A local criteria for the existence of an accelerated frame of reference is found. An accelerated frame of reference could exist in all regions where a non-null (non-isotropic) vector field does not degenerate in a null (isotropic) vector field.

Given a video sequence decompressed from a compressed video sequence associated with motion vector information for each image frame, this short note presents an efficient predictive watershed-based video segmentation algorithm using motion vectors. The proposed algorithm has much computation-saving merit since the next frame can inherit the segmented results of the current frame according to th...

The MPEG-2 video compression standard is commonly used in real-time video transmission. In real-time video transmission, a little bit error can cause huge data lost in the video sequence. The errors and data loss degrade the quality of video. The error concealment method is useful to overcome the errors in the broken slice of MPEG-2. In this paper, we present an efficient error concealment algo...

In hybrid simulation, the structure is divided into numerical and physical substructures to achieve more accurate responses in comparison to a full computational analysis. As a consequence of the lack of test facilities and actuators, and the budget limitation, only a few substructures can be modeled experimentally, whereas the others have to be modeled numerically. In this paper, a new hybrid ...

In classical block-based video coding, one motion vector per image block is used to improve the prediction of the frame to be coded. These motion vectors and the resulting motion-compensated difference frame must be encoded with bits. All motion vectors are encoded with the same fixed accuracy, typically 1 or 1/2 pixel accuracy, but the best motion vector accuracies are not known. In this paper...

Abstract Propagation of medium-scale gravity waves (GWs) in the thermosphere/ionosphere is observed remotely, using multi-frequency and multi-point continuous Doppler sounding system located western part Czechia. Reflection heights radio are determined from a nearby ionosonde. Phase velocity vectors GWs calculated time/phase delays between signals corresponding to different transmitter–receiver...

This The Permanent Magnet Synchronous Motors (PMSM) are used for medium power applications and preferred over conventional motors like Induction and Synchronous motors due its superior performance, efficiency and controllability. Normal voltage source inverters are suitable only for three phase drives. Cascaded multi-level inverters are used to improve the power quality. The Hexagram inverter h...

In the field of topology optimization, homogenization approach has been revived as an important alternative to established, density-based methods. Homogenization can represent microstructures at length scales decoupled from resolution computational grid. The optimal microstructure for a single load case is orthogonal rank-3 laminate. Initially, we investigate where singularities occur in lamina...

i-vector modeling techniques have been successfully used for speaker clustering task recently. In this work, we propose the extraction of i-vectors from shortand long-term speech features, and the fusion of their PLDA scores within the frame of speaker diarization. Two sets of i-vectors are first extracted from short-term spectral and long-term voice-quality, prosodic and glottal to noise excit...