Search Results (26)

Maintaining structural stability and reliable mooring performance remains a key challenge for offshore floating photovoltaic (FPV) systems. This study investigates the coupled hydrodynamic and mooring behavior of a novel large-scale hexagonal rigid FPV platform through 1:25-scale physical model tests. A near-zero-pre-tension slack mooring arrangement was adopted to isolate the effects of mooring type, including anchor chain (M1), steel cable (M2), and elastic cable (M3). The results show that the influence of mooring configuration is strongly degree-of-freedom dependent. Surge motion is highly sensitive to mooring type, whereas heave and pitch remain largely consistent among the three cases. In regular waves, the maximum surge-acceleration RAO of M2 is 1.82 and 2.27 times those of M1 and M3, respectively. Peak mooring tension shows a strong correlation with maximum surge acceleration in both regular and irregular waves, indicating that surge motion can serve as a useful indicator of extreme mooring loads under similar slack-mooring conditions. Among the three configurations, M1 exhibits the strongest short-term peak-load buffering. Under extreme irregular waves, its peak mooring tension is 82.4% and 24.7% lower than those of M2 and M3, respectively. These results provide experimental guidance for the mooring design of large-scale rigid FPV systems. Full article

Adolescent gambling is a growing public health concern as opportunities expand across both physical and digital environments. This study examined gender differences in on-site and online gambling among Finnish adolescents and assessed associations with school engagement, family context, peer activities, and co-occurring risk behaviors. Data were obtained from the European School Survey Project on Alcohol and Other Drugs (ESPAD), collected from Finnish adolescents aged 15–16 in 2024 (boys: n = 1706; girls: n = 1588). Associations with past-12-month gambling were analyzed using Rao–Scott’s chi-square tests, F tests, and multinomial logistic regression, examining gender interactions. Gambling was more common among boys than girls: 7% of boys had gambled on-site only, 3% online only, and 11% both during the past 12 months. Among girls, the corresponding proportions were 0–2%. Skipping school, spending leisure time with friends, risky sexual behavior, and problematic substance use were associated with increased odds of both gambling types, whereas parental control was associated with decreased odds. Problematic social media increased the odds of on-site gambling, while problematic gaming decreased the odds. Several associations with online gambling differed by gender. These findings support multi-level prevention targeting family, school, peer, and behavioral risk factors. Full article

Background/Objectives: The transradial approach is widely used for vascular access in many disciplines. Radial artery occlusion (RAO) is a frequent sequel, and hand/arm pain affects 7.8% of patients. We aimed to elucidate whether RAO or ulnar artery occlusion (UAO) causes impaired neural blood flow and, thus, if symptoms may be attributable to claudication or nerve damage. Methods: Forty healthy volunteers (73% female), with a mean age of 38 years and without clinical or sonographic signs of carpal tunnel syndrome, were included. All underwent a standardized ultrasound examination (Aplio i800 and i22LH8 linear transducer, Canon Medical Systems) of the forearm, investigating the median nerve and its intraneural blood flow as well as the vascular status of the limb. The radial and ulnar arteries were then sequentially compressed, while changes to intraneural blood flow were noted. Thereafter, the (reverse) Barbeau test and the (inverse) modified Allen Test (MAT) were performed. Results: Simulated RAO and UAO halted intraneural blood flow in 65% and 62.5% of individuals, respectively. A total of 32.5% of participants reported discomfort in the hand/arm. Absent flow during occlusion was found at a significantly higher rate in symptomatic individuals. MAT and inverse MAT were abnormal (>10 s) in 17.5% and 7.5% of patients. Barbeau and reverse Barbeau produced type D results in 15% and 20%, respectively. Conclusions: Both simulated RAO and UAO caused the cessation of intraneural blood flow of the median nerve in two-thirds of participants, and a large proportion reported symptoms. MAT and Barbeau tests did not seem to be useful in predicting impaired neural blood flow. Full article

