This paper addresses the verification of strong currentstate opacity with respect to real-time observations generated from a discrete-event system that is modeled with time labeled Petri nets. The standard current-sta...
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This paper addresses the verification of strong currentstate opacity with respect to real-time observations generated from a discrete-event system that is modeled with time labeled Petri nets. The standard current-state opacity cannot completely characterize higher-level security. To ensure the higher-level security requirements of a time-dependent system, we propose a strong version of opacity known as strong current-state opacity. For any path(state-event sequence with time information)π derived from a real-time observation that ends at a secret state, the strong current-state opacity of the real-time observation signifies that there is a non-secret path with the same real-time observation as π. We propose general and non-secret state class graphs, which characterize the general and non-secret states of time-dependent systems, respectively. To capture the observable behavior of non-secret states, a non-secret observer is ***, we develop a structure called a real-time concurrent verifier to verify the strong current-state opacity of time labeled Petri nets. This approach is efficient since the real-time concurrent verifier can be constructed by solving a certain number of linear programming problems.
Moles exhibit highly effective capabilities due to their unique body structures and digging techniques,making them ideal models for biomimetic ***,a major challenge for mole-inspired robots lies in overcoming resistan...
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Moles exhibit highly effective capabilities due to their unique body structures and digging techniques,making them ideal models for biomimetic ***,a major challenge for mole-inspired robots lies in overcoming resistance in granular media when burrowing with *** the absence of effective forepaw design strategies,most robotic designs rely on increased power to enhance *** address this issue,this paper employs Resistive Force Theory to optimize mole-inspired forepaws,aiming to enhance burrowing *** analyzing the relationship between geometric parameters and burrowing forces,we propose several forepaw design *** granular resistance assessments,an effective forepaw configuration is identified and further refined using parameters such as longitudinal and transverse ***,the Particle Swarm Optimization algorithm is applied to determine the optimal forepaw *** force-loading tests,the optimized forepaw demonstrated a 79.44%reduction in granular lift force and a 22.55%increase in propulsive force compared with the control *** robotic burrowing experiments,the optimized forepaw achieved the longest burrow displacement(179.528 mm)and the lowest burrowing lift force(0.9355 mm/s),verifying its effectiveness in reducing the lift force and enhancing the propulsive force.
Preface: 4th International e-Conference on Recent Advancement in mechanicalengineering and technology (ICRAMET 2021), AIP Conference Proceedings, Volume 2523,
Preface: 4th International e-Conference on Recent Advancement in mechanicalengineering and technology (ICRAMET 2021), AIP Conference Proceedings, Volume 2523,
This study focuses on combining spent alumina catalyst (SAC) with carbonized date palm fiber (CDPF) to create a hybrid combination that is integrated into a metal matrix using waste aluminum. The research takes a thor...
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The goal of infrared and visible image fusion(IVIF)is to integrate the unique advantages of both modalities to achieve a more comprehensive understanding of a scene. However, existing methods struggle to effectively h...
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The goal of infrared and visible image fusion(IVIF)is to integrate the unique advantages of both modalities to achieve a more comprehensive understanding of a scene. However, existing methods struggle to effectively handle modal disparities,resulting in visual degradation of the details and prominent targets of the fused images. To address these challenges, we introduce Prompt Fusion, a prompt-based approach that harmoniously combines multi-modality images under the guidance of semantic prompts. Firstly, to better characterize the features of different modalities, a contourlet autoencoder is designed to separate and extract the high-/low-frequency components of different modalities, thereby improving the extraction of fine details and textures. We also introduce a prompt learning mechanism using positive and negative prompts, leveraging Vision-Language Models to improve the fusion model's understanding and identification of targets in multi-modality images, leading to improved performance in downstream tasks. Furthermore, we employ bi-level asymptotic convergence optimization. This approach simplifies the intricate non-singleton non-convex bi-level problem into a series of convergent and differentiable single optimization problems that can be effectively resolved through gradient *** approach advances the state-of-the-art, delivering superior fusion quality and boosting the performance of related downstream tasks. Project page: https://***/hey-it-s-me/PromptFusion.
Cryorolling, an approach involving severe plastic deformation, offers a means to fabricate aluminum alloy sheets (AA7075) with exceptionally fine grains, conferring greater strength and hardness than those achieved th...
