434 research outputs found

    Big Data, Social Physics, and Spatial Analysis: The Early Years

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    This paper examines one of the historical antecedents of Big Data, the social physics movement. Its origins are in the scientific revolution of the 17th century in Western Europe. But it is not named as such until the middle of the 19th century, and not formally institutionalized until another hundred years later when it is associated with work by George Zipf and John Stewart. Social physics is marked by the belief that large-scale statistical measurement of social variables reveals underlying relational patterns that can be explained by theories and laws found in natural science, and physics in particular. This larger epistemological position is known as monism, the idea that there is only one set of principles that applies to the explanation of both natural and social worlds. Social physics entered geography through the work of the mid-20th-century geographer William Warntz, who developed his own spatial version called ‘‘macrogeography.’’ It involved the computation of large data sets, made ever easier with the contemporaneous development of the computer, joined with the gravitational potential model. Our argument is that Warntz’s concerns with numeracy, large data sets, machine-based computing power, relatively simple mathematical formulas drawn from natural science, and an isomorphism between natural and social worlds became grounds on which Big Data later staked its claim to knowledge; it is a past that has not yet passed

    Big data, little history

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    Abstract The paper makes the argument that what is forgotten in the celebration of big data is history. Big data is presented as if it were disconnected from the past, removed from issues or problems that went before. I argue in this short commentary that the past remains potent for big data and that proponents ignore it at their peril. Rather than being a brand new approach, big data brings a series of problematic assumptions and practices first criticised 40 years ago by opponents of geography's quantitative revolution. Those assumptions, practices and criticisms are reviewed in the paper

    The Great Debate in Mid-Twentieth-Century American Geography: Fred K. Schaefer vs. Richard Hartshorne

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    The mid-twentieth-century debate around whether geography should be ideographic, and descriptively study the unique, or nomothetic, and seek law-like explanatory generalizations, was sparked in 1953 by Fred K. Schaefer. Schaefer was a political refugee from Nazi Germany and not trained as a geographer. Nonetheless, he was a professor in the Geography Department at the University of Iowa, when he penned the paper that attacked America‘s most famous and powerful geographer, Richard Hartshorne. Hartshorne‘s celebrated book, The Nature of Geography (1939) defined, justified and genealogically fixed geography as an ideographic science, that is, “concerned with the description and interpretation of unique cases. 
" (Hartshorne 1939, 449). Schaefer‘s paper excoriated all of Hartshorne‘s claims, both historical and philosophical. His alternative was the philosophy of logical positivism originating in Austria during the 1920s with a group of philosophers, scientists and mathematicians collectively known as the Vienna Circle. Logical positivism said that for any knowledge to be taken seriously as knowledge it must be expressible as a law-like generalization. When Hartshorne read Schaefer‘s critique, he was apoplectic. He wrote two virulent replies denying all of Schaefer‘s charges. Schaefer, though, was already dead so couldn‘t reply. But others did. Over the next decade some form of logical positivism took hold in the discipline and geography was never the same again

    Hierarchical decomposition and simulation of manufacturing cells using Ada

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    A useful tool in the development of flexible automation is a system description language which can generate a complete func tional description of a manufacturing cell of arbitrary complexity. We propose a description system based on the concept of hierar chical decomposition utilizing the Ada programming language in conjunction with established diagrammatical decomposition methods. The distinguishing aspect of our work is that it takes advantage of certain features of Ada (such as type checking) to create a description that can be automatically verified for con sistency Simulation is often an indispensable tool in the develop ment of manufacturing systems. We show how a simulation of the operation of the manufacturing cell can be embedded in its description. Finally, we apply the methodology to a specific instance of a manufacturing cell.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/68498/2/10.1177_003754978604600402.pd

