检索结果-南通市图书馆

The Continuous Knapsack Problem with Capacities

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 the Operations Research Society of China 2021年第3期9卷 713-721页

作者： Huynh Duc quoc nguyen Chi Tam Tran Hoai Ngoc Nhan Department of Mathematics College of Natural ScienceCan Tho UniversityCan Tho City 900900Vietnam Faculty of Basic Sciences Vinh Long University of Technology EducationVinh Long 940000Vietnam

We address a variant of the continuous knapsack problem,where capacities regarding costs of items are given into *** prove that the problem is NP-complete although the classical continuous knapsack problem is solvable in linear *** the case that there exists exactly one capacity for all items,we solve the corresponding problem in O(n log n)time,where n is the number of items.

关键词： Knapsack problem Complexity Capacity Polynomially solvabl

Building 3D CityGML models of mining industrial structures using integrated UAV and TLS point clouds

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

International Journal of Coal Science & Technology 2023年第5期10卷 158-177页

作者： Canh Le Van Cuong Xuan Cao Anh Ngoc nguyen Chung Van Pham Long quoc nguyen Department of Mine Surveying Hanoi University of Mining and GeologyHanoiVietnam Viettel Group Viettel Cyberspace CenterHanoiVietnam

Mining industrial areas with anthropogenic engineering structures are one of the most distinctive features of the real world.3D models of the real world have been increasingly popular with numerous applications,such as digital twins and smart factory *** this study,3D models of mining engineering structures were built based on the CityGML *** collecting spatial data,the two most popular geospatial technologies,namely UAV-SfM and TLS were *** accuracy of the UAV survey was at the centimeter level,and it satisfied the absolute positional accuracy requirement of creat-ing all levels of detail(LoD)according to the CityGML ***,the UAV-SfM point cloud dataset was used to build LoD 2 *** addition,the comparison between the UAV-SfM and TLS sub-clouds of facades and roofs indicates that the UAV-SfM and TLS point clouds of these objects are highly consistent,therefore,point clouds with a higher level of detail and accuracy provided by the integration of UAV-SfM and TLS were used to build LoD 3 *** resulting 3D CityGML models include 39 buildings at LoD 2,and two mine shafts with hoistrooms,headframes,and sheave wheels at LoD3.

关键词： 3D modelling CityGML-Mining industry UAV Terrestrial laser scanning Point cloud

Heterogeneous decentralised machine unlearning with seed model distillation

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

CAAI Transactions on Intelligence Technology 2024年第3期9卷 608-619页

作者： Guanhua Ye Tong Chen quoc Viet Hung nguyen Hongzhi Yin School of Information Technology and Electrical Engineering The University of QueenslandSt LuciaQueenslandAustralia School of Information and Communication Technology Griffith UniversityBrisbaneQueenslandAustralia

As some recent information security legislation endowed users with unconditional rights to be forgotten by any trained machine learning model,personalised IoT service pro-viders have to put unlearning functionality into their *** most straight-forward method to unlearn users'contribution is to retrain the model from the initial state,which is not realistic in high throughput applications with frequent unlearning *** some machine unlearning frameworks have been proposed to speed up the retraining process,they fail to match decentralised learning scenarios.A decentralised unlearning framework called heterogeneous decentralised unlearning framework with seed(HDUS)is designed,which uses distilled seed models to construct erasable en-sembles for all ***,the framework is compatible with heterogeneous on-device models,representing stronger scalability in real-world *** experiments on three real-world datasets show that our HDUS achieves state-of-the-art performance.

