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Behavior of noncircular tunnels excavated in stratified rock masses-Case of underground coal mines

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Journal of Rock Mechanics and Geotechnical Engineering 2019年第1期11卷 99-110页

作者： Ngoc Anh Do Daniel Dias van Diep dinh Tien Tung Tran van Canh Dao Viet Doan Dao phuc Nhan Nguyen Department of Underground and Mining Construction.Faculty of Civil Engineering Hanoi University of Mining and Ceology School of Automotive and Transportation Engineering Hefei University of Technology Laboratory 35R Crenoble Alpes University

The amount of tunnels excavated along stratified/sedimentary rock masses in Quangninh coal mine area,Vietnam, is gradually increasing. Rock mass in Quangninh is characterized by beddings between rock layers. The behavior of stratified rock masses surrounding the tunnels depends on both the intact rock and the beddings between rock layers. The main characteristics of stratified rock masses that need to be considered are their heterogeneity and anisotropy. Depending on the dip angle of rock layers, movements and failure zones developed surrounding the tunnels can be asymmetrical over the vertical axis of tunnel. This asymmetry causes adverse behaviors of the tunnel structures. The objective of this study is to highlight convergences and yielded zones developed in rock masses surrounding noncircular tunnels in Quangninh coal mine area using a finite element method. The presence of bedding joints is explicitly simulated. The numerical results indicated that with the increase in dip angle of bedding joints, the stress asymmetry over the tunnel vertical axis increases. It gradually leads to an asymmetry of the failure zone surrounding the tunnel. An increase of rock mass quality means a decrease of rock mass sensitivity to the discontinuities. In addition,a dip angle of the bedding joints of approximately 45° could be considered as the critical angle at which the rock mass mechanism changes between sliding and bending.

关键词： Tunnel Bedding Stratification Anisotropic Heterogeneity

STRONG INSTABILITY OF STANDING WAVES FOR A SYSTEM NLS WITH QUADRATIC INTERACTION

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Acta Mathematica Scientia 2020年第2期40卷 515-528页

作者： van Duong dinh Laboratoire Paul PainleveUMR 8524 Universitede Lille CNRS59655 Villeneuve d'AscqCedexFrance Department of Mathematics HCMC University of Pedagogy280 An Duong VuongHo Chi MinhVietnam

We study the strong instability of standing waves for a system of nonlinear Schr¨odinger equations with quadratic interaction under the mass resonance condition in dimension d=5.

关键词： System NLS quadratic interaction ground states instability blow-up

Scheduling Flexible Flow Shop in Labeling Companies to Minimize the Makespan

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Computer Systems Science & Engineering 2022年第1期40卷 17-36页

作者： Chia-Nan Wang Hsien-Pin Hsu Hsin-Pin Fu Nguyen Ky phuc Phan van Thanh Nguyen Department of Industrial Engineering and Management National Kaohsiung University of Science and TechnologyKaohsiung80778Taiwan Department of Supply Chain Management National Kaohsiung University of Science and TechnologyKaohsiung80778Taiwan Department of Marketing and Distribution Management National Kaohsiung University of Science and TechnologyKaohsiung80778Taiwan Faculty of Industrial Engineering and Management International UniversityHo Chi Minh City70000Vietnam Faculty of Commerce Van Lang UniversityHo Chi Minh City723000Vietnam

In the competitive global marketplace,production scheduling plays a vital role in planning in *** deals directly with the time to output products quickly and with a low production *** research examines case study of a Radio-Frequency Identification labeling department at Avery *** main objective of the company is to have a method that allows for the sequencing and scheduling of a set of jobs so it can be completed on or before the customer’s due date to minimize the number of late *** study analyzes the flexible flow shop scheduling problem with a sequence dependent setup by modifying the processing time and setup time to minimize the makespan on multiple *** on the defined mathematical model,this study includes an alternative approach and application of heuristic algorithm with the input being big *** optimization programs are used in this study and compared to determine which method can better solve the company’s *** proposed algorithm is able to improve machine utilization with large-scale problems.

