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- 2018
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- photovoltaic (PV) power systems
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- two-inductor boost converter
- Electrical Engineering and Automation
- Sree Buddha College of Engineering
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[IEEE 2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC) - Munich, Germany (2019.6.23-2019.6.27)] 2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC) - Contrast of Visibility in Water and Air
摘要： A time-delay switch (TDS) attack on a control system is caused by adversaries that strategically imbed time delays into such systems. TDS attacks can make a control system, or more specifically a distributed power control system, unstable. Time delays can be introduced in the sensing loop (SL) or control lines. This paper describes a novel, simple, and effective method to thwart TDS attacks on SL. The proposed method works by augmenting the controller with a time-delay estimator to estimate any time delays. The modified controller controls the system under TDS attack. Also, the time-delay estimator will track time delays introduced by an adversary using a modified model reference control with an indirect supervisor and a modified least mean square minimization technique.
关键词： Time-delay switch attack,model reference control,time-delay estimation
更新于2025-09-19 17:13:59
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Simultaneous Generation of Two Types of Pulse Shape in an Yb-doped Fiber Laser System
摘要： One method of mitigating arc ?ash hazards associated with medium-voltage switchgear is the installation of active high-speed switch (HSS) systems. These systems are designed to detect and quench a burning internal arc in less than one-third of one electrical cycle. The internal arc is extinguished by the HSS’s action of redirecting the fault current path from arcing through open air back to the intended current path of the switchgear bus. The new low-impedance current path provided by the HSS operation collapses the voltage at the point of the fault to near zero so that the arc is no longer sustainable. The system’s high speed of operation compared to arc quenching via circuit breaker tripping translates directly to lower arc ?ash incident energy and minimal equipment damage. Another bene?t of such active high speed systems could include switchgear compliance to the IEEE C37.20.7 guide for testing arc-resistant metal-enclosed switchgear without any arc by-product venting requirements. This paper explores application considerations of HSS systems relative to other available means of controlling and reducing the hazards of internal arcing faults in medium-voltage switchgear.
关键词： arcing fault,high-speed switch (HSS),bolted fault,Arc ?ash incident energy (AFIE),X/R ratio,arc resistant
更新于2025-09-19 17:13:59
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All-optical InAsP/InP nanowire switches integrated in a Si photonic crystal
摘要： We report the successful demonstration of all-optical switching using a sub-wavelength InP/InAsP nanowire integrated in a silicon photonic crystal at telecommunication wavelengths. In this work, we employed two different hybrid nanowire cavities based on an air-trench in photonic crystals. These hybrid cavities have the advantages of both material functionality of III-V material and the low propagation loss of the silicon waveguide. The nanowire induced line-defect photonic crystal cavity shows a Q-factor of 25000, higher than the hybrid systems we previously demonstrated. The switching time is 150 ps, which is among the fastest nanowire switches reported. We found that the switching time was clearly dependent on the Q-factor. From measurements performed while changing pump power, we have estimated the switching energy to be a few hundred femtojoules. This value is lower than that of a reference silicon photonic crystal cavity without a nanowire and an air trench under the same pumping condition. This indicates that the InP/InAsP nanowire integrated in a silicon photonic crystal has potential to contribute to reducing the switching energy.
关键词： all-optical switch,AFM manipulation,nanophotonics,photonic crystal,nanowire,photonic integrated circuits
更新于2025-09-19 17:13:59
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[IEEE 2019 IEEE 7th International Conference on Computer Science and Network Technology (ICCSNT) - Dalian, China (2019.10.19-2019.10.20)] 2019 IEEE 7th International Conference on Computer Science and Network Technology (ICCSNT) - Sub-lens System based on Dispersion Phenomenon of LED Integral Imaging
摘要： A time-delay switch (TDS) attack on a control system is caused by adversaries that strategically imbed time delays into such systems. TDS attacks can make a control system, or more specifically a distributed power control system, unstable. Time delays can be introduced in the sensing loop (SL) or control lines. This paper describes a novel, simple, and effective method to thwart TDS attacks on SL. The proposed method works by augmenting the controller with a time-delay estimator to estimate any time delays. The modified controller controls the system under TDS attack. Also, the time-delay estimator will track time delays introduced by an adversary using a modified model reference control with an indirect supervisor and a modified least mean square minimization technique.
