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Quzhou, China

Lv C.-Z.,Quzhou College
2011 International Conference on Electrical and Control Engineering, ICECE 2011 - Proceedings | Year: 2011

Ancient building protection conducted in different place was an effective method for the ancient building protection. There were abundant ancient buildings in Longyou city. The ancient building structures in Longyou city were surveyed by using the traditional method. Their level control points were surveyed by using fourth-order leveling. Their distances and angles were surveyed by using ordinary leveling survey. Their wall painting, texture and bedding plane construction technology were surveyed by using close photography. Their brick carving, stone carving and wood carving were surveyed by using 3-D laser scanning. All of these measures realized the ancient buildings protection in different place. A lot of real data were gained by the leveling surveying, control surveying and detail surveying applied to the ancient building in Longyou city. The data were deal with error analysis and the ancient building construction drawings were restored with computer aided design. The project could provide an engineering reference for other ancient building protection which conducted in different place. © 2011 IEEE. Source


Zhang Y.-L.,Quzhou College
Reneng Dongli Gongcheng/Journal of Engineering for Thermal Energy and Power | Year: 2016

To reveal in-depth the transient response characteristics of a centrifugal pump when it has a drastic fluctuation of the rotating speed, set up was a circulating pipeline system, including a set of low specific speed centrifugal pump. According to the function defined by users themselves, sliding mesh method and RNG k-ε turbulent flow model, an unsteady flow self-coupling numerical calculation was performed of the whole system. It has been found that the flow rate response lags behind the rotating speed variation course while the head response features a relatively good nature to follow up the rotating speed variation. The interference between the rotor and stator inside the turbomachinery exercises a most notable influence on the pressure at the outlet of the pump in the stage of the rotating speed acceleration and the pressure at the inlet of the pump in the stage of the rotating speed deceleration, however, exerts a relatively small influence on the flow rate and the power needed by the impeller. The evolution of the transient flow field in the process of the fluctuation in the rotating speed totally lags behind the quasi-steady state calculation results. The forgoing can offer important reference for revealing the transient response characteristics of a centrifugal pump. © 2016, Harbin Research Institute. All right reserved. Source


Lv M.-L.,Quzhou College | Lu Z.-M.,Zhejiang University
Information Technology Journal | Year: 2011

Perceptual hashing has been proved to be an effective solution for multimedia indexing, authentication or watermarking. Traditional perceptual hashing schemes are typical designed only for one purpose. This study presents a multipurpose image-hashing scheme based on Mean-Removed Vector Quantization (MRVQ) for both copyright protection and content authentication. The main idea is to perform MRVQ on the original image to yield two index tables, one for copyright protection and the other for content authentication. The original gray-level image is first divided into non-overlapping small blocks. The mean value for each block is calculated and quantized by the scalar quantizer to get a mean index and the quantized mean is removed from the image block to obtain the residual vector that is further quantized by the vector quantizer to obtain the residual index. All obtained mean indices constructed the mean index table and all obtained residual indices construct the residual index table. The obtained two index tables are then transformed into two intermediate binary images based on two different mapping functions, respectively. One mapping function is based on the variance of indices in a 3 ×3 neighborhood and the other mapping function is based on the number of indices larger than the mean of indices in a 3 ×3 neighborhood. Finally, the authentication mark and permuted copyright logo are respectively XOR-ed with the two intermediate binary images to obtain final authentication and protection fingerprints. Experimental results demonstrate the effectiveness of the proposed scheme. © 2011 Asian Network for Scientific Information.. Source


Lv M.L.,Quzhou College | Lu Z.-M.,Zhejiang University
Information Technology Journal | Year: 2011

This study presents a new multipurpose image hashing scheme based on Block Truncation Coding (BTC). Vector Quantization (VQ) and BTC are both block-based lossy image compression techniques for gray-level images, but BTC can maintain the mean and standard deviation after compression. In our scheme, the original gray-level image is first partitioned into non-overlapping small blocks. BTC is then performed on each block to yield two mean values, i.e., a lower mean and a higher mean, as well as a bit plane. The relationship between two mean values are utilized to generate the intermediate binary image for copyright protection, while the number of '1' s in the bit plane is compared with a threshold to generate the intermediate binary image for content authentication. Finally, the authentication mark and permuted copyright logo are respectively XOR-ed with the two intermediate binary images to obtain final authentication and protection fingerprints. Because BTC is a fast encoding scheme, our proposed method is therefore with lower complexity compared to VQ-based multipurpose image hashing schemes. Experimental results demonstrate the effectiveness and efficiency of the proposed scheme. © 2011 Asian Network for Scientific Information. Source


Feng L.,Quzhou College
Advanced Materials Research | Year: 2012

The Non-uniform rational B-spline (NURBS) is widely used in CAD/CAM/CNC. The NURBS interpolation is crucial for an advanced CNC system compatible with NURBS. Classic NURBS interpolation algorithms always do not well consider both the contour precision and feedrate smoothness. This paper proposes a NURBS interpolation algorithm based on the feedrate sensitive points identification. The feedrate sensitive points is found out according to the chord error which is relative to the feedrate passing this point. Furthermore, the feedrate profile is adaptively planned between two adjacent sensitive points according to the distance between them. The feedrate profile of the whole NURBS can be connected with these feedrate sections. A cubic NURBS curve is adopted to evaluate the interpolation algorithm. Simulation results show that the proposed interpolation algorithm is available with reference value for industrial application. Source

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