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海洋测线网平差中拟稳测线系统误差的影响 被引量:3
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作者 李明叁 刘雁春 +2 位作者 黄谟涛 暴景阳 肖付民 《海洋测绘》 2003年第1期13-17,共5页
分析了海洋测线网平差中拟稳测线系统误差对参数解和系统误差检验的影响 ,提出了选择拟稳测线的t检验选取法。并通过仿真分析了拟稳测线系统误差的影响和选择方法的有效性。
关键词 海洋线 线系统误差 稳转移效应 淹没效应 t检验选取法 平差
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海洋磁力测量测点拟合方法研究
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作者 孙昊 杨波 +2 位作者 张亚彪 裴红松 林海峰 《海洋测绘》 2008年第5期56-58,共3页
基于海洋磁力测量的动态性特点,提出了测线分段滑动拟合法,并通过实例证明了其可行性和有效性,结果表明,分段滑动拟合法可以提高海洋磁力测量数据的处理精度。
关键词 海洋磁力 线 滑动
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考虑航磁水平梯度变化的ΔT网格化方法研究 被引量:12
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作者 谢汝宽 王平 +3 位作者 郭华 段树岭 刘浩军 王金龙 《地球物理学报》 SCIE EI CAS CSCD 北大核心 2013年第2期660-666,共7页
实测航磁横向水平梯度反映垂直于测线的磁场梯度,比传统航磁ΔT数据包含测线之间更多的磁场信息.针对航磁数据网格化问题,采用Hardwick提出的方法,利用航磁水平梯度与ΔT数据构建拟测线,并结合Akima插值法,开展了双方向测线型ΔT网格化... 实测航磁横向水平梯度反映垂直于测线的磁场梯度,比传统航磁ΔT数据包含测线之间更多的磁场信息.针对航磁数据网格化问题,采用Hardwick提出的方法,利用航磁水平梯度与ΔT数据构建拟测线,并结合Akima插值法,开展了双方向测线型ΔT网格化方法研究,最终实现了考虑航磁水平梯度变化的ΔT网格化;针对网格化结果中的虚假异常采取了有效滤波方法.通过理论模型数据和实际数据网格化处理,表明该方法可以突出航磁测线之间的异常细节、更清晰地反映线性构造或磁性体走向,提高了网格化的精度和分辨率. 展开更多
关键词 航磁水平梯度 增强网格化 拟测线 Akima插值法 双方向线型网格化
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Etvs效应改正中航速、航向角计算方法研究 被引量:7
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作者 于波 刘雁春 +3 位作者 暴景阳 翟国君 边刚 肖付民 《测绘科学》 CSCD 北大核心 2007年第3期80-82,共3页
Etvs效应是影响海洋重力测量精度的主要误差之一,为了减小由定位误差所引起的Etvs效应改正误差,本文基于对常用的直接差分算法进行分析,提出了测线滑动拟合算法。理论研究和实例计算结果表明以测线滑动拟合算法求定航速、航向... Etvs效应是影响海洋重力测量精度的主要误差之一,为了减小由定位误差所引起的Etvs效应改正误差,本文基于对常用的直接差分算法进行分析,提出了测线滑动拟合算法。理论研究和实例计算结果表明以测线滑动拟合算法求定航速、航向角比通常采用的直接差分算法使Etvs效应改正精度明显提高。 展开更多
关键词 海洋重力 Eotvos效应改正 线滑动
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Polar Functions for Fractional Brownian Motion
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作者 肖益民 《Chinese Quarterly Journal of Mathematics》 CSCD 1992年第1期76-80,共5页
Let X (t)(t∈R^N) be a d-dimensional fractional Brownian motion. A contiunous function f:R^N→R^d is called a polar function of X(t)(t∈R^N) if P{ t∈R^N\{0},X(t)=t(t)}=0. In this paper, the characteristies of the cla... Let X (t)(t∈R^N) be a d-dimensional fractional Brownian motion. A contiunous function f:R^N→R^d is called a polar function of X(t)(t∈R^N) if P{ t∈R^N\{0},X(t)=t(t)}=0. In this paper, the characteristies of the class of polar functions are studied. Our theorem 1 improves the previous results of Graversen and Legall. Theorem2 solves a problem of Legall (1987) on Brownian motion. 展开更多
关键词 fractional Brownian motion polar function Lipschitz function class quasi-helix Hausdorff dimension
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一种新的AVO分析方法及其在西班牙Guadalquivir盆地的应用
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作者 C.Garcia-Mojonero 李玉萍 +1 位作者 蒋先勇 王金萍 《石油物探译丛》 1999年第5期58-63,共6页
本文介绍了一种新的AVO研究法,用于解释人员(由于有拟3D可视化模块)处理实际数据并且能够避免由于完全基于地震处理技术所带来的限制。 该研究区域(图1)位于西班牙西南Guadalquivir盆地的陆上部分,是一个和南部Betic褶皱和逆冲断层带(... 本文介绍了一种新的AVO研究法,用于解释人员(由于有拟3D可视化模块)处理实际数据并且能够避免由于完全基于地震处理技术所带来的限制。 该研究区域(图1)位于西班牙西南Guadalquivir盆地的陆上部分,是一个和南部Betic褶皱和逆冲断层带(活动边缘)有关的内陆盆地,位于一个向北延伸的古生代稳定边缘(非活动边缘)上。主要储层是晚中新世的浊积岩,其平均砂孔隙度为20~25%,平均纯产油层厚5~20m,有许多气显示。 展开更多
关键词 AVO CDP道集 线 线 地震勘探
