期刊文献+
共找到90篇文章
< 1 2 5 >
每页显示 20 50 100
Coupling Modeling for Functional Surface of Electronic Equipment
1
作者 Baoyan DUAN Congsi WANG Wei WANG 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2017年第3期497-499,共3页
High performance electromechanical equipment is widely used in various fields, such as national defense, industry and so on [ 1]. In addition, the technical level of high performance electromechanical equipment is the... High performance electromechanical equipment is widely used in various fields, such as national defense, industry and so on [ 1]. In addition, the technical level of high performance electromechanical equipment is the embodiment of the national level of science and technology. 展开更多
关键词 TT Coupling modeling for functional Surface of Electronic Equipment
下载PDF
Generalized functional model of maximum and minimum detectable deformation gradient for PALSAR interferometry 被引量:2
2
作者 王琪洁 李志伟 +4 位作者 杜亚男 谢荣安 张杏清 蒋弥 朱建军 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2014年第3期824-832,共9页
Empirical functional models for the maximum and minimum detectable deformation gradient of PALSAR interferometry were established based on coherence and discrete look numbers. Then, a least square regression method wa... Empirical functional models for the maximum and minimum detectable deformation gradient of PALSAR interferometry were established based on coherence and discrete look numbers. Then, a least square regression method was used to fit the model coefficients and thus obtain the generalized functional models for both coherence and look numbers. The experimental results with ALOS PALSAR data of Wenchuan earthquake of China show that the new model works well for judging whether the deformation gradient can be detected by the D-InSAR technology or not. The results can help researchers to choose PALSAR data and to configure processing parameters, and also benefit the interpretation of the measured surface deformation. 展开更多
关键词 PALSAR D-INSAR deformation gradient COHERENCE multilook number functional model
下载PDF
Introducing the nth-Order Features Adjoint Sensitivity Analysis Methodology for Nonlinear Systems (nth-FASAM-N): II. Illustrative Example
3
作者 Dan Gabriel Cacuci 《American Journal of Computational Mathematics》 2024年第1期43-95,共54页
This work highlights the unparalleled efficiency of the “n<sup>th</sup>-Order Function/ Feature Adjoint Sensitivity Analysis Methodology for Nonlinear Systems” (n<sup>th</sup>-FASAM-N) by con... This work highlights the unparalleled efficiency of the “n<sup>th</sup>-Order Function/ Feature Adjoint Sensitivity Analysis Methodology for Nonlinear Systems” (n<sup>th</sup>-FASAM-N) by considering the well-known Nordheim-Fuchs reactor dynamics/safety model. This model describes a short-time self-limiting power excursion in a nuclear reactor system having a negative temperature coefficient in which a large amount of reactivity is suddenly inserted, either intentionally or by accident. This nonlinear paradigm model is sufficiently complex to model realistically self-limiting power excursions for short times yet admits closed-form exact expressions for the time-dependent neutron flux, temperature distribution and energy released during the transient power burst. The n<sup>th</sup>-FASAM-N methodology is compared to the extant “n<sup>th</sup>-Order Comprehensive Adjoint Sensitivity Analysis Methodology for Nonlinear Systems” (n<sup>th</sup>-CASAM-N) showing that: (i) the 1<sup>st</sup>-FASAM-N and the 1<sup>st</sup>-CASAM-N methodologies are equally efficient for computing the first-order sensitivities;each methodology requires a single large-scale computation for solving the “First-Level Adjoint Sensitivity System” (1<sup>st</sup>-LASS);(ii) the 2<sup>nd</sup>-FASAM-N methodology is considerably more efficient than the 2<sup>nd</sup>-CASAM-N methodology for computing the second-order sensitivities since the number of feature-functions is much smaller than the number of primary parameters;specifically for the Nordheim-Fuchs model, the 2<sup>nd</sup>-FASAM-N methodology requires 2 large-scale computations to obtain all of the exact expressions of the 28 distinct second-order response sensitivities with respect to the model parameters while the 2<sup>nd</sup>-CASAM-N methodology requires 7 large-scale computations for obtaining these 28 second-order sensitivities;(iii) the 3<sup>rd</sup>-FASAM-N methodology is even more efficient than the 3<sup>rd</sup>-CASAM-N methodology: