A novel algorithm for high sensitivity in measuring surface variation based on volume holography

Introduction: Ablation of ventricular tachycardia (VT) substrate in patient at risk for VT in the setting of ischemic heart disease is a technically challenging procedure. We thought to evaluate a novel algorithm used to automatically identify target electrograms. Methods: 16 consecutive patients (70±10 years of age, 90% male, 34±18% LV EF) had 20 ablations for ischemic VT using CARTO 3 mapping system over 2 years. Left ventricular (LV) substrate was mapped during right ventricular (RV) apical stimulation. Navistar Thermocool 3.5 mm irrigated tip catheters were used in all patients. A novel algorithm counting the number of electrogram deflections (NOD) crossing the 0.05mV noise threshold and duration of time from first to last such deflection during the window of interest (total fractionation time, TFT) was applied to all acquired maps after ablation was complete. Snapshots of 200 electrograms representing the high and low end of TFT and NOD values were presented to a group of 8 electrophysiologists experienced in VT ablation who were asked to select electrograms they would target for substrate ablation. The diagnostic accuracy of TFT and NOD values was then analysed. Results: Across the range of TFT values (0.0-281.0 ms), a cut-off value of 49.0 ms (81.6% sensitivity, 57% specificity) was established as an optimal indicator of an ablation target. Area under the curve for TFT was 0.675 (95% CI: 0.59-0.75, p=0.001). For NOD values (0.0-70.0 deflections), a cut off of 4.5 deflections (88.0% Sensitivity, 57 % specificity) was established as an optimal indicator of an ablation target. The area under the curve for NOD yielded an area of 0.75 (95% CI: 0.68-0.82, P=0.001). For TFT-NOD product as a variable, a cut-off value of 64 (91.0% Sensitivity, 52.4 % specificity) an optimal indicator of an ablation target. The Area under the curve for NOD and TFT multiple was 0.72 (95% CI: 0.65-0.80, P=0.001). Conclusion: A novel algorithm may be able to automatically classify LV substrate during mapping and ablation of ischemic VT with high sensitivity and acceptable specificity.

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A High-Sensitivity Acquisition Algorithm for BeiDou Signals with NH Code

Journal of Navigation ◽

10.1017/s0373463319000304 ◽

2019 ◽

Vol 72 (06) ◽

pp. 1550-1564

Author(s):

Rongbing Li ◽

Zhifeng Han ◽

Jianye Liu ◽

Yi Wang

Keyword(s):

Monte Carlo ◽

Traditional Method ◽

High Sensitivity ◽

Real Data ◽

Search Algorithms ◽

Integration Time ◽

Test Results ◽

Zero Padding ◽

Differential Correlation ◽

Novel Algorithm

BeiDou signals are modulated with a Neumann-Hofman (NH) code of 1 kbps. The frequent bit transitions lead to a sensitivity attenuation of classic acquisition algorithms. In order to increase acquisition sensitivity for weak BeiDou signals, a novel algorithm based on modified zero-padding and differential correlation is proposed. First, a zero-padding method is used to weaken the effect of NH code. Second, the differential coherent delay time is modified to 20 ms to remove the influence of data bit transitions. The integration time is extended to 10 ms to increase acquisition sensitivity. Finally, Monte Carlo simulations and real data tests are conducted to analyse the performance of the proposed algorithm. Simulated results show that the proposed acquisition algorithm outperforms traditional algorithms under a Carrier-to-Noise ratio (C/N0s) of 20~38 dB-Hz. The sensitivity of the proposed algorithm is about 10dB higher than traditional 6 ms repeated search algorithms. Real data test results show that the proposed algorithm outperforms the traditional method with weak signals. This algorithm can remove the effect of NH code and effectively increase the acquisition sensitivity. The proposed algorithm is suitable for acquisition of weak BeiDou signals.

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A Technique for the Measurement of Hot Spots and Isotherm Profiles at the Surfaces of the Elements of Hybrid Microcircuits

ElectroComponent Science and Technology ◽

10.1155/apec.6.177 ◽

1980 ◽

Vol 6 (3-4) ◽

pp. 177-183 ◽

Cited By ~ 6

Author(s):

F. N. Sinnadurai

Keyword(s):

