9,341 research outputs found
Value innovation modelling: Design thinking as a tool for business analysis and strategy
This paper explores the use of multiple perspective problem framing (English 2008) as a tool to reveal hidden value and commercial opportunity for business.
Creative thinking involves the interrelationship of parameters held open and fluid within the cognitive span of the creative mind. The recognition of new associations can create new value that can lead to innovation in designed products, intellectual property and business strategy.
The ‘Ideas-lab’ process is based on the proposition that a company’s capacity for innovation is dependent on the way the business is able to see its problems and opportunities. In this process the attributes of a company and the experience of the researchers are considered as the parameters of a design problem. It is therefore important to acknowledge the commercial experience of the project researchers, all of whom have a proven track record in helping businesses develop, exploit and protect their know how.
Semi structured interviews were carried out with key individuals in 34 companies. The resulting data was assessed on a company-by-company basis through a process of multiple
perspective problem framing, enabling key nodes, patterns and relationships to be identified and explored. A ‘Cornerstones of Innovation’ report was prepared to inform each company of the observations made by the researchers.
The paper describes the methods adopted and summarises the feedback from participating companies. Case studies are highlighted to demonstrate ways in which the process influenced the actions of particular businesses, and the commercial outcomes that resulted. Finally the researchers reflect on the structure of the Ideas-lab process
Investigations of high altitude geomagnetic phenomena using rubidium vapour systems
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Bias and Sensitivity Analysis When Estimating Treatment Effects from the Cox Model with Omitted Covariates
Omission of relevant covariates can lead to bias when estimating treatment or exposure effects from survival data in both randomized controlled trials and observational studies. This paper presents a general approach to assessing bias when covariates are omitted from the Cox model. The proposed method is applicable to both randomized and non‐randomized studies. We distinguish between the effects of three possible sources of bias: omission of a balanced covariate, data censoring and unmeasured confounding. Asymptotic formulae for determining the bias are derived from the large sample properties of the maximum likelihood estimator. A simulation study is used to demonstrate the validity of the bias formulae and to characterize the influence of the different sources of bias. It is shown that the bias converges to fixed limits as the effect of the omitted covariate increases, irrespective of the degree of confounding. The bias formulae are used as the basis for developing a new method of sensitivity analysis to assess the impact of omitted covariates on estimates of treatment or exposure effects. In simulation studies, the proposed method gave unbiased treatment estimates and confidence intervals with good coverage when the true sensitivity parameters were known. We describe application of the method to a randomized controlled trial and a non‐randomized study
The geography of entrepreneurship in the New York metropolitan area
This article was presented at a conference organized by the Federal Reserve Bank of New York in April 2005, "Urban Dynamics in New York City." The goal of the conference was threefold: to examine the historical transformations of the engine-of-growth industries in New York and distill the main determinants of the city's historical dominance as well as the challenges to its continued success; to study the nature and evolution of immigration flows into New York; and to analyze recent trends in a range of socioeconomic outcomes, both for the general population and recent immigrants more specifically.Business enterprises - New York (N.Y.) ; Economic conditions - New York (N.Y.) ; Federal Reserve District, 2nd ; Urban economics
Pathways to Economic Mobility: Key Indicators
Outlines how indicators of social, human, and financial capital affect an individual's chances of moving up or down the economic ladder. Analyzes data on family structure, community, education, race/ethnicity, health, home ownership, and other factors
Chemical and forensic analysis of JFK assassination bullet lots: Is a second shooter possible?
The assassination of President John Fitzgerald Kennedy (JFK) traumatized the
nation. In this paper we show that evidence used to rule out a second assassin
is fundamentally flawed. This paper discusses new compositional analyses of
bullets reportedly to have been derived from the same batch as those used in
the assassination. The new analyses show that the bullet fragments involved in
the assassination are not nearly as rare as previously reported. In particular,
the new test results are compared to key bullet composition testimony presented
before the House Select Committee on Assassinations (HSCA). Matches of bullets
within the same box of bullets are shown to be much more likely than indicated
in the House Select Committee on Assassinations' testimony. Additionally, we
show that one of the ten test bullets is considered a match to one or more
assassination fragments. This finding means that the bullet fragments from the
assassination that match could have come from three or more separate bullets.
