Shuai Deng, Xin Cheng, Huachun Wu and Yefa Hu
The multi-objective optimization configuration strategy is proposed due to the configuration of EMAs in fault-tolerant control of active magnetic bearing with redundant…
Abstract
Purpose
The multi-objective optimization configuration strategy is proposed due to the configuration of EMAs in fault-tolerant control of active magnetic bearing with redundant electromagnetic actuators involving high-dimensional, nonlinear, conflicting goals.
Design/methodology/approach
A multi-objective optimization model for bias current coefficients is established based on the nonlinear model of active magnetic bearings with redundant electromagnetic actuators. Based on the non-dominated sorting genetic algorithm III, a numerical method is used to obtain feasible and non-inferior sets for the bias current coefficient.
Findings
(1) The conflicting relationship among the three optimization objectives was analyzed for various failure modes of EAMs. (2) For different EMAs' failure modes, the multi-objective optimization configuration strategy can simultaneously achieve the optimal or sub-optimal effective EMF, flux margins, and stability of EMF. Moreover, the characteristics of the optimal Pareto front are consistent with the physical properties of the AMB. (3) Compared with the feasible configuration of C0, the non-inferior configurations can significantly improve the performance of AMB, and the advantages of the multi-objective optimization configuration strategy become more prominent as the asymmetry of the residual supporting structure intensifies.
Originality/value
i) Considering the variation of the rotor displacement during the support reconstruction, a decision-making model that can accurately characterize the dynamic performance of AMB is presented. (ii) The interaction law between AMB and rotor under different failure modes of EMAs is analyzed, and the configuration principles for redundant EMAs are proposed. (iii) Based on the dynamic characteristics of AMB during the support reconstruction, effective EMF, energy consumption, and the Pearson correlation coefficient between the desired EMFs and the decoupled control currents are used as objective functions. iv. The NSGA-III is combined with the decision-making model to address the multi-objective optimization configuration problem of C0.
Details
Keywords
Qingying Wang, Rongjun Cheng and Hongxia Ge
The purpose of this paper is to explore how curved road and lane-changing rates affect the stability of traffic flow.
Abstract
Purpose
The purpose of this paper is to explore how curved road and lane-changing rates affect the stability of traffic flow.
Design/methodology/approach
An extended two-lane lattice hydrodynamic model on a curved road accounting for the empirical lane-changing rate is presented. The linear analysis of the new model is discussed, the stability condition and the neutral stability condition are obtained. Also, the mKdV equation and its solution are proposed through nonlinear analysis, which discusses the stability of the extended model in the unstable region. Furthermore, the results of theoretical analysis are verified by numerical simulation.
Findings
The empirical lane-changing rate on a curved road is an important factor, which can alleviate traffic congestion.
Research limitations/implications
This paper does not take into account the factors such as slope, the drivers’ characters and so on in the actual traffic, which will have more or less influence on the stability of traffic flow, so there is still a certain gap with the real traffic environment.
Originality/value
The curved road and empirical lane-changing rate are researched simultaneously in a two-lane lattice hydrodynamic models in this paper. The improved model can better reflect the actual traffic, which can also provide a theoretical reference for the actual traffic governance.
Details
Keywords
This paper gives a review of the finite element techniques (FE) applied in the area of material processing. The latest trends in metal forming, non‐metal forming, powder…
Abstract
This paper gives a review of the finite element techniques (FE) applied in the area of material processing. The latest trends in metal forming, non‐metal forming, powder metallurgy and composite material processing are briefly discussed. The range of applications of finite elements on these subjects is extremely wide and cannot be presented in a single paper; therefore the aim of the paper is to give FE researchers/users only an encyclopaedic view of the different possibilities that exist today in the various fields mentioned above. An appendix included at the end of the paper presents a bibliography on finite element applications in material processing for 1994‐1996, where 1,370 references are listed. This bibliography is an updating of the paper written by Brannberg and Mackerle which has been published in Engineering Computations, Vol. 11 No. 5, 1994, pp. 413‐55.
Details
Keywords
Vu Hong Son Pham and Duy Hieu Pham
This study aims to optimize the construction site layout planning (CSLP) problem, with a focus on prefabricated projects. It proposes the use of the oMOAHA algorithm, an enhanced…
Abstract
Purpose
This study aims to optimize the construction site layout planning (CSLP) problem, with a focus on prefabricated projects. It proposes the use of the oMOAHA algorithm, an enhanced version of the multi-objective artificial hummingbird algorithm (MOAHA), to address challenges related to search space exploration and local optimization in CSLP.
Design/methodology/approach
The study integrates three techniques – opposition-based learning (OBL), quasi-opposition and quasi-reflection – into the initialization phase of the MOAHA algorithm, creating the oMOAHA variant. This model is applied to all three types of CSLP problems – pre-determined location, grid system and continuous space – to evaluate its effectiveness. Six objective functions (three related to cost, two to safety and one to tower crane efficiency) and four site-related constraints are considered through three case studies taken from previous research and one real project involving prefabricated steel structures.
