The Dynamics of Urban Spatial Structure: Some Exploratory Results Using Difference Equations and Bifurcation Theory

1981 ◽  
Vol 13 (12) ◽  
pp. 1473-1483 ◽  
Author(s):  
M Clarke ◽  
A G Wilson

It is demonstrated that a simple difference equation model, which exhibits complex bifurcation behaviour, can be used to represent change in urban retailing and residential systems. These submodels are combined to form a rudimentary dynamic model of urban spatial structure. A sample of exploratory results are presented for a 169-zone hypothetical system.


Urban Studies ◽  
2017 ◽  
Vol 55 (11) ◽  
pp. 2499-2521 ◽  
Author(s):  
Jangik Jin ◽  
Danya Kim

The objective of this study is to address two questions that are pertinent to the issue of transportation and urban spatial structure. First, we investigate whether the improvement of the subway system affects the spatial structure in the Seoul metropolitan area. Second, if so, we examine whether it contributes to the suburbanisation of population and employment or spatial concentration around the urban centre. To do so, we focus on the improvement of the subway system in Seoul metropolitan areas between 2000 and 2010 with micro population and employment data. Because of the interrelationship between population, employment and transportation, we control for the interplay between population, employment and subway network by using a simultaneous equation model. Our results provide several interesting findings. First, the improvement of the subway system plays an important role in changes in urban spatial structure. Second, the improvement of the subway system significantly affects job growth in the urban centre and subcentres in the city of Seoul. Third, the interrelationship between population, employment and public transportation generates redistributive effects that are substantially associated with urban growth and decline, and determine urban spatial structure.



1980 ◽  
Vol 74 (3) ◽  
pp. 651-669 ◽  
Author(s):  
John H. Aldrich

Recent campaigns have demonstrated the importance of dynamic elements in affecting the selection of presidential nominees. This paper develops a mathematical model to analyze these dynamics. The heart of the model is the assumed relationship between the ability to acquire resources and success in primaries and caucuses. The expenditure of resources leads to greater electoral success, while greater electoral success (in particular, exceeding expectations in a primary or caucus) leads to greater resource-gathering capabilities. A difference equation model of these relationships is proposed. I prove that any campaign of this form is necessarily unstable, which implies that most candidates will be “winnowed out” necessarily, while only a very few, but at least one candidate, will necessarily “have momentum.” This result is true whether there are two or many contenders. However, I also argue that the larger the number of candidates, the stronger the dynamic forces, and thus the more rapid the “winnowing out” process.



1975 ◽  
Vol 7 (8) ◽  
pp. 965-979 ◽  
Author(s):  
M A O Ayeni

Urban systems are dynamic and hence require predictive models that incorporate the element of time more explicitly. Comparative static models of the Lowry type may be embellished by the use of the entropy-maximizing methodology and by slight reformulations of the equations by the introduction of simple lags. The result is a quasi-dynamic or dynamic model of urban spatial structure. This is the first of two papers, in which the issues involved in the construction of predictive models are discussed and the equation systems of the model developed. The operationalization of the concepts and the empirical development of the model for a Nigerian city will be discussed in the paper to follow.



Author(s):  
Haibo Li ◽  
Xiaocong Xu ◽  
Xia Li ◽  
Shifa Ma ◽  
Honghui Zhang


2020 ◽  
Vol 23 (2) ◽  
pp. 571-590
Author(s):  
Mei Wang ◽  
Baoguo Jia ◽  
Feifei Du ◽  
Xiang Liu

AbstractIn this paper, an integral inequality and the fractional Halanay inequalities with bounded time delays in fractional difference are investigated. By these inequalities, the asymptotical stability conditions of Caputo and Riemann-Liouville fractional difference equation with bounded time delays are obtained. Several examples are presented to illustrate the results.



2020 ◽  
Vol 2020 (1) ◽  
Author(s):  
Stevo Stević ◽  
Bratislav Iričanin ◽  
Witold Kosmala ◽  
Zdeněk Šmarda

Abstract It is known that every solution to the second-order difference equation $x_{n}=x_{n-1}+x_{n-2}=0$ x n = x n − 1 + x n − 2 = 0 , $n\ge 2$ n ≥ 2 , can be written in the following form $x_{n}=x_{0}f_{n-1}+x_{1}f_{n}$ x n = x 0 f n − 1 + x 1 f n , where $f_{n}$ f n is the Fibonacci sequence. Here we find all the homogeneous linear difference equations with constant coefficients of any order whose general solution have a representation of a related form. We also present an interesting elementary procedure for finding a representation of general solution to any homogeneous linear difference equation with constant coefficients in terms of the coefficients of the equation, initial values, and an extension of the Fibonacci sequence. This is done for the case when all the roots of the characteristic polynomial associated with the equation are mutually different, and then it is shown that such obtained representation also holds in other cases. It is also shown that during application of the procedure the extension of the Fibonacci sequence appears naturally.



Author(s):  
Robert Stegliński

AbstractIn this work, we establish optimal Lyapunov-type inequalities for the second-order difference equation with p-Laplacian $$\begin{aligned} \Delta (\left| \Delta u(k-1)\right| ^{p-2}\Delta u(k-1))+a(k)\left| u(k)\right| ^{p-2}u(k)=0 \end{aligned}$$ Δ ( Δ u ( k - 1 ) p - 2 Δ u ( k - 1 ) ) + a ( k ) u ( k ) p - 2 u ( k ) = 0 with Dirichlet, Neumann, mixed, periodic and anti-periodic boundary conditions.



Sign in / Sign up

Export Citation Format

Share Document