检索结果-南通市图书馆

Determination of Helmert transformation parameters for continuous GNSS networks:a case study of the Géoazur GNSS network

引用

Geo-Spatial Information Science 2023年第1期26卷 125-138页

作者： dinh Trong Tran Jean-Mathieu Nocquet Ngoc Dung Luong dinh Huy nguyen Department of Geodesy and Geomatics Engineering Hanoi University of Civil EngineeringHanoiVietnam UniversitéCôte d’Azur CNRSObservatoire de la Côte d’AzurIRDValbonneFrance

In this paper,we propose an approach to determine seven parameters of the Helmert transfor-mation by transforming the coordinates of a continuous GNSS network from the World Geodetic System 1984(WGS84)to the International Terrestrial Reference *** includes(1)convert-ing the coordinates of common points from the global coordinate system to the local coordinate system,(2)identifying and eliminating outliers by the Dikin estimator,and(3)estimating seven parameters of the Helmert transformation by least squares(LS)estimation with the“clean”data(*** removed).Herein,the local coordinate system provides a platform to separate points’horizontal and vertical ***,the Dikin estimator identifies and eliminates outliers in the horizontal or vertical component *** is significant because common points in a continuous GNSS network may contain *** proposed approach is tested with the Géoazur GNSS network with the results showing that the Dikin estimator detects outliers at 6 out of 18 common points,among which three points are found with outliers in the vertical compo-nent ***,instead of eliminating all coordinate components of these six common points,we only eliminate all coordinate components of three common points and only the vertical component of another three common ***,the classical LS estimation is applied to“clean”data to estimate seven parameters of the Helmert transformation with a significant accuracy *** Dikin estimator’s results are compared to those of other robust estimators of Huber and Theil-Sen,which shows that the Dikin estimator performs ***,the weighted total least-squares estimation is implemented to assess the accuracy of the LS estimation with the same *** inter-comparison of the seven estimated parameters and their standard deviations shows a small difference at a few per million levels(E-6).

关键词： Continuous GNSS tectonic geodesy Dikin estimation Helmert transformation

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

An analytical model for cross-Kerr nonlinearity in a four-level N-type atomic system with Doppler broadening

引用

Chinese Physics B 2022年第2期31卷 314-319页

作者： dinh Xuan Khoa nguyen Huy Bang nguyen Le Thuy An nguyen Van Phu Le Van Doai Vinh University 182 Le Duan StreetVinh CityVietna

We present an analytical model for cross-Kerr nonlinear coefficient in a four-level N-type atomic medium under Doppler *** model is applied to87 Rb atoms to analyze the dependence of the cross-Kerr nonlinear coefficient on the external light field and the temperature of atomic *** analysis shows that in the absence of electromagnetically induced transparency(EIT)the cross-Kerr nonlinear coefficient is zero,but it is significantly enhanced when the EIT is *** means that the cross-Kerr effect can be turned on/off when the external light field is on or ***,the amplitude and the sign of the cross-Kerr nonlinear coefficient are easily changed according to the intensity and frequency of the external light *** amplitude of the cross-Kerr nonlinear coefficient remarkably decreases when the temperature of atomic medium *** analytical model can be convenient to fit experimental observations and applied to photonic devices.

关键词： electromagnetically induced transparency Kerr nonlinear effect Doppler effect

来源：

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

Thermal Performance Prediction in the Air Gap of a Rotor-Stator Configuration: Effects of Numerical Models

引用

Journal of Thermal Science 2020年第1期29卷 206-218页

作者： DANG dinh-Dong PHAM Xuan-Tan nguyen Chi-Cong Department of Mechanical Engineering École de technologie supérieureMontrealQCCanada Hydro-Québec’s research institute VarennesQCCanada

This study is dedicated to a numerical investigation of convective heat transfer on the rotor surfaces of a rotor-stator configuration that is typically found in large *** computational fluid dynamics calculations with two turbulence modelling approaches are used to predict the flow structure and heat transfer in the air gap of the rotor-stator *** steady state mixing plane approach is employed at the interface to couple the rotor and stator *** show that the location of mixing plane interface in the air gap plays an important role in the prediction of heat transfer on the pole ***,it is indicated that the prediction of temperature distribution on the pole face is greatly affected by the turbulence models ***,through a comparison between the pure convective and conjugate heat transfer methodologies,it is shown that the inclusion of solid domain into the numerical model significantly improves the thermal prediction of the solid components of the machine.

