A current trend in residential construction is the use of prefabricated wall panels. It is important to carefully establish how panels will be stacked, because an optimal sequence will improve productivity and reduce the possibility of worker injury. Mathematical models and heuristics are proposed for solving the panel stacking problem without consideration of interference. Dissertation work includes a mathematical model of the corresponding panel stacking problems in which the goal is to minimize total weighted panel move distance concurrent with certain construction assumptions. The heuristic method was provided to establish how each panel would be stacked and gave the drop-off location of each stack. The heuristic method was found to be able to reduce the total weighted panel move distance and ensure connectivity was always maintained, meanwhile, interference could also be avoided. In terms of solution speed, the heuristic method can solve real size problems in less than one second. Solutions to such problems can increase productivity. Three improvements to the only known existing panel stacking algorithm with consideration of interference were proposed. The computational results indicate the proposed algorithm performed better than existing algorithm in all experimental cases. Improvement on panel move distance ranged from 1.35-47.93%, and improvement on interfering panels ranged from 20-100%. The proposed algorithm can solve non-rectangular cases (not possible with existing algorithm) and was compared with an experienced panel designer and commercial software. When compared to the proposed algorithm, total weighted panel move distance increased 0.10-85.52% and 0.77-136.23%, respectively, for the panel designer and software. While connectivity was 100% for all cases with the proposed algorithm (the algorithm ensures connectivity is always maintained), it ranged from 69.56-86.95% and 73.33-90.91%, however, for the panel designer and software respectively. Finally, the proposed algorithm can solve the interfering panels in the last stack: this cannot be done with the existing algorithm. Because prefabricated wall panels are typically large and cumbersome to work with, there is a significant probability of worker injury. It is important to carefully establish how each panel will be handled by workers. This is typically the responsibility of field construction foreman, but such personnel are often ill-equipped to make such decisions. An alternative, proactive approach is to establish how each panel will be handled in advance, such that overall ergonomic consequences can be properly considered. This dissertation presents mathematical models of the corresponding construction task scheduling and worker assignment problems, where the goal is to minimize total project completion time (subject to worker quantity constraints) and assign tasks to workers as evenly as possible. The solution of such problems can help residential construction managers better plan construction by establishing the ergonomic impact associated with a given construction plan. A heuristic was also developed to solve large problems by balancing workload between workers. The heuristic was found to be able to provide near-optimal solutions, and can solve large problems in less than one second. / Ph. D.

In this study earthquake data is analyzed using a newly developed Migration Based Detection (MBD) algorithm (Wagner et al. 2017). A software environment suitable for manual analysis of large quantities of earthquakes (events) detected by the MBD algorithm is set up, and the MBD algorithm is applied to 13 days of seismic data from a network of 26 seismic stations in the geologically complex Hengill-area in southwest Iceland. A total of 859 event detections are produced and manually inspected. Out of these, 483 are considered true and/or uncertain, making the assessed number of false detections about 44%. A subset of 53 well defined true events are selected for event relocation using manual picking of first arrival P-waves. The relocation resulted in a mean difference of roughly 0.6 km for each coordinate in the horizontal plane and about 1.4 km in depth. Results of the study provide reference data that may aid further development of the MBD algorithm, as well as provide some insight into the performance of the MBD algorithm. The software environment tailored for analyzing events detected by the MBD algorithm may be used as a foundation for continued analysis of detected events. / I denna studie analyserades jordskalvsdata med hjälp av en nyligen utvecklad 'migration based detection'-algoritm (Wagner et al. 2017). En mjukvarumiljö skräddarsydd för manuell analys av stora kvantiteter av jordskalv detekterade av MBD-algoritmen iordningställdes, varpå MBD-algoritmen sedan applicerades på 13 dagar av seismisk data från ett nätverk av 26 seismiska stationer i det geologiskt sett komplexa Hengill-området i sydvästra Island. Totalt detekterades 859 jordskalv som genomgick manuell analys. Av dessa klassificerades 483 stycken som bekräftade eller troliga jordskalv, vilket resulterar i en uppskattad felmarginal om ca. 44 %. En delmängd om 53 väldefinierade jordskalv valdes ut för noggrannare analys av ursprungsplats och tidpunkt genom manuell plockning av P-fasankomst. Omlokaliseringen resulterade i en genomsnittlig differens om ca. 0.6 km i vardera koordinat i horisontalplanet och ca. 1.4 km i höjdled. Resultat från projektet kan användas som referensdata vid vidareutveckling av MBD-algoritmen samt ger viss insyn i prestandan hos MBD-algoritmen. Den iordningställda datormiljön kan användas som bas för vidare analys av jordskalv detekterade av MBD-algoritmen.

