52 research outputs found
On re-normalization in the theory of weak turbulence in plasmas
The paper compares the methods of re-normalization introduced by the Dupree—Weinstock theory of turbulence with those in the theories of Kadomtsev, Rudakov and Tsytovich. It is shown to what extent they are equivalen
Enhancement of CASSI by a zero-order image employing a single detector
Coded aperture snapshot spectral imaging (CASSI) makes it possible to recover
3D hyperspectral data from a single 2D image. However, the reconstruction
problem is severely underdetermined and efforts to improve the compression
ratio typically make the imaging system more complex and cause a significant
loss of incoming light intensity. In this paper, we propose a novel approach to
CASSI which enables capturing both spectrally sheared and integrated image of a
scene with a single camera. We performed hyperspectral imaging of three
different testing scenes in the spectral range of 500-900 nm. We demonstrate
the prominent effect of using the non-diffracted image on the reconstruction of
data from our camera. The use of the spectrally integrated image improves the
reconstruction quality and we observed an approx. fivefold reduction in
reconstruction time
Differential Coded Aperture Single-Snapshot Spectral Imaging
We propose a novel concept of differential coded aperture snapshot spectral
imaging (D-CASSI) technique exploiting the benefits of using {-1,+1} random
mask, which is demonstrated by a broadband single-snapshot hyperspectral camera
using compressed sensing. To double the information, we encode the image by two
complementary random masks, which proved to be superior to two independent
patterns. We utilize dispersed and non-dispersed encoded images captured in
parallel onto a single detector. We explored several different approaches to
processing the measured data, which demonstrates significant improvement in
retrieving complex hyperspectral scenes. The experiments were completed by
simulations in order to quantify the reconstruction fidelity. The concept of
differential CASSI could be easily implemented also by multi-snapshot CASSI
without any need for optical system modification
Catheter-based renal denervation versus intensified medical treatment in patients with resistant hypertension: Rationale and design of a multicenter randomized study—PRAGUE-15
AbstractCatheter-based renal denervation (RDN) was considered as a promising method for treatment of resistant hypertension and was increasingly being used worldwide. However, there are equivocal results from only two randomized trials studying the effect of such intervention. Thus, additional data from properly designed long-term comparative trials are needed. The PRAGUE-15 trial is designed as an open, prospective, randomized multicenter trial comparing RDN versus intensified medical treatment in patients with resistant hypertension. Patients randomized to the medical treatment group will receive spironolactone in the absence of contraindications. The primary endpoint will be changes in systolic and diastolic pressure during ambulatory blood pressure monitoring (ABPM) from baseline to 6 months. Herein, we describe the trial design and methodology. The strengths of the trial include ABPM (as the objective endpoint), independent outcomes assessment, and therapeutic use of spironolactone
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