There are several unsolved problems concerning the model of nearly neutral mutations. One is the interaction of subdivided population structure and weak selection that spatially fluctuates. The model of nearly neutral mutations whose selection coefficient spatially fluctuates has been studied by adopting the island model with periodic extinction-recolonization. Both the number of colonies and t...

Ribonuclic acid (RNA) enjoys increasing interest in molecular biology; despite this interest fundamental algorithms are lacking, e.g. for identifying local motifs. As proteins, RNA molecules have a distinctive structure. Therefore, in addition to sequence information, structure plays an important part in assessing the similarity of RNAs. Furthermore, common sequence-structure features in two or...

Local image structure is widely used in theories of both machine and biological vision. The form of the differential operators describing this structure for space-invariant images has been well documented. Although space-variant coordinates are universally used in mammalian visual systems, the form of the operators in the space-variant coordinate system has received little attention. In this re...

From Markov additive processes to biological sequence analysis ii Preface This thesis constitutes my Ph.D.-thesis – a part of the requirements for achieving the Ph.D. degree at the The subject of the thesis is probability and bioinformatics – as viewed from a person inclined to do mathematical research. As it turned out, the thesis is highly mathematical and the scientific contribution of the t...

Considerable progress has been made in understanding the relationship between local amino acid sequence and local protein structure. Recent highlights include numerous studies of the structures adopted by short peptides, new approaches to correlating sequence patterns with structure patterns, and folding simulations using simple potentials.

The structure multivector is a new approach for analyzing the local properties of a two-dimensional signal (e.g. images). It combines the classical concepts of the structure tensor and the analytic signal in a new way. This has been made possible by using a representation in the algebra of quaternions. The resulting method is linear and of low complexity. The filter-response includes local phas...

Relatively extremal knots are the relative minima of the ropelength functional in the C1 topology. They are the relative maxima of the thickness (normal injectivity radius) functional on the set of curves of …xed length, and they include the ideal knots. We prove that a C1;1 relatively extremal knot in Rn either has constant maximal (generalized) curvature, or its thickness is equal to half of ...

A variant of the encoder architecture, where units at the input and output layers represent nodes on a graph. is applied to the task of mapping locations to sets of neighboring locations. The degree to which the resuIting internal (i.e. hidden unit) representations reflect global properties of the environment depends upon several parameters of the learning procedure. Architectural bottlenecks. ...

An explicit formulation of Mach’s principle is given, yielding a finite gravitational background. Its value appears to be the same as the local acceleration in systems of various levels of hierarchy, which indicates that Machian forces control the formation of local structure. The large-scale chain structure can be interpreted in the same way. The level and scale at which the transition from th...