Configuration Mechanism Research Articles

Design and analysis of a multi-motion self-balancing lower limb exoskeleton based on flat terrain

In this study, a multi-motion self-balancing lower limb exoskeleton is designed to provide crutches-free rehabilitation training for quadriplegic patients on flat terrain without hand support. First, based on the biomechanical characteristics of the human body and the bionic mechanism configuration of the human lower limb, an exoskeleton with a full-drive series-parallel hybrid structure was established. Secondly, the D-H method, geometric method and Newton iteration method were used to establish the forward and reverse kinematic solutions of the exoskeleton. In addition, the static self-balancing principle was used to complete the planning of the multi-motion self-balancing trajectory. Finally, in order to verify the effectiveness of the proposed method, some numerical simulations were performed in this paper. The theoretical trajectories of the waist, ankle joint and foot center were compared with the simulated trajectories. The research results show that the forward and reverse kinematics model of the exoskeleton is feasible. Under the condition of contact force parameters, the exoskeleton has the ability of multi-motion self-balancing walking on flat terrain.

Intensified greenhouse gas prediction: Configuring Gate with Fine-Tuning Shifts with Bi-LSTM and GRU System

IntroductionOn a global scale, climate change refers to persistent alterations in weather conditions and temperature patterns. These modifications have far-reaching implications across the world. GHGs (Greenhouse Gases) play a crucial role in driving climate change. Most of these emissions originate from human activities, particularly those contributing to releasing CO2 and CH4. In the conventional approach, identifying emissions involves recognizing and quantifying the sources and amounts of GHG released into the atmosphere. However, this manual identification method has limitations, including being time-consuming, relying on incomplete resources, prone to human error, and lacking scalability and coverage.MethodologyTo address these challenges, a technology-based system is necessary for effectively identifying GHG emissions. The proposed method utilized the configuration of a gating mechanism incorporating fine-tuning shifts in the Bi-LSTM-GRU algorithm to predict GHG emissions in top-emitting countries. The PRIMAP-host dataset is used in the respective method comprising subsector data such as CO2, CH4, and N2O to attain this. In the presented model, Bi-LSTM is used to capture significant features, handle vanishing gradient problems, etc., because of its process in both directions. Conversely, it is limited by overfitting and long-term dependencies.Results and discussionGRU is used with Bi-LSTM to address the issue for the advantages of memory efficiency, handling long-term dependencies, rapid training process and minimizes the overfitting by infusion of GRU in the input layer of BiLSTM with tuning process in the BiLSTM. Here, the configuration of gates with fine-tuning shifts to improve the prediction performance. Moreover, the efficiency of the proposed method is calculated with performance metrics. Where RMSE value is 0.0288, MAPE is 0.0007, and the R-Square value is 0.99. In addition, internal and external comparisons are carried out to reveal the greater performance of the respective research.

Dynamic Analysis of Metamorphic Mechanisms with Impact Effects During Configuration Transformation

Metamorphic mechanisms have attracted considerable attention owing to their capability to switch their topology to adapt to different operational tasks. One feature of topological change is the re-contact of different bodies, which inevitably causes collisions affecting operation accuracy and service life. Consequently, in this study, a collision incidence matrix was introduced to describe the topology of a system involved in collisions, and a method for reducing the closed-loop system to an open-loop system was proposed. The complex movement of the metamorphic mechanism in a changing topology was classified into two different running stages of the source metamorphic mechanism. Based on the relative coordinate method, dynamic modeling of the source metamorphic mechanism considering the impact effects was conducted. Combining the classical collision theory and Newton–Euler equation, the generated impact impulse and the motion after collision were determined. Subsequently, a dynamic analytical method for the full configuration of metamorphic mechanisms was proposed to reflect the changes in the topological structure in the dynamic model. Finally, two typical metamorphic mechanisms used in packaging and spinning were considered as examples to verify the correctness and effectiveness of the proposed method, and their impact characteristics during configuration transformation were analyzed. The proposed analytical method of internal impact for a variable topology process provides effective theoretical guidance for the stability analysis of configuration transformation and structural design aimed at minimizing impacts.

