Search results for: Nguyen The Hoang Anh

Authors: Le Nguyen Binh, Luong Xuan Binh, Le Van Tuan, Tran Binh Duong, Truong Nguyen Khanh Hung, Do Le Hoang Son, Pham Quang Vinh, Hoang Quoc Huy, Nguyen Bach, Nguyen Quoc Khanh Le, Jiunn Horng Kang

Abstract:

Introduction: Traumatic hip dislocation is an emergency in young adult which can cause avascular necrosis of femoral head or osteoarthritis of hip joint. The reasons for these may be the loose body of bony or chondral fragments, which are difficult to be detected on CT scan or MRI. In those cases, Hip arthroscopy may be the method of choice for diagnosis and treatment of loose bodies in hip joint after traumatic dislocation. Methods: A case report is performed. A 55-year-old male patient was under hip arthroscopy to retrieve the loose body in the right hip joint. Results: The patient’s hip was reduced under anesthesia in the opeation room. Xray and CT scan post-reduction showed that his right hip was wide and a small fragment of femoral head (< 5mm) locking inside the joint. A hip arthroscopy was done to take the fragment out. Post-operation, the patient went under rehabilition. After 6 months, he can walk with full-weight bearing; no further dislocaion was noted, and the Harris score was 84 points. Conclusions: Although acute traumatic injury of hip joint is usually treated with open surgeries, these methods have many drawbacks, such as soft tissue destruction, blood-loss,….Despite its technical requirement, hip arthroscopy is less invasive and effective treatment. Therefore, it may be an alternative treatment for a traumatic hip injury and can be applied frequently in the near future.

Keywords: hip dislocation, hip arthroscopy, hip osteoarthritis, acute hip trauma

Procedia PDF Downloads 84

Authors: Nguyen Chan Hung, Mai Ngoc Anh, Nguyen Xuan Ha, Tran Xuan Duc, Dang Bao Lam, Nguyen Hoang Viet

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This paper presents a design and implementation of a navigation controller for a humanoid mobile robot platform to operate in indoor office environments. In order to fulfil the requirement of recognizing and approaching human to provide service while avoiding random obstacles, a behavior-based fuzzy logic controller was designed to simultaneously coordinate multiple behaviors. Experiments in real office environment showed that the fuzzy controller deals well with complex scenarios without colliding with random objects and human.

Keywords: behavior control, fuzzy logic, humanoid robot, mobile robot

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Authors: Nguyen The Hoang Anh, Tran Huy Hoang, Vu Tat Thang, T. T. Quyen Bui

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Mental state classification is an important step for realizing a control system based on electroencephalography (EEG) signals which could benefit a lot of paralyzed people including the locked-in or Amyotrophic Lateral Sclerosis. Considering that EEG signals are nonstationary and often contaminated by various types of artifacts, classifying thoughts into correct mental states is not a trivial problem. In this work, our contribution is that we present and realize a novel model which integrates different techniques: Independent component analysis (ICA), relative wavelet energy, and support vector machine (SVM) for the same task. We applied our model to classify thoughts in two types of experiment whether with two or three mental states. The experimental results show that the presented model outperforms other models using Artificial Neural Network, K-Nearest Neighbors, etc.

Keywords: EEG, ICA, SVM, wavelet

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Authors: Hoang Van Ngoc, Nguyen Thu Huong, Nguyen Quang Bau

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Using the quantum kinetic equation for electrons interacting with acoustic phonon, the density of the constant current associated with the drag of charge carriers in cylindrical quantum wire by a linearly polarized electromagnetic wave, a DC electric field and a laser radiation field is calculated. The density of the constant current is studied as a function of the frequency of electromagnetic wave, as well as the frequency of laser field and the basic elements of quantum wire with a parabolic potential. The analytic expression of the constant current density is numerically evaluated and plotted for a specific quantum wires GaAs/AlGaAs to show the dependence of the constant current density on above parameters. All these results of quantum wire compared with bulk semiconductors and superlattices to show the difference.