only 2 large-scale computations are needed to obtain the exact expressions of the 84 distinct third-order response sensitivities with respect to the Nordheim-Fuchs model’s parameters when applying the 3<sup>rd</sup>-FASAM-N methodology, while the application of the 3<sup>rd</sup>-CASAM-N methodology requires at least 22 large-scale computations for computing the same 84 distinct third-order sensitivities. Together, the n<sup>th</sup>-FASAM-N and the n<sup>th</sup>-CASAM-N methodologies are the most practical methodologies for computing response sensitivities of any order comprehensively and accurately, overcoming the curse of dimensionality in sensitivity analysis. 展开更多
关键词 Nordheim-Fuchs Reactor Safety Model Feature Functions of Model Parameters High-Order Response Sensitivities to Parameters Adjoint Sensitivity Systems
下载PDF
Development of Mathematical Model on Preparation of Functionally Graded Material by Co-sedimentation 被引量:6
4
作者 Zhongmin YANG, Lianmeng ZHANG and Qiang SHEN Institute of Materials Science and Engineering, Wuhan University of Technology, Wuhan 430070, China 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 2001年第2期275-277,共3页
From the process of sedimentation the mathematical relationships among deposition Volume and powder properties as well as sedimentation parameters were deduced. Based on the formula a mathematical model was set up and... From the process of sedimentation the mathematical relationships among deposition Volume and powder properties as well as sedimentation parameters were deduced. Based on the formula a mathematical model was set up and simulated through the computer. At last the validity of mathematical model was supported by the representative experiment on Ti-Mo system FGM prepared by co-sedimentation. 展开更多
关键词 CO MO Development of Mathematical Model on Preparation of functionally Graded Material by Co-sedimentation
下载PDF
Time lag characteristics of sap flow in seed-maize and their implications for modeling transpiration in an arid region of Northwest China 被引量:5
5
作者 BO Xiaodong DU Taisheng +1 位作者 DING Risheng Louise COMAS 《Journal of Arid Land》 SCIE CSCD 2017年第4期515-529,共15页
Plant capacity for water storage leads to time lags between basal stem sap flow and transpiration in various woody plants. Internal water storage depends on the sizes of woody plants. However, the changes and its infl... Plant capacity for water storage leads to time lags between basal stem sap flow and transpiration in various woody plants. Internal water storage depends on the sizes of woody plants. However, the changes and its influencing factors in time lags of basal stem flow during the development of herbaceous plants including crops remain unclear. A field experiment was conducted in an arid region of Northwest China to examine the time lag characteristics of sap flow in seed-maize and to calibrate the transpiration modeling. Cross-correlation analysis was used to estimate the time lags between stem sap flow and meteorological driving factors including solar radiation(R_s) and vapor pressure deficit of the air(VPD_(air)). Results indicate that the changes in seed-maize stem sap flow consistently lagged behind the changes in R_s and preceded the changes in VPD_(air) both on hourly and daily scales, suggesting that light-mediated stomatal closures drove sap flow responses. The time lag in the maize's sap flow differed significantly during different growth stages and the difference was potentially due to developmental changes in capacitance tissue and/or xylem during ontogenesis. The time lags between stem sap flow and R_s in both female plants and male plants corresponded to plant use of stored water and were independent of total plant water use. Time lags of sap flow were always longer in male plants than in female plants. Theoretically, dry soil may decrease the speed by which sap flow adjusts ahead of shifts in VPD_(air) in comparison with wet soil and also increase the speed by which sap flow adjusts to R_s. However, sap flow lags that were associated with R_s before irrigation and after irrigation in female plants did not shift. Time series analysis method provided better results for simulating seed-maize sap flow with advantages of allowing for fewer variables to be included. This approach would be helpful in improving the accuracy of estimation for canopy transpiration and conductance using meteorological measurements. 展开更多
