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1 – 10 of 72Sihang Zhang, Xiaojun Ma, Huifen Xu and Jijian Lu
This paper seeks to investigate the differences in the teachers’ professional development (TPD) by mentorship in workplace. The authors examined the role of mentorship in the PD…
Abstract
Purpose
This paper seeks to investigate the differences in the teachers’ professional development (TPD) by mentorship in workplace. The authors examined the role of mentorship in the PD of teachers and conducted a meta-analysis of pertinent empirical data.
Design/methodology/approach
Using data from over 2,900 individuals, 66 experiments and 12 countries, the authors presented a meta-analysis of the association between workplace mentorship and TPD.
Findings
The authors concluded that mentoring activities could boost the TPD to some extent. It contributes positively to the discipline of science and language, kindergarten, individual mentoring and curriculum research. In addition, the periodicity should not exceed 1 year.
Research limitations/implications
The results of the meta-analysis are restricted to short-term mentorship activities, and the sample size is modest. Building upon the findings from the literature review and meta-analysis, the authors delineated a research agenda for prospective investigations. This includes an imperative for further exploration into the nexus between mentoring and the PD of educators.
Practical implications
Based on the available literature and meta-analysis findings, the authors developed a framework for the “Experts in the classroom” TPD pattern.
Originality/value
This is the first meta-analysis evaluating the association between mentorship and TPD.
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Xiaojun Ma, Yiwen Jian and Yue Cao
The purpose is to present parameters of a new design code, which is intended to control the indoor air environment for sports buildings in China.
Abstract
Purpose
The purpose is to present parameters of a new design code, which is intended to control the indoor air environment for sports buildings in China.
Design/methodology/approach
Based on requirements of international sports federations the characteristics of indoor airflow of sports buildings in China, include the parameters of indoor air environment of gymnasiums and natatoriums, air velocity, temperature, humidity and fresh air volume. Some illustrations and considerations are shown too.
Findings
Compared with the international standards and design guidelines, the Chinese new design code has more detailed parameters for high level sports game.
Research limitations/implications
Not all the indoor air parameters of the code are mentioned in this paper. The designs of sports building are built for high level sports games in recent years of China, the parameters of class A are paid more attention to in the paper.
Practical implications
The contents of paper could be the major designs in heating, ventilation and air conditioning system in sports building.
Originality/value
This paper could be a guide to advice the designing of indoor air environment of sports building, especially for the Beijing Olympic game in 2008, and is useful to help advanced HVAC design and analysis on the similar large space buildings.
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Xiaojun Wu, Weijun Liu and Michael Yu Wang
The representation of Heterogeneous Object (HO) is divided into two categories: Data model (DM) and material evaluation paradigm (MEP). A hybrid methodology with geometry model…
Abstract
The representation of Heterogeneous Object (HO) is divided into two categories: Data model (DM) and material evaluation paradigm (MEP). A hybrid methodology with geometry model and volumetric dataset to represent heterogeneous properties is proposed in this paper. Geometry model of an object can guarantee the accuracy of the final HO slices; and volumetric dataset lends the flexible manipulability and other advantages to HO representation. Two MEPs, namely distance field (DF) based and Fixed Reference Features & Active Grading Source(s) (FRF&AGS) are presented to facilitate the process of HO representation according to the designer)s input parameters. The DM can be modified interactively with users until the final satisfactory result is obtained. In this paper, a scheme of HO slicing is described. In this method, we utilize the slices contour of geometrical model as constraint to reconstruct the HO slices, which can theoretically achieve the same accuracy with the geometrical shape. Some examples of Heterogeneous object represented with our scheme are provided.
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Jiaxiang Hu, Xiaojun Shi, Chunyun Ma, Xin Yao and Yingxin Wang
The purpose of this paper is to propose a multi-feature, multi-metric and multi-loop tightly coupled LiDAR-visual-inertial odometry, M3LVI, for high-accuracy and robust state…
Abstract
Purpose
The purpose of this paper is to propose a multi-feature, multi-metric and multi-loop tightly coupled LiDAR-visual-inertial odometry, M3LVI, for high-accuracy and robust state estimation and mapping.
Design/methodology/approach
M3LVI is built atop a factor graph and composed of two subsystems, a LiDAR-inertial system (LIS) and a visual-inertial system (VIS). LIS implements multi-feature extraction on point cloud, and then multi-metric transformation estimation is implemented to realize LiDAR odometry. LiDAR-enhanced images and IMU pre-integration have been used in VIS to realize visual odometry, providing a reliable initial guess for LIS matching module. Location recognition is performed by a dual loop module combined with Bag of Words and LiDAR-Iris to correct accumulated drift. M³LVI also functions properly when one of the subsystems failed, which greatly increases the robustness in degraded environments.
