Stochastic effects on a Hopf adaptive frequency oscillator

2021 ◽  
Vol 129 (22) ◽  
pp. 224901
Author(s):  
XiaoFu Li ◽  
Md. Raf E. Ul Shougat ◽  
Tushar Mollik ◽  
Aubrey N. Beal ◽  
Robert N. Dean ◽  
...  
Keyword(s):  
Stochastic Effects ◽  
Frequency Oscillator

Threshold square model of the dependence of radiation effects on radiation dose

2020 ◽  
Vol 89 ◽  
pp. 65-74
Author(s):  
A. G. Zavorotnyy ◽  
Keyword(s):  
Radiation Dose ◽  
Emergency Services ◽  
Least Squares Method ◽  
Threshold Model ◽  
Operating Conditions ◽  
Quadratic Model ◽  
Modern World ◽  
Stochastic Effects ◽  
Radiation Accidents ◽  
Increased Risk

Introduction. Operation of radiation hazardous facilities is a reality of the modern world, and the future of the world economy is impossible without the development of nuclear and radiation technologies. At the same time, the widespread use of atomic energy puts forward an important and responsible task of ensuring the safety of the population and the environment in conditions of an increased risk of exposure to ionizing radiation and radioactive substances. In accordance with clause 3.2.1 of the "Radiation Safety Standards NRB-99/2009", the planned increased exposure of persons involved in emergency rescue operations related to the elimination of the consequences of radiation accidents is allowed for men, as a rule, over 30 years old only with their voluntary written consent, after informing about possible radiation doses and health risks. Increased exposure refers to exposure in excess of the basic dose limits under controlled (normal) operating conditions of radiation sources. Goals and objectives. The aim of the study is to increase the functionality of emergency services and fire and rescue subdivisions to perform tasks as intended in the elimination of radiation accidents. The tasks include the construction and substantiation of a model that allows converting the risks of deterministic effects into stochastic effects risks. Methods. When calculating the probability of output of stochastic and deterministic effects depending on the radiation dose and developing a threshold quadratic model, the least squares method and the probabilistic-statistical method were used. Results and discussion. The article shows that a linear non-threshold model of the interaction of radiation with matter greatly overestimates the risk of a stochastic effect emerging at doses of radiation. For example, this overestimation is 8,13 at a dose of D = 0,2 Sv/year. In this regard, a threshold quadratic model has been developed and proposed to be replaced by a threshold quadratic model, which makes it possible to increase the planned irradiation of personnel of emergency services and fire and rescue units during the elimination of radiation accidents in an effective dose from 0,2 Sv to 0,57 Sv, moreover, the probability of emergence of stochastic effects P2 = 0,0084 remains the same for both models. Conclusions. An increase in the maximum permissible dose of radiation for personnel of emergency services and fire and rescue units from 0,2 Sv/year to 0,5 Sv/year will make it possible to increase the functionality of the emergency services and fire and rescue units to perform tasks as intended by 2,5 times when elimination of radiation accidents. For example, the scope of rescue operations may be increased from 100 %, performed at a dose of D = 0,2 Sv/year, to 250 %, performed at a dose of D = 0,5 Sv/year. Key words: emergency services, fire and rescue units, radiation accidents, irradiation, linear no-threshold model, threshold quadratic model.

Stochastic effects when determining the maximum RBMK channel power

Atomic Energy ◽  
2011 ◽  
Vol 110 (2) ◽  
pp. 73-76 ◽  
Author(s):  
A. V. Krayushkin ◽  
L. N. Zakharova
Keyword(s):  
Stochastic Effects ◽  
Channel Power

DOUBLY STOCHASTIC EFFECTS

2002 ◽  
Vol 02 (03) ◽  
pp. L157-L168
Author(s):  
A. ZAIKIN
Keyword(s):  
Nonlinear System ◽  
Stochastic Resonance ◽  
Additive Noise ◽  
Stochastic Effects ◽  
Doubly Stochastic

Doubly stochastic effects are effects in which an optimization of both multiplicative and additive noise intensities is necessary to induce ordering in a nonlinear system. I review recent achievements in the investigation of these effects and discuss two phenomena: doubly stochastic resonance and noise-induced propagation in monostable medium. Finally I discuss possible experimental implementations of these phenomena.

A Low-Fidelity Stochastic Model of Viral Spread in Aircraft to Assess Risk Mitigation Strategies

2021 ◽  
Author(s):  
Leigh McCue
Keyword(s):  
Large Scale ◽  
Risk Mitigation ◽  
Mitigation Strategies ◽  
Traffic Network ◽  
Computationally Efficient ◽  
Passenger Compartment ◽  
Stochastic Effects ◽  
Viral Spread ◽  
Risk Mitigation Strategies ◽  
Baseline Health

Abstract The purpose of this work is to develop a computationally efficient model of viral spread that can be utilized to better understand influences of stochastic factors on a large-scale system - such as the air traffic network. A particle-based model of passengers and seats aboard a single-cabin 737-800 is developed for use as a demonstration of concept on tracking the propagation of a virus through the aircraft's passenger compartment over multiple flights. The model is sufficiently computationally efficient so as to be viable for Monte Carlo simulation to capture various stochastic effects, such as number of passengers, number of initially sick passengers, seating locations of passengers, and baseline health of each passenger. The computational tool is then exercised in demonstration for assessing risk mitigation of intervention strategies, such as passenger-driven cleaning of seating environments and elimination of middle seating.

Genetic Drift in an Infinite Population: The Pseudohitchhiking Model

Genetics ◽  
2000 ◽  
Vol 155 (2) ◽  
pp. 909-919 ◽  
Author(s):  
John H Gillespie
Keyword(s):  
Genetic Drift ◽  
Stochastic Dynamics ◽  
Diffusion Theory ◽  
Stochastic Effects ◽  
Stochastic Force ◽  
Infinite Population ◽  
Sample Paths ◽  
Neutral Locus ◽  
Linked Selection ◽  
Number Of Branches

Abstract Selected substitutions at one locus can induce stochastic dynamics that resemble genetic drift at a closely linked neutral locus. The pseudohitchhiking model is a one-locus model that approximates these effects and can be used to describe the major consequences of linked selection. As the changes in neutral allele frequencies when hitchhiking are rapid, diffusion theory is not appropriate for studying neutral dynamics. A stationary distribution and some results on substitution processes are presented that use the theory of continuous-time Markov processes with discontinuous sample paths. The coalescent of the pseudohitchhiking model is shown to have a random number of branches at each node, which leads to a frequency spectrum that is different from that of the equilibrium neutral model. If genetic draft, the name given to these induced stochastic effects, is a more important stochastic force than genetic drift, then a number of paradoxes that have plagued population genetics disappear.

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