- 标题
- 摘要
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- 实验方案
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Cosine-transform-based chaotic system for image encryption
摘要： Chaos is known as a natural candidate for cryptography applications owing to its properties such as unpredictability and initial state sensitivity. However, certain chaos-based cryptosystems have been proven to exhibit various security defects because their used chaotic maps do not have complex dynamical behaviors. To address this problem, this paper introduces a cosine-transform-based chaotic system (CTBCS). Using two chaotic maps as seed maps, the CTBCS can produce chaotic maps with complex dynamical behaviors. For illustration, we produce three chaotic maps using the CTBCS and analyze their chaos complexity. Using one of the generated chaotic maps, we further propose an image encryption scheme. The encryption scheme uses high-efficiency scrambling to separate adjacent pixels and employs random order substitution to spread a small change in the plain-image to all pixels of the cipher-image. The performance evaluation demonstrates that the chaotic maps generated by the CTBCS exhibit substantially more complicated chaotic behaviors than the existing ones. The simulation results indicate the reliability of the proposed image encryption scheme. Moreover, the security analysis demonstrates that the proposed image encryption scheme provides a higher level of security than several advanced image encryption schemes.
关键词： Image privacy,Chaotic system,Image encryption,Cryptography,Security analysis,Chaos-based encryption
更新于2025-09-23 15:23:52
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Quantum Image Encryption Based on Henon Mapping
摘要： Quantum image processing has great significance as a branch of quantum computing. This paper gives a quantum image encryption based on Henon mapping, which breaks away from the restriction of classical computers and does the work in quantum computers end to end, including the generation of the chaos sequence, the encryption and the decryption. The algorithm is based on the GQIR quantum image representation model and the two-dimensional Henon chaotic mapping. However, the decimal sequence generated by Henon mapping can not be directly applied to quantum computers. Hence, we reform the Henon mapping by binary shift. The quantum image is encrypted by being XORed with the quantum Henon mapping. Simulation experiments indicate that the encrypted image has good radomness and the pixel values are evenly distributed. Since the chaotic sequence itself is suitable for image encryption, coupled with its own quantum confidentiality, the encryption method of this paper is safe, convenient and reliable.
关键词： Quantum image processing,Quantum computation,Henon mapping,Quantum image encryption,Chaos encryption
更新于2025-09-23 15:23:52
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Calcination-free synthesis of high strength self-cleaning anti-reflective MgF2-TiO2 coating
摘要： In order to understand the nonlinear dynamic behavior of a planar mechanism with clearance, the nonlinear dynamic model of the 2-DOF nine-bar mechanism with a revolute clearance is proposed; the dynamic response, phase diagrams, Poincar′e portraits, and largest Lyapunov exponents (LLEs) of mechanism are investigated. The nonlinear dynamic model of 2-DOF nine-bar mechanism containing a revolute clearance is established by using the Lagrange equation. Dynamic response of the slider’s kinematics characteristic, contact force, driving torque, shaft center trajectory, and the penetration depth for 2-DOF nine-bar mechanism are all analyzed. Chaos phenomenon existed in the mechanism has been identi?ed by using the phase diagrams, the Poincar′e portraits, and LLEs. The e?ects of the di?erent clearance sizes, di?erent friction coe?cients, and di?erent driving speeds on dynamic behavior are studied. Bifurcation diagrams with changing clearance value, friction coe?cient, and driving speed are drawn. The research could provide important technical support and theoretical basis for the further study of the nonlinear dynamics of planar mechanism.
关键词： Lyapunov exponent,nonlinear dynamics,chaos,clearance joint,bifurcation
更新于2025-09-23 15:23:52
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Data-driven uncertainty analysis of distribution networks including photovoltaic generation
摘要： This paper investigates residential distribution networks with uncertain loads and photovoltaic distributed generation. An original probabilistic modeling of consumer demand and photovoltaic generation is presented that is based on the analysis of large set of data measurements. It is shown how photovoltaic generation is described by complex non-standard distributions that can be described only numerically. Probabilistic analysis is performed using an enhanced version of the Polynomial Chaos technique that exploits a proper set of polynomial basis functions. It is described how such functions can be generated from the numerically available data. Compared to other approximate methods for probabilistic analysis, the novel technique has the advantages of modeling accurately truly nonlinear problems and of directly providing the detailed Probability Density Function of relevant observable quantities affecting the quality of service. Compared to standard Monte Carlo method, the proposed technique introduces a simulation speedup that depends on the number of random parameters. Numerical applications to radial and weakly meshed networks are presented where the method is employed to explore overvoltage, unbalance factor and power loss, as a function of photovoltaic penetration and/or network configuration.