Spatial Resolution ◽

Hot Spots ◽

Visual Information ◽

Simple Technique ◽

High Sensitivity ◽

Alternative Methods ◽

Design Evaluation ◽

Supportive Role ◽

Measuring Surface ◽

Better Than

A simple technique for measuring surface temperatures with high sensitivity and spatial resolution, which is particularly useful for examining temperature distributions of microcircuits, is described. The invention exploits the well-defined “Isotropic-point” transitions of nematic liquid crystals from optical birefringence to anisotropy, using a polarising microscope to detect temperatures in microscopic areas. Thus hot spots appear black against a bright background. The temperature sensitivity is better than 0.5℃ and the spatial resolution better than 5 microns. The technique has distinct advantages over alternative methods of measuring microcircuit temperatures. Examples of applications in support of design evaluation and fault diagnosis of monolithic circuits illustrate the benefits of visual information obtained. The ready application of the technique to the large planar areas of thick film resistors has enabled the location of hot spots – confirming their occurrence at the end of laser cuts – and the measurement of thermal resistances of resistors either singly or in arrays – showing that substantial heat conduction through the substrate can outweigh local non-uniformities in dissipation. Applications extend beyond the supportive role to reliability evaluation illustrated in this paper.

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Cryptographic hash functions for image processing

10.32920/ryerson.14668392.v1 ◽

2021 ◽

Author(s):

Shafaq Iftikhar

Keyword(s):

Image Processing ◽

Hash Function ◽

Hash Functions ◽

High Sensitivity ◽

High Complexity ◽

Sole Purpose ◽

High Security ◽

Using Data ◽

Cryptographic Hash Functions ◽

Novel Algorithm

In this paper, a novel algorithm based on hash function for image cryptography is proposed. In this algorithm, the key idea is to encrypt half of the image using data from the second half of the image and then apply it to each other. This scheme can achieve high sensitivity, high complexity, and high security. The sole purpose is to improve the image entropy.

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Automatic classification of leukocytes

Journal of Automatic Control ◽

10.2298/jac0601029m ◽

2006 ◽

Vol 16 (1) ◽

pp. 29-32 ◽

Cited By ~ 6

Author(s):

Stanislav Mircic ◽

Nikola Jorgovanovic

Keyword(s):

Classification Accuracy ◽

Blood Count ◽

Blood Smear ◽

High Sensitivity ◽

Direct Analysis ◽

Differential Blood Count ◽

Additional Increase ◽

Blood Smear Image ◽

Novel Algorithm

This paper presents a novel algorithm for the automatic compilation of differential blood count (DBC), which is based on the direct analysis of a blood smear image and artificial neural networks. The results of the algorithm testing show high sensitivity of the algorithm in leukocyte detection and classification accuracy of 86%. Also, the algorithm enables the detection of potentially falsely classified leukocytes and in that way, with the help of a hematological expert, enables additional increase in the DBC compilation quality.

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Cryptographic hash functions for image processing

10.32920/ryerson.14668392 ◽

2021 ◽

Author(s):

Shafaq Iftikhar

Keyword(s):

Image Processing ◽

Hash Function ◽

Hash Functions ◽

High Sensitivity ◽

High Complexity ◽

Sole Purpose ◽

High Security ◽

Using Data ◽

Cryptographic Hash Functions ◽

Novel Algorithm

In this paper, a novel algorithm based on hash function for image cryptography is proposed. In this algorithm, the key idea is to encrypt half of the image using data from the second half of the image and then apply it to each other. This scheme can achieve high sensitivity, high complexity, and high security. The sole purpose is to improve the image entropy.

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Radio Measurements of Coronal Magnetic Fields

International Astronomical Union Colloquium ◽

10.1017/s0252921100024933 ◽

1994 ◽

Vol 144 ◽

pp. 21-28 ◽

Cited By ~ 4

Author(s):

G. B. Gelfreikh

Keyword(s):

Magnetic Field ◽

Magnetic Fields ◽

Solar Corona ◽

Active Regions ◽

High Sensitivity ◽

Coronal Magnetic Field ◽

Transverse Magnetic ◽

Radio Sources ◽

Radio Waves ◽

Solar Active Regions

AbstractA review of methods of measuring magnetic fields in the solar corona using spectral-polarization observations at microwaves with high spatial resolution is presented. The methods are based on the theory of thermal bremsstrahlung, thermal cyclotron emission, propagation of radio waves in quasi-transverse magnetic field and Faraday rotation of the plane of polarization. The most explicit program of measurements of magnetic fields in the atmosphere of solar active regions has been carried out using radio observations performed on the large reflector radio telescope of the Russian Academy of Sciences — RATAN-600. This proved possible due to good wavelength coverage, multichannel spectrographs observations and high sensitivity to polarization of the instrument. Besides direct measurements of the strength of the magnetic fields in some cases the peculiar parameters of radio sources, such as very steep spectra and high brightness temperatures provide some information on a very complicated local structure of the coronal magnetic field. Of special interest are the results found from combined RATAN-600 and large antennas of aperture synthesis (VLA and WSRT), the latter giving more detailed information on twodimensional structure of radio sources. The bulk of the data obtained allows us to investigate themagnetospheresof the solar active regions as the space in the solar corona where the structures and physical processes are controlled both by the photospheric/underphotospheric currents and surrounding “quiet” corona.

