7,827 research outputs found
Online revenue model adoption in the media sector: in-depth results from an exploratory study in the Netherlands
Especially for companies in the media sector such as publishers, the Internet has created new strategic and commercial opportunities. However, many companies in the media sector are struggling with how to adapt their business and revenue model for doing profitable business online. This exploratory study goes into the success factors and the level of adoption of online revenue models by media sector companies. We use Chaffey (2002) in determining online revenue models in which we included Osterwalder’s (2001) four ‘pillars’ of business models. These four pillars cover the twelve critical success factors for e-businesses as identified by Sung (2004). This theoretical framework was used for in-depth interviews with 20 senior managers within the media sector in the Netherlands. From this, it appeared that advertising is the most used online revenue model, with targeting advertising, lead generation and a combination of content and customer profiles as most promising. Ease of use is distinguished by all senior managers as success factor. Still, in order to be successful, all factors should be applied, and this appears not to be the case. Organizations in the media sector need to invest in technical and organizational expertise by hiring the right employees with the right knowledge. Emphasis on target advertising and lead generation are most promising. A combination of content and customer profiles is a focus-point for the near future
Catecholaminergic neurons in the peripheral nervous system:a critical reappraisal of the sympathetic-parasympathetic paradigm for the classification of nerves, ganglia and neurons
Flexible and practical modeling of animal telemetry data: hidden Markov models and extensions
We discuss hidden Markov-type models for fitting a variety of multistate random walks to wildlife movement data. Discrete-time hidden Markov models (HMMs) achieve considerable computational gains by focusing on observations that are regularly spaced in time, and for which the measurement error is negligible. These conditions are often met, in particular for data related to terrestrial animals, so that a likelihood-based HMM approach is feasible. We describe a number of extensions of HMMs for animal movement modeling, including more flexible state transition models and individual random effects (fitted in a non-Bayesian framework). In particular we consider so-called hidden semi-Markov models, which may substantially improve the goodness of fit and provide important insights into the behavioral state switching dynamics. To showcase the expediency of these methods, we consider an application of a hierarchical hidden semi-Markov model to multiple bison movement paths
Analytical Formulation of the Jacobian Matrix for Non-linear Calculation of the Forced Response of Turbine Blade Assemblies with Wedge Friction Dampers
A fundamental issue in turbomachinery design is the dynamical stress assessment of turbine blades. In order to reduce stress peaks in the turbine blades at engine orders corresponding to blade natural frequencies, friction dampers are employed. Blade response calculation requires the solution of a set of non-linear equations originated by the introduction of friction damping. Such a set of non-linear equations is solved using the iterative numerical Newton-Raphson method. However, calculation of the Jacobian matrix of the system using classical numerical finite difference schemes makes frequency domain solver prohibitively expensive for structures with many contact points. Large computation time results from the evaluation of partial derivatives of the non-linear equations with respect to the displacements. In this work a methodology to compute efficiently the Jacobian matrix of a dynamic system having wedge dampers is presented. It is exact and completely analytical. The proposed methods have been successfully applied to a real intermediate pressure turbine (IPT) blade under cyclic symmetry boundary conditions with underplatform wedge dampers. Its implementation showed to be very effective, and allowed to achieve relevant time savings without loss of precision
Digital sum problems and substitutions on a finite alphabet
AbstractLet (ui)i ≥ 1 be a fixed point for a substitution σ on a finite alphabet A and for a ∈ A, f(a) a real number. We establish an asymptotic formula for S(N) = Σn < NΣi ≤ nf(ui) in the case where the second largest eigenvalue of the substitution matrix equals one and under some additional hypothesis. More precisely S(N) = αN logθ N + NF(N) + o(N), where the real number α depending on σ and f is explicitly determined and θ > 1 is the largest eigenvalue of the substitution matrix; F is a continuous, nowhere differentiable (if α∈0), real function such that F(θx) = F(x) for all x>0. Using the same method we prove a similar formula for Σn < N s(n), s(n) the sum of digits function with respect to the system of numeration associated with σ. These formulae generalize some recent work concerning digital sum problems
Life Trajectories of female child abuse survivors thriving in adulthood
A narrative study of thriving adult female survivors of childhood maltreatment was undertaken to discover how they had achieved success. Life trajectory patterns, turning points, and setbacks were identified. Data consisted of 81 interview transcripts derived from a series of three interviews, spaced over 6 to 12 months, with 27 survivors. The childhood abuse was intrafamilial, beginning as early as infancy and continuing, in most cases, until participants left home. The onset and pace of the healing trajectory were quite variable, including a roller-coaster pattern as well as patterns of slow, steady progress and continued struggle. Four types of redemption narratives were delineated. Survivors had not been spared depression but had made achievements in work and education and displayed remarkable generativity, parenting their own children well, and mentoring other young girls, especially victims of abuse
Evidence of Springwater Acidification in the Vosges Mountains (North-East of France): Influence of Bedrock Buffering Capacity
Investigations on springwater acidity were carried out in the Vosges mountains (north-eastern France). Acid or poorly buffered spring and streamwaters were detected in the same area. The proportion of acid springwaters (pH < 5.6) is about 20% among 220 springs. The springwater pH on granite are equally spread between 5.0 and 6.8 whereas on sandstone a majority of springs is in the range 5.6 to 6.2. As a whole, but mainly on sandstone, from the 1960's to 1990's, the shape of the pH distributions shifts toward greater acidity. In the sandstone area, trends in pH, alkalinity, total hardness (corresponding to divalent cations), sulfate and nitrate were considered over the 30 yr period (1963-1996) in relation to the bedrock chemical composition. Kendall seasonal tau coefficients indicate that decreasing trends were significant for the first three parameters. Linear regression on the smoothed mean value revealed 18 and 90% decrease for pH and alkalinity respectively, for springwaters draining poor-base cation sandstone whereas only 8 and 30% decrease respectively, was observed on clay-enriched sandstone. On silica-enriched sandstone, alkalinity began to decrease in the early 70's as well as pH. Loss of alkalinity only occurred in the early 80's for springs draining clay enriched sandstone. This can be interpreted as a titration process by acid atmospheric inputs of the buffering capacity of weathering and exchange processes in the soils and the catchment bedrock. The nitrate presents an increasing step in the early seventies but possibly as a result of change in analytical technics and/or increase in atmospheric inputs mainly resulting from increase in fertiliser inputs in agricultural areas or in car traffic. Surprisingly no change in sulfate was noticed in any groups of springs probably as a result of the adsorption/mobilisation in the soils. These long-term trends in spring waters (1963-1996) confirmed the soil and streamwater acidification trends already mentioned in this region, in relation to acid atmospheric inputs since no climate nor forestry practice changes have been detected over the period. Moreover, in spite of acid atmospheric input reductions, no recovery can presently be detected
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