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基于PSS/ADEPT的越南宁桥区配电网网损分析及降损方案

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基于PSS/ADEPT的越南宁桥区配电网网损分析及降损方案

作者： do van dung（杜文勇）北京交通大学

学位级别：硕士

电能从发电厂经电力网传输到电力用户,需经过电力线路、电力变压器等设备,而这些设备会带来大量的电能损耗。电力网络的损耗主要包括电网线路损耗和变压器损耗。系统线损过高会降低电网的供电经济效益和可靠性。因此研究并采取措施降低... 详细信息

电能从发电厂经电力网传输到电力用户,需经过电力线路、电力变压器等设备,而这些设备会带来大量的电能损耗。电力网络的损耗主要包括电网线路损耗和变压器损耗。系统线损过高会降低电网的供电经济效益和可靠性。因此研究并采取措施降低配电网的网损,对提高配电网可靠性、稳定性与经济性起着十分重要的作用。本文根据越南目前的电网运行模式和配电网状况,基于电力网络降损原理和PSS/ADEPT仿真,研究越南宁桥区配电网减少电能损耗的方案。本论文研究配电网络降损相关技术,具体完成如下工作:第一,查阅相关文献资料,研究配电网损耗的主要组成部分及原因、网损现状和越南电网损耗现状。对当前配电网运行损耗的现状有一个总体的了解,为下一步研究降损方案奠定基础。第二,分析了配电网功率损耗的基本原理及计算方法,同时对配电网目前的运行状况及其降损技术措施进行了较为深入的研究。第三,在完成理论研究后,根据现有的资料数据对越南芹苴市宁桥区22kV配电网网络结构和运行方式进行深入分析和研究,为搭建仿真模型奠定基础。学习PSS/ADEPT软件进行配电网网损计算的基本方法,深入了解软件中设备模型的参数和状态,将其应用于配网降损的计算和分析。第四,针对越南芹苴市宁桥区22kV配电网进行PSS/ADEPT建模和仿真,对区内8条主输电线路最优无功补偿位置和容量进行定量计算,提出具体的减少电能损耗的最佳方案。

关键词：电力系统配电网网损电网降损无功补偿

Velocity equation for grenades while impacting on dry sand media

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Defence Technology（防务技术） 2024年第5期35卷 168-173页

作者： Martin Macko Xuan Son Bui Kongsathit Phanthavong Duc Hung Pham van Gion do van Minh do Jiri Skala University of Defence BrnoCzech Republic Le Quy don Technical University Ha NoiViet Nam

This paper deals with the collision of sphere shape grenades with sand *** central issue of the article is the establishing of an empirical velocity equation of the grenade while impacting on sand that is used to solve motion equations of the mechanical mechanism inside the impact grenade *** paper focuses on impact velocities that are lower than 5 m s^(-1).An experiment was conducted to study the velocity of the grenade while impacting on dry sand.A high-speed camera video was used to capture the grenade *** grenade velocity in the impact process was generated from these video *** types of fitting curves are used to regress the velocity equation of the grenade while interacting with the sand media and the best-fitting model is *** result shows the regression curve has a high correlation with the experiment data for grenade velocities below 5 m s^(-1).The received regression equation is useful for analyzing the working ability of the inertial mechanism inside the impact grenade or analyzing and choosing the appropriate parameters of each part in the inertial mechanism to meet the required characteristics of the mechanism.

关键词： Dynamic response Impact velocity Impact grenade Low-velocity impact

Study on the tunnel shape and soil-lining interaction influencing the lining behavior under seismic loading

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Earthquake Engineering and Engineering Vibration 2024年第4期23卷 845-862页

作者： van Vi Pham Ngoc Anh do Piotr Osinski Ngoc Thai do Daniel Dias Sustainable Development in Underground Engineering Research Team Hanoi University of Mining and GeologyHanoiVietnam Department of Underground and Mining Construction Faculty of Civil EngineeringHanoi University of Mining and GeologyHanoiVietnam Department of Geotechnical Engineering Institute of Civil EngineeringWarsaw University of Life Sciences-SGGWWarszawaPoland Laboratory 3SR Grenoble Alpes UniversityGrenoble 38400France

