- 标题
- 摘要
- 关键词
- 实验方案
- 产品
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[IEEE 2019 Compound Semiconductor Week (CSW) - Nara, Japan (2019.5.19-2019.5.23)] 2019 Compound Semiconductor Week (CSW) - Photonic-crystal Lasers with Extremely Short Embedded Active-regions
摘要： Evolutions of Geant4 code have affected the simulation of electron backscattering with respect to previously published results. Their effects are quantified by analyzing the compatibility of the simulated electron backscattering fraction with a large collection of experimental data for a wide set of physics configuration options available in Geant4. Special emphasis is placed on two electron scattering implementations first released in Geant4 version 10.2: the Goudsmit-Saunderson multiple scattering model and a single Coulomb scattering model based on Mott cross section calculation. The new Goudsmit-Saunderson multiple scattering model appears to perform equally or less accurately than the model implemented in previous Geant4 versions, depending on the electron energy. The new Coulomb scattering model was flawed from a physics point of view, but computationally fast in Geant4 version 10.2; the physics correction released in Geant4 version 10.2p01 severely degrades its computational performance. Problems observed in electron backscattering simulation in previous publications have been addressed by evolutions in the Geant4 geometry domain.
关键词： Electrons,Monte Carlo,simulation,Geant4
更新于2025-09-19 17:13:59
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Investigation of 3 dB Optical Intensity Spot Radius of Laser Beam under Scattering Underwater Channel
摘要： An important step in the design of receiver aperture and optimal spacing of the diversity scheme for an underwater laser communication system is to accurately characterize the two-dimensional (2D) spatial distribution of laser beam intensity. In this paper, the 2D optical intensity distribution and 3 dB optical intensity spot radius (OISR) are investigated due to the dominating optical intensity of laser beam being within the 3 dB OISR. By utilizing the Henyey–Greenstein function to compute the scattering angles of photons, the effects of the scattering underwater optical channel and optical system parameters on 3 dB OISR are examined based on the Monte Carlo simulation method. We have shown for the ?rst time that in the channel with a high density of scattering particles, the divergence angle of the laser source plays a negligible role in 3 dB OISR. This is an interesting phenomenon and important for optical communication as this clearly shows that the geometric loss is no longer important for the design of receiver aperture and optimal spacing of the diversity scheme for the underwater laser communication system in the highly scattering channel.
关键词： 3 dB optical intensity spot radius,scattering underwater channel,Monte Carlo simulation method
更新于2025-09-19 17:13:59
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Accurate Sizing of Residential Stand-Alone Photovoltaic Systems Considering System Reliability
摘要： In rural areas or in isolated communities in developing countries it is increasingly common to install micro-renewable sources, such as photovoltaic (PV) systems, by residential consumers without access to the utility distribution network. The reliability of the supply provided by these stand-alone generators is a key issue when designing the PV system. The proper system sizing for a minimum level of reliability avoids unacceptable continuity of supply (undersized system) and unnecessary costs (oversized system). This paper presents a method for the accurate sizing of stand-alone photovoltaic (SAPV) residential generation systems for a pre-established reliability level. The proposed method is based on the application of a sequential random Monte Carlo simulation to the system model. Uncertainties of solar radiation, energy demand, and component failures are simultaneously considered. The results of the case study facilitate the sizing of the main energy elements (solar panels and battery) depending on the required level of reliability, taking into account the uncertainties that affect this type of facility. The analysis carried out demonstrates that deterministic designs of SAPV systems based on average demand and radiation values or the average number of consecutive cloudy days can lead to inadequate levels of continuity of supply.
关键词： photovoltaic generation,battery storage,renewable energy,Monte Carlo Simulation,reliability evaluation
更新于2025-09-19 17:13:59
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Optimal allocation of DSTATCOM considering the uncertainty of photovoltaic systems
摘要： Rational allocation of the distribution static compensator (DSTATCOM) can effectively solve the impact of high penetration of photovoltaic (PV) systems on an active distribution network. Taking the intermittent output of a PV system into consideration, this paper establishes an optimal allocation model of DSTATCOM, in which active power loss, voltage deviation, and total allocation cost are considered as the objective functions. Monte Carlo simulation (MCS) is employed to simulate the random output of PV. Moreover, an opportunity constraint is introduced into the optimal model to evaluate the reliability of the allocation scheme. Multiobjective differential evolution gray wolf optimization (MODEGWO) is proposed to determine the optimal location and capacity of the DSTATCOM. A new optimization method integrating MCS, opportunity constraint, and MODEGWO is proposed to deal with the optimal allocation model of DSTATCOM. The proposed method is validated on an IEEE 33-bus system. Simulation results con?rm the rationality and validity of the proposed model.
