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Machine learning based models for predicting compressive strength of geopolymer concrete

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Frontiers of Structural and Civil Engineering 2024年第7期18卷 1028-1049页

作者： Quang-Huy LE Duy-hung nguyen Thanh SANG-TO Samir KHATIR Hoang LE-MINH Amir H.GANDOMI Thanh CUONG-LE Center for Engineering Application and Technology Solutions Ho Chi Minh City Open UniversityHo Chi Minh 700000Vietnam Institute of Civil Engineering Ho Chi Minh City University of TransportHo Chi Minh 700000Vietnam Faculty of Engineering&Information Technology University of Technology SydneyUltimoNSW 2007Australia

Recently,great attention has been paid to geopolymer concrete due to its advantageous mechanical and environmentally friendly *** effort has been made in experimental studies to advance the understanding of geopolymer concrete,in which compressive strength is one of the most important *** facilitate engineering work on the material,an efficient predicting model is *** this study,three machine learning(ML)-based models,namely deep neural network(DNN),K-nearest neighbors(KNN),and support vector machines(SVM),are developed for forecasting the compressive strength of the geopolymer concrete.A total of 375 experimental samples are collected from the literature to build a database for the development of the predicting models.A careful procedure for data preprocessing is implemented,by which outliers are examined and removed from the database and input variables are standardized before feeding to the fitting *** standard K-fold cross-validation approach is applied for evaluating the performance of the models so that overfitting status is well managed,thus the generalizability of the models is *** effectiveness of the models is assessed via statistical metrics including root mean squared error(RMSE),mean absolute error(MAE),correlation coefficient(R),and the recently proposed performance index(PI).The basic mean square error(MSE)is used as the loss function to be minimized during the model fitting *** three ML-based models are successfully developed for estimating the compressive strength,for which good correlations between the predicted and the true values are obtained for DNN,KNN,and *** numerical results suggest that the DNN model generally outperforms the other two models.

关键词： geopolymer concrete compressive strength prediction machine-learning based model deep neural network K-nearest neighbor support vector machines

Revision of Outcomes and Complications Following Open Reduction, and Zigzag Osteotomy Combined with Fibular Allograft for Developmental Dysplasia of the Hip in Children

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Open Journal of Orthopedics 2016年第7期6卷 184-200页

作者： nguyen Ngoc hung Vietnam National Hospital for Pediatrics Hanoi Vietnam

Background: Reports of the efficacy of open reduction and Zigzag Osteotomy combined Fibular Allograft (ZOFA) for developmental dysplasia of the hip. The purposes of this study were to evaluate the long-term outcomes and complications after surgery. Methods: We performed a retrospective match-controlled study in which 158 patients had 181 hips with developmental dysplasia of the hip. Radiographs were found of acetabular index, height of dislocation, Tönnis grade, abduction angle in the spica cast, and Severin grade. At final follow-up, deformity of femoral head or neck or acetabulum was evaluated according to the Severin. Avascular necrosis was rated according to Kalamchi. Clinical evaluation was made according to modified McKay criteria. Results: Between 2009 and 2012, 133 girls (84.2%) and 25 boys (15.8%) with developmental dysplasia of the hip underwent open reduction and ZOFA;135 (85.4%) were unilateral, and 23 (14.6%) were bilateral. Patients were divided into 2 groups: group 1 included 54 patients (62 hips) aged 12 months - ≤18 months and group 2 included 84 patients (119 hips), aged >18 months - ≤36 months. According to Tönnis system: type 3 appeared in 127 hips (70.2%), and Type 4 in 54 hip (29.8%). The anterior approach was used to expose inner table of the ilium and ZOFA in all cases. Acetabular index was improved;preoperation was 42.95°, and latest follow-up 17.26°. The Kirschner Wires (KW) were not used to fix the fibular allograft at the pelvic osteotomy site. All of the fibular allografts were completely incorporated in mean time of 14 weeks (range, 12 weeks - 17 weeks) post-surgery. Clinical evaluation according to modified McKay criteria: satisfactory result (excellent and good) was achieved in 141 hips (77.9%). Avascular Necrosis (AVN) happened in 61 hips (33.7%), redislocation in 18 hips (9.9%), coxa vara in 4 hips (2.2%), trendelenburg gait in 4 hips (2.2%), and supracondylar femoral fractures in 2 hips (1.1%). Conclusions: On the basis o

