Search results

An emerging body of literature has pinpointed the role of supply chain structure in influencing the extent to which supply chain members disclose information about their internal practices and performance. Nevertheless, empirical research investigating the effects of firm-level relational embeddedness on network-level transparency still lags. Drawing on social network analysis, this research examines the effect of relational embeddedness on supply chain transparency and the contingent role of digitalization in the context of environmental, social and governance (ESG) information disclosure.

In their empirical analysis, the authors collected secondary data from the Bloomberg database about 2,229 firms and 14,007 ties organized in 107 extended supply chains. The authors employed supplier and customer concentration metrics to measure relational embeddedness and performed multiple econometric models to test the hypothesis.

The authors found a positive effect of supplier concentration on supply chain transparency, but the effect of customer concentration was not significant. Additionally, the digitalization of focal firms reinforced the impact of supplier concentration on supply chain transparency.

The study findings contribute by underscoring the critical effect of relational embeddedness on supply chain transparency, extending prior literature on social network analysis, providing compelling evidence for the intersection of digitalization and supply chain management, and drawing important implications for practices.

Harmonic gears always work under different operating conditions and may usually break down due to lubrication failures, while its lubrication mechanism is still not clearly understood. This paper aims to present a lubrication model comprehensively considering the influence of contact geometry, lubrication properties and three-dimensional (3D) real surface roughness to analyze the lubrication performance under different conditions.

Based on the discrete convolution-fast Fourier transformation with duplicated padding and quasi-system numerical methods, the lubrication model for harmonic gears is developed, which is verified by comparing results with available lubrication data.

The effects of meshing process, working conditions and 3D roughness on the lubrication characteristics are discussed. From the calculated cases, the increase in rotational speed and decrease of applied torque may increase the film thickness, enhancing the lubrication performance of harmonic gears. It is also observed that proper surface roughness can be used for lubrication design.

The research results can provide theoretical guidance for improving lubrication performance and reducing friction/wear of the harmonic gear interfaces. This study can be promoted to various engineering scenarios of harmonic gears, such as industrial robots, space-driven agencies and precision measuring instruments.

This paper aims to study whether the adoption of an entry mode that fits the social trust level contributes to the improvement of foreign subsidiary performance.

The authors used the Probit model, linear regression, strategic fit approach and instrumental variable regression. The sample was made up of 11,095 observations of Chinese multinational enterprises' foreign subsidiaries in 54 countries from 2005 to 2020.

The results suggest that a host country with a high level of social trust results in fewer difficulties for enterprises in gaining legitimacy, thus foreign subsidiaries are more likely to select the wholly owned entry mode. The results also show that the effect is contingent on the formal institutions of host countries. The results of the mechanism test suggest that social trust influences subsidiaries' entry mode choice by reducing information asymmetry, costs and uncertainty risks. This study further finds that selecting a fit entry mode based on social trust level substantially increases foreign subsidiary performance and this effect is more significant when multinational enterprises (MNEs) are state-owned enterprises (SOEs).

The main limitation of this paper is its only focus on foreign subsidiaries of Chinese MNEs, which may limit the generalizability of research findings.

This paper responds to the call for conducting more research on informal institutions. Findings highlight the critical role of informal institutions in helping foreign subsidiaries in gaining legitimacy in host countries and the essentialness of selecting a fit entry mode based on the informal institutions of host countries for the development of foreign subsidiaries.

The present study aims, by adopting bibliomining, to analyse the borrowing and collection records in self-service libraries at mass rapid transit stations in northern Taiwan to discover reader borrowing preferences and patterns.

The current study used data mining to analyse two years of book-borrowing information from self-service library stations; it made use of an association rule mining model and the bibliomining process to identify readers’ preferred books and to explore reader borrowing behaviours. In addition, the librarians’ perceptions of the proposed approach were also investigated.

The findings indicated that readers often borrowed books in the bibliographical classifications of Home economics; Medical sciences; Psychology; Commerce: administration and management; and Education in the self-service library stations. Based on the bibliomining results, 23 reader borrowing patterns as well as potential books favoured by readers were uncovered. In addition, the challenges of bibliomining and data mining applied to library operations are reported.

Among the studies on the application of self-service technologies in libraries, most examined the integration of the self-service system and investigated users’ opinions. The present study used borrowing records and collection records in self-service library stations to conduct bibliomining and to explore reader borrowing preferences and behaviours as references for collection development and book recommendation services.

Identification in a regression discontinuity (RD) design hinges on the discontinuity in the probability of treatment when a covariate (assignment variable) exceeds a known threshold. If the assignment variable is measured with error, however, the discontinuity in the relationship between the probability of treatment and the observed mismeasured assignment variable may disappear. Therefore, the presence of measurement error in the assignment variable poses a challenge to treatment effect identification. This chapter provides sufficient conditions to identify the RD treatment effect using the mismeasured assignment variable, the treatment status and the outcome variable. We prove identification separately for discrete and continuous assignment variables and study the properties of various estimation procedures. We illustrate the proposed methods in an empirical application, where we estimate Medicaid takeup and its crowdout effect on private health insurance coverage.

