Chengtao Wang, Wei Li, Yuqiao Wang, Xuefeng Yang, Shaoyi Xu, Kunpeng Li and Yunyun Zhao
The purpose of this paper is to predict quantitative level of stray current leaking to the buried metallic structure by establishing convolution neural network (CNN) model.
Abstract
Purpose
The purpose of this paper is to predict quantitative level of stray current leaking to the buried metallic structure by establishing convolution neural network (CNN) model.
Design/methodology/approach
First, corrosion experimental system of buried metallic structure is established. The research object of this paper is the polarization potential within 110 min, CNN model is used to predict the quantitative level of stray current leakage using the data from corrosion experimental system further. Finally, results are compared with the method using BP neural network.
Findings
Results show that the CNN model has better predictive effect and shorter prediction time than the BP model, the accuracy of which is 82.5507 per cent, and the prediction time is shortened by more than 10 times.
Originality/value
The established model can be used to forecast the level of stray current leakage in the subway system effectively, which provides a new theoretical basis for evaluating the stray current corrosion hazard of buried metallic structure.
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Keywords
Zeng Huawei, Wang Chengtao, Qiao Jie, Zhang Bingjing, Zhao Bing and Dai Chuangyun
The Monascus pigment has been widely applied in the food processing industry as a functional additive. Lovastatin and polysaccharides are two important bio-active materials found…
Abstract
Purpose
The Monascus pigment has been widely applied in the food processing industry as a functional additive. Lovastatin and polysaccharides are two important bio-active materials found in Monascus. Citrinin is considered as mycotoxin. Thus, it is important to produce high yields of intracellular Monascus pigments with high yields of lovastatin and polysaccharides, while maintaining low citrinin yields under liquid fermentation.
Design/methodology/approach
The intracellular yields of pigments, lovastatin, polysaccharides and citrinin; biomass; and reducing the sugar content of Monascus purpureus HBSD 08 were determined every day during a 10-day culturing period using lactose, maltose, sucrose, glucose, glycerine and xylose as the sole carbon sources. Additionally, the pigment composition was analysed by a thin layer chromatography (TLC) and the in vitro antitumor activities of the pigments were determined.
Findings
The maximal yield of pigments (55.44 U/mL after six days of culture) and lovastatin content (1,475.30 µg/L after five days of culture) were obtained in the presence of glucose and maltose as the sole carbon sources, respectively. The suitable carbon sources for high intracellular polysaccharides yields were sucrose, maltose and xylose. Glucose should not be chosen as the sole carbon source because of its high food safety risk. In vitro antitumor activities of pigments in the presence of different carbon sources were in the order of xylose > glucose = maltose > glycerine > sucrose = lactose. The pigment compositions in the presence of different carbon sources were the same from the TLC analysis. Thus, maltose displayed high intracellular yields of pigments, lovastatin and polysaccharides; high food safety against citrinin, and high in vitro antitumor activity during the ten days culturing period.
Originality/value
This study shows us the benefits of using maltose as a substrate in the production of intracellular Monascus pigments while ensuring economic and food safety.
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Keywords
Xiang Li, Chengtao Wang, Wenguang Zhang and Yuanchao Li
The purpose of this paper is to verify the feasibility and evaluate the compressive properties of Ti6Al4V implants with controlled porosity via electron beam melting process. This…
Abstract
Purpose
The purpose of this paper is to verify the feasibility and evaluate the compressive properties of Ti6Al4V implants with controlled porosity via electron beam melting process. This process might be a promising method to fabricate orthopedic implants with suitable pore architecture and matched mechanical properties.
Design/methodology/approach
Ti6Al4V implants with controlled porosity are produced using an electron beam melting machine. A scanning electron microscope is utilized to examine the macro‐pore structures of the Ti6Al4V implants. The compressive test is performed to investigate the mechanical properties of the porous implants.
Findings
The fabricated samples show a fully interconnected open‐pore network. The compressive yield strength of the Ti6Al4V implants with the porosity of around 51 percent is higher than that of human cortical bone. The Young's modulus of the implants is similar to that of cortical bone.
Research limitations/implications
The surface of samples produced by electron beam melting process is covered with loosely spherical metal particles. Polishing and ultrasonic cleaning have to be used to remove the loose remnants.
Originality/value
This paper presents the potential application in the fabrication of orthopedic or dental implants using electron beam melting process.
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Keywords
Xiuying Wang, Yu Chen, Kai Ding and Chengtao Yu
This study aims to obtain a design scheme of the surface texture on mechanical seal with lower friction and leakage by comparing two common texture types: dimples and grooves.
Abstract
Purpose
This study aims to obtain a design scheme of the surface texture on mechanical seal with lower friction and leakage by comparing two common texture types: dimples and grooves.
