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Multiresolution and multimaterial topology optimization of fail-safe structures under B-spline spaces

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Frontiers of Mechanical Engineering 2023年第4期18卷 149-163页

作者： Yingjun WANG Zhenbiao GUO Jianghong YANG xinqing LI National Engineering Research Center of Novel Equipment for Polymer Processing South China University of TechnologyGuangzhou 510641China The Key Laboratory of Polymer Processing Engineering of the Ministry of Education South China University of TechnologyGuangzhou 510641China Guangdong Provincial Key Laboratory of Technique and Equipment for Macromolecular Advanced Manufacturing South China University of TechnologyGuangzhou 510641China State Key Laboratory of Digital Manufacturing Equipment and Technology Huazhong University of Science and TechnologyWuhan 430074China

This study proposes a B-spline-based multiresolution and multimaterial topology optimization(TO)design method for fail-safe structures(FSSs),aiming to achieve efficient and lightweight structural design while ensuring safety and facilitating the postprocessing of topological *** approach involves constructing a multimaterial interpolation model based on an ordered solid isotropic material with penalization(ordered-SIMP)that incorporates failsafe *** reduce the computational burden of finite element analysis,we adopt a much coarser analysis mesh and finer density mesh to discretize the design domain,in which the density field is described by the B-spline *** B-spline can efficiently and accurately convert optimized FSSs into computer-aided design *** 2D and 3D numerical examples demonstrate the significantly enhanced computational efficiency of the proposed method compared with the traditional SIMP approach,and the multimaterial TO provides a superior structural design scheme for ***,the postprocessing procedures are significantly streamlined.

关键词： multiresolution multimaterial topology optimization fail-safe structure B-spline

Accurate scattering centers modeling for complex conducting targets based on induced currents

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Science China(Information Sciences) 2021年第2期64卷 268-270页

作者： Guangliang XIAO Kunyi GUO Biyi WU xinqing SHENG Institute of Applied Electromagnetic School of Information and ElectronicsBeijing Institute of Technology

Dear editor,According to the electromagnetic theory, each scattering center(SC) is equivalent to a mathematical discontinuity in Stratton-Chu integrals [1]. From the view of geometrical structure, the positions of SCs correspond to the discontinuities of surface and specular points. Therefore, the signatures of SCs in radar images can represent the actual geometric characteristics. Three-dimension SC model has been successfully applied for the radar target reconstruction and automatic target recognition(ATR) [2].

关键词： scattering center model induced currents complex target time-frequency representation (TFR) parameter estimation

The use of evidential belief functions for mineral potential mapping in the Nanling belt, South China

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Frontiers of Earth Science 2015年第2期9卷 342-354页

作者： Yue LIU Qiuming CHENG Qinglin XIA xinqing WANG State Key Laboratory of Geological Processes and Mineral Resources China University of Geosciences Wuhan 430074 China Faculty of Earth Resources China University of Geosciences Wuhan 430074 China Department of Earth and Space Science and Engineering Department of Geography York University Toronto M3JIP3 Canada

In this study, the evidential belief functions （EBFs） were applied for mapping tungsten polymetallic potential in the Nanling belt, South China. Seven evidential layers （e.g., geological, geochemical, and geophysical） related to tungsten polymetallic deposits were extracted from a multi-source geospatial database. The relationships between evidential layers and the target deposits were quantified using EBFs model. Four EBF maps （belief map, disbelief map, uncertainty map, and plausibility map） are generated by integrating seven evidential layers which provide meaningful interpretations for tungsten polymetallic potential. On the final predictive map, the study area was divided into three target zones of high potential, moderate potential, and low potential areas, among which high potential and moderate potential areas accounted for 17.8% of the total area, containing 81% of the total deposits. To evaluate the success rate accuracy, the receiver operating characteristic （ROC） curves and the area under the curves （AUC） for the belief map were calculated. The area under the curve is 0.81 which indicates that the capability for correctly classifying the areas with existing mineral deposits is satisfactory. The results of this study indicate that the EBFs were effectively used for mapping mineral potential and for managing uncertainties asso- ciated with evidential layers.

关键词： Dempster-Shafer theory of evidence GIS,uncertainty tungsten polymetallic deposit ROC curve

Estimation of vector miss distance for complex objects based on scattering center model

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Science China(Information Sciences) 2021年第4期64卷 235-237页

作者： Jie WU Kunyi GUO Biyi WU xinqing SHENG Institute of Applied Electromagnetic School of Information and ElectronicsBeijing Institute of Technology

Dear editor,This study presents a method to estimate vector miss distance (VMD) for complex objects based on scattering center (SC) models. In the method, the dependence of the SCs on the aspect angle of the light of sight (LOS) is applied in VMD estimation. This method requires only the radar echoes in a short time frame when the flying object approaches to the closet point of approach (CPA).

