scholarly journals Investigation of Shape-from-Focus Precision by Texture Frequency Analysis

Electronics ◽  
2021 ◽  
Vol 10 (16) ◽  
pp. 1870
Author(s):  
Shinya Onogi ◽  
Toshihiro Kawase ◽  
Takaaki Sugino ◽  
Yoshikazu Nakajima
Keyword(s):  
Optical Imaging ◽  
Frequency Analysis ◽  
Cycle Length ◽  
Measurement Techniques ◽  
Window Size ◽  
Experimental Results ◽  
Depth Measurement ◽  
Focus Measure ◽  
Cycle Lengths ◽  
Shape From Focus

This paper reports the precision of shape-from-focus (SFF) imaging according to the texture frequencies and window sizes of a focus measure. SFF is one of various depth measurement techniques for optical imaging, such as microscopy and endoscopy. SFF measures the depth of an object according to focus measure, which is generally computed with a fixed window. The window size affects the performance of SFF and should be adjusted for the texture of an object. In this study, we investigated the precision difference of SFF in texture frequencies and by window size. Two experiments were performed: precision validation in texture frequencies with a fixed window size, and precision validation in various window sizes related to pixel-cycle lengths. The first experimental results showed that a smaller window size could not provide a correct focus measure, and the second results showed that a window size that is approximately equal to a pixel-cycle length of the texture could provide better precision. These findings could potentially contribute to determining the appropriate window size of focus measure operation in shape-from-focus reconstruction.

Impact of Turning Lane Storage Length and Turning Proportions on Throughput at Oversaturated Signalized Intersections

2021 ◽  
pp. 036119812110171
Author(s):  
A. M. Tahsin Emtenan ◽  
Christopher M. Day
Keyword(s):  
Flow Rate ◽  
Cycle Length ◽  
Signal Timing ◽  
Real World Data ◽  
Left Turn ◽  
Common Response ◽  
Cycle Lengths ◽  
Saturation Flow Rate ◽  
Saturation Flow ◽  
Timing Strategies

During oversaturated conditions, common objectives of signal timing are to maximize vehicle throughput and manage queues. A common response to increases in vehicle volumes is to increase the cycle length. Because the clearance intervals are displayed less frequently with longer cycle lengths and fewer cycles, more of the total time is used for green indications, which implies that the signal timing is more efficient. However, previous studies have shown that throughput reaches a peak at a moderate cycle length and extending the cycle length beyond this actually decreases the total throughput. Part of the reason for this is that spillback caused by the turning traffic may cause starvation of the through lanes resulting in a reduction of the saturation flow rate within each lane. Gaps created by the turning traffic after a lane change may also reduce the saturation flow rate. There is a relationship between the proportions of turning traffic, the storage length of turning lanes, and the total throughput that can be achieved on an approach for a given cycle length and green time. This study seeks to explore this relationship to yield better signal timing strategies for oversaturated operations. A microsimulation model of an oversaturated left-turn movement with varying storage lengths and turning proportions is used to determine these relationships and establish a mathematical model of throughput as a function of the duration of green, storage length, and turning proportion. The model outcomes are compared against real-world data.

Modelling the egg components and internal cycle length of laying hens

2019 ◽  
Vol 59 (3) ◽  
pp. 420 ◽  
Author(s):  
H. C. P. Bendezu ◽  
N. K. Sakomura ◽  
E. B. Malheiros ◽  
R. M. Gous ◽  
N. T. Ferreira ◽  
...  
Keyword(s):  
Cycle Length ◽  
Egg Production ◽  
Laying Hens ◽  
Experimental Period ◽  
Experimental Unit ◽  
Egg Weight ◽  
Cycle Lengths ◽  
Predicted Values ◽  
Egg Components ◽  
Over Time

