The method of describing deformation camouflage spots based on feature space has some shortcomings,such as inaccurate description and difficult reproduction.Depending on the strong fitting ability of the generative ad...The method of describing deformation camouflage spots based on feature space has some shortcomings,such as inaccurate description and difficult reproduction.Depending on the strong fitting ability of the generative adversarial network model,the distribution of deformation camouflage spot pattern can be directly fitted,thus simplifying the process of spot extraction and reproduction.The requirements of background spot extraction are analyzed theoretically.The calculation formula of limiting the range of image spot pixels is given and two kinds of spot data sets,forestland and snowfield,are established.Spot feature is decomposed into shape,size and color features,and a GAN(Generative Adversarial Network)framework is established.The effects of different loss functions on network training results are analyzed in the experiment.In the meantime,when the input dimension of generator network is 128,the balance between sample diversity and quality can be achieved.The effects of sample generation are investigated in two aspects.Subjectively,the probability of the generated spots being distinguished in the background is counted,and the results are all less than 20% and mostly close to zero.Objectively,the features of the spot shape are calculated and the independent sample T-test is applied to verify that the features are from the same distribution,and all the P-Values are much higher than 0.05.Both subjective and objective methods prove that the spots generated by this method are similar to the background spots.The proposed method can directly generate the desired camouflage pattern spots,which provides a new technical method for the deformation camouflage pattern design and camouflage effect evaluation.展开更多
Brain functional networks model the brain's ability to exchange information across different regions,aiding in the understanding of the cognitive process of human visual attention during target searching,thereby c...Brain functional networks model the brain's ability to exchange information across different regions,aiding in the understanding of the cognitive process of human visual attention during target searching,thereby contributing to the advancement of camouflage evaluation.In this study,images with various camouflage effects were presented to observers to generate electroencephalography(EEG)signals,which were then used to construct a brain functional network.The topological parameters of the network were subsequently extracted and input into a machine learning model for training.The results indicate that most of the classifiers achieved accuracy rates exceeding 70%.Specifically,the Logistic algorithm achieved an accuracy of 81.67%.Therefore,it is possible to predict target camouflage effectiveness with high accuracy without the need to calculate discovery probability.The proposed method fully considers the aspects of human visual and cognitive processes,overcomes the subjectivity of human interpretation,and achieves stable and reliable accuracy.展开更多
The combination of advanced photoelectric detectors has rendered single-band camouflage materials ineffective,necessitating the development of infrared multispectral camouflage.However,the design and fabrication of ex...The combination of advanced photoelectric detectors has rendered single-band camouflage materials ineffective,necessitating the development of infrared multispectral camouflage.However,the design and fabrication of existing works remain complex as they usually require the integration of multiscale structures.Here,we introduce phase modulation into the infrared camouflage metasurfaces with metal-dielectric-metal configuration,enabling them to achieve camouflage across more bands.Based on this strategy,a simple but effective single-layer cascaded metasurface is demonstrated for the first time to achieve low reflection at multi-wavelength lasers,low infrared radiation in atmospheric windows,and broadband thermal management.As a proof-of-concept,a 4-inch sample with a minimum linewidth of 1.8μm is fabricated using photolithography.The excellent infrared multispectral camouflage performance is verified in experiments,showing low reflectance in 0.9–1.6μm,low infrared emissivity in mid-wavelength infrared(MWIR)and long-wavelength infrared(LWIR)bands,and high absorptance at the wavelength of 10.6μm.Meanwhile,broadband high emissivity in 5–8μm can provide high-performance radiative heat dissipation.When the input power is 1.57 W·cm^(-2),the surface/radiation temperature of the metasurface decreases by 5.3℃/18.7℃ compared to the reference.The proposed metasurface may trigger further innovation in the design and application of compact multispectral optical devices.展开更多
Combining deep-learning image inpainting algorithms with the microfluidic technology,the paper proposes a method to achieve dynamic stealth and camouflage by using a microfluidic vision camouflage system simulating th...Combining deep-learning image inpainting algorithms with the microfluidic technology,the paper proposes a method to achieve dynamic stealth and camouflage by using a microfluidic vision camouflage system simulating the chameleon skin.The basic principle is to perceive color changes in the external environment and collect ambient image information,and then utilize the image inpainting algorithm to adjust the control signals of the microfluidic system in real time.The detailed working principle of the microfluidic vision camouflage system is presented,and the mechanism of generating control signals for the system through deep-learning image inpainting algorithms and image-processing techniques is elucidated.The camouflage effect of the chameleon skin is analyzed and evaluated using color similarity.Results indicate that the camouflaged images are consistent with the background environment,thereby improving the target’s stealth and maneuvering characteristics.The camouflage technology developed in the paper based on the microfluidic vision camouflage system can be applied to several situations,such as military camouflage uniforms,robot skins,and weapon equipment.展开更多
Most multispectral compatible infrared camouflage devices primarily focus on achieving low emissivity but neglect environmental emissivity matching when environmental emissivity exceeds that of the devices,this create...Most multispectral compatible infrared camouflage devices primarily focus on achieving low emissivity but neglect environmental emissivity matching when environmental emissivity exceeds that of the devices,this creates a"low-emissivity exposure"risk.To address this issue,we develop a tunable multispectral compatible infrared camouflage device using phase change material In3SbTe2(IST).Simulation and experimental results demonstrate that in both the amorphous(aIST)and crystalline(cIST)states,the device achieves simulated plant infrared camouflage and ultra-low emissivity infrared camouflage within the atmospheric window bands(3–5μm and 8–14μm).To address thermal management,it utilizes two non-atmospheric window bands(2.5–3μm and 5–8μm)for heat dissipation.Additionally,laser stealth is realized at three specific wavelengths(1.064μm,1.55μm,and 10.6μm).In the visible spectrum,high absorptivity enables effective visible light camouflage.Adjusting the geometric parameters of top layer structure enables color variation.This work not only highlights potential applications in reversible switching,reconfigurable imaging,and dynamic coding using IST but also offers an effective strategy to counter multispectral detection technology.展开更多
