Baigiamajame magistro darbe buvo lyginama ofsetinės ir fleksografinės spaudos kokybė spausdinant spalvines kontrolines skales, spalvų sutapdinimo kryžius, skiriamosios gebos elementus. Atspaudai buvo atspausdinti ofsetine lapine spaudos mašina ir siauraritinine fleksografinės spaudos mašina su centriniu spaudos cilindru. Mikroskopu buvo matuojamas spalvų sutapdinimo tikslumas, skiriamosios gebos elementų dydis. Densitometru buvo matuojamas atskirų ir binarinių spalvų rastrinių taškų santykinis plotas bei įvertintas gradacinis tikslumas. Pagal gautus kiekybinius rezultatus nustatyta, jog fleksografinės spaudos kokybė prastesnė negu ofsetinės spaudos. Darbą sudaro šios dalys: įvadas, literatūros apžvalga, kokybės reikalavimai, problemos analizė, eksperimento eiga ir rezultatų analizė, išvados, literatūros sąrašas. Darbo apimtis – 80 p. teksto be priedų, 65 pav., 43 lentelės, 18 literatūros šaltinių. / In master thesis was compared the offset and flexographic printing quality. Printing quality was evaluated using control strips, register crosses, resolving power test elements. Jobs were printed with offset sheet-fed printing press and flexographic narrow web press with central impresion cilinder. Register accuracy and resolving power were investigated using microscope. Dot area of single and binary colors wes measured with densitometer and halftone graduation characteristics were evaluated. On the basis of quantitative results it was determined that offset printing quality in comparison with flexography is higher. Master thesis comprise of folowing chapters: literature review, quality requirements, experimental, results and discusion, conclusions, references. Amount – 80 pages, 65 figures, 43 tables, 18 references.

La qualité d'impression est une notion difficile à maîtriser. L'œil est souvent utilisé en industrie comme outil permettant de juger la qualité d'un film polymère imprimé. Afin d'atteindre un niveau supérieur de qualité, il est nécessaire de trouver un moyen pour quantifier la qualité d'impression, et ainsi permettre d'atteindre soit une qualité dite « point par point », soit une qualité dite « all-over ». Plusieurs éléments sont nécessaires à cette quantification : une image en microscopie optique de l'échantillon, ainsi qu'une valeur d'intensité moyenne et d'homogénéité de couleur, que l'on obtient grâce à un rugosimètre confocal. Ainsi nous avons pu définir, pour un support mis en forme par calandrage et un support mis en forme par enduction, les paramètres majeurs agissant sur la qualité d'impression. En termes de procédé, il apparaît que la vitesse d'impression et la pression du cylindre presseur influencent grandement l'imprimabilité. Au niveau des matériaux utilisés, la viscosité et la tension de surface de l'encre ont un effet important alors qu'en termes de support, un film calandré sera plus sensible aux variations des différents paramètres qu'un film enduit. / Printing quality idea is hard to control. In industry, eye is often used to judge the quality of a printed polymer film. In order to get a new level in terms of printing quality and get “point by point” or “all-over” quality, it is necessary to find a way to quantify printing quality. Some elements are important concerning the quantification of the printing quality: an optical microscopic image, a value of the average intensity and a value on the homogeneity of the color. We can define, for a calendered and a coated substrate, the main parameters acting on the printing quality. Printing speed and pressure of the rubber roll are the two main process parameters to act, viscosity and surface tension of the ink are the two main ink properties to act, while the calendered substrate is more sensitive to the variation of the parameters than the coated one.

<p>3D printing of concrete (3DPC) has been demonstrated to be a potential and viable solution for different infrastructure applications considering its multiple benefits and the continuous advances in achieving an advanced manufacturing process, using innovative materials, and using unique approaches to demonstrate high-performance characteristics. Still, some challenges remain to be addressed as this technology advances through the stages of prototyping, validation, and testing; looking to establish itself as an alternative to cast concrete for the mass production of civil infrastructure. The research presented in this dissertation is focused on the influence of the fabrication process of 3D-printed concrete on three relevant aspects for its deployment in large-scale scenarios. These aspects include the scalability of mixture development for different printing systems, the mechanical performance of reinforced 3D-printed elements, and the initial evaluation of durability properties. This research aims to contribute to the development of strategies to understand the effects of the mixture composition and the use of supplementary cementitious materials (SCMs) in the process of mixture development to enhance the printability characteristics, fresh state properties, and durability properties of these materials. Furthermore, the incorporation of novel reinforcement alternatives and controlled architectures, in addition to the study of the transport properties of 3D-printed elements can lead to advances in the use of 3D-printed concrete in structural applications.</p>

<p>Print quality (PQ) is one of the most significant issues with electrophotographic printers. There are many reasons for PQ issues, such as limitations of the electrophotographic process, faulty printer components, or other failures of the print mechanism. These reasons can produce different PQ issues, like streaks, bands, gray spots, text fading, and color fading defects. It is important to analyze the nature and causes of different print defects to more efficiently repair printers and improve the electrophotographic process. </p> <p><br></p> <p>We design a general framework for print quality detection and analysis of customer content. This print quality analysis framework inputs the original digital image saved on the computer and then the scanned image. This framework includes two main modules: image pre-processing, print defects feature vector extraction, and classification. The first module, image pre-processing, includes image registration, color calibration, and region of interest (ROI) extraction. The ROI extraction part is designed to extract four different kinds of ROI from the digital master image. Because different ROIs include different print defects, for example, the symbol ROI includes the text fading defect, and the raster ROI includes the color fading defect. The second module includes different ROI print defects detection and analysis algorithms. We classify different ROI print defects using their feature vector based on their severity. This module proposed four important defects detection methods: uniform color area streak detection, symbol ROI color text fading detection, raster ROI color fading detection using a novel unsupervised clustering method, and raster ROI streak detection. We will introduce the details of these algorithms in this thesis. </p> <p><br></p> <p>We will also show two other interesting print quality projects: print margin skew detection and print velocity simulation and estimation. Print margin skew detection proposes an algorithm that uses the Hough Lines Detection algorithm to detect printing margin and skew errors based on factual scanned image verification. In the print velocity simulation and estimation project, we propose a print velocity simulation tool, design a specific print velocity test page, and design a print velocity estimation algorithm using the dynamic time warping algorithm. </p>