期刊文献+
共找到9篇文章
< 1 >
每页显示 20 50 100
Study of the generalized mixture rule for determining effective conductivity of two-phase stochastic models 被引量:1
1
作者 余勇 吴小平 《Applied Geophysics》 SCIE CSCD 2010年第3期210-216,292,共8页
The generalized mixture rule (GMR) is usually applied in determining mechanical properties such as the rheological property and Young’s modulus of multi-phase rocks. However, it is rarely used to determine electric... The generalized mixture rule (GMR) is usually applied in determining mechanical properties such as the rheological property and Young’s modulus of multi-phase rocks. However, it is rarely used to determine electrical conductivity of multi-phase rocks presently. In this paper, we calculate the effective conductivity using the 3D finite element method for a large number of two-phase medium stochastic models. The GMR is then employed as an effective conductivity model to fit the data. It shows a very close relationship between the parameter J of GMR and the ratio of conductivities of the two phases. We obtain the equations of the parameter J with the ratio of conductivity of two phases for the first time. On this basis, we can quickly predict (or calculate) the effective conductivity of any twophase medium stochastic model. The result is much more accurate than two other available effective conductivity models for the stochastic medium, which are the random model and effective medium theory model, laying a solid base for detailed evaluation of oil reservoirs. 展开更多
关键词 Generalized mixture rule two-phase media effective conductivity
下载PDF
Modeling and analysis of piezoelectric beam with periodically variable cross-sections for vibration energy harvesting 被引量:7
2
作者 M.HAJHOSSEINI M.RAFEEYAN 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI CSCD 2016年第8期1053-1066,共14页
A bimorph piezoelectric beam with periodically variable cross-sections is used for the vibration energy harvesting. The effects of two geometrical parameters on the first band gap of this periodic beam are investigate... A bimorph piezoelectric beam with periodically variable cross-sections is used for the vibration energy harvesting. The effects of two geometrical parameters on the first band gap of this periodic beam are investigated by the generalized differential quadrature rule (GDQR) method. The GDQR method is also used to calculate the forced vibration response of the beam and voltage of each piezoelectric layer when the beam is subject to a sinusoidal base excitation. Results obtained from the analytical method are compared with those obtained from the finite element simulation with ANSYS, and good agreement is found. The voltage output of this periodic beam over its first band gap is calculated and compared with the voltage output of the uniform piezoelectric beam. It is concluded that this periodic beam has three advantages over the uniform piezoelectric beam, i.e., generating more voltage outputs over a wide frequency range, absorbing vibration, and being less weight. 展开更多
关键词 vibration energy harvesting piezoelectric cantilever beam periodically variable cross-section vibration band gap forced vibration analysis generalized differential quadrature rule (GDQR)
下载PDF
Intelligent Multilevel Knowledge Acquisition System for Product Design and Its Implementation 被引量:1
3
作者 钟佩思 Xu Wensheng +2 位作者 Zeng Qingliang Xiong Guangleng GAO Guoan 《High Technology Letters》 EI CAS 2001年第1期37-41,共5页
The characteristics of design process, design object and domain knowledge of complex product are analyzed. A kind of knowledge representation schema based on integrated generalized rule is stated. An AND-OR tree based... The characteristics of design process, design object and domain knowledge of complex product are analyzed. A kind of knowledge representation schema based on integrated generalized rule is stated. An AND-OR tree based model of concept for domain knowledge is set up. The strategy of multilevel domain knowledge acquisition based on the model is presented. The intelligent multilevel knowledge acquisition system (IMKAS) for product design is developed, and it is applied in the intelligent decision support system of concept design of complex product. 展开更多
关键词 Product design Domain knowledge Knowledge representation Generalized rule Knowledge acquisition
下载PDF
A generalized Weyl-Wigner quantization scheme unifying P-Q and Q-P ordering and Weyl ordering of operators 被引量:1
4
作者 王继锁 范洪义 孟祥国 《Chinese Physics B》 SCIE EI CAS CSCD 2012年第6期207-212,共6页
By extending the usual Wigner operator to the s-parameterized one as 1/4π2 integral (dyduexp [iu(q-Q)+iy(p-P)+is/2yu]) from n=- ∞ to ∞ with s beng a,real parameter,we propose a generalized Weyl quantization... By extending the usual Wigner operator to the s-parameterized one as 1/4π2 integral (dyduexp [iu(q-Q)+iy(p-P)+is/2yu]) from n=- ∞ to ∞ with s beng a,real parameter,we propose a generalized Weyl quantization scheme which accompanies a new generalized s-parameterized ordering rule.This rule recovers P-Q ordering,Q-P ordering,and Weyl ordering of operators in s = 1,1,0 respectively.Hence it differs from the Cahill-Glaubers’ ordering rule which unifies normal ordering,antinormal ordering,and Weyl ordering.We also show that in this scheme the s-parameter plays the role of correlation between two quadratures Q and P.The formula that can rearrange a given operator into its new s-parameterized ordering is presented. 展开更多