The response of tunnels subjected to seismic loading is a complex mechanism and depends not only on the seismic nature but also on tunnel structure and surrounding soil *** individual behavior of circular,rectangular,and sub-rectangular tunnels subjected to seismic loadings has already been studied in the *** the present research,two case scenarios of circular,rectangular tunnels and four sub-rectangular shaped tunnels,with similar cross-section areas,were adopted to perform a comprehensive numerical *** purpose of the study was to determine the mechanical behavior of tunnels of different shapes,depending upon seismic *** were performed by considering the influence of soil-lining interaction,soil parameters,and lining thickness,as well as lining *** were performed for no-slip and full-slip *** results indicate that the tunnel shape design is of great importance when regarding the mechanical behavior of the surrounding *** concerns no-slip as well as full-slip soil-lining interaction,especially when the lining is subjected to seismic ***,it is shown that changes in incremental bending moments for circular,rectangular and sub-rectangular tunnels that depend upon the soil-lining interaction conditions differ significantly.

关键词： tunnel shape soil-lining interaction seismic loading internal forces numerical analysis

A New Framework for Software Vulnerability Detection Based on an Advanced Computing

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Computers, Materials & Continua 2024年第6期79卷 3699-3723页

作者： Bui van Cong Cho do Xuan Department of Information Technology University of Economics and Technical IndustriesHanoi100000Vietnam Faculty of Information Security Posts and Telecommunications Institute of TechnologyHanoi100000Vietnam

The detection of software vulnerabilities written in C and C++languages takes a lot of attention and interest *** paper proposes a new framework called DrCSE to improve software vulnerability *** uses an intelligent computation technique based on the combination of two methods:Rebalancing data and representation learning to analyze and evaluate the code property graph(CPG)of the source code for detecting abnormal behavior of software *** do that,DrCSE performs a combination of 3 main processing techniques:(i)building the source code feature profiles,(ii)rebalancing data,and(iii)contrastive *** which,the method(i)extracts the source code’s features based on the vertices and edges of the *** method of rebalancing data has the function of supporting the training process by balancing the experimental ***,contrastive learning techniques learn the important features of the source code by finding and pulling similar ones together while pushing the outliers *** experiment part of this paper demonstrates the superiority of the DrCSE Framework for detecting source code security vulnerabilities using the Verum *** a result,the method proposed in the article has brought a pretty good performance in all metrics,especially the Precision and Recall scores of 39.35%and 69.07%,respectively,proving the efficiency of the DrCSE *** performs better than other approaches,with a 5%boost in Precision and a 5%boost in ***,this is considered the best research result for the software vulnerability detection problem using the Verum dataset according to our survey to date.

关键词： Source code vulnerability source code vulnerability detection code property graph feature profile contrastive learning data rebalancing

循环三轴试验加载频率和压实度对重塑砂土液化行为的影响

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岩土力学 2024年第6期45卷 1813-1823页

作者： THUY do van TIEP Pham Duc HIEU Nguyen van THANG Pham Cao 勒奎东技术大学特殊工程技术研究所越南河内越南航空科技协会越南河内

通过对各向同性固结不排水试样进行循环三轴试验,研究了饱和重塑砂土的液化行为。试验采用恒幅正弦载荷,通过测量剪切模量、阻尼比、轴向应变和超孔隙水压力比的变化,评估了加载频率(分别为0.1、0.5、1.0 Hz)和压实度(分别为0.95、0.90... 详细信息

