An Urban Pattern Dynamics with Capital and Knowledge Accumulation

In this paper a dynamic model of urban pattern formation with endogenous knowledge and capital accumulation is proposed. The Alonso model is extended to include two of the most important dynamic forces for urban development—capital accumulatin and technological progress. The standard assumption of the existence of the central business district (CBD) is still accepted in this approach. It is assumed that two production sectors (industry and service) and one knowledge production sector (research institutions and university) are located at the CBD. First, a compact framework for analysing dynamic interactions of the three sectors and urban pattern formation is suggested. Then, the existence of stationary urban patterns is guaranteed and the stability conditions provided. Last, the effects of changes in government's research policy and some other parameters upon the system are examined.

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Analysis of Urban Effects in Oklahoma City using a Dense Surface Observing Network

Journal of Applied Meteorology and Climatology ◽

10.1175/jamc-d-15-0206.1 ◽

2016 ◽

Vol 55 (3) ◽

pp. 723-741 ◽

Cited By ~ 22

Author(s):

Xiao-Ming Hu ◽

Ming Xue ◽

Petra M. Klein ◽

Bradley G. Illston ◽

Sheng Chen

Keyword(s):

Metropolitan Area ◽

Land Surface ◽

Critical Role ◽

Central Business District ◽

Temperature Inversion ◽

Oklahoma City ◽

Near Surface ◽

Open Questions ◽

The Stability ◽

Business District

AbstractMany studies have investigated urban heat island (UHI) intensity for cities around the world, which is normally quantified as the temperature difference between urban location(s) and rural location(s). A few open questions still remain regarding the UHI, such as the spatial distribution of UHI intensity, temporal (including diurnal and seasonal) variation of UHI intensity, and the UHI formation mechanism. A dense network of atmospheric monitoring sites, known as the Oklahoma City (OKC) Micronet (OKCNET), was deployed in 2008 across the OKC metropolitan area. This study analyzes data from OKCNET in 2009 and 2010 to investigate OKC UHI at a subcity spatial scale for the first time. The UHI intensity exhibited large spatial variations over OKC. During both daytime and nighttime, the strongest UHI intensity is mostly confined around the central business district where land surface roughness is the highest in the OKC metropolitan area. These results do not support the roughness warming theory to explain the air temperature UHI in OKC. The UHI intensity of OKC increased prominently around the early evening transition (EET) and stayed at a fairly constant level throughout the night. The physical processes during the EET play a critical role in determining the nocturnal UHI intensity. The near-surface rural temperature inversion strength was a good indicator for nocturnal UHI intensity. As a consequence of the relatively weak near-surface rural inversion, the strongest nocturnal UHI in OKC was less likely to occur in summer. Other meteorological factors (e.g., wind speed and cloud) can affect the stability/depth of the nighttime boundary layer and can thus modulate nocturnal UHI intensity.

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Pattern Dynamics in a Spatial Predator-Prey System with Allee Effect

Abstract and Applied Analysis ◽

10.1155/2013/921879 ◽

2013 ◽

Vol 2013 ◽

pp. 1-12 ◽

Cited By ~ 6

Author(s):

Gui-Quan Sun ◽

Li Li ◽

Zhen Jin ◽

Zi-Ke Zhang ◽

Tao Zhou

Keyword(s):

Pattern Formation ◽

Mortality Rate ◽

Allee Effect ◽

Spatial Dynamics ◽

Spiral Wave ◽

Amplitude Equations ◽

Predator Prey ◽

Pattern Dynamics ◽

Prey System ◽

The Stability

We investigate the spatial dynamics of a predator-prey system with Allee effect. By using bifurcation analysis, the exact Turing domain is found in the parameters space. Furthermore, we obtain the amplitude equations and determine the stability of different patterns. In Turing space, it is found that predator-prey systems with Allee effect have rich dynamics. Our results indicate that predator mortality plays an important role in the pattern formation of populations. More specifically, as predator mortality rate increases, coexistence of spotted and stripe patterns, stripe patterns, spotted patterns, and spiral wave emerge successively. The results enrich the finding in the spatial predator-prey systems well.

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