A model that can estimate the changes that occur to the composition of egg components over time is an important tool for the nutritionists, since it can provide information about the nutrients required by a laying hen to achieve her potential egg output. In this context, the present study was aimed to model the potential egg production of laying hens during the egg-production period. One hundred and twenty Hy-Line W36 and ISA-Brown layers were used from 18 to 60 weeks of age, with each bird being an experimental unit. The birds were housed in individual cages during the experimental period. Egg production (%), egg weight (g) and the weight of egg components were recorded for each bird. The data were used to calculate the parameters of equations for predicting the weights of yolk, albumen and shell, and for predicting internal cycle length. The predicted results were evaluated by regressing residual (observed minus predicted) values of the predicted values centred of their average value. The equations for predicting mean yolk weight with age are for Hy-Line W36 (y1) and ISA-Brown (y2) respectively. Albumen and shell weights for Hy-Line W36 were described by the equations 15.07 × (yolk weight)0.37 and 0.70 × (yolk + albumen weight)0.50 respectively, and for ISA-Brown, 21.99 × (yolk weight)0.24 and 1.60 × (yolk + albumen weight)0.34 respectively. The average internal cycle length over time for Hy-Line W36 (ICL1) is described by the model 22.95 + 5.24 × (0.962t) + 0.02 × t and for ISA-Brown by 24.01 + 10.29 × (0.94t) + 0.004 × t, where t is the age at first egg (days). The assessment of the results indicated that the equations for predicting egg weight were more accurate for Hy-Line W36 but less precise for both strains, whereas the equation models for predicting the internal cycle lengths were more accurate and precise for ISA-Browns. The models could predict the potential weight of egg components and the rate of laying associated with the internal cycle lengths, and, on the basis of this information, it is possible to improve the nutrient requirement estimated.

scholarly journals A Simple Porcine Model of Inducible Sustained Atrial Fibrillation

2016 ◽  
Vol 11 (1) ◽  
pp. 76-78 ◽  
Author(s):  
Anson M. Lee ◽  
Jacob R. Miller ◽  
Rochus K. Voeller ◽  
Andreas Zierer ◽  
Shelly C. Lall ◽  
...  
Keyword(s):  
Atrial Fibrillation ◽  
Animal Model ◽  
Cycle Length ◽  
Porcine Model ◽  
New Technologies ◽  
Median Sternotomy ◽  
Manual Stimulation ◽  
History Of ◽  
Cycle Lengths ◽  
Rapid Pacing

The surgical management of atrial fibrillation (AF) is an evolving field with a history of testing various lesion sets and ablation technologies. Previous animal models of AF require a chronic intervention to make AF reliably inducible. Our objective was to create an acute, reliable, and reproducible porcine model of sustained AF. To accomplish this, 21 adult domestic pigs underwent median sternotomy. Methods to induce AF were then performed sequentially: manual stimulation, rapid pacing (200 beats per minute), and then rapid pacing of 8 beats with a cycle length of 300 milliseconds, followed by an extra stimulus at decreasing cycle lengths. If AF was not induced, burst pacing was performed at a cycle length of 90 milliseconds for 30 seconds. If AF was still not induced, intravenous neostigmine was administered, and the process was repeated. Atrial fibrillation was considered sustained after 1 minute. Attempts at AF induction were successful in 18 (86%) of 21. Atrial fibrillation was induced during manual stimulation in four (19%), during rapid pacing in five (24%), during burst pacing in five (24%), and after the administration of neostigmine in four (19%). Mean (SD) duration of AF was 3.6 (2.6) minutes. Of the 18, 14 (78%) reverted to sinus rhythm spontaneously and 4 (22%) required an antiarrhythmic. This technique of inducing AF can easily be used to evaluate new technologies and lesion sets without the need for creating a chronic animal model.

Demonstration of hysteresis in refractoriness of canine ventricular myocardium

1988 ◽  
Vol 255 (6) ◽  
pp. H1342-H1348
Author(s):  
C. Giorgi ◽  
M. Vermeulen ◽  
R. Cardinal ◽  
P. Savard ◽  
R. Nadeau ◽  
...  
Keyword(s):  
Pulse Width ◽  
Cycle Length ◽  
Ventricular Myocardium ◽  
Ventricular Muscle ◽  
Cycle Lengths ◽  
Long Pulse ◽  
Basic Cycle Length ◽  
Canine Ventricular Myocardium

The properties and determinants of hysteresis during ventricular effective refractory period (VERP) measurements by an extrastimulus technique were determined in 15 anesthetized open-chest dogs as well as in isolated ventricular muscle (n = 6). VERP was determined both by decreasing the S1-S2 interval and also by increasing S1S2. Hysteresis was then calculated by subtracting the VERP obtained with the decreasing S1S2 from the VERP obtained with the increasing S1S2. The effects of basic cycle length, pulse width, stimulation intensity, and the number of basic drives on VERP and hysteresis were evaluated. VERP was shorter for long pulse width, high stimulation intensities, and shorter basic cycle lengths. These modifications were not associated with significant changes of hysteresis. VERP was shorter during decreasing S1S2 than during increasing S1S2. Hysteresis was greater with 6 basic drive cycles than with 12 (P less than 0.001) in both in vivo and in vitro preparations. The data suggest that 1) hysteresis occurs during VERP measurements; 2) hysteresis is independent of stimulation modality; and 3) hysteresis decreases with the number of basic drive cycles.