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Rotational feeding combined with shift feeding electrochemical trepanning(RF-SF ECTr) is an effective method for machining aeroengine blisks. However, given the variable relative motion of the electrodes and the compl...
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Rotational feeding combined with shift feeding electrochemical trepanning(RF-SF ECTr) is an effective method for machining aeroengine blisks. However, given the variable relative motion of the electrodes and the complex flow channels around the bending and twisting blades, the accessibility and uniformity of the flow field are poor in blisk RF-SF ECTr using the traditional electrolyte supply(TES) mode, resulting in poor machining stability and low machining efficiency. To improve the distribution of the flow field, a new multi-channel electrolyte supply(MCES) mode is proposed for blisk RF-SF ECTr, in which the position and volume of the electrolyte supply are controlled effectively by setting multiple inlet channels in the liquid inlet area. A flow-field simulation comparison between TES and MCES shows that better accessibility and uniformity of the flow-field distribution are achieved under MCES. To clarify further the flow-field distribution characteristics under RF-SF ECTr, a series of flow-field simulations was conducted at different machining depths. Based on the obtained dynamic change law for the flow field, to enhance further its uniformity and accessibility, a global coverage strategy for the electrolyte supply and a flow-field structure optimization method for MCES are proposed, which involve optimizing the number, diameter, and location of the inlet channels. After many simulations, the optimal MCES structure was achieved whereby the electrolyte covers all positions effectively in the processing area. To verify the proposed method as effective and correct, a series of RF-SF ECTr experiments was carried out. Under the optimized MCES mode, the feeding rate was increased from 0.8 mm/min with the TES mode to 2.0 mm/min, and the processing stability and efficiency were improved significantly. The methods presented here offer an effective guide for flow-field optimization when machining other components with complex spatial structures.
The ability to perform against extreme corrosion environments in stainless steel depreciates under challenging conditions in industrial *** can be resolved by employing surface modification techniques to modify the su...
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The ability to perform against extreme corrosion environments in stainless steel depreciates under challenging conditions in industrial *** can be resolved by employing surface modification techniques to modify the surface with the required *** present study investigates the outcomes of friction stir processing of SS304 with CoCrFeCuTi high entropy alloy(HEA)as reinforcement and the property enhancements *** synthesized CoCrFeCuTi HEA exhibited irregular fragments with 17μm mean particle size and body centred cubic(BCC)*** microstructure of the processed surface revealed ultra-refined grains with a uniform distribution of HEA *** microstructures of the samples annealed at 400℃,550℃,700℃and 850℃for 2 h also showed significant grain growth and grain *** processed sample with HEA reinforcement annealed at 700℃exhibited enhanced microhardness and tensile strength by 63%and 0.88 times than that of the processed sample with HEA *** subsequent electrochemical corrosion test displayed better corrosion resistance for the HEA-processed and annealed *** corrosion tests at 900℃showcased excellent resistance for the HEA processed and annealed samples by 14.92%,12.75%,and 14.83%against the samples pre-annealed under three different salt mixtures,and the corroded surface was analyzed.
Equal channel angle pressing is recognized for its ability to refine alloy grains and alter grain orientation, thereby achieve better mechanical performance of the magnesium alloy. This study investigates the microstr...
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Equal channel angle pressing is recognized for its ability to refine alloy grains and alter grain orientation, thereby achieve better mechanical performance of the magnesium alloy. This study investigates the microstructures,dynamic recrystallization mechanism, texture development, and mechanical performance of GW94K(Mg–8.7Gd–4.18Y–0.42Zr wt. %) Mg alloy following ECAP-4 passes at 400°C and 3 mm/min. Results show that when high-temperature deformation is undertaken, twin formation is suppressed while dislocation slip is facilitated, increasing dislocation density during deformation. Following ECAP deformation, the sample displayed higher fracture elongation, TYS, and UTS than the as-solutioned GW94K alloy. In particular, the GW94K alloy performed well mechanically after ECAP-4 passes, with an ultimate TYS of 231 MPa, an UTS of 290 MPa, and an elongation of 14.8 %. DDRX and shear bands induce CDRX, both of which are important in plastic deformation. as well as in modifying microstructure and grain orientation during ECAP deformation.
Manufacturers must be able to figure out the most suitable technique capable of generating rapid and accurate performance when developing a precise modelling approach for the development of an efficient machining proc...
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