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Modified molecular matrix model for predicting molecular composition of naphtha' 被引量:4
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作者 Kun Wang Shiyu Li 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2017年第12期1856-1862,共7页
To improve the naphtha composition prediction model based on molecular type homologous series matrix (MTHS), this paper puts forward a novel molecular matrix to characterize the naphtha composition and the norreal d... To improve the naphtha composition prediction model based on molecular type homologous series matrix (MTHS), this paper puts forward a novel molecular matrix to characterize the naphtha composition and the norreal distribution hypothesis to better describe the molecular composition distribution within each homologous series of the molecular matrix. Through prediction calculation of eight groups of naphtha samples and eight groups of gasoline samples, it is verified that the normal distribution hypothesis is more applicable than gamma distribution hypothesis for the prediction model. According to the prediction results of the samples, the restrain range of normal distribution parameters during model computing process is summarized. With the bulk properties of naphtha samples and the value range of distribution parameters as input conditions, this study utilizes the improved novel molecular matrix to predict the composition of naphtha samples. As the results show, the novel molecular matrix can predict more detailed composition information of naphtha and improve prediction accuracy with less unknown parameters. 展开更多
关键词 MTHS molecular matrix Distribution assumption Naphtha Molecular composition Prediction model
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Ecosystem service multifunctionality of mixed conifer-broad-leaved forests under climate change and forest management based on matrix growth modelling
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作者 Xue Du Xiangdong Lei +3 位作者 Xiao He Jie Lan Hong Guo Qigang Xu 《Forest Ecosystems》 SCIE CSCD 2024年第5期743-757,共15页
Climate change and forest management are recognized as pivotal factors influencing forest ecosystem services and thus multifunctionality.However,the magnitude and the relative importance of climate change and forest m... Climate change and forest management are recognized as pivotal factors influencing forest ecosystem services and thus multifunctionality.However,the magnitude and the relative importance of climate change and forest management effects on the multifunctionality remain unclear,especially for natural mixed forests.In this study,our objective is to address this gap by utilizing simulations of climate-sensitive transition matrix growth models based on national forest inventory plot data.We evaluated the effects of seven management scenarios(combinations of various cutting methods and intensities)on the future provision of ecosystem services and multifunctionality in mixed conifer-broad-leaved forests in northeastern China,under four climate scenarios(SSP1-2.6,SSP2-4.5,SSP5-8.5,and constant climate).Provisioning,regulating,cultural,and supporting services were described by timber production,carbon storage,carbon sequestration,tree species diversity,deadwood volume,and the number of large living trees.Our findings indicated that timber production was significantly influenced by management scenarios,while tree species diversity,deadwood volume,and large living trees were impacted by both climate and management separately.Carbon storage and sequestration were notably influenced by both management and the interaction of climate and management.These findings emphasized the profound impact of forest management on ecosystem services,outweighing that of climate scenarios alone.We found no single management scenario maximized all six ecosystem service indicators.The upper story thinning by 5%intensity with 5-year interval(UST5)management strategy emerged with the highest multifunctionality,surpassing the lowest values by more than 20%across all climate scenarios.In conclusion,our results underlined the potential of climate-sensitive transition matrix growth models as a decision support tool and provided recommendations for long-term strategies for multifunctional forest management under future climate change context.Ecosystem services and multifunctionality of forests could be enhanced by implementing appropriate management measures amidst a changing climate. 展开更多
关键词 Multifunctional forest management THINNING Transition matrix growth model Carbon sink Timber production
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New Algebraic Structures from Hermitian One-Matrix Model
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作者 Xiang Mao DING Yu Ping LI Ling Xian MENG 《Acta Mathematica Sinica,English Series》 SCIE CSCD 2017年第9期1193-1205,共13页
