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Transfer Function Description of Multirate Sampling Systems
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作者 肖建 唐磊 《Journal of Modern Transportation》 1999年第2期141-147,共7页
Based on the sampler decomposition method and modified Z transform, this paper proposes a pulse transfer function matrix description of the multivariable multirate sampling systems. This multirate sampling system mode... Based on the sampler decomposition method and modified Z transform, this paper proposes a pulse transfer function matrix description of the multivariable multirate sampling systems. This multirate sampling system model has a simple structure, and can be used as a basis for the analysis and synthesis of the multirate sampling systems. 展开更多
关键词 multirate sampling system transfer function computer controlled system
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A novel carbon trap sampling system for coal-fired flue gas mercury measurement
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作者 汤红健 段钰锋 +3 位作者 朱纯 周强 佘敏 蔡亮 《Journal of Southeast University(English Edition)》 EI CAS 2015年第2期244-248,共5页
A novel carbon trap sampling system for gas-phase mercury measurement in flue gas is developed, including the high efficient sorbents made of modified biomass cokes and high precision sorbent traps for measuring parti... A novel carbon trap sampling system for gas-phase mercury measurement in flue gas is developed, including the high efficient sorbents made of modified biomass cokes and high precision sorbent traps for measuring particle-bound and total vapor-phase mercury in flue gas. A dedusting device is installed to collect fine fly ash for reducing the measurement errors. The thorough comparison test of mercury concentration in flue gas is conducted between the novel sampling system and the Ontario hydro method (OHM) in a 6 kW circulating fluidized bed combustor. Mercury mass balance rates of the OHM range from 95.47% to 104.72%. The mercury breakthrough rates for the second section of the sorbent trap are all below 2%. The relative deviations in the two test cases are in the range of 15. 96% to 17. 56% under different conditions. The verified data suggest that this novel carbon trap sampling system can meet the standards of quality assurance and quality control required by EPA Method 30B and can be applied to the coal-fired flue gas mercury sampling system. 展开更多
关键词 mercury sorbent trap coal-fired flue gas mercury sampling unit
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THE RESEARCH OF GRADATION FUSION ALGORITHM BASED ON MULTISENSOR ASYNCHRONOUS SAMPLING SYSTEM 被引量:3
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作者 Wen Chenglin Zhang Liantang Ge Quanbo 《Journal of Electronics(China)》 2005年第5期534-545,共12页
This letter explores the distributed multisensor dynamic system, which has uniform sampling velocity and asynchronous sampling data for different sensors, and puts forward a new gradation fusion algorithm of multisens... This letter explores the distributed multisensor dynamic system, which has uniform sampling velocity and asynchronous sampling data for different sensors, and puts forward a new gradation fusion algorithm of multisensor dynamic system. As the total forecasted increment value between the two adjacent moments is the forecasted estimate value of the corresponding state increment in the fusion center, the new algorithm models the state and the forecasted estimate value of every moment. Kalman filter and all measurements arriving sequentially in the fusion period are employed to update the evaluation of target state step by step, on the condition that the system has obtained the target state evaluation that is based on the overall information in the previous fusion period. Accordingly, in the present period, the fusion evaluation of the target state at each sampling point on the basis of the overall information can be obtained. This letter elaborates the form of this new algorithm. Computer simulation demonstrates that this new algorithm owns greater precision in estimating target state than the present asynchronous fusion algorithm calibrated in time does. 展开更多
关键词 Multisensor system Gradation fusion Asynchronous sampling Kalman filtering
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Digital discrimination of neutrons and γ rays with organic scintillation detectors in an 8-bit sampling system using frequency gradient analysis 被引量:4
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作者 杨俊 罗晓亮 +4 位作者 刘国富 林存宝 王艳玲 胡青青 彭进先 《Chinese Physics C》 SCIE CAS CSCD 2012年第6期544-551,共8页