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Investigation of low-molecular weight organic acids and their spatiotemporal variation characteristics in Hongfeng Lake,China

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Journal of Environmental Sciences 2013年第2期25卷 237-245页

作者： Min Xiao Fengchang Wu Liying Wang xinqing Li Rongsheng Huang State Key Laboratory of Environmental Geochemistry Institute of GeochemistryChinese Academy of Sciences Chinese Research Academy of Environmental Sciences

The identities and concentrations of low-molecular-weight organic acids （LMWOAs） were determined by ion chromatography throughout a 20-m water column in Hongfeng Lake, China. The spatiotemporal variations of LMWOAs and their contributions to dissolved organic matter （DOM） in a research period of 24 hr were also investigated. The results demonstrated that five LMWOAs （lactic, acetic, pyruvic, sorbic, oxalic acid） were detected, and their total concentration and proportion in DOC were 6.55 μmol/L and 7.47%. Their average levels were 2.50, 0.65, 2.35, 0.96 and 0.09 μmol/L, respectively. LMWOAs were higher during daytime （10：00-18：00 on Jun 13, 2008） than nighttime （21：00-6：00 the next morning）, in particular 4.99 μmol/L high in the epilimnion （ 1 m water depth）, reflecting the fact that direct import from terrigenous sources and photochemical production from humic materials were dominant during LMWOAs＇ origin and accumulation. The same factors caused LMWOAs to be 0.63 μmol/L in the epilimnion higher than in the hypolimnion. The rapid decrease of total organic acid （TOA） up until 18：00 mainly resulted from bio-uptake and mineralization in the hypolimnion （〉1 m water depth）. Pyruvic acid increased with time in the epilimnion and decreased in the hypolimnion, largely related to the two contrary processes of continuous degradation and synthesis of macromolecular organic matter during life materials＇ cycle mediated by organisms. Simultaneously, plankton behavior and thermal stratification played a pivotal role in LMWOAs＇ behavior in the water column, causing decreasing and increasing profiles. The distribution of LMWOAs represents an interesting resource for biogeochemical research of DOM in aquatic ecosystems.

关键词： Hongfeng Lake low-molecular-weight organic acids photochemical production spatiotemporal variations thermal stratification

Efficacy of endoscopic treatment on patients with severe dysplasia/carcinoma in situ of esophageal squamous cell carcinoma: A prospective cohort study

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Chinese Journal of Cancer Research 2019年第2期31卷 357-365页

作者： Meng Wang Changqing Hao Shuanghua Xie Shanrui Ma Qing Ma Rongshou zheng Ru Chen xinqing Li Wenqiang Wei Office of Cancer Registry National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital Chinese Academy of Medical Sciences and Peking Union Medical College Department of Endoscopy Linzhou Cancer Hospital

Objective: To explore the natural history of severe dysplasia/carcinoma in situ(SD/CIS) patients and to evaluate the efficacy of endoscopic treatment to SD/CIS ***: Between January 2005 and December 2009, a population-based prospective screening program on esophageal squamous cell carcinoma(ESCC) was performed in Linzhou, China, with endoscopic screening plus iodine staining. All the eligible histologically confirmed SD/CIS patients were followed up through the door-todoor follow-up and local cancer registry. The endpoint was diagnosed as ESCC or the December 31 st, ***-Meier survival analysis and Log-rank test were used to compare the survival rates among treated and untreated ***: A total of 175 SD/CIS patients were enrolled and grouped by whether they received endoscopic treatment. Eleven-year cumulative incidence rates for untreated and treated SD/CIS patients were 10.7% [95%confidence interval(95% CI): 6.9-16.1] and 3.2%(95% CI: 1.4-7.0), respectively. The ESCC incidence free survival rate, and all-cause incidence and mortality free survival rates were all significantly higher in the treated patients vs. untreated patients(P=0.043, P=0.008 and P=0.015, respectively). The ESCC mortality free survival rate showed no significant differences between the two groups(P=0.847).Conclusions: The cumulative incidence rate of SD/CIS patients to ESCC was much lower than previously reported. The Kaplan-Meier survival analysis showed that endoscopic treatment could increase the ESCC and allcause disease-free survival rates of SD/CIS patients significantly.

