This paper reports on thermal strain analysis of integrated circuit (IC) packages using the optical, atomic force microscope (AFM), and scanning electron microscope (SEM) Moir�…
Abstract
This paper reports on thermal strain analysis of integrated circuit (IC) packages using the optical, atomic force microscope (AFM), and scanning electron microscope (SEM) Moiré methods. The advantages and disadvantages of a full field optical Moiré, a micro‐optical Moiré, AFM Moiré, and SEM Moiré methods are compared. The full field Moiré interferometry is used to investigate the deformations and strains induced by thermal loading in various packages at the macrolevel. The micro Moiré interferometry is used to study the strains in the small solder joints. An optical Moiré interferometer with a mini thermal‐cycling chamber can be used for real time measurements of thermal deformations and strains of IC packages under thermal testing. Furthermore, the novel methods, AFM Moiré and SEM Moiré, can be also utilized to measure thermally induced deformations and strains of IC packages conveniently using the equipment that is commonly and primarily used for many other applications.
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Xianan Li, Zhong Lu and Jingyi Wang
Development assurance level (DAL) is the measurement of the rigor of development assurance tasks performed to functions or items. The DAL assignment is an important process of…
Abstract
Purpose
Development assurance level (DAL) is the measurement of the rigor of development assurance tasks performed to functions or items. The DAL assignment is an important process of aircraft system development that can make the reliability and safety of the system stay at acceptable levels. This paper aims to propose an optimization approach for the DAL assignments to minimize the development cost of aircraft systems.
Design/methodology/approach
The mathematical model for the DAL assignment optimization has been developed on the basis of the given expressions of objective function and constraints. In addition, a hybrid algorithm model synthesizing the advantages of genetic algorithm (GA) and Tabu search (TS) has been proposed to solve the optimization problem of the DAL assignment.
Findings
The results of the case study show that the proposed hybrid algorithm is more efficient and effective than the exhaustive method as well as the pure GA.
Practical implications
The proposed approach can be applied in the development of aircraft systems, and it has great significance in minimizing the development cost as well as keeping the system reliability and safety at an acceptable level.
Originality/value
The constrained optimization method has been applied in the DAL assignments, the corresponding mathematical model has been built and a hybrid evolutionary algorithm has been proposed to solve the optimization problem.
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Zhong-Lu Teng and Jin Han
This study aims to provide evidence on the association between abnormal tone and audit fees, as well as between abnormal tone and audit report lag.
Abstract
Purpose
This study aims to provide evidence on the association between abnormal tone and audit fees, as well as between abnormal tone and audit report lag.
Design/methodology/approach
This study uses a fixed-effects model to examine the relationship between abnormal positive tone and audit engagement (audit fees and audit report lag). Following Blanco et al., the authors used propensity score matching to examine the robustness of the findings.
Findings
Abnormal positive tone affects the audit process. An abnormal positive tone in annual reports is associated with greater audit effort and higher audit fees.
Originality/value
This study contributes to the determinants of audit fees and audit lag by analyzing the impact of an abnormal positive tone on audit engagement. The literature analyzing the determinants of audit engagement often focuses on the quality of non-textual information. This study analyzes the impact of the quality of textual information (measured by abnormal tone) on audit engagement, which provides evidence of the association between textual disclosure and audit.
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Zhao Alexandre Huang and Rui Wang
Using the theoretical frameworks of public diplomacy and public relations, we mapped how the Chinese government has used panda imagery to build its national brand on Twitter and…
Abstract
Using the theoretical frameworks of public diplomacy and public relations, we mapped how the Chinese government has used panda imagery to build its national brand on Twitter and how this ‘panda diplomacy’ has facilitated its para-diplomatic actions. Our findings uncover new attempts by the Chinese government to engage in digital diplomacy. Mobilizing panda imagery on Twitter enhanced friendly relations with foreign political leaders and people and established a friendly and peaceful image of China on Twitter.
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Lei Gan, Anbin Wang, Zheng Zhong and Hao Wu
Data-driven models are increasingly being used to predict the fatigue life of many engineering components exposed to multiaxial loading. However, owing to their high data…
Abstract
Purpose
Data-driven models are increasingly being used to predict the fatigue life of many engineering components exposed to multiaxial loading. However, owing to their high data requirements, they are cost-prohibitive and underperforming for application scenarios with limited data. Therefore, it is essential to develop an advanced model with good applicability to small-sample problems for multiaxial fatigue life assessment.
Design/methodology/approach
Drawing inspiration from the modeling strategy of empirical multiaxial fatigue models, a modular neural network-based model is proposed with assembly of three sub-networks in series: the first two sub-networks undergo pretraining using uniaxial fatigue data and are then connected to a third sub-network trained on a few multiaxial fatigue data. Moreover, general material properties and necessary loading parameters are used as inputs in place of explicit damage parameters, ensuring the universality of the proposed model.
Findings
Based on extensive experimental evaluations, it is demonstrated that the proposed model outperforms empirical models and conventional data-driven models in terms of prediction accuracy and data demand. It also holds good transferability across various multiaxial loading cases.
Originality/value
The proposed model explores a new avenue to incorporate uniaxial fatigue data into the data-driven modeling of multiaxial fatigue life, which can reduce the data requirement under the promise of maintaining good prediction accuracy.
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Z.W. Zhong, T.Y. Tee and J‐E. Luan
This paper seeks to review recent advances in wire bonding, flip chip and lead‐free solder for advanced microelectronics packaging.
Abstract
Purpose
This paper seeks to review recent advances in wire bonding, flip chip and lead‐free solder for advanced microelectronics packaging.
Design/methodology/approach
Of the 91 journal papers, 59 were published in 2005‐2007 and topics related to wire bonding, flip chip and lead‐free solder for advanced microelectronics packaging are reviewed.