Findings
The oMOAHA algorithm demonstrates superior performance compared to previous models, consistently outperforming traditional approaches in CSLP optimization for prefabricated projects. In the real case study, the proposed model exceeded the actual project plan by 28–43%, indicating its potential to significantly improve both solution quality and project outcomes.
Originality/value
This study is the first to apply an optimization model to all three types of CSLP problems – pre-determined location, grid system and continuous space – within a unified framework. The integration of advanced techniques into the MOAHA algorithm and the model’s successful application in a real prefabricated project underscore its high applicability and effectiveness in modern construction management.
Details
Keywords
Ying Yang, Wei Wu, Xuequn Cheng, Jinbin Zhao, Baijie Zhaoal and Xiaogang Li
This study aims to develops a new-type low-alloy corrosion resistant steel containing Sb and investigate the corrosion mechanism of this new-type low-alloy steel.
Abstract
Purpose
This study aims to develops a new-type low-alloy corrosion resistant steel containing Sb and investigate the corrosion mechanism of this new-type low-alloy steel.
Design/methodology/approach
Energy dispersive spectrometer, X-ray photoelectron spectroscopy, X-Ray diffraction and scanning electron microscopy were used to evaluate the corrosion resistance of the rust layers formed on these samples. Laser confocal microscopy was used to observe the corroded surfaces of the steels.
Findings
Results showed that Sb added can consume H+ in the solution, thereby preventing the oxygen reaction to slow down the corrosion rate. Meanwhile, a stable and insoluble substance (Sb2O3) in the acidic solution would be produced when the reaction of the product of Sb and H+ with the enough dissolved oxygen in the solution. Due to the precipitation of Sb2O3 and iron oxyhydroxides, the rust layer of Sb-containing steel became more uniform and compact, which resulted in better corrosion resistance in acid environment.
Originality/value
In this study, a new-type acid resistant low-alloy steel containing Sb was developed. Compared with the results, the corrosion mechanism of the new-type low-alloy steel in acid environment was discussed.
Details
Keywords
Sandang Guo, Liuzhen Guan, Qian Li and Jing Jia
Considering the bounded confidence of decision-makers (DMs), a new grey multi-criteria group consensus decision-making (GMCGCDM) model is established by using interval grey number…
Abstract
Purpose
Considering the bounded confidence of decision-makers (DMs), a new grey multi-criteria group consensus decision-making (GMCGCDM) model is established by using interval grey number (IGN), cobweb model, social network analysis (SNA) and consensus reaching process (CPR).
Design/methodology/approach
Firstly, the model analyzes the social relationship of DM under social networks and proposes a calculation method for DMs’ weights based on SNA. Secondly, the model defines a cobweb model to consider the preferences of decision-making alternatives in the decision-making process. The consensus degree is calculated by the area surrounded by the connections between each index value of DMs and the group. Then, the model coordinates the different opinions of various DMs to reduce the degree of bias of each DM and designs a consensus feedback mechanism based on bounded confidence to guide DMs to reach consensus.
Findings
The advantage of the proposed method is to highlight the practical application, taking the selection of low-carbon suppliers in the context of dual carbon as an example. Comparison analysis is performed to reveal the interpretability and applicability of the method.
Originality/value
The main contribution of this paper is to propose a new GMCGCDM model, which can not only expand the calculation method of DM’s weight and consensus degree but also reduce the time and cost of decision-making.
Details
Keywords
The purpose of this paper is to study the electrochemical behavior of 690 alloy with corrosion products in simulated pressurized water reactor (PWR) primary water environment.
Abstract
Purpose
The purpose of this paper is to study the electrochemical behavior of 690 alloy with corrosion products in simulated pressurized water reactor (PWR) primary water environment.
Design/methodology/approach
This paper opted for a laboratory study using simulation of high temperature and high pressure environment immersion testing. The electrochemical behavior was studied by potentiodynamic polarization, electrochemical impedance spectroscopy, scanning Kelvin probe microscopy (SKP). Moreover, the corrosion products were analyzed by X-ray photoelectron spectroscopy.
Findings
The results demonstrated that the particle majority in the 690 alloy corrosion products subsequent to high temperature and high pressure immersion testing were mainly oxides of Fe and Ni, which protected the matrix. As the immersion testing duration increased, the corrosion potential of the 690 alloy apparently increased, and the corrosion current density de'creased, while the corrosion resistance Rf increased gradually along with the density. The SKP demonstrated that the EKP increased by nearly 400 mV from −0.42 to −0.03 V following the immersion testing, indicating that the corrosion product film played an apparent protective role on the substrate.
Originality/value
This paper provides a theoretical basis for the corrosion behavior and inhibition mechanism of 690 alloy in PWR primary water environment.
