Tao Han, Bo Xiao, Xi-Sheng Zhan, Jie Wu and Hongling Gao
The purpose of this paper is to investigate time-optimal control problems for multiple unmanned aerial vehicle (UAV) systems to achieve predefined flying shape.
Abstract
Purpose
The purpose of this paper is to investigate time-optimal control problems for multiple unmanned aerial vehicle (UAV) systems to achieve predefined flying shape.
Design/methodology/approach
Two time-optimal protocols are proposed for the situations with or without human control input, respectively. Then, Pontryagin’s minimum principle approach is applied to deal with the time-optimal control problems for UAV systems, where the cost function, the initial and terminal conditions are given in advance. Moreover, necessary conditions are derived to ensure that the given performance index is optimal.
Findings
The effectiveness of the obtained time-optimal control protocols is verified by two contrastive numerical simulation examples. Consequently, the proposed protocols can successfully achieve the prescribed flying shape.
Originality/value
This paper proposes a solution to solve the time-optimal control problems for multiple UAV systems to achieve predefined flying shape.
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Juan Chen, Hongling Guo and Zuoping Xiao
This study aims to investigate how high-speed railway (HSR) development affects urban construction investment (UCI) bond yield spreads based on China’s background.
Abstract
Purpose
This study aims to investigate how high-speed railway (HSR) development affects urban construction investment (UCI) bond yield spreads based on China’s background.
Design/methodology/approach
This study constructs a quasi-natural experiment and adopts regression analyses to empirically examine the relation between HSR development and UCI bond yield spreads. The empirical analysis is based on a Chinese sample of 15,109 bond offering observations from 2008 to 2019.
Findings
The results show that HSR development reduces UCI bond yield spreads. Mechanistic analysis shows that HSR development increases land prices and the level of urbanization, which in turn lowers the UCI bond yield spreads. In addition, the impact of HSR development on UCI bond yield spreads is more significant at higher marketization levels and lower degrees of dependence on land finance cities where UCI corporations are located.
Research limitations/implications
The results imply that transportation infrastructure improvement, such as HSR development, helps to enhance the credit of local governments and the solvency of UCI corporations and ultimately reduces the financing cost of UCI bonds.
Originality/value
This paper provides theoretical support and empirical evidence for the impact of transportation infrastructure construction on the implicit debt risks of local governments in China, which enriches the research on the “HSR economy” from a micro perspective and expands the research on the influencing factors of local governments’ debt risk.
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This study aims to investigate how opening high-speed railways affects the cost of debt financing based on China's background.
Abstract
Purpose
This study aims to investigate how opening high-speed railways affects the cost of debt financing based on China's background.
Design/methodology/approach
Using panel data on Chinese listed firms from 2008 to 2017, this study constructs a quasi-natural experiment and adopts a difference-in-difference model with multiple time periods to empirically examine the relation between the high-speed railway openings and debt financing cost.
Findings
Our results show that opening high-speed railways reduces the cost of debt financing, and this negative correlation is more significant in non-state firms, firms with weaker internal control, and firms that hire non-Big Four auditors. Besides, we explore the impact mechanisms and find that opening high-speed railways improves analyst attention, institutional investor participation, and information disclosure quality, which in turn lowers the cost of debt financing.
Research limitations/implications
The results imply that the opening of high-speed railways helps to alleviate the information asymmetry and adverse selection between firms and creditors and ultimately reduces the cost of corporate debt financing.
Practical implications
This paper can inform firms and stakeholders about the impact of opening high-speed railways on debt financing cost: it improves the information environment, reduces the geographical location restrictions of debt financing, ensures the reasonable pricing of corporate debt, and thus promotes the healthy and sound development of the debt market.
Originality/value
This paper provides theoretical support and empirical evidence for the impact of infrastructure construction on the information environment of the debt market in China, which enriches the research on the “high-speed railway economy.” In addition, as an exogenous event, the opening of high-speed railways instantly shortens the time distance between firms and external stakeholders, which gives us a natural environment to conduct empirical research, thus providing a new perspective for financial research on firms' geographical location.