关键词 seed-maize sap flow capacitance transfer function model time lag stored water use
下载PDF
Hybrid graded element model for transient heat conduction in functionally graded materials 被引量:4
6
作者 Lei-Lei Cao Qing-Hua Qin Ning Zhao 《Acta Mechanica Sinica》 SCIE EI CAS CSCD 2012年第1期128-139,共12页
This paper presents a hybrid graded element model for the transient heat conduction problem in functionally graded materials (FGMs). First, a Laplace transform approach is used to handle the time variable. Then, a f... This paper presents a hybrid graded element model for the transient heat conduction problem in functionally graded materials (FGMs). First, a Laplace transform approach is used to handle the time variable. Then, a fundamental solution in Laplace space for FGMs is constructed. Next, a hybrid graded element is formulated based on the obtained fundamental solution and a frame field. As a result, the graded properties of FGMs are naturally reflected by using the fundamental solution to interpolate the intra-element field. Further, Stefest's algorithm is employed to convert the results in Laplace space back into the time-space domain. Finally, the performance of the proposed method is assessed by several benchmark examples. The results demonstrate well the efficiency and accuracy of the proposed method. 展开更多
关键词 Graded element model functionally graded materials Hybrid FEM Transient heat conduction
下载PDF
Developing theory of probability density function for stochastic modeling of turbulent gas-particle flows
7
作者 Lixing ZHOU 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI CSCD 2018年第7期1019-1030,共12页
Turbulent gas-particle flows are studied by a kinetic description using a prob- ability density function (PDF). Unlike other investigators deriving the particle Reynolds stress equations using the PDF equations, the... Turbulent gas-particle flows are studied by a kinetic description using a prob- ability density function (PDF). Unlike other investigators deriving the particle Reynolds stress equations using the PDF equations, the particle PDF transport equations are di- rectly solved either using a finite-difference method for two-dimensional (2D) problems or using a Monte-Carlo (MC) method for three-dimensional (3D) problems. The proposed differential stress model together with the PDF (DSM-PDF) is used to simulate turbulent swirling gas-particle flows. The simulation results are compared with the experimental results and the second-order moment (SOM) two-phase modeling results. All of these simulation results are in agreement with the experimental results, implying that the PDF approach validates the SOM two-phase turbulence modeling. The PDF model with the SOM-MC method is used to simulate evaporating gas-droplet flows, and the simulation results are in good agreement with the experimental results. 展开更多
关键词 probability density function(PDF)modeling turbulent flow gas-particleflow
下载PDF
CONCEPTUAL MODELING BASED ON LOGICAL EXPRESSION AND EVOLVEMENT
8
作者 YI Guodong ZHANG Shuyou TAN Jianrong JI Yangjian 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2007年第1期64-68,共5页
Aiming at the problem of abstract and polytype information modeling in product conceptual design, a method of conceptual modeling based on logical expression and evolvement is presented. Based on the logic expressions... Aiming at the problem of abstract and polytype information modeling in product conceptual design, a method of conceptual modeling based on logical expression and evolvement is presented. Based on the logic expressions of the product conceptual design information, a fimction/logic/strucmre mapping model is set up. First, the fimction semantics is transformed into logical expressions through fimction/logic mapping. Second, the methods of logical evolvement are utilized to describe the fimction analysis, fimction/strucmre mapping and structure combination. Last, the logical structure scheme is transformed into geometrical sketch through logic/structure mapping. The conceptual design information and modeling process are described uniformly with logical methods in the model, and an effective method for computer aided conceptual design based on the model is implemented. 展开更多
关键词 Conceptual modeling Function/logic/structure mapping Logical evolvement
下载PDF
Modeling of Transient Thermal Conditions in Cutting
9
作者 T. Augspurger F. Klocke +3 位作者 B. Dobbeler M. Brockmann S. Gierlings A. Lima 《Journal of Mechanics Engineering and Automation》 2017年第3期113-119,共7页