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Backscattered Electron Imaging of GaAs/AlGaAs Super Lattice Structures with an Ultra-High- Resolution SEM

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100103103 ◽

1988 ◽

Vol 46 ◽

pp. 204-205

Author(s):

Kazumichi Ogura ◽

Michael M. Kersker

Keyword(s):

High Resolution ◽

Layer Structure ◽

High Sensitivity ◽

Beam Current ◽

Electron Beam Current ◽

Lattice Structures ◽

Super Lattice ◽

Different Types ◽

Backscattered Electron ◽

Electron Imaging

Backscattered electron (BE) images of GaAs/AlGaAs super lattice structures were observed with an ultra high resolution (UHR) SEM JSM-890 with an ultra high sensitivity BE detector. Three different types of super lattice structures of GaAs/AlGaAs were examined. Each GaAs/AlGaAs wafer was cleaved by a razor after it was heated for approximately 1 minute and its crosssectional plane was observed.First, a multi-layer structure of GaAs (100nm)/AlGaAs (lOOnm) where A1 content was successively changed from 0.4 to 0.03 was observed. Figures 1 (a) and (b) are BE images taken at an accelerating voltage of 15kV with an electron beam current of 20pA. Figure 1 (c) is a sketch of this multi-layer structure corresponding to the BE images. The various layers are clearly observed. The differences in A1 content between A1 0.35 Ga 0.65 As, A1 0.4 Ga 0.6 As, and A1 0.31 Ga 0.69 As were clearly observed in the contrast of the BE image.

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An x-ray microprobe based upon a close-coupled focal-spot / glass capillary arrangement

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100133424 ◽

1992 ◽

Vol 50 (2) ◽

pp. 1758-1759

Author(s):

D. A. Carpenter ◽

M. A. Taylor

Keyword(s):

Imaging Techniques ◽

Fluorescence Analysis ◽

High Sensitivity ◽

Specimen Preparation ◽

X Rays ◽

Glass Capillary ◽

Close Coupling ◽

X Ray ◽

Point To Point ◽

Beam Damage

The development of intense sources of x rays has led to renewed interest in the use of microbeams of x rays in x-ray fluorescence analysis. Sparks pointed out that the use of x rays as a probe offered the advantages of high sensitivity, low detection limits, low beam damage, and large penetration depths with minimal specimen preparation or perturbation. In addition, the option of air operation provided special advantages for examination of hydrated systems or for nondestructive microanalysis of large specimens.The disadvantages of synchrotron sources prompted the development of laboratory-based instrumentation with various schemes to maximize the beam flux while maintaining small point-to-point resolution. Nichols and Ryon developed a microprobe using a rotating anode source and a modified microdiffractometer. Cross and Wherry showed that by close-coupling the x-ray source, specimen, and detector, good intensities could be obtained for beam sizes between 30 and 100μm. More importantly, both groups combined specimen scanning with modern imaging techniques for rapid element mapping.

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Ultrastructural identification of three types of sensory setae on copepod antennae

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100141159 ◽

1995 ◽

Vol 53 ◽

pp. 956-957

Author(s):

T. M. Weatherby ◽

P.H. Lenz

Keyword(s):

Phase Locking ◽

Membrane Surface ◽

Reaction Times ◽

High Sensitivity ◽

Structural Features ◽

Calanoid Copepods ◽

Marine Food Webs ◽

Dendritic Membrane ◽

Ultrastructural Characterization

Crustaceans, as well as other arthropods, are covered with sensory setae and hairs, including mechanoand chemosensory sensillae with a ciliary origin. Calanoid copepods are small planktonic crustaceans forming a major link in marine food webs. In conjunction with behavioral and physiological studies of the antennae of calanoids, we undertook the ultrastructural characterization of sensory setae on the antennae of Pleuromamma xiphias.Distal mechanoreceptive setae exhibit exceptional behavioral and physiological performance characteristics: high sensitivity (<10 nm displacements), fast reaction times (<1 msec latency) and phase locking to high frequencies (1-2 kHz). Unusual structural features of the mechanoreceptors are likely to be related to their physiological sensitivity. These features include a large number (up to 3000) of microtubules in each sensory cell dendrite, arising from or anchored to electron dense rods associated with the ciliary basal body microtubule doublets. The microtubules are arranged in a regular array, with bridges between and within rows. These bundles of microtubules extend far into each mechanoreceptive seta and terminate in a staggered fashion along the dendritic membrane, contacting a large membrane surface area and providing a large potential site of mechanotransduction.

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