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Journal of Geoscience and Environment Protection 2022年第8期10卷 309-326页

作者： nguyen Van Hieu nguyen Van Tuan nguyen Khac Bang Pham hoang Hai Le Vinh Ha Tran Thi hoa Institute of Water Resources Planning Ha Noi Vietnam Institute of Environment and Public Health VUSTA Ha Noi Vietnam Thai Binh University Thai Binh Province Thai Binh Vietnam

Probabilistic assessment of drought plays an important role in providing valuable information for evaluating water resources systems under drought conditions, and bivariate copulas are effective and efficient for the probabilistic assessment of drought based on joint distributions and/or joint return periods of drought characteristics. In this study, hydrological drought events and their characteristics (including duration and severity) in the Tien Yen River Basin of Quang Ninh province are detected using the Standardized Streamflow Index (SSFI). The BB8Copula is selected as the best-fit copula for hydrological drought duration and severity. Joint probabilities and joint return periods of drought duration and severity in the cases “and” and “or” are calculated based on the BB8Copula, which are employed for drought assessment. The results show that the drought events with 1-season or cross-quarter duration were more popular than others;joint probabilities and joint return periods of the detected drought events from 1962 to 2009, ranged from 0.2% to 92.2% and from 0.782 years to 315.414 years, respectively, in the case “and”, and ranged from 3.8% to 99.6% and from 0.724 years to 18.785 years, respectively, in the case “or”.

关键词： Probabilistic Assessment Standardized Streamflow Index (SSFI) Hydrological Drought Drought Characteristics Copula

A Multiple Classifier System Using an Adaptive Strategy for Intrusion Detection

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A Multiple Classifier System Using an Adaptive Strategy for ...

Effects of Marxist Methodology on Social Science Researches Conducted by Vietnamese Scholars Before 1986

International Conference on Intelligent Computational Systems(ICICS’2012);International Conference on Mechanical,Automotive and Materials Engineering(ICMAME’2012);International Conference on Electronics,Biomedical Engineering and its Applications(ICEBEA’2012);International Conference on Ecological,Environmental and Biological Sciences(ICEEBS’2012);International Conference on Business,Economics,Management and Behavioral Sciences (ICBEMBS’2012);International Conference on Applied Mathematics and Pharmaceutical Sciences(ICAMPS’2012)

作者： Emna Bahri Nouria Harbi hoa nguyen Huu university of Lyon ERIC Laboratory

Recently, information security has become a key issue in information technology as the number of computer security breaches are exposed to an increasing number of security threats. A variety of intrusion detection systems （IDS） have been employed for protecting computers and networks from malicious network-based or host-based attacks by using traditional statistical methods to new data mining approaches in last decades. In effect, the detection of the anomalies in the data-processing networks is regarded as one problem of data classification where the use of the data mining techniques and machine learning. In this paper, we present a new method performing the intrusion detection system. This approach, called MCSAS, is based on a multiple classifier System that uses an adaptive strategy for intrusion detection. The adaptive strategy is inspired from Boosting, an ensemble method that distinguishes attacks from normal behaviors and identifies different types of intrusions. The experimental results, conducted on the KDD99 dataset, prove that our proposed solution approach outperforms several state-of-the-art methods, particularly indetecting rare attack types.

关键词： Intrusion detection system ensembles methods new multiple classifier KDD99.

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Journal of Literature and Art Studies 2018年第9期8卷 1422-1430页

作者： nguyen Thi Mai hoa(Ruan Shi Mei Hua) Shu Yuan Zhao Marxism School of Hunan University ChangshacityHunanChina Institute of Philosophy Vietnam Academy of Social SciencesHa NoiViet Nam

