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This paper aims to analyze their generation mechanism and factors influencing burr generation. The final goal is to use appropriate drill design and drilling process to control the generation of burrs.

The mechanism of burr generation was studied through finite element method (FEM) simulation and drilling experiments. High-speed photography technology and scanning electron microscope (SEM) were used in this study.

High-speed drilling burr is a printed circuit board (PCB) copper foil burr. Within a certain range, the feed speed and burr height is in positive correlation, and decrease in the feeding speed will favor the exit burr. Drill angle influences burr and chisel edge affect significantly, followed by the point angle, and helical angle has little effect. From the perspective of reducing the burr, a smaller chisel edge and smaller point angle should be chosen. Grinding chisel edge is another choice to decrease the burr but also ensures the blade strength.

This paper investigates the mechanism of burr generation of PCB fixture hole drilling. The process of burr generation was captured by high-speed camera. The controlling methods of burr generation were illustrated at the end.

The purpose of this paper is to investigate the cutting mechanism of drilling printed circuit board (PCB) and to optimize the drilling parameters for decreasing burr size and thrust force.

An experimental study was carried out to investigate the effect of drilling parameters on thrust force and burr formation. The drilling process of PCB was divided by the variation of drilling force signals. Analysis of variance (ANVONA) was carried out for burr size and thrust force. Desirability function method was used in multiple response optimization, to find the best drilling parameters.

Enter burr and exit burr have different morphologies and types. The generation of enter burr is mainly caused by burr bending which can be observed in micrographs, whereas the generation of exit burr is more complicated than enter burr; both burr breakup and burr bending are observed in exit burrs. In the selected area, the optimized spindle speed and feed rate for drilling PCB is 12 krev/min and 6 mm/s, respectively.

In this paper, hole wall roughness and tool wear were not considered in the optimization of drilling parameters. The future research work should consider them.

This paper investigates the mechanism of burr formation and thrust force in drilling PCB and then optimizes the drilling parameters to decrease the burr formation and thrust force.

The flexible printed circuit (FPC) board with the characteristic of light and thin strengthened confronted the growing miniaturization requirements of the electronic product and the popularity of wearable devices. The reliability of circuit could be influenced by the hole quality of FPC, such as burrs, which is one of the major problem in FPC.

In this paper, micro-drill with a diameter of 0.1 mm was used to drill the double-sided flexible copper clad laminate. The thrust force, the burr and tool wear were investigated. The influencing factors of the height of the burrs were studied. The relationship between the thrust force and the height of the burrs was also explored. Finally, the formation mechanism of burrs was analyzed.

The entrance burrs were usually less than the exit burrs. The burr height increased with the feed per rotation. The height of the burr increased with the increase of the thrust force for the plastic deformation of the copper foil was dominant. The abrasion of the drill gave rise to increase the height of burr. In micro-hole drilling, the growth of burrs can be suppressed effectively by reducing the clearance between the FPC and the backup plate. The thrust force would be controlled in a certain range to reduce the burr with specific drilling parameters. There existed a certain relationship of Gaussian distribution between the height of the burrs and the thrust force of FPC.

The reliability of the integrated circuit was directly affected by the burrs of the FPC. This research on the formation mechanism of FPC burrs and forecast of burr height provided a firm foundation for further work in the area of improvement of the micro-hole quality.

The purpose of this paper is to develop a cost model by the variable sampling interval and optimization of the average cost per unit of time. The paper considers an economic–statistical design of the X̅ control charts under the Burr shock model and multiple assignable causes were considered and compared with three types of prior distribution for the mean shift parameter.

The design of the modified X̅ chart is based on the two new concepts of adjusted average time to signal and average number of false alarms for X̅ control chart under Burr XII shock model with multiple assignable causes.

The cost model was examined through a numerical example, with the same cost and time parameters, so the optimal of design parameters were obtained under uniform and non-uniform sampling schemes. Furthermore, a sensitivity analysis was conducted in a way that the variability of loss cost and design parameters was evaluated supporting the changes of cost, time and Burr XII distribution parameters.

The economic–statistical model scheme of X̅ chart was developed for the Burr XII distributed with multiple assignable causes. The correlated data are among the assumptions to be examined. Moreover, the optimal schemes for the economic-statistic chart can be expanded for correlated observation and continuous process.

The economic–statistical design of control charts depends on the process shock model distribution and due to difficulties from both theoretical and practical aspects; one of the proper alternatives may be the Burr XII distribution which is quite flexible. Yet, in Burr distribution context, only one assignable cause model was considered where more realistic approach may be to consider multiple assignable causes.

This study presents an advanced theoretical model for cost model that improved the shock model that presented in the literature. The study obviously indicates important evidence to justify the implementation of cost models in a real-life industry.

The quality level setting problem determines the optimal process mean, standard deviation and specification limits of product/process characteristic to minimize the expected total cost associated with products. Traditionally, it is assumed that the product/process characteristic is normally distributed. However, this may not be true. This paper aims to explore the quality level setting problem when the probability distribution of the process characteristic deviates from normality.

Burr developed a density function that can represent a wide range of normal and non-normal distributions. This can be applied to investigate the effect of non-normality on the studies of statistical quality control, for example, designs of control charts and sampling plans. The quality level setting problem is examined by introducing Burr’s density function as the underlying probability distribution of product/process characteristic such that the effect of non-normality to the determination of optimal process mean, standard deviation and specification limits of product/process characteristic can be studied. The expected total cost associated with products includes the quality loss of conforming products, the rework cost of non-conforming products and the scrap cost of non-conforming products.

Numerical results show that the expected total cost associated with products is significantly influenced by the parameter of Burr’s density function, the target value of product/process characteristic, quality loss coefficient, unit rework cost and unit scrap cost.

