3,075 research outputs found

    An Epidemiology of Information: Data Mining the 1918 Influenza Pandemic

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    An Epidemiology of Information: Data Mining the 1918 Influenza Pandemic seeks to harness the power of data mining techniques with the interpretive analytics of the humanities and social sciences to understand how newspapers shaped public opinion and represented authoritative knowledge during this deadly pandemic. This project makes use of the more than 100 newspaper titles for 1918 available from Chronicling America at the United States Library of Congress and the Peel’s Prairie Provinces collection at the University of Alberta Library. The application of algorithmic techniques enables the domain expert to systematically explore a broad repository of data and identify qualitative features of the pandemic in the small scale as well as the genealogy of information flow in the large scale. This research can provide methods for understanding the spread of information and the flow of disease in other societies facing the threat of pandemics

    Brevity, Speed, and Deference: An Account from the Williams Chambers

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    One of the leading books on administrative law advocates judicial review for “sound governance.”Reviewing the book while sitting on the D.C. Circuit, Judge Williams posited that, even if “judges are smarter than agency heads, or have more time on their hands, or have cleverer clerks,” the proper institutional role requires more deference. Divining “sound governance” is not for courts. The Judge concluded by quoting Milton’s poem about the role of the blind: “They also serve who only stand and waite.

    Lunar mission safety and rescue Midterm presentation, Nov. 1970

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    Discussing major and minor tasks of safety and rescue planning for lunar mission

    Energy Dissipation in Interstellar Cloud Collisions

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    We present a study of the kinetic energy dissipation in interstellar cloud collisions. The main aim is to understand the dependence of the elasticity (defined as the ratio of the final to the initial kinetic energy of the clouds) on the velocity and mass ratio of the colliding clouds, magnetic field strength, and gas metallicity for head-on collisions. The problem has been studied both analytically and via numerical simulations. We have derived handy analytical relationships that well approximate the analogous numerical results. The main findings of this work are: (i) the kinetic energy dissipation in cloud collisions is minimum (i.e. the collision elasticity is maximum) for a cloud relative velocity vr30kms1v_r \simeq 30 km s^{-1}; (ii) the above minimum value is proportional ZLc2Z L_c^2, where ZZ is the metallicity and LcL_c is the cloud size: the larger is ZLc2Z L_c^2 the more dissipative (i.e. inelastic) the collision will be; (iii) in general, we find that the energy dissipation decreases when the magnetic field strength, and mass ratio of the clouds are increased and the metallicity is decreased, respectively. We briefly discuss the relevance of this study to the global structure of the interstellar medium and to galaxy formation and evolution.Comment: 16 pages, aasms LaTeX, 7 figures. ApJ, accepte

    Closed-Form Bayesian Inferences for the Logit Model via Polynomial Expansions

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    Articles in Marketing and choice literatures have demonstrated the need for incorporating person-level heterogeneity into behavioral models (e.g., logit models for multiple binary outcomes as studied here). However, the logit likelihood extended with a population distribution of heterogeneity doesn't yield closed-form inferences, and therefore numerical integration techniques are relied upon (e.g., MCMC methods). We present here an alternative, closed-form Bayesian inferences for the logit model, which we obtain by approximating the logit likelihood via a polynomial expansion, and then positing a distribution of heterogeneity from a flexible family that is now conjugate and integrable. For problems where the response coefficients are independent, choosing the Gamma distribution leads to rapidly convergent closed-form expansions; if there are correlations among the coefficients one can still obtain rapidly convergent closed-form expansions by positing a distribution of heterogeneity from a Multivariate Gamma distribution. The solution then comes from the moment generating function of the Multivariate Gamma distribution or in general from the multivariate heterogeneity distribution assumed. Closed-form Bayesian inferences, derivatives (useful for elasticity calculations), population distribution parameter estimates (useful for summarization) and starting values (useful for complicated algorithms) are hence directly available. Two simulation studies demonstrate the efficacy of our approach.Comment: 30 pages, 2 figures, corrected some typos. Appears in Quantitative Marketing and Economics vol 4 (2006), no. 2, 173--20

    The smaller the market, the better the rent capturing: electrification in North Portugal during the Interwar Period

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    This article analyses the origin of the persistently high level of electricity prices that hampered the expansion of electricity consumption during the interwar period in Porto. Initially, the rent-seeking behaviour of both the supply firm and the City Hall at the local level affected the expansion of the local electricity market. During the 1930s, this collusion at municipal level coincided with unpredictable energy policies at state level. This circumstance impeded the indispensable increase of scale and the building of a regional market of electricity in north Portugal. The literature on regulation and institutional analysis has proved very useful. Finally, though equally important, primary sources from company archives and institutional bodies were also employed.Este artículo analiza el origen de los elevados precios de la electricidad en Oporto entre las dos guerra mundiales y su secuela, su lenta electrificación. La colusión entre la compañía suministradora y el municipio limitó la expansión al comenzar el servicio hidroeléctrico; luego, la expectativa reiteradamente frustrada de una mayor intervención gubernamental fue en detrimento de mayores inversiones. Se impidió así el necesario aumento de escala, la plena integración del mercado eléctrico del Norte de Portugal y, en consecuencia, los precios eléctricos se mantuvieron elevados y la electrificación sufrió un persistente atraso. La adopción de una perspectiva institucional se ha revelado muy útil para esclarecer el funcionamiento de este mercado, que se ha examinado consultando fuentes empresariales, municipales y gubernamentales.This research has been financed by the Fundaçao Ciência e Tecnologia de Portugal

    The (d,6-Li) Reaction Studies

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    Supported by the National Science Foundation and Indiana Universit

    A panel analysis of UK industrial company failure

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    We examine the failure determinants for large quoted UK industrials using a panel data set comprising 539 firms observed over the period 1988-93. The empirical design employs data from company accounts and is based on Chamberlain’s conditional binomial logit model, which allows for unobservable, firm-specific, time-invariant factors associated with failure risk. We find a noticeable degree of heterogeneity across the sample companies. Our panel results show that, after controlling for unobservables, lower liquidity measured by the quick assets ratio, slower turnover proxied by the ratio of debtors turnover, and profitability were linked to the higher risk of insolvency in the analysis period. The findings appear to support the proposition that the current cash-flow considerations, rather than the future prospects of the firm, determined company failures over the 1990s recession

    Obesity, Metabolic Syndrome, and Adipocytes

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    Obesity and metabolic syndromes are examples whereby excess energy consumption and energy flux disruptions are causative agents of increased fatness. Because other, as yet elucidated, cellular factors may be involved and because potential treatments of these metabolic problems involve systemic agents that are not adipose depot-specific in their actions, should we be thinking of adipose depot-specific (cellular) treatments for these problems? For sure, whether treating obesity or metabolic syndrome, the characteristics of all adipose depot-specific adipocytes and stromal vascular cells should be considered. The focus of this paper is to begin to align metabolic dysfunctions with specific characteristics of adipocytes
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