Search Results (2,028)

Integrated Sensing and Communication (ISAC) has emerged as a key enabling technology for future sixth-generation (6G) wireless networks by enabling sensing and communication functionalities to share spectrum, hardware resources, and signal processing infrastructure. However, practical ISAC systems are affected by self-interference, mutual interference between sensing and communication signals, and environmental clutter, which jointly degrade communication reliability and sensing performance. To address these challenges, this paper proposes a novel three-slot interference mitigation framework for downlink ISAC systems. Unlike conventional ISAC approaches that perform joint sensing and communication within a single transmission stage, the proposed framework separates directional sensing, parameter acquisition, and interference-aware joint transmission into three coordinated slots, enabling transmit-side pre-cancellation of sensing-induced mutual interference using estimated interference parameters. Furthermore, joint convex optimization-based beamforming is employed to mitigate self-interference through sidelobe minimization and suppress environmental clutter through spatial null steering while maintaining the desired sensing and communication links. Simulation results demonstrate beam steering, parameter recovery, communication performance after interference cancellation, and target range, velocity, and angle estimation using Range-Doppler and Multiple Signal Classification (MUSIC) processing. The proposed framework presents an interference-aware ISAC architecture that combines a three-slot transmission protocol for mitigating sensing-induced mutual interference with joint beamforming for suppressing self-interference and environmental clutter while supporting simultaneous sensing and communication. Full article

To address the difficulty of extracting weak fault features of rolling bearings in wind turbines under strong background noise, a fault feature extraction method based on the collaborative filtering correlation spectrum, named CESIgram, is proposed. The collaborative filtering correlation spectrum (CFCS) based on Block Matching 3D is designed to suppress random noise while preserving cyclostationary structures, resulting in a clearer cyclic spectral representation. A projection method along the cyclic frequency axis is proposed to obtain the carrier-based enhanced envelope spectrum. An integrated envelope spectrum index combining harmonic significance and periodic impact is proposed to quantify fault feature enrichment in different enhanced envelope spectra. The method works in three stages: spectral representation via Fast-SC, reformulation of the spectral correlation via CFCS, and adaptive band selection via CESI. The method successfully extracted fault characteristic frequencies and their harmonics in simulation and experimental signals under various strong noise conditions, while Fast Kurtogram, Autogram, Infogram, and Fast Entrogram failed to detect any fault-related peaks. Comparative analysis shows that the proposed method has significant advantages in noise suppression and fault feature extraction. The effectiveness is verified using simulation and experimental signals of rolling bearing faults in wind power equipment. Full article

To address the critical thermal challenges in high-performance computing and three-dimensional integrated circuits, the doping-tunable control of near-field thermal radiation using CMOS-compatible materials offers a highly promising non-contact cooling strategy. In this work, radiative heat transfer between two parallel heavily phosphorus-doped silicon plates separated by a vacuum gap is studied using fluctuational electrodynamics. A doping-dependent Drude model is employed to describe the dielectric response of doped silicon, including carrier concentration, ionization, and mobility effects. The influences of gap width and doping concentration on the total and spectral heat transfer are systematically analyzed. The results show that the heat transfer increases sharply as the gap decreases and is mainly governed by TM-polarized evanescent modes. Under symmetric doping, the spectral peak shifts to higher frequencies as the doping concentration increases from ${10}^{18}$ to ${10}^{21} {\mathrm{cm}}^{-3}$, while the strongest transfer occurs at ${10}^{19} {\mathrm{cm}}^{-3}$ because of favorable surface-plasmon-polariton coupling and impedance matching. These findings provide a theoretical foundation for chip-scale thermal management and on-chip radiative cooling in CMOS-compatible silicon platforms, although practical implementation would require dynamic tuning mechanisms and device-level engineering in future work. Full article

