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Article
Publication date: 1 February 2013

Xin Luo, Wenhui Du, Xiuzhen Lu, Toshikazu Yamaguchi, Gavin Jackson, Li lei Ye and Johan Liu

The composition and thickness of surface oxide of solder particles is extremely important to the quality of interconnect and reliability of packaged system. The purpose of…

Abstract

Purpose

The composition and thickness of surface oxide of solder particles is extremely important to the quality of interconnect and reliability of packaged system. The purpose of this paper is to develop an observable measurement to research the issue.

Design/methodology/approach

AES (Auger electron spectroscopy), XPS (X‐ray photoelectron spectroscopy), TEM (transmission electron microscopy) and STEM (scanning transmission electron microscopy) were employed to examine the oxide layer on microscale solder powders. Conventional techniques and FIB (Focus Ion Beam) were employed for the TEM sample preparation. High angle annular dark field (HAADF) pattern was applied to distinguish the oxide layer and the solder matrix by the contrast of average atomic number. The results were confirmed by AES and XPS measurement.

Findings

The solder powders were exposed to air (70% relative humidity) at 150°C for 0, 120 and 240 h for the accelerated growth of oxide. The surface oxide thickness was 6 nm and 50 nm measured by TEM for 0 h and 120 h samples, respectively. It was found that the increase in surface oxide thickness of solder particles is proportional to the rooting of time. The elemental distribution along the oxide was quantified by line scanning using STEM and the atomic ratio of Sn to O in the oxide layer nearer to the outer, the middle, and the inner (adjacent to the solder matrix) was found to be 1:2, 2:3 and 1:1, respectively. The result was validated using XPS which gave Sn to O ratio of 1:2 at 5 nm depth of surface oxide.

Originality/value

This is the first time FIB technology has been used to prepare TEM specimens for solder particles and TEM pictures shown of their surface oxide layer. Though requiring more care in sample preparation, the measurements by TEM and STEM are believed to be more direct and precise.

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Article
Publication date: 1 June 2005

Li‐teh Sun

Man has been seeking an ideal existence for a very long time. In this existence, justice, love, and peace are no longer words, but actual experiences. How ever, with the…

Abstract

Man has been seeking an ideal existence for a very long time. In this existence, justice, love, and peace are no longer words, but actual experiences. How ever, with the American preemptive invasion and occupation of Afghanistan and Iraq and the subsequent prisoner abuse, such an existence seems to be farther and farther away from reality. The purpose of this work is to stop this dangerous trend by promoting justice, love, and peace through a change of the paradigm that is inconsistent with justice, love, and peace. The strong paradigm that created the strong nation like the U.S. and the strong man like George W. Bush have been the culprit, rather than the contributor, of the above three universal ideals. Thus, rather than justice, love, and peace, the strong paradigm resulted in in justice, hatred, and violence. In order to remove these three and related evils, what the world needs in the beginning of the third millenium is the weak paradigm. Through the acceptance of the latter paradigm, the golden mean or middle paradigm can be formulated, which is a synergy of the weak and the strong paradigm. In order to understand properly the meaning of these paradigms, however, some digression appears necessary.

Details

International Journal of Sociology and Social Policy, vol. 25 no. 6/7
Type: Research Article
ISSN: 0144-333X

Keywords

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Article
Publication date: 1 April 2005

Li‐teh Sun

Man has been seeking an ideal existence for a very long time. In this existence, justice, love, and peace are no longer words, but actual experiences. How ever, with the…

Abstract

Man has been seeking an ideal existence for a very long time. In this existence, justice, love, and peace are no longer words, but actual experiences. How ever, with the American preemptive invasion and occupation of Afghanistan and Iraq and the subsequent prisoner abuse, such an existence seems to be farther and farther away from reality. The purpose of this work is to stop this dangerous trend by promoting justice, love, and peace through a change of the paradigm that is inconsistent with justice, love, and peace. The strong paradigm that created the strong nation like the U.S. and the strong man like George W. Bush have been the culprit, rather than the contributor, of the above three universal ideals. Thus, rather than justice, love, and peace, the strong paradigm resulted in in justice, hatred, and violence. In order to remove these three and related evils, what the world needs in the beginning of the third millenium is the weak paradigm. Through the acceptance of the latter paradigm, the golden mean or middle paradigm can be formulated, which is a synergy of the weak and the strong paradigm. In order to understand properly the meaning of these paradigms, however, some digression appears necessary.

