Academic literature on the topic 'Discrete ply model'
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Journal articles on the topic "Discrete ply model"
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Serra, Joël, Christophe Bouvet, Bruno Castanié, and Caroline Petiot. "Scaling effect in notched composites: The Discrete Ply Model approach." Composite Structures 148 (July 2016): 127–43. http://dx.doi.org/10.1016/j.compstruct.2016.03.062.
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Adam, Louis, Christophe Bouvet, Bruno Castanié, Alain Daidié, and Elodie Bonhomme. "Discrete ply model of circular pull-through test of fasteners in laminates." Composite Structures 94, no. 10 (October 2012): 3082–91. http://dx.doi.org/10.1016/j.compstruct.2012.05.008.
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Chen, Hailong, and Yongming Liu. "Deformation and failure analyses of cross-ply laminates using a nonlocal discrete model." Composite Structures 152 (September 2016): 1007–13. http://dx.doi.org/10.1016/j.compstruct.2016.06.054.
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Cui, Xiaodong, Eugene Fang, and Jim Lua. "A discrete crack network toolkit for Abaqus for damage and residual strength prediction of laminated composites." Journal of Composite Materials 51, no. 10 (July 18, 2016): 1355–78. http://dx.doi.org/10.1177/0021998316659914.
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The main objective of this article is to exploit a phantom paired element based discrete crack network toolkit for predicting the damage progression and residual strength of laminated composites without and with a hole under tension and compression. Both intra-ply matrix cracking and inter-ply delamination are considered under a co-simulation framework in the discrete crack network toolkit. A mesh-independent kinematic description of discrete matrix cracks is accomplished via user-defined phantom paired solid elements to capture the initiation and evolution of fiber orientation dependent matrix cracking. In-ply matrix crack initiation is realized by inserting a crack along the fiber direction when a matrix driven failure criterion is satisfied and a cohesive injection along the matrix crack interface is applied to account for energy dissipation during matrix crack opening. The delamination failure mode is characterized by applying Abaqus’ cohesive interaction at ply interfaces. The non-linear shear behavior is introduced by employing a power law based curve-fit model and the fiber failure is described using a continuum damage mechanics based model. Both the blind and recalibrated predictions are performed for specimens of three different layups under the Air Force Tech Scout 1 program. The predicted damage progression and the load displacement curves are compared with the testing results provided by the Air Force Research Laboratory.
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Mahmud, Jamaluddin, Wahyu Kuntjoro, and Aidah Jumahat. "Failure Analysis of Fiber Reinforced Composite Materials Used in Malaysian Industries." Scientific Research Journal 4, no. 2 (December 31, 2007): 41. http://dx.doi.org/10.24191/srj.v4i2.5658.
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The main objective of this paper is to determine the curves bounding the actual load carrying capacity in terms of the First Ply Failure and the Last Ply Failure of composite materials used in Malaysian Industries. A mathematical model and computational model are presented for the analysis. Higher Order Shear Deformation plate theory is employed to predict the deformation of the plate. The selected material properties through thickness is used and accommodated by a discrete layer approach. A program based on finite element method is developed using Fortran-90 to determine the lamina stresses. These stresses are then used in the present failure model to determine the First Ply Failure and Last Ply Failure, by progressively reducing the stiffness of the laminas. Finally, the First Ply Failure and Last Ply failure results are analysed, in terms of lower and upper bound within which the true load carrying capacity lies.
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Mahmud, Jamaluddin, Wahyu Kuntjoro, and Aidah Jumahat. "Failure Analysis of Fiber Reinforced Composite Materials Used in Malaysian Industries." Scientific Research Journal 4, no. 2 (December 31, 2007): 41. http://dx.doi.org/10.24191/srj.v4i2.9343.
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The main objective of this paper is to determine the curves bounding the actual load carrying capacity in terms of the First Ply Failure and the Last Ply Failure of composite materials used in Malaysian Industries. A mathematical model and computational model are presented for the analysis. Higher Order Shear Deformation plate theory is employed to predict the deformation of the plate. The selected material properties through thickness is used and accommodated by a discrete layer approach. A program based on finite element method is developed using Fortran-90 to determine the lamina stresses. These stresses are then used in the present failure model to determine the First Ply Failure and Last Ply Failure, by progressively reducing the stiffness of the laminas. Finally, the First Ply Failure and Last Ply failure results are analysed, in terms of lower and upper bound within which the true load carrying capacity lies.
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Serra, J., A. Trellu, C. Bouvet, S. Rivallant, B. Castanié, and L. Ratsifandrihana. "Combined loadings after medium velocity impact on large CFRP laminated plates: Discrete ply model simulations." Composites Part C: Open Access 6 (October 2021): 100203. http://dx.doi.org/10.1016/j.jcomc.2021.100203.
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McCartney, L. N. "Physically based damage models for laminated composites." Proceedings of the Institution of Mechanical Engineers, Part L: Journal of Materials: Design and Applications 217, no. 3 (July 1, 2003): 163–99. http://dx.doi.org/10.1177/146442070321700301.
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The computing power that is available for engineering calculation continues to grow at a dramatic pace. Engineers in industry want to have seamless models that can be used to design across the scale range from atoms to structures, including simulation of the manufacturing process. A limited aspect of this wish is the requirement to deal effectively with the progressive growth of microstructural damage in composites and its effect on both property degradation and the catastrophic failure event. This paper reviews progress that is being made at the National Physical Laboratory (NPL) with the development and validation of physically based damage growth models for laminated composites. The review includes: (a) prediction of undamaged ply properties determined from the properties of the fibre and the matrix, with emphasis on comparison of analytical models with each other, and with finite and boundary element solutions; (b) discussion of various stress transfer models, and their validation, that have been developed for application to the prediction of the properties of composite laminates having ply crack damage; (c) prediction of ply cracking in multiple-ply cross-ply laminates subject to triaxial loading (without shear) and bending; (d) prediction of ply cracking in general symmetric laminates subject to combined triaxial loading and in-plane shear loading; (e) consideration in a damage mechanics context of progressive ply crack formation in general symmetric laminates subject to thermal residual stresses and general in-plane loading, where an important new methodology is described that results from attempting to develop a continuum damage model from a physically based discrete ply cracking model based on energy concepts; (f) discussion of how the models might be integrated into finite element analysis (FEA) systems to enable strain softening in structures to be adequately modelled. The paper also includes statements concerning the status of the various models in relation to alternative approaches, and to model validation.
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Wang, Yanfeng, and Qi Wu. "A Microscale Analysis of Thermal Residual Stresses in Composites with Different Ply Orientations." Materials 16, no. 19 (October 6, 2023): 6567. http://dx.doi.org/10.3390/ma16196567.
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Composites, such as fiber-reinforced plastics, are produced using layering prepregs with varying ply orientations to achieve enhanced mechanical properties. However, this results in intricate residual stresses, which are influenced by the forming process and ply orientation. In this study, three representative microscopic models—featuring discrete fiber and resin—represent unidirectional, cross-ply, and angle-ply laminates. These models underwent simulations under three different cooling histories using the finite element method. The findings suggest that ply orientation does not significantly influence temperature distribution. However, it significantly impacts the von Mises stress in the fiber closest to the interface between two stacked laminae. This differs from the inter-laminar stresses determined with the macroscopic lamination model. Apart from the free edge, which exhibits a complex stress distribution, the von Mises stress within a unit cell displays a recurring pattern. The magnitude of the von Mises stress decreases as the ply orientation angle increases and shifts when a temperature gradient is present throughout the composite’s thickness. This study provides valuable insights into the mechanics of residual stresses at the microscopic level and highlights potential defect areas influenced by these stresses.
