A hierarchic approach for path planning in virtual reality.

This work considers path-planning processes for manipu- lation tasks such as assembly, maintenance or disassem- bly in a virtual reality (VR) context. The approach con- sists in providing a collaborative system associating a user immersed in VR and an automatic path planning process. It is based on semantic, topological and geometric representations of the environment and the planning process is split in two phases: coarse and fine planning. The automatic planner suggests a path to the user and guides him trough a haptic device. The user can escape from the proposed solution if he wants to explore a possible better way. In this case, the interactive system detects the users intention and computes in real-time a new path starting from the users guess. Experiments illustrate the different aspects of the approach: multi-representation of the en- vironment, path planning process, users intent prediction and control sharing

Interactive multimodal Path Planning in immersion

Recent studies have defined interactive path plan- ners for simulations involving a human operator. Such path planners enable a human operator to share control with an automatic planner and are based on Robotics and Virtual Reality (VR) methods. This paper proposes a novel architecture for this interactive planner. It enhances interaction with the user by adding topological and semantic representations to the purely geometric model traditionally used

A multi-layer approach of interactive path planning for assisted manipulation in virtual reality

This work considers Virtual Reality (VR) applications dealing with objects manipulation (such as industrial product assembly, disassembly or maintenance simulation). For such applications, the operator performing the simulation can be assisted by path planning techniques from the robotics research field. A novel automatic path planner involving geometrical, topological and semantic information of the environment is proposed for the guidance of the user through a haptic device. The interaction allows on one hand, the automatic path planner providing assistance to the human operator, and on the other hand, the human operator to reset the whole planning process suggesting a better suited path. Control sharing techniques are used to improve the assisted manipulation ergonomics by dynamically balancing the automatic path planner authority according to the operator involvement in the task, and by predicting user’s intent to integrate it as early as possible in the planning process

Generalized inverses applied to Pulse Width Modulation for static conversion: a first study

This paper points out the generic matrix approach to design Pulse Width Modulation strategies of three-phase Voltage Source Inverters. This well-known problem has infinitely many solutions, and many modulation methods already exist. This mathematical approach deserves to be explored by its rigor and mustidentify known but also new solution

Using virtual reality and 3D industrial numerical models for immersive interactive checklists

At the different stages of the PLM, companies develop numerous checklist-based procedures involving prototype inspection and testing. Besides, techniques from CAD, 3D imaging, animation and virtual reality now form a mature set of tools for industrial applications. The work presented in this article develops a unique framework for immersive checklist-based project reviews that applies to all steps of the PLM. It combines immersive navigation in the checklist, virtual experiments when needed and multimedia update of the checklist. It provides a generic tool, independent of the considered checklist, relies on the integration of various VR tools and concepts, in a modular way, and uses an original gesture recognition. Feasibility experiments are presented, validating the benefits of the approach

Couplages électro-thermo-mécaniques dans les modules de puissance fortement intégrés

Ce travail fait un bilan des actions de recherche menées dans le cadre de la thématique Electronique de puissance au sein du laboratoire Génie de Production de Tarbes (études expérimentales et modélisation)

Month of Birth, a Risk Factor for Violent Behaviour in Suicidal Patients Admitted in Emergency?

Although there are numerous publications on the existing link between month of birth and suicide, only two studies focus on suicide attempts and auto-aggressive behavior. Research data suggest that month of birth is related to a variation of 5-HIAA in the cerebrospinal fluid, which correlates with violent behavior (VB). Therefore, the aim of this study is to search, for the first time, for a possible link between month of birth and the occurrence of VB in emergency, for patients admitted for a suicide attempt with medication. This is a 10months prospective study among all the patients of the canton of Geneva, Switzerland, admitted in emergency for a suicide attempt with medication. During a 10months study period we included 493 patients, of which 77 (15.62%) presented VB. Higher incidence of VB was found in subjects where born at the end of winter and the beginning of spring, with a maximum for April and a minimum for December. In spite of a relatively small number of subjects, it seems promising to study the occurrence of VB as a function of month of birth in patients admitted in emergency for a suicide attemp

Bat urea-derived minerals in arid environment. First identification of allantoin, C4H6N4O3, in Kahf Kharrat Najem Cave, United Arab Emirates

Kahf Kharrat Najem Cave is a small cave in United Arab Emirates (UAE) that hosts a bat colony which is the source of guano deposits and peculiar centimeter-long yellowish stalactites. The mineralogy and geochemistry of these deposits were analyzed using powder X-ray diffraction (XRD), energy dispersive X-ray spectroscopic microanalysis (EDX), scanning electron microscope (SEM), and stable isotope composition (δ13C and δ15N). Urea CO(NH2)2 was found to be the main compound of these stalactites, while allantoin C4H6N4O3 was found to be an accessory urea byproduct. This paper is the first to mention allantoin in a cave environment. We also identified rare sulfate minerals (aphthitalite, alunite) and phosphates that probably correspond to the archerite-biphosphammite series. The occurrence of these rare bat-related minerals is due to the extremely dry conditions in the cave, which accounts for the extraordinary preservation of the guano deposits and allows for the crystallization of these very soluble minerals.Publisher PDFPeer reviewe

Analysis of human resources for health strategies and policies in 5 countries in Sub-Saharan Africa, in response to GFATM AND Pepfar-funded HIV-activities

BACKGROUND: Global Health Initiatives (GHIs), aiming at reducing the impact of specific diseases such as Human Immunodeficiency Virus (HIV), have flourished since 2000. Amongst these, PEPFAR and GFATM have provided a substantial amount of funding to countries affected by HIV, predominantly for delivery of antiretroviral therapy (ARV) and prevention strategies. Since the need for additional human resources for health (HRH) was not initially considered by GHIs, countries, to allow ARV scale-up, implemented short-term HRH strategies, adapted to GHI-funding conditionality. Such strategies differed from one country to another and slowly evolved to long-term HRH policies. The processes and content of HRH policy shifts in 5 countries in Sub-Saharan Africa were examined. METHODS: A multi-country study was conducted from 2007 to 2011 in 5 countries (Angola, Burundi, Lesotho, Mozambique and South Africa), to assess the impact of GHIs on the health system, using a mixed methods design. This paper focuses on the impact of GFATM and PEPFAR on HRH policies. Qualitative data consisted of semi-structured interviews undertaken at national and sub-national levels and analysis of secondary data from national reports. Data were analysed in order to extract countries’ responses to HRH challenges posed by implementation of HIV-related activities. Common themes across the 5 countries were selected and compared in light of each country context. RESULTS: In all countries successful ARV roll-out was observed, despite HRH shortages. This was a result of mostly short-term emergency response by GHI-funded Non-Governmental Organizations (NGOs) and to a lesser extent by governments, consisting of using and increasing available HRH for HIV tasks. As challenges and limits of short-term HRH strategies were revealed and HIV became a chronic disease, the 5 countries slowly implemented mid to long-term HRH strategies, such as formalisation of pilot initiatives, increase in HRH production and mitigation of internal migration of HRH, sometimes in collaboration with GHIs. CONCLUSION: Sustainable HRH strengthening is a complex process, depending mostly on HRH production and retention factors, these factors being country-specific. GHIs could assist in these strategies, provided that they are flexible enough to incorporate country-specific needs in terms of funding, that they coordinate at global-level and minimise conditionality for countries.Department of HE and Training approved lis