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This study employed the Taguchi method, analysis of variance, and response surface methodology for plastic gear rack injection molding parameters followed by a factorial quality validation. This study was expected to reduce the time cost of mold design and injection molding by making different combinations of the molding parameters, designing an experimental method, and performing the data simulation experiment by computer-aided engineering (CAE). With the research tool of polymer (polyacetal) for plastic material, computer-aided design mold design, and CAE mold flow analysis software, a numerical analysis of plastic molding flow was conducted. Taguchi L16 (45) orthogonal array designed 16 experimental combinations including injection molding conditions of filling time, holding pressure, holding time, plastic temperature, and mold temperature. The experimental results of molding analysis of software (Moldex3D) determined the optimum molding essentials of plastic injection: filling time 0.2 s, holding pressure 98 MPa, plastic temperature 195 °C, and mold temperature 65 °C. In this study, the parameters of the response surface method were used for the actual injection verification. The CAE simulation software can greatly improve the mold design and injection molding parameter testing time to enhance the overall working efficiency and cost control.

In the context of school learning and teaching, teachers are leaders who stimulate students’ learning outcomes through leadership styles. The teacher efficacy of this study is discussed by using multiple teaching and class management strategies. Because the situation of each school is different, the contingency theory is used to design the research structure. This study changed the original leadership style to the new leadership style; effectiveness to teacher effectiveness; and context to school context, and set them as moderators. Since the unit of analysis is teachers, it is difficult to find factors such as differences in regression coefficients in the school context. Therefore, the HLM hierarchical linear analysis is used, and the school context is set as the second level, and then statistical analysis is performed. Teachers’ leadership styles have significant differences in multiple teaching strategies for teacher effectiveness. Moral leadership and charismatic leadership have a moderating effect on the multiple teaching strategies of teacher effectiveness. The multiple teaching strategies of teacher effectiveness have a significant effect in middle school situations with lower moral leadership. On the other hand, charismatic leadership is more pronounced in middle school situations than in high school situations. Teachers’ leadership styles have a significant impact on classroom management of teacher effectiveness. Under the situational control of schools, moral leadership, charismatic leadership, and supportive leadership have moderating effects on classroom management of teacher effectiveness. When the classroom management of teacher effectiveness is in the middle school situation, low moral leadership is more significant; in the high school situation, charismatic leadership will reduce the effectiveness of the class management; in the moderate or high situation, the higher the support of the leader, the greater the effect of class management.

With the advancement of technology, plastic products are inseparable in our environment, and the impact of the plastics industry on us is gradually increasing. Although Taiwan's plastics industry has been progressively added to mold flow analysis and automation, there are still some areas in the manufacturing process that can be optimized. In the process of slit-shaped materials, bending and deformation have a very large impact on the finished product, which is a major issue at the technical level. In this study, a toothbrush was taken as an example to find the best combination of injection molding parameters. The research process was studied from CAD mold design, CAE mold flow analysis, injection molding parameter analysis, mold opening, product injection and measurement, and the results were verified. Among them, the injection pressure, dwell time and holding pressure are used as the Taguchi factor, and the CAE mold flow analysis is performed by the direct cross table L16 (45) combination to find a small amount of warpage, and the Taguchi method and the reaction surface method are used to find out the best combination of parameters. After the final product was shot and the dimensions and simulation were compared with each other, the data showed that the amount of warpage of the finished product was 0.0892 mm, and the error with the analog value was 0.0212 mm, which confirmed that the injection molding parameters were reliable.

This study explores the multi-stage cold forming die of a welding valve fastener using simulation software. It is possible to understand the various stress intensities of the die core bore and the corresponding distributions during each forging stage so as to improve the service life of the die. These stresses include radial stress, axial stress, hoop stress, and maximum principal stress, as well as the different types of stresses that could cause different fractures of the die core. Therefore, it is necessary to use different die design methods to improve the fracture issues for different die cores. For example, shrink fit can be used between the die core and die case. By adjusting the size of the shrink fit, tensile hoop stress can be converted into compressive hoop stress, which can avoid the generation of axial cracking of the die during the forging formation. In addition, drastic changes in axial stress caused by the stress concentration on the die core can yield a transverse crack of the die core. Thus adopting preventative measures by split such a stress concentration into two sections reduces the drastic changes in axial stress on that section.

This study identified the competency requirement for artificial intelligence in finite element analysis. The 10 Delphi group members included 5 field engineers in mechanical fields and 5 scholars f...