The aim of this study was to determine the association between matrix metalloproteinase (MMP1, MMP2, and MMP3) gene variations and susceptibility to Peyronie’s disease, and to investigate their effects on disease progression. This cross-sectional case–control study included a total of 182 individuals—91 patients with Peyronie’s disease and 91 healthy controls. Peripheral venous blood samples (5 mL) were collected, and genomic DNA was isolated using standard spin-column extraction kits. The promoter regions of MMP1, MMP2, and MMP3 were amplified via polymerase chain reaction (PCR), and genotyping was performed using restriction fragment length polymorphism (RFLP) assays with specific restriction endonucleases. All genotyping procedures were conducted in a blinded fashion. Hardy–Weinberg equilibrium analysis (HWE), binary logistic regression with rigorous multiplicity adjustments (Bonferroni-adjusted p-values), and non-parametric Kruskal–Wallis/Mann–Whitney tests with Dunn–Bonferroni post hoc comparisons were utilized. The frequency of the 2G allele for MMP1 (−1607 1G/2G) was significantly higher in the patient group (0.4830) compared to the control group (0.2360; p < 0.05). Similarly, significant differences in allele frequencies were observed for MMP2 (−735 C/T) and MMP3 (−1171 5A/6A) between the cohorts (p < 0.05). HWE analysis confirmed that all investigated variations were in equilibrium in both groups (all p > 0.05). Logistic regression analysis showed that the MMP1 1G/1G genotype was associated with lower odds of Peyronie’s disease (OR: 0.250, p < 0.001), while the 1G/2G (OR: 2.032, p = 0.023) and 2G/2G (OR: 3.509, p = 0.005) genotypes were significantly associated with increased odds. Temporally, carriers of the MMP1 2G/2G genotype presented predominantly in the acute phase, exhibiting a significantly shorter median symptom duration (6.00 months, IQR: 3.00–9.00) compared to 1G/1G carriers (12.00 months, IQR: 5.25–36.00; p = 0.016, adj p = 0.048). For MMP2 (−735 C/T), the CC genotype was associated with higher odds of Peyronie’s disease (OR: 3.049, p < 0.001), while the TT genotype was associated with lower odds (OR: 0.278, p = 0.002). Furthermore, penile plaques were detected in 90% of patients with the CC genotype (p < 0.001). Patients with the CC genotype presented with a median symptom duration of 6.00 months (IQR: 3.00–12.00), whereas TT carriers exhibited a significantly longer duration (24.00 months, IQR: 4.00–48.00; p = 0.002, adj p = 0.006). Regarding MMP3 (−1171 5A/6A), the 5A/5A (OR: 3.930, p = 0.002) and 5A/6A (OR: 2.050, p = 0.022) genotypes were significantly associated with increased odds of the disease, while the 6A/6A genotype showed an inverse association (OR: 0.226, p < 0.001). Patients carrying the 5A allele presented characteristically in the acute phase, with a median symptom duration of 6.00 months (5A/5A) or 4.00 months (5A/6A), which was significantly extended to a median of 24.00 months (IQR: 7.50–54.00) in the 6A/6A genotype (p < 0.001, adj p < 0.001). The findings indicate robust statistical associations between the MMP1 2G, MMP2 C, and MMP3 5A alleles and increased susceptibility to Peyronie’s disease, as well as distinct correlations with compressed symptom durations, acute-phase characteristics, and plaque presence. Because this study relied on peripheral blood DNA genotyping without direct tissue expression quantification in a cross-sectional design, these genetic variations reflect strong exploratory associations rather than direct causal evidence. These markers highlight significant prognostic potential that warrants validation in larger, prospective, longitudinal cohorts. Full article