关键词： Scheduling flexibleflowshop sequencedependentsetup just-in-time

Mechanical characteristics of tensile strength ratio method compared to other parameters used for moisture susceptibility evaluation of asphalt mixtures

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Journal of Traffic and Transportation Engineering(English Edition) 2019年第6期6卷 621-630页

作者： Thanh Chung Do van phuc Tran van phuc Le Hyun Jong Lee Won Jae Kim Department of Civil and Environmental Engineering Sejong UniversitySeoul 143-747South Korea Faculty of Civil Engineering University of Transport and CommunicationsHo Chi Minh CityVietnam

In this study,mechanical characteristics of tensile strength ratio(TSR)were evaluated by comparing it to other methods in evaluating moisture sensitivity of asphalt *** types of asphalt mixtures with and without anti-stripping additives were prepared and tested in the *** compressive strength(UCS)and indirect tensile(IDT)testing were conducted to determine the mixture’s tensile strength ratio and cohesion ratio(CR).Determining TSR alone was found to be insufficient when evaluating moisture *** is a need to consider both TSR and wet IDT strength to properly evaluate moisture behavior of asphalt ***,it was found that the cohesion and the IDT strength have a good relation in which the minimum condition of the slope,must be ***,it was observed thatβvalues change depending on material type and ***,there is a need to evaluate theseβvalues for varying material and testing *** addition,it was found that the TSR and CR results are highly correlated with an average difference of 1.5%.Furthermore,other tests such as Marshall stability and dynamic immersion were also *** was found that Marshall stability ratio(MSR)and Marshall stability to flow ratio(MSFR)values are less sensitive to moisture effect when measuring moisture resistance compared to TSR ***,the 48 h testing result of the dynamic immersion test showed better correlation with TSR values.

关键词： Asphalt mixtures Moisture damage Anti-stripping additives Tensile strength ratio Cohesion strength ratio

Off-the-shelf mesenchymal stem cells from human umbilical cord tissue can significantly improve symptoms in COVID-19 patients: An analysis of evidential relations

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World Journal of Stem Cells 2020年第8期12卷 721-730页

作者： phuc van Pham Ngoc Bich Vu Stem Cell Institute University of ScienceHo Chi Minh 08000Viet Nam Vietnam National University Ho Chi Minh 08000Viet Nam

Coronavirus disease-2019(COVID-19)has affected more than 200 countries *** disease has hugely affected healthcare systems as well as the economy to an extent never seen *** date,COVID-19 infection has led to about 165000 deaths in 150 *** present,there is no specific drug or efficient treatment for this *** this analysis based on evidential relationships of the biological characteristics of MSCs,especially umbilical cord(UC)-derived MSCs as well as the first clinical trial using MSCs for COVID-19 treatment,we discuss the use of UC-MSCs to improve the symptoms of COVID-19 in patients.

关键词： Coronavirus COVID-19 Mesenchymal stem cells Umbilical cord-derived mesenchymal stem cells

On Mixed Multiplicities of Good Filtrations

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Algebra Colloquium 2015年第3期22卷 421-436页

作者： Duong Quoc Viet Le van dinh Department of Mathematics Hanoi National University of Education 136 Xuan Thuy Street Hanoi Vietnam

This paper interprets mixed multiplicities of good filtrations as Hilbert-Samuel multiplicities, and shows that （ε1,..., εm）-superficial sequences in [16] （2007） and superficial sequences in [15] （1973） are weak-（FC）-sequences in [19] （2000）. As consequences, we not only obtain generalized results for mixed multiplicities of ideals in [15, 16, 19] but also get an improvement of [19, Theorem 3.4] that seems to account well for the essence of [16, Theorem 1.4].