关键词： DDH Redislocation Revision Surgery Hip Dysplasia Bone Allograft Salter’s Osteotomy Avascular Necrosis

Effective Electrical Submersible Pump Management Using Machine Learning

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Open Journal of Civil Engineering 2021年第1期11卷 70-80页

作者： Son Tung Pham phi Son Vo Dac Nhat nguyen Faculty of Geology & Petroleum Engineering Hochiminh City University of Technology-Vietnam National University Hochiminh Vietnam

Artificial lift plays an important role in petroleum industry to sustain production flowrate and to extend the lifespan of oil wells. One of the most popular artificial lift methods is Electric Submersible Pumps (ESP) because it can produce high flowrate even for wells with great depth. Although ESPs are designed to work under extreme conditions such as corrosion, high temperatures and high pressure, their lifespan is much shorter than expected. ESP failures lead to production loss and increase the cost of replacement, because the cost of intervention work for ESP is much higher than for other artificial lift methods, especially for offshore wells. Therefore, the prediction of ESP failures is highly valuable in oil production and contributes a lot to the design, construction and operation of oil wells. The contribution of this study is to use 3 machine learning algorithms, which are Decision Tree, Random Forest and Gradient Boosting Machine, to build predictive models for ESP lifespan while using both dynamic and static ESP parameters. The results of these models were compared to find out the most suitable model for the prediction of ESP life cycle. In addition, this study also evaluated the influence factor of various operating param

Redislocation Following Zigzag Osteotomy Combined with Fibular Allograt for Dislocation of the Hip in Children

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Open Journal of Orthopedics 2016年第4期6卷 86-97页

作者： nguyen Ngoc hung National Hospital for Pediatrics Ha Noi Viet Nam

We have reviewed 17 patients (18 hips) who required repeated open reduction for recurrent or persistent dislocation after a previous attempt at zigzag osteotomy combined with fibular allowgraft for developmental dysplasia of the hip (DDH). The purposes of this study were to examine predictors of redislocation and to evaluate the long-term outcomes after revision surgery. The mean age at primary open reduction was 24 months (13 to 36). The median time to the recognition of failure was 4.6 months. The second reduction was performed at a mean age of 26.3 months (17 to 42) and the mean age at final follow-up was 79.7 months (58 to 105) and the mean time follow-up was 42.4 months (37 to 76). We treated the hips with a new open reduction through an anteromedial approach. A constricted anteromedial capsule was always found as the main factor;all had an intact anteromedial capsule, and there was an inverted transverse ligament in five cases and a very tight psoas tendon in another four cases, eversion of the limbus in six cases, densing anterior capsule in five cases. We perform with the condition that all hips were cleared of scar tissue;five hips had adductor tenotomy;four hips required release of the psoas tendon, five eversion of the limbus. Release of the transverse ligament was required in five cases each. All hips with Kirschner wire through the femoral head into the acetabulum. Three hips required femoral shortening (average of 1.5 cm);a derotation varus osteotomy was performed in two hips from ten and twelve weeks after repeated open reduction. Postoperative results according to modified McKay criteria for clinical: excellent: 3 of 18 hips (16.7%);good: 8 of 18 hips (44.4%);fair: 6 of 18 hips (33.3%);and poor: 1 of 18 hips (5.6%). We suggest that technical failure is usually the cause for redislocation with all that has an intact anteromedial capsule. There was an inverted transverse ligament, tight psoas tendon, eversion of the limbus, and densing anterior capsule

关键词： DDH Redislocation Anteromedial Approach Salter Innominate Osteotomy Femoral Shortening