Future low Earth orbit (LEO) communication constellations are evolving into integrated multi-mission infrastructure. Their signals of opportunity (SoP) are therefore becoming attractive for Doppler positioning. However, the conventional coverage- or rate-optimized configurations may not provide favorable Doppler geometry under realistic link-quality constraints. This paper considers this emerging requirement at the constellation-configuration design level and proposes a multi-layer Walker optimization framework for integrated communication and SoP Doppler positioning. A system-level positioning metric is developed to move beyond visibility and dilution-of-precision indicators. A link-quality-constrained multi-epoch Fisher information matrix (FIM) incorporates $C/N_0$-based link measurability and a general carrier-to-noise-density-dependent Doppler-noise formulation. In the reported simulations, $C/N_0$ controls observation admission, while all admitted Doppler observations use a fixed noise standard deviation of 0.5 m/s. An effective position-error bound is then obtained by marginalizing clock-drift and frequency-bias nuisance states. Based on a unified satellite–ground geometry, weighted service coverage, weighted best-link achievable rate, and the proposed positioning metric are jointly optimized using a constrained mixed-integer multi-objective artificial hummingbird algorithm (CMI-MOAHA). The FIM-based metric is consistent with the positioning root mean square error (RMSE) from a separately implemented nonlinear Doppler solver under matched observation and noise assumptions. With the total number of satellites fixed at 2000, the Pareto archive reveals clear trade-offs among coverage, best-link achievable rate, and positioning. When the positioning objective is included, the best obtained positioning metric decreases across all tested constellation sizes, with a maximum reduction of 77.1%. These results show that constellation-level joint optimization is warranted when LEO communication satellites also serve as SoP for Doppler positioning. Full article

High-precision frequency standards underpinning signal synchronization and data consistency are essential for satellites. Navigation satellites use atomic clocks as time and frequency standards; however, limitations in size, weight, and cost constrain their performance. Geostationary Earth orbit (GEO) communication satellites typically rely on onboard oscillators as references, whose performance is generally poor. Moreover, satellite–ground links can be used for frequency synchronization between GEO satellites and ground stations. However, phase drift in onboard oscillators restricts improvements in synchronization precision. This paper introduces a frequency synchronization method based on a beacon transponder that enables ground stations to calculate and eliminate satellite oscillator phase drift. This design achieves high-precision frequency synchronization through real-time carrier-phase compensation and replicates the ground station’s frequency standard onboard. Ground-based experiments validated the method using a beacon transponder prototype in motion. The standard deviation of the phase synchronization error between the replicated clock and ground-station frequency standard was 2.97 ps over 24 h. The stability was better than 2.61 × 10⁻¹² and 9.98 × 10⁻¹⁶ for averaging times of 1 s and 10,000 s, respectively. These results demonstrate this method’s potential for high-precision frequency synchronization between satellites and ground stations, crucial for establishing an integrated space–air–ground frequency synchronization network. Full article

Background/Objectives: Adenosine monophosphate deaminase deficiency has been implicated in impaired exercise capacity. We examined whether the AMPD1 C34T (rs17602729) genotype was associated with athlete status and performance in distance runners (DRs) and rugby union (RU) athletes. Methods: Participants included 621 elite male RU athletes, 666 elite/sub-elite male and female DRs, and 1029 male and female non-athletes (NA), all of European ancestry. Genotyping was performed using real-time PCR with TaqMan reagents. Genotype and allele frequencies were compared using χ² tests, while performance data were analysed using Kruskal–Wallis H, Mann–Whitney U, one-way ANOVA, and t-tests, with Benjamini–Hochberg correction applied for multiple comparisons. Results: Genotype and allele frequencies did not differ between athletes and NA or between athlete groups. In all DRs, run times did not differ between genotypes, although participants with the CT genotype in the elite and elite male subgroups were up to 5% faster than CC and TT homozygotes. In RU, participants with the CC genotype played 13% longer per appearance than those with the CT genotype, while forwards and front five participants with the CC genotype played 13% and 26% longer per appearance than T-allele carriers, respectively. Front five T-allele carriers made 75% more clean breaks than the front five with the CC genotype despite playing for a shorter time, although this finding should be interpreted cautiously. Conclusions: In summary, while the AMPD1 C34T genotype was not associated with athlete status, the CC genotype was associated with greater RU playing time per appearance in forwards, and the CT genotype was associated with superior performance in elite DRs. Full article