Keywords: The photon-drag effect, the constant current density, quantum wire, parabolic potential

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Authors: E. Channol, O. Collet, N. Kostyuchyk, T. Mesbah, Quoc Hoang Long Nguyen

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In this paper, a pricing model is proposed for co-integrated commodities extending Larsson model. The futures formulae have been derived and tests have been performed with non-constant volatility. The model has been applied to energy commodities (gas, CO2, energy) and soft commodities (corn, wheat). Results show that non-constant volatility leads to more accurate short term prices, which provides better evaluation of value-at-risk and more generally improve the risk management.

Keywords: co-integration, soft commodities, risk management, value-at-risk

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Authors: Hoang Van Ngoc, Nguyen Vu Nhan, Nguyen Quang Bau

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The light-effect in cylindrical quantum wire with an infinite potential for the case of electrons, optical phonon scattering, is studied based on the quantum kinetic equation. The density of the direct current in a cylindrical quantum wire by a linearly polarized electromagnetic wave, a DC electric field, and an intense laser field is calculated. Analytic expressions for the density of the direct current are studied as a function of the frequency of the laser radiation field, the frequency of the linearly polarized electromagnetic wave, the temperature of system, and the size of quantum wire. The density of the direct current in cylindrical quantum wire with an infinite potential for the case of electrons – optical phonon scattering is nonlinearly dependent on the frequency of the linearly polarized electromagnetic wave. The analytic expressions are numerically evaluated and plotted for a specific quantum wire, GaAs/GaAsAl.

Keywords: the light–effect, cylindrical quantum wire with an infinite potential, the density of the direct current, electrons-optical phonon scattering

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Authors: Minh-Thuan Nguyen, Phuong-Thai Nguyen, Van-Vinh Nguyen, Quang-Minh Nguyen

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Research on automatically generating descriptions for e-commerce products is gaining increasing attention in recent years. However, the generated descriptions of their systems are often less informative and attractive because of lacking training datasets or the limitation of these approaches, which often use templates or statistical methods. In this paper, we explore a method to generate production descriptions by using the GPT-2 model. In addition, we apply text paraphrasing and task-adaptive pretraining techniques to improve the qualify of descriptions generated from the GPT-2 model. Experiment results show that our models outperform the baseline model through automatic evaluation and human evaluation. Especially, our methods achieve a promising result not only on the seen test set but also in the unseen test set.

Keywords: GPT-2, product description, transformer, task-adaptive, language model, pretraining

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Authors: Nguyen Huy Hoang, Do Thanh Quan, Tran Vu Kien

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The use of the active radar to measure the coordinates of ultra-light drones is frequently difficult due to long-distance, absolutely small radar cross-section (RCS) and obstacles. Since ultra-light drones are usually controlled by the Time Difference of Arrival (RF), the paper proposed a method to measure the coordinates of ultra-light drones in the space based on the arrival time of the signal at receiving antennas and the time difference of arrival (TDOA). The experimental results demonstrate that the proposed method is really potential and highly accurate.

Keywords: ultra-light drone, TDOA, radar cross-section (RCS), RF

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Authors: Khanh D.Do, Loi V.Nguyen, Thanh N.Nguyen, Thang M.Nguyen, Vu T.Tran

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Along with the development of Secondary surveillance radar (SSR) in air traffic surveillance systems, the Multipath phenomena has always been a noticeable problem. This following article discusses the geometrical aspect and power aspect of the Multipath interference caused by reflection in SSR and proposes a method to deal with these unwanted multipath targets (ghosts) by false-target position predicting and adaptive target suppressing. A field-experiment example is mentioned at the end of the article to demonstrate the efficiency of this measure.

Keywords: multipath, secondary surveillance radar, digital signal processing, reflection

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Authors: Nguyen Thi Hoang Hieu

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Mergers and Acquisitions (M&A) activities have increasingly become popular in both developed and developing countries. It is also an attractive topic for researchers to exploit in various sectors such as business, economies or finance. However, activities of Small and Medium Enterprises (SMEs) in M&A activities for a long time have not been sufficiently studied to provide the complete picture of what has been really, particularly in the developing market like Vietnam. The study employs semi-structured in-depth interviews with experts who have worked for years in the M&A sector to explore the participation motivation of both buy side and sell side of M&A activities. In addition, through the interviews, the study attempts to explain how firms finance their M&A deals. The collected data then will be content-analyzed to reflect the study's expectations based on the theories and practices reviews. In addition, limitations and recommendations are given in the hope that the M&A performance in Vietnam can be improved in the future.

