scholarly journals Mechanical analysis of heterogeneous materials with higher-order parameters

2021 ◽  
Author(s):  
Bozo Vazic ◽  
Bilen Emek Abali ◽  
Hua Yang ◽  
Pania Newell
Keyword(s):  
Mechanical Properties ◽  
Porous Materials ◽  
Higher Order ◽  
Order Parameters ◽  
Constitutive Law ◽  
Porous System ◽  
First Order ◽  
Bio Engineering ◽  
The Relationship ◽  
Effective Mechanical Properties

AbstractEven though heterogeneous porous materials are widely used in a variety of engineering and scientific fields, such as aerospace, energy-storage technology, and bio-engineering, the relationship between effective material properties of porous materials and their underlying morphology is still not fully understood. To contribute to this knowledge gap, this paper adopts a higher-order asymptotic homogenization method to numerically investigate the effect of complex micropore morphology on the effective mechanical properties of a porous system. Specifically, we use the second-order scheme that is an extension of the first-order computational homogenization framework, where a generalized continuum enables us to introduce length scale into the material constitutive law and capture both pore size and pore distribution. Through several numerical case studies with different combinations of porosity, pore shapes, and distributions, we systematically studied the relationship between the underlying morphology and effective mechanical properties. The results highlight the necessity of higher-order homogenization in understanding the mechanical properties and reveal that higher-order parameters are required to capture the role of realistic pore morphologies on effective mechanical properties. Furthermore, for specific pore shapes, higher-order parameters exhibit dominant influence over the first-order continuum.

scholarly journals Solution of Higher-Order ODEs Using Backward Difference Method

2011 ◽  
Vol 2011 ◽  
pp. 1-18 ◽  
Author(s):  
Mohamed Bin Suleiman ◽  
Zarina Bibi Binti Ibrahim ◽  
Ahmad Fadly Nurullah Bin Rasedee
Keyword(s):  
Differential Equations ◽  
Ordinary Differential Equations ◽  
Difference Method ◽  
Numerical Technique ◽  
Higher Order ◽  
First Order ◽  
The Relationship

The current numerical technique for solving a system of higher-order ordinary differential equations (ODEs) is to reduce it to a system of first-order equations then solving it using first-order ODE methods. Here, we propose a method to solve higher-order ODEs directly. The formulae will be derived in terms of backward difference in a constant stepsize formulation. The method developed will be validated by solving some higher-order ODEs directly with constant stepsize. To simplify the evaluations of the integration coefficients, we find the relationship between various orders. The result presented confirmed our hypothesis.

scholarly journals Suspension, Higher-Order Evidence, and Defeat

2021 ◽  
pp. 116-145
Author(s):  
Errol Lord ◽  
Kurt Sylvan
Keyword(s):  
Higher Order ◽  
Functional Profile ◽  
Reasons For Belief ◽  
Epistemic Akrasia ◽  
First Order ◽  
Evidential Support ◽  
Support Relations ◽  
The Relationship ◽  
Suspension Of Judgment ◽  
Higher Order Evidence

This paper has two main goals. The first and most central goal is to develop a framework for understanding higher-order defeat. The framework rests on the idea that higher-order evidence provides direct reasons for suspending judgment which leave evidential support relations on the first order intact. Equally importantly, we also seek to explain how this sort of defeat is possible by showing how direct reasons for suspension of judgment flow from the functional profile of suspension of judgment. As a result, our framework is embedded within an account of the nature of suspension of judgment that shows how new insights about its nature lead to a different picture of its rational profile. A second and subsidiary goal of the paper is to show how our framework provides a compelling basis for more moderate positions about disagreement and epistemic akrasia. We show that the puzzles about these topics rest on more fundamental mistakes about suspension and the relationship between reasons for suspension, reasons for belief, and evidence.

Analysis of Effective Mechanical Properties and Anisotropy of Structured Porous Materials

2014 ◽  
Author(s):  
Efrain De la Rosa Dávila ◽  
Dirk F. de Lange ◽  
Hugo I. Medellín Castillo ◽  
Gilberto Mejía Rodríguez
Keyword(s):  
Mechanical Properties ◽  
Pore Structure ◽  
Porous Materials ◽  
Porous Structures ◽  
Binary Function ◽  
Fem Model ◽  
Anisotropic Properties ◽  
Practical Applications ◽  
Proper Design ◽  
Effective Mechanical Properties

Many natural and modern man-made materials are porous materials. In many cases, for practical applications and for the proper design of products it is necessary to understand the effective mechanical properties of the porous structure. Even though some general applicable theories exist to estimate the mechanical properties in function of the porosity fraction, or apparent density, the relation between the pore structure and size distribution is not clear. In particular, in case of structured porosity the mechanical properties demonstrate anisotropic behavior. For specialized applications there is an interest to be able to design materials with specified anisotropic properties or with properties varying in space. In order to design and optimize porous structures with specific anisotropic properties, a flexible simulation model is developed and tested to predict and understand the mechanical anisotropic properties of a large variety of porous structures. In order to be able to change the geometric pore structure without recreating a new model, the pore structure is implemented into a space dependent smoothed binary function. A comparison is made between results obtained with FEM models with a fully defined geometry and the FEM model with the porosity function to describe the pore structure in order to evaluate and quantify the error that is introduced by the latter implementation and investigate the possibility to mitigate the error. The model results are also compared with experimental en numerical results reported in literature.

