rigid constraint
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Author(s):  
Isabella Pistone ◽  
Allan Lidström ◽  
Ingemar Bohlin ◽  
Thomas Schneider ◽  
Teun Zuiderent-Jerak ◽  
...  

Background: Although increasingly accepted in some corners of social work, critics have claimed that evidence-based practice (EBP) methodologies run contrary to local care practices and result in an EBP straitjacket and epistemic injustice. These are serious concerns, especially in relation to already marginalised clients.Aims and objectives: Against the backdrop of criticism against EBP, this study explores the ramifications of the Swedish state-governed knowledge infrastructure, ‘management-by-knowledge’, for social care practices at two care units for persons with intellectual disabilities.Methods: Data generated from ethnographic observations and interviews were analysed by applying a conceptual framework of epistemic injustice; also analysed were national, regional and local knowledge products within management-by-knowledge related to two daily activity (DA) units at a social care provider in Sweden.Findings: In this particular case of disability care, no obvious risks of epistemic injustice were discovered in key knowledge practices of management-by-knowledge. Central methodologies of national agencies did include perspectives from social workers and clients, as did regional infrastructures. Locally, there were structures in place that focused on creating a dynamic interplay between knowledge coming from various forms of evidence, including social workers’ and clients’ own knowledge and experience.Discussion and conclusions: Far from being a straitjacket, in the case studied management-by-knowledge may be understood as offering fluid support. Efforts which aim at improving care for people with disabilities might benefit from organisational support structures that enable dynamic interactions between external knowledge and local practices.<br />Key messages<br /><ul><li>Examining one case of disability care in Sweden, both social workers’ and clients’ experiences were included in EBP infrastructures.</li><br /><li>In this study, Swedish EBP infrastructures functioned more like fluid support than a straitjacket.</li><br /><li>Organisational structures that combine different knowledge sources at service providers can minimise the risk of epistemic injustice within social care.</li></ul>


Sensors ◽  
2021 ◽  
Vol 21 (18) ◽  
pp. 6307
Author(s):  
Marco Caruso ◽  
Angelo Maria Sabatini ◽  
Marco Knaflitz ◽  
Ugo Della Croce ◽  
Andrea Cereatti

The orientation of a magneto-inertial measurement unit can be estimated using a sensor fusion algorithm (SFA). However, orientation accuracy is greatly affected by the choice of the SFA parameter values which represents one of the most critical steps. A commonly adopted approach is to fine-tune parameter values to minimize the difference between estimated and true orientation. However, this can only be implemented within the laboratory setting by requiring the use of a concurrent gold-standard technology. To overcome this limitation, a Rigid-Constraint Method (RCM) was proposed to estimate suboptimal parameter values without relying on any orientation reference. The RCM method effectiveness was successfully tested on a single-parameter SFA, with an average error increase with respect to the optimal of 1.5 deg. In this work, the applicability of the RCM was evaluated on 10 popular SFAs with multiple parameters under different experimental scenarios. The average residual between the optimal and suboptimal errors amounted to 0.6 deg with a maximum of 3.7 deg. These encouraging results suggest the possibility to properly tune a generic SFA on different scenarios without using any reference. The synchronized dataset also including the optical data and the SFA codes are available online.


2021 ◽  
Author(s):  
Ahmad T. Kalaji

This thesis presents a flexible trailing edge mechanism capable of undergoing a change in camber for a wing section. The mechanism takes advantage of a rigid constraint between the ends of two flexible carbon fiber panels, which produces a deflection when there is a difference in length between the two panels. A prototype was designed and built and experimental data was collected for the deformation of the panels for different values of lengths and analyzed to find a function to describe the coefficients which form the polynomials describing the shape for each of the panels, based on the difference in length value. Deflection and deflection angle results were used to develop a controller which will calculate the required change in length based on a deflection or angle and a bottom panel length input.


2021 ◽  
Author(s):  
Ahmad T. Kalaji

This thesis presents a flexible trailing edge mechanism capable of undergoing a change in camber for a wing section. The mechanism takes advantage of a rigid constraint between the ends of two flexible carbon fiber panels, which produces a deflection when there is a difference in length between the two panels. A prototype was designed and built and experimental data was collected for the deformation of the panels for different values of lengths and analyzed to find a function to describe the coefficients which form the polynomials describing the shape for each of the panels, based on the difference in length value. Deflection and deflection angle results were used to develop a controller which will calculate the required change in length based on a deflection or angle and a bottom panel length input.