关键词： Time-delay switch attack,model reference control,time-delay estimation
更新于2025-09-19 17:13:59
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[IEEE 2019 IEEE 2nd International Conference on Renewable Energy and Power Engineering (REPE) - Toronto, ON, Canada (2019.11.2-2019.11.4)] 2019 IEEE 2nd International Conference on Renewable Energy and Power Engineering (REPE) - Design and Frequency Control of Small Scale Photovoltaic Hydro Pumped Storage System
摘要： A small-size recon?gurable loop antenna for mobile phone applications with a compact volume of 55 × 5 × 3 mm3 is proposed. In addition to the traditional three loop antenna modes, namely, 0.5-λ, 1-λ, and 1.5-λ modes, the proposed loop antenna also generates another 2-λ mode. To cover more operating bands with such compact antenna volume, the recon?gurable technique is therefore applied by inserting an RF switch at the end of the proposed antenna to improve bandwidth at the low band. By combining the four working states of RF switch, the proposed antenna can cover GSM850/900, DCS1800, PCS1900, UMTS2100, and LTE2300/2500 bands with low speci?c absorption rate and high ef?ciencies.
关键词： loop antenna,RF switch,Mobile phone antenna,recon?gurable antenna
更新于2025-09-19 17:13:59
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[IEEE 2019 Compound Semiconductor Week (CSW) - Nara, Japan (2019.5.19-2019.5.23)] 2019 Compound Semiconductor Week (CSW) - Study on epitaxial lift-off of stacked GaAs solar cells for low-cost photovoltaic application
摘要： This paper presents a new methodology to determine the position of a magnetically guided robot (MGR) in horizontal planes using magnetic ?ux sensors. This position determination methodology can be used independently as well as in collaboration with optical sensors in the case of the optical blockage. A combination of linear Hall-effect sensors (two sensors for each axis of motion) was employed to measure the magnetic ?ux in the MGR’s working space. A con?guration of several electromagnets was used as a source of magnetic ?eld, and an analytical model of the system is developed. The MGR’s position was determined based on the polynomial relation between the Hall-effect sensors’ output and the location of the minimum magnetic potential energy point in horizontal planes. Using the cross-validation method, it was found that a fourth-order polynomial model could accurately predict the MGR’s position. Experiments were conducted on a horizontal plane to validate the performance of position estimation using the magnetic ?ux sensing method. The accuracy of the position determination method was 0.4-mm root-mean-square errors in both the x- and y-direction over 8 × 8 mm2 working area. This paper also experimentally validates a combined optical-magnetic position determination technique for the motion control of a magnetically guided robot in optical blockage conditions as unknown environment that can be used as a promising replacement of X-ray and ultrasound techniques.
关键词： switch control,Dual-axial motion,magnetic ?eld analysis,hall-effect sensor,magnetic levitation
更新于2025-09-19 17:13:59
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[IEEE 2019 International Conference on Recent Advances in Energy-efficient Computing and Communication (ICRAECC) - Nagercoil, India (2019.3.7-2019.3.8)] 2019 International Conference on Recent Advances in Energy-efficient Computing and Communication (ICRAECC) - Free Space Optical Communication and Laser Beam Propagation through Turbulent Atmosphere: A Brief Survey
摘要： A particle ?lter (PF)-based robust navigation with fault diagnosis (FD) is designed for an underwater robot, where 10 failure modes of sensors and thrusters are considered. The nominal underwater robot and its anomaly are described by a switching-mode hidden Markov model. By extensively running a PF on the model, the FD and robust navigation are achieved. Closed-loop full-scale experimental results show that the proposed method is robust, can diagnose faults effectively, and can provide good state estimation even in cases where multiple faults occur. Comparing with other methods, the proposed method can diagnose all faults within a single structure, diagnose simultaneous faults, and it is easily implemented.
