2,394 research outputs found

    Hypotheses in Marketing Science: Literature Review and Publication Audit

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    We examined three approaches to research in marketing: exploratory hypotheses, dominant hypothesis, and competing hypotheses. Our review of empirical studies on scientific methodology suggests that the use of a single dominant hypothesis lacks objectivity relative to the use of exploratory and competing hypotheses approaches. We then conducted a publication audit of over 1,700 empirical papers in six leading marketing journals during 1984-1999. Of these, 74% used the dominant hypothesis approach, while 13 % used multiple competing hypotheses, and 13% were exploratory. Competing hypotheses were more commonly used for studying methods (25%) than models (17%) and phenomena (7%). Changes in the approach to hypotheses since 1984 have been modest; there was a slight decrease in the percentage of competing hypotheses to 11%, which is plained primarily by an increasing proportion of papers on phenomena. Of the studies based on hypothesis testing, only 11 % described the conditions under which the hypotheses would apply, and dominant hypotheses were below competing hypotheses in this regard. Marketing scientists differed substantially in their opinions about what types of studies should be published and what was published. On average, they did not think dominant hypotheses should be used as often as they were, and they underestimated their use

    "Valuing the Visual Disamenity of Offshore Wind Projects at Varying Distances from the Shore: An Application on the Delaware Shoreline"

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    Several offshore wind power projects are under consideration in the United States. A concern with any wind power project is the visual disamenity it may create. Using a stated preference choice model, we estimated the external costs to residents of the State of Delaware for offshore wind turbines located at different distances from the coast. The annual costs to inland residents was 19,19, 9, 1,and1, and 0 (2006)forturbineslocatedat1,3.6,6,and9milesoffshore.Thecosttoresidentslivingontheoceanwas) for turbines located at 1, 3.6, 6, and 9 miles offshore. The cost to residents living on the ocean was 80, 69,69, 35, and $27 for the same increments.Windfarms, View Disamenity, Valuation

    Hypotheses in Marketing Science: Literature Review and Publication Audit

    Get PDF
    We examined three approaches to research in marketing: exploratory hypotheses, dominant hypothesis, and competing hypotheses. Our review of empirical studies on scientific methodology suggests that the use of a single dominant hypothesis lacks objectivity relative to the use of exploratory and competing hypotheses approaches. We then conducted a publication audit of over 1,700 empirical papers in six leading marketing journals during 1984-1999. Of these, 74% used the dominant hypothesis approach, while 13 % used multiple competing hypotheses, and 13% were exploratory. Competing hypotheses were more commonly used for studying methods (25%) than models (17%) and phenomena (7%). Changes in the approach to hypotheses since 1984 have been modest; there was a slight decrease in the percentage of competing hypotheses to 11%, which is explained primarily by an increasing proportion of papers on phenomena. Of the studies based on hypothesis testing, only 11 % described the conditions under which the hypotheses would apply, and dominant hypotheses were below competing hypotheses in this regard. Marketing scientists differed substantially in their opinions about what types of studies should be published and what was published. On average, they did not think dominant hypotheses should be used as often as they were, and they underestimated their use.marketing, marketing research, marketing science

    SPATIAL VARIABILITY IN FOREST FUELS: SIMULATION MODELING AND EFFECTS ON FIRE BEHAVIOR

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    Forests in the western United States and elsewhere face a growing crisis arising from global warming, changes in fuel beds and an increasing human population. Fire management policy emphasizes fuel treatments, such as thinning and prescribed burning, to remedy this situation because fuels are the one component of the problem that we can directly affect through management action. At present, however, the tools we have for the evaluation of fuel treatments are inadequate because they do not describe the fuel bed, or effects of modifications to the fuel bed on fire behavior in sufficient detail. The work described here presents a system that has potential to address the shortcomings of current approaches. In the first chapter, to improve our ability to represent wildland fuels, a three dimensional spatially explicit fuel model, FUEL3D, is presented which represents fuels at a level of detail comparable to what we can actually measure: stands as collections of individual trees, with branches and foliage. In conjunction with new, physical fire models, detailed fire behavior simulations can be carried out using fuels represented with FUEL3D as inputs. This system thus comprises a simulation laboratory which will greatly enhance our capabilities to evaluate fuel treatments and strengthen our understanding of fire and fuel interactions. In the second chapter, this system is demonstrated in an exploratory simulation study which examines the impact of spatial variability within an individual tree crown on fire behavior. Results demonstrate that the distribution of fuel within a tree crown significantly affects the rate of fuel consumption, as well as the timing, duration and magnitude of heat produced. This suggests that modeling of both crown fire initiation and propagation would benefit from more detailed description of crown fuels. In third chapter a replicated series of stand scale fire simulations is carried out to examine variability in forward spread rate; accelerated spread rates endanger fire fighters. Substantial variability is observed to arise from fine scale fuel-atmosphere-fire interactions which are not easily predicted beforehand. A new strategy is proposed in which physical fire models are used to quantify the potential drivers of variability in fire behavior