The 3D medical image segmentation is a really difficult problem. The purpose of this paper is to present a novel segmentation method for cases that some regions of interest to be segmented from 3D medical images have strong similarities such as gradient between adjacent slides.

This method brings gradient characteristics of the adjacent‐segmented slide, called interfacial gradient priors, into the slide waiting for segmentation and to help the contour converge to actual boundary more accurately.

This method will improve the stopping criterion of curve evolution through introduction of adjacent slide's prior information into edge detection function, so that the leakage phenomena that exists in geometric active contour model when discontinuous or weak edges appear is reduced.

Introducing adjacent slide's priors improves the precision and stability of geodesic geometric flows in 3D medical image segmentation.

The purpose of this paper is to investigate the laser soldering of fine pitch quad flat package (QFP) devices using lead‐free solders and solder joint reliability during thermal cycling.

QFP devices were selected as the test vehicles and were soldered with four alloy types, Sn37Pb, Sn3.5Ag, Sn3.8Ag0.7Cu and Sn3.8Ag0.7Cu0.03Ce. The experimental samples were QFP‐256 devices with lead‐free solder paste on the printed circuit boards. The packages were dried for 24 h at 125°C prior to reflow soldering. Soldering experiments on the QFP devices were carried out with an infrared (IR) reflow soldering oven and a diode laser (DL) soldering system. Reflow soldering was performed at peak temperatures of 210°C (SnPb), 240°C (SnAgCu and SnAgCuCe) and 250°C (SnAg), as determined on the boards. Pull testing was adopted to evaluate the tensile strength of the four solders using an STR–1000 micro‐joint strength tester.

The tensile force of the QFP micro‐joints increased as laser intensity increased when it was less than an “optimal” value. The maximum tensile force of the QFP micro‐joints was gained when the laser intensity had increased to 2,165, 2,127, 2,165 and 2,064 W/cm², depending on the alloy used. The thermal fatigue performance of three lead‐free solder joints, SnAgCuCe, SnAgCu and SnAg, was determined to be superior to that of the eutectic SnPb alloy. After soldering without thermal cycling tests, the fracture morphology of soldered joints exhibited characteristic toughness fracture with both of the soldering methods. After 700 thermal cycles, the fracture mechanism was also toughness fracture, nevertheless, the dimples became large. The fracture morphology of the soldered joints subjected to 1,500 thermal cycles indicated brittle intergranular fracture on the fracture surface and no intense plastic deformation appeared before fracture with IR soldering. For DL soldering, the pull fracture model of the SnAgCuCe was completely ductile in the soldered joint with 1,500 thermal cycles.

The paper usefully investigates the influence of laser intensity on the tensile strength of different soldered joints and the solder joint reliability during thermal cycling.

The purpose of this paper is to analyze the frame of a missile formation cooperative control system, and present an optimal keeping controller of a missile formation in the cooperative engagement.

A missile relative motion model is established directly based on the kinematics relationships in the relative coordinated frame, following that is the detailed process of designing an optimal formation controller, which is analyzed through the small disturbance linearized method and transforming control variables method, respectively, these two methods both have themselves properties. The equations and control variables are intuitive during the linearized analysis, but errors brought by the linearized method are unavoidable, which will reduce the control precision. As for the transforming method, the control accuracy is greatly increased although the control form is a little complex, so in this paper the transforming control variable method is mainly researched to design an optimal formation controller. Considering the states of a leader as input perturbation variables, we design an optimal formation controller based on the linear quadric theory, which has quadric optimal performances of the missile flight states and control quantity. In order to obtain a higher accurate solution, the precise integration algorithm is introduced to solve the Riccati Equation that significantly affects the accuracy of an optimal control problem.

The relative motion model established directly in the relative coordinate frame has intuitive physical significance, and the optimal controller based on this relative motion model is capable of restraining the invariable or slowly varying perturbation brought by the velocity of a leader and the input perturbations caused by the maneuver of the leader, at the same time this optimal controller can implement formation reconfiguration and keeping to an expected states rapidly, steadily and exactly; the steady errors can be greatly decreased by analyzing the relative motion model through transforming control variables method compared to the small disturbance linearized operation.

The main frame of a missile formation cooperative engagement system can be found in this paper, which shows a clear structure and relations of each part of this complex system. The relations between each subsystem including the specific input and output variables can also be used to guide and restrict how to design each subsystem. The emphasis of this paper is on designing an optimal formation keeping controller which can overcome slowly varying or invariable perturbations and implement quadric optimal keeping control rapidly, stably and accurately.

This paper provides a new method to analyze the missile relative motion model. The proposed proportional and integral (PI) optimal controller based on this model, and utilizing the Precise Integration Algorithm to solve this optimal controller are also new thoughts for formation control problems.