The broadband capability of a DSL is dependant on the copper access network. Single Ended Loop Testing (SELT) is the most preferred and economical way in estimating the copper loop topology. The combined use of complementary code based Correlation Time Domain Reflectometry (CTDR) and Frequency Domain Reflectometry (FDR) for accurate loop topology estimation is presented in this paper. The advan...

In this paper a metrological assessment on the accuracy provided by a Time Domain Reflectometry (TDR)based method for the estimation of moisture content of granular materials is proposed. In particular, comparative moisture content measurements are carried out through two different TDR instruments: an inexpensive portable unit and a high-performance unit. The main goals are first to assess a ro...

Time domain reflectometry (TDR) technology is an ideal cable length measurement method. The traveling wave propagation velocity is the key to the measuring accuracy of the TDR cable length measurement system. The cable crimp levels effect on traveling wave propagation velocity is analyzed theoretically, and the corresponding experiment is done. The experimental results are match to the theoreti...

We propose a novel method for the detection of vibrations caused by trains in an optical fiber buried nearby the railway track. Using optical time-domain reflectometry vibrations in the ground caused by different sources can be detected with high accuracy in time and space. While several algorithms have been proposed in the literature for train tracking using OTDR signals they have not been tes...

We present probabilistic models for use in detecting and tracking topics in broadcast news stories. Our information retrieval (IR) models are formally explained. The Topic Detection and Tracking (TDT) initiative is discussed. The application of probabilistic models to the topic detection and tracking tasks is developed, and enhancements are discussed. We discuss four variations of these models,...

The importance of aging electrical wiring and associated faults in aircraft has been highlighted due to the critical effects on the safety of overall systems. Traditional reflectometry methods for the detection and localization of the faults on cable have been achieved in either the time domain or frequency domain only. In this paper, we introduce a new high-performance reflectometry technique ...

A 2D finite-differences time-domain full-wave code is used to simulate the measurements of plasma filaments with fixed frequency O-mode reflectometry. The plasma is modeled by a linear slab plasma plus a Gaussian perturbation propagating in a direction that can vary from poloidal to radial. The plasma background density gradient is chosen in agreement with the steep edge transport barrier of H-...

The problem of fault detection and location in wire networks has gained an increasing importance in the last few years [1]. Wired networks are found in all modern systems, and are used to transmit different signals (control, alarm, etc.). That is why the issue of safe and reliable wiring systems is among the primary concerns of researchers and government agencies today [2]. There are several me...

area of research, dealing with diagnostic and monitoring the health of the electrical transmission networks and find automatically the failures. One of the recently developped (NDT) techniques is Time Domain Reflectometry methods, they are quite efficient for detecting important damages (hard faults), such as short or open-circuits. Interpreting the results obtained with reflectometry instrumen...