The feasibility of using frequency gradient analysis (FGA), a digital method based on Fourier transform, to discriminate neutrons and T rays in the environment of an 8-bit sampling system has been investigated. The ... The feasibility of using frequency gradient analysis (FGA), a digital method based on Fourier transform, to discriminate neutrons and T rays in the environment of an 8-bit sampling system has been investigated. The performances of most pulse shape discrimination methods in a scintillation detection system using the time-domain features of the photomultiplier tube anode signal will be lower or non-effective in this low resolution sampling system. However, the FGA method using the frequency-domain features of the anode signal exhibits a strong insensitivity to noise and can be used to discriminate neutrons and ~/rays in the above sampling system. A detailed study of the quality of the FGA method in BC501A liquid scintillators is presented using a 5 G samples/s 8-bit oscilloscope and a 14.1 MeV neutron generator. A comparison of the discrimination results of the time-of-flight and conventional charge comparison (CC) methods proves the applicability of this technique. Moreover, FGA has the potential to be implemented in current embedded electronics systems to provide real-time discrimination in standalone instruments. 展开更多
关键词 n-y discrimination liquid scintillator FGA 8-bit sampling system
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Background-Free Optical Sampling System Using Si Avalanche Photodiode as Two-Photon Absorber
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作者 Kenji Taira Ryo Ohta +3 位作者 Yasuyuki Ozeki Yutaka Fukuchi Kazuhiro Katoh Kazuro Kikuchi 《光学学报》 EI CAS CSCD 北大核心 2003年第S1期587-588,共2页
The introduction of a double-chopping scheme eliminates the background level in the optical sampling system, where a Si avalanche photodiode acts as a two-photon absorber. We successfully demonstrate background-free o... The introduction of a double-chopping scheme eliminates the background level in the optical sampling system, where a Si avalanche photodiode acts as a two-photon absorber. We successfully demonstrate background-free optical sampling of 40-GHz and 160-GHz pulse trains. 展开更多
关键词 APD of for in AS TPA Background-Free Optical sampling system Using Si Avalanche Photodiode as Two-Photon Absorber EAM GHz test were dBm rate MLL
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Stability analysis of networked control systems with time-varying sampling periods 被引量:8
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作者 Fuchun LIU Yu YAO FenghuaHE Songlin CHEN 《控制理论与应用(英文版)》 EI 2008年第1期22-25,共4页
In this paper, we present an interval model of networked control systems with time-varying sampling periods and time-varying network-induced delays and discuss the problem of stability of networked control systems usi... In this paper, we present an interval model of networked control systems with time-varying sampling periods and time-varying network-induced delays and discuss the problem of stability of networked control systems using Lyapunov stability theory. A sufficient stability condition is obtained by solving a set of linear matrix inequalities. In the end, the illustrative example demonstrates the correctness and effectiveness of the proposed approach. 展开更多
关键词 Networked control systems (NCS) Time-varying sampling periods Network-induced delay Linear matrix inequality(LMI)
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Guaranteed cost control of networked control systems under limited communication capacity and variable sampling 被引量:3
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作者 刘英英 褚云凯 车伟伟 《Journal of Central South University》 SCIE EI CAS 2014年第3期978-986,共9页
The problem of guaranteed cost control for the networked control systems(NCSs) with time-varying delays, time-varying sampling intervals and signals quantization was investigated, wherein the physical plant was contin... The problem of guaranteed cost control for the networked control systems(NCSs) with time-varying delays, time-varying sampling intervals and signals quantization was investigated, wherein the physical plant was continuous-time one, and the control input was discrete-time one. By using an input delay approach and a sector bound method, the network induced delays, quantization parameter and sampling intervals were presented in one framework in the case of the state and the control input by quantized in a logarithmic form. A novel Lyapunov function with discontinuity, which took full advantages of the NCS characteristic information, was exploited. In addition, it was shown that Lyapunov function decreased at the jump instants. Furthermore, the Leibniz-Newton formula and free-weighting matrix methods were used to obtain the guaranteed cost controller design conditions which were dependent on the NCS characteristic information. A numerical example was used to illustrate the effectiveness of the proposed methods. 展开更多