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Correlating and Predicting the Solubilities of Solid n-Alkanes in Supercritical Ethane Using Carnahan-Starling-van der Waals Model 被引量:1
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作者 李红茹 李淑芬 沈炳谦 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2013年第12期1360-1369,共10页
The solubilities of some solid n-alkanes in supercritical ethane were correlated and predicted in this paper using the Carnahan-Starling-van der Waals model with a density-dependent parameter of a12.At a given tempera... The solubilities of some solid n-alkanes in supercritical ethane were correlated and predicted in this paper using the Carnahan-Starling-van der Waals model with a density-dependent parameter of a12.At a given temperature,the linear fit of the parameter of a12and the density of the supercritical solvent was used for solubility correlation,resulting in an average absolute average relative deviation(AARD)of 8.68%,which was between the values of the semiempirical models and the other compressed gas models used in this article.In the linear fit of the parameter of a12and the density of the solvent,the regressed slope m and intercept n of the linear fit can be correlated with the carbon atom number of solid n-alkanes and then the solubilities of solid n-alkanes in supercritical ethane can be predicted with the intercept n and slope m.The average AARD in solubility prediction was 26.99%. 展开更多
关键词 supercritical ethane solid n-alkanes Carnahan-Starling-van der Waals model solubility
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Simulation of X-ray Diffraction Line Broadening Caused by Stress Gradients and Determination of Stress Distribution by Fourier Analysis
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作者 Vladimir Ivanovltch Monin Joaquim Teixera de Assis Susana Marrero Iglesias 《Journal of Chemistry and Chemical Engineering》 2012年第9期838-842,共5页
Different physical, mechanical and chemical processes, such as: ion implantation, oxidation, nitridation and others create on the surface of materials residual stress state, characterized by high level and strong gra... Different physical, mechanical and chemical processes, such as: ion implantation, oxidation, nitridation and others create on the surface of materials residual stress state, characterized by high level and strong gradient. X-ray diffraction method widely used for stress measurements has some difficulties in interpretation of experimental data, when the depth of X-ray penetration is compared with thickness of surface layer where inhomogeneous stress distribution is localized. Early it has been shown by authors that diffraction line broadening occurs when analyzed surface is characterized by strong gradient. The interest to study the diffraction line broadening is connected to the possibility of obtaining information about parameters of surface stress distribution. In the present paper the convolution and deconvolution concepts of Fourier analysis were applied to study X ray diffraction line broadening caused by surface stress gradients. Developed methodology allows determining of stress distribution in superficial layers of materials. 展开更多
关键词 Stress gradient X-ray diffraction computer simulation Fourier analysis.
