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1 – 10 of over 1000Guoquan Zhang, Yaohui Wang, Jian He and Yi Xiong
Composite cellular structures have wide application in advanced engineering fields due to their high specific stiffness and strength. As an emerging technology, continuous…
Abstract
Purpose
Composite cellular structures have wide application in advanced engineering fields due to their high specific stiffness and strength. As an emerging technology, continuous fiber-reinforced polymer additive manufacturing provides a cost-effective solution for fabricating composite cellular structures with complex designs. However, the corresponding path planning methods are case-specific and have not considered any manufacturing constraints. This study aims to develop a generally applicable path planning method to fill the above research gap.
Design/methodology/approach
This study proposes a path planning method based on the graph theory, yielding an infill toolpath with a minimum fiber cutting frequency, printing time and total turning angle. More specifically, the cellular structure design is converted to a graph first. Then, the graph is modified to search an Eulerian path by adding an optimal set of extra edges determined through the integer linear programming method. Finally, the toolpath with minimum total turning angle is obtained with a constrained Euler path search algorithm.
Findings
The effectiveness of the proposed method is validated through the fabrication of both periodic and nonperiodic composite cellular structures, i.e. triangular unit cell-based, Voronoi diagram-based and topology optimized structures. The proposed method provides the basis for manufacturing planar thin-walled cellular structures of continuous fiber-reinforced polymer (CFRP). Moreover, the proposed method shows a notable improvement compared with the existing method. The fiber cutting frequency, printing time and total turning angle have been reduced up to 88.7%, 52.6% and 65.5%, respectively.
Originality/value
A generally applicable path planning method is developed to generate continuous toolpaths for fabricating cellular structures in CFRP-additive manufacturing, which is an emerging technology. More importantly, manufacturing constraints such as fiber cutting frequency, printing time and total turning angle of fibers are considered within the process planning for the first time.
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Zhenhua Luo, Yixi Chen, Kang Cen, Haize Pan, Mengfan Zhong and Jian He
In recent years, to solve the contradiction between energy supply and demand, the Chinese Government has vigorously promoted shale gas development. With the rapid development of…
Abstract
Purpose
In recent years, to solve the contradiction between energy supply and demand, the Chinese Government has vigorously promoted shale gas development. With the rapid development of the shale gas industry, the environmental impact problems have become increasingly serious. Therefore, it is of great significance to carry out a comprehensive environmental impact assessment of shale gas development. This study aims to provide a theoretical basis for enterprises to make development decisions on shale gas projects by constructing a model of comprehensive environmental impact assessment for shale gas development.
Design/methodology/approach
In this paper, the comprehensive environmental impact factors of shale gas development are analyzed from the two aspects of the natural environment and macro environment, and the index system of comprehensive environmental impact assessment for shale gas development including 7 secondary indicators and 24 tertiary indicators is constructed. Owing to the fact that qualitative indicators are difficult to quantify in the evaluation process, the method of intuitionistic fuzzy analytic hierarchy process (IFAHP) is adopted for evaluation. This method (IFAHP) can delicately describe the hesitancy degree of the decision-makers in the process of assigning a weight to the indicators, and make the weight assignment of each index more accurate. Furthermore, this method overcomes the shortcomings of the conventional methods, such as the complexity of calculation and the large amount of calculation.
Findings
The evaluation model is applied to a shale gas platform drilling project in Southwest China. Based on the ratings from 13 experts, the comprehensive environmental impact assessment grade of this project is good, indicating that the shale gas development project is feasible. The result is basically in line with the actual situation.
Originality/value
Based on the consideration of the natural environmental impacts of shale gas development, this paper also has considered the macro environmental impact of shale gas development, and has established the index system of comprehensive environmental impact assessment for shale gas development from the two aspects of the natural environment and macro environment. To overcome such difficulties as incomplete evaluation by decision-makers, cumbersome calculation process and a large amount of calculation, this paper has adopted the method of IFAHP to evaluate and has established a comprehensive environmental impact assessment model for shale gas development based on IFAHP.
