Browse Articles

Finite element analysis of warpage and debonding behavior in RDL-first and molding-first fan-out panel-level packaging

Abstract This study investigates the applicability of various carrier materials in fan-out panel-level packaging (FOPLP) processes through finite element analysis (FEA). Numerical simulations were performed for RDL-first and molding-first process flows to evaluate warpage and stress distribution across different carrier types, including steel, glass, and ceramic. Two panel dimensions, 600 $$\:\times\:$$ 700 mm and 680 $$\:\times\:$$ 680 mm, were modeled under varying manufacturing processes, temperature settings, and material properties. The simulations incorporated both mechanical and chemical shrinkage effects, with the molding-first process modeled from compression molding to the debonding stage. The element birth and death technique was implemented to account for material addition and removal during processing, thereby enhancing simulation accuracy. The results indicate that the average reference temperature provides the lowest prediction error in the RDL-first process, while maximum von Mises stress consistently occurs in the RM 1 and WAL layers. Furthermore, a significant increase in warpage is observed during the debonding stage in the molding-first process. A comparative analysis between simulation and experimental results demonstrates a high level of agreement, confirming the validity and reliability of the modeling approach. By systematically examining the thermo-mechanical behavior of multiple carrier materials in different process flows, this work establishes a comprehensive design guideline for carrier selection and process optimization in advanced FOPLP manufacturing.

A scoping review of computational models of the diabetic foot

The prevalence of diabetes is expected to be 650 million people by 2030, and diabetic foot ulceration (DFU) is one of its most severe complications. It poses a significant challenge to global health and brings substantial social and economic burdens. Although many studies have explored the mechanisms of DFU development, they are still not fully understood. Due to the high cost of the experimental research, many recent studies have employed the computational modelling approaches to simulate the effects of diabetes on foot tissues from mechanical, thermal, fluid, and cellular perspectives. This study aims to provide a comprehensive review of computational modelling approaches used to investigate various factors influencing DFU, discuss current knowledge gaps and limitations, and outline future research directions. A systematic search was conducted in Web of Science, Scopus, and PubMed databases, identifying a total of N = 1631 records up to March 2025, 31 of which studies met the inclusion criteria and were analysed in this study. Results showed that DFU-related computational models can be categorized into five types: mechanical stress models, thermal models, vascular and nerve system models, multiphysics models, and cellular-based models. These models explore the formation mechanisms of DFU from different perspectives, including biomechanics, temperature, fluid dynamics, HHμm neural signalling, and cellular responses. However, except for mechanical stress models, the other approaches remain in the early stages of development, and the single physics modelling strategies are unable to provide understanding on the coupled processes with the foot and their effect on DFU. Future research should further develop modelling approaches and couple these together to develop comprehensive understanding of DFU pathogenesis.

Anisotropic quantum confinement in interface-defined stanene quantum dots

Quantum dots (QDs) embedded in two-dimensional (2D) materials provide an ideal platform for exploring tunable quantum confinement in real and momentum space. Here, we investigate interface-defined stanene QDs by low-temperature scanning tunneling microscopy and spectroscopy. The QDs form as nanometer-scale confined regions within a continuous stanene monolayer due to buried interfacial SnxO nanopatches. Differential conductance spectra reveal discrete resonant states accompanied by pronounced quantum interference patterns. Spectroscopic mapping along orthogonal crystallographic directions shows strong anisotropy of the confined states, indicating quasi-one-dimensional confinement. The observed energy levels are well described by an effective one-dimensional hard-wall model with a spatially varying potential. These results establish interface-controlled quantum confinement in stanene and demonstrate how buried interfacial structures can fundamentally reshape electronic states in supported 2D Xene materials.

Enhancing complaint locations prediction with image-space embedding representations and customized large language models

