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Derivation of the Orthotropic Nonlinear Elastic Material Law Driven by Low-Cost Data(DDONE)

Acta Mechanica Solida Sinica 2022年第5期35卷 800-812页

作者： Qian Xiang Hang Yang K.I.Elkhodary Zhi Sun Shan Tang Xu Guo State Key Laboratory of Structural Analysis for Industrial Equipment Department of Engineering MechanicsDalian University of TechnologyDalian116023China International Research Center for Computational Mechanics Dalian University of TechnologyDalian116023China The Department of Mechanical Engineering The American University in CairoNew Cairo11835Egypt

Orthotropic nonlinear elastic materials are common in nature and widely used by various ***,there are only limited constitutive models available in today's commercial software(e.g.,ABAQUS,ANSYS,etc.)that adequately describe their mechanical ***,the material parameters in these constitutive models are also difficult to calibrate through low-cost,widely available experimental ***,it is paramount to develop new ways to model orthotropic nonlinear elastic *** this work,a data-driven orthotropic nonlinear elastic(DDONE)approach is proposed,which builds the constitutive response from stress–strain data sets obtained from three designed uniaxial tensile *** DDONE approach is then embedded into a finite element(FE)analysis framework to solve boundary-value problems(BVPs).Illustrative examples(e.g.,structures with an orthotropic nonlinear elastic material)are presented,which agree well with the simulation results based on the reference material *** DDONE approach generally makes accurate predictions,but it may lose accuracy when certain stress–strain states that appear in the engineering structure depart significantly from those covered in the data *** DDONE approach is thus further strengthened by a mapping function,which is verified by additional numerical examples that demonstrate the effectiveness of our modified ***,artificial neural networks(ANNs)are employed to further improve the computational efficiency and stability of the proposed DDONE approach.

关键词： Data-driven Orthotropic nonlinear elastic materials Constitutive law Finite element analysis Artificial neural network

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Data-driven modeling on anisotropic mechanical behavior of brain tissue with internal pressure

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Defence Technology（防务技术） 2024年第3期33卷 55-65页

作者： Zhiyuan Tang Yu Wang Khalil I.Elkhodary Zefeng Yu Shan Tang Dan Peng State Key Laboratory of Structural Analysis Optimization and CAE Software for Industrial EquipmentDalian University of Technology116023DalianPR China The Department of Mechanical Engineering The American University in CairoNew Cairo11835Egypt Department of Neurology The Second Hospital of Dalian Medical UniversityDalian116023PR China

Brain tissue is one of the softest parts of the human body,composed of white matter and grey *** mechanical behavior of the brain tissue plays an essential role in regulating brain morphology and brain ***,traumatic brain injury(TBI)and various brain diseases are also greatly influenced by the brain's mechanical *** white matter or grey matter,brain tissue contains multiscale structures composed of neurons,glial cells,fibers,blood vessels,etc.,each with different mechanical *** such,brain tissue exhibits complex mechanical behavior,usually with strong nonlinearity,heterogeneity,and directional *** a constitutive law for multiscale brain tissue using traditional function-based approaches can be very ***,this paper proposes a data-driven approach to establish the desired mechanical model of brain *** focus on blood vessels with internal pressure embedded in a white or grey matter matrix material to demonstrate our *** matrix is described by an isotropic or anisotropic nonlinear elastic model.A representative unit cell(RUC)with blood vessels is built,which is used to generate the stress-strain data under different internal blood pressure and various proportional displacement loading *** generated stress-strain data is then used to train a mechanical law using artificial neural networks to predict the macroscopic mechanical response of brain tissue under different internal ***,the trained material model is implemented into finite element software to predict the mechanical behavior of a whole brain under intracranial pressure and distributed body *** with a direct numerical simulation that employs a reference material model,our proposed approach greatly reduces the computational cost and improves modeling *** predictions made by our trained model demonstrate sufficient ***,we find that the level of internal blood pressur

关键词： Data driven Constitutive law Anisotropy Brain tissue Internal pressure

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Chronic niacin overload may be involved in the increased prevalence of obesity in US children

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World Journal of Gastroenterology 2010年第19期16卷 2378-2387页

作者： Li, Da Sun, Wu-Ping Zhou, Yi-Ming Liu, Qi-Gui Zhou, Shi-Sheng Luo, Ning Bian, Fu-Ning Zhao, Zhi-Gang Guo, Ming dalian Univ Coll Med Inst Basic Med Sci Dalian 116622 Liaoning Peoples R China Natl Inst Nat Sci Okazaki Inst Integrat Biosci Okazaki Aichi 8787 Japan dalian Med Univ Dept Hlth Stat Dalian 116044 Liaoning Peoples R China PLA 210 Hosp Dept Nucl Med Dalian 116021 Liaoning Peoples R China dalian Univ Coll Environm & Chem Engn Dalian 116622 Liaoning Peoples R China