This study serves as a guide to the development of a polydimethylsiloxane(PDMS)-encapsulated liquid metal-MXene aerogel,which has proven to be highly effective for electromagnetic wave absorption,particularly in salin...This study serves as a guide to the development of a polydimethylsiloxane(PDMS)-encapsulated liquid metal-MXene aerogel,which has proven to be highly effective for electromagnetic wave absorption,particularly in saline environments.Through directional freezing and casting techniques,we have optimized the sample to exhibit enhanced absorption properties,achieving a reflection loss peak of-63.10 dB at 14.36 GHz.Variations in liquid metal content were found to significantly impact the complex permittivity of the aerogel,resulting in decreases observed in both real and imaginary components.This underscores the crucial role of conductivity in electromagnetic wave damping.Simultaneously,increases in tangent loss and attenuation constant highlight the vital contribution of MXene towards dissipating electromagnetic energy.Our best sample exhibits enhanced mechanical robustness,as evidenced by a high tensile modulus of 1 MPa.Notably,this exceptional performance is sustained for an extended period of 4 weeks even under harsh conditions such as high temperature,acid mist exposure,alkaline exposure,and immersion in synthetic seawater.By testing the thermal camouflage performance,samples achieved processable and efficient camouflage performance at multiple temperatures.This comprehensive dataset confirms the adaptability of the PDMS-encapsulated liquid metal-MXene aerogel as an effective solution for electromagnetic wave absorption in challenging environmental scenarios.展开更多
Deep neural networks,especially face recognition models,have been shown to be vulnerable to adversarial examples.However,existing attack methods for face recognition systems either cannot attack black-box models,are n...Deep neural networks,especially face recognition models,have been shown to be vulnerable to adversarial examples.However,existing attack methods for face recognition systems either cannot attack black-box models,are not universal,have cumbersome deployment processes,or lack camouflage and are easily detected by the human eye.In this paper,we propose an adversarial pattern generation method for face recognition and achieve universal black-box attacks by pasting the pattern on the frame of goggles.To achieve visual camouflage,we use a generative adversarial network(GAN).The scale of the generative network of GAN is increased to balance the performance conflict between concealment and adversarial behavior,the perceptual loss function based on VGG19 is used to constrain the color style and enhance GAN’s learning ability,and the fine-grained meta-learning adversarial attack strategy is used to carry out black-box attacks.Sufficient visualization results demonstrate that compared with existing methods,the proposed method can generate samples with camouflage and adversarial characteristics.Meanwhile,extensive quantitative experiments show that the generated samples have a high attack success rate against black-box models.展开更多
Although multifunctional electromagnetic interference(EMI)shielding materials with ultrahigh electromagnetic wave absorption are highly required to solve increasingly serious electromagnetic radiation and pollution an...Although multifunctional electromagnetic interference(EMI)shielding materials with ultrahigh electromagnetic wave absorption are highly required to solve increasingly serious electromagnetic radiation and pollution and meet multi-scenario applications,EMI shielding materials usually cause a lot of reflection and have a single function.To realize the broadband absorption-dominated EMI shielding via absorption-reflection-reabsorption mechanisms and the interference cancelation effect,multifunctional asymmetric bilayer aerogels are designed by sequential printing of a MXene-graphene oxide(MG)layer with a MG emulsion ink and a conductive MXene layer with a MXene ink and subsequent freeze-drying for generating and solidifying numerous pores in the aerogels.The top MG layer of the asymmetric bilayer aerogel optimizes impedance matching and achieves re-absorption,while the bottom MXene layer enhances the reflection of the incident electromagnetic waves.As a result,the asymmetric bilayer aerogel achieves an average absorption coefficient of 0.95 in the X-band and shows the tunable absorption ability to electromagnetic wave in the ultrawide band from 8.2 to 40 GHz.Finite element simulations substantiate the effectiveness of the asymmetric bilayer aerogel for electromagnetic wave absorption.The multifunctional bilayer aerogels exhibit hydrophobicity,thermal insulation and Joule heating capacities and are efficient in solar-thermal/electric heating,infrared stealth,and clean-up of spilled oil.展开更多
Accurate segmentation of camouflage objects in aerial imagery is vital for improving the efficiency of UAV-based reconnaissance and rescue missions.However,camouflage object segmentation is increasingly challenging du...Accurate segmentation of camouflage objects in aerial imagery is vital for improving the efficiency of UAV-based reconnaissance and rescue missions.However,camouflage object segmentation is increasingly challenging due to advances in both camouflage materials and biological mimicry.Although multispectral-RGB based technology shows promise,conventional dual-aperture multispectral-RGB imaging systems are constrained by imprecise and time-consuming registration and fusion across different modalities,limiting their performance.Here,we propose the Reconstructed Multispectral-RGB Fusion Network(RMRF-Net),which reconstructs RGB images into multispectral ones,enabling efficient multimodal segmentation using only an RGB camera.Specifically,RMRF-Net employs a divergentsimilarity feature correction strategy to minimize reconstruction errors and includes an efficient boundary-aware decoder to enhance object contours.Notably,we establish the first real-world aerial multispectral-RGB semantic segmentation of camouflage objects dataset,including 11 object categories.Experimental results demonstrate that RMRF-Net outperforms existing methods,achieving 17.38 FPS on the NVIDIA Jetson AGX Orin,with only a 0.96%drop in mIoU compared to the RTX 3090,showing its practical applicability in multimodal remote sensing.展开更多
Video camouflaged object detection(VCOD)has become a fundamental task in computer vision that has attracted significant attention in recent years.Unlike image camouflaged object detection(ICOD),VCOD not only requires ...Video camouflaged object detection(VCOD)has become a fundamental task in computer vision that has attracted significant attention in recent years.Unlike image camouflaged object detection(ICOD),VCOD not only requires spatial cues but also needs motion cues.Thus,effectively utilizing spatiotemporal information is crucial for generating accurate segmentation results.Current VCOD methods,which typically focus on exploring motion representation,often ineffectively integrate spatial and motion features,leading to poor performance in diverse scenarios.To address these issues,we design a novel spatiotemporal network with an encoder-decoder structure.During the encoding stage,an adjacent space-time memory module(ASTM)is employed to extract high-level temporal features(i.e.,motion cues)from the current frame and its adjacent frames.In the decoding stage,a selective space-time aggregation module is introduced to efficiently integrate spatial and temporal features.Additionally,a multi-feature fusion module is developed to progressively refine the rough prediction by utilizing the information provided by multiple types of features.Furthermore,we incorporate multi-task learning into the proposed network to obtain more accurate predictions.Experimental results show that the proposed method outperforms existing cutting-edge baselines on VCOD benchmarks.展开更多
