检索结果-南通市图书馆

Journal of Environmental Science and Engineering(A) 2016年第11期5卷 570-573页

作者： Vu Ngoc Pi nguyen khac tuan Thai nguyen University of Technology Thai Nguyen 23000 Vietnam

This paper presents a new study on optimum calculation of partial ratios of three-step helical gearboxes. The chosen objective function is the cross section dimension of the gearbox. In solving the optimization problem, the design equation for pitting resistance of a gear set was investigated and equations on moment equilibrium condition of a mechanic system including three gear units and their regular resistance condition are analyses. From the results of the study, effective formula for determination of the partial ratios of three-step helical gearboxes is introduced. As the formulas are explicit, the partial ratios can be calculated accurately and simply.

关键词： Gearbox design optimum design helical gearbox transmission ratio.

Optimum Determination of Partial Transmission Ratios of Mechanical Driven Systems Using a V-belt and a Helical Gearbox with Second-Step Double Gear-Sets

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Environmental Science and Engineering(A) 2017年第7期6卷 377-380页

作者： nguyen khac tuan Vu Ngoc Pi Automotive and Power Machinery Faculty Thai Nguyen University of Technology Thai Nguyen 23000 Vietnam Mechanical Engineering Faculty Thai Nguyen University of Technology Thai Nguyen 23000 Vietnam

This paper presents a study on the optimum determination of partial transmission ratios of a mechanical drive system using a V-belt and a helical gearbox with second-step double gear-sets in order to get the minimum size of the system. The chosen objective function was the cross section dimension of the system. In the optimization problem, the design equation for pitting resistance of a gear set was investigated and equations on moment equilibrium condition of a mechanic system including a V-belt and a helical gearbox with second-step double gear-sets and their regular resistance condition were analysed. Based on the results of the study, effective formulas for calculation of the partial ratios of the V-belt and a helical gearbox with second-step double gear-sets were proposed. By using explicit models, the partial ratios can be determined accurately and simply.

关键词： Transmission ratio gearbox design optimum design V-belt drive helical gearbox.

Optimum Determination of Partial Transmission Ratios of Mechanical Driven Systems Using a V-belt and a Three-Step Helical Gearbox

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Environmental Science and Engineering(B) 2017年第6期6卷 328-331页

作者： Dang Anh tuan nguyen khac tuan Vu Ngoc Pi Mechanical Engineering Faculty Thai Nguyen University of Technology Thai Nguyen 23000 Vietnam Automotive and Power Machinery Faculty Thai Nguyen University of Technology Thai Nguyen 23000 Vietnam

This paper introduces a new study on the optimum calculation of partial transmission ratios of a mechanical drive system using a V-belt and a three-step helical gearbox in order to get the minimum size of the system. The chosen objective function was the cross section dimension of the system. In solving the optimization problem, the design equation for pitting resistance of a gear set was investigated and equations on moment equilibrium condition of a mechanic system including a V-belt and three helical gear units and their regular resistance condition were analysed. From the results of the study, effective formulas for determination of the partial ratios of the V-belt and three-step helical gearboxes were introduced. As using explicit models, the partial ratios can be determined accurately and simply.

关键词： Transmission ratio gearbox design optimum design V-belt drive helical gearbox.

Optimum Calculation of Partial Transmission Ratios of Mechanical Driven Systems Using a V-belt and a Two-Step Bevel Helical Gearbox

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Environmental Science and Engineering(A) 2016年第11期5卷 566-569页

作者： Vu Ngoc Pi nguyen Thi Hong Cam nguyen khac tuan Mechanical Engineering Faculty Thai Nguyen University of Technology Thai Nguyen 23000 Vietnam Automotive and Power Machinery Faculty Thai Nguyen University of Technology Thai Nguyen 23000 Vietnam

This paper introduces a new study on the optimum calculation of partial transmission ratios of mechanical drive system using a V-belt and two-step bevel helical gearbox for getting minimum size of the system. In the paper, based on moment equilibrium condition of a mechanic system including V-belt and a two-gear-unit of the gearbox, models for optimum calculation of the partial ratios of the V-belt and the gearbox were proposed. As the models are explicit, the partial ratios can be calculated accurately and simply.

关键词： Transmission ratio gearbox design optimum design helical gearbox.

