Tianyu Lu, Juanmian Lei, Xiaosheng Wu and Jintao Yin
The purpose of this paper is to examine the ability of the harmonic balance method for predicting the aerodynamic characteristics of rigid finned spinning vehicle.
Abstract
Purpose
The purpose of this paper is to examine the ability of the harmonic balance method for predicting the aerodynamic characteristics of rigid finned spinning vehicle.
Design/methodology/approach
The aerodynamic characteristics of a rigid four-finned spinning vehicle at Mach number 2.5 and angle of attack of 20 degrees are simulated using the harmonic balance method and the unsteady time-accurate approach based on the dual-time method. The numerical results are analyzed, and the computed aerodynamic coefficients of the harmonic balance method are compared with those of the dual-time method. The influence of the number of harmonics is presented. The computed Magnus force and moment coefficients are compared with the experimental data. The flow fields at different roll angles are presented. The computational efficiency of harmonic balance method is analyzed.
Findings
The results show that the aerodynamic coefficients of spinning vehicle could be predicted by the harmonic balance method with reasonable accuracy compared with the dual-time method. For the harmonic balance method, the accuracy of the computed leeward side flow is relatively poor compared with that of the computed windward side flow. Meanwhile, the computational efficiency is influenced by initial guess and the intensity of unsteady effect.
Practical implications
The harmonic balance method could be used for the aerodynamic prediction of spinning vehicle, which may improve the efficiency of vehicle design.
Originality/value
This paper presents the results of the harmonic balance method for simulating the aerodynamic characteristics of finned spinning vehicle. The accuracy and efficiency of the method are analyzed.
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Xiaotong Jiang, Xiaosheng Cheng, Qingjin Peng, Luming Liang, Ning Dai, Mingqiang Wei and Cheng Cheng
It is a challenge to print a model with the size that is larger than the working volume of a three-dimensional (3D) printer. The purpose of this paper is to present a feasible…
Abstract
Purpose
It is a challenge to print a model with the size that is larger than the working volume of a three-dimensional (3D) printer. The purpose of this paper is to present a feasible approach to divide a large model into small printing parts to fit the volume of a printer and then assemble these parts into the final model.
Design/methodology/approach
The proposed approach is based on the skeletonization and the minima rule. The skeleton of a printing model is first extracted using the mesh contraction and the principal component analysis. The 3D model is then partitioned preliminarily into many smaller parts using the space sweep method and the minima rule. The preliminary partition is finally optimized using the greedy algorithm.
Findings
The skeleton of a 3D model can effectively represent a simplified version of the geometry of the 3D model. Using a model’s skeleton to partition the model is an efficient way. As it is generally desirable to have segmentations at concave creases and seams, the cutting position should be located in the concave region. The proposed approach can partition large models effectively to well retain the integrity of meaningful parts.
Originality/value
The proposed approach is new in the rapid prototyping field using the model skeletonization and the minima rule. Based on the authors’ knowledge, there is no method that concerns the integrity of meaningful parts for partitioning. The proposed method can achieve satisfactory results by the integrity of meaningful parts and assemblability for most 3D models.
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Xiangbo He, Xiaosheng Liang, Ruirui Li, Kai Zhang, Wenchuan Chen and Yunfeng Peng
This study aims to explore the impact of multisource deformation errors on the oil film contact surface, which arise from manufacturing, assembly, oil pressure and thermal…
Abstract
Purpose
This study aims to explore the impact of multisource deformation errors on the oil film contact surface, which arise from manufacturing, assembly, oil pressure and thermal influences, on the motion accuracy of hydrostatic guideway.
Design/methodology/approach
Using thermal-structural coupling simulations, this research investigates the effects of assembly, oil pressure and thermal factors on deformation errors of the oil film contact surface. By integrating these with manufacturing errors, a profile error model for the oil film contact surface is developed, characterizing the cumulative effect of these errors. Using kinematic theory and progressive Mengen flow controller characteristics, the motion error at any position of the hydrostatic guideway is quantified, examining how surface error traits impact motion accuracy.
Findings
The error averaging effect is affected by the profile error of oil film contact surface. Meanwhile, the motion accuracy of hydrostatic guideway is highly sensitive to the oil film contact surface error amplitude.
Originality/value
This approach allows for precise prediction and analysis of motion accuracy in hydrostatic guideways during the design and manufacturing stages. It also provides guidance for planning process tolerances.
Peer review
The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-03-2024-0063/
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Najaf Iqbal, Ju Feng Xu, Zeeshan Fareed, Guangcai Wan and Lina Ma
This study attempts to document the impact of financial leverage on corporate innovation in the Chinese nonfinancial public firms listed on Shenzhen and Shanghai stock exchanges.
Abstract
Purpose
This study attempts to document the impact of financial leverage on corporate innovation in the Chinese nonfinancial public firms listed on Shenzhen and Shanghai stock exchanges.
Design/methodology/approach
The firm-level data are collected from CSMAR database for ten years, ranging from 2007 to 2016. The authors have employed the panel fixed effects model and further system GMM approach for analysis. The sample is segregated on the basis of state (SOE) and nonstate ownership (NSOE) to check for the diverse effects. In total, three different proxies of financial leverage are used to unearth the varying impact of short-time and long-term leverage separately. Further, corporate innovation is divided into input innovation (R&D/Sales and R&D/Assets) and output innovation (patents and inventions).