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Herz Spaces on Nilpotent Lie Groups and Its Applications
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作者 ZHUYue-ping LIDeng-feng 《Chinese Quarterly Journal of Mathematics》 CSCD 2003年第1期74-81,共8页
In this paper, we define Herz type spaces on nilpotent Lie groups and give the boundedess of heat kernel and Riesz transform on Herz spaces.
关键词 nilpotent Lie groups Herz spaces heat kernel
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Prediction of Debris-flow Danger Area by Combining Hydrological and Inundation Simulation Methods 被引量:32
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作者 CUI Peng 《Journal of Mountain Science》 SCIE CSCD 2011年第1期1-9,共9页
Debris flows have caused serious human casualties and economic losses in the regions strongly affected by the Ms8.0 Wenchuan earthquake of 2oo8. Debris flow mitigation and risk assessment is a key issue for reconstruc... Debris flows have caused serious human casualties and economic losses in the regions strongly affected by the Ms8.0 Wenchuan earthquake of 2oo8. Debris flow mitigation and risk assessment is a key issue for reconstruction. The existing methods of inundation simulation are based on historical disasters and have no power of prediction. The rain- flood method can not yield detailed flow hydrograph and does not meet the need of inundation simulation. In this paper, the process of water flow was studied by using the Arc-SCS model combined with hydraulic method, and then the debris flow runoff process was calculated using the empirical formula combining the result from Arc-SCS. The peak discharge and runoff duration served as input of inundation simulation. Then, the dangerous area is predicted using kinematic wave method and Manning equation. Taking the debris flow in Huashiban gully in Beichuan County, Sichuan Province, China on 24 Sep. 2oo8 as example, the peak discharge of water flow and debris flow were calculated as 35.52 m3·s-1 and 215.66 m3·s-, with error of 4.15% compared to the measured values. The simulated area of debris-flow deposition was 161,500 m2, vs. the measured area of 144,097 m2, in error of 81.75%. The simulated maximum depth was 12.3 m, consistent with the real maximum depth between lO and 15 m according to the field survey. The minor error is mainly due to the flow impact on buildings and variations in cross-section configuration. The present methodology can be applied to predict debrisflow magnitude and evaluate its risk in other watersheds inthe earthquake area. 展开更多
关键词 Debris flow Arc-SCS model Inundation simulation Risk analysis Wenchuan earthquake
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Importance of a Well-distributed Frequency of Measurements in the Senescence Monitoring of Winter Wheat and Yield Estimates
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作者 Louis Kouadio Bakary Djaby Moussa El Jarroudi Bernard Tychon 《Journal of Agricultural Science and Technology(B)》 2012年第12期1203-1213,共11页
Theoretical frequencies of green area index (GAI) measurements were assessed in order to bring out the optimum frequencies for the monitoring of the senescence of winter wheat as well as the relationships between me... Theoretical frequencies of green area index (GAI) measurements were assessed in order to bring out the optimum frequencies for the monitoring of the senescence of winter wheat as well as the relationships between metrics which could be derived and the final grain yield. Several profiles of GAI decreasing curves were elaborated based on field measurements. Two functions, usually employed in green leaf area decreasing curves fitting (i.e., modified Gompertz and logistic functions) were then used to characterize the senescence phase and to calculate their metrics. These analyses showed that the two curve fitting functions satisfactorily described the senescence phase on frequencies of four to six GAI measurements, well distributed throughout a period of 30-35 days. The regression-based modeling showed that those involving metrics from logistic function (i.e., maximum value of GAI, green area duration and senescent rate) were more suitable than that of the modified Gompertz function for wheat yield estimates. Such results could be useful for studies at larger scales (involving remote sensing airplane or satellite data) and focused on the senescence in terms of optimum number of measurements and frequencies for developing models for yield estimates. 展开更多
关键词 Green area index SENESCENCE logistic function YIELD wheat.
