期刊文献+
共找到5,067篇文章
< 1 2 250 >
每页显示 20 50 100
Parameter identification of magnetic levitation system based on modulation function method
1
作者 Tingchen Du Xueling Fan Sheng Feng 《Control Theory and Technology》 2025年第4期602-617,共16页
A novel parameter identification method for magnetic levitation bearing rotor systems is proposed,based on the modulation function method.The fundamental principle of the modulation function method for parameter ident... A novel parameter identification method for magnetic levitation bearing rotor systems is proposed,based on the modulation function method.The fundamental principle of the modulation function method for parameter identification is derived on the basis of the characteristics of the modulation function.The transformation of the differential equation model of a continuous system into a general algebraic equation model is effectively achieved,thereby avoiding the influence of errors introduced by the initial value and differential derivation of the system.Modulation function method parameter identification models have been established for single-degree-of-freedom and multi-degree-of-freedom magnetic levitation bearing rotor systems.The influence of different parameters of Hartley modulation function on the accuracy of system parameter identification has been investigated,thus providing a basis for the design of Hartley modulation function parameters.Simulation and experimental results demonstrate that the modulation function method can effectively identify system parameters despite the presence of system noise. 展开更多
关键词 Modulation function method Hartley modulation function Magnetic levitation system parameter identification
原文传递
Transient analysis of functionally graded curved shells using a nonuniform shape parameter integrated radial basis function approach
2
作者 Vay Siu Lo Andrzej Katunin Thien Tich Truong 《Theoretical & Applied Mechanics Letters》 2025年第3期296-308,共13页
In this study,an improved integrated radial basis function with nonuniform shape parameter is introduced.The proposed shape parameter varies in each support domain and is defined byθ=1/d_(max),where d_(max)is the max... In this study,an improved integrated radial basis function with nonuniform shape parameter is introduced.The proposed shape parameter varies in each support domain and is defined byθ=1/d_(max),where d_(max)is the maximum distance of any pair of nodes in the support domain.The proposed method is verified and shows good performance.The results are stable and accurate with any number of nodes and an arbitrary nodal distribution.Notably,the support domain should be large enough to obtain accurate results.This method is then applied for transient analysis of curved shell structures made from functionally graded materials with complex geometries.Through several numerical examples,the accuracy of the proposed approach is demonstrated and discussed.Additionally,the influence of various factors on the dynamic behavior of the structures,including the power-law index,different materials,loading conditions,and geometrical parameters of the structures,was investigated. 展开更多
关键词 Integrated radial basis function Shape parameter functionally graded material Curved shell Transient analysis
在线阅读 下载PDF
Rules of acupoint and parameter selection for electrostimulation in treatment of functional dyspepsia based on bibliometrics
3
作者 Dan WANG Pei-jing RONG 《World Journal of Acupuncture-Moxibustion》 2025年第3期232-237,共6页
Objective To analyze the electrostimulation parameters and acupoint prescriptions for treatment of functional dyspepsia(FD)based on bibliometric methods.Methods The relevant papers were searched from PubMed,Web of Sci... Objective To analyze the electrostimulation parameters and acupoint prescriptions for treatment of functional dyspepsia(FD)based on bibliometric methods.Methods The relevant papers were searched from PubMed,Web of Science,Embase,China National Knowledge Infrastructure(CNKI),Wanfang Data,China Science and Technology Journal Database(VIP)and China Biology Medicine disc(Sinomed),dated from January 1st,2010 to May 31st,2023.Inclusion criteria of studies:①“functional dyspepsia”and electric stimulation involved in the title or abstract;and②related to the assessment of electrostimulation therapy in clinical trials and experimental research for FD.Exclusion criteria of studies:①duplication or failure to obtain full text;②published