Estimation of Time to Vehicle Arrival—Effects of Age on Use of Available Visual Information

Perception ◽  
1994 ◽  
Vol 23 (8) ◽  
pp. 947-955 ◽  
Author(s):  
Errol R Hoffmann
Keyword(s):  
Visual Information ◽  
Age Groups ◽  
Time Estimation ◽  
Threshold Value ◽  
Viewing Time ◽  
Fully Integrated ◽  
Vehicle Velocity ◽  
Significant Difference ◽  
Movement Distance ◽  
The Subject

Subjects estimated time of vehicle arrival while viewing twenty-four film clips of an approaching vehicle, half with a constant viewing time of 4.2 s and half with a constant vehicle-movement distance of 40 m. The distances from the subject at which the film ended were 20, 60, and 100 m. Speeds of approach varied between 7.45 and 15.44 ms−1. Performance was strongly dependent on age of the subject. Subjects in the 5-6-year-old group made estimates based on the distance of the vehicle; at 7 – 8 years an interaction between the effects of distance and velocity appeared and for 9–10-year-olds there was a main effect of the vehicle velocity. Only for adults was the information from distance and velocity fully integrated. There was no significant difference between males and females for any of the age groups. Performance of adults was very similar to that reported by other authors in that subjects underestimated the time to arrival of the vehicle, with estimated times about 60% of the actual times. Standard deviations of the estimated times were such that a small percentage of subjects overestimated times and hence would have caused a collision if they had proceeded with a crossing. The mechanism of time estimation was strongly dependent on the angular velocity of the vehicle subtended at the eye of the observer. This must exceed a threshold value of about 0.002 rad s_1 (adults) if a linear relationship between estimated and actual times is to be obtained.

Investigation of Repeatability of Peak Nasal Inspiratory Flow Rate Measurements Under Baseline Conditions and After Administration of 0.05% Oxymetazoline

2021 ◽  
pp. 194589242110155
Author(s):  
Anna Dor-Wojnarowska ◽  
Anna Radlińska ◽  
Marek Rabski ◽  
Andrzej Fal ◽  
Jerzy Liebhart ◽  
...  
Keyword(s):  
Age Groups ◽  
Threshold Value ◽  
Inspiratory Flow ◽  
Repeated Measurements ◽  
Nasal Patency ◽  
Inspiratory Flow Rate ◽  
Significant Difference ◽  
The Difference ◽  
User Friendly ◽  
Peak Nasal Inspiratory Flow

Objectives Peak nasal inspiratory flow (PNIF) measurement is an inexpensive and user-friendly method to assess nasal patency. However, the repeatability of PNIF measurements, as well as the threshold value of a change in PNIF, which can be considered significant remain unclear. This study aims to investigate the repeatability of PNIF measurements and the change in PNIF after the administration of 0.05% oxymetazoline. Methods Repeated measurements of PNIF (Clement Clarke In-Check nasal inspiratory flow meter; Clement Clarke International, Ltd, Harlow, Essex, UK) were obtained in 333 healthy volunteers (174 women). Based on age, participants were categorized into three groups (6–7 years, 13–14 years, and 20–45 years). We obtained five measurements in each participant. PNIF was remeasured in 294 subjects 30 min after administration of 0.05% oxymetazoline. The variability in PNIF measurements was assessed using the coefficient of variation (CV = standard deviation × 100%/mean). Results The first four PNIF measurements significantly differed from each other. The difference in PNIF measurements ceased to be statistically significant only between the fourth and fifth measurements (p = 0.19). PNIF repeatability was acceptable; the median CV was 15.5% (0–66), which did not significantly differ between age groups. The administration of 0.05% oxymetazoline led to a statistically significant increase in the PNIF value by 14.3% (−45, 157%) (p = 0.000000). Conclusions 1. No statistically significant difference was observed in PNIF values only between the fourth and fifth measurements; therefore, at least three measurements are essential to draw meaningful conclusions. 2. PNIF measurements were satisfactorily characterized by a relatively low CV (15%). 3. The administration of 0.05% oxymetazoline led to an increase in PNIF by approximately 14% over the baseline value.