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Jäger, Sebastian, Anthony Pickett, and Peter Middendorf. "A Discrete Model for Simulation of Composites Plate Impact Including Coupled Intra- and Inter-ply Failure." Applied Composite Materials 23, no. 2 (July 21, 2015): 179–95. http://dx.doi.org/10.1007/s10443-015-9455-2.
Full textDissertations / Theses on the topic "Discrete ply model"
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Soufri, Ayoub. "Multi-impact behavior of composite structures : experimental and numerical approach." Electronic Thesis or Diss., Bourgogne Franche-Comté, 2023. http://www.theses.fr/2023UBFCK038.
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Les matériaux composites sont largement utilisés dans le domaine des transports en raison de leurs propriétés mécaniques spécifiques élevées. Cependant, au cours de leur cycle de vie, ils peuvent subir une dégradation significative de leurs propriétés mécaniques lorsqu'ils sont soumis à des chargements d'impacts. Les dommages induits par des impacts se manifestent sous différentes formes telles que la rupture des fibres, la fissuration matricielle, la décohésion fibres/matrice et le délaminage. L'étude du comportement aux impacts des structures composites a suscité une attention importante dans la littérature. Cependant, ces études se rapportent généralement au cas d'un seul impact ou d'impacts répétés. Peu de travaux se sont intéressés au cas d'impacts multiples, même s'ils sont plus proches des conditions réelles de service, comme dans les cas de chute de grêlons ou de projection d'objets externes tels que les gravillons présents sur les routes, les impacts d'oiseaux, etc. Dans cette thèse, nous présentons des méthodes expérimentales et numériques robustes pour le suivi in-situ et post-mortem des endommagements suite aux différents cas d'impacts possibles : mono-impact, impacts répétés, séquentiels, simultanés, etc. Ce travail a consisté dans un premier temps à développer un banc d'essai unique « canon à air comprimé ». Ensuite, un dialogue (essais expérimentaux-calculs numériques) a été assuré afin de mieux comprendre les phénomènes en jeu dans les cas de multi-impacts, pour finalement atteindre les performances maximales des matériaux compositesComposite materials are widely used in the transportation field due to their high specific mechanical properties. However, during their life cycle, they can undergo significant degradation of their mechanical properties when subjected to impact loading. Impact-induced damage occurs in various forms, such as fiber breakage, matrix cracking, fiber/matrix decohesion and delamination. The study of the impact behavior of composite structures has attracted considerable attention in the literature. However, these studies generally relate to the case of a single impact or repeated impacts. Few studies have focused on the case of multiple impacts, even though these are closer to actual service conditions, as in the case of falling hailstones or the projection of external objects such as road gravels, bird strikes, etc. In this thesis, we present robust experimental and numerical methods for in-situ and post-mortem monitoring of damage following the various possible impact cases: single-impact, repeated, sequential, simultaneous impacts, etc. The first phase of the project involved the development of a unique "compressed air cannon" test bench. Then, a dialogue (experimental tests-numerical computations) was ensured to better understand the phenomena involved in multi-impact cases, to finally reach the maximum performance of composite materials
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Darby, Kimberly Jeanne. "Consumer Preferences for Locally-Grown Berries: A Discrete Choice Model Estimating Willingness-To-Pay." The Ohio State University, 2006. http://rave.ohiolink.edu/etdc/view?acc_num=osu1392043198.
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Balogh, Péter, Daniel Bekesi, Matthew Gorton, József Popp, and Péter Lengyel. "Consumer willingness to pay for traditional food products." Elsevier, 2016. http://dx.doi.org/10.1016/j.foodpol.2016.03.005.
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Reflecting the growing interest from both consumers and policymakers, and building on recent developments
in Willingness to Pay (WTP) methodologies, we evaluate consumer preferences for an archetypal
traditional food product. Specifically we draw on stated preference data from a discrete choice
experiment, considering the traditional Hungarian mangalitza salami. A WTP space specification of the
generalized multinomial logit model is employed, which accounts for not only heterogeneity in preferences
but also differences in the scale of the idiosyncratic error term. Results indicate that traditional food
products can command a substantial premium, albeit contingent on effective quality certification,
authentic product composition and effective choice of retail outlet. Promising consumer segments and
policy implications are identified. (authors' abstract)
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Guimarães, Camila. "Avaliação das preferencias dos pacientes por atributos de risco/benefício do tratamento insulínico no diabetes: um modelo de escolha discreta." Universidade de São Paulo, 2009. http://www.teses.usp.br/teses/disponiveis/60/60134/tde-01062009-142902/.
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Utilizou-se um modelo de escolha discreta (MED) para avaliar as preferências e disposição-a-pagar (DAP) dos pacientes por diferentes atributos de risco-benefício do tratamento insulínico, entre eles a via de administração da insulina. Através de uma revisão da literatura, consulta com especialistas, e do desenvolvimento de um estudo qualitativo utilizando as técnicas de entrevistas individuais e grupos focais, os atributos (e níveis) mais importantes do tratamento insulínico foram identificados, sob o ponto de vista dos pacientes. Os atributos incluídos no MED foram: controle da glicemia de jejum, número de episódios de hipoglicemia, ganho de peso, via de administração para as insulinas de ação longa e rápida, e custo do tratamento. Pares de opções de tratamentos insulínicos hipotéticos contendo diferentes níveis dos atributos foram apresentados aos pacientes com DM1 ou DM2, e lhes foi solicitado que, para cada cenário, eles escolhessem a alternativa de sua preferência. Dados demográficos, nível sócio-econômico (NSE) e informações relacionadas ao diabetes também foram coletados. Para a análise dos dados utilizou-se um modelo logit condicional de regressão e modelos segmentados foram posteriormente utilizados para a análise das sub-populações. Um total de 274 questionários foram incluídos na análise final dos dados. A idade média (± DP) dos participantes foi de 56.7 ± 12.98 anos, e 53% eram homens. Quarenta e nove por cento dos participantes eram usuários de insulina e 47 eram portadores de DM1. O tratamento insulínico ideal, sob o ponto de vista dos pacientes, resultaria em um melhor controle glicêmico, menos reações adversas, menor custo, e seria administrado por via oral. Houve uma forte preferência e uma DAP mais elevada por um melhor controle glicêmico, seguido pelos atributos de risco ganho de peso e episódios de hipoglicemia. Surpreendentemente, a via de administração da insulina foi o atributo menos valorizado. A estratificação social revelou que pacientes com alta renda anual familiar apresentaram uma DAP mais elevada por um melhor controle glicêmico e por menos reações adversas em relação aos grupos com rendas inferiores. Ainda, quanto mais alto o nível de renda, maior o desejo por uma insulina oral, enquanto a via inalada torna-se menos importante para os pacientes. A estratificação da amostra pelo uso de insulina e tipo de diabetes revelaram uma forte aversão pela via subcutânea pelos não-usuários de insulina e pacientes com DM2. Tais resultados sugerem a existência de uma importante barreira psicológica em se iniciar uso da insulina; no entanto, os resultados também revelam que os pacientes tendem a se acomodar com a via subcutânea uma vez iniciado o tratamento insulínico. Este estudo demonstra a importância que os pacientes com DM atribuem ao atributo controle glicêmico, e como suas preferências e DAP pelo tratamento insulínico variam entre as sub-populações. Especificamente, esforços devem ser realizados no sentido de vencer a barreira psicológica em se iniciar o uso da insulina, o que contribuirá para que se alcance um melhor controle glicêmico, através da melhor aderência do paciente ao tratamento, resultando em uma redução dos custos do DM e melhora na qualidade de vida dos pacientes.We used a discrete choice experiment (DCE) to evaluate patients preferences for various attributes of insulin treatment, including route of insulin delivery. Through a review of the literature, expert consultation, and a qualitative descriptive study using individual interviews and focus group techniques, the attributes (and levels) of diabetes treatment most important to patients were identified. The attributes included in the DCE were: glucose control, frequency of hypoglycaemic events, weight gain, route of administration for the long-acting and the short-acting insulin, and out-of-pocket cost. Patients with type 1 or type 2 diabetes were presented with pairs of hypothetical insulin therapy profiles (i.e. choice sets) with different levels of the