Keywords: mergers and acquisitions, Vietnam, small and medium enterprises, content-analysis, semi-structure in-depth interview

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Authors: Anh Vo Van Ha, Yun Zhao, Luat Cong Nguyen, Tan Khac Chu, Phung Hoang Nguyen, Minh Ngoc Pham, Colin W. Binns, Andy H. Lee

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This study aims to study longitudinal changes in blood pressure (BP) during the 1-year postpartum period and to evaluate the influence of parity, maternal age at delivery, prepregnancy BMI, gestational weight gain, gestational age at delivery and postpartum maternal weight. A prospective longitudinal cohort study of 883 singleton Vietnamese women was conducted in Hanoi, Haiphong, and Ho Chi Minh City, Vietnam during 2015-2017. Women diagnosed with gestational diabetes mellitus at 24-28 weeks of gestation, pre-eclampsia, and hypoglycemia was excluded from analysis. BP was repeatedly measured at discharge, 6 and 12 months postpartum using automatic blood pressure monitors. Linear mixed model with repeated measures was used to describe changes occurring during pregnancy to 1-year postpartum. Parity, self-reported prepregnancy BMI, gestational weight gain, maternal age and gestational age at delivery will be treated as time-invariant variables and measured maternal weight will be treated as a time-varying variable in models. Women with higher measured postpartum weight had higher mean systolic blood pressure (SBP), 0.20 mmHg, 95% CI [0.12, 0.28]. Similarly, women with higher measured postpartum weight had higher mean diastolic blood pressure (DBP), 0.15 mmHg, 95% CI [0.08, 0.23]. These differences were both statistically significant, P < 0.001. There were no differences in SBP and DBP depending on parity, maternal age at delivery, prepregnancy BMI, gestational weight gain and gestational age at delivery. Compared with discharge measurement, SBP was significantly higher in 6 months postpartum, 6.91 mmHg, 95% CI [6.22, 7.59], and 12 months postpartum, 6.39 mmHg, 95% CI [5.64, 7.15]. Similarly, DBP was also significantly higher in 6 and months postpartum than at discharge, 10.46 mmHg 95% CI [9.75, 11.17], and 11.33 mmHg 95% CI [10.54, 12.12]. In conclusion, BP measured repeatedly during the postpartum period (6 and 12 months postpartum) showed a statistically significant increase, compared with after discharge from the hospital. Maternal weight was a significant predictor of postpartum blood pressure over the 1-year postpartum period.

Keywords: blood pressure, maternal weight, postpartum, Vietnam

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Authors: Duy Nguyen Do, Bart Julien Dewancker

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Many Soviet-style collective housing complexes (also known as KTT) were built since the 1960s in Hanoi to support the post-war population growth. Those low-rise buildings have created well-knitted, robust communities, so much to the point that in most complexes, all families in one housing block would know each other, occasionally interact and provide supports in need. To understand how the community of collective housing complexes have developed and maintained in order to adapt their advantages into modern housing designs, the study is executed on the site of Nguyen Cong Tru KTT. This is one of the oldest KTT in Hanoi, completed in 1954. The complex also has an unique characteristic that is closely related to its community: the symbiotic relationship with Hom – a flea market that has been co-developing with Nguyen Cong Tru KTT since its beginning. The research consists of three phases: the first phase is a sociological investigation with Nguyen Cong Tru KTT’s current residents and a site survey on the complex’s economic and architectural characteristics. In the second phase, the collected data is analyzed to find out people’s opinions with the KTT’s concerning their satisfaction with the current housing status, floor plan organization, community, the relationship between the KTT’s dedicated public spaces with the flea market and their usage. Simultaneously, the master plan and gathered information regarding current architectural characteristics of the complex are also inspected. On the third phase, the analyses’ results will provide information regarding the issues, positive trends and significant historical features of the complex’s architecture in order to generate suitable proposals for the redesigning project of Nguyen Cong Tru KTT, a design focused on vitalizing modern apartments’ communities.