Speed, slope, and synchrony: Empirical insights into SAR searcher behavior

Wilderness search and rescue (SAR) missions are time-critical and terrain-dependent, so planners must quickly allocate resources across complex landscapes. In practice, they rely on expert judgment and experience-based assumptions to coordinate individuals and teams, yet few of these assumptions have been formally validated with field data and modeling. We address this gap by analyzing GPS tracks from 64 SAR incidents, selecting 61 tracks from 13 cases. The tracks are categorized by search tactic: hasty, sweep, or team sweep, with the last divided into six teams of varying size. To quantify how tactic and terrain shape movement, we bootstrapped exponential speed-slope fits, ran Kolmogorov-Smirnov tests, and used a nested ANOVA with random effects. Median uphill and downhill speeds are statistically indistinguishable (0.48 m/s vs. 0.52 m/s; KS p  = 0.093), suggesting that slope penalties on pedestrian speed can be modeled symmetrically. Hasty searches are faster than sweeps (0.53 m/s vs. 0.39 m/s; KS p  < 10 −3 ), with no interaction between slope and tactic. Team-level analyses using Spearman correlation, time-lagged cross-correlation, and transfer entropy revealed tightly coupled movement and identifiable leaders, with follower reaction lags of only a few seconds. These empirically derived parameters–search-type specific baseline speeds, a single slope coefficient, and realistic coordination bounds–offer practical inputs for SAR coverage calculations and agent-based models. Incorporating values drawn from real field data could refine human mobility assumptions while remaining compatible with the existing SAR operational framework.

Ultrasensitive acoustic sensing and optical comb generation in a hybrid optomechanical system

Cavity optomechanical systems have emerged as a powerful platform for high-sensitivity acoustic sensing. However, their sensitivities at kilohertz frequencies are typically limited due to the inherent challenge in simultaneous optimization of optical and mechanical modes within a single resonator. In this work, we demonstrate a hybrid optomechanical system consisting of a tapered microfiber evanescently coupled with a microtoroid cavity. The microfiber supporting multiple kilohertz-frequency mechanical modes acts as a sensitive acoustic transducer, while the microtoroid serves as a sensitive readout cavity. Utilizing the strong acousto-optic interaction, the system enables thermal noise-limited ultrasensitive acoustic sensing in the kilohertz-frequency range, achieving an optimal noise equivalent pressure of 0.72 μPa/Hz1/2 at 19.85 kHz. Furthermore, under strong acoustic driving, the system enables generation of optical frequency combs, with over 100 comb lines and tunable repetition rates across the kilohertz range by exciting different mechanical modes of the microfiber. This hybrid optomechanical system offers significant potential for applications in trace gas photoacoustic sensing, bioacoustic monitoring, and high-resolution spectroscopy.

A nationwide survey of medical resource usage for cancer treatment using Japanese health claims data from 2011 to 2022

Abstract Multidisciplinary cancer treatments have advanced significantly, especially with molecular targeted therapies improving prognosis. Although these are expensive, their cost impact remains unverified. This study aimed to investigate the overall utilization of healthcare resources and identify the cost drivers of cancer treatment in Japan. In this retrospective cohort study, patients diagnosed with malignancies between April 2011 and March 2022 were classified by cancer type, and monthly insurance claims and applicable medications were analyzed. Breast cancer was the most common, followed by stomach and colon cancers. Cost analysis by cancer type revealed that lung cancer was the most expensive overall, whereas multiple myeloma was the most expensive per person-month. When antineoplastic drug costs were aggregated by mechanism, a rapid increase was observed in the immune checkpoint inhibitor category. Since the advent of immune checkpoint inhibitors, the number of insurance claims for antineoplastic drugs in Japan has increased. Japan’s public healthcare system has seen an increase in the cost of cancer treatment at a rate exceeding national economic growth. These findings highlight the need for policies that address the cost-effectiveness and sustainability of cancer care to ensure continued access to high-quality treatment within publicly funded systems in Japan and globally.

Controllable nonlocality of acoustic meta-surfaces based on Willis coupling

Significant nonlocality is the principal mechanism enabling superior and versatile functionalities of non-local meta-surfaces with efficiency that goes far beyond conventional designs. Distinct from the design strategy of minimizing the non-local coupling effects in acoustic phase-gradient meta-surfaces, nonlocality has been explored to achieve anomalous wave manipulations with extremely high efficiency. However, the controllable exploitation of non-local coupling effects to intentionally tailor acoustic behavior remains a challenge. Therefore, we proposed a theoretical model for predicting the acoustic performance of finite meta-surfaces using Willis coupling as an additional degree of freedom, in which a coupling index βn is derived to explicitly characterize and leverage the non-local coupling effects. Numerical calculations performed on a random three-meta-atom array confirmed the accuracy of our model and demonstrated the dominant influence of non-local coupling effects on both the scattering strength and directivity of the constituent meta-atoms. Furthermore, the controllability of non-local coupling effects via the derived βn was demonstrated in two sound-isolation meta-surfaces, where the acoustic responses of all meta-atoms were modulated and synchronized, achieving a significant enhancement in transmission loss. This work novelly elevates non-local coupling effects from an inherent phenomenon to a controllable parameter based on Willis coupling for the practical design of high-efficiency non-local meta-surfaces.