attributes and were asked to choose the treatment option they preferred. Sociodemographic data and diabetes medication were also collected. Data were analysed using conditional logit regression and segmented models were also developed for the analysis of subgroups. A Two hundred and seventy four questionnaires were completed. The mean age (±SD) of participants was 56.7 ± 12.98 years, and 53% were men. Forty-nine percent of participants were insulin users, and 47 had type 1 diabetes. Overall, patients ideal insulin treatment would provide better glucose control, result in fewer adverse reactions, have the lowest cost, and be administered orally. There was a strong preference and highest mean WTP for glucose control followed by the risk attributes weight gain and hypoglycaemic events. Surprisingly, route of insulin administration was the least valued attribute. Stratification of the sample revealed that patients with higher incomes had a significant higher WTP for better glucose control and less adverse reactions compared to lower income groups. Moreover, the highest the income, the stronger the preference for an oral insulin, while inhaled insulin becomes less important for patients. Segmented models by insulin use and type of diabetes indicated that insulin naïve and type 2 diabetics had a greater aversion to the subcutaneous route. These findings suggest that there may be an important mental barrier to initiating insulin therapy; however, patients tend to accommodate to subcutaneous administration once they initiate therapy. This study illustrates the importance that patients with diabetes place on glucose control and how preferences for insulin therapy vary between subgroups. Specifically, efforts need to be made to overcome the mental barrier to initiating insulin therapy, which may lead to improved control, through improved compliance and ultimately reduce the financial burden of the disease and improve patients quality of life.
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Mamun, M. A. A. "An application of stated choice to the valuation of bus attributes : a case study of Dhaka, Bangladesh." Thesis, Loughborough University, 2014. https://dspace.lboro.ac.uk/2134/16198.
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Bus is the main mode of urban transport in most cities in developing countries. Despite a high mode share, bus service quality is often poor and para-transit services are regarded as a problem in urban transport systems rather than a solution. Using Dhaka as a case study, this thesis investigates bus service quality through identification and valuation of thirteen important attributes using discrete choice models. The attributes examined are travel time, travel cost, waiting time, headway, priority seats for women, crowding inside the bus, boarding and alighting, picking up and dropping off passengers, bus stop facilities, driving quality, driver and crew behaviour, cleanliness inside the bus, and air conditioning. Five focus groups were conducted to identify key qualitative bus attributes and their levels in order to design choice experiments for valuation. A survey of 431 respondents in Dhaka was then undertaken. Two choice experiments were designed and implemented within the survey, each with seven attributes (set A and set B) with travel cost as the common attribute. Multinomial Logit (MNL) models and Mixed Logit (MXL) models were developed using the Dhaka choice data. Twelve of the thirteen attributes were statistically significant at the 99% level. The values of in-vehicle time (IVT), waiting time and headway were BDT 34.80, 47.40 and 64.20 per hour respectively for low income groups in the segmented model. Waiting time has a premium valuation, 1.36 times higher than IVT, which endorses existing evidence. The highest valuation is for the dummy variable seating all the way which is BDT 42.20 for high income females. The next largest was bus stops properly, picks and drops passengers nicely , followed by wide door and mild steps for boarding and alighting , smooth and safe journey , bus stop with shed, but no seating arrangements , and air conditioning . The lowest value was BDT 4.61 for deck and seats are clean and tidy , for the low income group. The WTP for the qualitative attributes is high, but given the poor level of the existing service and low fare levels this seems reasonable. Income has a significant impact on travel cost, as well as gender on priority seats for women and crowding inside the bus. However, household car ownership does not have a significant impact on any of the bus attributes examined. The high income group has 75% higher WTP for A set attributes and 79% higher WTP for B set attributes than low income group. Females have 76% higher WTP for standing comfortably all the way , but 38% higher WTP for seating all the way compared to the male. However, females have a WTP of BDT 0.44 for per percent of priority seats for women in contrast with males who have a WTP of BDT -0.11. There is significant taste heterogeneity for both quantitative and qualitative attributes. The qualitative attributes for picking up and dropping off passengers, boarding and alighting facilities and driving facilities have higher valuation and this attributes came from the existing within the market competition structure in a highly fragmented bus market. Therefore, it is recommended to introduce competition for the market and incentives for bus industry consolidation.
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Sagebiel, Julian. "Valuing improvements in electricity supply using discrete choice experiments." Doctoral thesis, Humboldt-Universität zu Berlin, Lebenswissenschaftliche Fakultät, 2017. http://dx.doi.org/10.18452/17754.
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Um Strommärkte so zu konzipieren damit sie sowohl zur Verringerung der Nutzung fossiler Brennstoffe als auch zur Deckung des steigenden Energiebedarfes beitragen, ist Wissen über die Präferenzen der Konsumenten notwendig. Die vorliegende kumulative Dissertation untersucht Präferenzen für Elektrizitätsattribute von privaten Haushalten und trägt zu einem tieferen Verständnis dieser in unterschiedlichen Kontextsituationen bei. Der erste Artikel betrachtet statistische Methoden um die zwei am häufigsten angewandten Modelle – das Random Parameter Logit und das Latent Class Logit Modell – zu vergleichen. Der Artikel trägt dazu bei, den Prozess der Modellwahl zu verbessern und für die angewandte Forschung im Energiebereich anzupassen. Basierend auf den empirischen Ergebnissen des ersten Artikels untersucht der zweite Artikel die Präferenzen von privaten Haushalten in Hyderabad, Indien mit besonderem Fokus auf die physische Qualität der Energieversorgung. Die Ergebnisse deuten auf eine geringe Zahlungsbereitschaft der Konsumenten hin. Jedoch unterscheiden sich die Präferenzen der Haushalte. Die Artikel 3 und 4 basieren auf Datenerhebungen in Deutschland. Im dritten Artikel werden die Präferenzen privater Haushalte hinsichtlich der Organisationsform von Stromanbietern untersucht. Die Ergebnisse zeigen, dass die Kunden bereit sind mehr zu zahlen, wenn die Stromversorgung von Genossenschaften oder Stadtwerken übernommen wird. Der vierte Artikel betrachtet die Erfolgsfaktoren von Energiegenossenschaften in Deutschland. Die Ergebnisse zeigen, dass die Governance des Stromanbieters die Zahlungsbereitschaft für Strom beeinflussen. Insbesondere Genossenschaften werden den großen Privatunternehmen und Aktiengesellschaften vorgezogen.In order to design electricity markets to simultaneously reduce the share of fossil fuels in energy production and meet the increasing demand for electricity, knowledge on consumer preferences is necessary. The goal of this cumulative dissertation is to contribute to the understanding of preferences of private households for electricity supply attributes in different contexts. In Paper 1 I review statistical methods to compare two frequently applied models, the random parameters logit and the latent class logit. The methods presented here can be readily used by other researchers and practitioners to better understand model performance which ultimately contributes to improving model choice in applied energy research. Based on the empirical findings of Paper 1, Paper 2 identifies preferences of private households in Hyderabad in India for electricity supply quality. The results indicate that willingness to pay for improvements are, on average, rather low. However, the preferences strongly vary between subjects. Papers 3 and 4 investigate preferences of German private households. In \textbf{Paper 3}, the respondents stated their preferences for the organization of the electricity distribution company under different renewable energy scenarios. It turned out that most people are willing to pay more for electricity supplied by municipally-owned companies and cooperatives. This additional willingness to pay increases disproportionally when the share of renewable energy is high. The paper identifies non-profit orientated distribution companies as potential drivers of the energy transition. Paper 4 investigates the determinants for the success of energy cooperatives in Germany. The results indicate that the governance of distribution companies impacts the choices of private households for electricity supply contracts. Especially, people preferred cooperative-like governance attributes.