2021 ◽  
Vol 2021 ◽  
pp. 1-18
Author(s):  
Shijun Wang ◽  
Guanwei Luo

A two-degree-of-freedom periodically forced system with multiple gaps and rigid constraints is studied. Multiple types of impact vibrations occur at each rigid constraint and interact with each other, which results in the emergence of some complex transitions in the system. Through the cosimulation of the key parameters gap value δ between the two masses and the excitation force frequency ω, the types, existence areas, and bifurcation regularities of the periodic and subharmonic motions can be obtained on the (ω, δ)-parameter plane. In the corresponding three-dimensional surface diagram of the maximum impact velocity, the distribution law of the maximum impact velocity at each constraint can be obtained. The transition laws of fundamental impact motions in the low-frequency parameter domain are studied, and two types of transition regions in the transitions of adjacent fundamental impact motions are found: tongue-like regions and hysteresis regions. Moreover, these two types of transition regions show some atypical partitioning and deformation due to the combined effects of impact vibrations at each constraint. By combining the two-parameter plane diagram and the three-dimensional surface diagram, the effect of changing the gap values between each mass and the fixed constraint and the damping coefficient ζ on the dynamic characteristics of the system is studied. Combining the existence areas of periodic motions and the distribution of maximum impact velocity can provide guidance for the reasonable selection of system parameters.


2021 ◽  
Author(s):  
Johannes Sutter ◽  
Hubertus Fischer ◽  
Olaf Eisen

&lt;p&gt;Ice Sheet Models are a powerful tool to project the evolution of the Greenland and Antarctic Ice Sheets, and thus their future contribution to global sea-level changes. Probing the fitness of ice-sheet models to reproduce ongoing and past changes of the Greenland and Antarctic ice cover is a fundamental part of every modelling effort. However, benchmarking ice-sheet model data against real-world observations is a non-trivial process, as observational data comes with spatio-temporal gaps in coverage. Here, we present a new approach to assess the ability of ice-sheet models which makes use of the internal layering of the Antarctic Ice Sheet. We simulate observed isochrone elevations within the Antarctic Ice Sheet via passive Lagrangian tracers, highlighting that a good fit of the model to two dimensional datasets does not guarantee a good match against the three dimensional architecture of the ice-sheet and thus correct evolution over time. We show, that paleoclimate forcing schemes commonly used to drive ice-sheet models work well in the interior of the Antarctic Ice Sheet and especially along ice divides, but fail towards the ice-sheet margin. The comparison to isochronal horizons attempted here reveals, that simple heuristics of basal drag can lead to an overestimation of the vertical interior ice sheet flow especially over subglacial basins. Our model-observation intercomparison approach opens a new avenue to the improvement and tuning of current ice-sheet models via a more rigid constraint on model parameterisations and climate forcing which will benefit model-based estimates of future and past ice-sheet changes.&lt;/p&gt;


Author(s):  
D. Riccobelli ◽  
G. Noselli ◽  
A. DeSimone

Mechanical instabilities can be exploited to design innovative structures, able to change their shape in the presence of external stimuli. In this work, we derive a mathematical model of an elastic beam subjected to an axial force and constrained to smoothly slide along a rigid support, where the distance between the rod midline and the constraint is fixed and finite. Using both theoretical and computational techniques, we characterize the bifurcations of such a mechanical system, in which the axial force and the natural curvature of the beam are used as control parameters. We show that, in the presence of a straight support, the rod can deform into shapes exhibiting helices and perversions, namely transition zones connecting together two helices with opposite chirality. The mathematical predictions of the proposed model are also compared with some experiments, showing a good quantitative agreement. In particular, we find that the buckled configurations may exhibit multiple perversions and we propose a possible explanation for this phenomenon based on the energy landscape of the mechanical system.


