Yue Wang, Han Zhao, Haiyue Yang and Xiangshuai Song
The visible time window (VTW) calculation of satellites to ground targets is significant for Earth observation satellites' operation management and control. With the improvement…
Abstract
Purpose
The visible time window (VTW) calculation of satellites to ground targets is significant for Earth observation satellites' operation management and control. With the improvement of satellite maneuvering capability and the complexity of on-orbit observation tasks, the traditional VTW calculation methods can no longer meet the demands of satellite operation management and control due to a large amount of calculation and low efficiency. The purpose of this study is to propose a fast VTW calculation method based on map segmentation named map segmentation method (MSM), to improve the calculation efficiency, and further solve this problem.
Design/methodology/approach
The main feature of the MSM method is to segment the map and subsatellite trajectories and traverse the subsatellite points within a specific range around the target, significantly reducing the search space and the amount of computation and improving computational efficiency.
Findings
Numerical simulations for two satellite orbits are implemented to verify the feasibility of the proposed VTW calculation method, and the traditional traversal method (TM) is also performed for comparative analysis. The results show that the proposed method can obtain the same VTW, using less calculation time than the TM. The computational efficiency is significantly improved, especially for many tasks. The calculation time of observing 500 targets is saved by more than 70%, indicating a broad application prospect.
Originality/value
This paper proposes an original VTW calculation method based on map segmentation to improve the calculation efficiency. The simulation scenarios are designed to verify the accuracy and effectiveness of the proposed method, and the observation targets are randomly distributed on the map. For comparative analysis, the TM is also performed under the same simulation conditions.
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This study aims to conduct a dynamic analysis of consumer attitudes towards domestic brands under the influence of multiple-period opinion events, providing methodological…
Abstract
Purpose
This study aims to conduct a dynamic analysis of consumer attitudes towards domestic brands under the influence of multiple-period opinion events, providing methodological guidance for the overall development of fast-fashion clothing brands.
Design/methodology/approach
This study takes the Xinjiang cotton event and ERKE donation event in 2021 as the samples and Weibo comments on the hot topic of the fact that ANTA’s total turnover exceeded NIKE’s on the 2021 Double 11 as the first and explores the process and influencing factors of consumer domestic brand attitude change through latent Dirichlet allocation (LDA) model.
Findings
Under the influence of multiple public opinion events, consumers’ attitudes towards domestic brands experienced changes from brand awareness and brand identification to brand loyalty. First of all, patriotism and the awareness of Chinese goods lead to consumers’ brand awareness. The social responsibility and perceived quality of the later stage will stimulate consumers’ brand identification. Finally, the matching of national pride and perceived products will promote consumers’ brand loyalty.
Originality/value
This study establishes a model of the evolution of consumer attitudes towards domestic brands, revealing for the first time from a dynamic perspective the factors influencing these attitudes. This study offers a novel perspective on the processes and structures of the relationship between consumers and domestic brands.
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Han Zhao, Qingmiao Ding, Yaozhi Li, Yanyu Cui and Junjie Luo
This paper aims to study the influence of microparticles on the surface cavitation behavior of 2Cr3WMoV steel; microparticle suspensions of different concentration, particle size…
Abstract
Purpose
This paper aims to study the influence of microparticles on the surface cavitation behavior of 2Cr3WMoV steel; microparticle suspensions of different concentration, particle size, material and shape were prepared based on ultrasonic vibration cavitation experimental device.
Design/methodology/approach
2Cr3WMoV steel was taken as the research object for ultrasonic cavitation experiment. The morphology, quantity and distribution of cavitation pits were observed and analyzed by metallographic microscope and scanning electron microscope.
Findings
The study findings showed that the surface cavitation process produced pinhole cavitation pits on the surface of 2Cr3WMoV steel. High temperature in the process led to oxidation and carbon precipitation on the material surface, resulting in the “rainbow ring” cavitation morphology. Both the concentration and size of microparticles affected the number of pits on the material surface. When the concentration of microparticles was 1 g/L, the number of pits reached the maximum, and when the size of microparticles was 20 µm, the number of pits reached the minimum. The microparticles of Fe3O4, Al2O3, SiC and SiO2 all increased the number of pits on the surface of 2Cr3WMoV steel. In addition, the distribution of pits of spherical microparticles was more concentrated than that of irregularly shaped microparticles in turbidity.
Originality/value
Most of the current studies have not systematically focused on the effect of each factor of microparticles on the cavitation behavior when they act separately, and the results of the studies are more scattered and varied. At the same time, it has not been found to carry out the study of microparticle cavitation with 2Cr3WMoV steel as the research material, and there is a lack of relevant cavitation morphology and experimental data.
