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Article
Publication date: 15 January 2020

Wei Yanhong, Xinjin Liu, Xuzhong Su and Zhao Zhimin

In order to develop high shape retention yarn and investigate the effects of spinning process and core yarn contents on the shape retention of yarn, in this paper, three kinds of…

155

Abstract

Purpose

In order to develop high shape retention yarn and investigate the effects of spinning process and core yarn contents on the shape retention of yarn, in this paper, three kinds of yarns, JC/T400 18.5tex (55.6dtex) core-spun yarn, JC/T400 18.5tex (44.4dtex) core-spun yarn and JC18.5tex pure cotton yarn were spun by using the complete condensing Siro-spinning technology. The paper aims to discuss these issues.

Design/methodology/approach

In this paper, the core-spun yarns were spun by using the complete condensing spinning and Siro-spinning technology. Two key spinning processes, yarn twist factor and core yarn pre-draft ratio, were optimized by using the orthogonal test method first. Then, via the variable control method, the position of the core yarn, the position of the bell mouth and the center distance between two bell mouths were optimized, respectively, and corresponding optimal spinning process of the three yarns was determined. Finally, the yarns were spun under the optimal process, and the performance of the spun yarns was tested and compared.

Findings

Results show that the yarn twist factor affects yarn strength and hairiness, the position of bell mouth affects the evenness and hairiness of the yarn mainly, and the position of the core yarn affects the coverage and hairiness of the yarn. For the Z-twist spinning, the core yarn enters the front roller from the left side of two strands center, which is beneficial to improve the covering effect of core yarn, and reduce the pilling phenomenon of the yarn. The contents of core yarn affect indicators of the yarn shape retention, such as yarn strength, elastic recovery and abrasion resistance.

Originality/value

The shape retention of yarns affects the shape retention of fabrics, and the production of yarn with high shape retention is a key step in achieving shape retention of fabrics. At present, there are little studies on the shape retention of yarns, most researchers shave focused on shape retention of fabrics. Using the complete condensing Siro-spinning method to spin the core-spun yarn can improve the quality of the yarn. Compared with traditional ring-spinning yarns, the addition of the core yarn can improve the shape retention of the yarn.

Details

International Journal of Clothing Science and Technology, vol. 32 no. 4
Type: Research Article
ISSN: 0955-6222

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Article
Publication date: 8 March 2011

Xiaolei Yu and Zhimin Zhao

The purpose of this paper is to present a novel method for integrating of chaotic exploration and thinning‐based topological mapping to deal with the “traverse targets and return”…

934

Abstract

Purpose

The purpose of this paper is to present a novel method for integrating of chaotic exploration and thinning‐based topological mapping to deal with the “traverse targets and return” problem applied for robot navigation in unknown environments. This new strategy can guarantee the robot stronger ability of exploring unknown environments, as well as recording and selecting optimal trajectory to return.

Design/methodology/approach

The chaotic dynamic evolution of controlled multi‐scroll system is linked to the multi‐sensory perception and reactive behaviors of a mobile robot. The thinning‐based topological map (TTM), as the contextual layer of the cognitive system, is adopted to achieve the environmental recording in the process of robot exploration and navigation. Once the robot arrives at the terminal target via avoiding all the obstacles, the TTM has been built in real time. Based on the records in the topological map, a short and smooth point‐to‐point path is generated to achieve the exit from target and to move back to the starting point.

Findings

The simulation results confirmed that the proposed solution is suitable to resolve the robot's tasks of obstacle avoidance, target retrieving, and return, also has better performance than traditional strategies.

Originality/value

The presented novel method focuses integration of chaotic exploration and TTM self‐construction. The chaotic perception and control technique permits the robot to explore most of the environmental information within the smallest explored area. The introduced topological map, generated by applying a thinning algorithm, guarantees a short and smooth returning trajectory for the robot.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 30 no. 2
Type: Research Article
ISSN: 0332-1649

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Article
Publication date: 31 January 2024

Dangshu Wang, Menghu Chang, Licong Zhao, Yuxuan Yang and Zhimin Guan

This study aims to regarding the application of traditional pulse frequency modulation control full-bridge LLC resonant converters in wide output voltage fields such as on-board…

79

Abstract

Purpose

This study aims to regarding the application of traditional pulse frequency modulation control full-bridge LLC resonant converters in wide output voltage fields such as on-board chargers, there are issues with wide frequency adjustment ranges and low conversion efficiency.

