- 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) - Radiative and Nonradiative Tunneling in Nanowire Light-Emitting Diodes
摘要： This paper aims to highlight distinctive features of the SP theory of intelligence, realized in the SP computer model, and its apparent advantages compared with some AI-related alternatives. Perhaps most importantly, the theory simplifies and integrates observations and concepts in AI-related areas, and has potential to simplify and integrate of structures and processes in computing systems. Unlike most other AI-related theories, the SP theory is itself a theory of computing, which can be the basis for new architectures for computers. Fundamental in the theory is information compression via the matching and unification of patterns and, more specifically, via a concept of multiple alignment. The theory promotes transparency in the representation and processing of knowledge, and unsupervised learning of natural structures via information compression. It provides an interpretation of aspects of mathematics and an interpretation of phenomena in human perception and cognition. Abstract concepts in the theory may be realized in terms of neurons and their inter-connections (SP-neural). These features and advantages of the SP system are discussed in relation to AI-related alternatives: the concept of minimum length encoding and related concepts, how computational and energy efficiency in computing may be achieved, deep learning in neural networks, unified theories of cognition and related research, universal search, Bayesian networks and some other models for AI, IBM’s Watson, solving problems associated with big data and in the development of intelligence in autonomous robots, pattern recognition and vision, the learning and processing of natural language, exact and inexact forms of reasoning, representation and processing of diverse forms of knowledge, and software engineering. In conclusion, the SP system can provide a firm foundation for the long-term development of AI and related areas, and at the same time, it may deliver useful results on relatively short timescales.
关键词： information compression,unsupervised learning,perception,reasoning,multiple alignment,cognition,deep learning,mathematics,neural networks,Artificial intelligence
更新于2025-09-23 15:19:57
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Reliability of laser-assisted hindfoot alignment evaluation
摘要： [Purpose] A goniometer is frequently used for static measurement of hindfoot alignment. However, although goniometer measurements require experience, their reliability and validity remain controversial. We developed a hindfoot alignment measurement method by laser as an alternative measure. The purpose of this study was to examine the reliability of laser-assisted hindfoot alignment evaluation. [Participants and Methods] Two non-expert examiners (without medical knowledge), briefly trained in the use of laser-assisted hindfoot alignment evaluation, evaluated hindfoot alignment in 12 healthy participants. [Results] The ICC of the intra-rater reliability was 0.74 for both examiners and the ICC for inter-rater reliability was 0.43. [Conclusion] The good intra-rater and moderate inter-rater reliability of laser-assisted hindfoot alignment evaluation, when used by non-professionals, suggest the laser-assisted hindfoot alignment evaluation may be appropriate for use in clinical practice settings.
关键词： Reliability,Laser beam,Hindfoot alignment
更新于2025-09-23 15:19:57
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Efficient Perovskite Solar Cells by Reducing Interfacea??Mediated Recombination: a Bulky Amine Approach
摘要： The presence of non-radiative recombination at the perovskite surface/interface limits the overall efficiency of perovskite solar cells (PSCs). Surface passivation has been demonstrated as an efficient strategy to suppress such recombination in Si cells. Here, 1-naphthylmethylamine iodide (NMAI) is judiciously selected to passivate the surface of the perovskite film. In contrast to the popular phenylethylammonium iodide, NMAI post-treatment primarily leaves NMAI salt on the surface of the perovskite film. The formed NMAI layer not only efficiently decreases the defect-assisted recombination for chemical passivation, but also retards the charge accumulation of energy level mis-alignment for vacuum level bending and prevents minority carrier recombination due to the charge-blocking effect. Consequently, planar PSCs with high efficiency of 21.04% and improved long-term stability (98.9% of the initial efficiency after 3240 h) are obtained. Moreover, open-circuit voltage as high as 1.20 V is achieved at the absorption threshold of 1.61 eV, which is among the highest reported values in planar PSCs. This work provides new insights into the passivation mechanisms of organic ammonium salts and suggests future guidelines for developing improved passivation layers.