Molecular insights into the binding mechanism of strontium and cesium on phyllosilicates with different expandability

The environmental fate of strontium (Sr) and cesium (Cs), as the critical radioactive fission products, have raised significant concerns regarding radioactive waste disposal and environmental protection. The current study investigated the distinction in the binding configurations of Sr2+ and Cs+ on various 2:1 phyllosilicate (illite, vermiculite, and montmorillonite) by combining batch adsorption, sequential extraction, and spectroscopic analyses. The results show that strontium adsorption is strongly influenced by pH as well as ionic strength, while there is no significant variability in strontium adsorption by different types of clay minerals. EXAFS analysis confirms the outer complexation of strontium on the planar sites of the clay minerals, i.e., Sr2+ is surrounded by ~8.0 O atoms, RSr-O ≈ 2.6 Å, and that process is mainly realized by ion exchange. In contrast, Cs+ adsorption was markedly influenced by the variety of clay minerals but less by pH and ionic strength, the presence of humic acid (HA) inhibited Cs+ adsorption. The inner-sphere complexation formed mainly at the frayed edge sites on illite, and interlayer sites on vermiculite and montmorillonite, was the dominant mechanism for Cs+ adsorption. In addition, the collapse of the interlayer space of vermiculite induced by Cs+ adsorption on the interlayer sites was responsible for the more stable and irreversible immobilization. The findings in present work highlighted the significance of prevailed mineral in governing environmental migration risk of radionuclides, the revealed adsorption mechanism and binding configuration of Sr2+ and Cs+ on typical phyllosilicates would be referable in constructing a reliable migration model of Sr2+ and Cs+ in natural media.

Health visiting in the UK in light of the COVID-19 pandemic experience: (RReHOPE) findings from a realist review.

Child health programmes in the United Kingdom offer every child and their family an evidence-based programme to support child health and development. During the COVID-19 pandemic, health visiting services in many areas were reduced to a partial service, with significant variability between and within the four United Kingdom countries. This study investigated the impact of the pandemic on health visiting services and developed recommendations for policy and practice. Conduct a realist review of relevant literature. Engage with key stakeholders in policy, practice and research across the United Kingdom. Identify recommendations for improving the organisation and delivery of health visiting services, with a focus on services being equitable, effective and efficient. The realist review followed Pawson's five iterative steps and involved key stakeholder representatives at every step. We searched five electronic databases and references of included articles, as well as relevant organisational websites, to find quantitative, qualitative, mixed-methods and grey literature related to health visiting services in the United Kingdom during the COVID-19 pandemic. An assessment of their relevance to our initial programme theory determined inclusion in the review. Data were extracted, organised and presented as draft context, mechanism and outcome configurations. These were iteratively refined through meetings with 6 people with lived experience of caring for babies during the pandemic and 23 professional stakeholders. Context, mechanism and outcome configurations were then translated into findings and recommendations. One hundred and eighteen documents contributed to the review and collectively revealed the far-reaching, uneven and enduring impact of the COVID-19 pandemic on babies and families. Data uncovered significant concerns of families and practitioners amidst the pandemic, along with the service's corresponding actions. These concerns and responses underscored the critical importance of fostering and sustaining trusting relationships between health visitors and families, as well as conducting holistic assessments for early intervention. Although we found minimal evidence of decision-making within organisational/managerial levels, the data illustrated the diverse and complex nature of health visiting work and the need for flexibility and resourcefulness. The primary limitation of this review was a lack of specific evidence from the United Kingdom nations other than England. There was also a lack of data focusing on changes during the COVID-19 pandemic at a local management level. The needs of babies, children and families, and the delivery of services to support them, were not prioritised in the early phase of the pandemic response. Our data show that the health visiting service was concerned with maintaining visibility of all children, and especially supporting families with a new baby. Health visiting services adapted in numerous ways to respond to these concerns. Implications for policy and practice are presented, identified from our analysis and discussions with stakeholders. The RReHOPE study is part of a jigsaw of evidence, which will provide a much stronger evidence base for future policy and practice. This realist review presents several areas for future research, including how health visiting is organised at local management level; how to optimise limited resources; factors affecting differing uptake in different regions; and analysis of the effectiveness of health visiting using large cohort studies. This article presents independent research funded by the National Institute for Health and Care Research (NIHR) Health and Social Care Delivery Research programme under award number NIHR134986.