Virasoro constraint is the operator algebra version of one-loop equation for a Hermitian one-matrix model, and it plays an important role in solving the model. We construct the realization of the Virasoro constraint f... Virasoro constraint is the operator algebra version of one-loop equation for a Hermitian one-matrix model, and it plays an important role in solving the model. We construct the realization of the Virasoro constraint from the Conformal Field Theory (CFT) method. From multi-loop equations of the one-matrix model, we get a more general constraint. It can be expressed in terms of the operator algebras, which is the Virasoro subalgebra with extra parameters. In this sense, we named as generalized Virasoro constraint. We enlarge this algebra with central extension, this is a new kind of algebra, and the usual Virasoro algebra is its subalgebra. And we give a bosonic realization of its subalgebra. 展开更多
关键词 matrix model Virasoro constraint conformal symmetry
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A SCATTERING MATRIX MODEL OF SEMICONDUCTOR SUPERLATTICES IN MULTIDIMENSIONAL WAVE-VECTOR SPACE AND ITS DIFFUSION LIMIT
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作者 P.DEGOND ZHANGKAIJUN 《Chinese Annals of Mathematics,Series B》 SCIE CSCD 2003年第2期167-190,共24页
The authors first establish a quantum microscopic scattering matrix model in multidimen-sional wave-vector space, which relates the phase space density of each superlattice cell withthat of the neighbouring cells. The... The authors first establish a quantum microscopic scattering matrix model in multidimen-sional wave-vector space, which relates the phase space density of each superlattice cell withthat of the neighbouring cells. Then, in the limit of a large number of cells, a SHE (SphericalHarmonics Expansion)-type model of diffusion equations for the particle number density in theposition-energy space is obtained. The crucial features of diffusion constants on retaining thememory of the quantum scattering characteristics of the superlattice elementary cell (like e.g.transmission resonances) are shown in order. Two examples are treated with the analyticallycomputation of the diffusion constants. 展开更多
关键词 SUPERLATTICES Scattering matrix model Diffusion approximation Spherical harmonics expansion DRIFT-DIFFUSION Energy transport Transmission resonance
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Ripple-based matrix modeling and cross-coupling effect analysis of double-input DC-DC Boost converters
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作者 ZHANG Hao REN Han +1 位作者 YI ChuanZhi DONG DaChu 《Science China(Technological Sciences)》 SCIE EI CAS CSCD 2022年第8期1878-1890,共13页
This paper deals with the modeling and cross-coupling effect analysis in double-input Boost converters with multiplex current control. A ripple-based multiplex current controlled matrix model is proposed to restore th... This paper deals with the modeling and cross-coupling effect analysis in double-input Boost converters with multiplex current control. A ripple-based multiplex current controlled matrix model is proposed to restore the system's high-frequency domain dynamics information and resolve the coexistence problem of the sample-and-hold effect in multiplex current controllers, which significantly improves the resolution of the conventional average model. Based on the proposed model, both sub-harmonic and low-frequency oscillations are identified in terms of stability analysis, and the inherent mechanism of these complicated nonlinear dynamic behavior is revealed, which not only illustrates the origin of the oscillations but also points out the dominant factors in diverse types of instability situation. Besides, cross-coupling effect analysis is performed to study the interaction between the input ports with the help of the Gershgorin band, and the mechanism of the special unbalanced oscillation phenomenon is revealed. Furthermore, the sensitivity analysis approach is used to identify the key parameters with respect to the cross-coupling effect, which provides more design-oriented knowledge for practical engineering. In addition, the benefits of the proposed model are further illustrated through a comparative analysis. Finally, these theoretical results are verified by experimental ones. These results are beneficial to the improvement of performance as well as the understanding of the cross-coupling effect of multi-input converters. 展开更多
关键词 ripple-based matrix model cross-coupling effect multiplex current control multi-input converter Gershgorin band
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Derived vascular endothelial cells induced by mucoepidermoid carcinoma cells:3-dimensional collagen matrix model
