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Invertibility of Infinite-Dimensional Hamiltonian Operators and Its Application to Plate Bending Equation 被引量:2
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作者 Alatancang 《Communications in Theoretical Physics》 SCIE CAS CSCD 2008年第3期562-566,共5页
The results of invertibility and spectrum for some different classes of infinite-dimensional Hayniltonian operators, after a brief classification by domains. are given. By the above results, the associated infinite-di... The results of invertibility and spectrum for some different classes of infinite-dimensional Hayniltonian operators, after a brief classification by domains. are given. By the above results, the associated infinite-dimensional Hamiltonian operator with simple supported rectangular plate is proved to be invertible. Furthermore, by a certain compactness, we find that the spectrum of this operator consists only of isolated eigenvalues with finite geometric multiplicity, which will play a significant role in finding the analytical and numerical solution based on Hamiltonian system for a class of plate bending equations. 展开更多
关键词 vplate bending equation invertibility infinite-dimensional Hamiltonian operator
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Motion-Blurred Image Restoration Based on Joint Invertibility of PSFs 被引量:1
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作者 Yuye Zhang Jingli Huang +1 位作者 Jiandong Liu Hakeel Ahmed Chohan 《Computer Systems Science & Engineering》 SCIE EI 2021年第2期407-416,共10页
To implement restoration in a single motion blurred image,the PSF(Point Spread Function)is difficult to estimate and the image deconvolution is ill-posed as a result that a good recovery effect cannot be obtained.Cons... To implement restoration in a single motion blurred image,the PSF(Point Spread Function)is difficult to estimate and the image deconvolution is ill-posed as a result that a good recovery effect cannot be obtained.Considering that several different PSFs can get joint invertibility to make restoration wellposed,we proposed a motion-blurred image restoration method based on joint invertibility of PSFs by means of computational photography.Firstly,we designed a set of observation device which composed by multiple cameras with the same parameters to shoot the moving target in the same field of view continuously to obtain the target images with the same background.The target images have the same brightness,but different exposure time and different motion blur length.It is easy to estimate the blur PSFs of the target images make use of the sequence frames obtained by one camera.According to the motion blur superposition feature of the target and its background,the complete blurred target images can be extracted from the observed images respectively.Finally,for the same target images with different PSFs,the iterative restoration is solved by joint solution of multiple images in spatial domain.The experiments showed that the moving target observation device designed by this method had lower requirements on hardware conditions,and the observed images are more convenient to use joint-PSF solution for image restoration,and the restoration results maintained details well and had lower signal noise ratio(SNR). 展开更多
关键词 Motion-blurred image restoration PSF invertibility ill-posed problem computational photography
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Strong Invertibility of Nonlinear Systems and Its Application
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作者 刘军 戴先中 《Journal of Southeast University(English Edition)》 EI CAS 1997年第1期103-108,共6页
From the point of mathematical mapping, this paper discusses the invertibility of nonlinear systems, and presents definition, equivalence theorem, sufficient and necessary conditions of strong invertibility for single... From the point of mathematical mapping, this paper discusses the invertibility of nonlinear systems, and presents definition, equivalence theorem, sufficient and necessary conditions of strong invertibility for single input single output systems. Then it analyzes the feasibility of inverse system control method, and yields some conclusions on feasibility. 展开更多
关键词 NONLINEAR SYSTEMS INVERSE system STRONG invertibility
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On Invertibility of Functional Operators with Shift in Weighted Holder Spaces
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作者 Anna Tarasenko Oleksandr Karelin 《Advances in Pure Mathematics》 2014年第11期595-600,共6页
In this paper, we consider functional operators with shift in weighted H?lder spaces. We present the main idea and the scheme of proof of the conditions of invertibility for these operators. As an application, we prop... In this paper, we consider functional operators with shift in weighted H?lder spaces. We present the main idea and the scheme of proof of the conditions of invertibility for these operators. As an application, we propose to use these results for solution of equations with shift which arise in the study of cyclic models for natural systems with renewable resources. 展开更多
关键词 Functional Operator with Shift Holder Space Conditions of invertibility Renewable Resources
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Weak invertibility of linear finite automata (I)——Classification and enumeration of transfer functions 被引量:5
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作者 戴宗铎 叶顶峰 《Science China Mathematics》 SCIE 1996年第6期613-623,共11页
Let 3V denote the set of all possible transfer function matrices of weakly invertible linear finite automata over a given finite field F. A classification and an enumeration on the infinite set are given.
