A three-stage deep-learning-based method for crack detection of high-resolution steel box girder image

Ying Zhou,Shiqiao Meng,Zhiyuan Gao,Bin He,Qingzhao Kong 국제구조공학회 2022 Smart Structures and Systems, An International Jou Vol.29 No.1

Crack detection plays an important role in the maintenance and protection of steel box girder of bridges. However, since the cracks only occupy an extremely small region of the high-resolution images captured from actual conditions, the existing methods cannot deal with this kind of image effectively. To solve this problem, this paper proposed a novel three-stage method based on deep learning technology and morphology operations. The training set and test set used in this paper are composed of 360 images (4928 × 3264 pixels) in steel girder box. The first stage of the proposed model converted highresolution images into sub-images by using patch-based method and located the region of cracks by CBAM ResNet-50 model. The <i>Recall</i> reaches 0.95 on the test set. The second stage of our method uses the Attention U-Net model to get the accurate geometric edges of cracks based on results in the first stage. The <i>IoU</i> of the segmentation model implemented in this stage attains 0.48. In the third stage of the model, we remove the wrong-predicted isolated points in the predicted results through dilate operation and outlier elimination algorithm. The <i>IoU</i> of test set ascends to 0.70 after this stage. Ablation experiments are conducted to optimize the parameters and further promote the accuracy of the proposed method. The result shows that: (1) the best patch size of sub-images is 1024 × 1024. (2) the CBAM ResNet-50 and the Attention U-Net achieved the best results in the first and the second stage, respectively. (3) Pre-training the model of the first two stages can improve the <i>IoU</i> by 2.9%. In general, our method is of great significance for crack detection.

Study on vibration energy characteristics of vehicle-track-viaduct coupling system considering partial contact loss beneath track slab

Linya Liu,Zhiyuan Zuo,Qinyue Zhou,Jialiang Qin,Quanmin Liu 국제구조공학회 2020 Structural Engineering and Mechanics, An Int'l Jou Vol.75 No.4

CA mortar layer disengagement will give rise to the overall structural changes of the track and variation in the vibration form of the ballastless track. By establishing a vehicle-track-viaduct coupling analysis and calculation model, it is possible to analyze the CRTS-I type track structure vibration response while the track slab is disengaging with the power flow evaluation method, to compare the two disengaging types, namely partial contact loss at one edge beneath track slab and partial contact loss at midpoint beneath track slab. It can also study how the length of disengaging influences the track structures vibration power. It is showed that when the partial contact loss beneath track slab, and the relative vibration energy level between the rail and the track slab increases significantly within [10, 200]Hz with the same disengaging length, the partial contact loss at one edge beneath track slab has more prominent influence on the vibration power than the partial contact loss at midpoint beneath track slab. With the increase of disengaging length, the relative vibration energy level of the track slab grows sharply, but it will change significantly when it reaches 1.56 m. Little effect will be caused by the relative vibration energy level of the viaduct. The partial contact loss beneath the track slab will cause more power distribution and transmission between the trail and track slab, and will then affect the service life of the rail and track slab.

Dye-Sensitized-Assisted, Enhanced Photocatalytic Activity of TiO2/Bi4V2O11

Mengjun Liang,Zhiyuan Yang,Ying Mei,Haoran Zhou,Shuijin Yang 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2018 NANO Vol.13 No.3

In this study, the TiO2/Bi4V2O11 nanocomposite photocatalysts were prepared by loading different amount of TiO2 nanoparticles onto the surface of Bi4V2O11 nanospheres via a facile hydrothermal method. Afterwards, the as-synthesized samples were characterized by high-resolution transmission electron microscopy (HRTEM), X-ray diffraction (XRD), N2 adsorption–desorption isotherms, X-ray photoelectron spectroscopy (XPS), UV-Vis diffuse reflectance spectroscopy (DRS) and photocurrent techniques. The optimal TiO2/Bi4V2O11 composite with 20 wt.% TiO2 loading (TB2) exhibited the best photocatalytic activity, which could degrade almost RhB completely within 30 min under visible light irradiation. The enhanced photocatalytic activity of TiO2/Bi4V2O11 composites for RhB degradation could be mainly ascribed to the efficient charge separation over dye-induced sensitized and the increased specific surface area. Also, the photocatalytic activities of TiO2/Bi4V2O11 for CIP degradation were tested. After five consecutive recycling experiments, the photocatalytic degradation activity of TB2 could still reach 99% which indicated that the catalysts had superior stability. Based on the experimental and bandgap calculations, a possible photocatalytic mechanism of TiO2/Bi4V2O11 for RhB degradation was proposed.