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作者 Sen YANG Li-juan GUO +7 位作者 Qing-hong GAO Ming XUAN Ke TAN Qiang ZHANG Yu-ming WEN Chang-mei WANG Xiu-fa TANG Xiao-yi WANG 《Journal of Zhejiang University-Science B(Biomedicine & Biotechnology)》 SCIE CAS CSCD 2010年第10期745-753,共9页
Mucoepidermoid carcinoma undergoes uniquely vigorous angiogenic and neovascularization processes,possibly due to proliferation of vascular endothelial cells(ECs) induced by mucoepidermoid carcinoma cells(MCCs) in thei... Mucoepidermoid carcinoma undergoes uniquely vigorous angiogenic and neovascularization processes,possibly due to proliferation of vascular endothelial cells(ECs) induced by mucoepidermoid carcinoma cells(MCCs) in their three-dimensional(3D) microenvironment.To date,no studies have dealt with tumor cells and vascular ECs from the same origin of mucoepidermoid carcinoma using the in vitro 3D microenvironment model.In this context,the current research aims to observe neovascularization with mucoepidermoid carcinoma microvascular ECs(MCMECs) conditioned by the microenvironment in the 3D collagen matrix model.We observed the growth of MCMECs purified by immunomagnetic beads and induced by MCCs,and characteristics of tubule-like structures(TLSs) formed by induced MCMECs or non-induced MCMECs.The assessment parameters involved the growth curve,the length,the outer and inner diameters,and the wall thickness of the TLSs,and the cell cycle.Results showed that MCCs induced formation of the TLSs in the 3D collagen matrix model.A statistically significant difference was noted regarding the count of TLSs between the control group and the induction group on the 4th day of culture(t=5.00,P=0.001).The outer and inner diameters(t1=5.549,P1=0.000;t2=10.663,P2=0.000) and lengths(t=18.035,P=0.000) of the TLSs in the induction group were statistically significant larger than those in the control group.The TLSs were formed at the earlier time in the induction group compared with the control group.It is concluded that MCCs promote growth and migration of MCMECs,and formation of the TLSs.The 3D collagen matrix model with MCMECs induced by MCCs in the current research may be a favorable choice for research on pro-angiogenic factors in progression of mucoepidermoid carcinoma. 展开更多
关键词 Mucoepidermoid carcinoma Vascular endothelial cells 3-dimensional collagen matrix model
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Theory-Intelligent Dynamic Matrix Model of Flatness Control for Cold Rolled Strips 被引量:12
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作者 LIU Hong-min SHAN Xiu-ying JIA Chun-yu 《Journal of Iron and Steel Research International》 SCIE EI CAS CSCD 2013年第8期1-7,共7页
In order to increase the precision of flatness control, considering the principle and the measured data of rolling process essence, the theory-intelligent dynamic matrix model of flatness control is established by usi... In order to increase the precision of flatness control, considering the principle and the measured data of rolling process essence, the theory-intelligent dynamic matrix model of flatness control is established by using theory and in-telligent methods synthetically. The network model for rapidly calculating the theory effective matrix is established by the BP network optimized by the particle swarm algorithm. The network model for rapidly calculating the meas- urement effective matrix is established by the RBF network optimized by the cluster algorithm. The flatness control model can track the practical situation of roiling process by on-line selVlearning. The scheme for flatness control quantity calculation is established by combining the theory control matrix and the measurement control matrix. The simulation result indicates that the establishment of theory-intelligent dynamic matrix model of flatness control with stable control process and high precision supplies a new way and method for studying flatness on-line control model. 展开更多
关键词 flatness control dynamic matrix theory model measured data neural network particle swarm CLUSTER
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Error propagation with R-matrix model fitting 被引量:1
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作者 陈振鹏 张瑞 +1 位作者 孙业英 刘挺进 《Science China(Physics,Mechanics & Astronomy)》 SCIE EI CAS 2003年第3期225-234,共10页
The error propagation features with R-matrix model fitting 7Li, 11B and 17O systems have been researched systematically. Some laws of error propagation have been revealed, an experience formula for describing standard... The error propagation features with R-matrix model fitting 7Li, 11B and 17O systems have been researched systematically. Some laws of error propagation have been revealed, an experience formula for describing standard error propagation has been established, and the most possible error range for evaluated standard cross section of 6Li (n, α), 10B (n, α) and 10B (n, α1) has been determined. 展开更多
关键词 R-matrix model ERROR propagation covariance NUCLEAR standard CROSS section.