Multimodal fusion-based prediction of postoperative survival in gallbladder adenocarcinoma: Model development and validation

Experimental quantum Bernoulli factories via Bell-basis measurements

Randomness processing in the Bernoulli factory framework provides a concrete setting in which quantum resources can outperform classical ones. We experimentally demonstrate quantum randomness processing based on Bell-basis measurements of two identical input quoins prepared on IBM superconducting hardware. Using only the measurement outcomes (and no external classical randomness source), we realize the classically inconstructible Bernoulli doubling primitive f(p)=2p, and, as intermediate outputs from the same Bell-measurement statistics, an exact fair coin f(p)=1/2 and the classically inconstructible function f(p)=4p(1−p). We benchmark the measured output biases against ideal predictions and discuss the impact of device noise. Our results establish a simple resource-efficient experimental primitive for quantum-to-classical randomness processing and support the viability of quantum Bernoulli factories for quantum-enhanced stochastic simulation and sampling tasks.

Myco-barrier: edge-orchestrated post-detection mitigation of IoT botnets via an SDN-based virtual dynamic demilitarized zone

Squeezed-light-controlled magnon–photon pair antibunching in a cavity optomagnonic system

We investigate magnon–photon pair antibunching in a cavity optomagnonic system, in which a yttrium iron garnet sphere simultaneously supports two optical modes and a magnon mode and is driven by squeezed light and coherent light. The results illustrate that by applying squeezed light, the conventional magnon–photon pair blockade (CMPPB) originating from anharmonic energy levels and the unconventional magnon–photon pair blockade (UMPPB) induced by destructive quantum interference can coexist in the same platform. Both blockade effects can be flexibly tuned by the driving detuning and the optomagnonic coupling strength. Within the explored parameter regime, the UMPPB exhibits a nontrivial dependence on the driving strengths of coherent light and squeezed light, and bunching regions may also appear. These results provide a tunable framework for controlling magnon–photon pair antibunching, which may be useful for the generation and manipulation of hybrid nonclassical states in cavity optomagnonic systems.

Reservoir computing-based cryptanalysis of structured phase-masked chaos encryption

Interfacial built-in electric field engineering in MnO2/MXene heterostructures for high-performance aqueous ammonium-ion hybrid supercapacitors

Aqueous ammonium-ion hybrid supercapacitors (AAHSCs) have attracted increasing interest owing to their environmental friendliness, low cost, and fast charge/discharge capability. However, the practical application of MXene electrodes is limited by their intrinsic self-stacking behavior, which hinders ion transport and electrochemical utilization. Herein, MnO2 nanosheets were in situ grown on MXene to construct a MnO2/MXene heterostructure with an interfacial built-in electric field (BIEF). The heterointerface effectively suppresses MXene restacking while providing abundant electrochemically active sites for NH4+ storage. Meanwhile, the BIEF induced by the Fermi-level (EF) difference between MnO2 and MXene accelerates charge transfer and facilitates ion diffusion. Benefiting from the synergistic effects of pseudocapacitive Mn2+/Mn4+ redox reactions, hydrogen-bond interactions between NH4+ and oxygen-containing groups, and BIEF-assisted charge transport, the MnO2/MXene electrode delivers a high specific capacitance of 725.5 F g−1 at 1 A g−1. The assembled AAHSC device achieves an energy density of 99.7 Wh kg−1 at 900.7 W kg−1, with 75.9% capacitance retention after 10 000 cycles. This work provides an effective interfacial engineering strategy for developing high-performance ammonium-ion energy storage systems.

Association between ABO blood groups and clinical manifestations and outcomes of COVID-19: a retrospective cross-sectional study in southeast Iran

Hard carbon nanospheres derived from copper-ion-mediated crystalline topological regulation for efficient sodium-ion storage

