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Integration of Cu/low‐k interconnects into the next‐generation integrated circuit chips, particularly for devices below the 90 nm technology node, has proved necessary to meet the urgent requirements of reducing RC time delay and low power consumption. Accordingly, establishment of feasible and robust packaging technology solutions in relation to the structural design, as well as material selection of the packaging components, has become increasingly important. Moreover, the nature of low‐k materials and the use of lead‐free solder greatly increases the complications in terms of ensuring enhanced packaging level reliability. The foregoing urgent issue needs to be quickly resolved while developing various advanced packages. This paper aims to focus on the issues.

The prediction model, especially for the fatigue life of lead‐free solder joints, combined with virtual design of experiment with factorial analysis was used to obtain the sensitivity information of selecting geometry/material parameters in the proposed low‐k flip‐chip (FC) package. Moreover, a three‐dimensional non‐linear strip finite element model associated with the two levels of specified boundary condition of global‐local technique was adopted to shorten the time of numerical calculation, as well as to give a highly accurate solution.

The results of thermal cycling in experimental testing show good agreement with the simulated analysis. In addition, the sensitivity of analysis indicates that the type of underfill material has a significant effect on the lead‐free solder joint reliability.

A suitable combination of concerned designed factors is suggested in this research to enhance the reliability of low‐k FC packaging with Pb‐free solder joints.

This study aims to investigate the spectral illumination characteristics and geometric features of bicycle parts and proposes an image stitching method for their automatic visual inspection.

The unrealistic color casts of feature inspection is removed using white balance for global adjustment. The scale-invariant feature transforms (SIFT) is used to extract and detect the image features of image stitching. The Hough transform is used to detect the parameters of a circle for roundness of bicycle parts.

Results showed that maximum errors of 0°, 10°, 20°, 30°, 40° and 50° for the spectral illumination of white light light-emitting diode arrays with differential shift displacements are 4.4, 4.2, 7.8, 6.8, 8.1 and 3.5 per cent, respectively. The deviation error of image stitching for the stem accessory in x and y coordinates are 2 pixels. The SIFT and RANSAC enable to transform the stem image into local feature coordinates that are invariant to the illumination change.

This study can be applied to many fields of modern industrial manufacturing and provide useful information for automatic inspection and image stitching.

The purpose of this study is to analyse and explore the characteristics of patent–paper pairs (PPPs) in the field of fuel cells.

The authors used bibliometric analysis to analyse the bibliometric records of PPPs identified from 20,758 papers and 8,112 utility patents between 1991 and 2010.

The findings show that the percentages of papers and patents constituting PPPs were low, but an increasing trend was identified in the absolute number of PPPs. Researchers affiliated with research institutions were the primary contributors to PPPs. Countries with the most papers and patents had the most PPPs, exploiting the advantage of dual knowledge creation. Similar growth trends were observed in the numbers of patents approved and papers published. Patents in PPPs were typically produced earlier than the papers in PPPs. On average, patents were applied for approximately four years before papers were published, and patents were approved only approximately four months before papers were published.

While the study was limited to the PPPs in the field of fuel cells, PPPs analysis can be applied to numerous fields.

PPPs indicate the coactivity of researchers involved in publishing and patenting. Although this coactivity has been studied, few studies have investigated PPPs. This study helps us better understand the characteristics of papers and patents constituting PPPs, changes in the annual numbers of papers and patents constituting PPPs, delays between papers and patents, as well as individuals, institutions and countries producing numerous PPPs.

Deep excavation in soft clay often causes additional deformations to surroundings. Then, if deformations cannot be predicted reasonably, the adjacent buildings may be threatened by the deep excavation. Based on the good field observations from ten deep excavations in Hangzhou, this paper aims to thoroughly investigate the characteristics of wall deflections and ground settlements induced by deep excavations.

On the basis of good field observation of ten deep excavations, the performances of excavations, supported by contiguous pile in Hangzhou, were studied, and also compared with other case histories.

The maximum wall deflections (dhm) rang mostly from 0.7 to 1.2 per cent H_e, where He is the final excavation depth, larger than those in Taipei and Shanghai. The observed maximum ground settlement in the Hangzhou cases generally ranges from 0.2 to 0.8 per cent H_e. Then, the settlement influence zone extends to a distance of 2.0-4.0 H_e from the excavation. The relatively large movements and influence zones in Hangzhou may be attributed to low stability numbers, large excavation widths and the creep effect. The excavation width is justified to have a significant influence on the wall deflection. Therefore, to establish a semi-empirical formula for predicting the maximum wall deflection, it is necessary to include the factor of excavation width.

