Wichita State University

About: Wichita State University is a education organization based out in Wichita, Kansas, United States. It is known for research contribution in the topics: Population & Poison control. The organization has 4988 authors who have published 9563 publications receiving 253824 citations. The organization is also known as: WSU & Fairmount College.

Spatio-Temporal Covariance Functions Generated by Mixtures

Abstract: Spatio-temporal covariance functions are introduced in this paper by using two approaches: (1) positive power mixture of purely spatial and purely temporal covariances, and (2) scale mixture of purely spatial and purely temporal covariances. Various parametric and nonparametric families of nonseparable spatio-temporal covariance functions are obtained with appropriate selections of the mixing function and covariances being mixed.

Solving geometric constraint systems. II. A symbolic approach and decision of Rc-constructibility

Abstract: This paper reports a geometric constraint-solving approach based on symbolic computation. With this approach, we can compute robust numerical solutions for a set of equations and give complete methods of deciding whether the constraints are independent and whether a constraint system is over-constraint. Based on symbolic computation, we also have a decision procedure for the problem of deciding whether a constrained diagram can be constructed with ruler and compass (rc-constructibility).

Equity market timing and capital structure: International evidence

Abstract: We investigate the equity market timing hypothesis of capital structure in major industrialized (G-7) countries. As claimed by its proponents, we find that leverage of firms is negatively related to the historical market-to-book ratio in all G-7 countries. However, this negative relationship cannot be attributed to equity market timing. We find no association between equity issues and market-to-book ratios at the time of equity financing decisions by Japanese firms. Firms in all G-7 countries, except Japan, undo the effect of equity issuance and the impact of equity market timing attempts on leverage is short lived. This is inconsistent with the prediction of the equity market timing hypothesis and more in line with dynamic trade-off model.