2,274 research outputs found

    Doctor of Philosophy

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    dissertationBuckling-restrained braces (BRBs) are widely used in new and existing buildings to enhance their performance during large earthquakes. The new generation BRB has connection plates welded perpendicular to core plates, which makes the manufacturing easier compared to current construction. The new generation BRB has two connection plates on each end, which makes the pinned end, bolted end, and welded end much easier to construct and connect the BRB to buildings. Nine full-scale experiments carried out in this research demonstrates the ability of new generation BRBs to perform equally well as current generation BRBs. Research has been done for the buckling force of the core plate and the contact force between concrete and core plate for conventional BRBs, but specific equations for buckling force and contact force considering the friction between concrete and core plates have been developed when the core plate buckles in a number of waves for strong-axis buckling. A theory based on the strut-and-tie model was developed to predict strong or weak axis buckling for a given BRB. In addition, finite element models were developed which are compared to the analytical results for determining the occurrence of strong-axis or weak-axis buckling, as well as the magnitude buckling load. Allowable ratio of lateral force to BRB axial compressive capacity for a certain casing length and cross-section is determined using finite element analysis, at which BRBs can deform up to 2% interstory drift without global buckling. Simulation of the hysteretic performance of the nine BRBs tested in full-scale experiments is carried out using finite element analysis with quasistatic cyclic loads, and the results are then compared to the experiments. Finally, the factors which effected the out-of-plane buckling of the gusset plate in one of the experiments are investigated and measures to prevent this are offered

    Cathedral From the Perspective of Reconstructive Postmodernism

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    Raymond Carver (1938-1988) is a famous American writer in the second half of the 20th century. He is very influential in the contemporary fiction field, who has been praised as “the American Chekhov”, “the greatest American short story writer after Hemingway” and “the greatest contributor to the revival of short story in the 1980s”. Cathedral, a collection of stories published in 1983, is Carver’s mature work nominated for Pulitzer Prize, which includes a short story named Cathedral.Carver’s short story Cathedral illustrates the alienation and imbalance of the human spirit brought about by modernism. Aiming at Raymond Carver’s short story Cathedral, this paper adopts the method of combining literature review and literary criticism to illustrate the main narrative features of Carver’s novels from the perspective of Reconstructive Postmodernism. In Carver’s opinion, when communicating with others, recognizing and accepting the difference between oneself and others, which also means integrating into the world of others, enables the isolated individual can truly communicate with the social partner outside the family. Through true acceptance and respect of others which has been externalized as the means of communication, the inner relationship between the self and others is rebuilt, and the spiritual dilemma can be got rid of, and the spiritual home of human beings is finally rebuilt to accomplish the overall ecological civilization of human society, which is of great significance to the construction of contemporary ecological civilization and the realization of harmony between man and nature

    The Development of Mathematical Model Consciousness in Junior Secondary Students: A Lesson Study of the Instruction of Congruent Triangles

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    The Compulsory Education Course Standards for Mathematics 2022 have highlighted the educational objectives of junior secondary mathematics by emphasizing the development of mathematical competence and practical learning. Model consciousness, as one of the fundamental mathematical competencies to be developed at the junior secondary level, can facilitate students’ comprehension of the universal application of mathematics. Teachers of mathematics in junior high school should construct effective classroom activities based on the cognitive qualities of their students in order to enhance their mathematical model consciousness and comprehension of the substance of mathematics knowledge. This paper is a lesson study of the education of Congruent Triangles, and its purpose is to investigate strategies for fostering mathematical model consciousness among junior high school pupils

    A double-distribution-function lattice Boltzmann method for bed-load sediment transport