The relevant literature concentrated on the characteristics of deep excavations supported by the contiguous pile wall in Hangzhou soft clay can rarely be found. Based on the ten deep excavations with good field observation in Hangzhou, the characteristics of wall deflection and ground settlements were comprehensively studied for the first time, which can provide some theoretical support for similar projects.

The purpose of this paper is to study the influences of both the number and locations of entry holes on the static and dynamic characteristics of a rigid rotor supported by two double‐rows, inherently compensated aerostatic bearings.

The air is assumed to be perfect gas undergoing the adiabatic process and passing through entry holes into the bearing clearance. Air film in the clearance is governed by Reynolds equation including the coupled effects of wedge due to rotor rotation and squeezed film due to rotor oscillation.

The method is used to analyze Reynolds equation, which is then solved by the finite difference method and numerical integration to yield static and dynamic characteristics of air film. The equation of motion of the rotor‐bearing system is obtained by using the perturbation method and the eigensolution method is used to determine the stability threshold and critical whirl ratio.

The paper considers the eccentricity, rotor speed, and restriction parameter in the analysis of the whirl instability of the rotor‐aerostatic bearing system for the comparisons between various designs in the number and locations of entry holes of aerostatic bearings.

This study investigates the impacts of operational risks and corporate governance on bond yield spreads, examining their impacts on bond yield spreads during the COVID-19 pandemic. The results indicate that operational risks significantly raise yield spreads, especially for high-leverage firms. Moreover, a higher independent director percentage reduces debt costs. Furthermore, the results reveal more pronounced effects of operational risks on yield spreads during the COVID-19 pandemic, with these risks increasing the financing costs for large firms. When the effect of the independent director percentage on the yield spreads increases, this consequently raises the debt costs for large firms.

The purpose of this paper is to find the relationship of palaeontology, palaeobotany and coal thickness of Taiyuan Formation during Late Carboniferous – Early Permian Period in Shanxi Province.

This paper selects three regions, namely, Baode, Xishan and Lingchuan, to analyse the distribution characteristics of palaeontology, palaeobotany and variation of coal thickness.

It was found that in a certain period of geological history, palaeontology and palaeobotany play a dominant role in shaping of a coal-bearing basin. Coal seam thickness changes largely from the northwest to the southeast, gradually thinning in Taiyuan Formation.

Palaeontology and palaeobotany play a dominant role in the shaping of a coal-bearing basin.

This paper is the third part of a serial studies for constant and variable compensations of the closed-type hydrostatic thrust bearings which has face-to-face recesses couple. The static stiffness of closed-type hydrostatic thrust bearings can then be obtained from the differentiation of recess pressure with respect to worktable displacement. The paper aims to discuss these issues.

In this paper, the double-action restrictors of cylindrical-spool-type and tapered-spool-type are taken into consideration for variable compensation of hydrostatic bearings.

The static stiffness in thrust direction of hydrostatic bearing is determined by the flow continuity equations that are formulated by film flow and compensation flow for each recess, respectively. The type selection and parameter determination of the double-action spool-type restrictors can be obtained from finding results of this study for maximum stiffness in design of hydrostatic bearings.

This study reveals that the appropriate range of recess pressure ratio and design parameters of restrictors for the maximum stiffness can be obtained, the avoidance of negative stiffness is also provided.

The purpose of this study is to examine the impact of board diversity (e.g. nationality, gender and educational level) on financial performance for a sample of banks listed in 11 countries in the Middle East and North Africa region.

This paper uses the system generalized method of moments estimation approach on the data of banks listed in the MENA countries over the period 2011–2018 to investigate the relationship between board diversity and financial performance. Also, the findings are supported by additional robustness tests, including ordinary least squares, fixed and random effect techniques.

The empirical results show that there is a significant relationship between board diversity and financial performance in banks. Specifically, the findings demonstrate that board diversity related to nationality has a significant positive impact on bank performance. The findings also show an insignificant association between gender and educational level diversity and bank performance. The robustness analysis supports the findings of the baseline model.

The study provides multi-country evidence on the importance of board diversity in the MENA region and it sheds light on possible tracks for future reforms aimed at enhancing the effectiveness of the board’s functions.

This paper extends the existing literature by providing empirical evidence on the association between board diversity and financial performance of banks in the MENA countries. This paper also provides preliminary evidence on the importance of board diversity to influence financial performance.