Florida Institute of Technology

Uncontrolled tipping during incisor retraction with clear aligners continues to limit orthodontic treatment. Different countermeasures have been proposed to improve the predictability of aligners, such as power ridges and attachments, while their efficacy requires further investigation. This work investigated the biomechanics of the overcorrection in reducing the tipping angle and moment during incisor retraction with a clear aligner, through in vitro experiments and finite element analysis (FEA). Specifically, the influence of overcorrection angle (1 deg), retraction distance (0.15 mm), and the combination of both were assessed through in vitro experiments and the finite element simulation. Further computational simulations were conducted to inspect the mechanical performance of clear aligners with different overcorrection angles (from 0 deg to 1 deg and 2 deg) for a fixed retraction distance of 0.15 mm. As the overcorrection angle increased from 0 deg to 1 deg and 2 deg for the clear aligner with a retraction of 0.15 mm, the tipping angle of the incisor decreased from 0.29 deg to 0.25 deg and 0.21 deg, and the tipping moment at the tooth root decreased from 13.60 N·mm to 9.38 N·mm and 6.27 N·mm. However, the retraction force also decreased from 0.84 N to 0.73 N and 0.47 N, indicating a tradeoff between tipping control and retraction efficiency, likely due to increased counteractive moment and the decreased force exerted by the aligner on the tooth crown. In conclusion, this study presents both the benefits and limitations of overcorrection strategies in reducing the tipping angle and moment during incisor retraction using clear aligners, providing biomechanical insight for the optimal design of clear aligners for improving treatment outcomes.

Weld root reinforcement is a critical geometric parameter governing stress concentration and structural performance in thin-walled stainless-steel piping systems designed to ASME B31.3. While current codes specify permissible dimensional limits, they do not explicitly quantify how incremental variations in root height influence stress distribution under realistic service loading conditions. This study integrates finite element analysis (FEA) with experimentally validated GTAW weld profiles to evaluate the structural influence of weld root height in 316L stainless-steel pipe joints. An experimentally manufactured 4 in schedule 10S joint with a measured root height of less than 1.5 mm was adopted as the baseline geometry. Additional models with reinforcement heights of 1.138, 2.0, 2.5, and 3.0 mm were evaluated under two representative load cases: (i) internal pressure combined with drag and axial thrust (LC-1), and (ii) internal pressure with thrust only (LC-2). The results demonstrate that reinforcement heights exceeding 2.0 mm increase von Mises, hoop, longitudinal, and radial stress gradients, with peak stresses shifting toward the weld toe under drag-inclusive loading. In contrast, reinforcement ≤2 mm provides smoother load transfer and reduced stiffness discontinuity across the weld interface. The combined numerical and experimental findings support a stress-informed upper limit of 2 mm for weld root reinforcement in thin-walled stainless-steel pipelines, offering a performance-based complement to existing dimensional acceptance criteria.

The reliability of cyber forensic evidence acquisition is strongly influenced by the underlying operating systems, Windows, macOS, and Linux - due to inherent variations in file system structures, encryption protocols, and forensic tool compatibility. Disk forensics, one of the most widely used techniques in digital investigations, faces distinct obstacles on each platform. Windows, with its predominantly NTFS and FAT file systems, typically supports reliable disk imaging and analysis through established tools such as FTK Imager and Autopsy/Sleuth Kit. However, encryption features frequently pose challenges to evidence acquisition. Conversely, Linux environments, which rely on file systems like ext4 and XFS, generally offer greater transparency, yet the transient nature of log retention often complicates forensic analysis. In instances where anti-forensic strategies—such as encryption and compression— render traditional disk forensics insufficient, memory forensics becomes crucial. While memory forensic methodologies demonstrate robustness across Windows and Linux platforms forms through frameworks like Volatility, platform-specific difficulties persist. Memory analysis on Linux systems benefits from tools like LiME, snapshot utilities, and dd for memory acquisition; nevertheless, live memory acquisition on Linux can still present challenges. This research systematically assesses both disk and memory forensic acquisition techniques across samples representing Windows and Linux systems. By identifying effective combinations of forensic tools and configurations tailored to each operating system, the study aims to improve the accuracy and reliability of evidence collection. It further evaluates current forensic tools and highlights a persistent gap: consistently assuring forensic input reliability and footprint integrity. By integrating static analysis with temporal performance evaluations, this study emphasizes the importance of developing standardized forensic procedures to ensure the integrity and admissibility of evidence across diverse platforms. Establishing such standardized methodologies is imperative to maintaining the credibility and reliability of cyber forensic investigations in heterogeneous operating system environments.

