The many ways of coping with pressure

En libre-accès sur Archimer : http://archimer.ifremer.fr/doc/00027/13797/11043.pdfInternational audienceThe current paper reviews strategies employed by microorganisms from the deep biosphere, especially piezophiles (from the greek piezo = to press and philo = love), to cope with high hydrostatic pressure (HHP) prevailing in these biotopes. The aim of this review is not to constitute an exhaustive report of our current knowledge on the physiology of piezophiles, as recent reviews have covered part of this subject in detail (Abe, 2007; Lauro and Bartlett, 2008; Michiels et al., 2008; Simonato et al., 2006). Rather, we illustrate here, via a few chosen examples, where we stand in our understanding of the mechanisms employed by microorganisms from the depths of our planet to cope with HHP

Quelques aspects de la conception critique en sémiotique D’El Mostafa Chadli

L’intérêt porté aux travaux de recherche du Dr. El Mostafa Chadli s’est focalisé surdeux travaux importants, dont l’auteur de l’article a assuré la traduction en langue arabe :• Le premier ouvrage concerne Le Structuralisme dans les sciences du langage qui retrace la genèse et l’histoire du mouvement structuraliste et met en relief l’influence qu’il a exercé sur l’ensemble des sciences humaines et sociales ;• Le second ouvrage porte sur Le Conte merveilleux marocain. Sémiotique du texteethnographique, où le conte est considéré comme un texte ethnographique et soumis au déploiement de l’analyse sémiotique, enrichie par les apports de la linguistique de l’énonciation, la sémantique interprétative et la pragmatique

Remote Phobia Treatment as a Tactile Internet Application Case Study in Edge augmented with Mobile Ad Hoc Clouds Environment

Tactile Internet is a next generation Internet that allows the transmission of haptic sensations in addition to audio and video content. It is expected to enable new latency-sensitive and critical use cases, such as remote phobia treatment, tele-surgery and autonomous driving. However, the current networking infrastructure cannot ensure the strict requirements that come with Tactile Internet, namely ultra-responsiveness and ultra-reliability. \indent Edge computing can help in solving this issue. While Cloud Computing offers powerful computing resources at distant data centers, Edge computing provides resources closer to the end user. To this end, computations can be offloaded from the cloud to the edge to obtain lower latency. In addition, as the Edge itself may prove to be insufficiently close to the end users’ devices in some cases, it can be augmented with Mobile Ad-Hoc Clouds. The Mobile Ad-hoc Clouds refer to a group of mobile devices located at the immediate vicinity of the end users, offering their available resources for computation, leading therefore to a reduced latency. Nevertheless, the design and implementation of an architecture based on edges augmented with mobile ad-hoc clouds for Tactile Internet raises several challenges. Firstly, a tactile internet-based architecture for remote phobia treatment should allow the exchange of auditory, visual and haptic information to ensure the efficiency of the therapy. Secondly, the end to end latency should be in the order of a few milliseconds to avoid “cyber-sickness”. \indent This thesis provides a case study of edge augmented with mobile ad-hoc clouds architecture for remote phobia treatment. The contributions are threefold. First, a software architecture for remote phobia treatment is designed for an edge augmented with mobile ad hoc clouds environment. Second, a proof of concept prototype for the proposed architecture is implemented and evaluated using a set of haptic devices, which include the HTC Vive VR headset, the Leap Motion hand tracking device, as well as the Gloveone haptic glove. Third, a set of experiments consisting of placing the components in the different layers (i.e. Cloud, Edge and Mobile Ad-hoc Cloud) were conducted, which allowed an evaluation of the impact on performance. A set of high-level interfaces were introduced to allow communication with the heterogeneous devices. The design of the architecture as a set of software modules allows the reusability of the architecture