The full operation of BDS-3 enables users to obtain high-performance positioning services, benefiting from the surge in the number of Global Navigation Satellite System (GNSS) observations with multi-constellation multi-frequency signals. This overabundance is beneficial to improve in-flight navigation accuracy for small unmanned aerial vehicles (UAVs). However, it brings about two-fold challenges for conventional airborne GNSS/SINS tightly coupled (TC) systems. On one hand, limited airborne computing resources suffer from the “curse of dimensionality” caused by extremely high-dimensional GNSS observations (i.e., GNSS pseudo-ranges, pseudo-range rates, and time-differenced carrier phases from multi-system and multi-frequency, such as GPS L1/L2 and BDS B1/B2/B3, totaling up to over 100 observables per epoch), leading to increased calculation burden and potential latency. On the other hand, possible outliers can degrade the obtained navigation accuracy. To enhance overall performance, this paper proposes a computationally efficient Kalman filtering framework for tight integration between airborne GNSS and SINS via a high-dimensional robust information filter. The strategy of kinematic and static information filtering is utilized to handle the matrix inversion complexity caused by high-rate and high-dimensional Kalman measurement updates, and the technique of robust adaptive factor is used to resist the adverse effects of GNSS outliers and modeling errors. Both land vehicular and UAV flight tests indicate that the proposed algorithm outperforms its traditional TC counterparts, demonstrating an over 90% improvement in overall computational efficiency without any loss in accuracy, compared with conventional batch or sequential tightly coupled Kalman filtering. Full article

With the increasing diversity of multimedia data types, single-modal steganography is insufficient to meet the demand for the simultaneous covert communication of multiple types of data, and single optical transformation encryption schemes are insufficiently secure against cryptanalytic attacks. To address these challenges, this paper designs and implements a multimodal secret information steganography system based on the optical Gyrator transform. We propose a multimodal steganographic system for the covert transmission of three types of heterogeneous secret data—text, color images, and audio—using a three-level cascaded optical encryption architecture. The system first uniformly encapsulates the multimodal data into a unified bitstream via a Type–Length–Value (TLV) format; it then uses the Ushiki chaotic map to generate a pure phase mask for random phase modulation of the carrier image, followed by spatial-frequency scrambling via a fractional Fourier transform (FrFT, order γ = 1.6). The secret bitstream is embedded into all eight bit planes of the amplitude components in the FrFT domain using binary square representation, achieving an embedding capacity of 2.23 × 10⁶ bits—approximately 8.5 times that of traditional LSB methods; finally, a speckle-noise-like ciphertext is output via a Gyrator transform (angle α = 0.5). Experiments demonstrate that under non-attack conditions, the system achieves lossless recovery with a zero bit-error rate. Under known-plaintext and chosen-plaintext attacks on the Gyrator layer, the PSNR of the recovered images was only 4.89 dB and 4.80 dB, respectively, and the secret information could not be effectively extracted, as the chaotic-FrFT pre-encryption statistically isolates the intermediate image from natural image statistics. This system provides a functionally complete and practically secure solution for multimodal covert communication. Full article

To reduce the number of sensors in interior permanent magnet synchronous motor (IPMSM) drive systems, position-sensorless vector control can be combined with single-shunt current reconstruction using a single DC-link shunt resistor. However, applying high-frequency (HF) voltage injection to a single-shunt drive system (SDS) at zero and low speeds causes current reconstruction errors and voltage distortion, thereby degrading the rotor position estimation performance. This paper analyzes these errors and proposes carrier-based voltage vector modification methods for both pulsating voltage injection (PVI) and rotating voltage injection (RVI). Unlike conventional methods requiring multiple pulse-width modulation (PWM) periods and analog-to-digital converter samplings within one control period, the proposed methods retain a conventional carrier-based PWM structure with one control period per PWM period. The voltage vectors in the measurement and compensation intervals are separated and positioned to reflect the current variation induced by the injected HF voltage while satisfying the current reconstruction conditions. Consequently, current reconstruction errors and voltage distortion are reduced without motor parameter-based prediction. The proposed methods are validated through simulations and experiments. Full article