in newspaper,presenting as research achievement,and review;③nothing related to the acupoint selection;and④nothing related to the parameters of electrostimulation.Using Excel 2019 and VOSviewer software,acupoint association and the parameters of electrostimulation were analyzed and graphed.Results A total of 181 eligible articles were screened.Statistical analysis revealed that the most frequently targeted acupoints for electrostimulation in functional dyspepsia(FD)were Zusanli(ST36),Taichong(LR3),and Neiguan(PC6),while the most commonly utilized auricular point was Erjia(CO,concha zone).The acupoint group demonstrating the strongest association consisted of ST36,LR3,Zhongwan(CV12),and PC6,which constituted the primary prescription for electrostimulation in FD.The optimal parameters for electrostimulation were identified as a disperse-dense wave,a frequency of 2/100 Hz,and an intensity of 1 mA.The acupoints ST36,LR3,and PC6 are the most prevalent for electrostimulation in FD,with CO being the most common auricular point.The optimal electrostimulation parameters are a disperse-dense wave,a frequency of 2/100 Hz,and an intensity of 1 mA.Conclusion The acupoints ST36,LR3,and PC6 are the most prevalent for electrostimulation in FD,with CO being the most common auricular point.The optimal electrostimulation parameters are a disperse-dense wave,a frequency of 2/100 Hz,and an intensity of 1 mA. 展开更多
关键词 Acupoint electrostimualtion function dyspepsia Stimulation of the vagus nerve parameters
原文传递
Effects of sleep bruxism on functional and occlusal parameters:a prospective controlled investigation 被引量:5
4
作者 Michelle Alicia Ommerborn Maria Giraki +5 位作者 Christine Schneider Lars Michael Fuck Jrg Handschel Matthias Franz Wolfgang Hans-Michael Raab Ralf Schfer 《International Journal of Oral Science》 SCIE CAS CSCD 2012年第3期141-145,共5页
This study was conducted to verify the results of a preceding retrospective pilot study by means of a prospective controlled investigation including a larger sample size. Therefore, the aim of this clinical investigat... This study was conducted to verify the results of a preceding retrospective pilot study by means of a prospective controlled investigation including a larger sample size. Therefore, the aim of this clinical investigation was to analyze the relationship between sleep bruxism and several functional and occlusal parameters. The null hypothesis of this study was that there would be no differences among sleep bruxism subjects and non-sleep bruxism controls regarding several functional and occlusal parameters. Fifty-eight sleep bruxism subjects and 31 controls participated in this study. The diagnosis sleep bruxism was based on clinical criteria of the American Academy of Sleep Medicine. Sixteen functional and occlusal parameters were recorded clinically or from dental study casts. Similar to the recently published retrospective pilot study, with a mean slide of 0.77 mm (s.d., 0.69 mm) in the sleep bruxism group and a mean slide of 0.4 mm (s.d., 0.57 mm) in the control group, the evaluation of the mean comparison between the two groups demonstrated a larger slide from centric occlusion to maximum intercuspation in sleep bruxism subjects (Mann-Whitney U-test; P=O.O08). However, following Bonferroni adjustment, none of the 16 occlusal and functional variables differed significantly between the sleep bruxism subjects and the non-sleep bruxism controls. The present study shows that the occlusal and functional parameters evaluated do not differ between sleep bruxism subjects and non-sleep bruxism subjects. However, as the literature reveals a possible association between bruxism and certain subgroups of temporomandibular disorders, it appears advisable to incorporate the individual adaptive caoacitv of the stomatognathic svstem into future investigations. 展开更多
关键词 dental occlusion functional parameters prospective study sleep bruxism
暂未订购
LAD PARAMETER ESTIMATION of SaS BASED on SAMPLE CHARACTERISTIC FUNCTION
5
作者 陈高波 《科技信息》 2010年第25期I0028-I0028,I0027,共2页
Parameter estimation to alpha stable distribution is difficult for without a explicit probability density function. On the base of sample characteristic function,an iterative LAD parameter estimation algorithm for SaS... Parameter estimation to alpha stable distribution is difficult for without a explicit probability density function. On the base of sample characteristic function,an iterative LAD parameter estimation algorithm for SaS is discussed. The example illustrates that the algorithm is feasible and efficient. 展开更多