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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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Abstract
The interbank market in China experienced remarkable squeezes in liquidity in 2013. In particular, the overnight Shanghai Interbank Offered Rate reached a historical high in June. Banks were unprepared, facing the occurrence of various liquidity demands simultaneously. Effects of the liquidity squeeze spread across markets, and concerns were expressed about the health of the banking sector in the world’s second largest economy. Yet the central bank of China maintained an unswerving view that the tightness of liquidity was only structural, and could be overcome by the commercial banks themselves. While it may be too early to judge whether the central bank was correct, or whether there is systematic liquidity risk in the banking sector, markets received a clear signal from the People’s Bank of China. The central bank stopped acting as a ‘perpetual put option’ for commercial banks and refused to take responsibility to satisfy liquidity needs in the interbank market. Its intention is clear; that is, to adjust monetary policy and support economic reform in China. The new Chinese government seems determined to steer a new course away from the previous growth episode. Its resolution has been published and actions have been taken. Among them, the central bank’s changes to monetary policy have received responses from the markets, and the People’s Bank of China is now in the vanguard of a battle to squeeze liquidity. It is difficult to predict what further actions the government will take. However, it should be aware that the driving force of economic reform in China comes from structural change and productivity improvement. Without follow-up policies, complication in the financial system could undermine the central bank’s effort and international capital flows may quickly substitute the opening position of the central bank in the interbank market. More wisdom is required if China is to win the battle for deleveraging and structural reform.
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Pingyang Zheng, Shaohua Han, Dingqi Xue, Ling Fu and Bifeng Jiang
Because of the advantages of high deposition efficiency and low manufacturing cost compared with other additive technologies, robotic wire arc additive manufacturing (WAAM…
Abstract
Purpose
Because of the advantages of high deposition efficiency and low manufacturing cost compared with other additive technologies, robotic wire arc additive manufacturing (WAAM) technology has been widely applied for fabricating medium- to large-scale metallic components. The additive manufacturing (AM) method is a relatively complex process, which involves the workpiece modeling, conversion of the model file, slicing, path planning and so on. Then the structure is formed by the accumulated weld bead. However, the poor forming accuracy of WAAM usually leads to severe dimensional deviation between the as-built and the predesigned structures. This paper aims to propose a visual sensing technology and deep learning–assisted WAAM method for fabricating metallic structure, to simplify the complex WAAM process and improve the forming accuracy.
Design/methodology/approach
Instead of slicing of the workpiece modeling and generating all the welding torch paths in advance of the fabricating process, this method is carried out by adding the feature point regression branch into the Yolov5 algorithm, to detect the feature point from the images of the as-built structure. The coordinates of the feature points of each deposition layer can be calculated automatically. Then the welding torch trajectory for the next deposition layer is generated based on the position of feature point.
Findings
The mean average precision score of modified YOLOv5 detector is 99.5%. Two types of overhanging structures have been fabricated by the proposed method. The center contour error between the actual and theoretical is 0.56 and 0.27 mm in width direction, and 0.43 and 0.23 mm in height direction, respectively.
Originality/value
The fabrication of circular overhanging structures without using the complicate slicing strategy, turning table or other extra support verified the possibility of the robotic WAAM system with deep learning technology.
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Chi Hung Leung and Yan Mu
The rates of emotional distress have risen in many countries during the COVID-19 pandemic. This study assessed the emotional distress of adolescents and young adults in Hong Kong…
Abstract
Purpose
The rates of emotional distress have risen in many countries during the COVID-19 pandemic. This study assessed the emotional distress of adolescents and young adults in Hong Kong and mainland China in the first year of the pandemic and tested whether spirituality was a protective factor against this emotional distress.
Design/methodology/approach
Cross-sectional data were collected in two samples of students aged 17–25 in Hong Kong (N = 503) and 13–20 in mainland China (N = 649). Participants completed the Spiritual Health and Life Orientation Measure (SHALOM) to evaluate their spiritual health (personal-communal, environmental and transcendental domains) and the short form of the Depression, Anxiety and Stress Scale-21 (DASS-21) to assess their emotional distress.
Findings
Based on the DASS-21 scores, there was a high rate of adolescents and young adults categorized as showing extremely severe symptoms of depression, anxiety and stress in both Hong Kong and mainland China. Structural equation modeling showed that in both the Hong Kong and mainland China samples the personal and communal and environmental domains of spiritual health were significantly and negatively correlated with all three forms of emotional distress. However, transcendental spiritual health was uncorrelated with psychological distress in Hong Kong and positively correlated with psychological distress in mainland China.
Research limitations/implications
The high rate of severe emotional distress in this sample of adolescents and young adults under COVID-19, and the fact that not all aspects of spiritual health protected again psychological distress are cause for concern, with implications for government, education systems and students.
