In this paper, we investigate some properties of a new type of 2D Hidden Markov Model, based on the notion of Dependency Tree. DT-HMMs avoid the complexity of regular 2D HMMs by changing the double horizontal and vertical spatial dependencies into a random uni-directional dependency, either horizontal or vertical. We explore various issues about the effect of this random choice. This type of pr...

Lateral inhibition at the first synapse in the retina is important for visual perception, enhancing image contrast, color discrimination, and light adaptation. Despite decades of research, the feedback signal from horizontal cells to photoreceptors that generates lateral inhibition remains uncertain. GABA, protons, or an ephaptic mechanism have all been suggested as the primary mediator of feed...

In most habitats, vegetation provides the main structure of the environment. This complexity can facilitate biodiversity and ecosystem services. Therefore, measures of vegetation structure can serve as indicators in ecosystem management. However, many structural measures are laborious and require expert knowledge. Here, we used consistent and convenient measures to assess vegetation structure o...

This paper presents a novel approach for detecting vehicles for driver assistance. Assuming flat roads, vanishing point is first estimated using Hough transform space to reduce the computational complexity. Localization of vehicles is carried using horizontal projection on the horizontal gradient image below vanishing point. An uppermost and lowermost peak in the horizontal profile corresponds ...

Phylogenetic tree reconstruction is usually done by local search heuristics that explore the space of the possible tree topologies via simple rearrangements of their structure. Tree rearrangement heuristics have been used in combination with practically all optimization criteria in use, from maximum likelihood and parsimony to distance-based principles, and in a Bayesian context. Their basic co...

One of the most concerning issues for researchers is to predict the shape and dimensions of the scour pit nearhydraulic structures such as the base of bridges, weirs, valves and stilling basins due to both financial and humanhazards induced by destruction of the structure. As the scour issue has its own complexity in relation to themultiplicity of effecting factors on it, in this study therefor...

Modern microprocessors have sacrificed the exactness of exceptions for improved performance long ago. This is a side effect of reordering instructions so that the microprocessor can execute instructions which were not to be executed due to an exception. By throwing more circuits at the problem, microprocessors are designed so that they are able to roll back to the instruction causing the except...