Lifestyle approaches to hypertension for prevention of stroke and vascular cognitive impairment: a realist review protocol

IntroductionStroke and vascular cognitive impairment (VCI) are major global public health pandemics. The increased incidence of stroke and VCI is in part due to modifiable risk factors (MRFs), with hypertension...

Mental health stigma and health-seeking behaviors amongst pregnant women in Vietnam: a mixed-method realist study

BackgroundApproximately 15% of women in low-and middle-income countries experience common perinatal mental disorders. Yet, many women, even if diagnosed with mental health conditions, are untreated due to poor quality care, limited accessibility, limited knowledge, and stigma. This paper describes how mental health-related stigma influences pregnant women’s decisions not to disclose their conditions and to seek treatment in Vietnam, all of which exacerbate inequitable access to maternal mental healthcare.MethodsA mixed-method realist study was conducted, comprising 22 in-depth interviews, four focus group discussions (total participants n = 44), and a self-administered questionnaire completed by 639 pregnant women. A parallel convergent model for mixed methods analysis was employed. Data were analyzed using the realist logic of analysis, an iterative process aimed at refining identified theories. Survey data underwent analysis using SPSS 22 and descriptive analysis. Qualitative data were analyzed using configurations of context, mechanisms, and outcomes to elucidate causal links and provide explanations for complexity.ResultsNearly half of pregnant women (43.5%) would try to hide their mental health issues and 38.3% avoid having help from a mental health professional, highlighting the substantial extent of stigma affecting health-seeking and accessing care. Four key areas highlight the role of stigma in maternal mental health: fear and stigmatizing language contribute to the concealment of mental illness, rendering it unnoticed; unconsciousness, normalization, and low literacy of maternal mental health; shame, household structure and gender roles during pregnancy; and the interplay of regulations, referral pathways, and access to mental health support services further compounds the challenges.ConclusionAddressing mental health-related stigma could influence the decision of disclosure and health-seeking behaviors, which could in turn improve responsiveness of the local health system to the needs of pregnant women with mental health needs, by offering prompt attention, a wide range of choices, and improved communication. Potential interventions to decrease stigma and improve access to mental healthcare for pregnant women in Vietnam should target structural and organizational levels and may include improvements in screening and referrals for perinatal mental care screening, thus preventing complications.

DETERMINATION OF LOAD CHARACTERISTICS OF A LINEAR ELECTROMECHANICAL ENERGY CONVERTER FOR THE TILT SYSTEM OF RAILWAY ROLLING STOCK

The article discusses the prerequisites for selecting the parameters of a Linear Electromechanical Energy Converter (LEEC) for the tilt system of railway rolling stock. Special attention is given to determining the required force to tilt the body to a specified angle and the load characteristics of the LEEC. To achieve this goal, a simulation model has been created that allows for the variation of geometric and physical parameters to obtain load characteristics for different configurations of the tilt mechanism. The obtained load characteristics are used to find the optimal placement of linear actuators in the tilt system.

Low-carbon optimal scheduling of an integrated electricity, heat-and-gas energy system considering a biomass gas and carbon capture power plant

Abstract In light of enhancing the extraction level of biomass energy and rectifying the efficiency of integrated energy system (IES) operations in the backdrop of the “ twin carbon” policy, we present an enhanced scheduling methodology for IES incorporating biomass gas and carbon absorption power plants, addressing the constraints of linear carbon trading. Initially, an organizational blueprint for the combined exploitation of biomass-laden gas, electricity-to-gas, and carbon absorption power plants is established. Secondly, we devise a ladder-like configuration of carbon trading mechanisms to counterbalance the inadequacies of standard persistent carbon trading schemes. Subsequently, this advanced form of carbon trading is incorporated into the IES framework and is optimized using the ultimate goal of minimizing system expenditures. Lastly, evaluations across diverse scenarios demonstrate that the proposed sequential carbon trading significantly enhances the economic viability of the system, and the accompanying simulation corroborates the validity of our proposed model.

