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The(Homotopy)Fixed Point Set of S^(1)-Actions on Rationally Elliptic 4-Manifolds
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作者 Chen Huimin Liu Xiugui 《南开大学学报(自然科学版)》 北大核心 2025年第3期32-37,共6页
Let X be a closed simply connected rationally elliptic 4-manifold.The rational homotopy type of homotopy fixed point sets X^(hS^(1))is determined,and based on some relations between X^(hS^(1))and X^(S^(1)),the rationa... Let X be a closed simply connected rationally elliptic 4-manifold.The rational homotopy type of homotopy fixed point sets X^(hS^(1))is determined,and based on some relations between X^(hS^(1))and X^(S^(1)),the rational homotopy type of the fixed point set X^(S^(1))is determined. 展开更多
关键词 rationally elliptic 4-manifolds rational homotopy type homotopy fixed point set fixed point set
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Coincidence Point and Common Fixed Point Theorems on b-Metric-like Spaces
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作者 LUO Ting 《应用数学》 北大核心 2025年第3期831-840,共10页
In this paper,we establish common fixed point theorems for expansive map?pings on b-metric-like space and coincidence point for f-weakly isotone increasing mappings in partially ordered b-metric-like space.The main re... In this paper,we establish common fixed point theorems for expansive map?pings on b-metric-like space and coincidence point for f-weakly isotone increasing mappings in partially ordered b-metric-like space.The main results generalize and extend several well-known comparable results from the existing literature.Moreover,some examples are provided to illustrate the main results. 展开更多
关键词 b-metric-like space Partially ordered b-metric-like space Expansive mapping f-weakly isotone mapping Coincidence point Common fixed point
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Fractional Discrete-Time Analysis of an Emotional Model Built on a Chaotic Map through the Set of Equilibrium and Fixed Points
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作者 Shaher Momani Rabha W.Ibrahim Yeliz Karaca 《Computer Modeling in Engineering & Sciences》 2025年第4期809-826,共18页
Fractional discrete systems can enable the modeling and control of the complicated processes more adaptable through the concept of versatility by providing systemdynamics’descriptions withmore degrees of freedom.Nume... Fractional discrete systems can enable the modeling and control of the complicated processes more adaptable through the concept of versatility by providing systemdynamics’descriptions withmore degrees of freedom.Numerical approaches have become necessary and sufficient to be addressed and employed for benefiting from the adaptability of such systems for varied applications.A variety of fractional Layla and Majnun model(LMM)system kinds has been proposed in the current work where some of these systems’key behaviors are addressed.In addition,the necessary and sufficient conditions for the stability and asymptotic stability of the fractional dynamic systems are investigated,as a result of which,the necessary requirements of the LMM to achieve constant and asymptotically steady zero resolutions are provided.As a special case,when Layla and Majnun have equal feelings,we propose an analysis of the system in view of its equilibrium and fixed point sets.Considering that the system has marginal stability if its eigenvalues have both negative and zero real portions,it is demonstrated that the system neither converges nor diverges to a steady trajectory or equilibrium point.It,rather,continues to hover along the line separating stability and instability based on the fractional LMM system. 展开更多
关键词 Fractional difference system fractional differential operators fractional calculus chaotic map EQUILIBRIUM fixed point sets nyquist plot routh-Hurwitz criterion
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MEMS microwave power detection chip based on fixed beams and its model
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作者 Qirui Xu Zhiyin Ding Debo Wang 《Journal of Semiconductors》 2025年第6期87-95,共9页
