Boundary Of Inclusion Research Articles

The Sound of Navajo Country: Music, Language, and Diné Belonging

The Sound of Navajo Country: Music, Language, and Diné Belonging

Electromagnetic field generated by acoustic wave scattering at a poroelastic inclusion located in a fluid

The study of elastic wave propagation in poroelastic media is of considerable scientific interest because of some effects that do not appear in monophasic elastic or viscoelastic media. In the case of interconnected pores containing a moving fluid in a poroelastic medium, there exist two types of longitudinal waves. In heterogeneous porous media, the energy of elastic oscillations is redistributed due to mutual transformation of elastic waves of different types at the inclusion boundaries. The filtration flow that appears there results in the case of polar fluids in a displacement of electric double layers at the pore boundaries, and, as a consequence, in generation of an electromagnetic field.We consider the problem of the scattering of an elastic wave by a spherical poroelastic inclusion in a fluid. The solution was obtained for sufficiently low frequencies so that the dispersion of the elastic wave on individual grains of the porous media may be neglected and the averaged equations of the mechanics of continuous media (at the so-named mesoscale) may be used. In order to describe the elastic wave propagation, we have used the Pride system of electrokinetic equations. For the solution of our problem, we have applied the decomposition of the potentials of acoustic and electromagnetic waves into spherical harmonics. We have obtained the dependencies of the generated electromagnetic field on the inclusion porosity and the fluid properties in pores. The results were obtained for fully open pore interface at the inclusion boundary.

Equilibrium problem for a thermoelastic Kirchhoff-Love plate with a delaminated flat rigid inclusion.

A new mathematical model describing an equilibrium of a thermoelastic heterogeneous Kirchhoff-Love plate is considered. A corresponding nonlinear variational problem is formulated with respect toa two-dimensional domain with a cut. This cut corresponds to an interfacial crack located on a given part of the boundary of a flat rigid inclusion. The flat inclusion is described by a cylindrical surface. Due tothe presence of the flat rigid inclusion in the plate, restrictions of the functions describing displacements to the corresponding curves satisfy special constraints having a linear form. Displacement boundary conditions of an inequality type are set on the crack faces that ensure a mutual non-penetration of opposite crack faces. Solvability of the problem is proved. Under the assumption that the solution of the variational problem is smooth enough, an equivalent differential formulation is found. This article is part of the theme issue 'Non-smooth variational problems and applications'.

‘Promising victimhood’: contrasting deservingness requirements in refugee resettlement

ABSTRACT In today’s migration and refugee governance, refugees are increasingly required to demonstrate both vulnerability and assimilability to be considered deserving of protection and territorial access. This article advances the notion of ‘promising victimhood’ [Chauvin, Sébastien, and Blanca Garcés-Mascareñas. 2018. The Myth of Humanitarianism: Migrant Deservingness, Promising Victimhood, and Neoliberal Reason. Barcelona] as a fruitful concept to capture the contrasting demands refugees face: policies and practices that require refugees to demonstrate that they are currently vulnerable and at risk, yet willing and able to ‘overcome’ their vulnerability to become law-abiding, self-sufficient and culturally malleable members of their host societies in the future. Taking the example of selection practices in refugee resettlement to Europe, I show how ‘promising victimhood’ is characterised by tensions between vulnerability and three dimensions of assimilability: (1) security, (2) economic performance, and (3) cultural ‘fit’. The analysis highlights how social markers of inter alia nationhood/race/religion, gender, sexuality and age shape assessments of both vulnerability and assimilability and thereby, which groups get to be seen as more deserving of access than others. By further developing promising victimhood as a concept, the article advances a more comprehensive understanding of deservingness and of the complex – gendered, racialised and age-differentiated – boundaries of inclusion and exclusion refugees face in today’s protection regime.

