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1 – 10 of 12
Article
Publication date: 4 July 2018

Yanjun Lu, Li Xiong, Yongfang Zhang, Peijin Zhang, Cheng Liu, Sha Li and Jianxiong Kang

This paper aims to introduce a novel four-dimensional hyper-chaotic system with different hyper-chaotic attractors as certain parameters vary. The typical dynamical behaviors of…

Abstract

Purpose

This paper aims to introduce a novel four-dimensional hyper-chaotic system with different hyper-chaotic attractors as certain parameters vary. The typical dynamical behaviors of the new hyper-chaotic system are discussed in detail. The control problem of these hyper-chaotic attractors is also investigated analytically and numerically. Then, two novel electronic circuits of the proposed hyper-chaotic system with different parameters are presented and realized using physical components.

Design/methodology/approach

The adaptive control method is derived to achieve chaotic synchronization and anti-synchronization of the novel hyper-chaotic system with unknown parameters by making the synchronization and anti-synchronization error systems asymptotically stable at the origin based on Lyapunov stability theory. Then, two novel electronic circuits of the proposed hyper-chaotic system with different parameters are presented and realized using physical components. Multisim simulations and electronic circuit experiments are consistent with MATLAB simulation results and they verify the existence of these hyper-chaotic attractors.

Findings

Comparisons among MATLAB simulations, Multisim simulation results and physical experimental results show that they are consistent with each other and demonstrate that changing attractors of the hyper-chaotic system exist.

Originality/value

The goal of this paper is to construct a new four-dimensional hyper-chaotic system with different attractors as certain parameters vary. The adaptive synchronization and anti-synchronization laws of the novel hyper-chaotic system are established based on Lyapunov stability theory. The corresponding electronic circuits for the novel hyper-chaotic system with different attractors are also implemented to illustrate the accuracy and efficiency of chaotic circuit design.

Details

Circuit World, vol. 44 no. 3
Type: Research Article
ISSN: 0305-6120

Keywords

Article
Publication date: 5 October 2021

He-Wei Zhao and Li-bin Yang

This paper aims to discuss the precise altitude and velocity tracking control of a hypersonic vehicle, a global adaptive neural backstepping controller was studied based on a…

Abstract

Purpose

This paper aims to discuss the precise altitude and velocity tracking control of a hypersonic vehicle, a global adaptive neural backstepping controller was studied based on a disturbance observer (DOB).

Design/methodology/approach

The DOB combined with a radial basis function (RBF) neural network (NN) was used to estimate the disturbance terms that are generated by the flexible modes of the hypersonic vehicle system. A global adaptive neural method was introduced to approximate the unknown system dynamics, with robust control terms pulling the system transient states back into the neural approximation domain externally.

Findings

The globally uniformly ultimately bounded for all signals of a closed-loop system can be guaranteed by the proposed control algorithm. Additionally, the command filtered backstepping methods can avoid the explosion of the complexity problem caused by the backstepping design process. In addition, the effectiveness of the proposed controller can be verified by the simulation used in this study.

Research limitations/implications

Normally lateral dynamics issue should be discussed in the process of control system designed, the lateral dynamics are not included in the nonlinear dynamic model of hypersonic vehicle used in this paper, merely the longitudinal flight dynamics are discussed in this paper.

Originality/value

The flexible states in rigid modes are considered as the disturbance of the system, which is estimated by structuring DOB with NN approximations. The compensating tracking error and prediction error are used in the update law of RBF NN weight. The differential explosions complexity derived from the backstepping procedure is dealt with by using command filters.

Details

Aircraft Engineering and Aerospace Technology, vol. 94 no. 4
Type: Research Article
ISSN: 1748-8842

Keywords

Article
Publication date: 9 May 2022

Yanjun Zhang, Shuangfeng Wang and Zhuming Liu

The purpose of this study is to conduct research on a new kind of division microchannel heat sink (D-MCHS), which can distribute cooling water along the channel-length direction…

Abstract

Purpose

The purpose of this study is to conduct research on a new kind of division microchannel heat sink (D-MCHS), which can distribute cooling water along the channel-length direction. First, the pressure drops in the D-MCHS with different division region numbers were compared. Then, the cooling performance of the D-MCHS with different division region numbers was also comparatively investigated. Finally, the temperature distribution on the bottom surface of the D-MCHS was analyzed.

