Jiajun Tan, Wai Peng Wong, Chee Keong Tan, Suriyan Jomthanachai and Chee Peng Lim
Technology is the lifeline for the logistics industry, and it has been immensely disrupted by the emerging blockchain technology. This paper has two main objectives. The first is…
Abstract
Purpose
Technology is the lifeline for the logistics industry, and it has been immensely disrupted by the emerging blockchain technology. This paper has two main objectives. The first is to explore how the current blockchain technology can be implemented in the logistics industry with the aim of improving logistic services amongst the network of logistics service providers (LSPs). The second is to propose the development of a blockchain model for the small and medium logistics service supply chain.
Design/methodology/approach
A prototype blockchain-based logistics system has been created and tested in a case study with a real logistics company. The primary technologies for developing a blockchain model on the Hyperledger platform as well as how the system is designed based on the logistics service flow are explained.
Findings
The study has resulted in the successful implementation of the proposed prototype blockchain-based logistics system. In particular, the case company has managed to fully utilise the developed tracking and tracing system. Whilst utilising the prototype, the participants have been able to fulfil their responsibilities in an effective manner. The performance of LSPs has improved following the World Bank Logistics Performance Index (LPI) criteria.
Originality/value
This paper contributes to current research in the application of blockchain technologies in the domain of logistics and the supply chain to progress LSPs towards Logistics 4.0. The current frameworks for Logistics 4.0 and how blockchain as a disruptive technology revolutionises logistic services are reviewed. In addition, this paper highlights the benefits of blockchain technology that LSPs can leverage to further improve their performance based on the LPI criteria.
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Linlin Li and Jiajun Yang
The purpose of this paper is to study the effects of surface roughness on the lubrication performances of the linear rolling guide, which provides theoretical guidance for its…
Abstract
Purpose
The purpose of this paper is to study the effects of surface roughness on the lubrication performances of the linear rolling guide, which provides theoretical guidance for its lubrication design.
Design/methodology/approach
The two-variable Weierstrass–Mandelbrot function is used to represent the random and multi-scale characteristics of the rough surface topography. The elastohydrodynamic lubrication (EHL) model of contact between the steel ball and raceway is built. The full numerical solutions of the pressure and film thickness are obtained by using the multi-grid technique.
Findings
The presence of surface roughness can cause the random fluctuations of the pressure and film thickness, and the fluctuations can become more dramatic for the rougher surfaces. It is also found that the film characteristics can be influenced significantly by the working conditions, such as the load, velocity and ambient viscosity of lubricants.
Originality/value
Characterization of surface topographies regarding EHL problems in the past studies cannot reflect random and multi-scale characteristics. In this paper, the fractal-based method is introduced to analysis of the point-contact micro-EHL. It reveals the mechanism and law of contact lubrication influenced by the fractal surface roughness and enriches the lubrication principle and method of the linear rolling guide.
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Qun Shi, Wangda Ying, Lei Lv and Jiajun Xie
This paper aims to present an intelligent motion attitude control algorithm, which is used to solve the poor precision problems of motion-manipulation control and the problems of…
Abstract
Purpose
This paper aims to present an intelligent motion attitude control algorithm, which is used to solve the poor precision problems of motion-manipulation control and the problems of motion balance of humanoid robots. Aiming at the problems of a few physical training samples and low efficiency, this paper proposes an offline pre-training of the attitude controller using the identification model as a priori knowledge of online training in the real physical environment.
Design/methodology/approach
The deep reinforcement learning (DRL) of continuous motion and continuous state space is applied to motion attitude control of humanoid robots and the robot motion intelligent attitude controller is constructed. Combined with the stability analysis of the training process and control process, the stability constraints of the training process and control process are established and the correctness of the constraints is demonstrated in the experiment.