Research Note: Reduction of Muscular Fatigue Associated with Repetitive Light Assembly Operations by Means of Arm Counterbalancing

1974 ◽  
Vol 16 (3) ◽  
pp. 323-326 ◽  
Author(s):  
Samuel J. Kassab
Keyword(s):  
Conventional Method ◽  
Age Groups ◽  
Research Note ◽  
Muscular Fatigue ◽  
Assembly Task ◽  
Sustained Activity ◽  
Significant Difference ◽  
The Subject ◽  
Assembly Operations ◽  
Muscular Effort

The muscular effort required to perform a light assembly task was monitored by electromyography on each of 14 female subjects under two different methods of assembly. First, the conventional method was studied with the arms unsupported. The second method involved counterbalancing the weight of the arms. A highly significant difference was found between methods, thus indicating that, during sustained activity, muscular effort can be reduced approximately 50% by counterbalancing the weight of the arms. Also, the onset of physiological fatigue is indefinitely delayed, if not completely eliminated, by the utilization of this technique. A comparison between age groups showed little difference attributable to the age of the subject.

scholarly journals Comparison of three methods for calculation of sacroiliac joint index in different age groups in bone scintigraphy

2020 ◽  
Author(s):  
Ebru Salmanoglu
Keyword(s):  
Bone Scintigraphy ◽  
Sacroiliac Joint ◽  
Age Groups ◽  
Region Of Interest ◽  
Threshold Value ◽  
Mean Value ◽  
Data Set ◽  
Mean Values ◽  
Significant Difference ◽  
Group 2

Abstract BackgroundIt was aimed to compare three methods for calculation of sacroiliac joint (SIJ) index in different age groups. Cases undergone Tc-99m MDP bone scintigraphy and images were evaluated. Cases don’t have pathologic uptake were performed posterior pelvic images for calculation of SIJ index.Normal cases (n:160) were included.Cases were separated into four age groups, group 1(3-20 years), group 2(21-40 years), group 3(41-60 years), group 4(61 years and older). For the first method,irregular region of interest (ROI) was selected,for the second method rectangular ROI was selected.For the third method, profile peak counts were used. Count of each SIJ was divided count of sacrum to calculate right, left and mean SIJ indices.ResultsThere was no statistically significant difference between mean values of right and left SIJ index for three methods(p>0.05).Means of female were lower than male for right, left and and mean SIJ indices.Lowest mean values of right SIJ index, left SIJ index and mean SIJ index were found in ≥61 age group in both genders.All of three methods were significantly different from each other according to four age groups(p<0.05). First method had quite lower mean value than second and third methods for right SIJ index.A negative statistically significant correlation was found between age and SIJ index for all of three methods(p<0.01). Statistically significant difference was found between three methods for each age gropus based on mean SIJ index(p<0.05).ConclusionsEach nuclear medicine center should establish their own threshold value according to their own data set in normal cases and patients.

Visual Information and Skill Level in Time-To-Collision Estimation

Perception ◽  
1988 ◽  
Vol 17 (5) ◽  
pp. 623-632 ◽  
Author(s):  
Viola Cavallo ◽  
Michel Laurent
Keyword(s):  
Visual Field ◽  
Visual Information ◽  
Peripheral Vision ◽  
Skill Level ◽  
Viewing Time ◽  
Distance Information ◽  
Driving Experience ◽  
Time To Collision ◽  
The Subject ◽  
The Moment