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Helveston, John Paul. "Development and Adoption of Plug-in Electric Vehicles in China: Markets, Policy, and Innovation." Research Showcase @ CMU, 2016. http://repository.cmu.edu/dissertations/855.
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(7659032), Zachary Brooks Smith. "DIGITAL TWIN: FACTORY DISCRETE EVENT SIMULATION." 2019.
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Industrial revolutions bring dynamic change to industry through major technological advances (Freeman & Louca, 2002). People and companies must take advantage of industrial revolutions in order to reap its benefits (Bruland & Smith, 2013). Currently, the 4th industrial revolution, industry is transforming advanced manufacturing and engineering capabilities through digital transformation. Company X’s production system was investigated in the research. Detailed evaluation the production process revealed bottlenecks and inefficiency (Melton, 2005). Using the Digital Twin and Discrete Event Factory Simulation, the researcher gathered factory and production input data to simulate the process and provide a system level, holistic view of Company X’s production system to show how factory simulation enables process improvement. The National Academy of Engineering supports Discrete Event Factory Simulation as advancing Personalized Learning through its ability to meet the unique problem solving needs of engineering and manufacturing process through advanced simulation technology (National Academy of Engineering, 2018). The directed project applied two process optimization experiments to the production system through the simulation tool, 3DExperience wiht the DELMIA application from Dassualt Systemes (Dassault, 2018). The experiment resulted in a 10% improvement in production time and a 10% reduction in labor costs due to the optimization
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Nepomuceno, Ana Rita Polainas. "Valorização dos atributos de um hotel citadino pelas gerações Millennial e Z: Uma abordagem através do modelo de escolha discreta." Master's thesis, 2021. http://hdl.handle.net/10071/24278.
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O setor do turismo apresenta uma importância crescente para as economias nacionais e, num
contexto de crescente competição, revela-se importante para os agentes do setor hoteleiro
compreender quais os fatores que tornam os hotéis mais atrativos. Contudo, são poucos os
estudos que procuraram quantificar monetariamente os atributos dos hotéis.
De forma a colmatar esta carência, o presente estudo aplicou o Modelo de Escolha Discreta
(MED), focando-se em hotéis citadinos de modo a (i) identificar os atributos mais valorizados
pelas gerações Millennial e Z, quantificando-os monetariamente; (ii) explorar as diferenças na
valorização dos atributos pelas referidas gerações; e (iii) investigar a relevância das ações
sustentáveis para as duas gerações.
Os resultados demonstraram que todos os atributos utilizados afetam significativamente a
escolha de um hotel citadino por parte das gerações Millennial e Z. Em particular, as ações
sustentáveis são valorizadas positivamente por ambas as gerações, mas principalmente pela
geração Z. As duas gerações distinguem-se também pelo valor que atribuem à proximidade de
um hotel face a transportes públicos, sendo este atributo apenas valorizado pela geração
Millennial.
Conhecer as preferências destas gerações e a sua disponibilidade em pagar pelos diferentes
atributos é determinante para a criação de estratégias de marketing direcionadas a este público-
alvo, permitindo aos hotéis obter uma vantagem competitiva. Para além de contribuir para a
escassa literatura que aplica o MED no contexto da hotelaria, este estudo distingue-se ainda
pelo seu foco nas gerações Millennial e Z e pela introdução de um atributo relacionado com
ações sustentáveis.The tourism sector is increasingly important for national economies and in a context of growing competition, it is important for hospitality managers to understand which aspects make hotels more attractive to consumers. However, few studies have investigated the monetary value of hotel attributes. In order to fill this research gap, the present study used the Discrete Choice Experiment (DCE) methodology to: (i) identify and quantify monetarily the attributes of an urban hotel that are most valued by Millennials and Gen Zers; (ii) explore differences in the valuation of attributes by each generation; (iii) investigate the importance of sustainable actions in the hotel sector for these generations. The results suggest that all the attributes investigated significantly affect the choice of urban hotels by the Millennial and Z generations. In particular, sustainable actions are positively valued by both generations, but mainly by Gen Zers. Both generations can also be distinguished by the value that they attribute to the proximity of a hotel to public transportation, with this attribute being only valued by Millennials. Knowing the preferences of these generations and their willingness to pay for hotel attributes is essential for the design of marketing strategies targeting them, allowing hotels to gain a competitive advantage.Besides adding to the lack of scientific literature that applies the DCE in hospitality, this study also adds value due to its focus on Millennial and Z generations and for the introduction of an attribute related to sustainability.
Books on the topic "Discrete ply model"
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McAdams, Stephen, and Bruno L. Giordano. The perception of musical timbre. Edited by Susan Hallam, Ian Cross, and Michael Thaut. Oxford University Press, 2012. http://dx.doi.org/10.1093/oxfordhb/9780199298457.013.0007.
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This article discusses musical-timbre perception. Musical timbre is a combination of continuous perceptual dimensions and discrete features to which listeners are differentially sensitive. The continuous dimensions often have quantifiable acoustic correlates. The timbre-space representation is a powerful psychological model that allows predictions to be made about timbre perception in situations beyond those used to derive the model in the first place. Timbre can play a role in larger-scale movements of tension and relaxation and thus contribute to the expression inherent in musical form. Under conditions of high blend among instruments composing a vertical sonority, timbral roughness is a major component of musical tension. However, it strongly depends on the way auditory grouping processes have parsed the incoming acoustic information into events and streams.
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Menon, Vinod. Arithmetic in the Child and Adult Brain. Edited by Roi Cohen Kadosh and Ann Dowker. Oxford University Press, 2014. http://dx.doi.org/10.1093/oxfordhb/9780199642342.013.041.
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This review examines brain and cognitive processes involved in arithmetic. I take a distinctly developmental perspective because neither the cognitive nor the brain processes involved in arithmetic can be adequately understood outside the framework of how developmental processes unfold. I review four basic neurocognitive processes involved in arithmetic, highlighting (1) the role of core dorsal parietal and ventral temporal-occipital cortex systems that form basic building blocks from which number form and quantity representations are constructed in the brain; (2) procedural and working memory systems anchored in the basal ganglia and frontoparietal circuits, which create short-term representations that allow manipulation of multiple discrete quantities over several seconds; (3) episodic and semantic memory systems anchored in the medial and lateral temporal cortex that play an important role in long-term memory formation and generalization beyond individual problem attributes; and (4) prefrontal cortex control processes that guide allocation of attention resources and retrieval of facts from memory in the service of goal-directed problem solving. Next I examine arithmetic in the developing brain, first focusing on studies comparing arithmetic in children and adults, and then on studies examining development in children during critical stages of skill acquisition. I highlight neurodevelopmental models that go beyond parietal cortex regions involved in number processing, and demonstrate that brain systems and circuits in the developing child brain are clearly not the same as those seen in more mature adult brains sculpted by years of learning. The implications of these findings for a more comprehensive view of the neural basis of arithmetic in both children and adults are discussed.
