The focus of this dissertation is the existence, stability, and resulting dynamical evolution of localized stationary solutions to Nonlinear Schr¨odinger (NLS) equations with periodic confining potentials in 2(+1) dimensions. I will make predictions about these properties based on a discrete lattice model of coupled ordinary differential equations with the appropriate symmetry. The latter has been justified by Wannier function expansions in a so-called tight-binding approximation in the appropriate parametric regime. Numerical results for the full 2(+1)-D continuum model will be qualitatively compared with discrete model predictions as well as with nonlinear optics experiments in optically induced photonic lattices in photorefractive crystals. The predictions are also relevant for BECs (Bose-Einstein Condensates) in optical lattices.

<p> Trusses and Vierendeel girders are usually built from a single chord HSS "Hollow Structural Sections", but the largest HSS size as produced in Canada may limit its use for longer span applications. Therefore, the possibility of using double chord sections to enable the use of HSS for longer span trusses without the need for manufacturing new larger sections, presented itself. </p> <p> A new concept utilizing double chord square hollow sections in welded K-joints of Warren trusses is described. The experimental results of 29 tests are reported, including four connections types — standard, channel, bolted and back-to-back. The latter type comprised of gapped, overlapped and gapped with connecting stiffener plates. </p> <p> The results indicate that the standard type is an excellent joint in both strength and stiffness. The channel type is generally susceptible to twisting. It was found adequate only when a significant increase in chord thickness (≃ 50%) was employed. The bolted connection appears to hold promise when on-site assembly of large trusses is necessary. Its performance was further improved by connecting the chords with small tie bars. The back-to-back type needed to be reinforced or fully overlapped to develop full branch member strength. </p> <p> The double chord system of connection reveals itself to be much superior in strength to an equivalent single chord joint. </p> <p> The effects of eccentricity, branch member to chord angle, and chord preloading were investigated. Interaction formulae are presented for the standard and channel type joints which suffered from a chord failure at the connection. </p> <p> Results of four T-type connections using the double chord concept are also reported and were recently published in the ASCE (8). </p> / Thesis / Doctor of Philosophy (PhD)

The Association of Research Libraries (ARL) provides an option for librarians to administer a combination of LibQUAL+® and LibQUAL+® Lite to measure users' perceptions of library service quality. LibQUAL+® Lite is a shorter version of LibQUAL+® that uses planned missing data in its design. The present study investigates the loss of information in commonly administered proportions of LibQUAL+® and LibQUAL+® Lite when compared to administering LibQUAL+® alone. Data from previous administrations of LibQUAL+® protocol (2005, N = 525; 2007, N = 3,261; and 2009, N = 2,103) were used to create simulated datasets representing various proportions of LibQUAL+® versus LibQUAL+® Lite administration (0.2:0.8, 0.4:0.6. 0.5:0.5, 0.6:0.4, and 0.8:0.2). Statistics (i.e., means, adequacy and superiority gaps, standard deviations, Pearson product-moment correlation coefficients, and polychoric correlation coefficients) from simulated and real data were compared. Confidence intervals captured the original values. Root mean square errors and absolute and relative biases of correlations showed that accuracy in the estimates decreased with increase in percentage of planned missing data. The recommendation is to avoid using combinations with more than 20% planned missing data.

Folketshus och en plats för de lokala producenterna att sälja de lokala produkterna i hjärtat av Nynäshamn. Jag valde denna plats för att den av många uppfattas som osäker och mörk. Genom att skapa en mer levande och användbar miljö kan den outnyttjade grusplanen få nytt liv och bli en tillgång för hela samhället.Genom att skapa en sådan plats för hållbar livsmedelsproduktion i Nynäshamn skulle det inte bara gynna de lokala producenterna och konsumenterna, utan även ge möjlighet till kunskapsdelning och främja samarbete inom sektorn. Det skulle vara en möjlighet att stärka Nynäshamns image som en hållbar och progressiv stad och dra till sig intresserade besökare och turister som är angelägna om att stödja hållbara initiativ och njuta av kvalitetsprodukter från närområdet. / A community center and a place for the local producers to sell the local products in the heart of Nynäshamn. I chose this place because it is perceived by many as unsafe and dark. By creating a more vibrant and useful environment, the unused gravel pitch can be given new life and become an asset for the whole community. By creating such a place for sustainable food production in Nynäshamn, it would not only benefit the local producers and consumers, but also provide an opportunity for knowledge sharing and promote cooperation within the sector. It would be an opportunity to strengthen Nynäshamn's image as a sustainable and progressive city and attract interested visitors and tourists keen to support sustainable initiatives and enjoy quality products from the local area.

Hur fungerar förortscentrumen när världen ständigt moderniseras och fysiska butiker minskar? Hur kan man utveckla de befintliga centrumstrukturerna, och vilka andra typer av funktioner kan man lägga till som skulle kunna vara mer relevanta idag? Med det här projektet har jag velat undersöka hur olika typer offentliga rum och funktioner i en centrumanläggning kan fungera tillsammans, och ge upphov till en ökad trygghetskänsla och skapandet av nya mötesplatser. Platsen för projektet är Sätra som ligger sydväst om Stockholms innerstad. Sätra byggdes upp under 60-talet med Sätra centrum som stadsdelscentrum med all service samlad i en enda byggnad, byggd över tunnelbanans spår och hopbyggd med tunnelbanans stationsbyggnad. På grund av centrumets placering och bristande kvalité har förnyelse av Sätra centrum diskuteras flera gånger under årens lopp. I det nuvarande förslaget från Stockholms stad föreslås det att den befintliga centrumanläggningen ska rivs och ersättas av ett publikt utomhustorg, kringbyggt av fyra kvarter med cirka 600 bostäder och lokaler i samtliga bottenvåningar, något detta projekt ifrågasätter. Projektet föreslår en alternativ planering av området och min tanke varit att fokusera på skapa mötesplatser där människor kan mötas på olika sätt och samtidigt känna trygghet. Jag har velat att arkitekturen och programmet ska tillåta pauser och erbjuda platser för människor att vänta på, stanna upp och mötas. Målet har varit att ge människorna i Sätra anledningar till att spendera tid i det nya centrumet, inte bara passera till och från tunnelbanan. / What do we do with the suburban shopping centers when the world is modernizing and physical stores are reducing? How can we develop the already existing structures, what other kind of functions could we add that would be more relevant today?With this project, I wanted to explore how different types of public spaces and functions in a suburban center facility can work together, and give rise to a greater sense of security and the creation of new meeting places. The site for the project is Sätra, located southwest of Stockholm's inner city. Sätra was built during the 1960s with Sätra centrum as a city center with all services gathered in a single building, built over the metro tracks and built together with the metro station building. Due to the center's problematic placement and lack of quality, renewal of Sätra centrum has been discussed several times over the years. In the current proposal from the City of Stockholm, it is proposed that the existing center facility will be demolished and replaced by a public outdoor square, surrounded by four blocks with about 600 apartments and premises in the ground floors, which this project questions.The project proposes an alternative planning of the area and my idea has been to focus on creating meeting places where people can meet in different ways and at the same time feel safe. I wanted the architecture and the program to allow breaks and offer places for people to wait, stop and meet. The goal has been to give the people of Sätra reasons to spend time in the new city center, not just pass by it on their way to the metro.

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