Design/methodology/approach

To address these issues, this paper proposes a fixed-frequency pulse width modulation (PWM) control strategy for a full-bridge LLC resonant converter, which adjusts the gain by adjusting the duty cycle of the switches. In the full-bridge LLC converter, the two switches of the lower bridge arm are controlled by a fixed-frequency and fixed duty cycle, with their switching frequency equal to the resonant frequency, whereas the two switches of the upper bridge arm are controlled by a fixed-frequency PWM to adjust the output voltage. The operation modes of the converter are analyzed in detail, and a mathematical model of the converter is established. The gain characteristics of the converter under the fixed-frequency PWM control strategy are deeply analyzed, and the conditions for implementing zero-voltage switching (ZVS) soft switching in the converter are also analyzed in detail. The use of fixed-frequency PWM control simplifies the design of resonant parameters, and the fixed-frequency control is conducive to the design of magnetic components.

Findings

According to the fixed-frequency PWM control strategy proposed in this paper, the correctness of the control strategy is verified through simulation and the development and testing of a 500-W experimental prototype. Test results show that the primary side switches of the converter achieve ZVS and the secondary side rectifier diodes achieve zero-current switching, effectively reducing the switching losses of the converter. In addition, the control strategy reduces the reactive circulating current of the converter, and the peak efficiency of the experimental prototype can reach 95.2%.

Originality/value

The feasibility of the fixed-frequency PWM control strategy was verified through experiments, which has significant implications for improving the efficiency of the converter and simplifying the design of resonant parameters and magnetic components in wide output voltage fields such as on-board chargers.

Details

Circuit World, vol. 50 no. 2/3
Type: Research Article
ISSN: 0305-6120

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Article
Publication date: 16 December 2024

Zhimin Liang, Xinyu Zhao, Yunjia Li, Yuzhong Rao, Kehong Wang and Xiaobing Wang

Adding Pd element to Au wire can improve the reliability of Au-Al bonding, but the mechanism of Pd element has not been well revealed so far. The purpose of this study is to…

8

Abstract

Purpose

Adding Pd element to Au wire can improve the reliability of Au-Al bonding, but the mechanism of Pd element has not been well revealed so far. The purpose of this study is to reveal in more detail the mechanism of the role of Pd elements in Au/Al bonding.

Design/methodology/approach

In this paper, the microstructure changes and tensile data of 99.99% (4N) gold wire and 99% (2N) gold wire with 1 at % Pd were compared through high-temperature thermal aging treatment of the specimens, so as to explore the influence mechanism of Pd element on Au-Al bonding reliability.

Findings

The addition of Pd element effectively reduces the thickness of intermetallic compounds (IMCs) layer and strengthens the fracture tension and reliability. Compared with the 4N specimen, the average thickness of the IMCs layer of the 2N specimen under the same conditions is reduced by 1 µm, and the tensile value of the 2N specimen is increased by 1−3 g. Stored at 200°C for 200 h, the failure rate of bond point of 4N specimen reached 94.64%, and that of 2N specimen was 20%, with a difference of 4.73 times.

Originality/value

Through comparative analysis of the data, this study found that the doping of Pd element in Au-Al IMCs in the early stage slowed down the growth rate of the IMCs, and the precipitation of Pd element in the late stage to form a better Pd-rich layer hindered the element mutual diffusion behavior between Au and Al.

Details

Soldering & Surface Mount Technology, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 0954-0911

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Article
Publication date: 15 May 2024

Dangshu Wang, Zhimin Guan, Jing Wang, Menghu Chang, Licong Zhao and Xinxia Wang

This study aims to solve the problem of high output voltage fluctuation and low efficiency caused by the misalignment of the magnetic coupling structure in the wireless charging…

75

Abstract

Purpose

This study aims to solve the problem of high output voltage fluctuation and low efficiency caused by the misalignment of the magnetic coupling structure in the wireless charging system for electric vehicles. To address these issues, this paper proposes a dual LCC-S wireless power transfer (WPT) system based on the double-D double-layer quadrature (DDDQ) coil, which can realize the anti-misalignment constant voltage output of the system.

