Search results

1 – 10 of over 2000
Article
Publication date: 3 October 2019

Lei Zhu, Minghai Pan and Xiaohua Qiao

This paper aims to classify the inductorless Chua’s circuits into two types from the topological structures and construct a chaotic circuit under this new classification framework.

Abstract

Purpose

This paper aims to classify the inductorless Chua’s circuits into two types from the topological structures and construct a chaotic circuit under this new classification framework.

Design/methodology/approach

In this paper, two types of inductorless Chua’s circuit models are presented from topological structure, among which the first type of inductorless Chua’s circuit (FTICC) model is much closer to the original Chua’s circuit. Under this classification framework, a new inductorless Chua’s circuit that belongs to the FTICC model is built by replacing LC parallel resonance of the original Chua’s circuit with a second order Sallen–Key band pass filter.

Findings

Compared with a paradigm of a reported inductorless Chua’s circuit that belongs to the second type of inductorless Chua’s circuit (STICC) model, the newly proposed circuit can present the attractors which are much more closely to the original Chua’s attractors. The dynamical behaviors of coexisting period-doubling bifurcation patterns and boundary crisis are discovered in the newly proposed circuit from both numerical simulations and experimental measurements. Moreover, a crisis scenario is observed that unmixed pairs of symmetric coexisting limit cycles with period-3 traverse through the entire parameter interval between coexisting single-scroll chaotic attractors and double-scroll chaotic attractor.

Originality/value

The newly constructed circuit enriches the family of inductorless Chua’s circuits, and its simple topology with small printed circuit board size facilitates the various types of engineering applications based on chaos.

Article
Publication date: 11 May 2020

Mengjie Hua, Shuo Yang, Quan Xu, Mo Chen, Huagan Wu and Bocheng Bao

The purpose of this paper is to develop two types of simple jerk circuits and to carry out their dynamical analyses using a unified mathematical model.

Abstract

Purpose

The purpose of this paper is to develop two types of simple jerk circuits and to carry out their dynamical analyses using a unified mathematical model.

Design/methodology/approach

Two types of simple jerk circuits only involve a nonlinear resistive feedback channel composited by a nonlinear device and an inverter. The nonlinear device is implemented through parallelly connecting two diode-switch-based series branches. According to the classifications of switch states and circuit types, a unified mathematical model is established for these two types of simple jerk circuits, and the origin symmetry and scale proportionality along with the origin equilibrium stability are thereby discussed. The coexisting bifurcation behaviors in the two types of simple jerk systems are revealed by bifurcation plots, and the origin symmetry and scale proportionality are effectively demonstrated by phase plots and attraction basins. Moreover, hardware experimental measurements are performed, from which the captured results well validate the numerical simulations.

Findings

Two types of simple jerk circuits are unified through parallelly connecting two diode-switch-based series branches and a unified mathematical model with six kinds of nonlinearities is established. Especially, the origin symmetry and scale proportionality for the two types of simple jerk systems are discussed quantitatively. These jerk circuits are all simple and inexpensive, easy to be physically implemented, which are helpful to explore chaos-based engineering applications.

Originality/value

Unlike previous works, the significant values are that through unifying these two types of simple jerk systems, a unified mathematical model with six kinds of nonlinearities is established, upon which symmetrically scaled coexisting behaviors are numerically disclosed and experimentally demonstrated.

Details

Circuit World, vol. 47 no. 1
Type: Research Article
ISSN: 0305-6120

Keywords

Article
Publication date: 23 August 2021

Chun-Mei Kai, Feng-Jun Zhang, Cong-Liang Cheng and Qian-Bao Chen

The purpose of this paper is to study the influence of different factors on mud performance, find the best conditions and synthesize a new type of anti-collapse drilling polymer…

Abstract

Purpose

The purpose of this paper is to study the influence of different factors on mud performance, find the best conditions and synthesize a new type of anti-collapse drilling polymer mud with higher stability. The anti-collapse mechanism of drilling polymer mud was also suggested.

