Compliant Subject Research Articles

Singularity-free practical finite-time force control for a compliant grinding mechanism subject to hysteresis nonlinearity and asymmetric time-varying air pressure constraints

Singularity-free practical finite-time force control for a compliant grinding mechanism subject to hysteresis nonlinearity and asymmetric time-varying air pressure constraints

Surface wrinkling of a film coated to a graded substrate

We study the surface wrinkling of a stiff thin elastic film bonded to a compliant graded elastic substrate subject to compressive stress generated either by compression or growth of the bilayer. Our aim is to clarify the influence of the modulus gradient on the onset and surface pattern in this bilayer. Within the framework of finite elasticity, an exact bifurcation condition is obtained using the Stroh formulation and the surface impedance matrix method. Further analytical progress is made by focusing on the case of short wavelength limit for which the Wentzel–Kramers–Brillouin method can be used to resolve the eigenvalue problem of ordinary differential equations with variable coefficients. An explicit bifurcation condition is obtained from which the critical buckling load and the critical wavelength are derived asymptotically. In particular, we consider two distinct situations depending on the ratio β of the shear modulus at the substrate surface to that at infinity. If β is of O(1) or small, the parameters related to modulus gradient all appear in the higher-order terms and play an insignificant role in the bifurcation. In that case, it is the modulus ratio between the film and substrate surface that governs the onset of surface wrinkling. If, however, β≫1, the modulus gradient affects the critical condition through leading-order terms. Through our analysis we unravel the influence of different material and geometric parameters, including the modulus gradient, on the bifurcation threshold and the associated wavelength which can be of importance in many biological and technological settings.

Subjects of tradition: cultural construction and Irish comprador capitalism

ABSTRACT On the weekend of the 50th anniversary of Bloody Sunday, the Irish Consulate in Chicago memorialised a different occasion: the 86th anniversary of the death of Francis O’Neill (1848–1936), a Cork-born collector of Irish music in the United States. This paper posits that the sociopolitical construction “Irish traditional culture” constitutes an exercise of power over land and bodies, shaping and sustaining the structures of the island’s political economy as part of a racial/colonial/imperial project. My argument centres James Byrne (1868–1931), an itinerant piper “discovered” in Kilkenny in 1903. O’Neill’s account of Byrne’s life demonstrates the development of an ideological narrative of tradition as the foundation of Irish modernity. To deterritorialise land-based practices and construct a White Irish citizen subject to global capital, colonial technologies of governance mobilise resources from “authentic” points of origin, inventing their administrators as the heroic saviours of vanishing culture. James Byrne, in contrast, is situated as a possession containing value to be extracted and as a contaminated body refusing to become a compliant capitalist subject harnessed to empire. By interrogating this narrative, I hope to foster nuanced discussion around the enduring structural interdependence of “Irishness” with transnational political economy.

The multiple logics of market-based governance: How the sharing economy platform Airbnb governs user conduct

Building upon the rich tradition of research on governmentality, this paper introduces the notion of market-based governance (i.e. the coordinated efforts of companies to align the conduct of its constituents with the institutional norms, values and interests of the company), and presents an empirical investigation of market-based governance in the context of a sharing economy platform, Airbnb. Whereas existing governmentality research has focused on specific discourses or aspects of governance in the marketplace, our aim is to develop broader-spectrum conceptual tools for ‘ordering’ the increasingly multifaceted forms of marked-based governance. We show that Airbnb mobilizes three distinct logics of governance (i.e. the regulatory, competitive and communitarian) which subsume diverse modes of power (i.e. the sovereign, disciplinary and pastoral) that contribute to the cultivation of governable subjects (i.e. the compliant subject, entrepreneurial subject and community member). The theoretical framework developed in this work is applied to critically reflect on emergent forms of market-based governance, the dilemmas of multi-logic governance and the uneven geographies of market-based governance.

Three-dimensional adaptive mesh refinement in stress-constrained topology optimization

Structural optimization software that can produce high-resolution designs optimized for arbitrary cost and constraint functions is essential to solve real-world engineering problems. Such requirements are not easily met due to the large-scale simulations and software engineering they entail. In this paper, we present a large-scale topology optimization framework with adaptive mesh refinement (AMR) applied to stress-constrained problems. AMR allows us to save computational resources by refining regions of the domain to increase the design resolution and simulation accuracy, leaving void regions coarse. We discuss the challenges necessary to resolve such large-scale problems with AMR, namely, the need for a regularization method that works across different mesh resolutions in a parallel environment and efficient iterative solvers. Furthermore, the optimization algorithm needs to be implemented with the same discretization that is used to represent the design field. To show the efficacy and versatility of our framework, we minimize the mass of a three-dimensional L-bracket subject to a maximum stress constraint and maximize the efficiency of a three-dimensional compliant mechanism subject to a maximum stress constraint.