关键词 linear FINITE AUTOMATON WEAK invertibility CLASSIFICATION enumeration.
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Linear Maps Preserving Invertibility or Related Spectral Properties 被引量:5
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作者 JinChuanHOU PeterSEMRL 《Acta Mathematica Sinica,English Series》 SCIE CSCD 2003年第3期473-484,共12页
We survey some recent results on linear maps on operator algebras that preserve invertibility. We also consider related problems such as the problem of the characterization of linear maps preserving spectrum, various ... We survey some recent results on linear maps on operator algebras that preserve invertibility. We also consider related problems such as the problem of the characterization of linear maps preserving spectrum, various parts of spectrum, spectral radius, quasinilpotents, etc. We present some results on elementary operators and additive operators preserving invertibility or related properties. In particular, we give a negative answer to a problem posed by Gao and Hou on characterizing spectrum-preserving elementary operators. Several open problems are also mentioned. 展开更多
关键词 Operator algebras Linear preservers invertibility SPECTRUM
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The Invertibility of Rational Univariate Representations 被引量:2
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作者 XIAO Shuijing ZENG Guangxing 《Journal of Systems Science & Complexity》 SCIE EI CSCD 2022年第6期2430-2451,共22页
In this paper,the so-called invertibility is introduced for rational univariate representations,and a characterization of the invertibility is given.It is shown that the rational univariate representations,obtained by... In this paper,the so-called invertibility is introduced for rational univariate representations,and a characterization of the invertibility is given.It is shown that the rational univariate representations,obtained by both Rouillier’s approach and Wu’s method,are invertible.Moreover,the ideal created by a given rational univariate representation is defined.Some results on invertible rational univariate representations and created ideals are established.Based on these results,a new approach is presented for decomposing the radical of a zero-dimensional polynomial ideal into an intersection of maximal ideals. 展开更多
关键词 invertibility polynomial ideal rational univariate representation(RUR) Wu’s method ZERO-DIMENSIONAL
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Constructing Finite Automata with Invertibility bytransformation Method 被引量:2
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作者 陶仁骥 陈世华 《Journal of Computer Science & Technology》 SCIE EI CSCD 2000年第1期10-26,共17页
Ra, Rb transformations were successfully applied to establish invertibility theory for linear and quasi-linear finite automata over finite fields. In aprevious paper, the authors generalized R., Rb transformations to ... Ra, Rb transformations were successfully applied to establish invertibility theory for linear and quasi-linear finite automata over finite fields. In aprevious paper, the authors generalized R., Rb transformations to deal with nonlinear memory finite automata, and gave sufficient conditions for weak inverse andfor weakly invertible memory finite automata and inversion processes concerned;methods by transformation to generate a kind of nonlinear memory finite automatasatisfying one of these sufficient conditions were also given. This paper extends theconcepts, methods and results to general finite automata, in which states consist offinite input history, finite output history and finite 'inner state' history. 展开更多
关键词 finite automata invertibility public key cryptosystem
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Additive Maps on Matrix Algebras Preserving Invertibility or Singularity 被引量:2
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作者 Ajda FO NER Peter EMRL 《Acta Mathematica Sinica,English Series》 SCIE CSCD 2005年第4期681-684,共4页
We characterize the additive singularity preserving almost surjective maps on Mn (F), the algebra of all n×n matrices over a field F with char F=0. We also describe additive invertibility preserving surjective ... We characterize the additive singularity preserving almost surjective maps on Mn (F), the algebra of all n×n matrices over a field F with char F=0. We also describe additive invertibility preserving surjective maps on Mn (F) and give examples showing that all the assunlptions in these two theorems are indispensable. 展开更多
关键词 Additive map invertibility preserver Singularity preserver
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Weak invertibility of linear finite automata over rings——Classification and enumeration 被引量:1
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作者 戴宗铎 叶顶锋 《Chinese Science Bulletin》 SCIE EI CAS 1996年第3期190-196,共7页
The weak invertibility problem of finite automata (FAs) has received continuous considerations. The weak invertibility theory has applications in cryptography, both conventional cryptosystems and public key cryptosyst... The weak invertibility problem of finite automata (FAs) has received continuous considerations. The weak invertibility theory has applications in cryptography, both conventional cryptosystems and public key cryptosystems. Given a finite commutative ring (?) with identity, it is known, that the weak invertibility of a linear finite automaton(LFA) over (?) depends only on its transfer function matrix. Let H be the set of all possible transfer function matrices which weakly invertible LFAs over (?) can have. Our 展开更多
关键词 linear FINITE AUTOMATON WEAK invertibility transfer function matrix.
