The Negative Exponential Density Gradient and the Standard Radius: Mathematical and Empirical Relationships

1981 ◽  
Vol 13 (9) ◽  
pp. 1059-1065 ◽  
Author(s):  
D M Manson
Keyword(s):  
Density Gradient ◽  
Urban Areas ◽  
Urban Population ◽  
Empirical Relationships ◽  
Use Of Data ◽  
Exponential Density ◽  
Population Distributions ◽  
Negative Exponential ◽  
The Relationship ◽  
The Empirical Analysis

This paper demonstrates for urban areas a direct relationship between the summary measures of centrography and the slope parameter of the negative exponential density gradient model. Starting with some basic assumptions about the form of urban population distributions, a mathematical relationship between the methods is derived by applying the centrographic technique to an exponentially distributed urban population. By use of data from a diverse sample of cities that vary in population, region, area, and time of data collection, the relationship is tested empirically. The results of the empirical analysis are compared with the predictions of the derived relationship, and the causes of differences between them are discussed.

Experimental Analysis of Eleven Models of Urban Population Density

1979 ◽  
Vol 11 (6) ◽  
pp. 629-641 ◽  
Author(s):  
K Zielinski
Keyword(s):  
Population Density ◽  
Urban Population ◽  
Goodness Of Fit ◽  
City Centre ◽  
Use Of Data ◽  
Population Distributions ◽  
Gamma Distributions ◽  
Two Cities ◽  
Negative Exponential ◽  
The City

Seven models of the quadratic gamma type (negative-exponential, normal, inverse-power, quadratic negative-exponential, gamma, normal gamma, and quadratic gamma distributions) and the equilibrium models of Amson are tested by use of data from Bristol, Coventry, Derby, Leicester, Nottingham, Leeds, and Bradford. The first five of these cities are tested at two levels: By use of all radial distances and by use of only those less than four kilometres. The object of these tests was to detect differences in goodness of fit at the city centre and overall. The last two cities were used to test a model proposed to describe intercity population distributions.

Accessibility Measures and the Social Evaluation of Urban Structure

1977 ◽  
Vol 9 (9) ◽  
pp. 1013-1031 ◽  
Author(s):  
J Black ◽  
M Conroy
Keyword(s):  
Urban Areas ◽  
Travel Behaviour ◽  
Urban Structure ◽  
Travel Patterns ◽  
Social Evaluation ◽  
Use Of Data ◽  
The Social ◽  
The Relationship ◽  
Physical Accessibility ◽  
Numerical Index

The measurement of accessibility and travel patterns in urban areas is described. The methodology presented includes graphical measures of physical accessibility, a numerical index of accessibility that is consistent with graphical measures, residents' accessibility weighted by transport availability, and the relationship between accessibility and travel behaviour. Some empirical results are presented for access and travel to male and female jobs in Sydney, with the use of data collected for the 1971 Census of Population and for the Sydney Area Transportation Study. The consequences of some alternative arrangements of land use and plans to improve public transport on residents' accessibility are investigated. It is argued that accessibility measures are a useful aid to planners and policymakers in the social evaluation of urban structure.

scholarly journals Urban Population Growth and Job Opportunities: The Case of Albania

2020 ◽  
Vol 66 (4) ◽  
pp. 28-39
Author(s):  
Mario Ҫurçija ◽  
Emirjeta Bejleri
Keyword(s):  
Urban Areas ◽  
Urban Population ◽  
Complex Phenomenon ◽  
Employment Opportunities ◽  
Job Opportunities ◽  
Time Period ◽  
Urban Population Growth ◽  
The Relationship ◽  
Do So

AbstractDemographic change is a complex phenomenon, but it has generally been accepted that having better employment opportunities and quality of jobs are among important factors that determine people’s mobility. The purpose of this paper is to test the relationship between the increase in the number of people living in urban areas and the job opportunities in these areas in Albania. In order to do so, we performed a statistical analysis of a dataset on labor force surveys for the time period of 2007-2013. Our findings confirmed a positive correlation between the increase of individuals living in a certain area and job opportunities for specialized occupations in that area; however, a significant relationship was not found when job opportunities in general, in general, were considered.

scholarly journals Urban Planning and Economic Development of Nepal

2018 ◽  
Vol 32 (2) ◽  
pp. 107-118
Author(s):  
Krishna Raj Acharya
Keyword(s):  
Economic Development ◽  
Urban Planning ◽  
Urban Growth ◽  
Urban Areas ◽  
Urban Population ◽  
Economic Planning ◽  
P Value ◽  
Population Number ◽  
Independent Variables ◽  
The Relationship