关键词 generalized Wigner operator generalized operator ordering rule bivariate normal dis-tribution
下载PDF
A dynamic decision model for portfolio investment and assets management
5
作者 钱彦敏 冯颖 HIGGISION James 《Journal of Zhejiang University-Science A(Applied Physics & Engineering)》 SCIE EI CAS CSCD 2005年第B08期163-171,共9页
This paper addresses a dynamic portfolio investment problem. It discusses how we can dynamically choose candidate assets, achieve the possible maximum revenue and reduce the risk to the minimum level. The paper genera... This paper addresses a dynamic portfolio investment problem. It discusses how we can dynamically choose candidate assets, achieve the possible maximum revenue and reduce the risk to the minimum level. The paper generalizes Markowitz’s portfolio selection theory and Sharpe’s rule for investment decision. An analytical solution is presented to show how an institu- tional or individual investor can combine Markowitz’s portfolio selection theory, generalized Sharpe’s rule and Value-at-Risk (VaR) to find candidate assets and optimal level of position sizes for investment (dis-investment). The result shows that the gen- eralized Markowitz’s portfolio selection theory and generalized Sharpe’s rule improve decision making for investment. 展开更多
关键词 Portfolio investment Value-at-Risk (VaR) Generalized Sharpe's rule
下载PDF
A Realistic Interpretation of Quantum Wavefunctions as Temperature Dependent Vacuum Polarization Waves
6
作者 Gianpaolo Bei Roberto Li Voti 《Journal of Modern Physics》 2022年第6期892-917,共26页
We discuss in this paper a novel interpretation of Born rule as an approximated thermodynamic law which emerges from the interaction of a quantum system with a non-stationary thermal bath associated to vacuum fluctuat... We discuss in this paper a novel interpretation of Born rule as an approximated thermodynamic law which emerges from the interaction of a quantum system with a non-stationary thermal bath associated to vacuum fluctuations induced by external environment radiation. In particular we assume that vacuum polarization is a real non relativistic phenomena caused by hidden vacuum charge oscillations which diffuses heat energy in a dispersive and dissipative dielectric medium with a temperature dependent speed of propagation. We propose a model which couples vacuum wavefunctions to vacuum charge fluctuations and we deduce a temperature dependent running fine structure constant function proportional, at first approximation, to the squared of the effective electron charge and compatible with known experimental data. We interpret the vacuum symmetry breaking energy fluctuations induced in scattering experiments of particle physics and in laser assisted nuclear reactions as thermal quasi-monochromatic beams produced by the decay of hidden non equilibrium massive photons propagating with a variable light speed. We suggest, exploiting an old analogy between plasmons and pseudo Goldstone bosons, to interpret heat diffusion of this non relativistic polarized vacuum as a real De Broglie electromagnetic scalar wave associated to the radiation emitted by the hidden massive photons with acceleration proportional to vacuum Unruh like temperature. We predict a temperature dependent deviation from Coulomb law and a generalized dispersive law of these hidden unstable photons that could be revealed as not stationary coloured noise in experiments on anomalous heat diffusions associated to the decay of unstable accelerated pairs produced in nuclear physics experiments. We discuss then how our proposal of a temperature dependent non relativistic vacuum polarization might be applied to deduce a dynamic generalization of Born rule based on a realistic interpretation of quantum wavefunctions as averaged electromagnetic waves of hidden massive photons. Finally we suggest to test our time asymmetric model looking for very fast oscillating polarization thermal waves emitted during the not instantaneous wavefunction collapse and revealed as not stationary bulk heating effects in experiments on accelerated conductors and nanoconductors. 展开更多
关键词 Non Relativistic Vacuum Pilot Wave Hidden Temperature Dependent Vacuum Index Hidden Unstable Massive Photons Space Time Dependent Vacuum Temperature Oscillations Temperature Dependent Running Fine Structure Constant Vacuum Temperature Induced Wave Collapse Generalized Born rule
下载PDF
Mining Frequent Generalized Itemsets and Generalized Association Rules Without Redundancy 被引量:2
7
