Xin Chen, Xiaoyu Zheng, Meiling He, Yuling Liu, Hong Mao, Xiwu Li, Hongwei Yan, Yi Kong, Liya Li and Yong Du
During the forming process, aluminum alloy sheets develop various types of textures and are subjected to cyclic loading as structural components, resulting in fatigue damage. This…
Abstract
Purpose
During the forming process, aluminum alloy sheets develop various types of textures and are subjected to cyclic loading as structural components, resulting in fatigue damage. This study aims to develop polycrystalline models with different orientation distributions and incorporate suitable fatigue indicator parameters to investigate the effect of orientation distribution on the mechanical properties of Al-7.02Mg-1.78Zn alloys under cyclic loading.
Design/methodology/approach
In this study, a two-dimensional polycrystalline model with 150 equiaxed grains was constructed based on optical microscope images. Subsequently, six different orientation distributions were assigned to this model. The fatigue indicator parameter of strain energy dissipation is utilized to analyze the stress response and fatigue crack driving force in polycrystalline models with different orientation distributions subjected to cyclic loading.
Findings
The study found that orientation distribution significantly influences fatigue crack initiation. Orientation distributions with a larger average Schmid factor exhibit reduced stress response and lower fatigue indicator parameters. Locations with a larger average Schmid factor experience greater plastic deformation and present a higher risk for fatigue crack initiation. RVE with a single orientation undergoes more rotation to reach cyclic steady state under cyclic loading due to the ease of deformation transfer.
Originality/value
Currently, there are no reports in the literature on the calculation of fatigue crack initiation for Al-Mg-Zn alloys using the crystal plasticity finite element method. This study presents a novel strategy for simulating the response of Al-7.02Mg-1.78Zn materials with different orientation distributions under symmetric strain cyclic loading, providing valuable references for future research.
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Yan Xia, Yi Wan, Hongwei Wang and Zhanqiang Liu
As the transmission component of a locomotive, the traction gear pair system has a direct effect on the stability and reliability of the whole machine. This paper aims to provide…
Abstract
Purpose
As the transmission component of a locomotive, the traction gear pair system has a direct effect on the stability and reliability of the whole machine. This paper aims to provide a detailed dynamic analysis for the traction system under internal and external excitations by numerical simulation.
Design/methodology/approach
A non-linear dynamic model of locomotive traction gear pair system is proposed, where the comprehensive time-varying meshing stiffness is obtained through the Ishikawa formula method and verified by the energy method, and then the sliding friction excitation is analyzed based on the location of the contact line. Meantime, the adhesion torque is constructed as a function of the adhesion-slip feature between wheelset and rail. Through Runge–Kutta numerical method, the system responses are studied with varying bifurcation parameters consisting of exciting frequency, load fluctuation, gear backlash, error fluctuation and friction coefficient. The dynamic behaviors of the system are analyzed and discussed from bifurcation diagram, time history, spectrum plot, phase portrait, Poincaré map and three-dimensional frequency spectrum.
Findings
The analysis results reveal that as control parameters vary the system experiences complex transition among a diverse range of motion states such as one-periodic, multi-periodic and chaotic motions. Specifically, the significant difference in system bifurcation characteristics can be observed under different adhesion conditions. The suitable gear backlash and error fluctuation can avoid the chaotic motion, and thus, reduce the vibration amplitude of the system. Similarly, the increasing friction coefficient can also suppress the unstable state and improve the stability of the system.
Originality/value
The numerical results may provide a systemic understanding of dynamic characteristics and present some available information to design and optimize the transmission performance of the locomotive traction system.
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Mingjun Zhan, Hongming Gao, Hongwei Liu, Yidan Peng, Dan Lu and Hui Zhu
The objective of this paper is to propose a consumer-behavior-based intelligence (CBBI) model to identify market structure so as to monitor product competition. Competitive…
Abstract
Purpose
The objective of this paper is to propose a consumer-behavior-based intelligence (CBBI) model to identify market structure so as to monitor product competition. Competitive intelligence extracted from Chinese e-business clickstream data is exploited to examine the relevance of consumers' heterogeneous behavioral feedback, namely, click, tag-into-favorite, time-of-browsing, add-into-cart, and remove-from-cart, to visualize the competitive product market structure and to predict product-level sales.
