Combination algorithm for cracked rotor fault diagnosis based on NOFRFs and HHR

Yang Liu,Yulai Zhao,Jiyuan Han,Qingyu Meng,Hongliang Yao 대한기계학회 2019 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.33 No.4

In this paper, a combination algorithm for diagnosing rotor crack fault is presented. Firstly, the nonlinear output frequency response functions (NOFRFs) are used to analyze the severity of crack damage in the rotor system qualitatively. The NOFRFs are obtained by processing the vibration signal through the nonlinear output frequency response functions. Further analysis of the NOFRFs can determine the crack depth qualitatively. Secondly, the position of the crack is then located using the crack position index (CPI) l based on the higher harmonic response (HHR) and the dynamic compliance matrix. The simulation and experimental results show that the G 2 (j2w F ) in NOFRFs is very sensitive to crack depth, and the crack position index (CPI) l can determine the shaft segment effectively where the crack is located. The advantage of this combination algorithm is that it can detect the crack faults by measuring the vibration signal of the cracked rotor at two speeds, which makes the measurement process more simplified and reduces the measurement time for real-time monitoring. At each speed only the vibration response of the two nodes need to be measured, which greatly reduces the number of sensor used in the measurement process and reduces the cost of monitoring. The combination algorithm can diagnose cracked rotor faults effectively and has certain application value in the diagnosis of cracked rotor fault.

An Improved Harris-SIFT Algorithm Based on Rotation-invariant LBP Operator

Lei Yang,Yanyun Ren,Jiyuan Cai,Huosheng Hu 보안공학연구지원센터 2016 International Journal of Signal Processing, Image Vol.9 No.6

Feature-points matching is an important concept in binocular stereo vision. The procession of multi-scale feature-points matching in classical Harris-SIFT algorithm is time-consuming and has high complexity when describing the feature-points. This paper proposed a new improved Harris-SIFT algorithm based on rotation-invariant LBP (Local binary patterns) operator. Firstly, the Harris operator is used to extract feature points from DOG (Difference of Gaussian) scale space. Then, the dominant direction of feature point is calculated and 81-dimensional rotation-invariant LBP descriptors are extracted when the rotation matching window is coordinated to this direction. At last, Best-Bin-First (BBF) algorithm is used to search the matching points between the two sets of feature points. Experimental results show that the proposed algorithm is lower time-consuming than classical Harris-SIFT algorithm and remains the similar matching correct rate.

Effects of dye etching on the morphology and performance of ZnO nanorod dye-sensitized solar cells

Yu Lin,Jiyuan Yang,Yongming Meng 한국화학공학회 2013 Korean Journal of Chemical Engineering Vol.30 No.11

Dye-sensitized solar cells based on electrodeposited ZnO nanorod arrays were fabricated and tested. Fieldemission scanning electron microscopy (FESEM) and X-ray powder diffraction (XRD) were used to identify the characters of ZnO nanorod arrays. The effects of dye etching on the morphology and performance of ZnO nanorod dye-sensitized solar cells were studied. It was found that the surfaces of ZnO nanorods were both etched by dye solutions, no matter N3 or N719. Compared with N3, N719 had a larger damage to the structure of ZnO nanorod photoanode, and the photoelectric conversion efficiency of cells decreased quickly with the sensitizing time increasing. In a certain range, the increasing length of ZnO nanorods can clearly improve the photoelectric conversion efficiency of cells.