Topology optimization of compliant mechanisms with stress constraints and manufacturing error robustness

This work proposes a robust formulation to address the compliant mechanism design problem subject to both stress constraints and manufacturing uncertainty. The proposed formulation is an extension of the robust approach for compliant mechanism design based on eroded, intermediate and dilated projections. The novelty in this proposal comes from inclusion of a stress failure criterion in each projected field, in order to ensure compliant mechanisms that satisfy the stress failure criterion even in the presence of uniform manufacturing variations. The objective of the optimization problem is the minimization of the maximum displacement at the output port of the mechanism, given eroded, intermediate and dilated designs, subjected to upper and lower volume constraints and one stress constraint per finite element on each of the three projected fields. The objective function is weighted by the volume of the dilated topology, in order to avoid possible numerical instabilities that may occur when the upper volume constraint is not active. Several examples are solved and the optimized results are post-processed with body-fitted finite element meshes. Numerical results demonstrate that: 1) the proposed stress-constrained robust approach provides results in which both maximum stress and output displacements are robust with respect to uniform boundary variations; however, while the maximum stress is almost insensitive to manufacturing variations, the output displacement does show some degradation when compared with the traditional robust approach; 2) the traditional robust approach, i.e., without the stress considerations, provides results in which the maximum stress has unpredictable and non-smooth behavior after uniform boundary variation; and 3) the stress-constrained deterministic approach, i.e., without considering the manufacturing uncertainty, provides results in which both maximum stress and output displacements are non-robust with respect to uniform boundary variations.

An Experimental Investigation of Closed-Loop Impedance Pumping in a Compliant, Elastic Tube Millistructure by Variation of Perturbation Location

Flow through a fluid-filled compliant tube microstructure subject to periodic perturbations is not widely reported. An understanding of this phenomena is sought herein, as it may be useful for design of biological flows in microfluidic devices. An experiment conducted at the milli-scale to study the fluid flow produced within a closed-loop network of tubing, having a compliant millitube section subject to periodic perturbations from a probe is presented, and provides a basis for a micro-scale experiment. To test the fluid response, the boundary of the compliant millitube section was periodically perturbed by the probe at a variety of frequencies at five locations. Experimental results demonstrate fluid circulation within the closed-loop of tubing, which varies significantly with the frequency and location of applied perturbations. Overall, the study herein illustrates a unique design for pumping which utilizes periodic vibrations of a compliant tube structure to create a net positive displacement of fluid.

Effect of melting heat transfer on peristalsis in the presence of thermal radiation and Joule heating

Mathematical model is developed for peristaltic flow of viscous fluid through a compliant wall channel subject to melting heat transfer. Fluid is incompressible and magnetohydrodynamic. Analysis has been performed in the presence of Joule heating and thermal radiation. Solutions for small wave number are obtained. Physical quantities of interest are examined for various parameters of interest.

Dealing with instability in bimanual and collaborative tasks.

In the context of unstable tasks, whenever the dynamics of the interaction are unknown, our ability to control an object depends on the predictability of the sensory feedback generated from the physical coupling at the interface with the object. In the case of physical human-human interaction, the haptic sensory feedback plays a primary role in the construction of a shared motor plan, being the channel for the mutual sharing of intentions. The present work addresses the issue of strategy selection in contexts in which instability is arising both from the environment, i.e. controlling a compliant object subject to nonlinear forces, and from the interaction with a partner, i.e. carrying out a bimanual balancing task in the presence of disturbing force-fields.

Imaging Radiation Doses and Associated Risks and Benefits in Subjects Participating in Breast Cancer Clinical Trials.

