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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

The Study of the Environmental Effects on the Optical Performance of Backlight Module

Yu, Chun-Yi 23 January 2007 (has links)
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.
2

Numerical Analysis of The Performance of a Water-Washed Air Cleaner

Tsai, Chia-Shiuan 08 August 2011 (has links)
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.
3

Berth Schedule Planning of the Kaohsiung Port by Genetic Algorithms

Tsai, An-Hsiou 09 September 2011 (has links)
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.
4

µL

Wu, Chia-chan 14 December 2006 (has links)
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.
5

Dynamic Simulation and Performance Optimization of Reheating Furnace

Chen, Jian-Wen 06 July 2000 (has links)
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.
6

The study on the power conversion from a sloshing liquid of U-column

Wu, Chung-yang 31 August 2008 (has links)
This research will use a vibrating U-tube which will cause the water around the tube sway in but will manage the helix leaf blade water turbine which (1998) will develop using Gorlov (Gorlov Helical Turbine). It will also study and discuss electricity generating technology. The vertical motion created external force under the U-tube and about the water will cause the fluid to vibrate and lead the tube cause the domestic water turbine to rotate thus generating electricity. In this article discovers the best size for a generating system and the power rate using the Taguchi method and manufactures the U-tube generating system model and the predecessor gauges the data to make the confirmation, the experimental result discovered the Taguchi method and the actual gauging data best tallies the size. The test results show that in the tube, the fluid oscillation frequency and the blade area rate can affect the structure of the system as well as the true power rate while the external force cycle resonance frequency scope generates electricity.
7

Tooth Interior Fatigue Fracture&Robustness of Gears

MackAldener, Magnus January 2001 (has links)
The demands the automotive gear designer has to considerduring the gear design process have changed. To design a gearthat will not fail is still a challenging task, but now lownoise is also a main objective. Both customers and legalregulations demand noise reduction of gears. Moreover, thequality of the product is more in focus than ever before. Inaddition, the gear design process itself must be inexpensiveand quick. One can say that the gear designer faces a newdesign environment. The objective of this thesis is tocontribute to the answer to some of the questions raised inthis new design environment. In order to respond to the new design situation, the geardesigner must consider new phenomena of gears that werepreviously not a matter of concern. One such phenomenon is anew gear failure type, Tooth Interior Fatigue Fracture (TIFF).As the gear teeth are made more slender in an attempt to reducethe stiffness variation during the mesh cycle, therebypotentially reducing the noise, the risk of TIFF is increased.The phenomenon of TIFF is explored in detail (paper III-VI)through fractographic analysis, numerical crack initiationanalysis using FEM, determination of residual stress by meansof neutron diffraction measurements, testing for determiningmaterial fatigue properties, fracture mechanical FE-analysis,sensitivity analysis and the development of an engineeringdesign method. The main findings of the analysis of TIFF arethat TIFF cracks initiate in the tooth interior, TIFF occursmainly in case hardened idlers, the fracture surface has acharacteristic plateau at approximately the mid-height of thetooth and the risk of TIFF is more pronounced in slender gearteeth. Along with the more optimised gear design, there is atendency for the gear to be less robust. Low robustness, i.e.,great variation in performance of the product, implies a highincidence of rejects, malfunction and/or bad-will, all of whichmay have a negative effect on company earnings. As the use ofoptimisation decreases the safety margins, greater attentionhas to be paid to guaranteeing the products' robustness.Moreover, in order to be cost-effective, the qualities of thegear must be verified early in the design process, implying anextended use of simulations. In this thesis, two robustnessanalyses are presented in which the analysing tool issimulation. The first one considers robust tooth root bendingfatigue strength as the gear is exposed to mounting errors, thesecond one considers robust noise characteristics of a gearexposed to manufacturing errors, varying torque and wear. Bothof these case studies address the problem of robustness ofgears and demonstrate how it can be estimated by use ofsimulations. The main result from the former robustnessanalysis is that wide gears are more sensitive to mountingerrors, while the latter analysis showed that to achieve robustnoise characteristics of a gear it should have large helixangles, and some profile- and lead crowning should beintroduced. The transverse contact ratio is a trade-off factorin the sense that both low average noise levels and low scatterin noise due to perturbations cannot be achieved. <b>Keywords</b>: robust design, Taguchi method, gear, idler,simulations, Finite Element Method, Tooth Interior FatigueFracture, TIFF
8