关键词： Photovoltaic generation,Data-driven models,Polynomial chaos,Unbalanced distribution networks,Probabilistic load flow,Uncertainty Analysis
更新于2025-09-23 15:21:01
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A Technical Look at Fetoscopic Laser Ablation for Fetal Laryngeal Surgical Recanalization in Congenital High Airway Obstruction Syndrome
摘要： Background: Congenital high airway obstruction syndrome (CHAOS) is a rare condition characterized by complete obstruction of the upper fetal airways. Left untreated, it is uniformly fatal. Ex utero intrapartum treatment (EXIT) has been used to establish a surgical airway in affected fetuses during delivery. While this procedure bene?ts those fetuses that survive to delivery, high mortality in the prenatal period necessitates earlier innovative strategies. Herein, we report a novel technique for in utero intervention. Methods: A fetoscopic intervention was performed at 28 weeks on a 35-year-old G1P0 woman with fetal CHAOS from a laryngeal obstruction measuring 11 mm in length on prenatal imaging. Under ultrasound guidance, a 3.3-mm curved fetoscope was used to access the uterine cavity through a single subcentimeter maternal skin incision. The scope was driven through the fetal oral cavity and manipulated to attain a view of the vocal cords. A subglottic obstruction was observed. A 600-micron laser ?ber was passed through the working channel of the scope and used to ablate the obstructed airway. Using the laser ?ber and a guidewire, the ablated opening was traversed with the fetoscope to the level of the carina. Results: Postoperatively, the lungs became less hyperin?ated. There was improvement in ascites and diaphragmatic eversion. At 31 1/7 weeks’ gestation, the mother experienced preterm premature rupture of membranes with active labor and the fetus was delivered through EXIT to tracheostomy. The infant was managed on mechanical ventilation and is currently thriving at home with a tracheostomy at 2 years of age. Conclusion: Fetoscopy with laser ablation of the airway obstruction is an effective prenatal management strategy that offers the potential to alter the devastating natural course of CHAOS.
关键词： fetoscopy,in utero intervention,CHAOS,laser ablation
更新于2025-09-23 15:21:01
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WDM-based bidirectional chaotic communication for semiconductor lasers system with time delay concealment
摘要： In this paper, we propose a wavelength-division-multiplexing (WDM)-based chaos communication configuration allowing for the bidirectional exchange of information. In the scheme, the output of a master semiconductor laser (MSL), is injected into slave semiconductor lasers (SSLs), drives the chaotic synchronization of SSLs with optical feedback and electro-optical phase feedback. By calculating the largest Lyapunov exponent (LLE), Lempel–Ziv complexity (LZC) and permutation entropy (PE), we find that the system can generate the chaotic signal with high complexity. We also demonstrate that the chaotic signal bandwidth obtained is as high as 24.68 GHz by selecting the suitable parameters; this configuration intrinsically conceals the electro-optical phase feedback time delay signature (TDS) and optical feedback TDS in transmitted variable; this delayed chaotic dynamics are identically synchronized when the parameters of emitter are exactly matched with that of receiver; while the external and internal parameters’ mismatch between emitter and receiver can lead to the decrease of the synchronization quality. In addition, the result reveals that the channel spacing has influence on cross-correlation coefficient (XCF) quantifying synchronization quality. At last, the messages introduced at two ends of the link can be successfully encrypted and decrypted, and we quantitatively analyze the corresponding Q-factor at different transmission rates.
