Jeans analysis with κ-deformed Kaniadakis distribution in f (R) gravity

The influence of the κ-deformed Kaniadakis distribution on Jeans instability in the background of f(R) gravity is investigated, the dispersion relation considering the κ-deformed Kaniadakis distribution is derived by exploiting the kinetic theory. The cases of high and low frequency perturbations are analyzed, respectively, it is found that the range of the unstable modes and the growth rates decrease with the increased distribution index κ in both of high and low frequency regime. Finally, based on the derivation of effective temperature, the relation between Jeans mass and temperature is studied, it is found that lower Jeans mass means that the system is more likely to collapse due to gravitational instability, the system is unstable for lower distribution index κ.

Load Balancing Routing Algorithm of Low-Orbit Communication Satellite Network Traffic Based on Machine Learning

Satellite communication has become an important research trend in the field of communication technology. Low-orbit satellites have always been the focus of extensive attention by scholars due to their wide coverage, strong flexibility, and freedom from geographical constraints. This article introduces some technologies about low-orbit satellites and introduces a routing algorithm DDPG based on machine learning for simulation experiments. The performance of this algorithm is compared with the performance of three commonly used low-orbit satellite routing algorithms, and a conclusion is drawn. The routing algorithm based on machine learning has the smallest average delay, and the average value is 126 ms under different weights. Its packet loss rate is the smallest, with an average of 2.9%. Its throughput is the largest, with an average of 201.7 Mbps; its load distribution index is the smallest, with an average of 0.54. In summary, the performance of routing algorithms based on machine learning is better than general algorithms.

Incorporating Medical Supply and Demand into the Index of Physician Maldistribution Improves the Sensitivity to Healthcare Outcomes

Background: Since the association between disparity in physician distribution and specific healthcare outcomes is poorly documented, we aimed to clarify the association between physician maldistribution and cerebrovascular disease (CeVD), a high-priority health outcome in Japan. Methods: In this cross-sectional study, we conducted multivariable regression analysis with the Physician Uneven Distribution Index (PUDI), a recently developed and adopted policy index in Japan that uniquely incorporates the gap between medical supply and demand, as the independent variable and CeVD death rate as the dependent variable. Population density, mean annual income, and prevalence of hypertension were used as covariates. Results: The coefficient of the PUDI for the CeVD death rate was −0.34 (95%CI: −0.49–−0.19) before adjusting for covariates and was −0.19 (95%CI: −0.30–−0.07) after adjusting. The adjusted R squared of the analysis for the PUDI was 0.71 in the final model. However, the same multivariable regression model showed that the number of physicians per 100,000 people (NPPP) was not associated with the CeVD death rates before or after adjusting for the covariates. Conclusion: Incorporating the gap between the medical supply and demand in physician maldistribution indices could improve the responsiveness of the index for assessing the disparity in healthcare outcomes.

Development of HFU-based permeability prediction models using core data for characterisation of a heterogeneous Oligocene sand in the Nam Con Son basin

Core data by both routine and special core analysis are required to understand and predict reservoir petrophysical characteristics. In this research, a total number of 50 core plugs taken from an Oligocene sand (T30) in the Nam Con Son basin, offshore southern Vietnam, were tested in the core laboratory of the Vietnam Petroleum Institute (VPI). The results of routine core analysis (RCA) including porosity and permeability measurements were employed to divide the study reservoir into hydraulic flow units (HFUs) using the global hydraulic elements (GHEs) approach. Based on five classified HFUs, 16 samples were selected for special core analysis, i.e., mercury injection capillary pressure (MICP) and grain size analyses for establishing non-linear porosity-permeability model of each HFU based on Kozeny-Carman equation, which provides an improved prediction of permeability (R2 = 0.846) comparing to that by the empirical poro-perm relationship (R2 = 0.633). In addition, another permeability model, namely the Winland R35 method, was applied and gave very satisfactory results (R2 = 0.919). Finally, by integrating the results from MICP and grain size analyses, a good trendline of pore size distribution index (λ) and grain sorting was successfully obtained to help characterise the study reservoir. High λ came with poor sorting, and vice versa, the low λ corresponded to good sorting of grain size.