Design/methodology/approach

First, experiments were conducted to investigate the numerical calculation method. Then, a three-dimensional steady, single-phase, laminar flow and solid-fluid conjugate heat transfer numerical model was used to research the flow and heat transfer characteristics in microchannels.

Findings

The pressure drop in the D-MCHS could be reduced by increasing the number of divided flow regions along the channel-length direction. The bottom average temperature of the D-MCHS could be simultaneously affected by the number of divided flow regions and the water flow rate. The thermal uniformity performance of the D-MCHS could be improved by increasing the number of division flow regions. The number of low-temperature and high-temperature areas on the bottom surface of the D-MCHS is corresponding to the division flow region number.

Originality/value

The D-MCHS exhibited a positive effect on the pressure drop decrease and thermal uniformity improvement. It not only keeps the electronic module working in a secure temperature environment but also consumes less pump power for a lower pressure drop.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 32 no. 12
Type: Research Article
ISSN: 0961-5539

Keywords

Article
Publication date: 4 January 2018

Yanjun Xie and Jiaojiao Sun

The purpose of this paper is to explore the actions of different senses on visitors’ embodied experience in dark tourism “field,” including embodied emotions/cognitions.

Abstract

Purpose

The purpose of this paper is to explore the actions of different senses on visitors’ embodied experience in dark tourism “field,” including embodied emotions/cognitions.

Design/methodology/approach

This research uses qualitative analysis by applying tourists’ reviews from two main Chinese tourism websites and the software of MAXQDA. It identifies the senses applied in the embodiment process in dark tourism “field” and matches these senses to the specific types of embodied emotions/cognitions.

Findings

This research identifies four main senses. The visual sense has the greatest influence on 27 embodied emotions and 7 embodied cognitions. Auditory and temperature sense create particular emotions. This research also points out the phenomenon of “banned behavior.” At last, to achieve accessibility/acceptability, Nanjing Memorial Hall applies two strategies to distance the extreme historical events from visitors: the construction of aesthetic elements and the way it shows historical objects.

Research limitations/implications

It uses both qualitative and quantitative data to identify the classifications and degrees of senses, emotions and cognitions as well as the relations between them. However, there are difficulties in the coding process because of the language differences, which requires a good understanding of the context of the tourism experience.

Practical implications

The research results could be used as a psychological reference and in the design of dark tourism product.

Social implications

It provides a specific understanding of the way in which visitors interact with dark tourism objects and environment.

Originality/value

This is the first research that explains the dark tourism experience from the perspective of embodiment. It provides conceptual as well as empirical reference for a new research topic.

Details

International Journal of Tourism Cities, vol. 4 no. 1
Type: Research Article
ISSN: 2056-5607

Keywords

Open Access
Article
Publication date: 15 July 2022

Jiansen Zhao, Xin Ma, Bing Yang, Yanjun Chen, Zhenzhen Zhou and Pangyi Xiao

Since many global path planning algorithms cannot achieve the planned path with both safety and economy, this study aims to propose a path planning method for unmanned vehicles…

Abstract

Purpose

Since many global path planning algorithms cannot achieve the planned path with both safety and economy, this study aims to propose a path planning method for unmanned vehicles with a controllable distance from obstacles.

Design/methodology/approach

First, combining satellite image and the Voronoi field algorithm (VFA) generates rasterized environmental information and establishes navigation area boundary. Second, establishing a hazard function associated with navigation area boundary improves the evaluation function of the A* algorithm and uses the improved A* algorithm for global path planning. Finally, to reduce the number of redundant nodes in the planned path and smooth the path, node optimization and gradient descent method (GDM) are used. Then, a continuous smooth path that meets the actual navigation requirements of unmanned vehicle is obtained.

Findings

The simulation experiment proved that the proposed global path planning method can realize the control of the distance between the planned path and the obstacle by setting different navigation area boundaries. The node reduction rate is between 33.52% and 73.15%, and the smoothness meets the navigation requirements. This method is reasonable and effective in the global path planning process of unmanned vehicle and can provide reference to unmanned vehicles’ autonomous obstacle avoidance decision-making.

Originality/value

This study establishes navigation area boundary for the environment based on the VFA and uses the improved A* algorithm to generate a navigation path that takes into account both safety and economy. This study also proposes a method to solve the redundancy of grid environment path nodes and large-angle steering and to smooth the path to improve the applicability of the proposed global path planning method. The proposed global path planning method solves the requirements of path safety and smoothness.