Details
Keywords
Lolita Alfred, Mark Limmer and Susan Cartwright
Alcohol workplace policies (AWPs) can help organizations to manage and support employees with alcohol-related problems. Over the last two decades, there has been a slow but steady…
Abstract
Purpose
Alcohol workplace policies (AWPs) can help organizations to manage and support employees with alcohol-related problems. Over the last two decades, there has been a slow but steady rise of research on AWPs with some indication that these can contribute to reducing employee excessive consumption. However, there does not appear to be any empirical literature reviews to consolidate and evaluate what this body of evidence says regarding the impact of these policies. The following review seeks to address this gap.
Design/methodology/approach
Five electronic databases were searched for papers published between January 1996 and January 2020. To capture additional relevant papers (including those from non-peer reviewed sources), the search was extended to Google Scholar, professional and human resource management websites, trade publications and the website of one United Kingdom (UK)-based alcohol charity. Inclusion and exclusion criteria were used to systematically screen the paper titles, abstracts and full-text records. 14 papers were deemed eligible and therefore included in the integrative review. After extracting data, all 14 papers were appraised for quality and then analysed using the narrative synthesis guide by Popay et al. (2006).
Findings
Five themes were identified, namely, Associations between Policy and Consumption Levels/Patterns, Deterrence, Policy and Programme Type, Knowledge and Understanding and Enforcement and Discipline. These themes encapsulated what the included papers concluded about the impact and associated benefits or challenges of AWPs.
Research limitations/implications
This review identifies that despite the benefits of AWPs, up to 40% of workplaces do not have these policies in place. Future research needs to explicitly explore the reasons for this.
Practical implications
This review highlights that AWPs can benefit employees and workplaces. Therefore, organizations are encouraged to develop and implement AWPs to support health improvement and prevention of alcohol problems in the workplace.
Originality/value
This review provides a current synthesis of literature published over the last two decades regarding the impact of AWPs on employees and workplaces.
Details
Keywords
In line with the fast development of information technology, the Internet of Medical Robotic Things (IoMRT) is gaining more ground in health care. Sharing patients' information…
Abstract
Purpose
In line with the fast development of information technology, the Internet of Medical Robotic Things (IoMRT) is gaining more ground in health care. Sharing patients' information effectively and securely can improve sensing data usage and confidentiality. Nevertheless, current IoMRT data sharing schemes are lacking in terms of supporting efficient forward secrecy; when secret key for a robotic nurse as a data requester is compromised, all the historically shared data with this robotic nurse will be leaked.
Design/methodology/approach
The presented paper suggests an efficient puncturable attribute-based data sharing scheme enabling guaranteed firm security and versatile access control over health sensing data in IoMRT. This scheme integrates attribute-based and puncturable encryption to avail a shared secret key for data sharing that can be encrypted by an access structure over the Data Requester (DR) attributes. Additionally, the establishment of the shared key and the mutual authentication is simultaneously done between the cloud servers and DRs.
Findings
The proposed scheme can achieve forward secrecy by adopting the bloom filter technique that efficiently helps the updating of a private key with no need for the key distributor to reissue the key. The security proof illustrates that this scheme adheres to the security model. Besides, the performance evaluation expresses the feasibility of the suggested scheme.
Originality/value
The main goal of designing a puncture algorithm is to devise an updated key from the ciphertext and a secret key, allowing the decryption of all ciphertexts except the one that has been punctured on. This research illustrates the first effort to develop a puncturable attribute-based encryption scheme to achieve efficient finegrained data sharing in IoMRT.
Details
Keywords
Jianchun Sun, Shiyong Yang, Shengping Huang, Zhijiang Shang and Weihao Ling
This paper addresses the issue of internal spatial environmental pollution in non-blasting tunnel construction by proposing a comprehensive evaluation model. The model aims to…
Abstract
Purpose
This paper addresses the issue of internal spatial environmental pollution in non-blasting tunnel construction by proposing a comprehensive evaluation model. The model aims to provide a scientific basis for environmental pollution prevention in non-blasting tunnel construction, thereby facilitating green tunnel construction and sustainable development management.
Design/methodology/approach
The study firstly refines and constructs the evaluation index system from the perspective of pollution sources. A novel weight calculation method is introduced by integrating the analytic hierarchy process (AHP) with the ordered weighted averaging (OWA) operator, and a comprehensive evaluation model for internal environmental pollution in non-blasting tunnels is established by incorporating the grey clustering evaluation method. Finally, an empirical study is conducted using the Erbaoshan Tunnel as a case study to verify the feasibility and effectiveness of the model.
Findings
The study develops an evaluation system for internal environmental pollution in non-blasting tunnels and applies it to the Erbaoshan Tunnel. The results classify the pollution level as “general pollution,” confirming the rationality and applicability of the evaluation system and model while also identifying the primary pollution factors.
Originality/value
This study first developed a comprehensive evaluation system for environmental pollution in non-blasting tunnel construction from the pollution source perspective, making the system more comprehensive. Additionally, it innovatively combined AHP–OWA and gray clustering methods to scientifically assess pollution levels, providing valuable scientific guidance for the evaluation and management of non-blasting tunnels and similar underground projects.