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Modeling mechanism of a novel fractional grey mode based on matrix analysis 被引量:3
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作者 shuhua mao min zhu +2 位作者 xinping yan mingyun gao xinping xiao 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2016年第5期1040-1053,共14页
To fully display the modeling mechanism of the novelfractional order grey model (FGM (q,1)), this paper decomposesthe data matrix of the model into the mean generation matrix, theaccumulative generation matrix and... To fully display the modeling mechanism of the novelfractional order grey model (FGM (q,1)), this paper decomposesthe data matrix of the model into the mean generation matrix, theaccumulative generation matrix and the raw data matrix, whichare consistent with the fractional order accumulative grey model(FAGM (1,1)). Following this, this paper decomposes the accumulativedata difference matrix into the accumulative generationmatrix, the q-order reductive accumulative matrix and the rawdata matrix, and then combines the least square method, findingthat the differential order affects the model parameters only byaffecting the formation of differential sequences. This paper thensummarizes matrix decomposition of some special sequences,such as the sequence generated by the strengthening and weakeningoperators, the jumping sequence, and the non-equidistancesequence. Finally, this paper expresses the influences of the rawdata transformation, the accumulation sequence transformation,and the differential matrix transformation on the model parametersas matrices, and takes the non-equidistance sequence as an exampleto show the modeling mechanism. 展开更多
关键词 fractional order grey model generalized accumulativegeneration matrix decomposition non-equidistance sequence modeling mechanism.
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A Study Regarding Solution of a Knowledge Model Based on the Containing-Type Error Matrix Equation 被引量:1
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作者 Xilin Min Kaizhong Guo Jize Huang 《Engineering(科研)》 2012年第8期484-492,共9页
An error matrix equation based on error matrix theory was presented in previous research of the error-eliminating theory. The purpose of solving the error matrix equation is to create a decision support on how to swit... An error matrix equation based on error matrix theory was presented in previous research of the error-eliminating theory. The purpose of solving the error matrix equation is to create a decision support on how to switch from bad to good status. A matrix based on error logic is used to express current status u, expectant status u1 and transformation matrix T. It is u, u1, and T that are used to build error matrix equation T (u)= u1. This allows us to find a method whereby bad status “u” changes to good status “u1” by solving the equation. The conversion method that transform from current to expectant status can be obtained from the transformation matrix T. On this basis, this paper proposes a new kind of error matrix equation named “containing-type error matrix equation”. This equation is more suitable for analyzing the realistic question. The method of solving, existence and form of solution for this type of equation have been presented in this paper. This research provides a potential useful new technique for decision analysis. 展开更多
关键词 ERROR matrix SET EQUATION Containing-Type ERROR matrix EQUATION KNOWLEDGE model
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Unsupervised Multi-Level Non-Negative Matrix Factorization Model: Binary Data Case
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作者 Qingquan Sun Peng Wu +2 位作者 Yeqing Wu Mengcheng Guo Jiang Lu 《Journal of Information Security》 2012年第4期245-250,共6页
Rank determination issue is one of the most significant issues in non-negative matrix factorization (NMF) research. However, rank determination problem has not received so much emphasis as sparseness regularization pr... Rank determination issue is one of the most significant issues in non-negative matrix factorization (NMF) research. However, rank determination problem has not received so much emphasis as sparseness regularization problem. Usually, the rank of base matrix needs to be assumed. In this paper, we propose an unsupervised multi-level non-negative matrix factorization model to extract the hidden data structure and seek the rank of base matrix. From machine learning point of view, the learning result depends on its prior knowledge. In our unsupervised multi-level model, we construct a three-level data structure for non-negative matrix factorization algorithm. Such a construction could apply more prior knowledge to the algorithm and obtain a better approximation of real data structure. The final bases selection is achieved through L2-norm optimization. We implement our experiment via binary datasets. The results demonstrate that our approach is able to retrieve the hidden structure of data, thus determine the correct rank of base matrix. 展开更多
