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Article
Publication date: 8 May 2018

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…

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.

Details

Industrial Lubrication and Tribology, vol. 70 no. 4
Type: Research Article
ISSN: 0036-8792

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Article
Publication date: 8 January 2019

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.

Details

International Journal of Intelligent Computing and Cybernetics, vol. 12 no. 1
Type: Research Article
ISSN: 1756-378X

Keywords

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Article
Publication date: 19 May 2020

Hongling Guo and Keping Wu

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.

Details

China Finance Review International, vol. 10 no. 4
Type: Research Article
ISSN: 2044-1398

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Article
Publication date: 7 March 2008

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…

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.

Details

Industrial Lubrication and Tribology, vol. 60 no. 2
Type: Research Article
ISSN: 0036-8792

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Article
Publication date: 1 September 2016

Hai-ling Guan

With the development of social economy, the urbanization of the world has presented a new development trend. The green, ecological, and economic city has gradually…

Abstract

With the development of social economy, the urbanization of the world has presented a new development trend. The green, ecological, and economic city has gradually attracted people's attention. How to plan new cities and towns to coordinate economic development with nature has been the focus of domestic and foreign scholars. Based on this premise, this article elaborates the domestic and foreign research status of ecological city and puts forward a new type of green ecological civilization from the perspective of evolution of civilization. From the perspective of green ecological economy, the evolution of China's urban planning is studied in terms of the urban and rural areas, nature, pollution, industry, culture, and other aspects. To accumulate experience, green ecological planning in New York is also analyzed at multiple levels, such as urban expansion, energy, and urban water use. According to the development of our country in the past 30 years, the development strategy of urbanization suitable to China's national conditions is introduced on the basis of ecological economy. From the perspective of green ecological planning and economy, practice has proved that new urban planning is able to promote the establishment of a resource-saving society, to enhance the coordinated development of the population, resources, environment, and economy, and to comprehensively improve people's quality of life.

Details

Open House International, vol. 41 no. 3
Type: Research Article
ISSN: 0168-2601

Keywords

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Article
Publication date: 9 February 2015

Chiara Verbano and Maria Crema

Energy commodities are characterised by rigid demand and high price volatility, linked to many variables such as climate factors, exchange rates, availability of…

Abstract

Purpose

Energy commodities are characterised by rigid demand and high price volatility, linked to many variables such as climate factors, exchange rates, availability of resources. At the same time, the authorities often set prices, so wholesale energy companies need to create margins carefully by managing the procurement process and selecting appropriate tools to manage the risks associated with the volatility of energy prices. The purpose of this paper is to analyse and evaluate price and volume risks in the energy procurement process considering a “non-speculative” point of view, which is understudied in the literature review.

Design/methodology/approach

The paper adopts a quantitative approach to risk evaluation, based on accounting indicators, and applies it to a large Italian energy wholesale company.

Findings

A set of key risk indicators to measure price and volume risks is presented in the results, split into synthesis risk, unbalanced risks, modulation risks and risks derived from bilateral contracts. These indicators are applied to the case study, and each risk is prioritised and discussed.

Originality/value

This contribution is one of the first attempts to analyse energy procurement risks in a non-speculative approach. The proposed method allows: first, to evaluate and prioritise the three major types in the energy procurement process, second, to observe the trend of risk exposure, third, the performance measurement of the procurement process, and fourth, benchmarking activities if widely implemented in the energy sector.

Details

International Journal of Productivity and Performance Management, vol. 64 no. 2
Type: Research Article
ISSN: 1741-0401

Keywords

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Article
Publication date: 6 November 2018

Junqing Yang and Hong Chen

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…

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.

Details

Nankai Business Review International, vol. 10 no. 2
Type: Research Article
ISSN: 2040-8749

Keywords

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Article
Publication date: 30 January 2019

Erika A. Parn, David Edwards, Zainab Riaz, Fahad Mehmood and Joseph Lai

This paper aims to report upon the further development of a hybrid application programming interface (API) plug-in to building information modelling (BIM) entitled…

Abstract

Purpose

This paper aims to report upon the further development of a hybrid application programming interface (API) plug-in to building information modelling (BIM) entitled confined spaces safety monitoring system “CoSMoS”. Originally designed to engineer-out environmental hazards associated with working in a building’s confined spaces (during the construction phase of a building’s life-cycle), this second generation version is expanded upon to use archival records to proactively learn from data generated within a sensor network during the building’s operations and maintenance (O&M) phase of asset management (AM).