关键词： fault tolerance,Fault diagnosis (FD),switch-mode hidden Markov model (HMM),remotely operated underwater vehicle (ROV),particle ?lter (PF),underwater navigation
更新于2025-09-19 17:13:59
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[IEEE 2019 IEEE 21st Electronics Packaging Technology Conference (EPTC) - Singapore, Singapore (2019.12.4-2019.12.6)] 2019 IEEE 21st Electronics Packaging Technology Conference (EPTC) - Fabrication of High Voltage Capable TSV Using Backside via Last Process and Laser Abblation of Dry Film BCB
摘要： Despite rapid advances in the study of brain–computer interfaces (BCIs) in recent decades, two fundamental challenges, namely, improvement of target detection performance and multidimensional control, continue to be major barriers for further development and applications. In this paper, we review the recent progress in multimodal BCIs (also called hybrid BCIs), which may provide potential solutions for addressing these challenges. In particular, improved target detection can be achieved by developing multimodal BCIs that utilize multiple brain patterns, multimodal signals, or multisensory stimuli. Furthermore, multidimensional object control can be accomplished by generating multiple control signals from different brain patterns or signal modalities. Here, we highlight several representative multimodal BCI systems by analyzing their paradigm designs, detection/control methods, and experimental results. To demonstrate their practicality, we report several initial clinical applications of these multimodal BCI systems, including awareness evaluation/detection in patients with disorder of consciousness (DOC). As an evolving research area, the study of multimodal BCIs is increasingly requiring more synergetic efforts from multiple disciplines for the exploration of the underlying brain mechanisms, the design of new effective paradigms and means of neurofeedback, and the expansion of the clinical applications of these systems.
关键词： multimodal brain–computer interface (BCI),awareness evaluation,Audiovisual BCI,brain switch,cursor control
更新于2025-09-19 17:13:59
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Femtosecond Laser-inscribed Non-volatile Integrated Optical Switch in Fused Silica based on Microfluidics-controlled Total Internal Reflection
摘要： We demonstrate a non-volatile optical power switch, fabricated by femtosecond laser inscription in a fused silica substrate, with switching operation based on microfluidics-controlled total internal reflection. The switch consists of crossed waveguides and a rectangular, high aspect ratio microfluidic channel, located at the waveguide crossing. The switching between total internal reflection and transmission at the channel wall is determined by the refractive index of the medium inside the channel. Femtosecond laser inscription allows for co-integration of low-loss optical waveguides and channels with smooth sidewalls and thus the fabrication of low insertion loss switches that are broadband and show low polarization dependent losses. The measured total internal reflection loss of the fabricated switch is about 1.5 dB at the wavelength 1550 nm. The loss due to transmission through the channel filled with refractive index matching liquid is about 0.5 dB. Detailed finite time domain and beam propagation method difference simulations of the switch’s performance indicate that the losses can be further reduced by optimizing its geometry, together with further adjusting the inscription parameters.
关键词： Fused silica,Non-volatile,Single mode waveguides,Total internal reflection,Microfluidics,Femtosecond laser inscription,integrated optical switch
更新于2025-09-19 17:13:59
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[IEEE 2019 Photonics & Electromagnetics Research Symposium - Fall (PIERS - Fall) - Xiamen, China (2019.12.17-2019.12.20)] 2019 Photonics & Electromagnetics Research Symposium - Fall (PIERS - Fall) - Uniformity-modeled Magnetic Resonance Electrical Properties Tomography for Nasopharyngeal Carcinoma
摘要： A new numerical technique to solve nonlinear systems of initial value problems for nonlinear first-order differential equations (ODEs) that model genetic networks in systems biology is developed. This technique is based on finding local Galerkin approximations on each sub-interval at a given time grid of points using piecewise hat functions. Comparing the numerical solution of the new method for a single nonlinear ODE with an exact solution shows that this method gives accurate solutions with relative error 1.88 × 10?11 for a time step 1 × 10?6. This new method is compared with the adaptive Runge Kutta (ARK) method for solving systems of ODEs, and the results are comparable for a time step 2 × 10?4. It is shown that the relative error of the Galerkin method decreases approximately linearly with the log of the number of hat functions used. Unlike the ARK method, this new method has the potential to be parallelizable and to be useful for solving biological problems involving large genetic networks. An NSF commissioned video illustrating how systems biology helps us understand that a fundamental process in cells is included.
关键词： hat function,Galerkin method,systems biology,ordinary differential equation,finite element method,toggle switch,Newton–Raphson method,Biological clock
更新于2025-09-19 17:13:59