299 research outputs found
Detect Any Deepfakes: Segment Anything Meets Face Forgery Detection and Localization
The rapid advancements in computer vision have stimulated remarkable progress
in face forgery techniques, capturing the dedicated attention of researchers
committed to detecting forgeries and precisely localizing manipulated areas.
Nonetheless, with limited fine-grained pixel-wise supervision labels, deepfake
detection models perform unsatisfactorily on precise forgery detection and
localization. To address this challenge, we introduce the well-trained vision
segmentation foundation model, i.e., Segment Anything Model (SAM) in face
forgery detection and localization. Based on SAM, we propose the Detect Any
Deepfakes (DADF) framework with the Multiscale Adapter, which can capture
short- and long-range forgery contexts for efficient fine-tuning. Moreover, to
better identify forged traces and augment the model's sensitivity towards
forgery regions, Reconstruction Guided Attention (RGA) module is proposed. The
proposed framework seamlessly integrates end-to-end forgery localization and
detection optimization. Extensive experiments on three benchmark datasets
demonstrate the superiority of our approach for both forgery detection and
localization. The codes will be released soon at
https://github.com/laiyingxin2/DADF
Combat Network Synchronization of UCAV Formation Based on RTBA Model
The paper aims at developing an efficient method to acquire a proper UCAV formation structure with robust and synchronized features. Here we introduce the RTBA (Route Temporary Blindness Avoidance) model to keep the structure stable and the HPSO (hybrid particle swarm optimization) method is given to find an optimal synchronized formation. The major contributions include the following: (1) setting up the dynamic hierarchy topologic structure of UCAV formation; (2) the RTB phenomenon is described and the RTBA model is put forward; (3) the node choosing rules are used to keep the invulnerability of the formation and the detective information quantifying method is given to measure the effectiveness of the connected nodes; and (4) the hybrid particle swarm optimization method is given to find an optimal synchronized topologic structure. According to the related principles and models, the simulations are given in the end, and the results show that the simplification of the model is available in engineering, and the RTBA model is useful to solve the real problems in combat in some degree
High Energy 2-Micron Solid-State Laser Transmitter for NASA's Airborne CO2 Measurements
A 2-micron pulsed, Integrated Path Differential Absorption (IPDA) lidar instrument for ground and airborne atmospheric CO2 concentration measurements via direct detection method is being developed at NASA Langley Research Center. This instrument will provide an alternate approach to measure atmospheric CO2 concentrations with significant advantages. A high energy pulsed approach provides high-precision measurement capability by having high signal-to-noise level and unambiguously eliminates the contamination from aerosols and clouds that can bias the IPDA measurement
Efficient Tm:Fiber Pumped Solid-State Ho:YLF 2-micrometer Laser for Remote Sensing Applications
An efficient 19 W, TEM(sub 00) mode, Ho:YLF laser pumped by continuous wave Tm:fiber laser has been demonstrated at the room temperature. The slope efficiency and optical-to-optical efficiency are 65% and 55%, respectively
The Sensitive Infrared Signal Detection by Sum Frequency Generation
An up-conversion device that converts 2.05-micron light to 700 nm signal by sum frequency generation using a periodically poled lithium niobate crystal is demonstrated. The achieved 92% up-conversion efficiency paves the path to detect extremely weak 2.05-micron signal with well established silicon avalanche photodiode detector for sensitive lidar applications
A Narrow Linewidth Singly Resonant ZGP OPO for Multiple Lidar Applications
A singly resonant, injection seeded Zinc Germanium Phosphide (ZGP) optical parametric oscillator (OPO), capable to tune over 4.3-10.1 microns, is demonstrated. This ZGP OPO uses a bow-tie cavity with a partially reflective mirror for injection seeding at the signal wavelength. The injection seed source can be either a continuous wave 3.39 m laser or a tunable near-infrared OPO laser, which provides wide wavelength tuning capability. The injection seeded ZGP OPO narrows the idler wavelength linewidth to less than 1nm, limited by the measurement resolution of the monochromator. This device has potential to be used as a transmitter for multiple purpose lidar applications
Development of a Pulsed 2-micron Laser Transmitter for CO2 Sensing from Space
NASA Langley Research Center (LaRC), in collaboration with NASA Jet Propulsion Laboratory (JPL), is engaged in the development and demonstration of a highly efficient, versatile, 2-micron pulsed laser that can be used in a pulsed Differential Absorption Lidar (DIAL)/Integrated Path Differential Absorption (IPDA) instrument to make precise, high-resolution CO2 measurements to investigate sources, sinks, and fluxes of CO2. This laser transmitter will feature performance characteristics needed for an ASCENDS system that will be capable of delivering the CO2 measurement precision required by the Earth Science Decadal Survey (DS)
Infrared Signal Detection by Upconversion Technique
We demonstrated up-conversion assisted detection of a 2.05-micron signal by using a bulk periodically poled Lithium niobate crystal. The 94% intrinsic up-conversion efficiency and 22.58% overall detection efficiency at pW level of 2.05-micron was achieved
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