scholarly journals Multiparameter Stochastic Dynamics of Ecological Tourism System with Continuous Visitor Education Interventions

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Dongping Wei ◽  
Qunming Zheng ◽  
Shouwen Wen
Keyword(s):  
Differential Equation ◽  
Finite Time ◽  
Stochastic Dynamics ◽  
Equation Model ◽  
Small Time ◽  
Time Interval ◽  
Stochastic Dynamic ◽  
Small Time Interval ◽  
Education Interventions ◽  
Ecological Tourism

Management of ecological tourism in protected areas faces many challenges, with visitation-related resource degradations and cultural impacts being two of them. To address those issues, several strategies including regulations, site managements, and visitor education programs have been commonly used in China and other countries. This paper presents a multiparameter stochastic differential equation model of an Ecological Tourism System to study how the populations of stakeholders vary in a finite time. The solution of Ordinary Differential Equation of Ecological Tourism System reveals that the system collapses when there is a lack of visitor educational intervention. Hence, the Stochastic Dynamic of Ecological Tourism System is introduced to suppress the explosion of the system. But the simulation results of the Stochastic Dynamic of Ecological Tourism System show that the system is still unstable and chaos in some small time interval. The Multiparameters Stochastic Dynamics of Ecological Tourism System is proposed to improve the performance in this paper. The Multiparameters Stochastic Dynamics of Ecological Tourism System not only suppresses the explosion of the system in a finite time, but also keeps the populations of stakeholders in an acceptable level. In conclusion, the Ecological Tourism System develops steadily and sustainably when land managers employ effective visitor education intervention programs to deal with recreation impacts.

On diffracted wave fronts

1979 ◽  
Vol 84 (1-2) ◽  
pp. 35-54
Author(s):  
Peter Wolfe
Keyword(s):  
Wave Equation ◽  
Wave Front ◽  
Incident Wave ◽  
Spherical Wave ◽  
Small Time ◽  
Time Interval ◽  
Wave Fronts ◽  
Incident Plane ◽  
Small Time Interval ◽  
Propagation Of Singularities

SynopsisIn this paper we study the wave equation, in particular the propagation of discontinuities. Two problems are considered: diffraction of a normally incident plane pulse by a plane screen and diffraction of a spherical wave by the same screen. It is shown that when an incident wave front strikes the edge of the screen a diffracted wave front is produced. The discontinuities are precisely computed in a neighbourhood of the edge for a small time interval after the arrival of the incident wave front and a theorem of Hörmander on the propagation of singularities is used to obtain a globalresult.

GENERIC QUANTUM MARKOV SEMIGROUPS, CYCLE DECOMPOSITION AND DEVIATION FROM EQUILIBRIUM

2012 ◽  
Vol 15 (03) ◽  
pp. 1250016 ◽  
Author(s):  
FRANCO FAGNOLA ◽  
VERONICA UMANITÀ
Keyword(s):  
Small Time ◽  
Jump Processes ◽  
Time Interval ◽  
Markov Semigroup ◽  
Cycle Decomposition ◽  
Markov Jump ◽  
Partial Isometries ◽  
Small Time Interval ◽  
Positive Weights ◽  
The Difference

A generic quantum Markov semigroup [Formula: see text] of a d-level quantum open system with a faithful normal invariant state ρ admits a dual semigroup [Formula: see text] with respect to the scalar product induced by ρ. We show that the difference of the generators [Formula: see text] can be written as the sum of a derivation 2i[H, ⋅] and a weighted difference of automorphisms [Formula: see text] where [Formula: see text] is a family of cycles on the d levels of the system, wc are positive weights and [Formula: see text] are unitaries. This formula allows us to represent the deviation from equilibrium (in a "small" time interval) as the superposition of cycles of the system where the difference between the forward and backward evolution is written as the difference of a reversible evolution and its time reversal. Moreover, it generalises cycle decomposition of Markov jump processes. We also find a similar formula with partial isometries instead of unitaries.

The integral of geometric Brownian motion

2001 ◽  
Vol 33 (1) ◽  
pp. 223-241 ◽  
Author(s):  
Daniel Dufresne
Keyword(s):  
Differential Equation ◽  
Partial Differential Equation ◽  
Brownian Motion ◽  
Laplace Transform ◽  
Finite Time ◽  
Geometric Brownian Motion ◽  
Time Interval ◽  
Finite Time Interval ◽  
Special Cases ◽  
The Laplace Transform

This paper is about the probability law of the integral of geometric Brownian motion over a finite time interval. A partial differential equation is derived for the Laplace transform of the law of the reciprocal integral, and is shown to yield an expression for the density of the distribution. This expression has some advantages over the ones obtained previously, at least when the normalized drift of the Brownian motion is a non-negative integer. Bougerol's identity and a relationship between Brownian motions with opposite drifts may also be seen to be special cases of these results.

scholarly journals INVERSE PROBLEM FOR THE TIME-FRACTIONAL EULER-BERNOULLI BEAM EQUATION

2021 ◽  
Vol 26 (3) ◽  
pp. 503-518
Author(s):  
Ibrahim Tekin ◽  
He Yang
Keyword(s):  
Existence And Uniqueness ◽  
Numerical Experiments ◽  
Small Time ◽  
Beam Equation ◽  
Time Interval ◽  
Existence And Uniqueness Theorem ◽  
Bernoulli Beam ◽  
Additional Measurement ◽  
Small Time Interval ◽  
Euler Bernoulli Beam

In this paper, the classical Euler-Bernoulli beam equation is considered by utilizing fractional calculus. Such an equation is called the time-fractional EulerBernoulli beam equation. The problem of determining the time-dependent coefficient for the fractional Euler-Bernoulli beam equation with homogeneous boundary conditions and an additional measurement is considered, and the existence and uniqueness theorem of the solution is proved by means of the contraction principle on a sufficiently small time interval. Numerical experiments are also provided to verify the theoretical findings.

