Validation of a Digital Noise Power Integration Technique for Radiometric Clear Sky Attenuation Estimation at Q-Band

An (electron) microscope can be considered as a communication channel that transfers structural information between an object and an observer. In electron microscopy this information is carried by electrons. According to the theory of Shannon the maximal information rate (or capacity) of a communication channel is given by C = B log2 (1 + S/N) bits/sec., where B is the band width, and S and N the average signal power, respectively noise power at the output. We will now apply to study the information transfer in an electron microscope. For simplicity we will assume the object and the image to be onedimensional (the results can straightforwardly be generalized). An imaging device can be characterized by its transfer function, which describes the magnitude with which a spatial frequency g is transferred through the device, n is the noise. Usually, the resolution of the instrument ᑭ is defined from the cut-off 1/ᑭ beyond which no spadal information is transferred.

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Analysis of photographic emulsions for High-Voltage Electron Microscopy

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100148095 ◽

1993 ◽

Vol 51 ◽

pp. 452-453 ◽

Cited By ~ 1

Author(s):

James R. Kremer ◽

Paul S. Furcinitti ◽

Eileen O’Toole ◽

J. Richard McIntosh

Keyword(s):

Electron Microscope ◽

Optical Density ◽

High Voltage ◽

Noise Power ◽

Limited Information ◽

Modulation Transfer ◽

Transmission Microscopy ◽

High Voltage Electron Microscopy ◽

Voltage Range ◽

Voltage Electron

Characteristics of electron microscope film emulsions, such as the speed, the modulation transfer function, and the exposure dependence of the noise power spectrum, have been studied for electron energies (80-100keV) used in conventional transmission microscopy. However, limited information is available for electron energies in the intermediate to high voltage range, 300-1000keV. Furthermore, emulsion characteristics, such as optical density versus exposure, for new or improved emulsions are usually only quoted by film manufacturers for 80keV electrons. The need for further film emulsion studies at higher voltages becomes apparent when searching for a film to record low dose images of radiation sensitive biological specimens in the frozen hydrated state. Here, we report the optical density, speed and relative resolution of a few of the more popular electron microscope films after exposure to 1MeV electrons.Three electron microscope films, Kodak S0-163, Kodak 4489, and Agfa Scientia 23D56 were tested with a JEOLJEM-1000 electron microscope operating at an accelerating voltage of 1000keV.

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A rapid CBF/CMRO2 measurement with a single PET scan with dual-tracer/integration technique in human

Journal of Cerebral Blood Flow & Metabolism ◽

10.1038/sj.jcbfm.9591524.0609 ◽

2005 ◽

Vol 25 (1_suppl) ◽

pp. S609-S609 ◽

Cited By ~ 1

Author(s):

Takuya Hayashi ◽

Nobuyuki Kudomi ◽

Hiroshi Watabe ◽

Hisashi Oka ◽

Kohei Hayashida ◽

...

Keyword(s):

Pet Scan ◽

Integration Technique ◽

Dual Tracer

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Evaluation of net shortwave radiation over China with a regional climate model

Climate Research ◽

10.3354/cr01598 ◽

2020 ◽

Vol 80 (2) ◽

pp. 147-163

Author(s):

X Liu ◽

Y Kang ◽

Q Liu ◽

Z Guo ◽

Y Chen ◽

...

Keyword(s):

Regional Climate Model ◽

Climate Model ◽

Regional Climate ◽

Radiant Energy ◽

Energy System ◽

Radiation Budget ◽

Shortwave Radiation ◽

Monsoon Region ◽

Clear Sky ◽

Sky Conditions

The regional climate model RegCM version 4.6, developed by the European Centre for Medium-Range Weather Forecasts Reanalysis, was used to simulate the radiation budget over China. Clouds and the Earth’s Radiant Energy System (CERES) satellite data were utilized to evaluate the simulation results based on 4 radiative components: net shortwave (NSW) radiation at the surface of the earth and top of the atmosphere (TOA) under all-sky and clear-sky conditions. The performance of the model for low-value areas of NSW was superior to that for high-value areas. NSW at the surface and TOA under all-sky conditions was significantly underestimated; the spatial distribution of the bias was negative in the north and positive in the south, bounded by 25°N for the annual and seasonal averaged difference maps. Compared with the all-sky condition, the simulation effect under clear-sky conditions was significantly better, which indicates that the cloud fraction is the key factor affecting the accuracy of the simulation. In particular, the bias of the TOA NSW under the clear-sky condition was <±10 W m-2 in the eastern areas. The performance of the model was better over the eastern monsoon region in winter and autumn for surface NSW under clear-sky conditions, which may be related to different levels of air pollution during each season. Among the 3 areas, the regional average biases overall were largest (negative) over the Qinghai-Tibet alpine region and smallest over the eastern monsoon region.

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Speech Enhancement Based on Adaptive Noise Power Estimation Using Spectral Difference

IEICE Transactions on Fundamentals of Electronics Communications and Computer Sciences ◽

10.1587/transfun.e94.a.2031 ◽

2011 ◽

Vol E94-A (10) ◽

pp. 2031-2034 ◽

Cited By ~ 2

Author(s):

Jae-Hun CHOI ◽

Joon-Hyuk CHANG ◽

Dong Kook KIM ◽

Suhyun KIM

Keyword(s):

Speech Enhancement ◽

Power Estimation ◽

Noise Power ◽

Spectral Difference ◽

Adaptive Noise

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Object Detection Using an Ideal Observer Model

Electronic Imaging ◽

10.2352/issn.2470-1173.2020.16.avm-041 ◽

2020 ◽

Vol 2020 (16) ◽

pp. 41-1-41-7

Author(s):

Orit Skorka ◽

Paul J. Kane

Keyword(s):

Object Detection ◽

Matched Filter ◽

Image Sensors ◽

Ideal Observer ◽

Noise Power ◽

Relative Evaluation ◽

Detection And Identification ◽

Cross Correlation Analysis ◽

Observer Model ◽

The Ideal

Many of the metrics developed for informational imaging are useful in automotive imaging, since many of the tasks – for example, object detection and identification – are similar. This work discusses sensor characterization parameters for the Ideal Observer SNR model, and elaborates on the noise power spectrum. It presents cross-correlation analysis results for matched-filter detection of a tribar pattern in sets of resolution target images that were captured with three image sensors over a range of illumination levels. Lastly, the work compares the crosscorrelation data to predictions made by the Ideal Observer Model and demonstrates good agreement between the two methods on relative evaluation of detection capabilities.

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