The machine tool industry is an economically important industry in Taiwan. However, due to the limited natural resources in Taiwan, many of the raw materials required for production must be imported. In 2020, COVID-19, the most serious infectious disease in modern times, broke out across the globe. This has had a great impact on the economic and industrial development of various countries and indirectly affected the development of the machine tool industry. The machine tool industry generally is facing shocks and crises. Therefore, this research article mainly discusses a sustainable operation strategy for the machine tool industry during the COVID-19 epidemic period in Taiwan. Firstly, through the literature on dynamic capability theory (DCT) and expert interviews, the relevant dimensions and criteria are summarized. Then, the fuzzy Delphi method (FDM) and the analytic network process (ANP) are integrated to confirm the relevant dimensions and criteria and to sort the criteria. The five dimensions, in order, are integration ability, learning ability, quality improvement, environmental adaptation, and marketing ability. The ten criteria are diversified learning and innovation ability, integration of multiple sources of knowledge, the ability to learn across departments, the ability to adapt to the external environment, marketing strategy ability, organizational learning ability, integration of resources, improved management efficiency, market research ability, and backward integration. Finally, we put forward business strategies for the ranking results and provide relevant research and industry references.

The object of this study was the optimization of dressing parameters used with rotary diamond dressers. A grinding wheel was dressed using different dressing factors and levels and the resu...

This study conducts an experimental investigation into the bending behavior and electrical resistance properties of Flex (PI with Cu)-On-Film (ITO–coated PET) packages considering the flexible effects under static bending loads with sequential bending cycles. The FOF packages, consisting of flex (with fine-pitch Cu circuits) and film (ITO–coated PET plastic) are bonded by Anisotropic Conductive Film (ACF). During the ACF bonding process, the deformed conductive particles in the adhesive matrix between the Cu electrodes and the ITO film under the effects of the compression force, and these broken conductive particles will play an electrical conductive role. In the subsequent bending tests (loading &unloading with many cycles), the conductive particles experience a compression or tension stress, which causes a further propagation of the cracks formed in the original packaging process. The results show the measured electrical resistance in the specified conductive channel increases with the bending cycles increasing, and the microscopic observations show that the higher electrical resistance is the result of a smaller overall contact area between the conductive ACF particles and the Cu electrode/ITO film due to fatigue crumbling of the particles.

This study employed different molding parameter combinations, the Taguchi method, ANOVA, and response surface methodology to perform experiments. Finite element analysis was executed to find the optimum molding parameters and increase the depth of drawing molding. The material is aluminum alloy 6016, and the servo press was adopted for the experiments. The factors influencing the drawing molding including punch fillet radius, die fillet radius, die clearance, molding curve, and mold temperature were determined. To find the optimum combination of parameters and to design 16 experimental combinations, the L16 orthogonal array of the Taguchi method was employed. According to the experimental results, the optimum parameters include punch fillet radius of 8.5 mm, die fillet radius of 8.5 mm, clearance of 1.5 t, curve 3, and the mold temperature of 20°C. Using the optimum parameter combination the molding depth could be increased greatly and the thickness ratio could be improved.

The machine industry has undergone several developments in the past years, and reducing the cost and time required for machine designing is important. In this study, the vibration characteristics of a precision grinding machine were obtained through experimental modal analysis and finite element analysis. The experimental modal analysis employed single point excitation, and the equipment used to determine the frequency response of the grinding machine comprised a hammer, an accelerometer, and a spectrum analyzer. In addition, the resonance frequency, damping factor, and modal shape of the grinding machine were determined. The natural frequency, modal shape, and interface stiffness were determined through finite element analysis. Finally, the theoretical model and the experimental modal analysis models were compared, and get closer to the actual situation of a model to conduct several times analysis. Thus, this paper presents a reliable and convenient method to study the characteristics of machine tools; this method can reduce unnecessary costs and find structural weaknesses in machine designs for improvement.

This study investigated hollow stemmed hip forging for enhancing the biocompatibility of Ti-6AL-4V titanium alloys. Instead of using the expensive titanium billet, this study applied DEFORMTM 3D finite element analysis software to simulate and analyze stem forming with respect to different die temperatures, friction factors, punch types, forging velocities, and billet temperatures. On the basis of its shape, a punch can be classified as flat head, ladder shaped, spherical, and conical. These differences affect the effective stress and punch load after stem formation. The experiment parameters were determined using the Taguchi L16 (45) orthogonal table. Both the simulated and experimental results indicated that the error for the size of the bone stem was less than 2%.

The effect of various factors on the amount of warpage in an injection molded product was investigated and a plastic spur gear was used as an example. The research involved the design of a mold and die, computer-aided engineering, simulation analysis, and the determination of the plastic material and parameters. Simulation results were verified by experiment using the fabricated mold and die. Small warpage was determined using software, and the Taguchi and Response Surface Methods were used to determine the optimal parameter combinations. The optimum parameters were found to be: injection pressure, 105 MPa; packing pressure, 70 MPa; packing time, 19 s; mold temperature, 60 °C; and plastic temperature, 190 °C. The experiments were repeated, and the results were compared with the simulations to verify the reliability of the simulation results.

This study explores 38 students of mechanical engineering at the University of Technology. The experiment group and the control group are used to compare the differences in the satisfaction of students with and without the intervention of topic-oriented teaching materials, and to understand the situation of learning satisfaction after the training with external students. This study uses a questionnaire distribution method for analysis and research. The content of the questionnaire is divided into two parts: student background attribute data and student learning satisfaction. The analysis is based on descriptive statistics and t test correlation.