关键词 概率 密度函数 计算方法 迭代参数
在线阅读 下载PDF
Comparison Between Radial Basis Function Neural Network and Regression Model for Estimation of Rice Biophysical Parameters Using Remote Sensing 被引量:11
6
作者 YANG Xiao-Hua WANG Fu-Min +4 位作者 HUANG Jing-Feng WANG Jian-Wen WANG Ren-Chao SHEN Zhang-Quan WANG Xiu-Zhen 《Pedosphere》 SCIE CAS CSCD 2009年第2期176-188,共13页
The radial basis function (RBF) emerged as a variant of artificial neural network. Generalized regression neural network (GRNN) is one type of RBF, and its principal advantages are that it can quickly learn and ra... The radial basis function (RBF) emerged as a variant of artificial neural network. Generalized regression neural network (GRNN) is one type of RBF, and its principal advantages are that it can quickly learn and rapidly converge to the optimal regression surface with large number of data sets. Hyperspectral reflectance (350 to 2500 nm) data were recorded at two different rice sites in two experiment fields with two cultivars, three nitrogen treatments and one plant density (45 plants m^-2). Stepwise multivariable regression model (SMR) and RBF were used to compare their predictability for the leaf area index (LAI) and green leaf chlorophyll density (GLCD) of rice based on reflectance (R) and its three different transformations, the first derivative reflectance (D1), the second derivative reflectance (D2) and the log-transformed reflectance (LOG). GRNN based on D1 was the best model for the prediction of rice LAI and CLCD. The relationships between different transformations of reflectance and rice parameters could be further improved when RBF was employed. Owing to its strong capacity for nonlinear mapping and good robustness, GRNN could maximize the sensitivity to chlorophyll content using D1. It is concluded that RBF may provide a useful exploratory and predictive tool for the estimation of rice biophysical parameters. 展开更多
关键词 biophysical parameters radial basis function regression model remote sensing RICE
在线阅读 下载PDF
The Most Probable Mechanism Function and Kinetic Parameters of Gibbsite Dissolution in NaOH 被引量:10
7
作者 鲍丽 张廷安 +5 位作者 刘燕 豆志河 吕国志 王晓民 马佳 蒋孝丽 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2010年第4期630-634,共5页
Determination of probable mechanism function and kinetic parameters is important to hydrometallurgical kinetics.In this work,the most probable mechanism function and kinetic parameters of gibbsite dissolution in NaOH ... Determination of probable mechanism function and kinetic parameters is important to hydrometallurgical kinetics.In this work,the most probable mechanism function and kinetic parameters of gibbsite dissolution in NaOH solution are studied.The sample,the mixture of synthetic gibbsite and sodium hydroxide solution,was scanned in high-pressure differential scanning calorimetry(DSC) equipment with the heating rate of 10 K·min-1. Integral equation and differential equation of non-isothermal kinetics were solved to fit the data related to DSC curve.According to the calculation results,the most probable mechanism function for pure synthetic gibbsite dissolution in sodium hydroxide solution is presented based on the optimum procedure in the database of the mechanism function.The apparent activation energy obtained is(75±1) kJ·mol-1,the frequency factor is 10 8±1mol·s-1,and the reaction is a second order reaction. 展开更多
关键词 GIBBSITE kinetic parameter mechanism function integral equation differential equation
在线阅读 下载PDF
Synthetically quantitative evaluation function of characteristic parameters on CO_2 arc welding process 被引量:4
8
作者 俞建荣 蒋力培 +2 位作者 史耀武 孙振国 王军波 《China Welding》 EI CAS 2001年第1期19-26,共8页
The statistical probability and their variation regularity of the measurable characteristic parameters in the CO 2 arc welding droplet short circuiting transfer process have been studied. The statistical analysis sh... The statistical probability and their variation regularity of the measurable characteristic parameters in the CO 2 arc welding droplet short circuiting transfer process have been studied. The statistical analysis shows that the sensitivity of each characteristic parameter with regard to the variation of the short circuiting transfer process is different. The sensitivity of 4 kinds among these characteristic parameters is more intense than that of the short circuiting transfer frequency. In order to take account of the synthetic influence of these characteristic parameters, by means of the characteristic parameters synthetic value, a quantitative evaluation function is built up to describe and evaluate the short circuiting transfer process of CO 2 arc welding in real time. The testing shows that the evaluation function can give a suitable synthetic valuation for the short circuiting transfer process with a variety of welding variables. 展开更多
