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Article

F. Hongyuan, Q. Yiyu and J. Yihong

Pulse control, SEM analysis and metallographic examination have been used to record and study the process by which a ball is formed at the tip of an ultra‐fine copper…

Abstract

Pulse control, SEM analysis and metallographic examination have been used to record and study the process by which a ball is formed at the tip of an ultra‐fine copper wire. The process by which the copper ball is formed, and the laws governing this process, are presented.

Details

Soldering & Surface Mount Technology, vol. 4 no. 1
Type: Research Article
ISSN: 0954-0911

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Article

F. Hongyuan, Q. Yiyu and J. Yihong

In this paper, the process of forming copper wire balls in copper ball bonding has been studied by numerical analysis. By calculating the temperature field, speed field…

Abstract

In this paper, the process of forming copper wire balls in copper ball bonding has been studied by numerical analysis. By calculating the temperature field, speed field and displacement field for ultra‐fine copper wire under a miniarc, a regular pattern of copper wire ball formation has been observed. The calculation results for the displacement field has also been tested and verified.

Details

Soldering & Surface Mount Technology, vol. 5 no. 3
Type: Research Article
ISSN: 0954-0911

Content available
Article

Haotian Xu, Jingcheng Wang, Hongyuan Wang, Ibrahim Brahmia and Shangwei Zhao

The purpose of this paper is to investigate the design method of partial observer canonical form (POCF), which is one of the important research tools for industrial plants.

Abstract

Purpose

The purpose of this paper is to investigate the design method of partial observer canonical form (POCF), which is one of the important research tools for industrial plants.

Design/methodology/approach

Motivated by the two-steps method proposed in Xu et al. (2020), this paper extends this method to the case of Multi-Input Multi-Output (MIMO) nonlinear system. It decomposes the original system into two subsystems by observable decomposition theorem first and then transforms the observable subsystem into OCF. Furthermore, the necessary and sufficient conditions for the existing of POCF are proved.

Findings

The proposed method has a wide range of applications including completely observable nonlinear system, noncompletely observable nonlinear system, autonomous nonlinear system and forced nonlinear system. Besides, comparing to the existing results (Saadi et al., 2016), the method requires less verified conditions.

Originality/value

The new method concerning design POCF has better plants compatibility and less validation conditions.

Details

Journal of Intelligent Manufacturing and Special Equipment, vol. 1 no. 1
Type: Research Article
ISSN: 2633-6596

Keywords

Content available
Article

Hongyuan Wang and Jingcheng Wang

The purpose of this paper aims to design an optimization control for tunnel boring machine (TBM) based on geological identification. For unknown geological condition, the…

Abstract

Purpose

The purpose of this paper aims to design an optimization control for tunnel boring machine (TBM) based on geological identification. For unknown geological condition, the authors need to identify them before further optimization. For fully considering multiple crucial performance of TBM, the authors establish an optimization problem for TBM so that it can be adapted to varying geology. That is, TBM can operate optimally under corresponding geology, which is called geology-adaptability.

Design/methodology/approach

This paper adopted k-nearest neighbor (KNN) algorithm with modification to identify geological conditions. The modification includes adjustment of weights in voting procedure and similarity distance measurement, which at suitable for engineering and enhance accuracy of prediction. The authors also design several key performances of TBM during operation, and built a multi-objective function. Further, the multi-objective function has been transformed into a single objective function by weighted-combination. The reformulated optimization was solved by genetic algorithm in the end.

Findings

This paper provides a support for decision-making in TBM control. Through proposed optimization control, the advance speed of TBM has been enhanced dramatically in each geological condition, compared with the results before optimizing. Meanwhile, other performances are acceptable and the method is verified by in situ data.

Originality/value

This paper fulfills an optimization control of TBM considering several key performances during excavating. The optimization is conducted under different geological conditions so that TBM has geological-adaptability.

Details

Journal of Intelligent Manufacturing and Special Equipment, vol. 1 no. 1
Type: Research Article
ISSN: 2633-6596

Keywords

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Article

Feng Cheng and Weixi Ji

Cavitation bubbles cannot be avoided in the hydraulic system. Because of instability of flow and variation of water pressure, the jet often occurs in a bubble collapse…

Abstract

Purpose

Cavitation bubbles cannot be avoided in the hydraulic system. Because of instability of flow and variation of water pressure, the jet often occurs in a bubble collapse. This study aims to accurately predict the shape, velocity and time of the resulting jet, so as to inhibit cavitation erosion.

Design/methodology/approach

In the study, a theoretical model of cavitation bubbles in the water has been developed by applying a periodic water film pressure into the Rayleigh–Plesset equation. A fourth-order in time Runge–Kutta scheme is used to obtain an accurate computation of the bubble dynamic characteristics. The behavior of the proposed theory is further simulated in a high-speed photography experiment by using a cavitation bubble test rig. The evolution with time of cavitation bubbles is further obtained.

