scholarly journals Age Factor and Pedestrian Speed on Sidewalks

2018 ◽  
Vol 10 (11) ◽  
pp. 4084 ◽  
Author(s):  
Francesco Pinna ◽  
Roberto Murrau
Keyword(s):  
Statistical Model ◽  
Linear Relationship ◽  
Walking Speed ◽  
Polynomial Model ◽  
Sustainable Mobility ◽  
Pedestrian Behavior ◽  
Age Class ◽  
Last Mile ◽  
Age Factor ◽  
The Mean

Pedestrian infrastructures feature the spaces where every user accesses all the mobility forms: in fact, every movement begins and finishes with a walking section. For this reason, it is very important to pay more attention towards what is said “last mile”, that must be designed and constructed to be easily used from the major part of users, with a special attention to more disadvantage citizens. Among all pedestrian characteristics, the least considered is speed, and when it is considered, the reference is the mean speed, that is the speed of the most likely common user. There are numerous and simultaneous factors that influence pedestrian behavior. The age factor mainly determines the psycho-physical characteristics and therefore the behavior. In the present study, it has been observed the behavior on sidewalks with reference to age. The study is based on a survey carried out in the downtown of Oristano, with a total pedestrian flow of 14,182 users. The purpose is, first, to understand how pedestrian speed varies with age, and subsequently to assess if a statistical model exists to describe the pedestrian behavior by age. After a general analysis of pedestrian behavior, the paper focused on users walking not alone but within a flow. The research considers pedestrian speed in real conditions and not isolated pedestrian speed because a pedestrian, inevitably, interacts with other pedestrians and this provides a particular condition. For this reason, the main analysis is based on a subdataset formed by the 2794 individual pedestrians. The analysis shows that there is not a linear relationship between speed and age, but it is better to consider a polynomial model between the mean individual pedestrian speed, mean walking speed and age class. Results show that speed of individual pedestrians decreases as age increases; younger pedestrians walk faster than others, with a difference of 19.2% respect to older ones. This decrease can be represented by a statistical model. The model also shows that there is not a linear relationship between speed and age, but it is better to consider a polynomial model between the mean individual pedestrian speed, mean walking speed and age class. It is necessary to underline this aspect because many efforts have been made all over the world to promote sustainable mobility. Walking is one of the most important aspect of sustainability, so we will aspect an increase of the number of new walking citizens. But it is necessary to consider how population is growing, with a growing number of senior citizens. It is for these users that we will have to plan in the future. In conclusion, the paper studied the mean individual pedestrian speed and its relationship with age and mean walking speed, finding statistical models able to interpret pedestrian behavior; the choice of the mean individual pedestrian speed as dependent variable is the novelty of the study because analyzes a real condition. In fact, the most common case is that of a pedestrian walking within a flow, and not alone. This is an element distinguishing this study from many others. For this reason, this study can help to improve research in this area and could be useful to understand how to plan and to design pedestrian infrastructures. It would also be important to apply this method to other cities with similar characteristics to verify the real transferability of the model and, consequently, of the results.

A Test of the Relationship between Otolith Weight and Age for the Pilchard Sardinops neopilchardus

1991 ◽  
Vol 48 (1) ◽  
pp. 35-38 ◽  
Author(s):  
W. J. Fletcher
Keyword(s):  
Linear Relationship ◽  
Uniform Distribution ◽  
Frequency Distribution ◽  
Direct Relationship ◽  
Original Sample ◽  
Age Classes ◽  
Age Class ◽  
The Mean ◽  
The Relationship ◽  
Additional Sample

A sample of 60 fish revealed a near-linear relationship between otolith weight and the estimated age (determined from scale and otolith annuli) for the pilchard Sardinops neopilchardus, with little overlap of otolith weight values between age classes. In an additional sample of 612 fish where only otolith weight and length were measured, only two clear length modes were found, but five modes using an otolith weight frequency distribution could be distinguished. The means of the five modes were similar to that predicted from the mean weights for each age class in the original sample of 60 fish. These five modes were also present in a subsample of the 612 fish, chosen such that their lengths formed a uniform distribution (i.e. no modes). These results were consistent with a direct relationship between otolith weight and age, but further validation is required before this variable can be used as the sole determinant of age.