The pressure-gradient Micro-Electro-Mechanical Systems (MEMS) vector hydrophone is a novel type of sensor capable of simultaneously acquiring both scalar and vectorial information within an acoustic field. Conventional azimuth estimation methods struggle to achieve high-resolution localization using a single pressure-gradient MEMS vector hydrophone. In practical marine environments, the multiple signal classification (MUSIC) algorithm is hampered by significant resolution performance loss. Similarly, the complex acoustic intensity (CAI) method is constrained by a high-resolution threshold for multiple targets, often resulting in inaccurate azimuth estimates. Therefore, a cross-spectral model between the acoustic pressure and the particle velocity for the pressure-gradient MEMS vector hydrophone was established. Integrated with an improved particle swarm optimization (IPSO) algorithm, a high-resolution azimuth estimation method utilizing this hydrophone is proposed. Furthermore, the corresponding Cramér-Rao Bound is derived. Simulation results demonstrate that the proposed algorithm accurately resolves two targets separated by only 5° at a low signal-to-noise ratio (SNR) of 5 dB, boasting a root mean square error of approximately 0.35° and a 100% success rate. Compared with the CAI method and the MUSIC algorithm, the proposed method achieves a lower resolution threshold and higher estimation accuracy, alongside low computational complexity that enables efficient real-time processing. Field tests in an actual seawater environment validate the algorithm’s high-resolution performance as predicted by simulations, thus confirming its practical efficacy. The proposed algorithm addresses key limitations in underwater detection by enhancing system robustness and offering high-resolution azimuth estimation. This capability holds promise for extending to multi-target scenarios in complex marine settings. Full article

Marine risers, critical structures connecting underwater production systems and surface floating platforms, stand freely in water and endure extremely complex marine environmental loads. To meet the multi-parameter observation demand for their overall state, a fiber-optic sensing-based marine riser buoy observation system was developed. Unlike traditional point-type and offline monitoring systems, it integrates marine buoys with sensing submarine cables to achieve long-term real-time online monitoring of risers’ overall state via fiber-optic sensing technology. Comprising two main modules (buoy monitoring module and fiber-optic sensing module), the buoy’s stability was verified through theoretical derivation, simulation, and stability curve plotting. Frequency domain analysis of buoy loads and motion responses, along with calculation of motion response amplitude operators (RAOs) at various incident angles, showed the system avoids wave periods in the South China Sea (no resonance), ensuring structural safety for offshore operations. A 7-day marine test of the prototype was conducted in Yazhou Bay, Hainan Province, to monitor real-time temperature and strain data of the riser in the test sea area. The sensing submarine cable accurately responded to temperature changes at different depths with high stability and precision; using the Frenet-based 3D curve reconstruction algorithm, pipeline shape was inverted from the monitored strain data, enabling real-time pipeline monitoring. During the test, the buoy and fiber-optic sensing module operated stably. This marine test confirms the buoy observation system’s reasonable design parameters and feasible scheme, applicable to temperature and deformation monitoring of marine risers. Full article

The hydrodynamic response of closed and semi-closed (open-bottom) rigid cylindrical aquaculture platforms was examined through combined model tests and numerical simulations. Free decay tests in calm water quantified natural periods and damping ratios for heave and pitch motions. Subsequent regular wave testing characterized response amplitude operators (RAOs) and wave elevations at interior and exterior wave gauges. Finally, the motion and wave elevation characteristics of the two types of aquaculture platforms under irregular waves were analyzed under extreme sea conditions. Results demonstrated that bottom openings significantly altered hydrodynamic responses of aquaculture platforms, with a 59% enhancement in heave damping ratio and a 47% reduction in heave natural period. Semi-closed cages exhibited asymmetric internal sloshing profiles along the mid-transverse axis, with lateral sloshing amplitudes increasing by 200–300% at lateral wave gauges. Under irregular wave conditions, compared to closed aquaculture platform, semi-closed aquaculture platform increased the heave, pitch motion, and internal sloshing response but reduced run-up on the outer wave-facing side. Full article

