Potential flow around two-dimensional airfoils using a singular integral method

The problem of potential flow around two-dimensional airfoils is solved by using a new singular integral method. The potential flow equations for incompressible potential flow are written in a singular integral equation. The equation is solved at N collocation points on the airfoil surface. A unique feature of this method is that the airfoil geometry is specified as an independent variable in the exact integral equation. Compared to other numerical methods, the present calculation procedure is much simpler and gives remarkable accuracy for many body shapes. An advantage of the present method is that it allows the inverse design calculation and the results are extremely accurate

Linear Combinations of Harmonic Univalent Mappings

Many properties are known about analytic functions, however the class of harmonic functions which are the sum of an analytic function and the conjugate of an analytic function is less understood. We wish to find conditions such that linear combinations of univalent harmonic functions are univalent. We focus on functions whose image is convex in one direction i.e. each line segment in that direction between points in the image is contained in the image. M. Dorff proved sufficient conditions such that the linear combination of univalent harmonic functions will be univalent on the unit disk. The conditions are: the mappings must be locally univalent, their images must be convex in the imaginary direction and they must satisfy a normalization which states that the right and left extremes of the image are the image of 1 and -1 respectively. In this paper we generalize this existing theorem. The conditions of this theorem are geometric, and we would like to maintain this feature in the generalization. We show that the image may be convex in any direction and that any points on the boundary of the domain, which no longer must be the unit disk, can be the points that are mapped to the extrema, which now must be in the direction perpendicular to the direction of convexity

Learning and Predicting Group Preference: Modeling Group Utility Function with Artificial Neural Networks

This paper reports on an empirical investigation into the ability of Artificial Neural Networks (ANN) in approximating group preference. Given the existence of a group utility function in a multi-criteria decision context, an ANN, as a universal function approximator, would be able to recognize group decision patterns, approximate the underlying functional relationship, and generalize over new cases. The merit of ANN over the traditional utility theory approach is in its ability to learn group preference without imposing strong assumptions on the functional form and behavior of decision patterns

On Learning and Predicting Preference with Artificial Neural Networks: Some Preliminary Results

This paper reports on an empirical investigation into the ability of Artificial Neural Network (ANN) technique in learning and predicting preference. ANNs were used to learn preference patterns of holistic judgments on a sample of multi-criteria decision alternatives defined by the orthogonal design. Then a comparative study was conducted with utility theory-based models and ANNs to predict decision makers’ choice. In all cases, the predictive ability of ANN was found to be as good as or better than those of utility theory-based models

Investigating the uses of corporate reputation and its effects on brand segmentation, brand differentiation and brand positioning: evidence from the Taiwanese pharmaceutical industry

This study advances current knowledge on building a brand strategy that includes corporate reputation. It employs three theories – value creation, strategic resources and corporate communication – to study the uses of corporate reputation and its effect on brand segmentation, brand differentiation and brand positioning. In the context of the Taiwanese pharmaceutical industry, a sequential mixed method approach is applied and data are analyzed using PLS SEM. Findings demonstrate the relative impacts of three uses of corporate reputation (value creation, strategic resources and corporate communication) on brand image strategy (brand segmentation, brand differentiation and brand positioning) and the implications are evaluated. This study discovers that the inclusion of medicine prices is necessary and that it negatively moderates the impact of the overall uses of corporate reputation on overall brand image strategy. This research contributes empirically as one of the few that tests reputation-and-branding-building models outside the USA and Europe