Details

Journal of Intelligent and Connected Vehicles, vol. 5 no. 3
Type: Research Article
ISSN: 2399-9802

Keywords

Article
Publication date: 8 November 2021

Xinxin Fu, Yanjun Chen, Minggang Sun and Tengjiang Yu

The service performance for colored asphalt pavement is inevitably affected by the addition of different colorants, especially the challenge of low temperature environment in cold…

Abstract

Purpose

The service performance for colored asphalt pavement is inevitably affected by the addition of different colorants, especially the challenge of low temperature environment in cold regions. Therefore, the purpose of study is to explore the effects of different colorants on the service performance for colored asphalt pavement and to provide a foundation for improving the applicability of colored asphalt pavement in cold regions.

Design/methodology/approach

In the study, three kinds of colorants (iron oxide red, iron oxide yellow, iron oxide green) were used to compare the influence of different colorants amounts and different colorants kinds on the service performance for colored asphalt pavement in cold regions. According to the characteristics of low temperature in cold regions, the effects of different colorants on the low temperature performance for colored asphalt pavement were studied.

Findings

The study shows that different colorants have different effects on the service performance of colored asphalt pavement. The high temperature performance increases with the increase of the colorants amount, but the low temperature performance is opposite. Additionally, the yellow colored asphalt pavement has more advantages of low temperature adaptation than the red and green colored asphalt pavement.

Originality/value

The study results provide a certain theoretical foundation for the application of colored asphalt pavement in cold regions and have certain value and significance for the further development of colored asphalt pavement.

Details

Pigment & Resin Technology, vol. 51 no. 6
Type: Research Article
ISSN: 0369-9420

Keywords

Open Access
Article
Publication date: 9 April 2020

Xiaodong Zhang, Ping Li, Xiaoning Ma and Yanjun Liu

The operating wagon records were produced from distinct railway information systems, which resulted in the wagon routing record with the same oriental destination (OD) was…

Abstract

Purpose

The operating wagon records were produced from distinct railway information systems, which resulted in the wagon routing record with the same oriental destination (OD) was different. This phenomenon has brought considerable difficulties to the railway wagon flow forecast. Some were because of poor data quality, which misled the actual prediction, while others were because of the existence of another actual wagon routings. This paper aims at finding all the wagon routing locus patterns from the history records, and thus puts forward an intelligent recognition method for the actual routing locus pattern of railway wagon flow based on SST algorithm.

Design/methodology/approach

Based on the big data of railway wagon flow records, the routing metadata model is constructed, and the historical data and real-time data are fused to improve the reliability of the path forecast results in the work of railway wagon flow forecast. Based on the division of spatial characteristics and the reduction of dimension in the distributary station, the improved Simhash algorithm is used to calculate the routing fingerprint. Combined with Squared Error Adjacency Matrix Clustering algorithm and Tarjan algorithm, the fingerprint similarity is calculated, the spatial characteristics are clustering and identified, the routing locus mode is formed and then the intelligent recognition of the actual wagon flow routing locus is realized.

Findings

This paper puts forward a more realistic method of railway wagon routing pattern recognition algorithm. The problem of traditional railway wagon routing planning is converted into the routing locus pattern recognition problem, and the wagon routing pattern of all OD streams is excavated from the historical data results. The analysis is carried out from three aspects: routing metadata, routing locus fingerprint and routing locus pattern. Then, the intelligent recognition SST-based algorithm of railway wagon routing locus pattern is proposed, which combines the history data and instant data to improve the reliability of the wagon routing selection result. Finally, railway wagon routing locus could be found out accurately, and the case study tests the validity of the algorithm.

Practical implications

Before the forecasting work of railway wagon flow, it needs to know how many kinds of wagon routing locus exist in a certain OD. Mining all the OD routing locus patterns from the railway wagon operating records is helpful to forecast the future routing combined with the wagon characteristics. The work of this paper is the basis of the railway wagon routing forecast.

Originality/value

As the basis of the railway wagon routing forecast, this research not only improves the accuracy and efficiency for the railway wagon routing forecast but also provides the further support of decision-making for the railway freight transportation organization.

