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1. Use of pupil-difference moments for predicting optical performance impacts of generalized mid-spatial frequency surface errors

   https://doi.org/10.1364/OE.503735  

   DeMars, Luke_A; Suleski, Thomas_J (October 2023, Optics Express)

   In this work, we present a methodology for predicting the optical performance impacts of random and structured MSF surface errors using pupil-difference probability distribution (PDPD) moments. In addition, we show that, for random mid-spatial frequency (MSF) surface errors, performance estimates from the PDPD moments converge to performance estimates that assume random statistics. Finally, we apply these methods to several MSF surface errors with different distributions and compare estimated optical performance values to predictions based on earlier methods assuming random error distributions. 

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2. Polygons with Prescribed Angles in 2D and 3D

   https://doi.org/10.1007/978-3-030-68766-3_11  

   Efrat, Alon; Fulek, Radoslav; Kobourov, Stephen; Toth, Csaba D. (February 2021, Graph Drawing and Network Visualization)

   null (Ed.)

   We consider the construction of a polygon P with n vertices whose turning angles at the vertices are given by a sequence A=(α0,…,αn−1) , αi∈(−π,π) , for i∈{0,…,n−1} . The problem of realizing A by a polygon can be seen as that of constructing a straight-line drawing of a graph with prescribed angles at vertices, and hence, it is a special case of the well studied problem of constructing an angle graph. In 2D, we characterize sequences A for which every generic polygon P⊂R2 realizing A has at least c crossings, for every c∈N , and describe an efficient algorithm that constructs, for a given sequence A, a generic polygon P⊂R2 that realizes A with the minimum number of crossings. In 3D, we describe an efficient algorithm that tests whether a given sequence A can be realized by a (not necessarily generic) polygon P⊂R3 , and for every realizable sequence the algorithm finds a realization. 

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3. Polygons with Prescribed Angles in 2D and 3D

   Efrat, A; Fulek, R; Kobourov, S; Toth, C (October 2020, 28th International Symposium on Graph Drawing and Network Visualization (GD))

   We consider the construction of a polygon P with n vertices whose turning angles at the vertices are given by a sequence A = (α0 , . . . , αn−1 ), αi ∈ (−π,π), for i ∈ {0,...,n − 1}. The problem of realizing A by a polygon can be seen as that of constructing a straight-line drawing of a graph with prescribed angles at vertices, and hence, it is a special case of the well studied problem of constructing an angle graph. In 2D, we characterize sequences A for which every generic polygon P ⊂ R2 realizing A has at least c crossings, and describe an efficient algorithm that constructs, for a given sequence A, a generic polygon P ⊂ R2 that realizes A with the minimum number of crossings. In 3D, we describe an efficient algorithm that tests whether a given sequence A can be realized by a (not necessarily generic) polygon P ⊂ R3, and for every realizable sequence finds a realization. 

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4. Relay Pursuit for Multirobot Target Tracking on Tile Graphs

   https://doi.org/10.1109/ICRA48891.2023.10161532  

   Mandal, Shashwata; Bhattacharya, Sourabh (May 2023, International conference on robotics and automation)

   In this work, we address a visbility-based target tracking problem in a polygonal environment in which a group of mobile observers try to maintain a line-of-sight with a mobile intruder. We build a bridge between data mining and visibility-based tracking using a novel tiling scheme for the polygon. First, we propose a tracking strategy for a team of guards located on the tiles to dynamically track an intruder when complete coverage of the polygon cannot be ensured. Next, we propose a novel variant of the Voronoi Diagram to construct navigation strategies for a team of co-located guards to track an intruder from any initial position in the environment. We present empirical analysis to illustrate the efficacy of the proposed tiling scheme. Simulations and testbed demonstrations are present in a video attachment. 

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5. Edge Sampling Using Local Network Information

   Le, C. M. (May 2021, Journal of machine learning research)

   null (Ed.)

   Edge sampling is an important topic in network analysis. It provides a natural way to reduce network size while retaining desired features of the original network. Sampling methods that only use local information are common in practice as they do not require access to the entire network and can be easily parallelized. Despite promising empirical performances, most of these methods are derived from heuristic considerations and lack theoretical justification. In this paper, we study a simple and efficient edge sampling method that uses local network information. We show that when the local connectivity is sufficiently strong, the sampled network satisfies a strong spectral property. We measure the strength of local connectivity by a global parameter and relate it to more common network statistics such as the clustering coefficient and network curvature. Based on this result, we also provide sufficient conditions under which random networks and hypergraphs can be efficiently sampled. Keywords: Network analysis, edge sampling, local information, network curvature, clustering coefficient 

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