Findings
Comparing with the proportion integration differentiation (PID) controller, PID + MPC controller and MPC + DOB controller in the humanoid robots environment transition walking experiment, the standard deviation of the tracking error of robots’ upper body pitch attitude trajectory under the control of the intelligent attitude controller is reduced by 60.37 per cent, 44.17 per cent and 26.58 per cent.
Originality/value
Using an intelligent motion attitude control algorithm to deal with the strong coupling nonlinear problem in biped robots walking can simplify the control process. The offline pre-training of the attitude controller using the identification model as a priori knowledge of online training in the real physical environment makes up the problems of a few physical training samples and low efficiency. The result of using the theory described in this paper shows the performance of the motion-manipulation control precision and motion balance of humanoid robots and provides some inspiration for the application of using DRL in biped robots walking attitude control.
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Guisheng Gan, Hao Yang, Jie Luo, Yongchong Ma, Jiajun Zhang, Xin Liu, Qiao He, Leqi Li and Dayong Cheng
The purpose of this study was to investigate the effects of aging time on the microstructure, mechanical properties and fracture morphology of Cu/Zn160%SAC0307/Al solder joints…
Abstract
Purpose
The purpose of this study was to investigate the effects of aging time on the microstructure, mechanical properties and fracture morphology of Cu/Zn160%SAC0307/Al solder joints produced through solid-state bonding.
Design/methodology/approach
Zn particles with a size of 1 µm and Sn-0.3Ag-0.7Cu (SAC0307) particles ranging from 20 to 38 µm were used to achieve Cu/Al micro-connections using ultrasonic assistance at a temperature of 180 °C, followed by aging treatment at 150 °C to enhance the quality of Cu/Al joints. Scanning electron microscopy was used for observing and analyzing the solder seam, interface microstructure, and fracture morphology. The structural composition was determined using energy dispersive spectroscopy, while a PTR-1102 bonding tester was used to measure the average shear strength.
Findings
The results indicated that the intermetallic compounds formed at the interface between Cu substrates and solder metal primarily consisted of smooth Cu5Zn8. The Al-side interface mainly comprises an Al-Sn-Zn solid solution, with Zn-Sn-Cu phases forming between SAC0307 particles at 180 °C. During the aging process, atomic diffusion was accelerated, leading to improved connection quality. The shear strength of the joints initially increased before decreasing as aging time progressed; it peaked at 32.92 MPa after 24 h – an increase of 76.8% compared to as-received joints. After reaching stability at 96 h, there was still a notable increase in shear strength by 48.4% relative to as-received joints.
Originality/value
This study further explores the strengthening mechanisms associated with solid-state bonded Cu/SACZ/Al joints through aging processes. Joints created via solid-state bonding demonstrate superior reliability compared to traditional soldered connections. It is anticipated that insights gained from this research will contribute valuable knowledge toward developing low-temperature soldering methodologies for heterogeneous materials.
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Yee Sye Lee, Ali Rashidi, Amin Talei, Mehrdad Arashpour and Farzad Pour Rahimian
In recent years, deep learning and extended reality (XR) technologies have gained popularity in the built environment, especially in construction engineering and management. A…
Abstract
Purpose
In recent years, deep learning and extended reality (XR) technologies have gained popularity in the built environment, especially in construction engineering and management. A significant amount of research efforts has been thus dedicated to the automation of construction-related activities and visualization of the construction process. The purpose of this study is to investigate potential research opportunities in the integration of deep learning and XR technologies in construction engineering and management.
Design/methodology/approach
This study presents a literature review of 164 research articles published in Scopus from 2006 to 2021, based on strict data acquisition criteria. A mixed review method, consisting of a scientometric analysis and systematic review, is conducted in this study to identify research gaps and propose future research directions.
Findings
The proposed research directions can be categorized into four areas, including realism of training simulations; integration of visual and audio-based classification; automated hazard detection in head-mounted displays (HMDs); and context awareness in HMDs.
Originality/value
This study contributes to the body of knowledge by identifying the necessity of integrating deep learning and XR technologies in facilitating the construction engineering and management process.