Echo is defined as the delayed and attenuated version of the original signal produced by some device, such as a loudspeaker. As a consequence a person listens to a delayed replica of its own voice signal. This is an undesired effect that appears whenever the output signal is fed back into the system’s input and it can be quite disturbing on voice conversations. Echo arises in long distance comm...

The current study assessed the acute effects of pacemaker optimization (PMO) on cardiac function using echocardiographic (ECHO) tissue Doppler imaging (TDI) in the post CRT setting. Data were analyzed from 50 consecutive patients clinically referred for PMO. Patients underwent a sequential ECHO/TDIguided PMO study to determine optimal pacemaker settings. In 34 of 50 patients a change in pacemak...

PURPOSE To compare a three-dimensional Fourier transform (3DFT) gradient-echo pulse sequence with magnetization transfer at a short echo time against standard 3DFT gradient-echo technique in the evaluation of cervical spondylosis, specifically addressing the effects of motion and susceptibility artifacts on the dimensions of the neural foramina and contrast at the cerebrospinal fluid (CSF)-spin...

In order to verify the chaff jamming performance, according to the time-frequency distribution and statistical characteristics of chaff echo, this paper presents a modeling and simulation method of chaff echo based on its mechanism of generation, Also it presents a simulation study of chaff echo signal based on LFM signals. The simulation results indicate that the generated chaff echo of this m...

In the actual communication system, the line echo is a frequent problem, so the line echo canceller is necessary. Traditionally, the cancellers are designed according to line noises based on the Gaussian noise model. However, the noises do not obey the Gaussian distribution; therefore the performances of algorithms decrease, even cannot be used. In order to solve this problem, this paper propos...

Echo is the time delayed version of the original signal. Acoustic echo results from a feedback path set up between the speaker and the microphone in a mobile phone, hands-free phone .Echo can degrade the quality of service in telecommunication. Therefore echo cancellation is an important part of communication systems. A new approach based on the number of coefficients in an adaptive finite impu...

A novel technique of magnetic resonance (MR) imaging, which combines gradient-echo and spin-echo (GRASE) technique, accomplishes T2-weighted multisection imaging in drastically reduced imaging time, currently 24 times faster than spin-echo imaging. The GRASE technique maintains contrast mechanisms, high spatial resolution, and image quality of spin-echo imaging and is compatible with clinical w...

A broadband sonar system and digital camera with strobe lights were mounted on a vertically profiling frame with a depth sensor. The echo strengths and densities of animals within individual mesopelagic boundary community patches were investigated as a function of depth. Time and distance from shore were also investigated. Simultaneous surface echosounder surveys permitted comparison of density...