Wei Li, Yuxin Huang, Leilei Ji, Lingling Ma and Ramesh Agarwal
The purpose of this study is to explore the transient characteristics of mixed-flow pumps during startup process.
Abstract
Purpose
The purpose of this study is to explore the transient characteristics of mixed-flow pumps during startup process.
Design/methodology/approach
This study uses a full-flow field transient calculation method of mixed-flow pump based on a closed-loop model.
Findings
The findings show the hydraulic losses and internal flow characteristics of the piping system during the start-up process.
Research limitations/implications
Large computational cost.
Practical implications
Improve the accuracy of current numerical simulation results in transient process of mixed-flow pump.
Originality/value
Simplify the setting of boundary conditions in the transient calculation.
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Lida Wang, Xian Rong and Lingling Mu
This study aims to investigate the basic public service level in the Beijing-Tianjin-Hebei region under the impact of COVID-19.
Abstract
Purpose
This study aims to investigate the basic public service level in the Beijing-Tianjin-Hebei region under the impact of COVID-19.
Design/methodology/approach
This study constructed a basic public service-level evaluation system from the five dimensions of education, culture, health, social security and infrastructure and environment, and measures the basic public service level in 13 cities in Beijing, Tianjin and Hebei using the entropy method. The spatial pattern and dynamic evolution of the public service level are analysed from the perspective of dynamic trends in time series and spatial distribution, along with the reasons for the evolution of spatial distribution.
Findings
(1) The basic public service level in the 13 cities is generally on the rise, but the trend is unstable. (2) The basic public service level in space shows a general trend of attenuation from northeast to southwest, with significant spatial imbalance and orientation. (3) The regional differences first increase and then decrease. (4) The inter-group mobility of different basic public service levels is low, and cities with lower initial levels find it difficult to achieve leapfrog development. Moreover, the health service level of the region is still at a low stage, which is not conducive to effectively preventing and controlling the epidemic.
Originality/value
From the perspective of this research, the spatial pattern and dynamic evolution of basic public service were adopted to analyse the coordinated development of the Beijing-Tianjin-Hebei region. Furthermore, this study discusses how to improve the basic public service level to ensure sustainable operation in the region under the impact of COVID-19.
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Honghao Tang, Qi Yue, Chen Wang, Lingling Zhou, Jing Yu, Wen Wu, Ruoyan Feng and Chen Ma
The major marine functional zoning plan (MMFZP) and marine functional zoning (MFZ) are two important kinds of marine spatial planning (MSP) in China. Their developing and…
Abstract
Purpose
The major marine functional zoning plan (MMFZP) and marine functional zoning (MFZ) are two important kinds of marine spatial planning (MSP) in China. Their developing and implementation are integral to rational marine utilization and sustainable marine development. The purpose of this research is to study how these two kinds of MSP work in coordination in China.
Design/methodology/approach
This paper reviewed the present status of MSP research in China and abroad and presented a comparative study of the MMFZP and MFZ from different aspects, analyzing the relationship between the two.
Findings
The study found obvious differences between the MMFZP and MFZ, with respect to their concept and connotation, purpose and goal, as well as zoning methods and zoning functions. MFZ provides reference with respect to data, zoning methods and partial zoning results for the MMFZP, which in turn takes measures for addressing issues faced by MFZ and promotes the national MSP work.
Originality/value
In the process of developing and implementing the two zoning plans, this paper emphasizes the necessity to strengthen data sharing, reference of zoning techniques and coordination in zoning work, which will help to improve China's marine spatial management.
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Pengyue Guo, Zhijing Zhang, Lingling Shi and Yujun Liu
The purpose of this study was to solve the problem of pose measurement of various parts for a precision assembly system.
Abstract
Purpose
The purpose of this study was to solve the problem of pose measurement of various parts for a precision assembly system.
Design/methodology/approach
A novel alignment method which can achieve high-precision pose measurement of microparts based on monocular microvision system was developed. To obtain the precise pose of parts, an area-based contour point set extraction algorithm and a point set registration algorithm were developed. First, the part positioning problem was transformed into a probability-based two-dimensional point set rigid registration problem. Then, a Gaussian mixture model was fitted to the template point set, and the contour point set is represented by hierarchical data. The maximum likelihood estimate and expectation-maximization algorithm were used to estimate the transformation parameters of the two point sets.
Findings
The method has been validated for accelerometer assembly on a customized assembly platform through experiments. The results reveal that the proposed method can complete letter-pedestal assembly and the swing piece-basal part assembly with a minimum gap of 10 µm. In addition, the experiments reveal that the proposed method has better robustness to noise and disturbance.
Originality/value
Owing to its good accuracy and robustness for the pose measurement of complex parts, this method can be easily deployed to assembly system.
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Hongquan Zhu and Lingling Jiang
Merton’s model of capital market equilibrium under incomplete information predicts that contemporaneous stock returns are positively related to investor recognition and that…
Abstract
Purpose
Merton’s model of capital market equilibrium under incomplete information predicts that contemporaneous stock returns are positively related to investor recognition and that future stock returns are negatively related to investor recognition. The purpose of this paper is to empirically investigate whether Merton’s theory holds true for the Chinese stock market.