作者 Daniel Kunkle 张冬晖 Gene Cooperman 《Journal of Computer Science & Technology》 SCIE EI CSCD 2008年第1期77-102,共26页
This paper presents some new algorithms to efficiently mine max frequent generalized itemsets (g-itemsets) and essential generalized association rules (g-rules). These are compact and general representations for a... This paper presents some new algorithms to efficiently mine max frequent generalized itemsets (g-itemsets) and essential generalized association rules (g-rules). These are compact and general representations for all frequent patterns and all strong association rules in the generalized environment. Our results fill an important gap among algorithms for frequent patterns and association rules by combining two concepts. First, generalized itemsets employ a taxonomy of items, rather than a flat list of items. This produces more natural frequent itemsets and associations such as (meat, milk) instead of (beef, milk), (chicken, milk), etc. Second, compact representations of frequent itemsets and strong rules, whose result size is exponentially smaller, can solve a standard dilemma in mining patterns: with small threshold values for support and confidence, the user is overwhelmed by the extraordinary number of identified patterns and associations; but with large threshold values, some interesting patterns and associations fail to be identified. Our algorithms can also expand those max frequent g-itemsets and essential g-rules into the much larger set of ordinary frequent g-itemsets and strong g-rules. While that expansion is not recommended in most practical cases, we do so in order to present a comparison with existing algorithms that only handle ordinary frequent g-itemsets. In this case, the new algorithm is shown to be thousands, and in some cases millions, of the time faster than previous algorithms. Further, the new algorithm succeeds in analyzing deeper taxonomies, with the depths of seven or more. Experimental results for previous algorithms limited themselves to taxonomies with depth at most three or four. In each of the two problems, a straightforward lattice-based approach is briefly discussed and then a classificationbased algorithm is developed. In particular, the two classification-based algorithms are MFGI_class for mining max frequent g-itemsets and EGR_class for mining essential g-rules. The classification-based algorithms are featured with conceptual classification trees and dynamic generation and pruning algorithms. 展开更多
关键词 generalized association rules frequent generalized itemsets redundancy avoidance
原文传递
Generalized Multidimensional Association Rules
8
作者 周傲英 周水庚 +1 位作者 金文 田增平 《Journal of Computer Science & Technology》 SCIE EI CSCD 2000年第4期388-392,共5页
The problem of association rule mining has gained considerableprominence in the data mining community for its use as an important tool of knowledge discovery from large-scale databases. And there has been a spurt of r... The problem of association rule mining has gained considerableprominence in the data mining community for its use as an important tool of knowledge discovery from large-scale databases. And there has been a spurt of researchactivities around this problem. Traditional association rule mining is limited tointratransaction. Only recently the concept of N-dimensional inter-transaction association rule (NDITAR) was proposed by H.J. Lu. This paper modifies and extendsLu's definition of NDITAR based on the analysis of its limitations, and the generalized multidimensional association rule (GMDAR) is subsequently introduced, whichis more general, flexible and reasonable than NDITAR. 展开更多
关键词 multidimensional transaction database data mining Ndimensionalinter-transaction association rules (NDITAR) generalized multidimensional association rules (GMDAR)
原文传递
Global Convergence of a Modified Gradient Projection Method for Convex Constrained Problems 被引量:1
9
作者 Qing-ying Sun Chang-yu Wang Zhen-jun Shi 《Acta Mathematicae Applicatae Sinica》 SCIE CSCD 2006年第2期227-242,共16页
In this paper, the continuously differentiable optimization problem min{f(x) : x∈Ω}, where Ω ∈ R^n is a nonempty closed convex set, the gradient projection method by Calamai and More (Math. Programming, Vol.39... In this paper, the continuously differentiable optimization problem min{f(x) : x∈Ω}, where Ω ∈ R^n is a nonempty closed convex set, the gradient projection method by Calamai and More (Math. Programming, Vol.39. P.93-116, 1987) is modified by memory gradient to improve the convergence rate of the gradient projection method is considered. The convergence of the new method is analyzed without assuming that the iteration sequence {x^k} of bounded. Moreover, it is shown that, when f(x) is pseudo-convex (quasiconvex) function, this new method has strong convergence results. The numerical results show that the method in this paper is more effective than the gradient projection method. 展开更多
关键词 Nonlinear programming PROJECTION generalized Armijo step size rule CONVERGENCE
原文传递
上一页 1 下一页 到第
使用帮助 返回顶部