关键词： Monte Carlo simulation,opportunity constraint,optimal con?guration,MODEGWO,DSTATCOM
更新于2025-09-19 17:13:59
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[IEEE 2018 International Conference on Intelligent Computing and Communication for Smart World (I2C2SW) - Erode, India (2018.12.14-2018.12.15)] 2018 International Conference on Intelligent Computing and Communication for Smart World (I2C2SW) - An Improved Transformerless Inverter Topology for Grid Connected Photovoltaic System
摘要： In this paper, we report on an optical tolerance analysis of the submillimeter atmospheric multi-beam limb sounder, STEAMR. Physical optics and ray-tracing methods were used to quantify and separate errors in beam pointing and distortion due to re?ector misalignment and primary re?ector surface deformations. Simulations were performed concurrently with the manufacturing of a multi-beam demonstrator of the relay optical system which shapes and images the beams to their corresponding receiver feed horns. Results from Monte Carlo simulations show that the inserts used for re?ector mounting should be positioned with an overall accuracy better than 100 m ( 1/10 wavelength). Analyses of primary re?ector surface deformations show that a deviation of magnitude 100 m can be tolerable before deployment, whereas the corresponding variations should be less than 30 m during operation. The most sensitive optical elements in terms of misalignments are found near the focal plane. This localized sensitivity is attributed to the off-axis nature of the beams at this location. Post-assembly mechanical measurements of the re?ectors in the demonstrator show that alignment better than 50 m could be obtained.
关键词： Stratosphere–Troposphere Exchange And climate Monitor Radiometer (STEAMR),submillimeter-wave instruments,quasi-optics,multi-beam,tolerance analysis,Monte Carlo,Limb viewing
更新于2025-09-19 17:13:59
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[IEEE 2019 IEEE 8th International Conference on Advanced Optoelectronics and Lasers (CAOL) - Sozopol, Bulgaria (2019.9.6-2019.9.8)] 2019 IEEE 8th International Conference on Advanced Optoelectronics and Lasers (CAOL) - Monte Carlo Evaluation of the Uncertainty in a Calibrated Instrument
摘要： A Monte Carlo procedure is presented for computing the joint state-of-knowledge probability distribution to be assigned to the parameters of a calibration function. The procedure is fully in line with the approach in Supplement 1 to the Guide to the Expression of Uncertainty in Measurement. It consists of propagating the joint probability distribution of the calibration quantities through the mathematical model of the measurement by which the parameters are defined. Usually this model is derived from a least-squares adjustment procedure. When the instrument is in use, we desire to obtain the probability distribution for the stimulus that corresponds to an indicated response. This goal can be accomplished by propagating the distributions for the parameters of the calibration curve, together with the distribution of the indicated response.
关键词： calibration functions,probability distributions,curve fitting,Monte Carlo method
更新于2025-09-19 17:13:59
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[IEEE 2020 IEEE Conference of Russian Young Researchers in Electrical and Electronic Engineering (EIConRus) - St. Petersburg and Moscow, Russia (2020.1.27-2020.1.30)] 2020 IEEE Conference of Russian Young Researchers in Electrical and Electronic Engineering (EIConRus) - The Study of Three-dimensional Tissue-engineering Structures Obtained Using Laser Printing for Muscle Regeneration
摘要： Existing optimization methods to heterogeneous redundancy allocation problem often suffer from the local-trap problem in optimization, due to the rugged energy landscapes. In this paper, a new optimization paradigm based on the Markov chain Monte Carlo sampling is proposed for solving the heterogeneous redundancy allocation for multi-state systems. We address this in an optimization-by-sampling framework, and propose to sample the intricate distribution over the combinatorial space by a doubly adaptive sampling approach, where the target adaptation favors free random walk on the rugged energy landscape to substantially alleviate the local-trap problem by updating the target distribution on-the-fly, while the proposal adaptation helps improve the sampling efficiency by learning the proposal distribution based on chain history in optimization. Experimental results performed on a range of benchmark instances demonstrated the superiority of the proposed optimization approach compared with the state-of-the-art alternatives in terms of the solution quality or computational efficiency.