With the advancement of technology, aiming for achieving a greater lightness and smaller size of 3C products, parts processing technology not only needs to explore the basic scientific theory of materials but also needs to discuss the process of deep drawing numerical and the plastic deformation. This study is based on the square shape of the deep drawing numerical simulation, and aluminum alloy plastic flow stress was input into the finite element method for simulation of plastic deformation in the aluminum alloy friction, mold clamping force, and frequency, as well as amplitude in the influence of forming mechanism and the drawing ratio of aluminum alloy. Finite element analysis software has the function of grid automatic rebuild, which can rebuild the broken grid in the analysis into a complete grid shape, which can avoid the divergence caused by numerical calculation in the analysis process. The greater the obtained error value, the best plastic parameters can be found.

In this paper, a dynamic stress analysis of seismic vibration isolator was carried out by using ANSYS. The vibration isolator consisted of Si-Cr springs and magnetorheological dampers. The stress and deformation of the springs were calculated when an impact load was applied to the isolator. From the simulation for six different springs, in terms of their wire dimeter and coil diameter, an optimum shape of the springs to minimize the stress and deformation was determined.

This study integrated Analytic Hierarchy Process and Taguchi method to investigate into injection molding warpage. The warpage important factor will be elected by Analytic Hierarchy Process (AHP), the AHP hierarchy analysis factor from documents collected and aggregate out data, then through the expert questionnaire delete low weight factor. Finally, we used Taguchi quality engineering method to decide injection molding optimized combination factors. Furthermore, the paper used injection pressure, holding pressure, holding time, mold temperature to analyze four factors, three levels Taguchi design data. Moreover, the paper discussed the reaction of each factor on the S / N ratio and analysis of variance to obtain the best combination of minimal warpage.

This study proposes a cold drawing technology of wire rod with rotating die; it carries out an FEM simulation on rotating drawing using DEFORM-3D commercial software. Frictions among the die and the wire material are assumed as constant shear friction. The effective stress, the effective strain, the velocity field, and the drawing force can be determined from the FEM simulation. In this study, effects of various drawing conditions such as the rotating angular velocity, the half die angle, the frictional factor, the die filet on the drawing forming characteristics are explored effectively. From this FEM simulation, it is noted that the rotating die effect can reduce the drawing force and increase the material flow.

The purpose of this study is to explore the employability of the Department of Mechanical Engineering of the National Science and Technology School after graduation, and to study the employers of social freshmen and machinery-related enterprises who graduated from the Department of Mechanical Engineering within five years. with regard to mechanical related abilities, general common abilities, and behavioral attitudes. The correlation between the three major employment performances. The research target is 123 fresh people from the country who have graduated within five years of student and 112 employers people from all over the country. Graduates use Employability Table for Mechanical and Mechanical College Graduation in Science and Technology Colleges self-assessment of core employability performance. The Employers uses Employability Table for Mechanical and Mechanical College Graduation in Science and Technology Colleges to assess the graduates’ employment performance. The results of the study show that there are significant differences between graduates and employers in terms of the three major employability-oriented items, and the scores of graduates are generally higher than those of employer. Finally, based on the research findings, this study proposes relevant suggestions for improving the core employment and future research of college students.

Cultivating the employability of students is one goal of the pursuit of higher education. In order to improve the performance of university education, the employability of graduates must be enhanced. The purpose of this study is to find the industry and academia's views on employability expected of graduates and the gap between the industry and academia in order to put forward suggestions for improvement, with the focus groups method as the research method. Research results show: The industry attaches greater importance to employability. The “specific skill and knowledge related abilities” dimension includes “computer skills (word processing, professional software application and program writing)”, and “applying rules and regulations”; the “general abilities” dimension includes “working under pressure”; the “behavior/attitude qualities” dimension includes “initiative”, “adaptability”, “loyalty, integrity”, and “tolerance, appreciation of different points of view”.

In this study using ductile fracture criterion defined fracture energy, determining the critical damage value of normalized Cockcroft –Latham. True stress-strain value and materials properties were obtained from the tensile tests of zirconium alloy 702 and finite element analysis. It was observed that specimen fracture the maximum value occurred in the central area of the cross section, the highest critical damage value equal to 0.649. In this paper, through the inverse analysis method of the FEA to explore on rarely research data zirconium alloys. The results proposed to evaluate the forgeability, expect the present study could be used as a basis of designing and developing zirconium alloy.

In this paper, construction of finite element analysis based on DEFORMTM 3D four-blade face milling cutter aluminum 6061 cutting, explore the finite element analysis of face milling cutter rotating in a circle cutting of aluminum alloy 6061.Tool types used WC milling cutters, cutting speed, feed rate as fixed process parameters. The study analyzed four rotations of the blade face milling chip formation, effective stress, effective strain and material changes in temperature and tool wear.