Findings
Quantitative experiments were conducted on the KITTI data set and the campus data set to evaluate the M3LVI. The experimental results show the algorithm has higher pose estimation accuracy than existing methods.
Practical implications
The proposed method can greatly improve the positioning and mapping accuracy of AGV, and has an important impact on AGV material distribution, which is one of the most important applications of industrial robots.
Originality/value
M3LVI divides the original point cloud into six types, and uses multi-metric transformation estimation to estimate the state of robot and adopts factor graph optimization model to optimize the state estimation, which improves the accuracy of pose estimation. When one subsystem fails, the other system can complete the positioning work independently, which greatly increases the robustness in degraded environments.
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Baoguang Ma, Cheng Chen, Xiaojun Xie, Yanhui Chen, Qiuyu Zhang, Dong Lv and Zhenguo Liu
The purpose of this study is to provide effective and environmental-friendly corrosion inhibitors derived from graphene oxide for Q235 steel.
Abstract
Purpose
The purpose of this study is to provide effective and environmental-friendly corrosion inhibitors derived from graphene oxide for Q235 steel.
Design/methodology/approach
Nontoxic and environment-friendly 4-aminobenzoic acid was used to functionalize graphene oxide via amidation and diazotization. The obtained amidation 4-aminobenzoic acid functionalized graphene oxide (PAGO) and diazotization 4-aminobenzoic acid functionalized graphene oxide (PDGO) were characterized by FTIR, Raman and TEM, while the inhibition efficiencies were analyzed by electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization (PDP). Furthermore, theoretical inhibition efficiencies were investigated by density functional theory (DFT) approach.
Findings
At a concentration of 40 ppm, the maximum inhibition efficiency of PAGO and PDGO were 97.90% and 96.72% in EIS measurement, respectively, which were in accordance with PDP data. Moreover, experimental results were supported by DFT-based quantum chemical calculation.
Originality/value
Environmental-friendly PAGO and PDGO were synthesized successfully. The synthetic inhibitors exhibited excellent inhibition efficiencies in EIS and PDP measurements. Furthermore, a computational study using DFT supported the trend that PAGO was better inhibitor than PDGO.
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Guangming Zhang, Xiaojun Liu, Lei Mei, Huimin Ouyang and Xin Deng
This paper aims to describe a simple low-pass filter to suppress torque pulsation and current harmonics in permanent magnet synchronous motor (PMSM) drives.
Abstract
Purpose
This paper aims to describe a simple low-pass filter to suppress torque pulsation and current harmonics in permanent magnet synchronous motor (PMSM) drives.
Design/methodology/approach
For the control of the PMSM, a field-oriented control algorithm is always used. The proposed filter is actually a resistance, inductance, capacitance (RLC) filter. At the output of the inverter and the input of PMSM, an RLC filter is connected. This filter suppresses current harmonics through filtering phase voltage harmonics. Analysis of the filter is achieved through frequency characteristics analysis.
Findings
This filter can effectively filter out the harmonic of phase voltage. Both the simulation and experiment results show that the proposed filter can effectively suppress torque pulsation and current harmonics in PMSM drives. Also, the method of selecting filter parameters and the whole control system are very simple.
Research limitations implications
The filter increases the design cost of the system.
Practical implications
The harmonics and torque ripple of phase current are greatly suppressed. Also, the loss of the PMSM reduced.
Originality/value
The method of selecting filter parameters and the analysis of the proposed filter are proposed for the first time.
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Keywords
Xuebing Dong, Yaping Chang and Xiaojun Fan
Marketers recognize that the internet is crucial in the lives of consumers; thus, they invest money on online advertisements. Using multiple online media primarily influences the…
Abstract
Purpose
Marketers recognize that the internet is crucial in the lives of consumers; thus, they invest money on online advertisements. Using multiple online media primarily influences the message acceptance of consumers. The synergistic effect of online multimedia relies on form, content, and sources of information, and time. The paper aims to discuss these issues.
Design/methodology/approach
A model that reflects the influence of the characteristics of online multimedia on message response through message acceptance is established based on theories of information persuasion, encoding variability, and multiple-source assumption. Based on a survey of 411 online media users, the study applies partial least-squares regression to test the research model.
Findings
The results show that variety of forms, complementary of contents, diversity of sources, and time interval influence message response via message strength. Complementary of contents and diversity of sources affect message response via perceived credibility. Synergy type moderates the relationship between variety of forms and perceived credibility and between diversity of sources and perceived credibility.
Research limitations/implications
The current study mainly tests the effect of these characteristics on message response and the moderating effect of synergy type. Future research can examine the effect of these characteristics on information seeking and consumption behavior and the moderating effect of the cognitive mode of consumers.
Practical implications
This study provides insight into the characteristics of synergy and contributes to the literature on integrated marketing communication. The results provide guidance for practitioners to effectively plan online multimedia practices.