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Mesomechanical simulation of direct shear test on outwash deposits with granular discrete element method 被引量:6
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作者 石崇 王盛年 +2 位作者 刘琳 孟庆祥 张强 《Journal of Central South University》 SCIE EI CAS 2013年第4期1094-1102,共9页
The mechanical properties of outwash deposits which are taken as unconsolidated geo-materials with the characteristics of non-uniformity, heterogeneity and multiphase have attracted much attention in engineering. Acco... The mechanical properties of outwash deposits which are taken as unconsolidated geo-materials with the characteristics of non-uniformity, heterogeneity and multiphase have attracted much attention in engineering. According to the results of laboratory direct shear test on the remolded samples, the soil particle parameters of numerical model based on in-situ particle size cumulative curves and 3D granular discrete element method were determined. Then, numerical experiments on different lithology, stone content and gradation composition were conducted. The results show that it is not a flat surface but a shear band that yields in the sample. The curve of particle velocity vs distance from the designed shear surface of test model that is taken as a datum plane in the vertical section of sample shows in "S" shape. The shear disturbance area is about twice the maximum diameter of stone blocks. The greater the stiffness of stone is, the rougher the shear surface is. The shear strength of outwash deposits is largely controlled by lithology and stone content, and the bite force between stone blocks is the root reason of larger friction angle. It is also shown that strain hardening and low shear dilatancy occur under high confining pressure as well as possibility of shear shrinkage. But it is easy to behave shear dilatation and strain softening under low confining pressure. The relationship between particle frictional coefficient and stone content presents an approximately quadratic parabola increase. The strain energy first increases and then drops with the increase of frictional energy. The cohesion increases with soil stiffness increasing but decreases with stone stiffness increasing. Numerical results are consistent with the laboratory test results of remolded samples, which indicate that this method can be a beneficial supplement to determine the parameters of engineering deposit bodies. 展开更多
关键词 outwash deposit direct shear test granular discrete element MESOMECHANICS
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Testing System Based on Virtual Instrument for Readout Circuit of Infrared Focal Plane Array
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作者 XUE Lian MENG Li-ya YUAN Xiang-hui 《Semiconductor Photonics and Technology》 CAS 2008年第2期102-106,114,共6页
Readout integrated circuit(ROIC) is one of the most important components for hybrid-integrated infrared focal plane array(IRFPA). And it should be tested to ensure the product yield before bonding. This paper presents... Readout integrated circuit(ROIC) is one of the most important components for hybrid-integrated infrared focal plane array(IRFPA). And it should be tested to ensure the product yield before bonding. This paper presents an on-wafer testing system based on Labview for ROIC of IRFPA. The quantitative measurement can be conducted after determining whether there is row crosstalk or not in this system. This low-cost system has the benefits of easy expansion, upgrading, and flexibility, and it has been employed in the testing of several kinds of IRFPA ROICs to measure the parameters of saturated output voltage, non-uniformity, dark noise and dynamic range, etc. 展开更多
关键词 virtual instrument infrared focal plane array ROIC TESTING
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Electric Energy Management Modeling for Kingdom of Bahrain
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作者 Isa Salman Qamber Mohammed Yusuf Al-Hamad Abdul Majeed Habib Abdul Karim 《Journal of Energy and Power Engineering》 2015年第10期872-885,共14页
In the deregulated economy, the maximum load forecasting is important for the electric industry. Many applications are included such as the energy generation and purchasing. The aim of the present study is to find the... In the deregulated economy, the maximum load forecasting is important for the electric industry. Many applications are included such as the energy generation and purchasing. The aim of the present study is to find the most suitable models for the peak load of the Kingdom of Bahrain. Many mathematical methods have been developing for maximum load forecasting. In the present paper, the modeling of the maximum load, population and GDP (gross domestic product) versus years obtained. The curve fitting technique used to find that models, where Graph 4.4.2 as a tool used to find the models. As well, Neuro-Fuzzy used to find the three models. Therefore, three techniques are used. These three are exponential, linear modeling and Neuro-Fuzzy. It is found that, the Neuro-Fuzzy is the most suitable and realistic one. Then, the linear modeling is the next suitable one. 展开更多
关键词 NEURO-FUZZY peak loads POPULATION GDP Graph 4.4.2 curve fitting.
