Rapid warning of wind turbine blade icing based on MIV-tSNE-RNN

Zhiqiang Zhang,Bin Fan,Yong Liu,Peng Zhang,Jianguo Wang,Wenliang Du 대한기계학회 2021 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.35 No.12

A fast early warning algorithm for wind turbine blade icing based on a RNN model is proposed. Through wind turbine blade history data and labels as model input, the evaluation of raw m-dimension data through mean impact value (MIV) indices eliminates data with an MIV index of less than one; the remaining n-dimension data is reduced to x-dimension by the tSNE method; dimensional data is inputted into the RNN, and the model output is the icing state of the wind turbine blade in a certain future period. Based on the SCADA data from a wind field, the model was verified by an example. Using a certain example case, if the model training data is 10 4 orders of magnitude, using the MIV-tSNE-RNN algorithm, the prediction accuracy can reach approximately 72 %; compared with the RNN model, the prediction accuracy is improved by approximately 150 % while reducing the algorithm running time by approximately 45 %. If the amount of data exceeds 10 4 orders of magnitude, using the MIVtSNE-RNN algorithm, the prediction accuracy is improved by approximately 100 %. This algorithm can provide accurate and rapid prediction results for wind turbine blade icing according to actual needs.

Multiple frequency vibration of the micro lubricating gap geometry between cylinder block and valve plate in an axial piston pump

Zhiqiang Zhang,Yuanyuan Chen,Jianli Song,Kunshan Jin,Haibo Zhou 대한기계학회 2021 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.35 No.11

Refined models of the forces in the cylinder block/valve plate system along Z axis and the moments around X and Y axes were built, considering the pressure ripple due to the piston reciprocating motions (PRM) and pressure variations in the wedge film (PVF) and the chambers (PVC) caused by the silencing slots. The multi-frequency vibration models of the gap geometry owing to the forces and moments are proposed. The dynamic mechanical balance equations are presented. The frequency spectra of the test gap thickness show the vibration amplitudes at the first three frequencies are larger than those of the other frequencies. PVF and PVC have obvious influences on the gap at the second frequency, and PRM exerts an impact at the third. The moment fluctuations around X and Y axes, bending stiffness of the shaft, and the rough surfaces contact could affect the vibration amplitude of the wedge gap geometry.

Spectroscopic study on the intermolecular interaction of SO2 absorption in poly-ethylene glycol+H2O systems

Zhiqiang He,Jinrong Liu,Jianbin Zhang,Na Zhang 한국화학공학회 2014 Korean Journal of Chemical Engineering Vol.31 No.3

Poly-Ethylene Glycol (PEG) 300+H2O solutions (PEGWs) has been used as a promising medium for theabsorption of SO2. We investigated the UV, FTIR, 1H-NMR, and fluorescence spectra in the absorption processes ofSO2 in PEGWs to present an important absorption mechanism. Based on the spectral results, the possibility of intermolecularhydrogen bond formation by hydroxyl oxygen atom in the PEG molecule with hydrogen atom in H2O andS…O interaction formation by the oxygen atoms in PEG with the sulfur atom in SO2 are discussed. This shows thatthe spectral changes may be due to the formation of -CH2CH2O(H)…HOH… and -CH2-CH2-O(CH2-CH2-)…HOH…in PEGWs and the formation of -CH2CH2OH…OSO…, and intermolecular S…O interaction between PEG and SO2as the formation of -CH2CH2OCH2CH2O(H)…(O)S(O)… and -CH2-CH2-O(CH2-CH2-)…(O)S(O)…. The existenceof these bonds benefits the absorption and desorption processes of SO2 in PEGWs.

A Review on the Books of Introduction to Publishing Science Published in China during the Past Two Decades

Zhang Zhiqiang,Xiao Chao 한국출판학회 2010 한국출판학연구 Vol.36 No.1

This paper reviews the 11 books of Introduction to Publishing Science which were published in China during the past two decades. From both the macro‐level and the micro‐level, the paper focuses on the similarities and differences of the 11 books. In the meanwhile, on the basis of the current research styles of these books and the present application of theories in other disciplines, the development trends of this kind of books are discussed in the paper.

