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Article
Publication date: 1 September 2006

Qinglei Hu

To provide an approach to active vibration reduction of flexible spacecraft actuated by on‐off thrusters during attitude control for spacecraft designers, which can help them…

625

Abstract

Purpose

To provide an approach to active vibration reduction of flexible spacecraft actuated by on‐off thrusters during attitude control for spacecraft designers, which can help them analysis and design the attitude control system.

Design/methodology/approach

The new approach includes attitude controller acting on the rigid hub, designed by using pulse‐width pulse‐frequency modulation integrated with component command technique, and the piezoelectric material elements as sensors/actuators bonded on the surface of the beam appendages for active vibration suppression of flexible appendages, designed by optimal positive position feedback (OPPF) control technique. The OPPF compensator is devised by setting up a cost function to be minimized by feedback gains, which are subject to the stability criterion at the same time, and an extension to the conventional positive position feedback control design approach is investigated.

Findings

Numerical simulations for the flexible spacecraft show that the precise attitude control and vibration suppression can be accomplished using the derived vibration attenuator and attitude control controller.

Research limitations/implications

Studies on how to control the on‐off actuated system under impulse disturbances are left for future work.

Practical implications

An effective method is proposed for the spacecraft engineers planning to design attitude control system for actively suppressing the vibration and at the same time quickly and precisely responding to the attitude control command.

Originality/value

The advantage in this scheme is that the controllers are designed separately, allowing the two objectives to be satisfied independently of one another. It fulfils a useful source of theoretical analysis for the attitude control system design and offers practical help for the spacecraft designers.

Details

Aircraft Engineering and Aerospace Technology, vol. 78 no. 5
Type: Research Article
ISSN: 0002-2667

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Article
Publication date: 12 July 2013

Cun‐Cen Li, Ming Yang, Ya‐Fei Pang and Shi‐Yang Li

The purpose of this paper is to propose an optimization method by combining artificial immune algorithm and finite element analysis to find the optimal exciting electrode of a…

389

Abstract

Purpose

The purpose of this paper is to propose an optimization method by combining artificial immune algorithm and finite element analysis to find the optimal exciting electrode of a piezoceramic plate type ultrasonic motor vibrator.

Design/methodology/approach

The artificial immune algorithm is selected as optimizer for its merit of fast convergence to global optimal solution. The finite element analysis is used to calculate the motion trajectory of contact point. The objective function is the work that the vibrator does to rotor. The design variables are the boundaries of exciting electrode on piezoceramic plate vibrator surface.

Findings

The calculated results and the experimental results show that using this method, both the position and the size of optimal exciting electrode of this ultrasonic motor can be quickly and accurately determined.

Originality/value

In order to successfully design an ultrasonic motor, both the position and the size of the exciting electrode must be investigated, so as to change more electric energy into mechanical energy. In this paper, an optimization method by combining artificial immune algorithm and finite element analysis is proposed for the exciting location optimization of a piezoceramic plate type ultrasonic motor to obtain large power output.

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Article
Publication date: 29 July 2014

Jun-Shan Li, Pei-Pei He and Rui-Bo He

The purpose of this paper is to provide theoretical model about supplier-induced demand (SID) in health care market in China. Then, an empirical analysis will also be carried out…

442

Abstract

Purpose

The purpose of this paper is to provide theoretical model about supplier-induced demand (SID) in health care market in China. Then, an empirical analysis will also be carried out according to the theoretical model above. At last, some advices will be provided in order to control or eliminate the SID in Chinese health care market.

Design/methodology/approach

SID has in fact been one of the most contentious topics in the economics of health care. According to the SID theory in health economics, the theoretical model about SID in China has been provided, then, based on the co-integration theory, the empirical analysis has been brought out.

Findings

The study tells that it is the reduction of government finance to hospital, not the increase of supply that is the long-term steady determinants of growth of health care expenditure and that the difference of marginal return to hospital among all kinds of services and medicines is the external factor.