关键词： hydro-generators electrical cooling mixing plane windage loss conjugate heat transfer

来源：

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

Power analysis,sample size calculation for testing the largest binomial probability

引用

Statistical Theory and Related Fields 2020年第1期4卷 78-83页

作者： thuan nguyen Jiming Jiang Oregon Health and Science University PortlandORUSA University of California DavisCAUSA

A procedure is developed for power analysis and sample size calculation for a class of complex testing problems regarding the largest binomial probability under a combination of *** is shown that the asymptotic null distribution of the likelihood-ratio statistic is not parameterfree,but χ_(1)^(2) is a conservative asymptotic null distribution.A nonlinear Gauss-Seidel algorithm is proposed to uniquely determine the alternative for the power and sample size calculation given the baseline binomial *** example from an animal clinical trial is discussed.

关键词： Asymptotic null distribution binomial probability complex hypotheses Gauss-Seidel logistic regression power sample size tests

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Regularization of the Inverse Problem for Time Fractional Pseudo-parabolic Equation with Non-local in Time Conditions

引用

Acta Mathematica Sinica,English Series 2022年第12期38卷 2199-2219页

作者： nguyen Duc PHUONG Le dinh LONG Anh Tuan nguyen Dumitru BALEANU Faculty of Fundamental Science Industrial University of Ho Chi Minh CityVietnam Division of Applied Mathematics Science and Technology Advanced InstituteVanLang UniversityHoChi Minh CityVietnam Faculty of Technology Van Lang UniversityHo Chi Minh CityVietnam Department of Mathematics Cankaya UniversityAnkaraTurkey Lebanese AmericanUniversity BeirutLebanon Institute of Space Sciences Magurele-BucharestRomania

This paper is devoted to identifying an unknown source for a time-fractional diffusion equation in a general bounded ***,we prove the problem is non-well posed and the stability of the source ***,by using the Modified Fractional Landweber method,we present regularization solutions and show the convergence rate between regularization solutions and sought solution are given under a priori and a posteriori choice rules of the regularization parameter,***,we present an illustrative numerical example to test the results of our theory.

关键词： Source problem fractional pseudo-parabolic problem ill-posed problem convergence estimates regularization

来源：

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

Long-Term Improvement in Precautions for Flood Risk Mitigation:A Case Study in the Low-Lying Area of Central Vietnam

引用

International Journal of Disaster Risk Science 2021年第2期12卷 250-266页

作者： Cong dinh nguyen Funiikazu Ubukata Quang Tan nguyen Hoang Ha Vo Graduate School of Environmental and Life Science Okayama UniversityOkayama 700-8530Japan Faculty of Economics and Development Studies University of EconomicsHue UniversityHue City 49000Vietnam International School Hue UniversityHue City 49000Vietnam

Local actors appear as inseparable components of the integrated flood risk mitigation strategy in *** this fact,this study examined the long-term improvement in precautions taken by commune authorities and households between two major floods in 1999 and 2017 by applying both quantitative and qualitative *** flood-prone villages were selected for a survey;one in a rural area and the other in a suburban area of Thua Thien Hue Province,central *** findings indicate that most villagers doubted the structural works’efficacy and were dissatisfied with the current efforts of local ***’self-preparation thus became the decisive factor in mitigating *** most households have paid greater attention to flood precautions in 2017,others seem to be ***-related barriers were the root causes restraining households in both rural and suburban *** suburban riverine residents were further identified as vulnerable by their limitations in upgrading structural measures,which was ascribed to the inconsistency in the ancient town’s preservation *** multidimensional comparison,in terms of vulnerability,emphasized the importance of space-function links in the suburb and the contradictions of different policy initiatives,such as landscape rehabilitation,disaster prevention,and livelihood maintenance.

关键词： Central Vietnam Flood risk mitigation Long-term improvement Natural hazards Precautionary measures

来源：

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

A discussion of prior-based Bayesian information criterion (PBIC)

引用

Statistical Theory and Related Fields 2019年第1期3卷 17-18页

作者： Jiming Jiang thuan nguyen Department of Statistics University of CaliforniaDavisDavisCAUSA Department of Public Health and Preventive Medicine Oregon Health and Science UniversityPortlandORUSA

Professor Bayarri and coauthors’ paper (hereafter,PBIC) offers a stimulating and welcomed addition tothe already extensive and yet still rapid expanding literature on model selection and related topics. In a 2013review on model selection in linear mixed models byMüller, Scealy, and Welsh (2013), the authors classified main approaches in mixed model selection intothree categories, the information criteria, the shrinkagemethods and the fence methods. The current paper isnot specifically regarding mixed model selection problems;however, as one shall see, there is a connection invarious ways.

