Preventing forgery attacks in computational ghostimaging or disabling ghost imaging in a"spatiotemporal" scattering medium with weightedmultiplicative signals

2021 ◽  
Author(s):  
Zhiyuan Ye ◽  
Tianyu Huang ◽  
Jingyu Pan ◽  
Tiantian Zhang ◽  
Yi Cui ◽  
...  
Keyword(s):  
Ghost Imaging ◽  
Scattering Medium

Positive influence of the scattering medium on reflective ghost imaging

2019 ◽  
Vol 7 (12) ◽  
pp. 1468 ◽  
Author(s):  
Qin Fu ◽  
Yanfeng Bai ◽  
Xianwei Huang ◽  
Suqin Nan ◽  
Peiyi Xie ◽  
...  
Keyword(s):  
Positive Influence ◽  
Ghost Imaging ◽  
Scattering Medium

Computational Ghost Imaging Using a Dynamic Scattering Medium by the Point-by-Point Compensation Method

2020 ◽  
Vol 57 (20) ◽  
pp. 201106
Author(s):  
胡洋頔 Hu Yangdi ◽  
程正东 Cheng Zhengdong ◽  
梁振宇 Liang Zhenyu ◽  
翟翔 Zhai Xiang
Keyword(s):  
Compensation Method ◽  
Ghost Imaging ◽  
Scattering Medium ◽  
Dynamic Scattering

Lensless ghost imaging through the strongly scattering medium

2016 ◽  
Vol 25 (2) ◽  
pp. 024202 ◽  
Author(s):  
Zhe Yang ◽  
Lianjie Zhao ◽  
Xueliang Zhao ◽  
Wei Qin ◽  
Junlin Li
Keyword(s):  
Ghost Imaging ◽  
Scattering Medium

Imaging quality improvement of ghost imaging in scattering medium based on Hadamard modulated light field

2020 ◽  
Vol 59 (27) ◽  
pp. 8472
Author(s):  
Zhujun Gao ◽  
Jianhua Yin ◽  
Yanfeng Bai ◽  
Xiquan Fu
Keyword(s):  
Quality Improvement ◽  
Light Field ◽  
Ghost Imaging ◽  
Scattering Medium ◽  
Imaging Quality ◽  
Modulated Light

Study of photon propagation in a liquid scattering medium

1997 ◽  
Vol 94 ◽  
pp. 251-256 ◽  
Author(s):  
S Marengo ◽  
C Pépin ◽  
D Houde
Keyword(s):  
Scattering Medium ◽  
Photon Propagation

scholarly journals Experimental demonstration of spectral domain computational ghost imaging

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Piotr Ryczkowski ◽  
Caroline G. Amiot ◽  
John M. Dudley ◽  
Goëry Genty
Keyword(s):  
Signal To Noise Ratio ◽  
Michelson Interferometer ◽  
Spectral Domain ◽  
Proof Of Concept ◽  
Ghost Imaging ◽  
Spectral Measurements ◽  
Spectral Filter ◽  
Wavelength Division ◽  
Spectral Encoding ◽  
Light Effects

AbstractWe demonstrate computational spectral-domain ghost imaging by encoding complementary Fourier patterns directly onto the spectrum of a superluminescent laser diode using a programmable spectral filter. Spectral encoding before the object enables uniform spectral illumination across the beam profile, removing the need for light collection optics and yielding increased signal-to-noise ratio. In addition, the use of complementary Fourier patterns allows reduction of deleterious of parasitic light effects. As a proof-of-concept, we measure the wavelength-dependent transmission of a Michelson interferometer and a wavelength-division multiplexer. Our results open new perspectives for remote broadband spectral measurements.

scholarly journals Development and characterization of an all-in-one gamma probe with auto-peak detection for sentinel lymph node biopsy based on NEMA NU3-2004 standard