关键词 networked control systems (NCSS) QUANTIZATION time-varying delays time-varying sampling guaranteed cost control
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Analyses of noncommensurate sampling used in high-precision regenerative pseudo-noise ranging systems 被引量:3
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作者 徐兆斌 金小军 +1 位作者 张朝杰 金仲和 《Journal of Central South University》 SCIE EI CAS 2014年第3期963-969,共7页
A high-precision pseudo-noise ranging system is often required in satellite-formation missions. But in an actual PN ranging system, digital signal processing limits the ranging accuracy, only level up with meter-scale... A high-precision pseudo-noise ranging system is often required in satellite-formation missions. But in an actual PN ranging system, digital signal processing limits the ranging accuracy, only level up with meter-scale. Using non-integer chip to sample time ratio, noncommensurate sampling was seen as an effective solution to cope with the drawback of digital effects. However, researchers only paid attention to selecting specific ratios or giving a simulation model to verify the effectiveness of the noncommensurate ratios. A qualitative analysis model is proposed to characterize the relationship between the range accuracy and the noncommensurate sampling parameters. Moreover, a method is also presented which can be used to choose the noncommensurate ratio and the correlation length to get higher phase delay distinguishability and lower range jitter. The simulation results indicate the correctness of our analyses and the optimal ranging accuracy can be up to centimeter-level with the proposed approach. 展开更多
关键词 regenerative pseudo-noise (PN) ranging system range jitter phase delay distinguishability noncommensurate sampling correlation length
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Iterative Learning Fault Diagnosis Algorithm for Non-uniform Sampling Hybrid System 被引量:2
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作者 Hongfeng Tao Dapeng Chen Huizhong Yang 《IEEE/CAA Journal of Automatica Sinica》 SCIE EI CSCD 2017年第3期534-542,共9页
For a class of non-uniform output sampling hybrid system with actuator faults and bounded disturbances,an iterative learning fault diagnosis algorithm is proposed.Firstly,in order to measure the impact of fault on sys... For a class of non-uniform output sampling hybrid system with actuator faults and bounded disturbances,an iterative learning fault diagnosis algorithm is proposed.Firstly,in order to measure the impact of fault on system between every consecutive output sampling instants,the actual fault function is transformed to obtain an equivalent fault model by using the integral mean value theorem,then the non-uniform sampling hybrid system is converted to continuous systems with timevarying delay based on the output delay method.Afterwards,an observer-based fault diagnosis filter with virtual fault is designed to estimate the equivalent fault,and the iterative learning regulation algorithm is chosen to update the virtual fault repeatedly to make it approximate the actual equivalent fault after some iterative learning trials,so the algorithm can detect and estimate the system faults adaptively.Simulation results of an electro-mechanical control system model with different types of faults illustrate the feasibility and effectiveness of this algorithm. 展开更多
关键词 Equivalent fault model fault diagnosis iterative learning algorithm non-uniform sampling hybrid system virtual fault
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Prediction of snow water equivalent using artificial neural network and adaptive neuro-fuzzy inference system with two sampling schemes in semi-arid region of Iran 被引量:1
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作者 Hojat GHANJKHANLO Mehdi VAFAKHAH +1 位作者 Hossein ZEINIVAND Ali FATHZADEH 《Journal of Mountain Science》 SCIE CSCD 2020年第7期1712-1723,共12页