Assessment of the relative tectonic activity of the Longxian–Baoji Fault Zone in the northeastern Tibetan Plateau based on geomorphic indices

Qi Huang,Xiaohu Zhou,Jiyuan You,Shuaishuai Xu,Lushan Liu,Yang Wang 한국지질과학협의회 2023 Geosciences Journal Vol.27 No.6

Since the Late Cenozoic, tectonic deformation has been intense in the Longxian–Baoji Fault Zone (LBFZ), which is at the intersection of the southwest margin of the Ordos Block, the northeast margin of the Tibet Plateau, and the Qinling Orogenic Belt. To evaluate the relative tectonic activity within the LBFZ and discuss the influence of the northeastward expansion of the Tibetan Plateau on the geomorphological evolution of the LBFZ, we extracted data of the Qianhe, Hengshuihe, and Jinlinghe River Basins from the ASTER GDEM and analyzed the geomorphic indices, including the hypsometric integral (HI), standardized stream length-gradient index (SL/K) and Hack profile, elongation ratio (Re), the drainage basin asymmetry factor (AF) and valley floor width-to-height ratio (VF). Through geomorphic indices and field investigations, we found that the LBFZ has experienced relatively high tectonic activity. Combined with the index of relative active tectonics (IAT), we compared the tectonic activity strengths of the four major faults in the study area. Among them, the tectonic activities of the Longxian-Qishan Fault (LQF) and the Taoyuan-Guichuansi Fault (TGF) are the highest. The morphology and AF values of the drainage basin of the southwest side of the study area indicate the influence of northwest-southeast compressive stress. The northeastward expansion of the Tibetan Plateau affected the LBFZ region, and the stress brought about by it controlled the tectonic deformation in the region and sculpted the modern landscape. This study is of great significance for understanding the impact of the northeastward expansion of the Tibetan Plateau on the geomorphological evolution of the LBFZ.

Effects of 3D contraction on pebble flow uniformity and stagnation in pebble beds

Wu, Mengqi,Gui, Nan,Yang, Xingtuan,Tu, Jiyuan,Jiang, Shengyao Korean Nuclear Society 2021 Nuclear Engineering and Technology Vol.53 No.5

Pebble flow characteristics can be significantly affected by the configuration of pebble bed, especially for HTGR pebble beds. How to achieve a desired uniform flow pattern without stagnation is the top priority for reactor design. Pebbles flows inside some specially designed pebble bed with arc-shaped contraction configurations at the bottom, including both concave-inward and convex-outward shapes are explored based on discrete element method. Flow characteristics including pebble retention, residence-time frequency density, flow uniformity as well as axial velocity are investigated. The results show that the traditionally designed pebble bed with cone-shape bottom is not the most preferred structure with respect to flow pattern for reactor design. By improving the contraction configuration, the flow performance can be significantly enhanced. The flow in the convex-shape configuration featured by uniformity, consistency and less stagnation, is much more desirable for pebble bed design. In contrast, when the shape is from convex-forward to concave-inward, the flow shows more nonuniformity and stagnation in the corner although the average cross-section axial velocity is the largest due to the dominant middle pebbles.

Prediction of the remaining time and time interval of pebbles in pebble bed HTGRs aided by CNN via DEM datasets

Wu Mengqi,Liu Xu,Gui Nan,Yang Xingtuan,Tu Jiyuan,Jiang Shengyao,Qian Zhao 한국원자력학회 2023 Nuclear Engineering and Technology Vol.55 No.1

Prediction of the time-related traits of pebble flow inside pebble-bed HTGRs is of great significance for reactor operation and design. In this work, an image-driven approach with the aid of a convolutional neural network (CNN) is proposed to predict the remaining time of initially loaded pebbles and the time interval of paired flow images of the pebble bed. Two types of strategies are put forward: one is adding FC layers to the classic classification CNN models and using regression training, and the other is CNNbased deep expectation (DEX) by regarding the time prediction as a deep classification task followed by softmax expected value refinements. The current dataset is obtained from the discrete element method (DEM) simulations. Results show that the CNN-aided models generally make satisfactory predictions on the remaining time with the determination coefficient larger than 0.99. Among these models, the VGG19þDEX performs the best and its CumScore (proportion of test set with prediction error within 0.5s) can reach 0.939. Besides, the remaining time of additional test sets and new cases can also be well predicted, indicating good generalization ability of the model. In the task of predicting the time interval of image pairs, the VGG19þDEX model has also generated satisfactory results. Particularly, the trained model, with promising generalization ability, has demonstrated great potential in accurately and instantaneously predicting the traits of interest, without the need for additional computational intensive DEM simulations. Nevertheless, the issues of data diversity and model optimization need to be improved to achieve the full potential of the CNN-aided prediction tool