Truly optimal semi-active damping to control free vibration of a single degree of freedom system

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Theoretical & Applied Mechanics Letters 2024年第2期14卷 142-145页

作者： Viet Duc La Ngoc tuan nguyen Institute of Mechanics Vietnam Academy of Science and TechnologyHanoi 10000Vietnam Graduate University of Science and Technology Vietnam Academy of Science and TechnologyHanoi 10000Vietnam

This paper studies a single degree of freedom system under free vibration and controlled by a general semiactive damping.A general integral of squared error is considered as the performance index.A one-time switching damping controller is proposed and *** pontryagin maximum principle is used to prove that no other form of semi-active damping can provide the better performance than the proposed one-time switching damping.

关键词： Analytical optimization Quadratic integral Lyapunov equation Pontryagin maximum principle

Photocatalytic degradation of antibiotic sulfamethizole by visible light activated perovskite LaZnO_(3)

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2024年第10期144卷 212-224页

作者： Bui The Huy XCuong nguyen Vu khac Hoang Bui nguyen Ngoc Tri Iqra Rabani Nhu Hoa Thi Tran Quang Viet Ly Hai Bang Truong Major of Biomedical Engineering Division of Smart HealthcareCollege of Information Technology and ConvergencePukyong National UniversityBusan 48513Korea Center for Advanced Chemistry Institute of Research and DevelopmentDuy Tan UniversityDa Nang 550000Viet Nam Faculty of Environmental and Chemical Engineering Duy Tan UniversityDa Nang 550000Viet Nam Department of Environment and Energy Sejong UniversitySeoul 05006Korea Lab of Computational Chemistry and Modelling Department of ChemistryFaculty of Natural SciencesQuy Nhon UniversityQuy NhonViet Nam Department of Nanotechnology and Advanced Materials Engineering Sejong UniversitySeoul 05006Korea Faculty of Materials Science and Technology University of ScienceHo Chi Minh City 700000Viet Nam Vietnam National University Ho Chi Minh City 700000Viet Nam Department of Environmental Engineering Seoul National University of Science and TechnologySeoul 01811Korea Optical Materials Research Group Science and Technology Advanced InstituteVan Lang UniversityHo Chi Minh CityViet Nam Faculty of Applied Technology School of TechnologyVan Lang UniversityHo Chi Minh CityViet Nam

In thiswork,the perovskite LaZnO_(3) was synthesized via sol-gel method and applied for photocatalytic treatment of sulfamethizole(SMZ)antibiotics under visible light *** was almost completely degraded(99.2%±0.3%)within 4 hr by photocatalyst LaZnO3 at the optimal dosage of 1.1 g/L,with amineralization proportion of 58.7%±0.4%.The efficient performance of LaZnO_(3) can be attributed to itswide-range light absorption and the appropriate energy band edge levels,which facilitate the formation of active agents such as·O_(2)^(−),h^(+),and·*** integration of RP-HPLC/Q-TOF-MS and DFT-based computational techniques revealed three degradation pathways of SMZ,which were initiated by the deamination reaction at the aniline ring,the breakdown of the sulfonamidemoieties,and a process known as Smile-type rearrangement and SO2 *** toxicity of SMZ and the intermediateswere analyzed by quantitative structure activity relationship(QSAR),indicating the effectiveness of LaZnO_(3)-based photocatalysis in preventing secondary pollution of the intermediates to the ecosystem during the degradation *** visible-light-activated photocatalyst LaZnO_(3) exhibited efficient performance in the occurrence of inorganic anions and maintained high durability across multiple recycling tests,making it a promising candidate for practical antibiotic treatment.