2021 ◽  
Author(s):  
Aram Radnia ◽  
Hamed Abdollahzadeh ◽  
Behnoosh Teimourian ◽  
Mohammad Hossein Farahani ◽  
Mohammad Esmaeil Akbari ◽  
...  
Keyword(s):  
Lymph Node ◽  
Sentinel Lymph Node ◽  
Gamma Probe ◽  
Peak Detection ◽  
Cesium Iodide ◽  
Shielding Effectiveness ◽  
Scattering Medium ◽  
Silicon Photomultiplier ◽  
Regional Lymph Nodes ◽  
Handheld Device

Abstract Background A gamma probe is a handheld device used for intraoperative interventions following interstitial injection of a radiotracer to locate regional lymph nodes through the external detection of radiation. This work reports on the design and performance evaluation of a novel fully integrated gamma probe (GammaPen), recently developed by our group. Materials and methods GammaPen is an all-in-one pocket gamma probe with low weight and adequate dimensions, consisting of a detector, a control unit and output all together. The detector module consists of a cylindrical Thallium-activated Cesium Iodide [CsI (Tl)] crystal optically coupled to a Silicon photomultiplier (SiPM), shielded using Tungsten housing on side and back faces. The electronics of the probe consists of two small boards to handle signal processing and analog peak detection tasks. A number of parameters, including probe sensitivity in air/water, spatial resolution in air/water, angular resolution in air/water, and side and back shielding effectiveness, were measured to evaluate the performance of the probe based on NEMA NU3-2004 standards. Results The sensitivity of the probe in air at distances of 10, 30, and 50 mm is 18784, 3500, and 1575 cps/MBq. The sensitivity in scattering medium was also measured at distances of 10, 30, and 50 mm as 17,680, 3050, and 1104 cps/MBq. The spatial and angular resolutions in scattering medium were 47 mm and 87 degree at 30 mm distance from the probe, while they were 40 mm and 77 degree in air. The detector shielding effectiveness and leakage sensitivity are 99.91% and 0.09%, respectively. Conclusion The performance characterization showed that GammaPen can be used effectively for sentinel lymph node localization. The probe was successfully used in several surgical interventions by an experienced surgeon confirming its suitability in a clinical setting.

scholarly journals ASKAP observations of multiple rapid scintillators reveal a degrees-long plasma filament

2021 ◽  
Vol 502 (3) ◽  
pp. 3294-3311
Author(s):  
Yuanming Wang ◽  
Artem Tuntsov ◽  
Tara Murphy ◽  
Emil Lenc ◽  
Mark Walker ◽  
...  
Keyword(s):  
Physical Properties ◽  
Angular Width ◽  
Scattering Medium ◽  
Central Frequency ◽  
Linear Arrangement ◽  
Plasma Filament ◽  
Kinematic Models ◽  
Tidal Stream ◽  
First Time ◽  
Insight Into

ABSTRACT We present the results from an Australian Square Kilometre Array Pathfinder search for radio variables on timescales of hours. We conducted an untargeted search over a 30 deg2 field, with multiple 10-h observations separated by days to months, at a central frequency of 945 MHz. We discovered six rapid scintillators from 15-min model-subtracted images with sensitivity of $\sim\! 200\, \mu$Jy/beam; two of them are extreme intra-hour variables with modulation indices up to $\sim 40{{\ \rm per\ cent}}$ and timescales as short as tens of minutes. Five of the variables are in a linear arrangement on the sky with angular width ∼1 arcmin and length ∼2 degrees, revealing the existence of a huge plasma filament in front of them. We derived kinematic models of this plasma from the annual modulation of the scintillation rate of our sources, and we estimated its likely physical properties: a distance of ∼4 pc and length of ∼0.1 pc. The characteristics we observe for the scattering screen are incompatible with published suggestions for the origin of intra-hour variability leading us to propose a new picture in which the underlying phenomenon is a cold tidal stream. This is the first time that multiple scintillators have been detected behind the same plasma screen, giving direct insight into the geometry of the scattering medium responsible for enhanced scintillation.

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