Keywords: collective house community, collective house public space, community-focused, redesigning Nguyen Cong Tru KTT, sociological investigation

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Authors: Phong Nguyen, Phap Nguyen, Thang Nguyen

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High Efficiency Video Coding (HEVC) or H.265 Standard fulfills the demand of high resolution video storage and transmission since it achieves high compression ratio. However, it requires a huge amount of calculation. Since Motion Estimation (ME) block composes about 80 % of calculation load of HEVC, there are a lot of researches to reduce the computation cost. In this paper, we propose a new algorithm to lower the number of Motion Estimation’s searching points. The number of computing points in search pattern is down from 77 for Diamond Pattern and 81 for Square Pattern to only 31. Meanwhile, the Peak Signal to Noise Ratio (PSNR) and bit rate are almost equal to those of conventional patterns. The motion estimation time of new algorithm reduces by at 68.23%, 65.83%compared to the recommended search pattern of diamond pattern, square pattern, respectively.

Keywords: motion estimation, wide diamond, search pattern, H.265, test zone search, HM software

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Authors: Le-Quyen Nguyen, Hoang Van Bui, Ngoc Thi Tran, Binh Thanh Le, Linus Olson, Thanh Quang Le

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Objective: We compared of outcomes between infected and non-infected COVID-19 pregnant at the largest obstetrics and gynecology hospital in southern Vietnam. Materials and Methods: A retrospective study was conducted at gestational age (GA) 28-42 weeks, who terminated pregnancy and had a real-time PCR test for SARS-CoV-2 at Tu Du Hospital. Demographic, clinical, laboratory, and epidemiological data were collected from hospital electronic-medical-records. Diagnosis and screening of SARS-CoV-2 used Real-time-PCR. Results: From July to October 2021, 9,246 pregnant with GA of 28-42 weeks were delivered, including 664 infected with COVID-19 and 8,582 non-infected. The cesarean section (CS) rates of pregnant with and without COVID-19 were 47.3% and 46.0%. At GA 32-34 weeks, the rate of CS with COVID-19 was 5.07 times higher than without. The rate of postpartum hemorrhage (PPH) and the Apgar score between these two groups were similar. The mortality rate of infected pregnants was 2.26%. Conclusions: COVID-19 infection increased the CS rate in the group of preterm pregnancies from 32 to less than 34 weeks. COVID-19 did not increase the risk of complications related to adverse pregnancy outcomes such as PPH, Apgar scores, the ratio of stillbirths, deaths due to malformation, and fetal deaths in labor.

Keywords: COVID-19, SARS-CoV-2, pregnancy, outcome, vietnam

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Authors: Thanh Van Hoang, Tien Yin Chou, Yao Min Fang, Yi Min Huang, Xuan Linh Nguyen

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Reliable information on the spatial distribution of annual rainfall and temperature is essential in research projects relating to urban and regional planning. This research presents results of a classification of temperature and rainfall in the Red River Delta of northern Vietnam based on measurements from seven meteorological stations (Ha Nam, Hung Yen, Lang, Nam Dinh, Ninh Binh, Phu Lien, Thai Binh) in the river basin over a thirty-years period from 1982-2011. The average accumulated rainfall trends in the delta are analysed and form the basis of research essential to weather and climate forecasting. This study employs interpolation based on the Kriging Method for daily rainfall (min and max) and daily temperature (min and max) in order to improve the understanding of sources of variation and uncertainly in these important meteorological parameters. To the Kriging method, the results will show the different models and the different parameters based on the various precipitation series. The results provide a useful reference to assist decision makers in developing smart agriculture strategies for the Red River Delta in Vietnam.

Keywords: spatial interpolation method, ArcGIS, temperature variability, rainfall variability, Red River Delta, Vietnam

Procedia PDF Downloads 328

Authors: Nguyen Trong Nghia, Nguyen Huu Uy Vu, Dang Huu Phuoc, Sanjay Kumar Shukla, Le Gia Lam, Nguyen Van Cuong

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This paper introduces a matching scheme for selection of soil/drain properties in analytical solution and numerical modelling (axisymmetric and plane strain conditions) of a ground improvement project by using Prefabricated Vertical Drains (PVD) in combination with vacuum and surcharge preloading. In-situ monitoring data from a case history of a road construction project in Vietnam was adopted in the back-analysis. Analytical solution and axisymmetric analysis can approximate well the field data meanwhile the horizontal permeability need to be adjusted in plane strain scenario to achieve good agreement. In addition, the influence zone of the ground treatment was examined. The residual settlement was investigated to justify the long-term settlement in compliance with the design code. Moreover, the degree of consolidation of non-PVD sub-layers was also studied by means of two different approaches.

