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[IEEE 2018 IEEE PELS Workshop on Emerging Technologies: Wireless Power Transfer (WoW) - Montréal, QC, Canada (2018.6.3-2018.6.7)] 2018 IEEE PELS Workshop on Emerging Technologies: Wireless Power Transfer (Wow) - Study of Bifurcation Evaluation Method for IPT
摘要： The inductive power transfer (IPT) is negatively affected by the bifurcation. Current methods for IPT analysis are general, not designated for the bifurcation analysis – they may be cumbersome or not effective enough. The proposed method describes device operating point (OP) by a combination of load quality factors. The OP is plotted in a diagram and based on its position towards the bifurcation boundary, the bifurcation occurs. Multiple OP joined together to form an operating trajectory suitable for a process evaluation or an operating area, suitable for parameter range analysis in the device design.
关键词： bifurcation analysis,bifurcation,inductive power transfer
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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[IEEE 2018 IEEE International Conference on Imaging Systems and Techniques (IST) - Krakow (2018.10.16-2018.10.18)] 2018 IEEE International Conference on Imaging Systems and Techniques (IST) - An OCTA Based Diagnosis System Based on a Comprehensive Local Features Analysis for Early Diabetic Retinopathy Detection
摘要： In this work, we propose a comprehensive diagnosis system for detecting early signs of diabetic retinopathy (DR). The proposed system is based on extracting features that are describing both shape and appearance of the retinal vascular system from optical coherence tomography angiography (OCTA) scans. First, two various OCTA plexuses are segmented, which are retinal super?cial and deep plexuses, to extract the retinal blood vessels from the other background tissues. Then, the developed system calculates the blood vessels density, blood vessels caliber, and distance map of the foveal avascular zone (FAZ) from both two segmented OCTA plexuses. Also, the large blood vessels are extracted from the segmented super?cial plexus to retrieve the skeleton of the blood vessels. The skeleton of the large blood vessels is used to calculate bifurcation, crossover, and branch points. Finally, the extracted four features that are capturing shape and appearance of the segmented vessels and FAZ, which are blood vessels density, blood vessel caliber, the width of the FAZ, and different types of vascular bifurcation points are used to diagnosis the OCTA images by using two-stage random forest (RF) classi?er. To measure the performance of the proposed system, 133 OCTA scans for different patients are used for training and testing based on k-fold cross-validation technique. The performance of the proposed system is measured by using ?ve various metrics. A promising average result of overall accuracy (ACC) of 97% is obtained that can differentiate normal from mild DR cases.
关键词： Early DR Diagnosis,OCTA,FAZ,Local Retinal Blood Vessels Analysis,Bifurcation
更新于2025-09-23 15:22:29
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Nonlinear bifurcation diagrams of the current states of microcavity exciton-polaritons in the lattice
摘要： We study nonequilibrium properties of exciton-polaritons in an incoherently driven semiconductor microcavity with an embedded weak-contrast periodic lattice. Within the framework of mean-field theory, we describe nonlinear eigenstates of coherent exciton polaritons having the structure of Bloch waves and identify nonlinear current states at the boundaries of Brillouin zone. We demonstrate a profound modification of the eigenfrequency-momenta bifurcation diagrams of the condensate evoked by exciton-exciton interactions. The discussed phenomenon occurs for the states possessing high degree of symmetry, i.e. in particular, for the states lying at the centre or at the boundary of Brillouin zone.
关键词： exciton-polaritons,semiconductor microcavity,Bloch waves,nonlinear bifurcation,Brillouin zone
更新于2025-09-23 15:21:21
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Amplitude modulation and soliton formation of an intense laser beam interacting with dense quantum plasma: Symbolic simulation analysis
摘要： In this theoretical study, we investigate the amplitude modulation and envelop soliton formation in a dense plasma when such a plasma interacts with a strong laser beam. We have made use of the symbolic simulation technique to find the modulation instability of an electrostatic wave with higher orders of non-linearity. We identified the range of wavenumber in which such non-linearity is important. Furthermore, we have analysed the formation of envelope soliton of waves localized in space. The results obtained here will be helpful in interpreting different phenomena that arise in laser plasma interaction. The importance of the relativistic contribution of streaming particles is discussed alongside the parametric influences experienced by the plasma particles.
关键词： homotopy perturbation,quantum plasma,symbolic simulation,bifurcation,instability
更新于2025-09-23 15:21:01
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Existence of stationary fronts in a system of two coupled wave equations with spatial inhomogeneity
摘要： We investigate the existence of stationary fronts in a coupled system of two sine-Gordon equations with a smooth, ‘hat-like’ spatial inhomogeneity. The spatial inhomogeneity corresponds to a spatially dependent scaling of the sine-Gordon potential term. The uncoupled inhomogeneous sine-Gordon equation has stable stationary front solutions that persist in the coupled system. Carrying out a numerical investigation it is found that these inhomogeneous sine-Gordon fronts loose stability, provided the coupling between the two inhomogeneous sine-Gordon equations is strong enough, with new stable fronts bifurcating. In order to analytically study the bifurcating fronts, we first approximate the smooth spatial inhomogeneity by a piecewise constant function. With this approximation, we prove analytically the existence of a pitchfork bifurcation. To complete the argument, we prove that transverse fronts for a piecewise constant inhomogeneity persist for the smooth ‘hat-like’ spatial inhomogeneity by introducing a fast-slow structure and using geometric singular perturbation theory.