Live Testing of Cloud Services

Service providers use the cloud due to the dynamic infrastructure it offers at a low cost. However, sharing the infrastructure with other service providers as well as relying on remote services that may be inaccessible from the development environment create major limitations for development time testing. Modern service providers have an increasing need to test their services in the production environment. Such testing helps increase the reliability of the test results and detect problems that could not be detected in the development environment such as the noisy neighbor problem. Furthermore, testing in production enables other software engineering activities such as fault prediction and fault localization and makes them more efficient. Test interferences are a major problem for testing in production as they can have damaging effects ranging from unreliable and degraded performance to a malfunctioning or inaccessible system. The countermeasures that are taken to alleviate the risk of test interferences are called test isolation. Existing approaches for test isolation have limited applicability in the cloud context because the assumptions under which they operate are seldom satisfied in the cloud context. Moreover, when running tests in production, failures can happen and whether they are due to the testing activity or not the damage they cause cannot be ignored. To deal with such issues and manage to quickly get the system back to a healthy state in the case of a failure, human intervention should be reduced in the orchestration and execution of testing activities in production. Thus, the need for a solution that automates the orchestration of tests in production while taking into consideration the particularity of a cloud system such as the existence of multiple fault tolerance mechanisms. In this thesis, we define live testing as testing a system in its production environment, while it is serving, without causing any intolerable disruption to its usage. We propose an architecture that can help cope with the major challenges of live testing, namely reducing human intervention and providing test isolation. Our proposed architecture is composed of two building blocks, the Test Planner and the Test Execution Framework. To make the solution we are proposing independent from the technologies used in a cloud system, we propose the use of UML Testing Profile (UTP) to model the artifacts involved in this architecture. To reduce human intervention in testing activities, we start by automating test execution and orchestration in production. To achieve this goal, we propose an execution semantics that we associate with UTP concepts that are relevant for test execution. Such an execution semantics represent the behavior that the Test Execution Framework exhibits while executing tests. We propose a test case selection method and test plan generation method to automate the activities that are performed by the Test Planner. To alleviate the risk of test interferences, we also propose a set of test methods that can be used for test isolation. As opposed to existing test isolation techniques, our test methods do not make any assumptions about the parts of the system for which test isolation can be provided, nor about the feature to be tested. These test methods are used in the design of test plans. In fact, the applicability of each test method varies according to several factors including the risk of test interferences that parts of the system present, the availability of resources, and the impact of the test method on the provisioning of the service. To be able to select the right test method for each situation, information about the risk of test interference and the cost of test isolation need to be provided. We propose a method, configured instance evaluation method, that automates the process of obtaining such information. Our method evaluates the software involved in the realization of the system in terms of the risk of test interference it presents, and the cost to provide test isolation for that software. In this thesis, we also discuss the feasibility of our proposed methods and evaluate the provided solutions. We implemented a prototype for the test plan generation and showcased it in a case study. We also implemented a part of the configured instance evaluation method, and we show that it can help confirm the presence of a risk of test interference. We showcase one of our test methods on a case study using an application deployed in a Kubernetes managed cluster. We also provide proof of the soundness of our execution semantics. Furthermore, we evaluate, in terms of the resulting test plan’s execution time, the algorithms involved in the test plan generation method. We show that for two of the activities in our solution our proposed algorithms provide optimal solutions; and, for one activity we identify in which situations our algorithm does not manage to give the optimal solution. Finally, we prove that our test case selection method reduces the test suite without compromising the configuration fault detection power

Proyecto de señalización de interés turístico - histórico en sendero de acceso al Castillo de Bairén, Gandía

Se ha realizado la localización de una zona donde poder desarrollar dicha señalización. Se estudiaron los alrededores con buena accesibilidad y se descubrió que la zona poseía gran cantidad de fuentes histórica, paisajística, turística, ecológica y faunística debido a su ubicación dentro del municipio Gandía. Por todo esto, se ha decidido señalar la senda de acceso al Castillo de Bairén, de esta manera, se puede dar a conocer a todas las personas que lo deseen la gran belleza paisajística e histórica del lugar. Señalizar la senda, con el fin de facilitar el acceso y fomentar el conocimiento de algunas notas de vegetación e historia del lugar, para diversificar la oferta turística de la localidad. Así, la señalización de la senda del castillo de Bairén facilita el acceso y fomenta el conocimiento de algunas notas de vegetación e historia del lugar mediante la instalación de paneles informativos, a la vez que da la oportunidad de dar un agradable paseo por la naturaleza con unas buenas vistas de los alrededores, dada la estratégica localización del mismo y ampliar la vasta oferta de ocio-deporte y cultura de la localidad.Jebbar, I. (2013). Proyecto de señalización de interés turístico - histórico en sendero de acceso al Castillo de Bairén, Gandía. Universitat Politècnica de València. http://hdl.handle.net/10251/31484Archivo delegad

