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Deep learning long short-term memory combined with discrete element method for porosity prediction in gravel-bed rivers

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International Journal of Sediment Research 2023年第1期38卷 128-140页

作者： duong Tran Anh Ahad Hasan Tanim Daniel Prakash Kushwaha Quoc Bao Pham van Hieu Bui HUTECH University Center for River Harbor and Landslide Research Chittagong University of Engineering & Technology Govind Ballabh Pant University of Agriculture and Technology Institute of Applied Technology Thu Dau Mot University Faculty of Mechanical Engineering Thuyloi University

The porosity of gravel riverbed material often is an essential parameter to estimate the sediment transport rate, groundwater-river flow interaction, river ecosystem, and fluvial geomorphology. Current methods of porosity estimation are time-consuming in simulation. To evaluate the relation between porosity and grain size distribution(GSD), this study proposed a hybrid model of deep learning Long Short-Term Memory(LSTM) combined with the Discrete Element Method(DEM). The DEM is applied to model the packing pattern of gravel-bed structure and fine sediment infiltration processes in threedimensional(3D) space. The combined approaches for porosity calculation enable the porosity to be determined through real time images, fast labeling to be applied, and validation to be done. DEM outputs based on the porosity dataset were utilized to develop the deep learning LSTM model for predicting bed porosity based on the GSD. The simulation results validated with the experimental data then segregated into 800 cross sections along the vertical direction of gravel pack. Two DEM packing cases, i.e., clogging and penetration are tested to predict the porosity. The LSTM model performance measures for porosity estimation along the z-direction are the coefficient of determination(R~2), root mean squared error(RMSE), and mean absolute error(MAE) with values of 0.99, 0.01, and 0.01 respectively, which is better than the values obtained for the Clogging case which are 0.71, 0.14, and 0.03, respectively. The use of the LSTM in combination with the DEM model yields satisfactory results in a less complex gravel pack DEM setup, suggesting that it could be a viable alternative to minimize the simulation time and provide a robust tool for gravel riverbed porosity prediction. The simulated results showed that the hybrid model of the LSTM combined with the DEM is reliable and accurate in porosity prediction in gravel-bed river test samples.

关键词： Numerical modeling Discrete element method LSTM Bed porosity Gravel-bed river

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A new species of the genus leptolalax (Anura： Megophryidae) from southern Vietnam

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Zoological Research 2018年第3期39卷 185-201页

作者： Tang van duong Dang Trong Do Chung Dac Ngo Truong Quang Nguyen Nikolay A. Poyarkov Vietnam National Museum of Nature Vietnam Academy of Science and Technology Hanoi Vietnam Department of Vertebrate Zoology Biological FacultyLomonosov Moscow State University Moscow 119234 Russia Faculty of Natural Sciences Phu Yen University Tuy Hoa Phu Yen Vietnam College of Education Hue University Hue Vietnam Institute of Ecology and Biological Resources Vietnam Academy of Science and Technology Hanoi Vietnam Graduate University of Science and Technology Vietnam Academy of Science and Technology Cau Giay Hanoi Vietnam Joint Russian- Vietnamese Tropical Research and Technological Center Nghia Do Cau Giay Hanoi Vietnam

We describe a new species of megophryid frog from Phu Yen Province in southern Vietnam. leptolalax macrops sp. nov. is distinguished from its congeners by a combination of the following morphological attributes：（1） body size medium （SVL 28.0-29.3 mm in three adult males, 30.3 mm in single adult female）; （2） supra-axillary glands present, creamy white; ventrolateral glands indistinct; （3） tympanum externally distinct; （4） dorsal skin roughly granular with larger tubercles, dermal ridges on dorsum absent; （5） rudimentary webbing present between fingers I-II and I1-111; rudimentary webbing between all toes; fingers and toes without dermal fringes; （6） in life ventral surface greyish-violet with white speckling; （7） supratympanic fold distinct, dark brown in life; （8） iris bicolored, typically golden in upper half, fading to golden green in lower half; （9） tibia short （TbL/SVL 0.44-0.45 in males）; and （10） eyes large and protuberant （ED/SVL 0.15-0.16 in males） From all congeners for which comparable sequences are available, the new species differs markedly in the 16S rRNA mitochondrial gene sequence （P-distance〉5.7%）. The new species is currently known only from montane evergreen tropical forests of Song Hinh District, Phu Yen Province, and M＇Drak District of Dak Lak Province at elevations of 470-630 m a.s.l.. We suggest the new species should be considered as Data Deficient following the IUCN＇s Red List categories. We also report a previously unknownleptolalax mtDNA lineage from an evergreen tropica forest in the Hoa Thinh District of Phu Yen Province which may also represent an undescribed species.