The major assumption of the proposed model is that the lower specification limit must be positive for practical applications, which definitely affects the space of feasible solution for the different combinations of process mean and standard deviation.

The proposed model can provide industry/business application for promoting the product/service quality assurance for the customer.

The authors adopt the Burr distribution to determine the optimum process mean, standard deviation and specification limits under non-normality. To the best of their knowledge, this is a new method for determining the optimum process and product policy, and it can be widely applied.

The purpose of this research paper is to discuss a software reliability growth model (SRGM) based on the non‐homogeneous Poisson process which incorporates the Burr type X testing‐effort function (TEF), and to determine the optimal release‐time based on cost‐reliability criteria.

It is shown that the Burr type X TEF can be expressed as a software development/testing‐effort consumption curve. Weighted least squares estimation method is proposed to estimate the TEF parameters. The SRGM parameters are estimated by the maximum likelihood estimation method. The standard errors and confidence intervals of SRGM parameters are also obtained. Furthermore, the optimal release‐time determination based on cost‐reliability criteria has been discussed within the framework.

The performance of the proposed SRGM is demonstrated by using actual data sets from three software projects. Results are compared with other traditional SRGMs to show that the proposed model has a fairly better prediction capability and that the Burr type X TEF is suitable for incorporating into software reliability modelling. Results also reveal that the SRGM with Burr type X TEF can estimate the number of initial faults better than that of other traditional SRGMs.

The paper presents the estimation method with equal weight. Future research may include extending the present study to unequal weight.

The new SRGM may be useful in detecting more faults that are difficult to find during regular testing, and in assisting software engineers to improve their software development process.

The incorporated TEF is flexible and can be used to describe the actual expenditure patterns more faithfully during software development.

This paper aims to develop a novel type of bionic underwater robot (BUR) with multi-flexible caudal fins. With the coordinate movement of multi-caudal fins, BUR will combine the undulation propulsion mode of carangiform fish and jet propulsion mode of jellyfish together organically. The use of Computational Fluid Dynamics (CFD) and experimental method helps to reveal the effect of caudal fin stiffness and motion parameters on its hydrodynamic forces.

First, the prototype of BUR was given by mimicking the shape and propulsion mechanism of both carangiform fish and jellyfish. Besides, the kinematics models in both undulation and jet propulsion modes were established. Then, the effects of caudal fin stiffness on its hydrodynamic forces were investigated based on the CFD method. Finally, an experimental set-up was developed to test and verify the effects of the caudal fin stiffness on its hydrodynamic forces under different caudal fin actuation frequency and amplitude.

The results of this paper demonstrate that BUR with multi-flexible caudal fins combines the hydrodynamic characteristics of undulation and jet propulsion modes. In addition, the caudal fin with medium stiffness can generate larger thrust force and reduce the reactive power.

This paper implies that robotic fish can be equipped with both undulation and jet propulsion modes to optimize the swimming performance in the future.

This paper provides a BUR with multi-propulsion modes, which has the merits of high propulsion efficiency, high acceleration performance and overcome the head shaken problem effectively.

The purpose of this paper is to evaluate the performance of cutting fluid applied by minimum quantity technique when milling AISI 4140 steel with TiAlN coated cemented carbide inserts.

The vegetable oil based cutting fluid evaluated was applied through a nozzle at the centre of the tool holder under vaporized conditions with a flow rate between 0 (dry cutting) and 200 ml/h, at 50 ml/h increments. Tool wear (based on maximum flank wear, VB_max), surface roughness parameters (R_a and R_t) and burr formation (length of burr, h) were recorded and evaluated. Scanning electron microscope images and energy dispersive X‐ray analysis of the worn tools show adhesion as the dominant wear mechanism.

Encouraging tool performance was recorded when milling AISI 4140 steel due to improved lubrication and cooling at the cutting interfaces. Increase in cutting fluid flow rate improves tool life with gradual reduction of the surface roughness parameters and negligible influence on the burr length generated.

Results can be immediately applied on the shop floor.

The results show the improvement in tool wear after increase of the flow rate of the cutting fluid, applied by minimum quantity technique.

The purpose of this paper is to demonstrate that an implication of Holcombe’s (2002) model is a “revolution trap.” This paper extends Holcombe’s model adding Klein’s concept of entrepreneurship as judgment concerning the use of heterogeneous political capital. The authors use the case of the USA presidential election of 1800 to demonstrate the utility of the extension, and to discuss how political entrepreneurship served to prevent a revolution trap. The political entrepreneurship of 1800 established the precedent of peaceful transition of power in the USA, which opened the door to the rapid economic development of the early nineteenth century.

This is a historical case study using letters, newspapers, pamphlets, and other pieces of empirical evidence to highlight an important moment of political entrepreneurship.

Many contemporary observers predicted that the USA would devolve into continuous revolution, which the authors argue Holcombe’s (2002) model predicts. However, political entrepreneurship ended the revolutionary period in the former British North America. Moreover, the political entrepreneurship ending the election crisis established the precedent of peaceful political succession. This precedent comparatively elevated the returns of productive, market entrepreneurship (Baumol, 1990). As a result, the USA experiences a prolonged period of entrepreneurially driven economic growth.

To the authors knowledge, no one has developed the implication of a “revolution trap” from Holcombe’s (2002) model, nor has anyone applied Klein’s (2008) model to extend Holcombe’s model of political entrepreneurship. Although the disputed presidential election of 1800 has been extensively researched, no one has analyzed the election and its resolution from the perspective of political entrepreneurship.

This paper describes the development of a variety of robot welding and grinding systems. Also discusses the benefits of running arc welding cables within the body of the robot and the use of a computer controlled welder. Also covers digitally controlled spot welding and communication with a supervisory computer. Finally, discusses de‐burring and the opportunities for further development in this area.