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Energy and long-term hygrothermal performance of building enclosures based on dynamic environmental simulation test 被引量:1
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作者 Shi Xing 《Engineering Sciences》 EI 2010年第1期92-96,共5页
Dynamic environmental testing is an effective means to study the energy and long-term hygrothermal performance of building enclosures. Southeast University is designing and building a large-scale dynamic environment s... Dynamic environmental testing is an effective means to study the energy and long-term hygrothermal performance of building enclosures. Southeast University is designing and building a large-scale dynamic environment simulation testing facility. It can simuhaneously and dynamically simulate temperature, relative humidity, infrared solar radiation, UV radiation, and precipitation. A transformation is needed to predict the energy and long-term hygrothermal performance of building enclosures under real service conditions using data obtained from accelerated tests. 展开更多
关键词 environmental simulation hygrothermal performance long-term performance heat box environmental acceleration
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Conventional and Predictive Control Algorithms for Controlling Nonlinear Processes Using Multiple-Model Approach 被引量:1
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作者 Ma'moun Abu-Ayyad Issam Abu-Mahfouz Amit Banerjee 《Journal of Mechanics Engineering and Automation》 2013年第1期22-28,共7页
The objective of this work is to formulate and demonstrate the methodology of multi-models for improving the performance of existing advanced control strategies. Multiple models are used to capture the nonlinear proce... The objective of this work is to formulate and demonstrate the methodology of multi-models for improving the performance of existing advanced control strategies. Multiple models are used to capture the nonlinear process dynamics relating to gain and time constant variations. The multi-model strategy was implemented on several controllers such as Smith-Predictor using PI (Proportional-lntegral) and GPC (Generalized Predictive Control). Computer simulations and experiments were conducted on several nonlinear systems and compared to the original form of these controllers. The enhanced approach was tested on controlling the screw speed of an injection molding machine and temperature of a steel cylinder. 展开更多
关键词 Multi-models Smith-Predictor generalized predictive control.
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Measurement and Simulation of Energy Consumption of Feed Drive Systems
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作者 Akio Hayashi Ryoma Iwase Ryuta Sato Keiichi Shirase 《Journal of Mechanics Engineering and Automation》 2014年第3期203-212,共10页
In this study, in order to investigate the power consumption of feed drive system, mathematical models for the single-axis experimental apparatus are developed. This apparatus can be driven by either of ball screw or ... In this study, in order to investigate the power consumption of feed drive system, mathematical models for the single-axis experimental apparatus are developed. This apparatus can be driven by either of ball screw or linear motor and it is possible to change the mechanical properties of such as grease viscosity of the table. Then, the power consumption is simulated by proposed method based on the mathematical model of feed drive systems and the simulated results are compared with the measured results of the experimental apparatus to confirm the validity of the proposed method. In addition, it is clarified that the energy usages of the feed drive system. The energy losses of the feed drive system are divided into the loss of each part and these energy losses are calculated by the proposed method. Then, it is investigated that the influence of the velocity and friction to the energy consumption of feed drive system. As the results, it is confirmed that proposed method can accurately predict the power consumption of the ball-screw feed drive system. It is also clarified that the energy usage for both of ball-screw and linear motor drive systems. 展开更多
关键词 Energy consumption feed drive system mathematical model ball screw linear motor.