Type synthesis of 3-DOF spherical hybrid mechanisms with fixed centers of rotation

To improve the load-bearing capacity and the rotation range about the normal of the moving platform in a spherical parallel mechanism (SPM), a type synthesis method for spherical hybrid mechanisms (SHMs) with fixed centers of rotation is proposed by coupling a serial transmission chain with the central passive limb chain of the SPM near its center area. Based on the analysis of the spherical mechanism configuration’s research status with a fixed rotation center, a method for systematically synthesizing SHMs is given, and four types of limb chains are developed. The possible limb constraint systems provided by each type of limb chain are analyzed via screw theory, and the type synthesis of each type of limb chain is carried out. Screening rules are proposed to obtain the preferred limb chains from the limb chain configuration results. By selecting and permuting preferred limb chains based on the mechanism’s center position of rotation and the constraint type, a series of SHMs that rotate unrestricted about the normal of the moving platform are produced. Selecting the RBR-2RRR SHM as an example, its workspace, singularity, dexterity, and stiffness are analyzed to verify the effectiveness of the research. This work enriches the configuration types of SHMs and provides theoretical support for the design and applications of SHMs in engineering.

A realist evaluation protocol: assessing the effectiveness of a rapid response team model for mental state deterioration in acute hospitals.

Mental state deterioration poses significant challenges in healthcare, impacting patients and providers. Symptoms like confusion and agitation can lead to prolonged hospital stays, increased costs, and the use of restrictive interventions. Despite its prevalence, there's a lack of consensus on effective practices for managing mental state deterioration in acute hospital settings. To address this gap, a rapid response team model has been proposed as a potential intervention, aiming to provide early identification and targeted interventions. Based on realist evaluation steps, first, initial program theories are formulated to understand the logic behind the intervention. Second, literature synthesis identifies empirical evidence on contexts, mechanisms, and outcomes elements, refining initial theories. During the third step, data will be collected using qualitative methods such as field observations and interviews, as well as quantitative methods such as surveys of the staff, audits of electronic medical records, and analysis of incident records of mental state deterioration. Analysing this data informs configurations of contexts, mechanisms, and outcomes. In the fifth step, the configurations are synthesised, presenting refined, evidence-informed program theories. This study addresses the knowledge gap by evaluating the rapid response model's effectiveness in managing mental state deterioration in acute hospital settings. Realist principles guide the exploration of causal mechanisms and their interaction with specific implementation contexts. The objective is to identify what works, for whom, and under what circumstances, aiming to manage deterioration, reduce restrictive interventions, and enhance the experience for patients and staff by implementing a proactive model of care. The findings contribute to evidence-based approaches for managing mental state deterioration in hospital settings, informing policy and practice in this crucial area of healthcare.

Design and performance analysis of the 4UPS-RRR parallel ankle rehabilitation mechanism

Abstract. Ankle sprains are among the most common musculoskeletal injuries. Patients often require systematic rehabilitation training to expedite tissue healing and facilitate joint recovery. However, such training places high demands on medical staff, involves a lengthy process, requires considerable labor, and suffers from a shortage of skilled rehabilitation personnel. To address the need for effective ankle joint dysfunction rehabilitation training, this study analyzes the bone structure and movement mechanism of the ankle. Drawing on the parallel mechanism configuration, we propose a 4UPS-RRR parallel ankle rehabilitation mechanism. The rotation center of the rehabilitation mechanism can be highly coincident with the rotation center of the human ankle joint. The structure and degrees of freedom of the mechanism were designed and analyzed using screw theory. Additionally, a kinematic model of the mechanism was established. The mechanism's workspace was mapped by constraining the linear actuator length and spherical joint rotation angle. Furthermore, the mechanism's dexterity was assessed through the establishment of its Jacobian matrix, with the correctness of the kinematic model verified through simulation. Finally, an experimental platform was utilized to test the maximum range of robot motion, confirming the practicality of the ankle rehabilitation mechanism.

Differential Privacy-Preserving IoT Data Sharing Through Enhanced PSO

ABSTRACT With the proliferation of Internet of Things (IoT) devices and the generation of massive amounts of sensitive data, preserving privacy while enabling data sharing has become a critical concern. In this research, we propose a novel approach for achieving differential privacy in IoT data sharing through an improved Particle Swarm Optimization (PSO) algorithm. Our objective is to find the optimal configuration of privacy-preserving mechanisms that maximizes privacy while maintaining data utility. The research begins with a comprehensive overview of differential privacy in IoT data sharing, highlighting the limitations of existing optimization algorithms. We then present our proposed improvements to the traditional PSO algorithm, including the design of a suitable fitness function, the use of a dynamic inertia weight, exploration of different neighborhood topologies, and adaptive acceleration coefficients. We define a set of performance metrics, including privacy metrics (e.g. ε-differential privacy parameter) and utility measures (e.g. accuracy, utility loss), to assess the algorithm’s effectiveness. The results of our experiments demonstrate that the improved PSO algorithm achieves higher privacy guarantees while maintaining competitive levels of data utility compared to existing approaches. The proposed algorithm exhibits faster convergence, better exploration of the search space, and improved scalability. Our research contributes to the field of privacy-preserving IoT data sharing by providing an efficient and effective optimization algorithm that enables secure and privacy-aware data sharing while facilitating valuable insights and analysis.