In order to solve the problems of low overload power in MEMS cantilever beams and low sensitivity in traditional MEMS fixed beams,a novel MEMS microwave power detection chip based on the dual-guided fixed beam is desi... In order to solve the problems of low overload power in MEMS cantilever beams and low sensitivity in traditional MEMS fixed beams,a novel MEMS microwave power detection chip based on the dual-guided fixed beam is designed.A gap between guiding beams and measuring electrodes is designed to accelerate the release of the sacrificial layer,effectively enhanc-ing chip performance.A load sensing model for the MEMS fixed beam microwave power detection chip is proposed,and the mechanical characteristics are analyzed based on the uniform load applied.The overload power and sensitivity are investi-gated using the load sensing model,and experimental results are compared with theoretical results.The detection chip exhibits excellent microwave characteristic in the 9-11 GHz frequency band,with a return loss less than-10 dB.At a signal fre-quency of 10 GHz,the theoretical sensitivity is 13.8 fF/W,closely matching the measured value of 14.3 fF/W,with a relative error of only 3.5%.These results demonstrate that the proposed load sensing model provides significant theoretical support for the design and performance optimization of MEMS microwave power detection chips. 展开更多
关键词 detection chip dual-guided fixed beam MEMS load sensing model sensitivity
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Fixed Neural Network Image Steganography Based on Secure Diffusion Models
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作者 Yixin Tang Minqing Zhang +2 位作者 Peizheng Lai Ya Yue Fuqiang Di 《Computers, Materials & Continua》 2025年第9期5733-5750,共18页
Traditional steganography conceals information by modifying cover data,but steganalysis tools easily detect such alterations.While deep learning-based steganography often involves high training costs and complex deplo... Traditional steganography conceals information by modifying cover data,but steganalysis tools easily detect such alterations.While deep learning-based steganography often involves high training costs and complex deployment.Diffusion model-based methods face security vulnerabilities,particularly due to potential information leakage during generation.We propose a fixed neural network image steganography framework based on secure diffu-sion models to address these challenges.Unlike conventional approaches,our method minimizes cover modifications through neural network optimization,achieving superior steganographic performance in human visual perception and computer vision analyses.The cover images are generated in an anime style using state-of-the-art diffusion models,ensuring the transmitted images appear more natural.This study introduces fixed neural network technology that allows senders to transmit only minimal critical information alongside stego-images.Recipients can accurately reconstruct secret images using this compact data,significantly reducing transmission overhead compared to conventional deep steganography.Furthermore,our framework innovatively integrates ElGamal,a cryptographic algorithm,to protect critical information during transmission,enhancing overall system security and ensuring end-to-end information protection.This dual optimization of payload reduction and cryptographic reinforcement establishes a new paradigm for secure and efficient image steganography. 展开更多
关键词 Image steganography fixed neural network secure diffusion models ELGAMAL
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Relativistic non-Fermi liquid fixed point in(2+1)-dimensional birefringent Dirac fermions interacting with electromagnetic fields
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作者 Wan-Zi Sun Kai Liu +1 位作者 Wu-Ming Liu Cheng-Xi Li 《Chinese Physics B》 2025年第5期524-532,共9页
The system consisting of(2+1)-dimensional quasirelativistic birefringent Dirac fermions with Coulomb interactions and retarded current–current interactions is described by a quantum field theory similar to reduced qu... The system consisting of(2+1)-dimensional quasirelativistic birefringent Dirac fermions with Coulomb interactions and retarded current–current interactions is described by a quantum field theory similar to reduced quantum electrodynamics.We used the perturbative renormalization group method to study the low-energy behavior of the system and found that it flows to a fixed point of the non-Fermi liquid composed of relativistic pseudospin-1/2 Dirac fermions in the deep infrared limit.At the fixed point,the fermion Green function exhibits a finite anomalous dimension,and the residue of the quasiparticle pole vanishes in a power-law fashion.Our research provides new theoretical perspectives for understanding the origin of spin-1/2 fermions in the standard model. 展开更多
关键词 non-Fermi liquid fixed point birefringent Dirac fermions perturbative renormalization group Fermi velocity renormalization
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Fixed point results for asymptotically regular mappings in abstract metric spaces