Book chapters on the topic "Discrete ply model"
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Mader, Angelika. "A Classification of PLC Models and Applications." In Discrete Event Systems, 239–46. Boston, MA: Springer US, 2000. http://dx.doi.org/10.1007/978-1-4615-4493-7_24.
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Treseler, Heinz, Nanette Bauer, and Stefan Kowalewski. "Verification of IL Programs with an Explicit Model of their PLC Execution." In Discrete Event Systems, 283–90. Boston, MA: Springer US, 2000. http://dx.doi.org/10.1007/978-1-4615-4493-7_29.
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Mariel, Petr, David Hoyos, Jürgen Meyerhoff, Mikolaj Czajkowski, Thijs Dekker, Klaus Glenk, Jette Bredahl Jacobsen, et al. "Econometric Modelling: Extensions." In Environmental Valuation with Discrete Choice Experiments, 83–101. Cham: Springer International Publishing, 2020. http://dx.doi.org/10.1007/978-3-030-62669-3_6.
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AbstractThis chapter is devoted to advanced issues of econometric modelling. The topics covered are, among others, models in willingness to pay space, the meaning of scale heterogeneity in discrete choice models and the application of various information processing rules such as random regret minimisation or attribute non-attendance. Other topics are anchoring and learning effects when respondents move through a sequence of choice tasks as well as different information processing strategies such as lexicographic preferences or choices based on elimination-by-aspects.
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Mariel, Petr, David Hoyos, Jürgen Meyerhoff, Mikolaj Czajkowski, Thijs Dekker, Klaus Glenk, Jette Bredahl Jacobsen, et al. "Theoretical Background." In Environmental Valuation with Discrete Choice Experiments, 1–6. Cham: Springer International Publishing, 2020. http://dx.doi.org/10.1007/978-3-030-62669-3_1.
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AbstractThis chapter starts by briefly presenting the theoretical background of welfare economics and introducing key aspects such as the indirect utility function, the expenditure function, or the concepts of compensating surplus or equivalent surplus. Next, it draws attention to willingness to pay and willingness to accept, essential measures in environmental valuation. Finally, the chapter summarises the basic mathematical notation of the random utility maximisation models used throughout the book.
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Salinas Ruíz, Josafhat, Osval Antonio Montesinos López, Gabriela Hernández Ramírez, and Jose Crossa Hiriart. "Generalized Linear Mixed Models for Proportions and Percentages." In Generalized Linear Mixed Models with Applications in Agriculture and Biology, 209–78. Cham: Springer International Publishing, 2023. http://dx.doi.org/10.1007/978-3-031-32800-8_6.
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AbstractIn this chapter, we will review generalized linear mixed models (GLMMs) whose response can be either a proportion or a percentage. For proportion and percentage data, we refer to data whose expected value is between 0 and 1 or between 0 and 100. For the remainder of this book, we will refer to this type of data only in terms of proportion, knowing that it is possible to change it to a percentage scale only when multiplying it by 100. Proportions can be classified into two types: discrete and continuous. Discrete proportions arise when the unit of observation consists of N distinct entities, of which individuals have the attribute of interest “y. ”N must be a nonnegative integer and “y” must be a positive integer; here, y ≤ N. Therefore, the observed proportion must be a discrete fraction, which can take values $$ \frac{0}{N},\frac{1}{N},\cdots, \frac{N}{N} $$ 0 N , 1 N , ⋯ , N N . A binomial distribution is the sum of a series of m independent binary trials (i.e., trials with only two possible outcomes: success or failure), where all trials have the same probability of success. For binary and binomial distributions, the target of inference is the value of the parameter such that $$ 0\le E\left(\frac{y}{N}\right)=\pi \le 1 $$ 0 ≤ E y N = π ≤ 1 . Continuous proportions (ratios) arise when the researcher measures responses such as the fraction of the area of a leaf infested with a fungus, the proportion of damaged cloth in a square meter, the fraction of a contaminated area, and so on. As with the binomial parameter π, the continuous rates (fractions) take values between 0 and 1, but, unlike the binomial, the continuous proportions do not result from a set of Bernoulli tests. Instead, the beta distribution is most often used when the response variable is in continuous proportions. In the following sections, we will first address issues in modeling when we have binary and binomial data. When the response variable is binomial, we have the option of using a linearization method (pseudo-likelihood (PL)) or the Laplace or quadrature integral approximation (Stroup 2012).
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Gössinger, Ralf, and Jacqueline Wand. "Capacitated Price Bundling for Markets with Discrete Customer Segments and Stochastic Willingness to Pay: ABasic Decision Model." In Operations Research Proceedings, 617–23. Cham: Springer International Publishing, 2020. http://dx.doi.org/10.1007/978-3-030-48439-2_75.
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Harris, Randy Allen. "Generative Semantics 4: The Collapse." In The Linguistics Wars, 223–60. Oxford University Press, 2021. http://dx.doi.org/10.1093/oso/9780199740338.003.0007.
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This chapter traces the collapse of Generative Semantics, which ultimately became a movement away from Noam Chomsky’s view of linguistics, more than a movement toward a unifying vision of language or linguistics. The leaders all went in various directions. Paul Postal and Jim McCawley retained their commitments to formal modeling, but Postal developed a new, non-Transformational framework with David Perlmutter, Relational Grammar, while McCawley continued to ply an increasingly idiosyncratic Transformational model he eventually called Unsyntax. Robin Lakoff led the expansion of linguistic pragmatics and founded feminist linguistics. George Lakoff and Haj Ross took overlapping but distinct forays into non-discrete linguistics. Meanwhile, the Generative Semantics ethos was losing whatever appeal it may have had. Linguists outside the movement, and some within, found the style irritating. Meanwhile, too, Chomsky’s innovations were proving very fruitful and attracting adherents under the label, the Extended Standard Theory. Chomsky’s framework emerged from the brief Generative Semantics eclipse and now seemed the clear winner of the Linguistics Wars.
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Garrido, Rodrigo A. "Bayesian Reliability of Discrete Choice Models." In Travel Behaviour Research: Updating the State of Play, 425–33. Elsevier, 1998. http://dx.doi.org/10.1016/b978-008043360-8/50023-6.
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Milligan, Brook G. "Estimating evolutionary rates for discrete characters." In Models in Phylogeny Reconstruction, 299–312. Oxford University PressOxford, 1994. http://dx.doi.org/10.1093/oso/9780198548249.003.0016.
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Abstract Models play two roles in the study of evolutionary history. First, they are either explicitly or implicitly involved in the reconstruction of phylogenetic relationships. Second, they provide the means of testing alternative, biologically motivated evolutionary scenarios. Although there is widespread interest in both applications of evolutionary models, there are relatively few attempts to estimate them in a phylogenetic context. I present a general means of estimating such models specified in terms of the rate of transition between character states, and illustrate it with both molecular and morphological data. While relatively simple molecular models are easily rejected for the chloroplast gene rbcL, no compelling evidence exists for non-independent evolution of sexuality and propagule type among seed plants. These results are significant because they indicate that the models currently being used for phylogenetic reconstruction may be explicity tested and, in addition, specific evolutionary hypotheses may be investigated. This approach unifies phylogenetic inference with the comparative method.