Dynamic analysis of the different types of elliptic cylindrical inclusions subjected to plane SH‐wave scattering

The complex boundary of the elliptical inclusion rendered it difficult to solve the problem of wave scattering. In this study, the steady‐state response was analyzed using the wave function expansion method. Subsequently, the Ricker wavelet was employed as the transient disturbance, and Fourier transform was used to determine the distribution of transient dynamic stress concentration around the elliptical inclusion. The effects of wave number, elliptical axial ratio, and difference in material properties on the distribution of the dynamic stress concentration around the elliptical inclusion were evaluated. The numerical results revealed that the dynamic stress concentration always appeared at both ends of the major axis and minor axis of the elliptical inclusion, and the difference in material properties between the inclusion and medium influenced the variations in the dynamic stress concentration factor with the wave number and elliptical axial ratio.

Numerical computation of the effective thermal conductivity of two-phase composite materials by digital image analysis

We consider the numerical determination of the effective thermal conductivity of 2D, two-phase composite materials, whose microstructural geometries are described by digital images. More specifically, key microstructural data pertaining to the spatial distribution and volume fractions of the constituent phases in the material are extracted, along with the shapes of the interphase boundaries, using computer vision techniques. For inclusions of simple shapes (polygons, circles, ellipses), the extracted interphase boundary data is easily obtained and can be exploited immediately (e.g. polygonal vertices) or can be fitted with smooth curves, using least square error minimization techniques in order to reconstruct parametric representations in the case of circular or elliptical boundaries. For more intricate microstructure geometries characterized by clustered or agglomerated intersecting inclusions, piecewise cubic spline functions are adopted to obtain a least-square fitting of the interphase boundaries. The effective thermal conductivities are then calculated based on a boundary integral formulation defined over the reconstructed inclusion boundaries. They are expressed in terms of power series expansions of a conductivity contrast parameter of the constituent phases in the material. To accelerate the convergence of these expansions, nonlinear transformations (known as Padé Approximants) are used to yield rational approximations of the effective thermal conductivity tensor. Tests conducted on a variety of 2D, two-phase microstructures yielded accurate results over a wide range of microstructure image resolution, regardless of the contrast parameters of the constituent phases, thus, validating the efficacy and robustness of the proposed scheme.

Perturbation of the elastic and thermoelectric fields caused by a rigid inclusion in a thermo-electro-elastic full plane

The two-dimensional thermoelectric coupling problem of a rigid inclusion embedded in a thermoelectric material subjected to uniform electric current density or uniform energy flux at infinity is studied, where the electric insulated and adiabatic properties on the boundary of the rigid inclusion are considered. Compared with previous reports, the explicit and analytic solutions of Kolosov-Muskhelishvili (K-M) potentials in a compact form are obtained when the shape of rigid inclusion is described by Laurent polynomial with finite N terms, and the rigid-body displacement of the rigid inclusion relative to the matrix is considered to make the boundary constraints exactly satisfied. The rigid-body displacement, thermoelectric field and stress around the boundary are analyzed. The results show that the rigid-body displacements caused by the uniform electric current density or uniform energy flux applied alone at infinity have different distributions; as the load direction changes, the electric current density (energy flux) and stress on the boundary are periodically distributed along the direction of obtaining the maximum value, and the maximum thermoelectric concentration and stress concentration happen in different load directions.

Problematizing Access to Higher Education for Refugee and Globally Displaced Students: What’s the Problem Represented to Be in Canadian University Responses to Syrian, Afghan and Ukrainian Crises?

The UNHCR’s 15by30 campaign to increase refugee student enrolment in higher education to 15% by 2030 is a lofty goal. Canadian higher education institutions have a role to play in contributing to this policy goal, along with advocacy efforts from refugee student groups, community-based organizations, government, and international organizations. The aim of this study is to look critically at how the issue of access to higher education for refugee and globally displaced people is represented through Ontario’s universities’ responses to federal government initiatives to crises in Syria, Afghanistan and Ukraine. In this study, we use Bacchi’s (2009) “What’s the problem represented to be?” approach to policy analysis and, drawing on Dillabough’s (2022) critique of modernity in higher education, we argue that university responses related to refugee and globally displaced student access to higher education offer the possibility to reflect on the paradoxical tensions of the problem space in Canadian higher education. In our findings, we discuss how the problem of refugee and displacement crisis was represented differently in response to differences in geopolitical conditions and government policies, as we demonstrate how representations of material problems and categories of “citizenship” and “geographical location” in the universities’ responses contributed to creating boundaries of inclusion and exclusion for access. Finally, we show how the creation of educational programs for “globally displaced people” during the period related to the Ukrainian crisis perpetuates the logic of colonialism in the universities’ responses.

