Zhengtuo Wang, Yuetong Xu, Guanhua Xu, Jianzhong Fu, Jiongyan Yu and Tianyi Gu
In this work, the authors aim to provide a set of convenient methods for generating training data, and then develop a deep learning method based on point clouds to estimate the…
Abstract
Purpose
In this work, the authors aim to provide a set of convenient methods for generating training data, and then develop a deep learning method based on point clouds to estimate the pose of target for robot grasping.
Design/methodology/approach
This work presents a deep learning method PointSimGrasp on point clouds for robot grasping. In PointSimGrasp, a point cloud emulator is introduced to generate training data and a pose estimation algorithm, which, based on deep learning, is designed. After trained with the emulation data set, the pose estimation algorithm could estimate the pose of target.
Findings
In experiment part, an experimental platform is built, which contains a six-axis industrial robot, a binocular structured-light sensor and a base platform with adjustable inclination. A data set that contains three subsets is set up on the experimental platform. After trained with the emulation data set, the PointSimGrasp is tested on the experimental data set, and an average translation error of about 2–3 mm and an average rotation error of about 2–5 degrees are obtained.
Originality/value
The contributions are as follows: first, a deep learning method on point clouds is proposed to estimate 6D pose of target; second, a convenient training method for pose estimation algorithm is presented and a point cloud emulator is introduced to generate training data; finally, an experimental platform is built, and the PointSimGrasp is tested on the platform.
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Keywords
Hongyao Shen, Xiaoxiang Ye, Guanhua Xu, Linchu Zhang, Jun Qian and Jianzhong Fu
During the 3D printing process, the model needs to add a support structure to ensure structural stability. Excessive support structure reduces printing efficiency and results in…
Abstract
Purpose
During the 3D printing process, the model needs to add a support structure to ensure structural stability. Excessive support structure reduces printing efficiency and results in material cost. A flexible support platform for 3 D printing has been designed. It can form an external support structure to replace the original support structure. This paper aims to study the influence of a model’s build orientation on properties when the model is printed on the platform, aiming to provide users with suitable solutions.
Design/methodology/approach
A fitness function for estimating the support structure with a support length is constructed. The particle swarm optimization (PSO) algorithm is modified and applied to find the build orientation that minimizes the support structure. However, when the model is printed on the platform, the build orientation of the minimum support structure enhances the complexity of the working path, resulting in an increase of printing time, which needs to be avoided. This paper applies a multi-objective particle swarm optimization (MOPSO) algorithm to minimize the support structure while minimizing printing time. The Pareto solution is obtained by the algorithm.
Findings
It is found that the model that has the cantilever structure can reduce more support structure after optimization on the platform, when there is surface quality requirement. When there is no limit, the modified algorithm can minimize the support structure of each model. Considering support structure and printing time, the MOPSO algorithm can easily get optimization results to guide the practical work.
Originality/value
This paper optimizes the model’s build orientation on the flexible support platform by PSO, thereby reducing material cost and improving work efficiency.
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Xiaomiao Niu, Hongyao Shen, Guanhua Xu, Linchu Zhang, Jianzhong Fu and Xiaolei Deng
Mg-Al powder mixture was used to manufacture Mg-Al alloy by laser powder bed fusion (LPBF) process. This study aims to investigate the influence of initial Al content and…
Abstract
Purpose
Mg-Al powder mixture was used to manufacture Mg-Al alloy by laser powder bed fusion (LPBF) process. This study aims to investigate the influence of initial Al content and processing parameters on the formability, microstructure and consequent mechanical properties of the laser powder bed fused (LPBFed) component.
Design/methodology/approach
In this study, Al powder with different weight ratio ranged from 3 to 9 per cent was mixed with pure Mg powder, and the powder mixture was processed using different LPBF parameters. Microstructure and compressive properties of the LPBFed components were examined.
Findings
It was found that the presence of Al significantly modified the microstructure and improved the mechanical properties of the LPBFed components. Higher volume of ß-Al12Mg17 precipitates was produced at higher initial Al content and higher laser energy density. For this reason, the a-Mg was significantly refined and the compressive strength was improved. The highest yield compressive strength achieved was 279 MPa when using Mg-9 Wt. % Al mixture.
Originality/value
This work demonstrates that LPBF of Mg-Al powder mixture was a viable way to additively manufacture Mg-Al alloy. Both Al content and processing parameters can be modified to control the microstructure and mechanical properties of the LPBFed components.
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The purpose of this paper is to delineate the evolution of agricultural science and technology (S&T) in China in the last three decades as it has been one of the major factors…
Abstract
Purpose
The purpose of this paper is to delineate the evolution of agricultural science and technology (S&T) in China in the last three decades as it has been one of the major factors, besides others, in ensuring comfortable levels of global food security. In doing so, it focuses on policy and progress, which have provided the right ambience for Chinese agricultural science and technology to evolve into an effective instrument of development.
