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Conventional track circuit condition monitoring systems are fixed at the wayside, with each installation reporting on a single track circuit. In this work, we present a custom-built, sensitive, magnetic field detection system, which can be fitted to the underside of a rail vehicle. With this system installed, some characteristics of an operating track circuit can be monitored from the vehicle whilst it is in motion. By using appropriate analysis techniques, it is possible to identify the signatures of equipment relating to audio frequency track circuits, the topic of this work. Analysing the signatures of track circuit equipment demonstrated that there were clear differences between track circuit assets. By building on other research into the behaviours of failing track circuits, and continuing to conduct this research, the authors believe that it is possible, and beneficial, to perform condition monitoring of track circuits from low-cost equipment mounted on the train. Coupling this with advanced analysis techniques will allow predictive maintenance of track circuits with very little capital outlay. [ABSTRACT FROM AUTHOR]

As the foundation of image understanding and analysis, image edge feature extraction of a topic worthy of research in the field of image processing. This paper combines differential evolution and ant colony optimization, uses the combined algorithm in the gray image edge feature extraction, finds the best combination point of these two algorithms and designs the algorithm according to the image edge features. At the beginning, the algorithm of this paper operates the steps of differential evaluation. If the changes of the fitness function value are within the error range, terminate the algorithm, convert the current optimal solution as the matrix distribution of the initial pheromone concentration and operate ant colony optimization. After the optimization is over, output the edge image. This paper compares the advantages and disadvantages as well as the applicability of different algorithms in the gray image edge feature extraction through theoretical analysis and experimental simulation. [ABSTRACT FROM AUTHOR]

Due to a production error, four references were left out of the Application Note by Samuel J. Caprio in the last issue (S. J. Caprio, ?Specifying upper bounds on phase noise in phaselocked oscillators in electronic warfare systems?Part I [Application Notes],? IEEE Microwave Mag., vol. 11, no. 7, pp. 96?112, 2011. [ABSTRACT FROM PUBLISHER]

Enhancing the performance of the DDBs ( Distributed Database system) can be done by speeding up the computation of the data allocation, leading to higher speed allocation decisions and resulting in smaller data redundancy and shorter processing time. This paper deals with an integrated method for grouping the distributed sites into clusters and customizing the database fragments allocation to the clusters and their sites. We design a high speed clustering and allocating method to determine which fragments would be allocated to which cluster and site so as to maintain data availability and a constant systemic reliability, and evaluate the performance achieved by this method and demonstrate its efficiency by means of tabular and graphical representation. We tested our method over different network sites and found it reduces the data transferred between the sites during the execution time, minimizes the communication cost needed for processing applications, and handles the database queries and meets their future needs. [ABSTRACT FROM AUTHOR]

This continuation of my previous application note presents the general mechanism that causes common-mode coupling in mixers. Common mode coupling can increase the noise figure in receivers and/or transmitters. Also presented is a method of calculating the effect of vibration on phase noise in phase-locked oscillators (PLOs). When combined with the techniques presented in Part I, these methods allow an engineer to determine an upper bound on phase noise, and will help engineers decide which PLO is the best for his or her application. [ABSTRACT FROM PUBLISHER]

There is now, more than ever before, a need for technologies that enable the screening of people from a distance. A wide variety of weapons can be easily concealed under clothing and carried into crowded public sites to target national infrastructure, spread fear, and infl ict mass murder and casualties. The most feared and devastating terrorist weapon is the suicide bomb or person borne improvised explosive device (PBIED). Such devices are relatively simple to conceal on the body, and successful detection is required at considerable distance or stand-off range before the bomber reaches the target area. [ABSTRACT FROM PUBLISHER]