Min Wang, Y.T. Feng, Ting T. Zhao and Yong Wang
Sand production is a challenging issue during hydrocarbon production in the oil and gas industry. This paper aims to investigate one sand production process, i.e. transient sand…
Abstract
Purpose
Sand production is a challenging issue during hydrocarbon production in the oil and gas industry. This paper aims to investigate one sand production process, i.e. transient sand production, using a novel bonded particle lattice Boltzmann method. This mesoscopic technique provides a unique insight into complicated sand erosion process during oil exploitation.
Design/methodology/approach
The mesoscopic fluid-particle coupling is directly approached by the immersed moving boundary method in the framework of lattice Boltzmann method. Bonded particle method is used for resolving the deformation of solid. The onset of grain erosion of rocks, which are modelled by a bonded particle model, is realised by breaking the bonds simulating cementation when the tension or tangential force exceeds critical values.
Findings
It is proved that the complex fluid–solid interaction occurring at the pore/grain level can be well captured by the immersed moving boundary scheme in the framework of the lattice Boltzmann method. It is found that when the drawdown happens at the wellbore cavity, the tensile failure area appears at the edge of the cavity. Then, the tensile failure area gradually propagates inward, and the solid particles at the tensile failure area become fluidised because of large drag forces. Subsequently, some eroded particles are washed out. This numerical investigation is demonstrated through comparison with the experimental results. In addition, through breaking the cementation, which is simulated by bond models, between bonded particles, the transient particle erosion process is successfully captured.
Originality/value
A novel bonded particle lattice Boltzmann method is used to investigate the sand production problem at the grain level. It is proved that the complex fluid–solid interaction occurring at the pore/grain level can be well captured by the immersed moving boundary scheme in the framework of the lattice Boltzmann method. Through breaking the cementation, which is simulated by bond models, between bonded particles, the transient particle erosion process is successfully captured.
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Ting Li, Xinlei Zhao and Aiwu Zhao
Motivated by managers’ intentions to pursue private interests by engaging in earnings management, this paper aims to investigate whether voting with hands (shareholders cast votes…
Abstract
Purpose
Motivated by managers’ intentions to pursue private interests by engaging in earnings management, this paper aims to investigate whether voting with hands (shareholders cast votes on shareholder proposals) by shareholders acts as an external disciplining mechanism over earnings management relative to corporate governance. Also, as corporate governance can scrutinize managers’ behavior, this study also examines whether there is a substitutive relation between shareholder proposals and corporate governance mechanism.
Design/methodology/approach
First, this paper uses ordinary least squares (OLS) regressions of discrepancy accruals on the percentage of “For” votes for shareholder proposals to test the incremental effect of shareholder proposals on earnings management. Second, firms receiving shareholder proposals are matched with those not receiving proposals by propensity scores, and the levels of earnings management and corporate governance between these two groups are compared by univariate analysis and OLS regressions. In addition, six portfolios are created based on whether firms receive shareholder proposals, as well as on the levels of corporate governance, to assess whether external control from shareholder proposals can substitute internal control for corporate governance in disciplining earnings management. Regressions of earnings management on corporate governance (shareholder proposals) are conducted in the sub-samples formed on shareholder proposals (corporate governance) to further explore the above substitution effects.
Findings
Based on a sample of 2,041 firm-year observations from 2001 to 2010, this paper finds that the “For” votes received from the shareholder proposals have a significant negative relationship with the practice of earnings management, even when corporate governance is controlled. The negative relationship between shareholder proposal and magnitude of earnings management is also found to be stronger when firms have weak corporate governance. The overall evidence suggests that the external control from “voting-with-hand” shareholders has a significant impact on earnings management. In addition, shareholder proposals can substitute the monitoring mechanism for corporate governance in constraining managers’ myopic behavior.
Originality/value
This paper contributes to the extant literature by using the percentage of “For” votes for shareholder proposals as a proxy for shareholder pressure and concerns. This study contributes to the earnings management literature by showing the disciplinary effect of outside shareholders on managers’ reporting behavior. Also, it contributes to the corporate governance research by presenting that shareholder proposals can substitute for the internal control of corporate governance in decreasing earnings management. This paper should be of interest to investors and standard setters.
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Taotao Deng, Ting Dan and Weishu Zhao
High-speed railway (HSR) substantially affects tourism development, but this impact remains somewhat controversial. This study aims to explore the HSR–tourism nexus from the…
Abstract
Purpose
High-speed railway (HSR) substantially affects tourism development, but this impact remains somewhat controversial. This study aims to explore the HSR–tourism nexus from the perspective of Chinese local governance. In the context of promotion tournament model in China, this study attempts to explain such controversy by including local leaders.