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Exact Boundary Controllability and Exact Boundary Observability for a Coupled System of Quasilinear Wave Equations 被引量:4
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作者 Long HU Fanqiong JI Ke WANG 《Chinese Annals of Mathematics,Series B》 SCIE CSCD 2013年第4期479-490,共12页
Based on the theory of semi-global classical solutions to quasilinear hyperbolic systems, the authors apply a unified constructive method to establish the local exact boundary(null) controllability and the local bound... Based on the theory of semi-global classical solutions to quasilinear hyperbolic systems, the authors apply a unified constructive method to establish the local exact boundary(null) controllability and the local boundary(weak) observability for a coupled system of 1-D quasilinear wave equations with various types of boundary conditions. 展开更多
关键词 Coupled system of quasilinear wave equations Exact boundary control-lability Exact boundary observability
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Simulations of lunar equatorial regolith temperature profile based on measurements of Diviner on Lunar Reconnaissance Orbiter 被引量:1
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作者 RAN Zhen WANG ZhenZhan 《Science China Earth Sciences》 SCIE EI CAS 2014年第9期2232-2241,共10页
Lunar equatorial regolith temperature profiles were simulated using the half-limited solid heat conduction model. Based on the infrared data measured using the Diviner radiometer on the Lunar Reconnaissance Orbiter la... Lunar equatorial regolith temperature profiles were simulated using the half-limited solid heat conduction model. Based on the infrared data measured using the Diviner radiometer on the Lunar Reconnaissance Orbiter launched by the United Sates in June 2009, three factors influencing temperature profiles were analyzed. The infrared brightness temperature data from Diviner channel 7 were used to retrieve surface temperature. In simulating regolith temperature profiles, the retrieved temperature, rather than temperatures calculated from solar radiance at the lunar surface, were used as the input for surface temperature in solving the heat-conductive equation. The results showed that the bottom-layer temperature at depths of 6 m approached almost 246 K after 10000 iterations. The temperature was different to the temperature of 250 K at the same depth encountered in simulations using solar radiance. Simulations from both methods of surface temperatures over a lunar day gave similar variations. At lunar night, the temperature difference between the two was about 2 K; the main differences occurred when the solar elevation angle was very low when surface temperatures are largely affected by terrain topography. With no certainty in lunar temperature profiles at present, the advantage of the retrieval method using infrared sensor data as input to the boundary conditions in solving the lunar heat conduction equation is that simulations of surface temperature variations are more accurate. This is especially true in areas with large variations in terrain topography, where surface temperatures vary greatly because of shading from the sunlight. 展开更多
关键词 Diviner radiometer equation of heat conduction lunar temperature profile infrared brightness temperature
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Shifted Boubaker Lagrangian approach for solving biological systems
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作者 Kourosh Parand Hossein Yousefi +2 位作者 Mina Fotouhifar Mehdi Delkhosh Mehdi Hosseinzadeh 《International Journal of Biomathematics》 SCIE 2018年第3期155-175,共21页
Mathematical models and computer simulations are useful experimental tools for building and testing theories. Many mathematical models in biology can be formulated by a nonlinear system of ordinary differential equati... Mathematical models and computer simulations are useful experimental tools for building and testing theories. Many mathematical models in biology can be formulated by a nonlinear system of ordinary differential equations. This work deals with the numerical solution of the hantavirus infection model, the human immunodeficiency virus (HIV) infection model of CD4^+T cells and the susceptible-infected-removed (SIR) epidemic model using a new reliable algorithm based on shifted Boubaker Lagrangian (SBL) method. This method reduces the solution of such system to a system of linear or non- linear algebraic equations which are solved using the Newton iteration method. The obtained results of the proposed method show highly accurate and valid for an arbitrary finite interval. Also, those are compared with fourth-order Runge-Kutta (RK4) method and with the solutions obtained by some other methods in the literature. 展开更多
关键词 Hantavirus infection model HIV infection model of CD4^+T cells SIR epi- demic model system of nonlinear differential equations Lagrangian method Boubaker polynomials.
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