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Investigation of Punch Resistance of the Allomyrira dichtoloma Beetle Forewing

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Journal of Bionic Engineering 2018年第1期15卷 57-68页

作者： Ngoc San ha vinh Tung Le Nam Seo Goo Smart Microsystem Research Laboratory Department of Advanced Technology Fusion Division of Interdisciplinary Studies Konkuk University Seou105029 Republic of Korea Faculty of Science Engineering and Technology Swinburne University of Technology Hawthorn VIC 3122 Australia

In this study, the punch resistance of the beetle forewing was investigated to address the ability of the forewing against the external force. The punch resistance of the forewing was measured for different sizes and sexes of beetles using a conventional testing method in conjunction with the Digital Image Correlation （DIC） technique. The results showed that the maximum fracture load was measured around 23 N for the female beetle and around 20.2 N for the male beetle in the front-side punch test. Moreover, the fracture load in the front-side punch test was higher than that in the back-side punch test for both male and female beetles. This means that the beetle forewing plays a protection role against external loads. Furthermore, the puncture energy in the front-side punch test for the female beetle （6.91 m J） was a little higher than that for the male beetle （5.27 mJ）. In addition, the DIC results revealed that the first crack occurred along the trachea line and the second crack then appeared in the direction that was perpendicular to the direction of the first crack. This study provides a com- prehensive understanding of the mechanical protection properties of the beetle forewing and offers a good lesson for studying lightweight bio-inspired composite material.

关键词： beetle forewing punch test punch energy digital image correlation

Detecting Tuberculosis from Vietnamese X-Ray Imaging Using Transfer Learning Approach

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Computers, Materials & Continua 2023年第3期74卷 5001-5016页

作者： ha Manh Toan Lam Thanh Hien Ngo Duc vinh Do Nang Toan Institute of Information Technology–Vietnam Academy of Science and Technology Hanoi10072Vietnam Lac Hong University Bien HoaDong Nai76120Vietnam hanoi University of Industry Hanoi11915Vietnam

Deep learning created a sharp rise in the development of autonomous image recognition systems,especially in the case of the medical *** lung problems,tuberculosis,caused by a bacterium called Mycobacterium tuberculosis,is a dangerous disease because of its infection and *** an infected person coughs or sneezes,tiny droplets can bring pathogens to others through *** mainly damages the lungs,but it also affects any part of the ***,during the period of the COVID-19(coronavirus disease 2019)pandemic,the access to tuberculosis diagnosis and treatment has become more difficult,so early and simple detection of tuberculosis has been more and more *** our study,we focused on tuberculosis diagnosis by using the chestX-ray image,the essential input for the radiologist’s profession,and researched the effectiveness of the transfer learning approach in the case study of Vietnamese chest X-ray *** proposed four strategies to clarify our hypothesis in different ways of applying transfer learning and different training set *** also prepared a Vietnamese X-ray image dataset with the support of the VRPACS team to provide the basis for training and testing deep learning *** experiments were carried out by applying three different architectures,Alexnet,Resnet,and Densenet,on international,Vietnamese,and combined X-ray image *** training,all models were verified on a pure Vietnamese X-rays *** results show that transfer learning is suitable in the case study of Vietnamese chest X-ray images with high evaluating metrics in terms of AUC(Area under the Receiver Operating Characteristic Curve),sensitivity,specificity,and *** the best strategy,most of the scores were more than 0.93,and all AUCs were more than 0.98.

关键词： Tuberculosis diagnosis transfer learning Vietnamese chest X-ray

Engine performance and combustion characteristics of a direct injection compression ignition engine fueled waste cooking oil synthetic diesel

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International Journal of Coal Science & Technology 2020年第3期7卷 560-570页

作者： Thanh Viet Nguyen Khanh Duc Nguyen Nang xuan Ho vinh Duy Nguyen Department of Internal Combustion Engine School of Transportation EngineeringHanoi University of Science and TechnologyHanoiViet Nam Faculty of Vehicle and Energy Engineering Phenikaa UniversityYen NghiaHa-Dong DistrictHanoiViet Nam