Due to Visible light and Near-Infrared(Vis–NIR)stealth play an important role in the commercial,military,and scientific fields,camouflage materials related to it attracted increasing attention in decades.Green plant ...Due to Visible light and Near-Infrared(Vis–NIR)stealth play an important role in the commercial,military,and scientific fields,camouflage materials related to it attracted increasing attention in decades.Green plant leaves,as the most extensive background materials on the earth,were widely simulated in the camouflage materials.However,difficult full-spectrum simulation(380–2500 nm),low-similarity simulation and the complex preparation have been great challenges for Vis–NIR Camouflage Materials(Vis–NIR-CMs).Herein,basing on the color-matching principle,two novel Vis–NIR-CMs including Dark Green Materials and Light Green Materials(DGM and LGM)were facilely fabricated by simple printing organic disperse dyes including C.I.Disperse Blue 291,C.I.Disperse Yellow 114,and C.I.Disperse Orange 30(B-291,Y-114 and O-30),and titanium dioxide(TiO_(2))on the viscose fabrics.Based on the excellent red edge property of B-291 and high scattering ability of TiO2,DGM and LGM exhibited generally high spectral correlation coefficients r_(m)(>0.95)with green plant leaves.Moreover,with the great color performance,excellent objects covering performance,low areal density(<146.3 g cm^(−2)),high tensile strength(>7.7 MPa),high softness(>81.27),high air permeability(>45.848 mm s^(−1)),DGM and LGM showed good simulation performance and wearing comfort to satisfy the application needs.This work presents a high-similarity Vis–NIR-CMs as a reference for full-spectrum camouflage materials,as well as low-cost and efficient preparation method is beneficial to the development of camouflage field.展开更多
The object detectors can precisely detect the camouflaged object beyond human perception.The investigations reveal that the CNNs-based(Convolution Neural Networks)detectors are vulnerable to adversarial attacks.Some w...The object detectors can precisely detect the camouflaged object beyond human perception.The investigations reveal that the CNNs-based(Convolution Neural Networks)detectors are vulnerable to adversarial attacks.Some works can fool detectors by crafting the adversarial camouflage attached to the object,leading to wrong prediction.It is hard for military operations to utilize the existing adversarial camouflage due to its conspicuous appearance.Motivated by this,this paper proposes the Dual Attribute Adversarial Camouflage(DAAC)for evading the detection by both detectors and humans.Generating DAAC includes two steps:(1)Extracting features from a specific type of scene to generate individual soldier digital camouflage;(2)Attaching the adversarial patch with scene features constraint to the individual soldier digital camouflage to generate the adversarial attribute of DAAC.The visual effects of the individual soldier digital camouflage and the adversarial patch will be improved after integrating with the scene features.Experiment results show that objects camouflaged by DAAC are well integrated with background and achieve visual concealment while remaining effective in fooling object detectors,thus evading the detections by both detectors and humans in the digital domain.This work can serve as the reference for crafting the adversarial camouflage in the physical world.展开更多
Semiconducting conjugated polymer nanoparticles(SPNs)represent an emerging class of phototheranostic materi-als with great promise for cancer treatment.In this report,low-bandgap electron donoracceptor(DA)-conjugated ...Semiconducting conjugated polymer nanoparticles(SPNs)represent an emerging class of phototheranostic materi-als with great promise for cancer treatment.In this report,low-bandgap electron donoracceptor(DA)-conjugated SPNs with sur-face cloaked by red blood cell membrane(RBCM)are developed for highly e ective photoacoustic imaging and photothermal therapy.The resulting RBCM-coated SPN(SPN@RBCM)displays remarkable near-infrared light absorption and good photosta-bility,as well as high photothermal conver-sion e ciency for photoacoustic imaging and photothermal therapy.Particularly,due to the small size(<5 nm),SPN@RBCM has the advantages of deep tumor penetration and rapid clearance from the body with no appreciable toxicity.The RBCM endows the SPNs with prolonged systematic circulation time,less reticuloendothelial system uptake and reduced immune-recognition,hence improving tumor accumulation after intravenous injection,which provides strong photoacoustic signals and exerts excellent photothermal therapeutic e ects.Thus,this work provides a valuable paradigm for safe and highly e cient tumor pho-toacoustic imaging and photothermal therapy for further clinical translation.展开更多
There are two major camouflage protections in modern military tactics:UV-protection and near infrared camouflage.However,not all natural and composite dyestuffs provide the mentioned properties.In this study,the cotto...There are two major camouflage protections in modern military tactics:UV-protection and near infrared camouflage.However,not all natural and composite dyestuffs provide the mentioned properties.In this study,the cotton fabric was dyed with natural indigo and the natural indigo dyeing process was optimized.Green leaves were chosen as the simulating object,and the camouflage properties of the dyed cotton fabric were evaluated.It was observed that the dyed cotton fabric had good UV-protection and near-infrared camouflage properties.The UV-protection effect was strongly dependent on the absorption characteristics of natural indigo for UV radiation.The near infrared camouflage effect was mainly dependent on the reflection spectrum characteristics of natural indigo in the near infrared waveband.展开更多
The evaluation index of camouflage patterns is important in the field of military application.It is the goal that researchers have always pursued to make the computable evaluation indicators more in line with the huma...The evaluation index of camouflage patterns is important in the field of military application.It is the goal that researchers have always pursued to make the computable evaluation indicators more in line with the human visual mechanism.In order to make the evaluation method more computationally intelligent,a Multi-Feature Camouflage Fused Index(MF-CFI)is proposed based on the comparison of grayscale,color and texture features between the target and the background.In order to verify the effectiveness of the proposed index,eye movement experiments are conducted to compare the proposed index with existing indexes including Universal Image Quality Index(UIQI),Camouflage Similarity Index(CSI)and Structural Similarity(SSIM).Twenty-four different simulated targets are designed in a grassland background,28 observers participate in the experiment and record the eye movement data during the observation process.The results show that the highest Pearson correlation coefficient is observed between MF-CFI and the eye movement data,both in the designed digital camouflage patterns and largespot camouflage patterns.Since MF-CFI is more in line with the detection law of camouflage targets in human visual perception,the proposed index can be used for the comparison and parameter optimization of camouflage design algorithms.展开更多
