A Novel Wind Turbine Health Condition Monitoring Method Based on Correlative Features Domain Adaptation

Wenyi Liu,He Ren,Mirza Ali Shaheer,Jahanzeb Aslam Awan 한국정밀공학회 2022 International Journal of Precision Engineering and Vol.9 No.1

Aimed at the difficulty in fault diagnosis of wind turbine transmission system under variable working conditions, the paper proposes a novel health condition monitoring method based on correlative features domain adaptation. Firstly, the envelope analysis of the collected signals is carried out, and the time–frequency features of the signals are extracted to construct the feature set. The feature sets under the similar working conditions to target are selected as the auxiliary sample sets in source domain through the transferability evaluation. Then, a transformation matrix is found to adapt the marginal and conditional distributions of wind turbine sample data under different working conditions, and its weight is adjusted. While reducing the discrepancy between domains, the class imbalance problem is taken into consideration, so as to improve the accuracy of fault diagnosis under the target working condition. Finally, the classifier is trained with the adjusted source domain and tested in the target domain. Experiments show that the proposed method can effectively improve the accuracy of wind turbine fault diagnosis.

Research of the Influence of Single-Flow and Dual-Flow Patterns on Fuel Tank Washing Inerting Process

Wenyi Liu,Xuefei Huang,Weihua Liu 한국항공우주학회 2024 International Journal of Aeronautical and Space Sc Vol.25 No.2

The purpose of this study is that safety issues of modern aircraft always attract extensive attention worldwide. The combustion and explosion of fuel tank system is one of the main causes of aircraft accident. This paper builds a general mathematical model for a multi-compartment fuel tank and provides the initial conditions for a solution using the Runge–Kutta method according to mass conservation, the equation of nitrogen–oxygen dissolution and evolution, and the equation of gas flowing through the orifice. Nitrogen-enriched air (NEA) flow is usually used to decrease the oxygen concentration inside fuel tank to keep it below the oxygen concentration required to support combustion. With a four-compartment fuel tank as the research objective and adopting a domestic separation membrane to generate NEA, single-flow and dual-flow patterns are designed, respectively. Also, a washing inerting simulation is performed and the variation in the average oxygen concentration in the fuel tank and each compartment with the flight envelope is analyzed. The research results indicate that these two patterns can both meet the requirement that the average oxygen concentration of the upper ullage in the fuel tank should be lower than 12%. Although the single-flow pattern is simpler than the dual-flow pattern, it cannot avoid external air entering the fuel tank, which will cause the oxygen concentration in some compartments to be higher than 12% during the diving phase, while the dual-flow pattern can guarantee that the oxygen concentration of compartments does not exceed the limits during the entire flight. With the comparison between single-flow and dual-flow patterns, this study may provide some reference for the further design and study of washing inerting process for fuel inerting system.

Atractylodin induces apoptosis through downregulation of PI3Kγ-mediated PI3K/Akt/mTOR/p70S6K signalling in colon cancer cells and suppresses the tumour formation in xenograft mice model

Wenyi Lu,Jianxia Liu,Bin Wu,Shungen Huang,Jian Wang,Runda Wu,Zhongqi Mao 한국고분자학회 2024 Macromolecular Research Vol.32 No.2

This study used both in vitro and in vivo models to evaluate the efficacy of atractylodin as an anticancer treatment for colorectal cancer. The cytotoxicity of atractylodin on colon cancer cells was assessed using the MTT assay, and atractylodininduced apoptosis was determined using flow cytometry. The expression of cleaved caspase 3 and other apoptotic proteins was examined using Western blotting to determine the mechanism underlying atractylodin's anticancer activity. In addition, the role of PI3K/Akt/mTOR/p70S6K signalling in atractylodin-induced apoptosis in colon cancer cells was analyzed. The study found that atractylodin caused dose-dependent ROS-mediated apoptosis and DNA damage in colon cancer cells and activated caspase 3. Furthermore, atractylodin inhibited the PI3K/Akt/mTOR/p70S6K signalling pathway by targeting PI3Kγ in colon cancer cells. Molecular docking analysis indicated that atractylodin binds to the Akt binding pocket of PI3Kγ. The study also evaluated the antitumour effects of atractylodin on a colon cancer tumour xenograft model and found that it significantly reduced tumour growth and volume by inducing apoptosis. These results suggest that atractylodin has potential as a candidate for the treatment of colorectal cancer, although further research is necessary.

EFFECT OF TRANSFORMATION VOLUME STRAIN ON THE SPHERICAL INDENTATION OF SHAPE MEMORY ALLOYS

WENYI YAN,QINGPING SUN,HONG-YUAN LIU 한국소성가공학회 2008 한국소성가공학회 컨퍼런스 Vol.2008 No.10

Modeling and optimization of cutinase production by recombinant Escherichia coli based on statistical experimental designs

Wenyi Tao,Jianghua Li,Long Liu,Jing Wu,Jun Sun,Guocheng Du,Jian Chen 한국화학공학회 2010 Korean Journal of Chemical Engineering Vol.27 No.4

Statistics-based experiment designs were used to optimize the culture medium (glucose, yeast extract, IPTG,tween-60, and CaCl2) for cutinase production by recombinant Escherichia coli. A 25-1 fractional factorial design augmented with center points revealed that glucose, yeast extract, and IPTG were the most significant factors, whereas the other factors were not important within the levels tested. The method of steepest ascent was used to approach the proximity of optimum, followed by a central composite design to develop a response surface for culture condition optimization. The optimum culture medium for cutinase production was found to be: glucose 33. 92 g/L, yeast extract 30.92 g/L,and IPTG 0.76 g/L. A cutinase production of 145.27±1.5 U/mL, which was in agreement with the prediction, was observed in triplicate verification experiments. The results obtained here verified the effectiveness of the applied methodology and may be helpful for cutinase production on an industrial scale.

