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The serviceability limit state of structures is subject to increasing attention. Flooring-systems may encounter vertical vibrations that may be perceived as annoying by stationary persons sitting or standing on the structure. This paper looks into human induced floor vibration of a 33-storey residential building by using theoretical analysis and in-situ inspection. The results show that though the vertical eigenfrequency of the floor satisfies the demand of vibration comfort stated in the Technical Specification for Concrete Structures of Tall Buildings (JGJ3-2010), the maximum value of vertical vibration of the floor system is excessively large, which is caused by the stiffness shortage of the floor due to the decreased floor thickness.

In this paper, based on the Midas/gen platform, a three-dimensional finite element model (FEM) for a transfinite stadium with a large-span and large-cantilever roof , located in Shenyang, was used to study its potential responses to seismic activities. In the numerical analysis, an earthquake spectrum stipulated by the Chinese Seismic Code (GB50011-2010) was adopted to calculate the bidirectional horizontal displacements by the Complete Quadratic Combination (CQC) method on the basis of the response spectrum analysis. The computational results indicate that the maximum displacements in both of the two horizontal directions locate at the top of this structure, i.e. the transfinite part of the roof.

For floor serviceability, stiffness and resonance are dominant consideration in the design of long-span floor systems or large-cantilever floor systems, which usually have lower stiffness and smaller dampings. In this paper, a dynamic characteristics test of long-span cantilevered floor systems in Shenyang Culture & Art Center was performed by using pulsating methods to determine the natural frequencis and the dampings, which were compared with those from the numerical modal analysis based on the Midas/gen platform. The research provides a basis for a further study of floor vibrations due to human comfort.

A Mechanical model of impact and contact between the ball and re-circulating mechanism in ball screw was brought forward according to the Hertz contact model and classical impact theory, along with the joint relationship of re-circulating mechanism and nut taken into account. Then the formula of the impact force and contact time was induced, which the elastic coefficient of restitution was considering in contact time calculation. Moreover, a special test unit was designed for contact time measurement and the contact time was measured. The result indicates that the new model proposed in this paper is closer to the practical situation than the old model proposed in literature. Based on works mentioned above, the influence of impact angle, parameters of structure and material on impact force was analyzed by numerical simulation.

To reflect the relationship between the trapping effect and colorimetric value of prints, this paper establishes an algorithm to calculate the ink trapping ratio. The new algorithm assumed that the second ink of two-color overprint solid forms an evenly distributed and thinner ink layer by keeping the total ink volume as constant and it employed the transmittance of single solid ink and overprint solid to compute the ratio of the thickness of the second ink layer printed on the first ink layer and on the blank paper on basis of Lambert's law. Because of the difficulties of measuring the transmittance of prints, it used the Clapper-Yule model to calculate them. To evaluate it, the ink trapping ratio computed by the densitometry method and the new algorithm for two sets of two-color overprint solid were adopted to predict the spectral reflectance of them. By comparing the CIELAB color difference between the calculated and measured value of spectral reflectance, the proposed new algorithm is precisely defined and it improves the calculation accuracy of ink trapping.

A wind-driven feeding mechanism of high efficiency is designed according to the TRIZ theory and its mechanical structure innovative design based on the principle of energy conversion. It aims at delivering of small granular, cylindrical, flakes and other materials in machinery, pharmaceuticals, electronics and other industries by transmission mechanism such as the typical gear mechanism and linkage mechanism. The prototype is produced combined with the specific parameters of the common materials. The modular innovative design is adopted, including the transmission module, driver module and material feeding module. By the inspection of the actual operation, each design module of the produced prototype is stable and reliable. At the same time the effect of material transportation is good.

Optical dot gain is the key point of halftone reconstruction study, and has always been a meaningful topic of theoretical study. The Yule–Nielsen formula is by far the most widely used research method of optical dot gain. However, solving the Yule–Nielsen parameter n remains a difficult problem. This paper disregards solving for the Yule–Nielsen parameter n, analyzes the light scattering and osmotic effect of halftone presswork, deduces the exact expressions of blank area of presswork, and determines the reflectivity of the dot part and halftone presswork according to the point spread function and probability method. Furthermore, this paper analyzes how the optical dot gain depends on the dot area coverage of presswork, ink layer transmittivity, and paper-based spectral reflectivity. In addition, a new algorithm model for optical dot gain is established. By employing the Clapper–Yule Model to calculate the spectral transmittance of printing ink and comparing it with the practical measured spectral reflectivity of the halftone presswork proof, the accuracy of the model established in this paper is fully verified.

One of the fundamental problems in scientific computing is to find solutions for linear equation systems. For finite element problem, Cholesky factorization is often used to solve symmetric positive definite matrices. In this paper, Cholesky factorization is massively parallelized and three different optimization methods - highly parallel factorization, tile strategy and memory scheduling are used to accelerate Cholesky factorization effectively. A novel algorithm using OpenCL is implemented. Testing on GPU shows that performance of the algorithm increases with the dimension of matrix, reaching 785.41GFlops, about 50x times speedup. Cholesky factorization is remarkably improved with OpenCL on GPU.