Originality/value

To provide theoretical model about SID in health care market in China is the main originality value.

Details

Grey Systems: Theory and Application, vol. 4 no. 2
Type: Research Article
ISSN: 2043-9377

Keywords

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Article
Publication date: 31 May 2013

Jin Zhang, Jun Shan and Susheng Wang

Inspired by the recent opening up of the Chinese banking market and by the ensuing location strategies adopted by foreign banks, the purpose of this paper is to develop an…

469

Abstract

Purpose

Inspired by the recent opening up of the Chinese banking market and by the ensuing location strategies adopted by foreign banks, the purpose of this paper is to develop an empirical analysis on location strategies. The paper enriches the existing literature by including many important realistic aspects, some of which have never been analyzed in theory before, especially for firms entering an unfamiliar and risky foreign market.

Design/methodology/approach

The authors carried out an empirical study on foreign banks' entry to the newly opened up Chinese banking market and modelled location strategies of foreign banks in China as a conditional logit problem, in which the dependent variable is the market chosen by an investor. To investigate the determinants of foreign banks' location choices in China, the authors collected data of foreign banks' entries into China during 1980‐2006.

Findings

The main empirical results are: asymmetric information, firm size and entry sequence are significant determinants of foreign banks' location strategies.

Originality/value

The paper presents a new set of results.

Details

Nankai Business Review International, vol. 4 no. 2
Type: Research Article
ISSN: 2040-8749

Keywords

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Article
Publication date: 26 August 2019

Ibrahim M. Al-Jabri, Mustafa I. Eid and Amer Abed

Customer privacy and security are major concerns. Online firms worldwide collect customer data for various reasons. This study aims to investigate factors that motivate and hinder…

1857

Abstract

Purpose

Customer privacy and security are major concerns. Online firms worldwide collect customer data for various reasons. This study aims to investigate factors that motivate and hinder a customer’s willingness to disclose personal information (WTD) to online firms on e-commerce websites.

Design/methodology/approach

Based on an extensive literature review, three sets of factors have been identified. These sets of factors are privacy concern, perceived disclosure benefits and privacy assurances. It is hypothesized that privacy concerns negatively affect the disclosure of personal information, while the perceived benefits of disclosure have positive effects. Privacy assurances would positively affect information disclosure and attenuate the negative effect of privacy concerns on the disclosure of personal information. The authors gathered data from 253 online customers in Saudi Arabia.

Findings

The results indicate that perceived disclosure benefits and privacy concerns have a significant positive and negative relationship, respectively, with WTD online. Privacy assurances had neither a direct nor a moderating effect on information disclosure.

Research limitations/implications

The findings will inform online firms about the factors that prevent or motivate customers to disclose personal information.

Originality/value

The effect of privacy concerns and benefits on personal information disclosure are not fully understood in Saudi Arabia. This study reveals more insights into the specific factors that make online customers reluctant or motivated to disclose their personal information.

Details

Information & Computer Security, vol. 28 no. 2
Type: Research Article
ISSN: 2056-4961

Keywords

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Article
Publication date: 3 April 2019

Zhaoqiang Wang, Jun Cheng, Hong Ji, Shan Hu and Hao Chen

The purpose of this paper is to study the effects of single parameters for temperature characteristics of oil film in port plate pair and the relationship of calculated results…

297

Abstract

Purpose

The purpose of this paper is to study the effects of single parameters for temperature characteristics of oil film in port plate pair and the relationship of calculated results and experimental results under different viscosity.

Design/methodology/approach

The paper established the mathematical model of oil film of port plate pair, calculated the energy equation of port plate pair, simulated for the oil film and temperature distribution and selected different kinds of lubricants to analyze the calculated value and the experimental value.

Findings

The results show: temperature rise of port plate pair is reduced with the increase of oil viscosity; temperature rise of port plate pair is decreased with rise of initial oil film thickness; temperature rise of port plate pair is increased with the rise of cylinder body speed, inclination angle and sealing belt width; and through the comparison of calculated value and experimental value, under the same viscosity and cylinder speed, experimental results are bigger.