关键词： sine-Gordon front,coupled inhomogeneous wave equations,existence,geometric singular perturbation theory,bifurcation analysis
更新于2025-09-23 15:19:57
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[IEEE 2019 IEEE International Electron Devices Meeting (IEDM) - San Francisco, CA, USA (2019.12.7-2019.12.11)] 2019 IEEE International Electron Devices Meeting (IEDM) - Silicon nitride waveguide coupled 67+ GHz Ge photodiode for non-SOI PIC and ePIC platforms
摘要： As a major application domain of vascular ultrasound, the carotid artery has long been the subject of anthropomorphic phantom design. It is nevertheless not trivial to develop walled carotid phantoms that are compatible for use in integrative imaging of carotid wall motion and flow dynamics. In this paper, we present a novel phantom design protocol that can enable efficient fabrication of walled carotid bifurcation phantoms with: 1) high acoustic compatibility; 2) artery-like vessel elasticity; and 3) stenotic narrowing feature. Our protocol first involved direct fabrication of the vessel core and an outer mold using computer-aided design tools and 3-D printing technology; these built parts were then used to construct an elastic vessel tube through investment casting of a polyvinyl alcohol containing mixture, and an agar-gelatin tissue mimicking slab was formed around the vessel tube. For demonstration, we applied our protocol to develop a set of healthy and stenosed (25%, 50%, and 75%) carotid bifurcation phantoms. Plane wave imaging experiments were performed on these phantoms using an ultrasound scanner with channel-level configurability. Results show that the wall motion dynamics of our phantoms agreed with pulse wave propagation in an elastic vessel (pulse wave velocity of 4.67 ± 0.71 m/s measured at the common carotid artery), and their flow dynamics matched the expected ones in healthy and stenosed bifurcation (recirculation and flow jet formation observed). Integrative imaging of vessel wall motion and blood flow dynamics in our phantoms was also demonstrated, from which we observed fluid-structure interaction differences between healthy and diseased bifurcation phantoms. These findings show that the walled bifurcation phantoms developed with our new protocol are useful in vascular imaging studies that individually or jointly assess wall motion and flow dynamics.
关键词： carotid bifurcation phantom,vessel wall motion,integrative imaging,Blood flow dynamics
更新于2025-09-23 15:19:57
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Adaptive Pixel-Selection Fractional Chaotic Map Lattices for image cryptography
摘要： Chaotic theory has been employed in cryptography application for establishing a sequence of data closest to pseudorandom number. Image cryptography with Chaotic Map Lattices (CML) uses the chaos parameters, the number of iterations and the number of cycles for encryption as secret keys. Amount of secret keys has a great impact on security in cryptography. Adaptive Pixel-Selection Fractional Chaotic Map Lattices (APFCML) enhances the encryption security by introducing a novel non-integer fractional order concept as secret keys. Fractional chaos is modified chaos with a fractional differential equation containing derivatives of non-integer order. A non-integer order has an effect on the range of chaos's parameter. Moreover, the encryption sequence has been adaptively selected based on another chaos generator. In the experiments, the measurement indices of originality preservation, visual inspection, and statistical analysis are used to evaluate the performance of the proposed APFCML compared to that of the original CML.
关键词： fractional logistic,bifurcation diagram,image cryptography,Lyapunov exponent,Chaotic
更新于2025-09-23 15:19:57
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[IEEE 2018 IEEE SENSORS - New Delhi, India (2018.10.28-2018.10.31)] 2018 IEEE SENSORS - Smart Gas Sensing and Actuation Using Multimode of a MOFs Coated Microbeam
摘要： Smart sensing systems suffers complexity requiring interface circuits, microcontrollers, switches, and actuators to detect and sense, process the signal and take a decision, and trigger an action upon demand. This increases the device footprint and boosts significantly the power required to actuate the system. Here, we present a hybrid sensor and switch device, which is capable of accurately measuring gas concentration and perform switching when the concentration exceeds specific (safe) threshold. The device is based on a clamped-clamped microbeam coated with metal-organic frameworks (MOFs). Using the electrostatic harmonic voltage, we employ dynamic multi-modal actuation in which the microbeam is simultaneously excited at the first mode of vibration, near the pull-in band, and at the third mode. We demonstrate experimentally the effectiveness of this technique in measuring the concentration of water vapor and achieving switching when the concentration exceeds a threshold value. In contrast to a single mode operation, we show that employing multi-modal excitation improves sensitivity, enhances accuracy, and strengthen noise immunity.
关键词： Multi-modal,bifurcation,MOFs,Resonator,Smart sensor
更新于2025-09-19 17:15:36
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Stability of target waves in excitable media under electromagnetic induction and radiation
摘要： Local periodic stimulus can trigger stable pulse and target wave in the excitable media, the potential mechanism is that each cell is activated by continuous driving to keep pace with the external forcing. Indeed, local diversity in excitability and heterogeneity are induced when external forcing with diversity is applied on the media. When target wave is formed and propagated, the media will be modulated, e.g. it can emit electric signal from sinoatrial node and develops target wave in the cardiac tissue, and then the heartbeat is controlled completely. In fact, the distribution of electromagnetic field in the media is changed when external electric stimulus is applied on the media; therefore, the effect of electromagnetic induction becomes important during the information encoding and signal propagation. In this paper, the Morris-Lecar model is used to describe the local kinetic of the media and an induction current is considered thus the effect of electromagnetic induction can be described. Then the artificial heterogeneity is triggered to investigate the formation and development of target waves in the excitable media with electromagnetic induction and even radiation, which is described by using Gaussian white noise. Diversity in excitability and conductance of ion channels is considered, respectively, thus different kinds of artificial heterogeneity are developed to find the stability of target waves. It is found that the target wave encounters breakup with increasing of the intensity of electromagnetic radiation.
关键词： bifurcation,electromagnetic induction,memristor,target wave,ion channel
更新于2025-09-19 17:15:36