Decomposing and packing polygons / Dania el-Khechen.

In this thesis, we study three different problems in the field of computational geometry: the partitioning of a simple polygon into two congruent components, the partitioning of squares and rectangles into equal area components while minimizing the perimeter of the cuts, and the packing of the maximum number of squares in an orthogonal polygon. To solve the first problem, we present three polynomial time algorithms which given a simple polygon P partitions it, if possible, into two congruent and possibly nonsimple components P 1 and P 2 : an O ( n 2 log n ) time algorithm for properly congruent components and an O ( n 3 ) time algorithm for mirror congruent components. In our analysis of the second problem, we experimentally find new bounds on the optimal partitions of squares and rectangles into equal area components. The visualization of the best determined solutions allows us to conjecture some characteristics of a class of optimal solutions. Finally, for the third problem, we present three linear time algorithms for packing the maximum number of unit squares in three subclasses of orthogonal polygons: the staircase polygons, the pyramids and Manhattan skyline polygons. We also study a special case of the problem where the given orthogonal polygon has vertices with integer coordinates and the squares to pack are (2 {604} 2) squares. We model the latter problem with a binary integer program and we develop a system that produces and visualizes optimal solutions. The observation of such solutions aided us in proving some characteristics of a class of optimal solutions

Modelling disordered foams using the vertex ensemble

Imperial Users onl

LIPIcs, Volume 248, ISAAC 2022, Complete Volume

LIPIcs, Volume 248, ISAAC 2022, Complete Volum

Psychological aspects of Psoriasis

Psoriasis is a skin condition characterised by raised, red, scaling patches that cover the body to varying degrees, with a prevalence of 1-3% in Caucasian populations. There is evidence that sufferers hospitalised for treatment of then psoriasis are more depressed and more anxious than controls (e.g. Fava et al, 1980; Lyketsos et al, 1985), but conflicting evidence about whether psoriasis outpatients are also more depressed and anxious. The research presented in this thesis examined depression and anxiety in a group of psoriasis outpatients and found statistically significantly higher depression and anxiety levels than in a group of matched controls. The relationship over tune between area of coverage of psoriasis, depression and anxiety was examined in another group of psoriasis outpatients. Using multiple regression analysis, change in area of coverage between two assessments was a significant predictor of depression and anxiety at the second assessment, once levels at the first assessment had been accounted for. Self- esteem was also examined in this way and was found to be significantly related to psoriasis area of coverage, where worsening psoriasis was associated with a lowering of self-esteem. There were statistically significant differences between males and females. Pain had not previously been examined systematically in psoriasis outpatients, but was higher than pain in matched controls in the first study reported in this thesis. Consequently the quality of pain was examined further, and found not only to be significantly related to psoriasis area of coverage, but also was described in terms which suggested a distinct character to psoriasis pain. Fluctuations in sleep quality were also found to be significantly associated with psoriasis area of coverage. Visual assessment of psoriasis area of coverage was shown to be unreliable, so a computer program (SKINMAP) was developed to allow psoriasis lesions to be mapped onto a computer which then calculates area of coverage. SKINMAP estimates were shown to be statistically significantly more accurate and reliable than visual estimates. Informal conversations with psoriasis sufferers suggested that they held firm views about their condition which often did not coincide with medical views. Lay beliefs about psoriasis in a group of sufferers were therefore investigated in detail. Sufferers showed quite high levels of knowledge about the condition, but the nature of some common misconceptions was investigated through the use of semi-structured interviews, and the results highlighted the need for better patient education

Investigating the Functions of Copper Material Culture from Four Oneota Sites in the Lake Koshkonong Locality of Wisconsin

This thesis explores Oneota use of native copper in the Lake Koshkonong locality between A.D. 1100 and 1400. Over 600 pieces of Oneota copper artifacts originating from four sites were documented and analyzed in order to investigate distribution, production, utilization, and the ideological and social significance behind this raw material. The artifacts analyzed for this study were recovered from Oneota sites adjacent to Lake Koshkonong in Jefferson County, Wisconsin: Crabapple Point (47JE93), Schmeling (47JE833), Koshkonong Creek Village (47JE379), and Crescent Bay Hunt Club (47JE904). These assemblages primarily included awls, beads, pendants, and fragmented material. The data set also includes unique items, such as adzes and a copper mace. Data collected through this project supported multiple conclusions surrounding Lake Koshkonong Oneota copper use. Manufacturing marks on beads provide arguments for multiple manufacturing traditions in the area. The use-wear observed on awls both support and question previous assumptions of their use. Additionally, the distribution of these artifacts among the sites and the iconographic symbols present among the collections suggest larger ideological and social significance of copper within Oneota groups. It also appears that the Lake Koshkonong locality has a prolonged tradition of metalworking that extends from Archaic to Historic period, implying a cultural association with metal production and the physical setting of these sites. Overall, these conclusions suggest that the Oneota viewed copper as a prestige good. These valued items both established and reaffirmed social order and legitimized the ideological, economic, military, and political power of certain individuals or kin groups living along the northwest shores of Lake Koshkonong at this time

The Third NASA Goddard Conference on Mass Storage Systems and Technologies

This report contains copies of nearly all of the technical papers and viewgraphs presented at the Goddard Conference on Mass Storage Systems and Technologies held in October 1993. The conference served as an informational exchange forum for topics primarily relating to the ingestion and management of massive amounts of data and the attendant problems involved. Discussion topics include the necessary use of computers in the solution of today's infinitely complex problems, the need for greatly increased storage densities in both optical and magnetic recording media, currently popular storage media and magnetic media storage risk factors, data archiving standards including a talk on the current status of the IEEE Storage Systems Reference Model (RM). Additional topics addressed System performance, data storage system concepts, communications technologies, data distribution systems, data compression, and error detection and correction

AutoGraff: towards a computational understanding of graffiti writing and related art forms.

The aim of this thesis is to develop a system that generates letters and pictures with a style that is immediately recognizable as graffiti art or calligraphy. The proposed system can be used similarly to, and in tight integration with, conventional computer-aided geometric design tools and can be used to generate synthetic graffiti content for urban environments in games and in movies, and to guide robotic or fabrication systems that can materialise the output of the system with physical drawing media. The thesis is divided into two main parts. The first part describes a set of stroke primitives, building blocks that can be combined to generate different designs that resemble graffiti or calligraphy. These primitives mimic the process typically used to design graffiti letters and exploit well known principles of motor control to model the way in which an artist moves when incrementally tracing stylised letter forms. The second part demonstrates how these stroke primitives can be automatically recovered from input geometry defined in vector form, such as the digitised traces of writing made by a user, or the glyph outlines in a font. This procedure converts the input geometry into a seed that can be transformed into a variety of calligraphic and graffiti stylisations, which depend on parametric variations of the strokes

et cetera

Founded in 1953, Et Cetera is an annual literary magazine that publishes the creative writing and artwork of Marshall University students and affiliates. Et Cetera is free to the Marshall University community. Et Cetera welcomes submissions in literary and film criticism, poetry, short stories, drama, all types of creative non-fiction, photography, and art

Insects

In this thematic series, engineers and scientists come together to address two interesting interdisciplinary questions in functional morphology and biomechanics: How do the structure and material determine the function of insect body parts? How can insects inspire engineering innovations