Urban planning is an integral part of economic planning. The concept of planning has became more popular because of answering the questions; what to produce, how to produce and to whom should be produced. If there is a proper planning in urban areas of any country, then economic development is possible in those nations. In this paper, attempts were directed to explore the relationship between dependent and affecting variables (independent variables) in the time of study of urban planning. It concluded that there is no association among urban growth and urban population, number of urban areas as well as urban population percent. The identified urban indicators are regressed with urban growth which reveals that the variables are not best fitted so that the development of our nation is still in the verge of obstacle. P value of all these independent variables are insignificant (P > 0.05, 0.87 coefficients of urban population percent, 0.72 coefficient of number of urban areas and 0.09 coefficient of national population growth > 0.05).

Credit constraints and Rural Migration: Evidence from Six Villages in Uttar Pradesh

2018 ◽  
Vol 15 (3) ◽  
pp. 389-398
Author(s):  
Ruchi Singh
Keyword(s):  
Credit Constraints ◽  
Uttar Pradesh ◽  
Binary Logistic Regression ◽  
Binary Logistic Regression Model ◽  
Male Migration ◽  
Rural Economies ◽  
And Migration ◽  
The Relationship ◽  
The Empirical Analysis

Rural economies in developing countries are often characterized by credit constraints. Although few attempts have been made to understand the trends and patterns of male out-migration from Uttar Pradesh (UP), there is dearth of literature on the linkage between credit accessibility and male migration in rural Uttar Pradesh. The present study tries to fill this gap. The objective of this study is to assess the role of credit accessibility in determining rural male migration. A primary survey of 370 households was conducted in six villages of Jaunpur district in Uttar Pradesh. Simple statistical tools and a binary logistic regression model were used for analyzing the data. The result of the empirical analysis shows that various sources of credit and accessibility to them play a very important role in male migration in rural Uttar Pradesh. The study also found that the relationship between credit constraints and migration varies across various social groups in UP.

Capital Structure and Earnings per Share: An Empirical Analysis of Indian Corporate Sector

2015 ◽  
Vol 5 (3) ◽  
Author(s):  
Harvinder Singh Mand ◽  
Manjit Singh
Keyword(s):  
Capital Structure ◽  
Empirical Analysis ◽  
Corporate Sector ◽  
Independent Variables ◽  
Earnings Per Share ◽  
Panel Data Regression ◽  
Data Regression ◽  
The Impact ◽  
The Relationship ◽  
The Empirical Analysis

This paper intends to measure the impact of capital structure on EPS (earnings per share) in Indian corporate sector. Fifteen control variables along with capital structure have been selected to know their impact on EPS. Panel data regression has been applied to establish the relationship among dependent and independent variables. It is found from the empirical analysis that the relation of capital structure with EPS has been statistically insignificant in Indian corporate sector among all specific industries except telecommunication industry. The results are consistent with Modigliani-Miller approach.

Understanding gas bubble trauma in an era of hydropower expansion: how do fish compensate at depth?

2020 ◽  
Vol 77 (3) ◽  
pp. 556-563 ◽  
Author(s):  
Naomi K. Pleizier ◽  
Charlotte Nelson ◽  
Steven J. Cooke ◽  
Colin J. Brauner
Keyword(s):  
Bubble Growth ◽  
Gas Bubble ◽  
Hydroelectric Dams ◽  
Dissolved Gas ◽  
Empirical Relationships ◽  
Lethal Effects ◽  
Exposed Fish ◽  
Total Dissolved Gas ◽  
Rainbow Trout Oncorhynchus Mykiss ◽  
The Relationship

Hydrostatic pressure is known to protect fish from damage by total dissolved gas (TDG) supersaturation, but empirical relationships are lacking. In this study we demonstrate the relationship between depth, TDG, and gas bubble trauma (GBT). Hydroelectric dams generate TDG supersaturation that causes bubble growth in the tissues of aquatic animals, resulting in sublethal and lethal effects. We exposed fish to 100%, 115%, 120%, and 130% TDG at 16 and 63 cm of depth and recorded time to 50% loss of equilibrium and sublethal symptoms. Our linear model of the log-transformed time to 50% LOE (R2 = 0.94) was improved by including depth. Based on our model, a depth of 47 cm compensated for the effects of 4.1% (±1.3% SE) TDG supersaturation. Our experiment reveals that once the surface threshold for GBT from TDG supersaturation is known, depth protects rainbow trout (Oncorhynchus mykiss) from GBT by 9.7% TDG supersaturation per metre depth. Our results can be used to estimate the impacts of TDG on fish downstream of dams and to develop improved guidelines for TDG.

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