关键词： Perovskite Antibiotics Photocatalysis Density functional theory Toxicity

Unknown DDoS Attack Detection with Fuzzy C-Means Clustering and Spatial Location Constraint Prototype Loss

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Computers, Materials & Continua 2024年第2期78卷 2181-2205页

作者： Thanh-Lam nguyen HaoKao Thanh-tuan nguyen Mong-Fong Horng Chin-Shiuh Shieh Department of Electronic Engineering National Kaohsiung University of Science and TechnologyKaohsiung807618Taiwan Department of Electronic and Automation Engineering Nha Trang UniversityNha Trang650000Vietnam

Since its inception,the Internet has been rapidly *** the advancement of science and technology and the explosive growth of the population,the demand for the Internet has been on the *** applications in education,healthcare,entertainment,science,and more are being increasingly deployed based on the ***,malicious threats on the internet are on the rise as *** Denial of Service(DDoS)attacks are among the most common and dangerous threats on the internet *** scale and complexity of DDoS attacks are constantly *** Detection Systems(IDS)have been deployed and have demonstrated their effectiveness in defense against those *** addition,the research of Machine Learning(ML)and Deep Learning(DL)in IDS has gained effective results and significant ***,one of the challenges when applying ML and DL techniques in intrusion detection is the identification of unknown *** attacks,which are not encountered during the system’s training,can lead to misclassification with significant *** this research,we focused on addressing the issue of Unknown Attack Detection,combining two methods:Spatial Location Constraint Prototype Loss(SLCPL)and Fuzzy C-Means(FCM).With the proposed method,we achieved promising results compared to traditional *** proposed method demonstrates a very high accuracy of up to 99.8%with a low false positive rate for known attacks on the Intrusion Detection Evaluation Dataset(CICIDS2017)***,the accuracy is also very high,reaching 99.7%,and the precision goes up to 99.9%for unknown DDoS attacks on the DDoS Evaluation Dataset(CICDDoS2019)*** success of the proposed method is due to the combination of SLCPL,an advanced Open-Set Recognition(OSR)technique,and FCM,a traditional yet highly applicable clustering *** has yielded a novel method in the field of unknown attack *** further expands the trend of applying DL and M

关键词： Cybersecurity DDoS unknown attack detection machine learning deep learning incremental learning convolutional neural networks(CNN) open-set recognition(OSR) spatial location constraint prototype loss fuzzy c-means CICIDS2017 CICDDoS2019

Reviewing Stability Criteria for Positive Homogeneous Systems and Adding One for Discrete-Time Cases with Degree Less Than One

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Circuits and Systems 2024年第1期15卷 1-11页

作者： nguyen Quang tuan Faculty of Information Technology Nha Trang University Khanh Hoa Vietnam

The article synthesizes and presents the results regarding the stability of positive homogeneous systems that have been researched and published in recent years. Next, we provide a sufficient condition for global exponential stability in the case of discrete-time positive homogeneous systems with an order less than one with time-varying delays.

关键词： Exponential Stability Homogeneous Systems Positive Systems Positive Homogeneous Systems

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

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

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,P<.001),and the mean serum b-endorphin 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

EP Aquarii:A New Picture of the Circumstellar Envelope

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Research in Astronomy and Astrophysics 2024年第3期24卷 83-105页

作者： Pham T.Nhung Do T.Hoai Pierre Darriulat Pham tuan-Anh Pham N.Diep nguyen B.Ngoc Tran T.Thai Department of Astrophysics Vietnam National Space CenterVietnam Academy of Science and Technology18Hoang Quoc VietNghia DoCau GiayHa Noivietnam

New analyses of earlier ALMA observations of oxygen-rich AGB star EP Aquarii are presented,which complete a previously published analysis and offer a different interpretation of the morpho-kinematics of the circumstellar *** birth of the equatorial density enhancement(EDE)is shown to occur very close to the star where evidence for rotation has been *** to the star and where outflows have been observed:their interaction with the gas of the nascent EDE is seen to play an important role in the development of the wind and the evolution of its radial velocity from 8 to 10 km s^(-1) on the polar symmetry axis to~2 km s^(-1) at the *** implies complex morpho-kinematics:making reliable interpretations with reasonable confidence is *** particular,it questions an earlier interpretation implying the presence of a white dwarf companion orbiting the star at an angular distance of -0″4 from its *** proposes instead an interpretation in terms of a standard mass ejection associated with a shock wave leaving a void of emission in its *** Doppler velocity wings are seen to consist of two components,the upper velocity end of the global wind,reaching above±12 km s^(-1),and an effective line broadening,confined within 200 mas from the center of the star,reaching above±20 km s^(-1) and interpreted as caused by the pattern of shock waves resulting from the interaction between stellar pulsation and convective cell partition.

关键词： stars AGB and post-AGB-(stars) circumstellar matter-radio lines stars