Design/methodology/approach

Exploring the influence of different molecular weight thickeners, filtrate reducers, soda ash addition and film-forming components on the mud performance, so as to obtain the best ratio of anti-collapse drilling polymer mud.

Findings

The results show that the use of vegetable glue, sulfonate copolymer and vegetable fiber powder can synthesize a high-viscosity, high-stability, collapse-resistant mud. When the mass ratio of vegetable fiber powder: vegetable glue: sulfonate copolymer is 40:1:2, the mud viscosity is 21.2 s, the fluid loss in 30 min is only 12.5 mL, and the mud film thickness is 1.5 mm, which is one ideal anti-collapse polymer mud.

Originality/value

Compared with ordinary polymer mud and bentonite mud, this anti-collapse polymer mud not only uses vegetable glue instead of traditional tackifiers but also effectively uses vegetable fiber powder produced from waste wood, which is environmentally friendly and highly stable specialty. It can effectively improve the safety and quality of construction during drilling in water-sensitive geology.

Details

Pigment & Resin Technology, vol. 51 no. 1
Type: Research Article
ISSN: 0369-9420

Keywords

Article
Publication date: 21 July 2020

Dong Zhu, Liping Hou, Mo Chen and Bocheng Bao

The purpose of this paper is to develop an field programmable gate array (FPGA)-based neuron circuit to mimic dynamical behaviors of tabu learning neuron model.

Abstract

Purpose

The purpose of this paper is to develop an field programmable gate array (FPGA)-based neuron circuit to mimic dynamical behaviors of tabu learning neuron model.

Design/methodology/approach

Numerical investigations for the tabu learning neuron model show the coexisting behaviors of bi-stability. To reproduce the numerical results by hardware experiments, a digitally FPGA-based neuron circuit is constructed by pure floating-point operations to guarantee high computational accuracy. Based on the common floating-point operators provided by Xilinx Vivado software, the specific functions used in the neuron model are designed in hardware description language programs. Thus, by using the fourth-order Runge-Kutta algorithm and loading the specific functions orderly, the tabu learning neuron model is implemented on the Xilinx FPGA board.

Findings

With the variation of the activation gradient, the initial-related coexisting attractors with bi-stability are found in the tabu learning neuron model, which are experimentally demonstrated by a digitally FPGA-based neuron circuit.

Originality/value

Without any piecewise linear approximations, a digitally FPGA-based neuron circuit is implemented using pure floating-point operations, from which the initial conditions-related coexisting behaviors are experimentally demonstrated in the tabu learning neuron model.

Details

Circuit World, vol. 47 no. 2
Type: Research Article
ISSN: 0305-6120

Keywords

Article
Publication date: 15 February 2021

Chen Bao, Yongwei Miao, Bingfei Gu, Kaixuan Liu and Zhen Liu

The purpose of this paper is to propose an interactive 2D–3D garment parametric pattern-making and linkage editing scheme that integrates clothing design, simulation and…

Abstract

Purpose

The purpose of this paper is to propose an interactive 2D–3D garment parametric pattern-making and linkage editing scheme that integrates clothing design, simulation and interaction to design 3D garments and 2D patterns. The proposed scheme has the potential to satisfy the individual needs of fashion industry, such as precise fit evaluation of the garment, interactive style editing with ease allowance and constrained contour lines in fashion design.

Design/methodology/approach

The authors first construct a parametric pattern-making model for flat pattern design corresponding to the body dimensions. Then, the designing 2D patterns are stitched on a virtual 3D mannequin by performing a virtual try-on. If the customer is unsatisfied after the virtual try-on, the adjustable parameters (appearance parameters and fit parameters) can be adjusted using the 2D–3D linkage editing with hierarchical constrained contour lines, and the fit evaluation tool interactively provides the feedback.