AIM: To investigate nicotinamide’s action on glucose metabolism, and the association between niacin consumption and obesity prevalence. METHODS: Dynamic nicotinamide’s effect on plasma hydrogen peroxide and glucose metabolism was in- vestigated using oral glucose tolerance tests with or without nicotinamide in the same five healthy ***-regression analysis was used to examine the association between the niacin consumption and the obesity prevalence among US children using the data from the Economic Research Service of the US Department of Agriculture and from US Centers for Disease Control and Prevention, respectively. RESULTS: Compared with the control oral glucose tolerance test, the 1-h plasma hydrogen peroxide (1.4 ± 0.1 μmol/L vs 1.6 ± 0.1 μmol/L, P = 0.016) and insulin levels (247.1 ± 129.0 pmol/L vs 452.6 ± 181.8 pmol/L, P = 0.028) were signif icantly higher, and the 3-h blood glucose was signif icantly lower (5.8 ± 1.2 mmol/L vs 4.5 ± 1.1 mmol/L, P = 0.002) after coadministration of glucose and 300 mg nicotinamide. The obesity prevalence among american children increased with the increasing per capita niacin consumption, the increasing grain contribution to niacin due to niacin-fortification, and the increasing niacin-fortified ready-to-eat cereal consumption, with a 10-year lag. The regression analyses showed that the obesity prevalence in the US children of all age groups was determined by niacin consumption (R2 = 0.814, 0.961 and 0.94 for 2-5 years, 6-11 years and 12-19 years age groups, respectively). CONCLUSION: The appetite-stimulating effect of nicotinamide appears to involve oxidative stress. Excess niacin consumption may be a major factor in the increased obesity prevalence in US children.

关键词： Obesity Diabetes Niacin Nicotinamide

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Baseball Sans Borders

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Beijing Review 2006年第7期49卷 46-页

作者： ADAM FEENEY is an american living in dalian

If anyone needs a reminder that the word "fan" is merely the short form of "fanatic," they need only observe me watching baseball on the Internet. No, I'm not talking about a webcast with images of the game actually b... 详细信息

关键词： Baseball Sans Borders

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Role of combined propofol and sufentanil anesthesia in endoscopic injection sclerotherapy for esophageal varices

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World Journal of Gastroenterology 2017年第44期23卷 7875-7880页

作者： Yang Yu Sheng-Lin Qi Yong Zhang Department of Anesthesiology the Sixth People’s Hospital of Dalian Endoscopy Center the Sixth People’s Hospital of Dalian President Office the Sixth People’s Hospital of Dalian

AIM To investigate the efficacy and safety of a combination of sufentanil and propofol injection in patients undergoing endoscopic injection sclerotherapy(EIS) for esophageal varices(EVs). METHODS Patients with severe EVs who underwent EIS with sufentanil and propofol anesthesia between April 2016 and July 2016 at our hospital were reviewed. Although EIS and sequential therapy were performed under endotracheal intubation, we only evaluated the efficacy and safety of anesthesia for the first EIS procedure. Patients were intravenously treated with 0.5-1 μg/kg sufentanil. Anesthesia was induced with 1-2 mg/kg propofol and maintained using 2-5 mg/kg per hour of propofol. Information, regarding age, sex, weight, american Association of Anesthesiologists(ASA) physical status, Child-Turcotte-Pugh(CTP) classification, indications, preanesthetic problems, endoscopic procedure, successful completion of the procedure, anesthesia time, recovery time, and anesthetic agents, was recorded. Adverse events, including hypotension, hypertension, bradycardia, and hypoxia, were also *** Propofol and sufentanil anesthesia was provided in 182 procedures involving 140 men and 42 women aged 56.1± 11.7 years(range, 25-83 years). The patients weighed 71.4 ± 10.7 kg(range, 45-95 kg) and had ASA physical status classifications of Ⅱ(79 patients) or Ⅲ(103 patients). Ninety-five patients had a CTP classification of A and 87 had a CTP classification of B. Intravenous anesthesia was successful in all cases. The mean anesthesia time was 33.1 ± 5.8 min. The mean recovery time was 12.3 ± 3.7 min. Hypotension occurred in two patients(1.1%, 2/182). No patient showed hypertension during the endoscopic therapy procedure. Bradycardia occurred in one patient(0.5%, 1/182), and hypoxia occurred in one patient(0.5%, 1/182). All complications were easily treated with no adverse sequelae. All endoscopic procedures were completed *** The combined use of propofol and sufentanil injecti