Background: Preventive strategies, including adherence to specific dietary patterns, have received increasing attention as approaches to reduce cognitive decline and dementia risk. However, findings remain inconsistent, partly due to differences in dietary assessment methods, cognitive outcomes, and THE consideration of genetic susceptibility factors such as apolipoprotein E (APOE) genotype. Methods: This study examined associations between dietary patterns and longitudinal cognitive change in 185 older adults without dementia from the Western Australia Memory Study. Participants completed a food frequency questionnaire at baseline and underwent comprehensive neuropsychological assessments at baseline and up to five follow-up visits at 18-month intervals. Composite scores were generated for six cognitive domains and the Preclinical Alzheimer’s Cognitive Composite (PACC). Results: Western and Prudent dietary pattern scores were analysed using linear mixed-effects models stratified by APOE ε4 carrier status. Among APOE ε4 carriers, greater adherence to a Western dietary pattern was associated with a faster decline in attention (p = 0.016), whereas no significant associations were observed for the Prudent dietary pattern or among APOE ε4 non-carriers. This association was attenuated after excluding participants with possible baseline cognitive impairment (MoCA < 23). Conclusion: These findings suggest that adherence to a Western dietary pattern may accelerate cognitive decline in individuals genetically at risk for Alzheimer’s disease, highlighting the importance of considering gene–diet interactions when developing dietary strategies for dementia prevention. Full article

Background/Objectives: Few prospective studies have investigated the association between carbonated soft drink (CSD) consumption and psychological distress (PD) among adults. The current study aimed to examine this association according to the BDNF Val66Met polymorphism and to conduct comparable analyses for coffee and green tea consumption. Methods: Cross-sectional data (n = 6244) and 6-year prospective data (n = 1984) comprising participants aged 43–74 years were analyzed. PD was defined as a Psychosocial Wellbeing Index (PWI) score ≥ 27. Beverage consumption was assessed using a food frequency questionnaire. Modified Poisson regression was employed to estimate multivariable prevalence ratios or risk ratios (RRs) and 95% confidence intervals (CIs) for PD. Results: In cross-sectional data, green tea consumption was inversely associated with PD prevalence in the overall study population (p for trend < 0.05), and its dose–response relationship was observed exclusively among BDNF Met allele (CT and TT) carriers. In 6-year prospective data, CSD consumption was positively associated with PD risk among BDNF Met allele carriers only (p for trend < 0.01); multivariable RR (95% CI) for PD among BDNF Met allele carriers was 1.94 (1.21, 3.10)—(95% CI: 1.09, 3.44) after further applying the Bonferroni correction—for those who consumed ≥ 1 cup/week compared with non-consumers. No prospective association was observed for coffee and green tea consumption in the overall study population and genotype-specific analyses. Conclusions: CSD consumption was associated with increased PD risk among individuals carrying the BDNF Met allele, which is known to be associated with various stress-related psychological conditions. These findings suggest that CSD consumption may be particularly harmful to individuals with specific genetic factors. Full article

Objectives: Coronary artery disease (CAD) remains a leading cause of morbidity and mortality worldwide, yet population-specific evidence regarding the contribution of MIA3 genetic variation in Middle Eastern populations remains limited. This study investigated the association of the MIA3 rs17465637 polymorphism with CAD susceptibility and its relationship with lipid-related phenotypes in a Saudi population. Methods: A case–control study was conducted between June 2020 and August 2022, including 200 patients with angiographically confirmed CAD and 200 age- and sex-matched healthy Saudi controls. Genotyping of rs17465637 was performed using a TaqMan real-time polymerase chain reaction assay. Genotype distributions were evaluated using chi-square analysis under multiple inheritance models. Multivariable logistic regression was subsequently performed to estimate adjusted odds ratios after controlling age, BMI, smoking, physical inactivity, systolic BP, diastolic BP, blood glucose, triglycerides, total cholesterol, LDL-C, and HDL-C. Associations between rs17465637 genotypes and serum lipid parameters were also examined. Results: Genotype frequencies of rs17465637 differed modestly between cases and controls; however, unadjusted comparisons under codominant, dominant, recessive, and allelic inheritance models did not reach statistical significance, and none remained significant after Bonferroni correction. In contrast, multivariable logistic regression demonstrated an independent association between the rs17465637 C allele and CAD after adjustment for conventional cardiovascular risk factors. In genotype–phenotype analyses, carriers of the C allele exhibited higher association with low-density lipoprotein cholesterol concentrations and less favorable lipid profiles than AA homozygotes, supporting a relationship between the variant and lipid metabolism. These findings are consistent with a potential contribution of rs17465637 to CAD susceptibility through lipid-related pathways. Conclusions: Although unadjusted genotype comparisons were not statistically significant after correction for multiple testing, multivariable analysis provides evidence supporting an independent association between the MIA3 rs17465637 variant and CAD susceptibility in this Saudi cohort. The observed associations with adverse lipid profiles further provide evidence linking this specific locus to the molecular mechanisms underlying cardiovascular disease. Replication in larger, multi-center studies incorporating genome-wide ancestry-informative markers and functional investigations is warranted to further minimize the possibility of residual population stratification, confirming these findings and clarifying the biological mechanisms underlying this association. Full article

