Experiment study of structural random loading identification by the inverse pseudo excitation method

Xing-Lin Guo,Dong-Sheng Li 국제구조공학회 2004 Structural Engineering and Mechanics, An Int'l Jou Vol.18 No.6

Experiment study of structural random loading identification by the inverse pseudo excitation method

Guo, Xing-Lin,Li, Dong-Sheng Techno-Press 2004 Structural Engineering and Mechanics, An Int'l Jou Vol.18 No.6

The inverse pseudo excitation method is used in the identification of random loadings. For structures subjected to stationary random excitations, the power spectral density matrices of such loadings are identified experimentally. The identification is based on the measured acceleration responses and the structural frequency response functions. Numerical simulation is used in the optimal selection of sensor locations. The proposed method has been successfully applied to the loading identification experiments of three structural models, two uniform steel cantilever beams and a four-story plastic glass frame, subjected to uncorrelated or partially correlated random excitations. The identified loadings agree quite well with actual excitations. It is proved that the proposed method is quite accurate and efficient in addition to its ability to alleviate the ill conditioning of the structural frequency response functions.

An Analysis of the Focus Variation Microscope and Its Application in the Measurement of Tool Parameter

Lin Yuan,Tong Guo,Zhongjun Qiu,Xing Fu,Xiaotang Hu 한국정밀공학회 2020 International Journal of Precision Engineering and Vol.21 No.12

Ultra-precision manufacturing is essential to the production of workpieces of the highest quality in terms of form accuracy, surface accuracy, and integrity. Compared with physical and chemical material removal methods, it has the advantages of high efficiency, high flexibility, and low cost. Because of the direct interaction between the workpiece and the tool during the process of ultra-precision manufacturing, the geometrical parameters of the tool directly affect the surface quality of the workpiece and need to be measured accurately and comprehensively. However, due to the large surface slopes of some tools, some three-dimensional measurement methods cannot measure their geometrical parameters because of limited maximum measurement angle. In this work, we build a focus variation system to make three-dimensional measurements of tools and extract their geometrical parameters. The data processing procedures and the selection of experimental parameters are analyzed in detail using simulations and experiments. Furthermore, we use a step height standard to verify the high accuracy of the measurement system and a roughened fl at surface to evaluate the measurement noise and vertical resolution. Measurements of the parameters of a round nose cutting tool and the surface texture parameters of a grinding tool are conducted and indicate that the focus variation system is suitable for measuring the geometrical parameters of tools for ultra-precision manufacturing.

Molecular characterization and inhibition analysis of the acetylcholinesterase gene from the silkworm maggot, Exorista sorbillans

( Guo Jun Lang ),( Ming Yan Zhang ),( Bao Ling Li ),( Lin Lin Yu ),( Xing Meng Lu ),( Chuan Xi Zhang ) 생화학분자생물학회 (구 한국생화학분자생물학회) 2010 BMB Reports Vol.43 No.8

Several organophosphorus (OP) insecticides can selectively kill the silkworm maggot, Exorista sorbillans (Es) (Diptera: Tachinidae), while not obviously affecting the host (Bombyx mori) larvae, but the mechanism is not yet clear. In this study, the cDNA encoding an acetylcholinesterase (AChE) from the field Es was isolated. One point mutation (Gly353Ala) was identified. The Es-353G AChE and Es-353A AChE were expressed in baculovirus- insect cell system, respectively. The inhibition results showed that for eserine and Chlorpyrifos, Es-353A AChE was significantly less sensitive than Es-353G AChE. Meanwhile, comparison of the I(50) values of eserine, dichlorvos, Chlorpyrifos and omethoate of recombinant Es AChEs with its host (Bombyx mori) AChEs indicated that, both Es AChEs are more sensitive than B. mori AChEs. The results give an insight of the mechanism that some OP insecticides can selectively kills Es while without distinct effect on its host, B. mori. [BMB reports 2010; 43(8): 573-578]

Long-term Survivals, Toxicities and the Role of Chemotherapy in Early-Stage Nasopharyngeal Carcinoma Patients Treated with Intensity-modulated Radiation Therapy: A Retrospective Study with 15-year Follow-up