The thermal conditions like the temperature distribution and the heat fluxes during metal cutting have a major influence on the machinability, the tool lifetime, the metallurgical structure and thus the functionality ... The thermal conditions like the temperature distribution and the heat fluxes during metal cutting have a major influence on the machinability, the tool lifetime, the metallurgical structure and thus the functionality of the work piece. This in particular applies for manufacturing processes like milling, drilling and turning for high-value turbomachinery components like impellers, combustion engines and compressors of the aerospace and automotive industry as well as energy generation, which play a major role in modern societies. However, numerous analytical and experimental efforts have been conducted in order to understand the thermal conditions in metal cutting, yet many questions still prevail. Most models are based on a stationary point of view and do not include time dependent effects like in intensity and distribution varying heat sources, varying engagement conditions and progressive tool wear. In order to cover such transient physics an analytical approach based on Green's functions for the solution of the partial differential equations of unsteady heat conduction in solids is used to model entire transient temperature fields. The validation of the model is carried out in orthogonal cutting experiments not only punctually but also for entire temperature fields. For these experiments an integrated measurement of prevailing cutting force and temperature fields in the tool and the chip by means of high-speed thermography were applied. The thermal images were analyzed with regard to thermodynamic energy balancing in order to derive the heat partition between tool, chips and workpiece. The thus calculated heat flow into the tool was subsequently used in order to analytically model the transient volumetric temperature fields in the tool. The described methodology enables the modeling of the transient thermal state in the cutting zone and particular in the tool, which is directly linked to phenomena like tool wear and workpiece surface modifications. 展开更多
关键词 Metal cutting infrared thermography heat sources transient temperature fields model based on Green's functions.
下载PDF
Recent Advances in the Geodesy Data Processing 被引量:1
10
作者 Jianjun ZHU Leyang WANG +3 位作者 Jun HU Bofeng LI Haiqiang FU Yibin YAO 《Journal of Geodesy and Geoinformation Science》 CSCD 2023年第3期33-45,共13页
Geodetic functional models,stochastic models,and model parameter estimation theory are fundamental for geodetic data processing.In the past five years,through the unremitting efforts of Chinese scholars in the field o... Geodetic functional models,stochastic models,and model parameter estimation theory are fundamental for geodetic data processing.In the past five years,through the unremitting efforts of Chinese scholars in the field of geodetic data processing,according to the application and practice of geodesy,they have made significant contributions in the fields of hypothesis testing theory,un-modeled error,outlier detection,and robust estimation,variance component estimation,complex least squares,and ill-posed problems treatment.Many functional models such as the nonlinear adjustment model,EIV model,and mixed additive and multiplicative random error model are also constructed and improved.Geodetic data inversion is an important part of geodetic data processing,and Chinese scholars have done a lot of work in geodetic data inversion in the past five years,such as seismic slide distribution inversion,intelligent inversion algorithm,multi-source data joint inversion,water reserve change and satellite gravity inversion.This paper introduces the achievements of Chinese scholars in the field of geodetic data processing in the past five years,analyzes the methods used by scholars and the problems solved,and looks forward to the unsolved problems in geodetic data processing and the direction that needs further research in the future. 展开更多
关键词 stochastic model functional model robust estimation variance component estimation geodetic data inversion
下载PDF
Construction of Psychological Adjustment Function Model of Music Education Based on Emotional Tendency Analysis
11
作者 Bin Zhang 《International Journal of Mental Health Promotion》 2023年第5期655-671,共17页