Design/methodology/approach

First, this paper establishes the equivalent circuit of a WPT system based on dual LCC-S compensation topology and analyzes its constant-voltage output characteristics and the relationship between system transmission efficiency and coupling coefficient. 1. Quadruple D (Ahmad et al., 2019) and double-D quadrature pad (DDQP) (Chen et al., 2019) coils have good anti-misalignment in the transverse and longitudinal directions, but the magnetic induction intensity in the center of the coils is weak, making it difficult for the receiving coil to effectively couple to the magnetic field energy. 2. Based on the double-D quadrature (DDQ) structure coil that can eliminate the mutual inductance between coupling coils and cross-coupling, Gong et al. (2022a) proposed a parameter optimized LCC-LC series-parallel hybrid topology circuit, which ensures that the output current fluctuation is controlled within 5% only when the system is misaligned within the 50% range along the X direction, achieving constant current output with anti-misalignment. The magnetic coupling structure’s finite element simulation model is established to analyze the change in magnetic induction intensity and the system’s anti-misalignment characteristics when the coil offsets along the x and y axes. Finally, an experimental prototype is developed to verify the constant voltage output performance and anti-misalignment performance of the system, and the proposed anti-misalignment system is compared with the systems in existing literature, highlighting the advantages of this design.

Findings

The experimental results show that the system can achieve a constant voltage output of 48V under a time-varying load, and the output voltage fluctuates within ±5% of the set value within the range of ±60 mm lateral misalignment and ±72 mm longitudinal misalignment.

Originality/value

Based on the dual LCC-S WPT system, the mutual inductance between the same side coils is reduced by adding decoupling coils, and the anti-misalignment characteristics and output power of the system are improved in a certain range. It is aimed at improving the stability of the system output and transmission efficiency.

Details

Circuit World, vol. 50 no. 2/3
Type: Research Article
ISSN: 0305-6120

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Article
Publication date: 12 July 2021

Tao Lan, Xiaodong Feng and Zhimin Zeng

This study aims to focus on understanding how the characteristics of the bed and breakfast (B&B) host responses to online reviews impact the subsequent business performance of…

491

Abstract

Purpose

This study aims to focus on understanding how the characteristics of the bed and breakfast (B&B) host responses to online reviews impact the subsequent business performance of review volume, including volume, timeliness and length of responses.

Design/methodology/approach

The study constructs a theoretical framework to model for the relationships among characteristics of the B&B host responses, heterogeneity of B&B houses and subsequent reviews. The model is then examined by an econometric model using data from Ctrip.com.

Findings

Prompt and lengthy responses to online reviews increase the number of subsequent reviews, and the effects are larger for higher level houses. The main theoretical contribution is to build a model explaining how multiple attributes of the host responses can affect business performance and how these effects are moderated by the class levels of B&B houses, which are empirically tested by real data.

Practical implications

This study highlights managerial implications of host responses for online B&B business practices. For the higher-quality B&B houses, based on price and reviews, lengthy and timely responses are necessary, as tourists expect increased customer service from these hosts.

Originality/value

The research provides insights in understanding the mechanism of B&B host responses on subsequent reviews. To the best of the authors’ knowledge, this is the first study to demonstrate the moderating effect of price and volume of online reviews on responses.

共享民宿房主对在线评论的反应如何影响后续评论:房屋等级的调节效应

摘要 -- 目的

本研究旨着重探讨民宿房主对网上评论的回应特性如何影响评论量的后续经营绩效, 包括回复数量、及时性和回复的长度。

方法 -- 本研究首先构建理论框架, 对民宿房主的在线回应特征、民宿房屋的异质性特征与后续评论之间的关系进行建模。该模型通过一个计量经济学模型对从携程网收集的数据进行了检验.