Multifunctional,flexible,and robust thin films capable of operating in demanding harsh temperature environments are crucial for various cutting-edge applications.This study presents a multifunctional Janus film integr...Multifunctional,flexible,and robust thin films capable of operating in demanding harsh temperature environments are crucial for various cutting-edge applications.This study presents a multifunctional Janus film integrating highly-crystalline Ti_(3)C_(2)T_(x) MXene and mechanically-robust carbon nanotube(CNT)film through strong hydrogen bonding.The hybrid film not only exhibits high electrical conductivity(4250 S cm^(-1)),but also demonstrates robust mechanical strength and durability in both extremely low and high temperature environments,showing exceptional resistance to thermal shock.This hybrid Janus film of 15μm thickness reveals remarkable multifunctionality,including efficient electromagnetic shielding effectiveness of 72 dB in X band frequency range,excellent infrared(IR)shielding capability with an average emissivity of 0.09(a minimal value of 0.02),superior thermal camouflage performance over a wide temperature range(−1 to 300℃)achieving a notable reduction in the radiated temperature by 243℃ against a background temperature of 300℃,and outstanding IR detection capability characterized by a 44%increase in resistance when exposed to 250 W IR radiation.This multifunctional MXene/CNT Janus film offers a feasible solution for electromagnetic shielding and IR shielding/detection under challenging conditions.展开更多
Camouflage is ubiquitous in the natural world and benefits both predators and prey. Amongst the range of conceal- ment strategies, disruptive coloration is thought to visually fragment an animal＇s＇ outline, thereby ...Camouflage is ubiquitous in the natural world and benefits both predators and prey. Amongst the range of conceal- ment strategies, disruptive coloration is thought to visually fragment an animal＇s＇ outline, thereby reducing its rate of discovery. Here, I propose two non-mutually exclusive hypotheses for how disruptive camouflage functions, and describe the visual me- chanisms that might underlie them. （1） The local edge disruption hypothesis states that camouflage is achieved by breaking up edge information. （2） The global feature disruption hypothesis states camouflage is achieved by breaking up the characteristic features of an animal （e.g., overall shape or facial features）. Research clearly shows that putatively disruptive edge markings do increase concealment; however, few tests have been undertaken to determine whether this survival advantage is attributable to the distortion of features, so the global feature disruption hypothesis is under studied. In this review the evidence for global feature disruption is evaluated. Further, I address if object recognition processing provides a feasible mechanism for animals＇ features to influence concealment. This review concludes that additional studies are needed to test if disruptive camouflage operates through the global feature disruption and proposes future research directions [Current Zoology 61 （4）： 708-717, 2015].展开更多
Camouflage is one of the most widespread and powerful strategies that animals use to make detection/recognition more difficult. Many orb-web spiders of the genus Cyclosa add prey remains, plant debris, moults, and/or ...Camouflage is one of the most widespread and powerful strategies that animals use to make detection/recognition more difficult. Many orb-web spiders of the genus Cyclosa add prey remains, plant debris, moults, and/or eggsacs to their webs called web decorations. Web decorations resembling spider body colour pattern have been considered to camouflage the spider from predators. While this camouflage is obvious from a human＇s perspective, it has rarely been investigated from a predator＇s perspective. In this study, we tested the visibility of web decorations by calculating chromatic and achromatic contrasts of detritus and eggsae decorations built by Cyclosa octotubereulata, against four different backgrounds viewed by both bird （e.g., blue tits） and hymenopteran （e.g. wasps） predators. We showed that both juvenile and adult spiders on webs with detritus or egg-sac deco- rations were undetectable by both hymenopteran and bird predators over short and long distances. Our results thus suggest that decorating webs with detritus or eggsacs by C octotuberculata may camouflage the spiders from both hymenopteran and bird predators in their common habitats [Current Zoology 56 （3）： 379-387, 2010].展开更多
The round-tailed homed lizard Phrynosoma modestum is cryptically colored and resembles a small stone when it draws legs close to its body and elevates its back. We investigated effectiveness of camouflage in P. modest...The round-tailed homed lizard Phrynosoma modestum is cryptically colored and resembles a small stone when it draws legs close to its body and elevates its back. We investigated effectiveness of camouflage in P. modestum and its dependence on stones by placing a lizard in one of two microhabitats （uniform sand or sand with surface rocks approximately the same size as lizards）. An observer who knew which microhabitat contained the lizard was asked to locate the lizard visually. Latency to detec- tion was longer and probability of no detection within 60 s was higher for lizards on rock background than on bare sand. In arenas where lizards could choose to occupy rock or bare sand, much higher proportions selected rocky backgrounds throughout the day; at night all lizards slept among stones. A unique posture gives P modestum a rounded appearance similar to many natural stones. Lizards occasionally adopted the posture, but none did so in response to a nearby experimenter. Stimuli that elicit the posture are unknown. That P. modestum is better camouflaged among rocks than on bare sand and prefers to occupy rocky areas suggests that special resemblance to rocks （masquerade） enhances camouflage attributable to coloration and immobility.展开更多
To adapt to a complex and variable environment,self-adaptive camouflage technology is becoming more and more important in all kinds of military applications by overcoming the weakness of the static camouflage.In natur...To adapt to a complex and variable environment,self-adaptive camouflage technology is becoming more and more important in all kinds of military applications by overcoming the weakness of the static camouflage.In nature,the chameleon can achieve self-adaptive camouflage by changing its skin color in real time with the change of the background color.To imitate the chameleon skin,a camouflaged film controlled by a color-changing microfluidic system is proposed in this paper.The film with microfluidic channels fabricated by soft materials can achieve dynamic cloaking and camouflage by circulating color liquids through channels inside the film.By sensing and collecting environmental color change information,the control signal of the microfluidic system can be adjusted in real time to imitate chameleon skin.The microstructure of the film and the working principle of the microfluidic color-changing system are introduced.The mechanism to generate the control signal by information processing of background colors is illustrated.“Canny”double-threshold edge detection algorithm and color similarity are used to analyze and evaluate the camouflage.The tested results show that camouflaged images have a relatively high compatibility with environmental backgrounds and the dynamic cloaking eff ect can be achieved.展开更多
基金This research was funded by Natural Science Foundation of Jiangsu Province,grant number BK20180579.