Design/methodology/approach
An optimal free-form shape and an optimal circular shape were chosen by multi-objective optimization, and two types of grooves with different directions were chosen by a series of experiments. Then, the optimal free-form dimple, the optimal circular dimple, the groove perpendicular to the direction of movement (hereafter called groove-1) and the groove angled at 60° to the direction of movement (hereafter called groove-2) were compared by experiments under different loads.
Findings
The optimal free-form dimple shows a better performance in terms of a lower coefficient of friction (COF) and a lower leakage than the other shapes, especially for the high speed and low load conditions. The reduction rate of COF is up to 37.5%, and the leakage rate is reduced by about 12.5%. The dimples have a lower leakage than the grooves. The groove angled at 60° to the direction of movement is easier to pump the oil into the interface of the sealing face, leading to a lower friction but a higher leakage.
Originality/value
This study provides a feasible surface texture design scheme for improving the combination performance of mechanical seals.
Details
Keywords
Ruiyang Ma, Chao Mao, Jiayin Yuan, Chengtao Jiang and Peiliang Lou
With the development of a new generation of digital technologies, digital transformation (DT) has become an inevitable trend for enterprises to achieve development in various…
Abstract
Purpose
With the development of a new generation of digital technologies, digital transformation (DT) has become an inevitable trend for enterprises to achieve development in various industries. Nevertheless, the contradiction between the “fragmented” use of digital technologies and the “systematic” transformation of the industry leads to the underperformance of DT in the construction industry. Whilst previous studies have examined why DT is needed and how separate digital technologies can be used in construction projects, they failed to specify effective tools that can help enterprises identify key resources that facilitate DT from the organisational perspective.
Design/methodology/approach
This study established an objective assessment framework for evaluating the digital transformation capability (DTC) of construction enterprises in identifying limitations in their transformation efforts. This study also established a management entropy quantitative model and a comprehensive capability evaluation model of DT to analyse the DT performance of construction enterprises from the internal and external perspectives. Data were collected from 95 listed enterprises in China’s construction industry in 2020 as a case study.
Findings
This study concluded that enterprise profitability provides a strong endogenous driving force for DT. Research and development capabilities and DT proficiency of enterprises are the most critical factors in facilitating DT. In addition, China’s construction enterprises' DT was characterised by uneven development and low orderliness. The lack of a unified digital integration platform is key to cracking the dilemma.
Originality/value
This paper systematically identified key DTC in construction enterprises and proposed an objective framework for measuring DTC to enhance the DT performance of these enterprises.
Details
Keywords
Chengtao Cai, Bing Fan, Xiangyu Weng, Qidan Zhu and Li Su
Because of their large field of view, omnistereo vision systems have been widely used as primary vision sensors in autonomous mobile robot tasks. The purpose of this article is to…
Abstract
Purpose
Because of their large field of view, omnistereo vision systems have been widely used as primary vision sensors in autonomous mobile robot tasks. The purpose of this article is to achieve real-time and accurate tracking by the omnidirectional vision robot system.
Design/methodology/approach
The authors provide in this study the key techniques required to obtain an accurate omnistereo target tracking and location robot system, including stereo rectification and target tracking in complex environment. A simple rectification model is proposed, and a local image processing method is used to reduce the computation time in the localization process. A target tracking method is improved to make it suitable for omnidirectional vision system. Using the proposed methods and some existing methods, an omnistereo target tracking and location system is established.
Findings
The experiments are conducted with all the necessary stages involved in obtaining a high-performance omnistereo vision system. The proposed correction algorithm can process the image in real time. The experimental results of the improved tracking algorithm are better than the original algorithm. The statistical analysis of the experimental results demonstrates the effectiveness of the system.
Originality/value
A simple rectification model is proposed, and a local image processing method is used to reduce the computation time in the localization process. A target tracking method is improved to make it suitable for omnidirectional vision system. Using the proposed methods and some existing methods, an omnistereo target tracking and location system is established.
Details
Keywords
Abstract
Purpose
The purpose of this study is to investigate the influence of groove shape on the hydrodynamic characteristics of a journal bearing.
Design/methodology/approach
The computational fluid dynamics model also takes into account the cavitation phenomena and thermal effect, which can illustrate the lubrication performance of a journal bearing.
Findings
The hydrodynamic simulations of the journal bearing with the different groove shapes are conducted under different operation conditions.
Originality/value
Based on the numerical analysis, the suggestions are presented for groove shape selection and can be used to the design of a journal bearing under the extreme operation condition.