Characterization and functional analysis of Krtap11-1 during hair follicle development in Angora rabbits (Oryctolagus cuniculus)

Shuang Liang,Zhiyuan Bao,Bohao Zhao,Tong Zhou,Jiali Li,Ming Liu,Shuaishuai Hu,Naisu Yang,Yang Chen,Xinsheng Wu 한국유전학회 2020 Genes & Genomics Vol.42 No.11

Background Keratin-associated protein (KAP), the structural protein molecule of hair fibers, plays a key role in determiningthe physical properties of hair. Studies of Krtap11-1 have focused only on its localization. Functional studies of Krtap11-1in hair follicle development have so far not been reported. Objective This study aimed to provide evidence for the role of Krtap11-1 in skin and hair development. Methods Full-length cloning and analysis of Krtap11-1 were conducted to ascertain its function. Overexpression vectors andinterference sequences were constructed and transfected into RAB-9 cells. Quantitative real-time polymerase chain reaction(qRT-PCR) was used to investigate the hair follicle developmental stage of Krtap11-1, the expression of different tissues,and the effects on other hair follicle development-related genes. Results The full length of cloned Krtap11-1 was 947 bp. Krtap11-1 was confirmed to be a hydrophilic protein localizedmostly in mitochondria. The greatest mRNA expression was observed in skin. Using a follicle synchronization model, itwas found that Krtap11-1 mRNA expression levels first increased then decreased over the passage of time, principally duringhair follicle catagen and telogen. Following the overexpression of Krtap11-1, mRNA expression levels of the WNT-2,KRT17, BMP-2, and TGF-β-1 genes increased, and LEF-1 decreased (P < 0.05), the converse after the corresponding useof si-RNA interference. Conclusions Krtap11-1 exerts a promoting effect. The results provide novel insight into the relationship between hair follicledevelopment and Krtap11-1 gene expression.

INFLUENCE OF INLET WATER INJECTION ON ENERGY CONSERVATION AND EMISSION OF GASOLINE ENGINE

Xu Jiangtao,Zhou Zhiyuan,Jiang Liyi,Zhou Haojie,Zhang Chuan 한국자동차공학회 2023 International journal of automotive technology Vol.24 No.4

Increased compression ratio of auto engine can effectively improve thermal efficiency. However, the risk of engine knock becomes higher when increasing the intake boosting. In this paper, the role of an inlet Water Injection (WI) system in improving the performance of a spark ignition engine was investigated, which was through a comparative study of Miller cycle with electromagnetic intake valve train (EMIT). The numerical simulation method was developed in AVL BOOST based on the engine test rig, and then the port water injection modelling was introduced. The results showed that when the engine speed was lower than 1800 r/min, the water spray scheme had a better effect on the engine performance as compared with the Miller cycle, and such advantage was increasingly significant with the decrease of the speed. This is due to the fact that the water injection takes into account the temperature reduction in the cylinder. When the engine speed was over 1800 r/min, it had a negative impact on engine performance with IWI due to the excessive suppression of combustion. This study provides a theoretical basis for design and research of gasoline engines

Analog-Assisted Digital Capacitorless Low-Dropout Regulator Supporting Wide Load Range

Tang, Nghia,Tang, Yangyang,Zhou, Zhiyuan,Nguyen, Bai,Hong, Wookpyo,Zhang, Philipp,Kim, Jong-Hoon,Heo, Deukhyoun Institute of Electrical and Electronics Engineers 2019 IEEE transactions on industrial electronics Vol.66 No.3

