Hasil untuk "Metropolitan areas"

S. Pickett, M. Cadenasso, J. Grove et al.

G. Luber, M. Mcgeehin

Chang-tai Hsieh, E. Moretti

We quantify the amount of spatial misallocation of labor across US cities and its aggregate costs. Misallocation arises because high productivity cities like New York and the San Francisco Bay Area have adopted stringent restrictions to new housing supply, effectively limiting the number of workers who have access to such high productivity. Using a spatial equilibrium model and data from 220 metropolitan areas we find that these constraints lowered aggregate US growth by 36 percent from 1964 to 2009. (JEL E23, J24, J31, R23, R31)

J. Onyx, P. Bullen

W. Schlenger, J. Caddell, Lori Ebert et al.

James E. Rauch

Based on recent theoretical developments I argue that the average level of human capital is a local public good. Cities with higher average levels of human capital should therefore have higher wages and higher land rents. After conditioning on the characteristics of individual workers and dwellings, this prediction is supported by data for Standard Metropolitan Statistical Areas (SMSAs) in the United States, where the SMSA average levels of formal education and work experience are used as proxies for the average level of human capital. I evaluate the alternative explanations of omitted SMSA variables and self-selection. I conclude by computing an estimate of the effect of an additional year of average education on total factor productivity.

K. Land, P. Mccall, Lawrence E. Cohen

P. Edin, P. Fredriksson, Olof Åslund

Jesse M. Shapiro

From 1940 to 1990, a 10% increase in a metropolitan area's concentration of college-educated residents was associated with a 0.8% increase in subsequent employment growth. Instrumental variables estimates support a causal relationship between college graduates and employment growth, but show no evidence of an effect of high school graduates. Using data on growth in wages, rents, and house values, I calibrate a neoclassical city growth model and find that roughly 60% of the employment growth effect of college graduates is due to enhanced productivity growth, the rest being caused by growth in the quality of life. This finding contrasts with the common argument that human capital generates employment growth in urban areas solely through changes in productivity.

S. Shim, Mary Ann Eastlick, S. Lotz et al.

Peter M. Mieszkowski, E. Mills

Ahmad Harakan, Yusuf Adam Hilman, A. Junaedi Karso et al.

IntroductionUrban fire disasters pose a significant challenge to city resilience and sustainability, particularly in the Global South, where rapid urbanization exacerbates existing vulnerabilities. In Indonesia, recurring fire incidents, ranging from forest fires to residential fires in densely populated areas, highlight the urgent need for effective fire disaster management. This study focuses on Makassar, a metropolitan city facing increasing fire risks due to high population density, aging infrastructure, and limited preparedness.MethodsThis research employs a qualitative approach, drawing on fire incident data from 2018 to 2023, interviews, and historical analysis to assess collaboration mechanisms in fire disaster management. The study examines inter-agency coordination, communication gaps, and resource allocation issues, which hinder effective disaster response.ResultsFindings reveal a concerning rise in fire incidents in Makassar, leading to significant socio-economic impacts, including fatalities and property damage. The study identifies critical deficiencies in inter-agency collaboration, largely due to differing organizational cultures, inadequate coordination mechanisms, and resource distribution challenges.Discussion and conclusionBy evaluating global fire resilience models, the research proposes a governance framework to enhance inter-agency cooperation in Makassar. The study advocates for integrated strategies, combining infrastructure development with community-driven initiatives to strengthen disaster prevention, response, and recovery. These findings contribute to sustainable urban development, ensuring greater resilience against fire disasters in rapidly urbanizing cities.

Francis Chia Hui Lin

The relief from the COVID-19 pandemic today is globally phenomenal. However, its architectural representation still suggests dramatic variables caused by different localities. Conspicuously, the imposition of social distancing has been displayed very differently in different places upon architectural treatment. This paper argues that such a built scenario can be understood through a theorisation of a “postcolonial-urban complex” that integrates architecture’s inevitable engagement in the discourses of form and knowledge and the postcolonial values registered in spatial signification. The postcolonial-urban complex refers to a series of leads to a subject position of the post-pandemic-built environment, including a sense of counter-dualism, the dynamics of domination and the reified subjectivation. Existing scholarship of architectural and urban studies hence needs a thorough re-examination into the epistemic suitability for responding the immediate historicity. This paper argues that such a demand has become sensible from the recent situation of Asia and its architecture and urbanism – the engagement of some Asian metropolitan areas in shaping ephemeral and micro-geopolitical forms reacting to the limits caused by social distancing give evidence. To further consolidate such argumentation, this paper intends to examine semiotically and empirically the post-pandemic architectural treatment in Taipei, Taiwan, as a preliminary yet critical pilot study.