Lin Wang,Jingjing Miao,Huageng Huang,Boyu Chen,Xiao Xiao,Manyi Zhu,Yingshan Liang,Weiwei Xiao,Shaomin Huang,Yinglin Peng,Xiaowu Deng,Xing Lv,Weixiong Xia,Yanqun Xiang,Xiang Guo,Fei Han,Chong Zhao 대한암학회 2022 Cancer Research and Treatment Vol.54 No.1

Purpose This study was aimed to investigate long-term survivals and toxicities of early-stage nasopharyngeal carcinoma (NPC) in endemic area, evaluating the role of chemotherapy in stage II patients. Materials and Methods Totally 187 patients with newly diagnosed NPC and restaged American Joint Committee on Cancer/ International Union Against Cancer 8th T1-2N0-1M0 were retrospectively recruited. All received intensity-modulated radiotherapy (IMRT)±chemotherapy (CT) from 2001 to 2010. Results With 15.7-year median follow-up, 10-year locoregional recurrence-free survival, distant metastasis-free survival (DMFS), disease-specific survival (DSS), and overall survival (OS) were 93.3%, 93.5%, 92.9% and 88.2%, respectively. Multivariable analyses showed cervical lymph nodes positive and pre-treatment prognostic nutritional index ≥ 52.0 could independently predict DMFS (p=0.036 and p=0.011), DSS (p=0.014 and p=0.026), and OS (p=0.002 and p < 0.001); Charlson comorbidity index < 3 points could predict DSS (p=0.011); age > 45 years (p=0.002) and pre-treatment lactate dehydrogenase ≥ 240 U/L (p < 0.001) predicted OS. No grade 4 late toxicity happened; grade 3 late toxicities included subcutaneous fibrosis (4.3%), deafness or otitis (4.8%), skin dystrophy (2.1%), and xerostomia (1.1%). No differences on survivals were shown between IMRT+CT vs. IMRT alone in stage II patients, even in T2N1M0 (p > 0.05). Unsurprising, patients in IMRT+CT had more acute gastrointestinal reaction, myelosuppression, mucositis, late ear toxicity, and cranial nerve injury (all p < 0.05) than IMRT alone group. Conclusion Superior tumor control and satisfying long-term outcomes could be achieved with IMRT in early-stage NPC with mild late toxicities. As CT would bring more toxicities, it should be carefully performed to stage II patients.

Association of Helicobacter pylori with Elevated Blood Ammonia Levels in Cirrhotic Patients: A Meta-Analysis

Hai-Xing Jiang,Shan-Yu Qin,Zhi-gang Min,Ming-Zhi Xie,Tao Lin,Bang-Li Hu,Xiao-Yun Guo 연세대학교의과대학 2013 Yonsei medical journal Vol.54 No.4

Purpose: The association between Helicobacter pylori (H. pylori) and blood ammonia levels in cirrhotic patients is controversial. We aimed to clarify this controvercy by performing a meta-analysis of published studies. Materials and Methods:We searched PubMed, EMBASE and Cochrane library for studies which explored the association between H. pylori and blood ammonia levels in cirrhotic patients before May 2012. Six cohort studies involved in 632 H. pylori positive and 396 H. pylori negative cirrhotic patients were eligible for our analysis. The summary estimates were presented as standard means differences (SMD) and 95% confidence intervals (CI) from individual studies. Results: Overall, there was significant association between H. pylori infection and the elevated blood ammonia levels in cirrhotic patients (SMD=0.34, 95% CI=0.21-0.47, I2=42.1%). Sensitivity analysis further confirmed this association. Subgroup analysis showed that the association was found only in Asian ethnicity, but not in Caucasian ethnicity. Conclusion:H. pylori infection is associated with elevated blood ammonia levels in cirrhotic patients, and more large scale studies and stratify analysis are warranted in order to further evaluate this association.