Design/methodology/approach
This paper proposes the degree of shareholder base growth (SBG) as a proxy for investor recognition and examines the relationship between investor recognition and stock returns through a univariate analysis and Fama-Macbeth cross-sectional regressions based on A-Share listed firms.
Findings
The results show that investor recognition is nonlinearly and positively related to contemporaneous stock returns and is negatively related to future stock returns in contrast to the conclusions of Merton’s theory. A long-short trading strategy that involves buying stocks with the lowest SBG rate and that sells stocks with the highest SBG rate will earn an average monthly return of 3.615 percent.
Research limitations/implications
Though Merton’s theory is not fully reflected in the Chinese stock market, investor recognition is considered an important risk factor in the Chinese stock market.
Originality/value
No works have yet investigated the validity of Merton’s “investor cognition hypothesis” in relation to the Chinese stock market. This paper strives to fill this gap.
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Lingling Zhang, Chang Gao and Yoshiteru Nakamori
This study aims to explore the knowledge spillover mechanism in big science projects (BSP) from an institutional perspective by elaborating on the dynamic relationship between…
Abstract
Purpose
This study aims to explore the knowledge spillover mechanism in big science projects (BSP) from an institutional perspective by elaborating on the dynamic relationship between institutional dualism and legitimacy.
Design/methodology/approach
The study conducts an exploratory research and adopts the grounded theory methodology in the context of BSP. Data draw mainly upon nine semi-structured interviews.
Findings
The knowledge spillovers in BSP are driven by institutions, which work through mechanisms of legitimacy perception. Formal and informal institutions influence organizational and individual behavior through legitimacy pressure and support. Formal institutions impose legitimacy pressure on organizations and individuals, forcing them to cooperate closely to solve problems; informal institutions enable them to adopt innovative strategies and positive attitudes through legitimacy support; all these promote knowledge spillovers in research and development (R&D) activities, engineering practice and regional interaction. Knowledge spillovers enable stakeholders to realize their R&D advancement, manufacturing promotion and management sophistication. Further, regional knowledge diffusion and culture transmission promote regional innovation and social capital accumulation.
Research limitations/implications
The study develops a theoretical model that shows how knowledge spillover mechanisms happen in BSP from an institutional perspective (the trigger, the channels/process and the impacts). More specifically, this explanation is provided by explaining how formal and informal institutions influence organizational and individual behavior through legitimacy perceptions.
Practical implications
First, policymakers should recognize and value the guiding, supporting and coordinating role of formal institutions and enrich capital forms to release the legitimacy pressure of stakeholders. Second, management of BSP needs to be capable of coordinating stakeholder relationships and interactions, while management should focus their attention on fostering good organizational routines and shared group value. Third, the local culture and customs should be taken into consideration since it can be an enabling or constraining of BSP. Finally, industries can take advantage of the opportunity to coordinate their R&D efforts to gain competitiveness.
Originality/value
First, the authors introduce the institutional perspective to analyze the construction process of BSP, which helps to better understand the interactions of stakeholders under the influence of institutions, the dynamic process and impacts of knowledge spillovers. Second, the authors are committed to contributing to the development of knowledge spillover theories by adopting an institutional perspective. The authors furthermore explore and propose the presence of a dynamic mechanism between institutional dualism and knowledge spillovers. In consequence, the authors introduce the concept of legitimacy perceptions, which is a bridge to understanding the interaction between them. Third, by explicitly discussing the actual meaning of our framework, the authors explore the unique potential of institutional arrangement in promoting the knowledge management of complex cross-border cooperation, while seeking to promote its management and administrative practices.
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Lingling Pei, Qin Li and Zhengxin Wang
The purpose of this paper is to propose a new method based on nonlinear least squares (NLS) for solving the parameters of nonlinear grey Bernoulli model (NGBM(1,1)) and to verify…
Abstract
Purpose
The purpose of this paper is to propose a new method based on nonlinear least squares (NLS) for solving the parameters of nonlinear grey Bernoulli model (NGBM(1,1)) and to verify the proposed model using the case of employee demand prediction of high-tech enterprises in China.
Design/methodology/approach
First of all, minimising the square sum of fitting error of grey differential equation of NGBM(1,1) is taken as the optimisation target and the parameters of classic grey model (GM(1,1)) are set as the initial value of parameter vector. Afterwards, the structural parameters and power exponents are solved by using the Gauss-Newton iteration algorithm so as to calculate the parameters of NGBM(1,1) under given rules for ceasing the algorithm. Finally, by taking the employee demand of high-tech enterprises in the state-level high-tech industrial development zone in China as examples, the validity of the new method is verified.
Findings
The results show that the parameter estimation algorithm based on the NLS method can effectively identify the power exponents of NGBM(1,1) and therefore can favourably adapt to the nonlinear fluctuations of sequences. In addition, the algorithm is superior to the GM(1,1) model, grey Verhulst model, and Quadratic-Exponential smoothing algorithm in terms of the simulation and prediction accuracy.