关键词： perovskite solar cells,energy level alignment,1-naphthylmethylamine iodide,non-radiative recombination,chemical passivation
更新于2025-09-23 15:19:57
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[IEEE 2019 International Conference on Sustainable Technologies for Industry 4.0 (STI) - Dhaka, Bangladesh (2019.12.24-2019.12.25)] 2019 International Conference on Sustainable Technologies for Industry 4.0 (STI) - A New Medium Voltage Modular Multilevel Inverter with Advanced Carrier-Based Pulse Width Modulation for Solar Photovoltaic Systems
摘要： Millimeter-wave (mmWave) communication operated in frequency bands between 30 and 300 GHz has attracted extensive attention due to the potential ability of offering orders of magnitude greater bandwidths combined with further gains via beamforming and spatial multiplexing from multi-element antenna arrays. mmwave system may exploit the hybrid analog and digital precoding to achieve simultaneously the diversity, array and multiplexing gain with a lower cost of implementation. Motivated by this, in this paper, we investigate the design of hybrid precoder and combiner with sub-connected architecture, where each radio frequency chain is connected to only a subset of base station antennas from the perspective of energy efficient transmission. The problem of interest is a non-convex and NP-hard problem that is difficult to solve directly. In order to address it, we resort to design a two-layer optimization method to solve the problem of interest by exploiting jointly the interference alignment and fractional programming. First, the analog precoder and combiner are optimized via the alternating-direction optimization method where the phase shifter can be easily adjusted with an analytical structure. Then, we optimize the digital precoder and combiner based on an effective multiple-input multiple-output channel coefficient. The convergence of the proposed algorithms is proved using the monotonic boundary theorem and fractional programming theory. Extensive simulation results are given to validate the effectiveness of the presented method and to evaluate the energy efficiency performance under various system configurations.
关键词： analog precoding and combining,interference alignment,energy efficiency,Millimeter-wave communication,multiple-input multiple-output (MIMO) system
更新于2025-09-23 15:19:57
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Properties of Thermally Evaporated Titanium Dioxide as an Electron-Selective Contact for Silicon Solar Cells
摘要： Recently, titanium oxide has been widely investigated as a carrier-selective contact material for silicon solar cells. Herein, titanium oxide ?lms were fabricated via simple deposition methods involving thermal eVaporation and oxidation. This study focuses on characterizing an /TiO2 electron-selective passivated contact layer with this oxidized method. Subsequently, the SiO2 stack was examined using high-resolution transmission electron microscopy. The phase and chemical composition of the titanium oxide ?lms were analyzed using X-ray di?raction and X-ray photoelectron spectroscopy, respectively. The passivation quality of each layer was con?rmed by measuring the carrier lifetime using quasi-steady-state photoconductance, providing an implied open circuit voltage of 644 mV. UV–vis spectroscopy and UV photoelectron spectroscopy analyses demonstrated the band alignment and carrier selectivity of the TiO2 layers. Band o?sets of ~0.33 and ~2.6 eV relative to the conduction and valence bands, respectively, were con?rmed for titanium oxide and the silicon interface.
关键词： carrier-selective contact cell,band alignment,titanium oxide,electron-selective contact
更新于2025-09-23 15:19:57
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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) - Influence of Functional Layers Thickness on CdTe Based Flexible Solar Cells Efficiency
摘要： An intelligent hybrid Taguchi-genetic algorithm (IHTGA) is used to optimize bearing offsets and shaft alignment in a marine vessel propulsion system. The objectives are to minimize normal shaft stress and shear force. The constraints are permissible reaction force, bearing stress, shear force, and bending moment in the shaft thrust ?ange under cold and hot operating conditions. Accurate alignment of the shaft for a main propulsion system is important for ensuring the safe operation of a vessel. To obtain a set of acceptable forces and stresses for the bearings and shaft under operating conditions, the optimal bearing offsets must be determined. Instead of the time-consuming classical local search methods with some trial-and-error procedures used in most shipyards to optimize bearing offsets, this paper used IHTGA. The proposed IHTGA performs Taguchi method between the crossover operation of the conventional GA. Incorporating the systematic reasoning ability of Taguchi method in the crossover operation enables intelligent selection of genes used to achieve crossover, which enhances the performance of the IHTGA in terms of robustness, statistical performance, and convergence speed. A penalty function method is performed using the ?tness function as a pseudo-objective function comprising a linear combination of design objectives and constraints. A ?nite-element method is also used to determine the reaction forces and stresses in the bearings and to determine normal stresses, bending moments, and shear forces in the shaft. Computational experiments in a 2200 TEU container vessel show that the results obtained by the proposed IHTGA are signi?cantly better than those obtained by the conventional local search methods with some trial-and-error procedures.
关键词： genetic algorithm,shaft alignment,Marine vessel propulsion system,bearing offsets,optimal design
更新于2025-09-23 15:19:57
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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) - The Response Characteristics of Dielectric Logging in Anisotropic Formation
摘要： Millimeter-wave (mmWave) communication operated in frequency bands between 30 and 300 GHz has attracted extensive attention due to the potential ability of offering orders of magnitude greater bandwidths combined with further gains via beamforming and spatial multiplexing from multi-element antenna arrays. mmwave system may exploit the hybrid analog and digital precoding to achieve simultaneously the diversity, array and multiplexing gain with a lower cost of implementation. Motivated by this, in this paper, we investigate the design of hybrid precoder and combiner with sub-connected architecture, where each radio frequency chain is connected to only a subset of base station antennas from the perspective of energy efficient transmission. The problem of interest is a non-convex and NP-hard problem that is difficult to solve directly. In order to address it, we resort to design a two-layer optimization method to solve the problem of interest by exploiting jointly the interference alignment and fractional programming. First, the analog precoder and combiner are optimized via the alternating-direction optimization method where the phase shifter can be easily adjusted with an analytical structure. Then, we optimize the digital precoder and combiner based on an effective multiple-input multiple-output channel coefficient. The convergence of the proposed algorithms is proved using the monotonic boundary theorem and fractional programming theory. Extensive simulation results are given to validate the effectiveness of the presented method and to evaluate the energy efficiency performance under various system configurations.