CRACK INITIATION ALONG THE INTERPHASE BOUNDARIES OF THE “PHASE SIDE BY SIDE” TYPE HETEROPHASE INCLUSIONS

Purpose of research. Investigation into crack initiation features in heterophase inclusions of the “phase side by side” type during steel deformation. Methods. Destruction of various types heterophase inclusions is investigated during the deformation of samples from steels 08Ti, 08Al, 12MnSi, 08unk, 09Mn2Si, 08GSiAlTiV in the temperature range 20...1 200 °С. Samples of 08Ti and 08Al steels are subjected to tension, compression and bending, steel HB-57 − to tension and compression, steel 08unk, 08Cr, ATs45X ,ATs18XGT − to tension in vacuum at temperatures of 20...1 200 °С on experimental settings with special grips, which motion speed was 20 mm/min. Methods of investigation – petrography, X-ray microanalysis and optical microscopy were used. Results. It has been found that the diversity of phases composing the heterophase inclusions of the “phase side by side” type leads to their different behaviour under plastic deformation. The microcracks nitiation occurs along the internal interphase boundaries. Depending on the plasticity level of the phases composing the inclusion, these cracks can be brittle or ductile, which is also related to the effects of the deformation temperature. The features of microcracks initiation for different combinations of heterophase inclusions plastic and non-deformed phases of the “phase side by side” type are analysed. The interaction between heterophase inclusions of the “phase side by side” type and the steel matrix during deformation is discussed. Scientific novelty. The features of microcrack initiation related to heterophase inclusions of “phase side by side” type with different combination of brittle and plastic phases during steels deformation in a wide temperature range is determined. It was found that the microcracks initiation and spreading within inclusions “phase side by side” type occurs both in phases and along internal interphase boundaries. It is shown that the critical degrees of samples deformation, at which significant microcracks along the internal interphase boundaries occur, depend on the temperature and the inclusion phase. The critical degrees of samples deformation, upon reaching which significant microcracks occurred along the internal interphase boundaries, depended on the temperature and the nature of the “phase side by side” inclusions. The values of the critical degrees of deformation determine the level of cohesive strength of the internal interphase boundaries of the heterophase inclusions “phase side by side”. Practical significance. The use of obtained results will make it possible to develop technologies for producing steels with regulated types of heterophase non-metallic inclusions. This will substantially improve their technological and performance characteristics and prevent the various defects formation in the steel pressure treatment and the products operation.

Unknown polynomial eigenstrains reconstruction with distributed dislocation technique for crack–inclusion interaction

The inverse formulation presents mode-I crack–inclusion interaction solution, based on Eshelby’s equivalent inclusion method (EIM) with an unknown filed of induced polynomial eigenstrains (IPE) inside an inclusion, combined with the distributed dislocations technique (DDT) to model the crack face with unknown perturbations in distributed dislocations (PDD). The expression for PDD, determined through Gauss–Chebyshev Quadrature integration of the singular integral equations, is recast in terms of the unknown coefficients of IPE, which form the only set of unknowns. The crack-face boundary condition is exactly satisfied in this step, without solving for the unknowns. The second boundary condition for continuity of stresses at the inclusion boundary is approximately satisfied through discrete-point collocation equations in a subsequent step through the inverse formation. For modest geometric and modulus ratio configurations, the method obtains the perturbed stress intensity factors with reasonable accuracy using only four terms in IPE.