关键词： methods. criterion hereafter

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Ambient BackCom in beyond 5G NOMA networks: A multi-cell resource allocation framework

引用

Digital Communications and Networks 2022年第6期8卷 1005-1013页

作者： Wali Ullah Khan Fida Hussain Memon Kapal Dev Muhammad Awais Javed dinh-thuan Do Nawab Muhammad Faseeh Qureshi Interdisciplinary Centre for Security Reliability and Trust(SnT)University of Luxembourg1855 Luxembourg CityLuxembourg Department of Electrical Engineering Sukkur IBA University Pakistan Department of Institute of Intelligent Systems University of JohannesburgSouth Africa Department of Electrical and Computer Engineering COMSATS University Islamabad44000IslamabadPakistan Electrical Engineering Department University of Colorado DenverDenverCO80204USA Department of Computer Education Sungkyunkwan UniversitySeoulSouth Korea

The research of Non-Orthogonal Multiple Access (NOMA) is extensively used to improve the capacity of networks beyond the fifth-generation. The recent merger of NOMA with ambient Backscatter Communication (BackCom), though opening new possibilities for massive connectivity, poses several challenges in dense wireless networks. One such challenge is the performance degradation of ambient BackCom in multi-cell NOMA networks under the effect of inter-cell interference. Driven by providing an efficient solution to the issue, this article proposes a new resource allocation framework that uses a duality theory approach. Specifically, the sum rate of the multi-cell network with backscatter tags and NOMA user equipment is maximized by formulating a joint optimization problem. To find the efficient base station transmit power and backscatter reflection coefficient in each cell, the original problem is first divided into two subproblems, and then the closed form solution is derived. A comparison with the Orthogonal Multiple Access (OMA) ambient BackCom and pure NOMA transmission has been provided. Simulation results of the proposed NOMA ambient BackCom indicate a significant improvement over the OMA ambient BackCom and pure NOMA in terms of sum-rate gains.

关键词： Beyond fifth-generation Non-orthogonal multiple access Ambient BackCom Spectrum efficiency optimization

来源：

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

Effect of three tree species on UV weathering of wood flour-HDPE composites

引用

Journal of Forestry Research 2020年第3期31卷 1071-1079页

作者： Van dinh nguyen Tat Thang nguyen Aihong Zhang Jianxiu Hao Weihong Wang Key Laboratory of Biobased Material Science&Technology(Ministry of Education) Northeast Forestry UniversityHarbin 150040China

Eucalyptus urophylla, Acacia mangium, and Pinus caribaea are the primary species for the wood industry in Vietnam. Wood residues of these species were used to reinforce high-density polyethylene(HDPE) composites. The flexural or bending property, impact strength and surface color were evaluated after exposure to accelerated ultraviolet weathering up to 2000 h. The weathered surface was characterized by scanning electron microscopy(SEM) and Fourier transform infrared(FTIR) spectroscopy. The results indicate that A. mangium/HDPE composites had the lowest color change and least fading,and remained stable after 1500 h exposure. FTIR spectroscopy showed that the oxidation of the composites increased in parallel with duration of exposure by assessing the concentration of carbonyl groups on the surfaces. SEM showed that all three species reinforced composites exhibited similar severe cracks after 1000 h;however, at the end of the weathering test, E. urophylla and P. caribaea composites were more severely cracked than A. mangium composites. A. mangium also had the highest flexural strength, impact strength and crystallinity duringweathering. A. mangium is the most preferable among the three species to reinforce HDPE.

关键词： Eucalyptus urophylla Acacia mangium Pinus caribaea Polyethylene Weathering Color Mechanical property

来源：

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

Metagenomic markings of myeloid malignancies

引用

Genes & Diseases 2023年第1期10卷 4-6页

作者： An dinh Duy nguyen Maryssa Shanteau-Jackson Thomas LaFramboise Department of Genetics and Genome Sciences School of MedicineCase Western Reserve UniversityClevelandOH44106USA

Human microbiome studies have exploded in number in recent years with the advent of high-throughput sequencing *** dramatic increase in sensitivity facilitated by deep-sequencing capability has led to hundreds of studies characterizing microbial communities in multiple human tissues,as well as the relationships between the composition of these communities and disease.

关键词： methods. myeloid hundreds

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：