithm and comment on its scalability.Comment: 16 pages, 6 figures, Extended version of the SEFM 2014 pape

Espace de la coutume et enjeux civilisationnels. Témoignage sur un retour en pays Djubéa

Quand on évoque la question de l’indépendance de la Nouvelle-Calédonie, un fantasme populaire agite le fantôme du Vanuatu comme si nous avions des leçons à donner à ce peuple valeureux qui, jusqu’à lors, parvient plutôt bien à se tenir à distance de la « malbouffe », de la délinquance juvénile, et de la psychose de ses sujets et de ses foules. Or, les impasses de l’anthropocène appellent des voies civilisationnelles nouvelles. Notre être au monde, notre être ensemble sont à réinventer, à repenser et convoquent instamment des initiatives novatrices dont certaines sont déjà à l’œuvre de part le globe. Nous tenterons de mettre en évidence ici l’idée que l’espace de la coutume chez les Kanak possède le potentiel requis pour proposer une manière d’être au monde durable et avec un haut degré d’humanité, ce en quoi on peut parler de civilisation dans un espace coutumier où une symbolique raffinée met en œuvre avec application un véritable artisanat du lien social.When we raise the issue of New Caledonia’s independence, a popular fantasy stirs up the ghost of Vanuatu, as if we had lessons to teach this courageous people who, until now, have managed to maintain a distance from junk food, juvenile delinquency, and individual and collective psychosis. However, the impasses of the Anthropocene call for new civilizational paths. Our notions and practices of being-in-the-world and of togetherness have to be reinvented, to be rethought. This urgently requires novel initiatives, some of which have already been put to work elsewhere on the planet. In this paper, we attempt to put forward the idea that the space of Kanak customary practices has the required potential to offer a way of being-in-the-world that is both durable and displays a high degree of humaneness. This is why one can speak of civilization in this space of customary practices, where a refined symbolism performs a genuine craftmanship of the social

Malaise dans la colonisation. Pour une clinique de la délinquance juvénile en pays kanak

Depuis plusieurs années maintenant, la Nouvelle-Calédonie s’alarme sur un mal-être de sa jeunesse : suicide, addictions, conduites à risques… et la délinquance juvénile, qui est le phénomène du moment au regard de l’actualité locale. Elle touche principalement les Kanak, ceux des tribus proches de Nouméa, ceux des quartiers de la ville aussi, mais pas que. Le phénomène met en difficulté le sens commun quand il tente de comprendre ce type de comportement. Car l’opinion publique tend à jeter l’opprobre sur une jeunesse qui en plus d’être en difficulté se voit chargée d’une responsabilité pleine et entière de ses actes. Or, s’il existe une justice des mineurs, c’est bien parce qu’une part de cette responsabilité est tout autant celle de la famille et, avec elle, de la société. Nous développerons dans cette contribution l’idée que la délinquance juvénile en pays kanak est le symptôme d’une société calédonienne elle-même souffrante. C’est en quoi une clinique du sujet est à mener en lien étroit à une clinique du social pour écarter les évidences que donnent à voir le phénomène.For several years, New Caledonia has been worrying about its youth’s malaise and discontent as exemplified in suicides, addictions, risky behaviour and juvenile delinquency, the latter being the salient phenomenon in the local news. This mainly strikes the Kanak, those living in tribes close to Nouméa, as well as those living within urban Nouméa, but not only. It is difficult to understand such behaviour and phenomenon from the perspective of common sense. Public opinion tends to condemn this youth which, along with being helpless is laden with complete responsibility for their acts. However, the very existence of special courts for the underage points to part of the responsibility being that of the family and of society. In this contribution, we will develop the idea that juvenile delinquency in Kanak country is itself the symptom of a suffering Caledonian society. This is why a clinical approach of the subject should be conducted in close association with a clinical approach of the social. This in order to get rid of some of the all too obvious interpretations of this phenomenon

Perspectives pour une décolonisation en Nouvelle-Calédonie

La paix civile que connaît la Nouvelle-Calédonie depuis une quinzaine d’années peut être appréhendée, de manière lâche, comme la plus large avancée réalisée sur ce territoire. Nonobstant ce premier constat encourageant, il n’est pas du tout évident que les évolutions futures du territoire se déroulent sous les meilleurs auspices en terme de décolonisation. Pourtant, confortée par le droit international, la décolonisation de la Nouvelle-Calédonie semble parsemée d’obstacles que nous nous proposons de mettre en mots en posant, dans un premier temps, une analyse sur l’éclatement du FLNKS. Puis, nous chercherons à estimer la portée de la dynamique suggérée par le processus de développement économique amorcé en 1988. Nous nous demanderons en quoi l’idéologie développementiste peut représenter une nouvelle forme de colonialisme, et si cette idéologie fièrement portée par les accords de Matignon et de Nouméa (1988-1998) contribue réellement au rattrapage des inégalités et au rééquilibrage.The peace that New Caledonia has experienced for about fifteen years can be apprehended, as greatest progress on this territory. Notwithstanding this first encouraging report, it is not at all obvious that the future evolutions of the territory will proceed under the best auspices in terms of decolonization. However, consolidated by international law, the decolonization of New Caledonia seems strewn with obstacles that we propose to analyse by first assessing the scission of the FLNKS. We will then estimate the range of dynamics suggested by the process of economic development which brought in a new era in 1988. We shall question the way the developmentist ideology may represent a new form of colonialism, and if this ideology proudly defended by the Accords (1988-1998) really contributes to the correction of the inequalities and the rebalancing

Perfecting nature : Friedrich Nietzsche\u27s ideal and politics of cultivation

What I have called the Ideal of Cultivation is a fundamental ethical principle of civilisation, originated by aristocratic warriors in Greek antiquity who held that the true purpose of humanity is to perfect natureIt was then professed that individuals and even entire peoples could consciously develop and improve themselves in a way that was thought to obey the original lawful impulses of nature, a process which was likened to those of agriculture and animal husbandry.Subsequently the cognate idea of a politics of cultivation arose which deemed that society should be organised specifically to produce more virtuous or perfect human types. Given their fundamental association with Hellenism both ideas have been revisited constantly in the intellectual history of the west, and most notably during the great secular periods, the Renaissance and Enlightenment when active attempts were made to retrieve the ideals of antiquity. Both ideas were particularly pervasive in the German enlightenment, the Aufklärung, and were assimilated by the succeeding Romantic generation.In nineteenth century Germany, when interest in these ideas was quickly waning, the German philosopher Friedrich Nietzsche acquired an unswerving attachment to them and made the service of them his life\u27s work.The intention of this essay is to trace methodically the appearance of the Ideal of Cultivation in Nietzsche\u27s philosophy and politics, and to outline his responses to a world which was abandoning the principles in which he deeply believed. This essay should be regarded as a case study in the long history of a fundamental ethical idea rather than one about the philosopher Nietzsche

AIOCJ: A Choreographic Framework for Safe Adaptive Distributed Applications

We present AIOCJ, a framework for programming distributed adaptive applications. Applications are programmed using AIOC, a choreographic language suited for expressing patterns of interaction from a global point of view. AIOC allows the programmer to specify which parts of the application can be adapted. Adaptation takes place at runtime by means of rules, which can change during the execution to tackle possibly unforeseen adaptation needs. AIOCJ relies on a solid theory that ensures applications to be deadlock-free by construction also after adaptation. We describe the architecture of AIOCJ, the design of the AIOC language, and an empirical validation of the framework.Comment: Technical Repor