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This study discusses the tracking trajectory issue of the exoskeleton under the bounded disturbance and designs an useful tracking trajectory control method to solve it. By using the proposed control method, the tracking error can be successfully convergence to the assigned boundary. Meanwhile, the chattering effect caused by the actuators is already reduced, and the tracking performance of the pneumatic artificial muscles (PAMs) elbow exoskeleton is improved effectively.

A prescribed performance sliding mode control method was developed in this study to fulfill the joint position tracking trajectory task on the elbow exoskeleton driven by two PAMs. In terms of the control structure, a dynamic model was built by conforming to the adaptive law to compensate for the time variety and uncertainty exhibited by the system. Subsequently, a super-twisting algorithm-based second-order sliding mode control method was subjected to the exoskeleton under the boundedness of external disturbance. Moreover, the prescribed performance control method exhibits a smooth prescribed function with an error transformation function to ensure the tracking error can be finally convergent to the pre-designed requirement.

From the theoretical perspective, the stability of the control method was verified through Lyapunov synthesis. On that basis, the tracking performance of the proposed control method was confirmed through the simulation and the manikin model experiment.

As revealed by the results of this study, the proposed control method sufficiently applies to the PAMs elbow exoskeleton for tracking trajectory, which means it has potential application in the actual robot-assisted passive rehabilitation tasks.

The purpose of this paper is to study the influence of the induction heating phenomenon during magnetic pulse forming (MPF) of thin walled tube components. The approach is based on the advanced use of the multiphysics finite element software FORGE® coupling electromagnetism, heat transfer and solid mechanics. Although the global contribution of thermal effects is found to be almost negligible with respect to the volume forces, it can be observed that localized softening due to the heating process induces shock absorbing behavior.

Due to the strong multiphysics couplings between solid mechanics, electromagnetism and heat transfer, it is not always obvious to quantify the contributions of the various physical phenomena. It is thus intended here to take advantage of the numerical framework and tool that has developed to dissociate and quantify the influence of Joule heating phenomena due to eddy currents during MPF processes.

In this paper, the sensitivity of the MPF process has been analyzed to the induction heating source term for a specific tube forming case. An analysis of the electric output signal shows that inductance sensitivity to heating remains small when compared to the mechanical deformation. Regarding mechanical analysis of the process, induction heating contribution has a very slight impact at the global scale, but its effect is more noticeable at the small scale where it is likely that the localized heating induces shock absorption properties through softening. The extension of these results to other materials (for which the thermal dependency of mechanical behavior is different), as well as to a larger range of energy inputs, still needs to be carried out. Such phenomena should be considered for instance for high precision forming.

The analysis of the influence of heating due to eddy currents in magnetic pulse forming processes has not been extensively studied. The originality of this work is to try to quantify its effect on the process by using a numerical-based approach.

Confronting the unveiled sophisticated structural and physical characteristics of permanent magnets, notably the samarium–cobalt (Sm-Co) alloy, This work aims to introduce a simulation scheme that can link physics-based micromagnetics on the nanostructures and magnetostatic homogenization on the mesoscale polycrystalline structures.

The simulation scheme is arranged in a multiscale fashion. The magnetization behaviors on the nanostructures examined with various orientations are surrogated as the micromagnetic-informed hysterons. The hysteresis behavior of the mesoscale polycrystalline structures with micromagnetic-informed hysterons is then evaluated by computational magnetostatic homogenization.

The micromagnetic-informed hysterons can emulate the magnetization reversal of the parameterized Sm-Co nanostructures as the local hysteresis behavior on the mesostructures. The simulation results of the mesoscale polycrystal demonstrate that the demagnetization process starts from the grain with the largest orientation angle (a) and then propagates to the surrounding grains.

The presented scheme depicts the demand for integrating data-driven methods, as the parameters of the surrogate hysteron intrinsically depend on the nanostructure and its orientation. Further hysteron parameters that help the surrogate hysteron emulate the micromagnetic-simulated magnetization reversal should be examined.

This work provides a novel multiscale scheme for simulating the polycrystalline permanent magnets’ hysteresis while recapitulating the nanoscale mechanisms, such as the nucleation of domains, and domain wall migration and pinning. This scheme can be further extended to simulate the part-level hysteresis considering the mesoscale features.

Phenomenologists are among the strongest opponents of logical positivism. Mostly associated with Edmund Husserl, phenomenology is essentially an analytical method or framework for describing and explaining social relationships and psychological orientations. Phenomenologists attempt to account for the subjective qualities which logical positivists and empiricists assume to be unreal or are mistakenly treated as objective observable phenomena. The authors note that phenomenology has been absorbed into the literature and the language of the field especially in terms of how people do and do not relate to bureaucratic organizations and government programs.

Aims to methodologically explain a phenomenological model with empirical contents for modelling ethics in socioeconomic development. Addresses a circular causality between state variables and policy variables for the case of socioeconomic development of Indonesia with ethics and values as important focus required for the private sector role.

This is a methodological paper with good empirical content prescribing policy recommendations for the role of ethics and values in the private sector in Indonesian socioeconomic development. Philosophy of science heads off the methodological part. This is combined with contextual elements of Islamic development financing instruments to highlight the need for ethics and values in the development of Indonesia, the largest Muslim nation.