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作者 HAN Yan DAI Ting-ting XU Shao-yuan 《Applied Mathematics(A Journal of Chinese Universities)》 2025年第3期632-644,共13页
In this paper,various extended contractions are introduced as generalizations of some existing contractions given by Kannan,Ciric,Reich and Gornicki,et al.Then,several meaningful results about asymptotically regular m... In this paper,various extended contractions are introduced as generalizations of some existing contractions given by Kannan,Ciric,Reich and Gornicki,et al.Then,several meaningful results about asymptotically regular mappings in cone metric spaces over Banach algebras are obtained,weakening the completeness of the spaces and the continuity of the mappings.Moreover,some nontrivial examples are showed to verify the innovation of the new concepts and our fxed point theorems. 展开更多
关键词 asymptotic regularity fixed point cone metric spaces over Banach algebras
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Wind disturbance compensated path-following control for fixed-wing UAVs in arbitrarily strong winds 被引量:1
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作者 Hao LU Lan GAO +2 位作者 Yunda YAN Mingzhe HOU Chenliang WANG 《Chinese Journal of Aeronautics》 SCIE EI CAS CSCD 2024年第2期431-445,共15页
Wind is the primary challenge for low-speed fixed-wing unmanned aerial vehicles to follow a predefined flight path.To cope with various wind conditions,this paper proposes a wind disturbance compensated path following... Wind is the primary challenge for low-speed fixed-wing unmanned aerial vehicles to follow a predefined flight path.To cope with various wind conditions,this paper proposes a wind disturbance compensated path following control strategy where the wind disturbance estimate is incorporated with the nominal guiding vector field to provide the desired airspeed direction for the inner-loop.Since the control input vector for the outer-loop kinematic subsystem needs to satisfy a magnitude constraint,a scaling mechanism is introduced to tune the proportions of the compensation and nominal components.Moreover,an optimization problem is formulated to pursue a maximum wind compensation in strong winds,which can be solved analytically to yield two scaling factors.A cascaded inner-loop tracking controller is also designed to fulfill the outer-loop wind disturbance compensated guiding vector field.High-fidelity simulation results under sensor noises and realistic winds demonstrate that the proposed path following algorithm is less sensitive to sensor noises,achieves promising accuracy in normal winds,and mitigates the deviation from a desired path in wild winds. 展开更多
关键词 Path following Guiding vector field Wind disturbance Disturbance rejection fixed wings
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Secure Tracking Control via Fixed-Time Convergent Reinforcement Learning for a UAV CPS 被引量:1
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作者 Zhenyu Gong Feisheng Yang 《IEEE/CAA Journal of Automatica Sinica》 SCIE EI CSCD 2024年第7期1699-1701,共3页
Dear Editor,This letter is concerned with the secure tracking control problem in the unmanned aerial vehicle(UAV) system by fixed-time convergent reinforcement learning(RL). By virtue of the zero-sum game,the false da... Dear Editor,This letter is concerned with the secure tracking control problem in the unmanned aerial vehicle(UAV) system by fixed-time convergent reinforcement learning(RL). By virtue of the zero-sum game,the false data injection(FDI) attacker and secure controller are viewed as game players. 展开更多
关键词 SECURE fixed false
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Fixed-Time Consensus-Based Nash Equilibrium Seeking
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作者 Mengwei Sun Jian Liu +1 位作者 Lu Ren Changyin Sun 《IEEE/CAA Journal of Automatica Sinica》 SCIE EI CSCD 2024年第1期267-269,共3页
Dear Editor,This letter examines the fixed-time stability of the Nash equilibrium(NE)in non-cooperative games.We propose a consensus-based NE seeking algorithm for situations where players do not have perfect informat... Dear Editor,This letter examines the fixed-time stability of the Nash equilibrium(NE)in non-cooperative games.We propose a consensus-based NE seeking algorithm for situations where players do not have perfect information and communicate via a topology graph.The proposed algorithm can achieve NE in a fixed time that does not depend on initial conditions and can be adjusted in advance. 展开更多
关键词 fixed SEEKING LETTER
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Effect of the Particle Packing Configuration on Fixed Bed Performance