Design/methodology/approach

An applied research methodological approach adopted used a two-phase process. In phase one, a conceptual model was created to provide a “blueprint map” to integrate BIM, sensor-based networks and data analytics (DA) into one integral system. A literature review provided the basis for the conceptual model’s further development. In phase two, the conceptual model was transposed into the prototype’s development environment as a proof of concept using primary data accrued from a large educational building.

Findings

An amalgamation of BIM, historical sensor data accrued and the application of DA demonstrate that CoSMoS provides an opportunity for the facilities management (FM) team to monitor pertinent environmental conditions and human behaviour within buildings that may impact upon occupant/worker safety. Although working in confined spaces is used to demonstrate the inherent potential of CoSMoS, the system could readily be expanded to analyse sensor-based network’s historical data of other areas of building performance, maintenance and safety.

Originality/value

This novel prototype has automated safety applications for FM during the asset lifecycle and maintenance phase of a building’s O&M phase of AM. Future work is proposed in several key areas, namely, develop instantaneous indicators of current safety performance within a building; and develop lead indicators of future safety performance of buildings.

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Article
Publication date: 24 September 2019

Madjid Tavana and Vahid Hajipour

Expert systems are computer-based systems that mimic the logical processes of human experts or organizations to give advice in a specific domain of knowledge. Fuzzy expert…

Abstract

Purpose

Expert systems are computer-based systems that mimic the logical processes of human experts or organizations to give advice in a specific domain of knowledge. Fuzzy expert systems use fuzzy logic to handle uncertainties generated by imprecise, incomplete and/or vague information. The purpose of this paper is to present a comprehensive review of the methods and applications in fuzzy expert systems.

Design/methodology/approach

The authors have carefully reviewed 281 journal publications and 149 conference proceedings published over the past 37 years since 1982. The authors grouped the journal publications and conference proceedings separately accordingly to the methods, application domains, tools and inference systems.

Findings

The authors have synthesized the findings and proposed useful suggestions for future research directions. The authors show that the most common use of fuzzy expert systems is in the medical field.

Originality/value

Fuzzy logic can be used to manage uncertainty in expert systems and solve problems that cannot be solved effectively with conventional methods. In this study, the authors present a comprehensive review of the methods and applications in fuzzy expert systems which could be useful for practicing managers developing expert systems under uncertainty.

Details

Benchmarking: An International Journal, vol. 27 no. 1
Type: Research Article
ISSN: 1463-5771

Keywords

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Article
Publication date: 16 December 2019

Linhui Wang, Jing Zhao, Jia Sun and Zhiqing Dong

The purpose of this paper is to examine the effect of biased technology on employment distribution and labor status in income distribution of China. It also testifies a…

Abstract

Purpose

The purpose of this paper is to examine the effect of biased technology on employment distribution and labor status in income distribution of China. It also testifies a threshold effect of the capital per labor and employment distribution on labor status from biased technology.

Design/methodology/approach

This paper presents a normalized supply-side system of three equations to measure the bias of technology in China. Linear and threshold regressions approaches are applied over cross-province panel data to investigate the influence which biased technology has on labor status under different capital per labor and employment distribution regimes.

Findings

This paper empirically shows that technology has been mostly capital-biased in China. The regression results indicate that capital-biased technology impairs labor income status and tend to modify employment distribution and labor income between industries. Furthermore, it reveals the threshold effect of capital per labor and employment distribution on the relationship between biased technology and labor status.

Originality/value

This paper extends the literature by explaining labor status from the perspective of biased technology and the effect of inter-industry employment distribution in China. It further explores the asymmetric effect of biased technology on labor productivity and income, which promotes inter-industry labor mobility and modifies employment distribution. This paper highlights the implications of this explanation for labor relations and human resource management.

Details

Chinese Management Studies, vol. 14 no. 1
Type: Research Article
ISSN: 1750-614X

Keywords

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