关键词 Non-Negative matrix FACTORIZATION BAYESIAN model RANK Determination Probabilistic model
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IMPROVED ESTIMATES OF THE COVARIANCE MATRIX IN GENERAL LINEAR MIXED MODELS
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作者 叶仁道 王松桂 《Acta Mathematica Scientia》 SCIE CSCD 2010年第4期1115-1124,共10页
In this article, the problem of estimating the covariance matrix in general linear mixed models is considered. Two new classes of estimators obtained by shrinking the eigenvalues towards the origin and the arithmetic ... In this article, the problem of estimating the covariance matrix in general linear mixed models is considered. Two new classes of estimators obtained by shrinking the eigenvalues towards the origin and the arithmetic mean, respectively, are proposed. It is shown that these new estimators dominate the unbiased estimator under the squared error loss function. Finally, some simulation results to compare the performance of the proposed estimators with that of the unbiased estimator are reported. The simulation results indicate that these new shrinkage estimators provide a substantial improvement in risk under most situations. 展开更多
关键词 Covariance matrix shrinkage estimator linear mixed model EIGENVALUE
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A New Quantum Number Triangular Array That Defines the Internal Organization of Valence Quarks, the Hadron Quark Model, and the CKM Matrix 被引量:1
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作者 Donald William Chakeres Richard Vento 《Journal of Modern Physics》 2016年第1期145-155,共11页
Purpose: The Harmonic Neutron Hypothesis, HNH, has demonstrated that many of the fundamental physical constants, including the quarks, are associated with partial harmonic fractional exponents, , of a fundamental freq... Purpose: The Harmonic Neutron Hypothesis, HNH, has demonstrated that many of the fundamental physical constants, including the quarks, are associated with partial harmonic fractional exponents, , of a fundamental frequency, v<sub>F</sub>. The model has shown that the properties of the quarks are based on a progression of prime number composites. They also fall on three separate power law lines related to integer factors of the Y-intercept, , of a fundamental electromagnetic line which is scaled by the Rydberg constant, R and Planck’s constant. The quark lines are scaled by the quantum number factors {1, 2, 3}, and their Y-intercepts are referred to as n<sub>bem</sub>. The goal is to present a new proto-quark model in a six-quark inverted triangular array that defines the global organization of the valence quarks, which determines the hadronic quantum numbers, the standard hadron quark model, and the Cabibbo-Kobayashi-Maskawa (CKM) matrix. Methods: The charm, bottom, top quarks are associated with power law line Y-intercept, n<sub>bem</sub> equal to 1;the strange and down quarks with n<sub>bem</sub> equal to 2;and the up quark with n<sub>bem</sub> equal to 3. An inverted equilateral triangular array with three rows arranged from upper row (triangle base) to bottom row (triangle vertex), is associated respectively with n<sub>bem</sub> numbers 1, 2, and 3. The novelty of our perspective thus defines a new global valence quark organization which supersedes the Standard hadron composite quark model. The quarks are ordered via relative mass, partial fractions, and n<sub>bem</sub> quantum number. The top row of our inverted triangle includes the c, b, and t quarks from left to right;the middle row depicts the d and s quarks;and the bottom row, the up quark. Results: Our array depicts a quantum generator of the global organization of the valence quarks defining the composite quark model. The vertices of the triangular array are the up quarks, the midpoints are the down quarks. All weak transitions are from a corner to a midpoint or vice versa. The standard 3 by 3 CKM matrix is generated from the new quark triangle with each up type quark (u, c, and t) transforming to each down type (d, s, and b), with their experimental flavor transition magnitudes given. Conclusion: A new quark quantum number, n<sub>bem</sub>, is an important discovery that generates a new proto-valence quark triangle that secondarily generates the composite quark model and the CKM matrix. 展开更多