<P>Capacitorless (CL) low-dropout regulators (LDO) have gained significant research interest for point-of-load voltage regulation without off-chip capacitors. While analog CL-LDOs can deliver superior power supply rejection (PSR), digital CL-LDOs are more scalable and efficient. To achieve the advantages of both types, this paper presents a digital CL-LDO with an analog PSR enhancer, delivering strong PSR without compromising scalability and efficiency. Load regulation is performed by an asynchronous digital feedback controller for fast transient response and scalable load drivability. PSR is achieved by a load-insensitive wide-bandwidth analog controller. A prototype chip of the analog-assisted digital CL-LDO is fabricated in a 130-nm CMOS process with an active area of 0.0645 mm<SUP>2</SUP> , supporting load current up to 50 mA at nominal 1-V input and 0.8-V output. The measured PSR is better than –20 dB for frequencies up to 10 MHz, and the measured current efficiency peaks at 99.3%, with average current efficiency of 96.7% across 50× load range. The measured transient response to a full load step, with two values of load capacitance (100 pF and 10 nF), demonstrates the LDO's stable operation over a wide range of load resistance and capacitance.</P>

Characteristics of La_2O_3―Y_2O_3―Mo cermet cathode with RE_2O_3 nano particles

Jinshu Wang,Wei Liu,Zhiyuan Ren,Fan Yang,Yiman Wang,Yucheng Du,Meiling Zhou 한국물리학회 2011 Current Applied Physics Vol.11 No.3

The secondary electron emission property and microstructure of La_2O_3―Y_2O_3―Mo cermet cathode have been studied. It shows that the cathode prepared by Sol―Gel doping method has fine microstructure containing rare earth oxide (RE_2O_3) nanoparticles and uniform distribution of different substances. Auger Electron Spectroscopy (AES) depth profile result shows that an RE_2O_3 layer about 28 nm in thickness could be formed on the cathode surface, which plays an important role in the emission. Pre-activation of the cathode is favorable for the improvement of emission property. La_2O_3―Y_2O_3―Mo cathode preactivated exhibits good secondary emission property. The secondary emission yield could reach 5.24,about 1.8 times higher than that of original cathode. The enhancement on the conductivity of materials resulting from the pre-activation is favorable for the replenishment and transport of electrons, thus the secondary emission property of the cathode could be improved.

Operation of Energy and Regulation Reserve Markets in the presence of Virtual Power Plant Including Storage System and Distributed Generation based on Unit Commitment Model

Zhu Jian,Zhao Zhiyuan,Yao Xiaoqiang,Wang Huan,Chen Canzhang,Zhou Jun 대한전기학회 2024 Journal of Electrical Engineering & Technology Vol.19 No.4

The operation model of a virtual power plant (VPP) that includes synchronous distributed generating units, combined heat and power unit, renewable sources, small pumped and thermal storage elements, and electric vehicles is described in the present research. The VPPs are involved in the day-ahead energy and regulation reserve market so that escalate their profi t by selling their generated power. This is formulated as an optimization problem with maximization of VPPs profi t subject to constraints of the VPP’s sources and storage, and VPP fl exibility limits. Also, uncertain nature of renewables output power, prices of the markets, electric vehicles parameters, and reserve parameters are taken into account. Then, uncertain parameters are properly modeled by incorporating the Unscented transformation (UT)-based stochastic optimization, and GAMS software is adopted to test the effi cacy of the presented approach so that the VPP’s operation and economic situation is suitably improved.

