According to unearthed materials of braids, hand braiding originate in the last stage of the Old Stone Age China and has a history of over 7000 years, which remains a unique…
Abstract
According to unearthed materials of braids, hand braiding originate in the last stage of the Old Stone Age China and has a history of over 7000 years, which remains a unique handicraft in our society. In terms of the arrangement of yarns, braiding can be categorized into two kinds of techniques: double system braiding and single system. In ancient China, most braids were made by double system braiding. The technique of single system braiding was at its peak of development in the Zhou dynasty. Around the Han dynasty, diagonal braiding and twist braiding were in fashion, and a complex braiding technique of the combining of the two types of braiding was invented. Since the Shang dynasty, the application of braiding has been limited to narrow fabrics, shaped products, and some special trimmings, such as knots.
Double system braiding was directly responsible for the development of machine weaving. Loop braiding and crook braiding are similar to modern knitting and crocheting in many aspects. The scope of braiding application has now diminished, but its technical and cultural significance remains.
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Gives an in depth view of the strategies pursued by the world’s leading chief executive officers in an attempt to provide guidance to new chief executives of today. Considers the…
Abstract
Gives an in depth view of the strategies pursued by the world’s leading chief executive officers in an attempt to provide guidance to new chief executives of today. Considers the marketing strategies employed, together with the organizational structures used and looks at the universal concepts that can be applied to any product. Uses anecdotal evidence to formulate a number of theories which can be used to compare your company with the best in the world. Presents initial survival strategies and then looks at ways companies can broaden their boundaries through manipulation and choice. Covers a huge variety of case studies and examples together with a substantial question and answer section.
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Khalid Almarri, Saleh Alzahrani and Halim Boussabaine
A unique aspect of PPP is the opportunity for the transfer of risk ownership to the private sector. The purpose of this paper is to investigate how risk cost influences risk…
Abstract
Purpose
A unique aspect of PPP is the opportunity for the transfer of risk ownership to the private sector. The purpose of this paper is to investigate how risk cost influences risk allocation.
Design/methodology/approach
A questionnaire survey was used to collect data. The questionnaire included nine sub-categories of risks. To quantify the influence of risk cost on risk allocation, a dependency risk matrix was employed. Heat maps techniques were used to visualise the results of the survey.
Findings
The findings show which risks within the endogenous or exogenous groups are to be allocated to the public sector, the private sector, or to be shared. The finding from this research provides a baseline for the PPP stakeholders in developing guidelines for estimating the value of risk costs in the risks register as well as serving as a mechanism for risk allocation.
Research limitations/implications
The context of the study may limit the generalisability of the results.
Practical implications
The study provides practical guidance to PPP stakeholders on risk allocation appetite.
Originality/value
This study extends the processes and methods by which PPP project’s risk is allocated to create a better value for all the stakeholders.
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Miao Ye, Lin Qiang Huang, Xiao Li Wang, Yong Wang, Qiu Xiang Jiang and Hong Bing Qiu
A cross-domain intelligent software-defined network (SDN) routing method based on a proposed multiagent deep reinforcement learning (MDRL) method is developed.
Abstract
Purpose
A cross-domain intelligent software-defined network (SDN) routing method based on a proposed multiagent deep reinforcement learning (MDRL) method is developed.
Design/methodology/approach
First, the network is divided into multiple subdomains managed by multiple local controllers, and the state information of each subdomain is flexibly obtained by the designed SDN multithreaded network measurement mechanism. Then, a cooperative communication module is designed to realize message transmission and message synchronization between the root and local controllers, and socket technology is used to ensure the reliability and stability of message transmission between multiple controllers to acquire global network state information in real time. Finally, after the optimal intradomain and interdomain routing paths are adaptively generated by the agents in the root and local controllers, a network traffic state prediction mechanism is designed to improve awareness of the cross-domain intelligent routing method and enable the generation of the optimal routing paths in the global network in real time.
Findings
Experimental results show that the proposed cross-domain intelligent routing method can significantly improve the network throughput and reduce the network delay and packet loss rate compared to those of the Dijkstra and open shortest path first (OSPF) routing methods.