文摘The method of describing deformation camouflage spots based on feature space has some shortcomings,such as inaccurate description and difficult reproduction.Depending on the strong fitting ability of the generative adversarial network model,the distribution of deformation camouflage spot pattern can be directly fitted,thus simplifying the process of spot extraction and reproduction.The requirements of background spot extraction are analyzed theoretically.The calculation formula of limiting the range of image spot pixels is given and two kinds of spot data sets,forestland and snowfield,are established.Spot feature is decomposed into shape,size and color features,and a GAN(Generative Adversarial Network)framework is established.The effects of different loss functions on network training results are analyzed in the experiment.In the meantime,when the input dimension of generator network is 128,the balance between sample diversity and quality can be achieved.The effects of sample generation are investigated in two aspects.Subjectively,the probability of the generated spots being distinguished in the background is counted,and the results are all less than 20% and mostly close to zero.Objectively,the features of the spot shape are calculated and the independent sample T-test is applied to verify that the features are from the same distribution,and all the P-Values are much higher than 0.05.Both subjective and objective methods prove that the spots generated by this method are similar to the background spots.The proposed method can directly generate the desired camouflage pattern spots,which provides a new technical method for the deformation camouflage pattern design and camouflage effect evaluation.
基金sponsored by the National Defense Science and Technology Key Laboratory Fund(Grant No.61422062205)the Equipment Pre-Research Fund(Grant No.JCKYS2022LD9)。
文摘Brain functional networks model the brain's ability to exchange information across different regions,aiding in the understanding of the cognitive process of human visual attention during target searching,thereby contributing to the advancement of camouflage evaluation.In this study,images with various camouflage effects were presented to observers to generate electroencephalography(EEG)signals,which were then used to construct a brain functional network.The topological parameters of the network were subsequently extracted and input into a machine learning model for training.The results indicate that most of the classifiers achieved accuracy rates exceeding 70%.Specifically,the Logistic algorithm achieved an accuracy of 81.67%.Therefore,it is possible to predict target camouflage effectiveness with high accuracy without the need to calculate discovery probability.The proposed method fully considers the aspects of human visual and cognitive processes,overcomes the subjectivity of human interpretation,and achieves stable and reliable accuracy.
基金financial supports from the National Natural Science Foundation of China(Grant Nos.51925503&52105575)the Fundamental Research Funds for the Central Universities(Grant No.QTZX23063)+2 种基金the Aeronautical Science Foundation of China(Grant No.2022Z073081001)the Postdoctoral Fellowship Program of CPSF(Grant No.GZC20232028)the Open Research Funds of State Key Laboratory of Intelligent Manufacturing Equipment and Technology(Grant No.IMETKF2024008).
文摘The combination of advanced photoelectric detectors has rendered single-band camouflage materials ineffective,necessitating the development of infrared multispectral camouflage.However,the design and fabrication of existing works remain complex as they usually require the integration of multiscale structures.Here,we introduce phase modulation into the infrared camouflage metasurfaces with metal-dielectric-metal configuration,enabling them to achieve camouflage across more bands.Based on this strategy,a simple but effective single-layer cascaded metasurface is demonstrated for the first time to achieve low reflection at multi-wavelength lasers,low infrared radiation in atmospheric windows,and broadband thermal management.As a proof-of-concept,a 4-inch sample with a minimum linewidth of 1.8μm is fabricated using photolithography.The excellent infrared multispectral camouflage performance is verified in experiments,showing low reflectance in 0.9–1.6μm,low infrared emissivity in mid-wavelength infrared(MWIR)and long-wavelength infrared(LWIR)bands,and high absorptance at the wavelength of 10.6μm.Meanwhile,broadband high emissivity in 5–8μm can provide high-performance radiative heat dissipation.When the input power is 1.57 W·cm^(-2),the surface/radiation temperature of the metasurface decreases by 5.3℃/18.7℃ compared to the reference.The proposed metasurface may trigger further innovation in the design and application of compact multispectral optical devices.
基金the National Natural Science Foundation of China for the support(No.51175101)on this paper.
文摘Combining deep-learning image inpainting algorithms with the microfluidic technology,the paper proposes a method to achieve dynamic stealth and camouflage by using a microfluidic vision camouflage system simulating the chameleon skin.The basic principle is to perceive color changes in the external environment and collect ambient image information,and then utilize the image inpainting algorithm to adjust the control signals of the microfluidic system in real time.The detailed working principle of the microfluidic vision camouflage system is presented,and the mechanism of generating control signals for the system through deep-learning image inpainting algorithms and image-processing techniques is elucidated.The camouflage effect of the chameleon skin is analyzed and evaluated using color similarity.Results indicate that the camouflaged images are consistent with the background environment,thereby improving the target’s stealth and maneuvering characteristics.The camouflage technology developed in the paper based on the microfluidic vision camouflage system can be applied to several situations,such as military camouflage uniforms,robot skins,and weapon equipment.
基金funded by the National Key R&D Program of China(2022YFF0706005)National Natural Science Foundation of China(12272407,62275269,62275271,62305387)+3 种基金Foundation of NUDT(ZK23-03)Hunan Provincial Natural Science Foundation of China(2022JJ40552,2023JJ40683)State Key Laboratory of High Performance Computing,NUDT(202201-12)the Hunan Provincial Innovation Foundation for Postgraduate,China(CX20230009).
文摘Most multispectral compatible infrared camouflage devices primarily focus on achieving low emissivity but neglect environmental emissivity matching when environmental emissivity exceeds that of the devices,this creates a"low-emissivity exposure"risk.To address this issue,we develop a tunable multispectral compatible infrared camouflage device using phase change material In3SbTe2(IST).Simulation and experimental results demonstrate that in both the amorphous(aIST)and crystalline(cIST)states,the device achieves simulated plant infrared camouflage and ultra-low emissivity infrared camouflage within the atmospheric window bands(3–5μm and 8–14μm).To address thermal management,it utilizes two non-atmospheric window bands(2.5–3μm and 5–8μm)for heat dissipation.Additionally,laser stealth is realized at three specific wavelengths(1.064μm,1.55μm,and 10.6μm).In the visible spectrum,high absorptivity enables effective visible light camouflage.Adjusting the geometric parameters of top layer structure enables color variation.This work not only highlights potential applications in reversible switching,reconfigurable imaging,and dynamic coding using IST but also offers an effective strategy to counter multispectral detection technology.