Biodiesels produced from various feedstocks have been considered as alternative fuels used in internal combustion engines without major *** research focuses on producing biodiesel from waste cooking oil(WCOSD)by the catalytic cracking method using MgO as the catalyst and comparing the engine operating characteristics of the test engine when using WCOSD and traditional diesel(CD)as test *** a result,the brake power of the test engine fueled WCOSD,and traditional diesel is ***,the engine fuel consumption in the case of using WCOSD is slight increases in some operating ***,the nitrogen oxides emissions of the test engine fueled WCOSD are higher than those of CD at all tested *** trend is opposite for hydrocarbon emission as the HC emission of the engine fueled by WCOSD reduces 26.3%on *** smoke emission of the test engine in case of using WCOSD is lower 17%on average than that of ***,the carbon monoxide emissions are lower at the low and medium loads and higher at the full *** results show that the new biodiesel has the same characteristics as those of commercial biodiesel and can be used as fuel for diesel engines.

关键词： Feedstock Waste cooking oil Engine characteristics Exhaust missions Ignition timing Fuel consumption

Dynamic spillovers between the term structure of interest rates,bitcoin,and safe‑haven currencies

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Financial Innovation 2021年第1期7卷 1334-1358页

作者： David Y.Aharon Zaghum Umar xuan vinh Vo Department of Business Administration Ono Academic CollegeZahal 104 Street5545173 Kiryat OnoIsrael College of Business Zayed UniversityAbu DhabiUAE Institute of Business Research University of Economics Ho Chi Minh CityHo Chi Minh CityVietnam

This study examines the connectedness between the US yield curve components(i.e.,level,slope,and curvature),exchange rates,and the historical volatility of the exchange rates of the main safe-haven fiat currencies(Canada,Switzerland,EURO,Japan,and the UK)and the leading cryptocurrency,the *** of the static analysis show that the level and slope of the yield curve are net transmitters of shocks to both the exchange rate and its *** exchange rate of the Euro and the volatility of the Euro and the Canadian dollar exchange rate are net transmitters of ***,the curvature of the yield curve and the Japanese Yen,Swiss Franc,and British Pound act mainly as net *** static connectedness analysis shows that Bitcoin is mainly independent of shocks from the yield curve’s level,slope,and curvature,and from any main currency *** findings hint that Bitcoin might provide hedging ***,similar to the static analysis,our dynamic analysis shows that during different periods and particularly in stressful times,Bitcoin is far from being isolated from other currencies or the yield curve *** dynamic analysis allows us to observe Bitcoin’s connectedness in times of *** supporting this contention is the substantially increased connectedness due to policy shocks,political uncertainty,and systemic crisis,implying no empirical support for Bitcoin’s safe-haven property during stress *** increased connectedness in the dynamic analysis compared with the static approach implies that in normal times and especially in stressful times,Bitcoin has the property of a *** results may have important implications for investors and policymakers regarding their risk monitoring and their assets allocation and investment strategies.

关键词： Bitcoin Term structure slope Curvature Diebold and Yilmaz Connectedness Cryptocurrency Forex Currencies Safe haven

Effectiveness of bee venom acupuncture for patients suffering from periarthritis humeroscapularis

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Journal of Traditional Chinese Medicine 2023年第4期43卷 795-800页

作者： Minh Duc Nguyen Thanh Van Tran Quoc vinh Nguyen Cay Doan ha Linh Vu Phuong Dang Senior Specialist Clinic National Hospital of AcupunctureHanoi 1000Vietnam Department of Senior Specialist National Hospital of Acupuncture Hanoi 1000Vietnam Department of Senior Specialist Military Institute of Traditional MedicineHanoi 1000Vietnam Department of minimally invasive spine National Hospital of AcupunctureHanoi 1000Vietnam Department of Medicine Dai Nam UniversityHanoi 1000Vietnam

OBJECTIVE:To evaluate the efficacy of bee venom acupuncture in humeroscapularis(PHS)***:One hundred and twenty patients diagnosed with PHS were assigned into four groups:BV1(0.01 mg/kg),BV2(0.005 mg/kg),BV3(0.0025 mg/kg),and control group(vitamin B1 plus novocain 3%injection)with 15 d of *** outcomes of the study including visual analogue scale(VAS)score andβ-endorphin,inflammatory cytokines including interleukin-10(IL-10),IL-1βand tumor necrosis factorα(TNF-α)and shoulder function score were assessed at baseline,after 10 and 15 d of ***:All four groups reported statistically significant improvement in VAS score,motion range,and shoulder function score(Phan current therapy used in Vietnam and other groups.