In the early twentieth century, Marxism was propagated into Vietnam through patriotic intellectuals. After the propagation into Vietnam, Marxism not only influenced national liberation movements, but also profoundly affected scholars, particularly scholars of social science. In fact, many of well-known Vietnamese scholars have relied on Marxism’s theory of social existence and social consciousness, infrastructure and superstructure, practical concept, concept of class struggle, etc. to comment on poetry, history, language, geography, philosophy, etc. In other words, the scholars have applied Marxist methodology to explore and study cultural and social life in Vietnam; and in that way, a generation of Marxist researchers in the field of social sciences has been formed. After the renovation of the country, the Government of Vietnam has implemented its policy of openness and international integration, and scholars have been therefore able to receive many other Western ideals and cultures, and the Marxist methodology was not the only one used in social science research. Consequently, some people expressed their skepticism about the role of Marxist methodology in academic research in Vietnam, even completely denied the historical significance of Marxist methodology to the academia in Vietnam. This article is intended, through Vietnamese Marxist scholars, especially the ones in the field of social sciences prior to 1986 （i.e., prior to the renovation of the country） to demonstrate the historical significance of the Marxist methodology to the Vietnamese academia. It is clear that the penetration of the Marxism and the Marxist methodology into Vietnam have created a revolution in the field of academic research （primarily in the field of social science）. It has promoted academicresearch from conservative toward innovative, from traditional to modern. With the presence of the French colonialism as well as the French culture, the Marxism and the Marxist methodology helped Vie

关键词： Marxist methodology Vietnam scholars social science

Development of Multiphoton Ionization Technique for Detection of Polycyclic Aromatic Hydrocarbon (PAH) in Solution

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Open Journal of Applied Sciences 2015年第10期5卷 595-599页

作者： hoa Do Quang Duong Vu Nghia nguyen Trong Totaro Imasaka Center for Quantum Electronics Institute of Physics Vietnam Academy of Science and Technology (VAST) Hanoi City Vietnam Department of Applied Chemistry Kyushu University Fukuoka Japan

A simple low-cost system for detection of polycyclic aromatic hydrocarbon (PAH) in solution based on multiphoton ionization configuration is designed using a circulating ionization cell of 0.1 × 2 × 5 mm dimension with quartz optical window. Fourth harmonic emission of Nd:YAG laser (266 nm, 6 ns, 10 Hz, and 2 mJ) and second harmonic generation of distributed feedback dye laser (278 - 286 nm, 20 ps, 10 Hz, and 300 μJ) were used as the ionization source. A high voltage of 800 V was applied to separate the ions after ionization. The photocurrent includes a sharp peak and a broad tail indexed to electron and ion currents, respectively. The lowest concentration of anthraxcene (C14H10) in order of few nano-grams per milliliter was detected by this multiphoton ionization configuration.

关键词： UV Laser Multiphoton Ionization Polycyclic Aromatic Hydrocarbon

A Design Configuration of an FPGA-Based Coincident Spectrometry System

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Journal of Analytical Sciences, Methods and Instrumentation 2013年第3期3卷 158-162页

作者： Pham Dinh Khang nguyen Nhi Dien Dang Lanh nguyen Xuan Hai Pham Ngoc Tuan nguyen Duc hoa nguyen An Son Nuclear Research Institute Dalat Vietnam Nuclear Training Center Hanoi Vietnam University of Dalat Dalat Vietnam University of Dalat Dalat Vietnam.

In the past, most of popular coincidence spectrometers were normally based on traditional electronics techniques such as time to amplitude conversion or logic selecting coincidence unit. They were complicated and it is not convenient for us to use them. This paper deals with a new design of a contemporary coincidence spectrometer which is based on Field Programmable Gate Arrays (FPGA) devices via Digital Signal Processing (DSP) techniques with Hardware Description Language (VHDL). The outstanding advantage of DSP techniques and FPGA technology is capable of enhancement of the quality of the experimental measurements for nuclear radiation. The designed configuration of the traditional system was tested on the PCI 7811R board of National Instruments while the digital systems were establishing with FPGA devices. The purpose of this work is referring to the principle for construction of an FPGA-based system capable of replacing a conventional system. Therefore, a novel approach for in-house development of digital techniques is presented. The method for designing the system is utilization of slow-fast coincidence configurations with two HPGe detectors obtaining a pair of coincidence events, processing data in DSP algorithms. The significant and noticeable results are the operating frequency of 80 MHz and system timestamp window of approximately 10 ns.