Findings

The authors observed that the usability and efficiency of the existing garment pattern-making method simplifies the garment pattern-making process. The authors utilize an interactive garment parametric flat pattern-making model to generate an individualized garment flat pattern that effectively adjust and realize the local editing of the garment pattern-making. The 2D–3D linkage editing is then employed, which alters the size and shape of garment pattern for a precise human model fit of the 3D garment using hierarchical constrained contour lines. Various instances have validated the effectiveness of the proposed scheme, which can increase the reusability of the existing garment styles and improve the efficiency of fashion design.

Research limitations/implications

First, the authors do not consider the garment pattern-making design of sophisticated styles. Second, the authors do not directly consider complex garment shapes such as wrinkles, folds, multi-layer models and fabric physical properties.

Originality/value

The authors propose a pattern adjustment scheme that uses the 3D virtual try-on technology to avoid repetitions of reality-based fit tests and garment sample making in the designing process of clothing products. The proposed scheme provides interactive selections of garment patterns and sizes and renders modification tools for 3D garment designing and 2D garment pattern-making. The authors present the 2D–3D interactive linkage editing scheme for a custom-fit garment pattern based on the hierarchical constraint contour lines. The spatial relationship among the human body, pattern pieces and 3D garment model is adequately expressed, and the final design result of the garment pattern is obtained by constraint solving. Meanwhile, the tightness tension of different parts of the 3D garment is analyzed, and the fit and comfort of the garment are quantitatively evaluated.

Details

International Journal of Clothing Science and Technology, vol. 33 no. 5
Type: Research Article
ISSN: 0955-6222

Keywords

Book part
Publication date: 7 December 2016

Abstract

Details

The World Meets Asian Tourists
Type: Book
ISBN: 978-1-78560-219-1

Book part
Publication date: 19 April 2017

Laura Alfaro

Among the prominent economic trends in recent decades is the exponential increase in flows of goods and capital driven by technological progress and falling of restrictions. A key…

Abstract

Among the prominent economic trends in recent decades is the exponential increase in flows of goods and capital driven by technological progress and falling of restrictions. A key driver of this phenomenon has been the cross-border production, foreign investment, and trade both final and intermediate goods by multinational corporations. Research has sought to understand how foreign direct investment (FDI) affects host economies. This paper reviews the main theories and empirical evidence of two streams of literature: the mechanisms by which multinational activity might create positive effects and externalities to countries and the role of complementary local conditions, also known as “absorptive capacities,” that allow a country to reap the benefits of FDI paying particular attention to the role of factor markets, reallocation effects, and the linkages generated between foreign and domestic firms. The survey focuses mainly on work related to developing countries.

Details

Geography, Location, and Strategy
Type: Book
ISBN: 978-1-78714-276-3

Keywords

Article
Publication date: 2 February 2015

Krystyna K. Matusiak, Ling Meng, Ewa Barczyk and Chia-Jung Shih

The purpose of this paper is to explore multilingual access in digital libraries and to present a case study of creating bilingual metadata records for the Tse-Tsung Chow…

1331

Abstract

Purpose

The purpose of this paper is to explore multilingual access in digital libraries and to present a case study of creating bilingual metadata records for the Tse-Tsung Chow Collection of Chinese Scrolls and Fan Paintings. The project, undertaken at the University of Wisconsin-Milwaukee Libraries, provides access to digital copies of calligraphic and painted Chinese scrolls and fans from the collection donated by Prof Tse-Tsung Chow (Cezong Zhou).

Design/methodology/approach

This paper examines the current approaches to multilingual indexing and retrieval in digital collections and presents a model of creating bilingual parallel records that combines translation with controlled vocabulary mapping.

Findings

Creating multilingual metadata records for cultural heritage materials is in an early phase of development. Bilingual metadata created through human translation and controlled vocabulary mapping represents one of the approaches to multilingual access in digital libraries. Multilingual indexing of collections of international origin addresses the linguistic needs of the target audience, connects the digitized objects to their respective cultures and contributes to richer descriptive records. The approach that relies on human translation and research can be undertaken in small-scale digitization projects of rare cultural heritage materials. Language and subject expertise are required to create bilingual metadata records.