scholarly journals Diurnal variations of the dominant cycle length of chronic atrial fibrillation

2001 ◽  
Vol 280 (1) ◽  
pp. H401-H406 ◽  
Author(s):  
Carl J. Meurling ◽  
Johan E. P. Waktare ◽  
Fredrik Holmqvist ◽  
Antti Hedman ◽  
A. John Camm ◽  
...  
Keyword(s):  
Atrial Fibrillation ◽  
Cycle Length ◽  
Vagal Tone ◽  
Chronic Atrial Fibrillation ◽  
Frequency Domain Analysis ◽  
Diurnal Variations ◽  
Diurnal Fluctuation ◽  
Cycle Lengths ◽  
Parasympathetic Influences ◽  
Atrial Effective Refractory Period

High-resolution digital Holter recording was carried out in 21 patients (15 men, 64 ± 12 yr) with chronic atrial fibrillation. Dominating atrial cycle length (DACL) was derived by frequency domain analysis of QRST-reduced electrocardiograms. Daytime mean DACL was 150 ± 17 ms, and nighttime mean was 157 ± 22 ms ( P = 0.0002). Diurnal fluctuation in DACL differed among patients: it tended to be virtually absent in those with a short mean DACL, but in those with longer DACL the night-day difference was as much as 23 ms ( R = 0.72, P < 0.001, correlation of mean DACL to night-day difference). Mean DACL also correlated with ventricular cycle length ( R = 0.40, P < 0.001), particularly at night ( r = 0.49). The shorter cycle lengths found in this study during the day are consistent with sympathetic and/or other physiological modulation, but since increased vagal tone shortens atrial refractoriness in most models, parasympathetic influences are not likely to play a major role. Alternatively, atrial effective refractory period may not be the sole determinant of atrial cycle length during atrial fibrillation.

scholarly journals Statistical Significance and Stability of the Hog Cycle

1986 ◽  
Vol 18 (2) ◽  
pp. 227-234 ◽  
Author(s):  
J. Scott Shonkwiler ◽  
Thomas H. Spreen
Keyword(s):  
Time Series ◽  
Cycle Length ◽  
Statistical Significance ◽  
The United States ◽  
Time Series Models ◽  
Hog Industry ◽  
Point Estimates ◽  
Bootstrap Technique ◽  
Cyclical Fluctuations ◽  
Cycle Lengths

AbstractCyclical fluctuations in prices and production have long characterized the United States hog industry. Recent evidence suggests that the length of the hog cycle has changed. In order to determine whether the change in cycle length is statistically significant, the bootstrap technique is employed to derive confidence intervals for point estimates of the hog cycle. Application of the bootstrap technique to time series models is discussed and empirical results are presented. It is concluded that the hog cycle is undergoing rather complicated changes based on cycle lengths that are calculated to be statistically different from zero.

scholarly journals Objective assessment for characterising the flatness of garment sewing stitches

2013 ◽  
Vol 13 (4) ◽  
pp. 110-117
Author(s):  
Jiang Hongxia ◽  
Liu Jihong ◽  
Chai Zhilei ◽  
Wang Chunxia ◽  
Zhang Mingxia
Keyword(s):  
Standard Deviation ◽  
Empirical Mode Decomposition ◽  
Objective Assessment ◽  
Window Size ◽  
Experimental Results ◽  
Classification Method ◽  
Average Area ◽  
Mode Decomposition ◽  
Two Parameters

Abstract In this paper, a novel classification method of assessing garment sewing stitch based on amended bi-dimensional empirical mode decomposition (ABEMD) has been introduced. Two parameters that characterise garment sewing stitch, average area and standard deviation, have been defined based on the grey value of pixels. Experimental results showed that when the window size is 512×128 pixels with regard to average area, the threshold can be decided as 6.00, 5.50, 5.30 and 4.00 for five different grades , respectively. Meanwhile, with regard to standard deviation, the threshold can be decided as 48.00, 40.00, 30.00 and 20.00, respectively. It is demonstrated that the parameters are effective in discriminating sewing stitch images in terms of the grades when used as inputs for the ABEMD. The performance of the algorithm on different garment status is significantly reliable.

