Spatial Demand Models with Uniform Rate of Growth

1975 ◽  
Vol 7 (5) ◽  
pp. 589-599 ◽  
Author(s):  
E A C Thomas ◽  
O Davies
Keyword(s):  
Economies Of Scale ◽  
Demand Function ◽  
Transportation Cost ◽  
Market Area ◽  
Constant Size ◽  
Demand Models ◽  
Market Areas ◽  
Changes Over Time ◽  
Spatial Demand ◽  
Over Time

This paper examines the changes over time in the spatial dispersion of facilities in a bounded one-dimensional habitat. Each facility produces a single good for a unique market area and demand for the good varies inversely with distance to the nearest facility and increases uniformly over time. Production and transportation cost functions are not assumed to be linear, and it is assumed that market areas are chosen so as to minimise the average cost of producing and transporting unit amount of the good. Conditions relating the demand function to the transportation cost function are given which are necessary and/or sufficient for the size of the market area to decrease over time. It is shown that if the market area has constant size, ‘balanced growth’ occurs if and only if the demand function is of the Pareto type. Finally, the relevance to this analysis of economies of scale is discussed.

Fundamental Properties of Löschian Spatial Demand

1971 ◽  
Vol 3 (3) ◽  
pp. 283-305 ◽  
Author(s):  
C A Gannon
Keyword(s):  
Demand Function ◽  
Competitive Equilibrium ◽  
Aggregate Demand ◽  
General Nature ◽  
Market Area ◽  
Fundamental Properties ◽  
First Derivative ◽  
Market Areas ◽  
Spatial Demand

Spatial demand is the aggregate demand expressed at a particular location, under given supply conditions, by a set of individual consumers whose locations are dispersed over a geographical market area. Although the concept of spatial demand has played a central role in location and spatial economics since its development by Lösch and his incorporation of it into his model of spatial competitive equilibrium, a comprehensive rigorous characterization of spatial demand does not presently exist. Accordingly, the contribution of this paper is a quite general formulation of spatial demand and a rigorous specification and evaluation of some of its most important properties. Spatial demand is found to consist of two components: free spatial demand which corresponds to a situation in which the geographic market areas of suppliers do not interact, and competitive spatial demand which corresponds to a situation in which they do. This distinction allows the derivation of conditions for, among other things, the (1) existence of these two components, (2) continuity of the spatial demand function and its first derivative, and (3) convexity or concavity of the spatial demand function. Such properties of spatial demand are basic to an evaluation of the existence, stability, and general nature of spatial competitive equilibrium.

Comparison of two devices for measuring exercise transcutaneous oxygen pressures in patients with claudication

VASA ◽  
2015 ◽  
Vol 44 (5) ◽  
pp. 355-362 ◽  
Author(s):  
Marie Urban ◽  
Alban Fouasson-Chailloux ◽  
Isabelle Signolet ◽  
Christophe Colas Ribas ◽  
Mathieu Feuilloy ◽  
...  
Keyword(s):  
Oxygen Pressure ◽  
Optical Sensors ◽  
Chemical Sensors ◽  
Transcutaneous Oxygen ◽  
Starting Values ◽  
Two Systems ◽  
Transcutaneous Oxygen Pressure ◽  
New Sensors ◽  
Changes Over Time ◽  
Over Time

Abstract. Summary: Background: We aimed at estimating the agreement between the Medicap® (photo-optical) and Radiometer® (electro-chemical) sensors during exercise transcutaneous oxygen pressure (tcpO2) tests. Our hypothesis was that although absolute starting values (tcpO2rest: mean over 2 minutes) might be different, tcpO2-changes over time and the minimal value of the decrease from rest of oxygen pressure (DROPmin) results at exercise shall be concordant between the two systems. Patients and methods: Forty seven patients with arterial claudication (65 + / - 7 years) performed a treadmill test with 5 probes each of the electro-chemical and photo-optical devices simultaneously, one of each system on the chest, on each buttock and on each calf. Results: Seventeen Medicap® probes disconnected during the tests. tcpO2rest and DROPmin values were higher with Medicap® than with Radiometer®, by 13.7 + / - 17.1 mm Hg and 3.4 + / - 11.7 mm Hg, respectively. Despite the differences in absolute starting values, changes over time were similar between the two systems. The concordance between the two systems was approximately 70 % for classification of test results from DROPmin. Conclusions: Photo-optical sensors are promising alternatives to electro-chemical sensors for exercise oximetry, provided that miniaturisation and weight reduction of the new sensors are possible.