关键词： Endoscopic injection Esophageal varices Propofol Sclerotherapy Sufentanil

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Localization and macroscopic instability in nanoporous metals

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Acta Mechanica Sinica 2022年第12期38卷 15-32页

作者： Zhangtao Sun Tianfu Guo Khalil I.Elkhodary Hang Yang Nian Zhou Shan Tan School of Earth Sciences and Resources China University of Geosciences(Beijing)Beijing 100083China Institute of High Performance Computing A*STARSingapore 138632Singapore Department of Mechanical Engineering The American University in CairoNew Cairo 11835Egypt Department of Engineering Mechanics Dalian University of TechnologyDalian I16081China School of Materials and Energy Engineering Guizhou Institute of TechnologyGuiyang 550003China

Ductile fracture generally relates to microscopic voiding and to strain localization in metallic *** the void size is reduced to the nanoscale,size effects often lead to a different macroscopic plastic behavior from that established for the same material with larger *** example,irradiation of metallic materials can generate a large number of voids at the nanoscale,leading to complex deformation *** present work advances the understanding of strain localization in nanoporous metallic materials,connecting both the microscopic(nano-)and macroscopic *** explore the physical mechanisms at the nanoscale,molecular dynamics(MD)simulations were here carried out,capturing multiple nanovoids ***,a homogenized continuum theory based in Gurson's constitutive framework is proposed,which enables us to explore how localized behavior at the macroscopic scale *** homogenized model incorporates the surface tension associated with nanosized *** importance of this surface tension is illustrated by several parametric studies on the conditions of localization,when a specimen is subjected to uniaxial *** parametric studies show that for smaller nanovoid sizes,and for a hardening matrix material,shear localization onset is *** proposed homogenization model was then used to predict localization behavior captured by our MD *** yield stress and the localization strain predicted by our continuum model are in general agreement with the trends obtained by MD ***,based on our present study,experimental results of shear failure strain *** of irradiation for several metals could be qualitatively explained rather *** model can therefore help shed light on prolonging the operation limits and the lifetime of irradiated metallic materials under complex loading conditions.

关键词： Nanovoids MD simulations Localization Surface tension Shear band

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Experimental and Theoretical Study on the Flexural Behavior of Recycled Concrete Beams Reinforced with GFRP Bars

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Journal of Renewable Materials 2021年第6期9卷 1169-1188页

作者： Xinzhan Chen Xiangqing Kong Ying Fu Wanting Sun Renguo Guan School of Civil Engineering Liaoning University of TechnologyJinzhou121001China Engineering Research Center of Continuous Extrusion Dalian Jiaotong UniversityDalian116028China

This paper experimentally investigated the flexural behavior of reinforced recycled aggregate concrete(RAC)beams reinforced with glass fiber-reinforced polymer(GFRP)bars.A total of twelve beams were built and tested up to failure under four-point *** main parameters were reinforcement ratio(0.38%,0.60%,and 1.17%),recycled aggregate replacement ratio(R=0,50%,and 100%)and longitudinal reinforcement types(GFRP and steel).The flexural capacity,failure modes,flexibility deformation,reinforcement strains and crack distribution of the tested beams were investigated and compared with the calculation models of american code ACI 440.1-R-15,Canadian code CSA S806-12 and *** tested results indicated that the reinforcement ratio has great influence on the ultimate load,crack width and deflection of GFRP-RAC beams,the recycled aggregate replacement ratio has little influence on ***,it was found that the reinforcement ratio has no obvious influence on the cracking load which was only related to the recycled aggregate replacement *** average cracking load decreased by 5%and 15%as the recycled aggregate replacement ratio increased from 0 to 50%and 100%.For the steel-RAC beams,the ultimate load was found to be about 1/2 of the ultimate load of GFRP-RAC beam under the same condition and the trend of strain,deflection and crack width were different from GFRP-RAC *** is due to the different material properties of GFRP bars and steel *** the other hand,the calculation results showed that ACI 440.1-R-15 and CSA S806-12 underestimated the ultimate load of GFRP-RAC ***,the deflection prediction of GFRP-RAC beams by CSA S806-12 is relatively accurate compared with ACI 440.1-R-15 and *** for the prediction of crack width,the results of ACI 440.1-R-15 prediction were in good agreement with the experimental results at the ultimate load,with the average value of 1.09±0.28.