Details

International Journal of Sociology and Social Policy, vol. 25 no. 4/5
Type: Research Article
ISSN: 0144-333X

Keywords

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Article
Publication date: 30 December 2020

Ming-Yang Li, Xiao-Jie Zhao, Lei Zhang, Xin Ye and Bo Li

In recent years, the updating speed of products has been significantly accelerated, which not only provides diversified styles for consumers to select from but also makes…

Abstract

Purpose

In recent years, the updating speed of products has been significantly accelerated, which not only provides diversified styles for consumers to select from but also makes consumers face selection problems sometimes. In addition, a large number of online reviews for products emerge on many e-commerce websites and influence consumers’ purchasing decisions. The purpose of this study is to propose a method for product selection considering consumer’s expectations and online reviews to support consumers’ purchasing decisions.

Design/methodology/approach

The product attributes are divided into two categories, i.e. demand attributes and word-of-mouth (WOM) attributes. For the demand attributes, for which the consumers can give specific quantified expectations, the value function of prospect theory is used to determine the consumer’s perceived values to the alternative products according to consumers’ expectations for these attributes and products’ specifications. For the WOM attributes, for which the consumers cannot give specific quantified expectations, the sentiment analysis method is used to identify the sentiment strengths for these attributes in the online reviews, and then the consumer’s perceived values to the alternative products are determined. On this basis, the product selection methods for single consumers and group consumers are given respectively.

Findings

Finally, taking the data of JD.com (https://www.jd.com/) as an example, the practicability and rationality of the method proposed in this paper is validated.

Originality/value

First, a new product selection problem considering consumer’s expectations and online reviews is extracted. Second, the product attributes are considered more comprehensively and are classified into two main categories. Third, the bounded rationality of the consumers in the decision-making process is described more reasonably. Fourth, the sentiment dictionaries for each WOM attribute are constructed and the algorithm step of identifying the sentiment strengths is designed, which can help to identify the sentiment strengths in the online reviews more accurately. Fifth, the situation that a group plans to purchase the same products and the members have inconsistent expectations for the product attributes is considered.

Details

Kybernetes, vol. 50 no. 9
Type: Research Article
ISSN: 0368-492X

Keywords

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Article
Publication date: 3 January 2017

Jiazhi Lei, Qingwu Gong and Jun Ye

This paper aims to propose a simplified model of vanadium redox flow batteries (VRBs) for VRB energy storage system (ESS) design considering the operational…

Abstract

Purpose

This paper aims to propose a simplified model of vanadium redox flow batteries (VRBs) for VRB energy storage system (ESS) design considering the operational characteristics of VRB, and a VRB ESS, considering the low terminal voltage of VRB, was presented.

Design/methodology/approach

According to the designed topology of VRB ESS and the simplified model of VRB, a small perturbation analysis method was used to establish the transfer function of VRB ESS, and the controller parameters of VRB ESS under constant charging and discharging current were designed.

Findings

Test results have demonstrated that this designed VRB ESS has fast response, small overshoot, strong adaptation and high steady precision, which strongly verified the reasonable design.

Practical implications

This simplified model of VRB can be suitably used for VRB ESS design. This designed VRB ESS realized the bidirectional power flow of VRB and AC grid. In this designed VRB ESS, phase-shifted full-bridge converter and a single-phase inverter were used and VRB was charged and discharged under constant current.

Originality/value

The paper presents a topology of VRB ESS which can realize the bidirectional power flow of VRB and AC grid. Considering the complexity of VRB model, a simplified model of VRB was proposed for the controller parameters design of VRB ESS, and this method can be used in application.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 36 no. 1
Type: Research Article
ISSN: 0332-1649

Keywords

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Article
Publication date: 30 August 2019

Fujuan Tong, Wenxuan Gou, Lei Li, Zhufeng Yue, Wenjing Gao and Honglin Li

In order to improve the engine reliability and efficiency, an effective way is to reform the turbine blade tip conformation. The paper aims to discuss this issue.

Abstract

Purpose

In order to improve the engine reliability and efficiency, an effective way is to reform the turbine blade tip conformation. The paper aims to discuss this issue.