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作者 Li Ziqi Bao Di +1 位作者 Zhou Han Tang Xiaojin 《China Petroleum Processing & Petrochemical Technology》 SCIE CAS CSCD 2024年第1期152-160,共9页
Fixed-bed reactors are generally considered the optimal choice for numerous multi-phase catalytic reactions due to their excellent performance and stability.However,conventional fixed beds often encounter challenges r... Fixed-bed reactors are generally considered the optimal choice for numerous multi-phase catalytic reactions due to their excellent performance and stability.However,conventional fixed beds often encounter challenges related to inadequate mass transfer and a high pressure drop caused by the non-uniform void fraction distribution.To enhance the overall performance of fixed beds,the impact of different packing configurations on performance was investigated.Experimental and simulation methods were used to investigate the fluid flow and mass transfer performances of various packed beds under different flow rates.It was found that structured beds exhibited a significantly lower pressure drop per unit length than conventional packed beds.Furthermore,the packing configurations had a critical role in improving the overall performance of fixed beds.Specifically,structured packed beds,particularly the H-2 packing configuration,effectively reduced the pressure drop per unit length and improved the mass transfer efficiency.The H-2 packing configuration consisted of two parallel strips of particles in each layer,with strips arranged perpendicularly between adjacent layers,and the spacing between the strips varied from layer to layer. 展开更多
关键词 packing configurations fixed bed Computational Fluid Dynamics simulation pressure drop mass transfer
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Hierarchical Reinforcement Learning Adversarial Algorithm Against Opponent with Fixed Offensive Strategy
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作者 赵英策 张广浩 +1 位作者 邢正宇 李建勋 《Journal of Shanghai Jiaotong university(Science)》 EI 2024年第3期471-479,共9页
Based on option-critic algorithm,a new adversarial algorithm named deterministic policy network with option architecture is proposed to improve agent's performance against opponent with fixed offensive algorithm.A... Based on option-critic algorithm,a new adversarial algorithm named deterministic policy network with option architecture is proposed to improve agent's performance against opponent with fixed offensive algorithm.An option network is introduced in upper level design,which can generate activated signal from defensive and of-fensive strategies according to temporary situation.Then the lower level executive layer can figure out interactive action with guidance of activated signal,and the value of both activated signal and interactive action is evaluated by critic structure together.This method could release requirement of semi Markov decision process effectively and eventually simplified network structure by eliminating termination possibility layer.According to the result of experiment,it is proved that new algorithm switches strategy style between offensive and defensive ones neatly and acquires more reward from environment than classical deep deterministic policy gradient algorithm does. 展开更多
关键词 hierarchical reinforcement learning fixed offensive strategy option architecture deterministic gradi-entpolicy
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Advancements in Fixed Point Theorems forα-Geraghty Contractions in Complete Metric Space
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作者 V.C.BORKAR Mohammed M.A.TALEB Saeed A.A.AL-SALEHI 《Journal of Mathematical Research with Applications》 CSCD 2024年第5期697-710,共14页
This article improves and advances the results achieved by Vishal and Naveen,leveraging the use of Lebesgue integrable functions.Going beyond,we investigate fixed point theorems associated with a concept introduced by... This article improves and advances the results achieved by Vishal and Naveen,leveraging the use of Lebesgue integrable functions.Going beyond,we investigate fixed point theorems associated with a concept introduced by Ovidiu Popescu.Our research not only bolsters the theoretical framework but also unveils practical applications in the domain of Lebesgue integrals as in Example 3.6.Furthermore,our contribution enhances the understanding of fixed point theorems in metric spaces and introduces novel perspectives in the study of generalizedα-Geraghty contractive mappings on Lebesgue integrals. 展开更多