Population parameters of ringed seals (Phoca hispida Schreber, 1775) in the Svalbard area

1987 ◽  
Vol 65 (4) ◽  
pp. 1021-1027 ◽  
Author(s):  
Christian Lydersen ◽  
Ian Gjertz
Keyword(s):  
Sex Ratio ◽  
Ringed Seal ◽  
Adult Males ◽  
Population Parameters ◽  
Phoca Hispida ◽  
Age Class ◽  
Ringed Seals ◽  
Males And Females ◽  
The Mean ◽  
Sexually Mature

Samples were taken from 284 ringed seals (Phoca hispida) in the Svalbard area during April–July 1981 and March–April 1982. The age of 283 seals was determined by reading annuli in the cementum of the canine teeth. The mean age of the males was 11.3 years, and of the females, 14.9 years. Females were found to be significantly older than males. The mean length of sexually mature ringed seals was 128.9 cm for both sexes. The mean weight of adult males and females was 53.5 and 61.4 kg, respectively. Females were found to be significantly heavier than males. The sex ratio was 47.8% males and 52.2% females. Studies of microscopic sections of testis and epididymis from ringed seal males showed that 63, 75, and 80% of 5-, 6-, and 7-year-old animals, respectively, were sexually mature. The weights of testis and epididymis, diameters of tubuli, and the size of testis all showed a marked increase in the 5-year age-class. Macroscopic sections of ovaries from ringed seal females showed that 20, 60, and 80% of 3-, 4-, and 5-year-old animals, respectively, were sexually mature. The size of the ovaries showed a marked increase in the 5-year age-class. The ovulation rate of ringed seals from Svalbard was calculated to be 0.91.

Serial Assessment of Ductus Arteriosus Hemodynamics in Hyaline Membrane Disease

PEDIATRICS ◽  
1996 ◽  
Vol 98 (6) ◽  
pp. 1149-1153
Author(s):  
Ernest Z. Phillipos ◽  
Murray A. Robertson ◽  
Paul J. Byrne
Keyword(s):  
Clinical Outcome ◽  
Linear Relationship ◽  
Aortic Root ◽  
Left Atrial ◽  
Ductus Arteriosus ◽  
Hyaline Membrane Disease ◽  
Root Diameter ◽  
Shunt Volume ◽  
Hyaline Membrane ◽  
The Mean

Objectives. To assess the efficacy of Doppler echocardiography (DE) in the quantification of patent ductus arteriosus (PDA) shunt volume and to correlate PDA shunt volume with clinical outcome in infants with hyaline membrane disease. Methods. Ninety-eight DE studies were performed in 30 preterm ventilated infants with hyaline membrane disease within the first 24 hours of age and then at 48-hour intervals to a maximum of three studies while ventilated with a final study after extubation. Right and left ventricular outputs (QRV and QLV, respectively) and PDA flow were calculated using cross-sectional area and flow velocity integrals. Left atrial-to-aortic root diameter measurements were also taken. Clinical outcomes were correlated with the shunt fraction (QLV/QRV). Results. QLV/QRV demonstrated a linear relationship with the left atrial-to-aortic root diameter ratio (n = 92; r = .79). In the absence of a PDA (n = 33 studies), QRV versus QLV demonstrated a linear relationship (r = .88). In the presence of a PDA (n = 64 studies) the mean QLV (334 ± 133 ml/kg per minute) was significantly greater than the mean QRV (237 ± 84 ml/kg per minute). There was a linear relationship between QLV - QRV (PDA shunt volume) and PDA flow (n = 60; r = .84). In studies with exclusive left-to-right shunting at the PDA (n = 48), the mean QLV - QRV (112 ± 83 ml/kg per minute) was significantly higher than in those with bidirectional shunting (n = 16; mean QLV - QRV = 50 ± 27 ml/kg per minute). Two infants with severe intraventricular hemorrhage (IVH grade 3) and two infants with periventricular leukomalacia (PVL) had significantly higher QLV/QRV (2.09 ± 0.36 and 1.67 ± 0.02 respectively) than those with no IVH (n = 6; QLV/QRV = 1.31 ± 0.18) or those with IVH grades 1 and 2 (n = 8; QLV/QRV = 1.48 ± 0.27). There was no difference in QLV/QRV in infants with or without bronchopulmonary dysplasia retinopathy of prematurity. Necrotizing enterocolitis did not develop in any of the 30 infants. Conclusion. PDA shunt volume can be quantified by DE. Larger studies are needed to correlate clinical outcome with QLV/QRV.