关键词 CO 2 arc welding process characteristic parameters quantitative evaluation function
在线阅读 下载PDF
Plasma brain natriuretic peptide, platelet parameters, and cardiopulmonary function in chronic obstructive pulmonary disease 被引量:11
9
作者 Hai-Jian Guo Feng Jiang +2 位作者 Chu Chen Jia-Yu Shi Ya-Wen Zhao 《World Journal of Clinical Cases》 SCIE 2021年第36期11165-11172,共8页
BACKGROUND Chronic obstructive pulmonary disease(COPD)is a chronic respiratory disease with worldwide occurrence and high disability and mortality rate.It occurs mostly in the elderly population with pulmonary heart d... BACKGROUND Chronic obstructive pulmonary disease(COPD)is a chronic respiratory disease with worldwide occurrence and high disability and mortality rate.It occurs mostly in the elderly population with pulmonary heart disease,type II respiratory failure,and other serious complications.AIM To investigate the correlation of plasma brain natriuretic peptide(BNP)and platelet parameters with cardiac function and pulmonary hypertension in patients with COPD and pulmonary heart disease.METHODS From June 2016 to June 2019,52 patients with COPD-pulmonary heart disease(pulmonary heart disease group),30 patients with COPD(COPD group),and 30 healthy individuals(control group)in our hospital were enrolled in the study.The pulmonary heart disease group was further divided into subgroups according to cardiac function classification and pulmonary artery pressure.Plasma BNP and platelet parameters were estimated and compared among each group and subgroup.The correlation of plasma BNP and platelet parameters with cardiac function classification and pulmonary artery pressure was then analyzed.RESULTS In the pulmonary heart disease group,the COPD group,and the control group,the levels of plasma BNP,platelet distribution width(PDW),and mean platelet volume(MPV)showed a decreasing trend(P<0.05),while an increasing trend was found in platelet count(PLT)and plateletcrit(PCT)levels among the three groups(P<0.05).In the pulmonary hypertension mild,moderate,and severe subgroups,the levels of plasma BNP,PDW,and MPV showed an increasing trend(P<0.05),while a decreasing trend was observed in PLT levels(P<0.05);however,PCT levels showed no significant difference among the three subgroups(P>0.05).In the cardiac function grade I,II,III,and IV subgroups,the levels of plasma BNP,PDW,and MPV showed an increasing trend(P<0.05),while a decreasing trend was noted in PLT and PCT levels among the four subgroups(P<0.05).Correlation analysis showed that the levels of plasma BNP,PDW,and MPV in patients with pulmonary heart disease were positively correlated with their pulmonary artery pressure(P<0.05),while PLT was negatively correlated with their pulmonary artery pressure(P<0.05).Moreover,plasma BNP,PDW,and MPV levels were positively correlated with cardiac function grade(P<0.05)of these patients,while PLT and PCT levels were negatively correlated with their cardiac function grade(P<0.05).CONCLUSION Plasma BNP and PLT parameters are significantly correlated with the cardiac function and pulmonary hypertension in patients with COPD and pulmonary heart disease,indicating that these parameters have high clinical relevance in reflecting the health condition of these patients and for guiding their treatment. 展开更多
关键词 Chronic obstructive pulmonary disease Pulmonary heart disease Plasma brain natriuretic peptide Platelet parameter Cardiac function Pulmonary hypertension Correlation analysis
暂未订购
Interaction between systemic iron parameters and left ventricular structure and function in the preserved ejection fraction population:a two-sample bidirectional Mendelian randomization study 被引量:1
10
作者 Xiong-Bin MA Yong-Ming LIU +1 位作者 Yan-Lin LV Lin QIAN 《Journal of Geriatric Cardiology》 SCIE CAS CSCD 2024年第1期64-80,共17页
