Zhijian Xu and Libo Xu
The purpose of this paper is to study whether there is correlation between valuation in initial public offering (IPO) and board composition, the ownership dispersion of top…
Abstract
Purpose
The purpose of this paper is to study whether there is correlation between valuation in initial public offering (IPO) and board composition, the ownership dispersion of top management teams (TMTs) and their human capitals, in entrepreneurial firms of China's new growth enterprise market (GEM). Also, it aims to evaluate the relative importance of various factors in determining initial public issuing value.
Design/methodology/approach
The SPSS 16.0 statistical package was used to perform the analysis. The authors compute descriptive statistics, calculate correlation coefficients for all variables and use multiple regression analysis test the hypothesis.
Findings
The paper shows that IPO valuation has significant positive correlation with board composition, significant negative correlation with TMT ownership dispersion, but it does not show significant correlation with TMT human capital. The empirical results also show that: the influence of variable “CEO also Founder” on IPO valuation is significant, which indicates that investors are concerned with the leadership of firms in IPO. Also the influence of the variable “underwriter prestige” on IPO valuation is also significant, but weaker, which indicates that investors still keep confidence in the well‐known underwriters for their vision and ability of judging the firms.
Research limitations/implications
Based on the first batch of 28 entrepreneurial firms listed on Chinese GEM, the sample size is relative small. Also, the measure of TMT human capital, defined by the education degree level, is not an accurate rule in this paper.
Originality/value
Focusing on 28 new firms in China's new security market, this paper presents some interesting and new findings, by using data from the first batch of listed companies in China's GEM, which comprises many privately‐owned, high technology and entrepreneurial firms.
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Zhijian Bai, Cheng Xu, Aimaitijiang Ailikamujiang and Yanqi Sun
This study, anchored in Self-Determination Theory, explores the paradoxical effects of gamification on digital health promotion, focusing on user engagement, physical activity…
Abstract
Purpose
This study, anchored in Self-Determination Theory, explores the paradoxical effects of gamification on digital health promotion, focusing on user engagement, physical activity adherence, stress levels and social dynamics.
Design/methodology/approach
In a preregistered experimental design, participants interacted with one of three fitness apps: a non-gamified control app, a competition-based gamified app (GameFit) or a self-exploration-based gamified app (ExploreFit). Quantitative data were collected through scales measuring key variables, and qualitative insights were gathered from structured diaries.
Findings
Gamification significantly enhanced user engagement and physical activity adherence. However, competition-based gamification also increased stress and negative social dynamics, with gender-specific effects: females experienced higher stress and males encountered more negative social dynamics. These adverse effects were mitigated in the ExploreFit group, suggesting that self-exploration elements in gamification can reduce negative outcomes.
Originality/value
This research offers a comprehensive analysis of the complex interplay between gamification, competition, self-exploration and health outcomes. It provides valuable insights for the design of persuasive technologies, highlighting the need for a balanced approach to gamification that considers both its benefits and potential pitfalls.
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Zhijian Wang, Yin Wang, Lin Liu, Wengsheng Zhu, Jing Li, Yujie Zhao, Haijun Pang and Qilong Wu
The aim of this study is to first investigate the surface integrity of cylindrical rollers under grinding process and then design a reasonable superfinishing process that improve…
Abstract
Purpose
The aim of this study is to first investigate the surface integrity of cylindrical rollers under grinding process and then design a reasonable superfinishing process that improve the anti-fatigue performance of cylindrical rollers by optimization of the surface integrity.
Design/methodology/approach
First, the white and dark layers produced by the grinding process is analyzed by microscope. Then, the influence of oilstone pressure on the stock removal, surface precision and crowned profile are explored. Finally, an optimal superfinishing process and a novel turnaround device are designed to improve surface integrity.
Findings
The experimental results show that as the oilstone pressure increases, the stock removal first increases and then remains stable. This hints that the stock removal of a single-time superfinishing process has an upper limit. In the current conditions, the maximum stock removal is 6 µm. Double-time superfinishing process and the turnover device can effectively eliminate the white and dark layers and improve the symmetric of roller profile. In addition, the surface precision is also improved.
Originality/value
The surface integrity of bearing rollers is very important to the application of industry field. The findings and the methods in the study can be helpful to improve the surface integrity of the bearing rollers.
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Zhe Liu, Zhijian Qiao, Chuanzhe Suo, Yingtian Liu and Kefan Jin
This paper aims to study the localization problem for autonomous industrial vehicles in the complex industrial environments. Aiming for practical applications, the pursuit is to…
Abstract
Purpose
This paper aims to study the localization problem for autonomous industrial vehicles in the complex industrial environments. Aiming for practical applications, the pursuit is to build a map-less localization system which can be used in the presence of dynamic obstacles, short-term and long-term environment changes.