关键词： Digital Signal Processing FPGA VHDL

Object-Based vs. Pixel-Based Classification of Mangrove Forest Mapping in Vien An Dong Commune, Ngoc Hien District, Ca Mau Province Using VNREDSat-1 Images

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Advances in Remote Sensing 2016年第4期5卷 284-295页

作者： nguyen Thi Quynh Trang Le Quang Toan Tong Thi Huyen Ai nguyen Vu Giang Pham Viet hoa Space Technology Institute Vietnam Academy of Science and Technology Hanoi Vietnam Ho Chi Minh Institute of Resource Geography Vietnam Academy of Science and Technology Ho Chi Minh City Vietnam

Many researches have been performed comparing object-based classification (OBC) and pixel-based classification (PBC), particularly in classifying high-resolution satellite images. VNREDSat-1 is the first optical remote sensing satellite of Vietnam with resolution of 2.5 m (Panchromatic) and 10 m (Multispectral). The objective of this research is to compare two classification approaches using VNREDSat-1 image for mapping mangrove forest in Vien An Dong commune, Ngoc Hien district, Ca Mau province. ISODATA algorithm (in PBC method) and membership function classifier (in OBC method) were chosen to classify the same image. The results show that the overall accuracies of OBC and PBC are 73% and 62.16% respectively, and OBC solved the “salt and pepper” which is the main issue of PBC as well. Therefore, OBC is supposed to be the better approach to classify VNREDSat-1 for mapping mangrove forest in Ngoc Hien commune.

关键词： Object-Based Classification Pixel-Based Classification VNREDSat-1 Mangrove Forest Ca Mau

Fresh and hardened properties of high-performance fiber-reinforced concrete containing fly ash and rice husk ash:Influence of fiber type and content

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Frontiers of Structural and Civil Engineering 2022年第12期16卷 1621-1632页

作者： nguyen-Trong HO Viet Quoc DANG Minh-Hieu nguyen Chao-Lung HWANG Trong-Phuoc HUYNH Faculty of Civil Engineering VSB-Technical University of OstravaOstrava-Poruba 70800Czech Republic Faculty of Bridge and Road Construction Mientrung University of Civil Engineering(MUCE)Tuy Hoa City 56100Vietnam Vinh Long Department of Construction Vinh Long City 85000Vietnam Taiwan Building Technology Center Taiwan University of Science and TechnologyTaipei 10607China Faculty of Civil Engineering College of EngineeringCan Tho UniversityCan Tho City 94000Vietnam

Although fibers are used only infrequently as an additive in concrete in the construction industry,fiberenhanced concrete is known to provide a wide range of advantages over conventional *** main objective of this study was to investigate the influences of fiber type and content on the mechanical properties and durability of highperformance fiber-reinforced concrete(HPFRC)designed using a novel densified mixture design algorithm with fly ash and rice husk *** types of fiber,including polypropylene(PP)fiber,steel fiber(SF),and hybrid fiber(HF),were *** on the results,the inclusion of fibers decreased HPFRC flowability,regardless of fiber *** the compressive strength of HPFRC with 1.6%PP fiber content was 11.2%below that of the reference HPFRC specimen at 91 d of curing age,the 91-d compressive strengths of both SF and HF-enhanced HPFRC specimens were significantly better than that of the reference HPFRC ***,the HPFRC specimens incorporating SF and HF both exhibited better splitting tensile and flexural strengths as well as less drying shrinkage than the HPFRC specimens incorporating PP ***,the fiber-enhanced specimens,especially those with added SF,registered less surface electrical resistivity and greater vulnerability to chloride ion penetration than the reference HPFRC specimen.

关键词： high-performance fiber-reinforced concrete fly ash rice husk ash durability mechanical strength

Spatio-Temporal Analysis of Drought in the North-Eastern Coastal Region of Vietnam Using the Standardized Precipitation Index (SPI)

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Atmospheric and Climate Sciences 2023年第2期13卷 175-200页

作者： nguyen Van Tuan nguyen Van Hieu nguyen Khac Bang Pham hoang Hai nguyen Khanh Van Le Vinh Ha Tran Thi hoa Lê Trọng Hiếu Institute of Water Resources Planning Hanoi Vietnam Institute of Environment and Public Health Vietnam Union of Science and Technology Associations Hanoi Vietnam Thai Binh University Thai Binh Vietnam Faculty of Electronics and Telecommunications Electric Power University Hanoi Vietnam

Spatio-temporal analysis of drought provides valuable information for drought management and damage mitigation. In this study, the Standardized Precipitation Index at the time scale of 6 months (SPI-6) is selected to reflect drought conditions in the North-Eastern coastal region of Vietnam. The drought events and their characteristics from 1981 to 2019 are detected at 9 meteorological stations and 10 Chirps rainfall stations. The spatio-temporal variation of drought in the study region is analyzed on the basis of the number, duration, severity, intensity, and peak of the detected drought events at the 19 stations. The results show that from 1981 to 2019 the drought events mainly occurred with 1-season duration and moderate intensity and peak. The number, duration, severity, and peak of the drought events were the greatest in the period 2001-2010 and were the smallest in the period 2011-2019. Among the 19 stations, the drought duration tends to decrease at 11 stations, increase at 7 stations, and has a slight variant at 1 station;the drought severity tends to decrease at 14 stations, increase at 4 stations, and has not a significant trend at 1 station;the drought intensity tends to decrease at 17 stations, increase at 1 station, and has a slight variant at 1 station;and the drought peak tends to decrease at 18 stations and increase at 1 station.

