Search Results (198)

Ghost imaging (GI) facilitates image acquisition under low-light conditions through single pixel measurements, thus holding tremendous potential across various fields such as biomedical imaging, remote sensing, defense and military applications, and 3D imaging. However, in order to reconstruct high-resolution images, GI typically requires a large number of single-pixel measurements, which imposes practical limitations on its application. Parallel ghost imaging addresses this issue by utilizing each pixel of a position-sensitive detector as a bucket detector to simultaneously perform tens of thousands of ghost imaging measurements in parallel. In this work, we explore the non-local characteristics of ghost imaging in depth, and by constructing a large speckle space, we achieve a reconstruction result in parallel ghost imaging where the field of view surpasses the limitations of the reference arm detector. Using a computational ghost imaging framework, after pre-recording the speckle patterns, we are able to complete X-ray ghost imaging at a speed of 6 min per sample, with image dimensions of 14,000 × 10,000 pixels (4.55 mm × 3.25 mm, millimeter-scale field of view) and a pixel resolution of 0.325 µm (sub-micron pixel resolution). We present this framework to enhance efficiency, extend resolution, and dramatically expand the field of view, with the aim of providing a solution for the practical implementation of ghost imaging. Full article

Recent technological advances have expanded the use of 3D-printed polymer components across industries, including a growing interest in military applications. The effective defensive use of such materials depends on a thorough understanding of polymer properties, printing techniques, structural design, and influencing parameters. This paper analyzes the ballistic resistance of 3D-printed polymer structures against 9 × 19 mm projectiles. Cuboid targets with different infill patterns—cubic, grid, honeycomb, and gyroid—were fabricated and tested experimentally using live ammunition. Post-impact, CT scans were used to non-destructively measure projectile penetration depths. The honeycomb infill demonstrated superior bullet-stopping performance. Additionally, mechanical properties were experimentally determined and applied in FEM simulations, confirming the ability of commercial software to predict projectile–target interaction in complex geometries. A simplified analytical model also produced satisfactory agreement with experimental observations. The results contribute to a better understanding of impact behavior in 3D-printed polymer structures, supporting their potential application in defense systems. Full article

The application fields of high-temperature titanium alloys are mainly concentrated in the aerospace, defense and military industries, such as the high-temperature parts of rocket and aircraft engines, missile cases, tail rudders, etc., which can greatly reduce the weight of aircraft while resisting high temperatures. However, traditional high-temperature titanium alloys containing multiple types of elements (more than six) have a complex impact on the solidification, deformation, and phase transformation processes of the alloys, which greatly increases the difficulty of casting and deformation manufacturing of aerospace and military components. Therefore, developing low-component high-temperature titanium alloys suitable for hot processing and forming is urgent. This study used data augmentation (Gaussian noise) to expedite the development of a novel quinary high-temperature titanium alloy. Utilizing data augmentation, the generalization abilities of four machine learning models (XGBoost, RF, AdaBoost, Lasso) were effectively improved, with the XGBoost model demonstrating superior prediction accuracy (with an R² value of 0.94, an RMSE of 53.31, and an MAE of 42.93 in the test set). Based on this model, a novel Ti-7.2Al-1.8Mo-2.0Nb-0.4Si (wt.%) alloy was designed and experimentally validated. The UTS of the alloy at 600 °C was 629 MPa, closely aligning with the value (649 MPa) predicted by the model, with an error of 3.2%. Compared to as-cast Ti1100 and Ti6242S alloy (both containing six elements), the novel quinary alloy has considerable high-temperature (600 °C) mechanical properties and fewer components. The microstructure analysis revealed that the designed alloy was an α+β type alloy, featuring a typical Widmanstätten structure. The fracture form of the alloy was a mixture of brittle and ductile fracture at both room and high temperatures. Full article

Scientific evaluation of architectural heritage value constitutes a crucial foundation for advancing effective conservation practices and guiding policy development. Fujian Tubao, a distinctive form of defensive vernacular architecture found in southeastern China, integrates military defense, residential functions, and clan-based social organization into a unified spatial structure, making it an important component of China’s regional cultural heritage. In response to current challenges of inadequate preservation and progressive loss of heritage value associated with Fujian Tubao, there is an urgent need to establish a systematic evaluation framework to support and inform conservation efforts. This study centered on Fujian Tubao and proposed a comprehensive value assessment system that could innovatively integrate Grounded Theory with the Analytic Hierarchy Process (AHP). The Grounded Theory was first adopted to extract value dimensions of architectural heritage and their underlying connotations, thereby forming a value cognition system. Subsequently, the AHP was applied to assign quantitative weights and establish the priority order of each dimension, ultimately constructing a value evaluation system that could identify core objects for heritage conservation and clarify the hierarchy of their relative importance. This study achieved methodological integration in both the value extraction and evaluation stages, overcoming limitations of a single-method approach in dimension identification and weight assignment. The framework ensures logical consistency in value structuring and enhances the scientific validity of results. This study formulated a standardized and replicable evaluation framework tailored to the heritage value of Fujian Tubao. It also provides theoretical support for future conservation planning and offers a methodological reference for value assessment across diverse categories of architectural heritage. Full article