Gaussian approximation of some closed stochastic epidemic models

1977 ◽  
Vol 14 (02) ◽  
pp. 221-231
Author(s):  
Frank J. S. Wang
Keyword(s):  
Epidemic Model ◽  
Limit Theorems ◽  
Gaussian Approximation ◽  
Infected Individual ◽  
Small Time ◽  
Entire Population ◽  
Time Interval ◽  
Stochastic Epidemic Models ◽  
Small Time Interval ◽  
Stochastic Epidemic

A generalization of Bailey's general epidemic model is considered. In this generalized model, it is assumed that the probability of any particular susceptible becoming infected during the small time interval (t, t + Δt) is α(X(t))Δt + o(Δt), for some function a, where X(t) is the proportion of infected individuals in the entire population, the probability that an infected individual is infected for at least a length of time t is F(t), and recovered individuals are permanently immune from further attack. In this paper, central limit theorems are obtained for the proportion of infected individuals and the proportion of susceptibles in the entire population.

scholarly journals Differential Equation Model of the LLC Resonant Converter in the Ideal Case

Energies ◽  
2020 ◽  
Vol 13 (20) ◽  
pp. 5439
Author(s):  
Fang Li ◽  
Haodong Lei ◽  
Ruixiang Hao ◽  
Siwei Liu ◽  
Xiaojie You ◽  
...  
Keyword(s):  
Differential Equation ◽  
Equation Model ◽  
Time Interval ◽  
Resonant Converter ◽  
Differential Equation Model ◽  
Ideal Case ◽  
Operational Principle ◽  
Initial Values ◽  
Llc Resonant Converter ◽  
The Ideal

The LLC resonant converter has been widely used in direct current (DC) power supply applications. However, fundamental harmonic approximation or other simplified analyses will introduce inevitable deviations. Therefore, the differential equation model with numerical solution of the LLC converter is proposed in this paper based on the operational principle of the ideal case. In order to solve the differential equation, initial values need to be substituted. The accurate LLC model based on time interval analysis is very complicated and cannot be used. In this paper, solution methods of the initial values corresponding to different switching frequencies are proposed. The initial values can be solved conveniently. Furthermore, the voltage gain curve is modified by the idealized analysis. Lastly, all the above research is verified by PSIM simulation. The work is helpful to understand the operational principle of the LLC resonant converter.

scholarly journals Hardware Passwords Manager Based on Biometric Authentication

2021 ◽  
Vol 6 (1) ◽  
pp. 31
Author(s):  
Camelia Avram ◽  
Jose Machado ◽  
Adina Aştilean
Keyword(s):  
Small Time ◽  
Time Interval ◽  
Biometric Authentication ◽  
Secret Key ◽  
Security Systems ◽  
Web Browser ◽  
Cigarette Pack ◽  
Small Time Interval ◽  
Evolution Of Technology ◽  
Static Images

This paper presents a portable passwords manager which has a two-stage biometric-based access procedure. Data security using biometric methods was chosen as a variant of reduced complexity but was very effective in preventing cyber theft. The implementation of biometrics for the purpose of identification in high-security systems has become essential with the evolution of technology and the spike in identity theft. Unlike passwords or IDs, a biometric feature is an identifier that cannot be lost, stolen, or replicated, which provides biometric authentication systems with an increased level of security. During the first accessing step, the 3DPassManager portable device measures the heartbeat and uses fingerprint and iris features to realize a unique biometric-based authentication. While the specific characteristics of fingerprint and iris features are integrated to ensure that the person using the device is the rightful owner, the pulse is utilized to verify if previously acquired static images are not used. During the second accessing step, a password is generated based on fingerprint details, valid only for a small-time interval. The fingerprint is stored in a secret key with a 1024-bit length. Once access is allowed, the passwords are made available through an extension installed on the web browser. The device is the size of a cigarette pack and communicates with the PC by scanning a QR code. It is safe and was previously tested for dictionary and brute force attacks.

A nonlinear pseudoparabolic equation

1990 ◽  
Vol 114 (1-2) ◽  
pp. 119-133 ◽  
Author(s):  
Dang Dinh Ang ◽  
Tran Thanh
Keyword(s):  
Salient Feature ◽  
Small Time ◽  
Time Interval ◽  
Pseudoparabolic Equation ◽  
Nonhomogeneous Boundary ◽  
Small Time Interval ◽  
Nonhomogeneous Boundary Conditions ◽  
Image Position ◽  
Special Case ◽  
Nonlinear Pseudoparabolic Equation

SynopsisThe authors prove results on uniqueness and global existence of initial and boundary value problems for the nonlinear pseudoparabolic equationwith nonhomogeneous boundary conditions. A salient feature of the paper is that F and its partial derivatives are allowed to be unbounded. In the special case b(x, t)= α2 (a positive constant), it is proved that the corresponding solution uα, under appropriate conditions on the data (which are satisfied, for example, by the Benjamin–Bona–Mahony equation), uα→ u0 the solution corresponding to β = 0, on sufficiently small time interval. A result on the asymptotic behaviour of the solution is given for t → ∞.

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