基金supported by the National Natural Science Foundation of China(Nos.52003121,2220081350 and 22301111).
文摘This study serves as a guide to the development of a polydimethylsiloxane(PDMS)-encapsulated liquid metal-MXene aerogel,which has proven to be highly effective for electromagnetic wave absorption,particularly in saline environments.Through directional freezing and casting techniques,we have optimized the sample to exhibit enhanced absorption properties,achieving a reflection loss peak of-63.10 dB at 14.36 GHz.Variations in liquid metal content were found to significantly impact the complex permittivity of the aerogel,resulting in decreases observed in both real and imaginary components.This underscores the crucial role of conductivity in electromagnetic wave damping.Simultaneously,increases in tangent loss and attenuation constant highlight the vital contribution of MXene towards dissipating electromagnetic energy.Our best sample exhibits enhanced mechanical robustness,as evidenced by a high tensile modulus of 1 MPa.Notably,this exceptional performance is sustained for an extended period of 4 weeks even under harsh conditions such as high temperature,acid mist exposure,alkaline exposure,and immersion in synthetic seawater.By testing the thermal camouflage performance,samples achieved processable and efficient camouflage performance at multiple temperatures.This comprehensive dataset confirms the adaptability of the PDMS-encapsulated liquid metal-MXene aerogel as an effective solution for electromagnetic wave absorption in challenging environmental scenarios.
基金the National Key Research and Development Program of China(No.2022ZD0210500)the National Natural Science Foundation of China(Nos.61972067,U21A20491,and 62103437)the Dalian Outstanding Youth Science Foundation(No.2022RJ01)。
文摘Deep neural networks,especially face recognition models,have been shown to be vulnerable to adversarial examples.However,existing attack methods for face recognition systems either cannot attack black-box models,are not universal,have cumbersome deployment processes,or lack camouflage and are easily detected by the human eye.In this paper,we propose an adversarial pattern generation method for face recognition and achieve universal black-box attacks by pasting the pattern on the frame of goggles.To achieve visual camouflage,we use a generative adversarial network(GAN).The scale of the generative network of GAN is increased to balance the performance conflict between concealment and adversarial behavior,the perceptual loss function based on VGG19 is used to constrain the color style and enhance GAN’s learning ability,and the fine-grained meta-learning adversarial attack strategy is used to carry out black-box attacks.Sufficient visualization results demonstrate that compared with existing methods,the proposed method can generate samples with camouflage and adversarial characteristics.Meanwhile,extensive quantitative experiments show that the generated samples have a high attack success rate against black-box models.
基金the National Natural Science Foundation of China(52090034,52273064,52221006)the Fundamental Research Funds for the Central Universities(JD2417)is gratefully acknowledged.
文摘Although multifunctional electromagnetic interference(EMI)shielding materials with ultrahigh electromagnetic wave absorption are highly required to solve increasingly serious electromagnetic radiation and pollution and meet multi-scenario applications,EMI shielding materials usually cause a lot of reflection and have a single function.To realize the broadband absorption-dominated EMI shielding via absorption-reflection-reabsorption mechanisms and the interference cancelation effect,multifunctional asymmetric bilayer aerogels are designed by sequential printing of a MXene-graphene oxide(MG)layer with a MG emulsion ink and a conductive MXene layer with a MXene ink and subsequent freeze-drying for generating and solidifying numerous pores in the aerogels.The top MG layer of the asymmetric bilayer aerogel optimizes impedance matching and achieves re-absorption,while the bottom MXene layer enhances the reflection of the incident electromagnetic waves.As a result,the asymmetric bilayer aerogel achieves an average absorption coefficient of 0.95 in the X-band and shows the tunable absorption ability to electromagnetic wave in the ultrawide band from 8.2 to 40 GHz.Finite element simulations substantiate the effectiveness of the asymmetric bilayer aerogel for electromagnetic wave absorption.The multifunctional bilayer aerogels exhibit hydrophobicity,thermal insulation and Joule heating capacities and are efficient in solar-thermal/electric heating,infrared stealth,and clean-up of spilled oil.
基金National Natural Science Foundation of China(Grant Nos.62005049 and 62072110)Natural Science Foundation of Fujian Province(Grant No.2020J01451).
文摘Accurate segmentation of camouflage objects in aerial imagery is vital for improving the efficiency of UAV-based reconnaissance and rescue missions.However,camouflage object segmentation is increasingly challenging due to advances in both camouflage materials and biological mimicry.Although multispectral-RGB based technology shows promise,conventional dual-aperture multispectral-RGB imaging systems are constrained by imprecise and time-consuming registration and fusion across different modalities,limiting their performance.Here,we propose the Reconstructed Multispectral-RGB Fusion Network(RMRF-Net),which reconstructs RGB images into multispectral ones,enabling efficient multimodal segmentation using only an RGB camera.Specifically,RMRF-Net employs a divergentsimilarity feature correction strategy to minimize reconstruction errors and includes an efficient boundary-aware decoder to enhance object contours.Notably,we establish the first real-world aerial multispectral-RGB semantic segmentation of camouflage objects dataset,including 11 object categories.Experimental results demonstrate that RMRF-Net outperforms existing methods,achieving 17.38 FPS on the NVIDIA Jetson AGX Orin,with only a 0.96%drop in mIoU compared to the RTX 3090,showing its practical applicability in multimodal remote sensing.
文摘Video camouflaged object detection(VCOD)has become a fundamental task in computer vision that has attracted significant attention in recent years.Unlike image camouflaged object detection(ICOD),VCOD not only requires spatial cues but also needs motion cues.Thus,effectively utilizing spatiotemporal information is crucial for generating accurate segmentation results.Current VCOD methods,which typically focus on exploring motion representation,often ineffectively integrate spatial and motion features,leading to poor performance in diverse scenarios.To address these issues,we design a novel spatiotemporal network with an encoder-decoder structure.During the encoding stage,an adjacent space-time memory module(ASTM)is employed to extract high-level temporal features(i.e.,motion cues)from the current frame and its adjacent frames.In the decoding stage,a selective space-time aggregation module is introduced to efficiently integrate spatial and temporal features.Additionally,a multi-feature fusion module is developed to progressively refine the rough prediction by utilizing the information provided by multiple types of features.Furthermore,we incorporate multi-task learning into the proposed network to obtain more accurate predictions.Experimental results show that the proposed method outperforms existing cutting-edge baselines on VCOD benchmarks.