关键词： data mining data privacy machine learning

A systematic rheological study of alkyl amine surfactants for fluid mobility control in hydrocarbon reservoirs

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Petroleum Science 2018年第3期15卷 538-551页

作者： Madalyn M. Liebum George Hirasaki quoc P. nguyen Petroleum and Geosystems Engineering Department The University of Texas at Austin 200 E.Dean Keeton St.Stop C0300 Room CPE 5.104 A Austin TX 78712 USA Highlands Ranch CO 80129 USA

The basis of this study is to identify the versatility of N,N,N＇-trimethyl-N＇-tallow-1,3-diaminopropane（DTTM） surfactant in high saline environments. The surfactant was examined with sodium chloride, NaCl, to understand how triggers such as salt, p H, temperature, and surfactant concentration influences the viscoelastic response of the surfactant solution. The DTTM surfactant and salt（NaCl） concentrations used in steady-state shear viscosity analysis range from 0.2 wt% to 2 wt%and 5 wt% to 25 wt%, respectively. Along with DTTM results, three similar chemical structures are investigated to understand how viscosity changes with alterations in tail and head group composition. It was found that DTTM surfactant has the capability of transitioning from a foam-bearing to viscoelastic state at low surfactant concentrations under moderate to high saline conditions. A longer tail length promotes viscoelasticity and shear-thinning behavior. Terminals consisting of hydroxides or ethoxylates have a lower viscosity than that of methyl terminals. A head group consisting of two nitrogen atoms has a higher viscosity than those containing one nitrogen atom. The rheological characterization of DTTM presented in this paper is part of a larger study in determining the capability of this surfactant to foam CO2 for improving mobility control in CO2 enhanced oil recovery in high saline oil formations.

关键词： Rheology Surfactants Wormlike micelles Viscoelastic Amines

Verification of Beam Models for Ionic Polymer-Metal Composite Actuator

在线全文

学校读者我要写书评

暂无评论

Journal of Bionic Engineering 2009年第3期6卷 232-238页

作者： Hoon Cheol Park quoc Viet nguyen Jang Woo Lee Young Tai Yoo Artificial Muscle Research Center Konkuk University Department of Advanced Technology Fusion Konkuk University Department of Materials Chemistry and Engineering Konkuk University

Ionic Polymer-Metal Composite (IPMC) can work as an actuator by applying a few voltages.A thick IPMC actuator,where Nafion-117 membrane was synthesized with polypyrrole/alumina composite filler,was analyzed to verify the equivalent beam and equivalent bimorph beam *** blocking force and tip displacement of the IPMC actuator were measured with a DC power supply and Young's modulus of the IPMC strip was measured by bending and tensile tests *** calculated maximum tip displacement and the Young's modulus by the equivalent beam model were almost identical to the corresponding measured *** element analysis with thermal analogy technique was utilized in the equivalent bimorph beam model to numerically reproduce the force-displacement relationship of the IPMC *** results by the equivalent bimorph beam model agreed well with the force-displacement relationship acquired by the measured *** is confirmed that the equivalent beam and equivalent bimorph beam models are practically and effectively suitable for predicting the tip displacement,blocking force and Young's modulus of IPMC actuators with different thickness and different composite of ionic polymer membrane.

关键词： jonic polymer-metal composite beam model displacement force

Minimizing Warpage for Macro-Size Fused Deposition Modeling Parts

在线全文

学校读者我要写书评

暂无评论

Computers, Materials & Continua 2021年第9期68卷 2913-2923页

作者： Thanh Thuong Huynh Tien V.T.nguyen quoc Manh nguyen Trieu Khoa nguyen Department of Mechanical Engineering Can Tho UniversityCampus IICan ThoVietnam Faculty of Mechanical Technology Industrial University of Ho Chi Minh CityHo Chi Minh70000Vietnam Mechanical Engineering Department National Kaohsiung University of Science and TechnologyKaohsiung80778Taiwan Faculty of Mechanical Engineering Hung Yen University of Technology and EducationHung Yen16000Vietnam

In this study,we investigated warpage and corner lifting minimization for three-dimensional printed parts generated by macro-size fused deposition modeling(FDM).First,the reasons for warpage were theoretically *** approach revealed that the thermal deformation and differential volumetric shrinkage of the extruded molten plastic resulted in warpage of FDM *** addition,low adhesion between the deposited model and the heated or non-heated printing bed may intensify warpage *** a next step,initial small-size and medium-size models were used to identify parameters to manage and minimize warpage in a way that would reduce material consumption and running ***,a macro-size model was built to experimentally investigate and verify the technical solutions to minimize the warpage of FDM *** conclusion,an improved part with reduced warpage was efficiently produced after detailed consideration of thermal effects and adhesion *** exists to widen the application scope of FDM technology in manufacturing for processes like thermoforming that involve mold core fabrication with *** technology,which has applications not only in mechanical engineering but also in related engineering fields,is convenient and could readily be applied to practical manufacturing industries.