Details
Keywords
Dechang Zheng, Shuang Tao, Chengtao Jiang and Yinglun Tang
This study explores whether religion plays an important role in corporate poverty alleviation. Religious atmosphere affects managers' attitude towards corporate social…
Abstract
Purpose
This study explores whether religion plays an important role in corporate poverty alleviation. Religious atmosphere affects managers' attitude towards corporate social responsibility (CSR) and then influences corporate poverty alleviation. This study first examines the impact of religious atmosphere on corporate poverty alleviation and then investigates whether formal institutions, such as law enforcement environments and ownership, influence the relationship between religious atmosphere and corporate poverty alleviation behavior.
Design/methodology/approach
In 2016, the Chinese government initiated a nationwide campaign aiming to eliminate poverty in China by 2020. The authors conduct empirical tests with data on Chinese listed firms from 2016 to 2020. The religious atmosphere is measured by the number of Buddhist monasteries and Taoist temples within a certain radius around Chinese listed firms' registered addresses. The authors adopt the ordinary least squares (OLS) method for regression and take the two-stage least squares (2SLS) method to address the endogeneity issue.
Findings
The results show a positive relationship between religious atmosphere and corporate poverty alleviation donations. Law enforcement attenuates the positive association between the religious atmosphere and corporate poverty alleviation donations. Religion and corporate poverty alleviation donations have a more positive association for non-state-owned enterprises (non-SOEs) than for state-owned enterprises (SOEs).
Research limitations/implications
The authors' findings have important implications. First, this study inspires incorporating the ethical value of traditional culture, such as religion, into CSR. Second, the findings imply that informal institutions have a greater impact on corporate decision-making when formal institutions are weak, suggesting that informal institutions should be emphasized when promoting CSR in countries where formal institutions are relatively weak. The study investigates only religious influence on corporate poverty alleviation based on Buddhism and Taoism, but the authors do not examine the impacts of other religions. Future research may examine the relationships between other religions and corporate poverty alleviation in China.
Originality/value
This study illustrates the positive role played by religion in promoting CSR by relating religious atmosphere to corporate poverty alleviation. It fills the research gap between religion and CSR and also contributes to the literature on determinants of corporate poverty alleviation.
Details
Keywords
Huiyuan Zhao, Yuxing Mao and Tao Cheng
Application environments of wireless sensor networks (WSNs) include heterogeneous nodes with different packet sizes, transmission abilities and tolerable delay times. This study…
Abstract
Purpose
Application environments of wireless sensor networks (WSNs) include heterogeneous nodes with different packet sizes, transmission abilities and tolerable delay times. This study aims to design a reasonable network topology and transmission timing for these heterogeneous nodes to improve the quality of service (QoS) of networks.
Design/methodology/approach
In this paper, the authors treat node urgency and data packets as the basis of network clustering and to extend the network lifetime. The flow, energy consumption and residual energy of a node are included in the cluster head election. We also propose a delay evaluation function.
Findings
All the nodes in the network are guaranteed to transmit to the sink nodes efficiently by planning the transmission order in each cluster.
Originality/value
The simulation results show that the proposed method can balance node urgency and data packets path planning, which not only extends the lifetime of the network but also decreases network delay and improves the overall efficiency.
Details
Keywords
Xinfa Shi, Ce Cui, Shizhong He, Xiaopeng Xie, Yuhang Sun and Chudong Qin
The purpose of this paper is to identify smaller wear particles and improve the calculation speed, identify more abrasive particles and promote industrial applications.
Abstract
Purpose
The purpose of this paper is to identify smaller wear particles and improve the calculation speed, identify more abrasive particles and promote industrial applications.
Design/methodology/approach
This paper studies a new intelligent recognition method for equipment wear debris based on the YOLO V5S model released in June 2020. Nearly 800 ferrography pictures, 23 types of wear debris, about 5,000 wear debris were used to train and test the model. The new lightweight approach of wear debris recognition can be implemented in rapidly and automatically and also provide for the recognition of wear debris in the field of online wear monitoring.
Findings
An intelligent recognition method of wear debris in ferrography image based on the YOLO V5S model was designed. After the training, the GIoU values of the model converged steadily at about 0.02. The overall precision rate and recall rate reached 0.4 and 0.5, respectively. The overall MAP value of each type of wear debris was 40.5, which was close to the official recognition level of YOLO V5S in the MS COCO competition. The practicality of the model was approved. The intelligent recognition method of wear debris based on the YOLO V5S model can effectively reduce the sensitivity of wear debris size. It also has a good recognition effect on wear debris in different sizes and different scales. Compared with YOLOV. YOLOV, Mask R-CNN and other algorithms%2C, the intelligent recognition method based on the YOLO V5S model, have shown their own advantages in terms of the recognition effect of wear debris%2C the operation speed and the size of weight files. It also provides a new function for implementing accurate recognition of wear debris images collected by online and independent ferrography analysis devices.
Originality/value
To the best of the authors’ knowledge, the intelligent identification of wear debris based on the YOLO V5S network is proposed for the first time, and a large number of wear debris images are verified and applied.