This study introduces a time-dependent micromechanical model for a viscoelastic-viscoplastic analysis of particle-reinforced composite and hybrid composite. The studied particle-reinforced composite consists of solid spherical particle and polymer matrix as constituents. Polymer constituent exhibits time-dependent or inelastic responses, while particle constituent is linear elastic. Schapery's viscoelastic integral model is additively combined with a viscoplastic constitutive model. Two viscoplastic models are considered: Perzyna's model and Valanis's endochronic model. A unit-cell model with four particle and polymer sub-cells is generated to obtain homogenized responses of the particle-reinforced composites. A time-integration algorithm is formulated for solving the time-dependent and inelastic constitutive model for the isotropic polymers and nested to the unit-cell model of the particle composites. Available micromechanical models and experimental data in the literature are used to verify the proposed micromechanical model in predicting effective viscoelasticviscoplastic responses of particle-reinforced composites. Filler particles are added to enhance properties of the matrix in the fiber reinforced polymer (FRP) composites. The combined fiber and particle reinforced matrix forms a hybrid composite. The proposed micromechanical model of particle-reinforced composites is used to provide homogenized properties of the matrix systems, having filler particles, in the hybrid composites. Three-dimensional (3D) finite element (FE) models of composite's microstructures are generated for two hybrid systems having unidirectional long fiber and short fiber embedded in cubic matrix. The micromechanical model is implemented at the material (Gaussian) points of the matrix elements in the 3D FE models. The integrated micromechanical-FE framework is used to examine time-dependent and inelastic behaviors of the hybrid composites.

A fixed geometry hybrid thrust bearing is investigated with three different supply orifice diameters. The test rig uses a face-to-face thrust bearing design, with the test bearing acting as the rotor loading mechanism. A hydraulic shaker applies the static axial load, which is reacted by a second thrust bearing. The rotor is supported radially by two water-lubricated fluid film journal bearings and is attached to a 30,600 rpm motor via a high speed coupling with very low axial stiffness. Thrust bearings with three different orifice diameters (1.63, 1.80, and 1.93 mm) are tested for a range of supply pressures, fluid film thicknesses, and rotational speeds. The water-lubricated test bearings have eight pockets, with feed orifices located centrally in each pocket. Experimental results are comparted to predictions found using bulk flow model HYDROTHRUST. Analysis of the data reveals generally good agreements between predictions and measurements. Thrust-bearing inlet supply and inner radius flow rates all decreased with decreasing orifice diameters and bearing axial clearances. In most cases, the bearings with larger orifice diameters exhibit higher recess pressure ratios, operating clearances, and flow rates. The largest orifice diameter configuration does not display higher recess pressure ratios or operating clearances at high speeds for some supply pressures, but it does continue to require additional lubricant flow rate compared to the smaller orifice bearings. In these cases, the results are not reflected in predictions, which otherwise correlate very well with experimental measurements. Estimations of static loading axial stiffness are obtained using experimental results. An optimum hybrid thrust bearing orifice diameter will depend on the conditions of individual applications. Larger orifices generally provide larger operating clearances and higher stiffnesses, but also require higher flow rates. For most applications, a compromise of bearing performance parameters will be desired. The test results and comparisons presented will aid in sizing orifice diameters for future hybrid thrust bearing designs.

In this paper, single mode buried optical waveguides based on hybrid sol-gel glasses and PECVD oxide were fabricated. Two different buried waveguide devices are investigated, and their optical characteristics are characterized. The first buried waveguide was obtained by etching a shallow trench on SiON layer. Then sol-gel material used as the guiding layer was deposited onto the layer and cured in proper conditions. Finally, the waveguides were completed by coating a sol-gel top cladding layer onto the guiding layer. The propagation loss of the waveguide is 0.59dB/cm at £f=1310nm. The second buried waveguide was fabricated by etching a trench of 5£gm on SiON layer and then burying sol-gel material into the trench.Proximity printing was used to define the waveguide core on sol-gel films.The waveguide was packaged for measurement after coating a UV glue on top of the core layer. The propagation losses of this waveguide device are 0.6dB/cm and 0.57dB/cm for TE and TM polarized lights. The coupling losses are 2.21dB and 2.41dB for TE and TM lights.