关键词： periarthritis humeroscapularis bee venom acupuncture visual analogue scale range of motion articular shoulder function score inflammatory cytokines

Extreme dependencies and spillovers between gold and stock markets:evidence from MENA countries

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Financial Innovation 2023年第1期9卷 1449-1475页

作者： Walid Mensi Debasish Maitra Refk Selmi xuan vinh Vo Department of Economics and Finance College of Economics and Political ScienceSultan Qaboos UniversityMuscatOman Institute of Business Research University of Economics Ho Chi Minh CityHo Chi Minh CityVietnam Indian Institute of Management Indore IndoreIndia ESC Pau Business School PauFrance Institute of Business Research and CFVG University of Economics Ho Chi Minh CityHo Chi Minh CityVietnam

This study addresses whether gold exhibits the function of a hedge or safe haven as often referred to in *** contributes to the existing literature by(i)revisiting this question for the principal stock markets in the Middle East and North Africa(MENA)region and(ii)using the copula-quantile-on-quantile and conditional value at risk methods to detail the risks facing market participants provided with accurate information about various gold and stock market scenarios(i.e.,bear,normal,bull).The results provide strong evidence of quantile dependence between gold and stock *** correlations are found between MENA gold and stock markets when both are ***,when stock returns are bearish,gold markets show negative correlations with MENA stock *** risk spillover from gold to stock markets intensified during the global financial and European *** the risk spillover between gold and stock markets,investors in MENA markets should be careful when considering gold as a safe haven because its effectiveness as a hedge is not the same in all MENA stock *** and portfolio managers should rebalance their portfolio compositions under various gold and stock market ***,such precise insights about the heterogeneous linkages and spillovers between gold and MENA stock returns provide potential input for developing effective hedging strategies and optimal portfolio allocations.

关键词： Copula CoVaR Extreme dependence Gold MENA markets Risk spillovers

EXISTENCE AND STABILITY OF PERIODIC AND ALMOST PERIODIC SOLUTIONS TO THE BOUSSINESQ SYSTEM IN UNBOUNDED DOMAINS

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Acta Mathematica Scientia 2022年第5期42卷 1875-1901页

作者： Thieu Huy NGUYEN Truong xuan PhaM Thi Ngoc ha VU The Sac LE School of Applied Mathematics and Informatics Hanoi University of Science and Technology Vien Toan ung dung va Tin hocDai hoc Bach khoa Hanoi 1DaiCoVietHanoiVietnam Department of Mathematics Faculty of Information TechnologyThuyloi university Khoa Cong nghe Thong tinBo mon ToanDai hoc Thuy loi175 Tay SonDong DaHa NoiViet Nam Thuyloi University Dai hoc Thuy Loi175 Tay SonDong DaHanoiViet Nam

In this paper we investigate the existence and stability of periodic solutions(on a half-line R_(+))and almost periodic solutions on the whole line time-axis R to the Boussinesq system on several classes of unbounded domains of R^(n) in the framework of interpolation *** the linear Boussinesq system we combine the L^(p)—L^(q)-smoothing estimates and interpolation functors to prove the existence of bounded mild ***,we prove the existence of periodic solutions by invoking Massera’s *** also prove the existence of almost periodic *** we use the results of the linear Boussinesq system to establish the existence,uniqueness and stability of the small periodic and almost periodic solutions to the Boussinesq system using fixed point arguments and interpolation *** results cover and extend the previous ones obtained in[13,34,38].