Reference gene selection for transcriptional profiling by RT-qPCR in the 28-spotted larger potato ladybird

Zhang Yu-Xing,Tan Qiao,Shen Chen-Hui,Wu Jian-Jian,Wu Yi-Kuan,Li Wen-Ze,Jin Lin,Li Guo-Qing 한국응용곤충학회 2022 Journal of Asia-Pacific Entomology Vol.25 No.2

Henosepilachna vigintioctomaculata is one of the most serious defoliates attacking potatoes. However, studies on functional genes have greatly been limited due to the insufficiency of effective and stable endogenous references to normalize RT-qPCR data. In this report, nine housekeeping genes (RPL4, RPL6, RPL13, RPL32, RPS18, ACT, EF1α, GAPDH and α-TUB) involved in different biological processes were selected. Their expression levels under diverse experimental conditions including developmental stages, tissues, temperatures and host plants were determined using RT-qPCR technology. The tested candidate genes were comprehensively ranked based on five alternative stability analysis methods (Ct value, geNorm, NormFinder, BestKeeper and ReFinder). The results revealed that the optimal internal reference genes varied under different experimental conditions. Any gene pair among the five candidates (RPL4, RPL13, RPL32, RPS18 and EF1α) was a suitable reference gene set under different temperatures and on different host plants. A combination of RPL6 and RPL13 was recommended as the best reference gene set across different developmental stages. A pair of RPS18 and EF1α was ranked as the optimal reference gene combination within different tissues. The most suitable reference genes were RPS18 and RPL13 under four different experimental conditions. Our findings not only establish an accurate and reliable normalization of RT-qPCR data, but also lay a solid foundation for further functional gene researches in H. vigintioctomaculata

가루 녹차와 그 주요 성분의 항비만 효과

Kazutoshi Sayama,Shi Xing Lin,Guo Dong Zheng,Itaro Oguni 한국식품과학회 2003 국제녹차심포지엄 Vol.2003 No.1

Crack identification based on Kriging surrogate model

Gao, Hai-Yang,Guo, Xing-Lin,Hu, Xiao-Fei Techno-Press 2012 Structural Engineering and Mechanics, An Int'l Jou Vol.41 No.1

Kriging surrogate model provides explicit functions to represent the relationships between the inputs and outputs of a linear or nonlinear system, which is a desirable advantage for response estimation and parameter identification in structural design and model updating problem. However, little research has been carried out in applying Kriging model to crack identification. In this work, a scheme for crack identification based on a Kriging surrogate model is proposed. A modified rectangular grid (MRG) is introduced to move some sample points lying on the boundary into the internal design region, which will provide more useful information for the construction of Kriging model. The initial Kriging model is then constructed by samples of varying crack parameters (locations and sizes) and their corresponding modal frequencies. For identifying crack parameters, a robust stochastic particle swarm optimization (SPSO) algorithm is used to find the global optimal solution beyond the constructed Kriging model. To improve the accuracy of surrogate model, the finite element (FE) analysis soft ANSYS is employed to deal with the re-meshing problem during surrogate model updating. Specially, a simple method for crack number identification is proposed by finding the maximum probability factor. Finally, numerical simulations and experimental research are performed to assess the effectiveness and noise immunity of this proposed scheme.

Crack identification based on Kriging surrogate model

Hai-yang Gao,Xing-lin Guo,Xiao-fei Hu 국제구조공학회 2012 Structural Engineering and Mechanics, An Int'l Jou Vol.41 No.1

Kriging surrogate model provides explicit functions to represent the relationships between the inputs and outputs of a linear or nonlinear system, which is a desirable advantage for response estimation and parameter identification in structural design and model updating problem. However, little research has been carried out in applying Kriging model to crack identification. In this work, a scheme for crack identification based on a Kriging surrogate model is proposed. A modified rectangular grid (MRG) is introduced to move some sample points lying on the boundary into the internal design region, which will provide more useful information for the construction of Kriging model. The initial Kriging model is then constructed by samples of varying crack parameters (locations and sizes) and their corresponding modal frequencies. For identifying crack parameters, a robust stochastic particle swarm optimization (SPSO) algorithm is used to find the global optimal solution beyond the constructed Kriging model. To improve the accuracy of surrogate model, the finite element (FE) analysis soft ANSYS is employed to deal with the re-meshing problem during surrogate model updating. Specially, a simple method for crack number identification is proposed by finding the maximum probability factor. Finally, numerical simulations and experimental research are performed to assess the effectiveness and noise immunity of this proposed scheme.