通过对各向同性固结不排水试样进行循环三轴试验,研究了饱和重塑砂土的液化行为。试验采用恒幅正弦载荷,通过测量剪切模量、阻尼比、轴向应变和超孔隙水压力比的变化,评估了加载频率(分别为0.1、0.5、1.0 Hz)和压实度(分别为0.95、0.90和0.80)对砂土液化行为的影响。试验结果表明,对于压实度为0.95的砂样,在5000次加载循环中,0.1 Hz的加载频率对液化过程影响甚微;而对于压实度为0.90和0.80的砂样,此频率的影响显著。对于压实度为0.80的砂样,当频率增加到0.5 Hz时几乎一加载就直接发生液化。这表明增加加载频率会加快液化速度,而增加压实度则会减慢液化速度。因此,通过一系列的试验可以模拟现场砂土在不同频率下的动荷载条件。试验结果表明,饱和砂土的液化行为由以下因素决定:(1)试样的压实度越低,液化越容易发生;(2)加载频率越高,液化越容易发生;(3)循环轴向应变越大,发生液化所需的循环次数越少;(4)超孔隙水压力随加载循环次数增加,直至试样完全液化。

关键词：液化行为加载频率循环三轴试验饱和固结不排水条件重塑砂土压实度

Sn nucleation and growth from Sn(II)dissolved in ethylene glycol:Electrochemical behavior and temperature effect

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Transactions of Nonferrous Metals Society of China 2024年第8期34卷 2714-2732页

作者： Kiem van do Hieu van NGUYEN Tu Manh LE Faculty of Electrical and Electronic Engineering Phenikaa UniversityYen NghiaHa-DongHanoi 10000Vietnam Phenikaa Research and Technology Institute(PRATI) A&A Green Phoenix Group167 Hoang NganHanoi 10000Vietnam Faculty of Materials Science and Engineering Phenikaa Institute for Advanced Study(PIAS)Phenikaa UniversityHanoi 10000Vietnam

Thermodynamic and kinetic aspects of Sn nucleation and growth processes onto a glassy carbon electrode from SnCl2·2H2O dissolved in ethylene glycol solutions were *** reduction and oxidation peaks observed in voltammograms have demonstrated the capability of ethylene glycol solutions to electrodeposit *** temperature-dependence of diffusion coefficient values derived from potentiodynamic and potentiostatic studies helped to determine and validate estimations of the activation energy for Sn(II)bulk *** results have identified that,the suitable model to describe the early stage of Sn electrodeposition could be composed of Sn three-dimensional nucleation and diffusion-controlled growth and water reduction contributions,which was duly validated by theoretical and experimental *** the model,typical kinetic parameters such as the nucleation frequency of Sn(A),number density of Sn nuclei(N_(0)),and diffusion coefficient of Sn(II)ions(D),were *** presence of Sn nuclei with excellent quality and their structures were verified using SEM,EDX,and XRD techniques.

关键词： Sn nucleation growth ethylene glycol nucleation kinetics electrodeposition

Effectiveness and safety of electroacupuncture analgesia in controlling intraoperative pain and hemodynamics during total thyroidectomy:A randomized controlled trial

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Journal of Traditional Chinese Medical Sciences 2024年第2期11卷 165-171页

作者： dong Phuong Tran Quoc dung Nguyen Ninh Khac Nguyen van Hong Pham Senior Specialist Clinic National Hospital of AcupunctureHanoi10000Vietnam Vietnam National Association of Acupuncture Hanoi10000Vietnam Department of Training and Science National Hospital of AcupunctureHanoi10000Vietnam

Objective:To evaluate the effectiveness and safety of electroacupuncture in conjunction with additional medications in providing analgesia and stabilizing hemodynamic parameters during total ***:This randomized controlled trial included 100 patients who underwent a total thyroidectomy between October 2022 and October 2023 at the Vietnam National Hospital of *** patients were randomized into two *** electroacupuncture analgesia(EA)group received EA stimulation at five acupuncture points:Hegu(LI 4),Neiguan(PC 6),Shuitu(ST 10),Quepen(ST 12),and Yifeng(SJ 17),while the control group received a bilateral superficial cervical plexus *** outcomes included the level of analgesia and perioperative vital signs in both ***,pain thresholds and serum b-endorphin levels were measured before and after electroacupuncture in the EA ***:Complete analgesia(Level A)was attained in 86%and 76%of the patients in the EA and control groups,respectively,with no significant difference between the two groups(P¼1.00).In the EA group,the mean pain threshold after receiving EA doubled(648.7(77.4)g/s vs.305.3(45.3)g/s,Pdorphin level increased by approximately 13.5 pg/mL(P<.001).All patients remained hemodynamically stable throughout the ***:EA,in conjunction with additional medications that stimulate five acupuncture points,LI 4,PC 6,ST 10,ST 12,and SJ 17,was well tolerated and effectively maintained a suitable level of analgesia and hemodynamic stability during total thyroidectomy.