Design/methodology/approach
Our proposed CBBI model consists of visualization and prediction, which explore e-business clickstream data. We conduct the visualization and segmentation of market structure in the form of a perceptual map by employing K-means clustering algorithm and multidimensional scaling technique. Concurrently, we developed an updated Bayesian linear regression (BLR) to predict product-level sales by considering consumers' heterogeneous feedback. Our updated BLR specifically integrated the estimated knowledge of the previous periods to verify whether product sales are period-dependent due to the consumer memory effect in e-commerce, improving the conventional BLR of diffuse prior distribution setup in terms of mean absolute error (MAE) and root mean squared error (RMSE).
Findings
Considering the performance of consumers' heterogeneous actions, the present research visualized three different segments of the competitive market structure in a perceptual map, and its horizontal axis is shown as a signal of the ascending trend of product sales. The previous five-day period was ascertained to be the best size of a time window for the consumer memory effect on product sales prediction. This hypothesis is supported by the concept that product sales are period-dependent. The results of the proposed updated BLR indicate that consumer tag-into-favorite, add-into-cart, and remove-from-cart feedback have positive impacts on product-level sales while click and time-of-browsing have the opposite effect.
Originality/value
While the identified competitive product market structure elaborates consumer heterogeneous feedback toward alternative product choices, this paper contributes by extending those homogeneous consumer preferences-related marketing studies. The perceptual map's configuration in respect to period-dependent product sales facilitates the effective inclusion of consumer behavior application in product sales prediction research in e-commerce. This paper helps sellers and retailers better comprehend the impacts of heterogeneous feedback and the consumer memory effect on the degree of competition in the form of product sales. The research results also offer a managerial implication about shaping the competitive edge by conducting different product management strategies in e-commerce platforms.
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Jia-Neng Cheng, Yan Liu, Hongwei Che, Guoping Yan, Xinghai Liu, Xiaojing Liu, Xiaoyan Wang and Bo Bi
The purpose of this investigation was to study a transparent coating based on organic silicone resins prepared by the hydrolysis and condensation of methyltriethoxysilane and…
Abstract
Purpose
The purpose of this investigation was to study a transparent coating based on organic silicone resins prepared by the hydrolysis and condensation of methyltriethoxysilane and tetraethoxysilane.
Design/methodology/approach
The coating film was characterized by IR, UV, thermal gravity analysis, scanning electron microscope and an automatic contact angle meter. Some properties of the coating film, such as adhesion, impact resistance and wear-resistance also were evaluated.
Findings
These uniform, clear and smooth coating films possessed the high transparent and light transmittance, high density, high hydrophobicity, good adhesion, hardness and anti-corrosion.
Originality/value
The coating may be considered as a protective film for the surfaces of the metals and plastics.
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Hongwei He and Yan Li
Little research on brand extension observes the role of technological levels between parent brand and brand extension on consumers' attitudes toward brand extension. The present…
Abstract
Purpose
Little research on brand extension observes the role of technological levels between parent brand and brand extension on consumers' attitudes toward brand extension. The present study aims to explore how consumers evaluate technology‐based brand extension and how technologic direction interacts with brand loyalty and fit in affecting brand extension evaluation.
Design/methodology/approach
A field experiment (n=200) was conducted. Participants were assigned to two equal‐number groups that differed in the technological direction of brand extension (i.e. upward extension versus downward extension).
Findings
This field study finds that downward brand extension is generally evaluated more favourably due to its positive effect on perceived fit; technological direction moderates the effect of fit on brand extension – fit has stronger positive effect on downward brand extension than on upward brand extension; fit moderates the effect of brand loyalty on brand extension – when fit is high, brand loyalty's effect is positive, whereas when fit is low, brand loyalty can have negative effect on brand extension; and the moderating effect of fit on brand loyalty is further moderated by technological direction of brand extension – for upward brand extension, the moderating effect of fit on brand loyalty is as general, but for downward brand extension, fit enhances the effect of brand loyalty.
Research limitations/implications
The results lend significant new insights to brand extension research by showing that the effect of brand loyalty on brand extension is moderated not only by fit but also by technological direction, and that the moderating effect of fit on brand loyalty's effect on brand extension is further dependent on the technological direction.
Practical implications
For the management of upward brand extension – where a lower‐tech brand extends to a high‐tech product, more care and caution should be taken, since brand loyalty could have a negative effect if the upward brand extension is not perceived to fit the parent brand image. Thus, it becomes extremely important to manage the fit between the lower‐tech parent brand and the higher‐tech extended product.
Originality/value
This is one of few studies examining the effect of technology on brand extension. The major original finding of this study is that the effect of brand loyalty on brand extension is moderated by fit, whose moderating fit is further moderated by technologic direction of brand extension.