关键词： mixed multiplicity filtration (FC)-sequence superficial sequence

The effectiveness of light emitting diode(LED)lamps in the offshore purse seine fishery in Vietnam

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Aquaculture and Fisheries 2023年第5期8卷 551-557页

作者： Nguyen Dang Nhat Do Thanh Tien Truong van Dan Nguyen Duy Quynh Tram Nguyen Quang Lich Ho Dang phuc Nguyen Ngoc Phuoc School of Engineering and Technology Hue University01 Dien Bien PhuHue City52000Viet Nam Faculty of Engineering and Food Technology University of Agriculture and ForestryHue University102 Phung HungHue City52000Viet Nam Faculty of Fisheries University of Agriculture and ForestryHue University102 Phung HungHue City52000Viet Nam Institute of Mathematics Vietnam Academy of Science and Technology18 Hoang Quoc VietCau Giay DistrictHanoi11300Viet Nam

Fishing with artificial light has become one of the most advanced,efficient,and common methods for the night-time purse seining in *** study evaluated the radiation spectrum,CIE chromaticity coordinates,correlated color temperature(CCT),catch rate,fuel consumption,and CO_(2)emissions when using Light emitting diode(LED)lamps(0.196 kW)in comparison with the use of metal halide(MH)lights(1 kW)in the offshore purse seine fishery in Quang Tri province,*** fishing efficiency of the purse seine fishing boats using LED lamps has increased 1.58 times in catch rate than MH lights,although the energy consumption of LED lamp is 4 times *** consumption of boats per trip using LED lamps was one third of that using MH *** use of LED reduced the radiation spectrum,especially the intense UV radiation which negatively affects the health of *** study also showed the potential of CO_(2)emission reduction up to 1.09 tons of CO_(2)per trip per boat from the use of LED lamps in the offshore purse seine fishing boats.

关键词： Light emitting diode(LED)lamp Metal halide(MH)light Offshore purse seine fishery Quang tri province Vietnam

An analytical model for cross-Kerr nonlinearity in a four-level N-type atomic system with Doppler broadening

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Chinese Physics B 2022年第2期31卷 314-319页

作者： dinh Xuan Khoa Nguyen Huy Bang Nguyen Le Thuy An Nguyen van Phu Le van Doai Vinh University 182 Le Duan StreetVinh CityVietna

We present an analytical model for cross-Kerr nonlinear coefficient in a four-level N-type atomic medium under Doppler *** model is applied to87 Rb atoms to analyze the dependence of the cross-Kerr nonlinear coefficient on the external light field and the temperature of atomic *** analysis shows that in the absence of electromagnetically induced transparency(EIT)the cross-Kerr nonlinear coefficient is zero,but it is significantly enhanced when the EIT is *** means that the cross-Kerr effect can be turned on/off when the external light field is on or ***,the amplitude and the sign of the cross-Kerr nonlinear coefficient are easily changed according to the intensity and frequency of the external light *** amplitude of the cross-Kerr nonlinear coefficient remarkably decreases when the temperature of atomic medium *** analytical model can be convenient to fit experimental observations and applied to photonic devices.

关键词： electromagnetically induced transparency Kerr nonlinear effect Doppler effect

Regularization of the Inverse Problem for Time Fractional Pseudo-parabolic Equation with Non-local in Time Conditions

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Acta Mathematica Sinica,English Series 2022年第12期38卷 2199-2219页

作者： Nguyen Duc PHUONG Le dinh LONG Anh Tuan NGUYEN Dumitru BALEANU Faculty of Fundamental Science Industrial University of Ho Chi Minh CityVietnam Division of Applied Mathematics Science and Technology Advanced InstituteVanLang UniversityHoChi Minh CityVietnam Faculty of Technology Van Lang UniversityHo Chi Minh CityVietnam Department of Mathematics Cankaya UniversityAnkaraTurkey Lebanese AmericanUniversity BeirutLebanon Institute of Space Sciences Magurele-BucharestRomania

This paper is devoted to identifying an unknown source for a time-fractional diffusion equation in a general bounded ***,we prove the problem is non-well posed and the stability of the source ***,by using the Modified Fractional Landweber method,we present regularization solutions and show the convergence rate between regularization solutions and sought solution are given under a priori and a posteriori choice rules of the regularization parameter,***,we present an illustrative numerical example to test the results of our theory.

关键词： Source problem fractional pseudo-parabolic problem ill-posed problem convergence estimates regularization