Utilization of matched pulses to improve fault detection in wire networks

International audienceA new concept to fault detection in wire networks, based on the properties of time reversal, is presented. The method, called the Matched Pulse approach (MP), propose to adapt the testing signal to the analyzed network, instead of using a predefined signal, as opposed to existing reflectometry methods. Through mathematical study and numerical simulations, we show the benefits of this technique. A physical interpretation is also presented to better understand the proposed approach

Experimental Evaluation of the Inverse Scattering Method for Electrical Cable Fault Diagnosis

International audienceRecently published theoretic and experimental results have shown the ability of inverse scattering-based methods to detect and to locate soft faults in electric cables, in particular, faults implying smooth spatial variations of cable characteristic parameters. The purpose of the present paper is to further experimentally evaluate the inverse scattering method for retrieving spatially distributed characteristic impedance from reflectometry measurements. With high quality coaxial cables connected in parallel, composite cables of piecewise constant characteristic impedance profiles are built in order to evaluate the accuracy of the inverse scattering method and its robustness in the presence of impedance discontinuities

Experimental validation of the inverse scattering method for distributed characteristic impedance estimation

International audience— Recently published theoretic results and numerical simulations have shown the ability of inverse scattering-based methods to diagnose soft faults in electric cables, in particular, faults implying smooth spatial variations of cable characteristic parameters. The purpose of the present paper is to report laboratory experiments confirming the ability of the inverse scattering method for retrieving spatially distributed characteristic impedance from reflectometry measurements. Various smooth or stepped spatial variations of characteristic impedance profiles are tested. The tested electric cables are CAN unshielded twisted pairs used in trucks and coaxial cables

NASA SBIR abstracts of 1990 phase 1 projects

The research objectives of the 280 projects placed under contract in the National Aeronautics and Space Administration (NASA) 1990 Small Business Innovation Research (SBIR) Phase 1 program are described. The basic document consists of edited, non-proprietary abstracts of the winning proposals submitted by small businesses in response to NASA's 1990 SBIR Phase 1 Program Solicitation. The abstracts are presented under the 15 technical topics within which Phase 1 proposals were solicited. Each project was assigned a sequential identifying number from 001 to 280, in order of its appearance in the body of the report. The document also includes Appendixes to provide additional information about the SBIR program and permit cross-reference in the 1990 Phase 1 projects by company name, location by state, principal investigator, NASA field center responsible for management of each project, and NASA contract number

System data communication structures for active-control transport aircraft, volume 2

The application of communication structures to advanced transport aircraft are addressed. First, a set of avionic functional requirements is established, and a baseline set of avionics equipment is defined that will meet the requirements. Three alternative configurations for this equipment are then identified that represent the evolution toward more dispersed systems. Candidate communication structures are proposed for each system configuration, and these are compared using trade off analyses; these analyses emphasize reliability but also address complexity. Multiplex buses are recognized as the likely near term choice with mesh networks being desirable for advanced, highly dispersed systems

Passive In-Band Network Telemetry Systems: The Potential of Programmable Data Plane on Network-Wide Telemetry

In the last few years, the emergence of Programmable Data Planes and the appearance of programming protocol-independent languages such as P4 have offered powerful tools to define new network protocols, as well as to redesign existing network applications and systems. Network telemetry is one of the main areas of interest identified by the P4 Application Working Group. The collection of network-wide, fine-grained network information in real-time is a critical requirement for the design of useful and adequate monitoring tools that can be integrated into complex Operations, Administration Maintenance applications. Recent research has focused on the definition and implementation of in-band monitoring systems, where specifically dedicated monitoring packets are not required. Even though the In-Band Network Telemetry specification proposed by the P4 Language Consortium is the starting point of many of the in-band monitoring systems, this is not the only alternative. Therefore, in this work, we will describe and compare other P4-based in-band passive telemetry proposals.This work was supported by the Research State Agency (RSA)/European Regional Development Funds (ERDF) through the European Union Project under Grant TEC-2016-76465-C2-1-R (AIM)

Deep Space Network information system architecture study

The purpose of this article is to describe an architecture for the Deep Space Network (DSN) information system in the years 2000-2010 and to provide guidelines for its evolution during the 1990s. The study scope is defined to be from the front-end areas at the antennas to the end users (spacecraft teams, principal investigators, archival storage systems, and non-NASA partners). The architectural vision provides guidance for major DSN implementation efforts during the next decade. A strong motivation for the study is an expected dramatic improvement in information-systems technologies, such as the following: computer processing, automation technology (including knowledge-based systems), networking and data transport, software and hardware engineering, and human-interface technology. The proposed Ground Information System has the following major features: unified architecture from the front-end area to the end user; open-systems standards to achieve interoperability; DSN production of level 0 data; delivery of level 0 data from the Deep Space Communications Complex, if desired; dedicated telemetry processors for each receiver; security against unauthorized access and errors; and highly automated monitor and control

Measurements, Models, Systems and Design

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