Research limitations/implications
Under the framework of solving parameters based on NLS, various aspects of NGBM(1,1) remain to be further investigated including background value, initial condition and variable structural modelling methods.
Practical implications
The parameter estimation algorithm based on NLS can effectively identify the power exponent of NGBM(1,1) and therefore it can favourably adapt to the nonlinear fluctuation of sequences.
Originality/value
According to the basic principle of NLS, a new method for solving the parameters of NGBM(1,1) is proposed by using the Gauss-Newton iteration algorithm. Moreover, by conducting the modelling case about employees demand in high-tech enterprises in China, the effectiveness and superiority of the new method are verified.
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Qian Xu, Yuhui Wu and Lingling Zhai
The purpose of this paper is to examine how credit ratings affect corporate financial behavior from the perspective of merger and acquisition (M&A) decisions. The goal is to test…
Abstract
Purpose
The purpose of this paper is to examine how credit ratings affect corporate financial behavior from the perspective of merger and acquisition (M&A) decisions. The goal is to test the financing and supervisory effects of credit ratings and study the economic consequences of credit ratings in the context of China.
Design/methodology/approach
Using a sample of Chinese A-share listed companies over the 2008–2017 period, this paper empirically examines the effect of credit ratings on firms’ M&A decisions. The authors used a probit model for regression when they tested the effect of credit rating on M&A likelihood and a tobit model when they tested the effect of credit rating on M&A intensity.
Findings
First, rated enterprises tend to make more acquisitions compared with non-rated enterprises, consistent with the hypothesis that credit ratings alleviate financing constraints. Second, high-rated enterprises are more cautious toward M&As due to concerns about preserving their ratings, which indicates that credit ratings also play a supervisory role in the M&A process. Additional tests show that enterprises reduce M&A activity after a rating downgrade to avoid further deterioration in their ratings; this further supports the supervisory role of credit ratings.
Originality/value
This paper adds incremental evidence to the literature on the impact of credit ratings on corporate financial behavior and extends the literature on the factors influencing M&As. The authors provided empirical evidence from emerging capital markets for the financing and supervisory effects of credit ratings and provided theoretical guidance for promoting the stable, long-term development of China’s credit rating industry.
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Obadia Kyetuza Bishoge, Lingling Zhang, Witness Gerald Mushi and Nametso Matomela
This paper aims to analyze the context of community opinions and participation in the natural gas sector in developing countries, a case study of Tanzania. To achieve this…
Abstract
Purpose
This paper aims to analyze the context of community opinions and participation in the natural gas sector in developing countries, a case study of Tanzania. To achieve this purpose, the study pointed out six facts, namely, information on the natural gas sector; awareness of the natural gas-related policies; laws and regulations and the creation of employment opportunities; local experts in the natural gas sector; the use of natural gas revenues; and natural gas for poverty reduction and improvement of social well-being.
Design/methodology/approach
The study is a systematic review of the literature on community participation based on the relevant studies published between 2010 and 2018. A comprehensive literature review was carried out following the seven-step model whereby relevant themes from different potential bibliographic databases such as Google Scholar were systematically selected, compiled and analyzed using descriptive methods.
Findings
The study revealed that despite the various efforts made by the governments and other stakeholders to promote community participation, there is an inadequate level of community participation in the natural gas sector in developing countries. There are limited local experts for natural gas operations and low transparency on natural gas contracts, agreements and revenues. Therefore, there is the need to raise awareness for a highly informed society with a clear sense of ownership of the natural gas wealth among the local communities. Moreover, transparency and accountability are recommended for the sustainable natural gas sector development.
Originality/value
This paper offers new and current cross-sectoral inclusion, opinions, hopes and concerns of the community on the natural gas sector management in developing countries.
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Zhiqiang Geng, Lingling Liang, Yongming Han, Guangcan Tao and Chong Chu
Food safety risk brought by environmental pollution seriously threatens human health and affects national economic and social development. In particular, heavy metal pollution and…
Abstract
Purpose
Food safety risk brought by environmental pollution seriously threatens human health and affects national economic and social development. In particular, heavy metal pollution and nutrient deficiency have caused regional diseases. Thus, the purpose of this paper is to present a risk early warning method of food safety considering environmental and nutritional factors.
Design/methodology/approach
A novel risk early warning modelling method based on the long short-term memory (LSTM) neural network integrating sum product based analytic hierarchy process (AHP-SP) is proposed. The data fuzzification method is adopted to overcome the uncertainty of food safety detection data and the processed data are viewed as the input of the LSTM. The AHP-SP method is used to fuse the risk of detection data and the obtained risk values are viewed as the expected output of the LSTM. Finally, the proposed method is applied on one group of sterilized milk data from a food detection agency in China.
Findings
The experimental results show that compared with the back propagation and the radial basis function neural networks, the proposed method has higher accuracy in predicting the development trend of food safety risk. Moreover, the causal factors of the risk can be figured out through the predicted results.
Originality/value
The proposed modelling method can achieve accurate prediction and early warning of food safety risk, and provide decision-making basis for the relevant departments to formulate targeted risk prevention and control measures, thereby avoiding food safety incidents caused by environmental pollution or nutritional deficiency.