关键词： Millimeter-wave communication,energy efficiency,interference alignment,analog precoding and combining,multiple-input multiple-output (MIMO) system
更新于2025-09-23 15:19:57
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A Comparative Study on the Photovoltaic Properties of ZnX (X=S, Se, Te) QD/CNT Inorganic/Organic Hybrid Nanocomposites
摘要： Designing the efficient inorganic/organic hybrid light harvesting systems through understanding of charge generation, separation and recombination dynamics is an important pathway for improvement of power conversion efficiency (PCE) of photovoltaic cell. Using density functional method, we explored the photovoltaic performance of recently synthesized ZnX (X=S, Se, Te) QD/carbon nanotube (CNT) nanocomposites. Interestingly, ZnX QD/CNT nanocomposites exhibit type-II band alignment, where hole and electron charge carriers are localized on ZnX QD and CNT, respectively. However, the energy difference between highest occupied molecular orbital of ZnXQD and conduction band minimum of CNT is very small (0.09-0.26 eV), implying huge possibilities of electron-hole recombination at ZnX:CNT interface. To overcome such unpleasant situation, we focus on chemical modification of CNT. The CNT is hydrogenated by attachment of atomic hydrogen and next the hydrogenated CNT is functionalized by electron withdrawing group (-CN) in part. We found that ZnX QD and CN functionalized hydrogenated CNT nanocomposites exhibit intended type-II band alignment and achieve high PCEs in the range of 6.73-8.38%, making them exceptionally competitive with other previously reported hybrid solar cells.
关键词： inorganic/organic hybrid nanocomposites,power conversion efficiency,ZnX QD/CNT,type-II band alignment,photovoltaic properties
更新于2025-09-23 15:19:57
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Rate Equation Modeling of Interband Cascade Lasers on Modulation and Noise Dynamics
摘要： An intelligent hybrid Taguchi-genetic algorithm (IHTGA) is used to optimize bearing offsets and shaft alignment in a marine vessel propulsion system. The objectives are to minimize normal shaft stress and shear force. The constraints are permissible reaction force, bearing stress, shear force, and bending moment in the shaft thrust ?ange under cold and hot operating conditions. Accurate alignment of the shaft for a main propulsion system is important for ensuring the safe operation of a vessel. To obtain a set of acceptable forces and stresses for the bearings and shaft under operating conditions, the optimal bearing offsets must be determined. Instead of the time-consuming classical local search methods with some trial-and-error procedures used in most shipyards to optimize bearing offsets, this paper used IHTGA. The proposed IHTGA performs Taguchi method between the crossover operation of the conventional GA. Incorporating the systematic reasoning ability of Taguchi method in the crossover operation enables intelligent selection of genes used to achieve crossover, which enhances the performance of the IHTGA in terms of robustness, statistical performance, and convergence speed. A penalty function method is performed using the ?tness function as a pseudo-objective function comprising a linear combination of design objectives and constraints. A ?nite-element method is also used to determine the reaction forces and stresses in the bearings and to determine normal stresses, bending moments, and shear forces in the shaft. Computational experiments in a 2200 TEU container vessel show that the results obtained by the proposed IHTGA are signi?cantly better than those obtained by the conventional local search methods with some trial-and-error procedures.
关键词： bearing offsets,optimal design,Marine vessel propulsion system,shaft alignment,genetic algorithm
更新于2025-09-23 15:19:57
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[SPIE Optical System Alignment, Tolerancing, and Verification XII - San Diego, United States (2018.8.19-2018.8.23)] Optical System Alignment, Tolerancing, and Verification XII - Introduction to optical alignment techniques: a long-running SPIE short course
摘要： The SPIE short course “Introduction to Optical Alignment Techniques” has been taught for over twenty years at many SPIE conferences. It has always been one of the well attended ones, indicating a need for the subject matter. Reviews of first order concepts, and the basic optical aberrations set the stage for understanding how optical systems become misaligned, how to recognize the aberration type and diagnose what is wrong. This will suggest solutions to the alignment problem, enabling failing optical assemblies to be corrected. The course closes with a discussion of the alignment issues that impact off-axis parabolas and higher-order aspheres.
关键词： off-axis aspheres,alignment telescopes,Optical alignment
更新于2025-09-19 17:15:36