研究结果 -- 本研究的结果显示, 对在线旅游评论提供及时和冗长的回复, 可能会增加未来的预订数量, 从而增加后续的评论,并且这个影响随着房屋等级的提高而增加。本文的主要理论贡献是建立一个模型来解释房屋主人在线回应的多重属性如何影响他们的经营绩效, 以及这些影响是如何被房屋等级所调节的,并通过真实数据对理论进行了验证。

研究意义 -- 该研究有助于将研究重点从在线评论和口碑转移到管理层的回应效应。我们的研究结果印证了之前的研究关于评论量可以影响口碑信息说服力及其他口碑相关特征(如管理层回应)影响的结论。

管理启示 -- 本研究的结果, 向民宿房主提供了具体的管理启示, 为网上民宿商业管理提供参考。对于价格更高、在线声誉较高的B&B房屋, 应提供更多及时的回应, 因为游客期望得到更友好的客户服务。

原创性 -- 这项研究提供了关于民宿房主在线回应对后续评论量影响机制的探索。并将是首次尝试验证价格和在线评论量对在线回复影响的调节作用。

Entendiendo cómo las respuestas de los dueños de establecimientos de B&B a las opiniones de los turistas en línea promoverán las opiniones subsiguientes: Los efectos moderadores del nivel de clase de los establecimientos de B&B

Resumen

Propósito -- Este estudio se centra en comprender cómo las características de las respuestas de los anfitriones de alojamientos B&B influyen en el rendimiento empresarial de volumen de reseñas; esto incluye el número de respuestas, la puntualidad de la respuesta y la duración de la misma.

Metodología -- En primer lugar, el estudio construye un marco teórico para establecer un modelo de relación entre las características de las respuestas de los anfitriones de alojamientos, heterogéneos de alojamientos B&B y las revisiones posteriores. A continuación, el modelo es examinado por un modelo econométrico a partir de los datos recogidos en ctrip.com.

Resultados -- Se ha demostrado que las respuestas rápidas y extensas a las reseñas en línea pueden aumentar potencialmente el número de reseñas posteriores, y tuvieron un mayor impacto en las viviendas de gran altura. La principal contribución teórica de este trabajo es construir un modelo para explicar cómo los múltiples factores de la respuesta de los anfitriones pueden afectar a su rendimiento empresarial y cómo estos efectos son moderados por las nivel de los alojamientos B&B, través de los datos reales de la prueba empírica.

Implicaciones prácticas -- Proporciona una referencia para la práctica empresarial de los alojamientos B&B en línea, al informar sobre las implicaciones específicas de gestión para los anfitriones de alojamientos B&B. En el caso de las casas de alojamientos B&B de mayor nivel, con precios más altos y más reseñas en línea, se deberían dar más respuestas oportunas, ya que los turistas esperan de los anfitriones un servicio de atención al cliente más amable.

Originalidad -- La investigación permite comprender el mecanismo de las respuestas de los anfitriones de alojamientos B&B en las reseñas posteriores. Sería el primer intento de demostrar el efecto moderador del precio y el volumen de las reseñas en línea sobre el impacto de las respuestas.

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Article
Publication date: 7 December 2021

Zhimin Zhou, Rixiang Wang and Ge Zhan

This study aims to investigate the role of multidimensional social capital and consumer subjective well-being in online brand communities (OBCs). The aim was to provide practical…

1250

Abstract

Purpose

This study aims to investigate the role of multidimensional social capital and consumer subjective well-being in online brand communities (OBCs). The aim was to provide practical guidance to global brand marketers for cultivating and strengthening OBC operations, optimizing consumer-brand-community relationships and creating value in the digital age.

Design/methodology/approach

A total of 576 valid questionnaires were collected through an online survey, and the model was tested using partial least squares structural equation modeling.

Findings

In OBCs, the cognitive dimension of social capital (i.e. shared language and shared vision) strongly affects the relational dimension of social capital (i.e. social trust and reciprocity). Both these dimensions also positively influence consumer community subjective well-being, which, in turn, enhances consumer brand subjective well-being. Thus, community subjective well-being has a mediating role in the aforementioned relationship, and brand community is an antecedent to brand subjective well-being.

Research limitations/implications

Future studies should investigate other dimensions of social capital and well-being, as well as moderator variables, social environments and types of culture.

Originality/value

This study constructed a conceptual framework that focused on the effect of multidimensional social capital in OBCs to elucidate antecedents of brand subjective well-being from the perspectives of social networks and relationships. Moreover, it examined how brands strategically expand their clientele base with regard to target customers.