In online communities, polarization refers to the phenomenon in which individuals become more divided and extreme in their opinions due to their exposure to specific content. In this paper, we present a network-based framework for evaluating polarization levels in Online Social Networks (OSNs). Starting from a dataset of comments, our framework creates a network of user interactions and leverages the Louvain algorithm, the Rao’s Quadratic Entropy, and ego networks to assess the polarization level of communities and the most influential users. To test our framework, we leveraged a dataset of tweets about climate change. After performing Extraction, Transformation and Loading activities on the dataset, we evaluated its labels, identified communities, and analyzed their polarization level and that of the most influential users. We also analyzed the ego networks of believers and deniers and the aggressiveness of the corresponding tweets. Our analysis revealed the existence of polarized communities and homophily among the most influential users. It also showed that the type of communication used to disseminate information influences the polarization level of both communities and individual users. These results demonstrate our framework’s ability to support the polarization analysis in OSNs. Full article

Background/Objectives: Veterans differ in sociodemographic composition and experience higher frequencies of disability than non-Veterans of the same age. Yet the epidemiology of the long-term care needs of Veterans, specifically activities of daily living (ADLs) and instrumental activities of daily living (IADLs), remains an important gap in the literature. The objectives of this study were to (1) characterize Veterans across levels of hierarchy of ADL and IADL support needs; (2) compare Veterans across the degree of need for help, from those who can still “self-manage” to those with an “unmet need”; and (3) identify the types and prevalence of ADL and IADL need combination patterns. Methods: This study used cross-sectional data from the 2021 administration of the HERO CARE survey. We included Veterans ages 65+ in our analyses (N = 7424). We calculated the overall weighted descriptive statistics across a hierarchy of ADL and IADL problems and the degree of need for help. One-way ANOVA for continuous variables and Rao–Scott chi-square tests for categorical variables were conducted to examine associations between groups, followed by post hoc pairwise comparisons, as appropriate. Results: Veteran respondents mean age was 82.3 (SD: 8.2 years), and most were male, non-Hispanic White, and married. In weighted analyses, more Veterans with both ADL and IADL problems compared to only ADL problems reported food insecurity, missed appointments, low health literacy, and depression. Among Veterans with ADL or IADL problems, 32.3% reported an unmet need for help. Almost a quarter of Veterans with ADL problems reported difficulties performing all eight ADLs (23.9%), and over a quarter of Veterans with IADL problems reported difficulties performing all seven IADLs (31.3%). Conclusions: Our findings show that Veterans are demographically and clinically different based on their hierarchy of impairment and degree of need for help. Identifying the patterns and prevalence of ADL and IADL needs among Veterans provides valuable information to align the Veterans Affairs (VA) programs and services with Veterans’ needs. Full article

This study investigates the seakeeping performance of a wind power generation ship (WPG ship). This type of vessel uses rigid sails for propulsion and submerged turbines in the form of either two or four booms to generate energy. The research includes both tank tests and simulations using Ansys AQWA, validated with the new strip method (NSM). The vessel used in this study is the container ship KCS. Overall, the power generator increases the ship’s stability and reduces roll but has almost no impact on pitch. The findings show that the 4-boom configuration offers better stability and seakeeping than the 2-boom configuration. The ship’s speed has a significant impact on the ship’s RAO, especially roll and pitch, both for the bare hull and the hull with power generation equipment. When the ship’s speed increases slightly, the roll RAO tends to decrease, but as the speed becomes higher, the RAO tends to increase. Wind conditions notably increase the roll RAO peak, reducing stability, while pitch changes are minimal. The KCS model maintains operational capability in winds up to Beaufort scale 11. Full article