BACKGROUND Left ventricular(LV)remodeling and diastolic function in people with heart failure(HF)are correlated with iron status;however,the causality is uncertain.This Mendelian randomization(MR)study investigated th... BACKGROUND Left ventricular(LV)remodeling and diastolic function in people with heart failure(HF)are correlated with iron status;however,the causality is uncertain.This Mendelian randomization(MR)study investigated the bidirectional causal relationship between systemic iron parameters and LV structure and function in a preserved ejection fraction population.METHODS Transferrin saturation(TSAT),total iron binding capacity(TIBC),and serum iron and ferritin levels were extracted as instrumental variables for iron parameters from meta-analyses of public genome-wide association studies.Individuals without myocardial infarction history,HF,or LV ejection fraction(LVEF)<50%(n=16,923)in the UK Biobank Cardiovascular Magnetic Resonance Imaging Study constituted the outcome dataset.The dataset included LV end-diastolic volume,LV endsystolic volume,LV mass(LVM),and LVM-to-end-diastolic volume ratio(LVMVR).We used a two-sample bidirectional MR study with inverse variance weighting(IVW)as the primary analysis method and estimation methods using different algorithms to improve the robustness of the results.RESULTS In the IVW analysis,one standard deviation(SD)increased in TSAT significantly correlated with decreased LVMVR(β=-0.1365;95%confidence interval[CI]:-0.2092 to-0.0638;P=0.0002)after Bonferroni adjustment.Conversely,no significant relationships were observed between other iron and LV parameters.After Bonferroni correction,reverse MR analysis showed that one SD increase in LVEF significantly correlated with decreased TSAT(β=-0.0699;95%CI:-0.1087 to-0.0311;P=0.0004).No heterogeneity or pleiotropic effects evidence was observed in the analysis.CONCLUSIONS We demonstrated a causal relationship between TSAT and LV remodeling and function in a preserved ejection fraction population. 展开更多
关键词 FRACTION function parameterS
暂未订购
MODAL PARAMETERS EXTRACTION WITH CROSS CORRELATION FUNCTION AND CROSS POWER SPECTRUM UNDER UNKNOWN EXCITATION 被引量:1
11
作者 郑敏 申凡 +1 位作者 陈怀海 鲍明 《Chinese Journal of Aeronautics》 SCIE EI CSCD 2000年第1期19-23,共5页
In most of real operational conditions only response data are measurable while the actual excitations are unknown, so modal parameter must be extracted only from responses. This paper gives a theoretical formulation f... In most of real operational conditions only response data are measurable while the actual excitations are unknown, so modal parameter must be extracted only from responses. This paper gives a theoretical formulation for the cross-correlation functions and cross-power spectra between the outputs under the assumption of white-noise excitation. It widens the field of modal analysis under ambient excitation because many classical methods by impulse response functions or frequency response functions can be used easily for modal analysis under unknown excitation. The Polyreference Complex Exponential method and Eigensystem Realization Algorithm using cross-correlation functions in time domain and Orthogonal Polynomial method using cross-power spectra in frequency domain are applied to a steel frame to extract modal parameters under operational conditions. The modal properties of the steel frame from these three methods are compared with those from frequency response functions analysis. The results show that the modal analysis method using cross-correlation functions or cross-power spectra presented in this paper can extract modal parameters efficiently under unknown excitation. 展开更多
关键词 Algorithms Correlation methods Dynamic response Eigenvalues and eigenfunctions Frequency domain analysis functions Modal analysis parameter estimation Structural frames Time domain analysis Vibrations (mechanical) White noise
在线阅读 下载PDF
Rheological Behaviour for Polymer Melts and Concentrated SolutionsPart Ⅱ: Material Function with Nagai Chain Constraints and Determination of Their Parameters from Flow Curves 被引量:3
12
作者 Mingshi SONG Sizhu WU and Xiuyun DU(Research Institute of Polymeric Materials, Beijing University of Chemical Technology, Beijing, 100029, China) 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 1995年第2期141-152,共12页