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Bing Shi, Dan Zhang, Hongling Xie and Yinghui Zhou
This study aims to examine factors affecting Chinese adolescents’ purchase intention for local brands; this study focuses on the effects of perceived social status value and…
Abstract
Purpose
This study aims to examine factors affecting Chinese adolescents’ purchase intention for local brands; this study focuses on the effects of perceived social status value and materialistic values.
Design/methodology/approach
A theoretical model relating perceived social status value of brands to purchase intention, including materialistic values as a moderator, was developed and tested, using a sample of 587 Chinese adolescent respondents. Another experimental study examined the variability of the moderation of materialistic values across different levels of peer pressure in a product usage occasion.
Findings
Perceived social status value associated with local and foreign brands significantly influences purchase intention for local brands. Moreover, influence of perceived social status value of local versus foreign brands on local brand purchase intention is greater for materialistic adolescents. Additionally, the moderation of materialistic values is found in a product usage occasion with high peer pressure, but not in an occasion with low peer pressure.
Research limitations/implications
The findings show that perceived social status value associated with brands shapes purchase intention for local brands. The moderating effect of materialistic values is complex and suggests further research. The study’s scope is limited to Chinese adolescents.
Practical implications
The findings provide understanding of the drivers of purchase intention, and thus serve as a guideline for Chinese firms and foreign marketers seeking to enter the growing Chinese market, as well as consumer educators in China.
Originality/value
This study contributes to the limited empirical research into the factors shaping country-of-origin effects. Moreover, the findings suggest the need to consider the moderating role of materialistic values on purchase intention for local brands.
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Hongling Yi, Kunyang Dang, Xiangqiong Zeng, Heyang Shao and Tianhui Ren
This paper sets out to study tribological properties, anticorrosive performances and thermal stabilities of two novel S‐N type triazinyl‐containing polysulfides…
Abstract
Purpose
This paper sets out to study tribological properties, anticorrosive performances and thermal stabilities of two novel S‐N type triazinyl‐containing polysulfides {Bis[2,4‐bis(diethylamino)‐s‐triazin‐6‐yl] polysulfide (BBET‐PS) and Bis[2,4‐bis(di‐n‐butylamino)‐s‐triazin‐6‐yl] polysulfide (BBBT‐PS)} as additives in biodegradable grease, and to estimate the tribochemical mechanism.
Design/methodology/approach
Extreme pressure (EP) and anti‐wear (AW) properties of two compounds at different addition concentration were evaluated using a four‐ball machine. Their wear scar was analyzed with X‐ray photoelectron spectroscopy (XPS) and a scanning electron microscope.
Findings
Two novel S‐N type triazinyl‐containing polysulfides possess excellent load‐carrying capacity, good AW and show good corrosion‐inhibiting performance. The thermal stability of BBB‐PS is better than that of BBE‐PS. According to the XPS results, the triazinyl‐containing polysulfides react with the metal to generate a surface protective film consisting of sulfate, FeS and absorbed compounds containing organic‐N.
Research limitations/implications
The antioxidant and biodegradability of the two novel compounds were not investigated.
Practical implications
Two effective EP and AW additives were synthesized, and maybe potentially industrial applied lubricating grease additives.
Originality/value
The achievement of this study is the synthesis of two triazinyl‐containing polysulfides, which can be effective additives to improve the tribological performance of biodegradable grease.
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Xiangqiong Zeng, Hongling Yi, Hua Wu, Jing Li, Tianhui Ren, Weimin Liu and Zhongyi He
This paper seeks to study the tribological properties, corrosion inhibition properties and action mechanism of two triazine‐containing disulfides, TOSS and TOMA, as additives in…
Abstract
Purpose
This paper seeks to study the tribological properties, corrosion inhibition properties and action mechanism of two triazine‐containing disulfides, TOSS and TOMA, as additives in combustion engine base oil (5CST); those properties of an alkyl disulfide dodecyl disulfide and zinc dialkyldithiophosphate (ZDDP) were also evaluated for comparison to discover whether these additives could be used as potential substitute candidates for ZDDP.
