208 research outputs found
A Survey on Federated Learning in Intelligent Transportation Systems
The development of Intelligent Transportation System (ITS) has brought about
comprehensive urban traffic information that not only provides convenience to
urban residents in their daily lives but also enhances the efficiency of urban
road usage, leading to a more harmonious and sustainable urban life. Typical
scenarios in ITS mainly include traffic flow prediction, traffic target
recognition, and vehicular edge computing. However, most current ITS
applications rely on a centralized training approach where users upload source
data to a cloud server with high computing power for management and centralized
training. This approach has limitations such as poor real-time performance,
data silos, and difficulty in guaranteeing data privacy. To address these
limitations, federated learning (FL) has been proposed as a promising solution.
In this paper, we present a comprehensive review of the application of FL in
ITS, with a particular focus on three key scenarios: traffic flow prediction,
traffic target recognition, and vehicular edge computing. For each scenario, we
provide an in-depth analysis of its key characteristics, current challenges,
and specific manners in which FL is leveraged. Moreover, we discuss the
benefits that FL can offer as a potential solution to the limitations of the
centralized training approach currently used in ITS applications
Direct observation of bulk second-harmonic generation inside a glass slide with tightly focused optical fields
Bulk second-harmonic generation (SHG) inside glass slides is directly detected unambiguously without interference from surface contributions. This is enabled by tightly focused and highly localized ultrashort laser pulses. The theoretical calculations based on vector diffraction theory and the phenomenological model of SHG inside centrosymmetric materials agree well with the measured far-field SHG radiation patterns for different polarization states of the fundamental beam. The results indicate that the observed bulk SHG is predominantly related to the bulk parameter δ′ and originates from the three-dimensional field gradient in the focal region
DREAM: Domain-free Reverse Engineering Attributes of Black-box Model
Deep learning models are usually black boxes when deployed on machine
learning platforms. Prior works have shown that the attributes (, the
number of convolutional layers) of a target black-box neural network can be
exposed through a sequence of queries. There is a crucial limitation: these
works assume the dataset used for training the target model to be known
beforehand and leverage this dataset for model attribute attack. However, it is
difficult to access the training dataset of the target black-box model in
reality. Therefore, whether the attributes of a target black-box model could be
still revealed in this case is doubtful. In this paper, we investigate a new
problem of Domain-agnostic Reverse Engineering the Attributes of a black-box
target Model, called DREAM, without requiring the availability of the target
model's training dataset, and put forward a general and principled framework by
casting this problem as an out of distribution (OOD) generalization problem. In
this way, we can learn a domain-agnostic model to inversely infer the
attributes of a target black-box model with unknown training data. This makes
our method one of the kinds that can gracefully apply to an arbitrary domain
for model attribute reverse engineering with strong generalization ability.
Extensive experimental studies are conducted and the results validate the
superiority of our proposed method over the baselines
2-(2,3-DifluoroÂphenÂyl)ethyl toluene-4-sulfonate
In the title compound, C15H14F2O3S, the dihedral angle between the aromatic rings is 6.19 (13)°. In the crystal, molÂecules are linked by C—H⋯O hydrogen bonds, generating [110] chains
Emission and absorption cross-sections of an Er:GaN waveguide prepared with metal organic chemical vapor deposition
This is the published version. ©Copyright 2011 American Institute of PhysicsWe repost the characterization of emission and absorption cross-sections in an erbium-doped GaN waveguide prepared by metal organic chemical vapor deposition. The emission cross-section was obtained with the Füchtbauer–Ladenburg equation based on the measured spontaneous emission and the radiative carrier lifetime. The absorption cross-section was derived from the emission cross-section through their relation provided from the McCumber’s theory. The conversion efficiency from a 1480 nm pump to 1537 nm emission was measured, which reasonably agreed with the calculation based on the emission and absorption cross-sections
Surface-passivated plasmonic nano-pyramids for bulk heterojunction solar cell photocurrent enhancement
This is the published version. ©Copyright 2012 Royal Society of ChemistryWe report that self-assembled gold (Au) nanopyramid arrays can greatly enhance the photocurrent of narrow bandgap organic solar cells using their plasmonic near-field effect. The plasmonic enhanced power conversion efficiency exhibited up to 200% increase under the AM 1.5 solar illumination
Femtosecond Pulse Temporal Overlap Estimation and Adjustment in SSFS-Based CARS System
This work is licensed under a Creative Commons Attribution 4.0 International License.We present and verify a residual-pump-based temporal overlap estimation method in soliton self-frequency shift-based coherent anti-Stokes Raman scattering system. The residual pump light, output by a highly nonlinear photonic crystal fiber, acts as a crucial link between the pump and Stokes pulses during the temporal overlap estimation. The wavelength-dependent optical delay is estimated to be 0.141 ps/nm when the Stokes wavelength is 900 nm ~1050 nm according to the temporal overlap estimation method. The actual measurement result is 0.138 ps/nm based on the nonresonant signal from a microscope slide, which is very close to the estimated result. In addition, the Raman resonant signals of liquid cyclohexane at 2853 cm -1 , 2923 cm -1 and 2938 cm -1 have also been successfully detected at the predicted optical delays 427.27 ps and 428.17 ps
Cloning and characterization of two subunits of calcineurin cDNA in naked carp (Gymnocypris przewalskii) from Lake Qinghai, China
The naked carp (Gymnocypris przewalskii), a native teleost, plays an important role in maintenance of the ecological balance in the system of Lake Qinghai (altitude, 3.2 km) on the Qinghai-Tibet Plateau in China. Calcineurin (CN) is the only member of the serine/threonine phosphatase family that can be activated by both Ca2+ and calmodulin (CaM) and involved in many important physiological processes such as salt tolerance/adaption. In this report, cDNAs of CN catalytic subunit paralogue isoforms: GpCAα (GenBank accession no.JQ407043), GpCAγ (GenBank accession no. JQ407043), and CN regulatory subunit (GpCB) (GenBank accession no. JQ410473), were isolated from Gymnocypris przewalskii and their expression patterns in embryos developmentwere characterized. Gene expression profile demonstrated that GpCA and GpCB mRNA was distributed ubiquitously in all embryonic stages and showed decline until final stage of development. Immunohistologicalanalysis revealed CN localization in different tissues including kidney, heart, brain, spermary, and gill. Collectively, these results provide molecular basis and clues to further understand the role of CN during embryos development and its function in tissues for the adaptation mechanism of naked carp
Frequency response of cross-phase modulation in multispan WDM optical fiber systems
©1998 IEEE. Personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution to servers or lists, or to reuse any copyrighted component of this work in other works must be obtained from the IEEE.The spectral characteristics of cross-phase modulation (XPM) in multispan intensity-modulation direct-detection optical systems were investigated both experimentally and theoretically. XPM crosstalk levels and its spectral features were found to be strongly dependent on fiber dispersion and optical signal channel spacing. Interference between XPM-induced crosstalk effects created in different amplified fiber spans is also found to be important to determine the overall frequency response of XPM crosstalk effects
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