Originality/value
This study explored the influence of the characteristics of online media synergy on message response through message acceptance. The study also discussed the moderating effect of the type of online multimedia synergy.
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Xiaojun Du, He Liu, Lingjing Bao and Peng Huang
This paper aims to investigate the relationships between the strategic type of cross‐border mergers and acquisitions (M&As) and enterprise growth, and the moderating role of…
Abstract
Purpose
This paper aims to investigate the relationships between the strategic type of cross‐border mergers and acquisitions (M&As) and enterprise growth, and the moderating role of Chinese companies' organizational factors, including organizational structure, organizational experience, cultural distance and relative size.
Design/methodology/approach
The authors, as researchers, have mixed the strategic choice and post‐M&As integration into a comprehensive framework while building the theoretical model of “Strategic Type of Cross‐border M&As‐Organizational Factors‐Enterprise Growth” (ST‐OF‐EG). In this paper, they have empirically examined the model using hierarchical regression by analyzing 76 cross‐borders M&A events of overseas‐listed Chinese companies over the 2000‐2007 period.
Findings
The analysis shows that: related cross‐border M&As are better for enterprise growth than unrelated diversification cross‐border M&As; and among the organizational factors, studied organizational structure and organizational experience show a positive significance in terms of the relationship between the strategic type of cross‐border M&As and enterprise growth. The moderating role of cultural distance and relative size is non‐significant.
Research limitations/implications
In this paper, the moderating effect of cultural distance was found to be insignificant. However, further research is encouraged.
Practical implications
Chinese companies should pay attention to strategic choices before cross‐border M&As. They should expand abroad to markets step by step. They should merge the companies that have the higher relevance on a product, industry or market first. On the basis of specialization, Chinese companies should make themselves stronger and then develop from specialization to proper diversification, which is a robust path to achieve enterprise growth. Besides, Chinese companies should accumulate international experience as soon as possible and organizational structure should match the strategic choice.
Originality/value
This paper would be immensely helpful to Chinese companies to plan their cross‐border M&As strategy in a way that would enhance growth and core‐competence.
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Chunjie Wei, Qi Chen, Jimin Xu, Xiaojun Liu and Wei Wang
The purpose of this paper is to explore the operating characteristics of gallium-based liquid metals (GLMs) by directly adding them as lubricants in real mechanical equipment.
Abstract
Purpose
The purpose of this paper is to explore the operating characteristics of gallium-based liquid metals (GLMs) by directly adding them as lubricants in real mechanical equipment.
Design/methodology/approach
This paper conducts an analysis of the rotor-bearing system under GLM lubrication using a constructed test rig, focusing on vibration signals, surface characteristics of the friction pair, contact resistance and temperature rise features.
Findings
The study reveals that GLM can effectively improve the lubrication condition of the tribo-pair, leading to a more stable vibration signal in the system. Surface analysis demonstrates that GLM can protect the sample surface from wear, and phase separation occurs during the experimental process. Test results of contact resistance indicate that, in addition to enhancing the interfacial conductivity, GLM also generates a fluid dynamic pressure effect. The high thermal conductivity and anti-wear effects of GLM can reduce the temperature rise of the tribo-pair, but precautions should be taken to prevent oxidation and the loss of its fluidity.
Originality/value
The overall operating characteristics of the rotor-bearing system under GLM lubrication were investigated to provide new ideas for the lubrication of the rotor-bearing system.
Peer review
The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-03-2024-0067/
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Wan Han and Xiaojun Hu
When smelting Al-Li alloy, the material inevitably comes into contact with various oxide-refractories. These refractories are subjected to varying degrees of melt-corrosion at…
Abstract
Purpose
When smelting Al-Li alloy, the material inevitably comes into contact with various oxide-refractories. These refractories are subjected to varying degrees of melt-corrosion at high temperatures. The purpose of this study is to find stable oxide refractories at casting temperature.
Design/methodology/approach
Four materials were selected for evaluation, and their corrosion by the Al-Li alloy at casting temperature and different holding times was measured. Subsequently, scanning electron microscopy and energy-dispersive spectroscopy were used to study the interfaces. Stable refractory materials were selected by comparing the thicknesses of the reaction layers.
Findings
The thickness of the Al-Li/ZrO2 reaction layer varies linearly with the square root of the holding duration. Therefore, the growth of the reaction layer is controlled by diffusion. The reaction layer of Al-Li/Al2O3 is thinner, and its growth is also controlled by diffusion. However, there were no obvious reaction layers between the Al-Li alloy and MgO or Y2O3. By comparing these reaction-layer thicknesses, the order of stability was found to be ZrO2 < Al2O3 < MgO and Y2O3.
Originality/value
These results provide a scientific basis for the optimal selection of refractory materials for Al-Li alloy smelting.
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