scholarly journals Discussion of Identification, Estimation and Approximation of Risk under Interventions that Depend on the Natural Value of Treatment Using Observational Data, by Jessica Young, Miguel Hernán, and James Robins

2014 ◽  
Vol 3 (1) ◽  
Author(s):  
Mark J. van der Laan ◽  
Alexander R. Luedtke ◽  
Iván Díaz
Keyword(s):  
Statistical Model ◽  
Observational Data ◽  
Robust Estimation ◽  
Statistical Estimation ◽  
Estimation Problem ◽  
Target Parameter ◽  
Adaptive Parameters ◽  
The Mean ◽  
Data Adaptive ◽  
Statistical Estimation Problem

AbstractYoung, Hernán, and Robins consider the mean outcome under a dynamic intervention that may rely on the natural value of treatment. They first identify this value with a statistical target parameter, and then show that this statistical target parameter can also be identified with a causal parameter which gives the mean outcome under a stochastic intervention. The authors then describe estimation strategies for these quantities. Here we augment the authors’ insightful discussion by sharing our experiences in situations where two causal questions lead to the same statistical estimand, or the newer problem that arises in the study of data adaptive parameters, where two statistical estimands can lead to the same estimation problem. Given a statistical estimation problem, we encourage others to always use a robust estimation framework where the data generating distribution truly belongs to the statistical model. We close with a discussion of a framework which has these properties.

LA MESURE DE L’INTERFÉRENCE DU CHIENDENT DANS L’ORGE

1982 ◽  
Vol 62 (1) ◽  
pp. 183-188 ◽  
Author(s):  
R. RIOUX
Keyword(s):  
Regression Analysis ◽  
Hordeum Vulgare ◽  
Linear Relationship ◽  
Linear Relation ◽  
Shoot Density ◽  
Yield Variability ◽  
Hordeum Vulgare L ◽  
The Mean ◽  
The Relationship ◽  
Agropyron Repens

Barley (Hordeum vulgare L. ’Champlain’) was grown with quackgrass (Agropyron repens (L.) Beauv.) at various densities for 3 yr. According to the regression analysis, a linear relation is appropriate to describe the relationship between yield of barley and biomass or density of quackgrass. A greater proportion of yield variability was explained by density (64%) than by biomass (40%). Density is then a better criterion than biomass to predict yield lost in barley. The linear relationship between barley yield and the shoot density of quackgrass is estimated by the following equation: yield barley = 345.3–0.5682 dens, quackgrass. An increase of 10 shoots/m2 in the mean density of quackgrass resulted in a mean loss of 6 g/m2 in the yield of barley.

Pedestrian Behavior at Signalized Intersection Crosswalks: Observational Study of Factors Associated with Distracted Walking, Pedestrian Violations, and Walking Speed

2018 ◽  
Vol 2672 (35) ◽  
pp. 1-12 ◽  
Author(s):  
Brendan J. Russo ◽  
Emmanuel James ◽  
Cristopher Y. Aguilar ◽  
Edward J. Smaglik
Keyword(s):  
Traffic Safety ◽  
Walking Speed ◽  
The United States ◽  
Ordinary Least Squares ◽  
Signalized Intersections ◽  
Video Data ◽  
High Definition ◽  
Pedestrian Behavior ◽  
Factors Associated ◽  
Walking Speeds