关键词： leptolalax macrops sp. nov. Phu YenProvince Dak Lak Province Southern coastal regionof Vietnam

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Schistosomal appendicitis:A serious and often misdiagnosed condition

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World Journal of Clinical Cases 2025年第10期13卷 62-64页

作者： Phi duong Nguyen Thanh Kien Lam Orthopaedic-Burn-Plastic Surgery City Children’s HospitalHo Chi Minh City 71815Viet Nam The Faculty of Medical Technology Van Lang UniversityHo Chi Minh City 700000Viet Nam

Schistosomal appendicitis(SA)is a rare but serious complication of schistosomiasis,a parasitic disease affecting over 250 million people worldwide.A recent retrospective study by Wang et al provides important insights into the clinicopathological characteristics of *** study compared 136 cases of SA to 5418 cases of non-SA over a ten-year *** findings include a higher average age of SA patients(61.73 years vs 35.8 years for non-SA),a higher proportion of acute on chronic appendicitis(33.1%vs 16%),and a significantly higher incidence of colorectal cancer(11.7%vs 2.2%).Despite these differences,SA remains a diagnostic challenge due to its nonspecific clinical presentation and lack of specific laboratory *** study also highlights the persistent prevalence of SA,accounting for 1.6%-3.4%of all appendicitis cases each year from 2013 to *** findings underscore the need for enhanced awareness,early detection,and prompt treatment of SA in endemic *** the association with colorectal cancer,patients with SA require thorough screening and *** research into the pathogenesis and diagnostic markers of SA is *** the global battle against schistosomiasis continues,targeted efforts to diagnose and manage SA can significantly improve patient outcomes.

关键词： Schistosomal appendicitis Schistosomiasis Colorectal cancer Misdiagnosis Clinicopathological characteristics

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Tuning the inhomogeneous charge transport in ZnO interfaces for ultrahigh on/off ratio top-gated field-effect-transistor arrays

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Nano Research 2020年第11期13卷 3033-3040页

作者： Thanh Luan Phan Dinh Loc duong Tuan Khanh Chau Sidi Fan Won Tae Kang Thi Suong le Hyun Yong Song Linfeng Sun van Tu Vu Min Ji lee Quoc An Vu Young Hee lee Woo Jong Yu Department of Electrical and Computer Engineering Sungkyunkwan UniversitySuwon16419Republic of Korea Center for Integrated Nanostructure Physics(CINAP) Institute for Basic Science(IBS)Suwon16419Republic of Korea Department of Energy Science Sungkyunkwan UniversitySuwon16419Republic of Korea Department of Physics Sungkyunkwan UniversitySuwon16419Republic of Korea

The interface between oxide/oxide layers shows an inhomogeneous charge transport behavior,which reveals a high conductivity owing to *** typical example is the hetero-interface between ZnO film and other wide band gap oxides(e.g.,Al_(2)O_(3),TiO_(2),and HfO_(2)).It is thus quite evident that the ZnO/other oxides hetero-interface contains high density electron carriers effectively screening the gate-induced electric ***,an extremely weak gate modulation in ZnO film was showed,resulting in very low on/off ratio of 1.69 in top-gate field-effect-transistor(TG-FET)***,to extend the usage of ZnO TG-FET is not quite possible toward further practical ***,we clarified the correlation of inhomogeneous region in oxide/oxide hetero-junction by systematically *** work suggests that a self-assembly of molecules(SAM)buffer layer is suitable for tuning the inhomogeneous charge transport in ZnO film,which not only reduces the interface trap density,but also effectively enhances the gate electric field modulation at the *** further report the robust fabrication of TG-FET arrays based on ZnO thin film,using an ultra-thin alkylphosphonic acid molecule monolayer as buffer *** device demonstrates a pronounced ultrahigh on/off ratio of≥10^(8),which is 8-order of magnitude higher than that of a device without buffer *** the highly reliable arrays,our device exhibits a high yield of over 93%with an average on/off ratio of^10^(7) across the entire wafer scale,mobility(18.5 cm^(2)/(V·s)),an extended bias-stressing(~2,000 s)and long-stability(~150 days)under ambient conditions.