Dynamic model of single-DOF spherical mechanisms based on instantaneous pole axes and Eksergian's equation

Instantaneous pole axes (IPAs) fully describe instantaneous kinematics of spherical mechanisms. In single-degree-of-freedom (single-DOF) mechanisms, IPAs’ locations uniquely depend on the mechanism configuration. Such a property allows the deduction of instantaneous-motion characteristics by means of analytic techniques based on geometric features of the mechanism configuration. Moreover, these geometric/analytic approaches are extendable to mechanism's static analyses since the virtual work principle relates mechanism's statics to its instantaneous kinematics. Analytic approaches based on geometric reasoning are of interest in mechanism design and their further extension to dynamic analyses is appealing in that context. This work proposes a possible extension of IPA-based techniques to dynamic analyses of single-DOF spherical mechanisms by using Eksergian's equation. A novel general dynamic model for single-DOF spherical mechanisms is proposed, which is based on IPAs’ locations. Then, the effectiveness of the proposed model is applied to a relevant single-DOF spherical mechanism.

Trusting the trust machine: How does blockchain-enabled governance configuration enhance financing credibility?

This study highlights the role of blockchain technology in addressing the trust crisis in supply chain operations and financial activities. While previous research has acknowledged blockchain as a response to trust issues, limited studies have explored its specific contributions and its impact on accelerating cash flow in supply chains. Drawing on governance theory, this study investigates the relationship between blockchain technology and supply chain finance (SCF) through multiple case studies. The central argument is that blockchain technology alone does not automatically generate trust. Instead, trust is established through the configuration of various governance mechanisms. We propose that trust in blockchain applications is derived from two main factors: the requirement of codifiability and verifiability. Through a cross-case analysis, we found that in situations where both the requirement of codifiability and verifiability are high, blockchain governance tends to dominate. When only one factor is high, a configuration of blockchain governance and relational governance emerges. When both factors are low, contractual governance proves to be efficient. This study underscores the need for a nuanced understanding of trust dynamics in blockchain applications and highlights the importance of considering contextual factors in trust research related to blockchain technology.

Enhanced X-ray free-electron laser performance with optical klystron and helical undulators.

This article presents a demonstration of the improved performance of an X-ray free-electron laser (FEL) using the optical klystron mechanism and helical undulator configuration, in comparison with the common planar undulator configuration without optical klystron. The demonstration was carried out at Athos, the soft X-ray beamline of SwissFEL. Athos has variable-polarization undulators, and small magnetic chicanes placed between every two undulators to fully exploit the optical klystron. It was found that, for wavelengths of 1.24 nm and 3.10 nm, the required length to achieve FEL saturation is reduced by about 35% when using both the optical klystron and helical undulators, with each effect accounting for about half of the improvement. Moreover, it is shown that a helical undulator configuration provides a 20% to 50% higher pulse energy than planar undulators. This work represents an important step towards more compact and high-power FELs, rendering this key technology more efficient, affordable and accessible to the scientific community.

Tree-type hybrid mechanism configuration synthesis based on modular decomposition and power-concentrated joint closed-loop design

Mechanisms with multiple end-effectors are widely used in engineering due to their ability to synchronize and collaborate on multiple processes. However, this kind of mechanism is difficult to design due to its high topological complexity and complex applied loads. In order to solve this problem, this article proposes a configuration synthesis method for tree-type hybrid mechanisms from two aspects: modular decomposition of open-loop mechanisms and closed-loop design of power-concentrated joints. According to the correlation of the space of degrees of freedom between the end-effector, the mechanism is decomposed into different modules for hierarchical design to simplify the mechanism structure. The unit power concentration index is utilized to find the joints where the power output is relatively concentrated and replace them with low-complexity single-degree-of-freedom closed-loop structures to improve the structural stiffness and dynamic performance of the mechanism. Finally, the feasibility of the proposed method is verified by taking a steel arch looping mechanism with four end-effectors as an example. The aim of this article is to design a simple and reliable multi-branch mechanism with high load carrying capacity to make it more adaptable to the complex and harsh operating environment, which can provide a reference for the design of similar engineering equipment.