Examining Nigeria’s Digital Identity Project as Tool for Economic Inclusion and Regional Integration

Access to the digitised economy has an increased penetration across the spectrum of Africa's rural and urban population. In Nigeria, which is the context of this study, there is a long unsettling debate delineating citizens residing within any locality in Nigeria as 'indigenes' or 'settlers'. This is at variance with the concept of 'transnational citizenship', which confers rights to social inclusion in any individual's nation-state. Digital identity registration becomes imperative to preserve social order and broaden the lines of inclusion for access to social services and monitoring access to the digital economy. The National Identity Number (NIN) is the digital identity for Nigerian citizens and residents, which can be leveraged for economic digitisation and regional and continental integration efforts. The research methodology employs descriptive and explanatory analysis of national, regional and continental policy frameworks applicable to Nigeria's digital identity management systems. Boundaries of inclusion, transnational citizenship and the Westphalian Treaty of nation sovereignty form the theoretical underpinning of the study. This is used to present digital identity as a vital tool for socioeconomic inclusion, regional and continental integration. The case study of the Schengen Agreement as a successful integrative digital identity system fostering economic integration in Europe forms the basis of the recommendation. This calls for the ultimate use of digital identity to enhance international operable smart border practice, which would in turn guarantee border security while encouraging the desired free movement of persons and goods within the African continent

Profound Disability, Equality and the Boundaries of Inclusion

The sub-title of a recent book on “belonging” for people with profound intellectual and multiple disabilities (PIMD) is “Pushing the boundaries of inclusion.” One aim of this paper is to establish where at least one of these boundaries lies. Enabling profoundly disabled people to be together with others is often inspired by the ideal that anybody and everybody can be fully included in their relationships with others. This inclusive ideal can take the form of relational equality—including people with PIMD as equals in our relationships with them. I explore the scope and limits of relational equality, and where, as with some profoundly disabled people, equality is out of reach, I look at two relational alternatives.

A Flexible Image-Guided Shape Reconstruction Framework for Electrical Impedance Tomography

Electrical Impedance Tomography (EIT) owns the advantages of safety, high temporal resolution and functional imaging characteristics, thus is considered as a promising medical/ industrial imaging modality. However, due to the ill-posedness of its inverse problem, the spatial resolution of EIT is low, which is greatly impeded its practical applications. A flexible image-guided shape reconstruction framework for EIT is proposed to alleviate the problem. A statistical inverse problem framework for image-guided inclusion boundary reconstruction is established to directly reconstruct the inclusion boundary and the corresponding conductivity distribution. The morphology prior information is extracted from the images obtained from other high resolution modes and is used to guide the boundary reconstruction process in the form of a conditional probability model. A series of simulation and experimental studies are carried out for different application backgrounds. The lung EIT imaging guided by CT image and EIT inclusion detection guided by B-ultrasound image are simulated and analyzed respectively. The results show that the proposed method has high applicability to prior images of different modes. It not only achieves high-precision shape reconstruction but also high-precision conductivity estimation under the guidance of accurate prior images. Meanwhile, the proposed method has high robustness to the possible influence of noise in prior images or incomplete structural information. Even if the information in the prior image is biased or incomplete, the proposed method can still achieve high precision boundary reconstruction and conductivity estimation. The results of quantitative analysis show that compared with the method without image prior, the proposed method has an average reduction of 70% in area error, while the conductivity estimation error is reduced by about 5 times on average.

Error-Constraint Deep Learning Scheme for Electrical Impedance Tomography (EIT)

As a new generation of noninvasiveness imaging modality, electrical impedance tomography (EIT) has broad application prospects to perform functional evaluation for human tissues and organs. Deep learning makes great breakthrough in recent years, and many different neural networks (NNs) have been applied to EIT image reconstruction for obtaining high resolution reconstruction images. However, the NN is hard to interpret, and the robustness and generalization ability of the network model cannot be guaranteed. In this study, a deep learning scheme namely error-constraint network (Ec-Net) is designed to remove the error of reconstruction images obtained by traditional reconstruction algorithm. By establishing the residual mapping between image and error, Ec-Net achieves more robust reconstruction performance and faster learning. Feature fusion module, dilated convolution block, and the structure of residual in residual are used to further improve the reconstruction accuracy for the inclusion boundary. The reconstruction results show that the proposed method can accurately reconstruct the irregular and sharp boundary of inclusions while showing good anti-noise ability for measurement noise higher than 30 dB. Even effective reconstruction can be obtained for new inclusions that have size/shape variations, which proves the generalization ability of Ec-Net model.