Finally, this paper presents a case for reanalyzing the assassination bullet
fragments and conducting the necessary supporting scientific studies. These
analyses will shed light on whether the five bullet fragments constitute three
or more separate bullets. If the assassination fragments are derived from three
or more separate bullets, then a second assassin is likely, as the additional
bullet would not easily be attributable to the main suspect, Mr. Oswald, under
widely accepted shooting scenarios [see Posner (1993), Case Closed, Bantam, New
York].Comment: Published in at http://dx.doi.org/10.1214/07-AOAS119 the Annals of
Applied Statistics (http://www.imstat.org/aoas/) by the Institute of
Mathematical Statistics (http://www.imstat.org
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Environmental regulation of the growth, physiology and virulence of <i>Legionella pneumophila</i>
Members of the Legionellaceae cause respiratory infections in man; the most severe, pneumonic form is known as Legionnaires' disease. Of the 39 species described to date 16 have been associated with human disease, however the majority of reported cases of legionellosis are caused by Legionella pneumophila serogroup 1. A number of pathogenic bacteria regulate their virulence gene expression in response to environmental stimuli. Temperature and the availability of iron are considered to be stimuli which signal entry to a host environment.
The first part of this study utilised chemostat culture to investigate the influence of growth temperature and the availability of iron on the physiology, morphology and virulence of L. pneumophila serogroup 1. This study demonstrated, for the first time, that the virulence of L. pneumophila was significantly reduced (P < 0.05) when the culture temperature was lowered from 37 to 24°C and this modulation was reversed by returning the temperature to 37°C which resulted in a statistically significant (P < 0.05) increase in virulence. Further experiments demonstrated that the concentration of iron in the growth medium also had an effect on virulence. Contrary to expectations iron-limited cultures were less virulent than those grown iron-replete. This modulation was also reversible with a return to virulence when iron-replete conditions were restored.
The physiology and morphology of L. pneumophila were also influenced by both growth temperature and iron-limitation. At 24°C cultures consisted of flagellated short rods, whereas cultures grown at 37°C were pleomorphic and flagella were not evident. It was demonstrated that L. pneumophila accumulates the intracellular carbon storage compound, polyhydroxybutyrate, and that the proportion of the cell dry weight which it comprised varied with growth temperature, being maximal at 24°C. The ratio of saturated to unsaturated fatty acids in L. pneumophila decreased as the temperature was reduced to 24QC; this is a common strategy designed to maintain membrane fluidity. Siderophore production was detected in iron-limited cultures but not in iron replete cultures. Protease production was also affected by both growth temperature and iron-limitation.
The BIOLOG bacterial identification system was modified for use with legionellae and this was used to investigate the metabolic versatility of these bacteria. A database containing substrate utilisation profiles of Legionella species was constructed using the modified system; this was then used to identify legionella isolates to species level.
Evaporative cooling towers are a significant source of Legionnaires' disease accounting for the majority of outbreak cases in the United Kingdom. In the second part of this study a microbiologically-contained, fully-functional evaporative cooling tower was constructed and used to investigate factors that could influence the growth of L. pneumophila in such systems. The mode of operation of the cooling tower was found to influence the multiplication of legionellae in the system. Low-usage situations resulted in enhanced growth of L. pneumophila. Growth of L. pneumophila demonstrated a significant positive correlation with water temperature but its concentration decreased with increased conductivity. The concentrations of calcium, magnesium, potassium and zinc and the total hardness of the water all exhibited inverse relationships with legionella population size. The protocol for the emergency disinfection of cooling systems recommended in the Report of the Department of Health Expert Advisory Committee on Biocides did not eradicate L. pneumophila from the experimental cooling tower
Investigative study of the reliability of a rotating turbine blade
-Turbine blading incidents are a concern to electrical utilities since they can result in power plant unavailability. The reliability of a particular turbine blade is investigated in this report to determine if it can be replaced with a more reliable blade design. The majority of incidents concerning this blade have been attributed to stall flutter vibration that has been the result of unit operation at low load levels with high back-pressures in the steam condenser. Stall flutter can be avoided by limiting back-pressure levels during low load operation and is thus not a concern here. Another potential cause of unreliability is stress corrosion cracking of the rotor portion of the blade attachment. A life calculation is developed and predicts that stress corrosion cracking of the rotor portion of the blade attachment poses no threat to the reliability of this blade
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