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Angular glint calculation and analysis of radar targets via adaptive cross approximation algorithm

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Journal of Systems Engineering and Electronics 2014年第3期25卷 411-421页

作者： Miao sui Xiaojian Xu School of Electronics and Information Engineering Beihang University

Angular glint is a significant electromagnetic （EM） scattering signature of extended radar targets. Based on the adaptive cross approximation （ACA） algorithm accelerated method of moments （MoM） and the plane incident wave assumption, the narrowband, wideband and newly developed high-resolution range profile （HRRP） based angular glint calculation formulations are derived and applied to arbitrarily shaped three-dimensional （3D） perfectly electrical y conducting （PEC） objects. In addition, the near-field angular glint is emphasized, which is of great importance for radarseeker applications. Furthermore, with the HRRP based angular glint, an approach to rigorously determine range resolution cel s which own relatively smal er angular glint is provided. Numerical results are presented with new findings to demonstrate the usefulness of the developed formulations.

关键词： electromagnetic (EM) scattering radar signature,near-field multistatic scattering.

A computational framework for Karl Popper's logic of scientific discovery

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Science China(Information Sciences) 2018年第4期61卷 97-106页

作者： Wei LI Yuefei sui State Key Laboratory of Software Development Environment Beihang University Key Laboratory of Intelligent Information Processing Institute of Computing TechnologyChinese Academy of Sciences

Belief revision is both a philosophical and logical problem. From Popper’s logic of scientific discovery, we know that revision is ubiquitous in physics and other sciences. The AGM postulates and Rcalculus are approaches from logic, where the R-calculus is a Gentzen-type concrete belief revision *** deduction is undecidable in first-order logic, we apply approximate deduction to derive an R-calculus that is computational and has finite injury. We further develop approximation algorithms for SAT problems to derive a feasible R-calculus based on the relation between deduction and satisfiability. In this manner, we provide a full spectrum of belief revision: from philosophical to feasible revision.

关键词： belief revision logic of scientific discovery approximate deduction approximation algorithms feasible computation

The B4-valued propositional logic with unary logical connectives ～1 /～2/┐

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Frontiers of Computer Science 2017年第5期11卷 887-894页

作者： Wei LI Yuefei sui State Key Laboratory of Software Development Environment Beijing University of Aeronautics and Astronautics Beijing 100191 China Key Laboratory of Intelligent Information Processing Institute of Computing Technology Chinese Academy of Sciences Beijing 100190 China

A B4-valued propositional logic will be proposed in this paper which there are three unary logical connectives ～1, ～2, ┐ and two binary logical connectives A, v, and a Gentzen-typed deduction system will be given s... 详细信息

关键词： the Belnap logic modality the soundness thecompleteness

High density stacking faults of ■ compression twin in magnesium alloys

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Journal of Materials Science & Technology 2019年第10期35卷 2263-2268页

作者： Bo Zhou Manling sui Beijing Key Laboratory of Microstructure and Properties of Solids Institute of Microstructure and Properties of Advanced Materials Beijing University of Technology

■ compression twins with high density stacking faults were studied at atomic scale using Cscorrection transmission electron microscopy. On one side of the ■ twin boundary, there were many steps arranged alternately with the coherent twin boundaries. Most of the steps were linked with stacking faults inside twins. Burgers vector of twinning dislocations and the mismatch strain at steps were characterized. Due to the compressive mismatch strain at steps, the high density stacking faults inside twins were formed at twin tips during twinning process. The localized strain at the steps would be related to the crack nucleation in magnesium alloys.

关键词： Magnesium Twin Stacking faults High resolution transmission electron microscopy

An Analytical Model Based on the Theory of Constant Heat Flux Ratio Across the Frozen Layer for Solving Planar, Cylindrical and Spherical Freezing Problems

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Journal of Thermal Science 2004年第2期13卷 155-162页

作者： sui Lin Zheng Jiang Department of Mechanical and Industrial Engineering Concordia University Montreal Canada Flomerics Inc. Southborough USA

The purpose of the paper is to establish a theory of the constant heat flux ratio across the frozen layer based on the dimensional analysis of the system equations describing the freezing processes. An analytical model is then developed, utilizing this theory, for solving the planar, cylindrical and spherical freezing problems with both inward and outward freezing. As there is no exact solution available for the cylindrical and spherical freezing processes, the temperature distribution in the planar solidification obtained from the model is compared with the exact solution. They are in excellent agreement. For the cylindrical and spherical freezing, the complete inward solidification times calculated by the model are compared with those obtained from references. The results are in good agreement. The great advantage of the proposed model is its simplicity and is sufficiently accurate for most practical

关键词： analytical planar cylindrical spherical solidification theory constant heat flux ratio.