Abstract In this paper, we investigate the population of energetically dominant sunward-propagating Alfvén waves (SAWs) using more than 20 yr of data provided by the Wind spacecraft near 1 au. We refer to SAWs as energetically dominant sunward-propagating Alfvén waves within inertial range scales. Key parameters such as normalized cross helicity, plasma compressibility, and magnetic compressibility are used to determine the SAWs. Incorporating the polarity of the heliospheric magnetic field, Alfvén wave modes are identified, which enables the determination of the propagation direction. Occurrence rates of SAWs vary from 1% to 14% depending on the timescale and solar wind stream type considered. Particularly, the relationship between large-scale magnetic field switchbacks and SAWs (for a 1 hr long timescale) is investigated. A methodology utilizing pitch angle distributions of suprathermal electron strahl is employed to identify inverted magnetic field topology. The intervals containing SAWs are cross-referenced and examined with intervals identified as switchbacks . For a sample of 1636 1 hr SAW intervals, 17.5% are associated with magnetic field switchbacks occurring at scales larger than 1 hr. The analysis lends support to the idea of switchbacks as one of the candidate sources for a portion of the SAW population.

Autonomous UAV swarms are increasingly deployed for time-sensitive missions where secure communication and strict real-time control must coexist. The transition to post-quantum cryptography (PQC) introduces substantial computational overhead that can push cryptographic operations beyond coordination deadlines if algorithms are fixed a priori. This challenge is compounded by dynamic operational requirements: reconnaissance missions prioritize efficiency while tactical operations demand higher security, which static cryptographic configurations cannot accommodate. We evaluate cryptographic agility, defined as adapting algorithms to operational context, using a simulator grounded in empirical cycle counts for ARM Cortex-M4 processors. Through extensive simulation, agile configurations maintain high deadline compliance rates while static policies experience significant degradation under operational stress. Because no single NIST-approved PQC scheme jointly optimizes security, latency, and energy across varying mission requirements, these results provide evidence that adaptive selection is necessary to address performance bottlenecks in post-quantum UAV swarms. We also discuss design implications and outline how agility can be integrated with real-time coordination and provisioning workflows.

Characterization of uncooperative Resident Space Objects (RSOs) plays a crucial role in On-Orbit Servicing (OOS) and Active Debris Removal (ADR), allowing missions to assess the geometry and motion properties of the target. Addressing the specific challenge of reconstructing tumbling targets, this study evaluates the performance of existing state-of-the-art 3D reconstruction algorithms for dynamic scenes (D-NeRF, TiNeuVox, HexPlane), focusing on their ability to generate physically plausible representations with high fidelity. Specifically, we address a scene that is both geometrically dynamic, due to the tumbling target, and subject to dynamic lighting, where directional sunlight casts shifting shadows across the surface. To support our evaluation, we developed a simulation environment using Isaac Sim to generate physics-accurate 2D image sequences of tumbling satellites under high-fidelity orbital lighting conditions. We observe that while HexPlane excels in stationary scenarios (PSNR > 35 dB), all methods degrade substantially as complexity increases. In fly-around scenarios, D-NeRF produces blurred outputs, HexPlane exhibits ghosting artifacts, and TiNeuVox introduces foggy artifacts. Moreover, standard metrics fail to capture these structural inconsistencies due to the dominance of the black background in the images.