Design/methodology/approach
Based on a data set from 25 cities in China’s Yangtze River Delta region during 2005–2019, this study uses a panel data regression model to examine local leaders’ moderating role in the HSR–tourism nexus.
Findings
The tenure of local leaders has a significant moderating role in the impact of HSR implementation on tourism development. Furthermore, a shorter leaders’ tenure strengthens the boost to tourism development from HSR service.
Originality/value
This paper enriches theoretical framework of leaders’ tournament theory. In addition, this study provides a new perspective to understand the HSR–tourism nexus better. This study identifies the moderating role of local leaders in the HSR–tourism nexus and expands the mechanism research of HSR–tourism nexus, which helps to explain the controversy of the HSR–tourism nexus.
目的
高速铁路(HSR)对旅游业的发展有很大的影响, 但这种影响仍有一定的争议性。本研究从中国地方治理的角度探讨了高铁-旅游之间的关系。在中国晋升锦标赛模式的背景下, 本研究试图通过将地方领导纳入其中来解释这种争论。
研究方法
基于2005-2019年中国长江三角地区25个城市的数据集, 我们利用面板数据回归模型来研究地方官员在高铁-旅游关系中的调节作用。
研究结果
地方官员的任期在高铁开通对旅游业发展的影响中起着重要的调节作用。此外, 较短的官员任期会加强高铁连通对旅游业发展的促进作用。
原创性/价值
本文丰富了官员锦标赛理论的理论框架。此外, 我们的研究为更好地理解高铁与旅游的关系提供了一个新的视角。我们确定了地方领导人在高铁-旅游关系中的调节作用, 拓展了高铁-旅游关系的机制研究, 有助于解释高铁-旅游关系的争论。
Propósito
El tren de alta velocidad (TAV) afecta sustancialmente al desarrollo del turismo, pero este impacto sigue siendo algo controvertido. Este estudio explora el nexo entre el TAV y el turismo desde la perspectiva de la gobernanza local china. En el contexto del modelo de torneo de promoción en China, este estudio intenta explicar dicha controversia incluyendo a los líderes locales.
Diseño/metodología/enfoque
Basándonos en un conjunto de datos de 25 ciudades de la región china del delta del río Yangtze durante el periodo 2005-2019, utilizamos un modelo de regresión de datos de panel para examinar el papel moderador de los líderes locales en el nexo entre el TAV y el turismo.
Resultados
El mandato de los líderes locales tiene un papel moderador significativo en el impacto de la implementación del TAV en el desarrollo del turismo. Además, un mandato más corto de los líderes refuerza el impulso al desarrollo turístico del servicio de TAV.
Originalidad/Valor
Este trabajo enriquece el marco teórico de la teoría del torneo de líderes. Además, nuestro estudio proporciona una nueva perspectiva para entender mejor el nexo entre el TAV y el turismo. Identificamos el papel moderador de los líderes locales en el nexo TAV-Turismo y ampliamos la investigación del mecanismo de dicho nexo, lo que ayuda a explicar la controversia del nexo.
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Xianliang Zhang, Weibing Zhu, Xiande Wu, Ting Song, Yaen Xie and Han Zhao
The purpose of this paper is to propose a pre-defined performance robust control method for pre-assembly configuration establishment of in-space assembly missions, and collision…
Abstract
Purpose
The purpose of this paper is to propose a pre-defined performance robust control method for pre-assembly configuration establishment of in-space assembly missions, and collision avoidance is considered during the configuration establishment process.
Design/methodology/approach
First, six-degrees-of-freedom error kinematic and dynamic models of relative translational and rotational motion between transportation systems are developed. Second, the prescribed transient-state performance bounds of tracking errors are designed. In addition, based on the backstepping, combining the pre-defined performance control method with a robust control method, a pre-defined performance robust controller is designed.
Findings
By designing prescribed transient-state performance bounds of tracking errors to guarantee that there is no overshoot, collision-avoidance can be achieved. Combining the pre-defined performance control method with a robust control method, robustness to disturbance is guaranteed.
Originality/value
This paper proposed a pre-defined performance robust control method. Simulation results demonstrate that the proposed controller can achieve a pre-assembly configuration establishment with collision avoidance in the existence of external disturbances.
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Jung-Kuei Hsieh, Werner H. Kunz and Ai-Yun Wu
This study aims to investigate the factors that affect an audience's purchase decisions on a new type of social media, namely live video streaming platforms.
Abstract
Purpose
This study aims to investigate the factors that affect an audience's purchase decisions on a new type of social media, namely live video streaming platforms.
Design/methodology/approach
This study is based on data from an online survey providing 488 valid responses. These responses are used to test the research model by employing partial least squares (PLS) modeling.
