We present hydrographic and optical data collected concurrently from two different platforms, the R/P FLoating Instrument Platform and the R/V Kilo Moana, located about 2km apart in the Santa Barbara Channel in California. We show that optical variability between the two platforms was due primarily to platform effects, specifically the breakdown of stratification from mixing by the hull of R/P ...

In this paper, the complexity of minimum corridor guarding problems is discussed. These problem can be described as: given a connected orthogonal arrangement of vertical and horizontal line segments and a guard with unlimited visibility along a line segment, find a tree or a closed tour with minimum total length along edges of the arrangement, such that if the guard runs on the tree or on the c...

Let P be a finite set of points in the plane and S a set of non-crossing line segments with endpoints in P . The visibility graph of P with respect to S, denoted Vis(P, S), has vertex set P and an edge for each pair of vertices u, v in P for which no line segment of S properly intersects uv. We show that the constrained half-θ6-graph (which is identical to the constrained Delaunay graph whose e...

Everett et al. [EHN96, EHN97] introduced several varieties of stabbing information for the lines determined by pairs of vertices of a simple polygon P , and established their relationships to vertex visibility and other combinatorial data. In the same spirit, we define the “zero-parity (ZP) stabbing information” to be a natural weakening of their “weak stabbing information,” retaining only the ...

Scanning transmission electron microscopy (STEM) images often show intensity noise due to emission fluctuation. This type of image noise often happens with field emission guns (FEG) and we may call it FEG noises. The FEG noise can become readily noticeable for a certain high intensity STEM images and usually deteriorate image quality. Fig. 1A shows an annular dark field (ADF) STEM image, where ...

In a 2-visibility drawing the vertices of a given graph are represented by rectangular boxes and the adjacency relations are expressed by horizontal and vertical lines drawn between the boxes. In this paper we want to emphasize this model as a practical alternative to other representations of graphs, and to demonstrate the quality of the produced drawings. We give several approaches, heuristics...

A visibility relation can be viewed as a graph: the uncountable graph of a visibility relationship between points in a polygon P is called the point visibility graph (PVG) of P. In this paper we explore the use of perfect graphs to characterize tractable subprob-lems of visibility problems. Our main result is a characterization of which polygons are guaranteed to have weakly triangulated PVGs, ...

We examine the connectivity fluctuations across networks obtained when the horizontal visibility (HV) algorithm is used on trajectories generated by nonlinear circle maps at the quasiperiodic transition to chaos. The resultant HV graph is highly anomalous as the degrees fluctuate at all scales with amplitude that increases with the size of the network. We determine families of Pesin-like identi...

Surface solar radiation has undergone decadal variations since the middle of the twentieth century, producing global ‘dimming’ and ‘brightening’ effects1,2. These variations presumably result from changes in aerosol burden and clouds3, but the detailed processes involved have yet to be determined. Over Europe, the marked solar radiation increase since the 1980s is thought to have contributed to...

results there was no significant differences between if and conventional mode regarding visibility of mic (p > 0.05). conclusion although using if caused improved visibility of mic, the difference with conventional mode was not statistically different. patients and methods in this cross-sectional study, 2580 digital panoramic images of 18 to 70-year-old patients were inspected for presence of m...