关键词： zinc oxides thin-film field-effect-transistor self-assembly molecule inhomogeneous charge transport interface engineering

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Adaptive Nonlinear PD Controller of Two-Wheeled Self-Balancing Robot with External Force

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Computers, Materials & Continua 2024年第11期81卷 2337-2356页

作者： van-Truong Nguyen Dai-Nhan duong Dinh-Hieu Phan Thanh-Lam Bui Xiem Hoangvan Phan Xuan Tan Faculty of Mechatronics SMAEHanoi University of IndustryHanoi159999Vietnam Faculty of Electronics and Telecommunications Vietnam National University-University of Engineering and Technology(VNU-UET)Hanoi10000Vietnam College of Engineering Shibaura Institute of TechnologyTokyo135-8548Japan

This paper proposes an adaptive nonlinear proportional-derivative(ANPD)controller for a two-wheeled self-balancing robot(TWSB)modeled by the Lagrange equation with external *** proposed control scheme is designed based on the combination of a nonlinear proportional-derivative(NPD)controller and a genetic algorithm,in which the proportional-derivative(PD)parameters are updated online based on the tracking error and the preset error *** addition,the genetic algorithm is employed to adaptively select initial controller parameters,contributing to system stability and improved control *** proposed controller is basic in design yet simple to *** ANPD controller has the advantage of being computationally lightweight and providing high robustness against external *** stability of the closed-loop system is rigorously analyzed and verified using Lyapunov theory,providing theoretical assurance of its *** and experimental results show that the TWSB robot with the proposed ANPD controller achieves quick balance and tracks target values with very small errors,demonstrating the effectiveness and performance of the proposed *** proposed ANPD controller demonstrates significant improvements in balancing and tracking performance for two-wheeled self-balancing robots,which has great applicability in the field of robot control *** represents a promising solution for applications requiring precise and stable motion control under varying external conditions.

关键词： Two-wheeled self-balancing robot nonlinear PD control external force genetic algorithm

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Three New Anamorph of <i>Ceramothyrium</i>from Fallen leaves in Vietnam

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Advances in Microbiology 2018年第4期8卷 314-323页

作者： le Thi Hoang Yen Yasuhisa Tsurumi duong van Hop Katsuhiko Ando Institute of Microbiology and Biotechnology Vietnam National University Ha Noi Vietnam National Institute of Technology and Evaluation Kisarazu Japan

Three new anamorph of Ceramothyrium aquaticum sp. nov., Ceramothyrium exiguum sp. nov., and Ceramothyrium phuquocense sp. nov. are described and illustrated. These fungi were isolated from submerged decaying leaves collected from Phu Quoc National Park, Phu Quoc province, Viet Nam. The phylogeny based on ITS region and D1/D2 of the 28S rDNA gene showed that these fungi nested in the Ceramothyrium. Morphologically, C. aquaticum, C. phuquocense sp. nov. and C. exiguum sp. nov. are characterized;they were different from known anamorph species of Ceramothyrium by having one main axis and two lateral arms with 70 - 90, 33.5 - 72.5 and 70 - 130 μm long main axis, respectively. The table to compare Ceramothyrium anamorph is also given.

关键词： Aquatic Fungi Annamorph Telemorph Litter Fungi

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A new genus and three new species of miniaturized microhylid frogs from Indochina(Amphibia: Anura:Microhylidae: Asterophryinae)

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Zoological Research 2018年第3期39卷 130-157页

作者： Nikolay A.Poyarkov Chatmongkon Suwannapoom Parinya Pawangkhanant Akrachai Aksornneam Tang van duong Dmitriy V.Korost Jing Che Department of Vertebrate Zoology Biological Faculty Lomonosov Moscow State University Joint Russian-Vietnamese Tropical Research and Technological Center 3. Division of Fishery School of Agriculture and Natural Resources University of Phayao 4. Department of Zoology Faculty of Science Kasetsart University Vietnam National Museum of Nature Vietnam Academy of Science and Technology Petroleum Geology Department Geological Faculty Lomonosov Moscow State University 7. State Key Laboratory of Genetic Resources and Evolution Kunming Institute of Zoology Chinese Academy of Sciences Southeast Asia Biodiversity Research Institute Chinese Academy of Sciences