Damage of scarf-repaired composite laminates subjected to low-velocity impacts

Xiaoquan Cheng,Wenyi Zhao,Shufeng Liu,Yunyan Xu,Jianwen Bao 국제구조공학회 2014 Steel and Composite Structures, An International J Vol.17 No.2

The damage characters of scarf repaired composite laminates subjected to low-velocity impact with various energy levels at different locations are studied experimentally. The results are compared with those of the original laminates which have no initial damage and don’t need repair. The impact load-time history of the specimens, the velocity-time curves of the impactor, the post impact compressive strength of the specimens and the C-scan photographs of the damaged regions are obtained. The delamination threshold load and damage character of the specimen section at impact point are also studied. The results have shown that the impact response of a repaired composite laminate is sensitive to the location of the impact. The impact load and the delamination threshold load have shown different characters for specimens with different impact locations. The debonding characters of the adhesive and compressive strength after impact of the specimens are also influenced by impact locations.

Comparison between Craniospinal Irradiation and Limited-Field Radiation in Patients with Non-metastatic Bifocal Germinoma

Bo Li,Wenyi Lv,Chunde Li,Jiongxian Yang,Jiajia Chen,Jin Feng,Li Chen,Zhenyu Ma,Youqi Li,Jiayi Wang,Yanwei Liu,Yanong Li,Shuai Liu,Shiqi Luo,Xiaoguang Qiu 대한암학회 2020 Cancer Research and Treatment Vol.52 No.4

Purpose Whether craniospinal irradiation (CSI) could be replaced by limited-field radiation in non-metastatic bifocal germinoma remains controversial. We addressed the issue based on the data from our series and the literature. Materials and Methods Data from 49 patients diagnosed with non-metastatic bifocal germinoma at our hospital during the last 10 years were collected. The Pediatric Quality of Life Inventory 4.0 was used to evaluate health-related quality of life (HRQOL). Additionally, 81 patients identified from the literature were also analyzed independently. Results In our cohort, 34 patients had tumors in the sellar/suprasellar (S/SS) plus pineal gland (PG) regions and 15 in the S/SS plus basal ganglia/thalamus (BG/T) regions. The median follow-up period was 52 months (range, 10 to 134 months). Our survival analysis showed that patients treated with CSI (n=12) or whole-brain radiotherapy (WBRT; n=34) had comparable disease-free survival (DFS; p=0.540), but better DFS than those treated with focal radiotherapy (FR; n=3, p=0.016). All 81 patients from the literature had tumors in the S/SS+PG regions. Relapses were documented in 4/45 patients treated with FR, 2/17 treated with whole-ventricle irradiation, 0/4 treated with WBRT, and 1/15 treated with CSI. Survival analysis did not reveal DFS differences between the types of radiation field (p=0.785). HRQOL analysis (n=44) in our cohort found that, compared with S/SS+PG germinoma, patients with BG/T involvement had significantly lower scores in social and school domains. However, HRQOL difference between patients treated with CSI and those not treated with CSI was not significant. Conclusion In patients with non-metastatic bifocal germinoma, it is rational that CSI could be replaced by limited-field radiation. HRQOL in patients with BG/T involvement was poorer.

Parallel Deblocking Filter Based on Modified Order of Accessing the Coding Tree Units for HEVC on Multicore Processor

( Haiwei Lei ),( Wenyi Liu ),( Anhong Wang ) 한국인터넷정보학회 2017 KSII Transactions on Internet and Information Syst Vol.11 No.3

The deblocking filter (DF) reduces blocking artifacts in encoded video sequences, and thereby significantly improves the subjective and objective quality of videos. Statistics show that the DF accounts for 5-18% of the total decoding time in high-efficiency video coding. Therefore, speeding up the DF will improve codec performance, especially for the decoder. In view of the rapid development of multicore technology, we propose a parallel DF scheme based on a modified order of accessing the coding tree units (CTUs) by analyzing the data dependencies between adjacent CTUs. This enables the DF to run in parallel, providing accelerated performance and more flexibility in the degree of parallelism, as well as finer parallel granularity. We additionally solve the problems of variable privatization and thread synchronization in the parallelization of the DF. Finally, the DF module is parallelized based on the HM16.1 reference software using OpenMP technology. The acceleration performance is experimentally tested under various numbers of cores, and the results show that the proposed scheme is very effective at speeding up the DF.

Surface polished of bulk methylammonium lead tribromide single crystal

Zhang Hang,Zhang Bohao,Wang Xiang,Shao Wenyi,Nie Jing,Liu Jun,Ouyang Xiaoping,Xu Qiang 한국물리학회 2020 Current Applied Physics Vol.20 No.10

Organic-inorganic halide perovskite materials have been demonstrated with wide applications in optoelectronics and ionization radiation detection. For bulk as-grown crystals, the existence of surface cracks and defects can significantly increase charges recombination and reduce the performance of the device. Herein, we polished the crystal surfaces with both mechanical and chemical mechanical methods at room temperature. After been chemical-mechanical polished, the crystal surface with root mean square roughness about 0.5 nm was obtained. Optical transmission and photoluminescence spectra indicate that chemical mechanical polishing technology can effectively reduce the density of crystal surface defects. The achieved low leakage current density on the surface and bulk crystal is 0.05 nA mm 2 and 0.07 nA mm 2, respectively. Furthermore, the current-voltage curve under visible photons and X-ray photons reveals that surface polishing treatment can suppress the charges recombination and increase the charges transportation.