基金This work was supported by the National Natural Science Foundation of China(grant numbers 21808086)Natural Science Foundation of Jiangsu Province(Grant numbers BK20191334)Fundamental Research Funds for the Central Universities(Grant numbers JUSRP21933).
文摘Due to Visible light and Near-Infrared(Vis–NIR)stealth play an important role in the commercial,military,and scientific fields,camouflage materials related to it attracted increasing attention in decades.Green plant leaves,as the most extensive background materials on the earth,were widely simulated in the camouflage materials.However,difficult full-spectrum simulation(380–2500 nm),low-similarity simulation and the complex preparation have been great challenges for Vis–NIR Camouflage Materials(Vis–NIR-CMs).Herein,basing on the color-matching principle,two novel Vis–NIR-CMs including Dark Green Materials and Light Green Materials(DGM and LGM)were facilely fabricated by simple printing organic disperse dyes including C.I.Disperse Blue 291,C.I.Disperse Yellow 114,and C.I.Disperse Orange 30(B-291,Y-114 and O-30),and titanium dioxide(TiO_(2))on the viscose fabrics.Based on the excellent red edge property of B-291 and high scattering ability of TiO2,DGM and LGM exhibited generally high spectral correlation coefficients r_(m)(>0.95)with green plant leaves.Moreover,with the great color performance,excellent objects covering performance,low areal density(<146.3 g cm^(−2)),high tensile strength(>7.7 MPa),high softness(>81.27),high air permeability(>45.848 mm s^(−1)),DGM and LGM showed good simulation performance and wearing comfort to satisfy the application needs.This work presents a high-similarity Vis–NIR-CMs as a reference for full-spectrum camouflage materials,as well as low-cost and efficient preparation method is beneficial to the development of camouflage field.
基金National Natural Science Foundation of China(grant number 61801512,grant number 62071484)Natural Science Foundation of Jiangsu Province(grant number BK20180080)to provide fund for conducting experiments。
文摘The object detectors can precisely detect the camouflaged object beyond human perception.The investigations reveal that the CNNs-based(Convolution Neural Networks)detectors are vulnerable to adversarial attacks.Some works can fool detectors by crafting the adversarial camouflage attached to the object,leading to wrong prediction.It is hard for military operations to utilize the existing adversarial camouflage due to its conspicuous appearance.Motivated by this,this paper proposes the Dual Attribute Adversarial Camouflage(DAAC)for evading the detection by both detectors and humans.Generating DAAC includes two steps:(1)Extracting features from a specific type of scene to generate individual soldier digital camouflage;(2)Attaching the adversarial patch with scene features constraint to the individual soldier digital camouflage to generate the adversarial attribute of DAAC.The visual effects of the individual soldier digital camouflage and the adversarial patch will be improved after integrating with the scene features.Experiment results show that objects camouflaged by DAAC are well integrated with background and achieve visual concealment while remaining effective in fooling object detectors,thus evading the detections by both detectors and humans in the digital domain.This work can serve as the reference for crafting the adversarial camouflage in the physical world.
基金supported by the National Natural Science Foundation of China(Grant Nos.61727823,51873160)the joint research project of Health and Education Commission of Fujian Province(Grant No.2019-WJ-20).
文摘Semiconducting conjugated polymer nanoparticles(SPNs)represent an emerging class of phototheranostic materi-als with great promise for cancer treatment.In this report,low-bandgap electron donoracceptor(DA)-conjugated SPNs with sur-face cloaked by red blood cell membrane(RBCM)are developed for highly e ective photoacoustic imaging and photothermal therapy.The resulting RBCM-coated SPN(SPN@RBCM)displays remarkable near-infrared light absorption and good photosta-bility,as well as high photothermal conver-sion e ciency for photoacoustic imaging and photothermal therapy.Particularly,due to the small size(<5 nm),SPN@RBCM has the advantages of deep tumor penetration and rapid clearance from the body with no appreciable toxicity.The RBCM endows the SPNs with prolonged systematic circulation time,less reticuloendothelial system uptake and reduced immune-recognition,hence improving tumor accumulation after intravenous injection,which provides strong photoacoustic signals and exerts excellent photothermal therapeutic e ects.Thus,this work provides a valuable paradigm for safe and highly e cient tumor pho-toacoustic imaging and photothermal therapy for further clinical translation.
基金Program for Changjiang Scholars,Innovative Research Teamin University(No.IRT0654)ZSTU-Esquel Eco-textile Research Center
文摘There are two major camouflage protections in modern military tactics:UV-protection and near infrared camouflage.However,not all natural and composite dyestuffs provide the mentioned properties.In this study,the cotton fabric was dyed with natural indigo and the natural indigo dyeing process was optimized.Green leaves were chosen as the simulating object,and the camouflage properties of the dyed cotton fabric were evaluated.It was observed that the dyed cotton fabric had good UV-protection and near-infrared camouflage properties.The UV-protection effect was strongly dependent on the absorption characteristics of natural indigo for UV radiation.The near infrared camouflage effect was mainly dependent on the reflection spectrum characteristics of natural indigo in the near infrared waveband.
基金Natural Science Foundation of Jiangsu Province&Key Laboratory Foundation,grant number is BK20180579&6142206180204 respectively.
文摘The evaluation index of camouflage patterns is important in the field of military application.It is the goal that researchers have always pursued to make the computable evaluation indicators more in line with the human visual mechanism.In order to make the evaluation method more computationally intelligent,a Multi-Feature Camouflage Fused Index(MF-CFI)is proposed based on the comparison of grayscale,color and texture features between the target and the background.In order to verify the effectiveness of the proposed index,eye movement experiments are conducted to compare the proposed index with existing indexes including Universal Image Quality Index(UIQI),Camouflage Similarity Index(CSI)and Structural Similarity(SSIM).Twenty-four different simulated targets are designed in a grassland background,28 observers participate in the experiment and record the eye movement data during the observation process.The results show that the highest Pearson correlation coefficient is observed between MF-CFI and the eye movement data,both in the designed digital camouflage patterns and largespot camouflage patterns.Since MF-CFI is more in line with the detection law of camouflage targets in human visual perception,the proposed index can be used for the comparison and parameter optimization of camouflage design algorithms.
