Abstract: The component placement sequence and feeder arrangement are two critical factors determining the assembly time of chip-shooter machine (CS). In addition, the different size of component and different arrangement strategy affect the feeder arrangement and component placement sequence. Based on the engineering analysis, an integrated optimization model of printed circuit board (PCB) assembly for CS machine is established. According to the parallel placement character of CS machine, "Max-Min Ant Colony Algorithm with Communication function (MMAC)" is designed based on traditional Ant Colony Algorithm. The idea that two ants with different duties collaborate to solve the optimization problem is presented. Guide ants optimize placement sequence while executant ants optimize feeder arrangement according to the components placement sequence. The component placement sequence and feeder arrangement are optimized simultaneously
Abstract: Taiwan’s solar power industry has developed midstream cell manufacturers with a certain share of the global market. Therefore, examining the operating performance of Taiwanese solar cell manufacturers has become vital for the international competitiveness of Taiwanese manufacturing. This study used a two-stage data envelopment analysis (DEA) method to measure the operational abilities and profitability of Taiwanese solar cell manufacturers. The research period for this study was between 2009 and 2011. This study’s primary contribution is in constructing a performance evaluation model for the solar cell industry to assist relevant manufacturers in the Taiwanese solar power industry in formulating operational strategies.
Abstract: Numerical research on three dimensional flow field of a propeller and actuator disk model have been made. Under design conditions (headway 66.889m/s, revolving velocity 2575rpm）, the Slipstream flow field after Propeller is solved by RANS equations with structure mesh. Chosen 12 million mesh through verification of reliability analysis. The numerical result consists of the flow field and vortex field in the propeller slipstream. With comparison to the calculation result of standard strip theory and actuator disk model, it is shown that for light load propeller with the side small contraction of slipstream, in the slipstream cross section after 0.6R away from downstream of propeller rotation plane, the axial, circular and radial induced velocity coefficient by Prandtl’s blade tip corrected standard strip theory result; three dimensional flows numerical simulation and actuator disk model are well consistent. It verified the correctness of standard strip theory and also provided scientific basis for the correction of actuator disk model
Abstract: Gravity heat pipe’s interior phase change and heat transfer mechanisms are hardly to research, yet significant for strengthening heat transfer and enhancing energy utilization. This paper reports experimental study on the reconstructed images and concentration measurement of liquid (ethanol) at condensation section of gravity heat pipe with electrical capacitance tomography (ECT). Furthermore, signals’ noises collected by ECT have been reduced with Hilbert-Huang transform (HHT). Finally, reconstruction images have been compared with M. Shiraish’s model, and ECT has provided alternative experimental platform for the research of gravity heat pipe’s mechanisms.
Abstract: The fatigue crack growth behavior of one compact tension specimen of 16MnR steel under high-low sequence loading was investigated. The symmetric half finite element model under plane-stress state was used to calculate the elastic-plastic stress-strain responses, in which the Armstrong-Frederick type cyclic plasticity model was implemented as a user material subroutine UMAT of ABAQUS. A recently developed dynamic crack growth model was used to simulate the effects of high loading step on the successive low loading step. The detailed evolution process of the crack closure and cyclic plastic zone within the retardation region of fatigue crack growth was obtained. The extend of the crack closure, the size of cyclic plastic zone and the stress gradient have significant influence on the fatigue crack growth rate. The predicted fatigue crack growth rate is in good agreement with the experimental data.
Abstract: Validation of existing software design models and transformed target models for the study, mainly checking (Model Checking) with a code-based software designed to define in the abstract syntax tree or on the models generated using refactoring on design models for refinery operations and define how to perform. The problem with these traditional research methods, but the first model, design model for checking the information with the model by defining a formal representation in the form of an abstract syntax tree, as you've shown how to perform validation of UML design model. Additional steps need to define more complex due to a software problem that is not the way to the model suitable for model transformation verification. In this paper, as defined in the MDA based model transformation studies of a graph based mode transformation, and how to perform model transformation verification through improving graph comparison algorithm and model property information.
Abstract: CFRP laminates made of nano-particles-coated carbon fibers and damaged by a simulated lightning strike were tested under the compression-after-impact (CAI) mode, during which the damage progression was monitored by acoustic emission (AE). The effects of nano-particles coating on the degree of lightning-damage and the mechanical integrity of composite structures damaged by lightning strikes have been evaluated in terms of AE activities.
Abstract: System fault behavior model is a behavioral model to describe the occurrence and development process of system fault. It can reliaze fault propagation through the description of system normal and fault behavior. The application of system fault behavior model was studied in this paper. The method of FMEA and FTA based on system fault behavior model was brought forward and the process and steps of this method were discussed in detail. Finally, a typical case was analyzed to validate the effectiveness and practicness of this method.
Abstract: In order to improve the engineering performance of lightweight design on the driving axle housing, lightweight, structural mechanics, fatigue strength and dynamics are applied in the multidisciplinary design optimization. Firstly, finite element model of driving axle housing was established and its accuracy was verified through bench tests. Secondly, driving axle housing system was divided into multiple sub-discipline systems and design variables of multidisciplinary lightweight design were determined, in order to solve the problems of large amount of data transmission and complex calculation, sparse grid approach was used to establish high accuracy approximate model of each discipline. Lastly, mass of driving axle housing and difference values of first six order modal frequencies before and after lightweight design were optimized through Non-dominated Sorted Genetic Algorithm-Ⅱ, the Pareto optimal solution set was obtained. In optimization results, masses of driving axle housing are all decreased compared to the initial design, meanwhile, the dynamic performance, structural static intensity and fatigue life are all ensured.
Abstract: Rough sets theory (RST) is a new data mining method that effectively deals with the problems with inexact, uncertain or vague knowledge in a complex information system. This paper investigates knowledge discovery methods from the textile industrial database, and then presents a RST-based intelligent control model (ICM) for spinning process. In order to analyze the yarn strength when the characteristics of fibers are given, a rule extraction method based on RST is researched. The logical rules extracted from the decision table indicate that the initial strength of fibers is a key factor influencing on the yarn strength. At the same time, the different values combination of the final reduced attributes also obviously influence on the yarn strength in different degree when the certain nominal yarn is being processed. Therefore, RST method can be taken into account for spinners to choose suitable fiber materials in order to ensure the quality and reduce cost.