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Morikawa, Takayuki, and Kuniaki Sasaki. "Discrete Choice Models with Latent Variables Using Subjective Data." In Travel Behaviour Research: Updating the State of Play, 435–55. Elsevier, 1998. http://dx.doi.org/10.1016/b978-008043360-8/50024-8.
Full textConference papers on the topic "Discrete ply model"
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Hamila, Nahiene, Philippe Boisse, and Sylvain Chatel. "Meso-Macro Simulations of Textile Composite Forming." In ASME 2008 International Manufacturing Science and Engineering Conference collocated with the 3rd JSME/ASME International Conference on Materials and Processing. ASMEDC, 2008. http://dx.doi.org/10.1115/msec_icmp2008-72382.
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Composite textile reinforcement draping simulations aid in determining the processing conditions for a quality part and in finding the positions of the fibers after forming. This last point is essential for the structural computations of the composite part and for resin injection analyses in the case of LCM processes. Because the textile composite reinforcements are multiscale materials, continuous (macro) approaches and discrete (meso) approaches that model the yarns have been developed. The finite element that is proposed in this paper for textile fabric forming is composed of woven unit cells. The mechanical behaviour of these is analyzed by 3D computations at the mesoscale. The warp and weft directions of the woven fabric can be in an arbitrary direction with respect to the direction of the element side. This is very important in the case of multi-ply deep drawing and when using remeshing. The element is efficient because it is close to the physics of the woven cell while avoiding the very large number of unknowns in the discrete approach. A set of validation tests and forming simulations on single-ply and multi-ply fabrics is presented and shows the efficiency of the approach.
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Nerurkar, Nandan L., Robert L. Mauck, and Dawn M. Elliott. "Modeling Inter-Lamellar Interactions in Angle-Ply Nanofibrous Biologic Laminates for Annulus Fibrosus Tissue Engineering." In ASME 2010 Summer Bioengineering Conference. American Society of Mechanical Engineers, 2010. http://dx.doi.org/10.1115/sbc2010-19479.
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Function of the annulus fibrosus (AF) of the intervertebral disc is predicated on a high degree of structural organization over multiple length scales. Recently, we have employed aligned electrospun scaffolds to engineer nanofibrous biologic laminates that replicate the form and function of the AF [1]. Further, we determined that interlamellar shearing — a direct consequence of the +/−30° angle-ply architecture — plays an important role in reinforcing the tensile response of these materials (Fig. 1). Although we have utilized fiber-reinforced continuum models to characterize the evolving mechanics of single-lamellar AF constructs with in vitro culture [2, 3], these models are not capable of capturing the interlamellar interactions observed in bi-lamellar constructs. Indeed, continuum models of the native AF typically do not account for the organization of fiber populations into discrete, alternating planes of alignment, and so these models, too, do not account for inter-lamellar shearing interactions [4–6]. Therefore, in the present work we propose a novel constitutive model for the reinforcing role of interlamellar shearing during uniaxial extension of angle-ply biologic laminates and employ this model to evaluate the functional evolution of bilayers for AF tissue engineering.
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. GOLDBERG, ROBERT K., and TRENTON M. RICKS. "DEVELOPMENT OF SIMPLIFIED METHODS TO CHARACTERIZE PLASTICITY PARAMETERS FOR LS-DYNA MAT213." In Proceedings for the American Society for Composites-Thirty Eighth Technical Conference. Destech Publications, Inc., 2023. http://dx.doi.org/10.12783/asc38/36550.
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A material model which incorporates several key capabilities which have been identified as lacking in currently available composite material models has been developed. The material model utilizes experimentally based tabulated input to define the evolution of plasticity, damage, and failure as opposed to specifying discrete input parameters (such as modulus and strength). It has been implemented into the commercially available transient dynamic finite element code LS-DYNA® as MAT 213. The model can simulate the nonlinear deformation, damage and failure that take place in a composite under dynamic loading conditions. One challenge that has been encountered by users of MAT 213 is that several of the parameters in the orthotropic plasticity model are extremely difficult to characterize experimentally or data may not be available to characterize them. To simplify this process, a toolset and methodology are being developed which can be implemented as a stand-alone in MATLAB® application. A key part of this toolset will utilize a simplified version of the orthotropic plasticity model. Specifically, the orthotropic plasticity model utilized in MAT 213 has been simplified to simulate the stress-strain response of a composite ply with an arbitrary fiber orientation subjected to uniaxial loading or the shear response of a composite ply subject to pure shear loading. These simplified models will allow a user to simultaneously simulate the longitudinal and transverse tensile and compressive stress-strain responses, the shear stress-shear strain responses, and the off-axis tensile (or compressive) stress-strain responses of a composite ply in a highly efficient manner. By using this toolset, particularly when combined with a suitable optimizer, a user can quickly determine the required plasticity model parameters required for a MAT 213 analysis.
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Arpacioglu, Bertan, and Altan Kayran. "Comparative Structural Optimization Study of Composite and Aluminum Horizontal Tail Plane of a Helicopter." In ASME 2019 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2019. http://dx.doi.org/10.1115/imece2019-11153.
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Abstract This work presents structural optimization studies of aluminum and composite material horizontal tail plane of a helicopter by using MSC. NASTRAN SOL200 optimization capabilities. Structural design process starts from conceptual design phase, and structural layout design is performed by using CATIA. In the preliminary design phase, study focuses on the minimum weight optimization with multiple design variables and similar constraints for both materials. Aerodynamic load calculation is performed using ANSYS and the finite element model of the horizontal tail plane is created by using MSC.PATRAN. According to the characteristics of materials, design variables are chosen. For the aluminum horizontal tail, thickness and flange areas are used as the design variables; and for composite horizontal tail, attention is mainly focused on the ply numbers and ply orientation angles of the laminated composite panels. By considering the manufacturability issues, discrete design variables are used. For three different mesh densities, different initial values of the design variables, and similar design constraints, optimizations are repeated and the results of optimizations are examined and compared with each other. In the optimizations performed, constraints are taken as strength and local buckling constraints. It is shown that the optimization methodology used in this study gives confident results for optimizing structures in the preliminary design phase.
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Atanasov, Atanas A., Thomas J. Wright, and John P. Parmigiani. "Improvement on the Analysis of a Finite Element Composites Model." In ASME 2013 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2013. http://dx.doi.org/10.1115/imece2013-63282.