Design/methodology/approach
The study employs institutional approach to government, scientists and farmers, who have been contributing to the growth of Chinese agricultural technology in two distinct ways. While the government has been playing a critical role in evolving a comprehensive agricultural S&T policy, scientists and farmers have been contributing to the progress of agricultural growth through research and application of various agricultural technologies.
Findings
Agricultural S&T in China has increasingly been growing into a potent force in facilitating comfortable levels of food security but with serious implications on the environment. Of the three players who have been instrumental in this process, the Chinese Government and the scientists are well prepared for WTO and globalization vis‐à‐vis agricultural technology, but the farmers are not well positioned.
Originality/value
Agricultural S&T development in China is critically important not only for Chinese food security but also for the larger global food and human security, as the two are inextricably connected. While most studies focus on various dimensions of agricultural technology, this study focuses on government, scientists and involved farmers, whose role is central to this process, and who are forced to rethink and reposition themselves in the development and use of agricultural S&T in China.
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Guanhua Wang, Yaqin Wang, Xiaowei Ju and Xueqin Rui
This study examines the effect of political networking capability (PNC) and strategic capability on exploratory innovation/exploitative innovation through the mediation of…
Abstract
Purpose
This study examines the effect of political networking capability (PNC) and strategic capability on exploratory innovation/exploitative innovation through the mediation of absorptive capability (AC).
Design/methodology/approach
Using empirical survey data collected from 153 traditional manufacturing firms (TMFs) in China, the authors apply partial least squares structural equation modeling (PLS-SEM) combined with mediation analyses to test hypotheses.
Findings
PNC has a higher impact on exploratory innovation than exploitative innovation through AC. The authors thus provide novel empirical insights into independent variables of firms' ambidextrous innovation and their implementation mechanisms.
Research limitations/implications
The authors highlight a unique situation of China and contribute to the literature on PNC and AC. The findings demonstrate that AC plays an important role in configuring government-obtained external resources into new products, thus influencing ambidextrous innovation strategic decisions.
Practical implications
TMFs' executives should enhance PNC to obtain more resources to conduct exploratory and exploitative innovation. Government officials and policymakers should strengthen the supervision of TMFs' innovation activities and adopt effective measures to ensure that TMFs could conduct more exploratory innovation as governments expected.
Originality/value
This study provides new insights by bridging research gaps in the literature and advances the insights of how TMFs' PNC/strategic capability directly and indirectly fosters exploratory and exploitative innovation via the mediating role of AC in China.
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Jinliang Liu, Yanmin Jia, Guanhua Zhang and Jiawei Wang
The calculation of the crack width is necessary for the design of prestressed concrete (PC) members. The purpose of this paper is to develop a numerical model based on the…
Abstract
Purpose
The calculation of the crack width is necessary for the design of prestressed concrete (PC) members. The purpose of this paper is to develop a numerical model based on the bond-slip theory to calculate the crack width in PC beams.
Design/methodology/approach
Stress calculation method for common reinforcement after beam crack has occurred depends on the difference in the bonding performance between prestressed reinforcement and common reinforcement. A numerical calculation model for determining the crack width in PC beams is developed based on the bond-slip theory, and verified using experimental data. The calculation values obtained by the proposed numerical model and code formulas are compared, and the applicability of the numerical model is evaluated.
Findings
The theoretical analysis and experimental results verified that the crack width of PC members calculated based on the bond-slip theory in this study is reasonable. Furthermore, the stress calculation method for the common reinforcement is verified. Compared with the model calculation results obtained in this study, the results obtained from code formulas are more conservative.
Originality/value
The numerical calculation model for crack width proposed in this study can be used by engineers as a reference for calculating the crack width in PC beams to ensure the durability of the PC member.
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Jiawei Wang, Guanhua Zhang, Jinliang Liu and Yanmin Jia
During service period, the bridge structures will be affected by the environment and load, so the carrying capacity will decline. The purpose of this paper is to research on the…
Abstract
Purpose
During service period, the bridge structures will be affected by the environment and load, so the carrying capacity will decline. The purpose of this paper is to research on the bearing capacity of bridge structures with time.
Design/methodology/approach
Destructive test and non-linear finite element analysis are carried out by utilizing two pretensioning prestressed concrete hollow slabs in service for 20 years; using the structural test deflection value to simulate the stiffness degradation of the service bridge and the finite element calculation results verify the accuracy of the calculation.
Findings
The flexural rigidity of the main beam when the test beam is destructed is degraded to approximately 20 percent of that before the test, which agrees well with the result of finite element analysis and indicates that the method of deducing the flexural rigidity of the structure according to the measured deflection value can effectively simulate the rigidity degradation law of the bridge in service. The crack resistance property of the test beam degrades obviously and the ultimate bearing capacity of the bending resistance does not degrade obviously.
Originality/value
The research results truly reflect the destruction process, destructive form, bearing capacity and rigidity degradation law of the old beam of the concrete bridge in service for 20 years and can provide technical basis for optimization design of newly built bridges of the same type and maintenance and reinforcement design of existing old bridges.
