Topic Detection and Tracking (TDT) refers to automatic techniques for locating topically related material in streams of data such as newswire and broadcast news. DARPA-sponsored research has made enormous progress during the past three years, and the tasks have been made progressively more difficult and realistic. Well-designed corpora and objective performance evaluations have enabled this suc...

Mechanical details as well as electrical models of FDR (frequency domain reflectometry) sensors for the measurement of the complex dielectric permittivity of porous materials are presented. The sensors are formed from two stainless steel parallel waveguides of various lengths. Using the data from VNA (vector network analyzer) with the connected FDR sensor and selected models of the applied sens...

Measurement and control of the fluid parameters play a very important role in industry applications such as in the petrochemical industrial processing, where there is an increasing demand for real-time determination of dielectric parameters in relation to the product quality. Furthermore, in such a context, additional stringent requirements frequently deal with the spatial localization of non-m...

Unlike terrestrial Wireless Sensor Networks (WSNs), communication between buried nodes in WUSNs happens through the ground. Due to the complexity of soil, accurate estimation of the underground signal attenuation is challenging. Existing path loss models mainly rely on semi-empirical and empirical mixing models for calculating the dielectric properties of the soil. In this paper, two existing m...

Passive optical network (PON) systems based on optical splitters provide low-cost optical access by sharing equipment cost between subscribers. However, it was difficult to monitor a drop fiber section from the central office using reflectometry because of the overlap of reflectometry results derived from multiple drop fiber branches. This difficulty in monitoring has added maintenance costs be...

Topic Detection and Tracking (TDT) refers to automatic techniques for finding topically related material in streams of data (e.g., newswire and broadcast news). Work on TDT began about a year ago, is now expanding, and will be a regular feature at future Broadcast News workshops.

Efficient reconstruction of dispersive dielectric profiles using time domain reflectometry (TDR) P. Leidenberger, B. Oswald, and K. Roth Institute of Environmental Physics, University of Heidelberg, Heidelberg, Germany Received: 29 July 2005 – Accepted: 5 August 2005 – Published: 15 August 2005 Correspondence to: B. Oswald ([email protected]) © 2005 Author(s). This work is l...

Multi-channel Analysis of Surface Waves (MASW) is a seismic wave propagation method which involves the measurement of Rayleigh waves propagating along the surface of a medium. The method is non-intrusive, fast and practical and it has been successfully utilized for the in-situ evaluation of shear modulus and layer thicknesses of soils and, more recently, pavement systems. The method is also wid...