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    The governing equations of bed-load sediment transport are the shallow water equations and the Exner equation. To embody the advantages of the lattice Boltzmann method (e.g., simplicity, efficiency), the three-velocity (D1Q3) and five-velocity (D1Q5) double-distribution-function lattice Boltzmann models (DDF-LBMs), which can present the numerical solution for one-dimensional bed-load sediment transport, are proposed here based on the quasi-steady approach. The so-called DDF-LBM means we use two distribution functions to describe the movement of the two components, respectively. By using the Chapman–Enskog expansion, the governing equations can be recovered correctly from the DDF-LBMs. To illustrate the efficiency of these, two benchmark tests are used, and excellent agreements between the numerical and analytical solutions are demonstrated. In addition, we show that the D1Q5 DDF-LBM has better accuracy compared to the Hudson’s method

    PFB-Diff: Progressive Feature Blending Diffusion for Text-driven Image Editing

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    Diffusion models have showcased their remarkable capability to synthesize diverse and high-quality images, sparking interest in their application for real image editing. However, existing diffusion-based approaches for local image editing often suffer from undesired artifacts due to the pixel-level blending of the noised target images and diffusion latent variables, which lack the necessary semantics for maintaining image consistency. To address these issues, we propose PFB-Diff, a Progressive Feature Blending method for Diffusion-based image editing. Unlike previous methods, PFB-Diff seamlessly integrates text-guided generated content into the target image through multi-level feature blending. The rich semantics encoded in deep features and the progressive blending scheme from high to low levels ensure semantic coherence and high quality in edited images. Additionally, we introduce an attention masking mechanism in the cross-attention layers to confine the impact of specific words to desired regions, further improving the performance of background editing. PFB-Diff can effectively address various editing tasks, including object/background replacement and object attribute editing. Our method demonstrates its superior performance in terms of image fidelity, editing accuracy, efficiency, and faithfulness to the original image, without the need for fine-tuning or training.Comment: 18 pages, 15 figure

    A Pan-Function Model for the Utilization of Bandwidth Improvement and PAPR Reduction

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    Aiming at the digital quadrature modulation system, a mathematical Pan-function model of the optimized baseband symbol signals with a symbol length of 4T was established in accordance with the minimum out-band energy radiation criterion. The intersymbol interference (ISI), symbol-correlated characteristics, and attenuation factor were introduced to establish the mathematical Pan-function model. The Pan-function was added to the constraints of boundary conditions, energy of a single baseband symbol signal, and constant-envelope conditions. Baseband symbol signals with the optimum efficient spectrum were obtained by introducing Fourier series and minimizing the Pan-function. The characteristics of the spectrum and peak-to-average power ratio (PAPR) of the obtained signals were analyzed and compared with the minimum shift keying (MSK) and quadrature phase-shift keying (QPSK) signals. The obtained signals have the characteristics of a higher spectral roll-off rate, less out-band radiation, and quasi-constant envelope. We simulated the performance of the obtained signals, and the simulation results demonstrate that the method is feasible

    A Method of Water Quality Assessment Based on Biomonitoring and Multiclass Support Vector Machine

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    AbstractIntegrating biological monitoring method with computer vision technology, acute toxicity test was performed to study the toxic effects of Cu2+ with different concentration on zebrafish (Danio rerio). The Behavioral response of school of fish in a tank was quantified and an early warning system was developed in the study. In the system, the real-time quantified data were saved to database and the Multiclass Support Vector Machine (SVM) was used to make comprehensive assessment according to behavioral difference of fish school in different toxicity environment. The prediction accuracies are satisfactory, which indicate that this approach is effectual for assessment of water quality