Details

Journal of Product & Brand Management, vol. 31 no. 5
Type: Research Article
ISSN: 1061-0421

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Article
Publication date: 31 August 2021

Kexin Zhang, Tianyu Qi, Dachao Li, Xingwei Xue and Zhimin Zhu

The paper aims to investigate effectiveness of the strengthening method, the construction process monitoring, fielding-load tests before and after strengthening, and health…

143

Abstract

Purpose

The paper aims to investigate effectiveness of the strengthening method, the construction process monitoring, fielding-load tests before and after strengthening, and health monitoring after reinforcement were carried out. The results of concrete strain and deflection show that the flexural strength and stiffness of the strengthened beam are improved.

Design/methodology/approach

This paper describes prestressed steel strand as a way to strengthen a 25-year-old continuous rigid frame bridge. High strength, low relaxation steel strand with high tensile strain and good corrosion resistance were used in this reinforcement. The construction process for strengthening with prestressed steel strand and steel plate was described. Ultimate bearing capacity of the bridge after strengthening was discussed based on finite element model.

Findings

The cumulative upward deflection of the second span the third span was 39.7 mm, which is basically consistent with the theoretical value, and the measured value is smaller than the theoretical value. The deflection value of the second span during data acquisition was −20 mm–10 mm, which does not exceed the maximum deflection value of live load, and the deflection of the bridge is in a safe state during normal use. Thus, this strengthened way with prestressed steel wire rope is feasible and effective.

Originality/value

This paper describes prestressed steel strand as a way to strengthen a 25-year-old continuous rigid frame bridge. To investigate effectiveness of the strengthening method, the construction process monitoring, fielding-load tests before and after strengthening and health monitoring after reinforcement were carried out.

Details

International Journal of Structural Integrity, vol. 12 no. 6
Type: Research Article
ISSN: 1757-9864

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Article
Publication date: 18 November 2020

Jialing (Catherine) Lin, Zhimin Zhou and Civilai Leckie

This study aims to empirically investigate how green transparency and green competence enhancement can promote consumer behavioral outcomes (i.e. green brand loyalty and…

3032

Abstract

Purpose

This study aims to empirically investigate how green transparency and green competence enhancement can promote consumer behavioral outcomes (i.e. green brand loyalty and resistance to negative information regarding green brands) through green brand attachment (i.e., self–green brand connection and green brand prominence). It further explores these hypothesized relationships across brands of physical products and services.

Design/methodology/approach

Data were collected using an online survey from 826 Chinese consumers. Structural equation modeling is used to test the proposed conceptual model.

Findings

Our results demonstrate that green transparency and green competence enhancement positively affect consumer green brand attachment (i.e. self–green brand connection and green brand prominence) which subsequently influence consumers’ loyalty toward green brands and their resistance to negative information. Finally, the development of green brand attachment across brands of products and services is found to be different.

Research limitations/implications

Extending the conceptual model to other cultural contexts is suggested. Using the experimental design to examine other boundary conditions is recommended.

Practical implications

This study provides recommendations for marketers, especially brand managers, to facilitate green brand communications to strengthen consumer–brand relationships.

Originality/value

This study extends past research by examining two types of green brand attachment via a cognitive schema lens. Also, it shows the internal cognitive process by which green brand communications potentially promote consumer behavioral outcomes through green brand attachment. Lastly, it highlights differences in the development of green brand loyalty and consumer resistance to negative information across brands of products and services.

Details

Journal of Product & Brand Management, vol. 30 no. 8
Type: Research Article
ISSN: 1061-0421

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Publication date: 1 March 2007

Wilson Wong

Although the Chinese economy has experienced a strong and rapid growth due to the success of its economic reform, the Chinese central government faces a stern fiscal decline. The…

96

Abstract

Although the Chinese economy has experienced a strong and rapid growth due to the success of its economic reform, the Chinese central government faces a stern fiscal decline. The fiscal problem has undermined the ability of the central government in completing many crucial governing tasks. By examining the institutional root of the fiscal problem, this paper argues that the fiscal decline is part of the ironic corollary of the decentralization strategy of China’s economic reform which produces a “weak center, strong local” outcome. To fully address the problem, China should undertake major institutional reforms to redefine as well as institutionalize the fiscal roles of different levels of government.

Details

Journal of Public Budgeting, Accounting & Financial Management, vol. 19 no. 1
Type: Research Article
ISSN: 1096-3367

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