Intellectual property （IP） protection is one of the hardcore problems in hardware security. Semiconductor industry still lacks effective and proactive defense to shield IPs from reverse engineering （RE） based atta...Intellectual property （IP） protection is one of the hardcore problems in hardware security. Semiconductor industry still lacks effective and proactive defense to shield IPs from reverse engineering （RE） based attacks. Integrated circuit （IC） camouflaging technique fills this gap by replacing some conventional logic gates in tile IPs with specially designed logic cells （called camouflaged gates） without changing the functions of tile IPs. The camouflaged gates can perform different logic functions while maintaining an identical look to RE attackers, thus preventing them from obtaining the layout information of the IP directly from RE tools. Since it was first proposed in 2012, circuit camouflaging has become one of the hottest research topics in hardware security focusing on two fundamental problems. How to choose the types of camouflaged gates and decide where to insert them in order to simultaneously minimize the performance overhead and optimize the RE complexity？ How can an attacker de-camouflage a camouflaged circuit and complete the RE attack？ In this article, we review the evolution of circuit camouflaging through this spear and shield race. First, we introduce the design methods of four different kinds of camouflaged ceils based on true/dummy contacts, static random access memory （SRAM）, doping, and emerging devices, respectively. Then we elaborate four representative de-camouflaging attacks： brute force attack, IC testing based attack, satisfiability-based （SAT-based） attack, and the circuit partition based attack, and the corresponding countermeasures： clique-based camouflaging, CamoPerturb, AND-tree camouflaging, and equivalent class based camouflaging, respectively. We argue that the current research efforts should be on reducing overhead introduced by circuit camouflaging and defeating decamouflaging attacks. We point out that exploring features of emerging devices could be a promising direction. Finally, as a complement to circuit camouflaging, we conclude with a brief review of other state-of-the-art IP protection techniques.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
A laser-induced periodic surface structure(LIPSS),which can be easily produced by femtosecond laser ablation,is a unique nanostructure with a visible refractive color that can be controlled by altering its orientation...A laser-induced periodic surface structure(LIPSS),which can be easily produced by femtosecond laser ablation,is a unique nanostructure with a visible refractive color that can be controlled by altering its orientation and uniformity,making it suitable for use in colorful marking,camouflage,and anticounterfeiting measures.However,single-mode information camouflage can no longer meet increasingly higher-level security requirements.Therefore,metasurfaces offer revolutionary solutions.In this study,conceptual metasurfaces of pure tungsten are theoretically proposed and verified using hierarchical LIPSS/nanoparticle(NP)nanostructures as meta-atoms.The anisotropy of the LIPSS nanostructure enables polarization-sensitive optical modulation,whereas the spatial configuration,NPs size,and period of LIPSS in the LIPSS/NP meta-atoms provide flexibility for tailoring broadband optical responses.In xpolarization,the LIPSS/NP meta-atom system provides more visible colors and divergent infrared absorption(emission)than in y-polarized and unpolarized modes,paving the way for vividly colorful polarization-sensitive displays and information camouflage in infrared bands.A simplified rendition of the world-famous painting“The Starry Night”by Van Gogh is used as a proof-of-concept.Preliminary experimental results are presented,based on which the feasibility and challenges for laser nanomanufacturing of the proposed conceptual metasurfaces are discussed,aiming to provide inspiration for the development of novel metasurfaces through interdisciplinary studies.展开更多
Li Jiayue,a talented artist from Beichuan Qiang Autonomous County,China,has captivated(迷住)audiences with his remarkable optical illusions.Although he initially studied electrical automation,Li's passion for art ...Li Jiayue,a talented artist from Beichuan Qiang Autonomous County,China,has captivated(迷住)audiences with his remarkable optical illusions.Although he initially studied electrical automation,Li's passion for art led him to a career dedicated to creating stunning visual illusions.Using his exceptional painting skills,Li camouflages objects like lamp posts,tree trunks and even large buildings,blending them seamlessly with their surroundings in a way that confuses the eye and captivates the mind.He meticulously studies the textures,colors and patterns of the environment,ensuring that each stroke of his brush perfectly matches the background.This attention to detail allows him to create illusions that are not only visually striking but also incredibly convincing,making it difficult for viewers to distinguish between what is real and what is an illusion.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
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
