A direct-integration-based structural reliability analysis method using non-probabilistic convex model

Xiao-Bo Nie,Haibin Li 대한기계학회 2018 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.32 No.11

In practical structural reliability analysis, there is not only random uncertainty but also fuzzy uncertainty. Aiming at the fuzzy reliability of structure, a novel fuzzy reliability method is proposed based on direct integration method and ellipsoidal convex model. Firstly, the decomposition of fuzzy mathematics principle is used to convert fuzzy reliability model into non-probabilistic reliability model, in which fuzzy variables are converted into interval variables. The upper and lower bounds of interval variables are determined by the possibility distribution function on the membership value. Secondly, multidimensional ellipsoid convex models are constructed to quantify the uncertainty because of the complexity of non-probabilistic reliability. Finally, sigmoid function with adjustable parameter is introduced to direct integration method for approximating the step function, and then direct integration method is used to solve the fuzzy reliability. Numerical examples are investigated to demonstrate the effectiveness of the present method, which provides a feasible way for the structural fuzzy reliability analysis.

Realistic Simulation of Incompressible Fluids with Arbitrarily Shaped Boundaries

Xiao Nie,Leiting Chen,Chuan Zhou,Hang Qiu 보안공학연구지원센터 2015 International Journal of Multimedia and Ubiquitous Vol.10 No.6

We present a particle-based method for realistically modeling the interaction of incompressible fluids with arbitrarily shaped solid boundaries. When dealing with static solids, previous meshless Lagrangian approaches either require uniform sampling of solid boundaries or suffer from unexpected side effects. Our method resolves these issues using a new boundary handling algorithm that represents the solid surface as a single layer of boundary particles with different influence factors. This technique can more efficiently handle arbitrarily shaped boundaries without the side effects of existing approaches, and produces more realistic simulation results. We further propose a new form of weighting kernel that corrects the fluid density estimations and avoids negative pressures at the free surface. We have demonstrated the robustness and effectiveness of our method with a range of scenarios.

Monazites reveal timing and genesis of Nb-REE mineralization in trachyte from the Pingli area, North Daba Mountain, China

Xiao Nie,Zong-qi Wang,Lei Chen,Jingwu Yin,Gang Wang 한국지질과학협의회 2021 Geosciences Journal Vol.25 No.5

In recent years, several Nb-rare-earth-element (REE) deposits have been discovered in trachyte from the Pingli–Zhenping area of the North Daba Mountain. Of these, the Zhujiayuan Nb (-REE) deposit is particularly rich in monazite. In this study, electron probe microanalysis (EPMA) and laser-ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) were used to better understand the genesis of the deposit and constrain the timing of Nb-REE mineralization. The results show that most monazite in the deposit is closely related to various alteration minerals (biotite, sericite, albite, quartz, pyrite, and calcite), and monazite often has a lower ThO2 content (0.09–1.32 wt%), indicating its hydrothermal origin. Monazite and the dominant Nb-bearing mineral (columbite) have a close paragenetic relationship, indicating that Nb and REE were mineralized in the same period. LA-ICP-MS U-Pb dating on hydrothermal monazite grains shows a weighted average 206Pb/238U age of 237.2 ± 7.9 Ma, which represents the timing of REE mineralization. The origin of monazite, in combination with the alteration mineralogy and ore-forming age, suggests that fluid exsolved from the Early Mesozoic alkaline felsic melt induced widespread hydrothermal alteration and the formation of the Zhujiayuan Nb-REE deposit.

Meta-analysis of Circulating Tumor Cells as a Prognostic Marker in Lung Cancer

Ma, Xue-Lei,Xiao, Zhi-Lan,Liu, Lei,Liu, Xiao-Xiao,Nie, Wen,Li, Ping,Chen, Nian-Yong,Wei, Yu-Quan Asian Pacific Journal of Cancer Prevention 2012 Asian Pacific journal of cancer prevention Vol.13 No.4