Design/methodology/approach
The proposed system contains four main modules, including long-term place graph updating, global localization and re-localization, location tracking and pose registration. The first two modules fully exploit the deep-learning based three-dimensional point cloud learning techniques to achieve the map-less global localization task in large-scale environment. The location tracking module implements the particle filter framework with a newly designed perception model to track the vehicle location during movements. Finally, the pose registration module uses visual information to exclude the influence of dynamic obstacles and short-term changes and further introduces point cloud registration network to estimate the accurate vehicle pose.
Findings
Comprehensive experiments in real industrial environments demonstrate the effectiveness, robustness and practical applicability of the map-less localization approach.
Practical implications
This paper provides comprehensive experiments in real industrial environments.
Originality/value
The system can be used in the practical automated industrial vehicles for long-term localization tasks. The dynamic objects, short-/long-term environment changes and hardware limitations of industrial vehicles are all considered in the system design. Thus, this work moves a big step toward achieving real implementations of the autonomous localization in practical industrial scenarios.
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Weicheng Guo, Chongjun Wu, Xiankai Meng, Chao Luo and Zhijian Lin
Molecular dynamics is an emerging simulation technique in the field of machining in recent years. Many researchers have tried to simulate different processing methods of various…
Abstract
Purpose
Molecular dynamics is an emerging simulation technique in the field of machining in recent years. Many researchers have tried to simulate different processing methods of various materials with the theory of molecular dynamics (MD), and some preliminary conclusions have been obtained. However, the application of MD simulation is more limited compared with traditional finite element model (FEM) simulation technique due to the complex modeling approach and long computation time. Therefore, more studies on the MD simulations are required to provide a reliable theoretical basis for the nanoscale interpretation of grinding process. This study investigates the crystal structures, dislocations, force, temperature and subsurface damage (SSD) in the grinding of iron-nickel alloy using MD analysis.
Design/methodology/approach
In this study the simulation model is established on the basis of the workpiece and single cubic boron nitride (CBN) grit with embedded atom method and Morse potentials describing the forces and energies between different atoms. The effects of grinding parameters on the material microstructure are studied based on the simulation results.
Findings
When CBN grit goes through one of the grains, the arrangement of atoms within the grain will be disordered, but other grains will not be easily deformed due to the protection of the grain boundaries. Higher grinding speed and larger cutting depth can cause greater impact of grit on the atoms, and more body-centered cubic (BCC) structures will be destroyed. The dislocations will appear in grain boundaries due to the rearrangement of atoms in grinding. The increase of grinding speed results in the more transformation from BCC to amorphous structures.
Originality/value
This study is aimed to study the grinding of Fe-Ni alloy (maraging steel) with single grit through MD simulation method, and to reveal the microstructure evolution within the affected range of SSD layer in the workpiece. The simulation model of polycrystalline structure of Fe-Ni maraging steel and grinding process of single CBN grit is constructed based on the Voronoi algorithm. The atomic accumulation, transformation of crystal structures, evolution of dislocations as well as the generation of SSD are discussed according to the simulation results.
Details
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Kanwal Jit Singh, Inderpreet Singh Ahuja and Jatinder Kapoor
This review paper reveals the literature on ultrasonic, chemical-assisted ultrasonic and rotary ultrasonic machining (USM) of glass material. The purpose of this review paper is…
Abstract
Purpose
This review paper reveals the literature on ultrasonic, chemical-assisted ultrasonic and rotary ultrasonic machining (USM) of glass material. The purpose of this review paper is to understand and describe the working principle, mechanism of material removal, experimental investigation, applications and influence of input parameters on machining characteristics. The literature reveals that the ultrasonic machines have been generally preferred for the glass and brittle work materials. Some other non-traditional machining processes may thermally damage the work surface. Through these USM, neither thermal effects nor residual stresses have been generated on the machined surface.
Design/methodology/approach
Various input parameters have the significant role in machine performance characteristics. For the optimization of output response, several input parameters have been critically investigated by the various researcher.
Findings
Some advance types of glasses such as polycarbonate bulletproof glass, acrylic heat-resistant glass and glass-clad polycarbonate bulletproof glass still need some further investigation because these materials have vast applications in automobile, aerospace and space industries.
Originality/value
Review paper will be beneficial for industrial application and the various young researcher. Paper reveals the detail literature review on traditional ultrasonic, chemical assisted ultrasonic and rotary USM of glass and glass composite materials.
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Chengguo Zong, Zhijian Ji, Junzhi Yu and Haisheng Yu
The purpose of this paper is to study the adaptability of the tracked robot in complex working environment. It proposes an angle-changeable tracked robot with human–robot…
Abstract
Purpose
The purpose of this paper is to study the adaptability of the tracked robot in complex working environment. It proposes an angle-changeable tracked robot with human–robot interaction in unstructured environment. The study aims to present the mechanical structure and human–robot interaction control system of the tracked robot and analyze the static stability of the robot working in three terrains, i.e. rugged terrain, sloped terrain and stairs.