A Factor-Analytic Study Exploring the Factors of Co-Worker Cohesion

2010 ◽  
Vol 3 ◽  
pp. 42-53 ◽  
Author(s):  
Kathryn von Treuer ◽  
Matthew Fuller-Tyszkiewicz ◽  
Barbara Atkinson
Keyword(s):  
Factor Structure ◽  
Lower Order ◽  
Conceptual Models ◽  
Group Performance ◽  
Higher Order ◽  
Factor Analyses ◽  
Online Questionnaire ◽  
First Order ◽  
Order Factor ◽  
The Relationship

AbstractDespite the applied importance of cohesion within organisational settings, researchers have yet to reach consensus about the dimensionality of group cohesion, and therefore appropriate tools for its measurement. The way that cohesion has generally been conceptualised has changed over time, but the measures appear not to reflect the underlying theory. This deficiency has impeded attempts to explore the relationship between co-worker cohesion and group performance (Beal et al., 2003; Mullen & Copper, 1994). Given inconsistent findings from previous factor analyses of cohesion, the present study employed exploratory means to help clarify the factor structure of cohesion within the workplace. Potential participants were recruited via the researchers' social networks. This snowballing technique led to 236 participants completing the online questionnaire. Exploratory factor analysis revealed four first-order factors of team commitment, friendliness, interpersonal conflict and communication that collectively accounted for 55.17% of the variance shared among the 75 cohesion items. Subsequently, a single higher-order factor was extracted which accounted for over half of the co-variation among the first order factors. This higher-order factor seems to reflect a general cohesion factor, as it was loaded by a diffuse collection of items, including those from the four lower-order factors as well as items that failed to load onto these lower-order factors. While there were similarities between these results and those of previous studies, the present factor structure did not map perfectly onto any of the existing conceptual models of cohesion. This finding highlights the need to incorporate some alternate factors that have previously been given little consideration.

scholarly journals Do You Know That I Know That You Know…? Higher-Order Beliefs in Survey Data*

2021 ◽  
Author(s):  
Olivier Coibion ◽  
Yuriy Gorodnichenko ◽  
Saten Kumar ◽  
Jane Ryngaert
Keyword(s):  
Survey Data ◽  
Information Model ◽  
Higher Order ◽  
Infinite Regress ◽  
Economic Agents ◽  
First Order ◽  
Noisy Information ◽  
Long Run ◽  
Information Models ◽  
The Relationship

Abstract We implement a new survey of firms, focusing on their higher-order macroeconomic expectations. The survey provides a novel set of stylized facts regarding the relationship between first-order and higher-order expectations of economic agents, including how they adjust their beliefs in response to a variety of information treatments. We show how these facts can be used to calibrate key parameters of noisy-information models with infinite regress as well as to test predictions made by this class of models. We also consider a range of extensions to the basic noisy-information model that can potentially better reconcile theory and empirics. While some extensions like level-k thinking are unsuccessful, incorporating heterogeneous long-run priors can address the empirical shortcomings of the basic noisy-information model.

Dual systems for all: Higher-order, role-based relational reasoning as a uniquely derived feature of human cognition

2019 ◽  
Vol 42 ◽  
Author(s):  
Daniel J. Povinelli ◽  
Gabrielle C. Glorioso ◽  
Shannon L. Kuznar ◽  
Mateja Pavlic
Keyword(s):  
Temporal Reasoning ◽  
Higher Order ◽  
Important Case ◽  
Human Cognition ◽  
Relational Reasoning ◽  
Dual Systems ◽  
First Order ◽  
Reasoning System ◽  
Role Based

Abstract Hoerl and McCormack demonstrate that although animals possess a sophisticated temporal updating system, there is no evidence that they also possess a temporal reasoning system. This important case study is directly related to the broader claim that although animals are manifestly capable of first-order (perceptually-based) relational reasoning, they lack the capacity for higher-order, role-based relational reasoning. We argue this distinction applies to all domains of cognition.

Challenging the Multidimensional Conception of Perceived Person-Environment Fit

2020 ◽  
pp. 1-9
Author(s):  
Julian M. Etzel ◽  
Gabriel Nagy
Keyword(s):  
Higher Education ◽  
University Students ◽  
Educational Outcomes ◽  
Factor Model ◽  
Higher Order ◽  
Substantial Proportion ◽  
Unique Variance ◽  
First Order ◽  
Person Environment Fit ◽  
Order Factor

Abstract. In the current study, we examined the viability of a multidimensional conception of perceived person-environment (P-E) fit in higher education. We introduce an optimized 12-item measure that distinguishes between four content dimensions of perceived P-E fit: interest-contents (I-C) fit, needs-supplies (N-S) fit, demands-abilities (D-A) fit, and values-culture (V-C) fit. The central aim of our study was to examine whether the relationships between different P-E fit dimensions and educational outcomes can be accounted for by a higher-order factor that captures the shared features of the four fit dimensions. Relying on a large sample of university students in Germany, we found that students distinguish between the proposed fit dimensions. The respective first-order factors shared a substantial proportion of variance and conformed to a higher-order factor model. Using a newly developed factor extension procedure, we found that the relationships between the first-order factors and most outcomes were not fully accounted for by the higher-order factor. Rather, with the exception of V-C fit, all specific P-E fit factors that represent the first-order factors’ unique variance showed reliable and theoretically plausible relationships with different outcomes. These findings support the viability of a multidimensional conceptualization of P-E fit and the validity of our adapted instrument.

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