Focal stacking is a technique that allows us to create images with a large depth of field, where everything in the scene is sharp and clear. However, creating such images is not easy, as it requires taking multiple pictures at different focus settings and then blending them together. In this paper, we present a novel approach to blending a focal stack using a special type of autoencoder, which is a neural network that can learn to compress and reconstruct data. Our autoencoder consists of several parts, each of which processes one input image and passes its information to the final part, which fuses them into one output image. Unlike other methods, our approach is capable of inpainting and denoising resulting in sharp, clean all-in-focus images. Our approach does not require any prior training or a large dataset, which makes it fast and effective. We evaluate our method on various kinds of images and compare it with other widely used methods. We demonstrate that our method can produce superior focal stacked images with higher accuracy and quality. This paper reveals a new and promising way of using a neural network to aid in microphotography, microscopy, and visual computing, by enhancing the quality of focal stacked images.

Surface, Skin, Facade, Countenance, Resistance, Chinchorro Mummies,Touch, Mark Making, Residue, Intuition, Repression, Indigestion, Disassemble, Blighted,Components, Body as Containers, Levels of Hierarchy, Absorption, Plastination, Modernism and Containment, Vanitas, Disembodied, Embodiment, Fragmentation, Arches, Gothic, Typology, Stacking of Cultures, Slippage.

Previous studies of the redox states of linear conjugated oligomers as models for polarons and bipolarons in conjugated polymers do not fully address the influence of intermolecular interactions on the electronic structure of conjugated systems in the solid state. Fusion of oligothiophenes onto a bicyclo[4.4.1]undecane core holds the conjugated oligomers in a permanent cofacial stack. One- and two-electron oxidation of the stacked oligomers affords mono(radical cation)s and dications that serve as models for polarons and bipolarons in p-doped conjugated polymers and demonstrates the effect of pi-stacking on the electronic structure of these species. Installation of phenyl-capped and ferrocenyl-capped oligothiophenes allows us to systematically vary pi-stacked oligomers and study intramolecular charge migration in other linear conjugated molecules.

We studied terahertz radiation from InN in our paper. We set up " Terahertz Time-Domain Spectroscopy system" and investigate Terahertz emission from InN. We take our sample(InN) in the rotation stage and we rotate different angle to detect the THz intensity data and wave shape and also the mechanisms of THz wave emitted. We research the influence from different background carrier density, band gap, mobility and structure(Zb-InN, W-InN) of InN to produce Terahertz radiation. Finally, we dicuss the THz amplitude and shape influenced from the internal surface field effect, Photo Dember effect, stacking fault, c-plane and m-plane from InN.

In the past several years, epitaxial graphene on silicon carbide has been transformed from an academic curiosity of social scientists to a leading candidate material to replace silicon in post-CMOS electronics. This has come with rapid development of growth technologies, improved understanding of epitaxial graphene on the polar faces of silicon carbide, and new device fabrication techniques. The contributions of this thesis include refinement and improved understanding of graphene growth on the silicon- and carbon-faces in the context of managed local silicon partial pressure, high-throughput epitaxial graphene thickness measurement and uniformity characterization by ellipsometry, observations of nearly ideal graphene band structures on rotationally stacked carbon-face multilayer epitaxial graphene, presentation of initial experiments on localized in situ chemical modification of epitaxial graphene for an alternate path to semiconducting behavior, and novel device fabrication methods to exploit the crystal structure of the silicon carbide substrate. The latter is a particularly exciting foray into three dimensional patterning of the substrate that may eliminate the critical problem of edge roughness in graphene nanoribbons.