Guomari fortress in eastern Qinghai Province exemplifies vernacular architecture shaped by multiethnic interaction, environmental adaptation, and localized defense strategies. Originally a Ming Dynasty military-agricultural outpost, it evolved into a Tu ethnic settlement. Fieldwork, including architectural surveys and spatial analysis, identified a three-tiered defensive system: (1) strategic use of terrain and rammed-earth walls; (2) labyrinthine alleys with L-, T-, and cross-shaped intersections; and (3) interconnected rooftops forming elevated circulation routes. Courtyards are categorized into single-line, L-shaped, U-shaped, and fully enclosed layouts, reflecting adaptations to terrain, ritual functions, and thermal needs. Architectural features such as thick loam-coated walls and flat roofs demonstrate climatic adaptation, while the integration of Han timber frameworks, Tibetan prayer halls, and Tu decorative elements reveals cultural convergence. Traditional craftsmanship, including carved wooden scripture blocks and tsampa-based murals, is embedded within domestic and ritual spaces. The fortress’s circulation patterns mirror Tibetan Buddhist cosmology, with mandala-like alleys and rooftop circumambulation routes. These findings offer insights into vernacular resilience and inform conservation strategies for multiethnic fortified settlements. Full article

Background: Limited data exist on the comparative diagnostic value of CT urography (CTU) versus unenhanced CT in evaluating the upper urinary tract in young adults (<50 years) with hematuria in active military service. This population may face an increased risk of urinary tract malignancies due to occupational exposures. Methods: We conducted a retrospective cohort study of 277 consecutive Israel Defense Forces personnel under 50 years old with new-onset hematuria referred for CT evaluation between 2011 and 2020. Two experienced radiologists first interpreted unenhanced CT images, followed by a review of contrast-enhanced phases. Findings were classified based on their detectability on unenhanced CT and whether contrast phases were required. Results: Of the 277 patients, 270 had microscopic hematuria and 7 had macroscopic hematuria. Imaging was normal in 158 cases. Among 119 patients (43%) with positive findings, 46 (16.6%) had clinically significant findings requiring follow-up or treatment. Of these, 42 (91%) were detectable on unenhanced CT alone. Contrast phases were requested in 15 cases (5.4%) and revealed additional benign findings. No urinary tract malignancies were identified. Conclusions: Unenhanced CT may be sufficient for evaluating new-onset hematuria in adults under 50, including active military personnel, minimizing the need for contrast administration. Full article

To address the growing threat of quantum computing to classical cryptographic primitives, this study introduces NTRU-MCF, a novel lattice-based signature scheme that integrates multidimensional lattice structures with fractional-order chaotic systems. By extending the NTRU framework to multidimensional polynomial rings, NTRU-MCF exponentially expands the private key search space, achieving a key space size $\ge 2^{256}$ for dimensions $m\ge 2$ and rendering brute-force attacks infeasible. By incorporating fractional-order chaotic masks generated via a hyperchaotic Lü system, the scheme introduces nonlinear randomness and robust resistance to physical attacks. Fractional-order chaotic masks, generated via a hyperchaotic Lü system validated through NIST SP 800-22 randomness tests, replace conventional pseudorandom number generators (PRNGs). The sensitivity to initial conditions ensures cryptographic unpredictability, while the use of a fractional-order L hyperchaotic system—instead of conventional pseudorandom number generators (PRNGs)—leverages multiple Lyapunov exponents and initial value sensitivity to embed physically unclonable properties into key generation, effectively mitigating side-channel analysis. Theoretical analysis shows that NTRU-MCF’s security reduces to the Ring Learning with Errors (RLWE) problem, offering superior quantum resistance compared to existing NTRU variants. While its computational and storage complexity suits high-security applications like military and financial systems, it is less suitable for resource-constrained devices. NTRU-MCF provides robust quantum resistance and side-channel defense, advancing PQC for classical computing environments. Full article

