This paper proposes a novel vector field navigation method by using the velocity vector of a robot to avoid obstacles in dynamic environment. Shifting vector and virtual obstacle are proposed to derive the center of repulsive field which makes the robot move away from the obstacle: The shifting vector is derived from the velocity vector of the robot and the obstacle and the virtual obstacle is ...

Recent progress in bistatic radar techniques can be used to improve performances of classical monostatic radar. A prominent limitation of coherent radar is its inability to measure the complete velocity vector (magnitude and direction) of a detected target. A single coherent detection can provide range-rate only. At least two detections, separated in time, are needed to estimate the target’s ve...

Laser speckle flowmetry suffers from a debated quantitative relationship with blood flow, velocity or tissue perfusion and a lack of calibration of the inverse relationship 1/τc = αV between decorrelation time (τc) and flow velocity (V). Using a modified microcirculation imager, we experimentally investigate on the influence of the optical properties of scatterers on α in vitro and in vivo. We ...

Laser speckle flowmetry suffers from a debated quantitative relationship with blood flow, velocity or tissue perfusion and a lack of calibration of the inverse relationship 1/τc = αV between decorrelation time (τc) and flow velocity (V). Using a modified microcirculation imager, we experimentally investigate on the influence of the optical properties of scatterers on α in vitro and in vivo. We ...

MRI techniques provide a non-invasive method for the highly accurate anatomic depiction of the heart and vessels. In addition, the intrinsic sensitivity of MRI to flow, motion and diffusion offers the possibility to acquire spatially registered functional information simultaneously with the morphological data within a single experiment [1-13, 16-19, 31, 36, 38]. Characterizations of the dynamic...

Laser speckle flowmetry suffers from a debated quantitative relationship with blood flow, velocity or tissue perfusion and a lack of calibration of the inverse relationship 1/τc = αV between decorrelation time (τc) and flow velocity (V). Using a modified microcirculation imager, we experimentally investigate on the influence of the optical properties of scatterers on α in vitro and in vivo. We ...

A study of the photodissociation dynamics of NO2 in the 200–205 nm region using resonance enhanced multiphoton ionization (REMPI) in conjunction with the velocity map imaging technique is presented. We chose this region because it allowed the use of a single laser to photodissociate the NO2 molecule and probe both the O(D2) fragment using (2+1) REMPI via the 3p ′1P1 state at 2× 205.47 nm and th...

Laser speckle flowmetry suffers from a debated quantitative relationship with blood flow, velocity or tissue perfusion and a lack of calibration of the inverse relationship 1/τc = αV between decorrelation time (τc) and flow velocity (V). Using a modified microcirculation imager, we experimentally investigate on the influence of the optical properties of scatterers on α in vitro and in vivo. We ...