关键词： Fused deposition modeling corner lifting volumetric shrinkage thermal deformation acrylonitrile butadiene styrene filament

Current scenario and challenges of plastic pollution in Bangladesh:a focus on farmlands and terrestrial ecosystems

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Frontiers of Environmental Science & Engineering 2023年第6期17卷 1-22页

作者： MdRaihanul Islam Sumaiya Akter Ruponti MdAbdur Rakib Huy quoc nguyen Monjur Mourshed Faculty of Agriculture Bangabandhu Sheikh Mujibur Rahman Agricultural UniversityGazipur 1706Bangladesh Department of Microbiology Faculty of Biological Science and TechnologyJashore University of Science of TechnologyJashore 7408Bangladesh Faculty of Heat and Refrigeration Engineering The University of Danang—University of Science and TechnologyDanang 550000Vietnam Mechanical and Automotive Engineering School of EngineeringRMIT UniversityBundooraVictoria 3083Australia Department of Mechanical Engineering Rajshahi University of Engineering and Technology(RUET)Rajshahi 6204Bangladesh

Plastic is considered one of the most indispensable commodities in our daily *** the end of life,the huge ever-growing pile of plastic waste(PW)causes serious concerns for our environment,including agricultural farmlands,groundwater quality,marine and land ecosystems,food toxicity and human health *** of proper infrastructure,financial backup,and technological advancement turn this hazardous waste plastic management into a serious threat to developing countries,especially for Bangladesh.A comprehensive review of PW generation and its consequences on environment in both global and Bangladesh contexts is *** dispersion routes of PW from different sources in different forms(microplastic,macroplastic,nanoplastic)and its adverse effect on agriculture,marine life and terrestrial ecosystems are illustrated in this *** key challenges to mitigate PW pollution and tackle down the climate change issue is discussed in this ***,way forward toward the design and implementation of proper PW management strategies are highlighted in this study.

关键词： Plastic waste Farmlands Terrestrial ecosystem Marine life

Insights and implications from the study on meniscus reconstruction using tendon autograft

在线全文

学校读者我要写书评

暂无评论

World Journal of Orthopedics 2024年第11期15卷 1109-1111页

作者： phi Duong nguyen Thanh Kien Lam Department of 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

This letter addresses the recent study by Zhu et al on the predictive factors for coronal and sagittal graft extrusion length following medial meniscus reconstruction using tendon *** study provides valuable insights into the importance of preoperative joint space width and tunnel positioning as predictors of graft ***,it found strong correlations between preoperative joint space width and medial,posterior,and mean graft extrusion at both 1 week and 8 months ***,tunnel edge distance at 1 week postoperation correlated with anterior and posterior graft *** findings offer critical guidance for improving surgical ***,the letter highlights the need for further research with larger sample sizes and comparative studies involving different graft types to strengthen these findings and broaden their applicability in clinical *** study's contributions to understanding meniscus reconstruction using tendon autografts are acknowledged,along with suggestions for future research directions.

关键词： Meniscus reconstruction Tendon autograft Graft extrusion Joint space width Tunnel positioning Surgical outcomes

Effectiveness of bee venom acupuncture for patients suffering from periarthritis humeroscapularis

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 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(P<0.01),only the BV3 group showed significant increase of anti-inflammatory(IL-10)and decrease of pro-inflammatory(IL-1β,TNF-α)cytokines after treatment(P<0.05).The BV3 group presented a significant difference between all outcomes compared to the control and other ***:BV3 groups showed better recovery including reduced pain,improved motor function and normalized inflammatory cytokines than 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