关键词： Boussinesq systems periodic solutions almost periodic solutions unbounded domains smoothing estimates dual estimates interpolation spaces stability

Development of a PARCS/Serpent model for neutronics analysis of the Dalat nuclear research reactor

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Nuclear Science and Techniques 2021年第2期32卷 32-44页

作者： Viet-Phu Tran Kien-Cuong Nguyen Donny hartanto Hoai-Nam Tran vinh Thanh Tran Van-Khanh Hoang Pham Nhu Viet ha Institute for Nuclear Science and Technology(INST) Vietnam Atomic Energy Institute(VINATOM)179 Hoang Quoc Viet str.Cau Giay DistrictHanoi 100000Vietnam Nuclear Research Institute(NRI) Vietnam Atomic Energy Institute(VINATOM)01 Nguyen Tu LucDalatLamdong 670000Vietnam Department of Mechanical and Nuclear Engineering University of SharjahPO.BOX 27272SharjahUnited Arab Emirates Institute of Fundamental and Applied Sciences Duy Tan UniversityHo Chi Minh city 700000Vietnam Faculty of Natural Science Duy Tan UniversityDanang 550000Vietnam Nuclear Safety Division Technical Support Center for Radiation and Nuclear Safety and Emergency ResponseVietnam Agency for Radiation and Nuclear Safety(VARANS)113 Tran Duy Hung str.Cau Giay DistrictHanoi 100000Vietnam

Cross-sectional homogenization for full-core calculations of small and complex reactor configurations,such as research reactors,has been recently recognized as an interesting and challenging *** paper presents the development of a PARCS/Serpent model for the neutronics analysis of a research reactor type TRIGA Mark-II loaded with Russian VVR-M2 fuel(known as the Dalat Nuclear Research Reactor or DNRR).The full-scale DNRR model and a supercell model for a shim/safety rod and its surrounding fuel bundles with the Monte Carlo code Serpent 2 were proposed to generate homogenized fewgroup cross sections for full-core diffusion calculations with *** full-scale DNRR model with Serpent 2 was also utilized as a reference to verify the PARCS/Serpent *** of the effective neutron multiplication factors,radial and axial core power distributions,and control rod worths showed a generally good agreement between PARCS and Serpent *** addition,the discrepancies between the PARCS and Serpent 2 results are also ***,the results indicate the applicability of the PARCS/Serpent model for further steady state and transient analyses of the DNRR.

关键词： PARCS Serpent 2 Group constant DNRR

Tail spillover effects between cryptocurrencies and uncertainty in the gold,oil,and stock markets

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Financial Innovation 2023年第1期9卷 2339-2365页

作者： Walid Mensi Mariya Gubareva Hee‑Un Ko xuan vinh Vo Sang Hoon Kang Department of Economics and Finance College of Economics and Political ScienceSultan Qaboos UniversityMuscatOman Institute of Business Research University of Economics Ho Chi Minh CityHo Chi Minh CityVietnam Universidade de Lisboa Lisbon School of Economics and Management(ISEG)Research Centre in Economic and Organisational Sociology(SOCIUS)/Research in Social Sciences and Management(CSG)Rua Miguel Lupi 201249‑078 LisbonPortugal Korea Housing and Urban Guarantee Corporation BusanKorea Institute of Business Research and CFVG University of Economics Ho Chi Minh CityHo Chi Minh CityVietnam PNU Business School Pusan National UniversityBusanRepublic of Korea

This study investigates tail dependence among five major cryptocurrencies,namely Bitcoin,Ethereum,Litecoin,Ripple,and Bitcoin Cash,and uncertainties in the gold,oil,and equity *** the cross-quantilogram method and quantile connectedness approach,we identify cross-quantile interdependence between the analyzed *** results show that the spillover between cryptocurrencies and volatility indices for the major traditional markets varies substantially across quantiles,implying that diversification benefits for these assets may differ widely across normal and extreme market *** normal market conditions,the total connectedness index is moderate and falls below the elevated values observed under bearish and bullish market ***,we show that under all market conditions,cryptocurrencies have a leadership influence over the volatility *** results have important policy implications for enhancing financial stability and deliver valuable insights for deploying volatility-based financial instruments that can potentially provide cryptocurrency investors with suitable hedges,as we show that cryptocurrency and volatility markets are insignificantly(weakly)connected under normal(extreme)market conditions.

关键词： Cryptocurrency Uncertainty indices Quantile spillover Crossquantilogram