Modulating graphite lattices in hard carbons derived from artificial organic polymer precursors is critical to achieve highly consistent anode materials for efficient sodium-ion storage. Herein, hard carbon nanospheres with highly disordered and twisted graphite-like lattices were developed by pyrolyzing a Cu-coordinated polymer with bisimide–pyridine ligands as a precursor. Results demonstrate that incorporating Cu ion in the precursor not only effectively alters the morphology of the correspondingly obtained carbons from bulk to nanospheres, but also enables the transformation from ordered graphite lattices to a disordered structure, resulting in significantly improved sodium storage. The optimized hard carbons feature uniform nanospheres with an expanded interlayer spacing (0.386 nm) and limited graphitic stacking (∼3 layers), exhibiting a high reversible capacity of 365.64 mAh g−1 with a remarkable plateau capacity of 208.96 mAh g−1 (< 0.1 V), along with a high rate performance (215.58 mAh g−1 at 5 A g−1) and cycling stability for up to 5000 cycles, outperforming the carbon obtained without Cu2+ and a majority of previously reported hard carbons derived from artificial polymers. Moreover, theoretical calculations reveal that the appropriate interlayer spacing and graphite stacking layers are crucial for efficient Na+ storage. This Cu-induced hard carbon nanosphere from an artificial precursor provides a new route for modulating the graphite lattices of hard carbons for efficient sodium-ion storage.

Directional motion of a self-steering active intruder in a dense crowd of cognitive active agents

Abstract The fast and efficient directed motion of particles through crowded environments is challenging problem. In this work, the surface-bound motion of an intruder in a crowd of identical active agents is studied by overdamped Langevin dynamics simulations. Both intruder and agents are modeled as intelligent active Brownian particles (iABPs) with visual perception and directional steering to avoid collisions - which implies non-reciprocal interactions between all particles. The reorientation of intruder and agents is limited by their maximal maneuverability, which controls the ability of an iABP to adjust its velocity direction. The simulation results show that the intruder’s attempt to increase directional speed by steering around agents fails; in fact, this even reduces the directional speed. In contrast, the intruder has to be perceived by the agents so that they can move out of the way in time. The intruder speed and transverse diffusivity are determined as functions of several key control parameters, like maneuverability, vision angle, and agent density. Here, an important parameter is the uniformity of the agent distribution. It is shown that the agent’s self-steering to avoid collision enhances hyperuniformity (class III), which facilitates an easier directional navigation of the intruder. Results are relevant, inter alia, for the motion of emergency personnel in semi-dense human crowds.

A visibly clear radiative cooling film with high sub-bandgap reflectance for enhancing solar cell performance

The performance of solar cells (SCs), including the photoelectric conversion efficiency and lifespan, significantly degrades with increasing operating temperature. Spectral-selective radiators with high visible transparency and strong infrared thermal emission offer a practical way to reduce temperatures and enhance SC performance. However, conventional radiators for SCs generally exhibit high transmittance across the entire solar spectrum (0.38–4.0 μm), thereby failing to reflect sub-bandgap (1.1–4.0 μm) irradiance, which can lead to parasitic heating. Herein, we propose a tri-band modulated film (TMF) that is visibly clear, highly reflective under sub-bandgap irradiation, and exhibits strong radiative cooling, thereby enhancing the performance of SCs. The proposed TMF exhibits 90.1% transmittance in the 0.38–1.1 μm range, 81.3% reflectivity the in 1.1–4.0 μm range, and an emissivity of 0.95 in the 6–20 μm range, enabling reduced temperatures and enhanced SC performance. Theoretical analysis and numerical modelling results demonstrate that, compared to glass encapsulation, the TMF reduces the SC operating temperature by 6.13 K and improves the relative photoelectric conversion efficiency by 2.40%, while maintaining stable performance across a wide range of incident angles of solar irradiation. Under practical weather conditions, the TMF reduces the bare-cell temperature by 15.22 K, accompanied by a 4.55% increase in power output. The current TMF provides a highly efficient spectral engineering-based thermal management strategy to enhance SC performance.

Smart grid integration by optimizing energy, carbon, and production in industrial systems with contextual reinforcement learning

Extrinsic origin of nonreciprocal resistance in a non-chiral organic superconductor

We investigate nonreciprocal conductivity in the superconducting state of the molecular conductor κ-(BEDT-TTF)2Cu[N(CN)2]Cl. Although the material is neither chiral nor polar, we have observed nonreciprocal resistance proportional to the applied current and in-plane magnetic field, which is comparable with that of gate-induced superconducting MoS2. However, we find that this nonreciprocal resistance exhibits significant sample dependence, with even its sign varying. Furthermore, within the same sample, its magnitude and sign varied depending on the measurement location, suggesting the existence of nonreciprocal resistance governed by a mechanism distinct from the Rashba effect in polar superconductors. The increase in nonreciprocal resistance due to current terminals with high contact resistance suggests the Nernst effect, arising from slight temperature gradients along the out-of-plane direction, as its origin. Utilizing this, we successfully increased the nonreciprocal coefficient by up to approximately twofold by processing the sample into a nonuniform shape.