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Bijections Preserving Invertibility of Differences of Matrices on H_n 被引量:1
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作者 Damjan KOBAL 《Acta Mathematica Sinica,English Series》 SCIE CSCD 2008年第10期1651-1654,共4页
We characterise bijections on the space of hermitian matrices preserving the invertibility of differences of matrix pairs in both directions.
关键词 HERMITIAN invertibility PRESERVER ADJACENCY full rank
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The stationarity and invertibility of a class of nonlinear ARMA models 被引量:1
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作者 CHEN DanQing WANG HaiBin 《Science China Mathematics》 SCIE 2011年第3期469-478,共10页
We investigate some probabilistic properties of a new class of nonlinear time series models.A sufficient condition for the existence of a unique causal,strictly and weakly stationary solution is derived.To understand ... We investigate some probabilistic properties of a new class of nonlinear time series models.A sufficient condition for the existence of a unique causal,strictly and weakly stationary solution is derived.To understand the proposed models better,we further discuss the moment structure and obtain some Yule-Walker difference equations for the second and third order cumulants,which can also be used for identification purpose.A sufficient condition for invertibility is also provided. 展开更多
关键词 auto-covariance invertibility stationarity time series Yule-Walker difference equation
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Drazin Invertibility of Operators AB and BA 被引量:1
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作者 陆建明 杜鸿科 魏小梅 《Journal of Mathematical Research and Exposition》 CSCD 北大核心 2008年第4期1017-1020,共4页
In this note an alternative proof of the equivalence of Drazin invertibility of operators AB and BA is given. As an application, we will prove that σD(AB) = σD(BA) and σD(A) = σD(A), where σD(M) and ■ denote the... In this note an alternative proof of the equivalence of Drazin invertibility of operators AB and BA is given. As an application, we will prove that σD(AB) = σD(BA) and σD(A) = σD(A), where σD(M) and ■ denote the Drazin spectrum and the Aluthge transform of an operator M ∈ B(H), respectively. 展开更多
关键词 Drazin invertibility of operators Drazin index Aluthge transforms of operators.
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Robust current tracking control for three-phase grid-connected inverters with LCL filter
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作者 LIU Wei WU Ben +2 位作者 SUN Wei-jie XUE Ying CAI Feng-huang 《控制理论与应用》 北大核心 2026年第1期41-51,共11页
This article investigates the robust current tracking control problem of three-phase grid-connected inverters with LCL filter under external disturbance by a dynamic state feedback control method.First,this paper cons... This article investigates the robust current tracking control problem of three-phase grid-connected inverters with LCL filter under external disturbance by a dynamic state feedback control method.First,this paper constructs an internal model to learn the information of the states and input of the grid-connected inverter under steady state.Second,by utilizing the internal model principle,the paper turns the tracking control problem into the robust stabilization control problem based on some appropriate coordinate transformations.Then,The paper designs a dynamics state feedback control law to deal with this robust stabilization problem,and thus the solution of the robust current tracking control problem of three-phase grid-connected inverters can be obtained.This control method can ensure the asymptotic stability of the closedloop system.Finally,the paper illustrates the effectiveness of the proposed control approach through several groups of simulations,and compares it with the feedforward control method to verify the robustness of the proposed control method to uncertain parameters. 展开更多
关键词 grid-connected inverter internal model principle current tracking disturbance suppression robust control
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A necessary condition on invertibility of finite automata
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作者 陶仁骥 陈世华 《Science China(Technological Sciences)》 SCIE EI CAS 1997年第6期637-640,642-643,共6页
This paper gives a necessary condition for a kind of weakly invertible, invertible, weak inverse or inverse finite automata by linear RaRb transformation sequence. For such finite automata the existence of terminating... This paper gives a necessary condition for a kind of weakly invertible, invertible, weak inverse or inverse finite automata by linear RaRb transformation sequence. For such finite automata the existence of terminating RaRb transformation sequence is also established. 展开更多
关键词 FINITE AUTOMATA RaRb TRANSFORMATION invertibility.
