scholarly journals A Hybrid Stochastic Model for Characterization of Subsurface Heterogeneity.(Dept.C)

2021 ◽  
Vol 22 (3) ◽  
pp. 34-44
Author(s):  
Amr ElFeki
Keyword(s):  
Stochastic Model ◽  
Subsurface Heterogeneity

Characterization of HIV infection and seroconversion by a stochastic model of the HIV epidemic

1995 ◽  
Vol 126 (1) ◽  
pp. 81-123 ◽  
Author(s):  
Wai-Yuan Tan ◽  
Sho Rong Lee ◽  
Si Chin Tang
Keyword(s):  
Hiv Infection ◽  
Stochastic Model ◽  
Hiv Epidemic

scholarly journals Stochastic Dosimetry for the Assessment of Children Exposure to Uniform 50 Hz Magnetic Field with Uncertain Orientation

2017 ◽  
Vol 2017 ◽  
pp. 1-14 ◽  
Author(s):  
E. Chiaramello ◽  
S. Fiocchi ◽  
P. Ravazzani ◽  
M. Parazzini
Keyword(s):  
Magnetic Field ◽  
Central Nervous System ◽  
Nervous System ◽  
Electric Field ◽  
Stochastic Model ◽  
Significant Difference ◽  
The Central Nervous System ◽  
Children Exposure ◽  
The Magnetic Field

This study focused on the evaluation of the exposure of children aging from five to fourteen years to 50 Hz homogenous magnetic field uncertain orientation using stochastic dosimetry. Surrogate models allowed assessing how the variation of the orientation of the magnetic field influenced the induced electric field in each tissue of the central nervous system (CNS) and in the peripheral nervous system (PNS) of children. Results showed that the electric field induced in CNS and PNS tissues of children were within the ICNIRP basic restrictions for general public and that no significant difference was found in the level of exposure of children of different ages when considering 10000 possible orientations of the magnetic field. A “mean stochastic model,” useful to estimate the level of exposure in each tissue of a representative child in the range of age from five to fourteen years, was developed. In conclusion, this study was useful to deepen knowledge about the ELF-MF exposure, including the evaluation of variable and uncertain conditions, thus representing a step towards a more realistic characterization of the exposure to EMF.

A stochastic description of temporal daily rainfall patterns

1984 ◽  
Vol 11 (2) ◽  
pp. 234-238 ◽  
Author(s):  
Van-Thanh-Van Nguyen
Keyword(s):  
Markov Chain ◽  
Stochastic Model ◽  
Exponential Distribution ◽  
Daily Rainfall ◽  
Stochastic Approach ◽  
Rainfall Event ◽  
Event Duration ◽  
Rainfall Occurrence ◽  
Rainfall Patterns

A stochastic approach to characterization of temporal rainfall patterns is proposed wherein a rainfall event is defined as an unbroken sequence of consecutive daily rainfalls. A stochastic model is developed to determine the probability distribution of cumulative rainfall amounts at the end of each day within a total rainfall event duration of n days. The model is structured such that the distribution of daily rainfall depths can be approximated by an exponential distribution and the rainfall occurrence process can be described by a first-order stationary Markov chain. An illustrative example was presented, using a 32-year daily rainfall record at Dorval Airport on Montreal Island. The results of this example have demonstrated the adequacy and descriptive capabilities of the model. It can be concluded that the methodology proposed here seems to be more general and more flexible than those that have been used in previous investigations. Key words: daily rainfall process, temporal rainfall pattern, stochastic model, stochastic hydrology, exponential distribution, Markov chain.

A stochastic model for daily residential water demand

2016 ◽  
Vol 16 (6) ◽  
pp. 1753-1767 ◽  
Author(s):  
Rudy Gargano ◽  
Carla Tricarico ◽  
Giuseppe del Giudice ◽  
Francesco Granata
Keyword(s):  
Stochastic Model ◽  
Water Use ◽  
Water Demand ◽  
Distribution Systems ◽  
Water Distribution ◽  
Distribution Networks ◽  
Cumulative Distribution ◽  
Residential Water Demand ◽  
Residential Water

Residential water demand is a random variable which influences greatly the performance of municipal water distribution systems (WDSs). The water request at network nodes reflects the behavior of the residential users, and a proper characterization of their water use habits is vital for the hydraulic system modeling. This study presents a stochastic approach for the characterization of the daily residential water use. The proposed methodology considers a unique probabilistic distribution – mixed distribution – for any time during the day, and thus for any entity of the water demanded by the users. This distribution is obtained by the merging of two cumulative distribution functions taking into account the spike of the cumulative frequencies for the null requests. The methodology has been tested on three real water distribution networks, where the water use habits are different. Experimental relations are given to estimate the parameters of the proposed stochastic model in relation to the users number and to the average daily trend. Numerical examples for a practical application have shown the effectiveness of the proposed approach in order to generate the time series for the residential water demand.

Morphological Characterization of Mycobacteriophage R1

1974 ◽  
Vol 32 ◽  
pp. 254-255
Author(s):  
B. L. Soloff ◽  
T. A. Rado
Keyword(s):  
Carbon Source ◽  
Stationary Phase ◽  
Growth Phase ◽  
Minimal Medium ◽  
Morphological Characterization ◽  
Logarithmic Growth Phase ◽  
Complete Lysis ◽  
Lysogenic Culture ◽  
Logarithmic Growth

Mycobacteriophage R1 was originally isolated from a lysogenic culture of M. butyricum. The virus was propagated on a leucine-requiring derivative of M. smegmatis, 607 leu−, isolated by nitrosoguanidine mutagenesis of typestrain ATCC 607. Growth was accomplished in a minimal medium containing glycerol and glucose as carbon source and enriched by the addition of 80 μg/ ml L-leucine. Bacteria in early logarithmic growth phase were infected with virus at a multiplicity of 5, and incubated with aeration for 8 hours. The partially lysed suspension was diluted 1:10 in growth medium and incubated for a further 8 hours. This permitted stationary phase cells to re-enter logarithmic growth and resulted in complete lysis of the culture.

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