Direct measurement of snow water equivalent(SWE)in snow-dominated mountainous areas is difficult,thus its prediction is essential for water resources management in such areas.In addition,because of nonlinear trend of ... Direct measurement of snow water equivalent(SWE)in snow-dominated mountainous areas is difficult,thus its prediction is essential for water resources management in such areas.In addition,because of nonlinear trend of snow spatial distribution and the multiple influencing factors concerning the SWE spatial distribution,statistical models are not usually able to present acceptable results.Therefore,applicable methods that are able to predict nonlinear trends are necessary.In this research,to predict SWE,the Sohrevard Watershed located in northwest of Iran was selected as the case study.Database was collected,and the required maps were derived.Snow depth(SD)at 150 points with two sampling patterns including systematic random sampling and Latin hypercube sampling(LHS),and snow density at 18 points were randomly measured,and then SWE was calculated.SWE was predicted using artificial neural network(ANN),adaptive neuro-fuzzy inference system(ANFIS)and regression methods.The results showed that the performance of ANN and ANFIS models with two sampling patterns were observed better than the regression method.Moreover,based on most of the efficiency criteria,the efficiency of ANN,ANFIS and regression methods under LHS pattern were observed higher than the systematic random sampling pattern.However,there were no significant differences between the two methods of ANN and ANFIS in SWE prediction.Data of both two sampling patterns had the highest sensitivity to the elevation.In addition,the LHS and the systematic random sampling patterns had the least sensitivity to the profile curvature and plan curvature,respectively. 展开更多
关键词 ANFIS ANN Latin hypercube sampling systematic random sampling Snow water equivalent Snow depth
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IMPROVED STRATIFIED SAMPLING MONTE CARLO METHOD TO ANALYZE RELIABILITY OF STRUCTURAL SYSTEMS 被引量:1
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作者 Li Qiang Feng Yuansheng(Department Of Aircraft Engineering, Northwestern PolytechnIcal University, XI’an, China, 710072) 《Chinese Journal of Aeronautics》 SCIE EI CAS CSCD 1996年第1期13-20,共8页
A stratified sampling Monte Carlo method to analyze the reliability of structural systems is presented. Introducing a small exploratory simulation, this method overcomes the difficulties for getting the systematic sam... A stratified sampling Monte Carlo method to analyze the reliability of structural systems is presented. Introducing a small exploratory simulation, this method overcomes the difficulties for getting the systematic sampling probability of all the strata. Several useful and efficient stratification methods are given and the strategies of stratification and simulation are studied. A general conclusion has been presented corresponding to actual engineering structures. The strict theoretical proof has been given,and it is especially effective to solve probabilistic integration. Statistic error of evaluating failure probability is reduced obviously. Especially in highly non-linear and nonreonvex problems, it is more accurate than other methods. Compared with other variance reduction techniques, this method can obtain a more obvious variance reduction and an increased sampling efficiency. Moreover, without strict limiting condition, it is convenient to use. This method is especially suitable to solve the reliability problem of structural systems with multiple failure modes and highly non-linear safety margin equations. 展开更多
关键词 structural reliability STRATA sampling Monte Carlo method
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Tunable compact asynchronous optical sampling system using Er-doped fiber laser 被引量:1
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作者 Zilin Zhao Daping Luo +7 位作者 Yang Liu Zejiang Deng Lian Zhou Gehui Xie Chenglin Gu Yanzhao Yang BinWu Wenxue Li 《High Power Laser Science and Engineering》 SCIE EI CAS CSCD 2023年第2期110-116,共7页
We report a compact,tunable,self-starting,all-fiber laser-based asynchronous optical sampling(ASOPS)system.Two Er-doped fiber oscillators were used as the pulsed-laser source,whose repetition rate could be set at 100 ... We report a compact,tunable,self-starting,all-fiber laser-based asynchronous optical sampling(ASOPS)system.Two Er-doped fiber oscillators were used as the pulsed-laser source,whose repetition rate could be set at 100 MHz with a tuning range of 1.25 MHz through a fiber delay line.By employing phase-locked and temperature control loops,the repetition rate offset of the two lasers was stabilized with 7.13×10^(−11)fractional instability at an average time of 1 s.Its capabilities in the terahertz regime were demonstrated by terahertz time-domain spectroscopy,achieving a spectral bandwidth of 3 THz with a dynamic range of 30 dB.The large range of repetition rate adjustment in our ASOPS system has the potential to be a powerful tool in the terahertz regime. 展开更多