基金supported by grants from the Basic Science Research Program(2021M3H4A1A03047327 and 2022R1A2C3006227)through the National Research Foundation of Korea,funded by the Ministry of Science,ICT,and Future Planningthe Fundamental R&D Program for Core Technology of Materials and the Industrial Strategic Technology Development Program(20020855),funded by the Ministry of Trade,Industry,and Energy,Republic of Korea+2 种基金the National Research Council of Science&Technology(NST),funded by the Korean Government(MSIT)(CRC22031-000)partially supported by POSCO and Hyundai Mobis,a start-up fund(S-2022-0096-000)the Postdoctoral Research Program of Sungkyunkwan University(2022).
文摘Multifunctional,flexible,and robust thin films capable of operating in demanding harsh temperature environments are crucial for various cutting-edge applications.This study presents a multifunctional Janus film integrating highly-crystalline Ti_(3)C_(2)T_(x) MXene and mechanically-robust carbon nanotube(CNT)film through strong hydrogen bonding.The hybrid film not only exhibits high electrical conductivity(4250 S cm^(-1)),but also demonstrates robust mechanical strength and durability in both extremely low and high temperature environments,showing exceptional resistance to thermal shock.This hybrid Janus film of 15μm thickness reveals remarkable multifunctionality,including efficient electromagnetic shielding effectiveness of 72 dB in X band frequency range,excellent infrared(IR)shielding capability with an average emissivity of 0.09(a minimal value of 0.02),superior thermal camouflage performance over a wide temperature range(−1 to 300℃)achieving a notable reduction in the radiated temperature by 243℃ against a background temperature of 300℃,and outstanding IR detection capability characterized by a 44%increase in resistance when exposed to 250 W IR radiation.This multifunctional MXene/CNT Janus film offers a feasible solution for electromagnetic shielding and IR shielding/detection under challenging conditions.
文摘Camouflage is ubiquitous in the natural world and benefits both predators and prey. Amongst the range of conceal- ment strategies, disruptive coloration is thought to visually fragment an animal＇s＇ outline, thereby reducing its rate of discovery. Here, I propose two non-mutually exclusive hypotheses for how disruptive camouflage functions, and describe the visual me- chanisms that might underlie them. （1） The local edge disruption hypothesis states that camouflage is achieved by breaking up edge information. （2） The global feature disruption hypothesis states camouflage is achieved by breaking up the characteristic features of an animal （e.g., overall shape or facial features）. Research clearly shows that putatively disruptive edge markings do increase concealment; however, few tests have been undertaken to determine whether this survival advantage is attributable to the distortion of features, so the global feature disruption hypothesis is under studied. In this review the evidence for global feature disruption is evaluated. Further, I address if object recognition processing provides a feasible mechanism for animals＇ features to influence concealment. This review concludes that additional studies are needed to test if disruptive camouflage operates through the global feature disruption and proposes future research directions [Current Zoology 61 （4）： 708-717, 2015].
基金supported by a grant from NSFC (30770332)The Ministry of Education (MOE) Academic Research Fund (AcRF)(R-154-000-335-112)
文摘Camouflage is one of the most widespread and powerful strategies that animals use to make detection/recognition more difficult. Many orb-web spiders of the genus Cyclosa add prey remains, plant debris, moults, and/or eggsacs to their webs called web decorations. Web decorations resembling spider body colour pattern have been considered to camouflage the spider from predators. While this camouflage is obvious from a human＇s perspective, it has rarely been investigated from a predator＇s perspective. In this study, we tested the visibility of web decorations by calculating chromatic and achromatic contrasts of detritus and eggsae decorations built by Cyclosa octotubereulata, against four different backgrounds viewed by both bird （e.g., blue tits） and hymenopteran （e.g. wasps） predators. We showed that both juvenile and adult spiders on webs with detritus or egg-sac deco- rations were undetectable by both hymenopteran and bird predators over short and long distances. Our results thus suggest that decorating webs with detritus or eggsacs by C octotuberculata may camouflage the spiders from both hymenopteran and bird predators in their common habitats [Current Zoology 56 （3）： 379-387, 2010].
文摘The round-tailed homed lizard Phrynosoma modestum is cryptically colored and resembles a small stone when it draws legs close to its body and elevates its back. We investigated effectiveness of camouflage in P. modestum and its dependence on stones by placing a lizard in one of two microhabitats （uniform sand or sand with surface rocks approximately the same size as lizards）. An observer who knew which microhabitat contained the lizard was asked to locate the lizard visually. Latency to detec- tion was longer and probability of no detection within 60 s was higher for lizards on rock background than on bare sand. In arenas where lizards could choose to occupy rock or bare sand, much higher proportions selected rocky backgrounds throughout the day; at night all lizards slept among stones. A unique posture gives P modestum a rounded appearance similar to many natural stones. Lizards occasionally adopted the posture, but none did so in response to a nearby experimenter. Stimuli that elicit the posture are unknown. That P. modestum is better camouflaged among rocks than on bare sand and prefers to occupy rocky areas suggests that special resemblance to rocks （masquerade） enhances camouflage attributable to coloration and immobility.
基金the National Natural Science Foundation of China for the support(No.51175101)on this paper.
文摘To adapt to a complex and variable environment,self-adaptive camouflage technology is becoming more and more important in all kinds of military applications by overcoming the weakness of the static camouflage.In nature,the chameleon can achieve self-adaptive camouflage by changing its skin color in real time with the change of the background color.To imitate the chameleon skin,a camouflaged film controlled by a color-changing microfluidic system is proposed in this paper.The film with microfluidic channels fabricated by soft materials can achieve dynamic cloaking and camouflage by circulating color liquids through channels inside the film.By sensing and collecting environmental color change information,the control signal of the microfluidic system can be adjusted in real time to imitate chameleon skin.The microstructure of the film and the working principle of the microfluidic color-changing system are introduced.The mechanism to generate the control signal by information processing of background colors is illustrated.“Canny”double-threshold edge detection algorithm and color similarity are used to analyze and evaluate the camouflage.The tested results show that camouflaged images have a relatively high compatibility with environmental backgrounds and the dynamic cloaking eff ect can be achieved.