Medical imaging is commonly required in breast cancer (BC) clinical trials to assess the efficacy and/or safety of study interventions. Despite the lack of definitive epidemiological data linking imaging radiation with cancer development in adults, concerns exist about the risks of imaging radiation-induced malignancies (IRIMs) in subjects exposed to repetitive imaging. We estimated the imaging radiation dose and IRIM risk in subjects participating in BC trials. The imaging protocol requirements in 10 phase III trials in the adjuvant and advanced settings were assessed to estimate the effective radiation dose received by a typical and fully compliant subject in each trial. For each study, the excess lifetime attributable cancer risk (LAR) was calculated using the National Cancer Institute's Radiation Risk Assessment Tool, version 3.7.1. Dose and risk calculations were performed for both imaging intensive and nonintensive approaches to reflect the variability in imaging performed within the studies. The total effective imaging radiation dose was 0.4-262.2 mSv in adjuvant trials and 26-241.3 mSv in metastatic studies. The dose variability resulted from differing protocol requirements and imaging intensity approaches, with computed tomography, multigated acquisition scans, and bone scans as the major contributors. The mean LAR was 1.87-2,410/100,000 in adjuvant trials (IRIM: 0.0002%-2.41% of randomized subjects) and 6.9-67.3/100,000 in metastatic studies (IRIM: 0.007%-0.067% of subjects). IRIMs are infrequent events. In adjuvant trials, aligning the protocol requirements with the clinical guidelines' surveillance recommendations and substituting radiating procedures with equivalent nonradiating ones would reduce IRIM risk. No significant risk has been observed in metastatic trials, and potential concerns on IRIMs are not justified. Medical imaging is key in breast cancer (BC) clinical trials. Most of these procedures expose patients to ionizing radiation, and the risk of second cancer development after imaging has prompted recent concerns and controversy. Using accepted calculation models, the number of malignancies were estimated that were potentially attributable to the imaging procedures performed during a patient's participation in BC clinical trials. The results show that for patients participating in metastatic trials, the risk of imaging radiation-induced malignancies is negligible. In adjuvant trials, some second cancers due to imaging could be expected, and measures can be taken to reduce their risk.

Topology optimization of compliant mechanisms with desired structural stiffness

This paper develops a bi-directional evolutionary structural optimization (BESO) method for topological design of compliant mechanisms. The design problem is reformulated as maximizing the flexibility of the compliant mechanism subject to the mean compliance and volume constraints. Based on the finite element analysis, a new BESO algorithm is established for solving such an optimization problem by gradually updating design variables until a convergent solution is obtained. Several 2D and 3D examples are presented to demonstrate the effectiveness of the proposed BESO method. A series of optimized mechanism designs with or without hinge regions are obtained. Numerical results also indicate that the flexibility and hinge-related property of the optimized compliant mechanisms can be controlled by the desired structural stiffness.

A king named Nicki: strategic queerness and the black femmecee

This article explores the deployment of race, queer sexuality, and femme gender performance in the work of rapper and pop musical artist Nicki Minaj. The author argues that Minaj's complex assemblage of public personae functions as a sort of “bait and switch” on the laws of normativity, where she appears to perform as “straight” or “queer,” while upon closer examination, she refuses to be legible as either. Rather than perpetuate notions of Minaj as yet another pop diva, the author proposes that Minaj signals the emergence of the femmecee, or a rapper whose critical, strategic performance of queer femininity is inextricably linked to the production and reception of their rhymes. This article engages a pair of music video releases that reflect the range of Minaj's gender performances as cinematic lenses into the strategic moves that Minaj is able to make from her femmecee stance. King Nicki's hypervisibility as a black femmecee and refusal to cede to any regime of recognition confound the multiple common senses that seek to produce her as a compliant subject.

Phase II Randomized Trial Of Radiation-Free Central Nervous System (CNS) Prophylaxis Comparing Intrathecal Triple Therapy With Liposomal Cytarabine (DepoCyte®) In Adult Acute Lymphoblastic Leukemia (ALL)

Phase II Randomized Trial Of Radiation-Free Central Nervous System (CNS) Prophylaxis Comparing Intrathecal Triple Therapy With Liposomal Cytarabine (DepoCyte®) In Adult Acute Lymphoblastic Leukemia (ALL)

New PR Pseudo-rigid-body Model of Compliant Mechanisms Subject to Combined Loads

Based on the pseudo-rigid-body model(PRBM),a new 2-Degree of freedom pseudo-rigid-body model with a prismatic pair is proposed.The axial displacement and lateral displacement is presented by the prismatic pair and revolute pair,respectively,and so the deflection of a compliant link subject to a combined force and moment loads can be simulated.The PR pseudo-rigid-body model of planar compliant mechanism is developed.A three-dimensional optimization for the characteristic radius factors and a linear regression method for the spring stiffness coefficients are presented.The advantage of the PR pseudo-rigid-body model is illustrated numerically through the comparison with the 1R,2R PRBM models and compliant link.