Previous studies on the visual origin of time-to-collision ( Tc) information have demonstrated that Tc estimates can be based solely on the processing of target expansion rate (optic variable τ). But in the simulated situations used (film clips), there was little reliable information on speed (owing to reduced peripheral vision) and distance (owing to the absence of binocular distance cues) available. In order to determine whether these kinds of information are also taken into account, it is necessary to take an approach where the subject receives a more complete visual input. Thus, an experiment conducted on a circuit under actual driving conditions is reported. Experienced drivers and beginners, who were passengers in a car, had to indicate the moment they expected a collision with a stationary obstacle to take place. Subjects were blindfolded after a viewing time of 3 s. The conditions for speed evaluation (normal versus restricted visual field) and distance evaluation (binocular versus monocular vision) by subjects were varied. The approach speed (30 and 90 km h−1) and actual Tc (3 and 6 s) were also varied. The results show that accuracy of Tc estimation increased with (i) normal visual field, (ii) binocular vision, (iii) higher speeds, and (iv) driving experience. These findings have been interpreted as indicating that both speed and distance information are taken into account in Tc estimation. They suggest furthermore that these two kinds of information may be used differently depending on the skill level of the subject. The results are discussed in terms of the complementarity of the various potentially usable visual means of obtaining Tc information.

Self-Paced Walking as a Method for Exercise Testing in Elderly and Young Men

1976 ◽  
Vol 51 (6) ◽  
pp. 609-612 ◽  
Author(s):  
E. Joan Bassey ◽  
P. H. Fentem ◽  
I. C. MacDonald ◽  
Patricia M. Scriven
Keyword(s):  
Heart Rate ◽  
Physical Condition ◽  
Performance Index ◽  
Walking Speed ◽  
Cardiovascular Response ◽  
Age Groups ◽  
Young Men ◽  
Significant Difference ◽  
The Subject ◽  
A Performance

1. An exercise test has been developed which is suitable for elderly or frail subjects. It is based on free walking at three different speeds on a level indoor course of 256 m. The subject sets his own pace in accord with simple instructions. 2. Twenty-four elderly men and ten young men took part in the study. 3. The time and number of paces taken to cover two sections of 100 m within the course were used to establish that the subjects walked steadily. Walking speed, pace frequency and stride length were then calculated. 4. Heart rate was obtained with body-borne tape recorders and related to the walking speed. The heart rate at a standard walking speed could then be obtained by interpolation. This is an assessment of the cardiovascular response to exercise (physical condition). The variation on repeating the test was ±5% and there was no significant difference between the two age groups. 5. The assessment was found to correlate moderately well with a conventional assessment of physical condition based on oxygen uptake from tests on a bicycle ergometer. 6. The test could also be used as a performance index since walking speed was characteristic for the subject. The younger group walked significantly faster than the older group. As a performance index the test is therefore sensitive to age differences.

Liver Elastography in Healthy Children Using Three Different Systems – How Many Measurements Are Necessary?

2020 ◽  
Author(s):  
Anders Batman Mjelle ◽  
Anesa Mulabecirovic ◽  
Roald Flesland Havre ◽  
Edda Jonina Olafsdottir ◽  
Odd Helge Gilja ◽  
...  
Keyword(s):  
Shear Wave ◽  
Transient Elastography ◽  
Intraclass Correlation ◽  
Age Groups ◽  
Liver Stiffness ◽  
Shear Wave Elastography ◽  
Healthy Children ◽  
Significant Difference ◽  
Pediatric Liver Disease ◽  
Liver Elastography

Abstract Purpose Liver elastography is increasingly being applied in screening for and follow-up of pediatric liver disease, and has been shown to correlate well with fibrosis staging through liver biopsy. Because time is of the essence when examining children, we wanted to evaluate if a reliable result can be achieved with fewer acquisitions. Materials and Methods 243 healthy children aged 4–17 years were examined after three hours of fasting. Participants were divided into four age groups: 4–7 years; 8–11 years; 12–14 years and 15–17 years. Both two-dimensional shear wave elastography (2D-SWE; GE Logiq E9) and point shear wave elastography (pSWE; Samsung RS80A with Prestige) were performed in all participants, while transient elastography (TE, Fibroscan) was performed in a subset of 87 children aged 8–17 years. Median liver stiffness measurement (LSM) values of 3, 4, 5, 6, 7, and 8 acquisitions were compared with the median value of 10 acquisitions (reference standard). Comparison was performed for all participants together as well as within every specific age group. We investigated both the intraclass correlation coefficient (ICC) with absolute agreement and all outliers more than 10 %, 20 % or ≥ 0.5 or 1.0 kPa from the median of 10 acquisitions. Results For all three systems there was no significant difference between three and ten acquisitions, with ICCs ≥ 0.97. All systems needed 4 acquisitions to achieve no LSM deviating ≥ 1.0 kPa of a median of ten. To achieve no LSM deviating ≥ 20 % of a median of ten acquisitions, pSWE and TE needed 4 acquisitions, while 2D-SWE required 6 acquisitions. Conclusion Our results contradict recommendations of 10 acquisitions for pSWE and TE and only 3 for 2D-SWE.