    AGN observations with a less than 100 GeV threshold using H.E.S.S. II

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    The recent addition of the 28 m Cherenkov telescope (CT5) to the H.E.S.S. array extended the experiment's sensitivity towards low energies. The lowest energy threshold is obtained using monoscopic observations with CT5, providing access to gamma-ray energies below 100 GeV. This is particularly beneficial for studies of Active Galactic Nuclei (AGN) with soft spectra and located at redshifts >= 0.5. Stereoscopic measurements with the full array (CT1-5) provide a better background rejection than CT5 Mono, at a cost of a higher threshold. We report on the analysis employing the CT5 data for AGN observations with a < 100 GeV threshold. In particular, the spectra of PKS 2155-304 and PG 1553+113 are presented.Comment: In Proceedings of the 34th International Cosmic Ray Conference (ICRC2015), The Hague, The Netherland

    Optimization of Oleosin 30G Production for Echocardiography

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    Provided they are uniform in size, monodisperse microbubbles behave as contrast agents to enhance echocardiographic imaging. Compounds like Oleosin 30G with surfactant-like properties help stabilize microbubbles - thereby ensuring their uniform size. Designed herein is an industrial-scale plant to produce medical-grade Oleosin 30G with a process consisting of three steps: 1) upstream production via recombinant E. coli in an integrated batch bioprocessing model, 2) downstream purification, and 3) processing by microfluidic manifolds. Ultimately Oleosin 30G-coated microbubbles are manufactured, ready for injection within one month. Owing to its unique properties and cost-effective production, Oleosin 30G has the potential to outcompete current market leader Definity®. Altogether, overall yield of Oleosin 30G constitutes 7.39 kg/year to provide for 100% market saturation. Financial analysis indicates pursuing Oleosin 30G for echocardiography applications is very profitable with a 296% return on investment and holds potential for production expansion should the market demand increase

    A model for predicting dissolved organic carbon distribution in a reservoir water using fluorescence spectroscopy

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    A number of water treatment works (WTW) in the north of England (UK) have experienced problems in reducing the dissolved organic carbon (DOC) present in the water to a sufficiently low level. The problems are experienced in autumn/ winter when the colour increases and the coagulant dose at the WTW needs to be increased in order to achieve sufficient colour removal. However, the DOC content of the water varies little throughout the year. To investigate this further, the water was fractionated using resin adsorption techniques into its hydrophobic (fulvic and humic acid fractions) and hydrophilic (acid and non-acid fractions) components. The fractionation process yields useful information on the changing concentration of each fraction but is time consuming and labour intensive. Here, a method of rapidly determining fraction concentration was developed using fluorescence spectroscopy. The model created used synchronous spectra of fractionated material compared against bulk water spectra and predicted the fraction concentrations to within 10% for a specific water. The model was unable to predict fraction concentrations for waters from a different watershed

    The influence of flow discharge variations on the morphodynamics of a diffluence-confluence unit on a large river: Impacts of discharge variation on a diffluence-confluence unit

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    © 2017 The Authors. Earth Surface Processes and Landforms published by John Wiley & Sons Ltd. Bifurcations are key geomorphological nodes in anabranching and braided fluvial channels, controlling local bed morphology, the routing of sediment and water, and ultimately defining the stability of their associated diffluence–confluence unit. Recently, numerical modelling of bifurcations has focused on the relationship between flow conditions and the partitioning of sediment between the bifurcate channels. Herein, we report on field observations spanning September 2013 to July 2014 of the three-dimensional flow structure, bed morphological change and partitioning of both flow discharge and suspended sediment through a large diffluence–confluence unit on the Mekong River, Cambodia, across a range of flow stages (from 13 500 to 27 000 m 3 s −1 ). Analysis of discharge and sediment load throughout the diffluence–confluence unit reveals that during the highest flows (Q = 27 000 m 3 s −1 ), the downstream island complex is a net sink of sediment (losing 2600 ± 2000 kg s −1 between the diffluence and confluence), whereas during the rising limb (Q = 19 500 m 3 s −1 ) and falling limb flows (Q = 13 500 m 3 s −1 ) the sediment balance is in quasi-equilibrium. We show that the discharge asymmetry of the bifurcation varies with discharge and highlight that the influence of upstream curvature-induced water surface slope and bed morphological change may be first-order controls on bifurcation configuration. Comparison of our field data to existing bifurcation stability diagrams reveals that during lower (rising and falling limb) flow the bifurcation may be classified as unstable, yet transitions to a stable condition at high flows. However, over the long term (1959–2013) aerial imagery reveals the diffluence–confluence unit to be fairly stable. We propose, therefore, that the long-term stability of the bifurcation, as well as the larger channel planform and morphology of the diffluence–confluence unit, may be controlled by the dominant sediment transport regime of the system. © 2017 The Authors. Earth Surface Processes and Landforms published by John Wiley & Sons Ltd
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