Keywords: numerical modelling, prefabricated vertical drains, vacuum consolidation, soft soil

Procedia PDF Downloads 229

Authors: D. T. Tran, H. P. Tran, L. G. Hoang, V. N. H. Bui, Q. T. Nguyen, A. K. Das

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This paper provides some insight information about a current situation of e-procurement implementation in Vietnam, including opportunities and challenges. A case study of Phuc Thien Company which is classified as a medium enterprise in the country, specialising on animal feed production. Since the technological development rapidly changes, companies have implemented advanced technologies in supply chain management to increase efficiency and gain collaboration amidst partners in their manufacturing and development activities. The findings of this research reveal strengths and ongoing weaknesses when Phuc Thien company internally implemented eProcurement system. Although cost savings, visibility of payment and speedy procurement process are one of the largest benefits of eProcurement implementation, the company faces greater hurdles, such as employee capability to use technology and their resistance to change, that overshadow everything else. In terms of governmental policy, the adaptation of e-invoicing has commenced since June 2015 in Vietnam, legal regulations and administrative framework related to e-Procurement carries various ambiguous in its content and extremely fragment. Hence, this adds a great burden to enterprises in general and Phuc Thien in particular in view of creating higher competitive advantage for animal feed industry in Vietnam as well as South East Asia region.

Keywords: procurement, e-procurement, animal feed industry, efficiency

Procedia PDF Downloads 332

Authors: X. L. Nguyen, T. Y. Chou, F. Y. Min, F. C. Lin, T. V. Hoang, Y. M. Huang

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In Vietnam, land use planning is utilized as an efficient tool for the local government to adjust land use. However, planned locations are facing disapproval from people who live near these planned sites because of environmental problems. The selection of these locations is normally based on the subjective opinion of decision-makers and is not supported by any scientific methods. Many researchers have applied Multi-Criteria Analysis (MCA) methods in which Analytic Hierarchy Process (AHP) is the most popular techniques in combination with Fuzzy set theory for the subject of rationality assessment of land use planning locations. In this research, the Fuzzy set theory and Analytic Network Process (ANP) multi-criteria-based technique were used for the assessment process. The Fuzzy Analytic Hierarchy Process was also utilized, and the output results from two methods were compared to extract the differences. The 20 planned landfills in Hung Ha district, Thai Binh province, Vietnam was selected as a case study. The comparison results indicate that there are different between weights computed by AHP and ANP methods and the assessment outputs produced from these two methods also slight differences. After evaluation of existing planned sites, some potential locations were suggested to the local government for possibility of land use planning adjusts.

Keywords: Analytic Hierarchy Process, Analytic Network Process, Fuzzy set theory, land use planning

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Authors: Hai Hoang, Thanh Xuan Nguyen Thi, Guillaume Galliero

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Coarse-Grained (CG) molecular simulations have shown to be an efficient way to estimate thermophysical (static and dynamic) properties of fluids. Several strategies have been developed and reported in the literature for defining CG molecular models. Among them, those based on a top-down strategy (i.e. CG molecular models related to macroscopic observables), despite being heuristic, have increasingly gained attention. This is probably due to its simplicity in implementation and its ability to provide reasonable results for not only simple but also complex systems. Regarding simple Force-Fields associated with these CG molecular models, it has been found that the four parameters Mie chain model is one of the best compromises to describe thermophysical static properties (e.g. phase diagram, saturation pressure). However, parameterization procedures of these Mie-chain GC molecular models given in literature are generally insufficient to simultaneously provide static and dynamic (e.g. viscosity) properties. To deal with such situations, we have extended the corresponding states by using a quantity associated with the liquid viscosity. Results obtained from molecular simulations have shown that our approach is able to yield good estimates for both static and dynamic thermophysical properties for various real non-associating fluids. In addition, we will show that on simple (e.g. phase diagram, saturation pressure) and complex (e.g. thermodynamic response functions, thermodynamic energy potentials) static properties, results of our scheme generally provides improved results compared to existing approaches.