The influence of osteopathic correction on the rate of various rhythms of the body

2019 ◽  
pp. 64-71 ◽  
Author(s):  
A. E. Chernikova ◽  
Yu. P. Potekhina
Keyword(s):  
Heart Rate ◽  
Respiratory Rate ◽  
Age Groups ◽  
Biomechanical Properties ◽  
Dispersion Analysis ◽  
The Body ◽  
Body Tissues ◽  
Age Related ◽  
Significant Difference ◽  
Before And After

Introduction. An osteopathic examination determines the rate, the amplitude and the strength of the main rhythms (cardiac, respiratory and cranial). However, there are relatively few studies in the available literature dedicated to the influence of osteopathic correction (OC) on the characteristics of these rhythms.Goal of research — to study the influence of OC on the rate characteristics of various rhythms of the human body.Materials and methods. 88 adult osteopathic patients aged from 18 to 81 years were examined, among them 30 men and 58 women. All patients received general osteopathic examination. The rate of the cranial rhythm (RCR), respiratory rate (RR) heart rate (HR), the mobility of the nervous processes (MNP) and the connective tissue mobility (CTM) were assessed before and after the OC session.Results. Since age varied greatly in the examined group, a correlation analysis of age-related changes of the assessed rhythms was carried out. Only the CTM correlated with age (r=–0,28; p<0,05) in a statistically significant way. The rank dispersion analysis of Kruskal–Wallis also showed statistically significant difference in this indicator in different age groups (p=0,043). With the increase of years, the CTM decreases gradually. After the OC, the CTM, increased in a statistically significant way (p<0,0001). The RCR varied from 5 to 12 cycles/min in the examined group, which corresponded to the norm. After the OC, the RCR has increased in a statistically significant way (p<0,0001), the MNP has also increased (p<0,0001). The initial heart rate in the subjects varied from 56 to 94 beats/min, and in 15 % it exceeded the norm. After the OC the heart rate corresponded to the norm in all patients. The heart rate and the respiratory rate significantly decreased after the OC (р<0,0001).Conclusion. The described biorhythm changes after the OC session may be indicative of the improvement of the nervous regulation, of the normalization of the autonomic balance, of the improvement of the biomechanical properties of body tissues and of the increase of their mobility. The assessed parameters can be measured quickly without any additional equipment and can be used in order to study the results of the OC.

The Influence of Age and Gender on Mandibular Indices among the Libyan Population

2019 ◽  
Vol 3 (2) ◽  
Keyword(s):  
Negative Correlation ◽  
Bone Mineralization ◽  
Age Groups ◽  
T Test ◽  
Chi Square ◽  
Age And Gender ◽  
Significant Difference ◽  
Chi Square Test ◽  
And Gender ◽  
Libyan Population