Findings
Three antecedents (consumer competitive arousal, gift design aesthetics and broadcaster's image) influence the audience's purchase decisions (impulse buying and continuous buying intention). Chinese impression management (mianzi) acts as a moderator. Self-mianzi, mutual mianzi and other mianzi (i.e. three subtypes of mianzi) moderate the effects of consumer competitive arousal, gift design aesthetics and broadcaster's image on impulse buying.
Practical implications
The findings encourage practitioners developing marketing strategies for live video streaming platforms in the Chinese cultural context to consider peer influence, gift appearance, broadcaster's image and mianzi.
Originality/value
Drawing on the community gift-giving model and face-negotiation theory, this study provides an integrated research model to investigate a new type of social media (live video streaming). It offers insight into virtual gifting behaviors by confirming the effects of three antecedents on the audience's purchase decisions, with mianzi acting as a moderator.
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Mehdi Ebrahimi, David S-K. Ting and Rupp Carriveau
Sustainable development calls for a larger share of intermittent renewable energy. To mitigate this intermittency, Compressed Air Energy Storage (CAES) technology was introduced…
Abstract
Sustainable development calls for a larger share of intermittent renewable energy. To mitigate this intermittency, Compressed Air Energy Storage (CAES) technology was introduced. This technology can be made more sustainable by recovering the heat of the compression phase and reusing it during the discharge phase, resulting in an adiabatic CAES without the need for burning of fossil fuels. The key process parameters of CAES are temperature, pressure ratios, and the mass flow rates of air and thermal fluids. The variation in these parameters during the charge and discharge phases significantly influences the performance of CAES plants. In this chapter, the transient thermodynamic behavior of the system under various operating conditions is analyzed and the impact of heat recovery on the discharge phase energy efficiency, power generation, and CO2 emissions is studied. Simulations are carried out over the air pressure range from 2,500 to 7,000 kPa for a 65 MW system over a five-hour discharge duration. It is also assumed that the heat loss in the air storage and the hot thermal fluid tank is insignificant and standby duration does not impact the status of the system. This result shows that the system exergy and the generated power are more sensitive to pressure change at higher pressures. This work also reveals that every 10°C increase on the temperature of the stored air can lead to a 0.83% improvement in the energy efficiency. The result of the transient thermodynamic model is used to estimate the reduction in CO2 emissions in CAES systems. According to the obtained result, a 65 MW ACAES plant can reduce about 17,794 tons of CO2 emission per year compared to a traditional CAES system with the same capacity.
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Ting Liu, Yan-Long Cao, Qijian Zhao, Jiangxin Yang and Lujun Cui
The purpose of this paper is to carry out an assembly tolerance analysis by means of a combined Jacobian model and skin model shape. The former is based on small displacements…
Abstract
Purpose
The purpose of this paper is to carry out an assembly tolerance analysis by means of a combined Jacobian model and skin model shape. The former is based on small displacements modeling of points using 6 × 6 transformation matrices of open kinematic chains in robotics. The latter easily models toleranced features with all kinds of geometric deviations.
Design/methodology/approach
This paper presents the procedure of performing tolerance analysis by means of the Jacobian model and skin model shape for assemblies. The point cloud-based discrete representative is able to model the actual toleranced surfaces instead of the ideal or associated ones in an assembly, which brings the simulation tools closer to reality.
Findings
The proposed method has the advantage of skin model shape which is suitable for geometric tolerances management along the product life cycle and contact analysis of kinematic small variations, as well as, with the Jacobian, enabling transformation of locally expressed parts deviations to globally expressed functional requirements. The result of the case study shows the accuracy of the method.
Research limitations/implications
The proposed approach has not been developed fully; other functional features such as the pyramid are still ongoing challenges.
Practical implications
It is an effective method for supporting design, manufacturing and inspection by providing a quantitative analysis of the effects of multi-tolerances on the final functional key characteristics and for predicting the quality level.
Originality/value
The paper is original in taking advantages of both Jacobian model and skin model shape to consider all geometric tolerances in assembly.
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Jun Zhang, Meng Wang, Pu Liu, Xiaoyan Zhang, Ting Huo, Zhengcan Chen, Chunli Liu, Boyuan Zhang, Shengyuan Zhao and Zhenbin Chen
In this study, a novel glutathione (GSH) surface molecular imprinting polymer (SMIP) was successfully prepared by using macroporous adsorption resins (MAR) as substrate, which…
Abstract
Purpose
In this study, a novel glutathione (GSH) surface molecular imprinting polymer (SMIP) was successfully prepared by using macroporous adsorption resins (MAR) as substrate, which could separate and purify GSH efficiently.
Design/methodology/approach
SMIP was synthesized by chloromethylated modified MAR (LX1180-Cl) as the substrate, N, N’-methylenebisacrylamide (NMBA) as a crosslinker, GSH as a template, acrylamide (AM) and N-vinylpyrrolidone (NVP) as functional monomers. The morphology and structure of the polymer were characterized by scanning electron microscope and Fourier transforms infrared spectroscopy.