Purpose: The isocitrate dehydrogenase (IDH) mutation has become one of the most important prognostic biomarkers in glioma management, indicating better treatment response and prognosis. IDH mutations confer neomorphic activity leading to the conversion of alpha-ketoglutarate (α-KG) to 2-hydroxyglutarate (2HG). The purpose of this study was to investigate the clinical potential of proton MR spectroscopy (¹H-MRS) in identifying IDH-mutant gliomas by detecting characteristic resonances of 2HG and its complex interplay with other clinically relevant metabolites. Materials and Methods: Thirty-two patients with suspected infiltrative glioma underwent a single-voxel (SVS, n = 17) and/or single-slice-multivoxel (¹H-MRSI, n = 15) proton MR spectroscopy (¹H-MRS) sequence with an optimized echo-time (97 ms) on 3T-MRI. Spectroscopy data were analyzed using the linear combination (LC) model. Cramér–Rao lower bound (CRLB) values of <40% were considered acceptable for detecting 2HG and <20% for other metabolites. Immunohistochemical analyses for determining IDH mutational status were subsequently performed from resected tumor specimens and findings were compared with the results from spectral data. Mann–Whitney and chi-squared tests were performed to ascertain differences in metabolite levels between IDH-mutant and IDH-wild-type gliomas. Receiver operating characteristic (ROC) curve analyses were also performed. Results: Data from eight cases were excluded due to poor spectral quality or non-tumor-related etiology, and final data analyses were performed from 24 cases. Of these cases, 9/12 (75%) were correctly identified as IDH-mutant or IDH-wildtype gliomas through SVS and 10/12 (83%) through ¹H-MRSI with an overall concordance rate of 79% (19/24). The sensitivity, specificity, positive predictive value, and negative predictive value were 80%, 77%, 86%, and 70%, respectively. The metabolite 2HG was found to be significant in predicting IDH-mutant gliomas through the chi-squared test (p < 0.01). The IDH-mutant gliomas also had a significantly higher NAA/Cr ratio (1.20 ± 0.09 vs. 0.75 ± 0.12 p = 0.016) and lower Glx/Cr ratio (0.86 ± 0.078 vs. 1.88 ± 0.66; p = 0.029) than those with IDH wild-type gliomas. The areas under the ROC curves for NAA/Cr and Glx/Cr were 0.808 and 0.786, respectively. Conclusions: Noninvasive optimized ¹H-MRS may be useful in predicting IDH mutational status and 2HG may serve as a valuable diagnostic and prognostic biomarker in patients with gliomas Full article

(1) Introduction: The Democratic Republic of the Congo (DRC) has one of the largest cohorts of un- and under-vaccinated children worldwide. This study aimed to identify and compare the main reasons for there being zero-dose (ZD) or under-vaccinated children in the DRC. (2) Methods: This is a secondary analysis derived from a province-level vaccination coverage survey conducted between November 2021 and February 2022; this survey included questions about the reasons for not receiving one or more vaccines. A zero-dose child (ZD) was a person aged 12–23 months not having received any pentavalent vaccine (diphtheria–tetanus–pertussis–Hemophilus influenzae type b (Hib)–Hepatitis B) as per card or caregiver recall and an under-vaccinated child was one who had not received the third dose of the pentavalent vaccine. The proportions of the reasons for non-vaccination were first presented using the WHO-endorsed behavioral and social drivers for vaccination (BeSD) conceptual framework and then compared across the groups of ZD and under-vaccinated children using the Rao–Scott chi-square test; analyses were conducted at province and national level, and accounting for the sample approach. (3) Results: Of the 51,054 children aged 12–23 m in the survey sample, 19,676 ZD and under-vaccinated children were included in the study. For the ZD children, reasons related to people’s thinking and feelings were cited as 64.03% and those related to social reasons as 31.13%; both proportions were higher than for under-vaccinated children (44.7% and 26.2%, respectively, p < 0.001). Regarding intentions to vaccinate their children, 82.15% of the parents/guardians of the ZD children said they wanted their children to receive “none” of the recommended vaccines, which was significantly higher than for the under-vaccinated children. In contrast, “practical issues” were cited for 35.60% of the ZD children, compared to 55.60% for the under-vaccinated children (p < 0.001). The distribution of reasons varied between provinces, e.g., 12 of the 26 provinces had a proportion of reasons for the ZD children relating to practical issues that was higher than the national level. (4) Conclusions: reasons provided for non-vaccination among the ZD children in the DRC were largely related to lack of parental/guardian motivation to have their children vaccinated, while reasons among under-vaccinated children were mostly related to practical issues. These results can help inform decision-makers to direct vaccination interventions. Full article

