Search results for "parametric"
showing 10 items of 980 documents
Regression analysis to design a solar thermal collector for occasional use
2020
Abstract Optimal design of a solar thermal system is necessary to minimize payback time and to diffuse renewable energy use for Domestic Hot Water production in residential areas. More accurate design is crucial in the case of seasonal or occasional use of the system; indeed, the standard criteria generally applied to a design system for continuous use, can lead to considerable over-sizing. To speed up the design phase and to help the planner in the identification of the best solution without any complex evaluation or long computational time, it would be interesting to have available a simpler method than the standard procedures, but one that is reliable and accurate for the evaluation of t…
Weibull Prediction Limits for a Future Number of Failures Under Parametric Uncertainty
2012
In this paper, we present an accurate procedure, called “within-sample prediction of order statistics,” to obtain prediction limits for the number of failures that will be observed in a future inspection of a sample of units, based only on the results of the first in-service inspection of the same sample. The failure-time of such units is modeled with a two-parameter Weibull distribution indexed by scale and shape parameters β and δ, respectively. It will be noted that in the literature only the case is considered when the scale parameter β is unknown, but the shape parameter δ is known. As a rule, in practice the Weibull shape parameter δ is not known. Instead it is estimated subjectively …
Radiographic Investigation of Location and Angulation of Curvatures in Human Maxillary Incisors
2008
The aim of this radiographic study was to evaluate the degree and location of root canal curvatures of human maxillary incisors. A total of 286 extracted human maxillary incisors (145 central and 141 lateral incisors) were included in this investigation. Exclusion criteria were teeth with extensive carious lesions, restorations, and root canal treatment. For this in vitro study, the teeth were fixed in a special device and digitally x-rayed with the parallel technique. The distances from the cementoenamel junction (CEJ) to the first curvature and the according angle were recorded. The results were analyzed descriptively, and p values were calculated with the Wilcoxon Mann-Whitney test. The …
On thermo-mechanical issues induced by irradiation swelling inside the back-plate of the IFMIF target assembly
2011
Abstract Within the framework of the IFMIF R&D program and in close cooperation with ENEA-Brasimone, at the Department of Nuclear Engineering of the University of Palermo a research campaign has been launched to investigate the thermo-mechanical issues potentially induced by irradiation swelling in the threaded connections between frame and back-plate of IFMIF target assembly. The main aim of the research campaign has relied in the assessment of the maximum swelling-induced volumetric strain that may be accepted in order to allow screws to withstand thermo-mechanical stresses and work in safe conditions or to avoid unduly high unscrewing torques during back-plate remotely handled maintenanc…
Information systems for the conservation and fruition of cultura heritage. The church of Santa Trinità di Delia
2016
Lo studio descrive il processo di conoscenza avviato su uno degli esempi monumentali più rappresentativi dell’architettura normanna della prima metà del XII sec. in Sicilia: la chiesa della Trinità di Delia a Castelvetrano (TP). Le fasi del rilievo e della rappresentazione 3D degli elementi costruttivi e decorativi seguono un approccio parametrico costituendo un sistema informativo implementabile di supporto per successivi interventi di restauro conservativo della struttura. Il workflow è struturato in modo tale da impiegare tecnologie hardware / software low-cost, descrivendo metodiche procedurali di elaborazione dati trasferibili all’attività professionale. The study describes the knowled…
Luigi Moretti, from history to parametric architecture
2018
In this article we aim to give new light on the thinking of Luigi Moretti, first to have formulated the concept of parametric architecture, comparing it with those of some contemporary architectural theorists and designers. The latest researches on materials and form-finding experiences have shown a new relationship between form and structure, Moretti understood it before the advent of the internet. Moretti's parameter stems from the architectural tradition, as Carpo sees relations between parametric design and history. Moretti’s Parametric architecture is interdisciplinary, open to science in ways that we are only now understanding. We, therefore, believe that recovering Moretti’s methods …
Design and Digital Fabrication of a Parametric Joint for Bamboo Sustainable Structures
2019
The study deepens the design of a joining system for bamboo spatial structure by proposing new and advanced solutions that guarantee maximum freedom of composition to the designer. The joint allows to determine and control parametrically the adaptability to any spatial grid configuration of culms with heterogeneous dimensions. Despite the bamboo being one of the main natural building materials in the field of sustainable architecture, currently, it is not used enough due to the lack of adequate connection systems. Bamboo is a rapidly growing renewable resource, naturally available, which is quite strong and lends itself to structural applications. The paper proposes an innovative approach t…
Generative design and parametric / topological optimization of cellular structures bio-inspired by additive manufacturing
2022
Biomimicry is the practice of learning from nature and imitating its different functionalities. Nature proposes complex forms and objects which inspired designers and engineers to conceive and find solutions for their engineering problems. The fabrication of these complex objects is particularly assured by the different Additive Manufacturing (AM) techniques. Generally, biomimicry can be addressed at different levels, forms, textures, and behaviors, but in AM, it is presented under two main types. The first is the customization of parts (medical prosthesis, implants or custom sport equipments). And the second consists in the optimization for specific properties such as stiffness and lightne…
Study on difficulties and misconceptions with modern type systems
2014
Functional programming is often presented as an advantageous programming paradigm by its advocates, but many students and teachers consider it to be hard to learn. One particular hurdle in learning functional programming is mastering the modern type systems employed in these languages. In this article, we identify student difficulties with means of multiple choice questions embedded into the on-line materials of an introductory functional programming course. The most prevalent misconceptions were confusing with parametric polymorphism with subtyping, the assigning too much meaning to variables names, and confounding general language patterns with special cases.
Non-crossing parametric quantile functions: an application to extreme temperatures
2019
Quantile regression can be used to obtain a non-parametric estimate of a conditional quantile function. The presence of quantile crossing, however, leads to an invalid distribution of the response and makes it difficult to use the fitted model for prediction. In this work, we show that crossing can be alleviated by modelling the quantile function parametrically. We then describe an algorithm for constrained optimisation that can be used to estimate parametric quantile functions with the noncrossing property. We investigate climate change by modelling the long-term trends of extreme temperatures in the Arctic Circle.