Findings
The results suggest that financial leverage is detrimental to the input innovation while conducive for the output innovation when measured by the number of patents. Contrarily, leverage has a negative influence over the output innovation when measured by the number of inventions. This implies that leverage is more damaging for the highest form of innovativeness (inventions) in China. Input innovation is more sensitive to the changes in long-term leverage versus short-term leverage. Further, the authors find that innovation in SOEs is more sensitive to the changes in the leverage as compared to the NSOEs. The results are free from the threat of endogeneity and identification problems, as reported by the system GMM model.
Research limitations/implications
The authors did not segregate the sample on the basis of industry/sector.
Practical implications
The firms pursuing a strategy of radical innovation should try to keep their debt levels lower in order to achieve a higher innovation performance. Although, a rise in the leverage may mean an increased access to finance for a firm but such an access comes at a cost in the form of damage to the corporate innovation. However, increased debt financing may not be so bad for the firms that want to achieve a moderate and not the highest level of innovation. Such firms can produce recurring and synergic effects with debt financing and moderate innovation, once they achieve a level of innovation performance that satisfies their financiers.
Originality/value
To the best of authors’ knowledge, this is probably the first study to check the impact of firm-level financial leverage on both input and output innovation in the Chinese public-listed nonfinancial firms' panel data perspective till now.
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Maria Luiza de Souza Morato and Karine Araujo Ferreira
The pupose of this study is to systematically review the current literature on the value stream mapping (VSM) application in the construction industry to investigate the evolution…
Abstract
Purpose
The pupose of this study is to systematically review the current literature on the value stream mapping (VSM) application in the construction industry to investigate the evolution observed over time and the results obtained by adopting this tool. In addition, special attention was given to the potential of VSM in identifying loss and waste, as well as their main causes.
Design/methodology/approach
The study analyses papers in literature using Preferred Reporting Items for Systematic Reviews and Meta-Analyses research protocol. As a result, 383 papers were initially identified, and 47 papers were selected.
Findings
It was observed that the number of studies addressing this topic has been increasing over the past decade and findings related to the evolution, application and the benefits obtained from the VSM application in context of construction were presented. Additionally, the authors found that the two most cited lean wastes were waiting and defects in the production chain. The main causes of this waste and loss were also identified in this work.
Practical implications
This paper contributes by presenting the applicability of VSM as a tool in the construction as found in the literature. For academics, it will be possible to clearly observe research gaps and for industry managers, to identify the main sources of waste and assess the performance of the tool’s application.
Originality/value
The study uses a systematic review to analyze the application of the VSM tool in the construction industry and provides guidance for future research by identifying research gaps, in addition to conducting an extensive analysis of the tool’s potential in waste identification in the studied papers and their primary causes.
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The purpose of this paper is to apply analysis of public discourses on Ze Xiao to explore and interpret the power relationships shaping inequality in admission to public junior…
Abstract
Purpose
The purpose of this paper is to apply analysis of public discourses on Ze Xiao to explore and interpret the power relationships shaping inequality in admission to public junior high schools in urban China.
Design/methodology/approach
This study first introduces the rise of Ze Xiao as an educational phenomenon in China. It then elucidates power relationships in public school admission by analyzing continuities and changes in stakeholders’ interaction in public school admission. It concludes by discussing educational reform for equal public school admission in urban China. Data were collected from written and spoken texts about public school admission, including newspaper articles from the 1980s to the 2000s, policy documents and interviews with relevant stakeholders.
Findings
Findings demonstrate that multi-layered power relationships caused diverse inequalities in admission to public secondary education in urban China. These are represented by political and institutional privileges and an imbalance in education development during the social transition from a profit-driven approach in the 1990s to a balance-centered one after 2000. Arguably, there is a necessity to further promote a systematic reform to terminate the privileges and imbalance for an equal and balanced public secondary education in urban China post-2015.
Originality/value
This study attempts to make a contribution toward reconstructing the meaning of inequality in admission to public junior high schools in urban areas by revealing the power relationships among stakeholders constituted through their interactions in public education during the different stages of socio-economic development in urban China.
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Qifeng Zhao and Yongzhong Wang
The purpose of this paper is to investigate how the pay gap between the management and ordinary employees influence corporate technology innovation.
Abstract
Purpose
The purpose of this paper is to investigate how the pay gap between the management and ordinary employees influence corporate technology innovation.
Design/methodology/approach
This study built a tournament model based on inventor innovation and career promotion. In addition, the authors use IV-GMM estimation method to address the possible endogeneity issue in the regressions.
Findings
Based on the unbalanced panel data of patents and pay gap in 1,501 Chinese listed manufacturing firms during 2001-2015, this paper finds that the pay gap could lead inventor innovation and improve technology innovation. The pay gap could encourage corporate innovation significantly: 1 percent increase in pay gap may increase the number of patents by 2 percent in the next year. The pay gap between the management and ordinary employees facilitates corporate innovation via two possible channels. First, inventor innovation and career promotion. Inventors are selected into the management mainly based on their innovation output. The larger the pay gap, the more innovation incentives and patents would gain. Second, investment increase in technology innovation. The pay gap and more patents that inventors gain would increase the ratio of inventors promoted to the management, who tend to pour more resources into R&D activities and absorb more inventors to the management due to their sectionalism and R&D preference. The above two channels constitute a positive feedback mechanism among technology innovation, inventor promotion and increase in R&D investment.
Research limitations/implications
This paper highlights that pay gap between the management and ordinary employees is an important issue that could encourage corporate innovation. The conclusions imply that pay gap could encourage inventors to work hard and produce more patents, which could help them to enter into the management such as executives or directors.
Originality/value
This study contributes to the current literature by implying that pay gap could have positive effects on innovation through theoretical and empirical analysis. Also, this study finds that inventor promotion due to the pay gap is a critical channel to stimulate corporate technology innovation.