The unsaturated polyester/silica hybrids have been synthesized via sol-gel process and characterized in an effort to obtain a transparent hybrid material in this study, with emphasis on the effects of silica precursors and coupling agents. Chemical properties, thermal properties, and morphology of the hybrids were investigated by Fourier-transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), and scanning electron microscopy (SEM). The results showed that silica particles can be dispersed homogeneously in the UP matrix; also, physical and chemical interactions at the interface between UP and silica can be enhanced by adding coupling agents into the system. From the thermal and chemical properties measurement, the decomposition temperature of UP backbone and the heat distortion temperature (HDT) of UP/Silica hybrid were higher than pure UP. Solvent-resistance of UP/Silica hybrid was also enhanced by adding coupling agents. A model illustrating the chemical and physical interaction at the interface due to the addition of coupling agents is proposed to explain the resulted obtained.

This thesis aims to fabricate the high performance Magnesium/Carbon-Fiber/PEEK five-layer hybrid nanocomposite laminates. The adopted Mg thin sheets are 0.5mm thick. The Carbon-Fiber/PEEK prepregs were stacked into two lay-ups, such as cross-ply [0/90]s and quasi-isotropic [0/45/90/-45], with the adding of nanoparticles SiO2 spreaded among the laminates. After etching of Mg foils by CrO3-base etchants, a five-layered Mg/Carbon-Fiber/PEEK nanocomposite laminate was made according to the modified diaphragm curing process. Then, the mechanical properties, such as stress-strain curve, strength and stiffness were obtained by tensile test at room temperature (25¢J), 50, 75, 100, 125 and 150¢J and the fatigue properties were also obtained under constant stress amplitude tension-tension cyclic loading elevated at room and elevated temperatures 25, 75, 100, 125 and 150¢J. Finally, the Mg sheets and fractured laminates were observed by the SEM and OM. The results according to the experiments were summarized as follows: 1.The slope of stress-strain curve dropped at strain¡Ü0.0015. It can be inferred that fracture occurred in the laminates at this time. Stiffness approached the theoretical value by curve fitting with the strain range of 0 to 0.0015. 2.The mechanical properties decreased with the environmental temperature rise. 3.The resistance to the temperature effect of the quasi-isotropic Magnesium/Carbon-Fiber/PEEK laminate is superior to that of the cross-ply Magnesium/Carbon-Fiber/PEEK laminate. 4.The cross-ply Magnesium/Carbon-Fiber/PEEK laminate is brittler than that of the quasi-isotropic laminate generally. 5.The irregular bright lines were found in the third etched Mg sheet and that resulted in the delamination of Mg sheet after treatment. The unetched part maybe the defect of Mg sheet. 6. It was found that AZ31 has the precipitation hardening effect at 50¢J and 75¢J.

There are two main architectures in VOIP system at present. First is peer-to-peer, it has highly scalable, fault-tolerant and also can lighten the number and reliance of server. But there is no standard protocol between peers with different architecture, cause the clients unable to communication with each other. This problem can be solved by communicating from one P2P network to another. Second is Client-Server, it has mass of research data, lots of actual products, and standard protocol. This architecture is the most perfect one with simple structure, easy to maintain, lower response time than peer-to-peer structure, and has a variety of additional services, for instance Voice Mail, conference call, etc. All the client need is to obey sip standard protocol and it can register to any sip proxy to make a phone call. The disadvantage is no server no use. These two architectures have both good side and bad side, none of them is absolutely perfect. Our thesis is proposed a all new idea about ¡§Hybrid¡¨, this idea combine P2P and Client-Server architecture together to design a flexible soft phone that can be used is normal condition to register to a proxy, or setup a P2P network instantly in our own local area network. Finally our DCHS Mechanism is workable even when the sip proxy is maintaining or failure the client can use this mechanism to call any other user outside the P2P network by sharing other peers¡¦ call history.

Since the cost of software testing has continuously accounted for large proportion of the software development total cost, automatic test data generation becomes a hot topic in recent software testing research. These researches attempt to reduce the cost of software testing by generating test data automatically, but they are discussed only for the single version programs not for the programs which are needed re-testing after changing. On the other hand, the regression testing researches discuss about how to re-test programs after changing, but they don¡¦t talk about how to generate test data automatically. Therefore, we propose an automatic test data evolution strategy in this paper. We use the method of regression testing to find out the part of programs which need re-testing, then automatic evolutes the test data by hybrid genetic algorithm. According to the experiment result, our strategy has the same or better testing ability but needs less cost than the other strategies.