Scale-mediated marginalisation of Myanmar jewellers in China during the live-streaming trade era

ABSTRACT Since the late 1980s, generations of Myanmar jewellers have settled down in the Chinese border cities next to northern Myanmar. Currently, most of them are based in Dehong Prefecture, a border prefecture in southwestern China’s Yunnan Province. In the past few years, they have faced increasingly precarious economic and social conditions due to China’s anti-corruption campaign, the Belt and Road Initiative and the rise of live-streaming trade in the transnational jewellery business. Our study focuses on the Myanmar jewellers’ economic and social predicaments in the live-streaming era of the late 2010s. Applying the theory of urban scalar reconfiguration, this study argues that the economic and social marginalisation facing the Myanmar jewellers is produced by the prefecture’s urban scalar reconfiguration and the corresponding division of labour. It contends that the prefecture’s urban scalar reconfiguration redraws the boundary of inclusion and exclusion in the border urban space and reshapes the urban socioeconomic hierarchies in which the Myanmar immigrants are situated. The article provides an alternative approach to understanding the changes in transnational immigration in urban contexts. Ultimately, it presents an empirical case study of the much-neglected immigrant population in the China-Myanmar borderlands.

Immigration, Race, and Nation in the UK: The Politics of Belonging on Twitter

At a time of rising right-wing populism, the heightened political salience of immigration as an issue is linked to conceptions of ‘the national’. In this article, we analyse tweets from non-elites, defined as isolated users with low network influence, engaged in a ‘conversation’ about migration on Twitter. We investigate the values embedded in these attitudes, and what these tell us about constructions and contestations of the symbolic boundaries of the nation among ordinary people. Our corpus includes tweets posted in temporal proximity to the lifting of transitional controls on Romanian and Bulgarian migrants in the UK (1 October 2013 to 1 March 2014). Thematic analysis reveals a cohesive set of anti-immigrant or anti-immigration sentiments linked to UKIP and that express an exclusionary nationalism based on assumptions about race, ‘whiteness’ and entitlement. Also evident is a counter-narrative of pro-immigration sentiments that draw on multiple and sometimes contradictory values. Some of these values contest racialised understandings of the nation but do not coalesce in ways to disrupt the dominance of right-wing anti-immigrant sentiments on Twitter. Our findings demonstrate the importance of investigating values embedded in both anti and pro-immigration attitudes among non-elites and what these values indicate about the possibilities of re-framing migration debates among non-elites in ways that construct more inclusive symbolic national boundaries. In addition, in using the networked properties of Twitter engagement to identify non-elite users, we make a methodological contribution to scholarship on immigration attitudes.

Equality and Discrimination in the New World of Work

Gig work is now the career context of a significant share of the workforce across the world but still remains a 'black box' in many respects. In this symposium, we discuss the issues of equality and discrimination in the gig economy from multiple perspectives. The contributions include both theoretical and empirical examinations, quantitative and qualitative approaches, and instances of discrimination both against gig workers and by gig workers. The first presentation in this symposium provides a new understanding of gig-work careers as ones in which labour is defined independent of jobholders and their social context, introducing new boundaries of inclusion and exclusion. The second study, considering the role of the selectors and the selection context, provides a theoretical model that suggests the possibility of both persistence and absence of hiring discrimination in online gig-work platforms. These theoretical propositions are then followed by two empirical papers, each of which supports one of the competing hypotheses. Finally, discriminatory behaviour is compared across gig-work and traditional careers to investigate the difference in customers' perceptions. Researchers and practitioners could benefit from the research findings and ideas discussed in this symposium, as presentations provide theoretical and actionable insights, showcase new evidence, and raise new questions. Beyond the 'Ideal Worker'? Algorithmic Technology, Radical Equality, and Precarization in the Gig Ec Presenter: Patrizia Zanoni; U. Hasselt Does Discrimination Persist in the New World of Work? A Model of Hiring Discrimination in Online Gig Presenter: Mehri E. Baloochi; U. of Manitoba Presenter: Lukas Neville; U. of Manitoba Presenter: Arran Caza; U. of North Carolina, Greensboro Race and Gender in the Gig Economy: Evidence from Online Language Tutoring Presenter: Nathaniel Ming Curran; The Hong Kong Polytechnic U. Presenter: Lichen Zhen; U. of Southern California Presenter: Hernan Galperin; U. of Southern California Managing Stigma without Constraint: Examining Identity Management Dynamics for LGBT Employees in the Presenter: Katina Sawyer; George Washington U. Presenter: Anjali Bansal; MICA, Ahmedabad Presenter: Christian Noble Thoroughgood; Villanova U. Discrimination in the Gig Economy: Who's to Blame for Behavior? Presenter: Courtney Bryant; Michigan State U. Presenter: Alice Brawley Newlin; Gettysburg College