Findings
Research on advanced wire bonding is continuously performed for advanced and complex applications such as stacked‐dies wire bonding, wire bonding of low‐k ultra‐fine‐pitch devices, and copper wire bonding. Owing to its many advantages, flip chip using adhesive has gained more popularity. Research on the reliability of lead‐free solder joints is being conducted world‐wide. The new challenges, solutions and new developments are discussed in this paper.
Research limitations/implications
Because of page limitation of this review paper and the large number of the journal papers available, only a brief review is conducted. Further reading is needed for more details.
Originality/value
This review paper attempts to provide introduction to recent developments and the trends in terms of the topics for advanced microelectronics packaging. With the references provided, readers may explore more deeply, focusing on a particular issue.
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Jun Huang, Haijie Mo and Tianshu Zhang
This paper takes the Shanghai-Shenzhen-Hong Kong Stock Connect as a quasi-natural experiment and investigates the impact of capital market liberalization on the corporate debt…
Abstract
Purpose
This paper takes the Shanghai-Shenzhen-Hong Kong Stock Connect as a quasi-natural experiment and investigates the impact of capital market liberalization on the corporate debt maturity structure. It also aims to provide some policy implications for corporate debt financing and further liberalization of the capital market in China.
Design/methodology/approach
Employing the exogenous event of Shanghai-Shenzhen-Hong Kong Stock Connect and using the data of Chinese A-share firms from 2010 to 2020, this study constructs a difference-in-differences model to examine the relationship between capital market liberalization and corporate debt maturity structure. To validate the results, this study performed several robustness tests, including the parallel test, the placebo test, the Heckman two-stage regression and the propensity score matching.
Findings
This paper finds that capital market liberalization has significantly increased the proportion of long-term debt of target firms. Further analyses suggest that the impact of capital market liberalization on the debt maturity structure is more pronounced for firms with lower management ownership and non-Big 4 audit. Channel tests show that capital market liberalization improves firms’ information environment and curbs self-interested management behavior.
Originality/value
This research provides empirical evidence for the consequences of capital market liberalization and enriches the literature on the determinants of corporate debt maturity structure. Further this study makes a reference for regulators and financial institutions to improve corporate financing through the governance role of capital market liberalization.
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Z.W. Zhong and Y. Jiang
When engineers choose and arrange proper lighting sources for an inspection system, many of them rely on their own experience or guesswork without any guidance of theories. This…
Abstract
When engineers choose and arrange proper lighting sources for an inspection system, many of them rely on their own experience or guesswork without any guidance of theories. This paper discusses the efficient perception technique, i.e. the Torrance‐Sparrow model and its application to the selection and configuration of light emitting diode (LED) lighting sources for a package visual inspection system. Inspection of several typical package samples has been evaluated. The image changes of the sample packages are explained using the Torrance‐Sparrow model. The experimental results with the actual gray level values of the images are compared.
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Preeti Singh, Ruchika Kulshrestha and Sanjna Vij
Purpose: This study is the complex interplay among corporate social responsibility (CSR), governance, and ethics in the context of tourism management in India. It shows us how…
Abstract
Purpose: This study is the complex interplay among corporate social responsibility (CSR), governance, and ethics in the context of tourism management in India. It shows us how businesses engage in sustainable practices that contribute to social economics tourism.
Methodology: This research takes a multi-face approach, theoretical framework, and practice case study to indicate the relationship based on the CSR corporate governance, and business ethics. The study shows that the real case study in Jaipur and Indore.
Research limitations and implications: Given the limitations of the case study research, such as potential basis and limited generalization, this study is necessary for future empirical investigation to validate and expand upon the findings presented here.
Social implications: The chapter discusses the societal significance of business practices. It promotes greater corporate engagement in addressing social, environmental, and economic challenges by showing the positive impact of CSR initiatives on local communities.
Findings: Through case studies and empirical analysis, this chapter reveals how CSR initiatives can improve corporate governance, promote ethical business practices, and positively impact the local economy and environment. It also shows how important evidence-based decision-making matters.
Originality/value: In India's tourism management context, this chapter comprehensively examines corporate governance, business ethics, and CSR. Its usefulness provides practical insights into the practical ramifications of responsible business practices.
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Lu Zhong, Sun Youchao, Okafor Ekene Gabriel and Wu Haiqiao
Maintenance disassembly that involves separating failed components from an assembly or system plays a vital role in line maintenance of civil aircraft, and it is necessary to have…
Abstract
Purpose
Maintenance disassembly that involves separating failed components from an assembly or system plays a vital role in line maintenance of civil aircraft, and it is necessary to have an effective and optimal sequence planning in order to reduce time and cost in maintenance. The purpose of the paper is to develop a more effective disassembly sequence planning method for maintenance of large equipment including civil aircraft systems.
Design/methodology/approach
The methodology involves the following steps: a component‐fastener graph is built to describe the equipment in terms of classifying components into two categories that are functional components and fasteners; interference matrix is developed to determine the removable component, and a disassembly sequence planning of functional components is proposed based on Dijkstra's algorithm; the disassembly sequence planning including fasteners is presented based on particle swarm optimization.
Findings
An application case, which takes the nose landing gear system of a regional jet as a study object, shows that the disassembly sequence planning method proposed in the paper can reduce the calculation complexity greatly, and its effectiveness is greater than that of a genetic algorithm‐based method, in most situations.
Practical implications
The method proposed herein can acquire the optimal maintenance disassembly sequence, which can reduce the cost and time for maintenance of large equipment.
Originality/value
A novel and effective disassembly sequence planning solution for maintenance of large equipment is presented, which can be applied to the line maintenance of civil aircraft.