关键词： Spatio-Temporal Analysis of Drought Standardized Precipitation Index (SPI) Drought Characteristics

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振动研磨过程中研磨参数的定量研究

清华大学学报（自然科学版） 2016年第3期56卷 328-333页

作者：陈恳阮和平吴丹刘飞清华大学机械工程系北京100084 精密超精密制造装备及控制北京市重点实验室北京100084

蛋白质的提取率取决于被提取的生物组织的粉末粒度,因而生物组织的粉碎是蛋白质提取工程中的关键技术之一。目前,生物组织粉碎较多采用振动球磨方式,研磨产品粒度和研磨效率与研磨过程的特征参量如碰撞频率、碰撞能量有密切关系。为了... 详细信息

蛋白质的提取率取决于被提取的生物组织的粉末粒度,因而生物组织的粉碎是蛋白质提取工程中的关键技术之一。目前,生物组织粉碎较多采用振动球磨方式,研磨产品粒度和研磨效率与研磨过程的特征参量如碰撞频率、碰撞能量有密切关系。为了研究研磨参数对研磨特征参量的影响规律,该文采用事件驱动法(event driven method,EDM)建立了振动球磨机构中单个磨球在研磨罐内的动力学模型,获得了振动频率、振动幅度和研磨罐直径对碰撞频率和碰撞能量的影响规律。结果表明:碰撞频率、碰撞能量均随着振动频率和振动幅度增大而增大;在相同的磨腔体积即研磨罐容积下,随着研磨罐直径的增大碰撞频率和碰撞能量减小。该结论为研磨机构设计和参数选择提供理论依据和方法。

关键词：振动球磨事件驱动法研磨参数碰撞频率碰撞能量

A comparative analysis of weight-based machine learning methods for landslide susceptibility mapping in Ha Giang area

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Big Earth Data 2023年第4期7卷 1005-1034页

作者： Thanh Trinh Binh Thanh Luu Trang Ha Thi Le Duong Huy nguyen Trong Van Tran Thi Hai Van nguyen Khanh Quoc nguyen Lien Thi nguyen Faculty of Computer Science Phenikaa UniversityYen NghiaHa DongHanoi 12116Vietnam Phenikaa Research and Technology Institute(PRATI) A&A Green Phoenix Group JSCNo.167 Hoang NganTrung HoaCau GiayHanoi 11313Vietnam Northwestern Geological Division General Department of Geology and Minerals of VietnamHanoiVietnam Youth union office Thuyloi University175 Tay SonDong DaHanoiVietnam Center of Remote Sensing and Geohazards Vietnam Institute of Geosciences and Mineral ResourcesHanoiVietnam

Landslide susceptibility maps (LSMs) are very crucial for planningpolicies in hazardous areas. However, the accuracy and reliability ofLSMs depend on available data and the selection of suitable *** study is conducted to produce LSMs by combinations of machinelearning methods and weighting techniques for Ha Giang province,Vietnam, where has limited data. In study area, we gather 11 landslideconditioning factors and establish a landslide inventory *** the weights of classes (or factors) is very important toprepare data for machine learning methods to generate LSMs. Wefrst use frequency ratio (FR) and analytic hierarchy process (AHP)techniques to generate the weights. Then, random forest (RF), supportvector machine (SVM), logistic regression (LR), and AHP methods arecombined with FR and AHP weights to yield accurate and reliableLSMs. Finally, the performance of these methods is evaluated by fivestatistical metrics, ROC and R-index. The empirical results have shownthat RF is the best method in terms of R-index and the five metrics, *** rate (0.9661), FP rate (0.0), ACC (0.9835), MAE (0.0046), and RMSE(0.0350) for this study area. This study opens the perspective of weightbasedmachine learning methods for landslide susceptibility mapping.

关键词： Landslide logistic regression random forest SvM Vietnam