Zoyeb Mohamed Zia, Mehboob Asrar Sheriff

Laundry wastewater comprises a complex mixture of organic and inorganic pollutants posing significant threats to aquatic ecosystems and public health. This study investigates the performance of β-chitosan derived from squid pen waste as a sustainable biopolymer for the remediation of domestic laundry effluent collected from high-density residential areas within the Chennai metropolitan region, India. The treatment efficacy of β-chitosan was evaluated at three concentrations (2 %, 4 %, and 6 % w/v) through systematic assessment of Biochemical Oxygen Demand (BOD) and Chemical Oxygen Demand (COD) reductions across ten sites. The 4 % β-chitosan concentration consistently achieved optimal removal efficiencies, reducing BOD by 52.1–69.5 % and COD by 57.8–62.9 %, outperforming both lower and higher dosages. The reduced effectiveness at 6 % was attributed to molecular aggregation that limited available binding sites, while 2 % was insufficient to address pollutant loads. These findings demonstrate β-chitosan’s potential as an effective, biodegradable coagulant for wastewater treatment, contributing to circular economy approaches by valorizing marine biowaste. The robust and consistent treatment performance across diverse pollutant loads supports its applicability in sustainable urban wastewater management, offering an environmentally friendly alternative to conventional chemical treatments.

Fabrice Baudoin, Teije Kuijper, Jing Wang

We show that a Brownian motion on the quaternionic full flag manifold can be represented as a matrix-valued diffusion obtained in a simple way from a symplectic Brownian motion. By relating its radial dynamics to the Brownian motion on the quaternionic sphere, an explicit formula for the characteristic function of the joint distribution of the quaternionic stochastic areas is obtained. The limit law of these quaternionic stochastic areas is shown to be a multivariate normal distribution with zero mean and non-diagonal covariance matrix. These results are subsequently applied to establish new results about simultaneous quaternionic windings on the quaternionic spheres.

Egor Illarionov, Andrey Tlatov, Ivan Berezin et al.

Coronal holes (CHs) are widely considered as the main sources of high-speed solar wind streams. We validate this thesis comparing the smoothed time series of solar wind speed measured by Advanced Composition Explorer (ACE) and various indices of CH areas constructed from the CH catalog compiled at the Kislovodsk Mountain Astronomical Station for the period 2010-2025. The main result is that we find specific indices of CH areas that give a strong correlation with smoothed solar wind speed variations. As an example, 1-year averaged areas of CHs located within 30 degrees of the solar equator yield a correlation of 0.9 with 1-year averaged solar wind speed. This strong correlation is a feature of the particular CH catalog, and considering an alternative CH catalog obtained using the Spatial Possibilistic Clustering Algorithm (SPoCA) from the Heliophysics Event Knowledgebase (HEK), the same index provides a correlation of only 0.3. Although the fact that the correlation significantly depends on the catalog requires a separate discussion, we conclude that if some of the catalogs can be used to construct a reliable indicator of solar wind speed variations, then this methodology should be maintained further. Additionally, we present time-latitude diagrams of rolling correlation between CHs areas and solar wind speed, which, in our opinion, can be used to reveal source CHs for high-speed solar wind streams.

Muhammad Umair Danish, Madhushan Buwaneswaran, Tehara Fonseka et al.

The increasing impact of human-induced climate change and unplanned urban constructions has increased flooding incidents in recent years. Accurate identification of flooded areas is crucial for effective disaster management and urban planning. While few works have utilized convolutional neural networks and transformer-based semantic segmentation techniques for identifying flooded areas from aerial footage, recent developments in graph neural networks have created improvement opportunities. This paper proposes an innovative approach, the Graph Attention Convolutional U-NET (GAC-UNET) model, based on graph neural networks for automated identification of flooded areas. The model incorporates a graph attention mechanism and Chebyshev layers into the U-Net architecture. Furthermore, this paper explores the applicability of transfer learning and model reprogramming to enhance the accuracy of flood area segmentation models. Empirical results demonstrate that the proposed GAC-UNET model, outperforms other approaches with 91\% mAP, 94\% dice score, and 89\% IoU, providing valuable insights for informed decision-making and better planning of future infrastructures in flood-prone areas.

Dajun Dai

Xiaoma Li, Weiqi Zhou, Z. Ouyang et al.

I.J. van der Merwe

The decline of the small town in the South African countryside has reached a critical stage. This is reflected in the shrinking White population figures and is detrimental to the internal structure and functioning of these towns as far as services, facilities, the basis of their economies and their socio-economic population composition are concerned. This situation is the cumulative result of an obsolete reason for the existence of some towns in a changed technological milieu, the migration of the population from the countryside to the cities, and the incompetent state of some towns. Although an instant solution is not available, several approaches to this complex problem are possible. Different levels of towns could be identified before taking differentiated remedial action. It is also possible to follow up the slight signs of revival in non-metropolitan areas by using extensive development aid to guide main and subsidiary towns into vital regional centres. It should, however, be taken into account that not all towns will advance this process - some will inevitably be subjected to progressive decline in order to save the region as a whole.