Fabrication of Compound Film

Wu, Chia-Jung 12 August 2010 (has links)
The backlight module is usually used to increase visual angle and brightness of liquid crystal display (LCD). Thus, the design and fabrication of optical films, including light guide plate, diffuser film, and brightness enhancement film (BEF), are critical factors to decide the optical efficiency in a backlight module. In order to improve the optical efficiency for power-saved display with competitiveness, this study presents a new fabrication process combining precision machining, lithography, and hot-embossing techniques to form a two-side-patterned optical film. One side of the optical film is micro triangular-pyramidal array (MTPA) and the other is micro spherical lens array(MSLA). First, the Taguchi method is applied to design the optimal microstructure configuration by the assistance of the optical software, FRED. Second, a tungsten (W) steel mold (as the mold to hot emboss MTPA) is manufactured by precision machining including optical projection grinding, lapping, and polishing processes. Meanwhile, a nickel-cobalt (Ni-Co) mold (as the mold to hot emboss MSLA) is fabricated by electroplating process. Then, polydimethylsiloxane (PDMS) is used to replicate the MTPA and MSLA patterns, on W and Ni-Co metal molds, respectively, and the replicated PDMS films are used as the molds to form a two-side-patterned optical film. In addition, the optical property such as luminance is measured by photo research 650 (PR 650) to evidence the optical function of the two-side-patterned optical film. From the experimental results, both brightness and uniformity can be improved by this film;thus, optical efficiency is successfully increased in this study.
9

The growth and physics of (La1-xSrx)MnO3∙SrO thin film

Chen, Shu-hsiang 29 January 2004 (has links)
(La0.67Sr0.33MnO3)£»(SrO), LSMO214(n=1) in short, is 2-D magnetic insulator with a structure very similar to the 3D La0.67Sr0.33MnO3 and La0.67Ca0.33MnO3, 113(n=1) in short, which consists of superstructure of a subsequent magnetic layers and insulating layers. Forming a single 214 phase bulk is not easy, a mix phase of 2<n<¡Û compounds is usually seen. In this project, our goal is to search the best growth condition by the traditional method by varying one growth parameter at a time and by the famous Taguchi methods which is based on the statistics and is proved in many systems a best way in studying the association between the film properties and the control factors. First part of this project, we change one growth condition at a time and find the film quality related with the growth condition. Second, we use ¡§Taguchi method¡¨ as bases to form a perpendicular table in which various growth conditions and levels are set. According the table, the number of experiments is limited down to nine. All of the films are examined by structure, electric and magnetic properties to formed the quality data base for films. The traditional method concludes that the higher growth temperature, lower total chamber pressure and high partial pressure ratio of Ar and Oxygen are the corrected way approaching to the single phase, 214, films. However, the result from Taguchi method is contradict to the tradition method, in which the high growth temperature, high total chamber pressure, low partial pressure ratio of Ar and oxygen and the medium RF forward power can approach to growth the single 214 phase film. All films consists mix phases of higher n. This may imply that the growth window for LSMO 214 is relative narrow that we did not set our condition right in that opening.
10

Planning for Curved-Surface Milling and Surface Profile Measurement by Taguchi Method

Wang, Hsueh-o 30 June 2006 (has links)
ABSTRACT This research uses Taguchi Method, combined with Computer Aided Design and Manufacturing, processing the work piece into the saddle type. Next, diverse sampling methods are applied to measure the profile of surface with Coordinate Measuring Machine, with an aim to analyzing the main factors that influence cutting and seeking the last conditions for cutting out the curved surface; in addition, I will probe into the contribution rate of each factor which influences the precision during the process of measurement. The following results of this research are expected to be offered to the circles of vocational education as a basis of processing and measuring instruction. In this way, it will not take too much time to try and error and therefore, the practice course can be more efficient. 1. With reference to the documents that are focused on the factors affecting the cutting, this thesis, by means of Taguchi Method, shows that during the process of cutting saddle-type curved surface, the rotating speed of the axle is the most influential, whose contribution rate is 59.38%. 2. Since most documents are on circles, balls or cone objects, this thesis will aim at the measurement of saddle-type curved surface, with an intention to further the measuring technique. 3. It is found that as to the saddle-type curved surface, random sampling can get the profile of surface with minimal errors, and has no such trouble as using HSS or LHS, which can reduce time and cost. 4. In the experiment of Taguchi Method, according to analysis of variance, the influence of the sampling area is the greatest while the choice of sampling method only contributes to 3.46%.

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