We present a new algorithm for computing the straight skeleton of a polygon. For a polygon with n vertices, among which r are reflex vertices, we give a deterministic algorithm that reduces the straight skeleton computation to a motorcycle graph computation in O(n (log n) log r) time. It improves on the previously best known algorithm for this reduction, which is randomised, and runs in expected O(n √(h+1) log² n) time for a polygon with h holes. Using known motorcycle graph algorithms, our result yields improved time bounds for computing straight skeletons. In particular, we can compute the straight skeleton of a non-degenerate polygon in O(n (log n) log r + r^(4/3 + ε)) time for any ε > 0. On degenerate input, our time bound increases to O(n (log n) log r + r^(17/11 + ε))

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This research compares the leakage and rotordynamic characteristics of a slanted-tooth labyrinth seal to a conventional straight-tooth labyrinth. Detailed results comparing the rotordynamic coefficients and leakage parameters of a slanted-tooth see-through labyrinth seal and a straight-tooth see-through labyrinth seal are presented. The straight-tooth labyrinth seal used in this research was originally tested by Arthur Picardo. The slanted-tooth labyrinth seal was designed and fabricated to be identical to the straight-tooth labyrinth seal in terms of pitch, depth, and the number of teeth. The angle of inclination of the teeth in the slanted-tooth labyrinth seal was chosen to be 65° from the normal axis. The seals were tested at an inlet pressure of 70 bar-a (1015 psi-a), pressure ratios of 0.4, 0.5, and 0.6, rotor speeds of 10,200, 15,350, and 20,200 rpm, and a radial clearance of 0.2 mm (8 mils). The experiments were carried out at zero, medium, and high inlet preswirl ratios. The experimental results show only minute differences in the rotordynamic coefficients between the two seals. But, the slanted-tooth labyrinth seal leaked approximately 10% less than the straight-tooth labyrinth seal. A study of prediction versus experimental data was done. XLlaby was used for prediction. XLlaby was developed for a straight-tooth labyrinth seal design and did not do a good job in predicting the rotordynamic coefficients and the leakage rate.

Thesis (M.S.) in Communication--University of Maine, 2006. / Includes vita. Includes bibliographical references (leaves 110-112).

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This thesis analyzes three current and popular media sites, exploring a term I coin “straight benevolence.” An ostensibly supportive and progressive attitude adopted by heterosexuals and expressed toward gay men in the United States, straight benevolence surreptitiously subordinates gayness and further entrenches white masculine heterosexual privilege. In my examination of hip-hop artist Macklemore’s “Same Love,” seven Major League Baseball “It Gets Better” gay-advocacy videos, and the “Suddenly, Last Summer” episode of ABC’s primetime U.S. television series Modern Family, I take an intersectional approach to address the interanimation of sexuality, gender, and race. I ask: In what ways is gay male sexuality normalized and sanitized, which I argue are requirements for straight benevolence? What attitudes toward gayness surface? How do supposedly enlightened, even charitable, stances on gayness construct representations of ideal—straight, male, white—citizens and therefore privilege particular identities? How, in other words, does straight benevolence preserve heterosexist and racist norms?

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This thesis deals with the straight-line surfaces, their division, and properties. Because these surfaces are spatial formations, in their view it is necessary to select the appropriate type of screening. For this purpose is selected rectangular axonometric, which also deals with the work. In conclusion, the findings of these two parts are connected together and selected straight-line surfaces are shown using rectangular axonometric. Because today is more comfort use for the purposes of mathematics, especially geometry, different software, is for creating images in this thesis used programs GeoGebra and AutoCAD.

The objective of this study is to explore the methods used for automatic roof reconstruction so far and on the basis of this analysis purpose a methodology, which uses the geometric structure of Straight Skeleton for an initial approximation of the roof shape. In the first part of this thesis issues of automatic detection and extraction of building roof planes from laser scanning data are explored. Also, the Straight Skeleton is described in detail here and its potential for the construction of hip and saddle roofs is explained. An iterative approach which consists of deleting or moving appropriate points between roof planes using the principles of orthogonal regression is specified as an optimization method. In the second part of this thesis the proposed algorithm was implemented using CGAL (an open source library) and then it was tested on different data sets. In the very end, it is concluded that the use of the proposed algorithm on more complex types of roofs is inappropriate. The excellent results of the optimization of hip and saddle-shaped roof types are highlighted simultaneously.