Originality/value

This paper used the methods that the temperature of port plate pair was calculated numerically, and the results were consistent with experimental results, so it can get high precision.

Details

Industrial Lubrication and Tribology, vol. 71 no. 4
Type: Research Article
ISSN: 0036-8792

Keywords

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Article
Publication date: 25 July 2024

Mengxia Jiang, Yang Liu, Yuxiong Xue, Guangbao Shan, Jun Lv and Mairui Huang

This paper aims to systematically study the effects of reflow temperature and SAC0307 (SAC) content on the micromorphology and mechanical properties of Sn58Bi-xSAC0307 composite…

77

Abstract

Purpose

This paper aims to systematically study the effects of reflow temperature and SAC0307 (SAC) content on the micromorphology and mechanical properties of Sn58Bi-xSAC0307 composite solder joints to meet the requirements of high integration and low-temperature packaging of devices and provide references for the application of composite solder joints.

Design/methodology/approach

Sn58Bi and SAC0307 solder paste was mechanically mixed in different proportions to prepare Sn58Bi-xSAC0307/ENIG solder joints. The thermal properties, microstructure and mechanical properties of the composite solder joints were studied.

Findings

As SAC content in the solder increases, the balling temperature of SnBi-SAC solder gradually increases. The addition of SAC alloy reduces the grain size of large Bi-rich phase, and there are small-sized dispersed Bi and Ag3Sn particles in the bulk solder. The intermetallic compounds composition of the SnBi-xSAC/ENIG solder joint changes from Ni3Sn4 to (Ni, Cu)3Sn4 and (Cu, Ni)6Sn5 with SAC increasing. As the soldering temperature increases, the strength of all solder joints shows a rising trend. Among them, the shear strength of SnBi-20SAC solder joints at a reflow temperature of 150°C is approximately 37 MPa. As the reflow temperature increases to 250°C, the shear strength of solder joints increases to approximately 67 MPa.

Originality/value

This study provides a reference for the optimization of low-temperature solder composition and soldering process under different package designs.

Details

Soldering & Surface Mount Technology, vol. 36 no. 4
Type: Research Article
ISSN: 0954-0911

Keywords

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Article
Publication date: 11 September 2019

Duen-Ren Liu, Yu-Shan Liao and Jun-Yi Lu

Providing online news recommendations to users has become an important trend for online media platforms, enabling them to attract more users. The purpose of this paper is to…

395

Abstract

Purpose

Providing online news recommendations to users has become an important trend for online media platforms, enabling them to attract more users. The purpose of this paper is to propose an online news recommendation system for recommending news articles to users when browsing news on online media platforms.

Design/methodology/approach

A Collaborative Semantic Topic Modeling (CSTM) method and an ensemble model (EM) are proposed to predict user preferences based on the combination of matrix factorization with articles’ semantic latent topics derived from word embedding and latent topic modeling. The proposed EM further integrates an online interest adjustment (OIA) mechanism to adjust users’ online recommendation lists based on their current news browsing.

Findings

This study evaluated the proposed approach using offline experiments, as well as an online evaluation on an existing online media platform. The evaluation shows that the proposed method can improve the recommendation quality and achieve better performance than other recommendation methods can. The online evaluation also shows that integrating the proposed method with OIA can improve the click-through rate for online news recommendation.

Originality/value

The novel CSTM and EM combined with OIA are proposed for news recommendation. The proposed novel recommendation system can improve the click-through rate of online news recommendations, thus increasing online media platforms’ commercial value.