Post-traumatic stress disorder (PTSD) is a complex, debilitating condition prevalent among military personnel exposed to traumatic events, necessitating biomarkers for early detection and intervention. Using data from the Millennium Cohort Study, the largest and longest-running military health study initiated in 2001, our objective was to identify specific microRNA (miRNA) expression patterns associated with distinct PTSD symptom trajectories among service members and veterans and assess their potential for predicting resilience and symptom severity. We analyzed 1052 serum samples obtained from the Department of Defense Serum Repository and linked with survey data collected at baseline and across three follow-up waves (2001–2011), using miRNA sequencing and statistical modeling. Our analysis identified five PTSD trajectories—resilient, pre-existing, new-onset moderate, new-onset severe, and adaptive—and revealed significant dysregulation of three key miRNAs (miR-182-5p, miR-9-5p, miR-204-5p) in participants with PTSD compared to resilient individuals. These miRNAs, which inhibit brain-derived neurotrophic factor (BDNF) and target pathways like NFκB, Notch, and TGF-alpha, were associated with neuronal plasticity, inflammation, and tissue repair, reflecting PTSD pathophysiology. These findings suggest that miRNA profiles could serve as biomarkers for early identification of PTSD risk and resilience, guiding targeted interventions to improve long-term health outcomes for military personnel. Full article

The Great Wall of China, one of the nation’s most remarkable military defense structures, possesses a history spanning several millennia and is associated with numerous heritage sites. Today, it stands as a world-renowned cultural heritage asset. Vegetation growing on the ruins of the Great Wall can exert both detrimental and protective effects on the structure. Indiscriminate removal of such vegetation may lead to unintended damage to the heritage site. Drawing on the theory of “evaluative conservation”, this study integrates the analytic hierarchy process (AHP) and the Delphi method to develop a resistance assessment system for vegetation removal. A case study was conducted on 40 plant species or categories located along the Ming-era Guangwu section of the Great Wall, with spatial zoning analysis applied to inform removal strategies. The results reveal the structure, key factors, and classification criteria of the resistance evaluation system. Corresponding management recommendations are proposed, including strategies such as “preservation”, “partial preservation”, “removal”, and “subsequent removal and management”. This research provides a foundational reference for the conservation and restoration of the Great Wall heritage, and for the management of associated vegetation. Full article

Given the rising workloads and increased risks of burnout across various industries, enhancing employee resilience and well-being has become increasingly important. This study investigates the impact of positive leadership styles—servant, authentic, and transformational leadership—on psychological resilience and burnout levels. While prior research has examined the isolated relationships between leadership, resilience, and burnout, few studies have analyzed these variables collectively within an integrated theoretical framework. To address this gap, the present study integrates insights from the Leader–Member Exchange (LMX) theory, the Conservation of Resources (COR) theory, and the Job Demands–Resources (JD-R) model to provide a comprehensive perspective. Data were collected from 387 private school teachers in Turkiye. Statistical analyses were conducted using PROCESS Macro (Model 4), assessing both direct and mediating effects. The findings reveal that all three leadership styles enhance psychological resilience and mitigate burnout. Furthermore, psychological resilience partially mediates the relationship between positive leadership styles and burnout. These results contribute to the literature by demonstrating how positive leadership can buffer against burnout through resilience, emphasizing the need for context-specific research in the field. This study also offers practical implications for managers seeking to foster supportive work environments. Full article

Exposure to severe combat situations significantly raises the risk of depression and post-traumatic stress disorder (PTSD). Trauma survivors may use dissociation as a defense mechanism, increasing the likelihood of PTSD. This study aims to explore the roles of dissociation and depression in PTSD among soldiers exposed to combat who sought help from the Israel Combat Stress Reaction Unit. Method: This cross-sectional study involved 927 individuals who participated in a particular military operation in 2014 [98.5% male (n = 906); mean age = 27.08 (SD = 5.93)]. Participants completed three questionnaires: the Dissociative Experiences Scale (DES), the Beck Depression Inventory (BDI), and the Post-Traumatic Stress Symptom Checklist (PCL-5) for PTSD. Results: Our results showed that severe PTSD (PCL score ≥ 33) was found in 30.4% of participants, and 76.6% showed dissociative symptoms (DES score ≥ 30). Additionally, 23.5% experienced moderate depression, while 19.1% reported severe depressive symptoms. A Generalized Linear Model revealed that both depression and dissociation significantly contribute to PTSD. Individuals with depression were three times more likely to experience post-traumatic symptoms compared to 1.23 times for those with dissociative symptoms. Conclusions: Life-threatening situations significantly predicted higher PTSD symptoms, serving as a risk factor for depression and dissociation, which play important roles in PTSD, with depression having notably greater impact. Full article