Remediation and Boundary Work in a Virtual Entrepreneur Community

Virtual communities are distinct from traditional communities of practice in that they are global, always on, and void of many of the social attributes that influence social behavior in offline contexts. This fundamentally alters our understanding of networked organizing, entrepreneurial ecosystems, and entrepreneurship as a professional field. This study focuses specifically on how virtual communities invoke newly visible forms of boundary work and social capital following one particularly stigmatizing event: entrepreneurial failure. The study evaluates the role of network structure as a mechanism for discursive boundary work in a virtual peer community. Through a statistical analysis of the relationship between a peer’s centrality in the /r/Entrepreneur subReddit network and the sentiment of their response to entrepreneurial failure narratives, I find support for the hypothesis that embeddedness, namely tenure, is directly related to stigmatization of failed members. However, by looking beyond the structure to the content of the tie, my findings suggest that such virtual communities are not closed, but open networks in which inclusive peer boundary work matters more to entrepreneurial persistence than stigmatization. Understanding these dynamics is critical to promoting social capital recovery from the stigma of organizational failure and vitality of a virtual community.

A dual-mode tactile hardness sensor for intraoperative tumor detection and tactile imaging in robot-assisted minimally invasive surgery

Intraoperative tumor detection and shape identification through manual palpation are routinely performed in traditional open surgeries to ensure complete tumor resection. However, most existing robot-assisted minimally invasive surgery (RMIS) systems lack tactile feedback and rely on vision heavily. Traditional tactile sensing methods require the sensor to be placed normal to the tissue surface. But this requirement cannot always be met due to the limited degrees of freedom and the complexity of the environment in confined spaces. This paper proposes a miniaturized piezoelectric tactile sensor for tissue hardness detection by measuring its electrical impedance spectrum. It has two unique detection modes in two orthogonal directions—transverse and longitudinal, and can detect hardness even when the contact angle is large. It is verified by simulations and experiments that both detection modes can be used to detect hardness in the normal contact condition. However, in the case of hardness detection at a large contact angle, the sensitivity of the sensor in the transverse detection mode is significantly higher than that in the longitudinal mode, implying that this mode is more suitable for the large-angle detection. The sensor is then tested on silicone phantoms with hard inclusions and also on an ex vivo porcine liver. In addition, a tactile imaging algorithm based on Gaussian process regression is used to generate the complete hardness distribution of the test sample, which is further processed to extract the shape and boundary of the hard inclusion. The results show that the accuracy of shape detection is high (recall ⩾ 95%, specificity ⩾ 97%), and the smallest feature size it could detect is 1.3 mm. This proves that the proposed tactile sensor has the potential to perform high-accuracy tumor detection in RMIS.

Older veterans: The materiality of reminiscence, making unknown histories knowable and forging social connections

Materials have long been used by individuals reflecting on personal histories, and researchers have evidenced the associated therapeutic value particularly among older populations. In this article, we consider older veterans’ reminiscence through attending interviews and workshops, focussing on the performative potential of engaging with materials collected throughout their service lives. By considering their use of in situ and post-hoc materials, two themes are explored: the use of materials to build a sense of belonging; and making unknown histories knowable. We consider how their sharing of materials (re)produces their past and present military identities, simultaneously drawing boundaries of inclusion and exclusion around what it means to be military or non-military (civilian). Through sharing materials, veterans facilitated discussions with both military and non-military persons, enabling feelings of connection and belonging.