In the past two decades, cell phone and smartphone use in the United States has increased substantially. Although mobile phones provide a convenient way for people to communicate, the distraction caused by the use of these devices has led to unintended traffic safety and operational consequences. Although it is well recognized that distracted driving is extremely dangerous for all road users (including pedestrians), the potential impacts of distracted walking have not been as comprehensively studied. Although practitioners should design facilities with the safety, efficiency, and comfort of pedestrians in mind, it is still important to investigate certain pedestrian behaviors at existing facilities to minimize the risk of pedestrian–vehicle crashes, and to reduce behaviors that may unnecessarily increase delay at signalized intersections. To gain new insights into factors associated with distracted walking, pedestrian violations, and walking speed, 3,038 pedestrians were observed across four signalized intersections in New York and Arizona using high-definition video cameras. The video data were reduced and summarized, and an ordinary least squares (OLS) regression model was estimated to analyze factors affecting walking speeds. In addition, binary logit models were estimated to analyze both pedestrian distraction and pedestrian violations. Ultimately, several site- and pedestrian-specific variables were found to be significantly associated with pedestrian distraction, violation behavior, and walking speeds. The results provide important information for researchers, practitioners, and legislators, and may be useful in planning strategies to reduce or mitigate the impacts of pedestrian behavior that may be considered unsafe or potentially inefficient.

A study about the linearity of trends between extreme and mean temperatures in Argentina

2021 ◽  
Author(s):  
Solange Suli ◽  
Matilde Rusticucci ◽  
Soledad Collazo
Keyword(s):  
Linear Regression ◽  
Linear Relationship ◽  
Statistical Significance ◽  
Coefficient Of Determination ◽  
Maximum Temperature ◽  
Mean Temperature ◽  
Change In The Mean ◽  
The Mean ◽  
Student’S T ◽  
Cold Extremes

<p>Small variations in the mean state of the atmosphere can cause large changes in the frequency of extreme events. In order to deepen and extend previous results in time, in this work we analyzed the linear relationship between extreme and mean temperature (Τ) on a climate change scale in Argentina. Two monthly extreme indices, cold nights (TN10) and warm days (TX90), were calculated based on the quality-controlled daily minimum and maximum temperature data provided by the Argentine National Meteorological Service from 58 conventional weather stations located over Argentina in the 1977–2017 period. Subsequently, we evaluated the relationship between the linear trends of extremes and mean temperature on a seasonal basis (JFM, AMJ, JAS, and OND). Student's T-test was performed to analyze their statistical significance at 5%. Firstly, positive (negative) and significant linear regressions were found between TX90 (TN10) trends and mean temperature trends for the four studied seasons. Therefore, an increase in the Τ-trend maintains a linear relationship with significant increase (decrease) of warm days (cold nights). Moreover, we found that JFM was the one with the highest coefficient of determination (0.602 for hot extremes and 0.511 for cold extremes), implying that 60.2% (51.1%) of the TX90 (TN10) trend could be explained as a function of the Τ-trend by a linear regression. In addition, in the JFM (OND) quarter, the TX90 index increased by 7.02 (6.02) % of days each with a 1 ºC increase in the mean temperature. Likewise, the TN10 index decreased by 4.94 (and 4.99) % of days from a 1ºC increase in the mean temperature for the JFM (AMJ) quarter. Finally, it is worthwhile to highlight the uneven behavior between hot and cold extremes and the mean temperature. Specifically, it was observed that the slopes of the linear regression calculated for the TX90 index and Τ presented a higher absolute value than those registered for the TN10 index and Τ. Therefore, a change in the mean temperature affects hot extremes to a greater extent than cold ones in Argentina.</p>

Sexual behaviour in Euplotes raikovi is accompanied by pheromone-induced modifications of ionic currents

1999 ◽  
Vol 202 (4) ◽  
pp. 475-483
Author(s):  
C. Stock ◽  
T. Krüppel ◽  
G. Key ◽  
W. Lueken
Keyword(s):  
Mating Type ◽  
Sexual Behaviour ◽  
Walking Speed ◽  
Ionic Currents ◽  
Marine Ciliate ◽  
Na Current ◽  
Threefold Increase ◽  
The Mean ◽  
Euplotes Raikovi ◽  
K Currents