关键词 QUARKS Quark model Neutron Cabibbo-Kobayashi-Maskawa matrix Fundamental Physical Constants Fundamental Particles Unification models
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Simplified prediction model for elastic modulus of particulate reinforced metal matrix composites
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作者 王文明 潘复生 +1 位作者 鲁云 曾苏民 《中国有色金属学会会刊:英文版》 CSCD 2006年第A03期1584-1587,共4页
Some structural parameters of the metal matrix composite, including particulate shape and distribution do not influence the elastic modulus. A prediction model for the elastic modulus of particulate reinforced metal m... Some structural parameters of the metal matrix composite, including particulate shape and distribution do not influence the elastic modulus. A prediction model for the elastic modulus of particulate reinforced metal matrix Al composite was developed and improved. Expressions of rigidity and flexibility of the rule of mixing were proposed. A five-zone model for elasticity performance calculation of the composite was proposed. The five-zone model is thought to be able to reflect the effects of the MMC interface on elastic modulus of the composite. The model overcomes limitations of the currently-understood rigidity and flexibility of the rule of mixing. The original idea of a five-zone model is to propose particulate/interface interactive zone and matrix/interface interactive zone. By integrating organically with the law of mixing, the new model is found to be capable of predicting the engineering elastic constants of the MMC composite. 展开更多
关键词 弹性模数 金属化合物 金属变形 金属加工
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Tool life modeling for evaluating the effects of cutting speed and reinforcements on the machining of particle reinforced metal matrix composites
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作者 Metin Kk 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2010年第3期353-362,共10页
The wear of cutting tools in the machining of 2024Al alloy composites reinforced with Al2O3 particles using varying sizes and volume fractions of particles up to 23.3vol% was investigated by a turning process using co... The wear of cutting tools in the machining of 2024Al alloy composites reinforced with Al2O3 particles using varying sizes and volume fractions of particles up to 23.3vol% was investigated by a turning process using coated carbide tools K10 and TP30 at different cut- ting speeds. Machining tests were performed with a plan of experiments based on the Taguchi method. The tool life model was developed in terms of cutting speed, size, and volume fraction of particles by multiple linear regressions. The analysis of variance (ANOVA) was also employed to carry out the effects of these parameters on the cutting tool life. The test results show that the tool life decreases with the increase of cutting speed for both cutting tools K10 and TP30, and the tool life of the K10 tool is significantly longer than that of the TP30 tool. For the tool life, cutting speed is found to be the most effective factor followed by particle content and particle size, respectively. The predicted tool life of cutting tools is found to be in very good agreement with the experimentally observed ones. 展开更多
关键词 metal matrix composites analysis of variance mathematical modeling tool life
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Mechanical Behaviour Modelling of an Mg-Stabilized Zirconia Reinforced TRIP-Matrix-Composite under Cold Working Conditions
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作者 Sergey Guk Wolfhart Müller +1 位作者 Katja Pranke Rudolf Kawalla 《Materials Sciences and Applications》 2014年第11期812-822,共11页
In the present work, a new method to predict the stress-strain curves for three-phase materials has been developed. It was applied using the example of an Mg-stabilized zirconia reinforced TRIP-matrix-composite. The c... In the present work, a new method to predict the stress-strain curves for three-phase materials has been developed. It was applied using the example of an Mg-stabilized zirconia reinforced TRIP-matrix-composite. The content of the ceramic phase was varied between 5% and 20%, whereas the particle size of the ceramic was selected to be 30 to 50 μm. The method is a further development of mixture rule for multiphase materials with more than two microstructure components. The prediction results were compared with the original method of mixture rule and with the IsoE-method. It is shown that the new method significantly improves the convergence compared to the standard method for mixture rule, even though it does not reach the accuracy of IsoE-method. Furthermore, there is an improvement of predicted convergence for large values of the total stress. Finally, a working map was designed for a quick graphical definition of the objective functions. 展开更多