关键词： Electroacupuncture Acupuncture analgesia Graves'disease Thyroidectomy Thyroid surgery b-Endorphin

Nonlocal isogeometric analysis for bidirectional functionally graded porous curved microbeams with arbitrary boundary conditions

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Acta Mechanica Sinica 2024年第8期40卷 194-218页

作者： Thu-Huong Nguyen Thi van Ke Tran van-Minh Phung van Hai Trinh Quoc Hoa Pham Faculty of Mechanical Engineering Hanoi University of IndustryHanoi100000Vietnam Faculty of Mechanical Engineering Le Quy Don Technical UniversityHanoi100000Vietnam Institute of Vehicle and Energy Engineering Le Quy Don Technical UniversityHanoi100000Vietnam Faculty of Engineering and Technology Nguyen Tat Thanh UniversityHo Chi Minh City700000Vietnam

This research aims to analyze the static bending and free vibration behaviors of bidirectional functionally graded porous(BFGP)curved microbeams with elastic boundary conditions resting on a Pasternak’s elastic foundation in a hygro-thermal *** analysis based on non-uniform rational B-splines,first-order shear deformation theory,nonlocal elasticity theory combined with the modified strain gradient theories,modified Timoshenko beam theory are formulated to depict bending and shear deformations of BFGP curved ***,because using the modified Timoshenko beam theory,this study removes the requirement for a shear correction factor and describes shear stress by zero at the upper and lower cross-sectional sites of the BFGP curved *** from traditional boundary conditions,where the beginning and end positions of a curved beam are connected by an elastic system of straight and torsion *** allows for greater flexibility in controlling the stiffness of the springs to obtain arbitrary *** assess the accuracy and convergence of the proposed approach,validation numerical examples were conducted in the various examples.

关键词： Bidirectional functionally graded porous material Elastic boundary condition Isogeometric analysis Curved microbeams Nonlocal elasticity theory Modified strain gradient theory

Mapping and understanding degradation of alpine wetlands in the northern Maloti-Drakensberg, southern Africa

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Journal of Mountain Science 2024年第9期21卷 2956-2966页

作者： Johan van TOL Department of Soil Crop and Climate SciencesUniversity of the Free StateBloemfontein 9300South Africa

The alpine terrestrials of the Maloti-Drakensberg in southern Africa play crucial roles in ecosystem functions and livelihoods,yet they face escalating degradation from various factors including overgrazing and climate *** study employs advanced Digital Soil Mapping(DSM)techniques coupled with remote sensing to map and assess wetland coverage and degradation in the northern *** model achieved high accuracies of 96%and 92%for training and validation data,respectively,with Kappa statistics of 0.91 and 0.83,marking a pioneering automated attempt at wetland mapping in this *** attributes such as terrain wetness index(TWI)and valley depth(VD)exhibit significant positive correlations with wetland coverage and erosion gully density,Channel Network Depth and slope were negative *** density analysis revealed terrain attributes as dominant factors driving degradation,highlighting the need to consider catchment-specific susceptibility to *** challenge traditional assumptions which mainly attribute wetland degradation to external forces such as livestock overgrazing,ice rate activity and climate *** sensitivity map produced could serve as a basis for Integrated Catchment Management(ICM)projects,facilitating tailored conservation *** research should expand on this work to include other highland areas,explore additional covariates,and categorize wetlands based on hydroperiod and sensitivity to *** comprehensive study underscores the potential of DSM and remote sensing in accurately assessing and managing wetland ecosystems,crucial for sustainable resource management in alpine regions.

关键词： Digital Soil Mapping Gully density Integrated catchment management Remote sensing Wetland degradation