Details

Industrial Management & Data Systems, vol. 119 no. 8
Type: Research Article
ISSN: 0263-5577

Keywords

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Article
Publication date: 3 June 2024

Xin-Jean Lim, Jun-Hwa Cheah, Jennifer Yee-Shan Chang, Weng Marc Lim, Alastair M. Morrison and Yogesh K. Dwivedi

This study synthesises the self-determination theory (SDT), expectation-confirmation model (ECM), and protection motivation theory (PMT) to formulate an integrated theoretical…

480

Abstract

Purpose

This study synthesises the self-determination theory (SDT), expectation-confirmation model (ECM), and protection motivation theory (PMT) to formulate an integrated theoretical framework that elucidates the process of shaping the intention to continue using facial recognition payment (FRP) under the conditional impact of perceived technology security.

Design/methodology/approach

Data from 667 Beijing Winter Olympics visitors with FRP experience were collected through an online survey and analysed using variance based-structural equation modelling (VB-SEM).

Findings

This study reveals that the intention to continue using FRP evolves through three key stages. Initially, in the expectation stage, the multidimensional concept of artificial autonomy (sensing, thought, and action), which is underpinned by self-determination, is pivotal, strongly influencing perceptions of service enhancement and fostering trust in FRP. Subsequently, the confirmation stage underscores the importance of perceived service enhancement and trust as vital drivers in maintaining FRP usage, while also contributing to subjective well-being. Crucially, perceived technology security emerges as a key moderating factor, enhancing positive perceptions and intentions towards FRP, thus influencing its sustained adoption.

Originality/value

This study stands out by revealing the nuanced interplay between artificial autonomy and user perceptions, particularly concerning service enhancement, technology security, and trust, as they influence well-being and the continued adoption of FRP. Robustly grounded in the integrated theoretical framework of SDT, ECM, and PMT, the study’s findings are critical for comprehending the core elements and specific drivers that promote sustained FRP use, especially as we consider its potential widespread implementation. Therefore, this study not only advances theoretical understanding but also offers practical guidance for optimising FRP deployment strategies in a rapidly evolving technological landscape.

Details

Internet Research, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 1066-2243

Keywords

Available. Open Access. Open Access
Article
Publication date: 22 November 2022

Chunlan Li, Xinwu Xu, Hongyu Du, Debin Du, Walter Leal Filho, Jun Wang, Gang Bao, Xiaowen Ji, Shan Yin, Yuhai Bao and Hossein Azadi

The paper aims to investigate the possible changes in mean temperature in the Mongolian Plateau associated with the 1.5 and 2°C global warming targets and how snow changes in the…

841

Abstract

Purpose

The paper aims to investigate the possible changes in mean temperature in the Mongolian Plateau associated with the 1.5 and 2°C global warming targets and how snow changes in the Mongolian Plateau when the mean global warming is well below 2°C or limited to 1.5°C.

Design/methodology/approach

In total, 30 model simulations of consecutive temperature and precipitation days from Coupled Model Inter-comparison Project Phase 5 (CMIP5) are assessed in comparison with the 111 meteorological monitoring stations from 1961–2005. Multi-model ensemble and model relative error were used to evaluate the performance of CMIP5 models. Slope and the Mann–Kendall test were used to analyze the magnitude of the trends and evaluate the significance of trends of snow depth (SD) from 1981 to 2014 in the Mongolian Plateau.

Findings

Some models perform well, even better than the majority (80%) of the models over the Mongolian Plateau, particularly HadGEM2-CC, CMCC-CM, BNU-ESM and GFDL-ESM2M, which simulate best in consecutive dry days (CDD), consecutive wet days (CWD), cold spell duration indicator (CSDI) and warm spell duration indicator (WSDI), respectively. Emphasis zones of WSDI on SD were deeply analysed in the 1.5 and 2 °C global warming period above pre-industrial conditions, because it alone has a significant negative relation with SD among the four indices. It is warmer than before in the Mongolian Plateau, particularly in the southern part of the Mongolian Plateau, indicating less SD.

Originality/value

Providing climate extremes and SD data sets with different spatial-temporal scales over the Mongolian Plateau. Zoning SD potential risk areas and proposing adaptations to promote regional sustainable development.

Details

International Journal of Climate Change Strategies and Management, vol. 14 no. 5
Type: Research Article
ISSN: 1756-8692

Keywords

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