GNSS/INS integrated navigation combines the long-term stability of satellite positioning with the high-frequency continuity of inertial navigation, and has been widely adopted in vehicle navigation, unmanned systems, and intelligent transportation systems. However, in complex urban environments, GNSS measurement noise exhibits significant time-varying characteristics, while high-dynamic carrier motions may cause mismatches between the dynamic model and the actual motion state. These two factors jointly degrade the performance of conventional Sage–Husa (cSage–Husa) filters, resulting in distorted measurement noise estimation and over-adaptation. To address this issue, this paper proposes a dual-adaptive Sage–Husa filtering algorithm considering model matching. The proposed algorithm integrates a forgetting-factor-based global recursive estimation mechanism with an adaptive sliding window strategy. Furthermore, a model matching test and a measurement noise covariance upper-bound constraint are introduced to distinguish model mismatch errors from normal measurement noise variations, thereby improving filtering stability and noise estimation reliability. Experimental results demonstrate that, under initial high-dynamic motions and instantaneous GNSS interference conditions, the proposed algorithm reduces the up-channel RMS error by 8.5% compared with cSage–Husa. Under sustained GNSS degradation conditions, the north RMS error is reduced by 8.7% and 2.5% compared with EKF and cSage–Husa, respectively, while the up-channel RMS error is reduced by 15% compared with cSage–Husa and maintains comparable accuracy to EKF. The proposed algorithm effectively mitigates over-adaptation and convergence degradation caused by model mismatch, achieving a favorable balance between time-varying noise tracking capability and filtering stability for urban canyon and high-dynamic vehicle positioning. Full article

Fine-grained urban cultural perception is critical for GIScience, yet traditional social media studies struggle with complex cultural semantics and heterogeneous factor integration. Addressing Beijing’s “Capital Culture,” this study couples LLM agents with higher-order tensor decomposition. Using 2019 full-sample geotagged Sina Weibo data, we developed a four-agent collaborative architecture with Chain-of-Thought prompting and human-in-the-loop mechanisms via a locally deployed Qwen3-32B model. A four-way tensor (“Cultural Type–Evaluation Aspect–Sentiment Polarity–Spatial Carrier”) was constructed and integrated with kernel density estimation to characterize spatial differentiation. We address three questions: whether LLMs can reliably classify fine-grained cultural perceptions, how cultural types associate with evaluation dimensions, sentiments, and spatial carriers, and whether tensor decomposition reveals latent patterns beyond marginal frequencies. The agentic workflow achieves over 90% accuracy in cultural and sentiment classification, and the tensor decomposition attains a 94.87% goodness-of-fit, successfully identifying latent patterns. Spatially, Beijing’s capital culture exhibits an unbalanced hierarchical structure—“high coupling in the core area with differentiated expansion at the periphery.” This study validates the transition from “data-driven” to “AI + data dual-driven” spatial analysis, providing a quantifiable pathway for LLM-supported urban cultural governance. Full article