We report on the discovery of a new genus of microhylid subfamily Asterophryinae from northern and eastern Indochina, containing three new *** Gen. nov. are secretive miniaturized frogs(SVLle. To assess phylogenetic relationships, we studied 12 S rRNA – 16 S rRNA mt DNA fragments with a final alignment of 2 591 bp for 53 microhylid species. Morphological and osteological characters were analyzed using micro-CT scanning and used to describe the new genus. Results of phylogenetic analyses assigned the new genus into the mainly Australasian subfamily Asterophryinae as a sister taxon to the genus Siamophryne from southern Indochina. The three specimens collected from Gia Lai Province in central Vietnam, Cao Bang Province in northern Vietnam, and Chiang Rai Province in northern Thailand proved to be separate species, different both in morphology and genetics(genetic divergence 3.1%≤P≤5.1%). Our work provides further evidence for the "out of Indo-Eurasia"scenario for Asterophryinae, indicating that the initial cladogenesis and differentiation of this group of frogs occurred in the Indochina Peninsula. To date, each of the three new species of Vietnamophryne Gen. nov. is known only from a single specimen; thus,their distribution, life history, and conservation status require further study.

关键词： Vietnamophryne Gen. nov. Vietnamophryne inexpectata sp. nov. Vietnamophryne orlovi sp. nov. Vietnamophryne occidentalis sp. nov. Siamophryne Gastrophrynoides mtDNA micro-CT scanning Vietnam Thailand Herpetofauna Amphibia Biogeography Taxonomy Indochina

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Prolonged post-thaw culture of embryos does not improve outcomes of frozen human embryo transfer cycles: A prospective randomized study

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Asian pacific Journal of Reproduction 2019年第6期8卷 260-266页

作者： Minh Tam le van Trung Nguyen Thanh Tung Nguyen MBlake Evans Thai Thanh Thi Nguyen Tam AnThi Nguyen Dinh duong le Vu Quoc Huy Nguyen Ngoc Thanh Cao Micah J.Hill Department of Obstetrics and Gynecology Hue University of Medicine and PharmacyHue University06 Ngo Quyen StreetHueVietnam Center for Reproductive Endocrinology and Infertility Hue University of Medicine and PharmacyHue University06 Ngo Quyen StreetHueVietnam Department of Histology and Embryology Hue University of Medicine and PharmacyHue University06 Ngo Quyen StreetHueVietnam Walter Reed National Military Medical Center 8901 Rockville PikeBethesdaMD20889USA Department of Public Health Hue University of Medicine and PharmacyHue University06 Ngo Quyen StreetHueVietnam

Objective:To evaluate the impact of prolonged post-thaw embryos culture on pregnancy outcome during frozen embryo transfer ***:This prospective cohort study evaluated 324 thaw transfer cycles with 819 embryos from 269 patients at the Center for Reproductive Endocrinology and Infertility of Hue University Hospital in *** frozen embryo transfer cycles were divided into two groups at the time of thawing:the short culture group(2-hour post-thaw culture)and the overnight culture group(overnight culture for 18 h)before the embryo was transferred into the *** rates of embryo intact,grade A embryo at frozen and transfer time and continuing cleavage were *** clinical outcomes including serum beta-human chorionic gonadotropin,clinical pregnancy and implantation rate were evaluated after 14 days,4 weeks,6 weeks,respectively,after embryo ***:Human chorionic gonadotropin positive occurred in 39.5%of patients in the short culture group compared to 25.9%in the overnight culture group with risk difference(RD)=13.6%,relative risk(RR)=1.343,95%confidence interval(CI)1.085-1.663,Pvanced age(≥35 years)and women who received 3 embryos,pregnancy outcomes were found to be significantly(P<0.05)higher in the short culture than in the overnight culture ***:The prolonged post-thaw culture period does not increase pregnancy outcome in comparison with the short culture.