Details

Smart and Resilient Transportation, vol. 2 no. 1
Type: Research Article
ISSN: 2632-0487

Keywords

Article
Publication date: 13 August 2019

Jun Yan, Haitao Hu, Zhixun Yang, Rui Wan and Yang Li

The purpose of this study is to present a multi-scale analysis methodology for calculating the effective stiffnesses and the micro stresses of helically wound structures…

234

Abstract

Purpose

The purpose of this study is to present a multi-scale analysis methodology for calculating the effective stiffnesses and the micro stresses of helically wound structures efficiently and accurately. The helically wound structure is widely applied in ocean and civil engineering as load-bearing structures with high flexibility, such as wire ropes, umbilical cables and flexible risers. Their structures are usually composed of a number of twisted subcomponents with relatively large slender ratio and have the one-dimensional periodic characteristic in the axial direction. As the huge difference between the axial length and the cross-section size of this type of structures, the finite element modeling and theoretical analysis based on some assumption are usually unavailable leading to the reduction of computability; even the optimization design becomes infeasible.

Design/methodology/approach

Based on the asymptotic homogenization theory, the one-dimensional periodic helically wound structure is equivalent to the one-dimensional homogeneous beam. A novel implementation of the homogenization is derived for the analysis of the effective mechanical properties of the helically wound structure, and the tensile, bending, torsional and coupling stiffness properties of the effective beam model are obtained. On this basis, a downscaling analysis formation for the micro-component stress in the one-dimensional periodic wound structure is constructed. The stress of micro-components in the specified geometry position of the helically wound structure is obtained basing on the asymptotic homogenization theory simultaneously.

Findings

By comparing with the result from finite element established accurately, the established multi-scale calculation method of the one-dimensional periodic helically wound structure is verified. The influence of size effects on the macro effective performance and the micro-component stress is discussed.

Originality/value

This paper will provide the theoretical basis for the efficient elastoplastic analysis of the helically wound structure, even the fatigue analysis. In addition, it is necessary to point out that the axial length of the helically wound structure in the general engineering problems that such as deep-sea risers and submarine cables.

Details

Engineering Computations, vol. 36 no. 8
Type: Research Article
ISSN: 0264-4401

Keywords

Article
Publication date: 12 October 2015

Fei Lanfang

This paper aims to examine how the law may play a role in mediation by paying special attention to how the law is excluded from and included in the process of court mediation in…

Abstract

Purpose

This paper aims to examine how the law may play a role in mediation by paying special attention to how the law is excluded from and included in the process of court mediation in China.

Design/methodology/approach

Hundred model court mediation cases selected by the Supreme People’s Court of China were analysed and reviewed.

Findings

The law is relevant in Chinese-style court mediation in four ways: first, judge-mediators are intended to use mediation to avoid resolving legal difficulties or challenges; second, judge-mediators consult the law to anticipate the losing party and the potential negative effects that might result from the adjudication; third, judge-mediators refer to the law to propose a mediation scheme or plan to guide the parties to settle; and fourth, judge-mediators would use the law as a bargaining chip in various ways to induce the parties to settle.

Research limitations/implications

Standards should be set out for the use of law in the mediation process to standardise judge-mediators’ actions, to ensure that the law is not used coercively to push settlement, which would undermine the parties’ self-determination in mediation.

Originality/value

This paper provides an original understanding of how law affects the process, the outcomes and, ultimately, the nature of settlements that parties achieve through court mediation in China. This study contributes to the literature that argues that ethical norms and legal standards should be set to direct those legal evaluations.

Details

International Journal of Conflict Management, vol. 26 no. 4
Type: Research Article
ISSN: 1044-4068

Keywords

Article
Publication date: 3 October 2019

ELyazid Akachar, Brahim Ouhbi and Bouchra Frikh

The purpose of this paper is to present an algorithm for detecting communities in social networks.

Abstract

Purpose

The purpose of this paper is to present an algorithm for detecting communities in social networks.

Design/methodology/approach

The majority of existing methods of community detection in social networks are based on structural information, and they neglect the content information. In this paper, the authors propose a novel approach that combines the content and structure information to discover more meaningful communities in social networks. To integrate the content information in the process of community detection, the authors propose to exploit the texts involved in social networks to identify the users’ topics of interest. These topics are detected based on the statistical and semantic measures, which allow us to divide the users into different groups so that each group represents a distinct topic. Then, the authors perform links analysis in each group to discover the users who are highly interconnected (communities).

Findings

To validate the performance of the approach, the authors carried out a set of experiments on four real life data sets, and they compared their method with classical methods that ignore the content information.

Originality/value

The experimental results demonstrate that the quality of community structure is improved when we take into account the content and structure information during the procedure of community detection.

Details

International Journal of Web Information Systems, vol. 16 no. 1
Type: Research Article
ISSN: 1744-0084

Keywords

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