Reduction of Acquisition Time for RIL, SDL, and LADA

2007 ◽  
Author(s):  
Arjan Mels ◽  
Frank Zachariasse
Keyword(s):  
Background Noise ◽  
Signal Strength ◽  
Acquisition Time ◽  
Optimal Conditions ◽  
Signal Collection ◽  
Defect Localization ◽  
Model Equations ◽  
Set Up ◽  
Main Operating ◽  
Quantitative Tool

Abstract Although RIL, SDL and LADA are slightly different, the main operating principle is the same and the theory for defect localization presented in this paper is applicable to all three methods. Throughout this paper the authors refer to LADA, as all experimental results in this paper were obtained with a 1064nm laser on defect free circuits. This paper first defines mathematically what 'signal strength' actually means in LADA and then demonstrates a statistical model of the LADA situation that explains the optimal conditions for signal collection and the parameters involved. The model is tested against experimental data and is also used to optimise the acquisition time. Through this model, equations were derived for the acquisition time needed to discern a LADA response from the background noise. The model offers a quantitative tool to estimate the feasibility of a given LADA measurement and a guide to optimising the required experimental set-up.

scholarly journals Simple low dose radiography allows precise lung volume assessment in mice

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Amara Khan ◽  
Andrea Markus ◽  
Thomas Rittmann ◽  
Jonas Albers ◽  
Frauke Alves ◽  
...  
Keyword(s):  
Lung Function ◽  
Whole Body ◽  
Acquisition Time ◽  
Micro Ct ◽  
Lung Volumes ◽  
X Ray ◽  
Promising Tool ◽  
Volume Assessment ◽  
Set Up ◽  
Time Required

AbstractX-ray based lung function (XLF) as a planar method uses dramatically less X-ray dose than computed tomography (CT) but so far lacked the ability to relate its parameters to pulmonary air volume. The purpose of this study was to calibrate the functional constituents of XLF that are biomedically decipherable and directly comparable to that of micro-CT and whole-body plethysmography (WBP). Here, we developed a unique set-up for simultaneous assessment of lung function and volume using XLF, micro-CT and WBP on healthy mice. Our results reveal a strong correlation of lung volumes obtained from radiographic XLF and micro-CT and demonstrate that XLF is superior to WBP in sensitivity and precision to assess lung volumes. Importantly, XLF measurement uses only a fraction of the radiation dose and acquisition time required for CT. Therefore, the redefined XLF approach is a promising tool for preclinical longitudinal studies with a substantial potential of clinical translation.

scholarly journals Now you see it, now you don't: optimal parameters for interslice stimulation in concurrent TMS-fMRI

2021 ◽  
Author(s):  
Catriona L Scrivener ◽  
Jade B Jackson ◽  
Marta Morgado Correia ◽  
Marius Mada ◽  
Alexandra Woolgar
Keyword(s):  
Single Channel ◽  
Signal To Noise Ratio ◽  
Brain Activity ◽  
Surface Coil ◽  
Acquisition Time ◽  
Surface Coils ◽  
Human Participant ◽  
Set Up ◽  
Promising Avenue ◽  
Slice Acquisition

The powerful combination of transcranial magnetic stimulation (TMS) concurrent with functional magnetic resonance imaging (fMRI) provides rare insights into the causal relationships between brain activity and behaviour. Despite a recent resurgence in popularity, TMS-fMRI remains technically challenging. Here we examined the feasibility of applying TMS during short gaps between fMRI slices to avoid incurring artefacts in the fMRI data. We quantified signal dropout and changes in temporal signal-to-noise ratio (tSNR) for TMS pulses presented at timepoints from 100ms before to 100ms after slice onset. Up to 3 pulses were delivered per volume using MagVenture's MR-compatible TMS coil. We used a spherical phantom, two 7-channel TMS-dedicated surface coils, and a multiband (MB) sequence (factor=2) with interslice gaps of 100ms and 40ms, on a Siemens 3T Prisma-fit scanner. For comparison we repeated a subset of parameters with a more standard single-channel TxRx (birdcage) coil, and with a human participant and surface coil set up. We found that, even at 100% stimulator output, pulses applied at least -40ms/+50ms from the onset of slice readout avoid incurring artifacts. This was the case for all three setups. Thus, an interslice protocol can be achieved with a frequency of up to ~10 Hz, using a standard EPI sequence (slice acquisition time: 62.5ms, interslice gap: 40ms). Faster stimulation frequencies would require shorter slice acquisition times, for example using in-plane acceleration. Interslice TMS-fMRI protocols provide a promising avenue for retaining flexible timing of stimulus delivery without incurring TMS artifacts.

scholarly journals Animated virtual characters to explore audio-visual speech in controlled and naturalistic environments