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Invertibility of Bergman Toeplitz operators with harmonic polynomial symbols
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作者 Nanxing Guan Xianfeng Zhao 《Science China Mathematics》 SCIE CSCD 2020年第5期965-978,共14页
Let p be an analytic polynomial on the unit disk.We obtain a necessary and sufficient condition for Toeplitz operators with the symbol z+p to be invertible on the Bergman space when all coefficients of p are real numb... Let p be an analytic polynomial on the unit disk.We obtain a necessary and sufficient condition for Toeplitz operators with the symbol z+p to be invertible on the Bergman space when all coefficients of p are real numbers.Furthermore,we establish several necessary and sufficient,easy-to-check conditions for Toeplitz operators with the symbol z+p to be invertible on the Bergman space when some coefficients of p are complex numbers. 展开更多
关键词 Bergman space Toeplitz operator harmonic polynomial symbol invertibility
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Virtual Synchronous Generator Control Strategy Based on Parameter Self-Tuning
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作者 Jin Lin BinYu +3 位作者 Chao Chen Jiezhen Cai Yifan Wu Cunping Wang 《Energy Engineering》 2026年第1期181-203,共23页
With the increasing integration of renewable energy,microgrids are increasingly facing stability challenges,primarily due to the lack of inherent inertia in inverter-dominated systems,which is traditionally provided b... With the increasing integration of renewable energy,microgrids are increasingly facing stability challenges,primarily due to the lack of inherent inertia in inverter-dominated systems,which is traditionally provided by synchronous generators.To address this critical issue,Virtual Synchronous Generator(VSG)technology has emerged as a highly promising solution by emulating the inertia and damping characteristics of conventional synchronous generators.To enhance the operational efficiency of virtual synchronous generators(VSGs),this study employs smallsignal modeling analysis,root locus methods,and synchronous generator power-angle characteristic analysis to comprehensively evaluate how virtual inertia and damping coefficients affect frequency stability and power output during transient processes.Based on these analyses,an adaptive control strategy is proposed:increasing the virtual inertia when the rotor angular velocity undergoes rapid changes,while strengthening the damping coefficient when the speed deviation exceeds a certain threshold to suppress angular velocity oscillations.To validate the effectiveness of the proposed method,a grid-connected VSG simulation platform was developed inMATLAB/Simulink.Comparative simulations demonstrate that the proposed adaptive control strategy outperforms conventional VSGmethods by significantly reducing grid frequency deviations and shortening active power response time during active power command changes and load disturbances.This approach enhances microgrid stability and dynamic performance,confirming its viability for renewable-dominant power systems.Future work should focus on experimental validation and real-world parameter optimization,while further exploring the strategy’s effectiveness in improvingVSG low-voltage ride-through(LVRT)capability and power-sharing applications in multi-parallel configurations. 展开更多
关键词 New power system grid-connected inverter virtual synchronous generator(VSG) virtual inertia damping coefficient adaptive control
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Efficient and stable inverted perovskite solar cells employing self-assembled hole-transporting monolayers with enhanced interface interaction
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作者 Botong Li Jie Liu +11 位作者 Boyang Lu Xuepeng Liu Mingyuan Han Weilun Du Ziqiang Su Zedong Lin Wenyong Feng Lei Xiao Zhipeng Shao Yong Ding Songyuan Dai Mohammad Khaja Nazeeruddin 《Journal of Energy Chemistry》 2026年第1期712-719,I0016,共9页