An integral constitutive equation and a set of material functions for describing the strain history of polymer melts were formulated in terms of the Cauchy-Green and Finger tensors. A simple memory function and the de... An integral constitutive equation and a set of material functions for describing the strain history of polymer melts were formulated in terms of the Cauchy-Green and Finger tensors. A simple memory function and the dependence of ηo and τt on M3.4 were derived from the theory of non-linear viscoelasticity with constraints of entanglements for polymer melts and substituted into the Oldroye-Walters-Fredickson constitutive equation. An integral constitutive equation for polymer melts was consequently obtained. Some material functions of the constitutive equation related to certain 'test flow' are examined as follows : (1) simple steady shear flow; (2) steady elongation flow; (3) small-amplitude oscillatory shear flow; (4) stress growth upon the inception of steady shear elongation flow; (5) stress relaxation (modulus and compllance). These theoretical relations for simple steady shear flow were compared with experimental data from our laboratory and references for various polymer melts and concentrated solutions. A good agreement between the theory and experiment was achieved. 展开更多
关键词 LDPE Material function with Nagai Chain Constraints and Determination of Their parameters from Flow Curves Rheological Behaviour for Polymer Melts and Concentrated SolutionsPart Flow GR
在线阅读 下载PDF
Measurement of Optical Fiber Geometry Parameters with Bessel Function Fitting Method 被引量:1
13
作者 Yiming Li Huazhong Xiang +3 位作者 Jiankun Tu Gang Zheng Minghui Chen Bin Jiang 《Journal of Harbin Institute of Technology(New Series)》 EI CAS 2021年第2期74-81,共8页
Geometry parameters of optical fiber are crucial in evaluating the quality of the optical fiber.Near⁃field light distribution method is recommended in GB15972.20-2008 for the measurement of geometry parameters.To dist... Geometry parameters of optical fiber are crucial in evaluating the quality of the optical fiber.Near⁃field light distribution method is recommended in GB15972.20-2008 for the measurement of geometry parameters.To distinguish the boundary between fiber core and cladding,it is necessary to illuminate the fiber.The end face of the core is a bright spot with unclear edge,so the true edge of the core and the cladding cannot be accurately judged.A method is proposed in this paper to measure the geometry parameters of optical fiber by Bessel function fitting.Theoretically,the solution to the electromagnetic vector of mode field satisfies Bessel function,and the boundary between the core and the cladding can be precisely extracted by Bessel function fitting.Edges of the fiber were fitted by elliptical curves,and the geometry parameters of the fibers could be calculated.Results show that the maximum deviations of the diameters and the average differences of the fibers were decreased under normal and abnormal conditions respectively.The proposed method is an efficient way to obtain edge data and can improve the accuracy and stability of geometry parameters of optical fibers. 展开更多
关键词 geometry parameters of optical fiber Bessel function edge detect
在线阅读 下载PDF
PARAMETER IDENTIFICATION PROBLEM OF THE FRACTAL INTERPOLATION FUNCTIONS 被引量:5
14
作者 阮火军 沙震 苏维宜 《Numerical Mathematics A Journal of Chinese Universities(English Series)》 SCIE 2003年第2期205-213,共9页
Parameter identification problem is one of essential problem in order to model effectively experimental data by fractal interpolation function.In this paper,we first present an example to explain a relationship betwee... Parameter identification problem is one of essential problem in order to model effectively experimental data by fractal interpolation function.In this paper,we first present an example to explain a relationship between iteration procedure and fractal function.Then we discuss conditions that vertical scaling factors must obey in one typical case. 展开更多
关键词 分形插值函数 参数鉴定 吸引子 垂直定标因数
在线阅读 下载PDF
Influence of Processed Mustard Seed Meals on Growth and Health Parameters in Indian Major Carps
15
作者 Shivanshu Garg Himanshu Punetha +8 位作者 Anant Deogaonkar Deepshree Kumar Ashutosh Mishra AshokKumar Verma Nityanand Pandey Ranjeet Singh Saurabh Gangola Sunil Kumar Amit Mittal 《Research in Ecology》 2025年第2期93-105,共13页