The field of molecular electronics includes the study of conjugated oligomers and polymers that have significant potential for use in devices such as light emitting diodes (LEDS), field effect transistors (FETS), and photovoltaic solar cells. These materials may replace inorganic semiconductors in these devices, Achieving better device performance through lowering the band-gap and achieving higher field effect mobilities will benefit from a greater fundamental understanding of charge transfer through the aromatic subunits. π-stacking of segments of conjugated polymers has been identified as a key feature that influences the charge transfer through semiconducting organic materials. Optimizing the molecular architecture of conjugated polymers has the potential to provide materials with better charge mobility. While devices might benefit from materials that take advantage of π-stacking, access to π-stacked structures presents a synthetic challenge. 1,8-Disubstituted naphthalenes may serve as simple covalent bridging scaffolds which might hold conjugated oligomers in a π-stacked arrangement. The research described in this thesis focuses on the synthesis of well-defined phenylene ethynylene oligomers coupled to naphthalene to serve as experimental models of closely π-stacked aromatic units in conjugated polymers. The π-stacked molecules reported in this dissertation are characterized by NMR, IR, and mass spectrometry. The effects of π- stacking on the structure and behavior of conjugated oligomers are determined by X-ray crystallography, spectroscopy, and electrochemistry.

Non-covalent interactions are of great interest to chemists and biologists who study the molecular structure and function of biological systems, as well as those who seek to control, undo, or improve upon the efficiency of these systems with man-made chemical tools. The Iverson group has specifically applied noncovalent aromatic donor-acceptor interactions to biotic and abiotic aqueous systems through the use of the electron-rich 1,5-dialkoxynaphthalene (DAN) and electron-deficient 1,4,5,8-naphthalenetetracarboxylic diimide (NDI) moieties. Chapter 1 introduces and reviews the current state of self-assembly research, especially work conducted in aqueous media. Chapter 2 delineates the design and synthesis of a molecule that can self-assemble and form disulfide bonds, with the goal of creating higher-order structure. Chapter 3 comprises the design and synthesis of a series of pendant-NDI bisintercalators of DNA that are distinct from the backbone-incorporated intercalators previously employed in our laboratory. Chapter 4 contextualizes the term of art “pi-stacking,” reviewing the current state of knowledge of specific contributions to this effect and commenting on the putative uniqueness of the interaction. Theoretical and experimental work in the field is summarized. The work discussed in this dissertation serves to expand the scope of programmability of our DNA intercalators, to probe the higher-order assembly behavior of our donor-acceptor pair, and to clarify the term “pi-stacking,” lately overused, that imperfectly describes the interaction that gives both these systems their compelling binding properties. / text

The imminent emergence of the hydrogen fuel industry has resulted in an urgent mandate for very specific material testing. Although storage of pressurized hydrogen gas is both practical and attainable, demands for increasing storage pressures (currently around 70 MPa) continue to present unexpected material compatibility issues. It is imperative that materials commonly used in gaseous hydrogen service are properly tested for hydrogen embrittlement resistance. To assess material behavior in a pressurized hydrogen environment, procedures were designed to test materials for susceptibility to hydrogen embrittlement. Of particular interest to the field of high-pressure hydrogen in the automotive industry, austenitic stainless steels SUS 316 and 316L were used to validate the test programs. Tests were first performed in 25 MPa helium and hydrogen at room temperature and at -40°C. Tests in a 25 MPa hydrogen atmosphere caused embrittlement in SUS 316, but not in 316L. This indicated that alloys with higher stacking fault energies (316L) are more resistant to hydrogen embrittlement. Decreasing the test temperature caused slight embrittlement in 316L and significantly enhanced it in 316. Alternatively, a second set of specimens was immersed in 70 MPa hydrogen at 100°C until reaching a uniform concentration of absorbed hydrogen. Specimens were then loaded in tension to failure to determine if a bulk saturation of hydrogen provided a similar embrittling effect. Neither material succumbed to the effects of gaseous pre-charging, indicating that the embrittling mechanism requires a constant supply of hydrogen at the material surface rather than having bulk concentration of dissolved hydrogen. Permeation tests were also performed to ensure that hydrogen penetrated the samples and to develop material specific permeation constants. To pave the way for future work, prototype equipment was constructed allowing tensile or fatigue tests to be performed at much higher hydrogen pressures. To determine the effect of pressure on hydrogen embrittlement, additional tests can be performed in hydrogen pressures up to 85 MPa hydrogen. The equipment will also allow for cyclic loading of notched tensile or compact tension specimens for fatigue studies.