The paper highlights how the Indonesia private sector and the Government need to corroborate the focus of ethics and values in the national development plan. This is a novel approach to modelling ethics and values and estimating it by circular causation system of regression equations answering the theme of social wellbeing through socioeconomic development.

The true empirical work would have used complexity methods. In the paper the simple approach has been maintained by using the system of circular causation related regression equations. This is part of an on‐going research project on unity of knowledge and its empirical application to specific problems of science and society including the social economy. Thus, the project presents challenging field of academic investigation for many.

Provides policy recommendations on how ethics and values ought to be incorporated in the socioeconomic development plan through private sector participation in Indonesia. The need for the role of private sector ethical consciousness in Socioeconomic development of Indonesia is highlighted.

This is an original contribution in the area of phenomenological investigation on ethics and how it can be modelled and applied in specific circumstances (Indonesia private sector development within her development plan). The paper brings forth a challenging concept along lines of a scientific research program that looks at the methodology of unity of knowledge as the phenomenological basis of development planning and then empirically investigates this methodological conception through modelling of ethics and values.

This paper aims to present a phenomenological and quantitative model to study the constitutive relations and working mechanism for shape/temperature memory effect in polypyrrole (PPy)-based shape memory polymers (SMPs).

In this paper, the origin of relaxation law was used to theoretically predict the relationships between relaxation time and internal energy and temperature based on the thermodynamics of polymers.

A phenomenological model was proposed to quantitatively identify the factors that influence the stored mechanical energy, shape memory effect (SME) and temperature memory effect (TME) in PPy. Both structural relaxation law and Tool-Narayanaswamy (TN) model were used to couple the constitutive relations of stress and transition temperature as a function of relaxation frequency, respectively. Furthermore, the simulation of the phenomenological model was compared with experimental results reported in relevant literature for purpose of verification.

Exploration of the working mechanism underpinning the experimental (or phenomenal) results and significant enhancement of the understanding of relevant experimental features reported previously.

The outcome of this study will provide a powerful phenomenological and quantitative tool for studies on SME and TME in SMPs.

The development of small firms tends to follow certain growth patterns usually referred to as business growth models. This paper reports on the conceptualisation of a “problem‐based phenomenological life cycle model”, which delineates the growth pattern of micro and small manufacturing firms in Cyprus. The empirically validated model offers guidance to small business managers, financiers and advisers as to the challenges and growth complexities accompanying the transitions taking place in small businesses as they develop along their organisational life cycle. Enhanced understanding of the barriers to the development of small business contributes to the better design of policy initiatives that seek to foster the survival, sustainable growth and prosperity of small enterprises.

The present study aims to resolve the adjustment problem of cavitation bubble number density in simulations of the cavitating flows within the diesel injection nozzle holes using a two-fluid cavitation model.

The basic rule that determines the variations of cavitation bubble number density has been checked through the scaling analysis of a two-fluid model under the assumption of hydrodynamic similarity of the cavitating flows. Moreover, a phenomenological model for the number density of cavitation bubbles that takes the hydrodynamic effect into account has been developed through the combined analysis of cavitation bubble dynamics and internal flow characteristics of diesel injection nozzle holes. This new model has also been validated by the discharge coefficient measures in a wide range of injection conditions.

The values of cavitation bubble number density must rationally match changes both in liquid quality effect and in hydrodynamic effect corresponding to different cavitating flows. The validation results show that the two-fluid cavitation model together with this new cavitation bubble number density model predicts well both the cavitation content inside the diesel nozzle hole and the relationship between discharge coefficient and cavitation number, and the new cavitation bubble number density model has the potential to further expand the application range of the two-fluid cavitation model.

This study provides insight into hydrodynamic effect corresponding to cavitating flows inside diesel nozzle holes and presents an idea to model the cavitation bubble number density phenomenologically. The model idea and the developed model are useful to researchers and engineers in the area of nozzle internal flow and cavitating flow.

This paper aims to present a phenomenological model to investigate the underlying mechanism and predict the bio-inspired performance under different thermo-temporal conditions.

Flory-Rehner free-energy functions are applied to quantitatively identify the driving forces in the viscously bio-inspired response of a dynamic polymer network. Furthermore, the permeation transition equation is adopted to couple water gradient and water sorption/desorption into the free-energy function.

The results show that the influence of potential energy on deformation can be related to a stretching ratio that uniquely determines water sorption/desorption, locomotion frequency and contractile stress. Finally, by means of combining the free-energy function and Arrhenius equation, a phenomenological thermo-temporal model is developed and verified by the experimental results.

This study focuses on exploring the theoretical mechanism and significantly enhances understanding of relevant experimental features reported previously.

The outcome of this study will provide a powerful phenomenological and quantitative tool for study on shape memory effect in bio-inspired polymers.

This paper is concerned with the performance of shell finite elements, well established in locking‐free computations with linear constitutive laws, in the case of non‐linear elastic material behaviour. Specifically enhanced strain elements are focused on. It is shown that the element behaviour depends on the resulting form of the stress tensor. Phenomenological models for highly non‐linear and elastically deforming rubber, like that of Odgen, are compared with the statistical‐based constitutive model developed by Arruda and Boyce. Whereas computations with the Odgen or any equivalent phenomenological model prove unstable, the behaviour of the enhanced elements, when the statistical model is applied, is shown to be superior. The behaviour is attributed to the mathematical form of the resulting stress tensor.