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In an integrated circuit (IC) substrate, more fillers, including talcum powder and aluminium hydroxide, are added, which leads to much higher rigidity and hardness compared with a traditional printed circuit board. However, the micro drilling of IC substrates is harder. This paper aims to test the drilling process of IC substrates to improve the drilling process and the micro hole quality.

Substrate drilling by a micro drill with 0.11-mm diameter was used under several drilling conditions. The influence of drilling conditions on the drilling process was observed. Drilling forces, drill wear and micro hole quality were also studied.

The deformation circle around holes, hole location accuracy, bugle hole and burrs were the major defects of micro holes that were observed during the drilling of the substrate. Reducing the drilling force and drill wear was the effective way to improve hole quality.

The technology and manufacturing of IC substrates has been little investigated. Research data on drilling IC substrates is lacking. The micro hole quality directly affects the reliability of IC substrates. Thus, improving the drilling technology of IC substrates is very important.

The purpose of this paper is to research the influence of inflation and delay in payment on the inventory model on Weibull distribution and present a new method of inventory control model for fresh agricultural products.

The previous researches deal with the inventory problems. However, these researches are based on deteriorating industrial products, so that the method for inventory model of agricultural products should be employed. According to agricultural products characteristics, the model assumes that deterioration is defined as fixed and demand is taken as Weibull distribution. An optimal order quantity and the minimum inventory total cost are formulated and solved under inflation and delay in payment.

The minimum inventory total cost and the optimal ordering quantity are convex with the length of the period with positive stock. When the delay period is longer than the length of the period with positive stock, the minimum inventory total cost and the optimal ordering quantity increase with permissible delay in payment increase and decrease with inflation rate increase, changing steeply with inflation rate and increasing permissible delay.

The market demand of fresh agricultural products is on two‐parameter Weibull distribution.

The paper gives useful advice for agricultural supply chain managers.

The paper presents a new method of inventory control for fresh agricultural products.

High-ductility cementitious composites (HDCC) have an excellent crack controlled capacity and corrosion resistance capacity, which has a promising application in structure engineering under harsh environment. The purpose of this study is to explore the corrosion mechanism of steel bar in HDCC.

Intact and the pre-cracked HDCC specimens under the coupled action of different dry–wet cycles and chloride attack were designed, and intact normal concrete (NC) was also considered for comparison. Corrosion behavior of a steel bar embedded in HDCC was analyzed by an electrochemical method, a chloride permeability test and X-ray computed tomography.

Steel corrosion probability is related to the chloride permeability of the HDCC cover, and the chloride permeability resistance of HDCC is better than that of NC. Besides, crack is the key factor affecting the corrosion of steel bars, and the HDCC with narrower cracks have a lower corrosion rate. Slight pitting occurs at the crack tips. In addition, the self-healing products and corrosion products fill up the cracks in HDCC, preventing the external aggressive ions from entering and thereby decreasing the steel corrosion rate.

HDCC has a superior corrosion resistance than that of NC, effects of variable crack width on corrosion behavior of steel bar in HDCC under the coupled actions of different dry–wet cycles and chloride attack are investigated, which can provide the guide for the design application of HDCC material in structure engineering exposed to marine environment.

This paper aims to investigate the effects of inhomogeneities on the rolling contact fatigue (RCF) life in elastohydrodynamically lubricated (EHL) point contacts.

A numerical model for predicting the RCF life of inhomogeneous materials in EHL contacts was established by combining the EHL model and the inclusion model through the eigen-displacement and then connecting to the RCF life model through the subsurface stresses. Effects of the type, size, location and orientation of a single inhomogeneity and the distribution of multiple inhomogeneities on the RCF life were investigated.

The RCF life of a half-space containing manganese sulfide (MnS) inhomogeneity or the mixed inhomogeneity of aluminium oxide (Al₂O₃) and calcium oxide (CaO) was longer than that for the case of Al₂O₃ inhomogeneity. For a single ellipsoidal MnS inhomogeneity, increases of its semi-axis length and decreases of its horizontal distance between the inhomogeneity and the contact center shortened the RCF life. Furthermore, the relationship between the depth of a single MnS inhomogeneity and the RCF life was found. For the half-space containing multiple inhomogeneitites, the RCF life decreased remarkably compared with the homogeneous half-space and showed discreteness.

This paper implements the prediction of the RCF life of inhomogeneous materials under EHL condition.

The purpose of this paper is to construct a prediction model of three-parameter interval grey number based on kernel and double information domains to expand the modeling object of grey prediction model from interval grey number to three-parameter interval grey number.

First, the study decomposes the grey valued interval into upper and lower cells with the “center of gravity” as the dividing point and defines the upper and lower information domains of the three-parameter interval grey number. Second, it calculates the kernel, the upper and lower information domains of the three-parameter interval grey number. Then, it constructs the prediction model for kernel sequence and upper and lower information domain sequences, respectively. By deducing the time response expressions of “center of gravity”, lower and upper limits of three-parameter interval grey number, a prediction model of three-parameter interval grey number based on kernel and double information domains is obtained.

This paper provides a prediction model of three-parameter interval grey number based on kernel and double information domains, and the example analysis shows that the method proposed in this paper has higher prediction accuracy and practicality.