Keywords: coarse-grained model, mie potential, molecular simulations, thermophysical properties, phase equilibria

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Authors: Hung Manh Nguyen, Duong Dai Nguyen

Abstract:

Objective: To evaluate the effects of Tai Chi exercise on cognitive performance of community-dwelling elderly in Vinh city, Vietnam. Design: A randomized controlled trial. Participants: One hundred and two subjected were recruited. Intervention: Subjects were divided randomly into two groups. Tai Chi group was assigned 6-months Tai Chi training. Control group was instructed to maintain their routine daily activities. Outcome measures: Trail Making Test (TMT) is primary outcome measure. Results: Participants in Tai Chi group reported significant improvement in TMT (part A) F(1, 71) = 78.37, p < .001, and in TMT (part B) F(1, 71)= 175.00, p < .001 in comparison with Control group. Conclusion: Tai Chi is beneficial to improve cognitive performance of the elderly.

Keywords: cognitive, elderly, Vietnam, Tai Chi

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Authors: Xuan Linh Nguyen, Tien Yin Chou, Yao Min Fang, Feng Cheng Lin, Thanh Van Hoang, Yin Min Huang

Abstract:

In Vietnam, land use planning is the most important and powerful tool of the government for sustainable land use and land management. Nevertheless, many of land use planning locations are facing protests from surrounding households due to environmental impacts. In addition, locations are planned completely based on the subjective decisions of planners who are unsupported by tools or scientific methods. Hence, this research aims to assist the decision-makers in evaluating the rationality of planning locations by developing a Spatial Decision Support System (SDSS) using approaches of Geographic Information System (GIS)-based technology, Analytic Hierarchy Process (AHP) multi-criteria-based technique and Fuzzy set theory. An ArcGIS Desktop add-ins named SDSS-LUPA was developed to support users analyzing data and presenting results in friendly format. The Fuzzy-AHP method has been utilized as analytic model for this SDSS. There are 18 planned locations in Hung Ha district (Thai Binh province, Vietnam) as a case study. The experimental results indicated that the assessment threshold higher than 0.65 while the 18 planned locations were irrational because of close to residential areas or close to water sources. Some potential sites were also proposed to the authorities for consideration of land use planning changes.

Keywords: analytic hierarchy process, fuzzy set theory, land use planning, spatial decision support system

Procedia PDF Downloads 378

Authors: Khue Nguyen Dinh, Loi Nguyen Van, Thanh Nguyen Nhu

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In this paper, we propose an adaptive method to resolve ambiguities and a ghost target removal process to extract targets detected by a ground-based pulse-Doppler radar using medium pulse repetition frequency (PRF) waveforms. The ambiguity resolution method is an adaptive implementation of the coincidence algorithm, which is implemented on a two-dimensional (2D) range-velocity matrix to resolve range and velocity ambiguities simultaneously, with a proposed clustering filter to enhance the anti-error ability of the system. Here we consider the scenario of multiple target environments. The ghost target removal process, which is based on the power after Doppler processing, is proposed to mitigate ghosting detections to enhance the performance of ground-based radars using a short PRF schedule in multiple target environments. Simulation results on a ground-based pulsed Doppler radar model will be presented to show the effectiveness of the proposed approach.

Keywords: ambiguity resolution, coincidence algorithm, medium PRF, ghosting removal

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Authors: Krasimir Ivanov, Elitsa Kolentsova, Nguyen Nguyen, Alexander Peltekov, Violina Angelova

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The nanosized zinc hydroxide nitrate has been recently estimated as perspective foliar fertilizer, which has improved zinc solubility, but low phytotoxicity, in comparison with ZnO and other Zn containing compounds. The main problem is obtaining of stable particles with dimensions less than 100 nm. This work studies the effect of preparation conditions on the chemical compositions and particle size of the zinc hydroxide nitrates, prepared by precipitation. Zn(NO3)2.6H2O and NaOH with concentrations, ranged from 0.2 to 3.2M and the initial OH/Zn ratio from 0.5 to 1.6 were used at temperatures from 20 to 60 °C. All samples were characterized in detail by X-ray diffraction, scanning electron microscopy, differential thermal analysis and ICP. Stability and distribution of the zinc hydroxide nitrate particles were estimated too.