In the face offierce competition in the social environment,mental health problems gradually get the attention of the public,in order to achieve accurate mental health data analysis,the construction of music education ... In the face offierce competition in the social environment,mental health problems gradually get the attention of the public,in order to achieve accurate mental health data analysis,the construction of music education is based on emotional tendency analysis of psychological adjustment function model.Design emotional tendency analysis of music education psychological adjustment function architecture,music teaching goal as psychological adjust-ment function architecture building orientation,music teaching content as a foundation for psychological adjust-ment function architecture and music teaching process as a psychological adjustment function architecture building,music teaching evaluation as the key of building key regulating function architecture,Establish a core literacy oriented evaluation system.Different evaluation methods were used to obtain the evaluation results.Four levels of psychological adjustment function model of music education are designed,and the psychological adjust-ment function of music education is put forward,thus completing the construction of psychological adjustment function model of music education.The experimental results show that the absolute value of the data acquisition error of the designed model is minimum,which is not more than 0.2.It is less affected by a bad coefficient and has good performance.It can quickly converge to the best state in the actual prediction process and has a strong con-vergence ability. 展开更多
关键词 Emotional tendency analysis music education psychological adjustment functional model core literacy orientation
下载PDF
Development of Comprehensive PNT and Resilient PNT
12
作者 Xia REN Yuanxi YANG 《Journal of Geodesy and Geoinformation Science》 CSCD 2023年第3期1-8,共8页
Any single Positioning,Navigation and Timing(PNT)technology has its vulnerability and limits,even the powerful Global Navigation Satellite System(GNSS)is no exception.To provide continuous and reliable PNT information... Any single Positioning,Navigation and Timing(PNT)technology has its vulnerability and limits,even the powerful Global Navigation Satellite System(GNSS)is no exception.To provide continuous and reliable PNT information to users,the theory and technique of comprehensive PNT information system and resilient PNT application system have attracted great attention from Chinese scholars.We try to summarize the progress and development of the synthetic PNT system,including the proposal,the modification and the improvement of the comprehensive PNT,as well as the follow-up resilient PNT.The frame of China’s comprehensive PNT system consisted of comprehensive PNT infrastructure and comprehensive PNT application system is initially described;the achievements on some main PNT technologies are introduced;the conceptual models of resilient PNT are given;besides,existing researches on resilient function models and stochastic models are summarized according to different user scenarios. 展开更多
关键词 GNSS comprehensive PNT resilient PNT resilient function model resilient stochastic model
下载PDF
Testing Linearity in Functional Partially Linear Models
13
作者 Fan-rong ZHAO Bao-xue ZHANG 《Acta Mathematicae Applicatae Sinica》 SCIE CSCD 2024年第3期875-886,共12页
For the functional partially linear models including flexible nonparametric part and functional linear part,the estimators of the nonlinear function and the slope function have been studied in existing literature.How ... For the functional partially linear models including flexible nonparametric part and functional linear part,the estimators of the nonlinear function and the slope function have been studied in existing literature.How to test the correlation between response and explanatory variables,however,still seems to be missing.Therefore,a test procedure for testing the linearity in the functional partially linear models will be proposed in this paper.A test statistic is constructed based on the existing estimators of the nonlinear and the slope functions.Further,we prove that the approximately asymptotic distribution of the proposed statistic is a chi-squared distribution under some regularity conditions.Finally,some simulation studies and a real data application are presented to demonstrate the performance of the proposed test statistic. 展开更多
关键词 asymptotic theory functional partially linear model Nadaraya-Watson estimate test statistic