关键词 fixed point theorems contractive mappings α-Geraghty contractions complete metric spaces Lebesgue integrals α-admissible α-orbital α-orbital attractive
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Common Fixed Points for Multiplicative Contractions in Multiplicative Metric Spaces
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作者 SONG Jiping LUO Tianqi LEI Lei 《Wuhan University Journal of Natural Sciences》 CAS CSCD 2024年第1期13-20,共8页
The study delves into multiplicative contractions,exploring the existence and uniqueness of common fixed points for a weakly compatible pair of mappings.Those mappings adhere to specific multiplicative contraction con... The study delves into multiplicative contractions,exploring the existence and uniqueness of common fixed points for a weakly compatible pair of mappings.Those mappings adhere to specific multiplicative contraction conditions characterized by exponents expressed as fraction multiplicative metric spaces.It is noted that a metric can induce a multiplicative metric,and conversely,a multiplicative metric can give a rise to a metric on a nonempty set.As an application,another proof of the existence and uniqueness of the solution of a multiplicative initial problem is given. 展开更多
关键词 weakly compatible pair of mappings common fixed point multiplicative metric space
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The Generalized Fixed Point Iteration Method for AVE
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作者 Changfeng MA Jing KANG 《Journal of Mathematical Research with Applications》 CSCD 2024年第6期837-849,共13页
In this paper,based on the previous published work by Ke et al.(2019)and Li et al.(2022),by using the matrix splitting technique,generalized fixed point iteration method(GFPI)is established to solve the absolute value... In this paper,based on the previous published work by Ke et al.(2019)and Li et al.(2022),by using the matrix splitting technique,generalized fixed point iteration method(GFPI)is established to solve the absolute value equation(AVE).The proposed method not only includes SOR-like method,FPI method,MFPI method and so on,but also generates some special versions.Some convergence conditions of the proposed method with different iteration error norms are presented.Furthermore,methods corresponding to other splitting methods are studied in detail.The effectiveness and feasibility of the proposed method are confirmed by some numerical experiments. 展开更多
关键词 absolute value equations fixed point iteration CONVERGENCE
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Simultaneous Adsorption of Aqueous Pb2+, Cu2+, Zn2+, and Cd2+ Using Surfactant-Modified and Unmodified Activated Carbon in a Fixed Bed Column
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作者 Morufu A. Olatunji Kamoru A. Salam Abdullahi M. Evuti 《Journal of Encapsulation and Adsorption Sciences》 2024年第1期1-24,共24页
The goal of this work is to improve the simultaneous removal of Pb2+, Cu2+, Zn2+, and Cd2+ ions from synthetic wastewater in a fixed bed column by incorporating sodium dodecyl sulfate (SDS) onto the surface of activat... The goal of this work is to improve the simultaneous removal of Pb2+, Cu2+, Zn2+, and Cd2+ ions from synthetic wastewater in a fixed bed column by incorporating sodium dodecyl sulfate (SDS) onto the surface of activated carbon made from coconut shells. The activated carbons were characterized using Fourier transform infrared spectroscopy (FT-IR) and scanning electron microscopy-energy dispersive x-ray (SEM-EDX). The adsorption column dynamics were studied by varying the flow rates (5, 10 and 15 mL/min), bed heights (10, 15 and 20 cm), and initial concentrations (50, 150, and 250 mg/L). The activated carbon has a pore volume of 0.715 cm3/g and a BET-specific surface area of 1410 m2/g. Sodium dodecyl sulfate (SDS) surfactant incorporation onto the surface of the activated carbon enhances its capacity for simultaneous adsorption of Pb2+, Cu2+, Zn2+, and Cd2+ from the aqueous medium. The affinity of the heavy metals to both unmodified (AC) and modified (AC-SDS) activated carbons followed the order of Pb2+ > Cu2+ > Zn2+ > Cd2+. The dynamic adsorption of the column depends on the flow rate, bed height, initial metal concentration, and SDS surface modification. With a 5 mL/min flow rate, a 20 cm bed height, and a 50 mg/L initial metal concentration, a maximum break-through time of 150 minutes for the unmodified activated carbon (AC) and 180 minutes for the SDS-modified activated carbon (AC-SDS) was reached. 展开更多
关键词 ADSORPTION Surfactant-Modified Activated Carbon Multicomponent Breakthrough Adsorption Capacity fixed Bed Column
