scholarly journals Characteristic Time in Highly Motivated Movements of Children and Adults Through Bottlenecks

Author(s):  
Hongliu Li ◽  
Jun Zhang ◽  
Long Xia ◽  
Libing Yang ◽  
Weiguo Song ◽  
...  

Abstract Current codes for fire protection of buildings are mainly based on the movement of adults and neglect the movement characteristic of pre-school children. Having a profound comprehension of the difference between children and adults passing bottlenecks is of great help to improve the safety levels of preschool children. This paper presents an experimental study on the bottleneck flow of pre-school children in a room. The movement characteristics of children’s and adults’ bottleneck flow are investigated with two macroscopic properties: density and speed profiles as well as microscopic characteristic time: motion activation time, relaxation time, exit travel time and headway time. Arch-like density distributions are observed both for highly motivated children and adults, while the distance between the peak density region and the exit location is shorter for children and longer for adults. Children’s movement is less flexible manifested as longer motion activation time and longer relaxation time compared to that of adults. The findings from this study could enhance the understanding of crowd dynamics among the children population and provide supports for the scientific building design for children’s facilities.

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Hongliu Li ◽  
Jun Zhang ◽  
Long Xia ◽  
Libing Yang ◽  
Weiguo Song ◽  
...  

AbstractCurrent codes for fire protection of buildings are mainly based on the movement of adults and neglect the movement characteristic of pre-school children. Having a profound comprehension of the difference between children and adults passing bottlenecks is of great help to improve the safety levels of preschool children. This paper presents an experimental study on the bottleneck flow of pre-school children in a room. The movement characteristics of children’s and adults’ bottleneck flow are investigated with two macroscopic properties: density and speed profiles as well as microscopic characteristic time: motion activation time, relaxation time, exit travel time and time gap. Arch-like density distributions are observed both for highly motivated children and adults, while the distance between the peak density region and the exit location is shorter for children and longer for adults. Children’s movement is less flexible manifested as longer motion activation time and longer relaxation time compared to that of adults. The findings from this study could enhance the understanding of crowd dynamics among the children population and provide supports for the scientific building design for children’s facilities.


Water ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 292
Author(s):  
Kai Zhang ◽  
Meijian Bai ◽  
Yinong Li ◽  
Shaohui Zhang ◽  
Di Xu

The broadcast fertilization method is widely used under basin irrigation in China. A reasonable broadcast fertilization method can effectively improve application performance of fertilization and reduce pollution from non-point agricultural sources. In this study, firstly, a non-uniform broadcast fertilization method and a non-uniform application coefficient were proposed. The value of non-uniform application coefficient is defined in this paper. It represents the ratio of the difference between the maximum and the average fertilization amount of fertilizer applied on the basin surface to the average fertilization amount of fertilizer applied on the basin surface. Secondly, field experiments were conducted to study the movement characteristics of fertilizer under non-uniform broadcast fertilization for basin irrigation. Field experiment results showed that under the condition of basin irrigation, the non-uniform broadcast fertilization method could weaken the non-uniform distribution of fertilizer due to erosion and transport capacity of solid fertilizer by irrigation water flow, which could significantly improve the uniformity of soil solute content. Thirdly, the solute transport model for broadcast fertilization was corroborated by the field experiment results. The variation rule of fertilization performance with non-uniform application coefficient under different basin length and inflow rate was achieved by simulation. The simulation results showed that fertilization uniformity and fertilization storage efficiency increased first and then decreased with the increase of non-uniform application coefficient. In order to be practically applicable, suitable irrigation programs of non-uniform application coefficient under different basin length and inflow rate conditions were proposed by numerical simulation.


2004 ◽  
Vol 36 (6) ◽  
pp. 735-740 ◽  
Author(s):  
HELLE PULLMANN ◽  
JÜRI ALLIK ◽  
RICHARD LYNN

The Standard Progressive Matrices test was standardized in Estonia on a representative sample of 4874 schoolchildren aged from 7 to 19 years. When the IQ of Estonian children was expressed in relation to British and Icelandic norms, both demonstrated a similar sigmoid relationship. The youngest Estonian group scored higher than the British and Icelandic norms: after first grade, the score fell below 100 and remained lower until age 12, and after that age it increased above the mean level of these two comparison countries. The difference between the junior school children and the secondary school children may be due to schooling, sampling error or different trajectories of intellectual maturation in different populations. Systematic differences in the growth pattern suggest that the development of intellectual capacities proceeds at different rates and the maturation process can take longer in some populations than in others.


2011 ◽  
Vol 133 (4) ◽  
Author(s):  
Raed I. Bourisli ◽  
Adnan A. AlAnzi

This work aims at developing a closed-form correlation between key building design variables and its energy use. The results can be utilized during the initial design stages to assess the different building shapes and designs according to their expected energy use. Prototypical, 20-floor office buildings were used. The relative compactness, footprint area, projection factor, and window-to-wall ratio were changed and the resulting buildings performances were simulated. In total, 729 different office buildings were developed and simulated in order to provide the training cases for optimizing the correlation’s coefficients. Simulations were done using the VisualDOE TM software with a Typical Meteorological Year data file, Kuwait City, Kuwait. A real-coded genetic algorithm (GA) was used to optimize the coefficients of a proposed function that relates the energy use of a building to its four key parameters. The figure of merit was the difference in the ratio of the annual energy use of a building normalized by that of a reference building. The objective was to minimize the difference between the simulated results and the four-variable function trying to predict them. Results show that the real-coded GA was able to come up with a function that estimates the thermal performance of a proposed design with an accuracy of around 96%, based on the number of buildings tested. The goodness of fit, roughly represented by R2, ranged from 0.950 to 0.994. In terms of the effects of the various parameters, the area was found to have the smallest role among the design parameters. It was also found that the accuracy of the function suffers the most when high window-to-wall ratios are combined with low projection factors. In such cases, the energy use develops a potential optimum compactness. The proposed function (and methodology) will be a great tool for designers to inexpensively explore a wide range of alternatives and assess them in terms of their energy use efficiency. It will also be of great use to municipality officials and building codes authors.