关键词： multi-state system,Optimization-by-sampling,Markov chain Monte Carlo,redundancy allocation problem
更新于2025-09-19 17:13:59
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[IEEE 2019 IEEE 46th Photovoltaic Specialists Conference (PVSC) - Chicago, IL, USA (2019.6.16-2019.6.21)] 2019 IEEE 46th Photovoltaic Specialists Conference (PVSC) - Calculation of the optical losses in perovskite solar cells
摘要： Terminal network reliability problems appear in many real-life applications, such as transportation grids, social and computer networks, communication systems, etc. In this paper, we focus on monotone binary systems with identical component reliabilities. The reliability of such systems depends only on the number of failure sets of all possible sizes, which is an essential system invariant. For large problems, no analytical solution for calculating this invariant in a reasonable time is known to exist, and one has to rely on different approximation techniques. An example of such a method is Permutation Monte Carlo. It is known that this simple plan is not sufficient for adequate estimation of network reliability due to the rare-event problem. As an alternative, we propose a different sampling strategy that is based on the recently pioneered Stochastic Enumeration algorithm for tree cost estimation. We show that, thanks to its built-in splitting mechanism, this method is able to deliver accurate results while employing a relatively modest sample size. Moreover, our numerical results indicate that the proposed sampling scheme is capable of solving problems that are far beyond the reach of the simple Permutation Monte Carlo approach.
关键词： System structure function,splitting,network reliability,rare events,stochastic enumeration,permutation Monte Carlo
更新于2025-09-19 17:13:59
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[IEEE 2019 24th OptoElectronics and Communications Conference (OECC) and 2019 International Conference on Photonics in Switching and Computing (PSC) - Fukuoka, Japan (2019.7.7-2019.7.11)] 2019 24th OptoElectronics and Communications Conference (OECC) and 2019 International Conference on Photonics in Switching and Computing (PSC) - Horizontal Slot Waveguides with Strong Optical Confinement in Low Refractive Index Oxide Films
摘要： In this paper, we report on an optical tolerance analysis of the submillimeter atmospheric multi-beam limb sounder, STEAMR. Physical optics and ray-tracing methods were used to quantify and separate errors in beam pointing and distortion due to re?ector misalignment and primary re?ector surface deformations. Simulations were performed concurrently with the manufacturing of a multi-beam demonstrator of the relay optical system which shapes and images the beams to their corresponding receiver feed horns. Results from Monte Carlo simulations show that the inserts used for re?ector mounting should be positioned with an overall accuracy better than 100 m ( 1/10 wavelength). Analyses of primary re?ector surface deformations show that a deviation of magnitude 100 m can be tolerable before deployment, whereas the corresponding variations should be less than 30 m during operation. The most sensitive optical elements in terms of misalignments are found near the focal plane. This localized sensitivity is attributed to the off-axis nature of the beams at this location. Post-assembly mechanical measurements of the re?ectors in the demonstrator show that alignment better than 50 m could be obtained.
关键词： multi-beam,submillimeter-wave instruments,tolerance analysis,Monte Carlo,Limb viewing,quasi-optics,Stratosphere–Troposphere Exchange And climate Monitor Radiometer (STEAMR)
更新于2025-09-19 17:13:59
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[IEEE 2019 IEEE 46th Photovoltaic Specialists Conference (PVSC) - Chicago, IL, USA (2019.6.16-2019.6.21)] 2019 IEEE 46th Photovoltaic Specialists Conference (PVSC) - High-efficient Cd-free CZTS solar cells achieved by nanoscale atomic layer deposited aluminium oxide
摘要： Existing optimization methods to heterogeneous redundancy allocation problem often suffer from the local-trap problem in optimization, due to the rugged energy landscapes. In this paper, a new optimization paradigm based on the Markov chain Monte Carlo sampling is proposed for solving the heterogeneous redundancy allocation for multi-state systems. We address this in an optimization-by-sampling framework, and propose to sample the intricate distribution over the combinatorial space by a doubly adaptive sampling approach, where the target adaptation favors free random walk on the rugged energy landscape to substantially alleviate the local-trap problem by updating the target distribution on-the-fly, while the proposal adaptation helps improve the sampling efficiency by learning the proposal distribution based on chain history in optimization. Experimental results performed on a range of benchmark instances demonstrated the superiority of the proposed optimization approach compared with the state-of-the-art alternatives in terms of the solution quality or computational efficiency.
关键词： Optimization-by-sampling,Markov chain Monte Carlo,multi-state system,redundancy allocation problem
更新于2025-09-19 17:13:59