2021 ◽  
Vol 276 ◽  
pp. 01020
Author(s):  
Suchun Chen ◽  
Shiwu Wang ◽  
Jinxing Li

General Secretary Xi Jinping proposed to take water resources as the maximum rigid restriction, emphasize using water resources as its capacity permits, and actively explore new ways of high-quality development with regional characteristics. Yongkang is a water shortage county in the southern water-rich area. The contradiction between insufficient water supply and rapid economic and social development and continuous improvement of ecological environment is more prominent. In this paper, industrial water users are taken as the key control objects, and the added value of unit water consumption is taken as the rigid constraint index of water resources. It is incorporated into the reform of “heroes per acre” and integrated with the existing water resources management system to design the collaborative promotion mechanism framework of general rigid constraint of water resources. Then, the application practice in Yongkang is carried out, and the responsibilities of various administrative departments are clarified.


Author(s):  
Alexander Lenger ◽  
Stephan Wolf ◽  
Nils Goldschmidt

AbstractIn a novel experimental design, we study how social immobility affects the choice among distributional schemes in an experimental democracy. We design a two-period experiment in which subjects first choose a distributional scheme by majority voting (“social contract”). Then subjects engage in a competitive real-effort task to earn points. Based on production success, participants are ranked from best to worst. In combination with the initially chosen scheme, these ranks determine the final payout of the first round, leading to a pattern of societal stratification. Participants are informed individually about points and rank, before the same sequence of voting, production and payoff determination is repeated in a second round. To test the effect of social immobility on choosing distributional regimes the experiment is conducted with and without a social immobility factor, i.e. a different weighting of the two rounds. In our standard scenario, payoffs are simply added. In our “social immobility setting”, we alter the game as follows: the actual income in round 2 is calculated by adding 0.2 times the raw payoff from the second production game and 0.8 times the income from round 1. With the higher importance of round 1 success, we simulate the fact that economic movement upwards and downwards in societies (“social mobility”) is a de facto rigid constraint: high and low incomes tend to reproduce themselves. Our main findings are that in the Equal Weight Treatment, most groups opt for complete equality in both rounds, while in the unequal weight setting the initial choice of equality is followed by a shift to the most competitive regime. In both treatments, we observe that those performing well in round 1 tend to vote for unequal schemes in round 2, while low-performers develop an even stronger “taste for equality”. This supports a central Rawlsian idea: behind an (experimental) “veil of uncertainty”, the lack of idiosyncratic information is strong enough to let people decide as if driven by social preferences. The different group decisions in round 2 suggest that for this to happen, stakes need to be sufficiently high. To our surprise, other factors like gender, social background or real-life income have hardly any impact on unveiled decision making. We conclude that in our experimental democracy, competition based income allocation (a “market economy”) finds support only if people are sufficiently well off. Hence, increasing inequality perpetuated by social immobility is likely to undermine the general support for market-based systems.


2020 ◽  
Author(s):  
Johannes Sutter ◽  
Hubertus Fischer ◽  
Olaf Eisen

Abstract. Ice Sheet Models are a powerful tool to project the evolution of the Greenland and Antarctic Ice Sheets, and thus their future contribution to global sea-level changes. Probing the fitness of ice-sheet models to reproduce ongoing and past changes of the Greenland and Antarctic ice cover is a fundamental part of every modelling effort. However, benchmarking ice-sheet model data against real-world observations is a non-trivial process, as observational data comes with spatio-temporal gaps in coverage. Here, we present a new approach to assess the ability of ice-sheet models which makes use of the internal layering of the Antarctic Ice Sheet. We simulate observed isochrone elevations within the Antarctic Ice Sheet via passive Lagrangian tracers, highlighting that a good fit of the model to two dimensional datasets does not guarantee a good match against the three dimensional architecture of the ice-sheet and thus correct evolution over time. We show, that paleoclimate forcing schemes commonly used to drive ice-sheet models work well in the interior of the Antarctic Ice Sheet and especially along ice divides, but fail towards the ice-sheet margin. The comparison to isochronal horizons attempted here reveals, that simple heuristics of basal drag can lead to an overestimation of the vertical interior ice sheet flow especially over subglacial basins. Our model-observation intercomparison approach opens a new avenue to the improvement and tuning of current ice-sheet models via a more rigid constraint on model parameterisations and climate forcing which will benefit model-based estimates of future and past ice-sheet changes.


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