An Analytical Approach for Nonlinear Buckling Analysis of Torsionally Loaded Sandwich Carbon Nanotube Reinforced Cylindrical Shells with Auxetic Core

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Advances in Applied Mathematics and Mechanics 2023年第2期15卷 468-484页

作者： Dang Thuy Dong nguyen Thi Phuong Vu Hoai Nam Le Ngoc Ly nguyen Van Tien Vu Minh Duc Tran Quang Minh Vu Tho hung nguyen Thi Huong Giang Faculty of Civil Engineering University of Transport TechnologyHanoi 100000Vietnam Graduate School of Advanced Science and Engineering Hiroshima University1-4-1 KagamiyamaHigashi-HiroshimaHiroshima 739-8527Japan Faculty of Fundamental Science for Engineering University of Transport TechnologyHanoi 100000Vietnam

The main aim of this paper is to present an analytical approach on the postbuckling for torsionally loaded sandwich carbon nanotube(CNT)reinforced cylindrical shells with the auxetic *** considered shells consist of three layers,external and internal CNT reinforced layers,and the auxetic lattice core made by isotropic *** homogenization model for honeycomb auxetic lattice core is utilized,and the equilibrium equations are formulated based on the nonlinear Donnell’s thin shell theory with von Karman geometrical *** three terms of deflection are considered,the Airy’s stress function and Galerkin’s method are utilized,the explicit expression of critical buckling of torsionally loaded shells and load-deflection expression of postbuckling states are *** effects of two carbon nanotube reinforced layers,the auxetic core layer,the volume fraction of carbon nanotube on the torsional buckling behavior are examined and remarked.

关键词： Nonlinear postbuckling carbon nanotube reinforced composite cylindrical shell torsion auxetic core

Analytical Results of Cam Ranh-Tuy Phong Fault Characteristics and Its Relation to Mud Eruption in Nam Trung Bo Area, Viet Nam

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Journal of Geological Resource and Engineering 2016年第7期4卷 335-344页

作者： Truong Thanh phi Van Thom Bui Dang Manh nguyen Hanoi University of Natural Resources and Environment Hanoi Vietnam Institute of Geology Viet Nam Academy of Science and Technology Hanoi Vietnam

By analyzing the satellite images, topology map, geology map, geomorphology map, and field survey data, this study has determined the Cam Ranh-Tuy Phong fault in the South Central area, Viet Nam has NE-SW orientation and inclines to SE with high slope angle of 70-80°. During the Pliocene-Quaternary period, the Cam Ranh-Tuy Phong fault is left-lateral movement with the extension mechanisms, which formed the graben have an NE-SW orientation, deposited by Quaternary sediment. The fracture systems and fault are the channels for the mineral water and hot water to move up from the deep zone in the area of Cam Thinh Dong, Ha Nhi, Vinh Hao, Nha Me, Tuy Thinh..., and also to be the channels for the mud material, clay and underground water to move from below zone to the surface to form high mud mounds. The analytical results of clay mud have identified clay mineral composition to be main montmorilonit, illite, kaolinite, calcite, chlorite. The occurrence of montmorilonit minerals in this study area is characterized by the alkali-rich environment. The chemical composition of calcite is determined forming in the environment of with pH 〉 9, characterized by the add climates. Besides, other analytical results of clay mud also identified some minerals, such as： ankerite （Fe, Mg）CO3, calcite and some accessory minerals such as： fluorite, lepidocrokit with the participation hydrothermal process.

关键词： Fault zones mud eruption tectonic activities mineral water hot water.