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Finite element models are increasingly being utilized in composite materials design; thus, an increase in the accuracy of the model analysis and a decrease in computational cost are of paramount importance. This study investigates the effects of a particular add-on, Helius:MCT (Firehole Technologies, Inc.), onto the Abaqus (Dassault Systèmes) software package. Unlike the stand-alone Abaqus software, Helius:MCT embodies a solver, which analyzes the composite structure by separating the fiber and matrix into constituent parts. Treating the fiber and matrix as separate, yet linked entities, allows for a more accurate depiction of the formations of stress and strain within the composite. Furthermore, Helius:MCT utilizes a method called Intelligent Discrete Softening (IDS), a feature not present within Abaqus, to increase solver robustness and convergence probability. An Abaqus finite element (FE) model of a notched, carbon-fiber panel loaded in bending was used in this study. Six different laminate combinations were tested with six variations of the Abaqus model. Three of the variations used Helius:MCT with Abaqus and three the stand-alone Abaqus package. The combinations were composed of either 20 or 40 plies with 10, 30, or 50 percent all zero ply orientations. All the FE analysis results were compared to experimental values for a plate of the exact configuration as that of the model. The most accurate results were obtained using Helius:MCT. The configuration with the greatest accuracy utilizes Helius:MCT and deviates an average of 1.7 percent from experimental values for maximum flexural strength. A single run takes an average of 7 hours to complete. Conversely, the most accurate configuration obtained without the use of Helius:MCT deviates an average of 10 percent from the experimental values and takes over 80 hours to run. Helius: MCT increases the accuracy and decreases the computational costs of the analyses of composite models in Abaqus. The improvements in analyses while using Helius: MCT may allow for a substantial savings in experimental costs and in valuable time.
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ESKANDARIYUN, AMIRALI, HUILONG FU, JOHANNES REINER, REZA VAZIRI, and NAVID ZOBEIRY. "EXPLORING UNDERLYING CORRELATIONS IN MULTI-FIDELITY FINITE ELEMENT SIMULATIONS OF OPEN-HOLE TENSION TESTS: A COMPARATIVE STUDY USING MACHINE LEARNING." In Proceedings for the American Society for Composites-Thirty Eighth Technical Conference. Destech Publications, Inc., 2023. http://dx.doi.org/10.12783/asc38/36670.
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generate another database of simulation results. Both databases were used to create a training set for an ML model, aiming to study the correlation between low- and high-fidelity inputs that result in similar failure responses. The results enable increasing use of low-fidelity FE models to generate data for the training of ML models.Certification of composite aerostructures is typically achieved via analysis supported by testing, following the building block approach. Analysis of failure and crash at different scales, as well as design iterations and optimization, require fast and validated numerical models. Given the complexity and interactions of multi-failure mechanisms in composites, high-fidelity FE models are often needed to explicitly simulate the behavior of individual layers and their interlaminar interfaces, using a mix of continuum and discrete damage models. However, high-fidelity FE models require a considerable amount of time to set up, calibrate, and perform. On the other hand, low-fidelity modeling approaches, such as laminate-based smeared models, may provide reduced accuracy in some cases, while offering shorter simulation times and thereby lower computational costs. In this study, progressive failure of Open-Hole Tension (OHT) tests on HEXCEL IM-7/8552 quasi-isotropic laminates are investigated using both low- and high-fidelity FE models. A Machine Learning (ML) technique is then employed to perform a comparative study between the inputs and outputs of these models. The ultimate goal is to identify areas in the FE parameter space where the low-fidelity model can be used as a substitute for the high-fidelity model with reasonable accuracy and to discover the relationships among main parameters to reproduce high-fidelity results from the low-fidelity model in an accelerated manner. To generate the low-fidelity model, a laminate-based FE model was created in LS-DYNA, using a continuum elastoplastic damage-based material card, MAT081. The model parameters were varied randomly, and simulations were performed to generate a large database of low-fidelity FE results. Similarly, a ply-based FE model employing MAT261 for continuum intralaminar damage modeling combined with cohesive tiebreak contacts to capture discrete interlaminar delamination was created. This high-fidelity model was also used to
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Ferrero, Laura, and Ugo Icardi. "Optimization of Multi-Core Sandwich Composites Undergoing Impact Loads." In ASME 2007 International Mechanical Engineering Congress and Exposition. ASMEDC, 2007. http://dx.doi.org/10.1115/imece2007-42851.
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In this paper, multiple cores sandwich composites undergoing impact loads are optimized in order to improve their resistance to the impact-induced delamination. This peculiar type of composites is characterized by one internal face splitting the core in two parts. Owing to their architecture with an intermediate and two external faces, their additional tailoring capability offers potential advantages in terms of energy absorption capability and damage tolerance behavior over conventional sandwich composites. Obviously, an accurate assessment of the interfacial stress fields, of their damage accumulation mechanisms and of their post-failure behavior are fundamental to fully exploit their potential advantages. Despite it is evident that structural models able to accurately describe the local behavior are needed to accomplish this task, the analysis is commonly still carried out using simplified sandwich models which postulate the overall variation of displacements and stresses across the thickness, because more detailed models could make the computational effort prohibitively large. No attempt is here made to review the ample literature about the sandwich composite models, since a plenty of comprehensive bibliographical review papers and monographs are available in the specialized literature. Likewise, no attempt is made for reviewing the methods used to model the damage. It is just remarked that the models to date available range from detailed models which discretize the real structure of the core, to FEM models by brick elements, to discrete-layer models and to sublaminate models. In these paper, two different models are used, to achieve a compromise between accuracy and limitation of costs. The time history of the contact force is computed by a C° eight-node plate element based on a 3D zig-zag model, in order to achieve the best accuracy using a plate model with the customary five functional d.o.f. This model is also used in the optimization process, since it is mathematically easily treatable and accurately describes the strain energy. In addition, it enables a comparison with the classical plate models, since they can be particularized from it. The counterpart plate element of this zig-zag model, which is obtained from a standard C° plate element through a strain energy updating (which successfully described the impact induced damage as shown by the comparison with the damage detected by c-scanning in a previous paper), is used for computing the contact force time history, to reach a good compromise between accuracy and computational costs. A mixed brick element with the three displacements and the three interlaminar stresses as nodal d.o.f. is used to compute the damage at each time step. The onset of damage is predicted in terms of matrix and fibers failure, cracks, delamination, rippling, wrinkling and face damping using different stress-based criteria. In this paper the effects of the accumulated damage are accounted for through the ply-discount theory, i.e. using reduced elastic properties for the layers and the cores that failed, although it is known that some cases exist for which this material degradation model could be unable to describe the real loss of load carrying capacity. The optimization technique recently proposed by the authors is used in this paper for optimizing the energy absorption properties of multi-core sandwiches undergoing impact loads. The effect of this technique is to act as an energy absorption tuning, since it minimizes or maximizes the amount of energy absorbed by specific modes through a suited in-plane variation of the plate stiffness properties (e.g., bending, in-plane and out-of-plane shears and membrane energies). The appropriate in-plane variable distributions of stiffness properties, making certain strain energy contributions of interest extremal, are found solving the Euler-Lagrange equations resulting from assumption of the laminate stiffness properties as the master field and setting to zero the first variation of wanted and unwanted strain energy contributions (e.g., bending, in-plane and out-of-plane shears and membrane energies). Our purpose is to minimize the energy absorbed through unwanted modes (i.e., involving interlaminar strengths) and maximize that absorbed through desired modes (i.e., involving membrane strengths). The final result is a ply with variable stiffness coefficient over its plane which is able to consistently reduce the through-the-thickness interlaminar stress concentrations, with beneficial effects on the delamination strength. All the solutions proposed can be obtained either varying the orientation of the reinforcement fibers, the fiber volume rate or the constituent materials by currently available manufacturing processes. The coefficients of the involved stiffness terms are computed enforcing conditions which range from the thermodynamic constraints, to imposition of the mean stiffness, to the choice of a convex or a concave shape (in order to minimize or maximize the energy contributions of interest). Two solutions of technical interest will be proposed, which both are based on a parabolic distribution of stiffness coefficients. The former reduces the bending of a lamina with moderately increasing the shear stresses, the second one reduces these stresses with a low increment in the bending contribution. The effects of the incorporation of these layers (with the same mean properties of the layers they replace) is shown hereafter.