The current investigation focuses on intertwined relationships of ecology and aquaculture for the benefit of farmers involved in fish farming practices.The study evaluated glucosinolate reduction in black,brown,and wh... The current investigation focuses on intertwined relationships of ecology and aquaculture for the benefit of farmers involved in fish farming practices.The study evaluated glucosinolate reduction in black,brown,and white mustard meals as fish feed ingredients for Indian Major Carps.Fish were fed with 10%mustard meal-supplemented diets in three forms:Raw(R),Anti-nutritional Rich(AR),and Anti-nutritional Lowered(AL),alongside a control group using floating feed.The three-month indoor experiment(September-November 2023)was conducted in FRP tanks with triplicate treatments.Blood analysis revealed compromised health in AR-fed carps,with reduced hemoglobin levels in rohu,catla and mrigal and elevated total leukocyte counts indicating inflammation in all the three carps studied here.Liver function was impaired in AR-fed fish,shown by increased alanine transaminase levels,highest in rohu followed by mrigal and catla.Histopathological examination of AR-fed carps liver tissue revealed necrotic spots,deformed hepatocytes,and significant vacuolation.In contrast,AL-fed fish demonstrated improved health parameters through Complete Blood Count analysis,liver function tests,and histo-pathological observations,suggesting successful reduction of anti-nutritional factors in the processed mustard meals.In near future,replacement of unprocessed seed meal with processed seed meal will lead to economic gains in fish farming. 展开更多
关键词 Biochemical parameters GLUCOSINOLATES Growth parameters Histo-Pathological Analysis Indian Major Carps Liver function Test
在线阅读 下载PDF
A methodology to simulate interior and intermediate ballistics with dynamic mesh technique and lumped parameter code
16
作者 G.Guermonprez T.Gaillard +2 位作者 J.Dupays J.Anthoine R.Demarthon 《Defence Technology(防务技术)》 2025年第7期447-464,共18页
The aim of this paper is to simulate and study the early moments of the reactive ballistics of a large caliber projectile fired from a gun,combining 0D and 2D axisymmetric Computational Fluid Dynamics(CFD)approaches.F... The aim of this paper is to simulate and study the early moments of the reactive ballistics of a large caliber projectile fired from a gun,combining 0D and 2D axisymmetric Computational Fluid Dynamics(CFD)approaches.First,the methodology is introduced with the development of an interior ballistics(IB)lumped parameter code(LPC),integrating an original image processing method for calculating the specific regression of propellant grains that compose the gun propellant.The ONERA CFD code CEDRE,equipped with a Dynamic Mesh Technique(DMT),is then used in conjunction with the developed LPC to build a dedicated methodology to calculate IB.First results obtained on the AGARD gun and 40 mm gun test cases are in a good agreement with the existing literature.CEDRE is also used to calculate inter-mediate ballistics(first milliseconds of free flight of the projectile)with a multispecies and reactive approach either starting from the gun muzzle plane or directly following IB.In the latter case,an inverse problem involving a Latin hypercube sampling method is used to find a gun propellant configuration that allows the projectile to reach a given exit velocity and base pressure when IB ends.The methodology developed in this work makes it possible to study the flame front of the intermediate flash and depressurization that occurs in a base bleed(BB)channel at the gun muzzle.Average pressure variations in the BB channel during depressurization are in good agreement with literature. 展开更多
关键词 Intermediate ballistics Interior ballistics(IB) Lumped parameter code(LPC) Form function Dynamic mesh
暂未订购
Precise calculations on spectroscopic parameters of diatomic molecules using a novel potential energy function
17
作者 于长丰 朱长军 刘代志 《Journal of Shanghai University(English Edition)》 CAS 2008年第3期210-215,共6页
A novel scheme for potential energy functions of diatomic molecules is derived using a function with phase factors. Six kinds of potential curves of common shapes are obtained by adjusting the phase factors. Spectrosc... A novel scheme for potential energy functions of diatomic molecules is derived using a function with phase factors. Six kinds of potential curves of common shapes are obtained by adjusting the phase factors. Spectroscopic parameters of the ground states for ten kinds of molecules are calculated using the potential energy functions. The results agree well with experimental data. 展开更多