In this paper, the modeling object of grey prediction model is extended to the three-parameter interval grey number, so it can be used for the prediction of uncertainty problems, such as stock changing trend, temperature and so on.

By decomposing the grey valued interval into upper and lower cells with the “center of gravity” as the dividing point, gives the definition of upper and lower information domains and then obtains a new method for whitening the three-parameter interval grey number.

As a high-reward strategy to differentiate social platforms, value co-creation is increasingly becoming a tool to enhance customers' social attachment. However, there is still a lack of academic understanding of the value co-creation that enables users to build social attachment with social platforms. To address this challenge, we develop and then examine a theoretical model grounded in value co-creation theory considering the relationship between value co-creation and social attachment, and also explore the mediating effect of user experience and the moderating effect of self-disclosure.

This study takes representative social platform users as the research object, chooses Questionnaire Star as the platform for questionnaire distribution and collection and collects 531 eligible data through the snowball sampling questionnaire method. And then, MPLUS7.4 is used to analyze the data and thus examine our proposed theoretical model.

The results of structural equation modeling analysis suggest that two dimensions of value co-creation (i.e. initiated value co-creation and spontaneous value co-creation) affect social attachment not only directly but also indirectly (i.e. the mediating role of user experience) and that self-disclosure moderates the impact of value co-creation affecting social attachment.

This study verifies the impact of different dimensions of value co-creation toward social platforms on social attachment, showing that value co-creation plays an important role in developing users' social attachment and provides practical implications for promoting the sustainable development of social platforms and building users' psychological well-being.

This paper mainly aims to deal with the problems of uncertainties including modelling errors, unknown dynamics and disturbances caused by load mutation in control of permanent magnet synchronous motor (PMSM).

This paper proposes an enhanced speed sensorless vector control method based on an active disturbance rejection controller (ADRC) for a PMSM. First, a state space model of the PMSM is obtained for the field orientation control strategy. Second, a sliding mode observer (SMO) based on back electromotive force (EMF) is introduced to replace the encode to estimate the rotor flux position angle and speed. Third, an infinite impulse response (IIR) filter is introduced to eliminate high frequency noise mixed in the output of the sliding mode observer. In addition, a speed control method based on an extended state observer (ESO) is proposed to estimate and compensate for the total disturbances. Finally, an experimental set-up is built to verify the effectiveness and superiority of the proposed ADRC-based control method.

The comparative experimental results show that the proposed speed sensorless control method with the IIR filter can achieve excellent robustness and speed tracking performance for PMSM system.

An enhanced sensorless control method based on active disturbance rejection controller is designed to realize high precision control of the PMSM; the IIR filter is used to attenuate the chattering problem of traditional SMO; this method simplifies the system and saves the total cost due to the speed sensorless technology.

The use of sensorless can reduce costs and be more beneficial to actual industrial application.

The proposed enhanced speed sensorless vector control method based on an ADRC with the IIR filter enriches the control method of PMSM. It can ameliorate system robustness and achieve excellent speed tracking performance.

The purpose of this paper is to construct an unbiased interval grey number prediction model with new information priority for dealing with the jumping errors from difference equation to the differential equation in the prediction model of interval grey number.

First, this study obtains a set of linear equations about the model parameters by taking the minimum error sum of squares between the accumulative sequence and its simulation values as criterion, and solves them on the basis of the Crammer rule. Then, according to the new information priority principle, it selects the last number of the accumulated generation sequence as the initial value and gives the expression of the time response function by the recursive iteration method to establish the interval grey number prediction model.

This paper provides an unbiased interval grey number prediction model with new information priority, and the example analysis shows that the method proposed in this paper has higher prediction precision and practicality.

If there is a better method to whiten the interval grey number, so as to fully tap the grey information contained in it, the accuracy of the model will be higher.

The model proposed in this paper can avoid the error caused by jumping from difference equation to differential equation and make full use of new information. It can be better used in a problem where new information has a great influence on prediction results.

This paper selects the last number of the accumulated generation sequence as the initial value and gives the expression of the time response function by the recursive iteration method. Then, it constructs an unbiased interval grey number prediction model with new information priority.

This paper aims to propose a strategy to analyze management governance in China.

This paper incorporates data on 989 Chinese listed firms over 2006 to 2016. A fixed effects model with panel data and an F-test are applied to exploit the relationship between management ownership and firm performance. A threshold model is introduced to explore the impacts of other governance mechanisms on management governance.

This paper finds an inverted U-shaped relationship between management ownership and firm performance. Furthermore, the threshold model demonstrates that large shareholders strengthen the positive effects of management governance and attenuate its negative effects; board size strengthens the positive effects of management governance but cannot attenuate its negative effects; and independent directors attenuate the negative effects of management governance.

This paper indicates that increasing management ownership could motivate managers to ameliorate the agent’s moral hazard problem which link the firm value premium when management ownership is less than 20.286 per cent. However, equity incentives are very rare in China. Thus, the authors expect that equity incentives will be a common phenomenon in Chinese listed firms.

This paper contributes to corporate governance literature by shedding some light on management ownership to explore the effects of management ownership. Specifically, this paper explores the effects of management ownership on firm performance and the impacts of other governance mechanisms on management governance to shape the management governance in China.