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Bo Zeng, Hongwei Liu, Hongzhou Song, Zhe Zhao, Shaowei Fan, Li Jiang, Yuan Liu, Zhiyuan Yu, Xiaorong Zhu, Jing Chen and Ting Zhang
The purpose of this paper is to design a multi-sensory anthropomorphic prosthetic hand and a grasping controller that can detect the slip and automatically adjust the grasping…
Abstract
Purpose
The purpose of this paper is to design a multi-sensory anthropomorphic prosthetic hand and a grasping controller that can detect the slip and automatically adjust the grasping force to prevent the slip.
Design/methodology/approach
To improve the dexterity, sensing, controllability and practicability of a prosthetic hand, a modular and multi-sensory prosthetic hand was presented. In addition, a slip prevention control based on the tactile feedback was proposed to improve the grasp stability. The proposed controller identifies slippages through detecting the high-frequency vibration signal at the sliding surface in real time and the discrete wavelet transform (DWT) was used to extract the eigenvalues to identify slippages. Once the slip is detected, a direct-feedback method of adjusting the grasp force related with the sliding times was used to prevent it. Furthermore, the stiffness of different objects was estimated and used to improve the grasp force control. The performances of the stiffness estimation, slip detection and slip control are experimentally evaluated.
Findings
It was found from the experiment of stiffness estimation that the accuracy rate of identification of the hard metal bottle could reach to 90%, while the accuracy rate of identification of the plastic bottles could reach to 80%. There was a small misjudgment rate in the identification of hard and soft plastic bottles. The stiffness of soft plastic bottles, hard plastic bottles and metal bottles were 0.64 N/mm, 1.36 N/mm and 32.55 N/mm, respectively. The results of slip detection and control show that the proposed prosthetic hand with a slip prevention controller can fast and effectively detect and prevent the slip for different disturbances, which has a certain application prospect.
Practical implications
Due to the small size, low weight, high integration and modularity, the prosthetic hand is easily applied to upper-limb amputees. Meanwhile, the method of the slip prevention control can be used for upper-limb amputees to complete more tasks stably in daily lives.
Originality/value
A multi-sensory anthropomorphic prosthetic hand is designed, and a method of stable grasps control based on slip detection by a tactile sensor on the fingertip is proposed. The method combines the stiffness estimation of the object and the real-time slip detection based on DWT with the design of the proportion differentiation robust controller based on a disturbance observer and the force controller to achieve slip prevention and stable grasps. It is verified effectively by the experiments and is easy to be applied to commercial prostheses.
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Iman Boseila, Abeer A. Mahrous and Ehab Abouaish
The paper examined the impact of brand-identity expressiveness and perceived brand value that was neglected in prior literature, in addition to perceived brand quality and…
Abstract
Purpose
The paper examined the impact of brand-identity expressiveness and perceived brand value that was neglected in prior literature, in addition to perceived brand quality and prestige, on behavioral intention. Research also tests if certain consumer values moderate this relationship.
Design/methodology/approach
Mall-interception technique was used. Also, partial least square-structural equation modelling (PLS-SEM) was used to analyze data and test research hypotheses.
Findings
Results indicate that perceived brand globalness (PBG) and perceived brand localness (PBL) are significantly positively associated with perceived quality and prestige. Besides, the inclusion of brand-identity expressiveness and perceived brand value was supported. PBL showed a greater association with brand identity expressiveness compared to PBG, different from previous findings. Furthermore, the total indirect effect of PBG on behavioral intentions was significant through the routes of perceived quality and prestige, compared to a weak and non-significant effect for PBL through the quality route.
Originality/value
This study proposes a comprehensive model testing additional pathways through which global and local brands can boost their preferences.
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Yuan Meng, Hongwei Lin, Weijing Gong, Rui Guan and Li Dong
This study aims to discover the factors which influence user satisfaction levels and their continuous use intention (CUI) of academic library social media, and then considers how…
Abstract
Purpose
This study aims to discover the factors which influence user satisfaction levels and their continuous use intention (CUI) of academic library social media, and then considers how to promote and improve further work on library social media to reduce user churn and increase user satisfaction.
Design/methodology/approach
An updated DeLone and McLean information systems success (D&M ISS) model and the expectation confirmation model for information systems continuance (ECM-ISC) with new variables of emotions are used to examine the factors which influence user satisfaction levels and CUI of academic library social media through 445 questionnaires. Partial least squares structural equation modelling was used to analyse the data and presented in tables.
Findings
The results show that information quality, system quality and emotions affect user satisfaction and CUI, and reveal that emotions can affect that most obviously.