    Análisis de Ciclo de Vida de diferentes productos para conservación de comida

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    [ES] El ritmo acelerado de la sociedad actual ha generado cambios en nuestros hábitos alimenticios, aumentando el consumo de las comidas fuera del hogar. Muchas personas llevan sus comidas o simplemente un bocadillo al lugar de trabajo o al colegio con un trozo de papel aluminio o film transparente; o con un recipiente de plástico o una bolsa alimenticia. Por una parte, esto es debido a la comodidad y a la falta de tiempo durante los tiempos de descanso en los colegios o centros laborales. Por otra parte, por el ahorro económico, dado que comer, por ejemplo, en un restaurante todos los días supone un gasto importante. Sin embargo, aunque sean pequeñas cantidades de productos que consumimos nuestro día a día, desconocemos las consecuencias que conllevan al medio ambiente tanto para producirlos como para gestionarlos después de su uso. Por lo que disminuir sus impactos supone un reto para las industrias y también para los consumidores. Este trabajo analiza el ciclo de vida de los envoltorios de comida (papel de aluminio, papel film, fiambrera de plástico y bolsa alimenticio) que abarca desde la cuna hasta la tumba. Se utiliza la metodología definida en la norma ISO 14040, que contempla la definición del objetivo y alcance; el análisis del inventario de datos; la evaluación de los impactos ambientales; y la interpretación de los resultados. Para la comparación y evaluación de los datos se usará la base de datos Ecoinvent y el programa informático SimaPro. Finalmente se interpretará los impactos más significativos y la propuesta de medida para la reducción del producto más "perjudicial" para el medio ambiente.[CA] El ritme accelerat de la societat actual ha generat canvis en els nostres hàbits alimentaris, augmentant el consum dels menjars fora del llar. Moltes persones porten els seus menjars o simplement un entrepà al lloc de treball o al col·legi amb un tros de paper d'alumini o film transparent; o amb un recipient de plàstic o una bossa alimentària. D'una banda, açò és degut a la comoditat i a la falta de temps durant els temps de descans en els col·legis o centres laborals. D'altra banda, per l'estalvi econòmic, atés que menjar, per exemple, en un restaurant tots els dies suposa un gasto important. No obstant això, encara que siguen xicotetes quantitats de productes que consumim el nostre dia a dia, desconeixem les conseqüències que comporten al medi ambient tant per a produir-los com per a gestionar-los després del seu ús. Pel que disminuir els seus impactes suposa un repte per a les indústries i també per als consumidors Este treball analitza el cicle de vida dels embolcalls de menjar (paper d'alumini, paper film, portaviandes de plàstic i bossa alimentari) que comprén des del bressol fins a la tomba. S'utilitza la metodologia definida en la norma ISO 14040, que contempla la definició de l'objectiu i abast; l'anàlisi de l'inventari de dades; l'avaluació dels impactes ambientals; i la interpretació dels resultats. Per a la comparació i avaluació de les dades s'usarà la base de dades Ecoinvent i el programa informàtic SimaPro. Finalment s'interpretarà els impactes més significatius i la proposta de mesura per a la reducció del producte més perjudicial per al medi ambient.[EN] The pace of current society has produced changes in their eating habits, the consumption of meals outside the home. Many people bring their meals or simply a snack to the workplace or school with a piece of aluminum foil or transparent film; or with a plastic container or a food bag. On the one hand, this is due to the comfort and lack of time during rest periods in schools or in the central work days. On the other hand, for the economic savings, since eating, for example, in a restaurant every day is an important expense. However, even if they are small quantities of products that we consume, we show our day to day, we do not know the consequences that entail to the environment both to produce them and to manage them after their use. So, reducing their impacts is a challenge for industries and also for consumers. This document analyzes the study of the life cycle analysis of food wrappers (aluminum foil, plastic wrap, plastic lunch box and food bag) from the cradle to the grave. The methodology defined in the ISO 14040 standard is used, which contemplates the definition of the objective and scope; the analysis of the data inventory; the evaluation of environmental impacts; and the interpretation of the results. For the comparison and evaluation of the data, the Ecoinvent database and the SimaPro software will be used. Finally, the most significant impacts and the proposed measure for the reduction of the most "harmful" product for the environment will be interpreted.Xu, W. (2018). Análisis de Ciclo de Vida de diferentes productos para conservación de comida. http://hdl.handle.net/10251/114367Archivo delegad
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