Fitness landscapes can be decomposed into elementary landscapes using a Fourier transform that is determined by the structure of the underlying con guration space. The amplitude spectrum obtained from the Fourier transform contains information about the ruggedness of the landscape. It can be used for classi cation and comparison purposes. We consider here three very di erent types of landscapes...

Robust control of a vision-based agent requires tight coupling between sensing and action. For mobile robots performing visually-guided navigation, this means closed-loop control of motion with respect to sensed features, landmarks, or other relevant parts of the visible environment. Real vision sensors have limited fields of view. This makes true closed-loop control with respect to an arbitrar...

It is an outstanding problem to clarify how the RNA sequence is related to its structure and biological functions. We developed a simplified definition of a metric for tree representation of RNA secondary structures and analyzed the conformational energy landscapes of human spliceosomal snRNAs. We discuss the structural properties of the biological sequence by calculating the conformational ene...

A primary focus of wildlife ecology is studying how the arrangement, quality, and distribution of habitat influence wildlife populations at multiple spatial scales. A practical limitation of conducting wildlife–habitat investigations in the field, however, is that sampling points tend to be close to one another, resulting in spatial clustering. Consequently, when ecologists seek to quantify the...

Habitat fragmentation can create significant impediments to dispersal. A technique to increase dispersal between otherwise isolated fragments is the use of corridors. Although previous studies have compared dispersal between connected fragments to dispersal between unconnected fragments, it remains unknown how dispersal between fragments connected by a corridor compares to dispersal in unfragme...

A view in object-oriented databases (OODB) corresponds to virtual schema graph with possibly restructured generalization and decomposition hierarchies. We propose a methodology, called MultiView, for supporting multiple such view schemata. MultiView represents a simple yet powerful approach achieved by breaking view speciication into independent tasks: class derivation, global schema integratio...

In all models, but especially in those used to predict uncertain processes (e.g., climate change and nonnative species establishment), it is important to identify and remove any sources of bias that may confound results. This is critical in models designed to help support decisionmaking. The geometry used to represent virtual landscapes in spatially explicit models is a potential source of bias...

The visible landscape is believed to affect human beings in many ways, including aesthetic appreciation and health and well-being. The aim of this paper is to analyse the range of landscapes used in environmental psychology studies, and the evidence of health effects related to viewing these landscapes. A literature review of publications linking landscapes and health effects was conducted. Thi...

The paper introduces the landscape assessment approach for the post-mining landscapes in the Estonian oil shale open-cast mines. Typologies of mining landscapes are based on landscape pattern, features and functions predetermined by mining technologies. The open-cast mines which have been predominantly subjected to monofunctional reforestation should direct to diversification of landscape and i...

We consider stability and robustness of feedback systems, where plant and compensator need not be strictly proper. In an earlier paper [1] we described a functional R∞ which, when negative, guarantees closed-loop instability as a result of parasitic interactions in the feedback loop. In our main result, Theorem 5, we prove that, when R∞ > 0, there exist perturbations of plant and compensator fr...