Findings

A comparison with the available experimental results reveals that the bubble evolution with time has a duration of about 0.3T0, that well predicts the expanding and compressing process of cavitation bubbles. The results also show that the initial bubble radius in the water influences the moving velocity of the bubble wall, whereas the perturbation frequency of the water pressure has less effect on the velocity of the bubble wall.

Originality/value

A theoretical model well predicts dynamic characteristics of cavitation bubbles. The bubble evolution with time has a duration of about 0.3T0, Initial bubble radius influences the velocity of bubble wall. Perturbation frequency has less effect on the velocity of bubble wall.

Details

Industrial Lubrication and Tribology, vol. 70 no. 6
Type: Research Article
ISSN: 0036-8792

Keywords

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Article

Shiyu Wang, Yan Zhang, Guanzhen Wang and Zhibin Chen

This paper answers, in the Chinese stock market, who can realize the “spot value” of corporate social responsibility (CSR).

Abstract

Purpose

This paper answers, in the Chinese stock market, who can realize the “spot value” of corporate social responsibility (CSR).

Design/methodology/approach

The authors use event-study to build the research framework. Using CSR report content analysis, the authors measure the specification level of CSR disclosure. Applying the Baidu index, the authors mine Chinese investors’ profiles data to investigate retail investor heterogeneity closely.

Findings

The authors find strong evidence that the measure captures a behavioral bias in CSR pricing: firms that choose to disclose CSR report experience positive abnormal return more among retail investors than institutional investors, more among young investors than older, but no difference between female and male investors.

Practical implications

For Chinese public firms, the authors give them evidence that they can realize positive abnormal returns by applying certain CSR disclosure strategies. For Chinese investors, especially retail investors and youths, the authors ask them to rethink whether their positive evaluation of CSR is a rational trade-off choice or whether they are fooled by the “hedging mask” and “attention-grabbing.”

Social implications

The findings can give some suggestions to regulators: encouraging voluntary disclosure and reducing mandatory disclosure can drive enterprises to engage in more CSR activities because the voluntarily CSR disclosure can realize both long-term value and “spot value.” Complementarily, a more rigorous CSR report auditing regulation can suppress the “greenwash” by increasing the “lying cost.”

Originality/value

Using behavioral finance theory, the authors connect the gap between neoclassical research on the “U-shaped” value realization of CSR and the increasing voluntary CSR disclosure in the Chinese market. The authors find that heuristic reason and emotionality orientation results in the Chinese “CSR-friendly” market.

Details

Sustainability Accounting, Management and Policy Journal, vol. 11 no. 4
Type: Research Article
ISSN: 2040-8021

Keywords

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Article

Xiaoning Li, Xinbo Liao, Qingwen Zhong, Kai Zheng, Shaoxing Chen, Xiao-Jun Chen, Jin-Xiu Zhu and Hongyuan Yang

The purpose of this paper is to analyze the influencing factors of patients’ financial burden through a case study of hospital on public‒private partnerships (PPP) model…

Abstract

Purpose

The purpose of this paper is to analyze the influencing factors of patients’ financial burden through a case study of hospital on public‒private partnerships (PPP) model (Chaonan Minsheng Hospital of Guangdong Province) and provide some useful information to policymakers for better development of hospitals on PPP model.

Design/methodology/approach

There are total six indicators that are defined as patients’ financial burden, basing on the policy of “indicators of medical quality management and control on the third level large general hospital (2011 edition),” issued by Chinese Government. In total, 23 potentially influencing factors of patients’ financial burden for hospital on PPP model were chosen from the above policy. The five-year (2007‒2011) data for the above 29 indicators come from statistic department of hospital on PPP model. Grey relational analysis (GRA) was applied to analyze the influencing factors of patients’ financial burden for hospital on PPP model.

Findings

A clear rank of influencing factors of patients’ financial burden is obtained and suggestions are provided from results of GRA, which provide reference for policymakers of hospital on PPP model. The five main influencing factors of patients’ financial burden for hospital on PPP model, in sequence, are rescuing critical ill patients on emergency, rescuing critical ill inpatients, inpatient bed occupancy rate, working days per bed and medical building area.

Originality/value

The study on the influencing factors of patients’ financial burden for hospital on PPP model not only provides decision-making for policymaker of hospital and controlling of medical expenditure but also contributes to release patients’ financial burden for hospitals on PPP model.

