Practical ANN Model for Estimating Buckling Load Capacity of Corroded Web-Tapered Steel I-Section Columns

Trong-Ha Nguyen,Van-Tien Phan,Duy-Duan Nguyen 한국강구조학회 2023 International Journal of Steel Structures Vol.23 No.6

This study develops an artificial neural network (ANN) to estimate the critical buckling load (CBL) of corroded web-tapered steel I-section (WTSI) columns in pre-engineered steel buildings. A total of 387 datasets are employed to develop the ANN model. The datasets are generated from the proposed analytical model and Newton–Raphson method. The input parameters of the developed ANN model contain the cross-sectional dimensions of the steel column (i.e., the top and bottom flange width, top and bottom flange thickness, maximum section height, minimum section height, and web thickness), elastic modulus of material, and the column height. Meanwhile, the CBL is the output parameter of the ANN model. A predictive process for the CBL of the corroded WTSI columns has been proposed based on the ANN model and previous corrosion model. Results reveal that the ANN model showed an excellent performance in predicting the CBL of the corroded steel columns. The R2 values of the training, testing, and validation data are 0.99975, 0.99916, and 0.99951, respectively. The root-mean-squared errors of the training, testing, and validation data are 96.705 (kN), 103.402 (kN), and 103.200 (kN), respectively. Additionally, the a20-index is very close to 1.0. Moreover, a graphical user interface tool is constructed to facilitate the CBL calculation of the corroded WTSI columns.

Leadership and Communication Skills towards Emotional Intelligence: A Case Study of FPT University in Vietnam

Trong Luan NGUYEN,Ha Ai My NGUYEN,Pham Thao Nguyen LUU,Minh Anh LE,Thi Anh Thu NGUYEN,Ngoc Tram NGUYEN 한국유통과학회 2022 The Journal of Asian Finance, Economics and Busine Vol.9 No.5

As society evolves, people are making more of an effort to learn more about human aspects, one of which is emotional intelligence, a topic on which education experts have traditionally concentrated. This is due to the fact that emotional intelligence has a significant impact on how people think and manage their emotions. On the other side, it promotes the development of expressive ability and aids people in better adapting to life. This study explores the relationship between communication skills, leadership skills, stress management, adaptability, and emotional intelligence of FPT University students to determine the factors that affect students’ emotional intelligence. To survey 500 FPT University students, this study used a sample size of 500. Previous studies used a 5-point Likert scale to assess the four skill elements. According to the results, students who completed the survey showed adequate communication skills, leadership qualities, stress management, adaptability, and emotional intelligence. Emotional intelligence is influenced by communication skills, leadership abilities, stress management, and flexibility. This suggests that students who master these four skills have higher levels of emotional intelligence. The outcomes of this study reveal that students have been conscious of Emotional Intelligence since a young age. The affirmations in this research paper will benefit students and young people interested in enhancing complimentary soft skills that boost Emotional Intelligence.

Prediction of Axial Compression Capacity of Cold-Formed Steel Oval Hollow Section Columns Using ANN and ANFIS Models

Trong-Ha Nguyen,Ngoc-Long Tran,Duy-Duan Nguyen 한국강구조학회 2022 International Journal of Steel Structures Vol.22 No.1

The steel oval hollow section (OHS) provides an aesthetic architecture and a greater local buckling strength. However, the existing design codes do not specify the eff ective width in calculating the load-bearing capacity of OHS members. This study aims to predict the axial compression capacity (ACC) of cold-formed steel OHS columns using artifi cial neural network (ANN) and adaptive neural fuzzy inference system (ANFIS) models. A total of 128 data sets collected from the literature were utilized to develop the ANN and ANFIS models. The performance of the two machine learning models was compared with three existing design codes. The results demonstrated that the developed ANN and ANFIS models predicted the ACC of steel OHS columns more accurately compared to the existing formulas. Specifi cally, the ANN model revealed a superior performance with the highest coeffi cient of determination and the smallest root means square errors. Moreover, the formulas based on ANN and ANFIS models, which accommodates all input parameters, were proposed to predict the ACC of coldformed steel OHS columns. The thickness of the cross-section was the most infl uential parameter on the ACC of the OHS column. By contrast, the column length negatively aff ected the ACC value of the steel column. Finally, a graphical user interface tool was developed to readily calculate the ACC of the steel OHS columns.