Design/methodology/approach
Their tribological performances were evaluated using a four‐ball machine. The worn surfaces were investigated by scanning electron microscopy and X‐ray photoelectron spectroscopy (XPS)
Findings
The three additives have good load‐carrying capacity and corrosion inhibition properties comparable with those of ZDDP. The anti‐wear properties of the triazine‐containing disulfides TOSS and TOMA are good but a little inferior to those of ZDDP. The friction‐reducing performances of the additives are better than those of ZDDP. The XPS results show that absorption and tribochemical reactions occur to generate a complex boundary lubrication films comprising inorganic sulfate, sulfide, iron oxide and organic nitrogen, and sulfur‐containing compounds.
Research limitations/implications
The anti‐oxidation properties are still to be estimated, and the synergistic effectiveness with other additives could be demonstrated.
Practical implications
These additives are good extreme pressure and anti‐wear additives in combustion engine base oil and, through further modification of molecular structure or combination with other additives, they may be a potential replacement for ZDDP.
Originality/value
To reduce the cost, the products synthesized were not finely separated. Their tribological properties as additives in the widely used combustion engine base oil were first investigated and results indicate that they show excellent performances.
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Ting Huang, Heng Li, Hongling Guo, Neo Chan, Stephen Kong, Greg Chan and Martin Skitmore
The introduction of Building Information Model (BIM) tools over the last 20 years is resulting in radical changes in the architectural, engineering and construction industry. One…
Abstract
Purpose
The introduction of Building Information Model (BIM) tools over the last 20 years is resulting in radical changes in the architectural, engineering and construction industry. One of these changes concerns the use of virtual prototyping – an advanced technology integrating BIM with realistic graphical simulations. Construction virtual prototyping (CVP) has now been developed and implemented on ten real construction projects in Hong Kong in the past three years. The purpose of this paper is to report on a survey aimed at establishing the effects of adopting this new technology and obtaining recommendations for future development.
Design/methodology/approach
A questionnaire survey was conducted in 2007 of 28 key participants involved in four major Hong Kong construction projects – these projects being chosen because the CVP approach is used in more than one stage in each project. In addition, several interviews are conducted with the project manager, planning manager and project engineer of an individual project.
Findings
All the respondents and interviewees give a positive response to the CVP approach, with the most useful software functions considered to be those relating to visualisation and communication. The CVP approach is thought to improve the collaboration efficiency of the main contractor and sub‐contractors by approximately 30 percent, and with a concomitant 30 to 50 percent reduction in meeting time. The most important benefits of CPV in the construction planning stage are the improved accuracy of process planning and shorter planning times, while improved fieldwork instruction and reducing rework occur in the construction implementation stage. Although project teams are hesitant to attribute the use of CVP directly to any specific time savings, it is also acknowledged that the workload of project planners is decreased. Suggestions for further development of the approach include incorporation of automatic scheduling and advanced assembly study.
Originality/value
Whilst the research, development and implementation of CVP is relatively new in the construction industry, it is clear from the applications and feedback to date that the approach provides considerable added value to the organisation and management of construction projects.
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Aibin Zhu, Hongling Wu, Yulei Yang and Shengli He
Because of the various geometric descriptions of different bearing types, performance calculation of journal bearing is complicated, and is difficult in traditional model. This…
Abstract
Purpose
Because of the various geometric descriptions of different bearing types, performance calculation of journal bearing is complicated, and is difficult in traditional model. This paper aims to simplify the calculation of the journal bearing performance, and to reduce the workload.
Design/methodology/approach
On the basis of previous research, a general performance calculation model of journal bearing is proposed in this paper. Eccentricity ratio and attitude angle of axis to each pad are calculated by coordinates of spindle center and each pad center by establishing the unified coordinate system. The surface deformation of journal bearing is taken into consideration, and a correction value is added to the dimensionless oil film thickness.
Findings
The performance calculation results of various fix-pad and tilting-pad journal bearings match the results of the existing references very well, revealing the validity of the model. The general model can greatly reduce programming workload, and increase adaptability to different bearings.