    Parent perspectives on the benefits and risks of child-livestock interactions

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    Growing up on a farm or ranch often involves interactions with livestock that present both potential risks and benefits to children. While these “child-livestock interactions” contribute to the burden of agriculturally related injuries to youth in the United States, they may also result in improved immunological health and other benefits. Agricultural upbringings are also widely perceived to improve physical, cognitive, and skill development of children, contributing to a combination of potential benefits and risks known as the “farm kid paradox.” Although previous studies show the health impacts of child-livestock interactions, less is known about the ways in which farm and ranch parents perceive the benefits and risks of these interactions, and how and why they choose to raise children around livestock. Our research addresses this gap by analyzing data from semi-structured interviews with 30 parents of children between the ages of 10–18 who produce beef cattle in Kansas. This research is part of a larger anthropological study of the benefits and risks of child-livestock interactions involving parents on beef and dairy operations in multiple states, along with agricultural safety and health professionals. The results offer insights into the experiences, practices, and perspectives of parents, outlining agricultural ways of life in which safety and relations to risk are shaped by patterns of production, family dynamics, values and habits, and other social and cultural dimensions. These insights deepen our understanding of parents' perceptions of both benefits and risks of agricultural childhoods

    The journey effect: how travel affects the experiences of mental health in-patient service-users and their families

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    The qualitative study presented in this paper explored the perspectives of service-users, family members and staff about the impact of travel issues on the lives of mental health in-patients and carers. This topic was chosen because it was prioritised by members of Xplore, a service-user and carer research group, and has received little research attention. Travel problems were a significant issue for many service-users and carers, bound-up with mental health issues and the recovery experience. Travel facilitation through the funding of taxis and the provision of guides was appreciated. A few service-users and carers positively valued distancing from their previous home environment. The meaning of travel issues could only be understood in the context of individuals’ wider lives and relationships. The significance of the findings is discussed in relation to the social model of disability

    The mass assembly of galaxy groups and the evolution of the magnitude gap

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    We investigate the assembly of groups and clusters of galaxies using the Millennium dark matter simulation and the associated gas simulations and semi-analytic catalogues of galaxies. In particular, in order to find an observable quantity that could be used to identify early-formed groups, we study the development of the difference in magnitude between their brightest galaxies to assess the use of magnitude gaps as possible indicators. We select galaxy groups and clusters at redshift z=1 with dark matter halo mass M(R200) > 1E13/h Msun, and trace their properties until the present time (z=0). We consider only the systems with X-ray luminosity L_X> 0.25E42/h^2 erg/s at z=0. While it is true that a large magnitude gap between the two brightest galaxies of a particular group often indicates that a large fraction of its mass was assembled at an early epoch, it is not a necessary condition. More than 90% of fossil groups defined on the basis of their magnitude gaps (at any epoch between 0<z<1) cease to be fossils within 4 Gyr, mostly because other massive galaxies are assembled within their cores, even though most of the mass in their haloes might have been assembled at early times. We show that, compared to the conventional definition of fossil galaxy groups based on the magnitude gap Delta m(12)> 2 (in the R-band, within 0.5R200 of the centre of the group), an alternative criterion Delta m(14)>2.5 (within the same radius) finds 50% more early-formed systems, and those that on average retain their fossil phase longer. However, the conventional criterion performs marginally better at finding early-formed groups at the high-mass end of groups. Nevertheless, both criteria fail to identify a majority of the early-formed systems.Comment: 16 pages, 11 figures, 2 tables. Accepted for publication in MNRA

    The dark haloes of early-type galaxies in low-density environments: XMM-Newton and Chandra observations of NGC 57, NGC 7796 and IC 1531

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    We present analysis of Chandra and XMM-Newton observations of three early-type galaxies, NGC 57, NGC 7796 and IC 1531. All three are found in very low density environments, and appear to have no neighbours of comparable size. NGC 57 has a halo of kT~0.9 keV, solar metallicity gas, while NGC 7796 and IC 1531 both have ~0.55 keV, 0.5-0.6 Zsol haloes. IC 1531 has a relatively compact halo, and we consider it likely that gas has been removed from the system by the effects of AGN heating. For NGC 57 and NGC 7796 we estimate mass, entropy and cooling time profiles and find that NGC 57 has a fairly massive dark halo with a mass-to-light ratio of 44.7 (4.0,-8.5) Msol/Lsol (1 sigma uncertainties) at 4.75 Re. This is very similar to the mass-to-light ratio found for NGC 4555 and confirms that isolated ellipticals can possess sizable dark matter haloes. We find a significantly lower mass-to-light ratio for NGC 7796, 10.6 (+2.5,-2.3) Msol/Lsol at 5 Re, and discuss the possibility that NGC 7796 hosts a galactic wind, causing us to underestimate its mass.Comment: 14 pages, 9 figures, accepted for publication in MNRA
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