Cultural Fusion

Zhang Zhiqiang 한국콘텐츠학회 2013 ICCC International Digital Design Invitation Exhib Vol.2013 No.-

Unite

Zhiqiang Zhang 한국콘텐츠학회 2012 ICCC International Digital Design Invitation Exhib Vol.8 No.2

Damage and failure characterization of 7075 aluminum alloy hot stamping

Zhiqiang Zhang,Yuejie Cui,Qing-Min Chen 대한기계학회 2022 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.36 No.1

7000 series high strength aluminum alloys are increasingly used in manufacturing automobile body parts to meet the more stringent demands for automobile lightweight. Hot stamping of 7000 series high strength aluminum alloys is a complex thermal-mechanical coupling process and precise simulation is needed to predict material fracture. To obtain damage model of 7075 aluminum alloy in hot stamping, five different stress triaxiality specimens were designed. The fracture strain, critical strain and average stress triaxiality of different specimens were obtained by the hybrid finite element simulation and experiment (FE-EXP) method. GISSMO model of 7075 aluminum alloy at 400 °C was established. Compared with the experimental results of U-shaped part hot stamping under different lubrication conditions, the calibrated GISSMO model was demonstrated to predict the damage behavior of 7075 aluminum alloy during high temperature deformation accurately.

Damaged and failure characterization of 7075-T6 Al alloy based on GISSMO model

Zhiqiang Zhang,Yuejie Cui,Ge Yu 대한기계학회 2021 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.35 No.3

Failure simulation of 7075-T6 Al alloy is very important due to its relatively low ductility compared to conventional steel. A hybrid numerical-experimental method was developed to determine plastic strains at fracture as a function of triaxiality. The uniaxial tension tests were performed by using the specimens including pure shear, 45° shear, smooth, R5 notch and R15 notch. The fracture locus was established by calibrating the parameters of the Hosford-Coulomb fracture model and was implemented into the GISSMO damage model. The results showed that the predicted force-displacement data were in good agreement with the experimental results. The results of the mesh dependence showed that the mesh size in the range of 0.5-5 mm did not have much influence on the damage results. To assess the accuracy of the damage model, three-point bending tests of the anti-collision beam were performed. The calibrated GISSMO damage model could accurately predict the load-displacement data.

A Study of the Concept of Publishing(Chuban) and Publishing Science(Chuban Xue) in China

Zhang Zhiqiang 한국출판학회 2006 한국출판학연구 Vol.0 No.51

This article studies the history of the concept of “Chuban”(Publishing, 出版) and Chuban Xue(Publishing Science, 出版?) in China. The article points out that, although China has an age-old publishing history, it has been using “Kan(publishing 刊)”, “Ke(publishing 刻)” and other words instead of “Chuban”(Publishing, 出版). At the end of the 19th century and the beginning of the 20th century, China accepted the concept of “Chuban”(Publishing). It showed that publishing was indeed regarded as an independent activity or cause at that time. Similarly, the history of the concept of “Chuban Xue”(Publishing Science, 出版?) was certainly not long. This article argues that the one who proposed to establish “Chuban Xue”(Publishing Science, 出版?) earliest was Chinese in the 1930s. At that time, in Tushu Nianjian (Books Almanac, ??年?) compiled by Yang Jialuo(?家?), the word of “Chuban Xue” (Publishing Science, 出版?) had already appeared. Therefore, this article also corrects the wrong viewpoint that Japanese scholars proposed the e`tablishment of “Publishing Science” in 1960s.

In vitro selection and identifcation of a cold‑tolerant variant in pineapple (Ananas comosus)

Yafen Zhang,Zhiqiang Xu,Tao Xie,Wei Zhang,Yehua He,Chaoyang Liu 한국원예학회 2022 Horticulture, Environment, and Biotechnology Vol.63 No.2

Cold stress is an important factor limiting the growth and distribution of pineapple. Breeding cold-resistant germplasm is an efective way to cope with this problem. In vitro selection for the somaclonal variation using diferent selection agents has been used for crop improvement in stress tolerance. In this study, the pineapple cold-tolerant variant was developed through in vitro cold selection of somaclonal variations. Low temperature was used as the selected agent, and the extreme lethal condition for the in vitro pineapple cultures was determined to be 0 °C for 72 h. The morphology changes of the in vitro cultures during the cold selection were observed and analyzed. The cold-tolerant variant line was fnally obtained through three consecutive selections with cold shock treatments, based on the established high-efciency culture system for pineapple embryogenic calli. The genetic variations at the molecular level in the cold-tolerant variant were verifed by ISSR analysis. The signifcantly improved cold tolerance in our selected variant was mainly refected by the higher survival rate, increased proline content, and elevated SOD activity under cold stress compared to these qualities in the control plants. This study demonstrated the feasibility of in vitro selection for cold tolerance in pineapple. The cold-tolerant variant could be valuable for future pineapple breeding programs and for cold tolerance research.