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Correction to:An Efficient Randomized Fixed-Precision Algorithm for Tensor Singular Value Decomposition
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作者 Salman Ahmadi-Asl 《Communications on Applied Mathematics and Computation》 2024年第4期2332-2335,共4页
Correction to:Communications on Applied Mathematics and Computation(2023)5:1564-1583 https://doi.0rg/10.1007/s42967-022-00218-w Regretfully,due to technical issues encountered during the proofreading process,certain p... Correction to:Communications on Applied Mathematics and Computation(2023)5:1564-1583 https://doi.0rg/10.1007/s42967-022-00218-w Regretfully,due to technical issues encountered during the proofreading process,certain portions of our published paper[1]include some inconsistencies.To dispel any confusion for the readers,we decided to address these technical problems.The corrected version was uploaded on arXiv https://arxiv.org/abs/2207.08307 and the codes are accessible at https://github.com/SalmanAhmadi-Asl/Fixed-Precision-t-SVD.Here are the corrections. 展开更多
关键词 PROBLEMS fixed PROOF
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A Study on the Internal Control and Countermeasures of Fixed Assets in Private Universities:A Case Study of N College
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作者 Guirong Ma Lili Ma 《Proceedings of Business and Economic Studies》 2024年第4期86-92,共7页
Fixed assets in universities occupy an important position in university management due to their wide coverage and large amount of money.Due to insufficient funding supply,private universities mainly focus on the alloc... Fixed assets in universities occupy an important position in university management due to their wide coverage and large amount of money.Due to insufficient funding supply,private universities mainly focus on the allocation and utilization of fixed assets,which reflects the overall characteristics of cautious allocation,maximum utilization,and delayed elimination in the actual management of fixed assets.This article aims to conduct research and analysis on the entire lifecycle process of the allocation,use,and disposal of fixed assets in private universities,summarize the problems existing in the internal control of fixed assets in private universities,and propose corresponding countermeasures and suggestions in a targeted manner. 展开更多
关键词 Private universities fixed assets Internal control and countermeasures
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CARISTI TYPE HYBRID FIXED POINT THEOREMS IN MENGERPROBABILISTIC METRIC SPACE
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作者 石川 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 1997年第2期201-209,共9页
This paper brings forward the concept of Caristi type hybrid fixed point in M-PM-space, by giving two hybrid fixed point theorems and two common hybrid fixed point theorems of sequences of set-valued mappings, the the... This paper brings forward the concept of Caristi type hybrid fixed point in M-PM-space, by giving two hybrid fixed point theorems and two common hybrid fixed point theorems of sequences of set-valued mappings, the theorems improve and generalize the Caristi's fixed point and correspond to recent important results. 展开更多
关键词 probabilistic metric space Menger space Caristi's fixed point theorem hybrid fixed point common hybrid fixed point
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Integrated Guidance and Control of Homing Missiles Against Ground Fixed Targets 被引量:23
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作者 侯明哲 段广仁 《Chinese Journal of Aeronautics》 SCIE EI CAS CSCD 2008年第2期162-168,共7页
This paper presents a scheme of integrated guidance and autopilot design for homing missiles against ground fixed targets. An integrated guidance and control model in the pitch plane is formulated and further changed ... This paper presents a scheme of integrated guidance and autopilot design for homing missiles against ground fixed targets. An integrated guidance and control model in the pitch plane is formulated and further changed into a normal form by nonlinear coordinate transformation. By adopting the sliding mode control approach, an adaptive nonlinear control law of the system is designed so that the missile can hit the target accurately with a desired impact attitude angle. The stability analysis of the closed-loop system is also conducted. The numerical simulation has confirmed the usefulness of the proposed design scheme. 展开更多
关键词 integrated guidance and control pitch plane ground fixed target nonlinear adaptive
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