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Raphaël Thézé ◽  
Mehdi Ali Gadiri ◽  
Louis Albert ◽  
Antoine Provost ◽  
Anne-Lise Giraud ◽  
...  
Keyword(s):  
Speech Processing ◽  
Background Noise ◽  
Mcgurk Effect ◽  
Visual Speech ◽  
Natural Speech ◽  
Virtual Characters ◽  
Speech Stimuli ◽  
Stimulus Timing ◽  
Phonetic Features ◽  
Set Up

Abstract Natural speech is processed in the brain as a mixture of auditory and visual features. An example of the importance of visual speech is the McGurk effect and related perceptual illusions that result from mismatching auditory and visual syllables. Although the McGurk effect has widely been applied to the exploration of audio-visual speech processing, it relies on isolated syllables, which severely limits the conclusions that can be drawn from the paradigm. In addition, the extreme variability and the quality of the stimuli usually employed prevents comparability across studies. To overcome these limitations, we present an innovative methodology using 3D virtual characters with realistic lip movements synchronized on computer-synthesized speech. We used commercially accessible and affordable tools to facilitate reproducibility and comparability, and the set-up was validated on 24 participants performing a perception task. Within complete and meaningful French sentences, we paired a labiodental fricative viseme (i.e. /v/) with a bilabial occlusive phoneme (i.e. /b/). This audiovisual mismatch is known to induce the illusion of hearing /v/ in a proportion of trials. We tested the rate of the illusion while varying the magnitude of background noise and audiovisual lag. Overall, the effect was observed in 40% of trials. The proportion rose to about 50% with added background noise and up to 66% when controlling for phonetic features. Our results conclusively demonstrate that computer-generated speech stimuli are judicious, and that they can supplement natural speech with higher control over stimulus timing and content.

scholarly journals Influence of restricting the diet on breeding in genetically obese mice

1972 ◽  
Vol 6 (1) ◽  
pp. 9-18 ◽  
Author(s):  
A. Eastcott
Keyword(s):  
Food Intake ◽  
Optimal Conditions ◽  
Obese Mice ◽  
Male Mice ◽  
Restricted Diet ◽  
The Mean ◽  
Set Up ◽  
Mean Time ◽  
Obese Male

A system for breeding from obese male mice ( ob/ob) by restricting food intake is described. It is shown that a 40% reduction in food intake at 6½-8½ weeks of age is optimal in the colony under review. Males on restricted diet did not mate immediately but went through a period of adaptation; the mean time before vaginal plugs were observed was 30 days. Subsequent vaginal plugs occurred on average every 17 days and 69% of these matings resulted in litters. Under optimal conditions over 90% of all obese males set up on restricted diets mated and sired young.

Using Radio Frequency Identification for Indoor Location Identification Based on Power Level, Signal Strength and Fuzzy Method

2011 ◽  
Vol 15 (9) ◽  
pp. 1287-1298
Author(s):  
Rung-Ching Chen ◽  
◽  
Yu-Cheng Lin ◽  
Sheng-Ling Huang ◽  
Qiangfu Zhao
Keyword(s):  
Radio Frequency ◽  
Radio Frequency Identification ◽  
Power Level ◽  
Academic Research ◽  
Signal Strength ◽  
Location Tracking ◽  
Position Location ◽  
Reference Tags ◽  
Frequency Identification ◽  
Set Up

In recent years, there has been a dramatic proliferation of research concerned with Radio Frequency Identification (RFID). RFID technologies are getting considerable attention not only from academic research but also from the applications for enterprise. One of the most important application issues prevailing throughout the last few decades of RFID application research is the indoor position location. Many researchers have used varied technologies to perform the action of indoor position location tracking. In our research, we propose a new method using RFID tags to perform indoor position location tracking. This method uses Received Signal Strength (RSS) to collect signal strengths from reference tags beforehand, and then uses the signal strengths to set up Power Level areas of range by reference tags. Next, using the signal strengths from the reference tags we match signal strengths with track tags. Finally, when the track tags are set up in indoor environments, they can find the position of neighboring reference tags by using the fuzzy set theory and an arithmetic mean to calculate the position location values; with this method we are able to break figures down to track tag position locations. We conducted this experiment to prove that our methodology can provide better accuracy than the LANDMARC system.

scholarly journals Optimizing signal collection efficiency of the VIPA-based Brillouin spectrometer

2015 ◽  
Vol 08 (04) ◽  
pp. 1550021 ◽  
Author(s):  
Zhaokai Meng ◽  
Vladislav V. Yakovlev
Keyword(s):  
Optical Imaging ◽  
Background Noise ◽  
Viscoelastic Properties ◽  
Collection Efficiency ◽  
Signal Loss ◽  
Brillouin Spectroscopy ◽  
Strong Signal ◽  
Direct Assessment ◽  
Signal Collection ◽  
Properties Of Materials

Brillouin spectroscopy is an emerging tool for microscopic optical imaging as it allows for noninvasive and direct assessment of the viscoelastic properties of materials. Recent advances of background-free confocal Brillouin spectrometer allows investigators to acquire the Brillouin spectra for turbid samples as well as transparent ones. However, due to strong signal loss induced by the imperfect optical setup, the Brillouin photons are usually immersed in background noise. In this report, we proposed and experimentally demonstrated multiple approaches to enhance the signal collection efficiency. A signal enhancement by > 4 times can be observed, enabling observation of ultra-weak signals.