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Guanhua Zhang, Jiawei Wang, Jinliang Liu, Yanmin Jia and Jigang Han
During service, cracks are caused in prestressed concrete beams owing to overload or other non-load factors. These cracks significantly affect the safety of bridge structures. The…
Abstract
Purpose
During service, cracks are caused in prestressed concrete beams owing to overload or other non-load factors. These cracks significantly affect the safety of bridge structures. The purpose of this paper is to carry out a non-linear iterative calculation for a section of a prestressed concrete beam and obtain the change in stiffness after the section cracks.
Design/methodology/approach
The existing stress of prestressed reinforcement was measured by performing a boring stress release test on two pieces of an in-service 16 m prestressed concrete hollow plate. Considering the non-linear effects of materials, the calculation model of the loss in the flexural stiffness of the prestressed concrete beam was established based on the existing prestress. The accuracy of the non-linear calculation method and the results obtained for the section were verified by conducting a bending destruction test on two pieces of the 16 m prestressed concrete hollow plate in the same batch and by utilising the measured strain and displacement data on the concrete at the top edge of the midspan section under all load levels.
Findings
The flexural stiffness of the section decreases rapidly at first and then gradually, and structural rigidity is sensitive to the initial cracking of the beam. The method for calculating the loss in the flexural stiffness of the section established with the existing stress of prestressed reinforcement as a parameter is accurate and feasible. It realizes the possibility of assessing the loss in the rigidity of a prestressed concrete structure by adopting the existing stress of prestressed reinforcement as a parameter.
Originality/value
A method for quickly determining the loss in the stiffness of structures using existing prestress is established. By employing this method, engineers can rapidly determine whether a bridge is dangerous or not without performing a loading test. Thus, this method not only ensures the safety of human life, but also reduces the cost of testing.
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Ye Yuan, Gang Liu, Rui Dang, Stephen Siu Yu Lau and Guanhua Qu
The purpose of this paper is to identify the design elements of environmental features that affect consumer experience in shopping malls and develop a comprehensive understanding…
Abstract
Purpose
The purpose of this paper is to identify the design elements of environmental features that affect consumer experience in shopping malls and develop a comprehensive understanding of the relationship between architectural design and consumer experience.
Design/methodology/approach
Through the systematic literature review, 13 design elements were obtained and then verified through interviews of 30 professional designers. The obtained elements were made into a questionnaire to collect data across China from 1,016 consumers of different groups. Data were analyzed using cluster analysis, principal component analysis and difference analysis.
Findings
The results show that design elements that influence consumer experience in shopping malls are a four-dimensional construct: visual atmosphere, physical environment comfort, space structure and business planning, among which space structure and business planning play a larger role in the consumer experience. In addition, the perception differences of consumers for those elements are significant due to the individual differences.
Originality/value
This paper comprehensively investigates the architectural design elements affecting consumer experience in the Chinese mall context. Moreover, it provides unique insights about the relationship between architectural design and consumer experience by exploring the categories, weights and perception differences of those elements.
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Xiaowei Ju, Guanhua Wang and Yu Fu
From the perspective of social networks and knowledge networks, this study aims to empirically examine an updated four-dimension networking capability (NC) construct and test the…
Abstract
Purpose
From the perspective of social networks and knowledge networks, this study aims to empirically examine an updated four-dimension networking capability (NC) construct and test the relationships between it and innovation strategies through knowledge application activities in the context of Chinese manufacturing firms.
Design/methodology/approach
Data analysis is conducted on a quantitative survey of 219 manufacturing firms in China with a mixed method of partial least squares structural equation modeling and fuzzy-set qualitative comparative analysis.
Findings
The results indicate that knowledge assimilation application (KAA) and knowledge transformation application (KTA) fully mediate the relationships between NC and ambidextrous innovation strategies. KAA has a stronger association with exploitative innovation (EL) than with exploratory innovation (ER), and KTA has a stronger association with ER than with EL.
Research limitations/implications
The authors develop the conceptualization of NC and examine its role in knowledge application activities within a firm. Further, the authors adopt an alternative perspective to highlight the importance of KAA and KTA in mediating the relationships between NC and exploratory and exploitative innovation strategies.
Practical implications
The findings indicate that firms should build NC based on their knowledge requirements and knowledge network structure. Additionally, managers should possess in-depth insights regarding an effective knowledge application toward different types of external knowledge from partners. More specific, firms are more likely to conduct KAA for a high degree of knowledge relatedness, while for a low degree of knowledge relatedness, firms are more likely to conduct KTA.
Originality/value
The authors provide a novel alternative insight into knowledge application activities. From the perspective of knowledge networks, the authors argue that there are two distinct and parallel activities (i.e. KAA and KTA). The authors empirically examined the mediating roles of KAA and KTA in the NC–ambidextrous innovation strategies relationships as well as enriched the literature on their relationships.