Concerning the capture problem against arbitrary maneuvering targets,whose overload is high maneuvering but upper bounded and velocity has advantages,this paper elucidates a three-dimensional multi-constraint analytic...Concerning the capture problem against arbitrary maneuvering targets,whose overload is high maneuvering but upper bounded and velocity has advantages,this paper elucidates a three-dimensional multi-constraint analytical capture zone,exhibiting prominent guiding significance to the initial states of the terminal guidance.Unlike most existing capture zone studies,which are represented by initial relative velocity,the proposed capture zone investigates the initial velocity heading angle and side-window angle.First,the asymptotic fast convergence anti-interference guidance law is presented via motion camouflage theory,and it meets the Field of View(FOV)constraint by theoretical analysis.On this basis,the capture zone is derived with overload limits based on the Lyapunov-based function.Then,it is converted to the form defined by the velocity heading and side-window angles,considering the FOV constraint.Finally,the sensitivity of the capture zone to the designed guidance algorithm’s different influencing factors and the gain boundary are deduced and analyzed to provide a theoretical basis for augmenting the analytical capture zone during a practical engagement.The findings reveal the capture zone correlation mechanism of terminal guidance law and give academic support to the subsequent acquisition of arbitrary maneuvering targets,which has potential application value.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
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
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
The matching performance among the visible and near infrared coating.the low infrared emitting coating and the microwave absorbing coating was investigated.Experimental results show that the resulting malerial is char...The matching performance among the visible and near infrared coating.the low infrared emitting coating and the microwave absorbing coating was investigated.Experimental results show that the resulting malerial is characteristic of wideband effect ranging from the visible,near infrared and 3-5μm,8-14μm infrared protion of the spectrum,as well as the radar region from 8 to 18GHz when these three materials form αlayerstructure material system.The microwave absorbing ability of material is hardly changed.The resonance peak moves towards lower frequency as the thickness of the visible,near infrared coating and the low infrared emitting coating increases.This problem can be resolved by controlling the thickness of the matrial.On the other hand, the infrared emissivity εof the material system increases as the thickness of the visible,near infrared coating increases.This can be resolved by increasing infrared transparency of the visible and near infrared topcoating or controlling its thickness.The experimental resulting material system has spectral reflection characteristics in visible and near infrared regions that are similar to those of the natural background.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
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 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
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
This paper proposes a cooperative guidance law for attacking a ground target with the impact angle constraint based on the motion camouflage strategy in the line-of-sight(LOS)frame.A dynamic model with the impact angl...This paper proposes a cooperative guidance law for attacking a ground target with the impact angle constraint based on the motion camouflage strategy in the line-of-sight(LOS)frame.A dynamic model with the impact angle constraint is established according to the relative motion between multiple missiles and the target.The process of cooperative guidance law design is divided into two stages.Firstly,based on the undirected graph theory,a new finite-time consensus protocol on the LOS direction is derived to guarantee relative distances reach consensus.And the value of acceleration command is positive,which is beneficial for engineering realization.Secondly,the acceleration command on the normal direction of the LOS is designed based on motion camouflage and finite-time convergence,which can ensure the missiles reach the target with the desired angle and satisfy the motion camouflage state.The finitetime stability analysis is proved by the Lyapunov theory.Numerical simulations for stationary and maneuver targets have demonstrated the effectiveness of the cooperative guidance law proposed.展开更多
Porous SiC ceramics(PSCs)are promising lightweight and efficient thermal insulators that can evade infrared detection by reducing the surface temperature of the protected object,which plays a crucial role in the devel...Porous SiC ceramics(PSCs)are promising lightweight and efficient thermal insulators that can evade infrared detection by reducing the surface temperature of the protected object,which plays a crucial role in the development of new military equipment.However,the controllable synthesis of PSCs with both hierarchical pore structure and thermal/mechanical stability remains challenging.In this work,such PSCs were prepared by a facile foam-gelcasting/solid-state reaction method,using silicon powders and glucose-derived carbon as starting materials.The favorable dispersibility and wettability of hydrophilic carbon microspheres and the in-situ formed SiC guarantee the highly porous structure(92.8%porosity),comparable bulk density(0.20 g·cm^(-3))and reasonable mechanical property of the product.The designed PSCs performed outstanding high-temperature performance,especially thermal insulation in both oxidizing and inert atmospheres.More importantly,the composite architecture of PSCs and low emissivity layer(Al foil)exhibited desirable infrared stealth property(at a temperature up to 1100℃),significantly extending the operating temperature range of thermal camouflage material.The unique combination of excellent properties would make PSCs a potential candidate material for future thermal protection and infrared stealth applications in an extreme environment.展开更多
基金This work is supported by the National Natural Science Foundation of China under Grant No. 61774091. Gang Qu is supported in part by Air Force Office of Scientific Research Multi-University Research Initiative of USA under Award No. FA9550-14-1-0351.