Findings
The maximum adsorption capacity toward GSH was 39.0 mg/g and the separation decree had relation to L-cysteine (L-cys) was 4.2. The optimal operation conditions were studied in detail and the got as follows: the molar ratios of NMBA, AM, GSH and NVP, were 7.0, 0.8 and 0.5. The optimal time and temperature were 14 h and 40°C, respectively. The Langmuir and pseudo-first-order model were fitting these adsorption characteristics well.
Practical implications
GSH has a diversity of medicinal and bioactive functions, so the purpose of this study representing a method in separate and purify technology of GSH, which provided a way for the development of medicine.
Originality/value
This contribution provided a novel way to separate GSH from L-cys. Under the optimal conditions, the maximum adsorption capacity toward GSH was 39.0 mg/g and the separation decree had relation to L-cys was 4.2.
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The objective of this study is to investigate how country risk, different political actions from the government and bureaucratic behavior influence the activities in industry…
Abstract
The objective of this study is to investigate how country risk, different political actions from the government and bureaucratic behavior influence the activities in industry supply chains (SCs) in emerging markets. The main objective of this study is to investigate the influence of these external stakeholders’ elements to the demand-side and supply-side drivers and barriers for improving competitiveness of Ready-Made Garment (RMG) industry in the way of analyzing supply chain. Considering the phenomenon of recent change in the RMG business environment and the competitiveness issues this study uses the principles of stakeholder and resource dependence theory and aims to find out some factors which influence to make an efficient supply chain for improving competitiveness. The RMG industry of Bangladesh is the case application of this study. Following a positivist paradigm, this study adopts a two phase sequential mixed-method research design consisting of qualitative and quantitative approaches. A tentative research model is developed first based on extensive literature review. Qualitative field study is then carried out to fine tune the initial research model. Findings from the qualitative method are also used to develop measures and instruments for the next phase of quantitative method. A survey is carried out with sample of top and middle level executives of different garment companies of Dhaka city in Bangladesh and the collected quantitative data are analyzed by partial least square-based structural equation modeling. The findings support eight hypotheses. From the analysis the external stakeholders’ elements like bureaucratic behavior and country risk have significant influence to the barriers. From the internal stakeholders’ point of view the manufacturers’ and buyers’ drivers have significant influence on the competitiveness. Therefore, stakeholders need to take proper action to reduce the barriers and increase the drivers, as the drivers have positive influence to improve competitiveness.
This study has both theoretical and practical contributions. This study represents an important contribution to the theory by integrating two theoretical perceptions to identify factors of the RMG industry’s SC that affect the competitiveness of the RMG industry. This research study contributes to the understanding of both external and internal stakeholders of national and international perspectives in the RMG (textile and clothing) business. It combines the insights of stakeholder and resource dependence theories along with the concept of the SC in improving effectiveness. In a practical sense, this study certainly contributes to the Bangladeshi RMG industry. In accordance with the desire of the RMG manufacturers, the research has shown that some influential constructs of the RMG industry’s SC affect the competitiveness of the RMG industry. The outcome of the study is useful for various stakeholders of the Bangladeshi RMG industry sector ranging from the government to various private organizations. The applications of this study are extendable through further adaptation in other industries and various geographic contexts.
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Xiaohuan Liu, Degan Zhang, Ting Zhang, Jie Zhang and Jiaxu Wang
To solve the path planning problem of the intelligent driving vehicular, this paper designs a hybrid path planning algorithm based on optimized reinforcement learning (RL) and…
Abstract
Purpose
To solve the path planning problem of the intelligent driving vehicular, this paper designs a hybrid path planning algorithm based on optimized reinforcement learning (RL) and improved particle swarm optimization (PSO).
Design/methodology/approach
First, the authors optimized the hyper-parameters of RL to make it converge quickly and learn more efficiently. Then the authors designed a pre-set operation for PSO to reduce the calculation of invalid particles. Finally, the authors proposed a correction variable that can be obtained from the cumulative reward of RL; this revises the fitness of the individual optimal particle and global optimal position of PSO to achieve an efficient path planning result. The authors also designed a selection parameter system to help to select the optimal path.
Findings
Simulation analysis and experimental test results proved that the proposed algorithm has advantages in terms of practicability and efficiency. This research also foreshadows the research prospects of RL in path planning, which is also the authors’ next research direction.
Originality/value
The authors designed a pre-set operation to reduce the participation of invalid particles in the calculation in PSO. And then, the authors designed a method to optimize hyper-parameters to improve learning efficiency of RL. And then they used RL trained PSO to plan path. The authors also proposed an optimal path evaluation system. This research also foreshadows the research prospects of RL in path planning, which is also the authors’ next research direction.