Studying on Tyrosinase Inhibition Activity of Some Vietnamese Folk Plants Aims to Use in Skin-Whitening Cosmetics

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American Journal of Plant Sciences 2017年第6期8卷 1319-1328页

作者： nguyen Thi My Hanh nguyen Kim phi Phung Quach Ngo Diem Phuong Department of Plant Biotech and Biotransformation Faculty of Biology-Biotechnology University of Science Vietnam National University-Ho Chi Minh City Ho Chi Minh City Vietnam Department of Organic Chemistry Faculty of Chemistry University of Science Vietnam National University-Ho Chi Minh City Ho Chi Minh City Vietnam

White mulberry Morus alba and jackfruit Artocarpus heterophyllus are two of seven chosen Vietnamese folk plants which showed the highest tyrosinase inhibition activity. Besides, both of them showed antioxidant and antibacterial activities. Especially, the Sulforhodamine B (SRB) assay test result of the root core extract of M. alba figured out its non-toxicity on foreskin fibroblasts.

关键词： Morus alba Tyrosinase Inhibition Activity Antibacterial Antioxidant

Predicted aerodynamic damping of slender single beam structures in across-wind vibrations

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Acta Mechanica Sinica 2020年第5期36卷 990-998,I0001页

作者： Cung Huy nguyen Dinh Tung nguyen Department of Civil Engineering Industrial University of Ho Chi Minh CityHo Chi Minh City 700000Vietnam Department of Civil Engineering University of NottinghamNottingham NG72RDUK

The paper presents a generalization of the conventional analytical approach where the quasisteady theory is utilised to evalu-ate the across-wind aerodynamic damping of slender single beam *** generalized theory considers the variation of structural and aerodynamic parameters along the structural height,together with the nature of the vertical wind profile and mode ***-form solutions for typical uniform and tapered tall buildings are given.A numerical application on a prototype tall building shows that the conventional method may be oversimplified,which results in incorrect predictions of the aerodynamic damping.

关键词： Aerodynamic damping Across-wind Slender structure-Galloping Tall building

Anticancer effects of saponin and saponin–phospholipid complex of Panax notoginseng grown in Vietnam

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Asian Pacific Journal of Tropical Biomedicine 2016年第9期6卷 795-800页

作者： Thu Dang Kim Hai nguyen Thanh Duong nguyen Thuy Loi Vu Duc Thu Vu Thi hung Vu Manh Patcharee Boonsiri Tung Bui Thanh Department of Pharmacology and Clinical Pharmacy School of Medicine and PharmacyVietnam National University Department of Pharmaceutics and Pharmaceutical Technology School of Medicine and PharmacyVietnam National University Department of Pharmacology Hanoi University of Pharmacy Department of Pharmacognosy and Traditional Pharmacy School of Medicine and PharmacyVietnam National University Faculty of Biology VNU University of Science Key Laboratory of Enzyme and Protein Technology VNU University of Science Department of Pharmacology School of PharmacyLac Hong University Department of Biochemistry Faculty of MedicineKhon Kaen University

Objective:To evaluate the antitumor activity both in vitro and in vivo of saponin–phospholipid complex of Panax ***:The in vitro cytotoxic effect of saponins extract and saponin–phospholipid complex against human lung cancer NCI-H460 and breast cancer cell lines BT474 was examined using MTS *** in vivo evaluation of antitumor potential,saponin and saponin–phospholipid complex were administered orally in rats induced mammary carcinogenesis by 7,12-dimethylbenz(a)anthracene,for 30 ***:Our data showed that saponin–phospholipid complex had stronger anticancer effect compared to saponin *** IC50 values of saponin–phospholipid complex and saponin extract for NCI-H460 cell lines were 28.47 mg/m L and 47.97 mg/mL,respectively and these values for BT474 cells were 53.18 mg/mL and 86.24 mg/mL,*** vivo experiments,administration of saponin,saponin–phospholipid complex and paclitaxel(positive control) effectively suppressed 7,12-dimethylbenz(a) anthracene-induced breast cancer evidenced by a decrease in tumor volume,the reduction of lipid peroxidation level and increase in the body weight,and elevated the enzymatic antioxidant activities of superoxide dismutase,catalase,glutathione peroxidase in rat breast ***:Our study suggests that saponin extract from Panax notoginseng and saponin–phospholipid complex have potential to prevent cancer,especially breast cancer.

关键词： Panax notoginseng Saponin Saponin–phospholipid complex Breast cancer Antitumor