scholarly journals Local average height distribution of fluctuating interfaces

2017 ◽  
Vol 95 (1) ◽  
Author(s):  
Naftali R. Smith ◽  
Baruch Meerson ◽  
Pavel V. Sasorov
Keyword(s):  
Average Height ◽  
Height Distribution ◽  
Fluctuating Interfaces ◽  
Local Average

A Topographic Drag Closure Built on an Analytical Base Flux

2005 ◽  
Vol 62 (7) ◽  
pp. 2302-2315 ◽  
Author(s):  
Stephen T. Garner
Keyword(s):  
Dimensional Analysis ◽  
Wave Train ◽  
Average Height ◽  
Height Distribution ◽  
Ocean Tides ◽  
Linear Solution ◽  
Flow Over Topography ◽  
Linear Drag ◽  
The Vertical Distribution ◽  
State Assumption

Abstract Topographic drag schemes depend on grid-scale representations of the average height, width, and orientation of the subgrid topography. Until now, these representations have been based on a combination of statistics and dimensional analysis. However, under certain physical assumptions, linear analysis provides the exact amplitude and orientation of the drag for arbitrary topography. The author proposes a computationally practical closure based on this analysis. Also proposed is a nonlinear correction for nonpropagating base flux. This is patterned after existing schemes but is better constrained to match the linear solution because it assumes a correlation between mountain height and width. When the correction is interpreted as a formula for the transition to saturation in the wave train, it also provides a way of estimating the vertical distribution of the momentum forcing. The explicit subgrid height distribution causes a natural broadening of the layers experiencing the forcing. Linear drag due to simple oscillating flow over topography, which is relevant to ocean tides, has almost the same form as for the stationary atmospheric problem. However, dimensional analysis suggests that the nonpropagating drag in this situation is mostly due to topographic length scales that are small enough to keep the steady-state assumption satisfied.

scholarly journals SPECTRAL DENSITY SCALING OF FLUCTUATING INTERFACES

2013 ◽  
Vol 27 (27) ◽  
pp. 1350197 ◽  
Author(s):  
HYUN-JOO KIM ◽  
DOIL JUNG
Keyword(s):  
Spectral Density ◽  
Random Matrix Theory ◽  
Random Matrix ◽  
Matrix Theory ◽  
Scaling Function ◽  
System Size ◽  
Average Height ◽  
Largest Eigenvalues ◽  
Fluctuating Interfaces ◽  
The Scaling Function

In this paper, covariance matrices of heights measured relative to the average height of growing self-affine surfaces in the steady state are investigated in the framework of random matrix theory. We show that the spectral density of the covariance matrix scales as ρ(λ) ~ λ-ν deviating from the prediction of random matrix theory and has a scaling form, ρ(λ, L) = λ-ν f(λ/Lϕ) for the lateral system size L, where the scaling function f(x) approaches a constant for λ ≪ Lϕ and zero for Lϕ≪λ< λ max . The values of exponents obtained by numerical simulations are ν ≈ 1.70 and ϕ ≈ 1.51 for the Edward–Wilkinson class and ν ≈ 1.61 and ϕ ≈ 1.76 for the Kardar–Parisi–Zhang class, respectively. The distribution of the largest eigenvalues follows a scaling form as ρ(λ max , L) = 1/Lb f max ((λ max - La)/Lb), which is different from the Tracy–Widom distribution of random matrix theory while the exponents a and b are given by the same values for the two different classes.

scholarly journals Growth Delay and Height-Age: Alternative Indicators of Population Health Based on Child Height Distributions

2020 ◽  
Vol 4 (Supplement_2) ◽  
pp. 865-865
Author(s):  
Liina Mansukoski ◽  
Huma Qamar ◽  
Ashley Aimone ◽  
Nandita Perumal ◽  
Diego Bassani ◽  
...  
Keyword(s):  
Chronological Age ◽  
Growth Delay ◽  
Demographic And Health Surveys ◽  
Average Height ◽  
Height Distribution ◽  
Population Mean ◽  
Child Height ◽  
Population Average ◽  
Z Scores ◽  
Height For Age