Design/methodology/approach

The present research provides several novel tip-shaping structures, which are considered to control the blade tip loss. Four different tip geometries have been studied: flat tip, squealer tip, flat tip with streamwise ribs and squealer tip with streamwise ribs. The tip heat transfer and leakage flow are both analyzed in detail, for example the tip heat transfer coefficient, tip flow and local pressure distributions.

Findings

The results show that the squealer seal and streamwise rib can reduce the tip heat transfer and leakage loss, especially for the squealer tip with streamwise ribs. The tip and near-tip flow patterns at the different locations of axial chord reflect that both the squealer seal and streamwise rib structure can control the tip leakage flow loss. In addition, the analysis of the aerodynamic parameters (the static pressure and turbine efficiency) also indicates that the squealer tip with streamwise ribs obtains the highest adiabatic efficiency with an increase of 2.34 percent, compared with that of the flat tip case.

Originality/value

The analysis of aerothermal and dynamic performance can provide a reference for the blade tip design and treatment.

Details

Multidiscipline Modeling in Materials and Structures, vol. 15 no. 6
Type: Research Article
ISSN: 1573-6105

Keywords

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Article
Publication date: 16 July 2020

Diana Baker, Helen McCabe, Mary Kelly and Tian Jiang

Findings from a comparative qualitative study with parents in the USA and China increase the understanding of experiences of adults with autism in both countries.

Abstract

Purpose

Findings from a comparative qualitative study with parents in the USA and China increase the understanding of experiences of adults with autism in both countries.

Design/methodology/approach

Semi-Structured interviews were conducted with families in the USA and in China. In total, 18 families participated in the study – 7 in the USA, 11 in China.

Findings

Analysis of the comparative data led to the emergence of three overarching themes, expressing both similarities and differences in experiences: 1) transition to adult services plays out differently in the two nations, 2) parent advocacy and efforts in supporting and securing services for their children are strong in both countries but are also defined by the variability in access to services and 3) due to the scarcity of adult services in their country, Chinese parents express significantly more worries about their own aging and mortality as compared with USA parents.

Research limitations/implications

Practical implications and directions for future research are discussed.

Originality/value

By examining the experiences of families of adults with autism in the USA and China, the research reveals themes that would not be visible in a single-nation study.

Details

Advances in Autism, vol. 6 no. 3
Type: Research Article
ISSN: 2056-3868

Keywords

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Article
Publication date: 4 October 2018

Zhiming Chen, Lei Li, Yunhua Wu, Bing Hua and Kang Niu

On-orbit service technology is one of the key technologies of space manipulation activities such as spacecraft life extension, fault spacecraft capture, on-orbit debris…

Abstract

Purpose

On-orbit service technology is one of the key technologies of space manipulation activities such as spacecraft life extension, fault spacecraft capture, on-orbit debris removal and so on. It is known that the failure satellites, space debris and enemy spacecrafts in space are almost all non-cooperative targets. Relatively accurate pose estimation is critical to spatial operations, but also a recognized technical difficulty because of the undefined prior information of non-cooperative targets. With the rapid development of laser radar, the application of laser scanning equipment is increasing in the measurement of non-cooperative targets. It is necessary to research a new pose estimation method for non-cooperative targets based on 3D point cloud. The paper aims to discuss these issues.

Design/methodology/approach

In this paper, a method based on the inherent characteristics of a spacecraft is proposed for estimating the pose (position and attitude) of the spatial non-cooperative target. First, we need to preprocess the obtained point cloud to reduce noise and improve the quality of data. Second, according to the features of the satellite, a recognition system used for non-cooperative measurement is designed. The components which are common in the configuration of satellite are chosen as the recognized object. Finally, based on the identified object, the ICP algorithm is used to calculate the pose between two frames of point cloud in different times to finish pose estimation.

Findings

The new method enhances the matching speed and improves the accuracy of pose estimation compared with traditional methods by reducing the number of matching points. The recognition of components on non-cooperative spacecraft directly contributes to the space docking, on-orbit capture and relative navigation.

Research limitations/implications

Limited to the measurement distance of the laser radar, this paper considers the pose estimation for non-cooperative spacecraft in the close range.

