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The heat treatment technology is a weak link in engineering technology in china. For the traditional microwave heat treatment system, the microwave electric field inside the oven can not be well-distributed. In case of the traditional oven heat treatment system, however, the materials dried process is very long. In this paper, we introduce a microwave-oven hybrid heat treatment system related to industrial production line, the proposed with both advantages of high efficiency of microwave and good thermal distribution of the oven, which can be applied for the determination of degree in heat treatment process according to the concentration of the produced gases. Based on the computer and LabVIEW, the control system can control the whole process of heat treatment directly and accurately in real-time.

Traditional incremental conductance method is one of the most widely used methods of MPPT in solar photovoltaic system. But oscillation and misjudgment also exist, which have a great impact on the efficiency and stability of solar system. This thesis proposes a new MPPT algorithm, that is, to combine power prediction method with incremental conductance method organically; simultaneously to apply variable step theory to reduce oscillation and avoid misjudgment. After the simulation in MATLAB7, it proved to be feasible by comparing with traditional incremental conductance.

The compatibility of chitosan (CS) and poly(vinyl pyrrolidone) was investigated by molecular dynamic (MD) simulations using the Flory–Huggins theory. The specific interactions in blends were studied by the radial distribution function (RDF). The Flory–Huggins interaction parameter, χ, was calculated at 298 K to assess the blend compatibility at different component ratios in the polymers. Miscibility was observed for blends with more than 50% of CS in the molar fraction, while immiscibility was prevalent at the molar fraction of CS between 10 and 50% of CS. Miscibility between poly(N-vinyl-2-pyrrolidone) (PVP) and CS polymers is attributed to the hydrogen bond formation of the –C = O group of PVP and the –CH2OH groups of CS. This was further confirmed by MD simulations of RDFs for groups or atoms that are involved in interactions. These results are correlated well to obtain more realistic information on interactions involved as a function of blend composition.

The effect of temperatures and NaCl concentrations on the structures of polyampholyte(carboxyethyl chitosan) under different pH conditions were investigated using molecular dynamics simulations. The radius of gyration (ROG) of the backbone Cα of carboxyethyl chitosan was analyzed and the accessible surface areas (ASA) of entire polyampholytes were estimated. The variation of the ROG and the ASA of polyampholyte with temperatures and different NaCl concentrations under different pH conditions are discussed. The present simulation makes it possible to understand the structures of polyampholyte in aqueous solutions at the molecular level.

In this paper, the stiffness optimization problem is investigated for structures with geometrical nonlinearities. The mean compliance of the structure is chosen as the objective function and its sensitivities are derived using the adjoint method. The optimal problem is formulated using a microstructure-based design domain method and is solved iteratively by a sequential convex approximation method. Three numerical examples are presented to show the applications of the proposed method and the results demonstrate that the geometrically nonlinear finite element analysis is indispensable to the optimization process of large displacement structures.

An automated topology optimization based approach is proposed to generate the optimal stiffener pattern of 3D shell structures with the objective of maximizing a band of eigenfrequencies. The methodology is based on a fiber-reinforced composite model in which the stiffeners and base structure are modeled as Fibers and matrix, respectively. Solutions to the optimization problem are obtained by means of an iterative, two-level procedure based on an optimally criterion approach and a method of mathematical programming using analytical sensitivity analysis. Two numerical examples are presented to demonstrate the effectiveness of the proposed approach.

In this paper, the optimal bead orientation problem of 3D shell/plate structures is investigated for both static and dynamic cases. Using a bending equivalent orthotropic shell design cell model, the optimal bead orientation problem is converted to an optimal orientation problem of bending equivalent orthotropic materials, and it is solved by a new energy based method. In the energy based method, the dependency of strain and stress fields on material orientation is explored by introducing an energy factor in the inclusion model. From the derivations, the strain- and stress-based methods are recovered and their limitations are discussed. Three examples are presented to show the applications of the proposed method.

In this paper, an energy based method is proposed to determine the optimal orientation of orthotropic materials under static loading. Instead of assuming that the strain or stress fields are fixed with respect to orientational variables, the dependency of strain and stress fields on material orientation is explored by introducing an energy factor in the inclusion model. From the derivations, the strain based method and the stress based method can be recovered and their limitations are discussed. Numerical examples from these methods are presented and compared.

Mobility model and call admission control (CAC) algorithm are important for wireless mobility networks. This paper firstly sets a practical mobility model, and then presents a novel measurement-based CAC algorithm utilizing time series analysis under the random model. The algorithm updates the reservation threshold by directly forecasting the next possible number of handoff dropping calls, using ARMA (auto regressive moving average) model. The simulation results suggest that the approach achieves a higher resource utilization than existing approaches while reliably meeting the target handoff-call-dropping probability. Also, the algorithm provides lower new-call-blocking probability.

A systematic topology optimization approach is developed to design the optimal stiffener of three dimensional shell/plate structures in static and eigenvalue problems. Optimal stiffener design involves the determination of the best location and orientation. In this paper, the stiffener location problem is solved by a microstructure-based design domain method and the orientation probelm is modeled as an optimal orientation problem of equivalent orthotropic materials, which is solved by a newly developed energy based method. Examples are presented to demonstrate the application of the proposed approach.

In this paper, an analytical energy based method is proposed to determine the optimal orientation of orthotropic materials under static loading. Instead of assuming the strain or stress is fixed with respect to orientational variables, the dependency of strain and stress fields on material orientation is explored by introducing an energy factor in the inclusion model. From the derivations, the strain based method and the stress based method can be recovered and their limitations are discussed. Numerical examples from these methods are presented and compared.

Modal analysis of coupled acoustic-structural systems leads to unsymmetric eigenproblem of special form which introduce different left and right eigenvectors. In this paper, the relation between left and right eigenvectors is first established by symmetrization of the unsymmetric eigensystem, and then Nelson’s method is extended to coupled acoustic-structural systems for calculating the sensitivities of the eigenvalues and eigenvectors. The method only needs to calculate the sensitivities of the right eigenvectors and can treat the Helmholtz resonance mode naturally. Numerical examples of an acoustic box model solved by the proposed approach are compared with finite difference approach and good agreement is noted.