文摘Intellectual property （IP） protection is one of the hardcore problems in hardware security. Semiconductor industry still lacks effective and proactive defense to shield IPs from reverse engineering （RE） based attacks. Integrated circuit （IC） camouflaging technique fills this gap by replacing some conventional logic gates in tile IPs with specially designed logic cells （called camouflaged gates） without changing the functions of tile IPs. The camouflaged gates can perform different logic functions while maintaining an identical look to RE attackers, thus preventing them from obtaining the layout information of the IP directly from RE tools. Since it was first proposed in 2012, circuit camouflaging has become one of the hottest research topics in hardware security focusing on two fundamental problems. How to choose the types of camouflaged gates and decide where to insert them in order to simultaneously minimize the performance overhead and optimize the RE complexity？ How can an attacker de-camouflage a camouflaged circuit and complete the RE attack？ In this article, we review the evolution of circuit camouflaging through this spear and shield race. First, we introduce the design methods of four different kinds of camouflaged ceils based on true/dummy contacts, static random access memory （SRAM）, doping, and emerging devices, respectively. Then we elaborate four representative de-camouflaging attacks： brute force attack, IC testing based attack, satisfiability-based （SAT-based） attack, and the circuit partition based attack, and the corresponding countermeasures： clique-based camouflaging, CamoPerturb, AND-tree camouflaging, and equivalent class based camouflaging, respectively. We argue that the current research efforts should be on reducing overhead introduced by circuit camouflaging and defeating decamouflaging attacks. We point out that exploring features of emerging devices could be a promising direction. Finally, as a complement to circuit camouflaging, we conclude with a brief review of other state-of-the-art IP protection techniques.
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financial support received from the Shanghai Pujiang Program(23PJ1406500).
文摘A laser-induced periodic surface structure(LIPSS),which can be easily produced by femtosecond laser ablation,is a unique nanostructure with a visible refractive color that can be controlled by altering its orientation and uniformity,making it suitable for use in colorful marking,camouflage,and anticounterfeiting measures.However,single-mode information camouflage can no longer meet increasingly higher-level security requirements.Therefore,metasurfaces offer revolutionary solutions.In this study,conceptual metasurfaces of pure tungsten are theoretically proposed and verified using hierarchical LIPSS/nanoparticle(NP)nanostructures as meta-atoms.The anisotropy of the LIPSS nanostructure enables polarization-sensitive optical modulation,whereas the spatial configuration,NPs size,and period of LIPSS in the LIPSS/NP meta-atoms provide flexibility for tailoring broadband optical responses.In xpolarization,the LIPSS/NP meta-atom system provides more visible colors and divergent infrared absorption(emission)than in y-polarized and unpolarized modes,paving the way for vividly colorful polarization-sensitive displays and information camouflage in infrared bands.A simplified rendition of the world-famous painting“The Starry Night”by Van Gogh is used as a proof-of-concept.Preliminary experimental results are presented,based on which the feasibility and challenges for laser nanomanufacturing of the proposed conceptual metasurfaces are discussed,aiming to provide inspiration for the development of novel metasurfaces through interdisciplinary studies.
文摘Li Jiayue,a talented artist from Beichuan Qiang Autonomous County,China,has captivated(迷住)audiences with his remarkable optical illusions.Although he initially studied electrical automation,Li's passion for art led him to a career dedicated to creating stunning visual illusions.Using his exceptional painting skills,Li camouflages objects like lamp posts,tree trunks and even large buildings,blending them seamlessly with their surroundings in a way that confuses the eye and captivates the mind.He meticulously studies the textures,colors and patterns of the environment,ensuring that each stroke of his brush perfectly matches the background.This attention to detail allows him to create illusions that are not only visually striking but also incredibly convincing,making it difficult for viewers to distinguish between what is real and what is an illusion.