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El-Khazali, Reyad, Shaher Momani, and Iqbal Batiha. "A New Discrete-Time Model of Fractional-Order PLL." In 2020 3rd International Conference on Signal Processing and Information Security (ICSPIS). IEEE, 2020. http://dx.doi.org/10.1109/icspis51252.2020.9340137.
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Dogaru, Elvis, Flaviu Mihai Frigura-Iliasa, Mirela Iorga, Lia Dolga, Hannelore Filipescu, and Mihaela Frigura-Iliasa. "PLC Commanded Intelligent Logistics Model Based on Discrete Event Systems." In 2019 4th International Conference on Intelligent Transportation Engineering (ICITE). IEEE, 2019. http://dx.doi.org/10.1109/icite.2019.8880159.
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Vieira, Agnelo Denis, Jose Eduardo Ribeiro Cury, and Max Hering de Queiroz. "A Model for PLC Implementation of Supervisory Control of Discrete Event Systems." In 2006 IEEE Conference on Emerging Technologies and Factory Automation. IEEE, 2006. http://dx.doi.org/10.1109/etfa.2006.355436.
Full textReports on the topic "Discrete ply model"
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Rigby, Dan, Michael Burton, Katherine Payne, Zachary Payne-Thompson, Stuart Wright, and Sarah O’Brien. Impacts of Food Hypersensitivities on Quality of Life in the UK and Willingness to Pay (WTP) to remove those impacts. Food Standards Agency, December 2022. http://dx.doi.org/10.46756/sci.fsa.kij502.
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This project concerns the impacts of food hypersensitivity on people’s quality of life and the monetary value people assign to the removal of those impacts. Food hypersensitivities (FHS) are, in this report, defined as comprising food allergy, coeliac disease and food intolerance. Estimates of the economic value of removal of food hypersensitivity were generated from a stated preference (SP) survey in which people completed a discrete choice experiment (DCE). The DCE comprised of choices between (i) no change in respondents’ food hypersensitivity and (ii) the condition being removed for a specified period, at a cost. The surveys were conducted between July and December 2021 by adults regarding their own food hypersensitivity or by parents/carers regarding their child’s food hypersensitivity. The samples comprised 1426 adults and 716 parents. The average WTP for the removal of an adult’s FHS for a year, pooled across all conditions was £718. For models estimated separately by condition, the WTP values for food allergy, coeliac disease and food intolerance were £1064, £1342 and £540 respectively. In models estimated on DCE data from parents regarding their children’s food hypersensitivity the average WTP, pooled across all conditions, was £2501. The annual WTP values by condition were: £2766 for food allergy; £1628 for coeliac disease; £1689 for food intolerance. Respondents rated their (child’s) health and the impacts of their (child’s) FHS using several established instruments including the Food Allergy Quality of Life Questionnaire (FAQLQ); Food Intolerance Quality of Life Questionnaire (FIQLQ); Coeliac Disease Quality of Life Questionnaire, (CDQ). In the adult allergy and intolerance models we find robust evidence of effects of the perceived severity of FHS on WTP – the higher people’s FAQLQ and FIQLQ scores, the more they are willing to pay to remove their condition. There was no effect of variation in the CDQ score on WTP to remove coeliac disease. In the child WTP results we find condition-severity effects in the coeliac sample: the worse the child’s CDQ score the higher the parents’ WTP to remove the condition. The WTP values are estimates of the combined annual costs associated with (i) the intangible costs including the pain, anxiety, inconvenience and anxiety caused by FHS and (ii) additional incurred costs (time and money) and lost earnings. The values can be incorporated into the FSA Cost of Illness (COI) model, the Burden of Foodborne disease in the UK (Opens in a new window) which is currently used to measure the annual, social, cost of foodborne disease. A Best Worst Scaling (BWS) exercise was conducted to identify the relative importance of the many and diverse impacts which comprise the FAQLQ, FIQLQ and CDQ instruments. The BWS results indicate that people assign very different levels of importance to the impacts comprising the three instruments. This unequal prioritisation contrasts with the equal weighting used in the construction of the FAQLQ, FIQLQ and CDQ measures. Embarrassment and fear related to eating out or social situations feature in the top three impacts for all the conditions. Identifying the effects which most affect quality of life (from the perspective of people living with those conditions) has the potential to inform policy and practice by both regulators and private organisations such as food business operators.
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Wozniakowska, P., D. W. Eaton, C. Deblonde, A. Mort, and O. H. Ardakani. Identification of regional structural corridors in the Montney play using trend surface analysis combined with geophysical imaging, British Columbia and Alberta. Natural Resources Canada/CMSS/Information Management, 2021. http://dx.doi.org/10.4095/328850.
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The Western Canada Sedimentary Basin (WCSB) is a mature oil and gas basin with an extraordinary endowment of publicly accessible data. It contains structural elements of varying age, expressed as folding, faulting, and fracturing, which provide a record of tectonic activity during basin evolution. Knowledge of the structural architecture of the basin is crucial to understand its tectonic evolution; it also provides essential input for a range of geoscientific studies, including hydrogeology, geomechanics, and seismic risk analysis. This study focuses on an area defined by the subsurface extent of the Triassic Montney Formation, a region of the WCSB straddling the border between Alberta and British Columbia, and covering an area of approximately 130,000 km2. In terms of regional structural elements, this area is roughly bisected by the east-west trending Dawson Creek Graben Complex (DCGC), which initially formed in the Late Carboniferous, and is bordered to the southwest by the Late Cretaceous - Paleocene Rocky Mountain thrust and fold belt (TFB). The structural geology of this region has been extensively studied, but structural elements compiled from previous studies exhibit inconsistencies arising from distinct subregions of investigation in previous studies, differences in the interpreted locations of faults, and inconsistent terminology. Moreover, in cases where faults are mapped based on unpublished proprietary data, many existing interpretations suffer from a lack of reproducibility. In this study, publicly accessible data - formation tops derived from well logs, LITHOPROBE seismic profiles and regional potential-field grids, are used to delineate regional structural elements. Where seismic profiles cross key structural features, these features are generally expressed as multi-stranded or en echelon faults and structurally-linked folds, rather than discrete faults. Furthermore, even in areas of relatively tight well control, individual fault structures cannot be discerned in a robust manner, because the spatial sampling is insufficient to resolve fault strands. We have therefore adopted a structural-corridor approach, where structural corridors are defined as laterally continuous trends, identified using geological trend surface analysis supported by geophysical data, that contain co-genetic faults and folds. Such structural trends have been documented in laboratory models of basement-involved faults and some types of structural corridors have been described as flower structures. The distinction between discrete faults and structural corridors is particularly important for induced seismicity risk analysis, as the hazard posed by a single large structure differs from the hazard presented by a corridor of smaller pre-existing faults. We have implemented a workflow that uses trend surface analysis based on formation tops, with extensive quality control, combined with validation using available geophysical data. Seven formations are considered, from the Late Cretaceous Basal Fish Scale Zone (BFSZ) to the Wabamun Group. This approach helped to resolve the problem of limited spatial extent of available seismic data and provided a broader spatial coverage, enabling the investigation of structural trends throughout the entirety of the Montney play. In total, we identified 34 major structural corridors and number of smaller-scale structures, for which a GIS shapefile is included as a digital supplement to facilitate use of these features in other studies. Our study also outlines two buried regional foreland lobes of the Rocky Mountain TFB, both north and south of the DCGC.