Keywords: zinc hydroxide nitrate, nanoparticles, preparation, foliar fertilizer

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Authors: Huong M. T. Nguyen, Hoa A. P. Nguyen, Chi V. Phan, Mai P. T. Nguyen, Ngoc D. Ngo, Van T. Ta, Hai T. Le

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Wilson’s disease is an autosomal recessive disorder of copper metabolism, which is caused by mutation in copper- transporting P-type ATPase (ATP7B). The mechanism of this disease is a failure of hepatic excretion of copper to the bile, and it leads to copper deposits in the liver and other organs. Most clinical symptoms of Wilson’s disease can present as liver disease and/or neurologic disease. Objective: The goal of the study is prenatal diagnosis for pregnant women at high risk of Wilson’s disease in Northern Vietnam. Material and method: Three probands with clinically diagnosed liver disease were detected in the mutations of 21 exons and exon-intron boundaries of the ATP7B gene by direct Sanger-sequencing. Prenatal diagnoses were performed by amniotic fluid sampling from pregnant women in the 16th-18th weeks of pregnancy after the genotypes of parents with the probands were identified. Result: A total of three different mutations of the probands, including of S105*, P1052L, P1273G, were detected. Among three fetuses which underwent prenatal genetic testing, one fetus was homozygote; two fetuses were carriers. Conclusion: Genetic testing provided a useful method for prenatal diagnosis, and is a basis for genetic counseling.

Keywords: ATP7B gene, genetic testing, prenatal diagnosis, pedigree, Wilson disease

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Authors: Nguyen Quang Kim, Nguyen Thu Hien, Nguyen Thien Dung

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Flood disasters are increasing worldwide in both frequency and magnitude. Every year in Vietnam, flood causes great damage to people, property, and environmental degradation. The flood risk management policy in Vietnam is currently updated. The planning of flood mitigation strategies is reviewed to make a decision how to reach sustainable flood risk reduction. This paper discusses the basic approach where the measures of flood protection are chosen based on minimizing the present value of expected monetary expenses, total residual risk and costs of flood control measures. This approach will be proposed and demonstrated in a case study for flood risk management in Vinh Phuc province of Vietnam. Research also proposed the framework to find a solution of optimal protection level and optimal measures of the flood. It provides an explicit economic basis for flood risk management plans and interactive effects of options for flood damage reduction. The results of the case study are demonstrated and discussed which would provide the processing of actions helped decision makers to choose flood risk reduction investment options.

Keywords: drainage plan, flood planning, flood risk, residual risk, risk optimization

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Authors: Edwin Lerch, Dirk Audring, Cuong Nguyen Mau, Duc Ninh Nguyen, The Cuong Nguyen, The Van Nguyen

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The National Load Dispatch Centre of Electricity Vietnam (EVNNLDC) and Siemens PTI investigated the stability of the electrical 500/220 kV transportation system of Vietnam. The general scope of the investigations is improving the stability of the Vietnam power system and giving the EVNNLDC staff the capability to decide how to deal with expected stability challenges in the future, which are related to the very fast growth of the system. Rapid system growth leads to a very high demand of power transmission from North to South. This was investigated by stability studies of interconnected power system with neighboring countries. These investigations are performed in close cooperation and coordination with the EVNNLDC project team. This important project includes data collection, measurement, model validation and investigation of relevant stability phenomena as well as training of the EVNNLDC staff. Generally, the power system of Vietnam has good voltage and dynamic stability. The main problems are related to the longitudinal system with more power generation in the North and Center, especially hydro power, and load centers in the South of Vietnam. Faults on the power transmission system from North to South risks the stability of the entire system due to a high power transfer from North to South and high loading of the 500 kV backbone. An additional problem is the weak connection to Cambodia power system which leads to interarea oscillations mode. Therefore, strengthening the power transfer capability by new 500kV lines or HVDC connection and balancing the power generation across the country will solve many challenges. Other countermeasures, such as wide area load shedding, PSS tuning and correct SVC placement will improve and stabilize the power system as well. Primary frequency reserve should be increased.