关键词： GFRP bars recycled aggregate concrete replacing ratio flexural capacity reinforcement ratio

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Research and application of flood detention modeling for ponds and small reservoirs based on remote sensing data

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Science China(Technological Sciences) 2011年第8期54卷 2138-2144页

作者： CAO MingLiang ZHOU HuiCheng ZHANG Chi ZHANG AiJing LI HuiYun YANG Yang School of Hydraulic Engineering Dalian University of Technology Dalian 116024 China Sichuan Provincial Investigation Design & Research Institute of Water Conservancy & Hydropower Chengdu 610072 China

This paper proposes a method of small reservoir flood detention modeling that utilizes data from the american land resources satellite Landsat TM/ETM+. Precipitation and potential evapotranspiration are taken as the control conditions in this method on the basis of basin terrain classification. The objective of this method is to solve the question of a small-scale water conservancy project’s influence on flood forecasting precision, which can be used in the basin with multitudinous small reservoirs in the upstream region and can help estimate non-runoff data for small reservoir runoff. Taking the 20060826 flood as an example, the flood detention quantity of 19 small reservoirs is modeled. The results show that the absolute error of the total flood detention quantity is 0.2×10 4 m 3 , and the relative error is 0.12%. The flood detention quantity of small reservoirs in the entire basin is then modeled using this method, and the primary flood forecasting model is adjusted. After adjustment, the precision is significantly improved, with the relative error decreasing from 31.8% to 10.1%.

关键词： remote sensing data small reservoir flood detention modeling

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Privacy‐preserving remote sensing images recognition based on limited visual cryptography

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CAAI Transactions on Intelligence Technology 2023年第4期8卷 1166-1177页

作者： Denghui Zhang Muhammad Shafiq Liguo Wang Gautam Srivastava Shoulin Yin Cyberspace Institute of Advanced Technology Guangzhou UniversityGuangzhouChina Department of New Networks Peng Cheng LaboratoryShenzhenChina College of Information and Communications Engineering Dalian Minzu UniversityDalianChina Department of Mathematics and Computer Science Brandon UniversityBrandonManitobaCanada Research Centre for Interneural Computing China Medical UniversityTaichungTaiwanChina Department of Computer Science and Math Lebanese American UniversityBeirutLebanon College of Information and Communications Engineering Harbin Engineering UniversityHarbinChina

With the arrival of new data acquisition platforms derived from the Internet of Things(IoT),this paper goes beyond the understanding of traditional remote sensing *** fusion of remote sensing and computer vision has hit the industrial world and makes it possible to apply Artificial intelligence to solve problems such as automatic extraction of information and image ***,due to the complex architecture of IoT and the lack of a unified security protection mechanism,devices in remote sensing are vulnerable to privacy leaks when sharing *** is necessary to design a security scheme suitable for computation‐limited devices in IoT,since traditional encryption methods are based on computational *** Cryptography(VC)is a threshold scheme for images that can be decoded directly by the human visual system when superimposing encrypted *** stacking‐to‐see feature and simple Boolean decryption operation make VC an ideal solution for privacy‐preserving recognition for large‐scale remote sensing images in *** this study,the secure and efficient transmission of high‐resolution remote sensing images by meaningful VC is *** diffusing the error between the encryption block and the original block to adjacent blocks,the degradation of quality in recovery images is *** fine‐tuning the pre‐trained model from large‐scale datasets,we improve the recognition performance of small encryption datasets for remote sensing *** experimental results show that the proposed lightweight privacy‐preserving recognition framework maintains high recognition performance while enhancing security.

关键词： activity recognition feature extraction image classification KNN privacy protection remote monitoring remote sensing

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FPSO Global Strength and Hull Optimization

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Journal of Marine Science and Application 2014年第1期13卷 55-61页

作者： Junyuan Ma Jianhua Xiao Rui Ma Kai Cao COSCO(dalian) Shipyard Co. Ltd

Global strength is a significant item for floating production storage and offloading(FPSO) design, and steel weight plays an important role in the building costs of FPSO. It is the main task to consider and combine these two aspects by optimizing hull dimensions. There are many optional methods for the global strength analysis. A common method is to use the ABS FPSO Eagle software to analyze the global strength including the rule check and direct strength analysis. And the same method can be adopted for the FPSO hull optimization by changing the depth. After calculation and optimization, the results are compared and analyzed. The results can be used as a reference for the future design or quotation purpose.

关键词： global strength hull optimization FPSO steel weight building costs hull strength ship design hull design

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