关键词 modelLING Mechanical Behaviour Metal matrix COMPOSITE TRIP-Steel ZRO2
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PROPER APPLICATION OF A KIND OF MATRIX CON-STRUCTION METHOD IN PHYSICAL PARAMETER IDENTIFICATION OF DYNAMIC MODEL
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作者 李书 张放 +1 位作者 王波 张晓谷 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 2002年第5期606-613,共8页
The expressions of matrix construction by using the singular value decomposition (SVD) are applied to the physics parameter identification of dynamic model. Then, based upon to the characteristics of a kind of matrix ... The expressions of matrix construction by using the singular value decomposition (SVD) are applied to the physics parameter identification of dynamic model. Then, based upon to the characteristics of a kind of matrix construction method, the orders of the parameter identification model can be reduced. After reducing, the mathematics and physics correspondence relations between the subsystem and the original system are distinct. the condensation errors can be avoided. The numerical example shows the benefit of the presented methodology. 展开更多
关键词 dynamic model parameter identification inverse problem VIBRATION matrix construction
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Schedule Model for Project Portfolio Based on Design Structure Matrix
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作者 LI Sui-ke BAI Si-jun GUO Yu-tao 《International Journal of Plant Engineering and Management》 2013年第1期50-57,共8页
To improve the enterprise resource utilization and shorten the cycle of the whole project portfolio, a scheduling model based on Design Structure Matrix (DSM) is built. By setting the project activity weight index s... To improve the enterprise resource utilization and shorten the cycle of the whole project portfolio, a scheduling model based on Design Structure Matrix (DSM) is built. By setting the project activity weight index system and calculating the activity weight for the project portfolio, the constraint relationship between project portfolio information and resource utilization, as the two dimensions of the DSM, are fully reflected in the sched- ule model to determine the order of these activities of project portfolio. A project portfolio example is given to il- lustrate the applicability and effectiveness of the schedule model. 展开更多
关键词 project portfolio schedule model design structure matrix activity weight index system
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A matrix Padé-type-Routh model reduction method for multivariable linear systems
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作者 吴蓓蓓 顾传青 《Journal of Shanghai University(English Edition)》 CAS 2006年第5期377-380,共4页
In the present paper, the formulae for matrix Padé-type approximation were improved. The mixed model reduction method of matrix Padé-type-Routh for the multivariable linear systems was presented. A well-know... In the present paper, the formulae for matrix Padé-type approximation were improved. The mixed model reduction method of matrix Padé-type-Routh for the multivariable linear systems was presented. A well-known example was given to illustrate that the mixed method is efficient. 展开更多
关键词 matrix Padé-type approximation(MPTA) Routh table model reduction multivariable linear systems
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基于EKF参数辨识的矩阵变换器间接模型预测控制
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作者 张建伟 杨再欣 +1 位作者 王云辉 刘广忱 《电气传动》 2025年第1期18-24,共7页
为解决矩阵变换器的直接模型预测控制算法计算量大的问题,基于矩阵变换器的等效间接调制策略,将矩阵变换器的预测控制等效为虚拟整流环节和虚拟逆变环节的预测控制。与传统的直接模型预测控制方法相比,间接模型预测控制的算法计算量明... 为解决矩阵变换器的直接模型预测控制算法计算量大的问题,基于矩阵变换器的等效间接调制策略,将矩阵变换器的预测控制等效为虚拟整流环节和虚拟逆变环节的预测控制。与传统的直接模型预测控制方法相比,间接模型预测控制的算法计算量明显降低,减少了算法的执行时间。针对预测控制对模型参数依赖度较高的问题,采用扩展卡尔曼滤波器对系统模型参数进行在线辨识,进而提高模型预测控制的鲁棒性和抗干扰能力。实验结果表明,所提出的基于扩展卡尔曼滤波器参数辨识算法的间接模型预测控制对负载电流和网侧单位功率因数具有良好的控制效果,并且对模型参数的依赖度降低。 展开更多
关键词 矩阵变换器 模型预测控制 计算量 扩展卡尔曼滤波器 参数辨识
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