原文传递
Synthesis,characterization and catalytic reactivity of pentacoordinate iron dicarbonyl as a model of the [Fe]-hydrogenase active site
14
作者 张天永 盛了 +4 位作者 杨秋生 姜爽 王艳红 金朝晖 李彬 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 北大核心 2015年第11期2011-2019,共9页
Two mono iron complexes Fe(CO)2PR3(NN) (R = Cy (3), Ph (4), NN = o-phenylenediamine dianion ligand, N2H2Ph2-) derived from the ligand substitution of Fe(CO)3hPR3 by the NN ligand were isolated and structur... Two mono iron complexes Fe(CO)2PR3(NN) (R = Cy (3), Ph (4), NN = o-phenylenediamine dianion ligand, N2H2Ph2-) derived from the ligand substitution of Fe(CO)3hPR3 by the NN ligand were isolated and structurally characterized by single crystal X-ray diffraction. They have a similar first coordination sphere and oxidation state of the iron center as the [Fe]-hydrogenase active site, and can be a model of it IR demonstrated that the effect of the NN ligand on the coordinated CO stretch- ing frequencies was due to its excellent electron donating ability. The reversible protonation/deprotonation of the NN ligand was identified by infrared spectroscopy and density functional theory computation. The NN ligand is an effective proton acceptor as the internal base of the cysteine thiolate ligand in [Fe]-hydrogenase. The electrochemical properties of complexes 3, 4 were investigated by cyclic voltammograms. Complex 3 catalyzed the transfer hydrogenation of benzoquinone to hydroquinone effectively under mild conditions. 展开更多
关键词 Mono iron hydrogenase Model complex Catalytic transfer hydrogenation functional analogue Benzoquinone
下载PDF
Functions of Allusions from Leppihalme’s model
15
作者 倪志莉 《魅力中国》 2009年第15期188-189,共2页
The general function of allusions is often thought to add clarity and significance to ideas and descriptions.However,it would be difficult to establish an exhaustive list of mutually exclusive category
关键词 Functions of Allusions from Leppihalme’s model
下载PDF
Sensitivity analysis of glacier systems to climate warming in China 被引量:25
16
作者 WANG Xin XIE Zichu +2 位作者 LI Qiaoyuan WANG Shuhong CHENG Lei 《Journal of Geographical Sciences》 SCIE CSCD 2008年第2期190-200,共11页
Data of 44 glacier systems in China used in this paper were obtained from Chinese Glacier Inventories and the meteorological data were got from Meteorological Atlas of Plateau of west China. Based on the statistical a... Data of 44 glacier systems in China used in this paper were obtained from Chinese Glacier Inventories and the meteorological data were got from Meteorological Atlas of Plateau of west China. Based on the statistical analysis and functional model simulation results of the 44 glacier systems in China, the glacier systems were divided into extremely-sensitive glacier system, semi-sensitive glacier system, extremely-steady glacier system and semi-steady glacier system in terms of glacier system's level of water-energy exchange, rising gradient of the equilibrium line altitudes and retreating rate of area to climate warming, their median size and vertical span distribution, and their runoff characteristics to climate warming. Furthermore the functional model of glacier system to climate warming was applied in this paper to predict the average variation trends of the 4 types of glacier systems, which indicate that different sensitivity types of glacier systems respond to the climate warming differently. 展开更多
关键词 glacier system functional model response to climate warming type of sensitivity
下载PDF
Single Point Positioning with Sequential Least-Squares Filter and Estimated Real-Time Stochastic Model 被引量:7
17
作者 WU Yun GUO Jiming 《Geo-Spatial Information Science》 2008年第1期13-16,共4页
To obtain higher accurate position estimates, the stochastic model is estimated by using residual of observations, hence, the stochastic model describes the noise and bias in measurements more realistically. By using ... To obtain higher accurate position estimates, the stochastic model is estimated by using residual of observations, hence, the stochastic model describes the noise and bias in measurements more realistically. By using GPS data and broadcast ephemeris, the numerical results indicating the accurate position estimates at sub-meter level are obtainable. 展开更多
关键词 GPS single point positioning functional model stochastic model sequential least-square filter
下载PDF
The Glacier Area Changes in the Qangtang Plateau Based on the Multi-temporal Grid Method and its Sensitivity to Climate Change 被引量:5