Community structure of sea cucumber on Harapan Island and East Penjaliran Island, Kepulauan Seribu National Park, Indonesia

Sea cucumbers are marine animals of the Holothuroidea Class that have ecological, health, and socioeconomic benefits. This study aims to determine the structure of the sea cucumber community on Harapan Island and East Penjaliran Island, Kepulauan Seribu National Park, Kepulauan Seribu Regency. Data collection was conducted in January 2020, where each island was divided into two stations, and each station was divided into three substations for data retrieval. The method is a quadratic transect method using a plot measuring 1x1 m. In each square plot, observations were made regarding the type and number of sea cucumbers found and water quality parameters, including salinity, temperature, pH, DO, and total organic matter. Observation parameters include diversity index, uniformity index, frequency, density, important value index, dominance, and sea cucumber distribution index. During the study, species found on Harapan Island include H. atra, H. scabra, H. leucospilota, Bohadschia marmorata, and Stichopus herrmanni. Meanwhile, species found on East Penjaliran Island include H. atra, H. leucospilota, H. coluber, H. pardalis, H. fuscocinerea, H. hilla, Bohadschia marmorata, Stichopus ocellatus, and Stichopus monotuberculatus. The most abundant and predominant species on both islands is Holothuria atra. The average diversity index on Harapan Island falls into the low category, while East Penjaliran Island is classified as medium. The dominance index of both islands is low and has a uniform distribution. Environmental conditions and sea cucumber exploitation affect the structure of sea cucumber communities on both islands.

Influence of Material Parameters on the Contact Pressure Characteristics of a Multi-Disc Clutch

As an essential part of the transmission, the life of the clutch directly affects the stability of the transmission. In this paper, a finite element model and a thermodynamic numerical model of a multi-disc clutch are established to investigate the influence of material parameters on the contact pressure distribution. The pressure distribution index (PDI) is firstly proposed to evaluate the pressure difference among friction pairs. Moreover, the correctness of the numerical model is verified by the clutch static pressure experiment. The results show that increasing the elastic modulus and Poisson’s ratio of the backplate can effectively improve the uniformity of the contact pressure. However, the variations in material parameters of other clutch components can not easily smooth the pressure difference. Therefore, optimized material parameters for the clutch are proposed, where the maximum pressure and temperature differences are reduced by about 27.2% and 10.3%, respectively.

Lordosis Distribution Index in Short-Segment Lumbar Spine Fusion – Can Ideal Lordosis Reduce Revision Surgery and Iatrogenic Deformity?

Objective: The demand for spinal fusion is increasing, with concurrent reports of iatrogenic adult spinal deformity (flatback deformity) possibly due to inappropriate lordosis distribution. This distribution is assessed using the lordosis distribution index (LDI) which describes the upper and lower arc lordosis ratio. Maldistributed LDI has been associated to adjacent segment disease following interbody fusion, although correlation to later-stage deformity is yet to be assessed. We therefore aimed to investigate if hypolordotic lordosis maldistribution was associated to radiographic deformity-surrogates or revision surgery following instrumented lumbar fusion.Methods: All patients undergoing fusion surgery ( ≤ 4 vertebra) for degenerative lumbar diseases were retrospectively included at a single center. Patients were categorized according to their postoperative LDI as: “normal” (LDI 50–80), “hypolordotic” (LDI < 50), or “hyperlordotic” (LDI > 80).Results: We included 149 patients who were followed for 21 ± 14 months. Most attained a normally distributed lordosis (62%). The hypolordotic group had increased postoperative pelvic tilt (PT) (p < 0.001), pelvic incidence minus lumbar lordosis (PI–LL) mismatch (p < 0.001) and decreased global lordosis (p = 0.007) compared to the normal group. Survival analyses revealed a significant difference in revision surgery (p = 0.03), and subsequent multivariable logistic regression showed increased odds of 1-year revision in the hypolordotic group (p = 0.04). There was also a negative, linear correlation between preoperative pelvic incidence (PI) and postoperative LDI (p < 0.001).Conclusion: In patients undergoing instrumented lumbar fusion surgery, hypolordotic lordosis maldistribution (LDI < 50) was associated to increased risk of revision surgery, increased postoperative PT and PI–LL mismatch. Lordosis distribution should be considered prior to spinal fusion, especially in high PI patients.

Therapeutic Effect of Tetrax based Visual Biofeedback Training for Balance Dysfunction in a Child with Ataxic Cerebral Palsy- A Case Report

Background and Purpose: The study investigated the effectiveness of Tetrax biofeedback training on balance of a child with ataxic Cerebral Palsy (ACP). Both Tetrax and conventional Occupational Therapy (COT) were performed. Each session of Tetrax and COT was carried out for 30 minutes, 3 times per week for 4 weeks. Primary outcome measure was Berg balance Scale (BBS) and fall index (FI). Secondary outcome measures were the stability index (ST) and the weight distribution index (WDI). Tetrax training has effectively aided in the recovery of balance when used in addition to the COT treatment, however further studies with larger populations are required for evidence of its effectiveness. Key words: Ataxia, Tetrax, Balance, Biofeedback, Rehabilitation.