Prediction of Critical Buckling Load of Web Tapered I-Section Steel Columns Using Artificial Neural Networks

Trong-Ha Nguyen,Ngoc-Long Tran,Duy-Duan Nguyen 한국강구조학회 2021 International Journal of Steel Structures Vol.21 No.4

The web tapered I-section steel (WTIS) columns have been widely used in civil and industrial steel structures. However, the existing theoretical and empirical equations demonstrate a signifi cant discrepancy in estimating the critical axial load of the WTIS columns. This study aims to develop eff ective artifi cial neural networks (ANNs) for predicting the critical buckling load of the WTIS columns. A database of 269 fi nite element models of WTIS columns was generated, after verifying with experimental results, to develop the ANN model. The results of the proposed ANN model were also compared with those of existing formulas, highlighting that the ANN model in this study predicts the critical buckling load of the WTIS columns more accurately than the existing formulas. Moreover, the infl uences of input parameters on the critical buckling load of the WTIS columns were thoroughly investigated. An ANN-based formula, which considers input variables, was thereafter proposed to estimate the critical buckling load of the WTIS columns. Additionally, a graphical user interface tool has been developed for simplifying the design practice of the WTIS columns.

Determinants of Share Prices of Listed Companies Operating in the Steel Industry: An Empirical Case from Vietnam

NGUYEN, Phu Ha,NGUYEN, Phi-Hung,TSAI, Jung-Fa,NGUYEN, Thanh Tam,HO, Van Nguyen,DAO, Trong-Khoi Korea Distribution Science Association 2020 The Journal of Asian Finance, Economics and Busine Vol.7 No.12

In accordance with huge demand for capital to meet the expansion of steel production, there are more and more steel companies who have officially listed their stocks in HOSE and HNX. One of the key issues in successful initial public offerings and seasonal offerings for these companies is how to make stocks of steel companies become more attractive in the eyes of investors. The purpose of this research is to analyze the determinants of share prices of listed steel companies in Vietnam. This study utilized macro-economic variables, ratios and indicators representing characteristics of steel industry collected from Quarter 1/2006 to Quarter 4/2019 in association with the panel data and the feasible generalized least square (FGLS) model to evaluate the degree of these factors on the share prices. The results of the research show that ROE, Cons_rate, and CO2_rate are three main factors affecting the share prices of listed steel companies. Among which, ROE and Cons_rate have a positive effect, while CO2_rate has a negative effect on the share prices of listed steel companies. It also confirms the relationship between the environmental factor, construction industry factor and the stock prices. This lays foundations for recommendations for the future policies towards environmental protection and sustainable development.

Uptake of arsenic and heavy metals by native plants growing near Nui Phao multi-metal mine, northern Vietnam

Ha, Nguyen Thi Hoang,Ha, Nguyen Thi,Nga, Tran Thi Huyen,Minh, Nguyen Ngoc,Anh, Bui Thi Kim,Hang, Nguyen Thi An,Duc, Nguyen Anh,Nhuan, Mai Trong,Kim, Kyoung-Woong Elsevier 2019 Applied geochemistry Vol.108 No.-

<P><B>Abstract</B></P> <P>Phytoremediation is a plant-based, environment-friendly, and cost-effective technology that can be potentially used to remediate contaminated media. This study was conducted to evaluate the phytoextraction and phytostabilization potential, two common techniques of phytoremediation, of 21 plant species growing naturally at the largest tungsten (W) mine in Vietnam—the second largest production of W in the world. The average concentrations in different soil fractions were in the following order: residue > organically complexed, Fe- and Mn oxide-bound > carbonate bound > exchangeable. The total concentrations of arsenic (As), cadmium (Cd), copper (Cu), and zinc (Zn) in the soil varied by 34–3390, 4.87–81.6, 14.3–2080, and 21.9–370 mg/kg, respectively. The concentrations of As, Cd, Cu, and Zn in the shoots ranged 0.71–2400, 0.05–5.55, 4.81–249, and 13.3–380 mg/kg-DW, respectively. The concentrations of As and Cd in all soil samples and Cu in 70% of soil samples collected around the mine fluctuated within 2–227, 3–54, and up to 21-folds higher than the maximum allowable limit for agricultural soils in Vietnam (QCVN 03-MT:2015/BTNMT). The results indicated that hyperaccumulation levels (mg/kg-DW) were obtained for only As in <I>Pityrogramma calomelanos</I> (2400) and <I>Pteris vittata</I> L. (1860). Based on the recorded hyperaccumulation levels, translocation and accumulation factors, biomass, and fast growth of these plants, <I>P. calomelanos</I> and <I>P. vittata</I> were considered to be promising native plants for the phytoextraction of As contaminated soils. <I>Bidens pilosa</I> L. also has great potential for phytostabilization of mining soils contaminated with As and heavy metals.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Soils near multi-metal (W–F–Cu–Au–Bi) mine were contaminated with As, Cd, Cu. </LI> <LI> Arsenic in shoots were in order of Fern > Monocotyledonae > Dicotyledonae. </LI> <LI> <I>Pityrogramma calomelanos</I> and <I>Pteris vittata</I> L. suggested for phytoextraction of As. </LI> <LI> <I>Bidens pilosa</I> L. suggested for the phytostabilization of mining contaminated soils. </LI> </UL> </P>