A sound and complete R-calculi with respect to contraction and minimal change

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Frontiers of Computer Science 2014年第2期8卷 184-191页

作者： Wei LI Yuefei sui State Key Laboratory of Software Development Environment Beihang University Beijing 100191 China Key Laboratory of Intelligent Information Processing Institute of Computing Technology Chinese Academy of Sciences Beijing 100190 China

AGM postulates are for belief revision （revision by a single belief）, and DP postulates are for iterated revision （revision by a finite sequence of beliefs）. R-calculus is given for R-configurations △｜Г, where △ is a set of atomic formulas or the negations of atomic formulas, and Г is a finite set of formulas. We shall give two R-calculi C and M （sets of de- duction rules） such that for any finite consistent sets Г, △of formulas in the propositional logic, there is a consistent set ⊙ Г C of formulas such that △IГ → △, ⊙ is provable and⊙ is a contraction of F by A or a minimal change of F by A; and prove that C and M are sound and complete with respect to the contraction and the minimal change, respectively.

关键词： belief revision R-calculus minimal change,contraction

The ICM method with objective function transformed by variable discrete condition for continuum structure

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Acta Mechanica Sinica 2006年第1期22卷 68-75页

作者： Yunkang sui Xirong Peng Numerical Simulation Center for Engineering The College of Mechanical Engineering and Applied Electronics TechnologyBeijing University of TechnologyBeijing 100022

ICM （Independent Continuous Mapping） method can solve topological optimization problems with the minimized weight as the objective and subjected to displacement constraints. To get a clearer topological configuration, by introducing the discrete condition of topological variables and integrating with the original objective, an optimal model with multi-objectives is formulated to make the topological variables approach 0 or 1 as near as possible, and the model reduces the effect of deleting rate on the result. The image-filtering method is employed to eliminate the checkerboard patterns and mesh dependence that occurred in the topology optimization of a continuum structure. The computational efficiency is enhanced through selecting quasi-active displacement constraints and a design region. Numerical examples indicate that this algorithm is robust and practicable, though the number of iterations is slightly increased with respect to the original algorithm.

关键词： Structural topological optimization ICM method Checkerboard patterns Mesh dependence Thedeleting rate

Self-Sustaining of Critical Park Microgrids Integrating Mobile Emergency Generators Subjective to Major Outage

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CSEE Journal of Power and Energy Systems 2024年第4期10卷 1441-1453页

作者： Quan sui Lei Zhang School of Electrical and Information Engineering Zhengzhou UniversityZhengzhou 450001China School of Electrical and New Energy Three Gorges UniversityYichang 443002China

In the event of a major power outage,critical park microgrids(PMGs)could be self-sustaining if mobile emergency generators(MEGs)are stationed to share ***,the need for privacy protection and the value of flexible power support on minute-time scales have not been given enough *** address the problem,this paper proposes a new self-sustaining strategy for critical PMGs integrating ***,to promote the cooperation between PMG and MEG,a bi-level benefit distribution mechanism is designed,where the participants'multiple roles and contributions are identified,and good behaviors are also ***,to increase the alliance benefits,three loss coordination modes are presented to guide the power exchange at the minute level between the MEG and PMG,considering the volatility of renewable generation and *** this basis,a multi-time scale power-energy scheduling strategy is formulated via the alternating direction method of multipliers(ADMM)to coordinate the PMG and ***,a dimensionality reduction technology is designed to equivalently simplify the optimization problem to facilitate the adaptive-step-based ADMM *** studies indicate that the proposed strategy achieves the self-sustaining of PMGs integrating MEGs while increasing the economy by no less than 3.1%.

关键词： Distributed optimization loss coordination mode mobile emergency generator park microgrid power-energy self-sustaining privacy protection

Application of orthogonal experimental design and Tikhonov regularization method for the identification of parameters in the casting solidification process

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Acta Metallurgica Sinica(English Letters) 2009年第1期22卷 13-21页

作者： Dashan sui Zhenshan CUI National Die ＆ Mould CAD Engineering Research Center Shanghai Jiaotong UniversityShanghai 200030 China

The inverse heat conduction method is one of methods to identify the casting simulation parameters. A new inverse method was presented according to the Tikhonov regularization theory. One appropriate regularized functional was established, and the functional was solved by the sensitivity coefficient and Newtonaphson iteration method. Moreover, the orthogonal experimental design was used to estimate the appropriate initial value and variation domain of each variable to decrease the number of iteration and improve the identification accuracy and efficiency. It illustrated a detailed case of AlSiTMg sand mold casting and the temperature measurement experiment was done. The physical properties of sand mold and the interracial heat transfer coefficient were identified at the meantime. The results indicated that the new regularization method was efficient in overcoming the ill-posedness of the inverse heat conduction problem and improving the stability and accuracy of the solutions.

关键词： Orthogonal experimental design Regularization method Parameters identification Numerical simulation