Research limitations/implications

This paper presents the results of a case study. The approach to multilingual access that involves research, and it relies on human translation that can only be undertaken in small-scale projects.

Practical implications

This case study of creating parallel records with a combination of translation and vocabulary mapping can be useful for designing similar bilingual digital collections.

Social implications

This paper also discusses the obligations of holding institutions in undertaking digital conversion of the cultural heritage materials that originated in other countries, especially in regard to providing metadata records that reflect the language of the originating community.

Originality/value

The research and practice in multilingual indexing of cultural heritage materials are very limited. There are no standardized models of how to approach building multilingual digital collections. This case study presents a model of providing bilingual access and enhancing the intellectual control of cultural heritage collections.

Details

The Electronic Library, vol. 33 no. 1
Type: Research Article
ISSN: 0264-0473

Keywords

Book part
Publication date: 14 September 2023

Jason Hung

In Chapter 2, the author will develop the theoretical framework of the sociological analysis of youth delinquency in SEA. The author will introduce the control theory (both…

Abstract

In Chapter 2, the author will develop the theoretical framework of the sociological analysis of youth delinquency in SEA. The author will introduce the control theory (both self-control and social control), in order to understand under what circumstances youths are more and less likely to behave in a deviant manner. The author will, then, mention the general strain theory, to draw the relationships between the encounters of negative life events, the development of strain, and the disposition to perform delinquency. The author will also, address the cultural deviance and social learning theories that help justify the expression of juvenile delinquency from a sociocultural perspective, alongside pathing the way to explaining how social costs of youth delinquency can be raised by policy amendments in order to mitigate adolescents’ exercises of smoking, drinking and sexual misconduct behaviours. In this chapter, the author will highlight how poverty, the availability of delinquent opportunities, peer influence and pressure, a lack of parental and school socialisation, and deviant social and cultural norms are all risk factors for youth delinquency.

Details

The Socially Constructed and Reproduced Youth Delinquency in Southeast Asia: Advancing Positive Youth Involvement in Sustainable Futures
Type: Book
ISBN: 978-1-83753-886-7

Keywords

Article
Publication date: 10 November 2022

Xinxing Yin, Juan Chen, Wenxin Yu, Yuan Huang, Wenxiang Wei, Xinjie Xiang and Hao Yan

This study aims to improve the complexity of chaotic systems and the security accuracy of information encrypted transmission. Applying five-dimensional memristive Hopfield neural…

Abstract

Purpose

This study aims to improve the complexity of chaotic systems and the security accuracy of information encrypted transmission. Applying five-dimensional memristive Hopfield neural network (5D-HNN) to secure communication will greatly improve the confidentiality of signal transmission and greatly enhance the anticracking ability of the system.

Design/methodology/approach

Chaos masking: Chaos masking is the process of superimposing a message signal directly into a chaotic signal and masking the signal using the randomness of the chaotic output. Synchronous coupling: The coupled synchronization method first replicates the drive system to get the response system, and then adds the appropriate coupling term between the drive The synchronization error and the coupling term of the system will eventually converge to zero with time. The synchronization error and coupling term of the system will eventually converge to zero over time.

Findings

A 5D memristive neural network is obtained based on the original four-dimensional memristive neural network through the feedback control method. The system has five equations and contains infinite balance points. Compared with other systems, the 5D-HNN has rich dynamic behaviors, and the most unique feature is that it has multistable characteristics. First, its dissipation property, equilibrium point stability, bifurcation graph and Lyapunov exponent spectrum are analyzed to verify its chaotic state, and the system characteristics are more complex. Different dynamic characteristics can be obtained by adjusting the parameter k.

Originality/value

A new 5D memristive HNN is proposed and used in the secure communication

Details

Circuit World, vol. 50 no. 1
Type: Research Article
ISSN: 0305-6120

Keywords

1 – 10 of over 2000