Molecular tailoring of self-assembled hole-transporting monolayers(SAMs)has been proven as an efficient approach for improving the device performance of inverted perovskite solar cells.Herein,a novel SAM with extended... Molecular tailoring of self-assembled hole-transporting monolayers(SAMs)has been proven as an efficient approach for improving the device performance of inverted perovskite solar cells.Herein,a novel SAM with extended conjugation is designed and synthesized,named NaPh-4PACz.Compared to Ph-4PACz,NaPh-4PACz exhibits a larger adsorption energy with the ITO substrate,enabling the formation of a more uniform and dense film,thereby preventing direct contact between the perovskite and ITO.Additionally,NaPh-4PACz also has a stronger interaction with the perovskite,which can reduce buried interface defects and suppress non-radiative recombination.Consequently,NaPh-4PACz-based devices achieved a power conversion efficiency of 25.48%due to their interfacial“adhesive”ability.Importantly,the stability of the NaPh-4PACz-based devices was significantly improved. 展开更多
关键词 Inverted perovskite solar cells Self-assembled monolayer Hole transport layer Extended conjugation NaPh-4PACz
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Characteristics of gallium oxide nMOSFET inverter
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作者 Yixin Zhang Haifeng Chen +4 位作者 Zijie Ding Yuduo Zhang Qin Lu Xiangtai Liu Yunhe Guan 《Journal of Semiconductors》 2026年第2期45-50,共6页
β-Ga_(2)O_(3) MOS inverter should play a crucial role in β-Ga_(2)O_(3) electronic circuits. Enhancement-mode(E-mode) MOSFET was fabricated based on β-Ga_(2)O_(3) film grown by atomic layer deposition technology, an... β-Ga_(2)O_(3) MOS inverter should play a crucial role in β-Ga_(2)O_(3) electronic circuits. Enhancement-mode(E-mode) MOSFET was fabricated based on β-Ga_(2)O_(3) film grown by atomic layer deposition technology, and the β-Ga_(2)O_(3) inverter was further monolithically integrated on this basis. The β-Ga_(2)O_(3) n MOSFET exhibits excellent electrical characteristics with an on/off current ratio reaching 10^(5). The logic inverter shows outstanding voltage inversion characteristics under low-frequency from 1 to 400 Hz operation. As the frequency continues to increase to 10 K, the reverse characteristic becomes worse due to parasitic capacitance induced by processes, and the difference between the highest and lowest values of VOUT has an exponential decay relationship with the frequency. This paper provides the practice for the development of β-Ga_(2)O_(3)-based circuits. 展开更多
关键词 ultra-wide bandgap Ga_(2)O_(3) MOSFET INVERTER
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High-Efficiency Perovskite/Silicon Tandem Solar Cells Based on Wide-Bandgap Perovskite Solar Cells with Unprecedented Fill Factor
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作者 Li-Chun Chang The Duong +23 位作者 Viqar Ahmad Hualin Zhan Anh Dinh Bui Jana-Isabelle Polzin Armin Richter Gabriel Bartholazzi Keqing Huang Zhongshu Yang Wei Wang Yihui Hou Li Li Qian Cui Rabin Basnet Jianfei Yang Hong Lin Guozheng Du Khoa Nguyen Dang-Thuan Nguyen Lachlan E.Black Daniel MacDonald Daniel Walter Klaus J.Weber Kylie R.Catchpole Heping Shen 《Nano-Micro Letters》 2026年第4期487-505,共19页
Recent progress in inverted perovskite solar cells(i PSCs)highlights the critical role of interface engineering between the charge transport layer and perovskite.Self-assembled monolayers(SAM)on transparent conductive... Recent progress in inverted perovskite solar cells(i PSCs)highlights the critical role of interface engineering between the charge transport layer and perovskite.Self-assembled monolayers(SAM)on transparent conductive oxide electrodes serve effectively as hole transport layers,though challenges such as energy mismatches and surface inhomogeneities remain.Here,a blended self-assembled monolayer of(2-(9H-carbazol-9-yl)ethyl)phosphonic acid(2PACz)and(4-(3,6-Dimethyl-9H-carbazol-9-yl)butyl)phosphonic acid(Me-4PACz)is developed,offering improved surface potential uniformity and interfacial energy alignment compared to individual SAMs.Interactions between the SAMs and ionic species are investigated with simulation analysis conducted,revealing the elimination of interfacial energy barriers through precise energy-level tuning.This strategy enables wide-bandgap(1.67 e V)perovskite solar cells with inverted structures with over 24%efficiency,an open-circuit voltage(V_(oc))of 1.268 V,and a certified fill factor(FF)of 86.8%,leading to a certified efficiency of 23.42%.The approach also enables high-efficiency semi-transparent devices and a mechanically stacked four-terminal perovskite/silicon tandem solar cell reaching 30.97%efficiency. 展开更多
关键词 Inverted perovskite solar cells Self-assembled monolayers Interface energy-level alignment Wide-bandgap perovskite Tandem solar cells
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