Creat membership Creat membership
Sign in

Forgot password?

Confirm
  • Forgot password?
    Sign Up
  • Confirm
    Sign In
home > search

Now showing items 1 - 16 of 40

  • Hydrogen permeation characteristics of rolled V85Al10Co5 alloys

    Eric Fleury   Jin-Yoo Suh   Dong-ik Kim   Chan Hoon Jeong   Jung Hoon Park  

    Thin sheets of V 85Al 10Co 5 alloy were produced by a thermo-mechanical treatment consisting in successive hot rolling, cold rolling steps and annealing treatment at high temperature followed by either air cooling or water quenching. Though the values of hydrogen permeability measured for these sheets were significantly reduced as a consequence of the rolling process, the annealing treatment restored almost the hydrogen permeation properties to those of the alloy in the cast condition. EBSD analyses suggested that the post-annealing treatment performed at 1100 degC for 3 min after cold rolling induced a recrystallization of the grains resulting in a preferred orientation along the {002} planes. For the sample annealed and water quenched, the value of the hydrogen flux reached about 45 ml/cm 2.min, which is more than twice the value of the flux obtained for thin foils of Pd alloys tested under identical conditions. [All rights reserved Elsevier].
    Download Collect
  • System and method for discovering surroundings for communicating objects

    The invention relates to a system for determining surroundings in a wireless network, the system including first and second nodes, each node being programmed to periodically detect the nodes located in the surroundings thereof every time period Δ, characterized in that: the first node comprises a transmitter (1) and control means (3) for activating the transmitter (1) for a transmission time ξ less than the time period Δ, the transmitter transmitting an identification signal during the transmission time ξ; the second node comprises a receiver (2) and control means (3) for activating the receiver (2) for a reception time α less than the time period Δ, the receiver (2) listening for the signals from the adjacent nodes during the reception time a, the control means (3) of the second node activating the receiver once per time period Δ.
    Download Collect
  • Route in Mobile WSN and Get Self-deployment for Free

    Kévin Huguenin, Anne-Marie Kermarrec   Eric Fleury  

    We consider a system consisting of a set of mobile sensors. They are disseminated in a region of interest and their mobility is controlled (as opposed to mobility imposed by the entity on which they are embedded). A routing protocol in this context enables any point of the region to be reached starting from any node, regardless of the initial sensor deployment. This operation involves message forwarding and/or sensor motion. In this paper we present Grasp, a GReedy stAteless Routing Protocol for mobile wireless sensor networks (WSN). Grasp is simple and independent from the underlying communication model, but still provides results close to the optimal, with respect to the self-deployment of sensors over a given region. It ensures that (i) routing is always possible in a mobile WSN irrespective of the number of sensors, and (ii) above a given number of sensors in a considered zone the protocol eventually enables the routing to no longer require sensors to move, which yields to self-deployment. With Grasp, sensors autonomously reach a stable full coverage following geometrical patterns. This requires only 1.5 times the optimal number of sensors to cover a region. A theoretical analysis of convergence proves these properties. Simulation results matching the analysis are also presented.
    Download Collect
  • Metallic glass with nanometer-sized pores and method for manufacturing the same

    A nanometer-sized porous metallic glass and a method for manufacturing the same are provided. The porous metallic glass includes Ti (titanium) at 50.0 at % to 70.0 at %, Y (yttrium) at 0.5 at % to 10.0 at %, Al (aluminum) at 10.0 at % to 30.0 at %, Co (cobalt) at 10.0 at % to 30.0 at %, and impurities. Ti +Y+Al+Co+the impurities=100.0 at %.
    Download Collect
  • Latency of Event Reporting in Duty-Cycled Wireless Sensor Networks

    Yu Chen   Eric Fleury  

    We consider duty cycling in sensor networks for time-critical monitoring, where sensors monitor events and send the information to a data collection node (called sink). Latency is considered as the delay elapsed between the time when an event occurs and the time when the sink gets the report. Such networks are different from general purpose ad hoc networks, where latency is defined as the delay elapsed between the time when a source node initiates a packet and the time when the destination node receives the packet. We aim to prolong network lifetime by scheduling periodic sensors’ duty cycles while preserving small latency from events to the sink. In our duty cycle schemes, sensors are grouped into sets; the collaboration between different sets is designed to enable the availability of event reports at active sensors before they reach the sink. Our ideas are simple and achieve desirable properties: the network lifetime is proportional to the number of sets and the performance is comparable to that of non-duty-cycled networks with the same number of active sensors, as shown in our analyses and simulations.
    Download Collect
  • Duplicate Address Detection in Wireless Ad Hoc Networks Using Wireless Nature