Preparation and Photoelectric Properties of Silver Nanowire/ZnO Thin Film Ultraviolet Detector

Zhenfeng Li,Wei Xiao,Hongzhi Zhou,Zhiyuan Shi,Rongqing Li,Jia Zhang,Yang Li,Peng He,Shuye Y. Zhang 대한금속·재료학회 2023 ELECTRONIC MATERIALS LETTERS Vol.19 No.5

Ultraviolet (UV) detectors have important applications in many fi elds. ZnO is an excellent semiconductor material for the preparation of UV detectors because of its large direct gap in forbidden bandwidth, its intrinsic response band in the UV region, and its high exciton binding energy. In this paper, high-performance ZnO thin fi lms with the optically advantageous nonpolar structure were prepared by using an atomic layer deposition, and the dominant crystal plane gradually changes from the amorphous phase to the (100) crystal plane. The conventional photoconductor structure ZnO UV detector was enhanced by the surface plasmon exciton eff ect of Ag nanostructure. When the operating voltage is 5 V and the response light is 350 nm, there is a maximum optical responsiveness of up to 131 A/W. The UV/visible rejection ratio can reach 1824 times. When the ZnO thin fi lm deposition thickness is 400 deposition cycles and about 72 nm, the ZnO thin fi lm UV detector obtains the highest responsiveness (5 V, 365 nm) of 365 A/W. Comparing the photovoltaic performance of the ZnO thin-fi lm detector with the enhanced ZnO thin-fi lm detector and its optimal response wavelength, it is found that the enhanced ZnO thin-fi lm detector increased the photoresponse value by about 100 times. The optimal response wavelength in the UV region is blueshifted, and the UV-visible rejection ratio and optical response rate are signifi cantly improved.

TGF-β1/IL-11/MEK/ERK signaling mediates senescence-associated pulmonary fibrosis in a stress-induced premature senescence model of Bmi-1 deficiency

Haiyun Chen,Jialong Liang,Xin Gu,Jiawen Zhou,Chunfeng Xie,Xianhui Lv,Rong Wang,Qing Liu,Zhiyuan Mao,Haijian Sun,Guoping Zuo,Dengshun Miao,Jianliang Jin 생화학분자생물학회 2020 Experimental and molecular medicine Vol.52 No.-

To study whether TGF-β1/IL-11/MEK/ERK (TIME) signaling mediates senescence-associated pulmonary fibrosis (SAPF) in Bmi-1-deficient (Bmi-1−/−) mice and determines the major downstream mediator of Bmi-1 and crosstalk between p16INK4a and reactive oxygen species that regulates SAPF, phenotypes were compared among 7-week-old p16INK4a and Bmi-1 double-knockout, N-acetylcysteine (NAC)-treated Bmi-1−/−, Bmi-1−/−, and wild-type mice. Pulmonary fibroblasts and alveolar type II epithelial (AT2) cells were used for experiments. Human pulmonary tissues were tested for type Ι collagen, α-smooth muscle actin (α-SMA), p16INK4a, p53, p21, and TIME signaling by using enzyme-linked immunosorbent assay (ELISA). Our results demonstrated that Bmi-1 deficiency resulted in a shortened lifespan, ventilatory resistance, poor ventilatory compliance, and SAPF, including cell senescence, DNA damage, a senescence-associated secretory phenotype and collagen overdeposition that was mediated by the upregulation of TIME signaling. The signaling stimulated cell senescence, senescence-related secretion of TGF-β1 and IL-11 and production of collagen 1 by pulmonary fibroblasts and the epithelial-to-mesenchymal transition of AT2 cells. These processes were inhibited by anti-IL-11 or the MEK inhibitor PD98059. NAC treatment prolonged the lifespan and ameliorated pulmonary dysfunction and SAPF by downregulating TIME signaling more than p16INK4a deletion by inhibiting oxidative stress and DNA damage and promoting ubiquitinproteasome degradation of p16INK4a and p53. Cytoplasmic p16INK4a accumulation upregulated MEK/ERK signaling by inhibiting the translocation of pERK1/2 (Thr202/Tyr204) from the cytoplasm to the nucleus in senescent fibroblasts. The accumulation of collagen 1 and α-SMA in human lungs accompanied by cell senescence may be mediated by TIME signaling. Thus, this signaling in aging fibroblasts or AT2 cells could be a therapeutic target for preventing SAPF.