Investigation of Heterogeneous Mixtures With Dual-Modality Transducers Fabricated Using Thick-Film Technology

Volume 1 ◽  
2004 ◽  
Author(s):  
Guangtian Meng ◽  
Artur J. Jaworski ◽  
T. Dyakowski ◽  
J. M. Hale ◽  
N. M. White
Keyword(s):  
Thick Film ◽  
Speed Of Sound ◽  
Volume Fraction ◽  
Measurement Techniques ◽  
Electrical Measurement ◽  
Experimental Results ◽  
Process Conditions ◽  
Dual Modality ◽  
Theoretical Predictions ◽  
Thick Film Technology

The work presented in this paper focuses on development of a dual modality sensor, for deployment within an oil and gas extraction plant to measure the composition of oil-water mixtures. The sensors combine ultrasonic and electrical measurement techniques. These are of course non-destructive, rapid, and can potentially provide an on-line industrial measurement. In addition, the combination of two techniques could potentially be reliable in a wider range of process conditions and could contain self-calibration features. The sensors used in the current study were manufactured using thick-film technology, which enables construction of multilayered structures of both conductive and non-conductive layers, some of which may exhibit piezoelectric properties for ultrasonic measurement purposes. These are later fired on a ceramic substrate to provide rugged sensors, capable of working in aggressive industrial environments. Experiments were conducted for mixtures of vegetable oil and saline water to investigate the feasibility of such dual dual-modality sensors. The time of flight of ultrasonic wave in pure liquids and heterogeneous mixtures was measured. It has been shown that the signal obtained from the transducers is sufficiently strong to warrant the measurement of the speed of sound in heterogeneous mixtures of oil and water. A study of the effects of oil concentration and temperature on the speed of sound has been conducted. A mathematical model has been tested, which relates the speed of sound to the volume fraction taking into account the reflection and refraction on the droplet interfaces. The experimental results subjected to linear regression agree very well with the theoretical predictions. The electrical measurement was conducted at three different frequencies. In general, the values of capacitance and conductance decrease with increasing oil percentage. In the middle oil percentages a discontinuity occurs in the decreasing trend. In the high oil percentages, the experimental results agree very well with theoretical predictions.

Effects of infarction, procainamide, coupling interval, and cycle length on refractoriness of extrastimuli

1985 ◽  
Vol 248 (5) ◽  
pp. H606-H613
Author(s):  
F. E. Marchlinski ◽  
M. E. Cain ◽  
R. A. Falcone ◽  
R. F. Corky ◽  
J. F. Spear ◽  
...  
Keyword(s):  
Refractory Period ◽  
Cycle Length ◽  
Narrow Range ◽  
Left Ventricular ◽  
Effective Refractory Period ◽  
Stimulation Site ◽  
Refractory Periods ◽  
Coupling Interval ◽  
Cycle Lengths ◽  
Site Of Stimulation

The effects of prematurity, cycle length, site of stimulation, and procainamide on ventricular refractoriness following an extrastimulus (S2) were assessed in 10 dogs with and 10 dogs without infarction. Extrastimuli were introduced at preselected coupling intervals (S1-S2) from normal right and left ventricular sites and from left ventricular sites of infarction during drive cycle lengths (S1-S1) of 350 and 250 ms. At each S1-S2 interval, the effective refractory period of S2 was determined by introducing a second extrastimulus (S3). At all stimulation sites, cycle lengths, and before and during infusion of procainamide (mean concn 18.6 +/- 3.5 micrograms/ml), shortening (greater than 10 ms change) in refractoriness was most marked over a narrow range of closely coupled S1-S2 intervals. Regardless of stimulation site, the effective refractory period of S2 was less during a cycle length of 250 ms compared with a cycle length of 350 ms. In dogs without infarction, the effective refractory periods of S2 from left ventricular sites tended to be longer than from right ventricular sites, particularly during procainamide administration. The refractory period of S2 at sites of infarction did not differ consistently from those at normal sites. Finally, at all stimulation sites and cycle lengths, procainamide prolonged refractoriness of S2 at each S1-S2 interval and blunted the total shortening in refractoriness in response to S2.

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