2014 ◽  
Vol 18 (2) ◽  
pp. 167-176 ◽  
Author(s):  
David Leatherbarrow ◽  
Richard Wesley

The sun control device has to be on the outside of the building, an element of the facade, an element of architecture. And because this device is so important a part of our open architecture, it may develop into as characteristic a form as the Doric column.Victor Olgyay (1910–1970), a Hungarian architect who came to the United States in 1947 with his twin brother and collaborator, Aladár (1910–1963), is best known today as the author of Design with Climate: Bioclimatic Approach to Architectural Regionalism (1963), an important book often referenced in the environmental building design field [1]. As leaders in research in bioclimatic architecture from the early 1950s to the late 1960s, the Olgyay brothers could be considered the ‘fathers’ of contemporary environmental building design. Their research and publications laid the foundation for much of the building simulation software in use today. Other than the difference between working on graph paper and using computer-generated graphics, there is little difference between Autodesk's Ecotect Analysis (simulation and building energy analysis software) and the Olgyays' techniques for the analysis of environmental factors and graphical representation of climate. The manner in which the Olgyays established connections between building design and the science of climate laid the foundation for the development of environmental simulation, one of contemporary architecture's leading methods of form generation. Victor Olgyay's teaching, however, represents another kind of thinking, a broader concern for architecture, beyond energy performance. ‘The primary task of architecture,’ Olgyay announced to his students, ‘is to act in man's favour; to interpose itself between man and his natural surroundings in order to remove the environmental load from his shoulders.


PEDIATRICS ◽  
1979 ◽  
Vol 64 (6) ◽  
pp. 965-966
Author(s):  
Edwin L. Kendig

Another article in this issue of Pediatrics, "Assessment of Tuberculin Screening in an Urban Pediatric Clinic," (p 856) again focuses attention on a weighty question: Is routine use of the tuberculin test important? The authors have pointed out the difference in philosophy of the Center for Disease Control, and the American Academy of Pediatrics. The Center for Disease Control recommends that routine tuberculin testing for school children and other similar programs be abandoned if the yield of positive tuberculin reactions is less than 1%1; this recommendation is based on the assumption that discovery of cases at this low rate will not have epidemiologic impact (italics added).


1982 ◽  
Vol 50 (3) ◽  
pp. 768-770 ◽  
Author(s):  
Barbara K. Herndon ◽  
Mary D. Carpenter

Competitiveness and cooperativeness of children in the Northeast were compared to those same attitudes in the Midwest. 102 middle- to upper-class suburban public school children in Grades 2 through 6 were given the Minnesota School Affect Assessment. Contrary to former findings, competitiveness in all grades increased with age. There were main effects for sex for both attitudes. It is proposed that region of residence contributed to the difference found.


2020 ◽  
Author(s):  
Sobanawartiny Wijeakumar ◽  
Eva Rafetseder ◽  
Yee Lee Shing ◽  
Courtney McKay

Visual working memory (VWM) is reliably predictive of fluid intelligence and academic achievements. The objective of the current study was to investigate the nature of individual differences in pre-schoolers by examining the relationship between behaviour-brain function underlying VWM processing and parent-reported measures. We used a portable 8 x 8 channel functional near-infrared spectroscopy system to record from the frontal and parietal cortices of 4.5-year-old pre-school children (N=74) as they completed a colour change detection VWM task in their homes. Parents were asked to fill in questionnaires on temperament, academic aspirations, home environment, and life stress. Children were median-split into a low-performing (LP) and a high-performing (HP) group based on the number of items they could successfully remember during the task. LPs increasingly activated the bilateral frontal and parietal cortices with increasing load, whereas HPs showed no difference in activation across the loads. Our findings suggested that LPs recruited more neural resources when their VWM capacity was challenged. We employed mediation analyses to examine the association between the difference in activation between the highest and lowest loads, and variables from the questionnaires. The difference in activation in the right parietal cortex partially mediated the association between parent-reported stressful life events and VWM performance. Specifically, a higher number of stressful events was associated with lower VWM performance. Critically, our findings show that the association between VWM capacity, right parietal activation, and indicators of life stress is important to understand the nature of individual differences in VWM in pre-school children.


Author(s):  
Margarita K. Ermakova ◽  
Larisa P. Matveeva ◽  
Natalya R. Kapustina

Aim. To study the prevalence of bronchial asthma (BA) symptoms among elementary schoolchildren in the Udmurt Republic in the dynamics over 20 years. Materials and methods. A comparative study of the prevalence of BA was carried out. A questionnaire was administered to 2899 parents of first-graders, using the international standardized ISAAC program. Results. The prevalence of BA symptoms on the ISAAC program among elementary schoolchildren in the Udmurt Republic in 2020 was 7.70.2%, being significantly lower than in the previous studies of 2002 and 2009 (p0.001). Conclusion. There was a further downward trend in the prevalence of AD symptoms in younger schoolchildren. The difference between the current symptoms of the disease and the established diagnosis remained rather significant. Reliable (p10.001) increase in the number of children with dry cough, not related to cold, and children with bronchospasm connected with physical load was revealed.


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