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Liquid crystal display is the most valuable and universal produce of the electric monitor presently and it will into the stage of stable. In the future, the reliability is more important and also will be gradually the key point of index. Most of studies about the reliability of the back light module that concentrate on the thermal effect, there are seldom researches corresponding to the humidity and time effect. Therefore, we emphasize thermal, humidity and time factor for optical performance influence of the back light module in this thesis. We also used the experimental design of Taguchi method to determine the most important factor and development the basic for the reliability of the back light module. According to the result, the changing of the temperature influence the optical performance is the most.

La Ventilation par Oscillation Hautes Fréquences (VOHF) consiste en l'insufflation à haute fréquence de volumes courants inférieurs à l'espace mort anatomique, de façon à épurer le dioxyde de carbone, résidus des activités cellulaires.Ce travail de thèse se propose d'analyser l'efficacité de la Ventilation par Oscillation Hautes Fréquences. En effet, le traitement des patients à l'aide de la VOHF permet une meilleure prise en charge satisfaisante de ces derniers, mais suite à des réglages empiriques des paramètres impliqués dans son utilisation. En outre compte tenu d'une part de l'inhomogénéité des patients et d'autre part de l'impossibilité de faire des tests cliniques sur les personnes souffrant d'une MMH (Maladie des Membranes Hyaline), ou d'un SDRA (Syndrome de Détresse Respiratoire Aigüe) etc..., l'utilisation de la VOHF devient de plus en plus complexe pour le personnel hospitalier.Pour analyser ces difficultés, nous avons, tout d'abord, identifié l'influence de l'amplitude de pression et celle de la fréquence sur l'épuration de deux modèles simples d'analogues. Les résultats de ces modèles constituent des bases pour la mise en place dans de futurs travaux d'un modèle numérique de VOHF. Ensuite, compte tenu de la limitation des plages de réglage de certains paramètres de la machine de VOHF, nous avons conçu puis réalisé un banc d'essais avec deux types de poumon artificiel. D’après ces études expérimentales, la diffusion forcée reste le mécanisme principal, responsable de l'efficacité de la VOHF. Par ailleurs, l'existence d'une fréquence optimale qui est fonction de la longueur des voies respiratoires des patients (âge) accentue cette efficacité. Cette thèse propose aux médecins les valeurs optimales des paramètres de réglage les plus influences dans l’efficacité de la VOHF. Par ailleurs la vitesse d'entrée d'oxygène, reste le facteur le plus prépondérant, suivie de l'amplitude de pression, de la fréquence d'oscillation et de la gravité dans l’utilisation de la machine de VOHF.Les modèles numériques développés dans ce travail permettent non seulement de valider les résultats expérimentaux mais contribue également à la modélisation numérique de la Ventilation Spontanée (VS) (respiration normale) sur un poumon artificiel quasi identique à un poumon humain. Ainsi le mouvement des 300 millions d’alvéoles et de la cage thoracique a été pris en compte dans ce modèle. Les résultats de ce modèle confirment ceux des travaux existants sur la VS. L'objectif futur serait de mener une étude comparative entre deux modèles numériques, la VS et la VOHF, en tenant compte du mécanisme de diffusion alvéolaire. / High Frequency Oscillatory Ventilation (HFOV) consists of insufflation at high frequency of current volumes lower than anatomical dead space, in order to purify carbon dioxide, which are residues of the cellular activities.This work consists in proving the effectiveness of the HFOV. Indeed, treatment of patients using HFOV allows satisfactory care of them, but with empirical adjustments of parameters involved in its use. Moreover, because of, the inhomogeneity of the patients, in one hand, and the impossibility of making clinical tests on people suffering from HMD (Hyaline Membrane Disease) or ARDS (Acute Respiratory Distress Syndrome), etc…, in the other hand, the use of the HFOV become increasingly complex for hospital staff.To analyze these difficulties, we, first, identified the influence of the amplitude of pressure and that of the frequency on the purification of two simple models of analogues. The results of these models prove that these parameters support the increase in alveoli’s volume according to their elasticity. Other results of these models are the basis for the development of future work in a numerical model of HFOV. Then, because of the limitation of the control range of certain parameters of the HFOV's machine, we designed and conducted series of tests with two types of analogues, the first one having rigid closures in the last generation of branches and the second having flexible closures in the same generation of branches. Thus, with this new device, we carried out the analysis of the influence of each one of these factors over the time of purification of the two models according to 12 sets of parameters of the Taguchi’s table L12 (23x31). With the introduction of the elasticity of flexible membranes, we noted not only, the significant reduction in the purification time, but also that the existence of an optimal frequency, function of the length of respiratory airways of the patients (age), which increases this efficiency. According to this study, the forced diffusion remains the principal mechanism, responsible for the efficiency of the HFOV. The analysis of influence of the parameters setting- entry velocity of oxygen, amplitude of pressure, oscillatory frequency and gravity- has been made in this work.Then, we simulated numerically the two experimental models of the tests, in order to confirm the experimental trends of these factors. Indeed, these two models were implemented in the software CFD (Computer Fluid Dynamic) Fluent. The results from these numerical models are agreed with those of the experimental models.Furthermore, we set up a model of Spontaneous Ventilation (SV) by using a more complex analogue with all the 23 generations of branches that has a human lung. Indeed, the movement of the 300 millions and the rib cage were modeled by that of 2,097,152 pistons. The results of this model confirm those of existing work on the SV.The future goal would be to conduct a comparative study between two numerical models, the SV and the HFOV by taking into account of alveolar diffusion mechanism.

No description available.