In today’s high-stakes arenas—from healthcare to defense—algorithms are advancing at an unprecedented pace, yet they still lack a crucial element of human decision-making: an instinctive caution that helps prevent harm. Inspired by both the protective reflexes seen in military robotics and the human amygdala’s role in threat detection, we introduce a novel idea: an integrated module that acts as an internal “caution system”. This module does not experience emotion in the human sense; rather, it serves as an embedded safeguard that continuously assesses uncertainty and triggers protective measures whenever potential dangers arise. Our proposed framework combines several established techniques. It uses Bayesian methods to continuously estimate the likelihood of adverse outcomes, applies reinforcement learning strategies with penalties for choices that might lead to harmful results, and incorporates layers of human oversight to review decisions when needed. The result is a system that mirrors the prudence and measured judgment of experienced clinicians—hesitating and recalibrating its actions when the data are ambiguous, much like a doctor would rely on both intuition and expertise to prevent errors. We call on computer scientists, healthcare professionals, and policymakers to collaborate in refining and testing this approach. Through joint research, pilot projects, and robust regulatory guidelines, we aim to ensure that advanced computational systems can combine speed and precision with an inherent predisposition toward protecting human life. Ultimately, by embedding this cautionary module, the framework is expected to significantly reduce AI-induced risks and enhance patient safety and trust in medical AI systems. It seems inevitable for future superintelligent AI systems in medicine to possess emotion-like processes. Full article

Postharvest Flammulina filiformis is prone to quality degradation, adversely impacting its commercial value. Cordyceps militaris, rich in antioxidant and antibacterial components, shows promise as a natural biological preservative. This study aimed to explore the potential of C. militaris extract (CME) as a preservative for F. filiformis. Through analyzing indicators such as browning, stipe elongation, and cap diameter, this study confirmed the effectiveness of CME in delaying oxidation and inhibiting microbial growth during storage. Additionally, transcriptome analysis revealed that CME modulated gene expression in F. filiformis, enhancing its antioxidant defense mechanisms. The results demonstrated that CME could effectively extend the shelf life of F. filiformis, providing valuable insights into preservation strategies for this and other edible fungi. Full article

Titanium alloy has been widely used in aerospace, military, and national defense, and other high-tech fields due to its advantages of light weight, high specific strength, excellent corrosion resistance, excellent heat resistance, and good low-temperature performance. In the turning of titanium alloys, a significant quantity of continuous chips with poor breakability is generated. Recycling these titanium chips can effectively reduce raw material costs and minimize environmental impacts, as it decreases the dependency on primary titanium sources. The titanium chip crushing process is an indispensable part of the titanium chip recovery process, and the double-teeth roll crushing process is the most commonly used metal crushing process. Finite element simulation is an efficient, time-saving, and resource-saving method to optimize the titanium chip crushing process. In this paper, the stress change in the process of titanium chip crushing is analyzed by finite element simulation, and the influence of the number of cutter roller teeth and the speed of the cutter roller on the crushing effect of the titanium chip is analyzed. The optimal process parameters of the titanium chip crusher were obtained by response surface optimization, and the accuracy of the finite element simulation was verified by experiments, which provided a theoretical and practical basis for optimizing the titanium chip crushing process. Full article

As a crucial component in the evolution of modern warfare toward digitization and intelligentization, unmanned aerial vehicle (UAV) equipment requires a more precise and efficient operation and maintenance (O&M) system. Based on the Department of Defense Architecture Framework (DoDAF) 2.0, the integration of Multi-Agent Systems (MAS) and military simulation technology provides a comprehensive, rational, and feasible theoretical foundation for the construction and validation of an intelligent O&M system for UAV equipment. Firstly, starting from the O&M tasks of UAV equipment in intelligent warfare, this study analyzes the capability requirements for intelligent UAV O&M by following the generation path of scenarios, activities, and capabilities. Three core capabilities are proposed: situational awareness, decision support, and mission execution. Secondly, various O&M tasks are decomposed into behaviors of multiple types of agents, and based on this, an intelligent O&M system for UAV equipment is designed using a “cloud-edge-terminal” distributed architecture. Finally, simulations are conducted to model and validate UAV equipment maintenance tasks. Experimental results demonstrate that the MAS-based UAV O&M system significantly enhances support efficiency, accuracy, and response speed, offering a novel solution for O&M in future UAV operations. Full article