Model Driven Upgrade Campaign Specification Generation and Evaluation

Oussama Jebbar High availability is an important non-functional requirement for carrier grade services. The applications/systems providing and protecting such services undergo frequent upgrades which makes meeting this requirement very challenging. A system upgrade is the migration process from the system’s current configuration to a new one. This migration may include configuration changes, installation and removal of software, etc.. The Service Availability Forum (SAF) published a set of standards that describe a high availability enabling middleware for Commercial-off-the-shelf (COTS) components based systems. In such a middleware, the Software Management Framework (SMF) is the service responsible for orchestrating the upgrades. These upgrades are performed according to a road map called an upgrade campaign specification. The Availability Management Framework (AMF) is another service defined in the SAF standards and which is responsible of managing the availability of the services and the service providers. To take a SAF compliant system from one configuration to another, one has first to come up with an upgrade campaign specification for that purpose. Moreover, there are multiple upgrade campaign specifications that can take the system from the same source configuration to the same target configuration, but they differ in the duration they take and the service outage they may induce. Designing an upgrade campaign specification for a SAF compliant system is not a straight forward process. Indeed, this is an error prone task that becomes more challenging when the system and the set of changes to perform get larger. Besides, selecting which upgrade campaign specification to apply among all the valid ones is either expensive (running the same upgrade campaign specification on a replica of the real system), or tedious (evaluating, comparing and selecting upgrade campaign specifications manually). In this thesis we propose automation as a solution to ease and minimize human intervention in the design and evaluation of upgrade campaign specifications. We devise a model driven approach to automatically generate upgrade campaign specifications. Our approach consists of several activities in order to ensure the SAF compliance of the generated upgrade campaign specification on one hand. On the other hand, we use the dependencies between system components to apply a set of rules that can improve the quality of the upgrade campaign specification by avoiding some of the unnecessary service outage. These rules include rules to order changes to be performed as well as a set of heuristics that make use of the dependencies. We also address the upgrade campaign evaluation related issues. We extend an existing discrete event systems based simulation approach for upgrade campaign evaluation. We expose the limitations of a random simulation as its results are unreliable for comparison. To overcome these limitations we define best case and worst case scenarios that we use to guide upgrade campaign simulations to see how the upgrade campaigns perform in edge cases. We also devise a method for upgrade campaign specification selection/elimination based on applicability checks according to two criteria: the maintenance window, and the acceptable outage during this window. Finally, we implemented prototypes for upgrade campaign specification generation and evaluation

A fog-based architecture for remote phobia treatment

© 2019 IEEE. Tactile Internet is a next generation Internet. It allows the exchange of haptic sensations in addition to audio and video content. It is a key enabler of several emerging applications as remote robotic surgery and autonomous driving, when combined with 5G and Edge Computing. Because Tactile Internet will enable mission critical applications, it has to adhere to strict requirements, mainly in terms of ultra-responsiveness, ultra-reliability and security. In this paper, we propose a fog-based architecture for remote phobia treatment, a Tactile Internet application. The proposed architecture offers a set of software modules that allow a phobia patient to have a therapy session, under the guidance of an expert therapist located remotely, with the patient and the therapist sharing the same virtual reality environment. We use the fog paradigm to meet the stringent Tactile Internet requirements, namely the round trip latency of 1ms. The components of the architecture offer high level interfaces to simplify interaction with external software components as well as with a wide range of hardware devices. A prototype is also implemented and the performance is discussed

Enhancing feature selection with a novel hybrid approach incorporating genetic algorithms and swarm intelligence techniques

Computing advances in data storage are leading to rapid growth in large-scale datasets. Using all features increases temporal/spatial complexity and negatively influences performance. Feature selection is a fundamental stage in data preprocessing, removing redundant and irrelevant features to minimize the number of features and enhance the performance of classification accuracy. Numerous optimization algorithms were employed to handle feature selection (FS) problems, and they outperform conventional FS techniques. However, there is no metaheuristic FS method that outperforms other optimization algorithms in many datasets. This motivated our study to incorporate the advantages of various optimization techniques to obtain a powerful technique that outperforms other methods in many datasets from different domains. In this article, a novel combined method GASI is developed using swarm intelligence (SI) based feature selection techniques and genetic algorithms (GA) that uses a multi-objective fitness function to seek the optimal subset of features. To assess the performance of the proposed approach, seven datasets have been collected from the UCI repository and exploited to test the newly established feature selection technique. The experimental results demonstrate that the suggested method GASI outperforms many powerful SI-based feature selection techniques studied. GASI obtains a better average fitness value and improves classification performance

Correlation between clinical findings and magnetic resonance imaging findings in meniscal and anterior cruciate ligament injuries

Background: This study aims to compare the correlation between clinical findings and magnetic resonance imaging with arthroscopic findings in meniscal and anterior cruciate ligament (ACL) injuries.Methods: This was a prospective study of 60 patients with ACL and meniscal injuries of the knee who were admitted between October 2020 and October 2021, who underwent clinical examination, MRI, and arthroscopy of the knee.Results: In our study of 60 cases, there were 44 male and 16 female patients ranging from 18 to 45 years, with the majority of patients between the ages of 25 and 35. The clinical examination had a sensitivity of 88%, specificity of 100%, and accuracy of 90% for ACL, the sensitivity of 80%, specificity of 100%, and accuracy of 90% for medial meniscus, and sensitivity of 50%, specificity of 100%, and accuracy of 83.33% for lateral meniscus. Magnetic resonance imaging (MRI) had a sensitivity of 100%, specificity of 100%, and accuracy of 100% for ACL, the sensitivity of 100%, specificity of 66.67%, and accuracy of 83.33% for medial meniscus, and sensitivity of 100%, specificity of 85%, and accuracy of 90% for lateral meniscus.Conclusions: In conclusion, the current investigation emphasizes the importance of clinical diagnosis, as the positive predictive value (PPV) for all lesions is high. An MRI provides an additional diagnostic tool for ligament and meniscal injuries of the knee. The diagnostic accuracy of all lesions was in the 90th percentile. Because the negative predictive value (NPV) for all lesions is substantial, MRI is utilized to confirm the diagnosis and rule out pathology