Originality/value
Geometric descriptions of both fix-pad and tilting-pad journal bearings are unified in this model, which can be applied to both standard and non-standard journal bearings with different preload ratios. In addition, due to the unification of different bearings types, this model is more conducive to performance comparison among different bearing types, and promotes the development of new structural forms for journal bearings.
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This paper aims to examine whether rewards incentives of non-state-owned enterprises can settle the matters of motivation lack, strained labor relations and frequent labor-capital…
Abstract
Purpose
This paper aims to examine whether rewards incentives of non-state-owned enterprises can settle the matters of motivation lack, strained labor relations and frequent labor-capital conflicts and realize co-win cooperation of workers, enterprises and the society.
Design/methodology/approach
Based on the data of 1,617 questionnaires in 257 enterprises, this research reveals the total rewards factors that affect the labor motivation of non-stated-owned enterprises in China and improve labor productivity by adopting the hierarchical linear regression analysis and multi-group path analysis, and establishes a new model of win-win cooperation between labor and capital and the society through the incentive function of these elements by stimulating the enthusiasm of workers, improving labor productivity, increasing profits, expanding capital accumulation and absorbing labor force.
Findings
The authors have discovered that in general the main incentives that stimulate the enthusiasm of employees are the factors of performance and recognition and development and career opportunity in total rewards. The factor of benefits also has a significant incentive effect on employees in the western area of China, migrant workers with lower education and male employees, but negative effect on the post-1990s employees in non-state-owned enterprises. However, the compensation factor should be used with caution when encouraging employees in eastern region and the post-1980s. The total rewards factors of development and career opportunities and the performance and the recognition and benefits should be used to motivate workers to improve labor productivity, increase corporate profits and absorb more labor force, which is a long-term solution to win-win cooperation between labor and capital and social sustainable development. It is an important way to increase profits and absorb more labor force by increasing employee’s human capital investment and improving labor proficiency of employees under age 45. The conclusions provide new effective management methods for non-state-owned enterprises in China.
Practical implications
As a consequence, it will encourage employees to improve labor productivity and increase profits and thus absorb more labor force, if we use these factors of performance and recognition, development and career opportunity and benefits integratedly, we will find a permanent solution that the two sides of the labor and management and the society enjoy a win-win cooperation.
Originality/value
The research will provide theoretical basis for non-state-owned enterprises to apply a new and effective management style so that we can establish a win-win cooperation between the labor and management. What’s more, the research will develop the Dual Economy Theory of Lewis and the employment theory of Keynes and will also provide a theoretical basis for the realization of Taylor’s harmonious industrial relations.
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Lijun Dong, Naichao Chen, Jiawen Liang, Tingting Li, Zhanlin Yan and Bing Zhang
The purpose of this study is to provide an in-depth understanding about the indoor-orbital electrical inspection robot, which is useful for motivating the further investigation on…
Abstract
Purpose
The purpose of this study is to provide an in-depth understanding about the indoor-orbital electrical inspection robot, which is useful for motivating the further investigation on the inspection of electrical equipment. Currently, electric energy has a strong correlation with the economic development of the country. Intelligent substations play an important role in the transmission and distribution of the electricity; the maintenance of the substation has attracted intensive attention due to the requirement of reliability and safety. The indoor-orbital electrical inspection robot has increasingly become the main tool to realize the unmanned. Hence, a systematic review is conducted systematically reviewing the current technical status of the indoor-orbital electrical inspection robot and discuss the existed problems.
Design/methodology/approach
In this paper, the most essential achievements in the field of indoor-orbital electrical inspection robots were reported to present the current status, and the mechanical structures and key inspective technologies were also discussed.
Findings
Four recommendations are provided from the analyzed review, which have made constructive comments on the overall structural design, functionality, intelligence and future development direction of the indoor-orbital electrical inspection robot, respectively.
Originality/value
To the best of the authors’ knowledge, this is the first systematic review study on indoor-orbital electrical inspection robots; it fills the theoretical gap and proffers design ideas and directions for the development of the indoor-orbital electrical inspection robot.