Skewed probability distributions are important when modeling skewed data sets because they provide a way to describe the shape of the distribution and estimate the likelihood of extreme events. Asymmetric probability distributions have the potential to handle and assess problems in actuarial risk assessment and analysis. To that end, we present a new right-skewed one-parameter distribution. In this work and for this purpose, a right-skewed probability distribution was derived and analyzed. The new distribution outperformed the exponential distribution, the Pareto distribution, the Chen distribution, and others in the field of actuarial risk analysis. Some useful key risk indicators are considered and analyzed to analyze the risks and for comparison with the competitive model. Several actuarial risk functions and indicators are evaluated and analyzed using the U.K. insurance claims data set. The process of risk assessment and analysis was carried out using a comprehensive simulation. For the purposes of distributional validity, a modified chi-squared type test is presented and employed in the testing process. The new, modified chi-squared type test that is used is simply an extension of the Rao–Robson–Nikulin test. In this work, the distributional validity is presented and analyzed under right-skewed censored and uncensored data sets. Full article

In this paper, we introduce the restricted minimum density power divergence Gaussian estimator (MDPDGE) and study its main asymptotic properties. In addition, we examine it robustness through its influence function analysis. Restricted estimators are required in many practical situations, such as testing composite null hypotheses, and we provide in this case constrained estimators to inherent restrictions of the underlying distribution. Furthermore, we derive robust Rao-type test statistics based on the MDPDGE for testing a simple null hypothesis, and we deduce explicit expressions for some main important distributions. Finally, we empirically evaluate the efficiency and robustness of the method through a simulation study. Full article

Three models with different footing types were used to clarify the effect of heave plates on the hydrodynamic behavior of the elastic response of a flexible multicolumn floating offshore wind turbine (FOWT). The models were tested under regular waves, whose added mass, damping, and motion response results were compared with numerical simulations by NK-UTWind and WAMIT codes. As a whole, the attachment of heave plates was responsible for increasing the added mass and damping levels, consequently modifying the RAO of the models. Regarding the response in a sea condition, a decrease of 33% and 66% of the significant motion height (heave and pitch) was observed. Thus, the heave plate can be a good feature for the future design of FOWT. Full article

This study analyzed the effect of the household type on the prevalence of metabolic syndrome in Koreans utilizing data from the sixth, seventh, and eighth Korea National Health and Nutrition Examination Surveys conducted by the Korea Disease Control and Prevention Agency from 2015 to 2019. The demographic characteristics, metabolic syndrome characteristics according to household type, and risk factors of 25,092 subjects were identified using the Rao–Scott χ²–test and weighted multiple logistic regression results. Furthermore, to understand the effect of the household type on prevalence of metabolic syndrome, the selection bias between the groups was eliminated using the propensity score matching method. The average treatment effect for those treated for metabolic syndrome prior to propensity score matching was higher for single-person households, with 0.353 and 0.268 for single- and multi-person households, respectively. The difference was statistically significant (p < 0.0001). However, after propensity score matching, it was observed to be higher for multi-person households, with 0.290 and 0.316 for single- and multi-person households, respectively. However, the difference was not statistically significant (p < 0.1822). Difference was observed regarding the prevalence of metabolic syndrome by individual characteristics, some of which were considered in previous studies. However, the household type alone did not explain the prevalence of metabolic syndrome. Full article