关键词： Embryo vitrification Post-thaw culture Frozen embryo transfer Biochemical pregnancy rate Clinical pregnancy rate Implantation rate

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A time-domain estimation method of rapidly time-varying channels for OFDM-based LTE-R systems

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Digital Communications and Networks 2019年第2期5卷 94-101页

作者： Jin-Kyu Choi van Due Nguyen Hai Nam Nguyen van Vinh duong Tien Hoa Nguyen Hanbyeog Cho Hyun-Kyun Choi Seong-Gyoon Park Smart Mobility Research Department of ETR1 DaejeonSouth Korea School of Electronics and Telecommunicalions HUSTViet Nam Electronics and Telecommunications Research Institute DaejeonSouth Korea School of Information and Communication in KongJu National University South Korea

This paper addresses the performance of fast doubly selective fading channel estimation combined with InterCarrier Interference (ICI) cancellation for Long Term Evolution (LTE) communication platform in the High Speed Railway (HSR) environment. We consider the Channel Impulse Response (CIR) coefficients with a critical Doppler frequency shift and multi-path fading that were taken from the WINNER II channel model and the D2a propagation scenario, where the conditions of HSR are analyzed. As multi-path fading increases and the channel varies in the order of the symbol period, we first propose a novel approach for designing a pilot symbol structure in the time domain. Then, we describe the deployment of the proposed pilot symbol structure to estimate the channel in the time domain. Channel information corresponding to the data positions is obtained by linear interpolation. In each OFDM symbol, the slope and the initial value for establishing an interpolation function are estimated to adapt to the time variation of the channel. An accurate estimate of channel state information is used for the purpose of ICI cancellation. The simulation results show that the channel estimated by our proposed method can follow the real channel well, even in a very high Doppler frequency. The estimation method in terms of Mean Squared Error (MSE) significantly outperforms the state-of-the-art methods. The combination of our channel estimator with several interference cancelers provides a considerably better system performance than that achieved when frequency channel estimation is used.

关键词： ICI cancellation OFDM Channel estimation LTE-R

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Ordered SnO nanoparticles in MWCNT as a functional host material for high-rate lithium-sulfur battery cathode

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Nano Research 2017年第6期10卷 2083-2095页

作者： A-Young Kim Min Kyu Kim Ji Young Kim Yuren Wen Lin Gu van-duong Dao Ho-Suk Choi Dongjin Byun Joong Kee lee Center for Energy Convergence Korea Institute of Science and Technology Seoul02792 Republic of Korea Department of Material Science and Engineering Korea University Seoul 02841 Republic of Korea Beijing National Laboratory for Condensed Matter Physics Institute of Physics Chinese Academy of Sciences Beijing 100190 China Department of Chemical Engineering & Applied Chemistry Chungnam National University Daejeon 34134 Republic of Korea

Lithium-sulfur battery has become one of the most promising candidates for next generation batteries, and it is still restricted due to the low sulfur conductivity, large volume expansion and severe polysulfide shuttling. Herein, we present a novel hybrid electrode with a ternary nanomaterial based on sulfur-impregnated multiwalled carbon nanotubes filled with ordered tin-monoxide nanoparticles （MWCNT-SnO/S）. Using a dry plasma reduction method, a mechanically robust material is prepared as a cathode host material for lithium-sulfur batteries. The MWCNT-SnO/S electrode exhibits high conductivity, good ability to capture polysulfides, and small volume change during a repeated charge-discharge process. In situ transmission electron microscopy and ultraviolet-visible absorption results indicate that the MWCNT-SnO host efficiently suppresses volume expansion during lithiation and reduces polysulfide dissolution into the electrolyte. Furthermore, the ordered SnO nanoparticles in the MWCNTs facilitate fast ion/electron transfer during the redox reactions by acting as connective links between the walls of the MWCNTs. The MWCNT-SnO/S cathode with a high sulfur content of 70 wt.% exhibits an initial discharge capacity of 1,682.4 mAh·g^-1 at 167.5 m·g^-1 （0.1 C rate） and retains a capacity of 530.1 mAh·g^-1 at 0.5 C after 1,000 cycles with nearly 100% Coulombic efficiency. Furthermore, the electrode exhibits the high capacity even at a high current rate of 20 C.

关键词： hybrid nanomaterial multiwalled carbonnanotube (MWCNT) ordered tin monoxide cathode high loading lithium-sulfur battery

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