Modeling Research of Background Noise in Low-Voltage Power Line Communication Channel

2012 ◽  
Vol 516-517 ◽  
pp. 1386-1390 ◽  
Author(s):  
Hao Kun Guo ◽  
Jun Ji Wu ◽  
Zhan Feng Ying
Keyword(s):  
Singular Value Decomposition ◽  
Background Noise ◽  
Low Voltage ◽  
Power Line ◽  
Singular Value ◽  
Ar Model ◽  
Recursive Method ◽  
Noise Interference ◽  
Set Up ◽  
Value Decomposition

Background noise interference is one of the most important factors for low-voltage power line communication’s reliability. By analyzing the background noise of low-voltage power line communication’s channel, the background noise’s measuring circuit is set up and the AR model of the measured background noise is established. Both of them are respectively using singular value decomposition and Levinson-Durbin (LD) recursive method to calculate the AR model’s parameters and a comparative analysis of the simulation is made. The results induct: parameters acquired from the methods of singular value decomposition and LD recursive method are feasible, the parameter model from singular value decomposition is relatively complex, but extremely accurate, which is suitable for the off-line calculation and analysis of the low-voltage power line’s background noise; the parameter model from LD recursive method is very simple, but has a greater loss of accuracy, fitting for online quickly generation of the low-voltage power line’s background noise.

The External Ion Microbeam of the LABEC Laboratory in Florence: Some Applications to Cultural Heritage

2011 ◽  
Vol 17 (5) ◽  
pp. 661-666 ◽  
Author(s):  
Silvia Calusi
Keyword(s):  
Cultural Heritage ◽  
Ion Beam ◽  
Acquisition Time ◽  
Distribution Maps ◽  
Composition And Structure ◽  
Sample Composition ◽  
Beam Analysis ◽  
Powerful Analytical Tool ◽  
Set Up ◽  
Damage Risk

AbstractIon beam analysis (IBA) techniques are a powerful analytical tool used to investigate the composition and structure of precious materials principally because they can be applied in atmosphere. Thus, the sample can be analyzed as is, and heating and charging effects are strongly diminished. Since IBA measurements can be made with low ion currents and acquisition time, the damage risk is limited. At the microbeam line of the LABEC laboratory, it is possible to exploit the potentials of IBA techniques in an external set up to reconstruct the distribution maps of all the detected elements over the analyzed area with spatial resolutions as low as 10 μm. This is an important feature when objects with inhomogeneous structures—on a scale of hundred microns or so—are investigated, as happens in some cases with artworks. The detection set up installed on our external microbeam allows us to use different IBA techniques simultaneously. Thus, in a single measurement run, it is possible to obtain complementary information on both sample composition and structure. Some applications to works of art are presented here as examples of the analytical capabilities of the external scanning microbeam in the cultural heritage field.

scholarly journals Decoloration of waste PET alcoholysis liquid by an electrochemical method

2018 ◽  
Vol 77 (10) ◽  
pp. 2463-2473
Author(s):  
Yanyan Li ◽  
Mengjuan Li ◽  
Jing Lu ◽  
Xiaoqiang Li ◽  
Mingqiao Ge
Keyword(s):  
Current Density ◽  
Degradation Mechanism ◽  
Statistical Design ◽  
Optimal Conditions ◽  
Liquid Chromatography Mass Spectrometry ◽  
Visible Absorption ◽  
Initial Ph ◽  
Predicted Model ◽  
Catalyst Dosage ◽  
Main Operating

Abstract Disperse Red 60 simulated polyester alcoholysis liquid decoloration by electro-Fenton with Fe3O4 catalyst was studied. The influences of the main operating parameters such as catalyst dosage (0.3–0.9 g/L), current density (60–120 mA/cm2) and pH (1–7) were optimized by response surface methodology (RSM) based on Box–Behnken surface statistical design (BBD). In optimal conditions, the initial concentration of 25 mg/L disperse red polyester alcoholysis liquid was catalyzed by 0.6 g/L Fe3O4, and the decoloration efficiency was 97.18% with the current density of 90 mA/cm2 and initial pH of 4.6. There was a relative error of 1.18% with the predicted model when the predictive value was 98.25% under the same conditions. In addition, ultraviolet-visible absorption spectra (UV-Vis), Fourier transform infrared spectroscopy (FTIR) and thermogravimetric analysis (TGA) were used to study the degradation mechanism during decoloration. The intermediates were identified and the proposed degradation pathways were investigated by liquid chromatography-mass spectrometry (LC-MS) analysis.

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