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Kim-Shyan Fam, David S. Waller, Ernest Cyril de Run and Jian He
The purpose of this paper is to determine what can cause dislike of an advertisement's message in Asia. Television commercials were looked at specifically to provide an insight…
Abstract
Purpose
The purpose of this paper is to determine what can cause dislike of an advertisement's message in Asia. Television commercials were looked at specifically to provide an insight into the construct of advertising dislikeability and how it affects purchase intention and purchase frequency.
Design/methodology/approach
The study utilizes the attention/salience hypothesis. A total of 931 people were questioned in five Asian cities (Hong Kong, Shanghai, Jakarta, Bangkok and Mumbai) using telephone interviews.
Findings
The results revealed 931 dislike attributes that were reduced to seven: style, meaningless, character, exaggeration, irresponsive, violent and hard-sell. There also appears to be a close relationship between the disliking of advertisements and purchase intention and purchase frequency.
Practical implications
Findings indicate a strong relationship of the dislikeability variables with culture and religion in the five Asian cities and this must be taken seriously by advertisers. International advertisers need to pay attention to the local values and tradition and use the advertising communication message appropriately.
Social implications
Advertisers must be acutely aware of the social norms in designing their advertisements and the findings here can be a guide for public and/or industry policy towards advertising.
Originality/value
The paper has produced a new construct of advertising dislikeability and details how it affects purchase intention and purchase frequency. This construct can be further tested in other nations and situations, in order to develop an understanding of dislike towards advertising.
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Wei Xie and Maximilian von Zedtwitz
Through examining the development of the video compact disc player industry in China, this article aims to explore the main characteristics of world‐first innovation and identify…
Abstract
Purpose
Through examining the development of the video compact disc player industry in China, this article aims to explore the main characteristics of world‐first innovation and identify four success factors for innovation followers to launch world‐first products in catching‐up countries.
Design/methodology/approach
This article takes the form of a case study
Findings
The main characteristics of world‐first innovation in catching‐up countries include: from the demand side, innovation is mainly pulled by the local market, rather than technology‐push; from the supply side, innovation cannot isolate itself from the rest of the world – suppliers of key technologies in advanced countries play an important role; inter‐firm alliances are an increasingly important way to generate world‐first innovation; and downstream integration capabilities are required for followers to mix pieces of technologies together at competitive pricing. The success of followers from catching‐up countries to launch world‐first products hinges on the four critical factors: strengths of complementary assets; figuring out ways to meet local market demand without relying on large R&D spending; emphasizing untapped innovation opportunities by multinationals; and positioning themselves on the proper points of the globally coordinated network for innovation.
Originality/value
This article identifies the main characteristics of world‐first innovation and points out four success factors for innovation followers to launch world‐first products, which could be significant to managers in catching‐up countries. Findings of this paper are more relevant to large catching‐up countries such as India, Brazil, Mexico and Indonesia where a large domestic market could serve as important launch markets for the world‐first innovation.
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Hu Weibing, Chen Xing and He Jian
Based on the character of R‐C frame, the calculation formula of VED is derived from the sub‐structure plan of lateral resistant force, the definition of equivalent stiffness…
Abstract
Based on the character of R‐C frame, the calculation formula of VED is derived from the sub‐structure plan of lateral resistant force, the definition of equivalent stiffness matrix and equivalent additional viscoelastic force vector of VED is given and the seismic dynamic equation of R‐C frame controlled by VED is set up, the viscoelastic additional force vector of VED should be considered as outside load of structure and be calculated through the pseudo‐loading method, the programs of calculating the dynamic characteristic, calculating the elastic seismic response and calculating the elastic‐plastic seismic response of R‐C frame controlled by VED are compiled. Through the calculation of a inclined crossed R‐C frame, the results show that VED is effective in controlling the seismic response of frame and the pseudo‐loading method is reliable in the calculation.