18
作者 WANG Liping XIE Zichu +3 位作者 WANG Xin LIU Shiyin DING Liangfu SHANGGUAN Donghui 《Journal of Mountain Science》 SCIE CSCD 2011年第6期882-893,共12页
Glacier area changes in the Qangtang Plateau are analyzed during 1970-2000 using air photos,relevant photogrammetric maps and satellite images based on the multi-temporal grid method.The results indicate that the melt... Glacier area changes in the Qangtang Plateau are analyzed during 1970-2000 using air photos,relevant photogrammetric maps and satellite images based on the multi-temporal grid method.The results indicate that the melting of glaciers accelerated,only a few of glaciers in an advancing state during 1970-2000 in the whole Qangtang Plateau.However,the glaciers seemed still more stable in the study area than in most areas of western China.We estimate that glacier retreat was likely due to air temperature warming during 1970-2000 in the Qangtang Plateau.Furthermore,the functional model of glacier system is applied to study climate sensitivity of glacier area changes,which indicates that glacier lifespan mainly depends on the heating rate,secondly the precipitation,and precipitation increasing can slow down glacier retreat and make glacier lifespan prolonged. 展开更多
关键词 The Qangtang Plateau Glacier change MULTI-TEMPORAL Climate change functional model ofglacier system Simulation
下载PDF
The Usage of Two Dielectric Function Models
19
作者 陈红 沈文忠 《Journal of Semiconductors》 EI CAS CSCD 北大核心 2006年第4期583-590,共8页
This paper presents an overview of the history, modifications, characteristics, and applications of two well known dielectric function models ——the Forouhi-Bloomer model and the Tauc-Lorentz model——which have been... This paper presents an overview of the history, modifications, characteristics, and applications of two well known dielectric function models ——the Forouhi-Bloomer model and the Tauc-Lorentz model——which have been widely used for the extraction and parameterization of optical constants in semiconductors and dielectrics. Based on analysis of their inherent characteristics and comparison via demonstrative examples, deeper and wider usage of the two models is predicted. 展开更多
关键词 dielectric function models optical constants SEMICONDUCTORS
下载PDF
PERFORMANCE ANALYSIS OF INTEGRATED GPS/GLONASS CARRIER PHASE-BASED POSITIONING 被引量:3
20
作者 DAI LiwenHAN ShaoweiChris Rizos 《Geo-Spatial Information Science》 2001年第4期9-18,共10页
Due to the different signal frequencies for the GLONASS satellites,the commonly-used double-differencing procedure for carrier phase data processing can not be implemented in its straightforward form,as in the case of... Due to the different signal frequencies for the GLONASS satellites,the commonly-used double-differencing procedure for carrier phase data processing can not be implemented in its straightforward form,as in the case of GPS.In this paper a novel data processing strategy,involving a three-step procedure,for integrated GPS/GLONASS positioning is proposed.The first is pseudo-range-based positioning,that uses double-differenced (DD) GPS pseudo-range and single-differenced (SD) GLONASS pseudo-range measurements to derive the initial position and receiver clock bias.The second is forming DD measurements (expressed in cycles) in order to estimate the ambiguities,by using the receiver clock bias estimated in the above step.The third is to form DD measurements (expressed in metric units) with the unknown SD integer ambiguity for the GLONASS reference satellite as the only parameter (which is constant before a cycle slip occurs for this satellite).A real-time stochastic model estimated by residual series over previous epochs is proposed for integrated GPS/GLONASS carrier phase and pseudo-range data processing.Other associated issues,such as cycle slip detection,validation criteria and adaptive procedure(s) for ambiguity resolution,is also discussed.The performance of this data processing strategy will be demonstrated through case study examples of rapid static positioning and kinematic positioning.From four experiments carried out to date,the results indicate that rapid static positioning requires 1 minute of single frequency GPS/GLONASS data for 100% positioning success rate.The single epoch positioning solution for kinematic positioning can achieve 94.6% success rate over short baselines (<6 km). 展开更多
关键词 GPS/GLONASS stochastic model functional model ambiguity resolution
下载PDF
上一页 1 2 5 下一页 到第
使用帮助 返回顶部