In this paper we study the problem of a robot searching for a visually recognizable target in an unknown simple polygon. We present two algorithms. Both work for arbitrarily oriented polygons. The search cost is proportional to the distance traveled by the robot. We use competitive analysis to judge the performance of our strategies. The rst one is a simple modiication of Djikstra's shortest pa...

in this paper, optimal distributed control of the time-dependent navier-stokes equations is considered. the control problem involves the minimization of a measure of the distance between the velocity field and a given target velocity field. a mixed numerical method involving a quasi-newton algorithm, a novel calculation of the gradients and an inhomogeneous navier-stokes solver, to find the opt...

The detection probability of visible light reconnaissance equipment is one of key indexes to assess the performance of the system. The detection probability is determined by many factors, such as atmospheric visibility, target-background contrast, target size and distance, solar elevation angle etc. Based on the detection probability model of the visible light reconnaissance equipment to gain t...

Previous studies have reported that when subjects are presented with two forms in a same-different task, their reaction times increase with the size ratio. This suggests a "mental scaling" transformation analogous to the "mental rotation" used to compensate for differently oriented forms in similar tasks. However, since the stimuli were presented in isolation, retinal and environmental size rat...

In this work, we report measurements of the height profile of transverse dunes in the coastal dune field known as “Lençóis Maranhenses”, northeastern Brazil. Our measurements show that transverse dunes with approximately the same height present a variable brink position relative to the crest, in contrast to the case of barchan dunes. Based on our field data, we present a relation for the dune s...

Using a probabilistic model, exact and approximate probability density functions (PDFs) for city-block distances and distance ratios are developed. The model assumes that stimuli can be represented by random vectors having multivariate normal distributions. Comparisons with the more common Euclidean PDFs are presented. The potential ability of the proposed model to correctly detect Euclidean an...

Basic models of Data Envelopment Analysis are intrinsically preference-free, in the sense that they consider all inputs and outputs and also all decision making units of the same importance. Although this property is beneficial in many ways, it has some drawbacks simultaneously, as the decision makers’ preferences are not taken into account in the process of evaluating units.  To overcome this ...

It is pointed out that the Diósi-Penrose ansatz for gravity-induced quantum state reduction can be tested by observing oscillations in the flavor ratios of neutrinos originating at cosmological distances. Since such a test would be almost free of environmental decoherence, testing the ansatz by means of a next generation neutrino detector such as IceCube would be much cleaner than by experiment...

A high-order accurate shock- and interface-capturing scheme is used to simulate the collapse of a gas bubble in water. In order to better understand the damage caused by collapsing bubbles, the dynamics of the shock-induced and Rayleigh collapse of a bubble near a planar rigid surface and in a free field are analysed. Collapse times, bubble displacements, interfacial velocities and surface pres...