Second-order sensitivity of eigenpairs in multiple parameter structures

This paper presents methods for computing a second-order sensitivity matrix and the Hessian matrix of eigenvalues and eigenvectors of multiple parameter structures. Second-order perturbations of eigenvalues and eigenvectors are transformed into multiple parameter forms,and the second-order perturbation sensitivity matrices of eigenvalues and eigenvectors are developed.With these formulations,the efficient methods based on the second-order Taylor expansion and second-order perturbation are obtained to estimate changes of eigenvalues and eigenvectors when the design parameters are changed. The presented method avoids direct differential operation,and thus reduces difficulty for computing the second-order sensitivity matrices of eigenpairs.A numerical example is given to demonstrate application and accuracy of the proposed method.

Influence of Structure Parameters on Performance of the Thermoelectric Module

A numerical model of thermoelectric module （TEM） is created by academic analysis,and the impacts of the resistance ratio and thermoelement size on the output power and thermoelectric efficiency of the TEM are analyzed by the MATLAB numerical calculation.The numerical model is validated by the ANSYS thermal,electrical,and structural coupling simulation.The effects of the variable physical property parameters and contact effect on the output power and thermoelectric efficiency are evaluated,and the concept of aspect ratio optimal domain is proposed,which provides a new design approach for the TEM.

Numerical analysis of hydroabrasion in a hydrocyclone

The velocity profiles and separation efficiency curves of a hydrocyclone were predicted by an Euler-Euler approach using a computational fluid dynamics tool ANSYS-CFX 14.5. The Euler-Euler approach is capable of considering the particle-particle interactions and is appropriate for highly laden liquid-solid mixtures. Pre- dicted results were compared and validated with experi- mental results and showed a considerably good agreement. An increase in the particle cut size with increasing solid concentration of the inlet mixture flow was observed and discussed. In addition to this, the erosion on hydrocyclone walls constructed from stainless steel 410, eroded by sand particles （mainly SiOz）, was predicted with the Euler-La- grange approach. In this approach, the abrasive solid particles were traced in a Lagrangian reference frame as discrete particles. The increases in the input flow velocity, solid concentration, and the particle size have increased the erosion at the upper part of the cylindrical body of the hydrocyclone, where the tangential inlet flow enters the hydrocyclone. The erosion density in the area between the cylindrical to conical body area, in comparison to other parts of the hydrocyclone, also increased considerably. Moreover, it was observed that an increase in the particle shape factor from 0.1 to 1.0 leads to a decrease of almost 70 % in the average erosion density of the hydrocyclone wall surfaces.

Research on parametric design method for energy efficiency of green building in architectural scheme phase

Based on a large number of researches and engineering practices both domestic and overseas, it is shown that the building parameters to be determined during scheme phase can exert a great effect on the building energy consumption. In this paper, through a combination of the popular design method of building parameterization at present and the design goat of energy saving during the scheme phase, the author carries out researches on the design methods and toot development which are applicable to parameterization of building energy saving in this stage. In connection with the characteristics of both modeling process of parameterization and energy saving design, and by means of steady calculation as wetl as simulation, this paper establishes an simplified model to calculate the overall energy consumption of air-conditioning, heating, lighting and equipments, and ultimately gives suggestions on design of scheme for energy saving by optimization with the genetic algorithm （GA）. On the basis of the model, a software platform is developed by computer language QTand openGL interface and is oriented to the design users and sets up the MMI （human-computer interaction） software interface for parameterization of building energy saving, which achieves automatic modeling of parameterization and promotes research on oractical design cases.

Sharing Weights in Shallow Layers via Rotation Group Equivariant Convolutions

The convolution operation possesses the characteristic of translation group equivariance. To achieve more group equivariances, rotation group equivariant convolutions(RGEC) are proposed to acquire both translation and rotation group equivariances.However, previous work paid more attention to the number of parameters and usually ignored other resource costs. In this paper, we construct our networks without introducing extra resource costs. Specifically, a convolution kernel is rotated to different orientations for feature extractions of multiple channels. Meanwhile, much fewer kernels than previous works are used to ensure that the output channel does not increase. To further enhance the orthogonality of kernels in different orientations, we construct the non-maximum-suppression loss on the rotation dimension to suppress the other directions except the most activated one. Considering that the low-level-features benefit more from the rotational symmetry, we only share weights in the shallow layers(SWSL) via RGEC. Extensive experiments on multiple datasets(i.e., Image Net, CIFAR, and MNIST) demonstrate that SWSL can effectively benefit from the higher-degree weight sharing and improve the performances of various networks, including plain and Res Net architectures. Meanwhile, the convolutional kernels and parameters are much fewer(e.g., 75%, 87.5% fewer) in the shallow layers, and no extra computation costs are introduced.

Modeling of aggregation kernels for fluidized beds using discrete particle model simulations

Aggregation is one of the many important processes in chemical and process engineering. Several researchers have attempted to understand this complex process in fluidized beds using the macro-model of population balance equations （PBEs）. The aggregation kernel is an effective parameter in PBEs, and is defined as the product of the aggregation efficiency and collision frequency functions. Attempts to derive this kernel have taken different approaches, including theoretical, experimental, and empirical techniques. The present paper calculates the aggregation kernel using micro-model computer simulations, i.e., a discrete particle model. We simulate the micro-model without aggregation for various initial conditions, and observe that the collision frequency function is in good agreement with the shear kernel. We then simulate the micro-model with aggregation and calculate the aggregation efficiency rate.