Details

Grey Systems: Theory and Application, vol. 9 no. 2
Type: Research Article
ISSN: 2043-9377

Keywords

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Article

Leping Huang, Hongyuan Chen, T.V.L.N. Sivakumar, Tsuyoshi Kashima and Kaoru Sezaki

To utilize Bluetooth as a layer 2 multi‐hop subnet for global IP network, there are two missing protocols in current Bluetooth stack: network formation and routing. In…

Abstract

To utilize Bluetooth as a layer 2 multi‐hop subnet for global IP network, there are two missing protocols in current Bluetooth stack: network formation and routing. In this paper, we propose our network formation and routing protocols optimized for such Bluetooth subnset usage scenarios to fill this gap. In this paper, we first present some observations on performance degradations of Bluetooth PAN due to network topologies and topology change when radio independant protocols are implemented. And then we analyze the reason of performance degradation. Based on our analysis, we first propose a flexible scatternet formation algorithm under conference scenario for multi‐hop communication. By using proposed method, scatternet can be formed flexibly with star, mesh, or linked line based on several parameters like number of maximum piconets that a gateway Bluetooth device can participate, and whether loops are needed in the resulting scatternet to achieve better network performance. To utilize topology information in multi‐hop communication, we propose a Cross‐layer Optimized Routing for Bluetooth (CORB) CORB is a QoS‐extended AODV routing protocol with mainly two optimizations between networking layer and underlying Bluetooth MAC layer. The first optimization is to use a new load metric. (LM) in QoS routing protocol instead of number of hops in conventional best effort routing. LM is derived from estimation of nodes’ link bandwidth, which reflects the different roles of nodes in Bluetooth scatternet. This proposal helps routing protocol to bypass heavily loaded nodes, and find route with larger bandwidth. The second optimization is to adjust LM and some MAC layer parameters in response to the unstable network topology caused by movement and change of indoor radio condition. Finally, We present some simulation and experiment results based on implementation, which prove the effectiveness of our protocols.

Details

International Journal of Pervasive Computing and Communications, vol. 1 no. 2
Type: Research Article
ISSN: 1742-7371

Keywords

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Article

Awais Ali, Fu Qiang and Sadia Ashraf

The purpose of this paper is to analyse the impact of ownership structure on firm valuation and performance across different geographical regions within mainland China.

Abstract

Purpose

The purpose of this paper is to analyse the impact of ownership structure on firm valuation and performance across different geographical regions within mainland China.

Design/methodology/approach

The authors classify China in six geographical regions and use cross-sectional data of companies with A-shares listed on domestic stock exchanges in China for the year-end 2015. Using data from CSMAR and Wind database, they use multivariate regression technique and analytically compare the consistency of relationship between operational variables of ownership structure with corporate performance and evaluation.

Findings

The authors find that institutional ownership and state ownership negatively affect market valuation throughout various geographical regions of China. Further, in East, Northwest, South Central and Southwestern parts of China, managerial ownership and concentration of shareholding among top ten shareholders positively influence return on equity (ROE). Interestingly, institutional shareholding negatively affects return on assets (ROA), while institutional ownership has a neutral effect on profitability margin in Northeast China. Although in northern part of China, this relationship is slightly positive. In East China region, state ownership and ownership concentration are directly proportional to profitability margin.

Practical implications

As some of the findings exhibit weak state of market efficiency in some regions, the study may also be useful in identifying arbitrage opportunities across different regions. Moreover, this study suggests that regions with the same business environment and conditions anywhere around the globe invite same or similar ownership structure for better firm performance and valuation.

Originality/value

The study provides unique understanding of relationship between ownership structure, market valuation and firm performance in various parts of China and will be an addition to the relevant literature. Given a change in company’s ownership structure and considering its region of incorporation, this study will help investment analysts in assessing performance and market valuation of the firm. It will also assist several classes of investors, financial institutions and international businesses in making their investment decisions.

Details

Review of International Business and Strategy, vol. 28 no. 1
Type: Research Article
ISSN: 2059-6014

Keywords

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Article

Hongyuan Wang, Rutvij Mehta, Lawrence Chung, Sam Supakkul and Liguo Huang

In order for a software system to better serve the user, it should be able to adjust its behavior according to the changing needs in the environment. Oftentimes, selecting…

Abstract

Purpose

In order for a software system to better serve the user, it should be able to adjust its behavior according to the changing needs in the environment. Oftentimes, selecting a particular action may depend upon various non‐functional requirements (NFRs) such as safety, cost, and so on. In the past, the many possible alternatives for an adaptation action by and large have not been considered systematically and rationally, keeping various NFRs in mind, hence, resulting in low‐level of confidence that such an action is indeed a best possible one that is really desirable. The purpose of this paper is to present a goal‐oriented approach to select alternative(s) based on a particular contextual event, while considering important NFRs.

Design/methodology/approach

The paper proposes a goal‐oriented approach in which various NFRs are treated as softgoals to be satisficed and used in exploring, analyzing and selecting among possible adaptation alternatives, in consideration of the particular contextual event.

Findings

Without the goal‐oriented methodology, which offers an ontology enriched with the notion of goals for contextual information and also integrates rules for triggering adaptation, the authors feel, through their scenario study applied to their smart‐phone application, that some critical issues might not have been considered in building a usable, useful system.

Originality/value

The concepts introduced in this paper provide a systematic and rational approach to select adaptation alternative(s), considering NFRs along with detecting a contextual event.

Details

International Journal of Pervasive Computing and Communications, vol. 8 no. 3
Type: Research Article
ISSN: 1742-7371

Keywords

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