Los procesos industriales tienen tres fases diseño del producto del proceso y producción en las que experimentos cuidadosamente diseñados pueden aumentar la calidad del producto y la productividad del proceso. En el capitulo 2 se propone un algoritmo para asignar las variables físicas del experimento a los factores del diseño de forma que el diseño obtenido por proyección sea lo mas informativo posible. En el capitulo 3 se propone un nuevo método mas eficiente y preciso que el hasta ahora conocido para estimar los efectos de las variables sobre la dispersión en la respuesta.

The Veo+ projector is using a cooling system that consists of fan and blowers. This system is cooling the electronic components of the device and the lamp of the projector, however extracting a high noise. To lower this noise the rpm speeds (rotational speed) of the fan and blowers should be decreased. Thus, lowering the speed will result in higher temperature values in whole system (inside the device). While lowering the speed, the higher temperature values should be kept within the thermal design specifications of the electronic components. The purpose of this thesis work is to find an optimal solution with lower rpm speeds of the fan and blowers while keeping the temperatures of the various components of the device (touch temperature of the enclosure and electronic components) within the temperature design limits. Before testing the device to find the optimum state, the design limits of the device are determined. Then, by using the design of experiment methods like Taguchi, the optimum state for the device within the design specifications is obtained. Finally, additional tests are applied within the optimum state to demonstrate a fan algorithm as a final solution. While doing the experiments thermocouples are used for measuring the component temperatures.

The original design of a water-washed air cleaner, which developed by industry, only takes external design and assemblage into account, but the analysis of the overall performance wasn¡¦t studied. The air in the original water-washed air cleaner doesn¡¦t flow smoothly, which cause the inefficiency of the inlet and outlet flow, so there is a necessity to improve its performance. At beginning of this thesis study, the researcher designed the shape of the blades, and then analyzed the internal fluid field of the water-washed air cleaner. He also studied the impact of the efficiency of the aperture of diaphragm and the gap between blade and diaphragm. Finally, he obtained a series of result of simulation with simulating flow field produced by CFD to find out the best shape and amount of blades. The outlet flow performs better when £] is greater. However, when extreme values are between 50 degrees to 60 degrees, the smaller inclination of blade has better efficiency of the outlet flow. The amount of blades is not always positive to the efficiency. When the number of blades is more than 9, there is no significant increase of the outlet flow. The larger aperture of diaphragm has better efficiency, and decreases the gap between the blade and the diaphragm can increase outlet flow. Finally we obtained the result of optimization efficiency by Taguchi Method. After designing the best water washed air cleaner, the vibration is also simulated. The result of simulation showed that the nature frequency of overall structure is much higher than motor¡¦s, so that would not cause the resonant vibration.

For a commercial port, to efficiently schedule the public berths is an important issue. Since a berth schedule would affect the usage of the commercial port, in this thesis, we apply a genetic algorithm to schedule the public berths in order to minimize the total waiting time of vessels. When in the initialization process, we encode the chromosome based on wharf characteristics in order to avoid assigning vessels to inappropriate wharves. After mutation process, we also adjust the usage of wharves to improve the speed of convergence speed. Simulation results show that the proposed algorithm can assign vessels to proper berths as soon as vessels arrive. Compared to the other genetic algorithms, the proposed algorithm obtains better performance in convergence speed and the quality of the solutions.

Research and development department of the industry are generally depend on the experience rule to design products. But the designing process may be very time consuming. The experience, which the former designer accumulates, is probably unable to pass on to new personnel. This will makes new engineer have to use the traditional way to seek the solution slowly. This paper will study the socket, which test the integrated circuit, with forced convection. To discuss the difference of the inlet and outlet positions and geometry when the high-pressure air flow into the socket. And the fluid distribution may have the influence on heat dissipation result. This study uses Taguchi method with CFD software FLUENT, with different design parameters, to do the numerical simulation on the fluid field. To reach the design parameter of the optimization, Fluent uses the grid adaptive technique; it adjusts and optimizes the grid according to a result of calculation, and then made the result of calculation more accurate to offer more reliable design considerations to the designer.

Nowadays, many industries are searching new and effective substitutes for traditional energy resources. Heavy industries are not excluded. In order to use the most of the limited resources, they look for new techniques and new energy management systems which are efficient in energy consumption. Studying in saving energy for reheating furnace and in approving operation conditions may help heavy industries to reduce costs and to enhance quality of products. ¡@¡@Inevitably, the inner compositions of alloy ingots are not uniform during continuous casting. To solve this problem, we usually do heat treatment on alloy ingots before casting. Besides, to ensure the quality and stability of alloy ingots in heat treatment, we need an effective tool to monitor the temperature distribution on ally ingots. Moreover, the precise control over energy consumption can improve the efficiency of reheating furnace and can reduce costs. ¡@¡@This study focuses on alloy ingots. We simulate heat transfer by numerical methods and construct the integrated software to simulate the characteristics of reheating furnace in batch type operation. Analyses in the temperature distribution and energy consumption of alloy ingots in reheating process are also included. Besides, we choose some parameters, which might affect the energy consumption and try to find the best level parameter composition in reheating furnace analysis by Taguchi method. Some results are shown below: ¡]1¡^When temperature rising process starts, our model provides ¡@ ¡@reasonable and exact prediction in one or two hours. ¡]2¡^Reheating furnace treatment ability is the most important ¡@ ¡@control factor (out of eight) in this study. ¡]3¡^We can reduce around 3% of the consumption with the ¡@ ¡@parameters obtained by Taguchi method. ¡]4¡^The soaking degrees are all below 0.01¢J after heat treatment ¡@ ¡@on alloy ingots. ¡]5¡^We change the temperature rising rate to simulate the situation ¡@ ¡@of heated alloy ingots. We find that the higher temperature ¡@ ¡@rising rate is, the more significant temperature difference ¡@ ¡@inside alloy ingots is. On the other hand, the lower rate would ¡@ ¡@increase the soaking degree.