In order to enhance the perception of indoor and unfamiliar environments for the blind and visually-impaired, we introduce the PERCEPT system that supports a number of unique features such as: a) Low deployment and maintenance cost; b) Scalability, i.e. we can deploy the system in very large buildings; c) An on-demand system that does not overwhelm the user, as it offers small amounts of information on demand; and d) Portability and ease-of-use, i.e., the custom handheld device carried by the user is compact and instructions are received audibly.

Many researchers have proposed various predictor equations to determine the PPV (Peak particle velocity) which is the function of distance and maximum safe charge per delay. When the maximum safe charge per delay is calculated by different predictors its values vary because these predictors are formulated on different bases with limited observations. In this paper, an equation has been proposed for estimation of the maximum safe charge per delay and its performance has been compared with other predictors. The proposed predictor is the function of PPV and distance. Results were well correlated and near to the observed value. The maximum charge per delay has been calculated by all predictors and compared with the proposed one. The coefficient of correlation was found to be high for the proposed predictor. This may be give better prediction of safe charge as compared to other predictors for different rock litho units.

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In this paper we study the numerical modeling of the complex anthropomorphic human phantoms, aimed for microwave imaging, using the WIPL-D software. By comparing various models, we investigate the influence of the geometrical simplification of the phantom on the accuracy of the electromagnetic response of the antennas in the vicinity of the phantom. By controlling the geometrical deviation of the simplified model with respect to the original model, we show that it is possible to reduce the simulation resources for one to two orders of magnitude while preserving the precision of the electromagnetic analysis.