Neuropsychological Symptoms in Posttraumatic Stress Disorder and Changes Over Time

2007 ◽  
Author(s):  
Miranda Olff ◽  
Mirjam Nijdam ◽  
Kristin Samuelson ◽  
Julia Golier ◽  
Mariel Meewisse ◽  
...  
Keyword(s):  
Posttraumatic Stress Disorder ◽  
Posttraumatic Stress ◽  
Stress Disorder ◽  
Neuropsychological Symptoms ◽  
Changes Over Time ◽  
Over Time

Changes Over Time in Adaptive Behavior Functioning of Twice-Exceptional Children

2010 ◽  
Author(s):  
Rebecca D. Stinson ◽  
Zachary Sussman ◽  
Megan Foley Nicpon ◽  
Allison L. Allmon ◽  
Courtney Cornick ◽  
...  
Keyword(s):  
Adaptive Behavior ◽  
Exceptional Children ◽  
Twice Exceptional ◽  
Changes Over Time ◽  
Over Time

Kategorisierung der Schädelform des Cavalier King Charles Spaniels

2019 ◽  
Vol 47 (02) ◽  
pp. 133-133
Keyword(s):  
Pilot Study ◽  
Cavalier King Charles Spaniel ◽  
Conformation Changes ◽  
Veterinary Record ◽  
Changes Over Time ◽  
Over Time

Knowler SP, Gillstedt L, Mitchell TJ et al. Pilot study of head conformation changes over time in the Cavalier King Charles spaniel breed. Veterinary Record 2019. doi:10.1136/vr.105135.

Uneven Decoupling

2019 ◽  
Vol 5 (4) ◽  
pp. 410-427 ◽  
Author(s):  
Ryan P. Thombs ◽  
Xiaorui Huang
Keyword(s):  
Economic Growth ◽  
Co2 Emissions ◽  
Ecological Modernization ◽  
Climate Mitigation ◽  
Data Limitations ◽  
Treadmill Of Production ◽  
Global North ◽  
Organization Of Production ◽  
Changes Over Time ◽  
Over Time

The macro-comparative decoupling literature has often sought to test the arguments made by the treadmill of production (TP) and ecological modernization (EM) theories. However, due to data limitations, these studies have been limited to analyzing the years after 1960. Given that both theories discuss historical processes operating before 1960, analyzing pre-1960 data is warranted to more comprehensively test the propositions made by both theories. We assess the long-term relationship between economic growth and CO2 emissions from 1870 to 2014 using a sample of global North nations. We use Prais-Winsten regression models with time interactions to assess whether, when, and how much CO2 emissions have decoupled from economic growth over time. We find that significant relative decoupling has occurred twice since 1870: during the last 30 years of the nineteenth century, the timing of which is contrary to what both the EM and TP theories might expect, and after 1970. We also observe that the relationship remained relatively stable from the turn of the twentieth century to approximately 1970, which aligns with the arguments made by the classical TP work. We conclude that shifts in the global organization of production have shaped the magnitude of the economic growth–CO2 emissions relationship and its changes over time, which has implications for climate mitigation policy.

Images and Reflections of the Spiritual Self in Christopher Isherwood’s Narratives

2010 ◽  
Vol 4 (3) ◽  
pp. 303-322
Author(s):  
Mario Faraone
Keyword(s):  
Conversion Period ◽  
Philosophy And Religion ◽  
Spiritual Self ◽  
Christopher Isherwood ◽  
Changes Over Time ◽  
Over Time

Throughout his life, Christopher Isherwood explored his sense of himself through a range of different genres of writing: autobiography, letters and journals, and fiction. The polysemic image of the mirror plays a major role in the structuring of his novels and other writings. Through the figure of the mirror, the writer signals many nearly imperceptible yet significant changes over time. This article explores this image in a range of Isherwood’s writings, and argues that, through its deployment, the artist very often questions himself about the dichotomy between appearance and reality. The presence of the mirror in the early writings assumes modalities which are distinct from those belonging to the conversion period to Vedanta, the Hindu-oriented philosophy and religion.

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