In the marine ciliate Euplotes raikovi, pheromone released by a complementary mating type (nonself pheromone) induces typical sexual behaviour, whereas self pheromone released by the same mating type generally has no effect. Nonself pheromone evokes a reduction of the mean walking speed by 66 %, a threefold increase in the frequency and duration of long-lasting rest phases and a doubling in the number of side-stepping reactions. Consequently, translocation is strongly reduced and the cells remain in a small area. This could increase the probability of finding a sexual partner for pair formation (conjugation). The usual pattern of rhythmic, spontaneous depolarizations controlling the walking rhythm is absent in nonself-pheromone-stimulated cells. The remaining depolarizations arise from a 4 mV hyperpolarized membrane potential and do not reach the usual amplitudes of 15–20 mV but only of 6–10 mV. In addition, the amplitudes of K+ currents are increased at depolarizations of more than 20 mV by at least 30 %. Hyperpolarization- and depolarization-activated Na+ current amplitudes are increased, whereas the Ca2+ current amplitude remains nearly unaffected.

scholarly journals Examining the Associations between Oases Soundscape Components and Walking Speed: Correlation or Causation?

2020 ◽  
Vol 12 (11) ◽  
pp. 4619
Author(s):  
Djihed Berkouk ◽  
Tallal Abdel Karim Bouzir ◽  
Luigi Maffei ◽  
Massimiliano Masullo
Keyword(s):  
Walking Speed ◽  
Significant Negative Correlation ◽  
Urban Settlements ◽  
Spearman Correlation Test ◽  
The Mean ◽  
Mode Of Transport ◽  
Post Hoc ◽  
One Way Anova

The feeling of calm and tranquillity provided by the oases of Algeria can disappear because of the outdated urbanization strategy which is based on the vehicle as a mode of transport. Walkability is one of the most adoptable sustainable strategies to reduce the negative mechanical transportation effects on the quality of life. This paper aimed to examine the correlation and the causation between oases soundscape components and walking speed. The methodology of this field study was based on an empirical approach at the urban settlements in three oases in Algeria. The correlation between walking speed and soundscape components was obtained through the use of the Spearman correlation test. A one-way ANOVA analysis was conducted to assess the effect of the soundscape components on walking speed. A post hoc Tukey test was adopted to explore the sound component that causes increased walking speed. In this study, no significant correlation was explored between the walking speed and the anthrophonical sounds. In contrast, the statistical analysis of the sound walks experience suggests a moderate and significant negative correlation between geophonical and biophonical sounds, with mean walking speed. The results showed that, the cause of the increase in the mean walking speed of the pedestrians is human sound. The findings suggest that further research is needed to focus on the long-term subjective investigation to explore the correlations and the effects between soundscape, walkability and walking speed.

Study about influence of doors’ opening degree on crowd evacuation based on simulation

2019 ◽  
Vol 30 (11) ◽  
pp. 1950096
Author(s):  
Yuanchun Ding ◽  
Falu Weng ◽  
Lizhong Yang
Keyword(s):  
Linear Relationship ◽  
Flow Rate ◽  
Saving Rate ◽  
Mean Square ◽  
Mean Flow ◽  
Time Saving ◽  
Evacuation Time ◽  
Crowd Evacuation ◽  
The Mean ◽  
Simulation Results

Based on simulation, the influence of the doors’ opening degree (DOD) on crowd evacuation is investigated in this paper. First of all, an evacuation model, which has one exit with two doors, is established by utilizing the software Pathfinder. Then, based on the obtained model, some evacuation scenarios are considered. The simulation results indicate, when the DOD is within 115∘–135∘, the time saving rate is more than 13%, and the maximum time saving rate is achieved when the DOD is 125∘. Furthermore, there is a linear relationship between the mean square error and the number of the evacuees. For a small number of evacuees, the total evacuation time is mainly influenced by the distributions of the evacuees, however, as the number of the evacuees increases, it is mainly influenced by the number of the evacuees. Moreover, when the DOD is 125∘, the mean flow rate per unit width (MFRPUW) decreases along with the increasing of exit’s width, however, it increases along with the increasing of exit’s width while the DOD is 180∘. Compared with the 180∘ DOD, the 125∘ DOD can always achieve a higher MFRPUW, and the narrower the exit is, the higher MFRPUW the 125∘ DOD achieves.

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