Abstract Objectives Alternative indicators may enrich the description of population height distributions alongside age- and sex-standardised height-for-age Z-scores (HAZ) and prevalence of under-5 stunting. We propose two indicators of linear growth that account for the partial biological dependency of child height on growth tempo: height-age, which is the age at which the observed height distribution would be normal; and, population ‘growth delay’, which is the difference between height-age and chronological age. Methods Using data from 145 Demographic and Health Surveys from 64 countries (2000–2018), population-average height ages were estimated by transforming child heights (in cm) into WHO Growth Standard (WHO-GS) HAZ-values. Population mean HAZ at a given age was estimated using predictions from linear spline models, where HAZ was regressed on age for each survey. Mean HAZ values were back-transformed to heights using WHO-GS-LMS parameters to identify the age at which the observed population mean height was closest to WHO-GS-median height (referred to as the height-age). Growth delay was computed by subtracting height-age from chronological age. Primary analyses were based on height-age at 5 years (60 months) chronological age. For comparison, mean height-for-age differences (HAD) and under 5-stunting prevalence (in %) were calculated. Results In the most recent surveys for each country (N = 64), height-age at 60 months chronological age ranged from 40.9–58.1 months, such that growth delay ranged from 1.9–19.1 months. Mean HAZ ranged from −2.32 to −0.22 Z-scores, and under-5 stunting prevalence from 7.1–56.0%. A comparison of growth delay at 5-years, under-5 stunting prevalence and mean HAZ at 5-years showed that countries were similarly ranked by all indicators. Country case studies showed some differences in the trajectories of growth delay by age, versus mean HAZ or HAD by age. Conclusions Population-average height-age and growth delay, derived from anthropometric surveys, are biologically consistent and interpretable indicators of child health and nutritional status. These indicators may be preferred over mean HAZ or stunting prevalence for conveying the critical role of growth tempo and later catch-up potential in height. Funding Sources SickKids Child Growth and Development Fellowship.

scholarly journals The height of watermelons with wall - Extended Abstract

2007 ◽  
Vol DMTCS Proceedings vol. AH,... (Proceedings) ◽  
Author(s):  
Thomas Feierl
Keyword(s):  
Average Height ◽  
Height Distribution ◽  
Famous Result ◽  
Plane Trees ◽  
International Audience ◽  
De Bruijn

International audience We derive asymptotics for the moments of the height distribution of watermelons with $p$ branches with wall. This generalises a famous result by de Bruijn, Knuth and Rice on the average height of planted plane trees, and a result by Fulmek on the average height of watermelons with two branches.

Use of local average subdivision to characterize marine mineral reserves—A conceptual framework

CIM Journal ◽  
2015 ◽  
Vol 6 (3) ◽  
pp. 157-167
Author(s):  
T. Wambeke ◽  
M. Alvarez Grima ◽  
G. A. Fenton ◽  
J. Benndorf ◽  
A. Vervoort
Keyword(s):  
Conceptual Framework ◽  
Local Average ◽  
Mineral Reserves

Study regarding the bio-motor level and health of children from gymnasium level

2020 ◽  
pp. 1-9
Author(s):  
Dan Alexandru Szabo
Keyword(s):  
Body Mass Index ◽  
Body Mass ◽  
Anthropometric Measurements ◽  
Average Height ◽  
Mathematical Methods ◽  
Health Development ◽  
Health Level ◽  
Class Level ◽  
Flat Feet ◽  
Weight Problems

The investigation started from the need to find the level of bio-motor and health development in our Gymnasium School “Unirea” from Târgu Mureş. The research was also focused on discovering the children with BMI problems and finding the link between obesity and apparition of flat feet, spin and knee deficiencies. The methods of research were mainly experimental, we used anthropometric measurements of height, weight, body mass index and analyzed the parameters using statically and mathematical methods. The location of the study was the gymnasium level of the National College “Unirea” from Târgu Mureş, and involved 16 selected children with an average age 12.69 years old, 4 children with weight problems selected from every class level. The results of the investigation showed that the average height of the sample was 162.7 cm, weight 71 kg and a BMI average of 26.6. The BMI analyzed showed that obesity is an important factor in the apparition of other deficiencies, among students that were measured we also found 5 cases of kyphosis, 5 of scoliosis and 6 cases of flat feet. Conclusions of the investigation showed that BMI in youth is an important parameter in establishing the health level of children from gymnasium level and in preventing the apparition of the spine and feet deficiencies.