Originality/value
Message transmission and message synchronization for multicontroller interdomain routing in SDN have long adaptation times and slow convergence speeds, coupled with the shortcomings of traditional interdomain routing methods, such as cumbersome configuration and inflexible acquisition of network state information. These drawbacks make it difficult to obtain global state information about the network, and the optimal routing decision cannot be made in real time, affecting network performance. This paper proposes a cross-domain intelligent SDN routing method based on a proposed MDRL method. First, the network is divided into multiple subdomains managed by multiple local controllers, and the state information of each subdomain is flexibly obtained by the designed SDN multithreaded network measurement mechanism. Then, a cooperative communication module is designed to realize message transmission and message synchronization between root and local controllers, and socket technology is used to ensure the reliability and stability of message transmission between multiple controllers to realize the real-time acquisition of global network state information. Finally, after the optimal intradomain and interdomain routing paths are adaptively generated by the agents in the root and local controllers, a prediction mechanism for the network traffic state is designed to improve awareness of the cross-domain intelligent routing method and enable the generation of the optimal routing paths in the global network in real time. Experimental results show that the proposed cross-domain intelligent routing method can significantly improve the network throughput and reduce the network delay and packet loss rate compared to those of the Dijkstra and OSPF routing methods.
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Although an important facet of modernist architecture in which function plays a prominent role, building flexibility is not entirely a new concept. Its relevance transcends…
Abstract
Although an important facet of modernist architecture in which function plays a prominent role, building flexibility is not entirely a new concept. Its relevance transcends generations, allowing space and structure to evolve through time. This paper investigates the relationship among main building structures, infill elements, and space by studying examples in ancient Chinese architecture. It reveals the role of building owners, users, and craftsmen from a survey of historical documentation. In studying these examples, it is concluded that craftsmen in ancient China were involved not only during the construction phase but throughout the period of use as well. Thus, in select cases, the relationship between craftsmen and owners or users had been preserved for generations. Finally, this paper suggests potential strategies for the building industry and technology in the move towards sustainable development.
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Lijun Dong, Naichao Chen, Jiawen Liang, Tingting Li, Zhanlin Yan and Bing Zhang
The purpose of this study is to provide an in-depth understanding about the indoor-orbital electrical inspection robot, which is useful for motivating the further investigation on…
Abstract
Purpose
The purpose of this study is to provide an in-depth understanding about the indoor-orbital electrical inspection robot, which is useful for motivating the further investigation on the inspection of electrical equipment. Currently, electric energy has a strong correlation with the economic development of the country. Intelligent substations play an important role in the transmission and distribution of the electricity; the maintenance of the substation has attracted intensive attention due to the requirement of reliability and safety. The indoor-orbital electrical inspection robot has increasingly become the main tool to realize the unmanned. Hence, a systematic review is conducted systematically reviewing the current technical status of the indoor-orbital electrical inspection robot and discuss the existed problems.
Design/methodology/approach
In this paper, the most essential achievements in the field of indoor-orbital electrical inspection robots were reported to present the current status, and the mechanical structures and key inspective technologies were also discussed.
Findings
Four recommendations are provided from the analyzed review, which have made constructive comments on the overall structural design, functionality, intelligence and future development direction of the indoor-orbital electrical inspection robot, respectively.
Originality/value
To the best of the authors’ knowledge, this is the first systematic review study on indoor-orbital electrical inspection robots; it fills the theoretical gap and proffers design ideas and directions for the development of the indoor-orbital electrical inspection robot.
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Liuyong Wang, Qi Wu, Ziming Song, Yue Li, Xuewen Li, Bing Tu and Yulong Li
This study aims to investigate the wetting behavior of AgCuTi and AgCu filler metals on selective laser melting (SLMed) Ti/TiB2, and to analyze the microstructure and fracture…
Abstract
Purpose
This study aims to investigate the wetting behavior of AgCuTi and AgCu filler metals on selective laser melting (SLMed) Ti/TiB2, and to analyze the microstructure and fracture characteristics of SLMed Ti/TiB2/AgCuTi or AgCu alloy/SLMed Ti/TiB2 brazed joints. The wetting behavior of AgCuTi and AgCu filler metals on the selective laser melted (SLMed) Ti/TiB2 has been studied. The analysis of microstructures and fracture characteristics in vacuum-brazed SLMed Ti/TiB2 substrate, using AgCuTi and AgCu filler metals, has been conducted to elucidate the influence of brazing temperature and alloy composition on the shear strength of the brazed joints.
Design/methodology/approach
Brazing SLMed-Ti/TiB2 in a vacuum using AgCuTi and AgCu filler metals, this study aims to explore the optimal parameters for brazed joints at various brazing temperatures (800°C−950°C).
Findings
The findings suggest that elevated brazing temperatures lead to a more extensive diffusion region in the joint as a result of the partial melting of the filler metal. The joint composition changes from distinct Ti2Cu layer/TiCu layer/filler metal to a-Ti (ss) + ß-Ti (ss)/TiCu. As the brazing temperature increases, the fracture mode shifts from brittle cleavage to ductile fracture, mainly attributed to a decrease in the CuTi within the brazed joint. This change in fracture behavior indicates an improvement in the ductility and toughness of the joint.