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Jian‐Xin Shen, He Hao, Meng‐Jia Jin and Wei‐Zhong Fei
The purpose is to present a sensorless control method by which high‐resolution rotor position information is estimated and used for phase‐advancing operation of a high‐speed…
Abstract
Purpose
The purpose is to present a sensorless control method by which high‐resolution rotor position information is estimated and used for phase‐advancing operation of a high‐speed permanent magnet (PM) brushless DC (BLDC) motor.
Design/methodology/approach
The proposed sensorless control approach uses hardware to observe the flux vector which is excited by rotor magnets. It can provide the rotor position which is the same as the phase angle of the observed flux vector.
Findings
High‐resolution rotor position signal of the BLDC motor for dynamic phase‐advancing control cannot be directly obtained from the conventional Hall‐effect sensors, or via the traditional back‐EMF‐based sensorless control strategies in which the back‐EMF may be even undetectable at high‐speed. The proposed rotor‐flux‐observer (RFO)‐based sensorless control method overcomes these problems, and meanwhile provides high‐resolution rotor position information for the phase‐advancing purpose.
Originality/value
The RFO‐based sensorless control is traditionally applied to PM brushless ac (BLAC) operations, where the motor voltage vector can be calculated from the inverter switching status. However, this is not readily applicable to a BLDC motor since the voltage of the floating phase cannot be calculated. Moreover, during high‐speed operation, the microprocessor may not be sufficiently fast to calculate the high‐resolution rotor position. Therefore, in this paper, it is proposed to use hardware to observe the rotor‐flux‐vector. The microprocessor only samples the vector's α‐ and β‐components and calculates the phase angle, hence, its burden is low. The proposed method is validated with a 1.8 kW 85,000 rpm BLDC motor system.
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Nian Cai, Yuchao Chen, Gen Liu, Guandong Cen, Han Wang and Xindu Chen
This paper aims to design an automatic inspection system for the characters on tire molds, which involves a vision-based inspection method for the characters on tire molds.
Abstract
Purpose
This paper aims to design an automatic inspection system for the characters on tire molds, which involves a vision-based inspection method for the characters on tire molds.
Design/methodology/approach
An automatic inspection equipment is designed according to the features of the tire mold. To implement the inspection task, the corresponding image processing methods are designed, including image preprocessing, image mosaic, image locating and character inspection. Image preprocessing mainly contains fitting the contours of the acquired tire mold images and those of the computer aided design (CAD) as the arcs of two circles and polar transformation of the acquired images and the CAD. Then, the authors propose a novel framework to locate the acquired images into the corresponding mosaicked tire mold image. Finally, a character inspection scheme is proposed by combining an support-vector-machine-based character recognition method and a string matching approach. At the stages of image locating and character inspection, image mosaic is simultaneously used to label the defects in the mosaicked tire mold image, which is based on histograms-of-gradients features.
Findings
The experimental results indicate that the designed automatic inspection system can inspect the characters on the tire mold with a high accuracy at a reasonable time consumption.
Practical implications
The designed automatic inspection system can detect the carving faults for the characters on the tire molds, which are the cases that the characters are wrongly added, deleted or modified on the tire mold.
Originality/value
To the best of the authors’ knowledge, this is the first automatic vision-based inspection system for the characters on tire molds. An inspection equipment is designed and many novel image processing methods are proposed to implement the inspection task. The designed system can be widely applied in the industry.
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A Soviet type of “shock therapy” is not likely to takeplace in China since a gradual economic reform has already improved theoverall economic conditions. Argues that, for further…
Abstract
A Soviet type of “shock therapy” is not likely to take place in China since a gradual economic reform has already improved the overall economic conditions. Argues that, for further economic development, however, the Chinese communists must recognize two basic facts: (1) Chinese communism has already fulfilled its historical mission by expelling foreign imperialism and domestic feudalism; (2) Marxism and Leninism are of foreign origin. This recognition is able to pave the way for a final adoption of the Taiwanese model of economic development, which is based on the ideas developed by Sun Yat‐Sen, who had never stopped to insist that modernization should not abandon the Chinese tradition, especially Confucianism.
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