Neuro-Genetic Optimization of the Diffuser Elements for Applications in a Valveless Diaphragm Micropumps System

In this study, a hybridized neuro-genetic optimization methodology realized by embedding numerical simulations trained artificial neural networks (ANN) into a genetic algorithm (GA) is used to optimize the flow rectification efficiency of the diffuser element for a valveless diaphragm micropump application. A higher efficiency ratio of the diffuser element consequently yields a higher flow rate for the micropump. For that purpose, optimization of the diffuser element is essential to determine the maximum pumping rate that the micropump is able to generate. Numerical simulations are initially carried out using CoventorWare® to analyze the effects of varying parameters such as diffuser angle, Reynolds number and aspect ratio on the volumetric flow rate of the micropump. A limited range of simulation results will then be used to train the neural network via back-propagation algorithm and optimization process commence subsequently by embedding the trained ANN results as a fitness function into GA. The objective of the optimization is to maximize the efficiency ratio of the diffuser element for the range of parameters investigated. The optimized efficiency ratio obtained from the neuro-genetic optimization is 1.38, which is higher than any of the maximum efficiency ratio attained from the overall parametric studies, establishing the superiority of the optimization method

Computational methods in Flipchip assembly.

Flip chip technology, in the book edited by Lau (Lau, 1995) is defined as placing a chip to the substrate by flipping over the chip so that the I/O area of the chip is facing the substrate. By flipping over the chip, the interconnection between the chip and the substrate are achieved by conductive "bumps" placed directly in between the die surface and the substrate. Therefore, the whole chip surface can be utilized for active interconnections and at the same time, eliminates the need for wire bonding

Computational Methods In Flip Chip Assembly.

Flip chip technology, in the book edited by Lau (Lau, 1995) is defined as placing a chip to the substrate by flipping over the chip so that the I/O area of the chip is facing the substrate. By flipping over the chip, the interconnection between the chip and the substrate are achieved by conductive "bumps" placed directly in between the die surface and the substrate. Therefore, the whole chip surface can be utilized for active interconnections and at the same time, eliminates the need for wire bonding

Towards human performance measurement from the maintenance perspective: a review

With organisations adopting maintenance as a profit-generating business element, the role of maintenance in modern manufacturing industries is becoming even more important, clearly underscoring the importance of bringing maintenance operations in harmony with corporate business objectives. This area of study concerning the human aspect in over-all maintenance operations has received much emphasis recently. People in maintenance are not only limited in conducting diagnoses and error recovery, but also in planning and scheduling, recording data, handling and operating equipment, and training maintenance personnel. The performance of mission tasks manifests the abilities and limitations of humans involved in any system. Thus, since they are essential in systems operations, the effects of their performance on maintenance require a thorough study. This paper reviews current approaches for analysing, evaluating, and managing human performance in various industries focusing in the maintenance environment. Recommendation for future studies regarding a new approach to effectively evaluate the performance of maintenance personnel has been suggested.human performance; maintenance personnel; performance measurement; modelling; qualitative models; quantitative models; review; human error; performance management.