Originality/value
The originality of this study lies in the comprehensive analysis of the microstructure and shear strength of vacuum brazing SLMed Ti/TiB2 using AgCuTi and AgCu filler metals.
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Le Yun, Jingyuan Wan, Ge Wang, Ju Bai and Bing Zhang
The purpose of this paper is to analyze the relationship between the demographic characteristics of top management teams (TMTs) (i.e. age, gender, administrative level, senior…
Abstract
Purpose
The purpose of this paper is to analyze the relationship between the demographic characteristics of top management teams (TMTs) (i.e. age, gender, administrative level, senior management experience and educational background) and megaproject performance, with respect to schedule, cost, quality, safety and technological innovation. The results shed new light on the effectiveness of different types of TMT.
Design/methodology/approach
This paper collected secondary and objective data from 208 TMT members in 42 megaprojects and employed hierarchical regression analysis to test the research hypotheses.
Findings
The findings revealed that age has a significant influence on schedule performance; gender has a significant influence on safety performance; senior management experience has a significant influence on cost performance; and educational background has a significant influence on both schedule and technological innovation performance. However, this study did not find evidence of a significant relationship between the administrative level and megaproject performance.
Research limitations/implications
This paper mainly focused on China’s megaprojects, most of which are globally influential (e.g. Hong Kong–Zhuhai–Macao Bridge and Shanghai Expo), however this sampling approach still limits the generalizability of research findings to other contexts.
Originality/value
The results of this paper contribute to a better understanding of how management team capabilities translate into better project achievements. This paper also provides implications on the criteria for selecting top megaproject managers to optimize the composition of the TMT and realize better performance.
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Shan Li, Li Juan Zheng, Cheng Yong Wang, Bing Miao Liao and Lianyu Fu
In an integrated circuit (IC) substrate, more fillers, including talcum powder and aluminium hydroxide, are added, which leads to much higher rigidity and hardness compared with a…
Abstract
Purpose
In an integrated circuit (IC) substrate, more fillers, including talcum powder and aluminium hydroxide, are added, which leads to much higher rigidity and hardness compared with a traditional printed circuit board. However, the micro drilling of IC substrates is harder. This paper aims to test the drilling process of IC substrates to improve the drilling process and the micro hole quality.
Design/methodology/approach
Substrate drilling by a micro drill with 0.11-mm diameter was used under several drilling conditions. The influence of drilling conditions on the drilling process was observed. Drilling forces, drill wear and micro hole quality were also studied.
Findings
The deformation circle around holes, hole location accuracy, bugle hole and burrs were the major defects of micro holes that were observed during the drilling of the substrate. Reducing the drilling force and drill wear was the effective way to improve hole quality.
Originality/value
The technology and manufacturing of IC substrates has been little investigated. Research data on drilling IC substrates is lacking. The micro hole quality directly affects the reliability of IC substrates. Thus, improving the drilling technology of IC substrates is very important.
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Hui Wang, Jingsong Peng, Bing Zhao, Xin-Dong Zhang, Jie Yu, Yuan Li and Mao-Min Wang
Near-net-shaped processes of jet engine blade have better performance in both reducing the material waste during production and improving work reliability in service, while the…
Abstract
Purpose
Near-net-shaped processes of jet engine blade have better performance in both reducing the material waste during production and improving work reliability in service, while the geometric features of blade, both sculptured surface and thin-walled shape, make the precise machining of blade challenging and difficult owing to its dynamics behaviors under complex clamping and machining loads. This paper aims to present a fundamental approach on modeling and performance analysis of the blade–fixture system.
Design/methodology/approach
A computerized framework on the complex blade–fixture dynamic behavior has been developed. Theoretical mechanic analysis on blade fixturing and machining is proposed with an especial emphasis on the boundary conditions of the blade–fixture system. Then the finite element analysis (FEA) method is used to simulate the variation trend of preloads, stiffness and blade distortion. The strong influence of parameters of workpiece–fixture configuration on blade distortion and machining error is investigated.
Findings
With a case of real jet engine blade machining, the experimental results and theoretical predictions suggest good agreement on their variation tendency. The loaded pressure of clamps has a critical influence on the total stiff performance of the blade–fixture system, and the profile error of the blade contributes much to the inconsistency in geometric dimension and surface integrity of blades’ machining. In the end, the results also validate the effectiveness of this methodology to predict and improve the performance of the blade–fixture configuration design.
Originality/value
The adaptive machining of near-net-shaped jet engine blade is a new high-performance manufacturing technology in aerospace production. This study provides a fundamental methodology for the performance analysis of blade-fixture system, to clear the variation law of blade distortion during preloading and machining, which will contribute to minimize the machining error and improve productivity.