Productivity and Environmental Role of Forest Shelterbelts of Robinia pseudoacacia L. of the Kuban Lowland

2020 ◽  
pp. 88-97
Author(s):  
V.V. Tanyukevich ◽  
◽  
S.V. Tyurin ◽  
D.V. Khmeleva ◽  
A.A. Kvasha ◽  
...  
Keyword(s):  
Agricultural Land ◽  
Land Reclamation ◽  
Poa Pratensis ◽  
Robinia Pseudoacacia ◽  
Average Height ◽  
Middle Aged ◽  
Aboveground Phytomass ◽  
Robinia Pseudoacacia L ◽  
Young Growth

Works on protective afforestation are carried out in order to protect agricultural land from degradation processes, as well as to improve the microclimate of land. The research purpose is to study the bioproductivity and environmental role of Robinia pseudoacacia L. forest shelterbelts in the conditions of the Kuban lowland. The approved and generally accepted methods of forest valuation, forest land reclamation, botany, and mathematical statistics were applied. Plantings were created according to the standard technology for the steppe zone of the Russian Federation. The area of forest shelterbelts is 62.4 ths ha, including 5 % of the young growth (I state class), 80 % of middle-aged forest plantings (II state class), 10 % of maturing plantings (II state class), 5 % of mature and overmature plantings (III state class). Living ground cover is formed by the following species: Koeleria pyramidata L., Poa pratensis L., Festuca pratensis H., Elytrígia repens L., Dactylis glomerata L., and Phlum pratense L. Aboveground phytomass is 100–300 g/m2; height is 25–32 cm. Plantings are characterized by the quality classes: young growth – I and II; middle-aged and maturing – III; mature and overmature – IV. At the age of natural maturity (70 years), the Robinia trunk reaches the average height of 15.1 m with the average diameter of 22.1 cm. The total stock of wood reaches 18, (ths m3), including (ths m3): young growth – 68 (ths m3); middleaged plantings – 14,871 (ths m3); maturing plantings – 2,187 (ths m3); mature and overmature plantings – 1,314 (ths m3). Aboveground phytomass in young growth is 20.2 t/ha; in mature and overmature plantings it is 391.2 t/ha. In the region it is estimated at 17,070 ths t, including (ths t): young growth – 64; middle-aged plantings – 13,753; maturing plantings – 2,032; mature and overmature plantings – 1,221. The share of stem mass reaches 84.5–80.8 %; woody greenery – 4.2–1.5 %; branches – 11.3–17.7 %. Recalculation coefficients of the stock into aboveground phytomass are the following for: young growth – 0.936; mature and overmature forest shelterbelts – 0.929. Phytosaturation of forest shelterbelts varies within 0.314–2.474 kg/m3. Forest shelterbelts have accumulated 8,534 ths t of carbon, which is estimated at 145.1 mln dollars. The sphere of application of the research results is the Krasnodar Krai forestry, which is recommended to create an additional 60 ths ha of forest shelterbelts, which will provide a normative protective forest cover of arable land of 5 % and annual carbon sequestration up to 3.4 t/ha.

Silvicultural characteristics of a Scots pine stand on drift sands

1992 ◽  
Vol 57 ◽  
Author(s):  
D. Maddelein ◽  
N. Lust
Keyword(s):  
Scots Pine ◽  
Mixed Forest ◽  
Rotation Period ◽  
Average Height ◽  
Indigenous Species ◽  
Pedunculate Oak ◽  
Black Cherry ◽  
Humus Layer ◽  
Pine Seedlings ◽  
Pine Regeneration

The  study of a seventy years old stand of Scots pine on drift sands proves that  Scots pine growth on these sites was and is still relatively good: average  diameter 27.6 cm, average height 19.4 m, standing volume 213 m3 and an annual increment  of 4.9 m3.ha-1.yr-1. All Scots pines  belong to the upper storey. Yet considerable differences in crown development  and vitality are observed. The current growth rate and the spontaneous  settlement of pine seedlings under canopy show the ideal conditions for the  creation of a high forest with reserves. Anyway a rotation period of more  than 70 years is recommendable.     On several places a consolidated regeneration of Scots pine seedlings under  canopy occur. Groups with a stem number of 700 to 3,500 seedlings per are, ranging  in age from 3 to 11 years and in height from 10 to 170 cm, are present. This  Scots pine regeneration has developed in a normal mor humus layer and in a  dense Deschampsia mat.      Broadleaved regeneration is not so abundant, and consists for 75 % of black  cherry. Absence of seed trees, browsing damage and the exclusive character of  black cherry are the limiting factors for the installation and survival of  valuable indigenous species, such as pedunculate oak.     Provided that black cherry is removed and that the regeneration is  protected against wild damage, it is possible to create a mixed forest  dominated by Scots pine but with a considerable admixture of indigenous  broadleaved trees. However, if black cherry will not be sufficiently  controlled, it can be expected that in a first phase black cherry will  dominate the understorey, that it will prevent the regeneration of all other  species and that, very soon, it will form an almost single-species dominated  stage in forest succession.

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