    Yu Chen   Eric Fleury  

    We consider duplicate address detection in wireless ad hoc networks under the assumption that addresses are unique in two hops neighborhood. Our approaches are based on the concepts of physical neighborhood views, that is, the information of physically connected nodes, and logical neighborhood views, which are built on neighborhood information propagated in networks. Since neighborhood information is identified by addresses, inconsistency of these two views might occur due to duplicate addresses. It is obvious that consistency of these two views on each node’s neighborhood is necessary for a network to have unique addresses, while the sufficiency depends on the types of information contained in neighborhood views. We investigate different definitions of neighborhood views and show that the traditional neighborhood information, neighboring addresses, is not sufficient for duplication detection, while the wireless nature of ad hoc networks provides useful neighborhood information.
    Download Collect
  • Metallic glass with nanometer-sized pores and method for manufacturing the same

    A nanometer-sized porous metallic glass and a method for manufacturing the same are provided. The porous metallic glass includes Ti (titanium) at 50.0 at % to 70.0 at %, Y (yttrium) at 0.5 at % to 10.0 at %, Al (aluminum) at 10.0 at % to 30.0 at %, Co (cobalt) at 10.0 at % to 30.0 at %, and impurities. Ti+Y+Al+Co+the impurities=100.0 at %.
    Download Collect
  • The toughening of Al–Cu–Fe(-B) quasicrystals by Sn particles

    Eric Fleury   Yu-Chan Kim   Do-Hyung Kim   Do-Hyang Kim   Won-Tae Kim  

    The effect of soft Sn particles on the room temperature mechanical properties of as-cast Al-Cu-Fe(-B) quasicrystalline (QC) matrix composites has been studied by compression and three-point bending tests on notched specimens. Microstructural investigations indicated that the Sn particle size in the as-cast composites increased linearly with the volume fraction. The addition of about 10 vol.% Sn enabled a twofold increase of the strength for the cast Al-Cu-Fe and a threefold increase of the fracture toughness for the cast Al-Cu-Fe-B composites. The enhancement of the strength was attributed to micro-crack impediment and crack bridging mechanisms in the as-cast QC matrix composites with small and large Sn particle sizes, respectively
    Download Collect
  • Distributed Node Location in Clustered Multi-hop Wireless Networks

    Nathalie Mitton   Eric Fleury  

    Wireless routing protocols in MANET are all flat routing protocols and are thus not suitable for large scale or very dense networks because of bandwidth and processing overheads they generate. A common solution to this scalability problem is to gather terminals into clusters and then to apply a hierarchical routing, which means, in most of the literature, using a proactive routing protocol inside the clusters and a reactive one between the clusters. We previously introduced a cluster organization to allow a hierarchical routing and scalability, which have shown very good properties. Nevertheless, it provides a constant number of clusters when the intensity of nodes increases. Therefore we apply a reactive routing protocol inside the clusters and a proactive routing protocol between the clusters. In this way, each cluster has O(1) routes to maintain toward other ones. When applying such a routing policy, a node u also needs to locate its correspondent v in order to pro-actively route toward the cluster owning v. In this paper, we describe our localization scheme based on Distributed Hashed Tables and Interval Routing which takes advantage of the underlying clustering structure. It only requires O(1) memory space size on each node.
    Download Collect
  • Efficient Broadcasting in Self-organizing Multi-hop Wireless Networks

    Nathalie Mitton   Eric Fleury  

    Multi-hop wireless networks (such as ad-hoc or sensor networks) consist of sets of mobile nodes without the support of a pre-existing fixed infrastructure. For the purpose of scalability, ad-hoc and sensor networks may both need to be organized into clusters and require some protocols to perform common global communication patterns and particularly for broadcasting. In a broadcasting task, a source node needs to send the same message to all the nodes in the network. Some desirable properties of a scalable broadcasting are energy and bandwidth efficiency, i.e., message retransmissions should be minimized. In this paper, we propose to take advantage of the characteristics of a previous clustered structure to extend it to an efficient and scalable broadcasting structure. In this way, we build only one structure for both operations (organizing and broadcasting) by applying a distributed clustering algorithm. Our broadcasting improve the number of retransmissions as compared to existing solutions. Keywords: multi-hop wireless networks, self-organization, broadcasting.
    Download Collect
  • Small punch tests on steels for steam power plant (II)