Keywords: dynamic power transmission system studies, blackout prevention, power system interconnection, stability

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Authors: My Linh Hoang, Van Dung Hoang

Abstract:

Environmental, Social, and Governance (ESG) factors have become a focus for companies globally, as businesses are now focusing on long-term sustainable goals rather than only operating for the goals of profit maximization. According to recent research, in several countries, companies have shown positive results in their financial performance by improving their ESG performance. The construction industry is one of the most crucial components of social and economic development; as a result, considerations for ESG factors are becoming more and more essential for companies in this sector. In Vietnam, the construction industry has been growing rapidly in recent years; however, it has yet to be discussed and studied extensively in Vietnam how ESG factors create impacts on corporate financial performance in general and construction corporations’ financial performance in particular. This research aims to examine the relationship between ESG factors and financial indicators in construction companies from 2011 to 2021 through panel data analysis of 75 listed construction companies in Vietnam and to provide insights into how these companies can better integrate ESG considerations into their operations to enhance their financial performance. The data was analyzed through 3 main methods: descriptive statistics, correlation coefficient analysis applied to all dependent, explanatory and control variables, and panel data analysis method. In panel data analysis, the study uses the fixed effects model (FEM) and random effects model (REM). The Hausman test will be used to select which model is suitable to be used. The findings indicate that maintaining a strong commitment to ESG principles can have a positive impact on financial performance. Finally, FGLS estimation will be performed when the problem of autocorrelation and variable variance appears in the model. This is significant for all parties involved, including investors, company managers, decision-makers, and industry regulators.

Keywords: ESG, financial performance, construction company, Vietnam

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Authors: Linh Nguyen Tung, Anh Truong Viet, Nghien Nguyen Ba, Chuong Trinh Trong

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This paper proposes a reconfiguration methodology based on a continuous genetic algorithm (CGA) and particle swarm optimization (PSO) for minimizing active power loss and minimizing voltage deviation. Both algorithms are adapted using graph theory to generate feasible individuals, and the modified crossover is used for continuous variable of CGA. To demonstrate the performance and effectiveness of the proposed methods, a comparative analysis of CGA with PSO for network reconfiguration, on 33-node and 119-bus radial distribution system is presented. The simulation results have shown that both CGA and PSO can be used in the distribution network reconfiguration and CGA outperformed PSO with significant success rate in finding optimal distribution network configuration.

Keywords: distribution network reconfiguration, particle swarm optimization, continuous genetic algorithm, power loss reduction, voltage deviation

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Authors: Tai Nguyen, Minh Bui, Huong Ninh, Tu Nguyen, Hai Tran

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GraphCut algorithm has been widely utilized to solve various types of computer vision problems. Its expensive computational cost encouraged many researchers to improve the speed of the algorithm. Recent works proposed schemes that work on parallel computing platforms such as CUDA. However, the problem of low convergence speed prevents the usage of GraphCut for real time applications. In this paper, we propose global suppression heuristic to boost the conver-gence process of the algorithm. A parallel implementation of GraphCut algorithm on CUDA designed for the image stitching problem is introduced. Our method achieves up to 3× time boost on the graph of size 80 × 480 compared to the best sequential GraphCut algorithm while achieving satisfactory stitched images, suitable for panorama applications. Our source code will be soon available for further research.

Keywords: CUDA, graph cut, image stitching, texture synthesis, maxflow/mincut algorithm

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Authors: Nguyen Van Que, Nguyen Huy The

Abstract:

This paper presents combined natural and forced convection of humid air flow. The film condensation of water vapour on a cold floor was investigated using ANSYS Fluent software. User-defined Functions(UDFs) were developed and added to address the issue of film condensation at the surface of the floor. Those UDFs were validated by analytical results on a flat plate. The film condensation model based on mass transfer was used to solve phase change. On the floor, condensation rate was obtained by mass fraction change near the floor. The study investigated effects of inlet velocity, inlet relative humidity and cold floor temperature on the condensation rate. The simulations were done in both 2D and 3D models to show the difference and need for 3D modeling of condensation.

Keywords: heat and mass transfer, convection, condensation, relative humidity, user-defined functions

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