关键词 asynchronous optical sampling mode-locked fiber laser terahertz time-domain spectroscopy
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Multiple-impairment monitoring for optical duobinary system based on delay-tap asynchronous sampling 被引量:1
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作者 赖俊森 杨爱英 孙雨南 《Journal of Beijing Institute of Technology》 EI CAS 2013年第2期246-249,共4页
A technique using artificial neural networks trained with parameters derived from delay tap plots for optical performance monitoring in 40 Gbit/s duobinary system is demonstrated. Firstly, the optical signal is delay ... A technique using artificial neural networks trained with parameters derived from delay tap plots for optical performance monitoring in 40 Gbit/s duobinary system is demonstrated. Firstly, the optical signal is delay tap sampled to obtain two-dimensional histogram, known as delay tap plots. Secondly, the features of delay tap plots are extracted to train the feed forward, three-layer preceptor structure artificial neural networks. Finally, the outputs of trained neural network are used to monitor optical duobinary signal impairments. Simulation of optical signal noise ratio ( OSNR), chromatic dispersion (CD), and differential group delay (DGD) monitoring in 40 Gbit/s optical duo- binary system is presented. The proposed monitoring scheme can accurately identify simultaneous impairments without requiring synchronous sampling or data clock recovery. The proposed technique is simple, cost-effective and suitable for in-service distributed OPM. 展开更多
关键词 optical performance monitoring (OPM) duobinary modulation delay tap sampling
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Optical sampling system using periodically-poled lithium niobate waveguide and nonlinear polarization rotation mode-locked fiber laser 被引量:2
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作者 Jian LI Aiying YANG +2 位作者 Lin ZUO Junsen LAI Yunan SUN 《Frontiers of Optoelectronics》 2012年第2期208-213,共6页
A novel design of optical sampling system has been developed by using sum-frequency generation (SFG) in a periodically-poled lithium niobate (PPLN) waveguide and using passive mode-locked fiber laser pulses as opt... A novel design of optical sampling system has been developed by using sum-frequency generation (SFG) in a periodically-poled lithium niobate (PPLN) waveguide and using passive mode-locked fiber laser pulses as optical sampling pulses. The system achieved high temporal resolution and high sensitivity using a 30 mm length PPLN with quasi phase match period of 19.3 μm and 151 fs sampling pulses which were generated by passive modelock fiber laser based on nonlinear polarization rotation (NPR). Clear eye-diagram of 10 Gbit/s non-return-to-zeros (NRZ) pseudorandom binary sequence (PRBS) optical signal were successfully reconstructed by this system. 展开更多
关键词 periodically-poled lithium niobate (PPLN) optical sampling nonlinear polarization rotation (NPR)fiber laser sum-fi'equency generation (SFG)
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Stochastic bounded consensus tracking of leader-follower multi-agent systems with measurement noises based on sampled data with general sampling delay 被引量:2
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作者 吴治海 彭力 +1 位作者 谢林柏 闻继伟 《Chinese Physics B》 SCIE EI CAS CSCD 2013年第12期555-562,共8页
In this paper we provide a unified framework for consensus tracking of leader-follower multi-agent systems with measurement noises based on sampled data with a general sampling delay. First, a stochastic bounded conse... In this paper we provide a unified framework for consensus tracking of leader-follower multi-agent systems with measurement noises based on sampled data with a general sampling delay. First, a stochastic bounded consensus tracking protocol based on sampled data with a general sampling delay is presented by employing the delay decomposition technique. Then, necessary and sufficient conditions are derived for guaranteeing leader-follower multi-agent systems with measurement noises and a time-varying reference state to achieve mean square bounded consensus tracking. The obtained results cover no sampling delay, a small sampling delay and a large sampling delay as three special cases. Last, simulations are provided to demonstrate the effectiveness of the theoretical results. 展开更多
关键词 leader-follower multi-agent systems stochastic bounded consensus tracking measurement noises general sampling delay