Corporate governance for sustainable development: A study on mechanism configuration

There is a dearth of configuration analysis on the factors that constitute corporate governance mechanisms within the framework of corporate sustainable goals in existing literature. Specifically, the impact mechanisms related to various combined mechanisms have not been comprehensively defined. This study employs Qualitative Comparative Analysis (QCA) approach to explore the effects of various configurations of corporate governance mechanisms on sustainable development, based on a sample of 2959 Chinese listed companies. Our analysis identifies four distinct pathways that facilitate the achievement of sustainable development goals: 1) enlarging board size, providing managerial incentives, establishing sustainability committees, and enhancing corporate transparency; 2) promoting board diversity, providing managerial incentives, establishing sustainability committees, and enhancing corporate transparency; 3) reducing ownership concentration, providing managerial incentives, establishing sustainability committees, and enhancing corporate transparency; 4) encouraging individual investment, providing managerial incentives, establishing sustainability committees, and enhancing corporate transparency. Additionally, a comparative analysis of different pathways has revealed substitutional relationships between board size and diversity, ownership concentration and investor structure, while highlighting the complementary relationship of managerial incentives, sustainability committees, and corporate transparency. Challenging the erstwhile linear research paradigm, this study contributes to understanding the pathways for achieving sustainable development goals from a configurational perspective and elucidates the relationships between corporate governance mechanisms. It offers novel and comprehensive evidence for examining the intricate nexus between corporate governance mechanisms and sustainable development. Keywords: Stakeholder theory; Sustainable development; Corporate governance mechanisms; Mechanism configurations; fuzzy-set Qualitative Comparative Analysis (fsQCA).

Resource-Efficient Multicast URLLC Service in 5G Systems.

Many emerging applications, such as factory automation, electric power distribution, and intelligent transportation systems, require multicast Ultra-Reliable Low-Latency Communications (mURLLC). Since 3GPP Release 17, 5G systems natively support multicast functionality, including multicast Hybrid Automatic Repeat Request and various feedback schemes. Although these features can be promising for mURLLC, the specifications and existing studies fall short in offering guidance on their efficient usage. This paper presents the first comprehensive system-level evaluation of mURLLC, leveraging insights from 3GPP specifications. It points out (i) how mURLLC differs from traditional multicast broadband wireless communications, and (ii) which approaches to provide mURLLC require changing the paradigm compared with the existing solutions. Finally, the paper provides recommendations on how to satisfy strict mURLLC requirements efficiently, i.e., with low channel resource consumption, which increases the capacity of 5G systems for mURLLC. Simulation results show that proper configuration of multicast mechanisms and the corresponding algorithms for mURLLC traffic can reduce resource consumption up to three times compared to the baseline solutions proposed for broadband multicast traffic, which significantly increases the system capacity.

Effect of short video storytelling on festival attractiveness: the moderating role of temporal orientation and novelty

ABSTRACT Short video storytelling has become an important channel for destination marketing. However, how to take advantage of short video storytelling to enhance festival attractiveness is unclear. Based on narrative transportation theory, this study analysed 494 questionnaires through the hybrid exploration method of structural equation model (SEM) and fuzzy-set qualitative comparative analysis (fsQCA), to deeply explore the mechanism and conditional configuration of short video storytelling affecting festival attractiveness. The findings reveal that the effect of short video storytelling on festival attractiveness is significant, and partly mediated by narrative transportation. Moreover, compared with future-oriented people, present-oriented people are more likely to immerse themselves in short video storytelling and be attracted by festivals. Additionally, novelty, a core condition for high festival attractiveness, significantly strengthens the effects of storytelling and narrative transportation on attractiveness. Overall, this study expands the theoretical knowledge of short video storytelling in festival marketing and supports destination managers to formulate effective short video marketing strategies for destination festivals.