Design/methodology/approach
The paper presents the mechanical structure and human–robot interaction control system of the tracked robot. To prevent the detachment of the tracks during obstacle navigation, a new type of passively adaptive device based on the relationship between the track’s variable angle and the forces is presented. Then three types of rough terrain are chosen to analyze the static stability of the tracked robot, i.e. rugged terrain, sloped terrain and stairs.
Findings
This paper provides the design method of the tracked robot. Owing to its appropriate dimensions, good mass distribution and limited velocity, the tracked robot remains stable on the complex terrains. The experimental results verify the effectiveness of the design method.
Originality/value
The theoretical analysis of this paper provides basic reference for the structural design of tracked robots.
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Chengguo Zong, Zhijian Ji and Haisheng Yu
This paper aims to provide a theoretical principle for the stability control of robot climbing stairs, autonomously based on human–robot interaction. Through this research…
Abstract
Purpose
This paper aims to provide a theoretical principle for the stability control of robot climbing stairs, autonomously based on human–robot interaction. Through this research, tracked mobile robots with human-robot interaction will be extensively used in rescue in disaster, exploration on planetary, fighting in battle, and searching for survivors in collapsed buildings.
Design/methodology/approach
This paper introduces the tracked mobile robot, based on human–robot interaction, and its six moving postures. The dynamic process of climbing stairs is analyzed, and the dynamic model of the robot is proposed. The dynamic stability criterion is derived when the tracked mobile robot contacts the stairs steps in one, two and more points. A further conduction of simulation on the relationship of the traction force and bearing force vs the velocity and acceleration in the three cases was carried out.
Findings
This paper explains that the tracked mobile robot, based on human–robot interaction, can stably climb stairs so long as the velocity and acceleration satisfy the dynamic stability criterion as noted above. In addition, the experiment tests the correctness of dynamic stability analysis when the tracked mobile robot contacts the stair steps in one, two or more points.
Originality/value
This paper provides the mechanical structure and working principle of the tracked mobile robot based on human–robot interaction and proposes an identification method of dynamic stability criterion when the robot contacts the stairs steps in one, two and more points.
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Daoyu Hu, Zhuyong Li, Zhiyong Hong and Zhijian Jin
The purpose of this paper is to analyze the influence of different types of winding configurations on the distribution of leakage field and branch currents for a 330-kVA…
Abstract
Purpose
The purpose of this paper is to analyze the influence of different types of winding configurations on the distribution of leakage field and branch currents for a 330-kVA high-temperature superconducting (HTS) transformer winding.
Design/methodology/approach
A three-dimensional electromagnetic model coupled with a circuit model validated by an experiment is developed to calculate the leakage field and current uniformity under four different types of secondary winding configurations. The four types of gaps between secondary windings are uniform gap, arithmetic progression (AP) gap, six sections with three different gaps and eight sections with four different gaps. A coefficient named as uneven degree is used to define the current nonuniformity.
Findings
The simulation results show that the currents and leakage field of double pancakes (DPs) on both sides are larger than those of the other DPs, and the currents of several middle DPs are smaller than the average rated current with an ISOB gap and larger than the average rated current with an IBOS gap. For any one of the four types of winding configurations, the type with the ISOB gap can prohibit the current nonuniformity more effectively, whereas the IBOS gap can decrease the leakage field more. The AP with the ISOB gap is a wise choice for decreasing the uneven degree and leakage field.
Practical implications
There is an optimal winding configuration for decreasing the leakage field and uneven degree of branch currents. The results and numerical model are very useful for the design of a HTS transformer.
Originality/value
The leakage field distribution and branch currents nonuniformity for 25 parallel DPs are investigated and optimized.
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Hongyu Duan, Qingtao Yu and Zhijian Wang
The purpose of this paper is to study the film-forming capacity of logarithmic crowned roller for tapered roller bearing (TRB) and to design a tapered roller profile based on an…
Abstract
Purpose
The purpose of this paper is to study the film-forming capacity of logarithmic crowned roller for tapered roller bearing (TRB) and to design a tapered roller profile based on an elastohydrodynamic lubrication model.
Design/methodology/approach
A coupled model, incorporating a quasi-static model of TRBs and an elastohydrodynamic lubrication model was developed to investigate the load distribution of TRB and to evaluate the lubrication state of tapered roller/raceway contact.
Findings
The model is verified with published literature results. Parametric analysis is conducted to investigate the effect of crown drop on azimuthal load distribution of the roller, film thickness and pressure distribution in the contact area. The result shows that crown drop has little influence on the azimuthal load distribution; also, the film thickness and the pressure distribution are asymmetric. When the tapered roller is designed and manufactured, the crown drop of the small end should be larger than that in the large end.
Originality/value
Precise roller profile design is conducive to improve the fatigue life of TRBs. Currently, most crown design methods neglect the influence of lubrication, which can lead to a non-suitable roller profile. Therefore, the present work is undertaken to optimize roller profiles based on lubrication theory.