Radiographic Mandibular Indices serve as easy and relatively cheap tools for evaluating bone mineralization. Objectives: To examine the effect of age and gender on three mandibular indices: the panoramic mandibular index (PMI), the mandibular ratio (MR) and the mandibular cortical index (MCI), among Libyan population. Methods: The three indices were measured on 317 digital (OPGs) of adult humans (155 males, 162 females). The sample was divided into six age groups (from 18-25 years through 56-65 years). The measurements were analyzed for interactions with age and sex, using SPSS (Statistical Package for Social Studies) software version no. 22. The tests employed were two way ANOVA, the unpaired T-test and chi-square test. Results: The mean PMI fluctuated between 0.37 s.d. 0.012 and 0.38 s.d. 0.012. among the sixth age groups. One-way ANOVA statistical test revealed no significant of age on PMI. On the other hand gender variation has effect on PMI, since independent sample t-test disclosed that the difference between the male and female PMI means statistically significant. ANOVA test showed that the means of MR among age groups showed a negative correlation i.e. MR mean declined from 3.01 in 18-25 age groups to 2.7 in 55-65 age groups. In contrary, the gender showed no effect on MR according two sample t-test at p> 0.05. In regards with MCI, statistical analysis showed that it affected by age that is C1 was decreasing by age while C2 and C3 were increased by age. Using chi square test the result indicated that there is a significant difference among the different age group and the two genders in MCI readings. Conclusion: PMI was influenced significantly by age but minimally by the gender. MR is not affected by gender but has a negative correlation with age. MCI is affected by both age and gender

SENSITIVITAS ETIS MAHASISWA ATAS PENGGELAPAN PAJAK

2017 ◽  
Vol 8 (2) ◽  
pp. 178-195
Author(s):  
Nurma Risa
Keyword(s):  
Tax Evasion ◽  
Female Students ◽  
T Test ◽  
Study Program ◽  
Male And Female ◽  
Political Sciences ◽  
Significant Difference ◽  
The Subject ◽  
And Gender ◽  
Management Students

This study aims to prove that there is a difference of perception about ethics on tax evasion in UNISMA Bekasi students, based on selected study program and gender. The sample of this research is the students who have fulfilled the subject of taxation, at the Faculty of Economics (FE) and Faculty of Social and Political Sciences (FISIP). Using independent t-test, the results showed that there was no significant difference of perception about tax evasion ethics between FE and FISIP students. But significant differences the perception of tax evasion ethics occur between accounting and management students at FE. Significant differences also did not occur between male and female students

Properties of Gliricidia Wood (Gliricidia sepium) lntercropped with Cocoa (Theobroma cocoa) in Malaysia

2014 ◽  
Vol 11 (1) ◽  
pp. 51
Author(s):  
Mohd Helmy Ibrahim ◽  
Mohd Nazip Suratman ◽  
Razali Abd Kader
Keyword(s):  
Cell Wall ◽  
Specific Gravity ◽  
Moisture Content ◽  
Wall Thickness ◽  
Age Groups ◽  
Gliricidia Sepium ◽  
Cell Wall Thickness ◽  
Tree Age ◽  
Lumen Diameter ◽  
Significant Difference

Trees planted from agroforestry practices can become valuable resources in meeting the wood requirements of many nations. Gliricidia sepium is an exotic species introduced to the agricultural sector in Malaysia mainly for providing shade for cocoa and coffee plantations. This study investigates its wood physical properties (specific gravity and moisture content) and fibre morphology (length, lumen diameter and cell wall thickness) of G. sepium at three intervals according to age groups ( three, five and seven years of ages). Specific gravity (0.72) was significantly higher at seven years ofage as compared to five (0.41) and three (0.35) years age group with a mean of 0.43 (p<0.05). Mean moisture content was 58.3% with no significant difference existing between the tree age groups. Fibre diameter (22.4 mm) was significantly lower (p<0.05) for the trees which were three years of age when compared to five and seven years age groups (26.6 mm and 24. 7 mm), respectively. Means of fibre length, lumen diameter and cell wall thickness were 0.83 mm, 18.3 mm, and 6.2 mm, respectively, with no significant differences detected between trees in all age groups. Further calculation on the coefficient of suppleness and runkel ratio suggest that wood from G.sepium may have the potential for insulation board manufacturing and paper making. However, future studies should experiment the utilisation of this species for these products to determine its full potential.

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