关键词： Endoscopy esophageal squamous cell carcinoma precancerous lesions management mass screening

Floating Clamping Mechanism of PT Fuel Injector and Its Dynamic Characteristics Analysis

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Chinese Journal of Mechanical Engineering 2012年第3期25卷 550-556页

作者： WANG xinqing LIANG Sheng XIA Tian WANG Dong QIAN Shuhua Engineering Institute of Engineering Corps University of Science&Technology of Chinese People's Liberation ArmyNanjing 210007China Bureau of Navy Engineering Design&Research Beijing 100841China

PT fuel injector is one of the most important parts of modern diesel *** satisfy the requirements of the rapid and accurate test of PT fuel injector,the self-adaptive floating clamping mechanism was developed and used in the relevant *** dynamic characteristics directly influence the test efficiency and ***,due to its special structure and complex oil pressure signal,related documents for evaluating dynamic characteristics of this mechanism are lack and some dynamic characteristics of this mechanism can＇t be extracted and recognized effectively by traditional *** at the problem above-mentioned,a new method based on Hilbert-Huang transform（HHT） is ***,combining with the actual working process,the dynamic liquid pressure signal of the mechanism is *** analyzing the pressure fluctuation during the whole working process in time domain,oil leakage and hydraulic shock in the clamping chamber are ***,owing to the nonlinearity and nonstationarity of pressure signal,empirical mode decomposition is used,and the signal is decomposed and reconstructed into forced vibration,free vibration and *** analyzing forced vibration in the time domain,machining error and installation error of cam are ***,free vibration component is analyzed in time-frequency domain with HHT,the traits of free vibration in the time-frequency domain are *** with traditional methods,Hilbert spectrum has higher time-frequency resolutions and higher *** improved mechanism based on the above analyses can guarantee the test accuracy of injector *** new method based on the analyses of the pressure signal and combined with HHT can provide scientific basis for evaluation,design improvement of the mechanism,and give references for dynamic characteristics analysis of the hydraulic system in the interrelated fields.

关键词： PT fuel injector floating clamping mechanism dynamic characteristics analysis Hilbert-Huang transform

Open-Source Codes of Topology Optimization: A Summary for Beginners to Start Their Research

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Computer Modeling in Engineering & Sciences 2023年第10期137卷 1-34页

作者： Yingjun Wang xinqing Li Kai Long Peng Wei National Engineering Research Center of Novel Equipment for Polymer Processing The Key Laboratory of Polymer Processing Engineering of the Ministry of EducationGuangdong Provincial Key Laboratory of Technique and Equipment for Macromolecular Advanced ManufacturingSouth China University of TechnologyGuangzhou510641China State Key Laboratory of Alternate Electrical Power Systemwith Renewable Energy Sources North China Electric Power UniversityBeijing102206China State Key Laboratory of Subtropical Building Science School of Civil Engineering and TransportationSouth China University of TechnologyGuangzhou510641China

Topology optimization(TO),a numerical technique to find the optimalmaterial layoutwith a given design domain,has attracted interest from researchers in the field of structural optimization in recent *** beginners,opensource codes are undoubtedly the best alternative to learning TO,which can elaborate the implementation of a method in detail and easily engage more people to employ and extend the *** this paper,we present a summary of various open-source codes and related literature on TO methods,including solid isotropic material with penalization(SIMP),evolutionary method,level set method(LSM),moving morphable components/voids(MMC/MMV)methods,multiscale topology optimization method,***,we classify the codes into five levels,fromeasy to difficult,depending on their difficulty,so that beginners can get started and understand the form of code implementation more quickly.

关键词： Topology optimization open-source code optimization methods code classification beginners

Efficient Computation of Scattering from Targets with Negative Impedance Surface

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Journal of Beijing Institute of Technology 2017年第1期26卷 90-94页

作者： Jingwei Hao Hongwei Gao xinqing Sheng School of Information and Electronics Beijing Institute of Technology Beijing 100081 China

Current surface integral equations used for computing scattering from targets with negative impedance boundary condition（IBC）are not efficient.A modified surface dual integral equation（M-SDIE）for targets with negative IBC is presented.A pure imaginary number is used to balance the *** is proved that the M-SDIE is accurate and efficient with three numerical *** first numerical example shows that the M-SDIE is accurate compared with *** second example shows that the presented SIE is *** the third example,a missile head is selected to present the computing power of the *** the examples show that the M-SDIE is an efficient algorithm for negative IBC.

关键词： electromagnetic scattering impedance boundary condition (IBC) method of moments(MoM) surface integral equation