Methadone Maintenance Treatment: Disciplining the ‘Addict’

This article examines key aims, objectives, technologies, strategies, and procedures utilised in Australian methadone maintenance programs over the past thirty years. An examination of the major policy documents reveal that, in addition to medico-health concerns, methadone programs have been strategically deployed to manage specific sociopolitical problems including illicit drug use, crime, and the spread of infectious diseases. The techniques, technologies, and procedures utilised in methadone programs and the 'disciplinary monotony 'of the methadone regime itself aim to produce a more compliant, conforming, and self-regulating subject. It is argued that the promotion of methadone maintenance as a 'treatment' modality obscures these disciplinary objectives and the political goals that have fostered them.

Methadone Maintenance Treatment: Disciplining the ‘Addict’

This article examines key aims, objectives, technologies, strategies, and procedures utilised in Australian methadone maintenance programs over the past thirty years. An examination of the major policy documents reveal that, in addition to medico-health concerns, methadone programs have been strategically deployed to manage specific sociopolitical problems including illicit drug use, crime, and the spread of infectious diseases. The techniques, technologies, and procedures utilised in methadone programs and the ‘disciplinary monotony’ of the methadone regime itself aim to produce a more compliant, conforming, and self-regulating subject. It is argued that the promotion of methadone maintenance as a ‘treatment’ modality obscures these disciplinary objectives and the political goals that have fostered them.

SARS in Canada and China: Two Approaches to Emergency Health Policy

China and Canada addressed the transnational 2003 SARS outbreak within a common, multilevel network of public‐health expertise. The two countries deployed distinct public‐health strategies, and faced distinct levels of resistance. This article addresses this comparison. During this epidemic “state of exception,” both countries adopted emergency policy instruments and overall policy styles. However, Chinese emergency boundary policing corresponded better to everyday experience than did hospital‐based screening in Canada, and China's policing targeted collectivities where Canada emphasized individual case tracking. While Canadian efforts were smaller in scale and faced infrastructural deficiencies, prior campaigns to address endemic health problems formed a basis for compliant popular subject positions. Power/resistance relations and their cultivation during endemic conditions must become the center of analyzing effective approaches to emergency planning.

COUPLED TRANSVERSE AND AXIAL MOTION OF A COMPLIANT STRUCTURE IN RESPONSE TO VORTEX-SHEDDING LOADS

A compliant offshore tower is modelled as a structure having extensional and transverse degrees of freedom. McIver's extension of Hamilton's principle is applied to the system, resulting in coupled non-linear equations of motion, due to the assumption of small strain and moderate rotation. The equations of motion are discretized using finite differences and solved numerically. Several forms for the vortex-shedding load are tested, as well as experimental force data. To better understand the model response, Monte Carlo simulations are performed. The results show the feasibility of the present model for representing the response of a compliant structure subject to transverse loading.

Literacy and Literate Subjects in a Health and Physical Education Class: A Poststructuralist Analysis

In this paper an analysis is made of 15 minutes in a year 12 health and Physical Education class, 2 weeks prior to the final exam. The text of student and teacher talk is analyzed to show the ways that a semi-literate male teacher is supported and assisted by an orally competent group of female students to produce himself as a competent, authoritative, literate teacher. At the same time, these female students produce themselves as literate and glean information to enable them to produce themselves as literate in the exam. The specified task of the analysis was to focus on literacy practices in relation to Andrea, a relatively silent student. The problems of analyzing silence are discussed, and the positioning of Andrea as non-literate, compliant subject is also analyzed.

A comparison of prompting strategies for improving appointment compliance of hypertensive individuals

This study compared four strategies designed to encourage hypertensive individuals to seek treatment. Following a missed health center appointment, 148 individuals were identified as either borderline or clinical hyptertensive. Each individual was assigned to one of four prompting conditions: telephone call, home visit, postcard, or a rotating condition involving all three methods. Subjects were contacted a maximum of three times or until they complied with the health center appointment. For both borderline and clinical hypertensive individuals, the rotating condition was most effective, yielding compliance rates of 75% and 88% respectively. For all message modes, the second contact was the most effective contact. Home visits were the most expensive method per compliant subject, followed in order by the postcard, rotating, and telephone strategies. The rotating condition yielded impressive compliance rates at a relatively low cost per compliant subject.