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High Performance Compressed Sampling for OFDM-UWB Systems 被引量:1
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作者 Lijun Ge Hua Zhang +1 位作者 Hui Guo Hong Wu 《China Communications》 SCIE CSCD 2017年第3期75-86,共12页
In order to solve the problem of high-speed sampling in OFDM based ultra wide band(UWB) systems, this paper first gives analysis on the applicability of existing compressed sampling methods. Then, on the basis of an e... In order to solve the problem of high-speed sampling in OFDM based ultra wide band(UWB) systems, this paper first gives analysis on the applicability of existing compressed sampling methods. Then, on the basis of an established segmented observation model, it presents an optimized parallel segmented compressed sampling(OPSCS) scheme based on Hadamard matrix. The orthogonal Hadamard matrix is adopted to construct the segmented measurement matrix with any dimensions, thus orthogonal or quasi-orthogonal multiplex observation sequences are obtained, and the restricted isometry property is improved. The optimized orthogonal matching pursuit algorithm is also used for the known sparsity avoiding iterative operation. Researches show that the proposed method can effectively reduce the sampling rate in OFDM-UWB systems, and also has a good ability of noise resisting that it achieves a high system performance better than the existing schemes of compressed sampling and even Nyquist rate sampling. 展开更多
关键词 ultra wide band OFDM compressed sampling observation sequence hadamard matrix OMP
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How do the landslide and non-landslide sampling strategies impact landslide susceptibility assessment? d A catchment-scale case study from China 被引量:2
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作者 Zizheng Guo Bixia Tian +2 位作者 Yuhang Zhu Jun He Taili Zhang 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2024年第3期877-894,共18页
The aim of this study is to investigate the impacts of the sampling strategy of landslide and non-landslide on the performance of landslide susceptibility assessment(LSA).The study area is the Feiyun catchment in Wenz... The aim of this study is to investigate the impacts of the sampling strategy of landslide and non-landslide on the performance of landslide susceptibility assessment(LSA).The study area is the Feiyun catchment in Wenzhou City,Southeast China.Two types of landslides samples,combined with seven non-landslide sampling strategies,resulted in a total of 14 scenarios.The corresponding landslide susceptibility map(LSM)for each scenario was generated using the random forest model.The receiver operating characteristic(ROC)curve and statistical indicators were calculated and used to assess the impact of the dataset sampling strategy.The results showed that higher accuracies were achieved when using the landslide core as positive samples,combined with non-landslide sampling from the very low zone or buffer zone.The results reveal the influence of landslide and non-landslide sampling strategies on the accuracy of LSA,which provides a reference for subsequent researchers aiming to obtain a more reasonable LSM. 展开更多
关键词 Landslide susceptibility sampling strategy Machine learning Random forest China
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Comparison of the local pivotal method and systematic sampling for national forest inventories
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作者 Minna Räty Mikko Kuronen +3 位作者 Mari Myllymäki Annika Kangas Kai Mäkisara Juha Heikkinen 《Forest Ecosystems》 SCIE CSCD 2020年第4期716-732,共17页
Background:The local pivotal method(LPM)utilizing auxiliary data in sample selection has recently been proposed as a sampling method for national forest inventories(NFIs).Its performance compared to simple random samp... Background:The local pivotal method(LPM)utilizing auxiliary data in sample selection has recently been proposed as a sampling method for national forest inventories(NFIs).Its performance compared to simple random sampling(SRS)and LPM with geographical coordinates has produced promising results in simulation studies.In this simulation study we compared all these sampling methods to systematic sampling.The LPM samples were selected solely using the coordinates(LPMxy)or,in addition to that,auxiliary remote sensing-based forest variables(RS variables).We utilized field measurement data(NFI-field)and Multi-Source NFI(MS-NFI)maps as target data,and independent MS-NFI maps as auxiliary data.The designs were compared using relative efficiency(RE);a ratio of mean squared errors of the reference sampling design against the studied design.Applying