Research limitations/implications
The WeChat public platform is mainly used in China, so the study only focuses on Chinese academic libraries. There are still limitations on the settings of observed variables which cannot cover all the causes of users’ positive and negative emotions. In addition, although the respondents of this questionnaire can represent academic library users, 445 samples are still fairly low in contrast to the great number of academic library WeChat public platform users.
Originality/value
This study integrates ECM-ISC and D&M ISS models, adds positive and negative emotions as new variables, to broaden the application scope of these models, and demonstrates the applicability of these two models in the fields of researching academic library social media, expanding and deepening related theories above. This also provides practical reference for academic libraries on how to improve user satisfaction and CUI of academic library social media and academic library WeChat public platforms, promoting the development of academic library social media.
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Anan Zhang, Shi Chen, Fan Zhang, Xuliang Zhang, Hongwei Li and Xue Gong
It is very indispensable for the various control centers of multi-transmission system owners (TSOs) grids to coordinate their reactive power optimization (RPO) efforts. However…
Abstract
Purpose
It is very indispensable for the various control centers of multi-transmission system owners (TSOs) grids to coordinate their reactive power optimization (RPO) efforts. However, such coordinated equilibrium point is comparatively hard to achieve unless one TSO control center could obtain all grids’ information in detail, which may lead to confidential issue and heavy communicating load. The purpose of this paper is to propose a solution to optimizing the reactive power control efforts among multi-TSOs grids with a mathematic interconnection model and reasonable communication cost.
Design/methodology/approach
Based on the interconnected power network equation, the stability-related optimum reactive power injection and the power-loss-related optimum reactive power injection were derived, respectively. Furthermore, according to the decomposition-and-coordination-based computing methodology, a coordinated RPO model for interconnected TSOs was designed, taking into consideration both the static voltage stability and economy.
Findings
The extreme values for the indicator L of power grid voltage stability and active power loss function were found and proved to be minimums. According to these extreme values, an expression for the reactive power injection at interconnected nodes between TSOs grids was obtained, and a coordinated strategy of RPO was established, which could take the static voltage stability and economy into consideration without confidential concern.
Originality/value
The existence of minimum values for indicator L of voltage stability and power loss was demonstrated, respectively. And the method presented in this paper can ensure the safety of information among different TSO grids, i.e. avoiding confidential issues. In particular, the coordinated control method can be implemented on the local power grid without knowing all of the parameters of its interconnection.
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Jingyi Wang, Run Yuan and Hongwei Shi
The purpose of this paper is to evaluate the service quality of university library more accurately and dynamically and improve the service efficiency of library. The paper…
Abstract
Purpose
The purpose of this paper is to evaluate the service quality of university library more accurately and dynamically and improve the service efficiency of library. The paper realizes quantified representation of library service quality and overcomes the shortcoming of the traditional library evaluation system, which does not consider reader’s identity and cannot be evaluated separately. In addition, according to the function configuration of each department of library, a relation between library evaluation parameter and its organization structure is built. According to the evaluation results and the chain of relations, some suggestions for improving library service can be put forward; thus, it can improve the quality of library service and management efficiency.
Design/methodology/approach
In this paper, a four-dimensional (4-D) representation method is put forward to express four kinds of parameters, namely, the category of participants, the number of people evaluated, the rating level and the weight of parameters, which is expressed by chromaticity and a three-dimensional column coordinate space. Considering the existing evaluation methods such as LibQUAL+TM, the content of evaluation parameters, the grade of evaluation parameters and the weight of evaluation parameters are modified. Using the volume and the equivalent number of people under this evaluation system, the evaluation grade can be quantified and the total results can be evaluated quantitatively.
Findings
The evaluation model proposed in this paper is a 4-D system that is based on content parameters to evaluate the number of participants, score segments, evaluation content weights and reader information. It gives full consideration to the good advice of many scholars and combines the actual operation of domestic libraries. The situation effectively integrates successful experience abroad. Both the undergraduate and teacher sampling evaluation results and their analysis in this paper show the accuracy and credibility of the method.
Originality/value
Although the satisfaction index model has a good effect in foreign countries, taking into account that readers of university libraries in China are different from those in foreign countries in the evaluation methods of the tutorial, professional multi-level evaluation will produce greater errors in practical applications. The traditional four-level method based on Chinese education evaluation (excellent, good, pass and fail) has reached consensus among teachers and students in practical application, and it is easy to achieve consistency. Therefore, this paper also adopts four-level evaluation, that is, very satisfied, satisfied, generally satisfied and very dissatisfied. The embedded application will be able to perform dynamic evaluation and thus can be used in China. The evaluation of service quality in university libraries provides an effective new method.