Originality/value
Healthy spirituality can be found among youths who are upbeat, self-confident, optimistic and constructive and have also been shown to have a higher quality of life in the form of mental, physical and psychological health. The present study is the first study to examine the spiritual and mental health of high school and university students under the impact of COVID-19 in mainland China and in Hong Kong.
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Wang Zhizhong, Han Chao, Guosheng Huang, Han Bin and Han Bin
The deposition of particles onto a substrate during the cold spraying (CS) process relies on severe plastic deformation, so there are various micro-defects induced by insufficient…
Abstract
Purpose
The deposition of particles onto a substrate during the cold spraying (CS) process relies on severe plastic deformation, so there are various micro-defects induced by insufficient deformation and severe crushing. To solve the problems, many post-treat techniques have been used to improving the quality by eliminating the micro-defects. This paper aims to help scholars and engineers in this field a better and systematic understand of CS technology by summarizing the post-treatment technologies that have been investigated recently years.
Design/methodology/approach
This review summarizes the types of micro-defects and introduces the effect of micro-defects on the properties of CS coating/additive manufactured, illustrates the post-treatment technologies and its effect on the microstructure and performances, and finally outlooks the future development trends of post-treatments for CS.
Findings
There are significant discoveries in post-treatment technology to change the performance of cold spray deposits. There are also many limitations for post-treatment methods, including improved performance and limitations of use. Thus, there is still a strong requirement for further improvement. Hybrid post-treatment may be a more ideal method, as it can eliminate more defects than a single method. The proposed ultrasonic impact treatment could be an alternative method, as it can densify and flatten the CS deposits.
Originality/value
It is the first time to reveal the influence factors on the performances of CS deposits from the perspective of microdefects, and proposed corresponding well targeted post-treatment methods, which is more instructive for improving the performances of CS deposits.
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Yong Han and Hongdan Zhao
The purpose of this paper is to describe family‐friendly policies at Shanghai Shuozhi Management Consulting Co. Ltd.
Abstract
Purpose
The purpose of this paper is to describe family‐friendly policies at Shanghai Shuozhi Management Consulting Co. Ltd.
Design/methodology/approach
The paper examines the background to the policies, the form they take and some of the results they achieve.
Findings
The paper reports the role of stable monthly pay and perks; family‐supportive supervisors; family‐friendly colleagues; professional‐development programs; child‐related support programs; and physical health and psychological well being programs at Shanghai Shuozhi Management Consulting.
Practical implications
The view is advanced that organizations and employees in China who want to have a work‐family benefits workplace should adopt the strategies mentioned in this paper. The paper situates family‐friendly policies at Shanghai Shuozhi Management Consulting in the context of Chinese society as a whole.
Originality/value
The paper considers some of the similarities and differences between work‐life balance policies at Shanghai Shuozhi Management Consulting and those in the west.
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The purpose of this paper is to undertake research on the relationship of firm heterogeneity and innovation diffusion performance, and the role of absorptive capacity in this…
Abstract
Purpose
The purpose of this paper is to undertake research on the relationship of firm heterogeneity and innovation diffusion performance, and the role of absorptive capacity in this relationship.
Design/methodology/approach
Based on the diffusion of innovation theory, enterprise heterogeneity directly affects the evaluation stage (considering whether to adopt it) and the experimental stage (observing whether it is suitable for one’s own situation) of the diffusion process. Therefore, the paper uses a structural equation model to construct the influencing factors model of enterprise heterogeneity on technology diffusion. Furthermore, questionnaires were distributed to 236 enterprises with different scales, nature and location to explore the impact of heterogeneity on technology diffusion with scientific, objective and comprehensive data.
Findings
Firm heterogeneity has a positive effect on absorptive capacity and absorptive capacity has a positive effect on technological innovation diffusion performance. Thus, absorptive capacity plays an intermediary role in the effect on enterprise heterogeneity and technological innovation diffusion performance. More interestingly, the authors get some results that are not entirely consistent with the theoretical assumptions.
Practical implications
Firm heterogeneity plays a central role in the process of innovation diffusion. Enterprises should build internal management platforms to enhance cooperation among employees, and establish links with other enterprises for opportunities for win-win cooperation. In addition, enterprises should control the frequency of internal activities, which will undermine the enthusiasm of enterprise members to participate in technology sharing.
Originality/value
This paper explores the interaction between technology potential, cooperation frequency and absorptive capacity from the perspective of systems theory. The findings enrich the theory of innovation diffusion, and explore the inherent reasons why enterprise heterogeneity affects innovation diffusion. Furthermore, the theory that intra-firm cooperation promotes innovation diffusion is not always correct.