Evaluating Pharmacological Effects of Two Major Components of Shuangdan Oral Liquid: Role of Danshensu and Paeonol in Diabetic Nephropathy Rat

Chen, Ying,Liu, Zhuying,Zhou, Fuxing,Zhao, Hang,Yang, Qian,Li, Hua,Sun, Jiyuan,Wang, Siwang The Korean Society of Applied Pharmacology 2016 Biomolecules & Therapeutics(구 응용약물학회지) Vol.24 No.5

Shuangdan oral liquid (SDO) containing radix Salviae miltiorrhizae (Chinese name Danshen) and cortex moutan (Chinese name Mudanpi) is a traditional Chinese medicine using for treating vascular diseases. Danshensu (DSS) is a main effective monomer composition derived from radix Salviae miltiorrhizae and paeonol (Pae) from cortex moutan. Although the two herbs are widely used in traditional Chinese medicine, the pharmacological functions of their active compositions were not reported. Therefore, the research of DSS and Pae in mechanisms and pharmacodynamics interaction can provide scientific evidence to support clinical application. The diabetic nephropathy (DN) rats which were induced by streptozotocin (STZ) were treated with SDO, DSS, Pae, and DSS+Pae for eight weeks. The positive effects on DN animal models were investigated by detection of physiological and biochemical indexes and oxidative stress markers, within five treatments: SDO, DSS, Pae, DSS+Pae and insulin group. Compared with the model group, the DSS+Pae group improved the renal function, blood lipid metabolism and blood viscosity, increased the vitality of T-SOD or T-AOC and decreased the level of MDA or NO after the treatment. The study was successfully showed that the DSS+Pae group could delay the process of DN, especially in the renal injury part of histopathology changes. Our results suggest that the co-administration of DSS and Pae significantly may play a protective role in DN rats through decreasing the oxidative stress and improving the blood lipid metabolism mechanisms.

Evaluating Pharmacological Effects of Two Major Components of Shuangdan Oral Liquid: Role of Danshensu and Paeonol in Diabetic Nephropathy Rat

( Ying Chen ),( Zhuying Liu ),( Fuxing Zhou ),( Hang Zhao ),( Qian Yang ),( Hua Li ),( Jiyuan Sun ),( Siwang Wang ) 한국응용약물학회 2016 Biomolecules & Therapeutics(구 응용약물학회지) Vol.24 No.5

Shuangdan oral liquid (SDO) containing radix Salviae miltiorrhizae (Chinese name Danshen) and cortex moutan (Chinese name Mudanpi) is a traditional Chinese medicine using for treating vascular diseases. Danshensu (DSS) is a main effective monomer composition derived from radix Salviae miltiorrhizae and paeonol (Pae) from cortex moutan. Although the two herbs are widely used in traditional Chinese medicine, the pharmacological functions of their active compositions were not reported. Therefore, the research of DSS and Pae in mechanisms and pharmacodynamics interaction can provide scientific evidence to support clinical application. The diabetic nephropathy (DN) rats which were induced by streptozotocin (STZ) were treated with SDO, DSS, Pae, and DSS+Pae for eight weeks. The positive effects on DN animal models were investigated by detection of physiological and biochemical indexes and oxidative stress markers, within five treatments: SDO, DSS, Pae, DSS+Pae and insulin group. Compared with the model group, the DSS+Pae group improved the renal function, blood lipid metabolism and blood viscosity, increased the vitality of T-SOD or T-AOC and decreased the level of MDA or NO after the treatment. The study was successfully showed that the DSS+Pae group could delay the process of DN, especially in the renal injury part of histopathology changes. Our results suggest that the co-administration of DSS and Pae significantly may play a protective role in DN rats through decreasing the oxidative stress and improving the blood lipid metabolism mechanisms.