Introduction: Recent studies have shown that circulating tumor cells (CTCs) play potential roles as diagnostic and prognostic biomarkers with various cancer types. The aim of this study was to comprehensively and quantitatively summarize the evidence for the use of CTCs to predict the survival outcome of lung cancer patients. Materials and Methods: Relevant literature was identified using Medline and EMBASE. Patients' clinical characteristics, overall survival (OS) and progression-free survival (PFS) together with CTC positive rates at different time points (before, during and after treatment) were extracted. A meta-analysis was performed to clarify the prognostic role of CTCs and the correlation between the CTC appearance and clinical characteristics. Results: A total of 12 articles containing survival outcomes and clinical characteristics and 15 articles containing only clinical characteristics were included for the global meta-analysis. The hazard ratio (HR) for OS predicted by pro-treatment CTCs was 2.61 [1.82, 3.74], while the HR for PFS was 2.37 [1.41, 3.99]. The HR for OS predicted by post-treatment CTCs was 4.19 [2.92, 6.00], while the HR for PFS was 4.97 [3.05, 8.11]. Subgroup analyses were conducted according to histological classification and detection method. Odds ratio (OR) showed the appearance of pro-treatment CTCs correlated with the lymph node status, distant metastasis, and TNM staging, while post-treatment CTCs correlated with TNM staging only. Conclusion: Detection of CTCs in the peripheral blood indicates a poor prognosis in patients with lung cancer.

Three Non-Aspartate Amino Acid Mutations in the ComA Response Regulator Receiver Motif Severely Decrease Surfactin Production, Competence Development, and Spore Formation in Bacillus subtilis

( Xiao Yu Wang ),( Chun Ping Luo ),( You Zhou Liu ),( Ya Feng Nie ),( Yong Feng Liu ),( Rong Sheng Zhang ),( Zhi Yi Chen ) 한국미생물 · 생명공학회 2010 Journal of microbiology and biotechnology Vol.20 No.2

The Relationship Between Preoperative Cervical Sagittal Balance and Clinical Outcome of Patients With Hirayama Disease Treated With Anterior Cervical Discectomy and Fusion

Xiao Lu,Guang-Yu Xu,Cong Nie,Yu Xuan Zhang,Jian Song,Jianyuan Jiang 대한척추신경외과학회 2021 Neurospine Vol.18 No.3

Objective: Anterior cervical discectomy and fusion (ACDF) is a common surgical method used to treat patients with Hirayama disease. And sagittal balance indexes have been revealed to be predictors of clinical outcomes in patients with cervical diseases, but their relationships with ACDF-treated Hirayama disease outcomes remain unknown. The purpose of this study is to evaluate the relationship of preoperative cervical sagittal balance indexes and clinical outcomes in ACDF-treated Hirayama disease patients. Methods: Eighty patients with Hirayama disease treated by ACDF were reviewed retrospectively. Six cervical sagittal balance parameters were collected including Cobb angle, T1 slope, C1–7 sagittal vertical axis (SVA), C2–7 SVA, center of gravity of the head (CGH)-C7 SVA, range of motion. The recovery outcomes of the patients were divided into 2 groups by Odom score and the differences in recovery between the 2 groups were confirmed by electromyography. The correlation between imaging parameters and postoperative outcome was evaluated with logistic regression. The receiver operating characteristic (ROC) curve and area under the ROC curve (AUC) were used to evaluate the significant result of logistic regression and the optimal diagnostic value. Results: Only 2 parameters, Cobb angle and CGH-C7 SVA, showed statistical correlation with the postoperative outcome assessment by logistic regression. AUC of Cobb angle and CGH-C7 SVA were 0.559 and 0.702 respectively. The optimal predictive threshold was 1.50° and 5.40 mm, respectively. Conclusion: A larger Cobb angle and smaller CGH-C7 SVA seemed to correlate with a better postoperative outcome. These 2 factors could be used to predict the outcome of surgical treatment of Hirayama disease preoperatively.

pH-sensitive drug controlled release core/shell fibers fabricated by combination of electrospinning and photopolymerization

Xiao-lei Zhu,Hongwei Zhang,Jun Nie,Guiping Ma 한국공업화학회 2017 Journal of Industrial and Engineering Chemistry Vol.45 No.-

pH-sensitive drug loaded core shellfibers were fabricated by a combination of electrospinning and UVphoto-polymerization. Combretastatin A4 (CA4) was selected as the model drug loaded in PLA to test thepH-sensitivity property of the core shellfibers. The morphology of thefibers was studied by scanningelectron microscopy (SEM), and the core shell structure of thefibers was confirmed by transmissionelectron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS). The drug release assay wastested via the UV–vis spectrophotometer, and the pH-sensitivity of core shellfibers was tested by drugrelease assay under pH 5.0 and 7.4.

