20,343 research outputs found
Will the US Economy Recover in 2010? A Minimal Spanning Tree Study
We calculated the cross correlations between the half-hourly times series of
the ten Dow Jones US economic sectors over the period February 2000 to August
2008, the two-year intervals 2002--2003, 2004--2005, 2008--2009, and also over
11 segments within the present financial crisis, to construct minimal spanning
trees (MSTs) of the US economy at the sector level. In all MSTs, a core-fringe
structure is found, with consumer goods, consumer services, and the industrials
consistently making up the core, and basic materials, oil and gas, healthcare,
telecommunications, and utilities residing predominantly on the fringe. More
importantly, we find that the MSTs can be classified into two distinct,
statistically robust, topologies: (i) star-like, with the industrials at the
center, associated with low-volatility economic growth; and (ii) chain-like,
associated with high-volatility economic crisis. Finally, we present
statistical evidence, based on the emergence of a star-like MST in Sep 2009,
and the MST staying robustly star-like throughout the Greek Debt Crisis, that
the US economy is on track to a recovery.Comment: elsarticle class, includes amsmath.sty, graphicx.sty and url.sty. 68
pages, 16 figures, 8 tables. Abridged version of the manuscript presented at
the Econophysics Colloquim 2010, incorporating reviewer comment
Design and Value: Spatial Form and the Economic Failure of a Mall
Real estate analysts have not had the tools to identify the functional problems of real estate because they have not focused on configuration. Space syntax is a way to represent, describe and evaluate spatial configurations or patterns created through building and urban design. Space syntax was used to systematically describe the configuration of a failed luxury shopping mall. Shape recognition techniques transform the plan into a mathematical network that can be analyzed. Network node parameters can be related to more traditional measures like occupancy and revenues by location. Thus revealed, the underlying spatial structure of the failed mall is compared to that of a similar but successful mall and its functional deficiencies identified.
Dynamics of urban sprawl
This paper introduces a framework for understanding the dynamics of urban growth,particularly the continuing problem of urban sprawl. The models we present are based on transitions from vacant land to established development. We propose that the essential mechanism of transition is analogous to the way an epidemic is generated within a susceptible population, with waves of development being generated from the conversion of available land to new development and redevelopment through the aging process. We first outline the standard aggregate model in differential equation form, showing how different variants (including logistic, exponential, predator-prey models) can be derived for various urban growth situations. We then generalize the model to a spatial system and show how sprawl can be conceived as a process of both interaction/reaction and diffusion. We operationalize the model as a cellular automata (CA) which implies that diffusion is entirely local, and we then illustrate how waves of development and redevelopment characterizing both sprawl and aging of the existing urban stock, can be simulated.Finally we show how the model can be adapted to a real urban situation - the AnnArbor area in Eastern Michigan - where we demonstrate how waves of development are absorbed and modified by particular historical contingencies associated with the re-existing urban structure
Causes of sprawl: A portrait from space
We study the extent to which US urban development is sprawling and consider what determines differences in sprawl across space. Using remote-sensing data to track the evolution of land use on a grid of 8.7 billion 30x30 metre cells, we measure sprawl as the amount of undeveloped land surrounding an average urban dwelling. On this measure, while the extent of sprawl remained roughly unchanged between 1976 and 1992, it varied dramatically across metropolitan areas. Ground water availability, temperate climate, rugged terrain, decentralized employment, early public transport infrastructure, uncertainty about metropolitan growth, and unincorporated land in the urban fringe all increase sprawl.urban sprawl; land development; remote sensing
Defining contextual advantage: exploring the contextual relation between effectuation and entrepreneurial marketing for creating new markets effectually
The paper explores the behaviour of the Entrepreneur and the Effectual use of available resources mainly social capital in new market creation. The study dwells on creating a unique âContextâ by leveraging these resources to increase the Entrepreneurial orientation of a firm. The paper further attempts to explore whether the Contextual link between Effectuation and Entrepreneurial Marketing helps develop a âContextual Advantageâ, which can be used as a mean of developing a unique business model which differentiates the firm in the market. The paper hence explores contemporary theories of Entrepreneurship and Marketing
namely Entrepreneurial Marketing, Effectuation and Contextual Marketing by studying their inter-relation. The nature of these theories is under-explored according to the authors and requires further investigation to evolve the field of Marketing and Entrepreneurship.N/
The Pioneer maser signal anomaly: Possible confirmation of spontaneous photon blueshifting
The novel physics methodology of subquantum kinetics predicted in 1980 that
photons should blueshift their frequency at a rate that varies directly with
negative gravitational potential, the rate of blueshifting for photons
traveling between Earth and Jupiter having been estimated to average
approximately (1.3 +/- 0.65) X 10^-18 s^-1, or (1.1 +/- 0.6) X 10^-18 s^-1 for
signals traveling a roundtrip distance of 65 AU through the outer solar system.
A proposal was made in 1980 to test this blueshifting effect by transponding a
maser signal over a 10 AU round-trip distance between two spacecraft. This
blueshift prediction has more recently been corroborated by observations of
maser signals transponded to the Pioneer 10 spacecraft. These measurements
indicate a frequency shifting of approximately (2.28 +/- 0.4) X 10^-18 s^-1
which lies within 2 sigma of the subquantum kinetics prediction and which
cannot be accounted for in terms of known forces acting on the craft. This
blueshifting phenomenon implies the existence of a new source of energy which
is able to account for the luminosities of red dwarf and brown dwarf stars and
planets, and their observed sharing of a common mass-luminosity relation.Comment: 20 pages, 3 figures, 2 table
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