A real-time obstacle detection algorithm for the visually impaired using binocular camera

In this paper, a real-time depth-data based obstacle detection to assist the visually impaired people in avoiding obstacles independently is presented. Depth data obtained by the binocular camera, is analyzed to detect obstacles. With the help of the proposed method, the distance between the binocular camera and the obstacle can be calculated with the speed of 30fps. Our method further allows the computation of the position and the size of the obstacle. The proposed algorithm has been extensively tested on both real images and public Laundry data-set. Experimental results demonstrate that the proposed method is not only able to detect the obstacles correctly but it is also fast, efficient and stable

Preseismic electromagnetic signals in terms of complexity

There is a recent thesis in the literature that an important organization of a physical system precedes a catastrophic event. In this context, one can search for signatures that imply the transition from a normal state to a main catastrophic event (e.g., earthquake). Experimental techniques are thus useful in corroborating theories from observed data. For example, recent results indicate that preseismic electromagnetic time series contain information characteristic of an ensuing earthquake event. Hereby, we attempt to demonstrate that an easily computable complexity measure, such as T -complexity or approximate entropy, gives evidence of state changes leading to the point of global instability. The appearance of a precatastrophic state is characterized by significant lower complexity in terms of T -complexity and approximate entropy. The present study confirms the conclusions of previous works based on an independent linear fractal spectral analysis. This convergence between nonlinear and linear analysis provides a more reliable detection concerning the emergence of the last phase of the earthquake preparation process. More precisely, we claim that our results suggest an important principle: significant complexity decrease and accession of persistency in electromagnetic (EM) time series can be confirmed at the tail of the preseismic EM emission, which could be used as diagnostic tools for the Earth's impending crust failure. Direct laboratory and field experimental data as well as theoretical arguments support the conclusions of the present analysis. © 2006 The American Physical Society