Short Term Result of Anterior Approach with Liver Hanging Maneuver for Anatomical Resection: A Single Center Experience

( Giang Nguyen ),( Anh Pham ),( Trong Nguyen ),( Ha Nghiem ),( Hung Nguyen ),( Duc Pham ) 대한간학회 2020 춘·추계 학술대회 (KASL) Vol.2020 No.1

Aims: Anatomical liver resection is the treatment of choice for hepatocellular carcinoma (HCC). Anterior approach with liver hanging technique is useful to prevent the dissemmination of tumor cells to systemic circulation. Thus, we aim to evaluate the short term results of anterior approach with liver hanging maneuver for anatomical resection. Methods: A retrospective review of all patients with HCC who underwent anatomical resection from July 1 to December 20, 2019. The procedures were performed by 4 liver surgeons. Results: Among 9 patients, there were 5 men and 4 women. The mean age was 53.3 ±11.5 years. The right hepatectomy was performed in 5 patients, the right anterior sectionectomy in 2 patients, and ventral segment preserving right hepatectomy in 2 patients with small left lobe. Anterior approach with liver hanging maneuver was performed in all patients. The mean tumor size is 8.9 cm. Two patients had macrovascular invasion (right hepatic vein and right posterior portal vein). The mean operative time was 231.1 ± 37.2 minutes with a mean estimated blood loss of 303.3 ± 450.6 ml. Complications included 1 bilake (Clavien-Dindo grade II) and 1 acute portal vein thrombosis (grade IVa) were reported. The mean length of hospital staybil was 12.2 ± 8.4 days. There was no reported 30 days mortality. Conclusions: The anterior approach with liver hanging technique can be apply for various kind of anatomical resection. This procedure is technically safe and feasible.

Modified liver hanging maneuvers to facilitate various difficult types of hepatectomy: A single center experience

Giang NGUYEN,Anh PHAM,Trong NGUYEN,Hung NGUYEN,Ha NGHIEM,Duc PHAM 한국간담췌외과학회 2021 Annals of hepato-biliary-pancreatic surgery Vol.25 No.-

Modified Liver Hanging Maneuvers to Facilitate Various Difficult Types of Hepatectomy: A Single Center Experience

( Giang Nguyen ),( Anh Pham ),( Trong Nguyen ),( Hung Nguyen ),( Ha Nghiem ),( Duc Pham ) 대한간학회 2021 춘·추계 학술대회 (KASL) Vol.2021 No.1

Non-achievement of the Low-Density Lipoprotein Cholesterol Goal in Older Patients with Type 2 Diabetes Mellitus and a Very High Cardiovascular Disease Risk: A Multicenter Study in Vietnam

Huan Thanh Nguyen,Khang Pham Trong Ha,An Huu Nguyen,Thu Thanh Nguyen,Hang My Lam 대한노인병학회 2021 Annals of geriatric medicine and research Vol.25 No.4

Background: Lowering the low-density lipoprotein cholesterol (LDL-c) level is important for reducing cardiovascular (CV) events. However, little is known about the management of LDL-c in older patients with type 2 diabetes mellitus (T2DM). This study investigated the prevalence and factors associated with the non-achievement of LDL-c goals in older T2DM patients with a very high risk of CV diseases. Methods: This multicenter cross-sectional study measured the LDL-c levels of 733 T2DM outpatients from December 2019 to July 2020. The patients were aged ≥60 years, had very high risks of CV disease, and had been on LDL-c-lowering therapy for 6 months or more. The goal of lipid concentrations were assessed based on the recent guidelines of the European Society of Cardiology. We applied logistic regression analysis to identify the factors associated with the non-achievement of the LDL-c goal. Results: The mean age of the patients was 68.6±7.2 years. In total, 654 patients (89.2%) did not achieve the aggressive LDL-c goal of <1.4 mmol/L. In the adjusted model, the factors associated with the non-achievement of the LDL-c goal were obesity defined by body mass index (odds ratio [OR]=2.33; 95% confidence interval [CI], 1.13–4.81; p=0.022) and high-intensity statin therapy (OR=0.03; 95% CI, 0.01–0.05; p<0.001), while age, sex, education level, smoking habit, and comorbidities were not associated. Conclusion: Older patients with T2DM who are at a very high CV disease risk are often unable to achieve their LDL-c goal. Obesity can increase the probability of not achieving the LDL-c goal, whereas high-intensity statin therapy can decrease this probability.