a method in NFI also requires a proven estimator for the variance.Therefore,three different variance estimators were evaluated against the empirical variance of replications:1)an estimator corresponding to SRS;2)a Grafström-Schelin estimator repurposed for LPM;and 3)a Matérn estimator applied in the Finnish NFI for systematic sampling design.Results:The LPMxy was nearly comparable with the systematic design for the most target variables.The REs of the LPM designs utilizing auxiliary data compared to the systematic design varied between 0.74–1.18,according to the studied target variable.The SRS estimator for variance was expectedly the most biased and conservative estimator.Similarly,the Grafström-Schelin estimator gave overestimates in the case of LPMxy.When the RS variables were utilized as auxiliary data,the Grafström-Schelin estimates tended to underestimate the empirical variance.In systematic sampling the Matérn and Grafström-Schelin estimators performed for practical purposes equally.Conclusions:LPM optimized for a specific variable tended to be more efficient than systematic sampling,but all of the considered LPM designs were less efficient than the systematic sampling design for some target variables.The Grafström-Schelin estimator could be used as such with LPMxy or instead of the Matérn estimator in systematic sampling.Further studies of the variance estimators are needed if other auxiliary variables are to be used in LPM. 展开更多
关键词 Auxiliary data Bias Local pivotal method Matérn estimator National forest inventory sampling efficiency Simple random sampling Spatially balanced sampling systematic sampling Variance
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Research on a Monte Carlo global variance reduction method based on an automatic importance sampling method 被引量:1
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作者 Yi-Sheng Hao Zhen Wu +3 位作者 Shen-Shen Gao Rui Qiu Hui Zhang Jun-Li Li 《Nuclear Science and Techniques》 SCIE EI CAS CSCD 2024年第5期200-215,共16页
Global variance reduction is a bottleneck in Monte Carlo shielding calculations.The global variance reduction problem requires that the statistical error of the entire space is uniform.This study proposed a grid-AIS m... Global variance reduction is a bottleneck in Monte Carlo shielding calculations.The global variance reduction problem requires that the statistical error of the entire space is uniform.This study proposed a grid-AIS method for the global variance reduction problem based on the AIS method,which was implemented in the Monte Carlo program MCShield.The proposed method was validated using the VENUS-Ⅲ international benchmark problem and a self-shielding calculation example.The results from the VENUS-Ⅲ benchmark problem showed that the grid-AIS method achieved a significant reduction in the variance of the statistical errors of the MESH grids,decreasing from 1.08×10^(-2) to 3.84×10^(-3),representing a 64.00% reduction.This demonstrates that the grid-AIS method is effective in addressing global issues.The results of the selfshielding calculation demonstrate that the grid-AIS method produced accurate computational results.Moreover,the grid-AIS method exhibited a computational efficiency approximately one order of magnitude higher than that of the AIS method and approximately two orders of magnitude higher than that of the conventional Monte Carlo method. 展开更多
关键词 Monte Carlo Global variance reduction Reactor shielding Automatic importance sampling
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Study on Self-adaptive Systematic Double Sampling method for Self-similar Network Traffic
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作者 Liu Yuanzhen Liu Yuan Li Xiaohang 《China Communications》 SCIE CSCD 2007年第2期86-89,共4页
This paper proposes anew variation of systematic sampling, called Self-Adaptive Systematic Double Sampling(SSDS). This algorithm can fully consider the self-similar and heavy-tailed distribution characteristics of net... This paper proposes anew variation of systematic sampling, called Self-Adaptive Systematic Double Sampling(SSDS). This algorithm can fully consider the self-similar and heavy-tailed distribution characteristics of network traffic and estimate Hurst parameter correctly.The experiments on real Internet traces indicate,compared with traditional sampling methods,the new method advances the accuracy and practicability of the sampling measuring system obviously,and can achieve simplicity,adaptability and controllability of resource consumption. 展开更多
关键词 SELF-SIMILARITY Hurst PARAMETER DOUBLE sampling
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