Practical implications

The pose estimation method for non-cooperative spacecraft in this paper is mainly applied to close proximity space operations such as final rendezvous phase of spacecraft or ultra-close approaching phase of target capture. The system can recognize components needed to be capture and provide the relative pose of non-cooperative spacecraft. The method in this paper is more robust compared with the traditional single component recognition method and overall matching method when scanning of laser radar is not complete or the components are blocked.

Originality/value

This paper introduces a new pose estimation method for non-cooperative spacecraft based on point cloud. The experimental results show that the proposed method can effectively identify the features of non-cooperative targets and track their position and attitude. The method is robust to the noise and greatly improves the speed of pose estimation while guarantee the accuracy.

Details

International Journal of Intelligent Computing and Cybernetics, vol. 12 no. 1
Type: Research Article
ISSN: 1756-378X

Keywords

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Article
Publication date: 1 September 2020

Lei Li, Bo Liu and Huimin Mu

This paper investigates the paths through which innovation community affects content providers' new service development (NSD) performance in technology-based service…

Abstract

Purpose

This paper investigates the paths through which innovation community affects content providers' new service development (NSD) performance in technology-based service ecosystem and contingency factors exist in the paths.

Design/methodology/approach

The research model is built based on service-dominant (S-D) logic, exploring the relationship among innovation community, content providers' knowledge acquisition and content providers' NSD performance as well as the moderating role of content providers' technology readiness and content providers' complexity. Using survey data collected from 386 content providers of selected open network platforms in China, this study finds broad support for the proposed research model.

Findings

The findings of this paper reveal that content providers' tacit knowledge acquisition from users plays a mediating role between the innovation community and new service ratings. Content providers' technology readiness plays a positive moderating role in the relationship between innovation community and their explicit or tacit knowledge acquisition. Content providers' task complexity negatively moderates the effects of their explicit knowledge acquisition from users on new service volumes or ratings, but positively moderates the effects of tacit knowledge acquisition from users on new service volumes or ratings.

Originality/value

Though extant literature highlights the importance of knowledge acquisition in NSD performance, few studies explore the antecedents of content providers' knowledge acquisition from users and the paths through which these antecedents affect content providers' NSD performance. Moreover, boundary conditions exist in the process of improving NSD performance are generally ignored in previous literature. With the lens of S-D logic, this paper explicates how content providers of different technology readiness and different task complexity enhance their new service volumes and ratings through acquiring explicit and tacit knowledge from users in innovation community. Adopting S-D logic from marketing area to NSD area, this paper not only enriches the theoretical accumulations of antecedents and boundary conditions of content providers' NSD performance but also offers insights for content providers and users on how to synergistically advance NSD activities and co-create value in the technology-based service ecosystem.

Details

Industrial Management & Data Systems, vol. 120 no. 10
Type: Research Article
ISSN: 0263-5577

Keywords

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Article
Publication date: 16 February 2015

Yong Ye, Lei Huang and Ming Li

– The purpose of this paper is to analyze the relationship among negative media coverage, law environment and tunneling of controlling shareholders.

Abstract

Purpose

The purpose of this paper is to analyze the relationship among negative media coverage, law environment and tunneling of controlling shareholders.

Design/methodology/approach

Under the Chinese especial institutional background, this paper empirically test the relationship among negative media coverage, law environment and tunneling of controlling shareholders with the sample of 2009-2011 Chinese listed companies.

Findings

The empirical results demonstrate that negative media coverage can reduce tunneling of controlling shareholder, and compared with state-owned listed companies, negative media coverage have a greater effect on tunneling in non-state-owned listed companies; and negative media coverage have a greater effect on tunneling in areas with better law environment. Further study shows that the reduction of controlling shareholder’s behavior of tunneling can improve company performance, and the improvement is more significant in non-state-owned listed companies and areas with better law environment. The research results indicate that media coverage play a very active role on restraining stakeholder’s behavior and perfecting corporate governing.

Originality/value

First, this paper will study of tunneling from the perspective of media coverage for the first time. Second, this paper further analyzes how the decrease of tunneling improves corporate performance following the research of how media coverage influence tunneling. Third, this study enrich literatures about the effects of media coverage on corporate governance in Chinese capital market.

Details

China Finance Review International, vol. 5 no. 1
Type: Research Article
ISSN: 2044-1398

Keywords

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