关键词： Semiconductor lasers,Optical chaos,Time delay signature concealment,All-optical network,bandwidth
更新于2025-09-23 15:21:01
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Encrypted Chaos in Quantum Dot Light Emitting Diode
摘要： A communication scheme based on the synchronization of two chaotic quantum dot light emitting diodes (QD-LEDs) is theoretically examined. The Chaos in the QD-LED is generated by means of an optical feedback. Synchronization of the chaos is achieved by varying coupling strength between the transmitter and the receiver as unidirectional coupling. The proposed communication schemes is test a by successfully transmitting messages.
关键词： chaos synchronization,optical feedback,QD-LED,communication
更新于2025-09-23 15:19:57
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AIP Conference Proceedings [AIP Publishing THE 7TH INTERNATIONAL CONFERENCE ON APPLIED SCIENCE AND TECHNOLOGY (ICAST 2019) - Karbala City, Iraq (27–28 March 2019)] THE 7TH INTERNATIONAL CONFERENCE ON APPLIED SCIENCE AND TECHNOLOGY (ICAST 2019) - Chaos synchronization in quantum dot semiconductor lasers with negative optoelectronic feedback
摘要： Chaos synchronization is investigated in quantum dot semiconductor lasers with negative optoelectronic feedback. Depending on the coupling strength between transmitter and receiver quantum dot semiconductor Laser. Synchronization happens when the coupling strength to the receiver matches the feedback strength to the transmitter, where the receiver output reproduces the output of the transmitter regardless of the presence of channel distortion or an encoded message. when feedback strength of transmitter, receiver quantum dot semiconductor Laser and coupling feedback strength are equal (- 0.3), time delay of transmitter, receiver quantum dot semiconductor Laser and coupling are sensitive to synchronization.
关键词： Chaos synchronization,Quantum dot semiconductor lasers,Negative optoelectronic feedback
更新于2025-09-23 15:19:57
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Complexity mapping of a photonic integrated circuit laser using a correlation-dimension-based approach
摘要： Quantifying complexity from experimental time series generated by nonlinear systems, including laser systems, remains a challenge. Methods that are based on entropy, such as permutation entropy (PE), have proven to be useful tools for the relative measure of time series complexity. However, the numerical value of PE is not readily linked to a specific type of dynamical output. Thus, the quest to calculate quantitatively meaningful fractal dimension values, such as the correlation dimension (CD), from experimental signals, is still important. A protocol for calculating minimum gradient values and their spread, an integral part of CD analysis, is used here. Minimum gradient values with small spread are presented as approximate CD values. Here-in we report mapping these values, derived from analyzing experimental time series, obtained from a 4-section photonic integrated circuit laser (PICL) across a large parameter space. The PICL is an integrated form of a semiconductor laser subject to controllable optical feedback system. The minimum gradient/approximate CD mapping shows it has some qualitatively different map regions in its dynamics as compared to a free-space-based equivalent system. We show that the minimum gradient values give insight into the dynamics even when approximate CD values cannot be determined. The agreement between the qualitative features of permutation entropy mapping and minimum gradient/approximate CD value mapping provides further support for this. Regions of time series with close to periodic and quasi-periodic dynamics are identifiable using minimum gradient value maps.
关键词： semiconductor lasers,integrated optoelectronic devices,nonlinear dynamics,complex systems,Chaos,complexity
更新于2025-09-23 15:19:57
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Two-dimensional optical chimera states in an array of coupled waveguide resonators
摘要： Two-dimensional arrays of coupled waveguides or coupled microcavities allow us to confine and manipulate light. Based on a paradigmatic envelope equation, we show that these devices, subject to a coherent optical injection, support coexistence between a coherent and incoherent emission. In this regime, we show that two-dimensional chimera states can be generated. Depending on initial conditions, the system exhibits a family of two-dimensional chimera states and interaction between them. We characterize these two-dimensional structures by computing their Lyapunov spectrum and Yorke–Kaplan dimension. Finally, we show that two-dimensional chimera states are of spatiotemporal chaotic nature.
关键词： Lyapunov spectrum,optical chimera states,Yorke–Kaplan dimension,spatiotemporal chaos,coupled waveguide resonators
更新于2025-09-23 15:19:57