Yanmei Yang, Hongsheng Su and Kan Wang
The purpose of this paper is to investigate the reliable and steady working conditions of train agent systems while connected to the internet. The train agents can provide more…
Abstract
Purpose
The purpose of this paper is to investigate the reliable and steady working conditions of train agent systems while connected to the internet. The train agents can provide more accurate assistant navigation service and more useful “live” information service to ensure traveling crane safety. However, all these services seriously rely on reliability and stability of communication quality of the train agents. To ensure the stable and continuous work of the train agents, the stochastic model of the train agent communication is investigated in this paper.
Design/methodology/approach
According to Markov theory, the stochastic model of the train agent communication is established, the reliability of which is also investigated, the availability and mean‐link interruption times in steady state are then given out.
Findings
In the end, the steady working condition and controllability of the train agents are discussed.
Research limitations/implications
The correctness of the mathematic model in the main limitation based on which the model will be applied.
Practical implications
A very useful model for the train agent systems description.
Originality/value
From the angle of stochastic model, the steady working condition and controllability of the train agent are given out connected to the internet. It has enormous instruction significance to those special mobile agents design such as the train agents, the plane agents, the ship agents, etc.
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Jieren Yang, Ruirun Chen, Hongsheng Ding, Yanqing Su, Guo Jingjie, Feng Huang and Hengzhi Fu
The purpose of this paper is to introduce a numerical calculation method to study the uniformity of the magnetic field in a cold crucible used for directional solidification (DS…
Abstract
Purpose
The purpose of this paper is to introduce a numerical calculation method to study the uniformity of the magnetic field in a cold crucible used for directional solidification (DS) and provide information for designing a cold crucible that can induce a uniform magnetic field.
Design/methodology/approach
To obtain the characteristics of the magnetic field in a cold crucible and its influence on the directional solidification processing, based on experimental verification, 3‐D finite element (FE) models with different crucible configuration‐elements and power parameters were established to study the uniformity of the magnetic field in a cold crucible. In addition, different TiAl ingots were directionally solidified with different cold crucibles, and the solid/liquid (S/L) interfaced were examined to investigate the effect of the magnetic field on the macrostructure of those ingots.
Findings
The uniformity of the magnetic field in a given domain can be quantitatively analyzed by statistical methods. Numerical calculation results showed that the uniformity of the magnetic field can be improved by optimizing the crucible configuration and adopting lower frequency. Better uniformity of the magnetic field in a cold crucible is beneficial to directional solidification.
Originality/value
The calculation of the uniformity of the magnetic field is proposed as a method for quantitative study of the distribution characteristics of the magnetic field in a cold crucible. The relationship between the S/L interfaces of TiAl ingots and the uniformity of the magnetic field is initially characterised; additionally, techniques for improving the uniformity of the magnetic field in a cold crucible are suggested.
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Tu Hongsheng, Huang Changwen and Guo Chenye
Currently, the existing similar simulation is still limited in the following aspects: un-rotatable laboratory devices, the difficulty in the pavement on steep seams and great…
Abstract
Purpose
Currently, the existing similar simulation is still limited in the following aspects: un-rotatable laboratory devices, the difficulty in the pavement on steep seams and great error of the experimental data.
Design/methodology/approach
To address above-mentioned problems, this study combined theoretical analysis and numerical simulation and developed a rotatable experimental system for similar simulation on steep coal seam mining on the premise of ensuring experimental safety.
Findings
The present experimental system mainly consists of the model support, the rotation system and the bearing system. By taking into account the experimental requirements and actual laboratory space, the sizes of the model support and the bearing system were determined. Considering the requirements in space limit and rotation stability, the rotation mode of vertical sliding on the left side and the horizontal sliding on the lower side was designed.
Originality/value
Using programmable logic controller automatic angle control technology, the rotation angle, velocity and displacement of the model can be automatically adjusted and controlled so as to achieve safe rotation and precise control. Finally, the calculation method of the mass of the required similar materials for paving the coal strata at different inclination angles and in different horizons was analyzed, and the related mass proportion calculation software was developed.
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Abstract
Purpose
The aim of this paper is to synthesize graphene-modified titanium dioxide (GR-TiO2) nanorod arrays nanocomposite films, so that these can enhance the photocatalytic properties of titanium dioxide and overcome the problem of difficult separation and recovery of photocatalysts.
Design/methodology/approach
The GR-TiO2 nanocomposite films were synthesized via hydrothermal method and spin-coating. The obtained samples were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), ultraviolet–visible (UV-Vis) diffuse reflectance spectrum and Raman spectrum. The photocatalytic performance of the GR-TiO2 nanocomposite films for degrading Rhodamin B under ultraviolet (UV) was studied by a UV-Vis spectrophotometer. The photocatalytic enhancement mechanism of graphene was studied by photoelectrochemical analysis.
Findings
The introduction of graphene expanded the range of the optical response of TiO2 nanorod arrays, improving the separation efficiency of the photogenerated electron-hole pairs, and thus dramatically increasing its photocatalytic performance.
Research limitations/implications
A simple and novel way for synthesizing GR-TiO2 nanocomposite films has enhanced the photocatalytic performance of TiO2.
Originality/value
The photocatalyst synthesized is easy to separate and recycle in the process of photocatalytic reaction, so it is possible to achieve industrialization.
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Pavel Baranov, Tamara Nesterenko, Evgenii Barbin, Aleksej Koleda, Shuji Tanaka, Takashiro Tsukamoto, Ivan Kulinich, Dmitry Zykov and Alexander Shelupanov
Technological capabilities of manufacturing microelectromechanical system (MEMS) gyroscopes are still insufficient if compared to manufacturing high-efficient gyroscopes and…
Abstract
Purpose
Technological capabilities of manufacturing microelectromechanical system (MEMS) gyroscopes are still insufficient if compared to manufacturing high-efficient gyroscopes and accelerometers. This creates weaknesses in their mechanical structure and restrictions in the measurement accuracy, stability and reliability of MEMS gyroscopes and accelerometers. This paper aims to develop a new architectural solutions for optimization of MEMS gyroscopes and accelerometers and propose a multi-axis MEMS inertial module combining the functions of gyroscope and accelerometer.
Design/methodology/approach
The finite element modeling (FEM) and the modal analysis in FEM are used for sensing, drive and control electrode capacitances of the multi-axis MEMS inertial module with the proposed new architecture. The description is given to its step-by-step process of manufacturing. Algorithms are developed to detect its angular rates and linear acceleration along three Cartesian axes.
Findings
Experimental results are obtained for eigenfrequencies and capacitances of sensing, drive and control electrodes for 50 manufactured prototypes of the silicon electromechanical sensor (SES). For 42 SES prototypes, a good match is observed between the calculated and simulated capacitance values of comb electrodes. Thus, the mean-square deviation is not over 20 per cent. The maximum difference between the calculated and simulated eigenfrequencies in the drive channel of 11 SES prototypes is not over 3 per cent. The same difference is detected for eigenfrequencies in the first sensing channel of 17 SES prototypes.
Originality/value
This study shows a way to design and optimize the structure and theoretical background for the development of the MEMS inertial module combining the functions of gyroscope and accelerometer. The obtained results will improve and expand the manufacturing technology of MEMS gyroscopes and accelerometers.