There are many business in Taiwan that their production type are indistinct between make-to-stock and make-to-order. This kind of production type can shorten the lead time of order and decrease the fluxion of customer¡¦s demand, on it¡¦s technology of predicting customer¡¦s demand for pre-production and inventory. Thus, the efficacy of production must depend on it¡¦s precision of predicting customer¡¦s demand. Recognition that traditional work order dispatching made to some specific standardization. Therefore, it is leaded to customization product and less flexible. And the decision-maker must choose one goal between minizing inventory cost, WIP¡¦s level and lead time. The production type, work order dispatching must have flexibility,and it must accomplish the customer¡¦s order on time considering inventory cost and customer service. This thesis hopes that it would be to develop a work order dispatching method to improve the efficiency of WIP administering, the flexibility for work order dispatching and decreasing lead time of customer¡¦s order. According to production¡¦s characteristic of different manufacturing stage, it can create one applicable dispatching rules to increase the production efficiency. Finally, using simulation software, applying to case study comparing the performance of the real case and new work order dispatching

A series of PMMA/silica hybrid composites were prepared by a sol-gel process in different catalytic and drying. Their thermal properties were analysized by DSC and TGA, the micro-structures by SEM, and the chemical reactions by FTIR. The highest decomposed temperature of these hybrid composites were found for samples prepared at low pH due to the hydrogen bonding. DSC data indicated the samples cured at 25 and 140 oC existed a higher Tg due to unhydrolyzed TEOS. The heat-treated hybrid composites exhibited more compact structures. The size of SiO2 particles from SEM increases with increasing drying temperature and pH value. The hybrid composites prepared in acid condition showed more Si-O-Si bonding than Si-O-C bonding in FTIR. In addition, in FTIR spectra the shifts have been observed from a non-hydrogen-bonded C=O at 1733cm-1 to a hydrogen-bonded carbonyl at 1725cm-1.

Previous studies have indicated the level of total sulfur amino acids (TSAA) (methionine + cystine) is most limiting in practical diet formulations for hybrid striped bass (HSB), especially if animal feedstuffs are replaced with plant feedstuffs. Reduction of costly animal feedstuffs such as fish meal while maintaining adequate dietary levels of TSAA may enhance cost effectiveness of production. Therefore, this study, consisting of four separate feeding trials, investigated three different aspects of sulfur amino acid nutrition of HSB including: (1) the efficacy of crystalline methionine hydroxy analog (MHA) and liquid MHA (AlimetTM) relative to L-methionine in meeting the requirement for TSAA; (2) the cystine sparing value for methionine; and, (3) the influence of various sulfur amino acid supplements on ammonia excretion. During the feeding trials, juvenile HSB were fed various diets including a basal diet deficient in TSAA (0.33 or 0.51% of diet), and experimental diets supplemented on an equalsulfur basis with different levels of either L-methionine, AlimetTM or crystalline MHA. Diets containing TSAA at 1% of diet and different ratios of cystine to methionine (60:40, 55:45, 50:50, and 45:55) also were fed to re-evaluate sparing effects of cystine on methionine. During the ammonia excretion trial, HSB were fed diets containing either L-methionine,AlimetTM or crystalline MHA after which total ammonia nitrogen (TAN) excretion was determined 4 h postprandial. In trial 1, AlimetTM was 73% as effective in promoting growth as L-methionine at the same concentration while MHA was 83% as effective. In trial 3, fish fed AlimetTM at 1.25% of diet displayed similar growth performance as those fed TSAA at 1.0% of diet while weight gain of fish fed AlimetTM at 1% was only 58% of that displayed by fish fed TSAA at 1.0%. No significant differences in weight gain, feed utilization or survival were observed among fish fed diets containing various ratios of cystine to methionine although the diet with 60:40 cystine to methionine supported the lowest responses. Inclusion of MHA or AlimetTM did not affect TAN excretion of HSB. These findings will aid in refining diet formulations for HSB to ensure adequate sulfur amino acid nutrition.