Ru(II) Polypyridyl Complexes-Sensitized TiO2 Nanotubes for Photoreduction of CO2 Aqueous Solution

Yan Nie,Chen Wang,Jun Li,Xiao-Xun Ma 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2016 NANO Vol.11 No.12

Ruthenium (II) polypyridyl complexes modified titanium dioxide materials with anatase phase, the length of 10–100 nm, were synthesized by a hydrothermal method. Photocatalytic CO2 reduction experiments were performed in sensitized TiO2 aqueous suspensions under UV–Vis light in closed systems. And only methanol was detected in the liquid phase under the experiment condition. The effect of different photosensitizers content on the photoactivity of TiO2 was also studied, showing that Ru(BiDiPy)2(NCS)2 sensitized TiO2 was the optimal photocatalyst in transformation of CO2 to methanol. A possible mechanism for the photocatalytic reduction was also proposed in this paper.

Hyperspectral Image Unmixing for Classification and Recognition : An Overview

Mingyu Nie,Zhi Liu,Hui Xu,Xiaoyan Xiao,Fangqi Su,Jun Chang,Xiaomei Li 보안공학연구지원센터 2015 International Journal of Signal Processing, Image Vol.8 No.12

The limited resolution of image sensors and the complex diversity of nature, cause mixed pixel problems in hyperspectral technology. Such problems are common, and increase the complexity of hyperspectral image processing. Hyperspectral unmixing is crucial for hyperspectral image classification and recognition. In unmixing, the image signatures are represented as a linear combination of the basic materials. Unmixing is the process of decomposing a mixed pixel into constituent materials, and calculating the corresponding fractional abundance. If pure materials (end members) are present in an image, unmixing can be divided into two steps, namely, end member extraction and abundance decomposition. On the other hand, if there is no pure material, researchers have devised and investigated unsupervised and semi-supervised spectral unmixing technology. This article presents an overview of the state-of-the-art methods of hyperspectral unmixing and their extensions.

A New Strategy to Improve the Efficiency and Sustainability of Candida parapsilosis Catalyzing Deracemization of (R,S)-1-Phenyl-1,2-Ethanediol Under Non-Growing Conditions: Increase of NADPH Availability

( Yao Nie ),( Yan Xu ),( Qing Sen Hu ),( Rong Xiao ) 한국미생물 · 생명공학회 2009 Journal of microbiology and biotechnology Vol.19 No.1

Microbial oxidoreductive systems have been widely used in asymmetric syntheses of optically active alcohols. However, when reused in multi-batch reaction, the catalytic efficiency and sustainability of non-growing cells usually decreased because of continuous consumption of required cofactors during the reaction process. A novel method for NADPH regeneration in cells was proposed by using pentose metabolism in microorganisms. Addition of D-xylose, L-arabinose, or D-ribose to the reaction significantly improved the conversion efficiency of deracemization of racemic 1-phenyl-1,2-ethanediol to (S)-isomer by Candida parapsilosis cells already used once, which afforded the product with high optical purity over 97%e.e. in high yield over 85% under an increased substrate concentration of 15 g/l. Compared with reactions without xylose, xylose added to multi-batch reactions had no influence on the activity of the enzyme catalyzing the key step in deracemization, but performed a promoting effect on the recovery of the metabolic activity of the non-growing cells with its consumption in each batch. The detection of activities of xylose reductase and xylitol dehydrogenase from cell-free extract of C. parapsilosis made xylose metabolism feasible in cells, and the depression of the pentose phosphate pathway inhibitor to this reaction further indicated that xylose facilitated the NADPH-required deracemization through the pentose phosphate pathway in C. parapsilosis. moreover, by investigating the cofactor pool, the xylose addition in reaction batches giving more NADPH, compared with those without xylose, suggested that the higher catalytic efficiency and sustainability of C. parapsilosis non-growing cells had resulted from xylose metabolism recycling NADPH for the deracemization.