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.
文摘Concerning the capture problem against arbitrary maneuvering targets,whose overload is high maneuvering but upper bounded and velocity has advantages,this paper elucidates a three-dimensional multi-constraint analytical capture zone,exhibiting prominent guiding significance to the initial states of the terminal guidance.Unlike most existing capture zone studies,which are represented by initial relative velocity,the proposed capture zone investigates the initial velocity heading angle and side-window angle.First,the asymptotic fast convergence anti-interference guidance law is presented via motion camouflage theory,and it meets the Field of View(FOV)constraint by theoretical analysis.On this basis,the capture zone is derived with overload limits based on the Lyapunov-based function.Then,it is converted to the form defined by the velocity heading and side-window angles,considering the FOV constraint.Finally,the sensitivity of the capture zone to the designed guidance algorithm’s different influencing factors and the gain boundary are deduced and analyzed to provide a theoretical basis for augmenting the analytical capture zone during a practical engagement.The findings reveal the capture zone correlation mechanism of terminal guidance law and give academic support to the subsequent acquisition of arbitrary maneuvering targets,which has potential application value.
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.
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The matching performance among the visible and near infrared coating.the low infrared emitting coating and the microwave absorbing coating was investigated.Experimental results show that the resulting malerial is characteristic of wideband effect ranging from the visible,near infrared and 3-5μm,8-14μm infrared protion of the spectrum,as well as the radar region from 8 to 18GHz when these three materials form αlayerstructure material system.The microwave absorbing ability of material is hardly changed.The resonance peak moves towards lower frequency as the thickness of the visible,near infrared coating and the low infrared emitting coating increases.This problem can be resolved by controlling the thickness of the matrial.On the other hand, the infrared emissivity εof the material system increases as the thickness of the visible,near infrared coating increases.This can be resolved by increasing infrared transparency of the visible and near infrared topcoating or controlling its thickness.The experimental resulting material system has spectral reflection characteristics in visible and near infrared regions that are similar to those of the natural background.
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This work was supported by the National Nature Science Foundation of China(11572097).
文摘This paper proposes a cooperative guidance law for attacking a ground target with the impact angle constraint based on the motion camouflage strategy in the line-of-sight(LOS)frame.A dynamic model with the impact angle constraint is established according to the relative motion between multiple missiles and the target.The process of cooperative guidance law design is divided into two stages.Firstly,based on the undirected graph theory,a new finite-time consensus protocol on the LOS direction is derived to guarantee relative distances reach consensus.And the value of acceleration command is positive,which is beneficial for engineering realization.Secondly,the acceleration command on the normal direction of the LOS is designed based on motion camouflage and finite-time convergence,which can ensure the missiles reach the target with the desired angle and satisfy the motion camouflage state.The finitetime stability analysis is proved by the Lyapunov theory.Numerical simulations for stationary and maneuver targets have demonstrated the effectiveness of the cooperative guidance law proposed.
基金financially supported by the National Natural Science Foundation of China (Nos.52072274,52272021 and 52232022)。
文摘Porous SiC ceramics(PSCs)are promising lightweight and efficient thermal insulators that can evade infrared detection by reducing the surface temperature of the protected object,which plays a crucial role in the development of new military equipment.However,the controllable synthesis of PSCs with both hierarchical pore structure and thermal/mechanical stability remains challenging.In this work,such PSCs were prepared by a facile foam-gelcasting/solid-state reaction method,using silicon powders and glucose-derived carbon as starting materials.The favorable dispersibility and wettability of hydrophilic carbon microspheres and the in-situ formed SiC guarantee the highly porous structure(92.8%porosity),comparable bulk density(0.20 g·cm^(-3))and reasonable mechanical property of the product.The designed PSCs performed outstanding high-temperature performance,especially thermal insulation in both oxidizing and inert atmospheres.More importantly,the composite architecture of PSCs and low emissivity layer(Al foil)exhibited desirable infrared stealth property(at a temperature up to 1100℃),significantly extending the operating temperature range of thermal camouflage material.The unique combination of excellent properties would make PSCs a potential candidate material for future thermal protection and infrared stealth applications in an extreme environment.