    Eric Fleury   Jeong Soo Ha  

    Analytical formulations using uniaxial tensile stress-strain constitutive behavior have been proposed to model the elastic bending, plastic bending and membrane stretching regimes of small punch load-deflection curves. The equations have been applied on austenitic 12Cr−1Mo steel in the temperature range 25°–600°C and have been verified on ferritic 1Cr–0.5Mo steel at T=25°C. Using these formulations, the room temperature uniaxial tensile stress-strain behavior of the ferritic 2.25Cr−1Mo steel has been determined from the small punch load-deflection response.
    Download Collect
  • Strategies for Path-Based Multicasting in Wormhole-Routed Meshes

    Eric Fleury   Pierre Fraigniaud  

    Multicasting is an information dissemination problem which consists, for a processor of a distributed memory parallel computer, in sending the same message to a subset of processors. In this paper, we propose new multicast algorithms for a mesh network using wormhole routing with a path-based facility. These new algorithms generally perform faster than algorithms previously described in the literature under the same model. We used as the criteria for comparing algorithms the off-line computation time necessary to prepare the multicast and the communication time required to complete the multicast
    Download Collect
  • Cu-based amorphous alloy composition

    Download Collect
  • Documents Diplomatiques Suisses - Diplomatische Dokumente der Schweiz - Documenti Diplomatici Svizzeri. Bd. 16: 9.5. 1945-31.5. 1947by Antoine Fleury; Mauro Cerutti; Michele Coduri; Eric Flury-Dasen

    Review by: Silvia Pfeiffer-Herkenrath  

    Download Collect
  • Effect of grain boundary engineering on the microstructure and mechanical properties of copper containing austenitic stainless steel

    Subhasis Sinha   Dong-Ik Kim   Eric Fleury   Satyam Suwas  

    Abstract The present investigation deals with grain boundary engineering of a modified austenitic stainless steel to obtain a material with enhanced properties. Three types of processing that are generally in agreement with the principles of grain boundary engineering were carried out. The parameters for each of the processing routes were fine-tuned and optimized. The as-processed samples were characterized for microstructure and texture. The influence of processing on properties was estimated by evaluating the room temperature mechanical properties through micro-tensile tests. It was possible to obtain remarkably high fractions of CSL boundaries in certain samples. The results of the micro-tensile tests indicate that the grain boundary engineered samples exhibited higher ductility than the conventionally processed samples. The investigation provides a detailed account of the approach to be adopted for GBE processing of this grade of steel.
    Download Collect
  • Route in Mobile WSN and Get Self-deployment for Free

    Kévin Huguenin   Anne-Marie Kermarrec   Eric Fleury  

    We consider a system composed of a set of mobile sensors; disseminated in a region of interest; which mobility is controlled (as opposed to mobility imposed by the entity on which they are embedded). A routing protocol in this context enables any point of the region to be reached. In this paper we present; Grasp; a GReedy stAteless Routing Protocol for mobile wireless sensor networks (WSN). The strength of Grasp; beyond its simplicity; is that routing enables a free and close to optimal self-deployment of sensors over a given region. Grasp transparently copes with dynamic changes of the region of interest. In addition; Grasp is independent from the underlying communication model. Grasp ensures (i) that routing is always possible in a mobile WSN irrespective of the number of sensors and (ii) above a given number of sensors in a considered zone; the protocol eventually ensures that routing does no longer require sensors to move; thus providing self-deployment. In one dimension; Grasp converges to a full connected-coverage of the region with the minimum required number of sensors in a finite number of steps; ensuring an optimal deployment. In two dimensions; sensors reach autonomously a stable full coverage following geometrical patterns. This requires only 1.5 the optimal number of sensors to cover a region. A theoretical analysis of convergence proves these properties in one and two dimensions. Some simulation results matching the analysis are also presented. Key-words: in ria -0 03 57 24 0; v er si on 1 29 J an 2 00 9 Routage et déploiement spontané dans les réseaux de capteurs mobiles sans fil Résumé : Mots-clés : in ria -0 03 57 24 0; v er si on 1 29 J an 2 00 9 Route in Mobile WSN and Get Self-Deployment for Free 3
    Download Collect
1 2 3

Contact

If you have any feedback, Please follow the official account to submit feedback.

Turn on your phone and scan

Submit Feedback