关键词 potential energy function force constants spectroscopic parameters diatomic molecules
在线阅读 下载PDF
Generalized weighted functional proportional mean combining forecasting model and its method of parameter estimation
18
作者 万玉成 盛昭潮 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2004年第1期7-11,18,共6页
A new kind of combining forecasting model based on the generalized weighted functional proportional mean is proposed and the parameter estimation method of its weighting coefficients by means of the algorithm of quadr... A new kind of combining forecasting model based on the generalized weighted functional proportional mean is proposed and the parameter estimation method of its weighting coefficients by means of the algorithm of quadratic programming is given. This model has extensive representation. It is a new kind of aggregative method of group forecasting. By taking the suitable combining form of the forecasting models and seeking the optimal parameter, the optimal combining form can be obtained and the forecasting accuracy can be improved. The effectiveness of this model is demonstrated by an example. 展开更多
关键词 combining forecasting generalized weighted functional proportional mean parameter estimation quadratic programming
在线阅读 下载PDF
Unbiased parameter estimation of continuous-time system based on modulating functions with input and output white noises
19
作者 贺尚红 李旭宇 《Journal of Central South University》 SCIE EI CAS 2011年第3期773-781,共9页
An efficient unbiased estimation method is proposed for the direct identification of linear continuous-time system with noisy input and output measurements.Using the Gaussian modulating filters,by numerical integratio... An efficient unbiased estimation method is proposed for the direct identification of linear continuous-time system with noisy input and output measurements.Using the Gaussian modulating filters,by numerical integration,an equivalent discrete identification model which is parameterized with continuous-time model parameters is developed,and the parameters can be estimated by the least-squares (LS) algorithm.Even with white noises in input and output measurement data,the LS estimate is biased,and the bias is determined by the variances of noises.According to the asymptotic analysis,the relationship between bias and noise variances is derived.One equation relating to the measurement noise variances is derived through the analysis of the LS errors.Increasing the degree of denominator of the system transfer function by one,an extended model is constructed.By comparing the true value and LS estimates of the parameters between original and extended model,another equation with input and output noise variances is formulated.So,the noise variances are resolved by the set of equations,the LS bias is eliminated and the unbiased estimates of system parameters are obtained.A simulation example by comparing the standard LS with bias eliminating LS algorithm indicates that the proposed algorithm is an efficient method with noisy input and output measurements. 展开更多
关键词 continuous-time system unbiased parameter modulating functions noise
在线阅读 下载PDF
Simulation of γ spectrum-shifting based on the parameter adjustment of Gaussian function space 被引量:1
20
作者 HUANG Hongquan SHAO qiang +2 位作者 DING Weicheng FANG Fang GONG Dichen 《Nuclear Science and Techniques》 SCIE CAS CSCD 2013年第6期99-104,共6页
Based on the statistical characteristics of energy spectrum and the features of spectrum-shifting in spectrometry,the parameter adjustment method of Gaussian function space was applied in the simulation of spectrum-sh... Based on the statistical characteristics of energy spectrum and the features of spectrum-shifting in spectrometry,the parameter adjustment method of Gaussian function space was applied in the simulation of spectrum-shifting.The transient characteristics of energy spectrum were described by the Gaussian function space,and then the Gaussian function space was transferred by parameter adjustment method.Furthermore,the spectrum-shifting in measurement of energy spectrum was simulated.The applied example shows that the parameters can be adjusted flexibly by this method to meet the various requirements in simulation of energy spectrum-shifting.This method was one parameterized simulation method with good performance for the practical application. 展开更多
关键词 高斯函数 参数调整 空间仿真 基础 Γ谱 仿真应用 函数空间 模拟方法
在线阅读 下载PDF
上一页 1 2 250 下一页 到第
使用帮助 返回顶部